xref: /linux/fs/proc/task_mmu.c (revision fbd126f5a658b92c7f6af986a6d89cf5e5693268)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/pagewalk.h>
3 #include <linux/mm_inline.h>
4 #include <linux/hugetlb.h>
5 #include <linux/huge_mm.h>
6 #include <linux/mount.h>
7 #include <linux/ksm.h>
8 #include <linux/seq_file.h>
9 #include <linux/highmem.h>
10 #include <linux/ptrace.h>
11 #include <linux/slab.h>
12 #include <linux/pagemap.h>
13 #include <linux/mempolicy.h>
14 #include <linux/rmap.h>
15 #include <linux/swap.h>
16 #include <linux/sched/mm.h>
17 #include <linux/swapops.h>
18 #include <linux/mmu_notifier.h>
19 #include <linux/page_idle.h>
20 #include <linux/shmem_fs.h>
21 #include <linux/uaccess.h>
22 #include <linux/pkeys.h>
23 
24 #include <asm/elf.h>
25 #include <asm/tlb.h>
26 #include <asm/tlbflush.h>
27 #include "internal.h"
28 
29 #define SEQ_PUT_DEC(str, val) \
30 		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
31 void task_mem(struct seq_file *m, struct mm_struct *mm)
32 {
33 	unsigned long text, lib, swap, anon, file, shmem;
34 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
35 
36 	anon = get_mm_counter(mm, MM_ANONPAGES);
37 	file = get_mm_counter(mm, MM_FILEPAGES);
38 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
39 
40 	/*
41 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
42 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
43 	 * collector of these hiwater stats must therefore get total_vm
44 	 * and rss too, which will usually be the higher.  Barriers? not
45 	 * worth the effort, such snapshots can always be inconsistent.
46 	 */
47 	hiwater_vm = total_vm = mm->total_vm;
48 	if (hiwater_vm < mm->hiwater_vm)
49 		hiwater_vm = mm->hiwater_vm;
50 	hiwater_rss = total_rss = anon + file + shmem;
51 	if (hiwater_rss < mm->hiwater_rss)
52 		hiwater_rss = mm->hiwater_rss;
53 
54 	/* split executable areas between text and lib */
55 	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
56 	text = min(text, mm->exec_vm << PAGE_SHIFT);
57 	lib = (mm->exec_vm << PAGE_SHIFT) - text;
58 
59 	swap = get_mm_counter(mm, MM_SWAPENTS);
60 	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
61 	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
62 	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
63 	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
64 	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
65 	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
66 	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
67 	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
68 	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
69 	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
70 	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
71 	seq_put_decimal_ull_width(m,
72 		    " kB\nVmExe:\t", text >> 10, 8);
73 	seq_put_decimal_ull_width(m,
74 		    " kB\nVmLib:\t", lib >> 10, 8);
75 	seq_put_decimal_ull_width(m,
76 		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
77 	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
78 	seq_puts(m, " kB\n");
79 	hugetlb_report_usage(m, mm);
80 }
81 #undef SEQ_PUT_DEC
82 
83 unsigned long task_vsize(struct mm_struct *mm)
84 {
85 	return PAGE_SIZE * mm->total_vm;
86 }
87 
88 unsigned long task_statm(struct mm_struct *mm,
89 			 unsigned long *shared, unsigned long *text,
90 			 unsigned long *data, unsigned long *resident)
91 {
92 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
93 			get_mm_counter(mm, MM_SHMEMPAGES);
94 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
95 								>> PAGE_SHIFT;
96 	*data = mm->data_vm + mm->stack_vm;
97 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
98 	return mm->total_vm;
99 }
100 
101 #ifdef CONFIG_NUMA
102 /*
103  * Save get_task_policy() for show_numa_map().
104  */
105 static void hold_task_mempolicy(struct proc_maps_private *priv)
106 {
107 	struct task_struct *task = priv->task;
108 
109 	task_lock(task);
110 	priv->task_mempolicy = get_task_policy(task);
111 	mpol_get(priv->task_mempolicy);
112 	task_unlock(task);
113 }
114 static void release_task_mempolicy(struct proc_maps_private *priv)
115 {
116 	mpol_put(priv->task_mempolicy);
117 }
118 #else
119 static void hold_task_mempolicy(struct proc_maps_private *priv)
120 {
121 }
122 static void release_task_mempolicy(struct proc_maps_private *priv)
123 {
124 }
125 #endif
126 
127 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
128 						loff_t *ppos)
129 {
130 	struct vm_area_struct *vma = vma_next(&priv->iter);
131 
132 	if (vma) {
133 		*ppos = vma->vm_start;
134 	} else {
135 		*ppos = -2UL;
136 		vma = get_gate_vma(priv->mm);
137 	}
138 
139 	return vma;
140 }
141 
142 static void *m_start(struct seq_file *m, loff_t *ppos)
143 {
144 	struct proc_maps_private *priv = m->private;
145 	unsigned long last_addr = *ppos;
146 	struct mm_struct *mm;
147 
148 	/* See m_next(). Zero at the start or after lseek. */
149 	if (last_addr == -1UL)
150 		return NULL;
151 
152 	priv->task = get_proc_task(priv->inode);
153 	if (!priv->task)
154 		return ERR_PTR(-ESRCH);
155 
156 	mm = priv->mm;
157 	if (!mm || !mmget_not_zero(mm)) {
158 		put_task_struct(priv->task);
159 		priv->task = NULL;
160 		return NULL;
161 	}
162 
163 	if (mmap_read_lock_killable(mm)) {
164 		mmput(mm);
165 		put_task_struct(priv->task);
166 		priv->task = NULL;
167 		return ERR_PTR(-EINTR);
168 	}
169 
170 	vma_iter_init(&priv->iter, mm, last_addr);
171 	hold_task_mempolicy(priv);
172 	if (last_addr == -2UL)
173 		return get_gate_vma(mm);
174 
175 	return proc_get_vma(priv, ppos);
176 }
177 
178 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
179 {
180 	if (*ppos == -2UL) {
181 		*ppos = -1UL;
182 		return NULL;
183 	}
184 	return proc_get_vma(m->private, ppos);
185 }
186 
187 static void m_stop(struct seq_file *m, void *v)
188 {
189 	struct proc_maps_private *priv = m->private;
190 	struct mm_struct *mm = priv->mm;
191 
192 	if (!priv->task)
193 		return;
194 
195 	release_task_mempolicy(priv);
196 	mmap_read_unlock(mm);
197 	mmput(mm);
198 	put_task_struct(priv->task);
199 	priv->task = NULL;
200 }
201 
202 static int proc_maps_open(struct inode *inode, struct file *file,
203 			const struct seq_operations *ops, int psize)
204 {
205 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
206 
207 	if (!priv)
208 		return -ENOMEM;
209 
210 	priv->inode = inode;
211 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
212 	if (IS_ERR(priv->mm)) {
213 		int err = PTR_ERR(priv->mm);
214 
215 		seq_release_private(inode, file);
216 		return err;
217 	}
218 
219 	return 0;
220 }
221 
222 static int proc_map_release(struct inode *inode, struct file *file)
223 {
224 	struct seq_file *seq = file->private_data;
225 	struct proc_maps_private *priv = seq->private;
226 
227 	if (priv->mm)
228 		mmdrop(priv->mm);
229 
230 	return seq_release_private(inode, file);
231 }
232 
233 static int do_maps_open(struct inode *inode, struct file *file,
234 			const struct seq_operations *ops)
235 {
236 	return proc_maps_open(inode, file, ops,
237 				sizeof(struct proc_maps_private));
238 }
239 
240 static void show_vma_header_prefix(struct seq_file *m,
241 				   unsigned long start, unsigned long end,
242 				   vm_flags_t flags, unsigned long long pgoff,
243 				   dev_t dev, unsigned long ino)
244 {
245 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
246 	seq_put_hex_ll(m, NULL, start, 8);
247 	seq_put_hex_ll(m, "-", end, 8);
248 	seq_putc(m, ' ');
249 	seq_putc(m, flags & VM_READ ? 'r' : '-');
250 	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
251 	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
252 	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
253 	seq_put_hex_ll(m, " ", pgoff, 8);
254 	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
255 	seq_put_hex_ll(m, ":", MINOR(dev), 2);
256 	seq_put_decimal_ull(m, " ", ino);
257 	seq_putc(m, ' ');
258 }
259 
260 static void
261 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
262 {
263 	struct anon_vma_name *anon_name = NULL;
264 	struct mm_struct *mm = vma->vm_mm;
265 	struct file *file = vma->vm_file;
266 	vm_flags_t flags = vma->vm_flags;
267 	unsigned long ino = 0;
268 	unsigned long long pgoff = 0;
269 	unsigned long start, end;
270 	dev_t dev = 0;
271 	const char *name = NULL;
272 
273 	if (file) {
274 		struct inode *inode = file_inode(vma->vm_file);
275 		dev = inode->i_sb->s_dev;
276 		ino = inode->i_ino;
277 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
278 	}
279 
280 	start = vma->vm_start;
281 	end = vma->vm_end;
282 	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
283 	if (mm)
284 		anon_name = anon_vma_name(vma);
285 
286 	/*
287 	 * Print the dentry name for named mappings, and a
288 	 * special [heap] marker for the heap:
289 	 */
290 	if (file) {
291 		seq_pad(m, ' ');
292 		/*
293 		 * If user named this anon shared memory via
294 		 * prctl(PR_SET_VMA ..., use the provided name.
