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