xref: /linux/tools/mm/page-types.c (revision fd7d598270724cc787982ea48bbe17ad383a8b7f)
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_SLUB_FROZEN		50
89 #define KPF_SLUB_DEBUG		51
90 #define KPF_FILE		61
91 #define KPF_SWAP		62
92 #define KPF_MMAP_EXCLUSIVE	63
93 
94 #define KPF_ALL_BITS		((uint64_t)~0ULL)
95 #define KPF_HACKERS_BITS	(0xffffULL << 32)
96 #define KPF_OVERLOADED_BITS	(0xffffULL << 48)
97 #define BIT(name)		(1ULL << KPF_##name)
98 #define BITS_COMPOUND		(BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
99 
100 static const char * const page_flag_names[] = {
101 	[KPF_LOCKED]		= "L:locked",
102 	[KPF_ERROR]		= "E:error",
103 	[KPF_REFERENCED]	= "R:referenced",
104 	[KPF_UPTODATE]		= "U:uptodate",
105 	[KPF_DIRTY]		= "D:dirty",
106 	[KPF_LRU]		= "l:lru",
107 	[KPF_ACTIVE]		= "A:active",
108 	[KPF_SLAB]		= "S:slab",
109 	[KPF_WRITEBACK]		= "W:writeback",
110 	[KPF_RECLAIM]		= "I:reclaim",
111 	[KPF_BUDDY]		= "B:buddy",
112 
113 	[KPF_MMAP]		= "M:mmap",
114 	[KPF_ANON]		= "a:anonymous",
115 	[KPF_SWAPCACHE]		= "s:swapcache",
116 	[KPF_SWAPBACKED]	= "b:swapbacked",
117 	[KPF_COMPOUND_HEAD]	= "H:compound_head",
118 	[KPF_COMPOUND_TAIL]	= "T:compound_tail",
119 	[KPF_HUGE]		= "G:huge",
120 	[KPF_UNEVICTABLE]	= "u:unevictable",
121 	[KPF_HWPOISON]		= "X:hwpoison",
122 	[KPF_NOPAGE]		= "n:nopage",
123 	[KPF_KSM]		= "x:ksm",
124 	[KPF_THP]		= "t:thp",
125 	[KPF_OFFLINE]		= "o:offline",
126 	[KPF_PGTABLE]		= "g:pgtable",
127 	[KPF_ZERO_PAGE]		= "z:zero_page",
128 	[KPF_IDLE]              = "i:idle_page",
129 
130 	[KPF_RESERVED]		= "r:reserved",
131 	[KPF_MLOCKED]		= "m:mlocked",
132 	[KPF_MAPPEDTODISK]	= "d:mappedtodisk",
133 	[KPF_PRIVATE]		= "P:private",
134 	[KPF_PRIVATE_2]		= "p:private_2",
135 	[KPF_OWNER_PRIVATE]	= "O:owner_private",
136 	[KPF_ARCH]		= "h:arch",
137 	[KPF_UNCACHED]		= "c:uncached",
138 	[KPF_SOFTDIRTY]		= "f:softdirty",
139 	[KPF_ARCH_2]		= "H:arch_2",
140 
141 	[KPF_ANON_EXCLUSIVE]	= "d:anon_exclusive",
142 	[KPF_READAHEAD]		= "I:readahead",
143 	[KPF_SLUB_FROZEN]	= "A:slub_frozen",
144 	[KPF_SLUB_DEBUG]	= "E:slub_debug",
145 
146 	[KPF_FILE]		= "F:file",
147 	[KPF_SWAP]		= "w:swap",
148 	[KPF_MMAP_EXCLUSIVE]	= "1:mmap_exclusive",
149 };
150 
151 
152 /*
153  * data structures
154  */
155 
156 static int		opt_raw;	/* for kernel developers */
157 static int		opt_list;	/* list pages (in ranges) */
158 static int		opt_mark_idle;	/* set accessed bit */
159 static int		opt_no_summary;	/* don't show summary */
160 static pid_t		opt_pid;	/* process to walk */
161 const char		*opt_file;	/* file or directory path */
162 static uint64_t		opt_cgroup;	/* cgroup inode */
163 static int		opt_list_cgroup;/* list page cgroup */
164 static int		opt_list_mapcnt;/* list page map count */
165 static const char	*opt_kpageflags;/* kpageflags file to parse */
166 
167 #define MAX_ADDR_RANGES	1024
168 static int		nr_addr_ranges;
169 static unsigned long	opt_offset[MAX_ADDR_RANGES];
170 static unsigned long	opt_size[MAX_ADDR_RANGES];
171 
172 #define MAX_VMAS	10240
173 static int		nr_vmas;
174 static unsigned long	pg_start[MAX_VMAS];
175 static unsigned long	pg_end[MAX_VMAS];
176 
177 #define MAX_BIT_FILTERS	64
178 static int		nr_bit_filters;
179 static uint64_t		opt_mask[MAX_BIT_FILTERS];
180 static uint64_t		opt_bits[MAX_BIT_FILTERS];
181 
182 static int		page_size;
183 
184 static int		pagemap_fd;
185 static int		kpageflags_fd;
186 static int		kpagecount_fd = -1;
187 static int		kpagecgroup_fd = -1;
188 static int		page_idle_fd = -1;
189 
190 static int		opt_hwpoison;
191 static int		opt_unpoison;
192 
193 static const 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 
223 static unsigned long pages2mb(unsigned long pages)
224 {
225 	return (pages * page_size) >> 20;
226 }
227 
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 
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 
254 static unsigned long do_u64_read(int fd, const 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 
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, opt_kpageflags, buf, index, pages);
280 }
281 