295 		 */
296 		if (anon_name)
297 			seq_printf(m, "[anon_shmem:%s]", anon_name->name);
298 		else
299 			seq_file_path(m, file, "\n");
300 		goto done;
301 	}
302 
303 	if (vma->vm_ops && vma->vm_ops->name) {
304 		name = vma->vm_ops->name(vma);
305 		if (name)
306 			goto done;
307 	}
308 
309 	name = arch_vma_name(vma);
310 	if (!name) {
311 		if (!mm) {
312 			name = "[vdso]";
313 			goto done;
314 		}
315 
316 		if (vma_is_initial_heap(vma)) {
317 			name = "[heap]";
318 			goto done;
319 		}
320 
321 		if (vma_is_initial_stack(vma)) {
322 			name = "[stack]";
323 			goto done;
324 		}
325 
326 		if (anon_name) {
327 			seq_pad(m, ' ');
328 			seq_printf(m, "[anon:%s]", anon_name->name);
329 		}
330 	}
331 
332 done:
333 	if (name) {
334 		seq_pad(m, ' ');
335 		seq_puts(m, name);
336 	}
337 	seq_putc(m, '\n');
338 }
339 
340 static int show_map(struct seq_file *m, void *v)
341 {
342 	show_map_vma(m, v);
343 	return 0;
344 }
345 
346 static const struct seq_operations proc_pid_maps_op = {
347 	.start	= m_start,
348 	.next	= m_next,
349 	.stop	= m_stop,
350 	.show	= show_map
351 };
352 
353 static int pid_maps_open(struct inode *inode, struct file *file)
354 {
355 	return do_maps_open(inode, file, &proc_pid_maps_op);
356 }
357 
358 const struct file_operations proc_pid_maps_operations = {
359 	.open		= pid_maps_open,
360 	.read		= seq_read,
361 	.llseek		= seq_lseek,
362 	.release	= proc_map_release,
363 };
364 
365 /*
366  * Proportional Set Size(PSS): my share of RSS.
367  *
368  * PSS of a process is the count of pages it has in memory, where each
369  * page is divided by the number of processes sharing it.  So if a
370  * process has 1000 pages all to itself, and 1000 shared with one other
371  * process, its PSS will be 1500.
372  *
373  * To keep (accumulated) division errors low, we adopt a 64bit
374  * fixed-point pss counter to minimize division errors. So (pss >>
375  * PSS_SHIFT) would be the real byte count.
376  *
377  * A shift of 12 before division means (assuming 4K page size):
378  * 	- 1M 3-user-pages add up to 8KB errors;
379  * 	- supports mapcount up to 2^24, or 16M;
380  * 	- supports PSS up to 2^52 bytes, or 4PB.
381  */
382 #define PSS_SHIFT 12
383 
384 #ifdef CONFIG_PROC_PAGE_MONITOR
385 struct mem_size_stats {
386 	unsigned long resident;
387 	unsigned long shared_clean;
388 	unsigned long shared_dirty;
389 	unsigned long private_clean;
390 	unsigned long private_dirty;
391 	unsigned long referenced;
392 	unsigned long anonymous;
393 	unsigned long lazyfree;
394 	unsigned long anonymous_thp;
395 	unsigned long shmem_thp;
396 	unsigned long file_thp;
397 	unsigned long swap;
398 	unsigned long shared_hugetlb;
399 	unsigned long private_hugetlb;
400 	unsigned long ksm;
401 	u64 pss;
402 	u64 pss_anon;
403 	u64 pss_file;
404 	u64 pss_shmem;
405 	u64 pss_dirty;
406 	u64 pss_locked;
407 	u64 swap_pss;
408 };
409 
410 static void smaps_page_accumulate(struct mem_size_stats *mss,
411 		struct page *page, unsigned long size, unsigned long pss,
412 		bool dirty, bool locked, bool private)
413 {
414 	mss->pss += pss;
415 
416 	if (PageAnon(page))
417 		mss->pss_anon += pss;
418 	else if (PageSwapBacked(page))
419 		mss->pss_shmem += pss;
420 	else
421 		mss->pss_file += pss;
422 
423 	if (locked)
424 		mss->pss_locked += pss;
425 
426 	if (dirty || PageDirty(page)) {
427 		mss->pss_dirty += pss;
428 		if (private)
429 			mss->private_dirty += size;
430 		else
431 			mss->shared_dirty += size;
432 	} else {
433 		if (private)
434 			mss->private_clean += size;
435 		else
436 			mss->shared_clean += size;
437 	}
438 }
439 
440 static void smaps_account(struct mem_size_stats *mss, struct page *page,
441 		bool compound, bool young, bool dirty, bool locked,
442 		bool migration)
443 {
444 	int i, nr = compound ? compound_nr(page) : 1;
445 	unsigned long size = nr * PAGE_SIZE;
446 
447 	/*
448 	 * First accumulate quantities that depend only on |size| and the type
449 	 * of the compound page.
450 	 */
451 	if (PageAnon(page)) {
452 		mss->anonymous += size;
453 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
454 			mss->lazyfree += size;
455 	}
456 
457 	if (PageKsm(page))
458 		mss->ksm += size;
459 
460 	mss->resident += size;
461 	/* Accumulate the size in pages that have been accessed. */
462 	if (young || page_is_young(page) || PageReferenced(page))
463 		mss->referenced += size;
464 
465 	/*
466 	 * Then accumulate quantities that may depend on sharing, or that may
467 	 * differ page-by-page.
468 	 *
469 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
470 	 * If any subpage of the compound page mapped with PTE it would elevate
471 	 * page_count().
472 	 *
473 	 * The page_mapcount() is called to get a snapshot of the mapcount.
474 	 * Without holding the page lock this snapshot can be slightly wrong as
475 	 * we cannot always read the mapcount atomically.  It is not safe to
476 	 * call page_mapcount() even with PTL held if the page is not mapped,
477 	 * especially for migration entries.  Treat regular migration entries
478 	 * as mapcount == 1.
