lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

53 files changed, 9828 insertions, 0 deletions

diff --git a/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp b/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp
new file mode 100644
index 0000000..0bc9727
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp
@@ -0,0 +1,220 @@
+
+#include <arpa/inet.h>
+#include <bits/ensure.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <mlibc/bitutil.hpp>
+#include <mlibc/debug.hpp>
+
+const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
+const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
+
+uint32_t htonl(uint32_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint32_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint16_t htons(uint16_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint16_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint32_t ntohl(uint32_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint32_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint16_t ntohs(uint16_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint16_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+
+// ----------------------------------------------------------------------------
+// IPv4 address manipulation.
+// ----------------------------------------------------------------------------
+in_addr_t inet_addr(const char *p) {
+	struct in_addr a;
+	if(!inet_aton(p, &a))
+		return -1;
+	return a.s_addr;
+}
+char *inet_ntoa(struct in_addr addr) {
+	// string: xxx.yyy.zzz.aaa
+	// 4 * 3 + 3 + 1 = 12 + 4 = 16
+	thread_local static char buffer[16];
+	uint32_t proper = htonl(addr.s_addr);
+	snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d",
+		(proper >> 24) & 0xff, ((proper >> 16) & 0xff),
+		(proper >> 8) & 0xff, proper & 0xff);
+	return buffer;
+}
+int inet_aton(const char *string, struct in_addr *dest) {
+	int array[4];
+	int i = 0;
+	char *end;
+
+	for (; i < 4; i++) {
+		array[i] = strtoul(string, &end, 0);
+		if (*end && *end != '.')
+			return 0;
+		if (!*end)
+			break;
+		string = end + 1;
+	}
+
+	switch (i) {
+		case 0:
+			dest->s_addr = htonl(array[0]);
+			break;
+		case 1:
+			if (array[0] > 255 || array[1] > 0xffffff)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | array[1]);
+			break;
+		case 2:
+			if (array[0] > 255 || array[1] > 255 ||
+					array[2] > 0xffff)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | (array[1] << 16) |
+				array[2]);
+			break;
+		case 3:
+			if (array[0] > 255 || array[1] > 255 ||
+					array[2] > 255 || array[3] > 255)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | (array[1] << 16) |
+				(array[2] << 8) | array[3]);
+			break;
+	}
+
+	return 1;
+}
+
+// ----------------------------------------------------------------------------
+// Generic IP address manipulation.
+// ----------------------------------------------------------------------------
+const char *inet_ntop(int af, const void *__restrict src, char *__restrict dst,
+		socklen_t size) {
+	switch (af) {
+		case AF_INET: {
+			auto source = reinterpret_cast<const struct in_addr*>(src);
+			if (snprintf(dst, size, "%d.%d.%d.%d",
+						source->s_addr & 0xff,
+						(source->s_addr & 0xffff) >> 8,
+						(source->s_addr & 0xffffff) >> 16,
+						source->s_addr >> 24) < (int)size)
+				return dst;
+			break;
+		}
+		case AF_INET6: {
+			auto source = reinterpret_cast<const struct in6_addr*>(src);
+			size_t cur_zeroes_off = 0;
+			size_t cur_zeroes_len = 0;
+			size_t max_zeroes_off = 0;
+			size_t max_zeroes_len = 0;
+
+			/* we look for the largest block of zeroed quartet(s) */
+			for(size_t i = 0; i < 8; i++) {
+				auto ptr = source->s6_addr + (i * 2);
+				if(!ptr[0] && !ptr[1]) {
+					cur_zeroes_len++;
+					if(max_zeroes_len < cur_zeroes_len) {
+						max_zeroes_len = cur_zeroes_len;
+						max_zeroes_off = cur_zeroes_off;
+					}
+				} else {
+					/* advance the offset to the next quartet to check */
+					cur_zeroes_len = 0;
+					cur_zeroes_off = i + 1;
+				}
+			}
+
+			size_t off = 0;
+			for(size_t i = 0; i < 8; i++) {
+				auto ptr = source->s6_addr + (i * 2);
+
+				/* if we are at the beginning of the largest block of zeroed quartets, place "::" */
+				if(i == max_zeroes_off && max_zeroes_len >= 2) {
+					if(off < size) {
+						dst[off++] = ':';
+					}
+					if(off < size) {
+						dst[off++] = ':';
+					}
+					i += max_zeroes_len - 1;
+
+					continue;
+				}
+
+				/* place a colon if we're not at the beginning of the string and it is not already there */
+				if(off && dst[off - 1] != ':') {
+					if(off < size) {
+						dst[off++] = ':';
+					}
+				}
+
+				off += snprintf(dst + off, size - off, "%x", ptr[0] << 8 | ptr[1]);
+			}
+
+			dst[off] = 0;
+
+			return dst;
+		}
+		default:
+			errno = EAFNOSUPPORT;
+			return NULL;
+	}
+
+	errno = ENOSPC;
+	return NULL;
+}
+int inet_pton(int af, const char *__restrict src, void *__restrict dst) {
+	switch (af) {
+		case AF_INET: {
+			uint8_t array[4] = {};
+			for (int i = 0; i < 4; i++) {
+				char *end;
+				long int value = strtol(src, &end, 10);
+				if (value > 255)
+					return 0;
+				if (*end != '\0' && *end != '.')
+					return 0;
+				src = end + 1;
+				array[i] = value;
+			}
+			auto addr = reinterpret_cast<struct in_addr*>(dst);
+			memcpy(&addr->s_addr, array, 4);
+			break;
+		}
+		case AF_INET6:
+			mlibc::infoLogger() << "inet_pton: ipv6 is not implemented!" << frg::endlog;
+			/* fallthrough */
+		default:
+			errno = EAFNOSUPPORT;
+			return -1;
+	}
+
+	return 1;
+}
+
+struct in_addr inet_makeaddr(in_addr_t, in_addr_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+in_addr_t inet_netof(struct in_addr) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/dirent-stubs.cpp b/lib/mlibc/options/posix/generic/dirent-stubs.cpp
new file mode 100644
index 0000000..1352585
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/dirent-stubs.cpp
@@ -0,0 +1,180 @@
+
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+
+#include <bits/ensure.h>
+#include <frg/allocation.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+// Code taken from musl
+int alphasort(const struct dirent **a, const struct dirent **b) {
+	return strcoll((*a)->d_name, (*b)->d_name);
+}
+
+int closedir(DIR *dir) {
+	// TODO: Deallocate the dir structure.
+	close(dir->__handle);
+	return 0;
+}
+int dirfd(DIR *dir) {
+	return dir->__handle;
+}
+DIR *fdopendir(int fd) {
+	struct stat st;
+
+	if(fstat(fd, &st) < 0) {
+		return nullptr;
+	}
+	// Musl implements this, but O_PATH is only declared on the linux abi
+	/*if(fcntl(fd, F_GETFL) & O_PATH) {
+		errno = EBADF;
+		return nullptr;
+	}*/
+	if(!S_ISDIR(st.st_mode)) {
+		errno = ENOTDIR;
+		return nullptr;
+	}
+	auto dir = frg::construct<__mlibc_dir_struct>(getAllocator());
+	__ensure(dir);
+	dir->__ent_next = 0;
+	dir->__ent_limit = 0;
+	int flags = fcntl(fd, F_GETFD);
+	fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+	dir->__handle = fd;
+	return dir;
+}
+DIR *opendir(const char *path) {
+	auto dir = frg::construct<__mlibc_dir_struct>(getAllocator());
+	__ensure(dir);
+	dir->__ent_next = 0;
+	dir->__ent_limit = 0;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_open_dir, nullptr);
+	if(int e = mlibc::sys_open_dir(path, &dir->__handle); e) {
+		errno = e;
+		frg::destruct(getAllocator(), dir);
+		return nullptr;
+	}else{
+		return dir;
+	}
+}
+struct dirent *readdir(DIR *dir) {
+	__ensure(dir->__ent_next <= dir->__ent_limit);
+	if(dir->__ent_next == dir->__ent_limit) {
+		MLIBC_CHECK_OR_ENOSYS(mlibc::sys_read_entries, nullptr);
+		if(int e = mlibc::sys_read_entries(dir->__handle, dir->__ent_buffer, 2048, &dir->__ent_limit); e)
+			__ensure(!"mlibc::sys_read_entries() failed");
+		dir->__ent_next = 0;
+		if(!dir->__ent_limit)
+			return nullptr;
+	}
+
+	auto entp = reinterpret_cast<struct dirent *>(dir->__ent_buffer + dir->__ent_next);
+	// We only copy as many bytes as we need to avoid buffer-overflows.
+	memcpy(&dir->__current, entp, offsetof(struct dirent, d_name) + strlen(entp->d_name) + 1);
+	dir->__ent_next += entp->d_reclen;
+	return &dir->__current;
+}
+int readdir_r(DIR *dir, struct dirent *entry, struct dirent **result) {
+	if(!mlibc::sys_read_entries) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	__ensure(dir->__ent_next <= dir->__ent_limit);
+	if(dir->__ent_next == dir->__ent_limit) {
+		if(int e = mlibc::sys_read_entries(dir->__handle, dir->__ent_buffer, 2048, &dir->__ent_limit); e)
+			__ensure(!"mlibc::sys_read_entries() failed");
+		dir->__ent_next = 0;
+		if(!dir->__ent_limit) {
+			*result = NULL;
+			return 0;
+		}
+	}
+
+	auto entp = reinterpret_cast<struct dirent *>(dir->__ent_buffer + dir->__ent_next);
+	// We only copy as many bytes as we need to avoid buffer-overflows.
+	memcpy(entry, entp, offsetof(struct dirent, d_name) + strlen(entp->d_name) + 1);
+	dir->__ent_next += entp->d_reclen;
+	*result = entry;
+	return 0;
+}
+
+void rewinddir(DIR *dir) {
+	lseek(dir->__handle, 0, SEEK_SET);
+	dir->__ent_next = 0;
+}
+
+int scandir(const char *path, struct dirent ***res, int (*select)(const struct dirent *),
+		int (*compare)(const struct dirent **, const struct dirent **)) {
+	DIR *dir = opendir(path);
+	if (!dir)
+		return -1; // errno will be set by opendir()
+
+	// we should save the errno
+	int old_errno = errno;
+	errno = 0;
+
+	struct dirent *dir_ent;
+	struct dirent **array = nullptr, **tmp = nullptr;
+	int length = 0;
+	int count = 0;
+	while((dir_ent = readdir(dir)) && !errno) {
+		if(select && !select(dir_ent))
+			continue;
+
+		if(count >= length) {
+			length = 2*length + 1;
+			tmp = static_cast<struct dirent**>(realloc(array,
+						length * sizeof(struct dirent*)));
+			// we need to check the call actually goes through
+			// before we overwrite array so that we can
+			// deallocate the already written entries should realloc()
+			// have failed
+			if(!tmp)
+				break;
+			array = tmp;
+		}
+		array[count] = static_cast<struct dirent*>(malloc(dir_ent->d_reclen));
+		if(!array[count])
+			break;
+
+		memcpy(array[count], dir_ent, dir_ent->d_reclen);
+		count++;
+	}
+
+	if(errno) {
+		if(array)
+			while(count-- > 0)
+				free(array[count]);
+		free(array);
+		return -1;
+	}
+
+	// from here we can set the old errno back
+	errno = old_errno;
+
+	if(compare)
+		qsort(array, count, sizeof(struct dirent*),
+				(int (*)(const void *, const void *)) compare);
+	*res = array;
+	return count;
+}
+void seekdir(DIR *, long) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+long telldir(DIR *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int versionsort(const struct dirent **a, const struct dirent **b) {
+	return strverscmp((*a)->d_name, (*b)->d_name);
+}
diff --git a/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp b/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp
new file mode 100644
index 0000000..fc9fd84
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp
@@ -0,0 +1,64 @@
+
+#include <bits/ensure.h>
+#include <dlfcn.h>
+
+#include <mlibc/debug.hpp>
+
+struct __dlapi_symbol {
+	const char *file;
+	void *base;
+	const char *symbol;
+	void *address;
+};
+
+extern "C" const char *__dlapi_error();
+extern "C" void *__dlapi_open(const char *, int, void *);
+extern "C" void *__dlapi_resolve(void *, const char *, void *);
+extern "C" int __dlapi_reverse(const void *, __dlapi_symbol *);
+extern "C" int __dlapi_close(void *);
+
+int dlclose(void *handle) {
+	return __dlapi_close(handle);
+}
+
+char *dlerror(void) {
+	return const_cast<char *>(__dlapi_error());
+}
+
+[[gnu::noinline]]
+void *dlopen(const char *file, int flags) {
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_open(file, flags, ra);
+}
+
+[[gnu::noinline]]
+void *dlsym(void *__restrict handle, const char *__restrict string) {
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_resolve(handle, string, ra);
+}
+
+[[gnu::noinline]]
+void *dlvsym(void *__restrict handle, const char *__restrict string, const char *__restrict version) {
+	mlibc::infoLogger() << "mlibc: dlvsym ignores version " << version << frg::endlog;
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_resolve(handle, string, ra);
+}
+
+//gnu extensions
+int dladdr(const void *ptr, Dl_info *out) {
+	__dlapi_symbol info;
+	if(__dlapi_reverse(ptr, &info))
+		return 0;
+
+	out->dli_fname = info.file;
+	out->dli_fbase = info.base;
+	out->dli_sname = info.symbol;
+	out->dli_saddr = info.address;
+	return 1;
+}
+
+int dlinfo(void *, int, void *) {
+	__ensure(!"dlinfo() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/fcntl-stubs.cpp b/lib/mlibc/options/posix/generic/fcntl-stubs.cpp
new file mode 100644
index 0000000..66e2d12
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/fcntl-stubs.cpp
@@ -0,0 +1,108 @@
+
+#include <errno.h>
+#include <bits/ensure.h>
+#include <fcntl.h>
+#include <stdarg.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int creat(const char *pathname, mode_t mode) {
+	return open(pathname, O_CREAT|O_WRONLY|O_TRUNC, mode);
+}
+
+int fallocate(int, int, off_t, off_t) {
+	mlibc::infoLogger() << "mlibc: fallocate() is a no-op" << frg::endlog;
+	errno = ENOSYS;
+	return -1;
+}
+
+int fcntl(int fd, int command, ...) {
+	va_list args;
+	va_start(args, command);
+	int result;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fcntl, -1);
+	if(int e = mlibc::sys_fcntl(fd, command, args, &result); e) {
+		errno = e;
+		return -1;
+	}
+	va_end(args);
+	return result;
+}
+
+int openat(int dirfd, const char *pathname, int flags, ...) {
+	va_list args;
+	va_start(args, flags);
+	mode_t mode = 0;
+	int fd;
+
+	if((flags & (O_CREAT | O_TMPFILE)))
+		mode = va_arg(args, mode_t);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_openat, -1);
+	if(int e = mlibc::sys_openat(dirfd, pathname, flags, mode, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	va_end(args);
+	return fd;
+}
+
+int posix_fadvise(int fd, off_t offset, off_t length, int advice) {
+	if(!mlibc::sys_fadvise) {
+		mlibc::infoLogger() << "mlibc: fadvise() ignored due to missing sysdep" << frg::endlog;
+		return 0;
+	}
+
+	// posix_fadvise() returns an error instead of setting errno.
+	return mlibc::sys_fadvise(fd, offset, length, advice);
+}
+
+int posix_fallocate(int fd, off_t offset, off_t size) {
+	// posix_fallocate() returns an error instead of setting errno.
+	if(!mlibc::sys_fallocate) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+	return mlibc::sys_fallocate(fd, offset, size);
+}
+
+// This is a linux extension
+int name_to_handle_at(int, const char *, struct file_handle *, int *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int open_by_handle_at(int, struct file_handle *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t splice(int, off_t *, int, off_t *, size_t, unsigned int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t vmsplice(int, const struct iovec *, size_t, unsigned int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int open(const char *pathname, int flags, ...) {
+	mode_t mode = 0;
+
+	if ((flags & O_CREAT) || (flags & O_TMPFILE)) {
+		va_list args;
+		va_start(args, flags);
+		mode = va_arg(args, mode_t);
+		va_end(args);
+	}
+
+	int fd;
+	if(int e = mlibc::sys_open(pathname, flags, mode, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	return fd;
+}
+
diff --git a/lib/mlibc/options/posix/generic/ftw-stubs.cpp b/lib/mlibc/options/posix/generic/ftw-stubs.cpp
new file mode 100644
index 0000000..2d93995
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/ftw-stubs.cpp
@@ -0,0 +1,18 @@
+
+#include <ftw.h>
+
+#include <bits/ensure.h>
+
+int ftw(const char *, int (*fn)(const char *, const struct stat *, int), int) {
+	(void)fn;
+	__ensure(!"ftw() not implemented");
+	__builtin_unreachable();
+}
+
+int nftw(const char *, int (*fn)(const char *, const struct stat *, int, struct FTW *),
+		int, int) {
+	(void)fn;
+	__ensure(!"nftw() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/grp-stubs.cpp b/lib/mlibc/options/posix/generic/grp-stubs.cpp
new file mode 100644
index 0000000..f8b2813
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/grp-stubs.cpp
@@ -0,0 +1,316 @@
+
+#include <grp.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+namespace {
+	FILE *global_file;
+
+	bool open_global_file() {
+		if(!global_file) {
+			global_file = fopen("/etc/group", "r");
+			if(!global_file) {
+				errno = EIO;
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	void close_global_file() {
+		if(global_file) {
+			fclose(global_file);
+			global_file = nullptr;
+		}
+	}
+
+	template<typename F>
+	void walk_segments(frg::string_view line, char delimiter, F fn) {
+		size_t s = 0;
+		while(true) {
+			size_t d = line.find_first(delimiter, s);
+			if(d == size_t(-1))
+				break;
+			auto chunk = line.sub_string(s, d - s);
+			fn(chunk);
+			s = d + 1;
+		}
+		if(line[s]) {
+			auto chunk = line.sub_string(s, line.size() - s);
+
+			if (chunk.size() > 0) {
+				// Remove trailing newline
+				if (chunk[chunk.size() - 1] == '\n')
+					chunk = chunk.sub_string(0, chunk.size() - 1);
+
+				fn(chunk);
+			}
+		}
+	}
+
+	bool extract_entry(frg::string_view line, group *entry) {
+		frg::string_view segments[5];
+
+		// Parse the line into 3 or 4 segments (depending if the group has members or not)
+		int n = 0;
+		walk_segments(line, ':', [&] (frg::string_view s) {
+			__ensure(n < 4);
+			segments[n++] = s;
+		});
+
+		if(n < 3) // n can be 3 when there are no members in the group
+			return false;
+
+		// TODO: Handle strndup() and malloc() failure.
+		auto name = strndup(segments[0].data(), segments[0].size());
+		__ensure(name);
+
+		auto passwd = strndup(segments[1].data(), segments[1].size());
+
+		auto gid = segments[2].to_number<int>();
+		if(!gid)
+			return false;
+
+		size_t n_members = 0;
+		walk_segments(segments[3], ',', [&] (frg::string_view) {
+			n_members++;
+		});
+
+		auto members = reinterpret_cast<char **>(malloc(sizeof(char *) * (n_members + 1)));
+		__ensure(members);
+		size_t k = 0;
+		walk_segments(segments[3], ',', [&] (frg::string_view m) {
+			members[k] = strndup(m.data(), m.size());
+			__ensure(members[k]);
+			k++;
+		});
+		members[k] = nullptr;
+
+		entry->gr_name = name;
+		entry->gr_passwd = passwd;
+		entry->gr_gid = *gid;
+		entry->gr_mem = members;
+		return true;
+	}
+
+	void clear_entry(group *entry) {
+		free(entry->gr_name);
+		if(entry->gr_mem) {
+			for(size_t i = 0; entry->gr_mem[i]; i++)
+				free(entry->gr_mem[i]);
+			free(entry->gr_mem);
+		}
+		entry->gr_name = nullptr;
+		entry->gr_mem = nullptr;
+	}
+
+	template<typename C>
+	int walk_file(struct group *entry, C cond) {
+		auto file = fopen("/etc/group", "r");
+		if(!file) {
+			return EIO;
+		}
+
+		char line[512];
+		while(fgets(line, 512, file)) {
+			if(!extract_entry(line, entry))
+				continue;
+			if(cond(entry)) {
+				fclose(file);
+				return 0;
+			}
+		}
+
+		int err = ESRCH;
+		if(ferror(file)) {
+			err = EIO;
+		}
+
+		fclose(file);
+		return err;
+	}
+
+	int copy_to_buffer(struct group *grp, char *buffer, size_t size) {
+		// Adjust to correct alignment so that we can put gr_mem first in buffer
+		uintptr_t mask = sizeof(char *) - 1;
+		size_t offset = (reinterpret_cast<uintptr_t>(buffer) % sizeof(char *) + mask) & ~mask;
+		if (size < offset)
+			return ERANGE;
+
+		buffer += offset;
+		size -= offset;
+
+		// Calculate the amount of space we need
+		size_t nmemb, required_size = 0;
+		for (nmemb = 0; grp->gr_mem[nmemb] != nullptr; nmemb++) {
+			// One for the string's null terminator and one for the pointer in gr_mem
+			required_size += strlen(grp->gr_mem[nmemb]) + 1 + sizeof(char *);
+		}
+
+		// One for null terminator of gr_name, plus sizeof(char *) for nullptr terminator of gr_mem
+		required_size += strlen(grp->gr_name) + 1 + sizeof(char *);
+		if (size < required_size)
+			return ERANGE;
+
+		// Put the gr_mem array first in the buffer as we are guaranteed
+		// that the pointer is aligned correctly
+		char *string_data = buffer + (nmemb + 1) * sizeof(char *);
+
+		for (size_t i = 0; i < nmemb; i++) {
+			reinterpret_cast<char **>(buffer)[i] = string_data;
+			string_data = stpcpy(string_data, grp->gr_mem[i]) + 1;
+			free(grp->gr_mem[i]);
+		}
+
+		reinterpret_cast<char **>(buffer)[nmemb] = nullptr;
+		free(grp->gr_mem);
+		grp->gr_mem = reinterpret_cast<char **>(buffer);
+
+		char *gr_name = stpcpy(string_data, grp->gr_name) + 1;
+		free(grp->gr_name);
+		grp->gr_name = string_data;
+
+		__ensure(gr_name <= buffer + size);
+		return 0;
+	}
+}
+
+void endgrent(void) {
+	close_global_file();
+}
+
+struct group *getgrent(void) {
+	static group entry;
+	char line[512];
+
+	if(!open_global_file()) {
+		return nullptr;
+	}
+
+	if(fgets(line, 512, global_file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry)) {
+			errno = EINVAL;
+			return nullptr;
+		}
+		return &entry;
+	}
+
+	if(ferror(global_file)) {
+		errno = EIO;
+	}
+
+	return nullptr;
+}
+
+struct group *getgrgid(gid_t gid) {
+	static group entry;
+
+	int err = walk_file(&entry, [&] (group *entry) {
+		return entry->gr_gid == gid;
+	});
+
+	if (err) {
+		errno = err;
+		return nullptr;
+	}
+
+	return &entry;
+}
+
+int getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t size, struct group **result) {
+	*result = nullptr;
+	int err = walk_file(grp, [&] (group *entry) {
+		return entry->gr_gid == gid;
+	});
+
+	if (err) {
+		return err;
+	}
+
+	err = copy_to_buffer(grp, buffer, size);
+	if (err) {
+		return err;
+	}
+
+	*result = grp;
+	return 0;
+}
+
+struct group *getgrnam(const char *name) {
+	static group entry;
+
+	int err = walk_file(&entry, [&] (group *entry) {
+		return !strcmp(entry->gr_name, name);
+	});
+
+	if (err) {
+		errno = err;
+		return nullptr;
+	}
+
+	return &entry;
+}
+
+int getgrnam_r(const char *name, struct group *grp, char *buffer, size_t size, struct group **result) {
+	*result = nullptr;
+
+	int err = walk_file(grp, [&] (group *entry) {
+		return !strcmp(entry->gr_name, name);
+	});
+
+	if (err) {
+		return err;
+	}
+
+	err = copy_to_buffer(grp, buffer, size);
+	if (err) {
+		return err;
+	}
+
+	*result = grp;
+	return 0;
+}
+
+void setgrent(void) {
+	if(!open_global_file()) {
+		return;
+	}
+	rewind(global_file);
+}
+
+int setgroups(size_t size, const gid_t *list) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setgroups, -1);
+	if(int e = mlibc::sys_setgroups(size, list); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int initgroups(const char *, gid_t) {
+	mlibc::infoLogger() << "mlibc: initgroups is a stub" << frg::endlog;
+	return 0;
+}
+
+int putgrent(const struct group *, FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct group *fgetgrent(FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getgrouplist(const char *, gid_t, gid_t *, int *) {
+	mlibc::infoLogger() << "mlibc: getgrouplist is a stub" << frg::endlog;
+	return 0;
+}
diff --git a/lib/mlibc/options/posix/generic/langinfo-stubs.cpp b/lib/mlibc/options/posix/generic/langinfo-stubs.cpp
new file mode 100644
index 0000000..b239cbd
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/langinfo-stubs.cpp
@@ -0,0 +1,15 @@
+
+#include <langinfo.h>
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/locale.hpp>
+
+char *nl_langinfo(nl_item item) {
+	return mlibc::nl_langinfo(item);
+}
+
+char *nl_langinfo_l(nl_item, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/libgen-stubs.cpp b/lib/mlibc/options/posix/generic/libgen-stubs.cpp
new file mode 100644
index 0000000..ff80349
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/libgen-stubs.cpp
@@ -0,0 +1,51 @@
+
+#include <bits/ensure.h>
+#include <libgen.h>
+#include <string.h>
+
+#include <mlibc/debug.hpp>
+
+// Adopted from musl's code.
+char *basename(char *s) {
+	// This empty string behavior is specified by POSIX.
+	if (!s || !*s)
+		return const_cast<char *>(".");
+	
+	// Delete trailing slashes.
+	// Note that we do not delete the slash at index zero.
+	auto i = strlen(s) - 1;
+	for(; i && s[i] == '/'; i--)
+		s[i] = 0;
+
+	// Find the last non-trailing slash.
+	for(; i && s[i - 1] != '/'; i--)
+		;
+	return s + i;
+}
+
+char *dirname(char *s) {
+	if (!s || !(*s))
+		return const_cast<char *>(".");
+
+	auto i = strlen(s) - 1;
+
+	// Skip trailing slashes.
+	for (; s[i] == '/'; i--)
+		if(!i) // Path only consists of slashes.
+			return const_cast<char *>("/");
+
+	// Skip the last non-slash path component.
+	for (; s[i] != '/'; i--)
+		if(!i) // Path only contains a single component.
+			return const_cast<char *>(".");
+
+	// Skip slashes.
+	for (; s[i] == '/'; i--)
+		if(!i) // Path is entry in root directory.
