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/mm_inline.h>
   5 #include <linux/hugetlb.h>
   6 #include <linux/huge_mm.h>
   7 #include <linux/mount.h>
   8 #include <linux/seq_file.h>
   9 #include <linux/highmem.h>
  10 #include <linux/ptrace.h>
  11 #include <linux/slab.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/mempolicy.h>
  14 #include <linux/rmap.h>
  15 #include <linux/swap.h>
  16 #include <linux/sched/mm.h>
  17 #include <linux/swapops.h>
  18 #include <linux/mmu_notifier.h>
  19 #include <linux/page_idle.h>
  20 #include <linux/shmem_fs.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/pkeys.h>
  23
  24 #include <asm/elf.h>
  25 #include <asm/tlb.h>
  26 #include <asm/tlbflush.h>
  27 #include "internal.h"
  28
  29 #define SEQ_PUT_DEC(str, val) \
  30                 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
  31 void task_mem(struct seq_file *m, struct mm_struct *mm)
  32 {
  33         unsigned long text, lib, swap, anon, file, shmem;
  34         unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  35
  36         anon = get_mm_counter(mm, MM_ANONPAGES);
  37         file = get_mm_counter(mm, MM_FILEPAGES);
  38         shmem = get_mm_counter(mm, MM_SHMEMPAGES);
  39
  40         /*
  41          * Note: to minimize their overhead, mm maintains hiwater_vm and
  42          * hiwater_rss only when about to *lower* total_vm or rss.  Any
  43          * collector of these hiwater stats must therefore get total_vm
  44          * and rss too, which will usually be the higher.  Barriers? not
  45          * worth the effort, such snapshots can always be inconsistent.
  46          */
  47         hiwater_vm = total_vm = mm->total_vm;
  48         if (hiwater_vm < mm->hiwater_vm)
  49                 hiwater_vm = mm->hiwater_vm;
  50         hiwater_rss = total_rss = anon + file + shmem;
  51         if (hiwater_rss < mm->hiwater_rss)
  52                 hiwater_rss = mm->hiwater_rss;
  53
  54         /* split executable areas between text and lib */
  55         text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
  56         text = min(text, mm->exec_vm << PAGE_SHIFT);
  57         lib = (mm->exec_vm << PAGE_SHIFT) - text;
  58
  59         swap = get_mm_counter(mm, MM_SWAPENTS);
  60         SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
  61         SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
  62         SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
  63         SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
  64         SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
  65         SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
  66         SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
  67         SEQ_PUT_DEC(" kB\nRssFile:\t", file);
  68         SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
  69         SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
  70         SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
  71         seq_put_decimal_ull_width(m,
  72                     " kB\nVmExe:\t", text >> 10, 8);
  73         seq_put_decimal_ull_width(m,
  74                     " kB\nVmLib:\t", lib >> 10, 8);
  75         seq_put_decimal_ull_width(m,
  76                     " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
  77         SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
  78         seq_puts(m, " kB\n");
  79         hugetlb_report_usage(m, mm);
  80 }
  81 #undef SEQ_PUT_DEC
  82
  83 unsigned long task_vsize(struct mm_struct *mm)
  84 {
  85         return PAGE_SIZE * mm->total_vm;
  86 }
  87
  88 unsigned long task_statm(struct mm_struct *mm,
  89                          unsigned long *shared, unsigned long *text,
  90                          unsigned long *data, unsigned long *resident)
  91 {
  92         *shared = get_mm_counter(mm, MM_FILEPAGES) +
  93                         get_mm_counter(mm, MM_SHMEMPAGES);
  94         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  95                                                                 >> PAGE_SHIFT;
  96         *data = mm->data_vm + mm->stack_vm;
  97         *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
  98         return mm->total_vm;
  99 }
 100
 101 #ifdef CONFIG_NUMA
 102 /*
 103  * Save get_task_policy() for show_numa_map().
 104  */
 105 static void hold_task_mempolicy(struct proc_maps_private *priv)
 106 {
 107         struct task_struct *task = priv->task;
 108
 109         task_lock(task);
 110         priv->task_mempolicy = get_task_policy(task);
 111         mpol_get(priv->task_mempolicy);
 112         task_unlock(task);
 113 }
 114 static void release_task_mempolicy(struct proc_maps_private *priv)
 115 {
 116         mpol_put(priv->task_mempolicy);
 117 }
 118 #else
 119 static void hold_task_mempolicy(struct proc_maps_private *priv)
 120 {
 121 }
 122 static void release_task_mempolicy(struct proc_maps_private *priv)
 123 {
 124 }
 125 #endif
 126
 127 static void *m_start(struct seq_file *m, loff_t *ppos)
 128 {
 129         struct proc_maps_private *priv = m->private;
 130         unsigned long last_addr = *ppos;
 131         struct mm_struct *mm;
 132         struct vm_area_struct *vma;
 133
 134         /* See m_next(). Zero at the start or after lseek. */
 135         if (last_addr == -1UL)
 136                 return NULL;
 137
 138         priv->task = get_proc_task(priv->inode);
 139         if (!priv->task)
 140                 return ERR_PTR(-ESRCH);
 141
 142         mm = priv->mm;
 143         if (!mm || !mmget_not_zero(mm)) {
 144                 put_task_struct(priv->task);
 145                 priv->task = NULL;
 146                 return NULL;
 147         }
 148
 149         if (mmap_read_lock_killable(mm)) {
 150                 mmput(mm);
 151                 put_task_struct(priv->task);
 152                 priv->task = NULL;
 153                 return ERR_PTR(-EINTR);
 154         }
 155
 156         hold_task_mempolicy(priv);
 157         priv->tail_vma = get_gate_vma(mm);
 158
 159         vma = find_vma(mm, last_addr);
 160         if (vma)
 161                 return vma;
 162
 163         return priv->tail_vma;
 164 }
 165
 166 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
 167 {
 168         struct proc_maps_private *priv = m->private;
 169         struct vm_area_struct *next, *vma = v;
 170
 171         if (vma == priv->tail_vma)
 172                 next = NULL;
 173         else if (vma->vm_next)
 174                 next = vma->vm_next;
 175         else
 176                 next = priv->tail_vma;
 177
 178         *ppos = next ? next->vm_start : -1UL;
 179
 180         return next;
 181 }
 182
 183 static void m_stop(struct seq_file *m, void *v)
 184 {
 185         struct proc_maps_private *priv = m->private;
 186         struct mm_struct *mm = priv->mm;
 187
 188         if (!priv->task)
 189                 return;
 190
 191         release_task_mempolicy(priv);
 192         mmap_read_unlock(mm);
 193         mmput(mm);
 194         put_task_struct(priv->task);
 195         priv->task = NULL;
 196 }
 197
 198 static int proc_maps_open(struct inode *inode, struct file *file,
 199                         const struct seq_operations *ops, int psize)
 200 {
 201         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
 202
 203         if (!priv)
 204                 return -ENOMEM;
 205
 206         priv->inode = inode;
 207         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 208         if (IS_ERR(priv->mm)) {
 209                 int err = PTR_ERR(priv->mm);
 210
 211                 seq_release_private(inode, file);
 212                 return err;
 213         }
 214
 215         return 0;
 216 }
 217
 218 static int proc_map_release(struct inode *inode, struct file *file)
 219 {
 220         struct seq_file *seq = file->private_data;
 221         struct proc_maps_private *priv = seq->private;
 222
 223         if (priv->mm)
 224                 mmdrop(priv->mm);
 225
 226         return seq_release_private(inode, file);
 227 }
 228
 229 static int do_maps_open(struct inode *inode, struct file *file,
 230                         const struct seq_operations *ops)
 231 {
 232         return proc_maps_open(inode, file, ops,
 233                                 sizeof(struct proc_maps_private));
 234 }
 235
 236 /*
 237  * Indicate if the VMA is a stack for the given task; for
 238  * /proc/PID/maps that is the stack of the main task.
 239  */
 240 static int is_stack(struct vm_area_struct *vma)
 241 {
 242         /*
 243          * We make no effort to guess what a given thread considers to be
 244          * its "stack".  It's not even well-defined for programs written
 245          * languages like Go.
