GNU Linux-libre 5.4.257-gnu1
[releases.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 vma_stop(struct proc_maps_private *priv)
127 {
128         struct mm_struct *mm = priv->mm;
129
130         release_task_mempolicy(priv);
131         up_read(&mm->mmap_sem);
132         mmput(mm);
133 }
134
135 static struct vm_area_struct *
136 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
137 {
138         if (vma == priv->tail_vma)
139                 return NULL;
140         return vma->vm_next ?: priv->tail_vma;
141 }
142
143 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
144 {
145         if (m->count < m->size) /* vma is copied successfully */
146                 m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
147 }
148
149 static void *m_start(struct seq_file *m, loff_t *ppos)
150 {
151         struct proc_maps_private *priv = m->private;
152         unsigned long last_addr = m->version;
153         struct mm_struct *mm;
154         struct vm_area_struct *vma;
155         unsigned int pos = *ppos;
156
157         /* See m_cache_vma(). Zero at the start or after lseek. */
158         if (last_addr == -1UL)
159                 return NULL;
160
161         priv->task = get_proc_task(priv->inode);
162         if (!priv->task)
163                 return ERR_PTR(-ESRCH);
164
165         mm = priv->mm;
166         if (!mm || !mmget_not_zero(mm))
167                 return NULL;
168
169         if (down_read_killable(&mm->mmap_sem)) {
170                 mmput(mm);
171                 return ERR_PTR(-EINTR);
172         }
173
174         hold_task_mempolicy(priv);
175         priv->tail_vma = get_gate_vma(mm);
176
177         if (last_addr) {
178                 vma = find_vma(mm, last_addr - 1);
179                 if (vma && vma->vm_start <= last_addr)
180                         vma = m_next_vma(priv, vma);
181                 if (vma)
182                         return vma;
183         }
184
185         m->version = 0;
186         if (pos < mm->map_count) {
187                 for (vma = mm->mmap; pos; pos--) {
188                         m->version = vma->vm_start;
189                         vma = vma->vm_next;
190                 }
191                 return vma;
192         }
193
194         /* we do not bother to update m->version in this case */
195         if (pos == mm->map_count && priv->tail_vma)
196                 return priv->tail_vma;
197
198         vma_stop(priv);
199         return NULL;
200 }
201
202 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
203 {
204         struct proc_maps_private *priv = m->private;
205         struct vm_area_struct *next;
206
207         (*pos)++;
208         next = m_next_vma(priv, v);
209         if (!next)
210                 vma_stop(priv);
211         return next;
212 }
213
214 static void m_stop(struct seq_file *m, void *v)
215 {
216         struct proc_maps_private *priv = m->private;
217
218         if (!IS_ERR_OR_NULL(v))
219                 vma_stop(priv);
220         if (priv->task) {
221                 put_task_struct(priv->task);
222                 priv->task = NULL;
223         }
224 }
225
226 static int proc_maps_open(struct inode *inode, struct file *file,
227                         const struct seq_operations *ops, int psize)
228 {
229         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
230
231         if (!priv)
232                 return -ENOMEM;
233
234         priv->inode = inode;
235         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
236         if (IS_ERR(priv->mm)) {
237                 int err = PTR_ERR(priv->mm);
238
239                 seq_release_private(inode, file);
240                 return err;
241         }
242
243         return 0;
244 }
245
246 static int proc_map_release(struct inode *inode, struct file *file)
247 {
248         struct seq_file *seq = file->private_data;
249         struct proc_maps_private *priv = seq->private;
250
251         if (priv->mm)
252                 mmdrop(priv->mm);
253
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_put_hex_ll(m, NULL, start, 8);
286         seq_put_hex_ll(m, "-", end, 8);
287         seq_putc(m, ' ');
288         seq_putc(m, flags & VM_READ ? 'r' : '-');
289         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
290         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
291         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
292         seq_put_hex_ll(m, " ", pgoff, 8);
293         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
294         seq_put_hex_ll(m, ":", MINOR(dev), 2);
295         seq_put_decimal_ull(m, " ", ino);
296         seq_putc(m, ' ');
297 }
298
299 static void
300 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
301 {
302         struct mm_struct *mm = vma->vm_mm;
303         struct file *file = vma->vm_file;
304         vm_flags_t flags = vma->vm_flags;
305         unsigned long ino = 0;
306         unsigned long long pgoff = 0;
307         unsigned long start, end;
308         dev_t dev = 0;
309         const char *name = NULL;
310
311         if (file) {
312                 struct inode *inode = file_inode(vma->vm_file);
313                 dev = inode->i_sb->s_dev;
314                 ino = inode->i_ino;
315                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
316         }
317
318         start = vma->vm_start;
319         end = vma->vm_end;
320         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
321
322         /*
323          * Print the dentry name for named mappings, and a
324          * special [heap] marker for the heap:
325          */
326         if (file) {
327                 seq_pad(m, ' ');
328                 seq_file_path(m, file, "\n");
329                 goto done;
330         }
331
332         if (vma->vm_ops && vma->vm_ops->name) {
333                 name = vma->vm_ops->name(vma);
334                 if (name)
335                         goto done;
336         }
337
338         name = arch_vma_name(vma);
339         if (!name) {
340                 if (!mm) {
341                         name = "[vdso]";
342                         goto done;
343                 }
344
345                 if (vma->vm_start <= mm->brk &&
346                     vma->vm_end >= mm->start_brk) {
347                         name = "[heap]";
348                         goto done;
349                 }
350
351                 if (is_stack(vma))
352                         name = "[stack]";
353         }
354
355 done:
356         if (name) {
357                 seq_pad(m, ' ');
358                 seq_puts(m, name);
359         }
360         seq_putc(m, '\n');
361 }
362
363 static int show_map(struct seq_file *m, void *v)
364 {
365         show_map_vma(m, v);
366         m_cache_vma(m, v);
367         return 0;
368 }
369
370 static const struct seq_operations proc_pid_maps_op = {
371         .start  = m_start,
372         .next   = m_next,
373         .stop   = m_stop,
374         .show   = show_map
375 };
376
377 static int pid_maps_open(struct inode *inode, struct file *file)
378 {
379         return do_maps_open(inode, file, &proc_pid_maps_op);
380 }
381
382 const struct file_operations proc_pid_maps_operations = {
383         .open           = pid_maps_open,
384         .read           = seq_read,
385         .llseek         = seq_lseek,
386         .release        = proc_map_release,
387 };
388
389 /*
390  * Proportional Set Size(PSS): my share of RSS.
391  *
392  * PSS of a process is the count of pages it has in memory, where each
393  * page is divided by the number of processes sharing it.  So if a
394  * process has 1000 pages all to itself, and 1000 shared with one other
395  * process, its PSS will be 1500.
396  *
397  * To keep (accumulated) division errors low, we adopt a 64bit
398  * fixed-point pss counter to minimize division errors. So (pss >>
399  * PSS_SHIFT) would be the real byte count.
