1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/mm.h> 3 #include <linux/vmacache.h> 4 #include <linux/hugetlb.h> 5 #include <linux/huge_mm.h> 6 #include <linux/mount.h> 7 #include <linux/seq_file.h> 8 #include <linux/highmem.h> 9 #include <linux/ptrace.h> 10 #include <linux/slab.h> 11 #include <linux/pagemap.h> 12 #include <linux/mempolicy.h> 13 #include <linux/rmap.h> 14 #include <linux/swap.h> 15 #include <linux/sched/mm.h> 16 #include <linux/swapops.h> 17 #include <linux/mmu_notifier.h> 18 #include <linux/page_idle.h> 19 #include <linux/shmem_fs.h> 20 #include <linux/uaccess.h> 21 #include <linux/pkeys.h> 22 23 #include <asm/elf.h> 24 #include <asm/tlb.h> 25 #include <asm/tlbflush.h> 26 #include "internal.h" 27 28 #define SEQ_PUT_DEC(str, val) \ 29 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8) 30 void task_mem(struct seq_file *m, struct mm_struct *mm) 31 { 32 unsigned long text, lib, swap, anon, file, shmem; 33 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; 34 35 anon = get_mm_counter(mm, MM_ANONPAGES); 36 file = get_mm_counter(mm, MM_FILEPAGES); 37 shmem = get_mm_counter(mm, MM_SHMEMPAGES); 38 39 /* 40 * Note: to minimize their overhead, mm maintains hiwater_vm and 41 * hiwater_rss only when about to *lower* total_vm or rss. Any 42 * collector of these hiwater stats must therefore get total_vm 43 * and rss too, which will usually be the higher. Barriers? not 44 * worth the effort, such snapshots can always be inconsistent. 45 */ 46 hiwater_vm = total_vm = mm->total_vm; 47 if (hiwater_vm < mm->hiwater_vm) 48 hiwater_vm = mm->hiwater_vm; 49 hiwater_rss = total_rss = anon + file + shmem; 50 if (hiwater_rss < mm->hiwater_rss) 51 hiwater_rss = mm->hiwater_rss; 52 53 /* split executable areas between text and lib */ 54 text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK); 55 text = min(text, mm->exec_vm << PAGE_SHIFT); 56 lib = (mm->exec_vm << PAGE_SHIFT) - text; 57 58 swap = get_mm_counter(mm, MM_SWAPENTS); 59 SEQ_PUT_DEC("VmPeak:\t", hiwater_vm); 60 SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm); 61 SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm); 62 SEQ_PUT_DEC(" kB\nVmPin:\t", mm->pinned_vm); 63 SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss); 64 SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss); 65 SEQ_PUT_DEC(" kB\nRssAnon:\t", anon); 66 SEQ_PUT_DEC(" kB\nRssFile:\t", file); 67 SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem); 68 SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm); 69 SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm); 70 seq_put_decimal_ull_width(m, 71 " kB\nVmExe:\t", text >> 10, 8); 72 seq_put_decimal_ull_width(m, 73 " kB\nVmLib:\t", lib >> 10, 8); 74 seq_put_decimal_ull_width(m, 75 " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); 76 SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); 77 seq_puts(m, " kB\n"); 78 hugetlb_report_usage(m, mm); 79 } 80 #undef SEQ_PUT_DEC 81 82 unsigned long task_vsize(struct mm_struct *mm) 83 { 84 return PAGE_SIZE * mm->total_vm; 85 } 86 87 unsigned long task_statm(struct mm_struct *mm, 88 unsigned long *shared, unsigned long *text, 89 unsigned long *data, unsigned long *resident) 90 { 91 *shared = get_mm_counter(mm, MM_FILEPAGES) + 92 get_mm_counter(mm, MM_SHMEMPAGES); 93 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 94 >> PAGE_SHIFT; 95 *data = mm->data_vm + mm->stack_vm; 96 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); 97 return mm->total_vm; 98 } 99 100 #ifdef CONFIG_NUMA 101 /* 102 * Save get_task_policy() for show_numa_map(). 103 */ 104 static void hold_task_mempolicy(struct proc_maps_private *priv) 105 { 106 struct task_struct *task = priv->task; 107 108 task_lock(task); 109 priv->task_mempolicy = get_task_policy(task); 110 mpol_get(priv->task_mempolicy); 111 task_unlock(task); 112 } 113 static void release_task_mempolicy(struct proc_maps_private *priv) 114 { 115 mpol_put(priv->task_mempolicy); 116 } 117 #else 118 static void hold_task_mempolicy(struct proc_maps_private *priv) 119 { 120 } 121 static void release_task_mempolicy(struct proc_maps_private *priv) 122 { 123 } 124 #endif 125 126 static void vma_stop(struct proc_maps_private *priv) 127 { 128 struct mm_struct *mm = priv->mm; 129 130 release_task_mempolicy(priv); 131 up_read(&mm->mmap_sem); 132 mmput(mm); 133 } 134 135 static struct vm_area_struct * 136 m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma) 137 { 138 if (vma == priv->tail_vma) 139 return NULL; 140 return vma->vm_next ?: priv->tail_vma; 141 } 142 143 static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma) 144 { 145 if (m->count < m->size) /* vma is copied successfully */ 146 m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL; 147 } 148 149 static void *m_start(struct seq_file *m, loff_t *ppos) 150 { 151 struct proc_maps_private *priv = m->private; 152 unsigned long last_addr = m->version; 153 struct mm_struct *mm; 154 struct vm_area_struct *vma; 155 unsigned int pos = *ppos; 156 157 /* See m_cache_vma(). Zero at the start or after lseek. */ 158 if (last_addr == -1UL) 159 return NULL; 160 161 priv->task = get_proc_task(priv->inode); 162 if (!priv->task) 163 return ERR_PTR(-ESRCH); 164 165 mm = priv->mm; 166 if (!mm || !mmget_not_zero(mm)) 167 return NULL; 168 169 down_read(&mm->mmap_sem); 170 hold_task_mempolicy(priv); 171 priv->tail_vma = get_gate_vma(mm); 172 173 if (last_addr) { 174 vma = find_vma(mm, last_addr - 1); 175 if (vma && vma->vm_start <= last_addr) 176 vma = m_next_vma(priv, vma); 177 if (vma) 178 return vma; 179 } 180 181 m->version = 0; 182 if (pos < mm->map_count) { 183 for (vma = mm->mmap; pos; pos--) { 184 m->version = vma->vm_start; 185 vma = vma->vm_next; 186 } 187 return vma; 188 } 189 190 /* we do not bother to update m->version in this case */ 191 if (pos == mm->map_count && priv->tail_vma) 192 return priv->tail_vma; 193 194 vma_stop(priv); 195 return NULL; 196 } 197 198 static void *m_next(struct seq_file *m, void *v, loff_t *pos) 199 { 200 struct proc_maps_private *priv = m->private; 201 struct vm_area_struct *next; 202 203 (*pos)++; 204 next = m_next_vma(priv, v); 205 if (!next) 206 vma_stop(priv); 207 return next; 208 } 209 210 static void m_stop(struct seq_file *m, void *v) 211 { 212 struct