1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * page-types: Tool for querying page flags
4 *
5 * Copyright (C) 2009 Intel corporation
6 *
7 * Authors: Wu Fengguang <fengguang.wu@intel.com>
8 */
9
10 #define _FILE_OFFSET_BITS 64
11 #define _GNU_SOURCE
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <unistd.h>
15 #include <stdint.h>
16 #include <stdarg.h>
17 #include <string.h>
18 #include <getopt.h>
19 #include <limits.h>
20 #include <assert.h>
21 #include <ftw.h>
22 #include <time.h>
23 #include <setjmp.h>
24 #include <signal.h>
25 #include <inttypes.h>
26 #include <sys/types.h>
27 #include <sys/errno.h>
28 #include <sys/fcntl.h>
29 #include <sys/mount.h>
30 #include <sys/statfs.h>
31 #include <sys/mman.h>
32 #include "../../include/uapi/linux/magic.h"
33 #include "../../include/uapi/linux/kernel-page-flags.h"
34 #include <api/fs/fs.h>
35
36 #ifndef MAX_PATH
37 # define MAX_PATH 256
38 #endif
39
40 #ifndef STR
41 # define _STR(x) #x
42 # define STR(x) _STR(x)
43 #endif
44
45 /*
46 * pagemap kernel ABI bits
47 */
48
49 #define PM_ENTRY_BYTES 8
50 #define PM_PFRAME_BITS 55
51 #define PM_PFRAME_MASK ((1LL << PM_PFRAME_BITS) - 1)
52 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
53 #define MAX_SWAPFILES_SHIFT 5
54 #define PM_SWAP_OFFSET(x) (((x) & PM_PFRAME_MASK) >> MAX_SWAPFILES_SHIFT)
55 #define PM_SOFT_DIRTY (1ULL << 55)
56 #define PM_MMAP_EXCLUSIVE (1ULL << 56)
57 #define PM_FILE (1ULL << 61)
58 #define PM_SWAP (1ULL << 62)
59 #define PM_PRESENT (1ULL << 63)
60
61 /*
62 * kernel page flags
63 */
64
65 #define KPF_BYTES 8
66 #define PROC_KPAGEFLAGS "/proc/kpageflags"
67 #define PROC_KPAGECOUNT "/proc/kpagecount"
68 #define PROC_KPAGECGROUP "/proc/kpagecgroup"
69
70 #define SYS_KERNEL_MM_PAGE_IDLE "/sys/kernel/mm/page_idle/bitmap"
71
72 /* [32-] kernel hacking assistances */
73 #define KPF_RESERVED 32
74 #define KPF_MLOCKED 33
75 #define KPF_MAPPEDTODISK 34
76 #define KPF_PRIVATE 35
77 #define KPF_PRIVATE_2 36
78 #define KPF_OWNER_PRIVATE 37
79 #define KPF_ARCH 38
80 #define KPF_UNCACHED 39
81 #define KPF_SOFTDIRTY 40
82 #define KPF_ARCH_2 41
83
84 /* [47-] take some arbitrary free slots for expanding overloaded flags
85 * not part of kernel API
86 */
87 #define KPF_ANON_EXCLUSIVE 47
88 #define KPF_READAHEAD 48
89 #define KPF_SLUB_FROZEN 50
90 #define KPF_SLUB_DEBUG 51
91 #define KPF_FILE 61
92 #define KPF_SWAP 62
93 #define KPF_MMAP_EXCLUSIVE 63
94
95 #define KPF_ALL_BITS ((uint64_t)~0ULL)
96 #define KPF_HACKERS_BITS (0xffffULL << 32)
97 #define KPF_OVERLOADED_BITS (0xffffULL << 48)
98 #define BIT(name) (1ULL << KPF_##name)
99 #define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
100
101 static const char * const page_flag_names[] = {
102 [KPF_LOCKED] = "L:locked",
103 [KPF_ERROR] = "E:error",
104 [KPF_REFERENCED] = "R:referenced",
105 [KPF_UPTODATE] = "U:uptodate",
106 [KPF_DIRTY] = "D:dirty",
107 [KPF_LRU] = "l:lru",
108 [KPF_ACTIVE] = "A:active",
109 [KPF_SLAB] = "S:slab",
110 [KPF_WRITEBACK] = "W:writeback",
111 [KPF_RECLAIM] = "I:reclaim",
112 [KPF_BUDDY] = "B:buddy",
113
114 [KPF_MMAP] = "M:mmap",
115 [KPF_ANON] = "a:anonymous",
116 [KPF_SWAPCACHE] = "s:swapcache",
117 [KPF_SWAPBACKED] = "b:swapbacked",
118 [KPF_COMPOUND_HEAD] = "H:compound_head",
119 [KPF_COMPOUND_TAIL] = "T:compound_tail",
120 [KPF_HUGE] = "G:huge",
121 [KPF_UNEVICTABLE] = "u:unevictable",
122 [KPF_HWPOISON] = "X:hwpoison",
123 [KPF_NOPAGE] = "n:nopage",
124 [KPF_KSM] = "x:ksm",
125 [KPF_THP] = "t:thp",
126 [KPF_OFFLINE] = "o:offline",
127 [KPF_PGTABLE] = "g:pgtable",
128 [KPF_ZERO_PAGE] = "z:zero_page",
129 [KPF_IDLE] = "i:idle_page",
130
131 [KPF_RESERVED] = "r:reserved",
132 [KPF_MLOCKED] = "m:mlocked",
133 [KPF_MAPPEDTODISK] = "d:mappedtodisk",
134 [KPF_PRIVATE] = "P:private",
135 [KPF_PRIVATE_2] = "p:private_2",
136 [KPF_OWNER_PRIVATE] = "O:owner_private",
137 [KPF_ARCH] = "h:arch",
138 [KPF_UNCACHED] = "c:uncached",
139 [KPF_SOFTDIRTY] = "f:softdirty",
140 [KPF_ARCH_2] = "H:arch_2",
141
142 [KPF_ANON_EXCLUSIVE] = "d:anon_exclusive",
143 [KPF_READAHEAD] = "I:readahead",
144 [KPF_SLUB_FROZEN] = "A:slub_frozen",
