LCOV - code coverage report
Current view: top level - fs/proc - task_mmu.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 0 527 0.0 %
Date: 2023-07-19 18:55:55 Functions: 0 34 0.0 %

          Line data    Source code
       1             : // SPDX-License-Identifier: GPL-2.0
       2             : #include <linux/pagewalk.h>
       3             : #include <linux/mm_inline.h>
       4             : #include <linux/hugetlb.h>
       5             : #include <linux/huge_mm.h>
       6             : #include <linux/mount.h>
       7             : #include <linux/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           0 : 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           0 :         anon = get_mm_counter(mm, MM_ANONPAGES);
      36           0 :         file = get_mm_counter(mm, MM_FILEPAGES);
      37           0 :         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           0 :         hiwater_vm = total_vm = mm->total_vm;
      47           0 :         if (hiwater_vm < mm->hiwater_vm)
      48           0 :                 hiwater_vm = mm->hiwater_vm;
      49           0 :         hiwater_rss = total_rss = anon + file + shmem;
      50           0 :         if (hiwater_rss < mm->hiwater_rss)
      51           0 :                 hiwater_rss = mm->hiwater_rss;
      52             : 
      53             :         /* split executable areas between text and lib */
      54           0 :         text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
      55           0 :         text = min(text, mm->exec_vm << PAGE_SHIFT);
      56           0 :         lib = (mm->exec_vm << PAGE_SHIFT) - text;
      57             : 
      58           0 :         swap = get_mm_counter(mm, MM_SWAPENTS);
      59           0 :         SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
      60           0 :         SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
      61           0 :         SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
      62           0 :         SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
      63           0 :         SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
      64           0 :         SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
      65           0 :         SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
      66           0 :         SEQ_PUT_DEC(" kB\nRssFile:\t", file);
      67           0 :         SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
      68           0 :         SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
      69           0 :         SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
      70           0 :         seq_put_decimal_ull_width(m,
      71           0 :                     " kB\nVmExe:\t", text >> 10, 8);
      72           0 :         seq_put_decimal_ull_width(m,
      73           0 :                     " kB\nVmLib:\t", lib >> 10, 8);
      74           0 :         seq_put_decimal_ull_width(m,
      75           0 :                     " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
      76           0 :         SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
      77           0 :         seq_puts(m, " kB\n");
      78           0 :         hugetlb_report_usage(m, mm);
      79           0 : }
      80             : #undef SEQ_PUT_DEC
      81             : 
      82           0 : unsigned long task_vsize(struct mm_struct *mm)
      83             : {
      84           0 :         return PAGE_SIZE * mm->total_vm;
      85             : }
      86             : 
      87           0 : unsigned long task_statm(struct mm_struct *mm,
      88             :                          unsigned long *shared, unsigned long *text,
      89             :                          unsigned long *data, unsigned long *resident)
      90             : {
      91           0 :         *shared = get_mm_counter(mm, MM_FILEPAGES) +
      92           0 :                         get_mm_counter(mm, MM_SHMEMPAGES);
      93           0 :         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
      94           0 :                                                                 >> PAGE_SHIFT;
      95           0 :         *data = mm->data_vm + mm->stack_vm;
      96           0 :         *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
      97           0 :         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 struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
     127             :                                                 loff_t *ppos)
     128             : {
     129           0 :         struct vm_area_struct *vma = vma_next(&priv->iter);
     130             : 
     131           0 :         if (vma) {
     132           0 :                 *ppos = vma->vm_start;
     133             :         } else {
     134           0 :                 *ppos = -2UL;
     135           0 :                 vma = get_gate_vma(priv->mm);
     136             :         }
     137             : 
     138             :         return vma;
     139             : }
     140             : 
     141           0 : static void *m_start(struct seq_file *m, loff_t *ppos)
     142             : {
     143           0 :         struct proc_maps_private *priv = m->private;
     144           0 :         unsigned long last_addr = *ppos;
     145             :         struct mm_struct *mm;
     146             : 
     147             :         /* See m_next(). Zero at the start or after lseek. */
     148           0 :         if (last_addr == -1UL)
     149             :                 return NULL;
     150             : 
     151           0 :         priv->task = get_proc_task(priv->inode);
     152           0 :         if (!priv->task)
     153             :                 return ERR_PTR(-ESRCH);
     154             : 
     155           0 :         mm = priv->mm;
     156           0 :         if (!mm || !mmget_not_zero(mm)) {
     157           0 :                 put_task_struct(priv->task);
     158           0 :                 priv->task = NULL;
     159           0 :                 return NULL;
     160             :         }
     161             : 
     162           0 :         if (mmap_read_lock_killable(mm)) {
     163           0 :                 mmput(mm);
     164           0 :                 put_task_struct(priv->task);
     165           0 :                 priv->task = NULL;
     166           0 :                 return ERR_PTR(-EINTR);
     167             :         }
     168             : 
     169           0 :         vma_iter_init(&priv->iter, mm, last_addr);
     170           0 :         hold_task_mempolicy(priv);
     171           0 :         if (last_addr == -2UL)
     172             :                 return get_gate_vma(mm);
     173             : 
     174             :         return proc_get_vma(priv, ppos);
     175             : }
     176             : 
     177           0 : static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
     178             : {
     179           0 :         if (*ppos == -2UL) {
     180           0 :                 *ppos = -1UL;
     181           0 :                 return NULL;
     182             :         }
     183           0 :         return proc_get_vma(m->private, ppos);
     184             : }
     185             : 
     186           0 : static void m_stop(struct seq_file *m, void *v)
     187             : {
     188           0 :         struct proc_maps_private *priv = m->private;
     189           0 :         struct mm_struct *mm = priv->mm;
     190             : 
     191           0 :         if (!priv->task)
     192             :                 return;
     193             : 
     194           0 :         release_task_mempolicy(priv);
     195           0 :         mmap_read_unlock(mm);
     196           0 :         mmput(mm);
     197           0 :         put_task_struct(priv->task);
     198           0 :         priv->task = NULL;
     199             : }
     200             : 
     201           0 : static int proc_maps_open(struct inode *inode, struct file *file,
     202             :                         const struct seq_operations *ops, int psize)
     203             : {
     204           0 :         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
     205             : 
     206           0 :         if (!priv)
     207             :                 return -ENOMEM;
     208             : 
     209           0 :         priv->inode = inode;
     210           0 :         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
     211           0 :         if (IS_ERR(priv->mm)) {
     212           0 :                 int err = PTR_ERR(priv->mm);
     213             : 
     214           0 :                 seq_release_private(inode, file);
     215           0 :                 return err;
     216             :         }
     217             : 
     218             :         return 0;
     219             : }
     220             : 
     221           0 : static int proc_map_release(struct inode *inode, struct file *file)
     222             : {
     223           0 :         struct seq_file *seq = file->private_data;
     224           0 :         struct proc_maps_private *priv = seq->private;
     225             : 
     226           0 :         if (priv->mm)
     227           0 :                 mmdrop(priv->mm);
     228             : 
     229           0 :         return seq_release_private(inode, file);
     230             : }
     231             : 
     232             : static int do_maps_open(struct inode *inode, struct file *file,
     233             :                         const struct seq_operations *ops)
     234             : {
     235           0 :         return proc_maps_open(inode, file, ops,
     236             :                                 sizeof(struct proc_maps_private));
     237             : }
     238             : 
     239             : /*
     240             :  * Indicate if the VMA is a stack for the given task; for
     241             :  * /proc/PID/maps that is the stack of the main task.
     242             :  */
     243             : static int is_stack(struct vm_area_struct *vma)
     244             : {
     245             :         /*
     246             :          * We make no effort to guess what a given thread considers to be
     247             :          * its "stack".  It's not even well-defined for programs written
     248             :          * languages like Go.
     249             :          */
     250           0 :         return vma->vm_start <= vma->vm_mm->start_stack &&
     251           0 :                 vma->vm_end >= vma->vm_mm->start_stack;
     252             : }
     253             : 
     254           0 : static void show_vma_header_prefix(struct seq_file *m,
     255             :                                    unsigned long start, unsigned long end,
     256             :                                    vm_flags_t flags, unsigned long long pgoff,
     257             :                                    dev_t dev, unsigned long ino)
     258             : {
     259           0 :         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
     260           0 :         seq_put_hex_ll(m, NULL, start, 8);
     261           0 :         seq_put_hex_ll(m, "-", end, 8);
     262           0 :         seq_putc(m, ' ');
     263           0 :         seq_putc(m, flags & VM_READ ? 'r' : '-');
     264           0 :         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
     265           0 :         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
     266           0 :         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
     267           0 :         seq_put_hex_ll(m, " ", pgoff, 8);
     268           0 :         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
     269           0 :         seq_put_hex_ll(m, ":", MINOR(dev), 2);
     270           0 :         seq_put_decimal_ull(m, " ", ino);
     271           0 :         seq_putc(m, ' ');
     272           0 : }
     273             : 
     274             : static void
     275           0 : show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
     276             : {
     277           0 :         struct anon_vma_name *anon_name = NULL;
     278           0 :         struct mm_struct *mm = vma->vm_mm;
     279           0 :         struct file *file = vma->vm_file;
     280           0 :         vm_flags_t flags = vma->vm_flags;
     281           0 :         unsigned long ino = 0;
     282           0 :         unsigned long long pgoff = 0;
     283             :         unsigned long start, end;
     284           0 :         dev_t dev = 0;
     285           0 :         const char *name = NULL;
     286             : 
     287           0 :         if (file) {
     288           0 :                 struct inode *inode = file_inode(vma->vm_file);
     289           0 :                 dev = inode->i_sb->s_dev;
     290           0 :                 ino = inode->i_ino;
     291           0 :                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
     292             :         }
     293             : 
     294           0 :         start = vma->vm_start;
     295           0 :         end = vma->vm_end;
     296           0 :         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
     297             :         if (mm)
     298             :                 anon_name = anon_vma_name(vma);
     299             : 
     300             :         /*
     301             :          * Print the dentry name for named mappings, and a
     302             :          * special [heap] marker for the heap:
     303             :          */
     304           0 :         if (file) {
     305           0 :                 seq_pad(m, ' ');
     306             :                 /*
     307             :                  * If user named this anon shared memory via
     308             :                  * prctl(PR_SET_VMA ..., use the provided name.
