xref: /linux/tools/mm/page-types.c (revision 7effbd18e496a954540fb6319db0d87d28a70496)
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 <sys/types.h>
26 #include <sys/errno.h>
27 #include <sys/fcntl.h>
28 #include <sys/mount.h>
29 #include <sys/statfs.h>
30 #include <sys/mman.h>
31 #include "../../include/uapi/linux/magic.h"
32 #include "../../include/uapi/linux/kernel-page-flags.h"
33 #include <api/fs/fs.h>
34 
35 #ifndef MAX_PATH
36 # define MAX_PATH 256
37 #endif
38 
39 #ifndef STR
40 # define _STR(x) #x
41 # define STR(x) _STR(x)
42 #endif
43 
44 /*
45  * pagemap kernel ABI bits
46  */
47 
48 #define PM_ENTRY_BYTES		8
49 #define PM_PFRAME_BITS		55
50 #define PM_PFRAME_MASK		((1LL << PM_PFRAME_BITS) - 1)
51 #define PM_PFRAME(x)		((x) & PM_PFRAME_MASK)
52 #define MAX_SWAPFILES_SHIFT	5
53 #define PM_SWAP_OFFSET(x)	(((x) & PM_PFRAME_MASK) >> MAX_SWAPFILES_SHIFT)
54 #define PM_SOFT_DIRTY		(1ULL << 55)
55 #define PM_MMAP_EXCLUSIVE	(1ULL << 56)
56 #define PM_FILE			(1ULL << 61)
57 #define PM_SWAP			(1ULL << 62)
58 #define PM_PRESENT		(1ULL << 63)
59 
60 /*
61  * kernel page flags
62  */
63 
64 #define KPF_BYTES		8
65 #define PROC_KPAGEFLAGS		"/proc/kpageflags"
66 #define PROC_KPAGECOUNT		"/proc/kpagecount"
67 #define PROC_KPAGECGROUP	"/proc/kpagecgroup"
68 
69 #define SYS_KERNEL_MM_PAGE_IDLE "/sys/kernel/mm/page_idle/bitmap"
70 
71 /* [32-] kernel hacking assistances */
72 #define KPF_RESERVED		32
73 #define KPF_MLOCKED		33
74 #define KPF_MAPPEDTODISK	34
75 #define KPF_PRIVATE		35
76 #define KPF_PRIVATE_2		36
77 #define KPF_OWNER_PRIVATE	37
78 #define KPF_ARCH		38
79 #define KPF_UNCACHED		39
80 #define KPF_SOFTDIRTY		40
81 #define KPF_ARCH_2		41
82 
83 /* [47-] take some arbitrary free slots for expanding overloaded flags
84  * not part of kernel API
85  */
86 #define KPF_ANON_EXCLUSIVE	47
87 #define KPF_READAHEAD		48
88 #define KPF_SLOB_FREE		49
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_SLOB_FREE]		= "P:slob_free",
145 	[KPF_SLUB_FROZEN]	= "A:slub_frozen",
146 	[KPF_SLUB_DEBUG]	= "E:slub_debug",
147 
148 	[KPF_FILE]		= "F:file",
149 	[KPF_SWAP]		= "w:swap",
150 	[KPF_MMAP_EXCLUSIVE]	= "1:mmap_exclusive",
151 };
152 
153 
154 /*
155  * data structures
156  */
157 
158 static int		opt_raw;	/* for kernel developers */
159 static int		opt_list;	/* list pages (in ranges) */
160 static int		opt_mark_idle;	/* set accessed bit */
161 static int		opt_no_summary;	/* don't show summary */
162 static pid_t		opt_pid;	/* process to walk */
163 const char		*opt_file;	/* file or directory path */
164 static uint64_t		opt_cgroup;	/* cgroup inode */
165 static int		opt_list_cgroup;/* list page cgroup */
166 static int		opt_list_mapcnt;/* list page map count */
167 static const char	*opt_kpageflags;/* kpageflags file to parse */
168 
169 #define MAX_ADDR_RANGES	1024
170 static int		nr_addr_ranges;
171 static unsigned long	opt_offset[MAX_ADDR_RANGES];
172 static unsigned long	opt_size[MAX_ADDR_RANGES];
173 
174 #define MAX_VMAS	10240
175 static int		nr_vmas;
176 static unsigned long	pg_start[MAX_VMAS];
177 static unsigned long	pg_end[MAX_VMAS];
178 
179 #define MAX_BIT_FILTERS	64
180 static int		nr_bit_filters;
181 static uint64_t		opt_mask[MAX_BIT_FILTERS];
182 static uint64_t		opt_bits[MAX_BIT_FILTERS];
183 
184 static int		page_size;
185 
186 static int		pagemap_fd;
187 static int		kpageflags_fd;
188 static int		kpagecount_fd = -1;
189 static int		kpagecgroup_fd = -1;
190 static int		page_idle_fd = -1;
191 
192 static int		opt_hwpoison;
193 static int		opt_unpoison;
194 
195 static const char	*hwpoison_debug_fs;
196 static int		hwpoison_inject_fd;
197 static int		hwpoison_forget_fd;
198 
199 #define HASH_SHIFT	13
200 #define HASH_SIZE	(1 << HASH_SHIFT)
201 #define HASH_MASK	(HASH_SIZE - 1)
202 #define HASH_KEY(flags)	(flags & HASH_MASK)
203 
204 static unsigned long	total_pages;
205 static unsigned long	nr_pages[HASH_SIZE];
206 static uint64_t		page_flags[HASH_SIZE];
207 
208 
209 /*
210  * helper functions
211  */
212 
213 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
214 
215 #define min_t(type, x, y) ({			\
216 	type __min1 = (x);			\
217 	type __min2 = (y);			\
218 	__min1 < __min2 ? __min1 : __min2; })
219 
220 #define max_t(type, x, y) ({			\
221 	type __max1 = (x);			\
222 	type __max2 = (y);			\
223 	__max1 > __max2 ? __max1 : __max2; })
224 
225 static unsigned long pages2mb(unsigned long pages)
226 {
227 	return (pages * page_size) >> 20;
228 }
229 
230 static void fatal(const char *x, ...)
