d7627467b7
Make do_execve() take a const filename pointer so that kernel_execve() compiles correctly on ARM: arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type This also requires the argv and envp arguments to be consted twice, once for the pointer array and once for the strings the array points to. This is because do_execve() passes a pointer to the filename (now const) to copy_strings_kernel(). A simpler alternative would be to cast the filename pointer in do_execve() when it's passed to copy_strings_kernel(). do_execve() may not change any of the strings it is passed as part of the argv or envp lists as they are some of them in .rodata, so marking these strings as const should be fine. Further kernel_execve() and sys_execve() need to be changed to match. This has been test built on x86_64, frv, arm and mips. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
127 lines
3.1 KiB
C
127 lines
3.1 KiB
C
#include <linux/unistd.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/minix_fs.h>
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#include <linux/ext2_fs.h>
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#include <linux/romfs_fs.h>
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#include <linux/initrd.h>
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#include <linux/sched.h>
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#include <linux/freezer.h>
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#include "do_mounts.h"
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unsigned long initrd_start, initrd_end;
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int initrd_below_start_ok;
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unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
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static int __initdata old_fd, root_fd;
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static int __initdata mount_initrd = 1;
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static int __init no_initrd(char *str)
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{
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mount_initrd = 0;
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return 1;
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}
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__setup("noinitrd", no_initrd);
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static int __init do_linuxrc(void *_shell)
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{
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static const char *argv[] = { "linuxrc", NULL, };
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extern const char *envp_init[];
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const char *shell = _shell;
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sys_close(old_fd);sys_close(root_fd);
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sys_setsid();
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return kernel_execve(shell, argv, envp_init);
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}
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static void __init handle_initrd(void)
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{
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int error;
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int pid;
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real_root_dev = new_encode_dev(ROOT_DEV);
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create_dev("/dev/root.old", Root_RAM0);
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/* mount initrd on rootfs' /root */
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mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
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sys_mkdir("/old", 0700);
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root_fd = sys_open("/", 0, 0);
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old_fd = sys_open("/old", 0, 0);
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/* move initrd over / and chdir/chroot in initrd root */
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sys_chdir("/root");
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sys_mount(".", "/", NULL, MS_MOVE, NULL);
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sys_chroot(".");
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/*
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* In case that a resume from disk is carried out by linuxrc or one of
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* its children, we need to tell the freezer not to wait for us.
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*/
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current->flags |= PF_FREEZER_SKIP;
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pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
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if (pid > 0)
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while (pid != sys_wait4(-1, NULL, 0, NULL))
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yield();
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current->flags &= ~PF_FREEZER_SKIP;
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/* move initrd to rootfs' /old */
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sys_fchdir(old_fd);
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sys_mount("/", ".", NULL, MS_MOVE, NULL);
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/* switch root and cwd back to / of rootfs */
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sys_fchdir(root_fd);
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sys_chroot(".");
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sys_close(old_fd);
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sys_close(root_fd);
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if (new_decode_dev(real_root_dev) == Root_RAM0) {
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sys_chdir("/old");
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return;
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}
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ROOT_DEV = new_decode_dev(real_root_dev);
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mount_root();
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printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
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error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
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if (!error)
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printk("okay\n");
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else {
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int fd = sys_open("/dev/root.old", O_RDWR, 0);
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if (error == -ENOENT)
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printk("/initrd does not exist. Ignored.\n");
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else
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printk("failed\n");
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printk(KERN_NOTICE "Unmounting old root\n");
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sys_umount("/old", MNT_DETACH);
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printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
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if (fd < 0) {
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error = fd;
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} else {
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error = sys_ioctl(fd, BLKFLSBUF, 0);
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sys_close(fd);
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}
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printk(!error ? "okay\n" : "failed\n");
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}
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}
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int __init initrd_load(void)
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{
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if (mount_initrd) {
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create_dev("/dev/ram", Root_RAM0);
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/*
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* Load the initrd data into /dev/ram0. Execute it as initrd
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* unless /dev/ram0 is supposed to be our actual root device,
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* in that case the ram disk is just set up here, and gets
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* mounted in the normal path.
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*/
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if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
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sys_unlink("/initrd.image");
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handle_initrd();
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return 1;
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}
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}
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sys_unlink("/initrd.image");
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return 0;
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}
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