xref: /openbmc/linux/fs/proc/task_mmu.c (revision eb3fcf00)
1 #include <linux/mm.h>
2 #include <linux/vmacache.h>
3 #include <linux/hugetlb.h>
4 #include <linux/huge_mm.h>
5 #include <linux/mount.h>
6 #include <linux/seq_file.h>
7 #include <linux/highmem.h>
8 #include <linux/ptrace.h>
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
11 #include <linux/mempolicy.h>
12 #include <linux/rmap.h>
13 #include <linux/swap.h>
14 #include <linux/swapops.h>
15 #include <linux/mmu_notifier.h>
16 #include <linux/page_idle.h>
17 
18 #include <asm/elf.h>
19 #include <asm/uaccess.h>
20 #include <asm/tlbflush.h>
21 #include "internal.h"
22 
23 void task_mem(struct seq_file *m, struct mm_struct *mm)
24 {
25 	unsigned long data, text, lib, swap, ptes, pmds;
26 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
27 
28 	/*
29 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
30 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
31 	 * collector of these hiwater stats must therefore get total_vm
32 	 * and rss too, which will usually be the higher.  Barriers? not
33 	 * worth the effort, such snapshots can always be inconsistent.
34 	 */
35 	hiwater_vm = total_vm = mm->total_vm;
36 	if (hiwater_vm < mm->hiwater_vm)
37 		hiwater_vm = mm->hiwater_vm;
38 	hiwater_rss = total_rss = get_mm_rss(mm);
39 	if (hiwater_rss < mm->hiwater_rss)
40 		hiwater_rss = mm->hiwater_rss;
41 
42 	data = mm->total_vm - mm->shared_vm - mm->stack_vm;
43 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
44 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
45 	swap = get_mm_counter(mm, MM_SWAPENTS);
46 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
47 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
48 	seq_printf(m,
49 		"VmPeak:\t%8lu kB\n"
50 		"VmSize:\t%8lu kB\n"
51 		"VmLck:\t%8lu kB\n"
52 		"VmPin:\t%8lu kB\n"
53 		"VmHWM:\t%8lu kB\n"
54 		"VmRSS:\t%8lu kB\n"
55 		"VmData:\t%8lu kB\n"
56 		"VmStk:\t%8lu kB\n"
57 		"VmExe:\t%8lu kB\n"
58 		"VmLib:\t%8lu kB\n"
59 		"VmPTE:\t%8lu kB\n"
60 		"VmPMD:\t%8lu kB\n"
61 		"VmSwap:\t%8lu kB\n",
62 		hiwater_vm << (PAGE_SHIFT-10),
63 		total_vm << (PAGE_SHIFT-10),
64 		mm->locked_vm << (PAGE_SHIFT-10),
65 		mm->pinned_vm << (PAGE_SHIFT-10),
66 		hiwater_rss << (PAGE_SHIFT-10),
67 		total_rss << (PAGE_SHIFT-10),
68 		data << (PAGE_SHIFT-10),
69 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
70 		ptes >> 10,
71 		pmds >> 10,
72 		swap << (PAGE_SHIFT-10));
73 }
74 
75 unsigned long task_vsize(struct mm_struct *mm)
76 {
77 	return PAGE_SIZE * mm->total_vm;
78 }
79 
80 unsigned long task_statm(struct mm_struct *mm,
81 			 unsigned long *shared, unsigned long *text,
82 			 unsigned long *data, unsigned long *resident)
83 {
84 	*shared = get_mm_counter(mm, MM_FILEPAGES);
85 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
86 								>> PAGE_SHIFT;
87 	*data = mm->total_vm - mm->shared_vm;
88 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
89 	return mm->total_vm;
90 }
91 
92 #ifdef CONFIG_NUMA
93 /*
94  * Save get_task_policy() for show_numa_map().
95  */
96 static void hold_task_mempolicy(struct proc_maps_private *priv)
97 {
98 	struct task_struct *task = priv->task;
99 
100 	task_lock(task);
101 	priv->task_mempolicy = get_task_policy(task);
102 	mpol_get(priv->task_mempolicy);
103 	task_unlock(task);
104 }
105 static void release_task_mempolicy(struct proc_maps_private *priv)
106 {
107 	mpol_put(priv->task_mempolicy);
108 }
109 #else
110 static void hold_task_mempolicy(struct proc_maps_private *priv)
111 {
112 }
113 static void release_task_mempolicy(struct proc_maps_private *priv)
114 {
115 }
116 #endif
117 
118 static void vma_stop(struct proc_maps_private *priv)
119 {
120 	struct mm_struct *mm = priv->mm;
121 
122 	release_task_mempolicy(priv);
123 	up_read(&mm->mmap_sem);
124 	mmput(mm);
125 }
126 
127 static struct vm_area_struct *
128 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
129 {
130 	if (vma == priv->tail_vma)
131 		return NULL;
132 	return vma->vm_next ?: priv->tail_vma;
133 }
134 
135 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
136 {
137 	if (m->count < m->size)	/* vma is copied successfully */
138 		m->version = m_next_vma(m->private, vma) ? vma->vm_start : -1UL;
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 = m->version;
145 	struct mm_struct *mm;
146 	struct vm_area_struct *vma;
147 	unsigned int pos = *ppos;
148 
149 	/* See m_cache_vma(). Zero at the start or after lseek. */
150 	if (last_addr == -1UL)
151 		return NULL;
152 
153 	priv->task = get_proc_task(priv->inode);
154 	if (!priv->task)
155 		return ERR_PTR(-ESRCH);
156 
157 	mm = priv->mm;
158 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
159 		return NULL;
160 
161 	down_read(&mm->mmap_sem);
162 	hold_task_mempolicy(priv);
163 	priv->tail_vma = get_gate_vma(mm);
164 
165 	if (last_addr) {
166 		vma = find_vma(mm, last_addr);
167 		if (vma && (vma = m_next_vma(priv, vma)))
168 			return vma;
169 	}
170 
171 	m->version = 0;
172 	if (pos < mm->map_count) {
173 		for (vma = mm->mmap; pos; pos--) {
174 			m->version = vma->vm_start;
175 			vma = vma->vm_next;
176 		}
177 		return vma;
178 	}
179 
180 	/* we do not bother to update m->version in this case */
181 	if (pos == mm->map_count && priv->tail_vma)
182 		return priv->tail_vma;
183 
184 	vma_stop(priv);
185 	return NULL;
186 }
187 
188 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
189 {
190 	struct proc_maps_private *priv = m->private;
191 	struct vm_area_struct *next;
192 
193 	(*pos)++;
194 	next = m_next_vma(priv, v);
195 	if (!next)
196 		vma_stop(priv);
