fs/proc/task_mmu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/mm.h>
   3 #include <linux/vmacache.h>
   4 #include <linux/hugetlb.h>
   5 #include <linux/huge_mm.h>
   6 #include <linux/mount.h>
   7 #include <linux/seq_file.h>
   8 #include <linux/highmem.h>
   9 #include <linux/ptrace.h>
  10 #include <linux/slab.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/mempolicy.h>
  13 #include <linux/rmap.h>
  14 #include <linux/swap.h>
  15 #include <linux/sched/mm.h>
  16 #include <linux/swapops.h>
  17 #include <linux/mmu_notifier.h>
  18 #include <linux/page_idle.h>
  19 #include <linux/shmem_fs.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/pkeys.h>
  22
  23 #include <asm/elf.h>
  24 #include <asm/tlb.h>
  25 #include <asm/tlbflush.h>
  26 #include "internal.h"
  27
  28 #define SEQ_PUT_DEC(str, val) \
  29                 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
  30 void task_mem(struct seq_file *m, struct mm_struct *mm)
  31 {
  32         unsigned long text, lib, swap, anon, file, shmem;
  33         unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  34
  35         anon = get_mm_counter(mm, MM_ANONPAGES);
  36         file = get_mm_counter(mm, MM_FILEPAGES);
  37         shmem = get_mm_counter(mm, MM_SHMEMPAGES);
  38
  39         /*
  40          * Note: to minimize their overhead, mm maintains hiwater_vm and
  41          * hiwater_rss only when about to *lower* total_vm or rss.  Any
  42          * collector of these hiwater stats must therefore get total_vm
  43          * and rss too, which will usually be the higher.  Barriers? not
  44          * worth the effort, such snapshots can always be inconsistent.
  45          */
  46         hiwater_vm = total_vm = mm->total_vm;
  47         if (hiwater_vm < mm->hiwater_vm)
  48                 hiwater_vm = mm->hiwater_vm;
  49         hiwater_rss = total_rss = anon + file + shmem;
  50         if (hiwater_rss < mm->hiwater_rss)
  51                 hiwater_rss = mm->hiwater_rss;
  52
  53         /* split executable areas between text and lib */
  54         text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
  55         text = min(text, mm->exec_vm << PAGE_SHIFT);
  56         lib = (mm->exec_vm << PAGE_SHIFT) - text;
  57
  58         swap = get_mm_counter(mm, MM_SWAPENTS);
  59         SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
  60         SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
  61         SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
  62         SEQ_PUT_DEC(" kB\nVmPin:\t", mm->pinned_vm);
  63         SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
  64         SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
  65         SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
  66         SEQ_PUT_DEC(" kB\nRssFile:\t", file);
  67         SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
  68         SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
  69         SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
  70         seq_put_decimal_ull_width(m,
  71                     " kB\nVmExe:\t", text >> 10, 8);
  72         seq_put_decimal_ull_width(m,
  73                     " kB\nVmLib:\t", lib >> 10, 8);
  74         seq_put_decimal_ull_width(m,
  75                     " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
  76         SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
  77         seq_puts(m, " kB\n");
  78         hugetlb_report_usage(m, mm);
  79 }
  80 #undef SEQ_PUT_DEC
  81
  82 unsigned long task_vsize(struct mm_struct *mm)
  83 {
  84         return PAGE_SIZE * mm->total_vm;
  85 }
  86
  87 unsigned long task_statm(struct mm_struct *mm,
  88                          unsigned long *shared, unsigned long *text,
  89                          unsigned long *data, unsigned long *resident)
  90 {
  91         *shared = get_mm_counter(mm, MM_FILEPAGES) +
  92                         get_mm_counter(mm, MM_SHMEMPAGES);
  93         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  94                                                                 >> PAGE_SHIFT;
  95         *data = mm->data_vm + mm->stack_vm;
  96         *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
  97         return mm->total_vm;
  98 }
  99
 100 #ifdef CONFIG_NUMA
 101 /*
 102  * Save get_task_policy() for show_numa_map().
 103  */
 104 static void hold_task_mempolicy(struct proc_maps_private *priv)
 105 {
 106         struct task_struct *task = priv->task;
 107
 108         task_lock(task);
 109         priv->task_mempolicy = get_task_policy(task);
 110         mpol_get(priv->task_mempolicy);
 111         task_unlock(task);
 112 }
 113 static void release_task_mempolicy(struct proc_maps_private *priv)
 114 {
 115         mpol_put(priv->task_mempolicy);
 116 }
 117 #else
 118 static void hold_task_mempolicy(struct proc_maps_private *priv)
 119 {
 120 }
 121 static void release_task_mempolicy(struct proc_maps_private *priv)
 122 {
 123 }
 124 #endif
 125
 126 static void vma_stop(struct proc_maps_private *priv)
 127 {
 128         struct mm_struct *mm = priv->mm;
 129
 130         release_task_mempolicy(priv);
 131         up_read(&mm->mmap_sem);
 132         mmput(mm);
 133 }
 134
 135 static struct vm_area_struct *
 136 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
 137 {
 138         if (vma == priv->tail_vma)
 139                 return NULL;
 140         return vma->vm_next ?: priv->tail_vma;
 141 }
 142
 143 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
 144 {
 145         if (m->count < m->size) /* vma is copied successfully */
 146                 m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;
 147 }
 148
 149 static void *m_start(struct seq_file *m, loff_t *ppos)
 150 {
 151         struct proc_maps_private *priv = m->private;
 152         unsigned long last_addr = m->version;
 153         struct mm_struct *mm;
 154         struct vm_area_struct *vma;
 155         unsigned int pos = *ppos;
 156
 157         /* See m_cache_vma(). Zero at the start or after lseek. */
 158         if (last_addr == -1UL)
 159                 return NULL;
 160
 161         priv->task = get_proc_task(priv->inode);
 162         if (!priv->task)
 163                 return ERR_PTR(-ESRCH);
 164
 165         mm = priv->mm;
 166         if (!mm || !mmget_not_zero(mm))
 167                 return NULL;
 168
 169         down_read(&mm->mmap_sem);
 170         hold_task_mempolicy(priv);
 171         priv->tail_vma = get_gate_vma(mm);
 172
 173         if (last_addr) {
 174                 vma = find_vma(mm, last_addr - 1);
 175                 if (vma && vma->vm_start <= last_addr)
 176                         vma = m_next_vma(priv, vma);
 177                 if (vma)
 178                         return vma;
 179         }
 180
 181         m->version = 0;
 182         if (pos < mm->map_count) {
 183                 for (vma = mm->mmap; pos; pos--) {
 184                         m->version = vma->vm_start;
 185                         vma = vma->vm_next;
 186                 }
 187                 return vma;
 188         }
 189
 190         /* we do not bother to update m->version in this case */
 191         if (pos == mm->map_count && priv->tail_vma)
 192                 return priv->tail_vma;
 193
 194         vma_stop(priv);
 195         return NULL;
 196 }
 197
 198 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 199 {
 200         struct proc_maps_private *priv = m->private;
 201         struct vm_area_struct *next;
 202
 203         (*pos)++;
 204         next = m_next_vma(priv, v);
 205         if (!next)
 206                 vma_stop(priv);
 207         return next;
 208 }
 209
 210 static void m_stop(struct seq_file *m, void *v)
 211 {
 212         struct proc_maps_private *priv = m->private;
 213
 214         if (!IS_ERR_OR_NULL(v))
 215                 vma_stop(priv);
 216         if (priv->task) {
 217                 put_task_struct(priv->task);
 218                 priv->task = NULL;
 219         }
 220 }
 221
 222 static int proc_maps_open(struct inode *inode, struct file *file,
 223                         const struct seq_operations *ops, int psize)
 224 {
 225         struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
 226
 227         if (!priv)
 228                 return -ENOMEM;
 229
 230         priv->inode = inode;
 231         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 232         if (IS_ERR(priv->mm)) {
 233                 int err = PTR_ERR(priv->mm);
 234
 235                 seq_release_private(inode, file);
 236                 return err;
 237         }
 238
 239         return 0;
 240 }
 241
 242 static int proc_map_release(struct inode *inode, struct file *file)
 243 {
 244         struct seq_file *seq = file->private_data;
 245         struct proc_maps_private *priv = seq->private;
 246
 247         if (priv->mm)
 248                 mmdrop(priv->mm);
 249
 250         kfree(priv->rollup);
 251         return seq_release_private(inode, file);
 252 }
 253
 254 static int do_maps_open(struct inode *inode, struct file *file,
 255                         const struct seq_operations *ops)
 256 {
 257         return proc_maps_open(inode, file, ops,
 258                                 sizeof(struct proc_maps_private));
 259 }
 260
 261 /*
 262  * Indicate if the VMA is a stack for the given task; for
 263  * /proc/PID/maps that is the stack of the main task.
