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 #include "sysfs.h"
  39 #include "strutils.h"
  40
  41 #ifndef HAVE_PERSONALITY
  42 # include <syscall.h>
  43 # define personality(pers) ((long)syscall(SYS_personality, pers))
  44 #endif
  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 #ifndef UNAME26
  54 # define UNAME26                 0x0020000
  55 #endif
  56 #ifndef ADDR_NO_RANDOMIZE
  57 # define ADDR_NO_RANDOMIZE       0x0040000
  58 #endif
  59 #ifndef FDPIC_FUNCPTRS
  60 # define FDPIC_FUNCPTRS          0x0080000
  61 #endif
  62 #ifndef MMAP_PAGE_ZERO
  63 # define MMAP_PAGE_ZERO          0x0100000
  64 #endif
  65 #ifndef ADDR_COMPAT_LAYOUT
  66 # define ADDR_COMPAT_LAYOUT      0x0200000
  67 #endif
  68 #ifndef READ_IMPLIES_EXEC
  69 # define READ_IMPLIES_EXEC       0x0400000
  70 #endif
  71 #ifndef ADDR_LIMIT_32BIT
  72 # define ADDR_LIMIT_32BIT        0x0800000
  73 #endif
  74 #ifndef SHORT_INODE
  75 # define SHORT_INODE             0x1000000
  76 #endif
  77 #ifndef WHOLE_SECONDS
  78 # define WHOLE_SECONDS           0x2000000
  79 #endif
  80 #ifndef STICKY_TIMEOUTS
  81 # define STICKY_TIMEOUTS         0x4000000
  82 #endif
  83 #ifndef ADDR_LIMIT_3GB
  84 # define ADDR_LIMIT_3GB          0x8000000
  85 #endif
  86
  87 /* fallback for old glibc-headers 2.17 */
  88 #ifndef PER_LINUX_FDPIC
  89 # define PER_LINUX_FDPIC        (PER_LINUX | FDPIC_FUNCPTRS)
  90 #endif
  91
  92 #define ALL_PERSONALITIES \
  93     X(PER_LINUX) \
  94     X(PER_LINUX_32BIT) \
  95     X(PER_LINUX_FDPIC) \
  96     X(PER_SVR4) \
  97     X(PER_SVR3) \
  98     X(PER_SCOSVR3) \
  99     X(PER_OSR5) \
 100     X(PER_WYSEV386) \
 101     X(PER_ISCR4) \
 102     X(PER_BSD) \
 103     X(PER_SUNOS) \
 104     X(PER_XENIX) \
 105     X(PER_LINUX32) \
 106     X(PER_LINUX32_3GB) \
 107     X(PER_IRIX32) \
 108     X(PER_IRIXN32) \
 109     X(PER_IRIX64) \
 110     X(PER_RISCOS) \
 111     X(PER_SOLARIS) \
 112     X(PER_UW7) \
 113     X(PER_OSF4) \
 114     X(PER_HPUX) \
 115
 116
 117 #define ALL_OPTIONS \
 118     X(UNAME26) \
 119     X(ADDR_NO_RANDOMIZE) \
 120     X(FDPIC_FUNCPTRS) \
 121     X(MMAP_PAGE_ZERO) \
 122     X(ADDR_COMPAT_LAYOUT) \
 123     X(READ_IMPLIES_EXEC) \
 124     X(ADDR_LIMIT_32BIT) \
 125     X(SHORT_INODE) \
 126     X(WHOLE_SECONDS) \
 127     X(STICKY_TIMEOUTS) \
 128     X(ADDR_LIMIT_3GB) \
 129
 130
 131 struct arch_domain {
 132         int             perval;         /* PER_* */
 133         const char      *target_arch;
 134         const char      *result_arch;
 135 };
 136
 137
 138 static void __attribute__((__noreturn__)) usage(int archwrapper)
 139 {
 140         fputs(USAGE_HEADER, stdout);
 141         if (!archwrapper)
 142                 fprintf(stdout, _(" %s [<arch>] [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
 143         else
 144                 fprintf(stdout, _(" %s [options] [<program> [<argument>...]]\n"), program_invocation_short_name);
 145
 146         fputs(USAGE_SEPARATOR, stdout);
 147         fputs(_("Change the reported architecture and set personality flags.\n"), stdout);
 148
 149         fputs(USAGE_OPTIONS, stdout);
 150         fputs(_(" -B, --32bit              turns on ADDR_LIMIT_32BIT\n"), stdout);
 151         fputs(_(" -F, --fdpic-funcptrs     makes function pointers point to descriptors\n"), stdout);
 152         fputs(_(" -I, --short-inode        turns on SHORT_INODE\n"), stdout);
 153         fputs(_(" -L, --addr-compat-layout changes the way virtual memory is allocated\n"), stdout);
 154         fputs(_(" -R, --addr-no-randomize  disables randomization of the virtual address space\n"), stdout);
 155         fputs(_(" -S, --whole-seconds      turns on WHOLE_SECONDS\n"), stdout);
 156         fputs(_(" -T, --sticky-timeouts    turns on STICKY_TIMEOUTS\n"), stdout);
 157         fputs(_(" -X, --read-implies-exec  turns on READ_IMPLIES_EXEC\n"), stdout);
 158         fputs(_(" -Z, --mmap-page-zero     turns on MMAP_PAGE_ZERO\n"), stdout);
