xref: /linux/fs/proc/task_mmu.c (revision a4cc96d1f0170b779c32c6b2cc58764f5d2cdef0)
1 #include <linux/mm.h>
2 #include <linux/vmacache.h>
3 #include <linux/hugetlb.h>
4 #include <linux/huge_mm.h>
5 #include <linux/mount.h>
6 #include <linux/seq_file.h>
7 #include <linux/highmem.h>
8 #include <linux/ptrace.h>
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
11 #include <linux/mempolicy.h>
12 #include <linux/rmap.h>
13 #include <linux/swap.h>
14 #include <linux/swapops.h>
15 #include <linux/mmu_notifier.h>
16 #include <linux/page_idle.h>
17 #include <linux/shmem_fs.h>
18 
19 #include <asm/elf.h>
20 #include <asm/uaccess.h>
21 #include <asm/tlbflush.h>
22 #include "internal.h"
23 
24 void task_mem(struct seq_file *m, struct mm_struct *mm)
25 {
26 	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
27 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
28 
29 	anon = get_mm_counter(mm, MM_ANONPAGES);
30 	file = get_mm_counter(mm, MM_FILEPAGES);
31 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
32 
33 	/*
34 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
35 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
36 	 * collector of these hiwater stats must therefore get total_vm
37 	 * and rss too, which will usually be the higher.  Barriers? not
38 	 * worth the effort, such snapshots can always be inconsistent.
39 	 */
40 	hiwater_vm = total_vm = mm->total_vm;
41 	if (hiwater_vm < mm->hiwater_vm)
42 		hiwater_vm = mm->hiwater_vm;
43 	hiwater_rss = total_rss = anon + file + shmem;
44 	if (hiwater_rss < mm->hiwater_rss)
45 		hiwater_rss = mm->hiwater_rss;
46 
47 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
48 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
49 	swap = get_mm_counter(mm, MM_SWAPENTS);
50 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
51 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
52 	seq_printf(m,
53 		"VmPeak:\t%8lu kB\n"
54 		"VmSize:\t%8lu kB\n"
55 		"VmLck:\t%8lu kB\n"
56 		"VmPin:\t%8lu kB\n"
57 		"VmHWM:\t%8lu kB\n"
58 		"VmRSS:\t%8lu kB\n"
59 		"RssAnon:\t%8lu kB\n"
60 		"RssFile:\t%8lu kB\n"
61 		"RssShmem:\t%8lu kB\n"
62 		"VmData:\t%8lu kB\n"
63 		"VmStk:\t%8lu kB\n"
64 		"VmExe:\t%8lu kB\n"
65 		"VmLib:\t%8lu kB\n"
66 		"VmPTE:\t%8lu kB\n"
67 		"VmPMD:\t%8lu kB\n"
68 		"VmSwap:\t%8lu kB\n",
69 		hiwater_vm << (PAGE_SHIFT-10),
70 		total_vm << (PAGE_SHIFT-10),
71 		mm->locked_vm << (PAGE_SHIFT-10),
72 		mm->pinned_vm << (PAGE_SHIFT-10),
73 		hiwater_rss << (PAGE_SHIFT-10),
74 		total_rss << (PAGE_SHIFT-10),
75 		anon << (PAGE_SHIFT-10),
76 		file << (PAGE_SHIFT-10),
77 		shmem << (PAGE_SHIFT-10),
78 		mm->data_vm << (PAGE_SHIFT-10),
79 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
80 		ptes >> 10,
81 		pmds >> 10,
82 		swap << (PAGE_SHIFT-10));
83 	hugetlb_report_usage(m, mm);
84 }
85 
86 unsigned long task_vsize(struct mm_struct *mm)
87 {
88 	return PAGE_SIZE * mm->total_vm;
89 }
90 
91 unsigned long task_statm(struct mm_struct *mm,
92 			 unsigned long *shared, unsigned long *text,
93 			 unsigned long *data, unsigned long *resident)
94 {
95 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
96 			get_mm_counter(mm, MM_SHMEMPAGES);
97 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
98 								>> PAGE_SHIFT;
99 	*data = mm->data_vm + mm->stack_vm;
100 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
101 	return mm->total_vm;
102 }
103 
104 #ifdef CONFIG_NUMA
105 /*
106  * Save get_task_policy() for show_numa_map().
107  */
108 static void hold_task_mempolicy(struct proc_maps_private *priv)
109 {
110 	struct task_struct *task = priv->task;
111 
112 	task_lock(task);
113 	priv->task_mempolicy = get_task_policy(task);
114 	mpol_get(priv->task_mempolicy);
115 	task_unlock(task);
116 }
117 static void release_task_mempolicy(struct proc_maps_private *priv)
118 {
119 	mpol_put(priv->task_mempolicy);
120 }
121 #else
122 static void hold_task_mempolicy(struct proc_maps_private *priv)
123 {
124 }
125 static void release_task_mempolicy(struct proc_maps_private *priv)
126 {
127 }
128 #endif
129 
130 static void vma_stop(struct proc_maps_private *priv)
131 {
132 	struct mm_struct *mm = priv->mm;
133 
134 	release_task_mempolicy(priv);
135 	up_read(&mm->mmap_sem);
136 	mmput(mm);
137 }
138 
139 static struct vm_area_struct *
140 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
141 {
142 	if (vma == priv->tail_vma)
143 		return NULL;
144 	return vma->vm_next ?: priv->tail_vma;
145 }
146 
147 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
148 {
149 	if (m->count < m->size)	/* vma is copied successfully */
150 		m->version = m_next_vma(m->private, vma) ? vma->vm_start : -1UL;
151 }
152 
153 static void *m_start(struct seq_file *m, loff_t *ppos)
154 {
155 	struct proc_maps_private *priv = m->private;
156 	unsigned long last_addr = m->version;
157 	struct mm_struct *mm;
158 	struct vm_area_struct *vma;
159 	unsigned int pos = *ppos;
160 
161 	/* See m_cache_vma(). Zero at the start or after lseek. */
162 	if (last_addr == -1UL)
163 		return NULL;
164 
165 	priv->task = get_proc_task(priv->inode);
166 	if (!priv->task)
167 		return ERR_PTR(-ESRCH);
168 
169 	mm = priv->mm;
170 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
171 		return NULL;
172 
173 	down_read(&mm->mmap_sem);
174 	hold_task_mempolicy(priv);
175 	priv->tail_vma = get_gate_vma(mm);
176 
177 	if (last_addr) {
178 		vma = find_vma(mm, last_addr);
179 		if (vma && (vma = m_next_vma(priv, vma)))
180 			return vma;
181 	}
182 
183 	m->version = 0;
184 	if (pos < mm->map_count) {
185 		for (vma = mm->mmap; pos; pos--) {
186 			m->version = vma->vm_start;
187 			vma = vma->vm_next;
188 		}
189 		return vma;
190 	}
191 
192 	/* we do not bother to update m->version in this case */
193 	if (pos == mm->map_count && priv->tail_vma)
194 		return priv->tail_vma;
195 
196 	vma_stop(priv);
197 	return NULL;
198 }
199 
200 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
201 {
202 	struct proc_maps_private *priv = m->private;
203 	struct vm_area_struct *next;
204 
205 	(*pos)++;
206 	next = m_next_vma(priv, v);
207 	if (!next)
208 		vma_stop(priv);
209 	return next;
210 }
211 
212 static void m_stop(struct seq_file *m, void *v)
213 {
214 	struct proc_maps_private *priv = m->private;
215 
216 	if (!IS_ERR_OR_NULL(v))
217 		vma_stop(priv);
218 	if (priv->task) {
219 		put_task_struct(priv->task);
220 		priv->task = NULL;
221 	}
222 }
223 
224 static int proc_maps_open(struct inode *inode, struct file *file,
225 			const struct seq_operations *ops, int psize)
226 {
227 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
228 
229 	if (!priv)
230 		return -ENOMEM;
231 
232 	priv->inode = inode;
233 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
234 	if (IS_ERR(priv->mm)) {
235 		int err = PTR_ERR(priv->mm);
236 
237 		seq_release_private(inode, file);
238 		return err;
239 	}
240 
241 	return 0;
242 }
243 
244 static int proc_map_release(struct inode *inode, struct file *file)
245 {
246 	struct seq_file *seq = file->private_data;
247 	struct proc_maps_private *priv = seq->private;
248 
249 	if (priv->mm)
250 		mmdrop(priv->mm);
251 
252 	return seq_release_private(inode, file);
253 }
254 
255 static int do_maps_open(struct inode *inode, struct file *file,
256 			const struct seq_operations *ops)
257 {
258 	return proc_maps_open(inode, file, ops,
259 				sizeof(struct proc_maps_private));
260 }
261 
262 /*
263  * Indicate if the VMA is a stack for the given task; for
264  * /proc/PID/maps that is the stack of the main task.
