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 MAX_SWAPFILES_SHIFT     5
  65 #define PM_SWAP_OFFSET(x)       (((x) & PM_PFRAME_MASK) >> MAX_SWAPFILES_SHIFT)
  66 #define PM_SOFT_DIRTY           (1ULL << 55)
  67 #define PM_MMAP_EXCLUSIVE       (1ULL << 56)
  68 #define PM_FILE                 (1ULL << 61)
  69 #define PM_SWAP                 (1ULL << 62)
  70 #define PM_PRESENT              (1ULL << 63)
  71
  72 /*
  73  * kernel page flags
  74  */
  75
  76 #define KPF_BYTES               8
  77 #define PROC_KPAGEFLAGS         "/proc/kpageflags"
  78 #define PROC_KPAGECGROUP        "/proc/kpagecgroup"
  79
  80 /* [32-] kernel hacking assistances */
  81 #define KPF_RESERVED            32
  82 #define KPF_MLOCKED             33
  83 #define KPF_MAPPEDTODISK        34
  84 #define KPF_PRIVATE             35
  85 #define KPF_PRIVATE_2           36
  86 #define KPF_OWNER_PRIVATE       37
  87 #define KPF_ARCH                38
  88 #define KPF_UNCACHED            39
  89 #define KPF_SOFTDIRTY           40
  90
  91 /* [48-] take some arbitrary free slots for expanding overloaded flags
  92  * not part of kernel API
  93  */
  94 #define KPF_READAHEAD           48
  95 #define KPF_SLOB_FREE           49
  96 #define KPF_SLUB_FROZEN         50
  97 #define KPF_SLUB_DEBUG          51
  98 #define KPF_FILE                61
  99 #define KPF_SWAP                62
 100 #define KPF_MMAP_EXCLUSIVE      63
 101
 102 #define KPF_ALL_BITS            ((uint64_t)~0ULL)
 103 #define KPF_HACKERS_BITS        (0xffffULL << 32)
 104 #define KPF_OVERLOADED_BITS     (0xffffULL << 48)
 105 #define BIT(name)               (1ULL << KPF_##name)
 106 #define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
 107
 108 static const char * const page_flag_names[] = {
 109         [KPF_LOCKED]            = "L:locked",
 110         [KPF_ERROR]             = "E:error",
 111         [KPF_REFERENCED]        = "R:referenced",
 112         [KPF_UPTODATE]          = "U:uptodate",
 113         [KPF_DIRTY]             = "D:dirty",
 114         [KPF_LRU]               = "l:lru",
 115         [KPF_ACTIVE]            = "A:active",
 116         [KPF_SLAB]              = "S:slab",
 117         [KPF_WRITEBACK]         = "W:writeback",
 118         [KPF_RECLAIM]           = "I:reclaim",
 119         [KPF_BUDDY]             = "B:buddy",
 120
 121         [KPF_MMAP]              = "M:mmap",
 122         [KPF_ANON]              = "a:anonymous",
 123         [KPF_SWAPCACHE]         = "s:swapcache",
 124         [KPF_SWAPBACKED]        = "b:swapbacked",
 125         [KPF_COMPOUND_HEAD]     = "H:compound_head",
 126         [KPF_COMPOUND_TAIL]     = "T:compound_tail",
 127         [KPF_HUGE]              = "G:huge",
 128         [KPF_UNEVICTABLE]       = "u:unevictable",
 129         [KPF_HWPOISON]          = "X:hwpoison",
 130         [KPF_NOPAGE]            = "n:nopage",
 131         [KPF_KSM]               = "x:ksm",
 132         [KPF_THP]               = "t:thp",
 133         [KPF_BALLOON]           = "o:balloon",
 134         [KPF_ZERO_PAGE]         = "z:zero_page",
 135         [KPF_IDLE]              = "i:idle_page",
 136
 137         [KPF_RESERVED]          = "r:reserved",
 138         [KPF_MLOCKED]           = "m:mlocked",
 139         [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
 140         [KPF_PRIVATE]           = "P:private",
 141         [KPF_PRIVATE_2]         = "p:private_2",
 142         [KPF_OWNER_PRIVATE]     = "O:owner_private",
 143         [KPF_ARCH]              = "h:arch",
 144         [KPF_UNCACHED]          = "c:uncached",
 145         [KPF_SOFTDIRTY]         = "f:softdirty",
 146
 147         [KPF_READAHEAD]         = "I:readahead",
 148         [KPF_SLOB_FREE]         = "P:slob_free",
 149         [KPF_SLUB_FROZEN]       = "A:slub_frozen",
 150         [KPF_SLUB_DEBUG]        = "E:slub_debug",
 151
 152         [KPF_FILE]              = "F:file",
 153         [KPF_SWAP]              = "w:swap",
 154         [KPF_MMAP_EXCLUSIVE]    = "1:mmap_exclusive",
 155 };
 156
 157
 158 static const char * const debugfs_known_mountpoints[] = {
 159         "/sys/kernel/debug",
 160         "/debug",
 161         0,
 162 };
 163
 164 /*
 165  * data structures
 166  */
 167
 168 static int              opt_raw;        /* for kernel developers */
 169 static int              opt_list;       /* list pages (in ranges) */
 170 static int              opt_no_summary; /* don't show summary */
 171 static pid_t            opt_pid;        /* process to walk */
 172 const char *            opt_file;       /* file or directory path */
 173 static uint64_t         opt_cgroup;     /* cgroup inode */
 174 static int              opt_list_cgroup;/* list page cgroup */
 175
 176 #define MAX_ADDR_RANGES 1024
 177 static int              nr_addr_ranges;
