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1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/mm.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
22 #include <asm/elf.h>
23 #include <asm/tlb.h>
24 #include <asm/tlbflush.h>
25 #include "internal.h"
26
27 void task_mem(struct seq_file *m, struct mm_struct *mm)
28 {
29 unsigned long text, lib, swap, anon, file, shmem;
30 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
31
32 anon = get_mm_counter(mm, MM_ANONPAGES);
33 file = get_mm_counter(mm, MM_FILEPAGES);
34 shmem = get_mm_counter(mm, MM_SHMEMPAGES);
35
36 /*
37 * Note: to minimize their overhead, mm maintains hiwater_vm and
38 * hiwater_rss only when about to *lower* total_vm or rss. Any
39 * collector of these hiwater stats must therefore get total_vm
40 * and rss too, which will usually be the higher. Barriers? not
41 * worth the effort, such snapshots can always be inconsistent.
42 */
43 hiwater_vm = total_vm = mm->total_vm;
44 if (hiwater_vm < mm->hiwater_vm)
45 hiwater_vm = mm->hiwater_vm;
46 hiwater_rss = total_rss = anon + file + shmem;
47 if (hiwater_rss < mm->hiwater_rss)
48 hiwater_rss = mm->hiwater_rss;
49
50 text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
51 lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
52 swap = get_mm_counter(mm, MM_SWAPENTS);
53 seq_printf(m,
54 "VmPeak:\t%8lu kB\n"
55 "VmSize:\t%8lu kB\n"
56 "VmLck:\t%8lu kB\n"
57 "VmPin:\t%8lu kB\n"
58 "VmHWM:\t%8lu kB\n"
59 "VmRSS:\t%8lu kB\n"
60 "RssAnon:\t%8lu kB\n"
61 "RssFile:\t%8lu kB\n"
62 "RssShmem:\t%8lu kB\n"
63 "VmData:\t%8lu kB\n"
64 "VmStk:\t%8lu kB\n"
65 "VmExe:\t%8lu kB\n"
66 "VmLib:\t%8lu kB\n"
67 "VmPTE:\t%8lu kB\n"
68 "VmSwap:\t%8lu kB\n",
69 hiwater_vm << (PAGE_SHIFT-10),
70 total_vm << (PAGE_SHIFT-10),
71 mm->locked_vm << (PAGE_SHIFT-10),
72 mm->pinned_vm << (PAGE_SHIFT-10),
73 hiwater_rss << (PAGE_SHIFT-10),
74 total_rss << (PAGE_SHIFT-10),
75 anon << (PAGE_SHIFT-10),
76 file << (PAGE_SHIFT-10),
77 shmem << (PAGE_SHIFT-10),
78 mm->data_vm << (PAGE_SHIFT-10),
79 mm->stack_vm << (PAGE_SHIFT-10), text, lib,
80 mm_pgtables_bytes(mm) >> 10,
81 swap << (PAGE_SHIFT-10));
82 hugetlb_report_usage(m, mm);
83 }
84
85 unsigned long task_vsize(struct mm_struct *mm)
86 {
87 return PAGE_SIZE * mm->total_vm;
88 }
89
90 unsigned long task_statm(struct mm_struct *mm,
91 unsigned long *shared, unsigned long *text,
92 unsigned long *data, unsigned long *resident)
93 {
94 *shared = get_mm_counter(mm, MM_FILEPAGES) +
95 get_mm_counter(mm, MM_SHMEMPAGES);
96 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
97 >> PAGE_SHIFT;
98 *data = mm->data_vm + mm->stack_vm;
99 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
100 return mm->total_vm;
101 }
102
103 #ifdef CONFIG_NUMA
104 /*
105 * Save get_task_policy() for show_numa_map().
106 */
107 static void hold_task_mempolicy(struct proc_maps_private *priv)
108 {
109 struct task_struct *task = priv->task;
110
111 task_lock(task);
112 priv->task_mempolicy = get_task_policy(task);
113 mpol_get(priv->task_mempolicy);
114 task_unlock(task);
115 }
116 static void release_task_mempolicy(struct proc_maps_private *priv)
117 {
118 mpol_put(priv->task_mempolicy);
119 }
120 #else
121 static void hold_task_mempolicy(struct proc_maps_private *priv)
122 {
123 }
124 static void release_task_mempolicy(struct proc_maps_private *priv)
125 {
126 }
127 #endif
128
129 static void vma_stop(struct proc_maps_private *priv)
130 {
131 struct mm_struct *mm = priv->mm;
132
133 release_task_mempolicy(priv);
134 up_read(&mm->mmap_sem);
135 mmput(mm);
136 }
137
138 static struct vm_area_struct *
139 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
140 {
141 if (vma == priv->tail_vma)
142 return NULL;
143 return vma->vm_next ?: priv->tail_vma;
144 }
145
146 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
147 {
148 if (m->count < m->size) /* vma is copied successfully */
149 m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
150 }
151
152 static void *m_start(struct seq_file *m, loff_t *ppos)
153 {
154 struct proc_maps_private *priv = m->private;
155 unsigned long last_addr = m->version;
156 struct mm_struct *mm;
157 struct vm_area_struct *vma;
158 unsigned int pos = *ppos;
159
160 /* See m_cache_vma(). Zero at the start or after lseek. */
161 if (last_addr == -1UL)
162 return NULL;
163
164 priv->task = get_proc_task(priv->inode);
165 if (!priv->task)
166 return ERR_PTR(-ESRCH);
167
168 mm = priv->mm;
169 if (!mm || !mmget_not_zero(mm))
170 return NULL;
171
172 down_read(&mm->mmap_sem);
173 hold_task_mempolicy(priv);
174 priv->tail_vma = get_gate_vma(mm);
175
176 if (last_addr) {
177 vma = find_vma(mm, last_addr - 1);
178 if (vma && vma->vm_start <= last_addr)
179 vma = m_next_vma(priv, vma);
180 if (vma)
181 return vma;
182 }
183
184 m->version = 0;
185 if (pos < mm->map_count) {
186 for (vma = mm->mmap; pos; pos--) {
187 m->version = vma->vm_start;
188 vma = vma->vm_next;
189 }
190 return vma;
191 }
192
193 /* we do not bother to update m->version in this case */
194 if (pos == mm->map_count && priv->tail_vma)
195 return priv->tail_vma;
196
197 vma_stop(priv);
198 return NULL;
199 }
200
201 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
202 {
203 struct proc_maps_private *priv = m->private;
204 struct vm_area_struct *next;
205
206 (*pos)++;
207 next = m_next_vma(priv, v);
208 if (!next)
209 vma_stop(priv);
210 return next;
211 }
212
213 static void m_stop(struct seq_file *m, void *v)
214 {
215 struct proc_maps_private *priv = m->private;
216
217 if (!IS_ERR_OR_NULL(v))
218 vma_stop(priv);
219 if (priv->task) {
220 put_task_struct(priv->task);
221 priv->task = NULL;
222 }
223 }
224
225 static int proc_maps_open(struct inode *inode, struct file *file,
226 const struct seq_operations *ops, int psize)
227 {
228 struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
229
230 if (!priv)
231 return -ENOMEM;
232
233 priv->inode = inode;
234 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
235 if (IS_ERR(priv->mm)) {
236 int err = PTR_ERR(priv->mm);
237
238 seq_release_private(inode, file);
239 return err;
240 }
241
242 return 0;
243 }
244
245 static int proc_map_release(struct inode *inode, struct file *file)
246 {
247 struct seq_file *seq = file->private_data;
248 struct proc_maps_private *priv = seq->private;
249
250 if (priv->mm)
251 mmdrop(priv->mm);
252
253 kfree(priv->rollup);
254 return seq_release_private(inode, file);
255 }
256
257 static int do_maps_open(struct inode *inode, struct file *file,
258 const struct seq_operations *ops)
259 {
260 return proc_maps_open(inode, file, ops,
261 sizeof(struct proc_maps_private));
262 }
263
264 /*
265 * Indicate if the VMA is a stack for the given task; for
266 * /proc/PID/maps that is the stack of the main task.
