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.build_id_size) { 547 __u32 build_id_sz; 548 549 err = build_id_parse(vma, build_id_buf, &build_id_sz); 550 if (err) { 551 karg.build_id_size = 0; 552 } else { 553 if (karg.build_id_size < build_id_sz) { 554 err = -ENAMETOOLONG; 555 goto out; 556 } 557 karg.build_id_size = build_id_sz; 558 } 559 } 560 561 if (karg.vma_name_size) { 562 size_t name_buf_sz = min_t(size_t, PATH_MAX, karg.vma_name_size); 563 const struct path *path; 564 const char *name_fmt; 565 size_t name_sz = 0; 566 567 get_vma_name(vma, &path, &name, &name_fmt); 568 569 if (path || name_fmt || name) { 570 name_buf = kmalloc(name_buf_sz, GFP_KERNEL); 571 if (!name_buf) { 572 err = -ENOMEM; 573 goto out; 574 } 575 } 576 if (path) { 577 name = d_path(path, name_buf, name_buf_sz); 578 if (IS_ERR(name)) { 579 err = PTR_ERR(name); 580 goto out; 581 } 582 name_sz = name_buf + name_buf_sz - name; 583 } else if (name || name_fmt) { 584 name_sz = 1 + snprintf(name_buf, name_buf_sz, name_fmt ?: "%s", name); 585 name = name_buf; 586 } 587 if (name_sz > name_buf_sz) { 588 err = -ENAMETOOLONG; 589 goto out; 590 } 591 karg.vma_name_size = name_sz; 592 } 593 594 /* unlock vma or mmap_lock, and put mm_struct before copying data to user */ 595 query_vma_teardown(mm, vma); 596 mmput(mm); 597 598 if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr), 599 name, karg.vma_name_size)) { 600 kfree(name_buf); 601 return -EFAULT; 602 } 603 kfree(name_buf); 604 605 if (karg.build_id_size && copy_to_user(u64_to_user_ptr(karg.build_id_addr), 606 build_id_buf, karg.build_id_size)) 607 return -EFAULT; 608 609 if (copy_to_user(uarg, &karg, min_t(size_t, sizeof(karg), usize))) 610 return -EFAULT; 611 612 return 0; 613 614 out: 615 query_vma_teardown(mm, vma); 616 mmput(mm); 617 kfree(name_buf); 618 return err; 619 } 620 621 static long procfs_procmap_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 622 { 623 struct seq_file *seq = file->private_data; 624 struct proc_maps_private *priv = seq->private; 625 626 switch (cmd) { 627 case PROCMAP_QUERY: 628 return do_procmap_query(priv, (void __user *)arg); 629 default: 630 return -ENOIOCTLCMD; 631 } 632 } 633 634 const struct file_operations proc_pid_maps_operations = { 635 .open = pid_maps_open, 636 .read = seq_read, 637 .llseek = seq_lseek, 638 .release = proc_map_release, 639 .unlocked_ioctl = procfs_procmap_ioctl, 640 .compat_ioctl = compat_ptr_ioctl, 641 }; 642 643 /* 644 * Proportional Set Size(PSS): my share of RSS. 645 * 646 * PSS of a process is the count of pages it has in memory, where each 647 * page is divided by the number of processes sharing it. So if a 648 * process has 1000 pages all to itself, and 1000 shared with one other 649 * process, its PSS will be 1500. 650 * 651 * To keep (accumulated) division errors low, we adopt a 64bit 652 * fixed-point pss counter to minimize division errors. So (pss >> 653 * PSS_SHIFT) would be the real byte count. 654 * 655 * A shift of 12 before division means (assuming 4K page size): 656 * - 1M 3-user-pages add up to 8KB errors; 657 * - supports mapcount up to 2^24, or 16M; 658 * - supports PSS up to 2^52 bytes, or 4PB. 659 */ 660 #define PSS_SHIFT 12 661 662 #ifdef CONFIG_PROC_PAGE_MONITOR 663 struct mem_size_stats { 664 unsigned long resident; 665 unsigned long shared_clean; 666 unsigned long shared_dirty; 667 unsigned long private_clean; 668 unsigned long private_dirty; 669 unsigned long referenced; 670 unsigned long anonymous; 671 unsigned long lazyfree; 672 unsigned long anonymous_thp; 673 unsigned long shmem_thp; 674 unsigned long file_thp; 675 unsigned long swap; 676 unsigned long shared_hugetlb; 677 unsigned long private_hugetlb; 678 unsigned long ksm; 679 u64 pss; 680 u64 pss_anon; 681 u64 pss_file; 682 u64 pss_shmem; 683 u64 pss_dirty; 684 u64 pss_locked; 685 u64 swap_pss; 686 }; 687 688 static void smaps_page_accumulate(struct mem_size_stats *mss, 689 struct folio *folio, unsigned long size, unsigned long pss, 690 bool dirty, bool locked, bool private) 691 { 692 mss->pss += pss; 693 694 if (folio_test_anon(folio)) 695 mss->pss_anon += pss; 696 else if (folio_test_swapbacked(folio)) 697 mss->pss_shmem += pss; 698 else 699 mss->pss_file += pss; 700 701 if (locked) 702 mss->pss_locked += pss; 703 704 if (dirty || folio_test_dirty(folio)) { 705 mss->pss_dirty += pss; 706 if (private) 707 mss->private_dirty += size; 708 else 709 mss->shared_dirty += size; 710 } else { 711 if (private) 712 mss->private_clean += size; 713 else 714 mss->shared_clean += size; 715 } 716 } 717 718 static void smaps_account(struct mem_size_stats *mss, struct page *page, 719 bool compound, bool young, bool dirty, bool locked, 720 bool present) 721 { 722 struct folio *folio = page_folio(page); 723 int i, nr = compound ? compound_nr(page) : 1; 724 unsigned long size = nr * PAGE_SIZE; 725 726 /* 727 * First accumulate quantities that depend only on |size| and the type 728 * of the compound page. 729 */ 730 if (folio_test_anon(folio)) { 731 mss->anonymous += size; 732 if (!folio_test_swapbacked(folio) && !dirty && 733 !folio_test_dirty(folio)) 734 mss->lazyfree += size; 735 } 736 737 if (folio_test_ksm(folio)) 738 mss->ksm += size; 739 740 mss->resident += size; 741 /* Accumulate the size in pages that have been accessed. */ 742 if (young || folio_test_young(folio) || folio_test_referenced(folio)) 743 mss->referenced += size; 744 745 /* 746 * Then accumulate quantities that may depend on sharing, or that may 747 * differ page-by-page. 748 * 749 * refcount == 1 for present entries guarantees that the folio is mapped 750 * exactly once. For large folios this implies that exactly one 751 * PTE/PMD/... maps (a part of) this folio. 752 * 753 * Treat all non-present entries (where relying on the mapcount and 754 * refcount doesn't make sense) as "maybe shared, but not sure how 755 * often". We treat device private entries as being fake-present. 756 * 757 * Note that it would not be safe to read the mapcount especially for 758 * pages referenced by migration entries, even with the PTL held. 759 */ 760 if (folio_ref_count(folio) == 1 || !present) { 761 smaps_page_accumulate(mss, folio, size, size << PSS_SHIFT, 762 dirty, locked, present); 763 return; 764 } 765 /* 766 * We obtain a snapshot of the mapcount. Without holding the folio lock 767 * this snapshot can be slightly wrong as we cannot always read the 768 * mapcount atomically. 769 */ 770 for (i = 0; i < nr; i++, page++) { 771 int mapcount = folio_precise_page_mapcount(folio, page); 772 unsigned long pss = PAGE_SIZE << PSS_SHIFT; 773 if (mapcount >= 2) 774 pss /= mapcount; 775 smaps_page_accumulate(mss, folio, PAGE_SIZE, pss, 776 dirty, locked, mapcount < 2); 777 } 778 } 779 780 #ifdef CONFIG_SHMEM 781 static int smaps_pte_hole(unsigned long addr, unsigned long end, 782 __always_unused int depth, struct mm_walk *walk) 783 { 784 struct mem_size_stats *mss = walk->private; 785 struct vm_area_struct *vma = walk->vma; 786 787 mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping, 788 linear_page_index(vma, addr), 789 linear_page_index(vma, end)); 790 791 return 0; 792 } 793 #else 794 #define smaps_pte_hole NULL 795 #endif /* CONFIG_SHMEM */ 796 797 static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk) 798 { 799 #ifdef CONFIG_SHMEM 800 if (walk->ops->pte_hole) { 801 /* depth is not used */ 802 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk); 803 } 804 #endif 805 } 806 807 static void smaps_pte_entry(pte_t *pte, unsigned long addr, 808 struct mm_walk *walk) 809 { 810 struct mem_size_stats *mss = walk->private; 811 struct vm_area_struct *vma = walk->vma; 812 bool locked = !!(vma->vm_flags & VM_LOCKED); 813 struct page *page = NULL; 814 bool present = false, young = false, dirty = false; 815 pte_t ptent = ptep_get(pte); 816 817 if (pte_present(ptent)) { 818 page = vm_normal_page(vma, addr, ptent); 819 young = pte_young(ptent); 820 dirty = pte_dirty(ptent); 821 present = true; 822 } else if (is_swap_pte(ptent)) { 823 swp_entry_t swpent = pte_to_swp_entry(ptent); 824 825 if (!non_swap_entry(swpent)) { 826 int mapcount; 827 828 mss->swap += PAGE_SIZE; 829 mapcount = swp_swapcount(swpent); 830 if (mapcount >= 2) { 831 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; 832 833 do_div(pss_delta, mapcount); 834 mss->swap_pss += pss_delta; 835 } else { 836 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; 837 } 838 } else if (is_pfn_swap_entry(swpent)) { 839 if (is_device_private_entry(swpent)) 840 present = true; 841 page = pfn_swap_entry_to_page(swpent); 842 } 843 } else { 844 smaps_pte_hole_lookup(addr, walk); 845 return; 846 } 847 848 if (!page) 849 return; 850 851 smaps_account(mss, page, false, young, dirty, locked, present); 852 } 853 854 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 855 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 856 struct mm_walk *walk) 857 { 858 struct mem_size_stats *mss = walk->private; 859 struct vm_area_struct *vma = walk->vma; 860 bool locked = !!