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 #include <linux/buildid.h> 26 27 #include <asm/elf.h> 28 #include <asm/tlb.h> 29 #include <asm/tlbflush.h> 30 #include "internal.h" 31 32 #define SEQ_PUT_DEC(str, val) \ 33 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8) 34 void task_mem(struct seq_file *m, struct mm_struct *mm) 35 { 36 unsigned long text, lib, swap, anon, file, shmem; 37 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; 38 39 anon = get_mm_counter(mm, MM_ANONPAGES); 40 file = get_mm_counter(mm, MM_FILEPAGES); 41 shmem = get_mm_counter(mm, MM_SHMEMPAGES); 42 43 /* 44 * Note: to minimize their overhead, mm maintains hiwater_vm and 45 * hiwater_rss only when about to *lower* total_vm or rss. Any 46 * collector of these hiwater stats must therefore get total_vm 47 * and rss too, which will usually be the higher. Barriers? not 48 * worth the effort, such snapshots can always be inconsistent. 49 */ 50 hiwater_vm = total_vm = mm->total_vm; 51 if (hiwater_vm < mm->hiwater_vm) 52 hiwater_vm = mm->hiwater_vm; 53 hiwater_rss = total_rss = anon + file + shmem; 54 if (hiwater_rss < mm->hiwater_rss) 55 hiwater_rss = mm->hiwater_rss; 56 57 /* split executable areas between text and lib */ 58 text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK); 59 text = min(text, mm->exec_vm << PAGE_SHIFT); 60 lib = (mm->exec_vm << PAGE_SHIFT) - text; 61 62 swap = get_mm_counter(mm, MM_SWAPENTS); 63 SEQ_PUT_DEC("VmPeak:\t", hiwater_vm); 64 SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm); 65 SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm); 66 SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm)); 67 SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss); 68 SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss); 69 SEQ_PUT_DEC(" kB\nRssAnon:\t", anon); 70 SEQ_PUT_DEC(" kB\nRssFile:\t", file); 71 SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem); 72 SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm); 73 SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm); 74 seq_put_decimal_ull_width(m, 75 " kB\nVmExe:\t", text >> 10, 8); 76 seq_put_decimal_ull_width(m, 77 " kB\nVmLib:\t", lib >> 10, 8); 78 seq_put_decimal_ull_width(m, 79 " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); 80 SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); 81 seq_puts(m, " kB\n"); 82 hugetlb_report_usage(m, mm); 83 } 84 #undef SEQ_PUT_DEC 85 86 unsigned long task_vsize(struct mm_struct *mm) 87 { 88 return PAGE_SIZE * mm->total_vm; 89 } 90 91 unsigned long task_statm(struct mm_struct *mm, 92 unsigned long *shared, unsigned long *text, 93 unsigned long *data, unsigned long *resident) 94 { 95 *shared = get_mm_counter(mm, MM_FILEPAGES) + 96 get_mm_counter(mm, MM_SHMEMPAGES); 97 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 98 >> PAGE_SHIFT; 99 *data = mm->data_vm + mm->stack_vm; 100 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); 101 return mm->total_vm; 102 } 103 104 #ifdef CONFIG_NUMA 105 /* 106 * Save get_task_policy() for show_numa_map(). 107 */ 108 static void hold_task_mempolicy(struct proc_maps_private *priv) 109 { 110 struct task_struct *task = priv->task; 111 112 task_lock(task); 113 priv->task_mempolicy = get_task_policy(task); 114 mpol_get(priv->task_mempolicy); 115 task_unlock(task); 116 } 117 static void release_task_mempolicy(struct proc_maps_private *priv) 118 { 119 mpol_put(priv->task_mempolicy); 120 } 121 #else 122 static void hold_task_mempolicy(struct proc_maps_private *priv) 123 { 124 } 125 static void release_task_mempolicy(struct proc_maps_private *priv) 126 { 127 } 128 #endif 129 130 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, 131 loff_t *ppos) 132 { 133 struct vm_area_struct *vma = vma_next(&priv->iter); 134 135 if (vma) { 136 *ppos = vma->vm_start; 137 } else { 138 *ppos = -2UL; 139 vma = get_gate_vma(priv->mm); 140 } 141 142 return vma; 143 } 144 145 static void *m_start(struct seq_file *m, loff_t *ppos) 146 { 147 struct proc_maps_private *priv = m->private; 148 unsigned long last_addr = *ppos; 149 struct mm_struct *mm; 150 151 /* See m_next(). Zero at the start or after lseek. */ 152 if (last_addr == -1UL) 153 return NULL; 154 155 priv->task = get_proc_task(priv->inode); 156 if (!priv->task) 157 return ERR_PTR(-ESRCH); 158 159 mm = priv->mm; 160 if (!mm || !mmget_not_zero(mm)) { 161 put_task_struct(priv->task); 162 priv->task = NULL; 163 return NULL; 164 } 165 166 if (mmap_read_lock_killable(mm)) { 167 mmput(mm); 168 put_task_struct(priv->task); 169 priv->task = NULL; 170 return ERR_PTR(-EINTR); 171 } 172 173 vma_iter_init(&priv->iter, mm, last_addr); 174 hold_task_mempolicy(priv); 175 if (last_addr == -2UL) 176 return get_gate_vma(mm); 177 178 return proc_get_vma(priv, ppos); 179 } 180 181 static void *m_next(struct seq_file *m, void *v, loff_t *ppos) 182 { 183 if (*ppos == -2UL) { 184 *ppos = -1UL; 185 return NULL; 186 } 187 return proc_get_vma(m->private, ppos); 188 } 189 190 static void m_stop(struct seq_file *m, void *v) 191 { 192 struct proc_maps_private *priv = m->private; 193 struct mm_struct *mm = priv->mm; 194 195 if (!priv->task) 196 return; 197 198 release_task_mempolicy(priv); 199 mmap_read_unlock(mm); 200 mmput(mm); 201 put_task_struct(priv->task); 202 priv->task = NULL; 203 } 204 205 static int proc_maps_open(struct inode *inode, struct file *file, 206 const struct seq_operations *ops, int psize) 207 { 208 struct proc_maps_private *priv = __seq_open_private(file, ops, psize); 209 210 if (!priv) 211 return -ENOMEM; 212 213 priv->inode = inode; 214 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 215 if (IS_ERR(priv->mm)) { 216 int err = PTR_ERR(priv->mm); 217 218 seq_release_private(inode, file); 219 return err; 220 } 221 222 return 0; 223 } 224 225 static int proc_map_release(struct inode *inode, struct file *file) 226 { 227 struct seq_file *seq = file->private_data; 228 struct proc_maps_private *priv = seq->private; 229 230 if (priv->mm) 231 mmdrop(priv->mm); 232 233 return seq_release_private(inode, file); 234 } 235 236 static int do_maps_open(struct inode *inode, struct file *file, 237 const struct seq_operations *ops) 238 { 239 return proc_maps_open(inode, file, ops, 240 sizeof(struct proc_maps_private)); 241 } 242 243 static void get_vma_name(struct vm_area_struct *vma, 244 const struct path **path, 245 const char **name, 246 const char **name_fmt) 247 { 248 struct anon_vma_name *anon_name = vma->vm_mm ? anon_vma_name(vma) : NULL; 249 250 *name = NULL; 251 *path = NULL; 252 *name_fmt = NULL; 253 254 /* 255 * Print the dentry name for named mappings, and a 256 * special [heap] marker for the heap: 257 */ 258 if (vma->vm_file) { 259 /* 260 * If user named this anon shared memory via 261 * prctl(PR_SET_VMA ..., use the provided name. 262 */ 263 if (anon_name) { 264 *name_fmt = "[anon_shmem:%s]"; 265 *name = anon_name->name; 266 } else { 267 *path = file_user_path(vma->vm_file); 268 } 269 return; 270 } 271 272 if (vma->vm_ops && vma->vm_ops->name) { 273 *name = vma->vm_ops->name(vma); 274 if (*name) 275 return; 276 } 277 278 *name = arch_vma_name(vma); 279 if (*name) 280 return; 281 282 if (!vma->vm_mm) { 283 *name = "[vdso]"; 284 return; 285 } 286 287 if (vma_is_initial_heap(vma)) { 288 *name = "[heap]"; 289 return; 290 } 291 292 if (vma_is_initial_stack(vma)) { 293 *name = "[stack]"; 294 return; 295 } 296 297 if (anon_name) { 298 *name_fmt = "[anon:%s]"; 299 *name = anon_name->name; 300 return; 301 } 302 } 303 304 static void show_vma_header_prefix(struct seq_file *m, 305 unsigned long start, unsigned long end, 306 vm_flags_t flags, unsigned long long pgoff, 307 dev_t dev, unsigned long ino) 308 { 309 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 310 seq_put_hex_ll(m, NULL, start, 8); 311 seq_put_hex_ll(m, "-", end, 8); 312 seq_putc(m, ' '); 313 seq_putc(m, flags & VM_READ ? 'r' : '-'); 314 seq_putc(m, flags & VM_WRITE ? 'w' : '-'); 315 seq_putc(m, flags & VM_EXEC ? 'x' : '-'); 316 seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p'); 317 seq_put_hex_ll(m, " ", pgoff, 8); 318 seq_put_hex_ll(m, " ", MAJOR(dev), 2); 319 seq_put_hex_ll(m, ":", MINOR(dev), 2); 320 seq_put_decimal_ull(m, " ", ino); 321 seq_putc(m, ' '); 322 } 323 324 static void 325 show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 326 { 327 const struct path *path; 328 const char *name_fmt, *name; 329 vm_flags_t flags = vma->vm_flags; 330 unsigned long ino = 0; 331 unsigned long long pgoff = 0; 332 unsigned long start, end; 333 dev_t dev = 0; 334 335 if (vma->vm_file) { 336 const struct inode *inode = file_user_inode(vma->vm_file); 337 338 dev = inode->i_sb->s_dev; 339 ino = inode->i_ino; 340 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 341 } 342 343 start = vma->vm_start; 344 end = vma->vm_end; 345 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino); 346 347 get_vma_name(vma, &path, &name, &name_fmt); 348 if (path) { 349 seq_pad(m, ' '); 350 seq_path(m, path, "\n"); 351 } else if (name_fmt) { 352 seq_pad(m, ' '); 353 seq_printf(m, name_fmt, name); 354 } else if (name) { 355 seq_pad(m, ' '); 356 seq_puts(m, name); 357 } 358 seq_putc(m, '\n'); 359 } 360 361 static int show_map(struct seq_file *m, void *v) 362 { 363 show_map_vma(m, v); 364 return 0; 365 } 366 367 static const struct seq_operations proc_pid_maps_op = { 368 .start = m_start, 369 .next = m_next, 370 .stop = m_stop, 371 .show = show_map 372 }; 373 374 static int pid_maps_open(struct inode *inode, struct file *file) 375 { 376 return do_maps_open(inode, file, &proc_pid_maps_op); 377 } 378 379 #define PROCMAP_QUERY_VMA_FLAGS ( \ 380 PROCMAP_QUERY_VMA_READABLE | \ 381 PROCMAP_QUERY_VMA_WRITABLE | \ 382 PROCMAP_QUERY_VMA_EXECUTABLE | \ 383 PROCMAP_QUERY_VMA_SHARED \ 384 ) 385 386 #define PROCMAP_QUERY_VALID_FLAGS_MASK ( \ 387 PROCMAP_QUERY_COVERING_OR_NEXT_VMA | \ 388 PROCMAP_QUERY_FILE_BACKED_VMA | \ 389 PROCMAP_QUERY_VMA_FLAGS \ 390 ) 391 392 static int query_vma_setup(struct mm_struct *mm) 393 { 394 return mmap_read_lock_killable(mm); 395 } 396 397 static void query_vma_teardown(struct mm_struct *mm, struct vm_area_struct *vma) 398 { 399 mmap_read_unlock(mm); 400 } 401 402 static struct vm_area_struct *query_vma_find_by_addr(struct mm_struct *mm, unsigned long addr) 403 { 404 return find_vma(mm, addr); 405 } 406 407 static struct vm_area_struct *query_matching_vma(struct mm_struct *mm, 408 unsigned long addr, u32 flags) 409 { 410 struct vm_area_struct *vma; 411 412 next_vma: 413 vma = query_vma_find_by_addr(mm, addr); 414 if (!vma) 415 goto no_vma; 416 417 /* user requested only file-backed VMA, keep iterating */ 418 if ((flags & PROCMAP_QUERY_FILE_BACKED_VMA) && !vma->vm_file) 419 goto skip_vma; 420 421 /* VMA permissions should satisfy query flags */ 422 if (flags & PROCMAP_QUERY_VMA_FLAGS) { 423 u32 perm = 0; 424 425 if (flags & PROCMAP_QUERY_VMA_READABLE) 426 perm |= VM_READ; 427 if (flags & PROCMAP_QUERY_VMA_WRITABLE) 428 perm |= VM_WRITE; 429 if (flags & PROCMAP_QUERY_VMA_EXECUTABLE) 430 perm |= VM_EXEC; 431 if (flags & PROCMAP_QUERY_VMA_SHARED) 432 perm |= VM_MAYSHARE; 433 434 if ((vma->vm_flags & perm) != perm) 435 goto skip_vma; 436 } 437 438 /* found covering VMA or user is OK with the matching next VMA */ 439 if ((flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA) || vma->vm_start <= addr) 440 return vma; 441 442 skip_vma: 443 /* 444 * If the user needs closest matching VMA, keep iterating. 