 246          */
 247         return vma->vm_start <= vma->vm_mm->start_stack &&
 248                 vma->vm_end >= vma->vm_mm->start_stack;
 249 }
 250
 251 static void show_vma_header_prefix(struct seq_file *m,
 252                                    unsigned long start, unsigned long end,
 253                                    vm_flags_t flags, unsigned long long pgoff,
 254                                    dev_t dev, unsigned long ino)
 255 {
 256         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 257         seq_put_hex_ll(m, NULL, start, 8);
 258         seq_put_hex_ll(m, "-", end, 8);
 259         seq_putc(m, ' ');
 260         seq_putc(m, flags & VM_READ ? 'r' : '-');
 261         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
 262         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
 263         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
 264         seq_put_hex_ll(m, " ", pgoff, 8);
 265         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
 266         seq_put_hex_ll(m, ":", MINOR(dev), 2);
 267         seq_put_decimal_ull(m, " ", ino);
 268         seq_putc(m, ' ');
 269 }
 270
 271 static void
 272 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 273 {
 274         struct mm_struct *mm = vma->vm_mm;
 275         struct file *file = vma->vm_file;
 276         vm_flags_t flags = vma->vm_flags;
 277         unsigned long ino = 0;
 278         unsigned long long pgoff = 0;
 279         unsigned long start, end;
 280         dev_t dev = 0;
 281         const char *name = NULL;
 282
 283         if (file) {
 284                 struct inode *inode = file_inode(vma->vm_file);
 285                 dev = inode->i_sb->s_dev;
 286                 ino = inode->i_ino;
 287                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 288         }
 289
 290         start = vma->vm_start;
 291         end = vma->vm_end;
 292         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
 293
 294         /*
 295          * Print the dentry name for named mappings, and a
 296          * special [heap] marker for the heap:
 297          */
 298         if (file) {
 299                 seq_pad(m, ' ');
 300                 seq_file_path(m, file, "\n");
 301                 goto done;
 302         }
 303
 304         if (vma->vm_ops && vma->vm_ops->name) {
 305                 name = vma->vm_ops->name(vma);
 306                 if (name)
 307                         goto done;
 308         }
 309
 310         name = arch_vma_name(vma);
 311         if (!name) {
 312                 struct anon_vma_name *anon_name;
 313
 314                 if (!mm) {
 315                         name = "[vdso]";
 316                         goto done;
 317                 }
 318
 319                 if (vma->vm_start <= mm->brk &&
 320                     vma->vm_end >= mm->start_brk) {
 321                         name = "[heap]";
 322                         goto done;
 323                 }
 324
 325                 if (is_stack(vma)) {
 326                         name = "[stack]";
 327                         goto done;
 328                 }
 329
 330                 anon_name = anon_vma_name(vma);
 331                 if (anon_name) {
 332                         seq_pad(m, ' ');
 333                         seq_printf(m, "[anon:%s]", anon_name->name);
 334                 }
 335         }
 336
 337 done:
 338         if (name) {
 339                 seq_pad(m, ' ');
 340                 seq_puts(m, name);
 341         }
 342         seq_putc(m, '\n');
 343 }
 344
 345 static int show_map(struct seq_file *m, void *v)
 346 {
 347         show_map_vma(m, v);
 348         return 0;
 349 }
 350
 351 static const struct seq_operations proc_pid_maps_op = {
 352         .start  = m_start,
 353         .next   = m_next,
 354         .stop   = m_stop,
 355         .show   = show_map
 356 };
 357
 358 static int pid_maps_open(struct inode *inode, struct file *file)
 359 {
 360         return do_maps_open(inode, file, &proc_pid_maps_op);
 361 }
 362
 363 const struct file_operations proc_pid_maps_operations = {
 364         .open           = pid_maps_open,
 365         .read           = seq_read,
 366         .llseek         = seq_lseek,
 367         .release        = proc_map_release,
 368 };
 369
 370 /*
 371  * Proportional Set Size(PSS): my share of RSS.
 372  *
 373  * PSS of a process is the count of pages it has in memory, where each
 374  * page is divided by the number of processes sharing it.  So if a
 375  * process has 1000 pages all to itself, and 1000 shared with one other
 376  * process, its PSS will be 1500.
 377  *
 378  * To keep (accumulated) division errors low, we adopt a 64bit
 379  * fixed-point pss counter to minimize division errors. So (pss >>
 380  * PSS_SHIFT) would be the real byte count.
 381  *
 382  * A shift of 12 before division means (assuming 4K page size):
 383  *      - 1M 3-user-pages add up to 8KB errors;
 384  *      - supports mapcount up to 2^24, or 16M;
 385  *      - supports PSS up to 2^52 bytes, or 4PB.
 386  */
 387 #define PSS_SHIFT 12
 388
 389 #ifdef CONFIG_PROC_PAGE_MONITOR
 390 struct mem_size_stats {
 391         unsigned long resident;
 392         unsigned long shared_clean;
 393         unsigned long shared_dirty;
 394         unsigned long private_clean;
 395         unsigned long private_dirty;
 396         unsigned long referenced;
 397         unsigned long anonymous;
 398         unsigned long lazyfree;
 399         unsigned long anonymous_thp;
 400         unsigned long shmem_thp;
 401         unsigned long file_thp;
 402         unsigned long swap;
 403         unsigned long shared_hugetlb;
 404         unsigned long private_hugetlb;
 405         u64 pss;
 406         u64 pss_anon;
 407         u64 pss_file;
 408         u64 pss_shmem;
 409         u64 pss_locked;
 410         u64 swap_pss;
 411 };
 412
 413 static void smaps_page_accumulate(struct mem_size_stats *mss,
 414                 struct page *page, unsigned long size, unsigned long pss,
 415                 bool dirty, bool locked, bool private)
 416 {
 417         mss->pss += pss;
 418
 419         if (PageAnon(page))
 420                 mss->pss_anon += pss;
 421         else if (PageSwapBacked(page))
 422                 mss->pss_shmem += pss;
 423         else
 424                 mss->pss_file += pss;
 425
 426         if (locked)
 427                 mss->pss_locked += pss;
 428
 429         if (dirty || PageDirty(page)) {
 430                 if (private)
 431                         mss->private_dirty += size;
 432                 else
 433                         mss->shared_dirty += size;
 434         } else {
 435                 if (private)
 436                         mss->private_clean += size;
 437                 else
 438                         mss->shared_clean += size;
 439         }
 440 }
 441
 442 static void smaps_account(struct mem_size_stats *mss, struct page *page,
 443                 bool compound, bool young, bool dirty, bool locked,
 444                 bool migration)
 445 {
 446         int i, nr = compound ? compound_nr(page) : 1;
 447         unsigned long size = nr * PAGE_SIZE;
 448
 449         /*
 450          * First accumulate quantities that depend only on |size| and the type
 451          * of the compound page.
 452          */
 453         if (PageAnon(page)) {
 454                 mss->anonymous += size;
 455                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
 456                         mss->lazyfree += size;
 457         }
 458
 459         mss->resident += size;
 460         /* Accumulate the size in pages that have been accessed. */
 461         if (young || page_is_young(page) || PageReferenced(page))
 462                 mss->referenced += size;
 463
 464         /*
 465          * Then accumulate quantities that may depend on sharing, or that may
 466          * differ page-by-page.
 467          *
 468          * page_count(page) == 1 guarantees the page is mapped exactly once.
 469          * If any subpage of the compound page mapped with PTE it would elevate
 470          * page_count().
 471          *
 472          * The page_mapcount() is called to get a snapshot of the mapcount.
 473          * Without holding the page lock this snapshot can be slightly wrong as
 474          * we cannot always read the mapcount atomically.  It is not safe to
 475          * call page_mapcount() even with PTL held if the page is not mapped,
 476          * especially for migration entries.  Treat regular migration entries
 477          * as mapcount == 1.
