tools/mm/page-types.c

   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 /* [47-] take some arbitrary free slots for expanding overloaded flags
  84  * not part of kernel API
  85  */
  86 #define KPF_ANON_EXCLUSIVE      47
  87 #define KPF_READAHEAD           48
  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
 100 static 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_ANON_EXCLUSIVE]    = "d:anon_exclusive",
 142         [KPF_READAHEAD]         = "I:readahead",
 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
 156 static int              opt_raw;        /* for kernel developers */
 157 static int              opt_list;       /* list pages (in ranges) */
 158 static int              opt_mark_idle;  /* set accessed bit */
 159 static int              opt_no_summary; /* don't show summary */
 160 static pid_t            opt_pid;        /* process to walk */
 161 const char              *opt_file;      /* file or directory path */
 162 static uint64_t         opt_cgroup;     /* cgroup inode */
 163 static int              opt_list_cgroup;/* list page cgroup */
 164 static int              opt_list_mapcnt;/* list page map count */
 165 static const char       *opt_kpageflags;/* kpageflags file to parse */
 166
 167 #define MAX_ADDR_RANGES 1024
 168 static int              nr_addr_ranges;
 169 static unsigned long    opt_offset[MAX_ADDR_RANGES];
 170 static unsigned long    opt_size[MAX_ADDR_RANGES];
 171
 172 #define MAX_VMAS        10240
 173 static int              nr_vmas;
 174 static unsigned long    pg_start[MAX_VMAS];
 175 static unsigned long    pg_end[MAX_VMAS];
 176
 177 #define MAX_BIT_FILTERS 64
 178 static int              nr_bit_filters;
 179 static uint64_t         opt_mask[MAX_BIT_FILTERS];
 180 static uint64_t         opt_bits[MAX_BIT_FILTERS];
 181
 182 static int              page_size;
 183
 184 static int              pagemap_fd;
 185 static int              kpageflags_fd;
 186 static int              kpagecount_fd = -1;
 187 static int              kpagecgroup_fd = -1;
 188 static int              page_idle_fd = -1;
 189
 190 static int              opt_hwpoison;
 191 static int              opt_unpoison;
 192
 193 static const char       *hwpoison_debug_fs;
 194 static int              hwpoison_inject_fd;
 195 static 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
 202 static unsigned long    total_pages;
 203 static unsigned long    nr_pages[HASH_SIZE];
 204 static 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
 223 static unsigned long pages2mb(unsigned long pages)
 224 {
 225         return (pages * page_size) >> 20;
 226 }
 227
 228 static 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
 238 static 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
 254 static 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
 275 static 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
 282 static 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
 292 static 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
 301 static 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
 308 static 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
 320 static 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
 329 static 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
 348 static 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
 372 static 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
 410 static void flush_page_range(void)
 411 {
 412         show_page_range(0, 0, 0, 0, 0, 0);
 413 }
 414
 415 static 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
 430 static 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
 456 static 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
 473 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
 474 {
 475         /* Anonymous pages overload PG_mappedtodisk */
 476         if ((flags & BIT(ANON)) && (flags & BIT(MAPPEDTODISK)))
 477                 flags ^= BIT(MAPPEDTODISK) | BIT(ANON_EXCLUSIVE);
 478
 479         /* SLUB overloads several page flags */
 480         if (flags & BIT(SLAB)) {
 481                 if (flags & BIT(ACTIVE))
