linux/tools/vm/page-types.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * page-types: Tool for querying page flags
   4 *
   5 * Copyright (C) 2009 Intel corporation
   6 *
   7 * Authors: Wu Fengguang <fengguang.wu@intel.com>
   8 */
   9
  10#define _FILE_OFFSET_BITS 64
  11#define _GNU_SOURCE
  12#include <stdio.h>
  13#include <stdlib.h>
  14#include <unistd.h>
  15#include <stdint.h>
  16#include <stdarg.h>
  17#include <string.h>
  18#include <getopt.h>
  19#include <limits.h>
  20#include <assert.h>
  21#include <ftw.h>
  22#include <time.h>
  23#include <setjmp.h>
  24#include <signal.h>
  25#include <sys/types.h>
  26#include <sys/errno.h>
  27#include <sys/fcntl.h>
  28#include <sys/mount.h>
  29#include <sys/statfs.h>
  30#include <sys/mman.h>
  31#include "../../include/uapi/linux/magic.h"
  32#include "../../include/uapi/linux/kernel-page-flags.h"
  33#include <api/fs/fs.h>
  34
  35#ifndef MAX_PATH
  36# define MAX_PATH 256
  37#endif
  38
  39#ifndef STR
  40# define _STR(x) #x
  41# define STR(x) _STR(x)
  42#endif
  43
  44/*
  45 * pagemap kernel ABI bits
  46 */
  47
  48#define PM_ENTRY_BYTES          8
  49#define PM_PFRAME_BITS          55
  50#define PM_PFRAME_MASK          ((1LL << PM_PFRAME_BITS) - 1)
  51#define PM_PFRAME(x)            ((x) & PM_PFRAME_MASK)
  52#define MAX_SWAPFILES_SHIFT     5
  53#define PM_SWAP_OFFSET(x)       (((x) & PM_PFRAME_MASK) >> MAX_SWAPFILES_SHIFT)
  54#define PM_SOFT_DIRTY           (1ULL << 55)
  55#define PM_MMAP_EXCLUSIVE       (1ULL << 56)
  56#define PM_FILE                 (1ULL << 61)
  57#define PM_SWAP                 (1ULL << 62)
  58#define PM_PRESENT              (1ULL << 63)
  59
  60/*
  61 * kernel page flags
  62 */
  63
  64#define KPF_BYTES               8
  65#define PROC_KPAGEFLAGS         "/proc/kpageflags"
  66#define PROC_KPAGECOUNT         "/proc/kpagecount"
  67#define PROC_KPAGECGROUP        "/proc/kpagecgroup"
  68
  69#define SYS_KERNEL_MM_PAGE_IDLE "/sys/kernel/mm/page_idle/bitmap"
  70
  71/* [32-] kernel hacking assistances */
  72#define KPF_RESERVED            32
  73#define KPF_MLOCKED             33
  74#define KPF_MAPPEDTODISK        34
  75#define KPF_PRIVATE             35
  76#define KPF_PRIVATE_2           36
  77#define KPF_OWNER_PRIVATE       37
  78#define KPF_ARCH                38
  79#define KPF_UNCACHED            39
  80#define KPF_SOFTDIRTY           40
  81#define KPF_ARCH_2              41
  82
  83/* [48-] take some arbitrary free slots for expanding overloaded flags
  84 * not part of kernel API
  85 */
  86#define KPF_READAHEAD           48
  87#define KPF_SLOB_FREE           49
  88#define KPF_SLUB_FROZEN         50
  89#define KPF_SLUB_DEBUG          51
  90#define KPF_FILE                61
  91#define KPF_SWAP                62
  92#define KPF_MMAP_EXCLUSIVE      63
  93
  94#define KPF_ALL_BITS            ((uint64_t)~0ULL)
  95#define KPF_HACKERS_BITS        (0xffffULL << 32)
  96#define KPF_OVERLOADED_BITS     (0xffffULL << 48)
  97#define BIT(name)               (1ULL << KPF_##name)
  98#define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
  99
 100static const char * const page_flag_names[] = {
 101        [KPF_LOCKED]            = "L:locked",
 102        [KPF_ERROR]             = "E:error",
 103        [KPF_REFERENCED]        = "R:referenced",
 104        [KPF_UPTODATE]          = "U:uptodate",
 105        [KPF_DIRTY]             = "D:dirty",
 106        [KPF_LRU]               = "l:lru",
 107        [KPF_ACTIVE]            = "A:active",
 108        [KPF_SLAB]              = "S:slab",
 109        [KPF_WRITEBACK]         = "W:writeback",
 110        [KPF_RECLAIM]           = "I:reclaim",
 111        [KPF_BUDDY]             = "B:buddy",
 112
 113        [KPF_MMAP]              = "M:mmap",
 114        [KPF_ANON]              = "a:anonymous",
 115        [KPF_SWAPCACHE]         = "s:swapcache",
 116        [KPF_SWAPBACKED]        = "b:swapbacked",
 117        [KPF_COMPOUND_HEAD]     = "H:compound_head",
 118        [KPF_COMPOUND_TAIL]     = "T:compound_tail",
 119        [KPF_HUGE]              = "G:huge",
 120        [KPF_UNEVICTABLE]       = "u:unevictable",
