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TOMOYO Linux Cross Reference
Linux/fs/proc/task_mmu.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 #include <linux/mm.h>
  3 #include <linux/vmacache.h>
  4 #include <linux/hugetlb.h>
  5 #include <linux/huge_mm.h>
  6 #include <linux/mount.h>
  7 #include <linux/seq_file.h>
  8 #include <linux/highmem.h>
  9 #include <linux/ptrace.h>
 10 #include <linux/slab.h>
 11 #include <linux/pagemap.h>
 12 #include <linux/mempolicy.h>
 13 #include <linux/rmap.h>
 14 #include <linux/swap.h>
 15 #include <linux/sched/mm.h>
 16 #include <linux/swapops.h>
 17 #include <linux/mmu_notifier.h>
 18 #include <linux/page_idle.h>
 19 #include <linux/shmem_fs.h>
 20 #include <linux/uaccess.h>
 21 #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 swap;
421         unsigned long shared_hugetlb;
422         unsigned long private_hugetlb;
423         u64 pss;
424         u64 pss_locked;
425         u64 swap_pss;
426         bool check_shmem_swap;
427 };
428 
429 static void smaps_account(struct mem_size_stats *mss, struct page *page,
430                 bool compound, bool young, bool dirty, bool locked)
431 {
432         int i, nr = compound ? 1 << compound_order(page) : 1;
433         unsigned long size = nr * PAGE_SIZE;
434 
435         if (PageAnon(page)) {
436                 mss->anonymous += size;
437                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
438                         mss->lazyfree += size;
439         }
440 
441         mss->resident += size;
442         /* Accumulate the size in pages that have been accessed. */
443         if (young || page_is_young(page) || PageReferenced(page))
444                 mss->referenced += size;
445 
446         /*
447          * page_count(page) == 1 guarantees the page is mapped exactly once.
448          * If any subpage of the compound page mapped with PTE it would elevate
449          * page_count().
450          */
451         if (page_count(page) == 1) {
452                 if (dirty || PageDirty(page))
453                         mss->private_dirty += size;
454                 else
455                         mss->private_clean += size;
456                 mss->pss += (u64)size << PSS_SHIFT;
457                 if (locked)
458                         mss->pss_locked += (u64)size << PSS_SHIFT;
459                 return;
460         }
461 
462         for (i = 0; i < nr; i++, page++) {
463                 int mapcount = page_mapcount(page);
464                 unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
465 
466                 if (mapcount >= 2) {
467                         if (dirty || PageDirty(page))
468                                 mss->shared_dirty += PAGE_SIZE;
469                         else
470                                 mss->shared_clean += PAGE_SIZE;
471                         mss->pss += pss / mapcount;
472                         if (locked)
473                                 mss->pss_locked += pss / mapcount;
474                 } else {
475                         if (dirty || PageDirty(page))
476                                 mss->private_dirty += PAGE_SIZE;
477                         else
478                                 mss->private_clean += PAGE_SIZE;
479                         mss->pss += pss;
480                         if (locked)
481                                 mss->pss_locked += pss;
482                 }
483         }
484 }
485 
486 #ifdef CONFIG_SHMEM
487 static int smaps_pte_hole(unsigned long addr, unsigned long end,
488                 struct mm_walk *walk)
489 {
490         struct mem_size_stats *mss = walk->private;
491 
492         mss->swap += shmem_partial_swap_usage(
493                         walk->vma->vm_file->f_mapping, addr, end);
494 
495         return 0;
496 }
497 #endif
498 
499 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
500                 struct mm_walk *walk)
501 {
502         struct mem_size_stats *mss = walk->private;
503         struct vm_area_struct *vma = walk->vma;
504         bool locked = !!(vma->vm_flags & VM_LOCKED);
505         struct page *page = NULL;
506 
507         if (pte_present(*pte)) {
508                 page = vm_normal_page(vma, addr, *pte);
509         } else if (is_swap_pte(*pte)) {
510                 swp_entry_t swpent = pte_to_swp_entry(*pte);
511 
512                 if (!non_swap_entry(swpent)) {
513                         int mapcount;
514 
515                         mss->swap += PAGE_SIZE;
516                         mapcount = swp_swapcount(swpent);
517                         if (mapcount >= 2) {
518                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
519 
520                                 do_div(pss_delta, mapcount);
521                                 mss->swap_pss += pss_delta;
522                         } else {
523                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
524                         }
525                 } else if (is_migration_entry(swpent))
526                         page = migration_entry_to_page(swpent);
527                 else if (is_device_private_entry(swpent))
528                         page = device_private_entry_to_page(swpent);
529         } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
530                                                         && pte_none(*pte))) {
531                 page = find_get_entry(vma->vm_file->f_mapping,
532                                                 linear_page_index(vma, addr));
533                 if (!page)
534                         return;
535 
536                 if (xa_is_value(page))
537                         mss->swap += PAGE_SIZE;
538                 else
539                         put_page(page);
540 
541                 return;
542         }
543 
544         if (!page)
545                 return;
546 
547         smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
548 }
549 
550 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
551 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
552                 struct mm_walk *walk)
553 {
554         struct mem_size_stats *mss = walk->private;
555         struct vm_area_struct *vma = walk->vma;
556         bool locked = !!(vma->vm_flags & VM_LOCKED);
557         struct page *page;
558 
559         /* FOLL_DUMP will return -EFAULT on huge zero page */
560         page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
561         if (IS_ERR_OR_NULL(page))
562                 return;
563         if (PageAnon(page))
564                 mss->anonymous_thp += HPAGE_PMD_SIZE;
565         else if (PageSwapBacked(page))
566                 mss->shmem_thp += HPAGE_PMD_SIZE;
567         else if (is_zone_device_page(page))
568                 /* pass */;
569         else
570                 VM_BUG_ON_PAGE(1, page);
571         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
572 }
573 #else
574 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
575                 struct mm_walk *walk)
576 {
577 }
578 #endif
579 
580 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
581                            struct mm_walk *walk)
582 {
583         struct vm_area_struct *vma = walk->vma;
584         pte_t *pte;
585         spinlock_t *ptl;
586 
587         ptl = pmd_trans_huge_lock(pmd, vma);
588         if (ptl) {
589                 if (pmd_present(*pmd))
590                         smaps_pmd_entry(pmd, addr, walk);
591                 spin_unlock(ptl);
592                 goto out;
593         }
594 
595         if (pmd_trans_unstable(pmd))
596                 goto out;
597         /*
598          * The mmap_sem held all the way back in m_start() is what
599          * keeps khugepaged out of here and from collapsing things
600          * in here.