+			return const_cast<char *>("/");
+
+	s[i+1] = 0;
+
+	return s;
+}
+
diff --git a/lib/mlibc/options/posix/generic/lookup.cpp b/lib/mlibc/options/posix/generic/lookup.cpp
new file mode 100644
index 0000000..f877fe5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/lookup.cpp
@@ -0,0 +1,512 @@
+#include <mlibc/lookup.hpp>
+#include <mlibc/resolv_conf.hpp>
+#include <mlibc/debug.hpp>
+#include <bits/ensure.h>
+
+#include <frg/string.hpp>
+#include <mlibc/allocator.hpp>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <ctype.h>
+
+namespace mlibc {
+
+namespace {
+	constexpr unsigned int RECORD_A = 1;
+	constexpr unsigned int RECORD_CNAME = 5;
+	constexpr unsigned int RECORD_PTR = 12;
+}
+
+static frg::string<MemoryAllocator> read_dns_name(char *buf, char *&it) {
+	frg::string<MemoryAllocator> res{getAllocator()};
+	while (true) {
+		char code = *it++;
+		if ((code & 0xC0) == 0xC0) {
+			// pointer
+			uint8_t offset = ((code & 0x3F) << 8) | *it++;
+			auto offset_it = buf + offset;
+			return res + read_dns_name(buf, offset_it);
+		} else if (!(code & 0xC0)) {
+			if (!code)
+				break;
+
+			for (int i = 0; i < code; i++)
+				res += (*it++);
+
+			if (*it)
+				res += '.';
+		} else {
+			break;
+		}
+	}
+
+	return res;
+}
+
+int lookup_name_dns(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name) {
+	frg::string<MemoryAllocator> request{getAllocator()};
+
+	int num_q = 1;
+	struct dns_header header;
+	header.identification = htons(123);
+	header.flags = htons(0x100);
+	header.no_q = htons(num_q);
+	header.no_ans = htons(0);
+	header.no_auths = htons(0);
+	header.no_additional = htons(0);
+
+	request.resize(sizeof(header));
+	memcpy(request.data(), &header, sizeof(header));
+
+	const char *end = name;
+	while (*end != '\0') {
+		end = strchrnul(name, '.');
+		size_t length = end - name;
+		frg::string_view substring{name, length};
+		name += length + 1;
+		request += char(length);
+		request += substring;
+	}
+
+	request += char(0);
+	// set question type to fetch A records
+	request += 0;
+	request += 1;
+	// set CLASS to IN
+	request += 0;
+	request += 1;
+
+	struct sockaddr_in sin = {};
+	sin.sin_family = AF_INET;
+	// TODO(geert): we could probably make this use the service lookup
+	// for dns
+	sin.sin_port = htons(53);
+
+	auto nameserver = get_nameserver();
+	if (!inet_aton(nameserver ? nameserver->name.data() : "127.0.0.1", &sin.sin_addr)) {
+		mlibc::infoLogger() << "lookup_name_dns(): inet_aton() failed!" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	int fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		mlibc::infoLogger() << "lookup_name_dns(): socket() failed" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	size_t sent = sendto(fd, request.data(), request.size(), 0,
+			(struct sockaddr*)&sin, sizeof(sin));
+	if (sent != request.size()) {
+		mlibc::infoLogger() << "lookup_name_dns(): sendto() failed to send everything" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	char response[256];
+	ssize_t rlen;
+	int num_ans = 0;
+	while ((rlen = recvfrom(fd, response, 256, 0, NULL, NULL)) >= 0) {
+		if ((size_t)rlen < sizeof(struct dns_header))
+			continue;
+		auto response_header = reinterpret_cast<struct dns_header*>(response);
+		if (response_header->identification != header.identification)
+			return -EAI_FAIL;
+
+		auto it = response + sizeof(struct dns_header);
+		for (int i = 0; i < ntohs(response_header->no_q); i++) {
+			auto dns_name = read_dns_name(response, it);
+			(void) dns_name;
+			it += 4;
+		}
+
+		for (int i = 0; i < ntohs(response_header->no_ans); i++) {
+			struct dns_addr_buf buffer;
+			auto dns_name = read_dns_name(response, it);
+
+			uint16_t rr_type = (it[0] << 8) | it[1];
+			uint16_t rr_class = (it[2] << 8) | it[3];
+			uint16_t rr_length = (it[8] << 8) | it[9];
+			it += 10;
+			(void)rr_class;
+
+			switch (rr_type) {
+				case RECORD_A:
+					memcpy(buffer.addr, it, rr_length);
+					it += rr_length;
+					buffer.family = AF_INET;
+					buffer.name = std::move(dns_name);
+					buf.buf.push(std::move(buffer));
+					break;
+				case RECORD_CNAME:
+					canon_name = read_dns_name(response, it);
+					buf.aliases.push(std::move(dns_name));
+					break;
+				default:
+					mlibc::infoLogger() << "lookup_name_dns: unknown rr type "
+						<< rr_type << frg::endlog;
+					break;
+			}
+		}
+		num_ans += ntohs(response_header->no_ans);
+
+		if (num_ans >= num_q)
+			break;
+	}
+
+	close(fd);
+	return buf.buf.size();
+}
+
+int lookup_addr_dns(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family) {
+	frg::string<MemoryAllocator> request{getAllocator()};
+
+	int num_q = 1;
+	struct dns_header header;
+	header.identification = htons(123);
+	header.flags = htons(0x100);
+	header.no_q = htons(num_q);
+	header.no_ans = htons(0);
+	header.no_auths = htons(0);
+	header.no_additional = htons(0);
+
+	request.resize(sizeof(header));
+	memcpy(request.data(), &header, sizeof(header));
+
+	char addr_str[64];
+	if(!inet_ntop(family, addr.data(), addr_str, sizeof(addr_str))) {
+		switch(errno) {
+			case EAFNOSUPPORT:
+				return -EAI_FAMILY;
+			case ENOSPC:
+				return -EAI_OVERFLOW;
+			default:
+				return -EAI_FAIL;
+		}
+	}
+	frg::string<MemoryAllocator> req_str{getAllocator(), addr_str};
+	req_str += ".in-addr.arpa";
+
+	frg::string_view req_view{req_str.data(), req_str.size()};
+	size_t ptr = 0;
+	do {
+		size_t next = req_view.find_first('.', ptr);
+		size_t length = next != (size_t)-1 ? next - ptr : req_view.size() - ptr;
+		frg::string_view substring = req_view.sub_string(ptr, length);
+		request += char(length);
+		request += substring;
+		ptr = next + 1;
+	} while(ptr != 0);
+
+	request += char(0);
+	// set question type to fetch PTR records
+	request += 0;
+	request += 12;
+	// set CLASS to IN
+	request += 0;
+	request += 1;
+
+
+	struct sockaddr_in sin = {};
+	sin.sin_family = AF_INET;
+	// TODO(geert): we could probably make this use the service lookup
+	// for dns
+	sin.sin_port = htons(53);
+
+	auto nameserver = get_nameserver();
+	if (!inet_aton(nameserver ? nameserver->name.data() : "127.0.0.1", &sin.sin_addr)) {
+		mlibc::infoLogger() << "lookup_name_dns(): inet_aton() failed!" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	int fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		mlibc::infoLogger() << "lookup_name_dns(): socket() failed" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	size_t sent = sendto(fd, request.data(), request.size(), 0,
+			(struct sockaddr*)&sin, sizeof(sin));
+	if (sent != request.size()) {
+		mlibc::infoLogger() << "lookup_name_dns(): sendto() failed to send everything" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	char response[256];
+	ssize_t rlen;
+	int num_ans = 0;
+	while ((rlen = recvfrom(fd, response, 256, 0, NULL, NULL)) >= 0) {
+		if ((size_t)rlen < sizeof(struct dns_header))
+			continue;
+		auto response_header = reinterpret_cast<struct dns_header*>(response);
+		if (response_header->identification != header.identification)
+			return -EAI_FAIL;
+
+		auto it = response + sizeof(struct dns_header);
+		for (int i = 0; i < ntohs(response_header->no_q); i++) {
+			auto dns_name = read_dns_name(response, it);
+			(void) dns_name;
+			it += 4;
+		}
+
+		for (int i = 0; i < ntohs(response_header->no_ans); i++) {
+			struct dns_addr_buf buffer;
+			auto dns_name = read_dns_name(response, it);
+
+			uint16_t rr_type = (it[0] << 8) | it[1];
+			uint16_t rr_class = (it[2] << 8) | it[3];
+			uint16_t rr_length = (it[8] << 8) | it[9];
+			it += 10;
+			(void)rr_class;
+			(void)rr_length;
+
+			(void)dns_name;
+
+			switch (rr_type) {
+				case RECORD_PTR: {
+					auto ptr_name = read_dns_name(response, it);
+					if (ptr_name.size() >= name.size())
+						return -EAI_OVERFLOW;
+					std::copy(ptr_name.begin(), ptr_name.end(), name.data());
+					name.data()[ptr_name.size()] = '\0';
+					return 1;
+				}
+				default:
+					mlibc::infoLogger() << "lookup_addr_dns: unknown rr type "
+						<< rr_type << frg::endlog;
+					break;
+			}
+			num_ans += ntohs(response_header->no_ans);
+
+			if (num_ans >= num_q)
+				break;
+		}
+	}
+
+	close(fd);
+	return 0;
+}
+
+int lookup_name_hosts(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name) {
+	auto file = fopen("/etc/hosts", "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line[128];
+	int name_length = strlen(name);
+	while (fgets(line, 128, file)) {
+		char *pos;
+		// same way to deal with comments as in services.cpp
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		for(pos = line + 1; (pos = strstr(pos, name)) &&
+				(!isspace(pos[-1]) || !isspace(pos[name_length])); pos++);
+		if (!pos)
+			continue;
+
+		for (pos = line; !isspace(*pos); pos++);
+		*pos = '\0';
+
+		// TODO(geert): we assume ipv4 for now
+		struct in_addr addr;
+		if (!inet_aton(line, &addr))
+			continue;
+
+		pos++;
+		for(; *pos && isspace(*pos); pos++);
+		char *end;
+		for(end = pos; *end && !isspace(*end); end++);
+
+		struct dns_addr_buf buffer;
+		memcpy(buffer.addr, &addr, 4);
+		buffer.family = AF_INET;
+		buffer.name = frg::string<MemoryAllocator>{pos,
+			static_cast<size_t>(end - pos), getAllocator()};
+		canon_name = buffer.name;
+
+		buf.buf.push(std::move(buffer));
+
+		pos = end;
+		while (pos[1]) {
+			for (; *pos && isspace(*pos); pos++);
+			for (end = pos; *end && !isspace(*end); end++);
+			auto name = frg::string<MemoryAllocator>{pos,
+				static_cast<size_t>(end - pos), getAllocator()};
+			buf.aliases.push(std::move(name));
+			pos = end;
+		}
+	}
+
+	fclose(file);
+	return buf.buf.size();
+}
+
+int lookup_addr_hosts(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family) {
+	auto file = fopen("/etc/hosts", "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	// Buffer to hold ASCII version of address
+	char addr_str[64];
+	if(!inet_ntop(family, addr.data(), addr_str, sizeof(addr_str))) {
+		switch(errno) {
+			case EAFNOSUPPORT:
+				return -EAI_FAMILY;
+			case ENOSPC:
+				return -EAI_OVERFLOW;
+			default:
+				return -EAI_FAIL;
+		}
+	}
+	int addr_str_len = strlen(addr_str);
+
+	char line[128];
+	while (fgets(line, 128, file)) {
+		char *pos;
+		// same way to deal with comments as in services.cpp
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+		if (strncmp(line, addr_str, addr_str_len))
+			continue;
+
+		for (pos = line + addr_str_len + 1; isspace(*pos); pos++);
+		char *begin = pos;
+		for (; !isspace(*pos); pos++);
+		char *end = pos;
+
+		size_t size = end - begin;
+		if (size >= name.size())
+			return -EAI_OVERFLOW;
+		std::copy(begin, end, name.data());
+		name.data()[size] = '\0';
+		return 1;
+	}
+	return 0;
+}
+
+int lookup_name_null(struct lookup_result &buf, int flags, int family) {
+	if (flags & AI_PASSIVE) {
+		if (family != AF_INET6) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET;
+
+			in_addr_t addr = INADDR_ANY;
+			memcpy(&addr_buf.addr, &addr, 4);
+
+			buf.buf.push_back(addr_buf);
+		}
+		if (family != AF_INET) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET6;
+
+			struct in6_addr addr = IN6ADDR_ANY_INIT;
+			memcpy(&addr_buf.addr, &addr, 16);
+
+			buf.buf.push_back(addr_buf);
+		}
+	} else {
+		if (family != AF_INET6) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET;
+
+			in_addr_t addr = INADDR_LOOPBACK;
+			memcpy(&addr_buf.addr, &addr, 4);
+
+			buf.buf.push_back(addr_buf);
+		}
+		if (family != AF_INET) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET6;
+
+			struct in6_addr addr = IN6ADDR_LOOPBACK_INIT;
+			memcpy(&addr_buf.addr, &addr, 16);
+
+			buf.buf.push_back(addr_buf);
+		}
+	}
+	return buf.buf.size();
+}
+
+int lookup_name_ip(struct lookup_result &buf, const char *name, int family) {
+	if (family == AF_INET) {
+		in_addr_t addr = 0;
+		int res = inet_pton(AF_INET, name, &addr);
+
+		if (res <= 0)
+			return -EAI_NONAME;
+
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET;
+		memcpy(&addr_buf.addr, &addr, 4);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	if (family == AF_INET6) {
+		struct in6_addr addr{0};
+		int res = inet_pton(AF_INET6, name, &addr);
+
+		if (res <= 0)
+			return -EAI_NONAME;
+
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET6;
+		memcpy(&addr_buf.addr, &addr, 16);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	// If no family was specified we try ipv4 and then ipv6.
+	in_addr_t addr4 = 0;
+	int res = inet_pton(AF_INET, name, &addr4);
+
+	if (res > 0) {
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET;
+		memcpy(&addr_buf.addr, &addr4, 4);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	struct in6_addr addr6{0};
+	res = inet_pton(AF_INET6, name, &addr6);
+
+	if (res <= 0)
+		return -EAI_NONAME;
+
+	struct dns_addr_buf addr_buf;
+	addr_buf.family = AF_INET6;
+	memcpy(&addr_buf.addr, &addr6, 16);
+
+	buf.buf.push_back(addr_buf);
+	return 1;
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/mqueue.cpp b/lib/mlibc/options/posix/generic/mqueue.cpp
new file mode 100644
index 0000000..d635419
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/mqueue.cpp
@@ -0,0 +1,22 @@
+#include <mqueue.h>
+#include <bits/ensure.h>
+
+int mq_getattr(mqd_t, struct mq_attr *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int mq_setattr(mqd_t, const struct mq_attr *__restrict__, struct mq_attr *__restrict__) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int mq_unlink(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+mqd_t mq_open(const char *, int, ...) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/net-if-stubs.cpp b/lib/mlibc/options/posix/generic/net-if-stubs.cpp
new file mode 100644
index 0000000..6a65a5c
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/net-if-stubs.cpp
@@ -0,0 +1,40 @@
+#include <errno.h>
+#include <net/if.h>
+#include <stdlib.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+void if_freenameindex(struct if_nameindex *) {
+	mlibc::infoLogger() << "mlibc: if_freenameindex is a no-op" << frg::endlog;
+}
+
+char *if_indextoname(unsigned int index, char *name) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_if_indextoname, NULL);
+
+	if(int e = sysdep(index, name); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return name;
+}
+
+struct if_nameindex *if_nameindex(void) {
+	mlibc::infoLogger() << "mlibc: if_nameindex() is a no-op" << frg::endlog;
+	errno = ENOSYS;
+	return NULL;
+}
+
+unsigned int if_nametoindex(const char *name) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_if_nametoindex, 0);
+	unsigned int ret = 0;
+
+	if(int e = sysdep(name, &ret); e) {
+		errno = e;
+		return 0;
+	}
+
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/netdb-stubs.cpp b/lib/mlibc/options/posix/generic/netdb-stubs.cpp
new file mode 100644
index 0000000..455444b
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/netdb-stubs.cpp
@@ -0,0 +1,486 @@
+#include <netdb.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/lookup.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/services.hpp>
+#include <frg/vector.hpp>
+#include <frg/array.hpp>
+#include <frg/span.hpp>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <errno.h>
+
+__thread int __mlibc_h_errno;
+
+// This function is from musl
+int *__h_errno_location(void) {
+	return &__mlibc_h_errno;
+}
+
+void endhostent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endnetent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endprotoent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endservent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void freeaddrinfo(struct addrinfo *ptr) {
+	if (ptr) {
+		auto buf = (struct mlibc::ai_buf*) ptr - offsetof(struct mlibc::ai_buf, ai);
+		// this string was allocated by a frg::string
+		getAllocator().free(ptr->ai_canonname);
+		free(buf);
+	}
+}
+
+const char *gai_strerror(int code) {
+	static thread_local char buffer[128];
+	snprintf(buffer, sizeof(buffer), "Unknown error (%d)", code);
+	return buffer;
+}
+
+int getaddrinfo(const char *__restrict node, const char *__restrict service,
+		const struct addrinfo *__restrict hints, struct addrinfo **__restrict res) {
+	if (!node && !service)
+		return EAI_NONAME;
+
+	int socktype = 0, protocol = 0, family = AF_UNSPEC, flags = AI_V4MAPPED | AI_ADDRCONFIG;
+	if (hints) {
+		socktype = hints->ai_socktype;
+		protocol = hints->ai_protocol;
+		family = hints->ai_family;
+		flags = hints->ai_flags;
+
+		int mask = AI_V4MAPPED | AI_ADDRCONFIG | AI_NUMERICHOST | AI_PASSIVE |
+			AI_CANONNAME | AI_ALL | AI_NUMERICSERV;
+		if ((flags & mask) != flags)
+			return EAI_BADFLAGS;
+
+		if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC)
+			return EAI_FAMILY;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int serv_count = mlibc::lookup_serv_by_name(serv_buf, service, protocol, socktype, flags);
+	if (serv_count < 0)
+		return -serv_count;
+
+	struct mlibc::lookup_result addr_buf;
+	int addr_count = 1;
+	frg::string<MemoryAllocator> canon{getAllocator()};
+	if (node) {
+		if ((addr_count = mlibc::lookup_name_ip(addr_buf, node, family)) <= 0) {
+			if (flags & AI_NUMERICHOST)
+			       addr_count = -EAI_NONAME;
+			else if ((addr_count = mlibc::lookup_name_hosts(addr_buf, node, canon)) <= 0)
+				addr_count = mlibc::lookup_name_dns(addr_buf, node, canon);
+			else
+				addr_count = 1;
+		}
+
+		if (addr_count < 0)
+			return -addr_count;
+		if (!addr_count)
+			return EAI_NONAME;
+	} else {
+		/* There is no node specified */
+		if (flags & AI_NUMERICHOST)
+			return EAI_NONAME;
+		addr_count = lookup_name_null(addr_buf, flags, family);
+	}
+
+	auto out = (struct mlibc::ai_buf *) calloc(serv_count * addr_count,
+			sizeof(struct mlibc::ai_buf));
+
+	if (node && !canon.size())
+		canon = frg::string<MemoryAllocator>{node, getAllocator()};
+
+	for (int i = 0, k = 0; i < addr_count; i++) {
+		for (int j = 0; j < serv_count; j++, k++) {
+			out[i].ai.ai_family = addr_buf.buf[i].family;
+			out[i].ai.ai_socktype = serv_buf[j].socktype;
+			out[i].ai.ai_protocol = serv_buf[j].protocol;
+			out[i].ai.ai_flags = flags;
+			out[i].ai.ai_addr = (struct sockaddr *) &out[i].sa;
+			if (canon.size())
+				out[i].ai.ai_canonname = canon.data();
+			else
+				out[i].ai.ai_canonname = NULL;
+			out[i].ai.ai_next = NULL;
+			switch (addr_buf.buf[i].family) {
+				case AF_INET:
+					out[i].ai.ai_addrlen = sizeof(struct sockaddr_in);
+					out[i].sa.sin.sin_port = htons(serv_buf[j].port);
+					out[i].sa.sin.sin_family = AF_INET;
+					memcpy(&out[i].sa.sin.sin_addr, addr_buf.buf[i].addr, 4);
+					break;
+				case AF_INET6:
+					out[i].ai.ai_addrlen = sizeof(struct sockaddr_in6);
+					out[i].sa.sin6.sin6_family = htons(serv_buf[j].port);
+					out[i].sa.sin6.sin6_family = AF_INET6;
+					memcpy(&out[i].sa.sin6.sin6_addr, addr_buf.buf[i].addr, 16);
+					break;
+			}
+		}
+	}
+	if (canon.size())
+		canon.detach();
+
+	*res = &out[0].ai;
+	return 0;
+}
+
+struct hostent *gethostent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getnameinfo(const struct sockaddr *__restrict addr, socklen_t addr_len,
+		char *__restrict host, socklen_t host_len, char *__restrict serv,
+		socklen_t serv_len, int flags) {
+	frg::array<uint8_t, 16> addr_array;
+	int family = addr->sa_family;
+
+	switch(family) {
+		case AF_INET: {
+			if (addr_len < sizeof(struct sockaddr_in))
+				return EAI_FAMILY;
+			auto sockaddr = reinterpret_cast<const struct sockaddr_in*>(addr);
+			memcpy(addr_array.data(), reinterpret_cast<const char*>(&sockaddr->sin_addr), 4);
+			break;
+		}
+		case AF_INET6: {
+			mlibc::infoLogger() << "getnameinfo(): ipv6 is not fully supported in this function" << frg::endlog;
+			if (addr_len < sizeof(struct sockaddr_in6))
+				return EAI_FAMILY;
+			auto sockaddr = reinterpret_cast<const struct sockaddr_in6*>(addr);
+			memcpy(addr_array.data(), reinterpret_cast<const char*>(&sockaddr->sin6_addr), 16);
+			break;
+		}
+		default:
+			return EAI_FAMILY;
+	}
+
+	if (host && host_len) {
+		frg::span<char> host_span{host, host_len};
+		int res = 0;
+		if (!(flags & NI_NUMERICHOST))
+			res = mlibc::lookup_addr_hosts(host_span, addr_array, family);
+		if (!(flags & NI_NUMERICHOST) && !res)
+			res = mlibc::lookup_addr_dns(host_span, addr_array, family);
+
+		if (!res) {
+			if (flags & NI_NAMEREQD)
+				return EAI_NONAME;
+			if(!inet_ntop(family, addr_array.data(), host, host_len)) {
+				switch(errno) {
+					case EAFNOSUPPORT:
+						return EAI_FAMILY;
+					case ENOSPC:
+						return EAI_OVERFLOW;
+					default:
+						return EAI_FAIL;
+				}
+			}
+		}
+
+		if (res < 0)
+			return -res;
+	}
+
+	if (serv && serv_len) {
+		__ensure("getnameinfo(): not implemented service resolution yet!");
+		__builtin_unreachable();
+	}
+
+	return 0;
+}
+
+struct netent *getnetbyaddr(uint32_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct netent *getnetbyname(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct netent *getnetent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct hostent *gethostbyname(const char *name) {
+	if (!name) {
+		h_errno = HOST_NOT_FOUND;
+		return NULL;
+	}
+
+	struct mlibc::lookup_result buf;
+	frg::string<MemoryAllocator> canon{getAllocator()};
+	int ret = 0;
+	if ((ret = mlibc::lookup_name_hosts(buf, name, canon)) <= 0)
+		ret = mlibc::lookup_name_dns(buf, name, canon);
+	if (ret <= 0) {
+		h_errno = HOST_NOT_FOUND;
+		return NULL;
+	}
+
+	static struct hostent h;
+	if (h.h_name) {
+		getAllocator().free(h.h_name);
+		for (int i = 0; h.h_aliases[i] != NULL; i++)
+			getAllocator().free(h.h_aliases[i]);
+		free(h.h_aliases);
+
+		if (h.h_addr_list) {
+			for (int i = 0; h.h_addr_list[i] != NULL; i++)
+				free(h.h_addr_list[i]);
+			free(h.h_addr_list);
+		}
+	}
+	h = {};
+
+	if (!canon.size())
+		canon = frg::string<MemoryAllocator>{name, getAllocator()};
+
+	h.h_name = canon.data();
+
+	h.h_aliases = reinterpret_cast<char**>(malloc((buf.aliases.size() + 1)
+				* sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : buf.aliases) {
+		h.h_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	h.h_aliases[alias_pos] = NULL;
+	canon.detach();
+
+	// just pick the first family as the one for all addresses...??
+	h.h_addrtype = buf.buf[0].family;
+	if (h.h_addrtype != AF_INET && h.h_addrtype != AF_INET6) {
+		// this is not allowed per spec
+		h_errno = NO_DATA;
+		return NULL;
+	}
+
+	// can only be AF_INET or AF_INET6
+	h.h_length = h.h_addrtype == AF_INET ? 4 : 16;
+	h.h_addr_list = reinterpret_cast<char**>(malloc((ret + 1) * sizeof(char*)));
+	int addr_pos = 0;
+	for (int i = 0; i < ret; i++) {
+		if (buf.buf[i].family != h.h_addrtype)
+			continue;
+		h.h_addr_list[addr_pos] = reinterpret_cast<char*>(malloc(h.h_length));
+		memcpy(h.h_addr_list[addr_pos], buf.buf[i].addr, h.h_length);
+		addr_pos++;
+	}
+	h.h_addr_list[addr_pos] = NULL;
+
+	return &h;
+}
+
+struct hostent *gethostbyname2(const char *, int) {
+	__ensure(!"gethostbyname2() not implemented");
+	__builtin_unreachable();
+}
+
+struct hostent *gethostbyaddr(const void *, socklen_t, int) {
+	__ensure(!"gethostbyaddr() not implemented");
+	__builtin_unreachable();
+}
+
+int gethostbyaddr_r(const void *__restrict, socklen_t, int, struct hostent *__restrict,
+					char *__restrict, size_t, struct hostent **__restrict, int *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int gethostbyname_r(const char *__restrict, struct hostent *__restrict, char *__restrict, size_t,
+					struct hostent **__restrict, int *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotobyname(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotobynumber(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotoent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct servent *getservbyname(const char *name, const char *proto) {
+	int iproto = -1;
+	if (proto &&(!strncmp(proto, "tcp", 3) || !strncmp(proto, "TCP", 3)))
+		iproto = IPPROTO_TCP;
+	else if (proto && (!strncmp(proto, "udp", 3) || !strncmp(proto, "UDP", 3)))
+		iproto = IPPROTO_UDP;
+
+	static struct servent ret;
+	if (ret.s_name) {
+		free(ret.s_name);
+		ret.s_name = nullptr;
+
+		for (char **alias = ret.s_aliases; *alias != NULL; alias++) {
+			free(*alias);
+			*alias = nullptr;
+		}
+
+		free(ret.s_proto);
+		ret.s_proto = nullptr;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int count = mlibc::lookup_serv_by_name(serv_buf, name, iproto,
+			0, 0);
+	if (count <= 0)
+		return NULL;
+
+	ret.s_name = serv_buf[0].name.data();
+	serv_buf[0].name.detach();
+	// Sanity check.
+	if (strncmp(name, serv_buf[0].name.data(), serv_buf[0].name.size()))
+		return NULL;
+
+	ret.s_aliases = reinterpret_cast<char**>(malloc((serv_buf[0].aliases.size() + 1) * sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : serv_buf[0].aliases) {
+		ret.s_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	ret.s_aliases[alias_pos] = NULL;
+
+	ret.s_port = htons(serv_buf[0].port);
+
+	auto proto_string = frg::string<MemoryAllocator>(getAllocator());
+	if (!proto) {
+		if (serv_buf[0].protocol == IPPROTO_TCP)
+			proto_string = frg::string<MemoryAllocator>("tcp", getAllocator());
+		else if (serv_buf[0].protocol == IPPROTO_UDP)
+			proto_string = frg::string<MemoryAllocator>("udp", getAllocator());
+		else
+			return NULL;
+	} else {
+		proto_string = frg::string<MemoryAllocator>(proto, getAllocator());
+	}
+	ret.s_proto = proto_string.data();
+	proto_string.detach();
+
+	return &ret;
+}
+
+struct servent *getservbyport(int port, const char *proto) {
+	int iproto = -1;
+	if (proto && (!strncmp(proto, "tcp", 3) || !strncmp(proto, "TCP", 3)))
+		iproto = IPPROTO_TCP;
+	else if (proto && (!strncmp(proto, "udp", 3) || !strncmp(proto, "UDP", 3)))
+		iproto = IPPROTO_UDP;
+
+	static struct servent ret;
+	if (ret.s_name) {
+		free(ret.s_name);
+		ret.s_name = nullptr;
+
+		for (char **alias = ret.s_aliases; *alias != NULL; alias++) {
+			free(*alias);
+			*alias = nullptr;
+		}
+
+		free(ret.s_proto);
+		ret.s_proto = nullptr;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int count = mlibc::lookup_serv_by_port(serv_buf, iproto, ntohs(port));
+	if (count <= 0)
+		return NULL;
+
+	ret.s_name = serv_buf[0].name.data();
+	serv_buf[0].name.detach();
+
+	ret.s_aliases = reinterpret_cast<char**>(malloc((serv_buf[0].aliases.size() + 1) * sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : serv_buf[0].aliases) {
+		ret.s_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	ret.s_aliases[alias_pos] = NULL;
+
+	ret.s_port = port;
+
+	auto proto_string = frg::string<MemoryAllocator>(getAllocator());
+	if (!proto) {
+		if (serv_buf[0].protocol == IPPROTO_TCP)
+			proto_string = frg::string<MemoryAllocator>("tcp", getAllocator());
+		else if (serv_buf[0].protocol == IPPROTO_UDP)
+			proto_string = frg::string<MemoryAllocator>("udp", getAllocator());
+		else
+			return NULL;
+	} else {
+		proto_string = frg::string<MemoryAllocator>(proto, getAllocator());
+	}
+	ret.s_proto = proto_string.data();
+	proto_string.detach();
+
+	return &ret;
+}
+
+struct servent *getservent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void sethostent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setnetent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setprotoent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setservent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+const char *hstrerror(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/poll.cpp b/lib/mlibc/options/posix/generic/poll.cpp
new file mode 100644
index 0000000..c34e25e
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/poll.cpp
@@ -0,0 +1,31 @@
+
+#include <errno.h>
+#include <poll.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int poll(struct pollfd *fds, nfds_t count, int timeout) {
+	int num_events;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_poll, -1);
+	if(int e = mlibc::sys_poll(fds, count, timeout, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
+
+#if __MLIBC_LINUX_OPTION
+int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout_ts, const sigset_t *sigmask) {
+	sigset_t origmask;
+	int timeout = (timeout_ts == NULL) ? -1 : (timeout_ts->tv_sec * 1000 + timeout_ts->tv_nsec / 1000000);
+
+	sigprocmask(SIG_SETMASK, sigmask, &origmask);
+	int ready = poll(fds, nfds, timeout);
+	sigprocmask(SIG_SETMASK, &origmask, NULL);
+
+	return ready;
+}
+#endif // __MLIBC_LINUX_OPTION
+
diff --git a/lib/mlibc/options/posix/generic/posix-file-io.cpp b/lib/mlibc/options/posix/generic/posix-file-io.cpp
new file mode 100644
index 0000000..1a4f38b
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix-file-io.cpp
@@ -0,0 +1,275 @@
+#include <mlibc/posix-file-io.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+#include <errno.h>
+
+namespace mlibc {
+
+int mem_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a mem_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int mem_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int mem_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+memstream_mem_file::memstream_mem_file(char **ptr, size_t *sizeloc, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _bufloc{ptr}, _sizeloc{sizeloc} { }
+
+
+int memstream_mem_file::close() {
+	_update_ptrs();
+	_buf.detach();
+
+	return 0;
+}
+
+int memstream_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int memstream_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if (_pos + max_size >= _buffer_size()) {
+		_buf.resize(_pos + max_size + 1, '\0');
+		_update_ptrs();
+	}
+
+	size_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += max_size;
+	*actual_size = max_size;
+
+	return 0;
+}
+
+int memstream_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			_pos = offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			_pos += offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			_pos = _buffer_size() ? _buffer_size() - 1 + offset : _buffer_size() + offset;
+			_buf.resize(_pos + 1, '\0');
+			_update_ptrs();
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+void memstream_mem_file::_update_ptrs() {
+	*_bufloc = _buf.data();
+	*_sizeloc = _buf.size() - 1;
+}
+
+fmemopen_mem_file::fmemopen_mem_file(void *in_buf, size_t size, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _inBuffer{in_buf}, _inBufferSize{size} {
+	if(!_inBuffer) {
+		_inBuffer = getAllocator().allocate(size);
+		_needsDeallocation = true;
+	}
+
+	if(_flags & O_APPEND) {
+		// the initial seek-size for append is zero if buf was NULL, or the first '\0' found, or the size
+		_max_size = (_needsDeallocation) ? 0 : strnlen(reinterpret_cast<char *>(_inBuffer), _inBufferSize);
+		_pos = _max_size;
+	} else if((_flags & O_WRONLY || _flags & O_RDWR) && _flags & O_CREAT && _flags & O_TRUNC) {
+		// modes: "w", "w+"
+		_max_size = 0;
+	} else {
+		_max_size = size;
+	}
+}
+
+int fmemopen_mem_file::close() {
+	if(_needsDeallocation) {
+		getAllocator().free(_inBuffer);
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int fmemopen_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	off_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += bytes_write;
+	*actual_size = bytes_write;
+
+	if(_pos > _max_size) {
+		_max_size = _pos;
+	}
+
+	// upon flushing, we need to put a null byte at the current position or at the end of the buffer
+	size_t null = _pos;
+	// a special case is if the mode is set to updating ('+'), then it always goes at the end
+	if(null >= _buffer_size() || _flags & O_RDWR) {
+		null = _buffer_size() - 1;
+	}
+
+	if(_buffer_size()) {
+		_buffer()[null] = '\0';
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			if(offset < 0 || size_t(offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			// seeking to negative positions or positions larger than the buffer is disallowed in fmemopen(3)
+			if((_pos + offset) < 0 || size_t(_pos + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos += offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			if((_max_size + offset) < 0 || size_t(_max_size + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = _max_size + offset;
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+int cookie_file::close() {
+	if(!_funcs.close) {
+		return 0;
+	}
+
+	return _funcs.close(_cookie);
+}
+
+int cookie_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a cookie_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int cookie_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int cookie_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+int cookie_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.read) {
+		return EOF;
+	}
+
+	*actual_size = _funcs.read(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.write) {
+		return 0;
+	}
+
+	*actual_size = _funcs.write(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	if(!_funcs.seek) {
+		return ENOTSUP;
+	}
+
+	*new_offset = offset;
+
+	return _funcs.seek(_cookie, new_offset, whence);
+}
+
+} // namespace mlibc
+
+FILE *fdopen(int fd, const char *mode) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	flags &= ~O_TRUNC; // 'w' should not truncate the file
+
+	if (flags & O_APPEND) {
+		int cur_flags = fcntl(fd, F_GETFL, 0);
+		if (cur_flags < 0) {
+			errno = EINVAL;
+			return nullptr;
+		} else if (!(cur_flags & O_APPEND)) {
+			if (fcntl(fd, F_SETFL, cur_flags | O_APPEND)) {
+				errno = EINVAL;
+				return nullptr;
+			}
+		}
+	}
+
+	if (flags & O_CLOEXEC) {
+		if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
+			errno = EINVAL;
+			return nullptr;
+		}
+	}
+
+	// TODO: We may need to activate line buffered mode for terminals.