479 	 */
480 	if ((page_count(page) == 1) || migration) {
481 		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
482 			locked, true);
483 		return;
484 	}
485 	for (i = 0; i < nr; i++, page++) {
486 		int mapcount = page_mapcount(page);
487 		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
488 		if (mapcount >= 2)
489 			pss /= mapcount;
490 		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
491 				      mapcount < 2);
492 	}
493 }
494 
495 #ifdef CONFIG_SHMEM
496 static int smaps_pte_hole(unsigned long addr, unsigned long end,
497 			  __always_unused int depth, struct mm_walk *walk)
498 {
499 	struct mem_size_stats *mss = walk->private;
500 	struct vm_area_struct *vma = walk->vma;
501 
502 	mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
503 					      linear_page_index(vma, addr),
504 					      linear_page_index(vma, end));
505 
506 	return 0;
507 }
508 #else
509 #define smaps_pte_hole		NULL
510 #endif /* CONFIG_SHMEM */
511 
512 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
513 {
514 #ifdef CONFIG_SHMEM
515 	if (walk->ops->pte_hole) {
516 		/* depth is not used */
517 		smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
518 	}
519 #endif
520 }
521 
522 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
523 		struct mm_walk *walk)
524 {
525 	struct mem_size_stats *mss = walk->private;
526 	struct vm_area_struct *vma = walk->vma;
527 	bool locked = !!(vma->vm_flags & VM_LOCKED);
528 	struct page *page = NULL;
529 	bool migration = false, young = false, dirty = false;
530 	pte_t ptent = ptep_get(pte);
531 
532 	if (pte_present(ptent)) {
533 		page = vm_normal_page(vma, addr, ptent);
534 		young = pte_young(ptent);
535 		dirty = pte_dirty(ptent);
536 	} else if (is_swap_pte(ptent)) {
537 		swp_entry_t swpent = pte_to_swp_entry(ptent);
538 
539 		if (!non_swap_entry(swpent)) {
540 			int mapcount;
541 
542 			mss->swap += PAGE_SIZE;
543 			mapcount = swp_swapcount(swpent);
544 			if (mapcount >= 2) {
545 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
546 
547 				do_div(pss_delta, mapcount);
548 				mss->swap_pss += pss_delta;
549 			} else {
550 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
551 			}
552 		} else if (is_pfn_swap_entry(swpent)) {
553 			if (is_migration_entry(swpent))
554 				migration = true;
555 			page = pfn_swap_entry_to_page(swpent);
556 		}
557 	} else {
558 		smaps_pte_hole_lookup(addr, walk);
559 		return;
560 	}
561 
562 	if (!page)
563 		return;
564 
565 	smaps_account(mss, page, false, young, dirty, locked, migration);
566 }
567 
568 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
569 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
570 		struct mm_walk *walk)
571 {
572 	struct mem_size_stats *mss = walk->private;
573 	struct vm_area_struct *vma = walk->vma;
574 	bool locked = !!(vma->vm_flags & VM_LOCKED);
575 	struct page *page = NULL;
576 	bool migration = false;
577 
578 	if (pmd_present(*pmd)) {
579 		page = vm_normal_page_pmd(vma, addr, *pmd);
580 	} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
581 		swp_entry_t entry = pmd_to_swp_entry(*pmd);
582 
583 		if (is_migration_entry(entry)) {
584 			migration = true;
585 			page = pfn_swap_entry_to_page(entry);
586 		}
587 	}
588 	if (IS_ERR_OR_NULL(page))
589 		return;
590 	if (PageAnon(page))
591 		mss->anonymous_thp += HPAGE_PMD_SIZE;
592 	else if (PageSwapBacked(page))
593 		mss->shmem_thp += HPAGE_PMD_SIZE;
594 	else if (is_zone_device_page(page))
595 		/* pass */;
596 	else
597 		mss->file_thp += HPAGE_PMD_SIZE;
598 
599 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
600 		      locked, migration);
601 }
602 #else
603 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
604 		struct mm_walk *walk)
605 {
606 }
607 #endif
608 
609 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
610 			   struct mm_walk *walk)
611 {
612 	struct vm_area_struct *vma = walk->vma;
613 	pte_t *pte;
614 	spinlock_t *ptl;
615 
616 	ptl = pmd_trans_huge_lock(pmd, vma);
617 	if (ptl) {
618 		smaps_pmd_entry(pmd, addr, walk);
619 		spin_unlock(ptl);
620 		goto out;
621 	}
622 
623 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
624 	if (!pte) {
625 		walk->action = ACTION_AGAIN;
626 		return 0;
627 	}
628 	for (; addr != end; pte++, addr += PAGE_SIZE)
629 		smaps_pte_entry(pte, addr, walk);
630 	pte_unmap_unlock(pte - 1, ptl);
631 out:
632 	cond_resched();
633 	return 0;
634 }
635 
636 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
637 {
638 	/*
639 	 * Don't forget to update Documentation/ on changes.
640 	 */
641 	static const char mnemonics[BITS_PER_LONG][2] = {
642 		/*
643 		 * In case if we meet a flag we don't know about.
644 		 */
645 		[0 ... (BITS_PER_LONG-1)] = "??",
646 
647 		[ilog2(VM_READ)]	= "rd",
648 		[ilog2(VM_WRITE)]	= "wr",
649 		[ilog2(VM_EXEC)]	= "ex",
650 		[ilog2(VM_SHARED)]	= "sh",
651 		[ilog2(VM_MAYREAD)]	= "mr",
652 		[ilog2(VM_MAYWRITE)]	= "mw",
653 		[ilog2(VM_MAYEXEC)]	= "me",
654 		[ilog2(VM_MAYSHARE)]	= "ms",
655 		[ilog2(VM_GROWSDOWN)]	= "gd",
656 		[ilog2(VM_PFNMAP)]	= "pf",
657 		[ilog2(VM_LOCKED)]	= "lo",
658 		[ilog2(VM_IO)]		= "io",
659 		[ilog2(VM_SEQ_READ)]	= "sr",
660 		[ilog2(VM_RAND_READ)]	= "rr",
661 		[ilog2(VM_DONTCOPY)]	= "dc",
662 		[ilog2(VM_DONTEXPAND)]	= "de",
663 		[ilog2(VM_LOCKONFAULT)]	= "lf",
664 		[ilog2(VM_ACCOUNT)]	= "ac",
665 		[ilog2(VM_NORESERVE)]	= "nr",
666 		[ilog2(VM_HUGETLB)]	= "ht",
667 		[ilog2(VM_SYNC)]	= "sf",
668 		[ilog2(VM_ARCH_1)]	= "ar",
669 		[ilog2(VM_WIPEONFORK)]	= "wf",
670 		[ilog2(VM_DONTDUMP)]	= "dd",
671 #ifdef CONFIG_ARM64_BTI
672 		[ilog2(VM_ARM64_BTI)]	= "bt",
673 #endif
674 #ifdef CONFIG_MEM_SOFT_DIRTY
675 		[ilog2(VM_SOFTDIRTY)]	= "sd",
676 #endif
677 		[ilog2(VM_MIXEDMAP)]	= "mm",
678 		[ilog2(VM_HUGEPAGE)]	= "hg",
679 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
680 		[ilog2(VM_MERGEABLE)]	= "mg",
681 		[ilog2(VM_UFFD_MISSING)]= "um",
682 		[ilog2(VM_UFFD_WP)]	= "uw",
683 #ifdef CONFIG_ARM64_MTE
684 		[ilog2(VM_MTE)]		= "mt",
685 		[ilog2(VM_MTE_ALLOWED)]	= "",
686 #endif
687 #ifdef CONFIG_ARCH_HAS_PKEYS
688 		/* These come out via ProtectionKey: */
689 		[ilog2(VM_PKEY_BIT0)]	= "",
690 		[ilog2(VM_PKEY_BIT1)]	= "",
691 		[ilog2(VM_PKEY_BIT2)]	= "",
692 		[ilog2(VM_PKEY_BIT3)]	= "",
693 #if VM_PKEY_BIT4
694 		[ilog2(VM_PKEY_BIT4)]	= "",
695 #endif
696 #endif /* CONFIG_ARCH_HAS_PKEYS */
697 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
698 		[ilog2(VM_UFFD_MINOR)]	= "ui",
699 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
700 #ifdef CONFIG_X86_USER_SHADOW_STACK
701 		[ilog2(VM_SHADOW_STACK)] = "ss",
702 #endif
703 	};
704 	size_t i;
705 
706 	seq_puts(m, "VmFlags: ");
707 	for (i = 0; i < BITS_PER_LONG; i++) {
708 		if (!mnemonics[i][0])
709 			continue;
710 		if (vma->vm_flags & (1UL << i)) {
711 			seq_putc(m, mnemonics[i][0]);
712 			seq_putc(m, mnemonics[i][1]);
713 			seq_putc(m, ' ');
714 		}
715 	}
716 	seq_putc(m, '\n');
717 }
718 
719 #ifdef CONFIG_HUGETLB_PAGE
720 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
721 				 unsigned long addr, unsigned long end,
722 				 struct mm_walk *walk)
723 {
724 	struct mem_size_stats *mss = walk->private;
725 	struct vm_area_struct *vma = walk->vma;
726 	struct page *page = NULL;
727 	pte_t ptent = ptep_get(pte);
728 
729 	if (pte_present(ptent)) {
730 		page = vm_normal_page(vma, addr, ptent);
731 	} else if (is_swap_pte(ptent)) {
732 		swp_entry_t swpent = pte_to_swp_entry(ptent);
733 
734 		if (is_pfn_swap_entry(swpent))
735 			page = pfn_swap_entry_to_page(swpent);
736 	}
737 	if (page) {
738 		if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
739 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
740 		else
741 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
742 	}
743 	return 0;
744 }
745 #else
746 #define smaps_hugetlb_range	NULL
747 #endif /* HUGETLB_PAGE */
748 
749 static const struct mm_walk_ops smaps_walk_ops = {
750 	.pmd_entry		= smaps_pte_range,
751 	.hugetlb_entry		= smaps_hugetlb_range,
752 	.walk_lock		= PGWALK_RDLOCK,
753 };
754 
755 static const struct mm_walk_ops smaps_shmem_walk_ops = {
756 	.pmd_entry		= smaps_pte_range,
757 	.hugetlb_entry		= smaps_hugetlb_range,
758 	.pte_hole		= smaps_pte_hole,
759 	.walk_lock		= PGWALK_RDLOCK,
760 };
761 
762 /*
763  * Gather mem stats from @vma with the indicated beginning
764  * address @start, and keep them in @mss.
