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"
46 # define STR(x) _STR(x)
50 * pagemap kernel ABI bits
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)
65 #define PM_PRESENT PM_STATUS(4LL)
66 #define PM_SWAP PM_STATUS(2LL)
74 #define PROC_KPAGEFLAGS "/proc/kpageflags"
76 /* copied from kpageflags_read() */
79 #define KPF_REFERENCED 2
80 #define KPF_UPTODATE 3
85 #define KPF_WRITEBACK 8
89 /* [11-20] new additions in 2.6.31 */
92 #define KPF_SWAPCACHE 13
93 #define KPF_SWAPBACKED 14
94 #define KPF_COMPOUND_HEAD 15
95 #define KPF_COMPOUND_TAIL 16
97 #define KPF_UNEVICTABLE 18
98 #define KPF_HWPOISON 19
103 /* [32-] kernel hacking assistances */
104 #define KPF_RESERVED 32
105 #define KPF_MLOCKED 33
106 #define KPF_MAPPEDTODISK 34
107 #define KPF_PRIVATE 35
108 #define KPF_PRIVATE_2 36
109 #define KPF_OWNER_PRIVATE 37
111 #define KPF_UNCACHED 39
113 /* [48-] take some arbitrary free slots for expanding overloaded flags
114 * not part of kernel API
116 #define KPF_READAHEAD 48
117 #define KPF_SLOB_FREE 49
118 #define KPF_SLUB_FROZEN 50
119 #define KPF_SLUB_DEBUG 51
121 #define KPF_ALL_BITS ((uint64_t)~0ULL)
122 #define KPF_HACKERS_BITS (0xffffULL << 32)
123 #define KPF_OVERLOADED_BITS (0xffffULL << 48)
124 #define BIT(name) (1ULL << KPF_##name)
125 #define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
127 static const char * const page_flag_names[] = {
128 [KPF_LOCKED] = "L:locked",
129 [KPF_ERROR] = "E:error",
130 [KPF_REFERENCED] = "R:referenced",
131 [KPF_UPTODATE] = "U:uptodate",
132 [KPF_DIRTY] = "D:dirty",
134 [KPF_ACTIVE] = "A:active",
135 [KPF_SLAB] = "S:slab",
136 [KPF_WRITEBACK] = "W:writeback",
137 [KPF_RECLAIM] = "I:reclaim",
138 [KPF_BUDDY] = "B:buddy",
140 [KPF_MMAP] = "M:mmap",
141 [KPF_ANON] = "a:anonymous",
142 [KPF_SWAPCACHE] = "s:swapcache",
143 [KPF_SWAPBACKED] = "b:swapbacked",
144 [KPF_COMPOUND_HEAD] = "H:compound_head",
145 [KPF_COMPOUND_TAIL] = "T:compound_tail",
146 [KPF_HUGE] = "G:huge",
147 [KPF_UNEVICTABLE] = "u:unevictable",
148 [KPF_HWPOISON] = "X:hwpoison",
149 [KPF_NOPAGE] = "n:nopage",
153 [KPF_RESERVED] = "r:reserved",
154 [KPF_MLOCKED] = "m:mlocked",
155 [KPF_MAPPEDTODISK] = "d:mappedtodisk",
156 [KPF_PRIVATE] = "P:private",
157 [KPF_PRIVATE_2] = "p:private_2",
158 [KPF_OWNER_PRIVATE] = "O:owner_private",
159 [KPF_ARCH] = "h:arch",
160 [KPF_UNCACHED] = "c:uncached",
162 [KPF_READAHEAD] = "I:readahead",
163 [KPF_SLOB_FREE] = "P:slob_free",
164 [KPF_SLUB_FROZEN] = "A:slub_frozen",
165 [KPF_SLUB_DEBUG] = "E:slub_debug",
169 static const char * const debugfs_known_mountpoints[] = {
179 static int opt_raw; /* for kernel developers */
180 static int opt_list; /* list pages (in ranges) */
181 static int opt_no_summary; /* don't show summary */
182 static pid_t opt_pid; /* process to walk */
184 #define MAX_ADDR_RANGES 1024
185 static int nr_addr_ranges;
186 static unsigned long opt_offset[MAX_ADDR_RANGES];
187 static unsigned long opt_size[MAX_ADDR_RANGES];
189 #define MAX_VMAS 10240
191 static unsigned long pg_start[MAX_VMAS];
192 static unsigned long pg_end[MAX_VMAS];
194 #define MAX_BIT_FILTERS 64
195 static int nr_bit_filters;
196 static uint64_t opt_mask[MAX_BIT_FILTERS];
197 static uint64_t opt_bits[MAX_BIT_FILTERS];
199 static int page_size;
