xref: /linux/fs/proc/task_mmu.c (revision c411ed854584a71b0e86ac3019b60e4789d88086)
1 #include <linux/mm.h>
2 #include <linux/vmacache.h>
3 #include <linux/hugetlb.h>
4 #include <linux/huge_mm.h>
5 #include <linux/mount.h>
6 #include <linux/seq_file.h>
7 #include <linux/highmem.h>
8 #include <linux/ptrace.h>
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
11 #include <linux/mempolicy.h>
12 #include <linux/rmap.h>
13 #include <linux/swap.h>
14 #include <linux/sched/mm.h>
15 #include <linux/swapops.h>
16 #include <linux/mmu_notifier.h>
17 #include <linux/page_idle.h>
18 #include <linux/shmem_fs.h>
19 #include <linux/uaccess.h>
20 
21 #include <asm/elf.h>
22 #include <asm/tlb.h>
23 #include <asm/tlbflush.h>
24 #include "internal.h"
25 
26 void task_mem(struct seq_file *m, struct mm_struct *mm)
27 {
28 	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
29 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
30 
31 	anon = get_mm_counter(mm, MM_ANONPAGES);
32 	file = get_mm_counter(mm, MM_FILEPAGES);
33 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
34 
35 	/*
36 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
37 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
38 	 * collector of these hiwater stats must therefore get total_vm
39 	 * and rss too, which will usually be the higher.  Barriers? not
40 	 * worth the effort, such snapshots can always be inconsistent.
41 	 */
42 	hiwater_vm = total_vm = mm->total_vm;
43 	if (hiwater_vm < mm->hiwater_vm)
44 		hiwater_vm = mm->hiwater_vm;
45 	hiwater_rss = total_rss = anon + file + shmem;
46 	if (hiwater_rss < mm->hiwater_rss)
47 		hiwater_rss = mm->hiwater_rss;
48 
49 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
50 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
51 	swap = get_mm_counter(mm, MM_SWAPENTS);
52 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
53 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
54 	seq_printf(m,
55 		"VmPeak:\t%8lu kB\n"
56 		"VmSize:\t%8lu kB\n"
57 		"VmLck:\t%8lu kB\n"
58 		"VmPin:\t%8lu kB\n"
59 		"VmHWM:\t%8lu kB\n"
60 		"VmRSS:\t%8lu kB\n"
61 		"RssAnon:\t%8lu kB\n"
62 		"RssFile:\t%8lu kB\n"
63 		"RssShmem:\t%8lu kB\n"
64 		"VmData:\t%8lu kB\n"
65 		"VmStk:\t%8lu kB\n"
66 		"VmExe:\t%8lu kB\n"
67 		"VmLib:\t%8lu kB\n"
68 		"VmPTE:\t%8lu kB\n"
69 		"VmPMD:\t%8lu kB\n"
70 		"VmSwap:\t%8lu kB\n",
71 		hiwater_vm << (PAGE_SHIFT-10),
72 		total_vm << (PAGE_SHIFT-10),
73 		mm->locked_vm << (PAGE_SHIFT-10),
74 		mm->pinned_vm << (PAGE_SHIFT-10),
75 		hiwater_rss << (PAGE_SHIFT-10),
76 		total_rss << (PAGE_SHIFT-10),
77 		anon << (PAGE_SHIFT-10),
78 		file << (PAGE_SHIFT-10),
79 		shmem << (PAGE_SHIFT-10),
80 		mm->data_vm << (PAGE_SHIFT-10),
81 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
82 		ptes >> 10,
83 		pmds >> 10,
84 		swap << (PAGE_SHIFT-10));
85 	hugetlb_report_usage(m, mm);
86 }
87 
88 unsigned long task_vsize(struct mm_struct *mm)
89 {
90 	return PAGE_SIZE * mm->total_vm;
91 }
92 
93 unsigned long task_statm(struct mm_struct *mm,
94 			 unsigned long *shared, unsigned long *text,
95 			 unsigned long *data, unsigned long *resident)
96 {
97 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
98 			get_mm_counter(mm, MM_SHMEMPAGES);
99 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
100 								>> PAGE_SHIFT;
101 	*data = mm->data_vm + mm->stack_vm;
102 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
103 	return mm->total_vm;
104 }
105 
106 #ifdef CONFIG_NUMA
107 /*
108  * Save get_task_policy() for show_numa_map().
109  */
110 static void hold_task_mempolicy(struct proc_maps_private *priv)
111 {
112 	struct task_struct *task = priv->task;
113 
114 	task_lock(task);
115 	priv->task_mempolicy = get_task_policy(task);
116 	mpol_get(priv->task_mempolicy);
117 	task_unlock(task);
118 }
119 static void release_task_mempolicy(struct proc_maps_private *priv)
120 {
121 	mpol_put(priv->task_mempolicy);
122 }
123 #else
124 static void hold_task_mempolicy(struct proc_maps_private *priv)
125 {
126 }
127 static void release_task_mempolicy(struct proc_maps_private *priv)
128 {
129 }
130 #endif
131 
132 static void vma_stop(struct proc_maps_private *priv)
133 {
134 	struct mm_struct *mm = priv->mm;
135 
136 	release_task_mempolicy(priv);
137 	up_read(&mm->mmap_sem);
138 	mmput(mm);
139 }
140 
141 static struct vm_area_struct *
142 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
143 {
144 	if (vma == priv->tail_vma)
145 		return NULL;
146 	return vma->vm_next ?: priv->tail_vma;
147 }
148 
149 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
150 {
151 	if (m->count < m->size)	/* vma is copied successfully */
152 		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
153 }
154 
155 static void *m_start(struct seq_file *m, loff_t *ppos)
156 {
157 	struct proc_maps_private *priv = m->private;
158 	unsigned long last_addr = m->version;
159 	struct mm_struct *mm;
160 	struct vm_area_struct *vma;
161 	unsigned int pos = *ppos;
162 
163 	/* See m_cache_vma(). Zero at the start or after lseek. */
164 	if (last_addr == -1UL)
165 		return NULL;
166 
167 	priv->task = get_proc_task(priv->inode);
168 	if (!priv->task)
169 		return ERR_PTR(-ESRCH);
170 
171 	mm = priv->mm;
172 	if (!mm || !mmget_not_zero(mm))
173 		return NULL;
174 
175 	down_read(&mm->mmap_sem);
176 	hold_task_mempolicy(priv);
177 	priv->tail_vma = get_gate_vma(mm);
178 
179 	if (last_addr) {
180 		vma = find_vma(mm, last_addr - 1);
181 		if (vma && vma->vm_start <= last_addr)
182 			vma = m_next_vma(priv, vma);
183 		if (vma)
184 			return vma;
185 	}
186 
187 	m->version = 0;
188 	if (pos < mm->map_count) {
189 		for (vma = mm->mmap; pos; pos--) {
190 			m->version = vma->vm_start;
191 			vma = vma->vm_next;
192 		}
193 		return vma;
194 	}
195 
196 	/* we do not bother to update m->version in this case */
197 	if (pos == mm->map_count && priv->tail_vma)
198 		return priv->tail_vma;
199 
200 	vma_stop(priv);
201 	return NULL;
202 }
203 
204 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
205 {
206 	struct proc_maps_private *priv = m->private;
207 	struct vm_area_struct *next;
208 
209 	(*pos)++;
210 	next = m_next_vma(priv, v);
211 	if (!next)
212 		vma_stop(priv);
213 	return next;
214 }
215 
216 static void m_stop(struct seq_file *m, void *v)
217 {
218 	struct proc_maps_private *priv = m->private;
219 
220 	if (!IS_ERR_OR_NULL(v))
221 		vma_stop(priv);
222 	if (priv->task) {
223 		put_task_struct(priv->task);
224 		priv->task = NULL;
225 	}
226 }
227 
228 static int proc_maps_open(struct inode *inode, struct file *file,
229 			const struct seq_operations *ops, int psize)
230 {
231 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
232 
233 	if (!priv)
234 		return -ENOMEM;
235 
236 	priv->inode = inode;
237 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
238 	if (IS_ERR(priv->mm)) {
239 		int err = PTR_ERR(priv->mm);
240 
241 		seq_release_private(inode, file);
242 		return err;
243 	}
244 
245 	return 0;
246 }
247 
248 static int proc_map_release(struct inode *inode, struct file *file)
249 {
250 	struct seq_file *seq = file->private_data;
251 	struct proc_maps_private *priv = seq->private;
252 
253 	if (priv->mm)
254 		mmdrop(priv->mm);
255 
256 	return seq_release_private(inode, file);
257 }
258 
259 static int do_maps_open(struct inode *inode, struct file *file,
260 			const struct seq_operations *ops)
261 {
262 	return proc_maps_open(inode, file, ops,
263 				sizeof(struct proc_maps_private));
264 }
265 
266 /*
267  * Indicate if the VMA is a stack for the given task; for
268  * /proc/PID/maps that is the stack of the main task.
