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/debugfs.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 sizeof(uint64_t)
61 #define PM_STATUS_BITS 3
62 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
63 #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
64 #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
65 #define PM_PSHIFT_BITS 6
66 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
67 #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
68 #define __PM_PSHIFT(x) (((uint64_t) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
69 #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
70 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
71
72 #define __PM_SOFT_DIRTY (1LL)
73 #define PM_PRESENT PM_STATUS(4LL)
74 #define PM_SWAP PM_STATUS(2LL)
75 #define PM_SOFT_DIRTY __PM_PSHIFT(__PM_SOFT_DIRTY)
76
77
78 /*
79 * kernel page flags
80 */
81
82 #define KPF_BYTES 8
83 #define PROC_KPAGEFLAGS "/proc/kpageflags"
84
85 /* [32-] kernel hacking assistances */
86 #define KPF_RESERVED 32
87 #define KPF_MLOCKED 33
88 #define KPF_MAPPEDTODISK 34
89 #define KPF_PRIVATE 35
90 #define KPF_PRIVATE_2 36
91 #define KPF_OWNER_PRIVATE 37
92 #define KPF_ARCH 38
93 #define KPF_UNCACHED 39
94 #define KPF_SOFTDIRTY 40
95
96 /* [48-] take some arbitrary free slots for expanding overloaded flags
97 * not part of kernel API
98 */
99 #define KPF_READAHEAD 48
100 #define KPF_SLOB_FREE 49
101 #define KPF_SLUB_FROZEN 50
102 #define KPF_SLUB_DEBUG 51
103
104 #define KPF_ALL_BITS ((uint64_t)~0ULL)
105 #define KPF_HACKERS_BITS (0xffffULL << 32)
106 #define KPF_OVERLOADED_BITS (0xffffULL << 48)
107 #define BIT(name) (1ULL << KPF_##name)
108 #define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
109
110 static const char * const page_flag_names[] = {
111 [KPF_LOCKED] = "L:locked",
112 [KPF_ERROR] = "E:error",
113 [KPF_REFERENCED] = "R:referenced",
114 [KPF_UPTODATE] = "U:uptodate",
115 [KPF_DIRTY] = "D:dirty",
116 [KPF_LRU] = "l:lru",
117 [KPF_ACTIVE] = "A:active",
118 [KPF_SLAB] = "S:slab",
119 [KPF_WRITEBACK] = "W:writeback",
120 [KPF_RECLAIM] = "I:reclaim",
121 [KPF_BUDDY] = "B:buddy",
122
123 [KPF_MMAP] = "M:mmap",
124 [KPF_ANON] = "a:anonymous",
125 [KPF_SWAPCACHE] = "s:swapcache",
126 [KPF_SWAPBACKED] = "b:swapbacked",
127 [KPF_COMPOUND_HEAD] = "H:compound_head",
128 [KPF_COMPOUND_TAIL] = "T:compound_tail",
129 [KPF_HUGE] = "G:huge",
130 [KPF_UNEVICTABLE] = "u:unevictable",
131 [KPF_HWPOISON] = "X:hwpoison",
132 [KPF_NOPAGE] = "n:nopage",
133 [KPF_KSM] = "x:ksm",
134 [KPF_THP] = "t:thp",
135 [KPF_BALLOON] = "o:balloon",
136 [KPF_ZERO_PAGE] = "z:zero_page",
137
138 [KPF_RESERVED] = "r:reserved",
139 [KPF_MLOCKED] = "m:mlocked",
140 [KPF_MAPPEDTODISK] = "d:mappedtodisk",
141 [KPF_PRIVATE] = "P:private",
142 [KPF_PRIVATE_2] = "p:private_2",
143 [KPF_OWNER_PRIVATE] = "O:owner_private",
144 [KPF_ARCH] = "h:arch",
145 [KPF_UNCACHED] = "c:uncached",
146 [KPF_SOFTDIRTY] = "f:softdirty",
147
148 [KPF_READAHEAD] = "I:readahead",
149 [KPF_SLOB_FREE] = "P:slob_free",
150 [KPF_SLUB_FROZEN] = "A:slub_frozen",
151 [KPF_SLUB_DEBUG] = "E:slub_debug",
152 };
153
154
155 static const char * const debugfs_known_mountpoints[] = {
156 "/sys/kernel/debug",
157 "/debug",
158 0,
159 };
160
161 /*
162 * data structures
163 */
164
165 static int opt_raw; /* for kernel developers */
166 static int opt_list; /* list pages (in ranges) */
167 static int opt_no_summary; /* don't show summary */
168 static pid_t opt_pid; /* process to walk */
169 const char * opt_file;
170
171 #define MAX_ADDR_RANGES 1024
172 static int nr_addr_ranges;