145 [KPF_SLUB_DEBUG] = "E:slub_debug",
146
147 [KPF_FILE] = "F:file",
148 [KPF_SWAP] = "w:swap",
149 [KPF_MMAP_EXCLUSIVE] = "1:mmap_exclusive",
150 };
151
152
153 /*
154 * data structures
155 */
156
157 static int opt_raw; /* for kernel developers */
158 static int opt_list; /* list pages (in ranges) */
159 static int opt_mark_idle; /* set accessed bit */
160 static int opt_no_summary; /* don't show summary */
161 static pid_t opt_pid; /* process to walk */
162 const char *opt_file; /* file or directory path */
163 static uint64_t opt_cgroup; /* cgroup inode */
164 static int opt_list_cgroup;/* list page cgroup */
165 static int opt_list_mapcnt;/* list page map count */
166 static const char *opt_kpageflags;/* kpageflags file to parse */
167
168 #define MAX_ADDR_RANGES 1024
169 static int nr_addr_ranges;
170 static unsigned long opt_offset[MAX_ADDR_RANGES];
171 static unsigned long opt_size[MAX_ADDR_RANGES];
172
173 #define MAX_VMAS 10240
174 static int nr_vmas;
175 static unsigned long pg_start[MAX_VMAS];
176 static unsigned long pg_end[MAX_VMAS];
177
178 #define MAX_BIT_FILTERS 64
179 static int nr_bit_filters;
180 static uint64_t opt_mask[MAX_BIT_FILTERS];
181 static uint64_t opt_bits[MAX_BIT_FILTERS];
182
183 static int page_size;
184
185 static int pagemap_fd;
186 static int kpageflags_fd;
187 static int kpagecount_fd = -1;
188 static int kpagecgroup_fd = -1;
189 static int page_idle_fd = -1;
190
191 static int opt_hwpoison;
192 static int opt_unpoison;
193
194 static const 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,const char * name,uint64_t * buf,unsigned long index,unsigned long count)255 static unsigned long do_u64_read(int fd, const 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, opt_kpageflags, buf, index, pages);
281 }
282
kpagecgroup_read(uint64_t * buf,unsigned long index,unsigned long pages)283 static unsigned long kpagecgroup_read(uint64_t *buf,
284 unsigned long index,
285 unsigned long pages)
286 {
287 if (kpagecgroup_fd < 0)
288 return pages;
289
290 return do_u64_read(kpagecgroup_fd, opt_kpageflags, buf, index, pages);
291 }
292
kpagecount_read(uint64_t * buf,unsigned long index,unsigned long pages)293 static unsigned long kpagecount_read(uint64_t *buf,
294 unsigned long index,
295 unsigned long pages)
296 {
297 return kpagecount_fd < 0 ? pages :
298 do_u64_read(kpagecount_fd, PROC_KPAGECOUNT,
299 buf, index, pages);
300 }
301
pagemap_read(uint64_t * buf,unsigned long index,unsigned long pages)302 static unsigned long pagemap_read(uint64_t *buf,
303 unsigned long index,
304 unsigned long pages)
305 {
306 return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
307 }
308
pagemap_pfn(uint64_t val)309 static unsigned long pagemap_pfn(uint64_t val)
310 {
311 unsigned long pfn;
312
313 if (val & PM_PRESENT)
314 pfn = PM_PFRAME(val);
315 else
316 pfn = 0;
317
318 return pfn;
319 }
320
pagemap_swap_offset(uint64_t val)321 static unsigned long pagemap_swap_offset(uint64_t val)
322 {
323 return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
324 }
325
326 /*
327 * page flag names
328 */
329
page_flag_name(uint64_t flags)330 static char *page_flag_name(uint64_t flags)
331 {
332 static char buf[65];
333 int present;
334 size_t i, j;
335
336 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
337 present = (flags >> i) & 1;
338 if (!page_flag_names[i]) {
339 if (present)
340 fatal("unknown flag bit %d\n", i);
341 continue;
342 }
343 buf[j++] = present ? page_flag_names[i][0] : '_';
344 }
345
346 return buf;
347 }
348
page_flag_longname(uint64_t flags)349 static char *page_flag_longname(uint64_t flags)
350 {
351 static char buf[1024];
352 size_t i, n;
353
354 for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
355 if (!page_flag_names[i])
356 continue;
357 if ((flags >> i) & 1)
358 n += snprintf(buf + n, sizeof(buf) - n, "%s,",
359 page_flag_names[i] + 2);
360 }
361 if (n)
362 n--;
363 buf[n] = '\0';
364
365 return buf;
366 }
367
368
369 /*
370 * page list and summary
371 */
372
