xref: /openbmc/linux/fs/proc/task_mmu.c (revision 3f07c014)
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 
20 #include <asm/elf.h>
21 #include <linux/uaccess.h>
22 #include <asm/tlbflush.h>
23 #include "internal.h"
24 
25 void task_mem(struct seq_file *m, struct mm_struct *mm)
26 {
27 	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
28 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
29 
30 	anon = get_mm_counter(mm, MM_ANONPAGES);
31 	file = get_mm_counter(mm, MM_FILEPAGES);
32 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
33 
34 	/*
35 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
36 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
37 	 * collector of these hiwater stats must therefore get total_vm
38 	 * and rss too, which will usually be the higher.  Barriers? not
39 	 * worth the effort, such snapshots can always be inconsistent.
40 	 */
41 	hiwater_vm = total_vm = mm->total_vm;
42 	if (hiwater_vm < mm->hiwater_vm)
43 		hiwater_vm = mm->hiwater_vm;
44 	hiwater_rss = total_rss = anon + file + shmem;
45 	if (hiwater_rss < mm->hiwater_rss)
46 		hiwater_rss = mm->hiwater_rss;
47 
48 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
49 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
50 	swap = get_mm_counter(mm, MM_SWAPENTS);
51 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
52 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
53 	seq_printf(m,
54 		"VmPeak:\t%8lu kB\n"
55 		"VmSize:\t%8lu kB\n"
56 		"VmLck:\t%8lu kB\n"
57 		"VmPin:\t%8lu kB\n"
58 		"VmHWM:\t%8lu kB\n"
59 		"VmRSS:\t%8lu kB\n"
60 		"RssAnon:\t%8lu kB\n"
61 		"RssFile:\t%8lu kB\n"
62 		"RssShmem:\t%8lu kB\n"
63 		"VmData:\t%8lu kB\n"
64 		"VmStk:\t%8lu kB\n"
65 		"VmExe:\t%8lu kB\n"
66 		"VmLib:\t%8lu kB\n"
67 		"VmPTE:\t%8lu kB\n"
68 		"VmPMD:\t%8lu kB\n"
69 		"VmSwap:\t%8lu kB\n",
70 		hiwater_vm << (PAGE_SHIFT-10),
71 		total_vm << (PAGE_SHIFT-10),
72 		mm->locked_vm << (PAGE_SHIFT-10),
73 		mm->pinned_vm << (PAGE_SHIFT-10),
74 		hiwater_rss << (PAGE_SHIFT-10),
75 		total_rss << (PAGE_SHIFT-10),
76 		anon << (PAGE_SHIFT-10),
77 		file << (PAGE_SHIFT-10),
78 		shmem << (PAGE_SHIFT-10),
79 		mm->data_vm << (PAGE_SHIFT-10),
80 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
81 		ptes >> 10,
82 		pmds >> 10,
83 		swap << (PAGE_SHIFT-10));
84 	hugetlb_report_usage(m, mm);
85 }
86 
87 unsigned long task_vsize(struct mm_struct *mm)
88 {
89 	return PAGE_SIZE * mm->total_vm;
90 }
91 
92 unsigned long task_statm(struct mm_struct *mm,
93 			 unsigned long *shared, unsigned long *text,
94 			 unsigned long *data, unsigned long *resident)
95 {
96 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
97 			get_mm_counter(mm, MM_SHMEMPAGES);
98 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
99 								>> PAGE_SHIFT;
100 	*data = mm->data_vm + mm->stack_vm;
101 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
102 	return mm->total_vm;
103 }
104 
105 #ifdef CONFIG_NUMA
106 /*
107  * Save get_task_policy() for show_numa_map().
108  */
109 static void hold_task_mempolicy(struct proc_maps_private *priv)
110 {
111 	struct task_struct *task = priv->task;
112 
113 	task_lock(task);
114 	priv->task_mempolicy = get_task_policy(task);
115 	mpol_get(priv->task_mempolicy);
116 	task_unlock(task);
117 }
118 static void release_task_mempolicy(struct proc_maps_private *priv)
119 {
120 	mpol_put(priv->task_mempolicy);
121 }
122 #else
123 static void hold_task_mempolicy(struct proc_maps_private *priv)
124 {
125 }
126 static void release_task_mempolicy(struct proc_maps_private *priv)
127 {
128 }
129 #endif
130 
131 static void vma_stop(struct proc_maps_private *priv)
132 {
133 	struct mm_struct *mm = priv->mm;
134 
135 	release_task_mempolicy(priv);
136 	up_read(&mm->mmap_sem);
137 	mmput(mm);
138 }
139 
140 static struct vm_area_struct *
141 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
142 {
143 	if (vma == priv->tail_vma)
144 		return NULL;
145 	return vma->vm_next ?: priv->tail_vma;
146 }
147 
148 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
149 {
150 	if (m->count < m->size)	/* vma is copied successfully */
151 		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
152 }
153 
154 static void *m_start(struct seq_file *m, loff_t *ppos)
155 {
156 	struct proc_maps_private *priv = m->private;
157 	unsigned long last_addr = m->version;
158 	struct mm_struct *mm;
159 	struct vm_area_struct *vma;
160 	unsigned int pos = *ppos;
161 
162 	/* See m_cache_vma(). Zero at the start or after lseek. */
163 	if (last_addr == -1UL)
164 		return NULL;
165 
166 	priv->task = get_proc_task(priv->inode);
167 	if (!priv->task)
168 		return ERR_PTR(-ESRCH);
169 
170 	mm = priv->mm;
171 	if (!mm || !mmget_not_zero(mm))
172 		return NULL;
173 
174 	down_read(&mm->mmap_sem);
175 	hold_task_mempolicy(priv);
176 	priv->tail_vma = get_gate_vma(mm);
177 
178 	if (last_addr) {
179 		vma = find_vma(mm, last_addr - 1);
180 		if (vma && vma->vm_start <= last_addr)
181 			vma = m_next_vma(priv, vma);
182 		if (vma)
183 			return vma;
184 	}
185 
186 	m->version = 0;
187 	if (pos < mm->map_count) {
188 		for (vma = mm->mmap; pos; pos--) {
189 			m->version = vma->vm_start;
190 			vma = vma->vm_next;
191 		}
192 		return vma;
193 	}
194 
195 	/* we do not bother to update m->version in this case */
196 	if (pos == mm->map_count && priv->tail_vma)
197 		return priv->tail_vma;
198 
199 	vma_stop(priv);
200 	return NULL;
201 }
202 