173 static unsigned long opt_offset[MAX_ADDR_RANGES];
174 static unsigned long opt_size[MAX_ADDR_RANGES];
175
176 #define MAX_VMAS 10240
177 static int nr_vmas;
178 static unsigned long pg_start[MAX_VMAS];
179 static unsigned long pg_end[MAX_VMAS];
180
181 #define MAX_BIT_FILTERS 64
182 static int nr_bit_filters;
183 static uint64_t opt_mask[MAX_BIT_FILTERS];
184 static uint64_t opt_bits[MAX_BIT_FILTERS];
185
186 static int page_size;
187
188 static int pagemap_fd;
189 static int kpageflags_fd;
190
191 static int opt_hwpoison;
192 static int opt_unpoison;
193
194 static char *hwpoison_debug_fs;
195 static int hwpoison_inject_fd;
196 static int hwpoison_forget_fd;
197
198 #define HASH_SHIFT 13
199 #define HASH_SIZE (1 << HASH_SHIFT)
200 #define HASH_MASK (HASH_SIZE - 1)
201 #define HASH_KEY(flags) (flags & HASH_MASK)
202
203 static unsigned long total_pages;
204 static unsigned long nr_pages[HASH_SIZE];
205 static uint64_t page_flags[HASH_SIZE];
206
207
208 /*
209 * helper functions
210 */
211
212 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
213
214 #define min_t(type, x, y) ({ \
215 type __min1 = (x); \
216 type __min2 = (y); \
217 __min1 < __min2 ? __min1 : __min2; })
218
219 #define max_t(type, x, y) ({ \
220 type __max1 = (x); \
221 type __max2 = (y); \
222 __max1 > __max2 ? __max1 : __max2; })
223
pages2mb(unsigned long pages)224 static unsigned long pages2mb(unsigned long pages)
225 {
226 return (pages * page_size) >> 20;
227 }
228
fatal(const char * x,...)229 static void fatal(const char *x, ...)
230 {
231 va_list ap;
232
233 va_start(ap, x);
234 vfprintf(stderr, x, ap);
235 va_end(ap);
236 exit(EXIT_FAILURE);
237 }
238
checked_open(const char * pathname,int flags)239 static int checked_open(const char *pathname, int flags)
240 {
241 int fd = open(pathname, flags);
242
243 if (fd < 0) {
244 perror(pathname);
245 exit(EXIT_FAILURE);
246 }
247
248 return fd;
249 }
250
251 /*
252 * pagemap/kpageflags routines
253 */
254
do_u64_read(int fd,char * name,uint64_t * buf,unsigned long index,unsigned long count)255 static unsigned long do_u64_read(int fd, char *name,
256 uint64_t *buf,
257 unsigned long index,
258 unsigned long count)
259 {
260 long bytes;
261
262 if (index > ULONG_MAX / 8)
263 fatal("index overflow: %lu\n", index);
264
265 bytes = pread(fd, buf, count * 8, (off_t)index * 8);
266 if (bytes < 0) {
267 perror(name);
268 exit(EXIT_FAILURE);
269 }
270 if (bytes % 8)
271 fatal("partial read: %lu bytes\n", bytes);
272
273 return bytes / 8;
274 }
275
kpageflags_read(uint64_t * buf,unsigned long index,unsigned long pages)276 static unsigned long kpageflags_read(uint64_t *buf,
277 unsigned long index,
278 unsigned long pages)
279 {
280 return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
281 }
282
pagemap_read(uint64_t * buf,unsigned long index,unsigned long pages)283 static unsigned long pagemap_read(uint64_t *buf,
284 unsigned long index,
285 unsigned long pages)
286 {
287 return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
288 }
289
pagemap_pfn(uint64_t val)290 static unsigned long pagemap_pfn(uint64_t val)
291 {
292 unsigned long pfn;
293
294 if (val & PM_PRESENT)
295 pfn = PM_PFRAME(val);
296 else
297 pfn = 0;
298
299 return pfn;
300 }
301
302
303 /*
304 * page flag names
305 */
306
page_flag_name(uint64_t flags)307 static char *page_flag_name(uint64_t flags)
308 {
309 static char buf[65];
310 int present;
311 size_t i, j;
312
313 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
314 present = (flags >> i) & 1;
315 if (!page_flag_names[i]) {
316 if (present)
317 fatal("unknown flag bit %d\n", i);
318 continue;
