xref: /openbmc/linux/fs/proc/task_mmu.c (revision e639c869)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/mm.h>
3 #include <linux/vmacache.h>
4 #include <linux/hugetlb.h>
5 #include <linux/huge_mm.h>
6 #include <linux/mount.h>
7 #include <linux/seq_file.h>
8 #include <linux/highmem.h>
9 #include <linux/ptrace.h>
10 #include <linux/slab.h>
11 #include <linux/pagemap.h>
12 #include <linux/mempolicy.h>
13 #include <linux/rmap.h>
14 #include <linux/swap.h>
15 #include <linux/sched/mm.h>
16 #include <linux/swapops.h>
17 #include <linux/mmu_notifier.h>
18 #include <linux/page_idle.h>
19 #include <linux/shmem_fs.h>
20 #include <linux/uaccess.h>
21 
22 #include <asm/elf.h>
23 #include <asm/tlb.h>
24 #include <asm/tlbflush.h>
25 #include "internal.h"
26 
27 void task_mem(struct seq_file *m, struct mm_struct *mm)
28 {
29 	unsigned long text, lib, swap, anon, file, shmem;
30 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
31 
32 	anon = get_mm_counter(mm, MM_ANONPAGES);
33 	file = get_mm_counter(mm, MM_FILEPAGES);
34 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
35 
36 	/*
37 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
38 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
39 	 * collector of these hiwater stats must therefore get total_vm
40 	 * and rss too, which will usually be the higher.  Barriers? not
41 	 * worth the effort, such snapshots can always be inconsistent.
42 	 */
43 	hiwater_vm = total_vm = mm->total_vm;
44 	if (hiwater_vm < mm->hiwater_vm)
45 		hiwater_vm = mm->hiwater_vm;
46 	hiwater_rss = total_rss = anon + file + shmem;
47 	if (hiwater_rss < mm->hiwater_rss)
48 		hiwater_rss = mm->hiwater_rss;
49 
50 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
51 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
52 	swap = get_mm_counter(mm, MM_SWAPENTS);
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 		"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 		mm_pgtables_bytes(mm) >> 10,
81 		swap << (PAGE_SHIFT-10));
82 	hugetlb_report_usage(m, mm);
83 }
84 
85 unsigned long task_vsize(struct mm_struct *mm)
86 {
87 	return PAGE_SIZE * mm->total_vm;
88 }
89 
90 unsigned long task_statm(struct mm_struct *mm,
91 			 unsigned long *shared, unsigned long *text,
92 			 unsigned long *data, unsigned long *resident)
93 {
94 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
95 			get_mm_counter(mm, MM_SHMEMPAGES);
96 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
97 								>> PAGE_SHIFT;
98 	*data = mm->data_vm + mm->stack_vm;
99 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
100 	return mm->total_vm;
101 }
102 
103 #ifdef CONFIG_NUMA
104 /*
105  * Save get_task_policy() for show_numa_map().
106  */
107 static void hold_task_mempolicy(struct proc_maps_private *priv)
108 {
109 	struct task_struct *task = priv->task;
110 
111 	task_lock(task);
112 	priv->task_mempolicy = get_task_policy(task);
113 	mpol_get(priv->task_mempolicy);
114 	task_unlock(task);
115 }
116 static void release_task_mempolicy(struct proc_maps_private *priv)
117 {
118 	mpol_put(priv->task_mempolicy);
119 }
120 #else
121 static void hold_task_mempolicy(struct proc_maps_private *priv)
122 {
123 }
124 static void release_task_mempolicy(struct proc_maps_private *priv)
125 {
126 }
127 #endif
128 
129 static void vma_stop(struct proc_maps_private *priv)
130 {
131 	struct mm_struct *mm = priv->mm;
132 
133 	release_task_mempolicy(priv);
134 	up_read(&mm->mmap_sem);
135 	mmput(mm);
136 }
137 
138 static struct vm_area_struct *
139 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
140 {
141 	if (vma == priv->tail_vma)
142 		return NULL;
143 	return vma->vm_next ?: priv->tail_vma;
144 }
145 
146 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
147 {
148 	if (m->count < m->size)	/* vma is copied successfully */
149 		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
150 }
151 
152 static void *m_start(struct seq_file *m, loff_t *ppos)
153 {
154 	struct proc_maps_private *priv = m->private;
155 	unsigned long last_addr = m->version;
156 	struct mm_struct *mm;
157 	struct vm_area_struct *vma;
158 	unsigned int pos = *ppos;
159 
160 	/* See m_cache_vma(). Zero at the start or after lseek. */
161 	if (last_addr == -1UL)
162 		return NULL;
163 
164 	priv->task = get_proc_task(priv->inode);
165 	if (!priv->task)
166 		return ERR_PTR(-ESRCH);
167 
168 	mm = priv->mm;
169 	if (!mm || !mmget_not_zero(mm))
170 		return NULL;
171 
172 	down_read(&mm->mmap_sem);
173 	hold_task_mempolicy(priv);
174 	priv->tail_vma = get_gate_vma(mm);
175 
176 	if (last_addr) {
177 		vma = find_vma(mm, last_addr - 1);
178 		if (vma && vma->vm_start <= last_addr)
179 			vma = m_next_vma(priv, vma);
180 		if (vma)
181 			return vma;
182 	}
183 
184 	m->version = 0;
185 	if (pos < mm->map_count) {
186 		for (vma = mm->mmap; pos; pos--) {
187 			m->version = vma->vm_start;
188 			vma = vma->vm_next;
189 		}
190 		return vma;
191 	}
192 
193 	/* we do not bother to update m->version in this case */
194 	if (pos == mm->map_count && priv->tail_vma)
195 		return priv->tail_vma;
196 
197 	vma_stop(priv);
198 	return NULL;
199 }
200 
201 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
202 {
203 	struct proc_maps_private *priv = m->private;
204 	struct vm_area_struct *next;
205 
206 	(*pos)++;
207 	next = m_next_vma(priv, v);
208 	if (!next)
209 		vma_stop(priv);
210 	return next;
211 }
212 
213 static void m_stop(struct seq_file *m, void *v)
214 {
215 	struct proc_maps_private *priv = m->private;
216 
217 	if (!IS_ERR_OR_NULL(v))
218 		vma_stop(priv);
219 	if (priv->task) {
220 		put_task_struct(priv->task);
221 		priv->task = NULL;
222 	}
223 }
224 
225 static int proc_maps_open(struct inode *inode, struct file *file,
226 			const struct seq_operations *ops, int psize)
227 {
228 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
229 
230 	if (!priv)
231 		return -ENOMEM;
232 
233 	priv->inode = inode;
234 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
235 	if (IS_ERR(priv->mm)) {
236 		int err = PTR_ERR(priv->mm);
237 
238 		seq_release_private(inode, file);
239 		return err;
240 	}
241 
242 	return 0;
243 }
244 
245 static int proc_map_release(struct inode *inode, struct file *file)
246 {
247 	struct seq_file *seq = file->private_data;
248 	struct proc_maps_private *priv = seq->private;
249 
250 	if (priv->mm)
251 		mmdrop(priv->mm);
252 
253 	kfree(priv->rollup);
254 	return seq_release_private(inode, file);
255 }
256 
257 static int do_maps_open(struct inode *inode, struct file *file,
258 			const struct seq_operations *ops)
259 {
260 	return proc_maps_open(inode, file, ops,
261 				sizeof(struct proc_maps_private));
262 }
263 
264 /*
265  * Indicate if the VMA is a stack for the given task; for
266  * /proc/PID/maps that is the stack of the main task.