203 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
204 {
205 	struct proc_maps_private *priv = m->private;
206 	struct vm_area_struct *next;
207 
208 	(*pos)++;
209 	next = m_next_vma(priv, v);
210 	if (!next)
211 		vma_stop(priv);
212 	return next;
213 }
214 
215 static void m_stop(struct seq_file *m, void *v)
216 {
217 	struct proc_maps_private *priv = m->private;
218 
219 	if (!IS_ERR_OR_NULL(v))
220 		vma_stop(priv);
221 	if (priv->task) {
222 		put_task_struct(priv->task);
223 		priv->task = NULL;
224 	}
225 }
226 
227 static int proc_maps_open(struct inode *inode, struct file *file,
228 			const struct seq_operations *ops, int psize)
229 {
230 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
231 
232 	if (!priv)
233 		return -ENOMEM;
234 
235 	priv->inode = inode;
236 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
237 	if (IS_ERR(priv->mm)) {
238 		int err = PTR_ERR(priv->mm);
239 
240 		seq_release_private(inode, file);
241 		return err;
242 	}
243 
244 	return 0;
245 }
246 
247 static int proc_map_release(struct inode *inode, struct file *file)
248 {
249 	struct seq_file *seq = file->private_data;
250 	struct proc_maps_private *priv = seq->private;
251 
252 	if (priv->mm)
253 		mmdrop(priv->mm);
254 
255 	return seq_release_private(inode, file);
256 }
257 
258 static int do_maps_open(struct inode *inode, struct file *file,
259 			const struct seq_operations *ops)
260 {
261 	return proc_maps_open(inode, file, ops,
262 				sizeof(struct proc_maps_private));
263 }
264 
265 /*
266  * Indicate if the VMA is a stack for the given task; for
267  * /proc/PID/maps that is the stack of the main task.
268  */
269 static int is_stack(struct proc_maps_private *priv,
270 		    struct vm_area_struct *vma)
271 {
272 	/*
273 	 * We make no effort to guess what a given thread considers to be
274 	 * its "stack".  It's not even well-defined for programs written
275 	 * languages like Go.
276 	 */
277 	return vma->vm_start <= vma->vm_mm->start_stack &&
278 		vma->vm_end >= vma->vm_mm->start_stack;
279 }
280 
281 static void
282 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
283 {
284 	struct mm_struct *mm = vma->vm_mm;
285 	struct file *file = vma->vm_file;
286 	struct proc_maps_private *priv = m->private;
287 	vm_flags_t flags = vma->vm_flags;
288 	unsigned long ino = 0;
289 	unsigned long long pgoff = 0;
290 	unsigned long start, end;
291 	dev_t dev = 0;
292 	const char *name = NULL;
293 
294 	if (file) {
295 		struct inode *inode = file_inode(vma->vm_file);
296 		dev = inode->i_sb->s_dev;
297 		ino = inode->i_ino;
298 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
299 	}
300 
301 	/* We don't show the stack guard page in /proc/maps */
302 	start = vma->vm_start;
303 	if (stack_guard_page_start(vma, start))
304 		start += PAGE_SIZE;
305 	end = vma->vm_end;
306 	if (stack_guard_page_end(vma, end))
307 		end -= PAGE_SIZE;
308 
309 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
310 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
311 			start,
312 			end,
313 			flags & VM_READ ? 'r' : '-',
314 			flags & VM_WRITE ? 'w' : '-',
315 			flags & VM_EXEC ? 'x' : '-',
316 			flags & VM_MAYSHARE ? 's' : 'p',
317 			pgoff,
318 			MAJOR(dev), MINOR(dev), ino);
319 
320 	/*
321 	 * Print the dentry name for named mappings, and a
322 	 * special [heap] marker for the heap:
323 	 */
324 	if (file) {
325 		seq_pad(m, ' ');
326 		seq_file_path(m, file, "\n");
327 		goto done;
328 	}
329 
330 	if (vma->vm_ops && vma->vm_ops->name) {
331 		name = vma->vm_ops->name(vma);
332 		if (name)
333 			goto done;
334 	}
335 
336 	name = arch_vma_name(vma);
337 	if (!name) {
338 		if (!mm) {
339 			name = "[vdso]";
340 			goto done;
341 		}
342 
343 		if (vma->vm_start <= mm->brk &&
344 		    vma->vm_end >= mm->start_brk) {
345 			name = "[heap]";
346 			goto done;
347 		}
348 
349 		if (is_stack(priv, vma))
350 			name = "[stack]";
351 	}
352 
353 done:
354 	if (name) {
355 		seq_pad(m, ' ');
356 		seq_puts(m, name);
357 	}
358 	seq_putc(m, '\n');
359 }
360 
361 static int show_map(struct seq_file *m, void *v, int is_pid)
362 {
363 	show_map_vma(m, v, is_pid);
364 	m_cache_vma(m, v);
365 	return 0;
366 }
367 
368 static int show_pid_map(struct seq_file *m, void *v)
369 {
370 	return show_map(m, v, 1);
371 }
372 
373 static int show_tid_map(struct seq_file *m, void *v)
374 {
375 	return show_map(m, v, 0);
376 }
377 
378 static const struct seq_operations proc_pid_maps_op = {
379 	.start	= m_start,
380 	.next	= m_next,
381 	.stop	= m_stop,
382 	.show	= show_pid_map
383 };
384 
385 static const struct seq_operations proc_tid_maps_op = {
386 	.start	= m_start,
387 	.next	= m_next,
388 	.stop	= m_stop,
389 	.show	= show_tid_map
390 };
391 
392 static int pid_maps_open(struct inode *inode, struct file *file)
393 {
394 	return do_maps_open(inode, file, &proc_pid_maps_op);
395 }
396 
397 static int tid_maps_open(struct inode *inode, struct file *file)
398 {
399 	return do_maps_open(inode, file, &proc_tid_maps_op);
400 }
401 
402 const struct file_operations proc_pid_maps_operations = {
403 	.open		= pid_maps_open,
404 	.read		= seq_read,
405 	.llseek		= seq_lseek,
406 	.release	= proc_map_release,
407 };
408 
409 const struct file_operations proc_tid_maps_operations = {
410 	.open		= tid_maps_open,
411 	.read		= seq_read,
412 	.llseek		= seq_lseek,
413 	.release	= proc_map_release,
414 };
415 
416 /*
417  * Proportional Set Size(PSS): my share of RSS.
