lib: Add mlibc

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

8 files changed, 935 insertions, 0 deletions

diff --git a/lib/mlibc/sysdeps/lemon/generic/entry.cpp b/lib/mlibc/sysdeps/lemon/generic/entry.cpp
new file mode 100644
index 0000000..f4cf144
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/entry.cpp
@@ -0,0 +1,33 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <bits/ensure.h>
+#include <mlibc/elf/startup.h>
+
+// defined by the POSIX library
+void __mlibc_initLocale();
+
+extern "C" uintptr_t *__dlapi_entrystack();
+
+extern char **environ;
+static mlibc::exec_stack_data __mlibc_stack_data;
+
+struct LibraryGuard {
+	LibraryGuard();
+};
+
+static LibraryGuard guard;
+
+LibraryGuard::LibraryGuard() {
+	__mlibc_initLocale();
+
+	// Parse the exec() stack.
+	mlibc::parse_exec_stack(__dlapi_entrystack(), &__mlibc_stack_data);
+	mlibc::set_startup_data(__mlibc_stack_data.argc, __mlibc_stack_data.argv,
+			__mlibc_stack_data.envp);
+}
+
+extern "C" void __mlibc_entry(int (*main_fn)(int argc, char *argv[], char *env[])) {
+	// TODO: call __dlapi_enter, otherwise static builds will break (see Linux sysdeps)
+	auto result = main_fn(__mlibc_stack_data.argc, __mlibc_stack_data.argv, environ);
+	exit(result);
+}
diff --git a/lib/mlibc/sysdeps/lemon/generic/filesystem.cpp b/lib/mlibc/sysdeps/lemon/generic/filesystem.cpp
new file mode 100755
index 0000000..4a7d780
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/filesystem.cpp
@@ -0,0 +1,406 @@
+#include <lemon/syscall.h>
+
+#include <asm/ioctls.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <dirent.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <bits/ensure.h>
+#include <mlibc/all-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+namespace mlibc{
+
+typedef struct {
+	dev_t st_dev;
+	ino_t st_ino;
+	mode_t st_mode;
+	nlink_t st_nlink;
+	uid_t st_uid;
+	uid_t st_gid;
+	dev_t st_rdev;
+	off_t st_size;
+	int64_t st_blksize;
+	int64_t st_blocks;
+} lemon_stat_t;
+
+int sys_write(int fd, const void* buffer, size_t count, ssize_t* written){
+	long ret = syscall(SYS_WRITE, fd, (uintptr_t)buffer, count);
+
+	if(ret < 0)
+		return -ret;
+
+	*written = ret;
+	return 0;
+}
+
+int sys_read(int fd, void *buf, size_t count, ssize_t *bytes_read) {
+	long ret = syscall(SYS_READ, fd, (uintptr_t)buf, count);
+
+	if(ret < 0){
+		*bytes_read = 0;
+		return -ret;
+	}
+
+	*bytes_read = ret;
+	return 0;
+}
+
+int sys_pwrite(int fd, const void* buffer, size_t count, off_t off, ssize_t* written){
+	int ret = syscall(SYS_PWRITE, fd, (uintptr_t)buffer, count, 0, off);
+
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*written = ret;
+	return 0;
+}
+
+int sys_pread(int fd, void *buf, size_t count, off_t off, ssize_t *bytes_read) {
+	int ret = syscall(SYS_PREAD, fd, (uintptr_t)buf, count, 0, off);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*bytes_read = ret;
+	return 0;
+}
+
+int sys_seek(int fd, off_t offset, int whence, off_t *new_offset) {
+	long ret = syscall(SYS_LSEEK, fd, offset, whence);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*new_offset = ret;
+	return 0;
+}
+
+