282 static unsigned long kpagecgroup_read(uint64_t *buf,
283 				      unsigned long index,
284 				      unsigned long pages)
285 {
286 	if (kpagecgroup_fd < 0)
287 		return pages;
288 
289 	return do_u64_read(kpagecgroup_fd, opt_kpageflags, buf, index, pages);
290 }
291 
292 static unsigned long kpagecount_read(uint64_t *buf,
293 				     unsigned long index,
294 				     unsigned long pages)
295 {
296 	return kpagecount_fd < 0 ? pages :
297 		do_u64_read(kpagecount_fd, PROC_KPAGECOUNT,
298 			    buf, index, pages);
299 }
300 
301 static unsigned long pagemap_read(uint64_t *buf,
302 				  unsigned long index,
303 				  unsigned long pages)
304 {
305 	return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
306 }
307 
308 static unsigned long pagemap_pfn(uint64_t val)
309 {
310 	unsigned long pfn;
311 
312 	if (val & PM_PRESENT)
313 		pfn = PM_PFRAME(val);
314 	else
315 		pfn = 0;
316 
317 	return pfn;
318 }
319 
320 static unsigned long pagemap_swap_offset(uint64_t val)
321 {
322 	return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
323 }
324 
325 /*
326  * page flag names
327  */
328 
329 static char *page_flag_name(uint64_t flags)
330 {
331 	static char buf[65];
332 	int present;
333 	size_t i, j;
334 
335 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
336 		present = (flags >> i) & 1;
337 		if (!page_flag_names[i]) {
338 			if (present)
339 				fatal("unknown flag bit %d\n", i);
340 			continue;
341 		}
342 		buf[j++] = present ? page_flag_names[i][0] : '_';
343 	}
344 
345 	return buf;
346 }
347 
348 static char *page_flag_longname(uint64_t flags)
349 {
350 	static char buf[1024];
351 	size_t i, n;
352 
353 	for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
354 		if (!page_flag_names[i])
355 			continue;
356 		if ((flags >> i) & 1)
357 			n += snprintf(buf + n, sizeof(buf) - n, "%s,",
358 					page_flag_names[i] + 2);
359 	}
360 	if (n)
361 		n--;
362 	buf[n] = '\0';
363 
364 	return buf;
365 }
366 
367 
368 /*
369  * page list and summary
370  */
371 
372 static void show_page_range(unsigned long voffset, unsigned long offset,
373 			    unsigned long size, uint64_t flags,
374 			    uint64_t cgroup, uint64_t mapcnt)
375 {
376 	static uint64_t      flags0;
377 	static uint64_t	     cgroup0;
378 	static uint64_t      mapcnt0;
379 	static unsigned long voff;
380 	static unsigned long index;
381 	static unsigned long count;
382 
383 	if (flags == flags0 && cgroup == cgroup0 && mapcnt == mapcnt0 &&
384 	    offset == index + count && size && voffset == voff + count) {
385 		count += size;
386 		return;
387 	}
388 
389 	if (count) {
390 		if (opt_pid)
391 			printf("%lx\t", voff);
392 		if (opt_file)
393 			printf("%lx\t", voff);
394 		if (opt_list_cgroup)
395 			printf("@%llu\t", (unsigned long long)cgroup0);
396 		if (opt_list_mapcnt)
397 			printf("%lu\t", mapcnt0);
398 		printf("%lx\t%lx\t%s\n",
399 				index, count, page_flag_name(flags0));
400 	}
401 
402 	flags0 = flags;
403 	cgroup0 = cgroup;
404 	mapcnt0 = mapcnt;
405 	index  = offset;
406 	voff   = voffset;
407 	count  = size;
408 }
409 
410 static void flush_page_range(void)
411 {
412 	show_page_range(0, 0, 0, 0, 0, 0);
413 }
414 
415 static void show_page(unsigned long voffset, unsigned long offset,
416 		      uint64_t flags, uint64_t cgroup, uint64_t mapcnt)
417 {
418 	if (opt_pid)
419 		printf("%lx\t", voffset);
420 	if (opt_file)
421 		printf("%lx\t", voffset);
422 	if (opt_list_cgroup)
423 		printf("@%llu\t", (unsigned long long)cgroup);
424 	if (opt_list_mapcnt)
425 		printf("%lu\t", mapcnt);
426 
427 	printf("%lx\t%s\n", offset, page_flag_name(flags));
428 }
429 
430 static void show_summary(void)
431 {
432 	size_t i;
433 
434 	printf("             flags\tpage-count       MB"
435 		"  symbolic-flags\t\t\tlong-symbolic-flags\n");
436 
437 	for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
438 		if (nr_pages[i])
439 			printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
440 				(unsigned long long)page_flags[i],
441 				nr_pages[i],
442 				pages2mb(nr_pages[i]),
443 				page_flag_name(page_flags[i]),
