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 = process->heap->heaplimit * sizeof(malloc_info);
 168
 169   xbt_mheap_t heap  = mmalloc_set_current_heap(mc_heap);
 170   process->heap_info = (malloc_info*) realloc(process->heap_info,
 171     malloc_info_bytesize);
 172   mmalloc_set_current_heap(heap);
 173
 174   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
 175     process->heap_info,
 176     process->heap->heapinfo, malloc_info_bytesize,
 177     MC_PROCESS_INDEX_DISABLED);
 178 }
 179
 180 #define SO_RE "\\.so[\\.0-9]*$"
 181 #define VERSION_RE "-[\\.0-9]*$"
 182
 183 const char* FILTERED_LIBS[] = {
 184   "libstdc++",
 185   "libc++",
 186   "libm",
 187   "libgcc_s",
 188   "libpthread",
 189   "libunwind",
 190   "libunwind-x86_64",
 191   "libunwind-x86",
 192   "libunwind-ptrace",
 193   "libdw",
 194   "libdl",
 195   "librt",
 196   "liblzma",
 197   "libelf",
 198   "libbz2",
 199   "libz",
 200   "libelf",
 201   "libc",
 202   "ld"
 203 };
 204
 205 static bool MC_is_simgrid_lib(const char* libname)
 206 {
 207   return !strcmp(libname, "libsimgrid");
 208 }
 209
 210 static bool MC_is_filtered_lib(const char* libname)
 211 {
 212   const size_t n = sizeof(FILTERED_LIBS) / sizeof(const char*);
 213   size_t i;
 214   for (i=0; i!=n; ++i)
 215     if (strcmp(libname, FILTERED_LIBS[i])==0)
 216       return true;
 217   return false;
 218 }
 219
 220 struct s_mc_memory_map_re {
 221   regex_t so_re;
 222   regex_t version_re;
 223 };
 224
 225 static char* MC_get_lib_name(const char* pathname, struct s_mc_memory_map_re* res) {
 226   const char* map_basename = basename((char*) pathname);
 227
 228   regmatch_t match;
 229   if(regexec(&res->so_re, map_basename, 1, &match, 0))
 230     return NULL;
 231
 232   char* libname = strndup(map_basename, match.rm_so);
 233
 234   // Strip the version suffix:
 235   if(libname && !regexec(&res->version_re, libname, 1, &match, 0)) {
 236     char* temp = libname;
 237     libname = strndup(temp, match.rm_so);
 238     free(temp);
 239   }
 240
 241   return libname;
 242 }
 243
 244 /** @brief Finds the range of the different memory segments and binary paths */
 245 static void MC_process_init_memory_map_info(mc_process_t process)
 246 {
 247   XBT_DEBUG("Get debug information ...");
 248   process->maestro_stack_start = NULL;
 249   process->maestro_stack_end = NULL;
 250   process->object_infos = NULL;
 251   process->object_infos_size = 0;
 252   process->binary_info = NULL;
 253   process->libsimgrid_info = NULL;
 254
 255   struct s_mc_memory_map_re res;
 256
 257   if(regcomp(&res.so_re, SO_RE, 0) || regcomp(&res.version_re, VERSION_RE, 0))
 258     xbt_die(".so regexp did not compile");
 259
 260   memory_map_t maps = process->memory_map;
 261
 262   const char* current_name = NULL;
 263
 264   size_t i = 0;
 265   for (i=0; i < maps->mapsize; i++) {
 266     map_region_t reg = &(maps->regions[i]);
 267     const char* pathname = maps->regions[i].pathname;
 268
 269     // Nothing to do
 270     if (maps->regions[i].pathname == NULL) {
 271       current_name = NULL;
 272       continue;
 273     }
 274
 275     // [stack], [vvar], [vsyscall], [vdso] ...
