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