 264  */
 265 static int is_stack(struct vm_area_struct *vma)
 266 {
 267         /*
 268          * We make no effort to guess what a given thread considers to be
 269          * its "stack".  It's not even well-defined for programs written
 270          * languages like Go.
 271          */
 272         return vma->vm_start <= vma->vm_mm->start_stack &&
 273                 vma->vm_end >= vma->vm_mm->start_stack;
 274 }
 275
 276 static void show_vma_header_prefix(struct seq_file *m,
 277                                    unsigned long start, unsigned long end,
 278                                    vm_flags_t flags, unsigned long long pgoff,
 279                                    dev_t dev, unsigned long ino)
 280 {
 281         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 282         seq_put_hex_ll(m, NULL, start, 8);
 283         seq_put_hex_ll(m, "-", end, 8);
 284         seq_putc(m, ' ');
 285         seq_putc(m, flags & VM_READ ? 'r' : '-');
 286         seq_putc(m, flags & VM_WRITE ? 'w' : '-');
 287         seq_putc(m, flags & VM_EXEC ? 'x' : '-');
 288         seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
 289         seq_put_hex_ll(m, " ", pgoff, 8);
 290         seq_put_hex_ll(m, " ", MAJOR(dev), 2);
 291         seq_put_hex_ll(m, ":", MINOR(dev), 2);
 292         seq_put_decimal_ull(m, " ", ino);
 293         seq_putc(m, ' ');
 294 }
 295
 296 static void
 297 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 298 {
 299         struct mm_struct *mm = vma->vm_mm;
 300         struct file *file = vma->vm_file;
 301         vm_flags_t flags = vma->vm_flags;
 302         unsigned long ino = 0;
 303         unsigned long long pgoff = 0;
 304         unsigned long start, end;
 305         dev_t dev = 0;
 306         const char *name = NULL;
 307
 308         if (file) {
 309                 struct inode *inode = file_inode(vma->vm_file);
 310                 dev = inode->i_sb->s_dev;
 311                 ino = inode->i_ino;
 312                 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 313         }
 314
 315         start = vma->vm_start;
 316         end = vma->vm_end;
 317         show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
 318
 319         /*
 320          * Print the dentry name for named mappings, and a
 321          * special [heap] marker for the heap:
 322          */
 323         if (file) {
 324                 seq_pad(m, ' ');
 325                 seq_file_path(m, file, "\n");
 326                 goto done;
 327         }
 328
 329         if (vma->vm_ops && vma->vm_ops->name) {
 330                 name = vma->vm_ops->name(vma);
 331                 if (name)
 332                         goto done;
 333         }
 334
 335         name = arch_vma_name(vma);
 336         if (!name) {
 337                 if (!mm) {
 338                         name = "[vdso]";
 339                         goto done;
 340                 }
 341
 342                 if (vma->vm_start <= mm->brk &&
 343                     vma->vm_end >= mm->start_brk) {
 344                         name = "[heap]";
 345                         goto done;
 346                 }
 347
 348                 if (is_stack(vma))
 349                         name = "[stack]";
 350         }
 351
 352 done:
 353         if (name) {
 354                 seq_pad(m, ' ');
 355                 seq_puts(m, name);
 356         }
 357         seq_putc(m, '\n');
 358 }
 359
 360 static int show_map(struct seq_file *m, void *v, int is_pid)
 361 {
 362         show_map_vma(m, v, is_pid);
 363         m_cache_vma(m, v);
 364         return 0;
 365 }
 366
 367 static int show_pid_map(struct seq_file *m, void *v)
 368 {
 369         return show_map(m, v, 1);
 370 }
 371
 372 static int show_tid_map(struct seq_file *m, void *v)
 373 {
 374         return show_map(m, v, 0);
 375 }
 376
 377 static const struct seq_operations proc_pid_maps_op = {
 378         .start  = m_start,
 379         .next   = m_next,
 380         .stop   = m_stop,
 381         .show   = show_pid_map
 382 };
 383
 384 static const struct seq_operations proc_tid_maps_op = {
 385         .start  = m_start,
 386         .next   = m_next,
 387         .stop   = m_stop,
 388         .show   = show_tid_map
 389 };
 390
 391 static int pid_maps_open(struct inode *inode, struct file *file)
 392 {
 393         return do_maps_open(inode, file, &proc_pid_maps_op);
 394 }
 395
 396 static int tid_maps_open(struct inode *inode, struct file *file)
 397 {
 398         return do_maps_open(inode, file, &proc_tid_maps_op);
 399 }
 400
 401 const struct file_operations proc_pid_maps_operations = {
 402         .open           = pid_maps_open,
 403         .read           = seq_read,
 404         .llseek         = seq_lseek,
 405         .release        = proc_map_release,
 406 };
 407
 408 const struct file_operations proc_tid_maps_operations = {
 409         .open           = tid_maps_open,
 410         .read           = seq_read,
 411         .llseek         = seq_lseek,
 412         .release        = proc_map_release,
 413 };
 414
 415 /*
 416  * Proportional Set Size(PSS): my share of RSS.
 417  *
 418  * PSS of a process is the count of pages it has in memory, where each
 419  * page is divided by the number of processes sharing it.  So if a
 420  * process has 1000 pages all to itself, and 1000 shared with one other
 421  * process, its PSS will be 1500.
 422  *
 423  * To keep (accumulated) division errors low, we adopt a 64bit
 424  * fixed-point pss counter to minimize division errors. So (pss >>
 425  * PSS_SHIFT) would be the real byte count.
 426  *
 427  * A shift of 12 before division means (assuming 4K page size):
 428  *      - 1M 3-user-pages add up to 8KB errors;
 429  *      - supports mapcount up to 2^24, or 16M;
 430  *      - supports PSS up to 2^52 bytes, or 4PB.
 431  */
 432 #define PSS_SHIFT 12
 433
 434 #ifdef CONFIG_PROC_PAGE_MONITOR
 435 struct mem_size_stats {
 436         bool first;
 437         unsigned long resident;
 438         unsigned long shared_clean;
 439         unsigned long shared_dirty;
 440         unsigned long private_clean;
 441         unsigned long private_dirty;
 442         unsigned long referenced;
 443         unsigned long anonymous;
 444         unsigned long lazyfree;
 445         unsigned long anonymous_thp;
 446         unsigned long shmem_thp;
 447         unsigned long swap;
 448         unsigned long shared_hugetlb;
 449         unsigned long private_hugetlb;
 450         unsigned long first_vma_start;
 451         u64 pss;
 452         u64 pss_locked;
 453         u64 swap_pss;
 454         bool check_shmem_swap;
 455 };
 456
 457 static void smaps_account(struct mem_size_stats *mss, struct page *page,
 458                 bool compound, bool young, bool dirty)
 459 {
 460         int i, nr = compound ? 1 << compound_order(page) : 1;
 461         unsigned long size = nr * PAGE_SIZE;
 462
 463         if (PageAnon(page)) {
 464                 mss->anonymous += size;
 465                 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
 466                         mss->lazyfree += size;
 467         }
 468
 469         mss->resident += size;
 470         /* Accumulate the size in pages that have been accessed. */
 471         if (young || page_is_young(page) || PageReferenced(page))
 472                 mss->referenced += size;
 473
 474         /*
 475          * page_count(page) == 1 guarantees the page is mapped exactly once.
