don't bother with kernel_thread/kernel_execve for launching linuxrc

exec_usermodehelper_fns() will do just fine...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-02 15:29:10 -04:00
parent cb450766bc
commit ba4df2808a

View File

@ -16,13 +16,13 @@
#include <linux/initrd.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kmod.h>
#include "do_mounts.h"
unsigned long initrd_start, initrd_end;
int initrd_below_start_ok;
unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
static int __initdata old_fd, root_fd;
static int __initdata mount_initrd = 1;
static int __init no_initrd(char *str)
@ -33,33 +33,29 @@ static int __init no_initrd(char *str)
__setup("noinitrd", no_initrd);
static int __init do_linuxrc(void *_shell)
static int init_linuxrc(struct subprocess_info *info, struct cred *new)
{
static const char *argv[] = { "linuxrc", NULL, };
extern const char *envp_init[];
const char *shell = _shell;
sys_close(old_fd);sys_close(root_fd);
sys_unshare(CLONE_FS | CLONE_FILES);
/* move initrd over / and chdir/chroot in initrd root */
sys_chdir("/root");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
sys_setsid();
return kernel_execve(shell, argv, envp_init);
return 0;
}
static void __init handle_initrd(void)
{
static char *argv[] = { "linuxrc", NULL, };
extern char *envp_init[];
int error;
int pid;
real_root_dev = new_encode_dev(ROOT_DEV);
create_dev("/dev/root.old", Root_RAM0);
/* mount initrd on rootfs' /root */
mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
sys_mkdir("/old", 0700);
root_fd = sys_open("/", 0, 0);
old_fd = sys_open("/old", 0, 0);
/* move initrd over / and chdir/chroot in initrd root */
sys_chdir("/root");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
sys_chdir("/old");
/*
* In case that a resume from disk is carried out by linuxrc or one of
@ -67,27 +63,22 @@ static void __init handle_initrd(void)
*/
current->flags |= PF_FREEZER_SKIP;
pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
if (pid > 0)
while (pid != sys_wait4(-1, NULL, 0, NULL))
yield();
call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC,
init_linuxrc, NULL, NULL);
current->flags &= ~PF_FREEZER_SKIP;
/* move initrd to rootfs' /old */
sys_fchdir(old_fd);
sys_mount("/", ".", NULL, MS_MOVE, NULL);
sys_mount("..", ".", NULL, MS_MOVE, NULL);
/* switch root and cwd back to / of rootfs */
sys_fchdir(root_fd);
sys_chroot(".");
sys_close(old_fd);
sys_close(root_fd);
sys_chroot("..");
if (new_decode_dev(real_root_dev) == Root_RAM0) {
sys_chdir("/old");
return;
}
sys_chdir("/");
ROOT_DEV = new_decode_dev(real_root_dev);
mount_root();