267  */
268 static int is_stack(struct vm_area_struct *vma)
269 {
270 	/*
271 	 * We make no effort to guess what a given thread considers to be
272 	 * its "stack".  It's not even well-defined for programs written
273 	 * languages like Go.
274 	 */
275 	return vma->vm_start <= vma->vm_mm->start_stack &&
276 		vma->vm_end >= vma->vm_mm->start_stack;
277 }
278 
279 static void show_vma_header_prefix(struct seq_file *m,
280 				   unsigned long start, unsigned long end,
281 				   vm_flags_t flags, unsigned long long pgoff,
282 				   dev_t dev, unsigned long ino)
283 {
284 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
285 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
286 		   start,
287 		   end,
288 		   flags & VM_READ ? 'r' : '-',
289 		   flags & VM_WRITE ? 'w' : '-',
290 		   flags & VM_EXEC ? 'x' : '-',
291 		   flags & VM_MAYSHARE ? 's' : 'p',
292 		   pgoff,
293 		   MAJOR(dev), MINOR(dev), ino);
294 }
295 
296 static void
297 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
298 {
299 	struct mm_struct *mm = vma->vm_mm;
300 	struct file *file = vma->vm_file;
301 	vm_flags_t flags = vma->vm_flags;
302 	unsigned long ino = 0;
303 	unsigned long long pgoff = 0;
304 	unsigned long start, end;
305 	dev_t dev = 0;
306 	const char *name = NULL;
307 
308 	if (file) {
309 		struct inode *inode = file_inode(vma->vm_file);
310 		dev = inode->i_sb->s_dev;
311 		ino = inode->i_ino;
312 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
313 	}
314 
315 	start = vma->vm_start;
316 	end = vma->vm_end;
317 	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
318 
319 	/*
320 	 * Print the dentry name for named mappings, and a
321 	 * special [heap] marker for the heap:
322 	 */
323 	if (file) {
324 		seq_pad(m, ' ');
325 		seq_file_path(m, file, "\n");
326 		goto done;
327 	}
328 
329 	if (vma->vm_ops && vma->vm_ops->name) {
330 		name = vma->vm_ops->name(vma);
331 		if (name)
332 			goto done;
333 	}
334 
335 	name = arch_vma_name(vma);
336 	if (!name) {
337 		if (!mm) {
338 			name = "[vdso]";
339 			goto done;
340 		}
341 
342 		if (vma->vm_start <= mm->brk &&
343 		    vma->vm_end >= mm->start_brk) {
344 			name = "[heap]";
345 			goto done;
346 		}
347 
348 		if (is_stack(vma))
349 			name = "[stack]";
350 	}
351 
352 done:
353 	if (name) {
354 		seq_pad(m, ' ');
355 		seq_puts(m, name);
356 	}
357 	seq_putc(m, '\n');
358 }
359 
360 static int show_map(struct seq_file *m, void *v, int is_pid)
361 {
362 	show_map_vma(m, v, is_pid);
363 	m_cache_vma(m, v);
364 	return 0;
365 }
366 
367 static int show_pid_map(struct seq_file *m, void *v)
368 {
369 	return show_map(m, v, 1);
370 }
371 
372 static int show_tid_map(struct seq_file *m, void *v)
373 {
374 	return show_map(m, v, 0);
375 }
376 
377 static const struct seq_operations proc_pid_maps_op = {
378 	.start	= m_start,
379 	.next	= m_next,
380 	.stop	= m_stop,
381 	.show	= show_pid_map
382 };
383 
384 static const struct seq_operations proc_tid_maps_op = {
385 	.start	= m_start,
386 	.next	= m_next,
387 	.stop	= m_stop,
388 	.show	= show_tid_map
389 };
390 
391 static int pid_maps_open(struct inode *inode, struct file *file)
392 {
393 	return do_maps_open(inode, file, &proc_pid_maps_op);
394 }
395 
396 static int tid_maps_open(struct inode *inode, struct file *file)
397 {
398 	return do_maps_open(inode, file, &proc_tid_maps_op);
399 }
400 
401 const struct file_operations proc_pid_maps_operations = {
402 	.open		= pid_maps_open,
403 	.read		= seq_read,
404 	.llseek		= seq_lseek,
405 	.release	= proc_map_release,
406 };
407 
408 const struct file_operations proc_tid_maps_operations = {
409 	.open		= tid_maps_open,
410 	.read		= seq_read,
411 	.llseek		= seq_lseek,
412 	.release	= proc_map_release,
413 };
414 
415 /*
416  * Proportional Set Size(PSS): my share of RSS.
417  *
418  * PSS of a process is the count of pages it has in memory, where each
419  * page is divided by the number of processes sharing it.  So if a
420  * process has 1000 pages all to itself, and 1000 shared with one other
421  * process, its PSS will be 1500.
422  *
423  * To keep (accumulated) division errors low, we adopt a 64bit
424  * fixed-point pss counter to minimize division errors. So (pss >>
425  * PSS_SHIFT) would be the real byte count.
426  *
427  * A shift of 12 before division means (assuming 4K page size):
428  * 	- 1M 3-user-pages add up to 8KB errors;
429  * 	- supports mapcount up to 2^24, or 16M;
430  * 	- supports PSS up to 2^52 bytes, or 4PB.
431  */
432 #define PSS_SHIFT 12
433 
434 #ifdef CONFIG_PROC_PAGE_MONITOR
435 struct mem_size_stats {
436 	bool first;
437 	unsigned long resident;
438 	unsigned long shared_clean;
439 	unsigned long shared_dirty;
440 	unsigned long private_clean;
441 	unsigned long private_dirty;
442 	unsigned long referenced;
443 	unsigned long anonymous;
444 	unsigned long lazyfree;
445 	unsigned long anonymous_thp;
446 	unsigned long shmem_thp;
447 	unsigned long swap;
448 	unsigned long shared_hugetlb;
449 	unsigned long private_hugetlb;
450 	unsigned long first_vma_start;
451 	u64 pss;
452 	u64 pss_locked;
453 	u64 swap_pss;
454 	bool check_shmem_swap;
455 };
456 
457 static void smaps_account(struct mem_size_stats *mss, struct page *page,
458 		bool compound, bool young, bool dirty)
459 {
460 	int i, nr = compound ? 1 << compound_order(page) : 1;
461 	unsigned long size = nr * PAGE_SIZE;
462 
463 	if (PageAnon(page)) {
464 		mss->anonymous += size;
465 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
466 			mss->lazyfree += size;
467 	}
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 (is_device_private_entry(swpent))
548 			page = device_private_entry_to_page(swpent);
549 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
550 							&& pte_none(*pte))) {
551 		page = find_get_entry(vma->vm_file->f_mapping,
552 						linear_page_index(vma, addr));
553 		if (!page)
554 			return;
555 
556 		if (radix_tree_exceptional_entry(page))
557 			mss->swap += PAGE_SIZE;
558 		else
559 			put_page(page);
560 
561 		return;
562 	}
563 
564 	if (!page)
565 		return;
566 
567 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
568 }
569 
570 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
571 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
572 		struct mm_walk *walk)
573 {
574 	struct mem_size_stats *mss = walk->private;
575 	struct vm_area_struct *vma = walk->vma;
576 	struct page *page;
577 
578 	/* FOLL_DUMP will return -EFAULT on huge zero page */
579 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
580 	if (IS_ERR_OR_NULL(page))
581 		return;
582 	if (PageAnon(page))
583 		mss->anonymous_thp += HPAGE_PMD_SIZE;
584 	else if (PageSwapBacked(page))
585 		mss->shmem_thp += HPAGE_PMD_SIZE;
586 	else if (is_zone_device_page(page))
587 		/* pass */;
588 	else
589 		VM_BUG_ON_PAGE(1, page);
590 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
591 }
592 #else
593 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
594 		struct mm_walk *walk)
595 {
596 }
597 #endif
598 
599 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
600 			   struct mm_walk *walk)
601 {
602 	struct vm_area_struct *vma = walk->vma;
603 	pte_t *pte;
604 	spinlock_t *ptl;
605 
606 	ptl = pmd_trans_huge_lock(pmd, vma);
607 	if (ptl) {
608 		if (pmd_present(*pmd))
609 			smaps_pmd_entry(pmd, addr, walk);
610 		spin_unlock(ptl);
611 		goto out;
612 	}
613 
614 	if (pmd_trans_unstable(pmd))
615 		goto out;
616 	/*
617 	 * The mmap_sem held all the way back in m_start() is what
618 	 * keeps khugepaged out of here and from collapsing things
619 	 * in here.
