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 <libgen.h>
  14
  15 #include "mc_process.h"
  16 #include "mc_object_info.h"
  17 #include "mc_address_space.h"
  18
  19 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc,
  20                                 "MC process information");
  21
  22 static void MC_process_init_memory_map_info(mc_process_t process);
  23 static void MC_process_open_memory_file(mc_process_t process);
  24
  25 static s_mc_address_space_class_t mc_process_class = {
  26   .read = (void*) &MC_process_read
  27 };
  28
  29 void MC_process_init(mc_process_t process, pid_t pid)
  30 {
  31   process->address_space.address_space_class = &mc_process_class;
  32   process->process_flags = MC_PROCESS_NO_FLAG;
  33   process->pid = pid;
  34   if (pid==getpid())
  35     process->process_flags |= MC_PROCESS_SELF_FLAG;
  36   process->memory_map = MC_get_memory_map(pid);
  37   process->memory_file = -1;
  38   process->cache_flags = 0;
  39   process->heap = NULL;
  40   process->heap_info = NULL;
  41   MC_process_init_memory_map_info(process);
  42   MC_process_open_memory_file(process);
  43
  44   // Read std_heap (is a struct mdesc*):
  45   dw_variable_t std_heap_var = MC_process_find_variable_by_name(process, "std_heap");
  46   if (!std_heap_var)
  47     xbt_die("No heap information in the target process");
  48   if(!std_heap_var->address)
  49     xbt_die("No constant address for this variable");
  50   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
  51     &process->heap_address, std_heap_var->address, sizeof(struct mdesc*),
  52     MC_PROCESS_INDEX_DISABLED);
  53 }
  54
  55 void MC_process_clear(mc_process_t process)
  56 {
  57   process->address_space.address_space_class = NULL;
  58   process->process_flags = MC_PROCESS_NO_FLAG;
  59   process->pid = 0;
  60
  61   MC_free_memory_map(process->memory_map);
  62   process->memory_map = NULL;
  63
  64   process->maestro_stack_start = NULL;
  65   process->maestro_stack_end = NULL;
  66
  67   size_t i;
  68   for (i=0; i!=process->object_infos_size; ++i) {
  69     MC_free_object_info(&process->object_infos[i]);
  70   }
  71   free(process->object_infos);
  72   process->object_infos = NULL;
  73   process->object_infos_size = 0;
  74   if (process->memory_file >= 0) {
  75     close(process->memory_file);
  76   }
  77
  78   process->cache_flags = 0;
  79
  80   free(process->heap);
  81   process->heap = NULL;
  82
  83   free(process->heap_info);
  84   process->heap_info = NULL;
  85 }
  86
  87 void MC_process_refresh_heap(mc_process_t process)
  88 {
  89   assert(!MC_process_is_self(process));
  90   // Read/dereference/refresh the std_heap pointer:
  91   if (!process->heap) {
  92     xbt_mheap_t oldheap  = mmalloc_get_current_heap();
  93     MC_SET_MC_HEAP;
  94     process->heap = malloc(sizeof(struct mdesc));
  95     mmalloc_set_current_heap(oldheap);
  96   }
  97   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
  98     process->heap, process->heap_address, sizeof(struct mdesc),
  99     MC_PROCESS_INDEX_DISABLED
 100     );
 101 }
 102
 103 void MC_process_refresh_malloc_info(mc_process_t process)
 104 {
 105   assert(!MC_process_is_self(process));
 106   if (!process->cache_flags & MC_PROCESS_CACHE_FLAG_HEAP)
 107     MC_process_refresh_heap(process);
 108   // Refresh process->heapinfo:
 109   size_t malloc_info_bytesize = process->heap->heaplimit * sizeof(malloc_info);
 110
 111   xbt_mheap_t oldheap  = mmalloc_get_current_heap();
 112   MC_SET_MC_HEAP;
 113   process->heap_info = (malloc_info*) realloc(process->heap_info,
 114     malloc_info_bytesize);
 115   mmalloc_set_current_heap(oldheap);
 116
 117   MC_process_read(process, MC_ADDRESS_SPACE_READ_FLAGS_NONE,
 118     process->heap_info,
 119     process->heap->heapinfo, malloc_info_bytesize,
 120     MC_PROCESS_INDEX_DISABLED);
 121 }
 122
 123 #define SO_RE "\\.so[\\.0-9]*$"
 124 #define VERSION_RE "-[\\.0-9]*$"
 125
 126 const char* FILTERED_LIBS[] = {
 127   "libstdc++",
 128   "libc++",
 129   "libm",
 130   "libgcc_s",
 131   "libpthread",
 132   "libunwind",
 133   "libunwind-x86_64",
 134   "libunwind-x86",
 135   "libdw",
 136   "libdl",
 137   "librt",
 138   "liblzma",
 139   "libelf",
 140   "libbz2",
 141   "libz",
 142   "libelf",
 143   "libc",
 144   "ld"
 145 };
 146
 147 static bool MC_is_simgrid_lib(const char* libname)
 148 {
 149   return !strcmp(libname, "libsimgrid");
 150 }
 151
 152 static bool MC_is_filtered_lib(const char* libname)
 153 {