 121        [KPF_HWPOISON]          = "X:hwpoison",
 122        [KPF_NOPAGE]            = "n:nopage",
 123        [KPF_KSM]               = "x:ksm",
 124        [KPF_THP]               = "t:thp",
 125        [KPF_OFFLINE]           = "o:offline",
 126        [KPF_PGTABLE]           = "g:pgtable",
 127        [KPF_ZERO_PAGE]         = "z:zero_page",
 128        [KPF_IDLE]              = "i:idle_page",
 129
 130        [KPF_RESERVED]          = "r:reserved",
 131        [KPF_MLOCKED]           = "m:mlocked",
 132        [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
 133        [KPF_PRIVATE]           = "P:private",
 134        [KPF_PRIVATE_2]         = "p:private_2",
 135        [KPF_OWNER_PRIVATE]     = "O:owner_private",
 136        [KPF_ARCH]              = "h:arch",
 137        [KPF_UNCACHED]          = "c:uncached",
 138        [KPF_SOFTDIRTY]         = "f:softdirty",
 139        [KPF_ARCH_2]            = "H:arch_2",
 140
 141        [KPF_READAHEAD]         = "I:readahead",
 142        [KPF_SLOB_FREE]         = "P:slob_free",
 143        [KPF_SLUB_FROZEN]       = "A:slub_frozen",
 144        [KPF_SLUB_DEBUG]        = "E:slub_debug",
 145
 146        [KPF_FILE]              = "F:file",
 147        [KPF_SWAP]              = "w:swap",
 148        [KPF_MMAP_EXCLUSIVE]    = "1:mmap_exclusive",
 149};
 150
 151
 152/*
 153 * data structures
 154 */
 155
 156static int              opt_raw;        /* for kernel developers */
 157static int              opt_list;       /* list pages (in ranges) */
 158static int              opt_mark_idle;  /* set accessed bit */
 159static int              opt_no_summary; /* don't show summary */
 160static pid_t            opt_pid;        /* process to walk */
 161const char              *opt_file;      /* file or directory path */
 162static uint64_t         opt_cgroup;     /* cgroup inode */
 163static int              opt_list_cgroup;/* list page cgroup */
 164static int              opt_list_mapcnt;/* list page map count */
 165static const char       *opt_kpageflags;/* kpageflags file to parse */
 166
 167#define MAX_ADDR_RANGES 1024
 168static int              nr_addr_ranges;
 169static unsigned long    opt_offset[MAX_ADDR_RANGES];
 170static unsigned long    opt_size[MAX_ADDR_RANGES];
 171
 172#define MAX_VMAS        10240
 173static int              nr_vmas;
 174static unsigned long    pg_start[MAX_VMAS];
 175static unsigned long    pg_end[MAX_VMAS];
 176
 177#define MAX_BIT_FILTERS 64
 178static int              nr_bit_filters;
 179static uint64_t         opt_mask[MAX_BIT_FILTERS];
 180static uint64_t         opt_bits[MAX_BIT_FILTERS];
 181
 182static int              page_size;
 183
 184static int              pagemap_fd;
 185static int              kpageflags_fd;
 186static int              kpagecount_fd = -1;
 187static int              kpagecgroup_fd = -1;
 188static int              page_idle_fd = -1;
 189
 190static int              opt_hwpoison;
 191static int              opt_unpoison;
 192
 193static const char       *hwpoison_debug_fs;
 194static int              hwpoison_inject_fd;
 195static int              hwpoison_forget_fd;
 196
 197#define HASH_SHIFT      13
 198#define HASH_SIZE       (1 << HASH_SHIFT)
 199#define HASH_MASK       (HASH_SIZE - 1)
 200#define HASH_KEY(flags) (flags & HASH_MASK)
 201
 202static unsigned long    total_pages;
 203static unsigned long    nr_pages[HASH_SIZE];
 204static uint64_t         page_flags[HASH_SIZE];
 205
 206
 207/*
 208 * helper functions
 209 */
 210
 211#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 212
 213#define min_t(type, x, y) ({                    \
 214        type __min1 = (x);                      \
 215        type __min2 = (y);                      \
 216        __min1 < __min2 ? __min1 : __min2; })
 217
 218#define max_t(type, x, y) ({                    \
 219        type __max1 = (x);                      \
 220        type __max2 = (y);                      \
 221        __max1 > __max2 ? __max1 : __max2; })
 222
 223static unsigned long pages2mb(unsigned long pages)
 224{
 225        return (pages * page_size) >> 20;
 226}
 227
 228static void fatal(const char *x, ...)