(vma->vm_flags & VM_LOCKED); 861 struct page *page = NULL; 862 bool present = false; 863 struct folio *folio; 864 865 if (pmd_present(*pmd)) { 866 page = vm_normal_page_pmd(vma, addr, *pmd); 867 present = true; 868 } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) { 869 swp_entry_t entry = pmd_to_swp_entry(*pmd); 870 871 if (is_pfn_swap_entry(entry)) 872 page = pfn_swap_entry_to_page(entry); 873 } 874 if (IS_ERR_OR_NULL(page)) 875 return; 876 folio = page_folio(page); 877 if (folio_test_anon(folio)) 878 mss->anonymous_thp += HPAGE_PMD_SIZE; 879 else if (folio_test_swapbacked(folio)) 880 mss->shmem_thp += HPAGE_PMD_SIZE; 881 else if (folio_is_zone_device(folio)) 882 /* pass */; 883 else 884 mss->file_thp += HPAGE_PMD_SIZE; 885 886 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), 887 locked, present); 888 } 889 #else 890 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, 891 struct mm_walk *walk) 892 { 893 } 894 #endif 895 896 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 897 struct mm_walk *walk) 898 { 899 struct vm_area_struct *vma = walk->vma; 900 pte_t *pte; 901 spinlock_t *ptl; 902 903 ptl = pmd_trans_huge_lock(pmd, vma); 904 if (ptl) { 905 smaps_pmd_entry(pmd, addr, walk); 906 spin_unlock(ptl); 907 goto out; 908 } 909 910 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 911 if (!pte) { 912 walk->action = ACTION_AGAIN; 913 return 0; 914 } 915 for (; addr != end; pte++, addr += PAGE_SIZE) 916 smaps_pte_entry(pte, addr, walk); 917 pte_unmap_unlock(pte - 1, ptl); 918 out: 919 cond_resched(); 920 return 0; 921 } 922 923 static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) 924 { 925 /* 926 * Don't forget to update Documentation/ on changes. 927 */ 928 static const char mnemonics[BITS_PER_LONG][2] = { 929 /* 930 * In case if we meet a flag we don't know about. 931 */ 932 [0 ... (BITS_PER_LONG-1)] = "??", 933 934 [ilog2(VM_READ)] = "rd", 935 [ilog2(VM_WRITE)] = "wr", 936 [ilog2(VM_EXEC)] = "ex", 937 [ilog2(VM_SHARED)] = "sh", 938 [ilog2(VM_MAYREAD)] = "mr", 939 [ilog2(VM_MAYWRITE)] = "mw", 940 [ilog2(VM_MAYEXEC)] = "me", 941 [ilog2(VM_MAYSHARE)] = "ms", 942 [ilog2(VM_GROWSDOWN)] = "gd", 943 [ilog2(VM_PFNMAP)] = "pf", 944 [ilog2(VM_LOCKED)] = "lo", 945 [ilog2(VM_IO)] = "io", 946 [ilog2(VM_SEQ_READ)] = "sr", 947 [ilog2(VM_RAND_READ)] = "rr", 948 [ilog2(VM_DONTCOPY)] = "dc", 949 [ilog2(VM_DONTEXPAND)] = "de", 950 [ilog2(VM_LOCKONFAULT)] = "lf", 951 [ilog2(VM_ACCOUNT)] = "ac", 952 [ilog2(VM_NORESERVE)] = "nr", 953 [ilog2(VM_HUGETLB)] = "ht", 954 [ilog2(VM_SYNC)] = "sf", 955 [ilog2(VM_ARCH_1)] = "ar", 956 [ilog2(VM_WIPEONFORK)] = "wf", 957 [ilog2(VM_DONTDUMP)] = "dd", 958 #ifdef CONFIG_ARM64_BTI 959 [ilog2(VM_ARM64_BTI)] = "bt", 960 #endif 961 #ifdef CONFIG_MEM_SOFT_DIRTY 962 [ilog2(VM_SOFTDIRTY)] = "sd", 963 #endif 964 [ilog2(VM_MIXEDMAP)] = "mm", 965 [ilog2(VM_HUGEPAGE)] = "hg", 966 [ilog2(VM_NOHUGEPAGE)] = "nh", 967 [ilog2(VM_MERGEABLE)] = "mg", 968 [ilog2(VM_UFFD_MISSING)]= "um", 969 [ilog2(VM_UFFD_WP)] = "uw", 970 #ifdef CONFIG_ARM64_MTE 971 [ilog2(VM_MTE)] = "mt", 972 [ilog2(VM_MTE_ALLOWED)] = "", 973 #endif 974 #ifdef CONFIG_ARCH_HAS_PKEYS 975 /* These come out via ProtectionKey: */ 976 [ilog2(VM_PKEY_BIT0)] = "", 977 [ilog2(VM_PKEY_BIT1)] = "", 978 [ilog2(VM_PKEY_BIT2)] = "", 979 #if VM_PKEY_BIT3 980 [ilog2(VM_PKEY_BIT3)] = "", 981 #endif 982 #if VM_PKEY_BIT4 983 [ilog2(VM_PKEY_BIT4)] = "", 984 #endif 985 #endif /* CONFIG_ARCH_HAS_PKEYS */ 986 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR 987 [ilog2(VM_UFFD_MINOR)] = "ui", 988 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ 989 #ifdef CONFIG_X86_USER_SHADOW_STACK 990 [ilog2(VM_SHADOW_STACK)] = "ss", 991 #endif 992 #if defined(CONFIG_64BIT) || defined(CONFIG_PPC32) 993 [ilog2(VM_DROPPABLE)] = "dp", 994 #endif 995 #ifdef CONFIG_64BIT 996 [ilog2(VM_SEALED)] = "sl", 997 #endif 998 }; 999 size_t i; 1000 1001 seq_puts(m, "VmFlags: "); 1002 for (i = 0; i < BITS_PER_LONG; i++) { 1003 if (!mnemonics[i][0]) 1004 continue; 1005 if (vma->vm_flags & (1UL << i)) { 1006 seq_putc(m, mnemonics[i][0]); 1007 seq_putc(m, mnemonics[i][1]); 1008 seq_putc(m, ' '); 1009 } 1010 } 1011 seq_putc(m, '\n'); 1012 } 1013 1014 #ifdef CONFIG_HUGETLB_PAGE 1015 static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, 1016 unsigned long addr, unsigned long end, 1017 struct mm_walk *walk) 1018 { 1019 struct mem_size_stats *mss = walk->private; 1020 struct vm_area_struct *vma = walk->vma; 1021 pte_t ptent = huge_ptep_get(walk->mm, addr, pte); 1022 struct folio *folio = NULL; 1023 bool present = false; 1024 1025 if (pte_present(ptent)) { 1026 folio = page_folio(pte_page(ptent)); 1027 present = true; 1028 } else if (is_swap_pte(ptent)) { 1029 swp_entry_t swpent = pte_to_swp_entry(ptent); 1030 1031 if (is_pfn_swap_entry(swpent)) 1032 folio = pfn_swap_entry_folio(swpent); 1033 } 1034 1035 if (folio) { 1036 /* We treat non-present entries as "maybe shared". */ 1037 if (!present || folio_likely_mapped_shared(folio) || 1038 hugetlb_pmd_shared(pte)) 1039 mss->shared_hugetlb += huge_page_size(hstate_vma(vma)); 1040 else 1041 mss->private_hugetlb += huge_page_size(hstate_vma(vma)); 1042 } 1043 return 0; 1044 } 1045 #else 1046 #define smaps_hugetlb_range NULL 1047 #endif /* HUGETLB_PAGE */ 1048 1049 static const struct mm_walk_ops smaps_walk_ops = { 1050 .pmd_entry = smaps_pte_range, 1051 .hugetlb_entry = smaps_hugetlb_range, 1052 .walk_lock = PGWALK_RDLOCK, 1053 }; 1054 1055 static const struct mm_walk_ops smaps_shmem_walk_ops = { 1056 .pmd_entry = smaps_pte_range, 1057 .hugetlb_entry = smaps_hugetlb_range, 1058 .pte_hole = smaps_pte_hole, 1059 .walk_lock = PGWALK_RDLOCK, 1060 }; 1061 1062 /* 1063 * Gather mem stats from @vma with the indicated beginning 1064 * address @start, and keep them in @mss. 1065 * 1066 * Use vm_start of @vma as the beginning address if @start is 0. 1067 */ 1068 static void smap_gather_stats(struct vm_area_struct *vma, 1069 struct mem_size_stats *mss, unsigned long start) 1070 { 1071 const struct mm_walk_ops *ops = &smaps_walk_ops; 1072 1073 /* Invalid start */ 1074 if (start >= vma->vm_end) 1075 return; 1076 1077 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { 1078 /* 1079 * For shared or readonly shmem mappings we know that all 1080 * swapped out pages belong to the shmem object, and we can 1081 * obtain the swap value much more efficiently. For private 1082 * writable mappings, we might have COW pages that are 1083 * not affected by the parent swapped out pages of the shmem 1084 * object, so we have to distinguish them during the page walk. 1085 * Unless we know that the shmem object (or the part mapped by 1086 * our VMA) has no swapped out pages at all. 1087 */ 1088 unsigned long shmem_swapped = shmem_swap_usage(vma); 1089 1090 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || 1091 !(vma->vm_flags & VM_WRITE))) { 1092 mss->swap += shmem_swapped; 1093 } else { 1094 ops = &smaps_shmem_walk_ops; 1095 } 1096 } 1097 1098 /* mmap_lock is held in m_start */ 1099 if (!start) 1100 walk_page_vma(vma, ops, mss); 1101 else 1102 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); 1103 } 1104 1105 #define SEQ_PUT_DEC(str, val) \ 1106 seq_put_decimal_ull_width(m, str, (val) >> 10, 8) 1107 1108 /* Show the contents common for smaps and smaps_rollup */ 1109 static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss, 1110 bool rollup_mode) 1111 { 1112 SEQ_PUT_DEC("Rss: ", mss->resident); 1113 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT); 1114 SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT); 1115 if (rollup_mode) { 1116 /* 1117 * These are meaningful only for smaps_rollup, otherwise two of 1118 * them are zero, and the other one is the same as Pss. 1119 */ 1120 SEQ_PUT_DEC(" kB\nPss_Anon: ", 1121 mss->pss_anon >> PSS_SHIFT); 1122 SEQ_PUT_DEC(" kB\nPss_File: ", 1123 mss->pss_file >> PSS_SHIFT); 1124 SEQ_PUT_DEC(" kB\nPss_Shmem: ", 1125 mss->pss_shmem >> PSS_SHIFT); 1126 } 1127 SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean); 1128 SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty); 1129 SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean); 1130 SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty); 1131 SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced); 1132 SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous); 1133 SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm); 1134 SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree); 1135 SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp); 1136 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp); 1137 SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp); 1138 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb); 1139 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ", 1140 mss->private_hugetlb >> 10, 7); 1141 SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); 1142 SEQ_PUT_DEC(" kB\nSwapPss: ", 1143 mss->swap_pss >> PSS_SHIFT); 1144 SEQ_PUT_DEC(" kB\nLocked: ", 1145 mss->pss_locked >> PSS_SHIFT); 1146 seq_puts(m, " kB\n"); 1147 } 1148 1149 static int show_smap(struct seq_file *m, void *v) 1150 { 1151 struct vm_area_struct *vma = v; 1152 struct mem_size_stats mss = {}; 1153 1154 smap_gather_stats(vma, &mss, 0); 1155 1156 show_map_vma(m, vma); 1157 1158 SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start); 1159 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma)); 1160 SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma)); 1161 seq_puts(m, " kB\n"); 1162 1163 __show_smap(m, &mss, false); 1164 1165 seq_printf(m, "THPeligible: %8u\n", 1166 !!thp_vma_allowable_orders(vma, vma->vm_flags, 1167 TVA_SMAPS | TVA_ENFORCE_SYSFS, THP_ORDERS_ALL)); 1168 1169 if (arch_pkeys_enabled()) 1170 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); 1171 show_smap_vma_flags(m, vma); 1172 1173 return 0; 1174 } 1175 1176 static int show_smaps_rollup(struct seq_file *m, void *v) 1177 { 1178 struct proc_maps_private *priv = m->private; 1179 struct mem_size_stats mss = {}; 1180 struct mm_struct *mm = priv->mm; 1181 struct vm_area_struct *vma; 1182 unsigned long vma_start = 0, last_vma_end = 0; 1183 int ret = 0; 1184 VMA_ITERATOR(vmi, mm, 0); 1185 1186 priv->task = get_proc_task(priv->inode); 1187 if (!priv->task) 1188 return -ESRCH; 1189 1190 if (!mm || !mmget_not_zero(mm)) { 1191 ret = -ESRCH; 1192 goto out_put_task; 1193 } 1194 1195 ret = mmap_read_lock_killable(mm); 1196 if (ret) 1197 goto out_put_mm; 1198 1199 hold_task_mempolicy(priv); 1200 vma = vma_next(&vmi); 1201 1202 if (unlikely(!vma)) 1203 goto empty_set; 1204 1205 vma_start = vma->vm_start; 1206 do { 1207 smap_gather_stats(vma, &mss, 0); 1208 last_vma_end = vma->vm_end; 1209 1210 /* 1211 * Release mmap_lock temporarily if someone wants to 1212 * access it for write request. 1213 */ 1214 if (mmap_lock_is_contended(mm)) { 1215 vma_iter_invalidate(&vmi); 1216 mmap_read_unlock(mm); 1217 ret = mmap_read_lock_killable(mm); 1218 if (ret) { 1219 release_task_mempolicy(priv); 1220 goto out_put_mm; 1221 } 1222 1223 /* 1224 * After dropping the lock, there are four cases to 1225 * consider. See the following example for explanation. 1226 * 1227 * +------+------+-----------+ 1228 * | VMA1 | VMA2 | VMA3 | 1229 * +------+------+-----------+ 1230 * | | | | 1231 * 4k 8k 16k 400k 1232 * 1233 * Suppose we drop the lock after reading VMA2 due to 1234 * contention, then we get: 1235 * 1236 * last_vma_end = 16k 1237 * 1238 * 1) VMA2 is freed, but VMA3 exists: 1239 * 1240 * vma_next(vmi) will return VMA3. 1241 * In this case, just continue from VMA3. 1242 * 1243 * 2) VMA2 still exists: 1244 * 1245 * vma_next(vmi) will return VMA3. 1246 * In this case, just continue from VMA3. 1247 * 1248 * 3) No more VMAs can be found: 1249 * 1250 * vma_next(vmi) will return NULL. 1251 * No more things to do, just break. 1252 * 1253 * 4) (last_vma_end - 1) is the middle of a vma (VMA'): 1254 * 1255 * vma_next(vmi) will return VMA' whose range 1256 * contains last_vma_end. 1257 * Iterate VMA' from last_vma_end. 1258 */ 1259 vma = vma_next(&vmi); 1260 /* Case 3 above */ 1261 if (!vma) 1262 break; 1263 1264 /* Case 1 and 2 above */ 1265 if (vma->vm_start >= last_vma_end) { 1266 smap_gather_stats(vma, &mss, 0); 1267 last_vma_end = vma->vm_end; 1268 continue; 1269 } 1270 1271 /* Case 4 above */ 1272 if (vma->vm_end > last_vma_end) { 1273 smap_gather_stats(vma, &mss, last_vma_end); 1274 last_vma_end = vma->vm_end; 1275 } 1276 } 1277 } for_each_vma(vmi, vma); 1278 1279 empty_set: 1280 show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0); 1281 seq_pad(m, ' '); 1282 seq_puts(m, "[rollup]\n"); 1283 1284 __show_smap(m, &mss, true); 1285 1286 release_task_mempolicy(priv); 1287 mmap_read_unlock(mm); 1288 1289 out_put_mm: 1290 mmput(mm); 1291 out_put_task: 1292 put_task_struct(priv->task); 1293 priv->task = NULL; 1294 1295 return ret; 1296 } 1297 #undef SEQ_PUT_DEC 1298 1299 static const struct seq_operations proc_pid_smaps_op = { 1300 .start = m_start, 1301 .next = m_next, 1302 .stop = m_stop, 1303 .show = show_smap 1304 }; 1305 1306 static int pid_smaps_open(struct inode *inode, struct file *file) 1307 { 1308 return do_maps_open(inode, file, &proc_pid_smaps_op); 1309 } 1310 1311 static int smaps_rollup_open(struct inode *inode, struct file *file) 1312 { 1313 int ret; 1314 struct proc_maps_private *priv; 1315 1316 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT); 1317 if (!priv) 1318 return -ENOMEM; 1319 1320 ret = single_open(file, show_smaps_rollup, priv); 1321 if (ret) 1322 goto out_free; 1323 1324 priv->inode = inode; 1325 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 1326 if (IS_ERR(priv->mm)) { 1327 ret = PTR_ERR(priv->mm); 1328 1329 single_release(inode, file); 1330 goto out_free; 1331 } 1332 1333 return 0; 1334 1335 out_free: 1336 kfree(priv); 1337 return ret; 1338 } 1339 1340 static int smaps_rollup_release(struct inode *inode, struct file *file) 1341 { 1342 struct seq_file *seq = file->private_data; 1343 struct proc_maps_private *priv = seq->private; 1344 1345 if (priv->mm) 1346 mmdrop(priv->mm); 1347 1348 kfree(priv); 1349 return single_release(inode, file); 1350 } 1351 1352 const struct file_operations proc_pid_smaps_operations = { 1353 .open = pid_smaps_open, 1354 .read = seq_read, 1355 .llseek = seq_lseek, 1356 .release = proc_map_release, 1357 }; 1358 1359 const struct file_operations proc_pid_smaps_rollup_operations = { 1360 .open = smaps_rollup_open, 1361 .read = seq_read, 1362 .llseek = seq_lseek, 1363 .release = smaps_rollup_release, 1364 }; 1365 1366 enum clear_refs_types { 1367 CLEAR_REFS_ALL = 1, 1368 CLEAR_REFS_ANON, 1369 CLEAR_REFS_MAPPED, 1370 CLEAR_REFS_SOFT_DIRTY, 1371 CLEAR_REFS_MM_HIWATER_RSS, 1372 CLEAR_REFS_LAST, 1373 }; 1374 1375 struct clear_refs_private { 1376 enum clear_refs_types type; 1377 }; 1378 1379 #ifdef CONFIG_MEM_SOFT_DIRTY 1380 1381 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1382 { 1383 struct folio *folio; 1384 1385 if (!pte_write(pte)) 1386 return false; 1387 if (!is_cow_mapping(vma->vm_flags)) 1388 return false; 1389 if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))) 1390 return false; 1391 folio = vm_normal_folio(vma, addr, pte); 1392 if (!folio) 1393 return false; 1394 return folio_maybe_dma_pinned(folio); 1395 } 1396 1397 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1398 unsigned long addr, pte_t *pte) 1399 { 1400 /* 1401 * The soft-dirty tracker uses #PF-s to catch writes 1402 * to pages, so write-protect the pte as well. See the 1403 * Documentation/admin-guide/mm/soft-dirty.rst for full description 1404 * of how soft-dirty works. 1405 */ 1406 pte_t ptent = ptep_get(pte); 1407 1408 if (pte_present(ptent)) { 1409 pte_t old_pte; 1410 1411 if (pte_is_pinned(vma, addr, ptent)) 1412 return; 1413 old_pte = ptep_modify_prot_start(vma, addr, pte); 1414 ptent = pte_wrprotect(old_pte); 1415 ptent = pte_clear_soft_dirty(ptent); 1416 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 1417 } else if (is_swap_pte(ptent)) { 1418 ptent = pte_swp_clear_soft_dirty(ptent); 1419 set_pte_at(vma->vm_mm, addr, pte, ptent); 1420 } 1421 } 1422 #else 1423 static inline void clear_soft_dirty(struct vm_area_struct *vma, 1424 unsigned long addr, pte_t *pte) 1425 { 1426 } 1427 #endif 1428 1429 #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 1430 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1431 unsigned long addr, pmd_t *pmdp) 1432 { 1433 pmd_t old, pmd = *pmdp; 1434 1435 if (pmd_present(pmd)) { 1436 /* See comment in change_huge_pmd() */ 1437 old = pmdp_invalidate(vma, addr, pmdp); 1438 if (pmd_dirty(old)) 1439 pmd = pmd_mkdirty(pmd); 1440 if (pmd_young(old)) 1441 pmd = pmd_mkyoung(pmd); 1442 1443 pmd = pmd_wrprotect(pmd); 1444 pmd = pmd_clear_soft_dirty(pmd); 1445 1446 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1447 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 1448 pmd = pmd_swp_clear_soft_dirty(pmd); 1449 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 1450 } 1451 } 1452 #else 1453 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, 1454 unsigned long addr, pmd_t *pmdp) 1455 { 1456 } 1457 #endif 1458 1459 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 1460 unsigned long end, struct mm_walk *walk) 1461 { 1462 struct clear_refs_private *cp = walk->private; 1463 struct vm_area_struct *vma = walk->vma; 1464 pte_t *pte, ptent; 1465 spinlock_t *ptl; 1466 struct folio *folio; 1467 1468 ptl = pmd_trans_huge_lock(pmd, vma); 1469 if (ptl) { 1470 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1471 clear_soft_dirty_pmd(vma, addr, pmd); 1472 goto out; 1473 } 1474 1475 if (!pmd_present(*pmd)) 1476 goto out; 1477 1478 folio = pmd_folio(*pmd); 1479 1480 /* Clear accessed and referenced bits. */ 1481 pmdp_test_and_clear_young(vma, addr, pmd); 1482 folio_test_clear_young(folio); 1483 folio_clear_referenced(folio); 1484 out: 1485 spin_unlock(ptl); 1486 return 0; 1487 } 1488 1489 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 1490 if (!pte) { 1491 walk->action = ACTION_AGAIN; 1492 return 0; 1493 } 1494 for (; addr != end; pte++, addr += PAGE_SIZE) { 1495 ptent = ptep_get(pte); 1496 1497 if (cp->type == CLEAR_REFS_SOFT_DIRTY) { 1498 clear_soft_dirty(vma, addr, pte); 1499 continue; 1500 } 1501 1502 if (!pte_present(ptent)) 1503 continue; 1504 1505 folio = vm_normal_folio(vma, addr, ptent); 1506 if (!folio) 1507 continue; 1508 1509 /* Clear accessed and referenced bits. */ 1510 ptep_test_and_clear_young(vma, addr, pte); 1511 folio_test_clear_young(folio); 1512 folio_clear_referenced(folio); 1513 } 1514 pte_unmap_unlock(pte - 1, ptl); 1515 cond_resched(); 1516 return 0; 1517 } 1518 1519 static int clear_refs_test_walk(unsigned long start, unsigned long end, 1520 struct mm_walk *walk) 1521 { 1522 struct clear_refs_private *cp = walk->private; 1523 struct vm_area_struct *vma = walk->vma; 1524 1525 if (vma->vm_flags & VM_PFNMAP) 1526 return 1; 1527 1528 /* 1529 * Writing 1 to /proc/pid/clear_refs affects all pages. 