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