show_page_range(unsigned long voffset,unsigned long offset,unsigned long size,uint64_t flags,uint64_t cgroup,uint64_t mapcnt)373 static void show_page_range(unsigned long voffset, unsigned long offset,
374 unsigned long size, uint64_t flags,
375 uint64_t cgroup, uint64_t mapcnt)
376 {
377 static uint64_t flags0;
378 static uint64_t cgroup0;
379 static uint64_t mapcnt0;
380 static unsigned long voff;
381 static unsigned long index;
382 static unsigned long count;
383
384 if (flags == flags0 && cgroup == cgroup0 && mapcnt == mapcnt0 &&
385 offset == index + count && size && voffset == voff + count) {
386 count += size;
387 return;
388 }
389
390 if (count) {
391 if (opt_pid)
392 printf("%lx\t", voff);
393 if (opt_file)
394 printf("%lx\t", voff);
395 if (opt_list_cgroup)
396 printf("@%" PRIu64 "\t", cgroup0);
397 if (opt_list_mapcnt)
398 printf("%" PRIu64 "\t", mapcnt0);
399 printf("%lx\t%lx\t%s\n",
400 index, count, page_flag_name(flags0));
401 }
402
403 flags0 = flags;
404 cgroup0 = cgroup;
405 mapcnt0 = mapcnt;
406 index = offset;
407 voff = voffset;
408 count = size;
409 }
410
flush_page_range(void)411 static void flush_page_range(void)
412 {
413 show_page_range(0, 0, 0, 0, 0, 0);
414 }
415
show_page(unsigned long voffset,unsigned long offset,uint64_t flags,uint64_t cgroup,uint64_t mapcnt)416 static void show_page(unsigned long voffset, unsigned long offset,
417 uint64_t flags, uint64_t cgroup, uint64_t mapcnt)
418 {
419 if (opt_pid)
420 printf("%lx\t", voffset);
421 if (opt_file)
422 printf("%lx\t", voffset);
423 if (opt_list_cgroup)
424 printf("@%" PRIu64 "\t", cgroup);
425 if (opt_list_mapcnt)
426 printf("%" PRIu64 "\t", mapcnt);
427
428 printf("%lx\t%s\n", offset, page_flag_name(flags));
429 }
430
show_summary(void)431 static void show_summary(void)
432 {
433 size_t i;
434
435 printf(" flags\tpage-count MB"
436 " symbolic-flags\t\t\tlong-symbolic-flags\n");
437
438 for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
439 if (nr_pages[i])
440 printf("0x%016llx\t%10lu %8lu %s\t%s\n",
441 (unsigned long long)page_flags[i],
442 nr_pages[i],
443 pages2mb(nr_pages[i]),
444 page_flag_name(page_flags[i]),
445 page_flag_longname(page_flags[i]));
446 }
447
448 printf(" total\t%10lu %8lu\n",
449 total_pages, pages2mb(total_pages));
450 }
451
452
453 /*
454 * page flag filters
455 */
456
bit_mask_ok(uint64_t flags)457 static int bit_mask_ok(uint64_t flags)
458 {
459 int i;
460
461 for (i = 0; i < nr_bit_filters; i++) {
462 if (opt_bits[i] == KPF_ALL_BITS) {
463 if ((flags & opt_mask[i]) == 0)
464 return 0;
465 } else {
466 if ((flags & opt_mask[i]) != opt_bits[i])
467 return 0;
468 }
469 }
470
471 return 1;
472 }
473
expand_overloaded_flags(uint64_t flags,uint64_t pme)474 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
475 {
476 /* Anonymous pages overload PG_mappedtodisk */
477 if ((flags & BIT(ANON)) && (flags & BIT(MAPPEDTODISK)))
478 flags ^= BIT(MAPPEDTODISK) | BIT(ANON_EXCLUSIVE);
479
480 /* SLUB overloads several page flags */
481 if (flags & BIT(SLAB)) {
482 if (flags & BIT(ACTIVE))
483 flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
484 if (flags & BIT(ERROR))
485 flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
486 }
487
488 /* PG_reclaim is overloaded as PG_readahead in the read path */
489 if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
490 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
491
492 if (pme & PM_SOFT_DIRTY)
493 flags |= BIT(SOFTDIRTY);
494 if (pme & PM_FILE)
495 flags |= BIT(FILE);
496 if (pme & PM_SWAP)
497 flags |= BIT(SWAP);
498 if (pme & PM_MMAP_EXCLUSIVE)
499 flags |= BIT(MMAP_EXCLUSIVE);
500
501 return flags;
502 }
503
well_known_flags(uint64_t flags)504 static uint64_t well_known_flags(uint64_t flags)
505 {
506 /* hide flags intended only for kernel hacker */
507 flags &= ~KPF_HACKERS_BITS;
508
509 /* hide non-hugeTLB compound pages */
510 if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
511 flags &= ~BITS_COMPOUND;
512
513 return flags;
514 }
515
kpageflags_flags(uint64_t flags,uint64_t pme)516 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
517 {
518 if (opt_raw)
519 flags = expand_overloaded_flags(flags, pme);
