src/mc/mc_process.c

   1 #include <assert.h>
   2 #include <stddef.h>
   3 #include <stdbool.h>
   4 #include <stdint.h>
   5 #include <errno.h>
   6
   7 #include <sys/types.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <regex.h>
  11 #include <sys/mman.h> // PROT_*
  12
  13 #include <pthread.h>
  14
  15 #include <libgen.h>
  16
  17 #include <libunwind.h>
  18 #include <libunwind-ptrace.h>
  19
  20 #include <xbt/mmalloc.h>
  21
  22 #include "mc_process.h"
  23 #include "mc_object_info.h"
  24 #include "mc_address_space.h"
  25 #include "mc_unw.h"
  26 #include "mc_snapshot.h"
  27 #include "mc_ignore.h"
  28 #include "mc_smx.h"
  29
  30 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc,
  31                                 "MC process information");
  32
  33 static void MC_process_init_memory_map_info(mc_process_t process);
  34 static void MC_process_open_memory_file(mc_process_t process);
  35
  36 // ***** Destructor callbacks
  37
  38 // ***** mc_address_space methods for mc_process
  39
  40 static mc_process_t MC_process_get_process(mc_process_t p) {
  41   return p;
  42 }
  43
  44 static const s_mc_address_space_class_t mc_process_class = {
  45   .read = (void*) &MC_process_read,
  46   .get_process = (void*) MC_process_get_process
  47 };
  48
  49 bool MC_is_process(mc_address_space_t p)
  50 {
  51   return p->address_space_class == &mc_process_class;
  52 }
  53
  54 // ***** mc_process
  55
  56 void MC_process_init(mc_process_t process, pid_t pid, int sockfd)
  57 {
  58   process->address_space.address_space_class = &mc_process_class;
  59   process->process_flags = MC_PROCESS_NO_FLAG;
  60   process->socket = sockfd;
  61   process->pid = pid;
  62   if (pid==getpid())
  63     process->process_flags |= MC_PROCESS_SELF_FLAG;
  64   process->running = true;
  65   process->status = 0;
  66   process->memory_map = MC_get_memory_map(pid);
  67   process->memory_file = -1;
  68   process->cache_flags = 0;
  69   process->heap = NULL;
  70   process->heap_info = NULL;
  71   MC_process_init_memory_map_info(process);
  72   MC_process_open_memory_file(process);
  73
  74   // Read std_heap (is a struct mdesc*):
  75   dw_variable_t std_heap_var = MC_process_find_variable_by_name(process, "std_heap");
  76   if (!std_heap_var)
  77     xbt_die("No heap information in the target process");
  78   if(!std_heap_var->address)
  79     xbt_die("No constant address for this variable");
  80   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
  81     &process->heap_address, std_heap_var->address, sizeof(struct mdesc*),
  82     MC_PROCESS_INDEX_DISABLED);
  83
  84   process->smx_process_infos = MC_smx_process_info_list_new();
  85   process->smx_old_process_infos = MC_smx_process_info_list_new();
  86
  87   process->checkpoint_ignore = MC_checkpoint_ignore_new();
  88
  89   process->unw_addr_space = unw_create_addr_space(&mc_unw_accessors  , __BYTE_ORDER);
  90   if (process->process_flags & MC_PROCESS_SELF_FLAG) {
  91     process->unw_underlying_addr_space = unw_local_addr_space;
  92     process->unw_underlying_context = NULL;
  93   } else {
  94     process->unw_underlying_addr_space = unw_create_addr_space(&mc_unw_vmread_accessors, __BYTE_ORDER);
  95     process->unw_underlying_context = _UPT_create(pid);
  96   }
  97 }
  98
  99 void MC_process_clear(mc_process_t process)
