1 /*
2  * page-types: Tool for querying page flags
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the Free
6  * Software Foundation; version 2.
7  *
8  * This program is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should find a copy of v2 of the GNU General Public License somewhere on
14  * your Linux system; if not, write to the Free Software Foundation, Inc., 59
15  * Temple Place, Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Copyright (C) 2009 Intel corporation
18  *
19  * Authors: Wu Fengguang <fengguang.wu@intel.com>
20  */
21 
22 #define _LARGEFILE64_SOURCE
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <stdint.h>
27 #include <stdarg.h>
28 #include <string.h>
29 #include <getopt.h>
30 #include <limits.h>
31 #include <assert.h>
32 #include <sys/types.h>
33 #include <sys/errno.h>
34 #include <sys/fcntl.h>
35 #include <sys/mount.h>
36 #include <sys/statfs.h>
37 #include "../../include/linux/magic.h"
38 
39 
40 #ifndef MAX_PATH
41 # define MAX_PATH 256
42 #endif
43 
44 #ifndef STR
45 # define _STR(x) #x
46 # define STR(x) _STR(x)
47 #endif
48 
49 /*
50  * pagemap kernel ABI bits
51  */
52 
53 #define PM_ENTRY_BYTES      sizeof(uint64_t)
54 #define PM_STATUS_BITS      3
55 #define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
56 #define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
57 #define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
58 #define PM_PSHIFT_BITS      6
59 #define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
60 #define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
61 #define PM_PSHIFT(x)        (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
62 #define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
63 #define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
64 
65 #define PM_PRESENT          PM_STATUS(4LL)
66 #define PM_SWAP             PM_STATUS(2LL)
67 
68 
69 /*
70  * kernel page flags
71  */
72 
73 #define KPF_BYTES		8
74 #define PROC_KPAGEFLAGS		"/proc/kpageflags"
75 
76 /* copied from kpageflags_read() */
77 #define KPF_LOCKED		0
78 #define KPF_ERROR		1
79 #define KPF_REFERENCED		2
80 #define KPF_UPTODATE		3
81 #define KPF_DIRTY		4
82 #define KPF_LRU			5
83 #define KPF_ACTIVE		6
84 #define KPF_SLAB		7
85 #define KPF_WRITEBACK		8
86 #define KPF_RECLAIM		9
87 #define KPF_BUDDY		10
88 
89 /* [11-20] new additions in 2.6.31 */
90 #define KPF_MMAP		11
91 #define KPF_ANON		12
92 #define KPF_SWAPCACHE		13
93 #define KPF_SWAPBACKED		14
94 #define KPF_COMPOUND_HEAD	15
95 #define KPF_COMPOUND_TAIL	16
96 #define KPF_HUGE		17
97 #define KPF_UNEVICTABLE		18
98 #define KPF_HWPOISON		19
99 #define KPF_NOPAGE		20
100 #define KPF_KSM			21
101 
102 /* [32-] kernel hacking assistances */
103 #define KPF_RESERVED		32
104 #define KPF_MLOCKED		33
105 #define KPF_MAPPEDTODISK	34
106 #define KPF_PRIVATE		35
107 #define KPF_PRIVATE_2		36
108 #define KPF_OWNER_PRIVATE	37
109 #define KPF_ARCH		38
110 #define KPF_UNCACHED		39
111 
112 /* [48-] take some arbitrary free slots for expanding overloaded flags
113  * not part of kernel API
114  */
115 #define KPF_READAHEAD		48
116 #define KPF_SLOB_FREE		49
117 #define KPF_SLUB_FROZEN		50
118 #define KPF_SLUB_DEBUG		51
119 
120 #define KPF_ALL_BITS		((uint64_t)~0ULL)
121 #define KPF_HACKERS_BITS	(0xffffULL << 32)
122 #define KPF_OVERLOADED_BITS	(0xffffULL << 48)
123 #define BIT(name)		(1ULL << KPF_##name)
