fs/proc/task_mmu.c

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