400  *
401  * A shift of 12 before division means (assuming 4K page size):
402  *      - 1M 3-user-pages add up to 8KB errors;
403  *      - supports mapcount up to 2^24, or 16M;
404  *      - supports PSS up to 2^52 bytes, or 4PB.
405  */
406 #define PSS_SHIFT 12
407
408 #ifdef CONFIG_PROC_PAGE_MONITOR
409 struct mem_size_stats {
410         unsigned long resident;
411         unsigned long shared_clean;
412         unsigned long shared_dirty;
413         unsigned long private_clean;
414         unsigned long private_dirty;
415         unsigned long referenced;
416         unsigned long anonymous;
417         unsigned long lazyfree;
418         unsigned long anonymous_thp;
419         unsigned long shmem_thp;
420         unsigned long file_thp;
421         unsigned long swap;
422         unsigned long shared_hugetlb;
423         unsigned long private_hugetlb;
424         u64 pss;
425         u64 pss_anon;
426         u64 pss_file;
427         u64 pss_shmem;
428         u64 pss_locked;
429         u64 swap_pss;
430         bool check_shmem_swap;
431 };
432
433 static void smaps_page_accumulate(struct mem_size_stats *mss,
434                 struct page *page, unsigned long size, unsigned long pss,
435                 bool dirty, bool locked, bool private)
436 {
437         mss->pss += pss;
438
439         if (PageAnon(page))
440                 mss->pss_anon += pss;
441         else if (PageSwapBacked(page))
442                 mss->pss_shmem += pss;
443         else
444                 mss->pss_file += pss;
445
446         if (locked)
447                 mss->pss_locked += pss;
448
449         if (dirty || PageDirty(page)) {
450                 if (private)
451                         mss->private_dirty += size;
452                 else
453                         mss->shared_dirty += size;
454         } else {
455                 if (private)
456                         mss->private_clean += size;
457                 else
458                         mss->shared_clean += size;
459         }
460 }
461
462 static void smaps_account(struct mem_size_stats *mss, struct page *page,
463                 bool compound, bool young, bool dirty, bool locked)
464 {
465         int i, nr = compound ? compound_nr(page) : 1;
466         unsigned long size = nr * PAGE_SIZE;
467
468         /*
469          * First accumulate quantities that depend only on |size| and the type
470          * of the compound page.
471          */
472         if (PageAnon(page)) {
473                 mss->anonymous += size;
474                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
475                         mss->lazyfree += size;
476         }
477
478         mss->resident += size;
479         /* Accumulate the size in pages that have been accessed. */
480         if (young || page_is_young(page) || PageReferenced(page))
481                 mss->referenced += size;
482
483         /*
484          * Then accumulate quantities that may depend on sharing, or that may
485          * differ page-by-page.
486          *
487          * page_count(page) == 1 guarantees the page is mapped exactly once.
488          * If any subpage of the compound page mapped with PTE it would elevate
489          * page_count().
490          */
491         if (page_count(page) == 1) {
492                 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
493                         locked, true);
494                 return;
495         }
496         for (i = 0; i < nr; i++, page++) {
497                 int mapcount = page_mapcount(page);
498                 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
499                 if (mapcount >= 2)
500                         pss /= mapcount;
501                 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
502                                       mapcount < 2);
503         }
504 }
505
506 #ifdef CONFIG_SHMEM
507 static int smaps_pte_hole(unsigned long addr, unsigned long end,
508                 struct mm_walk *walk)
509 {
510         struct mem_size_stats *mss = walk->private;
511
512         mss->swap += shmem_partial_swap_usage(
513                         walk->vma->vm_file->f_mapping, addr, end);
514
515         return 0;
516 }
517 #else
518 #define smaps_pte_hole          NULL
519 #endif /* CONFIG_SHMEM */
520
521 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
522                 struct mm_walk *walk)
523 {
524         struct mem_size_stats *mss = walk->private;
525         struct vm_area_struct *vma = walk->vma;
526         bool locked = !!(vma->vm_flags & VM_LOCKED);
527         struct page *page = NULL;
528
529         if (pte_present(*pte)) {
530                 page = vm_normal_page(vma, addr, *pte);
531         } else if (is_swap_pte(*pte)) {
532                 swp_entry_t swpent = pte_to_swp_entry(*pte);
533
534                 if (!non_swap_entry(swpent)) {
535                         int mapcount;
536
537                         mss->swap += PAGE_SIZE;
538                         mapcount = swp_swapcount(swpent);
539                         if (mapcount >= 2) {
540                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
541
542                                 do_div(pss_delta, mapcount);
543                                 mss->swap_pss += pss_delta;
544                         } else {
545                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
546                         }
547                 } else if (is_migration_entry(swpent))
548                         page = migration_entry_to_page(swpent);
549                 else if (is_device_private_entry(swpent))
550                         page = device_private_entry_to_page(swpent);
551         } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
552                                                         && pte_none(*pte))) {
553                 page = find_get_entry(vma->vm_file->f_mapping,
554                                                 linear_page_index(vma, addr));
555                 if (!page)
556                         return;
557
558                 if (xa_is_value(page))
559                         mss->swap += PAGE_SIZE;
560                 else
561                         put_page(page);
562
563                 return;
564         }
565
566         if (!page)
567                 return;
568
569         smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
570 }
571
572 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
573 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
574                 struct mm_walk *walk)
575 {
576         struct mem_size_stats *mss = walk->private;
577         struct vm_area_struct *vma = walk->vma;
578         bool locked = !!(vma->vm_flags & VM_LOCKED);
579         struct page *page;
580
581         /* FOLL_DUMP will return -EFAULT on huge zero page */
582         page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
583         if (IS_ERR_OR_NULL(page))
584                 return;
585         if (PageAnon(page))
586                 mss->anonymous_thp += HPAGE_PMD_SIZE;
587         else if (PageSwapBacked(page))
588                 mss->shmem_thp += HPAGE_PMD_SIZE;
589         else if (is_zone_device_page(page))
590                 /* pass */;
591         else
592                 mss->file_thp += HPAGE_PMD_SIZE;
593         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
594 }
595 #else
596 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
597                 struct mm_walk *walk)
598 {
599 }
600 #endif
601
602 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
603                            struct mm_walk *walk)
604 {
605         struct vm_area_struct *vma = walk->vma;
606         pte_t *pte;
607         spinlock_t *ptl;
608
609         ptl = pmd_trans_huge_lock(pmd, vma);
610         if (ptl) {
611                 if (pmd_present(*pmd))
612                         smaps_pmd_entry(pmd, addr, walk);
613                 spin_unlock(ptl);
614                 goto out;
615         }
616
617         if (pmd_trans_unstable(pmd))
618                 goto out;
619         /*
620          * The mmap_sem held all the way back in m_start() is what
621          * keeps khugepaged out of here and from collapsing things
622          * in here.