 100 {
 101   process->address_space.address_space_class = NULL;
 102   process->process_flags = MC_PROCESS_NO_FLAG;
 103   process->pid = 0;
 104
 105   MC_free_memory_map(process->memory_map);
 106   process->memory_map = NULL;
 107
 108   process->maestro_stack_start = NULL;
 109   process->maestro_stack_end = NULL;
 110
 111   xbt_dynar_free(&process->checkpoint_ignore);
 112
 113   xbt_dynar_free(&process->smx_process_infos);
 114   xbt_dynar_free(&process->smx_old_process_infos);
 115
 116   size_t i;
 117   for (i=0; i!=process->object_infos_size; ++i) {
 118     MC_free_object_info(&process->object_infos[i]);
 119   }
 120   free(process->object_infos);
 121   process->object_infos = NULL;
 122   process->object_infos_size = 0;
 123   if (process->memory_file >= 0) {
 124     close(process->memory_file);
 125   }
 126
 127   if (process->unw_underlying_addr_space != unw_local_addr_space) {
 128     unw_destroy_addr_space(process->unw_underlying_addr_space);
 129     _UPT_destroy(process->unw_underlying_context);
 130   }
 131   process->unw_underlying_context = NULL;
 132   process->unw_underlying_addr_space = NULL;
 133
 134   unw_destroy_addr_space(process->unw_addr_space);
 135   process->unw_addr_space = NULL;
 136
 137   process->cache_flags = 0;
 138
 139   free(process->heap);
 140   process->heap = NULL;
 141
 142   free(process->heap_info);
 143   process->heap_info = NULL;
 144 }
 145
 146 void MC_process_refresh_heap(mc_process_t process)
 147 {
 148   assert(!MC_process_is_self(process));
 149   // Read/dereference/refresh the std_heap pointer:
 150   if (!process->heap) {
 151     xbt_mheap_t oldheap  = mmalloc_set_current_heap(mc_heap);
 152     process->heap = malloc(sizeof(struct mdesc));
 153     mmalloc_set_current_heap(oldheap);
 154   }
 155   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
 156     process->heap, process->heap_address, sizeof(struct mdesc),
 157     MC_PROCESS_INDEX_DISABLED
 158     );
 159 }
 160
 161 void MC_process_refresh_malloc_info(mc_process_t process)
 162 {
 163   assert(!MC_process_is_self(process));
 164   if (!process->cache_flags & MC_PROCESS_CACHE_FLAG_HEAP)
 165     MC_process_refresh_heap(process);
 166   // Refresh process->heapinfo:
 167   size_t malloc_info_bytesize =
 168     (process->heap->heaplimit + 1) * sizeof(malloc_info);
 169
 170   xbt_mheap_t heap  = mmalloc_set_current_heap(mc_heap);
 171   process->heap_info = (malloc_info*) realloc(process->heap_info,
 172     malloc_info_bytesize);
 173   mmalloc_set_current_heap(heap);
 174
 175   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
 176     process->heap_info,
 177     process->heap->heapinfo, malloc_info_bytesize,
 178     MC_PROCESS_INDEX_DISABLED);
 179 }
 180
 181 #define SO_RE "\\.so[\\.0-9]*$"
 182 #define VERSION_RE "-[\\.0-9]*$"
 183
 184 const char* FILTERED_LIBS[] = {
 185   "libstdc++",
 186   "libc++",
 187   "libm",
 188   "libgcc_s",
 189   "libpthread",
 190   "libunwind",
 191   "libunwind-x86_64",
 192   "libunwind-x86",
 193   "libunwind-ptrace",
 194   "libdw",
 195   "libdl",
 196   "librt",
 197   "liblzma",
 198   "libelf",
 199   "libbz2",
 200   "libz",
 201   "libelf",
 202   "libc",
 203   "ld"
 204 };
 205
 206 static bool MC_is_simgrid_lib(const char* libname)
 207 {
 208   return !strcmp(libname, "libsimgrid");
 209 }
 210
 211 static bool MC_is_filtered_lib(const char* libname)