     309             :                  */
     310             :                 if (anon_name)
     311             :                         seq_printf(m, "[anon_shmem:%s]", anon_name->name);
     312             :                 else
     313           0 :                         seq_file_path(m, file, "\n");
     314             :                 goto done;
     315             :         }
     316             : 
     317           0 :         if (vma->vm_ops && vma->vm_ops->name) {
     318           0 :                 name = vma->vm_ops->name(vma);
     319           0 :                 if (name)
     320             :                         goto done;
     321             :         }
     322             : 
     323           0 :         name = arch_vma_name(vma);
     324           0 :         if (!name) {
     325           0 :                 if (!mm) {
     326             :                         name = "[vdso]";
     327             :                         goto done;
     328             :                 }
     329             : 
     330           0 :                 if (vma->vm_start <= mm->brk &&
     331           0 :                     vma->vm_end >= mm->start_brk) {
     332             :                         name = "[heap]";
     333             :                         goto done;
     334             :                 }
     335             : 
     336           0 :                 if (is_stack(vma)) {
     337             :                         name = "[stack]";
     338             :                         goto done;
     339             :                 }
     340             : 
     341             :                 if (anon_name) {
     342             :                         seq_pad(m, ' ');
     343             :                         seq_printf(m, "[anon:%s]", anon_name->name);
     344             :                 }
     345             :         }
     346             : 
     347             : done:
     348           0 :         if (name) {
     349           0 :                 seq_pad(m, ' ');
     350           0 :                 seq_puts(m, name);
     351             :         }
     352           0 :         seq_putc(m, '\n');
     353           0 : }
     354             : 
     355           0 : static int show_map(struct seq_file *m, void *v)
     356             : {
     357           0 :         show_map_vma(m, v);
     358           0 :         return 0;
     359             : }
     360             : 
     361             : static const struct seq_operations proc_pid_maps_op = {
     362             :         .start  = m_start,
     363             :         .next   = m_next,
     364             :         .stop   = m_stop,
     365             :         .show   = show_map
     366             : };
     367             : 
     368           0 : static int pid_maps_open(struct inode *inode, struct file *file)
     369             : {
     370           0 :         return do_maps_open(inode, file, &proc_pid_maps_op);
     371             : }
     372             : 
     373             : const struct file_operations proc_pid_maps_operations = {
     374             :         .open           = pid_maps_open,
     375             :         .read           = seq_read,
     376             :         .llseek         = seq_lseek,
     377             :         .release        = proc_map_release,
     378             : };
     379             : 
     380             : /*
     381             :  * Proportional Set Size(PSS): my share of RSS.
     382             :  *
     383             :  * PSS of a process is the count of pages it has in memory, where each
     384             :  * page is divided by the number of processes sharing it.  So if a
     385             :  * process has 1000 pages all to itself, and 1000 shared with one other
     386             :  * process, its PSS will be 1500.
     387             :  *
     388             :  * To keep (accumulated) division errors low, we adopt a 64bit
     389             :  * fixed-point pss counter to minimize division errors. So (pss >>
     390             :  * PSS_SHIFT) would be the real byte count.
     391             :  *
     392             :  * A shift of 12 before division means (assuming 4K page size):
     393             :  *      - 1M 3-user-pages add up to 8KB errors;
     394             :  *      - supports mapcount up to 2^24, or 16M;
     395             :  *      - supports PSS up to 2^52 bytes, or 4PB.
     396             :  */
     397             : #define PSS_SHIFT 12
     398             : 
     399             : #ifdef CONFIG_PROC_PAGE_MONITOR
     400             : struct mem_size_stats {
     401             :         unsigned long resident;
     402             :         unsigned long shared_clean;
     403             :         unsigned long shared_dirty;
     404             :         unsigned long private_clean;
     405             :         unsigned long private_dirty;
     406             :         unsigned long referenced;
     407             :         unsigned long anonymous;
     408             :         unsigned long lazyfree;
     409             :         unsigned long anonymous_thp;
     410             :         unsigned long shmem_thp;
     411             :         unsigned long file_thp;
     412             :         unsigned long swap;
     413             :         unsigned long shared_hugetlb;
     414             :         unsigned long private_hugetlb;
     415             :         u64 pss;
     416             :         u64 pss_anon;
     417             :         u64 pss_file;
     418             :         u64 pss_shmem;
     419             :         u64 pss_dirty;
     420             :         u64 pss_locked;
     421             :         u64 swap_pss;
     422             : };
     423             : 
     424           0 : static void smaps_page_accumulate(struct mem_size_stats *mss,
     425             :                 struct page *page, unsigned long size, unsigned long pss,
     426             :                 bool dirty, bool locked, bool private)
     427             : {
     428           0 :         mss->pss += pss;
     429             : 
     430           0 :         if (PageAnon(page))
     431           0 :                 mss->pss_anon += pss;
     432           0 :         else if (PageSwapBacked(page))
     433           0 :                 mss->pss_shmem += pss;
     434             :         else
     435           0 :                 mss->pss_file += pss;
     436             : 
     437           0 :         if (locked)
     438           0 :                 mss->pss_locked += pss;
     439             : 
     440           0 :         if (dirty || PageDirty(page)) {
     441           0 :                 mss->pss_dirty += pss;
     442           0 :                 if (private)
     443           0 :                         mss->private_dirty += size;
     444             :                 else
     445           0 :                         mss->shared_dirty += size;
     446             :         } else {
     447           0 :                 if (private)
     448           0 :                         mss->private_clean += size;
     449             :                 else
     450           0 :                         mss->shared_clean += size;
     451             :         }
     452           0 : }
     453             : 
     454           0 : static void smaps_account(struct mem_size_stats *mss, struct page *page,
     455             :                 bool compound, bool young, bool dirty, bool locked,
     456             :                 bool migration)
     457             : {
     458           0 :         int i, nr = compound ? compound_nr(page) : 1;
     459           0 :         unsigned long size = nr * PAGE_SIZE;
     460             : 
     461             :         /*
     462             :          * First accumulate quantities that depend only on |size| and the type
     463             :          * of the compound page.
     464             :          */
     465           0 :         if (PageAnon(page)) {
     466           0 :                 mss->anonymous += size;
     467           0 :                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
     468           0 :                         mss->lazyfree += size;
     469             :         }
     470             : 
     471           0 :         mss->resident += size;
     472             :         /* Accumulate the size in pages that have been accessed. */
     473           0 :         if (young || page_is_young(page) || PageReferenced(page))
     474           0 :                 mss->referenced += size;
     475             : 
     476             :         /*
     477             :          * Then accumulate quantities that may depend on sharing, or that may
     478             :          * differ page-by-page.
     479             :          *
     480             :          * page_count(page) == 1 guarantees the page is mapped exactly once.
     481             :          * If any subpage of the compound page mapped with PTE it would elevate
     482             :          * page_count().
     483             :          *
     484             :          * The page_mapcount() is called to get a snapshot of the mapcount.
     485             :          * Without holding the page lock this snapshot can be slightly wrong as
     486             :          * we cannot always read the mapcount atomically.  It is not safe to
     487             :          * call page_mapcount() even with PTL held if the page is not mapped,
     488             :          * especially for migration entries.  Treat regular migration entries
     489             :          * as mapcount == 1.
