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v5.14.15
   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/* [48-] take some arbitrary free slots for expanding overloaded flags
  84 * not part of kernel API
  85 */
  86#define KPF_READAHEAD		48
  87#define KPF_SLOB_FREE		49
  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_READAHEAD]		= "I:readahead",
 142	[KPF_SLOB_FREE]		= "P:slob_free",
 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("%lu\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("%lu\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	/* SLOB/SLUB overload several page flags */
 476	if (flags & BIT(SLAB)) {
 477		if (flags & BIT(PRIVATE))
 478			flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 479		if (flags & BIT(ACTIVE))
 480			flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 481		if (flags & BIT(ERROR))
 482			flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 483	}
 484
 485	/* PG_reclaim is overloaded as PG_readahead in the read path */
 486	if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 487		flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 488
 489	if (pme & PM_SOFT_DIRTY)
 490		flags |= BIT(SOFTDIRTY);
 491	if (pme & PM_FILE)
 492		flags |= BIT(FILE);
 493	if (pme & PM_SWAP)
 494		flags |= BIT(SWAP);
 495	if (pme & PM_MMAP_EXCLUSIVE)
 496		flags |= BIT(MMAP_EXCLUSIVE);
 497
 498	return flags;
 499}
 500
 501static uint64_t well_known_flags(uint64_t flags)
 502{
 503	/* hide flags intended only for kernel hacker */
 504	flags &= ~KPF_HACKERS_BITS;
 505
 506	/* hide non-hugeTLB compound pages */
 507	if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 508		flags &= ~BITS_COMPOUND;
 509
 510	return flags;
 511}
 512
 513static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 514{
 515	if (opt_raw)
 516		flags = expand_overloaded_flags(flags, pme);
 517	else
 518		flags = well_known_flags(flags);
 519
 520	return flags;
 521}
 522
 523/*
 524 * page actions
 525 */
 526
 527static void prepare_hwpoison_fd(void)
 528{
 529	char buf[MAX_PATH + 1];
 530
 531	hwpoison_debug_fs = debugfs__mount();
 532	if (!hwpoison_debug_fs) {
 533		perror("mount debugfs");
 534		exit(EXIT_FAILURE);
 535	}
 536
 537	if (opt_hwpoison && !hwpoison_inject_fd) {
 538		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 539			hwpoison_debug_fs);
 540		hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 541	}
 542
 543	if (opt_unpoison && !hwpoison_forget_fd) {
 544		snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 545			hwpoison_debug_fs);
 546		hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 547	}
 548}
 549
 550static int hwpoison_page(unsigned long offset)
 551{
 552	char buf[100];
 553	int len;
 554
 555	len = sprintf(buf, "0x%lx\n", offset);
 556	len = write(hwpoison_inject_fd, buf, len);
 557	if (len < 0) {
 558		perror("hwpoison inject");
 559		return len;
 560	}
 561	return 0;
 562}
 563
 564static int unpoison_page(unsigned long offset)
 565{
 566	char buf[100];
 567	int len;
 568
 569	len = sprintf(buf, "0x%lx\n", offset);
 570	len = write(hwpoison_forget_fd, buf, len);
 571	if (len < 0) {
 572		perror("hwpoison forget");
 573		return len;
 574	}
 575	return 0;
 576}
 577
 578static int mark_page_idle(unsigned long offset)
 579{
 580	static unsigned long off;
 581	static uint64_t buf;
 582	int len;
 583
 584	if ((offset / 64 == off / 64) || buf == 0) {
 585		buf |= 1UL << (offset % 64);
 586		off = offset;
 587		return 0;
 588	}
 589
 590	len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
 591	if (len < 0) {
 592		perror("mark page idle");
 593		return len;
 594	}
 595
 596	buf = 1UL << (offset % 64);
 597	off = offset;
 598
 599	return 0;
 600}
 601
 602/*
 603 * page frame walker
 604 */
 605
 606static size_t hash_slot(uint64_t flags)
 607{
 608	size_t k = HASH_KEY(flags);
 609	size_t i;
 610
 611	/* Explicitly reserve slot 0 for flags 0: the following logic
 612	 * cannot distinguish an unoccupied slot from slot (flags==0).
 613	 */
 614	if (flags == 0)
 615		return 0;
 616
 617	/* search through the remaining (HASH_SIZE-1) slots */
 618	for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 619		if (!k || k >= ARRAY_SIZE(page_flags))
 620			k = 1;
 621		if (page_flags[k] == 0) {
 622			page_flags[k] = flags;
 623			return k;
 624		}
 625		if (page_flags[k] == flags)
 626			return k;
 627	}
 628
 629	fatal("hash table full: bump up HASH_SHIFT?\n");
 630	exit(EXIT_FAILURE);
 631}
 632
 633static void add_page(unsigned long voffset, unsigned long offset,
 634		     uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
 635		     uint64_t pme)
 636{
 637	flags = kpageflags_flags(flags, pme);
 638
 639	if (!bit_mask_ok(flags))
 640		return;
 641
 642	if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
 643		return;
 644
 645	if (opt_hwpoison)
 646		hwpoison_page(offset);
 647	if (opt_unpoison)
 648		unpoison_page(offset);
 649
 650	if (opt_mark_idle)
 651		mark_page_idle(offset);
 652
 653	if (opt_list == 1)
 654		show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
 655	else if (opt_list == 2)
 656		show_page(voffset, offset, flags, cgroup, mapcnt);
 657
 658	nr_pages[hash_slot(flags)]++;
 659	total_pages++;
 660}
 661
 662#define KPAGEFLAGS_BATCH	(64 << 10)	/* 64k pages */
 663static void walk_pfn(unsigned long voffset,
 664		     unsigned long index,
 665		     unsigned long count,
 666		     uint64_t pme)
 667{
 668	uint64_t buf[KPAGEFLAGS_BATCH];
 669	uint64_t cgi[KPAGEFLAGS_BATCH];
 670	uint64_t cnt[KPAGEFLAGS_BATCH];
 671	unsigned long batch;
 672	unsigned long pages;
 673	unsigned long i;
 674
 675	/*
 676	 * kpagecgroup_read() reads only if kpagecgroup were opened, but
 677	 * /proc/kpagecgroup might even not exist, so it's better to fill
 678	 * them with zeros here.
