xref: /linux/fs/proc/task_mmu.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
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/sched/mm.h>
15 #include <linux/swapops.h>
16 #include <linux/mmu_notifier.h>
17 #include <linux/page_idle.h>
18 #include <linux/shmem_fs.h>
19 
20 #include <asm/elf.h>
21 #include <linux/uaccess.h>
22 #include <asm/tlbflush.h>
23 #include "internal.h"
24 
25 void task_mem(struct seq_file *m, struct mm_struct *mm)
26 {
27 	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
28 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
29 
30 	anon = get_mm_counter(mm, MM_ANONPAGES);
31 	file = get_mm_counter(mm, MM_FILEPAGES);
32 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
33 
34 	/*
35 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
36 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
37 	 * collector of these hiwater stats must therefore get total_vm
38 	 * and rss too, which will usually be the higher.  Barriers? not
39 	 * worth the effort, such snapshots can always be inconsistent.
40 	 */
41 	hiwater_vm = total_vm = mm->total_vm;
42 	if (hiwater_vm < mm->hiwater_vm)
43 		hiwater_vm = mm->hiwater_vm;
44 	hiwater_rss = total_rss = anon + file + shmem;
45 	if (hiwater_rss < mm->hiwater_rss)
46 		hiwater_rss = mm->hiwater_rss;
47 
48 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
49 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
50 	swap = get_mm_counter(mm, MM_SWAPENTS);
51 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
52 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
53 	seq_printf(m,
54 		"VmPeak:\t%8lu kB\n"
55 		"VmSize:\t%8lu kB\n"
56 		"VmLck:\t%8lu kB\n"
57 		"VmPin:\t%8lu kB\n"
58 		"VmHWM:\t%8lu kB\n"
59 		"VmRSS:\t%8lu kB\n"
60 		"RssAnon:\t%8lu kB\n"
61 		"RssFile:\t%8lu kB\n"
62 		"RssShmem:\t%8lu kB\n"
63 		"VmData:\t%8lu kB\n"
64 		"VmStk:\t%8lu kB\n"
65 		"VmExe:\t%8lu kB\n"
66 		"VmLib:\t%8lu kB\n"
67 		"VmPTE:\t%8lu kB\n"
68 		"VmPMD:\t%8lu kB\n"
69 		"VmSwap:\t%8lu kB\n",
70 		hiwater_vm << (PAGE_SHIFT-10),
71 		total_vm << (PAGE_SHIFT-10),
72 		mm->locked_vm << (PAGE_SHIFT-10),
73 		mm->pinned_vm << (PAGE_SHIFT-10),
74 		hiwater_rss << (PAGE_SHIFT-10),
75 		total_rss << (PAGE_SHIFT-10),
76 		anon << (PAGE_SHIFT-10),
77 		file << (PAGE_SHIFT-10),
78 		shmem << (PAGE_SHIFT-10),
79 		mm->data_vm << (PAGE_SHIFT-10),
80 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
81 		ptes >> 10,
82 		pmds >> 10,
83 		swap << (PAGE_SHIFT-10));
84 	hugetlb_report_usage(m, mm);
85 }
86 
87 unsigned long task_vsize(struct mm_struct *mm)
88 {
89 	return PAGE_SIZE * mm->total_vm;
90 }
91 
92 unsigned long task_statm(struct mm_struct *mm,
93 			 unsigned long *shared, unsigned long *text,
94 			 unsigned long *data, unsigned long *resident)
95 {
96 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
97 			get_mm_counter(mm, MM_SHMEMPAGES);
98 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
99 								>> PAGE_SHIFT;
100 	*data = mm->data_vm + mm->stack_vm;
101 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
102 	return mm->total_vm;
103 }
104 
105 #ifdef CONFIG_NUMA
106 /*
107  * Save get_task_policy() for show_numa_map().
108  */
109 static void hold_task_mempolicy(struct proc_maps_private *priv)
110 {
111 	struct task_struct *task = priv->task;
112 
113 	task_lock(task);
114 	priv->task_mempolicy = get_task_policy(task);
115 	mpol_get(priv->task_mempolicy);
116 	task_unlock(task);
117 }
118 static void release_task_mempolicy(struct proc_maps_private *priv)
119 {
120 	mpol_put(priv->task_mempolicy);
121 }
122 #else
123 static void hold_task_mempolicy(struct proc_maps_private *priv)
124 {
125 }
126 static void release_task_mempolicy(struct proc_maps_private *priv)
127 {
128 }
129 #endif
130 
131 static void vma_stop(struct proc_maps_private *priv)
132 {
133 	struct mm_struct *mm = priv->mm;
134 
135 	release_task_mempolicy(priv);
136 	up_read(&mm->mmap_sem);
137 	mmput(mm);
138 }
139 
140 static struct vm_area_struct *
141 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
142 {
143 	if (vma == priv->tail_vma)
144 		return NULL;
145 	return vma->vm_next ?: priv->tail_vma;
146 }
147 
148 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
149 {
150 	if (m->count < m->size)	/* vma is copied successfully */
151 		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
152 }
153 
154 static void *m_start(struct seq_file *m, loff_t *ppos)
155 {
156 	struct proc_maps_private *priv = m->private;
157 	unsigned long last_addr = m->version;
158 	struct mm_struct *mm;
159 	struct vm_area_struct *vma;
160 	unsigned int pos = *ppos;
161 
162 	/* See m_cache_vma(). Zero at the start or after lseek. */
163 	if (last_addr == -1UL)
164 		return NULL;
165 
166 	priv->task = get_proc_task(priv->inode);
167 	if (!priv->task)
168 		return ERR_PTR(-ESRCH);
169 
170 	mm = priv->mm;
171 	if (!mm || !mmget_not_zero(mm))
172 		return NULL;
173 
174 	down_read(&mm->mmap_sem);
175 	hold_task_mempolicy(priv);
176 	priv->tail_vma = get_gate_vma(mm);
177 
178 	if (last_addr) {
179 		vma = find_vma(mm, last_addr - 1);
180 		if (vma && vma->vm_start <= last_addr)
181 			vma = m_next_vma(priv, vma);
182 		if (vma)
183 			return vma;
184 	}
185 
186 	m->version = 0;
187 	if (pos < mm->map_count) {
188 		for (vma = mm->mmap; pos; pos--) {
189 			m->version = vma->vm_start;
190 			vma = vma->vm_next;
191 		}
192 		return vma;
193 	}
194 
195 	/* we do not bother to update m->version in this case */
196 	if (pos == mm->map_count && priv->tail_vma)
197 		return priv->tail_vma;
198 
199 	vma_stop(priv);
200 	return NULL;
201 }
202 
203 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
204 {
205 	struct proc_maps_private *priv = m->private;
206 	struct vm_area_struct *next;
207 
208 	(*pos)++;
209 	next = m_next_vma(priv, v);
210 	if (!next)
211 		vma_stop(priv);
212 	return next;
213 }
214 
215 static void m_stop(struct seq_file *m, void *v)
216 {
217 	struct proc_maps_private *priv = m->private;
218 
219 	if (!IS_ERR_OR_NULL(v))
220 		vma_stop(priv);
221 	if (priv->task) {
222 		put_task_struct(priv->task);
223 		priv->task = NULL;
224 	}
225 }
226 
227 static int proc_maps_open(struct inode *inode, struct file *file,
228 			const struct seq_operations *ops, int psize)
229 {
230 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
231 
232 	if (!priv)
233 		return -ENOMEM;
234 
235 	priv->inode = inode;
236 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
237 	if (IS_ERR(priv->mm)) {
238 		int err = PTR_ERR(priv->mm);
239 
240 		seq_release_private(inode, file);
241 		return err;
242 	}
243 
244 	return 0;
245 }
246 
247 static int proc_map_release(struct inode *inode, struct file *file)
248 {
249 	struct seq_file *seq = file->private_data;
250 	struct proc_maps_private *priv = seq->private;
251 
252 	if (priv->mm)
253 		mmdrop(priv->mm);
254 
255 	return seq_release_private(inode, file);
256 }
257 
258 static int do_maps_open(struct inode *inode, struct file *file,
259 			const struct seq_operations *ops)
260 {
261 	return proc_maps_open(inode, file, ops,
262 				sizeof(struct proc_maps_private));
263 }
264 
265 /*
266  * Indicate if the VMA is a stack for the given task; for
267  * /proc/PID/maps that is the stack of the main task.
