1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/pagewalk.h>
   3#include <linux/vmacache.h>
   4#include <linux/hugetlb.h>
   5#include <linux/huge_mm.h>
   6#include <linux/mount.h>
   7#include <linux/seq_file.h>
   8#include <linux/highmem.h>
   9#include <linux/ptrace.h>
  10#include <linux/slab.h>
  11#include <linux/pagemap.h>
  12#include <linux/mempolicy.h>
  13#include <linux/rmap.h>
  14#include <linux/swap.h>
  15#include <linux/sched/mm.h>
  16#include <linux/swapops.h>
  17#include <linux/mmu_notifier.h>
  18#include <linux/page_idle.h>
  19#include <linux/shmem_fs.h>
  20#include <linux/uaccess.h>
  21#include <linux/pkeys.h>
  22
  23#include <asm/elf.h>
  24#include <asm/tlb.h>
  25#include <asm/tlbflush.h>
  26#include "internal.h"
  27
  28#define SEQ_PUT_DEC(str, val) \
  29		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
  30void task_mem(struct seq_file *m, struct mm_struct *mm)
  31{
  32	unsigned long text, lib, swap, anon, file, shmem;
  33	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  34
  35	anon = get_mm_counter(mm, MM_ANONPAGES);
  36	file = get_mm_counter(mm, MM_FILEPAGES);
  37	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
  38
  39	/*
  40	 * Note: to minimize their overhead, mm maintains hiwater_vm and
  41	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
  42	 * collector of these hiwater stats must therefore get total_vm
  43	 * and rss too, which will usually be the higher.  Barriers? not
  44	 * worth the effort, such snapshots can always be inconsistent.
  45	 */
  46	hiwater_vm = total_vm = mm->total_vm;
  47	if (hiwater_vm < mm->hiwater_vm)
  48		hiwater_vm = mm->hiwater_vm;
  49	hiwater_rss = total_rss = anon + file + shmem;
  50	if (hiwater_rss < mm->hiwater_rss)
  51		hiwater_rss = mm->hiwater_rss;
  52
  53	/* split executable areas between text and lib */
  54	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
  55	text = min(text, mm->exec_vm << PAGE_SHIFT);
  56	lib = (mm->exec_vm << PAGE_SHIFT) - text;
  57
  58	swap = get_mm_counter(mm, MM_SWAPENTS);
  59	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
  60	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
  61	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
  62	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
  63	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
  64	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
  65	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
  66	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
  67	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
  68	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
  69	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
  70	seq_put_decimal_ull_width(m,
  71		    " kB\nVmExe:\t", text >> 10, 8);
  72	seq_put_decimal_ull_width(m,
  73		    " kB\nVmLib:\t", lib >> 10, 8);
  74	seq_put_decimal_ull_width(m,
  75		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
  76	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
  77	seq_puts(m, " kB\n");
  78	hugetlb_report_usage(m, mm);
  79}
  80#undef SEQ_PUT_DEC
  81
  82unsigned long task_vsize(struct mm_struct *mm)
  83{
  84	return PAGE_SIZE * mm->total_vm;
  85}
  86
  87unsigned long task_statm(struct mm_struct *mm,
  88			 unsigned long *shared, unsigned long *text,
  89			 unsigned long *data, unsigned long *resident)
  90{
  91	*shared = get_mm_counter(mm, MM_FILEPAGES) +
  92			get_mm_counter(mm, MM_SHMEMPAGES);
  93	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  94								>> PAGE_SHIFT;
  95	*data = mm->data_vm + mm->stack_vm;
  96	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
  97	return mm->total_vm;
  98}
  99
 100#ifdef CONFIG_NUMA
 101/*
 102 * Save get_task_policy() for show_numa_map().
 103 */
 104static void hold_task_mempolicy(struct proc_maps_private *priv)
 105{
 106	struct task_struct *task = priv->task;
 107
 108	task_lock(task);
 109	priv->task_mempolicy = get_task_policy(task);
 110	mpol_get(priv->task_mempolicy);
 111	task_unlock(task);
 112}
 113static void release_task_mempolicy(struct proc_maps_private *priv)
 114{
 115	mpol_put(priv->task_mempolicy);
 116}
 117#else
 118static void hold_task_mempolicy(struct proc_maps_private *priv)
 119{
 120}
 121static void release_task_mempolicy(struct proc_maps_private *priv)
 122{
 123}
 124#endif
 125
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 126static void *m_start(struct seq_file *m, loff_t *ppos)
 127{
 128	struct proc_maps_private *priv = m->private;
 129	unsigned long last_addr = *ppos;
 130	struct mm_struct *mm;
 131	struct vm_area_struct *vma;
 
 132
 133	/* See m_next(). Zero at the start or after lseek. */
 134	if (last_addr == -1UL)
 135		return NULL;
 136
 137	priv->task = get_proc_task(priv->inode);
 138	if (!priv->task)
 139		return ERR_PTR(-ESRCH);
 140
 141	mm = priv->mm;
 142	if (!mm || !mmget_not_zero(mm)) {
 143		put_task_struct(priv->task);
 144		priv->task = NULL;
 145		return NULL;
 146	}
 147
 148	if (mmap_read_lock_killable(mm)) {
 149		mmput(mm);
 150		put_task_struct(priv->task);
 151		priv->task = NULL;
 152		return ERR_PTR(-EINTR);
 153	}
 154
 155	hold_task_mempolicy(priv);
 156	priv->tail_vma = get_gate_vma(mm);
 157
 158	vma = find_vma(mm, last_addr);
 159	if (vma)
 
 
 
 
 
 
 
 
 
 
 
 
 160		return vma;
 
 161
 162	return priv->tail_vma;
 
 
 
 
 
 163}
 164
 165static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
 166{
 167	struct proc_maps_private *priv = m->private;
 168	struct vm_area_struct *next, *vma = v;
 169
 170	if (vma == priv->tail_vma)
 171		next = NULL;
 172	else if (vma->vm_next)
 173		next = vma->vm_next;
 174	else
 175		next = priv->tail_vma;
 176
 177	*ppos = next ? next->vm_start : -1UL;
 178
 
 
 
 
 179	return next;
 180}
 181
 182static void m_stop(struct seq_file *m, void *v)
 183{
 184	struct proc_maps_private *priv = m->private;
 185	struct mm_struct *mm = priv->mm;
 186
 187	if (!priv->task)
 188		return;
 189
 190	release_task_mempolicy(priv);
 191	mmap_read_unlock(mm);
 192	mmput(mm);
 193	put_task_struct(priv->task);
 194	priv->task = NULL;
 
