xref: /openbmc/linux/fs/proc/task_mmu.c (revision 4f205687)
1 #include <linux/mm.h>
2 #include <linux/vmacache.h>
3 #include <linux/hugetlb.h>
4 #include <linux/huge_mm.h>
5 #include <linux/mount.h>
6 #include <linux/seq_file.h>
7 #include <linux/highmem.h>
8 #include <linux/ptrace.h>
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
11 #include <linux/mempolicy.h>
12 #include <linux/rmap.h>
13 #include <linux/swap.h>
14 #include <linux/swapops.h>
15 #include <linux/mmu_notifier.h>
16 #include <linux/page_idle.h>
17 #include <linux/shmem_fs.h>
18 
19 #include <asm/elf.h>
20 #include <asm/uaccess.h>
21 #include <asm/tlbflush.h>
22 #include "internal.h"
23 
24 void task_mem(struct seq_file *m, struct mm_struct *mm)
25 {
26 	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
27 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
28 
29 	anon = get_mm_counter(mm, MM_ANONPAGES);
30 	file = get_mm_counter(mm, MM_FILEPAGES);
31 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
32 
33 	/*
34 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
35 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
36 	 * collector of these hiwater stats must therefore get total_vm
37 	 * and rss too, which will usually be the higher.  Barriers? not
38 	 * worth the effort, such snapshots can always be inconsistent.
39 	 */
40 	hiwater_vm = total_vm = mm->total_vm;
41 	if (hiwater_vm < mm->hiwater_vm)
42 		hiwater_vm = mm->hiwater_vm;
43 	hiwater_rss = total_rss = anon + file + shmem;
44 	if (hiwater_rss < mm->hiwater_rss)
45 		hiwater_rss = mm->hiwater_rss;
46 
47 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
48 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
49 	swap = get_mm_counter(mm, MM_SWAPENTS);
50 	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
51 	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
52 	seq_printf(m,
53 		"VmPeak:\t%8lu kB\n"
54 		"VmSize:\t%8lu kB\n"
55 		"VmLck:\t%8lu kB\n"
56 		"VmPin:\t%8lu kB\n"
57 		"VmHWM:\t%8lu kB\n"
58 		"VmRSS:\t%8lu kB\n"
59 		"RssAnon:\t%8lu kB\n"
60 		"RssFile:\t%8lu kB\n"
61 		"RssShmem:\t%8lu kB\n"
62 		"VmData:\t%8lu kB\n"
63 		"VmStk:\t%8lu kB\n"
64 		"VmExe:\t%8lu kB\n"
65 		"VmLib:\t%8lu kB\n"
66 		"VmPTE:\t%8lu kB\n"
67 		"VmPMD:\t%8lu kB\n"
68 		"VmSwap:\t%8lu kB\n",
69 		hiwater_vm << (PAGE_SHIFT-10),
70 		total_vm << (PAGE_SHIFT-10),
71 		mm->locked_vm << (PAGE_SHIFT-10),
72 		mm->pinned_vm << (PAGE_SHIFT-10),
73 		hiwater_rss << (PAGE_SHIFT-10),
74 		total_rss << (PAGE_SHIFT-10),
75 		anon << (PAGE_SHIFT-10),
76 		file << (PAGE_SHIFT-10),
77 		shmem << (PAGE_SHIFT-10),
78 		mm->data_vm << (PAGE_SHIFT-10),
79 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
80 		ptes >> 10,
81 		pmds >> 10,
82 		swap << (PAGE_SHIFT-10));
83 	hugetlb_report_usage(m, mm);
84 }
85 
86 unsigned long task_vsize(struct mm_struct *mm)
87 {
88 	return PAGE_SIZE * mm->total_vm;
89 }
90 
91 unsigned long task_statm(struct mm_struct *mm,
92 			 unsigned long *shared, unsigned long *text,
93 			 unsigned long *data, unsigned long *resident)
94 {
95 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
96 			get_mm_counter(mm, MM_SHMEMPAGES);
97 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
98 								>> PAGE_SHIFT;
99 	*data = mm->data_vm + mm->stack_vm;
100 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
101 	return mm->total_vm;
102 }
103 
104 #ifdef CONFIG_NUMA
105 /*
106  * Save get_task_policy() for show_numa_map().
107  */
108 static void hold_task_mempolicy(struct proc_maps_private *priv)
109 {
110 	struct task_struct *task = priv->task;
111 
112 	task_lock(task);
113 	priv->task_mempolicy = get_task_policy(task);
114 	mpol_get(priv->task_mempolicy);
115 	task_unlock(task);
116 }
117 static void release_task_mempolicy(struct proc_maps_private *priv)
118 {
119 	mpol_put(priv->task_mempolicy);
120 }
121 #else
122 static void hold_task_mempolicy(struct proc_maps_private *priv)
123 {
124 }
125 static void release_task_mempolicy(struct proc_maps_private *priv)
126 {
127 }
128 #endif
129 
130 static void vma_stop(struct proc_maps_private *priv)
131 {
132 	struct mm_struct *mm = priv->mm;
133 
134 	release_task_mempolicy(priv);
135 	up_read(&mm->mmap_sem);
136 	mmput(mm);
137 }
138 
139 static struct vm_area_struct *
140 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
141 {
142 	if (vma == priv->tail_vma)
143 		return NULL;
144 	return vma->vm_next ?: priv->tail_vma;
145 }
146 
147 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
148 {
149 	if (m->count < m->size)	/* vma is copied successfully */
150 		m->version = m_next_vma(m->private, vma) ? vma->vm_start : -1UL;
151 }
152 
153 static void *m_start(struct seq_file *m, loff_t *ppos)
154 {
155 	struct proc_maps_private *priv = m->private;
156 	unsigned long last_addr = m->version;
157 	struct mm_struct *mm;
158 	struct vm_area_struct *vma;
159 	unsigned int pos = *ppos;
160 
161 	/* See m_cache_vma(). Zero at the start or after lseek. */
162 	if (last_addr == -1UL)
163 		return NULL;
164 
165 	priv->task = get_proc_task(priv->inode);
166 	if (!priv->task)
167 		return ERR_PTR(-ESRCH);
168 
169 	mm = priv->mm;
170 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
171 		return NULL;
172 
173 	down_read(&mm->mmap_sem);
174 	hold_task_mempolicy(priv);
175 	priv->tail_vma = get_gate_vma(mm);
176 
177 	if (last_addr) {
178 		vma = find_vma(mm, last_addr);
179 		if (vma && (vma = m_next_vma(priv, vma)))
180 			return vma;
181 	}
182 
183 	m->version = 0;
184 	if (pos < mm->map_count) {
185 		for (vma = mm->mmap; pos; pos--) {
186 			m->version = vma->vm_start;
187 			vma = vma->vm_next;
188 		}
189 		return vma;
190 	}
191 
192 	/* we do not bother to update m->version in this case */
193 	if (pos == mm->map_count && priv->tail_vma)
194 		return priv->tail_vma;
195 
196 	vma_stop(priv);
197 	return NULL;
198 }
199 
200 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
201 {
202 	struct proc_maps_private *priv = m->private;
203 	struct vm_area_struct *next;
204 
205 	(*pos)++;
206 	next = m_next_vma(priv, v);
207 	if (!next)
208 		vma_stop(priv);
209 	return next;
210 }
211 
212 static void m_stop(struct seq_file *m, void *v)
213 {
214 	struct proc_maps_private *priv = m->private;
215 
216 	if (!IS_ERR_OR_NULL(v))
217 		vma_stop(priv);
218 	if (priv->task) {
219 		put_task_struct(priv->task);
220 		priv->task = NULL;
221 	}
222 }
223 
224 static int proc_maps_open(struct inode *inode, struct file *file,
225 			const struct seq_operations *ops, int psize)
226 {
227 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
228 
229 	if (!priv)
230 		return -ENOMEM;
231 
232 	priv->inode = inode;
233 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
234 	if (IS_ERR(priv->mm)) {
235 		int err = PTR_ERR(priv->mm);
236 
237 		seq_release_private(inode, file);
238 		return err;
239 	}
240 
241 	return 0;
242 }
243 
244 static int proc_map_release(struct inode *inode, struct file *file)
245 {
246 	struct seq_file *seq = file->private_data;
247 	struct proc_maps_private *priv = seq->private;
248 
249 	if (priv->mm)
250 		mmdrop(priv->mm);
251 
252 	return seq_release_private(inode, file);
253 }
254 
255 static int do_maps_open(struct inode *inode, struct file *file,
256 			const struct seq_operations *ops)
257 {
258 	return proc_maps_open(inode, file, ops,
259 				sizeof(struct proc_maps_private));
260 }
261 
262 /*
263  * Indicate if the VMA is a stack for the given task; for
264  * /proc/PID/maps that is the stack of the main task.
