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 <errno.h>
  34 #include <error.h>
  35 #include <getopt.h>
  36 #include <limits.h>
  37 #include <sys/utsname.h>
  38 #include "nls.h"
  39
  40 #define set_pers(pers) ((long)syscall(SYS_personality, pers))
  41
  42 /* Option --4gb has no equivalent short option, use a non-character as a
  43    pseudo short option. */
  44 #define OPT_4GB (CHAR_MAX+1)
  45
  46 #define turn_on(_flag, _opts) \
  47         do { \
  48                 (_opts) |= _flag; \
  49                 if (verbose) \
  50                         printf(_("Switching on %s.\n"), #_flag); \
  51         } while(0)
  52
  53
  54 #if !HAVE_DECL_ADDR_NO_RANDOMIZE
  55 # define ADDR_NO_RANDOMIZE       0x0040000
  56 #endif
  57 #if !HAVE_DECL_FDPIC_FUNCPTRS
  58 # define FDPIC_FUNCPTRS          0x0080000
  59 #endif
  60 #if !HAVE_DECL_MMAP_PAGE_ZERO
  61 # define MMAP_PAGE_ZERO          0x0100000
  62 #endif
  63 #if !HAVE_DECL_ADDR_COMPAT_LAYOUT
  64 # define ADDR_COMPAT_LAYOUT      0x0200000
  65 #endif
  66 #if !HAVE_DECL_READ_IMPLIES_EXEC
  67 # define READ_IMPLIES_EXEC       0x0400000
  68 #endif
  69 #if !HAVE_DECL_ADDR_LIMIT_32BIT
  70 # define ADDR_LIMIT_32BIT        0x0800000
  71 #endif
  72 #if !HAVE_DECL_SHORT_INODE
  73 # define SHORT_INODE             0x1000000
  74 #endif
  75 #if !HAVE_DECL_WHOLE_SECONDS
  76 # define WHOLE_SECONDS           0x2000000
  77 #endif
  78 #if !HAVE_DECL_STICKY_TIMEOUTS
  79 # define STICKY_TIMEOUTS         0x4000000
  80 #endif
  81 #if !HAVE_DECL_ADDR_LIMIT_3GB
  82 # define ADDR_LIMIT_3GB          0x8000000
  83 #endif
  84
  85 /* Options --3gb and --4gb are for compatibitity with an old Debian setarch
  86    implementation. */
  87 struct option longopts[] =
  88 {
  89     { "help",               0, 0, 'h' },
  90     { "verbose",            0, 0, 'v' },
  91     { "addr-no-randomize",  0, 0, 'R' },
  92     { "fdpic-funcptrs",     0, 0, 'F' },
  93     { "mmap-page-zero",     0, 0, 'Z' },
  94     { "addr-compat-layout", 0, 0, 'L' },
  95     { "read-implies-exec",  0, 0, 'X' },
  96     { "32bit",              0, 0, 'B' },
  97     { "short-inode",        0, 0, 'I' },
  98     { "whole-seconds",      0, 0, 'S' },
  99     { "sticky-timeouts",    0, 0, 'T' },
 100     { "3gb",                0, 0, '3' },
 101     { "4gb",                0, 0, OPT_4GB },
 102     { NULL,                 0, 0, 0 }
 103 };
 104
 105 static void __attribute__((__noreturn__))
 106 show_help(void)
 107 {
 108   const char *p = program_invocation_short_name;
 109
 110   if (!*p)
 111     p = "setarch";
 112
 113   printf(_("Usage: %s%s [options] [program [program arguments]]\n\nOptions:\n"),
 114          p, !strcmp(p, "setarch") ? " <arch>" : "");
 115
 116    printf(_(
 117    " -h, --help               displays this help text\n"
 118    " -v, --verbose            says what options are being switched on\n"
 119    " -R, --addr-no-randomize  disables randomization of the virtual address space\n"
 120    " -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"
 121    " -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"
 122    " -L, --addr-compat-layout changes the way virtual memory is allocated\n"
 123    " -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"
