git.itanic.dy.fi Git - scan-pagemap/blob - parse.c

   1 #include <sys/types.h>
   2 #include <dirent.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <libgen.h>
   8
   9 #include "parse.h"
  10 #include "pagemap.h"
  11
  12 static struct maps_list *alloc_maplist(void)
  13 {
  14         struct maps_list *map;
  15
  16         map = malloc(sizeof *map);
  17         if (map == NULL)
  18                 goto err;
  19
  20         memset(map, 0, sizeof(*map));
  21         INIT_LIST_HEAD(&map->list);
  22 err:
  23         return map;
  24 }
  25
  26 static struct maps *alloc_map(void)
  27 {
  28         struct maps *map;
  29
  30         map = malloc(sizeof *map);
  31         if (map == NULL)
  32                 goto err;
  33
  34         memset(map, 0, sizeof(*map));
  35         INIT_LIST_HEAD(&map->list);
  36 err:
  37         return map;
  38 }
  39
  40 static struct maps *parse_maps(FILE *file, int pid, int tid)
  41 {
  42         struct maps *the_map = NULL;
  43         char line[1024];
  44         int ret;
  45
  46         while (fgets(line, sizeof(line), file)) {
  47                 struct maps *map = alloc_map();
  48                 unsigned long start, end;
  49                 char name[1024];
  50
  51                 if (map == NULL)
  52                         return 0;
  53
  54                 if (the_map == NULL)
  55                         the_map = map;
  56
  57                 ret = sscanf(line, "%lx-%lx %*s %*s %*s %*s %s",
  58                              &start, &end, name);
  59
  60                 if (ret < 2) {
  61                         printf("Error reading input: %s\n", line);
  62                         break;
  63                 }
  64
  65                 map->start = start;
  66                 map->end = end;
  67                 map->size = end - start;
  68                 map->pid = pid;
  69                 map->tid = tid;
  70
  71                 if (ret >= 3)
  72                         strncpy(map->name, name, sizeof(map->name));
  73
  74                 list_add_tail(&map->list, &the_map->list);
  75         }
  76
  77         return the_map;
  78 }
  79
  80 static void clear_pageframe(struct pageframe *pf)
  81 {
  82         memset(pf, 0, sizeof(*pf));
  83 }
  84
  85 static struct pageframe *alloc_pageframe(void)
  86 {
  87         struct pageframe *pageframe;
  88
  89         pageframe = malloc(sizeof *pageframe);
  90         if (pageframe == NULL)
  91                 goto err;
  92
  93         clear_pageframe(pageframe);
  94         INIT_LIST_HEAD(&pageframe->ml.list);
  95 err:
  96         return pageframe;
  97 }
  98
  99 static int compare_pageframe(struct bintree *at, struct bintree *bt)
 100 {
 101         struct pageframe *a, *b;
 102         a = tree_to_pageframe(at);
 103         b = tree_to_pageframe(bt);
 104
 105         return a->pf - b->pf;
 106 }
 107
 108 struct bintree_ops pageframe_ops = {
 109         .compare = compare_pageframe,
 110 };
 111
 112 static int read_cmdline(int pid, int tid, char *cmdline, size_t len)
 113 {
 114         FILE *file;
 115         char path[512];
 116         int ret;
 117
 118         snprintf(path, sizeof(path), "/proc/%d/task/%d/cmdline", pid, tid);
 119         file = fopen(path, "rb");
 120
 121         if (!file)
 122                 return -1;
 123
 124         ret = fread(cmdline, 1, len, file);
 125         if (ret > 0)
 126                 cmdline[ret - 1] = 0;
 127         fclose(file);
 128
 129         return ret > 0 ? 0 : -1;
 130 }
 131
 132 static char *get_name_by_pid(int pid)
 133 {
 134         static int last_pid;
 135         static char cmdline[128];
 136         static char *bname;
 137
 138         if (last_pid == pid)
 139                 return bname;
 140
 141         if (read_cmdline(pid, pid, cmdline, sizeof(cmdline))) {
 142                 bname = NULL;
 143                 return NULL;
 144         }
 145
 146         bname = basename(cmdline);
 147
 148         last_pid = pid;
 149         return bname;
 150 }
 151
 152 static int should_scan_process(struct parse_opts *opts, struct process *process)
 153 {
 154         int match = 0;
 155         char *name;
 156
 157         if (is_parse_option(opts, PARSE_PROCESS_NAME)) {
 158                 name = get_name_by_pid(process->pid);
 159                 if (!strcmp(opts->name, name ? name : ""))
 160                         match = 1;
 161         }
 162
 163         if (is_parse_option(opts, PARSE_PID)) {
 164                 if (opts->pid == process->pid)
 165                         match = 1;
 166         }
 167
 168         if (is_parse_option(opts, PARSE_MAP_NAME))
 169                 match = 1;
 170
 171         if (is_parse_option(opts, PARSE_NOADD_TREE))
 172                 match = !match;
 173
 174         return match;
 175 }
 176
 177 static int should_scan_mapping(struct parse_opts *opts, struct maps *map)
 178 {
 179         int match = 0;
 180
 181         if (is_parse_option(opts, PARSE_MAP_NAME)) {
 182                 if (!strcmp(opts->name, map->name))
 183                         match = 1;
 184
 185                 if (is_parse_option(opts, PARSE_NOADD_TREE))
 186                         match = !match;
 187         } else
 188                 match = 1;
 189
 190         return match;
 191 }
 192
 193 static int should_add_to_tree(struct parse_opts *opts, struct pageframe *pf,
 194                 struct maps *map)
 195 {
 196         if (is_parse_option(opts, PARSE_NOADD_TREE))