197 	return next;
198 }
199 
200 static void m_stop(struct seq_file *m, void *v)
201 {
202 	struct proc_maps_private *priv = m->private;
203 
204 	if (!IS_ERR_OR_NULL(v))
205 		vma_stop(priv);
206 	if (priv->task) {
207 		put_task_struct(priv->task);
208 		priv->task = NULL;
209 	}
210 }
211 
212 static int proc_maps_open(struct inode *inode, struct file *file,
213 			const struct seq_operations *ops, int psize)
214 {
215 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
216 
217 	if (!priv)
218 		return -ENOMEM;
219 
220 	priv->inode = inode;
221 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
222 	if (IS_ERR(priv->mm)) {
223 		int err = PTR_ERR(priv->mm);
224 
225 		seq_release_private(inode, file);
226 		return err;
227 	}
228 
229 	return 0;
230 }
231 
232 static int proc_map_release(struct inode *inode, struct file *file)
233 {
234 	struct seq_file *seq = file->private_data;
235 	struct proc_maps_private *priv = seq->private;
236 
237 	if (priv->mm)
238 		mmdrop(priv->mm);
239 
240 	return seq_release_private(inode, file);
241 }
242 
243 static int do_maps_open(struct inode *inode, struct file *file,
244 			const struct seq_operations *ops)
245 {
246 	return proc_maps_open(inode, file, ops,
247 				sizeof(struct proc_maps_private));
248 }
249 
250 static pid_t pid_of_stack(struct proc_maps_private *priv,
251 				struct vm_area_struct *vma, bool is_pid)
252 {
253 	struct inode *inode = priv->inode;
254 	struct task_struct *task;
255 	pid_t ret = 0;
256 
257 	rcu_read_lock();
258 	task = pid_task(proc_pid(inode), PIDTYPE_PID);
259 	if (task) {
260 		task = task_of_stack(task, vma, is_pid);
261 		if (task)
262 			ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
263 	}
264 	rcu_read_unlock();
265 
266 	return ret;
267 }
268 
269 static void
270 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
271 {
272 	struct mm_struct *mm = vma->vm_mm;
273 	struct file *file = vma->vm_file;
274 	struct proc_maps_private *priv = m->private;
275 	vm_flags_t flags = vma->vm_flags;
276 	unsigned long ino = 0;
277 	unsigned long long pgoff = 0;
278 	unsigned long start, end;
279 	dev_t dev = 0;
280 	const char *name = NULL;
281 
282 	if (file) {
283 		struct inode *inode = file_inode(vma->vm_file);
284 		dev = inode->i_sb->s_dev;
285 		ino = inode->i_ino;
286 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
287 	}
288 
289 	/* We don't show the stack guard page in /proc/maps */
290 	start = vma->vm_start;
291 	if (stack_guard_page_start(vma, start))
292 		start += PAGE_SIZE;
293 	end = vma->vm_end;
294 	if (stack_guard_page_end(vma, end))
295 		end -= PAGE_SIZE;
296 
297 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
298 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
299 			start,
300 			end,
301 			flags & VM_READ ? 'r' : '-',
302 			flags & VM_WRITE ? 'w' : '-',
303 			flags & VM_EXEC ? 'x' : '-',
304 			flags & VM_MAYSHARE ? 's' : 'p',
305 			pgoff,
306 			MAJOR(dev), MINOR(dev), ino);
307 
308 	/*
309 	 * Print the dentry name for named mappings, and a
310 	 * special [heap] marker for the heap:
311 	 */
312 	if (file) {
313 		seq_pad(m, ' ');
314 		seq_file_path(m, file, "\n");
315 		goto done;
316 	}
317 
318 	if (vma->vm_ops && vma->vm_ops->name) {
319 		name = vma->vm_ops->name(vma);
320 		if (name)
321 			goto done;
322 	}
323 
324 	name = arch_vma_name(vma);
325 	if (!name) {
326 		pid_t tid;
327 
328 		if (!mm) {
329 			name = "[vdso]";
330 			goto done;
331 		}
332 
333 		if (vma->vm_start <= mm->brk &&
334 		    vma->vm_end >= mm->start_brk) {
335 			name = "[heap]";
336 			goto done;
337 		}
338 
339 		tid = pid_of_stack(priv, vma, is_pid);
340 		if (tid != 0) {
341 			/*
342 			 * Thread stack in /proc/PID/task/TID/maps or
343 			 * the main process stack.
344 			 */
345 			if (!is_pid || (vma->vm_start <= mm->start_stack &&
346 			    vma->vm_end >= mm->start_stack)) {
347 				name = "[stack]";
348 			} else {
349 				/* Thread stack in /proc/PID/maps */
350 				seq_pad(m, ' ');
351 				seq_printf(m, "[stack:%d]", tid);
352 			}
353 		}
354 	}
355 
356 done:
357 	if (name) {
358 		seq_pad(m, ' ');
359 		seq_puts(m, name);
360 	}
361 	seq_putc(m, '\n');
362 }
363 
364 static int show_map(struct seq_file *m, void *v, int is_pid)
365 {
366 	show_map_vma(m, v, is_pid);
367 	m_cache_vma(m, v);
368 	return 0;
369 }
370 
371 static int show_pid_map(struct seq_file *m, void *v)
372 {
373 	return show_map(m, v, 1);
374 }
375 
376 static int show_tid_map(struct seq_file *m, void *v)
377 {
378 	return show_map(m, v, 0);
379 }
380 
381 static const struct seq_operations proc_pid_maps_op = {
382 	.start	= m_start,
383 	.next	= m_next,
384 	.stop	= m_stop,
385 	.show	= show_pid_map
386 };
387 
388 static const struct seq_operations proc_tid_maps_op = {
389 	.start	= m_start,
390 	.next	= m_next,
391 	.stop	= m_stop,
392 	.show	= show_tid_map
393 };
394 
395 static int pid_maps_open(struct inode *inode, struct file *file)
396 {
397 	return do_maps_open(inode, file, &proc_pid_maps_op);
398 }
399 
400 static int tid_maps_open(struct inode *inode, struct file *file)
401 {
402 	return do_maps_open(inode, file, &proc_tid_maps_op);
403 }
404 
405 const struct file_operations proc_pid_maps_operations = {
406 	.open		= pid_maps_open,
407 	.read		= seq_read,
408 	.llseek		= seq_lseek,
409 	.release	= proc_map_release,
410 };
411 
412 const struct file_operations proc_tid_maps_operations = {
413 	.open		= tid_maps_open,
414 	.read		= seq_read,
415 	.llseek		= seq_lseek,
416 	.release	= proc_map_release,
417 };
418 
419 /*
420  * Proportional Set Size(PSS): my share of RSS.
