Documentation/vm/page-types.c

   1 /*
   2  * page-types: Tool for querying page flags
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; version 2.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should find a copy of v2 of the GNU General Public License somewhere on
  14  * your Linux system; if not, write to the Free Software Foundation, Inc., 59
  15  * Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Copyright (C) 2009 Intel corporation
  18  *
  19  * Authors: Wu Fengguang <fengguang.wu@intel.com>
  20  */
  21
  22 #define _LARGEFILE64_SOURCE
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <stdint.h>
  27 #include <stdarg.h>
  28 #include <string.h>
  29 #include <getopt.h>
  30 #include <limits.h>
  31 #include <assert.h>
  32 #include <sys/types.h>
  33 #include <sys/errno.h>
  34 #include <sys/fcntl.h>
  35 #include <sys/mount.h>
  36 #include <sys/statfs.h>
  37 #include "../../include/linux/magic.h"
  38
  39
  40 #ifndef MAX_PATH
  41 # define MAX_PATH 256
  42 #endif
  43
  44 #ifndef STR
  45 # define _STR(x) #x
  46 # define STR(x) _STR(x)
  47 #endif
  48
  49 /*
  50  * pagemap kernel ABI bits
  51  */
  52
  53 #define PM_ENTRY_BYTES      sizeof(uint64_t)
  54 #define PM_STATUS_BITS      3
  55 #define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
  56 #define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
  57 #define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
  58 #define PM_PSHIFT_BITS      6
  59 #define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
  60 #define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
  61 #define PM_PSHIFT(x)        (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
  62 #define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
  63 #define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
  64
  65 #define PM_PRESENT          PM_STATUS(4LL)
  66 #define PM_SWAP             PM_STATUS(2LL)
  67
  68
  69 /*
  70  * kernel page flags
  71  */
  72
  73 #define KPF_BYTES               8
  74 #define PROC_KPAGEFLAGS         "/proc/kpageflags"
  75
  76 /* copied from kpageflags_read() */
  77 #define KPF_LOCKED              0
  78 #define KPF_ERROR               1
  79 #define KPF_REFERENCED          2
  80 #define KPF_UPTODATE            3
  81 #define KPF_DIRTY               4
  82 #define KPF_LRU                 5
  83 #define KPF_ACTIVE              6
  84 #define KPF_SLAB                7
  85 #define KPF_WRITEBACK           8
  86 #define KPF_RECLAIM             9
  87 #define KPF_BUDDY               10
  88
  89 /* [11-20] new additions in 2.6.31 */
  90 #define KPF_MMAP                11
  91 #define KPF_ANON                12
  92 #define KPF_SWAPCACHE           13
  93 #define KPF_SWAPBACKED          14
  94 #define KPF_COMPOUND_HEAD       15
  95 #define KPF_COMPOUND_TAIL       16
  96 #define KPF_HUGE                17
  97 #define KPF_UNEVICTABLE         18
  98 #define KPF_HWPOISON            19
  99 #define KPF_NOPAGE              20
 100 #define KPF_KSM                 21
 101
 102 /* [32-] kernel hacking assistances */
 103 #define KPF_RESERVED            32
 104 #define KPF_MLOCKED             33
 105 #define KPF_MAPPEDTODISK        34
 106 #define KPF_PRIVATE             35
 107 #define KPF_PRIVATE_2           36
 108 #define KPF_OWNER_PRIVATE       37
 109 #define KPF_ARCH                38
 110 #define KPF_UNCACHED            39
 111
 112 /* [48-] take some arbitrary free slots for expanding overloaded flags
 113  * not part of kernel API
 114  */
 115 #define KPF_READAHEAD           48
 116 #define KPF_SLOB_FREE           49
 117 #define KPF_SLUB_FROZEN         50
 118 #define KPF_SLUB_DEBUG          51
 119
 120 #define KPF_ALL_BITS            ((uint64_t)~0ULL)
 121 #define KPF_HACKERS_BITS        (0xffffULL << 32)
 122 #define KPF_OVERLOADED_BITS     (0xffffULL << 48)
 123 #define BIT(name)               (1ULL << KPF_##name)
 124 #define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
 125
 126 static const char *page_flag_names[] = {
 127         [KPF_LOCKED]            = "L:locked",
 128         [KPF_ERROR]             = "E:error",
 129         [KPF_REFERENCED]        = "R:referenced",