319 }
320 buf[j++] = present ? page_flag_names[i][0] : '_';
321 }
322
323 return buf;
324 }
325
page_flag_longname(uint64_t flags)326 static char *page_flag_longname(uint64_t flags)
327 {
328 static char buf[1024];
329 size_t i, n;
330
331 for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
332 if (!page_flag_names[i])
333 continue;
334 if ((flags >> i) & 1)
335 n += snprintf(buf + n, sizeof(buf) - n, "%s,",
336 page_flag_names[i] + 2);
337 }
338 if (n)
339 n--;
340 buf[n] = '\0';
341
342 return buf;
343 }
344
345
346 /*
347 * page list and summary
348 */
349
show_page_range(unsigned long voffset,unsigned long offset,unsigned long size,uint64_t flags)350 static void show_page_range(unsigned long voffset, unsigned long offset,
351 unsigned long size, uint64_t flags)
352 {
353 static uint64_t flags0;
354 static unsigned long voff;
355 static unsigned long index;
356 static unsigned long count;
357
358 if (flags == flags0 && offset == index + count &&
359 size && voffset == voff + count) {
360 count += size;
361 return;
362 }
363
364 if (count) {
365 if (opt_pid)
366 printf("%lx\t", voff);
367 if (opt_file)
368 printf("%lu\t", voff);
369 printf("%lx\t%lx\t%s\n",
370 index, count, page_flag_name(flags0));
371 }
372
373 flags0 = flags;
374 index = offset;
375 voff = voffset;
376 count = size;
377 }
378
flush_page_range(void)379 static void flush_page_range(void)
380 {
381 show_page_range(0, 0, 0, 0);
382 }
383
show_page(unsigned long voffset,unsigned long offset,uint64_t flags)384 static void show_page(unsigned long voffset,
385 unsigned long offset, uint64_t flags)
386 {
387 if (opt_pid)
388 printf("%lx\t", voffset);
389 if (opt_file)
390 printf("%lu\t", voffset);
391 printf("%lx\t%s\n", offset, page_flag_name(flags));
392 }
393
show_summary(void)394 static void show_summary(void)
395 {
396 size_t i;
397
398 printf(" flags\tpage-count MB"
399 " symbolic-flags\t\t\tlong-symbolic-flags\n");
400
401 for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
402 if (nr_pages[i])
403 printf("0x%016llx\t%10lu %8lu %s\t%s\n",
404 (unsigned long long)page_flags[i],
405 nr_pages[i],
406 pages2mb(nr_pages[i]),
407 page_flag_name(page_flags[i]),
408 page_flag_longname(page_flags[i]));
409 }
410
411 printf(" total\t%10lu %8lu\n",
412 total_pages, pages2mb(total_pages));
413 }
414
415
416 /*
417 * page flag filters
418 */
419
bit_mask_ok(uint64_t flags)420 static int bit_mask_ok(uint64_t flags)
421 {
422 int i;
423
424 for (i = 0; i < nr_bit_filters; i++) {
425 if (opt_bits[i] == KPF_ALL_BITS) {
426 if ((flags & opt_mask[i]) == 0)
427 return 0;
428 } else {
429 if ((flags & opt_mask[i]) != opt_bits[i])
430 return 0;
431 }
432 }
433
434 return 1;
435 }
436
expand_overloaded_flags(uint64_t flags,uint64_t pme)437 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
438 {
439 /* SLOB/SLUB overload several page flags */
440 if (flags & BIT(SLAB)) {
441 if (flags & BIT(PRIVATE))
442 flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
443 if (flags & BIT(ACTIVE))
444 flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
445 if (flags & BIT(ERROR))
446 flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
447 }
448
449 /* PG_reclaim is overloaded as PG_readahead in the read path */
450 if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
451 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
452
453 if (pme & PM_SOFT_DIRTY)
454 flags |= BIT(SOFTDIRTY);
455
456 return flags;
457 }
458
well_known_flags(uint64_t flags)459 static uint64_t well_known_flags(uint64_t flags)
460 {
461 /* hide flags intended only for kernel hacker */
