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1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/pagewalk.h>
3 #include <linux/vmacache.h>
4 #include <linux/hugetlb.h>
5 #include <linux/huge_mm.h>
6 #include <linux/mount.h>
7 #include <linux/seq_file.h>
8 #include <linux/highmem.h>
9 #include <linux/ptrace.h>
10 #include <linux/slab.h>
11 #include <linux/pagemap.h>
12 #include <linux/mempolicy.h>
13 #include <linux/rmap.h>
14 #include <linux/swap.h>
15 #include <linux/sched/mm.h>
16 #include <linux/swapops.h>
17 #include <linux/mmu_notifier.h>
18 #include <linux/page_idle.h>
19 #include <linux/shmem_fs.h>
20 #include <linux/uaccess.h>
21 #include <linux/pkeys.h>
22 
23 #include <asm/elf.h>
24 #include <asm/tlb.h>
25 #include <asm/tlbflush.h>
26 #include "internal.h"
27 
28 #define SEQ_PUT_DEC(str, val) \
29 		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
task_mem(struct seq_file * m,struct mm_struct * mm)30 void task_mem(struct seq_file *m, struct mm_struct *mm)
31 {
32 	unsigned long text, lib, swap, anon, file, shmem;
33 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
34 
35 	anon = get_mm_counter(mm, MM_ANONPAGES);
36 	file = get_mm_counter(mm, MM_FILEPAGES);
37 	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
38 
39 	/*
40 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
41 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
42 	 * collector of these hiwater stats must therefore get total_vm
43 	 * and rss too, which will usually be the higher.  Barriers? not
44 	 * worth the effort, such snapshots can always be inconsistent.
45 	 */
46 	hiwater_vm = total_vm = mm->total_vm;
47 	if (hiwater_vm < mm->hiwater_vm)
48 		hiwater_vm = mm->hiwater_vm;
49 	hiwater_rss = total_rss = anon + file + shmem;
50 	if (hiwater_rss < mm->hiwater_rss)
51 		hiwater_rss = mm->hiwater_rss;
52 
53 	/* split executable areas between text and lib */
54 	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
55 	text = min(text, mm->exec_vm << PAGE_SHIFT);
56 	lib = (mm->exec_vm << PAGE_SHIFT) - text;
57 
58 	swap = get_mm_counter(mm, MM_SWAPENTS);
59 	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
60 	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
61 	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
62 	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
63 	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
64 	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
65 	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
66 	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
67 	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
68 	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
69 	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
70 	seq_put_decimal_ull_width(m,
71 		    " kB\nVmExe:\t", text >> 10, 8);
72 	seq_put_decimal_ull_width(m,
73 		    " kB\nVmLib:\t", lib >> 10, 8);
74 	seq_put_decimal_ull_width(m,
75 		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
76 	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
77 	seq_puts(m, " kB\n");
78 	hugetlb_report_usage(m, mm);
79 }
80 #undef SEQ_PUT_DEC
81 
task_vsize(struct mm_struct * mm)82 unsigned long task_vsize(struct mm_struct *mm)
83 {
84 	return PAGE_SIZE * mm->total_vm;
85 }
86 
task_statm(struct mm_struct * mm,unsigned long * shared,unsigned long * text,unsigned long * data,unsigned long * resident)87 unsigned long task_statm(struct mm_struct *mm,
88 			 unsigned long *shared, unsigned long *text,
89 			 unsigned long *data, unsigned long *resident)
90 {
91 	*shared = get_mm_counter(mm, MM_FILEPAGES) +
92 			get_mm_counter(mm, MM_SHMEMPAGES);
93 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
94 								>> PAGE_SHIFT;
95 	*data = mm->data_vm + mm->stack_vm;
96 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
97 	return mm->total_vm;
98 }
99 
100 #ifdef CONFIG_NUMA
101 /*
102  * Save get_task_policy() for show_numa_map().
103  */
hold_task_mempolicy(struct proc_maps_private * priv)104 static void hold_task_mempolicy(struct proc_maps_private *priv)
105 {
106 	struct task_struct *task = priv->task;
107 
108 	task_lock(task);
109 	priv->task_mempolicy = get_task_policy(task);
110 	mpol_get(priv->task_mempolicy);
111 	task_unlock(task);
112 }
release_task_mempolicy(struct proc_maps_private * priv)113 static void release_task_mempolicy(struct proc_maps_private *priv)
114 {
115 	mpol_put(priv->task_mempolicy);
116 }
117 #else
hold_task_mempolicy(struct proc_maps_private * priv)118 static void hold_task_mempolicy(struct proc_maps_private *priv)
119 {
120 }
release_task_mempolicy(struct proc_maps_private * priv)121 static void release_task_mempolicy(struct proc_maps_private *priv)
122 {
123 }
124 #endif
125 
seq_print_vma_name(struct seq_file * m,struct vm_area_struct * vma)126 static void seq_print_vma_name(struct seq_file *m, struct vm_area_struct *vma)
127 {
128 	const char __user *name = vma_get_anon_name(vma);
129 	struct mm_struct *mm = vma->vm_mm;
130 
131 	unsigned long page_start_vaddr;
132 	unsigned long page_offset;
133 	unsigned long num_pages;
134 	unsigned long max_len = NAME_MAX;
135 	int i;
136 
137 	page_start_vaddr = (unsigned long)name & PAGE_MASK;
138 	page_offset = (unsigned long)name - page_start_vaddr;
139 	num_pages = DIV_ROUND_UP(page_offset + max_len, PAGE_SIZE);
140 
141 	seq_puts(m, "[anon:");
142 
143 	for (i = 0; i < num_pages; i++) {
144 		int len;
145 		int write_len;
146 		const char *kaddr;
147 		long pages_pinned;
148 		struct page *page;
149 
150 		pages_pinned = get_user_pages_remote(current, mm,
151 				page_start_vaddr, 1, 0, &page, NULL, NULL);
152 		if (pages_pinned < 1) {
153 			seq_puts(m, "<fault>]");
154 			return;
155 		}
156 
157 		kaddr = (const char *)kmap(page);
158 		len = min(max_len, PAGE_SIZE - page_offset);
159 		write_len = strnlen(kaddr + page_offset, len);
160 		seq_write(m, kaddr + page_offset, write_len);
161 		kunmap(page);
162 		put_page(page);
163 
164 		/* if strnlen hit a null terminator then we're done */
165 		if (write_len != len)
166 			break;
167 
168 		max_len -= len;
169 		page_offset = 0;
170 		page_start_vaddr += PAGE_SIZE;
171 	}
172 
173 	seq_putc(m, ']');
174 }
175 
vma_stop(struct proc_maps_private * priv)176 static void vma_stop(struct proc_maps_private *priv)
177 {
178 	struct mm_struct *mm = priv->mm;
179 
180 	release_task_mempolicy(priv);
181 	up_read(&mm->mmap_sem);
182 	mmput(mm);
183 }
184 
185 static struct vm_area_struct *
m_next_vma(struct proc_maps_private * priv,struct vm_area_struct * vma)186 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
187 {
188 	if (vma == priv->tail_vma)
189 		return NULL;
190 	return vma->vm_next ?: priv->tail_vma;
191 }
192 
m_cache_vma(struct seq_file * m,struct vm_area_struct * vma)193 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
194 {
195 	if (m->count < m->size)	/* vma is copied successfully */
196 		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
197 }
198 
m_start(struct seq_file * m,loff_t * ppos)199 static void *m_start(struct seq_file *m, loff_t *ppos)
200 {
201 	struct proc_maps_private *priv = m->private;
202 	unsigned long last_addr = m->version;
203 	struct mm_struct *mm;
204 	struct vm_area_struct *vma;
205 	unsigned int pos = *ppos;
206 
207 	/* See m_cache_vma(). Zero at the start or after lseek. */
208 	if (last_addr == -1UL)
209 		return NULL;
210 
