linux/Documentation/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 _LARGEFILE64_SOURCE
  23#include <stdio.h>
  24#include <stdlib.h>
  25#include <unistd.h>
  26#include <stdint.h>
  27#include <stdarg.h>
  28#include <string.h>
  29#include <getopt.h>
  30#include <limits.h>
  31#include <assert.h>
  32#include <sys/types.h>
  33#include <sys/errno.h>
  34#include <sys/fcntl.h>
  35#include <sys/mount.h>
  36#include <sys/statfs.h>
  37#include "../../include/linux/magic.h"
  38
  39
  40#ifndef MAX_PATH
  41# define MAX_PATH 256
  42#endif
  43
  44#ifndef STR
  45# define _STR(x) #x
  46# define STR(x) _STR(x)
  47#endif
  48
  49/*
  50 * pagemap kernel ABI bits
  51 */
  52
  53#define PM_ENTRY_BYTES      sizeof(uint64_t)
  54#define PM_STATUS_BITS      3
  55#define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
  56#define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
  57#define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
  58#define PM_PSHIFT_BITS      6
  59#define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
  60#define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
  61#define PM_PSHIFT(x)        (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
  62#define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
  63#define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
  64
  65#define PM_PRESENT          PM_STATUS(4LL)
  66#define PM_SWAP             PM_STATUS(2LL)
  67
  68
  69/*
  70 * kernel page flags
  71 */
  72
  73#define KPF_BYTES               8
  74#define PROC_KPAGEFLAGS         "/proc/kpageflags"
  75
  76/* copied from kpageflags_read() */
  77#define KPF_LOCKED              0
  78#define KPF_ERROR               1
  79#define KPF_REFERENCED          2
  80#define KPF_UPTODATE            3
  81#define KPF_DIRTY               4
  82#define KPF_LRU                 5
  83#define KPF_ACTIVE              6
  84#define KPF_SLAB                7
  85#define KPF_WRITEBACK           8
  86#define KPF_RECLAIM             9
  87#define KPF_BUDDY               10
  88
  89/* [11-20] new additions in 2.6.31 */
  90#define KPF_MMAP                11
  91#define KPF_ANON                12
  92#define KPF_SWAPCACHE           13
  93#define KPF_SWAPBACKED          14
  94#define KPF_COMPOUND_HEAD       15
  95#define KPF_COMPOUND_TAIL       16
  96#define KPF_HUGE                17
  97#define KPF_UNEVICTABLE         18
  98#define KPF_HWPOISON            19
  99#define KPF_NOPAGE              20
 100#define KPF_KSM                 21
 101
 102/* [32-] kernel hacking assistances */
 103#define KPF_RESERVED            32
 104#define KPF_MLOCKED             33
 105#define KPF_MAPPEDTODISK        34
 106#define KPF_PRIVATE             35
 107#define KPF_PRIVATE_2           36
 108#define KPF_OWNER_PRIVATE       37
 109#define KPF_ARCH                38
 110#define KPF_UNCACHED            39
 111
 112/* [48-] take some arbitrary free slots for expanding overloaded flags
 113 * not part of kernel API
 114 */
 115#define KPF_READAHEAD           48
 116#define KPF_SLOB_FREE           49
 117#define KPF_SLUB_FROZEN         50
 118#define KPF_SLUB_DEBUG          51
 119
 120#define KPF_ALL_BITS            ((uint64_t)~0ULL)
 121#define KPF_HACKERS_BITS        (0xffffULL << 32)
 122#define KPF_OVERLOADED_BITS     (0xffffULL << 48)
 123#define BIT(name)               (1ULL << KPF_##name)
 124#define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
 125
 126static const char *page_flag_names[] = {
 127        [KPF_LOCKED]            = "L:locked",
 128        [KPF_ERROR]             = "E:error",
 129        [KPF_REFERENCED]        = "R:referenced",
 130        [KPF_UPTODATE]          = "U:uptodate",
 131        [KPF_DIRTY]             = "D:dirty",
 132        [KPF_LRU]               = "l:lru",
 133        [KPF_ACTIVE]            = "A:active",
