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
  39 #define set_pers(pers) ((long)syscall(SYS_personality, pers))
  40
  41 /* Options without equivalent short options */
  42 enum {
  43         OPT_4GB         = CHAR_MAX + 1,
  44         OPT_UNAME26
  45 };
  46
  47 #define turn_on(_flag, _opts) \
  48         do { \
  49                 (_opts) |= _flag; \
  50                 if (verbose) \
  51                         printf(_("Switching on %s.\n"), #_flag); \
  52         } while(0)
  53
  54
  55 #if !HAVE_DECL_UNAME26
  56 # define UNAME26                 0x0020000
  57 #endif
  58 #if !HAVE_DECL_ADDR_NO_RANDOMIZE
  59 # define ADDR_NO_RANDOMIZE       0x0040000
  60 #endif
  61 #if !HAVE_DECL_FDPIC_FUNCPTRS
  62 # define FDPIC_FUNCPTRS          0x0080000
  63 #endif
  64 #if !HAVE_DECL_MMAP_PAGE_ZERO
  65 # define MMAP_PAGE_ZERO          0x0100000
  66 #endif
  67 #if !HAVE_DECL_ADDR_COMPAT_LAYOUT
  68 # define ADDR_COMPAT_LAYOUT      0x0200000
  69 #endif
  70 #if !HAVE_DECL_READ_IMPLIES_EXEC
  71 # define READ_IMPLIES_EXEC       0x0400000
  72 #endif
  73 #if !HAVE_DECL_ADDR_LIMIT_32BIT
  74 # define ADDR_LIMIT_32BIT        0x0800000
  75 #endif
  76 #if !HAVE_DECL_SHORT_INODE
  77 # define SHORT_INODE             0x1000000
  78 #endif
  79 #if !HAVE_DECL_WHOLE_SECONDS
  80 # define WHOLE_SECONDS           0x2000000
  81 #endif
  82 #if !HAVE_DECL_STICKY_TIMEOUTS
  83 # define STICKY_TIMEOUTS         0x4000000
  84 #endif
  85 #if !HAVE_DECL_ADDR_LIMIT_3GB
  86 # define ADDR_LIMIT_3GB          0x8000000
  87 #endif
  88
  89 static void __attribute__((__noreturn__))
  90 show_help(void)
  91 {
  92   printf(_("Usage: %s%s [options] [program [program arguments]]\n\nOptions:\n"),
  93          program_invocation_short_name, !strcmp(program_invocation_short_name, "setarch") ? " <arch>" : "");
  94
  95    printf(_(
  96    " -v, --verbose            says what options are being switched on\n"
  97    " -R, --addr-no-randomize  disables randomization of the virtual address space\n"
  98    " -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"
  99    " -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"
 100    " -L, --addr-compat-layout changes the way virtual memory is allocated\n"
 101    " -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"
 102    " -B, --32bit              turns on ADDR_LIMIT_32BIT\n"
 103    " -I, --short-inode        turns on SHORT_INODE\n"
 104    " -S, --whole-seconds      turns on WHOLE_SECONDS\n"
 105    " -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"
 106    " -3, --3gb                limits the used address space to a maximum of 3 GB\n"
 107    "     --4gb                ignored (for backward compatibility only)\n"));
 108
 109    printf(_(
 110    "     --uname-2.6          turns on UNAME26\n"));
 111   printf(USAGE_HELP);
 112   printf(USAGE_VERSION);
 113
 114   printf(_("\nFor more information see setarch(8).\n"));
 115   exit(EXIT_SUCCESS);
 116 }
 117
 118 static void __attribute__((__noreturn__))
 119 show_usage(const char *s)
 120 {
 121   errx(EXIT_FAILURE, _("%s\nTry `%s --help' for more information."), s, program_invocation_short_name);
 122 }
 123
 124 static void __attribute__((__noreturn__))
 125 show_version(void)
 126 {
 127   printf(UTIL_LINUX_VERSION);
 128   exit(EXIT_SUCCESS);
 129 }
 130