520 else
521 flags = well_known_flags(flags);
522
523 return flags;
524 }
525
526 /*
527 * page actions
528 */
529
prepare_hwpoison_fd(void)530 static void prepare_hwpoison_fd(void)
531 {
532 char buf[MAX_PATH + 1];
533
534 hwpoison_debug_fs = debugfs__mount();
535 if (!hwpoison_debug_fs) {
536 perror("mount debugfs");
537 exit(EXIT_FAILURE);
538 }
539
540 if (opt_hwpoison && !hwpoison_inject_fd) {
541 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
542 hwpoison_debug_fs);
543 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
544 }
545
546 if (opt_unpoison && !hwpoison_forget_fd) {
547 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
548 hwpoison_debug_fs);
549 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
550 }
551 }
552
hwpoison_page(unsigned long offset)553 static int hwpoison_page(unsigned long offset)
554 {
555 char buf[100];
556 int len;
557
558 len = sprintf(buf, "0x%lx\n", offset);
559 len = write(hwpoison_inject_fd, buf, len);
560 if (len < 0) {
561 perror("hwpoison inject");
562 return len;
563 }
564 return 0;
565 }
566
unpoison_page(unsigned long offset)567 static int unpoison_page(unsigned long offset)
568 {
569 char buf[100];
570 int len;
571
572 len = sprintf(buf, "0x%lx\n", offset);
573 len = write(hwpoison_forget_fd, buf, len);
574 if (len < 0) {
575 perror("hwpoison forget");
576 return len;
577 }
578 return 0;
579 }
580
mark_page_idle(unsigned long offset)581 static int mark_page_idle(unsigned long offset)
582 {
583 static unsigned long off;
584 static uint64_t buf;
585 int len;
586
587 if ((offset / 64 == off / 64) || buf == 0) {
588 buf |= 1UL << (offset % 64);
589 off = offset;
590 return 0;
591 }
592
593 len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
594 if (len < 0) {
595 perror("mark page idle");
596 return len;
597 }
598
599 buf = 1UL << (offset % 64);
600 off = offset;
601
602 return 0;
603 }
604
605 /*
606 * page frame walker
607 */
608
hash_slot(uint64_t flags)609 static size_t hash_slot(uint64_t flags)
610 {
611 size_t k = HASH_KEY(flags);
612 size_t i;
613
614 /* Explicitly reserve slot 0 for flags 0: the following logic
615 * cannot distinguish an unoccupied slot from slot (flags==0).
616 */
617 if (flags == 0)
618 return 0;
619
620 /* search through the remaining (HASH_SIZE-1) slots */
621 for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
622 if (!k || k >= ARRAY_SIZE(page_flags))
623 k = 1;
624 if (page_flags[k] == 0) {
625 page_flags[k] = flags;
626 return k;
627 }
628 if (page_flags[k] == flags)
629 return k;
630 }
631
632 fatal("hash table full: bump up HASH_SHIFT?\n");
633 exit(EXIT_FAILURE);
634 }
635
add_page(unsigned long voffset,unsigned long offset,uint64_t flags,uint64_t cgroup,uint64_t mapcnt,uint64_t pme)636 static void add_page(unsigned long voffset, unsigned long offset,
637 uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
638 uint64_t pme)
639 {
640 flags = kpageflags_flags(flags, pme);
641
642 if (!bit_mask_ok(flags))
643 return;
644
645 if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
646 return;
647
648 if (opt_hwpoison)
649 hwpoison_page(offset);
650 if (opt_unpoison)
651 unpoison_page(offset);
652
653 if (opt_mark_idle)
654 mark_page_idle(offset);
655
656 if (opt_list == 1)
657 show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
658 else if (opt_list == 2)
659 show_page(voffset, offset, flags, cgroup, mapcnt);
660
661 nr_pages[hash_slot(flags)]++;
662 total_pages++;
663 }
664
665 #define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
walk_pfn(unsigned long voffset,unsigned long index,unsigned long count,uint64_t pme)666 static void walk_pfn(unsigned long voffset,
667 unsigned long index,
668 unsigned long count,
669 uint64_t pme)
670 {
671 uint64_t buf[KPAGEFLAGS_BATCH];
672 uint64_t cgi[KPAGEFLAGS_BATCH];
673 uint64_t cnt[KPAGEFLAGS_BATCH];
674 unsigned long batch;
675 unsigned long pages;
676 unsigned long i;
677
678 /*
679 * kpagecgroup_read() reads only if kpagecgroup were opened, but
680 * /proc/kpagecgroup might even not exist, so it's better to fill
681 * them with zeros here.
