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 <sys/personality.h>
  28 #include <unistd.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <getopt.h>
  33 #include <limits.h>
  34 #include <sys/utsname.h>
  35 #include "nls.h"
  36 #include "c.h"
  37 #include "closestream.h"
  38
  39 #ifndef HAVE_PERSONALITY
  40 # include <syscall.h>
  41 # define personality(pers) ((long)syscall(SYS_personality, pers))
  42 #endif
  43
  44 /* Options without equivalent short options */
  45 enum {
  46         OPT_4GB = CHAR_MAX + 1,
  47         OPT_UNAME26
  48 };
  49
  50 #define turn_on(_flag, _opts) \
  51         do { \
  52                 (_opts) |= _flag; \
  53                 if (verbose) \
  54                         printf(_("Switching on %s.\n"), #_flag); \
  55         } while(0)
  56
  57 #ifndef UNAME26
  58 # define UNAME26                 0x0020000
  59 #endif
  60 #ifndef ADDR_NO_RANDOMIZE
  61 # define ADDR_NO_RANDOMIZE       0x0040000
  62 #endif
  63 #ifndef FDPIC_FUNCPTRS
  64 # define FDPIC_FUNCPTRS          0x0080000
  65 #endif
  66 #ifndef MMAP_PAGE_ZERO
  67 # define MMAP_PAGE_ZERO          0x0100000
  68 #endif
  69 #ifndef ADDR_COMPAT_LAYOUT
  70 # define ADDR_COMPAT_LAYOUT      0x0200000
  71 #endif
  72 #ifndef READ_IMPLIES_EXEC
  73 # define READ_IMPLIES_EXEC       0x0400000
  74 #endif
  75 #ifndef ADDR_LIMIT_32BIT
  76 # define ADDR_LIMIT_32BIT        0x0800000
  77 #endif
  78 #ifndef SHORT_INODE
  79 # define SHORT_INODE             0x1000000
  80 #endif
  81 #ifndef WHOLE_SECONDS
  82 # define WHOLE_SECONDS           0x2000000
  83 #endif
  84 #ifndef STICKY_TIMEOUTS
  85 # define STICKY_TIMEOUTS         0x4000000
  86 #endif
  87 #ifndef ADDR_LIMIT_3GB
  88 # define ADDR_LIMIT_3GB          0x8000000
  89 #endif
  90
  91 static void __attribute__((__noreturn__)) show_help(void)
  92 {
  93         fputs(USAGE_HEADER, stdout);
  94         if (!strcmp(program_invocation_short_name, "setarch"))
  95                 printf(_(" %s <arch> [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
  96         else
  97                 printf(_(" %s [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
  98
  99         fputs(USAGE_SEPARATOR, stdout);
 100         fputs(_("Change the reported architecture and set personality flags.\n"), stdout);
 101
 102         fputs(USAGE_OPTIONS, stdout);
 103         fputs(_(" -B, --32bit              turns on ADDR_LIMIT_32BIT\n"), stdout);
 104         fputs(_(" -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"), stdout);
 105         fputs(_(" -I, --short-inode        turns on SHORT_INODE\n"), stdout);
 106         fputs(_(" -L, --addr-compat-layout changes the way virtual memory is allocated\n"), stdout);
 107         fputs(_(" -R, --addr-no-randomize  disables randomization of the virtual address space\n"), stdout);
 108         fputs(_(" -S, --whole-seconds      turns on WHOLE_SECONDS\n"), stdout);
 109         fputs(_(" -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"), stdout);
 110         fputs(_(" -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"), stdout);
 111         fputs(_(" -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"), stdout);
 112         fputs(_(" -3, --3gb                limits the used address space to a maximum of 3 GB\n"), stdout);
 113         fputs(_("     --4gb                ignored (for backward compatibility only)\n"), stdout);
 114         fputs(_("     --uname-2.6          turns on UNAME26\n"), stdout);
 115         fputs(_(" -v, --verbose            say what options are being switched on\n"), stdout);
 116         fputs(_("     --list               list settable architectures, and exit\n"), stdout);
 117
 118         fputs(USAGE_SEPARATOR, stdout);
 119         fputs(USAGE_HELP, stdout);
 120         fputs(USAGE_VERSION, stdout);
 121         printf(USAGE_MAN_TAIL("setarch(8)"));
 122