265  */
266 static int is_stack(struct proc_maps_private *priv,
267 		    struct vm_area_struct *vma, int is_pid)
268 {
269 	int stack = 0;
270 
271 	if (is_pid) {
272 		stack = vma->vm_start <= vma->vm_mm->start_stack &&
273 			vma->vm_end >= vma->vm_mm->start_stack;
274 	} else {
275 		struct inode *inode = priv->inode;
276 		struct task_struct *task;
277 
278 		rcu_read_lock();
279 		task = pid_task(proc_pid(inode), PIDTYPE_PID);
280 		if (task)
281 			stack = vma_is_stack_for_task(vma, task);
282 		rcu_read_unlock();
283 	}
284 	return stack;
285 }
286 
287 static void
288 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
289 {
290 	struct mm_struct *mm = vma->vm_mm;
291 	struct file *file = vma->vm_file;
292 	struct proc_maps_private *priv = m->private;
293 	vm_flags_t flags = vma->vm_flags;
294 	unsigned long ino = 0;
295 	unsigned long long pgoff = 0;
296 	unsigned long start, end;
297 	dev_t dev = 0;
298 	const char *name = NULL;
299 
300 	if (file) {
301 		struct inode *inode = file_inode(vma->vm_file);
302 		dev = inode->i_sb->s_dev;
303 		ino = inode->i_ino;
304 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
305 	}
306 
307 	/* We don't show the stack guard page in /proc/maps */
308 	start = vma->vm_start;
309 	if (stack_guard_page_start(vma, start))
310 		start += PAGE_SIZE;
311 	end = vma->vm_end;
312 	if (stack_guard_page_end(vma, end))
313 		end -= PAGE_SIZE;
314 
315 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
316 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
317 			start,
318 			end,
319 			flags & VM_READ ? 'r' : '-',
320 			flags & VM_WRITE ? 'w' : '-',
321 			flags & VM_EXEC ? 'x' : '-',
322 			flags & VM_MAYSHARE ? 's' : 'p',
323 			pgoff,
324 			MAJOR(dev), MINOR(dev), ino);
325 
326 	/*
327 	 * Print the dentry name for named mappings, and a
328 	 * special [heap] marker for the heap:
329 	 */
330 	if (file) {
331 		seq_pad(m, ' ');
332 		seq_file_path(m, file, "\n");
333 		goto done;
334 	}
335 
336 	if (vma->vm_ops && vma->vm_ops->name) {
337 		name = vma->vm_ops->name(vma);
338 		if (name)
339 			goto done;
340 	}
341 
342 	name = arch_vma_name(vma);
343 	if (!name) {
344 		if (!mm) {
345 			name = "[vdso]";
346 			goto done;
347 		}
348 
349 		if (vma->vm_start <= mm->brk &&
350 		    vma->vm_end >= mm->start_brk) {
351 			name = "[heap]";
352 			goto done;
353 		}
354 
355 		if (is_stack(priv, vma, is_pid))
356 			name = "[stack]";
357 	}
358 
359 done:
360 	if (name) {
361 		seq_pad(m, ' ');
362 		seq_puts(m, name);
363 	}
364 	seq_putc(m, '\n');
365 }
366 
367 static int show_map(struct seq_file *m, void *v, int is_pid)
368 {
369 	show_map_vma(m, v, is_pid);
370 	m_cache_vma(m, v);
371 	return 0;
372 }
373 
374 static int show_pid_map(struct seq_file *m, void *v)
375 {
376 	return show_map(m, v, 1);
377 }
378 
379 static int show_tid_map(struct seq_file *m, void *v)
380 {
381 	return show_map(m, v, 0);
382 }
383 
384 static const struct seq_operations proc_pid_maps_op = {
385 	.start	= m_start,
386 	.next	= m_next,
387 	.stop	= m_stop,
388 	.show	= show_pid_map
389 };
390 
391 static const struct seq_operations proc_tid_maps_op = {
392 	.start	= m_start,
393 	.next	= m_next,
394 	.stop	= m_stop,
395 	.show	= show_tid_map
396 };
397 
398 static int pid_maps_open(struct inode *inode, struct file *file)
399 {
400 	return do_maps_open(inode, file, &proc_pid_maps_op);
401 }
402 
403 static int tid_maps_open(struct inode *inode, struct file *file)
404 {
405 	return do_maps_open(inode, file, &proc_tid_maps_op);
406 }
407 
408 const struct file_operations proc_pid_maps_operations = {
409 	.open		= pid_maps_open,
410 	.read		= seq_read,
411 	.llseek		= seq_lseek,
412 	.release	= proc_map_release,
413 };
414 
415 const struct file_operations proc_tid_maps_operations = {
416 	.open		= tid_maps_open,
417 	.read		= seq_read,
418 	.llseek		= seq_lseek,
419 	.release	= proc_map_release,
420 };
421 
422 /*
423  * Proportional Set Size(PSS): my share of RSS.
424  *
425  * PSS of a process is the count of pages it has in memory, where each
426  * page is divided by the number of processes sharing it.  So if a
427  * process has 1000 pages all to itself, and 1000 shared with one other
428  * process, its PSS will be 1500.
429  *
430  * To keep (accumulated) division errors low, we adopt a 64bit
431  * fixed-point pss counter to minimize division errors. So (pss >>
432  * PSS_SHIFT) would be the real byte count.
433  *
434  * A shift of 12 before division means (assuming 4K page size):
435  * 	- 1M 3-user-pages add up to 8KB errors;
436  * 	- supports mapcount up to 2^24, or 16M;
437  * 	- supports PSS up to 2^52 bytes, or 4PB.