+
+	return frg::construct<mlibc::fd_file>(getAllocator(), fd,
+			mlibc::file_dispose_cb<mlibc::fd_file>);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_ctype.cpp b/lib/mlibc/options/posix/generic/posix_ctype.cpp
new file mode 100644
index 0000000..19f129f
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_ctype.cpp
@@ -0,0 +1,136 @@
+#include <ctype.h>
+#include <wctype.h>
+
+#include <bits/ensure.h>
+
+int isalnum_l(int c, locale_t) {
+    return isalnum(c);
+}
+
+int isalpha_l(int c, locale_t) {
+    return isalpha(c);
+}
+
+int isblank_l(int c, locale_t) {
+    return isblank(c);
+}
+
+int iscntrl_l(int c, locale_t) {
+    return iscntrl(c);
+}
+
+int isdigit_l(int c, locale_t) {
+    return isdigit(c);
+}
+
+int isgraph_l(int c, locale_t) {
+    return isgraph(c);
+}
+
+int islower_l(int c, locale_t) {
+    return islower(c);
+}
+
+int isprint_l(int c, locale_t) {
+    return isprint(c);
+}
+
+int ispunct_l(int c, locale_t) {
+    return ispunct(c);
+}
+
+int isspace_l(int c, locale_t) {
+    return isspace(c);
+}
+
+int isupper_l(int c, locale_t) {
+    return isupper(c);
+}
+
+int isxdigit_l(int c, locale_t) {
+    return isxdigit(c);
+}
+
+int isascii_l(int c, locale_t) {
+    return isascii(c);
+}
+
+int tolower_l(int c, locale_t) {
+    return tolower(c);
+}
+
+int toupper_l(int c, locale_t) {
+    return toupper(c);
+}
+
+int iswalnum_l(wint_t c, locale_t) {
+    return iswalnum(c);
+}
+
+int iswblank_l(wint_t c, locale_t) {
+    return iswblank(c);
+}
+
+int iswcntrl_l(wint_t c, locale_t) {
+    return iswcntrl(c);
+}
+
+int iswdigit_l(wint_t c, locale_t) {
+    return iswdigit(c);
+}
+
+int iswgraph_l(wint_t c, locale_t) {
+    return iswgraph(c);
+}
+
+int iswlower_l(wint_t c, locale_t) {
+    return iswlower(c);
+}
+
+int iswprint_l(wint_t c, locale_t) {
+    return iswprint(c);
+}
+
+int iswpunct_l(wint_t c, locale_t) {
+    return iswpunct(c);
+}
+
+int iswspace_l(wint_t c, locale_t) {
+    return iswspace(c);
+}
+
+int iswupper_l(wint_t c, locale_t) {
+    return iswupper(c);
+}
+
+int iswxdigit_l(wint_t c, locale_t) {
+    return iswxdigit(c);
+}
+
+int iswalpha_l(wint_t c, locale_t) {
+    return iswalpha(c);
+}
+
+wctype_t wctype_l(const char* p, locale_t) {
+    return wctype(p);
+}
+
+int iswctype_l(wint_t w, wctype_t t, locale_t) {
+    return iswctype(w, t);
+}
+
+wint_t towlower_l(wint_t c, locale_t) {
+    return towlower(c);
+}
+
+wint_t towupper_l(wint_t c, locale_t) {
+    return towupper(c);
+}
+
+wctrans_t wctrans_l(const char* c, locale_t) {
+    return wctrans(c);
+}
+
+wint_t towctrans_l(wint_t c, wctrans_t desc, locale_t) {
+    return towctrans(c, desc);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_locale.cpp b/lib/mlibc/options/posix/generic/posix_locale.cpp
new file mode 100644
index 0000000..bd8710a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_locale.cpp
@@ -0,0 +1,37 @@
+#include <bits/posix/posix_locale.h>
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+namespace {
+
+bool newlocale_seen = false;
+bool uselocale_seen = false;
+
+}
+
+locale_t newlocale(int, const char *, locale_t) {
+	// Due to all of the locale functions being stubs, the locale will not be used
+	if(!newlocale_seen) {
+		mlibc::infoLogger() << "mlibc: newlocale() is a no-op" << frg::endlog;
+		newlocale_seen = true;
+	}
+	return nullptr;
+}
+
+void freelocale(locale_t) {
+	mlibc::infoLogger() << "mlibc: freelocale() is a no-op" << frg::endlog;
+	return;
+}
+
+locale_t uselocale(locale_t) {
+	if(!uselocale_seen) {
+		mlibc::infoLogger() << "mlibc: uselocale() is a no-op" << frg::endlog;
+		uselocale_seen = true;
+	}
+	return nullptr;
+}
+
+locale_t duplocale(locale_t) {
+	mlibc::infoLogger() << "mlibc: duplocale() is a no-op" << frg::endlog;
+	return nullptr;
+}
diff --git a/lib/mlibc/options/posix/generic/posix_signal.cpp b/lib/mlibc/options/posix/generic/posix_signal.cpp
new file mode 100644
index 0000000..eef3ef3
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_signal.cpp
@@ -0,0 +1,151 @@
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+#include <bits/ensure.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/tcb.hpp>
+
+int sigsuspend(const sigset_t *sigmask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigsuspend, -1);
+
+	// This is guaranteed to return an error (EINTR most probably)
+	errno = mlibc::sys_sigsuspend(sigmask);
+	return -1;
+}
+
+int pthread_sigmask(int how, const sigset_t *__restrict set, sigset_t *__restrict retrieve) {
+	if(!mlibc::sys_sigprocmask) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+	if(int e = mlibc::sys_sigprocmask(how, set, retrieve); e) {
+		return e;
+	}
+	return 0;
+}
+
+int pthread_kill(pthread_t thread, int sig) {
+	auto tcb = reinterpret_cast<Tcb *>(thread);
+	auto pid = getpid();
+
+	if(!mlibc::sys_tgkill) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	if(int e = mlibc::sys_tgkill(pid, tcb->tid, sig); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int sigaction(int signum, const struct sigaction *__restrict act, struct sigaction *__restrict oldact) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigaction, -1);
+	if(int e = mlibc::sys_sigaction(signum, act, oldact); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int siginterrupt(int sig, int flag) {
+	int ret;
+	struct sigaction act;
+
+	sigaction(sig, NULL, &act);
+	if (flag)
+		act.sa_flags &= ~SA_RESTART;
+	else
+		act.sa_flags |= SA_RESTART;
+
+	ret = sigaction(sig, &act, NULL);
+	return ret;
+}
+
+int kill(pid_t pid, int number) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_kill, -1);
+	if(int e = mlibc::sys_kill(pid, number); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int killpg(pid_t pgrp, int sig) {
+	if(pgrp > 1) {
+		return kill(-pgrp, sig);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+int sigtimedwait(const sigset_t *__restrict set, siginfo_t *__restrict info, const struct timespec *__restrict timeout) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigtimedwait, -1);
+
+	int signo;
+
+	if (int e = sysdep(set, info, timeout, &signo)) {
+		errno = e;
+		return -1;
+	}
+
+	return signo;
+}
+
+int sigwaitinfo(const sigset_t *__restrict set, siginfo_t *__restrict info) {
+	// NOTE: This assumes the sysdep behavior noted in mlibc/posix-sysdeps.hpp
+	return sigtimedwait(set, info, nullptr);
+}
+
+int sigwait(const sigset_t *__restrict set, int *__restrict sig) {
+	if (int e = sigwaitinfo(set, nullptr); e < 0) {
+		return e;
+	} else {
+		if (sig)
+			*sig = e;
+
+		return 0;
+	}
+}
+
+int sigpending(sigset_t *set) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigpending, -1);
+
+	if(int e = sysdep(set)) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int sigaltstack(const stack_t *__restrict ss, stack_t *__restrict oss) {
+	if (ss && ss->ss_size < MINSIGSTKSZ && !(ss->ss_flags & SS_DISABLE)) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigaltstack, -1);
+	if (int e = mlibc::sys_sigaltstack(ss, oss); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+#if __MLIBC_GLIBC_OPTION
+int sigisemptyset(const sigset_t *set) {
+	return !(*set);
+}
+#endif // __MLIBC_GLIBC_OPTION
+
+int sigqueue(pid_t, int, const union sigval) {
+	__ensure(!"sigqueue() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/posix_stdio.cpp b/lib/mlibc/options/posix/generic/posix_stdio.cpp
new file mode 100644
index 0000000..fc77a54
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_stdio.cpp
@@ -0,0 +1,209 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/file-io.hpp>
+#include <mlibc/posix-file-io.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+struct popen_file : mlibc::fd_file {
+	popen_file(int fd, void (*do_dispose)(abstract_file *) = nullptr)
+		: fd_file(fd, do_dispose) {}
+
+	pid_t get_popen_pid() {
+		return _popen_pid;
+	}
+
+	void set_popen_pid(pid_t new_pid) {
+		_popen_pid = new_pid;
+	}
+
+private:
+	// Underlying PID in case of popen()
+	pid_t _popen_pid;
+};
+
+FILE *fmemopen(void *buf, size_t size, const char *__restrict mode) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	return frg::construct<mlibc::fmemopen_mem_file>(getAllocator(), buf, size, flags,
+		mlibc::file_dispose_cb<mlibc::mem_file>);
+}
+
+int pclose(FILE *stream) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+
+	auto file = static_cast<popen_file *>(stream);
+
+	int status;
+	pid_t pid = file->get_popen_pid();
+
+	fclose(file);
+
+	if (mlibc::sys_waitpid(pid, &status, 0, NULL, &pid) != 0) {
+	    errno = ECHILD;
+	    return -1;
+	}
+
+	return status;
+}
+
+FILE *popen(const char *command, const char *typestr) {
+	bool is_write;
+	pid_t child;
+	FILE *ret = nullptr;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fork && mlibc::sys_dup2 && mlibc::sys_execve &&
+			mlibc::sys_sigprocmask && mlibc::sys_sigaction && mlibc::sys_pipe, nullptr);
+
+	if (typestr == NULL) {
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	if (strstr(typestr, "w") != NULL) {
+		is_write = true;
+	} else if (strstr(typestr, "r") != NULL) {
+		is_write = false;
+	} else {
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	bool cloexec = false;
+	if (strstr(typestr, "e") != NULL) {
+		// Set FD_CLOEXEC on the new file descriptor
+		cloexec = true;
+	}
+
+	int fds[2];
+	if (int e = mlibc::sys_pipe(fds, 0)) {
+		errno = e;
+		return nullptr;
+	}
+
+	struct sigaction new_sa, old_int, old_quit;
+	sigset_t new_mask, old_mask;
+
+	new_sa.sa_handler = SIG_IGN;
+	new_sa.sa_flags = 0;
+	sigemptyset(&new_sa.sa_mask);
+	mlibc::sys_sigaction(SIGINT, &new_sa, &old_int);
+	mlibc::sys_sigaction(SIGQUIT, &new_sa, &old_quit);
+
+	sigemptyset(&new_mask);
+	sigaddset(&new_mask, SIGCHLD);
+	mlibc::sys_sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
+
+	int parent_end = is_write ? 1 : 0;
+	int child_end = is_write ? 0 : 1;
+
+	if (int e = mlibc::sys_fork(&child)) {
+		errno = e;
+		mlibc::sys_close(fds[0]);
+		mlibc::sys_close(fds[1]);
+	} else if (!child) {
+		// For the child
+		mlibc::sys_sigaction(SIGINT, &old_int, nullptr);
+		mlibc::sys_sigaction(SIGQUIT, &old_quit, nullptr);
+		mlibc::sys_sigprocmask(SIG_SETMASK, &old_mask, nullptr);
+
+		mlibc::sys_close(fds[parent_end]);
+
+		if (mlibc::sys_dup2(fds[child_end], 0, is_write ? 0 : 1)) {
+			__ensure(!"sys_dup2() failed in popen()");
+		}
+		mlibc::sys_close(fds[child_end]);
+
+		const char *args[] = {
+			"sh", "-c", command, nullptr
+		};
+
+		mlibc::sys_execve("/bin/sh", const_cast<char **>(args), environ);
+		_Exit(127);
+	} else {
+		// For the parent
+		mlibc::sys_close(fds[child_end]);
+
+		ret = frg::construct<popen_file>(
+			getAllocator(),
+			fds[parent_end],
+			mlibc::file_dispose_cb<popen_file>
+		);
+		__ensure(ret);
+
+		auto file = static_cast<popen_file *>(ret);
+
+		file->set_popen_pid(child);
+
+		if (cloexec == true) {
+			fcntl(file->fd(), F_SETFD, O_CLOEXEC);
+		}
+	}
+
+	mlibc::sys_sigaction(SIGINT, &old_int, nullptr);
+	mlibc::sys_sigaction(SIGQUIT, &old_quit, nullptr);
+	mlibc::sys_sigprocmask(SIG_SETMASK, &old_mask, nullptr);
+
+	return ret;
+}
+
+FILE *open_memstream(char **buf, size_t *sizeloc) {
+	return frg::construct<mlibc::memstream_mem_file>(getAllocator(), buf, sizeloc, O_RDWR,
+			mlibc::file_dispose_cb<mlibc::mem_file>);
+}
+
+int fseeko(FILE *file_base, off_t offset, int whence) {
+	auto file = static_cast<mlibc::abstract_file *>(file_base);
+	if(int e = file->seek(offset, whence); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+off_t ftello(FILE *file_base) {
+	auto file = static_cast<mlibc::abstract_file *>(file_base);
+	off_t current_offset;
+	if(int e = file->tell(&current_offset); e) {
+		errno = e;
+		return -1;
+	}
+	return current_offset;
+}
+
+int dprintf(int fd, const char *format, ...) {
+	va_list args;
+	va_start(args, format);
+	int result = vdprintf(fd, format, args);
+	va_end(args);
+	return result;
+}
+
+int vdprintf(int fd, const char *format, __builtin_va_list args) {
+	mlibc::fd_file file{fd};
+	int ret = vfprintf(&file, format, args);
+	file.flush();
+	return ret;
+}
+
+char *fgetln(FILE *, size_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+FILE *fopencookie(void *cookie, const char *__restrict mode, cookie_io_functions_t funcs) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	return frg::construct<mlibc::cookie_file>(getAllocator(), cookie, flags, funcs,
+		mlibc::file_dispose_cb<mlibc::cookie_file>);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_stdlib.cpp b/lib/mlibc/options/posix/generic/posix_stdlib.cpp
new file mode 100644
index 0000000..4010998
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_stdlib.cpp
@@ -0,0 +1,513 @@
+
+#include <abi-bits/fcntl.h>
+#include <bits/ensure.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+
+#include <frg/small_vector.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/rtdl-config.hpp>
+
+namespace {
+	constexpr bool debugPathResolution = false;
+}
+
+// Borrowed from musl
+static uint32_t init[] = {
+0x00000000,0x5851f42d,0xc0b18ccf,0xcbb5f646,
+0xc7033129,0x30705b04,0x20fd5db4,0x9a8b7f78,
+0x502959d8,0xab894868,0x6c0356a7,0x88cdb7ff,
+0xb477d43f,0x70a3a52b,0xa8e4baf1,0xfd8341fc,
+0x8ae16fd9,0x742d2f7a,0x0d1f0796,0x76035e09,
+0x40f7702c,0x6fa72ca5,0xaaa84157,0x58a0df74,
+0xc74a0364,0xae533cc4,0x04185faf,0x6de3b115,
+0x0cab8628,0xf043bfa4,0x398150e9,0x37521657};
+
+static int n = 31;
+static int i = 3;
+static int j = 0;
+static uint32_t *x = init + 1;
+
+
+static uint32_t lcg31(uint32_t x) {
+	return (1103515245 * x + 12345) & 0x7fffffff;
+}
+
+static uint64_t lcg64(uint64_t x) {
+	return 6364136223846793005ull * x + 1;
+}
+
+static void *savestate(void) {
+	x[-1] = (n << 16) | (i << 8) | j;
+	return x - 1;
+}
+
+static void loadstate(uint32_t *state) {
+	x = state + 1;
+	n = x[-1] >> 16;
+	i = (x[-1] >> 8) & 0xff;
+	j = x[-1] & 0xff;
+}
+
+long random(void) {
+	long k;
+
+	if(n == 0) {
+		k = x[0] = lcg31(x[0]);
+		return k;
+	}
+	x[i] += x[j];
+	k = x[i] >> 1;
+	if(++i == n)
+		i = 0;
+	if(++j == n)
+		j = 0;
+
+	return k;
+}
+
+double drand48(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void srand48(long int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// Borrowed from musl
+void srandom(unsigned int seed) {
+	int k;
+	uint64_t s = seed;
+
+	if(n == 0) {
+		x[0] = s;
+		return;
+	}
+	i = n == 31 || n == 7 ? 3 : 1;
+	j = 0;
+	for(k = 0; k < n; k++) {
+		s = lcg64(s);
+		x[k] = s >> 32;
+	}
+	// Make sure x contains at least one odd number
+	x[0] |= 1;
+}
+
+char *initstate(unsigned int seed, char *state, size_t size) {
+	void *old;
+
+	if(size < 8)
+		return 0;
+	old = savestate();
+	if(size < 32)
+		n = 0;
+	else if(size < 64)
+		n = 7;
+	else if(size < 128)
+		n = 15;
+	else if(size < 256)
+		n = 31;
+	else
+		n = 63;
+	x = (uint32_t *)state + 1;
+	srandom(seed);
+	savestate();
+	return (char *)old;
+}
+
+char *setstate(char *state) {
+	void *old;
+
+	old = savestate();
+	loadstate((uint32_t *)state);
+	return (char *)old;
+}
+
+// ----------------------------------------------------------------------------
+// Path handling.
+// ----------------------------------------------------------------------------
+
+
+int mkostemps(char *pattern, int suffixlen, int flags) {
+	auto n = strlen(pattern);
+	if(n < (6 + static_cast<size_t>(suffixlen))) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	flags &= ~O_WRONLY;
+
+	for(size_t i = 0; i < 6; i++) {
+		if(pattern[n - (6 + suffixlen) + i] == 'X')
+			continue;
+		errno = EINVAL;
+		return -1;
+	}
+
+	// TODO: Do an exponential search.
+	for(size_t i = 0; i < 999999; i++) {
+		char sfx = pattern[n - suffixlen];
+		__ensure(sprintf(pattern + (n - (6 + suffixlen)), "%06zu", i) == 6);
+		pattern[n - suffixlen] = sfx;
+
+		int fd;
+		if(int e = mlibc::sys_open(pattern, O_RDWR | O_CREAT | O_EXCL | flags, S_IRUSR | S_IWUSR, &fd); !e) {
+			return fd;
+		}else if(e != EEXIST) {
+			errno = e;
+			return -1;
+		}
+	}
+
+	errno = EEXIST;
+	return -1;
+}
+
+int mkostemp(char *pattern, int flags) {
+	return mkostemps(pattern, flags, 0);
+}
+
+int mkstemp(char *path) {
+	return mkostemp(path, 0);
+}
+
+int mkstemps(char *pattern, int suffixlen) {
+	return mkostemps(pattern, suffixlen, 0);
+}
+
+char *mkdtemp(char *pattern) {
+	mlibc::infoLogger() << "mlibc mkdtemp(" << pattern << ") called" << frg::endlog;
+	auto n = strlen(pattern);
+	__ensure(n >= 6);
+	if(n < 6) {
+		errno = EINVAL;
+		return NULL;
+	}
+	for(size_t i = 0; i < 6; i++) {
+		if(pattern[n - 6 + i] == 'X')
+			continue;
+		errno = EINVAL;
+		return NULL;
+	}
+
+	// TODO: Do an exponential search.
+	for(size_t i = 0; i < 999999; i++) {
+		__ensure(sprintf(pattern + (n - 6), "%06zu", i) == 6);
+		if(int e = mlibc::sys_mkdir(pattern, S_IRWXU); !e) {
+			return pattern;
+		}else if(e != EEXIST) {
+			errno = e;
+			return NULL;
+		}
+	}
+
+	errno = EEXIST;
+	return NULL;
+}
+
+char *realpath(const char *path, char *out) {
+	if(debugPathResolution)
+		mlibc::infoLogger() << "mlibc realpath(): Called on '" << path << "'" << frg::endlog;
+	frg::string_view path_view{path};
+
+	// In case of the root, the string only contains the null-terminator.
+	frg::small_vector<char, PATH_MAX, MemoryAllocator> resolv{getAllocator()};
+	size_t ps;
+
+	// If the path is relative, we have to preprend the working directory.
+	if(path[0] == '/') {
+		resolv.push_back(0);
+		ps = 1;
+	}else{
+		MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getcwd, nullptr);
+
+		// Try to getcwd() until the buffer is large enough.
+		resolv.resize(128);
+		while(true) {
+			int e = mlibc::sys_getcwd(resolv.data(), resolv.size());
+			if(e == ERANGE) {
+				resolv.resize(2 * resolv.size());
+			}else if(!e) {
+				break;
+			}else{
+				errno = e;
+				return nullptr;
+			}
+		}
+		frg::string_view cwd_view{resolv.data()};
+		if(cwd_view == "/") {
+			// Restore our invariant that we only store the null-terminator for the root.
+			resolv.resize(1);
+			resolv[0] = 0;
+		}else{
+			resolv.resize(cwd_view.size() + 1);
+		}
+		ps = 0;
+	}
+
+	// Contains unresolved links as a relative path compared to resolv.
+	frg::small_vector<char, PATH_MAX, MemoryAllocator> lnk{getAllocator()};
+	size_t ls = 0;
+
+	auto process_segment = [&] (frg::string_view s_view) -> int {
+		if(debugPathResolution)
+			mlibc::infoLogger() << "mlibc realpath(): resolv is '" << resolv.data() << "'"
+					<< ", segment is " << s_view.data()
+					<< ", size: " << s_view.size() << frg::endlog;
+
+		if(!s_view.size() || s_view == ".") {
+			// Keep resolv invariant.
+			return 0;
+		}else if(s_view == "..") {
+			// Remove a single segment from resolv.
+			if(resolv.size() > 1) {
+				auto slash = strrchr(resolv.data(), '/');
+				__ensure(slash); // We never remove the leading sla.
+				resolv.resize((slash - resolv.data()) + 1);
+				*slash = 0; // Replace the slash by a null-terminator.
+			}
+			return 0;
+		}
+
+		// Append the segment to resolv.
+		auto rsz = resolv.size();
+		resolv[rsz - 1] = '/'; // Replace null-terminator by a slash.
+		resolv.resize(rsz + s_view.size() + 1);
+		memcpy(resolv.data() + rsz, s_view.data(), s_view.size());
+		resolv[rsz + s_view.size()] = 0;
+
+		// stat() the path to (1) see if it exists and (2) see if it is a link.
+		if(!mlibc::sys_stat) {
+			MLIBC_MISSING_SYSDEP();
+			return ENOSYS;
+		}
+		if(debugPathResolution)
+			mlibc::infoLogger() << "mlibc realpath(): stat()ing '"
+					<< resolv.data() << "'" << frg::endlog;
+		struct stat st;
+		if(int e = mlibc::sys_stat(mlibc::fsfd_target::path,
+				-1, resolv.data(), AT_SYMLINK_NOFOLLOW, &st); e)
+			return e;
+
+		if(S_ISLNK(st.st_mode)) {
+			if(debugPathResolution) {
+				mlibc::infoLogger() << "mlibc realpath(): Encountered symlink '"
+					<< resolv.data() << "'" << frg::endlog;
+			}
+
+			if(!mlibc::sys_readlink) {
+				MLIBC_MISSING_SYSDEP();
+				return ENOSYS;
+			}
+
+			ssize_t sz = 0;
+			char path[512];
+
+			if (int e = mlibc::sys_readlink(resolv.data(), path, 512, &sz); e)
+				return e;
+
+			if(debugPathResolution) {
+				mlibc::infoLogger() << "mlibc realpath(): Symlink resolves to '"
+					<< frg::string_view{path, static_cast<size_t>(sz)} << "'" << frg::endlog;
+			}
+
+			if (path[0] == '/') {
+				// Absolute path, replace resolv
+				resolv.resize(sz);
+				strncpy(resolv.data(), path, sz - 1);
+				resolv.data()[sz - 1] = 0;
+
+				if(debugPathResolution) {
+					mlibc::infoLogger() << "mlibc realpath(): Symlink is absolute, resolv: '"
+						<< resolv.data() << "'" << frg::endlog;
+				}
+			} else {
+				// Relative path, revert changes to resolv, prepend to lnk
+				resolv.resize(rsz);
+				resolv[rsz - 1] = 0;
+
+				auto lsz = lnk.size();
+				lnk.resize((lsz - ls) + sz + 1);
+				memmove(lnk.data() + sz, lnk.data() + ls, lsz - ls);
+				memcpy(lnk.data(), path, sz);
+				lnk[(lsz - ls) + sz] = 0;
+
+				ls = 0;
+
+				if(debugPathResolution) {
+					mlibc::infoLogger() << "mlibc realpath(): Symlink is relative, resolv: '"
+						<< resolv.data() << "' lnk: '"
+						<< frg::string_view{lnk.data(), lnk.size()} << "'" << frg::endlog;
+				}
+			}
+		}
+
+		return 0;
+	};
+
+	// Each iteration of this outer loop consumes segment of the input path.
+	// This design avoids copying the input path into lnk;
+	// the latter could often involve additional allocations.
+	while(ps < path_view.size()) {
+		frg::string_view ps_view;
+		if(auto slash = strchr(path + ps, '/'); slash) {
+			ps_view = frg::string_view{path + ps, static_cast<size_t>(slash - (path + ps))};
+		}else{
+			ps_view = frg::string_view{path + ps, strlen(path) - ps};
+		}
+		ps += ps_view.size() + 1;
+
+		// Handle one segment from the input path.
+		if(int e = process_segment(ps_view); e) {
+			errno = e;
+			return nullptr;
+		}
+
+		// This inner loop consumes segments of lnk.
+		while(ls < lnk.size()) {
+			frg::string_view ls_view;
+			if(auto slash = strchr(lnk.data() + ls, '/'); slash) {
+				ls_view = frg::string_view{lnk.data() + ls, static_cast<size_t>(slash - (lnk.data() + ls))};
+			}else{
+				ls_view = frg::string_view{lnk.data() + ls, strlen(lnk.data()) - ls};
+			}
+			ls += ls_view.size() + 1;
+
+			// Handle one segment from the link
+			if(int e = process_segment(ls_view); e) {
+				errno = e;
+				return nullptr;
+			}
+		}
+
+		// All of lnk was consumed, reset it
+		lnk.resize(0);
+		ls = 0;
+	}
+
+	if(resolv.size() == 1) {
+		resolv.resize(0);
+		resolv.push_back('/');
+		resolv.push_back(0);
+	}
+
+	if(debugPathResolution)
+		mlibc::infoLogger() << "mlibc realpath(): Returns '" << resolv.data() << "'" << frg::endlog;
+
+	if(resolv.size() > PATH_MAX) {
+		errno = ENAMETOOLONG;
+		return nullptr;
+	}
+
+	if(!out)
+		out = reinterpret_cast<char *>(getAllocator().allocate(resolv.size()));
+	strcpy(out, resolv.data());
+	return out;
+}
+
+// ----------------------------------------------------------------------------
+// Pseudoterminals
+// ----------------------------------------------------------------------------
+
+int ptsname_r(int fd, char *buffer, size_t length) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ptsname, ENOSYS);
+
+	if(int e = sysdep(fd, buffer, length); e)
+		return e;
+
+	return 0;
+}
+
+char *ptsname(int fd) {
+	static char buffer[128];
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ptsname, NULL);
+
+	if(int e = sysdep(fd, buffer, 128); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return buffer;
+}
+
+int posix_openpt(int flags) {
+	int fd;
+	if(int e = mlibc::sys_open("/dev/ptmx", flags, 0, &fd); e) {
+		errno = e;
+		return -1;
+	}
+
+	return fd;
+}
+
+int unlockpt(int fd) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlockpt, -1);
+
+	if(int e = sysdep(fd); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int grantpt(int) {
+	return 0;
+}
+
+double strtod_l(const char *__restrict__ nptr, char ** __restrict__ endptr, locale_t) {
+	mlibc::infoLogger() << "mlibc: strtod_l ignores locale!" << frg::endlog;
+	return strtod(nptr, endptr);
+}
+
+long double strtold_l(const char *__restrict__, char ** __restrict__, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+float strtof_l(const char *__restrict__ nptr, char **__restrict__ endptr, locale_t) {
+	mlibc::infoLogger() << "mlibc: strtof_l ignores locales" << frg::endlog;
+	return strtof(nptr, endptr);
+}
+
+int strcoll_l(const char *, const char *, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getloadavg(double *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *secure_getenv(const char *name) {
+	if (mlibc::rtdlConfig().secureRequired)
+		return NULL;
+	else
+		return getenv(name);
+}
+
+void *reallocarray(void *ptr, size_t m, size_t n) {
+	if(n && m > -1 / n) {
+		errno = ENOMEM;
+		return 0;
+	}
+
+	return realloc(ptr, m * n);
+}
+
+char *canonicalize_file_name(const char *name) {
+	return realpath(name, NULL);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_string.cpp b/lib/mlibc/options/posix/generic/posix_string.cpp
new file mode 100644
index 0000000..d0bc7b5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_string.cpp
@@ -0,0 +1,174 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <bits/ensure.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <signal.h>
+
+#include <mlibc/debug.hpp>
+
+char *strdup(const char *string) {
+	auto num_bytes = strlen(string);
+
+	char *new_string = (char *)malloc(num_bytes + 1);
+	if(!new_string) // TODO: set errno
+		return nullptr;
+
+	memcpy(new_string, string, num_bytes);
+	new_string[num_bytes] = 0;
+	return new_string;
+}
+
+char *strndup(const char *string, size_t max_size) {
+	auto num_bytes = strnlen(string, max_size);
+	char *new_string = (char *)malloc(num_bytes + 1);
+	if(!new_string) // TODO: set errno
+		return nullptr;
+
+	memcpy(new_string, string, num_bytes);
+	new_string[num_bytes] = 0;
+	return new_string;
+}
+
+char *stpcpy(char *__restrict dest, const char *__restrict src) {
+	auto n = strlen(src);
+	memcpy(dest, src, n + 1);
+	return dest + n;
+}
+
+char *stpncpy(char *__restrict dest, const char *__restrict src, size_t n) {
+	size_t nulls, copied, srcLen = strlen(src);
+	if (n >= srcLen) {
+		nulls = n - srcLen;
+		copied = srcLen;
+	} else {
+		nulls = 0;
+		copied = n;
+	}
+
+	memcpy(dest, src, copied);
+	memset(dest + srcLen, 0, nulls);
+	return dest + n - nulls;
+}
+
+size_t strnlen(const char *s, size_t n) {
+	size_t len = 0;
+	while(len < n && s[len])
+		++len;
+	return len;
+}
+
+char *strsep(char **m, const char *del) {
+	__ensure(m);
+
+	auto tok = *m;
+	if(!tok)
+		return nullptr;
+
+	// Replace the following delimiter by a null-terminator.
+	// After this loop: *p is null iff we reached the end of the string.