 478          */
 479         if ((page_count(page) == 1) || migration) {
 480                 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
 481                         locked, true);
 482                 return;
 483         }
 484         for (i = 0; i < nr; i++, page++) {
 485                 int mapcount = page_mapcount(page);
 486                 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
 487                 if (mapcount >= 2)
 488                         pss /= mapcount;
 489                 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
 490                                       mapcount < 2);
 491         }
 492 }
 493
 494 #ifdef CONFIG_SHMEM
 495 static int smaps_pte_hole(unsigned long addr, unsigned long end,
 496                           __always_unused int depth, struct mm_walk *walk)
 497 {
 498         struct mem_size_stats *mss = walk->private;
 499         struct vm_area_struct *vma = walk->vma;
 500
 501         mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
 502                                               linear_page_index(vma, addr),
 503                                               linear_page_index(vma, end));
 504
 505         return 0;
 506 }
 507 #else
 508 #define smaps_pte_hole          NULL
 509 #endif /* CONFIG_SHMEM */
 510
 511 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
 512 {
 513 #ifdef CONFIG_SHMEM
 514         if (walk->ops->pte_hole) {
 515                 /* depth is not used */
 516                 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
 517         }
 518 #endif
 519 }
 520
 521 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 522                 struct mm_walk *walk)
 523 {
 524         struct mem_size_stats *mss = walk->private;
 525         struct vm_area_struct *vma = walk->vma;
 526         bool locked = !!(vma->vm_flags & VM_LOCKED);
 527         struct page *page = NULL;
 528         bool migration = false;
 529
 530         if (pte_present(*pte)) {
 531                 page = vm_normal_page(vma, addr, *pte);
 532         } else if (is_swap_pte(*pte)) {
 533                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 534
 535                 if (!non_swap_entry(swpent)) {
 536                         int mapcount;
 537
 538                         mss->swap += PAGE_SIZE;
 539                         mapcount = swp_swapcount(swpent);
 540                         if (mapcount >= 2) {
 541                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
 542
 543                                 do_div(pss_delta, mapcount);
 544                                 mss->swap_pss += pss_delta;
 545                         } else {
 546                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
 547                         }
 548                 } else if (is_pfn_swap_entry(swpent)) {
 549                         if (is_migration_entry(swpent))
 550                                 migration = true;
 551                         page = pfn_swap_entry_to_page(swpent);
 552                 }
 553         } else {
 554                 smaps_pte_hole_lookup(addr, walk);
 555                 return;
 556         }
 557
 558         if (!page)
 559                 return;
 560
 561         smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte),
 562                       locked, migration);
 563 }
 564
 565 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 566 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 567                 struct mm_walk *walk)
 568 {
 569         struct mem_size_stats *mss = walk->private;
 570         struct vm_area_struct *vma = walk->vma;
 571         bool locked = !!(vma->vm_flags & VM_LOCKED);
 572         struct page *page = NULL;
 573         bool migration = false;
 574
 575         if (pmd_present(*pmd)) {
 576                 /* FOLL_DUMP will return -EFAULT on huge zero page */
 577                 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
 578         } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
 579                 swp_entry_t entry = pmd_to_swp_entry(*pmd);
 580
 581                 if (is_migration_entry(entry)) {
 582                         migration = true;
 583                         page = pfn_swap_entry_to_page(entry);
 584                 }
 585         }
 586         if (IS_ERR_OR_NULL(page))
 587                 return;
 588         if (PageAnon(page))
 589                 mss->anonymous_thp += HPAGE_PMD_SIZE;
 590         else if (PageSwapBacked(page))
 591                 mss->shmem_thp += HPAGE_PMD_SIZE;
 592         else if (is_zone_device_page(page))
 593                 /* pass */;
 594         else
 595                 mss->file_thp += HPAGE_PMD_SIZE;
 596
 597         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
 598                       locked, migration);
 599 }
 600 #else
 601 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 602                 struct mm_walk *walk)
 603 {
 604 }
 605 #endif
 606
 607 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 608                            struct mm_walk *walk)
 609 {
 610         struct vm_area_struct *vma = walk->vma;
 611         pte_t *pte;
 612         spinlock_t *ptl;
 613
 614         ptl = pmd_trans_huge_lock(pmd, vma);
 615         if (ptl) {
 616                 smaps_pmd_entry(pmd, addr, walk);
 617                 spin_unlock(ptl);
 618                 goto out;
 619         }
 620
 621         if (pmd_trans_unstable(pmd))
 622                 goto out;
 623         /*
 624          * The mmap_lock held all the way back in m_start() is what
 625          * keeps khugepaged out of here and from collapsing things
 626          * in here.
 627          */
 628         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 629         for (; addr != end; pte++, addr += PAGE_SIZE)
 630                 smaps_pte_entry(pte, addr, walk);
 631         pte_unmap_unlock(pte - 1, ptl);
 632 out:
 633         cond_resched();
 634         return 0;
 635 }
 636
 637 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 638 {
 639         /*
 640          * Don't forget to update Documentation/ on changes.
 641          */
 642         static const char mnemonics[BITS_PER_LONG][2] = {
 643                 /*
 644                  * In case if we meet a flag we don't know about.
 645                  */
 646                 [0 ... (BITS_PER_LONG-1)] = "??",
 647
 648                 [ilog2(VM_READ)]        = "rd",
 649                 [ilog2(VM_WRITE)]       = "wr",
 650                 [ilog2(VM_EXEC)]        = "ex",
 651                 [ilog2(VM_SHARED)]      = "sh",
 652                 [ilog2(VM_MAYREAD)]     = "mr",
 653                 [ilog2(VM_MAYWRITE)]    = "mw",
 654                 [ilog2(VM_MAYEXEC)]     = "me",
 655                 [ilog2(VM_MAYSHARE)]    = "ms",
 656                 [ilog2(VM_GROWSDOWN)]   = "gd",
 657                 [ilog2(VM_PFNMAP)]      = "pf",
 658                 [ilog2(VM_LOCKED)]      = "lo",
 659                 [ilog2(VM_IO)]          = "io",
 660                 [ilog2(VM_SEQ_READ)]    = "sr",
 661                 [ilog2(VM_RAND_READ)]   = "rr",
 662                 [ilog2(VM_DONTCOPY)]    = "dc",
 663                 [ilog2(VM_DONTEXPAND)]  = "de",
 664                 [ilog2(VM_ACCOUNT)]     = "ac",
 665                 [ilog2(VM_NORESERVE)]   = "nr",
 666                 [ilog2(VM_HUGETLB)]     = "ht",
 667                 [ilog2(VM_SYNC)]        = "sf",
 668                 [ilog2(VM_ARCH_1)]      = "ar",
 669                 [ilog2(VM_WIPEONFORK)]  = "wf",
 670                 [ilog2(VM_DONTDUMP)]    = "dd",
 671 #ifdef CONFIG_ARM64_BTI
 672                 [ilog2(VM_ARM64_BTI)]   = "bt",
 673 #endif
 674 #ifdef CONFIG_MEM_SOFT_DIRTY
 675                 [ilog2(VM_SOFTDIRTY)]   = "sd",
 676 #endif
 677                 [ilog2(VM_MIXEDMAP)]    = "mm",
 678                 [ilog2(VM_HUGEPAGE)]    = "hg",
 679                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
 680                 [ilog2(VM_MERGEABLE)]   = "mg",
 681                 [ilog2(VM_UFFD_MISSING)]= "um",
 682                 [ilog2(VM_UFFD_WP)]     = "uw",
 683 #ifdef CONFIG_ARM64_MTE
 684                 [ilog2(VM_MTE)]         = "mt",
 685                 [ilog2(VM_MTE_ALLOWED)] = "",
 686 #endif
 687 #ifdef CONFIG_ARCH_HAS_PKEYS
 688                 /* These come out via ProtectionKey: */
 689                 [ilog2(VM_PKEY_BIT0)]   = "",
 690                 [ilog2(VM_PKEY_BIT1)]   = "",
 691                 [ilog2(VM_PKEY_BIT2)]   = "",
 692                 [ilog2(VM_PKEY_BIT3)]   = "",
 693 #if VM_PKEY_BIT4
 694                 [ilog2(VM_PKEY_BIT4)]   = "",
 695 #endif
 696 #endif /* CONFIG_ARCH_HAS_PKEYS */
 697 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
 698                 [ilog2(VM_UFFD_MINOR)]  = "ui",
 699 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
 700         };
 701         size_t i;
 702
 703         seq_puts(m, "VmFlags: ");
 704         for (i = 0; i < BITS_PER_LONG; i++) {
 705                 if (!mnemonics[i][0])
 706                         continue;
 707                 if (vma->vm_flags & (1UL << i)) {
 708                         seq_putc(m, mnemonics[i][0]);
 709                         seq_putc(m, mnemonics[i][1]);
 710                         seq_putc(m, ' ');
 711                 }
 712         }
 713         seq_putc(m, '\n');
 714 }
 715
 716 #ifdef CONFIG_HUGETLB_PAGE
 717 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 718                                  unsigned long addr, unsigned long end,
 719                                  struct mm_walk *walk)
 720 {
 721         struct mem_size_stats *mss = walk->private;
 722         struct vm_area_struct *vma = walk->vma;
 723         struct page *page = NULL;
 724
 725         if (pte_present(*pte)) {
 726                 page = vm_normal_page(vma, addr, *pte);
 727         } else if (is_swap_pte(*pte)) {
 728                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 729
 730                 if (is_pfn_swap_entry(swpent))
 731                         page = pfn_swap_entry_to_page(swpent);
 732         }
 733         if (page) {
 734                 int mapcount = page_mapcount(page);
 735
 736                 if (mapcount >= 2)
 737                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
 738                 else
 739                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
 740         }
 741         return 0;
 742 }
 743 #else
 744 #define smaps_hugetlb_range     NULL
 745 #endif /* HUGETLB_PAGE */
 746
 747 static const struct mm_walk_ops smaps_walk_ops = {
 748         .pmd_entry              = smaps_pte_range,
 749         .hugetlb_entry          = smaps_hugetlb_range,
 750 };
 751
 752 static const struct mm_walk_ops smaps_shmem_walk_ops = {
 753         .pmd_entry              = smaps_pte_range,
 754         .hugetlb_entry          = smaps_hugetlb_range,
 755         .pte_hole               = smaps_pte_hole,
 756 };
 757
 758 /*
 759  * Gather mem stats from @vma with the indicated beginning
 760  * address @start, and keep them in @mss.