 679	 */
 680	if (count == 1)
 681		cgi[0] = 0;
 682	else
 683		memset(cgi, 0, sizeof cgi);
 684
 685	while (count) {
 686		batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 687		pages = kpageflags_read(buf, index, batch);
 688		if (pages == 0)
 689			break;
 690
 691		if (kpagecgroup_read(cgi, index, pages) != pages)
 692			fatal("kpagecgroup returned fewer pages than expected");
 693
 694		if (kpagecount_read(cnt, index, pages) != pages)
 695			fatal("kpagecount returned fewer pages than expected");
 696
 697		for (i = 0; i < pages; i++)
 698			add_page(voffset + i, index + i,
 699				 buf[i], cgi[i], cnt[i], pme);
 700
 701		index += pages;
 702		count -= pages;
 703	}
 704}
 705
 706static void walk_swap(unsigned long voffset, uint64_t pme)
 707{
 708	uint64_t flags = kpageflags_flags(0, pme);
 709
 710	if (!bit_mask_ok(flags))
 711		return;
 712
 713	if (opt_cgroup)
 714		return;
 715
 716	if (opt_list == 1)
 717		show_page_range(voffset, pagemap_swap_offset(pme),
 718				1, flags, 0, 0);
 719	else if (opt_list == 2)
 720		show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
 721
 722	nr_pages[hash_slot(flags)]++;
 723	total_pages++;
 724}
 725
 726#define PAGEMAP_BATCH	(64 << 10)
 727static void walk_vma(unsigned long index, unsigned long count)
 728{
 729	uint64_t buf[PAGEMAP_BATCH];
 730	unsigned long batch;
 731	unsigned long pages;
 732	unsigned long pfn;
 733	unsigned long i;
 734
 735	while (count) {
 736		batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 737		pages = pagemap_read(buf, index, batch);
 738		if (pages == 0)
 739			break;
 740
 741		for (i = 0; i < pages; i++) {
 742			pfn = pagemap_pfn(buf[i]);
 743			if (pfn)
 744				walk_pfn(index + i, pfn, 1, buf[i]);
 745			if (buf[i] & PM_SWAP)
 746				walk_swap(index + i, buf[i]);
 747		}
 748
 749		index += pages;
 750		count -= pages;
 751	}
 752}
 753
 754static void walk_task(unsigned long index, unsigned long count)
 755{
 756	const unsigned long end = index + count;
 757	unsigned long start;
 758	int i = 0;
 759
 760	while (index < end) {
 761
 762		while (pg_end[i] <= index)
 763			if (++i >= nr_vmas)
 764				return;
 765		if (pg_start[i] >= end)
 766			return;
 767
 768		start = max_t(unsigned long, pg_start[i], index);
 769		index = min_t(unsigned long, pg_end[i], end);
 770
 771		assert(start < index);
 772		walk_vma(start, index - start);
 773	}
 774}
 775
 776static void add_addr_range(unsigned long offset, unsigned long size)
 777{
 778	if (nr_addr_ranges >= MAX_ADDR_RANGES)
 779		fatal("too many addr ranges\n");
 780
 781	opt_offset[nr_addr_ranges] = offset;
 782	opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 783	nr_addr_ranges++;
 784}
 785
 786static void walk_addr_ranges(void)
 787{
 788	int i;
 789
 790	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
 791
 792	if (!nr_addr_ranges)
 793		add_addr_range(0, ULONG_MAX);
 794
 795	for (i = 0; i < nr_addr_ranges; i++)
 796		if (!opt_pid)
 797			walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 798		else
 799			walk_task(opt_offset[i], opt_size[i]);
 800
 801	if (opt_mark_idle)
 802		mark_page_idle(0);
 803
 804	close(kpageflags_fd);
 805}
 806
 807
 808/*
 809 * user interface
 810 */
 811
 812static const char *page_flag_type(uint64_t flag)
 813{
 814	if (flag & KPF_HACKERS_BITS)
 815		return "(r)";
 816	if (flag & KPF_OVERLOADED_BITS)
 817		return "(o)";
 818	return "   ";
 819}
 820
 821static void usage(void)
 822{
 823	size_t i, j;
 824
 825	printf(
 826"page-types [options]\n"
 827"            -r|--raw                   Raw mode, for kernel developers\n"
 828"            -d|--describe flags        Describe flags\n"
 829"            -a|--addr    addr-spec     Walk a range of pages\n"
 830"            -b|--bits    bits-spec     Walk pages with specified bits\n"
 831"            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
 832"            -p|--pid     pid           Walk process address space\n"
 833"            -f|--file    filename      Walk file address space\n"
 834"            -i|--mark-idle             Mark pages idle\n"
 835"            -l|--list                  Show page details in ranges\n"
 836"            -L|--list-each             Show page details one by one\n"
 837"            -C|--list-cgroup           Show cgroup inode for pages\n"
 838"            -M|--list-mapcnt           Show page map count\n"
 839"            -N|--no-summary            Don't show summary info\n"
 840"            -X|--hwpoison              hwpoison pages\n"
 841"            -x|--unpoison              unpoison pages\n"
 842"            -F|--kpageflags filename   kpageflags file to parse\n"
 843"            -h|--help                  Show this usage message\n"
 844"flags:\n"
 845"            0x10                       bitfield format, e.g.\n"
 846"            anon                       bit-name, e.g.\n"
 847"            0x10,anon                  comma-separated list, e.g.\n"
 848"addr-spec:\n"
 849"            N                          one page at offset N (unit: pages)\n"
 850"            N+M                        pages range from N to N+M-1\n"
 851"            N,M                        pages range from N to M-1\n"
 852"            N,                         pages range from N to end\n"
 853"            ,M                         pages range from 0 to M-1\n"
 854"bits-spec:\n"
 855"            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 856"            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 857"            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 858"            =bit1,bit2                 flags == (bit1|bit2)\n"
 859"bit-names:\n"
 860	);
 861
 862	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 863		if (!page_flag_names[i])
 864			continue;
 865		printf("%16s%s", page_flag_names[i] + 2,
 866				 page_flag_type(1ULL << i));
 867		if (++j > 3) {
 868			j = 0;
 869			putchar('\n');
 870		}
 871	}
 872	printf("\n                                   "
 873		"(r) raw mode bits  (o) overloaded bits\n");
 874}
 875
 876static unsigned long long parse_number(const char *str)
 877{
 878	unsigned long long n;
 879
 880	n = strtoll(str, NULL, 0);
 881
 882	if (n == 0 && str[0] != '0')
 883		fatal("invalid name or number: %s\n", str);
 884
 885	return n;
 886}
 887
 888static void parse_pid(const char *str)
 889{
 890	FILE *file;
 891	char buf[5000];
 892
 893	opt_pid = parse_number(str);
 894
 895	sprintf(buf, "/proc/%d/pagemap", opt_pid);
 896	pagemap_fd = checked_open(buf, O_RDONLY);
 897
 898	sprintf(buf, "/proc/%d/maps", opt_pid);
 899	file = fopen(buf, "r");
 900	if (!file) {
 901		perror(buf);
 902		exit(EXIT_FAILURE);
 903	}
 904
 905	while (fgets(buf, sizeof(buf), file) != NULL) {
 906		unsigned long vm_start;
 907		unsigned long vm_end;
 908		unsigned long long pgoff;
 909		int major, minor;
 910		char r, w, x, s;
 911		unsigned long ino;
 912		int n;
 913
 914		n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 915			   &vm_start,
 916			   &vm_end,
 917			   &r, &w, &x, &s,
 918			   &pgoff,
 919			   &major, &minor,
 920			   &ino);
 921		if (n < 10) {
 922			fprintf(stderr, "unexpected line: %s\n", buf);
 923			continue;
 924		}
 925		pg_start[nr_vmas] = vm_start / page_size;
 926		pg_end[nr_vmas] = vm_end / page_size;
 927		if (++nr_vmas >= MAX_VMAS) {
 928			fprintf(stderr, "too many VMAs\n");
 929			break;
 930		}
 931	}
 932	fclose(file);
 933}
 934
 935static void show_file(const char *name, const struct stat *st)
 936{
 937	unsigned long long size = st->st_size;
 938	char atime[64], mtime[64];
 939	long now = time(NULL);
 940