 195}
 196
 197static int proc_maps_open(struct inode *inode, struct file *file,
 198			const struct seq_operations *ops, int psize)
 199{
 200	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
 201
 202	if (!priv)
 203		return -ENOMEM;
 204
 205	priv->inode = inode;
 206	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 207	if (IS_ERR(priv->mm)) {
 208		int err = PTR_ERR(priv->mm);
 209
 210		seq_release_private(inode, file);
 211		return err;
 212	}
 213
 214	return 0;
 215}
 216
 217static int proc_map_release(struct inode *inode, struct file *file)
 218{
 219	struct seq_file *seq = file->private_data;
 220	struct proc_maps_private *priv = seq->private;
 221
 222	if (priv->mm)
 223		mmdrop(priv->mm);
 224
 225	return seq_release_private(inode, file);
 226}
 227
 228static int do_maps_open(struct inode *inode, struct file *file,
 229			const struct seq_operations *ops)
 230{
 231	return proc_maps_open(inode, file, ops,
 232				sizeof(struct proc_maps_private));
 233}
 234
 235/*
 236 * Indicate if the VMA is a stack for the given task; for
 237 * /proc/PID/maps that is the stack of the main task.
 238 */
 239static int is_stack(struct vm_area_struct *vma)
 240{
 241	/*
 242	 * We make no effort to guess what a given thread considers to be
 243	 * its "stack".  It's not even well-defined for programs written
 244	 * languages like Go.
 245	 */
 246	return vma->vm_start <= vma->vm_mm->start_stack &&
 247		vma->vm_end >= vma->vm_mm->start_stack;
 248}
 249
 250static void show_vma_header_prefix(struct seq_file *m,
 251				   unsigned long start, unsigned long end,
 252				   vm_flags_t flags, unsigned long long pgoff,
 253				   dev_t dev, unsigned long ino)
 254{
 255	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 256	seq_put_hex_ll(m, NULL, start, 8);
 257	seq_put_hex_ll(m, "-", end, 8);
 258	seq_putc(m, ' ');
 259	seq_putc(m, flags & VM_READ ? 'r' : '-');
 260	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
 261	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
 262	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
 263	seq_put_hex_ll(m, " ", pgoff, 8);
 264	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
 265	seq_put_hex_ll(m, ":", MINOR(dev), 2);
 266	seq_put_decimal_ull(m, " ", ino);
 267	seq_putc(m, ' ');
 268}
 269
 270static void
 271show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 272{
 273	struct mm_struct *mm = vma->vm_mm;
 274	struct file *file = vma->vm_file;
 275	vm_flags_t flags = vma->vm_flags;
 276	unsigned long ino = 0;
 277	unsigned long long pgoff = 0;
 278	unsigned long start, end;
 279	dev_t dev = 0;
 280	const char *name = NULL;
 281
 282	if (file) {
 283		struct inode *inode = file_inode(vma->vm_file);
 284		dev = inode->i_sb->s_dev;
 285		ino = inode->i_ino;
 286		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 287	}
 288
 289	start = vma->vm_start;
 290	end = vma->vm_end;
 291	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
 292
 293	/*
 294	 * Print the dentry name for named mappings, and a
 295	 * special [heap] marker for the heap:
 296	 */
 297	if (file) {
 298		seq_pad(m, ' ');
 299		seq_file_path(m, file, "\n");
 300		goto done;
 301	}
 302
 303	if (vma->vm_ops && vma->vm_ops->name) {
 304		name = vma->vm_ops->name(vma);
 305		if (name)
 306			goto done;
 307	}
 308
 309	name = arch_vma_name(vma);
 310	if (!name) {
 311		if (!mm) {
 312			name = "[vdso]";
 313			goto done;
 314		}
 315
 316		if (vma->vm_start <= mm->brk &&
 317		    vma->vm_end >= mm->start_brk) {
 318			name = "[heap]";
 319			goto done;
 320		}
 321
 322		if (is_stack(vma))
 323			name = "[stack]";
 324	}
 325
 326done:
 327	if (name) {
 328		seq_pad(m, ' ');
 329		seq_puts(m, name);
 330	}
 331	seq_putc(m, '\n');
 332}
 333
 334static int show_map(struct seq_file *m, void *v)
 335{
 336	show_map_vma(m, v);
 
 337	return 0;
 338}
 339
 340static const struct seq_operations proc_pid_maps_op = {
 341	.start	= m_start,
 342	.next	= m_next,
 343	.stop	= m_stop,
 344	.show	= show_map
 345};
 346
 347static int pid_maps_open(struct inode *inode, struct file *file)
 348{
 349	return do_maps_open(inode, file, &proc_pid_maps_op);
 350}
 351
 352const struct file_operations proc_pid_maps_operations = {
 353	.open		= pid_maps_open,
 354	.read		= seq_read,
 355	.llseek		= seq_lseek,
 356	.release	= proc_map_release,
 357};
 358
 359/*
 360 * Proportional Set Size(PSS): my share of RSS.
 361 *
 362 * PSS of a process is the count of pages it has in memory, where each
 363 * page is divided by the number of processes sharing it.  So if a
 364 * process has 1000 pages all to itself, and 1000 shared with one other
 365 * process, its PSS will be 1500.
 366 *
 367 * To keep (accumulated) division errors low, we adopt a 64bit
 368 * fixed-point pss counter to minimize division errors. So (pss >>
 369 * PSS_SHIFT) would be the real byte count.
 370 *
 371 * A shift of 12 before division means (assuming 4K page size):
 372 * 	- 1M 3-user-pages add up to 8KB errors;
 373 * 	- supports mapcount up to 2^24, or 16M;
 374 * 	- supports PSS up to 2^52 bytes, or 4PB.
 375 */
 376#define PSS_SHIFT 12
 377
 378#ifdef CONFIG_PROC_PAGE_MONITOR
 379struct mem_size_stats {
 380	unsigned long resident;
 381	unsigned long shared_clean;
 382	unsigned long shared_dirty;
 383	unsigned long private_clean;
 384	unsigned long private_dirty;
 385	unsigned long referenced;
 386	unsigned long anonymous;
 387	unsigned long lazyfree;
 388	unsigned long anonymous_thp;
 389	unsigned long shmem_thp;
 390	unsigned long file_thp;
 391	unsigned long swap;
 392	unsigned long shared_hugetlb;
 393	unsigned long private_hugetlb;
 394	u64 pss;
 395	u64 pss_anon;
 396	u64 pss_file;
 397	u64 pss_shmem;
 398	u64 pss_locked;
 399	u64 swap_pss;
 400	bool check_shmem_swap;
 401};
 402
 403static void smaps_page_accumulate(struct mem_size_stats *mss,
 404		struct page *page, unsigned long size, unsigned long pss,
 405		bool dirty, bool locked, bool private)
 406{
 407	mss->pss += pss;
 408
 409	if (PageAnon(page))
 410		mss->pss_anon += pss;
 411	else if (PageSwapBacked(page))
 412		mss->pss_shmem += pss;
 413	else
 414		mss->pss_file += pss;
 415
 416	if (locked)
 417		mss->pss_locked += pss;
 418
 419	if (dirty || PageDirty(page)) {
 420		if (private)
 421			mss->private_dirty += size;
 422		else
 423			mss->shared_dirty += size;
 424	} else {
 425		if (private)
 426			mss->private_clean += size;
 427		else
 428			mss->shared_clean += size;
 429	}
 430}
 431
 432static void smaps_account(struct mem_size_stats *mss, struct page *page,
 433		bool compound, bool young, bool dirty, bool locked)
 434{
 435	int i, nr = compound ? compound_nr(page) : 1;
 436	unsigned long size = nr * PAGE_SIZE;
 437
 438	/*
 439	 * First accumulate quantities that depend only on |size| and the type
 440	 * of the compound page.
 441	 */
 442	if (PageAnon(page)) {
 443		mss->anonymous += size;
 444		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
 445			mss->lazyfree += size;
 446	}
 447
 448	mss->resident += size;
 449	/* Accumulate the size in pages that have been accessed. */
 450	if (young || page_is_young(page) || PageReferenced(page))
 451		mss->referenced += size;
 452
 453	/*
 454	 * Then accumulate quantities that may depend on sharing, or that may
 455	 * differ page-by-page.
 456	 *
 457	 * page_count(page) == 1 guarantees the page is mapped exactly once.
 458	 * If any subpage of the compound page mapped with PTE it would elevate
 459	 * page_count().
 460	 */
 461	if (page_count(page) == 1) {
 462		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
 463			locked, true);
 464		return;
 465	}
 466	for (i = 0; i < nr; i++, page++) {
 467		int mapcount = page_mapcount(page);
 468		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
 469		if (mapcount >= 2)
 470			pss /= mapcount;
 471		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
 472				      mapcount < 2);
 473	}
 474}
 475
 476#ifdef CONFIG_SHMEM
 477static int smaps_pte_hole(unsigned long addr, unsigned long end,
 478			  __always_unused int depth, struct mm_walk *walk)
 479{
 480	struct mem_size_stats *mss = walk->private;
 481
 482	mss->swap += shmem_partial_swap_usage(
 483			walk->vma->vm_file->f_mapping, addr, end);
 484
 485	return 0;
 486}
 487#else
 488#define smaps_pte_hole		NULL
 489#endif /* CONFIG_SHMEM */
 490
 491static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 492		struct mm_walk *walk)
 493{
 494	struct mem_size_stats *mss = walk->private;
 495	struct vm_area_struct *vma = walk->vma;
 496	bool locked = !!(vma->vm_flags & VM_LOCKED);
 497	struct page *page = NULL;
 498
 499	if (pte_present(*pte)) {
 500		page = vm_normal_page(vma, addr, *pte);
 501	} else if (is_swap_pte(*pte)) {
 502		swp_entry_t swpent = pte_to_swp_entry(*pte);
 503
 504		if (!non_swap_entry(swpent)) {
 505			int mapcount;
 506
 507			mss->swap += PAGE_SIZE;
 508			mapcount = swp_swapcount(swpent);
 509			if (mapcount >= 2) {
 510				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
 511
 512				do_div(pss_delta, mapcount);
 513				mss->swap_pss += pss_delta;
 514			} else {
 515				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
 516			}
 517		} else if (is_migration_entry(swpent))
 518			page = migration_entry_to_page(swpent);
 519		else if (is_device_private_entry(swpent))
 520			page = device_private_entry_to_page(swpent);
 521	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
 522							&& pte_none(*pte))) {
 523		page = find_get_entry(vma->vm_file->f_mapping,
 524						linear_page_index(vma, addr));
 525		if (!page)
 526			return;
 527
 528		if (xa_is_value(page))
 529			mss->swap += PAGE_SIZE;
 530		else
 531			put_page(page);
 532
 533		return;
 534	}
 535
 536	if (!page)
 537		return;
 538
 539	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
 540}
 541
 542#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 543static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 544		struct mm_walk *walk)
 545{
 546	struct mem_size_stats *mss = walk->private;
 547	struct vm_area_struct *vma = walk->vma;
 548	bool locked = !!(vma->vm_flags & VM_LOCKED);
 549	struct page *page = NULL;
 550
 551	if (pmd_present(*pmd)) {
 552		/* FOLL_DUMP will return -EFAULT on huge zero page */
 553		page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
 554	} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
 555		swp_entry_t entry = pmd_to_swp_entry(*pmd);
 556
 557		if (is_migration_entry(entry))
 558			page = migration_entry_to_page(entry);
 559	}
 560	if (IS_ERR_OR_NULL(page))
 561		return;
 562	if (PageAnon(page))
 563		mss->anonymous_thp += HPAGE_PMD_SIZE;
 564	else if (PageSwapBacked(page))
 565		mss->shmem_thp += HPAGE_PMD_SIZE;
 566	else if (is_zone_device_page(page))
 567		/* pass */;
 568	else
 569		mss->file_thp += HPAGE_PMD_SIZE;
 570	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
 571}
 572#else
 573static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 574		struct mm_walk *walk)
 575{
 576}
 577#endif
 578
 579static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 580			   struct mm_walk *walk)
 581{
 582	struct vm_area_struct *vma = walk->vma;
 583	pte_t *pte;
 584	spinlock_t *ptl;
 585
 586	ptl = pmd_trans_huge_lock(pmd, vma);
 587	if (ptl) {
 588		smaps_pmd_entry(pmd, addr, walk);
 
