1 #include <linux/mm.h> 2 #include <linux/hugetlb.h> 3 #include <linux/huge_mm.h> 4 #include <linux/mount.h> 5 #include <linux/seq_file.h> 6 #include <linux/highmem.h> 7 #include <linux/ptrace.h> 8 #include <linux/slab.h> 9 #include <linux/pagemap.h> 10 #include <linux/mempolicy.h> 11 #include <linux/rmap.h> 12 #include <linux/swap.h> 13 #include <linux/swapops.h> 14 15 #include <asm/elf.h> 16 #include <asm/uaccess.h> 17 #include <asm/tlbflush.h> 18 #include "internal.h" 19 20 void task_mem(struct seq_file *m, struct mm_struct *mm) 21 { 22 unsigned long data, text, lib, swap; 23 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; 24 25 /* 26 * Note: to minimize their overhead, mm maintains hiwater_vm and 27 * hiwater_rss only when about to *lower* total_vm or rss. Any 28 * collector of these hiwater stats must therefore get total_vm 29 * and rss too, which will usually be the higher. Barriers? not 30 * worth the effort, such snapshots can always be inconsistent. 31 */ 32 hiwater_vm = total_vm = mm->total_vm; 33 if (hiwater_vm < mm->hiwater_vm) 34 hiwater_vm = mm->hiwater_vm; 35 hiwater_rss = total_rss = get_mm_rss(mm); 36 if (hiwater_rss < mm->hiwater_rss) 37 hiwater_rss = mm->hiwater_rss; 38 39 data = mm->total_vm - mm->shared_vm - mm->stack_vm; 40 text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10; 41 lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text; 42 swap = get_mm_counter(mm, MM_SWAPENTS); 43 seq_printf(m, 44 "VmPeak:\t%8lu kB\n" 45 "VmSize:\t%8lu kB\n" 46 "VmLck:\t%8lu kB\n" 47 "VmHWM:\t%8lu kB\n" 48 "VmRSS:\t%8lu kB\n" 49 "VmData:\t%8lu kB\n" 50 "VmStk:\t%8lu kB\n" 51 "VmExe:\t%8lu kB\n" 52 "VmLib:\t%8lu kB\n" 53 "VmPTE:\t%8lu kB\n" 54 "VmSwap:\t%8lu kB\n", 55 hiwater_vm << (PAGE_SHIFT-10), 56 (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10), 57 mm->locked_vm << (PAGE_SHIFT-10), 58 hiwater_rss << (PAGE_SHIFT-10), 59 total_rss << (PAGE_SHIFT-10), 60 data << (PAGE_SHIFT-10), 61 mm->stack_vm << (PAGE_SHIFT-10), text, lib, 62 (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10, 63 swap << (PAGE_SHIFT-10)); 64 } 65 66 unsigned long task_vsize(struct mm_struct *mm) 67 { 68 return PAGE_SIZE * mm->total_vm; 69 } 70 71 unsigned long task_statm(struct mm_struct *mm, 72 unsigned long *shared, unsigned long *text, 73 unsigned long *data, unsigned long *resident) 74 { 75 *shared = get_mm_counter(mm, MM_FILEPAGES); 76 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 77 >> PAGE_SHIFT; 78 *data = mm->total_vm - mm->shared_vm; 79 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); 80 return mm->total_vm; 81 } 82 83 static void pad_len_spaces(struct seq_file *m, int len) 84 { 85 len = 25 + sizeof(void*) * 6 - len; 86 if (len < 1) 87 len = 1; 88 seq_printf(m, "%*c", len, ' '); 89 } 90 91 static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma) 92 { 93 if (vma && vma != priv->tail_vma) { 94 struct mm_struct *mm = vma->vm_mm; 95 up_read(&mm->mmap_sem); 96 mmput(mm); 97 } 98 } 99 100 static void *m_start(struct seq_file *m, loff_t *pos) 101 { 102 struct proc_maps_private *priv = m->private; 103 unsigned long last_addr = m->version; 104 struct mm_struct *mm; 105 struct vm_area_struct *vma, *tail_vma = NULL; 106 loff_t l = *pos; 107 108 /* Clear the per syscall fields in priv */ 109 priv->task = NULL; 110 priv->tail_vma = NULL; 111 112 /* 113 * We remember last_addr rather than next_addr to hit with 114 * mmap_cache most of the time. We have zero last_addr at 115 * the beginning and also after lseek. We will have -1 last_addr 116 * after the end of the vmas. 117 */ 118 119 if (last_addr == -1UL) 120 return NULL; 121 122 priv->task = get_pid_task(priv->pid, PIDTYPE_PID); 123 if (!priv->task) 124 return NULL; 125 126 mm = mm_for_maps(priv->task); 127 if (!mm) 128 return NULL; 129 down_read(&mm->mmap_sem); 130 131 tail_vma = get_gate_vma(priv->task); 132 priv->tail_vma = tail_vma; 133 134 /* Start with last addr hint */ 135 vma = find_vma(mm, last_addr); 136 if (last_addr && vma) { 137 vma = vma->vm_next; 138 goto out; 139 } 140 141 /* 142 * Check the vma index is within the range and do 143 * sequential scan until m_index. 