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, write to the Free Software
  26    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  27    02111-1307, USA.
  28
  29    The GNU General Public License is contained in the file COPYING.
  30 */
  31
  32 /* Note: this is a "normal" program and not part of Valgrind proper,
  33    and so it doesn't have to conform to Valgrind's arcane rules on
  34    no-glibc-usage etc. */
  35
  36 /* Include valgrind headers before system headers to avoid problems
  37    with the system headers #defining things which are used as names
  38    of structure members in vki headers. */
  39
  40 #include "pub_core_debuglog.h"
  41 #include "pub_core_vki.h"       // Avoids warnings from
  42                                 // pub_core_libcfile.h
  43 #include "pub_core_libcproc.h"  // For VALGRIND_LIB, VALGRIND_LAUNCHER
  44 #include "pub_core_ume.h"
  45
  46 #include <assert.h>
  47 #include <ctype.h>
  48 #include <elf.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 #ifndef EM_X86_64
  57 #define EM_X86_64 62    // elf.h doesn't define this on some older systems
  58 #endif
  59
  60 #ifndef EM_AARCH64
  61 #define EM_AARCH64 183  // ditto
  62 #endif
  63
  64 #ifndef EM_PPC64
  65 #define EM_PPC64 21  // ditto
  66 #endif
  67
  68 /* Report fatal errors */
  69 __attribute__((noreturn))
  70 static void barf ( const char *format, ... )
  71 {
  72    va_list vargs;
  73
  74    va_start(vargs, format);
  75    fprintf(stderr, "valgrind: Cannot continue: ");
  76    vfprintf(stderr, format, vargs);
  77    fprintf(stderr, "\n");
  78    va_end(vargs);
  79
  80    exit(1);
  81    /*NOTREACHED*/
  82    assert(0);
  83 }
  84
  85 /* Search the path for the client program */
  86 static const char *find_client(const char *clientname)
  87 {
  88    char *fullname;
  89    const char *path = getenv("PATH");
  90    const char *colon;
  91
  92    assert(clientname != NULL);
  93
  94    if (path == NULL) return clientname;
  95
  96    /* Make the size of the FULLNAME buffer large enough. */
  97    unsigned need = strlen(path) + strlen("/") + strlen(clientname) + 1;
  98
  99    fullname = malloc(need);
 100    if (fullname == NULL)
 101       barf("malloc of fullname failed.");
 102
 103    while (path)
 104    {
 105       if ((colon = strchr(path, ':')) == NULL)
 106       {
 107          strcpy(fullname, path);
 108          path = NULL;
 109       }
 110       else
 111       {
 112          strncpy(fullname, path, colon - path);
 113          fullname[colon - path] = '\0';
 114          path = colon + 1;
 115       }
 116
 117       strcat(fullname, "/");
 118       strcat(fullname, clientname);
 119
 120       if (access(fullname, R_OK|X_OK) == 0)
 121          return fullname;
 122    }
 123    free(fullname);
 124
 125    return clientname;
 126 }
 127
 128 /* Examine the client and work out which platform it is for */
 129 static const char *select_platform(const char *clientname)
 130 {
 131    int fd;
 132    union {
 133       char c[4096];
 134       Elf32_Ehdr ehdr32;
 135       Elf64_Ehdr ehdr64;
 136    } header;
 137    ssize_t n_bytes;
 138    const char *platform = NULL;
 139
 140    VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
 141
 142    if (strchr(clientname, '/') == NULL)
 143       clientname = find_client(clientname);
 144
 145    VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
 146
 147    if ((fd = open(clientname, O_RDONLY)) < 0)
 148       return NULL;
 149    //   barf("open(%s): %s", clientname, strerror(errno));
 150
 151    VG_(debugLog)(2, "launcher", "opened '%s'\n", clientname);
 152
 153    n_bytes = read(fd, header.c, sizeof(header));
 154    close(fd);
 155    if (n_bytes < 2) {
 156       return NULL;
 157    }
 158
 159    VG_(debugLog)(2, "launcher", "read %ld bytes from '%s'\n",
 160                     (long int)n_bytes, clientname);
 161
 162    if (header.c[0] == '#' && header.c[1] == '!') {
 163       int i = 2;
 164
 165       STATIC_ASSERT(VKI_BINPRM_BUF_SIZE < sizeof header);
 166       if (n_bytes > VKI_BINPRM_BUF_SIZE)
 167          n_bytes = VKI_BINPRM_BUF_SIZE - 1;
 168       header.c[n_bytes] = '\0';
 169       char *eol = strchr(header.c, '\n');
 170       if (eol != NULL)
 171          *eol = '\0';
 172
 173       // Skip whitespace.
