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
100static 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
156static int		opt_raw;	/* for kernel developers */
157static int		opt_list;	/* list pages (in ranges) */
158static int		opt_mark_idle;	/* set accessed bit */
159static int		opt_no_summary;	/* don't show summary */
160static pid_t		opt_pid;	/* process to walk */
161const char		*opt_file;	/* file or directory path */
162static uint64_t		opt_cgroup;	/* cgroup inode */
163static int		opt_list_cgroup;/* list page cgroup */
164static int		opt_list_mapcnt;/* list page map count */
165static const char	*opt_kpageflags;/* kpageflags file to parse */
166
167#define MAX_ADDR_RANGES	1024
168static int		nr_addr_ranges;
169static unsigned long	opt_offset[MAX_ADDR_RANGES];
170static unsigned long	opt_size[MAX_ADDR_RANGES];
171
172#define MAX_VMAS	10240
173static int		nr_vmas;
174static unsigned long	pg_start[MAX_VMAS];
175static unsigned long	pg_end[MAX_VMAS];
176
177#define MAX_BIT_FILTERS	64
178static int		nr_bit_filters;
179static uint64_t		opt_mask[MAX_BIT_FILTERS];
180static uint64_t		opt_bits[MAX_BIT_FILTERS];
181
182static int		page_size;
183
184static int		pagemap_fd;
185static int		kpageflags_fd;
186static int		kpagecount_fd = -1;
187static int		kpagecgroup_fd = -1;
188static int		page_idle_fd = -1;
189
190static int		opt_hwpoison;
191static int		opt_unpoison;
192
193static const char	*hwpoison_debug_fs;
194static int		hwpoison_inject_fd;
195static 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
202static unsigned long	total_pages;
203static unsigned long	nr_pages[HASH_SIZE];
204static 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
223static unsigned long pages2mb(unsigned long pages)
224{
225	return (pages * page_size) >> 20;
226}
227
228static 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
238static 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
254static 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
275static 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
282static 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
292static 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
301static 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
308static 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
320static 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
329static 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
348static 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
372static 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
410static void flush_page_range(void)
411{
412	show_page_range(0, 0, 0, 0, 0, 0);
413}
414
415static 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
430static 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
456static 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
473static 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
503static 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
515static 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
529static 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
552static 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
566static 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
580static 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
608static 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
635static 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 */
665static 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
708static 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)
729static 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
756static 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
778static 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
788static 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
814static 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
823static 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
878static 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
890static 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
937static 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
955static sigjmp_buf sigbus_jmp;
956
957static void * volatile sigbus_addr;
958
959static 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
967static struct sigaction sigbus_action = {
968	.sa_sigaction = sigbus_handler,
969	.sa_flags = SA_SIGINFO,
970};
971
972static 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		}
1014got_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
1046static 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
1063int 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
1078struct stat st;
1079
1080static 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
1103static void parse_file(const char *name)
1104{
1105	opt_file = name;
1106}
1107
1108static 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
1126static 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
1160static 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
1170static 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
1190static 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
1209static 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
1233static void parse_kpageflags(const char *name)
1234{
1235	opt_kpageflags = name;
1236}
1237
1238static 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
1248static 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
1269int 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