268  */
269 static int is_stack(struct proc_maps_private *priv,
270 		    struct vm_area_struct *vma)
271 {
272 	/*
273 	 * We make no effort to guess what a given thread considers to be
274 	 * its "stack".  It's not even well-defined for programs written
275 	 * languages like Go.
276 	 */
277 	return vma->vm_start <= vma->vm_mm->start_stack &&
278 		vma->vm_end >= vma->vm_mm->start_stack;
279 }
280 
281 static void
282 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
283 {
284 	struct mm_struct *mm = vma->vm_mm;
285 	struct file *file = vma->vm_file;
286 	struct proc_maps_private *priv = m->private;
287 	vm_flags_t flags = vma->vm_flags;
288 	unsigned long ino = 0;
289 	unsigned long long pgoff = 0;
290 	unsigned long start, end;
291 	dev_t dev = 0;
292 	const char *name = NULL;
293 
294 	if (file) {
295 		struct inode *inode = file_inode(vma->vm_file);
296 		dev = inode->i_sb->s_dev;
297 		ino = inode->i_ino;
298 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
299 	}
300 
301 	start = vma->vm_start;
302 	end = vma->vm_end;
303 
304 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
305 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
306 			start,
307 			end,
308 			flags & VM_READ ? 'r' : '-',
309 			flags & VM_WRITE ? 'w' : '-',
310 			flags & VM_EXEC ? 'x' : '-',
311 			flags & VM_MAYSHARE ? 's' : 'p',
312 			pgoff,
313 			MAJOR(dev), MINOR(dev), ino);
314 
315 	/*
316 	 * Print the dentry name for named mappings, and a
317 	 * special [heap] marker for the heap:
318 	 */
319 	if (file) {
320 		seq_pad(m, ' ');
321 		seq_file_path(m, file, "\n");
322 		goto done;
323 	}
324 
325 	if (vma->vm_ops && vma->vm_ops->name) {
326 		name = vma->vm_ops->name(vma);
327 		if (name)
328 			goto done;
329 	}
330 
331 	name = arch_vma_name(vma);
332 	if (!name) {
333 		if (!mm) {
334 			name = "[vdso]";
335 			goto done;
336 		}
337 
338 		if (vma->vm_start <= mm->brk &&
339 		    vma->vm_end >= mm->start_brk) {
340 			name = "[heap]";
341 			goto done;
342 		}
343 
344 		if (is_stack(priv, vma))
345 			name = "[stack]";
346 	}
347 
348 done:
349 	if (name) {
350 		seq_pad(m, ' ');
351 		seq_puts(m, name);
352 	}
353 	seq_putc(m, '\n');
354 }
355 
356 static int show_map(struct seq_file *m, void *v, int is_pid)
357 {
358 	show_map_vma(m, v, is_pid);
359 	m_cache_vma(m, v);
360 	return 0;
361 }
362 
363 static int show_pid_map(struct seq_file *m, void *v)
364 {
365 	return show_map(m, v, 1);
366 }
367 
368 static int show_tid_map(struct seq_file *m, void *v)
369 {
370 	return show_map(m, v, 0);
371 }
372 
373 static const struct seq_operations proc_pid_maps_op = {
374 	.start	= m_start,
375 	.next	= m_next,
376 	.stop	= m_stop,
377 	.show	= show_pid_map
378 };
379 
380 static const struct seq_operations proc_tid_maps_op = {
381 	.start	= m_start,
382 	.next	= m_next,
383 	.stop	= m_stop,
384 	.show	= show_tid_map
385 };
386 
387 static int pid_maps_open(struct inode *inode, struct file *file)
388 {
389 	return do_maps_open(inode, file, &proc_pid_maps_op);
390 }
391 
392 static int tid_maps_open(struct inode *inode, struct file *file)
393 {
394 	return do_maps_open(inode, file, &proc_tid_maps_op);
395 }
396 
397 const struct file_operations proc_pid_maps_operations = {
398 	.open		= pid_maps_open,
399 	.read		= seq_read,
400 	.llseek		= seq_lseek,
401 	.release	= proc_map_release,
402 };
403 
404 const struct file_operations proc_tid_maps_operations = {
405 	.open		= tid_maps_open,
406 	.read		= seq_read,
407 	.llseek		= seq_lseek,
408 	.release	= proc_map_release,
409 };
410 
411 /*
412  * Proportional Set Size(PSS): my share of RSS.
413  *
414  * PSS of a process is the count of pages it has in memory, where each
415  * page is divided by the number of processes sharing it.  So if a
416  * process has 1000 pages all to itself, and 1000 shared with one other
417  * process, its PSS will be 1500.
418  *
419  * To keep (accumulated) division errors low, we adopt a 64bit
420  * fixed-point pss counter to minimize division errors. So (pss >>
421  * PSS_SHIFT) would be the real byte count.
422  *
423  * A shift of 12 before division means (assuming 4K page size):
424  * 	- 1M 3-user-pages add up to 8KB errors;
425  * 	- supports mapcount up to 2^24, or 16M;
426  * 	- supports PSS up to 2^52 bytes, or 4PB.
427  */
428 #define PSS_SHIFT 12
429 
430 #ifdef CONFIG_PROC_PAGE_MONITOR
431 struct mem_size_stats {
432 	unsigned long resident;
433 	unsigned long shared_clean;
434 	unsigned long shared_dirty;
435 	unsigned long private_clean;
436 	unsigned long private_dirty;
437 	unsigned long referenced;
438 	unsigned long anonymous;
439 	unsigned long lazyfree;
440 	unsigned long anonymous_thp;
441 	unsigned long shmem_thp;
442 	unsigned long swap;
443 	unsigned long shared_hugetlb;
444 	unsigned long private_hugetlb;
445 	u64 pss;
446 	u64 swap_pss;
447 	bool check_shmem_swap;
448 };
449 
450 static void smaps_account(struct mem_size_stats *mss, struct page *page,
451 		bool compound, bool young, bool dirty)
452 {
453 	int i, nr = compound ? 1 << compound_order(page) : 1;
454 	unsigned long size = nr * PAGE_SIZE;
455 
456 	if (PageAnon(page)) {
457 		mss->anonymous += size;
458 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
459 			mss->lazyfree += size;
460 	}
461 
462 	mss->resident += size;
463 	/* Accumulate the size in pages that have been accessed. */
464 	if (young || page_is_young(page) || PageReferenced(page))
465 		mss->referenced += size;
466 
467 	/*
468 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
469 	 * If any subpage of the compound page mapped with PTE it would elevate
470 	 * page_count().