421  *
422  * PSS of a process is the count of pages it has in memory, where each
423  * page is divided by the number of processes sharing it.  So if a
424  * process has 1000 pages all to itself, and 1000 shared with one other
425  * process, its PSS will be 1500.
426  *
427  * To keep (accumulated) division errors low, we adopt a 64bit
428  * fixed-point pss counter to minimize division errors. So (pss >>
429  * PSS_SHIFT) would be the real byte count.
430  *
431  * A shift of 12 before division means (assuming 4K page size):
432  * 	- 1M 3-user-pages add up to 8KB errors;
433  * 	- supports mapcount up to 2^24, or 16M;
434  * 	- supports PSS up to 2^52 bytes, or 4PB.
435  */
436 #define PSS_SHIFT 12
437 
438 #ifdef CONFIG_PROC_PAGE_MONITOR
439 struct mem_size_stats {
440 	unsigned long resident;
441 	unsigned long shared_clean;
442 	unsigned long shared_dirty;
443 	unsigned long private_clean;
444 	unsigned long private_dirty;
445 	unsigned long referenced;
446 	unsigned long anonymous;
447 	unsigned long anonymous_thp;
448 	unsigned long swap;
449 	u64 pss;
450 	u64 swap_pss;
451 };
452 
453 static void smaps_account(struct mem_size_stats *mss, struct page *page,
454 		unsigned long size, bool young, bool dirty)
455 {
456 	int mapcount;
457 
458 	if (PageAnon(page))
459 		mss->anonymous += size;
460 
461 	mss->resident += size;
462 	/* Accumulate the size in pages that have been accessed. */
463 	if (young || page_is_young(page) || PageReferenced(page))
464 		mss->referenced += size;
465 	mapcount = page_mapcount(page);
466 	if (mapcount >= 2) {
467 		u64 pss_delta;
468 
469 		if (dirty || PageDirty(page))
470 			mss->shared_dirty += size;
471 		else
472 			mss->shared_clean += size;
473 		pss_delta = (u64)size << PSS_SHIFT;
474 		do_div(pss_delta, mapcount);
475 		mss->pss += pss_delta;
476 	} else {
477 		if (dirty || PageDirty(page))
478 			mss->private_dirty += size;
479 		else
480 			mss->private_clean += size;
481 		mss->pss += (u64)size << PSS_SHIFT;
482 	}
483 }
484 
485 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
486 		struct mm_walk *walk)
487 {
488 	struct mem_size_stats *mss = walk->private;
489 	struct vm_area_struct *vma = walk->vma;
490 	struct page *page = NULL;
491 
492 	if (pte_present(*pte)) {
493 		page = vm_normal_page(vma, addr, *pte);
494 	} else if (is_swap_pte(*pte)) {
495 		swp_entry_t swpent = pte_to_swp_entry(*pte);
496 
497 		if (!non_swap_entry(swpent)) {
498 			int mapcount;
499 
500 			mss->swap += PAGE_SIZE;
501 			mapcount = swp_swapcount(swpent);
502 			if (mapcount >= 2) {
503 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
504 
505 				do_div(pss_delta, mapcount);
506 				mss->swap_pss += pss_delta;
507 			} else {
508 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
509 			}
510 		} else if (is_migration_entry(swpent))
511 			page = migration_entry_to_page(swpent);
512 	}
513 
514 	if (!page)
515 		return;
516 	smaps_account(mss, page, PAGE_SIZE, pte_young(*pte), pte_dirty(*pte));
517 }
518 
519 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
520 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
521 		struct mm_walk *walk)
522 {
523 	struct mem_size_stats *mss = walk->private;
524 	struct vm_area_struct *vma = walk->vma;
525 	struct page *page;
526 
527 	/* FOLL_DUMP will return -EFAULT on huge zero page */
528 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
529 	if (IS_ERR_OR_NULL(page))
530 		return;
531 	mss->anonymous_thp += HPAGE_PMD_SIZE;
532 	smaps_account(mss, page, HPAGE_PMD_SIZE,
533 			pmd_young(*pmd), pmd_dirty(*pmd));
534 }
535 #else
536 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
537 		struct mm_walk *walk)
538 {
539 }
540 #endif
541 
542 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
543 			   struct mm_walk *walk)
544 {
545 	struct vm_area_struct *vma = walk->vma;
546 	pte_t *pte;
547 	spinlock_t *ptl;
548 
549 	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
550 		smaps_pmd_entry(pmd, addr, walk);
551 		spin_unlock(ptl);
552 		return 0;
553 	}
554 
555 	if (pmd_trans_unstable(pmd))
556 		return 0;
557 	/*
558 	 * The mmap_sem held all the way back in m_start() is what
559 	 * keeps khugepaged out of here and from collapsing things
560 	 * in here.
561 	 */
562 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
563 	for (; addr != end; pte++, addr += PAGE_SIZE)
564 		smaps_pte_entry(pte, addr, walk);
565 	pte_unmap_unlock(pte - 1, ptl);
566 	cond_resched();
567 	return 0;
568 }
569 
570 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
571 {
572 	/*
573 	 * Don't forget to update Documentation/ on changes.
574 	 */
575 	static const char mnemonics[BITS_PER_LONG][2] = {
576 		/*
577 		 * In case if we meet a flag we don't know about.
