tools/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 _FILE_OFFSET_BITS 64
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <stdint.h>
  28 #include <stdarg.h>
  29 #include <string.h>
  30 #include <getopt.h>
  31 #include <limits.h>
  32 #include <assert.h>
  33 #include <ftw.h>
  34 #include <time.h>
  35 #include <setjmp.h>
  36 #include <signal.h>
  37 #include <sys/types.h>
  38 #include <sys/errno.h>
  39 #include <sys/fcntl.h>
  40 #include <sys/mount.h>
  41 #include <sys/statfs.h>
  42 #include <sys/mman.h>
  43 #include "../../include/uapi/linux/magic.h"
  44 #include "../../include/uapi/linux/kernel-page-flags.h"
  45 #include <api/fs/fs.h>
  46
  47 #ifndef MAX_PATH
  48 # define MAX_PATH 256
  49 #endif
  50
  51 #ifndef STR
  52 # define _STR(x) #x
  53 # define STR(x) _STR(x)
  54 #endif
  55
  56 /*
  57  * pagemap kernel ABI bits
  58  */
  59
  60 #define PM_ENTRY_BYTES          8
  61 #define PM_PFRAME_BITS          55
  62 #define PM_PFRAME_MASK          ((1LL << PM_PFRAME_BITS) - 1)
  63 #define PM_PFRAME(x)            ((x) & PM_PFRAME_MASK)
  64 #define PM_SOFT_DIRTY           (1ULL << 55)
  65 #define PM_MMAP_EXCLUSIVE       (1ULL << 56)
  66 #define PM_FILE                 (1ULL << 61)
  67 #define PM_SWAP                 (1ULL << 62)
  68 #define PM_PRESENT              (1ULL << 63)
  69
  70 /*
  71  * kernel page flags
  72  */
  73
  74 #define KPF_BYTES               8
  75 #define PROC_KPAGEFLAGS         "/proc/kpageflags"
  76
  77 /* [32-] kernel hacking assistances */
  78 #define KPF_RESERVED            32
  79 #define KPF_MLOCKED             33
  80 #define KPF_MAPPEDTODISK        34
  81 #define KPF_PRIVATE             35
  82 #define KPF_PRIVATE_2           36
  83 #define KPF_OWNER_PRIVATE       37
  84 #define KPF_ARCH                38
  85 #define KPF_UNCACHED            39
  86 #define KPF_SOFTDIRTY           40
  87
  88 /* [48-] take some arbitrary free slots for expanding overloaded flags
  89  * not part of kernel API
  90  */
  91 #define KPF_READAHEAD           48
  92 #define KPF_SLOB_FREE           49
  93 #define KPF_SLUB_FROZEN         50
  94 #define KPF_SLUB_DEBUG          51
  95 #define KPF_FILE                62
  96 #define KPF_MMAP_EXCLUSIVE      63
  97
  98 #define KPF_ALL_BITS            ((uint64_t)~0ULL)
  99 #define KPF_HACKERS_BITS        (0xffffULL << 32)
 100 #define KPF_OVERLOADED_BITS     (0xffffULL << 48)
 101 #define BIT(name)               (1ULL << KPF_##name)
 102 #define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
 103
 104 static const char * const page_flag_names[] = {
 105         [KPF_LOCKED]            = "L:locked",
 106         [KPF_ERROR]             = "E:error",
 107         [KPF_REFERENCED]        = "R:referenced",
 108         [KPF_UPTODATE]          = "U:uptodate",
 109         [KPF_DIRTY]             = "D:dirty",
 110         [KPF_LRU]               = "l:lru",
 111         [KPF_ACTIVE]            = "A:active",
 112         [KPF_SLAB]              = "S:slab",
 113         [KPF_WRITEBACK]         = "W:writeback",
 114         [KPF_RECLAIM]           = "I:reclaim",
 115         [KPF_BUDDY]             = "B:buddy",
 116
 117         [KPF_MMAP]              = "M:mmap",
 118         [KPF_ANON]              = "a:anonymous",
 119         [KPF_SWAPCACHE]         = "s:swapcache",
 120         [KPF_SWAPBACKED]        = "b:swapbacked",
 121         [KPF_COMPOUND_HEAD]     = "H:compound_head",
 122         [KPF_COMPOUND_TAIL]     = "T:compound_tail",
 123         [KPF_HUGE]              = "G:huge",
 124         [KPF_UNEVICTABLE]       = "u:unevictable",
 125         [KPF_HWPOISON]          = "X:hwpoison",
