coregrind/launcher-freebsd.c

   1
   2 /*--------------------------------------------------------------------*/
   3 /*--- Launching valgrind                              m_launcher.c ---*/
   4 /*--------------------------------------------------------------------*/
   5
   6 /*
   7    This file is part of Valgrind, a dynamic binary instrumentation
   8    framework.
   9
  10    Copyright (C) 2000-2009 Julian Seward
  11       jseward@acm.org
  12    Copyright (C) 2018-2021 Paul Floyd
  13       pjfloyd@wanadoo.fr
  14
  15    This program is free software; you can redistribute it and/or
  16    modify it under the terms of the GNU General Public License as
  17    published by the Free Software Foundation; either version 2 of the
  18    License, or (at your option) any later version.
  19
  20    This program is distributed in the hope that it will be useful, but
  21    WITHOUT ANY WARRANTY; without even the implied warranty of
  22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23    General Public License for more details.
  24
  25    You should have received a copy of the GNU General Public License
  26    along with this program; if not, see <http://www.gnu.org/licenses/>.
  27
  28    The GNU General Public License is contained in the file COPYING.
  29 */
  30
  31 /* Note: this is a "normal" program and not part of Valgrind proper,
  32    and so it doesn't have to conform to Valgrind's arcane rules on
  33    no-glibc-usage etc. */
  34
  35 #include <assert.h>
  36 #include <ctype.h>
  37 #include <elf.h>
  38 #include <errno.h>
  39 #include <fcntl.h>
  40 #include <stdarg.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <sys/mman.h>
  45 #include <sys/sysctl.h>
  46 /* #include <sys/user.h> */
  47 #include <unistd.h>
  48
  49 #include "pub_core_debuglog.h"
  50 #include "pub_core_vki.h"       // Avoids warnings from
  51 // pub_core_libcfile.h
  52 #include "pub_core_libcproc.h"  // For VALGRIND_LIB, VALGRIND_LAUNCHER
  53 #include "pub_core_ume.h"
  54
  55
  56 #if !defined(PATH_MAX)
  57 #define PATH_MAX 4096 /* POSIX refers to this a lot but I dunno
  58                          where it is defined */
  59 #endif
  60
  61 #ifndef EM_X86_64
  62 #define EM_X86_64 62    // elf.h doesn't define this on some older systems
  63 #endif
  64
  65 /* Report fatal errors */
  66 __attribute__((noreturn))
  67 static void barf ( const char *format, ... )
  68 {
  69    va_list vargs;
  70
  71    va_start(vargs, format);
  72    fprintf(stderr, "valgrind: Cannot continue: ");
  73    vfprintf(stderr, format, vargs);
  74    fprintf(stderr, "\n");
  75    va_end(vargs);
  76
  77    exit(1);
  78    /*NOTREACHED*/
  79    assert(0);
  80 }
  81
  82 /* Search the path for the client program */
  83 static const char *find_client(const char *clientname)
  84 {
  85    static char fullname[PATH_MAX];
  86    const char *path = getenv("PATH");
  87    const char *colon;
  88
  89    while (path) {
  90       if ((colon = strchr(path, ':')) == NULL) {
  91          strcpy(fullname, path);
  92          path = NULL;
  93       } else {
  94          memcpy(fullname, path, colon - path);
  95          fullname[colon - path] = '\0';
  96          path = colon + 1;
  97       }
  98
  99       strcat(fullname, "/");
 100       strcat(fullname, clientname);
 101
 102       if (access(fullname, R_OK|X_OK) == 0)
 103          return fullname;
 104    }
 105
 106    return clientname;
 107 }
 108
 109 /* Examine the client and work out which platform it is for */
 110 static const char *select_platform(const char *clientname)
 111 {
 112    int fd;
 113    char header[4096];
 114    ssize_t n_bytes;
 115    const char *platform = NULL;
 116
 117    VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
 118
 119    if (strchr(clientname, '/') == NULL)
 120       clientname = find_client(clientname);
 121
 122    if ((fd = open(clientname, O_RDONLY)) < 0)
 123       return NULL;
 124    //   barf("open(%s): %s", clientname, strerror(errno));
 125
 126    n_bytes = read(fd, header, sizeof(header));
 127    close(fd);
 128    if (n_bytes < 2) {
 129       return NULL;
 130    }
 131
 132    if (header[0] == '#' && header[1] == '!') {
 133       int i = 2;
 134       char *interp = (char *)header + 2;
 135
 136       // Skip whitespace.
 137       while (1) {
 138          if (i == n_bytes) return NULL;
 139          if (' ' != header[i] && '\t' == header[i]) break;
 140          i++;
 141       }
 142
 143       // Get the interpreter name.