211 	priv->task = get_proc_task(priv->inode);
212 	if (!priv->task)
213 		return ERR_PTR(-ESRCH);
214 
215 	mm = priv->mm;
216 	if (!mm || !mmget_not_zero(mm))
217 		return NULL;
218 
219 	if (down_read_killable(&mm->mmap_sem)) {
220 		mmput(mm);
221 		return ERR_PTR(-EINTR);
222 	}
223 
224 	hold_task_mempolicy(priv);
225 	priv->tail_vma = get_gate_vma(mm);
226 
227 	if (last_addr) {
228 		vma = find_vma(mm, last_addr - 1);
229 		if (vma && vma->vm_start <= last_addr)
230 			vma = m_next_vma(priv, vma);
231 		if (vma)
232 			return vma;
233 	}
234 
235 	m->version = 0;
236 	if (pos < mm->map_count) {
237 		for (vma = mm->mmap; pos; pos--) {
238 			m->version = vma->vm_start;
239 			vma = vma->vm_next;
240 		}
241 		return vma;
242 	}
243 
244 	/* we do not bother to update m->version in this case */
245 	if (pos == mm->map_count && priv->tail_vma)
246 		return priv->tail_vma;
247 
248 	vma_stop(priv);
249 	return NULL;
250 }
251 
m_next(struct seq_file * m,void * v,loff_t * pos)252 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
253 {
254 	struct proc_maps_private *priv = m->private;
255 	struct vm_area_struct *next;
256 
257 	(*pos)++;
258 	next = m_next_vma(priv, v);
259 	if (!next)
260 		vma_stop(priv);
261 	return next;
262 }
263 
m_stop(struct seq_file * m,void * v)264 static void m_stop(struct seq_file *m, void *v)
265 {
266 	struct proc_maps_private *priv = m->private;
267 
268 	if (!IS_ERR_OR_NULL(v))
269 		vma_stop(priv);
270 	if (priv->task) {
271 		put_task_struct(priv->task);
272 		priv->task = NULL;
273 	}
274 }
275 
proc_maps_open(struct inode * inode,struct file * file,const struct seq_operations * ops,int psize)276 static int proc_maps_open(struct inode *inode, struct file *file,
277 			const struct seq_operations *ops, int psize)
278 {
279 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
280 
281 	if (!priv)
282 		return -ENOMEM;
283 
284 	priv->inode = inode;
285 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
286 	if (IS_ERR(priv->mm)) {
287 		int err = PTR_ERR(priv->mm);
288 
289 		seq_release_private(inode, file);
290 		return err;
291 	}
292 
293 	return 0;
294 }
295 
proc_map_release(struct inode * inode,struct file * file)296 static int proc_map_release(struct inode *inode, struct file *file)
297 {
298 	struct seq_file *seq = file->private_data;
299 	struct proc_maps_private *priv = seq->private;
300 
301 	if (priv->mm)
302 		mmdrop(priv->mm);
303 
304 	return seq_release_private(inode, file);
305 }
306 
do_maps_open(struct inode * inode,struct file * file,const struct seq_operations * ops)307 static int do_maps_open(struct inode *inode, struct file *file,
308 			const struct seq_operations *ops)
309 {
310 	return proc_maps_open(inode, file, ops,
311 				sizeof(struct proc_maps_private));
312 }
313 
314 /*
315  * Indicate if the VMA is a stack for the given task; for
316  * /proc/PID/maps that is the stack of the main task.
317  */
is_stack(struct vm_area_struct * vma)318 static int is_stack(struct vm_area_struct *vma)
319 {
320 	/*
321 	 * We make no effort to guess what a given thread considers to be
322 	 * its "stack".  It's not even well-defined for programs written
323 	 * languages like Go.
324 	 */
325 	return vma->vm_start <= vma->vm_mm->start_stack &&
326 		vma->vm_end >= vma->vm_mm->start_stack;
327 }
328 
show_vma_header_prefix(struct seq_file * m,unsigned long start,unsigned long end,vm_flags_t flags,unsigned long long pgoff,dev_t dev,unsigned long ino)329 static void show_vma_header_prefix(struct seq_file *m,
330 				   unsigned long start, unsigned long end,
331 				   vm_flags_t flags, unsigned long long pgoff,
332 				   dev_t dev, unsigned long ino)
333 {
334 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
335 	seq_put_hex_ll(m, NULL, start, 8);
336 	seq_put_hex_ll(m, "-", end, 8);
337 	seq_putc(m, ' ');
338 	seq_putc(m, flags & VM_READ ? 'r' : '-');
339 	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
340 	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
341 	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
342 	seq_put_hex_ll(m, " ", pgoff, 8);
343 	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
344 	seq_put_hex_ll(m, ":", MINOR(dev), 2);
345 	seq_put_decimal_ull(m, " ", ino);
346 	seq_putc(m, ' ');
347 }
348 
349 static void
show_map_vma(struct seq_file * m,struct vm_area_struct * vma)350 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
351 {
352 	struct mm_struct *mm = vma->vm_mm;
353 	struct file *file = vma->vm_file;
354 	vm_flags_t flags = vma->vm_flags;
355 	unsigned long ino = 0;
356 	unsigned long long pgoff = 0;
357 	unsigned long start, end;
358 	dev_t dev = 0;
359 	const char *name = NULL;
360 
361 	if (file) {
362 		struct inode *inode = file_inode(vma->vm_file);
363 		dev = inode->i_sb->s_dev;
364 		ino = inode->i_ino;
365 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
366 	}
367 
368 	start = vma->vm_start;
369 	end = vma->vm_end;
370 	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
371 
372 	/*
373 	 * Print the dentry name for named mappings, and a
374 	 * special [heap] marker for the heap:
375 	 */
376 	if (file) {
377 		seq_pad(m, ' ');
378 		seq_file_path(m, file, "\n");
379 		goto done;
380 	}
381 
382 	if (vma->vm_ops && vma->vm_ops->name) {
383 		name = vma->vm_ops->name(vma);
384 		if (name)
385 			goto done;
386 	}
387 
388 	name = arch_vma_name(vma);
389 	if (!name) {
390 		if (!mm) {
391 			name = "[vdso]";
392 			goto done;
393 		}
394 
395 		if (vma->vm_start <= mm->brk &&
396 		    vma->vm_end >= mm->start_brk) {
397 			name = "[heap]";
398 			goto done;
399 		}
400 
401 		if (is_stack(vma)) {
402 			name = "[stack]";
403 			goto done;
404 		}
405 
406 		if (vma_get_anon_name(vma)) {
407 			seq_pad(m, ' ');
408 			seq_print_vma_name(m, vma);
409 		}
410 	}
411 
412 done:
413 	if (name) {
414 		seq_pad(m, ' ');
415 		seq_puts(m, name);
416 	}
417 	seq_putc(m, '\n');
418 }
419 
show_map(struct seq_file * m,void * v)420 static int show_map(struct seq_file *m, void *v)
421 {
422 	show_map_vma(m, v);
423 	m_cache_vma(m, v);
424 	return 0;
425 }
426 
427 static const struct seq_operations proc_pid_maps_op = {
428 	.start	= m_start,
429 	.next	= m_next,
430 	.stop	= m_stop,
431 	.show	= show_map
432 };
433 
pid_maps_open(struct inode * inode,struct file * file)434 static int pid_maps_open(struct inode *inode, struct file *file)
435 {
436 	return do_maps_open(inode, file, &proc_pid_maps_op);
437 }
438 
439 const struct file_operations proc_pid_maps_operations = {
440 	.open		= pid_maps_open,
441 	.read		= seq_read,
442 	.llseek		= seq_lseek,
443 	.release	= proc_map_release,
444 };
445 
446 /*
447  * Proportional Set Size(PSS): my share of RSS.
448  *
449  * PSS of a process is the count of pages it has in memory, where each
450  * page is divided by the number of processes sharing it.  So if a
451  * process has 1000 pages all to itself, and 1000 shared with one other
452  * process, its PSS will be 1500.
453  *
454  * To keep (accumulated) division errors low, we adopt a 64bit
455  * fixed-point pss counter to minimize division errors. So (pss >>
456  * PSS_SHIFT) would be the real byte count.
457  *
458  * A shift of 12 before division means (assuming 4K page size):
459  * 	- 1M 3-user-pages add up to 8KB errors;
460  * 	- supports mapcount up to 2^24, or 16M;
461  * 	- supports PSS up to 2^52 bytes, or 4PB.