438  */
439 #define PSS_SHIFT 12
440 
441 #ifdef CONFIG_PROC_PAGE_MONITOR
442 struct mem_size_stats {
443 	unsigned long resident;
444 	unsigned long shared_clean;
445 	unsigned long shared_dirty;
446 	unsigned long private_clean;
447 	unsigned long private_dirty;
448 	unsigned long referenced;
449 	unsigned long anonymous;
450 	unsigned long anonymous_thp;
451 	unsigned long shmem_thp;
452 	unsigned long swap;
453 	unsigned long shared_hugetlb;
454 	unsigned long private_hugetlb;
455 	u64 pss;
456 	u64 swap_pss;
457 	bool check_shmem_swap;
458 };
459 
460 static void smaps_account(struct mem_size_stats *mss, struct page *page,
461 		bool compound, bool young, bool dirty)
462 {
463 	int i, nr = compound ? 1 << compound_order(page) : 1;
464 	unsigned long size = nr * PAGE_SIZE;
465 
466 	if (PageAnon(page))
467 		mss->anonymous += size;
468 
469 	mss->resident += size;
470 	/* Accumulate the size in pages that have been accessed. */
471 	if (young || page_is_young(page) || PageReferenced(page))
472 		mss->referenced += size;
473 
474 	/*
475 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
476 	 * If any subpage of the compound page mapped with PTE it would elevate
477 	 * page_count().
478 	 */
479 	if (page_count(page) == 1) {
480 		if (dirty || PageDirty(page))
481 			mss->private_dirty += size;
482 		else
483 			mss->private_clean += size;
484 		mss->pss += (u64)size << PSS_SHIFT;
485 		return;
486 	}
487 
488 	for (i = 0; i < nr; i++, page++) {
489 		int mapcount = page_mapcount(page);
490 
491 		if (mapcount >= 2) {
492 			if (dirty || PageDirty(page))
493 				mss->shared_dirty += PAGE_SIZE;
494 			else
495 				mss->shared_clean += PAGE_SIZE;
496 			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
497 		} else {
498 			if (dirty || PageDirty(page))
499 				mss->private_dirty += PAGE_SIZE;
500 			else
501 				mss->private_clean += PAGE_SIZE;
502 			mss->pss += PAGE_SIZE << PSS_SHIFT;
503 		}
504 	}
505 }
506 
507 #ifdef CONFIG_SHMEM
508 static int smaps_pte_hole(unsigned long addr, unsigned long end,
509 		struct mm_walk *walk)
510 {
511 	struct mem_size_stats *mss = walk->private;
512 
513 	mss->swap += shmem_partial_swap_usage(
514 			walk->vma->vm_file->f_mapping, addr, end);
515 
516 	return 0;
517 }
518 #endif
519 
520 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
521 		struct mm_walk *walk)
522 {
523 	struct mem_size_stats *mss = walk->private;
524 	struct vm_area_struct *vma = walk->vma;
525 	struct page *page = NULL;
526 
527 	if (pte_present(*pte)) {
528 		page = vm_normal_page(vma, addr, *pte);
529 	} else if (is_swap_pte(*pte)) {
530 		swp_entry_t swpent = pte_to_swp_entry(*pte);
531 
532 		if (!non_swap_entry(swpent)) {
533 			int mapcount;
534 
535 			mss->swap += PAGE_SIZE;
536 			mapcount = swp_swapcount(swpent);
537 			if (mapcount >= 2) {
538 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
539 
540 				do_div(pss_delta, mapcount);
541 				mss->swap_pss += pss_delta;
542 			} else {
543 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
544 			}
545 		} else if (is_migration_entry(swpent))
546 			page = migration_entry_to_page(swpent);
547 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
548 							&& pte_none(*pte))) {
549 		page = find_get_entry(vma->vm_file->f_mapping,
550 						linear_page_index(vma, addr));
551 		if (!page)
552 			return;
553 
554 		if (radix_tree_exceptional_entry(page))
555 			mss->swap += PAGE_SIZE;
556 		else
557 			put_page(page);
558 
559 		return;
560 	}
561 
562 	if (!page)
563 		return;
564 
565 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
566 }
567 
568 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
569 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
570 		struct mm_walk *walk)
571 {
572 	struct mem_size_stats *mss = walk->private;
573 	struct vm_area_struct *vma = walk->vma;
574 	struct page *page;
575 
576 	/* FOLL_DUMP will return -EFAULT on huge zero page */
577 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
578 	if (IS_ERR_OR_NULL(page))
579 		return;
580 	if (PageAnon(page))
581 		mss->anonymous_thp += HPAGE_PMD_SIZE;
582 	else if (PageSwapBacked(page))
583 		mss->shmem_thp += HPAGE_PMD_SIZE;
584 	else if (is_zone_device_page(page))
585 		/* pass */;
586 	else
587 		VM_BUG_ON_PAGE(1, page);
588 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
589 }
590 #else
591 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
592 		struct mm_walk *walk)
593 {
594 }
595 #endif
596 
597 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
598 			   struct mm_walk *walk)
599 {
600 	struct vm_area_struct *vma = walk->vma;
601 	pte_t *pte;
602 	spinlock_t *ptl;
603 
604 	ptl = pmd_trans_huge_lock(pmd, vma);
605 	if (ptl) {
606 		smaps_pmd_entry(pmd, addr, walk);
607 		spin_unlock(ptl);
608 		return 0;
609 	}
610 
611 	if (pmd_trans_unstable(pmd))
612 		return 0;
613 	/*
614 	 * The mmap_sem held all the way back in m_start() is what
615 	 * keeps khugepaged out of here and from collapsing things
616 	 * in here.
617 	 */
618 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
619 	for (; addr != end; pte++, addr += PAGE_SIZE)
620 		smaps_pte_entry(pte, addr, walk);
621 	pte_unmap_unlock(pte - 1, ptl);
622 	cond_resched();
623 	return 0;
624 }
625 
626 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
627 {
628 	/*
629 	 * Don't forget to update Documentation/ on changes.
630 	 */
631 	static const char mnemonics[BITS_PER_LONG][2] = {
632 		/*
633 		 * In case if we meet a flag we don't know about.
