source: MondoRescue/branches/3.3/mindi-busybox/util-linux/setarch.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * linux32/linux64 allows for changing uname emulation.
 *
 * Copyright 2002 Andi Kleen, SuSE Labs.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config SETARCH
//config:   bool "setarch"
//config:   default y
//config:   select PLATFORM_LINUX
//config:   help
//config:     The linux32 utility is used to create a 32bit environment for the
//config:     specified program (usually a shell). It only makes sense to have
//config:     this util on a system that supports both 64bit and 32bit userland
//config:     (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...).

//applet:IF_SETARCH(APPLET(setarch, BB_DIR_BIN, BB_SUID_DROP))
//applet:IF_SETARCH(APPLET_ODDNAME(linux32, setarch, BB_DIR_BIN, BB_SUID_DROP, linux32))
//applet:IF_SETARCH(APPLET_ODDNAME(linux64, setarch, BB_DIR_BIN, BB_SUID_DROP, linux64))

//kbuild:lib-$(CONFIG_SETARCH) += setarch.o

//usage:#define setarch_trivial_usage
//usage:       "PERSONALITY [-R] PROG ARGS"
//usage:#define setarch_full_usage "\n\n"
//usage:       "PERSONALITY may be:"
//usage:   "\n""    linux32 Set 32bit uname emulation"
//usage:   "\n""    linux64 Set 64bit uname emulation"
//usage:   "\n"
//usage:   "\n""    -R  Disable address space randomization"
//usage:
//usage:#define linux32_trivial_usage NOUSAGE_STR
//usage:#define linux32_full_usage ""
//usage:
//usage:#define linux64_trivial_usage NOUSAGE_STR
//usage:#define linux64_full_usage ""

#include "libbb.h"
#include <sys/personality.h>

#ifndef ADDR_NO_RANDOMIZE
# define ADDR_NO_RANDOMIZE       0x0040000
#endif

int setarch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int setarch_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned opts;
    unsigned long pers;

    /* Figure out what personality we are supposed to switch to ...
     * we can be invoked as either:
     * argv[0],argv[1] == "setarch","personality"
     * argv[0]         == "personality"
     */
    if (ENABLE_SETARCH && applet_name[0] == 's'
     && argv[1] && is_prefixed_with(argv[1], "linux")
    ) {
        applet_name = argv[1];
        argv++;
    }
    if (applet_name[5] == '6') /* linux64 */
        pers = PER_LINUX;
    else if (applet_name[5] == '3') /* linux32 */
        pers = PER_LINUX32;
    else
        bb_show_usage();

    opts = getopt32(argv, "+R"); /* '+': stop at first non-option */
    if (opts)
        pers |= ADDR_NO_RANDOMIZE;

    /* Try to set personality */
    if (personality(pers) < 0)
        bb_perror_msg_and_die("personality(0x%lx)", pers);

    argv += optind;
    if (!argv[0])
        (--argv)[0] = (char*)"/bin/sh";

    /* Try to execute the program */
    BB_EXECVP_or_die(argv);
}