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(pagemap_entry_t *pme, struct pagemapread *pm) 1356 { 1357 pm->buffer[pm->pos++] = *pme; 1358 if (pm->pos >= pm->len) 1359 return PM_END_OF_BUFFER; 1360 return 0; 1361 } 1362 1363 static int pagemap_pte_hole(unsigned long start, unsigned long end, 1364 __always_unused int depth, struct mm_walk *walk) 1365 { 1366 struct pagemapread *pm = walk->private; 1367 unsigned long addr = start; 1368 int err = 0; 1369 1370 while (addr < end) { 1371 struct vm_area_struct *vma = find_vma(walk->mm, addr); 1372 pagemap_entry_t pme = make_pme(0, 0); 1373 /* End of address space hole, which we mark as non-present. */ 1374 unsigned long hole_end; 1375 1376 if (vma) 1377 hole_end = min(end, vma->vm_start); 1378 else 1379 hole_end = end; 1380 1381 for (; addr < hole_end; addr += PAGE_SIZE) { 1382 err = add_to_pagemap(&pme, pm); 1383 if (err) 1384 goto out; 1385 } 1386 1387 if (!vma) 1388 break; 1389 1390 /* Addresses in the VMA. */ 1391 if (vma->vm_flags & VM_SOFTDIRTY) 1392 pme = make_pme(0, PM_SOFT_DIRTY); 1393 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { 1394 err = add_to_pagemap(&pme, pm); 1395 if (err) 1396 goto out; 1397 } 1398 } 1399 out: 1400 return err; 1401 } 1402 1403 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 1404 struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1405 { 1406 u64 frame = 0, flags = 0; 1407 struct page *page = NULL; 1408 bool migration = false; 1409 1410 if (pte_present(pte)) { 1411 if (pm->show_pfn) 1412 frame = pte_pfn(pte); 1413 flags |= PM_PRESENT; 1414 page = vm_normal_page(vma, addr, pte); 1415 if (pte_soft_dirty(pte)) 1416 flags |= PM_SOFT_DIRTY; 1417 if (pte_uffd_wp(pte)) 1418 flags |= PM_UFFD_WP; 1419 } else if (is_swap_pte(pte)) { 1420 swp_entry_t entry; 1421 if (pte_swp_soft_dirty(pte)) 1422 flags |= PM_SOFT_DIRTY; 1423 if (pte_swp_uffd_wp(pte)) 1424 flags |= PM_UFFD_WP; 1425 entry = pte_to_swp_entry(pte); 1426 if (pm->show_pfn) { 1427 pgoff_t offset; 1428 /* 1429 * For PFN swap offsets, keeping the offset field 1430 * to be PFN only to be compatible with old smaps. 1431 */ 1432 if (is_pfn_swap_entry(entry)) 1433 offset = swp_offset_pfn(entry); 1434 else 1435 offset = swp_offset(entry); 1436 frame = swp_type(entry) | 1437 (offset << MAX_SWAPFILES_SHIFT); 1438 } 1439 flags |= PM_SWAP; 1440 migration = is_migration_entry(entry); 1441 if (is_pfn_swap_entry(entry)) 1442 page = pfn_swap_entry_to_page(entry); 1443 if (pte_marker_entry_uffd_wp(entry)) 1444 flags |= PM_UFFD_WP; 1445 } 1446 1447 if (page && !PageAnon(page)) 1448 flags |= PM_FILE; 1449 if (page && !migration && page_mapcount(page) == 1) 1450 flags |= PM_MMAP_EXCLUSIVE; 1451 if (vma->vm_flags & VM_SOFTDIRTY) 1452 flags |= PM_SOFT_DIRTY; 1453 1454 return make_pme(frame, flags); 1455 } 1456 1457 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, 1458 struct mm_walk *walk) 1459 { 1460 struct vm_area_struct *vma = walk->vma; 1461 struct pagemapread *pm = walk->private; 1462 spinlock_t *ptl; 1463 pte_t *pte, *orig_pte; 1464 int err = 0; 1465 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1466 bool migration = false; 1467 1468 ptl = pmd_trans_huge_lock(pmdp, vma); 1469 if (ptl) { 1470 u64 flags = 0, frame = 0; 1471 pmd_t pmd = *pmdp; 1472 struct page *page = NULL; 1473 1474 if (vma->vm_flags & VM_SOFTDIRTY) 1475 flags |= PM_SOFT_DIRTY; 1476 1477 if (pmd_present(pmd)) { 1478 page = pmd_page(pmd); 1479 1480 flags |= PM_PRESENT; 1481 if (pmd_soft_dirty(pmd)) 1482 flags |= PM_SOFT_DIRTY; 1483 if (pmd_uffd_wp(pmd)) 1484 flags |= PM_UFFD_WP; 1485 if (pm->show_pfn) 1486 frame = pmd_pfn(pmd) + 1487 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1488 } 1489 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1490 else if (is_swap_pmd(pmd)) { 1491 swp_entry_t entry = pmd_to_swp_entry(pmd); 1492 unsigned long offset; 1493 1494 if (pm->show_pfn) { 1495 if (is_pfn_swap_entry(entry)) 1496 offset = swp_offset_pfn(entry); 1497 else 1498 offset = swp_offset(entry); 1499 offset = offset + 1500 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1501 frame = swp_type(entry) | 1502 (offset << MAX_SWAPFILES_SHIFT); 1503 } 1504 flags |= PM_SWAP; 1505 if (pmd_swp_soft_dirty(pmd)) 1506 flags |= PM_SOFT_DIRTY; 1507 if (pmd_swp_uffd_wp(pmd)) 1508 flags |= PM_UFFD_WP; 1509 VM_BUG_ON(!is_pmd_migration_entry(pmd)); 1510 migration = is_migration_entry(entry); 1511 page = pfn_swap_entry_to_page(entry); 1512 } 1513 #endif 1514 1515 if (page && !migration && page_mapcount(page) == 1) 1516 flags |= PM_MMAP_EXCLUSIVE; 1517 1518 for (; addr != end; addr += PAGE_SIZE) { 1519 pagemap_entry_t pme = make_pme(frame, flags); 1520 1521 err = add_to_pagemap(&pme, pm); 1522 if (err) 1523 break; 1524 if (pm->show_pfn) { 1525 if (flags & PM_PRESENT) 1526 frame++; 1527 else if (flags & PM_SWAP) 1528 frame += (1 << MAX_SWAPFILES_SHIFT); 1529 } 1530 } 1531 spin_unlock(ptl); 1532 return err; 1533 } 1534 