634 		 */
635 		[0 ... (BITS_PER_LONG-1)] = "??",
636 
637 		[ilog2(VM_READ)]	= "rd",
638 		[ilog2(VM_WRITE)]	= "wr",
639 		[ilog2(VM_EXEC)]	= "ex",
640 		[ilog2(VM_SHARED)]	= "sh",
641 		[ilog2(VM_MAYREAD)]	= "mr",
642 		[ilog2(VM_MAYWRITE)]	= "mw",
643 		[ilog2(VM_MAYEXEC)]	= "me",
644 		[ilog2(VM_MAYSHARE)]	= "ms",
645 		[ilog2(VM_GROWSDOWN)]	= "gd",
646 		[ilog2(VM_PFNMAP)]	= "pf",
647 		[ilog2(VM_DENYWRITE)]	= "dw",
648 #ifdef CONFIG_X86_INTEL_MPX
649 		[ilog2(VM_MPX)]		= "mp",
650 #endif
651 		[ilog2(VM_LOCKED)]	= "lo",
652 		[ilog2(VM_IO)]		= "io",
653 		[ilog2(VM_SEQ_READ)]	= "sr",
654 		[ilog2(VM_RAND_READ)]	= "rr",
655 		[ilog2(VM_DONTCOPY)]	= "dc",
656 		[ilog2(VM_DONTEXPAND)]	= "de",
657 		[ilog2(VM_ACCOUNT)]	= "ac",
658 		[ilog2(VM_NORESERVE)]	= "nr",
659 		[ilog2(VM_HUGETLB)]	= "ht",
660 		[ilog2(VM_ARCH_1)]	= "ar",
661 		[ilog2(VM_DONTDUMP)]	= "dd",
662 #ifdef CONFIG_MEM_SOFT_DIRTY
663 		[ilog2(VM_SOFTDIRTY)]	= "sd",
664 #endif
665 		[ilog2(VM_MIXEDMAP)]	= "mm",
666 		[ilog2(VM_HUGEPAGE)]	= "hg",
667 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
668 		[ilog2(VM_MERGEABLE)]	= "mg",
669 		[ilog2(VM_UFFD_MISSING)]= "um",
670 		[ilog2(VM_UFFD_WP)]	= "uw",
671 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
672 		/* These come out via ProtectionKey: */
673 		[ilog2(VM_PKEY_BIT0)]	= "",
674 		[ilog2(VM_PKEY_BIT1)]	= "",
675 		[ilog2(VM_PKEY_BIT2)]	= "",
676 		[ilog2(VM_PKEY_BIT3)]	= "",
677 #endif
678 	};
679 	size_t i;
680 
681 	seq_puts(m, "VmFlags: ");
682 	for (i = 0; i < BITS_PER_LONG; i++) {
683 		if (!mnemonics[i][0])
684 			continue;
685 		if (vma->vm_flags & (1UL << i)) {
686 			seq_printf(m, "%c%c ",
687 				   mnemonics[i][0], mnemonics[i][1]);
688 		}
689 	}
690 	seq_putc(m, '\n');
691 }
692 
693 #ifdef CONFIG_HUGETLB_PAGE
694 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
695 				 unsigned long addr, unsigned long end,
696 				 struct mm_walk *walk)
697 {
698 	struct mem_size_stats *mss = walk->private;
699 	struct vm_area_struct *vma = walk->vma;
700 	struct page *page = NULL;
701 
702 	if (pte_present(*pte)) {
703 		page = vm_normal_page(vma, addr, *pte);
704 	} else if (is_swap_pte(*pte)) {
705 		swp_entry_t swpent = pte_to_swp_entry(*pte);
706 
707 		if (is_migration_entry(swpent))
708 			page = migration_entry_to_page(swpent);
709 	}
710 	if (page) {
711 		int mapcount = page_mapcount(page);
712 
713 		if (mapcount >= 2)
714 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
715 		else
716 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
717 	}
718 	return 0;
719 }
720 #endif /* HUGETLB_PAGE */
721 
722 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
723 {
724 }
725 
726 static int show_smap(struct seq_file *m, void *v, int is_pid)
727 {
728 	struct vm_area_struct *vma = v;
729 	struct mem_size_stats mss;
730 	struct mm_walk smaps_walk = {
731 		.pmd_entry = smaps_pte_range,
732 #ifdef CONFIG_HUGETLB_PAGE
733 		.hugetlb_entry = smaps_hugetlb_range,
734 #endif
735 		.mm = vma->vm_mm,
736 		.private = &mss,
737 	};
738 
739 	memset(&mss, 0, sizeof mss);
740 
741 #ifdef CONFIG_SHMEM
742 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
743 		/*
744 		 * For shared or readonly shmem mappings we know that all
745 		 * swapped out pages belong to the shmem object, and we can
746 		 * obtain the swap value much more efficiently. For private
747 		 * writable mappings, we might have COW pages that are
748 		 * not affected by the parent swapped out pages of the shmem
749 		 * object, so we have to distinguish them during the page walk.
750 		 * Unless we know that the shmem object (or the part mapped by
751 		 * our VMA) has no swapped out pages at all.
752 		 */
753 		unsigned long shmem_swapped = shmem_swap_usage(vma);
754 
755 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
756 					!(vma->vm_flags & VM_WRITE)) {
757 			mss.swap = shmem_swapped;
758 		} else {
759 			mss.check_shmem_swap = true;
760 			smaps_walk.pte_hole = smaps_pte_hole;
761 		}
762 	}
763 #endif
764 
765 	/* mmap_sem is held in m_start */
766 	walk_page_vma(vma, &smaps_walk);
767 
768 	show_map_vma(m, vma, is_pid);
769 
770 	seq_printf(m,
771 		   "Size:           %8lu kB\n"
772 		   "Rss:            %8lu kB\n"
773 		   "Pss:            %8lu kB\n"
774 		   "Shared_Clean:   %8lu kB\n"
775 		   "Shared_Dirty:   %8lu kB\n"
776 		   "Private_Clean:  %8lu kB\n"
777 		   "Private_Dirty:  %8lu kB\n"
778 		   "Referenced:     %8lu kB\n"
779 		   "Anonymous:      %8lu kB\n"
780 		   "AnonHugePages:  %8lu kB\n"
781 		   "ShmemPmdMapped: %8lu kB\n"
782 		   "Shared_Hugetlb: %8lu kB\n"
783 		   "Private_Hugetlb: %7lu kB\n"
784 		   "Swap:           %8lu kB\n"
785 		   "SwapPss:        %8lu kB\n"
786 		   "KernelPageSize: %8lu kB\n"
787 		   "MMUPageSize:    %8lu kB\n"
788 		   "Locked:         %8lu kB\n",
789 		   (vma->vm_end - vma->vm_start) >> 10,
790 		   mss.resident >> 10,
791 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
792 		   mss.shared_clean  >> 10,
793 		   mss.shared_dirty  >> 10,
794 		   mss.private_clean >> 10,
795 		   mss.private_dirty >> 10,
796 		   mss.referenced >> 10,
797 		   mss.anonymous >> 10,
798 		   mss.anonymous_thp >> 10,
799 		   mss.shmem_thp >> 10,
800 		   mss.shared_hugetlb >> 10,
801 		   mss.private_hugetlb >> 10,
802 		   mss.swap >> 10,
803 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
804 		   vma_kernel_pagesize(vma) >> 10,
805 		   vma_mmu_pagesize(vma) >> 10,
806 		   (vma->vm_flags & VM_LOCKED) ?
