1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/pagewalk.h> 3 #include <linux/mm_inline.h> 4 #include <linux/hugetlb.h> 5 #include <linux/huge_mm.h> 6 #include <linux/mount.h> 7 #include <linux/ksm.h> 8 #include <linux/seq_file.h> 9 #include <linux/highmem.h> 10 #include <linux/ptrace.h> 11 #include <linux/slab.h> 12 #include <linux/pagemap.h> 13 #include <linux/mempolicy.h> 14 #include <linux/rmap.h> 15 #include <linux/swap.h> 16 #include <linux/sched/mm.h> 17 #include <linux/swapops.h> 18 #include <linux/mmu_notifier.h> 19 #include <linux/page_idle.h> 20 #include <linux/shmem_fs.h> 21 #include <linux/uaccess.h> 22 #include <linux/pkeys.h> 23 #include <linux/minmax.h> 24 #include <linux/overflow.h> 25 26 #include <asm/elf.h> 27 #include <asm/tlb.h> 28 #include <asm/tlbflush.h> 29 #include "internal.h" 30 31 #define SEQ_PUT_DEC(str, val) \ 32 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8) 33 void task_mem(struct seq_file *m, struct mm_struct *mm) 34 { 35 unsigned long text, lib, swap, anon, file, shmem; 36 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; 37 38 anon = get_mm_counter(mm, MM_ANONPAGES); 39 file = get_mm_counter(mm, MM_FILEPAGES); 40 shmem = get_mm_counter(mm, MM_SHMEMPAGES); 41 42 /* 43 * Note: to minimize their overhead, mm maintains hiwater_vm and 44 * hiwater_rss only when about to *lower* total_vm or rss. Any 45 * collector of these hiwater stats must therefore get total_vm 46 * and rss too, which will usually be the higher. Barriers? not 47 * worth the effort, such snapshots can always be inconsistent. 48 */ 49 hiwater_vm = total_vm = mm->total_vm; 50 if (hiwater_vm < mm->hiwater_vm) 51 hiwater_vm = mm->hiwater_vm; 52 hiwater_rss = total_rss = anon + file + shmem; 53 if (hiwater_rss < mm->hiwater_rss) 54 hiwater_rss = mm->hiwater_rss; 55 56 /* split executable areas between text and lib */ 57 text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK); 58 text = min(text, mm->exec_vm << PAGE_SHIFT); 59 lib = (mm->exec_vm << PAGE_SHIFT) - text; 60 61 swap = get_mm_counter(mm, MM_SWAPENTS); 62 SEQ_PUT_DEC("VmPeak:\t", hiwater_vm); 63 SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm); 64 SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm); 65 SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm)); 66 SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss); 67 SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss); 68 SEQ_PUT_DEC(" kB\nRssAnon:\t", anon); 69 SEQ_PUT_DEC(" kB\nRssFile:\t", file); 70 SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem); 71 SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm); 72 SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm); 73 seq_put_decimal_ull_width(m, 74 " kB\nVmExe:\t", text >> 10, 8); 75 seq_put_decimal_ull_width(m, 76 " kB\nVmLib:\t", lib >> 10, 8); 77 seq_put_decimal_ull_width(m, 78 " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); 79 SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); 80 seq_puts(m, " kB\n"); 81 hugetlb_report_usage(m, mm); 82 } 83 #undef SEQ_PUT_DEC 84 85 unsigned long task_vsize(struct mm_struct *mm) 86 { 87 return PAGE_SIZE * mm->total_vm; 88 } 89 90 unsigned long task_statm(struct mm_struct *mm, 91 unsigned long *shared, unsigned long *text, 92 unsigned long *data, unsigned long *resident) 93 { 94 *shared = get_mm_counter(mm, MM_FILEPAGES) + 95 get_mm_counter(mm, MM_SHMEMPAGES); 96 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 97 >> PAGE_SHIFT; 98 *data = mm->data_vm + mm->stack_vm; 99 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); 100 return mm->total_vm; 101 } 102 103 #ifdef CONFIG_NUMA 104 /* 105 * Save get_task_policy() for show_numa_map(). 106 */ 107 static void hold_task_mempolicy(struct proc_maps_private *priv) 108 { 109 struct task_struct *task = priv->task; 110 111 task_lock(task); 112 priv->task_mempolicy = get_task_policy(task); 113 mpol_get(priv->task_mempolicy); 114 task_unlock(task); 115 } 116 static void release_task_mempolicy(struct proc_maps_private *priv) 117 { 118 mpol_put(priv->task_mempolicy); 119 } 120 #else 121 static void hold_task_mempolicy(struct proc_maps_private *priv) 122 { 123 } 124 static void release_task_mempolicy(struct proc_maps_private *priv) 125 { 126 } 127 #endif 128 129 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, 130 loff_t *ppos) 131 { 132 struct vm_area_struct *vma = vma_next(&priv->iter); 133 134 if (vma) { 135 *ppos = vma->vm_start; 136 } else { 137 *ppos = -2UL; 138 vma = get_gate_vma(priv->mm); 139 } 140 141 return vma; 142 } 143 144 static void *m_start(struct seq_file *m, loff_t *ppos) 145 { 146 struct proc_maps_private *priv = m->private; 147 unsigned long last_addr = *ppos; 148 struct mm_struct *mm; 149 150 /* See m_next(). Zero at the start or after lseek. */ 151 if (last_addr == -1UL) 152 return NULL; 153 154 priv->task = get_proc_task(priv->inode); 155 if (!priv->task) 156 return ERR_PTR(-ESRCH); 157 158 mm = priv->mm; 159 if (!mm || !mmget_not_zero(mm)) { 160 put_task_struct(priv->task); 161 priv->task = NULL; 162 return NULL; 163 } 164 165 if (mmap_read_lock_killable(mm)) { 166 mmput(mm); 167 put_task_struct(priv->task); 168 priv->task = NULL; 169 return ERR_PTR(-EINTR); 170 } 171 172 vma_iter_init(&priv->iter, mm, last_addr); 173 hold_task_mempolicy(priv); 174 if (last_addr == -2UL) 175 return get_gate_vma(mm); 176 177 return proc_get_vma(priv, ppos); 178 } 179 180 static void *m_next(struct seq_file *m, void *v, loff_t *ppos) 181 { 182 if (*ppos == -2UL) { 183 *ppos = -1UL; 184 return NULL; 185 } 186 return proc_get_vma(m->private, ppos); 187 } 188 189 static void m_stop(struct seq_file *m, void *v) 190 { 191 struct proc_maps_private *priv = m->private; 192 struct mm_struct *mm = priv->mm; 193 194 if (!priv->task) 195 return; 196 197 release_task_mempolicy(priv); 198 mmap_read_unlock(mm); 199 mmput(mm); 200 put_task_struct(priv->task); 201 priv->task = NULL; 202 } 203 204 static int proc_maps_open(struct inode *inode, struct file *file, 205 const struct seq_operations *ops, int psize) 206 { 207 struct proc_maps_private *priv = __seq_open_private(file, ops, psize); 208 209 if (!priv) 210 return -ENOMEM; 211 212 priv->inode = inode; 213 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 214 if (IS_ERR(priv->mm)) { 215 int err = PTR_ERR(priv->mm); 216 217 seq_release_private(inode, file); 218 return err; 219 } 220 221 return 0; 222 } 223 224 static int proc_map_release(struct inode *inode, struct file *file) 225 { 226 struct seq_file *seq = file->private_data; 227 struct proc_maps_private *priv = seq->private; 228 229 if (priv->mm) 230 mmdrop(priv->mm); 231 232 return seq_release_private(inode, file); 233 } 234 235 static int do_maps_open(struct inode *inode, struct file *file, 236 const struct seq_operations *ops) 237 { 238 return proc_maps_open(inode, file, ops, 239 sizeof(struct proc_maps_private)); 240 } 241 242 static void show_vma_header_prefix(struct seq_file *m, 243 unsigned long start, unsigned long end, 244 vm_flags_t flags, unsigned long long pgoff, 245 dev_t dev, unsigned long ino) 246 { 247 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 248 seq_put_hex_ll(m, NULL, start, 8); 249 seq_put_hex_ll(m, "-", end, 8); 250 seq_putc(m, ' '); 251 seq_putc(m, flags & VM_READ ? 'r' : '-'); 252 seq_putc(m, flags & VM_WRITE ? 'w' : '-'); 253 seq_putc(m, flags & VM_EXEC ? 'x' : '-'); 254 seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p'); 255 seq_put_hex_ll(m, " ", pgoff, 8); 256 seq_put_hex_ll(m, " ", MAJOR(dev), 2); 257 seq_put_hex_ll(m, ":", MINOR(dev), 2); 258 seq_put_decimal_ull(m, " ", ino); 259 seq_putc(m, ' '); 260 } 261 262 static void 263 show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 264 { 265 struct anon_vma_name *anon_name = NULL; 266 struct mm_struct *mm = vma->vm_mm; 267 struct file *file = vma->vm_file; 268 vm_flags_t flags = vma->vm_flags; 269 unsigned long ino = 0; 270 unsigned long long pgoff = 0; 271 unsigned long start, end; 272 dev_t dev = 0; 273 const char *name = NULL; 274 275 if (file) { 276 const struct inode *inode = file_user_inode(vma->vm_file); 277 278 dev = inode->i_sb->s_dev; 279 ino = inode->i_ino; 280 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 281 } 282 283 start = vma->vm_start; 284 end = vma->vm_end; 285 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino); 286 if (mm) 287 anon_name = anon_vma_name(vma); 288 289 /* 290 * Print the dentry name for named mappings, and a 291 * special [heap] marker for the heap: 292 */ 293 if (file) { 294 seq_pad(m, ' '); 295 /* 296 * If user named this anon shared memory via 297 * prctl(PR_SET_VMA ..., use the provided name. 298 */ 299 if (anon_name) 300 seq_printf(m, "[anon_shmem:%s]", anon_name->name); 301 else 302 seq_path(m, file_user_path(file), "\n"); 303 goto done; 304 } 305 306 if (vma->vm_ops && vma->vm_ops->name) { 307 name = vma->vm_ops->name(vma); 308 if (name) 309 goto done; 310 } 311 312 name = arch_vma_name(vma); 313 if (!name) { 314 if (!mm) { 315 name = "[vdso]"; 316 goto done; 317 } 318 319 if (vma_is_initial_heap(vma)) { 320 name = "[heap]"; 321 goto done; 322 } 323 324 if (vma_is_initial_stack(vma)) { 325 name = "[stack]"; 326 goto done; 327 } 328 329 if (anon_name) { 330 seq_pad(m, ' '); 331 seq_printf(m, "[anon:%s]", anon_name->name); 332 } 333 } 334 335 done: 336 if (name) { 337 seq_pad(m, ' '); 338 seq_puts(m, name); 339 } 340 seq_putc(m, '\n'); 341 } 342 343 static int show_map(struct seq_file *m, void *v) 344 { 345 show_map_vma(m, v); 346 return 0; 347 } 348 349 static const struct seq_operations proc_pid_maps_op = { 350 .start = m_start, 351 .next = m_next, 352 .stop = m_stop, 353 .show = show_map 354 }; 355 356 static int pid_maps_open(struct inode *inode, struct file *file) 357 { 358 return do_maps_open(inode, file, &proc_pid_maps_op); 359 } 360 361 const struct file_operations proc_pid_maps_operations = { 362 .open = pid_maps_open, 363 .read = seq_read, 364 .llseek = seq_lseek, 365 .release = proc_map_release, 366 }; 367 368 /* 369 * Proportional Set Size(PSS): my share of RSS. 370 * 371 * PSS of a process is the count of pages it has in memory, where each 372 * page is divided by the number of processes sharing it. So if a 373 * process has 1000 pages all to itself, and 1000 shared with one other 374 * process, its PSS will be 1500. 