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1535 1536 /* 1537 * We can assume that @vma always points to a valid one and @end never 1538 * goes beyond vma->vm_end. 1539 */ 1540 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); 1541 if (!pte) { 1542 walk->action = ACTION_AGAIN; 1543 return err; 1544 } 1545 for (; addr < end; pte++, addr += PAGE_SIZE) { 1546 pagemap_entry_t pme; 1547 1548 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte)); 1549 err = add_to_pagemap(&pme, pm); 1550 if (err) 1551 break; 1552 } 1553 pte_unmap_unlock(orig_pte, ptl); 1554 1555 cond_resched(); 1556 1557 return err; 1558 } 1559 1560 #ifdef CONFIG_HUGETLB_PAGE 1561 /* This function walks within one hugetlb entry in the single call */ 1562 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 1563 unsigned long addr, unsigned long end, 1564 struct mm_walk *walk) 1565 { 1566 struct pagemapread *pm = walk->private; 1567 struct vm_area_struct *vma = walk->vma; 1568 u64 flags = 0, frame = 0; 1569 int err = 0; 1570 pte_t pte; 1571 1572 if (vma->vm_flags & VM_SOFTDIRTY) 1573 flags |= PM_SOFT_DIRTY; 1574 1575 pte = huge_ptep_get(ptep); 1576 if (pte_present(pte)) { 1577 struct page *page = pte_page(pte); 1578 1579 if (!PageAnon(page)) 1580 flags |= PM_FILE; 1581 1582 if (page_mapcount(page) == 1) 1583 flags |= PM_MMAP_EXCLUSIVE; 1584 1585 if (huge_pte_uffd_wp(pte)) 1586 flags |= PM_UFFD_WP; 1587 1588 flags |= PM_PRESENT; 1589 if (pm->show_pfn) 1590 frame = pte_pfn(pte) + 1591 ((addr & ~hmask) >> PAGE_SHIFT); 1592 } else if (pte_swp_uffd_wp_any(pte)) { 1593 flags |= PM_UFFD_WP; 1594 } 1595 1596 for (; addr != end; addr += PAGE_SIZE) { 1597 pagemap_entry_t pme = make_pme(frame, flags); 1598 1599 err = add_to_pagemap(&pme, pm); 1600 if (err) 1601 return err; 1602 if (pm->show_pfn && (flags & PM_PRESENT)) 1603 frame++; 1604 } 1605 1606 cond_resched(); 1607 1608 return err; 1609 } 1610 #else 1611 #define pagemap_hugetlb_range NULL 1612 #endif /* HUGETLB_PAGE */ 1613 1614 static const struct mm_walk_ops pagemap_ops = { 1615 .pmd_entry = pagemap_pmd_range, 1616 .pte_hole = pagemap_pte_hole, 1617 .hugetlb_entry = pagemap_hugetlb_range, 1618 .walk_lock = PGWALK_RDLOCK, 1619 }; 1620 1621 /* 1622 * /proc/pid/pagemap - an array mapping virtual pages to pfns 1623 * 1624 * For each page in the address space, this file contains one 64-bit entry 1625 * consisting of the following: 1626 * 1627 * Bits 0-54 page frame number (PFN) if present 1628 * Bits 0-4 swap type if swapped 1629 * Bits 5-54 swap offset if swapped 1630 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) 1631 * Bit 56 page exclusively mapped 1632 * Bit 57 pte is uffd-wp write-protected 1633 * Bits 58-60 zero 1634 * Bit 61 page is file-page or shared-anon 1635 * Bit 62 page swapped 1636 * Bit 63 page present 1637 * 1638 * If the page is not present but in swap, then the PFN contains an 1639 * encoding of the swap file number and the page's offset into the 1640 * swap. Unmapped pages return a null PFN. This allows determining 1641 * precisely which pages are mapped (or in swap) and comparing mapped 1642 * pages between processes. 1643 * 1644 * Efficient users of this interface will use /proc/pid/maps to 1645 * determine which areas of memory are actually mapped and llseek to 1646 * skip over unmapped regions. 1647 */ 1648 static ssize_t pagemap_read(struct file *file, char __user *buf, 1649 size_t count, loff_t *ppos) 1650 { 1651 struct mm_struct *mm = file->private_data; 1652 struct pagemapread pm; 1653 unsigned long src; 1654 unsigned long svpfn; 1655 unsigned long start_vaddr; 1656 unsigned long end_vaddr; 1657 int ret = 0, copied = 0; 1658 1659 if (!mm || !mmget_not_zero(mm)) 1660 goto out; 1661 1662 ret = -EINVAL; 1663 /* file position must be aligned */ 1664 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 1665 goto out_mm; 1666 1667 ret = 0; 1668 if (!count) 1669 goto out_mm; 1670 1671 /* do not disclose physical addresses: attack vector */ 1672 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); 1673 1674 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 1675 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); 1676 ret = -ENOMEM; 1677 if (!pm.buffer) 1678 goto out_mm; 1679 1680 src = *ppos; 1681 svpfn = src / PM_ENTRY_BYTES; 1682 end_vaddr = mm->task_size; 1683 1684 /* watch out for wraparound */ 1685 start_vaddr = end_vaddr; 1686 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) { 1687 unsigned long end; 1688 1689 ret = mmap_read_lock_killable(mm); 1690 if (ret) 1691 goto out_free; 1692 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT); 1693 mmap_read_unlock(mm); 1694 1695 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT); 1696 if (end >= start_vaddr && end < mm->task_size) 1697 end_vaddr = end; 1698 } 1699 1700 /* Ensure the address is inside the task */ 1701 if (start_vaddr > mm->task_size) 1702 start_vaddr = end_vaddr; 1703 1704 ret = 0; 1705 while (count && (start_vaddr < end_vaddr)) { 