xref: /linux/fs/proc/task_mmu.c (revision f9bff0e31881d03badf191d3b0005839391f5f2b)
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/seq_file.h>
8 #include <linux/highmem.h>
9 #include <linux/ptrace.h>
10 #include <linux/slab.h>
11 #include <linux/pagemap.h>
12 #include <linux/mempolicy.h>
13 #include <linux/rmap.h>
14 #include <linux/swap.h>
15 #include <linux/sched/mm.h>
16 #include <linux/swapops.h>
17 #include <linux/mmu_notifier.h>
18 #include <linux/page_idle.h>
19 #include <linux/shmem_fs.h>
20 #include <linux/uaccess.h>
21 #include <linux/pkeys.h>
22 
23 #include <asm/elf.h>
24 #include <asm/tlb.h>
25 #include <asm/tlbflush.h>
26 #include "internal.h"
27 
28 #define SEQ_PUT_DEC(str, val) \
29 		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
30 void task_mem(struct seq_file *m, struct mm_struct *mm)
31 {
32 	unsigned long text, lib, swap, anon, file, shmem;
33 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
34 
35 	anon = get_mm_counter(mm, MM_ANONPAGES);
36 	file = get_mm_counter(mm, MM_FILEPAGES);
37 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
38 
39 	/*
40 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
41 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
42 	 * collector of these hiwater stats must therefore get total_vm
43 	 * and rss too, which will usually be the higher.  Barriers? not
44 	 * worth the effort, such snapshots can always be inconsistent.
45 	 */
46 	hiwater_vm = total_vm = mm->total_vm;
47 	if (hiwater_vm < mm->hiwater_vm)
48 		hiwater_vm = mm->hiwater_vm;
49 	hiwater_rss = total_rss = anon + file + shmem;
50 	if (hiwater_rss < mm->hiwater_rss)
51 		hiwater_rss = mm->hiwater_rss;
52 
53 	/* split executable areas between text and lib */
54 	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
55 	text = min(text, mm->exec_vm << PAGE_SHIFT);
56 	lib = (mm->exec_vm << PAGE_SHIFT) - text;
57 
58 	swap = get_mm_counter(mm, MM_SWAPENTS);
59 	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
60 	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
61 	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
62 	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
63 	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
64 	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
65 	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
66 	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
67 	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
68 	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
69 	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
70 	seq_put_decimal_ull_width(m,
71 		    " kB\nVmExe:\t", text >> 10, 8);
72 	seq_put_decimal_ull_width(m,
73 		    " kB\nVmLib:\t", lib >> 10, 8);
74 	seq_put_decimal_ull_width(m,
75 		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
76 	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
77 	seq_puts(m, " kB\n");
78 	hugetlb_report_usage(m, mm);
79 }
80 #undef SEQ_PUT_DEC
81 
82 unsigned long task_vsize(struct mm_struct *mm)
83 {
84 	return PAGE_SIZE * mm->total_vm;
85 }
86 
87 unsigned long task_statm(struct mm_struct *mm,
88 			 unsigned long *shared, unsigned long *text,
89 			 unsigned long *data, unsigned long *resident)
90 {
91 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
92 			get_mm_counter(mm, MM_SHMEMPAGES);
93 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
94 								>> PAGE_SHIFT;
95 	*data = mm->data_vm + mm->stack_vm;
96 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
97 	return mm->total_vm;
98 }
99 
100 #ifdef CONFIG_NUMA
101 /*
102  * Save get_task_policy() for show_numa_map().
103  */
104 static void hold_task_mempolicy(struct proc_maps_private *priv)
105 {
106 	struct task_struct *task = priv->task;
107 
108 	task_lock(task);
109 	priv->task_mempolicy = get_task_policy(task);
110 	mpol_get(priv->task_mempolicy);
111 	task_unlock(task);
112 }
113 static void release_task_mempolicy(struct proc_maps_private *priv)
114 {
115 	mpol_put(priv->task_mempolicy);
116 }
117 #else
118 static void hold_task_mempolicy(struct proc_maps_private *priv)
119 {
120 }
121 static void release_task_mempolicy(struct proc_maps_private *priv)
122 {
123 }
124 #endif
125 
126 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
127 						loff_t *ppos)
128 {
129 	struct vm_area_struct *vma = vma_next(&priv->iter);
130 
131 	if (vma) {
132 		*ppos = vma->vm_start;
133 	} else {
134 		*ppos = -2UL;
135 		vma = get_gate_vma(priv->mm);
136 	}
137 
138 	return vma;
139 }
140 
141 static void *m_start(struct seq_file *m, loff_t *ppos)
142 {
143 	struct proc_maps_private *priv = m->private;
144 	unsigned long last_addr = *ppos;
145 	struct mm_struct *mm;
146 
147 	/* See m_next(). Zero at the start or after lseek. */
148 	if (last_addr == -1UL)
149 		return NULL;
150 
151 	priv->task = get_proc_task(priv->inode);
152 	if (!priv->task)
153 		return ERR_PTR(-ESRCH);
154 
155 	mm = priv->mm;
156 	if (!mm || !mmget_not_zero(mm)) {
157 		put_task_struct(priv->task);
158 		priv->task = NULL;
159 		return NULL;
160 	}
161 
162 	if (mmap_read_lock_killable(mm)) {
163 		mmput(mm);
164 		put_task_struct(priv->task);
165 		priv->task = NULL;
166 		return ERR_PTR(-EINTR);
167 	}
168 
169 	vma_iter_init(&priv->iter, mm, last_addr);
170 	hold_task_mempolicy(priv);
171 	if (last_addr == -2UL)
172 		return get_gate_vma(mm);
173 
174 	return proc_get_vma(priv, ppos);
175 }
176 
177 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
178 {
179 	if (*ppos == -2UL) {
180 		*ppos = -1UL;
181 		return NULL;
182 	}
183 	return proc_get_vma(m->private, ppos);
184 }
185 
186 static void m_stop(struct seq_file *m, void *v)
187 {
188 	struct proc_maps_private *priv = m->private;
189 	struct mm_struct *mm = priv->mm;
190 
191 	if (!priv->task)
192 		return;
193 
194 	release_task_mempolicy(priv);
195 	mmap_read_unlock(mm);
196 	mmput(mm);
197 	put_task_struct(priv->task);
198 	priv->task = NULL;
199 }
200 
201 static int proc_maps_open(struct inode *inode, struct file *file,
202 			const struct seq_operations *ops, int psize)
203 {
204 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
205 
206 	if (!priv)
207 		return -ENOMEM;
208 
209 	priv->inode = inode;
210 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
211 	if (IS_ERR(priv->mm)) {
212 		int err = PTR_ERR(priv->mm);
213 
214 		seq_release_private(inode, file);
215 		return err;
216 	}
217 
218 	return 0;
219 }
220 
221 static int proc_map_release(struct inode *inode, struct file *file)
222 {
223 	struct seq_file *seq = file->private_data;
224 	struct proc_maps_private *priv = seq->private;
225 
226 	if (priv->mm)
227 		mmdrop(priv->mm);
228 
229 	return seq_release_private(inode, file);
230 }
231 
232 static int do_maps_open(struct inode *inode, struct file *file,
233 			const struct seq_operations *ops)
234 {
235 	return proc_maps_open(inode, file, ops,
236 				sizeof(struct proc_maps_private));
237 }
238 
239 static void show_vma_header_prefix(struct seq_file *m,
240 				   unsigned long start, unsigned long end,
241 				   vm_flags_t flags, unsigned long long pgoff,
242 				   dev_t dev, unsigned long ino)
243 {
244 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
245 	seq_put_hex_ll(m, NULL, start, 8);
246 	seq_put_hex_ll(m, "-", end, 8);
247 	seq_putc(m, ' ');
248 	seq_putc(m, flags & VM_READ ? 'r' : '-');
249 	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
250 	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
251 	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
252 	seq_put_hex_ll(m, " ", pgoff, 8);
253 	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
254 	seq_put_hex_ll(m, ":", MINOR(dev), 2);
255 	seq_put_decimal_ull(m, " ", ino);
256 	seq_putc(m, ' ');
257 }
258 
259 static void
260 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
261 {
262 	struct anon_vma_name *anon_name = NULL;
263 	struct mm_struct *mm = vma->vm_mm;
264 	struct file *file = vma->vm_file;
265 	vm_flags_t flags = vma->vm_flags;
266 	unsigned long ino = 0;
267 	unsigned long long pgoff = 0;
268 	unsigned long start, end;
269 	dev_t dev = 0;
270 	const char *name = NULL;
271 
272 	if (file) {
273 		struct inode *inode = file_inode(vma->vm_file);
274 		dev = inode->i_sb->s_dev;
275 		ino = inode->i_ino;
276 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
277 	}
278 
279 	start = vma->vm_start;
280 	end = vma->vm_end;
281 	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
282 	if (mm)
283 		anon_name = anon_vma_name(vma);
284 
285 	/*
286 	 * Print the dentry name for named mappings, and a
287 	 * special [heap] marker for the heap:
288 	 */
289 	if (file) {
290 		seq_pad(m, ' ');
291 		/*
292 		 * If user named this anon shared memory via
293 		 * prctl(PR_SET_VMA ..., use the provided name.