267 */
268 static int is_stack(struct vm_area_struct *vma)
269 {
270 /*
271 * We make no effort to guess what a given thread considers to be
272 * its "stack". It's not even well-defined for programs written
273 * languages like Go.
274 */
275 return vma->vm_start <= vma->vm_mm->start_stack &&
276 vma->vm_end >= vma->vm_mm->start_stack;
277 }
278
279 static void show_vma_header_prefix(struct seq_file *m,
280 unsigned long start, unsigned long end,
281 vm_flags_t flags, unsigned long long pgoff,
282 dev_t dev, unsigned long ino)
283 {
284 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
285 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
286 start,
287 end,
288 flags & VM_READ ? 'r' : '-',
289 flags & VM_WRITE ? 'w' : '-',
290 flags & VM_EXEC ? 'x' : '-',
291 flags & VM_MAYSHARE ? 's' : 'p',
292 pgoff,
293 MAJOR(dev), MINOR(dev), ino);
294 }
295
296 static void
297 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
298 {
299 struct mm_struct *mm = vma->vm_mm;
300 struct file *file = vma->vm_file;
301 vm_flags_t flags = vma->vm_flags;
302 unsigned long ino = 0;
303 unsigned long long pgoff = 0;
304 unsigned long start, end;
305 dev_t dev = 0;
306 const char *name = NULL;
307
308 if (file) {
309 struct inode *inode = file_inode(vma->vm_file);
310 dev = inode->i_sb->s_dev;
311 ino = inode->i_ino;
312 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
313 }
314
315 start = vma->vm_start;
316 end = vma->vm_end;
317 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
318
319 /*
320 * Print the dentry name for named mappings, and a
321 * special [heap] marker for the heap:
322 */
323 if (file) {
324 seq_pad(m, ' ');
325 seq_file_path(m, file, "\n");
326 goto done;
327 }
328
329 if (vma->vm_ops && vma->vm_ops->name) {
330 name = vma->vm_ops->name(vma);
331 if (name)
332 goto done;
333 }
334
335 name = arch_vma_name(vma);
336 if (!name) {
337 if (!mm) {
338 name = "[vdso]";
339 goto done;
340 }
341
342 if (vma->vm_start <= mm->brk &&
343 vma->vm_end >= mm->start_brk) {
344 name = "[heap]";
345 goto done;
346 }
347
348 if (is_stack(vma))
349 name = "[stack]";
350 }
351
352 done:
353 if (name) {
354 seq_pad(m, ' ');
355 seq_puts(m, name);
356 }
357 seq_putc(m, '\n');
358 }
359
360 static int show_map(struct seq_file *m, void *v, int is_pid)
361 {
362 show_map_vma(m, v, is_pid);
363 m_cache_vma(m, v);
364 return 0;
365 }
366
367 static int show_pid_map(struct seq_file *m, void *v)
368 {
369 return show_map(m, v, 1);
370 }
371
372 static int show_tid_map(struct seq_file *m, void *v)
373 {
374 return show_map(m, v, 0);
375 }
376
377 static const struct seq_operations proc_pid_maps_op = {
378 .start = m_start,
379 .next = m_next,
380 .stop = m_stop,
381 .show = show_pid_map
382 };
383
384 static const struct seq_operations proc_tid_maps_op = {
385 .start = m_start,
386 .next = m_next,
387 .stop = m_stop,
388 .show = show_tid_map
389 };
390
391 static int pid_maps_open(struct inode *inode, struct file *file)
392 {
393 return do_maps_open(inode, file, &proc_pid_maps_op);
394 }
395
396 static int tid_maps_open(struct inode *inode, struct file *file)
397 {
398 return do_maps_open(inode, file, &proc_tid_maps_op);
399 }
400
401 const struct file_operations proc_pid_maps_operations = {
402 .open = pid_maps_open,
403 .read = seq_read,
404 .llseek = seq_lseek,
405 .release = proc_map_release,
406 };
407
408 const struct file_operations proc_tid_maps_operations = {
409 .open = tid_maps_open,
410 .read = seq_read,
411 .llseek = seq_lseek,
412 .release = proc_map_release,
413 };
414
415 /*
416 * Proportional Set Size(PSS): my share of RSS.
417 *
418 * PSS of a process is the count of pages it has in memory, where each
419 * page is divided by the number of processes sharing it. So if a
420 * process has 1000 pages all to itself, and 1000 shared with one other
421 * process, its PSS will be 1500.
422 *
423 * To keep (accumulated) division errors low, we adopt a 64bit
424 * fixed-point pss counter to minimize division errors. So (pss >>
425 * PSS_SHIFT) would be the real byte count.
426 *
427 * A shift of 12 before division means (assuming 4K page size):
428 * - 1M 3-user-pages add up to 8KB errors;
429 * - supports mapcount up to 2^24, or 16M;
430 * - supports PSS up to 2^52 bytes, or 4PB.
431 */
432 #define PSS_SHIFT 12
433
434 #ifdef CONFIG_PROC_PAGE_MONITOR
435 struct mem_size_stats {
436 bool first;
437 unsigned long resident;
438 unsigned long shared_clean;
439 unsigned long shared_dirty;
440 unsigned long private_clean;
441 unsigned long private_dirty;
442 unsigned long referenced;
443 unsigned long anonymous;
444 unsigned long lazyfree;
445 unsigned long anonymous_thp;
446 unsigned long shmem_thp;
447 unsigned long swap;
448 unsigned long shared_hugetlb;
449 unsigned long private_hugetlb;
450 unsigned long first_vma_start;
451 u64 pss;
452 u64 pss_locked;
453 u64 swap_pss;
454 bool check_shmem_swap;
455 };
456
457 static void smaps_account(struct mem_size_stats *mss, struct page *page,
458 bool compound, bool young, bool dirty)
459 {
460 int i, nr = compound ? 1 << compound_order(page) : 1;
461 unsigned long size = nr * PAGE_SIZE;
462
463 if (PageAnon(page)) {
464 mss->anonymous += size;
465 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
466 mss->lazyfree += size;
467 }
468
469 mss->resident += size;
470 /* Accumulate the size in pages that have been accessed. */
471 if (young || page_is_young(page) || PageReferenced(page))
472 mss->referenced += size;
473
474 /*
475 * page_count(page) == 1 guarantees the page is mapped exactly once.
476 * If any subpage of the compound page mapped with PTE it would elevate
477 * page_count().
