fs/proc/task_mmu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/pagewalk.h>
   3 #include <linux/mm_inline.h>
   4 #include <linux/hugetlb.h>
   5 #include <linux/huge_mm.h>
   6 #include <linux/mount.h>
   7 #include <linux/seq_file.h>
   8 #include <linux/highmem.h>
   9 #include <linux/ptrace.h>
  10 #include <linux/slab.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/mempolicy.h>
  13 #include <linux/rmap.h>
  14 #include <linux/swap.h>
  15 #include <linux/sched/mm.h>
  16 #include <linux/swapops.h>
  17 #include <linux/mmu_notifier.h>
  18 #include <linux/page_idle.h>
  19 #include <linux/shmem_fs.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/pkeys.h>
  22
  23 #include <asm/elf.h>
  24 #include <asm/tlb.h>
  25 #include <asm/tlbflush.h>
  26 #include "internal.h"
  27
  28 #define SEQ_PUT_DEC(str, val) \
  29                 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
  30 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 struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
 127                                                 loff_t *ppos)
 128 {
 129         struct vm_area_struct *vma = vma_next(&priv->iter);
 130
 131         if (vma) {
 132                 *ppos = vma->vm_start;
 133         } else {
 134                 *ppos = -2UL;
 135                 vma = get_gate_vma(priv->mm);
 136         }
 137
 138         return vma;
 139 }
 140
 141 static void *m_start(struct seq_file *m, loff_t *ppos)
 142 {
 143         struct proc_maps_private *priv = m->private;
 144         unsigned long last_addr = *ppos;
 145         struct mm_struct *mm;
 146
 147         /* See m_next(). Zero at the start or after lseek. */
 148         if (last_addr == -1UL)
 149                 return NULL;
 150
 151         priv->task = get_proc_task(priv->inode);
 152         if (!priv->task)
 153                 return ERR_PTR(-ESRCH);
 154
 155         mm = priv->mm;
 156         if (!mm || !mmget_not_zero(mm)) {
 157                 put_task_struct(priv->task);
 158                 priv->task = NULL;
 159                 return NULL;
 160         }
 161
 162         if (mmap_read_lock_killable(mm)) {
 163                 mmput(mm);
 164                 put_task_struct(priv->task);
 165                 priv->task = NULL;
 166                 return ERR_PTR(-EINTR);
 167         }
 168
 169         vma_iter_init(&priv->iter, mm, last_addr);
 170         hold_task_mempolicy(priv);
 171         if (last_addr == -2UL)
 172                 return get_gate_vma(mm);
 173
 174         return proc_get_vma(priv, ppos);
 175 }
 176
 177 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
 178 {
 179         if (*ppos == -2UL) {
 180                 *ppos = -1UL;
 181                 return NULL;
 182         }
 183         return proc_get_vma(m->private, ppos);
 184 }
 185
 186 static void m_stop(struct seq_file *m, void *v)
 187 {
 188         struct proc_maps_private *priv = m->private;
 189         struct mm_struct *mm = priv->mm;
 190
 191         if (!priv->task)
 192                 return;
 193
 194         release_task_mempolicy(priv);
 195         mmap_read_unlock(mm);
 196         mmput(mm);
 197         put_task_struct(priv->task);
 198         priv->task = NULL;
 199 }
 200
 201 static int proc_maps_open(struct inode *inode, struct file *file,
 202                         const struct seq_operations *ops, int psize)
 203 {
 204         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
 205
 206         if (!priv)
 207                 return -ENOMEM;
 208
 209         priv->inode = inode;
 210         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 211         if (IS_ERR(priv->mm)) {
 212                 int err = PTR_ERR(priv->mm);
 213
 214                 seq_release_private(inode, file);
 215                 return err;
 216         }
 217
 218         return 0;
 219 }
 220
 221 static int proc_map_release(struct inode *inode, struct file *file)
 222 {
 223         struct seq_file *seq = file->private_data;
 224         struct proc_maps_private *priv = seq->private;
 225
 226         if (priv->mm)
 227                 mmdrop(priv->mm);
 228
 229         return seq_release_private(inode, file);
 230 }
 231
 232 static int do_maps_open(struct inode *inode, struct file *file,
 233                         const struct seq_operations *ops)
 234 {
 235         return proc_maps_open(inode, file, ops,
 236                                 sizeof(struct proc_maps_private));
 237 }
 238
 239 /*
 240  * Indicate if the VMA is a stack for the given task; for
 241  * /proc/PID/maps that is the stack of the main task.
 242  */
 243 static int is_stack(struct vm_area_struct *vma)
 244 {
 245         /*
 246          * We make no effort to guess what a given thread considers to be
 247          * its "stack".  It's not even well-defined for programs written
 248          * languages like Go.
 249          */
 250         return vma->vm_start <= vma->vm_mm->start_stack &&
 251                 vma->vm_end >= vma->vm_mm->start_stack;
 252 }
 253
 254 static void show_vma_header_prefix(struct seq_file *m,
 255                                    unsigned long start, unsigned long end,
 256                                    vm_flags_t flags, unsigned long long pgoff,
 257                                    dev_t dev, unsigned long ino)
 258 {
 259         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 260         seq_put_hex_ll(m, NULL, start, 8);
 261         seq_put_hex_ll(m, "-", end, 8);
 262         seq_putc(m, ' ');
 263         seq_putc(m, flags & VM_READ ? 'r' : '-');
 264         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
 265         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
 266         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
 267         seq_put_hex_ll(m, " ", pgoff, 8);
 268         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
 269         seq_put_hex_ll(m, ":", MINOR(dev), 2);
 270         seq_put_decimal_ull(m, " ", ino);
 271         seq_putc(m, ' ');
 272 }
 273
 274 static void
 275 show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 276 {
 277         struct anon_vma_name *anon_name = NULL;
 278         struct mm_struct *mm = vma->vm_mm;
 279         struct file *file = vma->vm_file;
 280         vm_flags_t flags = vma->vm_flags;
 281         unsigned long ino = 0;
 282         unsigned long long pgoff = 0;
 283         unsigned long start, end;
 284         dev_t dev = 0;
 285         const char *name = NULL;
 286
 287         if (file) {
 288                 struct inode *inode = file_inode(vma->vm_file);
 289                 dev = inode->i_sb->s_dev;
 290                 ino = inode->i_ino;
 291                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 292         }
 293
 294         start = vma->vm_start;
 295         end = vma->vm_end;
 296         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
 297         if (mm)
 298                 anon_name = anon_vma_name(vma);
 299
 300         /*
 301          * Print the dentry name for named mappings, and a
 302          * special [heap] marker for the heap:
 303          */
 304         if (file) {
 305                 seq_pad(m, ' ');
 306                 /*
 307                  * If user named this anon shared memory via
 308                  * prctl(PR_SET_VMA ..., use the provided name.
 309                  */
 310                 if (anon_name)
 311                         seq_printf(m, "[anon_shmem:%s]", anon_name->name);
 312                 else
 313                         seq_file_path(m, file, "\n");
 314                 goto done;
 315         }
 316
 317         if (vma->vm_ops && vma->vm_ops->name) {
 318                 name = vma->vm_ops->name(vma);
 319                 if (name)
 320                         goto done;
 321         }
 322
 323         name = arch_vma_name(vma);
 324         if (!name) {
 325                 if (!mm) {
 326                         name = "[vdso]";
 327                         goto done;
 328                 }
 329
 330                 if (vma->vm_start <= mm->brk &&
 331                     vma->vm_end >= mm->start_brk) {
 332                         name = "[heap]";
 333                         goto done;
 334                 }
 335
 336                 if (is_stack(vma)) {
 337                         name = "[stack]";
 338                         goto done;
 339                 }
 340
 341                 if (anon_name) {
 342                         seq_pad(m, ' ');
 343                         seq_printf(m, "[anon:%s]", anon_name->name);
 344                 }
 345         }
 346
 347 done:
 348         if (name) {
 349                 seq_pad(m, ' ');
 350                 seq_puts(m, name);
 351         }
 352         seq_putc(m, '\n');
 353 }
 354
 355 static int show_map(struct seq_file *m, void *v)
 356 {
 357         show_map_vma(m, v);
 358         return 0;
 359 }
 360
 361 static const struct seq_operations proc_pid_maps_op = {
 362         .start  = m_start,
 363         .next   = m_next,
 364         .stop   = m_stop,
 365         .show   = show_map
 366 };
 367
 368 static int pid_maps_open(struct inode *inode, struct file *file)
 369 {
 370         return do_maps_open(inode, file, &proc_pid_maps_op);
 371 }
 372
 373 const struct file_operations proc_pid_maps_operations = {
 374         .open           = pid_maps_open,
 375         .read           = seq_read,
 376         .llseek         = seq_lseek,
 377         .release        = proc_map_release,
 378 };
 379
 380 /*
 381  * Proportional Set Size(PSS): my share of RSS.