 124    " -B, --32bit              turns on ADDR_LIMIT_32BIT\n"
 125    " -I, --short-inode        turns on SHORT_INODE\n"
 126    " -S, --whole-seconds      turns on WHOLE_SECONDS\n"
 127    " -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"
 128    " -3, --3gb                limits the used address space to a maximum of 3 GB\n"
 129    "     --4gb                ignored (for backward compatibility only)\n"));
 130
 131   printf(_("\nFor more information see setarch(8).\n"));
 132   exit(EXIT_SUCCESS);
 133 }
 134
 135 static void __attribute__((__noreturn__))
 136 show_usage(const char *s)
 137 {
 138   const char *p = program_invocation_short_name;
 139
 140   if (!*p)
 141     p = "setarch";
 142
 143   fprintf(stderr, _("%s: %s\nTry `%s --help' for more information.\n"), p, s, p);
 144   exit(EXIT_FAILURE);
 145 }
 146
 147
 148 int set_arch(const char *pers, unsigned long options)
 149 {
 150   struct utsname un;
 151   int i;
 152   unsigned long pers_value, res;
 153
 154   struct {
 155     int perval;
 156     const char *target_arch, *result_arch;
 157   } transitions[] = {
 158     {PER_LINUX32, "linux32", NULL},
 159     {PER_LINUX, "linux64", NULL},
 160 #if defined(__powerpc__) || defined(__powerpc64__)
 161     {PER_LINUX32, "ppc32", "ppc"},
 162     {PER_LINUX32, "ppc", "ppc"},
 163     {PER_LINUX, "ppc64", "ppc64"},
 164     {PER_LINUX, "ppc64pseries", "ppc64"},
 165     {PER_LINUX, "ppc64iseries", "ppc64"},
 166 #endif
 167 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 168     {PER_LINUX32, "i386", "i386"},
 169     {PER_LINUX32, "i486", "i386"},
 170     {PER_LINUX32, "i586", "i386"},
 171     {PER_LINUX32, "i686", "i386"},
 172     {PER_LINUX32, "athlon", "i386"},
 173 #endif
 174 #if defined(__x86_64__) || defined(__i386__)
 175     {PER_LINUX, "x86_64", "x86_64"},
 176 #endif
 177 #if defined(__ia64__) || defined(__i386__)
 178     {PER_LINUX, "ia64", "ia64"},
 179 #endif
 180 #if defined(__hppa__)
 181     {PER_LINUX32, "parisc32", "parisc"},
 182     {PER_LINUX32, "parisc", "parisc"},
 183     {PER_LINUX, "parisc64", "parisc64"},
 184 #endif
 185 #if defined(__s390x__) || defined(__s390__)
 186     {PER_LINUX32, "s390", "s390"},
 187     {PER_LINUX, "s390x", "s390x"},
 188 #endif
 189 #if defined(__sparc64__) || defined(__sparc__)
 190     {PER_LINUX32, "sparc", "sparc"},
 191     {PER_LINUX32, "sparc32bash", "sparc"},
 192     {PER_LINUX32, "sparc32", "sparc"},
 193     {PER_LINUX, "sparc64", "sparc64"},
 194 #endif
 195 #if defined(__mips64__) || defined(__mips__)
 196     {PER_LINUX32, "mips32", "mips"},
 197     {PER_LINUX32, "mips", "mips"},
 198     {PER_LINUX, "mips64", "mips64"},
 199 #endif
 200 #if defined(__alpha__)
 201     {PER_LINUX, "alpha", "alpha"},
 202     {PER_LINUX, "alphaev5", "alpha"},
 203     {PER_LINUX, "alphaev56", "alpha"},
 204     {PER_LINUX, "alphaev6", "alpha"},
 205     {PER_LINUX, "alphaev67", "alpha"},
 206 #endif
 207     {-1, NULL, NULL}
 208   };
 209
 210   for(i = 0; transitions[i].perval >= 0; i++)
 211       if(!strcmp(pers, transitions[i].target_arch))
 212         break;
 213
 214   if(transitions[i].perval < 0)
 215     error(EXIT_FAILURE, 0, _("%s: Unrecognized architecture"), pers);
 216