418  *
419  * PSS of a process is the count of pages it has in memory, where each
420  * page is divided by the number of processes sharing it.  So if a
421  * process has 1000 pages all to itself, and 1000 shared with one other
422  * process, its PSS will be 1500.
423  *
424  * To keep (accumulated) division errors low, we adopt a 64bit
425  * fixed-point pss counter to minimize division errors. So (pss >>
426  * PSS_SHIFT) would be the real byte count.
427  *
428  * A shift of 12 before division means (assuming 4K page size):
429  * 	- 1M 3-user-pages add up to 8KB errors;
430  * 	- supports mapcount up to 2^24, or 16M;
431  * 	- supports PSS up to 2^52 bytes, or 4PB.
432  */
433 #define PSS_SHIFT 12
434 
435 #ifdef CONFIG_PROC_PAGE_MONITOR
436 struct mem_size_stats {
437 	unsigned long resident;
438 	unsigned long shared_clean;
439 	unsigned long shared_dirty;
440 	unsigned long private_clean;
441 	unsigned long private_dirty;
442 	unsigned long referenced;
443 	unsigned long anonymous;
444 	unsigned long anonymous_thp;
445 	unsigned long shmem_thp;
446 	unsigned long swap;
447 	unsigned long shared_hugetlb;
448 	unsigned long private_hugetlb;
449 	u64 pss;
450 	u64 swap_pss;
451 	bool check_shmem_swap;
452 };
453 
454 static void smaps_account(struct mem_size_stats *mss, struct page *page,
455 		bool compound, bool young, bool dirty)
456 {
457 	int i, nr = compound ? 1 << compound_order(page) : 1;
458 	unsigned long size = nr * PAGE_SIZE;
459 
460 	if (PageAnon(page))
461 		mss->anonymous += size;
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 		   "AnonHugePages:  %8lu kB\n"
775 		   "ShmemPmdMapped: %8lu kB\n"
776 		   "Shared_Hugetlb: %8lu kB\n"
777 		   "Private_Hugetlb: %7lu kB\n"
778 		   "Swap:           %8lu kB\n"
779 		   "SwapPss:        %8lu kB\n"
780 		   "KernelPageSize: %8lu kB\n"
781 		   "MMUPageSize:    %8lu kB\n"
782 		   "Locked:         %8lu kB\n",
783 		   (vma->vm_end - vma->vm_start) >> 10,
784 		   mss.resident >> 10,
785 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
786 		   mss.shared_clean  >> 10,
787 		   mss.shared_dirty  >> 10,
788 		   mss.private_clean >> 10,
789 		   mss.private_dirty >> 10,
790 		   mss.referenced >> 10,
791 		   mss.anonymous >> 10,
792 		   mss.anonymous_thp >> 10,
793 		   mss.shmem_thp >> 10,
794 		   mss.shared_hugetlb >> 10,
795 		   mss.private_hugetlb >> 10,
796 		   mss.swap >> 10,
797 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
798 		   vma_kernel_pagesize(vma) >> 10,
799 		   vma_mmu_pagesize(vma) >> 10,
800 		   (vma->vm_flags & VM_LOCKED) ?