 382  *
 383  * PSS of a process is the count of pages it has in memory, where each
 384  * page is divided by the number of processes sharing it.  So if a
 385  * process has 1000 pages all to itself, and 1000 shared with one other
 386  * process, its PSS will be 1500.
 387  *
 388  * To keep (accumulated) division errors low, we adopt a 64bit
 389  * fixed-point pss counter to minimize division errors. So (pss >>
 390  * PSS_SHIFT) would be the real byte count.
 391  *
 392  * A shift of 12 before division means (assuming 4K page size):
 393  *      - 1M 3-user-pages add up to 8KB errors;
 394  *      - supports mapcount up to 2^24, or 16M;
 395  *      - supports PSS up to 2^52 bytes, or 4PB.
 396  */
 397 #define PSS_SHIFT 12
 398
 399 #ifdef CONFIG_PROC_PAGE_MONITOR
 400 struct mem_size_stats {
 401         unsigned long resident;
 402         unsigned long shared_clean;
 403         unsigned long shared_dirty;
 404         unsigned long private_clean;
 405         unsigned long private_dirty;
 406         unsigned long referenced;
 407         unsigned long anonymous;
 408         unsigned long lazyfree;
 409         unsigned long anonymous_thp;
 410         unsigned long shmem_thp;
 411         unsigned long file_thp;
 412         unsigned long swap;
 413         unsigned long shared_hugetlb;
 414         unsigned long private_hugetlb;
 415         u64 pss;
 416         u64 pss_anon;
 417         u64 pss_file;
 418         u64 pss_shmem;
 419         u64 pss_dirty;
 420         u64 pss_locked;
 421         u64 swap_pss;
 422 };
 423
 424 static void smaps_page_accumulate(struct mem_size_stats *mss,
 425                 struct page *page, unsigned long size, unsigned long pss,
 426                 bool dirty, bool locked, bool private)
 427 {
 428         mss->pss += pss;
 429
 430         if (PageAnon(page))
 431                 mss->pss_anon += pss;
 432         else if (PageSwapBacked(page))
 433                 mss->pss_shmem += pss;
 434         else
 435                 mss->pss_file += pss;
 436
 437         if (locked)
 438                 mss->pss_locked += pss;
 439
 440         if (dirty || PageDirty(page)) {
 441                 mss->pss_dirty += pss;
 442                 if (private)
 443                         mss->private_dirty += size;
 444                 else
 445                         mss->shared_dirty += size;
 446         } else {
 447                 if (private)
 448                         mss->private_clean += size;
 449                 else
 450                         mss->shared_clean += size;
 451         }
 452 }
 453
 454 static void smaps_account(struct mem_size_stats *mss, struct page *page,
 455                 bool compound, bool young, bool dirty, bool locked,
 456                 bool migration)
 457 {
 458         int i, nr = compound ? compound_nr(page) : 1;
 459         unsigned long size = nr * PAGE_SIZE;
 460
 461         /*
 462          * First accumulate quantities that depend only on |size| and the type
 463          * of the compound page.
 464          */
 465         if (PageAnon(page)) {
 466                 mss->anonymous += size;
 467                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
 468                         mss->lazyfree += size;
 469         }
 470
 471         mss->resident += size;
 472         /* Accumulate the size in pages that have been accessed. */
 473         if (young || page_is_young(page) || PageReferenced(page))
 474                 mss->referenced += size;
 475
 476         /*
 477          * Then accumulate quantities that may depend on sharing, or that may
 478          * differ page-by-page.
 479          *
 480          * page_count(page) == 1 guarantees the page is mapped exactly once.
 481          * If any subpage of the compound page mapped with PTE it would elevate
 482          * page_count().
 483          *
 484          * The page_mapcount() is called to get a snapshot of the mapcount.
 485          * Without holding the page lock this snapshot can be slightly wrong as
 486          * we cannot always read the mapcount atomically.  It is not safe to
 487          * call page_mapcount() even with PTL held if the page is not mapped,
 488          * especially for migration entries.  Treat regular migration entries
 489          * as mapcount == 1.
 490          */
 491         if ((page_count(page) == 1) || migration) {
 492                 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
 493                         locked, true);
 494                 return;
 495         }
 496         for (i = 0; i < nr; i++, page++) {
 497                 int mapcount = page_mapcount(page);
 498                 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
 499                 if (mapcount >= 2)
 500                         pss /= mapcount;
 501                 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
 502                                       mapcount < 2);
 503         }
 504 }
 505
 506 #ifdef CONFIG_SHMEM
 507 static int smaps_pte_hole(unsigned long addr, unsigned long end,
 508                           __always_unused int depth, struct mm_walk *walk)
 509 {
 510         struct mem_size_stats *mss = walk->private;
 511         struct vm_area_struct *vma = walk->vma;
 512
 513         mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
 514                                               linear_page_index(vma, addr),
 515                                               linear_page_index(vma, end));
 516
 517         return 0;
 518 }
 519 #else
 520 #define smaps_pte_hole          NULL
 521 #endif /* CONFIG_SHMEM */
 522
 523 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
 524 {
 525 #ifdef CONFIG_SHMEM
 526         if (walk->ops->pte_hole) {
 527                 /* depth is not used */
 528                 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
 529         }
 530 #endif
 531 }
 532
 533 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 534                 struct mm_walk *walk)
 535 {
 536         struct mem_size_stats *mss = walk->private;
 537         struct vm_area_struct *vma = walk->vma;
 538         bool locked = !!(vma->vm_flags & VM_LOCKED);
 539         struct page *page = NULL;
 540         bool migration = false, young = false, dirty = false;
 541         pte_t ptent = ptep_get(pte);
 542
 543         if (pte_present(ptent)) {
 544                 page = vm_normal_page(vma, addr, ptent);
 545                 young = pte_young(ptent);
 546                 dirty = pte_dirty(ptent);
 547         } else if (is_swap_pte(ptent)) {
 548                 swp_entry_t swpent = pte_to_swp_entry(ptent);
 549
 550                 if (!non_swap_entry(swpent)) {
 551                         int mapcount;
 552
 553                         mss->swap += PAGE_SIZE;
 554                         mapcount = swp_swapcount(swpent);
 555                         if (mapcount >= 2) {
 556                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
 557
 558                                 do_div(pss_delta, mapcount);
 559                                 mss->swap_pss += pss_delta;
 560                         } else {
 561                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
 562                         }
 563                 } else if (is_pfn_swap_entry(swpent)) {
 564                         if (is_migration_entry(swpent))
 565                                 migration = true;
 566                         page = pfn_swap_entry_to_page(swpent);
 567                 }
 568         } else {
 569                 smaps_pte_hole_lookup(addr, walk);
 570                 return;
 571         }
 572
 573         if (!page)
 574                 return;
 575
 576         smaps_account(mss, page, false, young, dirty, locked, migration);
 577 }
 578
 579 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 580 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 581                 struct mm_walk *walk)
 582 {
 583         struct mem_size_stats *mss = walk->private;
 584         struct vm_area_struct *vma = walk->vma;
 585         bool locked = !!(vma->vm_flags & VM_LOCKED);
 586         struct page *page = NULL;
 587         bool migration = false;
 588
 589         if (pmd_present(*pmd)) {
 590                 /* FOLL_DUMP will return -EFAULT on huge zero page */
 591                 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
 592         } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
 593                 swp_entry_t entry = pmd_to_swp_entry(*pmd);
 594
 595                 if (is_migration_entry(entry)) {
 596                         migration = true;
 597                         page = pfn_swap_entry_to_page(entry);
 598                 }
 599         }
 600         if (IS_ERR_OR_NULL(page))
 601                 return;
 602         if (PageAnon(page))
 603                 mss->anonymous_thp += HPAGE_PMD_SIZE;
 604         else if (PageSwapBacked(page))
 605                 mss->shmem_thp += HPAGE_PMD_SIZE;
 606         else if (is_zone_device_page(page))
 607                 /* pass */;
 608         else
 609                 mss->file_thp += HPAGE_PMD_SIZE;
 610
 611         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
 612                       locked, migration);
 613 }
 614 #else
 615 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 616                 struct mm_walk *walk)
 617 {
 618 }
 619 #endif
 620
 621 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 622                            struct mm_walk *walk)
 623 {
 624         struct vm_area_struct *vma = walk->vma;
 625         pte_t *pte;
 626         spinlock_t *ptl;
 627
 628         ptl = pmd_trans_huge_lock(pmd, vma);
 629         if (ptl) {
 630                 smaps_pmd_entry(pmd, addr, walk);
 631                 spin_unlock(ptl);
 632                 goto out;
 633         }
 634
 635         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 636         if (!pte) {
 637                 walk->action = ACTION_AGAIN;
 638                 return 0;
 639         }
 640         for (; addr != end; pte++, addr += PAGE_SIZE)
 641                 smaps_pte_entry(pte, addr, walk);
 642         pte_unmap_unlock(pte - 1, ptl);
 643 out:
 644         cond_resched();
 645         return 0;
 646 }
 647
 648 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 649 {
 650         /*
 651          * Don't forget to update Documentation/ on changes.
