2 * page-types: Tool for querying page flags
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.
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
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.
17 * Copyright (C) 2009 Intel corporation
19 * Authors: Wu Fengguang <fengguang.wu@intel.com>
22 #define _LARGEFILE64_SOURCE
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 #include "../../include/linux/kernel-page-flags.h"
47 # define STR(x) _STR(x)
51 * pagemap kernel ABI bits
54 #define PM_ENTRY_BYTES sizeof(uint64_t)
55 #define PM_STATUS_BITS 3
56 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
57 #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
58 #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
59 #define PM_PSHIFT_BITS 6
60 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
61 #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
62 #define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
63 #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
64 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
66 #define PM_PRESENT PM_STATUS(4LL)
67 #define PM_SWAP PM_STATUS(2LL)
75 #define PROC_KPAGEFLAGS "/proc/kpageflags"
77 /* [32-] kernel hacking assistances */
78 #define KPF_RESERVED 32
79 #define KPF_MLOCKED 33
80 #define KPF_MAPPEDTODISK 34
81 #define KPF_PRIVATE 35
82 #define KPF_PRIVATE_2 36
83 #define KPF_OWNER_PRIVATE 37
85 #define KPF_UNCACHED 39
87 /* [48-] take some arbitrary free slots for expanding overloaded flags
88 * not part of kernel API
90 #define KPF_READAHEAD 48
91 #define KPF_SLOB_FREE 49
92 #define KPF_SLUB_FROZEN 50
93 #define KPF_SLUB_DEBUG 51
95 #define KPF_ALL_BITS ((uint64_t)~0ULL)
96 #define KPF_HACKERS_BITS (0xffffULL << 32)
97 #define KPF_OVERLOADED_BITS (0xffffULL << 48)
98 #define BIT(name) (1ULL << KPF_##name)
99 #define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
101 static const char * const page_flag_names[] = {
102 [KPF_LOCKED] = "L:locked",
103 [KPF_ERROR] = "E:error",
104 [KPF_REFERENCED] = "R:referenced",
105 [KPF_UPTODATE] = "U:uptodate",
106 [KPF_DIRTY] = "D:dirty",
108 [KPF_ACTIVE] = "A:active",
109 [KPF_SLAB] = "S:slab",
110 [KPF_WRITEBACK] = "W:writeback",
111 [KPF_RECLAIM] = "I:reclaim",
112 [KPF_BUDDY] = "B:buddy",
114 [KPF_MMAP] = "M:mmap",
115 [KPF_ANON] = "a:anonymous",
116 [KPF_SWAPCACHE] = "s:swapcache",
117 [KPF_SWAPBACKED] = "b:swapbacked",
118 [KPF_COMPOUND_HEAD] = "H:compound_head",
119 [KPF_COMPOUND_TAIL] = "T:compound_tail",
120 [KPF_HUGE] = "G:huge",
121 [KPF_UNEVICTABLE] = "u:unevictable",
122 [KPF_HWPOISON] = "X:hwpoison",
123 [KPF_NOPAGE] = "n:nopage",
127 [KPF_RESERVED] = "r:reserved",
128 [KPF_MLOCKED] = "m:mlocked",
129 [KPF_MAPPEDTODISK] = "d:mappedtodisk",
130 [KPF_PRIVATE] = "P:private",
131 [KPF_PRIVATE_2] = "p:private_2",
132 [KPF_OWNER_PRIVATE] = "O:owner_private",
133 [KPF_ARCH] = "h:arch",
134 [KPF_UNCACHED] = "c:uncached",
136 [KPF_READAHEAD] = "I:readahead",
137 [KPF_SLOB_FREE] = "P:slob_free",
138 [KPF_SLUB_FROZEN] = "A:slub_frozen",
139 [KPF_SLUB_DEBUG] = "E:slub_debug",
143 static const char * const debugfs_known_mountpoints[] = {
153 static int opt_raw; /* for kernel developers */
154 static int opt_list; /* list pages (in ranges) */
155 static int opt_no_summary; /* don't show summary */
156 static pid_t opt_pid; /* process to walk */
158 #define MAX_ADDR_RANGES 1024
159 static int nr_addr_ranges;
160 static unsigned long opt_offset[MAX_ADDR_RANGES];