 589		spin_unlock(ptl);
 590		goto out;
 591	}
 592
 593	if (pmd_trans_unstable(pmd))
 594		goto out;
 595	/*
 596	 * The mmap_lock held all the way back in m_start() is what
 597	 * keeps khugepaged out of here and from collapsing things
 598	 * in here.
 599	 */
 600	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 601	for (; addr != end; pte++, addr += PAGE_SIZE)
 602		smaps_pte_entry(pte, addr, walk);
 603	pte_unmap_unlock(pte - 1, ptl);
 604out:
 605	cond_resched();
 606	return 0;
 607}
 608
 609static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 610{
 611	/*
 612	 * Don't forget to update Documentation/ on changes.
 613	 */
 614	static const char mnemonics[BITS_PER_LONG][2] = {
 615		/*
 616		 * In case if we meet a flag we don't know about.
 617		 */
 618		[0 ... (BITS_PER_LONG-1)] = "??",
 619
 620		[ilog2(VM_READ)]	= "rd",
 621		[ilog2(VM_WRITE)]	= "wr",
 622		[ilog2(VM_EXEC)]	= "ex",
 623		[ilog2(VM_SHARED)]	= "sh",
 624		[ilog2(VM_MAYREAD)]	= "mr",
 625		[ilog2(VM_MAYWRITE)]	= "mw",
 626		[ilog2(VM_MAYEXEC)]	= "me",
 627		[ilog2(VM_MAYSHARE)]	= "ms",
 628		[ilog2(VM_GROWSDOWN)]	= "gd",
 629		[ilog2(VM_PFNMAP)]	= "pf",
 630		[ilog2(VM_DENYWRITE)]	= "dw",
 
 
 
