sys-utils/setarch.c

   1 /*
   2  * Copyright (C) 2003-2007 Red Hat, Inc.
   3  *
   4  * This file is part of util-linux.
   5  *
   6  * This file is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This file is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  *
  17  * Written by Elliot Lee <sopwith@redhat.com>
  18  * New personality options & code added by Jindrich Novy <jnovy@redhat.com>
  19  * ADD_NO_RANDOMIZE flag added by Arjan van de Ven <arjanv@redhat.com>
  20  * Help and MIPS support from Mike Frysinger (vapier@gentoo.org)
  21  * Better error handling from Dmitry V. Levin (ldv@altlinux.org)
  22  *
  23  * based on ideas from the ppc32 util by Guy Streeter (2002-01), based on the
  24  * sparc32 util by Jakub Jelinek (1998, 1999)
  25  */
  26
  27 #include <syscall.h>
  28 #include <linux/personality.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <stdlib.h>
  33 #include <getopt.h>
  34 #include <limits.h>
  35 #include <sys/utsname.h>
  36 #include "nls.h"
  37 #include "c.h"
  38 #include "closestream.h"
  39
  40 #define set_pers(pers) ((long)syscall(SYS_personality, pers))
  41
  42 /* Options without equivalent short options */
  43 enum {
  44         OPT_4GB         = CHAR_MAX + 1,
  45         OPT_UNAME26
  46 };
  47
  48 #define turn_on(_flag, _opts) \
  49         do { \
  50                 (_opts) |= _flag; \
  51                 if (verbose) \
  52                         printf(_("Switching on %s.\n"), #_flag); \
  53         } while(0)
  54
  55
  56 #if !HAVE_DECL_UNAME26
  57 # define UNAME26                 0x0020000
  58 #endif
  59 #if !HAVE_DECL_ADDR_NO_RANDOMIZE
  60 # define ADDR_NO_RANDOMIZE       0x0040000
  61 #endif
  62 #if !HAVE_DECL_FDPIC_FUNCPTRS
  63 # define FDPIC_FUNCPTRS          0x0080000
  64 #endif
  65 #if !HAVE_DECL_MMAP_PAGE_ZERO
  66 # define MMAP_PAGE_ZERO          0x0100000
  67 #endif
  68 #if !HAVE_DECL_ADDR_COMPAT_LAYOUT
  69 # define ADDR_COMPAT_LAYOUT      0x0200000
  70 #endif
  71 #if !HAVE_DECL_READ_IMPLIES_EXEC
  72 # define READ_IMPLIES_EXEC       0x0400000
  73 #endif
  74 #if !HAVE_DECL_ADDR_LIMIT_32BIT
  75 # define ADDR_LIMIT_32BIT        0x0800000
  76 #endif
  77 #if !HAVE_DECL_SHORT_INODE
  78 # define SHORT_INODE             0x1000000
  79 #endif
  80 #if !HAVE_DECL_WHOLE_SECONDS
  81 # define WHOLE_SECONDS           0x2000000
  82 #endif
  83 #if !HAVE_DECL_STICKY_TIMEOUTS
  84 # define STICKY_TIMEOUTS         0x4000000
  85 #endif
  86 #if !HAVE_DECL_ADDR_LIMIT_3GB
  87 # define ADDR_LIMIT_3GB          0x8000000
  88 #endif
  89
  90 static void __attribute__((__noreturn__))
  91 show_help(void)
  92 {
  93    printf(USAGE_HEADER);
  94    printf(_(" %s%s [options] [program [program arguments]]\n"),
  95          program_invocation_short_name,
  96          !strcmp(program_invocation_short_name, "setarch") ? " <arch>" : "");
  97
  98    printf(USAGE_OPTIONS);
  99    printf(_(
 100    " -v, --verbose            says what options are being switched on\n"
 101    " -R, --addr-no-randomize  disables randomization of the virtual address space\n"
 102    " -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"
 103    " -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"
 104    " -L, --addr-compat-layout changes the way virtual memory is allocated\n"
 105    " -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"
 106    " -B, --32bit              turns on ADDR_LIMIT_32BIT\n"
 107    " -I, --short-inode        turns on SHORT_INODE\n"
 108    " -S, --whole-seconds      turns on WHOLE_SECONDS\n"
 109    " -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"
 110    " -3, --3gb                limits the used address space to a maximum of 3 GB\n"