478 */
479 if (page_count(page) == 1) {
480 if (dirty || PageDirty(page))
481 mss->private_dirty += size;
482 else
483 mss->private_clean += size;
484 mss->pss += (u64)size << PSS_SHIFT;
485 return;
486 }
487
488 for (i = 0; i < nr; i++, page++) {
489 int mapcount = page_mapcount(page);
490
491 if (mapcount >= 2) {
492 if (dirty || PageDirty(page))
493 mss->shared_dirty += PAGE_SIZE;
494 else
495 mss->shared_clean += PAGE_SIZE;
496 mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
497 } else {
498 if (dirty || PageDirty(page))
499 mss->private_dirty += PAGE_SIZE;
500 else
501 mss->private_clean += PAGE_SIZE;
502 mss->pss += PAGE_SIZE << PSS_SHIFT;
503 }
504 }
505 }
506
507 #ifdef CONFIG_SHMEM
508 static int smaps_pte_hole(unsigned long addr, unsigned long end,
509 struct mm_walk *walk)
510 {
511 struct mem_size_stats *mss = walk->private;
512
513 mss->swap += shmem_partial_swap_usage(
514 walk->vma->vm_file->f_mapping, addr, end);
515
516 return 0;
517 }
518 #endif
519
520 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
521 struct mm_walk *walk)
522 {
523 struct mem_size_stats *mss = walk->private;
524 struct vm_area_struct *vma = walk->vma;
525 struct page *page = NULL;
526
527 if (pte_present(*pte)) {
528 page = vm_normal_page(vma, addr, *pte);
529 } else if (is_swap_pte(*pte)) {
530 swp_entry_t swpent = pte_to_swp_entry(*pte);
531
532 if (!non_swap_entry(swpent)) {
533 int mapcount;
534
535 mss->swap += PAGE_SIZE;
536 mapcount = swp_swapcount(swpent);
537 if (mapcount >= 2) {
538 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
539
540 do_div(pss_delta, mapcount);
541 mss->swap_pss += pss_delta;
542 } else {
543 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
544 }
545 } else if (is_migration_entry(swpent))
546 page = migration_entry_to_page(swpent);
547 else if (is_device_private_entry(swpent))
548 page = device_private_entry_to_page(swpent);
549 } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
550 && pte_none(*pte))) {
551 page = find_get_entry(vma->vm_file->f_mapping,
552 linear_page_index(vma, addr));
553 if (!page)
554 return;
555
556 if (radix_tree_exceptional_entry(page))
557 mss->swap += PAGE_SIZE;
558 else
559 put_page(page);
560
561 return;
562 }
563
564 if (!page)
565 return;
566
567 smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
568 }
569
570 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
571 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
572 struct mm_walk *walk)
573 {
574 struct mem_size_stats *mss = walk->private;
575 struct vm_area_struct *vma = walk->vma;
576 struct page *page;
577
578 /* FOLL_DUMP will return -EFAULT on huge zero page */
579 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
580 if (IS_ERR_OR_NULL(page))
581 return;
582 if (PageAnon(page))
583 mss->anonymous_thp += HPAGE_PMD_SIZE;
584 else if (PageSwapBacked(page))
585 mss->shmem_thp += HPAGE_PMD_SIZE;
586 else if (is_zone_device_page(page))
587 /* pass */;
588 else
589 VM_BUG_ON_PAGE(1, page);
590 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
591 }
592 #else
593 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
594 struct mm_walk *walk)
595 {
596 }
597 #endif
598
599 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
600 struct mm_walk *walk)
601 {
602 struct vm_area_struct *vma = walk->vma;
603 pte_t *pte;
604 spinlock_t *ptl;
605
606 ptl = pmd_trans_huge_lock(pmd, vma);
607 if (ptl) {
608 if (pmd_present(*pmd))
609 smaps_pmd_entry(pmd, addr, walk);
610 spin_unlock(ptl);
611 goto out;
612 }
613
614 if (pmd_trans_unstable(pmd))
615 goto out;
616 /*
617 * The mmap_sem held all the way back in m_start() is what
618 * keeps khugepaged out of here and from collapsing things
619 * in here.
620 */
621 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
622 for (; addr != end; pte++, addr += PAGE_SIZE)
623 smaps_pte_entry(pte, addr, walk);
624 pte_unmap_unlock(pte - 1, ptl);
625 out:
626 cond_resched();
627 return 0;
628 }
629
630 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
631 {
632 /*
633 * Don't forget to update Documentation/ on changes.
634 */
635 static const char mnemonics[BITS_PER_LONG][2] = {
636 /*
637 * In case if we meet a flag we don't know about.
638 */
639 [0 ... (BITS_PER_LONG-1)] = "??",
640
641 [ilog2(VM_READ)] = "rd",
642 [ilog2(VM_WRITE)] = "wr",
643 [ilog2(VM_EXEC)] = "ex",
644 [ilog2(VM_SHARED)] = "sh",
645 [ilog2(VM_MAYREAD)] = "mr",
646 [ilog2(VM_MAYWRITE)] = "mw",
647 [ilog2(VM_MAYEXEC)] = "me",
648 [ilog2(VM_MAYSHARE)] = "ms",
649 [ilog2(VM_GROWSDOWN)] = "gd",
650 [ilog2(VM_PFNMAP)] = "pf",
651 [ilog2(VM_DENYWRITE)] = "dw",
652 #ifdef CONFIG_X86_INTEL_MPX
653 [ilog2(VM_MPX)] = "mp",
654 #endif
655 [ilog2(VM_LOCKED)] = "lo",
656 [ilog2(VM_IO)] = "io",
657 [ilog2(VM_SEQ_READ)] = "sr",
658 [ilog2(VM_RAND_READ)] = "rr",
659 [ilog2(VM_DONTCOPY)] = "dc",
660 [ilog2(VM_DONTEXPAND)] = "de",
661 [ilog2(VM_ACCOUNT)] = "ac",
662 [ilog2(VM_NORESERVE)] = "nr",
663 [ilog2(VM_HUGETLB)] = "ht",
664 [ilog2(VM_SYNC)] = "sf",
665 [ilog2(VM_ARCH_1)] = "ar",
666 [ilog2(VM_WIPEONFORK)] = "wf",
667 [ilog2(VM_DONTDUMP)] = "dd",
668 #ifdef CONFIG_MEM_SOFT_DIRTY
669 [ilog2(VM_SOFTDIRTY)] = "sd",
670 #endif
671 [ilog2(VM_MIXEDMAP)] = "mm",
672 [ilog2(VM_HUGEPAGE)] = "hg",
673 [ilog2(VM_NOHUGEPAGE)] = "nh",
674 [ilog2(VM_MERGEABLE)] = "mg",
675 [ilog2(VM_UFFD_MISSING)]= "um",
676 [ilog2(VM_UFFD_WP)] = "uw",
677 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
678 /* These come out via ProtectionKey: */
679 [ilog2(VM_PKEY_BIT0)] = "",
680 [ilog2(VM_PKEY_BIT1)] = "",
681 [ilog2(VM_PKEY_BIT2)] = "",
682 [ilog2(VM_PKEY_BIT3)] = "",
683 #endif
684 };
685 size_t i;
686
687 seq_puts(m, "VmFlags: ");
688 for (i = 0; i < BITS_PER_LONG; i++) {
689 if (!mnemonics[i][0])
690 continue;
691 if (vma->vm_flags & (1UL << i)) {
692 seq_printf(m, "%c%c ",
693 mnemonics[i][0], mnemonics[i][1]);
694 }
695 }
696 seq_putc(m, '\n');
697 }
698
699 #ifdef CONFIG_HUGETLB_PAGE
700 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
701 unsigned long addr, unsigned long end,
702 struct mm_walk *walk)
703 {
704 struct mem_size_stats *mss = walk->private;
705 struct vm_area_struct *vma = walk->vma;
706 struct page *page = NULL;
707
708 if (pte_present(*pte)) {
709 page = vm_normal_page(vma, addr, *pte);
710 } else if (is_swap_pte(*pte)) {
711 swp_entry_t swpent = pte_to_swp_entry(*pte);
712
713 if (is_migration_entry(swpent))
714 page = migration_entry_to_page(swpent);