 476          * If any subpage of the compound page mapped with PTE it would elevate
 477          * page_count().
 478          */
 479         if (page_count(page) == 1) {
 480                 if (dirty || PageDirty(page))
 481                         mss->private_dirty += size;
 482                 else
 483                         mss->private_clean += size;
 484                 mss->pss += (u64)size << PSS_SHIFT;
 485                 return;
 486         }
 487
 488         for (i = 0; i < nr; i++, page++) {
 489                 int mapcount = page_mapcount(page);
 490
 491                 if (mapcount >= 2) {
 492                         if (dirty || PageDirty(page))
 493                                 mss->shared_dirty += PAGE_SIZE;
 494                         else
 495                                 mss->shared_clean += PAGE_SIZE;
 496                         mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
 497                 } else {
 498                         if (dirty || PageDirty(page))
 499                                 mss->private_dirty += PAGE_SIZE;
 500                         else
 501                                 mss->private_clean += PAGE_SIZE;
 502                         mss->pss += PAGE_SIZE << PSS_SHIFT;
 503                 }
 504         }
 505 }
 506
 507 #ifdef CONFIG_SHMEM
 508 static int smaps_pte_hole(unsigned long addr, unsigned long end,
 509                 struct mm_walk *walk)
 510 {
 511         struct mem_size_stats *mss = walk->private;
 512
 513         mss->swap += shmem_partial_swap_usage(
 514                         walk->vma->vm_file->f_mapping, addr, end);
 515
 516         return 0;
 517 }
 518 #endif
 519
 520 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 521                 struct mm_walk *walk)
 522 {
 523         struct mem_size_stats *mss = walk->private;
 524         struct vm_area_struct *vma = walk->vma;
 525         struct page *page = NULL;
 526
 527         if (pte_present(*pte)) {
 528                 page = vm_normal_page(vma, addr, *pte);
 529         } else if (is_swap_pte(*pte)) {
 530                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 531
 532                 if (!non_swap_entry(swpent)) {
 533                         int mapcount;
 534
 535                         mss->swap += PAGE_SIZE;
 536                         mapcount = swp_swapcount(swpent);
 537                         if (mapcount >= 2) {
 538                                 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
 539
 540                                 do_div(pss_delta, mapcount);
 541                                 mss->swap_pss += pss_delta;
 542                         } else {
 543                                 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
 544                         }
 545                 } else if (is_migration_entry(swpent))
 546                         page = migration_entry_to_page(swpent);
 547                 else if (is_device_private_entry(swpent))
 548                         page = device_private_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                 if (pmd_present(*pmd))
 609                         smaps_pmd_entry(pmd, addr, walk);
 610                 spin_unlock(ptl);
 611                 goto out;
 612         }
 613
 614         if (pmd_trans_unstable(pmd))
 615                 goto out;
 616         /*
 617          * The mmap_sem held all the way back in m_start() is what
 618          * keeps khugepaged out of here and from collapsing things
 619          * in here.
 620          */
 621         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 622         for (; addr != end; pte++, addr += PAGE_SIZE)
 623                 smaps_pte_entry(pte, addr, walk);
 624         pte_unmap_unlock(pte - 1, ptl);
 625 out:
 626         cond_resched();
 627         return 0;
 628 }
 629
 630 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 631 {
 632         /*
 633          * Don't forget to update Documentation/ on changes.
 634          */
 635         static const char mnemonics[BITS_PER_LONG][2] = {
 636                 /*
 637                  * In case if we meet a flag we don't know about.
 638                  */
 639                 [0 ... (BITS_PER_LONG-1)] = "??",
 640
 641                 [ilog2(VM_READ)]        = "rd",
 642                 [ilog2(VM_WRITE)]       = "wr",
 643                 [ilog2(VM_EXEC)]        = "ex",
 644                 [ilog2(VM_SHARED)]      = "sh",
 645                 [ilog2(VM_MAYREAD)]     = "mr",
 646                 [ilog2(VM_MAYWRITE)]    = "mw",
 647                 [ilog2(VM_MAYEXEC)]     = "me",
 648                 [ilog2(VM_MAYSHARE)]    = "ms",
 649                 [ilog2(VM_GROWSDOWN)]   = "gd",
 650                 [ilog2(VM_PFNMAP)]      = "pf",
 651                 [ilog2(VM_DENYWRITE)]   = "dw",
 652 #ifdef CONFIG_X86_INTEL_MPX
 653                 [ilog2(VM_MPX)]         = "mp",
 654 #endif
 655                 [ilog2(VM_LOCKED)]      = "lo",
 656                 [ilog2(VM_IO)]          = "io",
 657                 [ilog2(VM_SEQ_READ)]    = "sr",
 658                 [ilog2(VM_RAND_READ)]   = "rr",
 659                 [ilog2(VM_DONTCOPY)]    = "dc",
 660                 [ilog2(VM_DONTEXPAND)]  = "de",
 661                 [ilog2(VM_ACCOUNT)]     = "ac",
 662                 [ilog2(VM_NORESERVE)]   = "nr",
 663                 [ilog2(VM_HUGETLB)]     = "ht",
 664                 [ilog2(VM_SYNC)]        = "sf",
 665                 [ilog2(VM_ARCH_1)]      = "ar",
 666                 [ilog2(VM_WIPEONFORK)]  = "wf",
 667                 [ilog2(VM_DONTDUMP)]    = "dd",
 668 #ifdef CONFIG_MEM_SOFT_DIRTY
 669                 [ilog2(VM_SOFTDIRTY)]   = "sd",
 670 #endif
 671                 [ilog2(VM_MIXEDMAP)]    = "mm",
 672                 [ilog2(VM_HUGEPAGE)]    = "hg",
 673                 [ilog2(VM_NOHUGEPAGE)]  = "nh",
 674                 [ilog2(VM_MERGEABLE)]   = "mg",
 675                 [ilog2(VM_UFFD_MISSING)]= "um",
 676                 [ilog2(VM_UFFD_WP)]     = "uw",
 677 #ifdef CONFIG_ARCH_HAS_PKEYS
 678                 /* These come out via ProtectionKey: */
 679                 [ilog2(VM_PKEY_BIT0)]   = "",
 680                 [ilog2(VM_PKEY_BIT1)]   = "",
 681                 [ilog2(VM_PKEY_BIT2)]   = "",
 682                 [ilog2(VM_PKEY_BIT3)]   = "",
 683 #if VM_PKEY_BIT4
 684                 [ilog2(VM_PKEY_BIT4)]   = "",
 685 #endif
 686 #endif /* CONFIG_ARCH_HAS_PKEYS */
 687         };
 688         size_t i;
 689
 690         seq_puts(m, "VmFlags: ");
 691         for (i = 0; i < BITS_PER_LONG; i++) {
 692                 if (!mnemonics[i][0])
 693                         continue;
 694                 if (vma->vm_flags & (1UL << i)) {
 695                         seq_putc(m, mnemonics[i][0]);
 696                         seq_putc(m, mnemonics[i][1]);
 697                         seq_putc(m, ' ');
 698                 }
 699         }
 700         seq_putc(m, '\n');
 701 }
 702
 703 #ifdef CONFIG_HUGETLB_PAGE
 704 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 705                                  unsigned long addr, unsigned long end,
 706                                  struct mm_walk *walk)
 707 {
 708         struct mem_size_stats *mss = walk->private;
 709         struct vm_area_struct *vma = walk->vma;
 710         struct page *page = NULL;
 711
 712         if (pte_present(*pte)) {
 713                 page = vm_normal_page(vma, addr, *pte);
 714         } else if (is_swap_pte(*pte)) {
 715                 swp_entry_t swpent = pte_to_swp_entry(*pte);
 716
 717                 if (is_migration_entry(swpent))
 718                         page = migration_entry_to_page(swpent);
 719                 else if (is_device_private_entry(swpent))
 720                         page = device_private_entry_to_page(swpent);
 721         }
 722         if (page) {
 723                 int mapcount = page_mapcount(page);
 724
 725                 if (mapcount >= 2)
 726                         mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
 727                 else
 728                         mss->private_hugetlb += huge_page_size(hstate_vma(vma));
 729         }
 730         return 0;
 731 }
 732 #endif /* HUGETLB_PAGE */
 733
 734 #define SEQ_PUT_DEC(str, val) \
 735                 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