 134        [KPF_SLAB]              = "S:slab",
 135        [KPF_WRITEBACK]         = "W:writeback",
 136        [KPF_RECLAIM]           = "I:reclaim",
 137        [KPF_BUDDY]             = "B:buddy",
 138
 139        [KPF_MMAP]              = "M:mmap",
 140        [KPF_ANON]              = "a:anonymous",
 141        [KPF_SWAPCACHE]         = "s:swapcache",
 142        [KPF_SWAPBACKED]        = "b:swapbacked",
 143        [KPF_COMPOUND_HEAD]     = "H:compound_head",
 144        [KPF_COMPOUND_TAIL]     = "T:compound_tail",
 145        [KPF_HUGE]              = "G:huge",
 146        [KPF_UNEVICTABLE]       = "u:unevictable",
 147        [KPF_HWPOISON]          = "X:hwpoison",
 148        [KPF_NOPAGE]            = "n:nopage",
 149        [KPF_KSM]               = "x:ksm",
 150
 151        [KPF_RESERVED]          = "r:reserved",
 152        [KPF_MLOCKED]           = "m:mlocked",
 153        [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
 154        [KPF_PRIVATE]           = "P:private",
 155        [KPF_PRIVATE_2]         = "p:private_2",
 156        [KPF_OWNER_PRIVATE]     = "O:owner_private",
 157        [KPF_ARCH]              = "h:arch",
 158        [KPF_UNCACHED]          = "c:uncached",
 159
 160        [KPF_READAHEAD]         = "I:readahead",
 161        [KPF_SLOB_FREE]         = "P:slob_free",
 162        [KPF_SLUB_FROZEN]       = "A:slub_frozen",
 163        [KPF_SLUB_DEBUG]        = "E:slub_debug",
 164};
 165
 166
 167static const char *debugfs_known_mountpoints[] = {
 168        "/sys/kernel/debug",
 169        "/debug",
 170        0,
 171};
 172
 173/*
 174 * data structures
 175 */
 176
 177static int              opt_raw;        /* for kernel developers */
 178static int              opt_list;       /* list pages (in ranges) */
 179static int              opt_no_summary; /* don't show summary */
 180static pid_t            opt_pid;        /* process to walk */
 181
 182#define MAX_ADDR_RANGES 1024
 183static int              nr_addr_ranges;
 184static unsigned long    opt_offset[MAX_ADDR_RANGES];
 185static unsigned long    opt_size[MAX_ADDR_RANGES];
 186
 187#define MAX_VMAS        10240
 188static int              nr_vmas;
 189static unsigned long    pg_start[MAX_VMAS];
 190static unsigned long    pg_end[MAX_VMAS];
 191
 192#define MAX_BIT_FILTERS 64
 193static int              nr_bit_filters;
 194static uint64_t         opt_mask[MAX_BIT_FILTERS];
 195static uint64_t         opt_bits[MAX_BIT_FILTERS];
 196
 197static int              page_size;
 198
 199static int              pagemap_fd;
 200static int              kpageflags_fd;
 201
 202static int              opt_hwpoison;
 203static int              opt_unpoison;
 204
 205static char             hwpoison_debug_fs[MAX_PATH+1];
 206static int              hwpoison_inject_fd;
 207static int              hwpoison_forget_fd;
 208
 209#define HASH_SHIFT      13
 210#define HASH_SIZE       (1 << HASH_SHIFT)
 211#define HASH_MASK       (HASH_SIZE - 1)
 212#define HASH_KEY(flags) (flags & HASH_MASK)
 213
 214static unsigned long    total_pages;
 215static unsigned long    nr_pages[HASH_SIZE];
 216static uint64_t         page_flags[HASH_SIZE];
 217
 218
 219/*
 220 * helper functions
 221 */
 222
 223#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 224
 225#define min_t(type, x, y) ({                    \
 226        type __min1 = (x);                      \
 227        type __min2 = (y);                      \
 228        __min1 < __min2 ? __min1 : __min2; })
 229
 230#define max_t(type, x, y) ({                    \
 231        type __max1 = (x);                      \
 232        type __max2 = (y);                      \
 233        __max1 > __max2 ? __max1 : __max2; })
 234
 235static unsigned long pages2mb(unsigned long pages)
 236{
 237        return (pages * page_size) >> 20;
 238}
 239
 240static void fatal(const char *x, ...)
