846d43df3fdf18df3fe7bddfd83ee8630a36a7db
[linux-block.git] / fs / proc / task_mmu.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/pagewalk.h>
3 #include <linux/vmacache.h>
4 #include <linux/hugetlb.h>
5 #include <linux/huge_mm.h>
6 #include <linux/mount.h>
7 #include <linux/seq_file.h>
8 #include <linux/highmem.h>
9 #include <linux/ptrace.h>
10 #include <linux/slab.h>
11 #include <linux/pagemap.h>
12 #include <linux/mempolicy.h>
13 #include <linux/rmap.h>
14 #include <linux/swap.h>
15 #include <linux/sched/mm.h>
16 #include <linux/swapops.h>
17 #include <linux/mmu_notifier.h>
18 #include <linux/page_idle.h>
19 #include <linux/shmem_fs.h>
20 #include <linux/uaccess.h>
21 #include <linux/pkeys.h>
22
23 #include <asm/elf.h>
24 #include <asm/tlb.h>
25 #include <asm/tlbflush.h>
26 #include "internal.h"
27
28 #define SEQ_PUT_DEC(str, val) \
29                 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
30 void task_mem(struct seq_file *m, struct mm_struct *mm)
31 {
32         unsigned long text, lib, swap, anon, file, shmem;
33         unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
34
35         anon = get_mm_counter(mm, MM_ANONPAGES);
36         file = get_mm_counter(mm, MM_FILEPAGES);
37         shmem = get_mm_counter(mm, MM_SHMEMPAGES);
38
39         /*
40          * Note: to minimize their overhead, mm maintains hiwater_vm and
41          * hiwater_rss only when about to *lower* total_vm or rss.  Any
42          * collector of these hiwater stats must therefore get total_vm
43          * and rss too, which will usually be the higher.  Barriers? not
44          * worth the effort, such snapshots can always be inconsistent.
45          */
46         hiwater_vm = total_vm = mm->total_vm;
47         if (hiwater_vm < mm->hiwater_vm)
48                 hiwater_vm = mm->hiwater_vm;
49         hiwater_rss = total_rss = anon + file + shmem;
50         if (hiwater_rss < mm->hiwater_rss)
51                 hiwater_rss = mm->hiwater_rss;
52
53         /* split executable areas between text and lib */
54         text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
55         text = min(text, mm->exec_vm << PAGE_SHIFT);
56         lib = (mm->exec_vm << PAGE_SHIFT) - text;
57
58         swap = get_mm_counter(mm, MM_SWAPENTS);
59         SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
60         SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
61         SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
62         SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
63         SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
64         SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
65         SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
66         SEQ_PUT_DEC(" kB\nRssFile:\t", file);
67         SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
68         SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
69         SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
70         seq_put_decimal_ull_width(m,
71                     " kB\nVmExe:\t", text >> 10, 8);
72         seq_put_decimal_ull_width(m,
73                     " kB\nVmLib:\t", lib >> 10, 8);
74         seq_put_decimal_ull_width(m,
75                     " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
76         SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
77         seq_puts(m, " kB\n");
78         hugetlb_report_usage(m, mm);
79 }
80 #undef SEQ_PUT_DEC
81
82 unsigned long task_vsize(struct mm_struct *mm)
83 {
84         return PAGE_SIZE * mm->total_vm;
85 }
86
87 unsigned long task_statm(struct mm_struct *mm,
88                          unsigned long *shared, unsigned long *text,
89                          unsigned long *data, unsigned long *resident)
90 {
91         *shared = get_mm_counter(mm, MM_FILEPAGES) +
92                         get_mm_counter(mm, MM_SHMEMPAGES);
93         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
94                                                                 >> PAGE_SHIFT;
95         *data = mm->data_vm + mm->stack_vm;
96         *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
97         return mm->total_vm;
98 }
99
100 #ifdef CONFIG_NUMA
101 /*
102  * Save get_task_policy() for show_numa_map().
103  */
104 static void hold_task_mempolicy(struct proc_maps_private *priv)
105 {
106         struct task_struct *task = priv->task;
107
108         task_lock(task);
109         priv->task_mempolicy = get_task_policy(task);
110         mpol_get(priv->task_mempolicy);
111         task_unlock(task);
112 }
113 static void release_task_mempolicy(struct proc_maps_private *priv)
114 {
115         mpol_put(priv->task_mempolicy);
116 }
117 #else
118 static void hold_task_mempolicy(struct proc_maps_private *priv)
119 {
120 }
121 static void release_task_mempolicy(struct proc_maps_private *priv)
122 {
123 }
124 #endif
125
126 static void *m_start(struct seq_file *m, loff_t *ppos)
127 {
128         struct proc_maps_private *priv = m->private;
129         unsigned long last_addr = *ppos;
130         struct mm_struct *mm;
131         struct vm_area_struct *vma;
132
133         /* See m_next(). Zero at the start or after lseek. */
134         if (last_addr == -1UL)
135                 return NULL;
136
137         priv->task = get_proc_task(priv->inode);
138         if (!priv->task)
139                 return ERR_PTR(-ESRCH);
140
141         mm = priv->mm;
142         if (!mm || !mmget_not_zero(mm)) {
143                 put_task_struct(priv->task);
144                 priv->task = NULL;
145                 return NULL;
146         }
147
148         if (mmap_read_lock_killable(mm)) {
149                 mmput(mm);
150                 put_task_struct(priv->task);
151                 priv->task = NULL;
152                 return ERR_PTR(-EINTR);
153         }
154
155         hold_task_mempolicy(priv);
156         priv->tail_vma = get_gate_vma(mm);
157
158         vma = find_vma(mm, last_addr);
159         if (vma)
160                 return vma;
161
162         return priv->tail_vma;
163 }
164
165 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
166 {
167         struct proc_maps_private *priv = m->private;
168         struct vm_area_struct *next, *vma = v;
169
170         if (vma == priv->tail_vma)
171                 next = NULL;
172         else if (vma->vm_next)
173                 next = vma->vm_next;
174         else
175                 next = priv->tail_vma;
176
177         *ppos = next ? next->vm_start : -1UL;
178
179         return next;
180 }
181
182 static void m_stop(struct seq_file *m, void *v)
183 {
184         struct proc_maps_private *priv = m->private;
185         struct mm_struct *mm = priv->mm;
186
187         if (!priv->task)
188                 return;
189
190         release_task_mempolicy(priv);
191         mmap_read_unlock(mm);
192         mmput(mm);
193         put_task_struct(priv->task);
194         priv->task = NULL;
195 }
196
197 static int proc_maps_open(struct inode *inode, struct file *file,
198                         const struct seq_operations *ops, int psize)
199 {
200         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
201
202         if (!priv)
203                 return -ENOMEM;
204
205         priv->inode = inode;
206         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
207         if (IS_ERR(priv->mm)) {
208                 int err = PTR_ERR(priv->mm);
209
210                 seq_release_private(inode, file);
211                 return err;
212         }
213
214         return 0;
215 }
216
217 static int proc_map_release(struct inode *inode, struct file *file)
218 {
219         struct seq_file *seq = file->private_data;
220         struct proc_maps_private *priv = seq->private;
221
222         if (priv->mm)
223                 mmdrop(priv->mm);
224
225         return seq_release_private(inode, file);
226 }
227
228 static int do_maps_open(struct inode *inode, struct file *file,
229                         const struct seq_operations *ops)
230 {
231         return proc_maps_open(inode, file, ops,
232                                 sizeof(struct proc_maps_private));
233 }
234
235 /*
236  * Indicate if the VMA is a stack for the given task; for
237  * /proc/PID/maps that is the stack of the main task.
238  */
239 static int is_stack(struct vm_area_struct *vma)
240 {
241         /*
242          * We make no effort to guess what a given thread considers to be
243          * its "stack".  It's not even well-defined for programs written
244          * languages like Go.