 941	printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 942			name, (unsigned)st->st_ino,
 943			size, (size + page_size - 1) / page_size);
 944
 945	strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 946	strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 947
 948	printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 949			mtime, now - st->st_mtime,
 950			atime, now - st->st_atime);
 951}
 952
 953static sigjmp_buf sigbus_jmp;
 954
 955static void * volatile sigbus_addr;
 956
 957static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 958{
 959	(void)sig;
 960	(void)ucontex;
 961	sigbus_addr = info ? info->si_addr : NULL;
 962	siglongjmp(sigbus_jmp, 1);
 963}
 964
 965static struct sigaction sigbus_action = {
 966	.sa_sigaction = sigbus_handler,
 967	.sa_flags = SA_SIGINFO,
 968};
 969
 970static void walk_file(const char *name, const struct stat *st)
 971{
 972	uint8_t vec[PAGEMAP_BATCH];
 973	uint64_t buf[PAGEMAP_BATCH], flags;
 974	uint64_t cgroup = 0;
 975	uint64_t mapcnt = 0;
 976	unsigned long nr_pages, pfn, i;
 977	off_t off, end = st->st_size;
 978	int fd;
 979	ssize_t len;
 980	void *ptr;
 981	int first = 1;
 982
 983	fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
 984
 985	for (off = 0; off < end; off += len) {
 986		nr_pages = (end - off + page_size - 1) / page_size;
 987		if (nr_pages > PAGEMAP_BATCH)
 988			nr_pages = PAGEMAP_BATCH;
 989		len = nr_pages * page_size;
 990
 991		ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 992		if (ptr == MAP_FAILED)
 993			fatal("mmap failed: %s", name);
 994
 995		/* determine cached pages */
 996		if (mincore(ptr, len, vec))
 997			fatal("mincore failed: %s", name);
 998
 999		/* turn off readahead */
1000		if (madvise(ptr, len, MADV_RANDOM))
1001			fatal("madvice failed: %s", name);
1002
1003		if (sigsetjmp(sigbus_jmp, 1)) {
1004			end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1005			fprintf(stderr, "got sigbus at offset %lld: %s\n",
1006					(long long)end, name);
1007			goto got_sigbus;
1008		}
1009
1010		/* populate ptes */
1011		for (i = 0; i < nr_pages ; i++) {
1012			if (vec[i] & 1)
1013				(void)*(volatile int *)(ptr + i * page_size);
1014		}
1015got_sigbus:
1016
1017		/* turn off harvesting reference bits */
1018		if (madvise(ptr, len, MADV_SEQUENTIAL))
1019			fatal("madvice failed: %s", name);
1020
1021		if (pagemap_read(buf, (unsigned long)ptr / page_size,
1022					nr_pages) != nr_pages)
1023			fatal("cannot read pagemap");
1024
1025		munmap(ptr, len);
1026
1027		for (i = 0; i < nr_pages; i++) {
1028			pfn = pagemap_pfn(buf[i]);
1029			if (!pfn)
1030				continue;
1031			if (!kpageflags_read(&flags, pfn, 1))
1032				continue;
1033			if (!kpagecgroup_read(&cgroup, pfn, 1))
1034				fatal("kpagecgroup_read failed");
1035			if (!kpagecount_read(&mapcnt, pfn, 1))
1036				fatal("kpagecount_read failed");
1037			if (first && opt_list) {
1038				first = 0;
1039				flush_page_range();
1040				show_file(name, st);
1041			}
1042			add_page(off / page_size + i, pfn,
1043				 flags, cgroup, mapcnt, buf[i]);
1044		}
1045	}
1046
1047	close(fd);
1048}
1049
1050int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1051{
1052	(void)f;
1053	switch (type) {
1054	case FTW_F:
1055		if (S_ISREG(st->st_mode))
1056			walk_file(name, st);
1057		break;
1058	case FTW_DNR:
1059		fprintf(stderr, "cannot read dir: %s\n", name);
1060		break;
1061	}
1062	return 0;
1063}
1064
1065static void walk_page_cache(void)
1066{
1067	struct stat st;
1068
1069	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1070	pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1071	sigaction(SIGBUS, &sigbus_action, NULL);
1072
1073	if (stat(opt_file, &st))
1074		fatal("stat failed: %s\n", opt_file);
1075
1076	if (S_ISREG(st.st_mode)) {
1077		walk_file(opt_file, &st);
1078	} else if (S_ISDIR(st.st_mode)) {
1079		/* do not follow symlinks and mountpoints */
1080		if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1081			fatal("nftw failed: %s\n", opt_file);
1082	} else
1083		fatal("unhandled file type: %s\n", opt_file);
1084
1085	close(kpageflags_fd);
1086	close(pagemap_fd);
1087	signal(SIGBUS, SIG_DFL);
1088}
1089
1090static void parse_file(const char *name)
1091{
1092	opt_file = name;
1093}
1094
1095static void parse_cgroup(const char *path)
1096{
1097	if (path[0] == '@') {
1098		opt_cgroup = parse_number(path + 1);
1099		return;
1100	}
1101
1102	struct stat st;
1103
1104	if (stat(path, &st))
1105		fatal("stat failed: %s: %m\n", path);
1106
1107	if (!S_ISDIR(st.st_mode))
1108		fatal("cgroup supposed to be a directory: %s\n", path);
1109
1110	opt_cgroup = st.st_ino;
1111}
1112
1113static void parse_addr_range(const char *optarg)
1114{
1115	unsigned long offset;
1116	unsigned long size;
1117	char *p;
1118
1119	p = strchr(optarg, ',');
1120	if (!p)
1121		p = strchr(optarg, '+');
1122
1123	if (p == optarg) {
1124		offset = 0;
1125		size   = parse_number(p + 1);
1126	} else if (p) {
1127		offset = parse_number(optarg);
1128		if (p[1] == '\0')
1129			size = ULONG_MAX;
1130		else {
1131			size = parse_number(p + 1);
1132			if (*p == ',') {
1133				if (size < offset)
1134					fatal("invalid range: %lu,%lu\n",
1135							offset, size);
1136				size -= offset;
1137			}
1138		}
1139	} else {
1140		offset = parse_number(optarg);
1141		size   = 1;
1142	}
1143
1144	add_addr_range(offset, size);
1145}
1146
1147static void add_bits_filter(uint64_t mask, uint64_t bits)
1148{
1149	if (nr_bit_filters >= MAX_BIT_FILTERS)
1150		fatal("too much bit filters\n");
1151
1152	opt_mask[nr_bit_filters] = mask;
1153	opt_bits[nr_bit_filters] = bits;
1154	nr_bit_filters++;
1155}
1156
1157static uint64_t parse_flag_name(const char *str, int len)
1158{
1159	size_t i;
1160
1161	if (!*str || !len)
1162		return 0;
1163
1164	if (len <= 8 && !strncmp(str, "compound", len))
1165		return BITS_COMPOUND;
1166
1167	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1168		if (!page_flag_names[i])
1169			continue;
1170		if (!strncmp(str, page_flag_names[i] + 2, len))
1171			return 1ULL << i;
1172	}
1173
1174	return parse_number(str);
1175}
1176
1177static uint64_t parse_flag_names(const char *str, int all)
1178{
1179	const char *p    = str;
1180	uint64_t   flags = 0;
1181
1182	while (1) {
1183		if (*p == ',' || *p == '=' || *p == '\0') {
1184			if ((*str != '~') || (*str == '~' && all && *++str))
1185				flags |= parse_flag_name(str, p - str);
1186			if (*p != ',')
1187				break;
1188			str = p + 1;
1189		}
1190		p++;
1191	}
1192
1193	return flags;
1194}
1195
1196static void parse_bits_mask(const char *optarg)
1197{
1198	uint64_t mask;
1199	uint64_t bits;
1200	const char *p;
1201
1202	p = strchr(optarg, '=');
1203	if (p == optarg) {
1204		mask = KPF_ALL_BITS;
1205		bits = parse_flag_names(p + 1, 0);
1206	} else if (p) {
1207		mask = parse_flag_names(optarg, 0);
1208		bits = parse_flag_names(p + 1, 0);
1209	} else if (strchr(optarg, '~')) {
1210		mask = parse_flag_names(optarg, 1);
1211		bits = parse_flag_names(optarg, 0);
1212	} else {
1213		mask = parse_flag_names(optarg, 0);
1214		bits = KPF_ALL_BITS;
1215	}
1216
1217	add_bits_filter(mask, bits);
1218}
1219
1220static void parse_kpageflags(const char *name)
1221{
1222	opt_kpageflags = name;
1223}
1224
1225static void describe_flags(const char *optarg)
1226{
1227	uint64_t flags = parse_flag_names(optarg, 0);
1228
1229	printf("0x%016llx\t%s\t%s\n",
1230		(unsigned long long)flags,
1231		page_flag_name(flags),
1232		page_flag_longname(flags));
1233}
1234
1235static const struct option opts[] = {
1236	{ "raw"       , 0, NULL, 'r' },
1237	{ "pid"       , 1, NULL, 'p' },
1238	{ "file"      , 1, NULL, 'f' },
1239	{ "addr"      , 1, NULL, 'a' },
