fs/proc/task_mmu.c

   1 #include <linux/mm.h>
   2 #include <linux/vmacache.h>
   3 #include <linux/hugetlb.h>
   4 #include <linux/huge_mm.h>
   5 #include <linux/mount.h>
   6 #include <linux/seq_file.h>
   7 #include <linux/highmem.h>
   8 #include <linux/ptrace.h>
   9 #include <linux/slab.h>
  10 #include <linux/pagemap.h>
  11 #include <linux/mempolicy.h>
  12 #include <linux/rmap.h>
  13 #include <linux/swap.h>
  14 #include <linux/swapops.h>
  15 #include <linux/mmu_notifier.h>
  16 #include <linux/page_idle.h>
  17 #include <linux/shmem_fs.h>
  18
  19 #include <asm/elf.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/tlbflush.h>
  22 #include "internal.h"
  23
  24 void task_mem(struct seq_file *m, struct mm_struct *mm)
  25 {
  26         unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
  27         unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  28
  29         anon = get_mm_counter(mm, MM_ANONPAGES);
  30         file = get_mm_counter(mm, MM_FILEPAGES);
  31         shmem = get_mm_counter(mm, MM_SHMEMPAGES);
  32
  33         /*
  34          * Note: to minimize their overhead, mm maintains hiwater_vm and
  35          * hiwater_rss only when about to *lower* total_vm or rss.  Any
  36          * collector of these hiwater stats must therefore get total_vm
  37          * and rss too, which will usually be the higher.  Barriers? not
  38          * worth the effort, such snapshots can always be inconsistent.
  39          */
  40         hiwater_vm = total_vm = mm->total_vm;
  41         if (hiwater_vm < mm->hiwater_vm)
  42                 hiwater_vm = mm->hiwater_vm;
  43         hiwater_rss = total_rss = anon + file + shmem;
  44         if (hiwater_rss < mm->hiwater_rss)
  45                 hiwater_rss = mm->hiwater_rss;
  46
  47         text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
  48         lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
  49         swap = get_mm_counter(mm, MM_SWAPENTS);
  50         ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
  51         pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
  52         seq_printf(m,
  53                 "VmPeak:\t%8lu kB\n"
  54                 "VmSize:\t%8lu kB\n"
  55                 "VmLck:\t%8lu kB\n"
  56                 "VmPin:\t%8lu kB\n"
  57                 "VmHWM:\t%8lu kB\n"
  58                 "VmRSS:\t%8lu kB\n"
  59                 "RssAnon:\t%8lu kB\n"
  60                 "RssFile:\t%8lu kB\n"
  61                 "RssShmem:\t%8lu kB\n"
  62                 "VmData:\t%8lu kB\n"
  63                 "VmStk:\t%8lu kB\n"
  64                 "VmExe:\t%8lu kB\n"
  65                 "VmLib:\t%8lu kB\n"
  66                 "VmPTE:\t%8lu kB\n"
  67                 "VmPMD:\t%8lu kB\n"
  68                 "VmSwap:\t%8lu kB\n",
  69                 hiwater_vm << (PAGE_SHIFT-10),
  70                 total_vm << (PAGE_SHIFT-10),
  71                 mm->locked_vm << (PAGE_SHIFT-10),
  72                 mm->pinned_vm << (PAGE_SHIFT-10),
  73                 hiwater_rss << (PAGE_SHIFT-10),
  74                 total_rss << (PAGE_SHIFT-10),
  75                 anon << (PAGE_SHIFT-10),
  76                 file << (PAGE_SHIFT-10),
  77                 shmem << (PAGE_SHIFT-10),
  78                 mm->data_vm << (PAGE_SHIFT-10),
  79                 mm->stack_vm << (PAGE_SHIFT-10), text, lib,
  80                 ptes >> 10,
  81                 pmds >> 10,
  82                 swap << (PAGE_SHIFT-10));
  83         hugetlb_report_usage(m, mm);
  84 }
  85
  86 unsigned long task_vsize(struct mm_struct *mm)
  87 {
  88         return PAGE_SIZE * mm->total_vm;
  89 }
  90
  91 unsigned long task_statm(struct mm_struct *mm,
  92                          unsigned long *shared, unsigned long *text,
  93                          unsigned long *data, unsigned long *resident)
  94 {
  95         *shared = get_mm_counter(mm, MM_FILEPAGES) +
  96                         get_mm_counter(mm, MM_SHMEMPAGES);
  97         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  98                                                                 >> PAGE_SHIFT;
  99         *data = mm->data_vm + mm->stack_vm;
 100         *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
 101         return mm->total_vm;
 102 }
 103
 104 #ifdef CONFIG_NUMA
 105 /*
 106  * Save get_task_policy() for show_numa_map().
 107  */
 108 static void hold_task_mempolicy(struct proc_maps_private *priv)
 109 {
 110         struct task_struct *task = priv->task;
 111
 112         task_lock(task);
 113         priv->task_mempolicy = get_task_policy(task);
 114         mpol_get(priv->task_mempolicy);
 115         task_unlock(task);
 116 }
 117 static void release_task_mempolicy(struct proc_maps_private *priv)
 118 {
 119         mpol_put(priv->task_mempolicy);
 120 }
 121 #else
 122 static void hold_task_mempolicy(struct proc_maps_private *priv)
 123 {
 124 }
 125 static void release_task_mempolicy(struct proc_maps_private *priv)
 126 {
 127 }
 128 #endif
 129
 130 static void vma_stop(struct proc_maps_private *priv)
 131 {
 132         struct mm_struct *mm = priv->mm;
 133
 134         release_task_mempolicy(priv);
 135         up_read(&mm->mmap_sem);
 136         mmput(mm);
 137 }
 138
 139 static struct vm_area_struct *
 140 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
 141 {
 142         if (vma == priv->tail_vma)
 143                 return NULL;
 144         return vma->vm_next ?: priv->tail_vma;
 145 }
 146
 147 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
 148 {
 149         if (m->count < m->size) /* vma is copied successfully */
 150                 m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
 151 }
 152
 153 static void *m_start(struct seq_file *m, loff_t *ppos)
 154 {
 155         struct proc_maps_private *priv = m->private;
 156         unsigned long last_addr = m->version;
 157         struct mm_struct *mm;
 158         struct vm_area_struct *vma;
 159         unsigned int pos = *ppos;
 160
 161         /* See m_cache_vma(). Zero at the start or after lseek. */
 162         if (last_addr == -1UL)
 163                 return NULL;
 164
 165         priv->task = get_proc_task(priv->inode);
 166         if (!priv->task)
 167                 return ERR_PTR(-ESRCH);
 168
 169         mm = priv->mm;
 170         if (!mm || !atomic_inc_not_zero(&mm->mm_users))
 171                 return NULL;
 172
 173         down_read(&mm->mmap_sem);
 174         hold_task_mempolicy(priv);
 175         priv->tail_vma = get_gate_vma(mm);
 176
 177         if (last_addr) {
 178                 vma = find_vma(mm, last_addr - 1);
 179                 if (vma && vma->vm_start <= last_addr)
 180                         vma = m_next_vma(priv, vma);
 181                 if (vma)
 182                         return vma;
 183         }
 184
 185         m->version = 0;
 186         if (pos < mm->map_count) {
 187                 for (vma = mm->mmap; pos; pos--) {
 188                         m->version = vma->vm_start;
 189                         vma = vma->vm_next;
 190                 }
 191                 return vma;
 192         }
 193
 194         /* we do not bother to update m->version in this case */
 195         if (pos == mm->map_count && priv->tail_vma)
 196                 return priv->tail_vma;
 197
 198         vma_stop(priv);
 199         return NULL;
 200 }
 201
 202 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 203 {
 204         struct proc_maps_private *priv = m->private;
 205         struct vm_area_struct *next;
 206
 207         (*pos)++;
 208         next = m_next_vma(priv, v);
 209         if (!next)
 210                 vma_stop(priv);
 211         return next;
 212 }
 213
 214 static void m_stop(struct seq_file *m, void *v)
 215 {
 216         struct proc_maps_private *priv = m->private;
 217
 218         if (!IS_ERR_OR_NULL(v))
 219                 vma_stop(priv);
 220         if (priv->task) {
 221                 put_task_struct(priv->task);
 222                 priv->task = NULL;
 223         }
 224 }
 225
 226 static int proc_maps_open(struct inode *inode, struct file *file,
 227                         const struct seq_operations *ops, int psize)
 228 {
 229         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
 230
 231         if (!priv)
 232                 return -ENOMEM;
 233
 234         priv->inode = inode;
 235         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 236         if (IS_ERR(priv->mm)) {
 237                 int err = PTR_ERR(priv->mm);
 238
 239                 seq_release_private(inode, file);
 240                 return err;
 241         }
 242
 243         return 0;
 244 }
 245
 246 static int proc_map_release(struct inode *inode, struct file *file)
 247 {
 248         struct seq_file *seq = file->private_data;
 249         struct proc_maps_private *priv = seq->private;
 250
 251         if (priv->mm)
 252                 mmdrop(priv->mm);
 253
 254         return seq_release_private(inode, file);
 255 }
 256
 257 static int do_maps_open(struct inode *inode, struct file *file,
 258                         const struct seq_operations *ops)
 259 {
 260         return proc_maps_open(inode, file, ops,
 261                                 sizeof(struct proc_maps_private));
 262 }
 263
 264 /*
 265  * Indicate if the VMA is a stack for the given task; for
 266  * /proc/PID/maps that is the stack of the main task.
