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 #define BITRANGE(first, last) (((2ll << (last - first)) - 1) << first)
 100
 101 static void pageframe_to_struct(unsigned long long p, struct pageframe *pf)
 102 {
 103         /* Refer Documentation/vm/pagemap.txt for the format */
 104         pf->page_present = !!(BITRANGE(63, 63) & p);
 105         pf->page_swapped = !!(BITRANGE(62, 62) & p);
 106         pf->page_shift   =   (BITRANGE(55, 60) & p) >> 55;
 107         pf->pfn          =   (BITRANGE(0, 54) & p);
 108         pf->swap_type    =   (BITRANGE(0, 4) & p);
 109         pf->swap_offset  =   (BITRANGE(5, 54) & p) >> 5;
 110 #if 0
 111         printf("pfn: %lx shift: %d present: %d swapped %d\n",
 112                 pf->pfn, pf->page_shift, pf->page_present, pf->page_swapped);
 113 #endif
 114 }
 115
 116 static int compare_pageframe(struct bintree *at, struct bintree *bt)
 117 {
 118         struct pageframe *a, *b;
 119         a = tree_to_pageframe(at);
 120         b = tree_to_pageframe(bt);
 121
 122         return a->pfn - b->pfn;
 123 }
 124
 125 struct bintree_ops pageframe_ops = {
 126         .compare = compare_pageframe,
 127 };
 128
 129 static int read_cmdline(int pid, int tid, char *cmdline, size_t len)
 130 {
 131         FILE *file;
 132         char path[512];
 133         int ret;
 134
 135         snprintf(path, sizeof(path), "/proc/%d/task/%d/cmdline", pid, tid);
 136         file = fopen(path, "rb");
 137
 138         if (!file)
 139                 return -1;
 140
 141         ret = fread(cmdline, 1, len, file);
 142         if (ret > 0)
 143                 cmdline[ret - 1] = 0;
 144         fclose(file);
 145
 146         return ret > 0 ? 0 : -1;
 147 }
 148
 149 static char *get_name_by_pid(int pid)
 150 {
 151         static int last_pid;
 152         static char cmdline[128];
 153         static char *bname;
 154
 155         if (last_pid == pid)
 156                 return bname;
 157
 158         if (read_cmdline(pid, pid, cmdline, sizeof(cmdline))) {
 159                 bname = NULL;
 160                 return NULL;
 161         }
 162
 163         bname = basename(cmdline);
 164
 165         last_pid = pid;
 166         return bname;
 167 }
 168
 169 static int should_scan_process(struct parse_opts *opts, struct process *process)
 170 {
 171         int match = 0;
 172         char *name;
 173
 174         if (opts->parse_mask & PARSE_PROCESS_NAME) {
 175                 name = get_name_by_pid(process->pid);
 176                 if (!strcmp(opts->name, name ? name : ""))
 177                         match = 1;
 178         }
 179
 180         if (opts->parse_mask & PARSE_PID) {
 181                 if (opts->pid == process->pid)
 182                         match = 1;
 183         }
 184
 185         if (opts->parse_mask & PARSE_NOADD_TREE)
 186                 match = !match;
 187
 188         return match;
 189 }
 190
 191 static int should_scan_mapping(struct parse_opts *opts, struct maps *map)
 192 {
 193         int match = 0;
 194
 195         if (opts->parse_mask & PARSE_MAP_NAME) {
 196                 if (!strcmp(opts->name, map->name))
 197                         match = 1;
 198
 199                 if (opts->parse_mask & PARSE_NOADD_TREE)
 200                         match = !match;
 201         } else
 202                 match = 1;
 203
 204         return match;
 205 }
 206
 207 static int should_add_to_tree(struct parse_opts *opts, struct pageframe *pf,
 208                 struct maps *map)
 209 {
 210         if (opts->parse_mask & PARSE_NOADD_TREE)
 211                 return 0;
 212
 213         return 1;
 214 }
 215
 216 /* Read data from the /proc/pid/pagemap file */
 217 static int parse_pageframe(FILE *file, struct pageframe *pf_tree,
 218                         struct maps *maps, struct parse_opts *opts)
 219 {
 220         struct maps *map;
 221         struct maps_list *tmp;
 222         struct pageframe *match, *pageframe = NULL;
 223         long start, len, i;
 224         unsigned long long pf[10240];
 225         int ret, error;
 226
 227         if (maps == NULL)
 228                 return 0;
 229
 230         /* Go through the list of allocated memory areas */
 231         list_for_each_entry(map, &maps->list, list) {
 232                 start = map->start >> (PAGE_SHIFT - 3);
 233                 len = map->size >> (PAGE_SHIFT);
 234
 235                 if (!should_scan_mapping(opts, map))
 236                         continue;
 237
 238                 ret = fseek(file, start, SEEK_SET);
 239                 if (ret) {
 240                         error = errno;
 241                         fprintf(stderr, "Error seeking to %lx: %s\n", start,
 242                                 strerror(error));