578 		 */
579 		[0 ... (BITS_PER_LONG-1)] = "??",
580 
581 		[ilog2(VM_READ)]	= "rd",
582 		[ilog2(VM_WRITE)]	= "wr",
583 		[ilog2(VM_EXEC)]	= "ex",
584 		[ilog2(VM_SHARED)]	= "sh",
585 		[ilog2(VM_MAYREAD)]	= "mr",
586 		[ilog2(VM_MAYWRITE)]	= "mw",
587 		[ilog2(VM_MAYEXEC)]	= "me",
588 		[ilog2(VM_MAYSHARE)]	= "ms",
589 		[ilog2(VM_GROWSDOWN)]	= "gd",
590 		[ilog2(VM_PFNMAP)]	= "pf",
591 		[ilog2(VM_DENYWRITE)]	= "dw",
592 #ifdef CONFIG_X86_INTEL_MPX
593 		[ilog2(VM_MPX)]		= "mp",
594 #endif
595 		[ilog2(VM_LOCKED)]	= "lo",
596 		[ilog2(VM_IO)]		= "io",
597 		[ilog2(VM_SEQ_READ)]	= "sr",
598 		[ilog2(VM_RAND_READ)]	= "rr",
599 		[ilog2(VM_DONTCOPY)]	= "dc",
600 		[ilog2(VM_DONTEXPAND)]	= "de",
601 		[ilog2(VM_ACCOUNT)]	= "ac",
602 		[ilog2(VM_NORESERVE)]	= "nr",
603 		[ilog2(VM_HUGETLB)]	= "ht",
604 		[ilog2(VM_ARCH_1)]	= "ar",
605 		[ilog2(VM_DONTDUMP)]	= "dd",
606 #ifdef CONFIG_MEM_SOFT_DIRTY
607 		[ilog2(VM_SOFTDIRTY)]	= "sd",
608 #endif
609 		[ilog2(VM_MIXEDMAP)]	= "mm",
610 		[ilog2(VM_HUGEPAGE)]	= "hg",
611 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
612 		[ilog2(VM_MERGEABLE)]	= "mg",
613 		[ilog2(VM_UFFD_MISSING)]= "um",
614 		[ilog2(VM_UFFD_WP)]	= "uw",
615 	};
616 	size_t i;
617 
618 	seq_puts(m, "VmFlags: ");
619 	for (i = 0; i < BITS_PER_LONG; i++) {
620 		if (vma->vm_flags & (1UL << i)) {
621 			seq_printf(m, "%c%c ",
622 				   mnemonics[i][0], mnemonics[i][1]);
623 		}
624 	}
625 	seq_putc(m, '\n');
626 }
627 
628 static int show_smap(struct seq_file *m, void *v, int is_pid)
629 {
630 	struct vm_area_struct *vma = v;
631 	struct mem_size_stats mss;
632 	struct mm_walk smaps_walk = {
633 		.pmd_entry = smaps_pte_range,
634 		.mm = vma->vm_mm,
635 		.private = &mss,
636 	};
637 
638 	memset(&mss, 0, sizeof mss);
639 	/* mmap_sem is held in m_start */
640 	walk_page_vma(vma, &smaps_walk);
641 
642 	show_map_vma(m, vma, is_pid);
643 
644 	seq_printf(m,
645 		   "Size:           %8lu kB\n"
646 		   "Rss:            %8lu kB\n"
647 		   "Pss:            %8lu kB\n"
648 		   "Shared_Clean:   %8lu kB\n"
649 		   "Shared_Dirty:   %8lu kB\n"
650 		   "Private_Clean:  %8lu kB\n"
651 		   "Private_Dirty:  %8lu kB\n"
652 		   "Referenced:     %8lu kB\n"
653 		   "Anonymous:      %8lu kB\n"
654 		   "AnonHugePages:  %8lu kB\n"
655 		   "Swap:           %8lu kB\n"
656 		   "SwapPss:        %8lu kB\n"
657 		   "KernelPageSize: %8lu kB\n"
658 		   "MMUPageSize:    %8lu kB\n"
659 		   "Locked:         %8lu kB\n",
660 		   (vma->vm_end - vma->vm_start) >> 10,
661 		   mss.resident >> 10,
662 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
663 		   mss.shared_clean  >> 10,
664 		   mss.shared_dirty  >> 10,
665 		   mss.private_clean >> 10,
666 		   mss.private_dirty >> 10,
667 		   mss.referenced >> 10,
668 		   mss.anonymous >> 10,
669 		   mss.anonymous_thp >> 10,
670 		   mss.swap >> 10,
671 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
672 		   vma_kernel_pagesize(vma) >> 10,
673 		   vma_mmu_pagesize(vma) >> 10,
674 		   (vma->vm_flags & VM_LOCKED) ?
675 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
676 
677 	show_smap_vma_flags(m, vma);
678 	m_cache_vma(m, vma);
679 	return 0;
680 }
681 
682 static int show_pid_smap(struct seq_file *m, void *v)
683 {
684 	return show_smap(m, v, 1);
685 }
686 
687 static int show_tid_smap(struct seq_file *m, void *v)
688 {
689 	return show_smap(m, v, 0);
690 }
691 
692 static const struct seq_operations proc_pid_smaps_op = {
693 	.start	= m_start,
694 	.next	= m_next,
695 	.stop	= m_stop,
696 	.show	= show_pid_smap
697 };
698 
699 static const struct seq_operations proc_tid_smaps_op = {
700 	.start	= m_start,
701 	.next	= m_next,
702 	.stop	= m_stop,
703 	.show	= show_tid_smap
704 };
705 
706 static int pid_smaps_open(struct inode *inode, struct file *file)
707 {
708 	return do_maps_open(inode, file, &proc_pid_smaps_op);
709 }
710 
711 static int tid_smaps_open(struct inode *inode, struct file *file)
712 {
713 	return do_maps_open(inode, file, &proc_tid_smaps_op);
714 }
715 
716 const struct file_operations proc_pid_smaps_operations = {
717 	.open		= pid_smaps_open,
718 	.read		= seq_read,
719 	.llseek		= seq_lseek,
720 	.release	= proc_map_release,
721 };
722 
723 const struct file_operations proc_tid_smaps_operations = {
724 	.open		= tid_smaps_open,
725 	.read		= seq_read,
726 	.llseek		= seq_lseek,
727 	.release	= proc_map_release,
728 };
729 
730 enum clear_refs_types {
731 	CLEAR_REFS_ALL = 1,
732 	CLEAR_REFS_ANON,
733 	CLEAR_REFS_MAPPED,
734 	CLEAR_REFS_SOFT_DIRTY,
735 	CLEAR_REFS_MM_HIWATER_RSS,
736 	CLEAR_REFS_LAST,
737 };
738 
739 struct clear_refs_private {
740 	enum clear_refs_types type;
741 };
742 
743 #ifdef CONFIG_MEM_SOFT_DIRTY
744 static inline void clear_soft_dirty(struct vm_area_struct *vma,
745 		unsigned long addr, pte_t *pte)
746 {
747 	/*
748 	 * The soft-dirty tracker uses #PF-s to catch writes
749 	 * to pages, so write-protect the pte as well. See the
750 	 * Documentation/vm/soft-dirty.txt for full description
751 	 * of how soft-dirty works.