269  */
270 static int is_stack(struct proc_maps_private *priv,
271 		    struct vm_area_struct *vma)
272 {
273 	/*
274 	 * We make no effort to guess what a given thread considers to be
275 	 * its "stack".  It's not even well-defined for programs written
276 	 * languages like Go.
277 	 */
278 	return vma->vm_start <= vma->vm_mm->start_stack &&
279 		vma->vm_end >= vma->vm_mm->start_stack;
280 }
281 
282 static void
283 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
284 {
285 	struct mm_struct *mm = vma->vm_mm;
286 	struct file *file = vma->vm_file;
287 	struct proc_maps_private *priv = m->private;
288 	vm_flags_t flags = vma->vm_flags;
289 	unsigned long ino = 0;
290 	unsigned long long pgoff = 0;
291 	unsigned long start, end;
292 	dev_t dev = 0;
293 	const char *name = NULL;
294 
295 	if (file) {
296 		struct inode *inode = file_inode(vma->vm_file);
297 		dev = inode->i_sb->s_dev;
298 		ino = inode->i_ino;
299 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
300 	}
301 
302 	start = vma->vm_start;
303 	end = vma->vm_end;
304 
305 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
306 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
307 			start,
308 			end,
309 			flags & VM_READ ? 'r' : '-',
310 			flags & VM_WRITE ? 'w' : '-',
311 			flags & VM_EXEC ? 'x' : '-',
312 			flags & VM_MAYSHARE ? 's' : 'p',
313 			pgoff,
314 			MAJOR(dev), MINOR(dev), ino);
315 
316 	/*
317 	 * Print the dentry name for named mappings, and a
318 	 * special [heap] marker for the heap:
319 	 */
320 	if (file) {
321 		seq_pad(m, ' ');
322 		seq_file_path(m, file, "\n");
323 		goto done;
324 	}
325 
326 	if (vma->vm_ops && vma->vm_ops->name) {
327 		name = vma->vm_ops->name(vma);
328 		if (name)
329 			goto done;
330 	}
331 
332 	name = arch_vma_name(vma);
333 	if (!name) {
334 		if (!mm) {
335 			name = "[vdso]";
336 			goto done;
337 		}
338 
339 		if (vma->vm_start <= mm->brk &&
340 		    vma->vm_end >= mm->start_brk) {
341 			name = "[heap]";
342 			goto done;
343 		}
344 
345 		if (is_stack(priv, vma))
346 			name = "[stack]";
347 	}
348 
349 done:
350 	if (name) {
351 		seq_pad(m, ' ');
352 		seq_puts(m, name);
353 	}
354 	seq_putc(m, '\n');
355 }
356 
357 static int show_map(struct seq_file *m, void *v, int is_pid)
358 {
359 	show_map_vma(m, v, is_pid);
360 	m_cache_vma(m, v);
361 	return 0;
362 }
363 
364 static int show_pid_map(struct seq_file *m, void *v)
365 {
366 	return show_map(m, v, 1);
367 }
368 
369 static int show_tid_map(struct seq_file *m, void *v)
370 {
371 	return show_map(m, v, 0);
372 }
373 
374 static const struct seq_operations proc_pid_maps_op = {
375 	.start	= m_start,
376 	.next	= m_next,
377 	.stop	= m_stop,
378 	.show	= show_pid_map
379 };
380 
381 static const struct seq_operations proc_tid_maps_op = {
382 	.start	= m_start,
383 	.next	= m_next,
384 	.stop	= m_stop,
385 	.show	= show_tid_map
386 };
387 
388 static int pid_maps_open(struct inode *inode, struct file *file)
389 {
390 	return do_maps_open(inode, file, &proc_pid_maps_op);
391 }
392 
393 static int tid_maps_open(struct inode *inode, struct file *file)
394 {
395 	return do_maps_open(inode, file, &proc_tid_maps_op);
396 }
397 
398 const struct file_operations proc_pid_maps_operations = {
399 	.open		= pid_maps_open,
400 	.read		= seq_read,
401 	.llseek		= seq_lseek,
402 	.release	= proc_map_release,
403 };
404 
405 const struct file_operations proc_tid_maps_operations = {
406 	.open		= tid_maps_open,
407 	.read		= seq_read,
408 	.llseek		= seq_lseek,
409 	.release	= proc_map_release,
410 };
411 
412 /*
413  * Proportional Set Size(PSS): my share of RSS.
414  *
415  * PSS of a process is the count of pages it has in memory, where each
416  * page is divided by the number of processes sharing it.  So if a
417  * process has 1000 pages all to itself, and 1000 shared with one other
418  * process, its PSS will be 1500.
419  *
420  * To keep (accumulated) division errors low, we adopt a 64bit
421  * fixed-point pss counter to minimize division errors. So (pss >>
422  * PSS_SHIFT) would be the real byte count.
423  *
424  * A shift of 12 before division means (assuming 4K page size):
425  * 	- 1M 3-user-pages add up to 8KB errors;
426  * 	- supports mapcount up to 2^24, or 16M;
427  * 	- supports PSS up to 2^52 bytes, or 4PB.