 243                         continue;
 244                 }
 245
 246                 for (i = 0; i < len; i++) {
 247                         if (!ret) {
 248                                 ret = fread(&pf, 1,
 249                                         MIN(sizeof(pf), (len - i) * 8), file);
 250                         }
 251                         if (ret < 0) {
 252                                 error = errno;
 253                                 continue;
 254                         }
 255                         if (!pageframe)
 256                                 pageframe = alloc_pageframe();
 257                         ret -= sizeof(pf[0]);
 258
 259                         /* ignore unused pages */
 260                         if (!pf[ret / sizeof(pf[0])])
 261                                 continue;
 262
 263                         pageframe_to_struct(pf[ret / sizeof(pf[0])], pageframe);
 264
 265                         /* ignore unused pages */
 266                         if (!(pageframe->page_swapped ||
 267                                         pageframe->page_present))
 268                                 continue;
 269
 270                         if (should_add_to_tree(opts, pageframe, map)) {
 271                                 match = tree_to_pageframe(
 272                                         bintree_add(&pf_tree->tree,
 273                                                 &pageframe->tree,
 274                                                 &pageframe_ops));
 275                         } else {
 276                                 match = tree_to_pageframe(
 277                                         bintree_find(&pf_tree->tree,
 278                                                 &pageframe->tree,
 279                                                 &pageframe_ops));
 280                         }
 281
 282                         if (match == NULL)
 283                                 continue;
 284
 285                         if (match == pageframe)
 286                                 pageframe = NULL;
 287
 288                         match->refcount++;
 289                         /*
 290                          * Add a link from the physical page to this
 291                          * process's page map
 292                          */
 293                         tmp = alloc_maplist();
 294                         tmp->map = map;
 295                         list_add(&tmp->list, &match->ml.list);
 296
 297                         if (match->page_present)
 298                                 map->pages_present++;
 299                         else if (match->page_swapped)
 300                                 map->pages_swapped++;
 301                 }
 302         }
 303
 304         return 0;
 305 }
 306
 307 static int read_pageframe(int pid, int tid, struct pageframe *pageframe,
 308                         struct process *process_list, struct parse_opts *opts)
 309 {
 310         struct maps *maps;
 311         struct process *process;
 312         FILE *file;
 313         char path[512];
 314
 315         process = malloc(sizeof(*process));
 316         memset(process, 0, sizeof(*process));
 317         INIT_LIST_HEAD(&process->list);
 318
 319         process->pid = pid;
 320         process->tid = tid;
 321
 322         if (!should_scan_process(opts, process))
 323                 goto free;
 324
 325         snprintf(path, sizeof(path), "/proc/%d/task/%d/maps", pid, tid);
 326         file = fopen(path, "rb");
 327
 328         if (!file)
 329                 goto free;
 330
 331         maps = parse_maps(file, pid, tid);
 332         fclose(file);
 333         process->maps = maps;
 334
 335         snprintf(path, sizeof(path), "/proc/%d/task/%d/pagemap", pid, tid);
 336         file = fopen(path, "rb");
 337
 338         if (!file)
 339                 goto free;
 340
 341         parse_pageframe(file, pageframe, maps, opts);
 342         fclose(file);
 343
 344         if (read_cmdline(pid, tid, process->name, sizeof(process->name)))
 345                 goto free;
 346
 347         if (maps != NULL) {
 348                 list_for_each_entry(maps, &process->maps->list, list) {
 349                         process->pages_present += maps->pages_present;
 350                         process->pages_swapped += maps->pages_swapped;
 351                 }
 352         }
 353
 354         list_add_tail(&process->list, &process_list->list);
 355
 356         return 1;
 357 free:
 358         free(process);
 359
 360         return 0;
 361 }
 362
 363 static int parse_pid(DIR **dir)
 364 {
 365         struct dirent *dirent;
 366         int error;
 367
 368 restart:
 369         dirent = readdir(*dir);
 370         if (!dirent) {
 371                 if (errno == 0) {
 372                         closedir(*dir);
 373                         *dir = NULL;
 374                         return 0;
 375                 }
 376                 error = errno;
 377                 printf("Failed to read /proc directory: %s\n", strerror(error));
 378                 return -1;
 379         }
 380
 381         if (dirent->d_name[0] < '0' || dirent->d_name[0] > '9')
 382                 goto restart;
 383
 384         return atoi(dirent->d_name);
 385 }
 386
 387 static int opendir_check(DIR **dir, const char *path)
 388 {
 389         int error;
 390
 391         if (!*dir) {
 392                 *dir = opendir(path);
 393                 if (!dir) {
 394                         error = errno;
 395                         fprintf(stderr, "Failed to open %s directory: %s\n",
 396                                 path, strerror(error));
 397                         return -1;
 398                 }
 399         }
 400
 401         return 0;
 402 }
 403
 404 static int get_next_tid(int pid, DIR **dir)
 405 {
 406         if (*dir == NULL) {
 407                 char path[64];
 408
 409                 snprintf(path, sizeof(path), "/proc/%d/task/", pid);
 410                 if (opendir_check(dir, path))
 411                         return -1;
 412         }
 413
 414         return parse_pid(dir);
 415 }
 416
 417 static int get_next_pid(DIR **dir)
 418 {
 419         if (opendir_check(dir, "/proc"))
 420                 return -1;
 421
 422         return parse_pid(dir);
 423 }
 424
 425 static int get_next_pid_by_name(DIR **dir, char *name)
 426 {
 427         int pid;
 428         char *pname;
 429
 430         if (opendir_check(dir, "/proc"))
 431                 return -1;
 432
 433         while (1) {
 434                 pid = parse_pid(dir);
 435                 if (pid <= 0)
 436                         break;
 437
 438                 pname = get_name_by_pid(pid);
 439                 if (pname == NULL)
 440                         continue;
 441                 if (strcmp(pname, name))
 442                         continue;
 443
 444                 return pid;
 445         }
 446
 447         return 0;
 448 }
 449
 450 static int read_pageframe_with_threads(int pid,
 451                                 struct pageframe *pageframe,
 452                                 struct process *process_list,
 453                                 struct parse_opts *opts)
 454 {
 455         DIR *dir = NULL;
 456         int tid;
 457         int count = 0;
 458
 459         while (1) {
 460                 if (opts->with_threads)
 461                         tid = get_next_tid(pid, &dir);
 462                 else
 463                         tid = pid;
 464
 465                 if (tid <= 0)
 466                         return count;
 467
 468                 count += read_pageframe(pid, tid, pageframe, process_list,
 469                                         opts);
 470
 471                 if (!opts->with_threads)
 472                         break;
 473         }
 474
 475         return count;
 476 }
 477
 478 int scan_all_pids(struct pageframe *pf, struct process *process_list,
 479                 struct parse_opts *opts)
 480 {
 481         DIR *dir = NULL;
 482         int pid;
 483         int count = 0;
 484
 485         if (opts->parse_mask & PARSE_PROCESS_NAME) {
 486                 while ((pid = get_next_pid_by_name(&dir, opts->name))) {
 487                         count += read_pageframe_with_threads(pid, pf,
 488                                                         process_list,
 489                                                         opts);
 490                 }
 491                 dir = NULL;
 492         }
 493
 494         if (opts->parse_mask & PARSE_PID)
 495                 count = read_pageframe_with_threads(opts->pid, pf, process_list,
 496                                                 opts);
 497
 498         if ((count == 0) && !(opts->parse_mask & PARSE_MAP_NAME)) {
 499                 printf("Failed to find any matching processes "
 500                         "with given arguments\n");
 501                 return -1;
 502         }
 503
 504         if (opts->parse_mask & PARSE_DUMP)
 505                 return 0;
 506
 507         /* Do not add new pages in the tree after the initial scan */
 508         opts->parse_mask |= PARSE_NOADD_TREE;
 509
 510         while (1) {
 511                 pid = get_next_pid(&dir);
 512                 if (pid <= 0)
 513                         break;
 514                 read_pageframe_with_threads(pid, pf, process_list, opts);
 515         }
 516
 517         return 0;
 518 }