 241{
 242        va_list ap;
 243
 244        va_start(ap, x);
 245        vfprintf(stderr, x, ap);
 246        va_end(ap);
 247        exit(EXIT_FAILURE);
 248}
 249
 250static int checked_open(const char *pathname, int flags)
 251{
 252        int fd = open(pathname, flags);
 253
 254        if (fd < 0) {
 255                perror(pathname);
 256                exit(EXIT_FAILURE);
 257        }
 258
 259        return fd;
 260}
 261
 262/*
 263 * pagemap/kpageflags routines
 264 */
 265
 266static unsigned long do_u64_read(int fd, char *name,
 267                                 uint64_t *buf,
 268                                 unsigned long index,
 269                                 unsigned long count)
 270{
 271        long bytes;
 272
 273        if (index > ULONG_MAX / 8)
 274                fatal("index overflow: %lu\n", index);
 275
 276        if (lseek(fd, index * 8, SEEK_SET) < 0) {
 277                perror(name);
 278                exit(EXIT_FAILURE);
 279        }
 280
 281        bytes = read(fd, buf, count * 8);
 282        if (bytes < 0) {
 283                perror(name);
 284                exit(EXIT_FAILURE);
 285        }
 286        if (bytes % 8)
 287                fatal("partial read: %lu bytes\n", bytes);
 288
 289        return bytes / 8;
 290}
 291
 292static unsigned long kpageflags_read(uint64_t *buf,
 293                                     unsigned long index,
 294                                     unsigned long pages)
 295{
 296        return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
 297}
 298
 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
 318
 319/*
 320 * page flag names
 321 */
 322
 323static char *page_flag_name(uint64_t flags)
 324{
 325        static char buf[65];
 326        int present;
 327        int i, j;
 328
 329        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 330                present = (flags >> i) & 1;
 331                if (!page_flag_names[i]) {
 332                        if (present)
 333                                fatal("unknown flag bit %d\n", i);
 334                        continue;
 335                }
 336                buf[j++] = present ? page_flag_names[i][0] : '_';
 337        }
 338
 339        return buf;
 340}
 341
 342static char *page_flag_longname(uint64_t flags)
 343{
 344        static char buf[1024];
 345        int i, n;
 346
 347        for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 348                if (!page_flag_names[i])
 349                        continue;
 350                if ((flags >> i) & 1)
 351                        n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 352                                        page_flag_names[i] + 2);
 353        }
 354        if (n)
 355                n--;
 356        buf[n] = '\0';
 357
 358        return buf;
 359}
 360
 361
 362/*
 363 * page list and summary
 364 */
 365
 366static void show_page_range(unsigned long voffset,
 367                            unsigned long offset, uint64_t flags)
 368{
 369        static uint64_t      flags0;
 370        static unsigned long voff;
 371        static unsigned long index;
 372        static unsigned long count;
 373
 374        if (flags == flags0 && offset == index + count &&
 375            (!opt_pid || voffset == voff + count)) {
 376                count++;
 377                return;
 378        }
 379
 380        if (count) {
 381                if (opt_pid)
 382                        printf("%lx\t", voff);
 383                printf("%lx\t%lx\t%s\n",
 384                                index, count, page_flag_name(flags0));
 385        }
 386
 387        flags0 = flags;
 388        index  = offset;
 389        voff   = voffset;
 390        count  = 1;
 391}
 392
 393static void show_page(unsigned long voffset,
 394                      unsigned long offset, uint64_t flags)
 395{
 396        if (opt_pid)
 397                printf("%lx\t", voffset);
 398        printf("%lx\t%s\n", offset, page_flag_name(flags));
 399}
 400
 401static void show_summary(void)
 402{
 403        int i;
 404
 405        printf("             flags\tpage-count       MB"
 406                "  symbolic-flags\t\t\tlong-symbolic-flags\n");
 407
 408        for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 409                if (nr_pages[i])
 410                        printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 411                                (unsigned long long)page_flags[i],
 412                                nr_pages[i],