 123         exit(EXIT_SUCCESS);
 124 }
 125
 126 static void __attribute__((__noreturn__)) show_usage(const char *s)
 127 {
 128         if (s)
 129                 errx(EXIT_FAILURE,
 130                      _("%s\nTry `%s --help' for more information."), s,
 131                      program_invocation_short_name);
 132         else
 133                 errx(EXIT_FAILURE, _("Try `%s --help' for more information."),
 134                      program_invocation_short_name);
 135 }
 136
 137 static void __attribute__((__noreturn__))
 138     show_version(void)
 139 {
 140         printf(UTIL_LINUX_VERSION);
 141         exit(EXIT_SUCCESS);
 142 }
 143
 144 static int set_arch(const char *pers, unsigned long options, int list)
 145 {
 146         struct utsname un;
 147         int i;
 148         unsigned long pers_value;
 149
 150         struct {
 151                 int perval;
 152                 const char *target_arch, *result_arch;
 153         } transitions[] = {
 154                 {UNAME26,       "uname26",      NULL},
 155                 {PER_LINUX32,   "linux32",      NULL},
 156                 {PER_LINUX,     "linux64",      NULL},
 157 #if defined(__powerpc__) || defined(__powerpc64__)
 158 # ifdef __BIG_ENDIAN__
 159                 {PER_LINUX32,   "ppc32",        "ppc"},
 160                 {PER_LINUX32,   "ppc",          "ppc"},
 161                 {PER_LINUX,     "ppc64",        "ppc64"},
 162                 {PER_LINUX,     "ppc64pseries", "ppc64"},
 163                 {PER_LINUX,     "ppc64iseries", "ppc64"},
 164 # else
 165                 PER_LINUX32,    "ppc32le",      "ppcle"},
 166                 PER_LINUX32,    "ppcle",        "ppcle"},
 167                 PER_LINUX,      "ppc64le",      "ppc64le"},
 168 # endif
 169 #endif
 170 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 171                 {PER_LINUX32,   "i386",         "i386"},
 172                 {PER_LINUX32,   "i486",         "i386"},
 173                 {PER_LINUX32,   "i586",         "i386"},
 174                 {PER_LINUX32,   "i686",         "i386"},
 175                 {PER_LINUX32,   "athlon",       "i386"},
 176 #endif
 177 #if defined(__x86_64__) || defined(__i386__)
 178                 {PER_LINUX,     "x86_64",       "x86_64"},
 179 #endif
 180 #if defined(__ia64__) || defined(__i386__)
 181                 {PER_LINUX,     "ia64",         "ia64"},
 182 #endif
 183 #if defined(__hppa__)
 184                 {PER_LINUX32,   "parisc32",     "parisc"},
 185                 {PER_LINUX32,   "parisc",       "parisc"},
 186                 {PER_LINUX,     "parisc64",     "parisc64"},
 187 #endif
 188 #if defined(__s390x__) || defined(__s390__)
 189                 {PER_LINUX32,   "s390",         "s390"},
 190                 {PER_LINUX,     "s390x",        "s390x"},
 191 #endif
 192 #if defined(__sparc64__) || defined(__sparc__)
 193                 {PER_LINUX32,   "sparc",        "sparc"},
 194                 {PER_LINUX32,   "sparc32bash",  "sparc"},
 195                 {PER_LINUX32,   "sparc32",      "sparc"},
 196                 {PER_LINUX,     "sparc64",      "sparc64"},
 197 #endif
 198 #if defined(__mips64__) || defined(__mips__)
 199                 {PER_LINUX32,   "mips32",       "mips"},
 200                 {PER_LINUX32,   "mips",         "mips"},
 201                 {PER_LINUX,     "mips64",       "mips64"},
 202 #endif
 203 #if defined(__alpha__)
 204                 {PER_LINUX,     "alpha",        "alpha"},
 205                 {PER_LINUX,     "alphaev5",     "alpha"},
 206                 {PER_LINUX,     "alphaev56",    "alpha"},
 207                 {PER_LINUX,     "alphaev6",     "alpha"},
 208                 {PER_LINUX,     "alphaev67",    "alpha"},
 209 #endif
 210                 /* place holder, will be filled up at runtime */
 211                 {-1,            NULL,           NULL},
