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1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/pagewalk.h>
3 #include <linux/mm_inline.h>
4 #include <linux/hugetlb.h>
5 #include <linux/huge_mm.h>
6 #include <linux/mount.h>
7 #include <linux/ksm.h>
8 #include <linux/seq_file.h>
9 #include <linux/highmem.h>
10 #include <linux/ptrace.h>
11 #include <linux/slab.h>
12 #include <linux/pagemap.h>
13 #include <linux/mempolicy.h>
14 #include <linux/rmap.h>
15 #include <linux/swap.h>
16 #include <linux/sched/mm.h>
17 #include <linux/swapops.h>
18 #include <linux/mmu_notifier.h>
19 #include <linux/page_idle.h>
20 #include <linux/shmem_fs.h>
21 #include <linux/uaccess.h>
22 #include <linux/pkeys.h>
23 #ifdef CONFIG_MEM_PURGEABLE
24 #include <linux/mm_purgeable.h>
25 #endif
26 
27 #include <asm/elf.h>
28 #include <asm/tlb.h>
29 #include <asm/tlbflush.h>
30 #include "internal.h"
31 #include <linux/hck/lite_hck_hideaddr.h>
32 
33 #define SEQ_PUT_DEC(str, val) \
34 		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
task_mem(struct seq_file * m,struct mm_struct * mm)35 void task_mem(struct seq_file *m, struct mm_struct *mm)
36 {
37 	unsigned long text, lib, swap, anon, file, shmem;
38 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
39 #ifdef CONFIG_MEM_PURGEABLE
40 	unsigned long nr_purg_sum = 0, nr_purg_pin = 0;
41 
42 	mm_purg_pages_info(mm, &nr_purg_sum, &nr_purg_pin);
43 #endif
44 
45 	anon = get_mm_counter_sum(mm, MM_ANONPAGES);
46 	file = get_mm_counter_sum(mm, MM_FILEPAGES);
47 	shmem = get_mm_counter_sum(mm, MM_SHMEMPAGES);
48 
49 	/*
50 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
51 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
52 	 * collector of these hiwater stats must therefore get total_vm
53 	 * and rss too, which will usually be the higher.  Barriers? not
54 	 * worth the effort, such snapshots can always be inconsistent.
55 	 */
56 	hiwater_vm = total_vm = mm->total_vm;
57 	if (hiwater_vm < mm->hiwater_vm)
58 		hiwater_vm = mm->hiwater_vm;
59 	hiwater_rss = total_rss = anon + file + shmem;
60 	if (hiwater_rss < mm->hiwater_rss)
61 		hiwater_rss = mm->hiwater_rss;
62 
63 	/* split executable areas between text and lib */
64 	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
65 	text = min(text, mm->exec_vm << PAGE_SHIFT);
66 	lib = (mm->exec_vm << PAGE_SHIFT) - text;
67 
68 	swap = get_mm_counter_sum(mm, MM_SWAPENTS);
69 	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
70 	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
71 	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
72 	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
73 	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
74 	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
75 	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
76 	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
77 	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
78 	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
79 	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
80 	seq_put_decimal_ull_width(m,
81 		    " kB\nVmExe:\t", text >> 10, 8);
82 	seq_put_decimal_ull_width(m,
83 		    " kB\nVmLib:\t", lib >> 10, 8);
84 	seq_put_decimal_ull_width(m,
85 		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
86 	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
87 #ifdef CONFIG_MEM_PURGEABLE
88 	SEQ_PUT_DEC(" kB\nPurgSum:\t", nr_purg_sum);
89 	SEQ_PUT_DEC(" kB\nPurgPin:\t", nr_purg_pin);
90 #endif
91 	seq_puts(m, " kB\n");
92 	hugetlb_report_usage(m, mm);
93 }
94 #undef SEQ_PUT_DEC
95 
task_vsize(struct mm_struct * mm)96 unsigned long task_vsize(struct mm_struct *mm)
97 {
98 	return PAGE_SIZE * mm->total_vm;
99 }
100 
task_statm(struct mm_struct * mm,unsigned long * shared,unsigned long * text,unsigned long * data,unsigned long * resident)101 unsigned long task_statm(struct mm_struct *mm,
102 			 unsigned long *shared, unsigned long *text,
103 			 unsigned long *data, unsigned long *resident)
104 {
105 	*shared = get_mm_counter_sum(mm, MM_FILEPAGES) +
106 			get_mm_counter_sum(mm, MM_SHMEMPAGES);
107 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
108 								>> PAGE_SHIFT;
109 	*data = mm->data_vm + mm->stack_vm;
110 	*resident = *shared + get_mm_counter_sum(mm, MM_ANONPAGES);
111 	return mm->total_vm;
112 }
113 
114 #ifdef CONFIG_NUMA
115 /*
116  * Save get_task_policy() for show_numa_map().
117  */
hold_task_mempolicy(struct proc_maps_private * priv)118 static void hold_task_mempolicy(struct proc_maps_private *priv)
119 {
120 	struct task_struct *task = priv->task;
121 
122 	task_lock(task);
123 	priv->task_mempolicy = get_task_policy(task);
124 	mpol_get(priv->task_mempolicy);
125 	task_unlock(task);
126 }
release_task_mempolicy(struct proc_maps_private * priv)127 static void release_task_mempolicy(struct proc_maps_private *priv)
128 {
129 	mpol_put(priv->task_mempolicy);
130 }
131 #else
hold_task_mempolicy(struct proc_maps_private * priv)132 static void hold_task_mempolicy(struct proc_maps_private *priv)
133 {
134 }
release_task_mempolicy(struct proc_maps_private * priv)135 static void release_task_mempolicy(struct proc_maps_private *priv)
136 {
137 }
138 #endif
139 
proc_get_vma(struct proc_maps_private * priv,loff_t * ppos)140 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
141 						loff_t *ppos)
142 {
143 	struct vm_area_struct *vma = vma_next(&priv->iter);
144 
145 	if (vma) {
146 		*ppos = vma->vm_start;
147 	} else {
148 		*ppos = -2UL;
149 		vma = get_gate_vma(priv->mm);
150 	}
151 
152 	return vma;
153 }
154 
m_start(struct seq_file * m,loff_t * ppos)155 static void *m_start(struct seq_file *m, loff_t *ppos)
156 {
157 	struct proc_maps_private *priv = m->private;
158 	unsigned long last_addr = *ppos;
159 	struct mm_struct *mm;
160 
161 	/* See m_next(). 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 || !mmget_not_zero(mm)) {
171 		put_task_struct(priv->task);
172 		priv->task = NULL;
173 		return NULL;
174 	}
175 
176 	if (mmap_read_lock_killable(mm)) {
177 		mmput(mm);
178 		put_task_struct(priv->task);
179 		priv->task = NULL;
180 		return ERR_PTR(-EINTR);
181 	}
182 
183 	vma_iter_init(&priv->iter, mm, last_addr);
184 	hold_task_mempolicy(priv);
185 	if (last_addr == -2UL)
186 		return get_gate_vma(mm);
187 
188 	return proc_get_vma(priv, ppos);
189 }
190 
m_next(struct seq_file * m,void * v,loff_t * ppos)191 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
192 {
193 	if (*ppos == -2UL) {
194 		*ppos = -1UL;
195 		return NULL;
196 	}
197 	return proc_get_vma(m->private, ppos);
198 }
199 
m_stop(struct seq_file * m,void * v)200 static void m_stop(struct seq_file *m, void *v)
201 {
202 	struct proc_maps_private *priv = m->private;
203 	struct mm_struct *mm = priv->mm;
204 
205 	if (!priv->task)
206 		return;
207 
208 	release_task_mempolicy(priv);
209 	mmap_read_unlock(mm);
210 	mmput(mm);
211 	put_task_struct(priv->task);
212 	priv->task = NULL;
213 }
214 
proc_maps_open(struct inode * inode,struct file * file,const struct seq_operations * ops,int psize)215 static int proc_maps_open(struct inode *inode, struct file *file,
216 			const struct seq_operations *ops, int psize)
217 {
218 	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
219 
220 	if (!priv)
221 		return -ENOMEM;
222 
223 	priv->inode = inode;
224 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
225 	if (IS_ERR(priv->mm)) {
226 		int err = PTR_ERR(priv->mm);
227 
228 		seq_release_private(inode, file);
229 		return err;
230 	}
231 
232 	return 0;
233 }
234 
proc_map_release(struct inode * inode,struct file * file)235 static int proc_map_release(struct inode *inode, struct file *file)
236 {
237 	struct seq_file *seq = file->private_data;
238 	struct proc_maps_private *priv = seq->private;
239 
240 	if (priv->mm)
241 		mmdrop(priv->mm);
242 
243 	return seq_release_private(inode, file);
244 }
245 
do_maps_open(struct inode * inode,struct file * file,const struct seq_operations * ops)246 static int do_maps_open(struct inode *inode, struct file *file,
247 			const struct seq_operations *ops)
248 {
249 	return proc_maps_open(inode, file, ops,
250 				sizeof(struct proc_maps_private));
251 }
252 
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)253 static void show_vma_header_prefix(struct seq_file *m,
254 				   unsigned long start, unsigned long end,
255 				   vm_flags_t flags, unsigned long long pgoff,
256 				   dev_t dev, unsigned long ino)
257 {
258 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
259 	seq_put_hex_ll(m, NULL, start, 8);
260 	seq_put_hex_ll(m, "-", end, 8);
261 	seq_putc(m, ' ');
262 	seq_putc(m, flags & VM_READ ? 'r' : '-');
263 	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
264 	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
265 	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
266 	seq_put_hex_ll(m, " ", pgoff, 8);
267 	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
268 	seq_put_hex_ll(m, ":", MINOR(dev), 2);
269 	seq_put_decimal_ull(m, " ", ino);
270 	seq_putc(m, ' ');
271 }
272 
273 static void
show_map_vma(struct seq_file * m,struct vm_area_struct * vma)274 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
275 {
276 	struct anon_vma_name *anon_name = NULL;
277 	struct mm_struct *mm = vma->vm_mm;
278 	struct file *file = vma->vm_file;
279 	vm_flags_t flags = vma->vm_flags;
280 	unsigned long ino = 0;
281 	unsigned long long pgoff = 0;
282 	unsigned long start, end;
283 	dev_t dev = 0;
284 	const char *name = NULL;
285 
286 	if (file) {
287 		struct inode *inode = file_inode(vma->vm_file);
288 		dev = inode->i_sb->s_dev;
289 		ino = inode->i_ino;
290 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
291 	}
292 
293 	start = vma->vm_start;
294 	end = vma->vm_end;
295 	CALL_HCK_LITE_HOOK(hideaddr_header_prefix_lhck, &start, &end, &flags, m, vma);
296 	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
297 	if (mm)
298 		anon_name = anon_vma_name(vma);
299 
300 	/*
301 	 * Print the dentry name for named mappings, and a
302 	 * special [heap] marker for the heap:
303 	 */
304 	if (file) {
305 		seq_pad(m, ' ');
306 		/*
307 		 * If user named this anon shared memory via
308 		 * prctl(PR_SET_VMA ..., use the provided name.