201 static int pagemap_fd;
202 static int kpageflags_fd;
204 static int opt_hwpoison;
205 static int opt_unpoison;
207 static char hwpoison_debug_fs[MAX_PATH+1];
208 static int hwpoison_inject_fd;
209 static int hwpoison_forget_fd;
211 #define HASH_SHIFT 13
212 #define HASH_SIZE (1 << HASH_SHIFT)
213 #define HASH_MASK (HASH_SIZE - 1)
214 #define HASH_KEY(flags) (flags & HASH_MASK)
216 static unsigned long total_pages;
217 static unsigned long nr_pages[HASH_SIZE];
218 static uint64_t page_flags[HASH_SIZE];
225 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
227 #define min_t(type, x, y) ({ \
230 __min1 < __min2 ? __min1 : __min2; })
232 #define max_t(type, x, y) ({ \
235 __max1 > __max2 ? __max1 : __max2; })
237 static unsigned long pages2mb(unsigned long pages)
239 return (pages * page_size) >> 20;
242 static void fatal(const char *x, ...)
247 vfprintf(stderr, x, ap);
252 static int checked_open(const char *pathname, int flags)
254 int fd = open(pathname, flags);
265 * pagemap/kpageflags routines
268 static unsigned long do_u64_read(int fd, char *name,
275 if (index > ULONG_MAX / 8)
276 fatal("index overflow: %lu\n", index);
278 if (lseek(fd, index * 8, SEEK_SET) < 0) {
283 bytes = read(fd, buf, count * 8);
289 fatal("partial read: %lu bytes\n", bytes);
294 static unsigned long kpageflags_read(uint64_t *buf,
298 return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
301 static unsigned long pagemap_read(uint64_t *buf,
305 return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
308 static unsigned long pagemap_pfn(uint64_t val)
312 if (val & PM_PRESENT)
313 pfn = PM_PFRAME(val);
325 static char *page_flag_name(uint64_t flags)
331 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
332 present = (flags >> i) & 1;
333 if (!page_flag_names[i]) {
335 fatal("unknown flag bit %d\n", i);
338 buf[j++] = present ? page_flag_names[i][0] : '_';
344 static char *page_flag_longname(uint64_t flags)
346 static char buf[1024];
349 for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
350 if (!page_flag_names[i])
352 if ((flags >> i) & 1)
353 n += snprintf(buf + n, sizeof(buf) - n, "%s,",
354 page_flag_names[i] + 2);
365 * page list and summary
368 static void show_page_range(unsigned long voffset,
369 unsigned long offset, uint64_t flags)
371 static uint64_t flags0;
372 static unsigned long voff;
373 static unsigned long index;
374 static unsigned long count;
376 if (flags == flags0 && offset == index + count &&
377 (!opt_pid || voffset == voff + count)) {
384 printf("%lx\t", voff);
385 printf("%lx\t%lx\t%s\n",
386 index, count, page_flag_name(flags0));
395 static void show_page(unsigned long voffset,
396 unsigned long offset, uint64_t flags)
399 printf("%lx\t", voffset);
400 printf("%lx\t%s\n", offset, page_flag_name(flags));
403 static void show_summary(void)
407 printf(" flags\tpage-count MB"
408 " symbolic-flags\t\t\tlong-symbolic-flags\n");
410 for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
412 printf("0x%016llx\t%10lu %8lu %s\t%s\n",
413 (unsigned long long)page_flags[i],
415 pages2mb(nr_pages[i]),
416 page_flag_name(page_flags[i]),
417 page_flag_longname(page_flags[i]));
420 printf(" total\t%10lu %8lu\n",
421 total_pages, pages2mb(total_pages));
429 static int bit_mask_ok(uint64_t flags)