 212                 {-1,            NULL,           NULL}
 213         };
 214
 215         /* Add the trivial transition {PER_LINUX, machine, machine} if no
 216          * such target_arch is hardcoded yet.  */
 217         uname(&un);
 218         for (i = 0; transitions[i].perval >= 0; i++)
 219                 if (!strcmp(un.machine, transitions[i].target_arch))
 220                         break;
 221         if (transitions[i].perval < 0) {
 222                 unsigned long wrdsz = CHAR_BIT * sizeof(void *);
 223                 if (wrdsz == 32 || wrdsz == 64) {
 224                         /* fill up the place holder */
 225                         transitions[i].perval = wrdsz == 32 ? PER_LINUX32 : PER_LINUX;
 226                         transitions[i].target_arch = un.machine;
 227                         transitions[i].result_arch = un.machine;
 228                 }
 229         }
 230         if (list) {
 231                 for (i = 0; transitions[i].target_arch != NULL; i++)
 232                         printf("%s\n", transitions[i].target_arch);
 233                 return 0;
 234         }
 235         for (i = 0; transitions[i].perval >= 0; i++)
 236                 if (!strcmp(pers, transitions[i].target_arch))
 237                         break;
 238         if (transitions[i].perval < 0)
 239                 errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), pers);
 240         pers_value = transitions[i].perval | options;
 241         if (personality(pers_value) == -EINVAL)
 242                 return 1;
 243         uname(&un);
 244         if (transitions[i].result_arch && strcmp(un.machine, transitions[i].result_arch)) {
 245                 if (strcmp(transitions[i].result_arch, "i386")
 246                     || (strcmp(un.machine, "i486")
 247                         && strcmp(un.machine, "i586")
 248                         && strcmp(un.machine, "i686")
 249                         && strcmp(un.machine, "athlon")))
 250                         errx(EXIT_FAILURE, _("Kernel cannot set architecture to %s"), pers);
 251         }
 252         return 0;
 253 }
 254
 255 int main(int argc, char *argv[])
 256 {
 257         const char *p;
 258         unsigned long options = 0;
 259         int verbose = 0;
 260         int c;
 261
 262         /* Options --3gb and --4gb are for compatibitity with an old
 263          * Debian setarch implementation.  */
 264         static const struct option longopts[] = {
 265                 {"help",                no_argument,    NULL,   'h'},
 266                 {"version",             no_argument,    NULL,   'V'},
 267                 {"verbose",             no_argument,    NULL,   'v'},
 268                 {"addr-no-randomize",   no_argument,    NULL,   'R'},
 269                 {"fdpic-funcptrs",      no_argument,    NULL,   'F'},
 270                 {"mmap-page-zero",      no_argument,    NULL,   'Z'},
 271                 {"addr-compat-layout",  no_argument,    NULL,   'L'},
 272                 {"read-implies-exec",   no_argument,    NULL,   'X'},
 273                 {"32bit",               no_argument,    NULL,   'B'},
 274                 {"short-inode",         no_argument,    NULL,   'I'},
 275                 {"whole-seconds",       no_argument,    NULL,   'S'},
 276                 {"sticky-timeouts",     no_argument,    NULL,   'T'},
 277                 {"3gb",                 no_argument,    NULL,   '3'},
 278                 {"4gb",                 no_argument,    NULL,   OPT_4GB},
 279                 {"uname-2.6",           no_argument,    NULL,   OPT_UNAME26},
 280                 {NULL,                  0,              NULL,   0}
 281         };
 282
 283         setlocale(LC_ALL, "");
 284         bindtextdomain(PACKAGE, LOCALEDIR);
 285         textdomain(PACKAGE);
 286         atexit(close_stdout);
 287
 288         if (argc < 1)