+int sys_open(const char* filename, int flags, mode_t mode, int* fd){
+	long ret = syscall(SYS_OPEN, (uintptr_t)filename, flags);
+
+	if(ret < 0)
+		return -ret;
+
+	*fd = ret;
+
+	return 0;
+}
+
+int sys_close(int fd){
+	syscall(SYS_CLOSE, fd);
+	return 0;
+}
+
+int sys_access(const char* filename, int mode){
+	int fd;
+	if(int e = sys_open(filename, O_RDONLY, 0, &fd)){
+		return e;
+	}
+
+	sys_close(fd);
+	return 0;
+}
+
+int sys_stat(fsfd_target fsfdt, int fd, const char *path, int flags, struct stat *statbuf){
+	long ret = 0;
+
+	lemon_stat_t lemonStat;
+	switch(fsfdt){
+		case fsfd_target::fd:
+			ret = syscall(SYS_FSTAT, &lemonStat, fd);
+			break;
+		case fsfd_target::path:
+			ret = syscall(SYS_STAT, &lemonStat, path);
+			break;
+		default:
+			mlibc::infoLogger() << "mlibc warning: sys_stat: unsupported fsfd target" << frg::endlog;
+			return EINVAL;
+	}
+
+	statbuf->st_dev = lemonStat.st_dev;
+	statbuf->st_ino = lemonStat.st_ino;
+	statbuf->st_mode = lemonStat.st_mode;
+	statbuf->st_nlink = lemonStat.st_nlink;
+	statbuf->st_uid = lemonStat.st_uid;
+	statbuf->st_gid = lemonStat.st_gid;
+	statbuf->st_rdev = lemonStat.st_rdev;
+	statbuf->st_size = lemonStat.st_size;
+	statbuf->st_blksize = lemonStat.st_blksize;
+	statbuf->st_blocks = lemonStat.st_blocks;
+
+	return -ret;
+}
+
+int sys_ioctl(int fd, unsigned long request, void *arg, int *result){
+	long ret = syscall(SYS_IOCTL, fd, request, arg, result);
+
+	if(ret < 0)
+		return -ret;
+
+	return 0;
+}
+
+#ifndef MLIBC_BUILDING_RTDL
+
+int sys_poll(struct pollfd *fds, nfds_t count, int timeout, int *num_events){
+	long ret = syscall(SYS_POLL, fds, count, timeout);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*num_events = ret;
+
+	return 0;
+}
+
+int sys_mkdir(const char* path, mode_t){
+	long ret = syscall(SYS_MKDIR, path);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_rmdir(const char* path){
+	long ret = syscall(SYS_RMDIR, path);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_link(const char* srcpath, const char* destpath){
+	long ret = syscall(SYS_LINK, srcpath, destpath);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_unlinkat(int fd, const char *path, int flags) {
+	long ret = syscall(SYS_UNLINK, fd, path, flags);
+
+	if(ret < 0) {
+		return -ret;
+	}
+
+	return 0;
+}
+
+typedef struct lemon_dirent {
+	uint32_t inode; // Inode number
+	uint32_t type;
+	char name[NAME_MAX]; // Filename
+} lemon_dirent_t;
+
+int sys_read_entries(int handle, void *buffer, size_t max_size, size_t *bytes_read){
+	lemon_dirent_t lemonDirent;
+	long ret = syscall(SYS_READDIR_NEXT, handle, &lemonDirent);
+
+	if(!ret){
+		*bytes_read = 0;
+		return 0;
+	} else if(ret > 0){
+		dirent* dir = (dirent*)buffer;
+		strcpy(dir->d_name, lemonDirent.name);
+		dir->d_ino = lemonDirent.inode;
+		dir->d_off = 0;
+		dir->d_reclen = sizeof(dirent);
+		dir->d_type = lemonDirent.type;
+
+		*bytes_read = sizeof(dirent);
+		return 0;
+	} else {
+		return -ret;
+	}
+}
+
+int sys_open_dir(const char* path, int* handle){
+	return sys_open(path, O_DIRECTORY, 0, handle);
+}
+
+int sys_rename(const char* path, const char* new_path){