471 	 */
472 	if (page_count(page) == 1) {
473 		if (dirty || PageDirty(page))
474 			mss->private_dirty += size;
475 		else
476 			mss->private_clean += size;
477 		mss->pss += (u64)size << PSS_SHIFT;
478 		return;
479 	}
480 
481 	for (i = 0; i < nr; i++, page++) {
482 		int mapcount = page_mapcount(page);
483 
484 		if (mapcount >= 2) {
485 			if (dirty || PageDirty(page))
486 				mss->shared_dirty += PAGE_SIZE;
487 			else
488 				mss->shared_clean += PAGE_SIZE;
489 			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
490 		} else {
491 			if (dirty || PageDirty(page))
492 				mss->private_dirty += PAGE_SIZE;
493 			else
494 				mss->private_clean += PAGE_SIZE;
495 			mss->pss += PAGE_SIZE << PSS_SHIFT;
496 		}
497 	}
498 }
499 
500 #ifdef CONFIG_SHMEM
501 static int smaps_pte_hole(unsigned long addr, unsigned long end,
502 		struct mm_walk *walk)
503 {
504 	struct mem_size_stats *mss = walk->private;
505 
506 	mss->swap += shmem_partial_swap_usage(
507 			walk->vma->vm_file->f_mapping, addr, end);
508 
509 	return 0;
510 }
511 #endif
512 
513 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
514 		struct mm_walk *walk)
515 {
516 	struct mem_size_stats *mss = walk->private;
517 	struct vm_area_struct *vma = walk->vma;
518 	struct page *page = NULL;
519 
520 	if (pte_present(*pte)) {
521 		page = vm_normal_page(vma, addr, *pte);
522 	} else if (is_swap_pte(*pte)) {
523 		swp_entry_t swpent = pte_to_swp_entry(*pte);
524 
525 		if (!non_swap_entry(swpent)) {
526 			int mapcount;
527 
528 			mss->swap += PAGE_SIZE;
529 			mapcount = swp_swapcount(swpent);
530 			if (mapcount >= 2) {
531 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
532 
533 				do_div(pss_delta, mapcount);
534 				mss->swap_pss += pss_delta;
535 			} else {
536 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
537 			}
538 		} else if (is_migration_entry(swpent))
539 			page = migration_entry_to_page(swpent);
540 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
541 							&& pte_none(*pte))) {
542 		page = find_get_entry(vma->vm_file->f_mapping,
543 						linear_page_index(vma, addr));
544 		if (!page)
545 			return;
546 
547 		if (radix_tree_exceptional_entry(page))
548 			mss->swap += PAGE_SIZE;
549 		else
550 			put_page(page);
551 
552 		return;
553 	}
554 
555 	if (!page)
556 		return;
557 
558 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
559 }
560 
561 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
562 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
563 		struct mm_walk *walk)
564 {
565 	struct mem_size_stats *mss = walk->private;
566 	struct vm_area_struct *vma = walk->vma;
567 	struct page *page;
568 
569 	/* FOLL_DUMP will return -EFAULT on huge zero page */
570 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
571 	if (IS_ERR_OR_NULL(page))
572 		return;
573 	if (PageAnon(page))
574 		mss->anonymous_thp += HPAGE_PMD_SIZE;
575 	else if (PageSwapBacked(page))
576 		mss->shmem_thp += HPAGE_PMD_SIZE;
577 	else if (is_zone_device_page(page))
578 		/* pass */;
579 	else
580 		VM_BUG_ON_PAGE(1, page);
581 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
582 }
583 #else
584 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
585 		struct mm_walk *walk)
586 {
587 }
588 #endif
589 
590 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
591 			   struct mm_walk *walk)
592 {
593 	struct vm_area_struct *vma = walk->vma;
594 	pte_t *pte;
595 	spinlock_t *ptl;
596 
597 	ptl = pmd_trans_huge_lock(pmd, vma);
598 	if (ptl) {
599 		smaps_pmd_entry(pmd, addr, walk);
600 		spin_unlock(ptl);
601 		return 0;
602 	}
603 
604 	if (pmd_trans_unstable(pmd))
605 		return 0;
606 	/*
607 	 * The mmap_sem held all the way back in m_start() is what
608 	 * keeps khugepaged out of here and from collapsing things
609 	 * in here.
610 	 */
611 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
612 	for (; addr != end; pte++, addr += PAGE_SIZE)
613 		smaps_pte_entry(pte, addr, walk);
614 	pte_unmap_unlock(pte - 1, ptl);
615 	cond_resched();
616 	return 0;
617 }
618 
619 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
620 {
621 	/*
622 	 * Don't forget to update Documentation/ on changes.
623 	 */
624 	static const char mnemonics[BITS_PER_LONG][2] = {
625 		/*
626 		 * In case if we meet a flag we don't know about.