245          */
246         return vma->vm_start <= vma->vm_mm->start_stack &&
247                 vma->vm_end >= vma->vm_mm->start_stack;
248 }
249
250 static void show_vma_header_prefix(struct seq_file *m,
251                                    unsigned long start, unsigned long end,
252                                    vm_flags_t flags, unsigned long long pgoff,
253                                    dev_t dev, unsigned long ino)
254 {
255         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
256         seq_put_hex_ll(m, NULL, start, 8);
257         seq_put_hex_ll(m, "-", end, 8);
258         seq_putc(m, ' ');
259         seq_putc(m, flags & VM_READ ? 'r' : '-');
260         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
261         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
262         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
263         seq_put_hex_ll(m, " ", pgoff, 8);
264         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
265         seq_put_hex_ll(m, ":", MINOR(dev), 2);
266         seq_put_decimal_ull(m, " ", ino);
267         seq_putc(m, ' ');
268 }
269
270 static void
271 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
272 {
273         struct mm_struct *mm = vma->vm_mm;
274         struct file *file = vma->vm_file;
275         vm_flags_t flags = vma->vm_flags;
276         unsigned long ino = 0;
277         unsigned long long pgoff = 0;
278         unsigned long start, end;
279         dev_t dev = 0;
280         const char *name = NULL;
281
282         if (file) {
283                 struct inode *inode = file_inode(vma->vm_file);
284                 dev = inode->i_sb->s_dev;
285                 ino = inode->i_ino;
286                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
287         }
288
289         start = vma->vm_start;
290         end = vma->vm_end;
291         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
292
293         /*
294          * Print the dentry name for named mappings, and a
295          * special [heap] marker for the heap:
296          */
297         if (file) {
298                 seq_pad(m, ' ');
299                 seq_file_path(m, file, "\n");
300                 goto done;
301         }
302
303         if (vma->vm_ops && vma->vm_ops->name) {
304                 name = vma->vm_ops->name(vma);
305                 if (name)
306                         goto done;
307         }
308
309         name = arch_vma_name(vma);
310         if (!name) {
311                 if (!mm) {
312                         name = "[vdso]";
313                         goto done;
314                 }
315
316                 if (vma->vm_start <= mm->brk &&
317                     vma->vm_end >= mm->start_brk) {
318                         name = "[heap]";
319                         goto done;
320                 }
321
322                 if (is_stack(vma))
323                         name = "[stack]";
324         }
325
326 done:
327         if (name) {
328                 seq_pad(m, ' ');
329                 seq_puts(m, name);
330         }
331         seq_putc(m, '\n');
332 }
333
334 static int show_map(struct seq_file *m, void *v)
335 {
336         show_map_vma(m, v);
337         return 0;
338 }
339
340 static const struct seq_operations proc_pid_maps_op = {
341         .start  = m_start,
342         .next   = m_next,
343         .stop   = m_stop,
344         .show   = show_map
345 };
346
347 static int pid_maps_open(struct inode *inode, struct file *file)
348 {
349         return do_maps_open(inode, file, &proc_pid_maps_op);
350 }
351
352 const struct file_operations proc_pid_maps_operations = {
353         .open           = pid_maps_open,
354         .read           = seq_read,
355         .llseek         = seq_lseek,
356         .release        = proc_map_release,
357 };
358
359 /*
360  * Proportional Set Size(PSS): my share of RSS.
361  *
362  * PSS of a process is the count of pages it has in memory, where each
363  * page is divided by the number of processes sharing it.  So if a
364  * process has 1000 pages all to itself, and 1000 shared with one other
365  * process, its PSS will be 1500.
366  *
367  * To keep (accumulated) division errors low, we adopt a 64bit
368  * fixed-point pss counter to minimize division errors. So (pss >>
369  * PSS_SHIFT) would be the real byte count.
370  *
371  * A shift of 12 before division means (assuming 4K page size):
372  *      - 1M 3-user-pages add up to 8KB errors;
373  *      - supports mapcount up to 2^24, or 16M;
374  *      - supports PSS up to 2^52 bytes, or 4PB.
375  */
376 #define PSS_SHIFT 12
377
378 #ifdef CONFIG_PROC_PAGE_MONITOR
379 struct mem_size_stats {
380         unsigned long resident;
381         unsigned long shared_clean;
382         unsigned long shared_dirty;
383         unsigned long private_clean;
384         unsigned long private_dirty;
385         unsigned long referenced;
386         unsigned long anonymous;
387         unsigned long lazyfree;
388         unsigned long anonymous_thp;
389         unsigned long shmem_thp;
390         unsigned long file_thp;
391         unsigned long swap;
392         unsigned long shared_hugetlb;
393         unsigned long private_hugetlb;
394         u64 pss;
395         u64 pss_anon;
396         u64 pss_file;
397         u64 pss_shmem;
398         u64 pss_locked;
399         u64 swap_pss;
400         bool check_shmem_swap;
401 };
402
403 static void smaps_page_accumulate(struct mem_size_stats *mss,
404                 struct page *page, unsigned long size, unsigned long pss,
405                 bool dirty, bool locked, bool private)
406 {
407         mss->pss += pss;
408
409         if (PageAnon(page))
410                 mss->pss_anon += pss;
411         else if (PageSwapBacked(page))
412                 mss->pss_shmem += pss;
413         else
414                 mss->pss_file += pss;
415
416         if (locked)
417                 mss->pss_locked += pss;
418
419         if (dirty || PageDirty(page)) {
420                 if (private)
421                         mss->private_dirty += size;
422                 else
423                         mss->shared_dirty += size;
424         } else {
425                 if (private)
426                         mss->private_clean += size;
427                 else
428                         mss->shared_clean += size;
429         }
430 }
431
432 static void smaps_account(struct mem_size_stats *mss, struct page *page,
433                 bool compound, bool young, bool dirty, bool locked)
434 {
435         int i, nr = compound ? compound_nr(page) : 1;
436         unsigned long size = nr * PAGE_SIZE;
437
438         /*
439          * First accumulate quantities that depend only on |size| and the type
440          * of the compound page.
441          */
442         if (PageAnon(page)) {
443                 mss->anonymous += size;
444                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
445                         mss->lazyfree += size;
446         }
447
448         mss->resident += size;
449         /* Accumulate the size in pages that have been accessed. */
450         if (young || page_is_young(page) || PageReferenced(page))
451                 mss->referenced += size;
452
453         /*
454          * Then accumulate quantities that may depend on sharing, or that may
455          * differ page-by-page.
456          *
457          * page_count(page) == 1 guarantees the page is mapped exactly once.
458          * If any subpage of the compound page mapped with PTE it would elevate
459          * page_count().