+	auto p = tok;
+	while(*p && !strchr(del, *p))
+		p++;
+
+	if(*p) {
+		*p = 0;
+		*m = p + 1;
+	}else{
+		*m = nullptr;
+	}
+	return tok;
+}
+
+char *strsignal(int sig) {
+	#define CASE_FOR(sigconst) case sigconst: s = #sigconst; break;
+	const char *s;
+	switch(sig) {
+	CASE_FOR(SIGABRT)
+	CASE_FOR(SIGFPE)
+	CASE_FOR(SIGILL)
+	CASE_FOR(SIGINT)
+	CASE_FOR(SIGSEGV)
+	CASE_FOR(SIGTERM)
+	CASE_FOR(SIGPROF)
+	CASE_FOR(SIGIO)
+	CASE_FOR(SIGPWR)
+	CASE_FOR(SIGALRM)
+	CASE_FOR(SIGBUS)
+	CASE_FOR(SIGCHLD)
+	CASE_FOR(SIGCONT)
+	CASE_FOR(SIGHUP)
+	CASE_FOR(SIGKILL)
+	CASE_FOR(SIGPIPE)
+	CASE_FOR(SIGQUIT)
+	CASE_FOR(SIGSTOP)
+	CASE_FOR(SIGTSTP)
+	CASE_FOR(SIGTTIN)
+	CASE_FOR(SIGTTOU)
+	CASE_FOR(SIGUSR1)
+	CASE_FOR(SIGUSR2)
+	CASE_FOR(SIGSYS)
+	CASE_FOR(SIGTRAP)
+	CASE_FOR(SIGURG)
+	CASE_FOR(SIGVTALRM)
+	CASE_FOR(SIGXCPU)
+	CASE_FOR(SIGXFSZ)
+	CASE_FOR(SIGWINCH)
+	default:
+		mlibc::infoLogger() << "mlibc: Unknown signal number " << sig << frg::endlog;
+		s = "Unknown signal number";
+	}
+	return const_cast<char *>(s);
+}
+
+char *strcasestr(const char *s, const char *pattern) {
+	size_t plen = strlen(pattern);
+	const char *p = s;
+	while(*p) {
+		// Need strncasecmp() to avoid checking past the end of a successful match.
+		if(!strncasecmp(p, pattern, plen))
+			return const_cast<char *>(p);
+		++p;
+	}
+	return nullptr;
+}
+
+void *memccpy(void *__restrict, const void *__restrict, int, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// This implementation was taken from musl
+void *memrchr(const void *m, int c, size_t n) {
+	const unsigned char *s = (const unsigned char *)m;
+	c = (unsigned char)c;
+	while(n--) {
+		if(s[n] == c)
+			return (void *)(s + n);
+	}
+	return 0;
+}
+
+// BSD extensions.
+// Taken from musl
+size_t strlcpy(char *d, const char *s, size_t n) {
+	char *d0 = d;
+
+	if(!n--)
+		goto finish;
+	for(; n && (*d=*s); n--, s++, d++);
+	*d = 0;
+finish:
+	return d-d0 + strlen(s);
+}
+
+size_t strlcat(char *d, const char *s, size_t n) {
+	size_t l = strnlen(d, n);
+	if(l == n) {
+		return l + strlen(s);
+	}
+	return l + strlcpy(d + l, s, n - l);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_time.cpp b/lib/mlibc/options/posix/generic/posix_time.cpp
new file mode 100644
index 0000000..d93ebbc
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_time.cpp
@@ -0,0 +1,32 @@
+#include <bits/posix/posix_time.h>
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+#include <errno.h>
+
+int utimes(const char *filename, const struct timeval times[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	struct timespec time[2];
+	if(times == nullptr) {
+		time[0].tv_sec = UTIME_NOW;
+		time[0].tv_nsec = UTIME_NOW;
+		time[1].tv_sec = UTIME_NOW;
+		time[1].tv_nsec = UTIME_NOW;
+	} else {
+		time[0].tv_sec = times[0].tv_sec;
+		time[0].tv_nsec = times[0].tv_usec * 1000;
+		time[1].tv_sec = times[1].tv_sec;
+		time[1].tv_nsec = times[1].tv_usec * 1000;
+	}
+
+	if (int e = mlibc::sys_utimensat(AT_FDCWD, filename, time, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int futimes(int, const struct timeval[2]) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/pthread-stubs.cpp b/lib/mlibc/options/posix/generic/pthread-stubs.cpp
new file mode 100644
index 0000000..9720bc2
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/pthread-stubs.cpp
@@ -0,0 +1,1426 @@
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <bits/ensure.h>
+#include <frg/allocation.hpp>
+#include <frg/array.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/thread.hpp>
+#include <mlibc/tcb.hpp>
+#include <mlibc/tid.hpp>
+#include <mlibc/threads.hpp>
+
+static bool enableTrace = false;
+
+struct ScopeTrace {
+	ScopeTrace(const char *file, int line, const char *function)
+	: _file(file), _line(line), _function(function) {
+		if(!enableTrace)
+			return;
+		mlibc::infoLogger() << "trace: Enter scope "
+				<< _file << ":" << _line << " (in function "
+				<< _function << ")" << frg::endlog;
+	}
+
+	~ScopeTrace() {
+		if(!enableTrace)
+			return;
+		mlibc::infoLogger() << "trace: Exit scope" << frg::endlog;
+	}
+
+private:
+	const char *_file;
+	int _line;
+	const char *_function;
+};
+
+#define SCOPE_TRACE() ScopeTrace(__FILE__, __LINE__, __FUNCTION__)
+
+static constexpr unsigned int mutexRecursive = 1;
+static constexpr unsigned int mutexErrorCheck = 2;
+
+// TODO: either use uint32_t or determine the bit based on sizeof(int).
+static constexpr unsigned int mutex_owner_mask = (static_cast<uint32_t>(1) << 30) - 1;
+static constexpr unsigned int mutex_waiters_bit = static_cast<uint32_t>(1) << 31;
+
+// Only valid for the internal __mlibc_m mutex of wrlocks.
+static constexpr unsigned int mutex_excl_bit = static_cast<uint32_t>(1) << 30;
+
+static constexpr unsigned int rc_count_mask = (static_cast<uint32_t>(1) << 31) - 1;
+static constexpr unsigned int rc_waiters_bit = static_cast<uint32_t>(1) << 31;
+
+static constexpr size_t default_stacksize = 0x200000;
+static constexpr size_t default_guardsize = 4096;
+
+// ----------------------------------------------------------------------------
+// pthread_attr and pthread functions.
+// ----------------------------------------------------------------------------
+
+// pthread_attr functions.
+int pthread_attr_init(pthread_attr_t *attr) {
+	*attr = pthread_attr_t{};
+	attr->__mlibc_stacksize = default_stacksize;
+	attr->__mlibc_guardsize = default_guardsize;
+	attr->__mlibc_detachstate = PTHREAD_CREATE_JOINABLE;
+	return 0;
+}
+
+int pthread_attr_destroy(pthread_attr_t *) {
+	return 0;
+}
+
+int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate) {
+	*detachstate = attr->__mlibc_detachstate;
+	return 0;
+}
+int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate) {
+	if (detachstate != PTHREAD_CREATE_DETACHED &&
+			detachstate != PTHREAD_CREATE_JOINABLE)
+		return EINVAL;
+
+	attr->__mlibc_detachstate = detachstate;
+	return 0;
+}
+
+int pthread_attr_getstacksize(const pthread_attr_t *__restrict attr, size_t *__restrict stacksize) {
+	*stacksize = attr->__mlibc_stacksize;
+	return 0;
+}
+
+int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize) {
+	if (stacksize < PTHREAD_STACK_MIN)
+		return EINVAL;
+	attr->__mlibc_stacksize = stacksize;
+	return 0;
+}
+
+int pthread_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr) {
+	*stackaddr = attr->__mlibc_stackaddr;
+	return 0;
+}
+int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr) {
+	attr->__mlibc_stackaddr = stackaddr;
+	return 0;
+}
+
+int pthread_attr_getstack(const pthread_attr_t *attr, void **stackaddr, size_t *stacksize) {
+	*stackaddr = attr->__mlibc_stackaddr;
+	*stacksize = attr->__mlibc_stacksize;
+	return 0;
+}
+int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr, size_t stacksize) {
+	if (stacksize < PTHREAD_STACK_MIN)
+		return EINVAL;
+	attr->__mlibc_stacksize = stacksize;
+	attr->__mlibc_stackaddr = stackaddr;
+	return 0;
+}
+
+int pthread_attr_getguardsize(const pthread_attr_t *__restrict attr, size_t *__restrict guardsize) {
+	*guardsize = attr->__mlibc_guardsize;
+	return 0;
+}
+int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize) {
+	attr->__mlibc_guardsize = guardsize;
+	return 0;
+}
+
+int pthread_attr_getscope(const pthread_attr_t *attr, int *scope) {
+	*scope = attr->__mlibc_scope;
+	return 0;
+}
+int pthread_attr_setscope(pthread_attr_t *attr, int scope) {
+	if (scope != PTHREAD_SCOPE_SYSTEM &&
+			scope != PTHREAD_SCOPE_PROCESS)
+		return EINVAL;
+	if (scope == PTHREAD_SCOPE_PROCESS)
+		return ENOTSUP;
+	attr->__mlibc_scope = scope;
+	return 0;
+}
+
+int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inheritsched) {
+	*inheritsched = attr->__mlibc_inheritsched;
+	return 0;
+}
+int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched) {
+	if (inheritsched != PTHREAD_INHERIT_SCHED &&
+			inheritsched != PTHREAD_EXPLICIT_SCHED)
+		return EINVAL;
+	attr->__mlibc_inheritsched = inheritsched;
+	return 0;
+}
+
+int pthread_attr_getschedparam(const pthread_attr_t *__restrict attr, struct sched_param *__restrict schedparam) {
+	*schedparam = attr->__mlibc_schedparam;
+	return 0;
+}
+int pthread_attr_setschedparam(pthread_attr_t *__restrict attr, const struct sched_param *__restrict schedparam) {
+	// TODO: this is supposed to return EINVAL for when the schedparam doesn't make sense
+	// for the given schedpolicy.
+	attr->__mlibc_schedparam = *schedparam;
+	return 0;
+}
+
+int pthread_attr_getschedpolicy(const pthread_attr_t *__restrict attr, int *__restrict policy) {
+	*policy = attr->__mlibc_schedpolicy;
+	return 0;
+}
+int pthread_attr_setschedpolicy(pthread_attr_t *__restrict attr, int policy) {
+	if (policy != SCHED_FIFO && policy != SCHED_RR &&
+			policy != SCHED_OTHER)
+		return EINVAL;
+	attr->__mlibc_schedpolicy = policy;
+	return 0;
+}
+
+#if __MLIBC_LINUX_OPTION
+int pthread_attr_getaffinity_np(const pthread_attr_t *__restrict attr,
+		size_t cpusetsize, cpu_set_t *__restrict cpusetp) {
+	if (!attr)
+		return EINVAL;
+
+	if (!attr->__mlibc_cpuset) {
+		memset(cpusetp, -1, cpusetsize);
+		return 0;
+	}
+
+	for (size_t cnt = cpusetsize; cnt < attr->__mlibc_cpusetsize; cnt++)
+		if (reinterpret_cast<char*>(attr->__mlibc_cpuset)[cnt] != '\0')
+			return ERANGE;
+
+	auto p = memcpy(cpusetp, attr->__mlibc_cpuset,
+			std::min(cpusetsize, attr->__mlibc_cpusetsize));
+	if (cpusetsize > attr->__mlibc_cpusetsize)
+		memset(p, '\0', cpusetsize - attr->__mlibc_cpusetsize);
+
+	return 0;
+}
+
+int pthread_attr_setaffinity_np(pthread_attr_t *__restrict attr,
+		size_t cpusetsize, const cpu_set_t *__restrict cpusetp) {
+	if (!attr)
+		return EINVAL;
+
+	if (!cpusetp || !cpusetsize) {
+		attr->__mlibc_cpuset = NULL;
+		attr->__mlibc_cpusetsize = 0;
+		return 0;
+	}
+
+	if (attr->__mlibc_cpusetsize != cpusetsize) {
+		auto newp = realloc(attr->__mlibc_cpuset, cpusetsize);
+		if (!newp)
+			return ENOMEM;
+
+		attr->__mlibc_cpuset = static_cast<cpu_set_t*>(newp);
+		attr->__mlibc_cpusetsize = cpusetsize;
+	}
+
+	memcpy(attr->__mlibc_cpuset, cpusetp, cpusetsize);
+	return 0;
+}
+
+int pthread_attr_getsigmask_np(const pthread_attr_t *__restrict attr,
+		sigset_t *__restrict sigmask) {
+	if (!attr)
+		return EINVAL;
+
+	if (!attr->__mlibc_sigmaskset) {
+		sigemptyset(sigmask);
+		return PTHREAD_ATTR_NO_SIGMASK_NP;
+	}
+
+	*sigmask = attr->__mlibc_sigmask;
+
+	return 0;
+}
+int pthread_attr_setsigmask_np(pthread_attr_t *__restrict attr,
+		const sigset_t *__restrict sigmask) {
+	if (!attr)
+		return EINVAL;
+
+	if (!sigmask) {
+		attr->__mlibc_sigmaskset = 0;
+		return 0;
+	}
+
+	attr->__mlibc_sigmask = *sigmask;
+	attr->__mlibc_sigmaskset = 1;
+
+	// Filter out internally used signals.
+	sigdelset(&attr->__mlibc_sigmask, SIGCANCEL);
+
+	return 0;
+}
+
+namespace {
+	void get_own_stackinfo(void **stack_addr, size_t *stack_size) {
+		auto fp = fopen("/proc/self/maps", "r");
+		if (!fp) {
+			mlibc::infoLogger() << "mlibc pthreads: /proc/self/maps does not exist! Producing incorrect"
+				" stack results!" << frg::endlog;
+			return;
+		}
+
+		char line[256];
+		auto sp = mlibc::get_sp();
+		while (fgets(line, 256, fp)) {
+			uintptr_t from, to;
+			if(sscanf(line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
+				continue;
+			if (sp < to && sp > from) {
+				// We need to return the lowest byte of the stack.
+				*stack_addr = reinterpret_cast<void*>(from);
+				*stack_size = to - from;
+				fclose(fp);
+				return;
+			}
+		}
+
+		fclose(fp);
+	}
+}
+
+int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+	*attr = pthread_attr_t{};
+
+	if (!tcb->stackAddr || !tcb->stackSize) {
+		get_own_stackinfo(&attr->__mlibc_stackaddr, &attr->__mlibc_stacksize);
+	} else {
+		attr->__mlibc_stacksize = tcb->stackSize;
+		attr->__mlibc_stackaddr = tcb->stackAddr;
+	}
+
+	attr->__mlibc_guardsize = tcb->guardSize;
+	attr->__mlibc_detachstate = tcb->isJoinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED;
+	mlibc::infoLogger() << "pthread_getattr_np(): Implementation is incomplete!" << frg::endlog;
+	return 0;
+}
+
+int pthread_getaffinity_np(pthread_t thread, size_t cpusetsize, cpu_set_t *mask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getthreadaffinity, ENOSYS);
+	return mlibc::sys_getthreadaffinity(reinterpret_cast<Tcb*>(thread)->tid, cpusetsize, mask);
+}
+
+int pthread_setaffinity_np(pthread_t thread, size_t cpusetsize, const cpu_set_t *mask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setthreadaffinity, ENOSYS);
+	return mlibc::sys_setthreadaffinity(reinterpret_cast<Tcb*>(thread)->tid, cpusetsize, mask);
+}
+#endif // __MLIBC_LINUX_OPTION
+
+extern "C" Tcb *__rtdl_allocateTcb();
+
+// pthread functions.
+int pthread_create(pthread_t *__restrict thread, const pthread_attr_t *__restrict attrp,
+		void *(*entry) (void *), void *__restrict user_arg) {
+	return mlibc::thread_create(thread, attrp, reinterpret_cast<void *>(entry), user_arg, false);
+}
+
+pthread_t pthread_self(void) {
+	return reinterpret_cast<pthread_t>(mlibc::get_current_tcb());
+}
+
+int pthread_equal(pthread_t t1, pthread_t t2) {
+	if(t1 == t2)
+		return 1;
+	return 0;
+}
+
+namespace {
+	struct key_global_info {
+		bool in_use;
+
+		void (*dtor)(void *);
+		uint64_t generation;
+	};
+
+	constinit frg::array<
+		key_global_info,
+		PTHREAD_KEYS_MAX
+	> key_globals_{};
+
+	FutexLock key_mutex_;
+}
+
+namespace mlibc {
+	__attribute__ ((__noreturn__)) void do_exit() {
+		sys_thread_exit();
+		__builtin_unreachable();
+	}
+}
+
+__attribute__ ((__noreturn__)) void pthread_exit(void *ret_val) {
+	auto self = mlibc::get_current_tcb();
+
+	if (__atomic_load_n(&self->cancelBits, __ATOMIC_RELAXED) & tcbExitingBit)
+		mlibc::do_exit();
+
+	__atomic_fetch_or(&self->cancelBits, tcbExitingBit, __ATOMIC_RELAXED);
+
+	auto hand = self->cleanupEnd;
+	while (hand) {
+		auto old = hand;
+		hand->func(hand->arg);
+		hand = hand->prev;
+		frg::destruct(getAllocator(), old);
+	}
+
+	for (size_t j = 0; j < PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
+		for (size_t i = 0; i < PTHREAD_KEYS_MAX; i++) {
+			if (auto v = pthread_getspecific(i)) {
+				key_mutex_.lock();
+				auto dtor = key_globals_[i].dtor;
+				key_mutex_.unlock();
+
+				if (dtor) {
+					dtor(v);
+					(*self->localKeys)[i].value = nullptr;
+				}
+			}
+		}
+	}
+
+	self->returnValue.voidPtr = ret_val;
+	__atomic_store_n(&self->didExit, 1, __ATOMIC_RELEASE);
+	mlibc::sys_futex_wake(&self->didExit);
+
+	// TODO: clean up thread resources when we are detached.
+
+	// TODO: do exit(0) when we're the only thread instead
+	mlibc::do_exit();
+}
+
+int pthread_join(pthread_t thread, void **ret) {
+	return mlibc::thread_join(thread, ret);
+}
+
+int pthread_detach(pthread_t thread) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+	if (!__atomic_load_n(&tcb->isJoinable, __ATOMIC_RELAXED))
+		return EINVAL;
+
+	int expected = 1;
+	if(!__atomic_compare_exchange_n(&tcb->isJoinable, &expected, 0, false, __ATOMIC_RELEASE,
+				__ATOMIC_RELAXED))
+		return EINVAL;
+
+	return 0;
+}
+
+void pthread_cleanup_push(void (*func) (void *), void *arg) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = frg::construct<Tcb::CleanupHandler>(getAllocator());
+	hand->func = func;
+	hand->arg = arg;
+	hand->next = nullptr;
+	hand->prev = self->cleanupEnd;
+
+	if (self->cleanupEnd)
+		self->cleanupEnd->next = hand;
+
+	self->cleanupEnd = hand;
+
+	if (!self->cleanupBegin)
+		self->cleanupBegin = self->cleanupEnd;
+}
+
+void pthread_cleanup_pop(int execute) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = self->cleanupEnd;
+
+	if (self->cleanupEnd)
+		self->cleanupEnd = self->cleanupEnd->prev;
+	if (self->cleanupEnd)
+		self->cleanupEnd->next = nullptr;
+
+	if (execute)
+		hand->func(hand->arg);
+
+	frg::destruct(getAllocator(), hand);
+}
+
+int pthread_setname_np(pthread_t thread, const char *name) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_thread_setname, ENOSYS);
+	if(int e = sysdep(tcb, name); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_getname_np(pthread_t thread, char *name, size_t size) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_thread_getname, ENOSYS);
+	if(int e = sysdep(tcb, name, size); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_setschedparam(pthread_t thread, int policy, const struct sched_param *param) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setschedparam, ENOSYS);
+	if(int e = mlibc::sys_setschedparam(tcb, policy, param); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_getschedparam(pthread_t thread, int *policy, struct sched_param *param) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getschedparam, ENOSYS);
+	if(int e = mlibc::sys_getschedparam(tcb, policy, param); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+//pthread cancel functions
+
+extern "C" void __mlibc_do_cancel() {
+	//TODO(geert): for now the same as pthread_exit()
+	pthread_exit(PTHREAD_CANCELED);
+}
+
+namespace {
+
+	void sigcancel_handler(int signal, siginfo_t *info, void *ucontext) {
+		ucontext_t *uctx = static_cast<ucontext_t*>(ucontext);
+		// The function could be called from other signals, or from another
+		// process, in which case we should do nothing.
+		if (signal != SIGCANCEL || info->si_pid != getpid() ||
+				info->si_code != SI_TKILL)
+			return;
+
+		auto tcb = reinterpret_cast<Tcb*>(mlibc::get_current_tcb());
+		int old_value = tcb->cancelBits;
+
+		/*
+		 * When a thread is marked with deferred cancellation and performs a blocking syscall,
+		 * the spec mandates that the syscall can get interrupted before it has caused any side
+		 * effects (e.g. before a read() has read any bytes from disk). If the syscall has
+		 * already caused side effects it should return its partial work, and set the program
+		 * counter just after the syscall. If the syscall hasn't caused any side effects, it
+		 * should fail with EINTR and set the program counter to the syscall instruction.
+		 *
+		 *	cancellable_syscall:
+		 *		test whether_a_cancel_is_queued
+		 *		je cancel
+		 *		syscall
+		 *	end_cancellable_syscall
+		 *
+		 * The mlibc::sys_before_cancellable_syscall sysdep should return 1 when the
+		 * program counter is between the 'canellable_syscall' and 'end_cancellable_syscall' label.
+		 */
+		if (!(old_value & tcbCancelAsyncBit) &&
+				mlibc::sys_before_cancellable_syscall && !mlibc::sys_before_cancellable_syscall(uctx))
+			return;
+
+		int bitmask = tcbCancelTriggerBit | tcbCancelingBit;
+		while (1) {
+			int new_value = old_value | bitmask;
+
+			// Check if we are already cancelled or exiting
+			if (old_value == new_value || old_value & tcbExitingBit)
+				return;
+
+			int current_value = old_value;
+			if (__atomic_compare_exchange_n(&tcb->cancelBits, &current_value,
+						new_value, true,__ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+				tcb->returnValue.voidPtr = PTHREAD_CANCELED;
+
+				// Perform cancellation
+				__mlibc_do_cancel();
+
+				break;
+			}
+
+			old_value = current_value;
+		}
+	}
+}
+
+namespace mlibc {
+namespace {
+
+struct PthreadSignalInstaller {
+	PthreadSignalInstaller() {
+		struct sigaction sa;
+		sa.sa_sigaction = sigcancel_handler;
+		sa.sa_flags = SA_SIGINFO;
+		auto e = ENOSYS;
+		if(sys_sigaction)
+			e = sys_sigaction(SIGCANCEL, &sa, NULL);
+		// Opt-out of cancellation support.
+		if(e == ENOSYS)
+			return;
+		__ensure(!e);
+	}
+};
+
+PthreadSignalInstaller pthread_signal_installer;
+
+} // anonymous namespace
+} // namespace mlibc
+
+int pthread_setcanceltype(int type, int *oldtype) {
+	if (type != PTHREAD_CANCEL_DEFERRED && type != PTHREAD_CANCEL_ASYNCHRONOUS)
+		return EINVAL;
+
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int old_value = self->cancelBits;
+	while (1) {
+		int new_value = old_value & ~tcbCancelAsyncBit;
+		if (type == PTHREAD_CANCEL_ASYNCHRONOUS)
+			new_value |= tcbCancelAsyncBit;
+
+		if (oldtype)
+			*oldtype = ((old_value & tcbCancelAsyncBit)
+					? PTHREAD_CANCEL_ASYNCHRONOUS
+					: PTHREAD_CANCEL_DEFERRED);
+
+		// Avoid unecessary atomic op.
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&self->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+
+			if (mlibc::tcb_async_cancelled(new_value))
+				__mlibc_do_cancel();
+
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+int pthread_setcancelstate(int state, int *oldstate) {
+	if (state != PTHREAD_CANCEL_ENABLE && state != PTHREAD_CANCEL_DISABLE)
+		return EINVAL;
+
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int old_value = self->cancelBits;
+	while (1) {
+		int new_value = old_value & ~tcbCancelEnableBit;
+		if (state == PTHREAD_CANCEL_ENABLE)
+			new_value |= tcbCancelEnableBit;
+
+		if (oldstate)
+			*oldstate = ((old_value & tcbCancelEnableBit)
+					? PTHREAD_CANCEL_ENABLE
+					: PTHREAD_CANCEL_DISABLE);
+
+		// Avoid unecessary atomic op.
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&self->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+
+			if (mlibc::tcb_async_cancelled(new_value))
+				__mlibc_do_cancel();
+
+			sigset_t set = {};
+			sigaddset(&set, SIGCANCEL);
+			if (new_value & PTHREAD_CANCEL_ENABLE)
+				sigprocmask(SIG_UNBLOCK, &set, NULL);
+			else
+				sigprocmask(SIG_BLOCK, &set, NULL);
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+void pthread_testcancel(void) {
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int value = self->cancelBits;
+	if ((value & tcbCancelEnableBit) && (value & tcbCancelTriggerBit)) {
+		__mlibc_do_cancel();
+		__builtin_unreachable();
+	}
+}
+int pthread_cancel(pthread_t thread) {
+	if (!mlibc::sys_tgkill) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	auto tcb = reinterpret_cast<Tcb *>(thread);
+	// Check if the TCB is valid, somewhat..
+	if (tcb->selfPointer != tcb)
+		return ESRCH;
+
+	int old_value = __atomic_load_n(&tcb->cancelBits, __ATOMIC_RELAXED);
+	while (1) {
+		int bitmask = tcbCancelTriggerBit;
+
+		int new_value = old_value | bitmask;
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&tcb->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+			if (mlibc::tcb_cancel_enabled(new_value)) {
+				pid_t pid = getpid();
+
+				int res = mlibc::sys_tgkill(pid, tcb->tid, SIGCANCEL);
+
+				current_value = __atomic_load_n(&tcb->cancelBits, __ATOMIC_RELAXED);
+
+				// If we can't find the thread anymore, it's possible that it exited between
+				// us setting the cancel trigger bit, and us sending the signal. Check the
+				// cancelBits for tcbExitingBit to confirm that.
+				// XXX(qookie): This will be an use-after-free once we start freeing TCBs on
+				//              exit. Perhaps the TCB should be refcounted.
+				if (!(res == ESRCH && (current_value & tcbExitingBit)))
+					return res;
+			}
+
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+
+int pthread_atfork(void (*prepare) (void), void (*parent) (void), void (*child) (void)) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = frg::construct<Tcb::AtforkHandler>(getAllocator());
+	if (!hand)
+		return -1;
+
+	hand->prepare = prepare;
+	hand->parent = parent;
+	hand->child = child;
+	hand->next = nullptr;
+	hand->prev = self->atforkEnd;
+
+	if (self->atforkEnd)
+		self->atforkEnd->next = hand;
+
+	self->atforkEnd = hand;
+
+	if (!self->atforkBegin)
+		self->atforkBegin = self->atforkEnd;
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_key functions.
+// ----------------------------------------------------------------------------
+
+int pthread_key_create(pthread_key_t *out, void (*destructor)(void *)) {
+	SCOPE_TRACE();
+
+	auto g = frg::guard(&key_mutex_);
+
+	pthread_key_t key = PTHREAD_KEYS_MAX;
+	for (size_t i = 0; i < PTHREAD_KEYS_MAX; i++) {
+		if (!key_globals_[i].in_use) {
+			key = i;
+			break;
+		}
+	}
+
+	if (key == PTHREAD_KEYS_MAX)
+		return EAGAIN;
+
+	key_globals_[key].in_use = true;
+	key_globals_[key].dtor = destructor;
+
+	*out = key;
+
+	return 0;
+}
+
+int pthread_key_delete(pthread_key_t key) {
+	SCOPE_TRACE();
+
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return EINVAL;
+
+	key_globals_[key].in_use = false;
+	key_globals_[key].dtor = nullptr;
+	key_globals_[key].generation++;
+
+	return 0;
+}
+
+void *pthread_getspecific(pthread_key_t key) {
+	SCOPE_TRACE();
+
+	auto self = mlibc::get_current_tcb();
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return nullptr;
+
+	if (key_globals_[key].generation > (*self->localKeys)[key].generation) {
+		(*self->localKeys)[key].value = nullptr;
+		(*self->localKeys)[key].generation = key_globals_[key].generation;
+	}
+
+	return (*self->localKeys)[key].value;
+}
+
+int pthread_setspecific(pthread_key_t key, const void *value) {
+	SCOPE_TRACE();
+
+	auto self = mlibc::get_current_tcb();
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return EINVAL;
+
+	(*self->localKeys)[key].value = const_cast<void *>(value);
+	(*self->localKeys)[key].generation = key_globals_[key].generation;
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_once functions.
+// ----------------------------------------------------------------------------
+
+static constexpr unsigned int onceComplete = 1;
+static constexpr unsigned int onceLocked = 2;
+
+int pthread_once(pthread_once_t *once, void (*function) (void)) {
+	SCOPE_TRACE();
+
+	auto expected = __atomic_load_n(&once->__mlibc_done, __ATOMIC_ACQUIRE);
+
+	// fast path: the function was already run.
+	while(!(expected & onceComplete)) {
+		if(!expected) {
+			// try to acquire the mutex.
+			if(!__atomic_compare_exchange_n(&once->__mlibc_done,
+					&expected, onceLocked, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
+				continue;
+
+			function();
+
+			// unlock the mutex.
+			__atomic_exchange_n(&once->__mlibc_done, onceComplete, __ATOMIC_RELEASE);
+			if(int e = mlibc::sys_futex_wake((int *)&once->__mlibc_done); e)
+				__ensure(!"sys_futex_wake() failed");
+			return 0;
+		}else{
+			// a different thread is currently running the initializer.
+			__ensure(expected == onceLocked);
+			if(int e = mlibc::sys_futex_wait((int *)&once->__mlibc_done, onceLocked, nullptr); e)
+				__ensure(!"sys_futex_wait() failed");
+			expected =  __atomic_load_n(&once->__mlibc_done, __ATOMIC_ACQUIRE);
+		}
+	}
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_mutexattr and pthread_mutex functions.
+// ----------------------------------------------------------------------------
+
+// pthread_mutexattr functions
+int pthread_mutexattr_init(pthread_mutexattr_t *attr) {
+	SCOPE_TRACE();
+	return mlibc::thread_mutexattr_init(attr);
+}
+
+int pthread_mutexattr_destroy(pthread_mutexattr_t *attr) {
+	SCOPE_TRACE();
+	return mlibc::thread_mutexattr_destroy(attr);
+}
+
+int pthread_mutexattr_gettype(const pthread_mutexattr_t *__restrict attr, int *__restrict type) {
+	return mlibc::thread_mutexattr_gettype(attr, type);
+}
+
+int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type) {
+	return mlibc::thread_mutexattr_settype(attr, type);
+}
+
+int pthread_mutexattr_getrobust(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict robust) {
+	*robust = attr->__mlibc_robust;
+	return 0;
+}
+int pthread_mutexattr_setrobust(pthread_mutexattr_t *attr, int robust) {
+	if (robust != PTHREAD_MUTEX_STALLED && robust != PTHREAD_MUTEX_ROBUST)
+		return EINVAL;
+
+	attr->__mlibc_robust = robust;
+	return 0;
+}
+
+int pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict protocol) {
+	*protocol = attr->__mlibc_protocol;
+	return 0;
+}
+
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol) {
+	if (protocol != PTHREAD_PRIO_NONE && protocol != PTHREAD_PRIO_INHERIT
+			&& protocol != PTHREAD_PRIO_PROTECT)
+		return EINVAL;
+
+	attr->__mlibc_protocol = protocol;
+	return 0;
+}
+
+int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict prioceiling) {
+	(void)attr;
+	(void)prioceiling;
+	return EINVAL;
+}
+
+int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling) {
+	(void)attr;
+	(void)prioceiling;
+	return EINVAL;
+}
+
+// pthread_mutex functions
+int pthread_mutex_init(pthread_mutex_t *__restrict mutex,
+		const pthread_mutexattr_t *__restrict attr) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_init(mutex, attr);
+}
+
+int pthread_mutex_destroy(pthread_mutex_t *mutex) {
+	return mlibc::thread_mutex_destroy(mutex);
+}
+
+int pthread_mutex_lock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_lock(mutex);
+}
+
+int pthread_mutex_trylock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	unsigned int this_tid = mlibc::this_tid();
+	unsigned int expected = __atomic_load_n(&mutex->__mlibc_state, __ATOMIC_RELAXED);
+	if(!expected) {
+		// Try to take the mutex here.