 212 {
 213   const size_t n = sizeof(FILTERED_LIBS) / sizeof(const char*);
 214   size_t i;
 215   for (i=0; i!=n; ++i)
 216     if (strcmp(libname, FILTERED_LIBS[i])==0)
 217       return true;
 218   return false;
 219 }
 220
 221 struct s_mc_memory_map_re {
 222   regex_t so_re;
 223   regex_t version_re;
 224 };
 225
 226 static char* MC_get_lib_name(const char* pathname, struct s_mc_memory_map_re* res) {
 227   const char* map_basename = basename((char*) pathname);
 228
 229   regmatch_t match;
 230   if(regexec(&res->so_re, map_basename, 1, &match, 0))
 231     return NULL;
 232
 233   char* libname = strndup(map_basename, match.rm_so);
 234
 235   // Strip the version suffix:
 236   if(libname && !regexec(&res->version_re, libname, 1, &match, 0)) {
 237     char* temp = libname;
 238     libname = strndup(temp, match.rm_so);
 239     free(temp);
 240   }
 241
 242   return libname;
 243 }
 244
 245 /** @brief Finds the range of the different memory segments and binary paths */
 246 static void MC_process_init_memory_map_info(mc_process_t process)
 247 {
 248   XBT_DEBUG("Get debug information ...");
 249   process->maestro_stack_start = NULL;
 250   process->maestro_stack_end = NULL;
 251   process->object_infos = NULL;
 252   process->object_infos_size = 0;
 253   process->binary_info = NULL;
 254   process->libsimgrid_info = NULL;
 255
 256   struct s_mc_memory_map_re res;
 257
 258   if(regcomp(&res.so_re, SO_RE, 0) || regcomp(&res.version_re, VERSION_RE, 0))
 259     xbt_die(".so regexp did not compile");
 260
 261   memory_map_t maps = process->memory_map;
 262
 263   const char* current_name = NULL;
 264
 265   size_t i = 0;
 266   for (i=0; i < maps->mapsize; i++) {
 267     map_region_t reg = &(maps->regions[i]);
 268     const char* pathname = maps->regions[i].pathname;
 269
 270     // Nothing to do
 271     if (maps->regions[i].pathname == NULL) {
 272       current_name = NULL;
 273       continue;
 274     }
 275
 276     // [stack], [vvar], [vsyscall], [vdso] ...
 277     if (pathname[0] == '[') {
 278       if ((reg->prot & PROT_WRITE) && !memcmp(pathname, "[stack]", 7)) {
 279         process->maestro_stack_start = reg->start_addr;
 280         process->maestro_stack_end = reg->end_addr;
 281       }
 282       current_name = NULL;
 283       continue;
 284     }
 285
 286     if (current_name && strcmp(current_name, pathname)==0)
 287       continue;
 288
 289     current_name = pathname;
 290     if (!(reg->prot & PROT_READ) && (reg->prot & PROT_EXEC))
 291       continue;
 292
 293     const bool is_executable = !i;
 294     char* libname = NULL;
 295     if (!is_executable) {
 296       libname = MC_get_lib_name(pathname, &res);
 297       if(!libname)
 298         continue;
 299       if (MC_is_filtered_lib(libname)) {
 300         free(libname);
 301         continue;
 302       }
 303     }
 304
 305     mc_object_info_t info =
 306       MC_find_object_info(process->memory_map, pathname, is_executable);
 307     process->object_infos = (mc_object_info_t*) realloc(process->object_infos,
 308       (process->object_infos_size+1) * sizeof(mc_object_info_t*));
 309     process->object_infos[process->object_infos_size] = info;
 310     process->object_infos_size++;
 311     if (is_executable)
 312       process->binary_info = info;
 313     else if (libname && MC_is_simgrid_lib(libname))