proc_maps_private *priv = m->private; 213 214 if (!IS_ERR_OR_NULL(v)) 215 vma_stop(priv); 216 if (priv->task) { 217 put_task_struct(priv->task); 218 priv->task = NULL; 219 } 220 } 221 222 static int proc_maps_open(struct inode *inode, struct file *file, 223 const struct seq_operations *ops, int psize) 224 { 225 struct proc_maps_private *priv = __seq_open_private(file, ops, psize); 226 227 if (!priv) 228 return -ENOMEM; 229 230 priv->inode = inode; 231 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 232 if (IS_ERR(priv->mm)) { 233 int err = PTR_ERR(priv->mm); 234 235 seq_release_private(inode, file); 236 return err; 237 } 238 239 return 0; 240 } 241 242 static int proc_map_release(struct inode *inode, struct file *file) 243 { 244 struct seq_file *seq = file->private_data; 245 struct proc_maps_private *priv = seq->private; 246 247 if (priv->mm) 248 mmdrop(priv->mm); 249 250 return seq_release_private(inode, file); 251 } 252 253 static int do_maps_open(struct inode *inode, struct file *file, 254 const struct seq_operations *ops) 255 { 256 return proc_maps_open(inode, file, ops, 257 sizeof(struct proc_maps_private)); 258 } 259 260 /* 261 * Indicate if the VMA is a stack for the given task; for 262 * /proc/PID/maps that is the stack of the main task. 263 */ 264 static int is_stack(struct vm_area_struct *vma) 265 { 266 /* 267 * We make no effort to guess what a given thread considers to be 268 * its "stack". It's not even well-defined for programs written 269 * languages like Go. 270 */ 271 return vma->vm_start <= vma->vm_mm->start_stack && 272 vma->vm_end >= vma->vm_mm->start_stack; 273 } 274 275 static void show_vma_header_prefix(struct seq_file *m, 276 unsigned long start, unsigned long end, 277 vm_flags_t flags, unsigned long long pgoff, 278 dev_t dev, unsigned long ino) 279 { 280 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 281 seq_put_hex_ll(m, NULL, start, 8); 282 seq_put_hex_ll(m, "-", end, 8); 283 seq_putc(m, ' '); 284 seq_putc(m, flags & VM_READ ? 'r' : '-'); 285 seq_putc(m, flags & VM_WRITE ? 'w' : '-'); 286 seq_putc(m, flags & VM_EXEC ? 'x' : '-'); 287 seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p'); 288 seq_put_hex_ll(m, " ", pgoff, 8); 289 seq_put_hex_ll(m, " ", MAJOR(dev), 2); 290 seq_put_hex_ll(m, ":", MINOR(dev), 2); 291 seq_put_decimal_ull(m, " ", ino); 292 seq_putc(m, ' '); 293 } 294 295 static void 296 show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 297 { 298 struct mm_struct *mm = vma->vm_mm; 299 struct file *file = vma->vm_file; 300 vm_flags_t flags = vma->vm_flags; 301 unsigned long ino = 0; 302 unsigned long long pgoff = 0; 303 unsigned long start, end; 304 dev_t dev = 0; 305 const char *name = NULL; 306 307 if (file) { 308 struct inode *inode = file_inode(vma->vm_file); 309 dev = inode->i_sb->s_dev; 310 ino = inode->i_ino; 311 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 312 } 313 314 start = vma->vm_start; 315 end = vma->vm_end; 316 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino); 317 318 /* 319 * Print the dentry name for named mappings, and a 320 * special [heap] marker for the heap: 321 */ 322 if (file) { 323 seq_pad(m, ' '); 324 seq_file_path(m, file, "\n"); 325 goto done; 326 } 327 328 if (vma->vm_ops && vma->vm_ops->name) { 329 name = vma->vm_ops->name(vma); 330 if (name) 331 goto done; 332 } 333 334 name = arch_vma_name(vma); 335 if (!name) { 336 if (!mm) { 337 name = "[vdso]"; 338 goto done; 339 } 340 341 if (vma->vm_start <= mm->brk && 342 vma->vm_end >= mm->start_brk) { 343 name = "[heap]"; 344 goto done; 345 } 346 347 if (is_stack(vma)) 348 name = "[stack]"; 349 } 350 351 done: 352 if (name) { 353 seq_pad(m, ' '); 354 seq_puts(m, name); 355 } 356 seq_putc(m, '\n'); 357 } 358 359 static int show_map(struct seq_file *m, void *v) 360 { 361 show_map_vma(m, v); 362 m_cache_vma(m, v); 363 return 0; 364 } 365 366 static const struct seq_operations proc_pid_maps_op = { 367 .start = m_start, 368 .next = m_next, 369 .stop = m_stop, 370 .show = show_map 371 }; 372 373 static int pid_maps_open(struct inode *inode, struct file *file) 374 { 375 return do_maps_open(inode, file, &proc_pid_maps_op); 376 } 377 378 const struct file_operations proc_pid_maps_operations = { 379 .open = pid_maps_open, 380 .read = seq_read, 381 .llseek = seq_lseek, 382 .release = proc_map_release, 383 }; 384 385 /* 386 * Proportional Set Size(PSS): my share of RSS. 387 * 388 * PSS of a process is the count of pages it has in memory, where each 389 * page is divided by the number of processes sharing it. So if a 390 * process has 1000 pages all to itself, and 1000 shared with one other 391 * process, its PSS will be 1500. 392 * 393 * To keep (accumulated) division errors low, we adopt a 64bit 394 * fixed-point pss counter to minimize division errors. So (pss >> 395 * PSS_SHIFT) would be the real byte count. 396 * 397 * A shift of 12 before division means (assuming 4K page size): 398 * - 1M 3-user-pages add up to 8KB errors; 399 * - supports mapcount up to 2^24, or 16M; 400 * - supports PSS up to 2^52 bytes, or 4PB. 401 */ 402 #define PSS_SHIFT 12 403 404 #ifdef CONFIG_PROC_PAGE_MONITOR 405 struct mem_size_stats { 406 unsigned long resident; 407 unsigned long shared_clean; 408 unsigned long shared_dirty; 409 unsigned long private_clean; 410 unsigned long private_dirty; 411 unsigned long referenced; 412 unsigned long anonymous; 413 unsigned long lazyfree; 414 unsigned long anonymous_thp; 415 unsigned long shmem_thp; 416 unsigned long swap; 417 unsigned long shared_hugetlb; 418 unsigned long private_hugetlb; 419 u64 pss; 420 u64 pss_locked; 421 u64 swap_pss; 422 bool check_shmem_swap; 423 }; 424 425 static void smaps_account(struct mem_size_stats *mss, struct page *page, 426 bool compound, bool young, bool dirty) 427 { 428 int i, nr = compound ? 1 << compound_order(page) : 1; 429 unsigned long size = nr * PAGE_SIZE; 430 431 if (PageAnon(page)) { 432 mss->anonymous += size; 433 if (!PageSwapBacked(page) && !dirty && !PageDirty(page)) 434 mss->lazyfree += size; 435 } 436 437 mss->resident += size; 438 /* Accumulate the size in pages that have been accessed. */ 439 if (young || page_is_young(page) || PageReferenced(page)) 440 mss->referenced += size; 441 442 /* 443 * page_count(page) == 1 guarantees the page is mapped exactly once. 444 * If any subpage of the compound page mapped with PTE it would elevate 445 * page_count(). 