 276     if (pathname[0] == '[') {
 277       if ((reg->prot & PROT_WRITE) && !memcmp(pathname, "[stack]", 7)) {
 278         process->maestro_stack_start = reg->start_addr;
 279         process->maestro_stack_end = reg->end_addr;
 280       }
 281       current_name = NULL;
 282       continue;
 283     }
 284
 285     if (current_name && strcmp(current_name, pathname)==0)
 286       continue;
 287
 288     current_name = pathname;
 289     if (!(reg->prot & PROT_READ) && (reg->prot & PROT_EXEC))
 290       continue;
 291
 292     const bool is_executable = !i;
 293     char* libname = NULL;
 294     if (!is_executable) {
 295       libname = MC_get_lib_name(pathname, &res);
 296       if(!libname)
 297         continue;
 298       if (MC_is_filtered_lib(libname)) {
 299         free(libname);
 300         continue;
 301       }
 302     }
 303
 304     mc_object_info_t info =
 305       MC_find_object_info(process->memory_map, pathname, is_executable);
 306     process->object_infos = (mc_object_info_t*) realloc(process->object_infos,
 307       (process->object_infos_size+1) * sizeof(mc_object_info_t*));
 308     process->object_infos[process->object_infos_size] = info;
 309     process->object_infos_size++;
 310     if (is_executable)
 311       process->binary_info = info;
 312     else if (libname && MC_is_simgrid_lib(libname))
 313       process->libsimgrid_info = info;
 314     free(libname);
 315   }
 316
 317   regfree(&res.so_re);
 318   regfree(&res.version_re);
 319
 320   // Resolve time (including accress differents objects):
 321   for (i=0; i!=process->object_infos_size; ++i)
 322     MC_post_process_object_info(process, process->object_infos[i]);
 323
 324   xbt_assert(process->maestro_stack_start, "Did not find maestro_stack_start");
 325   xbt_assert(process->maestro_stack_end, "Did not find maestro_stack_end");
 326
 327   XBT_DEBUG("Get debug information done !");
 328 }
 329
 330 mc_object_info_t MC_process_find_object_info(mc_process_t process, const void *addr)
 331 {
 332   size_t i;
 333   for (i = 0; i != process->object_infos_size; ++i) {
 334     if (addr >= (void *) process->object_infos[i]->start
 335         && addr <= (void *) process->object_infos[i]->end) {
 336       return process->object_infos[i];
 337     }
 338   }
 339   return NULL;
 340 }
 341
 342 mc_object_info_t MC_process_find_object_info_exec(mc_process_t process, const void *addr)
 343 {
 344   size_t i;
 345   for (i = 0; i != process->object_infos_size; ++i) {
 346     if (addr >= (void *) process->object_infos[i]->start_exec
 347         && addr <= (void *) process->object_infos[i]->end_exec) {
 348       return process->object_infos[i];
 349     }
 350   }
 351   return NULL;
 352 }
 353
 354 mc_object_info_t MC_process_find_object_info_rw(mc_process_t process, const void *addr)
 355 {
 356   size_t i;
 357   for (i = 0; i != process->object_infos_size; ++i) {
 358     if (addr >= (void *) process->object_infos[i]->start_rw
 359         && addr <= (void *) process->object_infos[i]->end_rw) {
 360       return process->object_infos[i];
 361     }
 362   }
 363   return NULL;
 364 }
 365
 366 // Functions, variables…
 367
 368 dw_frame_t MC_process_find_function(mc_process_t process, const void *ip)
 369 {
 370   mc_object_info_t info = MC_process_find_object_info_exec(process, ip);
 371   if (info == NULL)
 372     return NULL;
 373   else
 374     return MC_file_object_info_find_function(info, ip);
 375 }
 376
 377 dw_variable_t MC_process_find_variable_by_name(mc_process_t process, const char* name)
 378 {
 379   const size_t n = process->object_infos_size;
 380   size_t i;
 381
 382   // First lookup the variable in the executable shared object.
 383   // A global variable used directly by the executable code from a library
 384   // is reinstanciated in the executable memory .data/.bss.
 385   // We need to look up the variable in the execvutable first.