124 #define BITS_COMPOUND		(BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
125 
126 static const char *page_flag_names[] = {
127 	[KPF_LOCKED]		= "L:locked",
128 	[KPF_ERROR]		= "E:error",
129 	[KPF_REFERENCED]	= "R:referenced",
130 	[KPF_UPTODATE]		= "U:uptodate",
131 	[KPF_DIRTY]		= "D:dirty",
132 	[KPF_LRU]		= "l:lru",
133 	[KPF_ACTIVE]		= "A:active",
134 	[KPF_SLAB]		= "S:slab",
135 	[KPF_WRITEBACK]		= "W:writeback",
136 	[KPF_RECLAIM]		= "I:reclaim",
137 	[KPF_BUDDY]		= "B:buddy",
138 
139 	[KPF_MMAP]		= "M:mmap",
140 	[KPF_ANON]		= "a:anonymous",
141 	[KPF_SWAPCACHE]		= "s:swapcache",
142 	[KPF_SWAPBACKED]	= "b:swapbacked",
143 	[KPF_COMPOUND_HEAD]	= "H:compound_head",
144 	[KPF_COMPOUND_TAIL]	= "T:compound_tail",
145 	[KPF_HUGE]		= "G:huge",
146 	[KPF_UNEVICTABLE]	= "u:unevictable",
147 	[KPF_HWPOISON]		= "X:hwpoison",
148 	[KPF_NOPAGE]		= "n:nopage",
149 	[KPF_KSM]		= "x:ksm",
150 
151 	[KPF_RESERVED]		= "r:reserved",
152 	[KPF_MLOCKED]		= "m:mlocked",
153 	[KPF_MAPPEDTODISK]	= "d:mappedtodisk",
154 	[KPF_PRIVATE]		= "P:private",
155 	[KPF_PRIVATE_2]		= "p:private_2",
156 	[KPF_OWNER_PRIVATE]	= "O:owner_private",
157 	[KPF_ARCH]		= "h:arch",
158 	[KPF_UNCACHED]		= "c:uncached",
159 
160 	[KPF_READAHEAD]		= "I:readahead",
161 	[KPF_SLOB_FREE]		= "P:slob_free",
162 	[KPF_SLUB_FROZEN]	= "A:slub_frozen",
163 	[KPF_SLUB_DEBUG]	= "E:slub_debug",
164 };
165 
166 
167 static const char *debugfs_known_mountpoints[] = {
168 	"/sys/kernel/debug",
169 	"/debug",
170 	0,
171 };
172 
173 /*
174  * data structures
175  */
176 
177 static int		opt_raw;	/* for kernel developers */
178 static int		opt_list;	/* list pages (in ranges) */
179 static int		opt_no_summary;	/* don't show summary */
180 static pid_t		opt_pid;	/* process to walk */
181 
182 #define MAX_ADDR_RANGES	1024
183 static int		nr_addr_ranges;
184 static unsigned long	opt_offset[MAX_ADDR_RANGES];
185 static unsigned long	opt_size[MAX_ADDR_RANGES];
186 
187 #define MAX_VMAS	10240
188 static int		nr_vmas;
189 static unsigned long	pg_start[MAX_VMAS];
190 static unsigned long	pg_end[MAX_VMAS];
191 
192 #define MAX_BIT_FILTERS	64
193 static int		nr_bit_filters;
194 static uint64_t		opt_mask[MAX_BIT_FILTERS];
195 static uint64_t		opt_bits[MAX_BIT_FILTERS];
196 
197 static int		page_size;
198 
199 static int		pagemap_fd;
200 static int		kpageflags_fd;
201 
202 static int		opt_hwpoison;
203 static int		opt_unpoison;
204 
205 static char		hwpoison_debug_fs[MAX_PATH+1];
206 static int		hwpoison_inject_fd;
207 static int		hwpoison_forget_fd;
208 
209 #define HASH_SHIFT	13
210 #define HASH_SIZE	(1 << HASH_SHIFT)
211 #define HASH_MASK	(HASH_SIZE - 1)
212 #define HASH_KEY(flags)	(flags & HASH_MASK)
213 
214 static unsigned long	total_pages;
215 static unsigned long	nr_pages[HASH_SIZE];
216 static uint64_t 	page_flags[HASH_SIZE];
217 
218 
219 /*
220  * helper functions
221  */
222 
223 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
224 
225 #define min_t(type, x, y) ({			\
226 	type __min1 = (x);			\
227 	type __min2 = (y);			\
228 	__min1 < __min2 ? __min1 : __min2; })
229 
230 #define max_t(type, x, y) ({			\
231 	type __max1 = (x);			\
232 	type __max2 = (y);			\
233 	__max1 > __max2 ? __max1 : __max2; })
234 
pages2mb(unsigned long pages)235 static unsigned long pages2mb(unsigned long pages)
236 {
237 	return (pages * page_size) >> 20;
238 }
239 
fatal(const char * x,...)240 static void fatal(const char *x, ...)