 631		[ilog2(VM_LOCKED)]	= "lo",
 632		[ilog2(VM_IO)]		= "io",
 633		[ilog2(VM_SEQ_READ)]	= "sr",
 634		[ilog2(VM_RAND_READ)]	= "rr",
 635		[ilog2(VM_DONTCOPY)]	= "dc",
 636		[ilog2(VM_DONTEXPAND)]	= "de",
 637		[ilog2(VM_ACCOUNT)]	= "ac",
 638		[ilog2(VM_NORESERVE)]	= "nr",
 639		[ilog2(VM_HUGETLB)]	= "ht",
 640		[ilog2(VM_SYNC)]	= "sf",
 641		[ilog2(VM_ARCH_1)]	= "ar",
 642		[ilog2(VM_WIPEONFORK)]	= "wf",
 643		[ilog2(VM_DONTDUMP)]	= "dd",
 644#ifdef CONFIG_ARM64_BTI
 645		[ilog2(VM_ARM64_BTI)]	= "bt",
 646#endif
 647#ifdef CONFIG_MEM_SOFT_DIRTY
 648		[ilog2(VM_SOFTDIRTY)]	= "sd",
 649#endif
 650		[ilog2(VM_MIXEDMAP)]	= "mm",
 651		[ilog2(VM_HUGEPAGE)]	= "hg",
 652		[ilog2(VM_NOHUGEPAGE)]	= "nh",
 653		[ilog2(VM_MERGEABLE)]	= "mg",
 654		[ilog2(VM_UFFD_MISSING)]= "um",
 655		[ilog2(VM_UFFD_WP)]	= "uw",
 656#ifdef CONFIG_ARCH_HAS_PKEYS
 657		/* These come out via ProtectionKey: */
 658		[ilog2(VM_PKEY_BIT0)]	= "",
 659		[ilog2(VM_PKEY_BIT1)]	= "",
 660		[ilog2(VM_PKEY_BIT2)]	= "",
 661		[ilog2(VM_PKEY_BIT3)]	= "",
 662#if VM_PKEY_BIT4
 663		[ilog2(VM_PKEY_BIT4)]	= "",
 664#endif
 665#endif /* CONFIG_ARCH_HAS_PKEYS */
 666	};
 667	size_t i;
 668
 669	seq_puts(m, "VmFlags: ");
 670	for (i = 0; i < BITS_PER_LONG; i++) {
 671		if (!mnemonics[i][0])
 672			continue;
 673		if (vma->vm_flags & (1UL << i)) {
 674			seq_putc(m, mnemonics[i][0]);
 675			seq_putc(m, mnemonics[i][1]);
 676			seq_putc(m, ' ');
 677		}
 678	}
 679	seq_putc(m, '\n');
 680}
 681
 682#ifdef CONFIG_HUGETLB_PAGE
 683static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 684				 unsigned long addr, unsigned long end,
 685				 struct mm_walk *walk)
 686{
 687	struct mem_size_stats *mss = walk->private;
 688	struct vm_area_struct *vma = walk->vma;
 689	struct page *page = NULL;
 690
 691	if (pte_present(*pte)) {
 692		page = vm_normal_page(vma, addr, *pte);
 693	} else if (is_swap_pte(*pte)) {
 694		swp_entry_t swpent = pte_to_swp_entry(*pte);
 695
 696		if (is_migration_entry(swpent))
 697			page = migration_entry_to_page(swpent);
 698		else if (is_device_private_entry(swpent))
 699			page = device_private_entry_to_page(swpent);
 700	}
 701	if (page) {
 702		int mapcount = page_mapcount(page);
 703
 704		if (mapcount >= 2)
 705			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
 706		else
 707			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
 708	}
 709	return 0;
 710}
 711#else
 712#define smaps_hugetlb_range	NULL
 713#endif /* HUGETLB_PAGE */
 714
 715static const struct mm_walk_ops smaps_walk_ops = {
 716	.pmd_entry		= smaps_pte_range,
 717	.hugetlb_entry		= smaps_hugetlb_range,
 718};
 719
 720static const struct mm_walk_ops smaps_shmem_walk_ops = {
 721	.pmd_entry		= smaps_pte_range,
 722	.hugetlb_entry		= smaps_hugetlb_range,
 723	.pte_hole		= smaps_pte_hole,
 724};
 725
 726static void smap_gather_stats(struct vm_area_struct *vma,
 727			     struct mem_size_stats *mss)
 728{
 729#ifdef CONFIG_SHMEM
 730	/* In case of smaps_rollup, reset the value from previous vma */
 731	mss->check_shmem_swap = false;
 732	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
 733		/*
 734		 * For shared or readonly shmem mappings we know that all
 735		 * swapped out pages belong to the shmem object, and we can
 736		 * obtain the swap value much more efficiently. For private
 737		 * writable mappings, we might have COW pages that are
 738		 * not affected by the parent swapped out pages of the shmem
 739		 * object, so we have to distinguish them during the page walk.
 740		 * Unless we know that the shmem object (or the part mapped by
 741		 * our VMA) has no swapped out pages at all.
 742		 */
 743		unsigned long shmem_swapped = shmem_swap_usage(vma);
 744
 745		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
 746					!(vma->vm_flags & VM_WRITE)) {
 747			mss->swap += shmem_swapped;
 748		} else {
 749			mss->check_shmem_swap = true;
 750			walk_page_vma(vma, &smaps_shmem_walk_ops, mss);
 751			return;
 752		}
 753	}
 754#endif
 755	/* mmap_lock is held in m_start */
 756	walk_page_vma(vma, &smaps_walk_ops, mss);
 757}
 758
 759#define SEQ_PUT_DEC(str, val) \
 760		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
 761
 762/* Show the contents common for smaps and smaps_rollup */
 763static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
 764	bool rollup_mode)
 765{
 766	SEQ_PUT_DEC("Rss:            ", mss->resident);
 767	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
 768	if (rollup_mode) {
 769		/*
 770		 * These are meaningful only for smaps_rollup, otherwise two of
 771		 * them are zero, and the other one is the same as Pss.
 772		 */
 773		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
 774			mss->pss_anon >> PSS_SHIFT);
 775		SEQ_PUT_DEC(" kB\nPss_File:       ",
 776			mss->pss_file >> PSS_SHIFT);
 777		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
 778			mss->pss_shmem >> PSS_SHIFT);
 779	}
 780	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
 781	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
 782	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
 783	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
 784	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
 785	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
 786	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
 787	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
 788	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
 789	SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
 790	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
 791	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
 792				  mss->private_hugetlb >> 10, 7);
 793	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
 794	SEQ_PUT_DEC(" kB\nSwapPss:        ",
 795					mss->swap_pss >> PSS_SHIFT);
 796	SEQ_PUT_DEC(" kB\nLocked:         ",
 797					mss->pss_locked >> PSS_SHIFT);
 798	seq_puts(m, " kB\n");
 799}
 800
 801static int show_smap(struct seq_file *m, void *v)
 802{
 803	struct vm_area_struct *vma = v;
 804	struct mem_size_stats mss;
 805
 806	memset(&mss, 0, sizeof(mss));
 807
 808	smap_gather_stats(vma, &mss);
 809
 810	show_map_vma(m, vma);
 811
 812	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
 813	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
 814	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
 815	seq_puts(m, " kB\n");
 816
 817	__show_smap(m, &mss, false);
 818
 819	seq_printf(m, "THPeligible:    %d\n",
 820		   transparent_hugepage_enabled(vma));
 821
 822	if (arch_pkeys_enabled())
 823		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
 824	show_smap_vma_flags(m, vma);
 825
 