807 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
808 
809 	arch_show_smap(m, vma);
810 	show_smap_vma_flags(m, vma);
811 	m_cache_vma(m, vma);
812 	return 0;
813 }
814 
815 static int show_pid_smap(struct seq_file *m, void *v)
816 {
817 	return show_smap(m, v, 1);
818 }
819 
820 static int show_tid_smap(struct seq_file *m, void *v)
821 {
822 	return show_smap(m, v, 0);
823 }
824 
825 static const struct seq_operations proc_pid_smaps_op = {
826 	.start	= m_start,
827 	.next	= m_next,
828 	.stop	= m_stop,
829 	.show	= show_pid_smap
830 };
831 
832 static const struct seq_operations proc_tid_smaps_op = {
833 	.start	= m_start,
834 	.next	= m_next,
835 	.stop	= m_stop,
836 	.show	= show_tid_smap
837 };
838 
839 static int pid_smaps_open(struct inode *inode, struct file *file)
840 {
841 	return do_maps_open(inode, file, &proc_pid_smaps_op);
842 }
843 
844 static int tid_smaps_open(struct inode *inode, struct file *file)
845 {
846 	return do_maps_open(inode, file, &proc_tid_smaps_op);
847 }
848 
849 const struct file_operations proc_pid_smaps_operations = {
850 	.open		= pid_smaps_open,
851 	.read		= seq_read,
852 	.llseek		= seq_lseek,
853 	.release	= proc_map_release,
854 };
855 
856 const struct file_operations proc_tid_smaps_operations = {
857 	.open		= tid_smaps_open,
858 	.read		= seq_read,
859 	.llseek		= seq_lseek,
860 	.release	= proc_map_release,
861 };
862 
863 enum clear_refs_types {
864 	CLEAR_REFS_ALL = 1,
865 	CLEAR_REFS_ANON,
866 	CLEAR_REFS_MAPPED,
867 	CLEAR_REFS_SOFT_DIRTY,
868 	CLEAR_REFS_MM_HIWATER_RSS,
869 	CLEAR_REFS_LAST,
870 };
871 
872 struct clear_refs_private {
873 	enum clear_refs_types type;
874 };
875 
876 #ifdef CONFIG_MEM_SOFT_DIRTY
877 static inline void clear_soft_dirty(struct vm_area_struct *vma,
878 		unsigned long addr, pte_t *pte)
879 {
880 	/*
881 	 * The soft-dirty tracker uses #PF-s to catch writes
882 	 * to pages, so write-protect the pte as well. See the
883 	 * Documentation/vm/soft-dirty.txt for full description
884 	 * of how soft-dirty works.
885 	 */
886 	pte_t ptent = *pte;
887 
888 	if (pte_present(ptent)) {
889 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
890 		ptent = pte_wrprotect(ptent);
891 		ptent = pte_clear_soft_dirty(ptent);
892 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
893 	} else if (is_swap_pte(ptent)) {
894 		ptent = pte_swp_clear_soft_dirty(ptent);
895 		set_pte_at(vma->vm_mm, addr, pte, ptent);
896 	}
897 }
898 #else
899 static inline void clear_soft_dirty(struct vm_area_struct *vma,
900 		unsigned long addr, pte_t *pte)
901 {
902 }
903 #endif
904 
905 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
906 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
907 		unsigned long addr, pmd_t *pmdp)
908 {
909 	pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
910 
911 	pmd = pmd_wrprotect(pmd);
912 	pmd = pmd_clear_soft_dirty(pmd);
913 
914 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
915 }
916 #else
917 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
918 		unsigned long addr, pmd_t *pmdp)
919 {
920 }
921 #endif
922 
923 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
924 				unsigned long end, struct mm_walk *walk)
925 {
926 	struct clear_refs_private *cp = walk->private;
927 	struct vm_area_struct *vma = walk->vma;
928 	pte_t *pte, ptent;
929 	spinlock_t *ptl;
930 	struct page *page;
931 
932 	ptl = pmd_trans_huge_lock(pmd, vma);
933 	if (ptl) {
934 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
935 			clear_soft_dirty_pmd(vma, addr, pmd);
936 			goto out;
937 		}
938 
939 		page = pmd_page(*pmd);
940 
941 		/* Clear accessed and referenced bits. */
942 		pmdp_test_and_clear_young(vma, addr, pmd);
943 		test_and_clear_page_young(page);
944 		ClearPageReferenced(page);
945 out:
946 		spin_unlock(ptl);
947 		return 0;
948 	}
949 
950 	if (pmd_trans_unstable(pmd))
951 		return 0;
952 
953 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
954 	for (; addr != end; pte++, addr += PAGE_SIZE) {
955 		ptent = *pte;
956 
957 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
958 			clear_soft_dirty(vma, addr, pte);
959 			continue;
960 		}
961 
962 		if (!pte_present(ptent))
963 			continue;
964 
965 		page = vm_normal_page(vma, addr, ptent);
966 		if (!page)
967 			continue;
968 
969 		/* Clear accessed and referenced bits. */
970 		ptep_test_and_clear_young(vma, addr, pte);
971 		test_and_clear_page_young(page);
972 		ClearPageReferenced(page);
973 	}
974 	pte_unmap_unlock(pte - 1, ptl);
975 	cond_resched();
976 	return 0;
977 }
978 
979 static int clear_refs_test_walk(unsigned long start, unsigned long end,
980 				struct mm_walk *walk)
981 {
982 	struct clear_refs_private *cp = walk->private;
983 	struct vm_area_struct *vma = walk->vma;
984 
985 	if (vma->vm_flags & VM_PFNMAP)
986 		return 1;
987 
988 	/*
989 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
990 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
991 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
992 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
993 	 */
994 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
995 		return 1;
996 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
997 		return 1;
998 	return 0;
999 }
1000 
1001 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1002 				size_t count, loff_t *ppos)
1003 {
1004 	struct task_struct *task;
1005 	char buffer[PROC_NUMBUF];
1006 	struct mm_struct *mm;
1007 	struct vm_area_struct *vma;
1008 	enum clear_refs_types type;
1009 	int itype;
1010 	int rv;
1011 
1012 	memset(buffer, 0, sizeof(buffer));
1013 	if (count > sizeof(buffer) - 1)
1014 		count = sizeof(buffer) - 1;
1015 	if (copy_from_user(buffer, buf, count))
1016 		return -EFAULT;
1017 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1018 	if (rv < 0)
1019 		return rv;
1020 	type = (enum clear_refs_types)itype;
1021 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1022 		return -EINVAL;
1023 
1024 	task = get_proc_task(file_inode(file));
1025 	if (!task)
1026 		return -ESRCH;
1027 	mm = get_task_mm(task);
1028 	if (mm) {
1029 		struct clear_refs_private cp = {
1030 			.type = type,
1031 		};
1032 		struct mm_walk clear_refs_walk = {
1033 			.pmd_entry = clear_refs_pte_range,
1034 			.test_walk = clear_refs_test_walk,
1035 			.mm = mm,
1036 			.private = &cp,
1037 		};
1038 
1039 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1040 			if (down_write_killable(&mm->mmap_sem)) {
1041 				count = -EINTR;
1042 				goto out_mm;
1043 			}
1044 
1045 			/*
1046 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1047 			 * resident set size to this mm's current rss value.