623          */
624         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
625         for (; addr != end; pte++, addr += PAGE_SIZE)
626                 smaps_pte_entry(pte, addr, walk);
627         pte_unmap_unlock(pte - 1, ptl);
628 out:
629         cond_resched();
630         return 0;
631 }
632
633 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
634 {
635         /*
636          * Don't forget to update Documentation/ on changes.
637          */
638         static const char mnemonics[BITS_PER_LONG][2] = {
639                 /*
640                  * In case if we meet a flag we don't know about.
641                  */
642                 [0 ... (BITS_PER_LONG-1)] = "??",
643
644                 [ilog2(VM_READ)]        = "rd",
645                 [ilog2(VM_WRITE)]       = "wr",
646                 [ilog2(VM_EXEC)]        = "ex",
647                 [ilog2(VM_SHARED)]      = "sh",
648                 [ilog2(VM_MAYREAD)]     = "mr",
649                 [ilog2(VM_MAYWRITE)]    = "mw",
650                 [ilog2(VM_MAYEXEC)]     = "me",
651                 [ilog2(VM_MAYSHARE)]    = "ms",
652                 [ilog2(VM_GROWSDOWN)]   = "gd",
653                 [ilog2(VM_PFNMAP)]      = "pf",
654                 [ilog2(VM_DENYWRITE)]   = "dw",
655 #ifdef CONFIG_X86_INTEL_MPX
656                 [ilog2(VM_MPX)]         = "mp",
657 #endif
658                 [ilog2(VM_LOCKED)]      = "lo",
659                 [ilog2(VM_IO)]          = "io",
660                 [ilog2(VM_SEQ_READ)]    = "sr",
661                 [ilog2(VM_RAND_READ)]   = "rr",
662                 [ilog2(VM_DONTCOPY)]    = "dc",
663                 [ilog2(VM_DONTEXPAND)]  = "de",
664                 [ilog2(VM_ACCOUNT)]     = "ac",
665                 [ilog2(VM_NORESERVE)]   = "nr",
666                 [ilog2(VM_HUGETLB)]     = "ht",
667                 [ilog2(VM_SYNC)]        = "sf",
668                 [ilog2(VM_ARCH_1)]      = "ar",
669                 [ilog2(VM_WIPEONFORK)]  = "wf",
670                 [ilog2(VM_DONTDUMP)]    = "dd",
671 #ifdef CONFIG_MEM_SOFT_DIRTY
672                 [ilog2(VM_SOFTDIRTY)]   = "sd",
673 #endif
674                 [ilog2(VM_MIXEDMAP)]    = "mm",
675                 [ilog2(VM_HUGEPAGE)]    = "hg",
676                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
677                 [ilog2(VM_MERGEABLE)]   = "mg",
678                 [ilog2(VM_UFFD_MISSING)]= "um",
679                 [ilog2(VM_UFFD_WP)]     = "uw",
680 #ifdef CONFIG_ARCH_HAS_PKEYS
681                 /* These come out via ProtectionKey: */
682                 [ilog2(VM_PKEY_BIT0)]   = "",
683                 [ilog2(VM_PKEY_BIT1)]   = "",
684                 [ilog2(VM_PKEY_BIT2)]   = "",
685                 [ilog2(VM_PKEY_BIT3)]   = "",
686 #if VM_PKEY_BIT4
687                 [ilog2(VM_PKEY_BIT4)]   = "",
688 #endif
689 #endif /* CONFIG_ARCH_HAS_PKEYS */
690         };
691         size_t i;
692
693         seq_puts(m, "VmFlags: ");
694         for (i = 0; i < BITS_PER_LONG; i++) {
695                 if (!mnemonics[i][0])
696                         continue;
697                 if (vma->vm_flags & (1UL << i)) {
698                         seq_putc(m, mnemonics[i][0]);
699                         seq_putc(m, mnemonics[i][1]);
700                         seq_putc(m, ' ');
701                 }
702         }
703         seq_putc(m, '\n');
704 }
705
706 #ifdef CONFIG_HUGETLB_PAGE
707 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
708                                  unsigned long addr, unsigned long end,
709                                  struct mm_walk *walk)
710 {
711         struct mem_size_stats *mss = walk->private;
712         struct vm_area_struct *vma = walk->vma;
713         struct page *page = NULL;
714
715         if (pte_present(*pte)) {
716                 page = vm_normal_page(vma, addr, *pte);
717         } else if (is_swap_pte(*pte)) {
718                 swp_entry_t swpent = pte_to_swp_entry(*pte);
719
720                 if (is_migration_entry(swpent))
721                         page = migration_entry_to_page(swpent);
722                 else if (is_device_private_entry(swpent))
723                         page = device_private_entry_to_page(swpent);
724         }
725         if (page) {
726                 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
727                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
728                 else
729                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
730         }
731         return 0;
732 }
733 #else
734 #define smaps_hugetlb_range     NULL
735 #endif /* HUGETLB_PAGE */
736
737 static const struct mm_walk_ops smaps_walk_ops = {
738         .pmd_entry              = smaps_pte_range,
739         .hugetlb_entry          = smaps_hugetlb_range,
740 };
741
742 static const struct mm_walk_ops smaps_shmem_walk_ops = {
743         .pmd_entry              = smaps_pte_range,
744         .hugetlb_entry          = smaps_hugetlb_range,
745         .pte_hole               = smaps_pte_hole,
746 };
747
748 static void smap_gather_stats(struct vm_area_struct *vma,
749                              struct mem_size_stats *mss)
750 {
751 #ifdef CONFIG_SHMEM
752         /* In case of smaps_rollup, reset the value from previous vma */
753         mss->check_shmem_swap = false;
754         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
755                 /*
756                  * For shared or readonly shmem mappings we know that all
757                  * swapped out pages belong to the shmem object, and we can
758                  * obtain the swap value much more efficiently. For private
759                  * writable mappings, we might have COW pages that are
760                  * not affected by the parent swapped out pages of the shmem
761                  * object, so we have to distinguish them during the page walk.
762                  * Unless we know that the shmem object (or the part mapped by
763                  * our VMA) has no swapped out pages at all.
764                  */
765                 unsigned long shmem_swapped = shmem_swap_usage(vma);
766
767                 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
768                                         !(vma->vm_flags & VM_WRITE)) {
769                         mss->swap += shmem_swapped;
770                 } else {
771                         mss->check_shmem_swap = true;
772                         walk_page_vma(vma, &smaps_shmem_walk_ops, mss);
773                         return;
774                 }
775         }
776 #endif
777         /* mmap_sem is held in m_start */
778         walk_page_vma(vma, &smaps_walk_ops, mss);
779 }
780
781 #define SEQ_PUT_DEC(str, val) \
782                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
783
784 /* Show the contents common for smaps and smaps_rollup */
785 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
786         bool rollup_mode)
787 {
788         SEQ_PUT_DEC("Rss:            ", mss->resident);
789         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
790         if (rollup_mode) {
791                 /*
792                  * These are meaningful only for smaps_rollup, otherwise two of
793                  * them are zero, and the other one is the same as Pss.