 652          */
 653         static const char mnemonics[BITS_PER_LONG][2] = {
 654                 /*
 655                  * In case if we meet a flag we don't know about.
 656                  */
 657                 [0 ... (BITS_PER_LONG-1)] = "??",
 658
 659                 [ilog2(VM_READ)]        = "rd",
 660                 [ilog2(VM_WRITE)]       = "wr",
 661                 [ilog2(VM_EXEC)]        = "ex",
 662                 [ilog2(VM_SHARED)]      = "sh",
 663                 [ilog2(VM_MAYREAD)]     = "mr",
 664                 [ilog2(VM_MAYWRITE)]    = "mw",
 665                 [ilog2(VM_MAYEXEC)]     = "me",
 666                 [ilog2(VM_MAYSHARE)]    = "ms",
 667                 [ilog2(VM_GROWSDOWN)]   = "gd",
 668                 [ilog2(VM_PFNMAP)]      = "pf",
 669                 [ilog2(VM_LOCKED)]      = "lo",
 670                 [ilog2(VM_IO)]          = "io",
 671                 [ilog2(VM_SEQ_READ)]    = "sr",
 672                 [ilog2(VM_RAND_READ)]   = "rr",
 673                 [ilog2(VM_DONTCOPY)]    = "dc",
 674                 [ilog2(VM_DONTEXPAND)]  = "de",
 675                 [ilog2(VM_LOCKONFAULT)] = "lf",
 676                 [ilog2(VM_ACCOUNT)]     = "ac",
 677                 [ilog2(VM_NORESERVE)]   = "nr",
 678                 [ilog2(VM_HUGETLB)]     = "ht",
 679                 [ilog2(VM_SYNC)]        = "sf",
 680                 [ilog2(VM_ARCH_1)]      = "ar",
 681                 [ilog2(VM_WIPEONFORK)]  = "wf",
 682                 [ilog2(VM_DONTDUMP)]    = "dd",
 683 #ifdef CONFIG_ARM64_BTI
 684                 [ilog2(VM_ARM64_BTI)]   = "bt",
 685 #endif
 686 #ifdef CONFIG_MEM_SOFT_DIRTY
 687                 [ilog2(VM_SOFTDIRTY)]   = "sd",
 688 #endif
 689                 [ilog2(VM_MIXEDMAP)]    = "mm",
 690                 [ilog2(VM_HUGEPAGE)]    = "hg",
 691                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
 692                 [ilog2(VM_MERGEABLE)]   = "mg",
 693                 [ilog2(VM_UFFD_MISSING)]= "um",
 694                 [ilog2(VM_UFFD_WP)]     = "uw",
 695 #ifdef CONFIG_ARM64_MTE
 696                 [ilog2(VM_MTE)]         = "mt",
 697                 [ilog2(VM_MTE_ALLOWED)] = "",
 698 #endif
 699 #ifdef CONFIG_ARCH_HAS_PKEYS
 700                 /* These come out via ProtectionKey: */
 701                 [ilog2(VM_PKEY_BIT0)]   = "",
 702                 [ilog2(VM_PKEY_BIT1)]   = "",
 703                 [ilog2(VM_PKEY_BIT2)]   = "",
 704                 [ilog2(VM_PKEY_BIT3)]   = "",
 705 #if VM_PKEY_BIT4
 706                 [ilog2(VM_PKEY_BIT4)]   = "",
 707 #endif
 708 #endif /* CONFIG_ARCH_HAS_PKEYS */
 709 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
 710                 [ilog2(VM_UFFD_MINOR)]  = "ui",
 711 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
 712         };
 713         size_t i;
 714
 715         seq_puts(m, "VmFlags: ");
 716         for (i = 0; i < BITS_PER_LONG; i++) {
 717                 if (!mnemonics[i][0])
 718                         continue;
 719                 if (vma->vm_flags & (1UL << i)) {
 720                         seq_putc(m, mnemonics[i][0]);
 721                         seq_putc(m, mnemonics[i][1]);
 722                         seq_putc(m, ' ');
 723                 }
 724         }
 725         seq_putc(m, '\n');
 726 }
 727
 728 #ifdef CONFIG_HUGETLB_PAGE
 729 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 730                                  unsigned long addr, unsigned long end,
 731                                  struct mm_walk *walk)
 732 {
 733         struct mem_size_stats *mss = walk->private;
 734         struct vm_area_struct *vma = walk->vma;
 735         struct page *page = NULL;
 736         pte_t ptent = ptep_get(pte);
 737
 738         if (pte_present(ptent)) {
 739                 page = vm_normal_page(vma, addr, ptent);
 740         } else if (is_swap_pte(ptent)) {
 741                 swp_entry_t swpent = pte_to_swp_entry(ptent);
 742
 743                 if (is_pfn_swap_entry(swpent))
 744                         page = pfn_swap_entry_to_page(swpent);
 745         }
 746         if (page) {
 747                 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
 748                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
 749                 else
 750                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
 751         }
 752         return 0;
 753 }
 754 #else
 755 #define smaps_hugetlb_range     NULL
 756 #endif /* HUGETLB_PAGE */
 757
 758 static const struct mm_walk_ops smaps_walk_ops = {
 759         .pmd_entry              = smaps_pte_range,
 760         .hugetlb_entry          = smaps_hugetlb_range,
 761 };
 762
 763 static const struct mm_walk_ops smaps_shmem_walk_ops = {
 764         .pmd_entry              = smaps_pte_range,
 765         .hugetlb_entry          = smaps_hugetlb_range,
 766         .pte_hole               = smaps_pte_hole,
 767 };
 768
 769 /*
 770  * Gather mem stats from @vma with the indicated beginning
 771  * address @start, and keep them in @mss.
 772  *
 773  * Use vm_start of @vma as the beginning address if @start is 0.