 197                 return 0;
 198
 199         return 1;
 200 }
 201
 202 /* Read data from the /proc/pid/pagemap file */
 203 static int parse_pageframe(FILE *file, struct pageframe *pf_tree,
 204                         struct maps *maps, struct parse_opts *opts)
 205 {
 206         struct maps *map;
 207         struct maps_list *tmp;
 208         struct pageframe *match, *pageframe = NULL;
 209         long start, len, i;
 210         unsigned long long pf[10240];
 211         int ret, error;
 212
 213         if (maps == NULL)
 214                 return 0;
 215
 216         /* Go through the list of allocated memory areas */
 217         list_for_each_entry(map, &maps->list, list) {
 218                 start = map->start >> (PAGE_SHIFT - 3);
 219                 len = map->size >> (PAGE_SHIFT);
 220
 221                 if (!should_scan_mapping(opts, map))
 222                         continue;
 223
 224                 ret = fseek(file, start, SEEK_SET);
 225                 if (ret) {
 226                         error = errno;
 227                         fprintf(stderr, "Error seeking to %lx: %s\n", start,
 228                                 strerror(error));
 229                         continue;
 230                 }
 231
 232                 for (i = 0; i < len; i++) {
 233                         if (!ret) {
 234                                 ret = fread(&pf, 1,
 235                                         MIN(sizeof(pf), (len - i) * 8), file);
 236                         }
 237                         if (ret < 0) {
 238                                 error = errno;
 239                                 continue;
 240                         }
 241                         if (!pageframe)
 242                                 pageframe = alloc_pageframe();
 243                         ret -= sizeof(pf[0]);
 244
 245                         /* ignore unused pages */
 246                         if (!pf[ret / sizeof(pf[0])])
 247                                 continue;
 248
 249                         pageframe->pf = (pf[ret / sizeof(pf[0])]);
 250
 251                         /* ignore unused pages */
 252                         if (!(page_swapped(pageframe) ||
 253                                         page_present(pageframe)))
 254                                 continue;
 255
 256                         if (should_add_to_tree(opts, pageframe, map)) {
 257                                 match = tree_to_pageframe(
 258                                         bintree_add(&pf_tree->tree,
 259                                                 &pageframe->tree,
 260                                                 &pageframe_ops));
 261                         } else {
 262                                 match = tree_to_pageframe(
 263                                         bintree_find(&pf_tree->tree,
 264                                                 &pageframe->tree,
 265                                                 &pageframe_ops));
 266                         }
 267
 268                         if (match == NULL)
 269                                 continue;
 270
 271                         if (match == pageframe)
 272                                 pageframe = NULL;
 273
 274                         match->refcount++;
 275                         /*
 276                          * Add a link from the physical page to this
 277                          * process's page map
 278                          */
 279                         tmp = alloc_maplist();
 280                         tmp->map = map;
 281                         list_add(&tmp->list, &match->ml.list);
 282
 283                         if (page_present(match))
 284                                 map->pages_present++;
 285                         else if (page_swapped(match))
 286                                 map->pages_swapped++;
 287                 }
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int read_pageframe(int pid, int tid, struct pageframe *pageframe,
 294                         struct process *process_list, struct parse_opts *opts)
 295 {
 296         struct maps *maps;
 297         struct process *process;
 298         FILE *file;
 299         char path[512];
 300
 301         process = malloc(sizeof(*process));
 302         memset(process, 0, sizeof(*process));
 303         INIT_LIST_HEAD(&process->list);
 304
 305         process->pid = pid;
 306         process->tid = tid;
 307
 308         if (!should_scan_process(opts, process))
 309                 goto free;
 310
 311         snprintf(path, sizeof(path), "/proc/%d/task/%d/maps", pid, tid);
 312         file = fopen(path, "rb");
 313
 314         if (!file)
 315                 goto free;
 316
 317         maps = parse_maps(file, pid, tid);
 318         fclose(file);
 319         process->maps = maps;
 320
 321         snprintf(path, sizeof(path), "/proc/%d/task/%d/pagemap", pid, tid);
 322         file = fopen(path, "rb");
 323
 324         if (!file)
 325                 goto free;
 326
 327         parse_pageframe(file, pageframe, maps, opts);
 328         fclose(file);
 329
 330         if (read_cmdline(pid, tid, process->name, sizeof(process->name)))
 331                 goto free;
 332
 333         if (maps != NULL) {
 334                 list_for_each_entry(maps, &process->maps->list, list) {
 335                         process->pages_present += maps->pages_present;
 336                         process->pages_swapped += maps->pages_swapped;