460          */
461         if (page_count(page) == 1) {
462                 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
463                         locked, true);
464                 return;
465         }
466         for (i = 0; i < nr; i++, page++) {
467                 int mapcount = page_mapcount(page);
468                 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
469                 if (mapcount >= 2)
470                         pss /= mapcount;
471                 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
472                                       mapcount < 2);
473         }
474 }
475
476 #ifdef CONFIG_SHMEM
477 static int smaps_pte_hole(unsigned long addr, unsigned long end,
478                           __always_unused int depth, struct mm_walk *walk)
479 {
480         struct mem_size_stats *mss = walk->private;
481
482         mss->swap += shmem_partial_swap_usage(
483                         walk->vma->vm_file->f_mapping, addr, end);
484
485         return 0;
486 }
487 #else
488 #define smaps_pte_hole          NULL
489 #endif /* CONFIG_SHMEM */
490
491 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
492                 struct mm_walk *walk)
493 {
494         struct mem_size_stats *mss = walk->private;
495         struct vm_area_struct *vma = walk->vma;
496         bool locked = !!(vma->vm_flags & VM_LOCKED);
497         struct page *page = NULL;
498
499         if (pte_present(*pte)) {
500                 page = vm_normal_page(vma, addr, *pte);
501         } else if (is_swap_pte(*pte)) {
502                 swp_entry_t swpent = pte_to_swp_entry(*pte);
503
504                 if (!non_swap_entry(swpent)) {
505                         int mapcount;
506
507                         mss->swap += PAGE_SIZE;
508                         mapcount = swp_swapcount(swpent);
509                         if (mapcount >= 2) {
510                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
511
512                                 do_div(pss_delta, mapcount);
513                                 mss->swap_pss += pss_delta;
514                         } else {
515                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
516                         }
517                 } else if (is_migration_entry(swpent))
518                         page = migration_entry_to_page(swpent);
519                 else if (is_device_private_entry(swpent))
520                         page = device_private_entry_to_page(swpent);
521         } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
522                                                         && pte_none(*pte))) {
523                 page = xa_load(&vma->vm_file->f_mapping->i_pages,
524                                                 linear_page_index(vma, addr));
525                 if (xa_is_value(page))
526                         mss->swap += PAGE_SIZE;
527                 return;
528         }
529
530         if (!page)
531                 return;
532
533         smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
534 }
535
536 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
537 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
538                 struct mm_walk *walk)
539 {
540         struct mem_size_stats *mss = walk->private;
541         struct vm_area_struct *vma = walk->vma;
542         bool locked = !!(vma->vm_flags & VM_LOCKED);
543         struct page *page = NULL;
544
545         if (pmd_present(*pmd)) {
546                 /* FOLL_DUMP will return -EFAULT on huge zero page */
547                 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
548         } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
549                 swp_entry_t entry = pmd_to_swp_entry(*pmd);
550
551                 if (is_migration_entry(entry))
552                         page = migration_entry_to_page(entry);
553         }
554         if (IS_ERR_OR_NULL(page))
555                 return;
556         if (PageAnon(page))
557                 mss->anonymous_thp += HPAGE_PMD_SIZE;
558         else if (PageSwapBacked(page))
559                 mss->shmem_thp += HPAGE_PMD_SIZE;
560         else if (is_zone_device_page(page))
561                 /* pass */;
562         else
563                 mss->file_thp += HPAGE_PMD_SIZE;
564         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
565 }
566 #else
567 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
568                 struct mm_walk *walk)
569 {
570 }
571 #endif
572
573 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
574                            struct mm_walk *walk)
575 {
576         struct vm_area_struct *vma = walk->vma;
577         pte_t *pte;
578         spinlock_t *ptl;
579
580         ptl = pmd_trans_huge_lock(pmd, vma);
581         if (ptl) {
582                 smaps_pmd_entry(pmd, addr, walk);
583                 spin_unlock(ptl);
584                 goto out;
585         }
586
587         if (pmd_trans_unstable(pmd))
588                 goto out;
589         /*
590          * The mmap_lock held all the way back in m_start() is what
591          * keeps khugepaged out of here and from collapsing things
592          * in here.
593          */
594         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
595         for (; addr != end; pte++, addr += PAGE_SIZE)
596                 smaps_pte_entry(pte, addr, walk);
597         pte_unmap_unlock(pte - 1, ptl);
598 out:
599         cond_resched();
600         return 0;
601 }
602
603 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
604 {
605         /*
606          * Don't forget to update Documentation/ on changes.
607          */
608         static const char mnemonics[BITS_PER_LONG][2] = {
609                 /*
610                  * In case if we meet a flag we don't know about.
611                  */
612                 [0 ... (BITS_PER_LONG-1)] = "??",
613
614                 [ilog2(VM_READ)]        = "rd",
615                 [ilog2(VM_WRITE)]       = "wr",
616                 [ilog2(VM_EXEC)]        = "ex",
617                 [ilog2(VM_SHARED)]      = "sh",
618                 [ilog2(VM_MAYREAD)]     = "mr",
619                 [ilog2(VM_MAYWRITE)]    = "mw",
620                 [ilog2(VM_MAYEXEC)]     = "me",
621                 [ilog2(VM_MAYSHARE)]    = "ms",
622                 [ilog2(VM_GROWSDOWN)]   = "gd",
623                 [ilog2(VM_PFNMAP)]      = "pf",
624                 [ilog2(VM_DENYWRITE)]   = "dw",
625                 [ilog2(VM_LOCKED)]      = "lo",
626                 [ilog2(VM_IO)]          = "io",
627                 [ilog2(VM_SEQ_READ)]    = "sr",
628                 [ilog2(VM_RAND_READ)]   = "rr",
629                 [ilog2(VM_DONTCOPY)]    = "dc",
630                 [ilog2(VM_DONTEXPAND)]  = "de",
631                 [ilog2(VM_ACCOUNT)]     = "ac",
632                 [ilog2(VM_NORESERVE)]   = "nr",
633                 [ilog2(VM_HUGETLB)]     = "ht",
634                 [ilog2(VM_SYNC)]        = "sf",
635                 [ilog2(VM_ARCH_1)]      = "ar",
636                 [ilog2(VM_WIPEONFORK)]  = "wf",
637                 [ilog2(VM_DONTDUMP)]    = "dd",
638 #ifdef CONFIG_ARM64_BTI
639                 [ilog2(VM_ARM64_BTI)]   = "bt",
640 #endif
641 #ifdef CONFIG_MEM_SOFT_DIRTY
642                 [ilog2(VM_SOFTDIRTY)]   = "sd",
643 #endif
644                 [ilog2(VM_MIXEDMAP)]    = "mm",
645                 [ilog2(VM_HUGEPAGE)]    = "hg",
646                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
647                 [ilog2(VM_MERGEABLE)]   = "mg",
648                 [ilog2(VM_UFFD_MISSING)]= "um",
649                 [ilog2(VM_UFFD_WP)]     = "uw",
650 #ifdef CONFIG_ARM64_MTE
651                 [ilog2(VM_MTE)]         = "mt",
652                 [ilog2(VM_MTE_ALLOWED)] = "",
653 #endif
654 #ifdef CONFIG_ARCH_HAS_PKEYS
655                 /* These come out via ProtectionKey: */
656                 [ilog2(VM_PKEY_BIT0)]   = "",
657                 [ilog2(VM_PKEY_BIT1)]   = "",
658                 [ilog2(VM_PKEY_BIT2)]   = "",
659                 [ilog2(VM_PKEY_BIT3)]   = "",
660 #if VM_PKEY_BIT4
661                 [ilog2(VM_PKEY_BIT4)]   = "",
662 #endif
663 #endif /* CONFIG_ARCH_HAS_PKEYS */
664         };
665         size_t i;
666
667         seq_puts(m, "VmFlags: ");
668         for (i = 0; i < BITS_PER_LONG; i++) {
669                 if (!mnemonics[i][0])
670                         continue;
671                 if (vma->vm_flags & (1UL << i)) {
672                         seq_putc(m, mnemonics[i][0]);
673                         seq_putc(m, mnemonics[i][1]);
674                         seq_putc(m, ' ');
675                 }
676         }
677         seq_putc(m, '\n');
678 }
679
680 #ifdef CONFIG_HUGETLB_PAGE
681 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
682                                  unsigned long addr, unsigned long end,
683                                  struct mm_walk *walk)
684 {
685         struct mem_size_stats *mss = walk->private;
686         struct vm_area_struct *vma = walk->vma;
687         struct page *page = NULL;
688
689         if (pte_present(*pte)) {
690                 page = vm_normal_page(vma, addr, *pte);
691         } else if (is_swap_pte(*pte)) {
692                 swp_entry_t swpent = pte_to_swp_entry(*pte);
693
694                 if (is_migration_entry(swpent))
695                         page = migration_entry_to_page(swpent);
696                 else if (is_device_private_entry(swpent))
697                         page = device_private_entry_to_page(swpent);
698         }
699         if (page) {
700                 int mapcount = page_mapcount(page);
701
702                 if (mapcount >= 2)
703                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
704                 else
705                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
706         }
707         return 0;
708 }
709 #else
710 #define smaps_hugetlb_range     NULL
711 #endif /* HUGETLB_PAGE */
712
713 static const struct mm_walk_ops smaps_walk_ops = {
714         .pmd_entry              = smaps_pte_range,
715         .hugetlb_entry          = smaps_hugetlb_range,
716 };
717
718 static const struct mm_walk_ops smaps_shmem_walk_ops = {
719         .pmd_entry              = smaps_pte_range,
720         .hugetlb_entry          = smaps_hugetlb_range,
721         .pte_hole               = smaps_pte_hole,
722 };
723
724 /*
725  * Gather mem stats from @vma with the indicated beginning
726  * address @start, and keep them in @mss.