 130         [KPF_UPTODATE]          = "U:uptodate",
 131         [KPF_DIRTY]             = "D:dirty",
 132         [KPF_LRU]               = "l:lru",
 133         [KPF_ACTIVE]            = "A:active",
 134         [KPF_SLAB]              = "S:slab",
 135         [KPF_WRITEBACK]         = "W:writeback",
 136         [KPF_RECLAIM]           = "I:reclaim",
 137         [KPF_BUDDY]             = "B:buddy",
 138
 139         [KPF_MMAP]              = "M:mmap",
 140         [KPF_ANON]              = "a:anonymous",
 141         [KPF_SWAPCACHE]         = "s:swapcache",
 142         [KPF_SWAPBACKED]        = "b:swapbacked",
 143         [KPF_COMPOUND_HEAD]     = "H:compound_head",
 144         [KPF_COMPOUND_TAIL]     = "T:compound_tail",
 145         [KPF_HUGE]              = "G:huge",
 146         [KPF_UNEVICTABLE]       = "u:unevictable",
 147         [KPF_HWPOISON]          = "X:hwpoison",
 148         [KPF_NOPAGE]            = "n:nopage",
 149         [KPF_KSM]               = "x:ksm",
 150
 151         [KPF_RESERVED]          = "r:reserved",
 152         [KPF_MLOCKED]           = "m:mlocked",
 153         [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
 154         [KPF_PRIVATE]           = "P:private",
 155         [KPF_PRIVATE_2]         = "p:private_2",
 156         [KPF_OWNER_PRIVATE]     = "O:owner_private",
 157         [KPF_ARCH]              = "h:arch",
 158         [KPF_UNCACHED]          = "c:uncached",
 159
 160         [KPF_READAHEAD]         = "I:readahead",
 161         [KPF_SLOB_FREE]         = "P:slob_free",
 162         [KPF_SLUB_FROZEN]       = "A:slub_frozen",
 163         [KPF_SLUB_DEBUG]        = "E:slub_debug",
 164 };
 165
 166
 167 static const char *debugfs_known_mountpoints[] = {
 168         "/sys/kernel/debug",
 169         "/debug",
 170         0,
 171 };
 172
 173 /*
 174  * data structures
 175  */
 176
 177 static int              opt_raw;        /* for kernel developers */
 178 static int              opt_list;       /* list pages (in ranges) */
 179 static int              opt_no_summary; /* don't show summary */
 180 static pid_t            opt_pid;        /* process to walk */
 181
 182 #define MAX_ADDR_RANGES 1024
 183 static int              nr_addr_ranges;
 184 static unsigned long    opt_offset[MAX_ADDR_RANGES];
 185 static unsigned long    opt_size[MAX_ADDR_RANGES];
 186
 187 #define MAX_VMAS        10240
 188 static int              nr_vmas;
 189 static unsigned long    pg_start[MAX_VMAS];
 190 static unsigned long    pg_end[MAX_VMAS];
 191
 192 #define MAX_BIT_FILTERS 64
 193 static int              nr_bit_filters;
 194 static uint64_t         opt_mask[MAX_BIT_FILTERS];
 195 static uint64_t         opt_bits[MAX_BIT_FILTERS];
 196
 197 static int              page_size;
 198
 199 static int              pagemap_fd;
 200 static int              kpageflags_fd;
 201
 202 static int              opt_hwpoison;
 203 static int              opt_unpoison;
 204
 205 static char             hwpoison_debug_fs[MAX_PATH+1];
 206 static int              hwpoison_inject_fd;
 207 static int              hwpoison_forget_fd;
 208
 209 #define HASH_SHIFT      13
 210 #define HASH_SIZE       (1 << HASH_SHIFT)
 211 #define HASH_MASK       (HASH_SIZE - 1)
 212 #define HASH_KEY(flags) (flags & HASH_MASK)
 213
 214 static unsigned long    total_pages;
 215 static unsigned long    nr_pages[HASH_SIZE];
 216 static uint64_t         page_flags[HASH_SIZE];
 217
 218
 219 /*
 220  * helper functions
 221  */
 222
 223 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 224
 225 #define min_t(type, x, y) ({                    \
 226         type __min1 = (x);                      \
 227         type __min2 = (y);                      \
 228         __min1 < __min2 ? __min1 : __min2; })
 229
 230 #define max_t(type, x, y) ({                    \
 231         type __max1 = (x);                      \
 232         type __max2 = (y);                      \
 233         __max1 > __max2 ? __max1 : __max2; })
 234
 235 static unsigned long pages2mb(unsigned long pages)
 236 {
 237         return (pages * page_size) >> 20;
 238 }
 239
 240 static void fatal(const char *x, ...)