 178 static unsigned long    opt_offset[MAX_ADDR_RANGES];
 179 static unsigned long    opt_size[MAX_ADDR_RANGES];
 180
 181 #define MAX_VMAS        10240
 182 static int              nr_vmas;
 183 static unsigned long    pg_start[MAX_VMAS];
 184 static unsigned long    pg_end[MAX_VMAS];
 185
 186 #define MAX_BIT_FILTERS 64
 187 static int              nr_bit_filters;
 188 static uint64_t         opt_mask[MAX_BIT_FILTERS];
 189 static uint64_t         opt_bits[MAX_BIT_FILTERS];
 190
 191 static int              page_size;
 192
 193 static int              pagemap_fd;
 194 static int              kpageflags_fd;
 195 static int              kpagecgroup_fd = -1;
 196
 197 static int              opt_hwpoison;
 198 static int              opt_unpoison;
 199
 200 static const char       *hwpoison_debug_fs;
 201 static int              hwpoison_inject_fd;
 202 static int              hwpoison_forget_fd;
 203
 204 #define HASH_SHIFT      13
 205 #define HASH_SIZE       (1 << HASH_SHIFT)
 206 #define HASH_MASK       (HASH_SIZE - 1)
 207 #define HASH_KEY(flags) (flags & HASH_MASK)
 208
 209 static unsigned long    total_pages;
 210 static unsigned long    nr_pages[HASH_SIZE];
 211 static uint64_t         page_flags[HASH_SIZE];
 212
 213
 214 /*
 215  * helper functions
 216  */
 217
 218 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 219
 220 #define min_t(type, x, y) ({                    \
 221         type __min1 = (x);                      \
 222         type __min2 = (y);                      \
 223         __min1 < __min2 ? __min1 : __min2; })
 224
 225 #define max_t(type, x, y) ({                    \
 226         type __max1 = (x);                      \
 227         type __max2 = (y);                      \
 228         __max1 > __max2 ? __max1 : __max2; })
 229
 230 static unsigned long pages2mb(unsigned long pages)
 231 {
 232         return (pages * page_size) >> 20;
 233 }
 234
 235 static void fatal(const char *x, ...)
 236 {
 237         va_list ap;
 238
 239         va_start(ap, x);
 240         vfprintf(stderr, x, ap);
 241         va_end(ap);
 242         exit(EXIT_FAILURE);
 243 }
 244
 245 static int checked_open(const char *pathname, int flags)
 246 {
 247         int fd = open(pathname, flags);
 248
 249         if (fd < 0) {
 250                 perror(pathname);
 251                 exit(EXIT_FAILURE);
 252         }
 253
 254         return fd;
 255 }
 256
 257 /*
 258  * pagemap/kpageflags routines
 259  */
 260
 261 static unsigned long do_u64_read(int fd, char *name,
 262                                  uint64_t *buf,
 263                                  unsigned long index,
 264                                  unsigned long count)
 265 {
 266         long bytes;
 267
 268         if (index > ULONG_MAX / 8)
 269                 fatal("index overflow: %lu\n", index);
 270
 271         bytes = pread(fd, buf, count * 8, (off_t)index * 8);
 272         if (bytes < 0) {
 273                 perror(name);
 274                 exit(EXIT_FAILURE);
 275         }
 276         if (bytes % 8)
 277                 fatal("partial read: %lu bytes\n", bytes);
 278
 279         return bytes / 8;
 280 }
 281
 282 static unsigned long kpageflags_read(uint64_t *buf,
 283                                      unsigned long index,
 284                                      unsigned long pages)
 285 {
 286         return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
 287 }
 288
 289 static unsigned long kpagecgroup_read(uint64_t *buf,
 290                                       unsigned long index,
 291                                       unsigned long pages)
 292 {
 293         if (kpagecgroup_fd < 0)
 294                 return pages;
 295
 296         return do_u64_read(kpagecgroup_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 static unsigned long pagemap_swap_offset(uint64_t val)
 319 {
 320         return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
 321 }
 322
 323 /*
 324  * page flag names
 325  */
 326
 327 static char *page_flag_name(uint64_t flags)
 328 {
 329         static char buf[65];
 330         int present;
 331         size_t i, j;
 332
 333         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 334                 present = (flags >> i) & 1;
 335                 if (!page_flag_names[i]) {
 336                         if (present)
 337                                 fatal("unknown flag bit %d\n", i);
 338                         continue;
 339                 }
 340                 buf[j++] = present ? page_flag_names[i][0] : '_';
 341         }
 342
 343         return buf;
 344 }
 345
 346 static char *page_flag_longname(uint64_t flags)
 347 {
 348         static char buf[1024];
 349         size_t i, n;
 350
 351         for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 352                 if (!page_flag_names[i])
