* pivot_root.c - Change root file system. Based on util-linux 2.10s
*
* busyboxed by Evin Robertson
+ * pivot_root syscall stubbed by Erik Andersen, so it will compile
+ * regardless of the kernel being used.
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include <stdlib.h>
-#include <stdio.h>
-#include <sys/syscall.h>
-#include <linux/unistd.h>
-#include "busybox.h"
-
-#ifndef __NR_pivot_root
-#error Sorry, but this kernel does not support the pivot_root syscall
-#endif
-
-static _syscall2(int,pivot_root,const char *,new_root,const char *,put_old)
-
-
+//config:config PIVOT_ROOT
+//config: bool "pivot_root (1.1 kb)"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: The pivot_root utility swaps the mount points for the root filesystem
+//config: with some other mounted filesystem. This allows you to do all sorts
+//config: of wild and crazy things with your Linux system and is far more
+//config: powerful than 'chroot'.
+//config:
+//config: Note: This is for initrd in linux 2.4. Under initramfs (introduced
+//config: in linux 2.6) use switch_root instead.
+
+//applet:IF_PIVOT_ROOT(APPLET_NOFORK(pivot_root, pivot_root, BB_DIR_SBIN, BB_SUID_DROP, pivot_root))
+
+//kbuild:lib-$(CONFIG_PIVOT_ROOT) += pivot_root.o
+
+//usage:#define pivot_root_trivial_usage
+//usage: "NEW_ROOT PUT_OLD"
+//usage:#define pivot_root_full_usage "\n\n"
+//usage: "Move the current root file system to PUT_OLD and make NEW_ROOT\n"
+//usage: "the new root file system"
+
+#include "libbb.h"
+
+extern int pivot_root(const char *new_root, const char *put_old);
+
+int pivot_root_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int pivot_root_main(int argc, char **argv)
{
- if (argc != 3)
- show_usage();
+ if (argc != 3)
+ bb_show_usage();
- if (pivot_root(argv[1],argv[2]) < 0)
- perror_msg_and_die("pivot_root");
+ /* NOFORK applet. Hardly matters wrt performance, but code is trivial */
- return EXIT_SUCCESS;
+ if (pivot_root(argv[1], argv[2]) < 0) {
+ /* prints "pivot_root: <strerror text>" */
+ bb_perror_nomsg_and_die();
+ }
+ return EXIT_SUCCESS;
}
-
-
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/