     490             :          */
     491           0 :         if ((page_count(page) == 1) || migration) {
     492           0 :                 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
     493             :                         locked, true);
     494           0 :                 return;
     495             :         }
     496           0 :         for (i = 0; i < nr; i++, page++) {
     497           0 :                 int mapcount = page_mapcount(page);
     498           0 :                 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
     499           0 :                 if (mapcount >= 2)
     500           0 :                         pss /= mapcount;
     501           0 :                 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
     502             :                                       mapcount < 2);
     503             :         }
     504             : }
     505             : 
     506             : #ifdef CONFIG_SHMEM
     507           0 : static int smaps_pte_hole(unsigned long addr, unsigned long end,
     508             :                           __always_unused int depth, struct mm_walk *walk)
     509             : {
     510           0 :         struct mem_size_stats *mss = walk->private;
     511           0 :         struct vm_area_struct *vma = walk->vma;
     512             : 
     513           0 :         mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
     514             :                                               linear_page_index(vma, addr),
     515             :                                               linear_page_index(vma, end));
     516             : 
     517           0 :         return 0;
     518             : }
     519             : #else
     520             : #define smaps_pte_hole          NULL
     521             : #endif /* CONFIG_SHMEM */
     522             : 
     523             : static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
     524             : {
     525             : #ifdef CONFIG_SHMEM
     526           0 :         if (walk->ops->pte_hole) {
     527             :                 /* depth is not used */
     528           0 :                 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
     529             :         }
     530             : #endif
     531             : }
     532             : 
     533           0 : static void smaps_pte_entry(pte_t *pte, unsigned long addr,
     534             :                 struct mm_walk *walk)
     535             : {
     536           0 :         struct mem_size_stats *mss = walk->private;
     537           0 :         struct vm_area_struct *vma = walk->vma;
     538           0 :         bool locked = !!(vma->vm_flags & VM_LOCKED);
     539           0 :         struct page *page = NULL;
     540           0 :         bool migration = false, young = false, dirty = false;
     541             : 
     542           0 :         if (pte_present(*pte)) {
     543           0 :                 page = vm_normal_page(vma, addr, *pte);
     544           0 :                 young = pte_young(*pte);
     545           0 :                 dirty = pte_dirty(*pte);
     546           0 :         } else if (is_swap_pte(*pte)) {
     547           0 :                 swp_entry_t swpent = pte_to_swp_entry(*pte);
     548             : 
     549           0 :                 if (!non_swap_entry(swpent)) {
     550             :                         int mapcount;
     551             : 
     552           0 :                         mss->swap += PAGE_SIZE;
     553           0 :                         mapcount = swp_swapcount(swpent);
     554           0 :                         if (mapcount >= 2) {
     555           0 :                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
     556             : 
     557           0 :                                 do_div(pss_delta, mapcount);
     558           0 :                                 mss->swap_pss += pss_delta;
     559             :                         } else {
     560           0 :                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
     561             :                         }
     562           0 :                 } else if (is_pfn_swap_entry(swpent)) {
     563           0 :                         if (is_migration_entry(swpent))
     564           0 :                                 migration = true;
     565           0 :                         page = pfn_swap_entry_to_page(swpent);
     566             :                 }
     567             :         } else {
     568             :                 smaps_pte_hole_lookup(addr, walk);
     569             :                 return;
     570             :         }
     571             : 
     572           0 :         if (!page)
     573             :                 return;
     574             : 
     575           0 :         smaps_account(mss, page, false, young, dirty, locked, migration);
     576             : }
     577             : 
     578             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     579             : static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
     580             :                 struct mm_walk *walk)
     581             : {
     582             :         struct mem_size_stats *mss = walk->private;
     583             :         struct vm_area_struct *vma = walk->vma;
     584             :         bool locked = !!(vma->vm_flags & VM_LOCKED);
     585             :         struct page *page = NULL;
     586             :         bool migration = false;
     587             : 
     588             :         if (pmd_present(*pmd)) {
     589             :                 /* FOLL_DUMP will return -EFAULT on huge zero page */
     590             :                 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
     591             :         } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
     592             :                 swp_entry_t entry = pmd_to_swp_entry(*pmd);
     593             : 
     594             :                 if (is_migration_entry(entry)) {
     595             :                         migration = true;
     596             :                         page = pfn_swap_entry_to_page(entry);
     597             :                 }
     598             :         }
     599             :         if (IS_ERR_OR_NULL(page))
     600             :                 return;
     601             :         if (PageAnon(page))
     602             :                 mss->anonymous_thp += HPAGE_PMD_SIZE;
     603             :         else if (PageSwapBacked(page))
     604             :                 mss->shmem_thp += HPAGE_PMD_SIZE;
     605             :         else if (is_zone_device_page(page))
     606             :                 /* pass */;
     607             :         else
     608             :                 mss->file_thp += HPAGE_PMD_SIZE;
     609             : 
     610             :         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
     611             :                       locked, migration);
     612             : }
     613             : #else
     614             : static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
     615             :                 struct mm_walk *walk)
     616             : {
     617             : }
     618             : #endif
     619             : 
     620           0 : static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
     621             :                            struct mm_walk *walk)
     622             : {
     623           0 :         struct vm_area_struct *vma = walk->vma;
     624             :         pte_t *pte;
     625             :         spinlock_t *ptl;
     626             : 
     627           0 :         ptl = pmd_trans_huge_lock(pmd, vma);
     628             :         if (ptl) {
     629             :                 smaps_pmd_entry(pmd, addr, walk);
     630             :                 spin_unlock(ptl);
     631             :                 goto out;
     632             :         }
     633             : 
     634           0 :         if (pmd_trans_unstable(pmd))
     635             :                 goto out;
     636             :         /*
     637             :          * The mmap_lock held all the way back in m_start() is what
     638             :          * keeps khugepaged out of here and from collapsing things
     639             :          * in here.
     640             :          */
     641           0 :         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
     642           0 :         for (; addr != end; pte++, addr += PAGE_SIZE)
     643           0 :                 smaps_pte_entry(pte, addr, walk);
     644           0 :         pte_unmap_unlock(pte - 1, ptl);
     645             : out:
     646           0 :         cond_resched();
     647           0 :         return 0;
     648             : }
     649             : 
     650           0 : static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
     651             : {
     652             :         /*
     653             :          * Don't forget to update Documentation/ on changes.
     654             :          */
     655             :         static const char mnemonics[BITS_PER_LONG][2] = {
     656             :                 /*
     657             :                  * In case if we meet a flag we don't know about.
     658             :                  */
     659             :                 [0 ... (BITS_PER_LONG-1)] = "??",
     660             : 
     661             :                 [ilog2(VM_READ)]        = "rd",
     662             :                 [ilog2(VM_WRITE)]       = "wr",
     663             :                 [ilog2(VM_EXEC)]        = "ex",
     664             :                 [ilog2(VM_SHARED)]      = "sh",
     665             :                 [ilog2(VM_MAYREAD)]     = "mr",
     666             :                 [ilog2(VM_MAYWRITE)]    = "mw",
     667             :                 [ilog2(VM_MAYEXEC)]     = "me",
     668             :                 [ilog2(VM_MAYSHARE)]    = "ms",
     669             :                 [ilog2(VM_GROWSDOWN)]   = "gd",
     670             :                 [ilog2(VM_PFNMAP)]      = "pf",
     671             :                 [ilog2(VM_LOCKED)]      = "lo",
     672             :                 [ilog2(VM_IO)]          = "io",
     673             :                 [ilog2(VM_SEQ_READ)]    = "sr",
     674             :                 [ilog2(VM_RAND_READ)]   = "rr",
     675             :                 [ilog2(VM_DONTCOPY)]    = "dc",
     676             :                 [ilog2(VM_DONTEXPAND)]  = "de",
     677             :                 [ilog2(VM_LOCKONFAULT)] = "lf",
     678             :                 [ilog2(VM_ACCOUNT)]     = "ac",
     679             :                 [ilog2(VM_NORESERVE)]   = "nr",
     680             :                 [ilog2(VM_HUGETLB)]     = "ht",
     681             :                 [ilog2(VM_SYNC)]        = "sf",
     682             :                 [ilog2(VM_ARCH_1)]      = "ar",
     683             :                 [ilog2(VM_WIPEONFORK)]  = "wf",
     684             :                 [ilog2(VM_DONTDUMP)]    = "dd",
     685             : #ifdef CONFIG_ARM64_BTI
     686             :                 [ilog2(VM_ARM64_BTI)]   = "bt",
     687             : #endif
     688             : #ifdef CONFIG_MEM_SOFT_DIRTY
     689             :                 [ilog2(VM_SOFTDIRTY)]   = "sd",
     690             : #endif
     691             :                 [ilog2(VM_MIXEDMAP)]    = "mm",
     692             :                 [ilog2(VM_HUGEPAGE)]    = "hg",
     693             :                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
     694             :                 [ilog2(VM_MERGEABLE)]   = "mg",
     695             :                 [ilog2(VM_UFFD_MISSING)]= "um",
     696             :                 [ilog2(VM_UFFD_WP)]     = "uw",
     697             : #ifdef CONFIG_ARM64_MTE
     698             :                 [ilog2(VM_MTE)]         = "mt",
     699             :                 [ilog2(VM_MTE_ALLOWED)] = "",
     700             : #endif
     701             : #ifdef CONFIG_ARCH_HAS_PKEYS
     702             :                 /* These come out via ProtectionKey: */
     703             :                 [ilog2(VM_PKEY_BIT0)]   = "",
     704             :                 [ilog2(VM_PKEY_BIT1)]   = "",
     705             :                 [ilog2(VM_PKEY_BIT2)]   = "",
     706             :                 [ilog2(VM_PKEY_BIT3)]   = "",
     707             : #if VM_PKEY_BIT4
     708             :                 [ilog2(VM_PKEY_BIT4)]   = "",
     709             : #endif
     710             : #endif /* CONFIG_ARCH_HAS_PKEYS */
     711             : #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
     712             :                 [ilog2(VM_UFFD_MINOR)]  = "ui",
     713             : #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
     714             :         };
     715             :         size_t i;
     716             : 
     717           0 :         seq_puts(m, "VmFlags: ");
     718           0 :         for (i = 0; i < BITS_PER_LONG; i++) {
     719           0 :                 if (!mnemonics[i][0])
     720           0 :                         continue;
     721           0 :                 if (vma->vm_flags & (1UL << i)) {
     722           0 :                         seq_putc(m, mnemonics[i][0]);
     723           0 :                         seq_putc(m, mnemonics[i][1]);
     724           0 :                         seq_putc(m, ' ');
     725             :                 }
     726             :         }
     727           0 :         seq_putc(m, '\n');
     728           0 : }
     729             : 
     730             : #ifdef CONFIG_HUGETLB_PAGE
     731             : static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
     732             :                                  unsigned long addr, unsigned long end,
     733             :                                  struct mm_walk *walk)
     734             : {
     735             :         struct mem_size_stats *mss = walk->private;
     736             :         struct vm_area_struct *vma = walk->vma;
     737             :         struct page *page = NULL;
     738             : 
     739             :         if (pte_present(*pte)) {
     740             :                 page = vm_normal_page(vma, addr, *pte);
     741             :         } else if (is_swap_pte(*pte)) {
     742             :                 swp_entry_t swpent = pte_to_swp_entry(*pte);
     743             : 
     744             :                 if (is_pfn_swap_entry(swpent))
     745             :                         page = pfn_swap_entry_to_page(swpent);
     746             :         }
     747             :         if (page) {
     748             :                 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
     749             :                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
     750             :                 else
     751             :                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
     752             :         }
     753             :         return 0;
     754             : }
     755             : #else
     756             : #define smaps_hugetlb_range     NULL
     757             : #endif /* HUGETLB_PAGE */
     758             : 
     759             : static const struct mm_walk_ops smaps_walk_ops = {
     760             :         .pmd_entry              = smaps_pte_range,
     761             :         .hugetlb_entry          = smaps_hugetlb_range,
     762             : };
     763             : 
     764             : static const struct mm_walk_ops smaps_shmem_walk_ops = {
     765             :         .pmd_entry              = smaps_pte_range,
     766             :         .hugetlb_entry          = smaps_hugetlb_range,
     767             :         .pte_hole               = smaps_pte_hole,
     768             : };
     769             : 
     770             : /*
     771             :  * Gather mem stats from @vma with the indicated beginning
     772             :  * address @start, and keep them in @mss.
     773             :  *
     774             :  * Use vm_start of @vma as the beginning address if @start is 0.