265  */
266 static int is_stack(struct proc_maps_private *priv,
267 		    struct vm_area_struct *vma, int is_pid)
268 {
269 	int stack = 0;
270 
271 	if (is_pid) {
272 		stack = vma->vm_start <= vma->vm_mm->start_stack &&
273 			vma->vm_end >= vma->vm_mm->start_stack;
274 	} else {
275 		struct inode *inode = priv->inode;
276 		struct task_struct *task;
277 
278 		rcu_read_lock();
279 		task = pid_task(proc_pid(inode), PIDTYPE_PID);
280 		if (task)
281 			stack = vma_is_stack_for_task(vma, task);
282 		rcu_read_unlock();
283 	}
284 	return stack;
285 }
286 
287 static void
288 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
289 {
290 	struct mm_struct *mm = vma->vm_mm;
291 	struct file *file = vma->vm_file;
292 	struct proc_maps_private *priv = m->private;
293 	vm_flags_t flags = vma->vm_flags;
294 	unsigned long ino = 0;
295 	unsigned long long pgoff = 0;
296 	unsigned long start, end;
297 	dev_t dev = 0;
298 	const char *name = NULL;
299 
300 	if (file) {
301 		struct inode *inode = file_inode(vma->vm_file);
302 		dev = inode->i_sb->s_dev;
303 		ino = inode->i_ino;
304 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
305 	}
306 
307 	/* We don't show the stack guard page in /proc/maps */
308 	start = vma->vm_start;
309 	if (stack_guard_page_start(vma, start))
310 		start += PAGE_SIZE;
311 	end = vma->vm_end;
312 	if (stack_guard_page_end(vma, end))
313 		end -= PAGE_SIZE;
314 
315 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
316 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
317 			start,
318 			end,
319 			flags & VM_READ ? 'r' : '-',
320 			flags & VM_WRITE ? 'w' : '-',
321 			flags & VM_EXEC ? 'x' : '-',
322 			flags & VM_MAYSHARE ? 's' : 'p',
323 			pgoff,
324 			MAJOR(dev), MINOR(dev), ino);
325 
326 	/*
327 	 * Print the dentry name for named mappings, and a
328 	 * special [heap] marker for the heap:
329 	 */
330 	if (file) {
331 		seq_pad(m, ' ');
332 		seq_file_path(m, file, "\n");
333 		goto done;
334 	}
335 
336 	if (vma->vm_ops && vma->vm_ops->name) {
337 		name = vma->vm_ops->name(vma);
338 		if (name)
339 			goto done;
340 	}
341 
342 	name = arch_vma_name(vma);
343 	if (!name) {
344 		if (!mm) {
345 			name = "[vdso]";
346 			goto done;
347 		}
348 
349 		if (vma->vm_start <= mm->brk &&
350 		    vma->vm_end >= mm->start_brk) {
351 			name = "[heap]";
352 			goto done;
353 		}
354 
355 		if (is_stack(priv, vma, is_pid))
356 			name = "[stack]";
357 	}
358 
359 done:
360 	if (name) {
361 		seq_pad(m, ' ');
362 		seq_puts(m, name);
363 	}
364 	seq_putc(m, '\n');
365 }
366 
367 static int show_map(struct seq_file *m, void *v, int is_pid)
368 {
369 	show_map_vma(m, v, is_pid);
370 	m_cache_vma(m, v);
371 	return 0;
372 }
373 
374 static int show_pid_map(struct seq_file *m, void *v)
375 {
376 	return show_map(m, v, 1);
377 }
378 
379 static int show_tid_map(struct seq_file *m, void *v)
380 {
381 	return show_map(m, v, 0);
382 }
383 
384 static const struct seq_operations proc_pid_maps_op = {
385 	.start	= m_start,
386 	.next	= m_next,
387 	.stop	= m_stop,
388 	.show	= show_pid_map
389 };
390 
391 static const struct seq_operations proc_tid_maps_op = {
392 	.start	= m_start,
393 	.next	= m_next,
394 	.stop	= m_stop,
395 	.show	= show_tid_map
396 };
397 
398 static int pid_maps_open(struct inode *inode, struct file *file)
399 {
400 	return do_maps_open(inode, file, &proc_pid_maps_op);
401 }
402 
403 static int tid_maps_open(struct inode *inode, struct file *file)
404 {
405 	return do_maps_open(inode, file, &proc_tid_maps_op);
406 }
407 
408 const struct file_operations proc_pid_maps_operations = {
409 	.open		= pid_maps_open,
410 	.read		= seq_read,
411 	.llseek		= seq_lseek,
412 	.release	= proc_map_release,
413 };
414 
415 const struct file_operations proc_tid_maps_operations = {
416 	.open		= tid_maps_open,
417 	.read		= seq_read,
418 	.llseek		= seq_lseek,
419 	.release	= proc_map_release,
420 };
421 
422 /*
423  * Proportional Set Size(PSS): my share of RSS.
424  *
425  * PSS of a process is the count of pages it has in memory, where each
426  * page is divided by the number of processes sharing it.  So if a
427  * process has 1000 pages all to itself, and 1000 shared with one other
428  * process, its PSS will be 1500.
429  *
430  * To keep (accumulated) division errors low, we adopt a 64bit
431  * fixed-point pss counter to minimize division errors. So (pss >>
432  * PSS_SHIFT) would be the real byte count.
433  *
434  * A shift of 12 before division means (assuming 4K page size):
435  * 	- 1M 3-user-pages add up to 8KB errors;
436  * 	- supports mapcount up to 2^24, or 16M;
437  * 	- supports PSS up to 2^52 bytes, or 4PB.