 482                         flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 483                 if (flags & BIT(ERROR))
 484                         flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 485         }
 486
 487         /* PG_reclaim is overloaded as PG_readahead in the read path */
 488         if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 489                 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 490
 491         if (pme & PM_SOFT_DIRTY)
 492                 flags |= BIT(SOFTDIRTY);
 493         if (pme & PM_FILE)
 494                 flags |= BIT(FILE);
 495         if (pme & PM_SWAP)
 496                 flags |= BIT(SWAP);
 497         if (pme & PM_MMAP_EXCLUSIVE)
 498                 flags |= BIT(MMAP_EXCLUSIVE);
 499
 500         return flags;
 501 }
 502
 503 static uint64_t well_known_flags(uint64_t flags)
 504 {
 505         /* hide flags intended only for kernel hacker */
 506         flags &= ~KPF_HACKERS_BITS;
 507
 508         /* hide non-hugeTLB compound pages */
 509         if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 510                 flags &= ~BITS_COMPOUND;
 511
 512         return flags;
 513 }
 514
 515 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 516 {
 517         if (opt_raw)
 518                 flags = expand_overloaded_flags(flags, pme);
 519         else
 520                 flags = well_known_flags(flags);
 521
 522         return flags;
 523 }
 524
 525 /*
 526  * page actions
 527  */
 528
 529 static void prepare_hwpoison_fd(void)
 530 {
 531         char buf[MAX_PATH + 1];
 532
 533         hwpoison_debug_fs = debugfs__mount();
 534         if (!hwpoison_debug_fs) {
 535                 perror("mount debugfs");
 536                 exit(EXIT_FAILURE);
 537         }
 538
 539         if (opt_hwpoison && !hwpoison_inject_fd) {
 540                 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 541                         hwpoison_debug_fs);
 542                 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 543         }
 544
 545         if (opt_unpoison && !hwpoison_forget_fd) {
 546                 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 547                         hwpoison_debug_fs);
 548                 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 549         }
 550 }
 551
 552 static int hwpoison_page(unsigned long offset)
 553 {
 554         char buf[100];
 555         int len;
 556
 557         len = sprintf(buf, "0x%lx\n", offset);
 558         len = write(hwpoison_inject_fd, buf, len);
 559         if (len < 0) {
 560                 perror("hwpoison inject");
 561                 return len;
 562         }
 563         return 0;
 564 }
 565
 566 static int unpoison_page(unsigned long offset)
 567 {
 568         char buf[100];
 569         int len;
 570
 571         len = sprintf(buf, "0x%lx\n", offset);
 572         len = write(hwpoison_forget_fd, buf, len);
 573         if (len < 0) {
 574                 perror("hwpoison forget");
 575                 return len;
 576         }
 577         return 0;
 578 }
 579
 580 static int mark_page_idle(unsigned long offset)
 581 {
 582         static unsigned long off;
 583         static uint64_t buf;
 584         int len;
 585
 586         if ((offset / 64 == off / 64) || buf == 0) {
 587                 buf |= 1UL << (offset % 64);
 588                 off = offset;
 589                 return 0;
 590         }
 591
 592         len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
 593         if (len < 0) {
 594                 perror("mark page idle");
 595                 return len;
 596         }
 597
 598         buf = 1UL << (offset % 64);
 599         off = offset;
 600
 601         return 0;
 602 }
 603
 604 /*
 605  * page frame walker
 606  */
 607
 608 static size_t hash_slot(uint64_t flags)
 609 {
 610         size_t k = HASH_KEY(flags);
 611         size_t i;
 612
 613         /* Explicitly reserve slot 0 for flags 0: the following logic
 614          * cannot distinguish an unoccupied slot from slot (flags==0).