715 else if (is_device_private_entry(swpent))
716 page = device_private_entry_to_page(swpent);
717 }
718 if (page) {
719 int mapcount = page_mapcount(page);
720
721 if (mapcount >= 2)
722 mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
723 else
724 mss->private_hugetlb += huge_page_size(hstate_vma(vma));
725 }
726 return 0;
727 }
728 #endif /* HUGETLB_PAGE */
729
730 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
731 {
732 }
733
734 static int show_smap(struct seq_file *m, void *v, int is_pid)
735 {
736 struct proc_maps_private *priv = m->private;
737 struct vm_area_struct *vma = v;
738 struct mem_size_stats mss_stack;
739 struct mem_size_stats *mss;
740 struct mm_walk smaps_walk = {
741 .pmd_entry = smaps_pte_range,
742 #ifdef CONFIG_HUGETLB_PAGE
743 .hugetlb_entry = smaps_hugetlb_range,
744 #endif
745 .mm = vma->vm_mm,
746 };
747 int ret = 0;
748 bool rollup_mode;
749 bool last_vma;
750
751 if (priv->rollup) {
752 rollup_mode = true;
753 mss = priv->rollup;
754 if (mss->first) {
755 mss->first_vma_start = vma->vm_start;
756 mss->first = false;
757 }
758 last_vma = !m_next_vma(priv, vma);
759 } else {
760 rollup_mode = false;
761 memset(&mss_stack, 0, sizeof(mss_stack));
762 mss = &mss_stack;
763 }
764
765 smaps_walk.private = mss;
766
767 #ifdef CONFIG_SHMEM
768 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
769 /*
770 * For shared or readonly shmem mappings we know that all
771 * swapped out pages belong to the shmem object, and we can
772 * obtain the swap value much more efficiently. For private
773 * writable mappings, we might have COW pages that are
774 * not affected by the parent swapped out pages of the shmem
775 * object, so we have to distinguish them during the page walk.
776 * Unless we know that the shmem object (or the part mapped by
777 * our VMA) has no swapped out pages at all.
778 */
779 unsigned long shmem_swapped = shmem_swap_usage(vma);
780
781 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
782 !(vma->vm_flags & VM_WRITE)) {
783 mss->swap = shmem_swapped;
784 } else {
785 mss->check_shmem_swap = true;
786 smaps_walk.pte_hole = smaps_pte_hole;
787 }
788 }
789 #endif
790
791 /* mmap_sem is held in m_start */
792 walk_page_vma(vma, &smaps_walk);
793 if (vma->vm_flags & VM_LOCKED)
794 mss->pss_locked += mss->pss;
795
796 if (!rollup_mode) {
797 show_map_vma(m, vma, is_pid);
798 } else if (last_vma) {
799 show_vma_header_prefix(
800 m, mss->first_vma_start, vma->vm_end, 0, 0, 0, 0);
801 seq_pad(m, ' ');
802 seq_puts(m, "[rollup]\n");
803 } else {
804 ret = SEQ_SKIP;
805 }
806
807 if (!rollup_mode)
808 seq_printf(m,
809 "Size: %8lu kB\n"
810 "KernelPageSize: %8lu kB\n"
811 "MMUPageSize: %8lu kB\n",
812 (vma->vm_end - vma->vm_start) >> 10,
813 vma_kernel_pagesize(vma) >> 10,
814 vma_mmu_pagesize(vma) >> 10);
815
816
817 if (!rollup_mode || last_vma)
818 seq_printf(m,
819 "Rss: %8lu kB\n"
820 "Pss: %8lu kB\n"
821 "Shared_Clean: %8lu kB\n"
822 "Shared_Dirty: %8lu kB\n"
823 "Private_Clean: %8lu kB\n"
824 "Private_Dirty: %8lu kB\n"
825 "Referenced: %8lu kB\n"
826 "Anonymous: %8lu kB\n"
827 "LazyFree: %8lu kB\n"
828 "AnonHugePages: %8lu kB\n"
829 "ShmemPmdMapped: %8lu kB\n"
830 "Shared_Hugetlb: %8lu kB\n"
831 "Private_Hugetlb: %7lu kB\n"
832 "Swap: %8lu kB\n"
833 "SwapPss: %8lu kB\n"
834 "Locked: %8lu kB\n",
835 mss->resident >> 10,
836 (unsigned long)(mss->pss >> (10 + PSS_SHIFT)),
837 mss->shared_clean >> 10,
838 mss->shared_dirty >> 10,
839 mss->private_clean >> 10,
840 mss->private_dirty >> 10,
841 mss->referenced >> 10,
842 mss->anonymous >> 10,
843 mss->lazyfree >> 10,
844 mss->anonymous_thp >> 10,
845 mss->shmem_thp >> 10,
846 mss->shared_hugetlb >> 10,
847 mss->private_hugetlb >> 10,
848 mss->swap >> 10,
849 (unsigned long)(mss->swap_pss >> (10 + PSS_SHIFT)),
850 (unsigned long)(mss->pss >> (10 + PSS_SHIFT)));
851
852 if (!rollup_mode) {
853 arch_show_smap(m, vma);
854 show_smap_vma_flags(m, vma);
855 }
856 m_cache_vma(m, vma);
857 return ret;
858 }
859
860 static int show_pid_smap(struct seq_file *m, void *v)
861 {
862 return show_smap(m, v, 1);
863 }
864
865 static int show_tid_smap(struct seq_file *m, void *v)
866 {
867 return show_smap(m, v, 0);
868 }
869
870 static const struct seq_operations proc_pid_smaps_op = {
871 .start = m_start,
872 .next = m_next,
873 .stop = m_stop,
874 .show = show_pid_smap
875 };
876
877 static const struct seq_operations proc_tid_smaps_op = {
878 .start = m_start,
879 .next = m_next,
880 .stop = m_stop,
881 .show = show_tid_smap
882 };
883
884 static int pid_smaps_open(struct inode *inode, struct file *file)
885 {
886 return do_maps_open(inode, file, &proc_pid_smaps_op);
887 }
888
889 static int pid_smaps_rollup_open(struct inode *inode, struct file *file)
890 {
891 struct seq_file *seq;
892 struct proc_maps_private *priv;
893 int ret = do_maps_open(inode, file, &proc_pid_smaps_op);
894
895 if (ret < 0)
896 return ret;
897 seq = file->private_data;
898 priv = seq->private;
899 priv->rollup = kzalloc(sizeof(*priv->rollup), GFP_KERNEL);
900 if (!priv->rollup) {
901 proc_map_release(inode, file);
902 return -ENOMEM;
903 }
904 priv->rollup->first = true;
905 return 0;
906 }
907
908 static int tid_smaps_open(struct inode *inode, struct file *file)
909 {
910 return do_maps_open(inode, file, &proc_tid_smaps_op);
911 }
912
913 const struct file_operations proc_pid_smaps_operations = {
914 .open = pid_smaps_open,
915 .read = seq_read,
916 .llseek = seq_lseek,
917 .release = proc_map_release,
918 };
919
920 const struct file_operations proc_pid_smaps_rollup_operations = {
921 .open = pid_smaps_rollup_open,
922 .read = seq_read,
923 .llseek = seq_lseek,
924 .release = proc_map_release,
925 };
926
927 const struct file_operations proc_tid_smaps_operations = {
928 .open = tid_smaps_open,
929 .read = seq_read,
930 .llseek = seq_lseek,
931 .release = proc_map_release,
932 };
933
934 enum clear_refs_types {
935 CLEAR_REFS_ALL = 1,
936 CLEAR_REFS_ANON,
937 CLEAR_REFS_MAPPED,
938 CLEAR_REFS_SOFT_DIRTY,
939 CLEAR_REFS_MM_HIWATER_RSS,
940 CLEAR_REFS_LAST,
941 };
942
943 struct clear_refs_private {
944 enum clear_refs_types type;
945 };
946
947 #ifdef CONFIG_MEM_SOFT_DIRTY
948 static inline void clear_soft_dirty(struct vm_area_struct *vma,
949 unsigned long addr, pte_t *pte)
950 {
951 /*
952 * The soft-dirty tracker uses #PF-s to catch writes
953 * to pages, so write-protect the pte as well. See the
954 * Documentation/vm/soft-dirty.txt for full description
955 * of how soft-dirty works.