801 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
802 
803 	arch_show_smap(m, vma);
804 	show_smap_vma_flags(m, vma);
805 	m_cache_vma(m, vma);
806 	return 0;
807 }
808 
809 static int show_pid_smap(struct seq_file *m, void *v)
810 {
811 	return show_smap(m, v, 1);
812 }
813 
814 static int show_tid_smap(struct seq_file *m, void *v)
815 {
816 	return show_smap(m, v, 0);
817 }
818 
819 static const struct seq_operations proc_pid_smaps_op = {
820 	.start	= m_start,
821 	.next	= m_next,
822 	.stop	= m_stop,
823 	.show	= show_pid_smap
824 };
825 
826 static const struct seq_operations proc_tid_smaps_op = {
827 	.start	= m_start,
828 	.next	= m_next,
829 	.stop	= m_stop,
830 	.show	= show_tid_smap
831 };
832 
833 static int pid_smaps_open(struct inode *inode, struct file *file)
834 {
835 	return do_maps_open(inode, file, &proc_pid_smaps_op);
836 }
837 
838 static int tid_smaps_open(struct inode *inode, struct file *file)
839 {
840 	return do_maps_open(inode, file, &proc_tid_smaps_op);
841 }
842 
843 const struct file_operations proc_pid_smaps_operations = {
844 	.open		= pid_smaps_open,
845 	.read		= seq_read,
846 	.llseek		= seq_lseek,
847 	.release	= proc_map_release,
848 };
849 
850 const struct file_operations proc_tid_smaps_operations = {
851 	.open		= tid_smaps_open,
852 	.read		= seq_read,
853 	.llseek		= seq_lseek,
854 	.release	= proc_map_release,
855 };
856 
857 enum clear_refs_types {
858 	CLEAR_REFS_ALL = 1,
859 	CLEAR_REFS_ANON,
860 	CLEAR_REFS_MAPPED,
861 	CLEAR_REFS_SOFT_DIRTY,
862 	CLEAR_REFS_MM_HIWATER_RSS,
863 	CLEAR_REFS_LAST,
864 };
865 
866 struct clear_refs_private {
867 	enum clear_refs_types type;
868 };
869 
870 #ifdef CONFIG_MEM_SOFT_DIRTY
871 static inline void clear_soft_dirty(struct vm_area_struct *vma,
872 		unsigned long addr, pte_t *pte)
873 {
874 	/*
875 	 * The soft-dirty tracker uses #PF-s to catch writes
876 	 * to pages, so write-protect the pte as well. See the
877 	 * Documentation/vm/soft-dirty.txt for full description
878 	 * of how soft-dirty works.
879 	 */
880 	pte_t ptent = *pte;
881 
882 	if (pte_present(ptent)) {
883 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
884 		ptent = pte_wrprotect(ptent);
885 		ptent = pte_clear_soft_dirty(ptent);
886 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
887 	} else if (is_swap_pte(ptent)) {
888 		ptent = pte_swp_clear_soft_dirty(ptent);
889 		set_pte_at(vma->vm_mm, addr, pte, ptent);
890 	}
891 }
892 #else
893 static inline void clear_soft_dirty(struct vm_area_struct *vma,
894 		unsigned long addr, pte_t *pte)
895 {
896 }
897 #endif
898 
899 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
900 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
901 		unsigned long addr, pmd_t *pmdp)
902 {
903 	pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
904 
905 	pmd = pmd_wrprotect(pmd);
906 	pmd = pmd_clear_soft_dirty(pmd);
907 
908 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
909 }
910 #else
911 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
912 		unsigned long addr, pmd_t *pmdp)
913 {
914 }
915 #endif
916 
917 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
918 				unsigned long end, struct mm_walk *walk)
919 {
920 	struct clear_refs_private *cp = walk->private;
921 	struct vm_area_struct *vma = walk->vma;
922 	pte_t *pte, ptent;
923 	spinlock_t *ptl;
924 	struct page *page;
925 
926 	ptl = pmd_trans_huge_lock(pmd, vma);
927 	if (ptl) {
928 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
929 			clear_soft_dirty_pmd(vma, addr, pmd);
930 			goto out;
931 		}
932 
933 		page = pmd_page(*pmd);
934 
935 		/* Clear accessed and referenced bits. */
936 		pmdp_test_and_clear_young(vma, addr, pmd);
937 		test_and_clear_page_young(page);
938 		ClearPageReferenced(page);
939 out:
940 		spin_unlock(ptl);
941 		return 0;
942 	}
943 
944 	if (pmd_trans_unstable(pmd))
945 		return 0;
946 
947 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
948 	for (; addr != end; pte++, addr += PAGE_SIZE) {
949 		ptent = *pte;
950 
951 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
952 			clear_soft_dirty(vma, addr, pte);
953 			continue;
954 		}
955 
956 		if (!pte_present(ptent))
957 			continue;
958 
959 		page = vm_normal_page(vma, addr, ptent);
960 		if (!page)
961 			continue;
962 
963 		/* Clear accessed and referenced bits. */
964 		ptep_test_and_clear_young(vma, addr, pte);
965 		test_and_clear_page_young(page);
966 		ClearPageReferenced(page);
967 	}
968 	pte_unmap_unlock(pte - 1, ptl);
969 	cond_resched();
970 	return 0;
971 }
972 
973 static int clear_refs_test_walk(unsigned long start, unsigned long end,
974 				struct mm_walk *walk)
975 {
976 	struct clear_refs_private *cp = walk->private;
977 	struct vm_area_struct *vma = walk->vma;
978 
979 	if (vma->vm_flags & VM_PFNMAP)
980 		return 1;
981 
982 	/*
983 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
984 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
985 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
986 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
987 	 */
988 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
989 		return 1;
990 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
991 		return 1;
992 	return 0;
993 }
994 
995 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
996 				size_t count, loff_t *ppos)
997 {
998 	struct task_struct *task;
999 	char buffer[PROC_NUMBUF];
1000 	struct mm_struct *mm;
1001 	struct vm_area_struct *vma;
1002 	enum clear_refs_types type;
1003 	int itype;
1004 	int rv;
1005 
1006 	memset(buffer, 0, sizeof(buffer));
1007 	if (count > sizeof(buffer) - 1)
1008 		count = sizeof(buffer) - 1;
1009 	if (copy_from_user(buffer, buf, count))
1010 		return -EFAULT;
1011 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1012 	if (rv < 0)
1013 		return rv;
1014 	type = (enum clear_refs_types)itype;
1015 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1016 		return -EINVAL;
1017 
1018 	task = get_proc_task(file_inode(file));
1019 	if (!task)
1020 		return -ESRCH;
1021 	mm = get_task_mm(task);
1022 	if (mm) {
1023 		struct clear_refs_private cp = {
1024 			.type = type,
1025 		};
1026 		struct mm_walk clear_refs_walk = {
1027 			.pmd_entry = clear_refs_pte_range,
1028 			.test_walk = clear_refs_test_walk,
1029 			.mm = mm,
1030 			.private = &cp,
1031 		};
1032 
1033 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1034 			if (down_write_killable(&mm->mmap_sem)) {
1035 				count = -EINTR;
1036 				goto out_mm;
1037 			}
1038 
1039 			/*
1040 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1041 			 * resident set size to this mm's current rss value.