     775             :  */
     776           0 : static void smap_gather_stats(struct vm_area_struct *vma,
     777             :                 struct mem_size_stats *mss, unsigned long start)
     778             : {
     779           0 :         const struct mm_walk_ops *ops = &smaps_walk_ops;
     780             : 
     781             :         /* Invalid start */
     782           0 :         if (start >= vma->vm_end)
     783             :                 return;
     784             : 
     785           0 :         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
     786             :                 /*
     787             :                  * For shared or readonly shmem mappings we know that all
     788             :                  * swapped out pages belong to the shmem object, and we can
     789             :                  * obtain the swap value much more efficiently. For private
     790             :                  * writable mappings, we might have COW pages that are
     791             :                  * not affected by the parent swapped out pages of the shmem
     792             :                  * object, so we have to distinguish them during the page walk.
     793             :                  * Unless we know that the shmem object (or the part mapped by
     794             :                  * our VMA) has no swapped out pages at all.
     795             :                  */
     796           0 :                 unsigned long shmem_swapped = shmem_swap_usage(vma);
     797             : 
     798           0 :                 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
     799             :                                         !(vma->vm_flags & VM_WRITE))) {
     800           0 :                         mss->swap += shmem_swapped;
     801             :                 } else {
     802             :                         ops = &smaps_shmem_walk_ops;
     803             :                 }
     804             :         }
     805             : 
     806             :         /* mmap_lock is held in m_start */
     807           0 :         if (!start)
     808           0 :                 walk_page_vma(vma, ops, mss);
     809             :         else
     810           0 :                 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
     811             : }
     812             : 
     813             : #define SEQ_PUT_DEC(str, val) \
     814             :                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
     815             : 
     816             : /* Show the contents common for smaps and smaps_rollup */
     817           0 : static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
     818             :         bool rollup_mode)
     819             : {
     820           0 :         SEQ_PUT_DEC("Rss:            ", mss->resident);
     821           0 :         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
     822           0 :         SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> PSS_SHIFT);
     823           0 :         if (rollup_mode) {
     824             :                 /*
     825             :                  * These are meaningful only for smaps_rollup, otherwise two of
     826             :                  * them are zero, and the other one is the same as Pss.
     827             :                  */
     828           0 :                 SEQ_PUT_DEC(" kB\nPss_Anon:       ",
     829             :                         mss->pss_anon >> PSS_SHIFT);
     830           0 :                 SEQ_PUT_DEC(" kB\nPss_File:       ",
     831             :                         mss->pss_file >> PSS_SHIFT);
     832           0 :                 SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
     833             :                         mss->pss_shmem >> PSS_SHIFT);
     834             :         }
     835           0 :         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
     836           0 :         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
     837           0 :         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
     838           0 :         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
     839           0 :         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
     840           0 :         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
     841           0 :         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
     842           0 :         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
     843           0 :         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
     844           0 :         SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
     845           0 :         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
     846           0 :         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
     847           0 :                                   mss->private_hugetlb >> 10, 7);
     848           0 :         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
     849           0 :         SEQ_PUT_DEC(" kB\nSwapPss:        ",
     850             :                                         mss->swap_pss >> PSS_SHIFT);
     851           0 :         SEQ_PUT_DEC(" kB\nLocked:         ",
     852             :                                         mss->pss_locked >> PSS_SHIFT);
     853           0 :         seq_puts(m, " kB\n");
     854           0 : }
     855             : 
     856           0 : static int show_smap(struct seq_file *m, void *v)
     857             : {
     858           0 :         struct vm_area_struct *vma = v;
     859             :         struct mem_size_stats mss;
     860             : 
     861           0 :         memset(&mss, 0, sizeof(mss));
     862             : 
     863           0 :         smap_gather_stats(vma, &mss, 0);
     864             : 
     865           0 :         show_map_vma(m, vma);
     866             : 
     867           0 :         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
     868           0 :         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
     869           0 :         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
     870           0 :         seq_puts(m, " kB\n");
     871             : 
     872           0 :         __show_smap(m, &mss, false);
     873             : 
     874           0 :         seq_printf(m, "THPeligible:    %d\n",
     875           0 :                    hugepage_vma_check(vma, vma->vm_flags, true, false, true));
     876             : 
     877             :         if (arch_pkeys_enabled())
     878             :                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
     879           0 :         show_smap_vma_flags(m, vma);
     880             : 
     881           0 :         return 0;
     882             : }
     883             : 
     884           0 : static int show_smaps_rollup(struct seq_file *m, void *v)
     885             : {
     886           0 :         struct proc_maps_private *priv = m->private;
     887             :         struct mem_size_stats mss;
     888           0 :         struct mm_struct *mm = priv->mm;
     889             :         struct vm_area_struct *vma;
     890           0 :         unsigned long vma_start = 0, last_vma_end = 0;
     891           0 :         int ret = 0;
     892           0 :         VMA_ITERATOR(vmi, mm, 0);
     893             : 
     894           0 :         priv->task = get_proc_task(priv->inode);
     895           0 :         if (!priv->task)
     896             :                 return -ESRCH;
     897             : 
     898           0 :         if (!mm || !mmget_not_zero(mm)) {
     899             :                 ret = -ESRCH;
     900             :                 goto out_put_task;
     901             :         }
     902             : 
     903           0 :         memset(&mss, 0, sizeof(mss));
     904             : 
     905           0 :         ret = mmap_read_lock_killable(mm);
     906           0 :         if (ret)
     907             :                 goto out_put_mm;
     908             : 
     909           0 :         hold_task_mempolicy(priv);
     910           0 :         vma = vma_next(&vmi);
     911             : 
     912           0 :         if (unlikely(!vma))
     913             :                 goto empty_set;
     914             : 
     915           0 :         vma_start = vma->vm_start;
     916             :         do {
     917           0 :                 smap_gather_stats(vma, &mss, 0);
     918           0 :                 last_vma_end = vma->vm_end;
     919             : 
     920             :                 /*
     921             :                  * Release mmap_lock temporarily if someone wants to
     922             :                  * access it for write request.
     923             :                  */
     924           0 :                 if (mmap_lock_is_contended(mm)) {
     925           0 :                         vma_iter_invalidate(&vmi);
     926           0 :                         mmap_read_unlock(mm);
     927           0 :                         ret = mmap_read_lock_killable(mm);
     928           0 :                         if (ret) {
     929             :                                 release_task_mempolicy(priv);
     930             :                                 goto out_put_mm;
     931             :                         }
     932             : 
     933             :                         /*
     934             :                          * After dropping the lock, there are four cases to
     935             :                          * consider. See the following example for explanation.
     936             :                          *
     937             :                          *   +------+------+-----------+
     938             :                          *   | VMA1 | VMA2 | VMA3      |
     939             :                          *   +------+------+-----------+
     940             :                          *   |      |      |           |
     941             :                          *  4k     8k     16k         400k
     942             :                          *
     943             :                          * Suppose we drop the lock after reading VMA2 due to
     944             :                          * contention, then we get:
     945             :                          *
     946             :                          *      last_vma_end = 16k
     947             :                          *
     948             :                          * 1) VMA2 is freed, but VMA3 exists:
     949             :                          *
     950             :                          *    vma_next(vmi) will return VMA3.
     951             :                          *    In this case, just continue from VMA3.
     952             :                          *
     953             :                          * 2) VMA2 still exists:
     954             :                          *
     955             :                          *    vma_next(vmi) will return VMA3.
     956             :                          *    In this case, just continue from VMA3.
     957             :                          *
     958             :                          * 3) No more VMAs can be found:
     959             :                          *
     960             :                          *    vma_next(vmi) will return NULL.
     961             :                          *    No more things to do, just break.
     962             :                          *
     963             :                          * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
     964             :                          *
     965             :                          *    vma_next(vmi) will return VMA' whose range
     966             :                          *    contains last_vma_end.
     967             :                          *    Iterate VMA' from last_vma_end.