231 {
232 	va_list ap;
233 
234 	va_start(ap, x);
235 	vfprintf(stderr, x, ap);
236 	va_end(ap);
237 	exit(EXIT_FAILURE);
238 }
239 
240 static int checked_open(const char *pathname, int flags)
241 {
242 	int fd = open(pathname, flags);
243 
244 	if (fd < 0) {
245 		perror(pathname);
246 		exit(EXIT_FAILURE);
247 	}
248 
249 	return fd;
250 }
251 
252 /*
253  * pagemap/kpageflags routines
254  */
255 
256 static unsigned long do_u64_read(int fd, const char *name,
257 				 uint64_t *buf,
258 				 unsigned long index,
259 				 unsigned long count)
260 {
261 	long bytes;
262 
263 	if (index > ULONG_MAX / 8)
264 		fatal("index overflow: %lu\n", index);
265 
266 	bytes = pread(fd, buf, count * 8, (off_t)index * 8);
267 	if (bytes < 0) {
268 		perror(name);
269 		exit(EXIT_FAILURE);
270 	}
271 	if (bytes % 8)
272 		fatal("partial read: %lu bytes\n", bytes);
273 
274 	return bytes / 8;
275 }
276 
277 static unsigned long kpageflags_read(uint64_t *buf,
278 				     unsigned long index,
279 				     unsigned long pages)
280 {
281 	return do_u64_read(kpageflags_fd, opt_kpageflags, buf, index, pages);
282 }
283 
284 static unsigned long kpagecgroup_read(uint64_t *buf,
285 				      unsigned long index,
286 				      unsigned long pages)
287 {
288 	if (kpagecgroup_fd < 0)
289 		return pages;
290 
291 	return do_u64_read(kpagecgroup_fd, opt_kpageflags, buf, index, pages);
292 }
293 
294 static unsigned long kpagecount_read(uint64_t *buf,
295 				     unsigned long index,
296 				     unsigned long pages)
297 {
298 	return kpagecount_fd < 0 ? pages :
299 		do_u64_read(kpagecount_fd, PROC_KPAGECOUNT,
300 			    buf, index, pages);
301 }
302 
303 static unsigned long pagemap_read(uint64_t *buf,
304 				  unsigned long index,
305 				  unsigned long pages)
306 {
307 	return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
308 }
309 
310 static unsigned long pagemap_pfn(uint64_t val)
311 {
312 	unsigned long pfn;
313 
314 	if (val & PM_PRESENT)
315 		pfn = PM_PFRAME(val);
316 	else
317 		pfn = 0;
318 
319 	return pfn;
320 }
321 
322 static unsigned long pagemap_swap_offset(uint64_t val)
323 {
324 	return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
325 }
326 
327 /*
328  * page flag names
329  */
330 
331 static char *page_flag_name(uint64_t flags)
332 {
333 	static char buf[65];
334 	int present;
335 	size_t i, j;
336 
337 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
338 		present = (flags >> i) & 1;
339 		if (!page_flag_names[i]) {
340 			if (present)
341 				fatal("unknown flag bit %d\n", i);
342 			continue;
343 		}
344 		buf[j++] = present ? page_flag_names[i][0] : '_';
345 	}
346 
347 	return buf;
348 }
349 
350 static char *page_flag_longname(uint64_t flags)
351 {
352 	static char buf[1024];
353 	size_t i, n;
354 
355 	for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
356 		if (!page_flag_names[i])
357 			continue;
358 		if ((flags >> i) & 1)
359 			n += snprintf(buf + n, sizeof(buf) - n, "%s,",
360 					page_flag_names[i] + 2);
361 	}
362 	if (n)
363 		n--;
364 	buf[n] = '\0';
365 
366 	return buf;
367 }
368 
369 
370 /*
371  * page list and summary
372  */
373 
374 static void show_page_range(unsigned long voffset, unsigned long offset,
375 			    unsigned long size, uint64_t flags,
376 			    uint64_t cgroup, uint64_t mapcnt)
377 {
378 	static uint64_t      flags0;
379 	static uint64_t	     cgroup0;
380 	static uint64_t      mapcnt0;
381 	static unsigned long voff;
382 	static unsigned long index;
383 	static unsigned long count;
384 
385 	if (flags == flags0 && cgroup == cgroup0 && mapcnt == mapcnt0 &&
386 	    offset == index + count && size && voffset == voff + count) {
387 		count += size;
388 		return;
389 	}
390 
391 	if (count) {
392 		if (opt_pid)
393 			printf("%lx\t", voff);
394 		if (opt_file)
395 			printf("%lx\t", voff);
396 		if (opt_list_cgroup)
397 			printf("@%llu\t", (unsigned long long)cgroup0);
398 		if (opt_list_mapcnt)
399 			printf("%lu\t", mapcnt0);
400 		printf("%lx\t%lx\t%s\n",
401 				index, count, page_flag_name(flags0));
402 	}
403 
404 	flags0 = flags;
405 	cgroup0 = cgroup;
406 	mapcnt0 = mapcnt;
407 	index  = offset;
408 	voff   = voffset;
409 	count  = size;
410 }
411 
412 static void flush_page_range(void)
413 {
414 	show_page_range(0, 0, 0, 0, 0, 0);
415 }
416 
417 static void show_page(unsigned long voffset, unsigned long offset,
418 		      uint64_t flags, uint64_t cgroup, uint64_t mapcnt)
419 {
420 	if (opt_pid)
421 		printf("%lx\t", voffset);
422 	if (opt_file)
423 		printf("%lx\t", voffset);
424 	if (opt_list_cgroup)
425 		printf("@%llu\t", (unsigned long long)cgroup);
426 	if (opt_list_mapcnt)
427 		printf("%lu\t", mapcnt);
428 