 
 826	return 0;
 827}
 828
 829static int show_smaps_rollup(struct seq_file *m, void *v)
 830{
 831	struct proc_maps_private *priv = m->private;
 832	struct mem_size_stats mss;
 833	struct mm_struct *mm;
 834	struct vm_area_struct *vma;
 835	unsigned long last_vma_end = 0;
 836	int ret = 0;
 837
 838	priv->task = get_proc_task(priv->inode);
 839	if (!priv->task)
 840		return -ESRCH;
 841
 842	mm = priv->mm;
 843	if (!mm || !mmget_not_zero(mm)) {
 844		ret = -ESRCH;
 845		goto out_put_task;
 846	}
 847
 848	memset(&mss, 0, sizeof(mss));
 849
 850	ret = mmap_read_lock_killable(mm);
 851	if (ret)
 852		goto out_put_mm;
 853
 854	hold_task_mempolicy(priv);
 855
 856	for (vma = priv->mm->mmap; vma; vma = vma->vm_next) {
 857		smap_gather_stats(vma, &mss);
 858		last_vma_end = vma->vm_end;
 859	}
 860
 861	show_vma_header_prefix(m, priv->mm->mmap->vm_start,
 862			       last_vma_end, 0, 0, 0, 0);
 863	seq_pad(m, ' ');
 864	seq_puts(m, "[rollup]\n");
 865
 866	__show_smap(m, &mss, true);
 867
 868	release_task_mempolicy(priv);
 869	mmap_read_unlock(mm);
 870
 871out_put_mm:
 872	mmput(mm);
 873out_put_task:
 874	put_task_struct(priv->task);
 875	priv->task = NULL;
 876
 877	return ret;
 878}
 879#undef SEQ_PUT_DEC
 880
 881static const struct seq_operations proc_pid_smaps_op = {
 882	.start	= m_start,
 883	.next	= m_next,
 884	.stop	= m_stop,
 885	.show	= show_smap
 886};
 887
 888static int pid_smaps_open(struct inode *inode, struct file *file)
 889{
 890	return do_maps_open(inode, file, &proc_pid_smaps_op);
 891}
 892
 893static int smaps_rollup_open(struct inode *inode, struct file *file)
 894{
 895	int ret;
 896	struct proc_maps_private *priv;
 897
 898	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
 899	if (!priv)
 900		return -ENOMEM;
 901
 902	ret = single_open(file, show_smaps_rollup, priv);
 903	if (ret)
 904		goto out_free;
 905
 906	priv->inode = inode;
 907	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 908	if (IS_ERR(priv->mm)) {
 909		ret = PTR_ERR(priv->mm);
 910
 911		single_release(inode, file);
 912		goto out_free;
 913	}
 914
 915	return 0;
 916
 917out_free:
 918	kfree(priv);
 919	return ret;
 920}
 921
 922static int smaps_rollup_release(struct inode *inode, struct file *file)
 923{
 924	struct seq_file *seq = file->private_data;
 925	struct proc_maps_private *priv = seq->private;
 926
 927	if (priv->mm)
 928		mmdrop(priv->mm);
 929
 930	kfree(priv);
 931	return single_release(inode, file);
 932}
 933
 934const struct file_operations proc_pid_smaps_operations = {
 935	.open		= pid_smaps_open,
 936	.read		= seq_read,
 937	.llseek		= seq_lseek,
 938	.release	= proc_map_release,
 939};
 940
 941const struct file_operations proc_pid_smaps_rollup_operations = {
 942	.open		= smaps_rollup_open,
 943	.read		= seq_read,
 944	.llseek		= seq_lseek,
 945	.release	= smaps_rollup_release,
 946};
 947
 948enum clear_refs_types {
 949	CLEAR_REFS_ALL = 1,
 950	CLEAR_REFS_ANON,
 951	CLEAR_REFS_MAPPED,
 952	CLEAR_REFS_SOFT_DIRTY,
 953	CLEAR_REFS_MM_HIWATER_RSS,
 954	CLEAR_REFS_LAST,
 955};
 956
 957struct clear_refs_private {
 958	enum clear_refs_types type;
 959};
 960
 961#ifdef CONFIG_MEM_SOFT_DIRTY
 962static inline void clear_soft_dirty(struct vm_area_struct *vma,
 963		unsigned long addr, pte_t *pte)
 964{
 965	/*
 966	 * The soft-dirty tracker uses #PF-s to catch writes
 967	 * to pages, so write-protect the pte as well. See the
 968	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
 969	 * of how soft-dirty works.
 970	 */
 971	pte_t ptent = *pte;
 972
 973	if (pte_present(ptent)) {
 974		pte_t old_pte;
 975
 976		old_pte = ptep_modify_prot_start(vma, addr, pte);
 977		ptent = pte_wrprotect(old_pte);
 978		ptent = pte_clear_soft_dirty(ptent);
 979		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
 980	} else if (is_swap_pte(ptent)) {
 981		ptent = pte_swp_clear_soft_dirty(ptent);
 982		set_pte_at(vma->vm_mm, addr, pte, ptent);
 983	}
 984}
 985#else
 986static inline void clear_soft_dirty(struct vm_area_struct *vma,
 987		unsigned long addr, pte_t *pte)
 988{
 989}
 990#endif
 991
 992#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 993static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 994		unsigned long addr, pmd_t *pmdp)
 995{
 996	pmd_t old, pmd = *pmdp;
 997
 998	if (pmd_present(pmd)) {
 999		/* See comment in change_huge_pmd() */
1000		old = pmdp_invalidate(vma, addr, pmdp);
1001		if (pmd_dirty(old))
1002			pmd = pmd_mkdirty(pmd);
1003		if (pmd_young(old))
1004			pmd = pmd_mkyoung(pmd);
1005
1006		pmd = pmd_wrprotect(pmd);
1007		pmd = pmd_clear_soft_dirty(pmd);
1008
1009		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1010	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1011		pmd = pmd_swp_clear_soft_dirty(pmd);
1012		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1013	}
1014}
1015#else
1016static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1017		unsigned long addr, pmd_t *pmdp)
1018{
1019}
1020#endif
1021
1022static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1023				unsigned long end, struct mm_walk *walk)
1024{
1025	struct clear_refs_private *cp = walk->private;
1026	struct vm_area_struct *vma = walk->vma;
1027	pte_t *pte, ptent;
1028	spinlock_t *ptl;
1029	struct page *page;
1030
1031	ptl = pmd_trans_huge_lock(pmd, vma);
1032	if (ptl) {
1033		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1034			clear_soft_dirty_pmd(vma, addr, pmd);
1035			goto out;
1036		}
1037
1038		if (!pmd_present(*pmd))
1039			goto out;
1040
1041		page = pmd_page(*pmd);
1042
1043		/* Clear accessed and referenced bits. */
1044		pmdp_test_and_clear_young(vma, addr, pmd);
1045		test_and_clear_page_young(page);
1046		ClearPageReferenced(page);
1047out:
1048		spin_unlock(ptl);
1049		return 0;
1050	}
1051
1052	if (pmd_trans_unstable(pmd))
1053		return 0;
1054
1055	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1056	for (; addr != end; pte++, addr += PAGE_SIZE) {
1057		ptent = *pte;
1058
1059		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1060			clear_soft_dirty(vma, addr, pte);
1061			continue;
1062		}
1063
1064		if (!pte_present(ptent))
1065			continue;
1066
1067		page = vm_normal_page(vma, addr, ptent);
1068		if (!page)
1069			continue;
1070
1071		/* Clear accessed and referenced bits. */
1072		ptep_test_and_clear_young(vma, addr, pte);
1073		test_and_clear_page_young(page);
1074		ClearPageReferenced(page);
1075	}
1076	pte_unmap_unlock(pte - 1, ptl);
1077	cond_resched();
1078	return 0;
1079}
1080
1081static int clear_refs_test_walk(unsigned long start, unsigned long end,
1082				struct mm_walk *walk)
1083{
1084	struct clear_refs_private *cp = walk->private;
1085	struct vm_area_struct *vma = walk->vma;
1086
1087	if (vma->vm_flags & VM_PFNMAP)
1088		return 1;
1089
1090	/*
1091	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1092	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1093	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1094	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1095	 */
1096	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1097		return 1;
1098	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1099		return 1;