 736 static int show_smap(struct seq_file *m, void *v, int is_pid)
 737 {
 738         struct proc_maps_private *priv = m->private;
 739         struct vm_area_struct *vma = v;
 740         struct mem_size_stats mss_stack;
 741         struct mem_size_stats *mss;
 742         struct mm_walk smaps_walk = {
 743                 .pmd_entry = smaps_pte_range,
 744 #ifdef CONFIG_HUGETLB_PAGE
 745                 .hugetlb_entry = smaps_hugetlb_range,
 746 #endif
 747                 .mm = vma->vm_mm,
 748         };
 749         int ret = 0;
 750         bool rollup_mode;
 751         bool last_vma;
 752
 753         if (priv->rollup) {
 754                 rollup_mode = true;
 755                 mss = priv->rollup;
 756                 if (mss->first) {
 757                         mss->first_vma_start = vma->vm_start;
 758                         mss->first = false;
 759                 }
 760                 last_vma = !m_next_vma(priv, vma);
 761         } else {
 762                 rollup_mode = false;
 763                 memset(&mss_stack, 0, sizeof(mss_stack));
 764                 mss = &mss_stack;
 765         }
 766
 767         smaps_walk.private = mss;
 768
 769 #ifdef CONFIG_SHMEM
 770         if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
 771                 /*
 772                  * For shared or readonly shmem mappings we know that all
 773                  * swapped out pages belong to the shmem object, and we can
 774                  * obtain the swap value much more efficiently. For private
 775                  * writable mappings, we might have COW pages that are
 776                  * not affected by the parent swapped out pages of the shmem
 777                  * object, so we have to distinguish them during the page walk.
 778                  * Unless we know that the shmem object (or the part mapped by
 779                  * our VMA) has no swapped out pages at all.
 780                  */
 781                 unsigned long shmem_swapped = shmem_swap_usage(vma);
 782
 783                 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
 784                                         !(vma->vm_flags & VM_WRITE)) {
 785                         mss->swap = shmem_swapped;
 786                 } else {
 787                         mss->check_shmem_swap = true;
 788                         smaps_walk.pte_hole = smaps_pte_hole;
 789                 }
 790         }
 791 #endif
 792
 793         /* mmap_sem is held in m_start */
 794         walk_page_vma(vma, &smaps_walk);
 795         if (vma->vm_flags & VM_LOCKED)
 796                 mss->pss_locked += mss->pss;
 797
 798         if (!rollup_mode) {
 799                 show_map_vma(m, vma, is_pid);
 800         } else if (last_vma) {
 801                 show_vma_header_prefix(
 802                         m, mss->first_vma_start, vma->vm_end, 0, 0, 0, 0);
 803                 seq_pad(m, ' ');
 804                 seq_puts(m, "[rollup]\n");
 805         } else {
 806                 ret = SEQ_SKIP;
 807         }
 808
 809         if (!rollup_mode) {
 810                 SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
 811                 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
 812                 SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
 813                 seq_puts(m, " kB\n");
 814         }
 815
 816         if (!rollup_mode || last_vma) {
 817                 SEQ_PUT_DEC("Rss:            ", mss->resident);
 818                 SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
 819                 SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
 820                 SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
 821                 SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
 822                 SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
 823                 SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
 824                 SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
 825                 SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
 826                 SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
 827                 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
 828                 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
 829                 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
 830                                           mss->private_hugetlb >> 10, 7);
 831                 SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
 832                 SEQ_PUT_DEC(" kB\nSwapPss:        ",
 833                                                 mss->swap_pss >> PSS_SHIFT);
 834                 SEQ_PUT_DEC(" kB\nLocked:         ",
 835                                                 mss->pss_locked >> PSS_SHIFT);
 836                 seq_puts(m, " kB\n");
 837         }
 838         if (!rollup_mode) {
 839                 if (arch_pkeys_enabled())
 840                         seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
 841                 show_smap_vma_flags(m, vma);
 842         }
 843         m_cache_vma(m, vma);
 844         return ret;
 845 }
 846 #undef SEQ_PUT_DEC
 847
 848 static int show_pid_smap(struct seq_file *m, void *v)
 849 {
 850         return show_smap(m, v, 1);
 851 }
 852
 853 static int show_tid_smap(struct seq_file *m, void *v)
 854 {
 855         return show_smap(m, v, 0);
 856 }
 857
 858 static const struct seq_operations proc_pid_smaps_op = {
 859         .start  = m_start,
 860         .next   = m_next,
 861         .stop   = m_stop,
 862         .show   = show_pid_smap
 863 };
 864
 865 static const struct seq_operations proc_tid_smaps_op = {
 866         .start  = m_start,
 867         .next   = m_next,
 868         .stop   = m_stop,
 869         .show   = show_tid_smap
 870 };
 871
 872 static int pid_smaps_open(struct inode *inode, struct file *file)
 873 {
 874         return do_maps_open(inode, file, &proc_pid_smaps_op);
 875 }
 876
 877 static int pid_smaps_rollup_open(struct inode *inode, struct file *file)
 878 {
 879         struct seq_file *seq;
 880         struct proc_maps_private *priv;
 881         int ret = do_maps_open(inode, file, &proc_pid_smaps_op);
 882
 883         if (ret < 0)
 884                 return ret;
 885         seq = file->private_data;
 886         priv = seq->private;
 887         priv->rollup = kzalloc(sizeof(*priv->rollup), GFP_KERNEL);
 888         if (!priv->rollup) {
 889                 proc_map_release(inode, file);
 890                 return -ENOMEM;
 891         }
 892         priv->rollup->first = true;
 893         return 0;
 894 }
 895
 896 static int tid_smaps_open(struct inode *inode, struct file *file)
 897 {
 898         return do_maps_open(inode, file, &proc_tid_smaps_op);
 899 }
 900
 901 const struct file_operations proc_pid_smaps_operations = {
 902         .open           = pid_smaps_open,
 903         .read           = seq_read,
 904         .llseek         = seq_lseek,
 905         .release        = proc_map_release,
 906 };
 907
 908 const struct file_operations proc_pid_smaps_rollup_operations = {
 909         .open           = pid_smaps_rollup_open,
 910         .read           = seq_read,
 911         .llseek         = seq_lseek,
 912         .release        = proc_map_release,
 913 };
 914
 915 const struct file_operations proc_tid_smaps_operations = {
 916         .open           = tid_smaps_open,
 917         .read           = seq_read,
 918         .llseek         = seq_lseek,
 919         .release        = proc_map_release,
 920 };
 921
 922 enum clear_refs_types {
 923         CLEAR_REFS_ALL = 1,
 924         CLEAR_REFS_ANON,
 925         CLEAR_REFS_MAPPED,
 926         CLEAR_REFS_SOFT_DIRTY,
 927         CLEAR_REFS_MM_HIWATER_RSS,
 928         CLEAR_REFS_LAST,
 929 };
 930
 931 struct clear_refs_private {
 932         enum clear_refs_types type;
 933 };
 934
 935 #ifdef CONFIG_MEM_SOFT_DIRTY
 936 static inline void clear_soft_dirty(struct vm_area_struct *vma,
 937                 unsigned long addr, pte_t *pte)
 938 {
 939         /*
 940          * The soft-dirty tracker uses #PF-s to catch writes
 941          * to pages, so write-protect the pte as well. See the
 942          * Documentation/admin-guide/mm/soft-dirty.rst for full description
 943          * of how soft-dirty works.