1240	{ "bits"      , 1, NULL, 'b' },
1241	{ "cgroup"    , 1, NULL, 'c' },
1242	{ "describe"  , 1, NULL, 'd' },
1243	{ "mark-idle" , 0, NULL, 'i' },
1244	{ "list"      , 0, NULL, 'l' },
1245	{ "list-each" , 0, NULL, 'L' },
1246	{ "list-cgroup", 0, NULL, 'C' },
1247	{ "list-mapcnt", 0, NULL, 'M' },
1248	{ "no-summary", 0, NULL, 'N' },
1249	{ "hwpoison"  , 0, NULL, 'X' },
1250	{ "unpoison"  , 0, NULL, 'x' },
1251	{ "kpageflags", 0, NULL, 'F' },
1252	{ "help"      , 0, NULL, 'h' },
1253	{ NULL        , 0, NULL, 0 }
1254};
1255
1256int main(int argc, char *argv[])
1257{
1258	int c;
1259
1260	page_size = getpagesize();
1261
1262	while ((c = getopt_long(argc, argv,
1263				"rp:f:a:b:d:c:CilLMNXxF:h",
1264				opts, NULL)) != -1) {
1265		switch (c) {
1266		case 'r':
1267			opt_raw = 1;
1268			break;
1269		case 'p':
1270			parse_pid(optarg);
1271			break;
1272		case 'f':
1273			parse_file(optarg);
1274			break;
1275		case 'a':
1276			parse_addr_range(optarg);
1277			break;
1278		case 'b':
1279			parse_bits_mask(optarg);
1280			break;
1281		case 'c':
1282			parse_cgroup(optarg);
1283			break;
1284		case 'C':
1285			opt_list_cgroup = 1;
1286			break;
1287		case 'd':
1288			describe_flags(optarg);
1289			exit(0);
1290		case 'i':
1291			opt_mark_idle = 1;
1292			break;
1293		case 'l':
1294			opt_list = 1;
1295			break;
1296		case 'L':
1297			opt_list = 2;
1298			break;
1299		case 'M':
1300			opt_list_mapcnt = 1;
1301			break;
1302		case 'N':
1303			opt_no_summary = 1;
1304			break;
1305		case 'X':
1306			opt_hwpoison = 1;
1307			prepare_hwpoison_fd();
1308			break;
1309		case 'x':
1310			opt_unpoison = 1;
1311			prepare_hwpoison_fd();
1312			break;
1313		case 'F':
1314			parse_kpageflags(optarg);
1315			break;
1316		case 'h':
1317			usage();
1318			exit(0);
1319		default:
1320			usage();
1321			exit(1);
1322		}
1323	}
1324
1325	if (!opt_kpageflags)
1326		opt_kpageflags = PROC_KPAGEFLAGS;
1327
1328	if (opt_cgroup || opt_list_cgroup)
1329		kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1330
1331	if (opt_list && opt_list_mapcnt)
1332		kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1333
1334	if (opt_mark_idle)
1335		page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1336
1337	if (opt_list && opt_pid)
1338		printf("voffset\t");
1339	if (opt_list && opt_file)
1340		printf("foffset\t");
1341	if (opt_list && opt_list_cgroup)
1342		printf("cgroup\t");
1343	if (opt_list && opt_list_mapcnt)
1344		printf("map-cnt\t");
1345
1346	if (opt_list == 1)
1347		printf("offset\tlen\tflags\n");
1348	if (opt_list == 2)
1349		printf("offset\tflags\n");
1350
1351	if (opt_file)
1352		walk_page_cache();
1353	else
1354		walk_addr_ranges();
1355
1356	if (opt_list == 1)
1357		flush_page_range();
1358
1359	if (opt_no_summary)
1360		return 0;
1361
1362	if (opt_list)
1363		printf("\n\n");
1364
1365	show_summary();
1366
1367	if (opt_list_mapcnt)
1368		close(kpagecount_fd);
1369
1370	if (page_idle_fd >= 0)
1371		close(page_idle_fd);
1372
1373	return 0;
1374}
v5.9
   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
  82/* [48-] take some arbitrary free slots for expanding overloaded flags
  83 * not part of kernel API
  84 */
  85#define KPF_READAHEAD		48
  86#define KPF_SLOB_FREE		49
  87#define KPF_SLUB_FROZEN		50
  88#define KPF_SLUB_DEBUG		51
  89#define KPF_FILE		61
  90#define KPF_SWAP		62
  91#define KPF_MMAP_EXCLUSIVE	63
  92
  93#define KPF_ALL_BITS		((uint64_t)~0ULL)
  94#define KPF_HACKERS_BITS	(0xffffULL << 32)
  95#define KPF_OVERLOADED_BITS	(0xffffULL << 48)
  96#define BIT(name)		(1ULL << KPF_##name)
  97#define BITS_COMPOUND		(BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
  98
  99static const char * const page_flag_names[] = {
 100	[KPF_LOCKED]		= "L:locked",
 101	[KPF_ERROR]		= "E:error",
 102	[KPF_REFERENCED]	= "R:referenced",
 103	[KPF_UPTODATE]		= "U:uptodate",
 104	[KPF_DIRTY]		= "D:dirty",
 105	[KPF_LRU]		= "l:lru",
 106	[KPF_ACTIVE]		= "A:active",
 107	[KPF_SLAB]		= "S:slab",
 108	[KPF_WRITEBACK]		= "W:writeback",
 109	[KPF_RECLAIM]		= "I:reclaim",
 110	[KPF_BUDDY]		= "B:buddy",
 111
 112	[KPF_MMAP]		= "M:mmap",
 113	[KPF_ANON]		= "a:anonymous",
 114	[KPF_SWAPCACHE]		= "s:swapcache",
 115	[KPF_SWAPBACKED]	= "b:swapbacked",
 116	[KPF_COMPOUND_HEAD]	= "H:compound_head",
 117	[KPF_COMPOUND_TAIL]	= "T:compound_tail",
 118	[KPF_HUGE]		= "G:huge",
 119	[KPF_UNEVICTABLE]	= "u:unevictable",
 120	[KPF_HWPOISON]		= "X:hwpoison",
 121	[KPF_NOPAGE]		= "n:nopage",
 122	[KPF_KSM]		= "x:ksm",
 123	[KPF_THP]		= "t:thp",
 124	[KPF_OFFLINE]		= "o:offline",
 125	[KPF_PGTABLE]		= "g:pgtable",
 126	[KPF_ZERO_PAGE]		= "z:zero_page",
 127	[KPF_IDLE]              = "i:idle_page",
 128
 129	[KPF_RESERVED]		= "r:reserved",
 130	[KPF_MLOCKED]		= "m:mlocked",
 131	[KPF_MAPPEDTODISK]	= "d:mappedtodisk",
 132	[KPF_PRIVATE]		= "P:private",
 133	[KPF_PRIVATE_2]		= "p:private_2",
 134	[KPF_OWNER_PRIVATE]	= "O:owner_private",
 135	[KPF_ARCH]		= "h:arch",
 136	[KPF_UNCACHED]		= "c:uncached",
 137	[KPF_SOFTDIRTY]		= "f:softdirty",
 
 138
 139	[KPF_READAHEAD]		= "I:readahead",
 140	[KPF_SLOB_FREE]		= "P:slob_free",
 141	[KPF_SLUB_FROZEN]	= "A:slub_frozen",
 142	[KPF_SLUB_DEBUG]	= "E:slub_debug",
 143
 144	[KPF_FILE]		= "F:file",
 145	[KPF_SWAP]		= "w:swap",
 146	[KPF_MMAP_EXCLUSIVE]	= "1:mmap_exclusive",
 147};
 148
 149
 150/*
 151 * data structures
 152 */
 153
 154static int		opt_raw;	/* for kernel developers */
 155static int		opt_list;	/* list pages (in ranges) */
 156static int		opt_mark_idle;	/* set accessed bit */
 157static int		opt_no_summary;	/* don't show summary */
 158static pid_t		opt_pid;	/* process to walk */
 159const char		*opt_file;	/* file or directory path */
 160static uint64_t		opt_cgroup;	/* cgroup inode */
 161static int		opt_list_cgroup;/* list page cgroup */
 162static int		opt_list_mapcnt;/* list page map count */
 163static const char	*opt_kpageflags;/* kpageflags file to parse */
 164
 165#define MAX_ADDR_RANGES	1024
 166static int		nr_addr_ranges;
 167static unsigned long	opt_offset[MAX_ADDR_RANGES];
 168static unsigned long	opt_size[MAX_ADDR_RANGES];
 169
 170#define MAX_VMAS	10240
 171static int		nr_vmas;
 172static unsigned long	pg_start[MAX_VMAS];
 173static unsigned long	pg_end[MAX_VMAS];
 174
 175#define MAX_BIT_FILTERS	64
 176static int		nr_bit_filters;
 177static uint64_t		opt_mask[MAX_BIT_FILTERS];
 178static uint64_t		opt_bits[MAX_BIT_FILTERS];
 179
 180static int		page_size;
 181
 182static int		pagemap_fd;
 183static int		kpageflags_fd;
 184static int		kpagecount_fd = -1;
 185static int		kpagecgroup_fd = -1;
 186static int		page_idle_fd = -1;
 187
 188static int		opt_hwpoison;
 189static int		opt_unpoison;
 190
 191static const char	*hwpoison_debug_fs;
 192static int		hwpoison_inject_fd;
 193static int		hwpoison_forget_fd;
 194
 195#define HASH_SHIFT	13
 196#define HASH_SIZE	(1 << HASH_SHIFT)
 197#define HASH_MASK	(HASH_SIZE - 1)
 198#define HASH_KEY(flags)	(flags & HASH_MASK)
 199
 200static unsigned long	total_pages;
 201static unsigned long	nr_pages[HASH_SIZE];
 202static uint64_t		page_flags[HASH_SIZE];
 203
 204
 205/*
 206 * helper functions
 207 */
 208
 209#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 210
 211#define min_t(type, x, y) ({			\
 212	type __min1 = (x);			\
 213	type __min2 = (y);			\
 214	__min1 < __min2 ? __min1 : __min2; })
 215
 216#define max_t(type, x, y) ({			\
 217	type __max1 = (x);			\
 218	type __max2 = (y);			\
 219	__max1 > __max2 ? __max1 : __max2; })
 220
 221static unsigned long pages2mb(unsigned long pages)
 222{
 223	return (pages * page_size) >> 20;
 224}
 225
 226static void fatal(const char *x, ...)