 159         fputs(_(" -3, --3gb                limits the used address space to a maximum of 3 GB\n"), stdout);
 160         fputs(_("     --4gb                ignored (for backward compatibility only)\n"), stdout);
 161         fputs(_("     --uname-2.6          turns on UNAME26\n"), stdout);
 162         fputs(_(" -v, --verbose            say what options are being switched on\n"), stdout);
 163
 164         if (!archwrapper) {
 165                 fputs(_("     --list               list settable architectures, and exit\n"), stdout);
 166                 fputs(_("     --show[=personality] show current or specific personality and exit\n"), stdout);
 167         }
 168
 169         fputs(USAGE_SEPARATOR, stdout);
 170         fprintf(stdout, USAGE_HELP_OPTIONS(26));
 171         fprintf(stdout, USAGE_MAN_TAIL("setarch(8)"));
 172
 173         exit(EXIT_SUCCESS);
 174 }
 175
 176 /*
 177  * Returns inilialized list of all available execution domains.
 178  */
 179 static struct arch_domain *init_arch_domains(void)
 180 {
 181         static struct utsname un;
 182         size_t i;
 183
 184         static struct arch_domain transitions[] =
 185         {
 186                 {UNAME26,       "uname26",      NULL},
 187                 {PER_LINUX32,   "linux32",      NULL},
 188                 {PER_LINUX,     "linux64",      NULL},
 189 #if defined(__powerpc__) || defined(__powerpc64__)
 190 # ifdef __BIG_ENDIAN__
 191                 {PER_LINUX32,   "ppc32",        "ppc"},
 192                 {PER_LINUX32,   "ppc",          "ppc"},
 193                 {PER_LINUX,     "ppc64",        "ppc64"},
 194                 {PER_LINUX,     "ppc64pseries", "ppc64"},
 195                 {PER_LINUX,     "ppc64iseries", "ppc64"},
 196 # else
 197                 {PER_LINUX32,   "ppc32",        "ppcle"},
 198                 {PER_LINUX32,   "ppc",          "ppcle"},
 199                 {PER_LINUX32,   "ppc32le",      "ppcle"},
 200                 {PER_LINUX32,   "ppcle",        "ppcle"},
 201                 {PER_LINUX,     "ppc64le",      "ppc64le"},
 202 # endif
 203 #endif
 204 #if defined(__x86_64__) || defined(__i386__) || defined(__ia64__)
 205                 {PER_LINUX32,   "i386",         "i386"},
 206                 {PER_LINUX32,   "i486",         "i386"},
 207                 {PER_LINUX32,   "i586",         "i386"},
 208                 {PER_LINUX32,   "i686",         "i386"},
 209                 {PER_LINUX32,   "athlon",       "i386"},
 210 #endif
 211 #if defined(__x86_64__) || defined(__i386__)
 212                 {PER_LINUX,     "x86_64",       "x86_64"},
 213 #endif
 214 #if defined(__ia64__) || defined(__i386__)
 215                 {PER_LINUX,     "ia64",         "ia64"},
 216 #endif
 217 #if defined(__hppa__)
 218                 {PER_LINUX32,   "parisc32",     "parisc"},
 219                 {PER_LINUX32,   "parisc",       "parisc"},
 220                 {PER_LINUX,     "parisc64",     "parisc64"},
 221 #endif
 222 #if defined(__s390x__) || defined(__s390__)
 223                 {PER_LINUX32,   "s390",         "s390"},
 224                 {PER_LINUX,     "s390x",        "s390x"},
 225 #endif
 226 #if defined(__sparc64__) || defined(__sparc__)
 227                 {PER_LINUX32,   "sparc",        "sparc"},
 228                 {PER_LINUX32,   "sparc32bash",  "sparc"},
 229                 {PER_LINUX32,   "sparc32",      "sparc"},
 230                 {PER_LINUX,     "sparc64",      "sparc64"},
 231 #endif
 232 #if defined(__mips64__) || defined(__mips__)
 233                 {PER_LINUX32,   "mips32",       "mips"},
 234                 {PER_LINUX32,   "mips",         "mips"},
 235                 {PER_LINUX,     "mips64",       "mips64"},
 236 #endif
 237 #if defined(__alpha__)
 238                 {PER_LINUX,     "alpha",        "alpha"},
 239                 {PER_LINUX,     "alphaev5",     "alpha"},
 240                 {PER_LINUX,     "alphaev56",    "alpha"},
 241                 {PER_LINUX,     "alphaev6",     "alpha"},
