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 err:
  95         return pageframe;
  96 }
  97
  98 #define BITRANGE(first, last) (((2ll << (last - first)) - 1) << first)
  99
 100 static void pageframe_to_struct(unsigned long long p, struct pageframe *pf)
 101 {
 102         /* Refer Documentation/vm/pagemap.txt for the format */
 103         pf->page_present = !!(BITRANGE(63, 63) & p);
 104         pf->page_swapped = !!(BITRANGE(62, 62) & p);
 105         pf->page_shift   =   (BITRANGE(55, 60) & p) >> 55;
 106         pf->pfn          =   (BITRANGE(0, 54) & p);
 107         pf->swap_type    =   (BITRANGE(0, 4) & p);
 108         pf->swap_offset  =   (BITRANGE(5, 54) & p) >> 5;
 109 #if 0
 110         printf("pfn: %lx shift: %d present: %d swapped %d\n",
 111                 pf->pfn, pf->page_shift, pf->page_present, pf->page_swapped);
 112 #endif
 113 }
 114
 115 static int compare_pageframe(struct bintree *at, struct bintree *bt)
 116 {
 117         struct pageframe *a, *b;
 118         a = tree_to_pageframe(at);
 119         b = tree_to_pageframe(bt);
 120
 121         return a->pfn - b->pfn;
 122 }
 123
 124 struct bintree_ops pageframe_ops = {
 125         .compare = compare_pageframe,
 126 };
 127
 128 static int read_cmdline(int pid, int tid, char *cmdline, size_t len)
 129 {
 130         FILE *file;
 131         char path[512];
 132         int ret;
 133
 134         snprintf(path, sizeof(path), "/proc/%d/task/%d/cmdline", pid, tid);
 135         file = fopen(path, "rb");
 136
 137         if (!file)
 138                 return -1;
 139
 140         ret = fread(cmdline, 1, len, file);
 141         if (ret > 0)
 142                 cmdline[ret - 1] = 0;
 143         fclose(file);
 144
 145         return ret > 0 ? 0 : -1;
 146 }
 147
 148 static char *get_name_by_pid(int pid)
 149 {
 150         static int last_pid;
 151         static char cmdline[128];
 152         static char *bname;
 153
 154         if (last_pid == pid)
 155                 return bname;
 156
 157         if (read_cmdline(pid, pid, cmdline, sizeof(cmdline))) {
 158                 bname = NULL;
 159                 return NULL;
 160         }
 161
 162         bname = basename(cmdline);
 163
 164         last_pid = pid;
 165         return bname;
 166 }
 167
 168 static int check_parse_opts(struct parse_opts *opts, struct pageframe *pf,
 169                 struct maps *map)
 170 {
 171         if (opts->parse_mask & PARSE_PID) {
 172                 if (opts->pid == map->pid)
 173                         return 1;
 174         }
 175
 176         if (opts->parse_mask & PARSE_MAP_NAME) {
 177                 if (!strcmp(opts->name, map->name))
 178                         return 1;
 179         }
 180
 181         if (opts->parse_mask & PARSE_PROCESS_NAME) {
 182                 if (!strcmp(opts->name, get_name_by_pid(map->pid)))
 183                         return 1;
 184         }
 185
 186         return 0;
 187 }
 188
 189 /* Read data from the /proc/pid/pagemap file */
 190 static int parse_pageframe(FILE *file, struct pageframe *pf_tree,
 191                         struct maps *maps, struct parse_opts *opts)
 192 {
 193         struct maps *map;
 194         struct maps_list *tmp;
 195         struct pageframe *match, *pageframe = NULL;
 196         long start, len, i;
 197         unsigned long long pf[10240];
 198         int ret, error;
 199
 200         if (maps == NULL)
 201                 return 0;
 202
 203         /* Go through the list of allocated memory areas */
 204         list_for_each_entry(map, &maps->list, list) {
 205                 start = map->start >> (PAGE_SHIFT - 3);
 206                 len = map->size >> (PAGE_SHIFT - 3);
 207
 208                 ret = fseek(file, start, SEEK_SET);
 209                 if (ret) {
 210                         error = errno;
 211                         fprintf(stderr, "Error seeking to %lx: %s\n", start,
 212                                 strerror(error));
 213                         continue;
 214                 }
 215
 216                 for (i = 0; i < len; i++) {
 217                         if (!ret) {
 218                                 ret = fread(&pf, 1,
 219                                         MIN(sizeof(pf), (len - i) * 8), file);
 220                         }