 126         [KPF_NOPAGE]            = "n:nopage",
 127         [KPF_KSM]               = "x:ksm",
 128         [KPF_THP]               = "t:thp",
 129         [KPF_BALLOON]           = "o:balloon",
 130         [KPF_ZERO_PAGE]         = "z:zero_page",
 131
 132         [KPF_RESERVED]          = "r:reserved",
 133         [KPF_MLOCKED]           = "m:mlocked",
 134         [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
 135         [KPF_PRIVATE]           = "P:private",
 136         [KPF_PRIVATE_2]         = "p:private_2",
 137         [KPF_OWNER_PRIVATE]     = "O:owner_private",
 138         [KPF_ARCH]              = "h:arch",
 139         [KPF_UNCACHED]          = "c:uncached",
 140         [KPF_SOFTDIRTY]         = "f:softdirty",
 141
 142         [KPF_READAHEAD]         = "I:readahead",
 143         [KPF_SLOB_FREE]         = "P:slob_free",
 144         [KPF_SLUB_FROZEN]       = "A:slub_frozen",
 145         [KPF_SLUB_DEBUG]        = "E:slub_debug",
 146
 147         [KPF_FILE]              = "F:file",
 148         [KPF_MMAP_EXCLUSIVE]    = "1:mmap_exclusive",
 149 };
 150
 151
 152 static const char * const debugfs_known_mountpoints[] = {
 153         "/sys/kernel/debug",
 154         "/debug",
 155         0,
 156 };
 157
 158 /*
 159  * data structures
 160  */
 161
 162 static int              opt_raw;        /* for kernel developers */
 163 static int              opt_list;       /* list pages (in ranges) */
 164 static int              opt_no_summary; /* don't show summary */
 165 static pid_t            opt_pid;        /* process to walk */
 166 const char *            opt_file;
 167
 168 #define MAX_ADDR_RANGES 1024
 169 static int              nr_addr_ranges;
 170 static unsigned long    opt_offset[MAX_ADDR_RANGES];
 171 static unsigned long    opt_size[MAX_ADDR_RANGES];
 172
 173 #define MAX_VMAS        10240
 174 static int              nr_vmas;
 175 static unsigned long    pg_start[MAX_VMAS];
 176 static unsigned long    pg_end[MAX_VMAS];
 177
 178 #define MAX_BIT_FILTERS 64
 179 static int              nr_bit_filters;
 180 static uint64_t         opt_mask[MAX_BIT_FILTERS];
 181 static uint64_t         opt_bits[MAX_BIT_FILTERS];
 182
 183 static int              page_size;
 184
 185 static int              pagemap_fd;
 186 static int              kpageflags_fd;
 187
 188 static int              opt_hwpoison;
 189 static int              opt_unpoison;
 190
 191 static const char       *hwpoison_debug_fs;
 192 static int              hwpoison_inject_fd;
 193 static int              hwpoison_forget_fd;
 194
 195 #define HASH_SHIFT      13
 196 #define HASH_SIZE       (1 << HASH_SHIFT)
 197 #define HASH_MASK       (HASH_SIZE - 1)
 198 #define HASH_KEY(flags) (flags & HASH_MASK)
 199
 200 static unsigned long    total_pages;
 201 static unsigned long    nr_pages[HASH_SIZE];
 202 static uint64_t         page_flags[HASH_SIZE];
 203
 204
 205 /*
 206  * helper functions
 207  */
 208
 209 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 210
 211 #define min_t(type, x, y) ({                    \
 212         type __min1 = (x);                      \
 213         type __min2 = (y);                      \
 214         __min1 < __min2 ? __min1 : __min2; })
 215
 216 #define max_t(type, x, y) ({                    \
 217         type __max1 = (x);                      \
 218         type __max2 = (y);                      \
 219         __max1 > __max2 ? __max1 : __max2; })
 220
 221 static unsigned long pages2mb(unsigned long pages)
 222 {
 223         return (pages * page_size) >> 20;
 224 }
 225
 226 static void fatal(const char *x, ...)