 229{
 230        va_list ap;
 231
 232        va_start(ap, x);
 233        vfprintf(stderr, x, ap);
 234        va_end(ap);
 235        exit(EXIT_FAILURE);
 236}
 237
 238static int checked_open(const char *pathname, int flags)
 239{
 240        int fd = open(pathname, flags);
 241
 242        if (fd < 0) {
 243                perror(pathname);
 244                exit(EXIT_FAILURE);
 245        }
 246
 247        return fd;
 248}
 249
 250/*
 251 * pagemap/kpageflags routines
 252 */
 253
 254static unsigned long do_u64_read(int fd, const char *name,
 255                                 uint64_t *buf,
 256                                 unsigned long index,
 257                                 unsigned long count)
 258{
 259        long bytes;
 260
 261        if (index > ULONG_MAX / 8)
 262                fatal("index overflow: %lu\n", index);
 263
 264        bytes = pread(fd, buf, count * 8, (off_t)index * 8);
 265        if (bytes < 0) {
 266                perror(name);
 267                exit(EXIT_FAILURE);
 268        }
 269        if (bytes % 8)
 270                fatal("partial read: %lu bytes\n", bytes);
 271
 272        return bytes / 8;
 273}
 274
 275static unsigned long kpageflags_read(uint64_t *buf,
 276                                     unsigned long index,
 277                                     unsigned long pages)
 278{
 279        return do_u64_read(kpageflags_fd, opt_kpageflags, buf, index, pages);
 280}
 281
 282static unsigned long kpagecgroup_read(uint64_t *buf,
 283                                      unsigned long index,
 284                                      unsigned long pages)
 285{
 286        if (kpagecgroup_fd < 0)
 287                return pages;
 288
 289        return do_u64_read(kpagecgroup_fd, opt_kpageflags, buf, index, pages);
 290}
 291
 292static unsigned long kpagecount_read(uint64_t *buf,
 293                                     unsigned long index,
 294                                     unsigned long pages)
 295{
 296        return kpagecount_fd < 0 ? pages :
 297                do_u64_read(kpagecount_fd, PROC_KPAGECOUNT,
 298                            buf, index, pages);
 299}
 300
 301static unsigned long pagemap_read(uint64_t *buf,
 302                                  unsigned long index,
 303                                  unsigned long pages)
 304{
 305        return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
 306}
 307
 308static unsigned long pagemap_pfn(uint64_t val)
 309{
 310        unsigned long pfn;
 311
 312        if (val & PM_PRESENT)
 313                pfn = PM_PFRAME(val);
 314        else
 315                pfn = 0;
 316
 317        return pfn;
 318}
 319
 320static unsigned long pagemap_swap_offset(uint64_t val)
 321{
 322        return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
 323}
 324
 325/*
 326 * page flag names
 327 */
 328
 329static char *page_flag_name(uint64_t flags)
 330{
 331        static char buf[65];
 332        int present;
 333        size_t i, j;
 334
 335        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 336                present = (flags >> i) & 1;
 337                if (!page_flag_names[i]) {
 338                        if (present)
 339                                fatal("unknown flag bit %d\n", i);
 340                        continue;
 341                }
 342                buf[j++] = present ? page_flag_names[i][0] : '_';
 343        }
 344
 345        return buf;
 346}
 347
 348static char *page_flag_longname(uint64_t flags)
 349{
 350        static char buf[1024];
 351        size_t i, n;
 352
 353        for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 354                if (!page_flag_names[i])
 355                        continue;
 356                if ((flags >> i) & 1)
 357                        n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 358                                        page_flag_names[i] + 2);
 359        }
 360        if (n)
 361                n--;
 362        buf[n] = '\0';
 363
 364        return buf;
 365}
 366
 367
 368/*
 369 * page list and summary
 370 */
 371
 372static void show_page_range(unsigned long voffset, unsigned long offset,
 373                            unsigned long size, uint64_t flags,
 374                            uint64_t cgroup, uint64_t mapcnt)
 375{
 376        static uint64_t      flags0;
 377        static uint64_t      cgroup0;
 378        static uint64_t      mapcnt0;
 379        static unsigned long voff;
 380        static unsigned long index;
 381        static unsigned long count;
 382
 383        if (flags == flags0 && cgroup == cgroup0 && mapcnt == mapcnt0 &&
 384            offset == index + count && size && voffset == voff + count) {
 385                count += size;
 386                return;
 387        }
 388
 389        if (count) {
 390                if (opt_pid)
 391                        printf("%lx\t", voff);
 392                if (opt_file)
 393                        printf("%lx\t", voff);
 394                if (opt_list_cgroup)
 395                        printf("@%llu\t", (unsigned long long)cgroup0);
 396                if (opt_list_mapcnt)
 397                        printf("%lu\t", mapcnt0);
 398                printf("%lx\t%lx\t%s\n",
 399                                index, count, page_flag_name(flags0));
 400        }
 401
 402        flags0 = flags;
 403        cgroup0 = cgroup;
 404        mapcnt0 = mapcnt;
 405        index  = offset;
 406        voff   = voffset;
 407        count  = size;
 408}
 409
 410static void flush_page_range(void)
 411{
 412        show_page_range(0, 0, 0, 0, 0, 0);
 413}
 414
 415static void show_page(unsigned long voffset, unsigned long offset,
 416                      uint64_t flags, uint64_t cgroup, uint64_t mapcnt)
 417{
 418        if (opt_pid)
 419                printf("%lx\t", voffset);
 420        if (opt_file)
 421                printf("%lx\t", voffset);
 422        if (opt_list_cgroup)
 423                printf("@%llu\t", (unsigned long long)cgroup);
 424        if (opt_list_mapcnt)
 425                printf("%lu\t", mapcnt);
 426
 427        printf("%lx\t%s\n", offset, page_flag_name(flags));
 428}
 429
 430static void show_summary(void)
 431{
 432        size_t i;
 433
 434        printf("             flags\tpage-count       MB"
 435                "  symbolic-flags\t\t\tlong-symbolic-flags\n");
 436
 437        for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 438                if (nr_pages[i])
 439                        printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 440                                (unsigned long long)page_flags[i],
 441                                nr_pages[i],
 442                                pages2mb(nr_pages[i]),
 443                                page_flag_name(page_flags[i]),
 444                                page_flag_longname(page_flags[i]));
 445        }
 446
 447        printf("             total\t%10lu %8lu\n",
 448                        total_pages, pages2mb(total_pages));
 449}
 450
 451
 452/*
 453 * page flag filters
 454 */
 455