 221                         if (ret < 0) {
 222                                 error = errno;
 223                                 continue;
 224                         }
 225                         if (!pageframe)
 226                                 pageframe = alloc_pageframe();
 227                         ret -= sizeof(pf[0]);
 228
 229                         /* ignore unused pages */
 230                         if (!pf[ret / sizeof(pf[0])])
 231                                 continue;
 232
 233                         pageframe_to_struct(pf[ret / sizeof(pf[0])], pageframe);
 234
 235                         /* ignore unused pages */
 236                         if (!(pageframe->page_swapped ||
 237                                         pageframe->page_present))
 238                                 continue;
 239
 240                         if (check_parse_opts(opts, pageframe, map)) {
 241                                 match = tree_to_pageframe(
 242                                         bintree_add(&pf_tree->tree,
 243                                                 &pageframe->tree,
 244                                                 &pageframe_ops));
 245                         } else {
 246                                 match = tree_to_pageframe(
 247                                         bintree_find(&pf_tree->tree,
 248                                                 &pageframe->tree,
 249                                                 &pageframe_ops));
 250                         }
 251
 252                         if (match == NULL)
 253                                 continue;
 254
 255                         if (match == pageframe)
 256                                 pageframe = NULL;
 257
 258                         match->refcount++;
 259                         /*
 260                          * Add a link from the physical page to this
 261                          * process's page map
 262                          */
 263                         if (!match->ml) {
 264                                 match->ml = alloc_maplist();
 265                                 match->ml->map = map;
 266                         } else {
 267                                 tmp = alloc_maplist();
 268                                 tmp->map = map;
 269                                 list_add(&match->ml->list, &tmp->list);
 270                         }
 271
 272                         if (match->page_present) {
 273                                 map->pages_present++;
 274                         } else if (match->page_swapped) {
 275                                 map->pages_swapped++;
 276                         }
 277                 }
 278         }
 279
 280         return 0;
 281 }
 282
 283 void read_pageframe(int pid, int tid, struct pageframe *pageframe,
 284                 struct process **process_list, struct parse_opts *opts)
 285 {
 286         struct maps *maps;
 287         struct process *process;
 288         FILE *file;
 289         char path[512];
 290
 291         process = malloc(sizeof(*process));
 292         memset(process, 0, sizeof(*process));
 293         INIT_LIST_HEAD(&process->list);
 294
 295         if (*process_list == NULL)
 296                 *process_list = process;
 297
 298         process->pid = pid;
 299         process->tid = tid;
 300
 301         list_add_tail(&process->list, &(*process_list)->list);
 302
 303         snprintf(path, sizeof(path), "/proc/%d/task/%d/maps", pid, tid);
 304         file = fopen(path, "rb");
 305
 306         if (!file)
 307                 return;
 308
 309         maps = parse_maps(file, pid, tid);
 310         fclose(file);
 311         process->maps = maps;
 312
 313         snprintf(path, sizeof(path), "/proc/%d/task/%d/pagemap", pid, tid);
 314         file = fopen(path, "rb");
 315
 316         if (!file)
 317                 return;
 318
 319         parse_pageframe(file, pageframe, maps, opts);
 320         fclose(file);
 321
 322         if (read_cmdline(pid, tid, process->name, sizeof(process->name)))
 323                 return;
 324
 325         if (maps == NULL)
 326                 return;
 327
 328         list_for_each_entry(maps, &process->maps->list, list) {