429 	printf("%lx\t%s\n", offset, page_flag_name(flags));
430 }
431 
432 static void show_summary(void)
433 {
434 	size_t i;
435 
436 	printf("             flags\tpage-count       MB"
437 		"  symbolic-flags\t\t\tlong-symbolic-flags\n");
438 
439 	for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
440 		if (nr_pages[i])
441 			printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
442 				(unsigned long long)page_flags[i],
443 				nr_pages[i],
444 				pages2mb(nr_pages[i]),
445 				page_flag_name(page_flags[i]),
446 				page_flag_longname(page_flags[i]));
447 	}
448 
449 	printf("             total\t%10lu %8lu\n",
450 			total_pages, pages2mb(total_pages));
451 }
452 
453 
454 /*
455  * page flag filters
456  */
457 
458 static int bit_mask_ok(uint64_t flags)
459 {
460 	int i;
461 
462 	for (i = 0; i < nr_bit_filters; i++) {
463 		if (opt_bits[i] == KPF_ALL_BITS) {
464 			if ((flags & opt_mask[i]) == 0)
465 				return 0;
466 		} else {
467 			if ((flags & opt_mask[i]) != opt_bits[i])
468 				return 0;
469 		}
470 	}
471 
472 	return 1;
473 }
474 
475 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
476 {
477 	/* Anonymous pages overload PG_mappedtodisk */
478 	if ((flags & BIT(ANON)) && (flags & BIT(MAPPEDTODISK)))
479 		flags ^= BIT(MAPPEDTODISK) | BIT(ANON_EXCLUSIVE);
480 
481 	/* SLOB/SLUB overload several page flags */
482 	if (flags & BIT(SLAB)) {
483 		if (flags & BIT(PRIVATE))
484 			flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
485 		if (flags & BIT(ACTIVE))
486 			flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
487 		if (flags & BIT(ERROR))
488 			flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
489 	}
490 
491 	/* PG_reclaim is overloaded as PG_readahead in the read path */
492 	if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
493 		flags ^= BIT(RECLAIM) | BIT(READAHEAD);
494 
495 	if (pme & PM_SOFT_DIRTY)
496 		flags |= BIT(SOFTDIRTY);
497 	if (pme & PM_FILE)
498 		flags |= BIT(FILE);
499 	if (pme & PM_SWAP)
500 		flags |= BIT(SWAP);
501 	if (pme & PM_MMAP_EXCLUSIVE)
502 		flags |= BIT(MMAP_EXCLUSIVE);
503 
504 	return flags;
505 }
506 
507 static uint64_t well_known_flags(uint64_t flags)
508 {
509 	/* hide flags intended only for kernel hacker */
510 	flags &= ~KPF_HACKERS_BITS;
511 
512 	/* hide non-hugeTLB compound pages */
513 	if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
514 		flags &= ~BITS_COMPOUND;
515 
516 	return flags;
517 }
518 
519 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
520 {
521 	if (opt_raw)
522 		flags = expand_overloaded_flags(flags, pme);
523 	else
524 		flags = well_known_flags(flags);
525 
526 	return flags;
527 }
528 
529 /*
530  * page actions
531  */
532 
533 static void prepare_hwpoison_fd(void)
534 {
535 	char buf[MAX_PATH + 1];
536 
537 	hwpoison_debug_fs = debugfs__mount();
538 	if (!hwpoison_debug_fs) {
539 		perror("mount debugfs");
540 		exit(EXIT_FAILURE);
541 	}
542 
543 	if (opt_hwpoison && !hwpoison_inject_fd) {
544 		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
545 			hwpoison_debug_fs);
546 		hwpoison_inject_fd = checked_open(buf, O_WRONLY);
547 	}
548 
549 	if (opt_unpoison && !hwpoison_forget_fd) {
550 		snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
551 			hwpoison_debug_fs);
552 		hwpoison_forget_fd = checked_open(buf, O_WRONLY);
553 	}
554 }
555 
556 static int hwpoison_page(unsigned long offset)
557 {
558 	char buf[100];
559 	int len;
560 
561 	len = sprintf(buf, "0x%lx\n", offset);
562 	len = write(hwpoison_inject_fd, buf, len);
563 	if (len < 0) {
564 		perror("hwpoison inject");
565 		return len;
566 	}
567 	return 0;
568 }
569 
570 static int unpoison_page(unsigned long offset)
571 {
572 	char buf[100];
573 	int len;
574 
575 	len = sprintf(buf, "0x%lx\n", offset);
576 	len = write(hwpoison_forget_fd, buf, len);
577 	if (len < 0) {
578 		perror("hwpoison forget");
579 		return len;
580 	}
581 	return 0;
582 }
583 
584 static int mark_page_idle(unsigned long offset)
585 {
586 	static unsigned long off;
587 	static uint64_t buf;
588 	int len;
589 
590 	if ((offset / 64 == off / 64) || buf == 0) {
591 		buf |= 1UL << (offset % 64);
592 		off = offset;
593 		return 0;
594 	}
595 
596 	len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
597 	if (len < 0) {
598 		perror("mark page idle");
599 		return len;
600 	}
601 
602 	buf = 1UL << (offset % 64);
603 	off = offset;
604 
605 	return 0;
606 }
607 
608 /*
609  * page frame walker
610  */
611 
612 static size_t hash_slot(uint64_t flags)
613 {
614 	size_t k = HASH_KEY(flags);
615 	size_t i;
616 
617 	/* Explicitly reserve slot 0 for flags 0: the following logic
618 	 * cannot distinguish an unoccupied slot from slot (flags==0).