294 		 */
295 		if (anon_name)
296 			seq_printf(m, "[anon_shmem:%s]", anon_name->name);
297 		else
298 			seq_file_path(m, file, "\n");
299 		goto done;
300 	}
301 
302 	if (vma->vm_ops && vma->vm_ops->name) {
303 		name = vma->vm_ops->name(vma);
304 		if (name)
305 			goto done;
306 	}
307 
308 	name = arch_vma_name(vma);
309 	if (!name) {
310 		if (!mm) {
311 			name = "[vdso]";
312 			goto done;
313 		}
314 
315 		if (vma_is_initial_heap(vma)) {
316 			name = "[heap]";
317 			goto done;
318 		}
319 
320 		if (vma_is_initial_stack(vma)) {
321 			name = "[stack]";
322 			goto done;
323 		}
324 
325 		if (anon_name) {
326 			seq_pad(m, ' ');
327 			seq_printf(m, "[anon:%s]", anon_name->name);
328 		}
329 	}
330 
331 done:
332 	if (name) {
333 		seq_pad(m, ' ');
334 		seq_puts(m, name);
335 	}
336 	seq_putc(m, '\n');
337 }
338 
339 static int show_map(struct seq_file *m, void *v)
340 {
341 	show_map_vma(m, v);
342 	return 0;
343 }
344 
345 static const struct seq_operations proc_pid_maps_op = {
346 	.start	= m_start,
347 	.next	= m_next,
348 	.stop	= m_stop,
349 	.show	= show_map
350 };
351 
352 static int pid_maps_open(struct inode *inode, struct file *file)
353 {
354 	return do_maps_open(inode, file, &proc_pid_maps_op);
355 }
356 
357 const struct file_operations proc_pid_maps_operations = {
358 	.open		= pid_maps_open,
359 	.read		= seq_read,
360 	.llseek		= seq_lseek,
361 	.release	= proc_map_release,
362 };
363 
364 /*
365  * Proportional Set Size(PSS): my share of RSS.
366  *
367  * PSS of a process is the count of pages it has in memory, where each
368  * page is divided by the number of processes sharing it.  So if a
369  * process has 1000 pages all to itself, and 1000 shared with one other
370  * process, its PSS will be 1500.
371  *
372  * To keep (accumulated) division errors low, we adopt a 64bit
373  * fixed-point pss counter to minimize division errors. So (pss >>
374  * PSS_SHIFT) would be the real byte count.
375  *
376  * A shift of 12 before division means (assuming 4K page size):
377  * 	- 1M 3-user-pages add up to 8KB errors;
378  * 	- supports mapcount up to 2^24, or 16M;
379  * 	- supports PSS up to 2^52 bytes, or 4PB.
380  */
381 #define PSS_SHIFT 12
382 
383 #ifdef CONFIG_PROC_PAGE_MONITOR
384 struct mem_size_stats {
385 	unsigned long resident;
386 	unsigned long shared_clean;
387 	unsigned long shared_dirty;
388 	unsigned long private_clean;
389 	unsigned long private_dirty;
390 	unsigned long referenced;
391 	unsigned long anonymous;
392 	unsigned long lazyfree;
393 	unsigned long anonymous_thp;
394 	unsigned long shmem_thp;
395 	unsigned long file_thp;
396 	unsigned long swap;
397 	unsigned long shared_hugetlb;
398 	unsigned long private_hugetlb;
399 	u64 pss;
400 	u64 pss_anon;
401 	u64 pss_file;
402 	u64 pss_shmem;
403 	u64 pss_dirty;
404 	u64 pss_locked;
405 	u64 swap_pss;
406 };
407 
408 static void smaps_page_accumulate(struct mem_size_stats *mss,
409 		struct page *page, unsigned long size, unsigned long pss,
410 		bool dirty, bool locked, bool private)
411 {
412 	mss->pss += pss;
413 
414 	if (PageAnon(page))
415 		mss->pss_anon += pss;
416 	else if (PageSwapBacked(page))
417 		mss->pss_shmem += pss;
418 	else
419 		mss->pss_file += pss;
420 
421 	if (locked)
422 		mss->pss_locked += pss;
423 
424 	if (dirty || PageDirty(page)) {
425 		mss->pss_dirty += pss;
426 		if (private)
427 			mss->private_dirty += size;
428 		else
429 			mss->shared_dirty += size;
430 	} else {
431 		if (private)
432 			mss->private_clean += size;
433 		else
434 			mss->shared_clean += size;
435 	}
436 }
437 
438 static void smaps_account(struct mem_size_stats *mss, struct page *page,
439 		bool compound, bool young, bool dirty, bool locked,
440 		bool migration)
441 {
442 	int i, nr = compound ? compound_nr(page) : 1;
443 	unsigned long size = nr * PAGE_SIZE;
444 
445 	/*
446 	 * First accumulate quantities that depend only on |size| and the type
447 	 * of the compound page.
448 	 */
449 	if (PageAnon(page)) {
450 		mss->anonymous += size;
451 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
452 			mss->lazyfree += size;
453 	}
454 
455 	mss->resident += size;
456 	/* Accumulate the size in pages that have been accessed. */
457 	if (young || page_is_young(page) || PageReferenced(page))
458 		mss->referenced += size;
459 
460 	/*
461 	 * Then accumulate quantities that may depend on sharing, or that may
462 	 * differ page-by-page.
463 	 *
464 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
465 	 * If any subpage of the compound page mapped with PTE it would elevate
466 	 * page_count().
467 	 *
468 	 * The page_mapcount() is called to get a snapshot of the mapcount.
469 	 * Without holding the page lock this snapshot can be slightly wrong as
470 	 * we cannot always read the mapcount atomically.  It is not safe to
471 	 * call page_mapcount() even with PTL held if the page is not mapped,
472 	 * especially for migration entries.  Treat regular migration entries
473 	 * as mapcount == 1.