1100	return 0;
1101}
1102
1103static const struct mm_walk_ops clear_refs_walk_ops = {
1104	.pmd_entry		= clear_refs_pte_range,
1105	.test_walk		= clear_refs_test_walk,
1106};
1107
1108static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1109				size_t count, loff_t *ppos)
1110{
1111	struct task_struct *task;
1112	char buffer[PROC_NUMBUF];
1113	struct mm_struct *mm;
1114	struct vm_area_struct *vma;
1115	enum clear_refs_types type;
1116	struct mmu_gather tlb;
1117	int itype;
1118	int rv;
1119
1120	memset(buffer, 0, sizeof(buffer));
1121	if (count > sizeof(buffer) - 1)
1122		count = sizeof(buffer) - 1;
1123	if (copy_from_user(buffer, buf, count))
1124		return -EFAULT;
1125	rv = kstrtoint(strstrip(buffer), 10, &itype);
1126	if (rv < 0)
1127		return rv;
1128	type = (enum clear_refs_types)itype;
1129	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1130		return -EINVAL;
1131
1132	task = get_proc_task(file_inode(file));
1133	if (!task)
1134		return -ESRCH;
1135	mm = get_task_mm(task);
1136	if (mm) {
1137		struct mmu_notifier_range range;
1138		struct clear_refs_private cp = {
1139			.type = type,
1140		};
1141
1142		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1143			if (mmap_write_lock_killable(mm)) {
1144				count = -EINTR;
1145				goto out_mm;
1146			}
1147
1148			/*
1149			 * Writing 5 to /proc/pid/clear_refs resets the peak
1150			 * resident set size to this mm's current rss value.
1151			 */
1152			reset_mm_hiwater_rss(mm);
1153			mmap_write_unlock(mm);
1154			goto out_mm;
1155		}
1156
1157		if (mmap_read_lock_killable(mm)) {
1158			count = -EINTR;
1159			goto out_mm;
1160		}
1161		tlb_gather_mmu(&tlb, mm, 0, -1);
1162		if (type == CLEAR_REFS_SOFT_DIRTY) {
1163			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1164				if (!(vma->vm_flags & VM_SOFTDIRTY))
1165					continue;
1166				mmap_read_unlock(mm);
1167				if (mmap_write_lock_killable(mm)) {
1168					count = -EINTR;
1169					goto out_mm;
1170				}
1171				/*
1172				 * Avoid to modify vma->vm_flags
1173				 * without locked ops while the
1174				 * coredump reads the vm_flags.
1175				 */
1176				if (!mmget_still_valid(mm)) {
1177					/*
1178					 * Silently return "count"
1179					 * like if get_task_mm()
1180					 * failed. FIXME: should this
1181					 * function have returned
1182					 * -ESRCH if get_task_mm()
1183					 * failed like if
1184					 * get_proc_task() fails?
1185					 */
1186					mmap_write_unlock(mm);
1187					goto out_mm;
1188				}
1189				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1190					vma->vm_flags &= ~VM_SOFTDIRTY;
1191					vma_set_page_prot(vma);
1192				}
1193				mmap_write_downgrade(mm);
1194				break;
1195			}
1196
1197			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1198						0, NULL, mm, 0, -1UL);
1199			mmu_notifier_invalidate_range_start(&range);
1200		}
1201		walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
1202				&cp);
1203		if (type == CLEAR_REFS_SOFT_DIRTY)
1204			mmu_notifier_invalidate_range_end(&range);
1205		tlb_finish_mmu(&tlb, 0, -1);
1206		mmap_read_unlock(mm);
1207out_mm:
1208		mmput(mm);
1209	}
1210	put_task_struct(task);
1211
1212	return count;
1213}
1214
1215const struct file_operations proc_clear_refs_operations = {
1216	.write		= clear_refs_write,
1217	.llseek		= noop_llseek,
1218};
1219
1220typedef struct {
1221	u64 pme;
1222} pagemap_entry_t;
1223
1224struct pagemapread {
1225	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1226	pagemap_entry_t *buffer;
1227	bool show_pfn;
1228};
1229
1230#define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1231#define PAGEMAP_WALK_MASK	(PMD_MASK)
1232
1233#define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1234#define PM_PFRAME_BITS		55
1235#define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1236#define PM_SOFT_DIRTY		BIT_ULL(55)
1237#define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1238#define PM_FILE			BIT_ULL(61)
1239#define PM_SWAP			BIT_ULL(62)
1240#define PM_PRESENT		BIT_ULL(63)
1241
1242#define PM_END_OF_BUFFER    1
1243
1244static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1245{
1246	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1247}
1248
1249static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1250			  struct pagemapread *pm)
1251{
1252	pm->buffer[pm->pos++] = *pme;
1253	if (pm->pos >= pm->len)
1254		return PM_END_OF_BUFFER;
1255	return 0;
1256}
1257
1258static int pagemap_pte_hole(unsigned long start, unsigned long end,
1259			    __always_unused int depth, struct mm_walk *walk)
1260{
1261	struct pagemapread *pm = walk->private;
1262	unsigned long addr = start;
1263	int err = 0;
1264
1265	while (addr < end) {
1266		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1267		pagemap_entry_t pme = make_pme(0, 0);
1268		/* End of address space hole, which we mark as non-present. */
1269		unsigned long hole_end;
1270
1271		if (vma)
1272			hole_end = min(end, vma->vm_start);
1273		else
1274			hole_end = end;
1275
1276		for (; addr < hole_end; addr += PAGE_SIZE) {
1277			err = add_to_pagemap(addr, &pme, pm);
1278			if (err)
1279				goto out;
1280		}
1281
1282		if (!vma)
1283			break;
1284
1285		/* Addresses in the VMA. */
1286		if (vma->vm_flags & VM_SOFTDIRTY)
1287			pme = make_pme(0, PM_SOFT_DIRTY);
1288		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1289			err = add_to_pagemap(addr, &pme, pm);
1290			if (err)
1291				goto out;
1292		}
1293	}
1294out:
1295	return err;
1296}
1297
1298static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1299		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1300{
1301	u64 frame = 0, flags = 0;
1302	struct page *page = NULL;
1303
1304	if (pte_present(pte)) {
1305		if (pm->show_pfn)
1306			frame = pte_pfn(pte);
1307		flags |= PM_PRESENT;
1308		page = vm_normal_page(vma, addr, pte);
1309		if (pte_soft_dirty(pte))
1310			flags |= PM_SOFT_DIRTY;
1311	} else if (is_swap_pte(pte)) {
1312		swp_entry_t entry;
1313		if (pte_swp_soft_dirty(pte))
1314			flags |= PM_SOFT_DIRTY;
1315		entry = pte_to_swp_entry(pte);
1316		if (pm->show_pfn)
1317			frame = swp_type(entry) |
1318				(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1319		flags |= PM_SWAP;
1320		if (is_migration_entry(entry))
1321			page = migration_entry_to_page(entry);
1322
1323		if (is_device_private_entry(entry))
1324			page = device_private_entry_to_page(entry);
1325	}
1326
1327	if (page && !PageAnon(page))
1328		flags |= PM_FILE;
1329	if (page && page_mapcount(page) == 1)
1330		flags |= PM_MMAP_EXCLUSIVE;
1331	if (vma->vm_flags & VM_SOFTDIRTY)
1332		flags |= PM_SOFT_DIRTY;
1333
1334	return make_pme(frame, flags);
1335}
1336
1337static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1338			     struct mm_walk *walk)
1339{
1340	struct vm_area_struct *vma = walk->vma;
1341	struct pagemapread *pm = walk->private;
1342	spinlock_t *ptl;
1343	pte_t *pte, *orig_pte;
1344	int err = 0;
1345
1346#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1347	ptl = pmd_trans_huge_lock(pmdp, vma);
1348	if (ptl) {
1349		u64 flags = 0, frame = 0;
1350		pmd_t pmd = *pmdp;
1351		struct page *page = NULL;
1352
1353		if (vma->vm_flags & VM_SOFTDIRTY)
1354			flags |= PM_SOFT_DIRTY;