794                  */
795                 SEQ_PUT_DEC(" kB\nPss_Anon:       ",
796                         mss->pss_anon >> PSS_SHIFT);
797                 SEQ_PUT_DEC(" kB\nPss_File:       ",
798                         mss->pss_file >> PSS_SHIFT);
799                 SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
800                         mss->pss_shmem >> PSS_SHIFT);
801         }
802         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
803         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
804         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
805         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
806         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
807         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
808         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
809         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
810         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
811         SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp);
812         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
813         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
814                                   mss->private_hugetlb >> 10, 7);
815         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
816         SEQ_PUT_DEC(" kB\nSwapPss:        ",
817                                         mss->swap_pss >> PSS_SHIFT);
818         SEQ_PUT_DEC(" kB\nLocked:         ",
819                                         mss->pss_locked >> PSS_SHIFT);
820         seq_puts(m, " kB\n");
821 }
822
823 static int show_smap(struct seq_file *m, void *v)
824 {
825         struct vm_area_struct *vma = v;
826         struct mem_size_stats mss;
827
828         memset(&mss, 0, sizeof(mss));
829
830         smap_gather_stats(vma, &mss);
831
832         show_map_vma(m, vma);
833
834         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
835         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
836         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
837         seq_puts(m, " kB\n");
838
839         __show_smap(m, &mss, false);
840
841         seq_printf(m, "THPeligible:             %d\n",
842                    transparent_hugepage_enabled(vma));
843
844         if (arch_pkeys_enabled())
845                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
846         show_smap_vma_flags(m, vma);
847
848         m_cache_vma(m, vma);
849
850         return 0;
851 }
852
853 static int show_smaps_rollup(struct seq_file *m, void *v)
854 {
855         struct proc_maps_private *priv = m->private;
856         struct mem_size_stats mss;
857         struct mm_struct *mm;
858         struct vm_area_struct *vma;
859         unsigned long last_vma_end = 0;
860         int ret = 0;
861
862         priv->task = get_proc_task(priv->inode);
863         if (!priv->task)
864                 return -ESRCH;
865
866         mm = priv->mm;
867         if (!mm || !mmget_not_zero(mm)) {
868                 ret = -ESRCH;
869                 goto out_put_task;
870         }
871
872         memset(&mss, 0, sizeof(mss));
873
874         ret = down_read_killable(&mm->mmap_sem);
875         if (ret)
876                 goto out_put_mm;
877
878         hold_task_mempolicy(priv);
879
880         for (vma = priv->mm->mmap; vma; vma = vma->vm_next) {
881                 smap_gather_stats(vma, &mss);
882                 last_vma_end = vma->vm_end;
883         }
884
885         show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0,
886                                last_vma_end, 0, 0, 0, 0);
887         seq_pad(m, ' ');
888         seq_puts(m, "[rollup]\n");
889
890         __show_smap(m, &mss, true);
891
892         release_task_mempolicy(priv);
893         up_read(&mm->mmap_sem);
894
895 out_put_mm:
896         mmput(mm);
897 out_put_task:
898         put_task_struct(priv->task);
899         priv->task = NULL;
900
901         return ret;
902 }
903 #undef SEQ_PUT_DEC
904
905 static const struct seq_operations proc_pid_smaps_op = {
906         .start  = m_start,
907         .next   = m_next,
908         .stop   = m_stop,
909         .show   = show_smap
910 };
911
912 static int pid_smaps_open(struct inode *inode, struct file *file)
913 {
914         return do_maps_open(inode, file, &proc_pid_smaps_op);
915 }
916
917 static int smaps_rollup_open(struct inode *inode, struct file *file)
918 {
919         int ret;
920         struct proc_maps_private *priv;
921
922         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
923         if (!priv)
924                 return -ENOMEM;
925
926         ret = single_open(file, show_smaps_rollup, priv);
927         if (ret)
928                 goto out_free;
929
930         priv->inode = inode;
931         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
932         if (IS_ERR(priv->mm)) {
933                 ret = PTR_ERR(priv->mm);
934
935                 single_release(inode, file);
936                 goto out_free;
937         }
938
939         return 0;
940
941 out_free:
942         kfree(priv);
943         return ret;
944 }
945
946 static int smaps_rollup_release(struct inode *inode, struct file *file)
947 {
948         struct seq_file *seq = file->private_data;
949         struct proc_maps_private *priv = seq->private;
950
951         if (priv->mm)
952                 mmdrop(priv->mm);
953
954         kfree(priv);
955         return single_release(inode, file);
956 }
957
958 const struct file_operations proc_pid_smaps_operations = {
959         .open           = pid_smaps_open,
960         .read           = seq_read,
961         .llseek         = seq_lseek,
962         .release        = proc_map_release,
963 };
964
965 const struct file_operations proc_pid_smaps_rollup_operations = {
966         .open           = smaps_rollup_open,
967         .read           = seq_read,
968         .llseek         = seq_lseek,
969         .release        = smaps_rollup_release,
970 };
971
972 enum clear_refs_types {
973         CLEAR_REFS_ALL = 1,
974         CLEAR_REFS_ANON,
975         CLEAR_REFS_MAPPED,
976         CLEAR_REFS_SOFT_DIRTY,
977         CLEAR_REFS_MM_HIWATER_RSS,
978         CLEAR_REFS_LAST,
979 };
980
981 struct clear_refs_private {
982         enum clear_refs_types type;
983 };
984
985 #ifdef CONFIG_MEM_SOFT_DIRTY
986 static inline void clear_soft_dirty(struct vm_area_struct *vma,
987                 unsigned long addr, pte_t *pte)
988 {
989         /*
990          * The soft-dirty tracker uses #PF-s to catch writes
991          * to pages, so write-protect the pte as well. See the
992          * Documentation/admin-guide/mm/soft-dirty.rst for full description
993          * of how soft-dirty works.