428  */
429 #define PSS_SHIFT 12
430 
431 #ifdef CONFIG_PROC_PAGE_MONITOR
432 struct mem_size_stats {
433 	unsigned long resident;
434 	unsigned long shared_clean;
435 	unsigned long shared_dirty;
436 	unsigned long private_clean;
437 	unsigned long private_dirty;
438 	unsigned long referenced;
439 	unsigned long anonymous;
440 	unsigned long lazyfree;
441 	unsigned long anonymous_thp;
442 	unsigned long shmem_thp;
443 	unsigned long swap;
444 	unsigned long shared_hugetlb;
445 	unsigned long private_hugetlb;
446 	u64 pss;
447 	u64 swap_pss;
448 	bool check_shmem_swap;
449 };
450 
451 static void smaps_account(struct mem_size_stats *mss, struct page *page,
452 		bool compound, bool young, bool dirty)
453 {
454 	int i, nr = compound ? 1 << compound_order(page) : 1;
455 	unsigned long size = nr * PAGE_SIZE;
456 
457 	if (PageAnon(page)) {
458 		mss->anonymous += size;
459 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
460 			mss->lazyfree += size;
461 	}
462 
463 	mss->resident += size;
464 	/* Accumulate the size in pages that have been accessed. */
465 	if (young || page_is_young(page) || PageReferenced(page))
466 		mss->referenced += size;
467 
468 	/*
469 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
470 	 * If any subpage of the compound page mapped with PTE it would elevate
471 	 * page_count().
472 	 */
473 	if (page_count(page) == 1) {
474 		if (dirty || PageDirty(page))
475 			mss->private_dirty += size;
476 		else
477 			mss->private_clean += size;
478 		mss->pss += (u64)size << PSS_SHIFT;
479 		return;
480 	}
481 
482 	for (i = 0; i < nr; i++, page++) {
483 		int mapcount = page_mapcount(page);
484 
485 		if (mapcount >= 2) {
486 			if (dirty || PageDirty(page))
487 				mss->shared_dirty += PAGE_SIZE;
488 			else
489 				mss->shared_clean += PAGE_SIZE;
490 			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
491 		} else {
492 			if (dirty || PageDirty(page))
493 				mss->private_dirty += PAGE_SIZE;
494 			else
495 				mss->private_clean += PAGE_SIZE;
496 			mss->pss += PAGE_SIZE << PSS_SHIFT;
497 		}
498 	}
499 }
500 
501 #ifdef CONFIG_SHMEM
502 static int smaps_pte_hole(unsigned long addr, unsigned long end,
503 		struct mm_walk *walk)
504 {
505 	struct mem_size_stats *mss = walk->private;
506 
507 	mss->swap += shmem_partial_swap_usage(
508 			walk->vma->vm_file->f_mapping, addr, end);
509 
510 	return 0;
511 }
512 #endif
513 
514 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
515 		struct mm_walk *walk)
516 {
517 	struct mem_size_stats *mss = walk->private;
518 	struct vm_area_struct *vma = walk->vma;
519 	struct page *page = NULL;
520 
521 	if (pte_present(*pte)) {
522 		page = vm_normal_page(vma, addr, *pte);
523 	} else if (is_swap_pte(*pte)) {
524 		swp_entry_t swpent = pte_to_swp_entry(*pte);
525 
526 		if (!non_swap_entry(swpent)) {
527 			int mapcount;
528 
529 			mss->swap += PAGE_SIZE;
530 			mapcount = swp_swapcount(swpent);
531 			if (mapcount >= 2) {
532 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
533 
534 				do_div(pss_delta, mapcount);
535 				mss->swap_pss += pss_delta;
536 			} else {
537 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
538 			}
539 		} else if (is_migration_entry(swpent))
540 			page = migration_entry_to_page(swpent);
541 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
542 							&& pte_none(*pte))) {
543 		page = find_get_entry(vma->vm_file->f_mapping,
544 						linear_page_index(vma, addr));
545 		if (!page)
546 			return;
547 
548 		if (radix_tree_exceptional_entry(page))
549 			mss->swap += PAGE_SIZE;
550 		else
551 			put_page(page);
552 
553 		return;
554 	}
555 
556 	if (!page)
557 		return;
558 
559 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
560 }
561 
562 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
563 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
564 		struct mm_walk *walk)
565 {
566 	struct mem_size_stats *mss = walk->private;
567 	struct vm_area_struct *vma = walk->vma;
568 	struct page *page;
569 
570 	/* FOLL_DUMP will return -EFAULT on huge zero page */
571 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
572 	if (IS_ERR_OR_NULL(page))
573 		return;
574 	if (PageAnon(page))
575 		mss->anonymous_thp += HPAGE_PMD_SIZE;
576 	else if (PageSwapBacked(page))
577 		mss->shmem_thp += HPAGE_PMD_SIZE;
578 	else if (is_zone_device_page(page))
579 		/* pass */;
580 	else
581 		VM_BUG_ON_PAGE(1, page);
582 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
583 }
584 #else
585 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
586 		struct mm_walk *walk)
587 {
588 }
589 #endif
590 
591 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
592 			   struct mm_walk *walk)
593 {
594 	struct vm_area_struct *vma = walk->vma;
595 	pte_t *pte;
596 	spinlock_t *ptl;
597 
598 	ptl = pmd_trans_huge_lock(pmd, vma);
599 	if (ptl) {
600 		smaps_pmd_entry(pmd, addr, walk);
601 		spin_unlock(ptl);
602 		return 0;
603 	}
604 
605 	if (pmd_trans_unstable(pmd))
606 		return 0;
607 	/*
608 	 * The mmap_sem held all the way back in m_start() is what
609 	 * keeps khugepaged out of here and from collapsing things
610 	 * in here.
611 	 */
612 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
613 	for (; addr != end; pte++, addr += PAGE_SIZE)
614 		smaps_pte_entry(pte, addr, walk);
615 	pte_unmap_unlock(pte - 1, ptl);
616 	cond_resched();
617 	return 0;
618 }
619 
620 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
621 {
622 	/*
623 	 * Don't forget to update Documentation/ on changes.
624 	 */
625 	static const char mnemonics[BITS_PER_LONG][2] = {
626 		/*
627 		 * In case if we meet a flag we don't know about.