 329                 process->pages_present += maps->pages_present;
 330                 process->pages_swapped += maps->pages_swapped;
 331         }
 332
 333         return;
 334 }
 335
 336 static int parse_pid(DIR **dir)
 337 {
 338         struct dirent *dirent;
 339         int error;
 340
 341 restart:
 342         dirent = readdir(*dir);
 343         if (!dirent) {
 344                 if (errno == 0) {
 345                         closedir(*dir);
 346                         *dir = NULL;
 347                         return 0;
 348                 }
 349                 error = errno;
 350                 printf("Failed to read /proc directory: %s\n", strerror(error));
 351                 return -1;
 352         }
 353
 354         if (dirent->d_name[0] < '0' || dirent->d_name[0] > '9')
 355                 goto restart;
 356
 357         return atoi(dirent->d_name);
 358 }
 359
 360 static int opendir_check(DIR **dir, const char *path)
 361 {
 362         int error;
 363
 364         if (!*dir) {
 365                 *dir = opendir(path);
 366                 if (!dir) {
 367                         error = errno;
 368                         fprintf(stderr, "Failed to open %s directory: %s\n",
 369                                 path, strerror(error));
 370                         return -1;
 371                 }
 372         }
 373
 374         return 0;
 375 }
 376
 377 static int get_next_tid(int pid, DIR **dir)
 378 {
 379         if (*dir == NULL) {
 380                 char path[64];
 381
 382                 snprintf(path, sizeof(path), "/proc/%d/task/", pid);
 383                 if (opendir_check(dir, path))
 384                         return -1;
 385         }
 386
 387         return parse_pid(dir);
 388 }
 389
 390 static int get_next_pid(DIR **dir)
 391 {
 392         if (opendir_check(dir, "/proc"))
 393                 return -1;
 394
 395         return parse_pid(dir);
 396 }
 397
 398 static int get_next_pid_by_name(DIR **dir, char *name)
 399 {
 400         int pid;
 401         char *pname;
 402
 403         if (opendir_check(dir, "/proc"))
 404                 return -1;
 405
 406         while (1) {
 407                 pid = parse_pid(dir);
 408                 if (pid <= 0)
 409                         break;
 410
 411                 pname = get_name_by_pid(pid);
 412                 if (pname == NULL)
 413                         continue;
 414                 if (strcmp(pname, name))
 415                         continue;
 416
 417                 return pid;
 418         }
 419
 420         return 0;
 421 }
 422
 423 static void read_pageframe_with_threads(int pid,
 424                                         struct pageframe *pageframe,
 425                                         struct process **process_list,
 426                                         struct parse_opts *opts)
 427 {
 428         DIR *dir = NULL;
 429         int tid;
 430
 431         while (1) {
 432                 if (opts->with_threads)
 433                         tid = get_next_tid(pid, &dir);
 434                 else
 435                         tid = pid;
 436
 437                 if (tid <= 0)
 438                         return;
 439
 440                 read_pageframe(pid, tid, pageframe, process_list, opts);
 441
 442                 if (!opts->with_threads)
 443                         break;
 444         }
 445 }
 446
 447 void scan_all_pids(struct pageframe *pf, struct process **process_list,
 448                 struct parse_opts *opts)
 449 {
 450         DIR *dir = NULL;
 451         int pid;
 452
 453         if (opts->parse_mask & PARSE_PROCESS_NAME) {
 454                 while ((pid = get_next_pid_by_name(&dir, opts->name))) {
 455                         read_pageframe_with_threads(pid, pf, process_list,
 456                                                 opts);
 457                 }
 458                 dir = NULL;
 459         }
 460
 461         if (opts->parse_mask & PARSE_PID)
 462                 read_pageframe_with_threads(opts->pid, pf, process_list, opts);
 463
 464         while(1) {
 465                 pid = get_next_pid(&dir);
 466                 if (pid <= 0)
 467                         break;
 468                 read_pageframe_with_threads(pid, pf, process_list, opts);
 469         }
 470 }