474 	 */
475 	if ((page_count(page) == 1) || migration) {
476 		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
477 			locked, true);
478 		return;
479 	}
480 	for (i = 0; i < nr; i++, page++) {
481 		int mapcount = page_mapcount(page);
482 		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
483 		if (mapcount >= 2)
484 			pss /= mapcount;
485 		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
486 				      mapcount < 2);
487 	}
488 }
489 
490 #ifdef CONFIG_SHMEM
491 static int smaps_pte_hole(unsigned long addr, unsigned long end,
492 			  __always_unused int depth, struct mm_walk *walk)
493 {
494 	struct mem_size_stats *mss = walk->private;
495 	struct vm_area_struct *vma = walk->vma;
496 
497 	mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
498 					      linear_page_index(vma, addr),
499 					      linear_page_index(vma, end));
500 
501 	return 0;
502 }
503 #else
504 #define smaps_pte_hole		NULL
505 #endif /* CONFIG_SHMEM */
506 
507 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
508 {
509 #ifdef CONFIG_SHMEM
510 	if (walk->ops->pte_hole) {
511 		/* depth is not used */
512 		smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
513 	}
514 #endif
515 }
516 
517 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
518 		struct mm_walk *walk)
519 {
520 	struct mem_size_stats *mss = walk->private;
521 	struct vm_area_struct *vma = walk->vma;
522 	bool locked = !!(vma->vm_flags & VM_LOCKED);
523 	struct page *page = NULL;
524 	bool migration = false, young = false, dirty = false;
525 	pte_t ptent = ptep_get(pte);
526 
527 	if (pte_present(ptent)) {
528 		page = vm_normal_page(vma, addr, ptent);
529 		young = pte_young(ptent);
530 		dirty = pte_dirty(ptent);
531 	} else if (is_swap_pte(ptent)) {
532 		swp_entry_t swpent = pte_to_swp_entry(ptent);
533 
534 		if (!non_swap_entry(swpent)) {
535 			int mapcount;
536 
537 			mss->swap += PAGE_SIZE;
538 			mapcount = swp_swapcount(swpent);
539 			if (mapcount >= 2) {
540 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
541 
542 				do_div(pss_delta, mapcount);
543 				mss->swap_pss += pss_delta;
544 			} else {
545 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
546 			}
547 		} else if (is_pfn_swap_entry(swpent)) {
548 			if (is_migration_entry(swpent))
549 				migration = true;
550 			page = pfn_swap_entry_to_page(swpent);
551 		}
552 	} else {
553 		smaps_pte_hole_lookup(addr, walk);
554 		return;
555 	}
556 
557 	if (!page)
558 		return;
559 
560 	smaps_account(mss, page, false, young, dirty, locked, migration);
561 }
562 
563 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
564 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
565 		struct mm_walk *walk)
566 {
567 	struct mem_size_stats *mss = walk->private;
568 	struct vm_area_struct *vma = walk->vma;
569 	bool locked = !!(vma->vm_flags & VM_LOCKED);
570 	struct page *page = NULL;
571 	bool migration = false;
572 
573 	if (pmd_present(*pmd)) {
574 		page = vm_normal_page_pmd(vma, addr, *pmd);
575 	} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
576 		swp_entry_t entry = pmd_to_swp_entry(*pmd);
577 
578 		if (is_migration_entry(entry)) {
579 			migration = true;
580 			page = pfn_swap_entry_to_page(entry);
581 		}
582 	}
583 	if (IS_ERR_OR_NULL(page))
584 		return;
585 	if (PageAnon(page))
586 		mss->anonymous_thp += HPAGE_PMD_SIZE;
587 	else if (PageSwapBacked(page))
588 		mss->shmem_thp += HPAGE_PMD_SIZE;
589 	else if (is_zone_device_page(page))
590 		/* pass */;
591 	else
592 		mss->file_thp += HPAGE_PMD_SIZE;
593 
594 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
595 		      locked, migration);
596 }
597 #else
598 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
599 		struct mm_walk *walk)
600 {
601 }
602 #endif
603 
604 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
605 			   struct mm_walk *walk)
606 {
607 	struct vm_area_struct *vma = walk->vma;
608 	pte_t *pte;
609 	spinlock_t *ptl;
610 
611 	ptl = pmd_trans_huge_lock(pmd, vma);
612 	if (ptl) {
613 		smaps_pmd_entry(pmd, addr, walk);
614 		spin_unlock(ptl);
615 		goto out;
616 	}
617 
618 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
619 	if (!pte) {
620 		walk->action = ACTION_AGAIN;
621 		return 0;
622 	}
623 	for (; addr != end; pte++, addr += PAGE_SIZE)
624 		smaps_pte_entry(pte, addr, walk);
625 	pte_unmap_unlock(pte - 1, ptl);
626 out:
627 	cond_resched();
628 	return 0;
629 }
630 
631 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
632 {
633 	/*
634 	 * Don't forget to update Documentation/ on changes.
635 	 */
636 	static const char mnemonics[BITS_PER_LONG][2] = {
637 		/*
638 		 * In case if we meet a flag we don't know about.
639 		 */
640 		[0 ... (BITS_PER_LONG-1)] = "??",
641 
642 		[ilog2(VM_READ)]	= "rd",
643 		[ilog2(VM_WRITE)]	= "wr",
644 		[ilog2(VM_EXEC)]	= "ex",
645 		[ilog2(VM_SHARED)]	= "sh",
646 		[ilog2(VM_MAYREAD)]	= "mr",
647 		[ilog2(VM_MAYWRITE)]	= "mw",
648 		[ilog2(VM_MAYEXEC)]	= "me",
649 		[ilog2(VM_MAYSHARE)]	= "ms",
650 		[ilog2(VM_GROWSDOWN)]	= "gd",
651 		[ilog2(VM_PFNMAP)]	= "pf",
652 		[ilog2(VM_LOCKED)]	= "lo",
653 		[ilog2(VM_IO)]		= "io",
654 		[ilog2(VM_SEQ_READ)]	= "sr",
655 		[ilog2(VM_RAND_READ)]	= "rr",
656 		[ilog2(VM_DONTCOPY)]	= "dc",
657 		[ilog2(VM_DONTEXPAND)]	= "de",
658 		[ilog2(VM_LOCKONFAULT)]	= "lf",
659 		[ilog2(VM_ACCOUNT)]	= "ac",
660 		[ilog2(VM_NORESERVE)]	= "nr",
661 		[ilog2(VM_HUGETLB)]	= "ht",
662 		[ilog2(VM_SYNC)]	= "sf",
663 		[ilog2(VM_ARCH_1)]	= "ar",
664 		[ilog2(VM_WIPEONFORK)]	= "wf",
665 		[ilog2(VM_DONTDUMP)]	= "dd",
666 #ifdef CONFIG_ARM64_BTI
667 		[ilog2(VM_ARM64_BTI)]	= "bt",
668 #endif
669 #ifdef CONFIG_MEM_SOFT_DIRTY
670 		[ilog2(VM_SOFTDIRTY)]	= "sd",
671 #endif
672 		[ilog2(VM_MIXEDMAP)]	= "mm",
673 		[ilog2(VM_HUGEPAGE)]	= "hg",
674 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
675 		[ilog2(VM_MERGEABLE)]	= "mg",
676 		[ilog2(VM_UFFD_MISSING)]= "um",
677 		[ilog2(VM_UFFD_WP)]	= "uw",
678 #ifdef CONFIG_ARM64_MTE
679 		[ilog2(VM_MTE)]		= "mt",
680 		[ilog2(VM_MTE_ALLOWED)]	= "",
681 #endif
682 #ifdef CONFIG_ARCH_HAS_PKEYS
683 		/* These come out via ProtectionKey: */
684 		[ilog2(VM_PKEY_BIT0)]	= "",
685 		[ilog2(VM_PKEY_BIT1)]	= "",
686 		[ilog2(VM_PKEY_BIT2)]	= "",
687 		[ilog2(VM_PKEY_BIT3)]	= "",
688 #if VM_PKEY_BIT4
689 		[ilog2(VM_PKEY_BIT4)]	= "",
690 #endif
691 #endif /* CONFIG_ARCH_HAS_PKEYS */
692 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
693 		[ilog2(VM_UFFD_MINOR)]	= "ui",
694 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
695 	};
696 	size_t i;
697 
698 	seq_puts(m, "VmFlags: ");
699 	for (i = 0; i < BITS_PER_LONG; i++) {
700 		if (!mnemonics[i][0])
701 			continue;
702 		if (vma->vm_flags & (1UL << i)) {
703 			seq_putc(m, mnemonics[i][0]);
704 			seq_putc(m, mnemonics[i][1]);
705 			seq_putc(m, ' ');
706 		}
707 	}
708 	seq_putc(m, '\n');
709 }
710 
711 #ifdef CONFIG_HUGETLB_PAGE
712 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
713 				 unsigned long addr, unsigned long end,
714 				 struct mm_walk *walk)
715 {
716 	struct mem_size_stats *mss = walk->private;
717 	struct vm_area_struct *vma = walk->vma;
718 	struct page *page = NULL;
719 	pte_t ptent = ptep_get(pte);
720 
721 	if (pte_present(ptent)) {
722 		page = vm_normal_page(vma, addr, ptent);
723 	} else if (is_swap_pte(ptent)) {
724 		swp_entry_t swpent = pte_to_swp_entry(ptent);
725 
726 		if (is_pfn_swap_entry(swpent))
727 			page = pfn_swap_entry_to_page(swpent);
728 	}
729 	if (page) {
730 		if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
731 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
732 		else
733 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
734 	}
735 	return 0;
736 }
737 #else
738 #define smaps_hugetlb_range	NULL
739 #endif /* HUGETLB_PAGE */
740 
741 static const struct mm_walk_ops smaps_walk_ops = {
742 	.pmd_entry		= smaps_pte_range,
743 	.hugetlb_entry		= smaps_hugetlb_range,
744 	.walk_lock		= PGWALK_RDLOCK,
745 };
746 
747 static const struct mm_walk_ops smaps_shmem_walk_ops = {
748 	.pmd_entry		= smaps_pte_range,
749 	.hugetlb_entry		= smaps_hugetlb_range,
750 	.pte_hole		= smaps_pte_hole,
751 	.walk_lock		= PGWALK_RDLOCK,
752 };
753 
754 /*
755  * Gather mem stats from @vma with the indicated beginning
756  * address @start, and keep them in @mss.