446 */ 447 if (page_count(page) == 1) { 448 if (dirty || PageDirty(page)) 449 mss->private_dirty += size; 450 else 451 mss->private_clean += size; 452 mss->pss += (u64)size << PSS_SHIFT; 453 return; 454 } 455 456 for (i = 0; i < nr; i++, page++) { 457 int mapcount = page_mapcount(page); 458 459 if (mapcount >= 2) { 460 if (dirty || PageDirty(page)) 461 mss->shared_dirty += PAGE_SIZE; 462 else 463 mss->shared_clean += PAGE_SIZE; 464 mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount; 465 } else { 466 if (dirty || PageDirty(page)) 467 mss->private_dirty += PAGE_SIZE; 468 else 469 mss->private_clean += PAGE_SIZE; 470 mss->pss += PAGE_SIZE << PSS_SHIFT; 471 } 472 } 473 } 474 475 #ifdef CONFIG_SHMEM 476 static int smaps_pte_hole(unsigned long addr, unsigned long end, 477 struct mm_walk *walk) 478 { 479 struct mem_size_stats *mss = walk->private; 480 481 mss->swap += shmem_partial_swap_usage( 482 walk->vma->vm_file->f_mapping, addr, end); 483 484 return 0; 485 } 486 #endif 487 488 static void smaps_pte_entry(pte_t *pte, unsigned long addr, 489 struct mm_walk *walk) 490 { 491 struct mem_size_stats *mss = walk->private; 492 struct vm_area_struct *vma = walk->vma; 493 struct page *page = NULL; 494 495 if (pte_present(*pte)) { 496 page = vm_normal_page(vma, addr, *pte); 497 } else if (is_swap_pte(*pte)) { 498 swp_entry_t swpent = pte_to_swp_entry(*pte); 499 500 if (!non_swap_entry(swpent)) { 501 int mapcount; 502 503 mss->swap += PAGE_SIZE; 504 mapcount = swp_swapcount(swpent); 505 if (mapcount >= 2) { 506 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; 507 508 do_div(pss_delta, mapcount); 509 mss->swap_pss += pss_delta; 510 } else { 511 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; 512 } 513 } else if (is_migration_entry(swpent)) 514 page = migration_entry_to_page(swpent); 515 else if (is_device_private_entry(swpent)) 516 page = device_private_entry_to_page(swpent); 517 } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap 518 && pte_none(*pte))) { 519 page = find_get_entry(vma->vm_file->f_mapping, 520 linear_page_index(vma, addr)); 521 if (!page) 522 return; 523 524 if (xa_is_value(page)) 525 mss->swap += PAGE_SIZE; 526 else 527 put_page(page); 528 529 return; 530 } 531 532 if (!page) 533 return; 534 535 smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte)); 536 } 537 538 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 539 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 540 struct mm_walk *walk) 541 { 542 struct mem_size_stats *mss = walk->private; 543 struct vm_area_struct *vma = walk->vma; 544 struct page *page; 545 546 /* FOLL_DUMP will return -EFAULT on huge zero page */ 547 page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP); 548 if (IS_ERR_OR_NULL(page)) 549 return; 550 if (PageAnon(page)) 551 mss->anonymous_thp += HPAGE_PMD_SIZE; 552 else if (PageSwapBacked(page)) 553 mss->shmem_thp += HPAGE_PMD_SIZE; 554 else if (is_zone_device_page(page)) 555 /* pass */; 556 else 557 VM_BUG_ON_PAGE(1, page); 558 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); 559 } 560 #else 561 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 562 struct mm_walk *walk) 563 { 564 } 565 #endif 566 567 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 568 struct mm_walk *walk) 569 { 570 struct vm_area_struct *vma = walk->vma; 571 pte_t *pte; 572 spinlock_t *ptl; 573 574 ptl = pmd_trans_huge_lock(pmd, vma); 575 if (ptl) { 576 if (pmd_present(*pmd)) 577 smaps_pmd_entry(pmd, addr, walk); 578 spin_unlock(ptl); 579 goto out; 580 } 581 582 if (pmd_trans_unstable(pmd)) 583 goto out; 584 /* 585 * The mmap_sem held all the way back in m_start() is what 586 * keeps khugepaged out of here and from collapsing things 587 * in here. 588 */ 589 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 590 for (; addr != end; pte++, addr += PAGE_SIZE) 591 smaps_pte_entry(pte, addr, walk); 592 pte_unmap_unlock(pte - 1, ptl); 593 out: 594 cond_resched(); 595 return 0; 596 } 597 598 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) 599 { 600 /* 601 * Don't forget to update Documentation/ on changes. 602 */ 603 static const char mnemonics[BITS_PER_LONG][2] = { 604 /* 605 * In case if we meet a flag we don't know about. 606 */ 607 [0 ... (BITS_PER_LONG-1)] = "??", 608 609 [ilog2(VM_READ)] = "rd", 610 [ilog2(VM_WRITE)] = "wr", 611 [ilog2(VM_EXEC)] = "ex", 612 [ilog2(VM_SHARED)] = "sh", 613 [ilog2(VM_MAYREAD)] = "mr", 614 [ilog2(VM_MAYWRITE)] = "mw", 615 [ilog2(VM_MAYEXEC)] = "me", 616 [ilog2(VM_MAYSHARE)] = "ms", 617 [ilog2(VM_GROWSDOWN)] = "gd", 618 [ilog2(VM_PFNMAP)] = "pf", 619 [ilog2(VM_DENYWRITE)] = "dw", 620 #ifdef CONFIG_X86_INTEL_MPX 621 [ilog2(VM_MPX)] = "mp", 622 #endif 623 [ilog2(VM_LOCKED)] = "lo", 624 [ilog2(VM_IO)] = "io", 625 [ilog2(VM_SEQ_READ)] = "sr", 626 [ilog2(VM_RAND_READ)] = "rr", 627 [ilog2(VM_DONTCOPY)] = "dc", 628 [ilog2(VM_DONTEXPAND)] = "de", 629 [ilog2(VM_ACCOUNT)] = "ac", 630 [ilog2(VM_NORESERVE)] = "nr", 631 [ilog2(VM_HUGETLB)] = "ht", 632 [ilog2(VM_SYNC)] = "sf", 633 [ilog2(VM_ARCH_1)] = "ar", 634 [ilog2(VM_WIPEONFORK)] = "wf", 635 [ilog2(VM_DONTDUMP)] = "dd", 636 #ifdef CONFIG_MEM_SOFT_DIRTY 637 [ilog2(VM_SOFTDIRTY)] = "sd", 638 #endif 639 [ilog2(VM_MIXEDMAP)] = "mm", 640 [ilog2(VM_HUGEPAGE)] = "hg", 641 [ilog2(VM_NOHUGEPAGE)] = "nh", 642 [ilog2(VM_MERGEABLE)] = "mg", 643 [ilog2(VM_UFFD_MISSING)]= "um", 644 [ilog2(VM_UFFD_WP)] = "uw", 645 #ifdef CONFIG_ARCH_HAS_PKEYS 646 /* These come out via ProtectionKey: */ 647 [ilog2(VM_PKEY_BIT0)] = "", 648 [ilog2(VM_PKEY_BIT1)] = "", 649 [ilog2(VM_PKEY_BIT2)] = "", 650 [ilog2(VM_PKEY_BIT3)] = "", 651 #if VM_PKEY_BIT4 652 [ilog2(VM_PKEY_BIT4)] = "", 653 #endif 654 #endif /* CONFIG_ARCH_HAS_PKEYS */ 655 }; 656 size_t i; 657 658 seq_puts(m, "VmFlags: "); 659 for (i = 0; i < BITS_PER_LONG; i++) { 660 if (!mnemonics[i][0]) 661 continue; 662 if (vma->vm_flags & (1UL << i)) { 663 seq_putc(m, mnemonics[i][0]); 664 seq_putc(m, mnemonics[i][1]); 665 seq_putc(m, ' '); 666 } 667 } 668 seq_putc(m, '\n'); 669 } 670 671 #ifdef CONFIG_HUGETLB_PAGE 672 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, 673 unsigned long addr, unsigned long end, 674 struct