627 		 */
628 		[0 ... (BITS_PER_LONG-1)] = "??",
629 
630 		[ilog2(VM_READ)]	= "rd",
631 		[ilog2(VM_WRITE)]	= "wr",
632 		[ilog2(VM_EXEC)]	= "ex",
633 		[ilog2(VM_SHARED)]	= "sh",
634 		[ilog2(VM_MAYREAD)]	= "mr",
635 		[ilog2(VM_MAYWRITE)]	= "mw",
636 		[ilog2(VM_MAYEXEC)]	= "me",
637 		[ilog2(VM_MAYSHARE)]	= "ms",
638 		[ilog2(VM_GROWSDOWN)]	= "gd",
639 		[ilog2(VM_PFNMAP)]	= "pf",
640 		[ilog2(VM_DENYWRITE)]	= "dw",
641 #ifdef CONFIG_X86_INTEL_MPX
642 		[ilog2(VM_MPX)]		= "mp",
643 #endif
644 		[ilog2(VM_LOCKED)]	= "lo",
645 		[ilog2(VM_IO)]		= "io",
646 		[ilog2(VM_SEQ_READ)]	= "sr",
647 		[ilog2(VM_RAND_READ)]	= "rr",
648 		[ilog2(VM_DONTCOPY)]	= "dc",
649 		[ilog2(VM_DONTEXPAND)]	= "de",
650 		[ilog2(VM_ACCOUNT)]	= "ac",
651 		[ilog2(VM_NORESERVE)]	= "nr",
652 		[ilog2(VM_HUGETLB)]	= "ht",
653 		[ilog2(VM_ARCH_1)]	= "ar",
654 		[ilog2(VM_DONTDUMP)]	= "dd",
655 #ifdef CONFIG_MEM_SOFT_DIRTY
656 		[ilog2(VM_SOFTDIRTY)]	= "sd",
657 #endif
658 		[ilog2(VM_MIXEDMAP)]	= "mm",
659 		[ilog2(VM_HUGEPAGE)]	= "hg",
660 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
661 		[ilog2(VM_MERGEABLE)]	= "mg",
662 		[ilog2(VM_UFFD_MISSING)]= "um",
663 		[ilog2(VM_UFFD_WP)]	= "uw",
664 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
665 		/* These come out via ProtectionKey: */
666 		[ilog2(VM_PKEY_BIT0)]	= "",
667 		[ilog2(VM_PKEY_BIT1)]	= "",
668 		[ilog2(VM_PKEY_BIT2)]	= "",
669 		[ilog2(VM_PKEY_BIT3)]	= "",
670 #endif
671 	};
672 	size_t i;
673 
674 	seq_puts(m, "VmFlags: ");
675 	for (i = 0; i < BITS_PER_LONG; i++) {
676 		if (!mnemonics[i][0])
677 			continue;
678 		if (vma->vm_flags & (1UL << i)) {
679 			seq_printf(m, "%c%c ",
680 				   mnemonics[i][0], mnemonics[i][1]);
681 		}
682 	}
683 	seq_putc(m, '\n');
684 }
685 
686 #ifdef CONFIG_HUGETLB_PAGE
687 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
688 				 unsigned long addr, unsigned long end,
689 				 struct mm_walk *walk)
690 {
691 	struct mem_size_stats *mss = walk->private;
692 	struct vm_area_struct *vma = walk->vma;
693 	struct page *page = NULL;
694 
695 	if (pte_present(*pte)) {
696 		page = vm_normal_page(vma, addr, *pte);
697 	} else if (is_swap_pte(*pte)) {
698 		swp_entry_t swpent = pte_to_swp_entry(*pte);
699 
700 		if (is_migration_entry(swpent))
701 			page = migration_entry_to_page(swpent);
702 	}
703 	if (page) {
704 		int mapcount = page_mapcount(page);
705 
706 		if (mapcount >= 2)
707 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
708 		else
709 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
710 	}
711 	return 0;
712 }
713 #endif /* HUGETLB_PAGE */
714 
715 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
716 {
717 }
718 
719 static int show_smap(struct seq_file *m, void *v, int is_pid)
720 {
721 	struct vm_area_struct *vma = v;
722 	struct mem_size_stats mss;
723 	struct mm_walk smaps_walk = {
724 		.pmd_entry = smaps_pte_range,
725 #ifdef CONFIG_HUGETLB_PAGE
726 		.hugetlb_entry = smaps_hugetlb_range,
727 #endif
728 		.mm = vma->vm_mm,
729 		.private = &mss,
730 	};
731 
732 	memset(&mss, 0, sizeof mss);
733 
734 #ifdef CONFIG_SHMEM
735 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
736 		/*
737 		 * For shared or readonly shmem mappings we know that all
738 		 * swapped out pages belong to the shmem object, and we can
739 		 * obtain the swap value much more efficiently. For private
740 		 * writable mappings, we might have COW pages that are
741 		 * not affected by the parent swapped out pages of the shmem
742 		 * object, so we have to distinguish them during the page walk.
743 		 * Unless we know that the shmem object (or the part mapped by
744 		 * our VMA) has no swapped out pages at all.
745 		 */
746 		unsigned long shmem_swapped = shmem_swap_usage(vma);
747 
748 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
749 					!(vma->vm_flags & VM_WRITE)) {
750 			mss.swap = shmem_swapped;
751 		} else {
752 			mss.check_shmem_swap = true;
753 			smaps_walk.pte_hole = smaps_pte_hole;
754 		}
755 	}
756 #endif
757 
758 	/* mmap_sem is held in m_start */
759 	walk_page_vma(vma, &smaps_walk);
760 
761 	show_map_vma(m, vma, is_pid);
762 
763 	seq_printf(m,
764 		   "Size:           %8lu kB\n"
765 		   "Rss:            %8lu kB\n"
766 		   "Pss:            %8lu kB\n"
767 		   "Shared_Clean:   %8lu kB\n"
768 		   "Shared_Dirty:   %8lu kB\n"
769 		   "Private_Clean:  %8lu kB\n"
770 		   "Private_Dirty:  %8lu kB\n"
771 		   "Referenced:     %8lu kB\n"
772 		   "Anonymous:      %8lu kB\n"
773 		   "LazyFree:       %8lu kB\n"
774 		   "AnonHugePages:  %8lu kB\n"
775 		   "ShmemPmdMapped: %8lu kB\n"
776 		   "Shared_Hugetlb: %8lu kB\n"
777 		   "Private_Hugetlb: %7lu kB\n"
778 		   "Swap:           %8lu kB\n"
779 		   "SwapPss:        %8lu kB\n"
780 		   "KernelPageSize: %8lu kB\n"
781 		   "MMUPageSize:    %8lu kB\n"
782 		   "Locked:         %8lu kB\n",
783 		   (vma->vm_end - vma->vm_start) >> 10,
784 		   mss.resident >> 10,
785 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
786 		   mss.shared_clean  >> 10,
787 		   mss.shared_dirty  >> 10,
788 		   mss.private_clean >> 10,
789 		   mss.private_dirty >> 10,
790 		   mss.referenced >> 10,
791 		   mss.anonymous >> 10,
792 		   mss.lazyfree >> 10,
793 		   mss.anonymous_thp >> 10,
794 		   mss.shmem_thp >> 10,
795 		   mss.shared_hugetlb >> 10,
796 		   mss.private_hugetlb >> 10,
797 		   mss.swap >> 10,
798 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
799 		   vma_kernel_pagesize(vma) >> 10,
800 		   vma_mmu_pagesize(vma) >> 10,
801 		   (vma->vm_flags & VM_LOCKED) ?
802 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
803 
804 	arch_show_smap(m, vma);
805 	show_smap_vma_flags(m, vma);
806 	m_cache_vma(m, vma);
807 	return 0;
808 }
809 
810 static int show_pid_smap(struct seq_file *m, void *v)
811 {
812 	return show_smap(m, v, 1);
813 }
814 
815 static int show_tid_smap(struct seq_file *m, void *v)
816 {
817 	return show_smap(m, v, 0);
818 }
819 
820 static const struct seq_operations proc_pid_smaps_op = {
821 	.start	= m_start,
822 	.next	= m_next,
823 	.stop	= m_stop,
824 	.show	= show_pid_smap
825 };
826 
827 static const struct seq_operations proc_tid_smaps_op = {
828 	.start	= m_start,
829 	.next	= m_next,
830 	.stop	= m_stop,
831 	.show	= show_tid_smap
832 };
833 
834 static int pid_smaps_open(struct inode *inode, struct file *file)
835 {
836 	return do_maps_open(inode, file, &proc_pid_smaps_op);
837 }
838 
839 static int tid_smaps_open(struct inode *inode, struct file *file)
840 {
841 	return do_maps_open(inode, file, &proc_tid_smaps_op);
842 }
843 
844 const struct file_operations proc_pid_smaps_operations = {
845 	.open		= pid_smaps_open,
846 	.read		= seq_read,
847 	.llseek		= seq_lseek,
848 	.release	= proc_map_release,
849 };
850 
851 const struct file_operations proc_tid_smaps_operations = {
852 	.open		= tid_smaps_open,
853 	.read		= seq_read,
854 	.llseek		= seq_lseek,
855 	.release	= proc_map_release,
856 };
857 
858 enum clear_refs_types {
859 	CLEAR_REFS_ALL = 1,
860 	CLEAR_REFS_ANON,
861 	CLEAR_REFS_MAPPED,
862 	CLEAR_REFS_SOFT_DIRTY,
863 	CLEAR_REFS_MM_HIWATER_RSS,
864 	CLEAR_REFS_LAST,
865 };
866 
867 struct clear_refs_private {
868 	enum clear_refs_types type;
869 };
870 
871 #ifdef CONFIG_MEM_SOFT_DIRTY
872 static inline void clear_soft_dirty(struct vm_area_struct *vma,
873 		unsigned long addr, pte_t *pte)
874 {
875 	/*
876 	 * The soft-dirty tracker uses #PF-s to catch writes
877 	 * to pages, so write-protect the pte as well. See the
878 	 * Documentation/vm/soft-dirty.txt for full description
879 	 * of how soft-dirty works.
