/*
* Copyright (C) 2003-2007 Red Hat, Inc.
*
* This file is part of util-linux.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*
* Written by Elliot Lee <sopwith@redhat.com>
* New personality options & code added by Jindrich Novy <jnovy@redhat.com>
* ADD_NO_RANDOMIZE flag added by Arjan van de Ven <arjanv@redhat.com>
* Help and MIPS support from Mike Frysinger (vapier@gentoo.org)
* Better error handling from Dmitry V. Levin (ldv@altlinux.org)
*
* based on ideas from the ppc32 util by Guy Streeter (2002-01), based on the
* sparc32 util by Jakub Jelinek (1998, 1999)
*/
#include <sys/personality.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <limits.h>
#include <sys/utsname.h>
#include "nls.h"
#include "c.h"
#include "closestream.h"
#ifndef HAVE_PERSONALITY
# include <syscall.h>
# define personality(pers) ((long)syscall(SYS_personality, pers))
#endif
#define turn_on(_flag, _opts) \
do { \
(_opts) |= _flag; \
if (verbose) \
printf(_("Switching on %s.\n"), #_flag); \
} while(0)
#ifndef UNAME26
# define UNAME26 0x0020000
#endif
#ifndef ADDR_NO_RANDOMIZE
# define ADDR_NO_RANDOMIZE 0x0040000
#endif
#ifndef FDPIC_FUNCPTRS
# define FDPIC_FUNCPTRS 0x0080000
#endif
#ifndef MMAP_PAGE_ZERO
# define MMAP_PAGE_ZERO 0x0100000
#endif
#ifndef ADDR_COMPAT_LAYOUT
# define ADDR_COMPAT_LAYOUT 0x0200000
#endif
#ifndef READ_IMPLIES_EXEC
# define READ_IMPLIES_EXEC 0x0400000
#endif
#ifndef ADDR_LIMIT_32BIT
# define ADDR_LIMIT_32BIT 0x0800000
#endif
#ifndef SHORT_INODE
# define SHORT_INODE 0x1000000
#endif
#ifndef WHOLE_SECONDS
# define WHOLE_SECONDS 0x2000000
#endif
#ifndef STICKY_TIMEOUTS
# define STICKY_TIMEOUTS 0x4000000
#endif
#ifndef ADDR_LIMIT_3GB
# define ADDR_LIMIT_3GB 0x8000000
#endif
struct arch_domain {
int perval; /* PER_* */
const char *target_arch;
const char *result_arch;
};
static void __attribute__((__noreturn__)) usage(int archwrapper)
{
fputs(USAGE_HEADER, stdout);
if (!archwrapper)
printf(_(" %s [<arch>] [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
else
printf(_(" %s [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, stdout);
fputs(_("Change the reported architecture and set personality flags.\n"), stdout);
fputs(USAGE_OPTIONS, stdout);
fputs(_(" -B, --32bit turns on ADDR_LIMIT_32BIT\n"), stdout);
fputs(_(" -F, --fdpic-funcptrs makes function pointers point to descriptors\n"), stdout);
fputs(_(" -I, --short-inode turns on SHORT_INODE\n"), stdout);
fputs(_(" -L, --addr-compat-layout changes the way virtual memory is allocated\n"), stdout);
fputs(_(" -R, --addr-no-randomize disables randomization of the virtual address space\n"), stdout);
fputs(_(" -S, --whole-seconds turns on WHOLE_SECONDS\n"), stdout);
fputs(_(" -T, --sticky-timeouts turns on STICKY_TIMEOUTS\n"), stdout);
fputs(_(" -X, --read-implies-exec turns on READ_IMPLIES_EXEC\n"), stdout);
fputs(_(" -Z, --mmap-page-zero turns on MMAP_PAGE_ZERO\n"), stdout);
fputs(_(" -3, --3gb limits the used address space to a maximum of 3 GB\n"), stdout);
fputs(_(" --4gb ignored (for backward compatibility only)\n"), stdout);
fputs(_(" --uname-2.6 turns on UNAME26\n"), stdout);
fputs(_(" -v, --verbose say what options are being switched on\n"), stdout);
if (!archwrapper)
fputs(_(" --list list settable architectures, and exit\n"), stdout);
fputs(USAGE_SEPARATOR, stdout);
printf(USAGE_HELP_OPTIONS(26));
printf(USAGE_MAN_TAIL("setarch(8)"));
exit(EXIT_SUCCESS);
}
/*
* Returns inilialized list of all available execution domains.