619 	 */
620 	if (flags == 0)
621 		return 0;
622 
623 	/* search through the remaining (HASH_SIZE-1) slots */
624 	for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
625 		if (!k || k >= ARRAY_SIZE(page_flags))
626 			k = 1;
627 		if (page_flags[k] == 0) {
628 			page_flags[k] = flags;
629 			return k;
630 		}
631 		if (page_flags[k] == flags)
632 			return k;
633 	}
634 
635 	fatal("hash table full: bump up HASH_SHIFT?\n");
636 	exit(EXIT_FAILURE);
637 }
638 
639 static void add_page(unsigned long voffset, unsigned long offset,
640 		     uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
641 		     uint64_t pme)
642 {
643 	flags = kpageflags_flags(flags, pme);
644 
645 	if (!bit_mask_ok(flags))
646 		return;
647 
648 	if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
649 		return;
650 
651 	if (opt_hwpoison)
652 		hwpoison_page(offset);
653 	if (opt_unpoison)
654 		unpoison_page(offset);
655 
656 	if (opt_mark_idle)
657 		mark_page_idle(offset);
658 
659 	if (opt_list == 1)
660 		show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
661 	else if (opt_list == 2)
662 		show_page(voffset, offset, flags, cgroup, mapcnt);
663 
664 	nr_pages[hash_slot(flags)]++;
665 	total_pages++;
666 }
667 
668 #define KPAGEFLAGS_BATCH	(64 << 10)	/* 64k pages */
669 static void walk_pfn(unsigned long voffset,
670 		     unsigned long index,
671 		     unsigned long count,
672 		     uint64_t pme)
673 {
674 	uint64_t buf[KPAGEFLAGS_BATCH];
675 	uint64_t cgi[KPAGEFLAGS_BATCH];
676 	uint64_t cnt[KPAGEFLAGS_BATCH];
677 	unsigned long batch;
678 	unsigned long pages;
679 	unsigned long i;
680 
681 	/*
682 	 * kpagecgroup_read() reads only if kpagecgroup were opened, but
683 	 * /proc/kpagecgroup might even not exist, so it's better to fill
684 	 * them with zeros here.
685 	 */
686 	if (count == 1)
687 		cgi[0] = 0;
688 	else
689 		memset(cgi, 0, sizeof cgi);
690 
691 	while (count) {
692 		batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
693 		pages = kpageflags_read(buf, index, batch);
694 		if (pages == 0)
695 			break;
696 
697 		if (kpagecgroup_read(cgi, index, pages) != pages)
698 			fatal("kpagecgroup returned fewer pages than expected");
699 
700 		if (kpagecount_read(cnt, index, pages) != pages)
701 			fatal("kpagecount returned fewer pages than expected");
702 
703 		for (i = 0; i < pages; i++)
704 			add_page(voffset + i, index + i,
705 				 buf[i], cgi[i], cnt[i], pme);
706 
707 		index += pages;
708 		count -= pages;
709 	}
710 }
711 
712 static void walk_swap(unsigned long voffset, uint64_t pme)
713 {
714 	uint64_t flags = kpageflags_flags(0, pme);
715 
716 	if (!bit_mask_ok(flags))
717 		return;
718 
719 	if (opt_cgroup)
720 		return;
721 
722 	if (opt_list == 1)
723 		show_page_range(voffset, pagemap_swap_offset(pme),
724 				1, flags, 0, 0);
725 	else if (opt_list == 2)
726 		show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
727 
728 	nr_pages[hash_slot(flags)]++;
729 	total_pages++;
730 }
731 
732 #define PAGEMAP_BATCH	(64 << 10)
733 static void walk_vma(unsigned long index, unsigned long count)
734 {
735 	uint64_t buf[PAGEMAP_BATCH];
736 	unsigned long batch;
737 	unsigned long pages;
738 	unsigned long pfn;
739 	unsigned long i;
740 
741 	while (count) {
742 		batch = min_t(unsigned long, count, PAGEMAP_BATCH);
743 		pages = pagemap_read(buf, index, batch);
744 		if (pages == 0)
745 			break;
746 
747 		for (i = 0; i < pages; i++) {
748 			pfn = pagemap_pfn(buf[i]);
749 			if (pfn)
750 				walk_pfn(index + i, pfn, 1, buf[i]);
751 			if (buf[i] & PM_SWAP)
752 				walk_swap(index + i, buf[i]);
753 		}
754 
755 		index += pages;
756 		count -= pages;
757 	}
758 }
759 
760 static void walk_task(unsigned long index, unsigned long count)
761 {
762 	const unsigned long end = index + count;
763 	unsigned long start;
764 	int i = 0;
765 
766 	while (index < end) {
767 
768 		while (pg_end[i] <= index)
769 			if (++i >= nr_vmas)
770 				return;
771 		if (pg_start[i] >= end)
772 			return;
773 
774 		start = max_t(unsigned long, pg_start[i], index);
775 		index = min_t(unsigned long, pg_end[i], end);
776 
777 		assert(start < index);
778 		walk_vma(start, index - start);