1048 			 */
1049 			reset_mm_hiwater_rss(mm);
1050 			up_write(&mm->mmap_sem);
1051 			goto out_mm;
1052 		}
1053 
1054 		down_read(&mm->mmap_sem);
1055 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1056 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1057 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1058 					continue;
1059 				up_read(&mm->mmap_sem);
1060 				if (down_write_killable(&mm->mmap_sem)) {
1061 					count = -EINTR;
1062 					goto out_mm;
1063 				}
1064 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1065 					vma->vm_flags &= ~VM_SOFTDIRTY;
1066 					vma_set_page_prot(vma);
1067 				}
1068 				downgrade_write(&mm->mmap_sem);
1069 				break;
1070 			}
1071 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1072 		}
1073 		walk_page_range(0, ~0UL, &clear_refs_walk);
1074 		if (type == CLEAR_REFS_SOFT_DIRTY)
1075 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1076 		flush_tlb_mm(mm);
1077 		up_read(&mm->mmap_sem);
1078 out_mm:
1079 		mmput(mm);
1080 	}
1081 	put_task_struct(task);
1082 
1083 	return count;
1084 }
1085 
1086 const struct file_operations proc_clear_refs_operations = {
1087 	.write		= clear_refs_write,
1088 	.llseek		= noop_llseek,
1089 };
1090 
1091 typedef struct {
1092 	u64 pme;
1093 } pagemap_entry_t;
1094 
1095 struct pagemapread {
1096 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1097 	pagemap_entry_t *buffer;
1098 	bool show_pfn;
1099 };
1100 
1101 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1102 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1103 
1104 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1105 #define PM_PFRAME_BITS		55
1106 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1107 #define PM_SOFT_DIRTY		BIT_ULL(55)
1108 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1109 #define PM_FILE			BIT_ULL(61)
1110 #define PM_SWAP			BIT_ULL(62)
1111 #define PM_PRESENT		BIT_ULL(63)
1112 
1113 #define PM_END_OF_BUFFER    1
1114 
1115 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1116 {
1117 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1118 }
1119 
1120 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1121 			  struct pagemapread *pm)
1122 {
1123 	pm->buffer[pm->pos++] = *pme;
1124 	if (pm->pos >= pm->len)
1125 		return PM_END_OF_BUFFER;
1126 	return 0;
1127 }
1128 
1129 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1130 				struct mm_walk *walk)
1131 {
1132 	struct pagemapread *pm = walk->private;
1133 	unsigned long addr = start;
1134 	int err = 0;
1135 
1136 	while (addr < end) {
1137 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1138 		pagemap_entry_t pme = make_pme(0, 0);
1139 		/* End of address space hole, which we mark as non-present. */
1140 		unsigned long hole_end;
1141 
1142 		if (vma)
1143 			hole_end = min(end, vma->vm_start);
1144 		else
1145 			hole_end = end;
1146 
1147 		for (; addr < hole_end; addr += PAGE_SIZE) {
1148 			err = add_to_pagemap(addr, &pme, pm);
1149 			if (err)
1150 				goto out;
1151 		}
1152 
1153 		if (!vma)
1154 			break;
1155 
1156 		/* Addresses in the VMA. */
1157 		if (vma->vm_flags & VM_SOFTDIRTY)
1158 			pme = make_pme(0, PM_SOFT_DIRTY);
1159 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1160 			err = add_to_pagemap(addr, &pme, pm);
1161 			if (err)
1162 				goto out;
1163 		}
1164 	}
1165 out:
1166 	return err;
1167 }
1168 
1169 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1170 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1171 {
1172 	u64 frame = 0, flags = 0;
1173 	struct page *page = NULL;
1174 
1175 	if (pte_present(pte)) {
1176 		if (pm->show_pfn)
1177 			frame = pte_pfn(pte);
1178 		flags |= PM_PRESENT;
1179 		page = vm_normal_page(vma, addr, pte);
1180 		if (pte_soft_dirty(pte))
1181 			flags |= PM_SOFT_DIRTY;
1182 	} else if (is_swap_pte(pte)) {
1183 		swp_entry_t entry;
1184 		if (pte_swp_soft_dirty(pte))
1185 			flags |= PM_SOFT_DIRTY;
1186 		entry = pte_to_swp_entry(pte);
1187 		frame = swp_type(entry) |
1188 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1189 		flags |= PM_SWAP;
1190 		if (is_migration_entry(entry))
1191 			page = migration_entry_to_page(entry);
1192 	}
1193 
1194 	if (page && !PageAnon(page))
1195 		flags |= PM_FILE;
1196 	if (page && page_mapcount(page) == 1)
1197 		flags |= PM_MMAP_EXCLUSIVE;
1198 	if (vma->vm_flags & VM_SOFTDIRTY)
1199 		flags |= PM_SOFT_DIRTY;
1200 
1201 	return make_pme(frame, flags);
1202 }
1203 
1204 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1205 			     struct mm_walk *walk)
1206 {
1207 	struct vm_area_struct *vma = walk->vma;
1208 	struct pagemapread *pm = walk->private;
1209 	spinlock_t *ptl;
1210 	pte_t *pte, *orig_pte;
1211 	int err = 0;
1212 
1213 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1214 	ptl = pmd_trans_huge_lock(pmdp, vma);
1215 	if (ptl) {
1216 		u64 flags = 0, frame = 0;
1217 		pmd_t pmd = *pmdp;
1218 
1219 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1220 			flags |= PM_SOFT_DIRTY;
1221 
1222 		/*
1223 		 * Currently pmd for thp is always present because thp
1224 		 * can not be swapped-out, migrated, or HWPOISONed
1225 		 * (split in such cases instead.)
1226 		 * This if-check is just to prepare for future implementation.
1227 		 */
1228 		if (pmd_present(pmd)) {
1229 			struct page *page = pmd_page(pmd);
1230 
1231 			if (page_mapcount(page) == 1)
1232 				flags |= PM_MMAP_EXCLUSIVE;
1233 
1234 			flags |= PM_PRESENT;
1235 			if (pm->show_pfn)
1236 				frame = pmd_pfn(pmd) +
1237 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1238 		}
1239 
1240 		for (; addr != end; addr += PAGE_SIZE) {
1241 			pagemap_entry_t pme = make_pme(frame, flags);
1242 
1243 			err = add_to_pagemap(addr, &pme, pm);
1244 			if (err)
1245 				break;
1246 			if (pm->show_pfn && (flags & PM_PRESENT))
1247 				frame++;
1248 		}
1249 		spin_unlock(ptl);
1250 		return err;
1251 	}
1252 
1253 	if (pmd_trans_unstable(pmdp))
1254 		return 0;
1255 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1256 
1257 	/*
1258 	 * We can assume that @vma always points to a valid one and @end never
1259 	 * goes beyond vma->vm_end.