438  */
439 #define PSS_SHIFT 12
440 
441 #ifdef CONFIG_PROC_PAGE_MONITOR
442 struct mem_size_stats {
443 	unsigned long resident;
444 	unsigned long shared_clean;
445 	unsigned long shared_dirty;
446 	unsigned long private_clean;
447 	unsigned long private_dirty;
448 	unsigned long referenced;
449 	unsigned long anonymous;
450 	unsigned long anonymous_thp;
451 	unsigned long swap;
452 	unsigned long shared_hugetlb;
453 	unsigned long private_hugetlb;
454 	u64 pss;
455 	u64 swap_pss;
456 	bool check_shmem_swap;
457 };
458 
459 static void smaps_account(struct mem_size_stats *mss, struct page *page,
460 		bool compound, bool young, bool dirty)
461 {
462 	int i, nr = compound ? 1 << compound_order(page) : 1;
463 	unsigned long size = nr * PAGE_SIZE;
464 
465 	if (PageAnon(page))
466 		mss->anonymous += size;
467 
468 	mss->resident += size;
469 	/* Accumulate the size in pages that have been accessed. */
470 	if (young || page_is_young(page) || PageReferenced(page))
471 		mss->referenced += size;
472 
473 	/*
474 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
475 	 * If any subpage of the compound page mapped with PTE it would elevate
476 	 * page_count().
477 	 */
478 	if (page_count(page) == 1) {
479 		if (dirty || PageDirty(page))
480 			mss->private_dirty += size;
481 		else
482 			mss->private_clean += size;
483 		mss->pss += (u64)size << PSS_SHIFT;
484 		return;
485 	}
486 
487 	for (i = 0; i < nr; i++, page++) {
488 		int mapcount = page_mapcount(page);
489 
490 		if (mapcount >= 2) {
491 			if (dirty || PageDirty(page))
492 				mss->shared_dirty += PAGE_SIZE;
493 			else
494 				mss->shared_clean += PAGE_SIZE;
495 			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
496 		} else {
497 			if (dirty || PageDirty(page))
498 				mss->private_dirty += PAGE_SIZE;
499 			else
500 				mss->private_clean += PAGE_SIZE;
501 			mss->pss += PAGE_SIZE << PSS_SHIFT;
502 		}
503 	}
504 }
505 
506 #ifdef CONFIG_SHMEM
507 static int smaps_pte_hole(unsigned long addr, unsigned long end,
508 		struct mm_walk *walk)
509 {
510 	struct mem_size_stats *mss = walk->private;
511 
512 	mss->swap += shmem_partial_swap_usage(
513 			walk->vma->vm_file->f_mapping, addr, end);
514 
515 	return 0;
516 }
517 #endif
518 
519 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
520 		struct mm_walk *walk)
521 {
522 	struct mem_size_stats *mss = walk->private;
523 	struct vm_area_struct *vma = walk->vma;
524 	struct page *page = NULL;
525 
526 	if (pte_present(*pte)) {
527 		page = vm_normal_page(vma, addr, *pte);
528 	} else if (is_swap_pte(*pte)) {
529 		swp_entry_t swpent = pte_to_swp_entry(*pte);
530 
531 		if (!non_swap_entry(swpent)) {
532 			int mapcount;
533 
534 			mss->swap += PAGE_SIZE;
535 			mapcount = swp_swapcount(swpent);
536 			if (mapcount >= 2) {
537 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
538 
539 				do_div(pss_delta, mapcount);
540 				mss->swap_pss += pss_delta;
541 			} else {
542 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
543 			}
544 		} else if (is_migration_entry(swpent))
545 			page = migration_entry_to_page(swpent);
546 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
547 							&& pte_none(*pte))) {
548 		page = find_get_entry(vma->vm_file->f_mapping,
549 						linear_page_index(vma, addr));
550 		if (!page)
551 			return;
552 
553 		if (radix_tree_exceptional_entry(page))
554 			mss->swap += PAGE_SIZE;
555 		else
556 			put_page(page);
557 
558 		return;
559 	}
560 
561 	if (!page)
562 		return;
563 
564 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
565 }
566 
567 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
568 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
569 		struct mm_walk *walk)
570 {
571 	struct mem_size_stats *mss = walk->private;
572 	struct vm_area_struct *vma = walk->vma;
573 	struct page *page;
574 
575 	/* FOLL_DUMP will return -EFAULT on huge zero page */
576 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
577 	if (IS_ERR_OR_NULL(page))
578 		return;
579 	mss->anonymous_thp += HPAGE_PMD_SIZE;
580 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
581 }
582 #else
583 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
584 		struct mm_walk *walk)
585 {
586 }
587 #endif
588 
589 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
590 			   struct mm_walk *walk)
591 {
592 	struct vm_area_struct *vma = walk->vma;
593 	pte_t *pte;
594 	spinlock_t *ptl;
595 
596 	ptl = pmd_trans_huge_lock(pmd, vma);
597 	if (ptl) {
598 		smaps_pmd_entry(pmd, addr, walk);
599 		spin_unlock(ptl);
600 		return 0;
601 	}
602 
603 	if (pmd_trans_unstable(pmd))
604 		return 0;
605 	/*
606 	 * The mmap_sem held all the way back in m_start() is what
607 	 * keeps khugepaged out of here and from collapsing things
608 	 * in here.
609 	 */
610 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
611 	for (; addr != end; pte++, addr += PAGE_SIZE)
612 		smaps_pte_entry(pte, addr, walk);
613 	pte_unmap_unlock(pte - 1, ptl);
614 	cond_resched();
615 	return 0;
616 }
617 
618 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
619 {
620 	/*
621 	 * Don't forget to update Documentation/ on changes.
622 	 */
623 	static const char mnemonics[BITS_PER_LONG][2] = {
624 		/*
625 		 * In case if we meet a flag we don't know about.