752 	 */
753 	pte_t ptent = *pte;
754 
755 	if (pte_present(ptent)) {
756 		ptent = pte_wrprotect(ptent);
757 		ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY);
758 	} else if (is_swap_pte(ptent)) {
759 		ptent = pte_swp_clear_soft_dirty(ptent);
760 	}
761 
762 	set_pte_at(vma->vm_mm, addr, pte, ptent);
763 }
764 
765 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
766 		unsigned long addr, pmd_t *pmdp)
767 {
768 	pmd_t pmd = *pmdp;
769 
770 	pmd = pmd_wrprotect(pmd);
771 	pmd = pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);
772 
773 	if (vma->vm_flags & VM_SOFTDIRTY)
774 		vma->vm_flags &= ~VM_SOFTDIRTY;
775 
776 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
777 }
778 
779 #else
780 
781 static inline void clear_soft_dirty(struct vm_area_struct *vma,
782 		unsigned long addr, pte_t *pte)
783 {
784 }
785 
786 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
787 		unsigned long addr, pmd_t *pmdp)
788 {
789 }
790 #endif
791 
792 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
793 				unsigned long end, struct mm_walk *walk)
794 {
795 	struct clear_refs_private *cp = walk->private;
796 	struct vm_area_struct *vma = walk->vma;
797 	pte_t *pte, ptent;
798 	spinlock_t *ptl;
799 	struct page *page;
800 
801 	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
802 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
803 			clear_soft_dirty_pmd(vma, addr, pmd);
804 			goto out;
805 		}
806 
807 		page = pmd_page(*pmd);
808 
809 		/* Clear accessed and referenced bits. */
810 		pmdp_test_and_clear_young(vma, addr, pmd);
811 		test_and_clear_page_young(page);
812 		ClearPageReferenced(page);
813 out:
814 		spin_unlock(ptl);
815 		return 0;
816 	}
817 
818 	if (pmd_trans_unstable(pmd))
819 		return 0;
820 
821 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
822 	for (; addr != end; pte++, addr += PAGE_SIZE) {
823 		ptent = *pte;
824 
825 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
826 			clear_soft_dirty(vma, addr, pte);
827 			continue;
828 		}
829 
830 		if (!pte_present(ptent))
831 			continue;
832 
833 		page = vm_normal_page(vma, addr, ptent);
834 		if (!page)
835 			continue;
836 
837 		/* Clear accessed and referenced bits. */
838 		ptep_test_and_clear_young(vma, addr, pte);
839 		test_and_clear_page_young(page);
840 		ClearPageReferenced(page);
841 	}
842 	pte_unmap_unlock(pte - 1, ptl);
843 	cond_resched();
844 	return 0;
845 }
846 
847 static int clear_refs_test_walk(unsigned long start, unsigned long end,
848 				struct mm_walk *walk)
849 {
850 	struct clear_refs_private *cp = walk->private;
851 	struct vm_area_struct *vma = walk->vma;
852 
853 	if (vma->vm_flags & VM_PFNMAP)
854 		return 1;
855 
856 	/*
857 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
858 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
859 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
860 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
861 	 */
862 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
863 		return 1;
864 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
865 		return 1;
866 	return 0;
867 }
868 
869 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
870 				size_t count, loff_t *ppos)
871 {
872 	struct task_struct *task;
873 	char buffer[PROC_NUMBUF];
874 	struct mm_struct *mm;
875 	struct vm_area_struct *vma;
876 	enum clear_refs_types type;
877 	int itype;
878 	int rv;
879 
880 	memset(buffer, 0, sizeof(buffer));
881 	if (count > sizeof(buffer) - 1)
882 		count = sizeof(buffer) - 1;
883 	if (copy_from_user(buffer, buf, count))
884 		return -EFAULT;
885 	rv = kstrtoint(strstrip(buffer), 10, &itype);
886 	if (rv < 0)
887 		return rv;
888 	type = (enum clear_refs_types)itype;
889 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
890 		return -EINVAL;
891 
892 	task = get_proc_task(file_inode(file));
893 	if (!task)
894 		return -ESRCH;
895 	mm = get_task_mm(task);
896 	if (mm) {
897 		struct clear_refs_private cp = {
898 			.type = type,
899 		};
900 		struct mm_walk clear_refs_walk = {
901 			.pmd_entry = clear_refs_pte_range,
902 			.test_walk = clear_refs_test_walk,
903 			.mm = mm,
904 			.private = &cp,
905 		};
906 
907 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
908 			/*
909 			 * Writing 5 to /proc/pid/clear_refs resets the peak
910 			 * resident set size to this mm's current rss value.
911 			 */
912 			down_write(&mm->mmap_sem);
913 			reset_mm_hiwater_rss(mm);
914 			up_write(&mm->mmap_sem);
915 			goto out_mm;
916 		}
917 
918 		down_read(&mm->mmap_sem);
919 		if (type == CLEAR_REFS_SOFT_DIRTY) {
920 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
921 				if (!(vma->vm_flags & VM_SOFTDIRTY))
922 					continue;
923 				up_read(&mm->mmap_sem);
924 				down_write(&mm->mmap_sem);
925 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
926 					vma->vm_flags &= ~VM_SOFTDIRTY;
927 					vma_set_page_prot(vma);
928 				}
929 				downgrade_write(&mm->mmap_sem);
930 				break;
931 			}
932 			mmu_notifier_invalidate_range_start(mm, 0, -1);
933 		}
934 		walk_page_range(0, ~0UL, &clear_refs_walk);
935 		if (type == CLEAR_REFS_SOFT_DIRTY)
936 			mmu_notifier_invalidate_range_end(mm, 0, -1);
937 		flush_tlb_mm(mm);
938 		up_read(&mm->mmap_sem);
939 out_mm:
940 		mmput(mm);
941 	}
942 	put_task_struct(task);
943 
944 	return count;
945 }
946 
947 const struct file_operations proc_clear_refs_operations = {
948 	.write		= clear_refs_write,
949 	.llseek		= noop_llseek,
950 };
951 
952 typedef struct {
953 	u64 pme;
954 } pagemap_entry_t;
955 
956 struct pagemapread {
957 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
958 	pagemap_entry_t *buffer;
959 	bool show_pfn;
960 };
961 
962 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
963 #define PAGEMAP_WALK_MASK	(PMD_MASK)
964 
965 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
966 #define PM_PFRAME_BITS		55
967 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
968 #define PM_SOFT_DIRTY		BIT_ULL(55)
969 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
970 #define PM_FILE			BIT_ULL(61)
971 #define PM_SWAP			BIT_ULL(62)
972 #define PM_PRESENT		BIT_ULL(63)
973 
974 #define PM_END_OF_BUFFER    1
975 
976 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
977 {
978 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
979 }
980 
981 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
982 			  struct pagemapread *pm)
983 {
984 	pm->buffer[pm->pos++] = *pme;