 154   const size_t n = sizeof(FILTERED_LIBS) / sizeof(const char*);
 155   size_t i;
 156   for (i=0; i!=n; ++i)
 157     if (strcmp(libname, FILTERED_LIBS[i])==0)
 158       return true;
 159   return false;
 160 }
 161
 162 struct s_mc_memory_map_re {
 163   regex_t so_re;
 164   regex_t version_re;
 165 };
 166
 167 static char* MC_get_lib_name(const char* pathname, struct s_mc_memory_map_re* res) {
 168   const char* map_basename = basename((char*) pathname);
 169
 170   regmatch_t match;
 171   if(regexec(&res->so_re, map_basename, 1, &match, 0))
 172     return NULL;
 173
 174   char* libname = strndup(map_basename, match.rm_so);
 175
 176   // Strip the version suffix:
 177   if(libname && !regexec(&res->version_re, libname, 1, &match, 0)) {
 178     char* temp = libname;
 179     libname = strndup(temp, match.rm_so);
 180     free(temp);
 181   }
 182
 183   return libname;
 184 }
 185
 186 /** @brief Finds the range of the different memory segments and binary paths */
 187 static void MC_process_init_memory_map_info(mc_process_t process)
 188 {
 189   XBT_INFO("Get debug information ...");
 190   process->maestro_stack_start = NULL;
 191   process->maestro_stack_end = NULL;
 192   process->object_infos = NULL;
 193   process->object_infos_size = 0;
 194   process->binary_info = NULL;
 195   process->libsimgrid_info = NULL;
 196
 197   struct s_mc_memory_map_re res;
 198
 199   if(regcomp(&res.so_re, SO_RE, 0) || regcomp(&res.version_re, VERSION_RE, 0))
 200     xbt_die(".so regexp did not compile");
 201
 202   memory_map_t maps = process->memory_map;
 203
 204   const char* current_name = NULL;
 205
 206   size_t i = 0;
 207   for (i=0; i < maps->mapsize; i++) {
 208     map_region_t reg = &(maps->regions[i]);
 209     const char* pathname = maps->regions[i].pathname;
 210
 211     // Nothing to do
 212     if (maps->regions[i].pathname == NULL) {
 213       current_name = NULL;
 214       continue;
 215     }
 216
 217     // [stack], [vvar], [vsyscall], [vdso] ...
 218     if (pathname[0] == '[') {
 219       if ((reg->prot & PROT_WRITE) && !memcmp(pathname, "[stack]", 7)) {
 220         process->maestro_stack_start = reg->start_addr;
 221         process->maestro_stack_end = reg->end_addr;
 222       }
 223       current_name = NULL;
 224       continue;
 225     }
 226
 227     if (current_name && strcmp(current_name, pathname)==0)
 228       continue;
 229
 230     current_name = pathname;
 231     if (!(reg->prot & PROT_READ) && (reg->prot & PROT_EXEC))
 232       continue;
 233
 234     const bool is_executable = !i;
 235     char* libname = NULL;
 236     if (!is_executable) {
 237       libname = MC_get_lib_name(pathname, &res);
 238       if(!libname)
 239         continue;
 240       if (MC_is_filtered_lib(libname)) {
 241         free(libname);
 242         continue;
 243       }
 244     }
 245
 246     mc_object_info_t info =
 247       MC_find_object_info(process->memory_map, pathname, is_executable);
 248     process->object_infos = (mc_object_info_t*) realloc(process->object_infos,
 249       (process->object_infos_size+1) * sizeof(mc_object_info_t*));
 250     process->object_infos[process->object_infos_size] = info;
 251     process->object_infos_size++;
 252     if (is_executable)
 253       process->binary_info = info;
 254     else if (libname && MC_is_simgrid_lib(libname))
 255       process->libsimgrid_info = info;
 256     free(libname);
 257   }
 258
 259   regfree(&res.so_re);
 260   regfree(&res.version_re);
 261
 262   // Resolve time (including accress differents objects):
 263   for (i=0; i!=process->object_infos_size; ++i)
 264     MC_post_process_object_info(process, process->object_infos[i]);
 265
 266   xbt_assert(process->maestro_stack_start, "maestro_stack_start");
 267   xbt_assert(process->maestro_stack_end, "maestro_stack_end");
 268
 269   XBT_INFO("Get debug information done !");
 270 }
 271
 272 mc_object_info_t MC_process_find_object_info(mc_process_t process, const void *addr)
 273 {
 274   size_t i;
 275   for (i = 0; i != process->object_infos_size; ++i) {
 276     if (addr >= (void *) process->object_infos[i]->start
 277         && addr <= (void *) process->object_infos[i]->end) {
 278       return process->object_infos[i];
 279     }
 280   }
 281   return NULL;
 282 }
 283
 284 mc_object_info_t MC_process_find_object_info_exec(mc_process_t process, const void *addr)
 285 {
 286   size_t i;
 287   for (i = 0; i != process->object_infos_size; ++i) {
 288     if (addr >= (void *) process->object_infos[i]->start_exec