     968             :                          */
     969           0 :                         vma = vma_next(&vmi);
     970             :                         /* Case 3 above */
     971           0 :                         if (!vma)
     972             :                                 break;
     973             : 
     974             :                         /* Case 1 and 2 above */
     975           0 :                         if (vma->vm_start >= last_vma_end)
     976           0 :                                 continue;
     977             : 
     978             :                         /* Case 4 above */
     979           0 :                         if (vma->vm_end > last_vma_end)
     980           0 :                                 smap_gather_stats(vma, &mss, last_vma_end);
     981             :                 }
     982           0 :         } for_each_vma(vmi, vma);
     983             : 
     984             : empty_set:
     985           0 :         show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
     986           0 :         seq_pad(m, ' ');
     987           0 :         seq_puts(m, "[rollup]\n");
     988             : 
     989           0 :         __show_smap(m, &mss, true);
     990             : 
     991           0 :         release_task_mempolicy(priv);
     992             :         mmap_read_unlock(mm);
     993             : 
     994             : out_put_mm:
     995           0 :         mmput(mm);
     996             : out_put_task:
     997           0 :         put_task_struct(priv->task);
     998           0 :         priv->task = NULL;
     999             : 
    1000           0 :         return ret;
    1001             : }
    1002             : #undef SEQ_PUT_DEC
    1003             : 
    1004             : static const struct seq_operations proc_pid_smaps_op = {
    1005             :         .start  = m_start,
    1006             :         .next   = m_next,
    1007             :         .stop   = m_stop,
    1008             :         .show   = show_smap
    1009             : };
    1010             : 
    1011           0 : static int pid_smaps_open(struct inode *inode, struct file *file)
    1012             : {
    1013           0 :         return do_maps_open(inode, file, &proc_pid_smaps_op);
    1014             : }
    1015             : 
    1016           0 : static int smaps_rollup_open(struct inode *inode, struct file *file)
    1017             : {
    1018             :         int ret;
    1019             :         struct proc_maps_private *priv;
    1020             : 
    1021           0 :         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
    1022           0 :         if (!priv)
    1023             :                 return -ENOMEM;
    1024             : 
    1025           0 :         ret = single_open(file, show_smaps_rollup, priv);
    1026           0 :         if (ret)
    1027             :                 goto out_free;
    1028             : 
    1029           0 :         priv->inode = inode;
    1030           0 :         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
    1031           0 :         if (IS_ERR(priv->mm)) {
    1032           0 :                 ret = PTR_ERR(priv->mm);
    1033             : 
    1034           0 :                 single_release(inode, file);
    1035           0 :                 goto out_free;
    1036             :         }
    1037             : 
    1038             :         return 0;
    1039             : 
    1040             : out_free:
    1041           0 :         kfree(priv);
    1042           0 :         return ret;
    1043             : }
    1044             : 
    1045           0 : static int smaps_rollup_release(struct inode *inode, struct file *file)
    1046             : {
    1047           0 :         struct seq_file *seq = file->private_data;
    1048           0 :         struct proc_maps_private *priv = seq->private;
    1049             : 
    1050           0 :         if (priv->mm)
    1051           0 :                 mmdrop(priv->mm);
    1052             : 
    1053           0 :         kfree(priv);
    1054           0 :         return single_release(inode, file);
    1055             : }
    1056             : 
    1057             : const struct file_operations proc_pid_smaps_operations = {
    1058             :         .open           = pid_smaps_open,
    1059             :         .read           = seq_read,
    1060             :         .llseek         = seq_lseek,
    1061             :         .release        = proc_map_release,
    1062             : };
    1063             : 
    1064             : const struct file_operations proc_pid_smaps_rollup_operations = {
    1065             :         .open           = smaps_rollup_open,
    1066             :         .read           = seq_read,
    1067             :         .llseek         = seq_lseek,
    1068             :         .release        = smaps_rollup_release,
    1069             : };
    1070             : 
    1071             : enum clear_refs_types {
    1072             :         CLEAR_REFS_ALL = 1,
    1073             :         CLEAR_REFS_ANON,
    1074             :         CLEAR_REFS_MAPPED,
    1075             :         CLEAR_REFS_SOFT_DIRTY,
    1076             :         CLEAR_REFS_MM_HIWATER_RSS,
    1077             :         CLEAR_REFS_LAST,
    1078             : };
    1079             : 
    1080             : struct clear_refs_private {
    1081             :         enum clear_refs_types type;
    1082             : };
    1083             : 
    1084             : #ifdef CONFIG_MEM_SOFT_DIRTY
    1085             : 
    1086             : static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
    1087             : {
    1088             :         struct page *page;
    1089             : 
    1090             :         if (!pte_write(pte))
    1091             :                 return false;
    1092             :         if (!is_cow_mapping(vma->vm_flags))
    1093             :                 return false;
    1094             :         if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
    1095             :                 return false;
    1096             :         page = vm_normal_page(vma, addr, pte);
    1097             :         if (!page)
    1098             :                 return false;
    1099             :         return page_maybe_dma_pinned(page);
    1100             : }
    1101             : 
    1102             : static inline void clear_soft_dirty(struct vm_area_struct *vma,
    1103             :                 unsigned long addr, pte_t *pte)
    1104             : {
    1105             :         /*
    1106             :          * The soft-dirty tracker uses #PF-s to catch writes
    1107             :          * to pages, so write-protect the pte as well. See the
    1108             :          * Documentation/admin-guide/mm/soft-dirty.rst for full description
    1109             :          * of how soft-dirty works.
    1110             :          */
    1111             :         pte_t ptent = *pte;
    1112             : 
    1113             :         if (pte_present(ptent)) {
    1114             :                 pte_t old_pte;
    1115             : 
    1116             :                 if (pte_is_pinned(vma, addr, ptent))
    1117             :                         return;
    1118             :                 old_pte = ptep_modify_prot_start(vma, addr, pte);
    1119             :                 ptent = pte_wrprotect(old_pte);
    1120             :                 ptent = pte_clear_soft_dirty(ptent);
    1121             :                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
    1122             :         } else if (is_swap_pte(ptent)) {
    1123             :                 ptent = pte_swp_clear_soft_dirty(ptent);
    1124             :                 set_pte_at(vma->vm_mm, addr, pte, ptent);
    1125             :         }
    1126             : }
    1127             : #else
    1128             : static inline void clear_soft_dirty(struct vm_area_struct *vma,
    1129             :                 unsigned long addr, pte_t *pte)
    1130             : {
    1131             : }
    1132             : #endif
    1133             : 
    1134             : #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
    1135             : static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
    1136             :                 unsigned long addr, pmd_t *pmdp)
    1137             : {
    1138             :         pmd_t old, pmd = *pmdp;
    1139             : 
    1140             :         if (pmd_present(pmd)) {
    1141             :                 /* See comment in change_huge_pmd() */
    1142             :                 old = pmdp_invalidate(vma, addr, pmdp);
    1143             :                 if (pmd_dirty(old))
    1144             :                         pmd = pmd_mkdirty(pmd);
    1145             :                 if (pmd_young(old))
    1146             :                         pmd = pmd_mkyoung(pmd);
    1147             : 
    1148             :                 pmd = pmd_wrprotect(pmd);
    1149             :                 pmd = pmd_clear_soft_dirty(pmd);
    1150             : 
    1151             :                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
    1152             :         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
    1153             :                 pmd = pmd_swp_clear_soft_dirty(pmd);
    1154             :                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
    1155             :         }
    1156             : }
    1157             : #else
    1158             : static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
    1159             :                 unsigned long addr, pmd_t *pmdp)
    1160             : {
    1161             : }
    1162             : #endif
    1163             : 
    1164           0 : static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
    1165             :                                 unsigned long end, struct mm_walk *walk)
    1166             : {
    1167           0 :         struct clear_refs_private *cp = walk->private;
    1168           0 :         struct vm_area_struct *vma = walk->vma;
    1169             :         pte_t *pte, ptent;
    1170             :         spinlock_t *ptl;
    1171             :         struct page *page;
    1172             : 
    1173           0 :         ptl = pmd_trans_huge_lock(pmd, vma);
    1174             :         if (ptl) {
    1175             :                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
    1176             :                         clear_soft_dirty_pmd(vma, addr, pmd);
    1177             :                         goto out;
    1178             :                 }
    1179             : 
    1180             :                 if (!pmd_present(*pmd))
    1181             :                         goto out;
    1182             : 
    1183             :                 page = pmd_page(*pmd);
    1184             : 
    1185             :                 /* Clear accessed and referenced bits. */
    1186             :                 pmdp_test_and_clear_young(vma, addr, pmd);
    1187             :                 test_and_clear_page_young(page);
    1188             :                 ClearPageReferenced(page);
    1189             : out:
    1190             :                 spin_unlock(ptl);
    1191             :                 return 0;
    1192             :         }
    1193             : 
    1194           0 :         if (pmd_trans_unstable(pmd))
    1195             :                 return 0;
    1196             : 
    1197           0 :         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
    1198           0 :         for (; addr != end; pte++, addr += PAGE_SIZE) {
    1199           0 :                 ptent = *pte;
    1200             : 
    1201           0 :                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
    1202           0 :                         clear_soft_dirty(vma, addr, pte);
    1203           0 :                         continue;
    1204             :                 }
    1205             : 
    1206           0 :                 if (!pte_present(ptent))
    1207           0 :                         continue;
    1208             : 
    1209           0 :                 page = vm_normal_page(vma, addr, ptent);
    1210           0 :                 if (!page)
    1211           0 :                         continue;
    1212             : 
    1213             :                 /* Clear accessed and referenced bits. */
    1214           0 :                 ptep_test_and_clear_young(vma, addr, pte);
    1215           0 :                 test_and_clear_page_young(page);
    1216             :                 ClearPageReferenced(page);
    1217             :         }
    1218           0 :         pte_unmap_unlock(pte - 1, ptl);
    1219           0 :         cond_resched();
    1220             :         return 0;
    1221             : }
    1222             : 
    1223           0 : static int clear_refs_test_walk(unsigned long start, unsigned long end,
    1224             :                                 struct mm_walk *walk)
    1225             : {
    1226           0 :         struct clear_refs_private *cp = walk->private;
    1227           0 :         struct vm_area_struct *vma = walk->vma;
    1228             : 
    1229           0 :         if (vma->vm_flags & VM_PFNMAP)
    1230             :                 return 1;
    1231             : 
    1232             :         /*
    1233             :          * Writing 1 to /proc/pid/clear_refs affects all pages.
    1234             :          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
    1235             :          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
    1236             :          * Writing 4 to /proc/pid/clear_refs affects all pages.
    1237             :          */
    1238           0 :         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
    1239             :                 return 1;
    1240           0 :         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
    1241             :                 return 1;
    1242           0 :         return 0;
    1243             : }
    1244             : 
    1245             : static const struct mm_walk_ops clear_refs_walk_ops = {
    1246             :         .pmd_entry              = clear_refs_pte_range,
    1247             :         .test_walk              = clear_refs_test_walk,
    1248             : };
    1249             : 
    1250           0 : static ssize_t clear_refs_write(struct file *file, const char __user *buf,
    1251             :                                 size_t count, loff_t *ppos)
    1252             : {
    1253             :         struct task_struct *task;
    1254             :         char buffer[PROC_NUMBUF];
    1255             :         struct mm_struct *mm;
    1256             :         struct vm_area_struct *vma;
    1257             :         enum clear_refs_types type;
    1258             :         int itype;
    1259             :         int rv;
    1260             : 
    1261           0 :         memset(buffer, 0, sizeof(buffer));
    1262           0 :         if (count > sizeof(buffer) - 1)
    1263           0 :                 count = sizeof(buffer) - 1;
    1264           0 :         if (copy_from_user(buffer, buf, count))
    1265             :                 return -EFAULT;
    1266           0 :         rv = kstrtoint(strstrip(buffer), 10, &itype);
    1267           0 :         if (rv < 0)
    1268           0 :                 return rv;
    1269           0 :         type = (enum clear_refs_types)itype;
    1270           0 :         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
    1271             :                 return -EINVAL;
    1272             : 
    1273           0 :         task = get_proc_task(file_inode(file));
    1274           0 :         if (!task)
    1275             :                 return -ESRCH;
    1276           0 :         mm = get_task_mm(task);
    1277           0 :         if (mm) {
    1278           0 :                 VMA_ITERATOR(vmi, mm, 0);
    1279             :                 struct mmu_notifier_range range;
    1280           0 :                 struct clear_refs_private cp = {
    1281             :                         .type = type,
    1282             :                 };
    1283             : 
    1284           0 :                 if (mmap_write_lock_killable(mm)) {
    1285             :                         count = -EINTR;
    1286             :                         goto out_mm;
    1287             :                 }
    1288           0 :                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
    1289             :                         /*
    1290             :                          * Writing 5 to /proc/pid/clear_refs resets the peak
    1291             :                          * resident set size to this mm's current rss value.