 413                                pages2mb(nr_pages[i]),
 414                                page_flag_name(page_flags[i]),
 415                                page_flag_longname(page_flags[i]));
 416        }
 417
 418        printf("             total\t%10lu %8lu\n",
 419                        total_pages, pages2mb(total_pages));
 420}
 421
 422
 423/*
 424 * page flag filters
 425 */
 426
 427static int bit_mask_ok(uint64_t flags)
 428{
 429        int i;
 430
 431        for (i = 0; i < nr_bit_filters; i++) {
 432                if (opt_bits[i] == KPF_ALL_BITS) {
 433                        if ((flags & opt_mask[i]) == 0)
 434                                return 0;
 435                } else {
 436                        if ((flags & opt_mask[i]) != opt_bits[i])
 437                                return 0;
 438                }
 439        }
 440
 441        return 1;
 442}
 443
 444static uint64_t expand_overloaded_flags(uint64_t flags)
 445{
 446        /* SLOB/SLUB overload several page flags */
 447        if (flags & BIT(SLAB)) {
 448                if (flags & BIT(PRIVATE))
 449                        flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 450                if (flags & BIT(ACTIVE))
 451                        flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 452                if (flags & BIT(ERROR))
 453                        flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 454        }
 455
 456        /* PG_reclaim is overloaded as PG_readahead in the read path */
 457        if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 458                flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 459
 460        return flags;
 461}
 462
 463static uint64_t well_known_flags(uint64_t flags)
 464{
 465        /* hide flags intended only for kernel hacker */
 466        flags &= ~KPF_HACKERS_BITS;
 467
 468        /* hide non-hugeTLB compound pages */
 469        if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 470                flags &= ~BITS_COMPOUND;
 471
 472        return flags;
 473}
 474
 475static uint64_t kpageflags_flags(uint64_t flags)
 476{
 477        flags = expand_overloaded_flags(flags);
 478
 479        if (!opt_raw)
 480                flags = well_known_flags(flags);
 481
 482        return flags;
 483}
 484
 485/* verify that a mountpoint is actually a debugfs instance */
 486static int debugfs_valid_mountpoint(const char *debugfs)
 487{
 488        struct statfs st_fs;
 489
 490        if (statfs(debugfs, &st_fs) < 0)
 491                return -ENOENT;
 492        else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
 493                return -ENOENT;
 494
 495        return 0;
 496}
 497
 498/* find the path to the mounted debugfs */
 499static const char *debugfs_find_mountpoint(void)
 500{
 501        const char **ptr;
 502        char type[100];
 503        FILE *fp;
 504
 505        ptr = debugfs_known_mountpoints;
 506        while (*ptr) {
 507                if (debugfs_valid_mountpoint(*ptr) == 0) {
 508                        strcpy(hwpoison_debug_fs, *ptr);
 509                        return hwpoison_debug_fs;
 510                }
 511                ptr++;
 512        }
 513
 514        /* give up and parse /proc/mounts */
 515        fp = fopen("/proc/mounts", "r");
 516        if (fp == NULL)
 517                perror("Can't open /proc/mounts for read");
 518
 519        while (fscanf(fp, "%*s %"
 520                      STR(MAX_PATH)
 521                      "s %99s %*s %*d %*d\n",
 522                      hwpoison_debug_fs, type) == 2) {
 523                if (strcmp(type, "debugfs") == 0)
 524                        break;
 525        }
 526        fclose(fp);
 527
 528        if (strcmp(type, "debugfs") != 0)
 529                return NULL;
 530
 531        return hwpoison_debug_fs;
 532}
 533
 534/* mount the debugfs somewhere if it's not mounted */
 535
 536static void debugfs_mount(void)
 537{
 538        const char **ptr;
 539
 540        /* see if it's already mounted */
 541        if (debugfs_find_mountpoint())
 542                return;
 543
 544        ptr = debugfs_known_mountpoints;
 545        while (*ptr) {
 546                if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
 547                        /* save the mountpoint */
 548                        strcpy(hwpoison_debug_fs, *ptr);
 549                        break;
 550                }
 551                ptr++;
 552        }
 553
 554        if (*ptr == NULL) {