444 				page_flag_longname(page_flags[i]));
445 	}
446 
447 	printf("             total\t%10lu %8lu\n",
448 			total_pages, pages2mb(total_pages));
449 }
450 
451 
452 /*
453  * page flag filters
454  */
455 
456 static int bit_mask_ok(uint64_t flags)
457 {
458 	int i;
459 
460 	for (i = 0; i < nr_bit_filters; i++) {
461 		if (opt_bits[i] == KPF_ALL_BITS) {
462 			if ((flags & opt_mask[i]) == 0)
463 				return 0;
464 		} else {
465 			if ((flags & opt_mask[i]) != opt_bits[i])
466 				return 0;
467 		}
468 	}
469 
470 	return 1;
471 }
472 
473 static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
474 {
475 	/* Anonymous pages overload PG_mappedtodisk */
476 	if ((flags & BIT(ANON)) && (flags & BIT(MAPPEDTODISK)))
477 		flags ^= BIT(MAPPEDTODISK) | BIT(ANON_EXCLUSIVE);
478 
479 	/* SLUB overloads several page flags */
480 	if (flags & BIT(SLAB)) {
481 		if (flags & BIT(ACTIVE))
482 			flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
483 		if (flags & BIT(ERROR))
484 			flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
485 	}
486 
487 	/* PG_reclaim is overloaded as PG_readahead in the read path */
488 	if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
489 		flags ^= BIT(RECLAIM) | BIT(READAHEAD);
490 
491 	if (pme & PM_SOFT_DIRTY)
492 		flags |= BIT(SOFTDIRTY);
493 	if (pme & PM_FILE)
494 		flags |= BIT(FILE);
495 	if (pme & PM_SWAP)
496 		flags |= BIT(SWAP);
497 	if (pme & PM_MMAP_EXCLUSIVE)
498 		flags |= BIT(MMAP_EXCLUSIVE);
499 
500 	return flags;
501 }
502 
503 static uint64_t well_known_flags(uint64_t flags)
504 {
505 	/* hide flags intended only for kernel hacker */
506 	flags &= ~KPF_HACKERS_BITS;
507 
508 	/* hide non-hugeTLB compound pages */
509 	if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
510 		flags &= ~BITS_COMPOUND;
511 
512 	return flags;
513 }
514 
515 static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
516 {
517 	if (opt_raw)
518 		flags = expand_overloaded_flags(flags, pme);
519 	else
520 		flags = well_known_flags(flags);
521 
522 	return flags;
523 }
524 
525 /*
526  * page actions
527  */
528 
529 static void prepare_hwpoison_fd(void)
530 {
531 	char buf[MAX_PATH + 1];
532 
533 	hwpoison_debug_fs = debugfs__mount();
534 	if (!hwpoison_debug_fs) {
535 		perror("mount debugfs");
536 		exit(EXIT_FAILURE);
537 	}
538 
539 	if (opt_hwpoison && !hwpoison_inject_fd) {
540 		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
541 			hwpoison_debug_fs);
542 		hwpoison_inject_fd = checked_open(buf, O_WRONLY);
543 	}
544 
545 	if (opt_unpoison && !hwpoison_forget_fd) {
546 		snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
547 			hwpoison_debug_fs);
548 		hwpoison_forget_fd = checked_open(buf, O_WRONLY);
549 	}
550 }
551 
552 static int hwpoison_page(unsigned long offset)
553 {
554 	char buf[100];
555 	int len;
556 
557 	len = sprintf(buf, "0x%lx\n", offset);
558 	len = write(hwpoison_inject_fd, buf, len);
559 	if (len < 0) {
560 		perror("hwpoison inject");
561 		return len;
562 	}
563 	return 0;
564 }
565 
566 static int unpoison_page(unsigned long offset)
567 {
568 	char buf[100];
569 	int len;
570 
571 	len = sprintf(buf, "0x%lx\n", offset);
572 	len = write(hwpoison_forget_fd, buf, len);
573 	if (len < 0) {
574 		perror("hwpoison forget");
575 		return len;
576 	}
577 	return 0;
578 }
579 
580 static int mark_page_idle(unsigned long offset)
581 {
582 	static unsigned long off;
583 	static uint64_t buf;
584 	int len;
585 
586 	if ((offset / 64 == off / 64) || buf == 0) {
587 		buf |= 1UL << (offset % 64);
588 		off = offset;
589 		return 0;
590 	}
591 
592 	len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
593 	if (len < 0) {
594 		perror("mark page idle");
595 		return len;
596 	}
597 
598 	buf = 1UL << (offset % 64);
599 	off = offset;
600 
601 	return 0;
602 }
603 
604 /*
605  * page frame walker
606  */
607 
608 static size_t hash_slot(uint64_t flags)
609 {
610 	size_t k = HASH_KEY(flags);
611 	size_t i;
612 
613 	/* Explicitly reserve slot 0 for flags 0: the following logic
614 	 * cannot distinguish an unoccupied slot from slot (flags==0).
