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
   8 #include "parse.h"
   9 #include "pagemap.h"
  10
  11 static struct maps_list *alloc_maplist(void)
  12 {
  13         struct maps_list *map;
  14
  15         map = malloc(sizeof *map);
  16         if (map == NULL)
  17                 goto err;
  18
  19         memset(map, 0, sizeof(*map));
  20         INIT_LIST_HEAD(&map->list);
  21 err:
  22         return map;
  23 }
  24
  25 static struct maps *alloc_map(void)
  26 {
  27         struct maps *map;
  28
  29         map = malloc(sizeof *map);
  30         if (map == NULL)
  31                 goto err;
  32
  33         memset(map, 0, sizeof(*map));
  34         INIT_LIST_HEAD(&map->list);
  35 err:
  36         return map;
  37 }
  38
  39 static struct maps *parse_maps(FILE *file, int pid, int tid)
  40 {
  41         struct maps *the_map = NULL;
  42         char line[1024];
  43         int ret;
  44
  45         while(fgets(line, sizeof(line), file)) {
  46                 struct maps *map = alloc_map();
  47                 unsigned long start, end;
  48                 char name[1024];
  49
  50                 if (map == NULL)
  51                         return 0;
  52
  53                 if (the_map == NULL)
  54                         the_map = map;
  55
  56                 ret = sscanf(line, "%lx-%lx %*s %*s %*s %*s %s",
  57                              &start, &end, name);
  58
  59                 if (ret < 2) {
  60                         printf("Error reading input: %s\n", line);
  61                         break;
  62                 }
  63
  64                 map->start = start;
  65                 map->end = end;
  66                 map->size = end - start;
  67                 map->pid = pid;
  68                 map->tid = tid;
  69
  70                 if (ret >= 3)
  71                         strncpy(map->name, name, sizeof(map->name));
  72
  73                 list_add_tail(&map->list, &the_map->list);
  74         }
  75
  76         return the_map;
  77 }
  78
  79 static void clear_pageframe(struct pageframe *pf)
  80 {
  81         memset(pf, 0, sizeof(*pf));
  82 }
  83
  84 static struct pageframe *alloc_pageframe(void)
  85 {
  86         struct pageframe *pageframe;
  87
  88         pageframe = malloc(sizeof *pageframe);
  89         if (pageframe == NULL)
  90                 goto err;
  91
  92         clear_pageframe(pageframe);
  93 err:
  94         return pageframe;
  95 }
  96
  97 #define BITRANGE(first, last) (((2ll << (last - first)) - 1) << first)
  98
  99 static void pageframe_to_struct(unsigned long long p, struct pageframe *pf)
 100 {
 101         /* Refer Documentation/vm/pagemap.txt for the format */
 102         pf->page_present = !!(BITRANGE(63, 63) & p);
 103         pf->page_swapped = !!(BITRANGE(62, 62) & p);
 104         pf->page_shift   =   (BITRANGE(55, 60) & p) >> 55;
 105         pf->pfn          =   (BITRANGE(0, 54) & p);
 106         pf->swap_type    =   (BITRANGE(0, 4) & p);
 107         pf->swap_offset  =   (BITRANGE(5, 54) & p) >> 5;
 108 #if 0
 109         printf("pfn: %lx shift: %d present: %d swapped %d\n",
 110                 pf->pfn, pf->page_shift, pf->page_present, pf->page_swapped);
 111 #endif
 112 }
 113
 114 static int compare_pageframe(struct bintree *at, struct bintree *bt)
 115 {
 116         struct pageframe *a, *b;
 117         a = tree_to_pageframe(at);
 118         b = tree_to_pageframe(bt);
 119
 120         return a->pfn - b->pfn;
 121 }
 122
 123 struct bintree_ops pageframe_ops = {
 124         .compare = compare_pageframe,
 125 };
 126
 127 static int check_parse_opts(struct parse_opts *opts, struct pageframe *pf,
 128                 struct maps *map)
 129 {
 130         if (opts->parse_mask & PARSE_PID) {
 131                 if (opts->pid == map->pid)
 132                         return 1;
 133         }
 134
 135         if (opts->parse_mask & PARSE_MAP_NAME) {
 136                 if (!strcmp(opts->map_name, map->name))
 137                         return 1;
 138         }
 139
 140         return 0;
 141 }
 142
 143 /* Read data from the /proc/pid/pagemap file */
 144 static int parse_pageframe(FILE *file, struct pageframe *pf_tree,
 145                         struct maps *maps, struct parse_opts *opts)
 146 {
 147         struct maps *map;
 148         struct maps_list *tmp;
 149         struct pageframe *match, *pageframe = NULL;
 150         long start, len, i;