 615          */
 616         if (flags == 0)
 617                 return 0;
 618
 619         /* search through the remaining (HASH_SIZE-1) slots */
 620         for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 621                 if (!k || k >= ARRAY_SIZE(page_flags))
 622                         k = 1;
 623                 if (page_flags[k] == 0) {
 624                         page_flags[k] = flags;
 625                         return k;
 626                 }
 627                 if (page_flags[k] == flags)
 628                         return k;
 629         }
 630
 631         fatal("hash table full: bump up HASH_SHIFT?\n");
 632         exit(EXIT_FAILURE);
 633 }
 634
 635 static void add_page(unsigned long voffset, unsigned long offset,
 636                      uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
 637                      uint64_t pme)
 638 {
 639         flags = kpageflags_flags(flags, pme);
 640
 641         if (!bit_mask_ok(flags))
 642                 return;
 643
 644         if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
 645                 return;
 646
 647         if (opt_hwpoison)
 648                 hwpoison_page(offset);
 649         if (opt_unpoison)
 650                 unpoison_page(offset);
 651
 652         if (opt_mark_idle)
 653                 mark_page_idle(offset);
 654
 655         if (opt_list == 1)
 656                 show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
 657         else if (opt_list == 2)
 658                 show_page(voffset, offset, flags, cgroup, mapcnt);
 659
 660         nr_pages[hash_slot(flags)]++;
 661         total_pages++;
 662 }
 663
 664 #define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
 665 static void walk_pfn(unsigned long voffset,
 666                      unsigned long index,
 667                      unsigned long count,
 668                      uint64_t pme)
 669 {
 670         uint64_t buf[KPAGEFLAGS_BATCH];
 671         uint64_t cgi[KPAGEFLAGS_BATCH];
 672         uint64_t cnt[KPAGEFLAGS_BATCH];
 673         unsigned long batch;
 674         unsigned long pages;
 675         unsigned long i;
 676
 677         /*
 678          * kpagecgroup_read() reads only if kpagecgroup were opened, but
 679          * /proc/kpagecgroup might even not exist, so it's better to fill
 680          * them with zeros here.
 681          */
 682         if (count == 1)
 683                 cgi[0] = 0;
 684         else
 685                 memset(cgi, 0, sizeof cgi);
 686
 687         while (count) {
 688                 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 689                 pages = kpageflags_read(buf, index, batch);
 690                 if (pages == 0)
 691                         break;
 692
 693                 if (kpagecgroup_read(cgi, index, pages) != pages)
 694                         fatal("kpagecgroup returned fewer pages than expected");
 695
 696                 if (kpagecount_read(cnt, index, pages) != pages)
 697                         fatal("kpagecount returned fewer pages than expected");
 698
 699                 for (i = 0; i < pages; i++)
 700                         add_page(voffset + i, index + i,
 701                                  buf[i], cgi[i], cnt[i], pme);
 702
 703                 index += pages;
 704                 count -= pages;
 705         }
 706 }
 707
 708 static void walk_swap(unsigned long voffset, uint64_t pme)
 709 {
 710         uint64_t flags = kpageflags_flags(0, pme);
 711
 712         if (!bit_mask_ok(flags))
 713                 return;
 714
 715         if (opt_cgroup)
 716                 return;
 717
 718         if (opt_list == 1)
 719                 show_page_range(voffset, pagemap_swap_offset(pme),
 720                                 1, flags, 0, 0);
 721         else if (opt_list == 2)
 722                 show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
 723
 724         nr_pages[hash_slot(flags)]++;
 725         total_pages++;
 726 }
 727
 728 #define PAGEMAP_BATCH   (64 << 10)
 729 static void walk_vma(unsigned long index, unsigned long count)
 730 {
 731         uint64_t buf[PAGEMAP_BATCH];
 732         unsigned long batch;
 733         unsigned long pages;
 734         unsigned long pfn;
 735         unsigned long i;
 736
 737         while (count) {
 738                 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 739                 pages = pagemap_read(buf, index, batch);
 740                 if (pages == 0)
 741                         break;
 742
 743                 for (i = 0; i < pages; i++) {
 744                         pfn = pagemap_pfn(buf[i]);
