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) 2000-2015 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 #ifndef EM_TILEGX
  69 #define EM_TILEGX 191
  70 #endif
  71
  72 /* Report fatal errors */
  73 __attribute__((noreturn))
  74 static void barf ( const char *format, ... )
  75 {
  76    va_list vargs;
  77
  78    va_start(vargs, format);
  79    fprintf(stderr, "valgrind: Cannot continue: ");
  80    vfprintf(stderr, format, vargs);
  81    fprintf(stderr, "\n");
  82    va_end(vargs);
  83
  84    exit(1);
  85    /*NOTREACHED*/
  86    assert(0);
  87 }
  88
  89 /* Search the path for the client program */
  90 static const char *find_client(const char *clientname)
  91 {
  92    char *fullname;
  93    const char *path = getenv("PATH");
  94    const char *colon;
  95
  96    assert(clientname != NULL);
  97
  98    if (path == NULL) return clientname;
  99
 100    /* Make the size of the FULLNAME buffer large enough. */
 101    unsigned need = strlen(path) + strlen("/") + strlen(clientname) + 1;
 102
 103    fullname = malloc(need);
 104    if (fullname == NULL)
 105       barf("malloc of fullname failed.");
 106
 107    while (path)
 108    {
 109       if ((colon = strchr(path, ':')) == NULL)
 110       {
 111          strcpy(fullname, path);
 112          path = NULL;
 113       }
 114       else
 115       {
 116          strncpy(fullname, path, colon - path);
 117          fullname[colon - path] = '\0';
 118          path = colon + 1;
 119       }
 120
 121       strcat(fullname, "/");
 122       strcat(fullname, clientname);
 123
 124       if (access(fullname, R_OK|X_OK) == 0)
 125          return fullname;
 126    }
 127    free(fullname);
 128
 129    return clientname;
 130 }
 131
 132 /* Examine the client and work out which platform it is for */
 133 static const char *select_platform(const char *clientname)
 134 {
 135    int fd;
 136    char header[4096];
 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, 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[0] == '#' && header[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[n_bytes] = '\0';
 169       char *eol = strchr(header, '\n');
 170       if (eol != NULL)
 171          *eol = '\0';
 172
 173       // Skip whitespace.
 174       while  (header[i] == ' '|| header[i] == '\t')
 175          i++;
 176
 177       // Get the interpreter name.
 178       const char *interp = header + i;
 179
 180       if (header[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[i]) {
 192             if (header[i] == ' ' || header[i] == '\t') break;
 193             i++;
 194          }
 195          header[i] = '\0';
 196       }
 197
 198       platform = select_platform(interp);
 199
 200    } else if (n_bytes >= SELFMAG && memcmp(header, ELFMAG, SELFMAG) == 0) {
 201
 202       if (n_bytes >= sizeof(Elf32_Ehdr) && header[EI_CLASS] == ELFCLASS32) {
 203          const Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header;
 204
 205          if (header[EI_DATA] == ELFDATA2LSB) {
 206 #           if defined(VGO_solaris)
 207             if (ehdr->e_machine == EM_386 &&
 208                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 209                  ehdr->e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 210                platform = "x86-solaris";
 211             }
 212             else
 213 #           endif
 214             if (ehdr->e_machine == EM_386 &&
 215                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 216                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 217                platform = "x86-linux";
 218             }
 219             else
 220             if (ehdr->e_machine == EM_ARM &&
 221                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 222                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 223                platform = "arm-linux";
 224             }
 225             else
 226             if (ehdr->e_machine == EM_MIPS &&
 227                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 228                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 229                platform = "mips32-linux";
 230             }
 231          }
 232          else if (header[EI_DATA] == ELFDATA2MSB) {
 233             if (ehdr->e_machine == EM_PPC &&
 234                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 235                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 236                platform = "ppc32-linux";
 237             }
 238             else
 239             if (ehdr->e_machine == EM_MIPS &&
 240                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 241                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 242                platform = "mips32-linux";
 243             }
 244          }
 245
 246       } else if (n_bytes >= sizeof(Elf64_Ehdr) && header[EI_CLASS] == ELFCLASS64) {