309 		 */
310 		if (anon_name)
311 			seq_printf(m, "[anon_shmem:%s]", anon_name->name);
312 		else
313 			seq_file_path(m, file, "\n");
314 		goto done;
315 	}
316 
317 	if (vma->vm_ops && vma->vm_ops->name) {
318 		name = vma->vm_ops->name(vma);
319 		if (name)
320 			goto done;
321 	}
322 
323 	name = arch_vma_name(vma);
324 	if (!name) {
325 		if (!mm) {
326 			name = "[vdso]";
327 			goto done;
328 		}
329 
330 		if (vma_is_initial_heap(vma)) {
331 			name = "[heap]";
332 			goto done;
333 		}
334 
335 		if (vma_is_initial_stack(vma)) {
336 			name = "[stack]";
337 			goto done;
338 		}
339 
340 		if (anon_name) {
341 			seq_pad(m, ' ');
342 			seq_printf(m, "[anon:%s]", anon_name->name);
343 		}
344 	}
345 
346 done:
347 	if (name) {
348 		seq_pad(m, ' ');
349 		seq_puts(m, name);
350 	}
351 	seq_putc(m, '\n');
352 }
353 
show_map(struct seq_file * m,void * v)354 static int show_map(struct seq_file *m, void *v)
355 {
356 	show_map_vma(m, v);
357 	return 0;
358 }
359 
360 static const struct seq_operations proc_pid_maps_op = {
361 	.start	= m_start,
362 	.next	= m_next,
363 	.stop	= m_stop,
364 	.show	= show_map
365 };
366 
pid_maps_open(struct inode * inode,struct file * file)367 static int pid_maps_open(struct inode *inode, struct file *file)
368 {
369 	return do_maps_open(inode, file, &proc_pid_maps_op);
370 }
371 
372 const struct file_operations proc_pid_maps_operations = {
373 	.open		= pid_maps_open,
374 	.read		= seq_read,
375 	.llseek		= seq_lseek,
376 	.release	= proc_map_release,
377 };
378 
379 /*
380  * Proportional Set Size(PSS): my share of RSS.
381  *
382  * PSS of a process is the count of pages it has in memory, where each
383  * page is divided by the number of processes sharing it.  So if a
384  * process has 1000 pages all to itself, and 1000 shared with one other
385  * process, its PSS will be 1500.
386  *
387  * To keep (accumulated) division errors low, we adopt a 64bit
388  * fixed-point pss counter to minimize division errors. So (pss >>
389  * PSS_SHIFT) would be the real byte count.
390  *
391  * A shift of 12 before division means (assuming 4K page size):
392  * 	- 1M 3-user-pages add up to 8KB errors;
393  * 	- supports mapcount up to 2^24, or 16M;
394  * 	- supports PSS up to 2^52 bytes, or 4PB.
395  */
396 #define PSS_SHIFT 12
397 
398 #ifdef CONFIG_PROC_PAGE_MONITOR
399 struct mem_size_stats {
400 	unsigned long resident;
401 	unsigned long shared_clean;
402 	unsigned long shared_dirty;
403 	unsigned long private_clean;
404 	unsigned long private_dirty;
405 	unsigned long referenced;
406 	unsigned long anonymous;
407 	unsigned long lazyfree;
408 	unsigned long anonymous_thp;
409 	unsigned long shmem_thp;
410 	unsigned long file_thp;
411 	unsigned long swap;
412 	unsigned long shared_hugetlb;
413 	unsigned long private_hugetlb;
414 	unsigned long ksm;
415 	u64 pss;
416 	u64 pss_anon;
417 	u64 pss_file;
418 	u64 pss_shmem;
419 	u64 pss_dirty;
420 	u64 pss_locked;
421 	u64 swap_pss;
422 };
423 
smaps_page_accumulate(struct mem_size_stats * mss,struct page * page,unsigned long size,unsigned long pss,bool dirty,bool locked,bool private)424 static void smaps_page_accumulate(struct mem_size_stats *mss,
425 		struct page *page, unsigned long size, unsigned long pss,
426 		bool dirty, bool locked, bool private)
427 {
428 	mss->pss += pss;
429 
430 	if (PageAnon(page))
431 		mss->pss_anon += pss;
432 	else if (PageSwapBacked(page))
433 		mss->pss_shmem += pss;
434 	else
435 		mss->pss_file += pss;
436 
437 	if (locked)
438 		mss->pss_locked += pss;
439 
440 	if (dirty || PageDirty(page)) {
441 		mss->pss_dirty += pss;
442 		if (private)
443 			mss->private_dirty += size;
444 		else
445 			mss->shared_dirty += size;
446 	} else {
447 		if (private)
448 			mss->private_clean += size;
449 		else
450 			mss->shared_clean += size;
451 	}
452 }
453 
smaps_account(struct mem_size_stats * mss,struct page * page,bool compound,bool young,bool dirty,bool locked,bool migration)454 static void smaps_account(struct mem_size_stats *mss, struct page *page,
455 		bool compound, bool young, bool dirty, bool locked,
456 		bool migration)
457 {
458 	int i, nr = compound ? compound_nr(page) : 1;
459 	unsigned long size = nr * PAGE_SIZE;
460 
461 	/*
462 	 * First accumulate quantities that depend only on |size| and the type
463 	 * of the compound page.
464 	 */
465 	if (PageAnon(page)) {
466 		mss->anonymous += size;
467 		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
468 			mss->lazyfree += size;
469 	}
470 
471 	if (PageKsm(page))
472 		mss->ksm += size;
473 
474 	mss->resident += size;
475 	/* Accumulate the size in pages that have been accessed. */
476 	if (young || page_is_young(page) || PageReferenced(page))
477 		mss->referenced += size;
478 
479 	/*
480 	 * Then accumulate quantities that may depend on sharing, or that may
481 	 * differ page-by-page.
482 	 *
483 	 * page_count(page) == 1 guarantees the page is mapped exactly once.
484 	 * If any subpage of the compound page mapped with PTE it would elevate
485 	 * page_count().
486 	 *
487 	 * The page_mapcount() is called to get a snapshot of the mapcount.
488 	 * Without holding the page lock this snapshot can be slightly wrong as
489 	 * we cannot always read the mapcount atomically.  It is not safe to
490 	 * call page_mapcount() even with PTL held if the page is not mapped,
491 	 * especially for migration entries.  Treat regular migration entries
492 	 * as mapcount == 1.