 761  *
 762  * Use vm_start of @vma as the beginning address if @start is 0.
 763  */
 764 static void smap_gather_stats(struct vm_area_struct *vma,
 765                 struct mem_size_stats *mss, unsigned long start)
 766 {
 767         const struct mm_walk_ops *ops = &smaps_walk_ops;
 768
 769         /* Invalid start */
 770         if (start >= vma->vm_end)
 771                 return;
 772
 773 #ifdef CONFIG_SHMEM
 774         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
 775                 /*
 776                  * For shared or readonly shmem mappings we know that all
 777                  * swapped out pages belong to the shmem object, and we can
 778                  * obtain the swap value much more efficiently. For private
 779                  * writable mappings, we might have COW pages that are
 780                  * not affected by the parent swapped out pages of the shmem
 781                  * object, so we have to distinguish them during the page walk.
 782                  * Unless we know that the shmem object (or the part mapped by
 783                  * our VMA) has no swapped out pages at all.
 784                  */
 785                 unsigned long shmem_swapped = shmem_swap_usage(vma);
 786
 787                 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
 788                                         !(vma->vm_flags & VM_WRITE))) {
 789                         mss->swap += shmem_swapped;
 790                 } else {
 791                         ops = &smaps_shmem_walk_ops;
 792                 }
 793         }
 794 #endif
 795         /* mmap_lock is held in m_start */
 796         if (!start)
 797                 walk_page_vma(vma, ops, mss);
 798         else
 799                 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
 800 }
 801
 802 #define SEQ_PUT_DEC(str, val) \
 803                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
 804
 805 /* Show the contents common for smaps and smaps_rollup */
 806 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
 807         bool rollup_mode)
 808 {
 809         SEQ_PUT_DEC("Rss:            ", mss->resident);
 810         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
 811         if (rollup_mode) {
 812                 /*
 813                  * These are meaningful only for smaps_rollup, otherwise two of
 814                  * them are zero, and the other one is the same as Pss.
 815                  */
 816                 SEQ_PUT_DEC(" kB\nPss_Anon:       ",
 817                         mss->pss_anon >> PSS_SHIFT);
 818                 SEQ_PUT_DEC(" kB\nPss_File:       ",
 819                         mss->pss_file >> PSS_SHIFT);
 820                 SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
 821                         mss->pss_shmem >> PSS_SHIFT);
 822         }
 823         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
 824         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
 825         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
 826         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
 827         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
 828         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
 829         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
 830         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
 831         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
 832         SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
 833         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
 834         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
 835                                   mss->private_hugetlb >> 10, 7);
 836         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
 837         SEQ_PUT_DEC(" kB\nSwapPss:        ",
 838                                         mss->swap_pss >> PSS_SHIFT);
 839         SEQ_PUT_DEC(" kB\nLocked:         ",
 840                                         mss->pss_locked >> PSS_SHIFT);
 841         seq_puts(m, " kB\n");
 842 }
 843
 844 static int show_smap(struct seq_file *m, void *v)
 845 {
 846         struct vm_area_struct *vma = v;
 847         struct mem_size_stats mss;
 848
 849         memset(&mss, 0, sizeof(mss));
 850
 851         smap_gather_stats(vma, &mss, 0);
 852
 853         show_map_vma(m, vma);
 854
 855         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
 856         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
 857         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
 858         seq_puts(m, " kB\n");
 859
 860         __show_smap(m, &mss, false);
 861
 862         seq_printf(m, "THPeligible:    %d\n",
 863                    transparent_hugepage_active(vma));
 864
 865         if (arch_pkeys_enabled())
 866                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
 867         show_smap_vma_flags(m, vma);
 868
 869         return 0;
 870 }
 871
 872 static int show_smaps_rollup(struct seq_file *m, void *v)
 873 {
 874         struct proc_maps_private *priv = m->private;
 875         struct mem_size_stats mss;
 876         struct mm_struct *mm;
 877         struct vm_area_struct *vma;
 878         unsigned long last_vma_end = 0;
 879         int ret = 0;
 880
 881         priv->task = get_proc_task(priv->inode);
 882         if (!priv->task)
 883                 return -ESRCH;
 884
 885         mm = priv->mm;
 886         if (!mm || !mmget_not_zero(mm)) {
 887                 ret = -ESRCH;
 888                 goto out_put_task;
 889         }
 890
 891         memset(&mss, 0, sizeof(mss));
 892
 893         ret = mmap_read_lock_killable(mm);
 894         if (ret)
 895                 goto out_put_mm;
 896
 897         hold_task_mempolicy(priv);
 898
 899         for (vma = priv->mm->mmap; vma;) {
 900                 smap_gather_stats(vma, &mss, 0);
 901                 last_vma_end = vma->vm_end;
 902
 903                 /*
 904                  * Release mmap_lock temporarily if someone wants to
 905                  * access it for write request.
 906                  */
 907                 if (mmap_lock_is_contended(mm)) {
 908                         mmap_read_unlock(mm);
 909                         ret = mmap_read_lock_killable(mm);
 910                         if (ret) {
 911                                 release_task_mempolicy(priv);
 912                                 goto out_put_mm;
 913                         }
 914
 915                         /*
 916                          * After dropping the lock, there are four cases to
 917                          * consider. See the following example for explanation.
 918                          *
 919                          *   +------+------+-----------+
 920                          *   | VMA1 | VMA2 | VMA3      |
 921                          *   +------+------+-----------+
 922                          *   |      |      |           |
 923                          *  4k     8k     16k         400k
 924                          *
 925                          * Suppose we drop the lock after reading VMA2 due to
 926                          * contention, then we get:
 927                          *
 928                          *      last_vma_end = 16k
 929                          *
 930                          * 1) VMA2 is freed, but VMA3 exists:
 931                          *
 932                          *    find_vma(mm, 16k - 1) will return VMA3.
 933                          *    In this case, just continue from VMA3.
 934                          *
 935                          * 2) VMA2 still exists:
 936                          *
 937                          *    find_vma(mm, 16k - 1) will return VMA2.
 938                          *    Iterate the loop like the original one.
 939                          *
 940                          * 3) No more VMAs can be found:
 941                          *
 942                          *    find_vma(mm, 16k - 1) will return NULL.