 247          const Elf64_Ehdr *ehdr = (Elf64_Ehdr *)header;
 248
 249          if (header[EI_DATA] == ELFDATA2LSB) {
 250 #           if defined(VGO_solaris)
 251             if (ehdr->e_machine == EM_X86_64 &&
 252                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 253                  ehdr->e_ident[EI_OSABI] == ELFOSABI_SOLARIS)) {
 254                platform = "amd64-solaris";
 255             }
 256             else
 257 #           endif
 258             if (ehdr->e_machine == EM_X86_64 &&
 259                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 260                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 261                platform = "amd64-linux";
 262             } else if (ehdr->e_machine == EM_MIPS &&
 263                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 264                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 265                platform = "mips64-linux";
 266             } else if (ehdr->e_machine == EM_TILEGX &&
 267                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 268                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 269                platform = "tilegx-linux";
 270             } else if (ehdr->e_machine == EM_AARCH64 &&
 271                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 272                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 273                platform = "arm64-linux";
 274             } else if (ehdr->e_machine == EM_PPC64 &&
 275                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 276                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 277                platform = "ppc64le-linux";
 278             }
 279          } else if (header[EI_DATA] == ELFDATA2MSB) {
 280 #           if !defined(VGPV_arm_linux_android) \
 281                && !defined(VGPV_x86_linux_android) \
 282                && !defined(VGPV_mips32_linux_android) \
 283                && !defined(VGPV_arm64_linux_android)
 284             if (ehdr->e_machine == EM_PPC64 &&
 285                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 286                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 287                platform = "ppc64be-linux";
 288             }
 289             else
 290             if (ehdr->e_machine == EM_S390 &&
 291                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 292                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 293                platform = "s390x-linux";
 294             } else if (ehdr->e_machine == EM_MIPS &&
 295                 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
 296                  ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
 297                platform = "mips64-linux";
 298             }
 299 #           endif
 300          }
 301       }
 302    }
 303
 304    VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
 305                  platform ? platform : "unknown");
 306
 307    return platform;
 308 }
 309
 310 /* Where we expect to find all our aux files */
 311 static const char *valgrind_lib = VG_LIBDIR;
 312
 313 int main(int argc, char** argv, char** envp)
 314 {
 315    int i, j, loglevel, r;
 316    const char *toolname = NULL;
 317    const char *clientname = NULL;
 318    const char *platform;
 319    const char *default_platform;
 320    const char *cp;
 321    const char *linkname;
 322    char *toolfile;
 323    const char *launcher_name;
 324    char* new_line;
 325    char** new_env;
 326
 327    /* Start the debugging-log system ASAP.  First find out how many
 328       "-d"s were specified.  This is a pre-scan of the command line.
 329       At the same time, look for the tool name. */
 330    loglevel = 0;
 331    for (i = 1; i < argc; i++) {
 332       if (argv[i][0] != '-') {
 333          clientname = argv[i];
 334          break;
 335       }
 336       if (0 == strcmp(argv[i], "--")) {
 337          if (i+1 < argc)
 338             clientname = argv[i+1];
 339          break;
 340       }
 341       if (0 == strcmp(argv[i], "-d"))
 342          loglevel++;
 343       if (0 == strncmp(argv[i], "--tool=", 7))
 344          toolname = argv[i] + 7;
 345    }
 346
 347    /* ... and start the debug logger.  Now we can safely emit logging
 348       messages all through startup. */
 349    VG_(debugLog_startup)(loglevel, "Stage 1");
 350
 351    /* Make sure we know which tool we're using */
 352    if (toolname) {
 353       VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
 354    } else {
 355       VG_(debugLog)(1, "launcher",
 356                        "no tool requested, defaulting to 'memcheck'\n");
 357       toolname = "memcheck";
 358    }
 359
 360    /* Select a platform to use if we can't decide that by looking at
 361       the executable (eg because it's a shell script).  VG_PLATFORM is the