 241 {
 242         va_list ap;
 243
 244         va_start(ap, x);
 245         vfprintf(stderr, x, ap);
 246         va_end(ap);
 247         exit(EXIT_FAILURE);
 248 }
 249
 250 static int checked_open(const char *pathname, int flags)
 251 {
 252         int fd = open(pathname, flags);
 253
 254         if (fd < 0) {
 255                 perror(pathname);
 256                 exit(EXIT_FAILURE);
 257         }
 258
 259         return fd;
 260 }
 261
 262 /*
 263  * pagemap/kpageflags routines
 264  */
 265
 266 static unsigned long do_u64_read(int fd, char *name,
 267                                  uint64_t *buf,
 268                                  unsigned long index,
 269                                  unsigned long count)
 270 {
 271         long bytes;
 272
 273         if (index > ULONG_MAX / 8)
 274                 fatal("index overflow: %lu\n", index);
 275
 276         if (lseek(fd, index * 8, SEEK_SET) < 0) {
 277                 perror(name);
 278                 exit(EXIT_FAILURE);
 279         }
 280
 281         bytes = read(fd, buf, count * 8);
 282         if (bytes < 0) {
 283                 perror(name);
 284                 exit(EXIT_FAILURE);
 285         }
 286         if (bytes % 8)
 287                 fatal("partial read: %lu bytes\n", bytes);
 288
 289         return bytes / 8;
 290 }
 291
 292 static unsigned long kpageflags_read(uint64_t *buf,
 293                                      unsigned long index,
 294                                      unsigned long pages)
 295 {
 296         return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
 297 }
 298
 299 static unsigned long pagemap_read(uint64_t *buf,
 300                                   unsigned long index,
 301                                   unsigned long pages)
 302 {
 303         return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
 304 }
 305
 306 static unsigned long pagemap_pfn(uint64_t val)
 307 {
 308         unsigned long pfn;
 309
 310         if (val & PM_PRESENT)
 311                 pfn = PM_PFRAME(val);
 312         else
 313                 pfn = 0;
 314
 315         return pfn;
 316 }
 317
 318
 319 /*
 320  * page flag names
 321  */
 322
 323 static char *page_flag_name(uint64_t flags)
 324 {
 325         static char buf[65];
 326         int present;
 327         int i, j;
 328
 329         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 330                 present = (flags >> i) & 1;
 331                 if (!page_flag_names[i]) {
 332                         if (present)
 333                                 fatal("unknown flag bit %d\n", i);
 334                         continue;
 335                 }
 336                 buf[j++] = present ? page_flag_names[i][0] : '_';
 337         }
 338
 339         return buf;
 340 }
 341
 342 static char *page_flag_longname(uint64_t flags)
 343 {
 344         static char buf[1024];
 345         int i, n;
 346
 347         for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 348                 if (!page_flag_names[i])
 349                         continue;
 350                 if ((flags >> i) & 1)
 351                         n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 352                                         page_flag_names[i] + 2);
 353         }
 354         if (n)
 355                 n--;
 356         buf[n] = '\0';
 357
 358         return buf;
 359 }
 360
 361
 362 /*
 363  * page list and summary
 364  */
 365
 366 static void show_page_range(unsigned long voffset,
 367                             unsigned long offset, uint64_t flags)
 368 {
 369         static uint64_t      flags0;
 370         static unsigned long voff;
 371         static unsigned long index;
 372         static unsigned long count;
 373
 374         if (flags == flags0 && offset == index + count &&
 375             (!opt_pid || voffset == voff + count)) {
 376                 count++;
 377                 return;
 378         }
 379
 380         if (count) {
 381                 if (opt_pid)
 382                         printf("%lx\t", voff);
 383                 printf("%lx\t%lx\t%s\n",
 384                                 index, count, page_flag_name(flags0));
 385         }
 386
 387         flags0 = flags;
 388         index  = offset;
 389         voff   = voffset;
 390         count  = 1;
 391 }
 392
 393 static void show_page(unsigned long voffset,
 394                       unsigned long offset, uint64_t flags)
 395 {
 396         if (opt_pid)
 397                 printf("%lx\t", voffset);
 398         printf("%lx\t%s\n", offset, page_flag_name(flags));
 399 }
 400
 401 static void show_summary(void)
 402 {
 403         int i;
 404