628 		 */
629 		[0 ... (BITS_PER_LONG-1)] = "??",
630 
631 		[ilog2(VM_READ)]	= "rd",
632 		[ilog2(VM_WRITE)]	= "wr",
633 		[ilog2(VM_EXEC)]	= "ex",
634 		[ilog2(VM_SHARED)]	= "sh",
635 		[ilog2(VM_MAYREAD)]	= "mr",
636 		[ilog2(VM_MAYWRITE)]	= "mw",
637 		[ilog2(VM_MAYEXEC)]	= "me",
638 		[ilog2(VM_MAYSHARE)]	= "ms",
639 		[ilog2(VM_GROWSDOWN)]	= "gd",
640 		[ilog2(VM_PFNMAP)]	= "pf",
641 		[ilog2(VM_DENYWRITE)]	= "dw",
642 #ifdef CONFIG_X86_INTEL_MPX
643 		[ilog2(VM_MPX)]		= "mp",
644 #endif
645 		[ilog2(VM_LOCKED)]	= "lo",
646 		[ilog2(VM_IO)]		= "io",
647 		[ilog2(VM_SEQ_READ)]	= "sr",
648 		[ilog2(VM_RAND_READ)]	= "rr",
649 		[ilog2(VM_DONTCOPY)]	= "dc",
650 		[ilog2(VM_DONTEXPAND)]	= "de",
651 		[ilog2(VM_ACCOUNT)]	= "ac",
652 		[ilog2(VM_NORESERVE)]	= "nr",
653 		[ilog2(VM_HUGETLB)]	= "ht",
654 		[ilog2(VM_ARCH_1)]	= "ar",
655 		[ilog2(VM_DONTDUMP)]	= "dd",
656 #ifdef CONFIG_MEM_SOFT_DIRTY
657 		[ilog2(VM_SOFTDIRTY)]	= "sd",
658 #endif
659 		[ilog2(VM_MIXEDMAP)]	= "mm",
660 		[ilog2(VM_HUGEPAGE)]	= "hg",
661 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
662 		[ilog2(VM_MERGEABLE)]	= "mg",
663 		[ilog2(VM_UFFD_MISSING)]= "um",
664 		[ilog2(VM_UFFD_WP)]	= "uw",
665 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
666 		/* These come out via ProtectionKey: */
667 		[ilog2(VM_PKEY_BIT0)]	= "",
668 		[ilog2(VM_PKEY_BIT1)]	= "",
669 		[ilog2(VM_PKEY_BIT2)]	= "",
670 		[ilog2(VM_PKEY_BIT3)]	= "",
671 #endif
672 	};
673 	size_t i;
674 
675 	seq_puts(m, "VmFlags: ");
676 	for (i = 0; i < BITS_PER_LONG; i++) {
677 		if (!mnemonics[i][0])
678 			continue;
679 		if (vma->vm_flags & (1UL << i)) {
680 			seq_printf(m, "%c%c ",
681 				   mnemonics[i][0], mnemonics[i][1]);
682 		}
683 	}
684 	seq_putc(m, '\n');
685 }
686 
687 #ifdef CONFIG_HUGETLB_PAGE
688 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
689 				 unsigned long addr, unsigned long end,
690 				 struct mm_walk *walk)
691 {
692 	struct mem_size_stats *mss = walk->private;
693 	struct vm_area_struct *vma = walk->vma;
694 	struct page *page = NULL;
695 
696 	if (pte_present(*pte)) {
697 		page = vm_normal_page(vma, addr, *pte);
698 	} else if (is_swap_pte(*pte)) {
699 		swp_entry_t swpent = pte_to_swp_entry(*pte);
700 
701 		if (is_migration_entry(swpent))
702 			page = migration_entry_to_page(swpent);
703 	}
704 	if (page) {
705 		int mapcount = page_mapcount(page);
706 
707 		if (mapcount >= 2)
708 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
709 		else
710 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
711 	}
712 	return 0;
713 }
714 #endif /* HUGETLB_PAGE */
715 
716 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
717 {
718 }
719 
720 static int show_smap(struct seq_file *m, void *v, int is_pid)
721 {
722 	struct vm_area_struct *vma = v;
723 	struct mem_size_stats mss;
724 	struct mm_walk smaps_walk = {
725 		.pmd_entry = smaps_pte_range,
726 #ifdef CONFIG_HUGETLB_PAGE
727 		.hugetlb_entry = smaps_hugetlb_range,
728 #endif
729 		.mm = vma->vm_mm,
730 		.private = &mss,
731 	};
732 
733 	memset(&mss, 0, sizeof mss);
734 
735 #ifdef CONFIG_SHMEM
736 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
737 		/*
738 		 * For shared or readonly shmem mappings we know that all
739 		 * swapped out pages belong to the shmem object, and we can
740 		 * obtain the swap value much more efficiently. For private
741 		 * writable mappings, we might have COW pages that are
742 		 * not affected by the parent swapped out pages of the shmem
743 		 * object, so we have to distinguish them during the page walk.
744 		 * Unless we know that the shmem object (or the part mapped by
745 		 * our VMA) has no swapped out pages at all.
746 		 */
747 		unsigned long shmem_swapped = shmem_swap_usage(vma);
748 
749 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
750 					!(vma->vm_flags & VM_WRITE)) {
751 			mss.swap = shmem_swapped;
752 		} else {
753 			mss.check_shmem_swap = true;
754 			smaps_walk.pte_hole = smaps_pte_hole;
755 		}
756 	}
757 #endif
758 
759 	/* mmap_sem is held in m_start */
760 	walk_page_vma(vma, &smaps_walk);
761 
762 	show_map_vma(m, vma, is_pid);
763 
764 	seq_printf(m,
765 		   "Size:           %8lu kB\n"
766 		   "Rss:            %8lu kB\n"
767 		   "Pss:            %8lu kB\n"
768 		   "Shared_Clean:   %8lu kB\n"
769 		   "Shared_Dirty:   %8lu kB\n"
770 		   "Private_Clean:  %8lu kB\n"
771 		   "Private_Dirty:  %8lu kB\n"
772 		   "Referenced:     %8lu kB\n"
773 		   "Anonymous:      %8lu kB\n"
774 		   "LazyFree:       %8lu kB\n"
775 		   "AnonHugePages:  %8lu kB\n"
776 		   "ShmemPmdMapped: %8lu kB\n"
777 		   "Shared_Hugetlb: %8lu kB\n"
778 		   "Private_Hugetlb: %7lu kB\n"
779 		   "Swap:           %8lu kB\n"
780 		   "SwapPss:        %8lu kB\n"
781 		   "KernelPageSize: %8lu kB\n"
782 		   "MMUPageSize:    %8lu kB\n"
783 		   "Locked:         %8lu kB\n",
784 		   (vma->vm_end - vma->vm_start) >> 10,
785 		   mss.resident >> 10,
786 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
787 		   mss.shared_clean  >> 10,
788 		   mss.shared_dirty  >> 10,
789 		   mss.private_clean >> 10,
790 		   mss.private_dirty >> 10,
791 		   mss.referenced >> 10,
792 		   mss.anonymous >> 10,
793 		   mss.lazyfree >> 10,
794 		   mss.anonymous_thp >> 10,
795 		   mss.shmem_thp >> 10,
796 		   mss.shared_hugetlb >> 10,
797 		   mss.private_hugetlb >> 10,
798 		   mss.swap >> 10,
799 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
800 		   vma_kernel_pagesize(vma) >> 10,
801 		   vma_mmu_pagesize(vma) >> 10,
802 		   (vma->vm_flags & VM_LOCKED) ?