 267  */
 268 static int is_stack(struct proc_maps_private *priv,
 269                     struct vm_area_struct *vma, int is_pid)
 270 {
 271         int stack = 0;
 272
 273         if (is_pid) {
 274                 stack = vma->vm_start <= vma->vm_mm->start_stack &&
 275                         vma->vm_end >= vma->vm_mm->start_stack;
 276         } else {
 277                 struct inode *inode = priv->inode;
 278                 struct task_struct *task;
 279
 280                 rcu_read_lock();
 281                 task = pid_task(proc_pid(inode), PIDTYPE_PID);
 282                 if (task)
 283                         stack = vma_is_stack_for_task(vma, task);
 284                 rcu_read_unlock();
 285         }
 286         return stack;
 287 }
 288
 289 static void
 290 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 291 {
 292         struct mm_struct *mm = vma->vm_mm;
 293         struct file *file = vma->vm_file;
 294         struct proc_maps_private *priv = m->private;
 295         vm_flags_t flags = vma->vm_flags;
 296         unsigned long ino = 0;
 297         unsigned long long pgoff = 0;
 298         unsigned long start, end;
 299         dev_t dev = 0;
 300         const char *name = NULL;
 301
 302         if (file) {
 303                 struct inode *inode = file_inode(vma->vm_file);
 304                 dev = inode->i_sb->s_dev;
 305                 ino = inode->i_ino;
 306                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 307         }
 308
 309         /* We don't show the stack guard page in /proc/maps */
 310         start = vma->vm_start;
 311         if (stack_guard_page_start(vma, start))
 312                 start += PAGE_SIZE;
 313         end = vma->vm_end;
 314         if (stack_guard_page_end(vma, end))
 315                 end -= PAGE_SIZE;
 316
 317         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 318         seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
 319                         start,
 320                         end,
 321                         flags & VM_READ ? 'r' : '-',
 322                         flags & VM_WRITE ? 'w' : '-',
 323                         flags & VM_EXEC ? 'x' : '-',
 324                         flags & VM_MAYSHARE ? 's' : 'p',
 325                         pgoff,
 326                         MAJOR(dev), MINOR(dev), ino);
 327
 328         /*
 329          * Print the dentry name for named mappings, and a
 330          * special [heap] marker for the heap:
 331          */
 332         if (file) {
 333                 seq_pad(m, ' ');
 334                 seq_file_path(m, file, "\n");
 335                 goto done;
 336         }
 337
 338         if (vma->vm_ops && vma->vm_ops->name) {
 339                 name = vma->vm_ops->name(vma);
 340                 if (name)
 341                         goto done;
 342         }
 343
 344         name = arch_vma_name(vma);
 345         if (!name) {
 346                 if (!mm) {
 347                         name = "[vdso]";
 348                         goto done;
 349                 }
 350
 351                 if (vma->vm_start <= mm->brk &&
 352                     vma->vm_end >= mm->start_brk) {
 353                         name = "[heap]";
 354                         goto done;
 355                 }
 356
 357                 if (is_stack(priv, vma, is_pid))
 358                         name = "[stack]";
 359         }
 360
 361 done:
 362         if (name) {
 363                 seq_pad(m, ' ');
 364                 seq_puts(m, name);
 365         }
 366         seq_putc(m, '\n');
 367 }
 368
 369 static int show_map(struct seq_file *m, void *v, int is_pid)
 370 {
 371         show_map_vma(m, v, is_pid);
 372         m_cache_vma(m, v);
 373         return 0;
 374 }
 375
 376 static int show_pid_map(struct seq_file *m, void *v)
 377 {
 378         return show_map(m, v, 1);
 379 }
 380
 381 static int show_tid_map(struct seq_file *m, void *v)
 382 {
 383         return show_map(m, v, 0);
 384 }
 385
 386 static const struct seq_operations proc_pid_maps_op = {
 387         .start  = m_start,
 388         .next   = m_next,
 389         .stop   = m_stop,
 390         .show   = show_pid_map
 391 };
 392
 393 static const struct seq_operations proc_tid_maps_op = {
 394         .start  = m_start,
 395         .next   = m_next,
 396         .stop   = m_stop,
 397         .show   = show_tid_map
 398 };
 399
 400 static int pid_maps_open(struct inode *inode, struct file *file)
 401 {
 402         return do_maps_open(inode, file, &proc_pid_maps_op);
 403 }
 404
 405 static int tid_maps_open(struct inode *inode, struct file *file)
 406 {
 407         return do_maps_open(inode, file, &proc_tid_maps_op);
 408 }
 409
 410 const struct file_operations proc_pid_maps_operations = {
 411         .open           = pid_maps_open,
 412         .read           = seq_read,
 413         .llseek         = seq_lseek,
 414         .release        = proc_map_release,
 415 };
 416
 417 const struct file_operations proc_tid_maps_operations = {
 418         .open           = tid_maps_open,
 419         .read           = seq_read,
 420         .llseek         = seq_lseek,
 421         .release        = proc_map_release,
 422 };
 423
 424 /*
 425  * Proportional Set Size(PSS): my share of RSS.
 426  *
 427  * PSS of a process is the count of pages it has in memory, where each
 428  * page is divided by the number of processes sharing it.  So if a
 429  * process has 1000 pages all to itself, and 1000 shared with one other
 430  * process, its PSS will be 1500.
