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