 227{
 228	va_list ap;
 229
 230	va_start(ap, x);
 231	vfprintf(stderr, x, ap);
 232	va_end(ap);
 233	exit(EXIT_FAILURE);
 234}
 235
 236static int checked_open(const char *pathname, int flags)
 237{
 238	int fd = open(pathname, flags);
 239
 240	if (fd < 0) {
 241		perror(pathname);
 242		exit(EXIT_FAILURE);
 243	}
 244
 245	return fd;
 246}
 247
 248/*
 249 * pagemap/kpageflags routines
 250 */
 251
 252static unsigned long do_u64_read(int fd, const char *name,
 253				 uint64_t *buf,
 254				 unsigned long index,
 255				 unsigned long count)
 256{
 257	long bytes;
 258
 259	if (index > ULONG_MAX / 8)
 260		fatal("index overflow: %lu\n", index);
 261
 262	bytes = pread(fd, buf, count * 8, (off_t)index * 8);
 263	if (bytes < 0) {
 264		perror(name);
 265		exit(EXIT_FAILURE);
 266	}
 267	if (bytes % 8)
 268		fatal("partial read: %lu bytes\n", bytes);
 269
 270	return bytes / 8;
 271}
 272
 273static unsigned long kpageflags_read(uint64_t *buf,
 274				     unsigned long index,
 275				     unsigned long pages)
 276{
 277	return do_u64_read(kpageflags_fd, opt_kpageflags, buf, index, pages);
 278}
 279
 280static unsigned long kpagecgroup_read(uint64_t *buf,
 281				      unsigned long index,
 282				      unsigned long pages)
 283{
 284	if (kpagecgroup_fd < 0)
 285		return pages;
 286
 287	return do_u64_read(kpagecgroup_fd, opt_kpageflags, buf, index, pages);
 288}
 289
 290static unsigned long kpagecount_read(uint64_t *buf,
 291				     unsigned long index,
 292				     unsigned long pages)
 293{
 294	return kpagecount_fd < 0 ? pages :
 295		do_u64_read(kpagecount_fd, PROC_KPAGECOUNT,
 296			    buf, index, pages);
 297}
 298
 299static 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
 306static 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
 318static unsigned long pagemap_swap_offset(uint64_t val)
 319{
 320	return val & PM_SWAP ? PM_SWAP_OFFSET(val) : 0;
 321}
 322
 323/*
 324 * page flag names
 325 */
 326
 327static char *page_flag_name(uint64_t flags)
 328{
 329	static char buf[65];
 330	int present;
 331	size_t i, j;
 332
 333	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 334		present = (flags >> i) & 1;
 335		if (!page_flag_names[i]) {
 336			if (present)
 337				fatal("unknown flag bit %d\n", i);
 338			continue;
 339		}
 340		buf[j++] = present ? page_flag_names[i][0] : '_';
 341	}
 342
 343	return buf;
 344}
 345
 346static char *page_flag_longname(uint64_t flags)
 347{
 348	static char buf[1024];
 349	size_t i, n;
 350
 351	for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 352		if (!page_flag_names[i])
 353			continue;
 354		if ((flags >> i) & 1)
 355			n += snprintf(buf + n, sizeof(buf) - n, "%s,",
 356					page_flag_names[i] + 2);
 357	}
 358	if (n)
 359		n--;
 360	buf[n] = '\0';
 361
 362	return buf;
 363}
 364
 365
 366/*
 367 * page list and summary
 368 */
 369
 370static void show_page_range(unsigned long voffset, unsigned long offset,
 371			    unsigned long size, uint64_t flags,
 372			    uint64_t cgroup, uint64_t mapcnt)
 373{
 374	static uint64_t      flags0;
 375	static uint64_t	     cgroup0;
 376	static uint64_t      mapcnt0;
 377	static unsigned long voff;
 378	static unsigned long index;
 379	static unsigned long count;
 380
 381	if (flags == flags0 && cgroup == cgroup0 && mapcnt == mapcnt0 &&
 382	    offset == index + count && size && voffset == voff + count) {
 383		count += size;
 384		return;
 385	}
 386
 387	if (count) {
 388		if (opt_pid)
 389			printf("%lx\t", voff);
 390		if (opt_file)
 391			printf("%lu\t", voff);
 392		if (opt_list_cgroup)
 393			printf("@%llu\t", (unsigned long long)cgroup0);
 394		if (opt_list_mapcnt)
 395			printf("%lu\t", mapcnt0);
 396		printf("%lx\t%lx\t%s\n",
 397				index, count, page_flag_name(flags0));
 398	}
 399
 400	flags0 = flags;
 401	cgroup0 = cgroup;
 402	mapcnt0 = mapcnt;
 403	index  = offset;
 404	voff   = voffset;
 405	count  = size;
 406}
 407
 408static void flush_page_range(void)
 409{
 410	show_page_range(0, 0, 0, 0, 0, 0);
 411}
 412
 413static void show_page(unsigned long voffset, unsigned long offset,
 414		      uint64_t flags, uint64_t cgroup, uint64_t mapcnt)
 415{
 416	if (opt_pid)
 417		printf("%lx\t", voffset);
 418	if (opt_file)
 419		printf("%lu\t", voffset);
 420	if (opt_list_cgroup)
 421		printf("@%llu\t", (unsigned long long)cgroup);
 422	if (opt_list_mapcnt)
 423		printf("%lu\t", mapcnt);
 424
 425	printf("%lx\t%s\n", offset, page_flag_name(flags));
 426}
 427
 428static void show_summary(void)
 429{
 430	size_t i;
 431
 432	printf("             flags\tpage-count       MB"
 433		"  symbolic-flags\t\t\tlong-symbolic-flags\n");
 434
 435	for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
 436		if (nr_pages[i])
 437			printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
 438				(unsigned long long)page_flags[i],
 439				nr_pages[i],
 440				pages2mb(nr_pages[i]),
 441				page_flag_name(page_flags[i]),
 442				page_flag_longname(page_flags[i]));
 443	}
 444
 445	printf("             total\t%10lu %8lu\n",
 446			total_pages, pages2mb(total_pages));
 447}
 448
 449
 450/*
 451 * page flag filters
 452 */
 453
 454static int bit_mask_ok(uint64_t flags)
 455{
 456	int i;
 457
 458	for (i = 0; i < nr_bit_filters; i++) {
 459		if (opt_bits[i] == KPF_ALL_BITS) {
 460			if ((flags & opt_mask[i]) == 0)
 461				return 0;
 462		} else {
 463			if ((flags & opt_mask[i]) != opt_bits[i])
 464				return 0;
 465		}
 466	}
 467
 468	return 1;
 469}
 470
 471static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
 472{
 473	/* SLOB/SLUB overload several page flags */
 474	if (flags & BIT(SLAB)) {
 475		if (flags & BIT(PRIVATE))
 476			flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
 477		if (flags & BIT(ACTIVE))
 478			flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
 479		if (flags & BIT(ERROR))
 480			flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
 481	}
 482
 483	/* PG_reclaim is overloaded as PG_readahead in the read path */
 484	if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
 485		flags ^= BIT(RECLAIM) | BIT(READAHEAD);
 486
 487	if (pme & PM_SOFT_DIRTY)
 488		flags |= BIT(SOFTDIRTY);
 489	if (pme & PM_FILE)
 490		flags |= BIT(FILE);
 491	if (pme & PM_SWAP)
 492		flags |= BIT(SWAP);
 493	if (pme & PM_MMAP_EXCLUSIVE)
 494		flags |= BIT(MMAP_EXCLUSIVE);
 495
 496	return flags;
 497}
 498
 499static uint64_t well_known_flags(uint64_t flags)
 500{
 501	/* hide flags intended only for kernel hacker */
 502	flags &= ~KPF_HACKERS_BITS;
 503
 504	/* hide non-hugeTLB compound pages */
 505	if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
 506		flags &= ~BITS_COMPOUND;
 507
 508	return flags;
 509}
 510
 511static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
 512{
 513	if (opt_raw)
 514		flags = expand_overloaded_flags(flags, pme);
 515	else
 516		flags = well_known_flags(flags);
 517
 518	return flags;
 519}
 520
 521/*
 522 * page actions
 523 */
 524
 525static void prepare_hwpoison_fd(void)
 526{
 527	char buf[MAX_PATH + 1];
 528
 529	hwpoison_debug_fs = debugfs__mount();
 530	if (!hwpoison_debug_fs) {
 531		perror("mount debugfs");
 532		exit(EXIT_FAILURE);
 533	}
 534
 535	if (opt_hwpoison && !hwpoison_inject_fd) {
 536		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",
 537			hwpoison_debug_fs);
 538		hwpoison_inject_fd = checked_open(buf, O_WRONLY);
 539	}
 540
 541	if (opt_unpoison && !hwpoison_forget_fd) {
 542		snprintf(buf, MAX_PATH, "%s/hwpoison/unpoison-pfn",
 543			hwpoison_debug_fs);
 544		hwpoison_forget_fd = checked_open(buf, O_WRONLY);
 545	}
 546}
 547
 548static int hwpoison_page(unsigned long offset)
 549{
 550	char buf[100];
 551	int len;
 552
 553	len = sprintf(buf, "0x%lx\n", offset);
 554	len = write(hwpoison_inject_fd, buf, len);
 555	if (len < 0) {
 556		perror("hwpoison inject");
 557		return len;
 558	}
 559	return 0;
 560}
 561
 562static int unpoison_page(unsigned long offset)
 563{
 564	char buf[100];
 565	int len;
 566
 567	len = sprintf(buf, "0x%lx\n", offset);
 568	len = write(hwpoison_forget_fd, buf, len);
 569	if (len < 0) {
 570		perror("hwpoison forget");
 571		return len;
 572	}
 573	return 0;
 574}
 575
 576static int mark_page_idle(unsigned long offset)
 577{
 578	static unsigned long off;
 579	static uint64_t buf;
 580	int len;
 581
 582	if ((offset / 64 == off / 64) || buf == 0) {
 583		buf |= 1UL << (offset % 64);
 584		off = offset;
 585		return 0;
 586	}
 587
 588	len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64));
 589	if (len < 0) {
 590		perror("mark page idle");
 591		return len;
 592	}
 593
 594	buf = 1UL << (offset % 64);
 595	off = offset;
 596
 597	return 0;
 598}
 599
 600/*
 601 * page frame walker
 602 */
 603
 604static size_t hash_slot(uint64_t flags)
 605{
 606	size_t k = HASH_KEY(flags);
 607	size_t i;
 608
 609	/* Explicitly reserve slot 0 for flags 0: the following logic
 610	 * cannot distinguish an unoccupied slot from slot (flags==0).