 151         unsigned long long pf[10240];
 152         int ret, error;
 153
 154         if (maps == NULL)
 155                 return 0;
 156
 157         /* Go through the list of allocated memory areas */
 158         list_for_each_entry(map, &maps->list, list) {
 159                 start = map->start >> (PAGE_SHIFT - 3);
 160                 len = map->size >> (PAGE_SHIFT - 3);
 161
 162                 ret = fseek(file, start, SEEK_SET);
 163                 if (ret) {
 164                         error = errno;
 165                         fprintf(stderr, "Error seeking to %lx: %s\n", start,
 166                                 strerror(error));
 167                         continue;
 168                 }
 169
 170                 for (i = 0; i < len; i++) {
 171                         if (!ret) {
 172                                 ret = fread(&pf, 1,
 173                                         MIN(sizeof(pf), (len - i) * 8), file);
 174                         }
 175                         if (ret < 0) {
 176                                 error = errno;
 177                                 continue;
 178                         }
 179                         if (!pageframe)
 180                                 pageframe = alloc_pageframe();
 181                         ret -= sizeof(pf[0]);
 182
 183                         /* ignore unused pages */
 184                         if (!pf[ret / sizeof(pf[0])])
 185                                 continue;
 186
 187                         pageframe_to_struct(pf[ret / sizeof(pf[0])], pageframe);
 188
 189                         /* ignore unused pages */
 190                         if (!(pageframe->page_swapped ||
 191                                         pageframe->page_present))
 192                                 continue;
 193
 194                         if (check_parse_opts(opts, pageframe, map)) {
 195                                 match = tree_to_pageframe(
 196                                         bintree_add(&pf_tree->tree,
 197                                                 &pageframe->tree,
 198                                                 &pageframe_ops));
 199                         } else {
 200                                 match = tree_to_pageframe(
 201                                         bintree_find(&pf_tree->tree,
 202                                                 &pageframe->tree,
 203                                                 &pageframe_ops));
 204                         }
 205
 206                         if (match == NULL)
 207                                 continue;
 208
 209                         if (match == pageframe)
 210                                 pageframe = NULL;
 211
 212                         match->refcount++;
 213                         /*
 214                          * Add a link from the physical page to this
 215                          * process's page map
 216                          */
 217                         if (!match->ml) {
 218                                 match->ml = alloc_maplist();
 219                                 match->ml->map = map;
 220                         } else {
 221                                 tmp = alloc_maplist();
 222                                 tmp->map = map;
 223                                 list_add(&match->ml->list, &tmp->list);
 224                         }
 225
 226                         if (match->page_present) {
 227                                 map->pages_present++;
 228                         } else if (match->page_swapped) {
 229                                 map->pages_swapped++;
 230                         }
 231                 }
 232         }
 233
 234         return 0;
 235 }
 236
 237 void read_pageframe(int pid, int tid, struct pageframe *pageframe,
 238                 struct process **process_list, struct parse_opts *opts)
 239 {
 240         struct maps *maps;
 241         struct process *process;
 242         FILE *file;
 243         char path[512];
 244         int ret;
 245
 246         process = malloc(sizeof(*process));
 247         memset(process, 0, sizeof(*process));
 248         INIT_LIST_HEAD(&process->list);
 249
 250         if (*process_list == NULL)
 251                 *process_list = process;
 252
 253         process->pid = pid;
 254         process->tid = tid;
 255
 256         list_add_tail(&process->list, &(*process_list)->list);
 257