803 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
804 
805 	arch_show_smap(m, vma);
806 	show_smap_vma_flags(m, vma);
807 	m_cache_vma(m, vma);
808 	return 0;
809 }
810 
811 static int show_pid_smap(struct seq_file *m, void *v)
812 {
813 	return show_smap(m, v, 1);
814 }
815 
816 static int show_tid_smap(struct seq_file *m, void *v)
817 {
818 	return show_smap(m, v, 0);
819 }
820 
821 static const struct seq_operations proc_pid_smaps_op = {
822 	.start	= m_start,
823 	.next	= m_next,
824 	.stop	= m_stop,
825 	.show	= show_pid_smap
826 };
827 
828 static const struct seq_operations proc_tid_smaps_op = {
829 	.start	= m_start,
830 	.next	= m_next,
831 	.stop	= m_stop,
832 	.show	= show_tid_smap
833 };
834 
835 static int pid_smaps_open(struct inode *inode, struct file *file)
836 {
837 	return do_maps_open(inode, file, &proc_pid_smaps_op);
838 }
839 
840 static int tid_smaps_open(struct inode *inode, struct file *file)
841 {
842 	return do_maps_open(inode, file, &proc_tid_smaps_op);
843 }
844 
845 const struct file_operations proc_pid_smaps_operations = {
846 	.open		= pid_smaps_open,
847 	.read		= seq_read,
848 	.llseek		= seq_lseek,
849 	.release	= proc_map_release,
850 };
851 
852 const struct file_operations proc_tid_smaps_operations = {
853 	.open		= tid_smaps_open,
854 	.read		= seq_read,
855 	.llseek		= seq_lseek,
856 	.release	= proc_map_release,
857 };
858 
859 enum clear_refs_types {
860 	CLEAR_REFS_ALL = 1,
861 	CLEAR_REFS_ANON,
862 	CLEAR_REFS_MAPPED,
863 	CLEAR_REFS_SOFT_DIRTY,
864 	CLEAR_REFS_MM_HIWATER_RSS,
865 	CLEAR_REFS_LAST,
866 };
867 
868 struct clear_refs_private {
869 	enum clear_refs_types type;
870 };
871 
872 #ifdef CONFIG_MEM_SOFT_DIRTY
873 static inline void clear_soft_dirty(struct vm_area_struct *vma,
874 		unsigned long addr, pte_t *pte)
875 {
876 	/*
877 	 * The soft-dirty tracker uses #PF-s to catch writes
878 	 * to pages, so write-protect the pte as well. See the
879 	 * Documentation/vm/soft-dirty.txt for full description
880 	 * of how soft-dirty works.
881 	 */
882 	pte_t ptent = *pte;
883 
884 	if (pte_present(ptent)) {
885 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
886 		ptent = pte_wrprotect(ptent);
887 		ptent = pte_clear_soft_dirty(ptent);
888 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
889 	} else if (is_swap_pte(ptent)) {
890 		ptent = pte_swp_clear_soft_dirty(ptent);
891 		set_pte_at(vma->vm_mm, addr, pte, ptent);
892 	}
893 }
894 #else
895 static inline void clear_soft_dirty(struct vm_area_struct *vma,
896 		unsigned long addr, pte_t *pte)
897 {
898 }
899 #endif
900 
901 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
902 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
903 		unsigned long addr, pmd_t *pmdp)
904 {
905 	pmd_t pmd = *pmdp;
906 
907 	/* See comment in change_huge_pmd() */
908 	pmdp_invalidate(vma, addr, pmdp);
909 	if (pmd_dirty(*pmdp))
910 		pmd = pmd_mkdirty(pmd);
911 	if (pmd_young(*pmdp))
912 		pmd = pmd_mkyoung(pmd);
913 
914 	pmd = pmd_wrprotect(pmd);
915 	pmd = pmd_clear_soft_dirty(pmd);
916 
917 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
918 }
919 #else
920 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
921 		unsigned long addr, pmd_t *pmdp)
922 {
923 }
924 #endif
925 
926 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
927 				unsigned long end, struct mm_walk *walk)
928 {
929 	struct clear_refs_private *cp = walk->private;
930 	struct vm_area_struct *vma = walk->vma;
931 	pte_t *pte, ptent;
932 	spinlock_t *ptl;
933 	struct page *page;
934 
935 	ptl = pmd_trans_huge_lock(pmd, vma);
936 	if (ptl) {
937 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
938 			clear_soft_dirty_pmd(vma, addr, pmd);
939 			goto out;
940 		}
941 
942 		page = pmd_page(*pmd);
943 
944 		/* Clear accessed and referenced bits. */
945 		pmdp_test_and_clear_young(vma, addr, pmd);
946 		test_and_clear_page_young(page);
947 		ClearPageReferenced(page);
948 out:
949 		spin_unlock(ptl);
950 		return 0;
951 	}
952 
953 	if (pmd_trans_unstable(pmd))
954 		return 0;
955 
956 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
957 	for (; addr != end; pte++, addr += PAGE_SIZE) {
958 		ptent = *pte;
959 
960 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
961 			clear_soft_dirty(vma, addr, pte);
962 			continue;
963 		}
964 
965 		if (!pte_present(ptent))
966 			continue;
967 
968 		page = vm_normal_page(vma, addr, ptent);
969 		if (!page)
970 			continue;
971 
972 		/* Clear accessed and referenced bits. */
973 		ptep_test_and_clear_young(vma, addr, pte);
974 		test_and_clear_page_young(page);
975 		ClearPageReferenced(page);
976 	}
977 	pte_unmap_unlock(pte - 1, ptl);
978 	cond_resched();
979 	return 0;
980 }
981 
982 static int clear_refs_test_walk(unsigned long start, unsigned long end,
983 				struct mm_walk *walk)
984 {
985 	struct clear_refs_private *cp = walk->private;
986 	struct vm_area_struct *vma = walk->vma;
987 
988 	if (vma->vm_flags & VM_PFNMAP)
989 		return 1;
990 
991 	/*
992 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
993 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
994 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
995 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
996 	 */
997 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
998 		return 1;
999 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1000 		return 1;
1001 	return 0;
1002 }
1003 
1004 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1005 				size_t count, loff_t *ppos)
1006 {
1007 	struct task_struct *task;
1008 	char buffer[PROC_NUMBUF];
1009 	struct mm_struct *mm;
1010 	struct vm_area_struct *vma;
1011 	enum clear_refs_types type;
1012 	struct mmu_gather tlb;
1013 	int itype;
1014 	int rv;
1015 
1016 	memset(buffer, 0, sizeof(buffer));
1017 	if (count > sizeof(buffer) - 1)
1018 		count = sizeof(buffer) - 1;
1019 	if (copy_from_user(buffer, buf, count))
1020 		return -EFAULT;
1021 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1022 	if (rv < 0)
1023 		return rv;
1024 	type = (enum clear_refs_types)itype;
1025 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1026 		return -EINVAL;
1027 
1028 	task = get_proc_task(file_inode(file));
1029 	if (!task)
1030 		return -ESRCH;
1031 	mm = get_task_mm(task);
1032 	if (mm) {
1033 		struct clear_refs_private cp = {
1034 			.type = type,
1035 		};
1036 		struct mm_walk clear_refs_walk = {
1037 			.pmd_entry = clear_refs_pte_range,
1038 			.test_walk = clear_refs_test_walk,
1039 			.mm = mm,
1040 			.private = &cp,
1041 		};
1042 
1043 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1044 			if (down_write_killable(&mm->mmap_sem)) {
1045 				count = -EINTR;
1046 				goto out_mm;
1047 			}
1048 
1049 			/*
1050 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1051 			 * resident set size to this mm's current rss value.