375 * 376 * To keep (accumulated) division errors low, we adopt a 64bit 377 * fixed-point pss counter to minimize division errors. So (pss >> 378 * PSS_SHIFT) would be the real byte count. 379 * 380 * A shift of 12 before division means (assuming 4K page size): 381 * - 1M 3-user-pages add up to 8KB errors; 382 * - supports mapcount up to 2^24, or 16M; 383 * - supports PSS up to 2^52 bytes, or 4PB. 384 */ 385 #define PSS_SHIFT 12 386 387 #ifdef CONFIG_PROC_PAGE_MONITOR 388 struct mem_size_stats { 389 unsigned long resident; 390 unsigned long shared_clean; 391 unsigned long shared_dirty; 392 unsigned long private_clean; 393 unsigned long private_dirty; 394 unsigned long referenced; 395 unsigned long anonymous; 396 unsigned long lazyfree; 397 unsigned long anonymous_thp; 398 unsigned long shmem_thp; 399 unsigned long file_thp; 400 unsigned long swap; 401 unsigned long shared_hugetlb; 402 unsigned long private_hugetlb; 403 unsigned long ksm; 404 u64 pss; 405 u64 pss_anon; 406 u64 pss_file; 407 u64 pss_shmem; 408 u64 pss_dirty; 409 u64 pss_locked; 410 u64 swap_pss; 411 }; 412 413 static void smaps_page_accumulate(struct mem_size_stats *mss, 414 struct page *page, unsigned long size, unsigned long pss, 415 bool dirty, bool locked, bool private) 416 { 417 mss->pss += pss; 418 419 if (PageAnon(page)) 420 mss->pss_anon += pss; 421 else if (PageSwapBacked(page)) 422 mss->pss_shmem += pss; 423 else 424 mss->pss_file += pss; 425 426 if (locked) 427 mss->pss_locked += pss; 428 429 if (dirty || PageDirty(page)) { 430 mss->pss_dirty += pss; 431 if (private) 432 mss->private_dirty += size; 433 else 434 mss->shared_dirty += size; 435 } else { 436 if (private) 437 mss->private_clean += size; 438 else 439 mss->shared_clean += size; 440 } 441 } 442 443 static void smaps_account(struct mem_size_stats *mss, struct page *page, 444 bool compound, bool young, bool dirty, bool locked, 445 bool migration) 446 { 447 int i, nr = compound ? compound_nr(page) : 1; 448 unsigned long size = nr * PAGE_SIZE; 449 450 /* 451 * First accumulate quantities that depend only on |size| and the type 452 * of the compound page. 453 */ 454 if (PageAnon(page)) { 455 mss->anonymous += size; 456 if (!PageSwapBacked(page) && !dirty && !PageDirty(page)) 457 mss->lazyfree += size; 458 } 459 460 if (PageKsm(page)) 461 mss->ksm += size; 462 463 mss->resident += size; 464 /* Accumulate the size in pages that have been accessed. */ 465 if (young || page_is_young(page) || PageReferenced(page)) 466 mss->referenced += size; 467 468 /* 469 * Then accumulate quantities that may depend on sharing, or that may 470 * differ page-by-page. 471 * 472 * page_count(page) == 1 guarantees the page is mapped exactly once. 473 * If any subpage of the compound page mapped with PTE it would elevate 474 * page_count(). 475 * 476 * The page_mapcount() is called to get a snapshot of the mapcount. 477 * Without holding the page lock this snapshot can be slightly wrong as 478 * we cannot always read the mapcount atomically. It is not safe to 479 * call page_mapcount() even with PTL held if the page is not mapped, 480 * especially for migration entries. Treat regular migration entries 481 * as mapcount == 1. 482 */ 483 if ((page_count(page) == 1) || migration) { 484 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty, 485 locked, true); 486 return; 487 } 488 for (i = 0; i < nr; i++, page++) { 489 int mapcount = page_mapcount(page); 490 unsigned long pss = PAGE_SIZE << PSS_SHIFT; 491 if (mapcount >= 2) 492 pss /= mapcount; 493 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked, 494 mapcount < 2); 495 } 496 } 497 498 #ifdef CONFIG_SHMEM 499 static int smaps_pte_hole(unsigned long addr, unsigned long end, 500 __always_unused int depth, struct mm_walk *walk) 501 { 502 struct mem_size_stats *mss = walk->private; 503 struct vm_area_struct *vma = walk->vma; 504 505 mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping, 506 linear_page_index(vma, addr), 507 linear_page_index(vma, end)); 508 509 return 0; 510 } 511 #else 512 #define smaps_pte_hole NULL 513 #endif /* CONFIG_SHMEM */ 514 515 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk) 516 { 517 #ifdef CONFIG_SHMEM 518 if (walk->ops->pte_hole) { 519 /* depth is not used */ 520 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk); 521 } 522 #endif 523 } 524 525 static void smaps_pte_entry(pte_t *pte, unsigned long addr, 526 struct mm_walk *walk) 527 { 528 struct mem_size_stats *mss = walk->private; 529 struct vm_area_struct *vma = walk->vma; 530 bool locked = !!(vma->vm_flags & VM_LOCKED); 531 struct page *page = NULL; 532 bool migration = false, young = false, dirty = false; 533 pte_t ptent = ptep_get(pte); 534 535 if (pte_present(ptent)) { 536 page = vm_normal_page(vma, addr, ptent); 537 young = pte_young(ptent); 538 dirty = pte_dirty(ptent); 539 } else if (is_swap_pte(ptent)) { 540 swp_entry_t swpent = pte_to_swp_entry(ptent); 541 542 if (!non_swap_entry(swpent)) { 543 int mapcount; 544 545 mss->swap += PAGE_SIZE; 546 mapcount = swp_swapcount(swpent); 547 if (mapcount >= 2) { 548 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; 549 550 do_div(pss_delta, mapcount); 551 mss->swap_pss += pss_delta; 552 } else { 553 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; 554 } 555 } else if (is_pfn_swap_entry(swpent)) { 556 if (is_migration_entry(swpent)) 557 migration = true; 558 page = pfn_swap_entry_to_page(swpent); 559 } 560 } else { 561 smaps_pte_hole_lookup(addr, walk); 562 return; 563 } 564 565 if (!page) 566 return; 567 568 smaps_account(mss, page, false, young, dirty, locked, migration); 569 } 570 571 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 572 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 573 struct mm_walk *walk) 574 { 575 struct mem_size_stats *mss = walk->private; 576 struct vm_area_struct *vma = walk->vma; 577 bool locked = !!(vma->vm_flags & VM_LOCKED); 578 struct page *page = NULL; 579 bool migration = false; 580 581 if (pmd_present(*pmd)) { 582 page = vm_normal_page_pmd(vma, addr, *pmd); 583 } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) { 584 swp_entry_t entry = pmd_to_swp_entry(*pmd); 585 586 if (is_migration_entry(entry)) { 587 migration = true; 588 page = pfn_swap_entry_to_page(entry); 589 } 590 } 591 if (IS_ERR_OR_NULL(page)) 592 return; 593 if (PageAnon(page)) 594 mss->anonymous_thp += HPAGE_PMD_SIZE; 595 else if (PageSwapBacked(page)) 596 mss->shmem_thp += HPAGE_PMD_SIZE; 597 else if (is_zone_device_page(page)) 598 /* pass */; 599 else 600 mss->file_thp += HPAGE_PMD_SIZE; 601 602 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), 603 locked, migration); 604 } 605 #else 606 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 607 struct mm_walk *walk) 608 { 609 } 610 #endif 611 612 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 613 struct mm_walk *walk) 614 { 615 struct vm_area_struct *vma = walk->vma; 616 pte_t *pte; 617 spinlock_t *ptl; 618 619 ptl = pmd_trans_huge_lock(pmd, vma); 620 if (ptl) { 621 smaps_pmd_entry(pmd, addr, walk); 622 spin_unlock(ptl); 623 goto out; 624 } 625 626 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 627 if (!pte) { 628 walk->action = ACTION_AGAIN; 629 return 0; 630 } 631 for (; addr != end; pte++, addr += PAGE_SIZE) 632 smaps_pte_entry(pte, addr, walk); 633 pte_unmap_unlock(pte - 1, ptl); 634 out: 635 cond_resched(); 636 return 0; 637 } 638 639 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) 640 { 641 /* 642 * Don't forget to update Documentation/ on changes. 643 */ 644 static const char mnemonics[BITS_PER_LONG][2] = { 645 /* 646 * In case if we meet a flag we don't know about. 