 456static int bit_mask_ok(uint64_t flags)
 457{
 458        int i;
 459
 460        for (i = 0; i < nr_bit_filters; i++) {
 461                if (opt_bits[i] == KPF_ALL_BITS) {
 462                        if ((flags & opt_mask[i]) == 0)
 463                                return 0;
 464                } else {
 465                        if ((flags & opt_mask[i]) != opt_bits[i])
 466                                return 0;
 467                }
 468        }
 469
 470        return 1;
 471}
 472
 473static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
 474{
 475        /* SLOB/SLUB overload several page flags */
 476        if (flags & BIT(SLAB)) {
 477                if (flags & BIT(PRIVATE))
 478                        flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 479                if (flags & BIT(ACTIVE))
 480                        flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 481                if (flags & BIT(ERROR))
 482                        flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 483        }
 484
 485        /* PG_reclaim is overloaded as PG_readahead in the read path */
 486        if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 487                flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 488
 489        if (pme & PM_SOFT_DIRTY)
 490                flags |= BIT(SOFTDIRTY);
 491        if (pme & PM_FILE)
 492                flags |= BIT(FILE);
 493        if (pme & PM_SWAP)
 494                flags |= BIT(SWAP);
 495        if (pme & PM_MMAP_EXCLUSIVE)
 496                flags |= BIT(MMAP_EXCLUSIVE);
 497
 498        return flags;
 499}
 500
 501static uint64_t well_known_flags(uint64_t flags)
 502{
 503        /* hide flags intended only for kernel hacker */
 504        flags &= ~KPF_HACKERS_BITS;
 505
 506        /* hide non-hugeTLB compound pages */
 507        if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 508                flags &= ~BITS_COMPOUND;
 509
 510        return flags;
 511}
 512
 513static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 514{
 515        if (opt_raw)
 516                flags = expand_overloaded_flags(flags, pme);
 517        else
 518                flags = well_known_flags(flags);
 519
 520        return flags;
 521}
 522
 523/*
 524 * page actions
 525 */
 526
 527static void prepare_hwpoison_fd(void)
 528{
 529        char buf[MAX_PATH + 1];
 530
 531        hwpoison_debug_fs = debugfs__mount();
 532        if (!hwpoison_debug_fs) {
 533                perror("mount debugfs");
 534                exit(EXIT_FAILURE);
 535        }
 536
 537        if (opt_hwpoison && !hwpoison_inject_fd) {
 538                snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 539                        hwpoison_debug_fs);
 540                hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 541        }
 542
 543        if (opt_unpoison && !hwpoison_forget_fd) {
 544                snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 545                        hwpoison_debug_fs);
 546                hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 547        }
 548}
 549
 550static int hwpoison_page(unsigned long offset)
 551{
 552        char buf[100];
 553        int len;
 554
 555        len = sprintf(buf, "0x%lx\n", offset);
 556        len = write(hwpoison_inject_fd, buf, len);
 557        if (len < 0) {
 558                perror("hwpoison inject");
 559                return len;
 560        }
 561        return 0;
 562}
 563
 564static int unpoison_page(unsigned long offset)
 565{
 566        char buf[100];
 567        int len;
 568
 569        len = sprintf(buf, "0x%lx\n", offset);
 570        len = write(hwpoison_forget_fd, buf, len);
 571        if (len < 0) {
 572                perror("hwpoison forget");
 573                return len;
 574        }
 575        return 0;
 576}
 577
 578static int mark_page_idle(unsigned long offset)
 579{
 580        static unsigned long off;
 581        static uint64_t buf;
 582        int len;
 583
 584        if ((offset / 64 == off / 64) || buf == 0) {
 585                buf |= 1UL << (offset % 64);
 586                off = offset;
 587                return 0;
 588        }
 589
 590        len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
 591        if (len < 0) {
 592                perror("mark page idle");
 593                return len;
 594        }
 595
 596        buf = 1UL << (offset % 64);
 597        off = offset;
 598
 599        return 0;
 600}
 601
 602/*
 603 * page frame walker
 604 */
 605
 606static size_t hash_slot(uint64_t flags)
 607{
 608        size_t k = HASH_KEY(flags);
 609        size_t i;
 610
 611        /* Explicitly reserve slot 0 for flags 0: the following logic
 612         * cannot distinguish an unoccupied slot from slot (flags==0).
 613         */
 614        if (flags == 0)
 615                return 0;
 616
 617        /* search through the remaining (HASH_SIZE-1) slots */
 618        for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 619                if (!k || k >= ARRAY_SIZE(page_flags))
 620                        k = 1;
 621                if (page_flags[k] == 0) {
 622                        page_flags[k] = flags;
 623                        return k;
 624                }
 625                if (page_flags[k] == flags)
 626                        return k;
 627        }
 628
 629        fatal("hash table full: bump up HASH_SHIFT?\n");
 630        exit(EXIT_FAILURE);
 631}
 632
 633static void add_page(unsigned long voffset, unsigned long offset,
 634                     uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
 635                     uint64_t pme)
 636{
 637        flags = kpageflags_flags(flags, pme);
 638
 639        if (!bit_mask_ok(flags))
 640                return;
 641
 642        if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
 643                return;
 644
 645        if (opt_hwpoison)
 646                hwpoison_page(offset);
 647        if (opt_unpoison)
 648                unpoison_page(offset);
 649
 650        if (opt_mark_idle)
 651                mark_page_idle(offset);
 652
 653        if (opt_list == 1)
 654                show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
 655        else if (opt_list == 2)
 656                show_page(voffset, offset, flags, cgroup, mapcnt);
 657
 658        nr_pages[hash_slot(flags)]++;
 659        total_pages++;
 660}
 661
 662#define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 663static void walk_pfn(unsigned long voffset,
 664                     unsigned long index,
 665                     unsigned long count,
 666                     uint64_t pme)
 667{
 668        uint64_t buf[KPAGEFLAGS_BATCH];
 669        uint64_t cgi[KPAGEFLAGS_BATCH];
 670        uint64_t cnt[KPAGEFLAGS_BATCH];
 671        unsigned long batch;
 672        unsigned long pages;
 673        unsigned long i;
 674
 675        /*
 676         * kpagecgroup_read() reads only if kpagecgroup were opened, but
 677         * /proc/kpagecgroup might even not exist, so it's better to fill
 678         * them with zeros here.