1530 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. 1531 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. 1532 * Writing 4 to /proc/pid/clear_refs affects all pages. 1533 */ 1534 if (cp->type == CLEAR_REFS_ANON && vma->vm_file) 1535 return 1; 1536 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) 1537 return 1; 1538 return 0; 1539 } 1540 1541 static const struct mm_walk_ops clear_refs_walk_ops = { 1542 .pmd_entry = clear_refs_pte_range, 1543 .test_walk = clear_refs_test_walk, 1544 .walk_lock = PGWALK_WRLOCK, 1545 }; 1546 1547 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 1548 size_t count, loff_t *ppos) 1549 { 1550 struct task_struct *task; 1551 char buffer[PROC_NUMBUF] = {}; 1552 struct mm_struct *mm; 1553 struct vm_area_struct *vma; 1554 enum clear_refs_types type; 1555 int itype; 1556 int rv; 1557 1558 if (count > sizeof(buffer) - 1) 1559 count = sizeof(buffer) - 1; 1560 if (copy_from_user(buffer, buf, count)) 1561 return -EFAULT; 1562 rv = kstrtoint(strstrip(buffer), 10, &itype); 1563 if (rv < 0) 1564 return rv; 1565 type = (enum clear_refs_types)itype; 1566 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) 1567 return -EINVAL; 1568 1569 task = get_proc_task(file_inode(file)); 1570 if (!task) 1571 return -ESRCH; 1572 mm = get_task_mm(task); 1573 if (mm) { 1574 VMA_ITERATOR(vmi, mm, 0); 1575 struct mmu_notifier_range range; 1576 struct clear_refs_private cp = { 1577 .type = type, 1578 }; 1579 1580 if (mmap_write_lock_killable(mm)) { 1581 count = -EINTR; 1582 goto out_mm; 1583 } 1584 if (type == CLEAR_REFS_MM_HIWATER_RSS) { 1585 /* 1586 * Writing 5 to /proc/pid/clear_refs resets the peak 1587 * resident set size to this mm's current rss value. 1588 */ 1589 reset_mm_hiwater_rss(mm); 1590 goto out_unlock; 1591 } 1592 1593 if (type == CLEAR_REFS_SOFT_DIRTY) { 1594 for_each_vma(vmi, vma) { 1595 if (!(vma->vm_flags & VM_SOFTDIRTY)) 1596 continue; 1597 vm_flags_clear(vma, VM_SOFTDIRTY); 1598 vma_set_page_prot(vma); 1599 } 1600 1601 inc_tlb_flush_pending(mm); 1602 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 1603 0, mm, 0, -1UL); 1604 mmu_notifier_invalidate_range_start(&range); 1605 } 1606 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); 1607 if (type == CLEAR_REFS_SOFT_DIRTY) { 1608 mmu_notifier_invalidate_range_end(&range); 1609 flush_tlb_mm(mm); 1610 dec_tlb_flush_pending(mm); 1611 } 1612 out_unlock: 1613 mmap_write_unlock(mm); 1614 out_mm: 1615 mmput(mm); 1616 } 1617 put_task_struct(task); 1618 1619 return count; 1620 } 1621 1622 const struct file_operations proc_clear_refs_operations = { 1623 .write = clear_refs_write, 1624 .llseek = noop_llseek, 1625 }; 1626 1627 typedef struct { 1628 u64 pme; 1629 } pagemap_entry_t; 1630 1631 struct pagemapread { 1632 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */ 1633 pagemap_entry_t *buffer; 1634 bool show_pfn; 1635 }; 1636 1637 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 1638 #define PAGEMAP_WALK_MASK (PMD_MASK) 1639 1640 #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) 1641 #define PM_PFRAME_BITS 55 1642 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) 1643 #define PM_SOFT_DIRTY BIT_ULL(55) 1644 #define PM_MMAP_EXCLUSIVE BIT_ULL(56) 1645 #define PM_UFFD_WP BIT_ULL(57) 1646 #define PM_FILE BIT_ULL(61) 1647 #define PM_SWAP BIT_ULL(62) 1648 #define PM_PRESENT BIT_ULL(63) 1649 1650 #define PM_END_OF_BUFFER 1 1651 1652 static inline pagemap_entry_t make_pme(u64 frame, u64 flags) 1653 { 1654 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags }; 1655 } 1656 1657 static int add_to_pagemap(pagemap_entry_t *pme, struct pagemapread *pm) 1658 { 1659 pm->buffer[pm->pos++] = *pme; 1660 if (pm->pos >= pm->len) 1661 return PM_END_OF_BUFFER; 1662 return 0; 1663 } 1664 1665 static int pagemap_pte_hole(unsigned long start, unsigned long end, 1666 __always_unused int depth, struct mm_walk *walk) 1667 { 1668 struct pagemapread *pm = walk->private; 1669 unsigned long addr = start; 1670 int err = 0; 1671 1672 while (addr < end) { 1673 struct vm_area_struct *vma = find_vma(walk->mm, addr); 1674 pagemap_entry_t pme = make_pme(0, 0); 1675 /* End of address space hole, which we mark as non-present. */ 1676 unsigned long hole_end; 1677 1678 if (vma) 1679 hole_end = min(end, vma->vm_start); 1680 else 1681 hole_end = end; 1682 1683 for (; addr < hole_end; addr += PAGE_SIZE) { 1684 err = add_to_pagemap(&pme, pm); 1685 if (err) 1686 goto out; 1687 } 1688 1689 if (!vma) 1690 break; 1691 1692 /* Addresses in the VMA. */ 1693 if (vma->vm_flags & VM_SOFTDIRTY) 1694 pme = make_pme(0, PM_SOFT_DIRTY); 1695 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { 1696 err = add_to_pagemap(&pme, pm); 1697 if (err) 1698 goto out; 1699 } 1700 } 1701 out: 1702 return err; 1703 } 1704 1705 static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 1706 struct vm_area_struct *vma, unsigned long addr, pte_t pte) 1707 { 1708 u64 frame = 0, flags = 0; 1709 struct page *page = NULL; 1710 struct folio *folio; 1711 1712 if (pte_present(pte)) { 1713 if (pm->show_pfn) 1714 frame = pte_pfn(pte); 1715 flags |= PM_PRESENT; 1716 page = vm_normal_page(vma, addr, pte); 1717 if (pte_soft_dirty(pte)) 1718 flags |= PM_SOFT_DIRTY; 1719 if (pte_uffd_wp(pte)) 1720 flags |= PM_UFFD_WP; 1721 } else if (is_swap_pte(pte)) { 1722 swp_entry_t entry; 1723 if (pte_swp_soft_dirty(pte)) 1724 flags |= PM_SOFT_DIRTY; 1725 if (pte_swp_uffd_wp(pte)) 1726 flags |= PM_UFFD_WP; 1727 entry = pte_to_swp_entry(pte); 1728 if (pm->show_pfn) { 1729 pgoff_t offset; 1730 /* 1731 * For PFN swap offsets, keeping the offset field 1732 * to be PFN only to be compatible with old smaps. 1733 */ 1734 if (is_pfn_swap_entry(entry)) 1735 offset = swp_offset_pfn(entry); 1736 else 1737 offset = swp_offset(entry); 1738 frame = swp_type(entry) | 1739 (offset << MAX_SWAPFILES_SHIFT); 1740 } 1741 flags |= PM_SWAP; 1742 if (is_pfn_swap_entry(entry)) 1743 page = pfn_swap_entry_to_page(entry); 1744 if (pte_marker_entry_uffd_wp(entry)) 1745 flags |= PM_UFFD_WP; 1746 } 1747 1748 if (page) { 1749 folio = page_folio(page); 1750 if (!folio_test_anon(folio)) 1751 flags |= PM_FILE; 1752 if ((flags & PM_PRESENT) && 1753 folio_precise_page_mapcount(folio, page) == 1) 1754 flags |= PM_MMAP_EXCLUSIVE; 1755 } 1756 if (vma->vm_flags & VM_SOFTDIRTY) 1757 flags |= PM_SOFT_DIRTY; 1758 1759 return make_pme(frame, flags); 1760 } 1761 1762 static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, 1763 struct mm_walk *walk) 1764 { 1765 struct vm_area_struct *vma = walk->vma; 1766 struct pagemapread *pm = walk->private; 1767 spinlock_t *ptl; 1768 pte_t *pte, *orig_pte; 1769 int err = 0; 1770 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1771 1772 ptl = pmd_trans_huge_lock(pmdp, vma); 1773 if (ptl) { 1774 unsigned int idx = (addr & ~PMD_MASK) >> PAGE_SHIFT; 1775 u64 flags = 0, frame = 0; 1776 pmd_t pmd = *pmdp; 1777 struct page *page = NULL; 1778 struct folio *folio = NULL; 1779 1780 if (vma->vm_flags & VM_SOFTDIRTY) 1781 flags |= PM_SOFT_DIRTY; 1782 1783 if (pmd_present(pmd)) { 1784 page = pmd_page(pmd); 1785 1786 flags |= PM_PRESENT; 1787 if (pmd_soft_dirty(pmd)) 1788 flags |= PM_SOFT_DIRTY; 1789 if (pmd_uffd_wp(pmd)) 1790 flags |= PM_UFFD_WP; 1791 if (pm->show_pfn) 1792 frame = pmd_pfn(pmd) + idx; 1793 } 1794 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1795 else if (is_swap_pmd(pmd)) { 1796 swp_entry_t entry = pmd_to_swp_entry(pmd); 1797 unsigned long offset; 1798 1799 if (pm->show_pfn) { 1800 if (is_pfn_swap_entry(entry)) 1801 offset = swp_offset_pfn(entry) + idx; 1802 else 1803 offset = swp_offset(entry) + idx; 1804 frame = swp_type(entry) | 1805 (offset << MAX_SWAPFILES_SHIFT); 1806 } 1807 flags |= PM_SWAP; 1808 if (pmd_swp_soft_dirty(pmd)) 1809 flags |= PM_SOFT_DIRTY; 1810 if (pmd_swp_uffd_wp(pmd)) 1811 flags |= PM_UFFD_WP; 1812 VM_BUG_ON(!is_pmd_migration_entry(pmd)); 1813 page = pfn_swap_entry_to_page(entry); 1814 } 1815 #endif 1816 1817 if (page) { 1818 folio = page_folio(page); 1819 if (!folio_test_anon(folio)) 1820 flags |= PM_FILE; 1821 } 1822 1823 for (; addr != end; addr += PAGE_SIZE, idx++) { 1824 unsigned long cur_flags = flags; 1825 pagemap_entry_t pme; 1826 1827 if (folio && (flags & PM_PRESENT) && 1828 folio_precise_page_mapcount(folio, page + idx) == 1) 1829 cur_flags |= PM_MMAP_EXCLUSIVE; 1830 1831 pme = make_pme(frame, cur_flags); 1832 err = add_to_pagemap(&pme, pm); 1833 if (err) 1834 break; 1835 if (pm->show_pfn) { 1836 if (flags & PM_PRESENT) 1837 frame++; 1838 else if (flags & PM_SWAP) 1839 frame += (1 << MAX_SWAPFILES_SHIFT); 1840 } 1841 } 1842 spin_unlock(ptl); 1843 return err; 1844 } 1845 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1846 1847 /* 1848 * We can assume that @vma always points to a valid one and @end never 1849 * goes beyond vma->vm_end. 1850 */ 1851 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); 1852 if (!pte) { 1853 walk->action = ACTION_AGAIN; 1854 return err; 1855 } 1856 for (; addr < end; pte++, addr += PAGE_SIZE) { 1857 pagemap_entry_t pme; 1858 1859 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte)); 1860 err = add_to_pagemap(&pme, pm); 1861 if (err) 1862 break; 1863 } 1864 pte_unmap_unlock(orig_pte, ptl); 1865 1866 cond_resched(); 1867 1868 return err; 1869 } 1870 1871 #ifdef CONFIG_HUGETLB_PAGE 1872 /* This function walks within one hugetlb entry in the single call */ 1873 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 1874 unsigned long addr, unsigned long end, 1875 struct mm_walk *walk) 1876 { 1877 struct pagemapread *pm = walk->private; 1878 struct vm_area_struct *vma = walk->vma; 1879 u64 flags = 0, frame = 0; 1880 int err = 0; 1881 pte_t pte; 1882 1883 if (vma->vm_flags & VM_SOFTDIRTY) 1884 flags |= PM_SOFT_DIRTY; 1885 1886 pte = huge_ptep_get(walk->mm, addr, ptep); 1887 if (pte_present(pte)) { 1888 struct folio *folio = page_folio(pte_page(pte)); 1889 1890 if (!folio_test_anon(folio)) 1891 flags |= PM_FILE; 1892 1893 if (!folio_likely_mapped_shared(folio) && 1894 !hugetlb_pmd_shared(ptep)) 1895 flags |= PM_MMAP_EXCLUSIVE; 1896 1897 if (huge_pte_uffd_wp(pte)) 1898 flags |= PM_UFFD_WP; 1899 1900 flags |= PM_PRESENT; 1901 if (pm->show_pfn) 1902 frame = pte_pfn(pte) + 1903 ((addr & ~hmask) >> PAGE_SHIFT); 1904 } else if (pte_swp_uffd_wp_any(pte)) { 1905 flags |= PM_UFFD_WP; 1906 } 1907 1908 for (; addr != end; addr += PAGE_SIZE) { 1909 pagemap_entry_t pme = make_pme(frame, flags); 1910 1911 err = add_to_pagemap(&pme, pm); 1912 if (err) 1913 return err; 1914 if (pm->show_pfn && (flags & PM_PRESENT)) 1915 frame++; 1916 } 1917 1918 cond_resched(); 1919 1920 return err; 1921 } 1922 #else 1923 #define pagemap_hugetlb_range NULL 1924 #endif /* HUGETLB_PAGE */ 1925 1926 static const struct mm_walk_ops pagemap_ops = { 1927 .pmd_entry = pagemap_pmd_range, 1928 .pte_hole = pagemap_pte_hole, 1929 .hugetlb_entry = pagemap_hugetlb_range, 1930 .walk_lock = PGWALK_RDLOCK, 1931 }; 1932 1933 /* 1934 * /proc/pid/pagemap - an array mapping virtual pages to pfns 1935 * 1936 * For each page in the address space, this file contains one 64-bit entry 1937 * consisting of the following: 1938 * 1939 * Bits 0-54 page frame number (PFN) if present 1940 * Bits 0-4 swap type if swapped 1941 * Bits 5-54 swap offset if swapped 1942 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) 1943 * Bit 56 page exclusively mapped 1944 * Bit 57 pte is uffd-wp write-protected 1945 * Bits 58-60 zero 1946 * Bit 61 page is file-page or shared-anon 1947 * Bit 62 page swapped 1948 * Bit 63 page present 1949 * 1950 * If the page is not present but in swap, then the PFN contains an 1951 * encoding of the swap file number and the page's offset into the 1952 * swap. Unmapped pages return a null PFN. This allows determining 1953 * precisely which pages are mapped (or in swap) and comparing mapped 1954 * pages between processes. 1955 * 1956 * Efficient users of this interface will use /proc/pid/maps to 1957 * determine which areas of memory are actually mapped and llseek to 1958 * skip over unmapped regions. 1959 */ 1960 static ssize_t pagemap_read(struct file *file, char __user *buf, 1961 size_t count, loff_t *ppos) 1962 { 1963 struct mm_struct *mm = file->private_data; 1964 struct pagemapread pm; 1965 unsigned long src; 1966 unsigned long svpfn; 1967 unsigned long start_vaddr; 1968 unsigned long end_vaddr; 1969 int ret = 0, copied = 0; 1970 1971 if (!mm || !mmget_not_zero(mm)) 1972 goto out; 1973 1974 ret = -EINVAL; 1975 /* file position must be aligned */ 1976 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 1977 goto out_mm; 1978 1979 ret = 0; 1980 if (!count) 1981 goto out_mm; 1982 1983 /* do not disclose physical addresses: attack vector */ 1984 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); 1985 1986 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 1987 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); 1988 ret = -ENOMEM; 1989 if (!pm.buffer) 1990 goto out_mm; 1991 1992 src = *ppos; 1993 svpfn = src / PM_ENTRY_BYTES; 1994 end_vaddr = mm->task_size; 1995 1996 /* watch out for wraparound */ 1997 start_vaddr = end_vaddr; 1998 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) { 1999 unsigned long end; 2000 2001 ret = mmap_read_lock_killable(mm); 2002 if (ret) 2003 goto out_free; 2004 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT); 2005 mmap_read_unlock(mm); 2006 2007 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT); 2008 if (end >= start_vaddr && end < mm->task_size) 2009 end_vaddr = end; 2010 } 2011 2012 /* Ensure the address is inside the task */ 2013 if (start_vaddr > mm->task_size) 2014 start_vaddr = end_vaddr; 2015 2016 ret = 0; 2017 while (count && (start_vaddr < end_vaddr)) { 2018 int len; 2019 unsigned long end; 2020 2021 pm.pos = 0; 2022 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 2023 /* overflow ? */ 2024 if (end < start_vaddr || end > end_vaddr) 2025 end = end_vaddr; 2026 ret = mmap_read_lock_killable(mm); 2027 if (ret) 2028 goto out_free; 2029 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm); 2030 mmap_read_unlock(mm); 2031 start_vaddr = end; 2032 2033 len = min(count, PM_ENTRY_BYTES * pm.pos); 2034 if (copy_to_user(buf, pm.buffer, len)) { 2035 ret = -EFAULT; 2036 goto out_free; 2037 } 2038 copied += len; 2039 buf += len; 2040 count -= len; 2041 } 2042 *ppos += copied; 2043 if (!ret || ret == PM_END_OF_BUFFER) 2044 ret = copied; 2045 2046 out_free: 2047 kfree(pm.buffer); 2048 out_mm: 2049 mmput(mm); 2050 out: 2051 return ret; 2052 } 2053 2054 static int pagemap_open(struct inode *inode, struct file *file) 2055 { 2056 struct mm_struct *mm; 2057 2058 mm = proc_mem_open(inode, PTRACE_MODE_READ); 2059 if (IS_ERR(mm)) 2060 return PTR_ERR(mm); 2061 file->private_data = mm; 2062 return 0; 2063 } 2064 2065 static int pagemap_release(struct inode *inode, struct file *file) 2066 { 2067 struct mm_struct *mm = file->private_data; 2068 2069 if (mm) 2070 mmdrop(mm); 2071 return 0; 2072 } 2073 2074 #define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \ 2075 PAGE_IS_FILE | PAGE_IS_PRESENT | \ 2076 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \ 2077 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY) 2078 #define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC) 2079 2080 struct pagemap_scan_private { 2081 struct pm_scan_arg arg; 2082 unsigned long masks_of_interest, cur_vma_category; 2083 struct page_region *vec_buf; 2084 unsigned long vec_buf_len, vec_buf_index, found_pages; 2085 struct page_region __user *vec_out; 2086 }; 2087 2088 static unsigned long pagemap_page_category(struct pagemap_scan_private *p, 2089 struct vm_area_struct *vma, 2090 unsigned long addr, pte_t pte) 2091 { 2092 unsigned long categories = 0; 2093 2094 if (pte_present(pte)) { 2095 struct page *page; 2096 2097 categories |= PAGE_IS_PRESENT; 2098 if (!pte_uffd_wp(pte)) 2099 categories |= PAGE_IS_WRITTEN; 2100 2101 if (p->masks_of_interest & PAGE_IS_FILE) { 2102 page = vm_normal_page(vma, addr, pte); 2103 if (page && !PageAnon(page)) 2104 categories |= PAGE_IS_FILE; 2105 } 2106 2107 if (is_zero_pfn(pte_pfn(pte))) 2108 categories |= PAGE_IS_PFNZERO; 2109 if (pte_soft_dirty(pte)) 2110 categories |= PAGE_IS_SOFT_DIRTY; 2111 } else if (is_swap_pte(pte)) { 2112 swp_entry_t swp; 2113 2114 categories |= PAGE_IS_SWAPPED; 2115 if (!pte_swp_uffd_wp_any(pte)) 2116 categories |= PAGE_IS_WRITTEN; 2117 2118 if (p->masks_of_interest & PAGE_IS_FILE) { 2119 swp = pte_to_swp_entry(pte); 2120 if (is_pfn_swap_entry(swp) && 2121 !folio_test_anon(pfn_swap_entry_folio(swp))) 2122 categories |= PAGE_IS_FILE; 2123 } 2124 if (pte_swp_soft_dirty(pte)) 2125 categories |= PAGE_IS_SOFT_DIRTY; 2126 } 2127 2128 return categories; 2129 } 2130 2131 static void make_uffd_wp_pte(struct vm_area_struct *vma, 2132 unsigned long addr, pte_t *pte, pte_t ptent) 2133 { 2134 if (pte_present(ptent)) { 2135 