956 */
957 pte_t ptent = *pte;
958
959 if (pte_present(ptent)) {
960 ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
961 ptent = pte_wrprotect(ptent);
962 ptent = pte_clear_soft_dirty(ptent);
963 ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
964 } else if (is_swap_pte(ptent)) {
965 ptent = pte_swp_clear_soft_dirty(ptent);
966 set_pte_at(vma->vm_mm, addr, pte, ptent);
967 }
968 }
969 #else
970 static inline void clear_soft_dirty(struct vm_area_struct *vma,
971 unsigned long addr, pte_t *pte)
972 {
973 }
974 #endif
975
976 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
977 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
978 unsigned long addr, pmd_t *pmdp)
979 {
980 pmd_t pmd = *pmdp;
981
982 if (pmd_present(pmd)) {
983 /* See comment in change_huge_pmd() */
984 pmdp_invalidate(vma, addr, pmdp);
985 if (pmd_dirty(*pmdp))
986 pmd = pmd_mkdirty(pmd);
987 if (pmd_young(*pmdp))
988 pmd = pmd_mkyoung(pmd);
989
990 pmd = pmd_wrprotect(pmd);
991 pmd = pmd_clear_soft_dirty(pmd);
992
993 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
994 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
995 pmd = pmd_swp_clear_soft_dirty(pmd);
996 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
997 }
998 }
999 #else
1000 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1001 unsigned long addr, pmd_t *pmdp)
1002 {
1003 }
1004 #endif
1005
1006 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1007 unsigned long end, struct mm_walk *walk)
1008 {
1009 struct clear_refs_private *cp = walk->private;
1010 struct vm_area_struct *vma = walk->vma;
1011 pte_t *pte, ptent;
1012 spinlock_t *ptl;
1013 struct page *page;
1014
1015 ptl = pmd_trans_huge_lock(pmd, vma);
1016 if (ptl) {
1017 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1018 clear_soft_dirty_pmd(vma, addr, pmd);
1019 goto out;
1020 }
1021
1022 if (!pmd_present(*pmd))
1023 goto out;
1024
1025 page = pmd_page(*pmd);
1026
1027 /* Clear accessed and referenced bits. */
1028 pmdp_test_and_clear_young(vma, addr, pmd);
1029 test_and_clear_page_young(page);
1030 ClearPageReferenced(page);
1031 out:
1032 spin_unlock(ptl);
1033 return 0;
1034 }
1035
1036 if (pmd_trans_unstable(pmd))
1037 return 0;
1038
1039 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1040 for (; addr != end; pte++, addr += PAGE_SIZE) {
1041 ptent = *pte;
1042
1043 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1044 clear_soft_dirty(vma, addr, pte);
1045 continue;
1046 }
1047
1048 if (!pte_present(ptent))
1049 continue;
1050
1051 page = vm_normal_page(vma, addr, ptent);
1052 if (!page)
1053 continue;
1054
1055 /* Clear accessed and referenced bits. */
1056 ptep_test_and_clear_young(vma, addr, pte);
1057 test_and_clear_page_young(page);
1058 ClearPageReferenced(page);
1059 }
1060 pte_unmap_unlock(pte - 1, ptl);
1061 cond_resched();
1062 return 0;
1063 }
1064
1065 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1066 struct mm_walk *walk)
1067 {
1068 struct clear_refs_private *cp = walk->private;
1069 struct vm_area_struct *vma = walk->vma;
1070
1071 if (vma->vm_flags & VM_PFNMAP)
1072 return 1;
1073
1074 /*
1075 * Writing 1 to /proc/pid/clear_refs affects all pages.
1076 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1077 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1078 * Writing 4 to /proc/pid/clear_refs affects all pages.
1079 */
1080 if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1081 return 1;
1082 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1083 return 1;
1084 return 0;
1085 }
1086
1087 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1088 size_t count, loff_t *ppos)
1089 {
1090 struct task_struct *task;
1091 char buffer[PROC_NUMBUF];
1092 struct mm_struct *mm;
1093 struct vm_area_struct *vma;
1094 enum clear_refs_types type;
1095 struct mmu_gather tlb;
1096 int itype;
1097 int rv;
1098
1099 memset(buffer, 0, sizeof(buffer));
1100 if (count > sizeof(buffer) - 1)
1101 count = sizeof(buffer) - 1;
1102 if (copy_from_user(buffer, buf, count))
1103 return -EFAULT;
1104 rv = kstrtoint(strstrip(buffer), 10, &itype);
1105 if (rv < 0)
1106 return rv;
1107 type = (enum clear_refs_types)itype;
1108 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1109 return -EINVAL;
1110
1111 task = get_proc_task(file_inode(file));
1112 if (!task)
1113 return -ESRCH;
1114 mm = get_task_mm(task);
1115 if (mm) {
1116 struct clear_refs_private cp = {
1117 .type = type,
1118 };
1119 struct mm_walk clear_refs_walk = {
1120 .pmd_entry = clear_refs_pte_range,
1121 .test_walk = clear_refs_test_walk,
1122 .mm = mm,
1123 .private = &cp,
1124 };
1125
1126 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1127 if (down_write_killable(&mm->mmap_sem)) {
1128 count = -EINTR;
1129 goto out_mm;
1130 }
1131
1132 /*
1133 * Writing 5 to /proc/pid/clear_refs resets the peak
1134 * resident set size to this mm's current rss value.