 386   if (process->binary_info) {
 387     mc_object_info_t info = process->binary_info;
 388     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
 389     if (var)
 390       return var;
 391   }
 392
 393   for (i=0; i!=n; ++i) {
 394     mc_object_info_t info =process->object_infos[i];
 395     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
 396     if (var)
 397       return var;
 398   }
 399
 400   return NULL;
 401 }
 402
 403 void MC_process_read_variable(mc_process_t process, const char* name, void* target, size_t size)
 404 {
 405   dw_variable_t var = MC_process_find_variable_by_name(process, name);
 406   if (!var->address)
 407     xbt_die("No simple location for this variable");
 408   if (!var->type->full_type)
 409     xbt_die("Partial type for %s, cannot check size", name);
 410   if (var->type->full_type->byte_size != size)
 411     xbt_die("Unexpected size for %s (expected %zi, was %zi)",
 412       name, size, (size_t) var->type->full_type->byte_size);
 413   MC_process_read(process, MC_PROCESS_NO_FLAG, target, var->address, size,
 414     MC_PROCESS_INDEX_ANY);
 415 }
 416
 417 char* MC_process_read_string(mc_process_t process, void* address)
 418 {
 419   if (!address)
 420     return NULL;
 421   if (MC_process_is_self(process))
 422     return strdup((char*) address);
 423
 424   size_t len = 128;
 425   char* res = malloc(len);
 426   off_t off = 0;
 427
 428   while (1) {
 429     ssize_t c = pread(process->memory_file, res + off, len - off, (off_t) address + off);
 430     if (c == -1) {
 431       if (errno == EINTR)
 432         continue;
 433       else
 434         xbt_die("Could not read from from remote process");
 435     }
 436     if (c==0)
 437       xbt_die("Could not read string from remote process");
 438
 439     void* p = memchr(res + off, '\0', c);
 440     if (p)
 441       return res;
 442
 443     off += c;
 444     if (off == len) {
 445       len *= 2;
 446       res = realloc(res, len);
 447     }
 448   }
 449 }
 450
 451 // ***** Memory access
 452
 453 int MC_process_vm_open(pid_t pid, int flags)
 454 {
 455   const size_t buffer_size = 30;
 456   char buffer[buffer_size];
 457   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long) pid);
 458   if (res < 0 || res >= buffer_size) {
 459     errno = ENAMETOOLONG;
 460     return -1;
 461   }
 462   return open(buffer, flags);
 463 }
 464
 465 static void MC_process_open_memory_file(mc_process_t process)
 466 {
 467   if (MC_process_is_self(process) || process->memory_file >= 0)
 468     return;
 469
 470   int fd = MC_process_vm_open(process->pid, O_RDWR);
 471   if (fd<0)
 472     xbt_die("Could not open file for process virtual address space");
 473   process->memory_file = fd;
 474 }
 475
 476 static ssize_t pread_whole(int fd, void *buf, size_t count, off_t offset)
 477 {
 478   char* buffer = (char*) buf;
 479   ssize_t real_count = count;
 480   while (count) {
 481     ssize_t res = pread(fd, buffer, count, offset);
 482     if (res > 0) {
 483       count  -= res;
 484       buffer += res;
 485       offset += res;
 486     } else if (res==0) {
 487       return -1;
 488     } else if (errno != EINTR) {
 489       return -1;
 490     }
 491   }
 492   return real_count;
 493 }
 494
 495 static ssize_t pwrite_whole(int fd, const void *buf, size_t count, off_t offset)
 496 {
 497   const char* buffer = (const char*) buf;
 498   ssize_t real_count = count;
 499   while (count) {
 500     ssize_t res = pwrite(fd, buffer, count, offset);
 501     if (res > 0) {
 502       count  -= res;
 503       buffer += res;
 504       offset += res;
 505     } else if (res==0) {
 506       return -1;
 507     } else if (errno != EINTR) {
 508       return -1;
 509     }
 510   }
 511   return real_count;
 512 }
 513
 514 const void* MC_process_read(mc_process_t process, e_adress_space_read_flags_t flags,
 515   void* local, const void* remote, size_t len,
 516   int process_index)
 517 {
 518   if (process_index != MC_PROCESS_INDEX_DISABLED) {
 519     mc_object_info_t info = MC_process_find_object_info_rw(process, remote);
 520     // Segment overlap is not handled.