757  *
758  * Use vm_start of @vma as the beginning address if @start is 0.
759  */
760 static void smap_gather_stats(struct vm_area_struct *vma,
761 		struct mem_size_stats *mss, unsigned long start)
762 {
763 	const struct mm_walk_ops *ops = &smaps_walk_ops;
764 
765 	/* Invalid start */
766 	if (start >= vma->vm_end)
767 		return;
768 
769 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
770 		/*
771 		 * For shared or readonly shmem mappings we know that all
772 		 * swapped out pages belong to the shmem object, and we can
773 		 * obtain the swap value much more efficiently. For private
774 		 * writable mappings, we might have COW pages that are
775 		 * not affected by the parent swapped out pages of the shmem
776 		 * object, so we have to distinguish them during the page walk.
777 		 * Unless we know that the shmem object (or the part mapped by
778 		 * our VMA) has no swapped out pages at all.
779 		 */
780 		unsigned long shmem_swapped = shmem_swap_usage(vma);
781 
782 		if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
783 					!(vma->vm_flags & VM_WRITE))) {
784 			mss->swap += shmem_swapped;
785 		} else {
786 			ops = &smaps_shmem_walk_ops;
787 		}
788 	}
789 
790 	/* mmap_lock is held in m_start */
791 	if (!start)
792 		walk_page_vma(vma, ops, mss);
793 	else
794 		walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
795 }
796 
797 #define SEQ_PUT_DEC(str, val) \
798 		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
799 
800 /* Show the contents common for smaps and smaps_rollup */
801 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
802 	bool rollup_mode)
803 {
804 	SEQ_PUT_DEC("Rss:            ", mss->resident);
805 	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
806 	SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> PSS_SHIFT);
807 	if (rollup_mode) {
808 		/*
809 		 * These are meaningful only for smaps_rollup, otherwise two of
810 		 * them are zero, and the other one is the same as Pss.
811 		 */
812 		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
813 			mss->pss_anon >> PSS_SHIFT);
814 		SEQ_PUT_DEC(" kB\nPss_File:       ",
815 			mss->pss_file >> PSS_SHIFT);
816 		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
817 			mss->pss_shmem >> PSS_SHIFT);
818 	}
819 	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
820 	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
821 	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
822 	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
823 	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
824 	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
825 	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
826 	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
827 	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
828 	SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
829 	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
830 	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
831 				  mss->private_hugetlb >> 10, 7);
832 	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
833 	SEQ_PUT_DEC(" kB\nSwapPss:        ",
834 					mss->swap_pss >> PSS_SHIFT);
835 	SEQ_PUT_DEC(" kB\nLocked:         ",
836 					mss->pss_locked >> PSS_SHIFT);
837 	seq_puts(m, " kB\n");
838 }
839 
840 static int show_smap(struct seq_file *m, void *v)
841 {
842 	struct vm_area_struct *vma = v;
843 	struct mem_size_stats mss;
844 
845 	memset(&mss, 0, sizeof(mss));
846 
847 	smap_gather_stats(vma, &mss, 0);
848 
849 	show_map_vma(m, vma);
850 
851 	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
852 	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
853 	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
854 	seq_puts(m, " kB\n");
855 
856 	__show_smap(m, &mss, false);
857 
858 	seq_printf(m, "THPeligible:    %8u\n",
859 		   hugepage_vma_check(vma, vma->vm_flags, true, false, true));
860 
861 	if (arch_pkeys_enabled())
862 		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
863 	show_smap_vma_flags(m, vma);
864 
865 	return 0;
866 }
867 
868 static int show_smaps_rollup(struct seq_file *m, void *v)
869 {
870 	struct proc_maps_private *priv = m->private;
871 	struct mem_size_stats mss;
872 	struct mm_struct *mm = priv->mm;
873 	struct vm_area_struct *vma;
874 	unsigned long vma_start = 0, last_vma_end = 0;
875 	int ret = 0;
876 	VMA_ITERATOR(vmi, mm, 0);
877 
878 	priv->task = get_proc_task(priv->inode);
879 	if (!priv->task)
880 		return -ESRCH;
881 
882 	if (!mm || !mmget_not_zero(mm)) {
883 		ret = -ESRCH;
884 		goto out_put_task;
885 	}
886 
887 	memset(&mss, 0, sizeof(mss));
888 
889 	ret = mmap_read_lock_killable(mm);
890 	if (ret)
891 		goto out_put_mm;
892 
893 	hold_task_mempolicy(priv);
894 	vma = vma_next(&vmi);
895 
896 	if (unlikely(!vma))
897 		goto empty_set;
898 
899 	vma_start = vma->vm_start;
900 	do {
901 		smap_gather_stats(vma, &mss, 0);
902 		last_vma_end = vma->vm_end;
903 
904 		/*
905 		 * Release mmap_lock temporarily if someone wants to
906 		 * access it for write request.
907 		 */
908 		if (mmap_lock_is_contended(mm)) {
909 			vma_iter_invalidate(&vmi);
910 			mmap_read_unlock(mm);
911 			ret = mmap_read_lock_killable(mm);
912 			if (ret) {
913 				release_task_mempolicy(priv);
914 				goto out_put_mm;
915 			}
916 
917 			/*
918 			 * After dropping the lock, there are four cases to
919 			 * consider. See the following example for explanation.
920 			 *
921 			 *   +------+------+-----------+
922 			 *   | VMA1 | VMA2 | VMA3      |
923 			 *   +------+------+-----------+
924 			 *   |      |      |           |
925 			 *  4k     8k     16k         400k
926 			 *
927 			 * Suppose we drop the lock after reading VMA2 due to
928 			 * contention, then we get:
929 			 *
930 			 *	last_vma_end = 16k
931 			 *
932 			 * 1) VMA2 is freed, but VMA3 exists:
933 			 *
934 			 *    vma_next(vmi) will return VMA3.
935 			 *    In this case, just continue from VMA3.
936 			 *
937 			 * 2) VMA2 still exists:
938 			 *
939 			 *    vma_next(vmi) will return VMA3.
940 			 *    In this case, just continue from VMA3.
941 			 *
942 			 * 3) No more VMAs can be found:
943 			 *
944 			 *    vma_next(vmi) will return NULL.
945 			 *    No more things to do, just break.
946 			 *
947 			 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
948 			 *
949 			 *    vma_next(vmi) will return VMA' whose range
950 			 *    contains last_vma_end.
951 			 *    Iterate VMA' from last_vma_end.