1135 */
1136 reset_mm_hiwater_rss(mm);
1137 up_write(&mm->mmap_sem);
1138 goto out_mm;
1139 }
1140
1141 down_read(&mm->mmap_sem);
1142 tlb_gather_mmu(&tlb, mm, 0, -1);
1143 if (type == CLEAR_REFS_SOFT_DIRTY) {
1144 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1145 if (!(vma->vm_flags & VM_SOFTDIRTY))
1146 continue;
1147 up_read(&mm->mmap_sem);
1148 if (down_write_killable(&mm->mmap_sem)) {
1149 count = -EINTR;
1150 goto out_mm;
1151 }
1152 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1153 vma->vm_flags &= ~VM_SOFTDIRTY;
1154 vma_set_page_prot(vma);
1155 }
1156 downgrade_write(&mm->mmap_sem);
1157 break;
1158 }
1159 mmu_notifier_invalidate_range_start(mm, 0, -1);
1160 }
1161 walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1162 if (type == CLEAR_REFS_SOFT_DIRTY)
1163 mmu_notifier_invalidate_range_end(mm, 0, -1);
1164 tlb_finish_mmu(&tlb, 0, -1);
1165 up_read(&mm->mmap_sem);
1166 out_mm:
1167 mmput(mm);
1168 }
1169 put_task_struct(task);
1170
1171 return count;
1172 }
1173
1174 const struct file_operations proc_clear_refs_operations = {
1175 .write = clear_refs_write,
1176 .llseek = noop_llseek,
1177 };
1178
1179 typedef struct {
1180 u64 pme;
1181 } pagemap_entry_t;
1182
1183 struct pagemapread {
1184 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */
1185 pagemap_entry_t *buffer;
1186 bool show_pfn;
1187 };
1188
1189 #define PAGEMAP_WALK_SIZE (PMD_SIZE)
1190 #define PAGEMAP_WALK_MASK (PMD_MASK)
1191
1192 #define PM_ENTRY_BYTES sizeof(pagemap_entry_t)
1193 #define PM_PFRAME_BITS 55
1194 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1195 #define PM_SOFT_DIRTY BIT_ULL(55)
1196 #define PM_MMAP_EXCLUSIVE BIT_ULL(56)
1197 #define PM_FILE BIT_ULL(61)
1198 #define PM_SWAP BIT_ULL(62)
1199 #define PM_PRESENT BIT_ULL(63)
1200
1201 #define PM_END_OF_BUFFER 1
1202
1203 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1204 {
1205 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1206 }
1207
1208 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1209 struct pagemapread *pm)
1210 {
1211 pm->buffer[pm->pos++] = *pme;
1212 if (pm->pos >= pm->len)
1213 return PM_END_OF_BUFFER;
1214 return 0;
1215 }
1216
1217 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1218 struct mm_walk *walk)
1219 {
1220 struct pagemapread *pm = walk->private;
1221 unsigned long addr = start;
1222 int err = 0;
1223
1224 while (addr < end) {
1225 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1226 pagemap_entry_t pme = make_pme(0, 0);
1227 /* End of address space hole, which we mark as non-present. */
1228 unsigned long hole_end;
1229
1230 if (vma)
1231 hole_end = min(end, vma->vm_start);
1232 else
1233 hole_end = end;
1234
1235 for (; addr < hole_end; addr += PAGE_SIZE) {
1236 err = add_to_pagemap(addr, &pme, pm);
1237 if (err)
1238 goto out;
1239 }
1240
1241 if (!vma)
1242 break;
1243
1244 /* Addresses in the VMA. */
1245 if (vma->vm_flags & VM_SOFTDIRTY)
1246 pme = make_pme(0, PM_SOFT_DIRTY);
1247 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1248 err = add_to_pagemap(addr, &pme, pm);
1249 if (err)
1250 goto out;
1251 }
1252 }
1253 out:
1254 return err;
1255 }
1256
1257 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1258 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1259 {
1260 u64 frame = 0, flags = 0;
1261 struct page *page = NULL;
1262
1263 if (pte_present(pte)) {
1264 if (pm->show_pfn)
1265 frame = pte_pfn(pte);
1266 flags |= PM_PRESENT;
1267 page = _vm_normal_page(vma, addr, pte, true);
1268 if (pte_soft_dirty(pte))
1269 flags |= PM_SOFT_DIRTY;
1270 } else if (is_swap_pte(pte)) {
1271 swp_entry_t entry;
1272 if (pte_swp_soft_dirty(pte))
1273 flags |= PM_SOFT_DIRTY;
1274 entry = pte_to_swp_entry(pte);
1275 frame = swp_type(entry) |
1276 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1277 flags |= PM_SWAP;
1278 if (is_migration_entry(entry))
1279 page = migration_entry_to_page(entry);
1280
1281 if (is_device_private_entry(entry))
1282 page = device_private_entry_to_page(entry);
1283 }
1284
1285 if (page && !PageAnon(page))
1286 flags |= PM_FILE;
1287 if (page && page_mapcount(page) == 1)
1288 flags |= PM_MMAP_EXCLUSIVE;
1289 if (vma->vm_flags & VM_SOFTDIRTY)
1290 flags |= PM_SOFT_DIRTY;
1291
1292 return make_pme(frame, flags);
1293 }
1294
1295 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1296 struct mm_walk *walk)
1297 {
1298 struct vm_area_struct *vma = walk->vma;
1299 struct pagemapread *pm = walk->private;
1300 spinlock_t *ptl;
1301 pte_t *pte, *orig_pte;
1302 int err = 0;
1303
1304 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1305 ptl = pmd_trans_huge_lock(pmdp, vma);
1306 if (ptl) {
1307 u64 flags = 0, frame = 0;
1308 pmd_t pmd = *pmdp;
1309 struct page *page = NULL;
1310
1311 if (vma->vm_flags & VM_SOFTDIRTY)
1312 flags |= PM_SOFT_DIRTY;
1313
1314 if (pmd_present(pmd)) {
1315 page = pmd_page(pmd);
1316
1317 flags |= PM_PRESENT;
1318 if (pmd_soft_dirty(pmd))
1319 flags |= PM_SOFT_DIRTY;
1320 if (pm->show_pfn)
1321 frame = pmd_pfn(pmd) +
1322 ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1323 }
1324 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1325 else if (is_swap_pmd(pmd)) {
1326 swp_entry_t entry = pmd_to_swp_entry(pmd);
1327
1328 frame = swp_type(entry) |
1329 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1330 flags |= PM_SWAP;
1331 if (pmd_swp_soft_dirty(pmd))
1332 flags |= PM_SOFT_DIRTY;
1333 VM_BUG_ON(!is_pmd_migration_entry(pmd));
1334 page = migration_entry_to_page(entry);
1335 }
1336 #endif
1337
1338 if (page && page_mapcount(page) == 1)
1339 flags |= PM_MMAP_EXCLUSIVE;
1340
1341 for (; addr != end; addr += PAGE_SIZE) {
1342 pagemap_entry_t pme = make_pme(frame, flags);
1343
1344 err = add_to_pagemap(addr, &pme, pm);
1345 if (err)
1346 break;
1347 if (pm->show_pfn && (flags & PM_PRESENT))
1348 frame++;
1349 }
1350 spin_unlock(ptl);
1351 return err;
1352 }
1353
1354 if (pmd_trans_unstable(pmdp))
1355 return 0;
1356 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1357
1358 /*
1359 * We can assume that @vma always points to a valid one and @end never
1360 * goes beyond vma->vm_end.