 131 int set_arch(const char *pers, unsigned long options)
 132 {
 133   struct utsname un;
 134   int i;
 135   unsigned long pers_value;
 136
 137   struct {
 138     int perval;
 139     const char *target_arch, *result_arch;
 140   } transitions[] = {
 141     {PER_LINUX32, "linux32", NULL},
 142     {PER_LINUX, "linux64", NULL},
 143 #if defined(__powerpc__) || defined(__powerpc64__)
 144     {PER_LINUX32, "ppc32", "ppc"},
 145     {PER_LINUX32, "ppc", "ppc"},
 146     {PER_LINUX, "ppc64", "ppc64"},
 147     {PER_LINUX, "ppc64pseries", "ppc64"},
 148     {PER_LINUX, "ppc64iseries", "ppc64"},
 149 #endif
 150 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 151     {PER_LINUX32, "i386", "i386"},
 152     {PER_LINUX32, "i486", "i386"},
 153     {PER_LINUX32, "i586", "i386"},
 154     {PER_LINUX32, "i686", "i386"},
 155     {PER_LINUX32, "athlon", "i386"},
 156 #endif
 157 #if defined(__x86_64__) || defined(__i386__)
 158     {PER_LINUX, "x86_64", "x86_64"},
 159 #endif
 160 #if defined(__ia64__) || defined(__i386__)
 161     {PER_LINUX, "ia64", "ia64"},
 162 #endif
 163 #if defined(__hppa__)
 164     {PER_LINUX32, "parisc32", "parisc"},
 165     {PER_LINUX32, "parisc", "parisc"},
 166     {PER_LINUX, "parisc64", "parisc64"},
 167 #endif
 168 #if defined(__s390x__) || defined(__s390__)
 169     {PER_LINUX32, "s390", "s390"},
 170     {PER_LINUX, "s390x", "s390x"},
 171 #endif
 172 #if defined(__sparc64__) || defined(__sparc__)
 173     {PER_LINUX32, "sparc", "sparc"},
 174     {PER_LINUX32, "sparc32bash", "sparc"},
 175     {PER_LINUX32, "sparc32", "sparc"},
 176     {PER_LINUX, "sparc64", "sparc64"},
 177 #endif
 178 #if defined(__mips64__) || defined(__mips__)
 179     {PER_LINUX32, "mips32", "mips"},
 180     {PER_LINUX32, "mips", "mips"},
 181     {PER_LINUX, "mips64", "mips64"},
 182 #endif
 183 #if defined(__alpha__)
 184     {PER_LINUX, "alpha", "alpha"},
 185     {PER_LINUX, "alphaev5", "alpha"},
 186     {PER_LINUX, "alphaev56", "alpha"},
 187     {PER_LINUX, "alphaev6", "alpha"},
 188     {PER_LINUX, "alphaev67", "alpha"},
 189 #endif
 190     {-1, NULL, NULL}
 191   };
 192
 193   for(i = 0; transitions[i].perval >= 0; i++)
 194       if(!strcmp(pers, transitions[i].target_arch))
 195         break;
 196
 197   if(transitions[i].perval < 0)
 198     errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 199
 200   pers_value = transitions[i].perval | options;
 201   if (set_pers(pers_value) == -EINVAL)
 202     return 1;
 203
 204   uname(&un);
 205   if(transitions[i].result_arch &&
 206         strcmp(un.machine, transitions[i].result_arch))
 207   {
 208     if(strcmp(transitions[i].result_arch, "i386")
 209        || (strcmp(un.machine, "i486")
 210            && strcmp(un.machine, "i586")
 211            && strcmp(un.machine, "i686")
 212            && strcmp(un.machine, "athlon")))
 213       errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 214   }
 215
 216   return 0;
 217 }
 218
 219 int main(int argc, char *argv[])
 220 {
 221   const char *p;
 222   unsigned long options = 0;
 223   int verbose = 0;
 224   int c;
 225
 226   /* Options --3gb and --4gb are for compatibitity with an old Debian setarch
 227      implementation. */
 228   static const struct option longopts[] =
 229   {
 230       { "help",               0, 0, 'h' },
 231       { "version",            0, 0, 'V' },