1260 	 */
1261 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1262 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1263 		pagemap_entry_t pme;
1264 
1265 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1266 		err = add_to_pagemap(addr, &pme, pm);
1267 		if (err)
1268 			break;
1269 	}
1270 	pte_unmap_unlock(orig_pte, ptl);
1271 
1272 	cond_resched();
1273 
1274 	return err;
1275 }
1276 
1277 #ifdef CONFIG_HUGETLB_PAGE
1278 /* This function walks within one hugetlb entry in the single call */
1279 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1280 				 unsigned long addr, unsigned long end,
1281 				 struct mm_walk *walk)
1282 {
1283 	struct pagemapread *pm = walk->private;
1284 	struct vm_area_struct *vma = walk->vma;
1285 	u64 flags = 0, frame = 0;
1286 	int err = 0;
1287 	pte_t pte;
1288 
1289 	if (vma->vm_flags & VM_SOFTDIRTY)
1290 		flags |= PM_SOFT_DIRTY;
1291 
1292 	pte = huge_ptep_get(ptep);
1293 	if (pte_present(pte)) {
1294 		struct page *page = pte_page(pte);
1295 
1296 		if (!PageAnon(page))
1297 			flags |= PM_FILE;
1298 
1299 		if (page_mapcount(page) == 1)
1300 			flags |= PM_MMAP_EXCLUSIVE;
1301 
1302 		flags |= PM_PRESENT;
1303 		if (pm->show_pfn)
1304 			frame = pte_pfn(pte) +
1305 				((addr & ~hmask) >> PAGE_SHIFT);
1306 	}
1307 
1308 	for (; addr != end; addr += PAGE_SIZE) {
1309 		pagemap_entry_t pme = make_pme(frame, flags);
1310 
1311 		err = add_to_pagemap(addr, &pme, pm);
1312 		if (err)
1313 			return err;
1314 		if (pm->show_pfn && (flags & PM_PRESENT))
1315 			frame++;
1316 	}
1317 
1318 	cond_resched();
1319 
1320 	return err;
1321 }
1322 #endif /* HUGETLB_PAGE */
1323 
1324 /*
1325  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1326  *
1327  * For each page in the address space, this file contains one 64-bit entry
1328  * consisting of the following:
1329  *
1330  * Bits 0-54  page frame number (PFN) if present
1331  * Bits 0-4   swap type if swapped
1332  * Bits 5-54  swap offset if swapped
1333  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1334  * Bit  56    page exclusively mapped
1335  * Bits 57-60 zero
1336  * Bit  61    page is file-page or shared-anon
1337  * Bit  62    page swapped
1338  * Bit  63    page present
1339  *
1340  * If the page is not present but in swap, then the PFN contains an
1341  * encoding of the swap file number and the page's offset into the
1342  * swap. Unmapped pages return a null PFN. This allows determining
1343  * precisely which pages are mapped (or in swap) and comparing mapped
1344  * pages between processes.
1345  *
1346  * Efficient users of this interface will use /proc/pid/maps to
1347  * determine which areas of memory are actually mapped and llseek to
1348  * skip over unmapped regions.
1349  */
1350 static ssize_t pagemap_read(struct file *file, char __user *buf,
1351 			    size_t count, loff_t *ppos)
1352 {
1353 	struct mm_struct *mm = file->private_data;
1354 	struct pagemapread pm;
1355 	struct mm_walk pagemap_walk = {};
1356 	unsigned long src;
1357 	unsigned long svpfn;
1358 	unsigned long start_vaddr;
1359 	unsigned long end_vaddr;
1360 	int ret = 0, copied = 0;
1361 
1362 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
1363 		goto out;
1364 
1365 	ret = -EINVAL;
1366 	/* file position must be aligned */
1367 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1368 		goto out_mm;
1369 
1370 	ret = 0;
1371 	if (!count)
1372 		goto out_mm;
1373 
1374 	/* do not disclose physical addresses: attack vector */
1375 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1376 
1377 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1378 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1379 	ret = -ENOMEM;
1380 	if (!pm.buffer)
1381 		goto out_mm;
1382 
1383 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1384 	pagemap_walk.pte_hole = pagemap_pte_hole;
1385 #ifdef CONFIG_HUGETLB_PAGE
1386 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1387 #endif
1388 	pagemap_walk.mm = mm;
1389 	pagemap_walk.private = &pm;
1390 
1391 	src = *ppos;
1392 	svpfn = src / PM_ENTRY_BYTES;
1393 	start_vaddr = svpfn << PAGE_SHIFT;
1394 	end_vaddr = mm->task_size;
1395 
1396 	/* watch out for wraparound */
1397 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1398 		start_vaddr = end_vaddr;
1399 
1400 	/*
1401 	 * The odds are that this will stop walking way
1402 	 * before end_vaddr, because the length of the
1403 	 * user buffer is tracked in "pm", and the walk
1404 	 * will stop when we hit the end of the buffer.
1405 	 */
1406 	ret = 0;
1407 	while (count && (start_vaddr < end_vaddr)) {
1408 		int len;
1409 		unsigned long end;
1410 
1411 		pm.pos = 0;
1412 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1413 		/* overflow ? */
1414 		if (end < start_vaddr || end > end_vaddr)
1415 			end = end_vaddr;
1416 		down_read(&mm->mmap_sem);
1417 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1418 		up_read(&mm->mmap_sem);
1419 		start_vaddr = end;
1420 
1421 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1422 		if (copy_to_user(buf, pm.buffer, len)) {
1423 			ret = -EFAULT;
1424 			goto out_free;
1425 		}
1426 		copied += len;
1427 		buf += len;
1428 		count -= len;
1429 	}
1430 	*ppos += copied;
1431 	if (!ret || ret == PM_END_OF_BUFFER)
1432 		ret = copied;
1433 
1434 out_free:
1435 	kfree(pm.buffer);
1436 out_mm:
1437 	mmput(mm);
1438 out:
1439 	return ret;
1440 }
1441 
1442 static int pagemap_open(struct inode *inode, struct file *file)
1443 {
1444 	struct mm_struct *mm;
1445 
1446 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1447 	if (IS_ERR(mm))
1448 		return PTR_ERR(mm);
1449 	file->private_data = mm;
1450 	return 0;
1451 }
1452 
1453 static int pagemap_release(struct inode *inode, struct file *file)
1454 {
1455 	struct mm_struct *mm = file->private_data;
1456 
1457 	if (mm)
1458 		mmdrop(mm);
1459 	return 0;
1460 }
1461 
1462 const struct file_operations proc_pagemap_operations = {
1463 	.llseek		= mem_lseek, /* borrow this */
1464 	.read		= pagemap_read,
1465 	.open		= pagemap_open,
1466 	.release	= pagemap_release,
1467 };
1468 #endif /* CONFIG_PROC_PAGE_MONITOR */
1469 
1470 #ifdef CONFIG_NUMA
1471 
1472 struct numa_maps {
1473 	unsigned long pages;
1474 	unsigned long anon;
1475 	unsigned long active;
1476 	unsigned long writeback;
1477 	unsigned long mapcount_max;
1478 	unsigned long dirty;
1479 	unsigned long swapcache;
1480 	unsigned long node[MAX_NUMNODES];
1481 };
1482 
1483 struct numa_maps_private {
1484 	struct proc_maps_private proc_maps;
1485 	struct numa_maps md;
1486 };
1487 
1488 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1489 			unsigned long nr_pages)
1490 {
1491 	int count = page_mapcount(page);
1492 
1493 	md->pages += nr_pages;
1494 	if (pte_dirty || PageDirty(page))
1495 		md->dirty += nr_pages;
1496 
1497 	if (PageSwapCache(page))
1498 		md->swapcache += nr_pages;
1499 
1500 	if (PageActive(page) || PageUnevictable(page))
1501 		md->active += nr_pages;
1502 
1503 	if (PageWriteback(page))
1504 		md->writeback += nr_pages;
1505 