727  *
728  * Use vm_start of @vma as the beginning address if @start is 0.
729  */
730 static void smap_gather_stats(struct vm_area_struct *vma,
731                 struct mem_size_stats *mss, unsigned long start)
732 {
733         const struct mm_walk_ops *ops = &smaps_walk_ops;
734
735         /* Invalid start */
736         if (start >= vma->vm_end)
737                 return;
738
739 #ifdef CONFIG_SHMEM
740         /* In case of smaps_rollup, reset the value from previous vma */
741         mss->check_shmem_swap = false;
742         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
743                 /*
744                  * For shared or readonly shmem mappings we know that all
745                  * swapped out pages belong to the shmem object, and we can
746                  * obtain the swap value much more efficiently. For private
747                  * writable mappings, we might have COW pages that are
748                  * not affected by the parent swapped out pages of the shmem
749                  * object, so we have to distinguish them during the page walk.
750                  * Unless we know that the shmem object (or the part mapped by
751                  * our VMA) has no swapped out pages at all.
752                  */
753                 unsigned long shmem_swapped = shmem_swap_usage(vma);
754
755                 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
756                                         !(vma->vm_flags & VM_WRITE))) {
757                         mss->swap += shmem_swapped;
758                 } else {
759                         mss->check_shmem_swap = true;
760                         ops = &smaps_shmem_walk_ops;
761                 }
762         }
763 #endif
764         /* mmap_lock is held in m_start */
765         if (!start)
766                 walk_page_vma(vma, ops, mss);
767         else
768                 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
769 }
770
771 #define SEQ_PUT_DEC(str, val) \
772                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
773
774 /* Show the contents common for smaps and smaps_rollup */
775 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
776         bool rollup_mode)
777 {
778         SEQ_PUT_DEC("Rss:            ", mss->resident);
779         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
780         if (rollup_mode) {
781                 /*
782                  * These are meaningful only for smaps_rollup, otherwise two of
783                  * them are zero, and the other one is the same as Pss.
784                  */
785                 SEQ_PUT_DEC(" kB\nPss_Anon:       ",
786                         mss->pss_anon >> PSS_SHIFT);
787                 SEQ_PUT_DEC(" kB\nPss_File:       ",
788                         mss->pss_file >> PSS_SHIFT);
789                 SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
790                         mss->pss_shmem >> PSS_SHIFT);
791         }
792         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
793         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
794         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
795         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
796         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
797         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
798         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
799         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
800         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
801         SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
802         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
803         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
804                                   mss->private_hugetlb >> 10, 7);
805         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
806         SEQ_PUT_DEC(" kB\nSwapPss:        ",
807                                         mss->swap_pss >> PSS_SHIFT);
808         SEQ_PUT_DEC(" kB\nLocked:         ",
809                                         mss->pss_locked >> PSS_SHIFT);
810         seq_puts(m, " kB\n");
811 }
812
813 static int show_smap(struct seq_file *m, void *v)
814 {
815         struct vm_area_struct *vma = v;
816         struct mem_size_stats mss;
817
818         memset(&mss, 0, sizeof(mss));
819
820         smap_gather_stats(vma, &mss, 0);
821
822         show_map_vma(m, vma);
823
824         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
825         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
826         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
827         seq_puts(m, " kB\n");
828
829         __show_smap(m, &mss, false);
830
831         seq_printf(m, "THPeligible:    %d\n",
832                    transparent_hugepage_enabled(vma));
833
834         if (arch_pkeys_enabled())
835                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
836         show_smap_vma_flags(m, vma);
837
838         return 0;
839 }
840
841 static int show_smaps_rollup(struct seq_file *m, void *v)
842 {
843         struct proc_maps_private *priv = m->private;
844         struct mem_size_stats mss;
845         struct mm_struct *mm;
846         struct vm_area_struct *vma;
847         unsigned long last_vma_end = 0;
848         int ret = 0;
849
850         priv->task = get_proc_task(priv->inode);
851         if (!priv->task)
852                 return -ESRCH;
853
854         mm = priv->mm;
855         if (!mm || !mmget_not_zero(mm)) {
856                 ret = -ESRCH;
857                 goto out_put_task;
858         }
859
860         memset(&mss, 0, sizeof(mss));
861
862         ret = mmap_read_lock_killable(mm);
863         if (ret)
864                 goto out_put_mm;
865
866         hold_task_mempolicy(priv);
867
868         for (vma = priv->mm->mmap; vma;) {
869                 smap_gather_stats(vma, &mss, 0);
870                 last_vma_end = vma->vm_end;
871
872                 /*
873                  * Release mmap_lock temporarily if someone wants to
874                  * access it for write request.
875                  */
876                 if (mmap_lock_is_contended(mm)) {
877                         mmap_read_unlock(mm);
878                         ret = mmap_read_lock_killable(mm);
879                         if (ret) {
880                                 release_task_mempolicy(priv);
881                                 goto out_put_mm;
882                         }
883
884                         /*
885                          * After dropping the lock, there are four cases to
886                          * consider. See the following example for explanation.
887                          *
888                          *   +------+------+-----------+
889                          *   | VMA1 | VMA2 | VMA3      |
890                          *   +------+------+-----------+
891                          *   |      |      |           |
892                          *  4k     8k     16k         400k
893                          *
894                          * Suppose we drop the lock after reading VMA2 due to
895                          * contention, then we get:
896                          *
897                          *      last_vma_end = 16k
898                          *
899                          * 1) VMA2 is freed, but VMA3 exists:
900                          *
901                          *    find_vma(mm, 16k - 1) will return VMA3.
902                          *    In this case, just continue from VMA3.
903                          *
904                          * 2) VMA2 still exists:
905                          *
906                          *    find_vma(mm, 16k - 1) will return VMA2.
907                          *    Iterate the loop like the original one.
908                          *
909                          * 3) No more VMAs can be found:
910                          *
911                          *    find_vma(mm, 16k - 1) will return NULL.
912                          *    No more things to do, just break.
913                          *
914                          * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
915                          *
916                          *    find_vma(mm, 16k - 1) will return VMA' whose range
917                          *    contains last_vma_end.
918                          *    Iterate VMA' from last_vma_end.