 944          */
 945         pte_t ptent = *pte;
 946
 947         if (pte_present(ptent)) {
 948                 ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
 949                 ptent = pte_wrprotect(ptent);
 950                 ptent = pte_clear_soft_dirty(ptent);
 951                 ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
 952         } else if (is_swap_pte(ptent)) {
 953                 ptent = pte_swp_clear_soft_dirty(ptent);
 954                 set_pte_at(vma->vm_mm, addr, pte, ptent);
 955         }
 956 }
 957 #else
 958 static inline void clear_soft_dirty(struct vm_area_struct *vma,
 959                 unsigned long addr, pte_t *pte)
 960 {
 961 }
 962 #endif
 963
 964 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 965 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 966                 unsigned long addr, pmd_t *pmdp)
 967 {
 968         pmd_t old, pmd = *pmdp;
 969
 970         if (pmd_present(pmd)) {
 971                 /* See comment in change_huge_pmd() */
 972                 old = pmdp_invalidate(vma, addr, pmdp);
 973                 if (pmd_dirty(old))
 974                         pmd = pmd_mkdirty(pmd);
 975                 if (pmd_young(old))
 976                         pmd = pmd_mkyoung(pmd);
 977
 978                 pmd = pmd_wrprotect(pmd);
 979                 pmd = pmd_clear_soft_dirty(pmd);
 980
 981                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
 982         } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
 983                 pmd = pmd_swp_clear_soft_dirty(pmd);
 984                 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
 985         }
 986 }
 987 #else
 988 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 989                 unsigned long addr, pmd_t *pmdp)
 990 {
 991 }
 992 #endif
 993
 994 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 995                                 unsigned long end, struct mm_walk *walk)
 996 {
 997         struct clear_refs_private *cp = walk->private;
 998         struct vm_area_struct *vma = walk->vma;
 999         pte_t *pte, ptent;
1000         spinlock_t *ptl;
1001         struct page *page;
1002
1003         ptl = pmd_trans_huge_lock(pmd, vma);
1004         if (ptl) {
1005                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1006                         clear_soft_dirty_pmd(vma, addr, pmd);
1007                         goto out;
1008                 }
1009
1010                 if (!pmd_present(*pmd))
1011                         goto out;
1012
1013                 page = pmd_page(*pmd);
1014
1015                 /* Clear accessed and referenced bits. */
1016                 pmdp_test_and_clear_young(vma, addr, pmd);
1017                 test_and_clear_page_young(page);
1018                 ClearPageReferenced(page);
1019 out:
1020                 spin_unlock(ptl);
1021                 return 0;
1022         }
1023
1024         if (pmd_trans_unstable(pmd))
1025                 return 0;
1026
1027         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1028         for (; addr != end; pte++, addr += PAGE_SIZE) {
1029                 ptent = *pte;
1030
1031                 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1032                         clear_soft_dirty(vma, addr, pte);
1033                         continue;
1034                 }
1035
1036                 if (!pte_present(ptent))
1037                         continue;
1038
1039                 page = vm_normal_page(vma, addr, ptent);
1040                 if (!page)
1041                         continue;
1042
1043                 /* Clear accessed and referenced bits. */
1044                 ptep_test_and_clear_young(vma, addr, pte);
1045                 test_and_clear_page_young(page);
1046                 ClearPageReferenced(page);
1047         }
1048         pte_unmap_unlock(pte - 1, ptl);
1049         cond_resched();
1050         return 0;
1051 }
1052
1053 static int clear_refs_test_walk(unsigned long start, unsigned long end,
1054                                 struct mm_walk *walk)
1055 {
1056         struct clear_refs_private *cp = walk->private;
1057         struct vm_area_struct *vma = walk->vma;
1058
1059         if (vma->vm_flags & VM_PFNMAP)
1060                 return 1;
1061
1062         /*
1063          * Writing 1 to /proc/pid/clear_refs affects all pages.
1064          * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1065          * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1066          * Writing 4 to /proc/pid/clear_refs affects all pages.
1067          */
1068         if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1069                 return 1;
1070         if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1071                 return 1;
1072         return 0;
1073 }
1074
1075 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1076                                 size_t count, loff_t *ppos)
1077 {
1078         struct task_struct *task;
1079         char buffer[PROC_NUMBUF];
1080         struct mm_struct *mm;
1081         struct vm_area_struct *vma;
1082         enum clear_refs_types type;
1083         struct mmu_gather tlb;
1084         int itype;
1085         int rv;
1086
1087         memset(buffer, 0, sizeof(buffer));
1088         if (count > sizeof(buffer) - 1)
1089                 count = sizeof(buffer) - 1;
1090         if (copy_from_user(buffer, buf, count))
1091                 return -EFAULT;
1092         rv = kstrtoint(strstrip(buffer), 10, &itype);
1093         if (rv < 0)
1094                 return rv;
1095         type = (enum clear_refs_types)itype;
1096         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1097                 return -EINVAL;
1098
1099         task = get_proc_task(file_inode(file));
1100         if (!task)
1101                 return -ESRCH;
1102         mm = get_task_mm(task);
1103         if (mm) {
1104                 struct clear_refs_private cp = {
1105                         .type = type,
1106                 };
1107                 struct mm_walk clear_refs_walk = {
1108                         .pmd_entry = clear_refs_pte_range,
1109                         .test_walk = clear_refs_test_walk,
1110                         .mm = mm,
1111                         .private = &cp,
1112                 };
1113
1114                 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1115                         if (down_write_killable(&mm->mmap_sem)) {
1116                                 count = -EINTR;
1117                                 goto out_mm;
1118                         }
1119
1120                         /*
1121                          * Writing 5 to /proc/pid/clear_refs resets the peak
1122                          * resident set size to this mm's current rss value.