462 flags &= ~KPF_HACKERS_BITS;
463
464 /* hide non-hugeTLB compound pages */
465 if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
466 flags &= ~BITS_COMPOUND;
467
468 return flags;
469 }
470
kpageflags_flags(uint64_t flags,uint64_t pme)471 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
472 {
473 if (opt_raw)
474 flags = expand_overloaded_flags(flags, pme);
475 else
476 flags = well_known_flags(flags);
477
478 return flags;
479 }
480
481 /*
482 * page actions
483 */
484
prepare_hwpoison_fd(void)485 static void prepare_hwpoison_fd(void)
486 {
487 char buf[MAX_PATH + 1];
488
489 hwpoison_debug_fs = debugfs_mount(NULL);
490 if (!hwpoison_debug_fs) {
491 perror("mount debugfs");
492 exit(EXIT_FAILURE);
493 }
494
495 if (opt_hwpoison && !hwpoison_inject_fd) {
496 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
497 hwpoison_debug_fs);
498 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
499 }
500
501 if (opt_unpoison && !hwpoison_forget_fd) {
502 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
503 hwpoison_debug_fs);
504 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
505 }
506 }
507
hwpoison_page(unsigned long offset)508 static int hwpoison_page(unsigned long offset)
509 {
510 char buf[100];
511 int len;
512
513 len = sprintf(buf, "0x%lx\n", offset);
514 len = write(hwpoison_inject_fd, buf, len);
515 if (len < 0) {
516 perror("hwpoison inject");
517 return len;
518 }
519 return 0;
520 }
521
unpoison_page(unsigned long offset)522 static int unpoison_page(unsigned long offset)
523 {
524 char buf[100];
525 int len;
526
527 len = sprintf(buf, "0x%lx\n", offset);
528 len = write(hwpoison_forget_fd, buf, len);
529 if (len < 0) {
530 perror("hwpoison forget");
531 return len;
532 }
533 return 0;
534 }
535
536 /*
537 * page frame walker
538 */
539
hash_slot(uint64_t flags)540 static size_t hash_slot(uint64_t flags)
541 {
542 size_t k = HASH_KEY(flags);
543 size_t i;
544
545 /* Explicitly reserve slot 0 for flags 0: the following logic
546 * cannot distinguish an unoccupied slot from slot (flags==0).
547 */
548 if (flags == 0)
549 return 0;
550
551 /* search through the remaining (HASH_SIZE-1) slots */
552 for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
553 if (!k || k >= ARRAY_SIZE(page_flags))
554 k = 1;
555 if (page_flags[k] == 0) {
556 page_flags[k] = flags;
557 return k;
558 }
559 if (page_flags[k] == flags)
560 return k;
561 }
562
563 fatal("hash table full: bump up HASH_SHIFT?\n");
564 exit(EXIT_FAILURE);
565 }
566
add_page(unsigned long voffset,unsigned long offset,uint64_t flags,uint64_t pme)567 static void add_page(unsigned long voffset,
568 unsigned long offset, uint64_t flags, uint64_t pme)
569 {
570 flags = kpageflags_flags(flags, pme);
571
572 if (!bit_mask_ok(flags))
573 return;
574
575 if (opt_hwpoison)
576 hwpoison_page(offset);
577 if (opt_unpoison)
578 unpoison_page(offset);
579
580 if (opt_list == 1)
581 show_page_range(voffset, offset, 1, flags);
582 else if (opt_list == 2)
583 show_page(voffset, offset, flags);
584
585 nr_pages[hash_slot(flags)]++;
586 total_pages++;
587 }
588
589 #define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
walk_pfn(unsigned long voffset,unsigned long index,unsigned long count,uint64_t pme)590 static void walk_pfn(unsigned long voffset,
591 unsigned long index,
592 unsigned long count,
593 uint64_t pme)
594 {
595 uint64_t buf[KPAGEFLAGS_BATCH];
596 unsigned long batch;
597 unsigned long pages;
598 unsigned long i;
599
600 while (count) {
601 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
602 pages = kpageflags_read(buf, index, batch);