647 */ 648 [0 ... (BITS_PER_LONG-1)] = "??", 649 650 [ilog2(VM_READ)] = "rd", 651 [ilog2(VM_WRITE)] = "wr", 652 [ilog2(VM_EXEC)] = "ex", 653 [ilog2(VM_SHARED)] = "sh", 654 [ilog2(VM_MAYREAD)] = "mr", 655 [ilog2(VM_MAYWRITE)] = "mw", 656 [ilog2(VM_MAYEXEC)] = "me", 657 [ilog2(VM_MAYSHARE)] = "ms", 658 [ilog2(VM_GROWSDOWN)] = "gd", 659 [ilog2(VM_PFNMAP)] = "pf", 660 [ilog2(VM_LOCKED)] = "lo", 661 [ilog2(VM_IO)] = "io", 662 [ilog2(VM_SEQ_READ)] = "sr", 663 [ilog2(VM_RAND_READ)] = "rr", 664 [ilog2(VM_DONTCOPY)] = "dc", 665 [ilog2(VM_DONTEXPAND)] = "de", 666 [ilog2(VM_LOCKONFAULT)] = "lf", 667 [ilog2(VM_ACCOUNT)] = "ac", 668 [ilog2(VM_NORESERVE)] = "nr", 669 [ilog2(VM_HUGETLB)] = "ht", 670 [ilog2(VM_SYNC)] = "sf", 671 [ilog2(VM_ARCH_1)] = "ar", 672 [ilog2(VM_WIPEONFORK)] = "wf", 673 [ilog2(VM_DONTDUMP)] = "dd", 674 #ifdef CONFIG_ARM64_BTI 675 [ilog2(VM_ARM64_BTI)] = "bt", 676 #endif 677 #ifdef CONFIG_MEM_SOFT_DIRTY 678 [ilog2(VM_SOFTDIRTY)] = "sd", 679 #endif 680 [ilog2(VM_MIXEDMAP)] = "mm", 681 [ilog2(VM_HUGEPAGE)] = "hg", 682 [ilog2(VM_NOHUGEPAGE)] = "nh", 683 [ilog2(VM_MERGEABLE)] = "mg", 684 [ilog2(VM_UFFD_MISSING)]= "um", 685 [ilog2(VM_UFFD_WP)] = "uw", 686 #ifdef CONFIG_ARM64_MTE 687 [ilog2(VM_MTE)] = "mt", 688 [ilog2(VM_MTE_ALLOWED)] = "", 689 #endif 690 #ifdef CONFIG_ARCH_HAS_PKEYS 691 /* These come out via ProtectionKey: */ 692 [ilog2(VM_PKEY_BIT0)] = "", 693 [ilog2(VM_PKEY_BIT1)] = "", 694 [ilog2(VM_PKEY_BIT2)] = "", 695 [ilog2(VM_PKEY_BIT3)] = "", 696 #if VM_PKEY_BIT4 697 [ilog2(VM_PKEY_BIT4)] = "", 698 #endif 699 #endif /* CONFIG_ARCH_HAS_PKEYS */ 700 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR 701 [ilog2(VM_UFFD_MINOR)] = "ui", 702 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ 703 #ifdef CONFIG_X86_USER_SHADOW_STACK 704 [ilog2(VM_SHADOW_STACK)] = "ss", 705 #endif 706 }; 707 size_t i; 708 709 seq_puts(m, "VmFlags: "); 710 for (i = 0; i < BITS_PER_LONG; i++) { 711 if (!mnemonics[i][0]) 712 continue; 713 if (vma->vm_flags & (1UL << i)) { 714 seq_putc(m, mnemonics[i][0]); 715 seq_putc(m, mnemonics[i][1]); 716 seq_putc(m, ' '); 717 } 718 } 719 seq_putc(m, '\n'); 720 } 721 722 #ifdef CONFIG_HUGETLB_PAGE 723 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, 724 unsigned long addr, unsigned long end, 725 struct mm_walk *walk) 726 { 727 struct mem_size_stats *mss = walk->private; 728 struct vm_area_struct *vma = walk->vma; 729 struct page *page = NULL; 730 pte_t ptent = ptep_get(pte); 731 732 if (pte_present(ptent)) { 733 page = vm_normal_page(vma, addr, ptent); 734 } else if (is_swap_pte(ptent)) { 735 swp_entry_t swpent = pte_to_swp_entry(ptent); 736 737 if (is_pfn_swap_entry(swpent)) 738 page = pfn_swap_entry_to_page(swpent); 739 } 740 if (page) { 741 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte)) 742 mss->shared_hugetlb += huge_page_size(hstate_vma(vma)); 743 else 744 mss->private_hugetlb += huge_page_size(hstate_vma(vma)); 745 } 746 return 0; 747 } 748 #else 749 #define smaps_hugetlb_range NULL 750 #endif /* HUGETLB_PAGE */ 751 752 static const struct mm_walk_ops smaps_walk_ops = { 753 .pmd_entry = smaps_pte_range, 754 .hugetlb_entry = smaps_hugetlb_range, 755 .walk_lock = PGWALK_RDLOCK, 756 }; 757 758 static const struct mm_walk_ops smaps_shmem_walk_ops = { 759 .pmd_entry = smaps_pte_range, 760 .hugetlb_entry = smaps_hugetlb_range, 761 .pte_hole = smaps_pte_hole, 762 .walk_lock = PGWALK_RDLOCK, 763 }; 764 765 /* 766 * Gather mem stats from @vma with the indicated beginning 767 * address @start, and keep them in @mss. 768 * 769 * Use vm_start of @vma as the beginning address if @start is 0. 770 */ 771 static void smap_gather_stats(struct vm_area_struct *vma, 772 struct mem_size_stats *mss, unsigned long start) 773 { 774 const struct mm_walk_ops *ops = &smaps_walk_ops; 775 776 /* Invalid start */ 777 if (start >= vma->vm_end) 778 return; 779 780 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { 781 /* 782 * For shared or readonly shmem mappings we know that all 783 * swapped out pages belong to the shmem object, and we can 784 * obtain the swap value much more efficiently. For private 785 * writable mappings, we might have COW pages that are 786 * not affected by the parent swapped out pages of the shmem 787 * object, so we have to distinguish them during the page walk. 788 * Unless we know that the shmem object (or the part mapped by 789 * our VMA) has no swapped out pages at all. 790 */ 791 unsigned long shmem_swapped = shmem_swap_usage(vma); 792 793 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || 794 !(vma->vm_flags & VM_WRITE))) { 795 mss->swap += shmem_swapped; 796 } else { 797 ops = &smaps_shmem_walk_ops; 798 } 799 } 800 801 /* mmap_lock is held in m_start */ 802 if (!start) 803 walk_page_vma(vma, ops, mss); 804 else 805 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); 806 } 807 808 #define SEQ_PUT_DEC(str, val) \ 809 seq_put_decimal_ull_width(m, str, (val) >> 10, 8) 810 811 /* Show the contents common for smaps and smaps_rollup */ 812 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss, 813 bool rollup_mode) 814 { 815 SEQ_PUT_DEC("Rss: ", mss->resident); 816 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT); 817 SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT); 818 if (rollup_mode) { 819 /* 820 * These are meaningful only for smaps_rollup, otherwise two of 821 * them are zero, and the other one is the same as Pss. 822 */ 823 SEQ_PUT_DEC(" kB\nPss_Anon: ", 824 mss->pss_anon >> PSS_SHIFT); 825 SEQ_PUT_DEC(" kB\nPss_File: ", 826 mss->pss_file >> PSS_SHIFT); 827 SEQ_PUT_DEC(" kB\nPss_Shmem: ", 828 mss->pss_shmem >> PSS_SHIFT); 829 } 830 SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean); 831 SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty); 832 SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean); 833 SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty); 834 SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced); 835 SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous); 836 SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm); 837 SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree); 838 SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp); 839 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp); 840 SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp); 841 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb); 842 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ", 843 mss->private_hugetlb >> 10, 7); 844 SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); 845 SEQ_PUT_DEC(" kB\nSwapPss: ", 846 mss->swap_pss >> PSS_SHIFT); 847 SEQ_PUT_DEC(" kB\nLocked: ", 848 mss->pss_locked >> PSS_SHIFT); 849 seq_puts(m, " kB\n"); 850 } 851 852 static int show_smap(struct seq_file *m, void *v) 853 { 854 struct vm_area_struct *vma = v; 855 struct mem_size_stats mss = {}; 856 857 smap_gather_stats(vma, &mss, 0); 858 859 show_map_vma(m, vma); 860 861 SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start); 862 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma)); 863 SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma)); 864 seq_puts(m, " kB\n"); 865 866 __show_smap(m, &mss, false); 867 868 seq_printf(m, "THPeligible: %8u\n", 869 !!thp_vma_allowable_orders(vma, vma->vm_flags, true, false, 870 true, THP_ORDERS_ALL)); 871 872 if (arch_pkeys_enabled()) 873 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); 874 show_smap_vma_flags(m, vma); 875 876 return 0; 877 } 878 879 static int show_smaps_rollup(struct seq_file *m, void *v) 880 { 881 struct proc_maps_private *priv = m->private; 882 struct mem_size_stats mss = {}; 883 struct mm_struct *mm = priv->mm; 884 struct vm_area_struct *vma; 885 unsigned long vma_start = 0, last_vma_end = 0; 886 int ret = 0; 887 VMA_ITERATOR(vmi, mm, 0); 888 889 priv->task = get_proc_task(priv->inode); 890 if (!priv->task) 891 return -ESRCH; 892 893 if (!mm || !mmget_not_zero(mm)) { 894 ret = -ESRCH; 895 goto out_put_task; 896 } 897 898 ret = mmap_read_lock_killable(mm); 899 if (ret) 900 goto out_put_mm; 901 902 hold_task_mempolicy(priv); 903 vma = vma_next(&vmi); 904 905 if (unlikely(!vma)) 906 goto empty_set; 907 908 vma_start = vma->vm_start; 909 do { 910 smap_gather_stats(vma, &mss, 0); 911 last_vma_end = vma->vm_end; 912 913 /* 914 * Release mmap_lock temporarily if someone wants to 915 * access it for write request. 916 */ 917 if (mmap_lock_is_contended(mm)) { 918 vma_iter_invalidate(&vmi); 919 mmap_read_unlock(mm); 920 ret = mmap_read_lock_killable(mm); 921 if (ret) { 922 release_task_mempolicy(priv); 923 goto out_put_mm; 924 } 925 926 /* 927 * After dropping the lock, there are four cases to 928 * consider. See the following example for explanation. 929 * 930 * +------+------+-----------+ 931 * | VMA1 | VMA2 | VMA3 | 932 * +------+------+-----------+ 933 * | | | | 934 * 4k 8k 16k 400k 935 * 936 * Suppose we drop the lock after reading VMA2 due to 937 * contention, then we get: 938 * 939 * last_vma_end = 16k 940 * 941 * 1) VMA2 is freed, but VMA3 exists: 942 * 943 * vma_next(vmi) will return VMA3. 944 * In this case, just continue from VMA3. 945 * 946 * 2) VMA2 still exists: 947 * 948 * vma_next(vmi) will return VMA3. 949 * In this case, just continue from VMA3. 950 * 951 * 3) No more VMAs can be found: 952 * 953 * vma_next(vmi) will return NULL. 954 * No more things to do, just break. 955 * 956 * 4) (last_vma_end - 1) is the middle of a vma (VMA'): 957 * 958 * vma_next(vmi) will return VMA' whose range 959 * contains last_vma_end. 960 * Iterate VMA' from last_vma_end. 961 */ 962 vma = vma_next(&vmi); 963 /* Case 3 above */ 964 if (!vma) 965 break; 966 967 /* Case 1 and 2 above */ 968 if (vma->vm_start >= last_vma_end) 969 continue; 970 971 /* Case 4 above */ 972 if (vma->vm_end > last_vma_end) 973 smap_gather_stats(vma, &mss, last_vma_end); 974 } 975 } for_each_vma(vmi, vma); 976 977 empty_set: 978 show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0); 979 seq_pad(m, ' '); 980 seq_puts(m, "[rollup]\n"); 981 982 __show_smap(m, &mss, true); 983 984 release_task_mempolicy(priv); 985 mmap_read_unlock(mm); 986 987 out_put_mm: 988 mmput(mm); 989 out_put_task: 990 put_task_struct(priv->task); 991 priv->task = NULL; 992 993 return ret; 994 } 995 #undef SEQ_PUT_DEC 996 997 static const struct seq_operations proc_pid_smaps_op = { 998 .start = m_start, 999 .next = m_next, 1000 .stop = m_stop, 1001 .show = show_smap 1002 }; 1003 1004 static int pid_smaps_open(struct inode *inode, struct file *file) 1005 { 1006 return do_maps_open(inode, file, &proc_pid_smaps_op); 1007 } 1008 1009 static int smaps_rollup_open(struct inode *inode, struct file *file) 1010 { 1011 int ret; 1012 struct proc_maps_private *priv; 1013 1014 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT); 1015 if (!priv) 1016 return -ENOMEM; 1017 1018 ret = single_open(file, show_smaps_rollup, priv); 1019 if (ret) 1020 goto out_free; 1021 1022 priv->inode = inode; 1023 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 1024 if (IS_ERR(priv->mm)) { 1025 ret = PTR_ERR(priv->mm); 1026 1027 