 611	 */
 612	if (flags == 0)
 613		return 0;
 614
 615	/* search through the remaining (HASH_SIZE-1) slots */
 616	for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
 617		if (!k || k >= ARRAY_SIZE(page_flags))
 618			k = 1;
 619		if (page_flags[k] == 0) {
 620			page_flags[k] = flags;
 621			return k;
 622		}
 623		if (page_flags[k] == flags)
 624			return k;
 625	}
 626
 627	fatal("hash table full: bump up HASH_SHIFT?\n");
 628	exit(EXIT_FAILURE);
 629}
 630
 631static void add_page(unsigned long voffset, unsigned long offset,
 632		     uint64_t flags, uint64_t cgroup, uint64_t mapcnt,
 633		     uint64_t pme)
 634{
 635	flags = kpageflags_flags(flags, pme);
 636
 637	if (!bit_mask_ok(flags))
 638		return;
 639
 640	if (opt_cgroup && cgroup != (uint64_t)opt_cgroup)
 641		return;
 642
 643	if (opt_hwpoison)
 644		hwpoison_page(offset);
 645	if (opt_unpoison)
 646		unpoison_page(offset);
 647
 648	if (opt_mark_idle)
 649		mark_page_idle(offset);
 650
 651	if (opt_list == 1)
 652		show_page_range(voffset, offset, 1, flags, cgroup, mapcnt);
 653	else if (opt_list == 2)
 654		show_page(voffset, offset, flags, cgroup, mapcnt);
 655
 656	nr_pages[hash_slot(flags)]++;
 657	total_pages++;
 658}
 659
 660#define KPAGEFLAGS_BATCH	(64 << 10)	/* 64k pages */
 661static void walk_pfn(unsigned long voffset,
 662		     unsigned long index,
 663		     unsigned long count,
 664		     uint64_t pme)
 665{
 666	uint64_t buf[KPAGEFLAGS_BATCH];
 667	uint64_t cgi[KPAGEFLAGS_BATCH];
 668	uint64_t cnt[KPAGEFLAGS_BATCH];
 669	unsigned long batch;
 670	unsigned long pages;
 671	unsigned long i;
 672
 673	/*
 674	 * kpagecgroup_read() reads only if kpagecgroup were opened, but
 675	 * /proc/kpagecgroup might even not exist, so it's better to fill
 676	 * them with zeros here.
 677	 */
 678	if (count == 1)
 679		cgi[0] = 0;
 680	else
 681		memset(cgi, 0, sizeof cgi);
 682
 683	while (count) {
 684		batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
 685		pages = kpageflags_read(buf, index, batch);
 686		if (pages == 0)
 687			break;
 688
 689		if (kpagecgroup_read(cgi, index, pages) != pages)
 690			fatal("kpagecgroup returned fewer pages than expected");
 691
 692		if (kpagecount_read(cnt, index, pages) != pages)
 693			fatal("kpagecount returned fewer pages than expected");
 694
 695		for (i = 0; i < pages; i++)
 696			add_page(voffset + i, index + i,
 697				 buf[i], cgi[i], cnt[i], pme);
 698
 699		index += pages;
 700		count -= pages;
 701	}
 702}
 703
 704static void walk_swap(unsigned long voffset, uint64_t pme)
 705{
 706	uint64_t flags = kpageflags_flags(0, pme);
 707
 708	if (!bit_mask_ok(flags))
 709		return;
 710
 711	if (opt_cgroup)
 712		return;
 713
 714	if (opt_list == 1)
 715		show_page_range(voffset, pagemap_swap_offset(pme),
 716				1, flags, 0, 0);
 717	else if (opt_list == 2)
 718		show_page(voffset, pagemap_swap_offset(pme), flags, 0, 0);
 719
 720	nr_pages[hash_slot(flags)]++;
 721	total_pages++;
 722}
 723
 724#define PAGEMAP_BATCH	(64 << 10)
 725static void walk_vma(unsigned long index, unsigned long count)
 726{
 727	uint64_t buf[PAGEMAP_BATCH];
 728	unsigned long batch;
 729	unsigned long pages;
 730	unsigned long pfn;
 731	unsigned long i;
 732
 733	while (count) {
 734		batch = min_t(unsigned long, count, PAGEMAP_BATCH);
 735		pages = pagemap_read(buf, index, batch);
 736		if (pages == 0)
 737			break;
 738
 739		for (i = 0; i < pages; i++) {
 740			pfn = pagemap_pfn(buf[i]);
 741			if (pfn)
 742				walk_pfn(index + i, pfn, 1, buf[i]);
 743			if (buf[i] & PM_SWAP)
 744				walk_swap(index + i, buf[i]);
 745		}
 746
 747		index += pages;
 748		count -= pages;
 749	}
 750}
 751
 752static void walk_task(unsigned long index, unsigned long count)
 753{
 754	const unsigned long end = index + count;
 755	unsigned long start;
 756	int i = 0;
 757
 758	while (index < end) {
 759
 760		while (pg_end[i] <= index)
 761			if (++i >= nr_vmas)
 762				return;
 763		if (pg_start[i] >= end)
 764			return;
 765
 766		start = max_t(unsigned long, pg_start[i], index);
 767		index = min_t(unsigned long, pg_end[i], end);
 768
 769		assert(start < index);
 770		walk_vma(start, index - start);
 771	}
 772}
 773
 774static void add_addr_range(unsigned long offset, unsigned long size)
 775{
 776	if (nr_addr_ranges >= MAX_ADDR_RANGES)
 777		fatal("too many addr ranges\n");
 778
 779	opt_offset[nr_addr_ranges] = offset;
 780	opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
 781	nr_addr_ranges++;
 782}
 783
 784static void walk_addr_ranges(void)
 785{
 786	int i;
 787
 788	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
 789
 790	if (!nr_addr_ranges)
 791		add_addr_range(0, ULONG_MAX);
 792
 793	for (i = 0; i < nr_addr_ranges; i++)
 794		if (!opt_pid)
 795			walk_pfn(opt_offset[i], opt_offset[i], opt_size[i], 0);
 796		else
 797			walk_task(opt_offset[i], opt_size[i]);
 798
 799	if (opt_mark_idle)
 800		mark_page_idle(0);
 801
 802	close(kpageflags_fd);
 803}
 804
 805
 806/*
 807 * user interface
 808 */
 809
 810static const char *page_flag_type(uint64_t flag)
 811{
 812	if (flag & KPF_HACKERS_BITS)
 813		return "(r)";
 814	if (flag & KPF_OVERLOADED_BITS)
 815		return "(o)";
 816	return "   ";
 817}
 818
 819static void usage(void)
 820{
 821	size_t i, j;
 822
 823	printf(
 824"page-types [options]\n"
 825"            -r|--raw                   Raw mode, for kernel developers\n"
 826"            -d|--describe flags        Describe flags\n"
 827"            -a|--addr    addr-spec     Walk a range of pages\n"
 828"            -b|--bits    bits-spec     Walk pages with specified bits\n"
 829"            -c|--cgroup  path|@inode   Walk pages within memory cgroup\n"
 830"            -p|--pid     pid           Walk process address space\n"
 831"            -f|--file    filename      Walk file address space\n"
 832"            -i|--mark-idle             Mark pages idle\n"
 833"            -l|--list                  Show page details in ranges\n"
 834"            -L|--list-each             Show page details one by one\n"
 835"            -C|--list-cgroup           Show cgroup inode for pages\n"
 836"            -M|--list-mapcnt           Show page map count\n"
 837"            -N|--no-summary            Don't show summary info\n"
 838"            -X|--hwpoison              hwpoison pages\n"
 839"            -x|--unpoison              unpoison pages\n"
 840"            -F|--kpageflags filename   kpageflags file to parse\n"
 841"            -h|--help                  Show this usage message\n"
 842"flags:\n"
 843"            0x10                       bitfield format, e.g.\n"
 844"            anon                       bit-name, e.g.\n"
 845"            0x10,anon                  comma-separated list, e.g.\n"