161 static unsigned long opt_size[MAX_ADDR_RANGES];
163 #define MAX_VMAS 10240
165 static unsigned long pg_start[MAX_VMAS];
166 static unsigned long pg_end[MAX_VMAS];
168 #define MAX_BIT_FILTERS 64
169 static int nr_bit_filters;
170 static uint64_t opt_mask[MAX_BIT_FILTERS];
171 static uint64_t opt_bits[MAX_BIT_FILTERS];
173 static int page_size;
175 static int pagemap_fd;
176 static int kpageflags_fd;
178 static int opt_hwpoison;
179 static int opt_unpoison;
181 static char hwpoison_debug_fs[MAX_PATH+1];
182 static int hwpoison_inject_fd;
183 static int hwpoison_forget_fd;
185 #define HASH_SHIFT 13
186 #define HASH_SIZE (1 << HASH_SHIFT)
187 #define HASH_MASK (HASH_SIZE - 1)
188 #define HASH_KEY(flags) (flags & HASH_MASK)
190 static unsigned long total_pages;
191 static unsigned long nr_pages[HASH_SIZE];
192 static uint64_t page_flags[HASH_SIZE];
199 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
201 #define min_t(type, x, y) ({ \
204 __min1 < __min2 ? __min1 : __min2; })
206 #define max_t(type, x, y) ({ \
209 __max1 > __max2 ? __max1 : __max2; })
211 static unsigned long pages2mb(unsigned long pages)
213 return (pages * page_size) >> 20;
216 static void fatal(const char *x, ...)
221 vfprintf(stderr, x, ap);
226 static int checked_open(const char *pathname, int flags)
228 int fd = open(pathname, flags);
239 * pagemap/kpageflags routines
242 static unsigned long do_u64_read(int fd, char *name,
249 if (index > ULONG_MAX / 8)
250 fatal("index overflow: %lu\n", index);
252 if (lseek(fd, index * 8, SEEK_SET) < 0) {
257 bytes = read(fd, buf, count * 8);
263 fatal("partial read: %lu bytes\n", bytes);
268 static unsigned long kpageflags_read(uint64_t *buf,
272 return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
275 static unsigned long pagemap_read(uint64_t *buf,
279 return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
282 static unsigned long pagemap_pfn(uint64_t val)
286 if (val & PM_PRESENT)
287 pfn = PM_PFRAME(val);
299 static char *page_flag_name(uint64_t flags)
305 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
306 present = (flags >> i) & 1;
307 if (!page_flag_names[i]) {
309 fatal("unknown flag bit %d\n", i);
312 buf[j++] = present ? page_flag_names[i][0] : '_';
318 static char *page_flag_longname(uint64_t flags)
320 static char buf[1024];
323 for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
324 if (!page_flag_names[i])
326 if ((flags >> i) & 1)
327 n += snprintf(buf + n, sizeof(buf) - n, "%s,",
328 page_flag_names[i] + 2);
339 * page list and summary
342 static void show_page_range(unsigned long voffset,
343 unsigned long offset, uint64_t flags)
345 static uint64_t flags0;
346 static unsigned long voff;
347 static unsigned long index;
348 static unsigned long count;
350 if (flags == flags0 && offset == index + count &&
351 (!opt_pid || voffset == voff + count)) {
358 printf("%lx\t", voff);
359 printf("%lx\t%lx\t%s\n",
360 index, count, page_flag_name(flags0));
369 static void show_page(unsigned long voffset,
370 unsigned long offset, uint64_t flags)
373 printf("%lx\t", voffset);
374 printf("%lx\t%s\n", offset, page_flag_name(flags));
377 static void show_summary(void)
381 printf(" flags\tpage-count MB"
382 " symbolic-flags\t\t\tlong-symbolic-flags\n");
384 for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
386 printf("0x%016llx\t%10lu %8lu %s\t%s\n",
387 (unsigned long long)page_flags[i],
389 pages2mb(nr_pages[i]),
390 page_flag_name(page_flags[i]),
391 page_flag_longname(page_flags[i]));