 431  *
 432  * To keep (accumulated) division errors low, we adopt a 64bit
 433  * fixed-point pss counter to minimize division errors. So (pss >>
 434  * PSS_SHIFT) would be the real byte count.
 435  *
 436  * A shift of 12 before division means (assuming 4K page size):
 437  *      - 1M 3-user-pages add up to 8KB errors;
 438  *      - supports mapcount up to 2^24, or 16M;
 439  *      - supports PSS up to 2^52 bytes, or 4PB.
 440  */
 441 #define PSS_SHIFT 12
 442
 443 #ifdef CONFIG_PROC_PAGE_MONITOR
 444 struct mem_size_stats {
 445         unsigned long resident;
 446         unsigned long shared_clean;
 447         unsigned long shared_dirty;
 448         unsigned long private_clean;
 449         unsigned long private_dirty;
 450         unsigned long referenced;
 451         unsigned long anonymous;
 452         unsigned long anonymous_thp;
 453         unsigned long shmem_thp;
 454         unsigned long swap;
 455         unsigned long shared_hugetlb;
 456         unsigned long private_hugetlb;
 457         u64 pss;
 458         u64 swap_pss;
 459         bool check_shmem_swap;
 460 };
 461
 462 static void smaps_account(struct mem_size_stats *mss, struct page *page,
 463                 bool compound, bool young, bool dirty)
 464 {
 465         int i, nr = compound ? 1 << compound_order(page) : 1;
 466         unsigned long size = nr * PAGE_SIZE;
 467
 468         if (PageAnon(page))
 469                 mss->anonymous += size;
 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          * page_count(page) == 1 guarantees the page is mapped exactly once.
 478          * If any subpage of the compound page mapped with PTE it would elevate
 479          * page_count().
 480          */
 481         if (page_count(page) == 1) {
 482                 if (dirty || PageDirty(page))
 483                         mss->private_dirty += size;
 484                 else
 485                         mss->private_clean += size;
 486                 mss->pss += (u64)size << PSS_SHIFT;
 487                 return;
 488         }
 489
 490         for (i = 0; i < nr; i++, page++) {
 491                 int mapcount = page_mapcount(page);
 492
 493                 if (mapcount >= 2) {
 494                         if (dirty || PageDirty(page))
 495                                 mss->shared_dirty += PAGE_SIZE;
 496                         else
 497                                 mss->shared_clean += PAGE_SIZE;
 498                         mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
 499                 } else {
 500                         if (dirty || PageDirty(page))
 501                                 mss->private_dirty += PAGE_SIZE;
 502                         else
 503                                 mss->private_clean += PAGE_SIZE;
 504                         mss->pss += PAGE_SIZE << PSS_SHIFT;
 505                 }
 506         }
 507 }
 508
 509 #ifdef CONFIG_SHMEM
 510 static int smaps_pte_hole(unsigned long addr, unsigned long end,
 511                 struct mm_walk *walk)
 512 {
 513         struct mem_size_stats *mss = walk->private;
 514
 515         mss->swap += shmem_partial_swap_usage(
 516                         walk->vma->vm_file->f_mapping, addr, end);
 517
 518         return 0;
 519 }
 520 #endif
 521
 522 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 523                 struct mm_walk *walk)
 524 {
 525         struct mem_size_stats *mss = walk->private;
 526         struct vm_area_struct *vma = walk->vma;
 527         struct page *page = NULL;
 528
 529         if (pte_present(*pte)) {
 530                 page = vm_normal_page(vma, addr, *pte);
 531         } else if (is_swap_pte(*pte)) {
 532                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 533
 534                 if (!non_swap_entry(swpent)) {
 535                         int mapcount;
 536
 537                         mss->swap += PAGE_SIZE;
 538                         mapcount = swp_swapcount(swpent);
 539                         if (mapcount >= 2) {
 540                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
 541
 542                                 do_div(pss_delta, mapcount);
 543                                 mss->swap_pss += pss_delta;
 544                         } else {
 545                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
 546                         }
 547                 } else if (is_migration_entry(swpent))
 548                         page = migration_entry_to_page(swpent);
 549         } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
 550                                                         && pte_none(*pte))) {
 551                 page = find_get_entry(vma->vm_file->f_mapping,
 552                                                 linear_page_index(vma, addr));
 553                 if (!page)
 554                         return;
 555
 556                 if (radix_tree_exceptional_entry(page))
 557                         mss->swap += PAGE_SIZE;
 558                 else
 559                         put_page(page);
 560
 561                 return;
 562         }
 563
 564         if (!page)
 565                 return;
 566
 567         smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
 568 }
 569
 570 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 571 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 572                 struct mm_walk *walk)
 573 {
 574         struct mem_size_stats *mss = walk->private;
 575         struct vm_area_struct *vma = walk->vma;
 576         struct page *page;
 577
 578         /* FOLL_DUMP will return -EFAULT on huge zero page */
 579         page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
 580         if (IS_ERR_OR_NULL(page))
 581                 return;
 582         if (PageAnon(page))
 583                 mss->anonymous_thp += HPAGE_PMD_SIZE;
 584         else if (PageSwapBacked(page))
 585                 mss->shmem_thp += HPAGE_PMD_SIZE;
 586         else if (is_zone_device_page(page))
 587                 /* pass */;
 588         else
 589                 VM_BUG_ON_PAGE(1, page);
 590         smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
 591 }
 592 #else
 593 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 594                 struct mm_walk *walk)
 595 {
 596 }
 597 #endif
 598
 599 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 600                            struct mm_walk *walk)
 601 {
 602         struct vm_area_struct *vma = walk->vma;
 603         pte_t *pte;
 604         spinlock_t *ptl;
 605
 606         ptl = pmd_trans_huge_lock(pmd, vma);
 607         if (ptl) {
 608                 smaps_pmd_entry(pmd, addr, walk);
 609                 spin_unlock(ptl);
 610                 return 0;
 611         }
 612
 613         if (pmd_trans_unstable(pmd))
 614                 return 0;
 615         /*
 616          * The mmap_sem held all the way back in m_start() is what
 617          * keeps khugepaged out of here and from collapsing things
 618          * in here.
 619          */
 620         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 621         for (; addr != end; pte++, addr += PAGE_SIZE)
 622                 smaps_pte_entry(pte, addr, walk);
 623         pte_unmap_unlock(pte - 1, ptl);
 624         cond_resched();
 625         return 0;
 626 }
 627
 628 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 629 {
 630         /*
 631          * Don't forget to update Documentation/ on changes.
 632          */
 633         static const char mnemonics[BITS_PER_LONG][2] = {
 634                 /*
 635                  * In case if we meet a flag we don't know about.
