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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}