 111    "     --4gb                ignored (for backward compatibility only)\n"
 112    "     --uname-2.6          turns on UNAME26\n"));
 113
 114   printf(USAGE_SEPARATOR);
 115   printf(USAGE_HELP);
 116   printf(USAGE_VERSION);
 117   printf(USAGE_MAN_TAIL("setarch(8)"));
 118
 119   exit(EXIT_SUCCESS);
 120 }
 121
 122 static void __attribute__((__noreturn__))
 123 show_usage(const char *s)
 124 {
 125   errx(EXIT_FAILURE, _("%s\nTry `%s --help' for more information."), s, program_invocation_short_name);
 126 }
 127
 128 static void __attribute__((__noreturn__))
 129 show_version(void)
 130 {
 131   printf(UTIL_LINUX_VERSION);
 132   exit(EXIT_SUCCESS);
 133 }
 134
 135 int set_arch(const char *pers, unsigned long options)
 136 {
 137   struct utsname un;
 138   int i;
 139   unsigned long pers_value;
 140
 141   struct {
 142     int perval;
 143     const char *target_arch, *result_arch;
 144   } transitions[] = {
 145     {PER_LINUX32, "linux32", NULL},
 146     {PER_LINUX, "linux64", NULL},
 147 #if defined(__powerpc__) || defined(__powerpc64__)
 148     {PER_LINUX32, "ppc32", "ppc"},
 149     {PER_LINUX32, "ppc", "ppc"},
 150     {PER_LINUX, "ppc64", "ppc64"},
 151     {PER_LINUX, "ppc64pseries", "ppc64"},
 152     {PER_LINUX, "ppc64iseries", "ppc64"},
 153 #endif
 154 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 155     {PER_LINUX32, "i386", "i386"},
 156     {PER_LINUX32, "i486", "i386"},
 157     {PER_LINUX32, "i586", "i386"},
 158     {PER_LINUX32, "i686", "i386"},
 159     {PER_LINUX32, "athlon", "i386"},
 160 #endif
 161 #if defined(__x86_64__) || defined(__i386__)
 162     {PER_LINUX, "x86_64", "x86_64"},
 163 #endif
 164 #if defined(__ia64__) || defined(__i386__)
 165     {PER_LINUX, "ia64", "ia64"},
 166 #endif
 167 #if defined(__hppa__)
 168     {PER_LINUX32, "parisc32", "parisc"},
 169     {PER_LINUX32, "parisc", "parisc"},
 170     {PER_LINUX, "parisc64", "parisc64"},
 171 #endif
 172 #if defined(__s390x__) || defined(__s390__)
 173     {PER_LINUX32, "s390", "s390"},
 174     {PER_LINUX, "s390x", "s390x"},
 175 #endif
 176 #if defined(__sparc64__) || defined(__sparc__)
 177     {PER_LINUX32, "sparc", "sparc"},
 178     {PER_LINUX32, "sparc32bash", "sparc"},
 179     {PER_LINUX32, "sparc32", "sparc"},
 180     {PER_LINUX, "sparc64", "sparc64"},
 181 #endif
 182 #if defined(__mips64__) || defined(__mips__)
 183     {PER_LINUX32, "mips32", "mips"},
 184     {PER_LINUX32, "mips", "mips"},
 185     {PER_LINUX, "mips64", "mips64"},
 186 #endif
 187 #if defined(__alpha__)
 188     {PER_LINUX, "alpha", "alpha"},
 189     {PER_LINUX, "alphaev5", "alpha"},
 190     {PER_LINUX, "alphaev56", "alpha"},
 191     {PER_LINUX, "alphaev6", "alpha"},
 192     {PER_LINUX, "alphaev67", "alpha"},
 193 #endif
 194     {-1, NULL, NULL}
 195   };
 196
 197   for(i = 0; transitions[i].perval >= 0; i++)
 198       if(!strcmp(pers, transitions[i].target_arch))
 199         break;
 200
 201   if(transitions[i].perval < 0)
 202     errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 203
 204   pers_value = transitions[i].perval | options;
 205   if (set_pers(pers_value) == -EINVAL)
 206     return 1;
 207
 208   uname(&un);
 209   if(transitions[i].result_arch &&
 210         strcmp(un.machine, transitions[i].result_arch))
 211   {
 212     if(strcmp(transitions[i].result_arch, "i386")
 213        || (strcmp(un.machine, "i486")
 214            && strcmp(un.machine, "i586")
 215            && strcmp(un.machine, "i686")
 216            && strcmp(un.machine, "athlon")))
 217       errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 218   }
 219
 220   return 0;
 221 }
 222
 223 int main(int argc, char *argv[])
 224 {
 225   const char *p;