 943                          *    No more things to do, just break.
 944                          *
 945                          * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
 946                          *
 947                          *    find_vma(mm, 16k - 1) will return VMA' whose range
 948                          *    contains last_vma_end.
 949                          *    Iterate VMA' from last_vma_end.
 950                          */
 951                         vma = find_vma(mm, last_vma_end - 1);
 952                         /* Case 3 above */
 953                         if (!vma)
 954                                 break;
 955
 956                         /* Case 1 above */
 957                         if (vma->vm_start >= last_vma_end)
 958                                 continue;
 959
 960                         /* Case 4 above */
 961                         if (vma->vm_end > last_vma_end)
 962                                 smap_gather_stats(vma, &mss, last_vma_end);
 963                 }
 964                 /* Case 2 above */
 965                 vma = vma->vm_next;
 966         }
 967
 968         show_vma_header_prefix(m, priv->mm->mmap->vm_start,
 969                                last_vma_end, 0, 0, 0, 0);
 970         seq_pad(m, ' ');
 971         seq_puts(m, "[rollup]\n");
 972
 973         __show_smap(m, &mss, true);
 974
 975         release_task_mempolicy(priv);
 976         mmap_read_unlock(mm);
 977
 978 out_put_mm:
 979         mmput(mm);
 980 out_put_task:
 981         put_task_struct(priv->task);
 982         priv->task = NULL;
 983
 984         return ret;
 985 }
 986 #undef SEQ_PUT_DEC
 987
 988 static const struct seq_operations proc_pid_smaps_op = {
 989         .start  = m_start,
 990         .next   = m_next,
 991         .stop   = m_stop,
 992         .show   = show_smap
 993 };
 994
 995 static int pid_smaps_open(struct inode *inode, struct file *file)
 996 {
 997         return do_maps_open(inode, file, &proc_pid_smaps_op);
 998 }
 999
1000 static int smaps_rollup_open(struct inode *inode, struct file *file)
1001 {
1002         int ret;
1003         struct proc_maps_private *priv;
1004
1005         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1006         if (!priv)
1007                 return -ENOMEM;
1008
1009         ret = single_open(file, show_smaps_rollup, priv);
1010         if (ret)
1011                 goto out_free;
1012
1013         priv->inode = inode;
1014         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1015         if (IS_ERR(priv->mm)) {
1016                 ret = PTR_ERR(priv->mm);
1017
1018                 single_release(inode, file);
1019                 goto out_free;
1020         }
1021
1022         return 0;
1023
1024 out_free:
1025         kfree(priv);
1026         return ret;
1027 }
1028
1029 static int smaps_rollup_release(struct inode *inode, struct file *file)
1030 {
1031         struct seq_file *seq = file->private_data;
1032         struct proc_maps_private *priv = seq->private;
1033
1034         if (priv->mm)
1035                 mmdrop(priv->mm);
1036
1037         kfree(priv);
1038         return single_release(inode, file);
1039 }
1040
1041 const struct file_operations proc_pid_smaps_operations = {
1042         .open           = pid_smaps_open,
1043         .read           = seq_read,
1044         .llseek         = seq_lseek,
1045         .release        = proc_map_release,
1046 };
1047
1048 const struct file_operations proc_pid_smaps_rollup_operations = {
1049         .open           = smaps_rollup_open,
1050         .read           = seq_read,
1051         .llseek         = seq_lseek,
1052         .release        = smaps_rollup_release,
1053 };
1054
1055 enum clear_refs_types {
1056         CLEAR_REFS_ALL = 1,
1057         CLEAR_REFS_ANON,
1058         CLEAR_REFS_MAPPED,
1059         CLEAR_REFS_SOFT_DIRTY,
1060         CLEAR_REFS_MM_HIWATER_RSS,
1061         CLEAR_REFS_LAST,
1062 };
1063
1064 struct clear_refs_private {
1065         enum clear_refs_types type;
1066 };
1067
1068 #ifdef CONFIG_MEM_SOFT_DIRTY
1069
1070 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1071 {
1072         struct page *page;
1073
1074         if (!pte_write(pte))
1075                 return false;
1076         if (!is_cow_mapping(vma->vm_flags))
1077                 return false;
1078         if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1079                 return false;
1080         page = vm_normal_page(vma, addr, pte);
1081         if (!page)
1082                 return false;
1083         return page_maybe_dma_pinned(page);
1084 }
1085
1086 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1087                 unsigned long addr, pte_t *pte)
1088 {
1089         /*
1090          * The soft-dirty tracker uses #PF-s to catch writes
1091          * to pages, so write-protect the pte as well. See the
1092          * Documentation/admin-guide/mm/soft-dirty.rst for full description
1093          * of how soft-dirty works.
1094          */
1095         pte_t ptent = *pte;
1096
1097         if (pte_present(ptent)) {
1098                 pte_t old_pte;
1099
1100                 if (pte_is_pinned(vma, addr, ptent))
1101                         return;
1102                 old_pte = ptep_modify_prot_start(vma, addr, pte);
1103                 ptent = pte_wrprotect(old_pte);
1104                 ptent = pte_clear_soft_dirty(ptent);
1105                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1106         } else if (is_swap_pte(ptent)) {
1107                 ptent = pte_swp_clear_soft_dirty(ptent);
1108                 set_pte_at(vma->vm_mm, addr, pte, ptent);
1109         }
1110 }
1111 #else
1112 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1113                 unsigned long addr, pte_t *pte)
1114 {
1115 }
1116 #endif
1117
1118 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1119 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1120                 unsigned long addr, pmd_t *pmdp)
1121 {
1122         pmd_t old, pmd = *pmdp;
1123
1124         if (pmd_present(pmd)) {
1125                 /* See comment in change_huge_pmd() */
1126                 old = pmdp_invalidate(vma, addr, pmdp);
1127                 if (pmd_dirty(old))
1128                         pmd = pmd_mkdirty(pmd);
1129                 if (pmd_young(old))
1130                         pmd = pmd_mkyoung(pmd);
1131
1132                 pmd = pmd_wrprotect(pmd);
1133                 pmd = pmd_clear_soft_dirty(pmd);
1134
1135                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1136         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1137                 pmd = pmd_swp_clear_soft_dirty(pmd);
1138                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1139         }
1140 }
1141 #else
1142 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1143                 unsigned long addr, pmd_t *pmdp)
1144 {
1145 }
1146 #endif
1147
1148 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1149                                 unsigned long end, struct mm_walk *walk)
1150 {
1151         struct clear_refs_private *cp = walk->private;
1152         struct vm_area_struct *vma = walk->vma;
1153         pte_t *pte, ptent;
1154         spinlock_t *ptl;
1155         struct page *page;
1156
1157         ptl = pmd_trans_huge_lock(pmd, vma);
1158         if (ptl) {
1159                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1160                         clear_soft_dirty_pmd(vma, addr, pmd);
1161                         goto out;
1162                 }
1163
1164                 if (!pmd_present(*pmd))
1165                         goto out;
1166
1167                 page = pmd_page(*pmd);
1168
1169                 /* Clear accessed and referenced bits. */
1170                 pmdp_test_and_clear_young(vma, addr, pmd);
1171                 test_and_clear_page_young(page);
1172                 ClearPageReferenced(page);
1173 out:
1174                 spin_unlock(ptl);
1175                 return 0;
1176         }
1177
1178         if (pmd_trans_unstable(pmd))
1179                 return 0;
1180
1181         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1182         for (; addr != end; pte++, addr += PAGE_SIZE) {
1183                 ptent = *pte;
1184
1185                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1186                         clear_soft_dirty(vma, addr, pte);
1187                         continue;
1188                 }
1189
1190                 if (!pte_present(ptent))
1191                         continue;
1192
1193                 page = vm_normal_page(vma, addr, ptent);
1194                 if (!page)
1195                         continue;
1196
1197                 /* Clear accessed and referenced bits. */
1198                 ptep_test_and_clear_young(vma, addr, pte);
1199                 test_and_clear_page_young(page);
1200                 ClearPageReferenced(page);
1201         }
1202         pte_unmap_unlock(pte - 1, ptl);
1203         cond_resched();
1204         return 0;
1205 }
1206
1207 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1208                                 struct mm_walk *walk)
1209 {
1210         struct clear_refs_private *cp = walk->private;
1211         struct vm_area_struct *vma = walk->vma;
1212
1213         if (vma->vm_flags & VM_PFNMAP)
1214                 return 1;
1215
1216         /*
1217          * Writing 1 to /proc/pid/clear_refs affects all pages.