765  *
766  * Use vm_start of @vma as the beginning address if @start is 0.
767  */
768 static void smap_gather_stats(struct vm_area_struct *vma,
769 		struct mem_size_stats *mss, unsigned long start)
770 {
771 	const struct mm_walk_ops *ops = &smaps_walk_ops;
772 
773 	/* Invalid start */
774 	if (start >= vma->vm_end)
775 		return;
776 
777 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
778 		/*
779 		 * For shared or readonly shmem mappings we know that all
780 		 * swapped out pages belong to the shmem object, and we can
781 		 * obtain the swap value much more efficiently. For private
782 		 * writable mappings, we might have COW pages that are
783 		 * not affected by the parent swapped out pages of the shmem
784 		 * object, so we have to distinguish them during the page walk.
785 		 * Unless we know that the shmem object (or the part mapped by
786 		 * our VMA) has no swapped out pages at all.
787 		 */
788 		unsigned long shmem_swapped = shmem_swap_usage(vma);
789 
790 		if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
791 					!(vma->vm_flags & VM_WRITE))) {
792 			mss->swap += shmem_swapped;
793 		} else {
794 			ops = &smaps_shmem_walk_ops;
795 		}
796 	}
797 
798 	/* mmap_lock is held in m_start */
799 	if (!start)
800 		walk_page_vma(vma, ops, mss);
801 	else
802 		walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
803 }
804 
805 #define SEQ_PUT_DEC(str, val) \
806 		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
807 
808 /* Show the contents common for smaps and smaps_rollup */
809 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
810 	bool rollup_mode)
811 {
812 	SEQ_PUT_DEC("Rss:            ", mss->resident);
813 	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
814 	SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> PSS_SHIFT);
815 	if (rollup_mode) {
816 		/*
817 		 * These are meaningful only for smaps_rollup, otherwise two of
818 		 * them are zero, and the other one is the same as Pss.
819 		 */
820 		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
821 			mss->pss_anon >> PSS_SHIFT);
822 		SEQ_PUT_DEC(" kB\nPss_File:       ",
823 			mss->pss_file >> PSS_SHIFT);
824 		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
825 			mss->pss_shmem >> PSS_SHIFT);
826 	}
827 	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
828 	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
829 	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
830 	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
831 	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
832 	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
833 	SEQ_PUT_DEC(" kB\nKSM:            ", mss->ksm);
834 	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
835 	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
836 	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
837 	SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
838 	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
839 	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
840 				  mss->private_hugetlb >> 10, 7);
841 	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
842 	SEQ_PUT_DEC(" kB\nSwapPss:        ",
843 					mss->swap_pss >> PSS_SHIFT);
844 	SEQ_PUT_DEC(" kB\nLocked:         ",
845 					mss->pss_locked >> PSS_SHIFT);
846 	seq_puts(m, " kB\n");
847 }
848 
849 static int show_smap(struct seq_file *m, void *v)
850 {
851 	struct vm_area_struct *vma = v;
852 	struct mem_size_stats mss = {};
853 
854 	smap_gather_stats(vma, &mss, 0);
855 
856 	show_map_vma(m, vma);
857 
858 	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
859 	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
860 	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
861 	seq_puts(m, " kB\n");
862 
863 	__show_smap(m, &mss, false);
864 
865 	seq_printf(m, "THPeligible:    %8u\n",
866 		   hugepage_vma_check(vma, vma->vm_flags, true, false, true));
867 
868 	if (arch_pkeys_enabled())
869 		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
870 	show_smap_vma_flags(m, vma);
871 
872 	return 0;
873 }
874 
875 static int show_smaps_rollup(struct seq_file *m, void *v)
876 {
877 	struct proc_maps_private *priv = m->private;
878 	struct mem_size_stats mss = {};
879 	struct mm_struct *mm = priv->mm;
880 	struct vm_area_struct *vma;
881 	unsigned long vma_start = 0, last_vma_end = 0;
882 	int ret = 0;
883 	VMA_ITERATOR(vmi, mm, 0);
884 
885 	priv->task = get_proc_task(priv->inode);
886 	if (!priv->task)
887 		return -ESRCH;
888 
889 	if (!mm || !mmget_not_zero(mm)) {
890 		ret = -ESRCH;
891 		goto out_put_task;
892 	}
893 
894 	ret = mmap_read_lock_killable(mm);
895 	if (ret)
896 		goto out_put_mm;
897 
898 	hold_task_mempolicy(priv);
899 	vma = vma_next(&vmi);
900 
901 	if (unlikely(!vma))
902 		goto empty_set;
903 
904 	vma_start = vma->vm_start;
905 	do {
906 		smap_gather_stats(vma, &mss, 0);
907 		last_vma_end = vma->vm_end;
908 
909 		/*
910 		 * Release mmap_lock temporarily if someone wants to
911 		 * access it for write request.
912 		 */
913 		if (mmap_lock_is_contended(mm)) {
914 			vma_iter_invalidate(&vmi);
915 			mmap_read_unlock(mm);
916 			ret = mmap_read_lock_killable(mm);
917 			if (ret) {
918 				release_task_mempolicy(priv);
919 				goto out_put_mm;
920 			}
921 
922 			/*
923 			 * After dropping the lock, there are four cases to
924 			 * consider. See the following example for explanation.
925 			 *
926 			 *   +------+------+-----------+
927 			 *   | VMA1 | VMA2 | VMA3      |
928 			 *   +------+------+-----------+
929 			 *   |      |      |           |
930 			 *  4k     8k     16k         400k
931 			 *
932 			 * Suppose we drop the lock after reading VMA2 due to
933 			 * contention, then we get:
934 			 *
935 			 *	last_vma_end = 16k
936 			 *
937 			 * 1) VMA2 is freed, but VMA3 exists:
938 			 *
939 			 *    vma_next(vmi) will return VMA3.
940 			 *    In this case, just continue from VMA3.
941 			 *
942 			 * 2) VMA2 still exists:
943 			 *
944 			 *    vma_next(vmi) will return VMA3.
945 			 *    In this case, just continue from VMA3.
946 			 *
947 			 * 3) No more VMAs can be found:
948 			 *
949 			 *    vma_next(vmi) will return NULL.
950 			 *    No more things to do, just break.
951 			 *
952 			 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
953 			 *
954 			 *    vma_next(vmi) will return VMA' whose range
955 			 *    contains last_vma_end.
956 			 *    Iterate VMA' from last_vma_end.