*/
static struct arch_domain *init_arch_domains(void)
{
static struct utsname un;
size_t i;
static struct arch_domain transitions[] =
{
{UNAME26, "uname26", NULL},
{PER_LINUX32, "linux32", NULL},
{PER_LINUX, "linux64", NULL},
#if defined(__powerpc__) || defined(__powerpc64__)
# ifdef __BIG_ENDIAN__
{PER_LINUX32, "ppc32", "ppc"},
{PER_LINUX32, "ppc", "ppc"},
{PER_LINUX, "ppc64", "ppc64"},
{PER_LINUX, "ppc64pseries", "ppc64"},
{PER_LINUX, "ppc64iseries", "ppc64"},
# else
{PER_LINUX32, "ppc32", "ppcle"},
{PER_LINUX32, "ppc", "ppcle"},
{PER_LINUX32, "ppc32le", "ppcle"},
{PER_LINUX32, "ppcle", "ppcle"},
{PER_LINUX, "ppc64le", "ppc64le"},
# endif
#endif
#if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
{PER_LINUX32, "i386", "i386"},
{PER_LINUX32, "i486", "i386"},
{PER_LINUX32, "i586", "i386"},
{PER_LINUX32, "i686", "i386"},
{PER_LINUX32, "athlon", "i386"},
#endif
#if defined(__x86_64__) || defined(__i386__)
{PER_LINUX, "x86_64", "x86_64"},
#endif
#if defined(__ia64__) || defined(__i386__)
{PER_LINUX, "ia64", "ia64"},
#endif
#if defined(__hppa__)
{PER_LINUX32, "parisc32", "parisc"},
{PER_LINUX32, "parisc", "parisc"},
{PER_LINUX, "parisc64", "parisc64"},
#endif
#if defined(__s390x__) || defined(__s390__)
{PER_LINUX32, "s390", "s390"},
{PER_LINUX, "s390x", "s390x"},
#endif
#if defined(__sparc64__) || defined(__sparc__)
{PER_LINUX32, "sparc", "sparc"},
{PER_LINUX32, "sparc32bash", "sparc"},
{PER_LINUX32, "sparc32", "sparc"},
{PER_LINUX, "sparc64", "sparc64"},
#endif
#if defined(__mips64__) || defined(__mips__)
{PER_LINUX32, "mips32", "mips"},
{PER_LINUX32, "mips", "mips"},
{PER_LINUX, "mips64", "mips64"},
#endif
#if defined(__alpha__)
{PER_LINUX, "alpha", "alpha"},
{PER_LINUX, "alphaev5", "alpha"},
{PER_LINUX, "alphaev56", "alpha"},
{PER_LINUX, "alphaev6", "alpha"},
{PER_LINUX, "alphaev67", "alpha"},
#endif
#if defined(__e2k__)
{PER_LINUX, "e2k", "e2k"},
{PER_LINUX, "e2kv4", "e2k"},
{PER_LINUX, "e2kv5", "e2k"},
{PER_LINUX, "e2kv6", "e2k"},
{PER_LINUX, "e2k4c", "e2k"},
{PER_LINUX, "e2k8c", "e2k"},
{PER_LINUX, "e2k1cp", "e2k"},
{PER_LINUX, "e2k8c2", "e2k"},
{PER_LINUX, "e2k12c", "e2k"},
{PER_LINUX, "e2k16c", "e2k"},
{PER_LINUX, "e2k2c3", "e2k"},
#endif
/* place holder, will be filled up at runtime */
{-1, NULL, NULL},
{-1, NULL, NULL}
};
/* Add the trivial transition {PER_LINUX, machine, machine} if no
* such target_arch is hardcoded yet. */
uname(&un);
for (i = 0; transitions[i].perval >= 0; i++)
if (!strcmp(un.machine, transitions[i].target_arch))
break;
if (transitions[i].perval < 0) {
unsigned long wrdsz = CHAR_BIT * sizeof(void *);
if (wrdsz == 32 || wrdsz == 64) {
/* fill up the place holder */
transitions[i].perval = wrdsz == 32 ? PER_LINUX32 : PER_LINUX;
transitions[i].target_arch = un.machine;
transitions[i].result_arch = un.machine;
}
}
return transitions;
}
/*
* List all execution domains from transitions
*/
static void list_arch_domains(struct arch_domain *doms)
{
struct arch_domain *d;
for (d = doms; d->target_arch != NULL; d++)
printf("%s\n", d->target_arch);
}
static struct arch_domain *get_arch_domain(struct arch_domain *doms, const char *pers)
{
struct arch_domain *d;
for (d = doms; d && d->perval >= 0; d++) {
if (!strcmp(pers, d->target_arch))
break;
}
return !d || d->perval < 0 ? NULL : d;
}
static void verify_arch_domain(struct arch_domain *dom, const char *wanted)
{
struct utsname un;
if (!dom || !dom->result_arch)
return;
uname(&un);
if (strcmp(un.machine, dom->result_arch)) {
if (strcmp(dom->result_arch, "i386")
|| (strcmp(un.machine, "i486")
&& strcmp(un.machine, "i586")
&& strcmp(un.machine, "i686")
&& strcmp(un.machine, "athlon")))
errx(EXIT_FAILURE, _("Kernel cannot set architecture to %s"), wanted);
}
}
int main(int argc, char *argv[])
{
const char *arch = NULL;
unsigned long options = 0;
int verbose = 0;
int archwrapper;
int c;
struct arch_domain *doms, *target = NULL;
unsigned long pers_value = 0;
char *shell = NULL, *shell_arg = NULL;