615 	 */
616 	if (flags == 0)
617 		return 0;
618 
619 	/* search through the remaining (HASH_SIZE-1) slots */
620 	for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
621 		if (!k || k >= ARRAY_SIZE(page_flags))
622 			k = 1;
623 		if (page_flags[k] == 0) {
624 			page_flags[k] = flags;
625 			return k;
626 		}
627 		if (page_flags[k] == flags)
628 			return k;
629 	}
630 
631 	fatal("hash table full: bump up HASH_SHIFT?\n");
632 	exit(EXIT_FAILURE);
633 }
634 
635 static void add_page(unsigned long voffset, unsigned long offset,
636 		     uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
637 		     uint64_t pme)
638 {
639 	flags = kpageflags_flags(flags, pme);
640 
641 	if (!bit_mask_ok(flags))
642 		return;
643 
644 	if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
645 		return;
646 
647 	if (opt_hwpoison)
648 		hwpoison_page(offset);
649 	if (opt_unpoison)
650 		unpoison_page(offset);
651 
652 	if (opt_mark_idle)
653 		mark_page_idle(offset);
654 
655 	if (opt_list == 1)
656 		show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
657 	else if (opt_list == 2)
658 		show_page(voffset, offset, flags, cgroup, mapcnt);
659 
660 	nr_pages[hash_slot(flags)]++;
661 	total_pages++;
662 }
663 
664 #define KPAGEFLAGS_BATCH	(64 << 10)	/* 64k pages */
665 static void walk_pfn(unsigned long voffset,
666 		     unsigned long index,
667 		     unsigned long count,
668 		     uint64_t pme)
669 {
670 	uint64_t buf[KPAGEFLAGS_BATCH];
671 	uint64_t cgi[KPAGEFLAGS_BATCH];
672 	uint64_t cnt[KPAGEFLAGS_BATCH];
673 	unsigned long batch;
674 	unsigned long pages;
675 	unsigned long i;
676 
677 	/*
678 	 * kpagecgroup_read() reads only if kpagecgroup were opened, but
679 	 * /proc/kpagecgroup might even not exist, so it's better to fill
680 	 * them with zeros here.
681 	 */
682 	if (count == 1)
683 		cgi[0] = 0;
684 	else
685 		memset(cgi, 0, sizeof cgi);
686 
687 	while (count) {
688 		batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
689 		pages = kpageflags_read(buf, index, batch);
690 		if (pages == 0)
691 			break;
692 
693 		if (kpagecgroup_read(cgi, index, pages) != pages)
694 			fatal("kpagecgroup returned fewer pages than expected");
695 
696 		if (kpagecount_read(cnt, index, pages) != pages)
697 			fatal("kpagecount returned fewer pages than expected");
698 
699 		for (i = 0; i < pages; i++)
700 			add_page(voffset + i, index + i,
701 				 buf[i], cgi[i], cnt[i], pme);
702 
703 		index += pages;
704 		count -= pages;
705 	}
706 }
707 
708 static void walk_swap(unsigned long voffset, uint64_t pme)
709 {
710 	uint64_t flags = kpageflags_flags(0, pme);
711 
712 	if (!bit_mask_ok(flags))
713 		return;
714 
715 	if (opt_cgroup)
716 		return;
717 
718 	if (opt_list == 1)
719 		show_page_range(voffset, pagemap_swap_offset(pme),
720 				1, flags, 0, 0);
721 	else if (opt_list == 2)
722 		show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
723 
724 	nr_pages[hash_slot(flags)]++;
725 	total_pages++;
726 }
727 
728 #define PAGEMAP_BATCH	(64 << 10)
729 static void walk_vma(unsigned long index, unsigned long count)
730 {
731 	uint64_t buf[PAGEMAP_BATCH];
732 	unsigned long batch;
733 	unsigned long pages;
734 	unsigned long pfn;
735 	unsigned long i;
736 
737 	while (count) {
738 		batch = min_t(unsigned long, count, PAGEMAP_BATCH);
739 		pages = pagemap_read(buf, index, batch);
740 		if (pages == 0)
741 			break;
742 
743 		for (i = 0; i < pages; i++) {
744 			pfn = pagemap_pfn(buf[i]);
745 			if (pfn)
746 				walk_pfn(index + i, pfn, 1, buf[i]);
747 			if (buf[i] & PM_SWAP)
748 				walk_swap(index + i, buf[i]);
749 		}
750 
751 		index += pages;
752 		count -= pages;
753 	}
754 }
755 
756 static void walk_task(unsigned long index, unsigned long count)
757 {
758 	const unsigned long end = index + count;
759 	unsigned long start;
760 	int i = 0;
761 
762 	while (index < end) {
763 
764 		while (pg_end[i] <= index)
765 			if (++i >= nr_vmas)
766 				return;
767 		if (pg_start[i] >= end)
768 			return;
769 
770 		start = max_t(unsigned long, pg_start[i], index);
771 		index = min_t(unsigned long, pg_end[i], end);
772 
773 		assert(start < index);
774 		walk_vma(start, index - start);