    1292             :                          */
    1293             :                         reset_mm_hiwater_rss(mm);
    1294             :                         goto out_unlock;
    1295             :                 }
    1296             : 
    1297           0 :                 if (type == CLEAR_REFS_SOFT_DIRTY) {
    1298           0 :                         for_each_vma(vmi, vma) {
    1299             :                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
    1300           0 :                                         continue;
    1301             :                                 vm_flags_clear(vma, VM_SOFTDIRTY);
    1302             :                                 vma_set_page_prot(vma);
    1303             :                         }
    1304             : 
    1305           0 :                         inc_tlb_flush_pending(mm);
    1306             :                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
    1307             :                                                 0, mm, 0, -1UL);
    1308             :                         mmu_notifier_invalidate_range_start(&range);
    1309             :                 }
    1310           0 :                 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
    1311           0 :                 if (type == CLEAR_REFS_SOFT_DIRTY) {
    1312           0 :                         mmu_notifier_invalidate_range_end(&range);
    1313           0 :                         flush_tlb_mm(mm);
    1314             :                         dec_tlb_flush_pending(mm);
    1315             :                 }
    1316             : out_unlock:
    1317             :                 mmap_write_unlock(mm);
    1318             : out_mm:
    1319           0 :                 mmput(mm);
    1320             :         }
    1321           0 :         put_task_struct(task);
    1322             : 
    1323           0 :         return count;
    1324             : }
    1325             : 
    1326             : const struct file_operations proc_clear_refs_operations = {
    1327             :         .write          = clear_refs_write,
    1328             :         .llseek         = noop_llseek,
    1329             : };
    1330             : 
    1331             : typedef struct {
    1332             :         u64 pme;
    1333             : } pagemap_entry_t;
    1334             : 
    1335             : struct pagemapread {
    1336             :         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
    1337             :         pagemap_entry_t *buffer;
    1338             :         bool show_pfn;
    1339             : };
    1340             : 
    1341             : #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
    1342             : #define PAGEMAP_WALK_MASK       (PMD_MASK)
    1343             : 
    1344             : #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
    1345             : #define PM_PFRAME_BITS          55
    1346             : #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
    1347             : #define PM_SOFT_DIRTY           BIT_ULL(55)
    1348             : #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
    1349             : #define PM_UFFD_WP              BIT_ULL(57)
    1350             : #define PM_FILE                 BIT_ULL(61)
    1351             : #define PM_SWAP                 BIT_ULL(62)
    1352             : #define PM_PRESENT              BIT_ULL(63)
    1353             : 
    1354             : #define PM_END_OF_BUFFER    1
    1355             : 
    1356             : static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
    1357             : {
    1358           0 :         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
    1359             : }
    1360             : 
    1361             : static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
    1362             :                           struct pagemapread *pm)
    1363             : {
    1364           0 :         pm->buffer[pm->pos++] = *pme;
    1365           0 :         if (pm->pos >= pm->len)
    1366             :                 return PM_END_OF_BUFFER;
    1367             :         return 0;
    1368             : }
    1369             : 
    1370           0 : static int pagemap_pte_hole(unsigned long start, unsigned long end,
    1371             :                             __always_unused int depth, struct mm_walk *walk)
    1372             : {
    1373           0 :         struct pagemapread *pm = walk->private;
    1374           0 :         unsigned long addr = start;
    1375           0 :         int err = 0;
    1376             : 
    1377           0 :         while (addr < end) {
    1378           0 :                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
    1379           0 :                 pagemap_entry_t pme = make_pme(0, 0);
    1380             :                 /* End of address space hole, which we mark as non-present. */
    1381             :                 unsigned long hole_end;
    1382             : 
    1383           0 :                 if (vma)
    1384           0 :                         hole_end = min(end, vma->vm_start);
    1385             :                 else
    1386             :                         hole_end = end;
    1387             : 
    1388           0 :                 for (; addr < hole_end; addr += PAGE_SIZE) {
    1389           0 :                         err = add_to_pagemap(addr, &pme, pm);
    1390           0 :                         if (err)
    1391             :                                 goto out;
    1392             :                 }
    1393             : 
    1394           0 :                 if (!vma)
    1395             :                         break;
    1396             : 
    1397             :                 /* Addresses in the VMA. */
    1398             :                 if (vma->vm_flags & VM_SOFTDIRTY)
    1399             :                         pme = make_pme(0, PM_SOFT_DIRTY);
    1400           0 :                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
    1401           0 :                         err = add_to_pagemap(addr, &pme, pm);
    1402           0 :                         if (err)
    1403             :                                 goto out;
    1404             :                 }
    1405             :         }
    1406             : out:
    1407           0 :         return err;
    1408             : }
    1409             : 
    1410           0 : static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
    1411             :                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
    1412             : {
    1413           0 :         u64 frame = 0, flags = 0;
    1414           0 :         struct page *page = NULL;
    1415           0 :         bool migration = false;
    1416             : 
    1417           0 :         if (pte_present(pte)) {
    1418           0 :                 if (pm->show_pfn)
    1419           0 :                         frame = pte_pfn(pte);
    1420           0 :                 flags |= PM_PRESENT;
    1421           0 :                 page = vm_normal_page(vma, addr, pte);
    1422           0 :                 if (pte_soft_dirty(pte))
    1423             :                         flags |= PM_SOFT_DIRTY;
    1424             :                 if (pte_uffd_wp(pte))
    1425             :                         flags |= PM_UFFD_WP;
    1426           0 :         } else if (is_swap_pte(pte)) {
    1427             :                 swp_entry_t entry;
    1428           0 :                 if (pte_swp_soft_dirty(pte))
    1429             :                         flags |= PM_SOFT_DIRTY;
    1430             :                 if (pte_swp_uffd_wp(pte))
    1431             :                         flags |= PM_UFFD_WP;
    1432           0 :                 entry = pte_to_swp_entry(pte);
    1433           0 :                 if (pm->show_pfn) {
    1434             :                         pgoff_t offset;
    1435             :                         /*
    1436             :                          * For PFN swap offsets, keeping the offset field
    1437             :                          * to be PFN only to be compatible with old smaps.
    1438             :                          */
    1439           0 :                         if (is_pfn_swap_entry(entry))
    1440           0 :                                 offset = swp_offset_pfn(entry);
    1441             :                         else
    1442           0 :                                 offset = swp_offset(entry);
    1443           0 :                         frame = swp_type(entry) |
    1444           0 :                             (offset << MAX_SWAPFILES_SHIFT);
    1445             :                 }
    1446           0 :                 flags |= PM_SWAP;
    1447           0 :                 migration = is_migration_entry(entry);
    1448           0 :                 if (is_pfn_swap_entry(entry))
    1449           0 :                         page = pfn_swap_entry_to_page(entry);
    1450             :                 if (pte_marker_entry_uffd_wp(entry))
    1451             :                         flags |= PM_UFFD_WP;
    1452             :         }
    1453             : 
    1454           0 :         if (page && !PageAnon(page))
    1455           0 :                 flags |= PM_FILE;
    1456           0 :         if (page && !migration && page_mapcount(page) == 1)
    1457           0 :                 flags |= PM_MMAP_EXCLUSIVE;
    1458             :         if (vma->vm_flags & VM_SOFTDIRTY)
    1459             :                 flags |= PM_SOFT_DIRTY;
    1460             : 
    1461           0 :         return make_pme(frame, flags);
    1462             : }
    1463             : 
    1464           0 : static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
    1465             :                              struct mm_walk *walk)
    1466             : {
    1467           0 :         struct vm_area_struct *vma = walk->vma;
    1468           0 :         struct pagemapread *pm = walk->private;
    1469             :         spinlock_t *ptl;
    1470             :         pte_t *pte, *orig_pte;
    1471           0 :         int err = 0;
    1472             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1473             :         bool migration = false;
    1474             : 
    1475             :         ptl = pmd_trans_huge_lock(pmdp, vma);
    1476             :         if (ptl) {
    1477             :                 u64 flags = 0, frame = 0;
    1478             :                 pmd_t pmd = *pmdp;
    1479             :                 struct page *page = NULL;
    1480             : 
    1481             :                 if (vma->vm_flags & VM_SOFTDIRTY)
    1482             :                         flags |= PM_SOFT_DIRTY;
    1483             : 
    1484             :                 if (pmd_present(pmd)) {
    1485             :                         page = pmd_page(pmd);
    1486             : 
    1487             :                         flags |= PM_PRESENT;
    1488             :                         if (pmd_soft_dirty(pmd))
    1489             :                                 flags |= PM_SOFT_DIRTY;
    1490             :                         if (pmd_uffd_wp(pmd))
    1491             :                                 flags |= PM_UFFD_WP;
    1492             :                         if (pm->show_pfn)
    1493             :                                 frame = pmd_pfn(pmd) +
    1494             :                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
    1495             :                 }
    1496             : #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
    1497             :                 else if (is_swap_pmd(pmd)) {
    1498             :                         swp_entry_t entry = pmd_to_swp_entry(pmd);
    1499             :                         unsigned long offset;
    1500             : 
    1501             :                         if (pm->show_pfn) {
    1502             :                                 if (is_pfn_swap_entry(entry))
    1503             :                                         offset = swp_offset_pfn(entry);
    1504             :                                 else
    1505             :                                         offset = swp_offset(entry);
    1506             :                                 offset = offset +
    1507             :                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
    1508             :                                 frame = swp_type(entry) |
    1509             :                                         (offset << MAX_SWAPFILES_SHIFT);
    1510             :                         }
    1511             :                         flags |= PM_SWAP;
    1512             :                         if (pmd_swp_soft_dirty(pmd))
    1513             :                                 flags |= PM_SOFT_DIRTY;
    1514             :                         if (pmd_swp_uffd_wp(pmd))
    1515             :                                 flags |= PM_UFFD_WP;
    1516             :                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
    1517             :                         migration = is_migration_entry(entry);
    1518             :                         page = pfn_swap_entry_to_page(entry);
    1519             :                 }
    1520             : #endif
    1521             : 
    1522             :                 if (page && !migration && page_mapcount(page) == 1)
    1523             :                         flags |= PM_MMAP_EXCLUSIVE;
    1524             : 
    1525             :                 for (; addr != end; addr += PAGE_SIZE) {
    1526             :                         pagemap_entry_t pme = make_pme(frame, flags);
    1527             : 
    1528             :                         err = add_to_pagemap(addr, &pme, pm);
    1529             :                         if (err)
    1530             :                                 break;
    1531             :                         if (pm->show_pfn) {
    1532             :                                 if (flags & PM_PRESENT)
    1533             :                                         frame++;
    1534             :                                 else if (flags & PM_SWAP)
    1535             :                                         frame += (1 << MAX_SWAPFILES_SHIFT);
    1536             :                         }
    1537             :                 }
    1538             :                 spin_unlock(ptl);
    1539             :                 return err;
    1540             :         }
    1541             : 
    1542             :         if (pmd_trans_unstable(pmdp))
    1543             :                 return 0;
    1544             : #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
    1545             : 
    1546             :         /*
    1547             :          * We can assume that @vma always points to a valid one and @end never
    1548             :          * goes beyond vma->vm_end.