994          */
995         pte_t ptent = *pte;
996
997         if (pte_present(ptent)) {
998                 pte_t old_pte;
999
1000                 old_pte = ptep_modify_prot_start(vma, addr, pte);
1001                 ptent = pte_wrprotect(old_pte);
1002                 ptent = pte_clear_soft_dirty(ptent);
1003                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1004         } else if (is_swap_pte(ptent)) {
1005                 ptent = pte_swp_clear_soft_dirty(ptent);
1006                 set_pte_at(vma->vm_mm, addr, pte, ptent);
1007         }
1008 }
1009 #else
1010 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1011                 unsigned long addr, pte_t *pte)
1012 {
1013 }
1014 #endif
1015
1016 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1017 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1018                 unsigned long addr, pmd_t *pmdp)
1019 {
1020         pmd_t old, pmd = *pmdp;
1021
1022         if (pmd_present(pmd)) {
1023                 /* See comment in change_huge_pmd() */
1024                 old = pmdp_invalidate(vma, addr, pmdp);
1025                 if (pmd_dirty(old))
1026                         pmd = pmd_mkdirty(pmd);
1027                 if (pmd_young(old))
1028                         pmd = pmd_mkyoung(pmd);
1029
1030                 pmd = pmd_wrprotect(pmd);
1031                 pmd = pmd_clear_soft_dirty(pmd);
1032
1033                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1034         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1035                 pmd = pmd_swp_clear_soft_dirty(pmd);
1036                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1037         }
1038 }
1039 #else
1040 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1041                 unsigned long addr, pmd_t *pmdp)
1042 {
1043 }
1044 #endif
1045
1046 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1047                                 unsigned long end, struct mm_walk *walk)
1048 {
1049         struct clear_refs_private *cp = walk->private;
1050         struct vm_area_struct *vma = walk->vma;
1051         pte_t *pte, ptent;
1052         spinlock_t *ptl;
1053         struct page *page;
1054
1055         ptl = pmd_trans_huge_lock(pmd, vma);
1056         if (ptl) {
1057                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1058                         clear_soft_dirty_pmd(vma, addr, pmd);
1059                         goto out;
1060                 }
1061
1062                 if (!pmd_present(*pmd))
1063                         goto out;
1064
1065                 page = pmd_page(*pmd);
1066
1067                 /* Clear accessed and referenced bits. */
1068                 pmdp_test_and_clear_young(vma, addr, pmd);
1069                 test_and_clear_page_young(page);
1070                 ClearPageReferenced(page);
1071 out:
1072                 spin_unlock(ptl);
1073                 return 0;
1074         }
1075
1076         if (pmd_trans_unstable(pmd))
1077                 return 0;
1078
1079         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1080         for (; addr != end; pte++, addr += PAGE_SIZE) {
1081                 ptent = *pte;
1082
1083                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1084                         clear_soft_dirty(vma, addr, pte);
1085                         continue;
1086                 }
1087
1088                 if (!pte_present(ptent))
1089                         continue;
1090
1091                 page = vm_normal_page(vma, addr, ptent);
1092                 if (!page)
1093                         continue;
1094
1095                 /* Clear accessed and referenced bits. */
1096                 ptep_test_and_clear_young(vma, addr, pte);
1097                 test_and_clear_page_young(page);
1098                 ClearPageReferenced(page);
1099         }
1100         pte_unmap_unlock(pte - 1, ptl);
1101         cond_resched();
1102         return 0;
1103 }
1104
1105 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1106                                 struct mm_walk *walk)
1107 {
1108         struct clear_refs_private *cp = walk->private;
1109         struct vm_area_struct *vma = walk->vma;
1110
1111         if (vma->vm_flags & VM_PFNMAP)
1112                 return 1;
1113
1114         /*
1115          * Writing 1 to /proc/pid/clear_refs affects all pages.
1116          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1117          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1118          * Writing 4 to /proc/pid/clear_refs affects all pages.
1119          */
1120         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1121                 return 1;
1122         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1123                 return 1;
1124         return 0;
1125 }
1126
1127 static const struct mm_walk_ops clear_refs_walk_ops = {
1128         .pmd_entry              = clear_refs_pte_range,
1129         .test_walk              = clear_refs_test_walk,
1130 };
1131
1132 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1133                                 size_t count, loff_t *ppos)
1134 {
1135         struct task_struct *task;
1136         char buffer[PROC_NUMBUF];
1137         struct mm_struct *mm;
1138         struct vm_area_struct *vma;
1139         enum clear_refs_types type;
1140         struct mmu_gather tlb;
1141         int itype;
1142         int rv;
1143
1144         memset(buffer, 0, sizeof(buffer));
1145         if (count > sizeof(buffer) - 1)
1146                 count = sizeof(buffer) - 1;
1147         if (copy_from_user(buffer, buf, count))
1148                 return -EFAULT;
1149         rv = kstrtoint(strstrip(buffer), 10, &itype);
1150         if (rv < 0)
1151                 return rv;
1152         type = (enum clear_refs_types)itype;
1153         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1154                 return -EINVAL;
1155
1156         task = get_proc_task(file_inode(file));
1157         if (!task)
1158                 return -ESRCH;
1159         mm = get_task_mm(task);
1160         if (mm) {
1161                 struct mmu_notifier_range range;
1162                 struct clear_refs_private cp = {
1163                         .type = type,
1164                 };
1165
1166                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1167                         if (down_write_killable(&mm->mmap_sem)) {
1168                                 count = -EINTR;
1169                                 goto out_mm;
1170                         }
1171
1172                         /*
1173                          * Writing 5 to /proc/pid/clear_refs resets the peak
1174                          * resident set size to this mm's current rss value.
1175                          */
1176                         reset_mm_hiwater_rss(mm);
1177                         up_write(&mm->mmap_sem);
1178                         goto out_mm;
1179                 }
1180
1181                 if (down_read_killable(&mm->mmap_sem)) {
1182                         count = -EINTR;
1183                         goto out_mm;
1184                 }
1185                 tlb_gather_mmu(&tlb, mm, 0, -1);
1186                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1187                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1188                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1189                                         continue;
1190                                 up_read(&mm->mmap_sem);
1191                                 if (down_write_killable(&mm->mmap_sem)) {
1192                                         count = -EINTR;
1193                                         goto out_mm;
1194                                 }
1195                                 /*
1196                                  * Avoid to modify vma->vm_flags
1197                                  * without locked ops while the
1198                                  * coredump reads the vm_flags.
1199                                  */
1200                                 if (!mmget_still_valid(mm)) {
1201                                         /*
1202                                          * Silently return "count"
1203                                          * like if get_task_mm()
1204                                          * failed. FIXME: should this
1205                                          * function have returned
1206                                          * -ESRCH if get_task_mm()
1207                                          * failed like if
1208                                          * get_proc_task() fails?