 353                         continue;
 354                 if ((flags >> i) & 1)
 355                         n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 356                                         page_flag_names[i] + 2);
 357         }
 358         if (n)
 359                 n--;
 360         buf[n] = '\0';
 361
 362         return buf;
 363 }
 364
 365
 366 /*
 367  * page list and summary
 368  */
 369
 370 static void show_page_range(unsigned long voffset, unsigned long offset,
 371                             unsigned long size, uint64_t flags, uint64_t cgroup)
 372 {
 373         static uint64_t      flags0;
 374         static uint64_t      cgroup0;
 375         static unsigned long voff;
 376         static unsigned long index;
 377         static unsigned long count;
 378
 379         if (flags == flags0 && cgroup == cgroup0 && offset == index + count &&
 380             size && voffset == voff + count) {
 381                 count += size;
 382                 return;
 383         }
 384
 385         if (count) {
 386                 if (opt_pid)
 387                         printf("%lx\t", voff);
 388                 if (opt_file)
 389                         printf("%lu\t", voff);
 390                 if (opt_list_cgroup)
 391                         printf("@%llu\t", (unsigned long long)cgroup0);
 392                 printf("%lx\t%lx\t%s\n",
 393                                 index, count, page_flag_name(flags0));
 394         }
 395
 396         flags0 = flags;
 397         cgroup0= cgroup;
 398         index  = offset;
 399         voff   = voffset;
 400         count  = size;
 401 }
 402
 403 static void flush_page_range(void)
 404 {
 405         show_page_range(0, 0, 0, 0, 0);
 406 }
 407
 408 static void show_page(unsigned long voffset, unsigned long offset,
 409                       uint64_t flags, uint64_t cgroup)
 410 {
 411         if (opt_pid)
 412                 printf("%lx\t", voffset);
 413         if (opt_file)
 414                 printf("%lu\t", voffset);
 415         if (opt_list_cgroup)
 416                 printf("@%llu\t", (unsigned long long)cgroup);
 417         printf("%lx\t%s\n", offset, page_flag_name(flags));
 418 }
 419
 420 static void show_summary(void)
 421 {
 422         size_t i;
 423
 424         printf("             flags\tpage-count       MB"
 425                 "  symbolic-flags\t\t\tlong-symbolic-flags\n");
 426
 427         for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 428                 if (nr_pages[i])
 429                         printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 430                                 (unsigned long long)page_flags[i],
 431                                 nr_pages[i],
 432                                 pages2mb(nr_pages[i]),
 433                                 page_flag_name(page_flags[i]),
 434                                 page_flag_longname(page_flags[i]));
 435         }
 436
 437         printf("             total\t%10lu %8lu\n",
 438                         total_pages, pages2mb(total_pages));
 439 }
 440
 441
 442 /*
 443  * page flag filters
 444  */
 445
 446 static int bit_mask_ok(uint64_t flags)
 447 {
 448         int i;
 449
 450         for (i = 0; i < nr_bit_filters; i++) {
 451                 if (opt_bits[i] == KPF_ALL_BITS) {
 452                         if ((flags & opt_mask[i]) == 0)
 453                                 return 0;
 454                 } else {
 455                         if ((flags & opt_mask[i]) != opt_bits[i])
 456                                 return 0;
 457                 }
 458         }
 459
 460         return 1;
 461 }
 462
 463 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
 464 {
 465         /* SLOB/SLUB overload several page flags */
 466         if (flags & BIT(SLAB)) {
 467                 if (flags & BIT(PRIVATE))
 468                         flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 469                 if (flags & BIT(ACTIVE))
 470                         flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 471                 if (flags & BIT(ERROR))
 472                         flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 473         }
 474
 475         /* PG_reclaim is overloaded as PG_readahead in the read path */
 476         if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 477                 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 478
 479         if (pme & PM_SOFT_DIRTY)
 480                 flags |= BIT(SOFTDIRTY);
 481         if (pme & PM_FILE)
 482                 flags |= BIT(FILE);
 483         if (pme & PM_SWAP)
 484                 flags |= BIT(SWAP);
 485         if (pme & PM_MMAP_EXCLUSIVE)
 486                 flags |= BIT(MMAP_EXCLUSIVE);
 487