445 */ 446 addr = vma->vm_end; 447 if (flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA) 448 goto next_vma; 449 450 no_vma: 451 return ERR_PTR(-ENOENT); 452 } 453 454 static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg) 455 { 456 struct procmap_query karg; 457 struct vm_area_struct *vma; 458 struct mm_struct *mm; 459 const char *name = NULL; 460 char build_id_buf[BUILD_ID_SIZE_MAX], *name_buf = NULL; 461 __u64 usize; 462 int err; 463 464 if (copy_from_user(&usize, (void __user *)uarg, sizeof(usize))) 465 return -EFAULT; 466 /* argument struct can never be that large, reject abuse */ 467 if (usize > PAGE_SIZE) 468 return -E2BIG; 469 /* argument struct should have at least query_flags and query_addr fields */ 470 if (usize < offsetofend(struct procmap_query, query_addr)) 471 return -EINVAL; 472 err = copy_struct_from_user(&karg, sizeof(karg), uarg, usize); 473 if (err) 474 return err; 475 476 /* reject unknown flags */ 477 if (karg.query_flags & ~PROCMAP_QUERY_VALID_FLAGS_MASK) 478 return -EINVAL; 479 /* either both buffer address and size are set, or both should be zero */ 480 if (!!karg.vma_name_size != !!karg.vma_name_addr) 481 return -EINVAL; 482 if (!!karg.build_id_size != !!karg.build_id_addr) 483 return -EINVAL; 484 485 mm = priv->mm; 486 if (!mm || !mmget_not_zero(mm)) 487 return -ESRCH; 488 489 err = query_vma_setup(mm); 490 if (err) { 491 mmput(mm); 492 return err; 493 } 494 495 vma = query_matching_vma(mm, karg.query_addr, karg.query_flags); 496 if (IS_ERR(vma)) { 497 err = PTR_ERR(vma); 498 vma = NULL; 499 goto out; 500 } 501 502 karg.vma_start = vma->vm_start; 503 karg.vma_end = vma->vm_end; 504 505 karg.vma_flags = 0; 506 if (vma->vm_flags & VM_READ) 507 karg.vma_flags |= PROCMAP_QUERY_VMA_READABLE; 508 if (vma->vm_flags & VM_WRITE) 509 karg.vma_flags |= PROCMAP_QUERY_VMA_WRITABLE; 510 if (vma->vm_flags & VM_EXEC) 511 karg.vma_flags |= PROCMAP_QUERY_VMA_EXECUTABLE; 512 if (vma->vm_flags & VM_MAYSHARE) 513 karg.vma_flags |= PROCMAP_QUERY_VMA_SHARED; 514 515 karg.vma_page_size = vma_kernel_pagesize(vma); 516 517 if (vma->vm_file) { 518 const struct inode *inode = file_user_inode(vma->vm_file); 519 520 karg.vma_offset = ((__u64)vma->vm_pgoff) << PAGE_SHIFT; 521 karg.dev_major = MAJOR(inode->i_sb->s_dev); 522 karg.dev_minor = MINOR(inode->i_sb->s_dev); 523 karg.inode = inode->i_ino; 524 } else { 525 karg.vma_offset = 0; 526 karg.dev_major = 0; 527 karg.dev_minor = 0; 528 karg.inode = 0; 529 } 530 531 if (karg.build_id_size) { 532 __u32 build_id_sz; 533 534 err = build_id_parse(vma, build_id_buf, &build_id_sz); 535 if (err) { 536 karg.build_id_size = 0; 537 } else { 538 if (karg.build_id_size < build_id_sz) { 539 err = -ENAMETOOLONG; 540 goto out; 541 } 542 karg.build_id_size = build_id_sz; 543 } 544 } 545 546 if (karg.vma_name_size) { 547 size_t name_buf_sz = min_t(size_t, PATH_MAX, karg.vma_name_size); 548 const struct path *path; 549 const char *name_fmt; 550 size_t name_sz = 0; 551 552 get_vma_name(vma, &path, &name, &name_fmt); 553 554 if (path || name_fmt || name) { 555 name_buf = kmalloc(name_buf_sz, GFP_KERNEL); 556 if (!name_buf) { 557 err = -ENOMEM; 558 goto out; 559 } 560 } 561 if (path) { 562 name = d_path(path, name_buf, name_buf_sz); 563 if (IS_ERR(name)) { 564 err = PTR_ERR(name); 565 goto out; 566 } 567 name_sz = name_buf + name_buf_sz - name; 568 } else if (name || name_fmt) { 569 name_sz = 1 + snprintf(name_buf, name_buf_sz, name_fmt ?: "%s", name); 570 name = name_buf; 571 } 572 if (name_sz > name_buf_sz) { 573 err = -ENAMETOOLONG; 574 goto out; 575 } 576 karg.vma_name_size = name_sz; 577 } 578 579 /* unlock vma or mmap_lock, and put mm_struct before copying data to user */ 580 query_vma_teardown(mm, vma); 581 mmput(mm); 582 583 if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr), 584 name, karg.vma_name_size)) { 585 kfree(name_buf); 586 return -EFAULT; 587 } 588 kfree(name_buf); 589 590 if (karg.build_id_size && copy_to_user(u64_to_user_ptr(karg.build_id_addr), 591 build_id_buf, karg.build_id_size)) 592 return -EFAULT; 593 594 if (copy_to_user(uarg, &karg, min_t(size_t, sizeof(karg), usize))) 595 return -EFAULT; 596 597 return 0; 598 599 out: 600 query_vma_teardown(mm, vma); 601 mmput(mm); 602 kfree(name_buf); 603 return err; 604 } 605 606 static long procfs_procmap_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 607 { 608 struct seq_file *seq = file->private_data; 609 struct proc_maps_private *priv = seq->private; 610 611 switch (cmd) { 612 case PROCMAP_QUERY: 613 return do_procmap_query(priv, (void __user *)arg); 614 default: 615 return -ENOIOCTLCMD; 616 } 617 } 618 619 const struct file_operations proc_pid_maps_operations = { 620 .open = pid_maps_open, 621 .read = seq_read, 622 .llseek = seq_lseek, 623 .release = proc_map_release, 624 .unlocked_ioctl = procfs_procmap_ioctl, 625 .compat_ioctl = compat_ptr_ioctl, 626 }; 627 628 /* 629 * Proportional Set Size(PSS): my share of RSS. 630 * 631 * PSS of a process is the count of pages it has in memory, where each 632 * page is divided by the number of processes sharing it. So if a 633 * process has 1000 pages all to itself, and 1000 shared with one other 634 * process, its PSS will be 1500. 635 * 636 * To keep (accumulated) division errors low, we adopt a 64bit 637 * fixed-point pss counter to minimize division errors. So (pss >> 638 * PSS_SHIFT) would be the real byte count. 639 * 640 * A shift of 12 before division means (assuming 4K page size): 641 * - 1M 3-user-pages add up to 8KB errors; 642 * - supports mapcount up to 2^24, or 16M; 643 * - supports PSS up to 2^52 bytes, or 4PB. 644 */ 645 #define PSS_SHIFT 12 646 647 #ifdef CONFIG_PROC_PAGE_MONITOR 648 struct mem_size_stats { 649 unsigned long resident; 650 unsigned long shared_clean; 651 unsigned long shared_dirty; 652 unsigned long private_clean; 653 unsigned long private_dirty; 654 unsigned long referenced; 655 unsigned long anonymous; 656 unsigned long lazyfree; 657 unsigned long anonymous_thp; 658 unsigned long shmem_thp; 659 unsigned long file_thp; 660 unsigned long swap; 661 unsigned long shared_hugetlb; 662 unsigned long private_hugetlb; 663 unsigned long ksm; 664 u64 pss; 665 u64 pss_anon; 666 u64 pss_file; 667 u64 pss_shmem; 668 u64 pss_dirty; 669 u64 pss_locked; 670 u64 swap_pss; 671 }; 672 673 static void smaps_page_accumulate(struct mem_size_stats *mss, 674 struct folio *folio, unsigned long size, unsigned long pss, 675 bool dirty, bool locked, bool private) 676 { 677 mss->pss += pss; 678 679 if (folio_test_anon(folio)) 680 mss->pss_anon += pss; 681 else if (folio_test_swapbacked(folio)) 682 mss->pss_shmem += pss; 683 else 684 mss->pss_file += pss; 685 686 if (locked) 687 mss->pss_locked += pss; 688 689 if (dirty || folio_test_dirty(folio)) { 690 mss->pss_dirty += pss; 691 if (private) 692 mss->private_dirty += size; 693 else 694 mss->shared_dirty += size; 695 } else { 696 if (private) 697 mss->private_clean += size; 698 else 699 mss->shared_clean += size; 700 } 701 } 702 703 static void smaps_account(struct mem_size_stats *mss, struct page *page, 704 bool compound, bool young, bool dirty, bool locked, 705 bool present) 706 { 707 struct folio *folio = page_folio(page); 708 int i, nr = compound ? compound_nr(page) : 1; 709 unsigned long size = nr * PAGE_SIZE; 710 711 /* 712 * First accumulate quantities that depend only on |size| and the type 713 * of the compound page. 714 */ 715 if (folio_test_anon(folio)) { 716 mss->anonymous += size; 717 if (!folio_test_swapbacked(folio) && !dirty && 718 !folio_test_dirty(folio)) 719 mss->lazyfree += size; 720 } 721 722 if (folio_test_ksm(folio)) 723 mss->ksm += size; 724 725 mss->resident += size; 726 /* Accumulate the size in pages that have been accessed. */ 727 if (young || folio_test_young(folio) || folio_test_referenced(folio)) 728 mss->referenced += size; 729 730 /* 731 * Then accumulate quantities that may depend on sharing, or that may 732 * differ page-by-page. 733 * 734 * refcount == 1 for present entries guarantees that the folio is mapped 735 * exactly once. For large folios this implies that exactly one 736 * PTE/PMD/... maps (a part of) this folio. 737 * 738 * Treat all non-present entries (where relying on the mapcount and 739 * refcount doesn't make sense) as "maybe shared, but not sure how 740 * often". We treat device private entries as being fake-present. 741 * 742 * Note that it would not be safe to read the mapcount especially for 743 * pages referenced by migration entries, even with the PTL held. 744 */ 745 if (folio_ref_count(folio) == 1 || !present) { 746 smaps_page_accumulate(mss, folio, size, size << PSS_SHIFT, 747 dirty, locked, present); 748 return; 749 } 750 /* 751 * We obtain a snapshot of the mapcount. Without holding the folio lock 752 * this snapshot can be slightly wrong as we cannot always read the 753 * mapcount atomically. 754 */ 755 for (i = 0; i < nr; i++, page++) { 756 int mapcount = folio_precise_page_mapcount(folio, page); 757 unsigned long pss = PAGE_SIZE << PSS_SHIFT; 758 if (mapcount >= 2) 759 pss /= mapcount; 760 smaps_page_accumulate(mss, folio, PAGE_SIZE, pss, 761 dirty, locked, mapcount < 2); 762 } 763 } 764 765 #ifdef CONFIG_SHMEM 766 static int smaps_pte_hole(unsigned long addr, unsigned long end, 767 __always_unused int depth, struct mm_walk *walk) 768 { 769 struct mem_size_stats *mss = walk->private; 770 struct vm_area_struct *vma = walk->vma; 771 772 mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping, 773 linear_page_index(vma, addr), 774 linear_page_index(vma, end)); 775 776 return 0; 777 } 778 #else 779 #define smaps_pte_hole NULL 780 #endif /* CONFIG_SHMEM */ 781 782 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk) 783 { 784 #ifdef CONFIG_SHMEM 785 if (walk->ops->pte_hole) { 786 /* depth is not used */ 787 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk); 788 } 789 #endif 790 } 791 792 static void smaps_pte_entry(pte_t *pte, unsigned long addr, 793 struct mm_walk *walk) 794 { 795 struct mem_size_stats *mss = walk->private; 796 struct vm_area_struct *vma = walk->vma; 797 bool locked = !!