1355
1356		if (pmd_present(pmd)) {
1357			page = pmd_page(pmd);
1358
1359			flags |= PM_PRESENT;
1360			if (pmd_soft_dirty(pmd))
1361				flags |= PM_SOFT_DIRTY;
1362			if (pm->show_pfn)
1363				frame = pmd_pfn(pmd) +
1364					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1365		}
1366#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1367		else if (is_swap_pmd(pmd)) {
1368			swp_entry_t entry = pmd_to_swp_entry(pmd);
1369			unsigned long offset;
1370
1371			if (pm->show_pfn) {
1372				offset = swp_offset(entry) +
1373					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1374				frame = swp_type(entry) |
1375					(offset << MAX_SWAPFILES_SHIFT);
1376			}
1377			flags |= PM_SWAP;
1378			if (pmd_swp_soft_dirty(pmd))
1379				flags |= PM_SOFT_DIRTY;
1380			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1381			page = migration_entry_to_page(entry);
1382		}
1383#endif
1384
1385		if (page && page_mapcount(page) == 1)
1386			flags |= PM_MMAP_EXCLUSIVE;
1387
1388		for (; addr != end; addr += PAGE_SIZE) {
1389			pagemap_entry_t pme = make_pme(frame, flags);
1390
1391			err = add_to_pagemap(addr, &pme, pm);
1392			if (err)
1393				break;
1394			if (pm->show_pfn) {
1395				if (flags & PM_PRESENT)
1396					frame++;
1397				else if (flags & PM_SWAP)
1398					frame += (1 << MAX_SWAPFILES_SHIFT);
1399			}
1400		}
1401		spin_unlock(ptl);
1402		return err;
1403	}
1404
1405	if (pmd_trans_unstable(pmdp))
1406		return 0;
1407#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1408
1409	/*
1410	 * We can assume that @vma always points to a valid one and @end never
1411	 * goes beyond vma->vm_end.
1412	 */
1413	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1414	for (; addr < end; pte++, addr += PAGE_SIZE) {
1415		pagemap_entry_t pme;
1416
1417		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1418		err = add_to_pagemap(addr, &pme, pm);
1419		if (err)
1420			break;
1421	}
1422	pte_unmap_unlock(orig_pte, ptl);
1423
1424	cond_resched();
1425
1426	return err;
1427}
1428
1429#ifdef CONFIG_HUGETLB_PAGE
1430/* This function walks within one hugetlb entry in the single call */
1431static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1432				 unsigned long addr, unsigned long end,
1433				 struct mm_walk *walk)
1434{
1435	struct pagemapread *pm = walk->private;
1436	struct vm_area_struct *vma = walk->vma;
1437	u64 flags = 0, frame = 0;
1438	int err = 0;
1439	pte_t pte;
1440
1441	if (vma->vm_flags & VM_SOFTDIRTY)
1442		flags |= PM_SOFT_DIRTY;
1443
1444	pte = huge_ptep_get(ptep);
1445	if (pte_present(pte)) {
1446		struct page *page = pte_page(pte);
1447
1448		if (!PageAnon(page))
1449			flags |= PM_FILE;
1450
1451		if (page_mapcount(page) == 1)
1452			flags |= PM_MMAP_EXCLUSIVE;
1453
1454		flags |= PM_PRESENT;
1455		if (pm->show_pfn)
1456			frame = pte_pfn(pte) +
1457				((addr & ~hmask) >> PAGE_SHIFT);
1458	}
1459
1460	for (; addr != end; addr += PAGE_SIZE) {
1461		pagemap_entry_t pme = make_pme(frame, flags);
1462
1463		err = add_to_pagemap(addr, &pme, pm);
1464		if (err)
1465			return err;
1466		if (pm->show_pfn && (flags & PM_PRESENT))
1467			frame++;
1468	}
1469
1470	cond_resched();
1471
1472	return err;
1473}
1474#else
1475#define pagemap_hugetlb_range	NULL
1476#endif /* HUGETLB_PAGE */
1477
1478static const struct mm_walk_ops pagemap_ops = {
1479	.pmd_entry	= pagemap_pmd_range,
1480	.pte_hole	= pagemap_pte_hole,
1481	.hugetlb_entry	= pagemap_hugetlb_range,
1482};
1483
1484/*
1485 * /proc/pid/pagemap - an array mapping virtual pages to pfns
1486 *
1487 * For each page in the address space, this file contains one 64-bit entry
1488 * consisting of the following:
1489 *
1490 * Bits 0-54  page frame number (PFN) if present
1491 * Bits 0-4   swap type if swapped
1492 * Bits 5-54  swap offset if swapped
1493 * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1494 * Bit  56    page exclusively mapped
1495 * Bits 57-60 zero
1496 * Bit  61    page is file-page or shared-anon
1497 * Bit  62    page swapped
1498 * Bit  63    page present
1499 *
1500 * If the page is not present but in swap, then the PFN contains an
1501 * encoding of the swap file number and the page's offset into the
1502 * swap. Unmapped pages return a null PFN. This allows determining
1503 * precisely which pages are mapped (or in swap) and comparing mapped
1504 * pages between processes.
1505 *
1506 * Efficient users of this interface will use /proc/pid/maps to
1507 * determine which areas of memory are actually mapped and llseek to
1508 * skip over unmapped regions.
1509 */
1510static ssize_t pagemap_read(struct file *file, char __user *buf,
1511			    size_t count, loff_t *ppos)
1512{
1513	struct mm_struct *mm = file->private_data;
1514	struct pagemapread pm;
1515	unsigned long src;
1516	unsigned long svpfn;
1517	unsigned long start_vaddr;
1518	unsigned long end_vaddr;
1519	int ret = 0, copied = 0;
1520
1521	if (!mm || !mmget_not_zero(mm))
1522		goto out;
1523
1524	ret = -EINVAL;
1525	/* file position must be aligned */
1526	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1527		goto out_mm;
1528
1529	ret = 0;
1530	if (!count)
1531		goto out_mm;
1532
1533	/* do not disclose physical addresses: attack vector */
1534	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1535
1536	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1537	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1538	ret = -ENOMEM;
1539	if (!pm.buffer)
1540		goto out_mm;
1541
1542	src = *ppos;
1543	svpfn = src / PM_ENTRY_BYTES;
1544	start_vaddr = svpfn << PAGE_SHIFT;
1545	end_vaddr = mm->task_size;
1546
1547	/* watch out for wraparound */
1548	if (svpfn > mm->task_size >> PAGE_SHIFT)
1549		start_vaddr = end_vaddr;
1550
1551	/*
1552	 * The odds are that this will stop walking way
1553	 * before end_vaddr, because the length of the
1554	 * user buffer is tracked in "pm", and the walk
1555	 * will stop when we hit the end of the buffer.
1556	 */
1557	ret = 0;
1558	while (count && (start_vaddr < end_vaddr)) {
1559		int len;
1560		unsigned long end;
1561
1562		pm.pos = 0;
1563		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1564		/* overflow ? */
1565		if (end < start_vaddr || end > end_vaddr)
1566			end = end_vaddr;
1567		ret = mmap_read_lock_killable(mm);
1568		if (ret)
1569			goto out_free;
1570		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1571		mmap_read_unlock(mm);
1572		start_vaddr = end;
1573
1574		len = min(count, PM_ENTRY_BYTES * pm.pos);
1575		if (copy_to_user(buf, pm.buffer, len)) {
1576			ret = -EFAULT;
1577			goto out_free;
1578		}
1579		copied += len;
1580		buf += len;
1581		count -= len;
1582	}
1583	*ppos += copied;
1584	if (!ret || ret == PM_END_OF_BUFFER)
1585		ret = copied;
1586
1587out_free:
1588	kfree(pm.buffer);
1589out_mm:
1590	mmput(mm);
1591out:
1592	return ret;
1593}
1594
1595static int pagemap_open(struct inode *inode, struct file *file)
1596{
1597	struct mm_struct *mm;
1598
1599	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1600	if (IS_ERR(mm))
1601		return PTR_ERR(mm);
1602	file->private_data = mm;
1603	return 0;
1604}
1605
1606static int pagemap_release(struct inode *inode, struct file *file)
1607{