 774  */
 775 static void smap_gather_stats(struct vm_area_struct *vma,
 776                 struct mem_size_stats *mss, unsigned long start)
 777 {
 778         const struct mm_walk_ops *ops = &smaps_walk_ops;
 779
 780         /* Invalid start */
 781         if (start >= vma->vm_end)
 782                 return;
 783
 784         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
 785                 /*
 786                  * For shared or readonly shmem mappings we know that all
 787                  * swapped out pages belong to the shmem object, and we can
 788                  * obtain the swap value much more efficiently. For private
 789                  * writable mappings, we might have COW pages that are
 790                  * not affected by the parent swapped out pages of the shmem
 791                  * object, so we have to distinguish them during the page walk.
 792                  * Unless we know that the shmem object (or the part mapped by
 793                  * our VMA) has no swapped out pages at all.
 794                  */
 795                 unsigned long shmem_swapped = shmem_swap_usage(vma);
 796
 797                 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
 798                                         !(vma->vm_flags & VM_WRITE))) {
 799                         mss->swap += shmem_swapped;
 800                 } else {
 801                         ops = &smaps_shmem_walk_ops;
 802                 }
 803         }
 804
 805         /* mmap_lock is held in m_start */
 806         if (!start)
 807                 walk_page_vma(vma, ops, mss);
 808         else
 809                 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
 810 }
 811
 812 #define SEQ_PUT_DEC(str, val) \
 813                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
 814
 815 /* Show the contents common for smaps and smaps_rollup */
 816 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
 817         bool rollup_mode)
 818 {
 819         SEQ_PUT_DEC("Rss:            ", mss->resident);
 820         SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
 821         SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> PSS_SHIFT);
 822         if (rollup_mode) {
 823                 /*
 824                  * These are meaningful only for smaps_rollup, otherwise two of
 825                  * them are zero, and the other one is the same as Pss.
 826                  */
 827                 SEQ_PUT_DEC(" kB\nPss_Anon:       ",
 828                         mss->pss_anon >> PSS_SHIFT);
 829                 SEQ_PUT_DEC(" kB\nPss_File:       ",
 830                         mss->pss_file >> PSS_SHIFT);
 831                 SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
 832                         mss->pss_shmem >> PSS_SHIFT);
 833         }
 834         SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
 835         SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
 836         SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
 837         SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
 838         SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
 839         SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
 840         SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
 841         SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
 842         SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
 843         SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
 844         SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
 845         seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
 846                                   mss->private_hugetlb >> 10, 7);
 847         SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
 848         SEQ_PUT_DEC(" kB\nSwapPss:        ",
 849                                         mss->swap_pss >> PSS_SHIFT);
 850         SEQ_PUT_DEC(" kB\nLocked:         ",
 851                                         mss->pss_locked >> PSS_SHIFT);
 852         seq_puts(m, " kB\n");
 853 }
 854
 855 static int show_smap(struct seq_file *m, void *v)
 856 {
 857         struct vm_area_struct *vma = v;
 858         struct mem_size_stats mss;
 859
 860         memset(&mss, 0, sizeof(mss));
 861
 862         smap_gather_stats(vma, &mss, 0);
 863
 864         show_map_vma(m, vma);
 865
 866         SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
 867         SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
 868         SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
 869         seq_puts(m, " kB\n");
 870
 871         __show_smap(m, &mss, false);
 872
 873         seq_printf(m, "THPeligible:    %d\n",
 874                    hugepage_vma_check(vma, vma->vm_flags, true, false, true));
 875
 876         if (arch_pkeys_enabled())
 877                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
 878         show_smap_vma_flags(m, vma);
 879
 880         return 0;
 881 }
 882
 883 static int show_smaps_rollup(struct seq_file *m, void *v)
 884 {
 885         struct proc_maps_private *priv = m->private;
 886         struct mem_size_stats mss;
 887         struct mm_struct *mm = priv->mm;
 888         struct vm_area_struct *vma;
 889         unsigned long vma_start = 0, last_vma_end = 0;
 890         int ret = 0;
 891         VMA_ITERATOR(vmi, mm, 0);
 892
 893         priv->task = get_proc_task(priv->inode);
 894         if (!priv->task)
 895                 return -ESRCH;
 896
 897         if (!mm || !mmget_not_zero(mm)) {
 898                 ret = -ESRCH;
 899                 goto out_put_task;
 900         }
 901
 902         memset(&mss, 0, sizeof(mss));
 903
 904         ret = mmap_read_lock_killable(mm);
 905         if (ret)
 906                 goto out_put_mm;
 907
 908         hold_task_mempolicy(priv);
 909         vma = vma_next(&vmi);
 910
 911         if (unlikely(!vma))
 912                 goto empty_set;
 913
 914         vma_start = vma->vm_start;
 915         do {
 916                 smap_gather_stats(vma, &mss, 0);
 917                 last_vma_end = vma->vm_end;
 918
 919                 /*
 920                  * Release mmap_lock temporarily if someone wants to
 921                  * access it for write request.
 922                  */
 923                 if (mmap_lock_is_contended(mm)) {
 924                         vma_iter_invalidate(&vmi);
 925                         mmap_read_unlock(mm);
 926                         ret = mmap_read_lock_killable(mm);
 927                         if (ret) {
 928                                 release_task_mempolicy(priv);
 929                                 goto out_put_mm;
 930                         }
 931
 932                         /*
 933                          * After dropping the lock, there are four cases to
 934                          * consider. See the following example for explanation.
 935                          *
 936                          *   +------+------+-----------+
 937                          *   | VMA1 | VMA2 | VMA3      |
 938                          *   +------+------+-----------+
 939                          *   |      |      |           |
 940                          *  4k     8k     16k         400k
 941                          *
 942                          * Suppose we drop the lock after reading VMA2 due to
 943                          * contention, then we get:
 944                          *
 945                          *      last_vma_end = 16k
 946                          *
 947                          * 1) VMA2 is freed, but VMA3 exists:
 948                          *
 949                          *    vma_next(vmi) will return VMA3.
 950                          *    In this case, just continue from VMA3.
 951                          *
 952                          * 2) VMA2 still exists:
 953                          *
 954                          *    vma_next(vmi) will return VMA3.
 955                          *    In this case, just continue from VMA3.
 956                          *
 957                          * 3) No more VMAs can be found:
 958                          *
 959                          *    vma_next(vmi) will return NULL.
 960                          *    No more things to do, just break.
 961                          *
 962                          * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
 963                          *
 964                          *    vma_next(vmi) will return VMA' whose range
 965                          *    contains last_vma_end.
 966                          *    Iterate VMA' from last_vma_end.