(vma->vm_flags & VM_LOCKED); 798 struct page *page = NULL; 799 bool present = false, young = false, dirty = false; 800 pte_t ptent = ptep_get(pte); 801 802 if (pte_present(ptent)) { 803 page = vm_normal_page(vma, addr, ptent); 804 young = pte_young(ptent); 805 dirty = pte_dirty(ptent); 806 present = true; 807 } else if (is_swap_pte(ptent)) { 808 swp_entry_t swpent = pte_to_swp_entry(ptent); 809 810 if (!non_swap_entry(swpent)) { 811 int mapcount; 812 813 mss->swap += PAGE_SIZE; 814 mapcount = swp_swapcount(swpent); 815 if (mapcount >= 2) { 816 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; 817 818 do_div(pss_delta, mapcount); 819 mss->swap_pss += pss_delta; 820 } else { 821 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; 822 } 823 } else if (is_pfn_swap_entry(swpent)) { 824 if (is_device_private_entry(swpent)) 825 present = true; 826 page = pfn_swap_entry_to_page(swpent); 827 } 828 } else { 829 smaps_pte_hole_lookup(addr, walk); 830 return; 831 } 832 833 if (!page) 834 return; 835 836 smaps_account(mss, page, false, young, dirty, locked, present); 837 } 838 839 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 840 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 841 struct mm_walk *walk) 842 { 843 struct mem_size_stats *mss = walk->private; 844 struct vm_area_struct *vma = walk->vma; 845 bool locked = !!(vma->vm_flags & VM_LOCKED); 846 struct page *page = NULL; 847 bool present = false; 848 struct folio *folio; 849 850 if (pmd_present(*pmd)) { 851 page = vm_normal_page_pmd(vma, addr, *pmd); 852 present = true; 853 } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) { 854 swp_entry_t entry = pmd_to_swp_entry(*pmd); 855 856 if (is_pfn_swap_entry(entry)) 857 page = pfn_swap_entry_to_page(entry); 858 } 859 if (IS_ERR_OR_NULL(page)) 860 return; 861 folio = page_folio(page); 862 if (folio_test_anon(folio)) 863 mss->anonymous_thp += HPAGE_PMD_SIZE; 864 else if (folio_test_swapbacked(folio)) 865 mss->shmem_thp += HPAGE_PMD_SIZE; 866 else if (folio_is_zone_device(folio)) 867 /* pass */; 868 else 869 mss->file_thp += HPAGE_PMD_SIZE; 870 871 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), 872 locked, present); 873 } 874 #else 875 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 876 struct mm_walk *walk) 877 { 878 } 879 #endif 880 881 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 882 struct mm_walk *walk) 883 { 884 struct vm_area_struct *vma = walk->vma; 885 pte_t *pte; 886 spinlock_t *ptl; 887 888 ptl = pmd_trans_huge_lock(pmd, vma); 889 if (ptl) { 890 smaps_pmd_entry(pmd, addr, walk); 891 spin_unlock(ptl); 892 goto out; 893 } 894 895 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 896 if (!pte) { 897 walk->action = ACTION_AGAIN; 898 return 0; 899 } 900 for (; addr != end; pte++, addr += PAGE_SIZE) 901 smaps_pte_entry(pte, addr, walk); 902 pte_unmap_unlock(pte - 1, ptl); 903 out: 904 cond_resched(); 905 return 0; 906 } 907 908 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) 909 { 910 /* 911 * Don't forget to update Documentation/ on changes. 912 * 913 * The length of the second argument of mnemonics[] 914 * needs to be 3 instead of previously set 2 915 * (i.e. from [BITS_PER_LONG][2] to [BITS_PER_LONG][3]) 916 * to avoid spurious 917 * -Werror=unterminated-string-initialization warning 918 * with GCC 15 919 */ 920 static const char mnemonics[BITS_PER_LONG][3] = { 921 /* 922 * In case if we meet a flag we don't know about. 923 */ 924 [0 ... (BITS_PER_LONG-1)] = "??", 925 926 [ilog2(VM_READ)] = "rd", 927 [ilog2(VM_WRITE)] = "wr", 928 [ilog2(VM_EXEC)] = "ex", 929 [ilog2(VM_SHARED)] = "sh", 930 [ilog2(VM_MAYREAD)] = "mr", 931 [ilog2(VM_MAYWRITE)] = "mw", 932 [ilog2(VM_MAYEXEC)] = "me", 933 [ilog2(VM_MAYSHARE)] = "ms", 934 [ilog2(VM_GROWSDOWN)] = "gd", 935 [ilog2(VM_PFNMAP)] = "pf", 936 [ilog2(VM_LOCKED)] = "lo", 937 [ilog2(VM_IO)] = "io", 938 [ilog2(VM_SEQ_READ)] = "sr", 939 [ilog2(VM_RAND_READ)] = "rr", 940 [ilog2(VM_DONTCOPY)] = "dc", 941 [ilog2(VM_DONTEXPAND)] = "de", 942 [ilog2(VM_LOCKONFAULT)] = "lf", 943 [ilog2(VM_ACCOUNT)] = "ac", 944 [ilog2(VM_NORESERVE)] = "nr", 945 [ilog2(VM_HUGETLB)] = "ht", 946 [ilog2(VM_SYNC)] = "sf", 947 [ilog2(VM_ARCH_1)] = "ar", 948 [ilog2(VM_WIPEONFORK)] = "wf", 949 [ilog2(VM_DONTDUMP)] = "dd", 950 #ifdef CONFIG_ARM64_BTI 951 [ilog2(VM_ARM64_BTI)] = "bt", 952 #endif 953 #ifdef CONFIG_MEM_SOFT_DIRTY 954 [ilog2(VM_SOFTDIRTY)] = "sd", 955 #endif 956 [ilog2(VM_MIXEDMAP)] = "mm", 957 [ilog2(VM_HUGEPAGE)] = "hg", 958 [ilog2(VM_NOHUGEPAGE)] = "nh", 959 [ilog2(VM_MERGEABLE)] = "mg", 960 [ilog2(VM_UFFD_MISSING)]= "um", 961 [ilog2(VM_UFFD_WP)] = "uw", 962 #ifdef CONFIG_ARM64_MTE 963 [ilog2(VM_MTE)] = "mt", 964 [ilog2(VM_MTE_ALLOWED)] = "", 965 #endif 966 #ifdef CONFIG_ARCH_HAS_PKEYS 967 /* These come out via ProtectionKey: */ 968 [ilog2(VM_PKEY_BIT0)] = "", 969 [ilog2(VM_PKEY_BIT1)] = "", 970 [ilog2(VM_PKEY_BIT2)] = "", 971 #if VM_PKEY_BIT3 972 [ilog2(VM_PKEY_BIT3)] = "", 973 #endif 974 #if VM_PKEY_BIT4 975 [ilog2(VM_PKEY_BIT4)] = "", 976 #endif 977 #endif /* CONFIG_ARCH_HAS_PKEYS */ 978 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR 979 [ilog2(VM_UFFD_MINOR)] = "ui", 980 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ 981 #ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK 982 [ilog2(VM_SHADOW_STACK)] = "ss", 983 #endif 984 #if defined(CONFIG_64BIT) || defined(CONFIG_PPC32) 985 [ilog2(VM_DROPPABLE)] = "dp", 986 #endif 987 #ifdef CONFIG_64BIT 988 [ilog2(VM_SEALED)] = "sl", 989 #endif 990 }; 991 size_t i; 992 993 seq_puts(m, "VmFlags: "); 994 for (i = 0; i < BITS_PER_LONG; i++) { 995 if (!mnemonics[i][0]) 996 continue; 997 if (vma->vm_flags & (1UL << i)) 998 seq_printf(m, "%s ", mnemonics[i]); 999 } 1000 seq_putc(m, '\n'); 1001 } 1002 1003 #ifdef CONFIG_HUGETLB_PAGE 1004 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, 1005 unsigned long addr, unsigned long end, 1006 struct mm_walk *walk) 1007 { 1008 struct mem_size_stats *mss = walk->private; 1009 struct vm_area_struct *vma = walk->vma; 1010 pte_t ptent = huge_ptep_get(walk->mm, addr, pte); 1011 struct folio *folio = NULL; 1012 bool present = false; 1013 1014 if (pte_present(ptent)) { 1015 folio = page_folio(pte_page(ptent)); 1016 present = true; 1017 } else if (is_swap_pte(ptent)) { 1018 swp_entry_t swpent = pte_to_swp_entry(ptent); 1019 1020 if (is_pfn_swap_entry(swpent)) 1021 folio = pfn_swap_entry_folio(swpent); 1022 } 1023 1024 if (folio) { 1025 /* We treat non-present entries as "maybe shared". */ 1026 if (!present || folio_likely_mapped_shared(folio) || 1027 hugetlb_pmd_shared(pte)) 1028 mss->shared_hugetlb += huge_page_size(hstate_vma(vma)); 1029 else 1030 mss->private_hugetlb += huge_page_size(hstate_vma(vma)); 1031 } 1032 return 0; 1033 } 1034 #else 1035 #define smaps_hugetlb_range NULL 1036 #endif /* HUGETLB_PAGE */ 1037 1038 static const struct mm_walk_ops smaps_walk_ops = { 1039 .pmd_entry = smaps_pte_range, 1040 .hugetlb_entry = smaps_hugetlb_range, 1041 .walk_lock = PGWALK_RDLOCK, 1042 }; 1043 1044 static const struct mm_walk_ops smaps_shmem_walk_ops = { 1045 .pmd_entry = smaps_pte_range, 1046 .hugetlb_entry = smaps_hugetlb_range, 1047 .pte_hole = smaps_pte_hole, 1048 .walk_lock = PGWALK_RDLOCK, 1049 }; 1050 1051 /* 1052 * Gather mem stats from @vma with the indicated beginning 1053 * address @start, and keep them in @mss. 1054 * 1055 * Use vm_start of @vma as the beginning address if @start is 0. 1056 */ 1057 static void smap_gather_stats(struct vm_area_struct *vma, 1058 struct mem_size_stats *mss, unsigned long start) 1059 { 1060 const struct mm_walk_ops *ops = &smaps_walk_ops; 1061 1062 /* Invalid start */ 1063 if (start >= vma->vm_end) 1064 return; 1065 1066 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { 1067 /* 1068 * For shared or readonly shmem mappings we know that all 1069 * swapped out pages belong to the shmem object, and we can 1070 * obtain the swap value much more efficiently. For private 1071 * writable mappings, we might have COW pages that are 1072 * not affected by the parent swapped out pages of the shmem 1073 * object, so we have to distinguish them during the page walk. 1074 * Unless we know that the shmem object (or the part mapped by 1075 * our VMA) has no swapped out pages at all. 1076 */ 1077 unsigned long shmem_swapped = shmem_swap_usage(vma); 1078 1079 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || 1080 !(vma->vm_flags & VM_WRITE))) { 1081 mss->swap += shmem_swapped; 1082 } else { 1083 ops = &smaps_shmem_walk_ops; 1084 } 1085 } 1086 1087 /* mmap_lock is held in m_start */ 1088 if (!start) 1089 walk_page_vma(vma, ops, mss); 1090 else 1091 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); 1092 } 1093 1094 #define SEQ_PUT_DEC(str, val) \ 1095 seq_put_decimal_ull_width(m, str, (val) >> 10, 8) 1096 1097 /* Show the contents common for smaps and smaps_rollup */ 1098 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss, 1099 bool rollup_mode) 1100 { 1101 SEQ_PUT_DEC("Rss: ", mss->resident); 1102 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT); 1103 SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT); 1104 if (rollup_mode) { 1105 /* 1106 * These are meaningful only for smaps_rollup, otherwise two of 1107 * them are zero, and the other one is the same as Pss. 1108 */ 1109 SEQ_PUT_DEC(" kB\nPss_Anon: ", 1110 mss->pss_anon >> PSS_SHIFT); 1111 SEQ_PUT_DEC(" kB\nPss_File: ", 1112 mss->pss_file >> PSS_SHIFT); 1113 SEQ_PUT_DEC(" kB\nPss_Shmem: ", 1114 mss->pss_shmem >> PSS_SHIFT); 1115 } 1116 SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean); 1117 SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty); 1118 SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean); 1119 SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty); 1120 SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced); 1121 SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous); 1122 SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm); 1123 SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree); 1124 SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp); 1125 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp); 1126 SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp); 1127 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb); 1128 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ", 1129 mss->private_hugetlb >> 10, 7); 1130 SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); 1131 SEQ_PUT_DEC(" kB\nSwapPss: ", 1132 mss->swap_pss >> PSS_SHIFT); 1133 SEQ_PUT_DEC(" kB\nLocked: ", 1134 mss->pss_locked >> PSS_SHIFT); 1135 seq_puts(m, " kB\n"); 1136 } 1137 1138 static int show_smap(struct seq_file *m, void *v) 1139 { 1140 