 555                perror("mount debugfs");
 556                exit(EXIT_FAILURE);
 557        }
 558}
 559
 560/*
 561 * page actions
 562 */
 563
 564static void prepare_hwpoison_fd(void)
 565{
 566        char buf[MAX_PATH + 1];
 567
 568        debugfs_mount();
 569
 570        if (opt_hwpoison && !hwpoison_inject_fd) {
 571                snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 572                        hwpoison_debug_fs);
 573                hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 574        }
 575
 576        if (opt_unpoison && !hwpoison_forget_fd) {
 577                snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 578                        hwpoison_debug_fs);
 579                hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 580        }
 581}
 582
 583static int hwpoison_page(unsigned long offset)
 584{
 585        char buf[100];
 586        int len;
 587
 588        len = sprintf(buf, "0x%lx\n", offset);
 589        len = write(hwpoison_inject_fd, buf, len);
 590        if (len < 0) {
 591                perror("hwpoison inject");
 592                return len;
 593        }
 594        return 0;
 595}
 596
 597static int unpoison_page(unsigned long offset)
 598{
 599        char buf[100];
 600        int len;
 601
 602        len = sprintf(buf, "0x%lx\n", offset);
 603        len = write(hwpoison_forget_fd, buf, len);
 604        if (len < 0) {
 605                perror("hwpoison forget");
 606                return len;
 607        }
 608        return 0;
 609}
 610
 611/*
 612 * page frame walker
 613 */
 614
 615static int hash_slot(uint64_t flags)
 616{
 617        int k = HASH_KEY(flags);
 618        int i;
 619
 620        /* Explicitly reserve slot 0 for flags 0: the following logic
 621         * cannot distinguish an unoccupied slot from slot (flags==0).
 622         */
 623        if (flags == 0)
 624                return 0;
 625
 626        /* search through the remaining (HASH_SIZE-1) slots */
 627        for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 628                if (!k || k >= ARRAY_SIZE(page_flags))
 629                        k = 1;
 630                if (page_flags[k] == 0) {
 631                        page_flags[k] = flags;
 632                        return k;
 633                }
 634                if (page_flags[k] == flags)
 635                        return k;
 636        }
 637
 638        fatal("hash table full: bump up HASH_SHIFT?\n");
 639        exit(EXIT_FAILURE);
 640}
 641
 642static void add_page(unsigned long voffset,
 643                     unsigned long offset, uint64_t flags)
 644{
 645        flags = kpageflags_flags(flags);
 646
 647        if (!bit_mask_ok(flags))
 648                return;
 649
 650        if (opt_hwpoison)
 651                hwpoison_page(offset);
 652        if (opt_unpoison)
 653                unpoison_page(offset);
 654
 655        if (opt_list == 1)
 656                show_page_range(voffset, offset, flags);
 657        else if (opt_list == 2)
 658                show_page(voffset, offset, flags);
 659
 660        nr_pages[hash_slot(flags)]++;
 661        total_pages++;
 662}
 663
 664#define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 665static void walk_pfn(unsigned long voffset,
 666                     unsigned long index,
 667                     unsigned long count)
 668{
 669        uint64_t buf[KPAGEFLAGS_BATCH];
 670        unsigned long batch;
 671        long pages;
 672        unsigned long i;
 673
 674        while (count) {
 675                batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 676                pages = kpageflags_read(buf, index, batch);
 677                if (pages == 0)
 678                        break;
 679
 680                for (i = 0; i < pages; i++)
 681                        add_page(voffset + i, index + i, buf[i]);
 682
 683                index += pages;
 684                count -= pages;
 685        }
 686}
 687
 688#define PAGEMAP_BATCH   (64 << 10)
 689static void walk_vma(unsigned long index, unsigned long count)
 690{
 691        uint64_t buf[PAGEMAP_BATCH];
 692        unsigned long batch;
 693        unsigned long pages;
 694        unsigned long pfn;
 695        unsigned long i;
 696
 697        while (count) {
 698                batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 699                pages = pagemap_read(buf, index, batch);
 700                if (pages == 0)
 701                        break;
 702