+		if(__atomic_compare_exchange_n(&mutex->__mlibc_state,
+						&expected, this_tid, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) {
+			__ensure(!mutex->__mlibc_recursion);
+			mutex->__mlibc_recursion = 1;
+			return 0;
+		}
+	} else {
+		// If this (recursive) mutex is already owned by us, increment the recursion level.
+		if((expected & mutex_owner_mask) == this_tid) {
+			if(!(mutex->__mlibc_flags & mutexRecursive)) {
+				return EBUSY;
+			}
+			++mutex->__mlibc_recursion;
+			return 0;
+		}
+	}
+
+	return EBUSY;
+}
+
+int pthread_mutex_timedlock(pthread_mutex_t *__restrict,
+		const struct timespec *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int pthread_mutex_unlock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_unlock(mutex);
+}
+
+int pthread_mutex_consistent(pthread_mutex_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// ----------------------------------------------------------------------------
+// pthread_condattr and pthread_cond functions.
+// ----------------------------------------------------------------------------
+
+int pthread_condattr_init(pthread_condattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	attr->__mlibc_clock = CLOCK_REALTIME;
+	return 0;
+}
+
+int pthread_condattr_destroy(pthread_condattr_t *attr) {
+	memset(attr, 0, sizeof(*attr));
+	return 0;
+}
+
+int pthread_condattr_getclock(const pthread_condattr_t *__restrict attr,
+		clockid_t *__restrict clock) {
+	*clock = attr->__mlibc_clock;
+	return 0;
+}
+
+int pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clock) {
+	if (clock != CLOCK_REALTIME && clock != CLOCK_MONOTONIC
+			&& clock != CLOCK_MONOTONIC_RAW && clock != CLOCK_REALTIME_COARSE
+			&& clock != CLOCK_MONOTONIC_COARSE && clock != CLOCK_BOOTTIME)
+		return EINVAL;
+
+	attr->__mlibc_clock = clock;
+	return 0;
+}
+
+int pthread_condattr_getpshared(const pthread_condattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_condattr_setpshared(pthread_condattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_cond_init(pthread_cond_t *__restrict cond, const pthread_condattr_t *__restrict attr) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_init(cond, attr);
+}
+
+int pthread_cond_destroy(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_destroy(cond);
+}
+
+int pthread_cond_wait(pthread_cond_t *__restrict cond, pthread_mutex_t *__restrict mutex) {
+	return pthread_cond_timedwait(cond, mutex, nullptr);
+}
+
+int pthread_cond_timedwait(pthread_cond_t *__restrict cond, pthread_mutex_t *__restrict mutex,
+		const struct timespec *__restrict abstime) {
+	return mlibc::thread_cond_timedwait(cond, mutex, abstime);
+}
+
+int pthread_cond_signal(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return pthread_cond_broadcast(cond);
+}
+
+int pthread_cond_broadcast(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_broadcast(cond);
+}
+
+// ----------------------------------------------------------------------------
+// pthread_barrierattr and pthread_barrier functions.
+// ----------------------------------------------------------------------------
+
+int pthread_barrierattr_init(pthread_barrierattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	return 0;
+}
+
+int pthread_barrierattr_getpshared(const pthread_barrierattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_barrierattr_destroy(pthread_barrierattr_t *) {
+	return 0;
+}
+
+int pthread_barrier_init(pthread_barrier_t *__restrict barrier,
+		const pthread_barrierattr_t *__restrict attr, unsigned count) {
+	if (count == 0)
+		return EINVAL;
+
+	barrier->__mlibc_waiting = 0;
+	barrier->__mlibc_inside = 0;
+	barrier->__mlibc_seq = 0;
+	barrier->__mlibc_count = count;
+
+	// Since we don't implement these yet, set a flag to error later.
+	auto pshared = attr ? attr->__mlibc_pshared : PTHREAD_PROCESS_PRIVATE;
+	barrier->__mlibc_flags = pshared;
+
+	return 0;
+}
+
+int pthread_barrier_destroy(pthread_barrier_t *barrier) {
+	// Wait until there are no threads still using the barrier.
+	unsigned inside = 0;
+	do {
+		unsigned expected = __atomic_load_n(&barrier->__mlibc_inside, __ATOMIC_RELAXED);
+		if (expected == 0)
+			break;
+
+		int e = mlibc::sys_futex_wait((int *)&barrier->__mlibc_inside, expected, nullptr);
+		if (e != 0 && e != EAGAIN && e != EINTR)
+			mlibc::panicLogger() << "mlibc: sys_futex_wait() returned error " << e << frg::endlog;
+	} while (inside > 0);
+
+	memset(barrier, 0, sizeof *barrier);
+	return 0;
+}
+
+int pthread_barrier_wait(pthread_barrier_t *barrier) {
+	if (barrier->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_barrier_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// inside is incremented on entry and decremented on exit.
+	// This is used to synchronise with pthread_barrier_destroy, to ensure that a thread doesn't pass
+	// the barrier and immediately destroy its state while other threads still rely on it.
+
+	__atomic_fetch_add(&barrier->__mlibc_inside, 1, __ATOMIC_ACQUIRE);
+
+	auto leave = [&](){
+		unsigned inside = __atomic_sub_fetch(&barrier->__mlibc_inside, 1, __ATOMIC_RELEASE);
+		if (inside == 0)
+			mlibc::sys_futex_wake((int *)&barrier->__mlibc_inside);
+	};
+
+	unsigned seq = __atomic_load_n(&barrier->__mlibc_seq, __ATOMIC_ACQUIRE);
+
+	while (true) {
+		unsigned expected = __atomic_load_n(&barrier->__mlibc_waiting, __ATOMIC_RELAXED);
+		bool swapped = __atomic_compare_exchange_n(&barrier->__mlibc_waiting, &expected, expected + 1, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
+
+		if (swapped) {
+			if (expected + 1 == barrier->__mlibc_count) {
+				// We were the last thread to hit the barrier. Reset waiters and wake the others.
+				__atomic_fetch_add(&barrier->__mlibc_seq, 1, __ATOMIC_ACQUIRE);
+				__atomic_store_n(&barrier->__mlibc_waiting, 0, __ATOMIC_RELEASE);
+
+				mlibc::sys_futex_wake((int *)&barrier->__mlibc_seq);
+
+				leave();
+				return PTHREAD_BARRIER_SERIAL_THREAD;
+			}
+
+			while (true) {
+				int e = mlibc::sys_futex_wait((int *)&barrier->__mlibc_seq, seq, nullptr);
+				if (e != 0 && e != EAGAIN && e != EINTR)
+					mlibc::panicLogger() << "mlibc: sys_futex_wait() returned error " << e << frg::endlog;
+
+				unsigned newSeq = __atomic_load_n(&barrier->__mlibc_seq, __ATOMIC_ACQUIRE);
+				if (newSeq > seq) {
+					leave();
+					return 0;
+				}
+			}
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------
+// pthread_rwlock functions.
+// ----------------------------------------------------------------------------
+
+namespace {
+	void rwlock_m_lock(pthread_rwlock_t *rw, bool excl) {
+		unsigned int m_expected = __atomic_load_n(&rw->__mlibc_m, __ATOMIC_RELAXED);
+		while(true) {
+			if(m_expected) {
+				__ensure(m_expected & mutex_owner_mask);
+
+				// Try to set the waiters bit.
+				if(!(m_expected & mutex_waiters_bit)) {
+					unsigned int desired = m_expected | mutex_waiters_bit;
+					if(!__atomic_compare_exchange_n(&rw->__mlibc_m,
+							&m_expected, desired, false, __ATOMIC_RELAXED, __ATOMIC_RELAXED))
+						continue;
+				}
+
+				// Wait on the futex.
+				mlibc::sys_futex_wait((int *)&rw->__mlibc_m, m_expected | mutex_waiters_bit, nullptr);
+
+				// Opportunistically try to take the lock after we wake up.
+				m_expected = 0;
+			}else{
+				// Try to lock the mutex.
+				unsigned int desired = 1;
+				if(excl)
+					desired |= mutex_excl_bit;
+				if(__atomic_compare_exchange_n(&rw->__mlibc_m,
+						&m_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+					break;
+			}
+		}
+	}
+
+	int rwlock_m_trylock(pthread_rwlock_t *rw, bool excl) {
+		unsigned int m_expected = __atomic_load_n(&rw->__mlibc_m, __ATOMIC_RELAXED);
+		if(!m_expected) {
+			// Try to lock the mutex.
+			unsigned int desired = 1;
+			if(excl)
+				desired |= mutex_excl_bit;
+			if(__atomic_compare_exchange_n(&rw->__mlibc_m,
+					&m_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+				return 0;
+		}
+
+		__ensure(m_expected & mutex_owner_mask);
+
+		// POSIX says that this function should never block but also that
+		// readers should not be blocked by readers. We implement this by returning EAGAIN
+		// (and not EBUSY) if a reader would block a reader.
+		if(!excl && !(m_expected & mutex_excl_bit))
+			return EAGAIN;
+
+		return EBUSY;
+	}
+
+	void rwlock_m_unlock(pthread_rwlock_t *rw) {
+		auto m = __atomic_exchange_n(&rw->__mlibc_m, 0, __ATOMIC_RELEASE);
+		if(m & mutex_waiters_bit)
+			mlibc::sys_futex_wake((int *)&rw->__mlibc_m);
+	}
+}
+
+int pthread_rwlockattr_init(pthread_rwlockattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	return 0;
+}
+
+int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_rwlockattr_destroy(pthread_rwlockattr_t *) {
+	return 0;
+}
+
+int pthread_rwlock_init(pthread_rwlock_t *__restrict rw, const pthread_rwlockattr_t *__restrict attr) {
+	SCOPE_TRACE();
+	rw->__mlibc_m = 0;
+	rw->__mlibc_rc = 0;
+
+	// Since we don't implement this yet, set a flag to error later.
+	auto pshared = attr ? attr->__mlibc_pshared : PTHREAD_PROCESS_PRIVATE;
+	rw->__mlibc_flags = pshared;
+	return 0;
+}
+
+int pthread_rwlock_destroy(pthread_rwlock_t *rw) {
+	__ensure(!rw->__mlibc_m);
+	__ensure(!rw->__mlibc_rc);
+	return 0;
+}
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Take the __mlibc_m mutex.
+	// Will be released in pthread_rwlock_unlock().
+	if(int e = rwlock_m_trylock(rw, true))
+		return e;
+
+	// Check that there are no readers.
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	if(rc_expected) {
+		rwlock_m_unlock(rw);
+		return EBUSY;
+	}
+
+	return 0;
+}
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Take the __mlibc_m mutex.
+	// Will be released in pthread_rwlock_unlock().
+	rwlock_m_lock(rw, true);
+
+	// Now wait until there are no more readers.
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	while(true) {
+		if(!rc_expected)
+			break;
+
+		__ensure(rc_expected & rc_count_mask);
+
+		// Try to set the waiters bit.
+		if(!(rc_expected & rc_waiters_bit)) {
+			unsigned int desired = rc_expected | rc_count_mask;
+			if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+					&rc_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
+				continue;
+		}
+
+		// Wait on the futex.
+		mlibc::sys_futex_wait((int *)&rw->__mlibc_rc, rc_expected | rc_waiters_bit, nullptr);
+
+		// Re-check the reader counter.
+		rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	}
+
+	return 0;
+}
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Increment the reader count while holding the __mlibc_m mutex.
+	if(int e = rwlock_m_trylock(rw, false); e)
+		return e;
+	__atomic_fetch_add(&rw->__mlibc_rc, 1, __ATOMIC_ACQUIRE);
+	rwlock_m_unlock(rw);
+
+	return 0;
+}
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Increment the reader count while holding the __mlibc_m mutex.
+	rwlock_m_lock(rw, false);
+	__atomic_fetch_add(&rw->__mlibc_rc, 1, __ATOMIC_ACQUIRE);
+	rwlock_m_unlock(rw);
+
+	return 0;
+}
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_RELAXED);
+	if(!rc_expected) {
+		// We are doing a write-unlock.
+		rwlock_m_unlock(rw);
+		return 0;
+	}else{
+		// We are doing a read-unlock.
+		while(true) {
+			unsigned int count = rc_expected & rc_count_mask;
+			__ensure(count);
+
+			// Try to decrement the count.
+			if(count == 1 && (rc_expected & rc_waiters_bit)) {
+				unsigned int desired = 0;
+				if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+						&rc_expected, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED))
+					continue;
+
+				// Wake the futex.
+				mlibc::sys_futex_wake((int *)&rw->__mlibc_rc);
+				break;
+			}else{
+				unsigned int desired = (rc_expected & ~rc_count_mask) | (count - 1);
+				if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+						&rc_expected, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED))
+					continue;
+				break;
+			}
+		}
+
+		return 0;
+	}
+}
+
+int pthread_getcpuclockid(pthread_t, clockid_t *) {
+	mlibc::infoLogger() << "mlibc: pthread_getcpuclockid() always returns ENOENT"
+			<< frg::endlog;
+	return ENOENT;
+}
diff --git a/lib/mlibc/options/posix/generic/pwd-stubs.cpp b/lib/mlibc/options/posix/generic/pwd-stubs.cpp
new file mode 100644
index 0000000..5d8f618
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/pwd-stubs.cpp
@@ -0,0 +1,284 @@
+
+#include <errno.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+
+namespace {
+	FILE *global_file; // Used by setpwent/getpwent/endpwent.
+
+	bool open_global_file() {
+		if(!global_file) {
+			global_file = fopen("/etc/passwd", "r");
+			if(!global_file) {
+				errno = EIO;
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	void close_global_file() {
+		if(global_file) {
+			fclose(global_file);
+			global_file = nullptr;
+		}
+	}
+
+	bool extract_entry(frg::string_view line, passwd *entry) {
+		frg::string_view segments[8];
+
+		// Parse the line into 7 or 8 segments.
+		size_t s = 0;
+		int n;
+		for(n = 0; n < 7; n++) {
+			size_t d = line.find_first(':', s);
+			if(d == size_t(-1))
+				break;
+			segments[n] = line.sub_string(s, d - s);
+			s = d + 1;
+		}
+		if(line.find_first(':', s) != size_t(-1))
+			return false;
+		segments[n] = line.sub_string(s, line.size() - s);
+		n++;
+
+		if(n < 7)
+			return false;
+
+		// TODO: Handle strndup() failure.
+		auto name = strndup(segments[0].data(), segments[0].size());
+		__ensure(name);
+
+		auto passwd = strndup(segments[1].data(), segments[1].size());
+		__ensure(passwd);
+
+		auto uid = segments[2].to_number<int>();
+		if(!uid)
+			return false;
+		auto gid = segments[3].to_number<int>();
+		if(!gid)
+			return false;
+
+		auto real_name = strndup(segments[4].data(), segments[4].size());
+		__ensure(real_name);
+		auto dir = strndup(segments[5].data(), segments[5].size());
+		__ensure(dir);
+		auto shell = strndup(segments[6].data(), segments[6].size());
+		__ensure(shell);
+
+		// Chop the newline off the end of shell
+		__ensure(strlen(shell) > 0);
+		shell[strlen(shell) - 1] = '\0';
+
+		entry->pw_name = name;
+		entry->pw_passwd = passwd;
+		entry->pw_uid = *uid;
+		entry->pw_gid = *gid;
+		entry->pw_dir = dir;
+		entry->pw_shell = shell;
+		entry->pw_gecos = real_name;
+		return true;
+	}
+
+	void copy_to_buffer(passwd *pwd, char *buffer, size_t size) {
+		char *pw_dir = stpcpy(buffer, pwd->pw_name) + 1;
+		free(pwd->pw_name);
+		pwd->pw_name = buffer;
+
+		char *pw_shell = stpcpy(pw_dir, pwd->pw_dir) + 1;
+		free(pwd->pw_dir);
+		pwd->pw_dir = pw_dir;
+
+		char *pw_passwd = stpcpy(pw_shell, pwd->pw_shell) + 1;
+		free(pwd->pw_shell);
+		pwd->pw_shell = pw_shell;
+
+		char *end = stpcpy(pw_passwd, pwd->pw_passwd);
+		__ensure(end <= buffer + size);
+		free(pwd->pw_passwd);
+		pwd->pw_passwd = pw_passwd;
+	}
+
+	void clear_entry(passwd *entry) {
+		free(entry->pw_name);
+		free(entry->pw_dir);
+		free(entry->pw_passwd);
+		free(entry->pw_shell);
+		entry->pw_name = nullptr;
+		entry->pw_dir = nullptr;
+		entry->pw_passwd = nullptr;
+		entry->pw_shell = nullptr;
+	}
+}
+
+struct passwd *getpwent(void) {
+	static passwd entry;
+	char line[NSS_BUFLEN_PASSWD];
+
+	if(!open_global_file()) {
+		return nullptr;
+	}
+
+	if (fgets(line, NSS_BUFLEN_PASSWD, global_file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry)) {
+			errno = EINVAL;	// I suppose this can be a valid errno?
+			return nullptr;
+		}
+		return &entry;
+	}
+
+	if(ferror(global_file)) {
+		errno = EIO;
+	}
+
+	return nullptr;
+}
+
+struct passwd *getpwnam(const char *name) {
+	static passwd entry;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file)
+		return nullptr;
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry))
+			continue;
+		if(!strcmp(entry.pw_name, name)) {
+			fclose(file);
+			return &entry;
+		}
+	}
+
+	int err = errno;
+	if(ferror(file)) {
+		err = EIO;
+	}
+
+	fclose(file);
+	errno = err;
+	return nullptr;
+}
+
+int getpwnam_r(const char *name, struct passwd *pwd, char *buffer, size_t size, struct passwd **result) {
+	*result = nullptr;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file) {
+		return EIO;
+	}
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		if(!extract_entry(line, pwd))
+			continue;
+		if(!strcmp(pwd->pw_name, name)) {
+			fclose(file);
+
+			size_t required_size = strlen(pwd->pw_name) + strlen(pwd->pw_dir)
+				+ strlen(pwd->pw_shell) + strlen(pwd->pw_passwd) + 4;
+			if (size < required_size)
+				return ERANGE;
+
+			copy_to_buffer(pwd, buffer, size);
+			*result = pwd;
+			return 0;
+		}
+	}
+
+	int ret = 0;
+	if(ferror(file)) {
+		ret = EIO;
+	}
+
+	fclose(file);
+	return ret;
+}
+
+struct passwd *getpwuid(uid_t uid) {
+	static passwd entry;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file)
+		return nullptr;
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry))
+			continue;
+		if(entry.pw_uid == uid) {
+			fclose(file);
+			return &entry;
+		}
+	}
+
+	int err = ESRCH;
+	if(ferror(file)) {
+		err = EIO;
+	}
+
+	fclose(file);
+	errno = err;
+	return nullptr;
+}
+
+int getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer, size_t size, struct passwd **result) {
+	*result = nullptr;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file) {
+		return EIO;
+	}
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		if(!extract_entry(line, pwd))
+			continue;
+		if(pwd->pw_uid == uid) {
+			fclose(file);
+
+			size_t required_size = strlen(pwd->pw_name) + strlen(pwd->pw_dir)
+				+ strlen(pwd->pw_shell) + + strlen(pwd->pw_passwd) + 4;
+			if (size < required_size)
+				return ERANGE;
+
+			copy_to_buffer(pwd, buffer, size);
+			*result = pwd;
+			return 0;
+		}
+	}
+
+	int ret = 0;
+	if(ferror(file)) {
+		ret = EIO;
+	}
+
+	fclose(file);
+	return ret;
+}
+
+void setpwent(void) {
+	if(!open_global_file()) {
+		return;
+	}
+	rewind(global_file);
+}
+
+void endpwent(void) {
+	close_global_file();
+}
+
+int putpwent(const struct passwd *, FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct passwd *fgetpwent(FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/resolv_conf.cpp b/lib/mlibc/options/posix/generic/resolv_conf.cpp
new file mode 100644
index 0000000..a5c3aa7
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/resolv_conf.cpp
@@ -0,0 +1,42 @@
+#include <mlibc/resolv_conf.hpp>
+#include <mlibc/allocator.hpp>
+#include <stdio.h>
+#include <ctype.h>
+
+namespace mlibc {
+
+frg::optional<struct nameserver_data> get_nameserver() {
+	auto file = fopen("/etc/resolv.conf", "r");
+	if (!file)
+		return frg::null_opt;
+
+	char line[128];
+	struct nameserver_data ret;
+	while (fgets(line, 128, file)) {
+		char *pos;
+		if (!strchr(line, '\n') && !feof(file)) {
+			// skip truncated lines
+			for (int c = getc(file); c != '\n' && c != EOF; c = getc(file));
+			continue;
+		}
+
+		// TODO(geert): resolv.conf can actually have multiple nameservers
+		// but we just pick the first one for now
+		if (!strncmp(line, "nameserver", 10) && isspace(line[10])) {
+			char *end;
+			for (pos = line + 11; isspace(*pos); pos++);
+			for (end = pos; *end && !isspace(*end); end++);
+			*end = '\0';
+			ret.name = frg::string<MemoryAllocator>(
+					pos, end - pos, getAllocator());
+			break;
+		}
+	}
+
+	fclose(file);
+	if(ret.name.empty())
+		return frg::null_opt;
+	return ret;
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/sched-stubs.cpp b/lib/mlibc/options/posix/generic/sched-stubs.cpp
new file mode 100644
index 0000000..9d75d50
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sched-stubs.cpp
@@ -0,0 +1,50 @@
+
+#include <bits/ensure.h>
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int sched_yield(void) {
+	if(mlibc::sys_yield) {
+		mlibc::sys_yield();
+	}else{
+		// Missing sched_yield() is not an error.
+		MLIBC_MISSING_SYSDEP();
+	}
+	return 0;
+}
+
+int sched_get_priority_max(int policy) {
+	int res = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_get_max_priority, -1);
+	if(int e = sysdep(policy, &res); e) {
+		errno = e;
+		return -1;
+	}
+	return res;
+}
+
+int sched_get_priority_min(int policy) {
+	int res = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_get_min_priority, -1);
+	if(int e = sysdep(policy, &res); e) {
+		errno = e;
+		return -1;
+	}
+	return res;
+}
+
+int sched_setscheduler(pid_t, int, const struct sched_param *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sched_getparam(pid_t, struct sched_param *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/search.cpp b/lib/mlibc/options/posix/generic/search.cpp
new file mode 100644
index 0000000..e6f8c1d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/search.cpp
@@ -0,0 +1,151 @@
+
+#include <bits/ensure.h>
+#include <search.h>
+#include <stddef.h>
+#include <new>
+#include <mlibc/allocator.hpp>
+#include <frg/stack.hpp>
+#include <stdlib.h>
+
+struct node {
+	const void *key;
+	void *a[2];
+	int h;
+};
+
+namespace {
+	int height(struct node *node) {
+		return node ? node->h : 0;
+	}
+
+	int rotate(struct node **nodep, int side) {
+		struct node *node = *nodep;
+		struct node *x = static_cast<struct node *>(node->a[side]);
+		struct node *y = static_cast<struct node *>(x->a[!side]);
+		struct node *z = static_cast<struct node *>(x->a[side]);
+
+		int height_node = node->h;
+		int height_y = height(y);
+		if (height_y > height(z)) {
+			// Perform double rotation
+			node->a[side] = y->a[!side];
+			x->a[!side] = y->a[side];
+			y->a[!side] = node;
+			y->a[side] = x;
+			node->h = height_y;
+			x->h = height_y;
+			y->h = height_y + 1;
+		} else {
+			// Perform single rotation
+			node->a[side] = y;
+			x->a[!side] = node;
+			node->h = height_y + 1;
+			x->h = height_y + 2;
+			y = x;
+
+		}
+		*nodep = y;
+		return y->h - height_node;
+	}
+
+	int balance_tree(struct node **nodep) {
+		struct node *node = *nodep;
+		int height_a = height(static_cast<struct node *>(node->a[0]));
+		int height_b = height(static_cast<struct node *>(node->a[1]));
+		if (height_a - height_b < 2) {
+			int old = node->h;
+			node->h = height_a < height_b ? height_b + 1 : height_a + 1;
+			return node->h - old;
+		}
+
+		return rotate(nodep, height_a < height_b);
+	}
+}
+
+void *tsearch(const void *key, void **rootp, int(*compar)(const void *, const void *)) {
+	if (!rootp)
+		return NULL;
+
+	struct node *n = static_cast<struct node *>(*rootp);
+	frg::stack<struct node **, MemoryAllocator> nodes(getAllocator());
+	nodes.push(reinterpret_cast<struct node **>(rootp));
+	int c = 0;
+	for (;;) {
+		if (!n)
+			break;
+		c = compar(key, n->key);
+		if (!c)
+			return n;
+		nodes.push(reinterpret_cast<struct node **>(&n->a[c > 0]));
+		n = static_cast<struct node *>(n->a[c > 0]);
+	}
+
+	struct node *insert = static_cast<struct node*>(malloc(sizeof(struct node)));
+	if (!insert)
+		return NULL;
+	insert->key = key;
+	insert->a[0] = insert->a[1] = NULL;
+	insert->h = 1;
+
+	(*nodes.top()) = insert;
+	nodes.pop();
+	while(nodes.size() && balance_tree(nodes.top())) nodes.pop();
+	return insert;
+}
+
+// This implementation is taken from musl
+void *tfind(const void *key, void *const *rootp, int (*compar)(const void *, const void *)) {
+	if(!rootp)
+		return 0;
+
+	struct node *n = (struct node *)*rootp;
+	for(;;) {
+		if(!n)
+			break;
+		int c = compar(key, n->key);
+		if(!c)
+			break;
+		n = (struct node *)n->a[c > 0];
+	}
+	return n;
+}
+
+void *tdelete(const void *, void **, int(*compar)(const void *, const void *)) {
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void twalk(const void *, void (*action)(const void *, VISIT, int)) {
+	(void)action;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void tdestroy(void *, void (*free_node)(void *)) {
+	(void)free_node;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *lsearch(const void *key, void *base, size_t *nelp, size_t width,
+		int (*compar)(const void *, const void *)) {
+	(void)key;
+	(void)base;
+	(void)nelp;
+	(void)width;
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *lfind(const void *key, const void *base, size_t *nelp,
+		size_t width, int (*compar)(const void *, const void *)) {
+	(void)key;
+	(void)base;
+	(void)nelp;
+	(void)width;
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/semaphore-stubs.cpp b/lib/mlibc/options/posix/generic/semaphore-stubs.cpp
new file mode 100644
index 0000000..d41eccb
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/semaphore-stubs.cpp
@@ -0,0 +1,114 @@
+#include <semaphore.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+static constexpr unsigned int semaphoreHasWaiters = static_cast<uint32_t>(1 << 31);
+static constexpr unsigned int semaphoreCountMask = static_cast<uint32_t>(1 << 31) - 1;
+
+int sem_init(sem_t *sem, int pshared, unsigned int initial_count) {
+	if (pshared) {
+		mlibc::infoLogger() << "mlibc: shared semaphores are unsuppored" << frg::endlog;
+		errno = ENOSYS;
+		return -1;
+	}
+
+	if (initial_count > SEM_VALUE_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	sem->__mlibc_count = initial_count;
+
+	return 0;
+}
+
+int sem_destroy(sem_t *) {
+	return 0;
+}
+
+int sem_wait(sem_t *sem) {
+	unsigned int state = 0;
+
+	while (1) {
+		if (!(state & semaphoreCountMask)) {
+			if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, semaphoreHasWaiters,
+						false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) {
+				int e = mlibc::sys_futex_wait((int *)&sem->__mlibc_count, state, nullptr);
+				if (e == 0 || e == EAGAIN) {
+					continue;
+				} else if (e == EINTR) {
+					errno = EINTR;
+					return -1;
+				} else {
+					mlibc::panicLogger() << "sys_futex_wait() failed with error code " << e << frg::endlog;
+				}
+			}
+		} else {
+			unsigned int desired = (state - 1);
+			if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, desired, false,
+						__ATOMIC_RELAXED, __ATOMIC_RELAXED))
+				return 0;
+		}
+	}
+}
+
+int sem_timedwait(sem_t *sem, const struct timespec *) {
+	mlibc::infoLogger() << "\e[31mmlibc: sem_timedwait is implemented as sem_wait\e[0m" << frg::endlog;
+	return sem_wait(sem);
+}
+
+int sem_post(sem_t *sem) {
+	auto old_count = __atomic_load_n(&sem->__mlibc_count, __ATOMIC_RELAXED) & semaphoreCountMask;
+
+	if (old_count + 1 > SEM_VALUE_MAX) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+
+	auto state = __atomic_exchange_n(&sem->__mlibc_count, old_count + 1, __ATOMIC_RELEASE);
+
+	if (state & semaphoreHasWaiters)
+		if (int e = mlibc::sys_futex_wake((int *)&sem->__mlibc_count); e)
+			__ensure(!"sys_futex_wake() failed");
+
+	return 0;
+}
+
+sem_t *sem_open(const char *, int, ...) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_close(sem_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_getvalue(sem_t *, int *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_unlink(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_trywait(sem_t *sem) {
+	while (true) {
+		auto state = __atomic_load_n(&sem->__mlibc_count, __ATOMIC_ACQUIRE);
+
+		if (state & semaphoreHasWaiters) {
+			return EAGAIN;
+		}
+
+		auto desired = state - 1;
+		if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED)) {
+			return 0;
+		}
+	}
+}
diff --git a/lib/mlibc/options/posix/generic/services.cpp b/lib/mlibc/options/posix/generic/services.cpp
new file mode 100644
index 0000000..8ae0656
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/services.cpp
@@ -0,0 +1,222 @@
+#include <mlibc/services.hpp>
+#include <netdb.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <mlibc/debug.hpp>
+
+namespace mlibc {
+
+static int parse_rest(service_buf &buf, char *end, int proto) {
+	if (!strncmp(end, "/udp", 4)) {
+		if (proto == IPPROTO_TCP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_UDP;
+		buf.socktype = SOCK_DGRAM;
+	} else if (!strncmp(end, "/tcp", 4)) {
+		if (proto == IPPROTO_UDP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_TCP;
+		buf.socktype = SOCK_STREAM;
+	} else {
+		return 0;
+	}
+
+	//TODO(geert): also parse aliases.
+
+	return 1;
+}
+
+static int lookup_serv_file_port(service_result &buf, int proto, int port) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line_buf[129] = {0};
+	char *line = line_buf + 1;
+	while(fgets(line, 128, file)) {
+		int name_length = 0;
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		char *end = NULL;
+		for (pos = line; *pos; pos++) {
+			for (; isalpha(*pos); pos++);
+			int rport = strtoul(pos, &end, 10);
+			if (rport != port || rport > 65535) {
+				pos = end;
+				continue;
+			}
+
+			// We have found the port, time to rewind to the start
+			// of the line.