 967                          */
 968                         vma = vma_next(&vmi);
 969                         /* Case 3 above */
 970                         if (!vma)
 971                                 break;
 972
 973                         /* Case 1 and 2 above */
 974                         if (vma->vm_start >= last_vma_end)
 975                                 continue;
 976
 977                         /* Case 4 above */
 978                         if (vma->vm_end > last_vma_end)
 979                                 smap_gather_stats(vma, &mss, last_vma_end);
 980                 }
 981         } for_each_vma(vmi, vma);
 982
 983 empty_set:
 984         show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
 985         seq_pad(m, ' ');
 986         seq_puts(m, "[rollup]\n");
 987
 988         __show_smap(m, &mss, true);
 989
 990         release_task_mempolicy(priv);
 991         mmap_read_unlock(mm);
 992
 993 out_put_mm:
 994         mmput(mm);
 995 out_put_task:
 996         put_task_struct(priv->task);
 997         priv->task = NULL;
 998
 999         return ret;
1000 }
1001 #undef SEQ_PUT_DEC
1002
1003 static const struct seq_operations proc_pid_smaps_op = {
1004         .start  = m_start,
1005         .next   = m_next,
1006         .stop   = m_stop,
1007         .show   = show_smap
1008 };
1009
1010 static int pid_smaps_open(struct inode *inode, struct file *file)
1011 {
1012         return do_maps_open(inode, file, &proc_pid_smaps_op);
1013 }
1014
1015 static int smaps_rollup_open(struct inode *inode, struct file *file)
1016 {
1017         int ret;
1018         struct proc_maps_private *priv;
1019
1020         priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1021         if (!priv)
1022                 return -ENOMEM;
1023
1024         ret = single_open(file, show_smaps_rollup, priv);
1025         if (ret)
1026                 goto out_free;
1027
1028         priv->inode = inode;
1029         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1030         if (IS_ERR(priv->mm)) {
1031                 ret = PTR_ERR(priv->mm);
1032
1033                 single_release(inode, file);
1034                 goto out_free;
1035         }
1036
1037         return 0;
1038
1039 out_free:
1040         kfree(priv);
1041         return ret;
1042 }
1043
1044 static int smaps_rollup_release(struct inode *inode, struct file *file)
1045 {
1046         struct seq_file *seq = file->private_data;
1047         struct proc_maps_private *priv = seq->private;
1048
1049         if (priv->mm)
1050                 mmdrop(priv->mm);
1051
1052         kfree(priv);
1053         return single_release(inode, file);
1054 }
1055
1056 const struct file_operations proc_pid_smaps_operations = {
1057         .open           = pid_smaps_open,
1058         .read           = seq_read,
1059         .llseek         = seq_lseek,
1060         .release        = proc_map_release,
1061 };
1062
1063 const struct file_operations proc_pid_smaps_rollup_operations = {
1064         .open           = smaps_rollup_open,
1065         .read           = seq_read,
1066         .llseek         = seq_lseek,
1067         .release        = smaps_rollup_release,
1068 };
1069
1070 enum clear_refs_types {
1071         CLEAR_REFS_ALL = 1,
1072         CLEAR_REFS_ANON,
1073         CLEAR_REFS_MAPPED,
1074         CLEAR_REFS_SOFT_DIRTY,
1075         CLEAR_REFS_MM_HIWATER_RSS,
1076         CLEAR_REFS_LAST,
1077 };
1078
1079 struct clear_refs_private {
1080         enum clear_refs_types type;
1081 };
1082
1083 #ifdef CONFIG_MEM_SOFT_DIRTY
1084
1085 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1086 {
1087         struct page *page;
1088
1089         if (!pte_write(pte))
1090                 return false;
1091         if (!is_cow_mapping(vma->vm_flags))
1092                 return false;
1093         if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1094                 return false;
1095         page = vm_normal_page(vma, addr, pte);
1096         if (!page)
1097                 return false;
1098         return page_maybe_dma_pinned(page);
1099 }
1100
1101 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1102                 unsigned long addr, pte_t *pte)
1103 {
1104         /*
1105          * The soft-dirty tracker uses #PF-s to catch writes
1106          * to pages, so write-protect the pte as well. See the
1107          * Documentation/admin-guide/mm/soft-dirty.rst for full description
1108          * of how soft-dirty works.
1109          */
1110         pte_t ptent = ptep_get(pte);
1111
1112         if (pte_present(ptent)) {
1113                 pte_t old_pte;
1114
1115                 if (pte_is_pinned(vma, addr, ptent))
1116                         return;
1117                 old_pte = ptep_modify_prot_start(vma, addr, pte);
1118                 ptent = pte_wrprotect(old_pte);
1119                 ptent = pte_clear_soft_dirty(ptent);
1120                 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1121         } else if (is_swap_pte(ptent)) {
1122                 ptent = pte_swp_clear_soft_dirty(ptent);
1123                 set_pte_at(vma->vm_mm, addr, pte, ptent);
1124         }
1125 }
1126 #else
1127 static inline void clear_soft_dirty(struct vm_area_struct *vma,
1128                 unsigned long addr, pte_t *pte)
1129 {
1130 }
1131 #endif
1132
1133 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1134 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1135                 unsigned long addr, pmd_t *pmdp)
1136 {
1137         pmd_t old, pmd = *pmdp;
1138
1139         if (pmd_present(pmd)) {
1140                 /* See comment in change_huge_pmd() */
1141                 old = pmdp_invalidate(vma, addr, pmdp);
1142                 if (pmd_dirty(old))
1143                         pmd = pmd_mkdirty(pmd);
1144                 if (pmd_young(old))
1145                         pmd = pmd_mkyoung(pmd);
1146
1147                 pmd = pmd_wrprotect(pmd);
1148                 pmd = pmd_clear_soft_dirty(pmd);
1149
1150                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1151         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1152                 pmd = pmd_swp_clear_soft_dirty(pmd);
1153                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1154         }
1155 }
1156 #else
1157 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1158                 unsigned long addr, pmd_t *pmdp)
1159 {
1160 }
1161 #endif
1162
1163 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1164                                 unsigned long end, struct mm_walk *walk)
1165 {
1166         struct clear_refs_private *cp = walk->private;
1167         struct vm_area_struct *vma = walk->vma;
1168         pte_t *pte, ptent;
1169         spinlock_t *ptl;
1170         struct page *page;
1171
1172         ptl = pmd_trans_huge_lock(pmd, vma);
1173         if (ptl) {
1174                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1175                         clear_soft_dirty_pmd(vma, addr, pmd);
1176                         goto out;
1177                 }
1178
1179                 if (!pmd_present(*pmd))
1180                         goto out;
1181
1182                 page = pmd_page(*pmd);
1183
1184                 /* Clear accessed and referenced bits. */
1185                 pmdp_test_and_clear_young(vma, addr, pmd);
1186                 test_and_clear_page_young(page);
1187                 ClearPageReferenced(page);
1188 out:
1189                 spin_unlock(ptl);
1190                 return 0;
1191         }
1192
1193         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1194         if (!pte) {
1195                 walk->action = ACTION_AGAIN;
1196                 return 0;
1197         }
1198         for (; addr != end; pte++, addr += PAGE_SIZE) {
1199                 ptent = ptep_get(pte);
1200
1201                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1202                         clear_soft_dirty(vma, addr, pte);
1203                         continue;
1204                 }
1205
1206                 if (!pte_present(ptent))
1207                         continue;
1208
1209                 page = vm_normal_page(vma, addr, ptent);
1210                 if (!page)
1211                         continue;
1212
1213                 /* Clear accessed and referenced bits. */
1214                 ptep_test_and_clear_young(vma, addr, pte);
1215                 test_and_clear_page_young(page);
1216                 ClearPageReferenced(page);
1217         }
1218         pte_unmap_unlock(pte - 1, ptl);
1219         cond_resched();
1220         return 0;
1221 }
1222
1223 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1224                                 struct mm_walk *walk)
1225 {
1226         struct clear_refs_private *cp = walk->private;
1227         struct vm_area_struct *vma = walk->vma;
1228
1229         if (vma->vm_flags & VM_PFNMAP)
1230                 return 1;
1231
1232         /*
1233          * Writing 1 to /proc/pid/clear_refs affects all pages.
1234          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1235          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1236          * Writing 4 to /proc/pid/clear_refs affects all pages.
1237          */
1238         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1239                 return 1;
1240         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1241                 return 1;
1242         return 0;
1243 }
1244
1245 static const struct mm_walk_ops clear_refs_walk_ops = {
1246         .pmd_entry              = clear_refs_pte_range,
1247         .test_walk              = clear_refs_test_walk,
1248 };
1249
1250 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1251                                 size_t count, loff_t *ppos)
1252 {
1253         struct task_struct *task;
1254         char buffer[PROC_NUMBUF];
1255         struct mm_struct *mm;
1256         struct vm_area_struct *vma;
1257         enum clear_refs_types type;
1258         int itype;
1259         int rv;
1260
1261         memset(buffer, 0, sizeof(buffer));
1262         if (count > sizeof(buffer) - 1)
1263                 count = sizeof(buffer) - 1;
1264         if (copy_from_user(buffer, buf, count))
1265                 return -EFAULT;
1266         rv = kstrtoint(strstrip(buffer), 10, &itype);
1267         if (rv < 0)
1268                 return rv;
1269         type = (enum clear_refs_types)itype;
1270         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1271                 return -EINVAL;
1272
1273         task = get_proc_task(file_inode(file));
1274         if (!task)
1275                 return -ESRCH;
1276         mm = get_task_mm(task);
1277         if (mm) {
1278                 VMA_ITERATOR(vmi, mm, 0);
1279                 struct mmu_notifier_range range;
1280                 struct clear_refs_private cp = {
1281                         .type = type,
1282                 };
1283
1284                 if (mmap_write_lock_killable(mm)) {
1285                         count = -EINTR;
1286                         goto out_mm;
1287                 }
1288                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1289                         /*
1290                          * Writing 5 to /proc/pid/clear_refs resets the peak
1291                          * resident set size to this mm's current rss value.
