53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* pivot_root.c - Change root file system. Based on util-linux 2.10s
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*
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* busyboxed by Evin Robertson
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* pivot_root syscall stubbed by Erik Andersen, so it will compile
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* regardless of the kernel being used.
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config PIVOT_ROOT
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//config: bool "pivot_root (898 bytes)"
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//config: default y
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//config: select PLATFORM_LINUX
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//config: help
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//config: The pivot_root utility swaps the mount points for the root filesystem
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//config: with some other mounted filesystem. This allows you to do all sorts
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//config: of wild and crazy things with your Linux system and is far more
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//config: powerful than 'chroot'.
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//config:
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//config: Note: This is for initrd in linux 2.4. Under initramfs (introduced
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//config: in linux 2.6) use switch_root instead.
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//applet:IF_PIVOT_ROOT(APPLET_NOFORK(pivot_root, pivot_root, BB_DIR_SBIN, BB_SUID_DROP, pivot_root))
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//kbuild:lib-$(CONFIG_PIVOT_ROOT) += pivot_root.o
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//usage:#define pivot_root_trivial_usage
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//usage: "NEW_ROOT PUT_OLD"
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//usage:#define pivot_root_full_usage "\n\n"
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//usage: "Move the current root file system to PUT_OLD and make NEW_ROOT\n"
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//usage: "the new root file system"
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#include "libbb.h"
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extern int pivot_root(const char *new_root, const char *put_old);
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int pivot_root_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int pivot_root_main(int argc, char **argv)
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{
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if (argc != 3)
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bb_show_usage();
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/* NOFORK applet. Hardly matters wrt performance, but code is trivial */
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if (pivot_root(argv[1], argv[2]) < 0) {
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/* prints "pivot_root: <strerror text>" */
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bb_perror_nomsg_and_die();
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}
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return EXIT_SUCCESS;
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}
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