620 	 */
621 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
622 	for (; addr != end; pte++, addr += PAGE_SIZE)
623 		smaps_pte_entry(pte, addr, walk);
624 	pte_unmap_unlock(pte - 1, ptl);
625 out:
626 	cond_resched();
627 	return 0;
628 }
629 
630 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
631 {
632 	/*
633 	 * Don't forget to update Documentation/ on changes.
634 	 */
635 	static const char mnemonics[BITS_PER_LONG][2] = {
636 		/*
637 		 * In case if we meet a flag we don't know about.
638 		 */
639 		[0 ... (BITS_PER_LONG-1)] = "??",
640 
641 		[ilog2(VM_READ)]	= "rd",
642 		[ilog2(VM_WRITE)]	= "wr",
643 		[ilog2(VM_EXEC)]	= "ex",
644 		[ilog2(VM_SHARED)]	= "sh",
645 		[ilog2(VM_MAYREAD)]	= "mr",
646 		[ilog2(VM_MAYWRITE)]	= "mw",
647 		[ilog2(VM_MAYEXEC)]	= "me",
648 		[ilog2(VM_MAYSHARE)]	= "ms",
649 		[ilog2(VM_GROWSDOWN)]	= "gd",
650 		[ilog2(VM_PFNMAP)]	= "pf",
651 		[ilog2(VM_DENYWRITE)]	= "dw",
652 #ifdef CONFIG_X86_INTEL_MPX
653 		[ilog2(VM_MPX)]		= "mp",
654 #endif
655 		[ilog2(VM_LOCKED)]	= "lo",
656 		[ilog2(VM_IO)]		= "io",
657 		[ilog2(VM_SEQ_READ)]	= "sr",
658 		[ilog2(VM_RAND_READ)]	= "rr",
659 		[ilog2(VM_DONTCOPY)]	= "dc",
660 		[ilog2(VM_DONTEXPAND)]	= "de",
661 		[ilog2(VM_ACCOUNT)]	= "ac",
662 		[ilog2(VM_NORESERVE)]	= "nr",
663 		[ilog2(VM_HUGETLB)]	= "ht",
664 		[ilog2(VM_SYNC)]	= "sf",
665 		[ilog2(VM_ARCH_1)]	= "ar",
666 		[ilog2(VM_WIPEONFORK)]	= "wf",
667 		[ilog2(VM_DONTDUMP)]	= "dd",
668 #ifdef CONFIG_MEM_SOFT_DIRTY
669 		[ilog2(VM_SOFTDIRTY)]	= "sd",
670 #endif
671 		[ilog2(VM_MIXEDMAP)]	= "mm",
672 		[ilog2(VM_HUGEPAGE)]	= "hg",
673 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
674 		[ilog2(VM_MERGEABLE)]	= "mg",
675 		[ilog2(VM_UFFD_MISSING)]= "um",
676 		[ilog2(VM_UFFD_WP)]	= "uw",
677 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
678 		/* These come out via ProtectionKey: */
679 		[ilog2(VM_PKEY_BIT0)]	= "",
680 		[ilog2(VM_PKEY_BIT1)]	= "",
681 		[ilog2(VM_PKEY_BIT2)]	= "",
682 		[ilog2(VM_PKEY_BIT3)]	= "",
683 #endif
684 	};
685 	size_t i;
686 
687 	seq_puts(m, "VmFlags: ");
688 	for (i = 0; i < BITS_PER_LONG; i++) {
689 		if (!mnemonics[i][0])
690 			continue;
691 		if (vma->vm_flags & (1UL << i)) {
692 			seq_printf(m, "%c%c ",
693 				   mnemonics[i][0], mnemonics[i][1]);
694 		}
695 	}
696 	seq_putc(m, '\n');
697 }
698 
699 #ifdef CONFIG_HUGETLB_PAGE
700 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
701 				 unsigned long addr, unsigned long end,
702 				 struct mm_walk *walk)
703 {
704 	struct mem_size_stats *mss = walk->private;
705 	struct vm_area_struct *vma = walk->vma;
706 	struct page *page = NULL;
707 
708 	if (pte_present(*pte)) {
709 		page = vm_normal_page(vma, addr, *pte);
710 	} else if (is_swap_pte(*pte)) {
711 		swp_entry_t swpent = pte_to_swp_entry(*pte);
712 
713 		if (is_migration_entry(swpent))
714 			page = migration_entry_to_page(swpent);
715 		else if (is_device_private_entry(swpent))
716 			page = device_private_entry_to_page(swpent);
717 	}
718 	if (page) {
719 		int mapcount = page_mapcount(page);
720 
721 		if (mapcount >= 2)
722 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
723 		else
724 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
725 	}
726 	return 0;
727 }
728 #endif /* HUGETLB_PAGE */
729 
730 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
731 {
732 }
733 
734 static int show_smap(struct seq_file *m, void *v, int is_pid)
735 {
736 	struct proc_maps_private *priv = m->private;
737 	struct vm_area_struct *vma = v;
738 	struct mem_size_stats mss_stack;
739 	struct mem_size_stats *mss;
740 	struct mm_walk smaps_walk = {
741 		.pmd_entry = smaps_pte_range,
742 #ifdef CONFIG_HUGETLB_PAGE
743 		.hugetlb_entry = smaps_hugetlb_range,
744 #endif
745 		.mm = vma->vm_mm,
746 	};
747 	int ret = 0;
748 	bool rollup_mode;
749 	bool last_vma;
750 
751 	if (priv->rollup) {
752 		rollup_mode = true;
753 		mss = priv->rollup;
754 		if (mss->first) {
755 			mss->first_vma_start = vma->vm_start;
756 			mss->first = false;
757 		}
758 		last_vma = !m_next_vma(priv, vma);
759 	} else {
760 		rollup_mode = false;
761 		memset(&mss_stack, 0, sizeof(mss_stack));
762 		mss = &mss_stack;
763 	}
764 
765 	smaps_walk.private = mss;
766 
767 #ifdef CONFIG_SHMEM
768 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
769 		/*
770 		 * For shared or readonly shmem mappings we know that all
771 		 * swapped out pages belong to the shmem object, and we can
772 		 * obtain the swap value much more efficiently. For private
773 		 * writable mappings, we might have COW pages that are
774 		 * not affected by the parent swapped out pages of the shmem
775 		 * object, so we have to distinguish them during the page walk.