single_release(inode, file); 1028 goto out_free; 1029 } 1030 1031 return 0; 1032 1033 out_free: 1034 kfree(priv); 1035 return ret; 1036 } 1037 1038 static int smaps_rollup_release(struct inode *inode, struct file *file) 1039 { 1040 struct seq_file *seq = file->private_data; 1041 struct proc_maps_private *priv = seq->private; 1042 1043 if (priv->mm) 1044 mmdrop(priv->mm); 1045 1046 kfree(priv); 1047 return single_release(inode, file); 1048 } 1049 1050 const struct file_operations proc_pid_smaps_operations = { 1051 .open = pid_smaps_open, 1052 .read = seq_read, 1053 .llseek = seq_lseek, 1054 .release = proc_map_release, 1055 }; 1056 1057 const struct file_operations proc_pid_smaps_rollup_operations = { 1058 .open = smaps_rollup_open, 1059 .read = seq_read, 1060 .llseek = seq_lseek, 1061 .release = smaps_rollup_release, 1062 }; 1063 1064 enum clear_refs_types { 1065 CLEAR_REFS_ALL = 1, 1066 CLEAR_REFS_ANON, 1067 CLEAR_REFS_MAPPED, 1068 CLEAR_REFS_SOFT_DIRTY, 1069 CLEAR_REFS_MM_HIWATER_RSS, 1070 CLEAR_REFS_LAST, 1071 }; 1072 1073 struct clear_refs_private { 1074 enum clear_refs_types type; 1075 }; 1076 1077 #ifdef CONFIG_MEM_SOFT_DIRTY 1078 1079 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1080 { 1081 struct page *page; 1082 1083 if (!pte_write(pte)) 1084 return false; 1085 if (!is_cow_mapping(vma->vm_flags)) 1086 return false; 1087 if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))) 1088 return false; 1089 page = vm_normal_page(vma, addr, pte); 1090 if (!page) 1091 return false; 1092 return page_maybe_dma_pinned(page); 1093 } 1094 1095 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1096 unsigned long addr, pte_t *pte) 1097 { 1098 /* 1099 * The soft-dirty tracker uses #PF-s to catch writes 1100 * to pages, so write-protect the pte as well. See the 1101 * Documentation/admin-guide/mm/soft-dirty.rst for full description 1102 * of how soft-dirty works. 1103 */ 1104 pte_t ptent = ptep_get(pte); 1105 1106 if (pte_present(ptent)) { 1107 pte_t old_pte; 1108 1109 if (pte_is_pinned(vma, addr, ptent)) 1110 return; 1111 old_pte = ptep_modify_prot_start(vma, addr, pte); 1112 ptent = pte_wrprotect(old_pte); 1113 ptent = pte_clear_soft_dirty(ptent); 1114 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 1115 } else if (is_swap_pte(ptent)) { 1116 ptent = pte_swp_clear_soft_dirty(ptent); 1117 set_pte_at(vma->vm_mm, addr, pte, ptent); 1118 } 1119 } 1120 #else 1121 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1122 unsigned long addr, pte_t *pte) 1123 { 1124 } 1125 #endif 1126 1127 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 1128 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1129 unsigned long addr, pmd_t *pmdp) 1130 { 1131 pmd_t old, pmd = *pmdp; 1132 1133 if (pmd_present(pmd)) { 1134 /* See comment in change_huge_pmd() */ 1135 old = pmdp_invalidate(vma, addr, pmdp); 1136 if (pmd_dirty(old)) 1137 pmd = pmd_mkdirty(pmd); 1138 if (pmd_young(old)) 1139 pmd = pmd_mkyoung(pmd); 1140 1141 pmd = pmd_wrprotect(pmd); 1142 pmd = pmd_clear_soft_dirty(pmd); 1143 1144 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1145 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 1146 pmd = pmd_swp_clear_soft_dirty(pmd); 1147 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1148 } 1149 } 1150 #else 1151 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1152 unsigned long addr, pmd_t *pmdp) 1153 { 1154 } 1155 #endif 1156 1157 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 1158 unsigned long end, struct mm_walk *walk) 1159 { 1160 struct clear_refs_private *cp = walk->private; 1161 struct vm_area_struct *vma = walk->vma; 1162 pte_t *pte, ptent; 1163 spinlock_t *ptl; 1164 struct page *page; 1165 1166 ptl = pmd_trans_huge_lock(pmd, vma); 1167 if (ptl) { 1168 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1169 clear_soft_dirty_pmd(vma, addr, pmd); 1170 goto out; 1171 } 1172 1173 if (!pmd_present(*pmd)) 1174 goto out; 1175 1176 page = pmd_page(*pmd); 1177 1178 /* Clear accessed and referenced bits. */ 1179 pmdp_test_and_clear_young(vma, addr, pmd); 1180 test_and_clear_page_young(page); 1181 ClearPageReferenced(page); 1182 out: 1183 spin_unlock(ptl); 1184 return 0; 1185 } 1186 1187 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 1188 if (!pte) { 1189 walk->action = ACTION_AGAIN; 1190 return 0; 1191 } 1192 for (; addr != end; pte++, addr += PAGE_SIZE) { 1193 ptent = ptep_get(pte); 1194 1195 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1196 clear_soft_dirty(vma, addr, pte); 1197 continue; 1198 } 1199 1200 if (!pte_present(ptent)) 1201 continue; 1202 1203 page = vm_normal_page(vma, addr, ptent); 1204 if (!page) 1205 continue; 1206 1207 /* Clear accessed and referenced bits. */ 1208 ptep_test_and_clear_young(vma, addr, pte); 1209 test_and_clear_page_young(page); 1210 ClearPageReferenced(page); 1211 } 1212 pte_unmap_unlock(pte - 1, ptl); 1213 cond_resched(); 1214 return 0; 1215 } 1216 1217 static int clear_refs_test_walk(unsigned long start, unsigned long end, 1218 struct mm_walk *walk) 1219 { 1220 struct clear_refs_private *cp = walk->private; 1221 struct vm_area_struct *vma = walk->vma; 1222 1223 if (vma->vm_flags & VM_PFNMAP) 1224 return 1; 1225 1226 /* 1227 * Writing 1 to /proc/pid/clear_refs affects all pages. 1228 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. 1229 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. 1230 * Writing 4 to /proc/pid/clear_refs affects all pages. 1231 */ 1232 if (cp->type == CLEAR_REFS_ANON && vma->vm_file) 1233 return 1; 1234 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) 1235 return 1; 1236 return 0; 1237 } 1238 1239 static const struct mm_walk_ops clear_refs_walk_ops = { 1240 .pmd_entry = clear_refs_pte_range, 1241 .test_walk = clear_refs_test_walk, 1242 .walk_lock = PGWALK_WRLOCK, 1243 }; 1244 1245 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 1246 size_t count, loff_t *ppos) 1247 { 1248 struct task_struct *task; 1249 char buffer[PROC_NUMBUF] = {}; 1250 struct mm_struct *mm; 1251 struct vm_area_struct *vma; 1252 enum clear_refs_types type; 1253 int itype; 1254 int rv; 1255 1256 if (count > sizeof(buffer) - 1) 1257 count = sizeof(buffer) - 1; 1258 if (copy_from_user(buffer, buf, count)) 1259 return -EFAULT; 1260 rv = kstrtoint(strstrip(buffer), 10, &itype); 1261 if (rv < 0) 1262 return rv; 1263 type = (enum clear_refs_types)itype; 1264 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) 1265 return -EINVAL; 1266 1267 task = get_proc_task(file_inode(file)); 1268 if (!task) 1269 return -ESRCH; 1270 mm = get_task_mm(task); 1271 if (mm) { 1272 VMA_ITERATOR(vmi, mm, 0); 1273 struct mmu_notifier_range range; 1274 struct clear_refs_private cp = { 1275 .type = type, 1276 }; 1277 1278 if (mmap_write_lock_killable(mm)) { 1279 count = -EINTR; 1280 goto out_mm; 1281 } 1282 if (type == CLEAR_REFS_MM_HIWATER_RSS) { 1283 /* 1284 * Writing 5 to /proc/pid/clear_refs resets the peak 1285 * resident set size to this mm's current rss value. 1286 */ 1287 reset_mm_hiwater_rss(mm); 1288 goto out_unlock; 1289 } 1290 1291 if (type == CLEAR_REFS_SOFT_DIRTY) { 1292 for_each_vma(vmi, vma) { 1293 if (!(vma->vm_flags & VM_SOFTDIRTY)) 1294 continue; 1295 vm_flags_clear(vma, VM_SOFTDIRTY); 1296 vma_set_page_prot(vma); 1297 } 1298 1299 inc_tlb_flush_pending(mm); 1300 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 1301 0, mm, 0, -1UL); 1302 mmu_notifier_invalidate_range_start(&range); 1303 } 1304 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); 1305 if (type == CLEAR_REFS_SOFT_DIRTY) { 1306 mmu_notifier_invalidate_range_end(&range); 1307 flush_tlb_mm(mm); 1308 dec_tlb_flush_pending(mm); 1309 } 1310 out_unlock: 1311 mmap_write_unlock(mm); 1312 out_mm: 1313 mmput(mm); 1314 } 1315 put_task_struct(task); 1316 1317 return count; 1318 } 1319 1320 const struct file_operations proc_clear_refs_operations = { 1321 .write = clear_refs_write, 1322 .llseek = noop_llseek, 1323 }; 1324 1325 typedef struct { 1326 u64 pme; 1327 } pagemap_entry_t; 1328 1329 struct pagemapread { 1330 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */ 1331 pagemap_entry_t *buffer; 1332 bool show_pfn; 1333 }; 1334 1335 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 1336 #define PAGEMAP_WALK_MASK (PMD_MASK) 1337 1338 #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) 1339 #define PM_PFRAME_BITS 55 1340 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) 1341 #define PM_SOFT_DIRTY BIT_ULL(55) 1342 #define PM_MMAP_EXCLUSIVE BIT_ULL(56) 1343 #define PM_UFFD_WP BIT_ULL(57) 1344 #define PM_FILE BIT_ULL(61) 1345 #define PM_SWAP BIT_ULL(62) 1346 #define PM_PRESENT BIT_ULL(63) 1347 1348 #define PM_END_OF_BUFFER 1 1349 1350 static inline pagemap_entry_t make_pme(u64 frame, u64 flags) 1351 { 1352 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags }; 1353 } 1354 1355 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme, 1356 struct pagemapread *pm) 1357 { 1358 pm->buffer[pm->pos++] = *pme; 1359 if (pm->pos >= pm->len) 1360 return PM_END_OF_BUFFER; 1361 return 0; 1362 } 1363 1364 static int pagemap_pte_hole(unsigned long start, unsigned long end, 1365 __always_unused int depth, struct mm_walk *walk) 1366 { 1367 struct pagemapread *pm = walk->private; 1368 unsigned long addr = start; 1369 int err = 0; 1370 1371 while (addr < end) { 1372 struct vm_area_struct *vma = find_vma(walk->mm, addr); 1373 pagemap_entry_t pme = make_pme(0, 0); 1374 /* End of address space hole, which we mark as non-present. */ 1375 unsigned long hole_end; 1376 1377 if (vma) 1378 hole_end = min(end, vma->vm_start); 1379 else 1380 hole_end = end; 1381 1382 for (; addr < hole_end; addr += PAGE_SIZE) { 1383 err = add_to_pagemap(addr, &pme, pm); 1384 if (err) 1385 goto out; 1386 } 1387 1388 if (!vma) 1389 break; 1390 1391 /* Addresses in the VMA. */ 1392 if (vma->vm_flags & VM_SOFTDIRTY) 1393 pme = make_pme(0, PM_SOFT_DIRTY); 1394 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { 1395 err = add_to_pagemap(addr, &pme, pm); 1396 if (err) 1397 goto out; 1398 } 1399 } 1400 out: 1401 return err; 1402 } 1403 1404 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 1405 struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1406 { 1407 u64 frame = 0, flags = 0; 1408 struct page *page = NULL; 1409 bool migration = false; 1410 1411 if (pte_present(pte)) { 1412 if (pm->show_pfn) 1413 frame = pte_pfn(pte); 1414 flags |= PM_PRESENT; 1415 page = vm_normal_page(vma, addr, pte); 1416 if (pte_soft_dirty(pte)) 1417 flags |= PM_SOFT_DIRTY; 1418 if (pte_uffd_wp(pte)) 1419 flags |= PM_UFFD_WP; 1420 } else if (is_swap_pte(pte)) { 1421 swp_entry_t entry; 1422 if (pte_swp_soft_dirty(pte)) 1423 flags |= PM_SOFT_DIRTY; 1424 if (pte_swp_uffd_wp(pte)) 1425 flags |= PM_UFFD_WP; 1426 entry = pte_to_swp_entry(pte); 1427 if (pm->show_pfn) { 1428 pgoff_t offset; 1429 /* 1430 * For PFN swap offsets, keeping the offset field 1431 * to be PFN only to be compatible with old smaps. 