603 if (pages == 0)
604 break;
605
606 for (i = 0; i < pages; i++)
607 add_page(voffset + i, index + i, buf[i], pme);
608
609 index += pages;
610 count -= pages;
611 }
612 }
613
614 #define PAGEMAP_BATCH (64 << 10)
walk_vma(unsigned long index,unsigned long count)615 static void walk_vma(unsigned long index, unsigned long count)
616 {
617 uint64_t buf[PAGEMAP_BATCH];
618 unsigned long batch;
619 unsigned long pages;
620 unsigned long pfn;
621 unsigned long i;
622
623 while (count) {
624 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
625 pages = pagemap_read(buf, index, batch);
626 if (pages == 0)
627 break;
628
629 for (i = 0; i < pages; i++) {
630 pfn = pagemap_pfn(buf[i]);
631 if (pfn)
632 walk_pfn(index + i, pfn, 1, buf[i]);
633 }
634
635 index += pages;
636 count -= pages;
637 }
638 }
639
walk_task(unsigned long index,unsigned long count)640 static void walk_task(unsigned long index, unsigned long count)
641 {
642 const unsigned long end = index + count;
643 unsigned long start;
644 int i = 0;
645
646 while (index < end) {
647
648 while (pg_end[i] <= index)
649 if (++i >= nr_vmas)
650 return;
651 if (pg_start[i] >= end)
652 return;
653
654 start = max_t(unsigned long, pg_start[i], index);
655 index = min_t(unsigned long, pg_end[i], end);
656
657 assert(start < index);
658 walk_vma(start, index - start);
659 }
660 }
661
add_addr_range(unsigned long offset,unsigned long size)662 static void add_addr_range(unsigned long offset, unsigned long size)
663 {
664 if (nr_addr_ranges >= MAX_ADDR_RANGES)
665 fatal("too many addr ranges\n");
666
667 opt_offset[nr_addr_ranges] = offset;
668 opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
669 nr_addr_ranges++;
670 }
671
walk_addr_ranges(void)672 static void walk_addr_ranges(void)
673 {
674 int i;
675
676 kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
677
678 if (!nr_addr_ranges)
679 add_addr_range(0, ULONG_MAX);
680
681 for (i = 0; i < nr_addr_ranges; i++)
682 if (!opt_pid)
683 walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
684 else
685 walk_task(opt_offset[i], opt_size[i]);
686
687 close(kpageflags_fd);
688 }
689
690
691 /*
692 * user interface
693 */
694
page_flag_type(uint64_t flag)695 static const char *page_flag_type(uint64_t flag)
696 {
697 if (flag & KPF_HACKERS_BITS)
698 return "(r)";
699 if (flag & KPF_OVERLOADED_BITS)
700 return "(o)";
701 return " ";
702 }
703
usage(void)704 static void usage(void)
705 {
706 size_t i, j;
707
708 printf(
709 "page-types [options]\n"
710 " -r|--raw Raw mode, for kernel developers\n"
711 " -d|--describe flags Describe flags\n"
712 " -a|--addr addr-spec Walk a range of pages\n"
713 " -b|--bits bits-spec Walk pages with specified bits\n"
714 " -p|--pid pid Walk process address space\n"
715 " -f|--file filename Walk file address space\n"
716 " -l|--list Show page details in ranges\n"
717 " -L|--list-each Show page details one by one\n"
718 " -N|--no-summary Don't show summary info\n"
719 " -X|--hwpoison hwpoison pages\n"
720 " -x|--unpoison unpoison pages\n"
721 " -h|--help Show this usage message\n"
722 "flags:\n"
723 " 0x10 bitfield format, e.g.\n"
724 " anon bit-name, e.g.\n"
725 " 0x10,anon comma-separated list, e.g.\n"
726 "addr-spec:\n"
727 " N one page at offset N (unit: pages)\n"
728 " N+M pages range from N to N+M-1\n"
729 " N,M pages range from N to M-1\n"
730 " N, pages range from N to end\n"
731 " ,M pages range from 0 to M-1\n"
732 "bits-spec:\n"
733 " bit1,bit2 (flags & (bit1|bit2)) != 0\n"
734 " bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
735 " bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