 405         printf("             flags\tpage-count       MB"
 406                 "  symbolic-flags\t\t\tlong-symbolic-flags\n");
 407
 408         for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 409                 if (nr_pages[i])
 410                         printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 411                                 (unsigned long long)page_flags[i],
 412                                 nr_pages[i],
 413                                 pages2mb(nr_pages[i]),
 414                                 page_flag_name(page_flags[i]),
 415                                 page_flag_longname(page_flags[i]));
 416         }
 417
 418         printf("             total\t%10lu %8lu\n",
 419                         total_pages, pages2mb(total_pages));
 420 }
 421
 422
 423 /*
 424  * page flag filters
 425  */
 426
 427 static int bit_mask_ok(uint64_t flags)
 428 {
 429         int i;
 430
 431         for (i = 0; i < nr_bit_filters; i++) {
 432                 if (opt_bits[i] == KPF_ALL_BITS) {
 433                         if ((flags & opt_mask[i]) == 0)
 434                                 return 0;
 435                 } else {
 436                         if ((flags & opt_mask[i]) != opt_bits[i])
 437                                 return 0;
 438                 }
 439         }
 440
 441         return 1;
 442 }
 443
 444 static uint64_t expand_overloaded_flags(uint64_t flags)
 445 {
 446         /* SLOB/SLUB overload several page flags */
 447         if (flags & BIT(SLAB)) {
 448                 if (flags & BIT(PRIVATE))
 449                         flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 450                 if (flags & BIT(ACTIVE))
 451                         flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 452                 if (flags & BIT(ERROR))
 453                         flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 454         }
 455
 456         /* PG_reclaim is overloaded as PG_readahead in the read path */
 457         if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 458                 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 459
 460         return flags;
 461 }
 462
 463 static uint64_t well_known_flags(uint64_t flags)
 464 {
 465         /* hide flags intended only for kernel hacker */
 466         flags &= ~KPF_HACKERS_BITS;
 467
 468         /* hide non-hugeTLB compound pages */
 469         if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 470                 flags &= ~BITS_COMPOUND;
 471
 472         return flags;
 473 }
 474
 475 static uint64_t kpageflags_flags(uint64_t flags)
 476 {
 477         flags = expand_overloaded_flags(flags);
 478
 479         if (!opt_raw)
 480                 flags = well_known_flags(flags);
 481
 482         return flags;
 483 }
 484
 485 /* verify that a mountpoint is actually a debugfs instance */
 486 static int debugfs_valid_mountpoint(const char *debugfs)
 487 {
 488         struct statfs st_fs;
 489
 490         if (statfs(debugfs, &st_fs) < 0)
 491                 return -ENOENT;
 492         else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
 493                 return -ENOENT;
 494
 495         return 0;
 496 }
 497
 498 /* find the path to the mounted debugfs */
 499 static const char *debugfs_find_mountpoint(void)
 500 {
 501         const char **ptr;
 502         char type[100];
 503         FILE *fp;
 504
 505         ptr = debugfs_known_mountpoints;
 506         while (*ptr) {
 507                 if (debugfs_valid_mountpoint(*ptr) == 0) {
 508                         strcpy(hwpoison_debug_fs, *ptr);
 509                         return hwpoison_debug_fs;
 510                 }
 511                 ptr++;
 512         }
 513
 514         /* give up and parse /proc/mounts */
 515         fp = fopen("/proc/mounts", "r");
 516         if (fp == NULL)
 517                 perror("Can't open /proc/mounts for read");
 518
 519         while (fscanf(fp, "%*s %"
 520                       STR(MAX_PATH)
 521                       "s %99s %*s %*d %*d\n",
 522                       hwpoison_debug_fs, type) == 2) {
 523                 if (strcmp(type, "debugfs") == 0)
 524                         break;
 525         }
 526         fclose(fp);
 527
 528         if (strcmp(type, "debugfs") != 0)
 529                 return NULL;
 530
 531         return hwpoison_debug_fs;
 532 }
 533
 534 /* mount the debugfs somewhere if it's not mounted */
 535
 536 static void debugfs_mount(void)
 537 {
 538         const char **ptr;
 539
 540         /* see if it's already mounted */
 541         if (debugfs_find_mountpoint())
 542                 return;
 543
 544         ptr = debugfs_known_mountpoints;