1432 */ 1433 if (is_pfn_swap_entry(entry)) 1434 offset = swp_offset_pfn(entry); 1435 else 1436 offset = swp_offset(entry); 1437 frame = swp_type(entry) | 1438 (offset << MAX_SWAPFILES_SHIFT); 1439 } 1440 flags |= PM_SWAP; 1441 migration = is_migration_entry(entry); 1442 if (is_pfn_swap_entry(entry)) 1443 page = pfn_swap_entry_to_page(entry); 1444 if (pte_marker_entry_uffd_wp(entry)) 1445 flags |= PM_UFFD_WP; 1446 } 1447 1448 if (page && !PageAnon(page)) 1449 flags |= PM_FILE; 1450 if (page && !migration && page_mapcount(page) == 1) 1451 flags |= PM_MMAP_EXCLUSIVE; 1452 if (vma->vm_flags & VM_SOFTDIRTY) 1453 flags |= PM_SOFT_DIRTY; 1454 1455 return make_pme(frame, flags); 1456 } 1457 1458 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, 1459 struct mm_walk *walk) 1460 { 1461 struct vm_area_struct *vma = walk->vma; 1462 struct pagemapread *pm = walk->private; 1463 spinlock_t *ptl; 1464 pte_t *pte, *orig_pte; 1465 int err = 0; 1466 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1467 bool migration = false; 1468 1469 ptl = pmd_trans_huge_lock(pmdp, vma); 1470 if (ptl) { 1471 u64 flags = 0, frame = 0; 1472 pmd_t pmd = *pmdp; 1473 struct page *page = NULL; 1474 1475 if (vma->vm_flags & VM_SOFTDIRTY) 1476 flags |= PM_SOFT_DIRTY; 1477 1478 if (pmd_present(pmd)) { 1479 page = pmd_page(pmd); 1480 1481 flags |= PM_PRESENT; 1482 if (pmd_soft_dirty(pmd)) 1483 flags |= PM_SOFT_DIRTY; 1484 if (pmd_uffd_wp(pmd)) 1485 flags |= PM_UFFD_WP; 1486 if (pm->show_pfn) 1487 frame = pmd_pfn(pmd) + 1488 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1489 } 1490 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1491 else if (is_swap_pmd(pmd)) { 1492 swp_entry_t entry = pmd_to_swp_entry(pmd); 1493 unsigned long offset; 1494 1495 if (pm->show_pfn) { 1496 if (is_pfn_swap_entry(entry)) 1497 offset = swp_offset_pfn(entry); 1498 else 1499 offset = swp_offset(entry); 1500 offset = offset + 1501 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1502 frame = swp_type(entry) | 1503 (offset << MAX_SWAPFILES_SHIFT); 1504 } 1505 flags |= PM_SWAP; 1506 if (pmd_swp_soft_dirty(pmd)) 1507 flags |= PM_SOFT_DIRTY; 1508 if (pmd_swp_uffd_wp(pmd)) 1509 flags |= PM_UFFD_WP; 1510 VM_BUG_ON(!is_pmd_migration_entry(pmd)); 1511 migration = is_migration_entry(entry); 1512 page = pfn_swap_entry_to_page(entry); 1513 } 1514 #endif 1515 1516 if (page && !migration && page_mapcount(page) == 1) 1517 flags |= PM_MMAP_EXCLUSIVE; 1518 1519 for (; addr != end; addr += PAGE_SIZE) { 1520 pagemap_entry_t pme = make_pme(frame, flags); 1521 1522 err = add_to_pagemap(addr, &pme, pm); 1523 if (err) 1524 break; 1525 if (pm->show_pfn) { 1526 if (flags & PM_PRESENT) 1527 frame++; 1528 else if (flags & PM_SWAP) 1529 frame += (1 << MAX_SWAPFILES_SHIFT); 1530 } 1531 } 1532 spin_unlock(ptl); 1533 return err; 1534 } 1535 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1536 1537 /* 1538 * We can assume that @vma always points to a valid one and @end never 1539 * goes beyond vma->vm_end. 1540 */ 1541 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); 1542 if (!pte) { 1543 walk->action = ACTION_AGAIN; 1544 return err; 1545 } 1546 for (; addr < end; pte++, addr += PAGE_SIZE) { 1547 pagemap_entry_t pme; 1548 1549 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte)); 1550 err = add_to_pagemap(addr, &pme, pm); 1551 if (err) 1552 break; 1553 } 1554 pte_unmap_unlock(orig_pte, ptl); 1555 1556 cond_resched(); 1557 1558 return err; 1559 } 1560 1561 #ifdef CONFIG_HUGETLB_PAGE 1562 /* This function walks within one hugetlb entry in the single call */ 1563 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 1564 unsigned long addr, unsigned long end, 1565 struct mm_walk *walk) 1566 { 1567 struct pagemapread *pm = walk->private; 1568 struct vm_area_struct *vma = walk->vma; 1569 u64 flags = 0, frame = 0; 1570 int err = 0; 1571 pte_t pte; 1572 1573 if (vma->vm_flags & VM_SOFTDIRTY) 1574 flags |= PM_SOFT_DIRTY; 1575 1576 pte = huge_ptep_get(ptep); 1577 if (pte_present(pte)) { 1578 struct page *page = pte_page(pte); 1579 1580 if (!PageAnon(page)) 1581 flags |= PM_FILE; 1582 1583 if (page_mapcount(page) == 1) 1584 flags |= PM_MMAP_EXCLUSIVE; 1585 1586 if (huge_pte_uffd_wp(pte)) 1587 flags |= PM_UFFD_WP; 1588 1589 flags |= PM_PRESENT; 1590 if (pm->show_pfn) 1591 frame = pte_pfn(pte) + 1592 ((addr & ~hmask) >> PAGE_SHIFT); 1593 } else if (pte_swp_uffd_wp_any(pte)) { 1594 flags |= PM_UFFD_WP; 1595 } 1596 1597 for (; addr != end; addr += PAGE_SIZE) { 1598 pagemap_entry_t pme = make_pme(frame, flags); 1599 1600 err = add_to_pagemap(addr, &pme, pm); 1601 if (err) 1602 return err; 1603 if (pm->show_pfn && (flags & PM_PRESENT)) 1604 frame++; 1605 } 1606 1607 cond_resched(); 1608 1609 return err; 1610 } 1611 #else 1612 #define pagemap_hugetlb_range NULL 1613 #endif /* HUGETLB_PAGE */ 1614 1615 static const struct mm_walk_ops pagemap_ops = { 1616 .pmd_entry = pagemap_pmd_range, 1617 .pte_hole = pagemap_pte_hole, 1618 .hugetlb_entry = pagemap_hugetlb_range, 1619 .walk_lock = PGWALK_RDLOCK, 1620 }; 1621 1622 /* 1623 * /proc/pid/pagemap - an array mapping virtual pages to pfns 1624 * 1625 * For each page in the address space, this file contains one 64-bit entry 1626 * consisting of the following: 1627 * 1628 * Bits 0-54 page frame number (PFN) if present 1629 * Bits 0-4 swap type if swapped 1630 * Bits 5-54 swap offset if swapped 1631 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) 1632 * Bit 56 page exclusively mapped 1633 * Bit 57 pte is uffd-wp write-protected 1634 * Bits 58-60 zero 1635 * Bit 61 page is file-page or shared-anon 1636 * Bit 62 page swapped 1637 * Bit 63 page present 1638 * 1639 * If the page is not present but in swap, then the PFN contains an 1640 * encoding of the swap file number and the page's offset into the 1641 * swap. Unmapped pages return a null PFN. This allows determining 1642 * precisely which pages are mapped (or in swap) and comparing mapped 1643 * pages between processes. 1644 * 1645 * Efficient users of this interface will use /proc/pid/maps to 1646 * determine which areas of memory are actually mapped and llseek to 1647 * skip over unmapped regions. 1648 */ 1649 static ssize_t pagemap_read(struct file *file, char __user *buf, 1650 size_t count, loff_t *ppos) 1651 { 1652 struct mm_struct *mm = file->private_data; 1653 struct pagemapread pm; 1654 unsigned long src; 1655 unsigned long svpfn; 1656 unsigned long start_vaddr; 1657 unsigned long end_vaddr; 1658 int ret = 0, copied = 0; 1659 1660 if (!mm || !mmget_not_zero(mm)) 1661 goto out; 1662 1663 ret = -EINVAL; 1664 /* file position must be aligned */ 1665 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 1666 goto out_mm; 1667 1668 ret = 0; 1669 if (!count) 1670 goto out_mm; 1671 1672 /* do not disclose physical addresses: attack vector */ 1673 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); 1674 1675 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 1676 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); 1677 ret = -ENOMEM; 1678 if (!pm.buffer) 1679 goto out_mm; 1680 1681 src = *ppos; 1682 svpfn = src / PM_ENTRY_BYTES; 1683 end_vaddr = mm->task_size; 1684 1685 /* watch out for wraparound */ 1686 start_vaddr = end_vaddr; 1687 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) { 1688 unsigned long end; 1689 1690 ret = mmap_read_lock_killable(mm); 1691 if (ret) 1692 goto out_free; 1693 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT); 1694 mmap_read_unlock(mm); 1695 1696 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT); 1697 if (end >= start_vaddr && end < mm->task_size) 1698 end_vaddr = end; 1699 } 1700 1701 /* Ensure the address is inside the task */ 1702 if (start_vaddr > mm->task_size) 1703 start_vaddr = end_vaddr; 1704 1705 ret = 0; 1706 while (count && (start_vaddr < end_vaddr)) { 1707 int len; 1708 unsigned long end; 1709 1710 pm.pos = 0; 1711 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 1712 /* overflow ? */ 1713 if (end < start_vaddr || end > end_vaddr) 1714 end = end_vaddr; 1715 ret = mmap_read_lock_killable(mm); 1716 if (ret) 1717 goto out_free; 1718 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm); 1719 mmap_read_unlock(mm); 1720 start_vaddr = end; 1721 1722 len = min(count, PM_ENTRY_BYTES * pm.pos); 1723 if (copy_to_user(buf, pm.buffer, len)) { 1724 ret = -EFAULT; 1725 goto out_free; 1726 } 1727 copied += len; 1728 buf += len; 1729 count -= len; 1730 } 1731 *ppos += copied; 1732 