1042 			 */
1043 			reset_mm_hiwater_rss(mm);
1044 			up_write(&mm->mmap_sem);
1045 			goto out_mm;
1046 		}
1047 
1048 		down_read(&mm->mmap_sem);
1049 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1050 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1051 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1052 					continue;
1053 				up_read(&mm->mmap_sem);
1054 				if (down_write_killable(&mm->mmap_sem)) {
1055 					count = -EINTR;
1056 					goto out_mm;
1057 				}
1058 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1059 					vma->vm_flags &= ~VM_SOFTDIRTY;
1060 					vma_set_page_prot(vma);
1061 				}
1062 				downgrade_write(&mm->mmap_sem);
1063 				break;
1064 			}
1065 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1066 		}
1067 		walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1068 		if (type == CLEAR_REFS_SOFT_DIRTY)
1069 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1070 		flush_tlb_mm(mm);
1071 		up_read(&mm->mmap_sem);
1072 out_mm:
1073 		mmput(mm);
1074 	}
1075 	put_task_struct(task);
1076 
1077 	return count;
1078 }
1079 
1080 const struct file_operations proc_clear_refs_operations = {
1081 	.write		= clear_refs_write,
1082 	.llseek		= noop_llseek,
1083 };
1084 
1085 typedef struct {
1086 	u64 pme;
1087 } pagemap_entry_t;
1088 
1089 struct pagemapread {
1090 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1091 	pagemap_entry_t *buffer;
1092 	bool show_pfn;
1093 };
1094 
1095 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1096 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1097 
1098 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1099 #define PM_PFRAME_BITS		55
1100 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1101 #define PM_SOFT_DIRTY		BIT_ULL(55)
1102 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1103 #define PM_FILE			BIT_ULL(61)
1104 #define PM_SWAP			BIT_ULL(62)
1105 #define PM_PRESENT		BIT_ULL(63)
1106 
1107 #define PM_END_OF_BUFFER    1
1108 
1109 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1110 {
1111 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1112 }
1113 
1114 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1115 			  struct pagemapread *pm)
1116 {
1117 	pm->buffer[pm->pos++] = *pme;
1118 	if (pm->pos >= pm->len)
1119 		return PM_END_OF_BUFFER;
1120 	return 0;
1121 }
1122 
1123 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1124 				struct mm_walk *walk)
1125 {
1126 	struct pagemapread *pm = walk->private;
1127 	unsigned long addr = start;
1128 	int err = 0;
1129 
1130 	while (addr < end) {
1131 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1132 		pagemap_entry_t pme = make_pme(0, 0);
1133 		/* End of address space hole, which we mark as non-present. */
1134 		unsigned long hole_end;
1135 
1136 		if (vma)
1137 			hole_end = min(end, vma->vm_start);
1138 		else
1139 			hole_end = end;
1140 
1141 		for (; addr < hole_end; addr += PAGE_SIZE) {
1142 			err = add_to_pagemap(addr, &pme, pm);
1143 			if (err)
1144 				goto out;
1145 		}
1146 
1147 		if (!vma)
1148 			break;
1149 
1150 		/* Addresses in the VMA. */
1151 		if (vma->vm_flags & VM_SOFTDIRTY)
1152 			pme = make_pme(0, PM_SOFT_DIRTY);
1153 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1154 			err = add_to_pagemap(addr, &pme, pm);
1155 			if (err)
1156 				goto out;
1157 		}
1158 	}
1159 out:
1160 	return err;
1161 }
1162 
1163 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1164 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1165 {
1166 	u64 frame = 0, flags = 0;
1167 	struct page *page = NULL;
1168 
1169 	if (pte_present(pte)) {
1170 		if (pm->show_pfn)
1171 			frame = pte_pfn(pte);
1172 		flags |= PM_PRESENT;
1173 		page = vm_normal_page(vma, addr, pte);
1174 		if (pte_soft_dirty(pte))
1175 			flags |= PM_SOFT_DIRTY;
1176 	} else if (is_swap_pte(pte)) {
1177 		swp_entry_t entry;
1178 		if (pte_swp_soft_dirty(pte))
1179 			flags |= PM_SOFT_DIRTY;
1180 		entry = pte_to_swp_entry(pte);
1181 		frame = swp_type(entry) |
1182 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1183 		flags |= PM_SWAP;
1184 		if (is_migration_entry(entry))
1185 			page = migration_entry_to_page(entry);
1186 	}
1187 
1188 	if (page && !PageAnon(page))
1189 		flags |= PM_FILE;
1190 	if (page && page_mapcount(page) == 1)
1191 		flags |= PM_MMAP_EXCLUSIVE;
1192 	if (vma->vm_flags & VM_SOFTDIRTY)
1193 		flags |= PM_SOFT_DIRTY;
1194 
1195 	return make_pme(frame, flags);
1196 }
1197 
1198 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1199 			     struct mm_walk *walk)
1200 {
1201 	struct vm_area_struct *vma = walk->vma;
1202 	struct pagemapread *pm = walk->private;
1203 	spinlock_t *ptl;
1204 	pte_t *pte, *orig_pte;
1205 	int err = 0;
1206 
1207 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1208 	ptl = pmd_trans_huge_lock(pmdp, vma);
1209 	if (ptl) {
1210 		u64 flags = 0, frame = 0;
1211 		pmd_t pmd = *pmdp;
1212 
1213 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1214 			flags |= PM_SOFT_DIRTY;
1215 
1216 		/*
1217 		 * Currently pmd for thp is always present because thp
1218 		 * can not be swapped-out, migrated, or HWPOISONed
1219 		 * (split in such cases instead.)