 745                         if (pfn)
 746                                 walk_pfn(index + i, pfn, 1, buf[i]);
 747                         if (buf[i] & PM_SWAP)
 748                                 walk_swap(index + i, buf[i]);
 749                 }
 750
 751                 index += pages;
 752                 count -= pages;
 753         }
 754 }
 755
 756 static void walk_task(unsigned long index, unsigned long count)
 757 {
 758         const unsigned long end = index + count;
 759         unsigned long start;
 760         int i = 0;
 761
 762         while (index < end) {
 763
 764                 while (pg_end[i] <= index)
 765                         if (++i >= nr_vmas)
 766                                 return;
 767                 if (pg_start[i] >= end)
 768                         return;
 769
 770                 start = max_t(unsigned long, pg_start[i], index);
 771                 index = min_t(unsigned long, pg_end[i], end);
 772
 773                 assert(start < index);
 774                 walk_vma(start, index - start);
 775         }
 776 }
 777
 778 static void add_addr_range(unsigned long offset, unsigned long size)
 779 {
 780         if (nr_addr_ranges >= MAX_ADDR_RANGES)
 781                 fatal("too many addr ranges\n");
 782
 783         opt_offset[nr_addr_ranges] = offset;
 784         opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 785         nr_addr_ranges++;
 786 }
 787
 788 static void walk_addr_ranges(void)
 789 {
 790         int i;
 791
 792         kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
 793
 794         if (!nr_addr_ranges)
 795                 add_addr_range(0, ULONG_MAX);
 796
 797         for (i = 0; i < nr_addr_ranges; i++)
 798                 if (!opt_pid)
 799                         walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 800                 else
 801                         walk_task(opt_offset[i], opt_size[i]);
 802
 803         if (opt_mark_idle)
 804                 mark_page_idle(0);
 805
 806         close(kpageflags_fd);
 807 }
 808
 809
 810 /*
 811  * user interface
 812  */
 813
 814 static const char *page_flag_type(uint64_t flag)
 815 {
 816         if (flag & KPF_HACKERS_BITS)
 817                 return "(r)";
 818         if (flag & KPF_OVERLOADED_BITS)
 819                 return "(o)";
 820         return "   ";
 821 }
 822
 823 static void usage(void)
 824 {
 825         size_t i, j;
 826
 827         printf(
 828 "page-types [options]\n"
 829 "            -r|--raw                   Raw mode, for kernel developers\n"
 830 "            -d|--describe flags        Describe flags\n"
 831 "            -a|--addr    addr-spec     Walk a range of pages\n"
 832 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
 833 "            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
 834 "            -p|--pid     pid           Walk process address space\n"
 835 "            -f|--file    filename      Walk file address space\n"
 836 "            -i|--mark-idle             Mark pages idle\n"
 837 "            -l|--list                  Show page details in ranges\n"
 838 "            -L|--list-each             Show page details one by one\n"
 839 "            -C|--list-cgroup           Show cgroup inode for pages\n"
 840 "            -M|--list-mapcnt           Show page map count\n"
 841 "            -N|--no-summary            Don't show summary info\n"
 842 "            -X|--hwpoison              hwpoison pages\n"
 843 "            -x|--unpoison              unpoison pages\n"
 844 "            -F|--kpageflags filename   kpageflags file to parse\n"
 845 "            -h|--help                  Show this usage message\n"
 846 "flags:\n"
 847 "            0x10                       bitfield format, e.g.\n"
 848 "            anon                       bit-name, e.g.\n"
 849 "            0x10,anon                  comma-separated list, e.g.\n"
 850 "addr-spec:\n"
 851 "            N                          one page at offset N (unit: pages)\n"
 852 "            N+M                        pages range from N to N+M-1\n"
 853 "            N,M                        pages range from N to M-1\n"
 854 "            N,                         pages range from N to end\n"
 855 "            ,M                         pages range from 0 to M-1\n"
 856 "bits-spec:\n"
 857 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 858 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 859 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 860 "            =bit1,bit2                 flags == (bit1|bit2)\n"
 861 "bit-names:\n"
 862         );
 863