775 	}
776 }
777 
778 static void add_addr_range(unsigned long offset, unsigned long size)
779 {
780 	if (nr_addr_ranges >= MAX_ADDR_RANGES)
781 		fatal("too many addr ranges\n");
782 
783 	opt_offset[nr_addr_ranges] = offset;
784 	opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
785 	nr_addr_ranges++;
786 }
787 
788 static void walk_addr_ranges(void)
789 {
790 	int i;
791 
792 	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
793 
794 	if (!nr_addr_ranges)
795 		add_addr_range(0, ULONG_MAX);
796 
797 	for (i = 0; i < nr_addr_ranges; i++)
798 		if (!opt_pid)
799 			walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
800 		else
801 			walk_task(opt_offset[i], opt_size[i]);
802 
803 	if (opt_mark_idle)
804 		mark_page_idle(0);
805 
806 	close(kpageflags_fd);
807 }
808 
809 
810 /*
811  * user interface
812  */
813 
814 static const char *page_flag_type(uint64_t flag)
815 {
816 	if (flag & KPF_HACKERS_BITS)
817 		return "(r)";
818 	if (flag & KPF_OVERLOADED_BITS)
819 		return "(o)";
820 	return "   ";
821 }
822 
823 static void usage(void)
824 {
825 	size_t i, j;
826 
827 	printf(
828 "page-types [options]\n"
829 "            -r|--raw                   Raw mode, for kernel developers\n"
830 "            -d|--describe flags        Describe flags\n"
831 "            -a|--addr    addr-spec     Walk a range of pages\n"
832 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
833 "            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
834 "            -p|--pid     pid           Walk process address space\n"
835 "            -f|--file    filename      Walk file address space\n"
836 "            -i|--mark-idle             Mark pages idle\n"
837 "            -l|--list                  Show page details in ranges\n"
838 "            -L|--list-each             Show page details one by one\n"
839 "            -C|--list-cgroup           Show cgroup inode for pages\n"
840 "            -M|--list-mapcnt           Show page map count\n"
841 "            -N|--no-summary            Don't show summary info\n"
842 "            -X|--hwpoison              hwpoison pages\n"
843 "            -x|--unpoison              unpoison pages\n"
844 "            -F|--kpageflags filename   kpageflags file to parse\n"
845 "            -h|--help                  Show this usage message\n"
846 "flags:\n"
847 "            0x10                       bitfield format, e.g.\n"
848 "            anon                       bit-name, e.g.\n"
849 "            0x10,anon                  comma-separated list, e.g.\n"
850 "addr-spec:\n"
851 "            N                          one page at offset N (unit: pages)\n"
852 "            N+M                        pages range from N to N+M-1\n"
853 "            N,M                        pages range from N to M-1\n"
854 "            N,                         pages range from N to end\n"
855 "            ,M                         pages range from 0 to M-1\n"
856 "bits-spec:\n"
857 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
858 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
859 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
860 "            =bit1,bit2                 flags == (bit1|bit2)\n"
861 "bit-names:\n"
862 	);
863 
864 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
865 		if (!page_flag_names[i])
866 			continue;
867 		printf("%16s%s", page_flag_names[i] + 2,
868 				 page_flag_type(1ULL << i));
869 		if (++j > 3) {
870 			j = 0;
871 			putchar('\n');
872 		}
873 	}
874 	printf("\n                                   "
875 		"(r) raw mode bits  (o) overloaded bits\n");
876 }
877 
878 static unsigned long long parse_number(const char *str)
879 {
880 	unsigned long long n;
881 
882 	n = strtoll(str, NULL, 0);
883 
884 	if (n == 0 && str[0] != '0')
885 		fatal("invalid name or number: %s\n", str);
886 
887 	return n;
888 }
889 
890 static void parse_pid(const char *str)
891 {
892 	FILE *file;
893 	char buf[5000];
894 
895 	opt_pid = parse_number(str);
896 
897 	sprintf(buf, "/proc/%d/pagemap", opt_pid);
898 	pagemap_fd = checked_open(buf, O_RDONLY);
899 
900 	sprintf(buf, "/proc/%d/maps", opt_pid);