 636                  */
 637                 [0 ... (BITS_PER_LONG-1)] = "??",
 638
 639                 [ilog2(VM_READ)]        = "rd",
 640                 [ilog2(VM_WRITE)]       = "wr",
 641                 [ilog2(VM_EXEC)]        = "ex",
 642                 [ilog2(VM_SHARED)]      = "sh",
 643                 [ilog2(VM_MAYREAD)]     = "mr",
 644                 [ilog2(VM_MAYWRITE)]    = "mw",
 645                 [ilog2(VM_MAYEXEC)]     = "me",
 646                 [ilog2(VM_MAYSHARE)]    = "ms",
 647                 [ilog2(VM_GROWSDOWN)]   = "gd",
 648                 [ilog2(VM_PFNMAP)]      = "pf",
 649                 [ilog2(VM_DENYWRITE)]   = "dw",
 650 #ifdef CONFIG_X86_INTEL_MPX
 651                 [ilog2(VM_MPX)]         = "mp",
 652 #endif
 653                 [ilog2(VM_LOCKED)]      = "lo",
 654                 [ilog2(VM_IO)]          = "io",
 655                 [ilog2(VM_SEQ_READ)]    = "sr",
 656                 [ilog2(VM_RAND_READ)]   = "rr",
 657                 [ilog2(VM_DONTCOPY)]    = "dc",
 658                 [ilog2(VM_DONTEXPAND)]  = "de",
 659                 [ilog2(VM_ACCOUNT)]     = "ac",
 660                 [ilog2(VM_NORESERVE)]   = "nr",
 661                 [ilog2(VM_HUGETLB)]     = "ht",
 662                 [ilog2(VM_ARCH_1)]      = "ar",
 663                 [ilog2(VM_DONTDUMP)]    = "dd",
 664 #ifdef CONFIG_MEM_SOFT_DIRTY
 665                 [ilog2(VM_SOFTDIRTY)]   = "sd",
 666 #endif
 667                 [ilog2(VM_MIXEDMAP)]    = "mm",
 668                 [ilog2(VM_HUGEPAGE)]    = "hg",
 669                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
 670                 [ilog2(VM_MERGEABLE)]   = "mg",
 671                 [ilog2(VM_UFFD_MISSING)]= "um",
 672                 [ilog2(VM_UFFD_WP)]     = "uw",
 673 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
 674                 /* These come out via ProtectionKey: */
 675                 [ilog2(VM_PKEY_BIT0)]   = "",
 676                 [ilog2(VM_PKEY_BIT1)]   = "",
 677                 [ilog2(VM_PKEY_BIT2)]   = "",
 678                 [ilog2(VM_PKEY_BIT3)]   = "",
 679 #endif
 680         };
 681         size_t i;
 682
 683         seq_puts(m, "VmFlags: ");
 684         for (i = 0; i < BITS_PER_LONG; i++) {
 685                 if (!mnemonics[i][0])
 686                         continue;
 687                 if (vma->vm_flags & (1UL << i)) {
 688                         seq_printf(m, "%c%c ",
 689                                    mnemonics[i][0], mnemonics[i][1]);
 690                 }
 691         }
 692         seq_putc(m, '\n');
 693 }
 694
 695 #ifdef CONFIG_HUGETLB_PAGE
 696 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 697                                  unsigned long addr, unsigned long end,
 698                                  struct mm_walk *walk)
 699 {
 700         struct mem_size_stats *mss = walk->private;
 701         struct vm_area_struct *vma = walk->vma;
 702         struct page *page = NULL;
 703
 704         if (pte_present(*pte)) {
 705                 page = vm_normal_page(vma, addr, *pte);
 706         } else if (is_swap_pte(*pte)) {
 707                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 708
 709                 if (is_migration_entry(swpent))
 710                         page = migration_entry_to_page(swpent);
 711         }
 712         if (page) {
 713                 int mapcount = page_mapcount(page);
 714
 715                 if (mapcount >= 2)
 716                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
 717                 else
 718                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
 719         }
 720         return 0;
 721 }
 722 #endif /* HUGETLB_PAGE */
 723
 724 void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
 725 {
 726 }
 727
 728 static int show_smap(struct seq_file *m, void *v, int is_pid)
 729 {
 730         struct vm_area_struct *vma = v;
 731         struct mem_size_stats mss;
 732         struct mm_walk smaps_walk = {
 733                 .pmd_entry = smaps_pte_range,
 734 #ifdef CONFIG_HUGETLB_PAGE
 735                 .hugetlb_entry = smaps_hugetlb_range,
 736 #endif
 737                 .mm = vma->vm_mm,
 738                 .private = &mss,
 739         };
 740
 741         memset(&mss, 0, sizeof mss);
 742
 743 #ifdef CONFIG_SHMEM
 744         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
 745                 /*
 746                  * For shared or readonly shmem mappings we know that all
 747                  * swapped out pages belong to the shmem object, and we can
 748                  * obtain the swap value much more efficiently. For private
 749                  * writable mappings, we might have COW pages that are
 750                  * not affected by the parent swapped out pages of the shmem
 751                  * object, so we have to distinguish them during the page walk.
 752                  * Unless we know that the shmem object (or the part mapped by
 753                  * our VMA) has no swapped out pages at all.
 754                  */
 755                 unsigned long shmem_swapped = shmem_swap_usage(vma);
 756
 757                 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
 758                                         !(vma->vm_flags & VM_WRITE)) {
 759                         mss.swap = shmem_swapped;
 760                 } else {
 761                         mss.check_shmem_swap = true;
 762                         smaps_walk.pte_hole = smaps_pte_hole;
 763                 }
 764         }
 765 #endif
 766
 767         /* mmap_sem is held in m_start */
 768         walk_page_vma(vma, &smaps_walk);
 769
 770         show_map_vma(m, vma, is_pid);
 771
 772         seq_printf(m,
 773                    "Size:           %8lu kB\n"
 774                    "Rss:            %8lu kB\n"
 775                    "Pss:            %8lu kB\n"
 776                    "Shared_Clean:   %8lu kB\n"
 777                    "Shared_Dirty:   %8lu kB\n"
 778                    "Private_Clean:  %8lu kB\n"
 779                    "Private_Dirty:  %8lu kB\n"
 780                    "Referenced:     %8lu kB\n"
 781                    "Anonymous:      %8lu kB\n"
 782                    "AnonHugePages:  %8lu kB\n"
 783                    "ShmemPmdMapped: %8lu kB\n"
 784                    "Shared_Hugetlb: %8lu kB\n"
 785                    "Private_Hugetlb: %7lu kB\n"
 786                    "Swap:           %8lu kB\n"
 787                    "SwapPss:        %8lu kB\n"
 788                    "KernelPageSize: %8lu kB\n"
 789                    "MMUPageSize:    %8lu kB\n"
 790                    "Locked:         %8lu kB\n",
 791                    (vma->vm_end - vma->vm_start) >> 10,
 792                    mss.resident >> 10,
 793                    (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
 794                    mss.shared_clean  >> 10,
 795                    mss.shared_dirty  >> 10,
 796                    mss.private_clean >> 10,
 797                    mss.private_dirty >> 10,
 798                    mss.referenced >> 10,
 799                    mss.anonymous >> 10,
 800                    mss.anonymous_thp >> 10,
 801                    mss.shmem_thp >> 10,
 802                    mss.shared_hugetlb >> 10,
 803                    mss.private_hugetlb >> 10,
 804                    mss.swap >> 10,
 805                    (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
 806                    vma_kernel_pagesize(vma) >> 10,
 807                    vma_mmu_pagesize(vma) >> 10,
 808                    (vma->vm_flags & VM_LOCKED) ?