pte_t old_pte; 2136 2137 old_pte = ptep_modify_prot_start(vma, addr, pte); 2138 ptent = pte_mkuffd_wp(old_pte); 2139 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); 2140 } else if (is_swap_pte(ptent)) { 2141 ptent = pte_swp_mkuffd_wp(ptent); 2142 set_pte_at(vma->vm_mm, addr, pte, ptent); 2143 } else { 2144 set_pte_at(vma->vm_mm, addr, pte, 2145 make_pte_marker(PTE_MARKER_UFFD_WP)); 2146 } 2147 } 2148 2149 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2150 static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, 2151 struct vm_area_struct *vma, 2152 unsigned long addr, pmd_t pmd) 2153 { 2154 unsigned long categories = PAGE_IS_HUGE; 2155 2156 if (pmd_present(pmd)) { 2157 struct page *page; 2158 2159 categories |= PAGE_IS_PRESENT; 2160 if (!pmd_uffd_wp(pmd)) 2161 categories |= PAGE_IS_WRITTEN; 2162 2163 if (p->masks_of_interest & PAGE_IS_FILE) { 2164 page = vm_normal_page_pmd(vma, addr, pmd); 2165 if (page && !PageAnon(page)) 2166 categories |= PAGE_IS_FILE; 2167 } 2168 2169 if (is_zero_pfn(pmd_pfn(pmd))) 2170 categories |= PAGE_IS_PFNZERO; 2171 if (pmd_soft_dirty(pmd)) 2172 categories |= PAGE_IS_SOFT_DIRTY; 2173 } else if (is_swap_pmd(pmd)) { 2174 swp_entry_t swp; 2175 2176 categories |= PAGE_IS_SWAPPED; 2177 if (!pmd_swp_uffd_wp(pmd)) 2178 categories |= PAGE_IS_WRITTEN; 2179 if (pmd_swp_soft_dirty(pmd)) 2180 categories |= PAGE_IS_SOFT_DIRTY; 2181 2182 if (p->masks_of_interest & PAGE_IS_FILE) { 2183 swp = pmd_to_swp_entry(pmd); 2184 if (is_pfn_swap_entry(swp) && 2185 !folio_test_anon(pfn_swap_entry_folio(swp))) 2186 categories |= PAGE_IS_FILE; 2187 } 2188 } 2189 2190 return categories; 2191 } 2192 2193 static void make_uffd_wp_pmd(struct vm_area_struct *vma, 2194 unsigned long addr, pmd_t *pmdp) 2195 { 2196 pmd_t old, pmd = *pmdp; 2197 2198 if (pmd_present(pmd)) { 2199 old = pmdp_invalidate_ad(vma, addr, pmdp); 2200 pmd = pmd_mkuffd_wp(old); 2201 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 2202 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { 2203 pmd = pmd_swp_mkuffd_wp(pmd); 2204 set_pmd_at(vma->vm_mm, addr, pmdp, pmd); 2205 } 2206 } 2207 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 2208 2209 #ifdef CONFIG_HUGETLB_PAGE 2210 static unsigned long pagemap_hugetlb_category(pte_t pte) 2211 { 2212 unsigned long categories = PAGE_IS_HUGE; 2213 2214 /* 2215 * According to pagemap_hugetlb_range(), file-backed HugeTLB 2216 * page cannot be swapped. So PAGE_IS_FILE is not checked for 2217 * swapped pages. 2218 */ 2219 if (pte_present(pte)) { 2220 categories |= PAGE_IS_PRESENT; 2221 if (!huge_pte_uffd_wp(pte)) 2222 categories |= PAGE_IS_WRITTEN; 2223 if (!PageAnon(pte_page(pte))) 2224 categories |= PAGE_IS_FILE; 2225 if (is_zero_pfn(pte_pfn(pte))) 2226 categories |= PAGE_IS_PFNZERO; 2227 if (pte_soft_dirty(pte)) 2228 categories |= PAGE_IS_SOFT_DIRTY; 2229 } else if (is_swap_pte(pte)) { 2230 categories |= PAGE_IS_SWAPPED; 2231 if (!pte_swp_uffd_wp_any(pte)) 2232 categories |= PAGE_IS_WRITTEN; 2233 if (pte_swp_soft_dirty(pte)) 2234 categories |= PAGE_IS_SOFT_DIRTY; 2235 } 2236 2237 return categories; 2238 } 2239 2240 static void make_uffd_wp_huge_pte(struct vm_area_struct *vma, 2241 unsigned long addr, pte_t *ptep, 2242 pte_t ptent) 2243 { 2244 unsigned long psize; 2245 2246 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) 2247 return; 2248 2249 psize = huge_page_size(hstate_vma(vma)); 2250 2251 if (is_hugetlb_entry_migration(ptent)) 2252 set_huge_pte_at(vma->vm_mm, addr, ptep, 2253 pte_swp_mkuffd_wp(ptent), psize); 2254 else if (!huge_pte_none(ptent)) 2255 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, 2256 huge_pte_mkuffd_wp(ptent)); 2257 else 2258 set_huge_pte_at(vma->vm_mm, addr, ptep, 2259 make_pte_marker(PTE_MARKER_UFFD_WP), psize); 2260 } 2261 #endif /* CONFIG_HUGETLB_PAGE */ 2262 2263 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) 2264 static void pagemap_scan_backout_range(struct pagemap_scan_private *p, 2265 unsigned long addr, unsigned long end) 2266 { 2267 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2268 2269 if (cur_buf->start != addr) 2270 cur_buf->end = addr; 2271 else 2272 cur_buf->start = cur_buf->end = 0; 2273 2274 p->found_pages -= (end - addr) / PAGE_SIZE; 2275 } 2276 #endif 2277 2278 static bool pagemap_scan_is_interesting_page(unsigned long categories, 2279 const struct pagemap_scan_private *p) 2280 { 2281 categories ^= p->arg.category_inverted; 2282 if ((categories & p->arg.category_mask) != p->arg.category_mask) 2283 return false; 2284 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask)) 2285 return false; 2286 2287 return true; 2288 } 2289 2290 static bool pagemap_scan_is_interesting_vma(unsigned long categories, 2291 const struct pagemap_scan_private *p) 2292 { 2293 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED; 2294 2295 categories ^= p->arg.category_inverted; 2296 if ((categories & required) != required) 2297 return false; 2298 2299 return true; 2300 } 2301 2302 static int pagemap_scan_test_walk(unsigned long start, unsigned long end, 2303 struct mm_walk *walk) 2304 { 2305 struct pagemap_scan_private *p = walk->private; 2306 struct vm_area_struct *vma = walk->vma; 2307 unsigned long vma_category = 0; 2308 bool wp_allowed = userfaultfd_wp_async(vma) && 2309 userfaultfd_wp_use_markers(vma); 2310 2311 if (!wp_allowed) { 2312 /* User requested explicit failure over wp-async capability */ 2313 if (p->arg.flags & PM_SCAN_CHECK_WPASYNC) 2314 return -EPERM; 2315 /* 2316 * User requires wr-protect, and allows silently skipping 2317 * unsupported vmas. 2318 */ 2319 if (p->arg.flags & PM_SCAN_WP_MATCHING) 2320 return 1; 2321 /* 2322 * Then the request doesn't involve wr-protects at all, 2323 * fall through to the rest checks, and allow vma walk. 2324 */ 2325 } 2326 2327 if (vma->vm_flags & VM_PFNMAP) 2328 return 1; 2329 2330 if (wp_allowed) 2331 vma_category |= PAGE_IS_WPALLOWED; 2332 2333 if (vma->vm_flags & VM_SOFTDIRTY) 2334 vma_category |= PAGE_IS_SOFT_DIRTY; 2335 2336 if (!pagemap_scan_is_interesting_vma(vma_category, p)) 2337 return 1; 2338 2339 p->cur_vma_category = vma_category; 2340 2341 return 0; 2342 } 2343 2344 static bool pagemap_scan_push_range(unsigned long categories, 2345 struct pagemap_scan_private *p, 2346 unsigned long addr, unsigned long end) 2347 { 2348 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; 2349 2350 /* 2351 * When there is no output buffer provided at all, the sentinel values 2352 * won't match here. There is no other way for `cur_buf->end` to be 2353 * non-zero other than it being non-empty. 2354 */ 2355 if (addr == cur_buf->end && categories == cur_buf->categories) { 2356 cur_buf->end = end; 2357 return true; 2358 } 2359 2360 if (cur_buf->end) { 2361 if (p->vec_buf_index >= p->vec_buf_len - 1) 2362 return false; 2363 2364 cur_buf = &p->vec_buf[++p->vec_buf_index]; 2365 } 2366 2367 cur_buf->start = addr; 2368 cur_buf->end = end; 2369 cur_buf->categories = categories; 2370 2371 return true; 2372 } 2373 2374 static int pagemap_scan_output(unsigned long categories, 2375 struct pagemap_scan_private *p, 2376 unsigned long addr, unsigned long *end) 2377 { 2378 unsigned long n_pages, total_pages; 2379 int ret = 0; 2380 2381 if (!p->vec_buf) 2382 return 0; 2383 2384 categories &= p->arg.return_mask; 2385 2386 n_pages = (*end - addr) / PAGE_SIZE; 2387 if (check_add_overflow(p->found_pages, n_pages, &total_pages) || 2388 total_pages > p->arg.max_pages) { 2389 size_t n_too_much = total_pages - p->arg.max_pages; 2390 *end -= n_too_much * PAGE_SIZE; 2391 n_pages -= n_too_much; 2392 ret = -ENOSPC; 2393 } 2394 2395 if (!pagemap_scan_push_range(categories, p, addr, *end)) { 2396 *end = addr; 2397 n_pages = 0; 2398 ret = -ENOSPC; 2399 } 2400 2401 p->found_pages += n_pages; 2402 if (ret) 2403 p->arg.walk_end = *end; 2404 2405 return ret; 2406 } 2407 2408 static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start, 2409 unsigned long end, struct mm_walk *walk) 2410 { 2411 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2412 struct pagemap_scan_private *p = walk->private; 2413 struct vm_area_struct *vma = walk->vma; 2414 unsigned long categories; 2415 spinlock_t *ptl; 2416 int ret = 0; 2417 2418 ptl = pmd_trans_huge_lock(pmd, vma); 2419 if (!ptl) 2420 return -ENOENT; 2421 2422 categories = p->cur_vma_category | 2423 pagemap_thp_category(p, vma, start, *pmd); 2424 2425 if (!pagemap_scan_is_interesting_page(categories, p)) 2426 goto out_unlock; 2427 2428 ret = pagemap_scan_output(categories, p, start, &end); 2429 if (start == end) 2430 goto out_unlock; 2431 2432 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2433 goto out_unlock; 2434 if (~categories & PAGE_IS_WRITTEN) 2435 goto out_unlock; 2436 2437 /* 2438 * Break huge page into small pages if the WP operation 2439 * needs to be performed on a portion of the huge page. 2440 */ 2441 if (end != start + HPAGE_SIZE) { 2442 spin_unlock(ptl); 2443 split_huge_pmd(vma, pmd, start); 2444 