901 	file = fopen(buf, "r");
902 	if (!file) {
903 		perror(buf);
904 		exit(EXIT_FAILURE);
905 	}
906 
907 	while (fgets(buf, sizeof(buf), file) != NULL) {
908 		unsigned long vm_start;
909 		unsigned long vm_end;
910 		unsigned long long pgoff;
911 		int major, minor;
912 		char r, w, x, s;
913 		unsigned long ino;
914 		int n;
915 
916 		n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
917 			   &vm_start,
918 			   &vm_end,
919 			   &r, &w, &x, &s,
920 			   &pgoff,
921 			   &major, &minor,
922 			   &ino);
923 		if (n < 10) {
924 			fprintf(stderr, "unexpected line: %s\n", buf);
925 			continue;
926 		}
927 		pg_start[nr_vmas] = vm_start / page_size;
928 		pg_end[nr_vmas] = vm_end / page_size;
929 		if (++nr_vmas >= MAX_VMAS) {
930 			fprintf(stderr, "too many VMAs\n");
931 			break;
932 		}
933 	}
934 	fclose(file);
935 }
936 
937 static void show_file(const char *name, const struct stat *st)
938 {
939 	unsigned long long size = st->st_size;
940 	char atime[64], mtime[64];
941 	long now = time(NULL);
942 
943 	printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
944 			name, (unsigned)st->st_ino,
945 			size, (size + page_size - 1) / page_size);
946 
947 	strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
948 	strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
949 
950 	printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
951 			mtime, now - st->st_mtime,
952 			atime, now - st->st_atime);
953 }
954 
955 static sigjmp_buf sigbus_jmp;
956 
957 static void * volatile sigbus_addr;
958 
959 static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
960 {
961 	(void)sig;
962 	(void)ucontex;
963 	sigbus_addr = info ? info->si_addr : NULL;
964 	siglongjmp(sigbus_jmp, 1);
965 }
966 
967 static struct sigaction sigbus_action = {
968 	.sa_sigaction = sigbus_handler,
969 	.sa_flags = SA_SIGINFO,
970 };
971 
972 static void walk_file_range(const char *name, int fd,
973 			    unsigned long off, unsigned long end)
974 {
975 	uint8_t vec[PAGEMAP_BATCH];
976 	uint64_t buf[PAGEMAP_BATCH], flags;
977 	uint64_t cgroup = 0;
978 	uint64_t mapcnt = 0;
979 	unsigned long nr_pages, pfn, i;
980 	ssize_t len;
981 	void *ptr;
982 	int first = 1;
983 
984 	for (; off < end; off += len) {
985 		nr_pages = (end - off + page_size - 1) / page_size;
986 		if (nr_pages > PAGEMAP_BATCH)
987 			nr_pages = PAGEMAP_BATCH;
988 		len = nr_pages * page_size;
989 
990 		ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
991 		if (ptr == MAP_FAILED)
992 			fatal("mmap failed: %s", name);
993 
994 		/* determine cached pages */
995 		if (mincore(ptr, len, vec))
996 			fatal("mincore failed: %s", name);
997 
998 		/* turn off readahead */
999 		if (madvise(ptr, len, MADV_RANDOM))
1000 			fatal("madvice failed: %s", name);
1001 
1002 		if (sigsetjmp(sigbus_jmp, 1)) {
1003 			end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1004 			fprintf(stderr, "got sigbus at offset %lld: %s\n",
1005 					(long long)end, name);
1006 			goto got_sigbus;
1007 		}
1008 
1009 		/* populate ptes */
1010 		for (i = 0; i < nr_pages ; i++) {
1011 			if (vec[i] & 1)
1012 				(void)*(volatile int *)(ptr + i * page_size);
1013 		}
1014 got_sigbus:
1015 
1016 		/* turn off harvesting reference bits */
1017 		if (madvise(ptr, len, MADV_SEQUENTIAL))
1018 			fatal("madvice failed: %s", name);
1019 
1020 		if (pagemap_read(buf, (unsigned long)ptr / page_size,
1021 					nr_pages) != nr_pages)
1022 			fatal("cannot read pagemap");
1023 
1024 		munmap(ptr, len);
1025 
1026 		for (i = 0; i < nr_pages; i++) {
1027 			pfn = pagemap_pfn(buf[i]);
1028 			if (!pfn)
1029 				continue;
1030 			if (!kpageflags_read(&flags, pfn, 1))
1031 				continue;
1032 			if (!kpagecgroup_read(&cgroup, pfn, 1))
1033 				fatal("kpagecgroup_read failed");
1034 			if (!kpagecount_read(&mapcnt, pfn, 1))
1035 				fatal("kpagecount_read failed");
1036 			if (first && opt_list) {
1037 				first = 0;
1038 				flush_page_range();
1039 			}
1040 			add_page(off / page_size + i, pfn,
1041 				 flags, cgroup, mapcnt, buf[i]);
1042 		}
1043 	}
1044 }
1045 
1046 static void walk_file(const char *name, const struct stat *st)
1047 {
1048 	int i;