 488         return flags;
 489 }
 490
 491 static uint64_t well_known_flags(uint64_t flags)
 492 {
 493         /* hide flags intended only for kernel hacker */
 494         flags &= ~KPF_HACKERS_BITS;
 495
 496         /* hide non-hugeTLB compound pages */
 497         if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 498                 flags &= ~BITS_COMPOUND;
 499
 500         return flags;
 501 }
 502
 503 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 504 {
 505         if (opt_raw)
 506                 flags = expand_overloaded_flags(flags, pme);
 507         else
 508                 flags = well_known_flags(flags);
 509
 510         return flags;
 511 }
 512
 513 /*
 514  * page actions
 515  */
 516
 517 static void prepare_hwpoison_fd(void)
 518 {
 519         char buf[MAX_PATH + 1];
 520
 521         hwpoison_debug_fs = debugfs__mount();
 522         if (!hwpoison_debug_fs) {
 523                 perror("mount debugfs");
 524                 exit(EXIT_FAILURE);
 525         }
 526
 527         if (opt_hwpoison && !hwpoison_inject_fd) {
 528                 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 529                         hwpoison_debug_fs);
 530                 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 531         }
 532
 533         if (opt_unpoison && !hwpoison_forget_fd) {
 534                 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 535                         hwpoison_debug_fs);
 536                 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 537         }
 538 }
 539
 540 static int hwpoison_page(unsigned long offset)
 541 {
 542         char buf[100];
 543         int len;
 544
 545         len = sprintf(buf, "0x%lx\n", offset);
 546         len = write(hwpoison_inject_fd, buf, len);
 547         if (len < 0) {
 548                 perror("hwpoison inject");
 549                 return len;
 550         }
 551         return 0;
 552 }
 553
 554 static int unpoison_page(unsigned long offset)
 555 {
 556         char buf[100];
 557         int len;
 558
 559         len = sprintf(buf, "0x%lx\n", offset);
 560         len = write(hwpoison_forget_fd, buf, len);
 561         if (len < 0) {
 562                 perror("hwpoison forget");
 563                 return len;
 564         }
 565         return 0;
 566 }
 567
 568 /*
 569  * page frame walker
 570  */
 571
 572 static size_t hash_slot(uint64_t flags)
 573 {
 574         size_t k = HASH_KEY(flags);
 575         size_t i;
 576
 577         /* Explicitly reserve slot 0 for flags 0: the following logic
 578          * cannot distinguish an unoccupied slot from slot (flags==0).
 579          */
 580         if (flags == 0)
 581                 return 0;
 582
 583         /* search through the remaining (HASH_SIZE-1) slots */
 584         for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 585                 if (!k || k >= ARRAY_SIZE(page_flags))
 586                         k = 1;
 587                 if (page_flags[k] == 0) {
 588                         page_flags[k] = flags;
 589                         return k;
 590                 }
 591                 if (page_flags[k] == flags)
 592                         return k;
 593         }
 594
 595         fatal("hash table full: bump up HASH_SHIFT?\n");
 596         exit(EXIT_FAILURE);
 597 }
 598
 599 static void add_page(unsigned long voffset, unsigned long offset,
 600                      uint64_t flags, uint64_t cgroup, uint64_t pme)
 601 {
 602         flags = kpageflags_flags(flags, pme);
 603
 604         if (!bit_mask_ok(flags))
 605                 return;
 606
 607         if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
 608                 return;
 609
 610         if (opt_hwpoison)
 611                 hwpoison_page(offset);
 612         if (opt_unpoison)
 613                 unpoison_page(offset);
 614
 615         if (opt_list == 1)
 616                 show_page_range(voffset, offset, 1, flags, cgroup);
 617         else if (opt_list == 2)
 618                 show_page(voffset, offset, flags, cgroup);
 619
 620         nr_pages[hash_slot(flags)]++;
 621         total_pages++;
 622 }
 623
 624 #define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 625 static void walk_pfn(unsigned long voffset,
 626                      unsigned long index,
 627                      unsigned long count,
 628                      uint64_t pme)
 629 {
 630         uint64_t buf[KPAGEFLAGS_BATCH];
 631         uint64_t cgi[KPAGEFLAGS_BATCH];
 632         unsigned long batch;
 633         unsigned long pages;
 634         unsigned long i;
 635
 636         /*
 637          * kpagecgroup_read() reads only if kpagecgroup were opened, but
 638          * /proc/kpagecgroup might even not exist, so it's better to fill
 639          * them with zeros here.
