coregrind/launcher-linux.c

   1 /* -*- mode: C; c-basic-offset: 3; -*- */
   2
   3 /*--------------------------------------------------------------------*/
   4 /*--- Launching valgrind                              m_launcher.c ---*/
   5 /*--------------------------------------------------------------------*/
   6
   7 /*
   8    This file is part of Valgrind, a dynamic binary instrumentation
   9    framework.
  10
  11    Copyright (C) 2000-2017 Julian Seward
  12       jseward@acm.org
  13
  14    This program is free software; you can redistribute it and/or
  15    modify it under the terms of the GNU General Public License as
  16    published by the Free Software Foundation; either version 2 of the
  17    License, or (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful, but
  20    WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program; if not, see <http://www.gnu.org/licenses/>.
  26
  27    The GNU General Public License is contained in the file COPYING.
  28 */
  29
  30 /* Note: this is a "normal" program and not part of Valgrind proper,
  31    and so it doesn't have to conform to Valgrind's arcane rules on
  32    no-glibc-usage etc. */
  33
  34 /* Include valgrind headers before system headers to avoid problems
  35    with the system headers #defining things which are used as names
  36    of structure members in vki headers. */
  37
  38 #include "pub_core_debuglog.h"
  39 #include "pub_core_vki.h"       // Avoids warnings from
  40                                 // pub_core_libcfile.h
  41 #include "pub_core_libcproc.h"  // For VALGRIND_LIB, VALGRIND_LAUNCHER
  42 #include "pub_core_ume.h"
  43
  44 #include <assert.h>
  45 #include <ctype.h>
  46 #include <elf.h>
  47 #include <errno.h>
  48 #include <fcntl.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 #ifndef EM_X86_64
  55 #define EM_X86_64 62    // elf.h doesn't define this on some older systems
  56 #endif
  57
  58 #ifndef EM_AARCH64
  59 #define EM_AARCH64 183  // ditto
  60 #endif
  61
  62 #ifndef EM_PPC64
  63 #define EM_PPC64 21  // ditto
  64 #endif
  65
  66 #ifndef EM_NANOMIPS
  67 #define EM_NANOMIPS 249
  68 #endif
  69
  70 #ifndef E_MIPS_ABI_O32
  71 #define E_MIPS_ABI_O32 0x00001000
  72 #endif
  73
  74 #ifndef E_MIPS_ABI2
  75 #define E_MIPS_ABI2    0x00000020
  76 #endif
  77
  78 /* Report fatal errors */
  79 __attribute__((noreturn))
  80 static void barf ( const char *format, ... )
  81 {
  82    va_list vargs;
  83
  84    va_start(vargs, format);
  85    fprintf(stderr, "valgrind: Cannot continue: ");
  86    vfprintf(stderr, format, vargs);
  87    fprintf(stderr, "\n");
  88    va_end(vargs);
  89
  90    exit(1);
  91    /*NOTREACHED*/
  92    assert(0);
  93 }
  94
  95 /* Search the path for the client program */
  96 static char *find_client(const char *clientname)
  97 {
  98    char *fullname;
  99    const char *path = getenv("PATH");
 100    const char *colon;
 101
 102    assert(clientname != NULL);
 103
 104    if (path == NULL) return strdup(clientname);
 105
 106    /* Make the size of the FULLNAME buffer large enough. */
 107    unsigned need = strlen(path) + strlen("/") + strlen(clientname) + 1;
 108
 109    fullname = malloc(need);
 110    if (fullname == NULL)
 111       barf("malloc of fullname failed.");
 112
 113    while (path)
 114    {
 115       if ((colon = strchr(path, ':')) == NULL)
 116       {
 117          strcpy(fullname, path);
 118          path = NULL;
 119       }
 120       else
 121       {
 122          strncpy(fullname, path, colon - path);
 123          fullname[colon - path] = '\0';
 124          path = colon + 1;
 125       }
 126
 127       strcat(fullname, "/");
 128       strcat(fullname, clientname);
 129
 130       if (access(fullname, R_OK|X_OK) == 0)
 131          return fullname;
 132    }
 133    free(fullname);
 134
 135    return strdup(clientname);
 136 }
 137
 138 /* Examine the client and work out which platform it is for */
 139 static const char *select_platform(const char *clientname)
 140 {
 141    int fd;
 142    union {
 143       char c[4096];
 144       Elf32_Ehdr ehdr32;
 145       Elf64_Ehdr ehdr64;
 146    } header;
 147    ssize_t n_bytes;
 148    const char *platform = NULL;
 149    char *client;
 150
 151    VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
 152
 153    if (strchr(clientname, '/') == NULL)
 154       client = find_client(clientname);
 155    else
 156       client = strdup(clientname);
 157
 158    if (strcmp (client, clientname) != 0)
 159       VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", client);
 160
 161    if ((fd = open(client, O_RDONLY)) < 0) {
 162      return_null:
 163       free (client);
 164       return NULL;
 165    }
 166    //   barf("open(%s): %s", clientname, strerror(errno));
 167
 168    VG_(debugLog)(2, "launcher", "opened '%s'\n", client);
 169
 170    n_bytes = read(fd, header.c, sizeof(header));