601          */
602         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
603         for (; addr != end; pte++, addr += PAGE_SIZE)
604                 smaps_pte_entry(pte, addr, walk);
605         pte_unmap_unlock(pte - 1, ptl);
606 out:
607         cond_resched();
608         return 0;
609 }
610 
611 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
612 {
613         /*
614          * Don't forget to update Documentation/ on changes.
615          */
616         static const char mnemonics[BITS_PER_LONG][2] = {
617                 /*
618                  * In case if we meet a flag we don't know about.
619                  */
620                 [0 ... (BITS_PER_LONG-1)] = "??",
621 
622                 [ilog2(VM_READ)]        = "rd",
623                 [ilog2(VM_WRITE)]       = "wr",
624                 [ilog2(VM_EXEC)]        = "ex",
625                 [ilog2(VM_SHARED)]      = "sh",
626                 [ilog2(VM_MAYREAD)]     = "mr",
627                 [ilog2(VM_MAYWRITE)]    = "mw",
628                 [ilog2(VM_MAYEXEC)]     = "me",
629                 [ilog2(VM_MAYSHARE)]    = "ms",
630                 [ilog2(VM_GROWSDOWN)]   = "gd",
631                 [ilog2(VM_PFNMAP)]      = "pf",
632                 [ilog2(VM_DENYWRITE)]   = "dw",
633 #ifdef CONFIG_X86_INTEL_MPX
634                 [ilog2(VM_MPX)]         = "mp",
635 #endif
636                 [ilog2(VM_LOCKED)]      = "lo",
637                 [ilog2(VM_IO)]          = "io",
638                 [ilog2(VM_SEQ_READ)]    = "sr",
639                 [ilog2(VM_RAND_READ)]   = "rr",
640                 [ilog2(VM_DONTCOPY)]    = "dc",
641                 [ilog2(VM_DONTEXPAND)]  = "de",
642                 [ilog2(VM_ACCOUNT)]     = "ac",
643                 [ilog2(VM_NORESERVE)]   = "nr",
644                 [ilog2(VM_HUGETLB)]     = "ht",
645                 [ilog2(VM_SYNC)]        = "sf",
646                 [ilog2(VM_ARCH_1)]      = "ar",
647                 [ilog2(VM_WIPEONFORK)]  = "wf",
648                 [ilog2(VM_DONTDUMP)]    = "dd",
649 #ifdef CONFIG_MEM_SOFT_DIRTY
650                 [ilog2(VM_SOFTDIRTY)]   = "sd",
651 #endif
652                 [ilog2(VM_MIXEDMAP)]    = "mm",
653                 [ilog2(VM_HUGEPAGE)]    = "hg",
654                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
655                 [ilog2(VM_MERGEABLE)]   = "mg",
656                 [ilog2(VM_UFFD_MISSING)]= "um",
657                 [ilog2(VM_UFFD_WP)]     = "uw",
658 #ifdef CONFIG_ARCH_HAS_PKEYS
659                 /* These come out via ProtectionKey: */
660                 [ilog2(VM_PKEY_BIT0)]   = "",
661                 [ilog2(VM_PKEY_BIT1)]   = "",
662                 [ilog2(VM_PKEY_BIT2)]   = "",
663                 [ilog2(VM_PKEY_BIT3)]   = "",
664 #if VM_PKEY_BIT4
665                 [ilog2(VM_PKEY_BIT4)]   = "",
666 #endif
667 #endif /* CONFIG_ARCH_HAS_PKEYS */
668         };
669         size_t i;
670 
671         seq_puts(m, "VmFlags: ");
672         for (i = 0; i < BITS_PER_LONG; i++) {
673                 if (!mnemonics[i][0])
674                         continue;
675                 if (vma->vm_flags & (1UL << i)) {
676                         seq_putc(m, mnemonics[i][0]);
677                         seq_putc(m, mnemonics[i][1]);
678                         seq_putc(m, ' ');
679                 }
680         }
681         seq_putc(m, '\n');
682 }
683 
684 #ifdef CONFIG_HUGETLB_PAGE
685 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
686                                  unsigned long addr, unsigned long end,
687                                  struct mm_walk *walk)
688 {
689         struct mem_size_stats *mss = walk->private;
690         struct vm_area_struct *vma = walk->vma;
691         struct page *page = NULL;
692 
693         if (pte_present(*pte)) {
694                 page = vm_normal_page(vma, addr, *pte);
695         } else if (is_swap_pte(*pte)) {
696                 swp_entry_t swpent = pte_to_swp_entry(*pte);
697 
698                 if (is_migration_entry(swpent))
699                         page = migration_entry_to_page(swpent);
700                 else if (is_device_private_entry(swpent))
701                         page = device_private_entry_to_page(swpent);
702         }
703         if (page) {
704                 int mapcount = page_mapcount(page);
705 
706                 if (mapcount >= 2)
707                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
708                 else
709                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
710         }
711         return 0;
712 }
713 #endif /* HUGETLB_PAGE */
714 
715 static void smap_gather_stats(struct vm_area_struct *vma,
716                              struct mem_size_stats *mss)
717 {
718         struct mm_walk smaps_walk = {
719                 .pmd_entry = smaps_pte_range,
720 #ifdef CONFIG_HUGETLB_PAGE
721                 .hugetlb_entry = smaps_hugetlb_range,
722 #endif
723                 .mm = vma->vm_mm,
724         };
725 
726         smaps_walk.private = mss;
727 
728 #ifdef CONFIG_SHMEM
729         /* In case of smaps_rollup, reset the value from previous vma */
730         mss->check_shmem_swap = false;
731         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
732                 /*
733                  * For shared or readonly shmem mappings we know that all
734                  * swapped out pages belong to the shmem object, and we can
735                  * obtain the swap value much more efficiently. For private
736                  * writable mappings, we might have COW pages that are
737                  * not affected by the parent swapped out pages of the shmem
738                  * object, so we have to distinguish them during the page walk.