 809                         (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
 810
 811         arch_show_smap(m, vma);
 812         show_smap_vma_flags(m, vma);
 813         m_cache_vma(m, vma);
 814         return 0;
 815 }
 816
 817 static int show_pid_smap(struct seq_file *m, void *v)
 818 {
 819         return show_smap(m, v, 1);
 820 }
 821
 822 static int show_tid_smap(struct seq_file *m, void *v)
 823 {
 824         return show_smap(m, v, 0);
 825 }
 826
 827 static const struct seq_operations proc_pid_smaps_op = {
 828         .start  = m_start,
 829         .next   = m_next,
 830         .stop   = m_stop,
 831         .show   = show_pid_smap
 832 };
 833
 834 static const struct seq_operations proc_tid_smaps_op = {
 835         .start  = m_start,
 836         .next   = m_next,
 837         .stop   = m_stop,
 838         .show   = show_tid_smap
 839 };
 840
 841 static int pid_smaps_open(struct inode *inode, struct file *file)
 842 {
 843         return do_maps_open(inode, file, &proc_pid_smaps_op);
 844 }
 845
 846 static int tid_smaps_open(struct inode *inode, struct file *file)
 847 {
 848         return do_maps_open(inode, file, &proc_tid_smaps_op);
 849 }
 850
 851 const struct file_operations proc_pid_smaps_operations = {
 852         .open           = pid_smaps_open,
 853         .read           = seq_read,
 854         .llseek         = seq_lseek,
 855         .release        = proc_map_release,
 856 };
 857
 858 const struct file_operations proc_tid_smaps_operations = {
 859         .open           = tid_smaps_open,
 860         .read           = seq_read,
 861         .llseek         = seq_lseek,
 862         .release        = proc_map_release,
 863 };
 864
 865 enum clear_refs_types {
 866         CLEAR_REFS_ALL = 1,
 867         CLEAR_REFS_ANON,
 868         CLEAR_REFS_MAPPED,
 869         CLEAR_REFS_SOFT_DIRTY,
 870         CLEAR_REFS_MM_HIWATER_RSS,
 871         CLEAR_REFS_LAST,
 872 };
 873
 874 struct clear_refs_private {
 875         enum clear_refs_types type;
 876 };
 877
 878 #ifdef CONFIG_MEM_SOFT_DIRTY
 879 static inline void clear_soft_dirty(struct vm_area_struct *vma,
 880                 unsigned long addr, pte_t *pte)
 881 {
 882         /*
 883          * The soft-dirty tracker uses #PF-s to catch writes
 884          * to pages, so write-protect the pte as well. See the
 885          * Documentation/vm/soft-dirty.txt for full description
 886          * of how soft-dirty works.
 887          */
 888         pte_t ptent = *pte;
 889
 890         if (pte_present(ptent)) {
 891                 ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
 892                 ptent = pte_wrprotect(ptent);
 893                 ptent = pte_clear_soft_dirty(ptent);
 894                 ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
 895         } else if (is_swap_pte(ptent)) {
 896                 ptent = pte_swp_clear_soft_dirty(ptent);
 897                 set_pte_at(vma->vm_mm, addr, pte, ptent);
 898         }
 899 }
 900 #else
 901 static inline void clear_soft_dirty(struct vm_area_struct *vma,
 902                 unsigned long addr, pte_t *pte)
 903 {
 904 }
 905 #endif
 906
 907 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 908 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 909                 unsigned long addr, pmd_t *pmdp)
 910 {
 911         pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
 912
 913         pmd = pmd_wrprotect(pmd);
 914         pmd = pmd_clear_soft_dirty(pmd);
 915
 916         set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
 917 }
 918 #else
 919 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 920                 unsigned long addr, pmd_t *pmdp)
 921 {
 922 }
 923 #endif
 924
 925 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 926                                 unsigned long end, struct mm_walk *walk)
 927 {
 928         struct clear_refs_private *cp = walk->private;
 929         struct vm_area_struct *vma = walk->vma;
 930         pte_t *pte, ptent;
 931         spinlock_t *ptl;
 932         struct page *page;
 933
 934         ptl = pmd_trans_huge_lock(pmd, vma);
 935         if (ptl) {
 936                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
 937                         clear_soft_dirty_pmd(vma, addr, pmd);
 938                         goto out;
 939                 }
 940
 941                 page = pmd_page(*pmd);
 942
 943                 /* Clear accessed and referenced bits. */
 944                 pmdp_test_and_clear_young(vma, addr, pmd);
 945                 test_and_clear_page_young(page);
 946                 ClearPageReferenced(page);
 947 out:
 948                 spin_unlock(ptl);
 949                 return 0;
 950         }
 951
 952         if (pmd_trans_unstable(pmd))
 953                 return 0;
 954
 955         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 956         for (; addr != end; pte++, addr += PAGE_SIZE) {
 957                 ptent = *pte;
 958
 959                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
 960                         clear_soft_dirty(vma, addr, pte);
 961                         continue;
 962                 }
 963
 964                 if (!pte_present(ptent))
 965                         continue;
 966
 967                 page = vm_normal_page(vma, addr, ptent);
 968                 if (!page)
 969                         continue;
 970
 971                 /* Clear accessed and referenced bits. */
 972                 ptep_test_and_clear_young(vma, addr, pte);
 973                 test_and_clear_page_young(page);
 974                 ClearPageReferenced(page);
 975         }
 976         pte_unmap_unlock(pte - 1, ptl);
 977         cond_resched();
 978         return 0;
 979 }
 980
 981 static int clear_refs_test_walk(unsigned long start, unsigned long end,
 982                                 struct mm_walk *walk)
 983 {
 984         struct clear_refs_private *cp = walk->private;
 985         struct vm_area_struct *vma = walk->vma;
 986
 987         if (vma->vm_flags & VM_PFNMAP)
 988                 return 1;
 989
 990         /*
 991          * Writing 1 to /proc/pid/clear_refs affects all pages.
 992          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
 993          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
 994          * Writing 4 to /proc/pid/clear_refs affects all pages.
 995          */
 996         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
 997                 return 1;
 998         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
 999                 return 1;
1000         return 0;
1001 }
1002
1003 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1004                                 size_t count, loff_t *ppos)
1005 {
1006         struct task_struct *task;
1007         char buffer[PROC_NUMBUF];
1008         struct mm_struct *mm;
1009         struct vm_area_struct *vma;
1010         enum clear_refs_types type;
1011         int itype;
1012         int rv;
1013
1014         memset(buffer, 0, sizeof(buffer));
1015         if (count > sizeof(buffer) - 1)
1016                 count = sizeof(buffer) - 1;
1017         if (copy_from_user(buffer, buf, count))
1018                 return -EFAULT;
1019         rv = kstrtoint(strstrip(buffer), 10, &itype);
1020         if (rv < 0)
1021                 return rv;
1022         type = (enum clear_refs_types)itype;
1023         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1024                 return -EINVAL;
1025
1026         task = get_proc_task(file_inode(file));
1027         if (!task)
1028                 return -ESRCH;
1029         mm = get_task_mm(task);
1030         if (mm) {
1031                 struct clear_refs_private cp = {
1032                         .type = type,
1033                 };
1034                 struct mm_walk clear_refs_walk = {
1035                         .pmd_entry = clear_refs_pte_range,
1036                         .test_walk = clear_refs_test_walk,
1037                         .mm = mm,
1038                         .private = &cp,
1039                 };
1040
1041                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1042                         if (down_write_killable(&mm->mmap_sem)) {
1043                                 count = -EINTR;
1044                                 goto out_mm;
1045                         }
1046
1047                         /*
1048                          * Writing 5 to /proc/pid/clear_refs resets the peak
1049                          * resident set size to this mm's current rss value.
