linux/tools/vm/page-types.c
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   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
 108static 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
 158static const char * const debugfs_known_mountpoints[] = {
 159        "/sys/kernel/debug",
 160        "/debug",
 161        0,
 162};
 163
 164/*
 165 * data structures
 166 */
 167
 168static int              opt_raw;        /* for kernel developers */
 169static int              opt_list;       /* list pages (in ranges) */
 170static int              opt_no_summary; /* don't show summary */
 171static pid_t            opt_pid;        /* process to walk */
 172const char *            opt_file;       /* file or directory path */
 173static uint64_t         opt_cgroup;     /* cgroup inode */
 174static int              opt_list_cgroup;/* list page cgroup */
 175
 176#define MAX_ADDR_RANGES 1024
 177static int              nr_addr_ranges;
 178static unsigned long    opt_offset[MAX_ADDR_RANGES];
 179static unsigned long    opt_size[MAX_ADDR_RANGES];
 180
 181#define MAX_VMAS        10240
 182static int              nr_vmas;
 183static unsigned long    pg_start[MAX_VMAS];
 184static unsigned long    pg_end[MAX_VMAS];
 185
 186#define MAX_BIT_FILTERS 64
 187static int              nr_bit_filters;
 188static uint64_t         opt_mask[MAX_BIT_FILTERS];
 189static uint64_t         opt_bits[MAX_BIT_FILTERS];
 190
 191static int              page_size;
 192
 193static int              pagemap_fd;
 194static int              kpageflags_fd;
 195static int              kpagecgroup_fd = -1;
 196
 197static int              opt_hwpoison;
 198static int              opt_unpoison;
 199
 200static const char       *hwpoison_debug_fs;
 201static int              hwpoison_inject_fd;
 202static 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
 209static unsigned long    total_pages;
 210static unsigned long    nr_pages[HASH_SIZE];
 211static 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
 230static unsigned long pages2mb(unsigned long pages)
 231{
 232        return (pages * page_size) >> 20;
 233}
 234
 235static 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
 245static 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
 261static 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
 282static 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
 289static 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
 299static 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
 306static 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
 318static 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
 327static 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
 346static 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
 370static 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
 403static void flush_page_range(void)
 404{
 405        show_page_range(0, 0, 0, 0, 0);
 406}
 407
 408static 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
 420static 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
 446static 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
 463static 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
 491static 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
 503static 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
 517static 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
 540static 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
 554static 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
 572static 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
 599static 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 */
 625static 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
 663static 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)
 683static 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
 710static 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
 732static 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
 742static 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
 765static 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
 774static 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
 826static 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
 838static 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
 885static 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
 903static sigjmp_buf sigbus_jmp;
 904
 905static void * volatile sigbus_addr;
 906
 907static 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
 915static struct sigaction sigbus_action = {
 916        .sa_sigaction = sigbus_handler,
 917        .sa_flags = SA_SIGINFO,
 918};
 919
 920static 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                }
 964got_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
 997int 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
1012static 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
1037static void parse_file(const char *name)
1038{
1039        opt_file = name;
1040}
1041
1042static 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
1060static 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
1094static 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
1104static 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
1124static 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
1143static 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
1167static 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
1177static 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
1195int 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}
1286