 846"addr-spec:\n"
 847"            N                          one page at offset N (unit: pages)\n"
 848"            N+M                        pages range from N to N+M-1\n"
 849"            N,M                        pages range from N to M-1\n"
 850"            N,                         pages range from N to end\n"
 851"            ,M                         pages range from 0 to M-1\n"
 852"bits-spec:\n"
 853"            bit1,bit2                  (flags & (bit1|bit2)) != 0\n"
 854"            bit1,bit2=bit1             (flags & (bit1|bit2)) == bit1\n"
 855"            bit1,~bit2                 (flags & (bit1|bit2)) == bit1\n"
 856"            =bit1,bit2                 flags == (bit1|bit2)\n"
 857"bit-names:\n"
 858	);
 859
 860	for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
 861		if (!page_flag_names[i])
 862			continue;
 863		printf("%16s%s", page_flag_names[i] + 2,
 864				 page_flag_type(1ULL << i));
 865		if (++j > 3) {
 866			j = 0;
 867			putchar('\n');
 868		}
 869	}
 870	printf("\n                                   "
 871		"(r) raw mode bits  (o) overloaded bits\n");
 872}
 873
 874static unsigned long long parse_number(const char *str)
 875{
 876	unsigned long long n;
 877
 878	n = strtoll(str, NULL, 0);
 879
 880	if (n == 0 && str[0] != '0')
 881		fatal("invalid name or number: %s\n", str);
 882
 883	return n;
 884}
 885
 886static void parse_pid(const char *str)
 887{
 888	FILE *file;
 889	char buf[5000];
 890
 891	opt_pid = parse_number(str);
 892
 893	sprintf(buf, "/proc/%d/pagemap", opt_pid);
 894	pagemap_fd = checked_open(buf, O_RDONLY);
 895
 896	sprintf(buf, "/proc/%d/maps", opt_pid);
 897	file = fopen(buf, "r");
 898	if (!file) {
 899		perror(buf);
 900		exit(EXIT_FAILURE);
 901	}
 902
 903	while (fgets(buf, sizeof(buf), file) != NULL) {
 904		unsigned long vm_start;
 905		unsigned long vm_end;
 906		unsigned long long pgoff;
 907		int major, minor;
 908		char r, w, x, s;
 909		unsigned long ino;
 910		int n;
 911
 912		n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
 913			   &vm_start,
 914			   &vm_end,
 915			   &r, &w, &x, &s,
 916			   &pgoff,
 917			   &major, &minor,
 918			   &ino);
 919		if (n < 10) {
 920			fprintf(stderr, "unexpected line: %s\n", buf);
 921			continue;
 922		}
 923		pg_start[nr_vmas] = vm_start / page_size;
 924		pg_end[nr_vmas] = vm_end / page_size;
 925		if (++nr_vmas >= MAX_VMAS) {
 926			fprintf(stderr, "too many VMAs\n");
 927			break;
 928		}
 929	}
 930	fclose(file);
 931}
 932
 933static void show_file(const char *name, const struct stat *st)
 934{
 935	unsigned long long size = st->st_size;
 936	char atime[64], mtime[64];
 937	long now = time(NULL);
 938
 939	printf("%s\tInode: %u\tSize: %llu (%llu pages)\n",
 940			name, (unsigned)st->st_ino,
 941			size, (size + page_size - 1) / page_size);
 942
 943	strftime(atime, sizeof(atime), "%c", localtime(&st->st_atime));
 944	strftime(mtime, sizeof(mtime), "%c", localtime(&st->st_mtime));
 945
 946	printf("Modify: %s (%ld seconds ago)\nAccess: %s (%ld seconds ago)\n",
 947			mtime, now - st->st_mtime,
 948			atime, now - st->st_atime);
 949}
 950
 951static sigjmp_buf sigbus_jmp;
 952
 953static void * volatile sigbus_addr;
 954
 955static void sigbus_handler(int sig, siginfo_t *info, void *ucontex)
 956{
 957	(void)sig;
 958	(void)ucontex;
 959	sigbus_addr = info ? info->si_addr : NULL;
 960	siglongjmp(sigbus_jmp, 1);
 961}
 962
 963static struct sigaction sigbus_action = {
 964	.sa_sigaction = sigbus_handler,
 965	.sa_flags = SA_SIGINFO,
 966};
 967
 968static void walk_file(const char *name, const struct stat *st)
 969{
 970	uint8_t vec[PAGEMAP_BATCH];
 971	uint64_t buf[PAGEMAP_BATCH], flags;
 972	uint64_t cgroup = 0;
 973	uint64_t mapcnt = 0;
 974	unsigned long nr_pages, pfn, i;
 975	off_t off, end = st->st_size;
 976	int fd;
 977	ssize_t len;
 978	void *ptr;
 979	int first = 1;
 980
 981	fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW);
 982
 983	for (off = 0; off < end; off += len) {
 984		nr_pages = (end - off + page_size - 1) / page_size;
 985		if (nr_pages > PAGEMAP_BATCH)
 986			nr_pages = PAGEMAP_BATCH;
 987		len = nr_pages * page_size;
 988
 989		ptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, off);
 990		if (ptr == MAP_FAILED)
 991			fatal("mmap failed: %s", name);
 992
 993		/* determine cached pages */
 994		if (mincore(ptr, len, vec))
 995			fatal("mincore failed: %s", name);
 996
 997		/* turn off readahead */
 998		if (madvise(ptr, len, MADV_RANDOM))
 999			fatal("madvice failed: %s", name);
1000
1001		if (sigsetjmp(sigbus_jmp, 1)) {
1002			end = off + sigbus_addr ? sigbus_addr - ptr : 0;
1003			fprintf(stderr, "got sigbus at offset %lld: %s\n",
1004					(long long)end, name);
1005			goto got_sigbus;
1006		}
1007
1008		/* populate ptes */
1009		for (i = 0; i < nr_pages ; i++) {
1010			if (vec[i] & 1)
1011				(void)*(volatile int *)(ptr + i * page_size);
1012		}
1013got_sigbus:
1014
1015		/* turn off harvesting reference bits */
1016		if (madvise(ptr, len, MADV_SEQUENTIAL))
1017			fatal("madvice failed: %s", name);
1018
1019		if (pagemap_read(buf, (unsigned long)ptr / page_size,
1020					nr_pages) != nr_pages)
1021			fatal("cannot read pagemap");
1022
1023		munmap(ptr, len);
1024
1025		for (i = 0; i < nr_pages; i++) {
1026			pfn = pagemap_pfn(buf[i]);
1027			if (!pfn)
1028				continue;
1029			if (!kpageflags_read(&flags, pfn, 1))
1030				continue;
1031			if (!kpagecgroup_read(&cgroup, pfn, 1))
1032				fatal("kpagecgroup_read failed");
1033			if (!kpagecount_read(&mapcnt, pfn, 1))
1034				fatal("kpagecount_read failed");
1035			if (first && opt_list) {
1036				first = 0;
1037				flush_page_range();
1038				show_file(name, st);
1039			}
1040			add_page(off / page_size + i, pfn,
1041				 flags, cgroup, mapcnt, buf[i]);
1042		}
1043	}
1044
1045	close(fd);
1046}
1047
1048int walk_tree(const char *name, const struct stat *st, int type, struct FTW *f)
1049{
1050	(void)f;
1051	switch (type) {
1052	case FTW_F:
1053		if (S_ISREG(st->st_mode))
1054			walk_file(name, st);
1055		break;
1056	case FTW_DNR:
1057		fprintf(stderr, "cannot read dir: %s\n", name);
1058		break;
1059	}
1060	return 0;
1061}
1062
1063static void walk_page_cache(void)
1064{
1065	struct stat st;
1066
1067	kpageflags_fd = checked_open(opt_kpageflags, O_RDONLY);
1068	pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY);
1069	sigaction(SIGBUS, &sigbus_action, NULL);
1070
1071	if (stat(opt_file, &st))
1072		fatal("stat failed: %s\n", opt_file);
1073
1074	if (S_ISREG(st.st_mode)) {
1075		walk_file(opt_file, &st);
1076	} else if (S_ISDIR(st.st_mode)) {
1077		/* do not follow symlinks and mountpoints */
1078		if (nftw(opt_file, walk_tree, 64, FTW_MOUNT | FTW_PHYS) < 0)