682 */
683 if (count == 1)
684 cgi[0] = 0;
685 else
686 memset(cgi, 0, sizeof cgi);
687
688 while (count) {
689 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
690 pages = kpageflags_read(buf, index, batch);
691 if (pages == 0)
692 break;
693
694 if (kpagecgroup_read(cgi, index, pages) != pages)
695 fatal("kpagecgroup returned fewer pages than expected");
696
697 if (kpagecount_read(cnt, index, pages) != pages)
698 fatal("kpagecount returned fewer pages than expected");
699
700 for (i = 0; i < pages; i++)
701 add_page(voffset + i, index + i,
702 buf[i], cgi[i], cnt[i], pme);
703
704 index += pages;
705 count -= pages;
706 }
707 }
708
walk_swap(unsigned long voffset,uint64_t pme)709 static void walk_swap(unsigned long voffset, uint64_t pme)
710 {
711 uint64_t flags = kpageflags_flags(0, pme);
712
713 if (!bit_mask_ok(flags))
714 return;
715
716 if (opt_cgroup)
717 return;
718
719 if (opt_list == 1)
720 show_page_range(voffset, pagemap_swap_offset(pme),
721 1, flags, 0, 0);
722 else if (opt_list == 2)
723 show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
724
725 nr_pages[hash_slot(flags)]++;
726 total_pages++;
727 }
728
729 #define PAGEMAP_BATCH (64 << 10)
walk_vma(unsigned long index,unsigned long count)730 static void walk_vma(unsigned long index, unsigned long count)
731 {
732 uint64_t buf[PAGEMAP_BATCH];
733 unsigned long batch;
734 unsigned long pages;
735 unsigned long pfn;
736 unsigned long i;
737
738 while (count) {
739 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
740 pages = pagemap_read(buf, index, batch);
741 if (pages == 0)
742 break;
743
744 for (i = 0; i < pages; i++) {
745 pfn = pagemap_pfn(buf[i]);
746 if (pfn)
747 walk_pfn(index + i, pfn, 1, buf[i]);
748 if (buf[i] & PM_SWAP)
749 walk_swap(index + i, buf[i]);
750 }
751
752 index += pages;
753 count -= pages;
754 }
755 }
756
walk_task(unsigned long index,unsigned long count)757 static void walk_task(unsigned long index, unsigned long count)
758 {
759 const unsigned long end = index + count;
760 unsigned long start;
761 int i = 0;
762
763 while (index < end) {
764
765 while (pg_end[i] <= index)
766 if (++i >= nr_vmas)
767 return;
768 if (pg_start[i] >= end)
769 return;
770
771 start = max_t(unsigned long, pg_start[i], index);
772 index = min_t(unsigned long, pg_end[i], end);
773
774 assert(start < index);
775 walk_vma(start, index - start);
776 }
777 }
778
add_addr_range(unsigned long offset,unsigned long size)779 static void add_addr_range(unsigned long offset, unsigned long size)
780 {
781 if (nr_addr_ranges >= MAX_ADDR_RANGES)
782 fatal("too many addr ranges\n");
783
784 opt_offset[nr_addr_ranges] = offset;
785 opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
786 nr_addr_ranges++;
787 }
788
walk_addr_ranges(void)789 static void walk_addr_ranges(void)
790 {
791 int i;
792
793 kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
794
795 if (!nr_addr_ranges)
796 add_addr_range(0, ULONG_MAX);
797
798 for (i = 0; i < nr_addr_ranges; i++)
799 if (!opt_pid)
800 walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
801 else
802 walk_task(opt_offset[i], opt_size[i]);
803
804 if (opt_mark_idle)
805 mark_page_idle(0);
806
807 close(kpageflags_fd);
808 }
809
810
811 /*
812 * user interface
813 */
814
page_flag_type(uint64_t flag)815 static const char *page_flag_type(uint64_t flag)
816 {
817 if (flag & KPF_HACKERS_BITS)
818 return "(r)";
819 if (flag & KPF_OVERLOADED_BITS)
820 return "(o)";
821 return " ";
822 }
823
usage(void)824 static void usage(void)
825 {
826 size_t i, j;
827
828 printf(
829 "page-types [options]\n"
830 " -r|--raw Raw mode, for kernel developers\n"
831 " -d|--describe flags Describe flags\n"
832 " -a|--addr addr-spec Walk a range of pages\n"
833 " -b|--bits bits-spec Walk pages with specified bits\n"
834 " -c|--cgroup path|@inode Walk pages within memory cgroup\n"
835 " -p|--pid pid Walk process address space\n"
836 " -f|--file filename Walk file address space\n"
837 " -i|--mark-idle Mark pages idle\n"
838 " -l|--list Show page details in ranges\n"
839 " -L|--list-each Show page details one by one\n"
840 " -C|--list-cgroup Show cgroup inode for pages\n"
841 " -M|--list-mapcnt Show page map count\n"
842 " -N|--no-summary Don't show summary info\n"
843 " -X|--hwpoison hwpoison pages\n"
844 " -x|--unpoison unpoison pages\n"
845 " -F|--kpageflags filename kpageflags file to parse\n"
846 " -h|--help Show this usage message\n"
847 "flags:\n"
848 " 0x10 bitfield format, e.g.\n"
849 " anon bit-name, e.g.\n"
850 " 0x10,anon comma-separated list, e.g.\n"