+	return -syscall(SYS_RENAME, path, new_path);
+}
+
+int sys_readlink(const char *path, void *buffer, size_t max_size, ssize_t *length){
+	long ret = syscall(SYS_READLINK, path, buffer, max_size);
+	if(ret < 0){
+		return -ret;
+	}
+
+	*length = ret;
+	return 0;
+}
+
+int sys_dup(int fd, int flags, int* newfd){
+	int ret = syscall(SYS_DUP, fd, flags, -1);
+	if(ret < 0){
+		return -ret;
+	}
+
+	*newfd = ret;
+	return 0;
+}
+
+int sys_dup2(int fd, int flags, int newfd){
+	int ret = syscall(SYS_DUP, fd, flags, newfd);
+	if(ret < 0){
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_fcntl(int fd, int request, va_list args, int* result){
+	if(request == F_DUPFD){
+		return sys_dup(fd, 0, result);
+	} else if (request == F_DUPFD_CLOEXEC) {
+		return sys_dup(fd, O_CLOEXEC, result);
+	} else if(request == F_GETFD){
+		*result = 0;
+		return 0;
+	} else if(request == F_SETFD){
+		if(va_arg(args, int) & FD_CLOEXEC) {
+			return sys_ioctl(fd, FIOCLEX, NULL, result);
+		} else {
+			return sys_ioctl(fd, FIONCLEX, NULL, result);
+		}
+	} else if(request == F_GETFL){
+		int ret = syscall(SYS_GET_FILE_STATUS_FLAGS, fd);
+		if(ret < 0){
+			return -ret;
+		}
+
+		*result = ret;
+		return 0;
+	} else if(request == F_SETFL){
+		int ret = syscall(SYS_SET_FILE_STATUS_FLAGS, fd, va_arg(args, int));
+		return -ret;
+	} else {
+		infoLogger() << "mlibc: sys_fcntl unsupported request (" << request << ")" << frg::endlog;
+		return EINVAL;
+	}
+}
+
+int sys_pselect(int nfds, fd_set* readfds, fd_set* writefds,
+	fd_set *exceptfds, const struct timespec* timeout, const sigset_t* sigmask, int *num_events){
+	int ret = syscall(SYS_SELECT, nfds, readfds, writefds, exceptfds, timeout);
+	if(ret < 0){
+		return -ret;
+	}
+
+	*num_events = ret;
+	return 0;
+}
+
+int sys_chmod(const char *pathname, mode_t mode){
+	int ret = syscall(SYS_CHMOD, pathname, mode);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_pipe(int *fds, int flags){
+	return -syscall(SYS_PIPE, fds, flags);
+}
+
+int sys_epoll_create(int flags, int *fd) {
+	int ret = syscall(SYS_EPOLL_CREATE, flags);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*fd = ret;
+
+	return 0;
+}
+
+int sys_epoll_ctl(int epfd, int mode, int fd, struct epoll_event *ev) {
+	int ret = syscall(SYS_EPOLL_CTL, epfd, mode, fd, ev);
+
+	if(ret < 0) {
+		return -ret;
+	}
+
+	return 0;
+}
+
+int sys_epoll_pwait(int epfd, struct epoll_event *ev, int n,
+		int timeout, const sigset_t *sigmask, int *raised) {
+	int ret = syscall(SYS_EPOLL_WAIT, epfd, ev, n, timeout, sigmask);
+
+	if(ret < 0) {
+		return -ret;
+	}
+
+	*raised = ret;
+
+	return 0;
+}
+
+int sys_ttyname(int tty, char *buf, size_t size) {
+	char path[PATH_MAX] = {"/dev/pts/"};
+
+	struct stat stat;
+	if(int e = sys_stat(fsfd_target::fd, tty, nullptr, 0, &stat)) {
+		return e;
+	}
+
+	if(!S_ISCHR(stat.st_mode)) {
+		return ENOTTY; // Not a char device, isn't a tty
+	}
+
+	if(sys_isatty(tty)) {
+		return ENOTTY;
+	}
+
+	// Look for tty in /dev/pts
+	int ptDir = open("/dev/pts", O_DIRECTORY);
+	__ensure(ptDir >= 0);
+
+	struct dirent dirent;
+	size_t direntBytesRead;