1050                          */
1051                         reset_mm_hiwater_rss(mm);
1052                         up_write(&mm->mmap_sem);
1053                         goto out_mm;
1054                 }
1055
1056                 down_read(&mm->mmap_sem);
1057                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1058                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1059                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1060                                         continue;
1061                                 up_read(&mm->mmap_sem);
1062                                 if (down_write_killable(&mm->mmap_sem)) {
1063                                         count = -EINTR;
1064                                         goto out_mm;
1065                                 }
1066                                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1067                                         vma->vm_flags &= ~VM_SOFTDIRTY;
1068                                         vma_set_page_prot(vma);
1069                                 }
1070                                 downgrade_write(&mm->mmap_sem);
1071                                 break;
1072                         }
1073                         mmu_notifier_invalidate_range_start(mm, 0, -1);
1074                 }
1075                 walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1076                 if (type == CLEAR_REFS_SOFT_DIRTY)
1077                         mmu_notifier_invalidate_range_end(mm, 0, -1);
1078                 flush_tlb_mm(mm);
1079                 up_read(&mm->mmap_sem);
1080 out_mm:
1081                 mmput(mm);
1082         }
1083         put_task_struct(task);
1084
1085         return count;
1086 }
1087
1088 const struct file_operations proc_clear_refs_operations = {
1089         .write          = clear_refs_write,
1090         .llseek         = noop_llseek,
1091 };
1092
1093 typedef struct {
1094         u64 pme;
1095 } pagemap_entry_t;
1096
1097 struct pagemapread {
1098         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1099         pagemap_entry_t *buffer;
1100         bool show_pfn;
1101 };
1102
1103 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1104 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1105
1106 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1107 #define PM_PFRAME_BITS          55
1108 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1109 #define PM_SOFT_DIRTY           BIT_ULL(55)
1110 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1111 #define PM_FILE                 BIT_ULL(61)
1112 #define PM_SWAP                 BIT_ULL(62)
1113 #define PM_PRESENT              BIT_ULL(63)
1114
1115 #define PM_END_OF_BUFFER    1
1116
1117 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1118 {
1119         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1120 }
1121
1122 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1123                           struct pagemapread *pm)
1124 {
1125         pm->buffer[pm->pos++] = *pme;
1126         if (pm->pos >= pm->len)
1127                 return PM_END_OF_BUFFER;
1128         return 0;
1129 }
1130
1131 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1132                                 struct mm_walk *walk)
1133 {
1134         struct pagemapread *pm = walk->private;
1135         unsigned long addr = start;
1136         int err = 0;
1137
1138         while (addr < end) {
1139                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1140                 pagemap_entry_t pme = make_pme(0, 0);
1141                 /* End of address space hole, which we mark as non-present. */
1142                 unsigned long hole_end;
1143
1144                 if (vma)
1145                         hole_end = min(end, vma->vm_start);
1146                 else
1147                         hole_end = end;
1148
1149                 for (; addr < hole_end; addr += PAGE_SIZE) {
1150                         err = add_to_pagemap(addr, &pme, pm);
1151                         if (err)
1152                                 goto out;
1153                 }
1154
1155                 if (!vma)
1156                         break;
1157
1158                 /* Addresses in the VMA. */
1159                 if (vma->vm_flags & VM_SOFTDIRTY)
1160                         pme = make_pme(0, PM_SOFT_DIRTY);
1161                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1162                         err = add_to_pagemap(addr, &pme, pm);
1163                         if (err)
1164                                 goto out;
1165                 }
1166         }
1167 out:
1168         return err;
1169 }
1170
1171 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1172                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1173 {
1174         u64 frame = 0, flags = 0;
1175         struct page *page = NULL;
1176
1177         if (pte_present(pte)) {
1178                 if (pm->show_pfn)
1179                         frame = pte_pfn(pte);
1180                 flags |= PM_PRESENT;
1181                 page = vm_normal_page(vma, addr, pte);
1182                 if (pte_soft_dirty(pte))
1183                         flags |= PM_SOFT_DIRTY;
1184         } else if (is_swap_pte(pte)) {
1185                 swp_entry_t entry;
1186                 if (pte_swp_soft_dirty(pte))
1187                         flags |= PM_SOFT_DIRTY;
1188                 entry = pte_to_swp_entry(pte);
1189                 frame = swp_type(entry) |
1190                         (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1191                 flags |= PM_SWAP;
1192                 if (is_migration_entry(entry))
1193                         page = migration_entry_to_page(entry);
1194         }
1195
1196         if (page && !PageAnon(page))
1197                 flags |= PM_FILE;
1198         if (page && page_mapcount(page) == 1)
1199                 flags |= PM_MMAP_EXCLUSIVE;
1200         if (vma->vm_flags & VM_SOFTDIRTY)
1201                 flags |= PM_SOFT_DIRTY;
1202
1203         return make_pme(frame, flags);
1204 }
1205
1206 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1207                              struct mm_walk *walk)
1208 {
1209         struct vm_area_struct *vma = walk->vma;
1210         struct pagemapread *pm = walk->private;
1211         spinlock_t *ptl;
1212         pte_t *pte, *orig_pte;
1213         int err = 0;
1214
1215 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1216         ptl = pmd_trans_huge_lock(pmdp, vma);
1217         if (ptl) {
1218                 u64 flags = 0, frame = 0;
1219                 pmd_t pmd = *pmdp;
1220
1221                 if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
1222                         flags |= PM_SOFT_DIRTY;
1223
1224                 /*
1225                  * Currently pmd for thp is always present because thp
1226                  * can not be swapped-out, migrated, or HWPOISONed
1227                  * (split in such cases instead.)
1228                  * This if-check is just to prepare for future implementation.
1229                  */
1230                 if (pmd_present(pmd)) {
1231                         struct page *page = pmd_page(pmd);
1232
1233                         if (page_mapcount(page) == 1)
1234                                 flags |= PM_MMAP_EXCLUSIVE;
1235
1236                         flags |= PM_PRESENT;
1237                         if (pm->show_pfn)
1238                                 frame = pmd_pfn(pmd) +
1239                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1240                 }
1241
1242                 for (; addr != end; addr += PAGE_SIZE) {
1243                         pagemap_entry_t pme = make_pme(frame, flags);
1244
1245                         err = add_to_pagemap(addr, &pme, pm);
1246                         if (err)
1247                                 break;
1248                         if (pm->show_pfn && (flags & PM_PRESENT))
1249                                 frame++;
1250                 }
1251                 spin_unlock(ptl);
1252                 return err;
1253         }
1254
1255         if (pmd_trans_unstable(pmdp))
1256                 return 0;
1257 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1258
1259         /*
1260          * We can assume that @vma always points to a valid one and @end never
1261          * goes beyond vma->vm_end.