776 		 * Unless we know that the shmem object (or the part mapped by
777 		 * our VMA) has no swapped out pages at all.
778 		 */
779 		unsigned long shmem_swapped = shmem_swap_usage(vma);
780 
781 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
782 					!(vma->vm_flags & VM_WRITE)) {
783 			mss->swap = shmem_swapped;
784 		} else {
785 			mss->check_shmem_swap = true;
786 			smaps_walk.pte_hole = smaps_pte_hole;
787 		}
788 	}
789 #endif
790 
791 	/* mmap_sem is held in m_start */
792 	walk_page_vma(vma, &smaps_walk);
793 	if (vma->vm_flags & VM_LOCKED)
794 		mss->pss_locked += mss->pss;
795 
796 	if (!rollup_mode) {
797 		show_map_vma(m, vma, is_pid);
798 	} else if (last_vma) {
799 		show_vma_header_prefix(
800 			m, mss->first_vma_start, vma->vm_end, 0, 0, 0, 0);
801 		seq_pad(m, ' ');
802 		seq_puts(m, "[rollup]\n");
803 	} else {
804 		ret = SEQ_SKIP;
805 	}
806 
807 	if (!rollup_mode)
808 		seq_printf(m,
809 			   "Size:           %8lu kB\n"
810 			   "KernelPageSize: %8lu kB\n"
811 			   "MMUPageSize:    %8lu kB\n",
812 			   (vma->vm_end - vma->vm_start) >> 10,
813 			   vma_kernel_pagesize(vma) >> 10,
814 			   vma_mmu_pagesize(vma) >> 10);
815 
816 
817 	if (!rollup_mode || last_vma)
818 		seq_printf(m,
819 			   "Rss:            %8lu kB\n"
820 			   "Pss:            %8lu kB\n"
821 			   "Shared_Clean:   %8lu kB\n"
822 			   "Shared_Dirty:   %8lu kB\n"
823 			   "Private_Clean:  %8lu kB\n"
824 			   "Private_Dirty:  %8lu kB\n"
825 			   "Referenced:     %8lu kB\n"
826 			   "Anonymous:      %8lu kB\n"
827 			   "LazyFree:       %8lu kB\n"
828 			   "AnonHugePages:  %8lu kB\n"
829 			   "ShmemPmdMapped: %8lu kB\n"
830 			   "Shared_Hugetlb: %8lu kB\n"
831 			   "Private_Hugetlb: %7lu kB\n"
832 			   "Swap:           %8lu kB\n"
833 			   "SwapPss:        %8lu kB\n"
834 			   "Locked:         %8lu kB\n",
835 			   mss->resident >> 10,
836 			   (unsigned long)(mss->pss >> (10 + PSS_SHIFT)),
837 			   mss->shared_clean  >> 10,
838 			   mss->shared_dirty  >> 10,
839 			   mss->private_clean >> 10,
840 			   mss->private_dirty >> 10,
841 			   mss->referenced >> 10,
842 			   mss->anonymous >> 10,
843 			   mss->lazyfree >> 10,
844 			   mss->anonymous_thp >> 10,
845 			   mss->shmem_thp >> 10,
846 			   mss->shared_hugetlb >> 10,
847 			   mss->private_hugetlb >> 10,
848 			   mss->swap >> 10,
849 			   (unsigned long)(mss->swap_pss >> (10 + PSS_SHIFT)),
850 			   (unsigned long)(mss->pss >> (10 + PSS_SHIFT)));
851 
852 	if (!rollup_mode) {
853 		arch_show_smap(m, vma);
854 		show_smap_vma_flags(m, vma);
855 	}
856 	m_cache_vma(m, vma);
857 	return ret;
858 }
859 
860 static int show_pid_smap(struct seq_file *m, void *v)
861 {
862 	return show_smap(m, v, 1);
863 }
864 
865 static int show_tid_smap(struct seq_file *m, void *v)
866 {
867 	return show_smap(m, v, 0);
868 }
869 
870 static const struct seq_operations proc_pid_smaps_op = {
871 	.start	= m_start,
872 	.next	= m_next,
873 	.stop	= m_stop,
874 	.show	= show_pid_smap
875 };
876 
877 static const struct seq_operations proc_tid_smaps_op = {
878 	.start	= m_start,
879 	.next	= m_next,
880 	.stop	= m_stop,
881 	.show	= show_tid_smap
882 };
883 
884 static int pid_smaps_open(struct inode *inode, struct file *file)
885 {
886 	return do_maps_open(inode, file, &proc_pid_smaps_op);
887 }
888 
889 static int pid_smaps_rollup_open(struct inode *inode, struct file *file)
890 {
891 	struct seq_file *seq;
892 	struct proc_maps_private *priv;
893 	int ret = do_maps_open(inode, file, &proc_pid_smaps_op);
894 
895 	if (ret < 0)
896 		return ret;
897 	seq = file->private_data;
898 	priv = seq->private;
899 	priv->rollup = kzalloc(sizeof(*priv->rollup), GFP_KERNEL);
900 	if (!priv->rollup) {
901 		proc_map_release(inode, file);
902 		return -ENOMEM;
903 	}
904 	priv->rollup->first = true;
905 	return 0;
906 }
907 
908 static int tid_smaps_open(struct inode *inode, struct file *file)
909 {
910 	return do_maps_open(inode, file, &proc_tid_smaps_op);
911 }
912 
913 const struct file_operations proc_pid_smaps_operations = {
914 	.open		= pid_smaps_open,
915 	.read		= seq_read,
916 	.llseek		= seq_lseek,
917 	.release	= proc_map_release,
918 };
919 
920 const struct file_operations proc_pid_smaps_rollup_operations = {
921 	.open		= pid_smaps_rollup_open,
922 	.read		= seq_read,
923 	.llseek		= seq_lseek,
924 	.release	= proc_map_release,
925 };
926 
927 const struct file_operations proc_tid_smaps_operations = {
928 	.open		= tid_smaps_open,
929 	.read		= seq_read,
930 	.llseek		= seq_lseek,
931 	.release	= proc_map_release,
932 };
933 
934 enum clear_refs_types {
935 	CLEAR_REFS_ALL = 1,
936 	CLEAR_REFS_ANON,
937 	CLEAR_REFS_MAPPED,
938 	CLEAR_REFS_SOFT_DIRTY,
939 	CLEAR_REFS_MM_HIWATER_RSS,
940 	CLEAR_REFS_LAST,
941 };
942 
943 struct clear_refs_private {
944 	enum clear_refs_types type;
945 };
946 
947 #ifdef CONFIG_MEM_SOFT_DIRTY
948 static inline void clear_soft_dirty(struct vm_area_struct *vma,
949 		unsigned long addr, pte_t *pte)
950 {
951 	/*
952 	 * The soft-dirty tracker uses #PF-s to catch writes
953 	 * to pages, so write-protect the pte as well. See the
954 	 * Documentation/vm/soft-dirty.txt for full description
955 	 * of how soft-dirty works.