 679         */
 680        if (count == 1)
 681                cgi[0] = 0;
 682        else
 683                memset(cgi, 0, sizeof cgi);
 684
 685        while (count) {
 686                batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 687                pages = kpageflags_read(buf, index, batch);
 688                if (pages == 0)
 689                        break;
 690
 691                if (kpagecgroup_read(cgi, index, pages) != pages)
 692                        fatal("kpagecgroup returned fewer pages than expected");
 693
 694                if (kpagecount_read(cnt, index, pages) != pages)
 695                        fatal("kpagecount returned fewer pages than expected");
 696
 697                for (i = 0; i < pages; i++)
 698                        add_page(voffset + i, index + i,
 699                                 buf[i], cgi[i], cnt[i], pme);
 700
 701                index += pages;
 702                count -= pages;
 703        }
 704}
 705
 706static void walk_swap(unsigned long voffset, uint64_t pme)
 707{
 708        uint64_t flags = kpageflags_flags(0, pme);
 709
 710        if (!bit_mask_ok(flags))
 711                return;
 712
 713        if (opt_cgroup)
 714                return;
 715
 716        if (opt_list == 1)
 717                show_page_range(voffset, pagemap_swap_offset(pme),
 718                                1, flags, 0, 0);
 719        else if (opt_list == 2)
 720                show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
 721
 722        nr_pages[hash_slot(flags)]++;
 723        total_pages++;
 724}
 725
 726#define PAGEMAP_BATCH   (64 << 10)
 727static void walk_vma(unsigned long index, unsigned long count)
 728{
 729        uint64_t buf[PAGEMAP_BATCH];
 730        unsigned long batch;
 731        unsigned long pages;
 732        unsigned long pfn;
 733        unsigned long i;
 734
 735        while (count) {
 736                batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 737                pages = pagemap_read(buf, index, batch);
 738                if (pages == 0)
 739                        break;
 740
 741                for (i = 0; i < pages; i++) {
 742                        pfn = pagemap_pfn(buf[i]);
 743                        if (pfn)
 744                                walk_pfn(index + i, pfn, 1, buf[i]);
 745                        if (buf[i] & PM_SWAP)
 746                                walk_swap(index + i, buf[i]);
 747                }
 748
 749                index += pages;
 750                count -= pages;
 751        }
 752}
 753
 754static void walk_task(unsigned long index, unsigned long count)
 755{
 756        const unsigned long end = index + count;
 757        unsigned long start;
 758        int i = 0;
 759
 760        while (index < end) {
 761
 762                while (pg_end[i] <= index)
 763                        if (++i >= nr_vmas)
 764                                return;
 765                if (pg_start[i] >= end)
 766                        return;
 767
 768                start = max_t(unsigned long, pg_start[i], index);
 769                index = min_t(unsigned long, pg_end[i], end);
 770
 771                assert(start < index);
 772                walk_vma(start, index - start);
 773        }
 774}
 775
 776static void add_addr_range(unsigned long offset, unsigned long size)
 777{
 778        if (nr_addr_ranges >= MAX_ADDR_RANGES)
 779                fatal("too many addr ranges\n");
 780
 781        opt_offset[nr_addr_ranges] = offset;
 782        opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 783        nr_addr_ranges++;
 784}
 785
 786static void walk_addr_ranges(void)
 787{
 788        int i;
 789
 790        kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
 791
 792        if (!nr_addr_ranges)
 793                add_addr_range(0, ULONG_MAX);
 794
 795        for (i = 0; i < nr_addr_ranges; i++)
 796                if (!opt_pid)
 797                        walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 798                else
 799                        walk_task(opt_offset[i], opt_size[i]);
 800
 801        if (opt_mark_idle)
 802                mark_page_idle(0);
 803
 804        close(kpageflags_fd);
 805}
 806
 807
 808/*
 809 * user interface
 810 */
 811
 812static const char *page_flag_type(uint64_t flag)
 813{
 814        if (flag & KPF_HACKERS_BITS)
 815                return "(r)";
 816        if (flag & KPF_OVERLOADED_BITS)
 817                return "(o)";
 818        return "   ";
 819}
 820
 821static void usage(void)
 822{
 823        size_t i, j;
 824
 825        printf(
 826"page-types [options]\n"
 827"            -r|--raw                   Raw mode, for kernel developers\n"
 828"            -d|--describe flags        Describe flags\n"
 829"            -a|--addr    addr-spec     Walk a range of pages\n"
 830"            -b|--bits    bits-spec     Walk pages with specified bits\n"
 831"            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
 832"            -p|--pid     pid           Walk process address space\n"
 833"            -f|--file    filename      Walk file address space\n"
 834"            -i|--mark-idle             Mark pages idle\n"
 835"            -l|--list                  Show page details in ranges\n"
 836"            -L|--list-each             Show page details one by one\n"
 837"            -C|--list-cgroup           Show cgroup inode for pages\n"
 838"            -M|--list-mapcnt           Show page map count\n"
 839"            -N|--no-summary            Don't show summary info\n"
 840"            -X|--hwpoison              hwpoison pages\n"
 841"            -x|--unpoison              unpoison pages\n"
 842"            -F|--kpageflags filename   kpageflags file to parse\n"
 843"            -h|--help                  Show this usage message\n"
 844"flags:\n"
 845"            0x10                       bitfield format, e.g.\n"
 846"            anon                       bit-name, e.g.\n"
 847"            0x10,anon                  comma-separated list, e.g.\n"
 848"addr-spec:\n"
 849"            N                          one page at offset N (unit: pages)\n"
 850"            N+M                        pages range from N to N+M-1\n"