1052 			 */
1053 			reset_mm_hiwater_rss(mm);
1054 			up_write(&mm->mmap_sem);
1055 			goto out_mm;
1056 		}
1057 
1058 		down_read(&mm->mmap_sem);
1059 		tlb_gather_mmu(&tlb, mm, 0, -1);
1060 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1061 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1062 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1063 					continue;
1064 				up_read(&mm->mmap_sem);
1065 				if (down_write_killable(&mm->mmap_sem)) {
1066 					count = -EINTR;
1067 					goto out_mm;
1068 				}
1069 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1070 					vma->vm_flags &= ~VM_SOFTDIRTY;
1071 					vma_set_page_prot(vma);
1072 				}
1073 				downgrade_write(&mm->mmap_sem);
1074 				break;
1075 			}
1076 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1077 		}
1078 		walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1079 		if (type == CLEAR_REFS_SOFT_DIRTY)
1080 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1081 		tlb_finish_mmu(&tlb, 0, -1);
1082 		up_read(&mm->mmap_sem);
1083 out_mm:
1084 		mmput(mm);
1085 	}
1086 	put_task_struct(task);
1087 
1088 	return count;
1089 }
1090 
1091 const struct file_operations proc_clear_refs_operations = {
1092 	.write		= clear_refs_write,
1093 	.llseek		= noop_llseek,
1094 };
1095 
1096 typedef struct {
1097 	u64 pme;
1098 } pagemap_entry_t;
1099 
1100 struct pagemapread {
1101 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1102 	pagemap_entry_t *buffer;
1103 	bool show_pfn;
1104 };
1105 
1106 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1107 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1108 
1109 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1110 #define PM_PFRAME_BITS		55
1111 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1112 #define PM_SOFT_DIRTY		BIT_ULL(55)
1113 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1114 #define PM_FILE			BIT_ULL(61)
1115 #define PM_SWAP			BIT_ULL(62)
1116 #define PM_PRESENT		BIT_ULL(63)
1117 
1118 #define PM_END_OF_BUFFER    1
1119 
1120 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1121 {
1122 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1123 }
1124 
1125 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1126 			  struct pagemapread *pm)
1127 {
1128 	pm->buffer[pm->pos++] = *pme;
1129 	if (pm->pos >= pm->len)
1130 		return PM_END_OF_BUFFER;
1131 	return 0;
1132 }
1133 
1134 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1135 				struct mm_walk *walk)
1136 {
1137 	struct pagemapread *pm = walk->private;
1138 	unsigned long addr = start;
1139 	int err = 0;
1140 
1141 	while (addr < end) {
1142 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1143 		pagemap_entry_t pme = make_pme(0, 0);
1144 		/* End of address space hole, which we mark as non-present. */
1145 		unsigned long hole_end;
1146 
1147 		if (vma)
1148 			hole_end = min(end, vma->vm_start);
1149 		else
1150 			hole_end = end;
1151 
1152 		for (; addr < hole_end; addr += PAGE_SIZE) {
1153 			err = add_to_pagemap(addr, &pme, pm);
1154 			if (err)
1155 				goto out;
1156 		}
1157 
1158 		if (!vma)
1159 			break;
1160 
1161 		/* Addresses in the VMA. */
1162 		if (vma->vm_flags & VM_SOFTDIRTY)
1163 			pme = make_pme(0, PM_SOFT_DIRTY);
1164 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1165 			err = add_to_pagemap(addr, &pme, pm);
1166 			if (err)
1167 				goto out;
1168 		}
1169 	}
1170 out:
1171 	return err;
1172 }
1173 
1174 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1175 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1176 {
1177 	u64 frame = 0, flags = 0;
1178 	struct page *page = NULL;
1179 
1180 	if (pte_present(pte)) {
1181 		if (pm->show_pfn)
1182 			frame = pte_pfn(pte);
1183 		flags |= PM_PRESENT;
1184 		page = vm_normal_page(vma, addr, pte);
1185 		if (pte_soft_dirty(pte))
1186 			flags |= PM_SOFT_DIRTY;
1187 	} else if (is_swap_pte(pte)) {
1188 		swp_entry_t entry;
1189 		if (pte_swp_soft_dirty(pte))
1190 			flags |= PM_SOFT_DIRTY;
1191 		entry = pte_to_swp_entry(pte);
1192 		frame = swp_type(entry) |
1193 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1194 		flags |= PM_SWAP;
1195 		if (is_migration_entry(entry))
1196 			page = migration_entry_to_page(entry);
1197 	}
1198 
1199 	if (page && !PageAnon(page))
1200 		flags |= PM_FILE;
1201 	if (page && page_mapcount(page) == 1)
1202 		flags |= PM_MMAP_EXCLUSIVE;
1203 	if (vma->vm_flags & VM_SOFTDIRTY)
1204 		flags |= PM_SOFT_DIRTY;
1205 
1206 	return make_pme(frame, flags);
1207 }
1208 
1209 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1210 			     struct mm_walk *walk)
1211 {
1212 	struct vm_area_struct *vma = walk->vma;
1213 	struct pagemapread *pm = walk->private;
1214 	spinlock_t *ptl;
1215 	pte_t *pte, *orig_pte;
1216 	int err = 0;
1217 
1218 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1219 	ptl = pmd_trans_huge_lock(pmdp, vma);
1220 	if (ptl) {
1221 		u64 flags = 0, frame = 0;
1222 		pmd_t pmd = *pmdp;
1223 
1224 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1225 			flags |= PM_SOFT_DIRTY;
1226 
1227 		/*
1228 		 * Currently pmd for thp is always present because thp
1229 		 * can not be swapped-out, migrated, or HWPOISONed
1230 		 * (split in such cases instead.)
1231 		 * This if-check is just to prepare for future implementation.
1232 		 */
1233 		if (pmd_present(pmd)) {
1234 			struct page *page = pmd_page(pmd);
1235 
1236 			if (page_mapcount(page) == 1)
1237 				flags |= PM_MMAP_EXCLUSIVE;
1238 
1239 			flags |= PM_PRESENT;
1240 			if (pm->show_pfn)
1241 				frame = pmd_pfn(pmd) +
1242 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1243 		}
1244 
1245 		for (; addr != end; addr += PAGE_SIZE) {
1246 			pagemap_entry_t pme = make_pme(frame, flags);
1247 
1248 			err = add_to_pagemap(addr, &pme, pm);
1249 			if (err)
1250 				break;
1251 			if (pm->show_pfn && (flags & PM_PRESENT))
1252 				frame++;
1253 		}
1254 		spin_unlock(ptl);
1255 		return err;
1256 	}
1257 
1258 	if (pmd_trans_unstable(pmdp))
1259 		return 0;
1260 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1261 
1262 	/*
1263 	 * We can assume that @vma always points to a valid one and @end never
1264 	 * goes beyond vma->vm_end.