/* Options without equivalent short options */
enum {
OPT_4GB = CHAR_MAX + 1,
OPT_UNAME26,
OPT_LIST
};
/* Options --3gb and --4gb are for compatibility with an old
* Debian setarch implementation. */
static const struct option longopts[] = {
{"help", no_argument, NULL, 'h'},
{"version", no_argument, NULL, 'V'},
{"verbose", no_argument, NULL, 'v'},
{"addr-no-randomize", no_argument, NULL, 'R'},
{"fdpic-funcptrs", no_argument, NULL, 'F'},
{"mmap-page-zero", no_argument, NULL, 'Z'},
{"addr-compat-layout", no_argument, NULL, 'L'},
{"read-implies-exec", no_argument, NULL, 'X'},
{"32bit", no_argument, NULL, 'B'},
{"short-inode", no_argument, NULL, 'I'},
{"whole-seconds", no_argument, NULL, 'S'},
{"sticky-timeouts", no_argument, NULL, 'T'},
{"3gb", no_argument, NULL, '3'},
{"4gb", no_argument, NULL, OPT_4GB},
{"uname-2.6", no_argument, NULL, OPT_UNAME26},
{"list", no_argument, NULL, OPT_LIST},
{NULL, 0, NULL, 0}
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
if (argc < 1) {
warnx(_("Not enough arguments"));
errtryhelp(EXIT_FAILURE);
}
archwrapper = strcmp(program_invocation_short_name, "setarch") != 0;
if (archwrapper) {
arch = program_invocation_short_name; /* symlinks to setarch */
/* Don't use ifdef sparc here, we get "Unrecognized architecture"
* error message later if necessary */
if (strcmp(arch, "sparc32bash") == 0) {
shell = "/bin/bash";
shell_arg = "";
goto set_arch;
}
} else {
if (1 < argc && *argv[1] != '-') {
arch = argv[1];
argv[1] = argv[0]; /* for getopt_long() to get the program name */
argv++;
argc--;
}
}
while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
switch (c) {
case 'v':
verbose = 1;
break;
case 'R':
turn_on(ADDR_NO_RANDOMIZE, options);
break;
case 'F':
turn_on(FDPIC_FUNCPTRS, options);
break;
case 'Z':
turn_on(MMAP_PAGE_ZERO, options);
break;
case 'L':
turn_on(ADDR_COMPAT_LAYOUT, options);
break;
case 'X':
turn_on(READ_IMPLIES_EXEC, options);
break;
case 'B':
turn_on(ADDR_LIMIT_32BIT, options);
break;
case 'I':
turn_on(SHORT_INODE, options);
break;
case 'S':
turn_on(WHOLE_SECONDS, options);
break;
case 'T':
turn_on(STICKY_TIMEOUTS, options);
break;
case '3':
turn_on(ADDR_LIMIT_3GB, options);
break;
case OPT_4GB: /* just ignore this one */
break;
case OPT_UNAME26:
turn_on(UNAME26, options);
break;
case OPT_LIST:
if (!archwrapper) {
list_arch_domains(init_arch_domains());
return EXIT_SUCCESS;
} else
warnx(_("unrecognized option '--list'"));
/* fallthrough */
default:
errtryhelp(EXIT_FAILURE);
case 'h':
usage(archwrapper);
case 'V':
print_version(EXIT_SUCCESS);
}
}
if (!arch && !options)
errx(EXIT_FAILURE, _("no architecture argument or personality flags specified"));
argc -= optind;
argv += optind;
set_arch:
/* get execution domain (architecture) */
if (arch) {
doms = init_arch_domains();
target = get_arch_domain(doms, arch);
if (!target)
errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), arch);
pers_value = target->perval;
}
/* add personality flags */
pers_value |= options;
/* call kernel */
if (personality(pers_value) < 0) {
/*
* Depending on architecture and kernel version, personality
* syscall is either capable or incapable of returning an error.
* If the return value is not an error, then it's the previous
* personality value, which can be an arbitrary value
* undistinguishable from an error value.
* To make things clear, a second call is needed.
*/
if (personality(pers_value) < 0)
err(EXIT_FAILURE, _("failed to set personality to %s"), arch);
}
/* make sure architecture is set as expected */
if (arch)
verify_arch_domain(target, arch);
if (!argc) {
shell = "/bin/sh";
shell_arg = "-sh";
}
if (verbose) {
printf(_("Execute command `%s'.\n"), shell ? shell : argv[0]);
/* flush all output streams before exec */
fflush(NULL);
}
/* Execute shell */
if (shell) {
execl(shell, shell_arg, NULL);
errexec(shell);
}
/* Execute on command line specified command */
execvp(argv[0], argv);
errexec(argv[0]);
}