pagemap_scan_backout_range(p, start, end); 2445 /* Report as if there was no THP */ 2446 return -ENOENT; 2447 } 2448 2449 make_uffd_wp_pmd(vma, start, pmd); 2450 flush_tlb_range(vma, start, end); 2451 out_unlock: 2452 spin_unlock(ptl); 2453 return ret; 2454 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 2455 return -ENOENT; 2456 #endif 2457 } 2458 2459 static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, 2460 unsigned long end, struct mm_walk *walk) 2461 { 2462 struct pagemap_scan_private *p = walk->private; 2463 struct vm_area_struct *vma = walk->vma; 2464 unsigned long addr, flush_end = 0; 2465 pte_t *pte, *start_pte; 2466 spinlock_t *ptl; 2467 int ret; 2468 2469 arch_enter_lazy_mmu_mode(); 2470 2471 ret = pagemap_scan_thp_entry(pmd, start, end, walk); 2472 if (ret != -ENOENT) { 2473 arch_leave_lazy_mmu_mode(); 2474 return ret; 2475 } 2476 2477 ret = 0; 2478 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); 2479 if (!pte) { 2480 arch_leave_lazy_mmu_mode(); 2481 walk->action = ACTION_AGAIN; 2482 return 0; 2483 } 2484 2485 if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { 2486 /* Fast path for performing exclusive WP */ 2487 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2488 pte_t ptent = ptep_get(pte); 2489 2490 if ((pte_present(ptent) && pte_uffd_wp(ptent)) || 2491 pte_swp_uffd_wp_any(ptent)) 2492 continue; 2493 make_uffd_wp_pte(vma, addr, pte, ptent); 2494 if (!flush_end) 2495 start = addr; 2496 flush_end = addr + PAGE_SIZE; 2497 } 2498 goto flush_and_return; 2499 } 2500 2501 if (!p->arg.category_anyof_mask && !p->arg.category_inverted && 2502 p->arg.category_mask == PAGE_IS_WRITTEN && 2503 p->arg.return_mask == PAGE_IS_WRITTEN) { 2504 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) { 2505 unsigned long next = addr + PAGE_SIZE; 2506 pte_t ptent = ptep_get(pte); 2507 2508 if ((pte_present(ptent) && pte_uffd_wp(ptent)) || 2509 pte_swp_uffd_wp_any(ptent)) 2510 continue; 2511 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN, 2512 p, addr, &next); 2513 if (next == addr) 2514 break; 2515 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2516 continue; 2517 make_uffd_wp_pte(vma, addr, pte, ptent); 2518 if (!flush_end) 2519 start = addr; 2520 flush_end = next; 2521 } 2522 goto flush_and_return; 2523 } 2524 2525 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { 2526 pte_t ptent = ptep_get(pte); 2527 unsigned long categories = p->cur_vma_category | 2528 pagemap_page_category(p, vma, addr, ptent); 2529 unsigned long next = addr + PAGE_SIZE; 2530 2531 if (!pagemap_scan_is_interesting_page(categories, p)) 2532 continue; 2533 2534 ret = pagemap_scan_output(categories, p, addr, &next); 2535 if (next == addr) 2536 break; 2537 2538 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2539 continue; 2540 if (~categories & PAGE_IS_WRITTEN) 2541 continue; 2542 2543 make_uffd_wp_pte(vma, addr, pte, ptent); 2544 if (!flush_end) 2545 start = addr; 2546 flush_end = next; 2547 } 2548 2549 flush_and_return: 2550 if (flush_end) 2551 flush_tlb_range(vma, start, addr); 2552 2553 pte_unmap_unlock(start_pte, ptl); 2554 arch_leave_lazy_mmu_mode(); 2555 2556 cond_resched(); 2557 return ret; 2558 } 2559 2560 #ifdef CONFIG_HUGETLB_PAGE 2561 static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, 2562 unsigned long start, unsigned long end, 2563 struct mm_walk *walk) 2564 { 2565 struct pagemap_scan_private *p = walk->private; 2566 struct vm_area_struct *vma = walk->vma; 2567 unsigned long categories; 2568 spinlock_t *ptl; 2569 int ret = 0; 2570 pte_t pte; 2571 2572 if (~p->arg.flags & PM_SCAN_WP_MATCHING) { 2573 /* Go the short route when not write-protecting pages. */ 2574 2575 pte = huge_ptep_get(walk->mm, start, ptep); 2576 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2577 2578 if (!pagemap_scan_is_interesting_page(categories, p)) 2579 return 0; 2580 2581 return pagemap_scan_output(categories, p, start, &end); 2582 } 2583 2584 i_mmap_lock_write(vma->vm_file->f_mapping); 2585 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep); 2586 2587 pte = huge_ptep_get(walk->mm, start, ptep); 2588 categories = p->cur_vma_category | pagemap_hugetlb_category(pte); 2589 2590 if (!pagemap_scan_is_interesting_page(categories, p)) 2591 goto out_unlock; 2592 2593 ret = pagemap_scan_output(categories, p, start, &end); 2594 if (start == end) 2595 goto out_unlock; 2596 2597 if (~categories & PAGE_IS_WRITTEN) 2598 goto out_unlock; 2599 2600 if (end != start + HPAGE_SIZE) { 2601 /* Partial HugeTLB page WP isn't possible. */ 2602 pagemap_scan_backout_range(p, start, end); 2603 p->arg.walk_end = start; 2604 ret = 0; 2605 goto out_unlock; 2606 } 2607 2608 make_uffd_wp_huge_pte(vma, start, ptep, pte); 2609 flush_hugetlb_tlb_range(vma, start, end); 2610 2611 out_unlock: 2612 spin_unlock(ptl); 2613 i_mmap_unlock_write(vma->vm_file->f_mapping); 2614 2615 return ret; 2616 } 2617 #else 2618 #define pagemap_scan_hugetlb_entry NULL 2619 #endif 2620 2621 static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, 2622 int depth, struct mm_walk *walk) 2623 { 2624 struct pagemap_scan_private *p = walk->private; 2625 struct vm_area_struct *vma = walk->vma; 2626 int ret, err; 2627 2628 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p)) 2629 return 0; 2630 2631 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end); 2632 if (addr == end) 2633 return ret; 2634 2635 if (~p->arg.flags & PM_SCAN_WP_MATCHING) 2636 return ret; 2637 2638 err = uffd_wp_range(vma, addr, end - addr, true); 2639 if (err < 0) 2640 ret = err; 2641 2642 return ret; 2643 } 2644 2645 static const struct mm_walk_ops pagemap_scan_ops = { 2646 .test_walk = pagemap_scan_test_walk, 2647 .pmd_entry = pagemap_scan_pmd_entry, 2648 .pte_hole = pagemap_scan_pte_hole, 2649 .hugetlb_entry = pagemap_scan_hugetlb_entry, 2650 }; 2651 2652 static int pagemap_scan_get_args(struct pm_scan_arg *arg, 2653 unsigned long uarg) 2654 { 2655 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg))) 2656 return -EFAULT; 2657 2658 if (arg->size != sizeof(struct pm_scan_arg)) 2659 return -EINVAL; 2660 2661 /* Validate requested features */ 2662 if (arg->flags & ~PM_SCAN_FLAGS) 2663 return -EINVAL; 2664 if ((arg->category_inverted | arg->category_mask | 2665 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) 2666 return -EINVAL; 2667 2668 arg->start = untagged_addr((unsigned long)arg->start); 2669 arg->end = untagged_addr((unsigned long)arg->end); 2670 arg->vec = untagged_addr((unsigned long)arg->vec); 2671 2672 /* Validate memory pointers */ 2673 if (!IS_ALIGNED(arg->start, PAGE_SIZE)) 2674 return -EINVAL; 2675 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start)) 2676 return -EFAULT; 2677 if (!arg->vec && arg->vec_len) 2678 return -EINVAL; 2679 if (arg->vec && !access_ok((void __user *)(long)arg->vec, 2680 arg->vec_len * sizeof(struct page_region))) 2681 return -EFAULT; 2682 2683 /* Fixup default values */ 2684 arg->end = ALIGN(arg->end, PAGE_SIZE); 2685 arg->walk_end = 0; 2686 if (!arg->max_pages) 2687 arg->max_pages = ULONG_MAX; 2688 2689 return 0; 2690 } 2691 2692 static int pagemap_scan_writeback_args(struct pm_scan_arg *arg, 2693 unsigned long uargl) 2694 { 2695 struct pm_scan_arg __user *uarg = (void __user *)uargl; 2696 2697 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end))) 2698 return -EFAULT; 2699 2700 return 0; 2701 } 2702 2703 static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p) 2704 { 2705 if (!p->arg.vec_len) 2706 return 0; 2707 2708 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT, 2709 p->arg.vec_len); 2710 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf), 2711 GFP_KERNEL); 2712 if (!p->vec_buf) 2713 return -ENOMEM; 2714 2715 p->vec_buf->start = p->vec_buf->end = 0; 2716 p->vec_out = (struct page_region __user *)(long)p->arg.vec; 2717 2718 return 0; 2719 } 2720 2721 static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p) 2722 { 2723 const struct page_region *buf = p->vec_buf; 2724 long n = p->vec_buf_index; 2725 2726 if (!p->vec_buf) 2727 return 0; 2728 2729 if (buf[n].end != buf[n].start) 2730 n++; 2731 2732 if (!n) 2733 return 0; 2734 2735 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf))) 2736 return -EFAULT; 2737 2738 p->arg.vec_len -= n; 2739 p->vec_out += n; 2740 2741 p->vec_buf_index = 0; 2742 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len); 2743 p->vec_buf->start = p->vec_buf->end = 0; 2744 2745 return n; 2746 } 2747 2748 static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg) 2749 { 2750 struct pagemap_scan_private p = {0}; 2751 unsigned long walk_start; 2752 size_t n_ranges_out = 0; 2753 int ret; 2754 2755 ret = pagemap_scan_get_args(&p.arg, uarg); 2756 if (ret) 2757 return ret; 2758 2759 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask | 2760 p.arg.return_mask; 2761 ret = pagemap_scan_init_bounce_buffer(&p); 2762 if (ret) 2763 return ret; 2764 2765 for (walk_start = p.arg.start; walk_start < p.arg.end; 2766 walk_start = p.arg.walk_end) { 2767 struct mmu_notifier_range range; 2768 long n_out; 2769 2770 if (fatal_signal_pending(current)) { 2771 ret = -EINTR; 2772 break; 2773 } 2774 2775 ret = mmap_read_lock_killable(mm); 2776 if (ret) 2777 break; 2778 2779 /* Protection change for the range is going to happen. */ 2780 if (p.arg.flags & PM_SCAN_WP_MATCHING) { 2781 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, 2782 mm, walk_start, p.arg.end); 2783 mmu_notifier_invalidate_range_start(&range); 2784 } 2785 2786 ret = walk_page_range(mm, walk_start, p.arg.end, 2787 &pagemap_scan_ops, &p); 2788 2789 if (p.arg.flags & PM_SCAN_WP_MATCHING) 2790 mmu_notifier_invalidate_range_end(&range); 2791 2792 mmap_read_unlock(mm); 2793 2794 n_out = pagemap_scan_flush_buffer(&p); 2795 if (n_out < 0) 2796 ret = n_out; 2797 else 2798 n_ranges_out += n_out; 2799 2800 if (ret != -ENOSPC) 2801 break; 2802 2803 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages) 2804 break; 2805 } 2806 2807 /* ENOSPC signifies early stop (buffer full) from the walk. */ 2808 if (!ret || ret == -ENOSPC) 2809 ret = n_ranges_out; 2810 2811 /* The walk_end isn't set when ret is zero */ 2812 if (!p.arg.walk_end) 2813 p.arg.walk_end = p.arg.end; 2814 if (pagemap_scan_writeback_args(&p.arg, uarg)) 2815 ret = -EFAULT; 2816 2817 kfree(p.vec_buf); 2818 return ret; 2819 } 2820 2821 static long do_pagemap_cmd(struct file *file, unsigned int cmd, 2822 unsigned long arg) 2823 { 2824 struct mm_struct *mm = file->private_data; 2825 2826 switch (cmd) { 2827 case PAGEMAP_SCAN: 2828 return do_pagemap_scan(mm, arg); 2829 2830 default: 2831 return -EINVAL; 2832 } 2833 } 2834 2835 const struct file_operations proc_pagemap_operations = { 2836 .llseek = mem_lseek, /* borrow this */ 2837 .read = pagemap_read, 2838 .open = pagemap_open, 2839 .release = pagemap_release, 2840 .unlocked_ioctl = do_pagemap_cmd, 2841 .compat_ioctl = do_pagemap_cmd, 2842 }; 2843 #endif /* CONFIG_PROC_PAGE_MONITOR */ 2844 2845 #ifdef CONFIG_NUMA 2846 2847 struct numa_maps { 2848 unsigned long pages; 2849 unsigned long anon; 2850 unsigned long active; 2851 unsigned long writeback; 2852 unsigned long mapcount_max; 2853 unsigned long dirty; 2854 unsigned long swapcache; 2855 unsigned long node[MAX_NUMNODES]; 2856 }; 2857 2858 struct numa_maps_private { 2859 struct proc_maps_private proc_maps; 2860 struct numa_maps md; 2861 }; 2862 2863 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 2864 unsigned long nr_pages) 2865 { 2866 struct folio *folio = page_folio(page); 2867 int count = folio_precise_page_mapcount(folio, page); 2868 2869 md->pages += nr_pages; 2870 if (pte_dirty || folio_test_dirty(folio)) 2871 md->dirty += nr_pages; 2872 2873 if (folio_test_swapcache(folio)) 2874 md->swapcache += nr_pages; 2875 2876 if (folio_test_active(folio) || folio_test_unevictable(folio)) 2877 md->active += nr_pages; 2878 2879 if (folio_test_writeback(folio)) 2880 md->writeback += nr_pages; 2881 2882 if (folio_test_anon(folio)) 2883 md->anon += nr_pages; 2884 2885 if (count > md->mapcount_max) 2886 md->mapcount_max = count; 2887 2888 md->node[folio_nid(folio)] += nr_pages; 2889 } 2890 2891 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 2892 unsigned long addr) 2893 { 2894 struct page *page; 2895 int nid; 2896 2897 if (!pte_present(pte)) 2898 return NULL; 2899 2900 page = vm_normal_page(vma, addr, pte); 2901 if (!page || is_zone_device_page(page)) 2902 return NULL; 2903 2904 if (PageReserved(page)) 2905 return NULL; 2906 2907 nid = page_to_nid(page); 2908 if (!node_isset(nid, node_states[N_MEMORY])) 2909 return NULL; 2910 2911 return page; 2912 } 2913 2914 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2915 static struct page *can_gather_numa_stats_pmd(pmd_t pmd, 2916 struct vm_area_struct *vma, 2917 unsigned long addr) 2918 { 2919 struct page *page; 2920 int nid; 2921 2922 if (!pmd_present(pmd)) 2923 return NULL; 2924 2925 page = vm_normal_page_pmd(vma, addr, pmd); 2926 if (!page) 2927 return NULL; 2928 2929 if (PageReserved(page)) 2930 return NULL; 2931 2932 nid = page_to_nid(page); 2933 if (!node_isset(nid, node_states[N_MEMORY])) 2934 return NULL; 2935 2936 return page; 2937 } 2938 #endif 2939 2940 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 2941 unsigned long end, struct mm_walk *walk) 2942 { 2943 struct numa_maps *md = walk->private; 2944 struct vm_area_struct *vma = walk->vma; 2945 spinlock_t *ptl; 2946 pte_t *orig_pte; 2947 pte_t *pte; 2948 2949 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 2950 ptl = pmd_trans_huge_lock(pmd, vma); 2951 if (ptl) { 2952 struct page *page; 2953 2954 page = can_gather_numa_stats_pmd(*pmd, vma, addr); 2955 if (page) 2956 gather_stats(page, md, pmd_dirty(*pmd), 2957 HPAGE_PMD_SIZE/PAGE_SIZE); 2958 spin_unlock(ptl); 2959 return 0; 2960 } 2961 #endif 2962 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 2963 if (!pte) { 2964 walk->action = ACTION_AGAIN; 2965 return 0; 2966 } 2967 do { 2968 pte_t ptent = ptep_get(pte); 2969 struct page *page = can_gather_numa_stats(ptent, vma, addr); 2970 if (!page) 2971 continue; 2972 gather_stats(page, md, pte_dirty(ptent), 1); 2973 2974 } while (pte++, addr += PAGE_SIZE, addr != end); 2975 pte_unmap_unlock(orig_pte, ptl); 2976 cond_resched(); 2977 return 0; 2978 } 2979 #ifdef CONFIG_HUGETLB_PAGE 2980 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2981 unsigned long addr, unsigned long end, struct mm_walk *walk) 2982 { 2983 pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte); 2984 struct numa_maps *md; 2985 struct page *page; 2986 2987 if (!pte_present(huge_pte)) 2988 return 0; 2989 2990 page = pte_page(huge_pte); 2991 2992 md = walk->private; 2993 gather_stats(page, md, pte_dirty(huge_pte), 1); 2994 return 0; 2995 } 2996 2997 #else 2998 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, 2999 unsigned long addr, unsigned long end, struct mm_walk *walk) 3000 { 3001 return 0; 3002 } 3003 #endif 3004 3005 static const struct mm_walk_ops show_numa_ops = { 3006 .hugetlb_entry = gather_hugetlb_stats, 3007 .pmd_entry = gather_pte_stats, 3008 .walk_lock = PGWALK_RDLOCK, 3009 }; 3010 3011 /* 3012 * Display pages allocated per node and memory policy via /proc. 3013 */ 3014 static int show_numa_map(struct seq_file *m, void *v) 3015 { 3016 struct numa_maps_private *numa_priv = m->private; 3017 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 3018 struct vm_area_struct *vma = v; 3019 struct numa_maps *md = &numa_priv->md; 3020 struct file *file = vma->vm_file; 3021 struct mm_struct *mm = vma->vm_mm; 3022 char buffer[64]; 3023 struct mempolicy *pol; 3024 pgoff_t ilx; 3025 int nid; 3026 3027 if (!mm) 3028 return 0; 3029 3030 /* Ensure we start with an empty set of numa_maps statistics. */ 3031 memset(md, 0, sizeof(*md)); 3032 3033 pol = __get_vma_policy(vma, vma->vm_start, &ilx); 3034 if (pol) { 3035 mpol_to_str(buffer, sizeof(buffer), pol); 3036 mpol_cond_put(pol); 3037 } else { 3038 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); 3039 } 3040 3041 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 3042 3043 if (file) { 3044 seq_puts(m, " file="); 3045 seq_path(m, file_user_path(file), "\n\t= "); 3046 } else if (vma_is_initial_heap(vma)) { 3047 seq_puts(m, " heap"); 3048 } else if (vma_is_initial_stack(vma)) { 3049 seq_puts(m, " stack"); 3050 } 3051 3052 if (is_vm_hugetlb_page(vma)) 3053 seq_puts(m, " huge"); 3054 3055 /* mmap_lock is held by m_start */ 3056 walk_page_vma(vma, &show_numa_ops, md); 3057 3058 if (!md->pages) 3059 goto out; 3060 3061 if (md->anon) 3062 seq_printf(m, " anon=%lu", md->anon); 3063 3064 if (md->dirty) 3065 seq_printf(m, " dirty=%lu", md->dirty); 3066 3067 if (md->pages != md->anon && md->pages != md->dirty) 3068 seq_printf(m, " mapped=%lu", md->pages); 3069 3070 if (md->mapcount_max > 1) 3071 seq_printf(m, " mapmax=%lu", md->mapcount_max); 3072 3073 if (md->swapcache) 3074 seq_printf(m, " swapcache=%lu", md->swapcache); 3075 3076 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 3077 seq_printf(m, " active=%lu", md->active); 3078 3079 if (md->writeback) 3080 seq_printf(m, " writeback=%lu", md->writeback); 3081 3082 for_each_node_state(nid, N_MEMORY) 3083 if (md->node[nid]) 3084 seq_printf(m, " N%d=%lu", nid, md->node[nid]); 3085 3086 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); 3087 out: 3088 seq_putc(m, '\n'); 3089 return 0; 3090 } 3091 3092 static const struct seq_operations proc_pid_numa_maps_op = { 3093 .start = m_start, 3094 .next = m_next, 3095 .stop = m_stop, 3096 .show = show_numa_map, 3097 }; 3098 3099 static int pid_numa_maps_open(struct inode *inode, struct file *file) 3100 { 3101 return proc_maps_open(inode, file, &proc_pid_numa_maps_op, 3102 sizeof(struct numa_maps_private)); 3103 } 3104 3105 const struct file_operations proc_pid_numa_maps_operations = { 3106 .open = pid_numa_maps_open, 3107 .read = seq_read, 3108 .llseek = seq_lseek, 3109 .release = proc_map_release, 3110 }; 3111 3112 #endif /* CONFIG_NUMA */ 3113