394 printf(" total\t%10lu %8lu\n",
395 total_pages, pages2mb(total_pages));
403 static int bit_mask_ok(uint64_t flags)
407 for (i = 0; i < nr_bit_filters; i++) {
408 if (opt_bits[i] == KPF_ALL_BITS) {
409 if ((flags & opt_mask[i]) == 0)
412 if ((flags & opt_mask[i]) != opt_bits[i])
420 static uint64_t expand_overloaded_flags(uint64_t flags)
422 /* SLOB/SLUB overload several page flags */
423 if (flags & BIT(SLAB)) {
424 if (flags & BIT(PRIVATE))
425 flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
426 if (flags & BIT(ACTIVE))
427 flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
428 if (flags & BIT(ERROR))
429 flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
432 /* PG_reclaim is overloaded as PG_readahead in the read path */
433 if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
434 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
439 static uint64_t well_known_flags(uint64_t flags)
441 /* hide flags intended only for kernel hacker */
442 flags &= ~KPF_HACKERS_BITS;
444 /* hide non-hugeTLB compound pages */
445 if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
446 flags &= ~BITS_COMPOUND;
451 static uint64_t kpageflags_flags(uint64_t flags)
453 flags = expand_overloaded_flags(flags);
456 flags = well_known_flags(flags);
461 /* verify that a mountpoint is actually a debugfs instance */
462 static int debugfs_valid_mountpoint(const char *debugfs)
466 if (statfs(debugfs, &st_fs) < 0)
468 else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
474 /* find the path to the mounted debugfs */
475 static const char *debugfs_find_mountpoint(void)
477 const char *const *ptr;
481 ptr = debugfs_known_mountpoints;
483 if (debugfs_valid_mountpoint(*ptr) == 0) {
484 strcpy(hwpoison_debug_fs, *ptr);
485 return hwpoison_debug_fs;
490 /* give up and parse /proc/mounts */
491 fp = fopen("/proc/mounts", "r");
493 perror("Can't open /proc/mounts for read");
495 while (fscanf(fp, "%*s %"
497 "s %99s %*s %*d %*d\n",
498 hwpoison_debug_fs, type) == 2) {
499 if (strcmp(type, "debugfs") == 0)
504 if (strcmp(type, "debugfs") != 0)
507 return hwpoison_debug_fs;
510 /* mount the debugfs somewhere if it's not mounted */
512 static void debugfs_mount(void)
514 const char *const *ptr;
516 /* see if it's already mounted */
517 if (debugfs_find_mountpoint())
520 ptr = debugfs_known_mountpoints;
522 if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
523 /* save the mountpoint */
524 strcpy(hwpoison_debug_fs, *ptr);
531 perror("mount debugfs");
540 static void prepare_hwpoison_fd(void)
542 char buf[MAX_PATH + 1];
546 if (opt_hwpoison && !hwpoison_inject_fd) {
547 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
549 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
552 if (opt_unpoison && !hwpoison_forget_fd) {
553 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
555 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
559 static int hwpoison_page(unsigned long offset)
564 len = sprintf(buf, "0x%lx\n", offset);
565 len = write(hwpoison_inject_fd, buf, len);
567 perror("hwpoison inject");
573 static int unpoison_page(unsigned long offset)
578 len = sprintf(buf, "0x%lx\n", offset);
579 len = write(hwpoison_forget_fd, buf, len);
581 perror("hwpoison forget");
591 static size_t hash_slot(uint64_t flags)
593 size_t k = HASH_KEY(flags);
596 /* Explicitly reserve slot 0 for flags 0: the following logic
597 * cannot distinguish an unoccupied slot from slot (flags==0).