 314       process->libsimgrid_info = info;
 315     free(libname);
 316   }
 317
 318   regfree(&res.so_re);
 319   regfree(&res.version_re);
 320
 321   // Resolve time (including accress differents objects):
 322   for (i=0; i!=process->object_infos_size; ++i)
 323     MC_post_process_object_info(process, process->object_infos[i]);
 324
 325   xbt_assert(process->maestro_stack_start, "Did not find maestro_stack_start");
 326   xbt_assert(process->maestro_stack_end, "Did not find maestro_stack_end");
 327
 328   XBT_DEBUG("Get debug information done !");
 329 }
 330
 331 mc_object_info_t MC_process_find_object_info(mc_process_t process, const void *addr)
 332 {
 333   size_t i;
 334   for (i = 0; i != process->object_infos_size; ++i) {
 335     if (addr >= (void *) process->object_infos[i]->start
 336         && addr <= (void *) process->object_infos[i]->end) {
 337       return process->object_infos[i];
 338     }
 339   }
 340   return NULL;
 341 }
 342
 343 mc_object_info_t MC_process_find_object_info_exec(mc_process_t process, const void *addr)
 344 {
 345   size_t i;
 346   for (i = 0; i != process->object_infos_size; ++i) {
 347     if (addr >= (void *) process->object_infos[i]->start_exec
 348         && addr <= (void *) process->object_infos[i]->end_exec) {
 349       return process->object_infos[i];
 350     }
 351   }
 352   return NULL;
 353 }
 354
 355 mc_object_info_t MC_process_find_object_info_rw(mc_process_t process, const void *addr)
 356 {
 357   size_t i;
 358   for (i = 0; i != process->object_infos_size; ++i) {
 359     if (addr >= (void *) process->object_infos[i]->start_rw
 360         && addr <= (void *) process->object_infos[i]->end_rw) {
 361       return process->object_infos[i];
 362     }
 363   }
 364   return NULL;
 365 }
 366
 367 // Functions, variables…
 368
 369 dw_frame_t MC_process_find_function(mc_process_t process, const void *ip)
 370 {
 371   mc_object_info_t info = MC_process_find_object_info_exec(process, ip);
 372   if (info == NULL)
 373     return NULL;
 374   else
 375     return MC_file_object_info_find_function(info, ip);
 376 }
 377
 378 dw_variable_t MC_process_find_variable_by_name(mc_process_t process, const char* name)
 379 {
 380   const size_t n = process->object_infos_size;
 381   size_t i;
 382
 383   // First lookup the variable in the executable shared object.
 384   // A global variable used directly by the executable code from a library
 385   // is reinstanciated in the executable memory .data/.bss.
 386   // We need to look up the variable in the execvutable first.
 387   if (process->binary_info) {
 388     mc_object_info_t info = process->binary_info;
 389     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
 390     if (var)
 391       return var;
 392   }
 393
 394   for (i=0; i!=n; ++i) {
 395     mc_object_info_t info =process->object_infos[i];
 396     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
 397     if (var)
 398       return var;
 399   }
 400
 401   return NULL;
 402 }
 403
 404 void MC_process_read_variable(mc_process_t process, const char* name, void* target, size_t size)
 405 {
 406   dw_variable_t var = MC_process_find_variable_by_name(process, name);
 407   if (!var->address)
 408     xbt_die("No simple location for this variable");
 409   if (!var->type->full_type)
