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 #ifndef UNAME26
  57 # define UNAME26                 0x0020000
  58 #endif
  59 #ifndef ADDR_NO_RANDOMIZE
  60 # define ADDR_NO_RANDOMIZE       0x0040000
  61 #endif
  62 #ifndef FDPIC_FUNCPTRS
  63 # define FDPIC_FUNCPTRS          0x0080000
  64 #endif
  65 #ifndef MMAP_PAGE_ZERO
  66 # define MMAP_PAGE_ZERO          0x0100000
  67 #endif
  68 #ifndef ADDR_COMPAT_LAYOUT
  69 # define ADDR_COMPAT_LAYOUT      0x0200000
  70 #endif
  71 #ifndef READ_IMPLIES_EXEC
  72 # define READ_IMPLIES_EXEC       0x0400000
  73 #endif
  74 #ifndef ADDR_LIMIT_32BIT
  75 # define ADDR_LIMIT_32BIT        0x0800000
  76 #endif
  77 #ifndef SHORT_INODE
  78 # define SHORT_INODE             0x1000000
  79 #endif
  80 #ifndef WHOLE_SECONDS
  81 # define WHOLE_SECONDS           0x2000000
  82 #endif
  83 #ifndef STICKY_TIMEOUTS
  84 # define STICKY_TIMEOUTS         0x4000000
  85 #endif
  86 #ifndef ADDR_LIMIT_3GB
  87 # define ADDR_LIMIT_3GB          0x8000000
  88 #endif
  89
  90 static void __attribute__((__noreturn__))
  91 show_help(void)
  92 {
  93   fputs(USAGE_HEADER, stdout);
  94   printf(_(" %s%s [options] [program [program arguments]]\n"),
  95          program_invocation_short_name,
  96          !strcmp(program_invocation_short_name, "setarch") ? " <arch>" : "");
  97
  98   fputs(USAGE_OPTIONS, stdout);
  99   fputs(_(" -v, --verbose            says what options are being switched on\n"), stdout);
 100   fputs(_(" -R, --addr-no-randomize  disables randomization of the virtual address space\n"), stdout);
 101   fputs(_(" -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"), stdout);
 102   fputs(_(" -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"), stdout);
 103   fputs(_(" -L, --addr-compat-layout changes the way virtual memory is allocated\n"), stdout);
 104   fputs(_(" -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"), stdout);
 105   fputs(_(" -B, --32bit              turns on ADDR_LIMIT_32BIT\n"), stdout);
 106   fputs(_(" -I, --short-inode        turns on SHORT_INODE\n"), stdout);
 107   fputs(_(" -S, --whole-seconds      turns on WHOLE_SECONDS\n"), stdout);
 108   fputs(_(" -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"), stdout);
 109   fputs(_(" -3, --3gb                limits the used address space to a maximum of 3 GB\n"), stdout);
 110   fputs(_("     --4gb                ignored (for backward compatibility only)\n"), stdout);
 111   fputs(_("     --uname-2.6          turns on UNAME26\n"), stdout);
 112   fputs(_("     --list               list settable architectures, and exit\n"), stdout);
 113
 114   fputs(USAGE_SEPARATOR, stdout);
 115   fputs(USAGE_HELP, stdout);
 116   fputs(USAGE_VERSION, stdout);
 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   if (s)
 126     errx(EXIT_FAILURE, _("%s\nTry `%s --help' for more information."), s, program_invocation_short_name);
 127   else
 128     errx(EXIT_FAILURE, _("Try `%s --help' for more information."), program_invocation_short_name);
 129 }
 130
 131 static void __attribute__((__noreturn__))
 132 show_version(void)
 133 {
 134   printf(UTIL_LINUX_VERSION);
 135   exit(EXIT_SUCCESS);
 136 }
 137
 138 static int
 139 set_arch(const char *pers, unsigned long options, int list)
 140 {
 141   struct utsname un;
 142   int i;
 143   unsigned long pers_value;
 144
 145   struct {
 146     int perval;
 147     const char *target_arch, *result_arch;
 148   } transitions[] = {
 149     {UNAME26, "uname26", NULL},
 150     {PER_LINUX32, "linux32", NULL},