mm_walk *walk) 675 { 676 struct mem_size_stats *mss = walk->private; 677 struct vm_area_struct *vma = walk->vma; 678 struct page *page = NULL; 679 680 if (pte_present(*pte)) { 681 page = vm_normal_page(vma, addr, *pte); 682 } else if (is_swap_pte(*pte)) { 683 swp_entry_t swpent = pte_to_swp_entry(*pte); 684 685 if (is_migration_entry(swpent)) 686 page = migration_entry_to_page(swpent); 687 else if (is_device_private_entry(swpent)) 688 page = device_private_entry_to_page(swpent); 689 } 690 if (page) { 691 int mapcount = page_mapcount(page); 692 693 if (mapcount >= 2) 694 mss->shared_hugetlb += huge_page_size(hstate_vma(vma)); 695 else 696 mss->private_hugetlb += huge_page_size(hstate_vma(vma)); 697 } 698 return 0; 699 } 700 #endif /* HUGETLB_PAGE */ 701 702 static void smap_gather_stats(struct vm_area_struct *vma, 703 struct mem_size_stats *mss) 704 { 705 struct mm_walk smaps_walk = { 706 .pmd_entry = smaps_pte_range, 707 #ifdef CONFIG_HUGETLB_PAGE 708 .hugetlb_entry = smaps_hugetlb_range, 709 #endif 710 .mm = vma->vm_mm, 711 }; 712 713 smaps_walk.private = mss; 714 715 #ifdef CONFIG_SHMEM 716 /* In case of smaps_rollup, reset the value from previous vma */ 717 mss->check_shmem_swap = false; 718 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { 719 /* 720 * For shared or readonly shmem mappings we know that all 721 * swapped out pages belong to the shmem object, and we can 722 * obtain the swap value much more efficiently. For private 723 * writable mappings, we might have COW pages that are 724 * not affected by the parent swapped out pages of the shmem 725 * object, so we have to distinguish them during the page walk. 726 * Unless we know that the shmem object (or the part mapped by 727 * our VMA) has no swapped out pages at all. 728 */ 729 unsigned long shmem_swapped = shmem_swap_usage(vma); 730 731 if (!shmem_swapped || (vma->vm_flags & VM_SHARED) || 732 !(vma->vm_flags & VM_WRITE)) { 733 mss->swap += shmem_swapped; 734 } else { 735 mss->check_shmem_swap = true; 736 smaps_walk.pte_hole = smaps_pte_hole; 737 } 738 } 739 #endif 740 741 /* mmap_sem is held in m_start */ 742 walk_page_vma(vma, &smaps_walk); 743 if (vma->vm_flags & VM_LOCKED) 744 mss->pss_locked += mss->pss; 745 } 746 747 #define SEQ_PUT_DEC(str, val) \ 748 seq_put_decimal_ull_width(m, str, (val) >> 10, 8) 749 750 /* Show the contents common for smaps and smaps_rollup */ 751 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss) 752 { 753 SEQ_PUT_DEC("Rss: ", mss->resident); 754 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT); 755 SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean); 756 SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty); 757 SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean); 758 SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty); 759 SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced); 760 SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous); 761 SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree); 762 SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp); 763 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp); 764 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb); 765 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ", 766 mss->private_hugetlb >> 10, 7); 767 SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); 768 SEQ_PUT_DEC(" kB\nSwapPss: ", 769 mss->swap_pss >> PSS_SHIFT); 770 SEQ_PUT_DEC(" kB\nLocked: ", 771 mss->pss_locked >> PSS_SHIFT); 772 seq_puts(m, " kB\n"); 773 } 774 775 static int show_smap(struct seq_file *m, void *v) 776 { 777 struct vm_area_struct *vma = v; 778 struct mem_size_stats mss; 779 780 memset(&mss, 0, sizeof(mss)); 781 782 smap_gather_stats(vma, &mss); 783 784 show_map_vma(m, vma); 785 786 SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start); 787 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma)); 788 SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma)); 789 seq_puts(m, " kB\n"); 790 791 __show_smap(m, &mss); 792 793 if (arch_pkeys_enabled()) 794 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); 795 show_smap_vma_flags(m, vma); 796 797 m_cache_vma(m, vma); 798 799 return 0; 800 } 801 802 static int show_smaps_rollup(struct seq_file *m, void *v) 803 { 804 struct proc_maps_private *priv = m->private; 805 struct mem_size_stats mss; 806 struct mm_struct *mm; 807 struct vm_area_struct *vma; 808 unsigned long last_vma_end = 0; 809 int ret = 0; 810 811 priv->task = get_proc_task(priv->inode); 812 if (!priv->task) 813 return -ESRCH; 814 815 mm = priv->mm; 816 if (!mm || !mmget_not_zero(mm)) { 817 ret = -ESRCH; 818 goto out_put_task; 819 } 820 821 memset(&mss, 0, sizeof(mss)); 822 823 down_read(&mm->mmap_sem); 824 hold_task_mempolicy(priv); 825 826 for (vma = priv->mm->mmap; vma; vma = vma->vm_next) { 827 smap_gather_stats(vma, &mss); 828 last_vma_end = vma->vm_end; 829 } 830 831 show_vma_header_prefix(m, priv->mm->mmap->vm_start, 832 last_vma_end, 0, 0, 0, 0); 833 seq_pad(m, ' '); 834 seq_puts(m, "[rollup]\n"); 835 836 __show_smap(m, &mss); 837 838 release_task_mempolicy(priv); 839 up_read(&mm->mmap_sem); 840 mmput(mm); 841 842 out_put_task: 843 put_task_struct(priv->task); 844 priv->task = NULL; 845 846 return ret; 847 } 848 #undef SEQ_PUT_DEC 849 850 static const struct seq_operations proc_pid_smaps_op = { 851 .start = m_start, 852 .next = m_next, 853 .stop = m_stop, 854 .show = show_smap 855 }; 856 857 static int pid_smaps_open(struct inode *inode, struct file *file) 858 { 859 return do_maps_open(inode, file, &proc_pid_smaps_op); 860 } 861 862 static int smaps_rollup_open(struct inode *inode, struct file *file) 863 { 864 int ret; 865 struct proc_maps_private *priv; 866 867 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT); 868 if (!priv) 869 return -ENOMEM; 870 871 ret = single_open(file, show_smaps_rollup, priv); 872 if (ret) 873 goto out_free; 874 875 priv->inode = inode; 876 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 877 if (IS_ERR(priv->mm)) { 878 ret = PTR_ERR(priv->mm); 879 880 single_release(inode, file); 881 goto out_free; 882 } 883 884 return 0; 885 886 out_free: 887 kfree(priv); 888 return ret; 889 } 890 891 static int smaps_rollup_release(struct inode *inode, struct file *file) 892 { 893 struct