952 			 */
953 			vma = vma_next(&vmi);
954 			/* Case 3 above */
955 			if (!vma)
956 				break;
957 
958 			/* Case 1 and 2 above */
959 			if (vma->vm_start >= last_vma_end)
960 				continue;
961 
962 			/* Case 4 above */
963 			if (vma->vm_end > last_vma_end)
964 				smap_gather_stats(vma, &mss, last_vma_end);
965 		}
966 	} for_each_vma(vmi, vma);
967 
968 empty_set:
969 	show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
970 	seq_pad(m, ' ');
971 	seq_puts(m, "[rollup]\n");
972 
973 	__show_smap(m, &mss, true);
974 
975 	release_task_mempolicy(priv);
976 	mmap_read_unlock(mm);
977 
978 out_put_mm:
979 	mmput(mm);
980 out_put_task:
981 	put_task_struct(priv->task);
982 	priv->task = NULL;
983 
984 	return ret;
985 }
986 #undef SEQ_PUT_DEC
987 
988 static const struct seq_operations proc_pid_smaps_op = {
989 	.start	= m_start,
990 	.next	= m_next,
991 	.stop	= m_stop,
992 	.show	= show_smap
993 };
994 
995 static int pid_smaps_open(struct inode *inode, struct file *file)
996 {
997 	return do_maps_open(inode, file, &proc_pid_smaps_op);
998 }
999 
1000 static int smaps_rollup_open(struct inode *inode, struct file *file)
1001 {
1002 	int ret;
1003 	struct proc_maps_private *priv;
1004 
1005 	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1006 	if (!priv)
1007 		return -ENOMEM;
1008 
1009 	ret = single_open(file, show_smaps_rollup, priv);
1010 	if (ret)
1011 		goto out_free;
1012 
1013 	priv->inode = inode;
1014 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1015 	if (IS_ERR(priv->mm)) {
1016 		ret = PTR_ERR(priv->mm);
1017 
1018 		single_release(inode, file);
1019 		goto out_free;
1020 	}
1021 
1022 	return 0;
1023 
1024 out_free:
1025 	kfree(priv);
1026 	return ret;
1027 }
1028 
1029 static int smaps_rollup_release(struct inode *inode, struct file *file)
1030 {
1031 	struct seq_file *seq = file->private_data;
1032 	struct proc_maps_private *priv = seq->private;
1033 
1034 	if (priv->mm)
1035 		mmdrop(priv->mm);
1036 
1037 	kfree(priv);
1038 	return single_release(inode, file);
1039 }
1040 
1041 const struct file_operations proc_pid_smaps_operations = {
1042 	.open		= pid_smaps_open,
1043 	.read		= seq_read,
1044 	.llseek		= seq_lseek,
1045 	.release	= proc_map_release,
1046 };
1047 
1048 const struct file_operations proc_pid_smaps_rollup_operations = {
1049 	.open		= smaps_rollup_open,
1050 	.read		= seq_read,
1051 	.llseek		= seq_lseek,
1052 	.release	= smaps_rollup_release,
1053 };
1054 
1055 enum clear_refs_types {
1056 	CLEAR_REFS_ALL = 1,
1057 	CLEAR_REFS_ANON,
1058 	CLEAR_REFS_MAPPED,
1059 	CLEAR_REFS_SOFT_DIRTY,
1060 	CLEAR_REFS_MM_HIWATER_RSS,
1061 	CLEAR_REFS_LAST,
1062 };
1063 
1064 struct clear_refs_private {
1065 	enum clear_refs_types type;
1066 };
1067 
1068 #ifdef CONFIG_MEM_SOFT_DIRTY
1069 
1070 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1071 {
1072 	struct page *page;
1073 
1074 	if (!pte_write(pte))
1075 		return false;
1076 	if (!is_cow_mapping(vma->vm_flags))
1077 		return false;
1078 	if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1079 		return false;
1080 	page = vm_normal_page(vma, addr, pte);
1081 	if (!page)
1082 		return false;
1083 	return page_maybe_dma_pinned(page);
1084 }
1085 
1086 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1087 		unsigned long addr, pte_t *pte)
1088 {
1089 	/*
1090 	 * The soft-dirty tracker uses #PF-s to catch writes
1091 	 * to pages, so write-protect the pte as well. See the
1092 	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
1093 	 * of how soft-dirty works.
1094 	 */
1095 	pte_t ptent = ptep_get(pte);
1096 
1097 	if (pte_present(ptent)) {
1098 		pte_t old_pte;
1099 
1100 		if (pte_is_pinned(vma, addr, ptent))
1101 			return;
1102 		old_pte = ptep_modify_prot_start(vma, addr, pte);
1103 		ptent = pte_wrprotect(old_pte);
1104 		ptent = pte_clear_soft_dirty(ptent);
1105 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1106 	} else if (is_swap_pte(ptent)) {
1107 		ptent = pte_swp_clear_soft_dirty(ptent);
1108 		set_pte_at(vma->vm_mm, addr, pte, ptent);
1109 	}
1110 }
1111 #else
1112 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1113 		unsigned long addr, pte_t *pte)
1114 {
1115 }
1116 #endif
1117 
1118 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1119 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1120 		unsigned long addr, pmd_t *pmdp)
1121 {
1122 	pmd_t old, pmd = *pmdp;
1123 
1124 	if (pmd_present(pmd)) {
1125 		/* See comment in change_huge_pmd() */
1126 		old = pmdp_invalidate(vma, addr, pmdp);
1127 		if (pmd_dirty(old))
1128 			pmd = pmd_mkdirty(pmd);
1129 		if (pmd_young(old))
1130 			pmd = pmd_mkyoung(pmd);
1131 
1132 		pmd = pmd_wrprotect(pmd);
1133 		pmd = pmd_clear_soft_dirty(pmd);
1134 
1135 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1136 	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1137 		pmd = pmd_swp_clear_soft_dirty(pmd);
1138 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1139 	}
1140 }
1141 #else
1142 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1143 		unsigned long addr, pmd_t *pmdp)
1144 {
1145 }
1146 #endif
1147 
1148 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1149 				unsigned long end, struct mm_walk *walk)
1150 {
1151 	struct clear_refs_private *cp = walk->private;
1152 	struct vm_area_struct *vma = walk->vma;
1153 	pte_t *pte, ptent;
1154 	spinlock_t *ptl;
1155 	struct page *page;
1156 
1157 	ptl = pmd_trans_huge_lock(pmd, vma);
1158 	if (ptl) {
1159 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1160 			clear_soft_dirty_pmd(vma, addr, pmd);
1161 			goto out;
1162 		}
1163 
1164 		if (!pmd_present(*pmd))
1165 			goto out;
1166 
1167 		page = pmd_page(*pmd);
1168 
1169 		/* Clear accessed and referenced bits. */
1170 		pmdp_test_and_clear_young(vma, addr, pmd);
1171 		test_and_clear_page_young(page);
1172 		ClearPageReferenced(page);
1173 out:
1174 		spin_unlock(ptl);
1175 		return 0;
1176 	}
1177 
1178 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1179 	if (!pte) {
1180 		walk->action = ACTION_AGAIN;
1181 		return 0;
1182 	}
1183 	for (; addr != end; pte++, addr += PAGE_SIZE) {
1184 		ptent = ptep_get(pte);
1185 
1186 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1187 			clear_soft_dirty(vma, addr, pte);
1188 			continue;
1189 		}
1190 
1191 		if (!pte_present(ptent))
1192 			continue;
1193 
1194 		page = vm_normal_page(vma, addr, ptent);
1195 		if (!page)
1196 			continue;
1197 
1198 		/* Clear accessed and referenced bits. */
1199 		ptep_test_and_clear_young(vma, addr, pte);
1200 		test_and_clear_page_young(page);
1201 		ClearPageReferenced(page);
1202 	}
1203 	pte_unmap_unlock(pte - 1, ptl);
1204 	cond_resched();
1205 	return 0;
1206 }
1207 
1208 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1209 				struct mm_walk *walk)
1210 {
1211 	struct clear_refs_private *cp = walk->private;
1212 	struct vm_area_struct *vma = walk->vma;
1213 
1214 	if (vma->vm_flags & VM_PFNMAP)
1215 		return 1;
1216 
1217 	/*
1218 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1219 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1220 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1221 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1222 	 */
1223 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1224 		return 1;
1225 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1226 		return 1;
1227 	return 0;
1228 }
1229 
1230 static const struct mm_walk_ops clear_refs_walk_ops = {
1231 	.pmd_entry		= clear_refs_pte_range,
1232 	.test_walk		= clear_refs_test_walk,
1233 	.walk_lock		= PGWALK_WRLOCK,
1234 };
1235 
1236 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1237 				size_t count, loff_t *ppos)
1238 {
1239 	struct task_struct *task;
1240 	char buffer[PROC_NUMBUF];
1241 	struct mm_struct *mm;
1242 	struct vm_area_struct *vma;
1243 	enum clear_refs_types type;
1244 	int itype;
1245 	int rv;
1246 
1247 	memset(buffer, 0, sizeof(buffer));
1248 	if (count > sizeof(buffer) - 1)
1249 		count = sizeof(buffer) - 1;
1250 	if (copy_from_user(buffer, buf, count))
1251 		return -EFAULT;
1252 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1253 	if (rv < 0)
1254 		return rv;
1255 	type = (enum clear_refs_types)itype;
1256 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1257 		return -EINVAL;
1258 
1259 	task = get_proc_task(file_inode(file));
1260 	if (!task)
1261 		return -ESRCH;
1262 	mm = get_task_mm(task);
1263 	if (mm) {
1264 		VMA_ITERATOR(vmi, mm, 0);
1265 		struct mmu_notifier_range range;
1266 		struct clear_refs_private cp = {
1267 			.type = type,
1268 		};
1269 
1270 		if (mmap_write_lock_killable(mm)) {
1271 			count = -EINTR;
1272 			goto out_mm;
1273 		}
1274 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1275 			/*
1276 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1277 			 * resident set size to this mm's current rss value.