+			for (; pos[-1]; pos--)
+				if(!isspace(pos[-1]))
+					name_length++;
+			break;
+		}
+
+		if (!pos)
+			continue;
+
+		if (!name_length)
+			continue;
+
+		auto name = frg::string<MemoryAllocator>(pos, name_length,
+				getAllocator());
+
+		struct service_buf sbuf = {};
+		sbuf.port = port;
+		sbuf.name = std::move(name);
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+		buf.push_back(std::move(sbuf));
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+static int lookup_serv_file_name(service_result &buf, const char *name,
+		int proto) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line[128];
+	int name_length = strlen(name);
+	while(fgets(line, 128, file)) {
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		for (pos = line; (pos = strstr(pos, name)); pos++) {
+			// the name must start and end with a space
+			if (pos > line && !isspace(pos[-1]))
+				continue;
+			if (pos[name_length] && !isspace(pos[name_length]))
+				continue;
+			break;
+		}
+		if (!pos)
+			continue;
+
+		// Skip the name at the beginning of the line.
+		for(pos = line; *pos && !isspace(*pos); pos++)
+			;
+
+		char *end = NULL;
+		int port = strtoul(pos, &end, 10);
+		if (port > 65535 || end == pos)
+			continue;
+
+		struct service_buf sbuf;
+		sbuf.port = port;
+		sbuf.name = frg::string<MemoryAllocator>(name, getAllocator());
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+
+		buf.push_back(sbuf);
+
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+
+// This function returns a negative error code, since a positive
+// return code means success.
+int lookup_serv_by_name(service_result &buf, const char *name, int proto,
+		int socktype, int flags) {
+	switch(socktype) {
+		case SOCK_STREAM:
+			if (!proto)
+				proto = IPPROTO_TCP;
+			else if (proto != IPPROTO_TCP)
+				return -EAI_SERVICE;
+			break;
+		case SOCK_DGRAM:
+			if (!proto)
+				proto = IPPROTO_UDP;
+			else if (proto != IPPROTO_UDP)
+				return -EAI_SERVICE;
+			break;
+		case 0:
+			break;
+		default:
+			if (name)
+				return -EAI_SERVICE;
+			buf[0].port = 0;
+			buf[0].socktype = socktype;
+			buf[0].protocol = proto;
+			return 1;
+	}
+
+	char *end = nullptr;
+	unsigned int port = 0;
+	int count = 0;
+
+	if (name) {
+		if (!*name)
+			return -EAI_SERVICE;
+		port = strtoul(name, &end, 10);
+	}
+	// The end pointer is a null pointer so the name was a port
+	// or the name was not specified.
+	if (!end || !*end) {
+		if (proto != IPPROTO_UDP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_TCP;
+			buf[count].socktype = SOCK_STREAM;
+			count++;
+		}
+		if (proto != IPPROTO_TCP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_UDP;
+			buf[count].socktype = SOCK_DGRAM;
+			count++;
+		}
+		return count;
+	}
+
+	if (flags & AI_NUMERICSERV)
+		return -EAI_NONAME;
+
+	return lookup_serv_file_name(buf, name, proto);
+}
+
+int lookup_serv_by_port(service_result &buf, int proto, int port) {
+	return lookup_serv_file_port(buf, proto, port);
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/spawn-stubs.cpp b/lib/mlibc/options/posix/generic/spawn-stubs.cpp
new file mode 100644
index 0000000..cf7edfc
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/spawn-stubs.cpp
@@ -0,0 +1,376 @@
+
+#include <spawn.h>
+#include <errno.h>
+#include <pthread.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+/*
+ * Musl places this in a seperate header called fdop.h
+ * This header isn't present in glibc, or on my host, so I
+ * include it's contents here
+ */
+
+#define FDOP_CLOSE 1
+#define FDOP_DUP2 2
+#define FDOP_OPEN 3
+#define FDOP_CHDIR 4
+#define FDOP_FCHDIR 5
+
+struct fdop {
+	struct fdop *next, *prev;
+	int cmd, fd, srcfd, oflag;
+	mode_t mode;
+	char path[];
+};
+
+/*
+ * This posix_spawn implementation is taken from musl
+ */
+
+static unsigned long handler_set[NSIG / (8 * sizeof(long))];
+
+static void __get_handler_set(sigset_t *set) {
+	memcpy(set, handler_set, sizeof handler_set);
+}
+
+struct args {
+	int p[2];
+	sigset_t oldmask;
+	const char *path;
+	const posix_spawn_file_actions_t *fa;
+	const posix_spawnattr_t *__restrict attr;
+	char *const *argv, *const *envp;
+};
+
+static int child(void *args_vp) {
+	int i, ret;
+	struct sigaction sa = {};
+	struct args *args = (struct args *)args_vp;
+	int p = args->p[1];
+	const posix_spawn_file_actions_t *fa = args->fa;
+	const posix_spawnattr_t *__restrict attr = args->attr;
+	sigset_t hset;
+	bool use_execvpe = false;
+
+	if(attr->__fn)
+		use_execvpe = true;
+
+	close(args->p[0]);
+
+	/* All signal dispositions must be either SIG_DFL or SIG_IGN
+	 * before signals are unblocked. Otherwise a signal handler
+	 * from the parent might get run in the child while sharing
+	 * memory, with unpredictable and dangerous results. To
+	 * reduce overhead, sigaction has tracked for us which signals
+	 * potentially have a signal handler. */
+	__get_handler_set(&hset);
+	for(i = 1; i < NSIG; i++) {
+		if((attr->__flags & POSIX_SPAWN_SETSIGDEF) && sigismember(&attr->__def, i)) {
+			sa.sa_handler = SIG_DFL;
+		} else if(sigismember(&hset, i)) {
+			if (i - 32 < 3) {
+				sa.sa_handler = SIG_IGN;
+			} else {;
+				sigaction(i, 0, &sa);
+				if(sa.sa_handler == SIG_IGN)
+					continue;
+				sa.sa_handler = SIG_DFL;
+			}
+		} else {
+			continue;
+		}
+		sigaction(i, &sa, 0);
+	}
+
+	if(attr->__flags & POSIX_SPAWN_SETSID) {
+		if((ret = setsid()) < 0)
+			goto fail;
+	}
+
+	if(attr->__flags & POSIX_SPAWN_SETPGROUP) {
+		mlibc::infoLogger() << "mlibc: posix_spawn: ignoring SETPGROUP" << frg::endlog;
+		//if((ret = setpgid(0, attr->__pgrp)))
+		//	goto fail;
+	}
+
+	if(attr->__flags & POSIX_SPAWN_RESETIDS) {
+		if((ret = setgid(getgid())) || (ret = setuid(getuid())) )
+			goto fail;
+	}
+
+	if(fa && fa->__actions) {
+		struct fdop *op;
+		int fd;
+		for(op = (struct fdop *)fa->__actions; op->next; op = op->next);
+		for(; op; op = op->prev) {
+			/* It's possible that a file operation would clobber
+			 * the pipe fd used for synchronizing with the
+			 * parent. To avoid that, we dup the pipe onto
+			 * an unoccupied fd. */
+			if(op->fd == p) {
+				ret = dup(p);
+				if(ret < 0)
+					goto fail;
+				close(p);
+				p = ret;
+			}
+			switch(op->cmd) {
+			case FDOP_CLOSE:
+				close(op->fd);
+				break;
+			case FDOP_DUP2:
+				fd = op->srcfd;
+				if(fd == p) {
+					ret = -EBADF;
+					goto fail;
+				}
+				if(fd != op->fd) {
+					if((ret = dup2(fd, op->fd)) < 0)
+						goto fail;
+				} else {
+					ret = fcntl(fd, F_GETFD);
+					ret = fcntl(fd, F_SETFD, ret & ~FD_CLOEXEC);
+					if(ret < 0)
+						goto fail;
+				}
+				break;
+			case FDOP_OPEN:
+				fd = open(op->path, op->oflag, op->mode);
+				if((ret = fd) < 0)
+					goto fail;
+				if(fd != op->fd) {
+					if((ret = dup2(fd, op->fd)) < 0)
+						goto fail;
+					close(fd);
+				}
+				break;
+			case FDOP_CHDIR:
+				ret = chdir(op->path);
+				if(ret < 0)
+					goto fail;
+				break;
+			case FDOP_FCHDIR:
+				ret = fchdir(op->fd);
+				if(ret < 0)
+					goto fail;
+				break;
+			}
+		}
+	}
+
+	/* Close-on-exec flag may have been lost if we moved the pipe
+	 * to a different fd. */
+	fcntl(p, F_SETFD, FD_CLOEXEC);
+
+	pthread_sigmask(SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
+		? &attr->__mask : &args->oldmask, 0);
+
+	if(use_execvpe)
+		execvpe(args->path, args->argv, args->envp);
+	else
+		execve(args->path, args->argv, args->envp);
+	ret = -errno;
+
+fail:
+	/* Since sizeof errno < PIPE_BUF, the write is atomic. */
+	ret = -ret;
+	if(ret)
+		while(write(p, &ret, sizeof ret) < 0);
+	_exit(127);
+}
+
+int posix_spawn(pid_t *__restrict res, const char *__restrict path,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrs,
+		char *const argv[], char *const envp[]) {
+	pid_t pid;
+	int ec = 0, cs;
+	struct args args;
+	const posix_spawnattr_t empty_attr = {};
+	sigset_t full_sigset;
+	sigfillset(&full_sigset);
+
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
+	args.path = path;
+	args.fa = file_actions;
+	args.attr = attrs ? attrs : &empty_attr;
+	args.argv = argv;
+	args.envp = envp;
+	pthread_sigmask(SIG_BLOCK, &full_sigset, &args.oldmask);
+
+	/* The lock guards both against seeing a SIGABRT disposition change
+	 * by abort and against leaking the pipe fd to fork-without-exec. */
+	//LOCK(__abort_lock);
+
+	if(pipe2(args.p, O_CLOEXEC)) {
+		//UNLOCK(__abort_lock);
+		ec = errno;
+		goto fail;
+	}
+
+	/* Mlibc change: We use fork + execve, as clone is not implemented.
+	 * This yields the same result in the end. */
+	//pid = clone(child, stack + sizeof stack, CLONE_VM | CLONE_VFORK | SIGCHLD, &args);
+	pid = fork();
+	if(!pid) {
+		child(&args);
+	}
+	close(args.p[1]);
+	//UNLOCK(__abort_lock);
+
+	if(pid > 0) {
+		if(read(args.p[0], &ec, sizeof ec) != sizeof ec)
+			ec = 0;
+		else
+			waitpid(pid, 0, 0);
+	} else {
+		ec = -pid;
+	}
+
+	close(args.p[0]);
+
+	if(!ec && res)
+		*res = pid;
+
+fail:
+	pthread_sigmask(SIG_SETMASK, &args.oldmask, 0);
+	pthread_setcancelstate(cs, 0);
+
+	return ec;
+}
+
+int posix_spawnattr_init(posix_spawnattr_t *attr) {
+	*attr = (posix_spawnattr_t){};
+	return 0;
+}
+
+int posix_spawnattr_destroy(posix_spawnattr_t *) {
+	return 0;
+}
+
+int posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags) {
+	const unsigned all_flags = 
+			POSIX_SPAWN_RESETIDS |
+			POSIX_SPAWN_SETPGROUP |
+			POSIX_SPAWN_SETSIGDEF |
+			POSIX_SPAWN_SETSIGMASK |
+			POSIX_SPAWN_SETSCHEDPARAM |
+			POSIX_SPAWN_SETSCHEDULER |
+			POSIX_SPAWN_USEVFORK |
+			POSIX_SPAWN_SETSID;
+	if(flags & ~all_flags)
+		return EINVAL;
+	attr->__flags = flags;
+	return 0;
+}
+
+int posix_spawnattr_setsigdefault(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigdefault) {
+	attr->__def = *sigdefault;
+	return 0;
+}
+
+int posix_spawnattr_setschedparam(posix_spawnattr_t *__restrict,
+		const struct sched_param *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int posix_spawnattr_setschedpolicy(posix_spawnattr_t *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int posix_spawnattr_setsigmask(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigmask) {
+	attr->__mask = *sigmask;
+	return 0;
+}
+
+int posix_spawnattr_setpgroup(posix_spawnattr_t *attr, pid_t pgroup) {
+	attr->__pgrp = pgroup;
+	return 0;
+}
+
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t *file_actions) {
+	file_actions->__actions = 0;
+	return 0;
+}
+
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *file_actions) {
+	struct fdop *op = (struct fdop *)file_actions->__actions, *next;
+	while(op) {
+		next = op->next;
+		free(op);
+		op = next;
+	}
+	return 0;
+}
+
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions,
+		int fildes, int newfildes) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_DUP2;
+	op->srcfd = fildes;
+	op->fd = newfildes;
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
+		int fildes) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_CLOSE;
+	op->fd = fildes;
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *__restrict file_actions,
+		int fildes, const char *__restrict path, int oflag, mode_t mode) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op + strlen(path) + 1);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_OPEN;
+	op->fd = fildes;
+	op->oflag = oflag;
+	op->mode = mode;
+	strcpy(op->path, path);
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawnp(pid_t *__restrict pid, const char *__restrict file,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrp,
+		char *const argv[], char *const envp[]) {
+	posix_spawnattr_t spawnp_attr = {};
+	if(attrp)
+		spawnp_attr = *attrp;
+	spawnp_attr.__fn = (void *)execvpe;	
+	return posix_spawn(pid, file, file_actions, &spawnp_attr, argv, envp);
+}
+
diff --git a/lib/mlibc/options/posix/generic/strings-stubs.cpp b/lib/mlibc/options/posix/generic/strings-stubs.cpp
new file mode 100644
index 0000000..524c424
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/strings-stubs.cpp
@@ -0,0 +1,107 @@
+
+#include <strings.h>
+#include <string.h>
+
+#include <ctype.h>
+#include <bits/ensure.h>
+#include <mlibc/strings.hpp>
+
+char *index (const char *s, int c) {
+	return strchr(s, c);
+}
+
+char *rindex(const char *s, int c) {
+	return strrchr(s, c);
+}
+
+namespace {
+
+	template<typename T>
+	int ffs_generic(T i) {
+		//Non-portably assume a byte has 8 bits; fine in all plausible cases.
+		for(size_t b = 0; b < sizeof(T) * 8;)
+			if(i & (static_cast<T>(0x1) << b++))
+				return b;
+
+		return 0;
+	}
+
+}
+
+// On RISC-V, __builtin_ffs just calls into ffs, so we can't use it here.
+#if defined(__has_builtin) && !defined(__riscv)
+#	if __has_builtin(__builtin_ffs)
+#		define __mlibc_ffs __builtin_ffs
+#	endif
+#	if __has_builtin(__builtin_ffsl)
+#		define __mlibc_ffsl __builtin_ffsl
+#	endif
+#	if __has_builtin(__builtin_ffsll)
+#		define __mlibc_ffsll __builtin_ffsll
+#	endif
+#endif
+
+int ffs(int i) {
+#ifdef __mlibc_ffs
+	return __mlibc_ffs(i);
+#else
+	return ffs_generic<int>(i);
+#endif
+}
+
+/*
+	Both ffsl() and ffsll() are glibc extensions
+	defined in string.h. They are however implemented
+	here because of similarity in logic and
+	shared code.
+*/
+
+int ffsl(long i) {
+#ifdef __mlibc_ffsl
+	return __mlibc_ffsl(i);
+#else
+	return ffs_generic<long>(i);
+#endif
+}
+
+int ffsll(long long i) {
+#ifdef __mlibc_ffsll
+	return __mlibc_ffsll(i);
+#else
+	return ffs_generic<long long>(i);
+#endif
+}
+
+int strcasecmp(const char *a, const char *b) {
+	size_t i = 0;
+	while(true) {
+		unsigned char a_byte = tolower(a[i]);
+		unsigned char b_byte = tolower(b[i]);
+		if(!a_byte && !b_byte)
+			return 0;
+		// If only one char is null, one of the following cases applies.
+		if(a_byte < b_byte)
+			return -1;
+		if(a_byte > b_byte)
+			return 1;
+		i++;
+	}
+}
+
+int strncasecmp(const char *a, const char *b, size_t size) {
+	return mlibc::strncasecmp(a, b, size);
+}
+
+// Marked as obsolete in posix 2008 but used by at least tracker
+int bcmp(const void *s1, const void *s2, size_t n) {
+	return memcmp(s1, s2, n);
+}
+
+void bcopy(const void *s1, void *s2, size_t n) {
+	memmove(s2, s1, n);
+}
+
+void bzero(void *s, size_t n) {
+	memset(s, 0, n);
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-file-stubs.cpp b/lib/mlibc/options/posix/generic/sys-file-stubs.cpp
new file mode 100644
index 0000000..e1cc9ab
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-file-stubs.cpp
@@ -0,0 +1,16 @@
+
+#include <sys/file.h>
+#include <mlibc/posix-sysdeps.hpp>
+#include <errno.h>
+
+#include <bits/ensure.h>
+
+int flock(int fd, int opt) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_flock, -1);
+	if(int e = mlibc::sys_flock(fd, opt); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-ipc.cpp b/lib/mlibc/options/posix/generic/sys-ipc.cpp
new file mode 100644
index 0000000..b9e0d3d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-ipc.cpp
@@ -0,0 +1,8 @@
+#include <sys/ipc.h>
+
+#include <bits/ensure.h>
+
+key_t ftok(const char *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp b/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp
new file mode 100644
index 0000000..9383976
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp
@@ -0,0 +1,177 @@
+
+#include <errno.h>
+#include <limits.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int mprotect(void *pointer, size_t size, int prot) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_vm_protect, -1);
+	if(int e = mlibc::sys_vm_protect(pointer, size, prot); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mlock(const void *addr, size_t len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mlock, -1);
+	if(int e = mlibc::sys_mlock(addr, len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mlockall(int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mlockall, -1);
+	if(int e = mlibc::sys_mlockall(flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int munlock(const void *addr, size_t len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlock, -1);
+	if(int e = mlibc::sys_munlock(addr, len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int munlockall(void) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlockall, -1);
+	if(int e = mlibc::sys_munlockall(); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+
+int posix_madvise(void *, size_t, int) {
+	mlibc::infoLogger() << "\e[31m" "mlibc: posix_madvise() fails unconditionally" "\e[39m"
+			<< frg::endlog;
+	return ENOSYS;
+}
+
+int msync(void *addr, size_t length, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msync, -1);
+	if(int e = mlibc::sys_msync(addr, length, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void *mremap(void *pointer, size_t size, size_t new_size, int flags, ...) {
+	__ensure(flags == MREMAP_MAYMOVE);
+
+	void *window;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_vm_remap, (void *)-1);
+	if(int e = mlibc::sys_vm_remap(pointer, size, new_size, &window); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return window;
+}
+
+int remap_file_pages(void *, size_t, int, size_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *mmap(void *hint, size_t size, int prot, int flags, int fd, off_t offset) {
+	void *window;
+	if(int e = mlibc::sys_vm_map(hint, size, prot, flags, fd, offset, &window); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return window;
+}
+
+int munmap(void *pointer, size_t size) {
+	if(int e = mlibc::sys_vm_unmap(pointer, size); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// The implementation of shm_open and shm_unlink is taken from musl.
+namespace {
+	char *shm_mapname(const char *name, char *buf) {
+		char *p;
+		while(*name == '/')
+			name++;
+		if(*(p = strchrnul(name, '/')) || p == name ||
+			(p - name <= 2 && name[0] == '.' && p[-1] == '.')) {
+			errno = EINVAL;
+			return 0;
+		}
+		if(p - name > NAME_MAX) {
+			errno = ENAMETOOLONG;
+			return 0;
+		}
+		memcpy(buf, "/dev/shm/", 9);
+		memcpy(buf + 9, name, p - name + 1);
+		return buf;
+	}
+}
+
+int shm_open(const char *name, int flags, mode_t mode) {
+	int cs;
+	char buf[NAME_MAX + 10];
+	if(!(name = shm_mapname(name, buf)))
+		return -1;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	int fd = open(name, flags | O_NOFOLLOW | O_CLOEXEC | O_NONBLOCK, mode);
+	pthread_setcancelstate(cs, 0);
+	return fd;
+}
+
+int shm_unlink(const char *name) {
+	char buf[NAME_MAX + 10];
+	if(!(name = shm_mapname(name, buf)))
+		return -1;
+	return unlink(name);
+}
+
+#if __MLIBC_LINUX_OPTION
+int memfd_create(const char *name, unsigned int flags) {
+	int ret = -1;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_memfd_create, -1);
+	if(int e = mlibc::sys_memfd_create(name, flags, &ret)) {
+		errno = e;
+		return -1;
+	}
+
+	return ret;
+}
+
+int madvise(void *addr, size_t length, int advice) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_madvise, -1);
+	if(int e = mlibc::sys_madvise(addr, length, advice)) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mincore(void *addr, size_t length, unsigned char *vec) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlockall, -1);
+	if(int e = mlibc::sys_mincore(addr, length, vec); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+#endif /* __MLIBC_LINUX_OPTION */
diff --git a/lib/mlibc/options/posix/generic/sys-msg.cpp b/lib/mlibc/options/posix/generic/sys-msg.cpp
new file mode 100644
index 0000000..95f067e
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-msg.cpp
@@ -0,0 +1,23 @@
+
+#include <bits/ensure.h>
+#include <sys/msg.h>
+
+int msgget(key_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int msgctl(int, int, struct msqid_ds *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t msgrcv(int, void *, size_t, long, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int msgsnd(int, const void *, size_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp b/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp
new file mode 100644
index 0000000..597de4d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp
@@ -0,0 +1,57 @@
+
+#include <errno.h>
+#include <sys/resource.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int getpriority(int which, id_t who) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getpriority, -1);
+	int value = 0;
+	if(int e = mlibc::sys_getpriority(which, who, &value); e) {
+		errno = e;
+	}
+	return value;
+}
+
+int setpriority(int which, id_t who, int prio) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setpriority, -1);
+	if(int e = mlibc::sys_setpriority(which, who, prio); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getrusage(int scope, struct rusage *usage) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getrusage, -1);
+	if(int e = mlibc::sys_getrusage(scope, usage); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getrlimit(int resource, struct rlimit *limit) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getrlimit, -1);
+	if(int e = mlibc::sys_getrlimit(resource, limit); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setrlimit(int resource, const struct rlimit *limit) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setrlimit, -1);
+	if(int e = mlibc::sys_setrlimit(resource, limit); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int prlimit(pid_t, int, const struct rlimit *, struct rlimit *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-select-stubs.cpp b/lib/mlibc/options/posix/generic/sys-select-stubs.cpp
new file mode 100644
index 0000000..e8ff927
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-select-stubs.cpp
@@ -0,0 +1,58 @@
+
+#include <string.h>
+#include <sys/select.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc-config.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+
+void __FD_CLR(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	set->__mlibc_elems[fd / 8] &= ~(1 << (fd % 8));
+}
+int __FD_ISSET(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	return set->__mlibc_elems[fd / 8] & (1 << (fd % 8));
+}
+void __FD_SET(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	set->__mlibc_elems[fd / 8] |= 1 << (fd % 8);
+}
+void __FD_ZERO(fd_set *set) {
+	memset(set->__mlibc_elems, 0, sizeof(fd_set));
+}
+
+int select(int num_fds, fd_set *__restrict read_set, fd_set *__restrict write_set,
+		fd_set *__restrict except_set, struct timeval *__restrict timeout) {
+	int num_events = 0;
+	struct timespec timeouts = {};
+	struct timespec *timeout_ptr = NULL;
+	if (timeout) {
+		timeouts.tv_sec = timeout->tv_sec;
+		timeouts.tv_nsec = timeout->tv_usec * 1000;
+		timeout_ptr = &timeouts;
+	}
+
+    MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pselect, -1);
+	if(int e = mlibc::sys_pselect(num_fds, read_set, write_set, except_set,
+				timeout_ptr, NULL, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
+
+int pselect(int num_fds, fd_set *read_set, fd_set *write_set, fd_set *except_set,
+		const struct timespec *timeout,	const sigset_t *sigmask) {
+	int num_events = 0;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pselect, -1);
+	if(int e = mlibc::sys_pselect(num_fds, read_set, write_set, except_set,
+				timeout, sigmask, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-sem.cpp b/lib/mlibc/options/posix/generic/sys-sem.cpp
new file mode 100644
index 0000000..ac3df69
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-sem.cpp
@@ -0,0 +1,51 @@
+
+#include <bits/ensure.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/sem.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+
+int semget(key_t key, int n, int fl) {
+	if(n > USHRT_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	int id = 0;
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_semget, -1);
+	if(int e = sysdep(key, n, fl, &id); e) {
+		errno = e;
+		return -1;
+	}
+	return id;
+}
+
+int semop(int, struct sembuf *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+};
+
+int semctl(int id, int num, int cmd, ...) {
+	union semun semun;
+	int ret = 0;
+
+	va_list ap;
+	va_start(ap, cmd);
+	semun = va_arg(ap, union semun);
+	va_end(ap);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_semctl, -1);
+	if(int e = sysdep(id, num, cmd, semun.buf, &ret); e) {
+		errno = e;
+		return -1;
+	}
+
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-shm.cpp b/lib/mlibc/options/posix/generic/sys-shm.cpp
new file mode 100644
index 0000000..3af7e90
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-shm.cpp
@@ -0,0 +1,24 @@
+#include <sys/shm.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+void *shmat(int, const void *, int) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmctl(int, int, struct shmid_ds *) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmdt(const void *) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmget(key_t, size_t, int) {
+	mlibc::infoLogger() << "mlibc: shmget() is a no-op!" << frg::endlog;
+	return -1;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp b/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp
new file mode 100644
index 0000000..037a994
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp
@@ -0,0 +1,225 @@
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/socket.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int accept(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_accept, -1);
+	if(int e = mlibc::sys_accept(fd, &newfd, addr_ptr, addr_length, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+int accept4(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length, int flags) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_accept, -1);
+	if(int e = mlibc::sys_accept(fd, &newfd, addr_ptr, addr_length, flags); e) {
+		errno = e;
+		return -1;
+	}
+
+	return newfd;
+}
+
+int bind(int fd, const struct sockaddr *addr_ptr, socklen_t addr_len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_bind, -1);
+	if(int e = mlibc::sys_bind(fd, addr_ptr, addr_len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int connect(int fd, const struct sockaddr *addr_ptr, socklen_t addr_len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_connect, -1);
+	if(int e = mlibc::sys_connect(fd, addr_ptr, addr_len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getpeername(int fd, struct sockaddr *addr_ptr, socklen_t *__restrict addr_length) {
+	socklen_t actual_length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_peername, -1);
+	if(int e = mlibc::sys_peername(fd, addr_ptr, *addr_length, &actual_length); e) {
+		errno = e;
+		return -1;
+	}
+	*addr_length = actual_length;
+	return 0;
+}
+
+int getsockname(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length) {
+	socklen_t actual_length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sockname, -1);
+	if(int e = mlibc::sys_sockname(fd, addr_ptr, *addr_length, &actual_length); e) {
+		errno = e;
+		return -1;
+	}
+	*addr_length = actual_length;
+	return 0;
+}
+
+int getsockopt(int fd, int layer, int number,
+		void *__restrict buffer, socklen_t *__restrict size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getsockopt, -1);
+	return mlibc::sys_getsockopt(fd, layer, number, buffer, size);
+}
+
+int listen(int fd, int backlog) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_listen, -1);
+	if(int e = mlibc::sys_listen(fd, backlog); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t recv(int sockfd, void *__restrict buf, size_t len, int flags) {
+	return recvfrom(sockfd, buf, len, flags, NULL, NULL);
+}
+
+ssize_t recvfrom(int sockfd, void *__restrict buf, size_t len, int flags,
+		struct sockaddr *__restrict src_addr, socklen_t *__restrict addrlen) {
+	if(mlibc::sys_recvfrom) {
+		ssize_t length;
+		if(int e = mlibc::sys_recvfrom(sockfd, buf, len, flags, src_addr, addrlen, &length); e) {
+			errno = e;
+			return -1;
+		}
+		return length;
+	}
+
+	struct iovec iov = {};
+	iov.iov_base = buf;
+	iov.iov_len = len;
+
+	struct msghdr hdr = {};
+	hdr.msg_name = src_addr;
+	if (addrlen) {
+		hdr.msg_namelen = *addrlen;
+	}
+	hdr.msg_iov = &iov;
+	hdr.msg_iovlen = 1;
+
+	int ret = recvmsg(sockfd, &hdr, flags);
+	if (ret < 0)
+		return ret;
+
+	if(addrlen)
+		*addrlen = hdr.msg_namelen;
+	return ret;
+}
+
+ssize_t recvmsg(int fd, struct msghdr *hdr, int flags) {
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msg_recv, -1);
+	if(int e = mlibc::sys_msg_recv(fd, hdr, flags, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+int recvmmsg(int, struct mmsghdr *, unsigned int, int, struct timespec *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t send(int fd, const void *buffer, size_t size, int flags) {
+	return sendto(fd, buffer, size, flags, nullptr, 0);
+}
+
+ssize_t sendto(int fd, const void *buffer, size_t size, int flags,
+		const struct sockaddr *sock_addr, socklen_t addr_length) {
+	if(mlibc::sys_sendto) {
+		ssize_t length;
+		if(int e = mlibc::sys_sendto(fd, buffer, size, flags, sock_addr, addr_length, &length); e) {
+			errno = e;
+			return -1;
+		}
+		return length;
+	}
+
+	struct iovec iov = {};
+	iov.iov_base = const_cast<void *>(buffer);
+	iov.iov_len = size;
+
+	struct msghdr hdr = {};
+	hdr.msg_name = const_cast<struct sockaddr *>(sock_addr);
+	hdr.msg_namelen = addr_length;
+	hdr.msg_iov = &iov;
+	hdr.msg_iovlen = 1;
+
+	return sendmsg(fd, &hdr, flags);
+}
+
+ssize_t sendmsg(int fd, const struct msghdr *hdr, int flags) {
+	if(hdr->msg_iovlen > IOV_MAX)
+		return EMSGSIZE;
+
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msg_send, -1);
+	if(int e = mlibc::sys_msg_send(fd, hdr, flags, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+int sendmmsg(int, struct mmsghdr *, unsigned int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int setsockopt(int fd, int layer, int number,
+		const void *buffer, socklen_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setsockopt, -1);
+	return mlibc::sys_setsockopt(fd, layer, number, buffer, size);
+}
+
+int shutdown(int sockfd, int how) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_shutdown, -1);
+	if(int e = sysdep(sockfd, how); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int sockatmark(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int socket(int family, int type, int protocol) {
+	int fd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_socket, -1);
+	if(int e = mlibc::sys_socket(family, type, protocol, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	return fd;
+}
+
+int socketpair(int domain, int type, int protocol, int sv[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_socketpair, -1);
+	if(int e = mlibc::sys_socketpair(domain, type, protocol, sv); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// connectpair() is provided by the platform
+
diff --git a/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp b/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp
new file mode 100644
index 0000000..2eca445
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp
@@ -0,0 +1,155 @@
+
+#include <errno.h>
+#include <bits/ensure.h>
+#include <sys/stat.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int chmod(const char *pathname, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chmod, -1);
+	if(int e = mlibc::sys_chmod(pathname, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchmod(int fd, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchmod, -1);
+	if(int e = mlibc::sys_fchmod(fd, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchmodat, -1);
+	if(int e = mlibc::sys_fchmodat(dirfd, pathname, mode, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstatat(int dirfd, const char *path, struct stat *result, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::fd_path, dirfd, path, flags, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int futimens(int fd, const struct timespec times[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+
+	if (int e = mlibc::sys_utimensat(fd, nullptr, times, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mkdir(const char *path, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkdir, -1);
+	if(int e = mlibc::sys_mkdir(path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mkdirat(int dirfd, const char *path, mode_t mode) {
+	mlibc::infoLogger() << "\e[31mmlibc: mkdirat() ignores its mode\e[39m" << frg::endlog;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkdirat, -1);
+	if(int e = mlibc::sys_mkdirat(dirfd, path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mkfifo(const char *path, mode_t mode) {
+	return mkfifoat(AT_FDCWD, path, mode);
+}
+
+int mkfifoat(int dirfd, const char *path, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkfifoat, -1);
+	if (int e = mlibc::sys_mkfifoat(dirfd, path, mode); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mknod(const char *path, mode_t mode, dev_t dev) {
+	return mknodat(AT_FDCWD, path, mode, dev);
+}
+
+int mknodat(int dirfd, const char *path, mode_t mode, dev_t dev) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mknodat, -1);
+	if (int e = mlibc::sys_mknodat(dirfd, path, mode, dev); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+mode_t umask(mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_umask, -1);
+	mode_t old;
+	if (int e = mlibc::sys_umask(mode, &old); e) {
+		errno = e;
+		return -1;
+	}
+	return old;
+}
+
+int utimensat(int dirfd, const char *pathname, const struct timespec times[2], int flags) {
+	if(pathname == nullptr) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	if (int e = mlibc::sys_utimensat(dirfd, pathname, times, flags); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int stat(const char *path, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::path, -1, path, 0, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int lstat(const char *path, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::path,
+			-1, path, AT_SYMLINK_NOFOLLOW, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstat(int fd, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::fd, fd, "", 0, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp b/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp
new file mode 100644
index 0000000..c02cc39
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp
@@ -0,0 +1,24 @@
+#include <errno.h>
+#include <sys/statvfs.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int statvfs(const char *path, struct statvfs *out) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_statvfs, -1);
+	if(int e = mlibc::sys_statvfs(path, out); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstatvfs(int fd, struct statvfs *out) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fstatvfs, -1);
+	if(int e = mlibc::sys_fstatvfs(fd, out); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-time-stubs.cpp b/lib/mlibc/options/posix/generic/sys-time-stubs.cpp
new file mode 100644
index 0000000..5cc0fe5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-time-stubs.cpp
@@ -0,0 +1,107 @@
+
+#include <errno.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int gettimeofday(struct timeval *__restrict result, void *__restrict unused) {
+	(void)unused; // Linux just ignores gettimeofday().