1706 int len; 1707 unsigned long end; 1708 1709 pm.pos = 0; 1710 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 1711 /* overflow ? */ 1712 if (end < start_vaddr || end > end_vaddr) 1713 end = end_vaddr; 1714 ret = mmap_read_lock_killable(mm); 1715 if (ret) 1716 goto out_free; 1717 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm); 1718 mmap_read_unlock(mm); 1719 start_vaddr = end; 1720 1721 len = min(count, PM_ENTRY_BYTES * pm.pos); 1722 if (copy_to_user(buf, pm.buffer, len)) { 1723 ret = -EFAULT; 1724 goto out_free; 1725 } 1726 copied += len; 1727 buf += len; 1728 count -= len; 1729 } 1730 *ppos += copied; 1731 if (!ret || ret == PM_END_OF_BUFFER) 1732 ret = copied; 1733 1734 out_free: 1735 kfree(pm.buffer); 1736 out_mm: 1737 mmput(mm); 1738 out: 1739 return ret; 1740 } 1741 1742 static int pagemap_open(struct inode *inode, struct file *file) 1743 { 1744 struct mm_struct *mm; 1745 1746 mm = proc_mem_open(inode, PTRACE_MODE_READ); 1747 if (IS_ERR(mm)) 1748 return PTR_ERR(mm); 1749 file->private_data = mm; 1750 return 0; 1751 } 1752 1753 static int pagemap_release(struct inode *inode, struct file *file) 1754 { 1755 struct mm_struct *mm = file->private_data; 1756 1757 if (mm) 1758 mmdrop(mm); 1759 return 0; 1760 } 1761 1762 #define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \ 1763 PAGE_IS_FILE | PAGE_IS_PRESENT | \ 1764 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \ 1765 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY) 1766 #define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC) 1767 1768 struct pagemap_scan_private { 1769 struct pm_scan_arg arg; 1770 unsigned long masks_of_interest, cur_vma_category; 1771 struct page_region *vec_buf; 1772 unsigned long vec_buf_len, vec_buf_index, found_pages; 1773 struct page_region __user *vec_out; 1774 }; 1775 1776 static unsigned long pagemap_page_category(struct pagemap_scan_private *p, 1777 struct vm_area_struct *vma, 1778 unsigned long addr, pte_t pte) 1779 { 1780 unsigned long categories = 0; 1781 1782 if (pte_present(pte)) { 1783 struct page *page; 1784 1785 categories |= PAGE_IS_PRESENT; 1786 if (!pte_uffd_wp(pte)) 1787 categories |= PAGE_IS_WRITTEN; 1788 1789 if (p->masks_of_interest & PAGE_IS_FILE) { 1790 page = vm_normal_page(vma, addr, pte); 1791 if (page && !PageAnon(page)) 1792 categories |= PAGE_IS_FILE; 1793 } 1794 1795 if (is_zero_pfn(pte_pfn(pte))) 1796 categories |= PAGE_IS_PFNZERO; 1797 if (pte_soft_dirty(pte)) 1798 categories |= PAGE_IS_SOFT_DIRTY; 1799 } else if (is_swap_pte(pte)) { 1800 swp_entry_t swp; 1801 1802 categories |= PAGE_IS_SWAPPED; 1803 if (!pte_swp_uffd_wp_any(pte)) 1804 categories |= PAGE_IS_WRITTEN; 1805 1806 if (p->masks_of_interest & PAGE_IS_FILE) { 1807 swp = pte_to_swp_entry(pte); 1808 if (is_pfn_swap_entry(swp) && 1809 !folio_test_anon(pfn_swap_entry_folio(swp))) 1810 categories |= PAGE_IS_FILE; 1811 } 1812 if (pte_swp_soft_dirty(pte)) 1813 categories |= PAGE_IS_SOFT_DIRTY; 1814 } 1815 1816 return categories; 1817 } 1818 1819 static void make_uffd_wp_pte(struct vm_area_struct *vma, 1820 unsigned long addr, pte_t *pte) 1821 { 1822 pte_t ptent = ptep_get(pte); 1823 1824 if (pte_present(ptent)) { 1825 pte_t old_pte; 1826 1827 old_pte = ptep_modify_prot_start(vma, addr, pte); 1828 ptent = pte_mkuffd_wp(ptent); 1829 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 1830 } else if (is_swap_pte(ptent)) { 1831 ptent = pte_swp_mkuffd_wp(ptent); 1832 set_pte_at(vma->vm_mm, addr, pte, ptent); 1833 } else { 1834 set_pte_at(vma->vm_mm, addr, pte, 1835 make_pte_marker(PTE_MARKER_UFFD_WP)); 1836 } 1837 } 1838 1839 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1840 static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, 1841 struct vm_area_struct *vma, 1842 unsigned long addr, pmd_t pmd) 1843 { 1844 unsigned long categories = PAGE_IS_HUGE; 1845 1846 if (pmd_present(pmd)) { 1847 struct page *page; 1848 1849 categories |= PAGE_IS_PRESENT; 1850 if (!pmd_uffd_wp(pmd)) 1851 categories |= PAGE_IS_WRITTEN; 1852 1853 if (p->masks_of_interest & PAGE_IS_FILE) { 1854 page = vm_normal_page_pmd(vma, addr, pmd); 1855 if (page && !PageAnon(page)) 1856 categories |= PAGE_IS_FILE; 1857 } 1858 1859 if (is_zero_pfn(pmd_pfn(pmd))) 1860 categories |= PAGE_IS_PFNZERO; 1861 if (pmd_soft_dirty(pmd)) 1862 categories |= PAGE_IS_SOFT_DIRTY; 1863 } else if (is_swap_pmd(pmd)) { 1864 swp_entry_t swp; 1865 1866 categories |= PAGE_IS_SWAPPED; 1867 if (!pmd_swp_uffd_wp(pmd)) 1868 categories |= PAGE_IS_WRITTEN; 1869 if (pmd_swp_soft_dirty(pmd)) 1870 categories |= PAGE_IS_SOFT_DIRTY; 1871 1872 if (p->masks_of_interest & PAGE_IS_FILE) { 1873 swp = pmd_to_swp_entry(pmd); 1874 if (is_pfn_swap_entry(swp) && 1875 !folio_test_anon(pfn_swap_entry_folio(swp))) 1876 categories |= PAGE_IS_FILE; 1877 } 1878 } 1879 1880 return categories; 1881 } 1882 1883 static void make_uffd_wp_pmd(struct vm_area_struct *vma, 1884 unsigned long addr, pmd_t *pmdp) 1885 { 1886 pmd_t old, pmd = *pmdp; 1887 1888 if (pmd_present(pmd)) { 1889 old = pmdp_invalidate_ad(vma, addr, pmdp); 1890 pmd = pmd_mkuffd_wp(old); 1891 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1892 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 1893 pmd = pmd_swp_mkuffd_wp(pmd); 1894 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1895 } 1896 } 1897 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1898 1899 #ifdef CONFIG_HUGETLB_PAGE 1900 static unsigned long pagemap_hugetlb_category(pte_t pte) 1901 { 1902 unsigned long categories = PAGE_IS_HUGE; 1903 1904 /* 1905 * According to pagemap_hugetlb_range(), file-backed HugeTLB 1906 * page cannot be swapped. So PAGE_IS_FILE is not checked for 1907 * swapped pages. 