493 	 */
494 	if ((page_count(page) == 1) || migration) {
495 		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
496 			locked, true);
497 		return;
498 	}
499 	for (i = 0; i < nr; i++, page++) {
500 		int mapcount = page_mapcount(page);
501 		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
502 		if (mapcount >= 2)
503 			pss /= mapcount;
504 		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
505 				      mapcount < 2);
506 	}
507 }
508 
509 #ifdef CONFIG_SHMEM
smaps_pte_hole(unsigned long addr,unsigned long end,__always_unused int depth,struct mm_walk * walk)510 static int smaps_pte_hole(unsigned long addr, unsigned long end,
511 			  __always_unused int depth, struct mm_walk *walk)
512 {
513 	struct mem_size_stats *mss = walk->private;
514 	struct vm_area_struct *vma = walk->vma;
515 
516 	mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
517 					      linear_page_index(vma, addr),
518 					      linear_page_index(vma, end));
519 
520 	return 0;
521 }
522 #else
523 #define smaps_pte_hole		NULL
524 #endif /* CONFIG_SHMEM */
525 
smaps_pte_hole_lookup(unsigned long addr,struct mm_walk * walk)526 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
527 {
528 #ifdef CONFIG_SHMEM
529 	if (walk->ops->pte_hole) {
530 		/* depth is not used */
531 		smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
532 	}
533 #endif
534 }
535 
smaps_pte_entry(pte_t * pte,unsigned long addr,struct mm_walk * walk)536 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
537 		struct mm_walk *walk)
538 {
539 	struct mem_size_stats *mss = walk->private;
540 	struct vm_area_struct *vma = walk->vma;
541 	bool locked = !!(vma->vm_flags & VM_LOCKED);
542 	struct page *page = NULL;
543 	bool migration = false, young = false, dirty = false;
544 	pte_t ptent = ptep_get(pte);
545 
546 	if (pte_present(ptent)) {
547 		page = vm_normal_page(vma, addr, ptent);
548 		young = pte_young(ptent);
549 		dirty = pte_dirty(ptent);
550 	} else if (is_swap_pte(ptent)) {
551 		swp_entry_t swpent = pte_to_swp_entry(ptent);
552 
553 		if (!non_swap_entry(swpent)) {
554 			int mapcount;
555 
556 			mss->swap += PAGE_SIZE;
557 			mapcount = swp_swapcount(swpent);
558 			if (mapcount >= 2) {
559 				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
560 
561 				do_div(pss_delta, mapcount);
562 				mss->swap_pss += pss_delta;
563 			} else {
564 				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
565 			}
566 		} else if (is_pfn_swap_entry(swpent)) {
567 			if (is_migration_entry(swpent))
568 				migration = true;
569 			page = pfn_swap_entry_to_page(swpent);
570 		}
571 	} else {
572 		smaps_pte_hole_lookup(addr, walk);
573 		return;
574 	}
575 
576 	if (!page)
577 		return;
578 
579 	smaps_account(mss, page, false, young, dirty, locked, migration);
580 }
581 
582 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
smaps_pmd_entry(pmd_t * pmd,unsigned long addr,struct mm_walk * walk)583 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
584 		struct mm_walk *walk)
585 {
586 	struct mem_size_stats *mss = walk->private;
587 	struct vm_area_struct *vma = walk->vma;
588 	bool locked = !!(vma->vm_flags & VM_LOCKED);
589 	struct page *page = NULL;
590 	bool migration = false;
591 
592 	if (pmd_present(*pmd)) {
593 		page = vm_normal_page_pmd(vma, addr, *pmd);
594 	} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
595 		swp_entry_t entry = pmd_to_swp_entry(*pmd);
596 
597 		if (is_migration_entry(entry)) {
598 			migration = true;
599 			page = pfn_swap_entry_to_page(entry);
600 		}
601 	}
602 	if (IS_ERR_OR_NULL(page))
603 		return;
604 	if (PageAnon(page))
605 		mss->anonymous_thp += HPAGE_PMD_SIZE;
606 	else if (PageSwapBacked(page))
607 		mss->shmem_thp += HPAGE_PMD_SIZE;
608 	else if (is_zone_device_page(page))
609 		/* pass */;
610 	else
611 		mss->file_thp += HPAGE_PMD_SIZE;
612 
613 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
614 		      locked, migration);
615 }
616 #else
smaps_pmd_entry(pmd_t * pmd,unsigned long addr,struct mm_walk * walk)617 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
618 		struct mm_walk *walk)
619 {
620 }
621 #endif
622 
smaps_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)623 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
624 			   struct mm_walk *walk)
625 {
626 	struct vm_area_struct *vma = walk->vma;
627 	pte_t *pte;
628 	spinlock_t *ptl;
629 
630 	ptl = pmd_trans_huge_lock(pmd, vma);
631 	if (ptl) {
632 		smaps_pmd_entry(pmd, addr, walk);
633 		spin_unlock(ptl);
634 		goto out;
635 	}
636 
637 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
638 	if (!pte) {
639 		walk->action = ACTION_AGAIN;
640 		return 0;
641 	}
642 	for (; addr != end; pte++, addr += PAGE_SIZE)
643 		smaps_pte_entry(pte, addr, walk);
644 	pte_unmap_unlock(pte - 1, ptl);
645 out:
646 	cond_resched();
647 	return 0;
648 }
649 
show_smap_vma_flags(struct seq_file * m,struct vm_area_struct * vma)650 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
651 {
652 	/*
653 	 * Don't forget to update Documentation/ on changes.
654 	 */
655 	static const char mnemonics[BITS_PER_LONG][2] = {
656 		/*
657 		 * In case if we meet a flag we don't know about.
658 		 */
659 		[0 ... (BITS_PER_LONG-1)] = "??",
660 
661 		[ilog2(VM_READ)]	= "rd",
662 		[ilog2(VM_WRITE)]	= "wr",
663 		[ilog2(VM_EXEC)]	= "ex",
664 		[ilog2(VM_SHARED)]	= "sh",
665 		[ilog2(VM_MAYREAD)]	= "mr",
666 		[ilog2(VM_MAYWRITE)]	= "mw",
667 		[ilog2(VM_MAYEXEC)]	= "me",
668 		[ilog2(VM_MAYSHARE)]	= "ms",
669 		[ilog2(VM_GROWSDOWN)]	= "gd",
670 		[ilog2(VM_PFNMAP)]	= "pf",
671 		[ilog2(VM_LOCKED)]	= "lo",
672 		[ilog2(VM_IO)]		= "io",
673 		[ilog2(VM_SEQ_READ)]	= "sr",
674 		[ilog2(VM_RAND_READ)]	= "rr",
675 		[ilog2(VM_DONTCOPY)]	= "dc",
676 		[ilog2(VM_DONTEXPAND)]	= "de",
677 		[ilog2(VM_LOCKONFAULT)]	= "lf",
678 		[ilog2(VM_ACCOUNT)]	= "ac",
679 		[ilog2(VM_NORESERVE)]	= "nr",
680 		[ilog2(VM_HUGETLB)]	= "ht",
681 		[ilog2(VM_SYNC)]	= "sf",
682 		[ilog2(VM_ARCH_1)]	= "ar",
683 		[ilog2(VM_WIPEONFORK)]	= "wf",
684 		[ilog2(VM_DONTDUMP)]	= "dd",
685 #ifdef CONFIG_ARM64_BTI
686 		[ilog2(VM_ARM64_BTI)]	= "bt",
687 #endif
688 #ifdef CONFIG_MEM_SOFT_DIRTY
689 		[ilog2(VM_SOFTDIRTY)]	= "sd",
690 #endif
691 		[ilog2(VM_MIXEDMAP)]	= "mm",
692 		[ilog2(VM_HUGEPAGE)]	= "hg",
693 		[ilog2(VM_NOHUGEPAGE)]	= "nh",
694 		[ilog2(VM_MERGEABLE)]	= "mg",
695 		[ilog2(VM_UFFD_MISSING)]= "um",
696 		[ilog2(VM_UFFD_WP)]	= "uw",
697 #ifdef CONFIG_ARM64_MTE
698 		[ilog2(VM_MTE)]		= "mt",
699 		[ilog2(VM_MTE_ALLOWED)]	= "",
700 #endif
701 #ifdef CONFIG_ARCH_HAS_PKEYS
702 		/* These come out via ProtectionKey: */
703 		[ilog2(VM_PKEY_BIT0)]	= "",
704 		[ilog2(VM_PKEY_BIT1)]	= "",
705 		[ilog2(VM_PKEY_BIT2)]	= "",
706 		[ilog2(VM_PKEY_BIT3)]	= "",
707 #if VM_PKEY_BIT4
708 		[ilog2(VM_PKEY_BIT4)]	= "",
709 #endif
710 #endif /* CONFIG_ARCH_HAS_PKEYS */
711 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
712 		[ilog2(VM_UFFD_MINOR)]	= "ui",
713 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
714 #ifdef CONFIG_X86_USER_SHADOW_STACK
715 		[ilog2(VM_SHADOW_STACK)] = "ss",
716 #endif
717 	};
718 	size_t i;
719 
720 	seq_puts(m, "VmFlags: ");
721 	for (i = 0; i < BITS_PER_LONG; i++) {
722 		if (!mnemonics[i][0])
723 			continue;
724 		if (vma->vm_flags & (1UL << i)) {
725 			seq_putc(m, mnemonics[i][0]);
726 			seq_putc(m, mnemonics[i][1]);
727 			seq_putc(m, ' ');
728 		}
729 	}
730 	seq_putc(m, '\n');
731 }
732 
733 #ifdef CONFIG_HUGETLB_PAGE
smaps_hugetlb_range(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)734 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
735 				 unsigned long addr, unsigned long end,
736 				 struct mm_walk *walk)
737 {
738 	struct mem_size_stats *mss = walk->private;
739 	struct vm_area_struct *vma = walk->vma;
740 	struct page *page = NULL;
741 	pte_t ptent = ptep_get(pte);
742 
743 	if (pte_present(ptent)) {
744 		page = vm_normal_page(vma, addr, ptent);
745 	} else if (is_swap_pte(ptent)) {
746 		swp_entry_t swpent = pte_to_swp_entry(ptent);
747 
748 		if (is_pfn_swap_entry(swpent))
749 			page = pfn_swap_entry_to_page(swpent);
750 	}
751 	if (page) {
752 		if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
753 			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
754 		else
755 			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
756 	}
757 	return 0;
758 }
759 #else
760 #define smaps_hugetlb_range	NULL
761 #endif /* HUGETLB_PAGE */
762 
763 static const struct mm_walk_ops smaps_walk_ops = {
764 	.pmd_entry		= smaps_pte_range,
765 	.hugetlb_entry		= smaps_hugetlb_range,
766 	.walk_lock		= PGWALK_RDLOCK,
767 };
768 
769 static const struct mm_walk_ops smaps_shmem_walk_ops = {
770 	.pmd_entry		= smaps_pte_range,
771 	.hugetlb_entry		= smaps_hugetlb_range,
772 	.pte_hole		= smaps_pte_hole,
773 	.walk_lock		= PGWALK_RDLOCK,
774 };
775 
776 /*
777  * Gather mem stats from @vma with the indicated beginning
778  * address @start, and keep them in @mss.