851 "addr-spec:\n"
852 " N one page at offset N (unit: pages)\n"
853 " N+M pages range from N to N+M-1\n"
854 " N,M pages range from N to M-1\n"
855 " N, pages range from N to end\n"
856 " ,M pages range from 0 to M-1\n"
857 "bits-spec:\n"
858 " bit1,bit2 (flags & (bit1|bit2)) != 0\n"
859 " bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
860 " bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
861 " =bit1,bit2 flags == (bit1|bit2)\n"
862 "bit-names:\n"
863 );
864
865 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
866 if (!page_flag_names[i])
867 continue;
868 printf("%16s%s", page_flag_names[i] + 2,
869 page_flag_type(1ULL << i));
870 if (++j > 3) {
871 j = 0;
872 putchar('\n');
873 }
874 }
875 printf("\n "
876 "(r) raw mode bits (o) overloaded bits\n");
877 }
878
parse_number(const char * str)879 static unsigned long long parse_number(const char *str)
880 {
881 unsigned long long n;
882
883 n = strtoll(str, NULL, 0);
884
885 if (n == 0 && str[0] != '0')
886 fatal("invalid name or number: %s\n", str);
887
888 return n;
889 }
890
parse_pid(const char * str)891 static void parse_pid(const char *str)
892 {
893 FILE *file;
894 char buf[5000];
895
896 opt_pid = parse_number(str);
897
898 sprintf(buf, "/proc/%d/pagemap", opt_pid);
899 pagemap_fd = checked_open(buf, O_RDONLY);
900
901 sprintf(buf, "/proc/%d/maps", opt_pid);
902 file = fopen(buf, "r");
903 if (!file) {
904 perror(buf);
905 exit(EXIT_FAILURE);
906 }
907
908 while (fgets(buf, sizeof(buf), file) != NULL) {
909 unsigned long vm_start;
910 unsigned long vm_end;
911 unsigned long long pgoff;
912 int major, minor;
913 char r, w, x, s;
914 unsigned long ino;
915 int n;
916
917 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
918 &vm_start,
919 &vm_end,
920 &r, &w, &x, &s,
921 &pgoff,
922 &major, &minor,
923 &ino);
924 if (n < 10) {
925 fprintf(stderr, "unexpected line: %s\n", buf);
926 continue;
927 }
928 pg_start[nr_vmas] = vm_start / page_size;
929 pg_end[nr_vmas] = vm_end / page_size;
930 if (++nr_vmas >= MAX_VMAS) {
931 fprintf(stderr, "too many VMAs\n");
932 break;
933 }
934 }
935 fclose(file);
936 }
937
show_file(const char * name,const struct stat * st)938 static void show_file(const char *name, const struct stat *st)
939 {
940 unsigned long long size = st->st_size;
941 char atime[64], mtime[64];
942 long now = time(NULL);
943
944 printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
945 name, (unsigned)st->st_ino,
946 size, (size + page_size - 1) / page_size);
947
948 strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
949 strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
950
951 printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
952 mtime, now - st->st_mtime,
953 atime, now - st->st_atime);
954 }
955
956 static sigjmp_buf sigbus_jmp;
957
958 static void * volatile sigbus_addr;
959
sigbus_handler(int sig,siginfo_t * info,void * ucontex)960 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
961 {
962 (void)sig;
963 (void)ucontex;
964 sigbus_addr = info ? info->si_addr : NULL;
965 siglongjmp(sigbus_jmp, 1);
966 }
967
968 static struct sigaction sigbus_action = {
969 .sa_sigaction = sigbus_handler,
970 .sa_flags = SA_SIGINFO,
971 };
972
walk_file_range(const char * name,int fd,unsigned long off,unsigned long end)973 static void walk_file_range(const char *name, int fd,
974 unsigned long off, unsigned long end)
975 {
976 uint8_t vec[PAGEMAP_BATCH];
977 uint64_t buf[PAGEMAP_BATCH], flags;
978 uint64_t cgroup = 0;
979 uint64_t mapcnt = 0;
980 unsigned long nr_pages, pfn, i;
981 ssize_t len;
982 void *ptr;
983 int first = 1;
984
985 for (; off < end; off += len) {
986 nr_pages = (end - off + page_size - 1) / page_size;
987 if (nr_pages > PAGEMAP_BATCH)
988 nr_pages = PAGEMAP_BATCH;
989 len = nr_pages * page_size;
990
991 ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
992 if (ptr == MAP_FAILED)
993 fatal("mmap failed: %s", name);
994
995 /* determine cached pages */
996 if (mincore(ptr, len, vec))
997 fatal("mincore failed: %s", name);
998
999 /* turn off readahead */
1000 if (madvise(ptr, len, MADV_RANDOM))
1001 fatal("madvice failed: %s", name);
1002
1003 if (sigsetjmp(sigbus_jmp, 1)) {
1004 end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1005 fprintf(stderr, "got sigbus at offset %lld: %s\n",
1006 (long long)end, name);
1007 goto got_sigbus;
1008 }
1009
1010 /* populate ptes */
1011 for (i = 0; i < nr_pages ; i++) {
1012 if (vec[i] & 1)
1013 (void)*(volatile int *)(ptr + i * page_size);
1014 }
1015 got_sigbus:
1016
1017 /* turn off harvesting reference bits */