 640          */
 641         if (count == 1)
 642                 cgi[0] = 0;
 643         else
 644                 memset(cgi, 0, sizeof cgi);
 645
 646         while (count) {
 647                 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 648                 pages = kpageflags_read(buf, index, batch);
 649                 if (pages == 0)
 650                         break;
 651
 652                 if (kpagecgroup_read(cgi, index, pages) != pages)
 653                         fatal("kpagecgroup returned fewer pages than expected");
 654
 655                 for (i = 0; i < pages; i++)
 656                         add_page(voffset + i, index + i, buf[i], cgi[i], pme);
 657
 658                 index += pages;
 659                 count -= pages;
 660         }
 661 }
 662
 663 static void walk_swap(unsigned long voffset, uint64_t pme)
 664 {
 665         uint64_t flags = kpageflags_flags(0, pme);
 666
 667         if (!bit_mask_ok(flags))
 668                 return;
 669
 670         if (opt_cgroup)
 671                 return;
 672
 673         if (opt_list == 1)
 674                 show_page_range(voffset, pagemap_swap_offset(pme), 1, flags, 0);
 675         else if (opt_list == 2)
 676                 show_page(voffset, pagemap_swap_offset(pme), flags, 0);
 677
 678         nr_pages[hash_slot(flags)]++;
 679         total_pages++;
 680 }
 681
 682 #define PAGEMAP_BATCH   (64 << 10)
 683 static void walk_vma(unsigned long index, unsigned long count)
 684 {
 685         uint64_t buf[PAGEMAP_BATCH];
 686         unsigned long batch;
 687         unsigned long pages;
 688         unsigned long pfn;
 689         unsigned long i;
 690
 691         while (count) {
 692                 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 693                 pages = pagemap_read(buf, index, batch);
 694                 if (pages == 0)
 695                         break;
 696
 697                 for (i = 0; i < pages; i++) {
 698                         pfn = pagemap_pfn(buf[i]);
 699                         if (pfn)
 700                                 walk_pfn(index + i, pfn, 1, buf[i]);
 701                         if (buf[i] & PM_SWAP)
 702                                 walk_swap(index + i, buf[i]);
 703                 }
 704
 705                 index += pages;
 706                 count -= pages;
 707         }
 708 }
 709
 710 static void walk_task(unsigned long index, unsigned long count)
 711 {
 712         const unsigned long end = index + count;
 713         unsigned long start;
 714         int i = 0;
 715
 716         while (index < end) {
 717
 718                 while (pg_end[i] <= index)
 719                         if (++i >= nr_vmas)
 720                                 return;
 721                 if (pg_start[i] >= end)
 722                         return;
 723
 724                 start = max_t(unsigned long, pg_start[i], index);
 725                 index = min_t(unsigned long, pg_end[i], end);
 726
 727                 assert(start < index);
 728                 walk_vma(start, index - start);
 729         }
 730 }
 731
 732 static void add_addr_range(unsigned long offset, unsigned long size)
 733 {
 734         if (nr_addr_ranges >= MAX_ADDR_RANGES)
 735                 fatal("too many addr ranges\n");
 736
 737         opt_offset[nr_addr_ranges] = offset;
 738         opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 739         nr_addr_ranges++;
 740 }
 741
 742 static void walk_addr_ranges(void)
 743 {
 744         int i;
 745
 746         kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 747
 748         if (!nr_addr_ranges)
 749                 add_addr_range(0, ULONG_MAX);
 750
 751         for (i = 0; i < nr_addr_ranges; i++)
 752                 if (!opt_pid)
 753                         walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 754                 else
 755                         walk_task(opt_offset[i], opt_size[i]);
 756
 757         close(kpageflags_fd);
 758 }
 759
 760
 761 /*
 762  * user interface
 763  */
 764
 765 static const char *page_flag_type(uint64_t flag)
 766 {
 767         if (flag & KPF_HACKERS_BITS)
 768                 return "(r)";
 769         if (flag & KPF_OVERLOADED_BITS)
 770                 return "(o)";
 771         return "   ";
 772 }
 773
 774 static void usage(void)
 775 {
 776         size_t i, j;
 777
 778         printf(
 779 "page-types [options]\n"
 780 "            -r|--raw                   Raw mode, for kernel developers\n"
 781 "            -d|--describe flags        Describe flags\n"
 782 "            -a|--addr    addr-spec     Walk a range of pages\n"
 783 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
 784 "            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
 785 "            -p|--pid     pid           Walk process address space\n"
 786 "            -f|--file    filename      Walk file address space\n"
 787 "            -l|--list                  Show page details in ranges\n"
 788 "            -L|--list-each             Show page details one by one\n"
 789 "            -C|--list-cgroup           Show cgroup inode for pages\n"
 790 "            -N|--no-summary            Don't show summary info\n"
 791 "            -X|--hwpoison              hwpoison pages\n"
 792 "            -x|--unpoison              unpoison pages\n"
 793 "            -h|--help                  Show this usage message\n"
 794 "flags:\n"
 795 "            0x10                       bitfield format, e.g.\n"
 796 "            anon                       bit-name, e.g.\n"
 797 "            0x10,anon                  comma-separated list, e.g.\n"
 798 "addr-spec:\n"
 799 "            N                          one page at offset N (unit: pages)\n"