739                  * Unless we know that the shmem object (or the part mapped by
740                  * our VMA) has no swapped out pages at all.
741                  */
742                 unsigned long shmem_swapped = shmem_swap_usage(vma);
743 
744                 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
745                                         !(vma->vm_flags & VM_WRITE)) {
746                         mss->swap += shmem_swapped;
747                 } else {
748                         mss->check_shmem_swap = true;
749                         smaps_walk.pte_hole = smaps_pte_hole;
750                 }
751         }
752 #endif
753         /* mmap_sem is held in m_start */
754         walk_page_vma(vma, &smaps_walk);
755 }
756 
757 #define SEQ_PUT_DEC(str, val) \
758                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
759 
760 /* Show the contents common for smaps and smaps_rollup */
761 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss)
762 {
763         SEQ_PUT_DEC("Rss:            ", mss->resident);
764         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
765         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
766         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
767         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
768         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
769         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
770         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
771         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
772         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
773         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
774         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
775         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
776                                   mss->private_hugetlb >> 10, 7);
777         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
778         SEQ_PUT_DEC(" kB\nSwapPss:        ",
779                                         mss->swap_pss >> PSS_SHIFT);
780         SEQ_PUT_DEC(" kB\nLocked:         ",
781                                         mss->pss_locked >> PSS_SHIFT);
782         seq_puts(m, " kB\n");
783 }
784 
785 static int show_smap(struct seq_file *m, void *v)
786 {
787         struct vm_area_struct *vma = v;
788         struct mem_size_stats mss;
789 
790         memset(&mss, 0, sizeof(mss));
791 
792         smap_gather_stats(vma, &mss);
793 
794         show_map_vma(m, vma);
795 
796         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
797         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
798         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
799         seq_puts(m, " kB\n");
800 
801         __show_smap(m, &mss);
802 
803         seq_printf(m, "THPeligible:    %d\n", transparent_hugepage_enabled(vma));
804 
805         if (arch_pkeys_enabled())
806                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
807         show_smap_vma_flags(m, vma);
808 
809         m_cache_vma(m, vma);
810 
811         return 0;
812 }
813 
814 static int show_smaps_rollup(struct seq_file *m, void *v)
815 {
816         struct proc_maps_private *priv = m->private;
817         struct mem_size_stats mss;
818         struct mm_struct *mm;
819         struct vm_area_struct *vma;
820         unsigned long last_vma_end = 0;
821         int ret = 0;
822 
823         priv->task = get_proc_task(priv->inode);
824         if (!priv->task)
825                 return -ESRCH;
826 
827         mm = priv->mm;
828         if (!mm || !mmget_not_zero(mm)) {
829                 ret = -ESRCH;
830                 goto out_put_task;
831         }
832 
833         memset(&mss, 0, sizeof(mss));
834 
835         ret = down_read_killable(&mm->mmap_sem);
836         if (ret)
837                 goto out_put_mm;
838 
839         hold_task_mempolicy(priv);
840 
841         for (vma = priv->mm->mmap; vma; vma = vma->vm_next) {
842                 smap_gather_stats(vma, &mss);
843                 last_vma_end = vma->vm_end;
844         }
845 
846         show_vma_header_prefix(m, priv->mm->mmap->vm_start,
847                                last_vma_end, 0, 0, 0, 0);
848         seq_pad(m, ' ');
849         seq_puts(m, "[rollup]\n");
850 
851         __show_smap(m, &mss);
852 
853         release_task_mempolicy(priv);
854         up_read(&mm->mmap_sem);
855 
856 out_put_mm:
857         mmput(mm);
858 out_put_task:
859         put_task_struct(priv->task);
860         priv->task = NULL;
861 
862         return ret;
863 }
864 #undef SEQ_PUT_DEC
865 
866 static const struct seq_operations proc_pid_smaps_op = {
867         .start  = m_start,
868         .next   = m_next,
869         .stop   = m_stop,
870         .show   = show_smap
871 };
872 
873 static int pid_smaps_open(struct inode *inode, struct file *file)
874 {
875         return do_maps_open(inode, file, &proc_pid_smaps_op);
876 }
877 
878 static int smaps_rollup_open(struct inode *inode, struct file *file)
879 {
880         int ret;
881         struct proc_maps_private *priv;
882 
883         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
884         if (!priv)
885                 return -ENOMEM;
886 
887         ret = single_open(file, show_smaps_rollup, priv);
888         if (ret)
889                 goto out_free;
890 
891         priv->inode = inode;
892         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
893         if (IS_ERR(priv->mm)) {
894                 ret = PTR_ERR(priv->mm);
895 
896                 single_release(inode, file);
897                 goto out_free;
898         }
899 
900         return 0;
901 
902 out_free:
903         kfree(priv);
904         return ret;
905 }
906 
907 static int smaps_rollup_release(struct inode *inode, struct file *file)
908 {
909         struct seq_file *seq = file->private_data;
910         struct proc_maps_private *priv = seq->private;
911 
912         if (priv->mm)
913                 mmdrop(priv->mm);
914 
915         kfree(priv);
916         return single_release(inode, file);
917 }
918 
919 const struct file_operations proc_pid_smaps_operations = {
920         .open           = pid_smaps_open,
921         .read           = seq_read,
922         .llseek         = seq_lseek,
923         .release        = proc_map_release,
924 };
925 
926 const struct file_operations proc_pid_smaps_rollup_operations = {
927         .open           = smaps_rollup_open,
928         .read           = seq_read,
929         .llseek         = seq_lseek,
930         .release        = smaps_rollup_release,
931 };
932 
933 enum clear_refs_types {
934         CLEAR_REFS_ALL = 1,
935         CLEAR_REFS_ANON,
936         CLEAR_REFS_MAPPED,
937         CLEAR_REFS_SOFT_DIRTY,
938         CLEAR_REFS_MM_HIWATER_RSS,
939         CLEAR_REFS_LAST,
940 };
941 
942 struct clear_refs_private {
943         enum clear_refs_types type;
944 };
945 
946 #ifdef CONFIG_MEM_SOFT_DIRTY
947 static inline void clear_soft_dirty(struct vm_area_struct *vma,
948                 unsigned long addr, pte_t *pte)
949 {
950         /*
951          * The soft-dirty tracker uses #PF-s to catch writes
952          * to pages, so write-protect the pte as well. See the
953          * Documentation/admin-guide/mm/soft-dirty.rst for full description
954          * of how soft-dirty works.