 144       interp = &header[i];
 145       while (1) {
 146          if (i == n_bytes) break;
 147          if (isspace(header[i])) break;
 148          i++;
 149       }
 150       if (i == n_bytes) return NULL;
 151       header[i] = '\0';
 152
 153       platform = select_platform(interp);
 154
 155    } else if (n_bytes >= SELFMAG && memcmp(header, ELFMAG, SELFMAG) == 0) {
 156
 157       if ((size_t)n_bytes >= sizeof(Elf32_Ehdr) && header[EI_CLASS] == ELFCLASS32) {
 158          const Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header;
 159
 160          if (header[EI_DATA] == ELFDATA2LSB) {
 161             if (ehdr->e_machine == EM_386 &&
 162                   ehdr->e_ident[EI_OSABI] == ELFOSABI_FREEBSD) {
 163                platform = "x86-freebsd";
 164             }
 165          }
 166       } else if ((size_t)n_bytes >= sizeof(Elf64_Ehdr) && header[EI_CLASS] == ELFCLASS64) {
 167          const Elf64_Ehdr *ehdr = (Elf64_Ehdr *)header;
 168
 169          if (header[EI_DATA] == ELFDATA2LSB) {
 170             if (ehdr->e_machine == EM_X86_64 &&
 171                   ehdr->e_ident[EI_OSABI] == ELFOSABI_FREEBSD) {
 172                platform = "amd64-freebsd";
 173             }
 174          }
 175       }
 176    }
 177
 178    VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
 179                  platform ? platform : "unknown");
 180
 181    return platform;
 182 }
 183
 184 /* Where we expect to find all our aux files */
 185 static const char *valgrind_lib = VG_LIBDIR;
 186
 187 int main(int argc, char** argv, char** envp)
 188 {
 189    int i, j, loglevel, r;
 190    const char *toolname = NULL;
 191    const char *clientname = NULL;
 192    const char *platform;
 193    const char *default_platform;
 194    const char *cp;
 195    char *toolfile;
 196    char launcher_name[PATH_MAX+1];
 197    char* new_line;
 198    char** new_env;
 199    int oid[4];
 200    vki_size_t len;
 201
 202    /* Start the debugging-log system ASAP.  First find out how many
 203       "-d"s were specified.  This is a pre-scan of the command line.
 204       At the same time, look for the tool name. */
 205    loglevel = 0;
 206    for (i = 1; i < argc; i++) {
 207       if (argv[i][0] != '-') {
 208          clientname = argv[i];
 209          break;
 210       }
 211       if (0 == strcmp(argv[i], "--")) {
 212          if (i+1 < argc)
 213             clientname = argv[i+1];
 214          break;
 215       }
 216       if (0 == strcmp(argv[i], "-d"))
 217          loglevel++;
 218       if (0 == strncmp(argv[i], "--tool=", 7))
 219          toolname = argv[i] + 7;
 220    }
 221
 222    /* ... and start the debug logger.  Now we can safely emit logging
 223       messages all through startup. */
 224    VG_(debugLog_startup)(loglevel, "Stage 1");
 225
 226    /* Make sure we know which tool we're using */
 227    if (toolname) {
 228       VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
 229    } else {
 230       VG_(debugLog)(1, "launcher",
 231                     "no tool requested, defaulting to 'memcheck'\n");
 232       toolname = "memcheck";
 233    }
 234
 235    /* Select a platform to use if we can't decide that by looking at
 236       the executable (eg because it's a shell script).  Note that the
 237       default_platform is not necessarily either the primary or
 238       secondary build target.  Instead it's chosen to maximise the
 239       chances that /bin/sh will work on it.  Hence for a primary
 240       target of ppc64-linux we still choose ppc32-linux as the default
 241       target, because on most ppc64-linux setups, the basic /bin,
 242       /usr/bin, etc, stuff is built in 32-bit mode, not 64-bit
 243       mode. */
 244    if (0==strcmp(VG_PLATFORM,"x86-freebsd"))
 245       default_platform = "x86-freebsd";
 246    else if (0==strcmp(VG_PLATFORM,"amd64-freebsd"))
 247       default_platform = "amd64-freebsd";
 248    else
 249       barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
 250
 251    /* Work out what platform to use, or use the default platform if
 252       not possible. */
 253    if (clientname == NULL) {
 254       VG_(debugLog)(1, "launcher",
 255                     "no client specified, defaulting platform to '%s'\n",
 256                     default_platform);
 257       platform = default_platform;
 258    } else if ((platform = select_platform(clientname)) != NULL) {
 259       VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
 260    } else {
 261       VG_(debugLog)(1, "launcher",
 262                     "no platform detected, defaulting platform to '%s'\n",
 263                     default_platform);
 264       platform = default_platform;
 265    }
 266
 267    /* Figure out the name of this executable (viz, the launcher), so
 268       we can tell stage2.  stage2 will use the name for recursive
 269       invocations of valgrind on child processes. */
 270    memset(launcher_name, 0, PATH_MAX+1);
 271
 272    oid[0] = CTL_KERN;
 273    oid[1] = KERN_PROC;
 274    oid[2] = KERN_PROC_PATHNAME;
 275    oid[3] = getpid();
 276    len = PATH_MAX;
 277    r = sysctl(oid, 4, launcher_name, &len, 0, 0);
 278    if (r != 0) {
 279       fprintf(stderr, "valgrind: warning (non-fatal): "
 280               "sysctl(\"kern.proc.pathname\") failed.\n");
 281       fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
 282               "will not work.\n");
 283    }
 284
 285    /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
 286    new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
 287                      + strlen(launcher_name) + 1);
 288    if (new_line == NULL)
 289       barf("malloc of new_line failed.");
 290    strcpy(new_line, VALGRIND_LAUNCHER);
 291    strcat(new_line, "=");
 292    strcat(new_line, launcher_name);
 293
 294    for (j = 0; envp[j]; j++)
 295       ;
 296    new_env = malloc((j+2) * sizeof(char*));
 297    if (new_env == NULL)
 298       barf("malloc of new_env failed.");
 299    for (i = 0; i < j; i++)
 300       new_env[i] = envp[i];
 301    new_env[i++] = new_line;
 302    new_env[i++] = NULL;
 303    assert(i == j+2);
 304
 305    /* Establish the correct VALGRIND_LIB. */
 306    cp = getenv(VALGRIND_LIB);
 307
 308    if (cp != NULL)
 309       valgrind_lib = cp;
 310
 311    /* Build the stage2 invocation, and execve it.  Bye! */
 312    toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
 313    if (toolfile == NULL)
 314       barf("malloc of toolfile failed.");
 315    sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
 316
 317    VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
 318
 319    execve(toolfile, argv, new_env);
 320
 321    fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
 322            toolname, platform, strerror(errno));
 323
 324    exit(1);
 325 }