+	while(!sys_read_entries(ptDir, &dirent, sizeof(dirent), &direntBytesRead) && direntBytesRead) {
+		// Compare the inodes
+		if(dirent.d_ino == stat.st_ino) {
+			__ensure(strlen(path) + strlen(dirent.d_name) < PATH_MAX);
+			strcat(path, dirent.d_name);
+
+			strncpy(buf, path, size);
+			return 0;
+		}
+	}
+
+	// Could not find corresponding TTY in /dev/pts
+	return ENODEV;
+}
+
+int sys_fchdir(int fd) {
+	return syscall(SYS_FCHDIR, fd);
+}
+#endif
+
+}
diff --git a/lib/mlibc/sysdeps/lemon/generic/lemon.cpp b/lib/mlibc/sysdeps/lemon/generic/lemon.cpp
new file mode 100644
index 0000000..8f15ff1
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/lemon.cpp
@@ -0,0 +1,199 @@
+#include <lemon/syscall.h>
+#include <stddef.h>
+#include <bits/ensure.h>
+#include <abi-bits/pid_t.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/all-sysdeps.hpp>
+#include <mlibc/thread-entry.hpp>
+#include <errno.h>
+#include <sys/resource.h>
+
+namespace mlibc{
+
+int sys_futex_tid(){
+	return syscall(SYS_GETTID);
+}
+
+int sys_futex_wait(int *pointer, int expected, const struct timespec *time){
+	return syscall(SYS_FUTEX_WAIT, pointer, expected);
+}
+
+int sys_futex_wake(int *pointer) {
+	return syscall(SYS_FUTEX_WAKE, pointer);
+}
+
+int sys_tcb_set(void* pointer){
+	syscall(SYS_SET_FS_BASE, (uintptr_t)pointer);
+	return 0;
+}
+
+int sys_vm_map(void *hint, size_t size, int prot, int flags, int fd, off_t offset, void **window) {
+	__ensure(flags & MAP_ANONYMOUS);
+
+	return syscall(SYS_MMAP, (uintptr_t)window, (size + 0xFFF) & ~static_cast<size_t>(0xFFF), (uintptr_t)hint, flags);
+}
+
+int sys_vm_unmap(void* address, size_t size) {
+	__ensure(!(size & 0xFFF));
+
+	long ret = syscall(SYS_MUNMAP, (uintptr_t)address, (size + 0xFFF) & ~static_cast<size_t>(0xFFF));
+
+	return ret;
+}
+
+int sys_anon_allocate(size_t size, void **pointer) {
+	return sys_vm_map(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS, -1, 0, pointer);
+}
+
+int sys_anon_free(void *pointer, size_t size) {
+	return sys_vm_unmap(pointer, size);
+}
+
+void sys_libc_panic(){
+	sys_libc_log("libc panic!");
+	__builtin_trap();
+	for(;;);
+}
+
+void sys_libc_log(const char* msg){
+	syscall(0, (uintptr_t)msg);
+}
+
+#ifndef MLIBC_BUILDING_RTDL
+
+void sys_exit(int status){
+	syscall(SYS_EXIT, status);
+
+	__builtin_unreachable();
+}
+
+pid_t sys_getpid(){
+	uint64_t _pid;
+	syscall(SYS_GETPID, (uintptr_t)&_pid);
+
+	pid_t pid = _pid;
+	return pid;
+}
+
+pid_t sys_getppid(){
+	return syscall(SYS_GETPPID);
+}
+
+int sys_clock_get(int clock, time_t *secs, long *nanos) {
+	syscall(SYS_UPTIME, nanos);
+
+	*secs = (*nanos) / 1000000000;
+	*nanos = (*nanos) - (*secs) * 1000000000;
+
+	return 0;
+}
+
+int sys_getcwd(char *buffer, size_t size){
+	return syscall(SYS_GET_CWD, buffer, size);
+}
+
+int sys_chdir(const char *path){
+	syscall(SYS_CHDIR, path);
+	return 0;
+}
+
+int sys_sleep(time_t* sec, long* nanosec){
+	syscall(SYS_NANO_SLEEP, (*sec) * 1000000000 + (*nanosec));
+	return 0;
+}
+
+uid_t sys_getuid(){
+	return syscall(SYS_GETUID);
+}
+
+uid_t sys_geteuid(){
+	return syscall(SYS_GETEUID);
+}
+
+int sys_setuid(uid_t uid){
+	return -syscall(SYS_SETUID, uid);