 232       { "verbose",            0, 0, 'v' },
 233       { "addr-no-randomize",  0, 0, 'R' },
 234       { "fdpic-funcptrs",     0, 0, 'F' },
 235       { "mmap-page-zero",     0, 0, 'Z' },
 236       { "addr-compat-layout", 0, 0, 'L' },
 237       { "read-implies-exec",  0, 0, 'X' },
 238       { "32bit",              0, 0, 'B' },
 239       { "short-inode",        0, 0, 'I' },
 240       { "whole-seconds",      0, 0, 'S' },
 241       { "sticky-timeouts",    0, 0, 'T' },
 242       { "3gb",                0, 0, '3' },
 243       { "4gb",                0, 0, OPT_4GB },
 244       { "uname-2.6",          0, 0, OPT_UNAME26 },
 245       { NULL,                 0, 0, 0 }
 246   };
 247
 248   setlocale(LC_ALL, "");
 249   bindtextdomain(PACKAGE, LOCALEDIR);
 250   textdomain(PACKAGE);
 251
 252   if (argc < 1)
 253     show_usage(_("Not enough arguments"));
 254
 255   p = program_invocation_short_name;
 256   if (!strcmp(p, "setarch")) {
 257     argv++;
 258     argc--;
 259     if (argc < 1)
 260       show_usage(_("Not enough arguments"));
 261     p = argv[0];
 262     argv[0] = argv[-1];      /* for getopt_long() to get the program name */
 263     if (!strcmp(p, "-h") || !strcmp(p, "--help"))
 264       show_help();
 265     else if (!strcmp(p, "-V") || !strcmp(p, "--version"))
 266       show_version();
 267   }
 268   #if defined(__sparc64__) || defined(__sparc__)
 269    if (!strcmp(p, "sparc32bash")) {
 270        if (set_arch(p, 0L))
 271            err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 272        execl("/bin/bash", NULL);
 273        err(EXIT_FAILURE, "/bin/bash");
 274    }
 275   #endif
 276
 277   while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
 278     switch (c) {
 279     case 'h':
 280       show_help();
 281       break;
 282     case 'V':
 283       show_version();
 284       break;
 285     case 'v':
 286       verbose = 1;
 287       break;
 288     case 'R':
 289         turn_on(ADDR_NO_RANDOMIZE, options);
 290         break;
 291     case 'F':
 292         turn_on(FDPIC_FUNCPTRS, options);
 293         break;
 294     case 'Z':
 295         turn_on(MMAP_PAGE_ZERO, options);
 296         break;
 297     case 'L':
 298         turn_on(ADDR_COMPAT_LAYOUT, options);
 299         break;
 300     case 'X':
 301         turn_on(READ_IMPLIES_EXEC, options);
 302         break;
 303     case 'B':
 304         turn_on(ADDR_LIMIT_32BIT, options);
 305         break;
 306     case 'I':
 307         turn_on(SHORT_INODE, options);
 308         break;
 309     case 'S':
 310         turn_on(WHOLE_SECONDS, options);
 311         break;
 312     case 'T':
 313         turn_on(STICKY_TIMEOUTS, options);
 314         break;
 315     case '3':
 316         turn_on(ADDR_LIMIT_3GB, options);
 317         break;
 318     case OPT_4GB:          /* just ignore this one */
 319       break;
 320     case OPT_UNAME26:
 321         turn_on(UNAME26, options);
 322         break;
 323     }
 324   }
 325
 326   argc -= optind;
 327   argv += optind;
 328
 329   if (set_arch(p, options))
 330     err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 331
 332   if (!argc) {
 333     execl("/bin/sh", "-sh", NULL);
 334     err(EXIT_FAILURE, "/bin/sh");
 335   }
 336
 337   execvp(argv[0], argv);
 338   err(EXIT_FAILURE, "%s", argv[0]);
 339   return EXIT_FAILURE;
 340 }