 545         while (*ptr) {
 546                 if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
 547                         /* save the mountpoint */
 548                         strcpy(hwpoison_debug_fs, *ptr);
 549                         break;
 550                 }
 551                 ptr++;
 552         }
 553
 554         if (*ptr == NULL) {
 555                 perror("mount debugfs");
 556                 exit(EXIT_FAILURE);
 557         }
 558 }
 559
 560 /*
 561  * page actions
 562  */
 563
 564 static void prepare_hwpoison_fd(void)
 565 {
 566         char buf[MAX_PATH + 1];
 567
 568         debugfs_mount();
 569
 570         if (opt_hwpoison && !hwpoison_inject_fd) {
 571                 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 572                         hwpoison_debug_fs);
 573                 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 574         }
 575
 576         if (opt_unpoison && !hwpoison_forget_fd) {
 577                 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 578                         hwpoison_debug_fs);
 579                 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 580         }
 581 }
 582
 583 static int hwpoison_page(unsigned long offset)
 584 {
 585         char buf[100];
 586         int len;
 587
 588         len = sprintf(buf, "0x%lx\n", offset);
 589         len = write(hwpoison_inject_fd, buf, len);
 590         if (len < 0) {
 591                 perror("hwpoison inject");
 592                 return len;
 593         }
 594         return 0;
 595 }
 596
 597 static int unpoison_page(unsigned long offset)
 598 {
 599         char buf[100];
 600         int len;
 601
 602         len = sprintf(buf, "0x%lx\n", offset);
 603         len = write(hwpoison_forget_fd, buf, len);
 604         if (len < 0) {
 605                 perror("hwpoison forget");
 606                 return len;
 607         }
 608         return 0;
 609 }
 610
 611 /*
 612  * page frame walker
 613  */
 614
 615 static int hash_slot(uint64_t flags)
 616 {
 617         int k = HASH_KEY(flags);
 618         int i;
 619
 620         /* Explicitly reserve slot 0 for flags 0: the following logic
 621          * cannot distinguish an unoccupied slot from slot (flags==0).
 622          */
 623         if (flags == 0)
 624                 return 0;
 625
 626         /* search through the remaining (HASH_SIZE-1) slots */
 627         for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 628                 if (!k || k >= ARRAY_SIZE(page_flags))
 629                         k = 1;
 630                 if (page_flags[k] == 0) {
 631                         page_flags[k] = flags;
 632                         return k;
 633                 }
 634                 if (page_flags[k] == flags)
 635                         return k;
 636         }
 637
 638         fatal("hash table full: bump up HASH_SHIFT?\n");
 639         exit(EXIT_FAILURE);
 640 }
 641
 642 static void add_page(unsigned long voffset,
 643                      unsigned long offset, uint64_t flags)
 644 {
 645         flags = kpageflags_flags(flags);
 646
 647         if (!bit_mask_ok(flags))
 648                 return;
 649
 650         if (opt_hwpoison)
 651                 hwpoison_page(offset);
 652         if (opt_unpoison)
 653                 unpoison_page(offset);
 654
 655         if (opt_list == 1)
 656                 show_page_range(voffset, offset, flags);
 657         else if (opt_list == 2)
 658                 show_page(voffset, offset, flags);
 659
 660         nr_pages[hash_slot(flags)]++;
 661         total_pages++;
 662 }
 663
 664 #define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 665 static void walk_pfn(unsigned long voffset,
 666                      unsigned long index,
 667                      unsigned long count)
 668 {
 669         uint64_t buf[KPAGEFLAGS_BATCH];
 670         unsigned long batch;
 671         long pages;
 672         unsigned long i;
 673
 674         while (count) {
 675                 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 676                 pages = kpageflags_read(buf, index, batch);
 677                 if (pages == 0)
 678                         break;
 679
 680                 for (i = 0; i < pages; i++)
 681                         add_page(voffset + i, index + i, buf[i]);
 682
 683                 index += pages;
 684                 count -= pages;
 685         }
 686 }
 687
 688 #define PAGEMAP_BATCH   (64 << 10)
 689 static void walk_vma(unsigned long index, unsigned long count)
 690 {
 691         uint64_t buf[PAGEMAP_BATCH];
 692         unsigned long batch;
 693         unsigned long pages;
 694         unsigned long pfn;