1265 	 */
1266 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1267 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1268 		pagemap_entry_t pme;
1269 
1270 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1271 		err = add_to_pagemap(addr, &pme, pm);
1272 		if (err)
1273 			break;
1274 	}
1275 	pte_unmap_unlock(orig_pte, ptl);
1276 
1277 	cond_resched();
1278 
1279 	return err;
1280 }
1281 
1282 #ifdef CONFIG_HUGETLB_PAGE
1283 /* This function walks within one hugetlb entry in the single call */
1284 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1285 				 unsigned long addr, unsigned long end,
1286 				 struct mm_walk *walk)
1287 {
1288 	struct pagemapread *pm = walk->private;
1289 	struct vm_area_struct *vma = walk->vma;
1290 	u64 flags = 0, frame = 0;
1291 	int err = 0;
1292 	pte_t pte;
1293 
1294 	if (vma->vm_flags & VM_SOFTDIRTY)
1295 		flags |= PM_SOFT_DIRTY;
1296 
1297 	pte = huge_ptep_get(ptep);
1298 	if (pte_present(pte)) {
1299 		struct page *page = pte_page(pte);
1300 
1301 		if (!PageAnon(page))
1302 			flags |= PM_FILE;
1303 
1304 		if (page_mapcount(page) == 1)
1305 			flags |= PM_MMAP_EXCLUSIVE;
1306 
1307 		flags |= PM_PRESENT;
1308 		if (pm->show_pfn)
1309 			frame = pte_pfn(pte) +
1310 				((addr & ~hmask) >> PAGE_SHIFT);
1311 	}
1312 
1313 	for (; addr != end; addr += PAGE_SIZE) {
1314 		pagemap_entry_t pme = make_pme(frame, flags);
1315 
1316 		err = add_to_pagemap(addr, &pme, pm);
1317 		if (err)
1318 			return err;
1319 		if (pm->show_pfn && (flags & PM_PRESENT))
1320 			frame++;
1321 	}
1322 
1323 	cond_resched();
1324 
1325 	return err;
1326 }
1327 #endif /* HUGETLB_PAGE */
1328 
1329 /*
1330  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1331  *
1332  * For each page in the address space, this file contains one 64-bit entry
1333  * consisting of the following:
1334  *
1335  * Bits 0-54  page frame number (PFN) if present
1336  * Bits 0-4   swap type if swapped
1337  * Bits 5-54  swap offset if swapped
1338  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1339  * Bit  56    page exclusively mapped
1340  * Bits 57-60 zero
1341  * Bit  61    page is file-page or shared-anon
1342  * Bit  62    page swapped
1343  * Bit  63    page present
1344  *
1345  * If the page is not present but in swap, then the PFN contains an
1346  * encoding of the swap file number and the page's offset into the
1347  * swap. Unmapped pages return a null PFN. This allows determining
1348  * precisely which pages are mapped (or in swap) and comparing mapped
1349  * pages between processes.
1350  *
1351  * Efficient users of this interface will use /proc/pid/maps to
1352  * determine which areas of memory are actually mapped and llseek to
1353  * skip over unmapped regions.
1354  */
1355 static ssize_t pagemap_read(struct file *file, char __user *buf,
1356 			    size_t count, loff_t *ppos)
1357 {
1358 	struct mm_struct *mm = file->private_data;
1359 	struct pagemapread pm;
1360 	struct mm_walk pagemap_walk = {};
1361 	unsigned long src;
1362 	unsigned long svpfn;
1363 	unsigned long start_vaddr;
1364 	unsigned long end_vaddr;
1365 	int ret = 0, copied = 0;
1366 
1367 	if (!mm || !mmget_not_zero(mm))
1368 		goto out;
1369 
1370 	ret = -EINVAL;
1371 	/* file position must be aligned */
1372 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1373 		goto out_mm;
1374 
1375 	ret = 0;
1376 	if (!count)
1377 		goto out_mm;
1378 
1379 	/* do not disclose physical addresses: attack vector */
1380 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1381 
1382 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1383 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1384 	ret = -ENOMEM;
1385 	if (!pm.buffer)
1386 		goto out_mm;
1387 
1388 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1389 	pagemap_walk.pte_hole = pagemap_pte_hole;
1390 #ifdef CONFIG_HUGETLB_PAGE
1391 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1392 #endif
1393 	pagemap_walk.mm = mm;
1394 	pagemap_walk.private = &pm;
1395 
1396 	src = *ppos;
1397 	svpfn = src / PM_ENTRY_BYTES;
1398 	start_vaddr = svpfn << PAGE_SHIFT;
1399 	end_vaddr = mm->task_size;
1400 
1401 	/* watch out for wraparound */
1402 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1403 		start_vaddr = end_vaddr;
1404 
1405 	/*
1406 	 * The odds are that this will stop walking way
1407 	 * before end_vaddr, because the length of the
1408 	 * user buffer is tracked in "pm", and the walk
1409 	 * will stop when we hit the end of the buffer.
1410 	 */
1411 	ret = 0;
1412 	while (count && (start_vaddr < end_vaddr)) {
1413 		int len;
1414 		unsigned long end;
1415 
1416 		pm.pos = 0;
1417 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1418 		/* overflow ? */
1419 		if (end < start_vaddr || end > end_vaddr)
1420 			end = end_vaddr;
1421 		down_read(&mm->mmap_sem);
1422 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1423 		up_read(&mm->mmap_sem);
1424 		start_vaddr = end;
1425 
1426 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1427 		if (copy_to_user(buf, pm.buffer, len)) {
1428 			ret = -EFAULT;
1429 			goto out_free;
1430 		}
1431 		copied += len;
1432 		buf += len;
1433 		count -= len;
1434 	}
1435 	*ppos += copied;
1436 	if (!ret || ret == PM_END_OF_BUFFER)
1437 		ret = copied;
1438 
1439 out_free:
1440 	kfree(pm.buffer);
1441 out_mm:
1442 	mmput(mm);
1443 out:
1444 	return ret;
1445 }
1446 
1447 static int pagemap_open(struct inode *inode, struct file *file)
1448 {
1449 	struct mm_struct *mm;
1450 
1451 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1452 	if (IS_ERR(mm))
1453 		return PTR_ERR(mm);
1454 	file->private_data = mm;
1455 	return 0;
1456 }
1457 
1458 static int pagemap_release(struct inode *inode, struct file *file)
1459 {
1460 	struct mm_struct *mm = file->private_data;
1461 
1462 	if (mm)
1463 		mmdrop(mm);
1464 	return 0;
1465 }
1466 
1467 const struct file_operations proc_pagemap_operations = {
1468 	.llseek		= mem_lseek, /* borrow this */
1469 	.read		= pagemap_read,
1470 	.open		= pagemap_open,
1471 	.release	= pagemap_release,
1472 };
1473 #endif /* CONFIG_PROC_PAGE_MONITOR */
1474 
1475 #ifdef CONFIG_NUMA
1476 
1477 struct numa_maps {
1478 	unsigned long pages;
1479 	unsigned long anon;
1480 	unsigned long active;
1481 	unsigned long writeback;
1482 	unsigned long mapcount_max;
1483 	unsigned long dirty;
1484 	unsigned long swapcache;
1485 	unsigned long node[MAX_NUMNODES];
1486 };
1487 
1488 struct numa_maps_private {
1489 	struct proc_maps_private proc_maps;
1490 	struct numa_maps md;
1491 };
1492 
1493 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1494 			unsigned long nr_pages)
1495 {
1496 	int count = page_mapcount(page);
1497 
1498 	md->pages += nr_pages;
1499 	if (pte_dirty || PageDirty(page))
1500 		md->dirty += nr_pages;
1501 
1502 	if (PageSwapCache(page))
1503 		md->swapcache += nr_pages;
1504 
1505 	if (PageActive(page) || PageUnevictable(page))
1506 		md->active += nr_pages;
1507 
1508 	if (PageWriteback(page))
1509 		md->writeback += nr_pages;
1510 
1511 	if (PageAnon(page))