 521     if (MC_object_info_is_privatized(info)) {
 522       if (process_index < 0)
 523         xbt_die("Missing process index");
 524       // Address translation in the privaization segment:
 525       size_t offset = (const char*) remote - info->start_rw;
 526       remote = (const char*) remote - offset;
 527     }
 528   }
 529
 530   if (MC_process_is_self(process)) {
 531     if (flags & MC_ADDRESS_SPACE_READ_FLAGS_LAZY)
 532       return remote;
 533     else {
 534       memcpy(local, remote, len);
 535       return local;
 536     }
 537   } else {
 538     if (pread_whole(process->memory_file, local, len, (off_t) remote) < 0)
 539       xbt_die("Read from process %lli failed", (long long) process->pid);
 540     return local;
 541   }
 542 }
 543
 544 const void* MC_process_read_simple(mc_process_t process,
 545   void* local, const void* remote, size_t len)
 546 {
 547   e_adress_space_read_flags_t flags = MC_PROCESS_NO_FLAG;
 548   int index = MC_PROCESS_INDEX_ANY;
 549    MC_process_read(process, flags, local, remote, len, index);
 550    return local;
 551 }
 552
 553 const void* MC_process_read_dynar_element(mc_process_t process,
 554   void* local, const void* remote_dynar, size_t i, size_t len)
 555 {
 556   s_xbt_dynar_t d;
 557   MC_process_read_simple(process, &d, remote_dynar, sizeof(d));
 558   if (i >= d.used)
 559     xbt_die("Out of bound index %zi/%zi", i, d.used);
 560   if (len != d.elmsize)
 561     xbt_die("Bad size in MC_process_read_dynar_element");
 562   MC_process_read_simple(process, local, xbt_dynar_get_ptr(&d, i), len);
 563   return local;
 564 }
 565
 566 void MC_process_write(mc_process_t process, const void* local, void* remote, size_t len)
 567 {
 568   if (MC_process_is_self(process)) {
 569     memcpy(remote, local, len);
 570   } else {
 571     if (pwrite_whole(process->memory_file, local, len, (off_t) remote) < 0)
 572       xbt_die("Write to process %lli failed", (long long) process->pid);
 573   }
 574 }
 575
 576 unsigned long MC_process_read_dynar_length(mc_process_t process, const void* remote_dynar)
 577 {
 578   if (!remote_dynar)
 579     return 0;
 580   unsigned long res;
 581   MC_process_read_simple(process, &res,
 582     &((xbt_dynar_t)remote_dynar)->used, sizeof(res));
 583   return res;
 584 }
 585
 586 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
 587 static const void* zero_buffer;
 588 static const int zero_buffer_size = 10 * 4096;
 589
 590 static void MC_zero_buffer_init(void)
 591 {
 592   int fd = open("/dev/zero", O_RDONLY);
 593   if (fd<0)
 594     xbt_die("Could not open /dev/zero");
 595   zero_buffer = mmap(NULL, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
 596   if (zero_buffer == MAP_FAILED)
 597     xbt_die("Could not map the zero buffer");
 598   close(fd);
 599 }
 600
 601 void MC_process_clear_memory(mc_process_t process, void* remote, size_t len)
 602 {
 603   if (MC_process_is_self(process)) {
 604     memset(remote, 0, len);
 605   } else {
 606     pthread_once(&zero_buffer_flag, MC_zero_buffer_init);
 607     while (len) {
 608       size_t s = len > zero_buffer_size ? zero_buffer_size : len;
 609       MC_process_write(process, zero_buffer, remote, s);
 610       remote = (char*) remote + s;
 611       len -= s;
 612     }
 613   }
 614 }
 615
 616 void MC_simcall_handle(smx_simcall_t req, int value)
 617 {
 618   if (MC_process_is_self(&mc_model_checker->process)) {
 619     SIMIX_simcall_handle(req, value);
 620     return;
 621   }
 622
 623   MC_process_smx_refresh(&mc_model_checker->process);
 624
 625   unsigned i;
 626   mc_smx_process_info_t pi = NULL;
 627
 628   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, pi) {
 629     smx_process_t p = (smx_process_t) pi->address;
 630     if (req == &pi->copy.simcall) {
 631       smx_simcall_t real_req = &p->simcall;
 632       // TODO, use a remote call
 633       SIMIX_simcall_handle(real_req, value);
 634       return;
 635     }
 636   }
 637
 638   // Check (remove afterwards):
 639   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, pi) {
 640     smx_process_t p = (smx_process_t) pi->address;
 641     if (req == &p->simcall)
 642       xbt_die("The real simcall was passed. We expected the local copy.");
 643   }
 644
 645   xbt_die("Could not find the request");
 646 }