 695         unsigned long i;
 696
 697         while (count) {
 698                 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 699                 pages = pagemap_read(buf, index, batch);
 700                 if (pages == 0)
 701                         break;
 702
 703                 for (i = 0; i < pages; i++) {
 704                         pfn = pagemap_pfn(buf[i]);
 705                         if (pfn)
 706                                 walk_pfn(index + i, pfn, 1);
 707                 }
 708
 709                 index += pages;
 710                 count -= pages;
 711         }
 712 }
 713
 714 static void walk_task(unsigned long index, unsigned long count)
 715 {
 716         const unsigned long end = index + count;
 717         unsigned long start;
 718         int i = 0;
 719
 720         while (index < end) {
 721
 722                 while (pg_end[i] <= index)
 723                         if (++i >= nr_vmas)
 724                                 return;
 725                 if (pg_start[i] >= end)
 726                         return;
 727
 728                 start = max_t(unsigned long, pg_start[i], index);
 729                 index = min_t(unsigned long, pg_end[i], end);
 730
 731                 assert(start < index);
 732                 walk_vma(start, index - start);
 733         }
 734 }
 735
 736 static void add_addr_range(unsigned long offset, unsigned long size)
 737 {
 738         if (nr_addr_ranges >= MAX_ADDR_RANGES)
 739                 fatal("too many addr ranges\n");
 740
 741         opt_offset[nr_addr_ranges] = offset;
 742         opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 743         nr_addr_ranges++;
 744 }
 745
 746 static void walk_addr_ranges(void)
 747 {
 748         int i;
 749
 750         kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 751
 752         if (!nr_addr_ranges)
 753                 add_addr_range(0, ULONG_MAX);
 754
 755         for (i = 0; i < nr_addr_ranges; i++)
 756                 if (!opt_pid)
 757                         walk_pfn(0, opt_offset[i], opt_size[i]);
 758                 else
 759                         walk_task(opt_offset[i], opt_size[i]);
 760
 761         close(kpageflags_fd);
 762 }
 763
 764
 765 /*
 766  * user interface
 767  */
 768
 769 static const char *page_flag_type(uint64_t flag)
 770 {
 771         if (flag & KPF_HACKERS_BITS)
 772                 return "(r)";
 773         if (flag & KPF_OVERLOADED_BITS)
 774                 return "(o)";
 775         return "   ";
 776 }
 777
 778 static void usage(void)
 779 {
 780         int i, j;
 781
 782         printf(
 783 "page-types [options]\n"
 784 "            -r|--raw                   Raw mode, for kernel developers\n"
 785 "            -d|--describe flags        Describe flags\n"
 786 "            -a|--addr    addr-spec     Walk a range of pages\n"
 787 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
 788 "            -p|--pid     pid           Walk process address space\n"
 789 #if 0 /* planned features */
 790 "            -f|--file    filename      Walk file address space\n"
 791 #endif
 792 "            -l|--list                  Show page details in ranges\n"
 793 "            -L|--list-each             Show page details one by one\n"
 794 "            -N|--no-summary            Don't show summary info\n"
 795 "            -X|--hwpoison              hwpoison pages\n"
 796 "            -x|--unpoison              unpoison pages\n"
 797 "            -h|--help                  Show this usage message\n"
 798 "flags:\n"
 799 "            0x10                       bitfield format, e.g.\n"
 800 "            anon                       bit-name, e.g.\n"
 801 "            0x10,anon                  comma-separated list, e.g.\n"
 802 "addr-spec:\n"
 803 "            N                          one page at offset N (unit: pages)\n"
 804 "            N+M                        pages range from N to N+M-1\n"
 805 "            N,M                        pages range from N to M-1\n"
 806 "            N,                         pages range from N to end\n"
 807 "            ,M                         pages range from 0 to M-1\n"
 808 "bits-spec:\n"
 809 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 810 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 811 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 812 "            =bit1,bit2                 flags == (bit1|bit2)\n"
 813 "bit-names:\n"
 814         );
 815
 816         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 817                 if (!page_flag_names[i])
 818                         continue;
 819                 printf("%16s%s", page_flag_names[i] + 2,