+}
+
+int sys_seteuid(uid_t euid){
+	return -syscall(SYS_SETEUID, euid);
+}
+
+gid_t sys_getgid(){
+	return syscall(SYS_GETGID);
+}
+
+gid_t sys_getegid(){
+	return syscall(SYS_GETEGID);
+}
+
+int sys_setgid(gid_t gid){
+	mlibc::infoLogger() << "mlibc: sys_setgid is a stub" << frg::endlog;
+	return 0;
+}
+
+int sys_setegid(gid_t egid){
+	mlibc::infoLogger() << "mlibc: sys_setegid is a stub" << frg::endlog;
+	return 0;
+}
+
+void sys_yield(){
+	syscall(SYS_YIELD);
+}
+
+int sys_clone(void *tcb, pid_t *tid_out, void *stack){
+	pid_t tid = syscall(SYS_SPAWN_THREAD, __mlibc_start_thread, stack);
+
+	if(tid < 0){
+		errno = tid;
+		return -1;
+	}
+
+	*tid_out = tid;
+
+	return 0;
+}
+
+void sys_thread_exit(){
+	syscall(SYS_EXIT_THREAD);
+
+	__builtin_unreachable();
+}
+
+int sys_waitpid(pid_t pid, int *status, int flags, struct rusage *ru, pid_t *ret_pid){
+	if(ru) {
+		mlibc::infoLogger() << "mlibc: struct rusage in sys_waitpid is unsupported" << frg::endlog;
+		return ENOSYS;
+	}
+
+	pid_t ret = syscall(SYS_WAIT_PID, pid, status, flags);
+
+	if(ret < 0){
+		return -ret;
+	}
+
+	*ret_pid = ret;
+
+	return 0;
+}
+
+int sys_fork(pid_t *child){
+	long pid = syscall(SYS_FORK, 0);
+	if(pid < 0){
+		errno = pid;
+		return -1;
+	}
+
+	*child = pid;
+	return 0;
+}
+
+int sys_execve(const char *path, char *const argv[], char *const envp[]){
+	return -syscall(SYS_EXECVE, path, argv, envp);
+}
+
+int sys_getentropy(void *buffer, size_t length){
+	return -syscall(SYS_GETENTROPY, buffer, length);
+}
+#endif
+
+}
diff --git a/lib/mlibc/sysdeps/lemon/generic/pty.cpp b/lib/mlibc/sysdeps/lemon/generic/pty.cpp
new file mode 100644
index 0000000..794f74f
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/pty.cpp
@@ -0,0 +1,63 @@
+#include <asm/ioctls.h>
+#include <sys/ioctl.h>
+
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/all-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+#include <stdio.h>
+
+namespace mlibc {
+
+int sys_isatty(int fd) {
+	struct winsize ws;
+	long ret = sys_ioctl(fd, TIOCGWINSZ, &ws, 0);
+
+	if(!ret) return 0;
+
+	return ENOTTY;
+}
+
+int sys_tcgetattr(int fd, struct termios *attr) {
+	if(int e = sys_isatty(fd))
+		return e;
+
+	int ret;
+	sys_ioctl(fd, TCGETS, attr, &ret);
+
+	if(ret)
+		return -ret;
+
+	return 0;
+}
+
+int sys_tcsetattr(int fd, int optional_action, const struct termios *attr) {
+	if(int e = sys_isatty(fd))
+		return e;
+
+	if(optional_action){
+		mlibc::infoLogger() << "mlibc warning: sys_tcsetattr ignores optional_action" << frg::endlog;
+	}
+
+	int ret;
+	sys_ioctl(fd, TCSETS, const_cast<struct termios*>(attr), &ret);
+
+	if(ret)
+		return -ret;
+
+	return 0;
+}
+
+int sys_ptsname(int fd, char *buffer, size_t length) {
+	int index;
+	if(int e = sys_ioctl(fd, TIOCGPTN, &index, NULL); e)
+		return e;
+	if((size_t)snprintf(buffer, length, "/dev/pts/%d", index) >= length) {
+		return ERANGE;
+	}
+	return 0;
+}
+
+}
diff --git a/lib/mlibc/sysdeps/lemon/generic/signals.cpp b/lib/mlibc/sysdeps/lemon/generic/signals.cpp
new file mode 100644
index 0000000..46b4714
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/signals.cpp