241 {
242 	va_list ap;
243 
244 	va_start(ap, x);
245 	vfprintf(stderr, x, ap);
246 	va_end(ap);
247 	exit(EXIT_FAILURE);
248 }
249 
checked_open(const char * pathname,int flags)250 static int checked_open(const char *pathname, int flags)
251 {
252 	int fd = open(pathname, flags);
253 
254 	if (fd < 0) {
255 		perror(pathname);
256 		exit(EXIT_FAILURE);
257 	}
258 
259 	return fd;
260 }
261 
262 /*
263  * pagemap/kpageflags routines
264  */
265 
do_u64_read(int fd,char * name,uint64_t * buf,unsigned long index,unsigned long count)266 static unsigned long do_u64_read(int fd, char *name,
267 				 uint64_t *buf,
268 				 unsigned long index,
269 				 unsigned long count)
270 {
271 	long bytes;
272 
273 	if (index > ULONG_MAX / 8)
274 		fatal("index overflow: %lu\n", index);
275 
276 	if (lseek(fd, index * 8, SEEK_SET) < 0) {
277 		perror(name);
278 		exit(EXIT_FAILURE);
279 	}
280 
281 	bytes = read(fd, buf, count * 8);
282 	if (bytes < 0) {
283 		perror(name);
284 		exit(EXIT_FAILURE);
285 	}
286 	if (bytes % 8)
287 		fatal("partial read: %lu bytes\n", bytes);
288 
289 	return bytes / 8;
290 }
291 
kpageflags_read(uint64_t * buf,unsigned long index,unsigned long pages)292 static unsigned long kpageflags_read(uint64_t *buf,
293 				     unsigned long index,
294 				     unsigned long pages)
295 {
296 	return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
297 }
298 
pagemap_read(uint64_t * buf,unsigned long index,unsigned long pages)299 static unsigned long pagemap_read(uint64_t *buf,
300 				  unsigned long index,
301 				  unsigned long pages)
302 {
303 	return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
304 }
305 
pagemap_pfn(uint64_t val)306 static unsigned long pagemap_pfn(uint64_t val)
307 {
308 	unsigned long pfn;
309 
310 	if (val & PM_PRESENT)
311 		pfn = PM_PFRAME(val);
312 	else
313 		pfn = 0;
314 
315 	return pfn;
316 }
317 
318 
319 /*
320  * page flag names
321  */
322 
page_flag_name(uint64_t flags)323 static char *page_flag_name(uint64_t flags)
324 {
325 	static char buf[65];
326 	int present;
327 	int i, j;
328 
329 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
330 		present = (flags >> i) & 1;
331 		if (!page_flag_names[i]) {
332 			if (present)
333 				fatal("unknown flag bit %d\n", i);
334 			continue;
335 		}
336 		buf[j++] = present ? page_flag_names[i][0] : '_';
337 	}
338 
339 	return buf;
340 }
341 
page_flag_longname(uint64_t flags)342 static char *page_flag_longname(uint64_t flags)
343 {
344 	static char buf[1024];
345 	int i, n;
346 
347 	for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
348 		if (!page_flag_names[i])
349 			continue;
350 		if ((flags >> i) & 1)
351 			n += snprintf(buf + n, sizeof(buf) - n, "%s,",
352 					page_flag_names[i] + 2);
353 	}
354 	if (n)
355 		n--;
356 	buf[n] = '\0';
357 
358 	return buf;
359 }
360 
361 
362 /*
363  * page list and summary
364  */
365 
show_page_range(unsigned long voffset,unsigned long offset,uint64_t flags)366 static void show_page_range(unsigned long voffset,
367 			    unsigned long offset, uint64_t flags)
368 {
369 	static uint64_t      flags0;
370 	static unsigned long voff;
371 	static unsigned long index;
372 	static unsigned long count;
373 
374 	if (flags == flags0 && offset == index + count &&
375 	    (!opt_pid || voffset == voff + count)) {
376 		count++;
377 		return;
378 	}
379 
380 	if (count) {
381 		if (opt_pid)
382 			printf("%lx\t", voff);
383 		printf("%lx\t%lx\t%s\n",
384 				index, count, page_flag_name(flags0));
385 	}
386 
387 	flags0 = flags;
388 	index  = offset;
389 	voff   = voffset;
390 	count  = 1;
391 }
392 
show_page(unsigned long voffset,unsigned long offset,uint64_t flags)393 static void show_page(unsigned long voffset,
394 		      unsigned long offset, uint64_t flags)