880 	 */
881 	pte_t ptent = *pte;
882 
883 	if (pte_present(ptent)) {
884 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
885 		ptent = pte_wrprotect(ptent);
886 		ptent = pte_clear_soft_dirty(ptent);
887 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
888 	} else if (is_swap_pte(ptent)) {
889 		ptent = pte_swp_clear_soft_dirty(ptent);
890 		set_pte_at(vma->vm_mm, addr, pte, ptent);
891 	}
892 }
893 #else
894 static inline void clear_soft_dirty(struct vm_area_struct *vma,
895 		unsigned long addr, pte_t *pte)
896 {
897 }
898 #endif
899 
900 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
901 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
902 		unsigned long addr, pmd_t *pmdp)
903 {
904 	pmd_t pmd = *pmdp;
905 
906 	/* See comment in change_huge_pmd() */
907 	pmdp_invalidate(vma, addr, pmdp);
908 	if (pmd_dirty(*pmdp))
909 		pmd = pmd_mkdirty(pmd);
910 	if (pmd_young(*pmdp))
911 		pmd = pmd_mkyoung(pmd);
912 
913 	pmd = pmd_wrprotect(pmd);
914 	pmd = pmd_clear_soft_dirty(pmd);
915 
916 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
917 }
918 #else
919 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
920 		unsigned long addr, pmd_t *pmdp)
921 {
922 }
923 #endif
924 
925 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
926 				unsigned long end, struct mm_walk *walk)
927 {
928 	struct clear_refs_private *cp = walk->private;
929 	struct vm_area_struct *vma = walk->vma;
930 	pte_t *pte, ptent;
931 	spinlock_t *ptl;
932 	struct page *page;
933 
934 	ptl = pmd_trans_huge_lock(pmd, vma);
935 	if (ptl) {
936 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
937 			clear_soft_dirty_pmd(vma, addr, pmd);
938 			goto out;
939 		}
940 
941 		page = pmd_page(*pmd);
942 
943 		/* Clear accessed and referenced bits. */
944 		pmdp_test_and_clear_young(vma, addr, pmd);
945 		test_and_clear_page_young(page);
946 		ClearPageReferenced(page);
947 out:
948 		spin_unlock(ptl);
949 		return 0;
950 	}
951 
952 	if (pmd_trans_unstable(pmd))
953 		return 0;
954 
955 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
956 	for (; addr != end; pte++, addr += PAGE_SIZE) {
957 		ptent = *pte;
958 
959 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
960 			clear_soft_dirty(vma, addr, pte);
961 			continue;
962 		}
963 
964 		if (!pte_present(ptent))
965 			continue;
966 
967 		page = vm_normal_page(vma, addr, ptent);
968 		if (!page)
969 			continue;
970 
971 		/* Clear accessed and referenced bits. */
972 		ptep_test_and_clear_young(vma, addr, pte);
973 		test_and_clear_page_young(page);
974 		ClearPageReferenced(page);
975 	}
976 	pte_unmap_unlock(pte - 1, ptl);
977 	cond_resched();
978 	return 0;
979 }
980 
981 static int clear_refs_test_walk(unsigned long start, unsigned long end,
982 				struct mm_walk *walk)
983 {
984 	struct clear_refs_private *cp = walk->private;
985 	struct vm_area_struct *vma = walk->vma;
986 
987 	if (vma->vm_flags & VM_PFNMAP)
988 		return 1;
989 
990 	/*
991 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
992 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
993 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
994 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
995 	 */
996 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
997 		return 1;
998 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
999 		return 1;
1000 	return 0;
1001 }
1002 
1003 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1004 				size_t count, loff_t *ppos)
1005 {
1006 	struct task_struct *task;
1007 	char buffer[PROC_NUMBUF];
1008 	struct mm_struct *mm;
1009 	struct vm_area_struct *vma;
1010 	enum clear_refs_types type;
1011 	int itype;
1012 	int rv;
1013 
1014 	memset(buffer, 0, sizeof(buffer));
1015 	if (count > sizeof(buffer) - 1)
1016 		count = sizeof(buffer) - 1;
1017 	if (copy_from_user(buffer, buf, count))
1018 		return -EFAULT;
1019 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1020 	if (rv < 0)
1021 		return rv;
1022 	type = (enum clear_refs_types)itype;
1023 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1024 		return -EINVAL;
1025 
1026 	task = get_proc_task(file_inode(file));
1027 	if (!task)
1028 		return -ESRCH;
1029 	mm = get_task_mm(task);
1030 	if (mm) {
1031 		struct clear_refs_private cp = {
1032 			.type = type,
1033 		};
1034 		struct mm_walk clear_refs_walk = {
1035 			.pmd_entry = clear_refs_pte_range,
1036 			.test_walk = clear_refs_test_walk,
1037 			.mm = mm,
1038 			.private = &cp,
1039 		};
1040 
1041 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1042 			if (down_write_killable(&mm->mmap_sem)) {
1043 				count = -EINTR;
1044 				goto out_mm;
1045 			}
1046 
1047 			/*
1048 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1049 			 * resident set size to this mm's current rss value.