1908 */ 1909 if (pte_present(pte)) { 1910 categories |= PAGE_IS_PRESENT; 1911 if (!huge_pte_uffd_wp(pte)) 1912 categories |= PAGE_IS_WRITTEN; 1913 if (!PageAnon(pte_page(pte))) 1914 categories |= PAGE_IS_FILE; 1915 if (is_zero_pfn(pte_pfn(pte))) 1916 categories |= PAGE_IS_PFNZERO; 1917 if (pte_soft_dirty(pte)) 1918 categories |= PAGE_IS_SOFT_DIRTY; 1919 } else if (is_swap_pte(pte)) { 1920 categories |= PAGE_IS_SWAPPED; 1921 if (!pte_swp_uffd_wp_any(pte)) 1922 categories |= PAGE_IS_WRITTEN; 1923 if (pte_swp_soft_dirty(pte)) 1924 categories |= PAGE_IS_SOFT_DIRTY; 1925 } 1926 1927 return categories; 1928 } 1929 1930 static void make_uffd_wp_huge_pte(struct vm_area_struct *vma, 1931 unsigned long addr, pte_t *ptep, 1932 pte_t ptent) 1933 { 1934 unsigned long psize; 1935 1936 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) 1937 return; 1938 1939 psize = huge_page_size(hstate_vma(vma)); 1940 1941 if (is_hugetlb_entry_migration(ptent)) 1942 set_huge_pte_at(vma->vm_mm, addr, ptep, 1943 pte_swp_mkuffd_wp(ptent), psize); 1944 else if (!huge_pte_none(ptent)) 1945 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, 1946 huge_pte_mkuffd_wp(ptent)); 1947 else 1948 set_huge_pte_at(vma->vm_mm, addr, ptep, 1949 make_pte_marker(PTE_MARKER_UFFD_WP), psize); 1950 } 1951 #endif /* CONFIG_HUGETLB_PAGE */ 1952 1953 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) 1954 static void pagemap_scan_backout_range(struct pagemap_scan_private *p, 1955 unsigned long addr, unsigned long end) 1956 { 1957 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 1958 1959 if (cur_buf->start != addr) 1960 cur_buf->end = addr; 1961 else 1962 cur_buf->start = cur_buf->end = 0; 1963 1964 p->found_pages -= (end - addr) / PAGE_SIZE; 1965 } 1966 #endif 1967 1968 static bool pagemap_scan_is_interesting_page(unsigned long categories, 1969 const struct pagemap_scan_private *p) 1970 { 1971 categories ^= p->arg.category_inverted; 1972 if ((categories & p->arg.category_mask) != p->arg.category_mask) 1973 return false; 1974 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask)) 1975 return false; 1976 1977 return true; 1978 } 1979 1980 static bool pagemap_scan_is_interesting_vma(unsigned long categories, 1981 const struct pagemap_scan_private *p) 1982 { 1983 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED; 1984 1985 categories ^= p->arg.category_inverted; 1986 if ((categories & required) != required) 1987 return false; 1988 1989 return true; 1990 } 1991 1992 static int pagemap_scan_test_walk(unsigned long start, unsigned long end, 1993 struct mm_walk *walk) 1994 { 1995 struct pagemap_scan_private *p = walk->private; 1996 struct vm_area_struct *vma = walk->vma; 1997 unsigned long vma_category = 0; 1998 bool wp_allowed = userfaultfd_wp_async(vma) && 1999 userfaultfd_wp_use_markers(vma); 2000 2001 if (!wp_allowed) { 2002 /* User requested explicit failure over wp-async capability */ 2003 if (p->arg.flags & PM_SCAN_CHECK_WPASYNC) 2004 return -EPERM; 2005 /* 2006 * User requires wr-protect, and allows silently skipping 2007 * unsupported vmas. 2008 */ 2009 if (p->arg.flags & PM_SCAN_WP_MATCHING) 2010 return 1; 2011 /* 2012 * Then the request doesn't involve wr-protects at all, 2013 * fall through to the rest checks, and allow vma walk. 2014 */ 2015 } 2016 2017 if (vma->vm_flags & VM_PFNMAP) 2018 return 1; 2019 2020 if (wp_allowed) 2021 vma_category |= PAGE_IS_WPALLOWED; 2022 2023 if (vma->vm_flags & VM_SOFTDIRTY) 2024 vma_category |= PAGE_IS_SOFT_DIRTY; 2025 2026 if (!pagemap_scan_is_interesting_vma(vma_category, p)) 2027 return 1; 2028 2029 p->cur_vma_category = vma_category; 2030 2031 return 0; 2032 } 2033 2034 static bool pagemap_scan_push_range(unsigned long categories, 2035 struct pagemap_scan_private *p, 2036 unsigned long addr, unsigned long end) 2037 { 2038 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2039 2040 /* 2041 * When there is no output buffer provided at all, the sentinel values 2042 * won't match here. There is no other way for `cur_buf->end` to be 2043 * non-zero other than it being non-empty. 