462  */
463 #define PSS_SHIFT 12
464 
465 #ifdef CONFIG_PROC_PAGE_MONITOR
466 struct mem_size_stats {
467 	unsigned long resident;
468 	unsigned long shared_clean;
469 	unsigned long shared_dirty;
470 	unsigned long private_clean;
471 	unsigned long private_dirty;
472 	unsigned long referenced;
473 	unsigned long anonymous;
474 	unsigned long lazyfree;
475 	unsigned long anonymous_thp;
476 	unsigned long shmem_thp;
477 	unsigned long file_thp;
478 	unsigned long swap;
479 	unsigned long shared_hugetlb;
480 	unsigned long private_hugetlb;
481 	u64 pss;
482 	u64 pss_anon;
483 	u64 pss_file;
484 	u64 pss_shmem;
485 	u64 pss_locked;
486 	u64 swap_pss;
487 	bool check_shmem_swap;
488 };
489 
smaps_page_accumulate(struct mem_size_stats * mss,struct page * page,unsigned long size,unsigned long pss,bool dirty,bool locked,bool private)490 static void smaps_page_accumulate(struct mem_size_stats *mss,
491 		struct page *page, unsigned long size, unsigned long pss,
492 		bool dirty, bool locked, bool private)
493 {
494 	mss->pss += pss;
495 
496 	if (PageAnon(page))
497 		mss->pss_anon += pss;
498 	else if (PageSwapBacked(page))
499 		mss->pss_shmem += pss;
500 	else
501 		mss->pss_file += pss;
502 
503 	if (locked)
504 		mss->pss_locked += pss;
505 
506 	if (dirty || PageDirty(page)) {
507 		if (private)
508 			mss->private_dirty += size;
509 		else
510 			mss->shared_dirty += size;
511 	} else {
512 		if (private)
513 			mss->private_clean += size;
514 		else
515 			mss->shared_clean += size;
516 	}
517 }
518 
smaps_account(struct mem_size_stats * mss,struct page * page,bool compound,bool young,bool dirty,bool locked)519 static void smaps_account(struct mem_size_stats *mss, struct page *page,
520 		bool compound, bool young, bool dirty, bool locked)
521 {
522 	int i, nr = compound ? compound_nr(page) : 1;
523 	unsigned long size = nr * PAGE_SIZE;
524 
525 	/*
526 	 * First accumulate quantities that depend only on |size| and the type
527 	 * of the compound page.
528 	 */
529 	if (PageAnon(page)) {
530 		mss->anonymous += size;
531 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
532 			mss->lazyfree += size;
533 	}
534 
535 	mss->resident += size;
536 	/* Accumulate the size in pages that have been accessed. */
537 	if (young || page_is_young(page) || PageReferenced(page))
538 		mss->referenced += size;
539 
540 	/*
541 	 * Then accumulate quantities that may depend on sharing, or that may
542 	 * differ page-by-page.
543 	 *
544 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
545 	 * If any subpage of the compound page mapped with PTE it would elevate
546 	 * page_count().
547 	 */
548 	if (page_count(page) == 1) {
549 		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
550 			locked, true);
551 		return;
552 	}
553 	for (i = 0; i < nr; i++, page++) {
554 		int mapcount = page_mapcount(page);
555 		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
556 		if (mapcount >= 2)
557 			pss /= mapcount;
558 		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
559 				      mapcount < 2);
560 	}
561 }
562 
563 #ifdef CONFIG_SHMEM
smaps_pte_hole(unsigned long addr,unsigned long end,struct mm_walk * walk)564 static int smaps_pte_hole(unsigned long addr, unsigned long end,
565 		struct mm_walk *walk)
566 {
567 	struct mem_size_stats *mss = walk->private;
568 
569 	mss->swap += shmem_partial_swap_usage(
570 			walk->vma->vm_file->f_mapping, addr, end);
571 
572 	return 0;
573 }
574 #else
575 #define smaps_pte_hole		NULL
576 #endif /* CONFIG_SHMEM */
577 
smaps_pte_entry(pte_t * pte,unsigned long addr,struct mm_walk * walk)578 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
579 		struct mm_walk *walk)
580 {
581 	struct mem_size_stats *mss = walk->private;
582 	struct vm_area_struct *vma = walk->vma;
583 	bool locked = !!(vma->vm_flags & VM_LOCKED);
584 	struct page *page = NULL;
585 
586 	if (pte_present(*pte)) {
587 		page = vm_normal_page(vma, addr, *pte);
588 	} else if (is_swap_pte(*pte)) {
589 		swp_entry_t swpent = pte_to_swp_entry(*pte);
590 
591 		if (!non_swap_entry(swpent)) {
592 			int mapcount;
593 
594 			mss->swap += PAGE_SIZE;
595 			mapcount = swp_swapcount(swpent);
596 			if (mapcount >= 2) {
597 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
598 
599 				do_div(pss_delta, mapcount);
600 				mss->swap_pss += pss_delta;
601 			} else {
602 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
603 			}
604 		} else if (is_migration_entry(swpent))
605 			page = migration_entry_to_page(swpent);
606 		else if (is_device_private_entry(swpent))
607 			page = device_private_entry_to_page(swpent);
608 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
609 							&& pte_none(*pte))) {
610 		page = find_get_entry(vma->vm_file->f_mapping,
611 						linear_page_index(vma, addr));
612 		if (!page)
613 			return;
614 
615 		if (xa_is_value(page))
616 			mss->swap += PAGE_SIZE;
617 		else
618 			put_page(page);
619 
620 		return;
621 	}
622 
623 	if (!page)
624 		return;
625 
626 	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
627 }
628 
629 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
smaps_pmd_entry(pmd_t * pmd,unsigned long addr,struct mm_walk * walk)630 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
631 		struct mm_walk *walk)
632 {
633 	struct mem_size_stats *mss = walk->private;
634 	struct vm_area_struct *vma = walk->vma;
635 	bool locked = !!(vma->vm_flags & VM_LOCKED);
636 	struct page *page;
637 
638 	/* FOLL_DUMP will return -EFAULT on huge zero page */
639 	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
640 	if (IS_ERR_OR_NULL(page))
641 		return;
642 	if (PageAnon(page))
643 		mss->anonymous_thp += HPAGE_PMD_SIZE;
644 	else if (PageSwapBacked(page))
645 		mss->shmem_thp += HPAGE_PMD_SIZE;
646 	else if (is_zone_device_page(page))
647 		/* pass */;
648 	else
649 		mss->file_thp += HPAGE_PMD_SIZE;
650 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
651 }
652 #else
smaps_pmd_entry(pmd_t * pmd,unsigned long addr,struct mm_walk * walk)653 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
654 		struct mm_walk *walk)
655 {
656 }
657 #endif
658 
smaps_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)659 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
660 			   struct mm_walk *walk)
661 {
662 	struct vm_area_struct *vma = walk->vma;
663 	pte_t *pte;
664 	spinlock_t *ptl;
665 
666 	ptl = pmd_trans_huge_lock(pmd, vma);
667 	if (ptl) {
668 		if (pmd_present(*pmd))
669 			smaps_pmd_entry(pmd, addr, walk);
670 		spin_unlock(ptl);
671 		goto out;
672 	}
673 
674 	if (pmd_trans_unstable(pmd))
675 		goto out;
676 	/*
677 	 * The mmap_sem held all the way back in m_start() is what
678 	 * keeps khugepaged out of here and from collapsing things
679 	 * in here.
680 	 */
681 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
682 	for (; addr != end; pte++, addr += PAGE_SIZE)
683 		smaps_pte_entry(pte, addr, walk);
684 	pte_unmap_unlock(pte - 1, ptl);
685 out:
686 	cond_resched();
687 	return 0;
688 }
689 
show_smap_vma_flags(struct seq_file * m,struct vm_area_struct * vma)690 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
691 {
692 	/*
693 	 * Don't forget to update Documentation/ on changes.
694 	 */
695 	static const char mnemonics[BITS_PER_LONG][2] = {
696 		/*
697 		 * In case if we meet a flag we don't know about.