 703                for (i = 0; i < pages; i++) {
 704                        pfn = pagemap_pfn(buf[i]);
 705                        if (pfn)
 706                                walk_pfn(index + i, pfn, 1);
 707                }
 708
 709                index += pages;
 710                count -= pages;
 711        }
 712}
 713
 714static void walk_task(unsigned long index, unsigned long count)
 715{
 716        const unsigned long end = index + count;
 717        unsigned long start;
 718        int i = 0;
 719
 720        while (index < end) {
 721
 722                while (pg_end[i] <= index)
 723                        if (++i >= nr_vmas)
 724                                return;
 725                if (pg_start[i] >= end)
 726                        return;
 727
 728                start = max_t(unsigned long, pg_start[i], index);
 729                index = min_t(unsigned long, pg_end[i], end);
 730
 731                assert(start < index);
 732                walk_vma(start, index - start);
 733        }
 734}
 735
 736static void add_addr_range(unsigned long offset, unsigned long size)
 737{
 738        if (nr_addr_ranges >= MAX_ADDR_RANGES)
 739                fatal("too many addr ranges\n");
 740
 741        opt_offset[nr_addr_ranges] = offset;
 742        opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 743        nr_addr_ranges++;
 744}
 745
 746static void walk_addr_ranges(void)
 747{
 748        int i;
 749
 750        kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 751
 752        if (!nr_addr_ranges)
 753                add_addr_range(0, ULONG_MAX);
 754
 755        for (i = 0; i < nr_addr_ranges; i++)
 756                if (!opt_pid)
 757                        walk_pfn(0, opt_offset[i], opt_size[i]);
 758                else
 759                        walk_task(opt_offset[i], opt_size[i]);
 760
 761        close(kpageflags_fd);
 762}
 763
 764
 765/*
 766 * user interface
 767 */
 768
 769static const char *page_flag_type(uint64_t flag)
 770{
 771        if (flag & KPF_HACKERS_BITS)
 772                return "(r)";
 773        if (flag & KPF_OVERLOADED_BITS)
 774                return "(o)";
 775        return "   ";
 776}
 777
 778static void usage(void)
 779{
 780        int i, j;
 781
 782        printf(
 783"page-types [options]\n"
 784"            -r|--raw                   Raw mode, for kernel developers\n"
 785"            -d|--describe flags        Describe flags\n"
 786"            -a|--addr    addr-spec     Walk a range of pages\n"
 787"            -b|--bits    bits-spec     Walk pages with specified bits\n"
 788"            -p|--pid     pid           Walk process address space\n"
 789#if 0 /* planned features */
 790"            -f|--file    filename      Walk file address space\n"
 791#endif
 792"            -l|--list                  Show page details in ranges\n"
 793"            -L|--list-each             Show page details one by one\n"
 794"            -N|--no-summary            Don't show summary info\n"
 795"            -X|--hwpoison              hwpoison pages\n"
 796"            -x|--unpoison              unpoison pages\n"
 797"            -h|--help                  Show this usage message\n"
 798"flags:\n"
 799"            0x10                       bitfield format, e.g.\n"
 800"            anon                       bit-name, e.g.\n"
 801"            0x10,anon                  comma-separated list, e.g.\n"
 802"addr-spec:\n"
 803"            N                          one page at offset N (unit: pages)\n"
 804"            N+M                        pages range from N to N+M-1\n"
 805"            N,M                        pages range from N to M-1\n"
 806"            N,                         pages range from N to end\n"
 807"            ,M                         pages range from 0 to M-1\n"
 808"bits-spec:\n"
 809"            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 810"            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 811"            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 812"            =bit1,bit2                 flags == (bit1|bit2)\n"
 813"bit-names:\n"
 814        );
 815
 816        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 817                if (!page_flag_names[i])
 818                        continue;
 819                printf("%16s%s", page_flag_names[i] + 2,
 820                                 page_flag_type(1ULL << i));
 821                if (++j > 3) {
 822                        j = 0;
 823                        putchar('\n');