957 			 */
958 			vma = vma_next(&vmi);
959 			/* Case 3 above */
960 			if (!vma)
961 				break;
962 
963 			/* Case 1 and 2 above */
964 			if (vma->vm_start >= last_vma_end)
965 				continue;
966 
967 			/* Case 4 above */
968 			if (vma->vm_end > last_vma_end)
969 				smap_gather_stats(vma, &mss, last_vma_end);
970 		}
971 	} for_each_vma(vmi, vma);
972 
973 empty_set:
974 	show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
975 	seq_pad(m, ' ');
976 	seq_puts(m, "[rollup]\n");
977 
978 	__show_smap(m, &mss, true);
979 
980 	release_task_mempolicy(priv);
981 	mmap_read_unlock(mm);
982 
983 out_put_mm:
984 	mmput(mm);
985 out_put_task:
986 	put_task_struct(priv->task);
987 	priv->task = NULL;
988 
989 	return ret;
990 }
991 #undef SEQ_PUT_DEC
992 
993 static const struct seq_operations proc_pid_smaps_op = {
994 	.start	= m_start,
995 	.next	= m_next,
996 	.stop	= m_stop,
997 	.show	= show_smap
998 };
999 
1000 static int pid_smaps_open(struct inode *inode, struct file *file)
1001 {
1002 	return do_maps_open(inode, file, &proc_pid_smaps_op);
1003 }
1004 
1005 static int smaps_rollup_open(struct inode *inode, struct file *file)
1006 {
1007 	int ret;
1008 	struct proc_maps_private *priv;
1009 
1010 	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1011 	if (!priv)
1012 		return -ENOMEM;
1013 
1014 	ret = single_open(file, show_smaps_rollup, priv);
1015 	if (ret)
1016 		goto out_free;
1017 
1018 	priv->inode = inode;
1019 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1020 	if (IS_ERR(priv->mm)) {
1021 		ret = PTR_ERR(priv->mm);
1022 
1023 		single_release(inode, file);
1024 		goto out_free;
1025 	}
1026 
1027 	return 0;
1028 
1029 out_free:
1030 	kfree(priv);
1031 	return ret;
1032 }
1033 
1034 static int smaps_rollup_release(struct inode *inode, struct file *file)
1035 {
1036 	struct seq_file *seq = file->private_data;
1037 	struct proc_maps_private *priv = seq->private;
1038 
1039 	if (priv->mm)
1040 		mmdrop(priv->mm);
1041 
1042 	kfree(priv);
1043 	return single_release(inode, file);
1044 }
1045 
1046 const struct file_operations proc_pid_smaps_operations = {
1047 	.open		= pid_smaps_open,
1048 	.read		= seq_read,
1049 	.llseek		= seq_lseek,
1050 	.release	= proc_map_release,
1051 };
1052 
1053 const struct file_operations proc_pid_smaps_rollup_operations = {
1054 	.open		= smaps_rollup_open,
1055 	.read		= seq_read,
1056 	.llseek		= seq_lseek,
1057 	.release	= smaps_rollup_release,
1058 };
1059 
1060 enum clear_refs_types {
1061 	CLEAR_REFS_ALL = 1,
1062 	CLEAR_REFS_ANON,
1063 	CLEAR_REFS_MAPPED,
1064 	CLEAR_REFS_SOFT_DIRTY,
1065 	CLEAR_REFS_MM_HIWATER_RSS,
1066 	CLEAR_REFS_LAST,
1067 };
1068 
1069 struct clear_refs_private {
1070 	enum clear_refs_types type;
1071 };
1072 
1073 #ifdef CONFIG_MEM_SOFT_DIRTY
1074 
1075 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1076 {
1077 	struct page *page;
1078 
1079 	if (!pte_write(pte))
1080 		return false;
1081 	if (!is_cow_mapping(vma->vm_flags))
1082 		return false;
1083 	if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1084 		return false;
1085 	page = vm_normal_page(vma, addr, pte);
1086 	if (!page)
1087 		return false;
1088 	return page_maybe_dma_pinned(page);
1089 }
1090 
1091 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1092 		unsigned long addr, pte_t *pte)
1093 {
1094 	/*
1095 	 * The soft-dirty tracker uses #PF-s to catch writes
1096 	 * to pages, so write-protect the pte as well. See the
1097 	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
1098 	 * of how soft-dirty works.
1099 	 */
1100 	pte_t ptent = ptep_get(pte);
1101 
1102 	if (pte_present(ptent)) {
1103 		pte_t old_pte;
1104 
1105 		if (pte_is_pinned(vma, addr, ptent))
1106 			return;
1107 		old_pte = ptep_modify_prot_start(vma, addr, pte);
1108 		ptent = pte_wrprotect(old_pte);
1109 		ptent = pte_clear_soft_dirty(ptent);
1110 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1111 	} else if (is_swap_pte(ptent)) {
1112 		ptent = pte_swp_clear_soft_dirty(ptent);
1113 		set_pte_at(vma->vm_mm, addr, pte, ptent);
1114 	}
1115 }
1116 #else
1117 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1118 		unsigned long addr, pte_t *pte)
1119 {
1120 }
1121 #endif
1122 
1123 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1124 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1125 		unsigned long addr, pmd_t *pmdp)
1126 {
1127 	pmd_t old, pmd = *pmdp;
1128 
1129 	if (pmd_present(pmd)) {
1130 		/* See comment in change_huge_pmd() */
1131 		old = pmdp_invalidate(vma, addr, pmdp);
1132 		if (pmd_dirty(old))
1133 			pmd = pmd_mkdirty(pmd);
1134 		if (pmd_young(old))
1135 			pmd = pmd_mkyoung(pmd);
1136 
1137 		pmd = pmd_wrprotect(pmd);
1138 		pmd = pmd_clear_soft_dirty(pmd);
1139 
1140 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1141 	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1142 		pmd = pmd_swp_clear_soft_dirty(pmd);
1143 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1144 	}
1145 }
1146 #else
1147 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1148 		unsigned long addr, pmd_t *pmdp)
1149 {
1150 }
1151 #endif
1152 
1153 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1154 				unsigned long end, struct mm_walk *walk)
1155 {
1156 	struct clear_refs_private *cp = walk->private;
1157 	struct vm_area_struct *vma = walk->vma;
1158 	pte_t *pte, ptent;
1159 	spinlock_t *ptl;
1160 	struct page *page;
1161 
1162 	ptl = pmd_trans_huge_lock(pmd, vma);
1163 	if (ptl) {
1164 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1165 			clear_soft_dirty_pmd(vma, addr, pmd);
1166 			goto out;
1167 		}
1168 
1169 		if (!pmd_present(*pmd))
1170 			goto out;
1171 
1172 		page = pmd_page(*pmd);
1173 
1174 		/* Clear accessed and referenced bits. */
1175 		pmdp_test_and_clear_young(vma, addr, pmd);
1176 		test_and_clear_page_young(page);
1177 		ClearPageReferenced(page);
1178 out:
1179 		spin_unlock(ptl);
1180 		return 0;
1181 	}
1182 
1183 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1184 	if (!pte) {
1185 		walk->action = ACTION_AGAIN;
1186 		return 0;
1187 	}
1188 	for (; addr != end; pte++, addr += PAGE_SIZE) {
1189 		ptent = ptep_get(pte);
1190 
1191 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1192 			clear_soft_dirty(vma, addr, pte);
1193 			continue;
1194 		}
1195 
1196 		if (!pte_present(ptent))
1197 			continue;
1198 
1199 		page = vm_normal_page(vma, addr, ptent);
1200 		if (!page)
1201 			continue;
1202 
1203 		/* Clear accessed and referenced bits. */
1204 		ptep_test_and_clear_young(vma, addr, pte);
1205 		test_and_clear_page_young(page);
1206 		ClearPageReferenced(page);
1207 	}
1208 	pte_unmap_unlock(pte - 1, ptl);
1209 	cond_resched();
1210 	return 0;
1211 }
1212 
1213 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1214 				struct mm_walk *walk)
1215 {
1216 	struct clear_refs_private *cp = walk->private;
1217 	struct vm_area_struct *vma = walk->vma;
1218 
1219 	if (vma->vm_flags & VM_PFNMAP)
1220 		return 1;
1221 
1222 	/*
1223 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1224 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1225 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1226 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1227 	 */
1228 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1229 		return 1;
1230 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1231 		return 1;
1232 	return 0;
1233 }
1234 
1235 static const struct mm_walk_ops clear_refs_walk_ops = {
1236 	.pmd_entry		= clear_refs_pte_range,
1237 	.test_walk		= clear_refs_test_walk,
1238 	.walk_lock		= PGWALK_WRLOCK,
1239 };
1240 
1241 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1242 				size_t count, loff_t *ppos)
1243 {
1244 	struct task_struct *task;
1245 	char buffer[PROC_NUMBUF] = {};
1246 	struct mm_struct *mm;
1247 	struct vm_area_struct *vma;
1248 	enum clear_refs_types type;
1249 	int itype;
1250 	int rv;
1251 
1252 	if (count > sizeof(buffer) - 1)
1253 		count = sizeof(buffer) - 1;
1254 	if (copy_from_user(buffer, buf, count))
1255 		return -EFAULT;
1256 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1257 	if (rv < 0)
1258 		return rv;
1259 	type = (enum clear_refs_types)itype;
1260 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1261 		return -EINVAL;
1262 
1263 	task = get_proc_task(file_inode(file));
1264 	if (!task)
1265 		return -ESRCH;
1266 	mm = get_task_mm(task);
1267 	if (mm) {
1268 		VMA_ITERATOR(vmi, mm, 0);
1269 		struct mmu_notifier_range range;
1270 		struct clear_refs_private cp = {
1271 			.type = type,
1272 		};
1273 
1274 		if (mmap_write_lock_killable(mm)) {
1275 			count = -EINTR;
1276 			goto out_mm;
1277 		}
1278 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1279 			/*
1280 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1281 			 * resident set size to this mm's current rss value.