919                          */
920                         vma = find_vma(mm, last_vma_end - 1);
921                         /* Case 3 above */
922                         if (!vma)
923                                 break;
924
925                         /* Case 1 above */
926                         if (vma->vm_start >= last_vma_end)
927                                 continue;
928
929                         /* Case 4 above */
930                         if (vma->vm_end > last_vma_end)
931                                 smap_gather_stats(vma, &mss, last_vma_end);
932                 }
933                 /* Case 2 above */
934                 vma = vma->vm_next;
935         }
936
937         show_vma_header_prefix(m, priv->mm->mmap->vm_start,
938                                last_vma_end, 0, 0, 0, 0);
939         seq_pad(m, ' ');
940         seq_puts(m, "[rollup]\n");
941
942         __show_smap(m, &mss, true);
943
944         release_task_mempolicy(priv);
945         mmap_read_unlock(mm);
946
947 out_put_mm:
948         mmput(mm);
949 out_put_task:
950         put_task_struct(priv->task);
951         priv->task = NULL;
952
953         return ret;
954 }
955 #undef SEQ_PUT_DEC
956
957 static const struct seq_operations proc_pid_smaps_op = {
958         .start  = m_start,
959         .next   = m_next,
960         .stop   = m_stop,
961         .show   = show_smap
962 };
963
964 static int pid_smaps_open(struct inode *inode, struct file *file)
965 {
966         return do_maps_open(inode, file, &proc_pid_smaps_op);
967 }
968
969 static int smaps_rollup_open(struct inode *inode, struct file *file)
970 {
971         int ret;
972         struct proc_maps_private *priv;
973
974         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
975         if (!priv)
976                 return -ENOMEM;
977
978         ret = single_open(file, show_smaps_rollup, priv);
979         if (ret)
980                 goto out_free;
981
982         priv->inode = inode;
983         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
984         if (IS_ERR(priv->mm)) {
985                 ret = PTR_ERR(priv->mm);
986
987                 single_release(inode, file);
988                 goto out_free;
989         }
990
991         return 0;
992
993 out_free:
994         kfree(priv);
995         return ret;
996 }
997
998 static int smaps_rollup_release(struct inode *inode, struct file *file)
999 {
1000         struct seq_file *seq = file->private_data;
1001         struct proc_maps_private *priv = seq->private;
1002
1003         if (priv->mm)
1004                 mmdrop(priv->mm);
1005
1006         kfree(priv);
1007         return single_release(inode, file);
1008 }
1009
1010 const struct file_operations proc_pid_smaps_operations = {
1011         .open           = pid_smaps_open,
1012         .read           = seq_read,
1013         .llseek         = seq_lseek,
1014         .release        = proc_map_release,
1015 };
1016
1017 const struct file_operations proc_pid_smaps_rollup_operations = {
1018         .open           = smaps_rollup_open,
1019         .read           = seq_read,
1020         .llseek         = seq_lseek,
1021         .release        = smaps_rollup_release,
1022 };
1023
1024 enum clear_refs_types {
1025         CLEAR_REFS_ALL = 1,
1026         CLEAR_REFS_ANON,
1027         CLEAR_REFS_MAPPED,
1028         CLEAR_REFS_SOFT_DIRTY,
1029         CLEAR_REFS_MM_HIWATER_RSS,
1030         CLEAR_REFS_LAST,
1031 };
1032
1033 struct clear_refs_private {
1034         enum clear_refs_types type;
1035 };
1036
1037 #ifdef CONFIG_MEM_SOFT_DIRTY
1038 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1039                 unsigned long addr, pte_t *pte)
1040 {
1041         /*
1042          * The soft-dirty tracker uses #PF-s to catch writes
1043          * to pages, so write-protect the pte as well. See the
1044          * Documentation/admin-guide/mm/soft-dirty.rst for full description
1045          * of how soft-dirty works.
1046          */
1047         pte_t ptent = *pte;
1048
1049         if (pte_present(ptent)) {
1050                 pte_t old_pte;
1051
1052                 old_pte = ptep_modify_prot_start(vma, addr, pte);
1053                 ptent = pte_wrprotect(old_pte);
1054                 ptent = pte_clear_soft_dirty(ptent);
1055                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1056         } else if (is_swap_pte(ptent)) {
1057                 ptent = pte_swp_clear_soft_dirty(ptent);
1058                 set_pte_at(vma->vm_mm, addr, pte, ptent);
1059         }
1060 }
1061 #else
1062 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1063                 unsigned long addr, pte_t *pte)
1064 {
1065 }
1066 #endif
1067
1068 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1069 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1070                 unsigned long addr, pmd_t *pmdp)
1071 {
1072         pmd_t old, pmd = *pmdp;
1073
1074         if (pmd_present(pmd)) {
1075                 /* See comment in change_huge_pmd() */
1076                 old = pmdp_invalidate(vma, addr, pmdp);
1077                 if (pmd_dirty(old))
1078                         pmd = pmd_mkdirty(pmd);
1079                 if (pmd_young(old))
1080                         pmd = pmd_mkyoung(pmd);
1081
1082                 pmd = pmd_wrprotect(pmd);
1083                 pmd = pmd_clear_soft_dirty(pmd);
1084
1085                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1086         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1087                 pmd = pmd_swp_clear_soft_dirty(pmd);
1088                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1089         }
1090 }
1091 #else
1092 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1093                 unsigned long addr, pmd_t *pmdp)
1094 {
1095 }
1096 #endif
1097
1098 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1099                                 unsigned long end, struct mm_walk *walk)
1100 {
1101         struct clear_refs_private *cp = walk->private;
1102         struct vm_area_struct *vma = walk->vma;
1103         pte_t *pte, ptent;
1104         spinlock_t *ptl;
1105         struct page *page;
1106
1107         ptl = pmd_trans_huge_lock(pmd, vma);
1108         if (ptl) {
1109                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1110                         clear_soft_dirty_pmd(vma, addr, pmd);
1111                         goto out;
1112                 }
1113
1114                 if (!pmd_present(*pmd))
1115                         goto out;
1116
1117                 page = pmd_page(*pmd);
1118
1119                 /* Clear accessed and referenced bits. */
1120                 pmdp_test_and_clear_young(vma, addr, pmd);
1121                 test_and_clear_page_young(page);
1122                 ClearPageReferenced(page);
1123 out:
1124                 spin_unlock(ptl);
1125                 return 0;
1126         }
1127
1128         if (pmd_trans_unstable(pmd))
1129                 return 0;
1130
1131         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1132         for (; addr != end; pte++, addr += PAGE_SIZE) {
1133                 ptent = *pte;
1134
1135                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1136                         clear_soft_dirty(vma, addr, pte);
1137                         continue;
1138                 }
1139
1140                 if (!pte_present(ptent))
1141                         continue;
1142
1143                 page = vm_normal_page(vma, addr, ptent);
1144                 if (!page)
1145                         continue;
1146
1147                 /* Clear accessed and referenced bits. */
1148                 ptep_test_and_clear_young(vma, addr, pte);
1149                 test_and_clear_page_young(page);
1150                 ClearPageReferenced(page);
1151         }
1152         pte_unmap_unlock(pte - 1, ptl);
1153         cond_resched();
1154         return 0;
1155 }
1156
1157 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1158                                 struct mm_walk *walk)
1159 {
1160         struct clear_refs_private *cp = walk->private;
1161         struct vm_area_struct *vma = walk->vma;
1162
1163         if (vma->vm_flags & VM_PFNMAP)
1164                 return 1;
1165
1166         /*
1167          * Writing 1 to /proc/pid/clear_refs affects all pages.
1168          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1169          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1170          * Writing 4 to /proc/pid/clear_refs affects all pages.
1171          */
1172         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1173                 return 1;
1174         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1175                 return 1;
1176         return 0;
1177 }
1178
1179 static const struct mm_walk_ops clear_refs_walk_ops = {
1180         .pmd_entry              = clear_refs_pte_range,
1181         .test_walk              = clear_refs_test_walk,
1182 };
1183
1184 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1185                                 size_t count, loff_t *ppos)
1186 {
1187         struct task_struct *task;
1188         char buffer[PROC_NUMBUF];
1189         struct mm_struct *mm;
1190         struct vm_area_struct *vma;
1191         enum clear_refs_types type;
1192         struct mmu_gather tlb;
1193         int itype;
1194         int rv;
1195
1196         memset(buffer, 0, sizeof(buffer));
1197         if (count > sizeof(buffer) - 1)
1198                 count = sizeof(buffer) - 1;
1199         if (copy_from_user(buffer, buf, count))
1200                 return -EFAULT;
1201         rv = kstrtoint(strstrip(buffer), 10, &itype);
1202         if (rv < 0)
1203                 return rv;
1204         type = (enum clear_refs_types)itype;
1205         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1206                 return -EINVAL;
1207
1208         task = get_proc_task(file_inode(file));
1209         if (!task)
1210                 return -ESRCH;
1211         mm = get_task_mm(task);
1212         if (mm) {
1213                 struct mmu_notifier_range range;
1214                 struct clear_refs_private cp = {
1215                         .type = type,
1216                 };
1217
1218                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1219                         if (mmap_write_lock_killable(mm)) {
1220                                 count = -EINTR;
1221                                 goto out_mm;
1222                         }
1223
1224                         /*
1225                          * Writing 5 to /proc/pid/clear_refs resets the peak
1226                          * resident set size to this mm's current rss value.