626 		 */
627 		[0 ... (BITS_PER_LONG-1)] = "??",
628 
629 		[ilog2(VM_READ)]	= "rd",
630 		[ilog2(VM_WRITE)]	= "wr",
631 		[ilog2(VM_EXEC)]	= "ex",
632 		[ilog2(VM_SHARED)]	= "sh",
633 		[ilog2(VM_MAYREAD)]	= "mr",
634 		[ilog2(VM_MAYWRITE)]	= "mw",
635 		[ilog2(VM_MAYEXEC)]	= "me",
636 		[ilog2(VM_MAYSHARE)]	= "ms",
637 		[ilog2(VM_GROWSDOWN)]	= "gd",
638 		[ilog2(VM_PFNMAP)]	= "pf",
639 		[ilog2(VM_DENYWRITE)]	= "dw",
640 #ifdef CONFIG_X86_INTEL_MPX
641 		[ilog2(VM_MPX)]		= "mp",
642 #endif
643 		[ilog2(VM_LOCKED)]	= "lo",
644 		[ilog2(VM_IO)]		= "io",
645 		[ilog2(VM_SEQ_READ)]	= "sr",
646 		[ilog2(VM_RAND_READ)]	= "rr",
647 		[ilog2(VM_DONTCOPY)]	= "dc",
648 		[ilog2(VM_DONTEXPAND)]	= "de",
649 		[ilog2(VM_ACCOUNT)]	= "ac",
650 		[ilog2(VM_NORESERVE)]	= "nr",
651 		[ilog2(VM_HUGETLB)]	= "ht",
652 		[ilog2(VM_ARCH_1)]	= "ar",
653 		[ilog2(VM_DONTDUMP)]	= "dd",
654 #ifdef CONFIG_MEM_SOFT_DIRTY
655 		[ilog2(VM_SOFTDIRTY)]	= "sd",
656 #endif
657 		[ilog2(VM_MIXEDMAP)]	= "mm",
658 		[ilog2(VM_HUGEPAGE)]	= "hg",
659 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
660 		[ilog2(VM_MERGEABLE)]	= "mg",
661 		[ilog2(VM_UFFD_MISSING)]= "um",
662 		[ilog2(VM_UFFD_WP)]	= "uw",
663 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
664 		/* These come out via ProtectionKey: */
665 		[ilog2(VM_PKEY_BIT0)]	= "",
666 		[ilog2(VM_PKEY_BIT1)]	= "",
667 		[ilog2(VM_PKEY_BIT2)]	= "",
668 		[ilog2(VM_PKEY_BIT3)]	= "",
669 #endif
670 	};
671 	size_t i;
672 
673 	seq_puts(m, "VmFlags: ");
674 	for (i = 0; i < BITS_PER_LONG; i++) {
675 		if (!mnemonics[i][0])
676 			continue;
677 		if (vma->vm_flags & (1UL << i)) {
678 			seq_printf(m, "%c%c ",
679 				   mnemonics[i][0], mnemonics[i][1]);
680 		}
681 	}
682 	seq_putc(m, '\n');
683 }
684 
685 #ifdef CONFIG_HUGETLB_PAGE
686 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
687 				 unsigned long addr, unsigned long end,
688 				 struct mm_walk *walk)
689 {
690 	struct mem_size_stats *mss = walk->private;
691 	struct vm_area_struct *vma = walk->vma;
692 	struct page *page = NULL;
693 
694 	if (pte_present(*pte)) {
695 		page = vm_normal_page(vma, addr, *pte);
696 	} else if (is_swap_pte(*pte)) {
697 		swp_entry_t swpent = pte_to_swp_entry(*pte);
698 
699 		if (is_migration_entry(swpent))
700 			page = migration_entry_to_page(swpent);
701 	}
702 	if (page) {
703 		int mapcount = page_mapcount(page);
704 
705 		if (mapcount >= 2)
706 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
707 		else
708 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
709 	}
710 	return 0;
711 }
712 #endif /* HUGETLB_PAGE */
713 
714 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
715 {
716 }
717 
718 static int show_smap(struct seq_file *m, void *v, int is_pid)
719 {
720 	struct vm_area_struct *vma = v;
721 	struct mem_size_stats mss;
722 	struct mm_walk smaps_walk = {
723 		.pmd_entry = smaps_pte_range,
724 #ifdef CONFIG_HUGETLB_PAGE
725 		.hugetlb_entry = smaps_hugetlb_range,
726 #endif
727 		.mm = vma->vm_mm,
728 		.private = &mss,
729 	};
730 
731 	memset(&mss, 0, sizeof mss);
732 
733 #ifdef CONFIG_SHMEM
734 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
735 		/*
736 		 * For shared or readonly shmem mappings we know that all
737 		 * swapped out pages belong to the shmem object, and we can
738 		 * obtain the swap value much more efficiently. For private
739 		 * writable mappings, we might have COW pages that are
740 		 * not affected by the parent swapped out pages of the shmem
741 		 * object, so we have to distinguish them during the page walk.
742 		 * Unless we know that the shmem object (or the part mapped by
743 		 * our VMA) has no swapped out pages at all.
744 		 */
745 		unsigned long shmem_swapped = shmem_swap_usage(vma);
746 
747 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
748 					!(vma->vm_flags & VM_WRITE)) {
749 			mss.swap = shmem_swapped;
750 		} else {
751 			mss.check_shmem_swap = true;
752 			smaps_walk.pte_hole = smaps_pte_hole;
753 		}
754 	}
755 #endif
756 
757 	/* mmap_sem is held in m_start */
758 	walk_page_vma(vma, &smaps_walk);
759 
760 	show_map_vma(m, vma, is_pid);
761 
762 	seq_printf(m,
763 		   "Size:           %8lu kB\n"
764 		   "Rss:            %8lu kB\n"
765 		   "Pss:            %8lu kB\n"
766 		   "Shared_Clean:   %8lu kB\n"
767 		   "Shared_Dirty:   %8lu kB\n"
768 		   "Private_Clean:  %8lu kB\n"
769 		   "Private_Dirty:  %8lu kB\n"
770 		   "Referenced:     %8lu kB\n"
771 		   "Anonymous:      %8lu kB\n"
772 		   "AnonHugePages:  %8lu kB\n"
773 		   "Shared_Hugetlb: %8lu kB\n"
774 		   "Private_Hugetlb: %7lu kB\n"
775 		   "Swap:           %8lu kB\n"
776 		   "SwapPss:        %8lu kB\n"
777 		   "KernelPageSize: %8lu kB\n"
778 		   "MMUPageSize:    %8lu kB\n"
779 		   "Locked:         %8lu kB\n",
780 		   (vma->vm_end - vma->vm_start) >> 10,
781 		   mss.resident >> 10,
782 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
783 		   mss.shared_clean  >> 10,
784 		   mss.shared_dirty  >> 10,
785 		   mss.private_clean >> 10,
786 		   mss.private_dirty >> 10,
787 		   mss.referenced >> 10,
788 		   mss.anonymous >> 10,
789 		   mss.anonymous_thp >> 10,
790 		   mss.shared_hugetlb >> 10,
791 		   mss.private_hugetlb >> 10,
792 		   mss.swap >> 10,
793 		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
794 		   vma_kernel_pagesize(vma) >> 10,
795 		   vma_mmu_pagesize(vma) >> 10,
796 		   (vma->vm_flags & VM_LOCKED) ?
