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)
  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
  69                 if (ret >= 3)
  70                         strncpy(map->name, name, sizeof(map->name));
  71
  72                 list_add_tail(&map->list, &the_map->list);
  73         }
  74
  75         return the_map;
  76 }
  77
  78 static void clear_pageframe(struct pageframe *pf)
  79 {
  80         memset(pf, 0, sizeof(*pf));
  81 }
  82
  83 static struct pageframe *alloc_pageframe(void)
  84 {
  85         struct pageframe *pageframe;
  86
  87         pageframe = malloc(sizeof *pageframe);
  88         if (pageframe == NULL)
  89                 goto err;
  90
  91         clear_pageframe(pageframe);
  92 err:
  93         return pageframe;
  94 }
  95
  96 #define BITRANGE(first, last) (((2ll << (last - first)) - 1) << first)
  97
  98 static void pageframe_to_struct(unsigned long long p, struct pageframe *pf)
  99 {
 100         pf->page_present = !!(BITRANGE(63, 63) & p);
 101         pf->page_swapped = !!(BITRANGE(62, 62) & p);
 102         pf->page_shift   =   (BITRANGE(55, 60) & p) >> 55;
 103         pf->pfn          =   (BITRANGE(0, 54) & p);
 104         pf->swap_type    =   (BITRANGE(0, 4) & p);
 105         pf->swap_offset  =   (BITRANGE(5, 54) & p) >> 5;
 106 #if 0
 107         printf("pfn: %lx shift: %d present: %d swapped %d\n",
 108                 pf->pfn, pf->page_shift, pf->page_present, pf->page_swapped);
 109 #endif
 110 }
 111
 112 static int compare_pageframe(struct bintree *at, struct bintree *bt)
 113 {
 114         struct pageframe *a, *b;
 115         a = tree_to_pageframe(at);
 116         b = tree_to_pageframe(bt);
 117
 118         return a->pfn - b->pfn;
 119 }
 120
 121 struct bintree_ops pageframe_ops = {
 122         .compare = compare_pageframe,
 123 };
 124
 125 /* Read data from the /proc/pid/pagemap file */
 126 static int parse_pageframe(FILE *file, struct pageframe *pf_tree,
 127                         struct maps *maps, int add_to_tree)
 128 {
 129         struct maps *map;
 130         struct maps_list *tmp;
 131         struct pageframe *match, *pageframe = NULL;
 132         long start, len, i;
 133         unsigned long long pf;
 134         int ret, error;
 135
 136         /* Go through the list of allocated memory areas */
 137         list_for_each_entry(map, &maps->list, list) {
 138                 start = map->start >> (PAGE_SHIFT - 3);
 139                 len = map->size >> (PAGE_SHIFT - 3);
 140
 141                 ret = fseek(file, start, SEEK_SET);
 142                 if (ret) {
 143                         error = errno;
 144                         fprintf(stderr, "Error seeking to %lx: %s\n", start,
 145                                 strerror(error));
 146                         continue;
 147                 }
 148
 149                 for (i = 0; i < len; i++) {
 150                         ret = fread(&pf, 1, sizeof(pf), file);
 151                         if (ret != sizeof(pf)) {
 152                                 error = errno;
 153                                 continue;
 154                         }
 155                         if (!pageframe)
 156                                 pageframe = alloc_pageframe();
 157
 158                         pageframe_to_struct(pf, pageframe);
 159
 160                         if (add_to_tree) {
 161                                 match = tree_to_pageframe(
 162                                         bintree_add(&pf_tree->tree,
 163                                                 &pageframe->tree,
 164                                                 &pageframe_ops));
 165                         } else {
 166                                 match = tree_to_pageframe(
 167                                         bintree_find(&pf_tree->tree,
 168                                                 &pageframe->tree,
 169                                                 &pageframe_ops));
 170                         }
 171
 172                         if (match == NULL)
 173                                 continue;
 174
 175                         if (match == pageframe)
 176                                 pageframe = NULL;
 177
 178                         match->refcount++;
 179                         /*
 180                          * Add a link from the physical page to this
 181                          * process's page map
 182                          */
 183                         if (!match->ml) {
 184                                 match->ml = alloc_maplist();
 185                                 match->ml->map = map;
 186                         } else {
 187                                 tmp = alloc_maplist();
 188                                 tmp->map = map;
 189                                 list_add(&match->ml->list, &tmp->list);
 190                         }
 191
 192                         if (match->page_present) {
 193                                 map->pages_present++;
 194                         } else if (match->page_swapped) {
 195                                 map->pages_swapped++;
 196                         }
 197                 }
 198         }
 199
 200         return 0;
 201 }
 202
 203 void read_pageframe(int pid, struct pageframe *pageframe, int add_to_tree)
 204 {
 205         struct maps *maps;
 206         FILE *file;
 207         char path[512];
 208
 209         snprintf(path, sizeof(path), "/proc/%d/maps", pid);
 210         file = fopen(path, "rb");
 211
 212         if (!file)
 213                 return;
 214
 215         maps = parse_maps(file, pid);
 216         fclose(file);
 217
 218         snprintf(path, sizeof(path), "/proc/%d/pagemap", pid);
 219         file = fopen(path, "rb");
 220
 221         if (!file)
 222                 return;
 223
 224         parse_pageframe(file, pageframe, maps, add_to_tree);
 225         fclose(file);
 226
 227         return;
 228 }
 229
 230 static int get_next_pid(void)
 231 {
 232         static DIR *dir = NULL;
 233         struct dirent *dirent;
 234         int error;
 235
 236         if (!dir) {
 237                 dir = opendir("/proc");
 238                 if (!dir) {
 239                         error = errno;
 240                         printf("Failed to open /proc directory: %s\n",
 241                                 strerror(error));
 242                         return -1;
 243                 }
 244         }
 245
 246 restart:
 247         dirent = readdir(dir);
 248         if (!dirent) {
 249                 if (errno == 0) {
 250                         closedir(dir);
 251                         dir = NULL;
 252                         return 0;
 253                 }
 254                 error = errno;
 255                 printf("Failed to read /proc directory: %s\n", strerror(error));
 256                 return -1;
 257         }
 258
 259         printf("%s\n", dirent->d_name);
 260         if (dirent->d_name[0] < '0' || dirent->d_name[0] > '9')
 261                 goto restart;
 262
 263         return atoi(dirent->d_name);
 264 }
 265
 266 void scan_all_pids(struct pageframe *pf, int interesting_pid)
 267 {
 268         int pid;
 269
 270         read_pageframe(interesting_pid, pf, 1);
 271
 272         while(1) {
 273                 pid = get_next_pid();
 274                 if (pid <= 0)
 275                         break;
 276                 read_pageframe(pid, pf, 0);
 277         }
 278 }