1220 		 * This if-check is just to prepare for future implementation.
1221 		 */
1222 		if (pmd_present(pmd)) {
1223 			struct page *page = pmd_page(pmd);
1224 
1225 			if (page_mapcount(page) == 1)
1226 				flags |= PM_MMAP_EXCLUSIVE;
1227 
1228 			flags |= PM_PRESENT;
1229 			if (pm->show_pfn)
1230 				frame = pmd_pfn(pmd) +
1231 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1232 		}
1233 
1234 		for (; addr != end; addr += PAGE_SIZE) {
1235 			pagemap_entry_t pme = make_pme(frame, flags);
1236 
1237 			err = add_to_pagemap(addr, &pme, pm);
1238 			if (err)
1239 				break;
1240 			if (pm->show_pfn && (flags & PM_PRESENT))
1241 				frame++;
1242 		}
1243 		spin_unlock(ptl);
1244 		return err;
1245 	}
1246 
1247 	if (pmd_trans_unstable(pmdp))
1248 		return 0;
1249 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1250 
1251 	/*
1252 	 * We can assume that @vma always points to a valid one and @end never
1253 	 * goes beyond vma->vm_end.
1254 	 */
1255 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1256 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1257 		pagemap_entry_t pme;
1258 
1259 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1260 		err = add_to_pagemap(addr, &pme, pm);
1261 		if (err)
1262 			break;
1263 	}
1264 	pte_unmap_unlock(orig_pte, ptl);
1265 
1266 	cond_resched();
1267 
1268 	return err;
1269 }
1270 
1271 #ifdef CONFIG_HUGETLB_PAGE
1272 /* This function walks within one hugetlb entry in the single call */
1273 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1274 				 unsigned long addr, unsigned long end,
1275 				 struct mm_walk *walk)
1276 {
1277 	struct pagemapread *pm = walk->private;
1278 	struct vm_area_struct *vma = walk->vma;
1279 	u64 flags = 0, frame = 0;
1280 	int err = 0;
1281 	pte_t pte;
1282 
1283 	if (vma->vm_flags & VM_SOFTDIRTY)
1284 		flags |= PM_SOFT_DIRTY;
1285 
1286 	pte = huge_ptep_get(ptep);
1287 	if (pte_present(pte)) {
1288 		struct page *page = pte_page(pte);
1289 
1290 		if (!PageAnon(page))
1291 			flags |= PM_FILE;
1292 
1293 		if (page_mapcount(page) == 1)
1294 			flags |= PM_MMAP_EXCLUSIVE;
1295 
1296 		flags |= PM_PRESENT;
1297 		if (pm->show_pfn)
1298 			frame = pte_pfn(pte) +
1299 				((addr & ~hmask) >> PAGE_SHIFT);
1300 	}
1301 
1302 	for (; addr != end; addr += PAGE_SIZE) {
1303 		pagemap_entry_t pme = make_pme(frame, flags);
1304 
1305 		err = add_to_pagemap(addr, &pme, pm);
1306 		if (err)
1307 			return err;
1308 		if (pm->show_pfn && (flags & PM_PRESENT))
1309 			frame++;
1310 	}
1311 
1312 	cond_resched();
1313 
1314 	return err;
1315 }
1316 #endif /* HUGETLB_PAGE */
1317 
1318 /*
1319  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1320  *
1321  * For each page in the address space, this file contains one 64-bit entry
1322  * consisting of the following:
1323  *
1324  * Bits 0-54  page frame number (PFN) if present
1325  * Bits 0-4   swap type if swapped
1326  * Bits 5-54  swap offset if swapped
1327  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1328  * Bit  56    page exclusively mapped
1329  * Bits 57-60 zero
1330  * Bit  61    page is file-page or shared-anon
1331  * Bit  62    page swapped
1332  * Bit  63    page present
1333  *
1334  * If the page is not present but in swap, then the PFN contains an
1335  * encoding of the swap file number and the page's offset into the
1336  * swap. Unmapped pages return a null PFN. This allows determining
1337  * precisely which pages are mapped (or in swap) and comparing mapped
1338  * pages between processes.
1339  *
1340  * Efficient users of this interface will use /proc/pid/maps to
1341  * determine which areas of memory are actually mapped and llseek to
1342  * skip over unmapped regions.
1343  */
1344 static ssize_t pagemap_read(struct file *file, char __user *buf,
1345 			    size_t count, loff_t *ppos)
1346 {
1347 	struct mm_struct *mm = file->private_data;
1348 	struct pagemapread pm;
1349 	struct mm_walk pagemap_walk = {};
1350 	unsigned long src;
1351 	unsigned long svpfn;
1352 	unsigned long start_vaddr;
1353 	unsigned long end_vaddr;
1354 	int ret = 0, copied = 0;
1355 
1356 	if (!mm || !mmget_not_zero(mm))
1357 		goto out;
1358 
1359 	ret = -EINVAL;
1360 	/* file position must be aligned */
1361 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1362 		goto out_mm;
1363 
1364 	ret = 0;
1365 	if (!count)
1366 		goto out_mm;
1367 
1368 	/* do not disclose physical addresses: attack vector */
1369 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1370 
1371 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1372 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1373 	ret = -ENOMEM;
1374 	if (!pm.buffer)
1375 		goto out_mm;
1376 
1377 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1378 	pagemap_walk.pte_hole = pagemap_pte_hole;
1379 #ifdef CONFIG_HUGETLB_PAGE
1380 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1381 #endif
1382 	pagemap_walk.mm = mm;
1383 	pagemap_walk.private = &pm;
1384 
1385 	src = *ppos;
1386 	svpfn = src / PM_ENTRY_BYTES;
1387 	start_vaddr = svpfn << PAGE_SHIFT;
1388 	end_vaddr = mm->task_size;
1389 
1390 	/* watch out for wraparound */
1391 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1392 		start_vaddr = end_vaddr;
1393 
1394 	/*
1395 	 * The odds are that this will stop walking way
1396 	 * before end_vaddr, because the length of the
1397 	 * user buffer is tracked in "pm", and the walk
1398 	 * will stop when we hit the end of the buffer.