1608	struct mm_struct *mm = file->private_data;
1609
1610	if (mm)
1611		mmdrop(mm);
1612	return 0;
1613}
1614
1615const struct file_operations proc_pagemap_operations = {
1616	.llseek		= mem_lseek, /* borrow this */
1617	.read		= pagemap_read,
1618	.open		= pagemap_open,
1619	.release	= pagemap_release,
1620};
1621#endif /* CONFIG_PROC_PAGE_MONITOR */
1622
1623#ifdef CONFIG_NUMA
1624
1625struct numa_maps {
1626	unsigned long pages;
1627	unsigned long anon;
1628	unsigned long active;
1629	unsigned long writeback;
1630	unsigned long mapcount_max;
1631	unsigned long dirty;
1632	unsigned long swapcache;
1633	unsigned long node[MAX_NUMNODES];
1634};
1635
1636struct numa_maps_private {
1637	struct proc_maps_private proc_maps;
1638	struct numa_maps md;
1639};
1640
1641static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1642			unsigned long nr_pages)
1643{
1644	int count = page_mapcount(page);
1645
1646	md->pages += nr_pages;
1647	if (pte_dirty || PageDirty(page))
1648		md->dirty += nr_pages;
1649
1650	if (PageSwapCache(page))
1651		md->swapcache += nr_pages;
1652
1653	if (PageActive(page) || PageUnevictable(page))
1654		md->active += nr_pages;
1655
1656	if (PageWriteback(page))
1657		md->writeback += nr_pages;
1658
1659	if (PageAnon(page))
1660		md->anon += nr_pages;
1661
1662	if (count > md->mapcount_max)
1663		md->mapcount_max = count;
1664
1665	md->node[page_to_nid(page)] += nr_pages;
1666}
1667
1668static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1669		unsigned long addr)
1670{
1671	struct page *page;
1672	int nid;
1673
1674	if (!pte_present(pte))
1675		return NULL;
1676
1677	page = vm_normal_page(vma, addr, pte);
1678	if (!page)
1679		return NULL;
1680
1681	if (PageReserved(page))
1682		return NULL;
1683
1684	nid = page_to_nid(page);
1685	if (!node_isset(nid, node_states[N_MEMORY]))
1686		return NULL;
1687
1688	return page;
1689}
1690
1691#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1692static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1693					      struct vm_area_struct *vma,
1694					      unsigned long addr)
1695{
1696	struct page *page;
1697	int nid;
1698
1699	if (!pmd_present(pmd))
1700		return NULL;
1701
1702	page = vm_normal_page_pmd(vma, addr, pmd);
1703	if (!page)
1704		return NULL;
1705
1706	if (PageReserved(page))
1707		return NULL;
1708
1709	nid = page_to_nid(page);
1710	if (!node_isset(nid, node_states[N_MEMORY]))
1711		return NULL;
1712
1713	return page;
1714}
1715#endif
1716
1717static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1718		unsigned long end, struct mm_walk *walk)
1719{
1720	struct numa_maps *md = walk->private;
1721	struct vm_area_struct *vma = walk->vma;
1722	spinlock_t *ptl;
1723	pte_t *orig_pte;
1724	pte_t *pte;
1725
1726#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1727	ptl = pmd_trans_huge_lock(pmd, vma);
1728	if (ptl) {
1729		struct page *page;
1730
1731		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1732		if (page)
1733			gather_stats(page, md, pmd_dirty(*pmd),
1734				     HPAGE_PMD_SIZE/PAGE_SIZE);
1735		spin_unlock(ptl);
1736		return 0;
1737	}
1738
1739	if (pmd_trans_unstable(pmd))
1740		return 0;
1741#endif
1742	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1743	do {
1744		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1745		if (!page)
1746			continue;
1747		gather_stats(page, md, pte_dirty(*pte), 1);
1748
1749	} while (pte++, addr += PAGE_SIZE, addr != end);
1750	pte_unmap_unlock(orig_pte, ptl);
1751	cond_resched();
1752	return 0;
1753}
1754#ifdef CONFIG_HUGETLB_PAGE
1755static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1756		unsigned long addr, unsigned long end, struct mm_walk *walk)
1757{
1758	pte_t huge_pte = huge_ptep_get(pte);
1759	struct numa_maps *md;
1760	struct page *page;
1761
1762	if (!pte_present(huge_pte))
1763		return 0;
1764
1765	page = pte_page(huge_pte);
1766	if (!page)
1767		return 0;
1768
1769	md = walk->private;
1770	gather_stats(page, md, pte_dirty(huge_pte), 1);
1771	return 0;
1772}
1773
1774#else
1775static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1776		unsigned long addr, unsigned long end, struct mm_walk *walk)
1777{
1778	return 0;
1779}
1780#endif
1781
1782static const struct mm_walk_ops show_numa_ops = {
1783	.hugetlb_entry = gather_hugetlb_stats,
1784	.pmd_entry = gather_pte_stats,
1785};
1786
1787/*
1788 * Display pages allocated per node and memory policy via /proc.
1789 */
1790static int show_numa_map(struct seq_file *m, void *v)
1791{
1792	struct numa_maps_private *numa_priv = m->private;
1793	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1794	struct vm_area_struct *vma = v;
1795	struct numa_maps *md = &numa_priv->md;
1796	struct file *file = vma->vm_file;
1797	struct mm_struct *mm = vma->vm_mm;
1798	struct mempolicy *pol;
1799	char buffer[64];
1800	int nid;
1801
1802	if (!mm)
1803		return 0;
1804
1805	/* Ensure we start with an empty set of numa_maps statistics. */
1806	memset(md, 0, sizeof(*md));
1807
1808	pol = __get_vma_policy(vma, vma->vm_start);
1809	if (pol) {
1810		mpol_to_str(buffer, sizeof(buffer), pol);
1811		mpol_cond_put(pol);
1812	} else {
1813		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1814	}
1815
1816	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1817
1818	if (file) {
1819		seq_puts(m, " file=");
1820		seq_file_path(m, file, "\n\t= ");
1821	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1822		seq_puts(m, " heap");
1823	} else if (is_stack(vma)) {
1824		seq_puts(m, " stack");
1825	}
1826
1827	if (is_vm_hugetlb_page(vma))
1828		seq_puts(m, " huge");
1829
1830	/* mmap_lock is held by m_start */
1831	walk_page_vma(vma, &show_numa_ops, md);
1832
1833	if (!md->pages)
1834		goto out;
1835
1836	if (md->anon)
1837		seq_printf(m, " anon=%lu", md->anon);
1838
1839	if (md->dirty)
1840		seq_printf(m, " dirty=%lu", md->dirty);
1841
1842	if (md->pages != md->anon && md->pages != md->dirty)
1843		seq_printf(m, " mapped=%lu", md->pages);
1844
1845	if (md->mapcount_max > 1)
1846		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1847
1848	if (md->swapcache)
1849		seq_printf(m, " swapcache=%lu", md->swapcache);
1850
1851	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1852		seq_printf(m, " active=%lu", md->active);
1853
1854	if (md->writeback)
1855		seq_printf(m, " writeback=%lu", md->writeback);
1856
1857	for_each_node_state(nid, N_MEMORY)
1858		if (md->node[nid])
1859			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1860
1861	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1862out:
1863	seq_putc(m, '\n');
 
1864	return 0;
1865}
1866
1867static const struct seq_operations proc_pid_numa_maps_op = {
1868	.start  = m_start,
1869	.next   = m_next,
1870	.stop   = m_stop,
1871	.show   = show_numa_map,
1872};
1873
1874static int pid_numa_maps_open(struct inode *inode, struct file *file)
1875{
1876	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1877				sizeof(struct numa_maps_private));
1878}
1879
1880const struct file_operations proc_pid_numa_maps_operations = {
1881	.open		= pid_numa_maps_open,
1882	.read		= seq_read,
1883	.llseek		= seq_lseek,
1884	.release	= proc_map_release,
1885};
1886
1887#endif /* CONFIG_NUMA */