698 		 */
699 		[0 ... (BITS_PER_LONG-1)] = "??",
700 
701 		[ilog2(VM_READ)]	= "rd",
702 		[ilog2(VM_WRITE)]	= "wr",
703 		[ilog2(VM_EXEC)]	= "ex",
704 		[ilog2(VM_SHARED)]	= "sh",
705 		[ilog2(VM_MAYREAD)]	= "mr",
706 		[ilog2(VM_MAYWRITE)]	= "mw",
707 		[ilog2(VM_MAYEXEC)]	= "me",
708 		[ilog2(VM_MAYSHARE)]	= "ms",
709 		[ilog2(VM_GROWSDOWN)]	= "gd",
710 		[ilog2(VM_PFNMAP)]	= "pf",
711 		[ilog2(VM_DENYWRITE)]	= "dw",
712 #ifdef CONFIG_X86_INTEL_MPX
713 		[ilog2(VM_MPX)]		= "mp",
714 #endif
715 		[ilog2(VM_LOCKED)]	= "lo",
716 		[ilog2(VM_IO)]		= "io",
717 		[ilog2(VM_SEQ_READ)]	= "sr",
718 		[ilog2(VM_RAND_READ)]	= "rr",
719 		[ilog2(VM_DONTCOPY)]	= "dc",
720 		[ilog2(VM_DONTEXPAND)]	= "de",
721 		[ilog2(VM_ACCOUNT)]	= "ac",
722 		[ilog2(VM_NORESERVE)]	= "nr",
723 		[ilog2(VM_HUGETLB)]	= "ht",
724 		[ilog2(VM_SYNC)]	= "sf",
725 		[ilog2(VM_ARCH_1)]	= "ar",
726 		[ilog2(VM_WIPEONFORK)]	= "wf",
727 		[ilog2(VM_DONTDUMP)]	= "dd",
728 #ifdef CONFIG_MEM_SOFT_DIRTY
729 		[ilog2(VM_SOFTDIRTY)]	= "sd",
730 #endif
731 		[ilog2(VM_MIXEDMAP)]	= "mm",
732 		[ilog2(VM_HUGEPAGE)]	= "hg",
733 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
734 		[ilog2(VM_MERGEABLE)]	= "mg",
735 		[ilog2(VM_UFFD_MISSING)]= "um",
736 		[ilog2(VM_UFFD_WP)]	= "uw",
737 #ifdef CONFIG_ARCH_HAS_PKEYS
738 		/* These come out via ProtectionKey: */
739 		[ilog2(VM_PKEY_BIT0)]	= "",
740 		[ilog2(VM_PKEY_BIT1)]	= "",
741 		[ilog2(VM_PKEY_BIT2)]	= "",
742 		[ilog2(VM_PKEY_BIT3)]	= "",
743 #if VM_PKEY_BIT4
744 		[ilog2(VM_PKEY_BIT4)]	= "",
745 #endif
746 #endif /* CONFIG_ARCH_HAS_PKEYS */
747 	};
748 	size_t i;
749 
750 	seq_puts(m, "VmFlags: ");
751 	for (i = 0; i < BITS_PER_LONG; i++) {
752 		if (!mnemonics[i][0])
753 			continue;
754 		if (vma->vm_flags & (1UL << i)) {
755 			seq_putc(m, mnemonics[i][0]);
756 			seq_putc(m, mnemonics[i][1]);
757 			seq_putc(m, ' ');
758 		}
759 	}
760 	seq_putc(m, '\n');
761 }
762 
763 #ifdef CONFIG_HUGETLB_PAGE
smaps_hugetlb_range(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)764 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
765 				 unsigned long addr, unsigned long end,
766 				 struct mm_walk *walk)
767 {
768 	struct mem_size_stats *mss = walk->private;
769 	struct vm_area_struct *vma = walk->vma;
770 	struct page *page = NULL;
771 
772 	if (pte_present(*pte)) {
773 		page = vm_normal_page(vma, addr, *pte);
774 	} else if (is_swap_pte(*pte)) {
775 		swp_entry_t swpent = pte_to_swp_entry(*pte);
776 
777 		if (is_migration_entry(swpent))
778 			page = migration_entry_to_page(swpent);
779 		else if (is_device_private_entry(swpent))
780 			page = device_private_entry_to_page(swpent);
781 	}
782 	if (page) {
783 		int mapcount = page_mapcount(page);
784 
785 		if (mapcount >= 2)
786 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
787 		else
788 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
789 	}
790 	return 0;
791 }
792 #else
793 #define smaps_hugetlb_range	NULL
794 #endif /* HUGETLB_PAGE */
795 
796 static const struct mm_walk_ops smaps_walk_ops = {
797 	.pmd_entry		= smaps_pte_range,
798 	.hugetlb_entry		= smaps_hugetlb_range,
799 };
800 
801 static const struct mm_walk_ops smaps_shmem_walk_ops = {
802 	.pmd_entry		= smaps_pte_range,
803 	.hugetlb_entry		= smaps_hugetlb_range,
804 	.pte_hole		= smaps_pte_hole,
805 };
806 
smap_gather_stats(struct vm_area_struct * vma,struct mem_size_stats * mss)807 static void smap_gather_stats(struct vm_area_struct *vma,
808 			     struct mem_size_stats *mss)
809 {
810 #ifdef CONFIG_SHMEM
811 	/* In case of smaps_rollup, reset the value from previous vma */
812 	mss->check_shmem_swap = false;
813 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
814 		/*
815 		 * For shared or readonly shmem mappings we know that all
816 		 * swapped out pages belong to the shmem object, and we can
817 		 * obtain the swap value much more efficiently. For private
818 		 * writable mappings, we might have COW pages that are
819 		 * not affected by the parent swapped out pages of the shmem
820 		 * object, so we have to distinguish them during the page walk.
821 		 * Unless we know that the shmem object (or the part mapped by
822 		 * our VMA) has no swapped out pages at all.
823 		 */
824 		unsigned long shmem_swapped = shmem_swap_usage(vma);
825 
826 		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
827 					!(vma->vm_flags & VM_WRITE)) {
828 			mss->swap += shmem_swapped;
829 		} else {
830 			mss->check_shmem_swap = true;
831 			walk_page_vma(vma, &smaps_shmem_walk_ops, mss);
832 			return;
833 		}
834 	}
835 #endif
836 	/* mmap_sem is held in m_start */
837 	walk_page_vma(vma, &smaps_walk_ops, mss);
838 }
839 
840 #define SEQ_PUT_DEC(str, val) \
841 		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
842 
843 /* Show the contents common for smaps and smaps_rollup */
__show_smap(struct seq_file * m,const struct mem_size_stats * mss,bool rollup_mode)844 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
845 	bool rollup_mode)
846 {
847 	SEQ_PUT_DEC("Rss:            ", mss->resident);
848 	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
849 	if (rollup_mode) {
850 		/*
851 		 * These are meaningful only for smaps_rollup, otherwise two of
852 		 * them are zero, and the other one is the same as Pss.
853 		 */
854 		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
855 			mss->pss_anon >> PSS_SHIFT);
856 		SEQ_PUT_DEC(" kB\nPss_File:       ",
857 			mss->pss_file >> PSS_SHIFT);
858 		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
859 			mss->pss_shmem >> PSS_SHIFT);
860 	}
861 	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
862 	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
863 	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
864 	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
865 	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
866 	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
867 	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
868 	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
869 	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
870 	SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp);
871 	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
872 	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
873 				  mss->private_hugetlb >> 10, 7);
874 	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
875 	SEQ_PUT_DEC(" kB\nSwapPss:        ",
876 					mss->swap_pss >> PSS_SHIFT);
877 	SEQ_PUT_DEC(" kB\nLocked:         ",
878 					mss->pss_locked >> PSS_SHIFT);
879 	seq_puts(m, " kB\n");
880 }
881 
show_smap(struct seq_file * m,void * v)882 static int show_smap(struct seq_file *m, void *v)
883 {
884 	struct vm_area_struct *vma = v;
885 	struct mem_size_stats mss;
886 
887 	memset(&mss, 0, sizeof(mss));
888 
889 	smap_gather_stats(vma, &mss);
890 
891 	show_map_vma(m, vma);
892 	if (vma_get_anon_name(vma)) {
893 		seq_puts(m, "Name:           ");
894 		seq_print_vma_name(m, vma);
895 		seq_putc(m, '\n');
896 	}
897 
898 	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
899 	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
900 	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
901 	seq_puts(m, " kB\n");
902 
903 	__show_smap(m, &mss, false);
904 
905 	seq_printf(m, "THPeligible:		%d\n",
906 		   transparent_hugepage_enabled(vma));
907 
908 	if (arch_pkeys_enabled())
909 		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
910 	show_smap_vma_flags(m, vma);
911 
912 	m_cache_vma(m, vma);
913 
914 	return 0;
915 }
916 
show_smaps_rollup(struct seq_file * m,void * v)917 static int show_smaps_rollup(struct seq_file *m, void *v)
918 {
919 	struct proc_maps_private *priv = m->private;
920 	struct mem_size_stats mss;
921 	struct mm_struct *mm;
922 	struct vm_area_struct *vma;
923 	unsigned long last_vma_end = 0;
924 	int ret = 0;
925 
926 	priv->task = get_proc_task(priv->inode);
927 	if (!priv->task)
928 		return -ESRCH;
929 
930 	mm = priv->mm;
931 	if (!mm || !mmget_not_zero(mm)) {
932 		ret = -ESRCH;
933 		goto out_put_task;
934 	}
935 
936 	memset(&mss, 0, sizeof(mss));
937 
938 	ret = down_read_killable(&mm->mmap_sem);
939 	if (ret)
940 		goto out_put_mm;
941 
942 	hold_task_mempolicy(priv);
943 
944 	for (vma = priv->mm->mmap; vma; vma = vma->vm_next) {
945 		smap_gather_stats(vma, &mss);
946 		last_vma_end = vma->vm_end;
947 	}
948 
949 	show_vma_header_prefix(m, priv->mm->mmap->vm_start,
950 			       last_vma_end, 0, 0, 0, 0);
951 	seq_pad(m, ' ');
952 	seq_puts(m, "[rollup]\n");