736 " =bit1,bit2 flags == (bit1|bit2)\n"
737 "bit-names:\n"
738 );
739
740 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
741 if (!page_flag_names[i])
742 continue;
743 printf("%16s%s", page_flag_names[i] + 2,
744 page_flag_type(1ULL << i));
745 if (++j > 3) {
746 j = 0;
747 putchar('\n');
748 }
749 }
750 printf("\n "
751 "(r) raw mode bits (o) overloaded bits\n");
752 }
753
parse_number(const char * str)754 static unsigned long long parse_number(const char *str)
755 {
756 unsigned long long n;
757
758 n = strtoll(str, NULL, 0);
759
760 if (n == 0 && str[0] != '0')
761 fatal("invalid name or number: %s\n", str);
762
763 return n;
764 }
765
parse_pid(const char * str)766 static void parse_pid(const char *str)
767 {
768 FILE *file;
769 char buf[5000];
770
771 opt_pid = parse_number(str);
772
773 sprintf(buf, "/proc/%d/pagemap", opt_pid);
774 pagemap_fd = checked_open(buf, O_RDONLY);
775
776 sprintf(buf, "/proc/%d/maps", opt_pid);
777 file = fopen(buf, "r");
778 if (!file) {
779 perror(buf);
780 exit(EXIT_FAILURE);
781 }
782
783 while (fgets(buf, sizeof(buf), file) != NULL) {
784 unsigned long vm_start;
785 unsigned long vm_end;
786 unsigned long long pgoff;
787 int major, minor;
788 char r, w, x, s;
789 unsigned long ino;
790 int n;
791
792 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
793 &vm_start,
794 &vm_end,
795 &r, &w, &x, &s,
796 &pgoff,
797 &major, &minor,
798 &ino);
799 if (n < 10) {
800 fprintf(stderr, "unexpected line: %s\n", buf);
801 continue;
802 }
803 pg_start[nr_vmas] = vm_start / page_size;
804 pg_end[nr_vmas] = vm_end / page_size;
805 if (++nr_vmas >= MAX_VMAS) {
806 fprintf(stderr, "too many VMAs\n");
807 break;
808 }
809 }
810 fclose(file);
811 }
812
show_file(const char * name,const struct stat * st)813 static void show_file(const char *name, const struct stat *st)
814 {
815 unsigned long long size = st->st_size;
816 char atime[64], mtime[64];
817 long now = time(NULL);
818
819 printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
820 name, (unsigned)st->st_ino,
821 size, (size + page_size - 1) / page_size);
822
823 strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
824 strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
825
826 printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
827 mtime, now - st->st_mtime,
828 atime, now - st->st_atime);
829 }
830
831 static sigjmp_buf sigbus_jmp;
832
833 static void * volatile sigbus_addr;
834
sigbus_handler(int sig,siginfo_t * info,void * ucontex)835 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
836 {
837 (void)sig;
838 (void)ucontex;
839 sigbus_addr = info ? info->si_addr : NULL;
840 siglongjmp(sigbus_jmp, 1);
841 }
842
843 static struct sigaction sigbus_action = {
844 .sa_sigaction = sigbus_handler,
845 .sa_flags = SA_SIGINFO,
846 };
847
walk_file(const char * name,const struct stat * st)848 static void walk_file(const char *name, const struct stat *st)
849 {
850 uint8_t vec[PAGEMAP_BATCH];
851 uint64_t buf[PAGEMAP_BATCH], flags;
852 unsigned long nr_pages, pfn, i;
853 off_t off, end = st->st_size;
854 int fd;
855 ssize_t len;
856 void *ptr;
857 int first = 1;
858
859 fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
860
861 for (off = 0; off < end; off += len) {
862 nr_pages = (end - off + page_size - 1) / page_size;
863 if (nr_pages > PAGEMAP_BATCH)
864 nr_pages = PAGEMAP_BATCH;
865 len = nr_pages * page_size;
866
867 ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
868 if (ptr == MAP_FAILED)
869 fatal("mmap failed: %s", name);
870
871 /* determine cached pages */
872 if (mincore(ptr, len, vec))
873 fatal("mincore failed: %s", name);