1050 			 */
1051 			reset_mm_hiwater_rss(mm);
1052 			up_write(&mm->mmap_sem);
1053 			goto out_mm;
1054 		}
1055 
1056 		down_read(&mm->mmap_sem);
1057 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1058 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1059 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1060 					continue;
1061 				up_read(&mm->mmap_sem);
1062 				if (down_write_killable(&mm->mmap_sem)) {
1063 					count = -EINTR;
1064 					goto out_mm;
1065 				}
1066 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1067 					vma->vm_flags &= ~VM_SOFTDIRTY;
1068 					vma_set_page_prot(vma);
1069 				}
1070 				downgrade_write(&mm->mmap_sem);
1071 				break;
1072 			}
1073 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1074 		}
1075 		walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1076 		if (type == CLEAR_REFS_SOFT_DIRTY)
1077 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1078 		flush_tlb_mm(mm);
1079 		up_read(&mm->mmap_sem);
1080 out_mm:
1081 		mmput(mm);
1082 	}
1083 	put_task_struct(task);
1084 
1085 	return count;
1086 }
1087 
1088 const struct file_operations proc_clear_refs_operations = {
1089 	.write		= clear_refs_write,
1090 	.llseek		= noop_llseek,
1091 };
1092 
1093 typedef struct {
1094 	u64 pme;
1095 } pagemap_entry_t;
1096 
1097 struct pagemapread {
1098 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1099 	pagemap_entry_t *buffer;
1100 	bool show_pfn;
1101 };
1102 
1103 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1104 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1105 
1106 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1107 #define PM_PFRAME_BITS		55
1108 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1109 #define PM_SOFT_DIRTY		BIT_ULL(55)
1110 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1111 #define PM_FILE			BIT_ULL(61)
1112 #define PM_SWAP			BIT_ULL(62)
1113 #define PM_PRESENT		BIT_ULL(63)
1114 
1115 #define PM_END_OF_BUFFER    1
1116 
1117 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1118 {
1119 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1120 }
1121 
1122 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1123 			  struct pagemapread *pm)
1124 {
1125 	pm->buffer[pm->pos++] = *pme;
1126 	if (pm->pos >= pm->len)
1127 		return PM_END_OF_BUFFER;
1128 	return 0;
1129 }
1130 
1131 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1132 				struct mm_walk *walk)
1133 {
1134 	struct pagemapread *pm = walk->private;
1135 	unsigned long addr = start;
1136 	int err = 0;
1137 
1138 	while (addr < end) {
1139 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1140 		pagemap_entry_t pme = make_pme(0, 0);
1141 		/* End of address space hole, which we mark as non-present. */
1142 		unsigned long hole_end;
1143 
1144 		if (vma)
1145 			hole_end = min(end, vma->vm_start);
1146 		else
1147 			hole_end = end;
1148 
1149 		for (; addr < hole_end; addr += PAGE_SIZE) {
1150 			err = add_to_pagemap(addr, &pme, pm);
1151 			if (err)
1152 				goto out;
1153 		}
1154 
1155 		if (!vma)
1156 			break;
1157 
1158 		/* Addresses in the VMA. */
1159 		if (vma->vm_flags & VM_SOFTDIRTY)
1160 			pme = make_pme(0, PM_SOFT_DIRTY);
1161 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1162 			err = add_to_pagemap(addr, &pme, pm);
1163 			if (err)
1164 				goto out;
1165 		}
1166 	}
1167 out:
1168 	return err;
1169 }
1170 
1171 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1172 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1173 {
1174 	u64 frame = 0, flags = 0;
1175 	struct page *page = NULL;
1176 
1177 	if (pte_present(pte)) {
1178 		if (pm->show_pfn)
1179 			frame = pte_pfn(pte);
1180 		flags |= PM_PRESENT;
1181 		page = vm_normal_page(vma, addr, pte);
1182 		if (pte_soft_dirty(pte))
1183 			flags |= PM_SOFT_DIRTY;
1184 	} else if (is_swap_pte(pte)) {
1185 		swp_entry_t entry;
1186 		if (pte_swp_soft_dirty(pte))
1187 			flags |= PM_SOFT_DIRTY;
1188 		entry = pte_to_swp_entry(pte);
1189 		frame = swp_type(entry) |
1190 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1191 		flags |= PM_SWAP;
1192 		if (is_migration_entry(entry))
1193 			page = migration_entry_to_page(entry);
1194 	}
1195 
1196 	if (page && !PageAnon(page))
1197 		flags |= PM_FILE;
1198 	if (page && page_mapcount(page) == 1)
1199 		flags |= PM_MMAP_EXCLUSIVE;
1200 	if (vma->vm_flags & VM_SOFTDIRTY)
1201 		flags |= PM_SOFT_DIRTY;
1202 
1203 	return make_pme(frame, flags);
1204 }
1205 
1206 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1207 			     struct mm_walk *walk)
1208 {
1209 	struct vm_area_struct *vma = walk->vma;
1210 	struct pagemapread *pm = walk->private;
1211 	spinlock_t *ptl;
1212 	pte_t *pte, *orig_pte;
1213 	int err = 0;
1214 
1215 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1216 	ptl = pmd_trans_huge_lock(pmdp, vma);
1217 	if (ptl) {
1218 		u64 flags = 0, frame = 0;
1219 		pmd_t pmd = *pmdp;
1220 
1221 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1222 			flags |= PM_SOFT_DIRTY;
1223 
1224 		/*
1225 		 * Currently pmd for thp is always present because thp
1226 		 * can not be swapped-out, migrated, or HWPOISONed
1227 		 * (split in such cases instead.)
1228 		 * This if-check is just to prepare for future implementation.
1229 		 */
1230 		if (pmd_present(pmd)) {
1231 			struct page *page = pmd_page(pmd);
1232 
1233 			if (page_mapcount(page) == 1)
1234 				flags |= PM_MMAP_EXCLUSIVE;
1235 
1236 			flags |= PM_PRESENT;
1237 			if (pm->show_pfn)
1238 				frame = pmd_pfn(pmd) +
1239 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1240 		}
1241 
1242 		for (; addr != end; addr += PAGE_SIZE) {
1243 			pagemap_entry_t pme = make_pme(frame, flags);
1244 
1245 			err = add_to_pagemap(addr, &pme, pm);
1246 			if (err)
1247 				break;
1248 			if (pm->show_pfn && (flags & PM_PRESENT))
1249 				frame++;
1250 		}
1251 		spin_unlock(ptl);
1252 		return err;
1253 	}
1254 
1255 	if (pmd_trans_unstable(pmdp))
1256 		return 0;
1257 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1258 
1259 	/*
1260 	 * We can assume that @vma always points to a valid one and @end never
1261 	 * goes beyond vma->vm_end.