struct vm_area_struct *vma = v; 1141 struct mem_size_stats mss = {}; 1142 1143 smap_gather_stats(vma, &mss, 0); 1144 1145 show_map_vma(m, vma); 1146 1147 SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start); 1148 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma)); 1149 SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma)); 1150 seq_puts(m, " kB\n"); 1151 1152 __show_smap(m, &mss, false); 1153 1154 seq_printf(m, "THPeligible: %8u\n", 1155 !!thp_vma_allowable_orders(vma, vma->vm_flags, 1156 TVA_SMAPS | TVA_ENFORCE_SYSFS, THP_ORDERS_ALL)); 1157 1158 if (arch_pkeys_enabled()) 1159 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); 1160 show_smap_vma_flags(m, vma); 1161 1162 return 0; 1163 } 1164 1165 static int show_smaps_rollup(struct seq_file *m, void *v) 1166 { 1167 struct proc_maps_private *priv = m->private; 1168 struct mem_size_stats mss = {}; 1169 struct mm_struct *mm = priv->mm; 1170 struct vm_area_struct *vma; 1171 unsigned long vma_start = 0, last_vma_end = 0; 1172 int ret = 0; 1173 VMA_ITERATOR(vmi, mm, 0); 1174 1175 priv->task = get_proc_task(priv->inode); 1176 if (!priv->task) 1177 return -ESRCH; 1178 1179 if (!mm || !mmget_not_zero(mm)) { 1180 ret = -ESRCH; 1181 goto out_put_task; 1182 } 1183 1184 ret = mmap_read_lock_killable(mm); 1185 if (ret) 1186 goto out_put_mm; 1187 1188 hold_task_mempolicy(priv); 1189 vma = vma_next(&vmi); 1190 1191 if (unlikely(!vma)) 1192 goto empty_set; 1193 1194 vma_start = vma->vm_start; 1195 do { 1196 smap_gather_stats(vma, &mss, 0); 1197 last_vma_end = vma->vm_end; 1198 1199 /* 1200 * Release mmap_lock temporarily if someone wants to 1201 * access it for write request. 1202 */ 1203 if (mmap_lock_is_contended(mm)) { 1204 vma_iter_invalidate(&vmi); 1205 mmap_read_unlock(mm); 1206 ret = mmap_read_lock_killable(mm); 1207 if (ret) { 1208 release_task_mempolicy(priv); 1209 goto out_put_mm; 1210 } 1211 1212 /* 1213 * After dropping the lock, there are four cases to 1214 * consider. See the following example for explanation. 1215 * 1216 * +------+------+-----------+ 1217 * | VMA1 | VMA2 | VMA3 | 1218 * +------+------+-----------+ 1219 * | | | | 1220 * 4k 8k 16k 400k 1221 * 1222 * Suppose we drop the lock after reading VMA2 due to 1223 * contention, then we get: 1224 * 1225 * last_vma_end = 16k 1226 * 1227 * 1) VMA2 is freed, but VMA3 exists: 1228 * 1229 * vma_next(vmi) will return VMA3. 1230 * In this case, just continue from VMA3. 1231 * 1232 * 2) VMA2 still exists: 1233 * 1234 * vma_next(vmi) will return VMA3. 1235 * In this case, just continue from VMA3. 1236 * 1237 * 3) No more VMAs can be found: 1238 * 1239 * vma_next(vmi) will return NULL. 1240 * No more things to do, just break. 1241 * 1242 * 4) (last_vma_end - 1) is the middle of a vma (VMA'): 1243 * 1244 * vma_next(vmi) will return VMA' whose range 1245 * contains last_vma_end. 1246 * Iterate VMA' from last_vma_end. 1247 */ 1248 vma = vma_next(&vmi); 1249 /* Case 3 above */ 1250 if (!vma) 1251 break; 1252 1253 /* Case 1 and 2 above */ 1254 if (vma->vm_start >= last_vma_end) { 1255 smap_gather_stats(vma, &mss, 0); 1256 last_vma_end = vma->vm_end; 1257 continue; 1258 } 1259 1260 /* Case 4 above */ 1261 if (vma->vm_end > last_vma_end) { 1262 smap_gather_stats(vma, &mss, last_vma_end); 1263 last_vma_end = vma->vm_end; 1264 } 1265 } 1266 } for_each_vma(vmi, vma); 1267 1268 empty_set: 1269 show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0); 1270 seq_pad(m, ' '); 1271 seq_puts(m, "[rollup]\n"); 1272 1273 __show_smap(m, &mss, true); 1274 1275 release_task_mempolicy(priv); 1276 mmap_read_unlock(mm); 1277 1278 out_put_mm: 1279 mmput(mm); 1280 out_put_task: 1281 put_task_struct(priv->task); 1282 priv->task = NULL; 1283 1284 return ret; 1285 } 1286 #undef SEQ_PUT_DEC 1287 1288 static const struct seq_operations proc_pid_smaps_op = { 1289 .start = m_start, 1290 .next = m_next, 1291 .stop = m_stop, 1292 .show = show_smap 1293 }; 1294 1295 static int pid_smaps_open(struct inode *inode, struct file *file) 1296 { 1297 return do_maps_open(inode, file, &proc_pid_smaps_op); 1298 } 1299 1300 static int smaps_rollup_open(struct inode *inode, struct file *file) 1301 { 1302 int ret; 1303 struct proc_maps_private *priv; 1304 1305 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT); 1306 if (!priv) 1307 return -ENOMEM; 1308 1309 ret = single_open(file, show_smaps_rollup, priv); 1310 if (ret) 1311 goto out_free; 1312 1313 priv->inode = inode; 1314 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 1315 if (IS_ERR(priv->mm)) { 1316 ret = PTR_ERR(priv->mm); 1317 1318 single_release(inode, file); 1319 goto out_free; 1320 } 1321 1322 return 0; 1323 1324 out_free: 1325 kfree(priv); 1326 return ret; 1327 } 1328 1329 static int smaps_rollup_release(struct inode *inode, struct file *file) 1330 { 1331 struct seq_file *seq = file->private_data; 1332 struct proc_maps_private *priv = seq->private; 1333 1334 if (priv->mm) 1335 mmdrop(priv->mm); 1336 1337 kfree(priv); 1338 return single_release(inode, file); 1339 } 1340 1341 const struct file_operations proc_pid_smaps_operations = { 1342 .open = pid_smaps_open, 1343 .read = seq_read, 1344 .llseek = seq_lseek, 1345 .release = proc_map_release, 1346 }; 1347 1348 const struct file_operations proc_pid_smaps_rollup_operations = { 1349 .open = smaps_rollup_open, 1350 .read = seq_read, 1351 .llseek = seq_lseek, 1352 .release = smaps_rollup_release, 1353 }; 1354 1355 enum clear_refs_types { 1356 CLEAR_REFS_ALL = 1, 1357 CLEAR_REFS_ANON, 1358 CLEAR_REFS_MAPPED, 1359 CLEAR_REFS_SOFT_DIRTY, 1360 CLEAR_REFS_MM_HIWATER_RSS, 1361 CLEAR_REFS_LAST, 1362 }; 1363 1364 struct clear_refs_private { 1365 enum clear_refs_types type; 1366 }; 1367 1368 #ifdef CONFIG_MEM_SOFT_DIRTY 1369 1370 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1371 { 1372 struct folio *folio; 1373 1374 if (!pte_write(pte)) 1375 return false; 1376 if (!is_cow_mapping(vma->vm_flags)) 1377 return false; 1378 if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))) 1379 return false; 1380 folio = vm_normal_folio(vma, addr, pte); 1381 if (!folio) 1382 return false; 1383 return folio_maybe_dma_pinned(folio); 1384 } 1385 1386 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1387 unsigned long addr, pte_t *pte) 1388 { 1389 /* 1390 * The soft-dirty tracker uses #PF-s to catch writes 1391 * to pages, so write-protect the pte as well. See the 1392 * Documentation/admin-guide/mm/soft-dirty.rst for full description 1393 * of how soft-dirty works. 1394 */ 1395 pte_t ptent = ptep_get(pte); 1396 1397 if (pte_present(ptent)) { 1398 pte_t old_pte; 1399 1400 if (pte_is_pinned(vma, addr, ptent)) 1401 return; 1402 old_pte = ptep_modify_prot_start(vma, addr, pte); 1403 ptent = pte_wrprotect(old_pte); 1404 ptent = pte_clear_soft_dirty(ptent); 1405 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 1406 } else if (is_swap_pte(ptent)) { 1407 ptent = pte_swp_clear_soft_dirty(ptent); 1408 set_pte_at(vma->vm_mm, addr, pte, ptent); 1409 } 1410 } 1411 #else 1412 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1413 unsigned long addr, pte_t *pte) 1414 { 1415 } 1416 #endif 1417 1418 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 1419 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1420 unsigned long addr, pmd_t *pmdp) 1421 { 1422 pmd_t old, pmd = *pmdp; 1423 1424 if (pmd_present(pmd)) { 1425 /* See comment in change_huge_pmd() */ 1426 old = pmdp_invalidate(vma, addr, pmdp); 1427 if (pmd_dirty(old)) 1428 pmd = pmd_mkdirty(pmd); 1429 if (pmd_young(old)) 1430 pmd = pmd_mkyoung(pmd); 1431 1432 pmd = pmd_wrprotect(pmd); 1433 pmd = pmd_clear_soft_dirty(pmd); 1434 1435 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1436 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 1437 pmd = pmd_swp_clear_soft_dirty(pmd); 1438 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1439 } 1440 } 1441 #else 1442 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1443 unsigned long addr, pmd_t *pmdp) 1444 { 1445 } 1446 #endif 1447 1448 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 1449 unsigned long end, struct mm_walk *walk) 1450 { 1451 struct clear_refs_private *cp = walk->private; 1452 struct vm_area_struct *vma = walk->vma; 1453 pte_t *pte, ptent; 1454 spinlock_t *ptl; 1455 struct folio *folio; 1456 1457 ptl = pmd_trans_huge_lock(pmd, vma); 1458 if (ptl) { 1459 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1460 clear_soft_dirty_pmd(vma, addr, pmd); 1461 goto out; 1462 } 1463 1464 if (!pmd_present(*pmd)) 1465 goto out; 1466 1467 folio = pmd_folio(*pmd); 1468 1469 /* Clear accessed and referenced bits. */ 1470 pmdp_test_and_clear_young(vma, addr, pmd); 1471 folio_test_clear_young(folio); 1472 folio_clear_referenced(folio); 1473 out: 1474 spin_unlock(ptl); 1475 return 0; 1476 } 1477 1478 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 1479 if (!pte) { 1480 walk->action = ACTION_AGAIN; 1481 return 0; 1482 } 1483 for (; addr != end; pte++, addr += PAGE_SIZE) { 1484 ptent = ptep_get(pte); 1485 1486 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1487 clear_soft_dirty(vma, addr, pte); 1488 continue; 1489 } 1490 1491 if (!pte_present(ptent)) 1492 continue; 1493 1494 folio = vm_normal_folio(vma, addr, ptent); 1495 if (!folio) 1496 continue; 1497 1498 /* Clear accessed and referenced bits. */ 1499 ptep_test_and_clear_young(vma, addr, pte); 1500 folio_test_clear_young(folio); 1501 folio_clear_referenced(folio); 1502 } 1503 pte_unmap_unlock(pte - 1, ptl); 1504 cond_resched(); 1505 return 0; 1506 } 1507 1508 static int clear_refs_test_walk(unsigned long start, unsigned long end, 1509 struct mm_walk *walk) 1510 { 1511 struct clear_refs_private *cp = walk->private; 1512 struct vm_area_struct *vma = walk->vma; 1513 1514 if (vma->vm_flags & VM_PFNMAP) 1515 return 1; 1516 1517 /* 1518 * Writing 1 to /proc/pid/clear_refs affects all pages. 1519 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. 1520 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. 1521 * Writing 4 to /proc/pid/clear_refs affects all pages. 