1262          */
1263         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1264         for (; addr < end; pte++, addr += PAGE_SIZE) {
1265                 pagemap_entry_t pme;
1266
1267                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1268                 err = add_to_pagemap(addr, &pme, pm);
1269                 if (err)
1270                         break;
1271         }
1272         pte_unmap_unlock(orig_pte, ptl);
1273
1274         cond_resched();
1275
1276         return err;
1277 }
1278
1279 #ifdef CONFIG_HUGETLB_PAGE
1280 /* This function walks within one hugetlb entry in the single call */
1281 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1282                                  unsigned long addr, unsigned long end,
1283                                  struct mm_walk *walk)
1284 {
1285         struct pagemapread *pm = walk->private;
1286         struct vm_area_struct *vma = walk->vma;
1287         u64 flags = 0, frame = 0;
1288         int err = 0;
1289         pte_t pte;
1290
1291         if (vma->vm_flags & VM_SOFTDIRTY)
1292                 flags |= PM_SOFT_DIRTY;
1293
1294         pte = huge_ptep_get(ptep);
1295         if (pte_present(pte)) {
1296                 struct page *page = pte_page(pte);
1297
1298                 if (!PageAnon(page))
1299                         flags |= PM_FILE;
1300
1301                 if (page_mapcount(page) == 1)
1302                         flags |= PM_MMAP_EXCLUSIVE;
1303
1304                 flags |= PM_PRESENT;
1305                 if (pm->show_pfn)
1306                         frame = pte_pfn(pte) +
1307                                 ((addr & ~hmask) >> PAGE_SHIFT);
1308         }
1309
1310         for (; addr != end; addr += PAGE_SIZE) {
1311                 pagemap_entry_t pme = make_pme(frame, flags);
1312
1313                 err = add_to_pagemap(addr, &pme, pm);
1314                 if (err)
1315                         return err;
1316                 if (pm->show_pfn && (flags & PM_PRESENT))
1317                         frame++;
1318         }
1319
1320         cond_resched();
1321
1322         return err;
1323 }
1324 #endif /* HUGETLB_PAGE */
1325
1326 /*
1327  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1328  *
1329  * For each page in the address space, this file contains one 64-bit entry
1330  * consisting of the following:
1331  *
1332  * Bits 0-54  page frame number (PFN) if present
1333  * Bits 0-4   swap type if swapped
1334  * Bits 5-54  swap offset if swapped
1335  * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
1336  * Bit  56    page exclusively mapped
1337  * Bits 57-60 zero
1338  * Bit  61    page is file-page or shared-anon
1339  * Bit  62    page swapped
1340  * Bit  63    page present
1341  *
1342  * If the page is not present but in swap, then the PFN contains an
1343  * encoding of the swap file number and the page's offset into the
1344  * swap. Unmapped pages return a null PFN. This allows determining
1345  * precisely which pages are mapped (or in swap) and comparing mapped
1346  * pages between processes.
1347  *
1348  * Efficient users of this interface will use /proc/pid/maps to
1349  * determine which areas of memory are actually mapped and llseek to
1350  * skip over unmapped regions.
1351  */
1352 static ssize_t pagemap_read(struct file *file, char __user *buf,
1353                             size_t count, loff_t *ppos)
1354 {
1355         struct mm_struct *mm = file->private_data;
1356         struct pagemapread pm;
1357         struct mm_walk pagemap_walk = {};
1358         unsigned long src;
1359         unsigned long svpfn;
1360         unsigned long start_vaddr;
1361         unsigned long end_vaddr;
1362         int ret = 0, copied = 0;
1363
1364         if (!mm || !atomic_inc_not_zero(&mm->mm_users))
1365                 goto out;
1366
1367         ret = -EINVAL;
1368         /* file position must be aligned */
1369         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1370                 goto out_mm;
1371
1372         ret = 0;
1373         if (!count)
1374                 goto out_mm;
1375
1376         /* do not disclose physical addresses: attack vector */
1377         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1378
1379         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1380         pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
1381         ret = -ENOMEM;
1382         if (!pm.buffer)
1383                 goto out_mm;
1384
1385         pagemap_walk.pmd_entry = pagemap_pmd_range;
1386         pagemap_walk.pte_hole = pagemap_pte_hole;
1387 #ifdef CONFIG_HUGETLB_PAGE
1388         pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1389 #endif
1390         pagemap_walk.mm = mm;
1391         pagemap_walk.private = &pm;
1392
1393         src = *ppos;
1394         svpfn = src / PM_ENTRY_BYTES;
1395         start_vaddr = svpfn << PAGE_SHIFT;
1396         end_vaddr = mm->task_size;
1397
1398         /* watch out for wraparound */
1399         if (svpfn > mm->task_size >> PAGE_SHIFT)
1400                 start_vaddr = end_vaddr;
1401
1402         /*
1403          * The odds are that this will stop walking way
1404          * before end_vaddr, because the length of the
1405          * user buffer is tracked in "pm", and the walk
1406          * will stop when we hit the end of the buffer.
1407          */
1408         ret = 0;
1409         while (count && (start_vaddr < end_vaddr)) {
1410                 int len;
1411                 unsigned long end;
1412
1413                 pm.pos = 0;
1414                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1415                 /* overflow ? */
1416                 if (end < start_vaddr || end > end_vaddr)
1417                         end = end_vaddr;
1418                 down_read(&mm->mmap_sem);
1419                 ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1420                 up_read(&mm->mmap_sem);
1421                 start_vaddr = end;
1422
1423                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1424                 if (copy_to_user(buf, pm.buffer, len)) {
1425                         ret = -EFAULT;
1426                         goto out_free;
1427                 }
1428                 copied += len;
1429                 buf += len;
1430                 count -= len;
1431         }
1432         *ppos += copied;
1433         if (!ret || ret == PM_END_OF_BUFFER)
1434                 ret = copied;
1435
1436 out_free:
1437         kfree(pm.buffer);
1438 out_mm:
1439         mmput(mm);
1440 out:
1441         return ret;
1442 }
1443
1444 static int pagemap_open(struct inode *inode, struct file *file)
1445 {
1446         struct mm_struct *mm;
1447
1448         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1449         if (IS_ERR(mm))
1450                 return PTR_ERR(mm);
1451         file->private_data = mm;
1452         return 0;
1453 }
1454
1455 static int pagemap_release(struct inode *inode, struct file *file)
1456 {
1457         struct mm_struct *mm = file->private_data;
1458
1459         if (mm)
1460                 mmdrop(mm);
1461         return 0;
1462 }
1463
1464 const struct file_operations proc_pagemap_operations = {
1465         .llseek         = mem_lseek, /* borrow this */
1466         .read           = pagemap_read,
1467         .open           = pagemap_open,
1468         .release        = pagemap_release,
1469 };
1470 #endif /* CONFIG_PROC_PAGE_MONITOR */
1471
1472 #ifdef CONFIG_NUMA
1473
1474 struct numa_maps {
1475         unsigned long pages;
1476         unsigned long anon;
1477         unsigned long active;
1478         unsigned long writeback;
1479         unsigned long mapcount_max;
1480         unsigned long dirty;
1481         unsigned long swapcache;
1482         unsigned long node[MAX_NUMNODES];
1483 };
1484
1485 struct numa_maps_private {
1486         struct proc_maps_private proc_maps;
1487         struct numa_maps md;
1488 };
1489
1490 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1491                         unsigned long nr_pages)
1492 {
1493         int count = page_mapcount(page);
1494
1495         md->pages += nr_pages;
1496         if (pte_dirty || PageDirty(page))
1497                 md->dirty += nr_pages;
1498
1499         if (PageSwapCache(page))
1500                 md->swapcache += nr_pages;
1501
1502         if (PageActive(page) || PageUnevictable(page))
1503                 md->active += nr_pages;
1504
1505         if (PageWriteback(page))
1506                 md->writeback += nr_pages;
1507
1508         if (PageAnon(page))