1262 	 */
1263 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1264 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1265 		pagemap_entry_t pme;
1266 
1267 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1268 		err = add_to_pagemap(addr, &pme, pm);
1269 		if (err)
1270 			break;
1271 	}
1272 	pte_unmap_unlock(orig_pte, ptl);
1273 
1274 	cond_resched();
1275 
1276 	return err;
1277 }
1278 
1279 #ifdef CONFIG_HUGETLB_PAGE
1280 /* This function walks within one hugetlb entry in the single call */
1281 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1282 				 unsigned long addr, unsigned long end,
1283 				 struct mm_walk *walk)
1284 {
1285 	struct pagemapread *pm = walk->private;
1286 	struct vm_area_struct *vma = walk->vma;
1287 	u64 flags = 0, frame = 0;
1288 	int err = 0;
1289 	pte_t pte;
1290 
1291 	if (vma->vm_flags & VM_SOFTDIRTY)
1292 		flags |= PM_SOFT_DIRTY;
1293 
1294 	pte = huge_ptep_get(ptep);
1295 	if (pte_present(pte)) {
1296 		struct page *page = pte_page(pte);
1297 
1298 		if (!PageAnon(page))
1299 			flags |= PM_FILE;
1300 
1301 		if (page_mapcount(page) == 1)
1302 			flags |= PM_MMAP_EXCLUSIVE;
1303 
1304 		flags |= PM_PRESENT;
1305 		if (pm->show_pfn)
1306 			frame = pte_pfn(pte) +
1307 				((addr & ~hmask) >> PAGE_SHIFT);
1308 	}
1309 
1310 	for (; addr != end; addr += PAGE_SIZE) {
1311 		pagemap_entry_t pme = make_pme(frame, flags);
1312 
1313 		err = add_to_pagemap(addr, &pme, pm);
1314 		if (err)
1315 			return err;
1316 		if (pm->show_pfn && (flags & PM_PRESENT))
1317 			frame++;
1318 	}
1319 
1320 	cond_resched();
1321 
1322 	return err;
1323 }
1324 #endif /* HUGETLB_PAGE */
1325 
1326 /*
1327  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1328  *
1329  * For each page in the address space, this file contains one 64-bit entry
1330  * consisting of the following:
1331  *
1332  * Bits 0-54  page frame number (PFN) if present
1333  * Bits 0-4   swap type if swapped
1334  * Bits 5-54  swap offset if swapped
1335  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1336  * Bit  56    page exclusively mapped
1337  * Bits 57-60 zero
1338  * Bit  61    page is file-page or shared-anon
1339  * Bit  62    page swapped
1340  * Bit  63    page present
1341  *
1342  * If the page is not present but in swap, then the PFN contains an
1343  * encoding of the swap file number and the page's offset into the
1344  * swap. Unmapped pages return a null PFN. This allows determining
1345  * precisely which pages are mapped (or in swap) and comparing mapped
1346  * pages between processes.
1347  *
1348  * Efficient users of this interface will use /proc/pid/maps to
1349  * determine which areas of memory are actually mapped and llseek to
1350  * skip over unmapped regions.
1351  */
1352 static ssize_t pagemap_read(struct file *file, char __user *buf,
1353 			    size_t count, loff_t *ppos)
1354 {
1355 	struct mm_struct *mm = file->private_data;
1356 	struct pagemapread pm;
1357 	struct mm_walk pagemap_walk = {};
1358 	unsigned long src;
1359 	unsigned long svpfn;
1360 	unsigned long start_vaddr;
1361 	unsigned long end_vaddr;
1362 	int ret = 0, copied = 0;
1363 
1364 	if (!mm || !mmget_not_zero(mm))
1365 		goto out;
1366 
1367 	ret = -EINVAL;
1368 	/* file position must be aligned */
1369 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1370 		goto out_mm;
1371 
1372 	ret = 0;
1373 	if (!count)
1374 		goto out_mm;
1375 
1376 	/* do not disclose physical addresses: attack vector */
1377 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1378 
1379 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1380 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1381 	ret = -ENOMEM;
1382 	if (!pm.buffer)
1383 		goto out_mm;
1384 
1385 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1386 	pagemap_walk.pte_hole = pagemap_pte_hole;
1387 #ifdef CONFIG_HUGETLB_PAGE
1388 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1389 #endif
1390 	pagemap_walk.mm = mm;
1391 	pagemap_walk.private = &pm;
1392 
1393 	src = *ppos;
1394 	svpfn = src / PM_ENTRY_BYTES;
1395 	start_vaddr = svpfn << PAGE_SHIFT;
1396 	end_vaddr = mm->task_size;
1397 
1398 	/* watch out for wraparound */
1399 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1400 		start_vaddr = end_vaddr;
1401 
1402 	/*
1403 	 * The odds are that this will stop walking way
1404 	 * before end_vaddr, because the length of the
1405 	 * user buffer is tracked in "pm", and the walk
1406 	 * will stop when we hit the end of the buffer.
1407 	 */
1408 	ret = 0;
1409 	while (count && (start_vaddr < end_vaddr)) {
1410 		int len;
1411 		unsigned long end;
1412 
1413 		pm.pos = 0;
1414 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1415 		/* overflow ? */
1416 		if (end < start_vaddr || end > end_vaddr)
1417 			end = end_vaddr;
1418 		down_read(&mm->mmap_sem);
1419 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1420 		up_read(&mm->mmap_sem);
1421 		start_vaddr = end;
1422 
1423 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1424 		if (copy_to_user(buf, pm.buffer, len)) {
1425 			ret = -EFAULT;
1426 			goto out_free;
1427 		}
1428 		copied += len;
1429 		buf += len;
1430 		count -= len;
1431 	}
1432 	*ppos += copied;
1433 	if (!ret || ret == PM_END_OF_BUFFER)
1434 		ret = copied;
1435 
1436 out_free:
1437 	kfree(pm.buffer);
1438 out_mm:
1439 	mmput(mm);
1440 out:
1441 	return ret;
1442 }
1443 
1444 static int pagemap_open(struct inode *inode, struct file *file)
1445 {
1446 	struct mm_struct *mm;
1447 
1448 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1449 	if (IS_ERR(mm))
1450 		return PTR_ERR(mm);
1451 	file->private_data = mm;
1452 	return 0;
1453 }
1454 
1455 static int pagemap_release(struct inode *inode, struct file *file)
1456 {
1457 	struct mm_struct *mm = file->private_data;
1458 
1459 	if (mm)
1460 		mmdrop(mm);
1461 	return 0;
1462 }
1463 
1464 const struct file_operations proc_pagemap_operations = {
1465 	.llseek		= mem_lseek, /* borrow this */
1466 	.read		= pagemap_read,
1467 	.open		= pagemap_open,
1468 	.release	= pagemap_release,
1469 };
1470 #endif /* CONFIG_PROC_PAGE_MONITOR */
1471 
1472 #ifdef CONFIG_NUMA
1473 
1474 struct numa_maps {
1475 	unsigned long pages;
1476 	unsigned long anon;
1477 	unsigned long active;
1478 	unsigned long writeback;
1479 	unsigned long mapcount_max;
1480 	unsigned long dirty;
1481 	unsigned long swapcache;
1482 	unsigned long node[MAX_NUMNODES];
1483 };
1484 
1485 struct numa_maps_private {
1486 	struct proc_maps_private proc_maps;
1487 	struct numa_maps md;
1488 };
1489 
1490 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1491 			unsigned long nr_pages)
1492 {
1493 	int count = page_mapcount(page);
1494 
1495 	md->pages += nr_pages;
1496 	if (pte_dirty || PageDirty(page))
1497 		md->dirty += nr_pages;
1498 
1499 	if (PageSwapCache(page))
1500 		md->swapcache += nr_pages;
1501 
1502 	if (PageActive(page) || PageUnevictable(page))
1503 		md->active += nr_pages;
1504 
1505 	if (PageWriteback(page))
1506 		md->writeback += nr_pages;
1507 
1508 	if (PageAnon(page))