874
875 /* turn off readahead */
876 if (madvise(ptr, len, MADV_RANDOM))
877 fatal("madvice failed: %s", name);
878
879 if (sigsetjmp(sigbus_jmp, 1)) {
880 end = off + sigbus_addr ? sigbus_addr - ptr : 0;
881 fprintf(stderr, "got sigbus at offset %lld: %s\n",
882 (long long)end, name);
883 goto got_sigbus;
884 }
885
886 /* populate ptes */
887 for (i = 0; i < nr_pages ; i++) {
888 if (vec[i] & 1)
889 (void)*(volatile int *)(ptr + i * page_size);
890 }
891 got_sigbus:
892
893 /* turn off harvesting reference bits */
894 if (madvise(ptr, len, MADV_SEQUENTIAL))
895 fatal("madvice failed: %s", name);
896
897 if (pagemap_read(buf, (unsigned long)ptr / page_size,
898 nr_pages) != nr_pages)
899 fatal("cannot read pagemap");
900
901 munmap(ptr, len);
902
903 for (i = 0; i < nr_pages; i++) {
904 pfn = pagemap_pfn(buf[i]);
905 if (!pfn)
906 continue;
907 if (!kpageflags_read(&flags, pfn, 1))
908 continue;
909 if (first && opt_list) {
910 first = 0;
911 flush_page_range();
912 show_file(name, st);
913 }
914 add_page(off / page_size + i, pfn, flags, buf[i]);
915 }
916 }
917
918 close(fd);
919 }
920
walk_tree(const char * name,const struct stat * st,int type,struct FTW * f)921 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
922 {
923 (void)f;
924 switch (type) {
925 case FTW_F:
926 if (S_ISREG(st->st_mode))
927 walk_file(name, st);
928 break;
929 case FTW_DNR:
930 fprintf(stderr, "cannot read dir: %s\n", name);
931 break;
932 }
933 return 0;
934 }
935
walk_page_cache(void)936 static void walk_page_cache(void)
937 {
938 struct stat st;
939
940 kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
941 pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
942 sigaction(SIGBUS, &sigbus_action, NULL);
943
944 if (stat(opt_file, &st))
945 fatal("stat failed: %s\n", opt_file);
946
947 if (S_ISREG(st.st_mode)) {
948 walk_file(opt_file, &st);
949 } else if (S_ISDIR(st.st_mode)) {
950 /* do not follow symlinks and mountpoints */
951 if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
952 fatal("nftw failed: %s\n", opt_file);
953 } else
954 fatal("unhandled file type: %s\n", opt_file);
955
956 close(kpageflags_fd);
957 close(pagemap_fd);
958 signal(SIGBUS, SIG_DFL);
959 }
960
parse_file(const char * name)961 static void parse_file(const char *name)
962 {
963 opt_file = name;
964 }
965
parse_addr_range(const char * optarg)966 static void parse_addr_range(const char *optarg)
967 {
968 unsigned long offset;
969 unsigned long size;
970 char *p;
971
972 p = strchr(optarg, ',');
973 if (!p)
974 p = strchr(optarg, '+');
975
976 if (p == optarg) {
977 offset = 0;
978 size = parse_number(p + 1);
979 } else if (p) {
980 offset = parse_number(optarg);
981 if (p[1] == '\0')
982 size = ULONG_MAX;
983 else {
984 size = parse_number(p + 1);
985 if (*p == ',') {
986 if (size < offset)
987 fatal("invalid range: %lu,%lu\n",
988 offset, size);
989 size -= offset;
990 }
991 }
992 } else {
993 offset = parse_number(optarg);
994 size = 1;
995 }
996
997 add_addr_range(offset, size);
998 }
999
add_bits_filter(uint64_t mask,uint64_t bits)1000 static void add_bits_filter(uint64_t mask, uint64_t bits)
1001 {
1002 if (nr_bit_filters >= MAX_BIT_FILTERS)
1003 fatal("too much bit filters\n");
1004
1005 opt_mask[nr_bit_filters] = mask;
1006 opt_bits[nr_bit_filters] = bits;
1007 nr_bit_filters++;
1008 }
1009
parse_flag_name(const char * str,int len)1010 static uint64_t parse_flag_name(const char *str, int len)
1011 {
1012 size_t i;
1013
1014 if (!*str || !len)
1015 return 0;
1016
1017 if (len <= 8 && !strncmp(str, "compound", len))
1018 return BITS_COMPOUND;