 174       while (header.c[i] == ' '|| header.c[i] == '\t')
 175          i++;
 176
 177       // Get the interpreter name.
 178       const char *interp = header.c + i;
 179
 180       if (header.c[i] == '\0') {
 181          // No interpreter was found; fall back to default shell
 182 #  if defined(VGPV_arm_linux_android) \
 183       || defined(VGPV_x86_linux_android) \
 184       || defined(VGPV_mips32_linux_android) \
 185       || defined(VGPV_arm64_linux_android)
 186          interp = "/system/bin/sh";
 187 #  else
 188          interp = "/bin/sh";
 189 #  endif
 190       } else {
 191          while (header.c[i]) {
 192             if (header.c[i] == ' ' || header.c[i] == '\t') break;
 193             i++;
 194          }
 195          header.c[i] = '\0';
 196       }
 197
 198       platform = select_platform(interp);
 199
 200    } else if (n_bytes >= SELFMAG && memcmp(header.c, ELFMAG, SELFMAG) == 0) {
 201
 202       if (n_bytes >= sizeof(Elf32_Ehdr) && header.c[EI_CLASS] == ELFCLASS32) {
 203
 204          if (header.c[EI_DATA] == ELFDATA2LSB) {
 205 #           if defined(VGO_solaris)
 206             if (header.ehdr32.e_machine == EM_386 &&
 207                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 208                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 209                platform = "x86-solaris";
 210             }
 211             else
 212 #           endif
 213             if (header.ehdr32.e_machine == EM_386 &&
 214                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 215                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 216                platform = "x86-linux";
 217             }
 218             else
 219             if (header.ehdr32.e_machine == EM_ARM &&
 220                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 221                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 222                platform = "arm-linux";
 223             }
 224             else
 225             if (header.ehdr32.e_machine == EM_MIPS &&
 226                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 227                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 228                platform = "mips32-linux";
 229             }
 230          }
 231          else if (header.c[EI_DATA] == ELFDATA2MSB) {
 232             if (header.ehdr32.e_machine == EM_PPC &&
 233                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 234                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 235                platform = "ppc32-linux";
 236             }
 237             else
 238             if (header.ehdr32.e_machine == EM_MIPS &&
 239                 (header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 240                  header.ehdr32.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 241                platform = "mips32-linux";
 242             }
 243          }
 244
 245       } else if (n_bytes >= sizeof(Elf64_Ehdr) && header.c[EI_CLASS] == ELFCLASS64) {
 246
 247          if (header.c[EI_DATA] == ELFDATA2LSB) {
 248 #           if defined(VGO_solaris)
 249             if (header.ehdr64.e_machine == EM_X86_64 &&
 250                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 251                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 252                platform = "amd64-solaris";
 253             }
 254             else
 255 #           endif
 256             if (header.ehdr64.e_machine == EM_X86_64 &&
 257                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 258                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 259                platform = "amd64-linux";
 260             } else if (header.ehdr64.e_machine == EM_MIPS &&
 261                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 262                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 263                platform = "mips64-linux";
 264             } else if (header.ehdr64.e_machine == EM_AARCH64 &&
 265                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 266                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 267                platform = "arm64-linux";