953 
954 	__show_smap(m, &mss, true);
955 
956 	release_task_mempolicy(priv);
957 	up_read(&mm->mmap_sem);
958 
959 out_put_mm:
960 	mmput(mm);
961 out_put_task:
962 	put_task_struct(priv->task);
963 	priv->task = NULL;
964 
965 	return ret;
966 }
967 #undef SEQ_PUT_DEC
968 
969 static const struct seq_operations proc_pid_smaps_op = {
970 	.start	= m_start,
971 	.next	= m_next,
972 	.stop	= m_stop,
973 	.show	= show_smap
974 };
975 
pid_smaps_open(struct inode * inode,struct file * file)976 static int pid_smaps_open(struct inode *inode, struct file *file)
977 {
978 	return do_maps_open(inode, file, &proc_pid_smaps_op);
979 }
980 
smaps_rollup_open(struct inode * inode,struct file * file)981 static int smaps_rollup_open(struct inode *inode, struct file *file)
982 {
983 	int ret;
984 	struct proc_maps_private *priv;
985 
986 	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
987 	if (!priv)
988 		return -ENOMEM;
989 
990 	ret = single_open(file, show_smaps_rollup, priv);
991 	if (ret)
992 		goto out_free;
993 
994 	priv->inode = inode;
995 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
996 	if (IS_ERR(priv->mm)) {
997 		ret = PTR_ERR(priv->mm);
998 
999 		single_release(inode, file);
1000 		goto out_free;
1001 	}
1002 
1003 	return 0;
1004 
1005 out_free:
1006 	kfree(priv);
1007 	return ret;
1008 }
1009 
smaps_rollup_release(struct inode * inode,struct file * file)1010 static int smaps_rollup_release(struct inode *inode, struct file *file)
1011 {
1012 	struct seq_file *seq = file->private_data;
1013 	struct proc_maps_private *priv = seq->private;
1014 
1015 	if (priv->mm)
1016 		mmdrop(priv->mm);
1017 
1018 	kfree(priv);
1019 	return single_release(inode, file);
1020 }
1021 
1022 const struct file_operations proc_pid_smaps_operations = {
1023 	.open		= pid_smaps_open,
1024 	.read		= seq_read,
1025 	.llseek		= seq_lseek,
1026 	.release	= proc_map_release,
1027 };
1028 
1029 const struct file_operations proc_pid_smaps_rollup_operations = {
1030 	.open		= smaps_rollup_open,
1031 	.read		= seq_read,
1032 	.llseek		= seq_lseek,
1033 	.release	= smaps_rollup_release,
1034 };
1035 
1036 enum clear_refs_types {
1037 	CLEAR_REFS_ALL = 1,
1038 	CLEAR_REFS_ANON,
1039 	CLEAR_REFS_MAPPED,
1040 	CLEAR_REFS_SOFT_DIRTY,
1041 	CLEAR_REFS_MM_HIWATER_RSS,
1042 	CLEAR_REFS_LAST,
1043 };
1044 
1045 struct clear_refs_private {
1046 	enum clear_refs_types type;
1047 };
1048 
1049 #ifdef CONFIG_MEM_SOFT_DIRTY
clear_soft_dirty(struct vm_area_struct * vma,unsigned long addr,pte_t * pte)1050 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1051 		unsigned long addr, pte_t *pte)
1052 {
1053 	/*
1054 	 * The soft-dirty tracker uses #PF-s to catch writes
1055 	 * to pages, so write-protect the pte as well. See the
1056 	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
1057 	 * of how soft-dirty works.
1058 	 */
1059 	pte_t ptent = *pte;
1060 
1061 	if (pte_present(ptent)) {
1062 		pte_t old_pte;
1063 
1064 		old_pte = ptep_modify_prot_start(vma, addr, pte);
1065 		ptent = pte_wrprotect(old_pte);
1066 		ptent = pte_clear_soft_dirty(ptent);
1067 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1068 	} else if (is_swap_pte(ptent)) {
1069 		ptent = pte_swp_clear_soft_dirty(ptent);
1070 		set_pte_at(vma->vm_mm, addr, pte, ptent);
1071 	}
1072 }
1073 #else
clear_soft_dirty(struct vm_area_struct * vma,unsigned long addr,pte_t * pte)1074 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1075 		unsigned long addr, pte_t *pte)
1076 {
1077 }
1078 #endif
1079 
1080 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
clear_soft_dirty_pmd(struct vm_area_struct * vma,unsigned long addr,pmd_t * pmdp)1081 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1082 		unsigned long addr, pmd_t *pmdp)
1083 {
1084 	pmd_t old, pmd = *pmdp;
1085 
1086 	if (pmd_present(pmd)) {
1087 		/* See comment in change_huge_pmd() */
1088 		old = pmdp_invalidate(vma, addr, pmdp);
1089 		if (pmd_dirty(old))
1090 			pmd = pmd_mkdirty(pmd);
1091 		if (pmd_young(old))
1092 			pmd = pmd_mkyoung(pmd);
1093 
1094 		pmd = pmd_wrprotect(pmd);
1095 		pmd = pmd_clear_soft_dirty(pmd);
1096 
1097 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1098 	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1099 		pmd = pmd_swp_clear_soft_dirty(pmd);
1100 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1101 	}
1102 }
1103 #else
clear_soft_dirty_pmd(struct vm_area_struct * vma,unsigned long addr,pmd_t * pmdp)1104 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1105 		unsigned long addr, pmd_t *pmdp)
1106 {
1107 }
1108 #endif
1109 
clear_refs_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)1110 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1111 				unsigned long end, struct mm_walk *walk)
1112 {
1113 	struct clear_refs_private *cp = walk->private;
1114 	struct vm_area_struct *vma = walk->vma;
1115 	pte_t *pte, ptent;
1116 	spinlock_t *ptl;
1117 	struct page *page;
1118 
1119 	ptl = pmd_trans_huge_lock(pmd, vma);
1120 	if (ptl) {
1121 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1122 			clear_soft_dirty_pmd(vma, addr, pmd);
1123 			goto out;
1124 		}
1125 
1126 		if (!pmd_present(*pmd))
1127 			goto out;
1128 
1129 		page = pmd_page(*pmd);
1130 
1131 		/* Clear accessed and referenced bits. */
1132 		pmdp_test_and_clear_young(vma, addr, pmd);
1133 		test_and_clear_page_young(page);
1134 		ClearPageReferenced(page);
1135 out:
1136 		spin_unlock(ptl);
1137 		return 0;
1138 	}
1139 
1140 	if (pmd_trans_unstable(pmd))
1141 		return 0;
1142 
1143 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1144 	for (; addr != end; pte++, addr += PAGE_SIZE) {
1145 		ptent = *pte;
1146 
1147 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1148 			clear_soft_dirty(vma, addr, pte);
1149 			continue;
1150 		}
1151 
1152 		if (!pte_present(ptent))
1153 			continue;
1154 
1155 		page = vm_normal_page(vma, addr, ptent);
1156 		if (!page)
1157 			continue;
1158 
1159 		/* Clear accessed and referenced bits. */
1160 		ptep_test_and_clear_young(vma, addr, pte);
1161 		test_and_clear_page_young(page);
1162 		ClearPageReferenced(page);
1163 	}
1164 	pte_unmap_unlock(pte - 1, ptl);
1165 	cond_resched();
1166 	return 0;
1167 }
1168 
clear_refs_test_walk(unsigned long start,unsigned long end,struct mm_walk * walk)1169 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1170 				struct mm_walk *walk)
1171 {
1172 	struct clear_refs_private *cp = walk->private;
1173 	struct vm_area_struct *vma = walk->vma;
1174 
1175 	if (vma->vm_flags & VM_PFNMAP)
1176 		return 1;
1177 
1178 	/*
1179 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1180 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1181 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1182 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1183 	 */
1184 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1185 		return 1;
1186 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1187 		return 1;
1188 	return 0;
1189 }
1190 
1191 static const struct mm_walk_ops clear_refs_walk_ops = {
1192 	.pmd_entry		= clear_refs_pte_range,
1193 	.test_walk		= clear_refs_test_walk,
1194 };
1195 
clear_refs_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1196 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1197 				size_t count, loff_t *ppos)
1198 {
1199 	struct task_struct *task;
1200 	char buffer[PROC_NUMBUF];
1201 	struct mm_struct *mm;
1202 	struct vm_area_struct *vma;
1203 	enum clear_refs_types type;
1204 	struct mmu_gather tlb;
1205 	int itype;
1206 	int rv;
1207 
1208 	memset(buffer, 0, sizeof(buffer));
1209 	if (count > sizeof(buffer) - 1)
1210 		count = sizeof(buffer) - 1;
1211 	if (copy_from_user(buffer, buf, count))
1212 		return -EFAULT;
1213 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1214 	if (rv < 0)
1215 		return rv;
1216 	type = (enum clear_refs_types)itype;
1217 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1218 		return -EINVAL;
1219 
1220 	task = get_proc_task(file_inode(file));
1221 	if (!task)
1222 		return -ESRCH;
1223 	mm = get_task_mm(task);
1224 	if (mm) {
1225 		struct mmu_notifier_range range;
1226 		struct clear_refs_private cp = {
1227 			.type = type,
1228 		};
1229 
1230 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1231 			if (down_write_killable(&mm->mmap_sem)) {
1232 				count = -EINTR;
1233 				goto out_mm;
1234 			}
1235 
1236 			/*
1237 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1238 			 * resident set size to this mm's current rss value.