955          */
956         pte_t ptent = *pte;
957 
958         if (pte_present(ptent)) {
959                 pte_t old_pte;
960 
961                 old_pte = ptep_modify_prot_start(vma, addr, pte);
962                 ptent = pte_wrprotect(old_pte);
963                 ptent = pte_clear_soft_dirty(ptent);
964                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
965         } else if (is_swap_pte(ptent)) {
966                 ptent = pte_swp_clear_soft_dirty(ptent);
967                 set_pte_at(vma->vm_mm, addr, pte, ptent);
968         }
969 }
970 #else
971 static inline void clear_soft_dirty(struct vm_area_struct *vma,
972                 unsigned long addr, pte_t *pte)
973 {
974 }
975 #endif
976 
977 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
978 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
979                 unsigned long addr, pmd_t *pmdp)
980 {
981         pmd_t old, pmd = *pmdp;
982 
983         if (pmd_present(pmd)) {
984                 /* See comment in change_huge_pmd() */
985                 old = pmdp_invalidate(vma, addr, pmdp);
986                 if (pmd_dirty(old))
987                         pmd = pmd_mkdirty(pmd);
988                 if (pmd_young(old))
989                         pmd = pmd_mkyoung(pmd);
990 
991                 pmd = pmd_wrprotect(pmd);
992                 pmd = pmd_clear_soft_dirty(pmd);
993 
994                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
995         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
996                 pmd = pmd_swp_clear_soft_dirty(pmd);
997                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
998         }
999 }
1000 #else
1001 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1002                 unsigned long addr, pmd_t *pmdp)
1003 {
1004 }
1005 #endif
1006 
1007 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1008                                 unsigned long end, struct mm_walk *walk)
1009 {
1010         struct clear_refs_private *cp = walk->private;
1011         struct vm_area_struct *vma = walk->vma;
1012         pte_t *pte, ptent;
1013         spinlock_t *ptl;
1014         struct page *page;
1015 
1016         ptl = pmd_trans_huge_lock(pmd, vma);
1017         if (ptl) {
1018                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1019                         clear_soft_dirty_pmd(vma, addr, pmd);
1020                         goto out;
1021                 }
1022 
1023                 if (!pmd_present(*pmd))
1024                         goto out;
1025 
1026                 page = pmd_page(*pmd);
1027 
1028                 /* Clear accessed and referenced bits. */
1029                 pmdp_test_and_clear_young(vma, addr, pmd);
1030                 test_and_clear_page_young(page);
1031                 ClearPageReferenced(page);
1032 out:
1033                 spin_unlock(ptl);
1034                 return 0;
1035         }
1036 
1037         if (pmd_trans_unstable(pmd))
1038                 return 0;
1039 
1040         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1041         for (; addr != end; pte++, addr += PAGE_SIZE) {
1042                 ptent = *pte;
1043 
1044                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1045                         clear_soft_dirty(vma, addr, pte);
1046                         continue;
1047                 }
1048 
1049                 if (!pte_present(ptent))
1050                         continue;
1051 
1052                 page = vm_normal_page(vma, addr, ptent);
1053                 if (!page)
1054                         continue;
1055 
1056                 /* Clear accessed and referenced bits. */
1057                 ptep_test_and_clear_young(vma, addr, pte);
1058                 test_and_clear_page_young(page);
1059                 ClearPageReferenced(page);
1060         }
1061         pte_unmap_unlock(pte - 1, ptl);
1062         cond_resched();
1063         return 0;
1064 }
1065 
1066 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1067                                 struct mm_walk *walk)
1068 {
1069         struct clear_refs_private *cp = walk->private;
1070         struct vm_area_struct *vma = walk->vma;
1071 
1072         if (vma->vm_flags & VM_PFNMAP)
1073                 return 1;
1074 
1075         /*
1076          * Writing 1 to /proc/pid/clear_refs affects all pages.
1077          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1078          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1079          * Writing 4 to /proc/pid/clear_refs affects all pages.
1080          */
1081         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1082                 return 1;
1083         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1084                 return 1;
1085         return 0;
1086 }
1087 
1088 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1089                                 size_t count, loff_t *ppos)
1090 {
1091         struct task_struct *task;
1092         char buffer[PROC_NUMBUF];
1093         struct mm_struct *mm;
1094         struct vm_area_struct *vma;
1095         enum clear_refs_types type;
1096         struct mmu_gather tlb;
1097         int itype;
1098         int rv;
1099 
1100         memset(buffer, 0, sizeof(buffer));
1101         if (count > sizeof(buffer) - 1)
1102                 count = sizeof(buffer) - 1;
1103         if (copy_from_user(buffer, buf, count))
1104                 return -EFAULT;
1105         rv = kstrtoint(strstrip(buffer), 10, &itype);
1106         if (rv < 0)
1107                 return rv;
1108         type = (enum clear_refs_types)itype;
1109         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1110                 return -EINVAL;
1111 
1112         task = get_proc_task(file_inode(file));
1113         if (!task)
1114                 return -ESRCH;
1115         mm = get_task_mm(task);
1116         if (mm) {
1117                 struct mmu_notifier_range range;
1118                 struct clear_refs_private cp = {
1119                         .type = type,
1120                 };
1121                 struct mm_walk clear_refs_walk = {
1122                         .pmd_entry = clear_refs_pte_range,
1123                         .test_walk = clear_refs_test_walk,
1124                         .mm = mm,
1125                         .private = &cp,
1126                 };
1127 
1128                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1129                         if (down_write_killable(&mm->mmap_sem)) {
1130                                 count = -EINTR;
1131                                 goto out_mm;
1132                         }
1133 
1134                         /*
1135                          * Writing 5 to /proc/pid/clear_refs resets the peak
1136                          * resident set size to this mm's current rss value.