1079			fatal("nftw failed: %s\n", opt_file);
1080	} else
1081		fatal("unhandled file type: %s\n", opt_file);
1082
1083	close(kpageflags_fd);
1084	close(pagemap_fd);
1085	signal(SIGBUS, SIG_DFL);
1086}
1087
1088static void parse_file(const char *name)
1089{
1090	opt_file = name;
1091}
1092
1093static void parse_cgroup(const char *path)
1094{
1095	if (path[0] == '@') {
1096		opt_cgroup = parse_number(path + 1);
1097		return;
1098	}
1099
1100	struct stat st;
1101
1102	if (stat(path, &st))
1103		fatal("stat failed: %s: %m\n", path);
1104
1105	if (!S_ISDIR(st.st_mode))
1106		fatal("cgroup supposed to be a directory: %s\n", path);
1107
1108	opt_cgroup = st.st_ino;
1109}
1110
1111static void parse_addr_range(const char *optarg)
1112{
1113	unsigned long offset;
1114	unsigned long size;
1115	char *p;
1116
1117	p = strchr(optarg, ',');
1118	if (!p)
1119		p = strchr(optarg, '+');
1120
1121	if (p == optarg) {
1122		offset = 0;
1123		size   = parse_number(p + 1);
1124	} else if (p) {
1125		offset = parse_number(optarg);
1126		if (p[1] == '\0')
1127			size = ULONG_MAX;
1128		else {
1129			size = parse_number(p + 1);
1130			if (*p == ',') {
1131				if (size < offset)
1132					fatal("invalid range: %lu,%lu\n",
1133							offset, size);
1134				size -= offset;
1135			}
1136		}
1137	} else {
1138		offset = parse_number(optarg);
1139		size   = 1;
1140	}
1141
1142	add_addr_range(offset, size);
1143}
1144
1145static void add_bits_filter(uint64_t mask, uint64_t bits)
1146{
1147	if (nr_bit_filters >= MAX_BIT_FILTERS)
1148		fatal("too much bit filters\n");
1149
1150	opt_mask[nr_bit_filters] = mask;
1151	opt_bits[nr_bit_filters] = bits;
1152	nr_bit_filters++;
1153}
1154
1155static uint64_t parse_flag_name(const char *str, int len)
1156{
1157	size_t i;
1158
1159	if (!*str || !len)
1160		return 0;
1161
1162	if (len <= 8 && !strncmp(str, "compound", len))
1163		return BITS_COMPOUND;
1164
1165	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
1166		if (!page_flag_names[i])
1167			continue;
1168		if (!strncmp(str, page_flag_names[i] + 2, len))
1169			return 1ULL << i;
1170	}
1171
1172	return parse_number(str);
1173}
1174
1175static uint64_t parse_flag_names(const char *str, int all)
1176{
1177	const char *p    = str;
1178	uint64_t   flags = 0;
1179
1180	while (1) {
1181		if (*p == ',' || *p == '=' || *p == '\0') {
1182			if ((*str != '~') || (*str == '~' && all && *++str))
1183				flags |= parse_flag_name(str, p - str);
1184			if (*p != ',')
1185				break;
1186			str = p + 1;
1187		}
1188		p++;
1189	}
1190
1191	return flags;
1192}
1193
1194static void parse_bits_mask(const char *optarg)
1195{
1196	uint64_t mask;
1197	uint64_t bits;
1198	const char *p;
1199
1200	p = strchr(optarg, '=');
1201	if (p == optarg) {
1202		mask = KPF_ALL_BITS;
1203		bits = parse_flag_names(p + 1, 0);
1204	} else if (p) {
1205		mask = parse_flag_names(optarg, 0);
1206		bits = parse_flag_names(p + 1, 0);
1207	} else if (strchr(optarg, '~')) {
1208		mask = parse_flag_names(optarg, 1);
1209		bits = parse_flag_names(optarg, 0);
1210	} else {
1211		mask = parse_flag_names(optarg, 0);
1212		bits = KPF_ALL_BITS;
1213	}
1214
1215	add_bits_filter(mask, bits);
1216}
1217
1218static void parse_kpageflags(const char *name)
1219{
1220	opt_kpageflags = name;
1221}
1222
1223static void describe_flags(const char *optarg)
1224{
1225	uint64_t flags = parse_flag_names(optarg, 0);
1226
1227	printf("0x%016llx\t%s\t%s\n",
1228		(unsigned long long)flags,
1229		page_flag_name(flags),
1230		page_flag_longname(flags));
1231}
1232
1233static const struct option opts[] = {
1234	{ "raw"       , 0, NULL, 'r' },
1235	{ "pid"       , 1, NULL, 'p' },
1236	{ "file"      , 1, NULL, 'f' },
1237	{ "addr"      , 1, NULL, 'a' },
1238	{ "bits"      , 1, NULL, 'b' },
1239	{ "cgroup"    , 1, NULL, 'c' },
1240	{ "describe"  , 1, NULL, 'd' },
1241	{ "mark-idle" , 0, NULL, 'i' },
1242	{ "list"      , 0, NULL, 'l' },
1243	{ "list-each" , 0, NULL, 'L' },
1244	{ "list-cgroup", 0, NULL, 'C' },
1245	{ "list-mapcnt", 0, NULL, 'M' },
1246	{ "no-summary", 0, NULL, 'N' },
1247	{ "hwpoison"  , 0, NULL, 'X' },
1248	{ "unpoison"  , 0, NULL, 'x' },
1249	{ "kpageflags", 0, NULL, 'F' },
1250	{ "help"      , 0, NULL, 'h' },
1251	{ NULL        , 0, NULL, 0 }
1252};
1253
1254int main(int argc, char *argv[])
1255{
1256	int c;
1257
1258	page_size = getpagesize();
1259
1260	while ((c = getopt_long(argc, argv,
1261				"rp:f:a:b:d:c:CilLMNXxF:h",
1262				opts, NULL)) != -1) {
1263		switch (c) {
1264		case 'r':
1265			opt_raw = 1;
1266			break;
1267		case 'p':
1268			parse_pid(optarg);
1269			break;
1270		case 'f':
1271			parse_file(optarg);
1272			break;
1273		case 'a':
1274			parse_addr_range(optarg);
1275			break;
1276		case 'b':
1277			parse_bits_mask(optarg);
1278			break;
1279		case 'c':
1280			parse_cgroup(optarg);
1281			break;
1282		case 'C':
1283			opt_list_cgroup = 1;
1284			break;
1285		case 'd':
1286			describe_flags(optarg);
1287			exit(0);
1288		case 'i':
1289			opt_mark_idle = 1;
1290			break;
1291		case 'l':
1292			opt_list = 1;
1293			break;
1294		case 'L':
1295			opt_list = 2;
1296			break;
1297		case 'M':
1298			opt_list_mapcnt = 1;
1299			break;
1300		case 'N':
1301			opt_no_summary = 1;
1302			break;
1303		case 'X':
1304			opt_hwpoison = 1;
1305			prepare_hwpoison_fd();
1306			break;
1307		case 'x':
1308			opt_unpoison = 1;
1309			prepare_hwpoison_fd();
1310			break;
1311		case 'F':
1312			parse_kpageflags(optarg);
1313			break;
1314		case 'h':
1315			usage();
1316			exit(0);
1317		default:
1318			usage();
1319			exit(1);
1320		}
1321	}
1322
1323	if (!opt_kpageflags)
1324		opt_kpageflags = PROC_KPAGEFLAGS;
1325
1326	if (opt_cgroup || opt_list_cgroup)
1327		kpagecgroup_fd = checked_open(PROC_KPAGECGROUP, O_RDONLY);
1328
1329	if (opt_list && opt_list_mapcnt)
1330		kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY);
1331
1332	if (opt_mark_idle && opt_file)
1333		page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR);
1334
1335	if (opt_list && opt_pid)
1336		printf("voffset\t");
1337	if (opt_list && opt_file)
1338		printf("foffset\t");
1339	if (opt_list && opt_list_cgroup)
1340		printf("cgroup\t");
1341	if (opt_list && opt_list_mapcnt)
1342		printf("map-cnt\t");
1343
1344	if (opt_list == 1)
1345		printf("offset\tlen\tflags\n");
1346	if (opt_list == 2)
1347		printf("offset\tflags\n");
1348
1349	if (opt_file)
1350		walk_page_cache();
1351	else
1352		walk_addr_ranges();
1353
1354	if (opt_list == 1)
1355		flush_page_range();
1356
1357	if (opt_no_summary)
1358		return 0;
1359
1360	if (opt_list)
1361		printf("\n\n");
1362
1363	show_summary();
1364
1365	if (opt_list_mapcnt)
1366		close(kpagecount_fd);
1367
1368	if (page_idle_fd >= 0)
1369		close(page_idle_fd);
1370
1371	return 0;
1372}