797 			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
798 
799 	arch_show_smap(m, vma);
800 	show_smap_vma_flags(m, vma);
801 	m_cache_vma(m, vma);
802 	return 0;
803 }
804 
805 static int show_pid_smap(struct seq_file *m, void *v)
806 {
807 	return show_smap(m, v, 1);
808 }
809 
810 static int show_tid_smap(struct seq_file *m, void *v)
811 {
812 	return show_smap(m, v, 0);
813 }
814 
815 static const struct seq_operations proc_pid_smaps_op = {
816 	.start	= m_start,
817 	.next	= m_next,
818 	.stop	= m_stop,
819 	.show	= show_pid_smap
820 };
821 
822 static const struct seq_operations proc_tid_smaps_op = {
823 	.start	= m_start,
824 	.next	= m_next,
825 	.stop	= m_stop,
826 	.show	= show_tid_smap
827 };
828 
829 static int pid_smaps_open(struct inode *inode, struct file *file)
830 {
831 	return do_maps_open(inode, file, &proc_pid_smaps_op);
832 }
833 
834 static int tid_smaps_open(struct inode *inode, struct file *file)
835 {
836 	return do_maps_open(inode, file, &proc_tid_smaps_op);
837 }
838 
839 const struct file_operations proc_pid_smaps_operations = {
840 	.open		= pid_smaps_open,
841 	.read		= seq_read,
842 	.llseek		= seq_lseek,
843 	.release	= proc_map_release,
844 };
845 
846 const struct file_operations proc_tid_smaps_operations = {
847 	.open		= tid_smaps_open,
848 	.read		= seq_read,
849 	.llseek		= seq_lseek,
850 	.release	= proc_map_release,
851 };
852 
853 enum clear_refs_types {
854 	CLEAR_REFS_ALL = 1,
855 	CLEAR_REFS_ANON,
856 	CLEAR_REFS_MAPPED,
857 	CLEAR_REFS_SOFT_DIRTY,
858 	CLEAR_REFS_MM_HIWATER_RSS,
859 	CLEAR_REFS_LAST,
860 };
861 
862 struct clear_refs_private {
863 	enum clear_refs_types type;
864 };
865 
866 #ifdef CONFIG_MEM_SOFT_DIRTY
867 static inline void clear_soft_dirty(struct vm_area_struct *vma,
868 		unsigned long addr, pte_t *pte)
869 {
870 	/*
871 	 * The soft-dirty tracker uses #PF-s to catch writes
872 	 * to pages, so write-protect the pte as well. See the
873 	 * Documentation/vm/soft-dirty.txt for full description
874 	 * of how soft-dirty works.
875 	 */
876 	pte_t ptent = *pte;
877 
878 	if (pte_present(ptent)) {
879 		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
880 		ptent = pte_wrprotect(ptent);
881 		ptent = pte_clear_soft_dirty(ptent);
882 		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
883 	} else if (is_swap_pte(ptent)) {
884 		ptent = pte_swp_clear_soft_dirty(ptent);
885 		set_pte_at(vma->vm_mm, addr, pte, ptent);
886 	}
887 }
888 #else
889 static inline void clear_soft_dirty(struct vm_area_struct *vma,
890 		unsigned long addr, pte_t *pte)
891 {
892 }
893 #endif
894 
895 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
896 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
897 		unsigned long addr, pmd_t *pmdp)
898 {
899 	pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
900 
901 	pmd = pmd_wrprotect(pmd);
902 	pmd = pmd_clear_soft_dirty(pmd);
903 
904 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
905 }
906 #else
907 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
908 		unsigned long addr, pmd_t *pmdp)
909 {
910 }
911 #endif
912 
913 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
914 				unsigned long end, struct mm_walk *walk)
915 {
916 	struct clear_refs_private *cp = walk->private;
917 	struct vm_area_struct *vma = walk->vma;
918 	pte_t *pte, ptent;
919 	spinlock_t *ptl;
920 	struct page *page;
921 
922 	ptl = pmd_trans_huge_lock(pmd, vma);
923 	if (ptl) {
924 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
925 			clear_soft_dirty_pmd(vma, addr, pmd);
926 			goto out;
927 		}
928 
929 		page = pmd_page(*pmd);
930 
931 		/* Clear accessed and referenced bits. */
932 		pmdp_test_and_clear_young(vma, addr, pmd);
933 		test_and_clear_page_young(page);
934 		ClearPageReferenced(page);
935 out:
936 		spin_unlock(ptl);
937 		return 0;
938 	}
939 
940 	if (pmd_trans_unstable(pmd))
941 		return 0;
942 
943 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
944 	for (; addr != end; pte++, addr += PAGE_SIZE) {
945 		ptent = *pte;
946 
947 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
948 			clear_soft_dirty(vma, addr, pte);
949 			continue;
950 		}
951 
952 		if (!pte_present(ptent))
953 			continue;
954 
955 		page = vm_normal_page(vma, addr, ptent);
956 		if (!page)
957 			continue;
958 
959 		/* Clear accessed and referenced bits. */
960 		ptep_test_and_clear_young(vma, addr, pte);
961 		test_and_clear_page_young(page);
962 		ClearPageReferenced(page);
963 	}
964 	pte_unmap_unlock(pte - 1, ptl);
965 	cond_resched();
966 	return 0;
967 }
968 
969 static int clear_refs_test_walk(unsigned long start, unsigned long end,
970 				struct mm_walk *walk)
971 {
972 	struct clear_refs_private *cp = walk->private;
973 	struct vm_area_struct *vma = walk->vma;
974 
975 	if (vma->vm_flags & VM_PFNMAP)
976 		return 1;
977 
978 	/*
979 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
980 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
981 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
982 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
983 	 */
984 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
985 		return 1;
986 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
987 		return 1;
988 	return 0;
989 }
990 
991 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
992 				size_t count, loff_t *ppos)
993 {
994 	struct task_struct *task;
995 	char buffer[PROC_NUMBUF];
996 	struct mm_struct *mm;
997 	struct vm_area_struct *vma;
998 	enum clear_refs_types type;
999 	int itype;
1000 	int rv;
1001 
1002 	memset(buffer, 0, sizeof(buffer));
1003 	if (count > sizeof(buffer) - 1)
1004 		count = sizeof(buffer) - 1;
1005 	if (copy_from_user(buffer, buf, count))
1006 		return -EFAULT;
1007 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1008 	if (rv < 0)
1009 		return rv;
1010 	type = (enum clear_refs_types)itype;
1011 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1012 		return -EINVAL;
1013 
1014 	task = get_proc_task(file_inode(file));
1015 	if (!task)
1016 		return -ESRCH;
1017 	mm = get_task_mm(task);
1018 	if (mm) {
1019 		struct clear_refs_private cp = {
1020 			.type = type,
1021 		};
1022 		struct mm_walk clear_refs_walk = {
1023 			.pmd_entry = clear_refs_pte_range,
1024 			.test_walk = clear_refs_test_walk,
1025 			.mm = mm,
1026 			.private = &cp,
1027 		};
1028 
1029 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1030 			if (down_write_killable(&mm->mmap_sem)) {
1031 				count = -EINTR;
1032 				goto out_mm;
1033 			}
1034 
1035 			/*
1036 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1037 			 * resident set size to this mm's current rss value.