1123                          */
1124                         reset_mm_hiwater_rss(mm);
1125                         up_write(&mm->mmap_sem);
1126                         goto out_mm;
1127                 }
1128
1129                 down_read(&mm->mmap_sem);
1130                 tlb_gather_mmu(&tlb, mm, 0, -1);
1131                 if (type == CLEAR_REFS_SOFT_DIRTY) {
1132                         for (vma = mm->mmap; vma; vma = vma->vm_next) {
1133                                 if (!(vma->vm_flags & VM_SOFTDIRTY))
1134                                         continue;
1135                                 up_read(&mm->mmap_sem);
1136                                 if (down_write_killable(&mm->mmap_sem)) {
1137                                         count = -EINTR;
1138                                         goto out_mm;
1139                                 }
1140                                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1141                                         vma->vm_flags &= ~VM_SOFTDIRTY;
1142                                         vma_set_page_prot(vma);
1143                                 }
1144                                 downgrade_write(&mm->mmap_sem);
1145                                 break;
1146                         }
1147                         mmu_notifier_invalidate_range_start(mm, 0, -1);
1148                 }
1149                 walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
1150                 if (type == CLEAR_REFS_SOFT_DIRTY)
1151                         mmu_notifier_invalidate_range_end(mm, 0, -1);
1152                 tlb_finish_mmu(&tlb, 0, -1);
1153                 up_read(&mm->mmap_sem);
1154 out_mm:
1155                 mmput(mm);
1156         }
1157         put_task_struct(task);
1158
1159         return count;
1160 }
1161
1162 const struct file_operations proc_clear_refs_operations = {
1163         .write          = clear_refs_write,
1164         .llseek         = noop_llseek,
1165 };
1166
1167 typedef struct {
1168         u64 pme;
1169 } pagemap_entry_t;
1170
1171 struct pagemapread {
1172         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
1173         pagemap_entry_t *buffer;
1174         bool show_pfn;
1175 };
1176
1177 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
1178 #define PAGEMAP_WALK_MASK       (PMD_MASK)
1179
1180 #define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
1181 #define PM_PFRAME_BITS          55
1182 #define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1183 #define PM_SOFT_DIRTY           BIT_ULL(55)
1184 #define PM_MMAP_EXCLUSIVE       BIT_ULL(56)
1185 #define PM_FILE                 BIT_ULL(61)
1186 #define PM_SWAP                 BIT_ULL(62)
1187 #define PM_PRESENT              BIT_ULL(63)
1188
1189 #define PM_END_OF_BUFFER    1
1190
1191 static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1192 {
1193         return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1194 }
1195
1196 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1197                           struct pagemapread *pm)
1198 {
1199         pm->buffer[pm->pos++] = *pme;
1200         if (pm->pos >= pm->len)
1201                 return PM_END_OF_BUFFER;
1202         return 0;
1203 }
1204
1205 static int pagemap_pte_hole(unsigned long start, unsigned long end,
1206                                 struct mm_walk *walk)
1207 {
1208         struct pagemapread *pm = walk->private;
1209         unsigned long addr = start;
1210         int err = 0;
1211
1212         while (addr < end) {
1213                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1214                 pagemap_entry_t pme = make_pme(0, 0);
1215                 /* End of address space hole, which we mark as non-present. */
1216                 unsigned long hole_end;
1217
1218                 if (vma)
1219                         hole_end = min(end, vma->vm_start);
1220                 else
1221                         hole_end = end;
1222
1223                 for (; addr < hole_end; addr += PAGE_SIZE) {
1224                         err = add_to_pagemap(addr, &pme, pm);
1225                         if (err)
1226                                 goto out;
1227                 }
1228
1229                 if (!vma)
1230                         break;
1231
1232                 /* Addresses in the VMA. */
1233                 if (vma->vm_flags & VM_SOFTDIRTY)
1234                         pme = make_pme(0, PM_SOFT_DIRTY);
1235                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1236                         err = add_to_pagemap(addr, &pme, pm);
1237                         if (err)
1238                                 goto out;
1239                 }
1240         }
1241 out:
1242         return err;
1243 }
1244
1245 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1246                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1247 {
1248         u64 frame = 0, flags = 0;
1249         struct page *page = NULL;
1250
1251         if (pte_present(pte)) {
1252                 if (pm->show_pfn)
1253                         frame = pte_pfn(pte);
1254                 flags |= PM_PRESENT;
1255                 page = _vm_normal_page(vma, addr, pte, true);
1256                 if (pte_soft_dirty(pte))
1257                         flags |= PM_SOFT_DIRTY;
1258         } else if (is_swap_pte(pte)) {
1259                 swp_entry_t entry;
1260                 if (pte_swp_soft_dirty(pte))
1261                         flags |= PM_SOFT_DIRTY;
1262                 entry = pte_to_swp_entry(pte);
1263                 if (pm->show_pfn)
1264                         frame = swp_type(entry) |
1265                                 (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
1266                 flags |= PM_SWAP;
1267                 if (is_migration_entry(entry))
1268                         page = migration_entry_to_page(entry);
1269
1270                 if (is_device_private_entry(entry))
1271                         page = device_private_entry_to_page(entry);
1272         }
1273
1274         if (page && !PageAnon(page))
1275                 flags |= PM_FILE;
1276         if (page && page_mapcount(page) == 1)
1277                 flags |= PM_MMAP_EXCLUSIVE;
1278         if (vma->vm_flags & VM_SOFTDIRTY)
1279                 flags |= PM_SOFT_DIRTY;
1280
1281         return make_pme(frame, flags);
1282 }
1283
1284 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1285                              struct mm_walk *walk)
1286 {
1287         struct vm_area_struct *vma = walk->vma;
1288         struct pagemapread *pm = walk->private;
1289         spinlock_t *ptl;
1290         pte_t *pte, *orig_pte;
1291         int err = 0;
1292
1293 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1294         ptl = pmd_trans_huge_lock(pmdp, vma);
1295         if (ptl) {
1296                 u64 flags = 0, frame = 0;
1297                 pmd_t pmd = *pmdp;
1298                 struct page *page = NULL;
1299
1300                 if (vma->vm_flags & VM_SOFTDIRTY)
1301                         flags |= PM_SOFT_DIRTY;
1302
1303                 if (pmd_present(pmd)) {
1304                         page = pmd_page(pmd);
1305
1306                         flags |= PM_PRESENT;
1307                         if (pmd_soft_dirty(pmd))
1308                                 flags |= PM_SOFT_DIRTY;
1309                         if (pm->show_pfn)
1310                                 frame = pmd_pfn(pmd) +
1311                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1312                 }
1313 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1314                 else if (is_swap_pmd(pmd)) {
1315                         swp_entry_t entry = pmd_to_swp_entry(pmd);
1316                         unsigned long offset;
1317
1318                         if (pm->show_pfn) {
1319                                 offset = swp_offset(entry) +
1320                                         ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1321                                 frame = swp_type(entry) |
1322                                         (offset << MAX_SWAPFILES_SHIFT);
1323                         }
1324                         flags |= PM_SWAP;
1325                         if (pmd_swp_soft_dirty(pmd))
1326                                 flags |= PM_SOFT_DIRTY;
1327                         VM_BUG_ON(!is_pmd_migration_entry(pmd));
1328                         page = migration_entry_to_page(entry);
1329                 }
1330 #endif
1331
1332                 if (page && page_mapcount(page) == 1)
1333                         flags |= PM_MMAP_EXCLUSIVE;
1334
1335                 for (; addr != end; addr += PAGE_SIZE) {
1336                         pagemap_entry_t pme = make_pme(frame, flags);
1337
1338                         err = add_to_pagemap(addr, &pme, pm);
1339                         if (err)
1340                                 break;
1341                         if (pm->show_pfn) {
1342                                 if (flags & PM_PRESENT)
1343                                         frame++;
1344                                 else if (flags & PM_SWAP)
1345                                         frame += (1 << MAX_SWAPFILES_SHIFT);
1346                         }
1347                 }
1348                 spin_unlock(ptl);
1349                 return err;
1350         }
1351
1352         if (pmd_trans_unstable(pmdp))
1353                 return 0;
1354 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1355
1356         /*
1357          * We can assume that @vma always points to a valid one and @end never
1358          * goes beyond vma->vm_end.