1522 */ 1523 if (cp->type == CLEAR_REFS_ANON && vma->vm_file) 1524 return 1; 1525 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) 1526 return 1; 1527 return 0; 1528 } 1529 1530 static const struct mm_walk_ops clear_refs_walk_ops = { 1531 .pmd_entry = clear_refs_pte_range, 1532 .test_walk = clear_refs_test_walk, 1533 .walk_lock = PGWALK_WRLOCK, 1534 }; 1535 1536 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 1537 size_t count, loff_t *ppos) 1538 { 1539 struct task_struct *task; 1540 char buffer[PROC_NUMBUF] = {}; 1541 struct mm_struct *mm; 1542 struct vm_area_struct *vma; 1543 enum clear_refs_types type; 1544 int itype; 1545 int rv; 1546 1547 if (count > sizeof(buffer) - 1) 1548 count = sizeof(buffer) - 1; 1549 if (copy_from_user(buffer, buf, count)) 1550 return -EFAULT; 1551 rv = kstrtoint(strstrip(buffer), 10, &itype); 1552 if (rv < 0) 1553 return rv; 1554 type = (enum clear_refs_types)itype; 1555 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) 1556 return -EINVAL; 1557 1558 task = get_proc_task(file_inode(file)); 1559 if (!task) 1560 return -ESRCH; 1561 mm = get_task_mm(task); 1562 if (mm) { 1563 VMA_ITERATOR(vmi, mm, 0); 1564 struct mmu_notifier_range range; 1565 struct clear_refs_private cp = { 1566 .type = type, 1567 }; 1568 1569 if (mmap_write_lock_killable(mm)) { 1570 count = -EINTR; 1571 goto out_mm; 1572 } 1573 if (type == CLEAR_REFS_MM_HIWATER_RSS) { 1574 /* 1575 * Writing 5 to /proc/pid/clear_refs resets the peak 1576 * resident set size to this mm's current rss value. 1577 */ 1578 reset_mm_hiwater_rss(mm); 1579 goto out_unlock; 1580 } 1581 1582 if (type == CLEAR_REFS_SOFT_DIRTY) { 1583 for_each_vma(vmi, vma) { 1584 if (!(vma->vm_flags & VM_SOFTDIRTY)) 1585 continue; 1586 vm_flags_clear(vma, VM_SOFTDIRTY); 1587 vma_set_page_prot(vma); 1588 } 1589 1590 inc_tlb_flush_pending(mm); 1591 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 1592 0, mm, 0, -1UL); 1593 mmu_notifier_invalidate_range_start(&range); 1594 } 1595 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); 1596 if (type == CLEAR_REFS_SOFT_DIRTY) { 1597 mmu_notifier_invalidate_range_end(&range); 1598 flush_tlb_mm(mm); 1599 dec_tlb_flush_pending(mm); 1600 } 1601 out_unlock: 1602 mmap_write_unlock(mm); 1603 out_mm: 1604 mmput(mm); 1605 } 1606 put_task_struct(task); 1607 1608 return count; 1609 } 1610 1611 const struct file_operations proc_clear_refs_operations = { 1612 .write = clear_refs_write, 1613 .llseek = noop_llseek, 1614 }; 1615 1616 typedef struct { 1617 u64 pme; 1618 } pagemap_entry_t; 1619 1620 struct pagemapread { 1621 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */ 1622 pagemap_entry_t *buffer; 1623 bool show_pfn; 1624 }; 1625 1626 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 1627 #define PAGEMAP_WALK_MASK (PMD_MASK) 1628 1629 #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) 1630 #define PM_PFRAME_BITS 55 1631 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) 1632 #define PM_SOFT_DIRTY BIT_ULL(55) 1633 #define PM_MMAP_EXCLUSIVE BIT_ULL(56) 1634 #define PM_UFFD_WP BIT_ULL(57) 1635 #define PM_FILE BIT_ULL(61) 1636 #define PM_SWAP BIT_ULL(62) 1637 #define PM_PRESENT BIT_ULL(63) 1638 1639 #define PM_END_OF_BUFFER 1 1640 1641 static inline pagemap_entry_t make_pme(u64 frame, u64 flags) 1642 { 1643 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags }; 1644 } 1645 1646 static int add_to_pagemap(pagemap_entry_t *pme, struct pagemapread *pm) 1647 { 1648 pm->buffer[pm->pos++] = *pme; 1649 if (pm->pos >= pm->len) 1650 return PM_END_OF_BUFFER; 1651 return 0; 1652 } 1653 1654 static int pagemap_pte_hole(unsigned long start, unsigned long end, 1655 __always_unused int depth, struct mm_walk *walk) 1656 { 1657 struct pagemapread *pm = walk->private; 1658 unsigned long addr = start; 1659 int err = 0; 1660 1661 while (addr < end) { 1662 struct vm_area_struct *vma = find_vma(walk->mm, addr); 1663 pagemap_entry_t pme = make_pme(0, 0); 1664 /* End of address space hole, which we mark as non-present. */ 1665 unsigned long hole_end; 1666 1667 if (vma) 1668 hole_end = min(end, vma->vm_start); 1669 else 1670 hole_end = end; 1671 1672 for (; addr < hole_end; addr += PAGE_SIZE) { 1673 err = add_to_pagemap(&pme, pm); 1674 if (err) 1675 goto out; 1676 } 1677 1678 if (!vma) 1679 break; 1680 1681 /* Addresses in the VMA. */ 1682 if (vma->vm_flags & VM_SOFTDIRTY) 1683 pme = make_pme(0, PM_SOFT_DIRTY); 1684 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { 1685 err = add_to_pagemap(&pme, pm); 1686 if (err) 1687 goto out; 1688 } 1689 } 1690 out: 1691 return err; 1692 } 1693 1694 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 1695 struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1696 { 1697 u64 frame = 0, flags = 0; 1698 struct page *page = NULL; 1699 struct folio *folio; 1700 1701 if (pte_present(pte)) { 1702 if (pm->show_pfn) 1703 frame = pte_pfn(pte); 1704 flags |= PM_PRESENT; 1705 page = vm_normal_page(vma, addr, pte); 1706 if (pte_soft_dirty(pte)) 1707 flags |= PM_SOFT_DIRTY; 1708 if (pte_uffd_wp(pte)) 1709 flags |= PM_UFFD_WP; 1710 } else if (is_swap_pte(pte)) { 1711 swp_entry_t entry; 1712 if (pte_swp_soft_dirty(pte)) 1713 flags |= PM_SOFT_DIRTY; 1714 if (pte_swp_uffd_wp(pte)) 1715 flags |= PM_UFFD_WP; 1716 entry = pte_to_swp_entry(pte); 1717 if (pm->show_pfn) { 1718 pgoff_t offset; 1719 /* 1720 * For PFN swap offsets, keeping the offset field 1721 * to be PFN only to be compatible with old smaps. 1722 */ 1723 if (is_pfn_swap_entry(entry)) 1724 offset = swp_offset_pfn(entry); 1725 else 1726 offset = swp_offset(entry); 1727 frame = swp_type(entry) | 1728 (offset << MAX_SWAPFILES_SHIFT); 1729 } 1730 flags |= PM_SWAP; 1731 if (is_pfn_swap_entry(entry)) 1732 page = pfn_swap_entry_to_page(entry); 1733 if (pte_marker_entry_uffd_wp(entry)) 1734 flags |= PM_UFFD_WP; 1735 } 1736 1737 if (page) { 1738 folio = page_folio(page); 1739 if (!folio_test_anon(folio)) 1740 flags |= PM_FILE; 1741 if ((flags & PM_PRESENT) && 1742 folio_precise_page_mapcount(folio, page) == 1) 1743 flags |= PM_MMAP_EXCLUSIVE; 1744 } 1745 if (vma->vm_flags & VM_SOFTDIRTY) 1746 flags |= PM_SOFT_DIRTY; 1747 1748 return make_pme(frame, flags); 1749 } 1750 1751 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, 1752 struct mm_walk *walk) 1753 { 1754 struct vm_area_struct *vma = walk->vma; 1755 struct pagemapread *pm = walk->private; 1756 spinlock_t *ptl; 1757 pte_t *pte, *orig_pte; 1758 int err = 0; 1759 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1760 1761 ptl = pmd_trans_huge_lock(pmdp, vma); 1762 if (ptl) { 1763 unsigned int idx = (addr & ~PMD_MASK) >> PAGE_SHIFT; 1764 u64 flags = 0, frame = 0; 1765 pmd_t pmd = *pmdp; 1766 struct page *page = NULL; 1767 struct folio *folio = NULL; 1768 1769 if (vma->vm_flags & VM_SOFTDIRTY) 1770 flags |= PM_SOFT_DIRTY; 1771 1772 if (pmd_present(pmd)) { 1773 page = pmd_page(pmd); 1774 1775 flags |= PM_PRESENT; 1776 if (pmd_soft_dirty(pmd)) 1777 flags |= PM_SOFT_DIRTY; 1778 if (pmd_uffd_wp(pmd)) 1779 flags |= PM_UFFD_WP; 1780 if (pm->show_pfn) 1781 frame = pmd_pfn(pmd) + idx; 1782 } 1783 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1784 else if (is_swap_pmd(pmd)) { 1785 swp_entry_t entry = pmd_to_swp_entry(pmd); 1786 unsigned long offset; 1787 1788 if (pm->show_pfn) { 1789 if (is_pfn_swap_entry(entry)) 1790 offset = swp_offset_pfn(entry) + idx; 1791 else 1792 offset = swp_offset(entry) + idx; 1793 frame = swp_type(entry) | 1794 (offset << MAX_SWAPFILES_SHIFT); 1795 } 1796 flags |= PM_SWAP; 1797 if (pmd_swp_soft_dirty(pmd)) 1798 flags |= PM_SOFT_DIRTY; 1799 if (pmd_swp_uffd_wp(pmd)) 1800 flags |= PM_UFFD_WP; 1801 VM_BUG_ON(!is_pmd_migration_entry(pmd)); 1802 page = pfn_swap_entry_to_page(entry); 1803 } 1804 #endif 1805 1806 if (page) { 1807 folio = page_folio(page); 1808 if (!folio_test_anon(folio)) 1809 flags |= PM_FILE; 1810 } 1811 1812 for (; addr != end; addr += PAGE_SIZE, idx++) { 1813 unsigned long cur_flags = flags; 1814 pagemap_entry_t pme; 1815 1816 if (folio && (flags & PM_PRESENT) && 1817 folio_precise_page_mapcount(folio, page + idx) == 1) 1818 cur_flags |= PM_MMAP_EXCLUSIVE; 1819 1820 pme = make_pme(frame, cur_flags); 1821 err = add_to_pagemap(&pme, pm); 1822 if (err) 1823 break; 1824 if (pm->show_pfn) { 1825 if (flags & PM_PRESENT) 1826 frame++; 1827 else if (flags & PM_SWAP) 1828 frame += (1 << MAX_SWAPFILES_SHIFT); 1829 } 1830 } 1831 spin_unlock(ptl); 1832 return err; 1833 } 1834 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1835 1836 /* 1837 * We can assume that @vma always points to a valid one and @end never 1838 * goes beyond vma->vm_end. 1839 */ 1840 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); 1841 if (!pte) { 1842 walk->action = ACTION_AGAIN; 1843 return err; 1844 } 1845 for (; addr < end; pte++, addr += PAGE_SIZE) { 1846 pagemap_entry_t pme; 1847 1848 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte)); 1849 err = add_to_pagemap(&pme, pm); 1850 if (err) 1851 break; 1852 } 1853 pte_unmap_unlock(orig_pte, ptl); 1854 1855 cond_resched(); 1856 1857 return err; 1858 } 1859 1860 #ifdef CONFIG_HUGETLB_PAGE 1861 /* This function walks within one hugetlb entry in the single call */ 1862 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 1863 unsigned long addr, unsigned long end, 1864 struct mm_walk *walk) 1865 { 1866 struct pagemapread *pm = walk->private; 1867 struct vm_area_struct *vma = walk->vma; 1868 u64 flags = 0, frame = 0; 1869 int err = 0; 1870 pte_t pte; 1871 1872 if (vma->vm_flags & VM_SOFTDIRTY) 1873 flags |= PM_SOFT_DIRTY; 1874 1875 pte = huge_ptep_get(walk->mm, addr, ptep); 1876 if (pte_present(pte)) { 1877 struct folio *folio = page_folio(pte_page(pte)); 1878 1879 if (!folio_test_anon(folio)) 1880 flags |= PM_FILE; 1881 1882 if (!folio_likely_mapped_shared(folio) && 1883 !hugetlb_pmd_shared(ptep)) 1884 flags |= PM_MMAP_EXCLUSIVE; 1885 1886 if (huge_pte_uffd_wp(pte)) 1887 flags |= PM_UFFD_WP; 1888 1889 flags |= PM_PRESENT; 1890 if (pm->show_pfn) 1891 frame = pte_pfn(pte) + 1892 ((addr & ~hmask) >> PAGE_SHIFT); 1893 } else if (pte_swp_uffd_wp_any(pte)) { 1894 flags |= PM_UFFD_WP; 1895 } 1896 1897 for (; addr != end; addr += PAGE_SIZE) { 1898 pagemap_entry_t pme = make_pme(frame, flags); 1899 1900 err = add_to_pagemap(&pme, pm); 1901 if (err) 1902 return err; 1903 if (pm->show_pfn && (flags & PM_PRESENT)) 1904 frame++; 1905 } 1906 1907 cond_resched(); 1908 1909 return err; 1910 } 1911 #else 1912 #define pagemap_hugetlb_range NULL 1913 #endif /* HUGETLB_PAGE */ 1914 1915 static const struct mm_walk_ops pagemap_ops = { 1916 .pmd_entry = pagemap_pmd_range, 1917 .pte_hole = pagemap_pte_hole, 1918 .hugetlb_entry = pagemap_hugetlb_range, 1919 .walk_lock = PGWALK_RDLOCK, 1920 }; 1921 1922 /* 1923 * /proc/pid/pagemap - an array mapping virtual pages to pfns 1924 * 1925 * For each page in the address space, this file contains one 64-bit entry 1926 * consisting of the following: 1927 * 1928 * Bits 0-54 page frame number (PFN) if present 1929 * Bits 0-4 swap type if swapped 1930 * Bits 5-54 swap offset if swapped 1931 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) 1932 * Bit 56 page exclusively mapped 1933 * Bit 57 pte is uffd-wp write-protected 1934 * Bits 58-60 zero 1935 * Bit 61 page is file-page or shared-anon 1936 * Bit 62 page swapped 1937 * Bit 63 page present 1938 * 1939 * If the page is not present but in swap, then the PFN contains an 1940 * encoding of the swap file number and the page's offset into the 1941 * swap. Unmapped pages return a null PFN. This allows determining 1942 * precisely which pages are mapped (or in swap) and comparing mapped 1943 * pages between processes. 