1399 	 */
1400 	ret = 0;
1401 	while (count && (start_vaddr < end_vaddr)) {
1402 		int len;
1403 		unsigned long end;
1404 
1405 		pm.pos = 0;
1406 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1407 		/* overflow ? */
1408 		if (end < start_vaddr || end > end_vaddr)
1409 			end = end_vaddr;
1410 		down_read(&mm->mmap_sem);
1411 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1412 		up_read(&mm->mmap_sem);
1413 		start_vaddr = end;
1414 
1415 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1416 		if (copy_to_user(buf, pm.buffer, len)) {
1417 			ret = -EFAULT;
1418 			goto out_free;
1419 		}
1420 		copied += len;
1421 		buf += len;
1422 		count -= len;
1423 	}
1424 	*ppos += copied;
1425 	if (!ret || ret == PM_END_OF_BUFFER)
1426 		ret = copied;
1427 
1428 out_free:
1429 	kfree(pm.buffer);
1430 out_mm:
1431 	mmput(mm);
1432 out:
1433 	return ret;
1434 }
1435 
1436 static int pagemap_open(struct inode *inode, struct file *file)
1437 {
1438 	struct mm_struct *mm;
1439 
1440 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1441 	if (IS_ERR(mm))
1442 		return PTR_ERR(mm);
1443 	file->private_data = mm;
1444 	return 0;
1445 }
1446 
1447 static int pagemap_release(struct inode *inode, struct file *file)
1448 {
1449 	struct mm_struct *mm = file->private_data;
1450 
1451 	if (mm)
1452 		mmdrop(mm);
1453 	return 0;
1454 }
1455 
1456 const struct file_operations proc_pagemap_operations = {
1457 	.llseek		= mem_lseek, /* borrow this */
1458 	.read		= pagemap_read,
1459 	.open		= pagemap_open,
1460 	.release	= pagemap_release,
1461 };
1462 #endif /* CONFIG_PROC_PAGE_MONITOR */
1463 
1464 #ifdef CONFIG_NUMA
1465 
1466 struct numa_maps {
1467 	unsigned long pages;
1468 	unsigned long anon;
1469 	unsigned long active;
1470 	unsigned long writeback;
1471 	unsigned long mapcount_max;
1472 	unsigned long dirty;
1473 	unsigned long swapcache;
1474 	unsigned long node[MAX_NUMNODES];
1475 };
1476 
1477 struct numa_maps_private {
1478 	struct proc_maps_private proc_maps;
1479 	struct numa_maps md;
1480 };
1481 
1482 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1483 			unsigned long nr_pages)
1484 {
1485 	int count = page_mapcount(page);
1486 
1487 	md->pages += nr_pages;
1488 	if (pte_dirty || PageDirty(page))
1489 		md->dirty += nr_pages;
1490 
1491 	if (PageSwapCache(page))
1492 		md->swapcache += nr_pages;
1493 
1494 	if (PageActive(page) || PageUnevictable(page))
1495 		md->active += nr_pages;
1496 
1497 	if (PageWriteback(page))
1498 		md->writeback += nr_pages;
1499 
1500 	if (PageAnon(page))
1501 		md->anon += nr_pages;
1502 
1503 	if (count > md->mapcount_max)
1504 		md->mapcount_max = count;
1505 
1506 	md->node[page_to_nid(page)] += nr_pages;
1507 }
1508 
1509 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1510 		unsigned long addr)
1511 {
1512 	struct page *page;
1513 	int nid;
1514 
1515 	if (!pte_present(pte))
1516 		return NULL;
1517 
1518 	page = vm_normal_page(vma, addr, pte);
1519 	if (!page)
1520 		return NULL;
1521 
1522 	if (PageReserved(page))
1523 		return NULL;
1524 
1525 	nid = page_to_nid(page);
1526 	if (!node_isset(nid, node_states[N_MEMORY]))
1527 		return NULL;
1528 
1529 	return page;
1530 }
1531 
1532 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1533 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1534 					      struct vm_area_struct *vma,
1535 					      unsigned long addr)
1536 {
1537 	struct page *page;
1538 	int nid;
1539 
1540 	if (!pmd_present(pmd))
1541 		return NULL;
1542 
1543 	page = vm_normal_page_pmd(vma, addr, pmd);
1544 	if (!page)
1545 		return NULL;
1546 
1547 	if (PageReserved(page))
1548 		return NULL;
1549 
1550 	nid = page_to_nid(page);
1551 	if (!node_isset(nid, node_states[N_MEMORY]))
1552 		return NULL;
1553 
1554 	return page;
1555 }
1556 #endif
1557 
1558 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1559 		unsigned long end, struct mm_walk *walk)
1560 {
1561 	struct numa_maps *md = walk->private;
1562 	struct vm_area_struct *vma = walk->vma;
1563 	spinlock_t *ptl;
1564 	pte_t *orig_pte;
1565 	pte_t *pte;
1566 
1567 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1568 	ptl = pmd_trans_huge_lock(pmd, vma);
1569 	if (ptl) {
1570 		struct page *page;
1571 
1572 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1573 		if (page)
1574 			gather_stats(page, md, pmd_dirty(*pmd),
1575 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1576 		spin_unlock(ptl);
1577 		return 0;
1578 	}
1579 
1580 	if (pmd_trans_unstable(pmd))
1581 		return 0;
1582 #endif
1583 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1584 	do {
1585 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1586 		if (!page)
1587 			continue;
1588 		gather_stats(page, md, pte_dirty(*pte), 1);
1589 
1590 	} while (pte++, addr += PAGE_SIZE, addr != end);
1591 	pte_unmap_unlock(orig_pte, ptl);
1592 	cond_resched();
1593 	return 0;
1594 }
1595 #ifdef CONFIG_HUGETLB_PAGE
1596 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1597 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1598 {
1599 	pte_t huge_pte = huge_ptep_get(pte);
1600 	struct numa_maps *md;
1601 	struct page *page;
1602 
1603 	if (!pte_present(huge_pte))
1604 		return 0;
1605 
1606 	page = pte_page(huge_pte);
1607 	if (!page)
1608 		return 0;
1609 
1610 	md = walk->private;
1611 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1612 	return 0;
1613 }
1614 
1615 #else
1616 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1617 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1618 {
1619 	return 0;
1620 }
1621 #endif
1622 
1623 /*
1624  * Display pages allocated per node and memory policy via /proc.