 151     {PER_LINUX, "linux64", NULL},
 152 #if defined(__powerpc__) || defined(__powerpc64__)
 153 #ifdef __BIG_ENDIAN__
 154     {PER_LINUX32, "ppc32", "ppc"},
 155     {PER_LINUX32, "ppc", "ppc"},
 156     {PER_LINUX, "ppc64", "ppc64"},
 157     {PER_LINUX, "ppc64pseries", "ppc64"},
 158     {PER_LINUX, "ppc64iseries", "ppc64"},
 159 #else
 160     {PER_LINUX32, "ppc32le", "ppcle"},
 161     {PER_LINUX32, "ppcle", "ppcle"},
 162     {PER_LINUX, "ppc64le", "ppc64le"},
 163 #endif
 164 #endif
 165 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 166     {PER_LINUX32, "i386", "i386"},
 167     {PER_LINUX32, "i486", "i386"},
 168     {PER_LINUX32, "i586", "i386"},
 169     {PER_LINUX32, "i686", "i386"},
 170     {PER_LINUX32, "athlon", "i386"},
 171 #endif
 172 #if defined(__x86_64__) || defined(__i386__)
 173     {PER_LINUX, "x86_64", "x86_64"},
 174 #endif
 175 #if defined(__ia64__) || defined(__i386__)
 176     {PER_LINUX, "ia64", "ia64"},
 177 #endif
 178 #if defined(__hppa__)
 179     {PER_LINUX32, "parisc32", "parisc"},
 180     {PER_LINUX32, "parisc", "parisc"},
 181     {PER_LINUX, "parisc64", "parisc64"},
 182 #endif
 183 #if defined(__s390x__) || defined(__s390__)
 184     {PER_LINUX32, "s390", "s390"},
 185     {PER_LINUX, "s390x", "s390x"},
 186 #endif
 187 #if defined(__sparc64__) || defined(__sparc__)
 188     {PER_LINUX32, "sparc", "sparc"},
 189     {PER_LINUX32, "sparc32bash", "sparc"},
 190     {PER_LINUX32, "sparc32", "sparc"},
 191     {PER_LINUX, "sparc64", "sparc64"},
 192 #endif
 193 #if defined(__mips64__) || defined(__mips__)
 194     {PER_LINUX32, "mips32", "mips"},
 195     {PER_LINUX32, "mips", "mips"},
 196     {PER_LINUX, "mips64", "mips64"},
 197 #endif
 198 #if defined(__alpha__)
 199     {PER_LINUX, "alpha", "alpha"},
 200     {PER_LINUX, "alphaev5", "alpha"},
 201     {PER_LINUX, "alphaev56", "alpha"},
 202     {PER_LINUX, "alphaev6", "alpha"},
 203     {PER_LINUX, "alphaev67", "alpha"},
 204 #endif
 205     {-1, NULL, NULL}
 206   };
 207
 208   if (list) {
 209     for(i = 0; transitions[i].target_arch != NULL; i++)
 210       printf("%s\n", transitions[i].target_arch);
 211     return 0;
 212   }
 213
 214   for(i = 0; transitions[i].perval >= 0; i++)
 215       if(!strcmp(pers, transitions[i].target_arch))
 216         break;
 217
 218   if(transitions[i].perval < 0)
 219     errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 220
 221   pers_value = transitions[i].perval | options;
 222   if (set_pers(pers_value) == -EINVAL)
 223     return 1;
 224
 225   uname(&un);
 226   if(transitions[i].result_arch &&
 227         strcmp(un.machine, transitions[i].result_arch))
 228   {
 229     if(strcmp(transitions[i].result_arch, "i386")
 230        || (strcmp(un.machine, "i486")
 231            && strcmp(un.machine, "i586")
 232            && strcmp(un.machine, "i686")
 233            && strcmp(un.machine, "athlon")))
 234       errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 235   }
 236
 237   return 0;
 238 }
 239
 240 int main(int argc, char *argv[])
 241 {
 242   const char *p;
 243   unsigned long options = 0;
 244   int verbose = 0;
 245   int c;
 246
 247   /* Options --3gb and --4gb are for compatibitity with an old Debian setarch
 248      implementation. */
 249   static const struct option longopts[] =
 250   {
 251       { "help",               0, 0, 'h' },
 252       { "version",            0, 0, 'V' },
 253       { "verbose",            0, 0, 'v' },
 254       { "addr-no-randomize",  0, 0, 'R' },
 255       { "fdpic-funcptrs",     0, 0, 'F' },