1509 		md->anon += nr_pages;
1510 
1511 	if (count > md->mapcount_max)
1512 		md->mapcount_max = count;
1513 
1514 	md->node[page_to_nid(page)] += nr_pages;
1515 }
1516 
1517 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1518 		unsigned long addr)
1519 {
1520 	struct page *page;
1521 	int nid;
1522 
1523 	if (!pte_present(pte))
1524 		return NULL;
1525 
1526 	page = vm_normal_page(vma, addr, pte);
1527 	if (!page)
1528 		return NULL;
1529 
1530 	if (PageReserved(page))
1531 		return NULL;
1532 
1533 	nid = page_to_nid(page);
1534 	if (!node_isset(nid, node_states[N_MEMORY]))
1535 		return NULL;
1536 
1537 	return page;
1538 }
1539 
1540 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1541 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1542 					      struct vm_area_struct *vma,
1543 					      unsigned long addr)
1544 {
1545 	struct page *page;
1546 	int nid;
1547 
1548 	if (!pmd_present(pmd))
1549 		return NULL;
1550 
1551 	page = vm_normal_page_pmd(vma, addr, pmd);
1552 	if (!page)
1553 		return NULL;
1554 
1555 	if (PageReserved(page))
1556 		return NULL;
1557 
1558 	nid = page_to_nid(page);
1559 	if (!node_isset(nid, node_states[N_MEMORY]))
1560 		return NULL;
1561 
1562 	return page;
1563 }
1564 #endif
1565 
1566 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1567 		unsigned long end, struct mm_walk *walk)
1568 {
1569 	struct numa_maps *md = walk->private;
1570 	struct vm_area_struct *vma = walk->vma;
1571 	spinlock_t *ptl;
1572 	pte_t *orig_pte;
1573 	pte_t *pte;
1574 
1575 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1576 	ptl = pmd_trans_huge_lock(pmd, vma);
1577 	if (ptl) {
1578 		struct page *page;
1579 
1580 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1581 		if (page)
1582 			gather_stats(page, md, pmd_dirty(*pmd),
1583 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1584 		spin_unlock(ptl);
1585 		return 0;
1586 	}
1587 
1588 	if (pmd_trans_unstable(pmd))
1589 		return 0;
1590 #endif
1591 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1592 	do {
1593 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1594 		if (!page)
1595 			continue;
1596 		gather_stats(page, md, pte_dirty(*pte), 1);
1597 
1598 	} while (pte++, addr += PAGE_SIZE, addr != end);
1599 	pte_unmap_unlock(orig_pte, ptl);
1600 	cond_resched();
1601 	return 0;
1602 }
1603 #ifdef CONFIG_HUGETLB_PAGE
1604 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1605 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1606 {
1607 	pte_t huge_pte = huge_ptep_get(pte);
1608 	struct numa_maps *md;
1609 	struct page *page;
1610 
1611 	if (!pte_present(huge_pte))
1612 		return 0;
1613 
1614 	page = pte_page(huge_pte);
1615 	if (!page)
1616 		return 0;
1617 
1618 	md = walk->private;
1619 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1620 	return 0;
1621 }
1622 
1623 #else
1624 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1625 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1626 {
1627 	return 0;
1628 }
1629 #endif
1630 
1631 /*
1632  * Display pages allocated per node and memory policy via /proc.
1633  */
1634 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1635 {
1636 	struct numa_maps_private *numa_priv = m->private;
1637 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1638 	struct vm_area_struct *vma = v;
1639 	struct numa_maps *md = &numa_priv->md;
1640 	struct file *file = vma->vm_file;
1641 	struct mm_struct *mm = vma->vm_mm;
1642 	struct mm_walk walk = {
1643 		.hugetlb_entry = gather_hugetlb_stats,
1644 		.pmd_entry = gather_pte_stats,
1645 		.private = md,
1646 		.mm = mm,
1647 	};
1648 	struct mempolicy *pol;
1649 	char buffer[64];
1650 	int nid;
1651 
1652 	if (!mm)
1653 		return 0;
1654 
1655 	/* Ensure we start with an empty set of numa_maps statistics. */
1656 	memset(md, 0, sizeof(*md));
1657 
1658 	pol = __get_vma_policy(vma, vma->vm_start);
1659 	if (pol) {
1660 		mpol_to_str(buffer, sizeof(buffer), pol);
1661 		mpol_cond_put(pol);
1662 	} else {
1663 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1664 	}
1665 
1666 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1667 
1668 	if (file) {
1669 		seq_puts(m, " file=");
1670 		seq_file_path(m, file, "\n\t= ");
1671 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1672 		seq_puts(m, " heap");
1673 	} else if (is_stack(proc_priv, vma)) {
1674 		seq_puts(m, " stack");
1675 	}
1676 
1677 	if (is_vm_hugetlb_page(vma))
1678 		seq_puts(m, " huge");
1679 
1680 	/* mmap_sem is held by m_start */
1681 	walk_page_vma(vma, &walk);
1682 
1683 	if (!md->pages)
1684 		goto out;
1685 
1686 	if (md->anon)
1687 		seq_printf(m, " anon=%lu", md->anon);
1688 
1689 	if (md->dirty)
1690 		seq_printf(m, " dirty=%lu", md->dirty);
1691 
1692 	if (md->pages != md->anon && md->pages != md->dirty)
1693 		seq_printf(m, " mapped=%lu", md->pages);
1694 
1695 	if (md->mapcount_max > 1)
1696 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1697 
1698 	if (md->swapcache)
1699 		seq_printf(m, " swapcache=%lu", md->swapcache);
1700 
1701 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1702 		seq_printf(m, " active=%lu", md->active);
1703 
1704 	if (md->writeback)
1705 		seq_printf(m, " writeback=%lu", md->writeback);
1706 
1707 	for_each_node_state(nid, N_MEMORY)
1708 		if (md->node[nid])
1709 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1710 
1711 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1712 out:
1713 	seq_putc(m, '\n');
1714 	m_cache_vma(m, vma);
1715 	return 0;
1716 }
1717 
1718 static int show_pid_numa_map(struct seq_file *m, void *v)
1719 {
1720 	return show_numa_map(m, v, 1);
1721 }
1722 
1723 static int show_tid_numa_map(struct seq_file *m, void *v)
1724 {
1725 	return show_numa_map(m, v, 0);
1726 }
1727 
1728 static const struct seq_operations proc_pid_numa_maps_op = {
1729 	.start  = m_start,
1730 	.next   = m_next,
1731 	.stop   = m_stop,
1732 	.show   = show_pid_numa_map,
1733 };
1734 
1735 static const struct seq_operations proc_tid_numa_maps_op = {
1736 	.start  = m_start,
1737 	.next   = m_next,
1738 	.stop   = m_stop,
1739 	.show   = show_tid_numa_map,
1740 };
1741 
1742 static int numa_maps_open(struct inode *inode, struct file *file,
1743 			  const struct seq_operations *ops)
1744 {
1745 	return proc_maps_open(inode, file, ops,
1746 				sizeof(struct numa_maps_private));
1747 }
1748 
1749 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1750 {
1751 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1752 }
1753 
1754 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1755 {
1756 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1757 }
1758 
1759 const struct file_operations proc_pid_numa_maps_operations = {
1760 	.open		= pid_numa_maps_open,
1761 	.read		= seq_read,
1762 	.llseek		= seq_lseek,
1763 	.release	= proc_map_release,
1764 };
1765 
1766 const struct file_operations proc_tid_numa_maps_operations = {
1767 	.open		= tid_numa_maps_open,
1768 	.read		= seq_read,
1769 	.llseek		= seq_lseek,
1770 	.release	= proc_map_release,
1771 };
1772 #endif /* CONFIG_NUMA */
1773