if (!ret || ret == PM_END_OF_BUFFER) 1733 ret = copied; 1734 1735 out_free: 1736 kfree(pm.buffer); 1737 out_mm: 1738 mmput(mm); 1739 out: 1740 return ret; 1741 } 1742 1743 static int pagemap_open(struct inode *inode, struct file *file) 1744 { 1745 struct mm_struct *mm; 1746 1747 mm = proc_mem_open(inode, PTRACE_MODE_READ); 1748 if (IS_ERR(mm)) 1749 return PTR_ERR(mm); 1750 file->private_data = mm; 1751 return 0; 1752 } 1753 1754 static int pagemap_release(struct inode *inode, struct file *file) 1755 { 1756 struct mm_struct *mm = file->private_data; 1757 1758 if (mm) 1759 mmdrop(mm); 1760 return 0; 1761 } 1762 1763 #define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \ 1764 PAGE_IS_FILE | PAGE_IS_PRESENT | \ 1765 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \ 1766 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY) 1767 #define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC) 1768 1769 struct pagemap_scan_private { 1770 struct pm_scan_arg arg; 1771 unsigned long masks_of_interest, cur_vma_category; 1772 struct page_region *vec_buf; 1773 unsigned long vec_buf_len, vec_buf_index, found_pages; 1774 struct page_region __user *vec_out; 1775 }; 1776 1777 static unsigned long pagemap_page_category(struct pagemap_scan_private *p, 1778 struct vm_area_struct *vma, 1779 unsigned long addr, pte_t pte) 1780 { 1781 unsigned long categories = 0; 1782 1783 if (pte_present(pte)) { 1784 struct page *page; 1785 1786 categories |= PAGE_IS_PRESENT; 1787 if (!pte_uffd_wp(pte)) 1788 categories |= PAGE_IS_WRITTEN; 1789 1790 if (p->masks_of_interest & PAGE_IS_FILE) { 1791 page = vm_normal_page(vma, addr, pte); 1792 if (page && !PageAnon(page)) 1793 categories |= PAGE_IS_FILE; 1794 } 1795 1796 if (is_zero_pfn(pte_pfn(pte))) 1797 categories |= PAGE_IS_PFNZERO; 1798 if (pte_soft_dirty(pte)) 1799 categories |= PAGE_IS_SOFT_DIRTY; 1800 } else if (is_swap_pte(pte)) { 1801 swp_entry_t swp; 1802 1803 categories |= PAGE_IS_SWAPPED; 1804 if (!pte_swp_uffd_wp_any(pte)) 1805 categories |= PAGE_IS_WRITTEN; 1806 1807 if (p->masks_of_interest & PAGE_IS_FILE) { 1808 swp = pte_to_swp_entry(pte); 1809 if (is_pfn_swap_entry(swp) && 1810 !PageAnon(pfn_swap_entry_to_page(swp))) 1811 categories |= PAGE_IS_FILE; 1812 } 1813 if (pte_swp_soft_dirty(pte)) 1814 categories |= PAGE_IS_SOFT_DIRTY; 1815 } 1816 1817 return categories; 1818 } 1819 1820 static void make_uffd_wp_pte(struct vm_area_struct *vma, 1821 unsigned long addr, pte_t *pte) 1822 { 1823 pte_t ptent = ptep_get(pte); 1824 1825 if (pte_present(ptent)) { 1826 pte_t old_pte; 1827 1828 old_pte = ptep_modify_prot_start(vma, addr, pte); 1829 ptent = pte_mkuffd_wp(ptent); 1830 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 1831 } else if (is_swap_pte(ptent)) { 1832 ptent = pte_swp_mkuffd_wp(ptent); 1833 set_pte_at(vma->vm_mm, addr, pte, ptent); 1834 } else { 1835 set_pte_at(vma->vm_mm, addr, pte, 1836 make_pte_marker(PTE_MARKER_UFFD_WP)); 1837 } 1838 } 1839 1840 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1841 static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, 1842 struct vm_area_struct *vma, 1843 unsigned long addr, pmd_t pmd) 1844 { 1845 unsigned long categories = PAGE_IS_HUGE; 1846 1847 if (pmd_present(pmd)) { 1848 struct page *page; 1849 1850 categories |= PAGE_IS_PRESENT; 1851 if (!pmd_uffd_wp(pmd)) 1852 categories |= PAGE_IS_WRITTEN; 1853 1854 if (p->masks_of_interest & PAGE_IS_FILE) { 1855 page = vm_normal_page_pmd(vma, addr, pmd); 1856 if (page && !PageAnon(page)) 1857 categories |= PAGE_IS_FILE; 1858 } 1859 1860 if (is_zero_pfn(pmd_pfn(pmd))) 1861 categories |= PAGE_IS_PFNZERO; 1862 if (pmd_soft_dirty(pmd)) 1863 categories |= PAGE_IS_SOFT_DIRTY; 1864 } else if (is_swap_pmd(pmd)) { 1865 swp_entry_t swp; 1866 1867 categories |= PAGE_IS_SWAPPED; 1868 if (!pmd_swp_uffd_wp(pmd)) 1869 categories |= PAGE_IS_WRITTEN; 1870 if (pmd_swp_soft_dirty(pmd)) 1871 categories |= PAGE_IS_SOFT_DIRTY; 1872 1873 if (p->masks_of_interest & PAGE_IS_FILE) { 1874 swp = pmd_to_swp_entry(pmd); 1875 if (is_pfn_swap_entry(swp) && 1876 !PageAnon(pfn_swap_entry_to_page(swp))) 1877 categories |= PAGE_IS_FILE; 1878 } 1879 } 1880 1881 return categories; 1882 } 1883 1884 static void make_uffd_wp_pmd(struct vm_area_struct *vma, 1885 unsigned long addr, pmd_t *pmdp) 1886 { 1887 pmd_t old, pmd = *pmdp; 1888 1889 if (pmd_present(pmd)) { 1890 old = pmdp_invalidate_ad(vma, addr, pmdp); 1891 pmd = pmd_mkuffd_wp(old); 1892 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1893 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 1894 pmd = pmd_swp_mkuffd_wp(pmd); 1895 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1896 } 1897 } 1898 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1899 1900 #ifdef CONFIG_HUGETLB_PAGE 1901 static unsigned long pagemap_hugetlb_category(pte_t pte) 1902 { 1903 unsigned long categories = PAGE_IS_HUGE; 1904 1905 /* 1906 * According to pagemap_hugetlb_range(), file-backed HugeTLB 1907 * page cannot be swapped. So PAGE_IS_FILE is not checked for 1908 * swapped pages. 1909 */ 1910 if (pte_present(pte)) { 1911 categories |= PAGE_IS_PRESENT; 1912 if (!huge_pte_uffd_wp(pte)) 1913 categories |= PAGE_IS_WRITTEN; 1914 if (!PageAnon(pte_page(pte))) 1915 categories |= PAGE_IS_FILE; 1916 if (is_zero_pfn(pte_pfn(pte))) 1917 categories |= PAGE_IS_PFNZERO; 1918 if (pte_soft_dirty(pte)) 1919 categories |= PAGE_IS_SOFT_DIRTY; 1920 } else if (is_swap_pte(pte)) { 1921 categories |= PAGE_IS_SWAPPED; 1922 if (!pte_swp_uffd_wp_any(pte)) 1923 categories |= PAGE_IS_WRITTEN; 1924 if (pte_swp_soft_dirty(pte)) 1925 categories |= PAGE_IS_SOFT_DIRTY; 1926 } 1927 1928 return categories; 1929 } 1930 1931 static void make_uffd_wp_huge_pte(struct vm_area_struct *vma, 1932 unsigned long addr, pte_t *ptep, 1933 pte_t ptent) 1934 { 1935 unsigned long psize; 1936 1937 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) 1938 return; 1939 1940 psize = huge_page_size(hstate_vma(vma)); 1941 1942 if (is_hugetlb_entry_migration(ptent)) 1943 set_huge_pte_at(vma->vm_mm, addr, ptep, 1944 pte_swp_mkuffd_wp(ptent), psize); 1945 else if (!huge_pte_none(ptent)) 1946 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, 1947 huge_pte_mkuffd_wp(ptent)); 1948 else 1949 set_huge_pte_at(vma->vm_mm, addr, ptep, 1950 make_pte_marker(PTE_MARKER_UFFD_WP), psize); 1951 } 1952 #endif /* CONFIG_HUGETLB_PAGE */ 1953 1954 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) 1955 static void pagemap_scan_backout_range(struct pagemap_scan_private *p, 1956 unsigned long addr, unsigned long end) 1957 { 1958 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 1959 1960 if (cur_buf->start != addr) 1961 cur_buf->end = addr; 1962 else 1963 cur_buf->start = cur_buf->end = 0; 1964 1965 p->found_pages -= (end - addr) / PAGE_SIZE; 1966 } 1967 #endif 1968 1969 static bool pagemap_scan_is_interesting_page(unsigned long categories, 1970 const struct pagemap_scan_private *p) 1971 { 1972 categories ^= p->arg.category_inverted; 1973 if ((categories & p->arg.category_mask) != p->arg.category_mask) 1974 return false; 1975 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask)) 1976 return false; 1977 1978 return true; 1979 } 1980 1981 static bool pagemap_scan_is_interesting_vma(unsigned long categories, 1982 const struct pagemap_scan_private *p) 1983 { 1984 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED; 1985 1986 categories ^= p->arg.category_inverted; 1987 if ((categories & required) != required) 1988 return false; 1989 1990 return true; 1991 } 1992 1993 static int pagemap_scan_test_walk(unsigned long start, unsigned long end, 1994 struct mm_walk *walk) 1995 { 1996 struct pagemap_scan_private *p = walk->private; 1997 struct vm_area_struct *vma = walk->vma; 1998 unsigned long vma_category = 0; 1999 bool wp_allowed = userfaultfd_wp_async(vma) && 2000 userfaultfd_wp_use_markers(vma); 2001 2002 if (!wp_allowed) { 2003 /* User requested explicit failure over wp-async capability */ 2004 if (p->arg.flags & PM_SCAN_CHECK_WPASYNC) 2005 return -EPERM; 2006 /* 2007 * User requires wr-protect, and allows silently skipping 2008 * unsupported vmas. 2009 */ 2010 if (p->arg.flags & PM_SCAN_WP_MATCHING) 2011 return 1; 2012 /* 2013 * Then the request doesn't involve wr-protects at all, 2014 * fall through to the rest checks, and allow vma walk. 2015 */ 2016 } 2017 2018 if (vma->vm_flags & VM_PFNMAP) 2019 return 1; 2020 2021 if (wp_allowed) 2022 vma_category |= PAGE_IS_WPALLOWED; 2023 2024 if (vma->vm_flags & VM_SOFTDIRTY) 2025 vma_category |= PAGE_IS_SOFT_DIRTY; 2026 2027 if (!pagemap_scan_is_interesting_vma(vma_category, p)) 2028 return 1; 2029 2030 p->cur_vma_category = vma_category; 2031 2032 return 0; 2033 } 2034 2035 static bool pagemap_scan_push_range(unsigned long categories, 2036 struct pagemap_scan_private *p, 2037 unsigned long addr, unsigned long end) 2038 { 2039 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2040 2041 /* 2042 * When there is no output buffer provided at all, the sentinel values 2043 * won't match here. There is no other way for `cur_buf->end` to be 2044 * non-zero other than it being non-empty. 