 256       { "mmap-page-zero",     0, 0, 'Z' },
 257       { "addr-compat-layout", 0, 0, 'L' },
 258       { "read-implies-exec",  0, 0, 'X' },
 259       { "32bit",              0, 0, 'B' },
 260       { "short-inode",        0, 0, 'I' },
 261       { "whole-seconds",      0, 0, 'S' },
 262       { "sticky-timeouts",    0, 0, 'T' },
 263       { "3gb",                0, 0, '3' },
 264       { "4gb",                0, 0, OPT_4GB },
 265       { "uname-2.6",          0, 0, OPT_UNAME26 },
 266       { NULL,                 0, 0, 0 }
 267   };
 268
 269   setlocale(LC_ALL, "");
 270   bindtextdomain(PACKAGE, LOCALEDIR);
 271   textdomain(PACKAGE);
 272   atexit(close_stdout);
 273
 274   if (argc < 1)
 275     show_usage(_("Not enough arguments"));
 276
 277   p = program_invocation_short_name;
 278   if (!strcmp(p, "setarch")) {
 279     argc--;
 280     if (argc < 1)
 281       show_usage(_("Not enough arguments"));
 282     p = argv[1];
 283     argv[1] = argv[0];          /* for getopt_long() to get the program name */
 284     argv++;
 285     if (!strcmp(p, "-h") || !strcmp(p, "--help"))
 286       show_help();
 287     else if (!strcmp(p, "-V") || !strcmp(p, "--version"))
 288       show_version();
 289     else if (!strcmp(p, "--list")) {
 290       set_arch(argv[0], 0L, 1);
 291       return EXIT_SUCCESS;
 292     }
 293   }
 294   #if defined(__sparc64__) || defined(__sparc__)
 295    if (!strcmp(p, "sparc32bash")) {
 296        if (set_arch(p, 0L, 0))
 297            err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 298        execl("/bin/bash", NULL);
 299        err(EXIT_FAILURE, _("failed to execute %s"), "/bin/bash");
 300    }
 301   #endif
 302
 303   while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
 304     switch (c) {
 305     case 'h':
 306       show_help();
 307       break;
 308     case 'V':
 309       show_version();
 310       break;
 311     case 'v':
 312       verbose = 1;
 313       break;
 314     case 'R':
 315         turn_on(ADDR_NO_RANDOMIZE, options);
 316         break;
 317     case 'F':
 318         turn_on(FDPIC_FUNCPTRS, options);
 319         break;
 320     case 'Z':
 321         turn_on(MMAP_PAGE_ZERO, options);
 322         break;
 323     case 'L':
 324         turn_on(ADDR_COMPAT_LAYOUT, options);
 325         break;
 326     case 'X':
 327         turn_on(READ_IMPLIES_EXEC, options);
 328         break;
 329     case 'B':
 330         turn_on(ADDR_LIMIT_32BIT, options);
 331         break;
 332     case 'I':
 333         turn_on(SHORT_INODE, options);
 334         break;
 335     case 'S':
 336         turn_on(WHOLE_SECONDS, options);
 337         break;
 338     case 'T':
 339         turn_on(STICKY_TIMEOUTS, options);
 340         break;
 341     case '3':
 342         turn_on(ADDR_LIMIT_3GB, options);
 343         break;
 344     case OPT_4GB:          /* just ignore this one */
 345       break;
 346     case OPT_UNAME26:
 347         turn_on(UNAME26, options);
 348         break;
 349     default:
 350         show_usage(NULL);
 351     }
 352   }
 353
 354   argc -= optind;
 355   argv += optind;
 356
 357   if (set_arch(p, options, 0))
 358     err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 359
 360   /* flush all output streams before exec */
 361   fflush(NULL);
 362
 363   if (!argc) {
 364     execl("/bin/sh", "-sh", NULL);
 365     err(EXIT_FAILURE, _("failed to execute %s"), "/bin/sh");
 366   }
 367
 368   execvp(argv[0], argv);
 369   err(EXIT_FAILURE, "%s", argv[0]);
 370   return EXIT_FAILURE;
 371 }