 864         for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 865                 if (!page_flag_names[i])
 866                         continue;
 867                 printf("%16s%s", page_flag_names[i] + 2,
 868                                  page_flag_type(1ULL << i));
 869                 if (++j > 3) {
 870                         j = 0;
 871                         putchar('\n');
 872                 }
 873         }
 874         printf("\n                                   "
 875                 "(r) raw mode bits  (o) overloaded bits\n");
 876 }
 877
 878 static unsigned long long parse_number(const char *str)
 879 {
 880         unsigned long long n;
 881
 882         n = strtoll(str, NULL, 0);
 883
 884         if (n == 0 && str[0] != '0')
 885                 fatal("invalid name or number: %s\n", str);
 886
 887         return n;
 888 }
 889
 890 static void parse_pid(const char *str)
 891 {
 892         FILE *file;
 893         char buf[5000];
 894
 895         opt_pid = parse_number(str);
 896
 897         sprintf(buf, "/proc/%d/pagemap", opt_pid);
 898         pagemap_fd = checked_open(buf, O_RDONLY);
 899
 900         sprintf(buf, "/proc/%d/maps", opt_pid);
 901         file = fopen(buf, "r");
 902         if (!file) {
 903                 perror(buf);
 904                 exit(EXIT_FAILURE);
 905         }
 906
 907         while (fgets(buf, sizeof(buf), file) != NULL) {
 908                 unsigned long vm_start;
 909                 unsigned long vm_end;
 910                 unsigned long long pgoff;
 911                 int major, minor;
 912                 char r, w, x, s;
 913                 unsigned long ino;
 914                 int n;
 915
 916                 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 917                            &vm_start,
 918                            &vm_end,
 919                            &r, &w, &x, &s,
 920                            &pgoff,
 921                            &major, &minor,
 922                            &ino);
 923                 if (n < 10) {
 924                         fprintf(stderr, "unexpected line: %s\n", buf);
 925                         continue;
 926                 }
 927                 pg_start[nr_vmas] = vm_start / page_size;
 928                 pg_end[nr_vmas] = vm_end / page_size;
 929                 if (++nr_vmas >= MAX_VMAS) {
 930                         fprintf(stderr, "too many VMAs\n");
 931                         break;
 932                 }
 933         }
 934         fclose(file);
 935 }
 936
 937 static void show_file(const char *name, const struct stat *st)
 938 {
 939         unsigned long long size = st->st_size;
 940         char atime[64], mtime[64];
 941         long now = time(NULL);
 942
 943         printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 944                         name, (unsigned)st->st_ino,
 945                         size, (size + page_size - 1) / page_size);
 946
 947         strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 948         strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 949
 950         printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 951                         mtime, now - st->st_mtime,
 952                         atime, now - st->st_atime);
 953 }
 954
 955 static sigjmp_buf sigbus_jmp;
 956
 957 static void * volatile sigbus_addr;
 958
 959 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 960 {
 961         (void)sig;
 962         (void)ucontex;
 963         sigbus_addr = info ? info->si_addr : NULL;
 964         siglongjmp(sigbus_jmp, 1);
 965 }
 966
 967 static struct sigaction sigbus_action = {
 968         .sa_sigaction = sigbus_handler,
 969         .sa_flags = SA_SIGINFO,
 970 };
 971
 972 static void walk_file_range(const char *name, int fd,
 973                             unsigned long off, unsigned long end)
 974 {
 975         uint8_t vec[PAGEMAP_BATCH];
 976         uint64_t buf[PAGEMAP_BATCH], flags;
 977         uint64_t cgroup = 0;
 978         uint64_t mapcnt = 0;
 979         unsigned long nr_pages, pfn, i;
 980         ssize_t len;
 981         void *ptr;
 982         int first = 1;
 983
 984         for (; off < end; off += len) {
 985                 nr_pages = (end - off + page_size - 1) / page_size;
 986                 if (nr_pages > PAGEMAP_BATCH)
 987                         nr_pages = PAGEMAP_BATCH;
 988                 len = nr_pages * page_size;
 989
 990                 ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 991                 if (ptr == MAP_FAILED)
 992                         fatal("mmap failed: %s", name);
 993