395 {
396 	if (opt_pid)
397 		printf("%lx\t", voffset);
398 	printf("%lx\t%s\n", offset, page_flag_name(flags));
399 }
400 
show_summary(void)401 static void show_summary(void)
402 {
403 	int i;
404 
405 	printf("             flags\tpage-count       MB"
406 		"  symbolic-flags\t\t\tlong-symbolic-flags\n");
407 
408 	for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
409 		if (nr_pages[i])
410 			printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
411 				(unsigned long long)page_flags[i],
412 				nr_pages[i],
413 				pages2mb(nr_pages[i]),
414 				page_flag_name(page_flags[i]),
415 				page_flag_longname(page_flags[i]));
416 	}
417 
418 	printf("             total\t%10lu %8lu\n",
419 			total_pages, pages2mb(total_pages));
420 }
421 
422 
423 /*
424  * page flag filters
425  */
426 
bit_mask_ok(uint64_t flags)427 static int bit_mask_ok(uint64_t flags)
428 {
429 	int i;
430 
431 	for (i = 0; i < nr_bit_filters; i++) {
432 		if (opt_bits[i] == KPF_ALL_BITS) {
433 			if ((flags & opt_mask[i]) == 0)
434 				return 0;
435 		} else {
436 			if ((flags & opt_mask[i]) != opt_bits[i])
437 				return 0;
438 		}
439 	}
440 
441 	return 1;
442 }
443 
expand_overloaded_flags(uint64_t flags)444 static uint64_t expand_overloaded_flags(uint64_t flags)
445 {
446 	/* SLOB/SLUB overload several page flags */
447 	if (flags & BIT(SLAB)) {
448 		if (flags & BIT(PRIVATE))
449 			flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
450 		if (flags & BIT(ACTIVE))
451 			flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
452 		if (flags & BIT(ERROR))
453 			flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
454 	}
455 
456 	/* PG_reclaim is overloaded as PG_readahead in the read path */
457 	if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
458 		flags ^= BIT(RECLAIM) | BIT(READAHEAD);
459 
460 	return flags;
461 }
462 
well_known_flags(uint64_t flags)463 static uint64_t well_known_flags(uint64_t flags)
464 {
465 	/* hide flags intended only for kernel hacker */
466 	flags &= ~KPF_HACKERS_BITS;
467 
468 	/* hide non-hugeTLB compound pages */
469 	if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
470 		flags &= ~BITS_COMPOUND;
471 
472 	return flags;
473 }
474 
kpageflags_flags(uint64_t flags)475 static uint64_t kpageflags_flags(uint64_t flags)
476 {
477 	flags = expand_overloaded_flags(flags);
478 
479 	if (!opt_raw)
480 		flags = well_known_flags(flags);
481 
482 	return flags;
483 }
484 
485 /* verify that a mountpoint is actually a debugfs instance */
debugfs_valid_mountpoint(const char * debugfs)486 static int debugfs_valid_mountpoint(const char *debugfs)
487 {
488 	struct statfs st_fs;
489 
490 	if (statfs(debugfs, &st_fs) < 0)
491 		return -ENOENT;
492 	else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
493 		return -ENOENT;
494 
495 	return 0;
496 }
497 
498 /* find the path to the mounted debugfs */
debugfs_find_mountpoint(void)499 static const char *debugfs_find_mountpoint(void)
500 {
501 	const char **ptr;
502 	char type[100];
503 	FILE *fp;
504 
505 	ptr = debugfs_known_mountpoints;
506 	while (*ptr) {
507 		if (debugfs_valid_mountpoint(*ptr) == 0) {
508 			strcpy(hwpoison_debug_fs, *ptr);
509 			return hwpoison_debug_fs;
510 		}
511 		ptr++;
512 	}
513 
514 	/* give up and parse /proc/mounts */
515 	fp = fopen("/proc/mounts", "r");
516 	if (fp == NULL)
517 		perror("Can't open /proc/mounts for read");
518 
519 	while (fscanf(fp, "%*s %"
520 		      STR(MAX_PATH)
521 		      "s %99s %*s %*d %*d\n",
522 		      hwpoison_debug_fs, type) == 2) {
523 		if (strcmp(type, "debugfs") == 0)
524 			break;
525 	}
526 	fclose(fp);
527 
528 	if (strcmp(type, "debugfs") != 0)
529 		return NULL;
530 
531 	return hwpoison_debug_fs;
532 }
533 
534 /* mount the debugfs somewhere if it's not mounted */