2044 */ 2045 if (addr == cur_buf->end && categories == cur_buf->categories) { 2046 cur_buf->end = end; 2047 return true; 2048 } 2049 2050 if (cur_buf->end) { 2051 if (p->vec_buf_index >= p->vec_buf_len - 1) 2052 return false; 2053 2054 cur_buf = &p->vec_buf[++p->vec_buf_index]; 2055 } 2056 2057 cur_buf->start = addr; 2058 cur_buf->end = end; 2059 cur_buf->categories = categories; 2060 2061 return true; 2062 } 2063 2064 static int pagemap_scan_output(unsigned long categories, 2065 struct pagemap_scan_private *p, 2066 unsigned long addr, unsigned long *end) 2067 { 2068 unsigned long n_pages, total_pages; 2069 int ret = 0; 2070 2071 if (!p->vec_buf) 2072 return 0; 2073 2074 categories &= p->arg.return_mask; 2075 2076 n_pages = (*end - addr) / PAGE_SIZE; 2077 if (check_add_overflow(p->found_pages, n_pages, &total_pages) || 2078 total_pages > p->arg.max_pages) { 2079 size_t n_too_much = total_pages - p->arg.max_pages; 2080 *end -= n_too_much * PAGE_SIZE; 2081 n_pages -= n_too_much; 2082 ret = -ENOSPC; 2083 } 2084 2085 if (!pagemap_scan_push_range(categories, p, addr, *end)) { 2086 *end = addr; 2087 n_pages = 0; 2088 ret = -ENOSPC; 2089 } 2090 2091 p->found_pages += n_pages; 2092 if (ret) 2093 p->arg.walk_end = *end; 2094 2095 return ret; 2096 } 2097 2098 static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start, 2099 unsigned long end, struct mm_walk *walk) 2100 { 2101 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2102 struct pagemap_scan_private *p = walk->private; 2103 struct vm_area_struct *vma = walk->vma; 2104 unsigned long categories; 2105 spinlock_t *ptl; 2106 int ret = 0; 2107 2108 ptl = pmd_trans_huge_lock(pmd, vma); 2109 if (!ptl) 2110 return -ENOENT; 2111 2112 categories = p->cur_vma_category | 2113 pagemap_thp_category(p, vma, start, *pmd); 2114 2115 if (!pagemap_scan_is_interesting_page(categories, p)) 2116 goto out_unlock; 2117 2118 ret = pagemap_scan_output(categories, p, start, &end); 2119 if (start == end) 2120 goto out_unlock; 2121 2122 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2123 goto out_unlock; 2124 if (~categories & PAGE_IS_WRITTEN) 2125 goto out_unlock; 2126 2127 /* 2128 * Break huge page into small pages if the WP operation 2129 * needs to be performed on a portion of the huge page. 2130 */ 2131 if (end != start + HPAGE_SIZE) { 2132 spin_unlock(ptl); 2133 split_huge_pmd(vma, pmd, start); 2134 pagemap_scan_backout_range(p, start, end); 2135 /* Report as if there was no THP */ 2136 return -ENOENT; 2137 } 2138 2139 make_uffd_wp_pmd(vma, start, pmd); 2140 flush_tlb_range(vma, start, end); 2141 out_unlock: 2142 spin_unlock(ptl); 2143 return ret; 2144 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 2145 return -ENOENT; 2146 #endif 2147 } 2148 2149 static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, 2150 unsigned long end, struct mm_walk *walk) 2151 { 2152 struct pagemap_scan_private *p = walk->private; 2153 struct vm_area_struct *vma = walk->vma; 2154 unsigned long addr, flush_end = 0; 2155 pte_t *pte, *start_pte; 2156 spinlock_t *ptl; 2157 int ret; 2158 2159 arch_enter_lazy_mmu_mode(); 2160 2161 ret = pagemap_scan_thp_entry(pmd, start, end, walk); 2162 if (ret != -ENOENT) { 2163 arch_leave_lazy_mmu_mode(); 2164 return ret; 2165 } 2166 2167 ret = 0; 2168 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); 2169 if (!pte) { 2170 arch_leave_lazy_mmu_mode(); 2171 walk->action = ACTION_AGAIN; 2172 return 0; 2173 } 2174 2175 if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { 2176 /* Fast path for performing exclusive WP */ 2177 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2178 if (pte_uffd_wp(ptep_get(pte))) 2179 continue; 2180 make_uffd_wp_pte(vma, addr, pte); 2181 if (!flush_end) 2182 start = addr; 2183 flush_end = addr + PAGE_SIZE; 2184 } 2185 goto flush_and_return; 2186 } 2187 2188 if (!p->arg.category_anyof_mask && !p->arg.category_inverted && 2189 p->arg.category_mask == PAGE_IS_WRITTEN && 2190 p->arg.return_mask == PAGE_IS_WRITTEN) { 2191 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) { 2192 unsigned long next = addr + PAGE_SIZE; 2193 2194 if (pte_uffd_wp(ptep_get(pte))) 2195 continue; 2196 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN, 2197 p, addr, &next); 2198 if (next == addr) 2199 break; 2200 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2201 continue; 2202 make_uffd_wp_pte(vma, addr, pte); 2203 if (!flush_end) 2204 start = addr; 2205 flush_end = next; 2206 } 2207 goto flush_and_return; 2208 } 2209 2210 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2211 unsigned long categories = p->cur_vma_category | 2212 pagemap_page_category(p, vma, addr, ptep_get(pte)); 2213 unsigned long next = addr + PAGE_SIZE; 2214 2215 if (!pagemap_scan_is_interesting_page(categories, p)) 2216 continue; 2217 2218 ret = pagemap_scan_output(categories, p, addr, &next); 2219 if (next == addr) 2220 break; 2221 2222 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2223 continue; 2224 if (~categories & PAGE_IS_WRITTEN) 2225 continue; 2226 2227 make_uffd_wp_pte(vma, addr, pte); 2228 if (!flush_end) 