1278 			 */
1279 			reset_mm_hiwater_rss(mm);
1280 			goto out_unlock;
1281 		}
1282 
1283 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1284 			for_each_vma(vmi, vma) {
1285 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1286 					continue;
1287 				vm_flags_clear(vma, VM_SOFTDIRTY);
1288 				vma_set_page_prot(vma);
1289 			}
1290 
1291 			inc_tlb_flush_pending(mm);
1292 			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1293 						0, mm, 0, -1UL);
1294 			mmu_notifier_invalidate_range_start(&range);
1295 		}
1296 		walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
1297 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1298 			mmu_notifier_invalidate_range_end(&range);
1299 			flush_tlb_mm(mm);
1300 			dec_tlb_flush_pending(mm);
1301 		}
1302 out_unlock:
1303 		mmap_write_unlock(mm);
1304 out_mm:
1305 		mmput(mm);
1306 	}
1307 	put_task_struct(task);
1308 
1309 	return count;
1310 }
1311 
1312 const struct file_operations proc_clear_refs_operations = {
1313 	.write		= clear_refs_write,
1314 	.llseek		= noop_llseek,
1315 };
1316 
1317 typedef struct {
1318 	u64 pme;
1319 } pagemap_entry_t;
1320 
1321 struct pagemapread {
1322 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1323 	pagemap_entry_t *buffer;
1324 	bool show_pfn;
1325 };
1326 
1327 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1328 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1329 
1330 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1331 #define PM_PFRAME_BITS		55
1332 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1333 #define PM_SOFT_DIRTY		BIT_ULL(55)
1334 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1335 #define PM_UFFD_WP		BIT_ULL(57)
1336 #define PM_FILE			BIT_ULL(61)
1337 #define PM_SWAP			BIT_ULL(62)
1338 #define PM_PRESENT		BIT_ULL(63)
1339 
1340 #define PM_END_OF_BUFFER    1
1341 
1342 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1343 {
1344 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1345 }
1346 
1347 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1348 			  struct pagemapread *pm)
1349 {
1350 	pm->buffer[pm->pos++] = *pme;
1351 	if (pm->pos >= pm->len)
1352 		return PM_END_OF_BUFFER;
1353 	return 0;
1354 }
1355 
1356 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1357 			    __always_unused int depth, struct mm_walk *walk)
1358 {
1359 	struct pagemapread *pm = walk->private;
1360 	unsigned long addr = start;
1361 	int err = 0;
1362 
1363 	while (addr < end) {
1364 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1365 		pagemap_entry_t pme = make_pme(0, 0);
1366 		/* End of address space hole, which we mark as non-present. */
1367 		unsigned long hole_end;
1368 
1369 		if (vma)
1370 			hole_end = min(end, vma->vm_start);
1371 		else
1372 			hole_end = end;
1373 
1374 		for (; addr < hole_end; addr += PAGE_SIZE) {
1375 			err = add_to_pagemap(addr, &pme, pm);
1376 			if (err)
1377 				goto out;
1378 		}
1379 
1380 		if (!vma)
1381 			break;
1382 
1383 		/* Addresses in the VMA. */
1384 		if (vma->vm_flags & VM_SOFTDIRTY)
1385 			pme = make_pme(0, PM_SOFT_DIRTY);
1386 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1387 			err = add_to_pagemap(addr, &pme, pm);
1388 			if (err)
1389 				goto out;
1390 		}
1391 	}
1392 out:
1393 	return err;
1394 }
1395 
1396 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1397 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1398 {
1399 	u64 frame = 0, flags = 0;
1400 	struct page *page = NULL;
1401 	bool migration = false;
1402 
1403 	if (pte_present(pte)) {
1404 		if (pm->show_pfn)
1405 			frame = pte_pfn(pte);
1406 		flags |= PM_PRESENT;
1407 		page = vm_normal_page(vma, addr, pte);
1408 		if (pte_soft_dirty(pte))
1409 			flags |= PM_SOFT_DIRTY;
1410 		if (pte_uffd_wp(pte))
1411 			flags |= PM_UFFD_WP;
1412 	} else if (is_swap_pte(pte)) {
1413 		swp_entry_t entry;
1414 		if (pte_swp_soft_dirty(pte))
1415 			flags |= PM_SOFT_DIRTY;
1416 		if (pte_swp_uffd_wp(pte))
1417 			flags |= PM_UFFD_WP;
1418 		entry = pte_to_swp_entry(pte);
1419 		if (pm->show_pfn) {
1420 			pgoff_t offset;
1421 			/*
1422 			 * For PFN swap offsets, keeping the offset field
1423 			 * to be PFN only to be compatible with old smaps.
1424 			 */
1425 			if (is_pfn_swap_entry(entry))
1426 				offset = swp_offset_pfn(entry);
1427 			else
1428 				offset = swp_offset(entry);
1429 			frame = swp_type(entry) |
1430 			    (offset << MAX_SWAPFILES_SHIFT);
1431 		}
1432 		flags |= PM_SWAP;
1433 		migration = is_migration_entry(entry);
1434 		if (is_pfn_swap_entry(entry))
1435 			page = pfn_swap_entry_to_page(entry);
1436 		if (pte_marker_entry_uffd_wp(entry))
1437 			flags |= PM_UFFD_WP;
1438 	}
1439 
1440 	if (page && !PageAnon(page))
1441 		flags |= PM_FILE;
1442 	if (page && !migration && page_mapcount(page) == 1)
1443 		flags |= PM_MMAP_EXCLUSIVE;
1444 	if (vma->vm_flags & VM_SOFTDIRTY)
1445 		flags |= PM_SOFT_DIRTY;
1446 
1447 	return make_pme(frame, flags);
1448 }
1449 
1450 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1451 			     struct mm_walk *walk)
1452 {
1453 	struct vm_area_struct *vma = walk->vma;
1454 	struct pagemapread *pm = walk->private;
1455 	spinlock_t *ptl;
1456 	pte_t *pte, *orig_pte;
1457 	int err = 0;
1458 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1459 	bool migration = false;
1460 
1461 	ptl = pmd_trans_huge_lock(pmdp, vma);
1462 	if (ptl) {
1463 		u64 flags = 0, frame = 0;
1464 		pmd_t pmd = *pmdp;
1465 		struct page *page = NULL;
1466 
1467 		if (vma->vm_flags & VM_SOFTDIRTY)
1468 			flags |= PM_SOFT_DIRTY;
1469 
1470 		if (pmd_present(pmd)) {
1471 			page = pmd_page(pmd);
1472 
1473 			flags |= PM_PRESENT;
1474 			if (pmd_soft_dirty(pmd))
1475 				flags |= PM_SOFT_DIRTY;
1476 			if (pmd_uffd_wp(pmd))
1477 				flags |= PM_UFFD_WP;
1478 			if (pm->show_pfn)
1479 				frame = pmd_pfn(pmd) +
1480 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1481 		}
1482 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1483 		else if (is_swap_pmd(pmd)) {
1484 			swp_entry_t entry = pmd_to_swp_entry(pmd);
1485 			unsigned long offset;
1486 
1487 			if (pm->show_pfn) {
1488 				if (is_pfn_swap_entry(entry))
1489 					offset = swp_offset_pfn(entry);
1490 				else
1491 					offset = swp_offset(entry);
1492 				offset = offset +
1493 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1494 				frame = swp_type(entry) |
1495 					(offset << MAX_SWAPFILES_SHIFT);
1496 			}
1497 			flags |= PM_SWAP;
1498 			if (pmd_swp_soft_dirty(pmd))
1499 				flags |= PM_SOFT_DIRTY;
1500 			if (pmd_swp_uffd_wp(pmd))
1501 				flags |= PM_UFFD_WP;
1502 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1503 			migration = is_migration_entry(entry);
1504 			page = pfn_swap_entry_to_page(entry);
1505 		}
1506 #endif
1507 
1508 		if (page && !migration && page_mapcount(page) == 1)
1509 			flags |= PM_MMAP_EXCLUSIVE;
1510 
1511 		for (; addr != end; addr += PAGE_SIZE) {
1512 			pagemap_entry_t pme = make_pme(frame, flags);
1513 
1514 			err = add_to_pagemap(addr, &pme, pm);
1515 			if (err)
1516 				break;
1517 			if (pm->show_pfn) {
1518 				if (flags & PM_PRESENT)
1519 					frame++;
1520 				else if (flags & PM_SWAP)
1521 					frame += (1 << MAX_SWAPFILES_SHIFT);
1522 			}
1523 		}
1524 		spin_unlock(ptl);
1525 		return err;
1526 	}
1527 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1528 
1529 	/*
1530 	 * We can assume that @vma always points to a valid one and @end never
1531 	 * goes beyond vma->vm_end.