 362       default_platform. Its value is defined in coregrind/Makefile.am and
 363       typically it is the primary build target. Unless the primary build
 364       target is not built is not built in which case VG_PLATFORM is the
 365       secondary build target. */
 366 #  if defined(VGO_linux)
 367    if ((0==strcmp(VG_PLATFORM,"x86-linux"))    ||
 368        (0==strcmp(VG_PLATFORM,"amd64-linux"))  ||
 369        (0==strcmp(VG_PLATFORM,"ppc32-linux"))  ||
 370        (0==strcmp(VG_PLATFORM,"ppc64be-linux"))  ||
 371        (0==strcmp(VG_PLATFORM,"ppc64le-linux"))  ||
 372        (0==strcmp(VG_PLATFORM,"arm-linux"))    ||
 373        (0==strcmp(VG_PLATFORM,"arm64-linux"))  ||
 374        (0==strcmp(VG_PLATFORM,"s390x-linux"))  ||
 375        (0==strcmp(VG_PLATFORM,"tilegx-linux")) ||
 376        (0==strcmp(VG_PLATFORM,"mips32-linux")) ||
 377        (0==strcmp(VG_PLATFORM,"mips64-linux")))
 378       default_platform = VG_PLATFORM;
 379 #  elif defined(VGO_solaris)
 380    if ((0==strcmp(VG_PLATFORM,"x86-solaris")) ||
 381        (0==strcmp(VG_PLATFORM,"amd64-solaris")))
 382       default_platform = SOLARIS_LAUNCHER_DEFAULT_PLATFORM;
 383 #  else
 384 #    error Unknown OS
 385 #  endif
 386    else
 387       barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
 388
 389    /* Work out what platform to use, or use the default platform if
 390       not possible. */
 391    if (clientname == NULL) {
 392       VG_(debugLog)(1, "launcher",
 393                        "no client specified, defaulting platform to '%s'\n",
 394                         default_platform);
 395       platform = default_platform;
 396    } else if ((platform = select_platform(clientname)) != NULL) {
 397       VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
 398    } else {
 399       VG_(debugLog)(1, "launcher",
 400                        "no platform detected, defaulting platform to '%s'\n",
 401                        default_platform);
 402       platform = default_platform;
 403    }
 404
 405    /* Figure out the name of this executable (viz, the launcher), so
 406       we can tell stage2.  stage2 will use the name for recursive
 407       invocations of valgrind on child processes. */
 408 #  if defined(VGO_linux)
 409    linkname = "/proc/self/exe";
 410 #  elif defined(VGO_solaris)
 411    linkname = "/proc/self/path/a.out";
 412 #  else
 413 #    error Unknown OS
 414 #  endif
 415    unsigned bufsiz = 0;
 416    char *buf = NULL;
 417
 418    while (42) {
 419       bufsiz += 500;
 420       buf = realloc(buf, bufsiz);
 421       if (buf == NULL)
 422          barf("realloc of buf failed.");
 423       r = readlink(linkname, buf, bufsiz);
 424       if (r == -1) {
 425         /* If /proc/self/exe (/proc/self/path/a.out) can't be followed, don't
 426            give up. Instead continue with an empty string for VALGRIND_LAUNCHER.
 427            In the sys_execve wrapper, this is tested, and if found to be empty,
 428            fail the execve. */
 429         fprintf(stderr, "valgrind: warning (non-fatal): "
 430                 "readlink(\"%s\") failed.\n", linkname);
 431         fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
 432                 "will not work.\n");
 433         launcher_name = "";
 434         break;
 435       }
 436       if (r == bufsiz) continue;   // buffer to small; retry
 437
 438       assert(r < bufsiz);   // paranoia
 439
 440       buf[r] = '\0';
 441       launcher_name = buf;
 442       break;
 443    }
 444
 445    /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
 446    new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
 447                      + strlen(launcher_name) + 1);
 448    if (new_line == NULL)
 449       barf("malloc of new_line failed.");
 450    strcpy(new_line, VALGRIND_LAUNCHER);
 451    strcat(new_line, "=");
 452    strcat(new_line, launcher_name);
 453
 454    for (j = 0; envp[j]; j++)
 455       ;
 456    new_env = malloc((j+2) * sizeof(char*));
 457    if (new_env == NULL)
 458       barf("malloc of new_env failed.");
 459    for (i = 0; i < j; i++)
 460       new_env[i] = envp[i];
 461    new_env[i++] = new_line;
 462    new_env[i++] = NULL;
 463    assert(i == j+2);
 464
 465    /* Establish the correct VALGRIND_LIB. */
 466    cp = getenv(VALGRIND_LIB);
 467
 468    if (cp != NULL)
 469       valgrind_lib = cp;
 470
 471    /* Build the stage2 invocation, and execve it.  Bye! */
 472    toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
 473    if (toolfile == NULL)
 474       barf("malloc of toolfile failed.");
 475    sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
 476
 477    VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
 478
 479    execve(toolfile, argv, new_env);
 480
 481    fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
 482                    toolname, platform, strerror(errno));
 483
 484    exit(1);
 485 }