 851"            N,M                        pages range from N to M-1\n"
 852"            N,                         pages range from N to end\n"
 853"            ,M                         pages range from 0 to M-1\n"
 854"bits-spec:\n"
 855"            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 856"            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 857"            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 858"            =bit1,bit2                 flags == (bit1|bit2)\n"
 859"bit-names:\n"
 860        );
 861
 862        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 863                if (!page_flag_names[i])
 864                        continue;
 865                printf("%16s%s", page_flag_names[i] + 2,
 866                                 page_flag_type(1ULL << i));
 867                if (++j > 3) {
 868                        j = 0;
 869                        putchar('\n');
 870                }
 871        }
 872        printf("\n                                   "
 873                "(r) raw mode bits  (o) overloaded bits\n");
 874}
 875
 876static unsigned long long parse_number(const char *str)
 877{
 878        unsigned long long n;
 879
 880        n = strtoll(str, NULL, 0);
 881
 882        if (n == 0 && str[0] != '0')
 883                fatal("invalid name or number: %s\n", str);
 884
 885        return n;
 886}
 887
 888static void parse_pid(const char *str)
 889{
 890        FILE *file;
 891        char buf[5000];
 892
 893        opt_pid = parse_number(str);
 894
 895        sprintf(buf, "/proc/%d/pagemap", opt_pid);
 896        pagemap_fd = checked_open(buf, O_RDONLY);
 897
 898        sprintf(buf, "/proc/%d/maps", opt_pid);
 899        file = fopen(buf, "r");
 900        if (!file) {
 901                perror(buf);
 902                exit(EXIT_FAILURE);
 903        }
 904
 905        while (fgets(buf, sizeof(buf), file) != NULL) {
 906                unsigned long vm_start;
 907                unsigned long vm_end;
 908                unsigned long long pgoff;
 909                int major, minor;
 910                char r, w, x, s;
 911                unsigned long ino;
 912                int n;
 913
 914                n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 915                           &vm_start,
 916                           &vm_end,
 917                           &r, &w, &x, &s,
 918                           &pgoff,
 919                           &major, &minor,
 920                           &ino);
 921                if (n < 10) {
 922                        fprintf(stderr, "unexpected line: %s\n", buf);
 923                        continue;
 924                }
 925                pg_start[nr_vmas] = vm_start / page_size;
 926                pg_end[nr_vmas] = vm_end / page_size;
 927                if (++nr_vmas >= MAX_VMAS) {
 928                        fprintf(stderr, "too many VMAs\n");
 929                        break;
 930                }
 931        }
 932        fclose(file);
 933}
 934
 935static void show_file(const char *name, const struct stat *st)
 936{
 937        unsigned long long size = st->st_size;
 938        char atime[64], mtime[64];
 939        long now = time(NULL);
 940
 941        printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 942                        name, (unsigned)st->st_ino,
 943                        size, (size + page_size - 1) / page_size);
 944
 945        strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 946        strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 947
 948        printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 949                        mtime, now - st->st_mtime,
 950                        atime, now - st->st_atime);
 951}
 952
 953static sigjmp_buf sigbus_jmp;
 954
 955static void * volatile sigbus_addr;
 956
 957static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 958{
 959        (void)sig;
 960        (void)ucontex;
 961        sigbus_addr = info ? info->si_addr : NULL;
 962        siglongjmp(sigbus_jmp, 1);
 963}
 964
 965static struct sigaction sigbus_action = {
 966        .sa_sigaction = sigbus_handler,
 967        .sa_flags = SA_SIGINFO,
 968};
 969
 970static void walk_file_range(const char *name, int fd,
 971                            unsigned long off, unsigned long end)
 972{
 973        uint8_t vec[PAGEMAP_BATCH];
 974        uint64_t buf[PAGEMAP_BATCH], flags;
 975        uint64_t cgroup = 0;
 976        uint64_t mapcnt = 0;
 977        unsigned long nr_pages, pfn, i;
 978        ssize_t len;
 979        void *ptr;
 980        int first = 1;
 981
 982        for (; off < end; off += len) {
 983                nr_pages = (end - off + page_size - 1) / page_size;
 984                if (nr_pages > PAGEMAP_BATCH)
 985                        nr_pages = PAGEMAP_BATCH;
 986                len = nr_pages * page_size;
 987
 988                ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 989                if (ptr == MAP_FAILED)
 990                        fatal("mmap failed: %s", name);
 991
 992                /* determine cached pages */
 993                if (mincore(ptr, len, vec))
 994                        fatal("mincore failed: %s", name);
 995
 996                /* turn off readahead */
 997                if (madvise(ptr, len, MADV_RANDOM))
 998                        fatal("madvice failed: %s", name);
 999
1000                if (sigsetjmp(sigbus_jmp, 1)) {
1001                        end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1002                        fprintf(stderr, "got sigbus at offset %lld: %s\n",
1003                                        (long long)end, name);
1004                        goto got_sigbus;
1005                }
1006
1007                /* populate ptes */
1008                for (i = 0; i < nr_pages ; i++) {
1009                        if (vec[i] & 1)
1010                                (void)*(volatile int *)(ptr + i * page_size);
1011                }
1012got_sigbus:
1013
1014                /* turn off harvesting reference bits */
1015                if (madvise(ptr, len, MADV_SEQUENTIAL))
1016                        fatal("madvice failed: %s", name);