956 	 */
957 	pte_t ptent = *pte;
958 
959 	if (pte_present(ptent)) {
960 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
961 		ptent = pte_wrprotect(ptent);
962 		ptent = pte_clear_soft_dirty(ptent);
963 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
964 	} else if (is_swap_pte(ptent)) {
965 		ptent = pte_swp_clear_soft_dirty(ptent);
966 		set_pte_at(vma->vm_mm, addr, pte, ptent);
967 	}
968 }
969 #else
970 static inline void clear_soft_dirty(struct vm_area_struct *vma,
971 		unsigned long addr, pte_t *pte)
972 {
973 }
974 #endif
975 
976 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
977 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
978 		unsigned long addr, pmd_t *pmdp)
979 {
980 	pmd_t pmd = *pmdp;
981 
982 	if (pmd_present(pmd)) {
983 		/* See comment in change_huge_pmd() */
984 		pmdp_invalidate(vma, addr, pmdp);
985 		if (pmd_dirty(*pmdp))
986 			pmd = pmd_mkdirty(pmd);
987 		if (pmd_young(*pmdp))
988 			pmd = pmd_mkyoung(pmd);
989 
990 		pmd = pmd_wrprotect(pmd);
991 		pmd = pmd_clear_soft_dirty(pmd);
992 
993 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
994 	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
995 		pmd = pmd_swp_clear_soft_dirty(pmd);
996 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
997 	}
998 }
999 #else
1000 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1001 		unsigned long addr, pmd_t *pmdp)
1002 {
1003 }
1004 #endif
1005 
1006 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1007 				unsigned long end, struct mm_walk *walk)
1008 {
1009 	struct clear_refs_private *cp = walk->private;
1010 	struct vm_area_struct *vma = walk->vma;
1011 	pte_t *pte, ptent;
1012 	spinlock_t *ptl;
1013 	struct page *page;
1014 
1015 	ptl = pmd_trans_huge_lock(pmd, vma);
1016 	if (ptl) {
1017 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1018 			clear_soft_dirty_pmd(vma, addr, pmd);
1019 			goto out;
1020 		}
1021 
1022 		if (!pmd_present(*pmd))
1023 			goto out;
1024 
1025 		page = pmd_page(*pmd);
1026 
1027 		/* Clear accessed and referenced bits. */
1028 		pmdp_test_and_clear_young(vma, addr, pmd);
1029 		test_and_clear_page_young(page);
1030 		ClearPageReferenced(page);
1031 out:
1032 		spin_unlock(ptl);
1033 		return 0;
1034 	}
1035 
1036 	if (pmd_trans_unstable(pmd))
1037 		return 0;
1038 
1039 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1040 	for (; addr != end; pte++, addr += PAGE_SIZE) {
1041 		ptent = *pte;
1042 
1043 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1044 			clear_soft_dirty(vma, addr, pte);
1045 			continue;
1046 		}
1047 
1048 		if (!pte_present(ptent))
1049 			continue;
1050 
1051 		page = vm_normal_page(vma, addr, ptent);
1052 		if (!page)
1053 			continue;
1054 
1055 		/* Clear accessed and referenced bits. */
1056 		ptep_test_and_clear_young(vma, addr, pte);
1057 		test_and_clear_page_young(page);
1058 		ClearPageReferenced(page);
1059 	}
1060 	pte_unmap_unlock(pte - 1, ptl);
1061 	cond_resched();
1062 	return 0;
1063 }
1064 
1065 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1066 				struct mm_walk *walk)
1067 {
1068 	struct clear_refs_private *cp = walk->private;
1069 	struct vm_area_struct *vma = walk->vma;
1070 
1071 	if (vma->vm_flags & VM_PFNMAP)
1072 		return 1;
1073 
1074 	/*
1075 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1076 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1077 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1078 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1079 	 */
1080 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1081 		return 1;
1082 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1083 		return 1;
1084 	return 0;
1085 }
1086 
1087 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1088 				size_t count, loff_t *ppos)
1089 {
1090 	struct task_struct *task;
1091 	char buffer[PROC_NUMBUF];
1092 	struct mm_struct *mm;
1093 	struct vm_area_struct *vma;
1094 	enum clear_refs_types type;
1095 	struct mmu_gather tlb;
1096 	int itype;
1097 	int rv;
1098 
1099 	memset(buffer, 0, sizeof(buffer));
1100 	if (count > sizeof(buffer) - 1)
1101 		count = sizeof(buffer) - 1;
1102 	if (copy_from_user(buffer, buf, count))
1103 		return -EFAULT;
1104 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1105 	if (rv < 0)
1106 		return rv;
1107 	type = (enum clear_refs_types)itype;
1108 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1109 		return -EINVAL;
1110 
1111 	task = get_proc_task(file_inode(file));
1112 	if (!task)
1113 		return -ESRCH;
1114 	mm = get_task_mm(task);
1115 	if (mm) {
1116 		struct clear_refs_private cp = {
1117 			.type = type,
1118 		};
1119 		struct mm_walk clear_refs_walk = {
1120 			.pmd_entry = clear_refs_pte_range,
1121 			.test_walk = clear_refs_test_walk,
1122 			.mm = mm,
1123 			.private = &cp,
1124 		};
1125 
1126 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1127 			if (down_write_killable(&mm->mmap_sem)) {
1128 				count = -EINTR;
1129 				goto out_mm;
1130 			}
1131 
1132 			/*
1133 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1134 			 * resident set size to this mm's current rss value.