 258         snprintf(path, sizeof(path), "/proc/%d/task/%d/maps", pid, tid);
 259         file = fopen(path, "rb");
 260
 261         if (!file)
 262                 return;
 263
 264         maps = parse_maps(file, pid, tid);
 265         fclose(file);
 266         process->maps = maps;
 267
 268         snprintf(path, sizeof(path), "/proc/%d/task/%d/pagemap", pid, tid);
 269         file = fopen(path, "rb");
 270
 271         if (!file)
 272                 return;
 273
 274         parse_pageframe(file, pageframe, maps, opts);
 275         fclose(file);
 276
 277         snprintf(path, sizeof(path), "/proc/%d/task/%d/cmdline", pid, tid);
 278         file = fopen(path, "rb");
 279
 280         if (!file)
 281                 return;
 282
 283         ret = fread(process->name, 1, sizeof(process->name), file);
 284         if (ret > 0)
 285                 process->name[ret - 1] = 0;
 286         fclose(file);
 287
 288         if (maps == NULL)
 289                 return;
 290
 291         list_for_each_entry(maps, &process->maps->list, list) {
 292                 process->pages_present += maps->pages_present;
 293                 process->pages_swapped += maps->pages_swapped;
 294         }
 295
 296         return;
 297 }
 298
 299 static int parse_pid(DIR **dir)
 300 {
 301         struct dirent *dirent;
 302         int error;
 303
 304 restart:
 305         dirent = readdir(*dir);
 306         if (!dirent) {
 307                 if (errno == 0) {
 308                         closedir(*dir);
 309                         *dir = NULL;
 310                         return 0;
 311                 }
 312                 error = errno;
 313                 printf("Failed to read /proc directory: %s\n", strerror(error));
 314                 return -1;
 315         }
 316
 317         if (dirent->d_name[0] < '0' || dirent->d_name[0] > '9')
 318                 goto restart;
 319
 320         return atoi(dirent->d_name);
 321 }
 322
 323 static int get_next_tid(int pid, DIR **dir)
 324 {
 325         int error;
 326
 327         if (*dir == NULL) {
 328                 char path[64];
 329
 330                 snprintf(path, sizeof(path), "/proc/%d/task/", pid);
 331                 *dir = opendir(path);
 332                 if (!*dir) {
 333                         error = errno;
 334                         printf("Failed to open %s directory: %s\n",
 335                                 path,
 336                                 strerror(error));
 337                         return -1;
 338                 }
 339         }
 340
 341         return parse_pid(dir);
 342 }
 343
 344 static int get_next_pid(void)
 345 {
 346         static DIR *dir = NULL;
 347         int error;
 348
 349         if (!dir) {
 350                 dir = opendir("/proc");
 351                 if (!dir) {
 352                         error = errno;
 353                         printf("Failed to open /proc directory: %s\n",
 354                                 strerror(error));
 355                         return -1;
 356                 }
 357         }
 358
 359         return parse_pid(&dir);
 360 }
 361
 362 static void read_pageframe_with_threads(int pid,
 363                                         struct pageframe *pageframe,
 364                                         struct process **process_list,
 365                                         struct parse_opts *opts)
 366 {
 367         DIR *dir = NULL;
 368         int tid;
 369
 370         while (1) {
 371                 if (opts->with_threads)
 372                         tid = get_next_tid(pid, &dir);
 373                 else
 374                         tid = pid;
 375
 376                 if (tid <= 0)
 377                         return;
 378
 379                 read_pageframe(pid, tid, pageframe, process_list, opts);
 380
 381                 if (!opts->with_threads)
 382                         break;
 383         }
 384 }
 385
 386 void scan_all_pids(struct pageframe *pf, struct process **process_list,
 387                 struct parse_opts *opts)
 388 {
 389         int pid;
 390
 391         if (opts->parse_mask & PARSE_PID)
 392                 read_pageframe_with_threads(opts->pid, pf, process_list, opts);
 393
 394         while(1) {
 395                 pid = get_next_pid();
 396                 if (pid <= 0)
 397                         break;
 398                 read_pageframe_with_threads(pid, pf, process_list, opts);
 399         }
 400 }