1017
1018                if (pagemap_read(buf, (unsigned long)ptr / page_size,
1019                                        nr_pages) != nr_pages)
1020                        fatal("cannot read pagemap");
1021
1022                munmap(ptr, len);
1023
1024                for (i = 0; i < nr_pages; i++) {
1025                        pfn = pagemap_pfn(buf[i]);
1026                        if (!pfn)
1027                                continue;
1028                        if (!kpageflags_read(&flags, pfn, 1))
1029                                continue;
1030                        if (!kpagecgroup_read(&cgroup, pfn, 1))
1031                                fatal("kpagecgroup_read failed");
1032                        if (!kpagecount_read(&mapcnt, pfn, 1))
1033                                fatal("kpagecount_read failed");
1034                        if (first && opt_list) {
1035                                first = 0;
1036                                flush_page_range();
1037                        }
1038                        add_page(off / page_size + i, pfn,
1039                                 flags, cgroup, mapcnt, buf[i]);
1040                }
1041        }
1042}
1043
1044static void walk_file(const char *name, const struct stat *st)
1045{
1046        int i;
1047        int fd;
1048
1049        fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
1050
1051        if (!nr_addr_ranges)
1052                add_addr_range(0, st->st_size / page_size);
1053
1054        for (i = 0; i < nr_addr_ranges; i++)
1055                walk_file_range(name, fd, opt_offset[i] * page_size,
1056                                (opt_offset[i] + opt_size[i]) * page_size);
1057
1058        close(fd);
1059}
1060
1061int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1062{
1063        (void)f;
1064        switch (type) {
1065        case FTW_F:
1066                if (S_ISREG(st->st_mode))
1067                        walk_file(name, st);
1068                break;
1069        case FTW_DNR:
1070                fprintf(stderr, "cannot read dir: %s\n", name);
1071                break;
1072        }
1073        return 0;
1074}
1075
1076struct stat st;
1077
1078static void walk_page_cache(void)
1079{
1080        kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1081        pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1082        sigaction(SIGBUS, &sigbus_action, NULL);
1083
1084        if (stat(opt_file, &st))
1085                fatal("stat failed: %s\n", opt_file);
1086
1087        if (S_ISREG(st.st_mode)) {
1088                walk_file(opt_file, &st);
1089        } else if (S_ISDIR(st.st_mode)) {
1090                /* do not follow symlinks and mountpoints */
1091                if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1092                        fatal("nftw failed: %s\n", opt_file);
1093        } else
1094                fatal("unhandled file type: %s\n", opt_file);
1095
1096        close(kpageflags_fd);
1097        close(pagemap_fd);
1098        signal(SIGBUS, SIG_DFL);
1099}
1100
1101static void parse_file(const char *name)
1102{
1103        opt_file = name;
1104}
1105
1106static void parse_cgroup(const char *path)
1107{
1108        if (path[0] == '@') {
1109                opt_cgroup = parse_number(path + 1);
1110                return;
1111        }
1112
1113        struct stat st;
1114
1115        if (stat(path, &st))
1116                fatal("stat failed: %s: %m\n", path);
1117
1118        if (!S_ISDIR(st.st_mode))
1119                fatal("cgroup supposed to be a directory: %s\n", path);
1120
1121        opt_cgroup = st.st_ino;
1122}
1123
1124static void parse_addr_range(const char *optarg)
1125{
1126        unsigned long offset;
1127        unsigned long size;
1128        char *p;
1129
1130        p = strchr(optarg, ',');
1131        if (!p)
1132                p = strchr(optarg, '+');
1133
1134        if (p == optarg) {
1135                offset = 0;
1136                size   = parse_number(p + 1);
1137        } else if (p) {
1138                offset = parse_number(optarg);
1139                if (p[1] == '\0')
1140                        size = ULONG_MAX;
1141                else {
1142                        size = parse_number(p + 1);
1143                        if (*p == ',') {
1144                                if (size < offset)
1145                                        fatal("invalid range: %lu,%lu\n",
1146                                                        offset, size);
1147                                size -= offset;
1148                        }
1149                }
1150        } else {
1151                offset = parse_number(optarg);
1152                size   = 1;
1153        }
1154
1155        add_addr_range(offset, size);
1156}
1157
1158static void add_bits_filter(uint64_t mask, uint64_t bits)
1159{
1160        if (nr_bit_filters >= MAX_BIT_FILTERS)
1161                fatal("too much bit filters\n");
1162
1163        opt_mask[nr_bit_filters] = mask;
1164        opt_bits[nr_bit_filters] = bits;
1165        nr_bit_filters++;
1166}
1167
1168static uint64_t parse_flag_name(const char *str, int len)
1169{
1170        size_t i;
1171
1172        if (!*str || !len)
1173                return 0;
1174
1175        if (len <= 8 && !strncmp(str, "compound", len))
1176                return BITS_COMPOUND;
1177
1178        for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1179                if (!page_flag_names[i])
1180                        continue;
1181                if (!strncmp(str, page_flag_names[i] + 2, len))
1182                        return 1ULL << i;
1183        }
1184
1185        return parse_number(str);
1186}
1187
1188static uint64_t parse_flag_names(const char *str, int all)
1189{
1190        const char *p    = str;
1191        uint64_t   flags = 0;
1192
1193        while (1) {
1194                if (*p == ',' || *p == '=' || *p == '\0') {
1195                        if ((*str != '~') || (*str == '~' && all && *++str))
1196                                flags |= parse_flag_name(str, p - str);
1197                        if (*p != ',')
1198                                break;
1199                        str = p + 1;
1200                }