 242                 {PER_LINUX,     "alphaev67",    "alpha"},
 243 #endif
 244 #if defined(__loongarch__)
 245                 {PER_LINUX,     "loongarch",    "loongarch64"},
 246                 {PER_LINUX,     "loongarch64",  "loongarch64"},
 247 #endif
 248 #if defined(__e2k__)
 249                 {PER_LINUX,     "e2k",      "e2k"},
 250                 {PER_LINUX,     "e2kv4",        "e2k"},
 251                 {PER_LINUX,     "e2kv5",        "e2k"},
 252                 {PER_LINUX,     "e2kv6",        "e2k"},
 253                 {PER_LINUX,     "e2k4c",        "e2k"},
 254                 {PER_LINUX,     "e2k8c",        "e2k"},
 255                 {PER_LINUX,     "e2k1cp",       "e2k"},
 256                 {PER_LINUX,     "e2k8c2",       "e2k"},
 257                 {PER_LINUX,     "e2k12c",       "e2k"},
 258                 {PER_LINUX,     "e2k16c",       "e2k"},
 259                 {PER_LINUX,     "e2k2c3",       "e2k"},
 260 #endif
 261 #if defined(__arm__) || defined(__aarch64__)
 262 # ifdef __BIG_ENDIAN__
 263                 {PER_LINUX32,   "armv7b",       "arm"},
 264                 {PER_LINUX32,   "armv8b",       "arm"},
 265 # else
 266                 {PER_LINUX32,   "armv7l",       "arm"},
 267                 {PER_LINUX32,   "armv8l",       "arm"},
 268 # endif
 269                 {PER_LINUX32,   "armh",         "arm"},
 270                 {PER_LINUX32,   "arm",          "arm"},
 271                 {PER_LINUX,     "arm64",        "aarch64"},
 272                 {PER_LINUX,     "aarch64",      "aarch64"},
 273 #endif
 274 #if defined(__riscv)
 275                 {PER_LINUX32,   "riscv32",      "riscv32"},
 276                 {PER_LINUX32,   "rv32", "riscv32"},
 277                 {PER_LINUX,     "riscv64",      "riscv64"},
 278                 {PER_LINUX,     "rv64", "riscv64"},
 279 #endif
 280                 /* place holder, will be filled up at runtime */
 281                 {-1,            NULL,           NULL},
 282                 {-1,            NULL,           NULL}
 283         };
 284
 285         /* Add the trivial transition {PER_LINUX, machine, machine} if no
 286          * such target_arch is hardcoded yet.  */
 287         uname(&un);
 288         for (i = 0; transitions[i].perval >= 0; i++)
 289                 if (!strcmp(un.machine, transitions[i].target_arch))
 290                         break;
 291         if (transitions[i].perval < 0) {
 292                 int wrdsz = sysfs_get_address_bits(NULL);
 293                 if (wrdsz < 0)
 294                         wrdsz = CHAR_BIT * sizeof(void *);
 295                 if (wrdsz == 32 || wrdsz == 64) {
 296                         /* fill up the place holder */
 297                         transitions[i].perval = wrdsz == 32 ? PER_LINUX32 : PER_LINUX;
 298                         transitions[i].target_arch = un.machine;
 299                         transitions[i].result_arch = un.machine;
 300                 }
 301         }
 302
 303         return transitions;
 304 }
 305
 306 /*
 307  * List all execution domains from transitions
 308  */
 309 static void list_arch_domains(struct arch_domain *doms)
 310 {
 311         struct arch_domain *d;
 312
 313         for (d = doms; d->target_arch != NULL; d++)
 314                 printf("%s\n", d->target_arch);
 315 }
 316
 317 static struct arch_domain *get_arch_domain(struct arch_domain *doms, const char *pers)
 318 {
 319         struct arch_domain *d;
 320
 321         for (d = doms; d && d->perval >= 0; d++) {
 322                 if (!strcmp(pers, d->target_arch))
 323                         break;
 324         }
 325
 326         return !d || d->perval < 0 ? NULL : d;
 327 }
 328
 329 static void verify_arch_domain(struct arch_domain *doms, struct arch_domain *target, const char *wanted)
 330 {
 331         struct utsname un;
 332
 333         if (!doms || !target || !target->result_arch)
 334                 return;
 335
 336         uname(&un);
 337
 338         if (!strcmp(un.machine, target->result_arch))