985 	if (pm->pos >= pm->len)
986 		return PM_END_OF_BUFFER;
987 	return 0;
988 }
989 
990 static int pagemap_pte_hole(unsigned long start, unsigned long end,
991 				struct mm_walk *walk)
992 {
993 	struct pagemapread *pm = walk->private;
994 	unsigned long addr = start;
995 	int err = 0;
996 
997 	while (addr < end) {
998 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
999 		pagemap_entry_t pme = make_pme(0, 0);
1000 		/* End of address space hole, which we mark as non-present. */
1001 		unsigned long hole_end;
1002 
1003 		if (vma)
1004 			hole_end = min(end, vma->vm_start);
1005 		else
1006 			hole_end = end;
1007 
1008 		for (; addr < hole_end; addr += PAGE_SIZE) {
1009 			err = add_to_pagemap(addr, &pme, pm);
1010 			if (err)
1011 				goto out;
1012 		}
1013 
1014 		if (!vma)
1015 			break;
1016 
1017 		/* Addresses in the VMA. */
1018 		if (vma->vm_flags & VM_SOFTDIRTY)
1019 			pme = make_pme(0, PM_SOFT_DIRTY);
1020 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1021 			err = add_to_pagemap(addr, &pme, pm);
1022 			if (err)
1023 				goto out;
1024 		}
1025 	}
1026 out:
1027 	return err;
1028 }
1029 
1030 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1031 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1032 {
1033 	u64 frame = 0, flags = 0;
1034 	struct page *page = NULL;
1035 
1036 	if (pte_present(pte)) {
1037 		if (pm->show_pfn)
1038 			frame = pte_pfn(pte);
1039 		flags |= PM_PRESENT;
1040 		page = vm_normal_page(vma, addr, pte);
1041 		if (pte_soft_dirty(pte))
1042 			flags |= PM_SOFT_DIRTY;
1043 	} else if (is_swap_pte(pte)) {
1044 		swp_entry_t entry;
1045 		if (pte_swp_soft_dirty(pte))
1046 			flags |= PM_SOFT_DIRTY;
1047 		entry = pte_to_swp_entry(pte);
1048 		frame = swp_type(entry) |
1049 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1050 		flags |= PM_SWAP;
1051 		if (is_migration_entry(entry))
1052 			page = migration_entry_to_page(entry);
1053 	}
1054 
1055 	if (page && !PageAnon(page))
1056 		flags |= PM_FILE;
1057 	if (page && page_mapcount(page) == 1)
1058 		flags |= PM_MMAP_EXCLUSIVE;
1059 	if (vma->vm_flags & VM_SOFTDIRTY)
1060 		flags |= PM_SOFT_DIRTY;
1061 
1062 	return make_pme(frame, flags);
1063 }
1064 
1065 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1066 			     struct mm_walk *walk)
1067 {
1068 	struct vm_area_struct *vma = walk->vma;
1069 	struct pagemapread *pm = walk->private;
1070 	spinlock_t *ptl;
1071 	pte_t *pte, *orig_pte;
1072 	int err = 0;
1073 
1074 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1075 	if (pmd_trans_huge_lock(pmdp, vma, &ptl) == 1) {
1076 		u64 flags = 0, frame = 0;
1077 		pmd_t pmd = *pmdp;
1078 
1079 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1080 			flags |= PM_SOFT_DIRTY;
1081 
1082 		/*
1083 		 * Currently pmd for thp is always present because thp
1084 		 * can not be swapped-out, migrated, or HWPOISONed
1085 		 * (split in such cases instead.)
1086 		 * This if-check is just to prepare for future implementation.
1087 		 */
1088 		if (pmd_present(pmd)) {
1089 			struct page *page = pmd_page(pmd);
1090 
1091 			if (page_mapcount(page) == 1)
1092 				flags |= PM_MMAP_EXCLUSIVE;
1093 
1094 			flags |= PM_PRESENT;
1095 			if (pm->show_pfn)
1096 				frame = pmd_pfn(pmd) +
1097 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1098 		}
1099 
1100 		for (; addr != end; addr += PAGE_SIZE) {
1101 			pagemap_entry_t pme = make_pme(frame, flags);
1102 
1103 			err = add_to_pagemap(addr, &pme, pm);
1104 			if (err)
1105 				break;
1106 			if (pm->show_pfn && (flags & PM_PRESENT))
1107 				frame++;
1108 		}
1109 		spin_unlock(ptl);
1110 		return err;
1111 	}
1112 
1113 	if (pmd_trans_unstable(pmdp))
1114 		return 0;
1115 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1116 
1117 	/*
1118 	 * We can assume that @vma always points to a valid one and @end never
1119 	 * goes beyond vma->vm_end.
1120 	 */
1121 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1122 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1123 		pagemap_entry_t pme;
1124 
1125 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1126 		err = add_to_pagemap(addr, &pme, pm);
1127 		if (err)
1128 			break;
1129 	}
1130 	pte_unmap_unlock(orig_pte, ptl);
1131 
1132 	cond_resched();
1133 
1134 	return err;
1135 }
1136 
1137 #ifdef CONFIG_HUGETLB_PAGE
1138 /* This function walks within one hugetlb entry in the single call */
1139 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1140 				 unsigned long addr, unsigned long end,
1141 				 struct mm_walk *walk)
1142 {
1143 	struct pagemapread *pm = walk->private;
1144 	struct vm_area_struct *vma = walk->vma;
1145 	u64 flags = 0, frame = 0;
1146 	int err = 0;
1147 	pte_t pte;
1148 
1149 	if (vma->vm_flags & VM_SOFTDIRTY)
1150 		flags |= PM_SOFT_DIRTY;
1151 
1152 	pte = huge_ptep_get(ptep);
1153 	if (pte_present(pte)) {
1154 		struct page *page = pte_page(pte);
1155 
1156 		if (!PageAnon(page))
1157 			flags |= PM_FILE;
1158 
1159 		if (page_mapcount(page) == 1)
1160 			flags |= PM_MMAP_EXCLUSIVE;
1161 
1162 		flags |= PM_PRESENT;
1163 		if (pm->show_pfn)
1164 			frame = pte_pfn(pte) +
1165 				((addr & ~hmask) >> PAGE_SHIFT);
1166 	}
1167 
1168 	for (; addr != end; addr += PAGE_SIZE) {
1169 		pagemap_entry_t pme = make_pme(frame, flags);
1170 
1171 		err = add_to_pagemap(addr, &pme, pm);
1172 		if (err)
1173 			return err;
1174 		if (pm->show_pfn && (flags & PM_PRESENT))
1175 			frame++;
1176 	}
1177 
1178 	cond_resched();
1179 
1180 	return err;
1181 }
1182 #endif /* HUGETLB_PAGE */
1183 
1184 /*
1185  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1186  *
1187  * For each page in the address space, this file contains one 64-bit entry
1188  * consisting of the following:
1189  *
1190  * Bits 0-54  page frame number (PFN) if present
1191  * Bits 0-4   swap type if swapped
1192  * Bits 5-54  swap offset if swapped
1193  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1194  * Bit  56    page exclusively mapped
1195  * Bits 57-60 zero
1196  * Bit  61    page is file-page or shared-anon
1197  * Bit  62    page swapped
1198  * Bit  63    page present
1199  *
1200  * If the page is not present but in swap, then the PFN contains an
1201  * encoding of the swap file number and the page's offset into the
1202  * swap. Unmapped pages return a null PFN. This allows determining
1203  * precisely which pages are mapped (or in swap) and comparing mapped
1204  * pages between processes.