535 
debugfs_mount(void)536 static void debugfs_mount(void)
537 {
538 	const char **ptr;
539 
540 	/* see if it's already mounted */
541 	if (debugfs_find_mountpoint())
542 		return;
543 
544 	ptr = debugfs_known_mountpoints;
545 	while (*ptr) {
546 		if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
547 			/* save the mountpoint */
548 			strcpy(hwpoison_debug_fs, *ptr);
549 			break;
550 		}
551 		ptr++;
552 	}
553 
554 	if (*ptr == NULL) {
555 		perror("mount debugfs");
556 		exit(EXIT_FAILURE);
557 	}
558 }
559 
560 /*
561  * page actions
562  */
563 
prepare_hwpoison_fd(void)564 static void prepare_hwpoison_fd(void)
565 {
566 	char buf[MAX_PATH + 1];
567 
568 	debugfs_mount();
569 
570 	if (opt_hwpoison && !hwpoison_inject_fd) {
571 		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
572 			hwpoison_debug_fs);
573 		hwpoison_inject_fd = checked_open(buf, O_WRONLY);
574 	}
575 
576 	if (opt_unpoison && !hwpoison_forget_fd) {
577 		snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
578 			hwpoison_debug_fs);
579 		hwpoison_forget_fd = checked_open(buf, O_WRONLY);
580 	}
581 }
582 
hwpoison_page(unsigned long offset)583 static int hwpoison_page(unsigned long offset)
584 {
585 	char buf[100];
586 	int len;
587 
588 	len = sprintf(buf, "0x%lx\n", offset);
589 	len = write(hwpoison_inject_fd, buf, len);
590 	if (len < 0) {
591 		perror("hwpoison inject");
592 		return len;
593 	}
594 	return 0;
595 }
596 
unpoison_page(unsigned long offset)597 static int unpoison_page(unsigned long offset)
598 {
599 	char buf[100];
600 	int len;
601 
602 	len = sprintf(buf, "0x%lx\n", offset);
603 	len = write(hwpoison_forget_fd, buf, len);
604 	if (len < 0) {
605 		perror("hwpoison forget");
606 		return len;
607 	}
608 	return 0;
609 }
610 
611 /*
612  * page frame walker
613  */
614 
hash_slot(uint64_t flags)615 static int hash_slot(uint64_t flags)
616 {
617 	int k = HASH_KEY(flags);
618 	int i;
619 
620 	/* Explicitly reserve slot 0 for flags 0: the following logic
621 	 * cannot distinguish an unoccupied slot from slot (flags==0).
622 	 */
623 	if (flags == 0)
624 		return 0;
625 
626 	/* search through the remaining (HASH_SIZE-1) slots */
627 	for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
628 		if (!k || k >= ARRAY_SIZE(page_flags))
629 			k = 1;
630 		if (page_flags[k] == 0) {
631 			page_flags[k] = flags;
632 			return k;
633 		}
634 		if (page_flags[k] == flags)
635 			return k;
636 	}
637 
638 	fatal("hash table full: bump up HASH_SHIFT?\n");
639 	exit(EXIT_FAILURE);
640 }
641 
add_page(unsigned long voffset,unsigned long offset,uint64_t flags)642 static void add_page(unsigned long voffset,
643 		     unsigned long offset, uint64_t flags)
644 {
645 	flags = kpageflags_flags(flags);
646 
647 	if (!bit_mask_ok(flags))
648 		return;
649 
650 	if (opt_hwpoison)
651 		hwpoison_page(offset);
652 	if (opt_unpoison)
653 		unpoison_page(offset);
654 
655 	if (opt_list == 1)
656 		show_page_range(voffset, offset, flags);
657 	else if (opt_list == 2)
658 		show_page(voffset, offset, flags);
659 
660 	nr_pages[hash_slot(flags)]++;
661 	total_pages++;
662 }
663 
664 #define KPAGEFLAGS_BATCH	(64 << 10)	/* 64k pages */
walk_pfn(unsigned long voffset,unsigned long index,unsigned long count)665 static void walk_pfn(unsigned long voffset,
666 		     unsigned long index,
667 		     unsigned long count)
668 {
669 	uint64_t buf[KPAGEFLAGS_BATCH];
670 	unsigned long batch;
671 	long pages;
672 	unsigned long i;
673 
674 	while (count) {
675 		batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
676 		pages = kpageflags_read(buf, index, batch);
677 		if (pages == 0)
678 			break;
679 
680 		for (i = 0; i < pages; i++)
681 			add_page(voffset + i, index + i, buf[i]);
682 