1282 			 */
1283 			reset_mm_hiwater_rss(mm);
1284 			goto out_unlock;
1285 		}
1286 
1287 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1288 			for_each_vma(vmi, vma) {
1289 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1290 					continue;
1291 				vm_flags_clear(vma, VM_SOFTDIRTY);
1292 				vma_set_page_prot(vma);
1293 			}
1294 
1295 			inc_tlb_flush_pending(mm);
1296 			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1297 						0, mm, 0, -1UL);
1298 			mmu_notifier_invalidate_range_start(&range);
1299 		}
1300 		walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
1301 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1302 			mmu_notifier_invalidate_range_end(&range);
1303 			flush_tlb_mm(mm);
1304 			dec_tlb_flush_pending(mm);
1305 		}
1306 out_unlock:
1307 		mmap_write_unlock(mm);
1308 out_mm:
1309 		mmput(mm);
1310 	}
1311 	put_task_struct(task);
1312 
1313 	return count;
1314 }
1315 
1316 const struct file_operations proc_clear_refs_operations = {
1317 	.write		= clear_refs_write,
1318 	.llseek		= noop_llseek,
1319 };
1320 
1321 typedef struct {
1322 	u64 pme;
1323 } pagemap_entry_t;
1324 
1325 struct pagemapread {
1326 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1327 	pagemap_entry_t *buffer;
1328 	bool show_pfn;
1329 };
1330 
1331 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1332 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1333 
1334 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1335 #define PM_PFRAME_BITS		55
1336 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1337 #define PM_SOFT_DIRTY		BIT_ULL(55)
1338 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1339 #define PM_UFFD_WP		BIT_ULL(57)
1340 #define PM_FILE			BIT_ULL(61)
1341 #define PM_SWAP			BIT_ULL(62)
1342 #define PM_PRESENT		BIT_ULL(63)
1343 
1344 #define PM_END_OF_BUFFER    1
1345 
1346 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1347 {
1348 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1349 }
1350 
1351 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1352 			  struct pagemapread *pm)
1353 {
1354 	pm->buffer[pm->pos++] = *pme;
1355 	if (pm->pos >= pm->len)
1356 		return PM_END_OF_BUFFER;
1357 	return 0;
1358 }
1359 
1360 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1361 			    __always_unused int depth, struct mm_walk *walk)
1362 {
1363 	struct pagemapread *pm = walk->private;
1364 	unsigned long addr = start;
1365 	int err = 0;
1366 
1367 	while (addr < end) {
1368 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1369 		pagemap_entry_t pme = make_pme(0, 0);
1370 		/* End of address space hole, which we mark as non-present. */
1371 		unsigned long hole_end;
1372 
1373 		if (vma)
1374 			hole_end = min(end, vma->vm_start);
1375 		else
1376 			hole_end = end;
1377 
1378 		for (; addr < hole_end; addr += PAGE_SIZE) {
1379 			err = add_to_pagemap(addr, &pme, pm);
1380 			if (err)
1381 				goto out;
1382 		}
1383 
1384 		if (!vma)
1385 			break;
1386 
1387 		/* Addresses in the VMA. */
1388 		if (vma->vm_flags & VM_SOFTDIRTY)
1389 			pme = make_pme(0, PM_SOFT_DIRTY);
1390 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1391 			err = add_to_pagemap(addr, &pme, pm);
1392 			if (err)
1393 				goto out;
1394 		}
1395 	}
1396 out:
1397 	return err;
1398 }
1399 
1400 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1401 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1402 {
1403 	u64 frame = 0, flags = 0;
1404 	struct page *page = NULL;
1405 	bool migration = false;
1406 
1407 	if (pte_present(pte)) {
1408 		if (pm->show_pfn)
1409 			frame = pte_pfn(pte);
1410 		flags |= PM_PRESENT;
1411 		page = vm_normal_page(vma, addr, pte);
1412 		if (pte_soft_dirty(pte))
1413 			flags |= PM_SOFT_DIRTY;
1414 		if (pte_uffd_wp(pte))
1415 			flags |= PM_UFFD_WP;
1416 	} else if (is_swap_pte(pte)) {
1417 		swp_entry_t entry;
1418 		if (pte_swp_soft_dirty(pte))
1419 			flags |= PM_SOFT_DIRTY;
1420 		if (pte_swp_uffd_wp(pte))
1421 			flags |= PM_UFFD_WP;
1422 		entry = pte_to_swp_entry(pte);
1423 		if (pm->show_pfn) {
1424 			pgoff_t offset;
1425 			/*
1426 			 * For PFN swap offsets, keeping the offset field
1427 			 * to be PFN only to be compatible with old smaps.
1428 			 */
1429 			if (is_pfn_swap_entry(entry))
1430 				offset = swp_offset_pfn(entry);
1431 			else
1432 				offset = swp_offset(entry);
1433 			frame = swp_type(entry) |
1434 			    (offset << MAX_SWAPFILES_SHIFT);
1435 		}
1436 		flags |= PM_SWAP;
1437 		migration = is_migration_entry(entry);
1438 		if (is_pfn_swap_entry(entry))
1439 			page = pfn_swap_entry_to_page(entry);
1440 		if (pte_marker_entry_uffd_wp(entry))
1441 			flags |= PM_UFFD_WP;
1442 	}
1443 
1444 	if (page && !PageAnon(page))
1445 		flags |= PM_FILE;
1446 	if (page && !migration && page_mapcount(page) == 1)
1447 		flags |= PM_MMAP_EXCLUSIVE;
1448 	if (vma->vm_flags & VM_SOFTDIRTY)
1449 		flags |= PM_SOFT_DIRTY;
1450 
1451 	return make_pme(frame, flags);
1452 }
1453 
1454 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1455 			     struct mm_walk *walk)
1456 {
1457 	struct vm_area_struct *vma = walk->vma;
1458 	struct pagemapread *pm = walk->private;
1459 	spinlock_t *ptl;
1460 	pte_t *pte, *orig_pte;
1461 	int err = 0;
1462 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1463 	bool migration = false;
1464 
1465 	ptl = pmd_trans_huge_lock(pmdp, vma);
1466 	if (ptl) {
1467 		u64 flags = 0, frame = 0;
1468 		pmd_t pmd = *pmdp;
1469 		struct page *page = NULL;
1470 
1471 		if (vma->vm_flags & VM_SOFTDIRTY)
1472 			flags |= PM_SOFT_DIRTY;
1473 
1474 		if (pmd_present(pmd)) {
1475 			page = pmd_page(pmd);
1476 
1477 			flags |= PM_PRESENT;
1478 			if (pmd_soft_dirty(pmd))
1479 				flags |= PM_SOFT_DIRTY;
1480 			if (pmd_uffd_wp(pmd))
1481 				flags |= PM_UFFD_WP;
1482 			if (pm->show_pfn)
1483 				frame = pmd_pfn(pmd) +
1484 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1485 		}
1486 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1487 		else if (is_swap_pmd(pmd)) {
1488 			swp_entry_t entry = pmd_to_swp_entry(pmd);
1489 			unsigned long offset;
1490 
1491 			if (pm->show_pfn) {
1492 				if (is_pfn_swap_entry(entry))
1493 					offset = swp_offset_pfn(entry);
1494 				else
1495 					offset = swp_offset(entry);
1496 				offset = offset +
1497 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1498 				frame = swp_type(entry) |
1499 					(offset << MAX_SWAPFILES_SHIFT);
1500 			}
1501 			flags |= PM_SWAP;
1502 			if (pmd_swp_soft_dirty(pmd))
1503 				flags |= PM_SOFT_DIRTY;
1504 			if (pmd_swp_uffd_wp(pmd))
1505 				flags |= PM_UFFD_WP;
1506 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1507 			migration = is_migration_entry(entry);
1508 			page = pfn_swap_entry_to_page(entry);
1509 		}
1510 #endif
1511 
1512 		if (page && !migration && page_mapcount(page) == 1)
1513 			flags |= PM_MMAP_EXCLUSIVE;
1514 
1515 		for (; addr != end; addr += PAGE_SIZE) {
1516 			pagemap_entry_t pme = make_pme(frame, flags);
1517 
1518 			err = add_to_pagemap(addr, &pme, pm);
1519 			if (err)
1520 				break;
1521 			if (pm->show_pfn) {
1522 				if (flags & PM_PRESENT)
1523 					frame++;
1524 				else if (flags & PM_SWAP)
1525 					frame += (1 << MAX_SWAPFILES_SHIFT);
1526 			}
1527 		}
1528 		spin_unlock(ptl);
1529 		return err;
1530 	}
1531 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1532 
1533 	/*
1534 	 * We can assume that @vma always points to a valid one and @end never
1535 	 * goes beyond vma->vm_end.