 227 {
 228         va_list ap;
 229
 230         va_start(ap, x);
 231         vfprintf(stderr, x, ap);
 232         va_end(ap);
 233         exit(EXIT_FAILURE);
 234 }
 235
 236 static int checked_open(const char *pathname, int flags)
 237 {
 238         int fd = open(pathname, flags);
 239
 240         if (fd < 0) {
 241                 perror(pathname);
 242                 exit(EXIT_FAILURE);
 243         }
 244
 245         return fd;
 246 }
 247
 248 /*
 249  * pagemap/kpageflags routines
 250  */
 251
 252 static unsigned long do_u64_read(int fd, char *name,
 253                                  uint64_t *buf,
 254                                  unsigned long index,
 255                                  unsigned long count)
 256 {
 257         long bytes;
 258
 259         if (index > ULONG_MAX / 8)
 260                 fatal("index overflow: %lu\n", index);
 261
 262         bytes = pread(fd, buf, count * 8, (off_t)index * 8);
 263         if (bytes < 0) {
 264                 perror(name);
 265                 exit(EXIT_FAILURE);
 266         }
 267         if (bytes % 8)
 268                 fatal("partial read: %lu bytes\n", bytes);
 269
 270         return bytes / 8;
 271 }
 272
 273 static unsigned long kpageflags_read(uint64_t *buf,
 274                                      unsigned long index,
 275                                      unsigned long pages)
 276 {
 277         return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
 278 }
 279
 280 static unsigned long pagemap_read(uint64_t *buf,
 281                                   unsigned long index,
 282                                   unsigned long pages)
 283 {
 284         return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
 285 }
 286
 287 static unsigned long pagemap_pfn(uint64_t val)
 288 {
 289         unsigned long pfn;
 290
 291         if (val & PM_PRESENT)
 292                 pfn = PM_PFRAME(val);
 293         else
 294                 pfn = 0;
 295
 296         return pfn;
 297 }
 298
 299
 300 /*
 301  * page flag names
 302  */
 303
 304 static char *page_flag_name(uint64_t flags)
 305 {
 306         static char buf[65];
 307         int present;
 308         size_t i, j;
 309
 310         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 311                 present = (flags >> i) & 1;
 312                 if (!page_flag_names[i]) {
 313                         if (present)
 314                                 fatal("unknown flag bit %d\n", i);
 315                         continue;
 316                 }
 317                 buf[j++] = present ? page_flag_names[i][0] : '_';
 318         }
 319
 320         return buf;
 321 }
 322
 323 static char *page_flag_longname(uint64_t flags)
 324 {
 325         static char buf[1024];
 326         size_t i, n;
 327
 328         for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 329                 if (!page_flag_names[i])
 330                         continue;
 331                 if ((flags >> i) & 1)
 332                         n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 333                                         page_flag_names[i] + 2);
 334         }
 335         if (n)
 336                 n--;
 337         buf[n] = '\0';
 338
 339         return buf;
 340 }
 341
 342
 343 /*
 344  * page list and summary
 345  */
 346
 347 static void show_page_range(unsigned long voffset, unsigned long offset,
 348                             unsigned long size, uint64_t flags)
 349 {
 350         static uint64_t      flags0;
 351         static unsigned long voff;
 352         static unsigned long index;
 353         static unsigned long count;
 354
 355         if (flags == flags0 && offset == index + count &&
 356             size && voffset == voff + count) {
 357                 count += size;
 358                 return;
 359         }
 360
 361         if (count) {
 362                 if (opt_pid)
 363                         printf("%lx\t", voff);
 364                 if (opt_file)
 365                         printf("%lu\t", voff);
 366                 printf("%lx\t%lx\t%s\n",
 367                                 index, count, page_flag_name(flags0));
 368         }
 369
 370         flags0 = flags;
 371         index  = offset;
 372         voff   = voffset;
 373         count  = size;
 374 }
 375
 376 static void flush_page_range(void)
 377 {
 378         show_page_range(0, 0, 0, 0);
 379 }
 380
 381 static void show_page(unsigned long voffset,
 382                       unsigned long offset, uint64_t flags)
 383 {
 384         if (opt_pid)
 385                 printf("%lx\t", voffset);
 386         if (opt_file)
 387                 printf("%lu\t", voffset);
 388         printf("%lx\t%s\n", offset, page_flag_name(flags));
 389 }
 390
 391 static void show_summary(void)
 392 {
 393         size_t i;
 394
 395         printf("             flags\tpage-count       MB"
 396                 "  symbolic-flags\t\t\tlong-symbolic-flags\n");