683 		index += pages;
684 		count -= pages;
685 	}
686 }
687 
688 #define PAGEMAP_BATCH	(64 << 10)
walk_vma(unsigned long index,unsigned long count)689 static void walk_vma(unsigned long index, unsigned long count)
690 {
691 	uint64_t buf[PAGEMAP_BATCH];
692 	unsigned long batch;
693 	unsigned long pages;
694 	unsigned long pfn;
695 	unsigned long i;
696 
697 	while (count) {
698 		batch = min_t(unsigned long, count, PAGEMAP_BATCH);
699 		pages = pagemap_read(buf, index, batch);
700 		if (pages == 0)
701 			break;
702 
703 		for (i = 0; i < pages; i++) {
704 			pfn = pagemap_pfn(buf[i]);
705 			if (pfn)
706 				walk_pfn(index + i, pfn, 1);
707 		}
708 
709 		index += pages;
710 		count -= pages;
711 	}
712 }
713 
walk_task(unsigned long index,unsigned long count)714 static void walk_task(unsigned long index, unsigned long count)
715 {
716 	const unsigned long end = index + count;
717 	unsigned long start;
718 	int i = 0;
719 
720 	while (index < end) {
721 
722 		while (pg_end[i] <= index)
723 			if (++i >= nr_vmas)
724 				return;
725 		if (pg_start[i] >= end)
726 			return;
727 
728 		start = max_t(unsigned long, pg_start[i], index);
729 		index = min_t(unsigned long, pg_end[i], end);
730 
731 		assert(start < index);
732 		walk_vma(start, index - start);
733 	}
734 }
735 
add_addr_range(unsigned long offset,unsigned long size)736 static void add_addr_range(unsigned long offset, unsigned long size)
737 {
738 	if (nr_addr_ranges >= MAX_ADDR_RANGES)
739 		fatal("too many addr ranges\n");
740 
741 	opt_offset[nr_addr_ranges] = offset;
742 	opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
743 	nr_addr_ranges++;
744 }
745 
walk_addr_ranges(void)746 static void walk_addr_ranges(void)
747 {
748 	int i;
749 
750 	kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
751 
752 	if (!nr_addr_ranges)
753 		add_addr_range(0, ULONG_MAX);
754 
755 	for (i = 0; i < nr_addr_ranges; i++)
756 		if (!opt_pid)
757 			walk_pfn(0, opt_offset[i], opt_size[i]);
758 		else
759 			walk_task(opt_offset[i], opt_size[i]);
760 
761 	close(kpageflags_fd);
762 }
763 
764 
765 /*
766  * user interface
767  */
768 
page_flag_type(uint64_t flag)769 static const char *page_flag_type(uint64_t flag)
770 {
771 	if (flag & KPF_HACKERS_BITS)
772 		return "(r)";
773 	if (flag & KPF_OVERLOADED_BITS)
774 		return "(o)";
775 	return "   ";
776 }
777 
usage(void)778 static void usage(void)
779 {
780 	int i, j;
781 
782 	printf(
783 "page-types [options]\n"
784 "            -r|--raw                   Raw mode, for kernel developers\n"
785 "            -d|--describe flags        Describe flags\n"
786 "            -a|--addr    addr-spec     Walk a range of pages\n"
787 "            -b|--bits    bits-spec     Walk pages with specified bits\n"
788 "            -p|--pid     pid           Walk process address space\n"
789 #if 0 /* planned features */
790 "            -f|--file    filename      Walk file address space\n"
791 #endif
792 "            -l|--list                  Show page details in ranges\n"
793 "            -L|--list-each             Show page details one by one\n"
794 "            -N|--no-summary            Don't show summary info\n"
795 "            -X|--hwpoison              hwpoison pages\n"
796 "            -x|--unpoison              unpoison pages\n"
797 "            -h|--help                  Show this usage message\n"
798 "flags:\n"
799 "            0x10                       bitfield format, e.g.\n"
800 "            anon                       bit-name, e.g.\n"
801 "            0x10,anon                  comma-separated list, e.g.\n"
802 "addr-spec:\n"
803 "            N                          one page at offset N (unit: pages)\n"
804 "            N+M                        pages range from N to N+M-1\n"