1218          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1219          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1220          * Writing 4 to /proc/pid/clear_refs affects all pages.
1221          */
1222         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1223                 return 1;
1224         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1225                 return 1;
1226         return 0;
1227 }
1228
1229 static const struct mm_walk_ops clear_refs_walk_ops = {
1230         .pmd_entry              = clear_refs_pte_range,
1231         .test_walk              = clear_refs_test_walk,
1232 };
1233
1234 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1235                                 size_t count, loff_t *ppos)
1236 {
1237         struct task_struct *task;
1238         char buffer[PROC_NUMBUF];
1239         struct mm_struct *mm;
1240         struct vm_area_struct *vma;
1241         enum clear_refs_types type;
1242         int itype;
1243         int rv;
1244
1245         memset(buffer, 0, sizeof(buffer));
1246         if (count > sizeof(buffer) - 1)
1247                 count = sizeof(buffer) - 1;
1248         if (copy_from_user(buffer, buf, count))
1249                 return -EFAULT;
1250         rv = kstrtoint(strstrip(buffer), 10, &itype);
1251         if (rv < 0)
1252                 return rv;
1253         type = (enum clear_refs_types)itype;
1254         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1255                 return -EINVAL;
1256
1257         task = get_proc_task(file_inode(file));
1258         if (!task)
1259                 return -ESRCH;
1260         mm = get_task_mm(task);
1261         if (mm) {
1262                 struct mmu_notifier_range range;
1263                 struct clear_refs_private cp = {
1264                         .type = type,
1265                 };
1266
1267                 if (mmap_write_lock_killable(mm)) {
1268                         count = -EINTR;
1269                         goto out_mm;
1270                 }
1271                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1272                         /*
1273                          * Writing 5 to /proc/pid/clear_refs resets the peak
1274                          * resident set size to this mm's current rss value.
1275                          */
1276                         reset_mm_hiwater_rss(mm);
1277                         goto out_unlock;
1278                 }
1279
1280                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1281                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1282                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1283                                         continue;
1284                                 vma->vm_flags &= ~VM_SOFTDIRTY;
1285                                 vma_set_page_prot(vma);
1286                         }
1287
1288                         inc_tlb_flush_pending(mm);
1289                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1290                                                 0, NULL, mm, 0, -1UL);
1291                         mmu_notifier_invalidate_range_start(&range);
1292                 }
1293                 walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
1294                                 &cp);
1295                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1296                         mmu_notifier_invalidate_range_end(&range);
1297                         flush_tlb_mm(mm);
1298                         dec_tlb_flush_pending(mm);
1299                 }
1300 out_unlock:
1301                 mmap_write_unlock(mm);
1302 out_mm:
1303                 mmput(mm);
1304         }
1305         put_task_struct(task);
1306
1307         return count;
1308 }
1309
1310 const struct file_operations proc_clear_refs_operations = {
1311         .write          = clear_refs_write,
1312         .llseek         = noop_llseek,
1313 };
1314
1315 typedef struct {
1316         u64 pme;
1317 } pagemap_entry_t;
1318
1319 struct pagemapread {
1320         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1321         pagemap_entry_t *buffer;
1322         bool show_pfn;
1323 };
1324
1325 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1326 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1327
1328 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1329 #define PM_PFRAME_BITS          55
1330 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1331 #define PM_SOFT_DIRTY           BIT_ULL(55)
1332 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1333 #define PM_UFFD_WP              BIT_ULL(57)
1334 #define PM_FILE                 BIT_ULL(61)
1335 #define PM_SWAP                 BIT_ULL(62)
1336 #define PM_PRESENT              BIT_ULL(63)
1337
1338 #define PM_END_OF_BUFFER    1
1339
1340 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1341 {
1342         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1343 }
1344
1345 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1346                           struct pagemapread *pm)
1347 {
1348         pm->buffer[pm->pos++] = *pme;
1349         if (pm->pos >= pm->len)
1350                 return PM_END_OF_BUFFER;
1351         return 0;
1352 }
1353
1354 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1355                             __always_unused int depth, struct mm_walk *walk)
1356 {
1357         struct pagemapread *pm = walk->private;
1358         unsigned long addr = start;
1359         int err = 0;
1360
1361         while (addr < end) {
1362                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1363                 pagemap_entry_t pme = make_pme(0, 0);
1364                 /* End of address space hole, which we mark as non-present. */
1365                 unsigned long hole_end;
1366
1367                 if (vma)
1368                         hole_end = min(end, vma->vm_start);
1369                 else
1370                         hole_end = end;
1371
1372                 for (; addr < hole_end; addr += PAGE_SIZE) {
1373                         err = add_to_pagemap(addr, &pme, pm);
1374                         if (err)
1375                                 goto out;
1376                 }
1377
1378                 if (!vma)
1379                         break;
1380
1381                 /* Addresses in the VMA. */
1382                 if (vma->vm_flags & VM_SOFTDIRTY)
1383                         pme = make_pme(0, PM_SOFT_DIRTY);
1384                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1385                         err = add_to_pagemap(addr, &pme, pm);
1386                         if (err)
1387                                 goto out;
1388                 }
1389         }
1390 out:
1391         return err;
1392 }
1393
1394 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1395                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1396 {
1397         u64 frame = 0, flags = 0;
1398         struct page *page = NULL;
1399         bool migration = false;
1400
1401         if (pte_present(pte)) {
1402                 if (pm->show_pfn)
1403                         frame = pte_pfn(pte);
1404                 flags |= PM_PRESENT;
1405                 page = vm_normal_page(vma, addr, pte);
1406                 if (pte_soft_dirty(pte))
1407                         flags |= PM_SOFT_DIRTY;
1408                 if (pte_uffd_wp(pte))
1409                         flags |= PM_UFFD_WP;
1410         } else if (is_swap_pte(pte)) {
1411                 swp_entry_t entry;
1412                 if (pte_swp_soft_dirty(pte))
1413                         flags |= PM_SOFT_DIRTY;
1414                 if (pte_swp_uffd_wp(pte))
1415                         flags |= PM_UFFD_WP;
1416                 entry = pte_to_swp_entry(pte);
1417                 if (pm->show_pfn)
1418                         frame = swp_type(entry) |
1419                                 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1420                 flags |= PM_SWAP;
1421                 migration = is_migration_entry(entry);
1422                 if (is_pfn_swap_entry(entry))
1423                         page = pfn_swap_entry_to_page(entry);
1424         }
1425
1426         if (page && !PageAnon(page))
1427                 flags |= PM_FILE;
1428         if (page && !migration && page_mapcount(page) == 1)
1429                 flags |= PM_MMAP_EXCLUSIVE;
1430         if (vma->vm_flags & VM_SOFTDIRTY)
1431                 flags |= PM_SOFT_DIRTY;
1432
1433         return make_pme(frame, flags);
1434 }
1435
1436 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1437                              struct mm_walk *walk)
1438 {
1439         struct vm_area_struct *vma = walk->vma;
1440         struct pagemapread *pm = walk->private;
1441         spinlock_t *ptl;
1442         pte_t *pte, *orig_pte;
1443         int err = 0;
1444 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1445         bool migration = false;
1446
1447         ptl = pmd_trans_huge_lock(pmdp, vma);
1448         if (ptl) {
1449                 u64 flags = 0, frame = 0;
1450                 pmd_t pmd = *pmdp;
1451                 struct page *page = NULL;
1452
1453                 if (vma->vm_flags & VM_SOFTDIRTY)
1454                         flags |= PM_SOFT_DIRTY;
1455
1456                 if (pmd_present(pmd)) {
1457                         page = pmd_page(pmd);
1458
1459                         flags |= PM_PRESENT;
1460                         if (pmd_soft_dirty(pmd))
1461                                 flags |= PM_SOFT_DIRTY;
1462                         if (pmd_uffd_wp(pmd))
1463                                 flags |= PM_UFFD_WP;
1464                         if (pm->show_pfn)
1465                                 frame = pmd_pfn(pmd) +
1466                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1467                 }
1468 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1469                 else if (is_swap_pmd(pmd)) {
1470                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1471                         unsigned long offset;
1472
1473                         if (pm->show_pfn) {
1474                                 offset = swp_offset(entry) +
1475                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1476                                 frame = swp_type(entry) |
1477                                         (offset << MAX_SWAPFILES_SHIFT);
1478                         }
1479                         flags |= PM_SWAP;
1480                         if (pmd_swp_soft_dirty(pmd))
1481                                 flags |= PM_SOFT_DIRTY;
1482                         if (pmd_swp_uffd_wp(pmd))
1483                                 flags |= PM_UFFD_WP;
1484                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1485                         migration = is_migration_entry(entry);
1486                         page = pfn_swap_entry_to_page(entry);
1487                 }
1488 #endif
1489
1490                 if (page && !migration && page_mapcount(page) == 1)
1491                         flags |= PM_MMAP_EXCLUSIVE;
1492
1493                 for (; addr != end; addr += PAGE_SIZE) {
1494                         pagemap_entry_t pme = make_pme(frame, flags);
1495
1496                         err = add_to_pagemap(addr, &pme, pm);
1497                         if (err)
1498                                 break;
1499                         if (pm->show_pfn) {
1500                                 if (flags & PM_PRESENT)
1501                                         frame++;
1502                                 else if (flags & PM_SWAP)
1503                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1504                         }
1505                 }
1506                 spin_unlock(ptl);
1507                 return err;
1508         }
1509
1510         if (pmd_trans_unstable(pmdp))
1511                 return 0;
1512 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1513
1514         /*
1515          * We can assume that @vma always points to a valid one and @end never
1516          * goes beyond vma->vm_end.