1625  */
1626 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1627 {
1628 	struct numa_maps_private *numa_priv = m->private;
1629 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1630 	struct vm_area_struct *vma = v;
1631 	struct numa_maps *md = &numa_priv->md;
1632 	struct file *file = vma->vm_file;
1633 	struct mm_struct *mm = vma->vm_mm;
1634 	struct mm_walk walk = {
1635 		.hugetlb_entry = gather_hugetlb_stats,
1636 		.pmd_entry = gather_pte_stats,
1637 		.private = md,
1638 		.mm = mm,
1639 	};
1640 	struct mempolicy *pol;
1641 	char buffer[64];
1642 	int nid;
1643 
1644 	if (!mm)
1645 		return 0;
1646 
1647 	/* Ensure we start with an empty set of numa_maps statistics. */
1648 	memset(md, 0, sizeof(*md));
1649 
1650 	pol = __get_vma_policy(vma, vma->vm_start);
1651 	if (pol) {
1652 		mpol_to_str(buffer, sizeof(buffer), pol);
1653 		mpol_cond_put(pol);
1654 	} else {
1655 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1656 	}
1657 
1658 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1659 
1660 	if (file) {
1661 		seq_puts(m, " file=");
1662 		seq_file_path(m, file, "\n\t= ");
1663 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1664 		seq_puts(m, " heap");
1665 	} else if (is_stack(proc_priv, vma)) {
1666 		seq_puts(m, " stack");
1667 	}
1668 
1669 	if (is_vm_hugetlb_page(vma))
1670 		seq_puts(m, " huge");
1671 
1672 	/* mmap_sem is held by m_start */
1673 	walk_page_vma(vma, &walk);
1674 
1675 	if (!md->pages)
1676 		goto out;
1677 
1678 	if (md->anon)
1679 		seq_printf(m, " anon=%lu", md->anon);
1680 
1681 	if (md->dirty)
1682 		seq_printf(m, " dirty=%lu", md->dirty);
1683 
1684 	if (md->pages != md->anon && md->pages != md->dirty)
1685 		seq_printf(m, " mapped=%lu", md->pages);
1686 
1687 	if (md->mapcount_max > 1)
1688 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1689 
1690 	if (md->swapcache)
1691 		seq_printf(m, " swapcache=%lu", md->swapcache);
1692 
1693 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1694 		seq_printf(m, " active=%lu", md->active);
1695 
1696 	if (md->writeback)
1697 		seq_printf(m, " writeback=%lu", md->writeback);
1698 
1699 	for_each_node_state(nid, N_MEMORY)
1700 		if (md->node[nid])
1701 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1702 
1703 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1704 out:
1705 	seq_putc(m, '\n');
1706 	m_cache_vma(m, vma);
1707 	return 0;
1708 }
1709 
1710 static int show_pid_numa_map(struct seq_file *m, void *v)
1711 {
1712 	return show_numa_map(m, v, 1);
1713 }
1714 
1715 static int show_tid_numa_map(struct seq_file *m, void *v)
1716 {
1717 	return show_numa_map(m, v, 0);
1718 }
1719 
1720 static const struct seq_operations proc_pid_numa_maps_op = {
1721 	.start  = m_start,
1722 	.next   = m_next,
1723 	.stop   = m_stop,
1724 	.show   = show_pid_numa_map,
1725 };
1726 
1727 static const struct seq_operations proc_tid_numa_maps_op = {
1728 	.start  = m_start,
1729 	.next   = m_next,
1730 	.stop   = m_stop,
1731 	.show   = show_tid_numa_map,
1732 };
1733 
1734 static int numa_maps_open(struct inode *inode, struct file *file,
1735 			  const struct seq_operations *ops)
1736 {
1737 	return proc_maps_open(inode, file, ops,
1738 				sizeof(struct numa_maps_private));
1739 }
1740 
1741 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1742 {
1743 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1744 }
1745 
1746 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1747 {
1748 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1749 }
1750 
1751 const struct file_operations proc_pid_numa_maps_operations = {
1752 	.open		= pid_numa_maps_open,
1753 	.read		= seq_read,
1754 	.llseek		= seq_lseek,
1755 	.release	= proc_map_release,
1756 };
1757 
1758 const struct file_operations proc_tid_numa_maps_operations = {
1759 	.open		= tid_numa_maps_open,
1760 	.read		= seq_read,
1761 	.llseek		= seq_lseek,
1762 	.release	= proc_map_release,
1763 };
1764 #endif /* CONFIG_NUMA */
1765