 289         && addr <= (void *) process->object_infos[i]->end_exec) {
 290       return process->object_infos[i];
 291     }
 292   }
 293   return NULL;
 294 }
 295
 296 mc_object_info_t MC_process_find_object_info_rw(mc_process_t process, const void *addr)
 297 {
 298   size_t i;
 299   for (i = 0; i != process->object_infos_size; ++i) {
 300     if (addr >= (void *) process->object_infos[i]->start_rw
 301         && addr <= (void *) process->object_infos[i]->end_rw) {
 302       return process->object_infos[i];
 303     }
 304   }
 305   return NULL;
 306 }
 307
 308 // Functions, variables…
 309
 310 dw_frame_t MC_process_find_function(mc_process_t process, const void *ip)
 311 {
 312   mc_object_info_t info = MC_process_find_object_info_exec(process, ip);
 313   if (info == NULL)
 314     return NULL;
 315   else
 316     return MC_file_object_info_find_function(info, ip);
 317 }
 318
 319 dw_variable_t MC_process_find_variable_by_name(mc_process_t process, const char* name)
 320 {
 321   const size_t n = process->object_infos_size;
 322   size_t i;
 323   for (i=0; i!=n; ++i) {
 324     mc_object_info_t info =process->object_infos[i];
 325     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
 326     if (var)
 327       return var;
 328   }
 329   return NULL;
 330 }
 331
 332 // ***** Memory access
 333
 334 static void MC_process_open_memory_file(mc_process_t process)
 335 {
 336   if (MC_process_is_self(process) || process->memory_file >= 0)
 337     return;
 338
 339   const size_t buffer_size = 30;
 340   char buffer[buffer_size];
 341   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long) process->pid);
 342   if (res < 0 || res>= buffer_size) {
 343     XBT_ERROR("Could not open memory file descriptor for process %lli",
 344       (long long) process->pid);
 345     return;
 346   }
 347
 348   int fd = open(buffer, O_RDWR);
 349   if (fd<0)
 350     xbt_die("Could not initialise memory access for remote process");
 351   process->memory_file = fd;
 352 }
 353
 354 static ssize_t pread_whole(int fd, void *buf, size_t count, off_t offset)
 355 {
 356   char* buffer = (char*) buf;
 357   ssize_t real_count = count;
 358   while (count) {
 359     ssize_t res = pread(fd, buffer, count, offset);
 360     if (res > 0) {
 361       count  -= res;
 362       buffer += res;
 363       offset += res;
 364     } else if (res==0) {
 365       return -1;
 366     } else if (errno != EINTR) {
 367       return -1;
 368     }
 369   }
 370   return real_count;
 371 }
 372
 373 static ssize_t pwrite_whole(int fd, const void *buf, size_t count, off_t offset)
 374 {
 375   const char* buffer = (const char*) buf;
 376   ssize_t real_count = count;
 377   while (count) {
 378     ssize_t res = pwrite(fd, buffer, count, offset);
 379     if (res > 0) {
 380       count  -= res;
 381       buffer += res;
 382       offset += res;
 383     } else if (res==0) {
 384       return -1;
 385     } else if (errno != EINTR) {
 386       return -1;
 387     }
 388   }
 389   return real_count;
 390 }
 391
 392 const void* MC_process_read(mc_process_t process, e_adress_space_read_flags_t flags,
 393   void* local, const void* remote, size_t len,
 394   int process_index)
 395 {
 396   if (process_index != MC_PROCESS_INDEX_DISABLED) {
 397     mc_object_info_t info = MC_process_find_object_info_rw(process, remote);
 398     // Segment overlap is not handled.
 399     if (MC_object_info_is_privatized(info)) {
 400       if (process_index < 0)
 401         xbt_die("Missing process index");
 402       // Address translation in the privaization segment:
 403       size_t offset = (const char*) remote - info->start_rw;
 404       remote = (const char*) remote - offset;
 405     }
 406   }
 407
 408   if (MC_process_is_self(process)) {
 409     if (flags & MC_ADDRESS_SPACE_READ_FLAGS_LAZY)
 410       return remote;
 411     else {
 412       memcpy(local, remote, len);
 413       return local;
 414     }
 415   } else {
 416     if (pread_whole(process->memory_file, local, len, (off_t) remote) < 0)
 417       xbt_die("Read from process %lli failed", (long long) process->pid);
 418     return local;
 419   }
 420 }
 421
 422 void MC_process_write(mc_process_t process, const void* local, void* remote, size_t len)
 423 {
 424   if (MC_process_is_self(process)) {
 425     memcpy(remote, local, len);
 426   } else {
 427     if (pwrite_whole(process->memory_file, local, len, (off_t) remote) < 0)
 428       xbt_die("Write to process %lli failed", (long long) process->pid);
 429   }
 430 }