1517          */
1518         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1519         for (; addr < end; pte++, addr += PAGE_SIZE) {
1520                 pagemap_entry_t pme;
1521
1522                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1523                 err = add_to_pagemap(addr, &pme, pm);
1524                 if (err)
1525                         break;
1526         }
1527         pte_unmap_unlock(orig_pte, ptl);
1528
1529         cond_resched();
1530
1531         return err;
1532 }
1533
1534 #ifdef CONFIG_HUGETLB_PAGE
1535 /* This function walks within one hugetlb entry in the single call */
1536 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1537                                  unsigned long addr, unsigned long end,
1538                                  struct mm_walk *walk)
1539 {
1540         struct pagemapread *pm = walk->private;
1541         struct vm_area_struct *vma = walk->vma;
1542         u64 flags = 0, frame = 0;
1543         int err = 0;
1544         pte_t pte;
1545
1546         if (vma->vm_flags & VM_SOFTDIRTY)
1547                 flags |= PM_SOFT_DIRTY;
1548
1549         pte = huge_ptep_get(ptep);
1550         if (pte_present(pte)) {
1551                 struct page *page = pte_page(pte);
1552
1553                 if (!PageAnon(page))
1554                         flags |= PM_FILE;
1555
1556                 if (page_mapcount(page) == 1)
1557                         flags |= PM_MMAP_EXCLUSIVE;
1558
1559                 flags |= PM_PRESENT;
1560                 if (pm->show_pfn)
1561                         frame = pte_pfn(pte) +
1562                                 ((addr & ~hmask) >> PAGE_SHIFT);
1563         }
1564
1565         for (; addr != end; addr += PAGE_SIZE) {
1566                 pagemap_entry_t pme = make_pme(frame, flags);
1567
1568                 err = add_to_pagemap(addr, &pme, pm);
1569                 if (err)
1570                         return err;
1571                 if (pm->show_pfn && (flags & PM_PRESENT))
1572                         frame++;
1573         }
1574
1575         cond_resched();
1576
1577         return err;
1578 }
1579 #else
1580 #define pagemap_hugetlb_range   NULL
1581 #endif /* HUGETLB_PAGE */
1582
1583 static const struct mm_walk_ops pagemap_ops = {
1584         .pmd_entry      = pagemap_pmd_range,
1585         .pte_hole       = pagemap_pte_hole,
1586         .hugetlb_entry  = pagemap_hugetlb_range,
1587 };
1588
1589 /*
1590  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1591  *
1592  * For each page in the address space, this file contains one 64-bit entry
1593  * consisting of the following:
1594  *
1595  * Bits 0-54  page frame number (PFN) if present
1596  * Bits 0-4   swap type if swapped
1597  * Bits 5-54  swap offset if swapped
1598  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1599  * Bit  56    page exclusively mapped
1600  * Bit  57    pte is uffd-wp write-protected
1601  * Bits 58-60 zero
1602  * Bit  61    page is file-page or shared-anon
1603  * Bit  62    page swapped
1604  * Bit  63    page present
1605  *
1606  * If the page is not present but in swap, then the PFN contains an
1607  * encoding of the swap file number and the page's offset into the
1608  * swap. Unmapped pages return a null PFN. This allows determining
1609  * precisely which pages are mapped (or in swap) and comparing mapped
1610  * pages between processes.
1611  *
1612  * Efficient users of this interface will use /proc/pid/maps to
1613  * determine which areas of memory are actually mapped and llseek to
1614  * skip over unmapped regions.
1615  */
1616 static ssize_t pagemap_read(struct file *file, char __user *buf,
1617                             size_t count, loff_t *ppos)
1618 {
1619         struct mm_struct *mm = file->private_data;
1620         struct pagemapread pm;
1621         unsigned long src;
1622         unsigned long svpfn;
1623         unsigned long start_vaddr;
1624         unsigned long end_vaddr;
1625         int ret = 0, copied = 0;
1626
1627         if (!mm || !mmget_not_zero(mm))
1628                 goto out;
1629
1630         ret = -EINVAL;
1631         /* file position must be aligned */
1632         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1633                 goto out_mm;
1634
1635         ret = 0;
1636         if (!count)
1637                 goto out_mm;
1638
1639         /* do not disclose physical addresses: attack vector */
1640         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1641
1642         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1643         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1644         ret = -ENOMEM;
1645         if (!pm.buffer)
1646                 goto out_mm;
1647
1648         src = *ppos;
1649         svpfn = src / PM_ENTRY_BYTES;
1650         end_vaddr = mm->task_size;
1651
1652         /* watch out for wraparound */
1653         start_vaddr = end_vaddr;
1654         if (svpfn <= (ULONG_MAX >> PAGE_SHIFT))
1655                 start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
1656
1657         /* Ensure the address is inside the task */
1658         if (start_vaddr > mm->task_size)
1659                 start_vaddr = end_vaddr;
1660
1661         /*
1662          * The odds are that this will stop walking way
1663          * before end_vaddr, because the length of the
1664          * user buffer is tracked in "pm", and the walk
1665          * will stop when we hit the end of the buffer.