 994                 /* determine cached pages */
 995                 if (mincore(ptr, len, vec))
 996                         fatal("mincore failed: %s", name);
 997
 998                 /* turn off readahead */
 999                 if (madvise(ptr, len, MADV_RANDOM))
1000                         fatal("madvice failed: %s", name);
1001
1002                 if (sigsetjmp(sigbus_jmp, 1)) {
1003                         end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1004                         fprintf(stderr, "got sigbus at offset %lld: %s\n",
1005                                         (long long)end, name);
1006                         goto got_sigbus;
1007                 }
1008
1009                 /* populate ptes */
1010                 for (i = 0; i < nr_pages ; i++) {
1011                         if (vec[i] & 1)
1012                                 (void)*(volatile int *)(ptr + i * page_size);
1013                 }
1014 got_sigbus:
1015
1016                 /* turn off harvesting reference bits */
1017                 if (madvise(ptr, len, MADV_SEQUENTIAL))
1018                         fatal("madvice failed: %s", name);
1019
1020                 if (pagemap_read(buf, (unsigned long)ptr / page_size,
1021                                         nr_pages) != nr_pages)
1022                         fatal("cannot read pagemap");
1023
1024                 munmap(ptr, len);
1025
1026                 for (i = 0; i < nr_pages; i++) {
1027                         pfn = pagemap_pfn(buf[i]);
1028                         if (!pfn)
1029                                 continue;
1030                         if (!kpageflags_read(&flags, pfn, 1))
1031                                 continue;
1032                         if (!kpagecgroup_read(&cgroup, pfn, 1))
1033                                 fatal("kpagecgroup_read failed");
1034                         if (!kpagecount_read(&mapcnt, pfn, 1))
1035                                 fatal("kpagecount_read failed");
1036                         if (first && opt_list) {
1037                                 first = 0;
1038                                 flush_page_range();
1039                         }
1040                         add_page(off / page_size + i, pfn,
1041                                  flags, cgroup, mapcnt, buf[i]);
1042                 }
1043         }
1044 }
1045
1046 static void walk_file(const char *name, const struct stat *st)
1047 {
1048         int i;
1049         int fd;
1050
1051         fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
1052
1053         if (!nr_addr_ranges)
1054                 add_addr_range(0, st->st_size / page_size);
1055
1056         for (i = 0; i < nr_addr_ranges; i++)
1057                 walk_file_range(name, fd, opt_offset[i] * page_size,
1058                                 (opt_offset[i] + opt_size[i]) * page_size);
1059
1060         close(fd);
1061 }
1062
1063 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1064 {
1065         (void)f;
1066         switch (type) {
1067         case FTW_F:
1068                 if (S_ISREG(st->st_mode))
1069                         walk_file(name, st);
1070                 break;
1071         case FTW_DNR:
1072                 fprintf(stderr, "cannot read dir: %s\n", name);
1073                 break;
1074         }
1075         return 0;
1076 }
1077
1078 struct stat st;
1079
1080 static void walk_page_cache(void)
1081 {
1082         kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1083         pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1084         sigaction(SIGBUS, &sigbus_action, NULL);
1085
1086         if (stat(opt_file, &st))
1087                 fatal("stat failed: %s\n", opt_file);
1088
1089         if (S_ISREG(st.st_mode)) {
1090                 walk_file(opt_file, &st);
1091         } else if (S_ISDIR(st.st_mode)) {
1092                 /* do not follow symlinks and mountpoints */
1093                 if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1094                         fatal("nftw failed: %s\n", opt_file);
1095         } else
1096                 fatal("unhandled file type: %s\n", opt_file);
1097
1098         close(kpageflags_fd);
1099         close(pagemap_fd);
1100         signal(SIGBUS, SIG_DFL);
1101 }
1102
1103 static void parse_file(const char *name)
1104 {
1105         opt_file = name;
1106 }
1107
1108 static void parse_cgroup(const char *path)
1109 {
1110         if (path[0] == '@') {
1111                 opt_cgroup = parse_number(path + 1);
1112                 return;
1113         }
1114
1115         struct stat st;
1116
1117         if (stat(path, &st))