1227                          */
1228                         reset_mm_hiwater_rss(mm);
1229                         mmap_write_unlock(mm);
1230                         goto out_mm;
1231                 }
1232
1233                 if (mmap_read_lock_killable(mm)) {
1234                         count = -EINTR;
1235                         goto out_mm;
1236                 }
1237                 tlb_gather_mmu(&tlb, mm, 0, -1);
1238                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1239                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1240                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1241                                         continue;
1242                                 mmap_read_unlock(mm);
1243                                 if (mmap_write_lock_killable(mm)) {
1244                                         count = -EINTR;
1245                                         goto out_mm;
1246                                 }
1247                                 /*
1248                                  * Avoid to modify vma->vm_flags
1249                                  * without locked ops while the
1250                                  * coredump reads the vm_flags.
1251                                  */
1252                                 if (!mmget_still_valid(mm)) {
1253                                         /*
1254                                          * Silently return "count"
1255                                          * like if get_task_mm()
1256                                          * failed. FIXME: should this
1257                                          * function have returned
1258                                          * -ESRCH if get_task_mm()
1259                                          * failed like if
1260                                          * get_proc_task() fails?
1261                                          */
1262                                         mmap_write_unlock(mm);
1263                                         goto out_mm;
1264                                 }
1265                                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1266                                         vma->vm_flags &= ~VM_SOFTDIRTY;
1267                                         vma_set_page_prot(vma);
1268                                 }
1269                                 mmap_write_downgrade(mm);
1270                                 break;
1271                         }
1272
1273                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1274                                                 0, NULL, mm, 0, -1UL);
1275                         mmu_notifier_invalidate_range_start(&range);
1276                 }
1277                 walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
1278                                 &cp);
1279                 if (type == CLEAR_REFS_SOFT_DIRTY)
1280                         mmu_notifier_invalidate_range_end(&range);
1281                 tlb_finish_mmu(&tlb, 0, -1);
1282                 mmap_read_unlock(mm);
1283 out_mm:
1284                 mmput(mm);
1285         }
1286         put_task_struct(task);
1287
1288         return count;
1289 }
1290
1291 const struct file_operations proc_clear_refs_operations = {
1292         .write          = clear_refs_write,
1293         .llseek         = noop_llseek,
1294 };
1295
1296 typedef struct {
1297         u64 pme;
1298 } pagemap_entry_t;
1299
1300 struct pagemapread {
1301         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1302         pagemap_entry_t *buffer;
1303         bool show_pfn;
1304 };
1305
1306 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1307 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1308
1309 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1310 #define PM_PFRAME_BITS          55
1311 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1312 #define PM_SOFT_DIRTY           BIT_ULL(55)
1313 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1314 #define PM_FILE                 BIT_ULL(61)
1315 #define PM_SWAP                 BIT_ULL(62)
1316 #define PM_PRESENT              BIT_ULL(63)
1317
1318 #define PM_END_OF_BUFFER    1
1319
1320 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1321 {
1322         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1323 }
1324
1325 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1326                           struct pagemapread *pm)
1327 {
1328         pm->buffer[pm->pos++] = *pme;
1329         if (pm->pos >= pm->len)
1330                 return PM_END_OF_BUFFER;
1331         return 0;
1332 }
1333
1334 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1335                             __always_unused int depth, struct mm_walk *walk)
1336 {
1337         struct pagemapread *pm = walk->private;
1338         unsigned long addr = start;
1339         int err = 0;
1340
1341         while (addr < end) {
1342                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1343                 pagemap_entry_t pme = make_pme(0, 0);
1344                 /* End of address space hole, which we mark as non-present. */
1345                 unsigned long hole_end;
1346
1347                 if (vma)
1348                         hole_end = min(end, vma->vm_start);
1349                 else
1350                         hole_end = end;
1351
1352                 for (; addr < hole_end; addr += PAGE_SIZE) {
1353                         err = add_to_pagemap(addr, &pme, pm);
1354                         if (err)
1355                                 goto out;
1356                 }
1357
1358                 if (!vma)
1359                         break;
1360
1361                 /* Addresses in the VMA. */
1362                 if (vma->vm_flags & VM_SOFTDIRTY)
1363                         pme = make_pme(0, PM_SOFT_DIRTY);
1364                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1365                         err = add_to_pagemap(addr, &pme, pm);
1366                         if (err)
1367                                 goto out;
1368                 }
1369         }
1370 out:
1371         return err;
1372 }
1373
1374 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1375                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1376 {
1377         u64 frame = 0, flags = 0;
1378         struct page *page = NULL;
1379
1380         if (pte_present(pte)) {
1381                 if (pm->show_pfn)
1382                         frame = pte_pfn(pte);
1383                 flags |= PM_PRESENT;
1384                 page = vm_normal_page(vma, addr, pte);
1385                 if (pte_soft_dirty(pte))
1386                         flags |= PM_SOFT_DIRTY;
1387         } else if (is_swap_pte(pte)) {
1388                 swp_entry_t entry;
1389                 if (pte_swp_soft_dirty(pte))
1390                         flags |= PM_SOFT_DIRTY;
1391                 entry = pte_to_swp_entry(pte);
1392                 if (pm->show_pfn)
1393                         frame = swp_type(entry) |
1394                                 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1395                 flags |= PM_SWAP;
1396                 if (is_migration_entry(entry))
1397                         page = migration_entry_to_page(entry);
1398
1399                 if (is_device_private_entry(entry))
1400                         page = device_private_entry_to_page(entry);
1401         }
1402
1403         if (page && !PageAnon(page))
1404                 flags |= PM_FILE;
1405         if (page && page_mapcount(page) == 1)
1406                 flags |= PM_MMAP_EXCLUSIVE;
1407         if (vma->vm_flags & VM_SOFTDIRTY)
1408                 flags |= PM_SOFT_DIRTY;
1409
1410         return make_pme(frame, flags);
1411 }
1412
1413 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1414                              struct mm_walk *walk)
1415 {
1416         struct vm_area_struct *vma = walk->vma;
1417         struct pagemapread *pm = walk->private;
1418         spinlock_t *ptl;
1419         pte_t *pte, *orig_pte;
1420         int err = 0;
1421
1422 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1423         ptl = pmd_trans_huge_lock(pmdp, vma);
1424         if (ptl) {
1425                 u64 flags = 0, frame = 0;
1426                 pmd_t pmd = *pmdp;
1427                 struct page *page = NULL;
1428
1429                 if (vma->vm_flags & VM_SOFTDIRTY)
1430                         flags |= PM_SOFT_DIRTY;
1431
1432                 if (pmd_present(pmd)) {
1433                         page = pmd_page(pmd);
1434
1435                         flags |= PM_PRESENT;
1436                         if (pmd_soft_dirty(pmd))
1437                                 flags |= PM_SOFT_DIRTY;
1438                         if (pm->show_pfn)
1439                                 frame = pmd_pfn(pmd) +
1440                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1441                 }
1442 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1443                 else if (is_swap_pmd(pmd)) {
1444                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1445                         unsigned long offset;
1446
1447                         if (pm->show_pfn) {
1448                                 offset = swp_offset(entry) +
1449                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1450                                 frame = swp_type(entry) |
1451                                         (offset << MAX_SWAPFILES_SHIFT);
1452                         }
1453                         flags |= PM_SWAP;
1454                         if (pmd_swp_soft_dirty(pmd))
1455                                 flags |= PM_SOFT_DIRTY;
1456                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1457                         page = migration_entry_to_page(entry);
1458                 }
1459 #endif
1460
1461                 if (page && page_mapcount(page) == 1)
1462                         flags |= PM_MMAP_EXCLUSIVE;
1463
1464                 for (; addr != end; addr += PAGE_SIZE) {
1465                         pagemap_entry_t pme = make_pme(frame, flags);
1466
1467                         err = add_to_pagemap(addr, &pme, pm);
1468                         if (err)
1469                                 break;
1470                         if (pm->show_pfn) {
1471                                 if (flags & PM_PRESENT)
1472                                         frame++;
1473                                 else if (flags & PM_SWAP)
1474                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1475                         }
1476                 }
1477                 spin_unlock(ptl);
1478                 return err;
1479         }
1480
1481         if (pmd_trans_unstable(pmdp))
1482                 return 0;
1483 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1484
1485         /*
1486          * We can assume that @vma always points to a valid one and @end never
1487          * goes beyond vma->vm_end.