 397
 398         for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 399                 if (nr_pages[i])
 400                         printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 401                                 (unsigned long long)page_flags[i],
 402                                 nr_pages[i],
 403                                 pages2mb(nr_pages[i]),
 404                                 page_flag_name(page_flags[i]),
 405                                 page_flag_longname(page_flags[i]));
 406         }
 407
 408         printf("             total\t%10lu %8lu\n",
 409                         total_pages, pages2mb(total_pages));
 410 }
 411
 412
 413 /*
 414  * page flag filters
 415  */
 416
 417 static int bit_mask_ok(uint64_t flags)
 418 {
 419         int i;
 420
 421         for (i = 0; i < nr_bit_filters; i++) {
 422                 if (opt_bits[i] == KPF_ALL_BITS) {
 423                         if ((flags & opt_mask[i]) == 0)
 424                                 return 0;
 425                 } else {
 426                         if ((flags & opt_mask[i]) != opt_bits[i])
 427                                 return 0;
 428                 }
 429         }
 430
 431         return 1;
 432 }
 433
 434 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
 435 {
 436         /* SLOB/SLUB overload several page flags */
 437         if (flags & BIT(SLAB)) {
 438                 if (flags & BIT(PRIVATE))
 439                         flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 440                 if (flags & BIT(ACTIVE))
 441                         flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 442                 if (flags & BIT(ERROR))
 443                         flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 444         }
 445
 446         /* PG_reclaim is overloaded as PG_readahead in the read path */
 447         if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 448                 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 449
 450         if (pme & PM_SOFT_DIRTY)
 451                 flags |= BIT(SOFTDIRTY);
 452         if (pme & PM_FILE)
 453                 flags |= BIT(FILE);
 454         if (pme & PM_MMAP_EXCLUSIVE)
 455                 flags |= BIT(MMAP_EXCLUSIVE);
 456
 457         return flags;
 458 }
 459
 460 static uint64_t well_known_flags(uint64_t flags)
 461 {
 462         /* hide flags intended only for kernel hacker */
 463         flags &= ~KPF_HACKERS_BITS;
 464
 465         /* hide non-hugeTLB compound pages */
 466         if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 467                 flags &= ~BITS_COMPOUND;
 468
 469         return flags;
 470 }
 471
 472 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 473 {
 474         if (opt_raw)
 475                 flags = expand_overloaded_flags(flags, pme);
 476         else
 477                 flags = well_known_flags(flags);
 478
 479         return flags;
 480 }
 481
 482 /*
 483  * page actions
 484  */
 485
 486 static void prepare_hwpoison_fd(void)
 487 {
 488         char buf[MAX_PATH + 1];
 489
 490         hwpoison_debug_fs = debugfs__mount();
 491         if (!hwpoison_debug_fs) {
 492                 perror("mount debugfs");
 493                 exit(EXIT_FAILURE);
 494         }
 495
 496         if (opt_hwpoison && !hwpoison_inject_fd) {
 497                 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 498                         hwpoison_debug_fs);
 499                 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 500         }
 501
 502         if (opt_unpoison && !hwpoison_forget_fd) {
 503                 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 504                         hwpoison_debug_fs);
 505                 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 506         }
 507 }
 508
 509 static int hwpoison_page(unsigned long offset)
 510 {
 511         char buf[100];
 512         int len;
 513
 514         len = sprintf(buf, "0x%lx\n", offset);
 515         len = write(hwpoison_inject_fd, buf, len);
 516         if (len < 0) {
 517                 perror("hwpoison inject");
 518                 return len;
 519         }
 520         return 0;
 521 }
 522
 523 static int unpoison_page(unsigned long offset)
 524 {
 525         char buf[100];
 526         int len;
 527
 528         len = sprintf(buf, "0x%lx\n", offset);
 529         len = write(hwpoison_forget_fd, buf, len);
 530         if (len < 0) {
 531                 perror("hwpoison forget");
 532                 return len;
 533         }
 534         return 0;
 535 }
 536
 537 /*
 538  * page frame walker
 539  */
 540
 541 static size_t hash_slot(uint64_t flags)
 542 {
 543         size_t k = HASH_KEY(flags);
 544         size_t i;
 545
 546         /* Explicitly reserve slot 0 for flags 0: the following logic
 547          * cannot distinguish an unoccupied slot from slot (flags==0).