 824                }
 825        }
 826        printf("\n                                   "
 827                "(r) raw mode bits  (o) overloaded bits\n");
 828}
 829
 830static unsigned long long parse_number(const char *str)
 831{
 832        unsigned long long n;
 833
 834        n = strtoll(str, NULL, 0);
 835
 836        if (n == 0 && str[0] != '0')
 837                fatal("invalid name or number: %s\n", str);
 838
 839        return n;
 840}
 841
 842static void parse_pid(const char *str)
 843{
 844        FILE *file;
 845        char buf[5000];
 846
 847        opt_pid = parse_number(str);
 848
 849        sprintf(buf, "/proc/%d/pagemap", opt_pid);
 850        pagemap_fd = checked_open(buf, O_RDONLY);
 851
 852        sprintf(buf, "/proc/%d/maps", opt_pid);
 853        file = fopen(buf, "r");
 854        if (!file) {
 855                perror(buf);
 856                exit(EXIT_FAILURE);
 857        }
 858
 859        while (fgets(buf, sizeof(buf), file) != NULL) {
 860                unsigned long vm_start;
 861                unsigned long vm_end;
 862                unsigned long long pgoff;
 863                int major, minor;
 864                char r, w, x, s;
 865                unsigned long ino;
 866                int n;
 867
 868                n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 869                           &vm_start,
 870                           &vm_end,
 871                           &r, &w, &x, &s,
 872                           &pgoff,
 873                           &major, &minor,
 874                           &ino);
 875                if (n < 10) {
 876                        fprintf(stderr, "unexpected line: %s\n", buf);
 877                        continue;
 878                }
 879                pg_start[nr_vmas] = vm_start / page_size;
 880                pg_end[nr_vmas] = vm_end / page_size;
 881                if (++nr_vmas >= MAX_VMAS) {
 882                        fprintf(stderr, "too many VMAs\n");
 883                        break;
 884                }
 885        }
 886        fclose(file);
 887}
 888
 889static void parse_file(const char *name)
 890{
 891}
 892
 893static void parse_addr_range(const char *optarg)
 894{
 895        unsigned long offset;
 896        unsigned long size;
 897        char *p;
 898
 899        p = strchr(optarg, ',');
 900        if (!p)
 901                p = strchr(optarg, '+');
 902
 903        if (p == optarg) {
 904                offset = 0;
 905                size   = parse_number(p + 1);
 906        } else if (p) {
 907                offset = parse_number(optarg);
 908                if (p[1] == '\0')
 909                        size = ULONG_MAX;
 910                else {
 911                        size = parse_number(p + 1);
 912                        if (*p == ',') {
 913                                if (size < offset)
 914                                        fatal("invalid range: %lu,%lu\n",
 915                                                        offset, size);
 916                                size -= offset;
 917                        }
 918                }
 919        } else {
 920                offset = parse_number(optarg);
 921                size   = 1;
 922        }
 923
 924        add_addr_range(offset, size);
 925}
 926
 927static void add_bits_filter(uint64_t mask, uint64_t bits)
 928{
 929        if (nr_bit_filters >= MAX_BIT_FILTERS)
 930                fatal("too much bit filters\n");
 931
 932        opt_mask[nr_bit_filters] = mask;
 933        opt_bits[nr_bit_filters] = bits;
 934        nr_bit_filters++;
 935}
 936
 937static uint64_t parse_flag_name(const char *str, int len)
 938{
 939        int i;
 940
 941        if (!*str || !len)
 942                return 0;
 943
 944        if (len <= 8 && !strncmp(str, "compound", len))
 945                return BITS_COMPOUND;
 946
 947        for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 948                if (!page_flag_names[i])
 949                        continue;
 950                if (!strncmp(str, page_flag_names[i] + 2, len))
 951                        return 1ULL << i;
 952        }
 953
 954        return parse_number(str);
 955}
 956
 957static uint64_t parse_flag_names(const char *str, int all)
 958{
 959        const char *p    = str;
 960        uint64_t   flags = 0;
 961
 962        while (1) {
 963                if (*p == ',' || *p == '=' || *p == '\0') {
 964                        if ((*str != '~') || (*str == '~' && all && *++str))