1666          */
1667         ret = 0;
1668         while (count && (start_vaddr < end_vaddr)) {
1669                 int len;
1670                 unsigned long end;
1671
1672                 pm.pos = 0;
1673                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1674                 /* overflow ? */
1675                 if (end < start_vaddr || end > end_vaddr)
1676                         end = end_vaddr;
1677                 ret = mmap_read_lock_killable(mm);
1678                 if (ret)
1679                         goto out_free;
1680                 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1681                 mmap_read_unlock(mm);
1682                 start_vaddr = end;
1683
1684                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1685                 if (copy_to_user(buf, pm.buffer, len)) {
1686                         ret = -EFAULT;
1687                         goto out_free;
1688                 }
1689                 copied += len;
1690                 buf += len;
1691                 count -= len;
1692         }
1693         *ppos += copied;
1694         if (!ret || ret == PM_END_OF_BUFFER)
1695                 ret = copied;
1696
1697 out_free:
1698         kfree(pm.buffer);
1699 out_mm:
1700         mmput(mm);
1701 out:
1702         return ret;
1703 }
1704
1705 static int pagemap_open(struct inode *inode, struct file *file)
1706 {
1707         struct mm_struct *mm;
1708
1709         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1710         if (IS_ERR(mm))
1711                 return PTR_ERR(mm);
1712         file->private_data = mm;
1713         return 0;
1714 }
1715
1716 static int pagemap_release(struct inode *inode, struct file *file)
1717 {
1718         struct mm_struct *mm = file->private_data;
1719
1720         if (mm)
1721                 mmdrop(mm);
1722         return 0;
1723 }
1724
1725 const struct file_operations proc_pagemap_operations = {
1726         .llseek         = mem_lseek, /* borrow this */
1727         .read           = pagemap_read,
1728         .open           = pagemap_open,
1729         .release        = pagemap_release,
1730 };
1731 #endif /* CONFIG_PROC_PAGE_MONITOR */
1732
1733 #ifdef CONFIG_NUMA
1734
1735 struct numa_maps {
1736         unsigned long pages;
1737         unsigned long anon;
1738         unsigned long active;
1739         unsigned long writeback;
1740         unsigned long mapcount_max;
1741         unsigned long dirty;
1742         unsigned long swapcache;
1743         unsigned long node[MAX_NUMNODES];
1744 };
1745
1746 struct numa_maps_private {
1747         struct proc_maps_private proc_maps;
1748         struct numa_maps md;
1749 };
1750
1751 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1752                         unsigned long nr_pages)
1753 {
1754         int count = page_mapcount(page);
1755
1756         md->pages += nr_pages;
1757         if (pte_dirty || PageDirty(page))
1758                 md->dirty += nr_pages;
1759
1760         if (PageSwapCache(page))
1761                 md->swapcache += nr_pages;
1762
1763         if (PageActive(page) || PageUnevictable(page))
1764                 md->active += nr_pages;
1765
1766         if (PageWriteback(page))
1767                 md->writeback += nr_pages;
1768
1769         if (PageAnon(page))
1770                 md->anon += nr_pages;
1771
1772         if (count > md->mapcount_max)
1773                 md->mapcount_max = count;
1774
1775         md->node[page_to_nid(page)] += nr_pages;
1776 }
1777
1778 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1779                 unsigned long addr)
1780 {
1781         struct page *page;
1782         int nid;
1783
1784         if (!pte_present(pte))
1785                 return NULL;
1786
1787         page = vm_normal_page(vma, addr, pte);
1788         if (!page)
1789                 return NULL;
1790
1791         if (PageReserved(page))
1792                 return NULL;
1793
1794         nid = page_to_nid(page);
1795         if (!node_isset(nid, node_states[N_MEMORY]))
1796                 return NULL;
1797
1798         return page;
1799 }
1800
1801 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1802 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1803                                               struct vm_area_struct *vma,
1804                                               unsigned long addr)
1805 {
1806         struct page *page;
1807         int nid;
1808
1809         if (!pmd_present(pmd))
1810                 return NULL;
1811
1812         page = vm_normal_page_pmd(vma, addr, pmd);
1813         if (!page)
1814                 return NULL;
1815
1816         if (PageReserved(page))
1817                 return NULL;
1818
1819         nid = page_to_nid(page);
1820         if (!node_isset(nid, node_states[N_MEMORY]))
1821                 return NULL;
1822
1823         return page;
1824 }
1825 #endif
1826
1827 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1828                 unsigned long end, struct mm_walk *walk)
1829 {
1830         struct numa_maps *md = walk->private;
1831         struct vm_area_struct *vma = walk->vma;
1832         spinlock_t *ptl;
1833         pte_t *orig_pte;
1834         pte_t *pte;
1835
1836 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1837         ptl = pmd_trans_huge_lock(pmd, vma);
1838         if (ptl) {
1839                 struct page *page;
1840
1841                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1842                 if (page)
1843                         gather_stats(page, md, pmd_dirty(*pmd),
1844                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1845                 spin_unlock(ptl);
1846                 return 0;
1847         }
1848
1849         if (pmd_trans_unstable(pmd))
1850                 return 0;
1851 #endif
1852         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1853         do {
1854                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1855                 if (!page)
1856                         continue;
1857                 gather_stats(page, md, pte_dirty(*pte), 1);
1858
1859         } while (pte++, addr += PAGE_SIZE, addr != end);
1860         pte_unmap_unlock(orig_pte, ptl);
1861         cond_resched();
1862         return 0;
1863 }
1864 #ifdef CONFIG_HUGETLB_PAGE
1865 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1866                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1867 {
1868         pte_t huge_pte = huge_ptep_get(pte);
1869         struct numa_maps *md;
1870         struct page *page;
1871
1872         if (!pte_present(huge_pte))
1873                 return 0;
1874
1875         page = pte_page(huge_pte);
1876         if (!page)
1877                 return 0;
1878
1879         md = walk->private;
1880         gather_stats(page, md, pte_dirty(huge_pte), 1);
1881         return 0;
1882 }
1883
1884 #else
1885 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1886                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1887 {
1888         return 0;
1889 }
1890 #endif
1891
1892 static const struct mm_walk_ops show_numa_ops = {
1893         .hugetlb_entry = gather_hugetlb_stats,
1894         .pmd_entry = gather_pte_stats,
1895 };
1896
1897 /*
1898  * Display pages allocated per node and memory policy via /proc.
1899  */
1900 static int show_numa_map(struct seq_file *m, void *v)
1901 {
1902         struct numa_maps_private *numa_priv = m->private;
1903         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1904         struct vm_area_struct *vma = v;
1905         struct numa_maps *md = &numa_priv->md;
1906         struct file *file = vma->vm_file;
1907         struct mm_struct *mm = vma->vm_mm;
1908         struct mempolicy *pol;
1909         char buffer[64];
1910         int nid;
1911
1912         if (!mm)
1913                 return 0;
1914
1915         /* Ensure we start with an empty set of numa_maps statistics. */
1916         memset(md, 0, sizeof(*md));
1917
1918         pol = __get_vma_policy(vma, vma->vm_start);
1919         if (pol) {
1920                 mpol_to_str(buffer, sizeof(buffer), pol);
1921                 mpol_cond_put(pol);
1922         } else {
1923                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1924         }
1925
1926         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1927
1928         if (file) {
1929                 seq_puts(m, " file=");
1930                 seq_file_path(m, file, "\n\t= ");
1931         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1932                 seq_puts(m, " heap");
1933         } else if (is_stack(vma)) {
1934                 seq_puts(m, " stack");
1935         }
1936
1937         if (is_vm_hugetlb_page(vma))
1938                 seq_puts(m, " huge");
1939
1940         /* mmap_lock is held by m_start */
1941         walk_page_vma(vma, &show_numa_ops, md);
1942
1943         if (!md->pages)
1944                 goto out;
1945
1946         if (md->anon)
1947                 seq_printf(m, " anon=%lu", md->anon);
1948
1949         if (md->dirty)
1950                 seq_printf(m, " dirty=%lu", md->dirty);
1951
1952         if (md->pages != md->anon && md->pages != md->dirty)
1953                 seq_printf(m, " mapped=%lu", md->pages);
1954
1955         if (md->mapcount_max > 1)
1956                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1957
1958         if (md->swapcache)
1959                 seq_printf(m, " swapcache=%lu", md->swapcache);
1960
1961         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1962                 seq_printf(m, " active=%lu", md->active);
1963
1964         if (md->writeback)
1965                 seq_printf(m, " writeback=%lu", md->writeback);
1966
1967         for_each_node_state(nid, N_MEMORY)
1968                 if (md->node[nid])
1969                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1970
1971         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1972 out:
1973         seq_putc(m, '\n');
1974         return 0;
1975 }
1976
1977 static const struct seq_operations proc_pid_numa_maps_op = {
1978         .start  = m_start,
1979         .next   = m_next,
1980         .stop   = m_stop,
1981         .show   = show_numa_map,
1982 };
1983
1984 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1985 {
1986         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
1987                                 sizeof(struct numa_maps_private));
1988 }
1989
1990 const struct file_operations proc_pid_numa_maps_operations = {
1991         .open           = pid_numa_maps_open,
1992         .read           = seq_read,
1993         .llseek         = seq_lseek,
1994         .release        = proc_map_release,
1995 };
1996
1997 #endif /* CONFIG_NUMA */