1038 			 */
1039 			reset_mm_hiwater_rss(mm);
1040 			up_write(&mm->mmap_sem);
1041 			goto out_mm;
1042 		}
1043 
1044 		down_read(&mm->mmap_sem);
1045 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1046 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1047 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1048 					continue;
1049 				up_read(&mm->mmap_sem);
1050 				if (down_write_killable(&mm->mmap_sem)) {
1051 					count = -EINTR;
1052 					goto out_mm;
1053 				}
1054 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1055 					vma->vm_flags &= ~VM_SOFTDIRTY;
1056 					vma_set_page_prot(vma);
1057 				}
1058 				downgrade_write(&mm->mmap_sem);
1059 				break;
1060 			}
1061 			mmu_notifier_invalidate_range_start(mm, 0, -1);
1062 		}
1063 		walk_page_range(0, ~0UL, &clear_refs_walk);
1064 		if (type == CLEAR_REFS_SOFT_DIRTY)
1065 			mmu_notifier_invalidate_range_end(mm, 0, -1);
1066 		flush_tlb_mm(mm);
1067 		up_read(&mm->mmap_sem);
1068 out_mm:
1069 		mmput(mm);
1070 	}
1071 	put_task_struct(task);
1072 
1073 	return count;
1074 }
1075 
1076 const struct file_operations proc_clear_refs_operations = {
1077 	.write		= clear_refs_write,
1078 	.llseek		= noop_llseek,
1079 };
1080 
1081 typedef struct {
1082 	u64 pme;
1083 } pagemap_entry_t;
1084 
1085 struct pagemapread {
1086 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1087 	pagemap_entry_t *buffer;
1088 	bool show_pfn;
1089 };
1090 
1091 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1092 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1093 
1094 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1095 #define PM_PFRAME_BITS		55
1096 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1097 #define PM_SOFT_DIRTY		BIT_ULL(55)
1098 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1099 #define PM_FILE			BIT_ULL(61)
1100 #define PM_SWAP			BIT_ULL(62)
1101 #define PM_PRESENT		BIT_ULL(63)
1102 
1103 #define PM_END_OF_BUFFER    1
1104 
1105 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1106 {
1107 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1108 }
1109 
1110 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1111 			  struct pagemapread *pm)
1112 {
1113 	pm->buffer[pm->pos++] = *pme;
1114 	if (pm->pos >= pm->len)
1115 		return PM_END_OF_BUFFER;
1116 	return 0;
1117 }
1118 
1119 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1120 				struct mm_walk *walk)
1121 {
1122 	struct pagemapread *pm = walk->private;
1123 	unsigned long addr = start;
1124 	int err = 0;
1125 
1126 	while (addr < end) {
1127 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1128 		pagemap_entry_t pme = make_pme(0, 0);
1129 		/* End of address space hole, which we mark as non-present. */
1130 		unsigned long hole_end;
1131 
1132 		if (vma)
1133 			hole_end = min(end, vma->vm_start);
1134 		else
1135 			hole_end = end;
1136 
1137 		for (; addr < hole_end; addr += PAGE_SIZE) {
1138 			err = add_to_pagemap(addr, &pme, pm);
1139 			if (err)
1140 				goto out;
1141 		}
1142 
1143 		if (!vma)
1144 			break;
1145 
1146 		/* Addresses in the VMA. */
1147 		if (vma->vm_flags & VM_SOFTDIRTY)
1148 			pme = make_pme(0, PM_SOFT_DIRTY);
1149 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1150 			err = add_to_pagemap(addr, &pme, pm);
1151 			if (err)
1152 				goto out;
1153 		}
1154 	}
1155 out:
1156 	return err;
1157 }
1158 
1159 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1160 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1161 {
1162 	u64 frame = 0, flags = 0;
1163 	struct page *page = NULL;
1164 
1165 	if (pte_present(pte)) {
1166 		if (pm->show_pfn)
1167 			frame = pte_pfn(pte);
1168 		flags |= PM_PRESENT;
1169 		page = vm_normal_page(vma, addr, pte);
1170 		if (pte_soft_dirty(pte))
1171 			flags |= PM_SOFT_DIRTY;
1172 	} else if (is_swap_pte(pte)) {
1173 		swp_entry_t entry;
1174 		if (pte_swp_soft_dirty(pte))
1175 			flags |= PM_SOFT_DIRTY;
1176 		entry = pte_to_swp_entry(pte);
1177 		frame = swp_type(entry) |
1178 			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1179 		flags |= PM_SWAP;
1180 		if (is_migration_entry(entry))
1181 			page = migration_entry_to_page(entry);
1182 	}
1183 
1184 	if (page && !PageAnon(page))
1185 		flags |= PM_FILE;
1186 	if (page && page_mapcount(page) == 1)
1187 		flags |= PM_MMAP_EXCLUSIVE;
1188 	if (vma->vm_flags & VM_SOFTDIRTY)
1189 		flags |= PM_SOFT_DIRTY;
1190 
1191 	return make_pme(frame, flags);
1192 }
1193 
1194 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1195 			     struct mm_walk *walk)
1196 {
1197 	struct vm_area_struct *vma = walk->vma;
1198 	struct pagemapread *pm = walk->private;
1199 	spinlock_t *ptl;
1200 	pte_t *pte, *orig_pte;
1201 	int err = 0;
1202 
1203 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1204 	ptl = pmd_trans_huge_lock(pmdp, vma);
1205 	if (ptl) {
1206 		u64 flags = 0, frame = 0;
1207 		pmd_t pmd = *pmdp;
1208 
1209 		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1210 			flags |= PM_SOFT_DIRTY;
1211 
1212 		/*
1213 		 * Currently pmd for thp is always present because thp
1214 		 * can not be swapped-out, migrated, or HWPOISONed
1215 		 * (split in such cases instead.)
1216 		 * This if-check is just to prepare for future implementation.
1217 		 */
1218 		if (pmd_present(pmd)) {
1219 			struct page *page = pmd_page(pmd);
1220 
1221 			if (page_mapcount(page) == 1)
1222 				flags |= PM_MMAP_EXCLUSIVE;
1223 
1224 			flags |= PM_PRESENT;
1225 			if (pm->show_pfn)
1226 				frame = pmd_pfn(pmd) +
1227 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1228 		}
1229 
1230 		for (; addr != end; addr += PAGE_SIZE) {
1231 			pagemap_entry_t pme = make_pme(frame, flags);
1232 
1233 			err = add_to_pagemap(addr, &pme, pm);
1234 			if (err)
1235 				break;
1236 			if (pm->show_pfn && (flags & PM_PRESENT))
1237 				frame++;
1238 		}
1239 		spin_unlock(ptl);
1240 		return err;
1241 	}
1242 
1243 	if (pmd_trans_unstable(pmdp))
1244 		return 0;
1245 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1246 
1247 	/*
1248 	 * We can assume that @vma always points to a valid one and @end never
1249 	 * goes beyond vma->vm_end.