 268             } else if (header.ehdr64.e_machine == EM_PPC64 &&
 269                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 270                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 271                platform = "ppc64le-linux";
 272             }
 273          } else if (header.c[EI_DATA] == ELFDATA2MSB) {
 274 #           if !defined(VGPV_arm_linux_android) \
 275                && !defined(VGPV_x86_linux_android) \
 276                && !defined(VGPV_mips32_linux_android) \
 277                && !defined(VGPV_arm64_linux_android)
 278             if (header.ehdr64.e_machine == EM_PPC64 &&
 279                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 280                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 281                platform = "ppc64be-linux";
 282             }
 283             else
 284             if (header.ehdr64.e_machine == EM_S390 &&
 285                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 286                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 287                platform = "s390x-linux";
 288             } else if (header.ehdr64.e_machine == EM_MIPS &&
 289                 (header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 290                  header.ehdr64.e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 291                platform = "mips64-linux";
 292             }
 293 #           endif
 294          }
 295       }
 296    }
 297
 298    VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
 299                  platform ? platform : "unknown");
 300
 301    return platform;
 302 }
 303
 304 /* Where we expect to find all our aux files */
 305 static const char *valgrind_lib = VG_LIBDIR;
 306
 307 int main(int argc, char** argv, char** envp)
 308 {
 309    int i, j, loglevel, r;
 310    const char *toolname = NULL;
 311    const char *clientname = NULL;
 312    const char *platform;
 313    const char *default_platform;
 314    const char *cp;
 315    const char *linkname;
 316    char *toolfile;
 317    const char *launcher_name;
 318    char* new_line;
 319    char** new_env;
 320
 321    /* Start the debugging-log system ASAP.  First find out how many
 322       "-d"s were specified.  This is a pre-scan of the command line.
 323       At the same time, look for the tool name. */
 324    loglevel = 0;
 325    for (i = 1; i < argc; i++) {
 326       if (argv[i][0] != '-') {
 327          clientname = argv[i];
 328          break;
 329       }
 330       if (0 == strcmp(argv[i], "--")) {
 331          if (i+1 < argc)
 332             clientname = argv[i+1];
 333          break;
 334       }
 335       if (0 == strcmp(argv[i], "-d"))
 336          loglevel++;
 337       if (0 == strncmp(argv[i], "--tool=", 7))
 338          toolname = argv[i] + 7;
 339    }
 340
 341    /* ... and start the debug logger.  Now we can safely emit logging
 342       messages all through startup. */
 343    VG_(debugLog_startup)(loglevel, "Stage 1");
 344
 345    /* Make sure we know which tool we're using */
 346    if (toolname) {
 347       VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
 348    } else {
 349       VG_(debugLog)(1, "launcher",
 350                        "no tool requested, defaulting to 'memcheck'\n");
 351       toolname = "memcheck";
 352    }
 353
 354    /* Select a platform to use if we can't decide that by looking at
 355       the executable (eg because it's a shell script).  VG_PLATFORM is the
 356       default_platform. Its value is defined in coregrind/Makefile.am and
 357       typically it is the primary build target. Unless the primary build
 358       target is not built is not built in which case VG_PLATFORM is the
 359       secondary build target. */
 360 #  if defined(VGO_linux)
 361    if ((0==strcmp(VG_PLATFORM,"x86-linux"))    ||
 362        (0==strcmp(VG_PLATFORM,"amd64-linux"))  ||
 363        (0==strcmp(VG_PLATFORM,"ppc32-linux"))  ||
 364        (0==strcmp(VG_PLATFORM,"ppc64be-linux"))  ||
 365        (0==strcmp(VG_PLATFORM,"ppc64le-linux"))  ||
 366        (0==strcmp(VG_PLATFORM,"arm-linux"))    ||