805 "            N,M                        pages range from N to M-1\n"
806 "            N,                         pages range from N to end\n"
807 "            ,M                         pages range from 0 to M-1\n"
808 "bits-spec:\n"
809 "            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
810 "            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
811 "            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
812 "            =bit1,bit2                 flags == (bit1|bit2)\n"
813 "bit-names:\n"
814 	);
815 
816 	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
817 		if (!page_flag_names[i])
818 			continue;
819 		printf("%16s%s", page_flag_names[i] + 2,
820 				 page_flag_type(1ULL << i));
821 		if (++j > 3) {
822 			j = 0;
823 			putchar('\n');
824 		}
825 	}
826 	printf("\n                                   "
827 		"(r) raw mode bits  (o) overloaded bits\n");
828 }
829 
parse_number(const char * str)830 static unsigned long long parse_number(const char *str)
831 {
832 	unsigned long long n;
833 
834 	n = strtoll(str, NULL, 0);
835 
836 	if (n == 0 && str[0] != '0')
837 		fatal("invalid name or number: %s\n", str);
838 
839 	return n;
840 }
841 
parse_pid(const char * str)842 static void parse_pid(const char *str)
843 {
844 	FILE *file;
845 	char buf[5000];
846 
847 	opt_pid = parse_number(str);
848 
849 	sprintf(buf, "/proc/%d/pagemap", opt_pid);
850 	pagemap_fd = checked_open(buf, O_RDONLY);
851 
852 	sprintf(buf, "/proc/%d/maps", opt_pid);
853 	file = fopen(buf, "r");
854 	if (!file) {
855 		perror(buf);
856 		exit(EXIT_FAILURE);
857 	}
858 
859 	while (fgets(buf, sizeof(buf), file) != NULL) {
860 		unsigned long vm_start;
861 		unsigned long vm_end;
862 		unsigned long long pgoff;
863 		int major, minor;
864 		char r, w, x, s;
865 		unsigned long ino;
866 		int n;
867 
868 		n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
869 			   &vm_start,
870 			   &vm_end,
871 			   &r, &w, &x, &s,
872 			   &pgoff,
873 			   &major, &minor,
874 			   &ino);
875 		if (n < 10) {
876 			fprintf(stderr, "unexpected line: %s\n", buf);
877 			continue;
878 		}
879 		pg_start[nr_vmas] = vm_start / page_size;
880 		pg_end[nr_vmas] = vm_end / page_size;
881 		if (++nr_vmas >= MAX_VMAS) {
882 			fprintf(stderr, "too many VMAs\n");
883 			break;
884 		}
885 	}
886 	fclose(file);
887 }
888 
parse_file(const char * name)889 static void parse_file(const char *name)
890 {
891 }
892 
parse_addr_range(const char * optarg)893 static void parse_addr_range(const char *optarg)
894 {
895 	unsigned long offset;
896 	unsigned long size;
897 	char *p;
898 
899 	p = strchr(optarg, ',');
900 	if (!p)
901 		p = strchr(optarg, '+');
902 
903 	if (p == optarg) {
904 		offset = 0;
905 		size   = parse_number(p + 1);
906 	} else if (p) {
907 		offset = parse_number(optarg);
908 		if (p[1] == '\0')
909 			size = ULONG_MAX;
910 		else {
911 			size = parse_number(p + 1);
912 			if (*p == ',') {
913 				if (size < offset)
914 					fatal("invalid range: %lu,%lu\n",
915 							offset, size);
916 				size -= offset;
917 			}
918 		}
919 	} else {
920 		offset = parse_number(optarg);
921 		size   = 1;
922 	}
923 
924 	add_addr_range(offset, size);
925 }
926 
add_bits_filter(uint64_t mask,uint64_t bits)927 static void add_bits_filter(uint64_t mask, uint64_t bits)
928 {
929 	if (nr_bit_filters >= MAX_BIT_FILTERS)
930 		fatal("too much bit filters\n");
931 
932 	opt_mask[nr_bit_filters] = mask;
933 	opt_bits[nr_bit_filters] = bits;
934 	nr_bit_filters++;
935 }
936 
parse_flag_name(const char * str,int len)937 static uint64_t parse_flag_name(const char *str, int len)
938 {
939 	int i;
940 
941 	if (!*str || !len)
942 		return 0;
943 
944 	if (len <= 8 && !strncmp(str, "compound", len))
945 		return BITS_COMPOUND;