 226   unsigned long options = 0;
 227   int verbose = 0;
 228   int c;
 229
 230   /* Options --3gb and --4gb are for compatibitity with an old Debian setarch
 231      implementation. */
 232   static const struct option longopts[] =
 233   {
 234       { "help",               0, 0, 'h' },
 235       { "version",            0, 0, 'V' },
 236       { "verbose",            0, 0, 'v' },
 237       { "addr-no-randomize",  0, 0, 'R' },
 238       { "fdpic-funcptrs",     0, 0, 'F' },
 239       { "mmap-page-zero",     0, 0, 'Z' },
 240       { "addr-compat-layout", 0, 0, 'L' },
 241       { "read-implies-exec",  0, 0, 'X' },
 242       { "32bit",              0, 0, 'B' },
 243       { "short-inode",        0, 0, 'I' },
 244       { "whole-seconds",      0, 0, 'S' },
 245       { "sticky-timeouts",    0, 0, 'T' },
 246       { "3gb",                0, 0, '3' },
 247       { "4gb",                0, 0, OPT_4GB },
 248       { "uname-2.6",          0, 0, OPT_UNAME26 },
 249       { NULL,                 0, 0, 0 }
 250   };
 251
 252   setlocale(LC_ALL, "");
 253   bindtextdomain(PACKAGE, LOCALEDIR);
 254   textdomain(PACKAGE);
 255   atexit(close_stdout);
 256
 257   if (argc < 1)
 258     show_usage(_("Not enough arguments"));
 259
 260   p = program_invocation_short_name;
 261   if (!strcmp(p, "setarch")) {
 262     argv++;
 263     argc--;
 264     if (argc < 1)
 265       show_usage(_("Not enough arguments"));
 266     p = argv[0];
 267     argv[0] = argv[-1];      /* for getopt_long() to get the program name */
 268     if (!strcmp(p, "-h") || !strcmp(p, "--help"))
 269       show_help();
 270     else if (!strcmp(p, "-V") || !strcmp(p, "--version"))
 271       show_version();
 272   }
 273   #if defined(__sparc64__) || defined(__sparc__)
 274    if (!strcmp(p, "sparc32bash")) {
 275        if (set_arch(p, 0L))
 276            err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 277        execl("/bin/bash", NULL);
 278        err(EXIT_FAILURE, "/bin/bash");
 279    }
 280   #endif
 281
 282   while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
 283     switch (c) {
 284     case 'h':
 285       show_help();
 286       break;
 287     case 'V':
 288       show_version();
 289       break;
 290     case 'v':
 291       verbose = 1;
 292       break;
 293     case 'R':
 294         turn_on(ADDR_NO_RANDOMIZE, options);
 295         break;
 296     case 'F':
 297         turn_on(FDPIC_FUNCPTRS, options);
 298         break;
 299     case 'Z':
 300         turn_on(MMAP_PAGE_ZERO, options);
 301         break;
 302     case 'L':
 303         turn_on(ADDR_COMPAT_LAYOUT, options);
 304         break;
 305     case 'X':
 306         turn_on(READ_IMPLIES_EXEC, options);
 307         break;
 308     case 'B':
 309         turn_on(ADDR_LIMIT_32BIT, options);
 310         break;
 311     case 'I':
 312         turn_on(SHORT_INODE, options);
 313         break;
 314     case 'S':
 315         turn_on(WHOLE_SECONDS, options);
 316         break;
 317     case 'T':
 318         turn_on(STICKY_TIMEOUTS, options);
 319         break;
 320     case '3':
 321         turn_on(ADDR_LIMIT_3GB, options);
 322         break;
 323     case OPT_4GB:          /* just ignore this one */
 324       break;
 325     case OPT_UNAME26:
 326         turn_on(UNAME26, options);
 327         break;
 328     }
 329   }
 330
 331   argc -= optind;
 332   argv += optind;
 333
 334   if (set_arch(p, options))
 335     err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 336
 337   if (!argc) {
 338     execl("/bin/sh", "-sh", NULL);
 339     err(EXIT_FAILURE, "/bin/sh");
 340   }
 341
 342   execvp(argv[0], argv);
 343   err(EXIT_FAILURE, "%s", argv[0]);
 344   return EXIT_FAILURE;
 345 }