1361 */
1362 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1363 for (; addr < end; pte++, addr += PAGE_SIZE) {
1364 pagemap_entry_t pme;
1365
1366 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1367 err = add_to_pagemap(addr, &pme, pm);
1368 if (err)
1369 break;
1370 }
1371 pte_unmap_unlock(orig_pte, ptl);
1372
1373 cond_resched();
1374
1375 return err;
1376 }
1377
1378 #ifdef CONFIG_HUGETLB_PAGE
1379 /* This function walks within one hugetlb entry in the single call */
1380 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1381 unsigned long addr, unsigned long end,
1382 struct mm_walk *walk)
1383 {
1384 struct pagemapread *pm = walk->private;
1385 struct vm_area_struct *vma = walk->vma;
1386 u64 flags = 0, frame = 0;
1387 int err = 0;
1388 pte_t pte;
1389
1390 if (vma->vm_flags & VM_SOFTDIRTY)
1391 flags |= PM_SOFT_DIRTY;
1392
1393 pte = huge_ptep_get(ptep);
1394 if (pte_present(pte)) {
1395 struct page *page = pte_page(pte);
1396
1397 if (!PageAnon(page))
1398 flags |= PM_FILE;
1399
1400 if (page_mapcount(page) == 1)
1401 flags |= PM_MMAP_EXCLUSIVE;
1402
1403 flags |= PM_PRESENT;
1404 if (pm->show_pfn)
1405 frame = pte_pfn(pte) +
1406 ((addr & ~hmask) >> PAGE_SHIFT);
1407 }
1408
1409 for (; addr != end; addr += PAGE_SIZE) {
1410 pagemap_entry_t pme = make_pme(frame, flags);
1411
1412 err = add_to_pagemap(addr, &pme, pm);
1413 if (err)
1414 return err;
1415 if (pm->show_pfn && (flags & PM_PRESENT))
1416 frame++;
1417 }
1418
1419 cond_resched();
1420
1421 return err;
1422 }
1423 #endif /* HUGETLB_PAGE */
1424
1425 /*
1426 * /proc/pid/pagemap - an array mapping virtual pages to pfns
1427 *
1428 * For each page in the address space, this file contains one 64-bit entry
1429 * consisting of the following:
1430 *
1431 * Bits 0-54 page frame number (PFN) if present
1432 * Bits 0-4 swap type if swapped
1433 * Bits 5-54 swap offset if swapped
1434 * Bit 55 pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1435 * Bit 56 page exclusively mapped
1436 * Bits 57-60 zero
1437 * Bit 61 page is file-page or shared-anon
1438 * Bit 62 page swapped
1439 * Bit 63 page present
1440 *
1441 * If the page is not present but in swap, then the PFN contains an
1442 * encoding of the swap file number and the page's offset into the
1443 * swap. Unmapped pages return a null PFN. This allows determining
1444 * precisely which pages are mapped (or in swap) and comparing mapped
1445 * pages between processes.
1446 *
1447 * Efficient users of this interface will use /proc/pid/maps to
1448 * determine which areas of memory are actually mapped and llseek to
1449 * skip over unmapped regions.
1450 */
1451 static ssize_t pagemap_read(struct file *file, char __user *buf,
1452 size_t count, loff_t *ppos)
1453 {
1454 struct mm_struct *mm = file->private_data;
1455 struct pagemapread pm;
1456 struct mm_walk pagemap_walk = {};
1457 unsigned long src;
1458 unsigned long svpfn;
1459 unsigned long start_vaddr;
1460 unsigned long end_vaddr;
1461 int ret = 0, copied = 0;
1462
1463 if (!mm || !mmget_not_zero(mm))
1464 goto out;
1465
1466 ret = -EINVAL;
1467 /* file position must be aligned */
1468 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1469 goto out_mm;
1470
1471 ret = 0;
1472 if (!count)
1473 goto out_mm;
1474
1475 /* do not disclose physical addresses: attack vector */
1476 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1477
1478 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1479 pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_KERNEL);
1480 ret = -ENOMEM;
1481 if (!pm.buffer)
1482 goto out_mm;
1483
1484 pagemap_walk.pmd_entry = pagemap_pmd_range;
1485 pagemap_walk.pte_hole = pagemap_pte_hole;
1486 #ifdef CONFIG_HUGETLB_PAGE
1487 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1488 #endif
1489 pagemap_walk.mm = mm;
1490 pagemap_walk.private = &pm;
1491
1492 src = *ppos;
1493 svpfn = src / PM_ENTRY_BYTES;
1494 start_vaddr = svpfn << PAGE_SHIFT;
1495 end_vaddr = mm->task_size;
1496
1497 /* watch out for wraparound */
1498 if (svpfn > mm->task_size >> PAGE_SHIFT)
1499 start_vaddr = end_vaddr;
1500
1501 /*
1502 * The odds are that this will stop walking way
1503 * before end_vaddr, because the length of the
1504 * user buffer is tracked in "pm", and the walk
1505 * will stop when we hit the end of the buffer.
1506 */
1507 ret = 0;
1508 while (count && (start_vaddr < end_vaddr)) {
1509 int len;
1510 unsigned long end;
1511
1512 pm.pos = 0;
1513 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1514 /* overflow ? */
1515 if (end < start_vaddr || end > end_vaddr)
1516 end = end_vaddr;
1517 down_read(&mm->mmap_sem);
1518 ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1519 up_read(&mm->mmap_sem);
1520 start_vaddr = end;
1521
1522 len = min(count, PM_ENTRY_BYTES * pm.pos);
1523 if (copy_to_user(buf, pm.buffer, len)) {
1524 ret = -EFAULT;
1525 goto out_free;
1526 }
1527 copied += len;
1528 buf += len;
1529 count -= len;
1530 }
1531 *ppos += copied;
1532 if (!ret || ret == PM_END_OF_BUFFER)
1533 ret = copied;
1534
1535 out_free:
1536 kfree(pm.buffer);
1537 out_mm:
1538 mmput(mm);
1539 out:
1540 return ret;
1541 }
1542
1543 static int pagemap_open(struct inode *inode, struct file *file)
1544 {
1545 struct mm_struct *mm;
1546
1547 mm = proc_mem_open(inode, PTRACE_MODE_READ);
1548 if (IS_ERR(mm))
1549 return PTR_ERR(mm);
1550 file->private_data = mm;
1551 return 0;
1552 }
1553
1554 static int pagemap_release(struct inode *inode, struct file *file)
1555 {
1556 struct mm_struct *mm = file->private_data;
1557
1558 if (mm)
1559 mmdrop(mm);
1560 return 0;
1561 }
1562
1563 const struct file_operations proc_pagemap_operations = {
1564 .llseek = mem_lseek, /* borrow this */
1565 .read = pagemap_read,
1566 .open = pagemap_open,
1567 .release = pagemap_release,
1568 };
1569 #endif /* CONFIG_PROC_PAGE_MONITOR */
1570
1571 #ifdef CONFIG_NUMA
1572
1573 struct numa_maps {
1574 unsigned long pages;
1575 unsigned long anon;
1576 unsigned long active;
1577 unsigned long writeback;
1578 unsigned long mapcount_max;
1579 unsigned long dirty;
1580 unsigned long swapcache;
1581 unsigned long node[MAX_NUMNODES];
1582 };
1583
1584 struct numa_maps_private {
1585 struct proc_maps_private proc_maps;
1586 struct numa_maps md;
1587 };
1588
1589 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1590 unsigned long nr_pages)
1591 {
1592 int count = page_mapcount(page);
1593
1594 md->pages += nr_pages;
1595 if (pte_dirty || PageDirty(page))
1596 md->dirty += nr_pages;
1597
1598 if (PageSwapCache(page))
1599 md->swapcache += nr_pages;
1600
1601 if (PageActive(page) || PageUnevictable(page))
1602 md->active += nr_pages;
1603
1604 if (PageWriteback(page))
1605 md->writeback += nr_pages;
1606
1607 if (PageAnon(page))
1608 md->anon += nr_pages;
1609