1532 	 */
1533 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1534 	if (!pte) {
1535 		walk->action = ACTION_AGAIN;
1536 		return err;
1537 	}
1538 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1539 		pagemap_entry_t pme;
1540 
1541 		pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
1542 		err = add_to_pagemap(addr, &pme, pm);
1543 		if (err)
1544 			break;
1545 	}
1546 	pte_unmap_unlock(orig_pte, ptl);
1547 
1548 	cond_resched();
1549 
1550 	return err;
1551 }
1552 
1553 #ifdef CONFIG_HUGETLB_PAGE
1554 /* This function walks within one hugetlb entry in the single call */
1555 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1556 				 unsigned long addr, unsigned long end,
1557 				 struct mm_walk *walk)
1558 {
1559 	struct pagemapread *pm = walk->private;
1560 	struct vm_area_struct *vma = walk->vma;
1561 	u64 flags = 0, frame = 0;
1562 	int err = 0;
1563 	pte_t pte;
1564 
1565 	if (vma->vm_flags & VM_SOFTDIRTY)
1566 		flags |= PM_SOFT_DIRTY;
1567 
1568 	pte = huge_ptep_get(ptep);
1569 	if (pte_present(pte)) {
1570 		struct page *page = pte_page(pte);
1571 
1572 		if (!PageAnon(page))
1573 			flags |= PM_FILE;
1574 
1575 		if (page_mapcount(page) == 1)
1576 			flags |= PM_MMAP_EXCLUSIVE;
1577 
1578 		if (huge_pte_uffd_wp(pte))
1579 			flags |= PM_UFFD_WP;
1580 
1581 		flags |= PM_PRESENT;
1582 		if (pm->show_pfn)
1583 			frame = pte_pfn(pte) +
1584 				((addr & ~hmask) >> PAGE_SHIFT);
1585 	} else if (pte_swp_uffd_wp_any(pte)) {
1586 		flags |= PM_UFFD_WP;
1587 	}
1588 
1589 	for (; addr != end; addr += PAGE_SIZE) {
1590 		pagemap_entry_t pme = make_pme(frame, flags);
1591 
1592 		err = add_to_pagemap(addr, &pme, pm);
1593 		if (err)
1594 			return err;
1595 		if (pm->show_pfn && (flags & PM_PRESENT))
1596 			frame++;
1597 	}
1598 
1599 	cond_resched();
1600 
1601 	return err;
1602 }
1603 #else
1604 #define pagemap_hugetlb_range	NULL
1605 #endif /* HUGETLB_PAGE */
1606 
1607 static const struct mm_walk_ops pagemap_ops = {
1608 	.pmd_entry	= pagemap_pmd_range,
1609 	.pte_hole	= pagemap_pte_hole,
1610 	.hugetlb_entry	= pagemap_hugetlb_range,
1611 	.walk_lock	= PGWALK_RDLOCK,
1612 };
1613 
1614 /*
1615  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1616  *
1617  * For each page in the address space, this file contains one 64-bit entry
1618  * consisting of the following:
1619  *
1620  * Bits 0-54  page frame number (PFN) if present
1621  * Bits 0-4   swap type if swapped
1622  * Bits 5-54  swap offset if swapped
1623  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1624  * Bit  56    page exclusively mapped
1625  * Bit  57    pte is uffd-wp write-protected
1626  * Bits 58-60 zero
1627  * Bit  61    page is file-page or shared-anon
1628  * Bit  62    page swapped
1629  * Bit  63    page present
1630  *
1631  * If the page is not present but in swap, then the PFN contains an
1632  * encoding of the swap file number and the page's offset into the
1633  * swap. Unmapped pages return a null PFN. This allows determining
1634  * precisely which pages are mapped (or in swap) and comparing mapped
1635  * pages between processes.
1636  *
1637  * Efficient users of this interface will use /proc/pid/maps to
1638  * determine which areas of memory are actually mapped and llseek to
1639  * skip over unmapped regions.
1640  */
1641 static ssize_t pagemap_read(struct file *file, char __user *buf,
1642 			    size_t count, loff_t *ppos)
1643 {
1644 	struct mm_struct *mm = file->private_data;
1645 	struct pagemapread pm;
1646 	unsigned long src;
1647 	unsigned long svpfn;
1648 	unsigned long start_vaddr;
1649 	unsigned long end_vaddr;
1650 	int ret = 0, copied = 0;
1651 
1652 	if (!mm || !mmget_not_zero(mm))
1653 		goto out;
1654 
1655 	ret = -EINVAL;
1656 	/* file position must be aligned */
1657 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1658 		goto out_mm;
1659 
1660 	ret = 0;
1661 	if (!count)
1662 		goto out_mm;
1663 
1664 	/* do not disclose physical addresses: attack vector */
1665 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1666 
1667 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1668 	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1669 	ret = -ENOMEM;
1670 	if (!pm.buffer)
1671 		goto out_mm;
1672 
1673 	src = *ppos;
1674 	svpfn = src / PM_ENTRY_BYTES;
1675 	end_vaddr = mm->task_size;
1676 
1677 	/* watch out for wraparound */
1678 	start_vaddr = end_vaddr;
1679 	if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
1680 		unsigned long end;
1681 
1682 		ret = mmap_read_lock_killable(mm);
1683 		if (ret)
1684 			goto out_free;
1685 		start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1686 		mmap_read_unlock(mm);
1687 
1688 		end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1689 		if (end >= start_vaddr && end < mm->task_size)
1690 			end_vaddr = end;
1691 	}
1692 
1693 	/* Ensure the address is inside the task */
1694 	if (start_vaddr > mm->task_size)
1695 		start_vaddr = end_vaddr;
1696 
1697 	ret = 0;
1698 	while (count && (start_vaddr < end_vaddr)) {
1699 		int len;
1700 		unsigned long end;
1701 
1702 		pm.pos = 0;
1703 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1704 		/* overflow ? */
1705 		if (end < start_vaddr || end > end_vaddr)
1706 			end = end_vaddr;
1707 		ret = mmap_read_lock_killable(mm);
1708 		if (ret)
1709 			goto out_free;
1710 		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1711 		mmap_read_unlock(mm);
1712 		start_vaddr = end;
1713 
1714 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1715 		if (copy_to_user(buf, pm.buffer, len)) {
1716 			ret = -EFAULT;
1717 			goto out_free;
1718 		}
1719 		copied += len;
1720 		buf += len;
1721 		count -= len;
1722 	}
1723 	*ppos += copied;
1724 	if (!ret || ret == PM_END_OF_BUFFER)
1725 		ret = copied;
1726 
1727 out_free:
1728 	kfree(pm.buffer);
1729 out_mm:
1730 	mmput(mm);
1731 out:
1732 	return ret;
1733 }
1734 
1735 static int pagemap_open(struct inode *inode, struct file *file)
1736 {
1737 	struct mm_struct *mm;
1738 
1739 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1740 	if (IS_ERR(mm))
1741 		return PTR_ERR(mm);
1742 	file->private_data = mm;
1743 	return 0;
1744 }
1745 
1746 static int pagemap_release(struct inode *inode, struct file *file)
1747 {
1748 	struct mm_struct *mm = file->private_data;
1749 
1750 	if (mm)
1751 		mmdrop(mm);
1752 	return 0;
1753 }
1754 
1755 const struct file_operations proc_pagemap_operations = {
1756 	.llseek		= mem_lseek, /* borrow this */
1757 	.read		= pagemap_read,
1758 	.open		= pagemap_open,
1759 	.release	= pagemap_release,
1760 };
1761 #endif /* CONFIG_PROC_PAGE_MONITOR */
1762 
1763 #ifdef CONFIG_NUMA
1764 
1765 struct numa_maps {
1766 	unsigned long pages;
1767 	unsigned long anon;
1768 	unsigned long active;
1769 	unsigned long writeback;
1770 	unsigned long mapcount_max;
1771 	unsigned long dirty;
1772 	unsigned long swapcache;