@@ -0,0 +1,38 @@
+#include <lemon/syscall.h>
+
+#include <sys/types.h>
+
+#include <mlibc/ansi-sysdeps.hpp>
+
+namespace mlibc{
+
+int sys_sigprocmask(int how, const sigset_t *__restrict set,
+	sigset_t *__restrict retrieve){
+    int ret = syscall(SYS_SIGPROCMASK, how, set, retrieve);
+    if(ret < 0){
+        return -ret;
+    }
+
+    return 0;
+}
+
+int sys_sigaction(int signal, const struct sigaction *__restrict action,
+	struct sigaction *__restrict oldAction) {
+    int ret = syscall(SYS_SIGNAL_ACTION, signal, action, oldAction);
+    if(ret < 0){
+        return -ret;
+    }
+
+    return 0;
+}
+
+int sys_kill(int pid, int signal){
+    int ret = syscall(SYS_KILL, pid, signal);
+    if(ret < 0){
+        return -ret;
+    }
+
+    return 0;
+}
+
+}
\ No newline at end of file
diff --git a/lib/mlibc/sysdeps/lemon/generic/sockets.cpp b/lib/mlibc/sysdeps/lemon/generic/sockets.cpp
new file mode 100755
index 0000000..7244218
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/sockets.cpp
@@ -0,0 +1,132 @@
+#include <lemon/syscall.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#include <mlibc/all-sysdeps.hpp>
+
+namespace {
+
+int fcntl_helper(int fd, int request, int *result, ...) {
+	va_list args;
+	va_start(args, result);
+	if(!mlibc::sys_fcntl) {
+		return ENOSYS;
+	}
+	int ret = mlibc::sys_fcntl(fd, request, args, result);
+	va_end(args);
+	return ret;
+}
+
+}
+
+namespace mlibc{
+
+int sys_socket(int domain, int type, int protocol, int *fd){
+    long ret = syscall(SYS_SOCKET, domain, type, protocol);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    *fd = ret;
+
+    return 0;
+}
+
+int sys_bind(int sockfd, const struct sockaddr *addr_ptr, socklen_t addrlen){
+    return syscall(SYS_BIND, sockfd, addr_ptr, addrlen);
+}
+
+int sys_connect(int sockfd, const struct sockaddr *addr_ptr, socklen_t addrlen){
+    return syscall(SYS_CONNECT, sockfd, addr_ptr, addrlen);
+}
+
+int sys_accept(int fd, int *newfd, struct sockaddr *addr_ptr, socklen_t *addr_length, int flags){
+    long ret = syscall(SYS_ACCEPT, fd);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    *newfd = ret;
+
+	if(flags & SOCK_NONBLOCK) {
+		int fcntl_ret = 0;
+		fcntl_helper(*newfd, F_GETFL, &fcntl_ret);
+		fcntl_helper(*newfd, F_SETFL, &fcntl_ret, fcntl_ret | O_NONBLOCK);
+	}
+
+	if(flags & SOCK_CLOEXEC) {
+		int fcntl_ret = 0;
+		fcntl_helper(*newfd, F_GETFD, &fcntl_ret);
+		fcntl_helper(*newfd, F_SETFD, &fcntl_ret, fcntl_ret | FD_CLOEXEC);
+	}
+
+    return 0;
+}
+
+int sys_listen(int fd, int backlog){
+    return syscall(SYS_LISTEN, fd, backlog);
+}
+
+int sys_msg_recv(int sockfd, struct msghdr *hdr, int flags, ssize_t *length){
+    long ret = syscall(SYS_RECVMSG, sockfd, hdr, flags);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    *length = ret;
+
+    return 0;
+}
+
+int sys_msg_send(int sockfd, const struct msghdr *hdr, int flags, ssize_t *length){
+    long ret = syscall(SYS_SENDMSG, sockfd, hdr, flags);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    *length = ret;
+
+    return 0;
+}
+
+int sys_setsockopt(int fd, int layer, int number, const void *buffer, socklen_t size){