 820                                  page_flag_type(1ULL << i));
 821                 if (++j > 3) {
 822                         j = 0;
 823                         putchar('\n');
 824                 }
 825         }
 826         printf("\n                                   "
 827                 "(r) raw mode bits  (o) overloaded bits\n");
 828 }
 829
 830 static unsigned long long parse_number(const char *str)
 831 {
 832         unsigned long long n;
 833
 834         n = strtoll(str, NULL, 0);
 835
 836         if (n == 0 && str[0] != '0')
 837                 fatal("invalid name or number: %s\n", str);
 838
 839         return n;
 840 }
 841
 842 static void parse_pid(const char *str)
 843 {
 844         FILE *file;
 845         char buf[5000];
 846
 847         opt_pid = parse_number(str);
 848
 849         sprintf(buf, "/proc/%d/pagemap", opt_pid);
 850         pagemap_fd = checked_open(buf, O_RDONLY);
 851
 852         sprintf(buf, "/proc/%d/maps", opt_pid);
 853         file = fopen(buf, "r");
 854         if (!file) {
 855                 perror(buf);
 856                 exit(EXIT_FAILURE);
 857         }
 858
 859         while (fgets(buf, sizeof(buf), file) != NULL) {
 860                 unsigned long vm_start;
 861                 unsigned long vm_end;
 862                 unsigned long long pgoff;
 863                 int major, minor;
 864                 char r, w, x, s;
 865                 unsigned long ino;
 866                 int n;
 867
 868                 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 869                            &vm_start,
 870                            &vm_end,
 871                            &r, &w, &x, &s,
 872                            &pgoff,
 873                            &major, &minor,
 874                            &ino);
 875                 if (n < 10) {
 876                         fprintf(stderr, "unexpected line: %s\n", buf);
 877                         continue;
 878                 }
 879                 pg_start[nr_vmas] = vm_start / page_size;
 880                 pg_end[nr_vmas] = vm_end / page_size;
 881                 if (++nr_vmas >= MAX_VMAS) {
 882                         fprintf(stderr, "too many VMAs\n");
 883                         break;
 884                 }
 885         }
 886         fclose(file);
 887 }
 888
 889 static void parse_file(const char *name)
 890 {
 891 }
 892
 893 static void parse_addr_range(const char *optarg)
 894 {
 895         unsigned long offset;
 896         unsigned long size;
 897         char *p;
 898
 899         p = strchr(optarg, ',');
 900         if (!p)
 901                 p = strchr(optarg, '+');
 902
 903         if (p == optarg) {
 904                 offset = 0;
 905                 size   = parse_number(p + 1);
 906         } else if (p) {
 907                 offset = parse_number(optarg);
 908                 if (p[1] == '\0')
 909                         size = ULONG_MAX;
 910                 else {
 911                         size = parse_number(p + 1);
 912                         if (*p == ',') {
 913                                 if (size < offset)
 914                                         fatal("invalid range: %lu,%lu\n",
 915                                                         offset, size);
 916                                 size -= offset;
 917                         }
 918                 }
 919         } else {
 920                 offset = parse_number(optarg);
 921                 size   = 1;
 922         }
 923
 924         add_addr_range(offset, size);
 925 }
 926
 927 static void add_bits_filter(uint64_t mask, uint64_t bits)
 928 {
 929         if (nr_bit_filters >= MAX_BIT_FILTERS)
 930                 fatal("too much bit filters\n");
 931
 932         opt_mask[nr_bit_filters] = mask;
 933         opt_bits[nr_bit_filters] = bits;
 934         nr_bit_filters++;
 935 }
 936
 937 static uint64_t parse_flag_name(const char *str, int len)
 938 {
 939         int i;
 940
 941         if (!*str || !len)
 942                 return 0;
 943
 944         if (len <= 8 && !strncmp(str, "compound", len))
 945                 return BITS_COMPOUND;
 946
 947         for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 948                 if (!page_flag_names[i])
 949                         continue;
 950                 if (!strncmp(str, page_flag_names[i] + 2, len))
 951                         return 1ULL << i;
 952         }
 953
 954         return parse_number(str);
 955 }
 956
 957 static uint64_t parse_flag_names(const char *str, int all)
 958 {
 959         const char *p    = str;
 960         uint64_t   flags = 0;
 961
 962         while (1) {
 963                 if (*p == ',' || *p == '=' || *p == '\0') {