1292                          */
1293                         reset_mm_hiwater_rss(mm);
1294                         goto out_unlock;
1295                 }
1296
1297                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1298                         for_each_vma(vmi, vma) {
1299                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1300                                         continue;
1301                                 vm_flags_clear(vma, VM_SOFTDIRTY);
1302                                 vma_set_page_prot(vma);
1303                         }
1304
1305                         inc_tlb_flush_pending(mm);
1306                         mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1307                                                 0, mm, 0, -1UL);
1308                         mmu_notifier_invalidate_range_start(&range);
1309                 }
1310                 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
1311                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1312                         mmu_notifier_invalidate_range_end(&range);
1313                         flush_tlb_mm(mm);
1314                         dec_tlb_flush_pending(mm);
1315                 }
1316 out_unlock:
1317                 mmap_write_unlock(mm);
1318 out_mm:
1319                 mmput(mm);
1320         }
1321         put_task_struct(task);
1322
1323         return count;
1324 }
1325
1326 const struct file_operations proc_clear_refs_operations = {
1327         .write          = clear_refs_write,
1328         .llseek         = noop_llseek,
1329 };
1330
1331 typedef struct {
1332         u64 pme;
1333 } pagemap_entry_t;
1334
1335 struct pagemapread {
1336         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1337         pagemap_entry_t *buffer;
1338         bool show_pfn;
1339 };
1340
1341 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1342 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1343
1344 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1345 #define PM_PFRAME_BITS          55
1346 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1347 #define PM_SOFT_DIRTY           BIT_ULL(55)
1348 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1349 #define PM_UFFD_WP              BIT_ULL(57)
1350 #define PM_FILE                 BIT_ULL(61)
1351 #define PM_SWAP                 BIT_ULL(62)
1352 #define PM_PRESENT              BIT_ULL(63)
1353
1354 #define PM_END_OF_BUFFER    1
1355
1356 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1357 {
1358         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1359 }
1360
1361 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1362                           struct pagemapread *pm)
1363 {
1364         pm->buffer[pm->pos++] = *pme;
1365         if (pm->pos >= pm->len)
1366                 return PM_END_OF_BUFFER;
1367         return 0;
1368 }
1369
1370 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1371                             __always_unused int depth, struct mm_walk *walk)
1372 {
1373         struct pagemapread *pm = walk->private;
1374         unsigned long addr = start;
1375         int err = 0;
1376
1377         while (addr < end) {
1378                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1379                 pagemap_entry_t pme = make_pme(0, 0);
1380                 /* End of address space hole, which we mark as non-present. */
1381                 unsigned long hole_end;
1382
1383                 if (vma)
1384                         hole_end = min(end, vma->vm_start);
1385                 else
1386                         hole_end = end;
1387
1388                 for (; addr < hole_end; addr += PAGE_SIZE) {
1389                         err = add_to_pagemap(addr, &pme, pm);
1390                         if (err)
1391                                 goto out;
1392                 }
1393
1394                 if (!vma)
1395                         break;
1396
1397                 /* Addresses in the VMA. */
1398                 if (vma->vm_flags & VM_SOFTDIRTY)
1399                         pme = make_pme(0, PM_SOFT_DIRTY);
1400                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1401                         err = add_to_pagemap(addr, &pme, pm);
1402                         if (err)
1403                                 goto out;
1404                 }
1405         }
1406 out:
1407         return err;
1408 }
1409
1410 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1411                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1412 {
1413         u64 frame = 0, flags = 0;
1414         struct page *page = NULL;
1415         bool migration = false;
1416
1417         if (pte_present(pte)) {
1418                 if (pm->show_pfn)
1419                         frame = pte_pfn(pte);
1420                 flags |= PM_PRESENT;
1421                 page = vm_normal_page(vma, addr, pte);
1422                 if (pte_soft_dirty(pte))
1423                         flags |= PM_SOFT_DIRTY;
1424                 if (pte_uffd_wp(pte))
1425                         flags |= PM_UFFD_WP;
1426         } else if (is_swap_pte(pte)) {
1427                 swp_entry_t entry;
1428                 if (pte_swp_soft_dirty(pte))
1429                         flags |= PM_SOFT_DIRTY;
1430                 if (pte_swp_uffd_wp(pte))
1431                         flags |= PM_UFFD_WP;
1432                 entry = pte_to_swp_entry(pte);
1433                 if (pm->show_pfn) {
1434                         pgoff_t offset;
1435                         /*
1436                          * For PFN swap offsets, keeping the offset field
1437                          * to be PFN only to be compatible with old smaps.
1438                          */
1439                         if (is_pfn_swap_entry(entry))
1440                                 offset = swp_offset_pfn(entry);
1441                         else
1442                                 offset = swp_offset(entry);
1443                         frame = swp_type(entry) |
1444                             (offset << MAX_SWAPFILES_SHIFT);
1445                 }
1446                 flags |= PM_SWAP;
1447                 migration = is_migration_entry(entry);
1448                 if (is_pfn_swap_entry(entry))
1449                         page = pfn_swap_entry_to_page(entry);
1450                 if (pte_marker_entry_uffd_wp(entry))
1451                         flags |= PM_UFFD_WP;
1452         }
1453
1454         if (page && !PageAnon(page))
1455                 flags |= PM_FILE;
1456         if (page && !migration && page_mapcount(page) == 1)
1457                 flags |= PM_MMAP_EXCLUSIVE;
1458         if (vma->vm_flags & VM_SOFTDIRTY)
1459                 flags |= PM_SOFT_DIRTY;
1460
1461         return make_pme(frame, flags);
1462 }
1463
1464 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1465                              struct mm_walk *walk)
1466 {
1467         struct vm_area_struct *vma = walk->vma;
1468         struct pagemapread *pm = walk->private;
1469         spinlock_t *ptl;
1470         pte_t *pte, *orig_pte;
1471         int err = 0;
1472 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1473         bool migration = false;
1474
1475         ptl = pmd_trans_huge_lock(pmdp, vma);
1476         if (ptl) {
1477                 u64 flags = 0, frame = 0;
1478                 pmd_t pmd = *pmdp;
1479                 struct page *page = NULL;
1480
1481                 if (vma->vm_flags & VM_SOFTDIRTY)
1482                         flags |= PM_SOFT_DIRTY;
1483
1484                 if (pmd_present(pmd)) {
1485                         page = pmd_page(pmd);
1486
1487                         flags |= PM_PRESENT;
1488                         if (pmd_soft_dirty(pmd))
1489                                 flags |= PM_SOFT_DIRTY;
1490                         if (pmd_uffd_wp(pmd))
1491                                 flags |= PM_UFFD_WP;
1492                         if (pm->show_pfn)
1493                                 frame = pmd_pfn(pmd) +
1494                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1495                 }
1496 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1497                 else if (is_swap_pmd(pmd)) {
1498                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1499                         unsigned long offset;
1500
1501                         if (pm->show_pfn) {
1502                                 if (is_pfn_swap_entry(entry))
1503                                         offset = swp_offset_pfn(entry);
1504                                 else
1505                                         offset = swp_offset(entry);
1506                                 offset = offset +
1507                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1508                                 frame = swp_type(entry) |
1509                                         (offset << MAX_SWAPFILES_SHIFT);
1510                         }
1511                         flags |= PM_SWAP;
1512                         if (pmd_swp_soft_dirty(pmd))
1513                                 flags |= PM_SOFT_DIRTY;
1514                         if (pmd_swp_uffd_wp(pmd))
1515                                 flags |= PM_UFFD_WP;
1516                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1517                         migration = is_migration_entry(entry);
1518                         page = pfn_swap_entry_to_page(entry);
1519                 }
1520 #endif
1521
1522                 if (page && !migration && page_mapcount(page) == 1)
1523                         flags |= PM_MMAP_EXCLUSIVE;
1524
1525                 for (; addr != end; addr += PAGE_SIZE) {
1526                         pagemap_entry_t pme = make_pme(frame, flags);
1527
1528                         err = add_to_pagemap(addr, &pme, pm);
1529                         if (err)
1530                                 break;
1531                         if (pm->show_pfn) {
1532                                 if (flags & PM_PRESENT)
1533                                         frame++;
1534                                 else if (flags & PM_SWAP)
1535                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1536                         }
1537                 }
1538                 spin_unlock(ptl);
1539                 return err;
1540         }
1541 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1542
1543         /*
1544          * We can assume that @vma always points to a valid one and @end never
1545          * goes beyond vma->vm_end.