1944 * 1945 * Efficient users of this interface will use /proc/pid/maps to 1946 * determine which areas of memory are actually mapped and llseek to 1947 * skip over unmapped regions. 1948 */ 1949 static ssize_t pagemap_read(struct file *file, char __user *buf, 1950 size_t count, loff_t *ppos) 1951 { 1952 struct mm_struct *mm = file->private_data; 1953 struct pagemapread pm; 1954 unsigned long src; 1955 unsigned long svpfn; 1956 unsigned long start_vaddr; 1957 unsigned long end_vaddr; 1958 int ret = 0, copied = 0; 1959 1960 if (!mm || !mmget_not_zero(mm)) 1961 goto out; 1962 1963 ret = -EINVAL; 1964 /* file position must be aligned */ 1965 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 1966 goto out_mm; 1967 1968 ret = 0; 1969 if (!count) 1970 goto out_mm; 1971 1972 /* do not disclose physical addresses: attack vector */ 1973 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); 1974 1975 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 1976 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); 1977 ret = -ENOMEM; 1978 if (!pm.buffer) 1979 goto out_mm; 1980 1981 src = *ppos; 1982 svpfn = src / PM_ENTRY_BYTES; 1983 end_vaddr = mm->task_size; 1984 1985 /* watch out for wraparound */ 1986 start_vaddr = end_vaddr; 1987 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) { 1988 unsigned long end; 1989 1990 ret = mmap_read_lock_killable(mm); 1991 if (ret) 1992 goto out_free; 1993 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT); 1994 mmap_read_unlock(mm); 1995 1996 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT); 1997 if (end >= start_vaddr && end < mm->task_size) 1998 end_vaddr = end; 1999 } 2000 2001 /* Ensure the address is inside the task */ 2002 if (start_vaddr > mm->task_size) 2003 start_vaddr = end_vaddr; 2004 2005 ret = 0; 2006 while (count && (start_vaddr < end_vaddr)) { 2007 int len; 2008 unsigned long end; 2009 2010 pm.pos = 0; 2011 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 2012 /* overflow ? */ 2013 if (end < start_vaddr || end > end_vaddr) 2014 end = end_vaddr; 2015 ret = mmap_read_lock_killable(mm); 2016 if (ret) 2017 goto out_free; 2018 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm); 2019 mmap_read_unlock(mm); 2020 start_vaddr = end; 2021 2022 len = min(count, PM_ENTRY_BYTES * pm.pos); 2023 if (copy_to_user(buf, pm.buffer, len)) { 2024 ret = -EFAULT; 2025 goto out_free; 2026 } 2027 copied += len; 2028 buf += len; 2029 count -= len; 2030 } 2031 *ppos += copied; 2032 if (!ret || ret == PM_END_OF_BUFFER) 2033 ret = copied; 2034 2035 out_free: 2036 kfree(pm.buffer); 2037 out_mm: 2038 mmput(mm); 2039 out: 2040 return ret; 2041 } 2042 2043 static int pagemap_open(struct inode *inode, struct file *file) 2044 { 2045 struct mm_struct *mm; 2046 2047 mm = proc_mem_open(inode, PTRACE_MODE_READ); 2048 if (IS_ERR(mm)) 2049 return PTR_ERR(mm); 2050 file->private_data = mm; 2051 return 0; 2052 } 2053 2054 static int pagemap_release(struct inode *inode, struct file *file) 2055 { 2056 struct mm_struct *mm = file->private_data; 2057 2058 if (mm) 2059 mmdrop(mm); 2060 return 0; 2061 } 2062 2063 #define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \ 2064 PAGE_IS_FILE | PAGE_IS_PRESENT | \ 2065 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \ 2066 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY) 2067 #define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC) 2068 2069 struct pagemap_scan_private { 2070 struct pm_scan_arg arg; 2071 unsigned long masks_of_interest, cur_vma_category; 2072 struct page_region *vec_buf; 2073 unsigned long vec_buf_len, vec_buf_index, found_pages; 2074 struct page_region __user *vec_out; 2075 }; 2076 2077 static unsigned long pagemap_page_category(struct pagemap_scan_private *p, 2078 struct vm_area_struct *vma, 2079 unsigned long addr, pte_t pte) 2080 { 2081 unsigned long categories = 0; 2082 2083 if (pte_present(pte)) { 2084 struct page *page; 2085 2086 categories |= PAGE_IS_PRESENT; 2087 if (!pte_uffd_wp(pte)) 2088 categories |= PAGE_IS_WRITTEN; 2089 2090 if (p->masks_of_interest & PAGE_IS_FILE) { 2091 page = vm_normal_page(vma, addr, pte); 2092 if (page && !PageAnon(page)) 2093 categories |= PAGE_IS_FILE; 2094 } 2095 2096 if (is_zero_pfn(pte_pfn(pte))) 2097 categories |= PAGE_IS_PFNZERO; 2098 if (pte_soft_dirty(pte)) 2099 categories |= PAGE_IS_SOFT_DIRTY; 2100 } else if (is_swap_pte(pte)) { 2101 swp_entry_t swp; 2102 2103 categories |= PAGE_IS_SWAPPED; 2104 if (!pte_swp_uffd_wp_any(pte)) 2105 categories |= PAGE_IS_WRITTEN; 2106 2107 if (p->masks_of_interest & PAGE_IS_FILE) { 2108 swp = pte_to_swp_entry(pte); 2109 if (is_pfn_swap_entry(swp) && 2110 !folio_test_anon(pfn_swap_entry_folio(swp))) 2111 categories |= PAGE_IS_FILE; 2112 } 2113 if (pte_swp_soft_dirty(pte)) 2114 categories |= PAGE_IS_SOFT_DIRTY; 2115 } 2116 2117 return categories; 2118 } 2119 2120 static void make_uffd_wp_pte(struct vm_area_struct *vma, 2121 unsigned long addr, pte_t *pte, pte_t ptent) 2122 { 2123 if (pte_present(ptent)) { 2124 pte_t old_pte; 2125 2126 old_pte = ptep_modify_prot_start(vma, addr, pte); 2127 ptent = pte_mkuffd_wp(old_pte); 2128 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 2129 } else if (is_swap_pte(ptent)) { 2130 ptent = pte_swp_mkuffd_wp(ptent); 2131 set_pte_at(vma->vm_mm, addr, pte, ptent); 2132 } else { 2133 set_pte_at(vma->vm_mm, addr, pte, 2134 make_pte_marker(PTE_MARKER_UFFD_WP)); 2135 } 2136 } 2137 2138 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2139 static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, 2140 struct vm_area_struct *vma, 2141 unsigned long addr, pmd_t pmd) 2142 { 2143 unsigned long categories = PAGE_IS_HUGE; 2144 2145 if (pmd_present(pmd)) { 2146 struct page *page; 2147 2148 categories |= PAGE_IS_PRESENT; 2149 if (!pmd_uffd_wp(pmd)) 2150 categories |= PAGE_IS_WRITTEN; 2151 2152 if (p->masks_of_interest & PAGE_IS_FILE) { 2153 page = vm_normal_page_pmd(vma, addr, pmd); 2154 if (page && !PageAnon(page)) 2155 categories |= PAGE_IS_FILE; 2156 } 2157 2158 if (is_zero_pfn(pmd_pfn(pmd))) 2159 categories |= PAGE_IS_PFNZERO; 2160 if (pmd_soft_dirty(pmd)) 2161 categories |= PAGE_IS_SOFT_DIRTY; 2162 } else if (is_swap_pmd(pmd)) { 2163 swp_entry_t swp; 2164 2165 categories |= PAGE_IS_SWAPPED; 2166 if (!pmd_swp_uffd_wp(pmd)) 2167 categories |= PAGE_IS_WRITTEN; 2168 if (pmd_swp_soft_dirty(pmd)) 2169 categories |= PAGE_IS_SOFT_DIRTY; 2170 2171 if (p->masks_of_interest & PAGE_IS_FILE) { 2172 swp = pmd_to_swp_entry(pmd); 2173 if (is_pfn_swap_entry(swp) && 2174 !folio_test_anon(pfn_swap_entry_folio(swp))) 2175 categories |= PAGE_IS_FILE; 2176 } 2177 } 2178 2179 return categories; 2180 } 2181 2182 static void make_uffd_wp_pmd(struct vm_area_struct *vma, 2183 unsigned long addr, pmd_t *pmdp) 2184 { 2185 pmd_t old, pmd = *pmdp; 2186 2187 if (pmd_present(pmd)) { 2188 old = pmdp_invalidate_ad(vma, addr, pmdp); 2189 pmd = pmd_mkuffd_wp(old); 2190 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 2191 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 2192 pmd = pmd_swp_mkuffd_wp(pmd); 2193 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 2194 } 2195 } 2196 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 2197 2198 #ifdef CONFIG_HUGETLB_PAGE 2199 static unsigned long pagemap_hugetlb_category(pte_t pte) 2200 { 2201 unsigned long categories = PAGE_IS_HUGE; 2202 2203 /* 2204 * According to pagemap_hugetlb_range(), file-backed HugeTLB 2205 * page cannot be swapped. So PAGE_IS_FILE is not checked for 2206 * swapped pages. 2207 */ 2208 if (pte_present(pte)) { 2209 categories |= PAGE_IS_PRESENT; 2210 if (!huge_pte_uffd_wp(pte)) 2211 categories |= PAGE_IS_WRITTEN; 2212 if (!PageAnon(pte_page(pte))) 2213 categories |= PAGE_IS_FILE; 2214 if (is_zero_pfn(pte_pfn(pte))) 2215 categories |= PAGE_IS_PFNZERO; 2216 if (pte_soft_dirty(pte)) 2217 categories |= PAGE_IS_SOFT_DIRTY; 2218 } else if (is_swap_pte(pte)) { 2219 categories |= PAGE_IS_SWAPPED; 2220 if (!pte_swp_uffd_wp_any(pte)) 2221 categories |= PAGE_IS_WRITTEN; 2222 if (pte_swp_soft_dirty(pte)) 2223 categories |= PAGE_IS_SOFT_DIRTY; 2224 } 2225 2226 return categories; 2227 } 2228 2229 static void make_uffd_wp_huge_pte(struct vm_area_struct *vma, 2230 unsigned long addr, pte_t *ptep, 2231 pte_t ptent) 2232 { 2233 unsigned long psize; 2234 2235 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) 2236 return; 2237 2238 psize = huge_page_size(hstate_vma(vma)); 2239 2240 if (is_hugetlb_entry_migration(ptent)) 2241 set_huge_pte_at(vma->vm_mm, addr, ptep, 2242 pte_swp_mkuffd_wp(ptent), psize); 2243 else if (!huge_pte_none(ptent)) 2244 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, 2245 huge_pte_mkuffd_wp(ptent)); 2246 else 2247 set_huge_pte_at(vma->vm_mm, addr, ptep, 2248 make_pte_marker(PTE_MARKER_UFFD_WP), psize); 2249 } 2250 #endif /* CONFIG_HUGETLB_PAGE */ 2251 2252 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) 2253 static void pagemap_scan_backout_range(struct pagemap_scan_private *p, 2254 unsigned long addr, unsigned long end) 2255 { 2256 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2257 2258 if (cur_buf->start != addr) 2259 cur_buf->end = addr; 2260 else 2261 cur_buf->start = cur_buf->end = 0; 2262 2263 p->found_pages -= (end - addr) / PAGE_SIZE; 2264 } 2265 #endif 2266 2267 static bool pagemap_scan_is_interesting_page(unsigned long categories, 2268 const struct pagemap_scan_private *p) 2269 { 2270 categories ^= p->arg.category_inverted; 2271 if ((categories & p->arg.category_mask) != p->arg.category_mask) 2272 return false; 2273 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask)) 2274 return false; 2275 2276 return true; 2277 } 2278 2279 static bool pagemap_scan_is_interesting_vma(unsigned long categories, 2280 const struct pagemap_scan_private *p) 2281 { 2282 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED; 2283 2284 categories ^= p->arg.category_inverted; 2285 if ((categories & required) != required) 2286 return false; 2287 2288 return true; 2289 } 2290 2291 static int pagemap_scan_test_walk(unsigned long start, unsigned long end, 2292 struct mm_walk *walk) 2293 { 2294 struct pagemap_scan_private *p = walk->private; 2295 struct vm_area_struct *vma = walk->vma; 2296 unsigned long vma_category = 0; 2297 bool wp_allowed = userfaultfd_wp_async(vma) && 2298 userfaultfd_wp_use_markers(vma); 2299 2300 if (!wp_allowed) { 2301 /* User requested explicit failure over wp-async capability */ 2302 if (p->arg.flags & PM_SCAN_CHECK_WPASYNC) 2303 return -EPERM; 2304 /* 2305 * User requires wr-protect, and allows silently skipping 2306 * unsupported vmas. 2307 */ 2308 if (p->arg.flags & PM_SCAN_WP_MATCHING) 2309 return 1; 2310 /* 2311 * Then the request doesn't involve wr-protects at all, 2312 * fall through to the rest checks, and allow vma walk. 2313 */ 2314 } 2315 2316 if (vma->vm_flags & VM_PFNMAP) 2317 return 1; 2318 2319 if (wp_allowed) 2320 vma_category |= PAGE_IS_WPALLOWED; 2321 2322 if (vma->vm_flags & VM_SOFTDIRTY) 2323 vma_category |= PAGE_IS_SOFT_DIRTY; 2324 2325 if (!pagemap_scan_is_interesting_vma(vma_category, p)) 2326 return 1; 2327 2328 p->cur_vma_category = vma_category; 2329 2330 return 0; 2331 } 2332 2333 static bool pagemap_scan_push_range(unsigned long categories, 2334 struct pagemap_scan_private *p, 2335 unsigned long addr, unsigned long end) 2336 { 2337 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2338 2339 /* 2340 * When there is no output buffer provided at all, the sentinel values 2341 * won't match here. There is no other way for `cur_buf->end` to be 2342 * non-zero other than it being non-empty. 