1137                          */
1138                         reset_mm_hiwater_rss(mm);
1139                         up_write(&mm->mmap_sem);
1140                         goto out_mm;
1141                 }
1142 
1143                 if (down_read_killable(&mm->mmap_sem)) {
1144                         count = -EINTR;
1145                         goto out_mm;
1146                 }
1147                 tlb_gather_mmu(&tlb, mm, 0, -1);
1148                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1149                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1150                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1151                                         continue;
1152                                 up_read(&mm->mmap_sem);
1153                                 if (down_write_killable(&mm->mmap_sem)) {
1154                                         count = -EINTR;
1155                                         goto out_mm;
1156                                 }
1157                                 /*
1158                                  * Avoid to modify vma->vm_flags
1159                                  * without locked ops while the
1160                                  * coredump reads the vm_flags.
1161                                  */
1162                                 if (!mmget_still_valid(mm)) {
1163                                         /*
1164                                          * Silently return "count"
1165                                          * like if get_task_mm()
1166                                          * failed. FIXME: should this
1167                                          * function have returned
1168                                          * -ESRCH if get_task_mm()
1169                                          * failed like if
1170                                          * get_proc_task() fails?
1171                                          */
1172                                         up_write(&mm->mmap_sem);
1173                                         goto out_mm;
1174                                 }
1175                                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1176                                         vma->vm_flags &= ~VM_SOFTDIRTY;
1177                                         vma_set_page_prot(vma);
1178                                 }
1179                                 downgrade_write(&mm->mmap_sem);
1180                                 break;
1181                         }
1182 
1183                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1184                                                 0, NULL, mm, 0, -1UL);
1185                         mmu_notifier_invalidate_range_start(&range);
1186                 }
1187                 walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1188                 if (type == CLEAR_REFS_SOFT_DIRTY)
1189                         mmu_notifier_invalidate_range_end(&range);
1190                 tlb_finish_mmu(&tlb, 0, -1);
1191                 up_read(&mm->mmap_sem);
1192 out_mm:
1193                 mmput(mm);
1194         }
1195         put_task_struct(task);
1196 
1197         return count;
1198 }
1199 
1200 const struct file_operations proc_clear_refs_operations = {
1201         .write          = clear_refs_write,
1202         .llseek         = noop_llseek,
1203 };
1204 
1205 typedef struct {
1206         u64 pme;
1207 } pagemap_entry_t;
1208 
1209 struct pagemapread {
1210         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1211         pagemap_entry_t *buffer;
1212         bool show_pfn;
1213 };
1214 
1215 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1216 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1217 
1218 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1219 #define PM_PFRAME_BITS          55
1220 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1221 #define PM_SOFT_DIRTY           BIT_ULL(55)
1222 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1223 #define PM_FILE                 BIT_ULL(61)
1224 #define PM_SWAP                 BIT_ULL(62)
1225 #define PM_PRESENT              BIT_ULL(63)
1226 
1227 #define PM_END_OF_BUFFER    1
1228 
1229 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1230 {
1231         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1232 }
1233 
1234 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1235                           struct pagemapread *pm)
1236 {
1237         pm->buffer[pm->pos++] = *pme;
1238         if (pm->pos >= pm->len)
1239                 return PM_END_OF_BUFFER;
1240         return 0;
1241 }
1242 
1243 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1244                                 struct mm_walk *walk)
1245 {
1246         struct pagemapread *pm = walk->private;
1247         unsigned long addr = start;
1248         int err = 0;
1249 
1250         while (addr < end) {
1251                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1252                 pagemap_entry_t pme = make_pme(0, 0);
1253                 /* End of address space hole, which we mark as non-present. */
1254                 unsigned long hole_end;
1255 
1256                 if (vma)
1257                         hole_end = min(end, vma->vm_start);
1258                 else
1259                         hole_end = end;
1260 
1261                 for (; addr < hole_end; addr += PAGE_SIZE) {
1262                         err = add_to_pagemap(addr, &pme, pm);
1263                         if (err)
1264                                 goto out;
1265                 }
1266 
1267                 if (!vma)
1268                         break;
1269 
1270                 /* Addresses in the VMA. */
1271                 if (vma->vm_flags & VM_SOFTDIRTY)
1272                         pme = make_pme(0, PM_SOFT_DIRTY);
1273                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1274                         err = add_to_pagemap(addr, &pme, pm);
1275                         if (err)
1276                                 goto out;
1277                 }
1278         }
1279 out:
1280         return err;
1281 }
1282 
1283 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1284                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1285 {
1286         u64 frame = 0, flags = 0;
1287         struct page *page = NULL;
1288 
1289         if (pte_present(pte)) {
1290                 if (pm->show_pfn)
1291                         frame = pte_pfn(pte);
1292                 flags |= PM_PRESENT;
1293                 page = _vm_normal_page(vma, addr, pte, true);
1294                 if (pte_soft_dirty(pte))
1295                         flags |= PM_SOFT_DIRTY;
1296         } else if (is_swap_pte(pte)) {
1297                 swp_entry_t entry;
1298                 if (pte_swp_soft_dirty(pte))
1299                         flags |= PM_SOFT_DIRTY;
1300                 entry = pte_to_swp_entry(pte);
1301                 if (pm->show_pfn)
1302                         frame = swp_type(entry) |