 965                                flags |= parse_flag_name(str, p - str);
 966                        if (*p != ',')
 967                                break;
 968                        str = p + 1;
 969                }
 970                p++;
 971        }
 972
 973        return flags;
 974}
 975
 976static void parse_bits_mask(const char *optarg)
 977{
 978        uint64_t mask;
 979        uint64_t bits;
 980        const char *p;
 981
 982        p = strchr(optarg, '=');
 983        if (p == optarg) {
 984                mask = KPF_ALL_BITS;
 985                bits = parse_flag_names(p + 1, 0);
 986        } else if (p) {
 987                mask = parse_flag_names(optarg, 0);
 988                bits = parse_flag_names(p + 1, 0);
 989        } else if (strchr(optarg, '~')) {
 990                mask = parse_flag_names(optarg, 1);
 991                bits = parse_flag_names(optarg, 0);
 992        } else {
 993                mask = parse_flag_names(optarg, 0);
 994                bits = KPF_ALL_BITS;
 995        }
 996
 997        add_bits_filter(mask, bits);
 998}
 999
1000static void describe_flags(const char *optarg)
1001{
1002        uint64_t flags = parse_flag_names(optarg, 0);
1003
1004        printf("0x%016llx\t%s\t%s\n",
1005                (unsigned long long)flags,
1006                page_flag_name(flags),
1007                page_flag_longname(flags));
1008}
1009
1010static const struct option opts[] = {
1011        { "raw"       , 0, NULL, 'r' },
1012        { "pid"       , 1, NULL, 'p' },
1013        { "file"      , 1, NULL, 'f' },
1014        { "addr"      , 1, NULL, 'a' },
1015        { "bits"      , 1, NULL, 'b' },
1016        { "describe"  , 1, NULL, 'd' },
1017        { "list"      , 0, NULL, 'l' },
1018        { "list-each" , 0, NULL, 'L' },
1019        { "no-summary", 0, NULL, 'N' },
1020        { "hwpoison"  , 0, NULL, 'X' },
1021        { "unpoison"  , 0, NULL, 'x' },
1022        { "help"      , 0, NULL, 'h' },
1023        { NULL        , 0, NULL, 0 }
1024};
1025
1026int main(int argc, char *argv[])
1027{
1028        int c;
1029
1030        page_size = getpagesize();
1031
1032        while ((c = getopt_long(argc, argv,
1033                                "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1034                switch (c) {
1035                case 'r':
1036                        opt_raw = 1;
1037                        break;
1038                case 'p':
1039                        parse_pid(optarg);
1040                        break;
1041                case 'f':
1042                        parse_file(optarg);
1043                        break;
1044                case 'a':
1045                        parse_addr_range(optarg);
1046                        break;
1047                case 'b':
1048                        parse_bits_mask(optarg);
1049                        break;
1050                case 'd':
1051                        describe_flags(optarg);
1052                        exit(0);
1053                case 'l':
1054                        opt_list = 1;
1055                        break;
1056                case 'L':
1057                        opt_list = 2;
1058                        break;
1059                case 'N':
1060                        opt_no_summary = 1;
1061                        break;
1062                case 'X':
1063                        opt_hwpoison = 1;
1064                        prepare_hwpoison_fd();
1065                        break;
1066                case 'x':
1067                        opt_unpoison = 1;
1068                        prepare_hwpoison_fd();
1069                        break;
1070                case 'h':
1071                        usage();
1072                        exit(0);
1073                default:
1074                        usage();
1075                        exit(1);
1076                }
1077        }
1078
1079        if (opt_list && opt_pid)
1080                printf("voffset\t");
1081        if (opt_list == 1)
1082                printf("offset\tlen\tflags\n");
1083        if (opt_list == 2)
1084                printf("offset\tflags\n");
1085
1086        walk_addr_ranges();
1087
1088        if (opt_list == 1)
1089                show_page_range(0, 0, 0);  /* drain the buffer */
1090
1091        if (opt_no_summary)
1092                return 0;
1093
1094        if (opt_list)
1095                printf("\n\n");
1096
1097        show_summary();
1098
1099        return 0;
1100}
1101
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