779  *
780  * Use vm_start of @vma as the beginning address if @start is 0.
781  */
smap_gather_stats(struct vm_area_struct * vma,struct mem_size_stats * mss,unsigned long start)782 static void smap_gather_stats(struct vm_area_struct *vma,
783 		struct mem_size_stats *mss, unsigned long start)
784 {
785 	const struct mm_walk_ops *ops = &smaps_walk_ops;
786 
787 	/* Invalid start */
788 	if (start >= vma->vm_end)
789 		return;
790 
791 	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
792 		/*
793 		 * For shared or readonly shmem mappings we know that all
794 		 * swapped out pages belong to the shmem object, and we can
795 		 * obtain the swap value much more efficiently. For private
796 		 * writable mappings, we might have COW pages that are
797 		 * not affected by the parent swapped out pages of the shmem
798 		 * object, so we have to distinguish them during the page walk.
799 		 * Unless we know that the shmem object (or the part mapped by
800 		 * our VMA) has no swapped out pages at all.
801 		 */
802 		unsigned long shmem_swapped = shmem_swap_usage(vma);
803 
804 		if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
805 					!(vma->vm_flags & VM_WRITE))) {
806 			mss->swap += shmem_swapped;
807 		} else {
808 			ops = &smaps_shmem_walk_ops;
809 		}
810 	}
811 
812 	/* mmap_lock is held in m_start */
813 	if (!start)
814 		walk_page_vma(vma, ops, mss);
815 	else
816 		walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
817 }
818 
819 #define SEQ_PUT_DEC(str, val) \
820 		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
821 
822 /* Show the contents common for smaps and smaps_rollup */
__show_smap(struct seq_file * m,const struct mem_size_stats * mss,bool rollup_mode)823 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
824 	bool rollup_mode)
825 {
826 	SEQ_PUT_DEC("Rss:            ", mss->resident);
827 	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
828 	SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> PSS_SHIFT);
829 	if (rollup_mode) {
830 		/*
831 		 * These are meaningful only for smaps_rollup, otherwise two of
832 		 * them are zero, and the other one is the same as Pss.
833 		 */
834 		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
835 			mss->pss_anon >> PSS_SHIFT);
836 		SEQ_PUT_DEC(" kB\nPss_File:       ",
837 			mss->pss_file >> PSS_SHIFT);
838 		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
839 			mss->pss_shmem >> PSS_SHIFT);
840 	}
841 	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
842 	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
843 	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
844 	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
845 	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
846 	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
847 	SEQ_PUT_DEC(" kB\nKSM:            ", mss->ksm);
848 	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
849 	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
850 	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
851 	SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
852 	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
853 	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
854 				  mss->private_hugetlb >> 10, 7);
855 	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
856 	SEQ_PUT_DEC(" kB\nSwapPss:        ",
857 					mss->swap_pss >> PSS_SHIFT);
858 	SEQ_PUT_DEC(" kB\nLocked:         ",
859 					mss->pss_locked >> PSS_SHIFT);
860 	seq_puts(m, " kB\n");
861 }
862 
show_smap(struct seq_file * m,void * v)863 static int show_smap(struct seq_file *m, void *v)
864 {
865 	struct vm_area_struct *vma = v;
866 	struct mem_size_stats mss;
867 
868 	memset(&mss, 0, sizeof(mss));
869 
870 	smap_gather_stats(vma, &mss, 0);
871 
872 	show_map_vma(m, vma);
873 
874 	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
875 	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
876 	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
877 	seq_puts(m, " kB\n");
878 
879 	__show_smap(m, &mss, false);
880 
881 	seq_printf(m, "THPeligible:    %8u\n",
882 		   hugepage_vma_check(vma, vma->vm_flags, true, false, true));
883 
884 	if (arch_pkeys_enabled())
885 		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
886 	show_smap_vma_flags(m, vma);
887 
888 	return 0;
889 }
890 
show_smaps_rollup(struct seq_file * m,void * v)891 static int show_smaps_rollup(struct seq_file *m, void *v)
892 {
893 	struct proc_maps_private *priv = m->private;
894 	struct mem_size_stats mss;
895 	struct mm_struct *mm = priv->mm;
896 	struct vm_area_struct *vma;
897 	unsigned long vma_start = 0, last_vma_end = 0;
898 	int ret = 0;
899 	VMA_ITERATOR(vmi, mm, 0);
900 
901 	priv->task = get_proc_task(priv->inode);
902 	if (!priv->task)
903 		return -ESRCH;
904 
905 	if (!mm || !mmget_not_zero(mm)) {
906 		ret = -ESRCH;
907 		goto out_put_task;
908 	}
909 
910 	memset(&mss, 0, sizeof(mss));
911 
912 	ret = mmap_read_lock_killable(mm);
913 	if (ret)
914 		goto out_put_mm;
915 
916 	hold_task_mempolicy(priv);
917 	vma = vma_next(&vmi);
918 
919 	if (unlikely(!vma))
920 		goto empty_set;
921 
922 	vma_start = vma->vm_start;
923 	do {
924 		smap_gather_stats(vma, &mss, 0);
925 		last_vma_end = vma->vm_end;
926 
927 		/*
928 		 * Release mmap_lock temporarily if someone wants to
929 		 * access it for write request.
930 		 */
931 		if (mmap_lock_is_contended(mm)) {
932 			vma_iter_invalidate(&vmi);
933 			mmap_read_unlock(mm);
934 			ret = mmap_read_lock_killable(mm);
935 			if (ret) {
936 				release_task_mempolicy(priv);
937 				goto out_put_mm;
938 			}
939 
940 			/*
941 			 * After dropping the lock, there are four cases to
942 			 * consider. See the following example for explanation.
943 			 *
944 			 *   +------+------+-----------+
945 			 *   | VMA1 | VMA2 | VMA3      |
946 			 *   +------+------+-----------+
947 			 *   |      |      |           |
948 			 *  4k     8k     16k         400k
949 			 *
950 			 * Suppose we drop the lock after reading VMA2 due to
951 			 * contention, then we get:
952 			 *
953 			 *	last_vma_end = 16k
954 			 *
955 			 * 1) VMA2 is freed, but VMA3 exists:
956 			 *
957 			 *    vma_next(vmi) will return VMA3.
958 			 *    In this case, just continue from VMA3.
959 			 *
960 			 * 2) VMA2 still exists:
961 			 *
962 			 *    vma_next(vmi) will return VMA3.
963 			 *    In this case, just continue from VMA3.
964 			 *
965 			 * 3) No more VMAs can be found:
966 			 *
967 			 *    vma_next(vmi) will return NULL.
968 			 *    No more things to do, just break.
969 			 *
970 			 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
971 			 *
972 			 *    vma_next(vmi) will return VMA' whose range
973 			 *    contains last_vma_end.
974 			 *    Iterate VMA' from last_vma_end.