1488          */
1489         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1490         for (; addr < end; pte++, addr += PAGE_SIZE) {
1491                 pagemap_entry_t pme;
1492
1493                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1494                 err = add_to_pagemap(addr, &pme, pm);
1495                 if (err)
1496                         break;
1497         }
1498         pte_unmap_unlock(orig_pte, ptl);
1499
1500         cond_resched();
1501
1502         return err;
1503 }
1504
1505 #ifdef CONFIG_HUGETLB_PAGE
1506 /* This function walks within one hugetlb entry in the single call */
1507 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1508                                  unsigned long addr, unsigned long end,
1509                                  struct mm_walk *walk)
1510 {
1511         struct pagemapread *pm = walk->private;
1512         struct vm_area_struct *vma = walk->vma;
1513         u64 flags = 0, frame = 0;
1514         int err = 0;
1515         pte_t pte;
1516
1517         if (vma->vm_flags & VM_SOFTDIRTY)
1518                 flags |= PM_SOFT_DIRTY;
1519
1520         pte = huge_ptep_get(ptep);
1521         if (pte_present(pte)) {
1522                 struct page *page = pte_page(pte);
1523
1524                 if (!PageAnon(page))
1525                         flags |= PM_FILE;
1526
1527                 if (page_mapcount(page) == 1)
1528                         flags |= PM_MMAP_EXCLUSIVE;
1529
1530                 flags |= PM_PRESENT;
1531                 if (pm->show_pfn)
1532                         frame = pte_pfn(pte) +
1533                                 ((addr & ~hmask) >> PAGE_SHIFT);
1534         }
1535
1536         for (; addr != end; addr += PAGE_SIZE) {
1537                 pagemap_entry_t pme = make_pme(frame, flags);
1538
1539                 err = add_to_pagemap(addr, &pme, pm);
1540                 if (err)
1541                         return err;
1542                 if (pm->show_pfn && (flags & PM_PRESENT))
1543                         frame++;
1544         }
1545
1546         cond_resched();
1547
1548         return err;
1549 }
1550 #else
1551 #define pagemap_hugetlb_range   NULL
1552 #endif /* HUGETLB_PAGE */
1553
1554 static const struct mm_walk_ops pagemap_ops = {
1555         .pmd_entry      = pagemap_pmd_range,
1556         .pte_hole       = pagemap_pte_hole,
1557         .hugetlb_entry  = pagemap_hugetlb_range,
1558 };
1559
1560 /*
1561  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1562  *
1563  * For each page in the address space, this file contains one 64-bit entry
1564  * consisting of the following:
1565  *
1566  * Bits 0-54  page frame number (PFN) if present
1567  * Bits 0-4   swap type if swapped
1568  * Bits 5-54  swap offset if swapped
1569  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1570  * Bit  56    page exclusively mapped
1571  * Bits 57-60 zero
1572  * Bit  61    page is file-page or shared-anon
1573  * Bit  62    page swapped
1574  * Bit  63    page present
1575  *
1576  * If the page is not present but in swap, then the PFN contains an
1577  * encoding of the swap file number and the page's offset into the
1578  * swap. Unmapped pages return a null PFN. This allows determining
1579  * precisely which pages are mapped (or in swap) and comparing mapped
1580  * pages between processes.
1581  *
1582  * Efficient users of this interface will use /proc/pid/maps to
1583  * determine which areas of memory are actually mapped and llseek to
1584  * skip over unmapped regions.
1585  */
1586 static ssize_t pagemap_read(struct file *file, char __user *buf,
1587                             size_t count, loff_t *ppos)
1588 {
1589         struct mm_struct *mm = file->private_data;
1590         struct pagemapread pm;
1591         unsigned long src;
1592         unsigned long svpfn;
1593         unsigned long start_vaddr;
1594         unsigned long end_vaddr;
1595         int ret = 0, copied = 0;
1596
1597         if (!mm || !mmget_not_zero(mm))
1598                 goto out;
1599
1600         ret = -EINVAL;
1601         /* file position must be aligned */
1602         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1603                 goto out_mm;
1604
1605         ret = 0;
1606         if (!count)
1607                 goto out_mm;
1608
1609         /* do not disclose physical addresses: attack vector */
1610         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1611
1612         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1613         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1614         ret = -ENOMEM;
1615         if (!pm.buffer)
1616                 goto out_mm;
1617
1618         src = *ppos;
1619         svpfn = src / PM_ENTRY_BYTES;
1620         start_vaddr = svpfn << PAGE_SHIFT;
1621         end_vaddr = mm->task_size;
1622
1623         /* watch out for wraparound */
1624         if (svpfn > mm->task_size >> PAGE_SHIFT)
1625                 start_vaddr = end_vaddr;
1626
1627         /*
1628          * The odds are that this will stop walking way
1629          * before end_vaddr, because the length of the
1630          * user buffer is tracked in "pm", and the walk
1631          * will stop when we hit the end of the buffer.