1359          */
1360         orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1361         for (; addr < end; pte++, addr += PAGE_SIZE) {
1362                 pagemap_entry_t pme;
1363
1364                 pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
1365                 err = add_to_pagemap(addr, &pme, pm);
1366                 if (err)
1367                         break;
1368         }
1369         pte_unmap_unlock(orig_pte, ptl);
1370
1371         cond_resched();
1372
1373         return err;
1374 }
1375
1376 #ifdef CONFIG_HUGETLB_PAGE
1377 /* This function walks within one hugetlb entry in the single call */
1378 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1379                                  unsigned long addr, unsigned long end,
1380                                  struct mm_walk *walk)
1381 {
1382         struct pagemapread *pm = walk->private;
1383         struct vm_area_struct *vma = walk->vma;
1384         u64 flags = 0, frame = 0;
1385         int err = 0;
1386         pte_t pte;
1387
1388         if (vma->vm_flags & VM_SOFTDIRTY)
1389                 flags |= PM_SOFT_DIRTY;
1390
1391         pte = huge_ptep_get(ptep);
1392         if (pte_present(pte)) {
1393                 struct page *page = pte_page(pte);
1394
1395                 if (!PageAnon(page))
1396                         flags |= PM_FILE;
1397
1398                 if (page_mapcount(page) == 1)
1399                         flags |= PM_MMAP_EXCLUSIVE;
1400
1401                 flags |= PM_PRESENT;
1402                 if (pm->show_pfn)
1403                         frame = pte_pfn(pte) +
1404                                 ((addr & ~hmask) >> PAGE_SHIFT);
1405         }
1406
1407         for (; addr != end; addr += PAGE_SIZE) {
1408                 pagemap_entry_t pme = make_pme(frame, flags);
1409
1410                 err = add_to_pagemap(addr, &pme, pm);
1411                 if (err)
1412                         return err;
1413                 if (pm->show_pfn && (flags & PM_PRESENT))
1414                         frame++;
1415         }
1416
1417         cond_resched();
1418
1419         return err;
1420 }
1421 #endif /* HUGETLB_PAGE */
1422
1423 /*
1424  * /proc/pid/pagemap - an array mapping virtual pages to pfns
1425  *
1426  * For each page in the address space, this file contains one 64-bit entry
1427  * consisting of the following:
1428  *
1429  * Bits 0-54  page frame number (PFN) if present
1430  * Bits 0-4   swap type if swapped
1431  * Bits 5-54  swap offset if swapped
1432  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1433  * Bit  56    page exclusively mapped
1434  * Bits 57-60 zero
1435  * Bit  61    page is file-page or shared-anon
1436  * Bit  62    page swapped
1437  * Bit  63    page present
1438  *
1439  * If the page is not present but in swap, then the PFN contains an
1440  * encoding of the swap file number and the page's offset into the
1441  * swap. Unmapped pages return a null PFN. This allows determining
1442  * precisely which pages are mapped (or in swap) and comparing mapped
1443  * pages between processes.
1444  *
1445  * Efficient users of this interface will use /proc/pid/maps to
1446  * determine which areas of memory are actually mapped and llseek to
1447  * skip over unmapped regions.
1448  */
1449 static ssize_t pagemap_read(struct file *file, char __user *buf,
1450                             size_t count, loff_t *ppos)
1451 {
1452         struct mm_struct *mm = file->private_data;
1453         struct pagemapread pm;
1454         struct mm_walk pagemap_walk = {};
1455         unsigned long src;
1456         unsigned long svpfn;
1457         unsigned long start_vaddr;
1458         unsigned long end_vaddr;
1459         int ret = 0, copied = 0;
1460
1461         if (!mm || !mmget_not_zero(mm))
1462                 goto out;
1463
1464         ret = -EINVAL;
1465         /* file position must be aligned */
1466         if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1467                 goto out_mm;
1468
1469         ret = 0;
1470         if (!count)
1471                 goto out_mm;
1472
1473         /* do not disclose physical addresses: attack vector */
1474         pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1475
1476         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1477         pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1478         ret = -ENOMEM;
1479         if (!pm.buffer)
1480                 goto out_mm;
1481
1482         pagemap_walk.pmd_entry = pagemap_pmd_range;
1483         pagemap_walk.pte_hole = pagemap_pte_hole;
1484 #ifdef CONFIG_HUGETLB_PAGE
1485         pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
1486 #endif
1487         pagemap_walk.mm = mm;
1488         pagemap_walk.private = &pm;
1489
1490         src = *ppos;
1491         svpfn = src / PM_ENTRY_BYTES;
1492         start_vaddr = svpfn << PAGE_SHIFT;
1493         end_vaddr = mm->task_size;
1494
1495         /* watch out for wraparound */
1496         if (svpfn > mm->task_size >> PAGE_SHIFT)
1497                 start_vaddr = end_vaddr;
1498
1499         /*
1500          * The odds are that this will stop walking way
1501          * before end_vaddr, because the length of the
1502          * user buffer is tracked in "pm", and the walk
1503          * will stop when we hit the end of the buffer.
1504          */
1505         ret = 0;
1506         while (count && (start_vaddr < end_vaddr)) {
1507                 int len;
1508                 unsigned long end;
1509
1510                 pm.pos = 0;
1511                 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1512                 /* overflow ? */
1513                 if (end < start_vaddr || end > end_vaddr)
1514                         end = end_vaddr;
1515                 down_read(&mm->mmap_sem);
1516                 ret = walk_page_range(start_vaddr, end, &pagemap_walk);
1517                 up_read(&mm->mmap_sem);
1518                 start_vaddr = end;
1519
1520                 len = min(count, PM_ENTRY_BYTES * pm.pos);
1521                 if (copy_to_user(buf, pm.buffer, len)) {
1522                         ret = -EFAULT;
1523                         goto out_free;
1524                 }
1525                 copied += len;
1526                 buf += len;
1527                 count -= len;
1528         }
1529         *ppos += copied;
1530         if (!ret || ret == PM_END_OF_BUFFER)
1531                 ret = copied;
1532
1533 out_free:
1534         kfree(pm.buffer);
1535 out_mm:
1536         mmput(mm);
1537 out:
1538         return ret;
1539 }
1540
1541 static int pagemap_open(struct inode *inode, struct file *file)
1542 {
1543         struct mm_struct *mm;
1544
1545         mm = proc_mem_open(inode, PTRACE_MODE_READ);
1546         if (IS_ERR(mm))
1547                 return PTR_ERR(mm);
1548         file->private_data = mm;
1549         return 0;
1550 }
1551
1552 static int pagemap_release(struct inode *inode, struct file *file)
1553 {
1554         struct mm_struct *mm = file->private_data;
1555
1556         if (mm)
1557                 mmdrop(mm);
1558         return 0;
1559 }
1560
1561 const struct file_operations proc_pagemap_operations = {
1562         .llseek         = mem_lseek, /* borrow this */
1563         .read           = pagemap_read,
1564         .open           = pagemap_open,
1565         .release        = pagemap_release,
1566 };
1567 #endif /* CONFIG_PROC_PAGE_MONITOR */
1568
1569 #ifdef CONFIG_NUMA
1570
1571 struct numa_maps {
1572         unsigned long pages;
1573         unsigned long anon;
1574         unsigned long active;
1575         unsigned long writeback;
1576         unsigned long mapcount_max;
1577         unsigned long dirty;
1578         unsigned long swapcache;
1579         unsigned long node[MAX_NUMNODES];
1580 };
1581
1582 struct numa_maps_private {
1583         struct proc_maps_private proc_maps;
1584         struct numa_maps md;
1585 };
1586
1587 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
1588                         unsigned long nr_pages)
1589 {
1590         int count = page_mapcount(page);
1591
1592         md->pages += nr_pages;
1593         if (pte_dirty || PageDirty(page))
1594                 md->dirty += nr_pages;
1595
1596         if (PageSwapCache(page))
1597                 md->swapcache += nr_pages;
1598
1599         if (PageActive(page) || PageUnevictable(page))
1600                 md->active += nr_pages;
1601
1602         if (PageWriteback(page))
1603                 md->writeback += nr_pages;
1604
1605         if (PageAnon(page))
1606                 md->anon += nr_pages;
1607
1608         if (count > md->mapcount_max)