seq_file *seq = file->private_data; 894 struct proc_maps_private *priv = seq->private; 895 896 if (priv->mm) 897 mmdrop(priv->mm); 898 899 kfree(priv); 900 return single_release(inode, file); 901 } 902 903 const struct file_operations proc_pid_smaps_operations = { 904 .open = pid_smaps_open, 905 .read = seq_read, 906 .llseek = seq_lseek, 907 .release = proc_map_release, 908 }; 909 910 const struct file_operations proc_pid_smaps_rollup_operations = { 911 .open = smaps_rollup_open, 912 .read = seq_read, 913 .llseek = seq_lseek, 914 .release = smaps_rollup_release, 915 }; 916 917 enum clear_refs_types { 918 CLEAR_REFS_ALL = 1, 919 CLEAR_REFS_ANON, 920 CLEAR_REFS_MAPPED, 921 CLEAR_REFS_SOFT_DIRTY, 922 CLEAR_REFS_MM_HIWATER_RSS, 923 CLEAR_REFS_LAST, 924 }; 925 926 struct clear_refs_private { 927 enum clear_refs_types type; 928 }; 929 930 #ifdef CONFIG_MEM_SOFT_DIRTY 931 static inline void clear_soft_dirty(struct vm_area_struct *vma, 932 unsigned long addr, pte_t *pte) 933 { 934 /* 935 * The soft-dirty tracker uses #PF-s to catch writes 936 * to pages, so write-protect the pte as well. See the 937 * Documentation/admin-guide/mm/soft-dirty.rst for full description 938 * of how soft-dirty works. 939 */ 940 pte_t ptent = *pte; 941 942 if (pte_present(ptent)) { 943 ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte); 944 ptent = pte_wrprotect(ptent); 945 ptent = pte_clear_soft_dirty(ptent); 946 ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent); 947 } else if (is_swap_pte(ptent)) { 948 ptent = pte_swp_clear_soft_dirty(ptent); 949 set_pte_at(vma->vm_mm, addr, pte, ptent); 950 } 951 } 952 #else 953 static inline void clear_soft_dirty(struct vm_area_struct *vma, 954 unsigned long addr, pte_t *pte) 955 { 956 } 957 #endif 958 959 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 960 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 961 unsigned long addr, pmd_t *pmdp) 962 { 963 pmd_t old, pmd = *pmdp; 964 965 if (pmd_present(pmd)) { 966 /* See comment in change_huge_pmd() */ 967 old = pmdp_invalidate(vma, addr, pmdp); 968 if (pmd_dirty(old)) 969 pmd = pmd_mkdirty(pmd); 970 if (pmd_young(old)) 971 pmd = pmd_mkyoung(pmd); 972 973 pmd = pmd_wrprotect(pmd); 974 pmd = pmd_clear_soft_dirty(pmd); 975 976 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 977 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 978 pmd = pmd_swp_clear_soft_dirty(pmd); 979 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 980 } 981 } 982 #else 983 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 984 unsigned long addr, pmd_t *pmdp) 985 { 986 } 987 #endif 988 989 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 990 unsigned long end, struct mm_walk *walk) 991 { 992 struct clear_refs_private *cp = walk->private; 993 struct vm_area_struct *vma = walk->vma; 994 pte_t *pte, ptent; 995 spinlock_t *ptl; 996 struct page *page; 997 998 ptl = pmd_trans_huge_lock(pmd, vma); 999 if (ptl) { 1000 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1001 clear_soft_dirty_pmd(vma, addr, pmd); 1002 goto out; 1003 } 1004 1005 if (!pmd_present(*pmd)) 1006 goto out; 1007 1008 page = pmd_page(*pmd); 1009 1010 /* Clear accessed and referenced bits. */ 1011 pmdp_test_and_clear_young(vma, addr, pmd); 1012 test_and_clear_page_young(page); 1013 ClearPageReferenced(page); 1014 out: 1015 spin_unlock(ptl); 1016 return 0; 1017 } 1018 1019 if (pmd_trans_unstable(pmd)) 1020 return 0; 1021 1022 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 1023 for (; addr != end; pte++, addr += PAGE_SIZE) { 1024 ptent = *pte; 1025 1026 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1027 clear_soft_dirty(vma, addr, pte); 1028 continue; 1029 } 1030 1031 if (!pte_present(ptent)) 1032 continue; 1033 1034 page = vm_normal_page(vma, addr, ptent); 1035 if (!page) 1036 continue; 1037 1038 /* Clear accessed and referenced bits. */ 1039 ptep_test_and_clear_young(vma, addr, pte); 1040 test_and_clear_page_young(page); 1041 ClearPageReferenced(page); 1042 } 1043 pte_unmap_unlock(pte - 1, ptl); 1044 cond_resched(); 1045 return 0; 1046 } 1047 1048 static int clear_refs_test_walk(unsigned long start, unsigned long end, 1049 struct mm_walk *walk) 1050 { 1051 struct clear_refs_private *cp = walk->private; 1052 struct vm_area_struct *vma = walk->vma; 1053 1054 if (vma->vm_flags & VM_PFNMAP) 1055 return 1; 1056 1057 /* 1058 * Writing 1 to /proc/pid/clear_refs affects all pages. 1059 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. 1060 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. 1061 * Writing 4 to /proc/pid/clear_refs affects all pages. 1062 */ 1063 if (cp->type == CLEAR_REFS_ANON && vma->vm_file) 1064 return 1; 1065 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) 1066 return 1; 1067 return 0; 1068 } 1069 1070 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 1071 size_t count, loff_t *ppos) 1072 { 1073 struct task_struct *task; 1074 char buffer[PROC_NUMBUF]; 1075 struct mm_struct *mm; 1076 struct vm_area_struct *vma; 1077 enum clear_refs_types type; 1078 struct mmu_gather tlb; 1079 int itype; 1080 int rv; 1081 1082 memset(buffer, 0, sizeof(buffer)); 1083 if (count > sizeof(buffer) - 1) 1084 count = sizeof(buffer) - 1; 1085 if (copy_from_user(buffer, buf, count)) 1086 return -EFAULT; 1087 rv = kstrtoint(strstrip(buffer), 10, &itype); 1088 if (rv < 0) 1089 return rv; 1090 type = (enum clear_refs_types)itype; 1091 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) 1092 return -EINVAL; 1093 1094 task = get_proc_task(file_inode(file)); 1095 if (!task) 1096 return -ESRCH; 1097 mm = get_task_mm(task); 1098 if (mm) { 1099 struct clear_refs_private cp = { 1100 .type = type, 1101 }; 1102 struct mm_walk clear_refs_walk = { 1103 .pmd_entry = clear_refs_pte_range, 1104 .test_walk = clear_refs_test_walk, 1105 .mm = mm, 1106 .private = &cp, 1107 }; 1108 1109 if (type == CLEAR_REFS_MM_HIWATER_RSS) { 1110 if (down_write_killable(&mm->mmap_sem)) { 1111 count = -EINTR; 1112 goto out_mm; 1113 } 1114 1115 /* 1116 * Writing 5 to /proc/pid/clear_refs resets the peak 1117 * resident set size to this mm's current rss value. 1118 */ 1119 reset_mm_hiwater_rss(mm); 1120 up_write(&mm->mmap_sem); 1121 goto out_mm; 1122 } 1123 1124 down_read(&mm->mmap_sem); 1125 tlb_gather_mmu(&tlb, mm, 0, -1); 1126 if (type == CLEAR_REFS_SOFT_DIRTY) { 1127 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1128 if (!