1049 	int fd;
1050 
1051 	fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
1052 
1053 	if (!nr_addr_ranges)
1054 		add_addr_range(0, st->st_size / page_size);
1055 
1056 	for (i = 0; i < nr_addr_ranges; i++)
1057 		walk_file_range(name, fd, opt_offset[i] * page_size,
1058 				(opt_offset[i] + opt_size[i]) * page_size);
1059 
1060 	close(fd);
1061 }
1062 
1063 int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1064 {
1065 	(void)f;
1066 	switch (type) {
1067 	case FTW_F:
1068 		if (S_ISREG(st->st_mode))
1069 			walk_file(name, st);
1070 		break;
1071 	case FTW_DNR:
1072 		fprintf(stderr, "cannot read dir: %s\n", name);
1073 		break;
1074 	}
1075 	return 0;
1076 }
1077 
1078 struct stat st;
1079 
1080 static void walk_page_cache(void)
1081 {
1082 	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1083 	pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1084 	sigaction(SIGBUS, &sigbus_action, NULL);
1085 
1086 	if (stat(opt_file, &st))
1087 		fatal("stat failed: %s\n", opt_file);
1088 
1089 	if (S_ISREG(st.st_mode)) {
1090 		walk_file(opt_file, &st);
1091 	} else if (S_ISDIR(st.st_mode)) {
1092 		/* do not follow symlinks and mountpoints */
1093 		if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1094 			fatal("nftw failed: %s\n", opt_file);
1095 	} else
1096 		fatal("unhandled file type: %s\n", opt_file);
1097 
1098 	close(kpageflags_fd);
1099 	close(pagemap_fd);
1100 	signal(SIGBUS, SIG_DFL);
1101 }
1102 
1103 static void parse_file(const char *name)
1104 {
1105 	opt_file = name;
1106 }
1107 
1108 static void parse_cgroup(const char *path)
1109 {
1110 	if (path[0] == '@') {
1111 		opt_cgroup = parse_number(path + 1);
1112 		return;
1113 	}
1114 
1115 	struct stat st;
1116 
1117 	if (stat(path, &st))
1118 		fatal("stat failed: %s: %m\n", path);
1119 
1120 	if (!S_ISDIR(st.st_mode))
1121 		fatal("cgroup supposed to be a directory: %s\n", path);
1122 
1123 	opt_cgroup = st.st_ino;
1124 }
1125 
1126 static void parse_addr_range(const char *optarg)
1127 {
1128 	unsigned long offset;
1129 	unsigned long size;
1130 	char *p;
1131 
1132 	p = strchr(optarg, ',');
1133 	if (!p)
1134 		p = strchr(optarg, '+');
1135 
1136 	if (p == optarg) {
1137 		offset = 0;
1138 		size   = parse_number(p + 1);
1139 	} else if (p) {
1140 		offset = parse_number(optarg);
1141 		if (p[1] == '\0')
1142 			size = ULONG_MAX;
1143 		else {
1144 			size = parse_number(p + 1);
1145 			if (*p == ',') {
1146 				if (size < offset)
1147 					fatal("invalid range: %lu,%lu\n",
1148 							offset, size);
1149 				size -= offset;
1150 			}
1151 		}
1152 	} else {
1153 		offset = parse_number(optarg);
1154 		size   = 1;
1155 	}
1156 
1157 	add_addr_range(offset, size);
1158 }
1159 
1160 static void add_bits_filter(uint64_t mask, uint64_t bits)
1161 {
1162 	if (nr_bit_filters >= MAX_BIT_FILTERS)
1163 		fatal("too much bit filters\n");
1164 
1165 	opt_mask[nr_bit_filters] = mask;
1166 	opt_bits[nr_bit_filters] = bits;
1167 	nr_bit_filters++;
1168 }
1169 
1170 static uint64_t parse_flag_name(const char *str, int len)
1171 {
1172 	size_t i;
1173 
1174 	if (!*str || !len)
1175 		return 0;
1176 
1177 	if (len <= 8 && !strncmp(str, "compound", len))
1178 		return BITS_COMPOUND;
1179 
1180 	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1181 		if (!page_flag_names[i])
1182 			continue;
1183 		if (!strncmp(str, page_flag_names[i] + 2, len))
1184 			return 1ULL << i;
1185 	}
1186 
1187 	return parse_number(str);
1188 }
1189 
1190 static uint64_t parse_flag_names(const char *str, int all)
1191 {
1192 	const char *p    = str;
1193 	uint64_t   flags = 0;
1194 
1195 	while (1) {
1196 		if (*p == ',' || *p == '=' || *p == '\0') {
1197 			if ((*str != '~') || (*str == '~' && all && *++str))
1198 				flags |= parse_flag_name(str, p - str);
1199 			if (*p != ',')
1200 				break;
1201 			str = p + 1;
1202 		}
1203 		p++;
1204 	}
1205 
1206 	return flags;
1207 }
1208 
1209 static void parse_bits_mask(const char *optarg)
1210 {
1211 	uint64_t mask;
1212 	uint64_t bits;
1213 	const char *p;
1214 
1215 	p = strchr(optarg, '=');
1216 	if (p == optarg) {
1217 		mask = KPF_ALL_BITS;
1218 		bits = parse_flag_names(p + 1, 0);