 339                 return;
 340
 341         if (!strcmp(target->result_arch, "i386") ||
 342             !strcmp(target->result_arch, "arm")) {
 343                 struct arch_domain *dom;
 344                 for (dom = doms; dom->target_arch != NULL; dom++) {
 345                         if (!dom->result_arch || strcmp(dom->result_arch, target->result_arch))
 346                                 continue;
 347                         if (!strcmp(dom->target_arch, un.machine))
 348                                 return;
 349                 }
 350         }
 351
 352         errx(EXIT_FAILURE, _("Kernel cannot set architecture to %s"), wanted);
 353 }
 354
 355 static const struct { int value; const char * const name; } all_personalities[] = {
 356 #define X(opt) { .value = opt, .name = #opt },
 357         ALL_PERSONALITIES
 358 #undef X
 359 };
 360
 361 static const struct { int value; const char * const name; } all_options[] = {
 362 #define X(opt) { .value = opt, .name = #opt },
 363         ALL_OPTIONS
 364 #undef X
 365 };
 366
 367 static void show_personality(int pers)
 368 {
 369         int options;
 370         size_t i;
 371
 372         /* Test for exact matches including options */
 373         for (i = 0; i < ARRAY_SIZE(all_personalities); i++) {
 374                 if (pers == all_personalities[i].value) {
 375                         printf("%s\n", all_personalities[i].name);
 376                         return;
 377                 }
 378         }
 379
 380         options = pers & ~PER_MASK;
 381         pers &= PER_MASK;
 382
 383         /* Second test for type-only matches */
 384         for (i = 0; i < ARRAY_SIZE(all_personalities); i++) {
 385                 if (pers == all_personalities[i].value) {
 386                         printf("%s", all_personalities[i].name);
 387                         break;
 388                 }
 389         }
 390
 391         if (i == ARRAY_SIZE(all_personalities))
 392                 printf("0x%02x", pers);
 393
 394         if (options) {
 395                 printf(" (");
 396
 397                 for (i = 0; i < ARRAY_SIZE(all_options); i++) {
 398                         if (options & all_options[i].value) {
 399                                 printf("%s", all_options[i].name);
 400
 401                                 options &= ~all_options[i].value;
 402                                 if (options)
 403                                         printf(" ");
 404                         }
 405                 }
 406                 if (options)
 407                         printf("0x%08x", options);
 408                 printf(")");
 409         }
 410         printf("\n");
 411 }
 412
 413 static void show_current_personality(void)
 414 {
 415         int pers = personality(0xffffffff);
 416         if (pers == -1)
 417                 err(EXIT_FAILURE, _("Can not get current kernel personality"));
 418
 419         show_personality(pers);
 420 }
 421
 422 int main(int argc, char *argv[])
 423 {
 424         const char *arch = NULL;
 425         unsigned long options = 0;
 426         int verbose = 0;
 427         int archwrapper;
 428         int c;
 429         struct arch_domain *doms = NULL, *target = NULL;
 430         unsigned long pers_value = 0;
 431         char *shell = NULL, *shell_arg = NULL;
 432
 433         /* Options without equivalent short options */
 434         enum {
 435                 OPT_4GB = CHAR_MAX + 1,
 436                 OPT_UNAME26,
 437                 OPT_LIST,
 438                 OPT_SHOW,
 439         };
 440
 441         /* Options --3gb and --4gb are for compatibility with an old
 442          * Debian setarch implementation.  */
 443         static const struct option longopts[] = {
 444                 {"help",                no_argument,            NULL,   'h'},
 445                 {"version",             no_argument,            NULL,   'V'},
 446                 {"verbose",             no_argument,            NULL,   'v'},