1609                 md->mapcount_max = count;
1610
1611         md->node[page_to_nid(page)] += nr_pages;
1612 }
1613
1614 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
1615                 unsigned long addr)
1616 {
1617         struct page *page;
1618         int nid;
1619
1620         if (!pte_present(pte))
1621                 return NULL;
1622
1623         page = vm_normal_page(vma, addr, pte);
1624         if (!page)
1625                 return NULL;
1626
1627         if (PageReserved(page))
1628                 return NULL;
1629
1630         nid = page_to_nid(page);
1631         if (!node_isset(nid, node_states[N_MEMORY]))
1632                 return NULL;
1633
1634         return page;
1635 }
1636
1637 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1638 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
1639                                               struct vm_area_struct *vma,
1640                                               unsigned long addr)
1641 {
1642         struct page *page;
1643         int nid;
1644
1645         if (!pmd_present(pmd))
1646                 return NULL;
1647
1648         page = vm_normal_page_pmd(vma, addr, pmd);
1649         if (!page)
1650                 return NULL;
1651
1652         if (PageReserved(page))
1653                 return NULL;
1654
1655         nid = page_to_nid(page);
1656         if (!node_isset(nid, node_states[N_MEMORY]))
1657                 return NULL;
1658
1659         return page;
1660 }
1661 #endif
1662
1663 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
1664                 unsigned long end, struct mm_walk *walk)
1665 {
1666         struct numa_maps *md = walk->private;
1667         struct vm_area_struct *vma = walk->vma;
1668         spinlock_t *ptl;
1669         pte_t *orig_pte;
1670         pte_t *pte;
1671
1672 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1673         ptl = pmd_trans_huge_lock(pmd, vma);
1674         if (ptl) {
1675                 struct page *page;
1676
1677                 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
1678                 if (page)
1679                         gather_stats(page, md, pmd_dirty(*pmd),
1680                                      HPAGE_PMD_SIZE/PAGE_SIZE);
1681                 spin_unlock(ptl);
1682                 return 0;
1683         }
1684
1685         if (pmd_trans_unstable(pmd))
1686                 return 0;
1687 #endif
1688         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
1689         do {
1690                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
1691                 if (!page)
1692                         continue;
1693                 gather_stats(page, md, pte_dirty(*pte), 1);
1694
1695         } while (pte++, addr += PAGE_SIZE, addr != end);
1696         pte_unmap_unlock(orig_pte, ptl);
1697         cond_resched();
1698         return 0;
1699 }
1700 #ifdef CONFIG_HUGETLB_PAGE
1701 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1702                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1703 {
1704         pte_t huge_pte = huge_ptep_get(pte);
1705         struct numa_maps *md;
1706         struct page *page;
1707
1708         if (!pte_present(huge_pte))
1709                 return 0;
1710
1711         page = pte_page(huge_pte);
1712         if (!page)
1713                 return 0;
1714
1715         md = walk->private;
1716         gather_stats(page, md, pte_dirty(huge_pte), 1);
1717         return 0;
1718 }
1719
1720 #else
1721 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
1722                 unsigned long addr, unsigned long end, struct mm_walk *walk)
1723 {
1724         return 0;
1725 }
1726 #endif
1727
1728 /*
1729  * Display pages allocated per node and memory policy via /proc.
1730  */
1731 static int show_numa_map(struct seq_file *m, void *v, int is_pid)
1732 {
1733         struct numa_maps_private *numa_priv = m->private;
1734         struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1735         struct vm_area_struct *vma = v;
1736         struct numa_maps *md = &numa_priv->md;
1737         struct file *file = vma->vm_file;
1738         struct mm_struct *mm = vma->vm_mm;
1739         struct mm_walk walk = {
1740                 .hugetlb_entry = gather_hugetlb_stats,
1741                 .pmd_entry = gather_pte_stats,
1742                 .private = md,
1743                 .mm = mm,
1744         };
1745         struct mempolicy *pol;
1746         char buffer[64];
1747         int nid;
1748
1749         if (!mm)
1750                 return 0;
1751
1752         /* Ensure we start with an empty set of numa_maps statistics. */
1753         memset(md, 0, sizeof(*md));
1754
1755         pol = __get_vma_policy(vma, vma->vm_start);
1756         if (pol) {
1757                 mpol_to_str(buffer, sizeof(buffer), pol);
1758                 mpol_cond_put(pol);
1759         } else {
1760                 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
1761         }
1762
1763         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1764
1765         if (file) {
1766                 seq_puts(m, " file=");
1767                 seq_file_path(m, file, "\n\t= ");
1768         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1769                 seq_puts(m, " heap");
1770         } else if (is_stack(vma)) {
1771                 seq_puts(m, " stack");
1772         }
1773
1774         if (is_vm_hugetlb_page(vma))
1775                 seq_puts(m, " huge");
1776
1777         /* mmap_sem is held by m_start */
1778         walk_page_vma(vma, &walk);
1779
1780         if (!md->pages)
1781                 goto out;
1782
1783         if (md->anon)
1784                 seq_printf(m, " anon=%lu", md->anon);
1785
1786         if (md->dirty)
1787                 seq_printf(m, " dirty=%lu", md->dirty);
1788
1789         if (md->pages != md->anon && md->pages != md->dirty)
1790                 seq_printf(m, " mapped=%lu", md->pages);
1791
1792         if (md->mapcount_max > 1)
1793                 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1794
1795         if (md->swapcache)
1796                 seq_printf(m, " swapcache=%lu", md->swapcache);
1797
1798         if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1799                 seq_printf(m, " active=%lu", md->active);
1800
1801         if (md->writeback)
1802                 seq_printf(m, " writeback=%lu", md->writeback);
1803
1804         for_each_node_state(nid, N_MEMORY)
1805                 if (md->node[nid])
1806                         seq_printf(m, " N%d=%lu", nid, md->node[nid]);
1807
1808         seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
1809 out:
1810         seq_putc(m, '\n');
1811         m_cache_vma(m, vma);
1812         return 0;
1813 }
1814
1815 static int show_pid_numa_map(struct seq_file *m, void *v)
1816 {
1817         return show_numa_map(m, v, 1);
1818 }
1819
1820 static int show_tid_numa_map(struct seq_file *m, void *v)
1821 {
1822         return show_numa_map(m, v, 0);
1823 }
1824
1825 static const struct seq_operations proc_pid_numa_maps_op = {
1826         .start  = m_start,
1827         .next   = m_next,
1828         .stop   = m_stop,
1829         .show   = show_pid_numa_map,
1830 };
1831
1832 static const struct seq_operations proc_tid_numa_maps_op = {
1833         .start  = m_start,
1834         .next   = m_next,
1835         .stop   = m_stop,
1836         .show   = show_tid_numa_map,
1837 };
1838
1839 static int numa_maps_open(struct inode *inode, struct file *file,
1840                           const struct seq_operations *ops)
1841 {
1842         return proc_maps_open(inode, file, ops,
1843                                 sizeof(struct numa_maps_private));
1844 }
1845
1846 static int pid_numa_maps_open(struct inode *inode, struct file *file)
1847 {
1848         return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
1849 }
1850
1851 static int tid_numa_maps_open(struct inode *inode, struct file *file)
1852 {
1853         return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
1854 }
1855
1856 const struct file_operations proc_pid_numa_maps_operations = {
1857         .open           = pid_numa_maps_open,
1858         .read           = seq_read,
1859         .llseek         = seq_lseek,
1860         .release        = proc_map_release,
1861 };
1862
1863 const struct file_operations proc_tid_numa_maps_operations = {
1864         .open           = tid_numa_maps_open,
1865         .read           = seq_read,
1866         .llseek         = seq_lseek,
1867         .release        = proc_map_release,
1868 };
1869 #endif /* CONFIG_NUMA */