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-rw-r--r--sys/include/sys/exec.h37
-rw-r--r--sys/include/sys/syscall.h1
-rw-r--r--sys/kern/kern_exec.c234
-rw-r--r--sys/kern/kern_syscall.c2
4 files changed, 274 insertions, 0 deletions
diff --git a/sys/include/sys/exec.h b/sys/include/sys/exec.h
new file mode 100644
index 0000000..5832a3f
--- /dev/null
+++ b/sys/include/sys/exec.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * 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.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
+ */
+
+#ifndef _SYS_EXEC_H_
+#define _SYS_EXEC_H_
+
+#include <sys/syscall.h>
+
+uint64_t sys_execv(struct syscall_args *args);
+
+#endif
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 0f5abf0..a2ca992 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -46,6 +46,7 @@ enum {
SYS_mmap,
SYS_munmap,
SYS_ioctl,
+ SYS_execv,
__MAX_SYSCALLS
};
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
new file mode 100644
index 0000000..b5b4cd2
--- /dev/null
+++ b/sys/kern/kern_exec.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * 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.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 <sys/sched.h>
+#include <sys/system.h>
+#include <sys/errno.h>
+#include <sys/vfs.h>
+#include <sys/exec.h>
+#include <sys/filedesc.h>
+#include <sys/signal.h>
+#include <sys/loader.h>
+#include <sys/cdefs.h>
+#include <vm/dynalloc.h>
+#include <sys/syslog.h>
+#include <string.h>
+
+__MODULE_NAME("exec");
+__KERNEL_META("$Hyra$: kern_exec.c, Ian Marco Moffett, "
+ "exec() implementation");
+
+#define ARG_MAX 1024
+
+/*
+ * Allocates a buffer in in `res' and fetches
+ * the args from `argv'
+ *
+ * @argv: User argv
+ * @res: Exec args result.
+ *
+ * XXX: res->argp is dynamically allocated, remember
+ * to free it!
+ */
+static int
+exec_get_args(char **argv, struct exec_args *res)
+{
+ const size_t ARG_LEN = sizeof(char) * ARG_MAX;
+ char *argp = NULL;
+
+ struct proc *td;
+ size_t argp_len = 0;
+
+ if (res == NULL)
+ return -EINVAL;
+
+ /* Allocate argp */
+ res->argp = dynalloc(ARG_LEN);
+ if (res->argp == NULL)
+ return -ENOMEM;
+
+ td = this_td();
+ res->vas = td->addrsp;
+
+ /* Read argv */
+ copyin((uintptr_t)argv, &argp, sizeof(char *));
+ for (;;) {
+ if (argp == NULL) {
+ res->argp[argp_len] = NULL;
+ break;
+ }
+
+ /* Fetch this arg and get next argp */
+ copyinstr((uintptr_t)argp, res->argp[argp_len++], ARG_MAX);
+ copyin((uintptr_t)++argv, &argp, sizeof(char *));
+
+ /* Try to resize the argp buffer */
+ res->argp = dynrealloc(res->argp, ARG_LEN * (argp_len + 1));
+ if (res->argp == NULL) {
+ dynfree(res->argp);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Reset the stack of the process.
+ *
+ * @td: Target thread.
+ * @args: Exec args.
+ *
+ * Returns the new stack pointer.
+ */
+static uintptr_t
+exec_set_stack(struct proc *td, struct exec_args args)
+{
+ struct vm_range *stack_range;
+ uintptr_t stack_top, sp;
+
+ stack_range = &td->addr_range[ADDR_RANGE_STACK];
+ stack_top = stack_range->start + (PROC_STACK_SIZE);
+
+ sp = sched_init_stack((void *)stack_top, args);
+ return sp;
+}
+
+/*
+ * execv() implementation.
+ *
+ * @pathname: Path of file to execute.
+ * @argv: Args.
+ * @sp_res: Pointer to new stack pointer
+ */
+static int
+execv(char *pathname, char **argv, uintptr_t *sp_res)
+{
+ char *bin;
+ struct filedesc *filedes;
+ struct vm_range *exec_range;
+ struct exec_args args;
+
+ struct proc *td = this_td();
+ int fd, ret = 0;
+ int status;
+ size_t bin_size;
+
+ if ((status = exec_get_args(argv, &args)) != 0)
+ return status;
+
+ spinlock_acquire(&td->lock);
+ fd = open(pathname, O_RDONLY);
+
+ if (fd < 0) {
+ ret = -ENOENT;
+ goto done;
+ }
+
+ filedes = fd_from_fdnum(td, fd);
+ if (__unlikely(filedes == NULL)) {
+ /*
+ * Should not happen. The kernel might be in some
+ * erroneous state.
+ */
+ ret = -EIO;
+ goto done;
+ }
+
+ lseek(fd, 0, SEEK_END);
+ bin_size = filedes->offset;
+ lseek(fd, 0, SEEK_SET);
+
+ /* Allocate memory for the binary */
+ bin = dynalloc(bin_size);
+ if (bin == NULL) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ /* Read-in the binary */
+ if ((status = read(fd, bin, bin_size)) < 0) {
+ ret = status;
+ goto done;
+ }
+
+ /*
+ * Unload the current process image. After we do this,
+ * we cannot return in this state until we replace it.
+ *
+ * XXX: This is one of the last things we do in case of
+ * errors.
+ */
+ exec_range = &td->addr_range[ADDR_RANGE_EXEC];
+ loader_unload(td->addrsp, exec_range);
+
+ /*
+ * Now we try to load the new program and hope everything
+ * works... If something goes wrong here then we'll be forced
+ * to send a SIGSEGV to the thread.
+ */
+ status = loader_load(td->addrsp, bin, &args.auxv, 0, NULL, exec_range);
+ if (status != 0) {
+ /* Well shit */
+ KERR("Failed to load new process image\n");
+ signal_raise(td, SIGSEGV);
+ for (;;);
+ }
+
+ *sp_res = exec_set_stack(td, args);
+ set_frame_ip(td->tf, args.auxv.at_entry);
+done:
+ /* We are done, free argp and release the thread */
+ spinlock_release(&td->lock);
+ dynfree(args.argp);
+ return ret;
+}
+
+/*
+ * Arg0: Pathname
+ * Arg1: Argv
+ */
+uint64_t
+sys_execv(struct syscall_args *args)
+{
+ uintptr_t sp;
+ char pathname[PATH_MAX];
+ char **argv = (char **)args->arg1;
+
+ int status;
+ struct proc *td = this_td();
+
+ copyinstr(args->arg0, pathname, PATH_MAX);
+ if ((status = execv(pathname, argv, &sp)) != 0)
+ return status;
+
+ args->ip = get_frame_ip(td->tf);
+ args->sp = sp;
+ return 0;
+}
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index b575346..0461977 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -33,6 +33,7 @@
#include <sys/types.h>
#include <sys/filedesc.h>
#include <sys/system.h>
+#include <sys/exec.h>
#include <vm/map.h>
uint64_t(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args) = {
@@ -45,4 +46,5 @@ uint64_t(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args) = {
sys_mmap,
sys_munmap,
sys_ioctl,
+ sys_execv,
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 00:44:06 +0000