1209                                          */
1210                                         up_write(&mm->mmap_sem);
1211                                         goto out_mm;
1212                                 }
1213                                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1214                                         vma->vm_flags &= ~VM_SOFTDIRTY;
1215                                         vma_set_page_prot(vma);
1216                                 }
1217                                 downgrade_write(&mm->mmap_sem);
1218                                 break;
1219                         }
1220
1221                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1222                                                 0, NULL, mm, 0, -1UL);
1223                         mmu_notifier_invalidate_range_start(&range);
1224                 }
1225                 walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
1226                                 &cp);
1227                 if (type == CLEAR_REFS_SOFT_DIRTY)
1228                         mmu_notifier_invalidate_range_end(&range);
1229                 tlb_finish_mmu(&tlb, 0, -1);
1230                 up_read(&mm->mmap_sem);
1231 out_mm:
1232                 mmput(mm);
1233         }
1234         put_task_struct(task);
1235
1236         return count;
1237 }
1238
1239 const struct file_operations proc_clear_refs_operations = {
1240         .write          = clear_refs_write,
1241         .llseek         = noop_llseek,
1242 };
1243
1244 typedef struct {
1245         u64 pme;
1246 } pagemap_entry_t;
1247
1248 struct pagemapread {
1249         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1250         pagemap_entry_t *buffer;
1251         bool show_pfn;
1252 };
1253
1254 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1255 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1256
1257 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1258 #define PM_PFRAME_BITS          55
1259 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1260 #define PM_SOFT_DIRTY           BIT_ULL(55)
1261 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1262 #define PM_FILE                 BIT_ULL(61)
1263 #define PM_SWAP                 BIT_ULL(62)
1264 #define PM_PRESENT              BIT_ULL(63)
1265
1266 #define PM_END_OF_BUFFER    1
1267
1268 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1269 {
1270         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1271 }
1272
1273 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1274                           struct pagemapread *pm)
1275 {
1276         pm->buffer[pm->pos++] = *pme;
1277         if (pm->pos >= pm->len)
1278                 return PM_END_OF_BUFFER;
1279         return 0;
1280 }
1281
1282 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1283                                 struct mm_walk *walk)
1284 {
1285         struct pagemapread *pm = walk->private;
1286         unsigned long addr = start;
1287         int err = 0;
1288
1289         while (addr < end) {
1290                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1291                 pagemap_entry_t pme = make_pme(0, 0);
1292                 /* End of address space hole, which we mark as non-present. */
1293                 unsigned long hole_end;
1294
1295                 if (vma)
1296                         hole_end = min(end, vma->vm_start);
1297                 else
1298                         hole_end = end;
1299
1300                 for (; addr < hole_end; addr += PAGE_SIZE) {
1301                         err = add_to_pagemap(addr, &pme, pm);
1302                         if (err)
1303                                 goto out;
1304                 }
1305
1306                 if (!vma)
1307                         break;
1308
1309                 /* Addresses in the VMA. */
1310                 if (vma->vm_flags & VM_SOFTDIRTY)
1311                         pme = make_pme(0, PM_SOFT_DIRTY);
1312                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1313                         err = add_to_pagemap(addr, &pme, pm);
1314                         if (err)
1315                                 goto out;
1316                 }
1317         }
1318 out:
1319         return err;
1320 }
1321
1322 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1323                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1324 {
1325         u64 frame = 0, flags = 0;
1326         struct page *page = NULL;
1327
1328         if (pte_present(pte)) {
1329                 if (pm->show_pfn)
1330                         frame = pte_pfn(pte);
1331                 flags |= PM_PRESENT;
1332                 page = vm_normal_page(vma, addr, pte);
1333                 if (pte_soft_dirty(pte))
1334                         flags |= PM_SOFT_DIRTY;
1335         } else if (is_swap_pte(pte)) {
1336                 swp_entry_t entry;
1337                 if (pte_swp_soft_dirty(pte))
1338                         flags |= PM_SOFT_DIRTY;
1339                 entry = pte_to_swp_entry(pte);
1340                 if (pm->show_pfn)
1341                         frame = swp_type(entry) |
1342                                 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1343                 flags |= PM_SWAP;
1344                 if (is_migration_entry(entry))
1345                         page = migration_entry_to_page(entry);
1346
1347                 if (is_device_private_entry(entry))
1348                         page = device_private_entry_to_page(entry);
1349         }
1350
1351         if (page && !PageAnon(page))
1352                 flags |= PM_FILE;
1353         if (page && page_mapcount(page) == 1)
1354                 flags |= PM_MMAP_EXCLUSIVE;
1355         if (vma->vm_flags & VM_SOFTDIRTY)
1356                 flags |= PM_SOFT_DIRTY;
1357
1358         return make_pme(frame, flags);
1359 }
1360
1361 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1362                              struct mm_walk *walk)
1363 {
1364         struct vm_area_struct *vma = walk->vma;
1365         struct pagemapread *pm = walk->private;
1366         spinlock_t *ptl;
1367         pte_t *pte, *orig_pte;
1368         int err = 0;
1369
1370 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1371         ptl = pmd_trans_huge_lock(pmdp, vma);
1372         if (ptl) {
1373                 u64 flags = 0, frame = 0;
1374                 pmd_t pmd = *pmdp;
1375                 struct page *page = NULL;
1376
1377                 if (vma->vm_flags & VM_SOFTDIRTY)
1378                         flags |= PM_SOFT_DIRTY;
1379
1380                 if (pmd_present(pmd)) {
1381                         page = pmd_page(pmd);
1382
1383                         flags |= PM_PRESENT;
1384                         if (pmd_soft_dirty(pmd))
1385                                 flags |= PM_SOFT_DIRTY;
1386                         if (pm->show_pfn)
1387                                 frame = pmd_pfn(pmd) +
1388                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1389                 }
1390 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1391                 else if (is_swap_pmd(pmd)) {
1392                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1393                         unsigned long offset;
1394
1395                         if (pm->show_pfn) {
1396                                 offset = swp_offset(entry) +
1397                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1398                                 frame = swp_type(entry) |
1399                                         (offset << MAX_SWAPFILES_SHIFT);
1400                         }
1401                         flags |= PM_SWAP;
1402                         if (pmd_swp_soft_dirty(pmd))
1403                                 flags |= PM_SOFT_DIRTY;
1404                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1405                         page = migration_entry_to_page(entry);
1406                 }
1407 #endif
1408
1409                 if (page && page_mapcount(page) == 1)
1410                         flags |= PM_MMAP_EXCLUSIVE;
1411
1412                 for (; addr != end; addr += PAGE_SIZE) {
1413                         pagemap_entry_t pme = make_pme(frame, flags);
1414
1415                         err = add_to_pagemap(addr, &pme, pm);
1416                         if (err)
1417                                 break;
1418                         if (pm->show_pfn) {
1419                                 if (flags & PM_PRESENT)
1420                                         frame++;
1421                                 else if (flags & PM_SWAP)
1422                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1423                         }
1424                 }
1425                 spin_unlock(ptl);
1426                 return err;
1427         }
1428
1429         if (pmd_trans_unstable(pmdp))
1430                 return 0;
1431 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1432
1433         /*
1434          * We can assume that @vma always points to a valid one and @end never
1435          * goes beyond vma->vm_end.