1135 			 */
1136 			reset_mm_hiwater_rss(mm);
1137 			up_write(&mm->mmap_sem);
1138 			goto out_mm;
1139 		}
1140 
1141 		down_read(&mm->mmap_sem);
1142 		tlb_gather_mmu(&tlb, mm, 0, -1);
1143 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1144 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1145 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1146 					continue;
1147 				up_read(&mm->mmap_sem);
1148 				if (down_write_killable(&mm->mmap_sem)) {
1149 					count = -EINTR;
1150 					goto out_mm;
1151 				}
1152 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1153 					vma->vm_flags &= ~VM_SOFTDIRTY;
1154 					vma_set_page_prot(vma);
1155 				}
1156 				downgrade_write(&mm->mmap_sem);
1157 				break;
1158 			}
1159 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1160 		}
1161 		walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1162 		if (type == CLEAR_REFS_SOFT_DIRTY)
1163 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1164 		tlb_finish_mmu(&tlb, 0, -1);
1165 		up_read(&mm->mmap_sem);
1166 out_mm:
1167 		mmput(mm);
1168 	}
1169 	put_task_struct(task);
1170 
1171 	return count;
1172 }
1173 
1174 const struct file_operations proc_clear_refs_operations = {
1175 	.write		= clear_refs_write,
1176 	.llseek		= noop_llseek,
1177 };
1178 
1179 typedef struct {
1180 	u64 pme;
1181 } pagemap_entry_t;
1182 
1183 struct pagemapread {
1184 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1185 	pagemap_entry_t *buffer;
1186 	bool show_pfn;
1187 };
1188 
1189 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1190 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1191 
1192 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1193 #define PM_PFRAME_BITS		55
1194 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1195 #define PM_SOFT_DIRTY		BIT_ULL(55)
1196 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1197 #define PM_FILE			BIT_ULL(61)
1198 #define PM_SWAP			BIT_ULL(62)
1199 #define PM_PRESENT		BIT_ULL(63)
1200 
1201 #define PM_END_OF_BUFFER    1
1202 
1203 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1204 {
1205 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1206 }
1207 
1208 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1209 			  struct pagemapread *pm)
1210 {
1211 	pm->buffer[pm->pos++] = *pme;
1212 	if (pm->pos >= pm->len)
1213 		return PM_END_OF_BUFFER;
1214 	return 0;
1215 }
1216 
1217 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1218 				struct mm_walk *walk)
1219 {
1220 	struct pagemapread *pm = walk->private;
1221 	unsigned long addr = start;
1222 	int err = 0;
1223 
1224 	while (addr < end) {
1225 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1226 		pagemap_entry_t pme = make_pme(0, 0);
1227 		/* End of address space hole, which we mark as non-present. */
1228 		unsigned long hole_end;
1229 
1230 		if (vma)
1231 			hole_end = min(end, vma->vm_start);
1232 		else
1233 			hole_end = end;
1234 
1235 		for (; addr < hole_end; addr += PAGE_SIZE) {
1236 			err = add_to_pagemap(addr, &pme, pm);
1237 			if (err)
1238 				goto out;
1239 		}
1240 
1241 		if (!vma)
1242 			break;
1243 
1244 		/* Addresses in the VMA. */
1245 		if (vma->vm_flags & VM_SOFTDIRTY)
1246 			pme = make_pme(0, PM_SOFT_DIRTY);
1247 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1248 			err = add_to_pagemap(addr, &pme, pm);
1249 			if (err)
1250 				goto out;
1251 		}
1252 	}
1253 out:
1254 	return err;
1255 }
1256 
1257 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1258 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1259 {
1260 	u64 frame = 0, flags = 0;
1261 	struct page *page = NULL;
1262 
1263 	if (pte_present(pte)) {
1264 		if (pm->show_pfn)
1265 			frame = pte_pfn(pte);
1266 		flags |= PM_PRESENT;
1267 		page = _vm_normal_page(vma, addr, pte, true);
1268 		if (pte_soft_dirty(pte))
1269 			flags |= PM_SOFT_DIRTY;
1270 	} else if (is_swap_pte(pte)) {
1271 		swp_entry_t entry;
1272 		if (pte_swp_soft_dirty(pte))
1273 			flags |= PM_SOFT_DIRTY;
1274 		entry = pte_to_swp_entry(pte);
1275 		frame = swp_type(entry) |
1276 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1277 		flags |= PM_SWAP;
1278 		if (is_migration_entry(entry))
1279 			page = migration_entry_to_page(entry);
1280 
1281 		if (is_device_private_entry(entry))
1282 			page = device_private_entry_to_page(entry);
1283 	}
1284 
1285 	if (page && !PageAnon(page))
1286 		flags |= PM_FILE;
1287 	if (page && page_mapcount(page) == 1)
1288 		flags |= PM_MMAP_EXCLUSIVE;
1289 	if (vma->vm_flags & VM_SOFTDIRTY)
1290 		flags |= PM_SOFT_DIRTY;
1291 
1292 	return make_pme(frame, flags);
1293 }
1294 
1295 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1296 			     struct mm_walk *walk)
1297 {
1298 	struct vm_area_struct *vma = walk->vma;
1299 	struct pagemapread *pm = walk->private;
1300 	spinlock_t *ptl;
1301 	pte_t *pte, *orig_pte;
1302 	int err = 0;
1303 
1304 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1305 	ptl = pmd_trans_huge_lock(pmdp, vma);
1306 	if (ptl) {
1307 		u64 flags = 0, frame = 0;
1308 		pmd_t pmd = *pmdp;
1309 		struct page *page = NULL;
1310 
1311 		if (vma->vm_flags & VM_SOFTDIRTY)
1312 			flags |= PM_SOFT_DIRTY;
1313 
1314 		if (pmd_present(pmd)) {
1315 			page = pmd_page(pmd);
1316 
1317 			flags |= PM_PRESENT;
1318 			if (pmd_soft_dirty(pmd))
1319 				flags |= PM_SOFT_DIRTY;
1320 			if (pm->show_pfn)
1321 				frame = pmd_pfn(pmd) +
1322 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1323 		}
1324 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1325 		else if (is_swap_pmd(pmd)) {
1326 			swp_entry_t entry = pmd_to_swp_entry(pmd);
1327 
1328 			frame = swp_type(entry) |
1329 				(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1330 			flags |= PM_SWAP;
1331 			if (pmd_swp_soft_dirty(pmd))
1332 				flags |= PM_SOFT_DIRTY;
1333 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1334 			page = migration_entry_to_page(entry);
1335 		}
1336 #endif
1337 
1338 		if (page && page_mapcount(page) == 1)
1339 			flags |= PM_MMAP_EXCLUSIVE;
1340 
1341 		for (; addr != end; addr += PAGE_SIZE) {
1342 			pagemap_entry_t pme = make_pme(frame, flags);
1343 
1344 			err = add_to_pagemap(addr, &pme, pm);
1345 			if (err)
1346 				break;
1347 			if (pm->show_pfn && (flags & PM_PRESENT))
1348 				frame++;
1349 		}
1350 		spin_unlock(ptl);
1351 		return err;
1352 	}
1353 
1354 	if (pmd_trans_unstable(pmdp))
1355 		return 0;
1356 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1357 
1358 	/*
1359 	 * We can assume that @vma always points to a valid one and @end never
1360 	 * goes beyond vma->vm_end.