 171    close(fd);
 172    if (n_bytes < 2) {
 173       goto return_null;
 174    }
 175
 176    VG_(debugLog)(2, "launcher", "read %ld bytes from '%s'\n",
 177                     (long int)n_bytes, client);
 178
 179    if (header.c[0] == '#' && header.c[1] == '!') {
 180       int i = 2;
 181
 182       STATIC_ASSERT(VKI_BINPRM_BUF_SIZE < sizeof header);
 183       if (n_bytes > VKI_BINPRM_BUF_SIZE)
 184          n_bytes = VKI_BINPRM_BUF_SIZE - 1;
 185       header.c[n_bytes] = '\0';
 186       char *eol = strchr(header.c, '\n');
 187       if (eol != NULL)
 188          *eol = '\0';
 189
 190       // Skip whitespace.
 191       while (header.c[i] == ' '|| header.c[i] == '\t')
 192          i++;
 193
 194       // Get the interpreter name.
 195       const char *interp = header.c + i;
 196
 197       if (header.c[i] == '\0') {
 198          // No interpreter was found; fall back to default shell
 199 #  if defined(VGPV_arm_linux_android) \
 200       || defined(VGPV_x86_linux_android) \
 201       || defined(VGPV_mips32_linux_android) \
 202       || defined(VGPV_arm64_linux_android)
 203          interp = "/system/bin/sh";
 204 #  else
 205          interp = "/bin/sh";
 206 #  endif
 207       } else {
 208          while (header.c[i]) {
 209             if (header.c[i] == ' ' || header.c[i] == '\t') break;
 210             i++;
 211          }
 212          header.c[i] = '\0';
 213       }
 214
 215       platform = select_platform(interp);
 216
 217    } else if (n_bytes >= SELFMAG && memcmp(header.c, ELFMAG, SELFMAG) == 0) {
 218
 219       if (n_bytes >= sizeof(Elf32_Ehdr) && header.c[EI_CLASS] == ELFCLASS32) {
 220
 221          if (header.c[EI_DATA] == ELFDATA2LSB) {
 222 #           if defined(VGO_solaris)
 223             if (header.ehdr32.e_machine == EM_386 &&
 224                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 225                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 226                platform = "x86-solaris";
 227             }
 228             else
 229 #           endif
 230             if (header.ehdr32.e_machine == EM_386 &&
 231                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 232                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 233                platform = "x86-linux";
 234             }
 235             else
 236             if (header.ehdr32.e_machine == EM_ARM &&
 237                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 238                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 239                platform = "arm-linux";
 240             }
 241             else
 242             if (header.ehdr32.e_machine == EM_MIPS &&
 243                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 244                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX) &&
 245                  (header.ehdr32.e_flags & E_MIPS_ABI_O32)) {
 246                platform = "mips32-linux";
 247             }
 248             else
 249             if (header.ehdr32.e_machine == EM_MIPS &&
 250                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 251                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX) &&
 252                  (header.ehdr32.e_flags & E_MIPS_ABI2)) {
 253                platform = "mips64-linux";
 254             }
 255             else
 256             if (header.ehdr32.e_machine == EM_NANOMIPS &&
 257                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 258                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 259                platform = "nanomips-linux";
 260             }
 261          }
 262          else if (header.c[EI_DATA] == ELFDATA2MSB) {
 263             if (header.ehdr32.e_machine == EM_PPC &&
 264                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 265                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 266                platform = "ppc32-linux";
 267             }
 268             else
 269             if (header.ehdr32.e_machine == EM_MIPS &&
 270                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 271                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX) &&
 272                  (header.ehdr32.e_flags & E_MIPS_ABI_O32)) {
 273                platform = "mips32-linux";
 274             }
 275             else
 276             if (header.ehdr32.e_machine == EM_MIPS &&
 277                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 278                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX) &&
 279                  (header.ehdr32.e_flags & E_MIPS_ABI2)) {
 280                platform = "mips64-linux";
 281             }
 282             else
 283             if (header.ehdr32.e_machine == EM_NANOMIPS &&
 284                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 285                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 286                platform = "nanomips-linux";