1118                 fatal("stat failed: %s: %m\n", path);
1119
1120         if (!S_ISDIR(st.st_mode))
1121                 fatal("cgroup supposed to be a directory: %s\n", path);
1122
1123         opt_cgroup = st.st_ino;
1124 }
1125
1126 static void parse_addr_range(const char *optarg)
1127 {
1128         unsigned long offset;
1129         unsigned long size;
1130         char *p;
1131
1132         p = strchr(optarg, ',');
1133         if (!p)
1134                 p = strchr(optarg, '+');
1135
1136         if (p == optarg) {
1137                 offset = 0;
1138                 size   = parse_number(p + 1);
1139         } else if (p) {
1140                 offset = parse_number(optarg);
1141                 if (p[1] == '\0')
1142                         size = ULONG_MAX;
1143                 else {
1144                         size = parse_number(p + 1);
1145                         if (*p == ',') {
1146                                 if (size < offset)
1147                                         fatal("invalid range: %lu,%lu\n",
1148                                                         offset, size);
1149                                 size -= offset;
1150                         }
1151                 }
1152         } else {
1153                 offset = parse_number(optarg);
1154                 size   = 1;
1155         }
1156
1157         add_addr_range(offset, size);
1158 }
1159
1160 static void add_bits_filter(uint64_t mask, uint64_t bits)
1161 {
1162         if (nr_bit_filters >= MAX_BIT_FILTERS)
1163                 fatal("too much bit filters\n");
1164
1165         opt_mask[nr_bit_filters] = mask;
1166         opt_bits[nr_bit_filters] = bits;
1167         nr_bit_filters++;
1168 }
1169
1170 static uint64_t parse_flag_name(const char *str, int len)
1171 {
1172         size_t i;
1173
1174         if (!*str || !len)
1175                 return 0;
1176
1177         if (len <= 8 && !strncmp(str, "compound", len))
1178                 return BITS_COMPOUND;
1179
1180         for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1181                 if (!page_flag_names[i])
1182                         continue;
1183                 if (!strncmp(str, page_flag_names[i] + 2, len))
1184                         return 1ULL << i;
1185         }
1186
1187         return parse_number(str);
1188 }
1189
1190 static uint64_t parse_flag_names(const char *str, int all)
1191 {
1192         const char *p    = str;
1193         uint64_t   flags = 0;
1194
1195         while (1) {
1196                 if (*p == ',' || *p == '=' || *p == '\0') {
1197                         if ((*str != '~') || (*str == '~' && all && *++str))
1198                                 flags |= parse_flag_name(str, p - str);
1199                         if (*p != ',')
1200                                 break;
1201                         str = p + 1;
1202                 }
1203                 p++;
1204         }
1205
1206         return flags;
1207 }
1208
1209 static void parse_bits_mask(const char *optarg)
1210 {
1211         uint64_t mask;
1212         uint64_t bits;
1213         const char *p;
1214
1215         p = strchr(optarg, '=');
1216         if (p == optarg) {
1217                 mask = KPF_ALL_BITS;
1218                 bits = parse_flag_names(p + 1, 0);
1219         } else if (p) {
1220                 mask = parse_flag_names(optarg, 0);
1221                 bits = parse_flag_names(p + 1, 0);
1222         } else if (strchr(optarg, '~')) {
1223                 mask = parse_flag_names(optarg, 1);
1224                 bits = parse_flag_names(optarg, 0);
1225         } else {
1226                 mask = parse_flag_names(optarg, 0);
1227                 bits = KPF_ALL_BITS;
1228         }
1229
1230         add_bits_filter(mask, bits);
1231 }
1232
1233 static void parse_kpageflags(const char *name)
1234 {
1235         opt_kpageflags = name;
1236 }
1237
1238 static void describe_flags(const char *optarg)
1239 {
1240         uint64_t flags = parse_flag_names(optarg, 0);
1241
1242         printf("0x%016llx\t%s\t%s\n",
1243                 (unsigned long long)flags,
1244                 page_flag_name(flags),
1245                 page_flag_longname(flags));
1246 }
1247
1248 static const struct option opts[] = {
1249         { "raw"       , 0, NULL, 'r' },
1250         { "pid"       , 1, NULL, 'p' },
1251         { "file"      , 1, NULL, 'f' },
1252         { "addr"      , 1, NULL, 'a' },
1253         { "bits"      , 1, NULL, 'b' },
1254         { "cgroup"    , 1, NULL, 'c' },
1255         { "describe"  , 1, NULL, 'd' },
1256         { "mark-idle" , 0, NULL, 'i' },
1257         { "list"      , 0, NULL, 'l' },