1361 	 */
1362 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1363 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1364 		pagemap_entry_t pme;
1365 
1366 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1367 		err = add_to_pagemap(addr, &pme, pm);
1368 		if (err)
1369 			break;
1370 	}
1371 	pte_unmap_unlock(orig_pte, ptl);
1372 
1373 	cond_resched();
1374 
1375 	return err;
1376 }
1377 
1378 #ifdef CONFIG_HUGETLB_PAGE
1379 /* This function walks within one hugetlb entry in the single call */
1380 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1381 				 unsigned long addr, unsigned long end,
1382 				 struct mm_walk *walk)
1383 {
1384 	struct pagemapread *pm = walk->private;
1385 	struct vm_area_struct *vma = walk->vma;
1386 	u64 flags = 0, frame = 0;
1387 	int err = 0;
1388 	pte_t pte;
1389 
1390 	if (vma->vm_flags & VM_SOFTDIRTY)
1391 		flags |= PM_SOFT_DIRTY;
1392 
1393 	pte = huge_ptep_get(ptep);
1394 	if (pte_present(pte)) {
1395 		struct page *page = pte_page(pte);
1396 
1397 		if (!PageAnon(page))
1398 			flags |= PM_FILE;
1399 
1400 		if (page_mapcount(page) == 1)
1401 			flags |= PM_MMAP_EXCLUSIVE;
1402 
1403 		flags |= PM_PRESENT;
1404 		if (pm->show_pfn)
1405 			frame = pte_pfn(pte) +
1406 				((addr & ~hmask) >> PAGE_SHIFT);
1407 	}
1408 
1409 	for (; addr != end; addr += PAGE_SIZE) {
1410 		pagemap_entry_t pme = make_pme(frame, flags);
1411 
1412 		err = add_to_pagemap(addr, &pme, pm);
1413 		if (err)
1414 			return err;
1415 		if (pm->show_pfn && (flags & PM_PRESENT))
1416 			frame++;
1417 	}
1418 
1419 	cond_resched();
1420 
1421 	return err;
1422 }
1423 #endif /* HUGETLB_PAGE */
1424 
1425 /*
1426  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1427  *
1428  * For each page in the address space, this file contains one 64-bit entry
1429  * consisting of the following:
1430  *
1431  * Bits 0-54  page frame number (PFN) if present
1432  * Bits 0-4   swap type if swapped
1433  * Bits 5-54  swap offset if swapped
1434  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1435  * Bit  56    page exclusively mapped
1436  * Bits 57-60 zero
1437  * Bit  61    page is file-page or shared-anon
1438  * Bit  62    page swapped
1439  * Bit  63    page present
1440  *
1441  * If the page is not present but in swap, then the PFN contains an
1442  * encoding of the swap file number and the page's offset into the
1443  * swap. Unmapped pages return a null PFN. This allows determining
1444  * precisely which pages are mapped (or in swap) and comparing mapped
1445  * pages between processes.
1446  *
1447  * Efficient users of this interface will use /proc/pid/maps to
1448  * determine which areas of memory are actually mapped and llseek to
1449  * skip over unmapped regions.
1450  */
1451 static ssize_t pagemap_read(struct file *file, char __user *buf,
1452 			    size_t count, loff_t *ppos)
1453 {
1454 	struct mm_struct *mm = file->private_data;
1455 	struct pagemapread pm;
1456 	struct mm_walk pagemap_walk = {};
1457 	unsigned long src;
1458 	unsigned long svpfn;
1459 	unsigned long start_vaddr;
1460 	unsigned long end_vaddr;
1461 	int ret = 0, copied = 0;
1462 
1463 	if (!mm || !mmget_not_zero(mm))
1464 		goto out;
1465 
1466 	ret = -EINVAL;
1467 	/* file position must be aligned */
1468 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1469 		goto out_mm;
1470 
1471 	ret = 0;
1472 	if (!count)
1473 		goto out_mm;
1474 
1475 	/* do not disclose physical addresses: attack vector */
1476 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1477 
1478 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1479 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_KERNEL);
1480 	ret = -ENOMEM;
1481 	if (!pm.buffer)
1482 		goto out_mm;
1483 
1484 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1485 	pagemap_walk.pte_hole = pagemap_pte_hole;
1486 #ifdef CONFIG_HUGETLB_PAGE
1487 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1488 #endif
1489 	pagemap_walk.mm = mm;
1490 	pagemap_walk.private = &pm;
1491 
1492 	src = *ppos;
1493 	svpfn = src / PM_ENTRY_BYTES;
1494 	start_vaddr = svpfn << PAGE_SHIFT;
1495 	end_vaddr = mm->task_size;
1496 
1497 	/* watch out for wraparound */
1498 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1499 		start_vaddr = end_vaddr;
1500 
1501 	/*
1502 	 * The odds are that this will stop walking way
1503 	 * before end_vaddr, because the length of the
1504 	 * user buffer is tracked in "pm", and the walk
1505 	 * will stop when we hit the end of the buffer.
1506 	 */
1507 	ret = 0;
1508 	while (count && (start_vaddr < end_vaddr)) {
1509 		int len;
1510 		unsigned long end;
1511 
1512 		pm.pos = 0;
1513 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1514 		/* overflow ? */
1515 		if (end < start_vaddr || end > end_vaddr)
1516 			end = end_vaddr;
1517 		down_read(&mm->mmap_sem);
1518 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1519 		up_read(&mm->mmap_sem);
1520 		start_vaddr = end;
1521 
1522 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1523 		if (copy_to_user(buf, pm.buffer, len)) {
1524 			ret = -EFAULT;
1525 			goto out_free;
1526 		}
1527 		copied += len;
1528 		buf += len;
1529 		count -= len;
1530 	}
1531 	*ppos += copied;
1532 	if (!ret || ret == PM_END_OF_BUFFER)
1533 		ret = copied;
1534 
1535 out_free:
1536 	kfree(pm.buffer);
1537 out_mm:
1538 	mmput(mm);
1539 out:
1540 	return ret;
1541 }
1542 
1543 static int pagemap_open(struct inode *inode, struct file *file)
1544 {
1545 	struct mm_struct *mm;
1546 
1547 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1548 	if (IS_ERR(mm))
1549 		return PTR_ERR(mm);
1550 	file->private_data = mm;
1551 	return 0;
1552 }
1553 
1554 static int pagemap_release(struct inode *inode, struct file *file)
1555 {
1556 	struct mm_struct *mm = file->private_data;
1557 
1558 	if (mm)
1559 		mmdrop(mm);
1560 	return 0;
1561 }
1562 
1563 const struct file_operations proc_pagemap_operations = {
1564 	.llseek		= mem_lseek, /* borrow this */
1565 	.read		= pagemap_read,
1566 	.open		= pagemap_open,
1567 	.release	= pagemap_release,
1568 };
1569 #endif /* CONFIG_PROC_PAGE_MONITOR */
1570 
1571 #ifdef CONFIG_NUMA
1572 
1573 struct numa_maps {
1574 	unsigned long pages;
1575 	unsigned long anon;
1576 	unsigned long active;
1577 	unsigned long writeback;
1578 	unsigned long mapcount_max;
1579 	unsigned long dirty;
1580 	unsigned long swapcache;
1581 	unsigned long node[MAX_NUMNODES];
1582 };
1583 
1584 struct numa_maps_private {
1585 	struct proc_maps_private proc_maps;
1586 	struct numa_maps md;
1587 };
1588 
1589 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1590 			unsigned long nr_pages)
1591 {
1592 	int count = page_mapcount(page);
1593 
1594 	md->pages += nr_pages;
1595 	if (pte_dirty || PageDirty(page))
1596 		md->dirty += nr_pages;
1597 
1598 	if (PageSwapCache(page))
1599 		md->swapcache += nr_pages;
1600 
1601 	if (PageActive(page) || PageUnevictable(page))
1602 		md->active += nr_pages;
1603 
1604 	if (PageWriteback(page))
1605 		md->writeback += nr_pages;
1606 
1607 	if (PageAnon(page))