 548          */
 549         if (flags == 0)
 550                 return 0;
 551
 552         /* search through the remaining (HASH_SIZE-1) slots */
 553         for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 554                 if (!k || k >= ARRAY_SIZE(page_flags))
 555                         k = 1;
 556                 if (page_flags[k] == 0) {
 557                         page_flags[k] = flags;
 558                         return k;
 559                 }
 560                 if (page_flags[k] == flags)
 561                         return k;
 562         }
 563
 564         fatal("hash table full: bump up HASH_SHIFT?\n");
 565         exit(EXIT_FAILURE);
 566 }
 567
 568 static void add_page(unsigned long voffset,
 569                      unsigned long offset, uint64_t flags, uint64_t pme)
 570 {
 571         flags = kpageflags_flags(flags, pme);
 572
 573         if (!bit_mask_ok(flags))
 574                 return;
 575
 576         if (opt_hwpoison)
 577                 hwpoison_page(offset);
 578         if (opt_unpoison)
 579                 unpoison_page(offset);
 580
 581         if (opt_list == 1)
 582                 show_page_range(voffset, offset, 1, flags);
 583         else if (opt_list == 2)
 584                 show_page(voffset, offset, flags);
 585
 586         nr_pages[hash_slot(flags)]++;
 587         total_pages++;
 588 }
 589
 590 #define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 591 static void walk_pfn(unsigned long voffset,
 592                      unsigned long index,
 593                      unsigned long count,
 594                      uint64_t pme)
 595 {
 596         uint64_t buf[KPAGEFLAGS_BATCH];
 597         unsigned long batch;
 598         unsigned long pages;
 599         unsigned long i;
 600
 601         while (count) {
 602                 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 603                 pages = kpageflags_read(buf, index, batch);
 604                 if (pages == 0)
 605                         break;
 606
 607                 for (i = 0; i < pages; i++)
 608                         add_page(voffset + i, index + i, buf[i], pme);
 609
 610                 index += pages;
 611                 count -= pages;
 612         }
 613 }
 614
 615 #define PAGEMAP_BATCH   (64 << 10)
 616 static void walk_vma(unsigned long index, unsigned long count)
 617 {
 618         uint64_t buf[PAGEMAP_BATCH];
 619         unsigned long batch;
 620         unsigned long pages;
 621         unsigned long pfn;
 622         unsigned long i;
 623
 624         while (count) {
 625                 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 626                 pages = pagemap_read(buf, index, batch);
 627                 if (pages == 0)
 628                         break;
 629
 630                 for (i = 0; i < pages; i++) {
 631                         pfn = pagemap_pfn(buf[i]);
 632                         if (pfn)
 633                                 walk_pfn(index + i, pfn, 1, buf[i]);
 634                 }
 635
 636                 index += pages;
 637                 count -= pages;
 638         }
 639 }
 640
 641 static void walk_task(unsigned long index, unsigned long count)
 642 {
 643         const unsigned long end = index + count;
 644         unsigned long start;
 645         int i = 0;
 646
 647         while (index < end) {
 648
 649                 while (pg_end[i] <= index)
 650                         if (++i >= nr_vmas)
 651                                 return;
 652                 if (pg_start[i] >= end)
 653                         return;
 654
 655                 start = max_t(unsigned long, pg_start[i], index);
 656                 index = min_t(unsigned long, pg_end[i], end);
 657
 658                 assert(start < index);
 659                 walk_vma(start, index - start);
 660         }
 661 }
 662
 663 static void add_addr_range(unsigned long offset, unsigned long size)
 664 {
 665         if (nr_addr_ranges >= MAX_ADDR_RANGES)
 666                 fatal("too many addr ranges\n");
 667
 668         opt_offset[nr_addr_ranges] = offset;
 669         opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 670         nr_addr_ranges++;
 671 }
 672
 673 static void walk_addr_ranges(void)
 674 {
 675         int i;
 676
 677         kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 678
 679         if (!nr_addr_ranges)
 680                 add_addr_range(0, ULONG_MAX);
 681
 682         for (i = 0; i < nr_addr_ranges; i++)
 683                 if (!opt_pid)
 684                         walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 685                 else
 686                         walk_task(opt_offset[i], opt_size[i]);
 687
 688         close(kpageflags_fd);
 689 }
 690
 691
 692 /*
 693  * user interface
 694  */
 695
 696 static const char *page_flag_type(uint64_t flag)
 697 {
 698         if (flag & KPF_HACKERS_BITS)
 699                 return "(r)";
 700         if (flag & KPF_OVERLOADED_BITS)
 701                 return "(o)";
 702         return "   ";
 703 }
 704
 705 static void usage(void)
 706 {
 707         size_t i, j;
 708
 709         printf(
 710 "page-types [options]\n"
 711 "            -r|--raw                   Raw mode, for kernel developers\n"
 712 "            -d|--describe flags        Describe flags\n"
 713 "            -a|--addr    addr-spec     Walk a range of pages\n"
 714 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
 715 "            -p|--pid     pid           Walk process address space\n"
 716 "            -f|--file    filename      Walk file address space\n"