2045 */ 2046 if (addr == cur_buf->end && categories == cur_buf->categories) { 2047 cur_buf->end = end; 2048 return true; 2049 } 2050 2051 if (cur_buf->end) { 2052 if (p->vec_buf_index >= p->vec_buf_len - 1) 2053 return false; 2054 2055 cur_buf = &p->vec_buf[++p->vec_buf_index]; 2056 } 2057 2058 cur_buf->start = addr; 2059 cur_buf->end = end; 2060 cur_buf->categories = categories; 2061 2062 return true; 2063 } 2064 2065 static int pagemap_scan_output(unsigned long categories, 2066 struct pagemap_scan_private *p, 2067 unsigned long addr, unsigned long *end) 2068 { 2069 unsigned long n_pages, total_pages; 2070 int ret = 0; 2071 2072 if (!p->vec_buf) 2073 return 0; 2074 2075 categories &= p->arg.return_mask; 2076 2077 n_pages = (*end - addr) / PAGE_SIZE; 2078 if (check_add_overflow(p->found_pages, n_pages, &total_pages) || 2079 total_pages > p->arg.max_pages) { 2080 size_t n_too_much = total_pages - p->arg.max_pages; 2081 *end -= n_too_much * PAGE_SIZE; 2082 n_pages -= n_too_much; 2083 ret = -ENOSPC; 2084 } 2085 2086 if (!pagemap_scan_push_range(categories, p, addr, *end)) { 2087 *end = addr; 2088 n_pages = 0; 2089 ret = -ENOSPC; 2090 } 2091 2092 p->found_pages += n_pages; 2093 if (ret) 2094 p->arg.walk_end = *end; 2095 2096 return ret; 2097 } 2098 2099 static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start, 2100 unsigned long end, struct mm_walk *walk) 2101 { 2102 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2103 struct pagemap_scan_private *p = walk->private; 2104 struct vm_area_struct *vma = walk->vma; 2105 unsigned long categories; 2106 spinlock_t *ptl; 2107 int ret = 0; 2108 2109 ptl = pmd_trans_huge_lock(pmd, vma); 2110 if (!ptl) 2111 return -ENOENT; 2112 2113 categories = p->cur_vma_category | 2114 pagemap_thp_category(p, vma, start, *pmd); 2115 2116 if (!pagemap_scan_is_interesting_page(categories, p)) 2117 goto out_unlock; 2118 2119 ret = pagemap_scan_output(categories, p, start, &end); 2120 if (start == end) 2121 goto out_unlock; 2122 2123 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2124 goto out_unlock; 2125 if (~categories & PAGE_IS_WRITTEN) 2126 goto out_unlock; 2127 2128 /* 2129 * Break huge page into small pages if the WP operation 2130 * needs to be performed on a portion of the huge page. 2131 */ 2132 if (end != start + HPAGE_SIZE) { 2133 spin_unlock(ptl); 2134 split_huge_pmd(vma, pmd, start); 2135 pagemap_scan_backout_range(p, start, end); 2136 /* Report as if there was no THP */ 2137 return -ENOENT; 2138 } 2139 2140 make_uffd_wp_pmd(vma, start, pmd); 2141 flush_tlb_range(vma, start, end); 2142 out_unlock: 2143 spin_unlock(ptl); 2144 return ret; 2145 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 2146 return -ENOENT; 2147 #endif 2148 } 2149 2150 static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, 2151 unsigned long end, struct mm_walk *walk) 2152 { 2153 struct pagemap_scan_private *p = walk->private; 2154 struct vm_area_struct *vma = walk->vma; 2155 unsigned long addr, flush_end = 0; 2156 pte_t *pte, *start_pte; 2157 spinlock_t *ptl; 2158 int ret; 2159 2160 arch_enter_lazy_mmu_mode(); 2161 2162 ret = pagemap_scan_thp_entry(pmd, start, end, walk); 2163 if (ret != -ENOENT) { 2164 arch_leave_lazy_mmu_mode(); 2165 return ret; 2166 } 2167 2168 ret = 0; 2169 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); 2170 if (!pte) { 2171 arch_leave_lazy_mmu_mode(); 2172 walk->action = ACTION_AGAIN; 2173 return 0; 2174 } 2175 2176 if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { 2177 /* Fast path for performing exclusive WP */ 2178 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2179 if (pte_uffd_wp(ptep_get(pte))) 2180 continue; 2181 make_uffd_wp_pte(vma, addr, pte); 2182 if (!flush_end) 2183 start = addr; 2184 flush_end = addr + PAGE_SIZE; 2185 } 2186 goto flush_and_return; 2187 } 2188 2189 if (!p->arg.category_anyof_mask && !p->arg.category_inverted && 2190 p->arg.category_mask == PAGE_IS_WRITTEN && 2191 p->arg.return_mask == PAGE_IS_WRITTEN) { 2192 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) { 2193 unsigned long next = addr + PAGE_SIZE; 2194 2195 if (pte_uffd_wp(ptep_get(pte))) 2196 continue; 2197 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN, 2198 p, addr, &next); 2199 if (next == addr) 2200 break; 2201 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2202 continue; 2203 make_uffd_wp_pte(vma, addr, pte); 2204 if (!flush_end) 2205 start = addr; 2206 flush_end = next; 2207 } 2208 goto flush_and_return; 2209 } 2210 2211 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2212 unsigned long categories = p->cur_vma_category | 2213 pagemap_page_category(p, vma, addr, ptep_get(pte)); 2214 unsigned long next = addr + PAGE_SIZE; 2215 2216 if (!pagemap_scan_is_interesting_page(categories, p)) 2217 continue; 2218 2219 ret = pagemap_scan_output(categories, p, addr, &next); 2220 if (next == addr) 2221 break; 2222 2223 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2224 continue; 2225 if (~categories & PAGE_IS_WRITTEN) 2226 continue; 2227 2228 make_uffd_wp_pte(vma, addr, pte); 2229 if (!flush_end) 2230 start = addr; 2231 flush_end = next; 2232 } 2233 2234 flush_and_return: 2235 if (flush_end) 2236 flush_tlb_range(vma, start, addr); 2237 2238 pte_unmap_unlock(start_pte, ptl); 2239 arch_leave_lazy_mmu_mode(); 2240 2241 cond_resched(); 2242 return ret; 2243 } 2244 2245 #ifdef CONFIG_HUGETLB_PAGE 2246 static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, 2247 unsigned long start, unsigned long end, 2248 struct mm_walk *walk) 2249 { 2250 struct pagemap_scan_private *p = walk->private; 2251 struct vm_area_struct *vma = walk->vma; 2252 unsigned long categories; 2253 spinlock_t *ptl; 2254 int ret = 0; 2255 pte_t pte; 2256 2257 if (~p->arg.flags & PM_SCAN_WP_MATCHING) { 2258 /* Go the short route when not write-protecting pages. */ 2259 2260 pte = huge_ptep_get(ptep); 2261 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2262 2263 if (!pagemap_scan_is_interesting_page(categories, p)) 2264 return 0; 2265 2266 return pagemap_scan_output(categories, p, start, &end); 2267 } 2268 2269 i_mmap_lock_write(vma->vm_file->f_mapping); 2270 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep); 2271 2272 pte = huge_ptep_get(ptep); 2273 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2274 2275 if (!pagemap_scan_is_interesting_page(categories, p)) 2276 goto out_unlock; 2277 2278 ret = pagemap_scan_output(categories, p, start, &end); 2279 if (start == end) 2280 goto out_unlock; 2281 2282 if (~categories & PAGE_IS_WRITTEN) 2283 goto out_unlock; 2284 2285 if (end != start + HPAGE_SIZE) { 2286 /* Partial HugeTLB page WP isn't possible. */ 2287 pagemap_scan_backout_range(p, start, end); 2288 p->arg.walk_end = start; 2289 ret = 0; 2290 goto out_unlock; 2291 } 2292 2293 make_uffd_wp_huge_pte(vma, start, ptep, pte); 2294 flush_hugetlb_tlb_range(vma, start, end); 2295 2296 out_unlock: 2297 spin_unlock(ptl); 2298 i_mmap_unlock_write(vma->vm_file->f_mapping); 2299 2300 return ret; 2301 } 2302 #else 2303 #define pagemap_scan_hugetlb_entry NULL 2304 #endif 2305 2306 static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, 2307 int depth, struct mm_walk *walk) 2308 { 2309 struct pagemap_scan_private *p = walk->private; 2310 struct vm_area_struct *vma = walk->vma; 2311 int ret, err; 2312 2313 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p)) 2314 return 0; 2315 2316 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end); 2317 if (addr == end) 2318 return ret; 2319 2320 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2321 return ret; 2322 2323 err = uffd_wp_range(vma, addr, end - addr, true); 2324 if (err < 0) 2325 ret = err; 2326 2327 return ret; 2328 } 2329 2330 static const struct mm_walk_ops pagemap_scan_ops = { 2331 .test_walk = pagemap_scan_test_walk, 2332 .pmd_entry = pagemap_scan_pmd_entry, 2333 .pte_hole = pagemap_scan_pte_hole, 2334 .hugetlb_entry = pagemap_scan_hugetlb_entry, 2335 }; 2336 2337 static int pagemap_scan_get_args(struct pm_scan_arg *arg, 2338 unsigned long uarg) 2339 { 2340 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg))) 2341 return -EFAULT; 2342 2343 if (arg->size != sizeof(struct pm_scan_arg)) 2344 return -EINVAL; 2345 2346 /* Validate requested features */ 2347 if (arg->flags & ~PM_SCAN_FLAGS) 2348 return -EINVAL; 2349 if ((arg->category_inverted | arg->category_mask | 2350 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) 2351 return -EINVAL; 2352 2353 arg->start = untagged_addr((unsigned long)arg->start); 2354 arg->end = untagged_addr((unsigned long)arg->end); 2355 arg->vec = untagged_addr((unsigned long)arg->vec); 2356 2357 /* Validate memory pointers */ 2358 if (!IS_ALIGNED(arg->start, PAGE_SIZE)) 2359 return -EINVAL; 2360 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start)) 2361 return -EFAULT; 2362 if (!arg->vec && arg->vec_len) 2363 return -EINVAL; 2364 if (arg->vec && !access_ok((void __user *)(long)arg->vec, 2365 arg->vec_len * sizeof(struct page_region))) 2366 return -EFAULT; 2367 2368 /* Fixup default values */ 2369 arg->end = ALIGN(arg->end, PAGE_SIZE); 2370 arg->walk_end = 0; 2371 if (!arg->max_pages) 2372 arg->max_pages = ULONG_MAX; 2373 2374 return 0; 2375 } 2376 2377 static int pagemap_scan_writeback_args(struct pm_scan_arg *arg, 2378 unsigned long uargl) 2379 { 2380 struct pm_scan_arg __user *uarg = (void __user *)uargl; 2381 2382 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end))) 2383 return -EFAULT; 2384 2385 return 0; 2386 } 2387 2388 static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p) 2389 { 2390 if (!p->arg.vec_len) 2391 return 0; 2392 2393 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT, 2394 p->arg.vec_len); 2395 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf), 2396 GFP_KERNEL); 2397 if (!p->vec_buf) 2398 return -ENOMEM; 2399 2400 p->vec_buf->start = p->vec_buf->end = 0; 2401 p->vec_out = (struct page_region __user *)(long)p->arg.vec; 2402 2403 return 0; 2404 } 2405 2406 static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p) 2407 { 2408 const struct page_region *buf = p->vec_buf; 2409 long n = p->vec_buf_index; 2410 2411 if (!p->vec_buf) 2412 return 0; 2413 2414 if (buf[n].end != buf[n].start) 2415 n++; 2416 2417 if (!n) 2418 return 0; 