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