2229 start = addr; 2230 flush_end = next; 2231 } 2232 2233 flush_and_return: 2234 if (flush_end) 2235 flush_tlb_range(vma, start, addr); 2236 2237 pte_unmap_unlock(start_pte, ptl); 2238 arch_leave_lazy_mmu_mode(); 2239 2240 cond_resched(); 2241 return ret; 2242 } 2243 2244 #ifdef CONFIG_HUGETLB_PAGE 2245 static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, 2246 unsigned long start, unsigned long end, 2247 struct mm_walk *walk) 2248 { 2249 struct pagemap_scan_private *p = walk->private; 2250 struct vm_area_struct *vma = walk->vma; 2251 unsigned long categories; 2252 spinlock_t *ptl; 2253 int ret = 0; 2254 pte_t pte; 2255 2256 if (~p->arg.flags & PM_SCAN_WP_MATCHING) { 2257 /* Go the short route when not write-protecting pages. */ 2258 2259 pte = huge_ptep_get(ptep); 2260 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2261 2262 if (!pagemap_scan_is_interesting_page(categories, p)) 2263 return 0; 2264 2265 return pagemap_scan_output(categories, p, start, &end); 2266 } 2267 2268 i_mmap_lock_write(vma->vm_file->f_mapping); 2269 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep); 2270 2271 pte = huge_ptep_get(ptep); 2272 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2273 2274 if (!pagemap_scan_is_interesting_page(categories, p)) 2275 goto out_unlock; 2276 2277 ret = pagemap_scan_output(categories, p, start, &end); 2278 if (start == end) 2279 goto out_unlock; 2280 2281 if (~categories & PAGE_IS_WRITTEN) 2282 goto out_unlock; 2283 2284 if (end != start + HPAGE_SIZE) { 2285 /* Partial HugeTLB page WP isn't possible. */ 2286 pagemap_scan_backout_range(p, start, end); 2287 p->arg.walk_end = start; 2288 ret = 0; 2289 goto out_unlock; 2290 } 2291 2292 make_uffd_wp_huge_pte(vma, start, ptep, pte); 2293 flush_hugetlb_tlb_range(vma, start, end); 2294 2295 out_unlock: 2296 spin_unlock(ptl); 2297 i_mmap_unlock_write(vma->vm_file->f_mapping); 2298 2299 return ret; 2300 } 2301 #else 2302 #define pagemap_scan_hugetlb_entry NULL 2303 #endif 2304 2305 static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, 2306 int depth, struct mm_walk *walk) 2307 { 2308 struct pagemap_scan_private *p = walk->private; 2309 struct vm_area_struct *vma = walk->vma; 2310 int ret, err; 2311 2312 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p)) 2313 return 0; 2314 2315 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end); 2316 if (addr == end) 2317 return ret; 2318 2319 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2320 return ret; 2321 2322 err = uffd_wp_range(vma, addr, end - addr, true); 2323 if (err < 0) 2324 ret = err; 2325 2326 return ret; 2327 } 2328 2329 static const struct mm_walk_ops pagemap_scan_ops = { 2330 .test_walk = pagemap_scan_test_walk, 2331 .pmd_entry = pagemap_scan_pmd_entry, 2332 .pte_hole = pagemap_scan_pte_hole, 2333 .hugetlb_entry = pagemap_scan_hugetlb_entry, 2334 }; 2335 2336 static int pagemap_scan_get_args(struct pm_scan_arg *arg, 2337 unsigned long uarg) 2338 { 2339 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg))) 2340 return -EFAULT; 2341 2342 if (arg->size != sizeof(struct pm_scan_arg)) 2343 return -EINVAL; 2344 2345 /* Validate requested features */ 2346 if (arg->flags & ~PM_SCAN_FLAGS) 2347 return -EINVAL; 2348 if ((arg->category_inverted | arg->category_mask | 2349 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) 2350 return -EINVAL; 2351 2352 arg->start = untagged_addr((unsigned long)arg->start); 2353 arg->end = untagged_addr((unsigned long)arg->end); 2354 arg->vec = untagged_addr((unsigned long)arg->vec); 2355 2356 /* Validate memory pointers */ 2357 if (!IS_ALIGNED(arg->start, PAGE_SIZE)) 2358 return -EINVAL; 2359 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start)) 2360 return -EFAULT; 2361 if (!arg->vec && arg->vec_len) 2362 return -EINVAL; 2363 if (arg->vec && !access_ok((void __user *)(long)arg->vec, 2364 arg->vec_len * sizeof(struct page_region))) 2365 return -EFAULT; 2366 2367 /* Fixup default values */ 2368 arg->end = ALIGN(arg->end, PAGE_SIZE); 2369 arg->walk_end = 0; 2370 if (!arg->max_pages) 2371 arg->max_pages = ULONG_MAX; 2372 2373 return 0; 2374 } 2375 2376 static int pagemap_scan_writeback_args(struct pm_scan_arg *arg, 2377 unsigned long uargl) 2378 { 2379 struct pm_scan_arg __user *uarg = (void __user *)uargl; 2380 2381 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end))) 2382 return -EFAULT; 2383 2384 return 0; 2385 } 2386 2387 static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p) 2388 { 2389 if (!p->arg.vec_len) 2390 return 0; 2391 2392 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT, 2393 p->arg.vec_len); 2394 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf), 2395 GFP_KERNEL); 2396 if (!p->vec_buf) 2397 return -ENOMEM; 2398 2399 p->vec_buf->start = p->vec_buf->end = 0; 2400 p->vec_out = (struct page_region __user *)(long)p->arg.vec; 2401 2402 return 0; 2403 } 2404 2405 static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p) 