975 			 */
976 			vma = vma_next(&vmi);
977 			/* Case 3 above */
978 			if (!vma)
979 				break;
980 
981 			/* Case 1 and 2 above */
982 			if (vma->vm_start >= last_vma_end) {
983 				smap_gather_stats(vma, &mss, 0);
984 				last_vma_end = vma->vm_end;
985 				continue;
986 			}
987 
988 			/* Case 4 above */
989 			if (vma->vm_end > last_vma_end) {
990 				smap_gather_stats(vma, &mss, last_vma_end);
991 				last_vma_end = vma->vm_end;
992 			}
993 		}
994 	} for_each_vma(vmi, vma);
995 
996 empty_set:
997 	show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
998 	seq_pad(m, ' ');
999 	seq_puts(m, "[rollup]\n");
1000 
1001 	__show_smap(m, &mss, true);
1002 
1003 	release_task_mempolicy(priv);
1004 	mmap_read_unlock(mm);
1005 
1006 out_put_mm:
1007 	mmput(mm);
1008 out_put_task:
1009 	put_task_struct(priv->task);
1010 	priv->task = NULL;
1011 
1012 	return ret;
1013 }
1014 #undef SEQ_PUT_DEC
1015 
1016 static const struct seq_operations proc_pid_smaps_op = {
1017 	.start	= m_start,
1018 	.next	= m_next,
1019 	.stop	= m_stop,
1020 	.show	= show_smap
1021 };
1022 
pid_smaps_open(struct inode * inode,struct file * file)1023 static int pid_smaps_open(struct inode *inode, struct file *file)
1024 {
1025 	return do_maps_open(inode, file, &proc_pid_smaps_op);
1026 }
1027 
smaps_rollup_open(struct inode * inode,struct file * file)1028 static int smaps_rollup_open(struct inode *inode, struct file *file)
1029 {
1030 	int ret;
1031 	struct proc_maps_private *priv;
1032 
1033 	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1034 	if (!priv)
1035 		return -ENOMEM;
1036 
1037 	ret = single_open(file, show_smaps_rollup, priv);
1038 	if (ret)
1039 		goto out_free;
1040 
1041 	priv->inode = inode;
1042 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1043 	if (IS_ERR(priv->mm)) {
1044 		ret = PTR_ERR(priv->mm);
1045 
1046 		single_release(inode, file);
1047 		goto out_free;
1048 	}
1049 
1050 	return 0;
1051 
1052 out_free:
1053 	kfree(priv);
1054 	return ret;
1055 }
1056 
smaps_rollup_release(struct inode * inode,struct file * file)1057 static int smaps_rollup_release(struct inode *inode, struct file *file)
1058 {
1059 	struct seq_file *seq = file->private_data;
1060 	struct proc_maps_private *priv = seq->private;
1061 
1062 	if (priv->mm)
1063 		mmdrop(priv->mm);
1064 
1065 	kfree(priv);
1066 	return single_release(inode, file);
1067 }
1068 
1069 const struct file_operations proc_pid_smaps_operations = {
1070 	.open		= pid_smaps_open,
1071 	.read		= seq_read,
1072 	.llseek		= seq_lseek,
1073 	.release	= proc_map_release,
1074 };
1075 
1076 const struct file_operations proc_pid_smaps_rollup_operations = {
1077 	.open		= smaps_rollup_open,
1078 	.read		= seq_read,
1079 	.llseek		= seq_lseek,
1080 	.release	= smaps_rollup_release,
1081 };
1082 
1083 enum clear_refs_types {
1084 	CLEAR_REFS_ALL = 1,
1085 	CLEAR_REFS_ANON,
1086 	CLEAR_REFS_MAPPED,
1087 	CLEAR_REFS_SOFT_DIRTY,
1088 	CLEAR_REFS_MM_HIWATER_RSS,
1089 	CLEAR_REFS_LAST,
1090 };
1091 
1092 struct clear_refs_private {
1093 	enum clear_refs_types type;
1094 };
1095 
1096 #ifdef CONFIG_MEM_SOFT_DIRTY
1097 
pte_is_pinned(struct vm_area_struct * vma,unsigned long addr,pte_t pte)1098 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1099 {
1100 	struct page *page;
1101 
1102 	if (!pte_write(pte))
1103 		return false;
1104 	if (!is_cow_mapping(vma->vm_flags))
1105 		return false;
1106 	if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1107 		return false;
1108 	page = vm_normal_page(vma, addr, pte);
1109 	if (!page)
1110 		return false;
1111 	return page_maybe_dma_pinned(page);
1112 }
1113 
clear_soft_dirty(struct vm_area_struct * vma,unsigned long addr,pte_t * pte)1114 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1115 		unsigned long addr, pte_t *pte)
1116 {
1117 	/*
1118 	 * The soft-dirty tracker uses #PF-s to catch writes
1119 	 * to pages, so write-protect the pte as well. See the
1120 	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
1121 	 * of how soft-dirty works.
1122 	 */
1123 	pte_t ptent = ptep_get(pte);
1124 
1125 	if (pte_present(ptent)) {
1126 		pte_t old_pte;
1127 
1128 		if (pte_is_pinned(vma, addr, ptent))
1129 			return;
1130 		old_pte = ptep_modify_prot_start(vma, addr, pte);
1131 		ptent = pte_wrprotect(old_pte);
1132 		ptent = pte_clear_soft_dirty(ptent);
1133 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1134 	} else if (is_swap_pte(ptent)) {
1135 		ptent = pte_swp_clear_soft_dirty(ptent);
1136 		set_pte_at(vma->vm_mm, addr, pte, ptent);
1137 	}
1138 }
1139 #else
clear_soft_dirty(struct vm_area_struct * vma,unsigned long addr,pte_t * pte)1140 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1141 		unsigned long addr, pte_t *pte)
1142 {
1143 }
1144 #endif
1145 
1146 #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)1147 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1148 		unsigned long addr, pmd_t *pmdp)
1149 {
1150 	pmd_t old, pmd = *pmdp;
1151 
1152 	if (pmd_present(pmd)) {
1153 		/* See comment in change_huge_pmd() */
1154 		old = pmdp_invalidate(vma, addr, pmdp);
1155 		if (pmd_dirty(old))
1156 			pmd = pmd_mkdirty(pmd);
1157 		if (pmd_young(old))
1158 			pmd = pmd_mkyoung(pmd);
1159 
1160 		pmd = pmd_wrprotect(pmd);
1161 		pmd = pmd_clear_soft_dirty(pmd);
1162 
1163 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1164 	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1165 		pmd = pmd_swp_clear_soft_dirty(pmd);
1166 		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1167 	}
1168 }
1169 #else
clear_soft_dirty_pmd(struct vm_area_struct * vma,unsigned long addr,pmd_t * pmdp)1170 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1171 		unsigned long addr, pmd_t *pmdp)
1172 {
1173 }
1174 #endif
1175 
clear_refs_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)1176 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1177 				unsigned long end, struct mm_walk *walk)
1178 {
1179 	struct clear_refs_private *cp = walk->private;
1180 	struct vm_area_struct *vma = walk->vma;
1181 	pte_t *pte, ptent;
1182 	spinlock_t *ptl;
1183 	struct page *page;
1184 
1185 	ptl = pmd_trans_huge_lock(pmd, vma);
1186 	if (ptl) {
1187 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1188 			clear_soft_dirty_pmd(vma, addr, pmd);
1189 			goto out;
1190 		}
1191 
1192 		if (!pmd_present(*pmd))
1193 			goto out;
1194 
1195 		page = pmd_page(*pmd);
1196 
1197 		/* Clear accessed and referenced bits. */
1198 		pmdp_test_and_clear_young(vma, addr, pmd);
1199 		test_and_clear_page_young(page);
1200 		ClearPageReferenced(page);
1201 out:
1202 		spin_unlock(ptl);
1203 		return 0;
1204 	}
1205 
1206 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1207 	if (!pte) {
1208 		walk->action = ACTION_AGAIN;
1209 		return 0;
1210 	}
1211 	for (; addr != end; pte++, addr += PAGE_SIZE) {
1212 		ptent = ptep_get(pte);
1213 
1214 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1215 			clear_soft_dirty(vma, addr, pte);
1216 			continue;
1217 		}
1218 
1219 		if (!pte_present(ptent))
1220 			continue;
1221 
1222 		page = vm_normal_page(vma, addr, ptent);
1223 		if (!page)
1224 			continue;
1225 
1226 		/* Clear accessed and referenced bits. */
1227 		ptep_test_and_clear_young(vma, addr, pte);
1228 		test_and_clear_page_young(page);
1229 		ClearPageReferenced(page);
1230 	}
1231 	pte_unmap_unlock(pte - 1, ptl);
1232 	cond_resched();
1233 	return 0;
1234 }
1235 
clear_refs_test_walk(unsigned long start,unsigned long end,struct mm_walk * walk)1236 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1237 				struct mm_walk *walk)
1238 {
1239 	struct clear_refs_private *cp = walk->private;
1240 	struct vm_area_struct *vma = walk->vma;
1241 
1242 	if (vma->vm_flags & VM_PFNMAP)
1243 		return 1;
1244 
1245 	/*
1246 	 * Writing 1 to /proc/pid/clear_refs affects all pages.
1247 	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1248 	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1249 	 * Writing 4 to /proc/pid/clear_refs affects all pages.
1250 	 */
1251 	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1252 		return 1;
1253 	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1254 		return 1;
1255 	return 0;
1256 }
1257 
1258 static const struct mm_walk_ops clear_refs_walk_ops = {
1259 	.pmd_entry		= clear_refs_pte_range,
1260 	.test_walk		= clear_refs_test_walk,
1261 	.walk_lock		= PGWALK_WRLOCK,
1262 };
1263 
clear_refs_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1264 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1265 				size_t count, loff_t *ppos)
1266 {
1267 	struct task_struct *task;
1268 	char buffer[PROC_NUMBUF];
1269 	struct mm_struct *mm;
1270 	struct vm_area_struct *vma;
1271 	enum clear_refs_types type;
1272 	int itype;
1273 	int rv;
1274 
1275 	memset(buffer, 0, sizeof(buffer));
1276 	if (count > sizeof(buffer) - 1)
1277 		count = sizeof(buffer) - 1;
1278 	if (copy_from_user(buffer, buf, count))
1279 		return -EFAULT;
1280 	rv = kstrtoint(strstrip(buffer), 10, &itype);
1281 	if (rv < 0)
1282 		return rv;
1283 	type = (enum clear_refs_types)itype;
1284 	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1285 		return -EINVAL;
1286 
1287 	task = get_proc_task(file_inode(file));
1288 	if (!task)
1289 		return -ESRCH;
1290 	mm = get_task_mm(task);
1291 	if (mm) {
1292 		VMA_ITERATOR(vmi, mm, 0);
1293 		struct mmu_notifier_range range;
1294 		struct clear_refs_private cp = {
1295 			.type = type,
1296 		};
1297 
1298 		if (mmap_write_lock_killable(mm)) {
1299 			count = -EINTR;
1300 			goto out_mm;
1301 		}
1302 		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1303 			/*
1304 			 * Writing 5 to /proc/pid/clear_refs resets the peak
1305 			 * resident set size to this mm's current rss value.