1509                 md->anon += nr_pages;
1510
1511         if (count > md->mapcount_max)
1512                 md->mapcount_max = count;
1513
1514         md->node[page_to_nid(page)] += nr_pages;
1515 }
1516
1517 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1518                 unsigned long addr)
1519 {
1520         struct page *page;
1521         int nid;
1522
1523         if (!pte_present(pte))
1524                 return NULL;
1525
1526         page = vm_normal_page(vma, addr, pte);
1527         if (!page)
1528                 return NULL;
1529
1530         if (PageReserved(page))
1531                 return NULL;
1532
1533         nid = page_to_nid(page);
1534         if (!node_isset(nid, node_states[N_MEMORY]))
1535                 return NULL;
1536
1537         return page;
1538 }
1539
1540 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1541 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1542                                               struct vm_area_struct *vma,
1543                                               unsigned long addr)
1544 {
1545         struct page *page;
1546         int nid;
1547
1548         if (!pmd_present(pmd))
1549                 return NULL;
1550
1551         page = vm_normal_page_pmd(vma, addr, pmd);
1552         if (!page)
1553                 return NULL;
1554
1555         if (PageReserved(page))
1556                 return NULL;
1557
1558         nid = page_to_nid(page);
1559         if (!node_isset(nid, node_states[N_MEMORY]))
1560                 return NULL;
1561
1562         return page;
1563 }
1564 #endif
1565
1566 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1567                 unsigned long end, struct mm_walk *walk)
1568 {
1569         struct numa_maps *md = walk->private;
1570         struct vm_area_struct *vma = walk->vma;
1571         spinlock_t *ptl;
1572         pte_t *orig_pte;
1573         pte_t *pte;
1574
1575 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1576         ptl = pmd_trans_huge_lock(pmd, vma);
1577         if (ptl) {
1578                 struct page *page;
1579
1580                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1581                 if (page)
1582                         gather_stats(page, md, pmd_dirty(*pmd),
1583                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1584                 spin_unlock(ptl);
1585                 return 0;
1586         }
1587
1588         if (pmd_trans_unstable(pmd))
1589                 return 0;
1590 #endif
1591         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1592         do {
1593                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1594                 if (!page)
1595                         continue;
1596                 gather_stats(page, md, pte_dirty(*pte), 1);
1597
1598         } while (pte++, addr += PAGE_SIZE, addr != end);
1599         pte_unmap_unlock(orig_pte, ptl);
1600         return 0;
1601 }
1602 #ifdef CONFIG_HUGETLB_PAGE
1603 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1604                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1605 {
1606         pte_t huge_pte = huge_ptep_get(pte);
1607         struct numa_maps *md;
1608         struct page *page;
1609
1610         if (!pte_present(huge_pte))
1611                 return 0;
1612
1613         page = pte_page(huge_pte);
1614         if (!page)
1615                 return 0;
1616
1617         md = walk->private;
1618         gather_stats(page, md, pte_dirty(huge_pte), 1);
1619         return 0;
1620 }
1621
1622 #else
1623 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1624                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1625 {
1626         return 0;
1627 }
1628 #endif
1629
1630 /*
1631  * Display pages allocated per node and memory policy via /proc.
1632  */
1633 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1634 {
1635         struct numa_maps_private *numa_priv = m->private;
1636         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1637         struct vm_area_struct *vma = v;
1638         struct numa_maps *md = &numa_priv->md;
1639         struct file *file = vma->vm_file;
1640         struct mm_struct *mm = vma->vm_mm;
1641         struct mm_walk walk = {
1642                 .hugetlb_entry = gather_hugetlb_stats,
1643                 .pmd_entry = gather_pte_stats,
1644                 .private = md,
1645                 .mm = mm,
1646         };
1647         struct mempolicy *pol;
1648         char buffer[64];
1649         int nid;
1650
1651         if (!mm)
1652                 return 0;
1653
1654         /* Ensure we start with an empty set of numa_maps statistics. */
1655         memset(md, 0, sizeof(*md));
1656
1657         pol = __get_vma_policy(vma, vma->vm_start);
1658         if (pol) {
1659                 mpol_to_str(buffer, sizeof(buffer), pol);
1660                 mpol_cond_put(pol);
1661         } else {
1662                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1663         }
1664
1665         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1666
1667         if (file) {
1668                 seq_puts(m, " file=");
1669                 seq_file_path(m, file, "\n\t= ");
1670         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1671                 seq_puts(m, " heap");
1672         } else if (is_stack(proc_priv, vma, is_pid)) {
1673                 seq_puts(m, " stack");
1674         }
1675
1676         if (is_vm_hugetlb_page(vma))
1677                 seq_puts(m, " huge");
1678
1679         /* mmap_sem is held by m_start */
1680         walk_page_vma(vma, &walk);
1681
1682         if (!md->pages)
1683                 goto out;
1684
1685         if (md->anon)
1686                 seq_printf(m, " anon=%lu", md->anon);
1687
1688         if (md->dirty)
1689                 seq_printf(m, " dirty=%lu", md->dirty);
1690
1691         if (md->pages != md->anon && md->pages != md->dirty)
1692                 seq_printf(m, " mapped=%lu", md->pages);
1693
1694         if (md->mapcount_max > 1)
1695                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1696
1697         if (md->swapcache)
1698                 seq_printf(m, " swapcache=%lu", md->swapcache);
1699
1700         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1701                 seq_printf(m, " active=%lu", md->active);
1702
1703         if (md->writeback)
1704                 seq_printf(m, " writeback=%lu", md->writeback);
1705
1706         for_each_node_state(nid, N_MEMORY)
1707                 if (md->node[nid])
1708                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1709
1710         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1711 out:
1712         seq_putc(m, '\n');
1713         m_cache_vma(m, vma);
1714         return 0;
1715 }
1716
1717 static int show_pid_numa_map(struct seq_file *m, void *v)
1718 {
1719         return show_numa_map(m, v, 1);
1720 }
1721
1722 static int show_tid_numa_map(struct seq_file *m, void *v)
1723 {
1724         return show_numa_map(m, v, 0);
1725 }
1726
1727 static const struct seq_operations proc_pid_numa_maps_op = {
1728         .start  = m_start,
1729         .next   = m_next,
1730         .stop   = m_stop,
1731         .show   = show_pid_numa_map,
1732 };
1733
1734 static const struct seq_operations proc_tid_numa_maps_op = {
1735         .start  = m_start,
1736         .next   = m_next,
1737         .stop   = m_stop,
1738         .show   = show_tid_numa_map,
1739 };
1740
1741 static int numa_maps_open(struct inode *inode, struct file *file,
1742                           const struct seq_operations *ops)
1743 {
1744         return proc_maps_open(inode, file, ops,
1745                                 sizeof(struct numa_maps_private));
1746 }
1747
1748 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1749 {
1750         return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1751 }
1752
1753 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1754 {
1755         return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1756 }
1757
1758 const struct file_operations proc_pid_numa_maps_operations = {
1759         .open           = pid_numa_maps_open,
1760         .read           = seq_read,
1761         .llseek         = seq_lseek,
1762         .release        = proc_map_release,
1763 };
1764
1765 const struct file_operations proc_tid_numa_maps_operations = {
1766         .open           = tid_numa_maps_open,
1767         .read           = seq_read,
1768         .llseek         = seq_lseek,
1769         .release        = proc_map_release,
1770 };
1771 #endif /* CONFIG_NUMA */