1201                p++;
1202        }
1203
1204        return flags;
1205}
1206
1207static void parse_bits_mask(const char *optarg)
1208{
1209        uint64_t mask;
1210        uint64_t bits;
1211        const char *p;
1212
1213        p = strchr(optarg, '=');
1214        if (p == optarg) {
1215                mask = KPF_ALL_BITS;
1216                bits = parse_flag_names(p + 1, 0);
1217        } else if (p) {
1218                mask = parse_flag_names(optarg, 0);
1219                bits = parse_flag_names(p + 1, 0);
1220        } else if (strchr(optarg, '~')) {
1221                mask = parse_flag_names(optarg, 1);
1222                bits = parse_flag_names(optarg, 0);
1223        } else {
1224                mask = parse_flag_names(optarg, 0);
1225                bits = KPF_ALL_BITS;
1226        }
1227
1228        add_bits_filter(mask, bits);
1229}
1230
1231static void parse_kpageflags(const char *name)
1232{
1233        opt_kpageflags = name;
1234}
1235
1236static void describe_flags(const char *optarg)
1237{
1238        uint64_t flags = parse_flag_names(optarg, 0);
1239
1240        printf("0x%016llx\t%s\t%s\n",
1241                (unsigned long long)flags,
1242                page_flag_name(flags),
1243                page_flag_longname(flags));
1244}
1245
1246static const struct option opts[] = {
1247        { "raw"       , 0, NULL, 'r' },
1248        { "pid"       , 1, NULL, 'p' },
1249        { "file"      , 1, NULL, 'f' },
1250        { "addr"      , 1, NULL, 'a' },
1251        { "bits"      , 1, NULL, 'b' },
1252        { "cgroup"    , 1, NULL, 'c' },
1253        { "describe"  , 1, NULL, 'd' },
1254        { "mark-idle" , 0, NULL, 'i' },
1255        { "list"      , 0, NULL, 'l' },
1256        { "list-each" , 0, NULL, 'L' },
1257        { "list-cgroup", 0, NULL, 'C' },
1258        { "list-mapcnt", 0, NULL, 'M' },
1259        { "no-summary", 0, NULL, 'N' },
1260        { "hwpoison"  , 0, NULL, 'X' },
1261        { "unpoison"  , 0, NULL, 'x' },
1262        { "kpageflags", 0, NULL, 'F' },
1263        { "help"      , 0, NULL, 'h' },
1264        { NULL        , 0, NULL, 0 }
1265};
1266
1267int main(int argc, char *argv[])
1268{
1269        int c;
1270
1271        page_size = getpagesize();
1272
1273        while ((c = getopt_long(argc, argv,
1274                                "rp:f:a:b:d:c:CilLMNXxF:h",
1275                                opts, NULL)) != -1) {
1276                switch (c) {
1277                case 'r':
1278                        opt_raw = 1;
1279                        break;
1280                case 'p':
1281                        parse_pid(optarg);
1282                        break;
1283                case 'f':
1284                        parse_file(optarg);
1285                        break;
1286                case 'a':
1287                        parse_addr_range(optarg);
1288                        break;
1289                case 'b':
1290                        parse_bits_mask(optarg);
1291                        break;
1292                case 'c':
1293                        parse_cgroup(optarg);
1294                        break;
1295                case 'C':
1296                        opt_list_cgroup = 1;
1297                        break;
1298                case 'd':
1299                        describe_flags(optarg);
1300                        exit(0);
1301                case 'i':
1302                        opt_mark_idle = 1;
1303                        break;
1304                case 'l':
1305                        opt_list = 1;
1306                        break;
1307                case 'L':
1308                        opt_list = 2;
1309                        break;
1310                case 'M':
1311                        opt_list_mapcnt = 1;
1312                        break;
1313                case 'N':
1314                        opt_no_summary = 1;
1315                        break;
1316                case 'X':
1317                        opt_hwpoison = 1;
1318                        prepare_hwpoison_fd();
1319                        break;
1320                case 'x':
1321                        opt_unpoison = 1;
1322                        prepare_hwpoison_fd();
1323                        break;
1324                case 'F':
1325                        parse_kpageflags(optarg);
1326                        break;
1327                case 'h':
1328                        usage();
1329                        exit(0);
1330                default:
1331                        usage();
1332                        exit(1);
1333                }
1334        }
1335
1336        if (!opt_kpageflags)
1337                opt_kpageflags = PROC_KPAGEFLAGS;
1338
1339        if (opt_cgroup || opt_list_cgroup)
1340                kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1341
1342        if (opt_list && opt_list_mapcnt)
1343                kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1344
1345        if (opt_mark_idle)
1346                page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1347
1348        if (opt_list && opt_pid)
1349                printf("voffset\t");
1350        if (opt_list && opt_file)
1351                printf("foffset\t");
1352        if (opt_list && opt_list_cgroup)
1353                printf("cgroup\t");
1354        if (opt_list && opt_list_mapcnt)
1355                printf("map-cnt\t");
1356
1357        if (opt_list == 1)
1358                printf("offset\tlen\tflags\n");
1359        if (opt_list == 2)
1360                printf("offset\tflags\n");
1361
1362        if (opt_file)
1363                walk_page_cache();
1364        else
1365                walk_addr_ranges();
1366
1367        if (opt_list == 1)
1368                flush_page_range();
1369
1370        if (opt_no_summary)
1371                return 0;
1372
1373        if (opt_list)
1374                printf("\n\n");
1375
1376        if (opt_file) {
1377                show_file(opt_file, &st);
1378                printf("\n");
1379        }
1380
1381        show_summary();
1382
1383        if (opt_list_mapcnt)
1384                close(kpagecount_fd);
1385
1386        if (page_idle_fd >= 0)
1387                close(page_idle_fd);
1388
1389        return 0;
1390}
1391