602 /* search through the remaining (HASH_SIZE-1) slots */
603 for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
604 if (!k || k >= ARRAY_SIZE(page_flags))
606 if (page_flags[k] == 0) {
607 page_flags[k] = flags;
610 if (page_flags[k] == flags)
614 fatal("hash table full: bump up HASH_SHIFT?\n");
618 static void add_page(unsigned long voffset,
619 unsigned long offset, uint64_t flags)
621 flags = kpageflags_flags(flags);
623 if (!bit_mask_ok(flags))
627 hwpoison_page(offset);
629 unpoison_page(offset);
632 show_page_range(voffset, offset, flags);
633 else if (opt_list == 2)
634 show_page(voffset, offset, flags);
636 nr_pages[hash_slot(flags)]++;
640 #define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
641 static void walk_pfn(unsigned long voffset,
645 uint64_t buf[KPAGEFLAGS_BATCH];
651 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
652 pages = kpageflags_read(buf, index, batch);
656 for (i = 0; i < pages; i++)
657 add_page(voffset + i, index + i, buf[i]);
664 #define PAGEMAP_BATCH (64 << 10)
665 static void walk_vma(unsigned long index, unsigned long count)
667 uint64_t buf[PAGEMAP_BATCH];
674 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
675 pages = pagemap_read(buf, index, batch);
679 for (i = 0; i < pages; i++) {
680 pfn = pagemap_pfn(buf[i]);
682 walk_pfn(index + i, pfn, 1);
690 static void walk_task(unsigned long index, unsigned long count)
692 const unsigned long end = index + count;
696 while (index < end) {
698 while (pg_end[i] <= index)
701 if (pg_start[i] >= end)
704 start = max_t(unsigned long, pg_start[i], index);
705 index = min_t(unsigned long, pg_end[i], end);
707 assert(start < index);
708 walk_vma(start, index - start);
712 static void add_addr_range(unsigned long offset, unsigned long size)
714 if (nr_addr_ranges >= MAX_ADDR_RANGES)
715 fatal("too many addr ranges\n");
717 opt_offset[nr_addr_ranges] = offset;
718 opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
722 static void walk_addr_ranges(void)
726 kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
729 add_addr_range(0, ULONG_MAX);
731 for (i = 0; i < nr_addr_ranges; i++)
733 walk_pfn(0, opt_offset[i], opt_size[i]);
735 walk_task(opt_offset[i], opt_size[i]);
737 close(kpageflags_fd);
745 static const char *page_flag_type(uint64_t flag)
747 if (flag & KPF_HACKERS_BITS)
749 if (flag & KPF_OVERLOADED_BITS)
754 static void usage(void)
759 "page-types [options]\n"
760 " -r|--raw Raw mode, for kernel developers\n"
761 " -d|--describe flags Describe flags\n"
762 " -a|--addr addr-spec Walk a range of pages\n"
763 " -b|--bits bits-spec Walk pages with specified bits\n"
764 " -p|--pid pid Walk process address space\n"
765 #if 0 /* planned features */
766 " -f|--file filename Walk file address space\n"
768 " -l|--list Show page details in ranges\n"
769 " -L|--list-each Show page details one by one\n"
770 " -N|--no-summary Don't show summary info\n"
771 " -X|--hwpoison hwpoison pages\n"
772 " -x|--unpoison unpoison pages\n"
773 " -h|--help Show this usage message\n"
775 " 0x10 bitfield format, e.g.\n"
776 " anon bit-name, e.g.\n"
777 " 0x10,anon comma-separated list, e.g.\n"
779 " N one page at offset N (unit: pages)\n"
780 " N+M pages range from N to N+M-1\n"
781 " N,M pages range from N to M-1\n"
782 " N, pages range from N to end\n"
783 " ,M pages range from 0 to M-1\n"
785 " bit1,bit2 (flags & (bit1|bit2)) != 0\n"
786 " bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
787 " bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
788 " =bit1,bit2 flags == (bit1|bit2)\n"
792 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
793 if (!page_flag_names[i])