1306 			 */
1307 			reset_mm_hiwater_rss(mm);
1308 			goto out_unlock;
1309 		}
1310 
1311 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1312 			for_each_vma(vmi, vma) {
1313 				if (!(vma->vm_flags & VM_SOFTDIRTY))
1314 					continue;
1315 				vm_flags_clear(vma, VM_SOFTDIRTY);
1316 				vma_set_page_prot(vma);
1317 			}
1318 
1319 			inc_tlb_flush_pending(mm);
1320 			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1321 						0, mm, 0, -1UL);
1322 			mmu_notifier_invalidate_range_start(&range);
1323 		}
1324 		walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
1325 		if (type == CLEAR_REFS_SOFT_DIRTY) {
1326 			mmu_notifier_invalidate_range_end(&range);
1327 			flush_tlb_mm(mm);
1328 			dec_tlb_flush_pending(mm);
1329 		}
1330 out_unlock:
1331 		mmap_write_unlock(mm);
1332 out_mm:
1333 		mmput(mm);
1334 	}
1335 	put_task_struct(task);
1336 
1337 	return count;
1338 }
1339 
1340 const struct file_operations proc_clear_refs_operations = {
1341 	.write		= clear_refs_write,
1342 	.llseek		= noop_llseek,
1343 };
1344 
1345 typedef struct {
1346 	u64 pme;
1347 } pagemap_entry_t;
1348 
1349 struct pagemapread {
1350 	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
1351 	pagemap_entry_t *buffer;
1352 	bool show_pfn;
1353 };
1354 
1355 #define PAGEMAP_WALK_SIZE	(PMD_SIZE)
1356 #define PAGEMAP_WALK_MASK	(PMD_MASK)
1357 
1358 #define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
1359 #define PM_PFRAME_BITS		55
1360 #define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1361 #define PM_SOFT_DIRTY		BIT_ULL(55)
1362 #define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
1363 #define PM_UFFD_WP		BIT_ULL(57)
1364 #define PM_FILE			BIT_ULL(61)
1365 #define PM_SWAP			BIT_ULL(62)
1366 #define PM_PRESENT		BIT_ULL(63)
1367 
1368 #define PM_END_OF_BUFFER    1
1369 
make_pme(u64 frame,u64 flags)1370 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1371 {
1372 	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1373 }
1374 
add_to_pagemap(pagemap_entry_t * pme,struct pagemapread * pm)1375 static int add_to_pagemap(pagemap_entry_t *pme, struct pagemapread *pm)
1376 {
1377 	pm->buffer[pm->pos++] = *pme;
1378 	if (pm->pos >= pm->len)
1379 		return PM_END_OF_BUFFER;
1380 	return 0;
1381 }
1382 
pagemap_pte_hole(unsigned long start,unsigned long end,__always_unused int depth,struct mm_walk * walk)1383 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1384 			    __always_unused int depth, struct mm_walk *walk)
1385 {
1386 	struct pagemapread *pm = walk->private;
1387 	unsigned long addr = start;
1388 	int err = 0;
1389 
1390 	while (addr < end) {
1391 		struct vm_area_struct *vma = find_vma(walk->mm, addr);
1392 		pagemap_entry_t pme = make_pme(0, 0);
1393 		/* End of address space hole, which we mark as non-present. */
1394 		unsigned long hole_end;
1395 
1396 		if (vma)
1397 			hole_end = min(end, vma->vm_start);
1398 		else
1399 			hole_end = end;
1400 
1401 		for (; addr < hole_end; addr += PAGE_SIZE) {
1402 			err = add_to_pagemap(&pme, pm);
1403 			if (err)
1404 				goto out;
1405 		}
1406 
1407 		if (!vma)
1408 			break;
1409 
1410 		/* Addresses in the VMA. */
1411 		if (vma->vm_flags & VM_SOFTDIRTY)
1412 			pme = make_pme(0, PM_SOFT_DIRTY);
1413 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1414 			err = add_to_pagemap(&pme, pm);
1415 			if (err)
1416 				goto out;
1417 		}
1418 	}
1419 out:
1420 	return err;
1421 }
1422 
pte_to_pagemap_entry(struct pagemapread * pm,struct vm_area_struct * vma,unsigned long addr,pte_t pte)1423 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1424 		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1425 {
1426 	u64 frame = 0, flags = 0;
1427 	struct page *page = NULL;
1428 
1429 	if (pte_present(pte)) {
1430 		if (pm->show_pfn)
1431 			frame = pte_pfn(pte);
1432 		flags |= PM_PRESENT;
1433 		page = vm_normal_page(vma, addr, pte);
1434 		if (pte_soft_dirty(pte))
1435 			flags |= PM_SOFT_DIRTY;
1436 		if (pte_uffd_wp(pte))
1437 			flags |= PM_UFFD_WP;
1438 	} else if (is_swap_pte(pte)) {
1439 		swp_entry_t entry;
1440 		if (pte_swp_soft_dirty(pte))
1441 			flags |= PM_SOFT_DIRTY;
1442 		if (pte_swp_uffd_wp(pte))
1443 			flags |= PM_UFFD_WP;
1444 		entry = pte_to_swp_entry(pte);
1445 		if (pm->show_pfn) {
1446 			pgoff_t offset;
1447 			/*
1448 			 * For PFN swap offsets, keeping the offset field
1449 			 * to be PFN only to be compatible with old smaps.
1450 			 */
1451 			if (is_pfn_swap_entry(entry))
1452 				offset = swp_offset_pfn(entry);
1453 			else
1454 				offset = swp_offset(entry);
1455 			frame = swp_type(entry) |
1456 			    (offset << MAX_SWAPFILES_SHIFT);
1457 		}
1458 		flags |= PM_SWAP;
1459 		if (is_pfn_swap_entry(entry))
1460 			page = pfn_swap_entry_to_page(entry);
1461 		if (pte_marker_entry_uffd_wp(entry))
1462 			flags |= PM_UFFD_WP;
1463 	}
1464 
1465 	if (page && !PageAnon(page))
1466 		flags |= PM_FILE;
1467 	if (page && (flags & PM_PRESENT) && page_mapcount(page) == 1)
1468 		flags |= PM_MMAP_EXCLUSIVE;
1469 	if (vma->vm_flags & VM_SOFTDIRTY)
1470 		flags |= PM_SOFT_DIRTY;
1471 
1472 	return make_pme(frame, flags);
1473 }
1474 
pagemap_pmd_range(pmd_t * pmdp,unsigned long addr,unsigned long end,struct mm_walk * walk)1475 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1476 			     struct mm_walk *walk)
1477 {
1478 	struct vm_area_struct *vma = walk->vma;
1479 	struct pagemapread *pm = walk->private;
1480 	spinlock_t *ptl;
1481 	pte_t *pte, *orig_pte;
1482 	int err = 0;
1483 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1484 
1485 	ptl = pmd_trans_huge_lock(pmdp, vma);
1486 	if (ptl) {
1487 		unsigned int idx = (addr & ~PMD_MASK) >> PAGE_SHIFT;
1488 		u64 flags = 0, frame = 0;
1489 		pmd_t pmd = *pmdp;
1490 		struct page *page = NULL;
1491 
1492 		if (vma->vm_flags & VM_SOFTDIRTY)
1493 			flags |= PM_SOFT_DIRTY;
1494 
1495 		if (pmd_present(pmd)) {
1496 			page = pmd_page(pmd);
1497 
1498 			flags |= PM_PRESENT;
1499 			if (pmd_soft_dirty(pmd))
1500 				flags |= PM_SOFT_DIRTY;
1501 			if (pmd_uffd_wp(pmd))
1502 				flags |= PM_UFFD_WP;
1503 			if (pm->show_pfn)
1504 				frame = pmd_pfn(pmd) + idx;
1505 		}
1506 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1507 		else if (is_swap_pmd(pmd)) {
1508 			swp_entry_t entry = pmd_to_swp_entry(pmd);
1509 			unsigned long offset;
1510 
1511 			if (pm->show_pfn) {
1512 				if (is_pfn_swap_entry(entry))
1513 					offset = swp_offset_pfn(entry) + idx;
1514 				else
1515 					offset = swp_offset(entry) + idx;
1516 				frame = swp_type(entry) |
1517 					(offset << MAX_SWAPFILES_SHIFT);
1518 			}
1519 			flags |= PM_SWAP;
1520 			if (pmd_swp_soft_dirty(pmd))
1521 				flags |= PM_SOFT_DIRTY;
1522 			if (pmd_swp_uffd_wp(pmd))
1523 				flags |= PM_UFFD_WP;
1524 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
1525 			page = pfn_swap_entry_to_page(entry);
1526 		}
1527 #endif
1528 
1529 		if (page && !PageAnon(page))
1530 			flags |= PM_FILE;
1531 
1532 		for (; addr != end; addr += PAGE_SIZE, idx++) {
1533 			u64 cur_flags = flags;
1534 			pagemap_entry_t pme;
1535 
1536 			if (page && (flags & PM_PRESENT) &&
1537 			    page_mapcount(page + idx) == 1)
1538 				cur_flags |= PM_MMAP_EXCLUSIVE;
1539 
1540 			pme = make_pme(frame, cur_flags);
1541 			err = add_to_pagemap(&pme, pm);
1542 			if (err)
1543 				break;
1544 			if (pm->show_pfn) {
1545 				if (flags & PM_PRESENT)
1546 					frame++;
1547 				else if (flags & PM_SWAP)
1548 					frame += (1 << MAX_SWAPFILES_SHIFT);
1549 			}
1550 		}
1551 		spin_unlock(ptl);
1552 		return err;
1553 	}
1554 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1555 
1556 	/*
1557 	 * We can assume that @vma always points to a valid one and @end never
1558 	 * goes beyond vma->vm_end.