 800 "            N+M                        pages range from N to N+M-1\n"
 801 "            N,M                        pages range from N to M-1\n"
 802 "            N,                         pages range from N to end\n"
 803 "            ,M                         pages range from 0 to M-1\n"
 804 "bits-spec:\n"
 805 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 806 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 807 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 808 "            =bit1,bit2                 flags == (bit1|bit2)\n"
 809 "bit-names:\n"
 810         );
 811
 812         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 813                 if (!page_flag_names[i])
 814                         continue;
 815                 printf("%16s%s", page_flag_names[i] + 2,
 816                                  page_flag_type(1ULL << i));
 817                 if (++j > 3) {
 818                         j = 0;
 819                         putchar('\n');
 820                 }
 821         }
 822         printf("\n                                   "
 823                 "(r) raw mode bits  (o) overloaded bits\n");
 824 }
 825
 826 static unsigned long long parse_number(const char *str)
 827 {
 828         unsigned long long n;
 829
 830         n = strtoll(str, NULL, 0);
 831
 832         if (n == 0 && str[0] != '0')
 833                 fatal("invalid name or number: %s\n", str);
 834
 835         return n;
 836 }
 837
 838 static void parse_pid(const char *str)
 839 {
 840         FILE *file;
 841         char buf[5000];
 842
 843         opt_pid = parse_number(str);
 844
 845         sprintf(buf, "/proc/%d/pagemap", opt_pid);
 846         pagemap_fd = checked_open(buf, O_RDONLY);
 847
 848         sprintf(buf, "/proc/%d/maps", opt_pid);
 849         file = fopen(buf, "r");
 850         if (!file) {
 851                 perror(buf);
 852                 exit(EXIT_FAILURE);
 853         }
 854
 855         while (fgets(buf, sizeof(buf), file) != NULL) {
 856                 unsigned long vm_start;
 857                 unsigned long vm_end;
 858                 unsigned long long pgoff;
 859                 int major, minor;
 860                 char r, w, x, s;
 861                 unsigned long ino;
 862                 int n;
 863
 864                 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 865                            &vm_start,
 866                            &vm_end,
 867                            &r, &w, &x, &s,
 868                            &pgoff,
 869                            &major, &minor,
 870                            &ino);
 871                 if (n < 10) {
 872                         fprintf(stderr, "unexpected line: %s\n", buf);
 873                         continue;
 874                 }
 875                 pg_start[nr_vmas] = vm_start / page_size;
 876                 pg_end[nr_vmas] = vm_end / page_size;
 877                 if (++nr_vmas >= MAX_VMAS) {
 878                         fprintf(stderr, "too many VMAs\n");
 879                         break;
 880                 }
 881         }
 882         fclose(file);
 883 }
 884
 885 static void show_file(const char *name, const struct stat *st)
 886 {
 887         unsigned long long size = st->st_size;
 888         char atime[64], mtime[64];
 889         long now = time(NULL);
 890
 891         printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 892                         name, (unsigned)st->st_ino,
 893                         size, (size + page_size - 1) / page_size);
 894
 895         strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 896         strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 897
 898         printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 899                         mtime, now - st->st_mtime,
 900                         atime, now - st->st_atime);
 901 }
 902
 903 static sigjmp_buf sigbus_jmp;
 904
 905 static void * volatile sigbus_addr;
 906
 907 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 908 {
 909         (void)sig;
 910         (void)ucontex;
 911         sigbus_addr = info ? info->si_addr : NULL;
 912         siglongjmp(sigbus_jmp, 1);
 913 }
 914
 915 static struct sigaction sigbus_action = {
 916         .sa_sigaction = sigbus_handler,
 917         .sa_flags = SA_SIGINFO,
 918 };
 919
 920 static void walk_file(const char *name, const struct stat *st)
 921 {
 922         uint8_t vec[PAGEMAP_BATCH];
 923         uint64_t buf[PAGEMAP_BATCH], flags;
 924         uint64_t cgroup = 0;
 925         unsigned long nr_pages, pfn, i;
 926         off_t off, end = st->st_size;
 927         int fd;
 928         ssize_t len;
 929         void *ptr;
 930         int first = 1;
 931
 932         fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
 933
 934         for (off = 0; off < end; off += len) {
 935                 nr_pages = (end - off + page_size - 1) / page_size;
 936                 if (nr_pages > PAGEMAP_BATCH)
 937                         nr_pages = PAGEMAP_BATCH;
 938                 len = nr_pages * page_size;
 939
 940                 ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 941                 if (ptr == MAP_FAILED)
 942                         fatal("mmap failed: %s", name);
 943
 944                 /* determine cached pages */
 945                 if (mincore(ptr, len, vec))
 946                         fatal("mincore failed: %s", name);
 947
 948                 /* turn off readahead */
 949                 if (madvise(ptr, len, MADV_RANDOM))
 950                         fatal("madvice failed: %s", name);
 951
 952                 if (sigsetjmp(sigbus_jmp, 1)) {
 953                         end = off + sigbus_addr ? sigbus_addr - ptr : 0;