 217   pers_value = transitions[i].perval | options;
 218   res = set_pers(pers_value);
 219   if(res == -EINVAL)
 220     return 1;
 221
 222   uname(&un);
 223   if(transitions[i].result_arch &&
 224         strcmp(un.machine, transitions[i].result_arch))
 225   {
 226     if(strcmp(transitions[i].result_arch, "i386")
 227        || (strcmp(un.machine, "i486")
 228            && strcmp(un.machine, "i586")
 229            && strcmp(un.machine, "i686")
 230            && strcmp(un.machine, "athlon")))
 231       error(EXIT_FAILURE, 0, _("%s: Unrecognized architecture"), pers);
 232   }
 233
 234   return 0;
 235 }
 236
 237 int main(int argc, char *argv[])
 238 {
 239   const char *p;
 240   unsigned long options = 0;
 241   int verbose = 0;
 242   int c;
 243
 244   setlocale(LC_ALL, "");
 245   bindtextdomain(PACKAGE, LOCALEDIR);
 246   textdomain(PACKAGE);
 247
 248   if (argc < 1)
 249     show_usage(_("Not enough arguments"));
 250
 251   p = program_invocation_short_name;
 252   if (!strcmp(p, "setarch")) {
 253     argv++;
 254     argc--;
 255     if (argc < 1)
 256       show_usage(_("Not enough arguments"));
 257     p = argv[0];
 258     argv[0] = argv[-1];      /* for getopt_long() to get the program name */
 259     if (!strcmp(p, "-h") || !strcmp(p, "--help"))
 260       show_help();
 261   }
 262   #if defined(__sparc64__) || defined(__sparc__)
 263    if (!strcmp(p, "sparc32bash")) {
 264        if (set_arch(p, 0L))
 265            error(EXIT_FAILURE, errno, _("Failed to set personality to %s"), p);
 266        execl("/bin/bash", NULL);
 267        error(EXIT_FAILURE, errno, "/bin/bash");
 268    }
 269   #endif
 270
 271   while ((c = getopt_long(argc, argv, "+hv3BFILRSTXZ", longopts, NULL)) != -1) {
 272     switch (c) {
 273     case 'h':
 274       show_help();
 275       break;
 276     case 'v':
 277       verbose = 1;
 278       break;
 279     case 'R':
 280         turn_on(ADDR_NO_RANDOMIZE, options);
 281         break;
 282     case 'F':
 283         turn_on(FDPIC_FUNCPTRS, options);
 284         break;
 285     case 'Z':
 286         turn_on(MMAP_PAGE_ZERO, options);
 287         break;
 288     case 'L':
 289         turn_on(ADDR_COMPAT_LAYOUT, options);
 290         break;
 291     case 'X':
 292         turn_on(READ_IMPLIES_EXEC, options);
 293         break;
 294     case 'B':
 295         turn_on(ADDR_LIMIT_32BIT, options);
 296         break;
 297     case 'I':
 298         turn_on(SHORT_INODE, options);
 299         break;
 300     case 'S':
 301         turn_on(WHOLE_SECONDS, options);
 302         break;
 303     case 'T':
 304         turn_on(STICKY_TIMEOUTS, options);
 305         break;
 306     case '3':
 307         turn_on(ADDR_LIMIT_3GB, options);
 308         break;
 309     case OPT_4GB:          /* just ignore this one */
 310       break;
 311     }
 312   }
 313
 314   argc -= optind;
 315   argv += optind;
 316
 317   if (set_arch(p, options))
 318     error(EXIT_FAILURE, errno, _("Failed to set personality to %s"), p);
 319
 320   if (!argc) {
 321     execl("/bin/sh", "-sh", NULL);
 322     error(EXIT_FAILURE, errno, "/bin/sh");
 323   }
 324
 325   execvp(argv[0], argv);
 326   error(EXIT_FAILURE, errno, "%s", argv[0]);
 327   return EXIT_FAILURE;
 328 }