1239 			 */
1240 			reset_mm_hiwater_rss(mm);
1241 			up_write(&mm->mmap_sem);
1242 			goto out_mm;
1243 		}
1244 
1245 		if (down_read_killable(&mm->mmap_sem)) {
1246 			count = -EINTR;
1247 			goto out_mm;
1248 		}
1249 		tlb_gather_mmu(&tlb, mm, 0, -1);
1250 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1251 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
1252 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1253 					continue;
1254 				up_read(&mm->mmap_sem);
1255 				if (down_write_killable(&mm->mmap_sem)) {
1256 					count = -EINTR;
1257 					goto out_mm;
1258 				}
1259 				/*
1260 				 * Avoid to modify vma->vm_flags
1261 				 * without locked ops while the
1262 				 * coredump reads the vm_flags.
1263 				 */
1264 				if (!mmget_still_valid(mm)) {
1265 					/*
1266 					 * Silently return "count"
1267 					 * like if get_task_mm()
1268 					 * failed. FIXME: should this
1269 					 * function have returned
1270 					 * -ESRCH if get_task_mm()
1271 					 * failed like if
1272 					 * get_proc_task() fails?
1273 					 */
1274 					up_write(&mm->mmap_sem);
1275 					goto out_mm;
1276 				}
1277 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
1278 					vma->vm_flags &= ~VM_SOFTDIRTY;
1279 					vma_set_page_prot(vma);
1280 				}
1281 				downgrade_write(&mm->mmap_sem);
1282 				break;
1283 			}
1284 
1285 			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1286 						0, NULL, mm, 0, -1UL);
1287 			mmu_notifier_invalidate_range_start(&range);
1288 		}
1289 		walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
1290 				&cp);
1291 		if (type == CLEAR_REFS_SOFT_DIRTY)
1292 			mmu_notifier_invalidate_range_end(&range);
1293 		tlb_finish_mmu(&tlb, 0, -1);
1294 		up_read(&mm->mmap_sem);
1295 out_mm:
1296 		mmput(mm);
1297 	}
1298 	put_task_struct(task);
1299 
1300 	return count;
1301 }
1302 
1303 const struct file_operations proc_clear_refs_operations = {
1304 	.write		= clear_refs_write,
1305 	.llseek		= noop_llseek,
1306 };
1307 
1308 typedef struct {
1309 	u64 pme;
1310 } pagemap_entry_t;
1311 
1312 struct pagemapread {
1313 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1314 	pagemap_entry_t *buffer;
1315 	bool show_pfn;
1316 };
1317 
1318 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1319 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1320 
1321 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1322 #define PM_PFRAME_BITS		55
1323 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1324 #define PM_SOFT_DIRTY		BIT_ULL(55)
1325 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1326 #define PM_FILE			BIT_ULL(61)
1327 #define PM_SWAP			BIT_ULL(62)
1328 #define PM_PRESENT		BIT_ULL(63)
1329 
1330 #define PM_END_OF_BUFFER    1
1331 
make_pme(u64 frame,u64 flags)1332 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1333 {
1334 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1335 }
1336 
add_to_pagemap(unsigned long addr,pagemap_entry_t * pme,struct pagemapread * pm)1337 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1338 			  struct pagemapread *pm)
1339 {
1340 	pm->buffer[pm->pos++] = *pme;
1341 	if (pm->pos >= pm->len)
1342 		return PM_END_OF_BUFFER;
1343 	return 0;
1344 }
1345 
pagemap_pte_hole(unsigned long start,unsigned long end,struct mm_walk * walk)1346 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1347 				struct mm_walk *walk)
1348 {
1349 	struct pagemapread *pm = walk->private;
1350 	unsigned long addr = start;
1351 	int err = 0;
1352 
1353 	while (addr < end) {
1354 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1355 		pagemap_entry_t pme = make_pme(0, 0);
1356 		/* End of address space hole, which we mark as non-present. */
1357 		unsigned long hole_end;
1358 
1359 		if (vma)
1360 			hole_end = min(end, vma->vm_start);
1361 		else
1362 			hole_end = end;
1363 
1364 		for (; addr < hole_end; addr += PAGE_SIZE) {
1365 			err = add_to_pagemap(addr, &pme, pm);
1366 			if (err)
1367 				goto out;
1368 		}
1369 
1370 		if (!vma)
1371 			break;
1372 
1373 		/* Addresses in the VMA. */
1374 		if (vma->vm_flags & VM_SOFTDIRTY)
1375 			pme = make_pme(0, PM_SOFT_DIRTY);
1376 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1377 			err = add_to_pagemap(addr, &pme, pm);
1378 			if (err)
1379 				goto out;
1380 		}
1381 	}
1382 out:
1383 	return err;
1384 }
1385 
pte_to_pagemap_entry(struct pagemapread * pm,struct vm_area_struct * vma,unsigned long addr,pte_t pte)1386 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1387 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1388 {
1389 	u64 frame = 0, flags = 0;
1390 	struct page *page = NULL;
1391 
1392 	if (pte_present(pte)) {
1393 		if (pm->show_pfn)
1394 			frame = pte_pfn(pte);
1395 		flags |= PM_PRESENT;
1396 		page = vm_normal_page(vma, addr, pte);
1397 		if (pte_soft_dirty(pte))
1398 			flags |= PM_SOFT_DIRTY;
1399 	} else if (is_swap_pte(pte)) {
1400 		swp_entry_t entry;
1401 		if (pte_swp_soft_dirty(pte))
1402 			flags |= PM_SOFT_DIRTY;
1403 		entry = pte_to_swp_entry(pte);
1404 		if (pm->show_pfn)
1405 			frame = swp_type(entry) |
1406 				(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1407 		flags |= PM_SWAP;
1408 		if (is_migration_entry(entry))
1409 			page = migration_entry_to_page(entry);
1410 
1411 		if (is_device_private_entry(entry))
1412 			page = device_private_entry_to_page(entry);
1413 	}
1414 
1415 	if (page && !PageAnon(page))
1416 		flags |= PM_FILE;
1417 	if (page && page_mapcount(page) == 1)
1418 		flags |= PM_MMAP_EXCLUSIVE;
1419 	if (vma->vm_flags & VM_SOFTDIRTY)
1420 		flags |= PM_SOFT_DIRTY;
1421 
1422 	return make_pme(frame, flags);
1423 }
1424 
pagemap_pmd_range(pmd_t * pmdp,unsigned long addr,unsigned long end,struct mm_walk * walk)1425 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1426 			     struct mm_walk *walk)
1427 {
1428 	struct vm_area_struct *vma = walk->vma;
1429 	struct pagemapread *pm = walk->private;
1430 	spinlock_t *ptl;
1431 	pte_t *pte, *orig_pte;
1432 	int err = 0;
1433 
1434 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1435 	ptl = pmd_trans_huge_lock(pmdp, vma);
1436 	if (ptl) {
1437 		u64 flags = 0, frame = 0;
1438 		pmd_t pmd = *pmdp;
1439 		struct page *page = NULL;
1440 
1441 		if (vma->vm_flags & VM_SOFTDIRTY)
1442 			flags |= PM_SOFT_DIRTY;
1443 
1444 		if (pmd_present(pmd)) {
1445 			page = pmd_page(pmd);
1446 
1447 			flags |= PM_PRESENT;
1448 			if (pmd_soft_dirty(pmd))
1449 				flags |= PM_SOFT_DIRTY;
1450 			if (pm->show_pfn)
1451 				frame = pmd_pfn(pmd) +
1452 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1453 		}
1454 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1455 		else if (is_swap_pmd(pmd)) {
1456 			swp_entry_t entry = pmd_to_swp_entry(pmd);
1457 			unsigned long offset;
1458 
1459 			if (pm->show_pfn) {
1460 				offset = swp_offset(entry) +
1461 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
1462 				frame = swp_type(entry) |
1463 					(offset << MAX_SWAPFILES_SHIFT);
1464 			}
1465 			flags |= PM_SWAP;
1466 			if (pmd_swp_soft_dirty(pmd))
1467 				flags |= PM_SOFT_DIRTY;
1468 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1469 			page = migration_entry_to_page(entry);
1470 		}
1471 #endif
1472 
1473 		if (page && page_mapcount(page) == 1)
1474 			flags |= PM_MMAP_EXCLUSIVE;
1475 
1476 		for (; addr != end; addr += PAGE_SIZE) {
1477 			pagemap_entry_t pme = make_pme(frame, flags);
1478 
1479 			err = add_to_pagemap(addr, &pme, pm);
1480 			if (err)
1481 				break;
1482 			if (pm->show_pfn) {
1483 				if (flags & PM_PRESENT)
1484 					frame++;
1485 				else if (flags & PM_SWAP)
1486 					frame += (1 << MAX_SWAPFILES_SHIFT);
1487 			}
1488 		}
1489 		spin_unlock(ptl);
1490 		return err;
1491 	}
1492 
1493 	if (pmd_trans_unstable(pmdp))
1494 		return 0;
1495 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1496 
1497 	/*
1498 	 * We can assume that @vma always points to a valid one and @end never
1499 	 * goes beyond vma->vm_end.