1536 	 */
1537 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1538 	if (!pte) {
1539 		walk->action = ACTION_AGAIN;
1540 		return err;
1541 	}
1542 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1543 		pagemap_entry_t pme;
1544 
1545 		pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
1546 		err = add_to_pagemap(addr, &pme, pm);
1547 		if (err)
1548 			break;
1549 	}
1550 	pte_unmap_unlock(orig_pte, ptl);
1551 
1552 	cond_resched();
1553 
1554 	return err;
1555 }
1556 
1557 #ifdef CONFIG_HUGETLB_PAGE
1558 /* This function walks within one hugetlb entry in the single call */
1559 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1560 				 unsigned long addr, unsigned long end,
1561 				 struct mm_walk *walk)
1562 {
1563 	struct pagemapread *pm = walk->private;
1564 	struct vm_area_struct *vma = walk->vma;
1565 	u64 flags = 0, frame = 0;
1566 	int err = 0;
1567 	pte_t pte;
1568 
1569 	if (vma->vm_flags & VM_SOFTDIRTY)
1570 		flags |= PM_SOFT_DIRTY;
1571 
1572 	pte = huge_ptep_get(ptep);
1573 	if (pte_present(pte)) {
1574 		struct page *page = pte_page(pte);
1575 
1576 		if (!PageAnon(page))
1577 			flags |= PM_FILE;
1578 
1579 		if (page_mapcount(page) == 1)
1580 			flags |= PM_MMAP_EXCLUSIVE;
1581 
1582 		if (huge_pte_uffd_wp(pte))
1583 			flags |= PM_UFFD_WP;
1584 
1585 		flags |= PM_PRESENT;
1586 		if (pm->show_pfn)
1587 			frame = pte_pfn(pte) +
1588 				((addr & ~hmask) >> PAGE_SHIFT);
1589 	} else if (pte_swp_uffd_wp_any(pte)) {
1590 		flags |= PM_UFFD_WP;
1591 	}
1592 
1593 	for (; addr != end; addr += PAGE_SIZE) {
1594 		pagemap_entry_t pme = make_pme(frame, flags);
1595 
1596 		err = add_to_pagemap(addr, &pme, pm);
1597 		if (err)
1598 			return err;
1599 		if (pm->show_pfn && (flags & PM_PRESENT))
1600 			frame++;
1601 	}
1602 
1603 	cond_resched();
1604 
1605 	return err;
1606 }
1607 #else
1608 #define pagemap_hugetlb_range	NULL
1609 #endif /* HUGETLB_PAGE */
1610 
1611 static const struct mm_walk_ops pagemap_ops = {
1612 	.pmd_entry	= pagemap_pmd_range,
1613 	.pte_hole	= pagemap_pte_hole,
1614 	.hugetlb_entry	= pagemap_hugetlb_range,
1615 	.walk_lock	= PGWALK_RDLOCK,
1616 };
1617 
1618 /*
1619  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1620  *
1621  * For each page in the address space, this file contains one 64-bit entry
1622  * consisting of the following:
1623  *
1624  * Bits 0-54  page frame number (PFN) if present
1625  * Bits 0-4   swap type if swapped
1626  * Bits 5-54  swap offset if swapped
1627  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1628  * Bit  56    page exclusively mapped
1629  * Bit  57    pte is uffd-wp write-protected
1630  * Bits 58-60 zero
1631  * Bit  61    page is file-page or shared-anon
1632  * Bit  62    page swapped
1633  * Bit  63    page present
1634  *
1635  * If the page is not present but in swap, then the PFN contains an
1636  * encoding of the swap file number and the page's offset into the
1637  * swap. Unmapped pages return a null PFN. This allows determining
1638  * precisely which pages are mapped (or in swap) and comparing mapped
1639  * pages between processes.
1640  *
1641  * Efficient users of this interface will use /proc/pid/maps to
1642  * determine which areas of memory are actually mapped and llseek to
1643  * skip over unmapped regions.
1644  */
1645 static ssize_t pagemap_read(struct file *file, char __user *buf,
1646 			    size_t count, loff_t *ppos)
1647 {
1648 	struct mm_struct *mm = file->private_data;
1649 	struct pagemapread pm;
1650 	unsigned long src;
1651 	unsigned long svpfn;
1652 	unsigned long start_vaddr;
1653 	unsigned long end_vaddr;
1654 	int ret = 0, copied = 0;
1655 
1656 	if (!mm || !mmget_not_zero(mm))
1657 		goto out;
1658 
1659 	ret = -EINVAL;
1660 	/* file position must be aligned */
1661 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1662 		goto out_mm;
1663 
1664 	ret = 0;
1665 	if (!count)
1666 		goto out_mm;
1667 
1668 	/* do not disclose physical addresses: attack vector */
1669 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1670 
1671 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1672 	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1673 	ret = -ENOMEM;
1674 	if (!pm.buffer)
1675 		goto out_mm;
1676 
1677 	src = *ppos;
1678 	svpfn = src / PM_ENTRY_BYTES;
1679 	end_vaddr = mm->task_size;
1680 
1681 	/* watch out for wraparound */
1682 	start_vaddr = end_vaddr;
1683 	if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
1684 		unsigned long end;
1685 
1686 		ret = mmap_read_lock_killable(mm);
1687 		if (ret)
1688 			goto out_free;
1689 		start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1690 		mmap_read_unlock(mm);
1691 
1692 		end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1693 		if (end >= start_vaddr && end < mm->task_size)
1694 			end_vaddr = end;
1695 	}
1696 
1697 	/* Ensure the address is inside the task */
1698 	if (start_vaddr > mm->task_size)
1699 		start_vaddr = end_vaddr;
1700 
1701 	ret = 0;
1702 	while (count && (start_vaddr < end_vaddr)) {
1703 		int len;
1704 		unsigned long end;
1705 
1706 		pm.pos = 0;
1707 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1708 		/* overflow ? */
1709 		if (end < start_vaddr || end > end_vaddr)
1710 			end = end_vaddr;
1711 		ret = mmap_read_lock_killable(mm);
1712 		if (ret)
1713 			goto out_free;
1714 		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1715 		mmap_read_unlock(mm);
1716 		start_vaddr = end;
1717 
1718 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1719 		if (copy_to_user(buf, pm.buffer, len)) {
1720 			ret = -EFAULT;
1721 			goto out_free;
1722 		}
1723 		copied += len;
1724 		buf += len;
1725 		count -= len;
1726 	}
1727 	*ppos += copied;
1728 	if (!ret || ret == PM_END_OF_BUFFER)
1729 		ret = copied;
1730 
1731 out_free:
1732 	kfree(pm.buffer);
1733 out_mm:
1734 	mmput(mm);
1735 out:
1736 	return ret;
1737 }
1738 
1739 static int pagemap_open(struct inode *inode, struct file *file)
1740 {
1741 	struct mm_struct *mm;
1742 
1743 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1744 	if (IS_ERR(mm))
1745 		return PTR_ERR(mm);
1746 	file->private_data = mm;
1747 	return 0;
1748 }
1749 
1750 static int pagemap_release(struct inode *inode, struct file *file)
1751 {
1752 	struct mm_struct *mm = file->private_data;
1753 
1754 	if (mm)
1755 		mmdrop(mm);
1756 	return 0;
1757 }
1758 
1759 const struct file_operations proc_pagemap_operations = {
1760 	.llseek		= mem_lseek, /* borrow this */
1761 	.read		= pagemap_read,
1762 	.open		= pagemap_open,
1763 	.release	= pagemap_release,
1764 };
1765 #endif /* CONFIG_PROC_PAGE_MONITOR */
1766 
1767 #ifdef CONFIG_NUMA
1768 
1769 struct numa_maps {
1770 	unsigned long pages;
1771 	unsigned long anon;
1772 	unsigned long active;
1773 	unsigned long writeback;
1774 	unsigned long mapcount_max;
1775 	unsigned long dirty;
1776 	unsigned long swapcache;