 410     xbt_die("Partial type for %s, cannot check size", name);
 411   if (var->type->full_type->byte_size != size)
 412     xbt_die("Unexpected size for %s (expected %zi, was %zi)",
 413       name, size, (size_t) var->type->full_type->byte_size);
 414   MC_process_read(process, MC_PROCESS_NO_FLAG, target, var->address, size,
 415     MC_PROCESS_INDEX_ANY);
 416 }
 417
 418 char* MC_process_read_string(mc_process_t process, void* address)
 419 {
 420   if (!address)
 421     return NULL;
 422   if (MC_process_is_self(process))
 423     return strdup((char*) address);
 424
 425   size_t len = 128;
 426   char* res = malloc(len);
 427   off_t off = 0;
 428
 429   while (1) {
 430     ssize_t c = pread(process->memory_file, res + off, len - off, (off_t) address + off);
 431     if (c == -1) {
 432       if (errno == EINTR)
 433         continue;
 434       else
 435         xbt_die("Could not read from from remote process");
 436     }
 437     if (c==0)
 438       xbt_die("Could not read string from remote process");
 439
 440     void* p = memchr(res + off, '\0', c);
 441     if (p)
 442       return res;
 443
 444     off += c;
 445     if (off == len) {
 446       len *= 2;
 447       res = realloc(res, len);
 448     }
 449   }
 450 }
 451
 452 // ***** Memory access
 453
 454 int MC_process_vm_open(pid_t pid, int flags)
 455 {
 456   const size_t buffer_size = 30;
 457   char buffer[buffer_size];
 458   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long) pid);
 459   if (res < 0 || res >= buffer_size) {
 460     errno = ENAMETOOLONG;
 461     return -1;
 462   }
 463   return open(buffer, flags);
 464 }
 465
 466 static void MC_process_open_memory_file(mc_process_t process)
 467 {
 468   if (MC_process_is_self(process) || process->memory_file >= 0)
 469     return;
 470
 471   int fd = MC_process_vm_open(process->pid, O_RDWR);
 472   if (fd<0)
 473     xbt_die("Could not open file for process virtual address space");
 474   process->memory_file = fd;
 475 }
 476
 477 static ssize_t pread_whole(int fd, void *buf, size_t count, off_t offset)
 478 {
 479   char* buffer = (char*) buf;
 480   ssize_t real_count = count;
 481   while (count) {
 482     ssize_t res = pread(fd, buffer, count, offset);
 483     if (res > 0) {
 484       count  -= res;
 485       buffer += res;
 486       offset += res;
 487     } else if (res==0) {
 488       return -1;
 489     } else if (errno != EINTR) {
 490       return -1;
 491     }
 492   }
 493   return real_count;
 494 }
 495
 496 static ssize_t pwrite_whole(int fd, const void *buf, size_t count, off_t offset)
 497 {
 498   const char* buffer = (const char*) buf;
 499   ssize_t real_count = count;
 500   while (count) {
 501     ssize_t res = pwrite(fd, buffer, count, offset);
 502     if (res > 0) {
 503       count  -= res;
 504       buffer += res;
 505       offset += res;
 506     } else if (res==0) {
 507       return -1;
 508     } else if (errno != EINTR) {
 509       return -1;
 510     }
 511   }
 512   return real_count;
 513 }
 514
 515 const void* MC_process_read(mc_process_t process, e_adress_space_read_flags_t flags,
 516   void* local, const void* remote, size_t len,
 517   int process_index)
 518 {
 519   if (process_index != MC_PROCESS_INDEX_DISABLED) {
 520     mc_object_info_t info = MC_process_find_object_info_rw(process, remote);
 521     // Segment overlap is not handled.