1610 if (count > md->mapcount_max)
1611 md->mapcount_max = count;
1612
1613 md->node[page_to_nid(page)] += nr_pages;
1614 }
1615
1616 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1617 unsigned long addr)
1618 {
1619 struct page *page;
1620 int nid;
1621
1622 if (!pte_present(pte))
1623 return NULL;
1624
1625 page = vm_normal_page(vma, addr, pte);
1626 if (!page)
1627 return NULL;
1628
1629 if (PageReserved(page))
1630 return NULL;
1631
1632 nid = page_to_nid(page);
1633 if (!node_isset(nid, node_states[N_MEMORY]))
1634 return NULL;
1635
1636 return page;
1637 }
1638
1639 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1640 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1641 struct vm_area_struct *vma,
1642 unsigned long addr)
1643 {
1644 struct page *page;
1645 int nid;
1646
1647 if (!pmd_present(pmd))
1648 return NULL;
1649
1650 page = vm_normal_page_pmd(vma, addr, pmd);
1651 if (!page)
1652 return NULL;
1653
1654 if (PageReserved(page))
1655 return NULL;
1656
1657 nid = page_to_nid(page);
1658 if (!node_isset(nid, node_states[N_MEMORY]))
1659 return NULL;
1660
1661 return page;
1662 }
1663 #endif
1664
1665 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1666 unsigned long end, struct mm_walk *walk)
1667 {
1668 struct numa_maps *md = walk->private;
1669 struct vm_area_struct *vma = walk->vma;
1670 spinlock_t *ptl;
1671 pte_t *orig_pte;
1672 pte_t *pte;
1673
1674 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1675 ptl = pmd_trans_huge_lock(pmd, vma);
1676 if (ptl) {
1677 struct page *page;
1678
1679 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1680 if (page)
1681 gather_stats(page, md, pmd_dirty(*pmd),
1682 HPAGE_PMD_SIZE/PAGE_SIZE);
1683 spin_unlock(ptl);
1684 return 0;
1685 }
1686
1687 if (pmd_trans_unstable(pmd))
1688 return 0;
1689 #endif
1690 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1691 do {
1692 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1693 if (!page)
1694 continue;
1695 gather_stats(page, md, pte_dirty(*pte), 1);
1696
1697 } while (pte++, addr += PAGE_SIZE, addr != end);
1698 pte_unmap_unlock(orig_pte, ptl);
1699 cond_resched();
1700 return 0;
1701 }
1702 #ifdef CONFIG_HUGETLB_PAGE
1703 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1704 unsigned long addr, unsigned long end, struct mm_walk *walk)
1705 {
1706 pte_t huge_pte = huge_ptep_get(pte);
1707 struct numa_maps *md;
1708 struct page *page;
1709
1710 if (!pte_present(huge_pte))
1711 return 0;
1712
1713 page = pte_page(huge_pte);
1714 if (!page)
1715 return 0;
1716
1717 md = walk->private;
1718 gather_stats(page, md, pte_dirty(huge_pte), 1);
1719 return 0;
1720 }
1721
1722 #else
1723 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1724 unsigned long addr, unsigned long end, struct mm_walk *walk)
1725 {
1726 return 0;
1727 }
1728 #endif
1729
1730 /*
1731 * Display pages allocated per node and memory policy via /proc.
1732 */
1733 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1734 {
1735 struct numa_maps_private *numa_priv = m->private;
1736 struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1737 struct vm_area_struct *vma = v;
1738 struct numa_maps *md = &numa_priv->md;
1739 struct file *file = vma->vm_file;
1740 struct mm_struct *mm = vma->vm_mm;
1741 struct mm_walk walk = {
1742 .hugetlb_entry = gather_hugetlb_stats,
1743 .pmd_entry = gather_pte_stats,
1744 .private = md,
1745 .mm = mm,
1746 };
1747 struct mempolicy *pol;
1748 char buffer[64];
1749 int nid;
1750
1751 if (!mm)
1752 return 0;
1753
1754 /* Ensure we start with an empty set of numa_maps statistics. */
1755 memset(md, 0, sizeof(*md));
1756
1757 pol = __get_vma_policy(vma, vma->vm_start);
1758 if (pol) {
1759 mpol_to_str(buffer, sizeof(buffer), pol);
1760 mpol_cond_put(pol);
1761 } else {
1762 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1763 }
1764
1765 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1766
1767 if (file) {
1768 seq_puts(m, " file=");
1769 seq_file_path(m, file, "\n\t= ");
1770 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1771 seq_puts(m, " heap");
1772 } else if (is_stack(vma)) {
1773 seq_puts(m, " stack");
1774 }
1775
1776 if (is_vm_hugetlb_page(vma))
1777 seq_puts(m, " huge");
1778
1779 /* mmap_sem is held by m_start */
1780 walk_page_vma(vma, &walk);
1781
1782 if (!md->pages)
1783 goto out;
1784
1785 if (md->anon)
1786 seq_printf(m, " anon=%lu", md->anon);
1787
1788 if (md->dirty)
1789 seq_printf(m, " dirty=%lu", md->dirty);
1790
1791 if (md->pages != md->anon && md->pages != md->dirty)
1792 seq_printf(m, " mapped=%lu", md->pages);
1793
1794 if (md->mapcount_max > 1)
1795 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1796
1797 if (md->swapcache)
1798 seq_printf(m, " swapcache=%lu", md->swapcache);
1799
1800 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1801 seq_printf(m, " active=%lu", md->active);
1802
1803 if (md->writeback)
1804 seq_printf(m, " writeback=%lu", md->writeback);
1805
1806 for_each_node_state(nid, N_MEMORY)
1807 if (md->node[nid])
1808 seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1809
1810 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1811 out:
1812 seq_putc(m, '\n');
1813 m_cache_vma(m, vma);
1814 return 0;
1815 }
1816
1817 static int show_pid_numa_map(struct seq_file *m, void *v)
1818 {
1819 return show_numa_map(m, v, 1);
1820 }
1821
1822 static int show_tid_numa_map(struct seq_file *m, void *v)
1823 {
1824 return show_numa_map(m, v, 0);
1825 }
1826
1827 static const struct seq_operations proc_pid_numa_maps_op = {
1828 .start = m_start,
1829 .next = m_next,
1830 .stop = m_stop,
1831 .show = show_pid_numa_map,
1832 };
1833
1834 static const struct seq_operations proc_tid_numa_maps_op = {
1835 .start = m_start,
1836 .next = m_next,
1837 .stop = m_stop,
1838 .show = show_tid_numa_map,
1839 };
1840
1841 static int numa_maps_open(struct inode *inode, struct file *file,
1842 const struct seq_operations *ops)
1843 {
1844 return proc_maps_open(inode, file, ops,
1845 sizeof(struct numa_maps_private));
1846 }
1847
1848 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1849 {
1850 return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1851 }
1852
1853 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1854 {
1855 return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1856 }
1857
1858 const struct file_operations proc_pid_numa_maps_operations = {
1859 .open = pid_numa_maps_open,
1860 .read = seq_read,
1861 .llseek = seq_lseek,
1862 .release = proc_map_release,
1863 };
1864
1865 const struct file_operations proc_tid_numa_maps_operations = {
1866 .open = tid_numa_maps_open,
1867 .read = seq_read,
1868 .llseek = seq_lseek,
1869 .release = proc_map_release,
1870 };
1871 #endif /* CONFIG_NUMA */
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