1018 if (madvise(ptr, len, MADV_SEQUENTIAL))
1019 fatal("madvice failed: %s", name);
1020
1021 if (pagemap_read(buf, (unsigned long)ptr / page_size,
1022 nr_pages) != nr_pages)
1023 fatal("cannot read pagemap");
1024
1025 munmap(ptr, len);
1026
1027 for (i = 0; i < nr_pages; i++) {
1028 pfn = pagemap_pfn(buf[i]);
1029 if (!pfn)
1030 continue;
1031 if (!kpageflags_read(&flags, pfn, 1))
1032 continue;
1033 if (!kpagecgroup_read(&cgroup, pfn, 1))
1034 fatal("kpagecgroup_read failed");
1035 if (!kpagecount_read(&mapcnt, pfn, 1))
1036 fatal("kpagecount_read failed");
1037 if (first && opt_list) {
1038 first = 0;
1039 flush_page_range();
1040 }
1041 add_page(off / page_size + i, pfn,
1042 flags, cgroup, mapcnt, buf[i]);
1043 }
1044 }
1045 }
1046
walk_file(const char * name,const struct stat * st)1047 static void walk_file(const char *name, const struct stat *st)
1048 {
1049 int i;
1050 int fd;
1051
1052 fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
1053
1054 if (!nr_addr_ranges)
1055 add_addr_range(0, st->st_size / page_size);
1056
1057 for (i = 0; i < nr_addr_ranges; i++)
1058 walk_file_range(name, fd, opt_offset[i] * page_size,
1059 (opt_offset[i] + opt_size[i]) * page_size);
1060
1061 close(fd);
1062 }
1063
walk_tree(const char * name,const struct stat * st,int type,struct FTW * f)1064 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1065 {
1066 (void)f;
1067 switch (type) {
1068 case FTW_F:
1069 if (S_ISREG(st->st_mode))
1070 walk_file(name, st);
1071 break;
1072 case FTW_DNR:
1073 fprintf(stderr, "cannot read dir: %s\n", name);
1074 break;
1075 }
1076 return 0;
1077 }
1078
1079 struct stat st;
1080
walk_page_cache(void)1081 static void walk_page_cache(void)
1082 {
1083 kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1084 pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1085 sigaction(SIGBUS, &sigbus_action, NULL);
1086
1087 if (stat(opt_file, &st))
1088 fatal("stat failed: %s\n", opt_file);
1089
1090 if (S_ISREG(st.st_mode)) {
1091 walk_file(opt_file, &st);
1092 } else if (S_ISDIR(st.st_mode)) {
1093 /* do not follow symlinks and mountpoints */
1094 if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1095 fatal("nftw failed: %s\n", opt_file);
1096 } else
1097 fatal("unhandled file type: %s\n", opt_file);
1098
1099 close(kpageflags_fd);
1100 close(pagemap_fd);
1101 signal(SIGBUS, SIG_DFL);
1102 }
1103
parse_file(const char * name)1104 static void parse_file(const char *name)
1105 {
1106 opt_file = name;
1107 }
1108
parse_cgroup(const char * path)1109 static void parse_cgroup(const char *path)
1110 {
1111 if (path[0] == '@') {
1112 opt_cgroup = parse_number(path + 1);
1113 return;
1114 }
1115
1116 struct stat st;
1117
1118 if (stat(path, &st))
1119 fatal("stat failed: %s: %m\n", path);
1120
1121 if (!S_ISDIR(st.st_mode))
1122 fatal("cgroup supposed to be a directory: %s\n", path);
1123
1124 opt_cgroup = st.st_ino;
1125 }
1126
parse_addr_range(const char * optarg)1127 static void parse_addr_range(const char *optarg)
1128 {
1129 unsigned long offset;
1130 unsigned long size;
1131 char *p;
1132
1133 p = strchr(optarg, ',');
1134 if (!p)
1135 p = strchr(optarg, '+');
1136
1137 if (p == optarg) {
1138 offset = 0;
1139 size = parse_number(p + 1);
1140 } else if (p) {
1141 offset = parse_number(optarg);
1142 if (p[1] == '\0')
1143 size = ULONG_MAX;
1144 else {
1145 size = parse_number(p + 1);
1146 if (*p == ',') {
1147 if (size < offset)
1148 fatal("invalid range: %lu,%lu\n",
1149 offset, size);
1150 size -= offset;
1151 }
1152 }
1153 } else {
1154 offset = parse_number(optarg);
1155 size = 1;
1156 }
1157
1158 add_addr_range(offset, size);
1159 }
1160
add_bits_filter(uint64_t mask,uint64_t bits)1161 static void add_bits_filter(uint64_t mask, uint64_t bits)
1162 {
1163 if (nr_bit_filters >= MAX_BIT_FILTERS)
1164 fatal("too much bit filters\n");
1165
1166 opt_mask[nr_bit_filters] = mask;
1167 opt_bits[nr_bit_filters] = bits;
1168 nr_bit_filters++;
1169 }
1170
parse_flag_name(const char * str,int len)1171 static uint64_t parse_flag_name(const char *str, int len)
1172 {
1173 size_t i;
1174
1175 if (!*str || !len)
1176 return 0;
1177
1178 if (len <= 8 && !strncmp(str, "compound", len))
1179 return BITS_COMPOUND;
1180
1181 for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1182 if (!page_flag_names[i])
1183 continue;
1184 if (!strncmp(str, page_flag_names[i] + 2, len))
1185 return 1ULL << i;
1186 }
1187
1188 return parse_number(str);
1189 }
1190
parse_flag_names(const char * str,int all)1191 static uint64_t parse_flag_names(const char *str, int all)