779 	}
780 }
781 
782 static void add_addr_range(unsigned long offset, unsigned long size)
783 {
784 	if (nr_addr_ranges >= MAX_ADDR_RANGES)
785 		fatal("too many addr ranges\n");
786 
787 	opt_offset[nr_addr_ranges] = offset;
788 	opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
789 	nr_addr_ranges++;
790 }
791 
792 static void walk_addr_ranges(void)
793 {
794 	int i;
795 
796 	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
797 
798 	if (!nr_addr_ranges)
799 		add_addr_range(0, ULONG_MAX);
800 
801 	for (i = 0; i < nr_addr_ranges; i++)
802 		if (!opt_pid)
803 			walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
804 		else
805 			walk_task(opt_offset[i], opt_size[i]);
806 
807 	if (opt_mark_idle)
808 		mark_page_idle(0);
809 
810 	close(kpageflags_fd);
811 }
812 
813 
814 /*
815  * user interface
816  */
817 
818 static const char *page_flag_type(uint64_t flag)
819 {
820 	if (flag & KPF_HACKERS_BITS)
821 		return "(r)";
822 	if (flag & KPF_OVERLOADED_BITS)
823 		return "(o)";
824 	return "   ";
825 }
826 
827 static void usage(void)
828 {
829 	size_t i, j;
830 
831 	printf(
832 "page-types [options]\n"
833 "            -r|--raw                   Raw mode, for kernel developers\n"
834 "            -d|--describe flags        Describe flags\n"
835 "            -a|--addr    addr-spec     Walk a range of pages\n"
836 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
837 "            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
838 "            -p|--pid     pid           Walk process address space\n"
839 "            -f|--file    filename      Walk file address space\n"
840 "            -i|--mark-idle             Mark pages idle\n"
841 "            -l|--list                  Show page details in ranges\n"
842 "            -L|--list-each             Show page details one by one\n"
843 "            -C|--list-cgroup           Show cgroup inode for pages\n"
844 "            -M|--list-mapcnt           Show page map count\n"
845 "            -N|--no-summary            Don't show summary info\n"
846 "            -X|--hwpoison              hwpoison pages\n"
847 "            -x|--unpoison              unpoison pages\n"
848 "            -F|--kpageflags filename   kpageflags file to parse\n"
849 "            -h|--help                  Show this usage message\n"
850 "flags:\n"
851 "            0x10                       bitfield format, e.g.\n"
852 "            anon                       bit-name, e.g.\n"
853 "            0x10,anon                  comma-separated list, e.g.\n"
854 "addr-spec:\n"
855 "            N                          one page at offset N (unit: pages)\n"
856 "            N+M                        pages range from N to N+M-1\n"
857 "            N,M                        pages range from N to M-1\n"
858 "            N,                         pages range from N to end\n"
859 "            ,M                         pages range from 0 to M-1\n"
860 "bits-spec:\n"
861 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
862 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
863 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
864 "            =bit1,bit2                 flags == (bit1|bit2)\n"
865 "bit-names:\n"
866 	);
867 
868 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
869 		if (!page_flag_names[i])
870 			continue;
871 		printf("%16s%s", page_flag_names[i] + 2,
872 				 page_flag_type(1ULL << i));
873 		if (++j > 3) {
874 			j = 0;
875 			putchar('\n');
876 		}
877 	}
878 	printf("\n                                   "
879 		"(r) raw mode bits  (o) overloaded bits\n");
880 }
881 
882 static unsigned long long parse_number(const char *str)
883 {
884 	unsigned long long n;
885 
886 	n = strtoll(str, NULL, 0);
887 
888 	if (n == 0 && str[0] != '0')
889 		fatal("invalid name or number: %s\n", str);
890 
891 	return n;
892 }
893 
894 static void parse_pid(const char *str)
895 {
896 	FILE *file;
897 	char buf[5000];
898 
899 	opt_pid = parse_number(str);
900 
901 	sprintf(buf, "/proc/%d/pagemap", opt_pid);
902 	pagemap_fd = checked_open(buf, O_RDONLY);
903 
904 	sprintf(buf, "/proc/%d/maps", opt_pid);