2343 */ 2344 if (addr == cur_buf->end && categories == cur_buf->categories) { 2345 cur_buf->end = end; 2346 return true; 2347 } 2348 2349 if (cur_buf->end) { 2350 if (p->vec_buf_index >= p->vec_buf_len - 1) 2351 return false; 2352 2353 cur_buf = &p->vec_buf[++p->vec_buf_index]; 2354 } 2355 2356 cur_buf->start = addr; 2357 cur_buf->end = end; 2358 cur_buf->categories = categories; 2359 2360 return true; 2361 } 2362 2363 static int pagemap_scan_output(unsigned long categories, 2364 struct pagemap_scan_private *p, 2365 unsigned long addr, unsigned long *end) 2366 { 2367 unsigned long n_pages, total_pages; 2368 int ret = 0; 2369 2370 if (!p->vec_buf) 2371 return 0; 2372 2373 categories &= p->arg.return_mask; 2374 2375 n_pages = (*end - addr) / PAGE_SIZE; 2376 if (check_add_overflow(p->found_pages, n_pages, &total_pages) || 2377 total_pages > p->arg.max_pages) { 2378 size_t n_too_much = total_pages - p->arg.max_pages; 2379 *end -= n_too_much * PAGE_SIZE; 2380 n_pages -= n_too_much; 2381 ret = -ENOSPC; 2382 } 2383 2384 if (!pagemap_scan_push_range(categories, p, addr, *end)) { 2385 *end = addr; 2386 n_pages = 0; 2387 ret = -ENOSPC; 2388 } 2389 2390 p->found_pages += n_pages; 2391 if (ret) 2392 p->arg.walk_end = *end; 2393 2394 return ret; 2395 } 2396 2397 static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start, 2398 unsigned long end, struct mm_walk *walk) 2399 { 2400 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2401 struct pagemap_scan_private *p = walk->private; 2402 struct vm_area_struct *vma = walk->vma; 2403 unsigned long categories; 2404 spinlock_t *ptl; 2405 int ret = 0; 2406 2407 ptl = pmd_trans_huge_lock(pmd, vma); 2408 if (!ptl) 2409 return -ENOENT; 2410 2411 categories = p->cur_vma_category | 2412 pagemap_thp_category(p, vma, start, *pmd); 2413 2414 if (!pagemap_scan_is_interesting_page(categories, p)) 2415 goto out_unlock; 2416 2417 ret = pagemap_scan_output(categories, p, start, &end); 2418 if (start == end) 2419 goto out_unlock; 2420 2421 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2422 goto out_unlock; 2423 if (~categories & PAGE_IS_WRITTEN) 2424 goto out_unlock; 2425 2426 /* 2427 * Break huge page into small pages if the WP operation 2428 * needs to be performed on a portion of the huge page. 2429 */ 2430 if (end != start + HPAGE_SIZE) { 2431 spin_unlock(ptl); 2432 split_huge_pmd(vma, pmd, start); 2433 pagemap_scan_backout_range(p, start, end); 2434 /* Report as if there was no THP */ 2435 return -ENOENT; 2436 } 2437 2438 make_uffd_wp_pmd(vma, start, pmd); 2439 flush_tlb_range(vma, start, end); 2440 out_unlock: 2441 spin_unlock(ptl); 2442 return ret; 2443 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 2444 return -ENOENT; 2445 #endif 2446 } 2447 2448 static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, 2449 unsigned long end, struct mm_walk *walk) 2450 { 2451 struct pagemap_scan_private *p = walk->private; 2452 struct vm_area_struct *vma = walk->vma; 2453 unsigned long addr, flush_end = 0; 2454 pte_t *pte, *start_pte; 2455 spinlock_t *ptl; 2456 int ret; 2457 2458 arch_enter_lazy_mmu_mode(); 2459 2460 ret = pagemap_scan_thp_entry(pmd, start, end, walk); 2461 if (ret != -ENOENT) { 2462 arch_leave_lazy_mmu_mode(); 2463 return ret; 2464 } 2465 2466 ret = 0; 2467 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); 2468 if (!pte) { 2469 arch_leave_lazy_mmu_mode(); 2470 walk->action = ACTION_AGAIN; 2471 return 0; 2472 } 2473 2474 if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { 2475 /* Fast path for performing exclusive WP */ 2476 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2477 pte_t ptent = ptep_get(pte); 2478 2479 if ((pte_present(ptent) && pte_uffd_wp(ptent)) || 2480 pte_swp_uffd_wp_any(ptent)) 2481 continue; 2482 make_uffd_wp_pte(vma, addr, pte, ptent); 2483 if (!flush_end) 2484 start = addr; 2485 flush_end = addr + PAGE_SIZE; 2486 } 2487 goto flush_and_return; 2488 } 2489 2490 if (!p->arg.category_anyof_mask && !p->arg.category_inverted && 2491 p->arg.category_mask == PAGE_IS_WRITTEN && 2492 p->arg.return_mask == PAGE_IS_WRITTEN) { 2493 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) { 2494 unsigned long next = addr + PAGE_SIZE; 2495 pte_t ptent = ptep_get(pte); 2496 2497 if ((pte_present(ptent) && pte_uffd_wp(ptent)) || 2498 pte_swp_uffd_wp_any(ptent)) 2499 continue; 2500 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN, 2501 p, addr, &next); 2502 if (next == addr) 2503 break; 2504 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2505 continue; 2506 make_uffd_wp_pte(vma, addr, pte, ptent); 2507 if (!flush_end) 2508 start = addr; 2509 flush_end = next; 2510 } 2511 goto flush_and_return; 2512 } 2513 2514 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2515 pte_t ptent = ptep_get(pte); 2516 unsigned long categories = p->cur_vma_category | 2517 pagemap_page_category(p, vma, addr, ptent); 2518 unsigned long next = addr + PAGE_SIZE; 2519 2520 if (!pagemap_scan_is_interesting_page(categories, p)) 2521 continue; 2522 2523 ret = pagemap_scan_output(categories, p, addr, &next); 2524 if (next == addr) 2525 break; 2526 2527 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2528 continue; 2529 if (~categories & PAGE_IS_WRITTEN) 2530 continue; 2531 2532 make_uffd_wp_pte(vma, addr, pte, ptent); 2533 if (!flush_end) 2534 start = addr; 2535 flush_end = next; 2536 } 2537 2538 flush_and_return: 2539 if (flush_end) 2540 flush_tlb_range(vma, start, addr); 2541 2542 pte_unmap_unlock(start_pte, ptl); 2543 arch_leave_lazy_mmu_mode(); 2544 2545 cond_resched(); 2546 return ret; 2547 } 2548 2549 #ifdef CONFIG_HUGETLB_PAGE 2550 static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, 2551 unsigned long start, unsigned long end, 2552 struct mm_walk *walk) 2553 { 2554 struct pagemap_scan_private *p = walk->private; 2555 struct vm_area_struct *vma = walk->vma; 2556 unsigned long categories; 2557 spinlock_t *ptl; 2558 int ret = 0; 2559 pte_t pte; 2560 2561 if (~p->arg.flags & PM_SCAN_WP_MATCHING) { 2562 /* Go the short route when not write-protecting pages. */ 2563 2564 pte = huge_ptep_get(walk->mm, start, ptep); 2565 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2566 2567 if (!pagemap_scan_is_interesting_page(categories, p)) 2568 return 0; 2569 2570 return pagemap_scan_output(categories, p, start, &end); 2571 } 2572 2573 i_mmap_lock_write(vma->vm_file->f_mapping); 2574 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep); 2575 2576 pte = huge_ptep_get(walk->mm, start, ptep); 2577 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2578 2579 if (!pagemap_scan_is_interesting_page(categories, p)) 2580 goto out_unlock; 2581 2582 ret = pagemap_scan_output(categories, p, start, &end); 2583 if (start == end) 2584 goto out_unlock; 2585 2586 if (~categories & PAGE_IS_WRITTEN) 2587 goto out_unlock; 2588 2589 if (end != start + HPAGE_SIZE) { 2590 /* Partial HugeTLB page WP isn't possible. */ 2591 pagemap_scan_backout_range(p, start, end); 2592 p->arg.walk_end = start; 2593 ret = 0; 2594 goto out_unlock; 2595 } 2596 2597 make_uffd_wp_huge_pte(vma, start, ptep, pte); 2598 flush_hugetlb_tlb_range(vma, start, end); 2599 2600 out_unlock: 2601 spin_unlock(ptl); 2602 i_mmap_unlock_write(vma->vm_file->f_mapping); 2603 2604 return ret; 2605 } 2606 #else 2607 #define pagemap_scan_hugetlb_entry NULL 2608 #endif 2609 2610 static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, 2611 int depth, struct mm_walk *walk) 2612 { 2613 struct pagemap_scan_private *p = walk->private; 2614 struct vm_area_struct *vma = walk->vma; 2615 int ret, err; 2616 2617 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p)) 2618 return 0; 2619 2620 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end); 2621 if (addr == end) 2622 return ret; 2623 2624 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2625 return ret; 2626 2627 err = uffd_wp_range(vma, addr, end - addr, true); 2628 if (err < 0) 2629 ret = err; 2630 2631 return ret; 2632 } 2633 2634 static const struct mm_walk_ops pagemap_scan_ops = { 2635 .test_walk = pagemap_scan_test_walk, 2636 .pmd_entry = pagemap_scan_pmd_entry, 2637 .pte_hole = pagemap_scan_pte_hole, 2638 .hugetlb_entry = pagemap_scan_hugetlb_entry, 2639 }; 2640 2641 static int pagemap_scan_get_args(struct pm_scan_arg *arg, 2642 unsigned long uarg) 2643 { 2644 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg))) 2645 return -EFAULT; 2646 2647 if (arg->size != sizeof(struct pm_scan_arg)) 2648 return -EINVAL; 2649 2650 /* Validate requested features */ 2651 if (arg->flags & ~PM_SCAN_FLAGS) 2652 return -EINVAL; 2653 if ((arg->category_inverted | arg->category_mask | 2654 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) 2655 return -EINVAL; 2656 2657 arg->start = untagged_addr((unsigned long)arg->start); 2658 arg->end = untagged_addr((unsigned long)arg->end); 2659 arg->vec = untagged_addr((unsigned long)arg->vec); 2660 2661 /* Validate memory pointers */ 2662 if (!IS_ALIGNED(arg->start, PAGE_SIZE)) 2663 return -EINVAL; 2664 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start)) 2665 return -EFAULT; 2666 if (!arg->vec && arg->vec_len) 2667 return -EINVAL; 2668 if (UINT_MAX == SIZE_MAX && arg->vec_len > SIZE_MAX) 2669 return -EINVAL; 2670 if (arg->vec && !access_ok((void __user *)(long)arg->vec, 2671 size_mul(arg->vec_len, sizeof(struct page_region)))) 2672 return -EFAULT; 2673 2674 /* Fixup default values */ 2675 arg->end = ALIGN(arg->end, PAGE_SIZE); 2676 arg->walk_end = 0; 2677 if (!arg->max_pages) 2678 arg->max_pages = ULONG_MAX; 2679 2680 return 0; 2681 } 2682 2683 static int pagemap_scan_writeback_args(struct pm_scan_arg *arg, 2684 unsigned long uargl) 2685 { 2686 struct pm_scan_arg __user *uarg = (void __user *)uargl; 2687 2688 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end))) 2689 return -EFAULT; 2690 2691 return 0; 2692 } 2693 2694 static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p) 2695 { 2696 if (!p->arg.vec_len) 2697 return 0; 2698 2699 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT, 2700 p->arg.vec_len); 2701 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf), 2702 GFP_KERNEL); 2703 if (!p->vec_buf) 2704 return -ENOMEM; 2705 2706 p->vec_buf->start = p->vec_buf->end = 0; 2707 p->vec_out = (struct page_region __user *)(long)p->arg.vec; 2708 2709 return 0; 2710 } 2711 2712 static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p) 2713 { 2714 const struct page_region *buf = p->vec_buf; 2715 long n = p->vec_buf_index; 2716 2717 if (!p->vec_buf) 2718 return 0; 2719 2720 if (buf[n].end != buf[n].start) 2721 n++; 2722 2723 if (!n) 2724 return 0; 2725 2726 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf))) 2727 return -EFAULT; 2728 2729 p->arg.vec_len -= n; 2730 p->vec_out += n; 2731 2732 p->vec_buf_index = 0; 2733 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len); 2734 p->vec_buf->start = p->vec_buf->end = 0; 2735 2736 return n; 2737 } 2738 2739 static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg) 2740 { 2741 struct pagemap_scan_private p = {0}; 2742 unsigned long walk_start; 2743 size_t n_ranges_out = 0; 2744 int ret; 2745 2746 ret = pagemap_scan_get_args(&p.arg, uarg); 2747 if (ret) 2748 return ret; 2749 2750 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask | 2751 p.arg.return_mask; 2752 ret = pagemap_scan_init_bounce_buffer(&p); 2753 if (ret) 2754 return ret; 2755 2756 for (walk_start = p.arg.start; walk_start < p.arg.end; 2757 walk_start = p.arg.walk_end) { 2758 struct mmu_notifier_range range; 2759 long n_out; 2760 2761 if (fatal_signal_pending(current)) { 2762 ret = -EINTR; 2763 break; 2764 } 2765 2766 ret = mmap_read_lock_killable(mm); 2767 if (ret) 2768 break; 2769 2770 /* Protection change for the range is going to happen. */ 2771 if (p.arg.flags & PM_SCAN_WP_MATCHING) { 2772 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, 2773 mm, walk_start, p.arg.end); 2774 mmu_notifier_invalidate_range_start(&range); 2775 } 2776 2777 ret = walk_page_range(mm, walk_start, p.arg.end, 2778 &pagemap_scan_ops, &p); 2779 2780 if (p.arg.flags & PM_SCAN_WP_MATCHING) 2781 mmu_notifier_invalidate_range_end(&range); 2782 2783 mmap_read_unlock(mm); 2784 2785 n_out = pagemap_scan_flush_buffer(&p); 2786 if (n_out < 0) 2787 ret = n_out; 2788 else 2789 n_ranges_out += n_out; 2790 2791 if (ret != -ENOSPC) 2792 break; 2793 2794 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages) 2795 break; 2796 } 2797 2798 /* ENOSPC signifies early stop (buffer full) from the walk. */ 2799 if (!ret || ret == -ENOSPC) 2800 ret = n_ranges_out; 2801 2802 /* The walk_end isn't set when ret is zero */ 2803 if (!p.arg.walk_end) 2804 p.arg.walk_end = p.arg.end; 2805 if (pagemap_scan_writeback_args(&p.arg, uarg)) 2806 ret = -EFAULT; 2807 2808 kfree(p.vec_buf); 2809 return ret; 2810 } 2811 2812 static long do_pagemap_cmd(struct file *file, unsigned int cmd, 2813 unsigned long arg) 2814 { 2815 struct mm_struct *mm = file->private_data; 2816 2817 switch (cmd) { 2818 case PAGEMAP_SCAN: 2819 return do_pagemap_scan(mm, arg); 2820 2821 default: 2822 return -EINVAL; 2823 } 2824 } 2825 2826 const struct file_operations proc_pagemap_operations = { 2827 .llseek = mem_lseek, /* borrow this */ 2828 .read = pagemap_read, 2829 .open = pagemap_open, 2830 .release = pagemap_release, 2831 .unlocked_ioctl = do_pagemap_cmd, 2832 .compat_ioctl = do_pagemap_cmd, 2833 }; 2834 #endif /* CONFIG_PROC_PAGE_MONITOR */ 2835 2836 #ifdef CONFIG_NUMA 2837 2838 struct numa_maps { 2839 unsigned long pages; 2840 unsigned long anon; 2841 unsigned long active; 2842 unsigned long writeback; 2843 unsigned long mapcount_max; 2844 unsigned long dirty; 2845 unsigned long swapcache; 2846 unsigned long node[MAX_NUMNODES]; 2847 }; 2848 2849 struct numa_maps_private { 2850 struct proc_maps_private proc_maps; 2851 struct numa_maps md; 2852 }; 2853 2854 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 2855 unsigned long nr_pages) 2856 { 2857 struct folio *folio = page_folio(page); 2858 int count = folio_precise_page_mapcount(folio, page); 2859 2860 md->pages += nr_pages; 2861 if (pte_dirty || folio_test_dirty(folio)) 2862 md->dirty += nr_pages; 2863 2864 if (folio_test_swapcache(folio)) 2865 md->swapcache += nr_pages; 2866 2867 if (folio_test_active(folio) || folio_test_unevictable(folio)) 2868 md->active += nr_pages; 2869 2870 if (folio_test_writeback(folio)) 2871 md->writeback += nr_pages; 2872 2873 if (folio_test_anon(folio)) 2874 md->anon += nr_pages; 2875 2876 if (count > md->mapcount_max) 2877 md->mapcount_max = count; 2878 2879 md->node[folio_nid(folio)] += nr_pages; 2880 } 2881 2882 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 2883 unsigned long addr) 2884 { 2885 struct page *page; 2886 int nid; 2887 2888 if (!pte_present(pte)) 2889 return NULL; 2890 2891 page = vm_normal_page(vma, addr, pte); 2892 if (!page || is_zone_device_page(page)) 2893 return NULL; 2894 2895 if (PageReserved(page)) 2896 return NULL; 2897 2898 nid = page_to_nid(page); 2899 if (!node_isset(nid, node_states[N_MEMORY])) 2900 return NULL; 2901 2902 return page; 2903 } 2904 2905 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2906 static struct page *can_gather_numa_stats_pmd(pmd_t pmd, 2907 struct vm_area_struct *vma, 2908 unsigned long addr) 2909 { 2910 struct page *page; 2911 int nid; 2912 2913 if (!pmd_present(pmd)) 2914 return NULL; 2915 2916 page = vm_normal_page_pmd(vma, addr, pmd); 2917 if (!page) 2918 return NULL; 2919 2920 if (PageReserved(page)) 2921 return NULL; 2922 2923 nid = page_to_nid(page); 2924 if (!node_isset(nid, node_states[N_MEMORY])) 2925 return NULL; 2926 2927 return page; 2928 } 2929 #endif 2930 2931 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 2932 unsigned long end, struct mm_walk *walk) 2933 { 2934 struct numa_maps *md = walk->private; 2935 struct vm_area_struct *vma = walk->vma; 2936 spinlock_t *ptl; 2937 pte_t *orig_pte; 2938 pte_t *pte; 2939 2940 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2941 ptl = pmd_trans_huge_lock(pmd, vma); 2942 if (ptl) { 2943 struct page *page; 2944 2945 page = can_gather_numa_stats_pmd(*pmd, vma, addr); 2946 if (page) 2947 gather_stats(page, md, pmd_dirty(*pmd), 2948 HPAGE_PMD_SIZE/PAGE_SIZE); 2949 spin_unlock(ptl); 2950 return 0; 2951 } 2952 #endif 2953 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 2954 if (!pte) { 2955 walk->action = ACTION_AGAIN; 2956 return 0; 2957 } 2958 do { 2959 pte_t ptent = ptep_get(pte); 2960 struct page *page = can_gather_numa_stats(ptent, vma, addr); 2961 if (!page) 2962 continue; 2963 gather_stats(page, md, pte_dirty(ptent), 1); 2964 2965 } while (pte++, addr += PAGE_SIZE, addr != end); 2966 pte_unmap_unlock(orig_pte, ptl); 2967 cond_resched(); 2968 return 0; 2969 } 2970 #ifdef CONFIG_HUGETLB_PAGE 2971 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2972 unsigned long addr, unsigned long end, struct mm_walk *walk) 2973 { 2974 pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte); 2975 struct numa_maps *md; 2976 struct page *page; 2977 2978 if (!pte_present(huge_pte)) 2979 return 0; 2980 2981 page = pte_page(huge_pte); 2982 2983 md = walk->private; 2984 gather_stats(page, md, pte_dirty(huge_pte), 1); 2985 return 0; 2986 } 2987 2988 #else 2989 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2990 unsigned long addr, unsigned long end, struct mm_walk *walk) 2991 { 2992 return 0; 2993 } 2994 #endif 2995 2996 static const struct mm_walk_ops show_numa_ops = { 2997 .hugetlb_entry = gather_hugetlb_stats, 2998 .pmd_entry = gather_pte_stats, 2999 .walk_lock = PGWALK_RDLOCK, 3000 }; 3001 3002 /* 3003 * Display pages allocated per node and memory policy via /proc. 3004 */ 3005 static int show_numa_map(struct seq_file *m, void *v) 3006 { 3007 struct numa_maps_private *numa_priv = m->private; 3008 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 3009 struct vm_area_struct *vma = v; 3010 struct numa_maps *md = &numa_priv->md; 3011 struct file *file = vma->vm_file; 3012 struct mm_struct *mm = vma->vm_mm; 3013 char buffer[64]; 3014 struct mempolicy *pol; 3015 pgoff_t ilx; 3016 int nid; 3017 3018 if (!mm) 3019 return 0; 3020 3021 /* Ensure we start with an empty set of numa_maps statistics. */ 3022 memset(md, 0, sizeof(*md)); 3023 3024 pol = __get_vma_policy(vma, vma->vm_start, &ilx); 3025 if (pol) { 3026 mpol_to_str(buffer, sizeof(buffer), pol); 3027 mpol_cond_put(pol); 3028 } else { 3029 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); 3030 } 3031 3032 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 3033 3034 if (file) { 3035 seq_puts(m, " file="); 3036 seq_path(m, file_user_path(file), "\n\t= "); 3037 } else if (vma_is_initial_heap(vma)) { 3038 seq_puts(m, " heap"); 3039 } else if (vma_is_initial_stack(vma)) { 3040 seq_puts(m, " stack"); 3041 } 3042 3043 if (is_vm_hugetlb_page(vma)) 3044 seq_puts(m, " huge"); 3045 3046 /* mmap_lock is held by m_start */ 3047 walk_page_vma(vma, &show_numa_ops, md); 3048 3049 if (!md->pages) 3050 goto out; 3051 3052 if (md->anon) 3053 seq_printf(m, " anon=%lu", md->anon); 3054 3055 if (md->dirty) 3056 seq_printf(m, " dirty=%lu", md->dirty); 3057 3058 if (md->pages != md->anon && md->pages != md->dirty) 3059 seq_printf(m, " mapped=%lu", md->pages); 3060 3061 if (md->mapcount_max > 1) 3062 seq_printf(m, " mapmax=%lu", md->mapcount_max); 3063 3064 if (md->swapcache) 3065 seq_printf(m, " swapcache=%lu", md->swapcache); 3066 3067 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 3068 seq_printf(m, " active=%lu", md->active); 3069 3070 if (md->writeback) 3071 seq_printf(m, " writeback=%lu", md->writeback); 3072 3073 for_each_node_state(nid, N_MEMORY) 3074 if (md->node[nid]) 3075 seq_printf(m, " N%d=%lu", nid, md->node[nid]); 3076 3077 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); 3078 out: 3079 seq_putc(m, '\n'); 3080 return 0; 3081 } 3082 3083 static const struct seq_operations proc_pid_numa_maps_op = { 3084 .start = m_start, 3085 .next = m_next, 3086 .stop = m_stop, 3087 .show = show_numa_map, 3088 }; 3089 3090 static int pid_numa_maps_open(struct inode *inode, struct file *file) 3091 { 3092 return proc_maps_open(inode, file, &proc_pid_numa_maps_op, 3093 sizeof(struct numa_maps_private)); 3094 } 3095 3096 const struct file_operations proc_pid_numa_maps_operations = { 3097 .open = pid_numa_maps_open, 3098 .read = seq_read, 3099 .llseek = seq_lseek, 3100 .release = proc_map_release, 3101 }; 3102 3103 #endif /* CONFIG_NUMA */ 3104