    1549             :          */
    1550           0 :         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
    1551           0 :         for (; addr < end; pte++, addr += PAGE_SIZE) {
    1552             :                 pagemap_entry_t pme;
    1553             : 
    1554           0 :                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
    1555           0 :                 err = add_to_pagemap(addr, &pme, pm);
    1556           0 :                 if (err)
    1557             :                         break;
    1558             :         }
    1559           0 :         pte_unmap_unlock(orig_pte, ptl);
    1560             : 
    1561           0 :         cond_resched();
    1562             : 
    1563           0 :         return err;
    1564             : }
    1565             : 
    1566             : #ifdef CONFIG_HUGETLB_PAGE
    1567             : /* This function walks within one hugetlb entry in the single call */
    1568             : static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
    1569             :                                  unsigned long addr, unsigned long end,
    1570             :                                  struct mm_walk *walk)
    1571             : {
    1572             :         struct pagemapread *pm = walk->private;
    1573             :         struct vm_area_struct *vma = walk->vma;
    1574             :         u64 flags = 0, frame = 0;
    1575             :         int err = 0;
    1576             :         pte_t pte;
    1577             : 
    1578             :         if (vma->vm_flags & VM_SOFTDIRTY)
    1579             :                 flags |= PM_SOFT_DIRTY;
    1580             : 
    1581             :         pte = huge_ptep_get(ptep);
    1582             :         if (pte_present(pte)) {
    1583             :                 struct page *page = pte_page(pte);
    1584             : 
    1585             :                 if (!PageAnon(page))
    1586             :                         flags |= PM_FILE;
    1587             : 
    1588             :                 if (page_mapcount(page) == 1)
    1589             :                         flags |= PM_MMAP_EXCLUSIVE;
    1590             : 
    1591             :                 if (huge_pte_uffd_wp(pte))
    1592             :                         flags |= PM_UFFD_WP;
    1593             : 
    1594             :                 flags |= PM_PRESENT;
    1595             :                 if (pm->show_pfn)
    1596             :                         frame = pte_pfn(pte) +
    1597             :                                 ((addr & ~hmask) >> PAGE_SHIFT);
    1598             :         } else if (pte_swp_uffd_wp_any(pte)) {
    1599             :                 flags |= PM_UFFD_WP;
    1600             :         }
    1601             : 
    1602             :         for (; addr != end; addr += PAGE_SIZE) {
    1603             :                 pagemap_entry_t pme = make_pme(frame, flags);
    1604             : 
    1605             :                 err = add_to_pagemap(addr, &pme, pm);
    1606             :                 if (err)
    1607             :                         return err;
    1608             :                 if (pm->show_pfn && (flags & PM_PRESENT))
    1609             :                         frame++;
    1610             :         }
    1611             : 
    1612             :         cond_resched();
    1613             : 
    1614             :         return err;
    1615             : }
    1616             : #else
    1617             : #define pagemap_hugetlb_range   NULL
    1618             : #endif /* HUGETLB_PAGE */
    1619             : 
    1620             : static const struct mm_walk_ops pagemap_ops = {
    1621             :         .pmd_entry      = pagemap_pmd_range,
    1622             :         .pte_hole       = pagemap_pte_hole,
    1623             :         .hugetlb_entry  = pagemap_hugetlb_range,
    1624             : };
    1625             : 
    1626             : /*
    1627             :  * /proc/pid/pagemap - an array mapping virtual pages to pfns
    1628             :  *
    1629             :  * For each page in the address space, this file contains one 64-bit entry
    1630             :  * consisting of the following:
    1631             :  *
    1632             :  * Bits 0-54  page frame number (PFN) if present
    1633             :  * Bits 0-4   swap type if swapped
    1634             :  * Bits 5-54  swap offset if swapped
    1635             :  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
    1636             :  * Bit  56    page exclusively mapped
    1637             :  * Bit  57    pte is uffd-wp write-protected
    1638             :  * Bits 58-60 zero
    1639             :  * Bit  61    page is file-page or shared-anon
    1640             :  * Bit  62    page swapped
    1641             :  * Bit  63    page present
    1642             :  *
    1643             :  * If the page is not present but in swap, then the PFN contains an
    1644             :  * encoding of the swap file number and the page's offset into the
    1645             :  * swap. Unmapped pages return a null PFN. This allows determining
    1646             :  * precisely which pages are mapped (or in swap) and comparing mapped
    1647             :  * pages between processes.
    1648             :  *
    1649             :  * Efficient users of this interface will use /proc/pid/maps to
    1650             :  * determine which areas of memory are actually mapped and llseek to
    1651             :  * skip over unmapped regions.
    1652             :  */
    1653           0 : static ssize_t pagemap_read(struct file *file, char __user *buf,
    1654             :                             size_t count, loff_t *ppos)
    1655             : {
    1656           0 :         struct mm_struct *mm = file->private_data;
    1657             :         struct pagemapread pm;
    1658             :         unsigned long src;
    1659             :         unsigned long svpfn;
    1660             :         unsigned long start_vaddr;
    1661             :         unsigned long end_vaddr;
    1662           0 :         int ret = 0, copied = 0;
    1663             : 
    1664           0 :         if (!mm || !mmget_not_zero(mm))
    1665             :                 goto out;
    1666             : 
    1667           0 :         ret = -EINVAL;
    1668             :         /* file position must be aligned */
    1669           0 :         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
    1670             :                 goto out_mm;
    1671             : 
    1672           0 :         ret = 0;
    1673           0 :         if (!count)
    1674             :                 goto out_mm;
    1675             : 
    1676             :         /* do not disclose physical addresses: attack vector */
    1677           0 :         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
    1678             : 
    1679           0 :         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
    1680           0 :         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
    1681           0 :         ret = -ENOMEM;
    1682           0 :         if (!pm.buffer)
    1683             :                 goto out_mm;
    1684             : 
    1685           0 :         src = *ppos;
    1686           0 :         svpfn = src / PM_ENTRY_BYTES;
    1687           0 :         end_vaddr = mm->task_size;
    1688             : 
    1689             :         /* watch out for wraparound */
    1690           0 :         start_vaddr = end_vaddr;
    1691           0 :         if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
    1692           0 :                 ret = mmap_read_lock_killable(mm);
    1693           0 :                 if (ret)
    1694             :                         goto out_free;
    1695           0 :                 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
    1696             :                 mmap_read_unlock(mm);
    1697             :         }
    1698             : 
    1699             :         /* Ensure the address is inside the task */
    1700           0 :         if (start_vaddr > mm->task_size)
    1701           0 :                 start_vaddr = end_vaddr;
    1702             : 
    1703             :         /*
    1704             :          * The odds are that this will stop walking way
    1705             :          * before end_vaddr, because the length of the
    1706             :          * user buffer is tracked in "pm", and the walk
    1707             :          * will stop when we hit the end of the buffer.