905 	file = fopen(buf, "r");
906 	if (!file) {
907 		perror(buf);
908 		exit(EXIT_FAILURE);
909 	}
910 
911 	while (fgets(buf, sizeof(buf), file) != NULL) {
912 		unsigned long vm_start;
913 		unsigned long vm_end;
914 		unsigned long long pgoff;
915 		int major, minor;
916 		char r, w, x, s;
917 		unsigned long ino;
918 		int n;
919 
920 		n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
921 			   &vm_start,
922 			   &vm_end,
923 			   &r, &w, &x, &s,
924 			   &pgoff,
925 			   &major, &minor,
926 			   &ino);
927 		if (n < 10) {
928 			fprintf(stderr, "unexpected line: %s\n", buf);
929 			continue;
930 		}
931 		pg_start[nr_vmas] = vm_start / page_size;
932 		pg_end[nr_vmas] = vm_end / page_size;
933 		if (++nr_vmas >= MAX_VMAS) {
934 			fprintf(stderr, "too many VMAs\n");
935 			break;
936 		}
937 	}
938 	fclose(file);
939 }
940 
941 static void show_file(const char *name, const struct stat *st)
942 {
943 	unsigned long long size = st->st_size;
944 	char atime[64], mtime[64];
945 	long now = time(NULL);
946 
947 	printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
948 			name, (unsigned)st->st_ino,
949 			size, (size + page_size - 1) / page_size);
950 
951 	strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
952 	strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
953 
954 	printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
955 			mtime, now - st->st_mtime,
956 			atime, now - st->st_atime);
957 }
958 
959 static sigjmp_buf sigbus_jmp;
960 
961 static void * volatile sigbus_addr;
962 
963 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
964 {
965 	(void)sig;
966 	(void)ucontex;
967 	sigbus_addr = info ? info->si_addr : NULL;
968 	siglongjmp(sigbus_jmp, 1);
969 }
970 
971 static struct sigaction sigbus_action = {
972 	.sa_sigaction = sigbus_handler,
973 	.sa_flags = SA_SIGINFO,
974 };
975 
976 static void walk_file_range(const char *name, int fd,
977 			    unsigned long off, unsigned long end)
978 {
979 	uint8_t vec[PAGEMAP_BATCH];
980 	uint64_t buf[PAGEMAP_BATCH], flags;
981 	uint64_t cgroup = 0;
982 	uint64_t mapcnt = 0;
983 	unsigned long nr_pages, pfn, i;
984 	ssize_t len;
985 	void *ptr;
986 	int first = 1;
987 
988 	for (; off < end; off += len) {
989 		nr_pages = (end - off + page_size - 1) / page_size;
990 		if (nr_pages > PAGEMAP_BATCH)
991 			nr_pages = PAGEMAP_BATCH;
992 		len = nr_pages * page_size;
993 
994 		ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
995 		if (ptr == MAP_FAILED)
996 			fatal("mmap failed: %s", name);
997 
998 		/* determine cached pages */
999 		if (mincore(ptr, len, vec))
1000 			fatal("mincore failed: %s", name);
1001 
1002 		/* turn off readahead */
1003 		if (madvise(ptr, len, MADV_RANDOM))
1004 			fatal("madvice failed: %s", name);
1005 
1006 		if (sigsetjmp(sigbus_jmp, 1)) {
1007 			end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1008 			fprintf(stderr, "got sigbus at offset %lld: %s\n",
1009 					(long long)end, name);
1010 			goto got_sigbus;
1011 		}
1012 
1013 		/* populate ptes */
1014 		for (i = 0; i < nr_pages ; i++) {
1015 			if (vec[i] & 1)
1016 				(void)*(volatile int *)(ptr + i * page_size);
1017 		}
1018 got_sigbus:
1019 
1020 		/* turn off harvesting reference bits */
1021 		if (madvise(ptr, len, MADV_SEQUENTIAL))
1022 			fatal("madvice failed: %s", name);
1023 
1024 		if (pagemap_read(buf, (unsigned long)ptr / page_size,
1025 					nr_pages) != nr_pages)
1026 			fatal("cannot read pagemap");
1027 
1028 		munmap(ptr, len);
1029 
1030 		for (i = 0; i < nr_pages; i++) {
1031 			pfn = pagemap_pfn(buf[i]);
1032 			if (!pfn)
1033 				continue;
1034 			if (!kpageflags_read(&flags, pfn, 1))
1035 				continue;
1036 			if (!kpagecgroup_read(&cgroup, pfn, 1))
1037 				fatal("kpagecgroup_read failed");
1038 			if (!kpagecount_read(&mapcnt, pfn, 1))
1039 				fatal("kpagecount_read failed");
1040 			if (first && opt_list) {
1041 				first = 0;
1042 				flush_page_range();
1043 			}
1044 			add_page(off / page_size + i, pfn,
1045 				 flags, cgroup, mapcnt, buf[i]);
1046 		}
1047 	}
1048 }
1049 
1050 static void walk_file(const char *name, const struct stat *st)
1051 {
1052 	int i;