 447                 {"addr-no-randomize",   no_argument,            NULL,   'R'},
 448                 {"fdpic-funcptrs",      no_argument,            NULL,   'F'},
 449                 {"mmap-page-zero",      no_argument,            NULL,   'Z'},
 450                 {"addr-compat-layout",  no_argument,            NULL,   'L'},
 451                 {"read-implies-exec",   no_argument,            NULL,   'X'},
 452                 {"32bit",               no_argument,            NULL,   'B'},
 453                 {"short-inode",         no_argument,            NULL,   'I'},
 454                 {"whole-seconds",       no_argument,            NULL,   'S'},
 455                 {"sticky-timeouts",     no_argument,            NULL,   'T'},
 456                 {"3gb",                 no_argument,            NULL,   '3'},
 457                 {"4gb",                 no_argument,            NULL,   OPT_4GB},
 458                 {"uname-2.6",           no_argument,            NULL,   OPT_UNAME26},
 459                 {"list",                no_argument,            NULL,   OPT_LIST},
 460                 {"show",                optional_argument,      NULL,   OPT_SHOW},
 461                 {NULL,                  0,                      NULL,   0}
 462         };
 463
 464         setlocale(LC_ALL, "");
 465         bindtextdomain(PACKAGE, LOCALEDIR);
 466         textdomain(PACKAGE);
 467         close_stdout_atexit();
 468
 469         if (argc < 1) {
 470                 warnx(_("Not enough arguments"));
 471                 errtryhelp(EXIT_FAILURE);
 472         }
 473         archwrapper = strcmp(program_invocation_short_name, "setarch") != 0;
 474         if (archwrapper) {
 475                 arch = program_invocation_short_name;   /* symlinks to setarch */
 476
 477                 /* Don't use ifdef sparc here, we get "Unrecognized architecture"
 478                  * error message later if necessary */
 479                 if (strcmp(arch, "sparc32bash") == 0) {
 480                         shell = "/bin/bash";
 481                         shell_arg = "";
 482                         goto set_arch;
 483                 }
 484         } else {
 485                 if (1 < argc && *argv[1] != '-') {
 486                         arch = argv[1];
 487                         argv[1] = argv[0];      /* for getopt_long() to get the program name */
 488                         argv++;
 489                         argc--;
 490                 }
 491         }
 492
 493         while ((c = getopt_long(argc, argv, "+hVv3BFILRSTXZ", longopts, NULL)) != -1) {
 494                 switch (c) {
 495                 case 'v':
 496                         verbose = 1;
 497                         break;
 498                 case 'R':
 499                         turn_on(ADDR_NO_RANDOMIZE, options);
 500                         break;
 501                 case 'F':
 502                         turn_on(FDPIC_FUNCPTRS, options);
 503                         break;
 504                 case 'Z':
 505                         turn_on(MMAP_PAGE_ZERO, options);
 506                         break;
 507                 case 'L':
 508                         turn_on(ADDR_COMPAT_LAYOUT, options);
 509                         break;
 510                 case 'X':
 511                         turn_on(READ_IMPLIES_EXEC, options);
 512                         break;
 513                 case 'B':
 514                         turn_on(ADDR_LIMIT_32BIT, options);
 515                         break;
 516                 case 'I':
 517                         turn_on(SHORT_INODE, options);
 518                         break;
 519                 case 'S':
 520                         turn_on(WHOLE_SECONDS, options);
 521                         break;
 522                 case 'T':
 523                         turn_on(STICKY_TIMEOUTS, options);
 524                         break;
 525                 case '3':
 526                         turn_on(ADDR_LIMIT_3GB, options);