+    long ret = syscall(SYS_SET_SOCKET_OPTIONS, fd, layer, number, buffer, size);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    return 0;
+}
+
+int sys_getsockopt(int fd, int layer, int number, void *__restrict buffer, socklen_t *__restrict size){
+    long ret = syscall(SYS_GET_SOCKET_OPTIONS, fd, layer, number, buffer, size);
+
+    if(ret < 0){
+        return -ret;
+    }
+
+    return 0;
+}
+
+int sys_socketpair(int domain, int type_and_flags, int proto, int *fds){
+    return -syscall(SYS_SOCKETPAIR, domain, type_and_flags, proto, fds);
+}
+
+int sys_sockname(int fd, struct sockaddr *addr_ptr, socklen_t max_addr_length,
+    socklen_t *actual_length) {
+    return -syscall(SYS_SOCKNAME, fd, addr_ptr, max_addr_length);
+}
+
+int sys_peername(int fd, struct sockaddr *addr_ptr, socklen_t max_addr_length,
+    socklen_t *actual_length) {
+    return -syscall(SYS_PEERNAME, fd, addr_ptr, max_addr_length);
+}
+
+}
diff --git a/lib/mlibc/sysdeps/lemon/generic/thread.cpp b/lib/mlibc/sysdeps/lemon/generic/thread.cpp
new file mode 100644
index 0000000..42cd758
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/thread.cpp
@@ -0,0 +1,53 @@
+#include <mlibc/thread-entry.hpp>
+#include <mlibc/all-sysdeps.hpp>
+#include <mlibc/tcb.hpp>
+#include <bits/ensure.h>
+#include <sys/mman.h>
+#include <stdint.h>
+#include <stddef.h>
+
+extern "C" void __mlibc_enter_thread(void *entry, void *user_arg, Tcb *tcb) {
+	// Wait until our parent sets up the TID.
+	while(!__atomic_load_n(&tcb->tid, __ATOMIC_RELAXED))
+		mlibc::sys_futex_wait(&tcb->tid, 0, nullptr);
+
+	if(mlibc::sys_tcb_set(tcb))
+		__ensure(!"sys_tcb_set() failed");
+
+	tcb->invokeThreadFunc(entry, user_arg);
+
+	auto self = reinterpret_cast<Tcb *>(tcb);
+
+	__atomic_store_n(&self->didExit, 1, __ATOMIC_RELEASE);
+	mlibc::sys_futex_wake(&self->didExit);
+
+	mlibc::sys_thread_exit();
+}
+
+namespace mlibc {
+
+static constexpr size_t default_stacksize = 0x200000;
+
+int sys_prepare_stack(void **stack, void *entry, void *user_arg, void *tcb, size_t *stack_size, size_t *guard_size, void **stack_base) {
+	if (!*stack_size)
+		*stack_size = default_stacksize;
+	*guard_size = 0;
+
+	if (*stack) {
+		*stack_base = *stack;
+	} else {
+		*stack_base = mmap(nullptr, *stack_size,
+						PROT_READ | PROT_WRITE,
+						MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	}
+	
+	uintptr_t *sp = reinterpret_cast<uintptr_t *>(reinterpret_cast<uintptr_t>(*stack_base) + *stack_size);
+
+	*--sp = reinterpret_cast<uintptr_t>(tcb);
+	*--sp = reinterpret_cast<uintptr_t>(user_arg);
+	*--sp = reinterpret_cast<uintptr_t>(entry);
+	*stack = reinterpret_cast<void*>(sp);
+	return 0;
+}
+
+} //namespace mlibc
diff --git a/lib/mlibc/sysdeps/lemon/generic/thread_entry.S b/lib/mlibc/sysdeps/lemon/generic/thread_entry.S
new file mode 100644
index 0000000..51e703b
--- /dev/null
+++ b/lib/mlibc/sysdeps/lemon/generic/thread_entry.S
@@ -0,0 +1,11 @@
+
+.section .text
+.global __mlibc_start_thread
+__mlibc_start_thread:
+	pop %rdi
+	pop %rsi
+	pop %rdx
+	call __mlibc_enter_thread
+
+.section .note.GNU-stack,"",%progbits
+