 287             }
 288          }
 289
 290       } else if (n_bytes >= sizeof(Elf64_Ehdr) && header.c[EI_CLASS] == ELFCLASS64) {
 291
 292          if (header.c[EI_DATA] == ELFDATA2LSB) {
 293 #           if defined(VGO_solaris)
 294             if (header.ehdr64.e_machine == EM_X86_64 &&
 295                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 296                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 297                platform = "amd64-solaris";
 298             }
 299             else
 300 #           endif
 301             if (header.ehdr64.e_machine == EM_X86_64 &&
 302                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 303                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 304                platform = "amd64-linux";
 305             } else if (header.ehdr64.e_machine == EM_MIPS &&
 306                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 307                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 308                platform = "mips64-linux";
 309             } else if (header.ehdr64.e_machine == EM_AARCH64 &&
 310                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 311                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 312                platform = "arm64-linux";
 313             } else if (header.ehdr64.e_machine == EM_PPC64 &&
 314                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 315                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 316                platform = "ppc64le-linux";
 317             }
 318          } else if (header.c[EI_DATA] == ELFDATA2MSB) {
 319 #           if !defined(VGPV_arm_linux_android) \
 320                && !defined(VGPV_x86_linux_android) \
 321                && !defined(VGPV_mips32_linux_android) \
 322                && !defined(VGPV_arm64_linux_android)
 323             if (header.ehdr64.e_machine == EM_PPC64 &&
 324                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 325                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 326                platform = "ppc64be-linux";
 327             }
 328             else
 329             if (header.ehdr64.e_machine == EM_S390 &&
 330                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 331                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 332                platform = "s390x-linux";
 333             } else if (header.ehdr64.e_machine == EM_MIPS &&
 334                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 335                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 336                platform = "mips64-linux";
 337             }
 338 #           endif
 339          }
 340       }
 341    }
 342
 343    VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
 344                  platform ? platform : "unknown");
 345
 346    free (client);
 347
 348    return platform;
 349 }
 350
 351 /* Where we expect to find all our aux files */
 352 static const char *valgrind_lib = VG_LIBDIR;
 353
 354 int main(int argc, char** argv, char** envp)
 355 {
 356    int i, j, loglevel, r;
 357    const char *toolname = NULL;
 358    const char *clientname = NULL;
 359    const char *platform;
 360    const char *default_platform;
 361    const char *cp;
 362    const char *linkname;
 363    char *toolfile;
 364    const char *launcher_name;
 365    char* new_line;
 366    char** new_env;
 367
 368    /* Start the debugging-log system ASAP.  First find out how many
 369       "-d"s were specified.  This is a pre-scan of the command line.
 370       At the same time, look for the tool name. */
 371    loglevel = 0;
 372    for (i = 1; i < argc; i++) {
 373       if (argv[i][0] != '-') {
 374          clientname = argv[i];
 375          break;
 376       }
 377       if (0 == strcmp(argv[i], "--")) {
 378          if (i+1 < argc)
 379             clientname = argv[i+1];
 380          break;
 381       }
 382       if (0 == strcmp(argv[i], "-d"))
 383          loglevel++;
 384       if (0 == strncmp(argv[i], "--tool=", 7))
 385          toolname = argv[i] + 7;
 386    }
 387
 388    /* ... and start the debug logger.  Now we can safely emit logging
 389       messages all through startup. */
 390    VG_(debugLog_startup)(loglevel, "Stage 1");
 391
 392    /* Make sure we know which tool we're using */
 393    if (toolname) {
 394       VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
 395    } else {
 396       VG_(debugLog)(1, "launcher",
 397                        "no tool requested, defaulting to 'memcheck'\n");
 398       toolname = "memcheck";
 399    }
 400
 401    /* Select a platform to use if we can't decide that by looking at
 402       the executable (eg because it's a shell script).  VG_PLATFORM is the