 527                         break;
 528                 case OPT_4GB:   /* just ignore this one */
 529                         break;
 530                 case OPT_UNAME26:
 531                         turn_on(UNAME26, options);
 532                         break;
 533                 case OPT_LIST:
 534                         if (!archwrapper) {
 535                                 list_arch_domains(init_arch_domains());
 536                                 return EXIT_SUCCESS;
 537                         } else
 538                                 warnx(_("unrecognized option '--list'"));
 539                         goto error_getopts;
 540                 case OPT_SHOW:
 541                         if (!archwrapper) {
 542                                 if (!optarg || strcmp(optarg, "current") == 0)
 543                                         show_current_personality();
 544                                 else
 545                                         show_personality(str2num_or_err(
 546                                                 optarg, 16,
 547                                                 _("could not parse personality"),
 548                                                 0, INT_MAX));
 549                                 return EXIT_SUCCESS;
 550                         } else
 551                                 warnx(_("unrecognized option '--show'"));
 552                         goto error_getopts;
 553
 554 error_getopts:
 555                 default:
 556                         errtryhelp(EXIT_FAILURE);
 557                 case 'h':
 558                         usage(archwrapper);
 559                 case 'V':
 560                         print_version(EXIT_SUCCESS);
 561                 }
 562         }
 563
 564         if (!arch && !options)
 565                 errx(EXIT_FAILURE, _("no architecture argument or personality flags specified"));
 566
 567         argc -= optind;
 568         argv += optind;
 569
 570 set_arch:
 571         /* get execution domain (architecture) */
 572         if (arch) {
 573                 doms = init_arch_domains();
 574                 target = get_arch_domain(doms, arch);
 575
 576                 if (!target)
 577                         errx(EXIT_FAILURE, _("%s: Unrecognized architecture"), arch);
 578                 pers_value = target->perval;
 579         }
 580
 581         /* add personality flags */
 582         pers_value |= options;
 583
 584         /* call kernel */
 585         if (personality(pers_value) < 0) {
 586                 /*
 587                  * Depending on architecture and kernel version, personality
 588                  * syscall is either capable or incapable of returning an error.
 589                  * If the return value is not an error, then it's the previous
 590                  * personality value, which can be an arbitrary value
 591                  * undistinguishable from an error value.
 592                  * To make things clear, a second call is needed.
 593                  */
 594                 if (personality(pers_value) < 0)
 595                         err(EXIT_FAILURE, _("failed to set personality to %s"), arch);
 596         }
 597
 598         /* make sure architecture is set as expected */
 599         if (arch)
 600                 verify_arch_domain(doms, target, arch);
 601
 602         if (!argc) {
 603                 shell = "/bin/sh";
 604                 shell_arg = "-sh";
 605         }
 606         if (verbose) {
 607                 printf(_("Execute command `%s'.\n"), shell ? shell : argv[0]);
 608                 /* flush all output streams before exec */
 609                 fflush(NULL);
 610         }
 611
 612         /* Execute shell */
 613         if (shell) {
 614                 execl(shell, shell_arg, (char *)NULL);
 615                 errexec(shell);
 616         }
 617
 618         /* Execute on command line specified command */
 619         execvp(argv[0], argv);
 620         errexec(argv[0]);
 621 }