1777 	unsigned long node[MAX_NUMNODES];
1778 };
1779 
1780 struct numa_maps_private {
1781 	struct proc_maps_private proc_maps;
1782 	struct numa_maps md;
1783 };
1784 
1785 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1786 			unsigned long nr_pages)
1787 {
1788 	int count = page_mapcount(page);
1789 
1790 	md->pages += nr_pages;
1791 	if (pte_dirty || PageDirty(page))
1792 		md->dirty += nr_pages;
1793 
1794 	if (PageSwapCache(page))
1795 		md->swapcache += nr_pages;
1796 
1797 	if (PageActive(page) || PageUnevictable(page))
1798 		md->active += nr_pages;
1799 
1800 	if (PageWriteback(page))
1801 		md->writeback += nr_pages;
1802 
1803 	if (PageAnon(page))
1804 		md->anon += nr_pages;
1805 
1806 	if (count > md->mapcount_max)
1807 		md->mapcount_max = count;
1808 
1809 	md->node[page_to_nid(page)] += nr_pages;
1810 }
1811 
1812 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1813 		unsigned long addr)
1814 {
1815 	struct page *page;
1816 	int nid;
1817 
1818 	if (!pte_present(pte))
1819 		return NULL;
1820 
1821 	page = vm_normal_page(vma, addr, pte);
1822 	if (!page || is_zone_device_page(page))
1823 		return NULL;
1824 
1825 	if (PageReserved(page))
1826 		return NULL;
1827 
1828 	nid = page_to_nid(page);
1829 	if (!node_isset(nid, node_states[N_MEMORY]))
1830 		return NULL;
1831 
1832 	return page;
1833 }
1834 
1835 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1836 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1837 					      struct vm_area_struct *vma,
1838 					      unsigned long addr)
1839 {
1840 	struct page *page;
1841 	int nid;
1842 
1843 	if (!pmd_present(pmd))
1844 		return NULL;
1845 
1846 	page = vm_normal_page_pmd(vma, addr, pmd);
1847 	if (!page)
1848 		return NULL;
1849 
1850 	if (PageReserved(page))
1851 		return NULL;
1852 
1853 	nid = page_to_nid(page);
1854 	if (!node_isset(nid, node_states[N_MEMORY]))
1855 		return NULL;
1856 
1857 	return page;
1858 }
1859 #endif
1860 
1861 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1862 		unsigned long end, struct mm_walk *walk)
1863 {
1864 	struct numa_maps *md = walk->private;
1865 	struct vm_area_struct *vma = walk->vma;
1866 	spinlock_t *ptl;
1867 	pte_t *orig_pte;
1868 	pte_t *pte;
1869 
1870 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1871 	ptl = pmd_trans_huge_lock(pmd, vma);
1872 	if (ptl) {
1873 		struct page *page;
1874 
1875 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1876 		if (page)
1877 			gather_stats(page, md, pmd_dirty(*pmd),
1878 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1879 		spin_unlock(ptl);
1880 		return 0;
1881 	}
1882 #endif
1883 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1884 	if (!pte) {
1885 		walk->action = ACTION_AGAIN;
1886 		return 0;
1887 	}
1888 	do {
1889 		pte_t ptent = ptep_get(pte);
1890 		struct page *page = can_gather_numa_stats(ptent, vma, addr);
1891 		if (!page)
1892 			continue;
1893 		gather_stats(page, md, pte_dirty(ptent), 1);
1894 
1895 	} while (pte++, addr += PAGE_SIZE, addr != end);
1896 	pte_unmap_unlock(orig_pte, ptl);
1897 	cond_resched();
1898 	return 0;
1899 }
1900 #ifdef CONFIG_HUGETLB_PAGE
1901 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1902 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1903 {
1904 	pte_t huge_pte = huge_ptep_get(pte);
1905 	struct numa_maps *md;
1906 	struct page *page;
1907 
1908 	if (!pte_present(huge_pte))
1909 		return 0;
1910 
1911 	page = pte_page(huge_pte);
1912 
1913 	md = walk->private;
1914 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1915 	return 0;
1916 }
1917 
1918 #else
1919 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1920 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1921 {
1922 	return 0;
1923 }
1924 #endif
1925 
1926 static const struct mm_walk_ops show_numa_ops = {
1927 	.hugetlb_entry = gather_hugetlb_stats,
1928 	.pmd_entry = gather_pte_stats,
1929 	.walk_lock = PGWALK_RDLOCK,
1930 };
1931 
1932 /*
1933  * Display pages allocated per node and memory policy via /proc.
1934  */
1935 static int show_numa_map(struct seq_file *m, void *v)
1936 {
1937 	struct numa_maps_private *numa_priv = m->private;
1938 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1939 	struct vm_area_struct *vma = v;
1940 	struct numa_maps *md = &numa_priv->md;
1941 	struct file *file = vma->vm_file;
1942 	struct mm_struct *mm = vma->vm_mm;
1943 	struct mempolicy *pol;
1944 	char buffer[64];
1945 	int nid;
1946 
1947 	if (!mm)
1948 		return 0;
1949 
1950 	/* Ensure we start with an empty set of numa_maps statistics. */
1951 	memset(md, 0, sizeof(*md));
1952 
1953 	pol = __get_vma_policy(vma, vma->vm_start);
1954 	if (pol) {
1955 		mpol_to_str(buffer, sizeof(buffer), pol);
1956 		mpol_cond_put(pol);
1957 	} else {
1958 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1959 	}
1960 
1961 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1962 
1963 	if (file) {
1964 		seq_puts(m, " file=");
1965 		seq_file_path(m, file, "\n\t= ");
1966 	} else if (vma_is_initial_heap(vma)) {
1967 		seq_puts(m, " heap");
1968 	} else if (vma_is_initial_stack(vma)) {
1969 		seq_puts(m, " stack");
1970 	}
1971 
1972 	if (is_vm_hugetlb_page(vma))
1973 		seq_puts(m, " huge");
1974 
1975 	/* mmap_lock is held by m_start */
1976 	walk_page_vma(vma, &show_numa_ops, md);
1977 
1978 	if (!md->pages)
1979 		goto out;
1980 
1981 	if (md->anon)
1982 		seq_printf(m, " anon=%lu", md->anon);
1983 
1984 	if (md->dirty)
1985 		seq_printf(m, " dirty=%lu", md->dirty);
1986 
1987 	if (md->pages != md->anon && md->pages != md->dirty)
1988 		seq_printf(m, " mapped=%lu", md->pages);
1989 
1990 	if (md->mapcount_max > 1)
1991 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1992 
1993 	if (md->swapcache)
1994 		seq_printf(m, " swapcache=%lu", md->swapcache);
1995 
1996 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1997 		seq_printf(m, " active=%lu", md->active);
1998 
1999 	if (md->writeback)
2000 		seq_printf(m, " writeback=%lu", md->writeback);
2001 
2002 	for_each_node_state(nid, N_MEMORY)
2003 		if (md->node[nid])
2004 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
2005 
2006 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
2007 out:
2008 	seq_putc(m, '\n');
2009 	return 0;
2010 }
2011 
2012 static const struct seq_operations proc_pid_numa_maps_op = {
2013 	.start  = m_start,
2014 	.next   = m_next,
2015 	.stop   = m_stop,
2016 	.show   = show_numa_map,
2017 };
2018 
2019 static int pid_numa_maps_open(struct inode *inode, struct file *file)
2020 {
2021 	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2022 				sizeof(struct numa_maps_private));
2023 }
2024 
2025 const struct file_operations proc_pid_numa_maps_operations = {
2026 	.open		= pid_numa_maps_open,
2027 	.read		= seq_read,
2028 	.llseek		= seq_lseek,
2029 	.release	= proc_map_release,
2030 };
2031 
2032 #endif /* CONFIG_NUMA */
2033