 367        (0==strcmp(VG_PLATFORM,"arm64-linux"))  ||
 368        (0==strcmp(VG_PLATFORM,"s390x-linux"))  ||
 369        (0==strcmp(VG_PLATFORM,"mips32-linux")) ||
 370        (0==strcmp(VG_PLATFORM,"mips64-linux")))
 371       default_platform = VG_PLATFORM;
 372 #  elif defined(VGO_solaris)
 373    if ((0==strcmp(VG_PLATFORM,"x86-solaris")) ||
 374        (0==strcmp(VG_PLATFORM,"amd64-solaris")))
 375       default_platform = SOLARIS_LAUNCHER_DEFAULT_PLATFORM;
 376 #  else
 377 #    error Unknown OS
 378 #  endif
 379    else
 380       barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
 381
 382    /* Work out what platform to use, or use the default platform if
 383       not possible. */
 384    if (clientname == NULL) {
 385       VG_(debugLog)(1, "launcher",
 386                        "no client specified, defaulting platform to '%s'\n",
 387                         default_platform);
 388       platform = default_platform;
 389    } else if ((platform = select_platform(clientname)) != NULL) {
 390       VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
 391    } else {
 392       VG_(debugLog)(1, "launcher",
 393                        "no platform detected, defaulting platform to '%s'\n",
 394                        default_platform);
 395       platform = default_platform;
 396    }
 397
 398    /* Figure out the name of this executable (viz, the launcher), so
 399       we can tell stage2.  stage2 will use the name for recursive
 400       invocations of valgrind on child processes. */
 401 #  if defined(VGO_linux)
 402    linkname = "/proc/self/exe";
 403 #  elif defined(VGO_solaris)
 404    linkname = "/proc/self/path/a.out";
 405 #  else
 406 #    error Unknown OS
 407 #  endif
 408    unsigned bufsiz = 0;
 409    char *buf = NULL;
 410
 411    while (42) {
 412       bufsiz += 500;
 413       buf = realloc(buf, bufsiz);
 414       if (buf == NULL)
 415          barf("realloc of buf failed.");
 416       r = readlink(linkname, buf, bufsiz);
 417       if (r == -1) {
 418         /* If /proc/self/exe (/proc/self/path/a.out) can't be followed, don't
 419            give up. Instead continue with an empty string for VALGRIND_LAUNCHER.
 420            In the sys_execve wrapper, this is tested, and if found to be empty,
 421            fail the execve. */
 422         fprintf(stderr, "valgrind: warning (non-fatal): "
 423                 "readlink(\"%s\") failed.\n", linkname);
 424         fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
 425                 "will not work.\n");
 426         launcher_name = "";
 427         break;
 428       }
 429       if (r == bufsiz) continue;   // buffer to small; retry
 430
 431       assert(r < bufsiz);   // paranoia
 432
 433       buf[r] = '\0';
 434       launcher_name = buf;
 435       break;
 436    }
 437
 438    /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
 439    new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
 440                      + strlen(launcher_name) + 1);
 441    if (new_line == NULL)
 442       barf("malloc of new_line failed.");
 443    strcpy(new_line, VALGRIND_LAUNCHER);
 444    strcat(new_line, "=");
 445    strcat(new_line, launcher_name);
 446
 447    for (j = 0; envp[j]; j++)
 448       ;
 449    new_env = malloc((j+2) * sizeof(char*));
 450    if (new_env == NULL)
 451       barf("malloc of new_env failed.");
 452    for (i = 0; i < j; i++)
 453       new_env[i] = envp[i];
 454    new_env[i++] = new_line;
 455    new_env[i++] = NULL;
 456    assert(i == j+2);
 457
 458    /* Establish the correct VALGRIND_LIB. */
 459    cp = getenv(VALGRIND_LIB);
 460
 461    if (cp != NULL)
 462       valgrind_lib = cp;
 463
 464    /* Build the stage2 invocation, and execve it.  Bye! */
 465    toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
 466    if (toolfile == NULL)
 467       barf("malloc of toolfile failed.");
 468    sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
 469
 470    VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
 471
 472    execve(toolfile, argv, new_env);
 473
 474    fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
 475                    toolname, platform, strerror(errno));
 476
 477    exit(1);
 478 }