1546          */
1547         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1548         if (!pte) {
1549                 walk->action = ACTION_AGAIN;
1550                 return err;
1551         }
1552         for (; addr < end; pte++, addr += PAGE_SIZE) {
1553                 pagemap_entry_t pme;
1554
1555                 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
1556                 err = add_to_pagemap(addr, &pme, pm);
1557                 if (err)
1558                         break;
1559         }
1560         pte_unmap_unlock(orig_pte, ptl);
1561
1562         cond_resched();
1563
1564         return err;
1565 }
1566
1567 #ifdef CONFIG_HUGETLB_PAGE
1568 /* This function walks within one hugetlb entry in the single call */
1569 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1570                                  unsigned long addr, unsigned long end,
1571                                  struct mm_walk *walk)
1572 {
1573         struct pagemapread *pm = walk->private;
1574         struct vm_area_struct *vma = walk->vma;
1575         u64 flags = 0, frame = 0;
1576         int err = 0;
1577         pte_t pte;
1578
1579         if (vma->vm_flags & VM_SOFTDIRTY)
1580                 flags |= PM_SOFT_DIRTY;
1581
1582         pte = huge_ptep_get(ptep);
1583         if (pte_present(pte)) {
1584                 struct page *page = pte_page(pte);
1585
1586                 if (!PageAnon(page))
1587                         flags |= PM_FILE;
1588
1589                 if (page_mapcount(page) == 1)
1590                         flags |= PM_MMAP_EXCLUSIVE;
1591
1592                 if (huge_pte_uffd_wp(pte))
1593                         flags |= PM_UFFD_WP;
1594
1595                 flags |= PM_PRESENT;
1596                 if (pm->show_pfn)
1597                         frame = pte_pfn(pte) +
1598                                 ((addr & ~hmask) >> PAGE_SHIFT);
1599         } else if (pte_swp_uffd_wp_any(pte)) {
1600                 flags |= PM_UFFD_WP;
1601         }
1602
1603         for (; addr != end; addr += PAGE_SIZE) {
1604                 pagemap_entry_t pme = make_pme(frame, flags);
1605
1606                 err = add_to_pagemap(addr, &pme, pm);
1607                 if (err)
1608                         return err;
1609                 if (pm->show_pfn && (flags & PM_PRESENT))
1610                         frame++;
1611         }
1612
1613         cond_resched();
1614
1615         return err;
1616 }
1617 #else
1618 #define pagemap_hugetlb_range   NULL
1619 #endif /* HUGETLB_PAGE */
1620
1621 static const struct mm_walk_ops pagemap_ops = {
1622         .pmd_entry      = pagemap_pmd_range,
1623         .pte_hole       = pagemap_pte_hole,
1624         .hugetlb_entry  = pagemap_hugetlb_range,
1625 };
1626
1627 /*
1628  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1629  *
1630  * For each page in the address space, this file contains one 64-bit entry
1631  * consisting of the following:
1632  *
1633  * Bits 0-54  page frame number (PFN) if present
1634  * Bits 0-4   swap type if swapped
1635  * Bits 5-54  swap offset if swapped
1636  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1637  * Bit  56    page exclusively mapped
1638  * Bit  57    pte is uffd-wp write-protected
1639  * Bits 58-60 zero
1640  * Bit  61    page is file-page or shared-anon
1641  * Bit  62    page swapped
1642  * Bit  63    page present
1643  *
1644  * If the page is not present but in swap, then the PFN contains an
1645  * encoding of the swap file number and the page's offset into the
1646  * swap. Unmapped pages return a null PFN. This allows determining
1647  * precisely which pages are mapped (or in swap) and comparing mapped
1648  * pages between processes.
1649  *
1650  * Efficient users of this interface will use /proc/pid/maps to
1651  * determine which areas of memory are actually mapped and llseek to
1652  * skip over unmapped regions.
1653  */
1654 static ssize_t pagemap_read(struct file *file, char __user *buf,
1655                             size_t count, loff_t *ppos)
1656 {
1657         struct mm_struct *mm = file->private_data;
1658         struct pagemapread pm;
1659         unsigned long src;
1660         unsigned long svpfn;
1661         unsigned long start_vaddr;
1662         unsigned long end_vaddr;
1663         int ret = 0, copied = 0;
1664
1665         if (!mm || !mmget_not_zero(mm))
1666                 goto out;
1667
1668         ret = -EINVAL;
1669         /* file position must be aligned */
1670         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1671                 goto out_mm;
1672
1673         ret = 0;
1674         if (!count)
1675                 goto out_mm;
1676
1677         /* do not disclose physical addresses: attack vector */
1678         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1679
1680         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1681         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1682         ret = -ENOMEM;
1683         if (!pm.buffer)
1684                 goto out_mm;
1685
1686         src = *ppos;
1687         svpfn = src / PM_ENTRY_BYTES;
1688         end_vaddr = mm->task_size;
1689
1690         /* watch out for wraparound */
1691         start_vaddr = end_vaddr;
1692         if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
1693                 unsigned long end;
1694
1695                 ret = mmap_read_lock_killable(mm);
1696                 if (ret)
1697                         goto out_free;
1698                 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1699                 mmap_read_unlock(mm);
1700
1701                 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1702                 if (end >= start_vaddr && end < mm->task_size)
1703                         end_vaddr = end;
1704         }
1705
1706         /* Ensure the address is inside the task */
1707         if (start_vaddr > mm->task_size)
1708                 start_vaddr = end_vaddr;
1709
1710         ret = 0;
1711         while (count && (start_vaddr < end_vaddr)) {
1712                 int len;
1713                 unsigned long end;
1714
1715                 pm.pos = 0;
1716                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1717                 /* overflow ? */
1718                 if (end < start_vaddr || end > end_vaddr)
1719                         end = end_vaddr;
1720                 ret = mmap_read_lock_killable(mm);
1721                 if (ret)
1722                         goto out_free;
1723                 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1724                 mmap_read_unlock(mm);
1725                 start_vaddr = end;
1726
1727                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1728                 if (copy_to_user(buf, pm.buffer, len)) {
1729                         ret = -EFAULT;
1730                         goto out_free;
1731                 }
1732                 copied += len;
1733                 buf += len;
1734                 count -= len;
1735         }
1736         *ppos += copied;
1737         if (!ret || ret == PM_END_OF_BUFFER)
1738                 ret = copied;
1739
1740 out_free:
1741         kfree(pm.buffer);
1742 out_mm:
1743         mmput(mm);
1744 out:
1745         return ret;
1746 }
1747
1748 static int pagemap_open(struct inode *inode, struct file *file)
1749 {
1750         struct mm_struct *mm;
1751
1752         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1753         if (IS_ERR(mm))
1754                 return PTR_ERR(mm);
1755         file->private_data = mm;
1756         return 0;
1757 }
1758
1759 static int pagemap_release(struct inode *inode, struct file *file)
1760 {
1761         struct mm_struct *mm = file->private_data;
1762
1763         if (mm)
1764                 mmdrop(mm);
1765         return 0;
1766 }
1767
1768 const struct file_operations proc_pagemap_operations = {
1769         .llseek         = mem_lseek, /* borrow this */
1770         .read           = pagemap_read,
1771         .open           = pagemap_open,
1772         .release        = pagemap_release,
1773 };
1774 #endif /* CONFIG_PROC_PAGE_MONITOR */
1775
1776 #ifdef CONFIG_NUMA
1777
1778 struct numa_maps {
1779         unsigned long pages;
1780         unsigned long anon;
1781         unsigned long active;
1782         unsigned long writeback;
1783         unsigned long mapcount_max;
1784         unsigned long dirty;