433 for (i = 0; i < nr_bit_filters; i++) {
434 if (opt_bits[i] == KPF_ALL_BITS) {
435 if ((flags & opt_mask[i]) == 0)
438 if ((flags & opt_mask[i]) != opt_bits[i])
446 static uint64_t expand_overloaded_flags(uint64_t flags)
448 /* SLOB/SLUB overload several page flags */
449 if (flags & BIT(SLAB)) {
450 if (flags & BIT(PRIVATE))
451 flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
452 if (flags & BIT(ACTIVE))
453 flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
454 if (flags & BIT(ERROR))
455 flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
458 /* PG_reclaim is overloaded as PG_readahead in the read path */
459 if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
460 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
465 static uint64_t well_known_flags(uint64_t flags)
467 /* hide flags intended only for kernel hacker */
468 flags &= ~KPF_HACKERS_BITS;
470 /* hide non-hugeTLB compound pages */
471 if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
472 flags &= ~BITS_COMPOUND;
477 static uint64_t kpageflags_flags(uint64_t flags)
479 flags = expand_overloaded_flags(flags);
482 flags = well_known_flags(flags);
487 /* verify that a mountpoint is actually a debugfs instance */
488 static int debugfs_valid_mountpoint(const char *debugfs)
492 if (statfs(debugfs, &st_fs) < 0)
494 else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
500 /* find the path to the mounted debugfs */
501 static const char *debugfs_find_mountpoint(void)
507 ptr = debugfs_known_mountpoints;
509 if (debugfs_valid_mountpoint(*ptr) == 0) {
510 strcpy(hwpoison_debug_fs, *ptr);
511 return hwpoison_debug_fs;
516 /* give up and parse /proc/mounts */
517 fp = fopen("/proc/mounts", "r");
519 perror("Can't open /proc/mounts for read");
521 while (fscanf(fp, "%*s %"
523 "s %99s %*s %*d %*d\n",
524 hwpoison_debug_fs, type) == 2) {
525 if (strcmp(type, "debugfs") == 0)
530 if (strcmp(type, "debugfs") != 0)
533 return hwpoison_debug_fs;
536 /* mount the debugfs somewhere if it's not mounted */
538 static void debugfs_mount(void)
542 /* see if it's already mounted */
543 if (debugfs_find_mountpoint())
546 ptr = debugfs_known_mountpoints;
548 if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
549 /* save the mountpoint */
550 strcpy(hwpoison_debug_fs, *ptr);
557 perror("mount debugfs");
566 static void prepare_hwpoison_fd(void)
568 char buf[MAX_PATH + 1];
572 if (opt_hwpoison && !hwpoison_inject_fd) {
573 snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
575 hwpoison_inject_fd = checked_open(buf, O_WRONLY);
578 if (opt_unpoison && !hwpoison_forget_fd) {
579 snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
581 hwpoison_forget_fd = checked_open(buf, O_WRONLY);
585 static int hwpoison_page(unsigned long offset)
590 len = sprintf(buf, "0x%lx\n", offset);
591 len = write(hwpoison_inject_fd, buf, len);
593 perror("hwpoison inject");
599 static int unpoison_page(unsigned long offset)
604 len = sprintf(buf, "0x%lx\n", offset);
605 len = write(hwpoison_forget_fd, buf, len);
607 perror("hwpoison forget");
617 static int hash_slot(uint64_t flags)
619 int k = HASH_KEY(flags);
622 /* Explicitly reserve slot 0 for flags 0: the following logic
623 * cannot distinguish an unoccupied slot from slot (flags==0).