 954                         fprintf(stderr, "got sigbus at offset %lld: %s\n",
 955                                         (long long)end, name);
 956                         goto got_sigbus;
 957                 }
 958
 959                 /* populate ptes */
 960                 for (i = 0; i < nr_pages ; i++) {
 961                         if (vec[i] & 1)
 962                                 (void)*(volatile int *)(ptr + i * page_size);
 963                 }
 964 got_sigbus:
 965
 966                 /* turn off harvesting reference bits */
 967                 if (madvise(ptr, len, MADV_SEQUENTIAL))
 968                         fatal("madvice failed: %s", name);
 969
 970                 if (pagemap_read(buf, (unsigned long)ptr / page_size,
 971                                         nr_pages) != nr_pages)
 972                         fatal("cannot read pagemap");
 973
 974                 munmap(ptr, len);
 975
 976                 for (i = 0; i < nr_pages; i++) {
 977                         pfn = pagemap_pfn(buf[i]);
 978                         if (!pfn)
 979                                 continue;
 980                         if (!kpageflags_read(&flags, pfn, 1))
 981                                 continue;
 982                         if (!kpagecgroup_read(&cgroup, pfn, 1))
 983                                 fatal("kpagecgroup_read failed");
 984                         if (first && opt_list) {
 985                                 first = 0;
 986                                 flush_page_range();
 987                                 show_file(name, st);
 988                         }
 989                         add_page(off / page_size + i, pfn,
 990                                  flags, cgroup, buf[i]);
 991                 }
 992         }
 993
 994         close(fd);
 995 }
 996
 997 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
 998 {
 999         (void)f;
1000         switch (type) {
1001         case FTW_F:
1002                 if (S_ISREG(st->st_mode))
1003                         walk_file(name, st);
1004                 break;
1005         case FTW_DNR:
1006                 fprintf(stderr, "cannot read dir: %s\n", name);
1007                 break;
1008         }
1009         return 0;
1010 }
1011
1012 static void walk_page_cache(void)
1013 {
1014         struct stat st;
1015
1016         kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
1017         pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1018         sigaction(SIGBUS, &sigbus_action, NULL);
1019
1020         if (stat(opt_file, &st))
1021                 fatal("stat failed: %s\n", opt_file);
1022
1023         if (S_ISREG(st.st_mode)) {
1024                 walk_file(opt_file, &st);
1025         } else if (S_ISDIR(st.st_mode)) {
1026                 /* do not follow symlinks and mountpoints */
1027                 if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1028                         fatal("nftw failed: %s\n", opt_file);
1029         } else
1030                 fatal("unhandled file type: %s\n", opt_file);
1031
1032         close(kpageflags_fd);
1033         close(pagemap_fd);
1034         signal(SIGBUS, SIG_DFL);
1035 }
1036
1037 static void parse_file(const char *name)
1038 {
1039         opt_file = name;
1040 }
1041
1042 static void parse_cgroup(const char *path)
1043 {
1044         if (path[0] == '@') {
1045                 opt_cgroup = parse_number(path + 1);
1046                 return;
1047         }
1048
1049         struct stat st;
1050
1051         if (stat(path, &st))
1052                 fatal("stat failed: %s: %m\n", path);
1053
1054         if (!S_ISDIR(st.st_mode))
1055                 fatal("cgroup supposed to be a directory: %s\n", path);
1056
1057         opt_cgroup = st.st_ino;
1058 }
1059
1060 static void parse_addr_range(const char *optarg)
1061 {
1062         unsigned long offset;
1063         unsigned long size;
1064         char *p;
1065
1066         p = strchr(optarg, ',');
1067         if (!p)
1068                 p = strchr(optarg, '+');
1069
1070         if (p == optarg) {
1071                 offset = 0;
1072                 size   = parse_number(p + 1);
1073         } else if (p) {
1074                 offset = parse_number(optarg);
1075                 if (p[1] == '\0')
1076                         size = ULONG_MAX;
1077                 else {
1078                         size = parse_number(p + 1);
1079                         if (*p == ',') {
1080                                 if (size < offset)
1081                                         fatal("invalid range: %lu,%lu\n",
1082                                                         offset, size);
1083                                 size -= offset;
1084                         }
1085                 }
1086         } else {
1087                 offset = parse_number(optarg);
1088                 size   = 1;
1089         }
1090
1091         add_addr_range(offset, size);
1092 }
1093
1094 static void add_bits_filter(uint64_t mask, uint64_t bits)
1095 {
1096         if (nr_bit_filters >= MAX_BIT_FILTERS)
1097                 fatal("too much bit filters\n");
1098
1099         opt_mask[nr_bit_filters] = mask;
1100         opt_bits[nr_bit_filters] = bits;
1101         nr_bit_filters++;
1102 }
1103
1104 static uint64_t parse_flag_name(const char *str, int len)
1105 {
1106         size_t i;
1107
1108         if (!*str || !len)
1109                 return 0;
1110
1111         if (len <= 8 && !strncmp(str, "compound", len))
1112                 return BITS_COMPOUND;
1113
1114         for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1115                 if (!page_flag_names[i])
1116                         continue;