 717 "            -l|--list                  Show page details in ranges\n"
 718 "            -L|--list-each             Show page details one by one\n"
 719 "            -N|--no-summary            Don't show summary info\n"
 720 "            -X|--hwpoison              hwpoison pages\n"
 721 "            -x|--unpoison              unpoison pages\n"
 722 "            -h|--help                  Show this usage message\n"
 723 "flags:\n"
 724 "            0x10                       bitfield format, e.g.\n"
 725 "            anon                       bit-name, e.g.\n"
 726 "            0x10,anon                  comma-separated list, e.g.\n"
 727 "addr-spec:\n"
 728 "            N                          one page at offset N (unit: pages)\n"
 729 "            N+M                        pages range from N to N+M-1\n"
 730 "            N,M                        pages range from N to M-1\n"
 731 "            N,                         pages range from N to end\n"
 732 "            ,M                         pages range from 0 to M-1\n"
 733 "bits-spec:\n"
 734 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 735 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 736 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 737 "            =bit1,bit2                 flags == (bit1|bit2)\n"
 738 "bit-names:\n"
 739         );
 740
 741         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 742                 if (!page_flag_names[i])
 743                         continue;
 744                 printf("%16s%s", page_flag_names[i] + 2,
 745                                  page_flag_type(1ULL << i));
 746                 if (++j > 3) {
 747                         j = 0;
 748                         putchar('\n');
 749                 }
 750         }
 751         printf("\n                                   "
 752                 "(r) raw mode bits  (o) overloaded bits\n");
 753 }
 754
 755 static unsigned long long parse_number(const char *str)
 756 {
 757         unsigned long long n;
 758
 759         n = strtoll(str, NULL, 0);
 760
 761         if (n == 0 && str[0] != '0')
 762                 fatal("invalid name or number: %s\n", str);
 763
 764         return n;
 765 }
 766
 767 static void parse_pid(const char *str)
 768 {
 769         FILE *file;
 770         char buf[5000];
 771
 772         opt_pid = parse_number(str);
 773
 774         sprintf(buf, "/proc/%d/pagemap", opt_pid);
 775         pagemap_fd = checked_open(buf, O_RDONLY);
 776
 777         sprintf(buf, "/proc/%d/maps", opt_pid);
 778         file = fopen(buf, "r");
 779         if (!file) {
 780                 perror(buf);
 781                 exit(EXIT_FAILURE);
 782         }
 783
 784         while (fgets(buf, sizeof(buf), file) != NULL) {
 785                 unsigned long vm_start;
 786                 unsigned long vm_end;
 787                 unsigned long long pgoff;
 788                 int major, minor;
 789                 char r, w, x, s;
 790                 unsigned long ino;
 791                 int n;
 792
 793                 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 794                            &vm_start,
 795                            &vm_end,
 796                            &r, &w, &x, &s,
 797                            &pgoff,
 798                            &major, &minor,
 799                            &ino);
 800                 if (n < 10) {
 801                         fprintf(stderr, "unexpected line: %s\n", buf);
 802                         continue;
 803                 }
 804                 pg_start[nr_vmas] = vm_start / page_size;
 805                 pg_end[nr_vmas] = vm_end / page_size;
 806                 if (++nr_vmas >= MAX_VMAS) {
 807                         fprintf(stderr, "too many VMAs\n");
 808                         break;
 809                 }
 810         }
 811         fclose(file);
 812 }
 813
 814 static void show_file(const char *name, const struct stat *st)
 815 {
 816         unsigned long long size = st->st_size;
 817         char atime[64], mtime[64];
 818         long now = time(NULL);
 819
 820         printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 821                         name, (unsigned)st->st_ino,
 822                         size, (size + page_size - 1) / page_size);
 823
 824         strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 825         strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 826
 827         printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 828                         mtime, now - st->st_mtime,
 829                         atime, now - st->st_atime);
 830 }
 831
 832 static sigjmp_buf sigbus_jmp;
 833
 834 static void * volatile sigbus_addr;
 835
 836 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 837 {
 838         (void)sig;
 839         (void)ucontex;
 840         sigbus_addr = info ? info->si_addr : NULL;
 841         siglongjmp(sigbus_jmp, 1);
 842 }
 843
 844 static struct sigaction sigbus_action = {
 845         .sa_sigaction = sigbus_handler,
 846         .sa_flags = SA_SIGINFO,
 847 };
 848
 849 static void walk_file(const char *name, const struct stat *st)
 850 {
 851         uint8_t vec[PAGEMAP_BATCH];
 852         uint64_t buf[PAGEMAP_BATCH], flags;
 853         unsigned long nr_pages, pfn, i;
 854         off_t off, end = st->st_size;
 855         int fd;
 856         ssize_t len;
 857         void *ptr;
 858         int first = 1;
 859
 860         fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
 861
 862         for (off = 0; off < end; off += len) {