1303                                 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1304                 flags |= PM_SWAP;
1305                 if (is_migration_entry(entry))
1306                         page = migration_entry_to_page(entry);
1307 
1308                 if (is_device_private_entry(entry))
1309                         page = device_private_entry_to_page(entry);
1310         }
1311 
1312         if (page && !PageAnon(page))
1313                 flags |= PM_FILE;
1314         if (page && page_mapcount(page) == 1)
1315                 flags |= PM_MMAP_EXCLUSIVE;
1316         if (vma->vm_flags & VM_SOFTDIRTY)
1317                 flags |= PM_SOFT_DIRTY;
1318 
1319         return make_pme(frame, flags);
1320 }
1321 
1322 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1323                              struct mm_walk *walk)
1324 {
1325         struct vm_area_struct *vma = walk->vma;
1326         struct pagemapread *pm = walk->private;
1327         spinlock_t *ptl;
1328         pte_t *pte, *orig_pte;
1329         int err = 0;
1330 
1331 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1332         ptl = pmd_trans_huge_lock(pmdp, vma);
1333         if (ptl) {
1334                 u64 flags = 0, frame = 0;
1335                 pmd_t pmd = *pmdp;
1336                 struct page *page = NULL;
1337 
1338                 if (vma->vm_flags & VM_SOFTDIRTY)
1339                         flags |= PM_SOFT_DIRTY;
1340 
1341                 if (pmd_present(pmd)) {
1342                         page = pmd_page(pmd);
1343 
1344                         flags |= PM_PRESENT;
1345                         if (pmd_soft_dirty(pmd))
1346                                 flags |= PM_SOFT_DIRTY;
1347                         if (pm->show_pfn)
1348                                 frame = pmd_pfn(pmd) +
1349                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1350                 }
1351 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1352                 else if (is_swap_pmd(pmd)) {
1353                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1354                         unsigned long offset;
1355 
1356                         if (pm->show_pfn) {
1357                                 offset = swp_offset(entry) +
1358                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1359                                 frame = swp_type(entry) |
1360                                         (offset << MAX_SWAPFILES_SHIFT);
1361                         }
1362                         flags |= PM_SWAP;
1363                         if (pmd_swp_soft_dirty(pmd))
1364                                 flags |= PM_SOFT_DIRTY;
1365                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1366                         page = migration_entry_to_page(entry);
1367                 }
1368 #endif
1369 
1370                 if (page && page_mapcount(page) == 1)
1371                         flags |= PM_MMAP_EXCLUSIVE;
1372 
1373                 for (; addr != end; addr += PAGE_SIZE) {
1374                         pagemap_entry_t pme = make_pme(frame, flags);
1375 
1376                         err = add_to_pagemap(addr, &pme, pm);
1377                         if (err)
1378                                 break;
1379                         if (pm->show_pfn) {
1380                                 if (flags & PM_PRESENT)
1381                                         frame++;
1382                                 else if (flags & PM_SWAP)
1383                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1384                         }
1385                 }
1386                 spin_unlock(ptl);
1387                 return err;
1388         }
1389 
1390         if (pmd_trans_unstable(pmdp))
1391                 return 0;
1392 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1393 
1394         /*
1395          * We can assume that @vma always points to a valid one and @end never
1396          * goes beyond vma->vm_end.
1397          */
1398         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1399         for (; addr < end; pte++, addr += PAGE_SIZE) {
1400                 pagemap_entry_t pme;
1401 
1402                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1403                 err = add_to_pagemap(addr, &pme, pm);
1404                 if (err)
1405                         break;
1406         }
1407         pte_unmap_unlock(orig_pte, ptl);
1408 
1409         cond_resched();
1410 
1411         return err;
1412 }
1413 
1414 #ifdef CONFIG_HUGETLB_PAGE
1415 /* This function walks within one hugetlb entry in the single call */
1416 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1417                                  unsigned long addr, unsigned long end,
1418                                  struct mm_walk *walk)
1419 {
1420         struct pagemapread *pm = walk->private;
1421         struct vm_area_struct *vma = walk->vma;
1422         u64 flags = 0, frame = 0;
1423         int err = 0;
1424         pte_t pte;
1425 
1426         if (vma->vm_flags & VM_SOFTDIRTY)
1427                 flags |= PM_SOFT_DIRTY;
1428 
1429         pte = huge_ptep_get(ptep);
1430         if (pte_present(pte)) {
1431                 struct page *page = pte_page(pte);
1432 
1433                 if (!PageAnon(page))
1434                         flags |= PM_FILE;
1435 
1436                 if (page_mapcount(page) == 1)
1437                         flags |= PM_MMAP_EXCLUSIVE;
1438 
1439                 flags |= PM_PRESENT;
1440                 if (pm->show_pfn)
1441                         frame = pte_pfn(pte) +
1442                                 ((addr & ~hmask) >> PAGE_SHIFT);
1443         }
1444 
1445         for (; addr != end; addr += PAGE_SIZE) {
1446                 pagemap_entry_t pme = make_pme(frame, flags);
1447 
1448                 err = add_to_pagemap(addr, &pme, pm);
1449                 if (err)
1450                         return err;
1451                 if (pm->show_pfn && (flags & PM_PRESENT))
1452                         frame++;
1453         }
1454 
1455         cond_resched();
1456 
1457         return err;
1458 }
1459 #endif /* HUGETLB_PAGE */
1460 
1461 /*
1462  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1463  *
1464  * For each page in the address space, this file contains one 64-bit entry
1465  * consisting of the following:
1466  *
1467  * Bits 0-54  page frame number (PFN) if present
1468  * Bits 0-4   swap type if swapped
1469  * Bits 5-54  swap offset if swapped
1470  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1471  * Bit  56    page exclusively mapped
1472  * Bits 57-60 zero
1473  * Bit  61    page is file-page or shared-anon
1474  * Bit  62    page swapped
1475  * Bit  63    page present
1476  *
1477  * If the page is not present but in swap, then the PFN contains an
1478  * encoding of the swap file number and the page's offset into the
1479  * swap. Unmapped pages return a null PFN. This allows determining
1480  * precisely which pages are mapped (or in swap) and comparing mapped
1481  * pages between processes.