1632          */
1633         ret = 0;
1634         while (count && (start_vaddr < end_vaddr)) {
1635                 int len;
1636                 unsigned long end;
1637
1638                 pm.pos = 0;
1639                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1640                 /* overflow ? */
1641                 if (end < start_vaddr || end > end_vaddr)
1642                         end = end_vaddr;
1643                 ret = mmap_read_lock_killable(mm);
1644                 if (ret)
1645                         goto out_free;
1646                 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1647                 mmap_read_unlock(mm);
1648                 start_vaddr = end;
1649
1650                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1651                 if (copy_to_user(buf, pm.buffer, len)) {
1652                         ret = -EFAULT;
1653                         goto out_free;
1654                 }
1655                 copied += len;
1656                 buf += len;
1657                 count -= len;
1658         }
1659         *ppos += copied;
1660         if (!ret || ret == PM_END_OF_BUFFER)
1661                 ret = copied;
1662
1663 out_free:
1664         kfree(pm.buffer);
1665 out_mm:
1666         mmput(mm);
1667 out:
1668         return ret;
1669 }
1670
1671 static int pagemap_open(struct inode *inode, struct file *file)
1672 {
1673         struct mm_struct *mm;
1674
1675         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1676         if (IS_ERR(mm))
1677                 return PTR_ERR(mm);
1678         file->private_data = mm;
1679         return 0;
1680 }
1681
1682 static int pagemap_release(struct inode *inode, struct file *file)
1683 {
1684         struct mm_struct *mm = file->private_data;
1685
1686         if (mm)
1687                 mmdrop(mm);
1688         return 0;
1689 }
1690
1691 const struct file_operations proc_pagemap_operations = {
1692         .llseek         = mem_lseek, /* borrow this */
1693         .read           = pagemap_read,
1694         .open           = pagemap_open,
1695         .release        = pagemap_release,
1696 };
1697 #endif /* CONFIG_PROC_PAGE_MONITOR */
1698
1699 #ifdef CONFIG_NUMA
1700
1701 struct numa_maps {
1702         unsigned long pages;
1703         unsigned long anon;
1704         unsigned long active;
1705         unsigned long writeback;
1706         unsigned long mapcount_max;
1707         unsigned long dirty;
1708         unsigned long swapcache;
1709         unsigned long node[MAX_NUMNODES];
1710 };
1711
1712 struct numa_maps_private {
1713         struct proc_maps_private proc_maps;
1714         struct numa_maps md;
1715 };
1716
1717 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1718                         unsigned long nr_pages)
1719 {
1720         int count = page_mapcount(page);
1721
1722         md->pages += nr_pages;
1723         if (pte_dirty || PageDirty(page))
1724                 md->dirty += nr_pages;
1725
1726         if (PageSwapCache(page))
1727                 md->swapcache += nr_pages;
1728
1729         if (PageActive(page) || PageUnevictable(page))
1730                 md->active += nr_pages;
1731
1732         if (PageWriteback(page))
1733                 md->writeback += nr_pages;
1734
1735         if (PageAnon(page))
1736                 md->anon += nr_pages;
1737
1738         if (count > md->mapcount_max)
1739                 md->mapcount_max = count;
1740
1741         md->node[page_to_nid(page)] += nr_pages;
1742 }
1743
1744 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1745                 unsigned long addr)
1746 {
1747         struct page *page;
1748         int nid;
1749
1750         if (!pte_present(pte))
1751                 return NULL;
1752
1753         page = vm_normal_page(vma, addr, pte);
1754         if (!page)
1755                 return NULL;
1756
1757         if (PageReserved(page))
1758                 return NULL;
1759
1760         nid = page_to_nid(page);
1761         if (!node_isset(nid, node_states[N_MEMORY]))
1762                 return NULL;
1763
1764         return page;
1765 }
1766
1767 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1768 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1769                                               struct vm_area_struct *vma,
1770                                               unsigned long addr)
1771 {
1772         struct page *page;
1773         int nid;
1774
1775         if (!pmd_present(pmd))
1776                 return NULL;
1777
1778         page = vm_normal_page_pmd(vma, addr, pmd);
1779         if (!page)
1780                 return NULL;
1781
1782         if (PageReserved(page))
1783                 return NULL;
1784
1785         nid = page_to_nid(page);
1786         if (!node_isset(nid, node_states[N_MEMORY]))
1787                 return NULL;
1788
1789         return page;
1790 }
1791 #endif
1792
1793 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1794                 unsigned long end, struct mm_walk *walk)
1795 {
1796         struct numa_maps *md = walk->private;
1797         struct vm_area_struct *vma = walk->vma;
1798         spinlock_t *ptl;
1799         pte_t *orig_pte;
1800         pte_t *pte;
1801
1802 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1803         ptl = pmd_trans_huge_lock(pmd, vma);
1804         if (ptl) {
1805                 struct page *page;
1806
1807                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1808                 if (page)
1809                         gather_stats(page, md, pmd_dirty(*pmd),
1810                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1811                 spin_unlock(ptl);
1812                 return 0;
1813         }
1814
1815         if (pmd_trans_unstable(pmd))
1816                 return 0;
1817 #endif
1818         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1819         do {
1820                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1821                 if (!page)
1822                         continue;
1823                 gather_stats(page, md, pte_dirty(*pte), 1);
1824
1825         } while (pte++, addr += PAGE_SIZE, addr != end);
1826         pte_unmap_unlock(orig_pte, ptl);
1827         cond_resched();
1828         return 0;
1829 }
1830 #ifdef CONFIG_HUGETLB_PAGE
1831 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1832                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1833 {
1834         pte_t huge_pte = huge_ptep_get(pte);
1835         struct numa_maps *md;
1836         struct page *page;
1837
1838         if (!pte_present(huge_pte))
1839                 return 0;
1840
1841         page = pte_page(huge_pte);
1842         if (!page)
1843                 return 0;
1844
1845         md = walk->private;
1846         gather_stats(page, md, pte_dirty(huge_pte), 1);
1847         return 0;
1848 }
1849
1850 #else
1851 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1852                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1853 {
1854         return 0;
1855 }
1856 #endif
1857
1858 static const struct mm_walk_ops show_numa_ops = {
1859         .hugetlb_entry = gather_hugetlb_stats,
1860         .pmd_entry = gather_pte_stats,
1861 };
1862
1863 /*
1864  * Display pages allocated per node and memory policy via /proc.
1865  */
1866 static int show_numa_map(struct seq_file *m, void *v)
1867 {
1868         struct numa_maps_private *numa_priv = m->private;
1869         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1870         struct vm_area_struct *vma = v;
1871         struct numa_maps *md = &numa_priv->md;
1872         struct file *file = vma->vm_file;
1873         struct mm_struct *mm = vma->vm_mm;
1874         struct mempolicy *pol;
1875         char buffer[64];
1876         int nid;
1877
1878         if (!mm)
1879                 return 0;
1880
1881         /* Ensure we start with an empty set of numa_maps statistics. */
1882         memset(md, 0, sizeof(*md));
1883
1884         pol = __get_vma_policy(vma, vma->vm_start);
1885         if (pol) {
1886                 mpol_to_str(buffer, sizeof(buffer), pol);
1887                 mpol_cond_put(pol);
1888         } else {
1889                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1890         }
1891
1892         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1893
1894         if (file) {
1895                 seq_puts(m, " file=");
1896                 seq_file_path(m, file, "\n\t= ");
1897         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1898                 seq_puts(m, " heap");
1899         } else if (is_stack(vma)) {
1900                 seq_puts(m, " stack");
1901         }
1902
1903         if (is_vm_hugetlb_page(vma))
1904                 seq_puts(m, " huge");
1905
1906         /* mmap_lock is held by m_start */
1907         walk_page_vma(vma, &show_numa_ops, md);
1908
1909         if (!md->pages)
1910                 goto out;
1911
1912         if (md->anon)
1913                 seq_printf(m, " anon=%lu", md->anon);
1914
1915         if (md->dirty)
1916                 seq_printf(m, " dirty=%lu", md->dirty);
1917
1918         if (md->pages != md->anon && md->pages != md->dirty)
1919                 seq_printf(m, " mapped=%lu", md->pages);
1920
1921         if (md->mapcount_max > 1)
1922                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1923
1924         if (md->swapcache)
1925                 seq_printf(m, " swapcache=%lu", md->swapcache);
1926
1927         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1928                 seq_printf(m, " active=%lu", md->active);
1929
1930         if (md->writeback)
1931                 seq_printf(m, " writeback=%lu", md->writeback);
1932
1933         for_each_node_state(nid, N_MEMORY)
1934                 if (md->node[nid])
1935                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1936
1937         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1938 out:
1939         seq_putc(m, '\n');
1940         return 0;
1941 }
1942
1943 static const struct seq_operations proc_pid_numa_maps_op = {
1944         .start  = m_start,
1945         .next   = m_next,
1946         .stop   = m_stop,
1947         .show   = show_numa_map,
1948 };
1949
1950 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1951 {
1952         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1953                                 sizeof(struct numa_maps_private));
1954 }
1955
1956 const struct file_operations proc_pid_numa_maps_operations = {
1957         .open           = pid_numa_maps_open,
1958         .read           = seq_read,
1959         .llseek         = seq_lseek,
1960         .release        = proc_map_release,
1961 };
1962
1963 #endif /* CONFIG_NUMA */