 289                 show_usage(_("Not enough arguments"));
 290
 291         p = program_invocation_short_name;
 292         if (!strcmp(p, "setarch")) {
 293                 argc--;
 294                 if (argc < 1)
 295                         show_usage(_("Not enough arguments"));
 296                 p = argv[1];
 297                 argv[1] = argv[0];      /* for getopt_long() to get the program name */
 298                 argv++;
 299                 if (!strcmp(p, "-h") || !strcmp(p, "--help"))
 300                         show_help();
 301                 else if (!strcmp(p, "-V") || !strcmp(p, "--version"))
 302                         show_version();
 303                 else if (!strcmp(p, "--list")) {
 304                         set_arch(argv[0], 0L, 1);
 305                         return EXIT_SUCCESS;
 306                 }
 307         }
 308 #if defined(__sparc64__) || defined(__sparc__)
 309         if (!strcmp(p, "sparc32bash")) {
 310                 if (set_arch(p, 0L, 0))
 311                         err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 312                 execl("/bin/bash", NULL);
 313                 err(EXIT_FAILURE, _("failed to execute %s"), "/bin/bash");
 314         }
 315 #endif
 316
 317         while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
 318                 switch (c) {
 319                 case 'h':
 320                         show_help();
 321                         break;
 322                 case 'V':
 323                         show_version();
 324                         break;
 325                 case 'v':
 326                         verbose = 1;
 327                         break;
 328                 case 'R':
 329                         turn_on(ADDR_NO_RANDOMIZE, options);
 330                         break;
 331                 case 'F':
 332                         turn_on(FDPIC_FUNCPTRS, options);
 333                         break;
 334                 case 'Z':
 335                         turn_on(MMAP_PAGE_ZERO, options);
 336                         break;
 337                 case 'L':
 338                         turn_on(ADDR_COMPAT_LAYOUT, options);
 339                         break;
 340                 case 'X':
 341                         turn_on(READ_IMPLIES_EXEC, options);
 342                         break;
 343                 case 'B':
 344                         turn_on(ADDR_LIMIT_32BIT, options);
 345                         break;
 346                 case 'I':
 347                         turn_on(SHORT_INODE, options);
 348                         break;
 349                 case 'S':
 350                         turn_on(WHOLE_SECONDS, options);
 351                         break;
 352                 case 'T':
 353                         turn_on(STICKY_TIMEOUTS, options);
 354                         break;
 355                 case '3':
 356                         turn_on(ADDR_LIMIT_3GB, options);
 357                         break;
 358                 case OPT_4GB:   /* just ignore this one */
 359                         break;
 360                 case OPT_UNAME26:
 361                         turn_on(UNAME26, options);
 362                         break;
 363                 default:
 364                         show_usage(NULL);
 365                 }
 366         }
 367
 368         argc -= optind;
 369         argv += optind;
 370
 371         if (set_arch(p, options, 0))
 372                 err(EXIT_FAILURE, _("Failed to set personality to %s"), p);
 373
 374         /* flush all output streams before exec */
 375         fflush(NULL);
 376
 377         if (!argc) {
 378                 execl("/bin/sh", "-sh", NULL);
 379                 err(EXIT_FAILURE, _("failed to execute %s"), "/bin/sh");
 380         }
 381
 382         execvp(argv[0], argv);
 383         err(EXIT_FAILURE, "%s", argv[0]);
 384         return EXIT_FAILURE;
 385 }