1608 		md->anon += nr_pages;
1609 
1610 	if (count > md->mapcount_max)
1611 		md->mapcount_max = count;
1612 
1613 	md->node[page_to_nid(page)] += nr_pages;
1614 }
1615 
1616 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1617 		unsigned long addr)
1618 {
1619 	struct page *page;
1620 	int nid;
1621 
1622 	if (!pte_present(pte))
1623 		return NULL;
1624 
1625 	page = vm_normal_page(vma, addr, pte);
1626 	if (!page)
1627 		return NULL;
1628 
1629 	if (PageReserved(page))
1630 		return NULL;
1631 
1632 	nid = page_to_nid(page);
1633 	if (!node_isset(nid, node_states[N_MEMORY]))
1634 		return NULL;
1635 
1636 	return page;
1637 }
1638 
1639 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1640 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1641 					      struct vm_area_struct *vma,
1642 					      unsigned long addr)
1643 {
1644 	struct page *page;
1645 	int nid;
1646 
1647 	if (!pmd_present(pmd))
1648 		return NULL;
1649 
1650 	page = vm_normal_page_pmd(vma, addr, pmd);
1651 	if (!page)
1652 		return NULL;
1653 
1654 	if (PageReserved(page))
1655 		return NULL;
1656 
1657 	nid = page_to_nid(page);
1658 	if (!node_isset(nid, node_states[N_MEMORY]))
1659 		return NULL;
1660 
1661 	return page;
1662 }
1663 #endif
1664 
1665 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1666 		unsigned long end, struct mm_walk *walk)
1667 {
1668 	struct numa_maps *md = walk->private;
1669 	struct vm_area_struct *vma = walk->vma;
1670 	spinlock_t *ptl;
1671 	pte_t *orig_pte;
1672 	pte_t *pte;
1673 
1674 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1675 	ptl = pmd_trans_huge_lock(pmd, vma);
1676 	if (ptl) {
1677 		struct page *page;
1678 
1679 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1680 		if (page)
1681 			gather_stats(page, md, pmd_dirty(*pmd),
1682 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1683 		spin_unlock(ptl);
1684 		return 0;
1685 	}
1686 
1687 	if (pmd_trans_unstable(pmd))
1688 		return 0;
1689 #endif
1690 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1691 	do {
1692 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1693 		if (!page)
1694 			continue;
1695 		gather_stats(page, md, pte_dirty(*pte), 1);
1696 
1697 	} while (pte++, addr += PAGE_SIZE, addr != end);
1698 	pte_unmap_unlock(orig_pte, ptl);
1699 	cond_resched();
1700 	return 0;
1701 }
1702 #ifdef CONFIG_HUGETLB_PAGE
1703 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1704 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1705 {
1706 	pte_t huge_pte = huge_ptep_get(pte);
1707 	struct numa_maps *md;
1708 	struct page *page;
1709 
1710 	if (!pte_present(huge_pte))
1711 		return 0;
1712 
1713 	page = pte_page(huge_pte);
1714 	if (!page)
1715 		return 0;
1716 
1717 	md = walk->private;
1718 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1719 	return 0;
1720 }
1721 
1722 #else
1723 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1724 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1725 {
1726 	return 0;
1727 }
1728 #endif
1729 
1730 /*
1731  * Display pages allocated per node and memory policy via /proc.
1732  */
1733 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1734 {
1735 	struct numa_maps_private *numa_priv = m->private;
1736 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1737 	struct vm_area_struct *vma = v;
1738 	struct numa_maps *md = &numa_priv->md;
1739 	struct file *file = vma->vm_file;
1740 	struct mm_struct *mm = vma->vm_mm;
1741 	struct mm_walk walk = {
1742 		.hugetlb_entry = gather_hugetlb_stats,
1743 		.pmd_entry = gather_pte_stats,
1744 		.private = md,
1745 		.mm = mm,
1746 	};
1747 	struct mempolicy *pol;
1748 	char buffer[64];
1749 	int nid;
1750 
1751 	if (!mm)
1752 		return 0;
1753 
1754 	/* Ensure we start with an empty set of numa_maps statistics. */
1755 	memset(md, 0, sizeof(*md));
1756 
1757 	pol = __get_vma_policy(vma, vma->vm_start);
1758 	if (pol) {
1759 		mpol_to_str(buffer, sizeof(buffer), pol);
1760 		mpol_cond_put(pol);
1761 	} else {
1762 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1763 	}
1764 
1765 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1766 
1767 	if (file) {
1768 		seq_puts(m, " file=");
1769 		seq_file_path(m, file, "\n\t= ");
1770 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1771 		seq_puts(m, " heap");
1772 	} else if (is_stack(vma)) {
1773 		seq_puts(m, " stack");
1774 	}
1775 
1776 	if (is_vm_hugetlb_page(vma))
1777 		seq_puts(m, " huge");
1778 
1779 	/* mmap_sem is held by m_start */
1780 	walk_page_vma(vma, &walk);
1781 
1782 	if (!md->pages)
1783 		goto out;
1784 
1785 	if (md->anon)
1786 		seq_printf(m, " anon=%lu", md->anon);
1787 
1788 	if (md->dirty)
1789 		seq_printf(m, " dirty=%lu", md->dirty);
1790 
1791 	if (md->pages != md->anon && md->pages != md->dirty)
1792 		seq_printf(m, " mapped=%lu", md->pages);
1793 
1794 	if (md->mapcount_max > 1)
1795 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1796 
1797 	if (md->swapcache)
1798 		seq_printf(m, " swapcache=%lu", md->swapcache);
1799 
1800 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1801 		seq_printf(m, " active=%lu", md->active);
1802 
1803 	if (md->writeback)
1804 		seq_printf(m, " writeback=%lu", md->writeback);
1805 
1806 	for_each_node_state(nid, N_MEMORY)
1807 		if (md->node[nid])
1808 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1809 
1810 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1811 out:
1812 	seq_putc(m, '\n');
1813 	m_cache_vma(m, vma);
1814 	return 0;
1815 }
1816 
1817 static int show_pid_numa_map(struct seq_file *m, void *v)
1818 {
1819 	return show_numa_map(m, v, 1);
1820 }
1821 
1822 static int show_tid_numa_map(struct seq_file *m, void *v)
1823 {
1824 	return show_numa_map(m, v, 0);
1825 }
1826 
1827 static const struct seq_operations proc_pid_numa_maps_op = {
1828 	.start  = m_start,
1829 	.next   = m_next,
1830 	.stop   = m_stop,
1831 	.show   = show_pid_numa_map,
1832 };
1833 
1834 static const struct seq_operations proc_tid_numa_maps_op = {
1835 	.start  = m_start,
1836 	.next   = m_next,
1837 	.stop   = m_stop,
1838 	.show   = show_tid_numa_map,
1839 };
1840 
1841 static int numa_maps_open(struct inode *inode, struct file *file,
1842 			  const struct seq_operations *ops)
1843 {
1844 	return proc_maps_open(inode, file, ops,
1845 				sizeof(struct numa_maps_private));
1846 }
1847 
1848 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1849 {
1850 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1851 }
1852 
1853 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1854 {
1855 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1856 }
1857 
1858 const struct file_operations proc_pid_numa_maps_operations = {
1859 	.open		= pid_numa_maps_open,
1860 	.read		= seq_read,
1861 	.llseek		= seq_lseek,
1862 	.release	= proc_map_release,
1863 };
1864 
1865 const struct file_operations proc_tid_numa_maps_operations = {
1866 	.open		= tid_numa_maps_open,
1867 	.read		= seq_read,
1868 	.llseek		= seq_lseek,
1869 	.release	= proc_map_release,
1870 };
1871 #endif /* CONFIG_NUMA */
1872