628 /* search through the remaining (HASH_SIZE-1) slots */
629 for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
630 if (!k || k >= ARRAY_SIZE(page_flags))
632 if (page_flags[k] == 0) {
633 page_flags[k] = flags;
636 if (page_flags[k] == flags)
640 fatal("hash table full: bump up HASH_SHIFT?\n");
644 static void add_page(unsigned long voffset,
645 unsigned long offset, uint64_t flags)
647 flags = kpageflags_flags(flags);
649 if (!bit_mask_ok(flags))
653 hwpoison_page(offset);
655 unpoison_page(offset);
658 show_page_range(voffset, offset, flags);
659 else if (opt_list == 2)
660 show_page(voffset, offset, flags);
662 nr_pages[hash_slot(flags)]++;
666 #define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
667 static void walk_pfn(unsigned long voffset,
671 uint64_t buf[KPAGEFLAGS_BATCH];
677 batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
678 pages = kpageflags_read(buf, index, batch);
682 for (i = 0; i < pages; i++)
683 add_page(voffset + i, index + i, buf[i]);
690 #define PAGEMAP_BATCH (64 << 10)
691 static void walk_vma(unsigned long index, unsigned long count)
693 uint64_t buf[PAGEMAP_BATCH];
700 batch = min_t(unsigned long, count, PAGEMAP_BATCH);
701 pages = pagemap_read(buf, index, batch);
705 for (i = 0; i < pages; i++) {
706 pfn = pagemap_pfn(buf[i]);
708 walk_pfn(index + i, pfn, 1);
716 static void walk_task(unsigned long index, unsigned long count)
718 const unsigned long end = index + count;
722 while (index < end) {
724 while (pg_end[i] <= index)
727 if (pg_start[i] >= end)
730 start = max_t(unsigned long, pg_start[i], index);
731 index = min_t(unsigned long, pg_end[i], end);
733 assert(start < index);
734 walk_vma(start, index - start);
738 static void add_addr_range(unsigned long offset, unsigned long size)
740 if (nr_addr_ranges >= MAX_ADDR_RANGES)
741 fatal("too many addr ranges\n");
743 opt_offset[nr_addr_ranges] = offset;
744 opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
748 static void walk_addr_ranges(void)
752 kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
755 add_addr_range(0, ULONG_MAX);
757 for (i = 0; i < nr_addr_ranges; i++)
759 walk_pfn(0, opt_offset[i], opt_size[i]);
761 walk_task(opt_offset[i], opt_size[i]);
763 close(kpageflags_fd);
771 static const char *page_flag_type(uint64_t flag)
773 if (flag & KPF_HACKERS_BITS)
775 if (flag & KPF_OVERLOADED_BITS)
780 static void usage(void)
785 "page-types [options]\n"
786 " -r|--raw Raw mode, for kernel developers\n"
787 " -d|--describe flags Describe flags\n"
788 " -a|--addr addr-spec Walk a range of pages\n"
789 " -b|--bits bits-spec Walk pages with specified bits\n"
790 " -p|--pid pid Walk process address space\n"
791 #if 0 /* planned features */
792 " -f|--file filename Walk file address space\n"
794 " -l|--list Show page details in ranges\n"
795 " -L|--list-each Show page details one by one\n"
796 " -N|--no-summary Don't show summary info\n"
797 " -X|--hwpoison hwpoison pages\n"
798 " -x|--unpoison unpoison pages\n"
799 " -h|--help Show this usage message\n"
801 " 0x10 bitfield format, e.g.\n"
802 " anon bit-name, e.g.\n"
803 " 0x10,anon comma-separated list, e.g.\n"
805 " N one page at offset N (unit: pages)\n"
806 " N+M pages range from N to N+M-1\n"
807 " N,M pages range from N to M-1\n"
808 " N, pages range from N to end\n"
809 " ,M pages range from 0 to M-1\n"
811 " bit1,bit2 (flags & (bit1|bit2)) != 0\n"
812 " bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
813 " bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
814 " =bit1,bit2 flags == (bit1|bit2)\n"
818 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
819 if (!page_flag_names[i])
821 printf("%16s%s", page_flag_names[i] + 2,