1192 {
1193 const char *p = str;
1194 uint64_t flags = 0;
1195
1196 while (1) {
1197 if (*p == ',' || *p == '=' || *p == '\0') {
1198 if ((*str != '~') || (*str == '~' && all && *++str))
1199 flags |= parse_flag_name(str, p - str);
1200 if (*p != ',')
1201 break;
1202 str = p + 1;
1203 }
1204 p++;
1205 }
1206
1207 return flags;
1208 }
1209
parse_bits_mask(const char * optarg)1210 static void parse_bits_mask(const char *optarg)
1211 {
1212 uint64_t mask;
1213 uint64_t bits;
1214 const char *p;
1215
1216 p = strchr(optarg, '=');
1217 if (p == optarg) {
1218 mask = KPF_ALL_BITS;
1219 bits = parse_flag_names(p + 1, 0);
1220 } else if (p) {
1221 mask = parse_flag_names(optarg, 0);
1222 bits = parse_flag_names(p + 1, 0);
1223 } else if (strchr(optarg, '~')) {
1224 mask = parse_flag_names(optarg, 1);
1225 bits = parse_flag_names(optarg, 0);
1226 } else {
1227 mask = parse_flag_names(optarg, 0);
1228 bits = KPF_ALL_BITS;
1229 }
1230
1231 add_bits_filter(mask, bits);
1232 }
1233
parse_kpageflags(const char * name)1234 static void parse_kpageflags(const char *name)
1235 {
1236 opt_kpageflags = name;
1237 }
1238
describe_flags(const char * optarg)1239 static void describe_flags(const char *optarg)
1240 {
1241 uint64_t flags = parse_flag_names(optarg, 0);
1242
1243 printf("0x%016llx\t%s\t%s\n",
1244 (unsigned long long)flags,
1245 page_flag_name(flags),
1246 page_flag_longname(flags));
1247 }
1248
1249 static const struct option opts[] = {
1250 { "raw" , 0, NULL, 'r' },
1251 { "pid" , 1, NULL, 'p' },
1252 { "file" , 1, NULL, 'f' },
1253 { "addr" , 1, NULL, 'a' },
1254 { "bits" , 1, NULL, 'b' },
1255 { "cgroup" , 1, NULL, 'c' },
1256 { "describe" , 1, NULL, 'd' },
1257 { "mark-idle" , 0, NULL, 'i' },
1258 { "list" , 0, NULL, 'l' },
1259 { "list-each" , 0, NULL, 'L' },
1260 { "list-cgroup", 0, NULL, 'C' },
1261 { "list-mapcnt", 0, NULL, 'M' },
1262 { "no-summary", 0, NULL, 'N' },
1263 { "hwpoison" , 0, NULL, 'X' },
1264 { "unpoison" , 0, NULL, 'x' },
1265 { "kpageflags", 0, NULL, 'F' },
1266 { "help" , 0, NULL, 'h' },
1267 { NULL , 0, NULL, 0 }
1268 };
1269
main(int argc,char * argv[])1270 int main(int argc, char *argv[])
1271 {
1272 int c;
1273
1274 page_size = getpagesize();
1275
1276 while ((c = getopt_long(argc, argv,
1277 "rp:f:a:b:d:c:CilLMNXxF:h",
1278 opts, NULL)) != -1) {
1279 switch (c) {
1280 case 'r':
1281 opt_raw = 1;
1282 break;
1283 case 'p':
1284 parse_pid(optarg);
1285 break;
1286 case 'f':
1287 parse_file(optarg);
1288 break;
1289 case 'a':
1290 parse_addr_range(optarg);
1291 break;
1292 case 'b':
1293 parse_bits_mask(optarg);
1294 break;
1295 case 'c':
1296 parse_cgroup(optarg);
1297 break;
1298 case 'C':
1299 opt_list_cgroup = 1;
1300 break;
1301 case 'd':
1302 describe_flags(optarg);
1303 exit(0);
1304 case 'i':
1305 opt_mark_idle = 1;
1306 break;
1307 case 'l':
1308 opt_list = 1;
1309 break;
1310 case 'L':
1311 opt_list = 2;
1312 break;
1313 case 'M':
1314 opt_list_mapcnt = 1;
1315 break;
1316 case 'N':
1317 opt_no_summary = 1;
1318 break;
1319 case 'X':
1320 opt_hwpoison = 1;
1321 prepare_hwpoison_fd();
1322 break;
1323 case 'x':
1324 opt_unpoison = 1;
1325 prepare_hwpoison_fd();
1326 break;
1327 case 'F':
1328 parse_kpageflags(optarg);
1329 break;
1330 case 'h':
1331 usage();
1332 exit(0);
1333 default:
1334 usage();
1335 exit(1);
1336 }
1337 }
1338
1339 if (!opt_kpageflags)
1340 opt_kpageflags = PROC_KPAGEFLAGS;
1341
1342 if (opt_cgroup || opt_list_cgroup)
1343 kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1344
1345 if (opt_list && opt_list_mapcnt)
1346 kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1347
1348 if (opt_mark_idle)
1349 page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1350
1351 if (opt_list && opt_pid)
1352 printf("voffset\t");
1353 if (opt_list && opt_file)
1354 printf("foffset\t");
1355 if (opt_list && opt_list_cgroup)
1356 printf("cgroup\t");
1357 if (opt_list && opt_list_mapcnt)
1358 printf("map-cnt\t");
1359
1360 if (opt_list == 1)
1361 printf("offset\tlen\tflags\n");
1362 if (opt_list == 2)
1363 printf("offset\tflags\n");
1364
1365 if (opt_file)
1366 walk_page_cache();
1367 else
1368 walk_addr_ranges();
1369
1370 if (opt_list == 1)
1371 flush_page_range();
1372
1373 if (opt_no_summary)
1374 return 0;
1375
1376 if (opt_list)
1377 printf("\n\n");
1378
1379 if (opt_file) {
1380 show_file(opt_file, &st);
1381 printf("\n");
1382 }
1383
1384 show_summary();
1385
1386 if (opt_list_mapcnt)
1387 close(kpagecount_fd);
1388
1389 if (page_idle_fd >= 0)
1390 close(page_idle_fd);
1391
1392 return 0;
1393 }
1394