1559 	 */
1560 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1561 	if (!pte) {
1562 		walk->action = ACTION_AGAIN;
1563 		return err;
1564 	}
1565 	for (; addr < end; pte++, addr += PAGE_SIZE) {
1566 		pagemap_entry_t pme;
1567 
1568 		pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
1569 		err = add_to_pagemap(&pme, pm);
1570 		if (err)
1571 			break;
1572 	}
1573 	pte_unmap_unlock(orig_pte, ptl);
1574 
1575 	cond_resched();
1576 
1577 	return err;
1578 }
1579 
1580 #ifdef CONFIG_HUGETLB_PAGE
1581 /* 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)1582 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1583 				 unsigned long addr, unsigned long end,
1584 				 struct mm_walk *walk)
1585 {
1586 	struct pagemapread *pm = walk->private;
1587 	struct vm_area_struct *vma = walk->vma;
1588 	u64 flags = 0, frame = 0;
1589 	int err = 0;
1590 	pte_t pte;
1591 
1592 	if (vma->vm_flags & VM_SOFTDIRTY)
1593 		flags |= PM_SOFT_DIRTY;
1594 
1595 	pte = huge_ptep_get(ptep);
1596 	if (pte_present(pte)) {
1597 		struct page *page = pte_page(pte);
1598 
1599 		if (!PageAnon(page))
1600 			flags |= PM_FILE;
1601 
1602 		if (page_mapcount(page) == 1)
1603 			flags |= PM_MMAP_EXCLUSIVE;
1604 
1605 		if (huge_pte_uffd_wp(pte))
1606 			flags |= PM_UFFD_WP;
1607 
1608 		flags |= PM_PRESENT;
1609 		if (pm->show_pfn)
1610 			frame = pte_pfn(pte) +
1611 				((addr & ~hmask) >> PAGE_SHIFT);
1612 	} else if (pte_swp_uffd_wp_any(pte)) {
1613 		flags |= PM_UFFD_WP;
1614 	}
1615 
1616 	for (; addr != end; addr += PAGE_SIZE) {
1617 		pagemap_entry_t pme = make_pme(frame, flags);
1618 
1619 		err = add_to_pagemap(&pme, pm);
1620 		if (err)
1621 			return err;
1622 		if (pm->show_pfn && (flags & PM_PRESENT))
1623 			frame++;
1624 	}
1625 
1626 	cond_resched();
1627 
1628 	return err;
1629 }
1630 #else
1631 #define pagemap_hugetlb_range	NULL
1632 #endif /* HUGETLB_PAGE */
1633 
1634 static const struct mm_walk_ops pagemap_ops = {
1635 	.pmd_entry	= pagemap_pmd_range,
1636 	.pte_hole	= pagemap_pte_hole,
1637 	.hugetlb_entry	= pagemap_hugetlb_range,
1638 	.walk_lock	= PGWALK_RDLOCK,
1639 };
1640 
1641 /*
1642  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1643  *
1644  * For each page in the address space, this file contains one 64-bit entry
1645  * consisting of the following:
1646  *
1647  * Bits 0-54  page frame number (PFN) if present
1648  * Bits 0-4   swap type if swapped
1649  * Bits 5-54  swap offset if swapped
1650  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1651  * Bit  56    page exclusively mapped
1652  * Bit  57    pte is uffd-wp write-protected
1653  * Bits 58-60 zero
1654  * Bit  61    page is file-page or shared-anon
1655  * Bit  62    page swapped
1656  * Bit  63    page present
1657  *
1658  * If the page is not present but in swap, then the PFN contains an
1659  * encoding of the swap file number and the page's offset into the
1660  * swap. Unmapped pages return a null PFN. This allows determining
1661  * precisely which pages are mapped (or in swap) and comparing mapped
1662  * pages between processes.
1663  *
1664  * Efficient users of this interface will use /proc/pid/maps to
1665  * determine which areas of memory are actually mapped and llseek to
1666  * skip over unmapped regions.
1667  */
pagemap_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1668 static ssize_t pagemap_read(struct file *file, char __user *buf,
1669 			    size_t count, loff_t *ppos)
1670 {
1671 	struct mm_struct *mm = file->private_data;
1672 	struct pagemapread pm;
1673 	unsigned long src;
1674 	unsigned long svpfn;
1675 	unsigned long start_vaddr;
1676 	unsigned long end_vaddr;
1677 	int ret = 0, copied = 0;
1678 
1679 	if (!mm || !mmget_not_zero(mm))
1680 		goto out;
1681 
1682 	ret = -EINVAL;
1683 	/* file position must be aligned */
1684 	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1685 		goto out_mm;
1686 
1687 	ret = 0;
1688 	if (!count)
1689 		goto out_mm;
1690 
1691 	/* do not disclose physical addresses: attack vector */
1692 	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1693 
1694 	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1695 	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1696 	ret = -ENOMEM;
1697 	if (!pm.buffer)
1698 		goto out_mm;
1699 
1700 	src = *ppos;
1701 	svpfn = src / PM_ENTRY_BYTES;
1702 	end_vaddr = mm->task_size;
1703 
1704 	/* watch out for wraparound */
1705 	start_vaddr = end_vaddr;
1706 	if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
1707 		unsigned long end;
1708 
1709 		ret = mmap_read_lock_killable(mm);
1710 		if (ret)
1711 			goto out_free;
1712 		start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1713 		mmap_read_unlock(mm);
1714 
1715 		end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1716 		if (end >= start_vaddr && end < mm->task_size)
1717 			end_vaddr = end;
1718 	}
1719 
1720 	/* Ensure the address is inside the task */
1721 	if (start_vaddr > mm->task_size)
1722 		start_vaddr = end_vaddr;
1723 
1724 	ret = 0;
1725 	while (count && (start_vaddr < end_vaddr)) {
1726 		int len;
1727 		unsigned long end;
1728 
1729 		pm.pos = 0;
1730 		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1731 		/* overflow ? */
1732 		if (end < start_vaddr || end > end_vaddr)
1733 			end = end_vaddr;
1734 		ret = mmap_read_lock_killable(mm);
1735 		if (ret)
1736 			goto out_free;
1737 		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1738 		mmap_read_unlock(mm);
1739 		start_vaddr = end;
1740 
1741 		len = min(count, PM_ENTRY_BYTES * pm.pos);
1742 		if (copy_to_user(buf, pm.buffer, len)) {
1743 			ret = -EFAULT;
1744 			goto out_free;
1745 		}
1746 		copied += len;
1747 		buf += len;
1748 		count -= len;
1749 	}
1750 	*ppos += copied;
1751 	if (!ret || ret == PM_END_OF_BUFFER)
1752 		ret = copied;
1753 
1754 out_free:
1755 	kfree(pm.buffer);
1756 out_mm:
1757 	mmput(mm);
1758 out:
1759 	return ret;
1760 }
1761 
pagemap_open(struct inode * inode,struct file * file)1762 static int pagemap_open(struct inode *inode, struct file *file)
1763 {
1764 	struct mm_struct *mm;
1765 
1766 	mm = proc_mem_open(inode, PTRACE_MODE_READ);
1767 	if (IS_ERR(mm))
1768 		return PTR_ERR(mm);
1769 	file->private_data = mm;
1770 	return 0;
1771 }
1772 
pagemap_release(struct inode * inode,struct file * file)1773 static int pagemap_release(struct inode *inode, struct file *file)
1774 {
1775 	struct mm_struct *mm = file->private_data;
1776 
1777 	if (mm)
1778 		mmdrop(mm);
1779 	return 0;
1780 }
1781 
1782 const struct file_operations proc_pagemap_operations = {
1783 	.llseek		= mem_lseek, /* borrow this */
1784 	.read		= pagemap_read,
1785 	.open		= pagemap_open,
1786 	.release	= pagemap_release,
1787 };
1788 #endif /* CONFIG_PROC_PAGE_MONITOR */
1789 
1790 #ifdef CONFIG_NUMA
1791 
1792 struct numa_maps {
1793 	unsigned long pages;
1794 	unsigned long anon;
1795 	unsigned long active;
1796 	unsigned long writeback;
1797 	unsigned long mapcount_max;
1798 	unsigned long dirty;
1799 	unsigned long swapcache;
1800 	unsigned long node[MAX_NUMNODES];
1801 };
1802 
1803 struct numa_maps_private {
1804 	struct proc_maps_private proc_maps;
1805 	struct numa_maps md;
1806 };
1807 