 337                 }
 338         }
 339
 340         list_add_tail(&process->list, &process_list->list);
 341
 342         return 1;
 343 free:
 344         free(process);
 345
 346         return 0;
 347 }
 348
 349 static int parse_pid(DIR **dir)
 350 {
 351         struct dirent *dirent;
 352         int error;
 353
 354 restart:
 355         dirent = readdir(*dir);
 356         if (!dirent) {
 357                 if (errno == 0) {
 358                         closedir(*dir);
 359                         *dir = NULL;
 360                         return 0;
 361                 }
 362                 error = errno;
 363                 printf("Failed to read /proc directory: %s\n", strerror(error));
 364                 return -1;
 365         }
 366
 367         if (dirent->d_name[0] < '0' || dirent->d_name[0] > '9')
 368                 goto restart;
 369
 370         return atoi(dirent->d_name);
 371 }
 372
 373 static int opendir_check(DIR **dir, const char *path)
 374 {
 375         int error;
 376
 377         if (!*dir) {
 378                 *dir = opendir(path);
 379                 if (!dir) {
 380                         error = errno;
 381                         fprintf(stderr, "Failed to open %s directory: %s\n",
 382                                 path, strerror(error));
 383                         return -1;
 384                 }
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int get_next_tid(int pid, DIR **dir)
 391 {
 392         if (*dir == NULL) {
 393                 char path[64];
 394
 395                 snprintf(path, sizeof(path), "/proc/%d/task/", pid);
 396                 if (opendir_check(dir, path))
 397                         return -1;
 398         }
 399
 400         return parse_pid(dir);
 401 }
 402
 403 static int get_next_pid(DIR **dir)
 404 {
 405         if (opendir_check(dir, "/proc"))
 406                 return -1;
 407
 408         return parse_pid(dir);
 409 }
 410
 411 static int get_next_pid_by_name(DIR **dir, char *name)
 412 {
 413         int pid;
 414         char *pname;
 415
 416         if (opendir_check(dir, "/proc"))
 417                 return -1;
 418
 419         while (1) {
 420                 pid = parse_pid(dir);
 421                 if (pid <= 0)
 422                         break;
 423
 424                 pname = get_name_by_pid(pid);
 425                 if (pname == NULL)
 426                         continue;
 427                 if (strcmp(pname, name))
 428                         continue;
 429
 430                 return pid;
 431         }
 432
 433         return 0;
 434 }
 435
 436 static int read_pageframe_with_threads(int pid,
 437                                 struct pageframe *pageframe,
 438                                 struct process *process_list,
 439                                 struct parse_opts *opts)
 440 {
 441         DIR *dir = NULL;
 442         int tid;
 443         int count = 0;
 444
 445         while (1) {
 446                 if (opts->with_threads)
 447                         tid = get_next_tid(pid, &dir);
 448                 else
 449                         tid = pid;
 450
 451                 if (tid <= 0)
 452                         return count;
 453
 454                 count += read_pageframe(pid, tid, pageframe, process_list,
 455                                         opts);
 456
 457                 if (!opts->with_threads)
 458                         break;
 459         }
 460
 461         return count;
 462 }
 463
 464 int scan_all_pids(struct pageframe *pf, struct process *process_list,
 465                 struct parse_opts *opts)
 466 {
 467         DIR *dir = NULL;
 468         int pid;
 469         int count = 0;
 470
 471         if (is_parse_option(opts, PARSE_PROCESS_NAME)) {
 472                 while ((pid = get_next_pid_by_name(&dir, opts->name))) {
 473                         count += read_pageframe_with_threads(pid, pf,
 474                                                         process_list,
 475                                                         opts);
 476                 }
 477                 dir = NULL;
 478         }
 479
 480         if (is_parse_option(opts, PARSE_PID))
 481                 count = read_pageframe_with_threads(opts->pid, pf, process_list,
 482                                                 opts);
 483
 484         if ((count == 0) && !(is_parse_option(opts, PARSE_MAP_NAME))) {
 485                 printf("Failed to find any matching processes "
 486                         "with given arguments\n");
 487                 return -1;
 488         }
 489
 490         if (is_parse_option(opts, PARSE_DUMP))
 491                 return 0;
 492
 493         if (is_parse_option(opts, PARSE_MAP_NAME)) {
 494                 while (1) {
 495                         pid = get_next_pid(&dir);
 496                         if (pid <= 0)
 497                                 break;
 498                         read_pageframe_with_threads(pid, pf, process_list,
 499                                                 opts);
 500                 }
 501         }
 502         /* Do not add new pages in the tree after the initial scan */
 503         opts->parse_mask |= PARSE_NOADD_TREE;
 504
 505         while (1) {
 506                 pid = get_next_pid(&dir);
 507                 if (pid <= 0)
 508                         break;
 509                 read_pageframe_with_threads(pid, pf, process_list, opts);
 510         }
 511
 512         return 0;
 513 }