1436          */
1437         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1438         for (; addr < end; pte++, addr += PAGE_SIZE) {
1439                 pagemap_entry_t pme;
1440
1441                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1442                 err = add_to_pagemap(addr, &pme, pm);
1443                 if (err)
1444                         break;
1445         }
1446         pte_unmap_unlock(orig_pte, ptl);
1447
1448         cond_resched();
1449
1450         return err;
1451 }
1452
1453 #ifdef CONFIG_HUGETLB_PAGE
1454 /* This function walks within one hugetlb entry in the single call */
1455 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1456                                  unsigned long addr, unsigned long end,
1457                                  struct mm_walk *walk)
1458 {
1459         struct pagemapread *pm = walk->private;
1460         struct vm_area_struct *vma = walk->vma;
1461         u64 flags = 0, frame = 0;
1462         int err = 0;
1463         pte_t pte;
1464
1465         if (vma->vm_flags & VM_SOFTDIRTY)
1466                 flags |= PM_SOFT_DIRTY;
1467
1468         pte = huge_ptep_get(ptep);
1469         if (pte_present(pte)) {
1470                 struct page *page = pte_page(pte);
1471
1472                 if (!PageAnon(page))
1473                         flags |= PM_FILE;
1474
1475                 if (page_mapcount(page) == 1)
1476                         flags |= PM_MMAP_EXCLUSIVE;
1477
1478                 flags |= PM_PRESENT;
1479                 if (pm->show_pfn)
1480                         frame = pte_pfn(pte) +
1481                                 ((addr & ~hmask) >> PAGE_SHIFT);
1482         }
1483
1484         for (; addr != end; addr += PAGE_SIZE) {
1485                 pagemap_entry_t pme = make_pme(frame, flags);
1486
1487                 err = add_to_pagemap(addr, &pme, pm);
1488                 if (err)
1489                         return err;
1490                 if (pm->show_pfn && (flags & PM_PRESENT))
1491                         frame++;
1492         }
1493
1494         cond_resched();
1495
1496         return err;
1497 }
1498 #else
1499 #define pagemap_hugetlb_range   NULL
1500 #endif /* HUGETLB_PAGE */
1501
1502 static const struct mm_walk_ops pagemap_ops = {
1503         .pmd_entry      = pagemap_pmd_range,
1504         .pte_hole       = pagemap_pte_hole,
1505         .hugetlb_entry  = pagemap_hugetlb_range,
1506 };
1507
1508 /*
1509  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1510  *
1511  * For each page in the address space, this file contains one 64-bit entry
1512  * consisting of the following:
1513  *
1514  * Bits 0-54  page frame number (PFN) if present
1515  * Bits 0-4   swap type if swapped
1516  * Bits 5-54  swap offset if swapped
1517  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1518  * Bit  56    page exclusively mapped
1519  * Bits 57-60 zero
1520  * Bit  61    page is file-page or shared-anon
1521  * Bit  62    page swapped
1522  * Bit  63    page present
1523  *
1524  * If the page is not present but in swap, then the PFN contains an
1525  * encoding of the swap file number and the page's offset into the
1526  * swap. Unmapped pages return a null PFN. This allows determining
1527  * precisely which pages are mapped (or in swap) and comparing mapped
1528  * pages between processes.
1529  *
1530  * Efficient users of this interface will use /proc/pid/maps to
1531  * determine which areas of memory are actually mapped and llseek to
1532  * skip over unmapped regions.
1533  */
1534 static ssize_t pagemap_read(struct file *file, char __user *buf,
1535                             size_t count, loff_t *ppos)
1536 {
1537         struct mm_struct *mm = file->private_data;
1538         struct pagemapread pm;
1539         unsigned long src;
1540         unsigned long svpfn;
1541         unsigned long start_vaddr;
1542         unsigned long end_vaddr;
1543         int ret = 0, copied = 0;
1544
1545         if (!mm || !mmget_not_zero(mm))
1546                 goto out;
1547
1548         ret = -EINVAL;
1549         /* file position must be aligned */
1550         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1551                 goto out_mm;
1552
1553         ret = 0;
1554         if (!count)
1555                 goto out_mm;
1556
1557         /* do not disclose physical addresses: attack vector */
1558         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1559
1560         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1561         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1562         ret = -ENOMEM;
1563         if (!pm.buffer)
1564                 goto out_mm;
1565
1566         src = *ppos;
1567         svpfn = src / PM_ENTRY_BYTES;
1568         end_vaddr = mm->task_size;
1569
1570         /* watch out for wraparound */
1571         start_vaddr = end_vaddr;
1572         if (svpfn <= (ULONG_MAX >> PAGE_SHIFT))
1573                 start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
1574
1575         /* Ensure the address is inside the task */
1576         if (start_vaddr > mm->task_size)
1577                 start_vaddr = end_vaddr;
1578
1579         /*
1580          * The odds are that this will stop walking way
1581          * before end_vaddr, because the length of the
1582          * user buffer is tracked in "pm", and the walk
1583          * will stop when we hit the end of the buffer.
1584          */
1585         ret = 0;
1586         while (count && (start_vaddr < end_vaddr)) {
1587                 int len;
1588                 unsigned long end;
1589
1590                 pm.pos = 0;
1591                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1592                 /* overflow ? */
1593                 if (end < start_vaddr || end > end_vaddr)
1594                         end = end_vaddr;
1595                 ret = down_read_killable(&mm->mmap_sem);
1596                 if (ret)
1597                         goto out_free;
1598                 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1599                 up_read(&mm->mmap_sem);
1600                 start_vaddr = end;
1601
1602                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1603                 if (copy_to_user(buf, pm.buffer, len)) {
1604                         ret = -EFAULT;
1605                         goto out_free;
1606                 }
1607                 copied += len;
1608                 buf += len;
1609                 count -= len;
1610         }
1611         *ppos += copied;
1612         if (!ret || ret == PM_END_OF_BUFFER)
1613                 ret = copied;
1614
1615 out_free:
1616         kfree(pm.buffer);
1617 out_mm:
1618         mmput(mm);
1619 out:
1620         return ret;
1621 }
1622
1623 static int pagemap_open(struct inode *inode, struct file *file)
1624 {
1625         struct mm_struct *mm;
1626
1627         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1628         if (IS_ERR(mm))
1629                 return PTR_ERR(mm);
1630         file->private_data = mm;
1631         return 0;
1632 }
1633
1634 static int pagemap_release(struct inode *inode, struct file *file)
1635 {
1636         struct mm_struct *mm = file->private_data;
1637
1638         if (mm)
1639                 mmdrop(mm);
1640         return 0;
1641 }
1642
1643 const struct file_operations proc_pagemap_operations = {
1644         .llseek         = mem_lseek, /* borrow this */
1645         .read           = pagemap_read,
1646         .open           = pagemap_open,
1647         .release        = pagemap_release,
1648 };
1649 #endif /* CONFIG_PROC_PAGE_MONITOR */
1650
1651 #ifdef CONFIG_NUMA
1652
1653 struct numa_maps {
1654         unsigned long pages;
1655         unsigned long anon;
1656         unsigned long active;
1657         unsigned long writeback;
1658         unsigned long mapcount_max;
1659         unsigned long dirty;
1660         unsigned long swapcache;
1661         unsigned long node[MAX_NUMNODES];
1662 };
1663
1664 struct numa_maps_private {
1665         struct proc_maps_private proc_maps;
1666         struct numa_maps md;
1667 };