(vma->vm_flags & VM_SOFTDIRTY)) 1129 continue; 1130 up_read(&mm->mmap_sem); 1131 if (down_write_killable(&mm->mmap_sem)) { 1132 count = -EINTR; 1133 goto out_mm; 1134 } 1135 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1136 vma->vm_flags &= ~VM_SOFTDIRTY; 1137 vma_set_page_prot(vma); 1138 } 1139 downgrade_write(&mm->mmap_sem); 1140 break; 1141 } 1142 mmu_notifier_invalidate_range_start(mm, 0, -1); 1143 } 1144 walk_page_range(0, mm->highest_vm_end, &clear_refs_walk); 1145 if (type == CLEAR_REFS_SOFT_DIRTY) 1146 mmu_notifier_invalidate_range_end(mm, 0, -1); 1147 tlb_finish_mmu(&tlb, 0, -1); 1148 up_read(&mm->mmap_sem); 1149 out_mm: 1150 mmput(mm); 1151 } 1152 put_task_struct(task); 1153 1154 return count; 1155 } 1156 1157 const struct file_operations proc_clear_refs_operations = { 1158 .write = clear_refs_write, 1159 .llseek = noop_llseek, 1160 }; 1161 1162 typedef struct { 1163 u64 pme; 1164 } pagemap_entry_t; 1165 1166 struct pagemapread { 1167 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */ 1168 pagemap_entry_t *buffer; 1169 bool show_pfn; 1170 }; 1171 1172 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 1173 #define PAGEMAP_WALK_MASK (PMD_MASK) 1174 1175 #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) 1176 #define PM_PFRAME_BITS 55 1177 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) 1178 #define PM_SOFT_DIRTY BIT_ULL(55) 1179 #define PM_MMAP_EXCLUSIVE BIT_ULL(56) 1180 #define PM_FILE BIT_ULL(61) 1181 #define PM_SWAP BIT_ULL(62) 1182 #define PM_PRESENT BIT_ULL(63) 1183 1184 #define PM_END_OF_BUFFER 1 1185 1186 static inline pagemap_entry_t make_pme(u64 frame, u64 flags) 1187 { 1188 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags }; 1189 } 1190 1191 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme, 1192 struct pagemapread *pm) 1193 { 1194 pm->buffer[pm->pos++] = *pme; 1195 if (pm->pos >= pm->len) 1196 return PM_END_OF_BUFFER; 1197 return 0; 1198 } 1199 1200 static int pagemap_pte_hole(unsigned long start, unsigned long end, 1201 struct mm_walk *walk) 1202 { 1203 struct pagemapread *pm = walk->private; 1204 unsigned long addr = start; 1205 int err = 0; 1206 1207 while (addr < end) { 1208 struct vm_area_struct *vma = find_vma(walk->mm, addr); 1209 pagemap_entry_t pme = make_pme(0, 0); 1210 /* End of address space hole, which we mark as non-present. */ 1211 unsigned long hole_end; 1212 1213 if (vma) 1214 hole_end = min(end, vma->vm_start); 1215 else 1216 hole_end = end; 1217 1218 for (; addr < hole_end; addr += PAGE_SIZE) { 1219 err = add_to_pagemap(addr, &pme, pm); 1220 if (err) 1221 goto out; 1222 } 1223 1224 if (!vma) 1225 break; 1226 1227 /* Addresses in the VMA. */ 1228 if (vma->vm_flags & VM_SOFTDIRTY) 1229 pme = make_pme(0, PM_SOFT_DIRTY); 1230 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { 1231 err = add_to_pagemap(addr, &pme, pm); 1232 if (err) 1233 goto out; 1234 } 1235 } 1236 out: 1237 return err; 1238 } 1239 1240 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 1241 struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1242 { 1243 u64 frame = 0, flags = 0; 1244 struct page *page = NULL; 1245 1246 if (pte_present(pte)) { 1247 if (pm->show_pfn) 1248 frame = pte_pfn(pte); 1249 flags |= PM_PRESENT; 1250 page = _vm_normal_page(vma, addr, pte, true); 1251 if (pte_soft_dirty(pte)) 1252 flags |= PM_SOFT_DIRTY; 1253 } else if (is_swap_pte(pte)) { 1254 swp_entry_t entry; 1255 if (pte_swp_soft_dirty(pte)) 1256 flags |= PM_SOFT_DIRTY; 1257 entry = pte_to_swp_entry(pte); 1258 if (pm->show_pfn) 1259 frame = swp_type(entry) | 1260 (swp_offset(entry) << MAX_SWAPFILES_SHIFT); 1261 flags |= PM_SWAP; 1262 if (is_migration_entry(entry)) 1263 page = migration_entry_to_page(entry); 1264 1265 if (is_device_private_entry(entry)) 1266 page = device_private_entry_to_page(entry); 1267 } 1268 1269 if (page && !PageAnon(page)) 1270 flags |= PM_FILE; 1271 if (page && page_mapcount(page) == 1) 1272 flags |= PM_MMAP_EXCLUSIVE; 1273 if (vma->vm_flags & VM_SOFTDIRTY) 1274 flags |= PM_SOFT_DIRTY; 1275 1276 return make_pme(frame, flags); 1277 } 1278 1279 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, 1280 struct mm_walk *walk) 1281 { 1282 struct vm_area_struct *vma = walk->vma; 1283 struct pagemapread *pm = walk->private; 1284 spinlock_t *ptl; 1285 pte_t *pte, *orig_pte; 1286 int err = 0; 1287 1288 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1289 ptl = pmd_trans_huge_lock(pmdp, vma); 1290 if (ptl) { 1291 u64 flags = 0, frame = 0; 1292 pmd_t pmd = *pmdp; 1293 struct page *page = NULL; 1294 1295 if (vma->vm_flags & VM_SOFTDIRTY) 1296 flags |= PM_SOFT_DIRTY; 1297 1298 if (pmd_present(pmd)) { 1299 page = pmd_page(pmd); 1300 1301 flags |= PM_PRESENT; 1302 if (pmd_soft_dirty(pmd)) 1303 flags |= PM_SOFT_DIRTY; 1304 if (pm->show_pfn) 1305 frame = pmd_pfn(pmd) + 1306 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1307 } 1308 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1309 else if (is_swap_pmd(pmd)) { 1310 swp_entry_t entry = pmd_to_swp_entry(pmd); 1311 unsigned long offset; 1312 1313 if (pm->show_pfn) { 1314 offset = swp_offset(entry) + 1315 ((addr & ~PMD_MASK) >> PAGE_SHIFT); 1316 frame = swp_type(entry) | 1317 (offset << MAX_SWAPFILES_SHIFT); 1318 } 1319 flags |= PM_SWAP; 1320 if (pmd_swp_soft_dirty(pmd)) 1321 flags |= PM_SOFT_DIRTY; 1322 VM_BUG_ON(!is_pmd_migration_entry(pmd)); 1323 page = migration_entry_to_page(entry); 1324 } 1325 #endif 1326 1327 if (page && page_mapcount(page) == 1) 1328 flags |= PM_MMAP_EXCLUSIVE; 1329 1330 for (; addr != end; addr += PAGE_SIZE) { 1331 pagemap_entry_t pme = make_pme(frame, flags); 1332 1333 err = add_to_pagemap(addr, &pme, pm); 1334 if (err) 1335 break; 1336 if (pm->show_pfn) { 1337 if (flags & PM_PRESENT) 1338 frame++; 1339 else if (flags & PM_SWAP) 1340 frame += (1 << MAX_SWAPFILES_SHIFT); 1341 } 1342 } 1343 spin_unlock(ptl); 1344 return err; 1345 } 1346 1347 if (pmd_trans_unstable(pmdp)) 1348 return 0; 1349 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1350 1351 /* 1352 * We can assume that @vma always points to a valid one and @end never 1353 * goes beyond vma->vm_end. 1354 */ 1355 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); 