1205  *
1206  * Efficient users of this interface will use /proc/pid/maps to
1207  * determine which areas of memory are actually mapped and llseek to
1208  * skip over unmapped regions.
1209  */
1210 static ssize_t pagemap_read(struct file *file, char __user *buf,
1211 			    size_t count, loff_t *ppos)
1212 {
1213 	struct mm_struct *mm = file->private_data;
1214 	struct pagemapread pm;
1215 	struct mm_walk pagemap_walk = {};
1216 	unsigned long src;
1217 	unsigned long svpfn;
1218 	unsigned long start_vaddr;
1219 	unsigned long end_vaddr;
1220 	int ret = 0, copied = 0;
1221 
1222 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
1223 		goto out;
1224 
1225 	ret = -EINVAL;
1226 	/* file position must be aligned */
1227 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1228 		goto out_mm;
1229 
1230 	ret = 0;
1231 	if (!count)
1232 		goto out_mm;
1233 
1234 	/* do not disclose physical addresses: attack vector */
1235 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1236 
1237 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1238 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1239 	ret = -ENOMEM;
1240 	if (!pm.buffer)
1241 		goto out_mm;
1242 
1243 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1244 	pagemap_walk.pte_hole = pagemap_pte_hole;
1245 #ifdef CONFIG_HUGETLB_PAGE
1246 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1247 #endif
1248 	pagemap_walk.mm = mm;
1249 	pagemap_walk.private = &pm;
1250 
1251 	src = *ppos;
1252 	svpfn = src / PM_ENTRY_BYTES;
1253 	start_vaddr = svpfn << PAGE_SHIFT;
1254 	end_vaddr = mm->task_size;
1255 
1256 	/* watch out for wraparound */
1257 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1258 		start_vaddr = end_vaddr;
1259 
1260 	/*
1261 	 * The odds are that this will stop walking way
1262 	 * before end_vaddr, because the length of the
1263 	 * user buffer is tracked in "pm", and the walk
1264 	 * will stop when we hit the end of the buffer.
1265 	 */
1266 	ret = 0;
1267 	while (count && (start_vaddr < end_vaddr)) {
1268 		int len;
1269 		unsigned long end;
1270 
1271 		pm.pos = 0;
1272 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1273 		/* overflow ? */
1274 		if (end < start_vaddr || end > end_vaddr)
1275 			end = end_vaddr;
1276 		down_read(&mm->mmap_sem);
1277 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1278 		up_read(&mm->mmap_sem);
1279 		start_vaddr = end;
1280 
1281 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1282 		if (copy_to_user(buf, pm.buffer, len)) {
1283 			ret = -EFAULT;
1284 			goto out_free;
1285 		}
1286 		copied += len;
1287 		buf += len;
1288 		count -= len;
1289 	}
1290 	*ppos += copied;
1291 	if (!ret || ret == PM_END_OF_BUFFER)
1292 		ret = copied;
1293 
1294 out_free:
1295 	kfree(pm.buffer);
1296 out_mm:
1297 	mmput(mm);
1298 out:
1299 	return ret;
1300 }
1301 
1302 static int pagemap_open(struct inode *inode, struct file *file)
1303 {
1304 	struct mm_struct *mm;
1305 
1306 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1307 	if (IS_ERR(mm))
1308 		return PTR_ERR(mm);
1309 	file->private_data = mm;
1310 	return 0;
1311 }
1312 
1313 static int pagemap_release(struct inode *inode, struct file *file)
1314 {
1315 	struct mm_struct *mm = file->private_data;
1316 
1317 	if (mm)
1318 		mmdrop(mm);
1319 	return 0;
1320 }
1321 
1322 const struct file_operations proc_pagemap_operations = {
1323 	.llseek		= mem_lseek, /* borrow this */
1324 	.read		= pagemap_read,
1325 	.open		= pagemap_open,
1326 	.release	= pagemap_release,
1327 };
1328 #endif /* CONFIG_PROC_PAGE_MONITOR */
1329 
1330 #ifdef CONFIG_NUMA
1331 
1332 struct numa_maps {
1333 	unsigned long pages;
1334 	unsigned long anon;
1335 	unsigned long active;
1336 	unsigned long writeback;
1337 	unsigned long mapcount_max;
1338 	unsigned long dirty;
1339 	unsigned long swapcache;
1340 	unsigned long node[MAX_NUMNODES];
1341 };
1342 
1343 struct numa_maps_private {
1344 	struct proc_maps_private proc_maps;
1345 	struct numa_maps md;
1346 };
1347 
1348 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1349 			unsigned long nr_pages)
1350 {
1351 	int count = page_mapcount(page);
1352 
1353 	md->pages += nr_pages;
1354 	if (pte_dirty || PageDirty(page))
1355 		md->dirty += nr_pages;
1356 
1357 	if (PageSwapCache(page))
1358 		md->swapcache += nr_pages;
1359 
1360 	if (PageActive(page) || PageUnevictable(page))
1361 		md->active += nr_pages;
1362 
1363 	if (PageWriteback(page))
1364 		md->writeback += nr_pages;
1365 
1366 	if (PageAnon(page))
1367 		md->anon += nr_pages;
1368 
1369 	if (count > md->mapcount_max)
1370 		md->mapcount_max = count;
1371 
1372 	md->node[page_to_nid(page)] += nr_pages;
1373 }
1374 
1375 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1376 		unsigned long addr)
1377 {
1378 	struct page *page;
1379 	int nid;
1380 
1381 	if (!pte_present(pte))
1382 		return NULL;
1383 
1384 	page = vm_normal_page(vma, addr, pte);
1385 	if (!page)
1386 		return NULL;
1387 
1388 	if (PageReserved(page))
1389 		return NULL;
1390 
1391 	nid = page_to_nid(page);
1392 	if (!node_isset(nid, node_states[N_MEMORY]))
1393 		return NULL;
1394 
1395 	return page;
1396 }
1397 
1398 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1399 		unsigned long end, struct mm_walk *walk)
1400 {
1401 	struct numa_maps *md = walk->private;
1402 	struct vm_area_struct *vma = walk->vma;
1403 	spinlock_t *ptl;
1404 	pte_t *orig_pte;
1405 	pte_t *pte;
1406 
1407 	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
1408 		pte_t huge_pte = *(pte_t *)pmd;
1409 		struct page *page;
1410 
1411 		page = can_gather_numa_stats(huge_pte, vma, addr);
1412 		if (page)
1413 			gather_stats(page, md, pte_dirty(huge_pte),
1414 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1415 		spin_unlock(ptl);
1416 		return 0;
1417 	}
1418 
1419 	if (pmd_trans_unstable(pmd))
1420 		return 0;
1421 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1422 	do {
1423 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1424 		if (!page)
1425 			continue;
1426 		gather_stats(page, md, pte_dirty(*pte), 1);
1427 
1428 	} while (pte++, addr += PAGE_SIZE, addr != end);
1429 	pte_unmap_unlock(orig_pte, ptl);
1430 	return 0;
1431 }
1432 #ifdef CONFIG_HUGETLB_PAGE
1433 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1434 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1435 {
1436 	struct numa_maps *md;
1437 	struct page *page;
1438 
1439 	if (!pte_present(*pte))
1440 		return 0;
1441 
1442 	page = pte_page(*pte);
1443 	if (!page)
1444 		return 0;
1445 
1446 	md = walk->private;
1447 	gather_stats(page, md, pte_dirty(*pte), 1);
1448 	return 0;
1449 }
1450 
1451 #else
1452 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1453 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1454 {
1455 	return 0;
1456 }
1457 #endif
1458 
1459 /*
1460  * Display pages allocated per node and memory policy via /proc.