946 
947 	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
948 		if (!page_flag_names[i])
949 			continue;
950 		if (!strncmp(str, page_flag_names[i] + 2, len))
951 			return 1ULL << i;
952 	}
953 
954 	return parse_number(str);
955 }
956 
parse_flag_names(const char * str,int all)957 static uint64_t parse_flag_names(const char *str, int all)
958 {
959 	const char *p    = str;
960 	uint64_t   flags = 0;
961 
962 	while (1) {
963 		if (*p == ',' || *p == '=' || *p == '\0') {
964 			if ((*str != '~') || (*str == '~' && all && *++str))
965 				flags |= parse_flag_name(str, p - str);
966 			if (*p != ',')
967 				break;
968 			str = p + 1;
969 		}
970 		p++;
971 	}
972 
973 	return flags;
974 }
975 
parse_bits_mask(const char * optarg)976 static void parse_bits_mask(const char *optarg)
977 {
978 	uint64_t mask;
979 	uint64_t bits;
980 	const char *p;
981 
982 	p = strchr(optarg, '=');
983 	if (p == optarg) {
984 		mask = KPF_ALL_BITS;
985 		bits = parse_flag_names(p + 1, 0);
986 	} else if (p) {
987 		mask = parse_flag_names(optarg, 0);
988 		bits = parse_flag_names(p + 1, 0);
989 	} else if (strchr(optarg, '~')) {
990 		mask = parse_flag_names(optarg, 1);
991 		bits = parse_flag_names(optarg, 0);
992 	} else {
993 		mask = parse_flag_names(optarg, 0);
994 		bits = KPF_ALL_BITS;
995 	}
996 
997 	add_bits_filter(mask, bits);
998 }
999 
describe_flags(const char * optarg)1000 static void describe_flags(const char *optarg)
1001 {
1002 	uint64_t flags = parse_flag_names(optarg, 0);
1003 
1004 	printf("0x%016llx\t%s\t%s\n",
1005 		(unsigned long long)flags,
1006 		page_flag_name(flags),
1007 		page_flag_longname(flags));
1008 }
1009 
1010 static const struct option opts[] = {
1011 	{ "raw"       , 0, NULL, 'r' },
1012 	{ "pid"       , 1, NULL, 'p' },
1013 	{ "file"      , 1, NULL, 'f' },
1014 	{ "addr"      , 1, NULL, 'a' },
1015 	{ "bits"      , 1, NULL, 'b' },
1016 	{ "describe"  , 1, NULL, 'd' },
1017 	{ "list"      , 0, NULL, 'l' },
1018 	{ "list-each" , 0, NULL, 'L' },
1019 	{ "no-summary", 0, NULL, 'N' },
1020 	{ "hwpoison"  , 0, NULL, 'X' },
1021 	{ "unpoison"  , 0, NULL, 'x' },
1022 	{ "help"      , 0, NULL, 'h' },
1023 	{ NULL        , 0, NULL, 0 }
1024 };
1025 
main(int argc,char * argv[])1026 int main(int argc, char *argv[])
1027 {
1028 	int c;
1029 
1030 	page_size = getpagesize();
1031 
1032 	while ((c = getopt_long(argc, argv,
1033 				"rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1034 		switch (c) {
1035 		case 'r':
1036 			opt_raw = 1;
1037 			break;
1038 		case 'p':
1039 			parse_pid(optarg);
1040 			break;
1041 		case 'f':
1042 			parse_file(optarg);
1043 			break;
1044 		case 'a':
1045 			parse_addr_range(optarg);
1046 			break;
1047 		case 'b':
1048 			parse_bits_mask(optarg);
1049 			break;
1050 		case 'd':
1051 			describe_flags(optarg);
1052 			exit(0);
1053 		case 'l':
1054 			opt_list = 1;
1055 			break;
1056 		case 'L':
1057 			opt_list = 2;
1058 			break;
1059 		case 'N':
1060 			opt_no_summary = 1;
1061 			break;
1062 		case 'X':
1063 			opt_hwpoison = 1;
1064 			prepare_hwpoison_fd();
1065 			break;
1066 		case 'x':
1067 			opt_unpoison = 1;
1068 			prepare_hwpoison_fd();
1069 			break;
1070 		case 'h':
1071 			usage();
1072 			exit(0);
1073 		default:
1074 			usage();
1075 			exit(1);
1076 		}
1077 	}
1078 
1079 	if (opt_list && opt_pid)
1080 		printf("voffset\t");
1081 	if (opt_list == 1)
1082 		printf("offset\tlen\tflags\n");
1083 	if (opt_list == 2)
1084 		printf("offset\tflags\n");
1085 
1086 	walk_addr_ranges();
1087 
1088 	if (opt_list == 1)
1089 		show_page_range(0, 0, 0);  /* drain the buffer */
1090 
1091 	if (opt_no_summary)
1092 		return 0;
1093 
1094 	if (opt_list)
1095 		printf("\n\n");
1096 
1097 	show_summary();
1098 
1099 	return 0;
1100 }
1101