1773 	unsigned long node[MAX_NUMNODES];
1774 };
1775 
1776 struct numa_maps_private {
1777 	struct proc_maps_private proc_maps;
1778 	struct numa_maps md;
1779 };
1780 
1781 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1782 			unsigned long nr_pages)
1783 {
1784 	int count = page_mapcount(page);
1785 
1786 	md->pages += nr_pages;
1787 	if (pte_dirty || PageDirty(page))
1788 		md->dirty += nr_pages;
1789 
1790 	if (PageSwapCache(page))
1791 		md->swapcache += nr_pages;
1792 
1793 	if (PageActive(page) || PageUnevictable(page))
1794 		md->active += nr_pages;
1795 
1796 	if (PageWriteback(page))
1797 		md->writeback += nr_pages;
1798 
1799 	if (PageAnon(page))
1800 		md->anon += nr_pages;
1801 
1802 	if (count > md->mapcount_max)
1803 		md->mapcount_max = count;
1804 
1805 	md->node[page_to_nid(page)] += nr_pages;
1806 }
1807 
1808 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1809 		unsigned long addr)
1810 {
1811 	struct page *page;
1812 	int nid;
1813 
1814 	if (!pte_present(pte))
1815 		return NULL;
1816 
1817 	page = vm_normal_page(vma, addr, pte);
1818 	if (!page || is_zone_device_page(page))
1819 		return NULL;
1820 
1821 	if (PageReserved(page))
1822 		return NULL;
1823 
1824 	nid = page_to_nid(page);
1825 	if (!node_isset(nid, node_states[N_MEMORY]))
1826 		return NULL;
1827 
1828 	return page;
1829 }
1830 
1831 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1832 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1833 					      struct vm_area_struct *vma,
1834 					      unsigned long addr)
1835 {
1836 	struct page *page;
1837 	int nid;
1838 
1839 	if (!pmd_present(pmd))
1840 		return NULL;
1841 
1842 	page = vm_normal_page_pmd(vma, addr, pmd);
1843 	if (!page)
1844 		return NULL;
1845 
1846 	if (PageReserved(page))
1847 		return NULL;
1848 
1849 	nid = page_to_nid(page);
1850 	if (!node_isset(nid, node_states[N_MEMORY]))
1851 		return NULL;
1852 
1853 	return page;
1854 }
1855 #endif
1856 
1857 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1858 		unsigned long end, struct mm_walk *walk)
1859 {
1860 	struct numa_maps *md = walk->private;
1861 	struct vm_area_struct *vma = walk->vma;
1862 	spinlock_t *ptl;
1863 	pte_t *orig_pte;
1864 	pte_t *pte;
1865 
1866 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1867 	ptl = pmd_trans_huge_lock(pmd, vma);
1868 	if (ptl) {
1869 		struct page *page;
1870 
1871 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1872 		if (page)
1873 			gather_stats(page, md, pmd_dirty(*pmd),
1874 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1875 		spin_unlock(ptl);
1876 		return 0;
1877 	}
1878 #endif
1879 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1880 	if (!pte) {
1881 		walk->action = ACTION_AGAIN;
1882 		return 0;
1883 	}
1884 	do {
1885 		pte_t ptent = ptep_get(pte);
1886 		struct page *page = can_gather_numa_stats(ptent, vma, addr);
1887 		if (!page)
1888 			continue;
1889 		gather_stats(page, md, pte_dirty(ptent), 1);
1890 
1891 	} while (pte++, addr += PAGE_SIZE, addr != end);
1892 	pte_unmap_unlock(orig_pte, ptl);
1893 	cond_resched();
1894 	return 0;
1895 }
1896 #ifdef CONFIG_HUGETLB_PAGE
1897 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1898 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1899 {
1900 	pte_t huge_pte = huge_ptep_get(pte);
1901 	struct numa_maps *md;
1902 	struct page *page;
1903 
1904 	if (!pte_present(huge_pte))
1905 		return 0;
1906 
1907 	page = pte_page(huge_pte);
1908 
1909 	md = walk->private;
1910 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1911 	return 0;
1912 }
1913 
1914 #else
1915 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1916 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1917 {
1918 	return 0;
1919 }
1920 #endif
1921 
1922 static const struct mm_walk_ops show_numa_ops = {
1923 	.hugetlb_entry = gather_hugetlb_stats,
1924 	.pmd_entry = gather_pte_stats,
1925 	.walk_lock = PGWALK_RDLOCK,
1926 };
1927 
1928 /*
1929  * Display pages allocated per node and memory policy via /proc.
1930  */
1931 static int show_numa_map(struct seq_file *m, void *v)
1932 {
1933 	struct numa_maps_private *numa_priv = m->private;
1934 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1935 	struct vm_area_struct *vma = v;
1936 	struct numa_maps *md = &numa_priv->md;
1937 	struct file *file = vma->vm_file;
1938 	struct mm_struct *mm = vma->vm_mm;
1939 	struct mempolicy *pol;
1940 	char buffer[64];
1941 	int nid;
1942 
1943 	if (!mm)
1944 		return 0;
1945 
1946 	/* Ensure we start with an empty set of numa_maps statistics. */
1947 	memset(md, 0, sizeof(*md));
1948 
1949 	pol = __get_vma_policy(vma, vma->vm_start);
1950 	if (pol) {
1951 		mpol_to_str(buffer, sizeof(buffer), pol);
1952 		mpol_cond_put(pol);
1953 	} else {
1954 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1955 	}
1956 
1957 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1958 
1959 	if (file) {
1960 		seq_puts(m, " file=");
1961 		seq_file_path(m, file, "\n\t= ");
1962 	} else if (vma_is_initial_heap(vma)) {
1963 		seq_puts(m, " heap");
1964 	} else if (vma_is_initial_stack(vma)) {
1965 		seq_puts(m, " stack");
1966 	}
1967 
1968 	if (is_vm_hugetlb_page(vma))
1969 		seq_puts(m, " huge");
1970 
1971 	/* mmap_lock is held by m_start */
1972 	walk_page_vma(vma, &show_numa_ops, md);
1973 
1974 	if (!md->pages)
1975 		goto out;
1976 
1977 	if (md->anon)
1978 		seq_printf(m, " anon=%lu", md->anon);
1979 
1980 	if (md->dirty)
1981 		seq_printf(m, " dirty=%lu", md->dirty);
1982 
1983 	if (md->pages != md->anon && md->pages != md->dirty)
1984 		seq_printf(m, " mapped=%lu", md->pages);
1985 
1986 	if (md->mapcount_max > 1)
1987 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1988 
1989 	if (md->swapcache)
1990 		seq_printf(m, " swapcache=%lu", md->swapcache);
1991 
1992 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1993 		seq_printf(m, " active=%lu", md->active);
1994 
1995 	if (md->writeback)
1996 		seq_printf(m, " writeback=%lu", md->writeback);
1997 
1998 	for_each_node_state(nid, N_MEMORY)
1999 		if (md->node[nid])
2000 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
2001 
2002 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
2003 out:
2004 	seq_putc(m, '\n');
2005 	return 0;
2006 }
2007 
2008 static const struct seq_operations proc_pid_numa_maps_op = {
2009 	.start  = m_start,
2010 	.next   = m_next,
2011 	.stop   = m_stop,
2012 	.show   = show_numa_map,
2013 };
2014 
2015 static int pid_numa_maps_open(struct inode *inode, struct file *file)
2016 {
2017 	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2018 				sizeof(struct numa_maps_private));
2019 }
2020 
2021 const struct file_operations proc_pid_numa_maps_operations = {
2022 	.open		= pid_numa_maps_open,
2023 	.read		= seq_read,
2024 	.llseek		= seq_lseek,
2025 	.release	= proc_map_release,
2026 };
2027 
2028 #endif /* CONFIG_NUMA */
2029