1668
1669 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1670                         unsigned long nr_pages)
1671 {
1672         int count = page_mapcount(page);
1673
1674         md->pages += nr_pages;
1675         if (pte_dirty || PageDirty(page))
1676                 md->dirty += nr_pages;
1677
1678         if (PageSwapCache(page))
1679                 md->swapcache += nr_pages;
1680
1681         if (PageActive(page) || PageUnevictable(page))
1682                 md->active += nr_pages;
1683
1684         if (PageWriteback(page))
1685                 md->writeback += nr_pages;
1686
1687         if (PageAnon(page))
1688                 md->anon += nr_pages;
1689
1690         if (count > md->mapcount_max)
1691                 md->mapcount_max = count;
1692
1693         md->node[page_to_nid(page)] += nr_pages;
1694 }
1695
1696 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1697                 unsigned long addr)
1698 {
1699         struct page *page;
1700         int nid;
1701
1702         if (!pte_present(pte))
1703                 return NULL;
1704
1705         page = vm_normal_page(vma, addr, pte);
1706         if (!page)
1707                 return NULL;
1708
1709         if (PageReserved(page))
1710                 return NULL;
1711
1712         nid = page_to_nid(page);
1713         if (!node_isset(nid, node_states[N_MEMORY]))
1714                 return NULL;
1715
1716         return page;
1717 }
1718
1719 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1720 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1721                                               struct vm_area_struct *vma,
1722                                               unsigned long addr)
1723 {
1724         struct page *page;
1725         int nid;
1726
1727         if (!pmd_present(pmd))
1728                 return NULL;
1729
1730         page = vm_normal_page_pmd(vma, addr, pmd);
1731         if (!page)
1732                 return NULL;
1733
1734         if (PageReserved(page))
1735                 return NULL;
1736
1737         nid = page_to_nid(page);
1738         if (!node_isset(nid, node_states[N_MEMORY]))
1739                 return NULL;
1740
1741         return page;
1742 }
1743 #endif
1744
1745 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1746                 unsigned long end, struct mm_walk *walk)
1747 {
1748         struct numa_maps *md = walk->private;
1749         struct vm_area_struct *vma = walk->vma;
1750         spinlock_t *ptl;
1751         pte_t *orig_pte;
1752         pte_t *pte;
1753
1754 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1755         ptl = pmd_trans_huge_lock(pmd, vma);
1756         if (ptl) {
1757                 struct page *page;
1758
1759                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1760                 if (page)
1761                         gather_stats(page, md, pmd_dirty(*pmd),
1762                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1763                 spin_unlock(ptl);
1764                 return 0;
1765         }
1766
1767         if (pmd_trans_unstable(pmd))
1768                 return 0;
1769 #endif
1770         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1771         do {
1772                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1773                 if (!page)
1774                         continue;
1775                 gather_stats(page, md, pte_dirty(*pte), 1);
1776
1777         } while (pte++, addr += PAGE_SIZE, addr != end);
1778         pte_unmap_unlock(orig_pte, ptl);
1779         cond_resched();
1780         return 0;
1781 }
1782 #ifdef CONFIG_HUGETLB_PAGE
1783 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1784                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1785 {
1786         pte_t huge_pte = huge_ptep_get(pte);
1787         struct numa_maps *md;
1788         struct page *page;
1789
1790         if (!pte_present(huge_pte))
1791                 return 0;
1792
1793         page = pte_page(huge_pte);
1794         if (!page)
1795                 return 0;
1796
1797         md = walk->private;
1798         gather_stats(page, md, pte_dirty(huge_pte), 1);
1799         return 0;
1800 }
1801
1802 #else
1803 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1804                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1805 {
1806         return 0;
1807 }
1808 #endif
1809
1810 static const struct mm_walk_ops show_numa_ops = {
1811         .hugetlb_entry = gather_hugetlb_stats,
1812         .pmd_entry = gather_pte_stats,
1813 };
1814
1815 /*
1816  * Display pages allocated per node and memory policy via /proc.
1817  */
1818 static int show_numa_map(struct seq_file *m, void *v)
1819 {
1820         struct numa_maps_private *numa_priv = m->private;
1821         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1822         struct vm_area_struct *vma = v;
1823         struct numa_maps *md = &numa_priv->md;
1824         struct file *file = vma->vm_file;
1825         struct mm_struct *mm = vma->vm_mm;
1826         struct mempolicy *pol;
1827         char buffer[64];
1828         int nid;
1829
1830         if (!mm)
1831                 return 0;
1832
1833         /* Ensure we start with an empty set of numa_maps statistics. */
1834         memset(md, 0, sizeof(*md));
1835
1836         pol = __get_vma_policy(vma, vma->vm_start);
1837         if (pol) {
1838                 mpol_to_str(buffer, sizeof(buffer), pol);
1839                 mpol_cond_put(pol);
1840         } else {
1841                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1842         }
1843
1844         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1845
1846         if (file) {
1847                 seq_puts(m, " file=");
1848                 seq_file_path(m, file, "\n\t= ");
1849         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1850                 seq_puts(m, " heap");
1851         } else if (is_stack(vma)) {
1852                 seq_puts(m, " stack");
1853         }
1854
1855         if (is_vm_hugetlb_page(vma))
1856                 seq_puts(m, " huge");
1857
1858         /* mmap_sem is held by m_start */
1859         walk_page_vma(vma, &show_numa_ops, md);
1860
1861         if (!md->pages)
1862                 goto out;
1863
1864         if (md->anon)
1865                 seq_printf(m, " anon=%lu", md->anon);
1866
1867         if (md->dirty)
1868                 seq_printf(m, " dirty=%lu", md->dirty);
1869
1870         if (md->pages != md->anon && md->pages != md->dirty)
1871                 seq_printf(m, " mapped=%lu", md->pages);
1872
1873         if (md->mapcount_max > 1)
1874                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1875
1876         if (md->swapcache)
1877                 seq_printf(m, " swapcache=%lu", md->swapcache);
1878
1879         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1880                 seq_printf(m, " active=%lu", md->active);
1881
1882         if (md->writeback)
1883                 seq_printf(m, " writeback=%lu", md->writeback);
1884
1885         for_each_node_state(nid, N_MEMORY)
1886                 if (md->node[nid])
1887                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1888
1889         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1890 out:
1891         seq_putc(m, '\n');
1892         m_cache_vma(m, vma);
1893         return 0;
1894 }
1895
1896 static const struct seq_operations proc_pid_numa_maps_op = {
1897         .start  = m_start,
1898         .next   = m_next,
1899         .stop   = m_stop,
1900         .show   = show_numa_map,
1901 };
1902
1903 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1904 {
1905         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1906                                 sizeof(struct numa_maps_private));
1907 }
1908
1909 const struct file_operations proc_pid_numa_maps_operations = {
1910         .open           = pid_numa_maps_open,
1911         .read           = seq_read,
1912         .llseek         = seq_lseek,
1913         .release        = proc_map_release,
1914 };
1915
1916 #endif /* CONFIG_NUMA */