gather_stats(struct page * page,struct numa_maps * md,int pte_dirty,unsigned long nr_pages)1808 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1809 			unsigned long nr_pages)
1810 {
1811 	int count = page_mapcount(page);
1812 
1813 	md->pages += nr_pages;
1814 	if (pte_dirty || PageDirty(page))
1815 		md->dirty += nr_pages;
1816 
1817 	if (PageSwapCache(page))
1818 		md->swapcache += nr_pages;
1819 
1820 	if (PageActive(page) || PageUnevictable(page))
1821 		md->active += nr_pages;
1822 
1823 	if (PageWriteback(page))
1824 		md->writeback += nr_pages;
1825 
1826 	if (PageAnon(page))
1827 		md->anon += nr_pages;
1828 
1829 	if (count > md->mapcount_max)
1830 		md->mapcount_max = count;
1831 
1832 	md->node[page_to_nid(page)] += nr_pages;
1833 }
1834 
can_gather_numa_stats(pte_t pte,struct vm_area_struct * vma,unsigned long addr)1835 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1836 		unsigned long addr)
1837 {
1838 	struct page *page;
1839 	int nid;
1840 
1841 	if (!pte_present(pte))
1842 		return NULL;
1843 
1844 	page = vm_normal_page(vma, addr, pte);
1845 	if (!page || is_zone_device_page(page))
1846 		return NULL;
1847 
1848 	if (PageReserved(page))
1849 		return NULL;
1850 
1851 	nid = page_to_nid(page);
1852 	if (!node_isset(nid, node_states[N_MEMORY]))
1853 		return NULL;
1854 
1855 	return page;
1856 }
1857 
1858 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
can_gather_numa_stats_pmd(pmd_t pmd,struct vm_area_struct * vma,unsigned long addr)1859 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1860 					      struct vm_area_struct *vma,
1861 					      unsigned long addr)
1862 {
1863 	struct page *page;
1864 	int nid;
1865 
1866 	if (!pmd_present(pmd))
1867 		return NULL;
1868 
1869 	page = vm_normal_page_pmd(vma, addr, pmd);
1870 	if (!page)
1871 		return NULL;
1872 
1873 	if (PageReserved(page))
1874 		return NULL;
1875 
1876 	nid = page_to_nid(page);
1877 	if (!node_isset(nid, node_states[N_MEMORY]))
1878 		return NULL;
1879 
1880 	return page;
1881 }
1882 #endif
1883 
gather_pte_stats(pmd_t * pmd,unsigned long addr,unsigned long end,struct mm_walk * walk)1884 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1885 		unsigned long end, struct mm_walk *walk)
1886 {
1887 	struct numa_maps *md = walk->private;
1888 	struct vm_area_struct *vma = walk->vma;
1889 	spinlock_t *ptl;
1890 	pte_t *orig_pte;
1891 	pte_t *pte;
1892 
1893 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1894 	ptl = pmd_trans_huge_lock(pmd, vma);
1895 	if (ptl) {
1896 		struct page *page;
1897 
1898 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1899 		if (page)
1900 			gather_stats(page, md, pmd_dirty(*pmd),
1901 				     HPAGE_PMD_SIZE/PAGE_SIZE);
1902 		spin_unlock(ptl);
1903 		return 0;
1904 	}
1905 #endif
1906 	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1907 	if (!pte) {
1908 		walk->action = ACTION_AGAIN;
1909 		return 0;
1910 	}
1911 	do {
1912 		pte_t ptent = ptep_get(pte);
1913 		struct page *page = can_gather_numa_stats(ptent, vma, addr);
1914 		if (!page)
1915 			continue;
1916 		gather_stats(page, md, pte_dirty(ptent), 1);
1917 
1918 	} while (pte++, addr += PAGE_SIZE, addr != end);
1919 	pte_unmap_unlock(orig_pte, ptl);
1920 	cond_resched();
1921 	return 0;
1922 }
1923 #ifdef CONFIG_HUGETLB_PAGE
gather_hugetlb_stats(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)1924 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1925 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1926 {
1927 	pte_t huge_pte = huge_ptep_get(pte);
1928 	struct numa_maps *md;
1929 	struct page *page;
1930 
1931 	if (!pte_present(huge_pte))
1932 		return 0;
1933 
1934 	page = pte_page(huge_pte);
1935 
1936 	md = walk->private;
1937 	gather_stats(page, md, pte_dirty(huge_pte), 1);
1938 	return 0;
1939 }
1940 
1941 #else
gather_hugetlb_stats(pte_t * pte,unsigned long hmask,unsigned long addr,unsigned long end,struct mm_walk * walk)1942 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1943 		unsigned long addr, unsigned long end, struct mm_walk *walk)
1944 {
1945 	return 0;
1946 }
1947 #endif
1948 
1949 static const struct mm_walk_ops show_numa_ops = {
1950 	.hugetlb_entry = gather_hugetlb_stats,
1951 	.pmd_entry = gather_pte_stats,
1952 	.walk_lock = PGWALK_RDLOCK,
1953 };
1954 
1955 /*
1956  * Display pages allocated per node and memory policy via /proc.
1957  */
show_numa_map(struct seq_file * m,void * v)1958 static int show_numa_map(struct seq_file *m, void *v)
1959 {
1960 	struct numa_maps_private *numa_priv = m->private;
1961 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1962 	struct vm_area_struct *vma = v;
1963 	struct numa_maps *md = &numa_priv->md;
1964 	struct file *file = vma->vm_file;
1965 	struct mm_struct *mm = vma->vm_mm;
1966 	struct mempolicy *pol;
1967 	char buffer[64];
1968 	int nid;
1969 
1970 	if (!mm)
1971 		return 0;
1972 
1973 	/* Ensure we start with an empty set of numa_maps statistics. */
1974 	memset(md, 0, sizeof(*md));
1975 
1976 	pol = __get_vma_policy(vma, vma->vm_start);
1977 	if (pol) {
1978 		mpol_to_str(buffer, sizeof(buffer), pol);
1979 		mpol_cond_put(pol);
1980 	} else {
1981 		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1982 	}
1983 
1984 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1985 
1986 	if (file) {
1987 		seq_puts(m, " file=");
1988 		seq_file_path(m, file, "\n\t= ");
1989 	} else if (vma_is_initial_heap(vma)) {
1990 		seq_puts(m, " heap");
1991 	} else if (vma_is_initial_stack(vma)) {
1992 		seq_puts(m, " stack");
1993 	}
1994 
1995 	if (is_vm_hugetlb_page(vma))
1996 		seq_puts(m, " huge");
1997 
1998 	/* mmap_lock is held by m_start */
1999 	walk_page_vma(vma, &show_numa_ops, md);
2000 
2001 	if (!md->pages)
2002 		goto out;
2003 
2004 	if (md->anon)
2005 		seq_printf(m, " anon=%lu", md->anon);
2006 
2007 	if (md->dirty)
2008 		seq_printf(m, " dirty=%lu", md->dirty);
2009 
2010 	if (md->pages != md->anon && md->pages != md->dirty)
2011 		seq_printf(m, " mapped=%lu", md->pages);
2012 
2013 	if (md->mapcount_max > 1)
2014 		seq_printf(m, " mapmax=%lu", md->mapcount_max);
2015 
2016 	if (md->swapcache)
2017 		seq_printf(m, " swapcache=%lu", md->swapcache);
2018 
2019 	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2020 		seq_printf(m, " active=%lu", md->active);
2021 
2022 	if (md->writeback)
2023 		seq_printf(m, " writeback=%lu", md->writeback);
2024 
2025 	for_each_node_state(nid, N_MEMORY)
2026 		if (md->node[nid])
2027 			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
2028 
2029 	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
2030 out:
2031 	seq_putc(m, '\n');
2032 	return 0;
2033 }
2034 
2035 static const struct seq_operations proc_pid_numa_maps_op = {
2036 	.start  = m_start,
2037 	.next   = m_next,
2038 	.stop   = m_stop,
2039 	.show   = show_numa_map,
2040 };
2041 
pid_numa_maps_open(struct inode * inode,struct file * file)2042 static int pid_numa_maps_open(struct inode *inode, struct file *file)
2043 {
2044 	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2045 				sizeof(struct numa_maps_private));
2046 }
2047 
2048 const struct file_operations proc_pid_numa_maps_operations = {
2049 	.open		= pid_numa_maps_open,
2050 	.read		= seq_read,
2051 	.llseek		= seq_lseek,
2052 	.release	= proc_map_release,
2053 };
2054 
2055 #endif /* CONFIG_NUMA */
2056