1258         { "list-each" , 0, NULL, 'L' },
1259         { "list-cgroup", 0, NULL, 'C' },
1260         { "list-mapcnt", 0, NULL, 'M' },
1261         { "no-summary", 0, NULL, 'N' },
1262         { "hwpoison"  , 0, NULL, 'X' },
1263         { "unpoison"  , 0, NULL, 'x' },
1264         { "kpageflags", 0, NULL, 'F' },
1265         { "help"      , 0, NULL, 'h' },
1266         { NULL        , 0, NULL, 0 }
1267 };
1268
1269 int main(int argc, char *argv[])
1270 {
1271         int c;
1272
1273         page_size = getpagesize();
1274
1275         while ((c = getopt_long(argc, argv,
1276                                 "rp:f:a:b:d:c:CilLMNXxF:h",
1277                                 opts, NULL)) != -1) {
1278                 switch (c) {
1279                 case 'r':
1280                         opt_raw = 1;
1281                         break;
1282                 case 'p':
1283                         parse_pid(optarg);
1284                         break;
1285                 case 'f':
1286                         parse_file(optarg);
1287                         break;
1288                 case 'a':
1289                         parse_addr_range(optarg);
1290                         break;
1291                 case 'b':
1292                         parse_bits_mask(optarg);
1293                         break;
1294                 case 'c':
1295                         parse_cgroup(optarg);
1296                         break;
1297                 case 'C':
1298                         opt_list_cgroup = 1;
1299                         break;
1300                 case 'd':
1301                         describe_flags(optarg);
1302                         exit(0);
1303                 case 'i':
1304                         opt_mark_idle = 1;
1305                         break;
1306                 case 'l':
1307                         opt_list = 1;
1308                         break;
1309                 case 'L':
1310                         opt_list = 2;
1311                         break;
1312                 case 'M':
1313                         opt_list_mapcnt = 1;
1314                         break;
1315                 case 'N':
1316                         opt_no_summary = 1;
1317                         break;
1318                 case 'X':
1319                         opt_hwpoison = 1;
1320                         prepare_hwpoison_fd();
1321                         break;
1322                 case 'x':
1323                         opt_unpoison = 1;
1324                         prepare_hwpoison_fd();
1325                         break;
1326                 case 'F':
1327                         parse_kpageflags(optarg);
1328                         break;
1329                 case 'h':
1330                         usage();
1331                         exit(0);
1332                 default:
1333                         usage();
1334                         exit(1);
1335                 }
1336         }
1337
1338         if (!opt_kpageflags)
1339                 opt_kpageflags = PROC_KPAGEFLAGS;
1340
1341         if (opt_cgroup || opt_list_cgroup)
1342                 kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1343
1344         if (opt_list && opt_list_mapcnt)
1345                 kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1346
1347         if (opt_mark_idle)
1348                 page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1349
1350         if (opt_list && opt_pid)
1351                 printf("voffset\t");
1352         if (opt_list && opt_file)
1353                 printf("foffset\t");
1354         if (opt_list && opt_list_cgroup)
1355                 printf("cgroup\t");
1356         if (opt_list && opt_list_mapcnt)
1357                 printf("map-cnt\t");
1358
1359         if (opt_list == 1)
1360                 printf("offset\tlen\tflags\n");
1361         if (opt_list == 2)
1362                 printf("offset\tflags\n");
1363
1364         if (opt_file)
1365                 walk_page_cache();
1366         else
1367                 walk_addr_ranges();
1368
1369         if (opt_list == 1)
1370                 flush_page_range();
1371
1372         if (opt_no_summary)
1373                 return 0;
1374
1375         if (opt_list)
1376                 printf("\n\n");
1377
1378         if (opt_file) {
1379                 show_file(opt_file, &st);
1380                 printf("\n");
1381         }
1382
1383         show_summary();
1384
1385         if (opt_list_mapcnt)
1386                 close(kpagecount_fd);
1387
1388         if (page_idle_fd >= 0)
1389                 close(page_idle_fd);
1390
1391         return 0;
1392 }