 863                 nr_pages = (end - off + page_size - 1) / page_size;
 864                 if (nr_pages > PAGEMAP_BATCH)
 865                         nr_pages = PAGEMAP_BATCH;
 866                 len = nr_pages * page_size;
 867
 868                 ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 869                 if (ptr == MAP_FAILED)
 870                         fatal("mmap failed: %s", name);
 871
 872                 /* determine cached pages */
 873                 if (mincore(ptr, len, vec))
 874                         fatal("mincore failed: %s", name);
 875
 876                 /* turn off readahead */
 877                 if (madvise(ptr, len, MADV_RANDOM))
 878                         fatal("madvice failed: %s", name);
 879
 880                 if (sigsetjmp(sigbus_jmp, 1)) {
 881                         end = off + sigbus_addr ? sigbus_addr - ptr : 0;
 882                         fprintf(stderr, "got sigbus at offset %lld: %s\n",
 883                                         (long long)end, name);
 884                         goto got_sigbus;
 885                 }
 886
 887                 /* populate ptes */
 888                 for (i = 0; i < nr_pages ; i++) {
 889                         if (vec[i] & 1)
 890                                 (void)*(volatile int *)(ptr + i * page_size);
 891                 }
 892 got_sigbus:
 893
 894                 /* turn off harvesting reference bits */
 895                 if (madvise(ptr, len, MADV_SEQUENTIAL))
 896                         fatal("madvice failed: %s", name);
 897
 898                 if (pagemap_read(buf, (unsigned long)ptr / page_size,
 899                                         nr_pages) != nr_pages)
 900                         fatal("cannot read pagemap");
 901
 902                 munmap(ptr, len);
 903
 904                 for (i = 0; i < nr_pages; i++) {
 905                         pfn = pagemap_pfn(buf[i]);
 906                         if (!pfn)
 907                                 continue;
 908                         if (!kpageflags_read(&flags, pfn, 1))
 909                                 continue;
 910                         if (first && opt_list) {
 911                                 first = 0;
 912                                 flush_page_range();
 913                                 show_file(name, st);
 914                         }
 915                         add_page(off / page_size + i, pfn, flags, buf[i]);
 916                 }
 917         }
 918
 919         close(fd);
 920 }
 921
 922 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
 923 {
 924         (void)f;
 925         switch (type) {
 926         case FTW_F:
 927                 if (S_ISREG(st->st_mode))
 928                         walk_file(name, st);
 929                 break;
 930         case FTW_DNR:
 931                 fprintf(stderr, "cannot read dir: %s\n", name);
 932                 break;
 933         }
 934         return 0;
 935 }
 936
 937 static void walk_page_cache(void)
 938 {
 939         struct stat st;
 940
 941         kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 942         pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
 943         sigaction(SIGBUS, &sigbus_action, NULL);
 944
 945         if (stat(opt_file, &st))
 946                 fatal("stat failed: %s\n", opt_file);
 947
 948         if (S_ISREG(st.st_mode)) {
 949                 walk_file(opt_file, &st);
 950         } else if (S_ISDIR(st.st_mode)) {
 951                 /* do not follow symlinks and mountpoints */
 952                 if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
 953                         fatal("nftw failed: %s\n", opt_file);
 954         } else
 955                 fatal("unhandled file type: %s\n", opt_file);
 956
 957         close(kpageflags_fd);
 958         close(pagemap_fd);
 959         signal(SIGBUS, SIG_DFL);
 960 }
 961
 962 static void parse_file(const char *name)
 963 {
 964         opt_file = name;
 965 }
 966
 967 static void parse_addr_range(const char *optarg)
 968 {
 969         unsigned long offset;
 970         unsigned long size;
 971         char *p;
 972
 973         p = strchr(optarg, ',');
 974         if (!p)
 975                 p = strchr(optarg, '+');
 976
 977         if (p == optarg) {
 978                 offset = 0;
 979                 size   = parse_number(p + 1);
 980         } else if (p) {
 981                 offset = parse_number(optarg);
 982                 if (p[1] == '\0')
 983                         size = ULONG_MAX;
 984                 else {
 985                         size = parse_number(p + 1);
 986                         if (*p == ',') {
 987                                 if (size < offset)
 988                                         fatal("invalid range: %lu,%lu\n",
 989                                                         offset, size);
 990                                 size -= offset;
 991                         }
 992                 }
 993         } else {
 994                 offset = parse_number(optarg);
 995                 size   = 1;
 996         }
 997
 998         add_addr_range(offset, size);
 999 }
1000
1001 static void add_bits_filter(uint64_t mask, uint64_t bits)
1002 {
1003         if (nr_bit_filters >= MAX_BIT_FILTERS)
1004                 fatal("too much bit filters\n");
1005
1006         opt_mask[nr_bit_filters] = mask;
1007         opt_bits[nr_bit_filters] = bits;
1008         nr_bit_filters++;
1009 }
1010
1011 static uint64_t parse_flag_name(const char *str, int len)
1012 {