1019
1020 for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1021 if (!page_flag_names[i])
1022 continue;
1023 if (!strncmp(str, page_flag_names[i] + 2, len))
1024 return 1ULL << i;
1025 }
1026
1027 return parse_number(str);
1028 }
1029
parse_flag_names(const char * str,int all)1030 static uint64_t parse_flag_names(const char *str, int all)
1031 {
1032 const char *p = str;
1033 uint64_t flags = 0;
1034
1035 while (1) {
1036 if (*p == ',' || *p == '=' || *p == '\0') {
1037 if ((*str != '~') || (*str == '~' && all && *++str))
1038 flags |= parse_flag_name(str, p - str);
1039 if (*p != ',')
1040 break;
1041 str = p + 1;
1042 }
1043 p++;
1044 }
1045
1046 return flags;
1047 }
1048
parse_bits_mask(const char * optarg)1049 static void parse_bits_mask(const char *optarg)
1050 {
1051 uint64_t mask;
1052 uint64_t bits;
1053 const char *p;
1054
1055 p = strchr(optarg, '=');
1056 if (p == optarg) {
1057 mask = KPF_ALL_BITS;
1058 bits = parse_flag_names(p + 1, 0);
1059 } else if (p) {
1060 mask = parse_flag_names(optarg, 0);
1061 bits = parse_flag_names(p + 1, 0);
1062 } else if (strchr(optarg, '~')) {
1063 mask = parse_flag_names(optarg, 1);
1064 bits = parse_flag_names(optarg, 0);
1065 } else {
1066 mask = parse_flag_names(optarg, 0);
1067 bits = KPF_ALL_BITS;
1068 }
1069
1070 add_bits_filter(mask, bits);
1071 }
1072
describe_flags(const char * optarg)1073 static void describe_flags(const char *optarg)
1074 {
1075 uint64_t flags = parse_flag_names(optarg, 0);
1076
1077 printf("0x%016llx\t%s\t%s\n",
1078 (unsigned long long)flags,
1079 page_flag_name(flags),
1080 page_flag_longname(flags));
1081 }
1082
1083 static const struct option opts[] = {
1084 { "raw" , 0, NULL, 'r' },
1085 { "pid" , 1, NULL, 'p' },
1086 { "file" , 1, NULL, 'f' },
1087 { "addr" , 1, NULL, 'a' },
1088 { "bits" , 1, NULL, 'b' },
1089 { "describe" , 1, NULL, 'd' },
1090 { "list" , 0, NULL, 'l' },
1091 { "list-each" , 0, NULL, 'L' },
1092 { "no-summary", 0, NULL, 'N' },
1093 { "hwpoison" , 0, NULL, 'X' },
1094 { "unpoison" , 0, NULL, 'x' },
1095 { "help" , 0, NULL, 'h' },
1096 { NULL , 0, NULL, 0 }
1097 };
1098
main(int argc,char * argv[])1099 int main(int argc, char *argv[])
1100 {
1101 int c;
1102
1103 page_size = getpagesize();
1104
1105 while ((c = getopt_long(argc, argv,
1106 "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1107 switch (c) {
1108 case 'r':
1109 opt_raw = 1;
1110 break;
1111 case 'p':
1112 parse_pid(optarg);
1113 break;
1114 case 'f':
1115 parse_file(optarg);
1116 break;
1117 case 'a':
1118 parse_addr_range(optarg);
1119 break;
1120 case 'b':
1121 parse_bits_mask(optarg);
1122 break;
1123 case 'd':
1124 describe_flags(optarg);
1125 exit(0);
1126 case 'l':
1127 opt_list = 1;
1128 break;
1129 case 'L':
1130 opt_list = 2;
1131 break;
1132 case 'N':
1133 opt_no_summary = 1;
1134 break;
1135 case 'X':
1136 opt_hwpoison = 1;
1137 prepare_hwpoison_fd();
1138 break;
1139 case 'x':
1140 opt_unpoison = 1;
1141 prepare_hwpoison_fd();
1142 break;
1143 case 'h':
1144 usage();
1145 exit(0);
1146 default:
1147 usage();
1148 exit(1);
1149 }
1150 }
1151
1152 if (opt_list && opt_pid)
1153 printf("voffset\t");
1154 if (opt_list && opt_file)
1155 printf("foffset\t");
1156 if (opt_list == 1)
1157 printf("offset\tlen\tflags\n");
1158 if (opt_list == 2)
1159 printf("offset\tflags\n");
1160
1161 if (opt_file)
1162 walk_page_cache();
1163 else
1164 walk_addr_ranges();
1165
1166 if (opt_list == 1)
1167 flush_page_range();
1168
1169 if (opt_no_summary)
1170 return 0;
1171
1172 if (opt_list)
1173 printf("\n\n");
1174
1175 show_summary();
1176
1177 return 0;
1178 }
1179