+
+	if(result) {
+		long nanos;
+		if(int e = mlibc::sys_clock_get(CLOCK_REALTIME, &result->tv_sec, &nanos); e) {
+			errno = e;
+			return -1;
+		}
+		result->tv_usec = nanos / 1000;
+	}
+	return 0;
+}
+
+int settimeofday(const struct timeval *, const struct timezone *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void timeradd(const struct timeval *a, const struct timeval *b, struct timeval *res) {
+	res->tv_sec = a->tv_sec + b->tv_sec;
+	res->tv_usec = a->tv_usec + b->tv_usec;
+	while(res->tv_usec > 999999) {
+		res->tv_usec -= 1000000;
+		res->tv_sec += 1;
+	}
+}
+
+void timersub(const struct timeval *a, const struct timeval *b, struct timeval *res) {
+	res->tv_sec = a->tv_sec - b->tv_sec;
+	res->tv_usec = a->tv_usec - b->tv_usec;
+	while(res->tv_usec < 0) {
+		res->tv_usec += 1000000;
+		res->tv_sec -= 1;
+	}
+}
+
+void timerclear(struct timeval *tvp) {
+	tvp->tv_sec = 0;
+	tvp->tv_usec = 0;
+}
+
+int timerisset(struct timeval *tvp) {
+	if(tvp->tv_sec != 0 || tvp->tv_usec != 0) {
+		return 1;
+	}
+	return 0;
+}
+
+int getitimer(int which, struct itimerval *curr_value) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getitimer, -1);
+	if(int e = mlibc::sys_getitimer(which, curr_value); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setitimer(int which, const struct itimerval *new_value, struct itimerval *old_value) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setitimer, -1);
+	if(int e = mlibc::sys_setitimer(which, new_value, old_value); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_create(clockid_t clk, struct sigevent *__restrict evp, timer_t *__restrict res) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_create, -1);
+	if(int e = mlibc::sys_timer_create(clk, evp, res); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_settime(timer_t t, int flags, const struct itimerspec *__restrict val, struct itimerspec *__restrict old) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_settime, -1);
+	if(int e = mlibc::sys_timer_settime(t, flags, val, old); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_gettime(timer_t, struct itimerspec *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int timer_delete(timer_t t) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_delete, -1);
+	if(int e = mlibc::sys_timer_delete(t); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-times.cpp b/lib/mlibc/options/posix/generic/sys-times.cpp
new file mode 100644
index 0000000..61b6e25
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-times.cpp
@@ -0,0 +1,19 @@
+
+#include <errno.h>
+#include <sys/times.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <internal-config.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+clock_t times(struct tms *tms) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_times, -1);
+	clock_t ret;
+	if(int e = mlibc::sys_times(tms, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-uio.cpp b/lib/mlibc/options/posix/generic/sys-uio.cpp
new file mode 100644
index 0000000..0f14bc0
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-uio.cpp
@@ -0,0 +1,67 @@
+
+#include <sys/uio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#include <frg/vector.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <bits/ensure.h>
+
+ssize_t readv(int fd, const struct iovec *iovs, int iovc) {
+	ssize_t read_bytes = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_readv, -1);
+
+	if (int e = sysdep(fd, iovs, iovc, &read_bytes); e) {
+		errno = e;
+		return -1;
+	}
+
+	return read_bytes;
+}
+
+ssize_t writev(int fd, const struct iovec *iovs, int iovc) {
+	__ensure(iovc);
+
+	ssize_t written = 0;
+	size_t bytes = 0;
+	for(int i = 0; i < iovc; i++) {
+		if(SSIZE_MAX - bytes < iovs[i].iov_len) {
+			errno = EINVAL;
+			return -1;
+		}
+		bytes += iovs[i].iov_len;
+	}
+	frg::vector<char, MemoryAllocator> buffer{getAllocator()};
+	buffer.resize(bytes);
+
+	size_t to_copy = bytes;
+	char *bp = buffer.data();
+	for(int i = 0; i < iovc; i++) {
+		size_t copy = frg::min(iovs[i].iov_len, to_copy);
+
+		bp = (char *)mempcpy((void *)bp, (void *)iovs[i].iov_base, copy);
+
+		to_copy -= copy;
+		if(to_copy == 0)
+			break;
+	}
+
+	written = write(fd, buffer.data(), bytes);
+	return written;
+}
+
+ssize_t preadv(int, const struct iovec *, int, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t pwritev(int, const struct iovec *, int, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-utsname.cpp b/lib/mlibc/options/posix/generic/sys-utsname.cpp
new file mode 100644
index 0000000..3176574
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-utsname.cpp
@@ -0,0 +1,24 @@
+
+#include <string.h>
+#include <sys/utsname.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <internal-config.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int uname(struct utsname *p) {
+	if (p == NULL) {
+		errno = EFAULT;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_uname, -1);
+	if(int e = mlibc::sys_uname(p); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp b/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp
new file mode 100644
index 0000000..6e7cc78
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp
@@ -0,0 +1,52 @@
+
+#include <errno.h>
+#include <sys/wait.h>
+#include <bits/ensure.h>
+
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitid, -1);
+	if(int e = sysdep(idtype, id, info, options); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t waitpid(pid_t pid, int *status, int flags) {
+	pid_t ret;
+	int tmp_status = 0;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+	if(int e = mlibc::sys_waitpid(pid, &tmp_status, flags, NULL, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	if(status) {
+		*status = tmp_status;
+	}
+	return ret;
+}
+
+pid_t wait(int *status) {
+	return waitpid(-1, status, 0);
+}
+
+pid_t wait3(int *status, int options, struct rusage *rusage) {
+	(void) rusage;
+	mlibc::infoLogger() << "\e[31mmlibc: wait3() is not implemented correctly\e[39m"
+		<< frg::endlog;
+	return waitpid(-1, status, options);
+}
+
+pid_t wait4(pid_t pid, int *status, int options, struct rusage *ru) {
+	pid_t ret;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+	if(int e = mlibc::sys_waitpid(pid, status, options, ru, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/syslog-stubs.cpp b/lib/mlibc/options/posix/generic/syslog-stubs.cpp
new file mode 100644
index 0000000..6a80ff9
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/syslog-stubs.cpp
@@ -0,0 +1,152 @@
+
+#include <syslog.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <time.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <bits/ensure.h>
+
+#include <frg/mutex.hpp>
+#include <mlibc/lock.hpp>
+#include <mlibc/debug.hpp>
+
+// This syslog implementation is largely taken from musl
+
+static char log_ident[32];
+static int log_options;
+static int log_facility = LOG_USER;
+static int log_fd = -1;
+static int log_opt;
+static int log_mask = 0xff;
+
+static int use_mlibc_logger = 0;
+static FutexLock __syslog_lock;
+
+static const struct sockaddr_un log_addr {AF_UNIX, "/dev/log"};
+
+void closelog(void) {
+	frg::unique_lock<FutexLock> holder { __syslog_lock };
+	close(log_fd);
+	log_fd = -1;
+}
+
+static void __openlog() {
+	log_fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+	if(log_fd >= 0) {
+		int ret = connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr);
+		if(ret) {
+			mlibc::infoLogger() << "\e[31mmlibc: syslog: connect returned an error, falling back to infoLogger\e[39m" << frg::endlog;
+			use_mlibc_logger = 1;
+		}
+	}
+}
+
+void openlog(const char *ident, int options, int facility) {
+	frg::unique_lock<FutexLock> holder { __syslog_lock };
+	if(ident) {
+		size_t n = strnlen(ident, sizeof log_ident - 1);
+		memcpy(log_ident, ident, n);
+		log_ident[n] = 0;
+	} else {
+		log_ident[0] = 0;
+	}
+	log_options = options;
+	log_facility = facility;
+
+	if((options & LOG_NDELAY) && log_fd < 0)
+		__openlog();
+}
+
+int setlogmask(int mask) {
+	int old_mask = log_mask;
+
+	log_mask = mask;
+
+	return old_mask;
+}
+
+static void _vsyslog(int priority, const char *message, va_list ap) {
+	auto is_lost_conn = [] (int e) {
+		return e == ECONNREFUSED || e == ECONNRESET || e == ENOTCONN || e == EPIPE;
+	};
+
+	if(!(priority & log_mask)) {
+		return;
+	}
+
+	char timebuf[16];
+	time_t now;
+	struct tm tm;
+	char buf[1024];
+	int errno_save = errno;
+	int pid;
+	int l, l2;
+	int hlen;
+	int fd;
+
+	if(log_fd < 0)
+		__openlog();
+
+	if(use_mlibc_logger) {
+		vsnprintf(buf, sizeof buf, message, ap);
+		mlibc::infoLogger() << "mlibc: syslog: " << buf << frg::endlog;
+		return;
+	}
+
+	if(!(priority & LOG_FACMASK))
+		priority |= log_facility;
+
+	now = time(NULL);
+	gmtime_r(&now, &tm);
+	strftime(timebuf, sizeof timebuf, "%b %e %T", &tm);
+
+	pid = (log_opt & LOG_PID) ? getpid() : 0;
+	l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ",
+		priority, timebuf, &hlen, log_ident, "[" + !pid, pid, "]" + !pid);
+	errno = errno_save;
+	l2 = vsnprintf(buf + l, sizeof buf - l, message, ap);
+	if(l2 >= 0) {
+		if(l2 >= (long int)(sizeof buf - l))
+			l = sizeof buf - 1;
+		else
+			l += l2;
+		if(buf[l - 1] != '\n')
+			buf[l++] = '\n';
+		if(send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno)
+		    || connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr) < 0
+		    || send(log_fd, buf, l, 0) < 0)
+		    && (log_opt & LOG_CONS)) {
+			fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+			if(fd >= 0) {
+				dprintf(fd, "%.*s", l - hlen, buf + hlen);
+				close(fd);
+			}
+		}
+		if(log_opt & LOG_PERROR)
+			dprintf(STDERR_FILENO, "%.*s", l - hlen, buf + hlen);
+	}
+}
+
+void syslog(int priority, const char *format, ...) {
+	va_list ap;
+	va_start(ap, format);
+	vsyslog(priority, format, ap);
+	va_end(ap);
+}
+
+void vsyslog(int priority, const char *message, va_list ap) {
+	int cs;
+	if(!(log_mask & LOG_MASK(priority & 7)) || (priority & ~0x3ff)) {
+		mlibc::infoLogger() << "\e[31mmlibc: syslog: log_mask or priority out of range, not printing anything\e[39m" << frg::endlog;
+		return;
+	}
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	frg::unique_lock<FutexLock> lock(__syslog_lock);
+	_vsyslog(priority, message, ap);
+	pthread_setcancelstate(cs, 0);
+}
diff --git a/lib/mlibc/options/posix/generic/termios-stubs.cpp b/lib/mlibc/options/posix/generic/termios-stubs.cpp
new file mode 100644
index 0000000..631456a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/termios-stubs.cpp
@@ -0,0 +1,103 @@
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+#include <errno.h>
+#include <termios.h>
+#include <sys/ioctl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+speed_t cfgetispeed(const struct termios *tios) {
+	return tios->c_cflag & CBAUD;
+}
+
+speed_t cfgetospeed(const struct termios *tios) {
+	return tios->c_cflag & CBAUD;
+}
+
+int cfsetispeed(struct termios *termios, speed_t speed) {
+	return speed ? cfsetospeed(termios, speed) : 0;
+}
+
+int cfsetospeed(struct termios *termios, speed_t speed) {
+	if(speed & ~CBAUD) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	termios->c_cflag &= ~CBAUD;
+	termios->c_cflag |= speed;
+
+	return 0;
+}
+
+void cfmakeraw(struct termios *t) {
+	t->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+	t->c_oflag &= ~OPOST;
+	t->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+	t->c_cflag &= ~(CSIZE | PARENB);
+	t->c_cflag |= CS8;
+	t->c_cc[VMIN] = 1;
+	t->c_cc[VTIME] = 0;
+}
+
+int tcdrain(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcdrain, -1);
+	if(int e = mlibc::sys_tcdrain(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcflow(int fd, int action) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcflow, -1);
+	if(int e = mlibc::sys_tcflow(fd, action); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcflush(int fd, int queue_selector) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcflush, -1);
+	if(int e = mlibc::sys_tcflush(fd, queue_selector); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcgetattr(int fd, struct termios *attr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcgetattr, -1);
+	if(int e = mlibc::sys_tcgetattr(fd, attr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t tcgetsid(int fd) {
+	int sid;
+	if(ioctl(fd, TIOCGSID, &sid) < 0) {
+		return -1;
+	}
+	return sid;
+}
+
+int tcsendbreak(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int tcsetattr(int fd, int opts, const struct termios *attr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcsetattr, -1);
+	if(int e = mlibc::sys_tcsetattr(fd, opts, attr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/time.cpp b/lib/mlibc/options/posix/generic/time.cpp
new file mode 100644
index 0000000..14193af
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/time.cpp
@@ -0,0 +1,505 @@
+#include <ctype.h>
+#include <langinfo.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <bits/ensure.h>
+#include <mlibc/strings.hpp>
+
+namespace {
+
+int month_to_day(int month) {
+	switch(month){
+		case  0: return 0;
+		case  1: return 31;
+		case  2: return 59;
+		case  3: return 90;
+		case  4: return 120;
+		case  5: return 151;
+		case  6: return 181;
+		case  7: return 212;
+		case  8: return 243;
+		case  9: return 273;
+		case 10: return 304;
+		case 11: return 334;
+	}
+	return -1;
+}
+
+int is_leapyear(int year) {
+	return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
+}
+
+int month_and_year_to_day_in_year(int month, int year){
+	int day = month_to_day(month);
+	if(is_leapyear(year) && month < 2)
+		return day + 1;
+
+	return day;
+}
+
+int target_determination(int month) {
+	switch(month){
+		case 0: return 3;
+		case 1: return 14;
+		case 2: return 14;
+		case 3: return 4;
+		case 4: return 9;
+		case 5: return 6;
+		case 6: return 11;
+		case 7: return 8;
+		case 8: return 5;
+		case 9: return 10;
+		case 10: return 7;
+		case 11: return 12;
+	}
+
+	return -1;
+}
+
+int doom_determination(int full_year) {
+	int century = full_year / 100;
+	int anchor = 2 + 5 * (century % 4) % 7;
+
+	int year = full_year % 100;
+
+	if(year % 2)
+		year += 11;
+
+	year /= 2;
+
+	if(year % 2)
+		year += 11;
+
+	return 7 - (year % 7) + anchor;
+}
+
+//Determine day of week through the doomsday algorithm.
+int day_determination(int day, int month, int year) {
+	int doom = doom_determination(year);
+	bool leap = is_leapyear(year);
+
+	int target = target_determination(month);
+	if(leap && month < 2)
+		target++;
+
+	int doom_dif = (day - target) % 7;
+	return (doom + doom_dif) % 7;
+}
+
+struct strptime_internal_state {
+	bool has_century;
+	bool has_year;
+	bool has_month;
+	bool has_day_of_month;
+	bool has_day_of_year;
+	bool has_day_of_week;
+
+	bool full_year_given;
+
+	int century;
+
+	size_t format_index;
+	size_t input_index;
+};
+
+char *strptime_internal(const char *__restrict input, const char *__restrict format,
+	struct tm *__restrict tm, struct strptime_internal_state *__restrict state) {
+	auto matchLanginfoItem = [&] (int start, size_t num, int &dest, bool &flag) -> bool {
+		for(size_t i = start; i < (start + num); i++) {
+			const char *mon = nl_langinfo(i);
+			size_t len = strlen(mon);
+			if(mlibc::strncasecmp(&input[state->input_index], mon, len))
+				continue;
+			state->input_index += len;
+			dest = i - start;
+			flag = true;
+			return true;
+		}
+		return false;
+	};
+
+	auto matchNumericRange = [&] (int start, int end, int &dest, bool *flag) -> bool {
+		int product = 0, n = 0;
+		sscanf(&input[state->input_index], "%d%n", &product, &n);
+		if(n == 0 || 2 < n)
+			return false;
+		if(product < start || product > end)
+			return false;
+		state->input_index += n;
+		dest = product;
+		if(flag) *flag = true;
+		return true;
+	};
+
+	while(isspace(input[state->input_index]))
+		state->input_index++;
+
+	if(input[state->input_index] == '\0')
+		return NULL;
+
+	while(format[state->format_index] != '\0'){
+		if(format[state->format_index] != '%'){
+			if(isspace(format[state->format_index])){
+				while(isspace(input[state->input_index++]));
+				state->input_index--;
+			}
+			else {
+				if(format[state->format_index] != input[state->input_index++])
+					return NULL;
+			}
+			state->format_index++;
+			continue;
+		}
+		state->format_index++;
+		switch(format[state->format_index]){
+			case '%':
+				if(input[state->input_index++] != '%')
+					return NULL;
+				break;
+			case 'a':
+			case 'A': {
+				if (!matchLanginfoItem(DAY_1, 7, tm->tm_wday, state->has_day_of_week) && \
+					!matchLanginfoItem(ABDAY_1, 7, tm->tm_wday, state->has_day_of_week))
+					return NULL;
+				break;
+			}
+			case 'b':
+			case 'B':
+			case 'h': {
+				if (!matchLanginfoItem(MON_1, 12, tm->tm_mon, state->has_month) && \
+					!matchLanginfoItem(ABMON_1, 12, tm->tm_mon, state->has_month))
+					return NULL;
+				break;
+			}
+			case 'c':
+				__ensure(!"strptime() %c directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'C': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 2 < n)
+					return NULL;
+				state->input_index += n;
+				state->century = product;
+				state->has_century = true;
+				break;
+			}
+			case 'd': //`%d` and `%e` are equivalent
+			case 'e': {
+				if(!matchNumericRange(1, 31, tm->tm_mday, &state->has_day_of_month))
+					return NULL;
+				break;
+			}
+			case 'D': { //equivalent to `%m/%d/%y`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%m/%d/%y", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'H': {
+				if(!matchNumericRange(0, 23, tm->tm_hour, nullptr))
+					return NULL;
+				break;
+			}
+			case 'I': {
+				if(!matchNumericRange(1, 12, tm->tm_hour, nullptr))
+					return NULL;
+				break;
+			}
+			case 'j': {
+				if(!matchNumericRange(1, 366, tm->tm_yday, &state->has_day_of_year))
+					return NULL;
+				tm->tm_yday--;
+				break;
+			}
+			case 'm': {
+				if(!matchNumericRange(1, 12, tm->tm_mon, &state->has_month))
+					return NULL;
+				tm->tm_mon--;
+				break;
+			}
+			case 'M': {
+				if(!matchNumericRange(0, 59, tm->tm_min, nullptr))
+					return NULL;
+				break;
+			}
+			case 'n':
+			case 't': {
+				size_t n = 0;
+				while(isspace(input[state->input_index++]))
+					n++;
+				if(n == 0)
+					return NULL;
+				state->input_index--;
+				break;
+			}
+			case 'p': {
+				const char *meridian_str = nl_langinfo(AM_STR);
+				size_t len = strlen(meridian_str);
+				if (!mlibc::strncasecmp(&input[state->input_index], meridian_str, len)) {
+					tm->tm_hour %= 12;
+					state->input_index += len;
+					break;
+				}
+				meridian_str = nl_langinfo(PM_STR);
+				len = strlen(meridian_str);
+				if (!mlibc::strncasecmp(&input[state->input_index], meridian_str, len)) {
+					tm->tm_hour %= 12;
+					tm->tm_hour += 12;
+					state->input_index += len;
+					break;
+				}
+				break;
+			}
+			case 'r': {  //equivalent to `%I:%M:%S %p`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%I:%M:%S %p", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'R': { //equivalent to `%H:%M`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%H:%M", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'S': {
+				if(!matchNumericRange(0, 60, tm->tm_sec, nullptr))
+					return NULL;
+				break;
+			}
+			case 'T': { //equivalent to `%H:%M:%S`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%H:%M:%S", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'U':
+				__ensure(!"strptime() %U directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'w': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 1 < n)
+					return NULL;
+				state->input_index += n;
+				tm->tm_wday = product;
+				state->has_day_of_week = true;
+				break;
+			}
+			case 'W':
+				__ensure(!"strptime() %W directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'x':
+				__ensure(!"strptime() %x directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'X':
+				__ensure(!"strptime() %X directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'y': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 2 < n)
+					return NULL;
+				if(product < 69)
+					product += 100;
+				state->input_index += n;
+				tm->tm_year = product;
+				state->has_year = true;
+				break;
+			}
+			case 'Y': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 4 < n)
+					return NULL;
+				state->input_index += n;
+				tm->tm_year = product - 1900;
+				state->has_year = true;
+				state->has_century = true;
+				state->full_year_given = true;
+				state->century = product / 100;
+				break;
+			}
+			case 'F': { //GNU extensions
+				//equivalent to `%Y-%m-%d`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%Y-%m-%d", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'g':
+				__ensure(!"strptime() %g directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'G':
+				__ensure(!"strptime() %G directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'u': {
+				if(!matchNumericRange(1, 7, tm->tm_wday, nullptr))
+					return NULL;
+				tm->tm_wday--;
+				break;
+			}
+			case 'V':
+				__ensure(!"strptime() %V directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'z':
+				__ensure(!"strptime() %z directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'Z':
+				__ensure(!"strptime() %Z directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 's': //end of GNU extensions
+				__ensure(!"strptime() %s directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'E': { //locale-dependent date & time representation
+				__ensure(!"strptime() %E* directives unimplemented.");
+				__builtin_unreachable();
+				/*
+				state->format_index++;
+				switch(format[state->format_index]){
+					case 'c':
+						break;
+					case 'C':
+						break;
+					case 'x':
+						break;
+					case 'X':
+						break;
+					case 'y':
+						break;
+					case 'Y':
+						break;
+					default:
+						return NULL;
+				}
+				*/
+			}
+			case 'O': { //locale-dependent numeric symbols
+				__ensure(!"strptime() %O* directives unimplemented.");
+				__builtin_unreachable();
+				/*
+				state->format_index++;
+				switch(format[state->format_index]){
+					case 'd':
+					case 'e':
+						break;
+					case 'H':
+						break;
+					case 'I':
+						break;
+					case 'm':
+						break;
+					case 'M':
+						break;
+					case 'S':
+						break;
+					case 'U':
+						break;
+					case 'w':
+						break;
+					case 'W':
+						break;
+					case 'y':
+						break;
+					default:
+						return NULL;
+				}
+				*/
+			}
+			default:
+				return NULL;
+		}
+		state->format_index++;
+	}
+
+	return (char*)input + state->input_index;
+}
+
+} //anonymous namespace
+
+char *strptime(const char *__restrict s, const char *__restrict format, struct tm *__restrict tm){
+	struct strptime_internal_state state = {};
+
+	char *result = strptime_internal(s, format, tm, &state);
+
+	if(result == NULL)
+		return NULL;
+
+	if(state.has_century && !state.full_year_given){
+		int full_year = state.century * 100;
+
+		if(state.has_year){
+			//Compensate for default century-adjustment of `%j` operand
+			if(tm->tm_year >= 100)
+				full_year += tm->tm_year - 100;
+			else
+				full_year += tm->tm_year;
+		}
+
+		tm->tm_year = full_year - 1900;
+
+		state.has_year = true;
+	}
+
+	if(state.has_month && !state.has_day_of_year){
+		int day = 0;
+		if(state.has_year)
+			day = month_and_year_to_day_in_year(tm->tm_mon, tm->tm_year);
+		else
+			day = month_to_day(tm->tm_mon);
+
+		tm->tm_yday = day + tm->tm_mday - 1;
+		state.has_day_of_year = true;
+	}
+
+	if(state.has_year && !state.has_day_of_week){
+		if(!state.has_month && !state.has_day_of_month){
+			tm->tm_wday = day_determination(0, 0, tm->tm_year + 1900);
+		}
+		else if(state.has_month && state.has_day_of_month){
+			tm->tm_wday = day_determination(tm->tm_mday, tm->tm_mon, tm->tm_year + 1900);
+		}
+		state.has_day_of_week = true;
+	}
+
+	return result;
+}
diff --git a/lib/mlibc/options/posix/generic/ucontext-stubs.cpp b/lib/mlibc/options/posix/generic/ucontext-stubs.cpp
new file mode 100644
index 0000000..9413a78
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/ucontext-stubs.cpp
@@ -0,0 +1,19 @@
+#include <ucontext.h>
+#include <bits/ensure.h>
+
+int getcontext(ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+int setcontext(const ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+void makecontext(ucontext_t *, void (*)(), int, ...) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+int swapcontext(ucontext_t *, const ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/unistd-stubs.cpp b/lib/mlibc/options/posix/generic/unistd-stubs.cpp
new file mode 100644
index 0000000..39cf76a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/unistd-stubs.cpp
@@ -0,0 +1,1227 @@
+#include <stdio.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <unistd.h>
+#include <limits.h>
+#include <termios.h>
+#include <pwd.h>
+#include <sys/ioctl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/allocator.hpp>
+#include <mlibc/arch-defs.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/bsd-sysdeps.hpp>
+#include <mlibc/thread.hpp>
+
+namespace {
+
+constexpr bool logExecvpeTries = false;
+
+}
+
+unsigned int alarm(unsigned int seconds) {
+	struct itimerval it = {}, old = {};
+	it.it_value.tv_sec = seconds;
+	setitimer(ITIMER_REAL, &it, &old);
+	return old.it_value.tv_sec + !! old.it_value.tv_usec;
+}
+
+int chdir(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chdir, -1);
+	if(int e = mlibc::sys_chdir(path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchdir(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchdir, -1);
+	if(int e = mlibc::sys_fchdir(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int chown(const char *path, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(AT_FDCWD, path, uid, gid, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t confstr(int name, char *buf, size_t len) {
+	const char *str = "";
+	if (name == _CS_PATH) {
+		str = "/bin:/usr/bin";
+	} else if(name == _CS_GNU_LIBPTHREAD_VERSION) {
+		// We are not glibc, so we can return 0 here.
+		return 0;
+	} else if(name == _CS_GNU_LIBC_VERSION) {
+		// We are not glibc, so we can return 0 here.
+		return 0;
+	} else {
+		mlibc::infoLogger() << "\e[31mmlibc: confstr() request " << name << " is unimplemented\e[39m"
+				<< frg::endlog;
+		__ensure(!"Not implemented");
+	}
+
+	return snprintf(buf, len, "%s", str) + 1;
+}
+
+void _exit(int status) {
+	mlibc::sys_exit(status);
+}
+
+int execl(const char *path, const char *arg0, ...) {
+	// TODO: It's a stupid idea to limit the number of arguments here.
+	char *argv[16];
+	argv[0] = const_cast<char *>(arg0);
+
+	va_list args;
+	int n = 1;
+	va_start(args, arg0);
+	while(true) {
+		__ensure(n < 15);
+		auto argn = va_arg(args, const char *);
+		argv[n++] = const_cast<char *>(argn);
+		if(!argn)
+			break;
+	}
+	va_end(args);
+	argv[n] = nullptr;
+
+	return execve(path, argv, environ);
+}
+
+// This function is taken from musl.
+int execle(const char *path, const char *arg0, ...) {
+	int argc;
+	va_list ap;
+	va_start(ap, arg0);
+	for(argc = 1; va_arg(ap, const char *); argc++);
+	va_end(ap);
+
+	int i;
+	char *argv[argc + 1];
+	char **envp;
+	va_start(ap, arg0);
+	argv[0] = (char *)argv;
+	for(i = 1; i <= argc; i++)
+		argv[i] = va_arg(ap, char *);
+	envp = va_arg(ap, char **);
+	va_end(ap);
+	return execve(path, argv, envp);
+}
+
+// This function is taken from musl
+int execlp(const char *file, const char *argv0, ...) {
+	int argc;
+	va_list ap;
+	va_start(ap, argv0);
+	for(argc = 1; va_arg(ap, const char *); argc++);
+	va_end(ap);
+	{
+		int i;
+		char *argv[argc + 1];
+		va_start(ap, argv0);
+		argv[0] = (char *)argv0;
+		for(i = 1; i < argc; i++)
+			argv[i] = va_arg(ap, char *);
+		argv[i] = NULL;
+		va_end(ap);
+		return execvp(file, argv);
+	}
+}
+
+int execv(const char *path, char *const argv[]) {
+	return execve(path, argv, environ);
+}
+
+int execvp(const char *file, char *const argv[]) {
+	return execvpe(file, argv, environ);
+}
+
+int execvpe(const char *file, char *const argv[], char *const envp[]) {
+	char *null_list[] = {
+		nullptr
+	};
+
+	if(!argv)
+		argv = null_list;
+	if(!envp)
+		envp = null_list;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_execve, -1);
+
+	if(strchr(file, '/')) {
+		int e = mlibc::sys_execve(file, argv, envp);
+		__ensure(e && "sys_execve() is supposed to never return with success");
+		errno = e;
+		return -1;
+	}
+
+	frg::string_view dirs;
+	if(const char *pv = getenv("PATH"); pv) {
+		dirs = pv;
+	}else{
+		dirs = "/bin:/usr/bin";
+	}
+
+	size_t p = 0;
+	int res = ENOENT;
+	while(p < dirs.size()) {
+		size_t s; // Offset of next colon or end of string.