795 printf("%16s%s", page_flag_names[i] + 2,
796 page_flag_type(1ULL << i));
803 "(r) raw mode bits (o) overloaded bits\n");
806 static unsigned long long parse_number(const char *str)
808 unsigned long long n;
810 n = strtoll(str, NULL, 0);
812 if (n == 0 && str[0] != '0')
813 fatal("invalid name or number: %s\n", str);
818 static void parse_pid(const char *str)
823 opt_pid = parse_number(str);
825 sprintf(buf, "/proc/%d/pagemap", opt_pid);
826 pagemap_fd = checked_open(buf, O_RDONLY);
828 sprintf(buf, "/proc/%d/maps", opt_pid);
829 file = fopen(buf, "r");
835 while (fgets(buf, sizeof(buf), file) != NULL) {
836 unsigned long vm_start;
837 unsigned long vm_end;
838 unsigned long long pgoff;
844 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
852 fprintf(stderr, "unexpected line: %s\n", buf);
855 pg_start[nr_vmas] = vm_start / page_size;
856 pg_end[nr_vmas] = vm_end / page_size;
857 if (++nr_vmas >= MAX_VMAS) {
858 fprintf(stderr, "too many VMAs\n");
865 static void parse_file(const char *name)
869 static void parse_addr_range(const char *optarg)
871 unsigned long offset;
875 p = strchr(optarg, ',');
877 p = strchr(optarg, '+');
881 size = parse_number(p + 1);
883 offset = parse_number(optarg);
887 size = parse_number(p + 1);
890 fatal("invalid range: %lu,%lu\n",
896 offset = parse_number(optarg);
900 add_addr_range(offset, size);
903 static void add_bits_filter(uint64_t mask, uint64_t bits)
905 if (nr_bit_filters >= MAX_BIT_FILTERS)
906 fatal("too much bit filters\n");
908 opt_mask[nr_bit_filters] = mask;
909 opt_bits[nr_bit_filters] = bits;
913 static uint64_t parse_flag_name(const char *str, int len)
920 if (len <= 8 && !strncmp(str, "compound", len))
921 return BITS_COMPOUND;
923 for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
924 if (!page_flag_names[i])
926 if (!strncmp(str, page_flag_names[i] + 2, len))
930 return parse_number(str);
933 static uint64_t parse_flag_names(const char *str, int all)
939 if (*p == ',' || *p == '=' || *p == '\0') {
940 if ((*str != '~') || (*str == '~' && all && *++str))
941 flags |= parse_flag_name(str, p - str);
952 static void parse_bits_mask(const char *optarg)
958 p = strchr(optarg, '=');
961 bits = parse_flag_names(p + 1, 0);
963 mask = parse_flag_names(optarg, 0);
964 bits = parse_flag_names(p + 1, 0);
965 } else if (strchr(optarg, '~')) {
966 mask = parse_flag_names(optarg, 1);
967 bits = parse_flag_names(optarg, 0);
969 mask = parse_flag_names(optarg, 0);
973 add_bits_filter(mask, bits);
976 static void describe_flags(const char *optarg)
978 uint64_t flags = parse_flag_names(optarg, 0);
980 printf("0x%016llx\t%s\t%s\n",
981 (unsigned long long)flags,
982 page_flag_name(flags),
983 page_flag_longname(flags));
986 static const struct option opts[] = {
987 { "raw" , 0, NULL, 'r' },
988 { "pid" , 1, NULL, 'p' },
989 { "file" , 1, NULL, 'f' },
990 { "addr" , 1, NULL, 'a' },
991 { "bits" , 1, NULL, 'b' },
992 { "describe" , 1, NULL, 'd' },
993 { "list" , 0, NULL, 'l' },
994 { "list-each" , 0, NULL, 'L' },
995 { "no-summary", 0, NULL, 'N' },
996 { "hwpoison" , 0, NULL, 'X' },
997 { "unpoison" , 0, NULL, 'x' },
998 { "help" , 0, NULL, 'h' },
999 { NULL , 0, NULL, 0 }
1002 int main(int argc, char *argv[])
1006 page_size = getpagesize();
1008 while ((c = getopt_long(argc, argv,
1009 "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1021 parse_addr_range(optarg);
1024 parse_bits_mask(optarg);
1027 describe_flags(optarg);
1040 prepare_hwpoison_fd();
1044 prepare_hwpoison_fd();
1055 if (opt_list && opt_pid)
1056 printf("voffset\t");
1058 printf("offset\tlen\tflags\n");
1060 printf("offset\tflags\n");
1065 show_page_range(0, 0, 0); /* drain the buffer */