 403       default_platform. Its value is defined in coregrind/Makefile.am and
 404       typically it is the primary build target. Unless the primary build
 405       target is not built is not built in which case VG_PLATFORM is the
 406       secondary build target. */
 407 #  if defined(VGO_linux)
 408    if ((0==strcmp(VG_PLATFORM,"x86-linux"))    ||
 409        (0==strcmp(VG_PLATFORM,"amd64-linux"))  ||
 410        (0==strcmp(VG_PLATFORM,"ppc32-linux"))  ||
 411        (0==strcmp(VG_PLATFORM,"ppc64be-linux"))  ||
 412        (0==strcmp(VG_PLATFORM,"ppc64le-linux"))  ||
 413        (0==strcmp(VG_PLATFORM,"arm-linux"))    ||
 414        (0==strcmp(VG_PLATFORM,"arm64-linux"))  ||
 415        (0==strcmp(VG_PLATFORM,"s390x-linux"))  ||
 416        (0==strcmp(VG_PLATFORM,"mips32-linux")) ||
 417        (0==strcmp(VG_PLATFORM,"mips64-linux")) ||
 418        (0==strcmp(VG_PLATFORM,"nanomips-linux")))
 419       default_platform = VG_PLATFORM;
 420 #  elif defined(VGO_solaris)
 421    if ((0==strcmp(VG_PLATFORM,"x86-solaris")) ||
 422        (0==strcmp(VG_PLATFORM,"amd64-solaris")))
 423       default_platform = SOLARIS_LAUNCHER_DEFAULT_PLATFORM;
 424 #  else
 425 #    error Unknown OS
 426 #  endif
 427    else
 428       barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
 429
 430    /* Work out what platform to use, or use the default platform if
 431       not possible. */
 432    if (clientname == NULL) {
 433       VG_(debugLog)(1, "launcher",
 434                        "no client specified, defaulting platform to '%s'\n",
 435                         default_platform);
 436       platform = default_platform;
 437    } else if ((platform = select_platform(clientname)) != NULL) {
 438       VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
 439    } else {
 440       VG_(debugLog)(1, "launcher",
 441                        "no platform detected, defaulting platform to '%s'\n",
 442                        default_platform);
 443       platform = default_platform;
 444    }
 445
 446    /* Figure out the name of this executable (viz, the launcher), so
 447       we can tell stage2.  stage2 will use the name for recursive
 448       invocations of valgrind on child processes. */
 449 #  if defined(VGO_linux)
 450    linkname = "/proc/self/exe";
 451 #  elif defined(VGO_solaris)
 452    linkname = "/proc/self/path/a.out";
 453 #  else
 454 #    error Unknown OS
 455 #  endif
 456    unsigned bufsiz = 0;
 457    char *buf = NULL;
 458
 459    while (42) {
 460       bufsiz += 500;
 461       buf = realloc(buf, bufsiz);
 462       if (buf == NULL)
 463          barf("realloc of buf failed.");
 464       r = readlink(linkname, buf, bufsiz);
 465       if (r == -1) {
 466         /* If /proc/self/exe (/proc/self/path/a.out) can't be followed, don't
 467            give up. Instead continue with an empty string for VALGRIND_LAUNCHER.
 468            In the sys_execve wrapper, this is tested, and if found to be empty,
 469            fail the execve. */
 470         fprintf(stderr, "valgrind: warning (non-fatal): "
 471                 "readlink(\"%s\") failed.\n", linkname);
 472         fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
 473                 "will not work.\n");
 474         launcher_name = "";
 475         break;
 476       }
 477       if (r == bufsiz) continue;   // buffer to small; retry
 478
 479       assert(r < bufsiz);   // paranoia
 480
 481       buf[r] = '\0';
 482       launcher_name = buf;
 483       break;
 484    }
 485
 486    /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
 487    new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
 488                      + strlen(launcher_name) + 1);
 489    if (new_line == NULL)
 490       barf("malloc of new_line failed.");
 491    strcpy(new_line, VALGRIND_LAUNCHER);
 492    strcat(new_line, "=");
 493    strcat(new_line, launcher_name);
 494
 495    for (j = 0; envp[j]; j++)
 496       ;
 497    new_env = malloc((j+2) * sizeof(char*));
 498    if (new_env == NULL)
 499       barf("malloc of new_env failed.");
 500    for (i = 0; i < j; i++)
 501       new_env[i] = envp[i];
 502    new_env[i++] = new_line;
 503    new_env[i++] = NULL;
 504    assert(i == j+2);
 505
 506    /* Establish the correct VALGRIND_LIB. */
 507    cp = getenv(VALGRIND_LIB);
 508
 509    if (cp != NULL)
 510       valgrind_lib = cp;
 511
 512    /* Build the stage2 invocation, and execve it.  Bye! */
 513    toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
 514    if (toolfile == NULL)
 515       barf("malloc of toolfile failed.");
 516    sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
 517
 518    VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
 519
 520    execve(toolfile, argv, new_env);
 521
 522    fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
 523                    toolname, platform, strerror(errno));
 524
 525    exit(1);
 526 }