822 page_flag_type(1ULL << i));
829 "(r) raw mode bits (o) overloaded bits\n");
832 static unsigned long long parse_number(const char *str)
834 unsigned long long n;
836 n = strtoll(str, NULL, 0);
838 if (n == 0 && str[0] != '0')
839 fatal("invalid name or number: %s\n", str);
844 static void parse_pid(const char *str)
849 opt_pid = parse_number(str);
851 sprintf(buf, "/proc/%d/pagemap", opt_pid);
852 pagemap_fd = checked_open(buf, O_RDONLY);
854 sprintf(buf, "/proc/%d/maps", opt_pid);
855 file = fopen(buf, "r");
861 while (fgets(buf, sizeof(buf), file) != NULL) {
862 unsigned long vm_start;
863 unsigned long vm_end;
864 unsigned long long pgoff;
870 n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
878 fprintf(stderr, "unexpected line: %s\n", buf);
881 pg_start[nr_vmas] = vm_start / page_size;
882 pg_end[nr_vmas] = vm_end / page_size;
883 if (++nr_vmas >= MAX_VMAS) {
884 fprintf(stderr, "too many VMAs\n");
891 static void parse_file(const char *name)
895 static void parse_addr_range(const char *optarg)
897 unsigned long offset;
901 p = strchr(optarg, ',');
903 p = strchr(optarg, '+');
907 size = parse_number(p + 1);
909 offset = parse_number(optarg);
913 size = parse_number(p + 1);
916 fatal("invalid range: %lu,%lu\n",
922 offset = parse_number(optarg);
926 add_addr_range(offset, size);
929 static void add_bits_filter(uint64_t mask, uint64_t bits)
931 if (nr_bit_filters >= MAX_BIT_FILTERS)
932 fatal("too much bit filters\n");
934 opt_mask[nr_bit_filters] = mask;
935 opt_bits[nr_bit_filters] = bits;
939 static uint64_t parse_flag_name(const char *str, int len)
946 if (len <= 8 && !strncmp(str, "compound", len))
947 return BITS_COMPOUND;
949 for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
950 if (!page_flag_names[i])
952 if (!strncmp(str, page_flag_names[i] + 2, len))
956 return parse_number(str);
959 static uint64_t parse_flag_names(const char *str, int all)
965 if (*p == ',' || *p == '=' || *p == '\0') {
966 if ((*str != '~') || (*str == '~' && all && *++str))
967 flags |= parse_flag_name(str, p - str);
978 static void parse_bits_mask(const char *optarg)
984 p = strchr(optarg, '=');
987 bits = parse_flag_names(p + 1, 0);
989 mask = parse_flag_names(optarg, 0);
990 bits = parse_flag_names(p + 1, 0);
991 } else if (strchr(optarg, '~')) {
992 mask = parse_flag_names(optarg, 1);
993 bits = parse_flag_names(optarg, 0);
995 mask = parse_flag_names(optarg, 0);
999 add_bits_filter(mask, bits);
1002 static void describe_flags(const char *optarg)
1004 uint64_t flags = parse_flag_names(optarg, 0);
1006 printf("0x%016llx\t%s\t%s\n",
1007 (unsigned long long)flags,
1008 page_flag_name(flags),
1009 page_flag_longname(flags));
1012 static const struct option opts[] = {
1013 { "raw" , 0, NULL, 'r' },
1014 { "pid" , 1, NULL, 'p' },
1015 { "file" , 1, NULL, 'f' },
1016 { "addr" , 1, NULL, 'a' },
1017 { "bits" , 1, NULL, 'b' },
1018 { "describe" , 1, NULL, 'd' },
1019 { "list" , 0, NULL, 'l' },
1020 { "list-each" , 0, NULL, 'L' },
1021 { "no-summary", 0, NULL, 'N' },
1022 { "hwpoison" , 0, NULL, 'X' },
1023 { "unpoison" , 0, NULL, 'x' },
1024 { "help" , 0, NULL, 'h' },
1025 { NULL , 0, NULL, 0 }
1028 int main(int argc, char *argv[])
1032 page_size = getpagesize();
1034 while ((c = getopt_long(argc, argv,
1035 "rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
1047 parse_addr_range(optarg);
1050 parse_bits_mask(optarg);
1053 describe_flags(optarg);
1066 prepare_hwpoison_fd();
1070 prepare_hwpoison_fd();
1081 if (opt_list && opt_pid)
1082 printf("voffset\t");
1084 printf("offset\tlen\tflags\n");
1086 printf("offset\tflags\n");
1091 show_page_range(0, 0, 0); /* drain the buffer */