1250 	 */
1251 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1252 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1253 		pagemap_entry_t pme;
1254 
1255 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1256 		err = add_to_pagemap(addr, &pme, pm);
1257 		if (err)
1258 			break;
1259 	}
1260 	pte_unmap_unlock(orig_pte, ptl);
1261 
1262 	cond_resched();
1263 
1264 	return err;
1265 }
1266 
1267 #ifdef CONFIG_HUGETLB_PAGE
1268 /* This function walks within one hugetlb entry in the single call */
1269 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1270 				 unsigned long addr, unsigned long end,
1271 				 struct mm_walk *walk)
1272 {
1273 	struct pagemapread *pm = walk->private;
1274 	struct vm_area_struct *vma = walk->vma;
1275 	u64 flags = 0, frame = 0;
1276 	int err = 0;
1277 	pte_t pte;
1278 
1279 	if (vma->vm_flags & VM_SOFTDIRTY)
1280 		flags |= PM_SOFT_DIRTY;
1281 
1282 	pte = huge_ptep_get(ptep);
1283 	if (pte_present(pte)) {
1284 		struct page *page = pte_page(pte);
1285 
1286 		if (!PageAnon(page))
1287 			flags |= PM_FILE;
1288 
1289 		if (page_mapcount(page) == 1)
1290 			flags |= PM_MMAP_EXCLUSIVE;
1291 
1292 		flags |= PM_PRESENT;
1293 		if (pm->show_pfn)
1294 			frame = pte_pfn(pte) +
1295 				((addr & ~hmask) >> PAGE_SHIFT);
1296 	}
1297 
1298 	for (; addr != end; addr += PAGE_SIZE) {
1299 		pagemap_entry_t pme = make_pme(frame, flags);
1300 
1301 		err = add_to_pagemap(addr, &pme, pm);
1302 		if (err)
1303 			return err;
1304 		if (pm->show_pfn && (flags & PM_PRESENT))
1305 			frame++;
1306 	}
1307 
1308 	cond_resched();
1309 
1310 	return err;
1311 }
1312 #endif /* HUGETLB_PAGE */
1313 
1314 /*
1315  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1316  *
1317  * For each page in the address space, this file contains one 64-bit entry
1318  * consisting of the following:
1319  *
1320  * Bits 0-54  page frame number (PFN) if present
1321  * Bits 0-4   swap type if swapped
1322  * Bits 5-54  swap offset if swapped
1323  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1324  * Bit  56    page exclusively mapped
1325  * Bits 57-60 zero
1326  * Bit  61    page is file-page or shared-anon
1327  * Bit  62    page swapped
1328  * Bit  63    page present
1329  *
1330  * If the page is not present but in swap, then the PFN contains an
1331  * encoding of the swap file number and the page's offset into the
1332  * swap. Unmapped pages return a null PFN. This allows determining
1333  * precisely which pages are mapped (or in swap) and comparing mapped
1334  * pages between processes.
1335  *
1336  * Efficient users of this interface will use /proc/pid/maps to
1337  * determine which areas of memory are actually mapped and llseek to
1338  * skip over unmapped regions.
1339  */
1340 static ssize_t pagemap_read(struct file *file, char __user *buf,
1341 			    size_t count, loff_t *ppos)
1342 {
1343 	struct mm_struct *mm = file->private_data;
1344 	struct pagemapread pm;
1345 	struct mm_walk pagemap_walk = {};
1346 	unsigned long src;
1347 	unsigned long svpfn;
1348 	unsigned long start_vaddr;
1349 	unsigned long end_vaddr;
1350 	int ret = 0, copied = 0;
1351 
1352 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
1353 		goto out;
1354 
1355 	ret = -EINVAL;
1356 	/* file position must be aligned */
1357 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1358 		goto out_mm;
1359 
1360 	ret = 0;
1361 	if (!count)
1362 		goto out_mm;
1363 
1364 	/* do not disclose physical addresses: attack vector */
1365 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1366 
1367 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1368 	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1369 	ret = -ENOMEM;
1370 	if (!pm.buffer)
1371 		goto out_mm;
1372 
1373 	pagemap_walk.pmd_entry = pagemap_pmd_range;
1374 	pagemap_walk.pte_hole = pagemap_pte_hole;
1375 #ifdef CONFIG_HUGETLB_PAGE
1376 	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1377 #endif
1378 	pagemap_walk.mm = mm;
1379 	pagemap_walk.private = &pm;
1380 
1381 	src = *ppos;
1382 	svpfn = src / PM_ENTRY_BYTES;
1383 	start_vaddr = svpfn << PAGE_SHIFT;
1384 	end_vaddr = mm->task_size;
1385 
1386 	/* watch out for wraparound */
1387 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1388 		start_vaddr = end_vaddr;
1389 
1390 	/*
1391 	 * The odds are that this will stop walking way
1392 	 * before end_vaddr, because the length of the
1393 	 * user buffer is tracked in "pm", and the walk
1394 	 * will stop when we hit the end of the buffer.
1395 	 */
1396 	ret = 0;
1397 	while (count && (start_vaddr < end_vaddr)) {
1398 		int len;
1399 		unsigned long end;
1400 
1401 		pm.pos = 0;
1402 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1403 		/* overflow ? */
1404 		if (end < start_vaddr || end > end_vaddr)
1405 			end = end_vaddr;
1406 		down_read(&mm->mmap_sem);
1407 		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1408 		up_read(&mm->mmap_sem);
1409 		start_vaddr = end;
1410 
1411 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1412 		if (copy_to_user(buf, pm.buffer, len)) {
1413 			ret = -EFAULT;
1414 			goto out_free;
1415 		}
1416 		copied += len;
1417 		buf += len;
1418 		count -= len;
1419 	}
1420 	*ppos += copied;
1421 	if (!ret || ret == PM_END_OF_BUFFER)
1422 		ret = copied;
1423 
1424 out_free:
1425 	kfree(pm.buffer);
1426 out_mm:
1427 	mmput(mm);
1428 out:
1429 	return ret;
1430 }
1431 
1432 static int pagemap_open(struct inode *inode, struct file *file)
1433 {
1434 	struct mm_struct *mm;
1435 
1436 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1437 	if (IS_ERR(mm))
1438 		return PTR_ERR(mm);
1439 	file->private_data = mm;
1440 	return 0;
1441 }
1442 
1443 static int pagemap_release(struct inode *inode, struct file *file)
1444 {
1445 	struct mm_struct *mm = file->private_data;
1446 
1447 	if (mm)
1448 		mmdrop(mm);
1449 	return 0;
1450 }
1451 
1452 const struct file_operations proc_pagemap_operations = {
1453 	.llseek		= mem_lseek, /* borrow this */
1454 	.read		= pagemap_read,
1455 	.open		= pagemap_open,
1456 	.release	= pagemap_release,
1457 };
1458 #endif /* CONFIG_PROC_PAGE_MONITOR */
1459 
1460 #ifdef CONFIG_NUMA
1461 
1462 struct numa_maps {
1463 	unsigned long pages;
1464 	unsigned long anon;
1465 	unsigned long active;
1466 	unsigned long writeback;
1467 	unsigned long mapcount_max;
1468 	unsigned long dirty;
1469 	unsigned long swapcache;
1470 	unsigned long node[MAX_NUMNODES];
1471 };
1472 
1473 struct numa_maps_private {
1474 	struct proc_maps_private proc_maps;
1475 	struct numa_maps md;
1476 };
1477 
1478 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1479 			unsigned long nr_pages)
1480 {
1481 	int count = page_mapcount(page);
1482 
1483 	md->pages += nr_pages;
1484 	if (pte_dirty || PageDirty(page))
1485 		md->dirty += nr_pages;
1486 
1487 	if (PageSwapCache(page))
1488 		md->swapcache += nr_pages;
1489 
1490 	if (PageActive(page) || PageUnevictable(page))
1491 		md->active += nr_pages;
1492 
1493 	if (PageWriteback(page))
1494 		md->writeback += nr_pages;
1495 
1496 	if (PageAnon(page))