 522     if (MC_object_info_is_privatized(info)) {
 523       if (process_index < 0)
 524         xbt_die("Missing process index");
 525       // Address translation in the privaization segment:
 526       size_t offset = (const char*) remote - info->start_rw;
 527       remote = (const char*) remote - offset;
 528     }
 529   }
 530
 531   if (MC_process_is_self(process)) {
 532     if (flags & MC_ADDRESS_SPACE_READ_FLAGS_LAZY)
 533       return remote;
 534     else {
 535       memcpy(local, remote, len);
 536       return local;
 537     }
 538   } else {
 539     if (pread_whole(process->memory_file, local, len, (off_t) remote) < 0)
 540       xbt_die("Read from process %lli failed", (long long) process->pid);
 541     return local;
 542   }
 543 }
 544
 545 const void* MC_process_read_simple(mc_process_t process,
 546   void* local, const void* remote, size_t len)
 547 {
 548   e_adress_space_read_flags_t flags = MC_PROCESS_NO_FLAG;
 549   int index = MC_PROCESS_INDEX_ANY;
 550    MC_process_read(process, flags, local, remote, len, index);
 551    return local;
 552 }
 553
 554 const void* MC_process_read_dynar_element(mc_process_t process,
 555   void* local, const void* remote_dynar, size_t i, size_t len)
 556 {
 557   s_xbt_dynar_t d;
 558   MC_process_read_simple(process, &d, remote_dynar, sizeof(d));
 559   if (i >= d.used)
 560     xbt_die("Out of bound index %zi/%zi", i, d.used);
 561   if (len != d.elmsize)
 562     xbt_die("Bad size in MC_process_read_dynar_element");
 563   MC_process_read_simple(process, local, xbt_dynar_get_ptr(&d, i), len);
 564   return local;
 565 }
 566
 567 void MC_process_write(mc_process_t process, const void* local, void* remote, size_t len)
 568 {
 569   if (MC_process_is_self(process)) {
 570     memcpy(remote, local, len);
 571   } else {
 572     if (pwrite_whole(process->memory_file, local, len, (off_t) remote) < 0)
 573       xbt_die("Write to process %lli failed", (long long) process->pid);
 574   }
 575 }
 576
 577 unsigned long MC_process_read_dynar_length(mc_process_t process, const void* remote_dynar)
 578 {
 579   if (!remote_dynar)
 580     return 0;
 581   unsigned long res;
 582   MC_process_read_simple(process, &res,
 583     &((xbt_dynar_t)remote_dynar)->used, sizeof(res));
 584   return res;
 585 }
 586
 587 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
 588 static const void* zero_buffer;
 589 static const int zero_buffer_size = 10 * 4096;
 590
 591 static void MC_zero_buffer_init(void)
 592 {
 593   int fd = open("/dev/zero", O_RDONLY);
 594   if (fd<0)
 595     xbt_die("Could not open /dev/zero");
 596   zero_buffer = mmap(NULL, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
 597   if (zero_buffer == MAP_FAILED)
 598     xbt_die("Could not map the zero buffer");
 599   close(fd);
 600 }
 601
 602 void MC_process_clear_memory(mc_process_t process, void* remote, size_t len)
 603 {
 604   if (MC_process_is_self(process)) {
 605     memset(remote, 0, len);
 606   } else {
 607     pthread_once(&zero_buffer_flag, MC_zero_buffer_init);
 608     while (len) {
 609       size_t s = len > zero_buffer_size ? zero_buffer_size : len;
 610       MC_process_write(process, zero_buffer, remote, s);
 611       remote = (char*) remote + s;
 612       len -= s;
 613     }
 614   }
 615 }
 616
 617 void MC_simcall_handle(smx_simcall_t req, int value)
 618 {
 619   if (MC_process_is_self(&mc_model_checker->process)) {
 620     SIMIX_simcall_handle(req, value);
 621     return;
 622   }
 623
 624   MC_process_smx_refresh(&mc_model_checker->process);
 625
 626   unsigned i;
 627   mc_smx_process_info_t pi = NULL;
 628
 629   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, pi) {
 630     smx_process_t p = (smx_process_t) pi->address;
 631     if (req == &pi->copy.simcall) {
 632       smx_simcall_t real_req = &p->simcall;
 633       // TODO, use a remote call
 634       SIMIX_simcall_handle(real_req, value);
 635       return;
 636     }
 637   }
 638
 639   // Check (remove afterwards):
 640   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, pi) {
 641     smx_process_t p = (smx_process_t) pi->address;
 642     if (req == &p->simcall)
 643       xbt_die("The real simcall was passed. We expected the local copy.");
 644   }
 645
 646   xbt_die("Could not find the request");
 647 }