2406 { 2407 const struct page_region *buf = p->vec_buf; 2408 long n = p->vec_buf_index; 2409 2410 if (!p->vec_buf) 2411 return 0; 2412 2413 if (buf[n].end != buf[n].start) 2414 n++; 2415 2416 if (!n) 2417 return 0; 2418 2419 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf))) 2420 return -EFAULT; 2421 2422 p->arg.vec_len -= n; 2423 p->vec_out += n; 2424 2425 p->vec_buf_index = 0; 2426 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len); 2427 p->vec_buf->start = p->vec_buf->end = 0; 2428 2429 return n; 2430 } 2431 2432 static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg) 2433 { 2434 struct pagemap_scan_private p = {0}; 2435 unsigned long walk_start; 2436 size_t n_ranges_out = 0; 2437 int ret; 2438 2439 ret = pagemap_scan_get_args(&p.arg, uarg); 2440 if (ret) 2441 return ret; 2442 2443 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask | 2444 p.arg.return_mask; 2445 ret = pagemap_scan_init_bounce_buffer(&p); 2446 if (ret) 2447 return ret; 2448 2449 for (walk_start = p.arg.start; walk_start < p.arg.end; 2450 walk_start = p.arg.walk_end) { 2451 struct mmu_notifier_range range; 2452 long n_out; 2453 2454 if (fatal_signal_pending(current)) { 2455 ret = -EINTR; 2456 break; 2457 } 2458 2459 ret = mmap_read_lock_killable(mm); 2460 if (ret) 2461 break; 2462 2463 /* Protection change for the range is going to happen. */ 2464 if (p.arg.flags & PM_SCAN_WP_MATCHING) { 2465 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, 2466 mm, walk_start, p.arg.end); 2467 mmu_notifier_invalidate_range_start(&range); 2468 } 2469 2470 ret = walk_page_range(mm, walk_start, p.arg.end, 2471 &pagemap_scan_ops, &p); 2472 2473 if (p.arg.flags & PM_SCAN_WP_MATCHING) 2474 mmu_notifier_invalidate_range_end(&range); 2475 2476 mmap_read_unlock(mm); 2477 2478 n_out = pagemap_scan_flush_buffer(&p); 2479 if (n_out < 0) 2480 ret = n_out; 2481 else 2482 n_ranges_out += n_out; 2483 2484 if (ret != -ENOSPC) 2485 break; 2486 2487 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages) 2488 break; 2489 } 2490 2491 /* ENOSPC signifies early stop (buffer full) from the walk. */ 2492 if (!ret || ret == -ENOSPC) 2493 ret = n_ranges_out; 2494 2495 /* The walk_end isn't set when ret is zero */ 2496 if (!p.arg.walk_end) 2497 p.arg.walk_end = p.arg.end; 2498 if (pagemap_scan_writeback_args(&p.arg, uarg)) 2499 ret = -EFAULT; 2500 2501 kfree(p.vec_buf); 2502 return ret; 2503 } 2504 2505 static long do_pagemap_cmd(struct file *file, unsigned int cmd, 2506 unsigned long arg) 2507 { 2508 struct mm_struct *mm = file->private_data; 2509 2510 switch (cmd) { 2511 case PAGEMAP_SCAN: 2512 return do_pagemap_scan(mm, arg); 2513 2514 default: 2515 return -EINVAL; 2516 } 2517 } 2518 2519 const struct file_operations proc_pagemap_operations = { 2520 .llseek = mem_lseek, /* borrow this */ 2521 .read = pagemap_read, 2522 .open = pagemap_open, 2523 .release = pagemap_release, 2524 .unlocked_ioctl = do_pagemap_cmd, 2525 .compat_ioctl = do_pagemap_cmd, 2526 }; 2527 #endif /* CONFIG_PROC_PAGE_MONITOR */ 2528 2529 #ifdef CONFIG_NUMA 2530 2531 struct numa_maps { 2532 unsigned long pages; 2533 unsigned long anon; 2534 unsigned long active; 2535 unsigned long writeback; 2536 unsigned long mapcount_max; 2537 unsigned long dirty; 2538 unsigned long swapcache; 2539 unsigned long node[MAX_NUMNODES]; 2540 }; 2541 2542 struct numa_maps_private { 2543 struct proc_maps_private proc_maps; 2544 struct numa_maps md; 2545 }; 2546 2547 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 2548 unsigned long nr_pages) 2549 { 2550 int count = page_mapcount(page); 2551 2552 md->pages += nr_pages; 2553 if (pte_dirty || PageDirty(page)) 2554 md->dirty += nr_pages; 2555 2556 if (PageSwapCache(page)) 2557 md->swapcache += nr_pages; 2558 2559 if (PageActive(page) || PageUnevictable(page)) 2560 md->active += nr_pages; 2561 2562 if (PageWriteback(page)) 2563 md->writeback += nr_pages; 2564 2565 if (PageAnon(page)) 2566 md->anon += nr_pages; 2567 2568 if (count > md->mapcount_max) 2569 md->mapcount_max = count; 2570 2571 md->node[page_to_nid(page)] += nr_pages; 2572 } 2573 2574 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 2575 unsigned long addr) 2576 { 2577 struct page *page; 2578 int nid; 2579 2580 if (!pte_present(pte)) 2581 return NULL; 2582 2583 page = vm_normal_page(vma, addr, pte); 2584 if (!page || is_zone_device_page(page)) 2585 return NULL; 2586 2587 if (PageReserved(page)) 2588 return NULL; 2589 2590 nid = page_to_nid(page); 2591 if (!node_isset(nid, node_states[N_MEMORY])) 2592 return NULL; 2593 2594 return page; 2595 } 2596 2597 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2598 static struct page *can_gather_numa_stats_pmd(pmd_t pmd, 2599 struct vm_area_struct *vma, 2600 unsigned long addr) 2601 { 2602 struct page *page; 2603 int nid; 2604 2605 if (!pmd_present(pmd)) 2606 return NULL; 2607 2608 page = vm_normal_page_pmd(vma, addr, pmd); 2609 if (!page) 2610 return NULL; 2611 2612 if (PageReserved(page)) 2613 return NULL; 2614 2615 nid = page_to_nid(page); 2616 if (!node_isset(nid, node_states[N_MEMORY])) 2617 return NULL; 2618 2619 return page; 2620 } 2621 #endif 2622 2623 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 2624 unsigned long end, struct mm_walk *walk) 2625 { 2626 struct numa_maps *md = walk->private; 2627 struct vm_area_struct *vma = walk->vma; 2628 spinlock_t *ptl; 2629 pte_t *orig_pte; 2630 pte_t *pte; 2631 2632 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2633 ptl = pmd_trans_huge_lock(pmd, vma); 2634 if (ptl) { 2635 struct page *page; 2636 2637 page = can_gather_numa_stats_pmd(*pmd, vma, addr); 2638 if (page) 2639 gather_stats(page, md, pmd_dirty(*pmd), 2640 HPAGE_PMD_SIZE/PAGE_SIZE); 2641 spin_unlock(ptl); 2642 return 0; 2643 } 2644 #endif 2645 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 2646 if (!pte) { 2647 walk->action = ACTION_AGAIN; 2648 return 0; 2649 } 2650 do { 2651 pte_t ptent = ptep_get(pte); 2652 struct page *page = can_gather_numa_stats(ptent, vma, addr); 2653 if (!page) 2654 continue; 2655 gather_stats(page, md, pte_dirty(ptent), 1); 2656 2657 } while (pte++, addr += PAGE_SIZE, addr != end); 2658 pte_unmap_unlock(orig_pte, ptl); 2659 cond_resched(); 2660 return 0; 2661 } 2662 #ifdef CONFIG_HUGETLB_PAGE 2663 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2664 unsigned long addr, unsigned long end, struct mm_walk *walk) 2665 { 2666 pte_t huge_pte = huge_ptep_get(pte); 2667 struct numa_maps *md; 2668 struct page *page; 2669 2670 if (!pte_present(huge_pte)) 2671 return 0; 2672 2673 page = pte_page(huge_pte); 2674 2675 md = walk->private; 2676 gather_stats(page, md, pte_dirty(huge_pte), 1); 2677 return 0; 2678 } 2679 2680 #else 2681 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2682 unsigned long addr, unsigned long end, struct mm_walk *walk) 2683 { 2684 return 0; 2685 } 2686 #endif 2687 2688 static const struct mm_walk_ops show_numa_ops = { 2689 .hugetlb_entry = gather_hugetlb_stats, 2690 .pmd_entry = gather_pte_stats, 2691 .walk_lock = PGWALK_RDLOCK, 2692 }; 2693 2694 /* 2695 * Display pages allocated per node and memory policy via /proc. 2696 */ 2697 static int show_numa_map(struct seq_file *m, void *v) 2698 { 2699 struct numa_maps_private *numa_priv = m->private; 2700 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 2701 struct vm_area_struct *vma = v; 2702 struct numa_maps *md = &numa_priv->md; 2703 struct file *file = vma->vm_file; 2704 struct mm_struct *mm = vma->vm_mm; 2705 char buffer[64]; 2706 struct mempolicy *pol; 2707 pgoff_t ilx; 2708 int nid; 2709 2710 if (!mm) 2711 return 0; 2712 2713 /* Ensure we start with an empty set of numa_maps statistics. */ 2714 memset(md, 0, sizeof(*md)); 2715 2716 pol = __get_vma_policy(vma, vma->vm_start, &ilx); 2717 if (pol) { 2718 mpol_to_str(buffer, sizeof(buffer), pol); 2719 mpol_cond_put(pol); 2720 } else { 2721 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); 2722 } 2723 2724 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 2725 2726 if (file) { 2727 seq_puts(m, " file="); 2728 seq_path(m, file_user_path(file), "\n\t= "); 2729 } else if (vma_is_initial_heap(vma)) { 2730 seq_puts(m, " heap"); 2731 } else if (vma_is_initial_stack(vma)) { 2732 seq_puts(m, " stack"); 2733 } 2734 2735 if (is_vm_hugetlb_page(vma)) 2736 seq_puts(m, " huge"); 2737 2738 /* mmap_lock is held by m_start */ 2739 walk_page_vma(vma, &show_numa_ops, md); 2740 2741 if (!md->pages) 2742 goto out; 2743 2744 if (md->anon) 2745 seq_printf(m, " anon=%lu", md->anon); 2746 2747 if (md->dirty) 2748 seq_printf(m, " dirty=%lu", md->dirty); 2749 2750 if (md->pages != md->anon && md->pages != md->dirty) 2751 seq_printf(m, " mapped=%lu", md->pages); 2752 2753 if (md->mapcount_max > 1) 2754 seq_printf(m, " mapmax=%lu", md->mapcount_max); 2755 2756 if (md->swapcache) 2757 seq_printf(m, " swapcache=%lu", md->swapcache); 2758 2759 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 2760 seq_printf(m, " active=%lu", md->active); 2761 2762 if (md->writeback) 2763 seq_printf(m, " writeback=%lu", md->writeback); 2764 2765 for_each_node_state(nid, N_MEMORY) 2766 if (md->node[nid]) 2767 seq_printf(m, " N%d=%lu", nid, md->node[nid]); 2768 2769 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); 2770 out: 2771 seq_putc(m, '\n'); 2772 return 0; 2773 } 2774 2775 static const struct seq_operations proc_pid_numa_maps_op = { 2776 .start = m_start, 2777 .next = m_next, 2778 .stop = m_stop, 2779 .show = show_numa_map, 2780 }; 2781 2782 static int pid_numa_maps_open(struct inode *inode, struct file *file) 2783 { 2784 return proc_maps_open(inode, file, &proc_pid_numa_maps_op, 2785 sizeof(struct numa_maps_private)); 2786 } 2787 2788 const struct file_operations proc_pid_numa_maps_operations = { 2789 .open = pid_numa_maps_open, 2790 .read = seq_read, 2791 .llseek = seq_lseek, 2792 .release = proc_map_release, 2793 }; 2794 2795 #endif /* CONFIG_NUMA */ 2796