+		if(size_t cs = dirs.find_first(':', p); cs != size_t(-1)) {
+			s = cs;
+		}else{
+			s = dirs.size();
+		}
+
+		frg::string<MemoryAllocator> path{getAllocator()};
+		path += dirs.sub_string(p, s - p);
+		path += "/";
+		path += file;
+
+		if(logExecvpeTries)
+			mlibc::infoLogger() << "mlibc: execvpe() tries '" << path.data() << "'" << frg::endlog;
+
+		int e = mlibc::sys_execve(path.data(), argv, envp);
+		__ensure(e && "sys_execve() is supposed to never return with success");
+		switch(e) {
+		case ENOENT:
+		case ENOTDIR:
+			break;
+		case EACCES:
+			res = EACCES;
+			break;
+		default:
+			errno = e;
+			return -1;
+		}
+
+		p = s + 1;
+	}
+
+	errno = res;
+	return -1;
+}
+
+int faccessat(int dirfd, const char *pathname, int mode, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_faccessat, -1);
+	if(int e = mlibc::sys_faccessat(dirfd, pathname, mode, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchown(int fd, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(fd, "", uid, gid, AT_EMPTY_PATH); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchownat(int fd, const char *path, uid_t uid, gid_t gid, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(fd, path, uid, gid, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fdatasync(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fdatasync, -1);
+	if(int e = mlibc::sys_fdatasync(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fexecve(int, char *const [], char *const []) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+long fpathconf(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int fsync(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fsync, -1);
+	if(auto e = mlibc::sys_fsync(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int ftruncate(int fd, off_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ftruncate, -1);
+	if(int e = mlibc::sys_ftruncate(fd, size); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+char *getcwd(char *buffer, size_t size) {
+	if (buffer) {
+		if (size == 0) {
+			errno = EINVAL;
+			return NULL;
+		}
+	} else if (!buffer) {
+		if (size == 0)
+			size = PATH_MAX;
+
+		buffer = (char *)malloc(size);
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getcwd, nullptr);
+	if(int e = mlibc::sys_getcwd(buffer, size); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return buffer;
+}
+
+int getgroups(int size, gid_t list[]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getgroups, -1);
+	int ret;
+	if(int e = mlibc::sys_getgroups(size, list, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
+
+long gethostid(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int gethostname(char *buffer, size_t bufsize) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_gethostname, -1);
+	if(auto e = mlibc::sys_gethostname(buffer, bufsize); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int sethostname(const char *buffer, size_t bufsize) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sethostname, -1);
+	if(auto e = mlibc::sys_sethostname(buffer, bufsize); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// Code taken from musl
+char *getlogin(void) {
+	return getenv("LOGNAME");
+}
+
+int getlogin_r(char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// optarg and optind are provided to us by the GLIBC part of the mlibc.
+
+static char *scan = NULL; /* Private scan pointer. */
+
+int getopt(int argc, char *const argv[], const char *optstring) {
+	char c;
+	char *place;
+
+	optarg = NULL;
+
+	if (!scan || *scan == '\0') {
+		if (optind == 0)
+			optind++;
+
+		if (optind >= argc || argv[optind][0] != '-' || argv[optind][1] == '\0')
+			return EOF;
+		if (argv[optind][1] == '-' && argv[optind][2] == '\0') {
+			optind++;
+			return EOF;
+		}
+
+		scan = argv[optind]+1;
+		optind++;
+	}
+
+	c = *scan++;
+	place = strchr(optstring, c);
+
+	if (!place || c == ':') {
+		fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
+		return '?';
+	}
+
+	place++;
+	if (*place == ':') {
+		if (*scan != '\0') {
+			optarg = scan;
+			scan = NULL;
+		} else if( optind < argc ) {
+			optarg = argv[optind];
+			optind++;
+		} else {
+			fprintf(stderr, "%s: option requires argument -%c\n", argv[0], c);
+			return ':';
+		}
+	}
+
+	return c;
+}
+
+pid_t getpgid(pid_t pid) {
+	pid_t pgid;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getpgid, -1);
+	if(int e = mlibc::sys_getpgid(pid, &pgid); e) {
+		errno = e;
+		return -1;
+	}
+	return pgid;
+}
+
+pid_t getpgrp(void) {
+	return getpgid(0);
+}
+
+pid_t getsid(pid_t pid) {
+	if(!mlibc::sys_getsid) {
+		MLIBC_MISSING_SYSDEP();
+		return -1;
+	}
+	pid_t sid;
+	if(int e = mlibc::sys_getsid(pid, &sid); e) {
+		errno = e;
+		return -1;
+	}
+	return sid;
+}
+
+int lchown(const char *path, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(AT_FDCWD, path, uid, gid, AT_SYMLINK_NOFOLLOW); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int link(const char *old_path, const char *new_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_link, -1);
+	if(int e = mlibc::sys_link(old_path, new_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int linkat(int olddirfd, const char *old_path, int newdirfd, const char *new_path, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_linkat, -1);
+	if(int e = mlibc::sys_linkat(olddirfd, old_path, newdirfd, new_path, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// Code take from musl
+int lockf(int fd, int op, off_t size) {
+	struct flock l = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_CUR,
+		.l_start = 0,
+		.l_len = size,
+		.l_pid = 0,
+	};
+
+	switch(op) {
+		case F_TEST:
+			l.l_type = F_RDLCK;
+			if(fcntl(fd, F_GETLK, &l) < 0)
+				return -1;
+			if(l.l_type == F_UNLCK || l.l_pid == getpid())
+				return 0;
+			errno = EACCES;
+			return -1;
+		case F_ULOCK:
+			l.l_type = F_UNLCK;
+			[[fallthrough]];
+		case F_TLOCK:
+			return fcntl(fd, F_SETLK, &l);
+		case F_LOCK:
+			return fcntl(fd, F_SETLKW, &l);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+int nice(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+long pathconf(const char *, int name) {
+	switch (name) {
+	case _PC_NAME_MAX:
+		return NAME_MAX;
+	default:
+		mlibc::infoLogger() << "missing pathconf() entry " << name << frg::endlog;
+		errno = EINVAL;
+		return -1;
+	}
+}
+
+int pause(void) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pause, -1);
+	if(int e = mlibc::sys_pause(); e) {
+		errno = e;
+		return -1;
+	}
+	__ensure(!"There is no successful completion return value for pause");
+	__builtin_unreachable();
+}
+
+int pipe(int *fds) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pipe, -1);
+	if(int e = mlibc::sys_pipe(fds, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int pipe2(int *fds, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pipe, -1);
+	if(int e = mlibc::sys_pipe(fds, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t pread(int fd, void *buf, size_t n, off_t off) {
+	ssize_t num_read;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pread, -1);
+	if(int e = mlibc::sys_pread(fd, buf, n, off, &num_read); e) {
+		errno = e;
+		return -1;
+	}
+	return num_read;
+}
+
+ssize_t pwrite(int fd, const void *buf, size_t n, off_t off) {
+	ssize_t num_written;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pwrite, -1);
+	if(int e = mlibc::sys_pwrite(fd, buf, n, off, &num_written); e) {
+		errno = e;
+		return -1;
+	}
+	return num_written;
+}
+
+ssize_t readlink(const char *__restrict path, char *__restrict buffer, size_t max_size) {
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_readlink, -1);
+	if(int e = mlibc::sys_readlink(path, buffer, max_size, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+ssize_t readlinkat(int, const char *__restrict, char *__restrict, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int rmdir(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_rmdir, -1);
+	if(int e = mlibc::sys_rmdir(path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setegid(gid_t egid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setegid, 0);
+	if(int e = mlibc::sys_setegid(egid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int seteuid(uid_t euid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_seteuid, 0);
+	if(int e = mlibc::sys_seteuid(euid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setgid(gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setgid, 0);
+	if(int e = mlibc::sys_setgid(gid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setpgid(pid_t pid, pid_t pgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setpgid, -1);
+	if(int e = mlibc::sys_setpgid(pid, pgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t setpgrp(void) {
+	return setpgid(0, 0);
+}
+
+int setregid(gid_t rgid, gid_t egid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setregid, -1);
+	if(int e = mlibc::sys_setregid(rgid, egid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setreuid(uid_t ruid, uid_t euid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setreuid, -1);
+	if(int e = mlibc::sys_setreuid(ruid, euid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t setsid(void) {
+	if(!mlibc::sys_setsid) {
+		MLIBC_MISSING_SYSDEP();
+		return -1;
+	}
+	pid_t sid;
+	if(int e = mlibc::sys_setsid(&sid); e) {
+		errno = e;
+		return -1;
+	}
+	return sid;
+}
+
+int setuid(uid_t uid) {
+	if(!mlibc::sys_setuid) {
+		MLIBC_MISSING_SYSDEP();
+		mlibc::infoLogger() << "mlibc: missing sysdep sys_setuid(). Returning 0" << frg::endlog;
+		return 0;
+	}
+	if(int e = mlibc::sys_setuid(uid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void swab(const void *__restrict, void *__restrict, ssize_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int symlink(const char *target_path, const char *link_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_symlink, -1);
+	if(int e = mlibc::sys_symlink(target_path, link_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int symlinkat(const char *target_path, int dirfd, const char *link_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_symlinkat, -1);
+	if(int e = mlibc::sys_symlinkat(target_path, dirfd, link_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void sync(void) {
+	if(!mlibc::sys_sync) {
+		MLIBC_MISSING_SYSDEP();
+	} else {
+		mlibc::sys_sync();
+	}
+}
+
+long sysconf(int number) {
+	if(mlibc::sys_sysconf) {
+		long ret = 0;
+
+		int e = mlibc::sys_sysconf(number, &ret);
+
+		if(e && e != EINVAL) {
+			errno = e;
+			return -1;
+		}
+
+		if(e != EINVAL) {
+			return ret;
+		}
+	}
+
+	/* default return values, if not overriden by sysdep */
+	switch(number) {
+		case _SC_ARG_MAX:
+			// On linux, it is defined to 2097152 in most cases, so define it to be 2097152
+			return 2097152;
+		case _SC_PAGE_SIZE:
+			return mlibc::page_size;
+		case _SC_OPEN_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_OPEN_MAX) returns fallback value 256\e[39m" << frg::endlog;
+			return 256;
+		case _SC_PHYS_PAGES:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_PHYS_PAGES) returns fallback value 1024\e[39m" << frg::endlog;
+			return 1024;
+		case _SC_NPROCESSORS_ONLN:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NPROCESSORS_ONLN) returns fallback value 1\e[39m" << frg::endlog;
+			return 1;
+		case _SC_GETPW_R_SIZE_MAX:
+			return NSS_BUFLEN_PASSWD;
+		case _SC_GETGR_R_SIZE_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_GETGR_R_SIZE_MAX) returns fallback value 1024\e[39m" << frg::endlog;
+			return 1024;
+		case _SC_CHILD_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_CHILD_MAX) returns fallback value 25\e[39m" << frg::endlog;
+			// On linux, it is defined to 25 in most cases, so define it to be 25
+			return 25;
+		case _SC_JOB_CONTROL:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_JOB_CONTROL) returns fallback value 1\e[39m" << frg::endlog;
+			// If 1, job control is supported
+			return 1;
+		case _SC_CLK_TCK:
+			// TODO: This should be obsolete?
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_CLK_TCK) is obsolete and returns arbitrary value 1000000\e[39m" << frg::endlog;
+			return 1000000;
+		case _SC_NGROUPS_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NGROUPS_MAX) returns fallback value 65536\e[39m" << frg::endlog;
+			// On linux, it is defined to 65536 in most cases, so define it to be 65536
+			return 65536;
+		case _SC_RE_DUP_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_RE_DUP_MAX) returns fallback value RE_DUP_MAX\e[39m" << frg::endlog;
+			return RE_DUP_MAX;
+		case _SC_LINE_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_LINE_MAX) returns fallback value 2048\e[39m" << frg::endlog;
+			// Linux defines it as 2048.
+			return 2048;
+		case _SC_XOPEN_CRYPT:
+#if __MLIBC_CRYPT_OPTION
+			return _XOPEN_CRYPT;
+#else
+			return -1;
+#endif /* __MLIBC_CRYPT_OPTION */
+		case _SC_NPROCESSORS_CONF:
+			// TODO: actually return a proper value for _SC_NPROCESSORS_CONF
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NPROCESSORS_CONF) unconditionally returns fallback value 1\e[39m" << frg::endlog;
+			return 1;
+		case _SC_HOST_NAME_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_HOST_NAME_MAX) unconditionally returns fallback value 256\e[39m" << frg::endlog;
+			return 256;
+		default:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf() call is not implemented, number: " << number << "\e[39m" << frg::endlog;
+			errno = EINVAL;
+			return -1;
+	}
+}
+
+pid_t tcgetpgrp(int fd) {
+	int pgrp;
+	if(ioctl(fd, TIOCGPGRP, &pgrp) < 0) {
+		return -1;
+	}
+	return pgrp;
+}
+
+int tcsetpgrp(int fd, pid_t pgrp) {
+	return ioctl(fd, TIOCSPGRP, &pgrp);
+}
+
+int truncate(const char *, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *ttyname(int fd) {
+	const size_t size = 128;
+	static thread_local char buf[size];
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ttyname, nullptr);
+	if(int e = mlibc::sys_ttyname(fd, buf, size); e) {
+		errno = e;
+		return nullptr;
+	}
+	return buf;
+}
+
+int ttyname_r(int fd, char *buf, size_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ttyname, -1);
+	if(int e = mlibc::sys_ttyname(fd, buf, size); e) {
+		return e;
+	}
+	return 0;
+}
+
+int unlink(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlinkat, -1);
+	if(int e = mlibc::sys_unlinkat(AT_FDCWD, path, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int unlinkat(int fd, const char *path, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlinkat, -1);
+	if(int e = mlibc::sys_unlinkat(fd, path, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getpagesize() {
+	return mlibc::page_size;
+}
+
+// Code taken from musl
+// GLIBC extension for stdin/stdout
+char *getpass(const char *prompt) {
+	int fdin, fdout;
+	struct termios s, t;
+	ssize_t l;
+	static char password[128];
+
+	if((fdin = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0) {
+		fdin = STDIN_FILENO;
+		fdout = STDOUT_FILENO;
+	} else {
+		fdout = fdin;
+	}
+
+	tcgetattr(fdin, &t);
+	s = t;
+	t.c_lflag &= ~(ECHO | ISIG);
+	t.c_lflag |= ICANON;
+	t.c_iflag &= ~(INLCR | IGNCR);
+	t.c_iflag |= ICRNL;
+	tcsetattr(fdin, TCSAFLUSH, &t);
+	tcdrain(fdin);
+
+	dprintf(fdout, "%s", prompt);
+
+	l = read(fdin, password, sizeof password);
+	if(l >= 0) {
+		if((l > 0 && password[l - 1] == '\n') || l == sizeof password)
+			l--;
+		password[l] = 0;
+	}
+
+	tcsetattr(fdin, TCSAFLUSH, &s);
+
+	dprintf(fdout, "\n");
+	if(fdin != STDIN_FILENO) {
+		close(fdin);
+	}
+
+	return l < 0 ? 0 : password;
+}
+
+char *get_current_dir_name(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// This is a Linux extension
+pid_t gettid(void) {
+	if(!mlibc::sys_gettid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_gettid()");
+	}
+	return mlibc::sys_gettid();
+}
+
+int getentropy(void *buffer, size_t length) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getentropy, -1);
+	if(length > 256) {
+		errno = EIO;
+		return -1;
+	}
+	if(int e = mlibc::sys_getentropy(buffer, length); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t write(int fd, const void *buf, size_t count) {
+	ssize_t bytes_written;
+	if(int e = mlibc::sys_write(fd, buf, count, &bytes_written); e) {
+		errno = e;
+		return (ssize_t)-1;
+	}
+	return bytes_written;
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+	ssize_t bytes_read;
+	if(int e = mlibc::sys_read(fd, buf, count, &bytes_read); e) {
+		errno = e;
+		return (ssize_t)-1;
+	}
+	return bytes_read;
+}
+
+off_t lseek(int fd, off_t offset, int whence) {
+	off_t new_offset;
+	if(int e = mlibc::sys_seek(fd, offset, whence, &new_offset); e) {
+		errno = e;
+		return (off_t)-1;
+	}
+	return new_offset;
+}
+
+off64_t lseek64(int fd, off64_t offset, int whence) {
+	off64_t new_offset;
+	if(int e = mlibc::sys_seek(fd, offset, whence, &new_offset); e) {
+		errno = e;
+		return (off64_t)-1;
+	}
+	return new_offset;
+}
+
+int close(int fd) {
+	return mlibc::sys_close(fd);
+}
+
+unsigned int sleep(unsigned int secs) {
+	time_t seconds = secs;
+	long nanos = 0;
+	if(!mlibc::sys_sleep) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_sleep()");
+	}
+	mlibc::sys_sleep(&seconds, &nanos);
+	return seconds;
+}
+
+// In contrast to sleep() this functions returns 0/-1 on success/failure.
+int usleep(useconds_t usecs) {
+	time_t seconds = 0;
+	long nanos = usecs * 1000;
+	if(!mlibc::sys_sleep) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_sleep()");
+	}
+	return mlibc::sys_sleep(&seconds, &nanos);
+}
+
+int dup(int fd) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_dup, -1);
+	if(int e = mlibc::sys_dup(fd, 0, &newfd); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+int dup2(int fd, int newfd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_dup2, -1);
+	if(int e = mlibc::sys_dup2(fd, 0, newfd); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+pid_t fork(void) {
+	auto self = mlibc::get_current_tcb();
+	pid_t child;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fork, -1);
+
+	auto hand = self->atforkEnd;
+	while (hand) {
+		if (hand->prepare)
+			hand->prepare();
+
+		hand = hand->prev;
+	}
+
+	if(int e = mlibc::sys_fork(&child); e) {
+		errno = e;
+		return -1;
+	}
+
+	hand = self->atforkBegin;
+	while (hand) {
+		if (!child) {
+			if (hand->child)
+				hand->child();
+		} else {
+			if (hand->parent)
+				hand->parent();
+		}
+		hand = hand->next;
+	}
+
+	return child;
+}
+
+pid_t vfork(void) {
+	pid_t child;
+	/*
+	 * Fork handlers established using pthread_atfork(3) are not
+	 * called when a multithreaded program employing the NPTL
+	 * threading library calls vfork().  Fork handlers are called
+	 * in this case in a program using the LinuxThreads threading
+	 * library.  (See pthreads(7) for a description of Linux
+	 * threading libraries.)
+	 *  - vfork(2), release 5.13 of the Linux man-pages project
+	 *
+	 *  as a result, we call sys_fork instead of running atforks
+	 */
+
+	/* deferring to fork as implementing vfork correctly requires assembly
+	 * to handle not mucking up the stack
+	 */
+	if(!mlibc::sys_fork) {
+		MLIBC_MISSING_SYSDEP();
+		errno = ENOSYS;
+		return -1;
+	}
+
+	if(int e = mlibc::sys_fork(&child); e) {
+		errno = e;
+		return -1;
+	}
+
+	return child;
+}
+
+int execve(const char *path, char *const argv[], char *const envp[]) {
+	char *null_list[] = {
+		nullptr
+	};
+
+	if(!argv)
+		argv = null_list;
+	if(!envp)
+		envp = null_list;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_execve, -1);
+	int e = mlibc::sys_execve(path, argv, envp);
+	__ensure(e && "sys_execve() is expected to fail if it returns");
+	errno = e;
+	return -1;
+}
+
+gid_t getgid(void) {
+	if(!mlibc::sys_getgid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getgid()");
+	}
+	return mlibc::sys_getgid();
+}
+
+gid_t getegid(void) {
+	if(!mlibc::sys_getegid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getegid()");
+	}
+	return mlibc::sys_getegid();
+}
+
+uid_t getuid(void) {
+	if(!mlibc::sys_getuid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getuid()");
+	}
+	return mlibc::sys_getuid();
+}
+
+uid_t geteuid(void) {
+	if(!mlibc::sys_geteuid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_geteuid()");
+	}
+	return mlibc::sys_geteuid();
+}
+
+pid_t getpid(void) {
+	if(!mlibc::sys_getpid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getpid()");
+	}
+	return mlibc::sys_getpid();
+}
+
+pid_t getppid(void) {
+	if(!mlibc::sys_getppid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getppid()");
+	}
+	return mlibc::sys_getppid();
+}
+
+int access(const char *path, int mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_access, -1);
+	if(int e = mlibc::sys_access(path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+char *getusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int isatty(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_isatty, 0);
+	if(int e = mlibc::sys_isatty(fd); e) {
+		errno = e;
+		return 0;
+	}
+	return 1;
+}
+
+int chroot(const char *ptr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chroot, -1);
+	if(int e = mlibc::sys_chroot(ptr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int daemon(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *ctermid(char *s) {
+	return s ? strcpy(s, "/dev/tty") : const_cast<char *>("/dev/tty");
+}
+
+int setresuid(uid_t ruid, uid_t euid, uid_t suid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setresuid, -1);
+	if(int e = mlibc::sys_setresuid(ruid, euid, suid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setresgid(gid_t rgid, gid_t egid, gid_t sgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setresgid, -1);
+	if(int e = mlibc::sys_setresgid(rgid, egid, sgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getdomainname(char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int setdomainname(const char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getresuid, -1);
+	if(int e = mlibc::sys_getresuid(ruid, euid, suid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getresgid, -1);
+	if(int e = mlibc::sys_getresgid(rgid, egid, sgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+#if __MLIBC_CRYPT_OPTION
+void encrypt(char[64], int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+#endif
+
+#if __MLIBC_BSD_OPTION
+void *sbrk(intptr_t increment) {
+	if(increment) {
+		errno = ENOMEM;
+		return (void *)-1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_brk, (void *)-1);
+	void *out;
+	if(int e = mlibc::sys_brk(&out); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return out;
+}
+#endif
diff --git a/lib/mlibc/options/posix/generic/utime-stubs.cpp b/lib/mlibc/options/posix/generic/utime-stubs.cpp
new file mode 100644
index 0000000..f78729f
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/utime-stubs.cpp
@@ -0,0 +1,31 @@
+
+#include <utime.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int utime(const char *filename, const struct utimbuf *times) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	struct timespec time[2];
+	if(times) {
+		time[0].tv_sec = times->actime;
+		time[0].tv_nsec = 0;
+		time[1].tv_sec = times->modtime;
+		time[1].tv_nsec = 0;
+	} else {
+		time[0].tv_sec = UTIME_NOW;
+		time[0].tv_nsec = UTIME_NOW;
+		time[1].tv_sec = UTIME_NOW;
+		time[1].tv_nsec = UTIME_NOW;
+	}
+
+	if (int e = mlibc::sys_utimensat(AT_FDCWD, filename, time, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/wordexp-stubs.cpp b/lib/mlibc/options/posix/generic/wordexp-stubs.cpp
new file mode 100644
index 0000000..8443527
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/wordexp-stubs.cpp
@@ -0,0 +1,342 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * code taken from OPNSense, with modifications
+ *
+ * Copyright (c) 2002 Tim J. Robbins.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <wordexp.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdint.h>
+
+#define SHELL_PATH "/bin/sh"
+#define SHELL_NAME "sh"
+
+static size_t we_read_fully(int fd, char *buffer, size_t len) {
+	size_t done = 0;
+
+	do {
+		ssize_t nread = read(fd, buffer + done, len - done);
+		if(nread == -1 && errno == EINTR)
+			continue;
+		if(nread <= 0)
+			break;
+		done += nread;
+	} while (done != len);
+
+	return done;
+}
+
+static int we_askshell(const char *words, wordexp_t *we, int flags) {
+	int pdes[2]; /* pipe to child */
+	char bbuf[9]; /* buffer for byte count */
+	char wbuf[9]; /* buffer for word count */
+	size_t nwords = 0; /* number of words from child */
+	size_t nbytes = 0; /* number of bytes from child */
+	size_t sofs = 0; /* offset into we->we_strings */
+	size_t vofs = 0; /* offset into we->we_wordv */
+	pid_t pid; /* PID of child */
+	pid_t wpid; /* waitpid return value */
+	int status; /* child exit status */
+	int error; /* our return value */
+	int serrno; /* errno to return */
+	char *np, *p; /* handy pointers */
+	char *nstrings; /* temporary for realloc() */
+	char **new_wordv; /* temporary for realloc() */
+	sigset_t newsigblock;
+	sigset_t oldsigblock;
+	const char *ifs = getenv("IFS");
+
+	serrno = errno;
+
+	if(pipe2(pdes, O_CLOEXEC) < 0)
+		return WRDE_NOSPACE;
+
+	(void)sigemptyset(&newsigblock);
+	(void)sigaddset(&newsigblock, SIGCHLD);
+	(void)sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
+
+	if((pid = fork()) < 0) {
+		serrno = errno;
+		close(pdes[0]);
+		close(pdes[1]);
+		(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+		errno = serrno;
+		return WRDE_NOSPACE;
+	} else if(pid == 0) {
+		/*
+		 * We are the child; make /bin/sh expand `words'.
+		 */
+		(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+		if((pdes[1] != STDOUT_FILENO ? dup2(pdes[1], STDOUT_FILENO) : fcntl(pdes[1], F_SETFD, 0)) < 0)
+			_exit(1);
+
+		execl(SHELL_PATH, SHELL_NAME, flags & WRDE_UNDEF ? "-u" : "+u",
+			"-c", "IFS=$1;eval \"$2\";eval \"set -- $3\";IFS=;a=\"$*\";"
+			"printf '%08x' \"$#\" \"${#a}\";printf '%s\\0' \"$@\"", "",
+			ifs != NULL ? ifs : " \t\n",
+			flags & WRDE_SHOWERR ? "" : "exec 2>/dev/null",
+			words,
+			(char *)NULL);
+		_exit(1);
+	}
+
+	/*
+	 * We are the parent; read the output of the shell wordexp function,
+	 * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal
+	 * byte count (not including terminating null bytes), followed by
+	 * the expanded words separated by nulls.
+	 */
+	close(pdes[1]);
+	if(we_read_fully(pdes[0], wbuf, 8) != 8 || we_read_fully(pdes[0], bbuf, 8) != 8) {
+		error = flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+		serrno = errno;
+		goto cleanup;
+	}
+	wbuf[8] = bbuf[8] = '\0';
+	nwords = strtol(wbuf, NULL, 16);
+	nbytes = strtol(bbuf, NULL, 16) + nwords;
+
+	/*
+	 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
+	 * and string storage buffers for the expanded words we're about to
+	 * read from the child.
+	 */
+	sofs = we->we_nbytes;
+	vofs = we->we_wordc;
+	if((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS | WRDE_APPEND))
+		vofs += we->we_offs;
+	we->we_wordc += nwords;
+	we->we_nbytes += nbytes;
+
+	if((new_wordv = (char **) realloc(we->we_wordv, (we->we_wordc + 1 + (flags & WRDE_DOOFFS ?  we->we_offs : 0)) * sizeof(char *))) == NULL) {
+		error = WRDE_NOSPACE;
+		goto cleanup;
+	}
+
+	we->we_wordv = new_wordv;
+
+	if((nstrings = (char *) realloc(we->we_strings, we->we_nbytes)) == NULL) {
+		error = WRDE_NOSPACE;
+		goto cleanup;
+	}
+
+	for(size_t i = 0; i < vofs; i++) {
+		if(we->we_wordv[i] != NULL)
+			we->we_wordv[i] += nstrings - we->we_strings;
+	}
+	we->we_strings = nstrings;
+
+	if(we_read_fully(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
+		error = flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+		serrno = errno;
+		goto cleanup;
+	}
+
+	error = 0;
+cleanup:
+	close(pdes[0]);
+
+	do {
+		wpid = waitpid(pid, &status, 0);
+	} while(wpid < 0 && errno == EINTR);
+
+	(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+
+	if(error != 0) {
+		errno = serrno;
+		return error;
+	}
+
+	if(wpid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0)
+		return flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+
+	/*
+	 * Break the null-terminated expanded word strings out into
+	 * the vector.
+	 */
+	if(vofs == 0 && flags & WRDE_DOOFFS) {
+		while (vofs < we->we_offs)
+			we->we_wordv[vofs++] = NULL;
+	}
+
+	p = we->we_strings + sofs;
+	while (nwords-- != 0) {
+		we->we_wordv[vofs++] = p;
+		if((np = (char *) memchr(p, '\0', nbytes)) == NULL)
+			return WRDE_NOSPACE;
+
+		nbytes -= np - p + 1;
+		p = np + 1;
+	}
+
+	we->we_wordv[vofs] = NULL;
+	return 0;
+}
+
+/*
+ * we_check --
+ *	Check that the string contains none of the following unquoted
+ *	special characters: <newline> |&;<>(){}
+ *	or command substitutions when WRDE_NOCMD is set in flags.
+ */
+static int we_check(const char *words, int flags)
+{
+	char c;
+	int dquote, level, quote, squote;
+
+	quote = squote = dquote = 0;
+	while ((c = *words++) != '\0') {
+		switch (c) {
+			case '\\': {
+				if(squote == 0)
+					quote ^= 1;
+				continue;
+			}
+			case '\'': {
+				if(quote + dquote == 0)
+					squote ^= 1;
+				break;
+			}
+			case '"': {
+				if(quote + squote == 0)
+					dquote ^= 1;
+				break;
+			}
+			case '`': {
+				if(quote + squote == 0 && flags & WRDE_NOCMD)
+					return WRDE_CMDSUB;
+				while ((c = *words++) != '\0' && c != '`')
+					if(c == '\\' && (c = *words++) == '\0')
+						break;
+				if(c == '\0')
+					return WRDE_SYNTAX;
+				break;
+			}
+			case '|':
+			case '&':
+			case ';':
+			case '<':
+			case '>':
+			case '{':
+			case '}':
+			case '(':
+			case ')':
+			case '\n': {
+				if(quote + squote + dquote == 0)
+					return WRDE_BADCHAR;
+				break;
+			}
+			case '$': {
+				if((c = *words++) == '\0')
+					break;
+				else if(quote + squote == 0 && c == '(') {
+					if(flags & WRDE_NOCMD && *words != '(')
+						return WRDE_CMDSUB;
+					level = 1;
+					while ((c = *words++) != '\0') {
+						if(c == '\\') {
+							if((c = *words++) == '\0')
+								break;
+						} else if(c == '(')
+							level++;
+						else if(c == ')' && --level == 0)
+							break;
+					}
+					if(c == '\0' || level != 0)
+						return WRDE_SYNTAX;
+				} else if(quote + squote == 0 && c == '{') {
+					level = 1;
+					while ((c = *words++) != '\0') {
+						if(c == '\\') {
+							if((c = *words++) == '\0')
+								break;
+						} else if(c == '{')
+							level++;
+						else if(c == '}' && --level == 0)
+							break;
+					}
+					if(c == '\0' || level != 0)
+						return WRDE_SYNTAX;
+				} else
+					--words;
+				break;
+			}
+			default: {
+				break;
+			}
+		}
+		quote = 0;
+	}
+
+	if(quote + squote + dquote != 0)
+		return WRDE_SYNTAX;
+
+	return 0;
+}
+
+int wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags) {
+	int error;
+
+	if(flags & WRDE_REUSE)
+		wordfree(we);
+
+	if((flags & WRDE_APPEND) == 0) {
+		we->we_wordc = 0;
+		we->we_wordv = NULL;
+		we->we_strings = NULL;
+		we->we_nbytes = 0;
+	}
+
+	if((error = we_check(words, flags)) != 0) {
+		wordfree(we);
+		return error;
+	}
+
+	if((error = we_askshell(words, we, flags)) != 0) {
+		wordfree(we);
+		return error;
+	}
+
+	return 0;
+}
+
+void wordfree(wordexp_t *we) {
+	if (we == NULL)
+		return;
+	free(we->we_wordv);
+	free(we->we_strings);
+	we->we_wordv = NULL;
+	we->we_strings = NULL;
+	we->we_nbytes = 0;
+	we->we_wordc = 0;
+}