1512 		md->anon += nr_pages;
1513 
1514 	if (count > md->mapcount_max)
1515 		md->mapcount_max = count;
1516 
1517 	md->node[page_to_nid(page)] += nr_pages;
1518 }
1519 
1520 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1521 		unsigned long addr)
1522 {
1523 	struct page *page;
1524 	int nid;
1525 
1526 	if (!pte_present(pte))
1527 		return NULL;
1528 
1529 	page = vm_normal_page(vma, addr, pte);
1530 	if (!page)
1531 		return NULL;
1532 
1533 	if (PageReserved(page))
1534 		return NULL;
1535 
1536 	nid = page_to_nid(page);
1537 	if (!node_isset(nid, node_states[N_MEMORY]))
1538 		return NULL;
1539 
1540 	return page;
1541 }
1542 
1543 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1544 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1545 					      struct vm_area_struct *vma,
1546 					      unsigned long addr)
1547 {
1548 	struct page *page;
1549 	int nid;
1550 
1551 	if (!pmd_present(pmd))
1552 		return NULL;
1553 
1554 	page = vm_normal_page_pmd(vma, addr, pmd);
1555 	if (!page)
1556 		return NULL;
1557 
1558 	if (PageReserved(page))
1559 		return NULL;
1560 
1561 	nid = page_to_nid(page);
1562 	if (!node_isset(nid, node_states[N_MEMORY]))
1563 		return NULL;
1564 
1565 	return page;
1566 }
1567 #endif
1568 
1569 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1570 		unsigned long end, struct mm_walk *walk)
1571 {
1572 	struct numa_maps *md = walk->private;
1573 	struct vm_area_struct *vma = walk->vma;
1574 	spinlock_t *ptl;
1575 	pte_t *orig_pte;
1576 	pte_t *pte;
1577 
1578 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1579 	ptl = pmd_trans_huge_lock(pmd, vma);
1580 	if (ptl) {
1581 		struct page *page;
1582 
1583 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1584 		if (page)
1585 			gather_stats(page, md, pmd_dirty(*pmd),
1586 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1587 		spin_unlock(ptl);
1588 		return 0;
1589 	}
1590 
1591 	if (pmd_trans_unstable(pmd))
1592 		return 0;
1593 #endif
1594 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1595 	do {
1596 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1597 		if (!page)
1598 			continue;
1599 		gather_stats(page, md, pte_dirty(*pte), 1);
1600 
1601 	} while (pte++, addr += PAGE_SIZE, addr != end);
1602 	pte_unmap_unlock(orig_pte, ptl);
1603 	cond_resched();
1604 	return 0;
1605 }
1606 #ifdef CONFIG_HUGETLB_PAGE
1607 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1608 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1609 {
1610 	pte_t huge_pte = huge_ptep_get(pte);
1611 	struct numa_maps *md;
1612 	struct page *page;
1613 
1614 	if (!pte_present(huge_pte))
1615 		return 0;
1616 
1617 	page = pte_page(huge_pte);
1618 	if (!page)
1619 		return 0;
1620 
1621 	md = walk->private;
1622 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1623 	return 0;
1624 }
1625 
1626 #else
1627 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1628 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1629 {
1630 	return 0;
1631 }
1632 #endif
1633 
1634 /*
1635  * Display pages allocated per node and memory policy via /proc.
1636  */
1637 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1638 {
1639 	struct numa_maps_private *numa_priv = m->private;
1640 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1641 	struct vm_area_struct *vma = v;
1642 	struct numa_maps *md = &numa_priv->md;
1643 	struct file *file = vma->vm_file;
1644 	struct mm_struct *mm = vma->vm_mm;
1645 	struct mm_walk walk = {
1646 		.hugetlb_entry = gather_hugetlb_stats,
1647 		.pmd_entry = gather_pte_stats,
1648 		.private = md,
1649 		.mm = mm,
1650 	};
1651 	struct mempolicy *pol;
1652 	char buffer[64];
1653 	int nid;
1654 
1655 	if (!mm)
1656 		return 0;
1657 
1658 	/* Ensure we start with an empty set of numa_maps statistics. */
1659 	memset(md, 0, sizeof(*md));
1660 
1661 	pol = __get_vma_policy(vma, vma->vm_start);
1662 	if (pol) {
1663 		mpol_to_str(buffer, sizeof(buffer), pol);
1664 		mpol_cond_put(pol);
1665 	} else {
1666 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1667 	}
1668 
1669 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1670 
1671 	if (file) {
1672 		seq_puts(m, " file=");
1673 		seq_file_path(m, file, "\n\t= ");
1674 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1675 		seq_puts(m, " heap");
1676 	} else if (is_stack(proc_priv, vma)) {
1677 		seq_puts(m, " stack");
1678 	}
1679 
1680 	if (is_vm_hugetlb_page(vma))
1681 		seq_puts(m, " huge");
1682 
1683 	/* mmap_sem is held by m_start */
1684 	walk_page_vma(vma, &walk);
1685 
1686 	if (!md->pages)
1687 		goto out;
1688 
1689 	if (md->anon)
1690 		seq_printf(m, " anon=%lu", md->anon);
1691 
1692 	if (md->dirty)
1693 		seq_printf(m, " dirty=%lu", md->dirty);
1694 
1695 	if (md->pages != md->anon && md->pages != md->dirty)
1696 		seq_printf(m, " mapped=%lu", md->pages);
1697 
1698 	if (md->mapcount_max > 1)
1699 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1700 
1701 	if (md->swapcache)
1702 		seq_printf(m, " swapcache=%lu", md->swapcache);
1703 
1704 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1705 		seq_printf(m, " active=%lu", md->active);
1706 
1707 	if (md->writeback)
1708 		seq_printf(m, " writeback=%lu", md->writeback);
1709 
1710 	for_each_node_state(nid, N_MEMORY)
1711 		if (md->node[nid])
1712 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1713 
1714 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1715 out:
1716 	seq_putc(m, '\n');
1717 	m_cache_vma(m, vma);
1718 	return 0;
1719 }
1720 
1721 static int show_pid_numa_map(struct seq_file *m, void *v)
1722 {
1723 	return show_numa_map(m, v, 1);
1724 }
1725 
1726 static int show_tid_numa_map(struct seq_file *m, void *v)
1727 {
1728 	return show_numa_map(m, v, 0);
1729 }
1730 
1731 static const struct seq_operations proc_pid_numa_maps_op = {
1732 	.start  = m_start,
1733 	.next   = m_next,
1734 	.stop   = m_stop,
1735 	.show   = show_pid_numa_map,
1736 };
1737 
1738 static const struct seq_operations proc_tid_numa_maps_op = {
1739 	.start  = m_start,
1740 	.next   = m_next,
1741 	.stop   = m_stop,
1742 	.show   = show_tid_numa_map,
1743 };
1744 
1745 static int numa_maps_open(struct inode *inode, struct file *file,
1746 			  const struct seq_operations *ops)
1747 {
1748 	return proc_maps_open(inode, file, ops,
1749 				sizeof(struct numa_maps_private));
1750 }
1751 
1752 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1753 {
1754 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1755 }
1756 
1757 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1758 {
1759 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1760 }
1761 
1762 const struct file_operations proc_pid_numa_maps_operations = {
1763 	.open		= pid_numa_maps_open,
1764 	.read		= seq_read,
1765 	.llseek		= seq_lseek,
1766 	.release	= proc_map_release,
1767 };
1768 
1769 const struct file_operations proc_tid_numa_maps_operations = {
1770 	.open		= tid_numa_maps_open,
1771 	.read		= seq_read,
1772 	.llseek		= seq_lseek,
1773 	.release	= proc_map_release,
1774 };
1775 #endif /* CONFIG_NUMA */
1776