1500 	 */
1501 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1502 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1503 		pagemap_entry_t pme;
1504 
1505 		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1506 		err = add_to_pagemap(addr, &pme, pm);
1507 		if (err)
1508 			break;
1509 	}
1510 	pte_unmap_unlock(orig_pte, ptl);
1511 
1512 	cond_resched();
1513 
1514 	return err;
1515 }
1516 
1517 #ifdef CONFIG_HUGETLB_PAGE
1518 /* This function walks within one hugetlb entry in the single call */
pagemap_hugetlb_range(pte_t * ptep,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)1519 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1520 				 unsigned long addr, unsigned long end,
1521 				 struct mm_walk *walk)
1522 {
1523 	struct pagemapread *pm = walk->private;
1524 	struct vm_area_struct *vma = walk->vma;
1525 	u64 flags = 0, frame = 0;
1526 	int err = 0;
1527 	pte_t pte;
1528 
1529 	if (vma->vm_flags & VM_SOFTDIRTY)
1530 		flags |= PM_SOFT_DIRTY;
1531 
1532 	pte = huge_ptep_get(ptep);
1533 	if (pte_present(pte)) {
1534 		struct page *page = pte_page(pte);
1535 
1536 		if (!PageAnon(page))
1537 			flags |= PM_FILE;
1538 
1539 		if (page_mapcount(page) == 1)
1540 			flags |= PM_MMAP_EXCLUSIVE;
1541 
1542 		flags |= PM_PRESENT;
1543 		if (pm->show_pfn)
1544 			frame = pte_pfn(pte) +
1545 				((addr & ~hmask) >> PAGE_SHIFT);
1546 	}
1547 
1548 	for (; addr != end; addr += PAGE_SIZE) {
1549 		pagemap_entry_t pme = make_pme(frame, flags);
1550 
1551 		err = add_to_pagemap(addr, &pme, pm);
1552 		if (err)
1553 			return err;
1554 		if (pm->show_pfn && (flags & PM_PRESENT))
1555 			frame++;
1556 	}
1557 
1558 	cond_resched();
1559 
1560 	return err;
1561 }
1562 #else
1563 #define pagemap_hugetlb_range	NULL
1564 #endif /* HUGETLB_PAGE */
1565 
1566 static const struct mm_walk_ops pagemap_ops = {
1567 	.pmd_entry	= pagemap_pmd_range,
1568 	.pte_hole	= pagemap_pte_hole,
1569 	.hugetlb_entry	= pagemap_hugetlb_range,
1570 };
1571 
1572 /*
1573  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1574  *
1575  * For each page in the address space, this file contains one 64-bit entry
1576  * consisting of the following:
1577  *
1578  * Bits 0-54  page frame number (PFN) if present
1579  * Bits 0-4   swap type if swapped
1580  * Bits 5-54  swap offset if swapped
1581  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1582  * Bit  56    page exclusively mapped
1583  * Bits 57-60 zero
1584  * Bit  61    page is file-page or shared-anon
1585  * Bit  62    page swapped
1586  * Bit  63    page present
1587  *
1588  * If the page is not present but in swap, then the PFN contains an
1589  * encoding of the swap file number and the page's offset into the
1590  * swap. Unmapped pages return a null PFN. This allows determining
1591  * precisely which pages are mapped (or in swap) and comparing mapped
1592  * pages between processes.
1593  *
1594  * Efficient users of this interface will use /proc/pid/maps to
1595  * determine which areas of memory are actually mapped and llseek to
1596  * skip over unmapped regions.
1597  */
pagemap_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1598 static ssize_t pagemap_read(struct file *file, char __user *buf,
1599 			    size_t count, loff_t *ppos)
1600 {
1601 	struct mm_struct *mm = file->private_data;
1602 	struct pagemapread pm;
1603 	unsigned long src;
1604 	unsigned long svpfn;
1605 	unsigned long start_vaddr;
1606 	unsigned long end_vaddr;
1607 	int ret = 0, copied = 0;
1608 
1609 	if (!mm || !mmget_not_zero(mm))
1610 		goto out;
1611 
1612 	ret = -EINVAL;
1613 	/* file position must be aligned */
1614 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1615 		goto out_mm;
1616 
1617 	ret = 0;
1618 	if (!count)
1619 		goto out_mm;
1620 
1621 	/* do not disclose physical addresses: attack vector */
1622 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1623 
1624 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1625 	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1626 	ret = -ENOMEM;
1627 	if (!pm.buffer)
1628 		goto out_mm;
1629 
1630 	src = *ppos;
1631 	svpfn = src / PM_ENTRY_BYTES;
1632 	start_vaddr = svpfn << PAGE_SHIFT;
1633 	end_vaddr = mm->task_size;
1634 
1635 	/* watch out for wraparound */
1636 	if (svpfn > mm->task_size >> PAGE_SHIFT)
1637 		start_vaddr = end_vaddr;
1638 
1639 	/*
1640 	 * The odds are that this will stop walking way
1641 	 * before end_vaddr, because the length of the
1642 	 * user buffer is tracked in "pm", and the walk
1643 	 * will stop when we hit the end of the buffer.