1053 	int fd;
1054 
1055 	fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
1056 
1057 	if (!nr_addr_ranges)
1058 		add_addr_range(0, st->st_size / page_size);
1059 
1060 	for (i = 0; i < nr_addr_ranges; i++)
1061 		walk_file_range(name, fd, opt_offset[i] * page_size,
1062 				(opt_offset[i] + opt_size[i]) * page_size);
1063 
1064 	close(fd);
1065 }
1066 
1067 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1068 {
1069 	(void)f;
1070 	switch (type) {
1071 	case FTW_F:
1072 		if (S_ISREG(st->st_mode))
1073 			walk_file(name, st);
1074 		break;
1075 	case FTW_DNR:
1076 		fprintf(stderr, "cannot read dir: %s\n", name);
1077 		break;
1078 	}
1079 	return 0;
1080 }
1081 
1082 struct stat st;
1083 
1084 static void walk_page_cache(void)
1085 {
1086 	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1087 	pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1088 	sigaction(SIGBUS, &sigbus_action, NULL);
1089 
1090 	if (stat(opt_file, &st))
1091 		fatal("stat failed: %s\n", opt_file);
1092 
1093 	if (S_ISREG(st.st_mode)) {
1094 		walk_file(opt_file, &st);
1095 	} else if (S_ISDIR(st.st_mode)) {
1096 		/* do not follow symlinks and mountpoints */
1097 		if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1098 			fatal("nftw failed: %s\n", opt_file);
1099 	} else
1100 		fatal("unhandled file type: %s\n", opt_file);
1101 
1102 	close(kpageflags_fd);
1103 	close(pagemap_fd);
1104 	signal(SIGBUS, SIG_DFL);
1105 }
1106 
1107 static void parse_file(const char *name)
1108 {
1109 	opt_file = name;
1110 }
1111 
1112 static void parse_cgroup(const char *path)
1113 {
1114 	if (path[0] == '@') {
1115 		opt_cgroup = parse_number(path + 1);
1116 		return;
1117 	}
1118 
1119 	struct stat st;
1120 
1121 	if (stat(path, &st))
1122 		fatal("stat failed: %s: %m\n", path);
1123 
1124 	if (!S_ISDIR(st.st_mode))
1125 		fatal("cgroup supposed to be a directory: %s\n", path);
1126 
1127 	opt_cgroup = st.st_ino;
1128 }
1129 
1130 static void parse_addr_range(const char *optarg)
1131 {
1132 	unsigned long offset;
1133 	unsigned long size;
1134 	char *p;
1135 
1136 	p = strchr(optarg, ',');
1137 	if (!p)
1138 		p = strchr(optarg, '+');
1139 
1140 	if (p == optarg) {
1141 		offset = 0;
1142 		size   = parse_number(p + 1);
1143 	} else if (p) {
1144 		offset = parse_number(optarg);
1145 		if (p[1] == '\0')
1146 			size = ULONG_MAX;
1147 		else {
1148 			size = parse_number(p + 1);
1149 			if (*p == ',') {
1150 				if (size < offset)
1151 					fatal("invalid range: %lu,%lu\n",
1152 							offset, size);
1153 				size -= offset;
1154 			}
1155 		}
1156 	} else {
1157 		offset = parse_number(optarg);
1158 		size   = 1;
1159 	}
1160 
1161 	add_addr_range(offset, size);
1162 }
1163 
1164 static void add_bits_filter(uint64_t mask, uint64_t bits)
1165 {
1166 	if (nr_bit_filters >= MAX_BIT_FILTERS)
1167 		fatal("too much bit filters\n");
1168 
1169 	opt_mask[nr_bit_filters] = mask;
1170 	opt_bits[nr_bit_filters] = bits;
1171 	nr_bit_filters++;
1172 }
1173 
1174 static uint64_t parse_flag_name(const char *str, int len)
1175 {
1176 	size_t i;
1177 
1178 	if (!*str || !len)
1179 		return 0;
1180 
1181 	if (len <= 8 && !strncmp(str, "compound", len))
1182 		return BITS_COMPOUND;
1183 
1184 	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1185 		if (!page_flag_names[i])
1186 			continue;
1187 		if (!strncmp(str, page_flag_names[i] + 2, len))
1188 			return 1ULL << i;
1189 	}
1190 
1191 	return parse_number(str);
1192 }
1193 
1194 static uint64_t parse_flag_names(const char *str, int all)
1195 {
1196 	const char *p    = str;
1197 	uint64_t   flags = 0;
1198 
1199 	while (1) {
1200 		if (*p == ',' || *p == '=' || *p == '\0') {
1201 			if ((*str != '~') || (*str == '~' && all && *++str))
1202 				flags |= parse_flag_name(str, p - str);
1203 			if (*p != ',')
1204 				break;
1205 			str = p + 1;
1206 		}
1207 		p++;
1208 	}
1209 
1210 	return flags;
1211 }
1212 
1213 static void parse_bits_mask(const char *optarg)
1214 {
1215 	uint64_t mask;
1216 	uint64_t bits;
1217 	const char *p;
1218 
1219 	p = strchr(optarg, '=');
1220 	if (p == optarg) {
1221 		mask = KPF_ALL_BITS;
1222 		bits = parse_flag_names(p + 1, 0);