1785         unsigned long swapcache;
1786         unsigned long node[MAX_NUMNODES];
1787 };
1788
1789 struct numa_maps_private {
1790         struct proc_maps_private proc_maps;
1791         struct numa_maps md;
1792 };
1793
1794 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1795                         unsigned long nr_pages)
1796 {
1797         int count = page_mapcount(page);
1798
1799         md->pages += nr_pages;
1800         if (pte_dirty || PageDirty(page))
1801                 md->dirty += nr_pages;
1802
1803         if (PageSwapCache(page))
1804                 md->swapcache += nr_pages;
1805
1806         if (PageActive(page) || PageUnevictable(page))
1807                 md->active += nr_pages;
1808
1809         if (PageWriteback(page))
1810                 md->writeback += nr_pages;
1811
1812         if (PageAnon(page))
1813                 md->anon += nr_pages;
1814
1815         if (count > md->mapcount_max)
1816                 md->mapcount_max = count;
1817
1818         md->node[page_to_nid(page)] += nr_pages;
1819 }
1820
1821 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1822                 unsigned long addr)
1823 {
1824         struct page *page;
1825         int nid;
1826
1827         if (!pte_present(pte))
1828                 return NULL;
1829
1830         page = vm_normal_page(vma, addr, pte);
1831         if (!page || is_zone_device_page(page))
1832                 return NULL;
1833
1834         if (PageReserved(page))
1835                 return NULL;
1836
1837         nid = page_to_nid(page);
1838         if (!node_isset(nid, node_states[N_MEMORY]))
1839                 return NULL;
1840
1841         return page;
1842 }
1843
1844 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1845 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1846                                               struct vm_area_struct *vma,
1847                                               unsigned long addr)
1848 {
1849         struct page *page;
1850         int nid;
1851
1852         if (!pmd_present(pmd))
1853                 return NULL;
1854
1855         page = vm_normal_page_pmd(vma, addr, pmd);
1856         if (!page)
1857                 return NULL;
1858
1859         if (PageReserved(page))
1860                 return NULL;
1861
1862         nid = page_to_nid(page);
1863         if (!node_isset(nid, node_states[N_MEMORY]))
1864                 return NULL;
1865
1866         return page;
1867 }
1868 #endif
1869
1870 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1871                 unsigned long end, struct mm_walk *walk)
1872 {
1873         struct numa_maps *md = walk->private;
1874         struct vm_area_struct *vma = walk->vma;
1875         spinlock_t *ptl;
1876         pte_t *orig_pte;
1877         pte_t *pte;
1878
1879 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1880         ptl = pmd_trans_huge_lock(pmd, vma);
1881         if (ptl) {
1882                 struct page *page;
1883
1884                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1885                 if (page)
1886                         gather_stats(page, md, pmd_dirty(*pmd),
1887                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1888                 spin_unlock(ptl);
1889                 return 0;
1890         }
1891 #endif
1892         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1893         if (!pte) {
1894                 walk->action = ACTION_AGAIN;
1895                 return 0;
1896         }
1897         do {
1898                 pte_t ptent = ptep_get(pte);
1899                 struct page *page = can_gather_numa_stats(ptent, vma, addr);
1900                 if (!page)
1901                         continue;
1902                 gather_stats(page, md, pte_dirty(ptent), 1);
1903
1904         } while (pte++, addr += PAGE_SIZE, addr != end);
1905         pte_unmap_unlock(orig_pte, ptl);
1906         cond_resched();
1907         return 0;
1908 }
1909 #ifdef CONFIG_HUGETLB_PAGE
1910 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1911                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1912 {
1913         pte_t huge_pte = huge_ptep_get(pte);
1914         struct numa_maps *md;
1915         struct page *page;
1916
1917         if (!pte_present(huge_pte))
1918                 return 0;
1919
1920         page = pte_page(huge_pte);
1921
1922         md = walk->private;
1923         gather_stats(page, md, pte_dirty(huge_pte), 1);
1924         return 0;
1925 }
1926
1927 #else
1928 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1929                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1930 {
1931         return 0;
1932 }
1933 #endif
1934
1935 static const struct mm_walk_ops show_numa_ops = {
1936         .hugetlb_entry = gather_hugetlb_stats,
1937         .pmd_entry = gather_pte_stats,
1938 };
1939
1940 /*
1941  * Display pages allocated per node and memory policy via /proc.
1942  */
1943 static int show_numa_map(struct seq_file *m, void *v)
1944 {
1945         struct numa_maps_private *numa_priv = m->private;
1946         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1947         struct vm_area_struct *vma = v;
1948         struct numa_maps *md = &numa_priv->md;
1949         struct file *file = vma->vm_file;
1950         struct mm_struct *mm = vma->vm_mm;
1951         struct mempolicy *pol;
1952         char buffer[64];
1953         int nid;
1954
1955         if (!mm)
1956                 return 0;
1957
1958         /* Ensure we start with an empty set of numa_maps statistics. */
1959         memset(md, 0, sizeof(*md));
1960
1961         pol = __get_vma_policy(vma, vma->vm_start);
1962         if (pol) {
1963                 mpol_to_str(buffer, sizeof(buffer), pol);
1964                 mpol_cond_put(pol);
1965         } else {
1966                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1967         }
1968
1969         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1970
1971         if (file) {
1972                 seq_puts(m, " file=");
1973                 seq_file_path(m, file, "\n\t= ");
1974         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1975                 seq_puts(m, " heap");
1976         } else if (is_stack(vma)) {
1977                 seq_puts(m, " stack");
1978         }
1979
1980         if (is_vm_hugetlb_page(vma))
1981                 seq_puts(m, " huge");
1982
1983         /* mmap_lock is held by m_start */
1984         walk_page_vma(vma, &show_numa_ops, md);
1985
1986         if (!md->pages)
1987                 goto out;
1988
1989         if (md->anon)
1990                 seq_printf(m, " anon=%lu", md->anon);
1991
1992         if (md->dirty)
1993                 seq_printf(m, " dirty=%lu", md->dirty);
1994
1995         if (md->pages != md->anon && md->pages != md->dirty)
1996                 seq_printf(m, " mapped=%lu", md->pages);
1997
1998         if (md->mapcount_max > 1)
1999                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
2000
2001         if (md->swapcache)
2002                 seq_printf(m, " swapcache=%lu", md->swapcache);
2003
2004         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2005                 seq_printf(m, " active=%lu", md->active);
2006
2007         if (md->writeback)
2008                 seq_printf(m, " writeback=%lu", md->writeback);
2009
2010         for_each_node_state(nid, N_MEMORY)
2011                 if (md->node[nid])
2012                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
2013
2014         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
2015 out:
2016         seq_putc(m, '\n');
2017         return 0;
2018 }
2019
2020 static const struct seq_operations proc_pid_numa_maps_op = {
2021         .start  = m_start,
2022         .next   = m_next,
2023         .stop   = m_stop,
2024         .show   = show_numa_map,
2025 };
2026
2027 static int pid_numa_maps_open(struct inode *inode, struct file *file)
2028 {
2029         return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2030                                 sizeof(struct numa_maps_private));
2031 }
2032
2033 const struct file_operations proc_pid_numa_maps_operations = {
2034         .open           = pid_numa_maps_open,
2035         .read           = seq_read,
2036         .llseek         = seq_lseek,
2037         .release        = proc_map_release,
2038 };
2039
2040 #endif /* CONFIG_NUMA */