1356 for (; addr < end; pte++, addr += PAGE_SIZE) { 1357 pagemap_entry_t pme; 1358 1359 pme = pte_to_pagemap_entry(pm, vma, addr, *pte); 1360 err = add_to_pagemap(addr, &pme, pm); 1361 if (err) 1362 break; 1363 } 1364 pte_unmap_unlock(orig_pte, ptl); 1365 1366 cond_resched(); 1367 1368 return err; 1369 } 1370 1371 #ifdef CONFIG_HUGETLB_PAGE 1372 /* This function walks within one hugetlb entry in the single call */ 1373 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 1374 unsigned long addr, unsigned long end, 1375 struct mm_walk *walk) 1376 { 1377 struct pagemapread *pm = walk->private; 1378 struct vm_area_struct *vma = walk->vma; 1379 u64 flags = 0, frame = 0; 1380 int err = 0; 1381 pte_t pte; 1382 1383 if (vma->vm_flags & VM_SOFTDIRTY) 1384 flags |= PM_SOFT_DIRTY; 1385 1386 pte = huge_ptep_get(ptep); 1387 if (pte_present(pte)) { 1388 struct page *page = pte_page(pte); 1389 1390 if (!PageAnon(page)) 1391 flags |= PM_FILE; 1392 1393 if (page_mapcount(page) == 1) 1394 flags |= PM_MMAP_EXCLUSIVE; 1395 1396 flags |= PM_PRESENT; 1397 if (pm->show_pfn) 1398 frame = pte_pfn(pte) + 1399 ((addr & ~hmask) >> PAGE_SHIFT); 1400 } 1401 1402 for (; addr != end; addr += PAGE_SIZE) { 1403 pagemap_entry_t pme = make_pme(frame, flags); 1404 1405 err = add_to_pagemap(addr, &pme, pm); 1406 if (err) 1407 return err; 1408 if (pm->show_pfn && (flags & PM_PRESENT)) 1409 frame++; 1410 } 1411 1412 cond_resched(); 1413 1414 return err; 1415 } 1416 #endif /* HUGETLB_PAGE */ 1417 1418 /* 1419 * /proc/pid/pagemap - an array mapping virtual pages to pfns 1420 * 1421 * For each page in the address space, this file contains one 64-bit entry 1422 * consisting of the following: 1423 * 1424 * Bits 0-54 page frame number (PFN) if present 1425 * Bits 0-4 swap type if swapped 1426 * Bits 5-54 swap offset if swapped 1427 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) 1428 * Bit 56 page exclusively mapped 1429 * Bits 57-60 zero 1430 * Bit 61 page is file-page or shared-anon 1431 * Bit 62 page swapped 1432 * Bit 63 page present 1433 * 1434 * If the page is not present but in swap, then the PFN contains an 1435 * encoding of the swap file number and the page's offset into the 1436 * swap. Unmapped pages return a null PFN. This allows determining 1437 * precisely which pages are mapped (or in swap) and comparing mapped 1438 * pages between processes. 1439 * 1440 * Efficient users of this interface will use /proc/pid/maps to 1441 * determine which areas of memory are actually mapped and llseek to 1442 * skip over unmapped regions. 1443 */ 1444 static ssize_t pagemap_read(struct file *file, char __user *buf, 1445 size_t count, loff_t *ppos) 1446 { 1447 struct mm_struct *mm = file->private_data; 1448 struct pagemapread pm; 1449 struct mm_walk pagemap_walk = {}; 1450 unsigned long src; 1451 unsigned long svpfn; 1452 unsigned long start_vaddr; 1453 unsigned long end_vaddr; 1454 int ret = 0, copied = 0; 1455 1456 if (!mm || !mmget_not_zero(mm)) 1457 goto out; 1458 1459 ret = -EINVAL; 1460 /* file position must be aligned */ 1461 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 1462 goto out_mm; 1463 1464 ret = 0; 1465 if (!count) 1466 goto out_mm; 1467 1468 /* do not disclose physical addresses: attack vector */ 1469 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); 1470 1471 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 1472 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); 1473 ret = -ENOMEM; 1474 if (!pm.buffer) 1475 goto out_mm; 1476 1477 pagemap_walk.pmd_entry = pagemap_pmd_range; 1478 pagemap_walk.pte_hole = pagemap_pte_hole; 1479 #ifdef CONFIG_HUGETLB_PAGE 1480 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; 1481 #endif 1482 pagemap_walk.mm = mm; 1483 pagemap_walk.private = ± 1484 1485 src = *ppos; 1486 svpfn = src / PM_ENTRY_BYTES; 1487 start_vaddr = svpfn << PAGE_SHIFT; 1488 end_vaddr = mm->task_size; 1489 1490 /* watch out for wraparound */ 1491 if (svpfn > mm->task_size >> PAGE_SHIFT) 1492 start_vaddr = end_vaddr; 1493 1494 /* 1495 * The odds are that this will stop walking way 1496 * before end_vaddr, because the length of the 1497 * user buffer is tracked in "pm", and the walk 1498 * will stop when we hit the end of the buffer. 1499 */ 1500 ret = 0; 1501 while (count && (start_vaddr < end_vaddr)) { 1502 int len; 1503 unsigned long end; 1504 1505 pm.pos = 0; 1506 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 1507 /* overflow ? */ 1508 if (end < start_vaddr || end > end_vaddr) 1509 end = end_vaddr; 1510 down_read(&mm->mmap_sem); 1511 ret = walk_page_range(start_vaddr, end, &pagemap_walk); 1512 up_read(&mm->mmap_sem); 1513 start_vaddr = end; 1514 1515 len = min(count, PM_ENTRY_BYTES * pm.pos); 1516 if (copy_to_user(buf, pm.buffer, len)) { 1517 ret = -EFAULT; 1518 goto out_free; 1519 } 1520 copied += len; 1521 buf += len; 1522 count -= len; 1523 } 1524 *ppos += copied; 1525 if (!ret || ret == PM_END_OF_BUFFER) 1526 ret = copied; 1527 1528 out_free: 1529 kfree(pm.buffer); 1530 out_mm: 1531 mmput(mm); 1532 out: 1533 return ret; 1534 } 1535 1536 static int pagemap_open(struct inode *inode, struct file *file) 1537 { 1538 struct mm_struct *mm; 1539 1540 mm = proc_mem_open(inode, PTRACE_MODE_READ); 1541 if (IS_ERR(mm)) 1542 return PTR_ERR(mm); 1543 file->private_data = mm; 1544 return 0; 1545 } 1546 1547 static int pagemap_release(struct inode *inode, struct file *file) 1548 { 1549 struct mm_struct *mm = file->private_data; 1550 1551 if (mm) 1552 mmdrop(mm); 1553 return 0; 1554 } 1555 1556 const struct file_operations proc_pagemap_operations = { 1557 .llseek = mem_lseek, /* borrow this */ 1558 .read = pagemap_read, 1559 .open = pagemap_open, 1560 .release = pagemap_release, 1561 }; 1562 #endif /* CONFIG_PROC_PAGE_MONITOR */ 1563 1564 #ifdef CONFIG_NUMA 1565 1566 struct numa_maps { 1567 unsigned long pages; 1568 unsigned long anon; 1569 unsigned long active; 1570 unsigned long writeback; 1571 unsigned long mapcount_max; 1572 unsigned long dirty; 1573 unsigned long swapcache; 1574 unsigned long node[MAX_NUMNODES]; 1575 }; 1576 1577 struct numa_maps_private { 1578 struct proc_maps_private proc_maps; 1579 struct numa_maps md; 1580 }; 1581 1582 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 1583 unsigned long