1497 		md->anon += nr_pages;
1498 
1499 	if (count > md->mapcount_max)
1500 		md->mapcount_max = count;
1501 
1502 	md->node[page_to_nid(page)] += nr_pages;
1503 }
1504 
1505 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1506 		unsigned long addr)
1507 {
1508 	struct page *page;
1509 	int nid;
1510 
1511 	if (!pte_present(pte))
1512 		return NULL;
1513 
1514 	page = vm_normal_page(vma, addr, pte);
1515 	if (!page)
1516 		return NULL;
1517 
1518 	if (PageReserved(page))
1519 		return NULL;
1520 
1521 	nid = page_to_nid(page);
1522 	if (!node_isset(nid, node_states[N_MEMORY]))
1523 		return NULL;
1524 
1525 	return page;
1526 }
1527 
1528 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1529 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1530 					      struct vm_area_struct *vma,
1531 					      unsigned long addr)
1532 {
1533 	struct page *page;
1534 	int nid;
1535 
1536 	if (!pmd_present(pmd))
1537 		return NULL;
1538 
1539 	page = vm_normal_page_pmd(vma, addr, pmd);
1540 	if (!page)
1541 		return NULL;
1542 
1543 	if (PageReserved(page))
1544 		return NULL;
1545 
1546 	nid = page_to_nid(page);
1547 	if (!node_isset(nid, node_states[N_MEMORY]))
1548 		return NULL;
1549 
1550 	return page;
1551 }
1552 #endif
1553 
1554 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1555 		unsigned long end, struct mm_walk *walk)
1556 {
1557 	struct numa_maps *md = walk->private;
1558 	struct vm_area_struct *vma = walk->vma;
1559 	spinlock_t *ptl;
1560 	pte_t *orig_pte;
1561 	pte_t *pte;
1562 
1563 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1564 	ptl = pmd_trans_huge_lock(pmd, vma);
1565 	if (ptl) {
1566 		struct page *page;
1567 
1568 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1569 		if (page)
1570 			gather_stats(page, md, pmd_dirty(*pmd),
1571 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1572 		spin_unlock(ptl);
1573 		return 0;
1574 	}
1575 
1576 	if (pmd_trans_unstable(pmd))
1577 		return 0;
1578 #endif
1579 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1580 	do {
1581 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1582 		if (!page)
1583 			continue;
1584 		gather_stats(page, md, pte_dirty(*pte), 1);
1585 
1586 	} while (pte++, addr += PAGE_SIZE, addr != end);
1587 	pte_unmap_unlock(orig_pte, ptl);
1588 	return 0;
1589 }
1590 #ifdef CONFIG_HUGETLB_PAGE
1591 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1592 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1593 {
1594 	pte_t huge_pte = huge_ptep_get(pte);
1595 	struct numa_maps *md;
1596 	struct page *page;
1597 
1598 	if (!pte_present(huge_pte))
1599 		return 0;
1600 
1601 	page = pte_page(huge_pte);
1602 	if (!page)
1603 		return 0;
1604 
1605 	md = walk->private;
1606 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1607 	return 0;
1608 }
1609 
1610 #else
1611 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1612 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1613 {
1614 	return 0;
1615 }
1616 #endif
1617 
1618 /*
1619  * Display pages allocated per node and memory policy via /proc.
1620  */
1621 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1622 {
1623 	struct numa_maps_private *numa_priv = m->private;
1624 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1625 	struct vm_area_struct *vma = v;
1626 	struct numa_maps *md = &numa_priv->md;
1627 	struct file *file = vma->vm_file;
1628 	struct mm_struct *mm = vma->vm_mm;
1629 	struct mm_walk walk = {
1630 		.hugetlb_entry = gather_hugetlb_stats,
1631 		.pmd_entry = gather_pte_stats,
1632 		.private = md,
1633 		.mm = mm,
1634 	};
1635 	struct mempolicy *pol;
1636 	char buffer[64];
1637 	int nid;
1638 
1639 	if (!mm)
1640 		return 0;
1641 
1642 	/* Ensure we start with an empty set of numa_maps statistics. */
1643 	memset(md, 0, sizeof(*md));
1644 
1645 	pol = __get_vma_policy(vma, vma->vm_start);
1646 	if (pol) {
1647 		mpol_to_str(buffer, sizeof(buffer), pol);
1648 		mpol_cond_put(pol);
1649 	} else {
1650 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1651 	}
1652 
1653 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1654 
1655 	if (file) {
1656 		seq_puts(m, " file=");
1657 		seq_file_path(m, file, "\n\t= ");
1658 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1659 		seq_puts(m, " heap");
1660 	} else if (is_stack(proc_priv, vma, is_pid)) {
1661 		seq_puts(m, " stack");
1662 	}
1663 
1664 	if (is_vm_hugetlb_page(vma))
1665 		seq_puts(m, " huge");
1666 
1667 	/* mmap_sem is held by m_start */
1668 	walk_page_vma(vma, &walk);
1669 
1670 	if (!md->pages)
1671 		goto out;
1672 
1673 	if (md->anon)
1674 		seq_printf(m, " anon=%lu", md->anon);
1675 
1676 	if (md->dirty)
1677 		seq_printf(m, " dirty=%lu", md->dirty);
1678 
1679 	if (md->pages != md->anon && md->pages != md->dirty)
1680 		seq_printf(m, " mapped=%lu", md->pages);
1681 
1682 	if (md->mapcount_max > 1)
1683 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1684 
1685 	if (md->swapcache)
1686 		seq_printf(m, " swapcache=%lu", md->swapcache);
1687 
1688 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1689 		seq_printf(m, " active=%lu", md->active);
1690 
1691 	if (md->writeback)
1692 		seq_printf(m, " writeback=%lu", md->writeback);
1693 
1694 	for_each_node_state(nid, N_MEMORY)
1695 		if (md->node[nid])
1696 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1697 
1698 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1699 out:
1700 	seq_putc(m, '\n');
1701 	m_cache_vma(m, vma);
1702 	return 0;
1703 }
1704 
1705 static int show_pid_numa_map(struct seq_file *m, void *v)
1706 {
1707 	return show_numa_map(m, v, 1);
1708 }
1709 
1710 static int show_tid_numa_map(struct seq_file *m, void *v)
1711 {
1712 	return show_numa_map(m, v, 0);
1713 }
1714 
1715 static const struct seq_operations proc_pid_numa_maps_op = {
1716 	.start  = m_start,
1717 	.next   = m_next,
1718 	.stop   = m_stop,
1719 	.show   = show_pid_numa_map,
1720 };
1721 
1722 static const struct seq_operations proc_tid_numa_maps_op = {
1723 	.start  = m_start,
1724 	.next   = m_next,
1725 	.stop   = m_stop,
1726 	.show   = show_tid_numa_map,
1727 };
1728 
1729 static int numa_maps_open(struct inode *inode, struct file *file,
1730 			  const struct seq_operations *ops)
1731 {
1732 	return proc_maps_open(inode, file, ops,
1733 				sizeof(struct numa_maps_private));
1734 }
1735 
1736 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1737 {
1738 	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1739 }
1740 
1741 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1742 {
1743 	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1744 }
1745 
1746 const struct file_operations proc_pid_numa_maps_operations = {
1747 	.open		= pid_numa_maps_open,
1748 	.read		= seq_read,
1749 	.llseek		= seq_lseek,
1750 	.release	= proc_map_release,
1751 };
1752 
1753 const struct file_operations proc_tid_numa_maps_operations = {
1754 	.open		= tid_numa_maps_open,
1755 	.read		= seq_read,
1756 	.llseek		= seq_lseek,
1757 	.release	= proc_map_release,
1758 };
1759 #endif /* CONFIG_NUMA */
1760