1219 	} else if (p) {
1220 		mask = parse_flag_names(optarg, 0);
1221 		bits = parse_flag_names(p + 1, 0);
1222 	} else if (strchr(optarg, '~')) {
1223 		mask = parse_flag_names(optarg, 1);
1224 		bits = parse_flag_names(optarg, 0);
1225 	} else {
1226 		mask = parse_flag_names(optarg, 0);
1227 		bits = KPF_ALL_BITS;
1228 	}
1229 
1230 	add_bits_filter(mask, bits);
1231 }
1232 
1233 static void parse_kpageflags(const char *name)
1234 {
1235 	opt_kpageflags = name;
1236 }
1237 
1238 static void describe_flags(const char *optarg)
1239 {
1240 	uint64_t flags = parse_flag_names(optarg, 0);
1241 
1242 	printf("0x%016llx\t%s\t%s\n",
1243 		(unsigned long long)flags,
1244 		page_flag_name(flags),
1245 		page_flag_longname(flags));
1246 }
1247 
1248 static const struct option opts[] = {
1249 	{ "raw"       , 0, NULL, 'r' },
1250 	{ "pid"       , 1, NULL, 'p' },
1251 	{ "file"      , 1, NULL, 'f' },
1252 	{ "addr"      , 1, NULL, 'a' },
1253 	{ "bits"      , 1, NULL, 'b' },
1254 	{ "cgroup"    , 1, NULL, 'c' },
1255 	{ "describe"  , 1, NULL, 'd' },
1256 	{ "mark-idle" , 0, NULL, 'i' },
1257 	{ "list"      , 0, NULL, 'l' },
1258 	{ "list-each" , 0, NULL, 'L' },
1259 	{ "list-cgroup", 0, NULL, 'C' },
1260 	{ "list-mapcnt", 0, NULL, 'M' },
1261 	{ "no-summary", 0, NULL, 'N' },
1262 	{ "hwpoison"  , 0, NULL, 'X' },
1263 	{ "unpoison"  , 0, NULL, 'x' },
1264 	{ "kpageflags", 0, NULL, 'F' },
1265 	{ "help"      , 0, NULL, 'h' },
1266 	{ NULL        , 0, NULL, 0 }
1267 };
1268 
1269 int main(int argc, char *argv[])
1270 {
1271 	int c;
1272 
1273 	page_size = getpagesize();
1274 
1275 	while ((c = getopt_long(argc, argv,
1276 				"rp:f:a:b:d:c:CilLMNXxF:h",
1277 				opts, NULL)) != -1) {
1278 		switch (c) {
1279 		case 'r':
1280 			opt_raw = 1;
1281 			break;
1282 		case 'p':
1283 			parse_pid(optarg);
1284 			break;
1285 		case 'f':
1286 			parse_file(optarg);
1287 			break;
1288 		case 'a':
1289 			parse_addr_range(optarg);
1290 			break;
1291 		case 'b':
1292 			parse_bits_mask(optarg);
1293 			break;
1294 		case 'c':
1295 			parse_cgroup(optarg);
1296 			break;
1297 		case 'C':
1298 			opt_list_cgroup = 1;
1299 			break;
1300 		case 'd':
1301 			describe_flags(optarg);
1302 			exit(0);
1303 		case 'i':
1304 			opt_mark_idle = 1;
1305 			break;
1306 		case 'l':
1307 			opt_list = 1;
1308 			break;
1309 		case 'L':
1310 			opt_list = 2;
1311 			break;
1312 		case 'M':
1313 			opt_list_mapcnt = 1;
1314 			break;
1315 		case 'N':
1316 			opt_no_summary = 1;
1317 			break;
1318 		case 'X':
1319 			opt_hwpoison = 1;
1320 			prepare_hwpoison_fd();
1321 			break;
1322 		case 'x':
1323 			opt_unpoison = 1;
1324 			prepare_hwpoison_fd();
1325 			break;
1326 		case 'F':
1327 			parse_kpageflags(optarg);
1328 			break;
1329 		case 'h':
1330 			usage();
1331 			exit(0);
1332 		default:
1333 			usage();
1334 			exit(1);
1335 		}
1336 	}
1337 
1338 	if (!opt_kpageflags)
1339 		opt_kpageflags = PROC_KPAGEFLAGS;
1340 
1341 	if (opt_cgroup || opt_list_cgroup)
1342 		kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1343 
1344 	if (opt_list && opt_list_mapcnt)
1345 		kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1346 
1347 	if (opt_mark_idle)
1348 		page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1349 
1350 	if (opt_list && opt_pid)
1351 		printf("voffset\t");
1352 	if (opt_list && opt_file)
1353 		printf("foffset\t");
1354 	if (opt_list && opt_list_cgroup)
1355 		printf("cgroup\t");
1356 	if (opt_list && opt_list_mapcnt)
1357 		printf("map-cnt\t");
1358 
1359 	if (opt_list == 1)
1360 		printf("offset\tlen\tflags\n");
1361 	if (opt_list == 2)
1362 		printf("offset\tflags\n");
1363 
1364 	if (opt_file)
1365 		walk_page_cache();
1366 	else
1367 		walk_addr_ranges();
1368 
1369 	if (opt_list == 1)
1370 		flush_page_range();
1371 
1372 	if (opt_no_summary)
1373 		return 0;
1374 
1375 	if (opt_list)
1376 		printf("\n\n");
1377 
1378 	if (opt_file) {
1379 		show_file(opt_file, &st);
1380 		printf("\n");
1381 	}
1382 
1383 	show_summary();
1384 
1385 	if (opt_list_mapcnt)
1386 		close(kpagecount_fd);
1387 
1388 	if (page_idle_fd >= 0)
1389 		close(page_idle_fd);
1390 
1391 	return 0;
1392 }
1393