1482  *
1483  * Efficient users of this interface will use /proc/pid/maps to
1484  * determine which areas of memory are actually mapped and llseek to
1485  * skip over unmapped regions.
1486  */
1487 static ssize_t pagemap_read(struct file *file, char __user *buf,
1488                             size_t count, loff_t *ppos)
1489 {
1490         struct mm_struct *mm = file->private_data;
1491         struct pagemapread pm;
1492         struct mm_walk pagemap_walk = {};
1493         unsigned long src;
1494         unsigned long svpfn;
1495         unsigned long start_vaddr;
1496         unsigned long end_vaddr;
1497         int ret = 0, copied = 0;
1498 
1499         if (!mm || !mmget_not_zero(mm))
1500                 goto out;
1501 
1502         ret = -EINVAL;
1503         /* file position must be aligned */
1504         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1505                 goto out_mm;
1506 
1507         ret = 0;
1508         if (!count)
1509                 goto out_mm;
1510 
1511         /* do not disclose physical addresses: attack vector */
1512         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1513 
1514         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1515         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1516         ret = -ENOMEM;
1517         if (!pm.buffer)
1518                 goto out_mm;
1519 
1520         pagemap_walk.pmd_entry = pagemap_pmd_range;
1521         pagemap_walk.pte_hole = pagemap_pte_hole;
1522 #ifdef CONFIG_HUGETLB_PAGE
1523         pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1524 #endif
1525         pagemap_walk.mm = mm;
1526         pagemap_walk.private = &pm;
1527 
1528         src = *ppos;
1529         svpfn = src / PM_ENTRY_BYTES;
1530         start_vaddr = svpfn << PAGE_SHIFT;
1531         end_vaddr = mm->task_size;
1532 
1533         /* watch out for wraparound */
1534         if (svpfn > mm->task_size >> PAGE_SHIFT)
1535                 start_vaddr = end_vaddr;
1536 
1537         /*
1538          * The odds are that this will stop walking way
1539          * before end_vaddr, because the length of the
1540          * user buffer is tracked in "pm", and the walk
1541          * will stop when we hit the end of the buffer.
1542          */
1543         ret = 0;
1544         while (count && (start_vaddr < end_vaddr)) {
1545                 int len;
1546                 unsigned long end;
1547 
1548                 pm.pos = 0;
1549                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1550                 /* overflow ? */
1551                 if (end < start_vaddr || end > end_vaddr)
1552                         end = end_vaddr;
1553                 ret = down_read_killable(&mm->mmap_sem);
1554                 if (ret)
1555                         goto out_free;
1556                 ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1557                 up_read(&mm->mmap_sem);
1558                 start_vaddr = end;
1559 
1560                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1561                 if (copy_to_user(buf, pm.buffer, len)) {
1562                         ret = -EFAULT;
1563                         goto out_free;
1564                 }
1565                 copied += len;
1566                 buf += len;
1567                 count -= len;
1568         }
1569         *ppos += copied;
1570         if (!ret || ret == PM_END_OF_BUFFER)
1571                 ret = copied;
1572 
1573 out_free:
1574         kfree(pm.buffer);
1575 out_mm:
1576         mmput(mm);
1577 out:
1578         return ret;
1579 }
1580 
1581 static int pagemap_open(struct inode *inode, struct file *file)
1582 {
1583         struct mm_struct *mm;
1584 
1585         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1586         if (IS_ERR(mm))
1587                 return PTR_ERR(mm);
1588         file->private_data = mm;
1589         return 0;
1590 }
1591 
1592 static int pagemap_release(struct inode *inode, struct file *file)
1593 {
1594         struct mm_struct *mm = file->private_data;
1595 
1596         if (mm)
1597                 mmdrop(mm);
1598         return 0;
1599 }
1600 
1601 const struct file_operations proc_pagemap_operations = {
1602         .llseek         = mem_lseek, /* borrow this */
1603         .read           = pagemap_read,
1604         .open           = pagemap_open,
1605         .release        = pagemap_release,
1606 };
1607 #endif /* CONFIG_PROC_PAGE_MONITOR */
1608 
1609 #ifdef CONFIG_NUMA
1610 
1611 struct numa_maps {
1612         unsigned long pages;
1613         unsigned long anon;
1614         unsigned long active;
1615         unsigned long writeback;
1616         unsigned long mapcount_max;
1617         unsigned long dirty;
1618         unsigned long swapcache;
1619         unsigned long node[MAX_NUMNODES];
1620 };
1621 
1622 struct numa_maps_private {
1623         struct proc_maps_private proc_maps;
1624         struct numa_maps md;
1625 };
1626 
1627 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1628                         unsigned long nr_pages)
1629 {
1630         int count = page_mapcount(page);
1631 
1632         md->pages += nr_pages;
1633         if (pte_dirty || PageDirty(page))
1634                 md->dirty += nr_pages;
1635 
1636         if (PageSwapCache(page))
1637                 md->swapcache += nr_pages;
1638 
1639         if (PageActive(page) || PageUnevictable(page))
1640                 md->active += nr_pages;
1641 
1642         if (PageWriteback(page))
1643                 md->writeback += nr_pages;
1644 
1645         if (PageAnon(page))
1646                 md->anon += nr_pages;
1647 
1648         if (count > md->mapcount_max)
1649                 md->mapcount_max = count;
1650 
1651         md->node[page_to_nid(page)] += nr_pages;
1652 }
1653 
1654 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1655                 unsigned long addr)
1656 {
1657         struct page *page;
1658         int nid;
1659 
1660         if (!pte_present(pte))
1661                 return NULL;
1662 
1663         page = vm_normal_page(vma, addr, pte);
1664         if (!page)
1665                 return NULL;
1666 
1667         if (PageReserved(page))
1668                 return NULL;
1669 
1670         nid = page_to_nid(page);
1671         if (!node_isset(nid, node_states[N_MEMORY]))
1672                 return NULL;
1673 
1674         return page;
1675 }
1676 
1677 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1678 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1679                                               struct vm_area_struct *vma,