1506 	if (PageAnon(page))
1507 		md->anon += nr_pages;
1508 
1509 	if (count > md->mapcount_max)
1510 		md->mapcount_max = count;
1511 
1512 	md->node[page_to_nid(page)] += nr_pages;
1513 }
1514 
1515 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1516 		unsigned long addr)
1517 {
1518 	struct page *page;
1519 	int nid;
1520 
1521 	if (!pte_present(pte))
1522 		return NULL;
1523 
1524 	page = vm_normal_page(vma, addr, pte);
1525 	if (!page)
1526 		return NULL;
1527 
1528 	if (PageReserved(page))
1529 		return NULL;
1530 
1531 	nid = page_to_nid(page);
1532 	if (!node_isset(nid, node_states[N_MEMORY]))
1533 		return NULL;
1534 
1535 	return page;
1536 }
1537 
1538 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1539 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1540 					      struct vm_area_struct *vma,
1541 					      unsigned long addr)
1542 {
1543 	struct page *page;
1544 	int nid;
1545 
1546 	if (!pmd_present(pmd))
1547 		return NULL;
1548 
1549 	page = vm_normal_page_pmd(vma, addr, pmd);
1550 	if (!page)
1551 		return NULL;
1552 
1553 	if (PageReserved(page))
1554 		return NULL;
1555 
1556 	nid = page_to_nid(page);
1557 	if (!node_isset(nid, node_states[N_MEMORY]))
1558 		return NULL;
1559 
1560 	return page;
1561 }
1562 #endif
1563 
1564 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1565 		unsigned long end, struct mm_walk *walk)
1566 {
1567 	struct numa_maps *md = walk->private;
1568 	struct vm_area_struct *vma = walk->vma;
1569 	spinlock_t *ptl;
1570 	pte_t *orig_pte;
1571 	pte_t *pte;
1572 
1573 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1574 	ptl = pmd_trans_huge_lock(pmd, vma);
1575 	if (ptl) {
1576 		struct page *page;
1577 
1578 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1579 		if (page)
1580 			gather_stats(page, md, pmd_dirty(*pmd),
1581 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1582 		spin_unlock(ptl);
1583 		return 0;
1584 	}
1585 
1586 	if (pmd_trans_unstable(pmd))
1587 		return 0;
1588 #endif
1589 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1590 	do {
1591 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1592 		if (!page)
1593 			continue;
1594 		gather_stats(page, md, pte_dirty(*pte), 1);
1595 
1596 	} while (pte++, addr += PAGE_SIZE, addr != end);
1597 	pte_unmap_unlock(orig_pte, ptl);
1598 	return 0;
1599 }
1600 #ifdef CONFIG_HUGETLB_PAGE
1601 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1602 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1603 {
1604 	pte_t huge_pte = huge_ptep_get(pte);
1605 	struct numa_maps *md;
1606 	struct page *page;
1607 
1608 	if (!pte_present(huge_pte))
1609 		return 0;
1610 
1611 	page = pte_page(huge_pte);
1612 	if (!page)
1613 		return 0;
1614 
1615 	md = walk->private;
1616 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1617 	return 0;
1618 }
1619 
1620 #else
1621 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1622 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1623 {
1624 	return 0;
1625 }
1626 #endif
1627 
1628 /*
1629  * Display pages allocated per node and memory policy via /proc.
1630  */
1631 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1632 {
1633 	struct numa_maps_private *numa_priv = m->private;
1634 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1635 	struct vm_area_struct *vma = v;
1636 	struct numa_maps *md = &numa_priv->md;
1637 	struct file *file = vma->vm_file;
1638 	struct mm_struct *mm = vma->vm_mm;
1639 	struct mm_walk walk = {
1640 		.hugetlb_entry = gather_hugetlb_stats,
1641 		.pmd_entry = gather_pte_stats,
1642 		.private = md,
1643 		.mm = mm,
1644 	};
1645 	struct mempolicy *pol;
1646 	char buffer[64];
1647 	int nid;
1648 
1649 	if (!mm)
1650 		return 0;
1651 
1652 	/* Ensure we start with an empty set of numa_maps statistics. */
1653 	memset(md, 0, sizeof(*md));
1654 
1655 	pol = __get_vma_policy(vma, vma->vm_start);
1656 	if (pol) {
1657 		mpol_to_str(buffer, sizeof(buffer), pol);
1658 		mpol_cond_put(pol);
1659 	} else {
1660 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1661 	}
1662 
1663 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1664 
1665 	if (file) {
1666 		seq_puts(m, " file=");
1667 		seq_file_path(m, file, "\n\t= ");
1668 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1669 		seq_puts(m, " heap");
1670 	} else if (is_stack(proc_priv, vma, is_pid)) {
1671 		seq_puts(m, " stack");
1672 	}
1673 
1674 	if (is_vm_hugetlb_page(vma))
1675 		seq_puts(m, " huge");
1676 
1677 	/* mmap_sem is held by m_start */
1678 	walk_page_vma(vma, &walk);
1679 
1680 	if (!md->pages)
1681 		goto out;
1682 
1683 	if (md->anon)
1684 		seq_printf(m, " anon=%lu", md->anon);
1685 
1686 	if (md->dirty)
1687 		seq_printf(m, " dirty=%lu", md->dirty);
1688 
1689 	if (md->pages != md->anon && md->pages != md->dirty)
1690 		seq_printf(m, " mapped=%lu", md->pages);
1691 
1692 	if (md->mapcount_max > 1)
1693 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1694 
1695 	if (md->swapcache)
1696 		seq_printf(m, " swapcache=%lu", md->swapcache);
1697 
1698 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1699 		seq_printf(m, " active=%lu", md->active);
1700 
1701 	if (md->writeback)
1702 		seq_printf(m, " writeback=%lu", md->writeback);
1703 
1704 	for_each_node_state(nid, N_MEMORY)
1705 		if (md->node[nid])
1706 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1707 
1708 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1709 out:
1710 	seq_putc(m, '\n');
1711 	m_cache_vma(m, vma);
1712 	return 0;
1713 }
1714 
1715 static int show_pid_numa_map(struct seq_file *m, void *v)
1716 {
1717 	return show_numa_map(m, v, 1);
1718 }
1719 
1720 static int show_tid_numa_map(struct seq_file *m, void *v)
1721 {
1722 	return show_numa_map(m, v, 0);
1723 }
1724 
1725 static const struct seq_operations proc_pid_numa_maps_op = {
1726 	.start  = m_start,
1727 	.next   = m_next,
1728 	.stop   = m_stop,
1729 	.show   = show_pid_numa_map,
1730 };
1731 
1732 static const struct seq_operations proc_tid_numa_maps_op = {
1733 	.start  = m_start,
1734 	.next   = m_next,
1735 	.stop   = m_stop,
1736 	.show   = show_tid_numa_map,
1737 };
1738 
1739 static int numa_maps_open(struct inode *inode, struct file *file,
1740 			  const struct seq_operations *ops)
1741 {
1742 	return proc_maps_open(inode, file, ops,
1743 				sizeof(struct numa_maps_private));
1744 }
1745 
1746 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1747 {
1748 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1749 }
1750 
1751 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1752 {
1753 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1754 }
1755 
1756 const struct file_operations proc_pid_numa_maps_operations = {
1757 	.open		= pid_numa_maps_open,
1758 	.read		= seq_read,
1759 	.llseek		= seq_lseek,
1760 	.release	= proc_map_release,
1761 };
1762 
1763 const struct file_operations proc_tid_numa_maps_operations = {
1764 	.open		= tid_numa_maps_open,
1765 	.read		= seq_read,
1766 	.llseek		= seq_lseek,
1767 	.release	= proc_map_release,
1768 };
1769 #endif /* CONFIG_NUMA */
1770