2419 2420 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf))) 2421 return -EFAULT; 2422 2423 p->arg.vec_len -= n; 2424 p->vec_out += n; 2425 2426 p->vec_buf_index = 0; 2427 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len); 2428 p->vec_buf->start = p->vec_buf->end = 0; 2429 2430 return n; 2431 } 2432 2433 static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg) 2434 { 2435 struct pagemap_scan_private p = {0}; 2436 unsigned long walk_start; 2437 size_t n_ranges_out = 0; 2438 int ret; 2439 2440 ret = pagemap_scan_get_args(&p.arg, uarg); 2441 if (ret) 2442 return ret; 2443 2444 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask | 2445 p.arg.return_mask; 2446 ret = pagemap_scan_init_bounce_buffer(&p); 2447 if (ret) 2448 return ret; 2449 2450 for (walk_start = p.arg.start; walk_start < p.arg.end; 2451 walk_start = p.arg.walk_end) { 2452 struct mmu_notifier_range range; 2453 long n_out; 2454 2455 if (fatal_signal_pending(current)) { 2456 ret = -EINTR; 2457 break; 2458 } 2459 2460 ret = mmap_read_lock_killable(mm); 2461 if (ret) 2462 break; 2463 2464 /* Protection change for the range is going to happen. */ 2465 if (p.arg.flags & PM_SCAN_WP_MATCHING) { 2466 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, 2467 mm, walk_start, p.arg.end); 2468 mmu_notifier_invalidate_range_start(&range); 2469 } 2470 2471 ret = walk_page_range(mm, walk_start, p.arg.end, 2472 &pagemap_scan_ops, &p); 2473 2474 if (p.arg.flags & PM_SCAN_WP_MATCHING) 2475 mmu_notifier_invalidate_range_end(&range); 2476 2477 mmap_read_unlock(mm); 2478 2479 n_out = pagemap_scan_flush_buffer(&p); 2480 if (n_out < 0) 2481 ret = n_out; 2482 else 2483 n_ranges_out += n_out; 2484 2485 if (ret != -ENOSPC) 2486 break; 2487 2488 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages) 2489 break; 2490 } 2491 2492 /* ENOSPC signifies early stop (buffer full) from the walk. */ 2493 if (!ret || ret == -ENOSPC) 2494 ret = n_ranges_out; 2495 2496 /* The walk_end isn't set when ret is zero */ 2497 if (!p.arg.walk_end) 2498 p.arg.walk_end = p.arg.end; 2499 if (pagemap_scan_writeback_args(&p.arg, uarg)) 2500 ret = -EFAULT; 2501 2502 kfree(p.vec_buf); 2503 return ret; 2504 } 2505 2506 static long do_pagemap_cmd(struct file *file, unsigned int cmd, 2507 unsigned long arg) 2508 { 2509 struct mm_struct *mm = file->private_data; 2510 2511 switch (cmd) { 2512 case PAGEMAP_SCAN: 2513 return do_pagemap_scan(mm, arg); 2514 2515 default: 2516 return -EINVAL; 2517 } 2518 } 2519 2520 const struct file_operations proc_pagemap_operations = { 2521 .llseek = mem_lseek, /* borrow this */ 2522 .read = pagemap_read, 2523 .open = pagemap_open, 2524 .release = pagemap_release, 2525 .unlocked_ioctl = do_pagemap_cmd, 2526 .compat_ioctl = do_pagemap_cmd, 2527 }; 2528 #endif /* CONFIG_PROC_PAGE_MONITOR */ 2529 2530 #ifdef CONFIG_NUMA 2531 2532 struct numa_maps { 2533 unsigned long pages; 2534 unsigned long anon; 2535 unsigned long active; 2536 unsigned long writeback; 2537 unsigned long mapcount_max; 2538 unsigned long dirty; 2539 unsigned long swapcache; 2540 unsigned long node[MAX_NUMNODES]; 2541 }; 2542 2543 struct numa_maps_private { 2544 struct proc_maps_private proc_maps; 2545 struct numa_maps md; 2546 }; 2547 2548 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 2549 unsigned long nr_pages) 2550 { 2551 int count = page_mapcount(page); 2552 2553 md->pages += nr_pages; 2554 if (pte_dirty || PageDirty(page)) 2555 md->dirty += nr_pages; 2556 2557 if (PageSwapCache(page)) 2558 md->swapcache += nr_pages; 2559 2560 if (PageActive(page) || PageUnevictable(page)) 2561 md->active += nr_pages; 2562 2563 if (PageWriteback(page)) 2564 md->writeback += nr_pages; 2565 2566 if (PageAnon(page)) 2567 md->anon += nr_pages; 2568 2569 if (count > md->mapcount_max) 2570 md->mapcount_max = count; 2571 2572 md->node[page_to_nid(page)] += nr_pages; 2573 } 2574 2575 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 2576 unsigned long addr) 2577 { 2578 struct page *page; 2579 int nid; 2580 2581 if (!pte_present(pte)) 2582 return NULL; 2583 2584 page = vm_normal_page(vma, addr, pte); 2585 if (!page || is_zone_device_page(page)) 2586 return NULL; 2587 2588 if (PageReserved(page)) 2589 return NULL; 2590 2591 nid = page_to_nid(page); 2592 if (!node_isset(nid, node_states[N_MEMORY])) 2593 return NULL; 2594 2595 return page; 2596 } 2597 2598 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2599 static struct page *can_gather_numa_stats_pmd(pmd_t pmd, 2600 struct vm_area_struct *vma, 2601 unsigned long addr) 2602 { 2603 struct page *page; 2604 int nid; 2605 2606 if (!pmd_present(pmd)) 2607 return NULL; 2608 2609 page = vm_normal_page_pmd(vma, addr, pmd); 2610 if (!page) 2611 return NULL; 2612 2613 if (PageReserved(page)) 2614 return NULL; 2615 2616 nid = page_to_nid(page); 2617 if (!node_isset(nid, node_states[N_MEMORY])) 2618 return NULL; 2619 2620 return page; 2621 } 2622 #endif 2623 2624 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 2625 unsigned long end, struct mm_walk *walk) 2626 { 2627 struct numa_maps *md = walk->private; 2628 struct vm_area_struct *vma = walk->vma; 2629 spinlock_t *ptl; 2630 pte_t *orig_pte; 2631 pte_t *pte; 2632 2633 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2634 ptl = pmd_trans_huge_lock(pmd, vma); 2635 if (ptl) { 2636 struct page *page; 2637 2638 page = can_gather_numa_stats_pmd(*pmd, vma, addr); 2639 if (page) 2640 gather_stats(page, md, pmd_dirty(*pmd), 2641 HPAGE_PMD_SIZE/PAGE_SIZE); 2642 spin_unlock(ptl); 2643 return 0; 2644 } 2645 #endif 2646 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 2647 if (!pte) { 2648 walk->action = ACTION_AGAIN; 2649 return 0; 2650 } 2651 do { 2652 pte_t ptent = ptep_get(pte); 2653 struct page *page = can_gather_numa_stats(ptent, vma, addr); 2654 if (!page) 2655 continue; 2656 gather_stats(page, md, pte_dirty(ptent), 1); 2657 2658 } while (pte++, addr += PAGE_SIZE, addr != end); 2659 pte_unmap_unlock(orig_pte, ptl); 2660 cond_resched(); 2661 return 0; 2662 } 2663 #ifdef CONFIG_HUGETLB_PAGE 2664 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2665 unsigned long addr, unsigned long end, struct mm_walk *walk) 2666 { 2667 pte_t huge_pte = huge_ptep_get(pte); 2668 struct numa_maps *md; 2669 struct page *page; 2670 2671 if (!pte_present(huge_pte)) 2672 return 0; 2673 2674 page = pte_page(huge_pte); 2675 2676 md = walk->private; 2677 gather_stats(page, md, pte_dirty(huge_pte), 1); 2678 return 0; 2679 } 2680 2681 #else 2682 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2683 unsigned long addr, unsigned long end, struct mm_walk *walk) 2684 { 2685 return 0; 2686 } 2687 #endif 2688 2689 static const struct mm_walk_ops show_numa_ops = { 2690 .hugetlb_entry = gather_hugetlb_stats, 2691 .pmd_entry = gather_pte_stats, 2692 .walk_lock = PGWALK_RDLOCK, 2693 }; 2694 2695 /* 2696 * Display pages allocated per node and memory policy via /proc. 2697 */ 2698 static int show_numa_map(struct seq_file *m, void *v) 2699 { 2700 struct numa_maps_private *numa_priv = m->private; 2701 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 2702 struct vm_area_struct *vma = v; 2703 struct numa_maps *md = &numa_priv->md; 2704 struct file *file = vma->vm_file; 2705 struct mm_struct *mm = vma->vm_mm; 2706 char buffer[64]; 2707 struct mempolicy *pol; 2708 pgoff_t ilx; 2709 int nid; 2710 2711 if (!mm) 2712 return 0; 2713 2714 /* Ensure we start with an empty set of numa_maps statistics. */ 2715 memset(md, 0, sizeof(*md)); 2716 2717 pol = __get_vma_policy(vma, vma->vm_start, &ilx); 2718 if (pol) { 2719 mpol_to_str(buffer, sizeof(buffer), pol); 2720 mpol_cond_put(pol); 2721 } else { 2722 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); 2723 } 2724 2725 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 2726 2727 if (file) { 2728 seq_puts(m, " file="); 2729 seq_path(m, file_user_path(file), "\n\t= "); 2730 } else if (vma_is_initial_heap(vma)) { 2731 seq_puts(m, " heap"); 2732 } else if (vma_is_initial_stack(vma)) { 2733 seq_puts(m, " stack"); 2734 } 2735 2736 if (is_vm_hugetlb_page(vma)) 2737 seq_puts(m, " huge"); 2738 2739 /* mmap_lock is held by m_start */ 2740 walk_page_vma(vma, &show_numa_ops, md); 2741 2742 if (!md->pages) 2743 goto out; 2744 2745 if (md->anon) 2746 seq_printf(m, " anon=%lu", md->anon); 2747 2748 if (md->dirty) 2749 seq_printf(m, " dirty=%lu", md->dirty); 2750 2751 if (md->pages != md->anon && md->pages != md->dirty) 2752 seq_printf(m, " mapped=%lu", md->pages); 2753 2754 if (md->mapcount_max > 1) 2755 seq_printf(m, " mapmax=%lu", md->mapcount_max); 2756 2757 if (md->swapcache) 2758 seq_printf(m, " swapcache=%lu", md->swapcache); 2759 2760 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 2761 seq_printf(m, " active=%lu", md->active); 2762 2763 if (md->writeback) 2764 seq_printf(m, " writeback=%lu", md->writeback); 2765 2766 for_each_node_state(nid, N_MEMORY) 2767 if (md->node[nid]) 2768 seq_printf(m, " N%d=%lu", nid, md->node[nid]); 2769 2770 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); 2771 out: 2772 seq_putc(m, '\n'); 2773 return 0; 2774 } 2775 2776 static const struct seq_operations proc_pid_numa_maps_op = { 2777 .start = m_start, 2778 .next = m_next, 2779 .stop = m_stop, 2780 .show = show_numa_map, 2781 }; 2782 2783 static int pid_numa_maps_open(struct inode *inode, struct file *file) 2784 { 2785 return proc_maps_open(inode, file, &proc_pid_numa_maps_op, 2786 sizeof(struct numa_maps_private)); 2787 } 2788 2789 const struct file_operations proc_pid_numa_maps_operations = { 2790 .open = pid_numa_maps_open, 2791 .read = seq_read, 2792 .llseek = seq_lseek, 2793 .release = proc_map_release, 2794 }; 2795 2796 #endif /* CONFIG_NUMA */ 2797