 964                         if ((*str != '~') || (*str == '~' && all && *++str))
 965                                 flags |= parse_flag_name(str, p - str);
 966                         if (*p != ',')
 967                                 break;
 968                         str = p + 1;
 969                 }
 970                 p++;
 971         }
 972
 973         return flags;
 974 }
 975
 976 static void parse_bits_mask(const char *optarg)
 977 {
 978         uint64_t mask;
 979         uint64_t bits;
 980         const char *p;
 981
 982         p = strchr(optarg, '=');
 983         if (p == optarg) {
 984                 mask = KPF_ALL_BITS;
 985                 bits = parse_flag_names(p + 1, 0);
 986         } else if (p) {
 987                 mask = parse_flag_names(optarg, 0);
 988                 bits = parse_flag_names(p + 1, 0);
 989         } else if (strchr(optarg, '~')) {
 990                 mask = parse_flag_names(optarg, 1);
 991                 bits = parse_flag_names(optarg, 0);
 992         } else {
 993                 mask = parse_flag_names(optarg, 0);
 994                 bits = KPF_ALL_BITS;
 995         }
 996
 997         add_bits_filter(mask, bits);
 998 }
 999
1000 static void describe_flags(const char *optarg)
1001 {
1002         uint64_t flags = parse_flag_names(optarg, 0);
1003
1004         printf("0x%016llx\t%s\t%s\n",
1005                 (unsigned long long)flags,
1006                 page_flag_name(flags),
1007                 page_flag_longname(flags));
1008 }
1009
1010 static const struct option opts[] = {
1011         { "raw"       , 0, NULL, 'r' },
1012         { "pid"       , 1, NULL, 'p' },
1013         { "file"      , 1, NULL, 'f' },
1014         { "addr"      , 1, NULL, 'a' },
1015         { "bits"      , 1, NULL, 'b' },
1016         { "describe"  , 1, NULL, 'd' },
1017         { "list"      , 0, NULL, 'l' },
1018         { "list-each" , 0, NULL, 'L' },
1019         { "no-summary", 0, NULL, 'N' },
1020         { "hwpoison"  , 0, NULL, 'X' },
1021         { "unpoison"  , 0, NULL, 'x' },
1022         { "help"      , 0, NULL, 'h' },
1023         { NULL        , 0, NULL, 0 }
1024 };
1025
1026 int main(int argc, char *argv[])
1027 {
1028         int c;
1029
1030         page_size = getpagesize();
1031
1032         while ((c = getopt_long(argc, argv,
1033                                 "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1034                 switch (c) {
1035                 case 'r':
1036                         opt_raw = 1;
1037                         break;
1038                 case 'p':
1039                         parse_pid(optarg);
1040                         break;
1041                 case 'f':
1042                         parse_file(optarg);
1043                         break;
1044                 case 'a':
1045                         parse_addr_range(optarg);
1046                         break;
1047                 case 'b':
1048                         parse_bits_mask(optarg);
1049                         break;
1050                 case 'd':
1051                         describe_flags(optarg);
1052                         exit(0);
1053                 case 'l':
1054                         opt_list = 1;
1055                         break;
1056                 case 'L':
1057                         opt_list = 2;
1058                         break;
1059                 case 'N':
1060                         opt_no_summary = 1;
1061                         break;
1062                 case 'X':
1063                         opt_hwpoison = 1;
1064                         prepare_hwpoison_fd();
1065                         break;
1066                 case 'x':
1067                         opt_unpoison = 1;
1068                         prepare_hwpoison_fd();
1069                         break;
1070                 case 'h':
1071                         usage();
1072                         exit(0);
1073                 default:
1074                         usage();
1075                         exit(1);
1076                 }
1077         }
1078
1079         if (opt_list && opt_pid)
1080                 printf("voffset\t");
1081         if (opt_list == 1)
1082                 printf("offset\tlen\tflags\n");
1083         if (opt_list == 2)
1084                 printf("offset\tflags\n");
1085
1086         walk_addr_ranges();
1087
1088         if (opt_list == 1)
1089                 show_page_range(0, 0, 0);  /* drain the buffer */
1090
1091         if (opt_no_summary)
1092                 return 0;
1093
1094         if (opt_list)
1095                 printf("\n\n");
1096
1097         show_summary();
1098
1099         return 0;
1100 }