1117                 if (!strncmp(str, page_flag_names[i] + 2, len))
1118                         return 1ULL << i;
1119         }
1120
1121         return parse_number(str);
1122 }
1123
1124 static uint64_t parse_flag_names(const char *str, int all)
1125 {
1126         const char *p    = str;
1127         uint64_t   flags = 0;
1128
1129         while (1) {
1130                 if (*p == ',' || *p == '=' || *p == '\0') {
1131                         if ((*str != '~') || (*str == '~' && all && *++str))
1132                                 flags |= parse_flag_name(str, p - str);
1133                         if (*p != ',')
1134                                 break;
1135                         str = p + 1;
1136                 }
1137                 p++;
1138         }
1139
1140         return flags;
1141 }
1142
1143 static void parse_bits_mask(const char *optarg)
1144 {
1145         uint64_t mask;
1146         uint64_t bits;
1147         const char *p;
1148
1149         p = strchr(optarg, '=');
1150         if (p == optarg) {
1151                 mask = KPF_ALL_BITS;
1152                 bits = parse_flag_names(p + 1, 0);
1153         } else if (p) {
1154                 mask = parse_flag_names(optarg, 0);
1155                 bits = parse_flag_names(p + 1, 0);
1156         } else if (strchr(optarg, '~')) {
1157                 mask = parse_flag_names(optarg, 1);
1158                 bits = parse_flag_names(optarg, 0);
1159         } else {
1160                 mask = parse_flag_names(optarg, 0);
1161                 bits = KPF_ALL_BITS;
1162         }
1163
1164         add_bits_filter(mask, bits);
1165 }
1166
1167 static void describe_flags(const char *optarg)
1168 {
1169         uint64_t flags = parse_flag_names(optarg, 0);
1170
1171         printf("0x%016llx\t%s\t%s\n",
1172                 (unsigned long long)flags,
1173                 page_flag_name(flags),
1174                 page_flag_longname(flags));
1175 }
1176
1177 static const struct option opts[] = {
1178         { "raw"       , 0, NULL, 'r' },
1179         { "pid"       , 1, NULL, 'p' },
1180         { "file"      , 1, NULL, 'f' },
1181         { "addr"      , 1, NULL, 'a' },
1182         { "bits"      , 1, NULL, 'b' },
1183         { "cgroup"    , 1, NULL, 'c' },
1184         { "describe"  , 1, NULL, 'd' },
1185         { "list"      , 0, NULL, 'l' },
1186         { "list-each" , 0, NULL, 'L' },
1187         { "list-cgroup", 0, NULL, 'C' },
1188         { "no-summary", 0, NULL, 'N' },
1189         { "hwpoison"  , 0, NULL, 'X' },
1190         { "unpoison"  , 0, NULL, 'x' },
1191         { "help"      , 0, NULL, 'h' },
1192         { NULL        , 0, NULL, 0 }
1193 };
1194
1195 int main(int argc, char *argv[])
1196 {
1197         int c;
1198
1199         page_size = getpagesize();
1200
1201         while ((c = getopt_long(argc, argv,
1202                                 "rp:f:a:b:d:c:ClLNXxh", opts, NULL)) != -1) {
1203                 switch (c) {
1204                 case 'r':
1205                         opt_raw = 1;
1206                         break;
1207                 case 'p':
1208                         parse_pid(optarg);
1209                         break;
1210                 case 'f':
1211                         parse_file(optarg);
1212                         break;
1213                 case 'a':
1214                         parse_addr_range(optarg);
1215                         break;
1216                 case 'b':
1217                         parse_bits_mask(optarg);
1218                         break;
1219                 case 'c':
1220                         parse_cgroup(optarg);
1221                         break;
1222                 case 'C':
1223                         opt_list_cgroup = 1;
1224                         break;
1225                 case 'd':
1226                         describe_flags(optarg);
1227                         exit(0);
1228                 case 'l':
1229                         opt_list = 1;
1230                         break;
1231                 case 'L':
1232                         opt_list = 2;
1233                         break;
1234                 case 'N':
1235                         opt_no_summary = 1;
1236                         break;
1237                 case 'X':
1238                         opt_hwpoison = 1;
1239                         prepare_hwpoison_fd();
1240                         break;
1241                 case 'x':
1242                         opt_unpoison = 1;
1243                         prepare_hwpoison_fd();
1244                         break;
1245                 case 'h':
1246                         usage();
1247                         exit(0);
1248                 default:
1249                         usage();
1250                         exit(1);
1251                 }
1252         }
1253
1254         if (opt_cgroup || opt_list_cgroup)
1255                 kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1256
1257         if (opt_list && opt_pid)
1258                 printf("voffset\t");
1259         if (opt_list && opt_file)
1260                 printf("foffset\t");
1261         if (opt_list && opt_list_cgroup)
1262                 printf("cgroup\t");
1263         if (opt_list == 1)
1264                 printf("offset\tlen\tflags\n");
1265         if (opt_list == 2)
1266                 printf("offset\tflags\n");
1267
1268         if (opt_file)
1269                 walk_page_cache();
1270         else
1271                 walk_addr_ranges();
1272
1273         if (opt_list == 1)
1274                 flush_page_range();
1275
1276         if (opt_no_summary)
1277                 return 0;
1278
1279         if (opt_list)
1280                 printf("\n\n");
1281
1282         show_summary();
1283
1284         return 0;
1285 }