1013         size_t i;
1014
1015         if (!*str || !len)
1016                 return 0;
1017
1018         if (len <= 8 && !strncmp(str, "compound", len))
1019                 return BITS_COMPOUND;
1020
1021         for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1022                 if (!page_flag_names[i])
1023                         continue;
1024                 if (!strncmp(str, page_flag_names[i] + 2, len))
1025                         return 1ULL << i;
1026         }
1027
1028         return parse_number(str);
1029 }
1030
1031 static uint64_t parse_flag_names(const char *str, int all)
1032 {
1033         const char *p    = str;
1034         uint64_t   flags = 0;
1035
1036         while (1) {
1037                 if (*p == ',' || *p == '=' || *p == '\0') {
1038                         if ((*str != '~') || (*str == '~' && all && *++str))
1039                                 flags |= parse_flag_name(str, p - str);
1040                         if (*p != ',')
1041                                 break;
1042                         str = p + 1;
1043                 }
1044                 p++;
1045         }
1046
1047         return flags;
1048 }
1049
1050 static void parse_bits_mask(const char *optarg)
1051 {
1052         uint64_t mask;
1053         uint64_t bits;
1054         const char *p;
1055
1056         p = strchr(optarg, '=');
1057         if (p == optarg) {
1058                 mask = KPF_ALL_BITS;
1059                 bits = parse_flag_names(p + 1, 0);
1060         } else if (p) {
1061                 mask = parse_flag_names(optarg, 0);
1062                 bits = parse_flag_names(p + 1, 0);
1063         } else if (strchr(optarg, '~')) {
1064                 mask = parse_flag_names(optarg, 1);
1065                 bits = parse_flag_names(optarg, 0);
1066         } else {
1067                 mask = parse_flag_names(optarg, 0);
1068                 bits = KPF_ALL_BITS;
1069         }
1070
1071         add_bits_filter(mask, bits);
1072 }
1073
1074 static void describe_flags(const char *optarg)
1075 {
1076         uint64_t flags = parse_flag_names(optarg, 0);
1077
1078         printf("0x%016llx\t%s\t%s\n",
1079                 (unsigned long long)flags,
1080                 page_flag_name(flags),
1081                 page_flag_longname(flags));
1082 }
1083
1084 static const struct option opts[] = {
1085         { "raw"       , 0, NULL, 'r' },
1086         { "pid"       , 1, NULL, 'p' },
1087         { "file"      , 1, NULL, 'f' },
1088         { "addr"      , 1, NULL, 'a' },
1089         { "bits"      , 1, NULL, 'b' },
1090         { "describe"  , 1, NULL, 'd' },
1091         { "list"      , 0, NULL, 'l' },
1092         { "list-each" , 0, NULL, 'L' },
1093         { "no-summary", 0, NULL, 'N' },
1094         { "hwpoison"  , 0, NULL, 'X' },
1095         { "unpoison"  , 0, NULL, 'x' },
1096         { "help"      , 0, NULL, 'h' },
1097         { NULL        , 0, NULL, 0 }
1098 };
1099
1100 int main(int argc, char *argv[])
1101 {
1102         int c;
1103
1104         page_size = getpagesize();
1105
1106         while ((c = getopt_long(argc, argv,
1107                                 "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1108                 switch (c) {
1109                 case 'r':
1110                         opt_raw = 1;
1111                         break;
1112                 case 'p':
1113                         parse_pid(optarg);
1114                         break;
1115                 case 'f':
1116                         parse_file(optarg);
1117                         break;
1118                 case 'a':
1119                         parse_addr_range(optarg);
1120                         break;
1121                 case 'b':
1122                         parse_bits_mask(optarg);
1123                         break;
1124                 case 'd':
1125                         describe_flags(optarg);
1126                         exit(0);
1127                 case 'l':
1128                         opt_list = 1;
1129                         break;
1130                 case 'L':
1131                         opt_list = 2;
1132                         break;
1133                 case 'N':
1134                         opt_no_summary = 1;
1135                         break;
1136                 case 'X':
1137                         opt_hwpoison = 1;
1138                         prepare_hwpoison_fd();
1139                         break;
1140                 case 'x':
1141                         opt_unpoison = 1;
1142                         prepare_hwpoison_fd();
1143                         break;
1144                 case 'h':
1145                         usage();
1146                         exit(0);
1147                 default:
1148                         usage();
1149                         exit(1);
1150                 }
1151         }
1152
1153         if (opt_list && opt_pid)
1154                 printf("voffset\t");
1155         if (opt_list && opt_file)
1156                 printf("foffset\t");
1157         if (opt_list == 1)
1158                 printf("offset\tlen\tflags\n");
1159         if (opt_list == 2)
1160                 printf("offset\tflags\n");
1161
1162         if (opt_file)
1163                 walk_page_cache();
1164         else
1165                 walk_addr_ranges();
1166
1167         if (opt_list == 1)
1168                 flush_page_range();
1169
1170         if (opt_no_summary)
1171                 return 0;
1172
1173         if (opt_list)
1174                 printf("\n\n");
1175
1176         show_summary();
1177
1178         return 0;
1179 }