1680                                               unsigned long addr)
1681 {
1682         struct page *page;
1683         int nid;
1684 
1685         if (!pmd_present(pmd))
1686                 return NULL;
1687 
1688         page = vm_normal_page_pmd(vma, addr, pmd);
1689         if (!page)
1690                 return NULL;
1691 
1692         if (PageReserved(page))
1693                 return NULL;
1694 
1695         nid = page_to_nid(page);
1696         if (!node_isset(nid, node_states[N_MEMORY]))
1697                 return NULL;
1698 
1699         return page;
1700 }
1701 #endif
1702 
1703 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1704                 unsigned long end, struct mm_walk *walk)
1705 {
1706         struct numa_maps *md = walk->private;
1707         struct vm_area_struct *vma = walk->vma;
1708         spinlock_t *ptl;
1709         pte_t *orig_pte;
1710         pte_t *pte;
1711 
1712 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1713         ptl = pmd_trans_huge_lock(pmd, vma);
1714         if (ptl) {
1715                 struct page *page;
1716 
1717                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1718                 if (page)
1719                         gather_stats(page, md, pmd_dirty(*pmd),
1720                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1721                 spin_unlock(ptl);
1722                 return 0;
1723         }
1724 
1725         if (pmd_trans_unstable(pmd))
1726                 return 0;
1727 #endif
1728         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1729         do {
1730                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1731                 if (!page)
1732                         continue;
1733                 gather_stats(page, md, pte_dirty(*pte), 1);
1734 
1735         } while (pte++, addr += PAGE_SIZE, addr != end);
1736         pte_unmap_unlock(orig_pte, ptl);
1737         cond_resched();
1738         return 0;
1739 }
1740 #ifdef CONFIG_HUGETLB_PAGE
1741 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1742                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1743 {
1744         pte_t huge_pte = huge_ptep_get(pte);
1745         struct numa_maps *md;
1746         struct page *page;
1747 
1748         if (!pte_present(huge_pte))
1749                 return 0;
1750 
1751         page = pte_page(huge_pte);
1752         if (!page)
1753                 return 0;
1754 
1755         md = walk->private;
1756         gather_stats(page, md, pte_dirty(huge_pte), 1);
1757         return 0;
1758 }
1759 
1760 #else
1761 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1762                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1763 {
1764         return 0;
1765 }
1766 #endif
1767 
1768 /*
1769  * Display pages allocated per node and memory policy via /proc.
1770  */
1771 static int show_numa_map(struct seq_file *m, void *v)
1772 {
1773         struct numa_maps_private *numa_priv = m->private;
1774         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1775         struct vm_area_struct *vma = v;
1776         struct numa_maps *md = &numa_priv->md;
1777         struct file *file = vma->vm_file;
1778         struct mm_struct *mm = vma->vm_mm;
1779         struct mm_walk walk = {
1780                 .hugetlb_entry = gather_hugetlb_stats,
1781                 .pmd_entry = gather_pte_stats,
1782                 .private = md,
1783                 .mm = mm,
1784         };
1785         struct mempolicy *pol;
1786         char buffer[64];
1787         int nid;
1788 
1789         if (!mm)
1790                 return 0;
1791 
1792         /* Ensure we start with an empty set of numa_maps statistics. */
1793         memset(md, 0, sizeof(*md));
1794 
1795         pol = __get_vma_policy(vma, vma->vm_start);
1796         if (pol) {
1797                 mpol_to_str(buffer, sizeof(buffer), pol);
1798                 mpol_cond_put(pol);
1799         } else {
1800                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1801         }
1802 
1803         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1804 
1805         if (file) {
1806                 seq_puts(m, " file=");
1807                 seq_file_path(m, file, "\n\t= ");
1808         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1809                 seq_puts(m, " heap");
1810         } else if (is_stack(vma)) {
1811                 seq_puts(m, " stack");
1812         }
1813 
1814         if (is_vm_hugetlb_page(vma))
1815                 seq_puts(m, " huge");
1816 
1817         /* mmap_sem is held by m_start */
1818         walk_page_vma(vma, &walk);
1819 
1820         if (!md->pages)
1821                 goto out;
1822 
1823         if (md->anon)
1824                 seq_printf(m, " anon=%lu", md->anon);
1825 
1826         if (md->dirty)
1827                 seq_printf(m, " dirty=%lu", md->dirty);
1828 
1829         if (md->pages != md->anon && md->pages != md->dirty)
1830                 seq_printf(m, " mapped=%lu", md->pages);
1831 
1832         if (md->mapcount_max > 1)
1833                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1834 
1835         if (md->swapcache)
1836                 seq_printf(m, " swapcache=%lu", md->swapcache);
1837 
1838         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1839                 seq_printf(m, " active=%lu", md->active);
1840 
1841         if (md->writeback)
1842                 seq_printf(m, " writeback=%lu", md->writeback);
1843 
1844         for_each_node_state(nid, N_MEMORY)
1845                 if (md->node[nid])
1846                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1847 
1848         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1849 out:
1850         seq_putc(m, '\n');
1851         m_cache_vma(m, vma);
1852         return 0;
1853 }
1854 
1855 static const struct seq_operations proc_pid_numa_maps_op = {
1856         .start  = m_start,
1857         .next   = m_next,
1858         .stop   = m_stop,
1859         .show   = show_numa_map,
1860 };
1861 
1862 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1863 {
1864         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1865                                 sizeof(struct numa_maps_private));
1866 }
1867 
1868 const struct file_operations proc_pid_numa_maps_operations = {
1869         .open           = pid_numa_maps_open,
1870         .read           = seq_read,
1871         .llseek         = seq_lseek,
1872         .release        = proc_map_release,
1873 };
1874 
1875 #endif /* CONFIG_NUMA */
1876 

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