1644 	 */
1645 	ret = 0;
1646 	while (count && (start_vaddr < end_vaddr)) {
1647 		int len;
1648 		unsigned long end;
1649 
1650 		pm.pos = 0;
1651 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1652 		/* overflow ? */
1653 		if (end < start_vaddr || end > end_vaddr)
1654 			end = end_vaddr;
1655 		ret = down_read_killable(&mm->mmap_sem);
1656 		if (ret)
1657 			goto out_free;
1658 		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1659 		up_read(&mm->mmap_sem);
1660 		start_vaddr = end;
1661 
1662 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1663 		if (copy_to_user(buf, pm.buffer, len)) {
1664 			ret = -EFAULT;
1665 			goto out_free;
1666 		}
1667 		copied += len;
1668 		buf += len;
1669 		count -= len;
1670 	}
1671 	*ppos += copied;
1672 	if (!ret || ret == PM_END_OF_BUFFER)
1673 		ret = copied;
1674 
1675 out_free:
1676 	kfree(pm.buffer);
1677 out_mm:
1678 	mmput(mm);
1679 out:
1680 	return ret;
1681 }
1682 
pagemap_open(struct inode * inode,struct file * file)1683 static int pagemap_open(struct inode *inode, struct file *file)
1684 {
1685 	struct mm_struct *mm;
1686 
1687 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1688 	if (IS_ERR(mm))
1689 		return PTR_ERR(mm);
1690 	file->private_data = mm;
1691 	return 0;
1692 }
1693 
pagemap_release(struct inode * inode,struct file * file)1694 static int pagemap_release(struct inode *inode, struct file *file)
1695 {
1696 	struct mm_struct *mm = file->private_data;
1697 
1698 	if (mm)
1699 		mmdrop(mm);
1700 	return 0;
1701 }
1702 
1703 const struct file_operations proc_pagemap_operations = {
1704 	.llseek		= mem_lseek, /* borrow this */
1705 	.read		= pagemap_read,
1706 	.open		= pagemap_open,
1707 	.release	= pagemap_release,
1708 };
1709 #endif /* CONFIG_PROC_PAGE_MONITOR */
1710 
1711 #ifdef CONFIG_NUMA
1712 
1713 struct numa_maps {
1714 	unsigned long pages;
1715 	unsigned long anon;
1716 	unsigned long active;
1717 	unsigned long writeback;
1718 	unsigned long mapcount_max;
1719 	unsigned long dirty;
1720 	unsigned long swapcache;
1721 	unsigned long node[MAX_NUMNODES];
1722 };
1723 
1724 struct numa_maps_private {
1725 	struct proc_maps_private proc_maps;
1726 	struct numa_maps md;
1727 };
1728 
gather_stats(struct page * page,struct numa_maps * md,int pte_dirty,unsigned long nr_pages)1729 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1730 			unsigned long nr_pages)
1731 {
1732 	int count = page_mapcount(page);
1733 
1734 	md->pages += nr_pages;
1735 	if (pte_dirty || PageDirty(page))
1736 		md->dirty += nr_pages;
1737 
1738 	if (PageSwapCache(page))
1739 		md->swapcache += nr_pages;
1740 
1741 	if (PageActive(page) || PageUnevictable(page))
1742 		md->active += nr_pages;
1743 
1744 	if (PageWriteback(page))
1745 		md->writeback += nr_pages;
1746 
1747 	if (PageAnon(page))
1748 		md->anon += nr_pages;
1749 
1750 	if (count > md->mapcount_max)
1751 		md->mapcount_max = count;
1752 
1753 	md->node[page_to_nid(page)] += nr_pages;
1754 }
1755 
can_gather_numa_stats(pte_t pte,struct vm_area_struct * vma,unsigned long addr)1756 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1757 		unsigned long addr)
1758 {
1759 	struct page *page;
1760 	int nid;
1761 
1762 	if (!pte_present(pte))
1763 		return NULL;
1764 
1765 	page = vm_normal_page(vma, addr, pte);
1766 	if (!page)
1767 		return NULL;
1768 
1769 	if (PageReserved(page))
1770 		return NULL;
1771 
1772 	nid = page_to_nid(page);
1773 	if (!node_isset(nid, node_states[N_MEMORY]))
1774 		return NULL;
1775 
1776 	return page;
1777 }
1778 
1779 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
can_gather_numa_stats_pmd(pmd_t pmd,struct vm_area_struct * vma,unsigned long addr)1780 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1781 					      struct vm_area_struct *vma,
1782 					      unsigned long addr)
1783 {
1784 	struct page *page;
1785 	int nid;
1786 
1787 	if (!pmd_present(pmd))
1788 		return NULL;
1789 
1790 	page = vm_normal_page_pmd(vma, addr, pmd);
1791 	if (!page)
1792 		return NULL;
1793 
1794 	if (PageReserved(page))
1795 		return NULL;
1796 
1797 	nid = page_to_nid(page);
1798 	if (!node_isset(nid, node_states[N_MEMORY]))
1799 		return NULL;
1800 
1801 	return page;
1802 }
1803 #endif
1804 
gather_pte_stats(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)1805 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1806 		unsigned long end, struct mm_walk *walk)
1807 {
1808 	struct numa_maps *md = walk->private;
1809 	struct vm_area_struct *vma = walk->vma;
1810 	spinlock_t *ptl;
1811 	pte_t *orig_pte;
1812 	pte_t *pte;
1813 
1814 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1815 	ptl = pmd_trans_huge_lock(pmd, vma);
1816 	if (ptl) {
1817 		struct page *page;
1818 
1819 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1820 		if (page)
1821 			gather_stats(page, md, pmd_dirty(*pmd),
1822 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1823 		spin_unlock(ptl);
1824 		return 0;
1825 	}
1826 
1827 	if (pmd_trans_unstable(pmd))
1828 		return 0;
1829 #endif
1830 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1831 	do {
1832 		struct page *page = can_gather_numa_stats(*pte, vma, addr);
1833 		if (!page)
1834 			continue;
1835 		gather_stats(page, md, pte_dirty(*pte), 1);
1836 
1837 	} while (pte++, addr += PAGE_SIZE, addr != end);
1838 	pte_unmap_unlock(orig_pte, ptl);
1839 	cond_resched();
1840 	return 0;
1841 }
1842 #ifdef CONFIG_HUGETLB_PAGE
gather_hugetlb_stats(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)1843 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1844 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1845 {
1846 	pte_t huge_pte = huge_ptep_get(pte);
1847 	struct numa_maps *md;
1848 	struct page *page;
1849 
1850 	if (!pte_present(huge_pte))
1851 		return 0;
1852 
1853 	page = pte_page(huge_pte);
1854 	if (!page)
1855 		return 0;
1856 
1857 	md = walk->private;
1858 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1859 	return 0;
1860 }
1861 
1862 #else
gather_hugetlb_stats(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)1863 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1864 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1865 {
1866 	return 0;
1867 }
1868 #endif
1869 
1870 static const struct mm_walk_ops show_numa_ops = {
1871 	.hugetlb_entry = gather_hugetlb_stats,
1872 	.pmd_entry = gather_pte_stats,
1873 };
1874 
1875 /*
1876  * Display pages allocated per node and memory policy via /proc.
1877  */
show_numa_map(struct seq_file * m,void * v)1878 static int show_numa_map(struct seq_file *m, void *v)
1879 {
1880 	struct numa_maps_private *numa_priv = m->private;
1881 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1882 	struct vm_area_struct *vma = v;
1883 	struct numa_maps *md = &numa_priv->md;
1884 	struct file *file = vma->vm_file;
1885 	struct mm_struct *mm = vma->vm_mm;
1886 	struct mempolicy *pol;
1887 	char buffer[64];
1888 	int nid;
1889 
1890 	if (!mm)
1891 		return 0;
1892 
1893 	/* Ensure we start with an empty set of numa_maps statistics. */
1894 	memset(md, 0, sizeof(*md));
1895 
1896 	pol = __get_vma_policy(vma, vma->vm_start);
1897 	if (pol) {
1898 		mpol_to_str(buffer, sizeof(buffer), pol);
1899 		mpol_cond_put(pol);
1900 	} else {
1901 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1902 	}
1903 
1904 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1905 
1906 	if (file) {
1907 		seq_puts(m, " file=");
1908 		seq_file_path(m, file, "\n\t= ");
1909 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1910 		seq_puts(m, " heap");
1911 	} else if (is_stack(vma)) {
1912 		seq_puts(m, " stack");
1913 	}
1914 
1915 	if (is_vm_hugetlb_page(vma))
1916 		seq_puts(m, " huge");
1917 
1918 	/* mmap_sem is held by m_start */
1919 	walk_page_vma(vma, &show_numa_ops, md);
1920 
1921 	if (!md->pages)
1922 		goto out;
1923 
1924 	if (md->anon)
1925 		seq_printf(m, " anon=%lu", md->anon);
1926 
1927 	if (md->dirty)
1928 		seq_printf(m, " dirty=%lu", md->dirty);
1929 
1930 	if (md->pages != md->anon && md->pages != md->dirty)
1931 		seq_printf(m, " mapped=%lu", md->pages);
1932 
1933 	if (md->mapcount_max > 1)
1934 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1935 
1936 	if (md->swapcache)
1937 		seq_printf(m, " swapcache=%lu", md->swapcache);
1938 
1939 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1940 		seq_printf(m, " active=%lu", md->active);
1941 
1942 	if (md->writeback)
1943 		seq_printf(m, " writeback=%lu", md->writeback);
1944 
1945 	for_each_node_state(nid, N_MEMORY)
1946 		if (md->node[nid])
1947 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1948 
1949 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1950 out:
1951 	seq_putc(m, '\n');
1952 	m_cache_vma(m, vma);
1953 	return 0;
1954 }
1955 
1956 static const struct seq_operations proc_pid_numa_maps_op = {
1957 	.start  = m_start,
1958 	.next   = m_next,
1959 	.stop   = m_stop,
1960 	.show   = show_numa_map,
1961 };
1962 
pid_numa_maps_open(struct inode * inode,struct file * file)1963 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1964 {
1965 	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1966 				sizeof(struct numa_maps_private));
1967 }
1968 
1969 const struct file_operations proc_pid_numa_maps_operations = {
1970 	.open		= pid_numa_maps_open,
1971 	.read		= seq_read,
1972 	.llseek		= seq_lseek,
1973 	.release	= proc_map_release,
1974 };
1975 
1976 #endif /* CONFIG_NUMA */
1977