1461  */
1462 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1463 {
1464 	struct numa_maps_private *numa_priv = m->private;
1465 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1466 	struct vm_area_struct *vma = v;
1467 	struct numa_maps *md = &numa_priv->md;
1468 	struct file *file = vma->vm_file;
1469 	struct mm_struct *mm = vma->vm_mm;
1470 	struct mm_walk walk = {
1471 		.hugetlb_entry = gather_hugetlb_stats,
1472 		.pmd_entry = gather_pte_stats,
1473 		.private = md,
1474 		.mm = mm,
1475 	};
1476 	struct mempolicy *pol;
1477 	char buffer[64];
1478 	int nid;
1479 
1480 	if (!mm)
1481 		return 0;
1482 
1483 	/* Ensure we start with an empty set of numa_maps statistics. */
1484 	memset(md, 0, sizeof(*md));
1485 
1486 	pol = __get_vma_policy(vma, vma->vm_start);
1487 	if (pol) {
1488 		mpol_to_str(buffer, sizeof(buffer), pol);
1489 		mpol_cond_put(pol);
1490 	} else {
1491 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1492 	}
1493 
1494 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1495 
1496 	if (file) {
1497 		seq_puts(m, " file=");
1498 		seq_file_path(m, file, "\n\t= ");
1499 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1500 		seq_puts(m, " heap");
1501 	} else {
1502 		pid_t tid = pid_of_stack(proc_priv, vma, is_pid);
1503 		if (tid != 0) {
1504 			/*
1505 			 * Thread stack in /proc/PID/task/TID/maps or
1506 			 * the main process stack.
1507 			 */
1508 			if (!is_pid || (vma->vm_start <= mm->start_stack &&
1509 			    vma->vm_end >= mm->start_stack))
1510 				seq_puts(m, " stack");
1511 			else
1512 				seq_printf(m, " stack:%d", tid);
1513 		}
1514 	}
1515 
1516 	if (is_vm_hugetlb_page(vma))
1517 		seq_puts(m, " huge");
1518 
1519 	/* mmap_sem is held by m_start */
1520 	walk_page_vma(vma, &walk);
1521 
1522 	if (!md->pages)
1523 		goto out;
1524 
1525 	if (md->anon)
1526 		seq_printf(m, " anon=%lu", md->anon);
1527 
1528 	if (md->dirty)
1529 		seq_printf(m, " dirty=%lu", md->dirty);
1530 
1531 	if (md->pages != md->anon && md->pages != md->dirty)
1532 		seq_printf(m, " mapped=%lu", md->pages);
1533 
1534 	if (md->mapcount_max > 1)
1535 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1536 
1537 	if (md->swapcache)
1538 		seq_printf(m, " swapcache=%lu", md->swapcache);
1539 
1540 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1541 		seq_printf(m, " active=%lu", md->active);
1542 
1543 	if (md->writeback)
1544 		seq_printf(m, " writeback=%lu", md->writeback);
1545 
1546 	for_each_node_state(nid, N_MEMORY)
1547 		if (md->node[nid])
1548 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1549 
1550 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1551 out:
1552 	seq_putc(m, '\n');
1553 	m_cache_vma(m, vma);
1554 	return 0;
1555 }
1556 
1557 static int show_pid_numa_map(struct seq_file *m, void *v)
1558 {
1559 	return show_numa_map(m, v, 1);
1560 }
1561 
1562 static int show_tid_numa_map(struct seq_file *m, void *v)
1563 {
1564 	return show_numa_map(m, v, 0);
1565 }
1566 
1567 static const struct seq_operations proc_pid_numa_maps_op = {
1568 	.start  = m_start,
1569 	.next   = m_next,
1570 	.stop   = m_stop,
1571 	.show   = show_pid_numa_map,
1572 };
1573 
1574 static const struct seq_operations proc_tid_numa_maps_op = {
1575 	.start  = m_start,
1576 	.next   = m_next,
1577 	.stop   = m_stop,
1578 	.show   = show_tid_numa_map,
1579 };
1580 
1581 static int numa_maps_open(struct inode *inode, struct file *file,
1582 			  const struct seq_operations *ops)
1583 {
1584 	return proc_maps_open(inode, file, ops,
1585 				sizeof(struct numa_maps_private));
1586 }
1587 
1588 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1589 {
1590 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1591 }
1592 
1593 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1594 {
1595 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1596 }
1597 
1598 const struct file_operations proc_pid_numa_maps_operations = {
1599 	.open		= pid_numa_maps_open,
1600 	.read		= seq_read,
1601 	.llseek		= seq_lseek,
1602 	.release	= proc_map_release,
1603 };
1604 
1605 const struct file_operations proc_tid_numa_maps_operations = {
1606 	.open		= tid_numa_maps_open,
1607 	.read		= seq_read,
1608 	.llseek		= seq_lseek,
1609 	.release	= proc_map_release,
1610 };
1611 #endif /* CONFIG_NUMA */
1612