    1708             :          */
    1709             :         ret = 0;
    1710           0 :         while (count && (start_vaddr < end_vaddr)) {
    1711             :                 int len;
    1712             :                 unsigned long end;
    1713             : 
    1714           0 :                 pm.pos = 0;
    1715           0 :                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
    1716             :                 /* overflow ? */
    1717           0 :                 if (end < start_vaddr || end > end_vaddr)
    1718           0 :                         end = end_vaddr;
    1719           0 :                 ret = mmap_read_lock_killable(mm);
    1720           0 :                 if (ret)
    1721             :                         goto out_free;
    1722           0 :                 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
    1723           0 :                 mmap_read_unlock(mm);
    1724           0 :                 start_vaddr = end;
    1725             : 
    1726           0 :                 len = min(count, PM_ENTRY_BYTES * pm.pos);
    1727           0 :                 if (copy_to_user(buf, pm.buffer, len)) {
    1728             :                         ret = -EFAULT;
    1729             :                         goto out_free;
    1730             :                 }
    1731           0 :                 copied += len;
    1732           0 :                 buf += len;
    1733           0 :                 count -= len;
    1734             :         }
    1735           0 :         *ppos += copied;
    1736           0 :         if (!ret || ret == PM_END_OF_BUFFER)
    1737           0 :                 ret = copied;
    1738             : 
    1739             : out_free:
    1740           0 :         kfree(pm.buffer);
    1741             : out_mm:
    1742           0 :         mmput(mm);
    1743             : out:
    1744           0 :         return ret;
    1745             : }
    1746             : 
    1747           0 : static int pagemap_open(struct inode *inode, struct file *file)
    1748             : {
    1749             :         struct mm_struct *mm;
    1750             : 
    1751           0 :         mm = proc_mem_open(inode, PTRACE_MODE_READ);
    1752           0 :         if (IS_ERR(mm))
    1753           0 :                 return PTR_ERR(mm);
    1754           0 :         file->private_data = mm;
    1755           0 :         return 0;
    1756             : }
    1757             : 
    1758           0 : static int pagemap_release(struct inode *inode, struct file *file)
    1759             : {
    1760           0 :         struct mm_struct *mm = file->private_data;
    1761             : 
    1762           0 :         if (mm)
    1763             :                 mmdrop(mm);
    1764           0 :         return 0;
    1765             : }
    1766             : 
    1767             : const struct file_operations proc_pagemap_operations = {
    1768             :         .llseek         = mem_lseek, /* borrow this */
    1769             :         .read           = pagemap_read,
    1770             :         .open           = pagemap_open,
    1771             :         .release        = pagemap_release,
    1772             : };
    1773             : #endif /* CONFIG_PROC_PAGE_MONITOR */
    1774             : 
    1775             : #ifdef CONFIG_NUMA
    1776             : 
    1777             : struct numa_maps {
    1778             :         unsigned long pages;
    1779             :         unsigned long anon;
    1780             :         unsigned long active;
    1781             :         unsigned long writeback;
    1782             :         unsigned long mapcount_max;
    1783             :         unsigned long dirty;
    1784             :         unsigned long swapcache;
    1785             :         unsigned long node[MAX_NUMNODES];
    1786             : };
    1787             : 
    1788             : struct numa_maps_private {
    1789             :         struct proc_maps_private proc_maps;
    1790             :         struct numa_maps md;
    1791             : };
    1792             : 
    1793             : static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
    1794             :                         unsigned long nr_pages)
    1795             : {
    1796             :         int count = page_mapcount(page);
    1797             : 
    1798             :         md->pages += nr_pages;
    1799             :         if (pte_dirty || PageDirty(page))
    1800             :                 md->dirty += nr_pages;
    1801             : 
    1802             :         if (PageSwapCache(page))
    1803             :                 md->swapcache += nr_pages;
    1804             : 
    1805             :         if (PageActive(page) || PageUnevictable(page))
    1806             :                 md->active += nr_pages;
    1807             : 
    1808             :         if (PageWriteback(page))
    1809             :                 md->writeback += nr_pages;
    1810             : 
    1811             :         if (PageAnon(page))
    1812             :                 md->anon += nr_pages;
    1813             : 
    1814             :         if (count > md->mapcount_max)
    1815             :                 md->mapcount_max = count;
    1816             : 
    1817             :         md->node[page_to_nid(page)] += nr_pages;
    1818             : }
    1819             : 
    1820             : static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
    1821             :                 unsigned long addr)
    1822             : {
    1823             :         struct page *page;
    1824             :         int nid;
    1825             : 
    1826             :         if (!pte_present(pte))
    1827             :                 return NULL;
    1828             : 
    1829             :         page = vm_normal_page(vma, addr, pte);
    1830             :         if (!page || is_zone_device_page(page))
    1831             :                 return NULL;
    1832             : 
    1833             :         if (PageReserved(page))
    1834             :                 return NULL;
    1835             : 
    1836             :         nid = page_to_nid(page);
    1837             :         if (!node_isset(nid, node_states[N_MEMORY]))
    1838             :                 return NULL;
    1839             : 
    1840             :         return page;
    1841             : }
    1842             : 
    1843             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1844             : static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
    1845             :                                               struct vm_area_struct *vma,
    1846             :                                               unsigned long addr)
    1847             : {
    1848             :         struct page *page;
    1849             :         int nid;
    1850             : 
    1851             :         if (!pmd_present(pmd))
    1852             :                 return NULL;
    1853             : 
    1854             :         page = vm_normal_page_pmd(vma, addr, pmd);
    1855             :         if (!page)
    1856             :                 return NULL;
    1857             : 
    1858             :         if (PageReserved(page))
    1859             :                 return NULL;
    1860             : 
    1861             :         nid = page_to_nid(page);
    1862             :         if (!node_isset(nid, node_states[N_MEMORY]))
    1863             :                 return NULL;
    1864             : 
    1865             :         return page;
    1866             : }
    1867             : #endif
    1868             : 
    1869             : static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
    1870             :                 unsigned long end, struct mm_walk *walk)
    1871             : {
    1872             :         struct numa_maps *md = walk->private;
    1873             :         struct vm_area_struct *vma = walk->vma;
    1874             :         spinlock_t *ptl;
    1875             :         pte_t *orig_pte;
    1876             :         pte_t *pte;
    1877             : 
    1878             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1879             :         ptl = pmd_trans_huge_lock(pmd, vma);
    1880             :         if (ptl) {
    1881             :                 struct page *page;
    1882             : 
    1883             :                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
    1884             :                 if (page)
    1885             :                         gather_stats(page, md, pmd_dirty(*pmd),
    1886             :                                      HPAGE_PMD_SIZE/PAGE_SIZE);
    1887             :                 spin_unlock(ptl);
    1888             :                 return 0;
    1889             :         }
    1890             : 
    1891             :         if (pmd_trans_unstable(pmd))
    1892             :                 return 0;
    1893             : #endif
    1894             :         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
    1895             :         do {
    1896             :                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
    1897             :                 if (!page)
    1898             :                         continue;
    1899             :                 gather_stats(page, md, pte_dirty(*pte), 1);
    1900             : 
    1901             :         } while (pte++, addr += PAGE_SIZE, addr != end);
    1902             :         pte_unmap_unlock(orig_pte, ptl);
    1903             :         cond_resched();
    1904             :         return 0;
    1905             : }
    1906             : #ifdef CONFIG_HUGETLB_PAGE
    1907             : static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
    1908             :                 unsigned long addr, unsigned long end, struct mm_walk *walk)
    1909             : {
    1910             :         pte_t huge_pte = huge_ptep_get(pte);
    1911             :         struct numa_maps *md;
    1912             :         struct page *page;
    1913             : 
    1914             :         if (!pte_present(huge_pte))
    1915             :                 return 0;
    1916             : 
    1917             :         page = pte_page(huge_pte);
    1918             : 
    1919             :         md = walk->private;
    1920             :         gather_stats(page, md, pte_dirty(huge_pte), 1);
    1921             :         return 0;
    1922             : }
    1923             : 
    1924             : #else
    1925             : static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
    1926             :                 unsigned long addr, unsigned long end, struct mm_walk *walk)
    1927             : {
    1928             :         return 0;
    1929             : }
    1930             : #endif
    1931             : 
    1932             : static const struct mm_walk_ops show_numa_ops = {
    1933             :         .hugetlb_entry = gather_hugetlb_stats,
    1934             :         .pmd_entry = gather_pte_stats,
    1935             : };
    1936             : 
    1937             : /*
    1938             :  * Display pages allocated per node and memory policy via /proc.
    1939             :  */
    1940             : static int show_numa_map(struct seq_file *m, void *v)
    1941             : {
    1942             :         struct numa_maps_private *numa_priv = m->private;
    1943             :         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
    1944             :         struct vm_area_struct *vma = v;
    1945             :         struct numa_maps *md = &numa_priv->md;
    1946             :         struct file *file = vma->vm_file;
    1947             :         struct mm_struct *mm = vma->vm_mm;
    1948             :         struct mempolicy *pol;
    1949             :         char buffer[64];
    1950             :         int nid;
    1951             : 
    1952             :         if (!mm)
    1953             :                 return 0;
    1954             : 
    1955             :         /* Ensure we start with an empty set of numa_maps statistics. */
    1956             :         memset(md, 0, sizeof(*md));
    1957             : 
    1958             :         pol = __get_vma_policy(vma, vma->vm_start);
    1959             :         if (pol) {
    1960             :                 mpol_to_str(buffer, sizeof(buffer), pol);
    1961             :                 mpol_cond_put(pol);
    1962             :         } else {
    1963             :                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
    1964             :         }
    1965             : 
    1966             :         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
    1967             : 
    1968             :         if (file) {
    1969             :                 seq_puts(m, " file=");
    1970             :                 seq_file_path(m, file, "\n\t= ");
    1971             :         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
    1972             :                 seq_puts(m, " heap");
    1973             :         } else if (is_stack(vma)) {
    1974             :                 seq_puts(m, " stack");
    1975             :         }
    1976             : 
    1977             :         if (is_vm_hugetlb_page(vma))
    1978             :                 seq_puts(m, " huge");
    1979             : 
    1980             :         /* mmap_lock is held by m_start */
    1981             :         walk_page_vma(vma, &show_numa_ops, md);
    1982             : 
    1983             :         if (!md->pages)
    1984             :                 goto out;
    1985             : 
    1986             :         if (md->anon)
    1987             :                 seq_printf(m, " anon=%lu", md->anon);
    1988             : 
    1989             :         if (md->dirty)
    1990             :                 seq_printf(m, " dirty=%lu", md->dirty);
    1991             : 
    1992             :         if (md->pages != md->anon && md->pages != md->dirty)
    1993             :                 seq_printf(m, " mapped=%lu", md->pages);
    1994             : 
    1995             :         if (md->mapcount_max > 1)
    1996             :                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
    1997             : 
    1998             :         if (md->swapcache)
    1999             :                 seq_printf(m, " swapcache=%lu", md->swapcache);
    2000             : 
    2001             :         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
    2002             :                 seq_printf(m, " active=%lu", md->active);
    2003             : 
    2004             :         if (md->writeback)
    2005             :                 seq_printf(m, " writeback=%lu", md->writeback);
    2006             : 
    2007             :         for_each_node_state(nid, N_MEMORY)
    2008             :                 if (md->node[nid])
    2009             :                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
    2010             : 
    2011             :         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
    2012             : out:
    2013             :         seq_putc(m, '\n');
    2014             :         return 0;
    2015             : }
    2016             : 
    2017             : static const struct seq_operations proc_pid_numa_maps_op = {
    2018             :         .start  = m_start,
    2019             :         .next   = m_next,
    2020             :         .stop   = m_stop,
    2021             :         .show   = show_numa_map,
    2022             : };
    2023             : 
    2024             : static int pid_numa_maps_open(struct inode *inode, struct file *file)
    2025             : {
    2026             :         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
    2027             :                                 sizeof(struct numa_maps_private));
    2028             : }
    2029             : 
    2030             : const struct file_operations proc_pid_numa_maps_operations = {
    2031             :         .open           = pid_numa_maps_open,
    2032             :         .read           = seq_read,
    2033             :         .llseek         = seq_lseek,
    2034             :         .release        = proc_map_release,
    2035             : };
    2036             : 
    2037             : #endif /* CONFIG_NUMA */

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