nr_pages) 1584 { 1585 int count = page_mapcount(page); 1586 1587 md->pages += nr_pages; 1588 if (pte_dirty || PageDirty(page)) 1589 md->dirty += nr_pages; 1590 1591 if (PageSwapCache(page)) 1592 md->swapcache += nr_pages; 1593 1594 if (PageActive(page) || PageUnevictable(page)) 1595 md->active += nr_pages; 1596 1597 if (PageWriteback(page)) 1598 md->writeback += nr_pages; 1599 1600 if (PageAnon(page)) 1601 md->anon += nr_pages; 1602 1603 if (count > md->mapcount_max) 1604 md->mapcount_max = count; 1605 1606 md->node[page_to_nid(page)] += nr_pages; 1607 } 1608 1609 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 1610 unsigned long addr) 1611 { 1612 struct page *page; 1613 int nid; 1614 1615 if (!pte_present(pte)) 1616 return NULL; 1617 1618 page = vm_normal_page(vma, addr, pte); 1619 if (!page) 1620 return NULL; 1621 1622 if (PageReserved(page)) 1623 return NULL; 1624 1625 nid = page_to_nid(page); 1626 if (!node_isset(nid, node_states[N_MEMORY])) 1627 return NULL; 1628 1629 return page; 1630 } 1631 1632 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1633 static struct page *can_gather_numa_stats_pmd(pmd_t pmd, 1634 struct vm_area_struct *vma, 1635 unsigned long addr) 1636 { 1637 struct page *page; 1638 int nid; 1639 1640 if (!pmd_present(pmd)) 1641 return NULL; 1642 1643 page = vm_normal_page_pmd(vma, addr, pmd); 1644 if (!page) 1645 return NULL; 1646 1647 if (PageReserved(page)) 1648 return NULL; 1649 1650 nid = page_to_nid(page); 1651 if (!node_isset(nid, node_states[N_MEMORY])) 1652 return NULL; 1653 1654 return page; 1655 } 1656 #endif 1657 1658 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 1659 unsigned long end, struct mm_walk *walk) 1660 { 1661 struct numa_maps *md = walk->private; 1662 struct vm_area_struct *vma = walk->vma; 1663 spinlock_t *ptl; 1664 pte_t *orig_pte; 1665 pte_t *pte; 1666 1667 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1668 ptl = pmd_trans_huge_lock(pmd, vma); 1669 if (ptl) { 1670 struct page *page; 1671 1672 page = can_gather_numa_stats_pmd(*pmd, vma, addr); 1673 if (page) 1674 gather_stats(page, md, pmd_dirty(*pmd), 1675 HPAGE_PMD_SIZE/PAGE_SIZE); 1676 spin_unlock(ptl); 1677 return 0; 1678 } 1679 1680 if (pmd_trans_unstable(pmd)) 1681 return 0; 1682 #endif 1683 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 1684 do { 1685 struct page *page = can_gather_numa_stats(*pte, vma, addr); 1686 if (!page) 1687 continue; 1688 gather_stats(page, md, pte_dirty(*pte), 1); 1689 1690 } while (pte++, addr += PAGE_SIZE, addr != end); 1691 pte_unmap_unlock(orig_pte, ptl); 1692 cond_resched(); 1693 return 0; 1694 } 1695 #ifdef CONFIG_HUGETLB_PAGE 1696 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 1697 unsigned long addr, unsigned long end, struct mm_walk *walk) 1698 { 1699 pte_t huge_pte = huge_ptep_get(pte); 1700 struct numa_maps *md; 1701 struct page *page; 1702 1703 if (!pte_present(huge_pte)) 1704 return 0; 1705 1706 page = pte_page(huge_pte); 1707 if (!page) 1708 return 0; 1709 1710 md = walk->private; 1711 gather_stats(page, md, pte_dirty(huge_pte), 1); 1712 return 0; 1713 } 1714 1715 #else 1716 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 1717 unsigned long addr, unsigned long end, struct mm_walk *walk) 1718 { 1719 return 0; 1720 } 1721 #endif 1722 1723 /* 1724 * Display pages allocated per node and memory policy via /proc. 1725 */ 1726 static int show_numa_map(struct seq_file *m, void *v) 1727 { 1728 struct numa_maps_private *numa_priv = m->private; 1729 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 1730 struct vm_area_struct *vma = v; 1731 struct numa_maps *md = &numa_priv->md; 1732 struct file *file = vma->vm_file; 1733 struct mm_struct *mm = vma->vm_mm; 1734 struct mm_walk walk = { 1735 .hugetlb_entry = gather_hugetlb_stats, 1736 .pmd_entry = gather_pte_stats, 1737 .private = md, 1738 .mm = mm, 1739 }; 1740 struct mempolicy *pol; 1741 char buffer[64]; 1742 int nid; 1743 1744 if (!mm) 1745 return 0; 1746 1747 /* Ensure we start with an empty set of numa_maps statistics. */ 1748 memset(md, 0, sizeof(*md)); 1749 1750 pol = __get_vma_policy(vma, vma->vm_start); 1751 if (pol) { 1752 mpol_to_str(buffer, sizeof(buffer), pol); 1753 mpol_cond_put(pol); 1754 } else { 1755 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); 1756 } 1757 1758 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 1759 1760 if (file) { 1761 seq_puts(m, " file="); 1762 seq_file_path(m, file, "\n\t= "); 1763 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { 1764 seq_puts(m, " heap"); 1765 } else if (is_stack(vma)) { 1766 seq_puts(m, " stack"); 1767 } 1768 1769 if (is_vm_hugetlb_page(vma)) 1770 seq_puts(m, " huge"); 1771 1772 /* mmap_sem is held by m_start */ 1773 walk_page_vma(vma, &walk); 1774 1775 if (!md->pages) 1776 goto out; 1777 1778 if (md->anon) 1779 seq_printf(m, " anon=%lu", md->anon); 1780 1781 if (md->dirty) 1782 seq_printf(m, " dirty=%lu", md->dirty); 1783 1784 if (md->pages != md->anon && md->pages != md->dirty) 1785 seq_printf(m, " mapped=%lu", md->pages); 1786 1787 if (md->mapcount_max > 1) 1788 seq_printf(m, " mapmax=%lu", md->mapcount_max); 1789 1790 if (md->swapcache) 1791 seq_printf(m, " swapcache=%lu", md->swapcache); 1792 1793 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 1794 seq_printf(m, " active=%lu", md->active); 1795 1796 if (md->writeback) 1797 seq_printf(m, " writeback=%lu", md->writeback); 1798 1799 for_each_node_state(nid, N_MEMORY) 1800 if (md->node[nid]) 1801 seq_printf(m, " N%d=%lu", nid, md->node[nid]); 1802 1803 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); 1804 out: 1805 seq_putc(m, '\n'); 1806 m_cache_vma(m, vma); 1807 return 0; 1808 } 1809 1810 static const struct seq_operations proc_pid_numa_maps_op = { 1811 .start = m_start, 1812 .next = m_next, 1813 .stop = m_stop, 1814 .show = show_numa_map, 1815 }; 1816 1817 static int pid_numa_maps_open(struct inode *inode, struct file *file) 1818 { 1819 return proc_maps_open(inode, file, &proc_pid_numa_maps_op, 1820 sizeof(struct numa_maps_private)); 1821 } 1822 1823 const struct file_operations proc_pid_numa_maps_operations = { 1824 .open = pid_numa_maps_open, 1825 .read = seq_read, 1826 .llseek = seq_lseek, 1827 .release = proc_map_release, 1828 }; 1829 1830 #endif /* CONFIG_NUMA */ 1831