1223 	} else if (p) {
1224 		mask = parse_flag_names(optarg, 0);
1225 		bits = parse_flag_names(p + 1, 0);
1226 	} else if (strchr(optarg, '~')) {
1227 		mask = parse_flag_names(optarg, 1);
1228 		bits = parse_flag_names(optarg, 0);
1229 	} else {
1230 		mask = parse_flag_names(optarg, 0);
1231 		bits = KPF_ALL_BITS;
1232 	}
1233 
1234 	add_bits_filter(mask, bits);
1235 }
1236 
1237 static void parse_kpageflags(const char *name)
1238 {
1239 	opt_kpageflags = name;
1240 }
1241 
1242 static void describe_flags(const char *optarg)
1243 {
1244 	uint64_t flags = parse_flag_names(optarg, 0);
1245 
1246 	printf("0x%016llx\t%s\t%s\n",
1247 		(unsigned long long)flags,
1248 		page_flag_name(flags),
1249 		page_flag_longname(flags));
1250 }
1251 
1252 static const struct option opts[] = {
1253 	{ "raw"       , 0, NULL, 'r' },
1254 	{ "pid"       , 1, NULL, 'p' },
1255 	{ "file"      , 1, NULL, 'f' },
1256 	{ "addr"      , 1, NULL, 'a' },
1257 	{ "bits"      , 1, NULL, 'b' },
1258 	{ "cgroup"    , 1, NULL, 'c' },
1259 	{ "describe"  , 1, NULL, 'd' },
1260 	{ "mark-idle" , 0, NULL, 'i' },
1261 	{ "list"      , 0, NULL, 'l' },
1262 	{ "list-each" , 0, NULL, 'L' },
1263 	{ "list-cgroup", 0, NULL, 'C' },
1264 	{ "list-mapcnt", 0, NULL, 'M' },
1265 	{ "no-summary", 0, NULL, 'N' },
1266 	{ "hwpoison"  , 0, NULL, 'X' },
1267 	{ "unpoison"  , 0, NULL, 'x' },
1268 	{ "kpageflags", 0, NULL, 'F' },
1269 	{ "help"      , 0, NULL, 'h' },
1270 	{ NULL        , 0, NULL, 0 }
1271 };
1272 
1273 int main(int argc, char *argv[])
1274 {
1275 	int c;
1276 
1277 	page_size = getpagesize();
1278 
1279 	while ((c = getopt_long(argc, argv,
1280 				"rp:f:a:b:d:c:CilLMNXxF:h",
1281 				opts, NULL)) != -1) {
1282 		switch (c) {
1283 		case 'r':
1284 			opt_raw = 1;
1285 			break;
1286 		case 'p':
1287 			parse_pid(optarg);
1288 			break;
1289 		case 'f':
1290 			parse_file(optarg);
1291 			break;
1292 		case 'a':
1293 			parse_addr_range(optarg);
1294 			break;
1295 		case 'b':
1296 			parse_bits_mask(optarg);
1297 			break;
1298 		case 'c':
1299 			parse_cgroup(optarg);
1300 			break;
1301 		case 'C':
1302 			opt_list_cgroup = 1;
1303 			break;
1304 		case 'd':
1305 			describe_flags(optarg);
1306 			exit(0);
1307 		case 'i':
1308 			opt_mark_idle = 1;
1309 			break;
1310 		case 'l':
1311 			opt_list = 1;
1312 			break;
1313 		case 'L':
1314 			opt_list = 2;
1315 			break;
1316 		case 'M':
1317 			opt_list_mapcnt = 1;
1318 			break;
1319 		case 'N':
1320 			opt_no_summary = 1;
1321 			break;
1322 		case 'X':
1323 			opt_hwpoison = 1;
1324 			prepare_hwpoison_fd();
1325 			break;
1326 		case 'x':
1327 			opt_unpoison = 1;
1328 			prepare_hwpoison_fd();
1329 			break;
1330 		case 'F':
1331 			parse_kpageflags(optarg);
1332 			break;
1333 		case 'h':
1334 			usage();
1335 			exit(0);
1336 		default:
1337 			usage();
1338 			exit(1);
1339 		}
1340 	}
1341 
1342 	if (!opt_kpageflags)
1343 		opt_kpageflags = PROC_KPAGEFLAGS;
1344 
1345 	if (opt_cgroup || opt_list_cgroup)
1346 		kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1347 
1348 	if (opt_list && opt_list_mapcnt)
1349 		kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1350 
1351 	if (opt_mark_idle)
1352 		page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1353 
1354 	if (opt_list && opt_pid)
1355 		printf("voffset\t");
1356 	if (opt_list && opt_file)
1357 		printf("foffset\t");
1358 	if (opt_list && opt_list_cgroup)
1359 		printf("cgroup\t");
1360 	if (opt_list && opt_list_mapcnt)
1361 		printf("map-cnt\t");
1362 
1363 	if (opt_list == 1)
1364 		printf("offset\tlen\tflags\n");
1365 	if (opt_list == 2)
1366 		printf("offset\tflags\n");
1367 
1368 	if (opt_file)
1369 		walk_page_cache();
1370 	else
1371 		walk_addr_ranges();
1372 
1373 	if (opt_list == 1)
1374 		flush_page_range();
1375 
1376 	if (opt_no_summary)
1377 		return 0;
1378 
1379 	if (opt_list)
1380 		printf("\n\n");
1381 
1382 	if (opt_file) {
1383 		show_file(opt_file, &st);
1384 		printf("\n");
1385 	}
1386 
1387 	show_summary();
1388 
1389 	if (opt_list_mapcnt)
1390 		close(kpagecount_fd);
1391 
1392 	if (page_idle_fd >= 0)
1393 		close(page_idle_fd);
1394 
1395 	return 0;
1396 }
1397