144 */ 145 vma = NULL; 146 if ((unsigned long)l < mm->map_count) { 147 vma = mm->mmap; 148 while (l-- && vma) 149 vma = vma->vm_next; 150 goto out; 151 } 152 153 if (l != mm->map_count) 154 tail_vma = NULL; /* After gate vma */ 155 156 out: 157 if (vma) 158 return vma; 159 160 /* End of vmas has been reached */ 161 m->version = (tail_vma != NULL)? 0: -1UL; 162 up_read(&mm->mmap_sem); 163 mmput(mm); 164 return tail_vma; 165 } 166 167 static void *m_next(struct seq_file *m, void *v, loff_t *pos) 168 { 169 struct proc_maps_private *priv = m->private; 170 struct vm_area_struct *vma = v; 171 struct vm_area_struct *tail_vma = priv->tail_vma; 172 173 (*pos)++; 174 if (vma && (vma != tail_vma) && vma->vm_next) 175 return vma->vm_next; 176 vma_stop(priv, vma); 177 return (vma != tail_vma)? tail_vma: NULL; 178 } 179 180 static void m_stop(struct seq_file *m, void *v) 181 { 182 struct proc_maps_private *priv = m->private; 183 struct vm_area_struct *vma = v; 184 185 vma_stop(priv, vma); 186 if (priv->task) 187 put_task_struct(priv->task); 188 } 189 190 static int do_maps_open(struct inode *inode, struct file *file, 191 const struct seq_operations *ops) 192 { 193 struct proc_maps_private *priv; 194 int ret = -ENOMEM; 195 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 196 if (priv) { 197 priv->pid = proc_pid(inode); 198 ret = seq_open(file, ops); 199 if (!ret) { 200 struct seq_file *m = file->private_data; 201 m->private = priv; 202 } else { 203 kfree(priv); 204 } 205 } 206 return ret; 207 } 208 209 static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 210 { 211 struct mm_struct *mm = vma->vm_mm; 212 struct file *file = vma->vm_file; 213 int flags = vma->vm_flags; 214 unsigned long ino = 0; 215 unsigned long long pgoff = 0; 216 unsigned long start; 217 dev_t dev = 0; 218 int len; 219 220 if (file) { 221 struct inode *inode = vma->vm_file->f_path.dentry->d_inode; 222 dev = inode->i_sb->s_dev; 223 ino = inode->i_ino; 224 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 225 } 226 227 /* We don't show the stack guard page in /proc/maps */ 228 start = vma->vm_start; 229 if (vma->vm_flags & VM_GROWSDOWN) 230 if (!vma_stack_continue(vma->vm_prev, vma->vm_start)) 231 start += PAGE_SIZE; 232 233 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n", 234 start, 235 vma->vm_end, 236 flags & VM_READ ? 'r' : '-', 237 flags & VM_WRITE ? 'w' : '-', 238 flags & VM_EXEC ? 'x' : '-', 239 flags & VM_MAYSHARE ? 's' : 'p', 240 pgoff, 241 MAJOR(dev), MINOR(dev), ino, &len); 242 243 /* 244 * Print the dentry name for named mappings, and a 245 * special [heap] marker for the heap: 246 */ 247 if (file) { 248 pad_len_spaces(m, len); 249 seq_path(m, &file->f_path, "\n"); 250 } else { 251 const char *name = arch_vma_name(vma); 252 if (!name) { 253 if (mm) { 254 if (vma->vm_start <= mm->start_brk && 255 vma->vm_end >= mm->brk) { 256 name = "[heap]"; 257 } else if (vma->vm_start <= mm->start_stack && 258 vma->vm_end >= mm->start_stack) { 259 name = "[stack]"; 260 } 261 } else { 262 name = "[vdso]"; 263 } 264 } 265 if (name) { 266 pad_len_spaces(m, len); 267 seq_puts(m, name); 268 } 269 } 270 seq_putc(m, '\n'); 271 } 272 273 static int show_map(struct seq_file *m, void *v) 274 { 275 struct vm_area_struct *vma = v; 276 struct proc_maps_private *priv = m->private; 277 struct task_struct *task = priv->task; 278 279 show_map_vma(m, vma); 280 281 if (m->count < m->size) /* vma is copied successfully */ 282 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0; 283 return 0; 284 } 285 286 static const struct seq_operations proc_pid_maps_op = { 287 .start = m_start, 288 .next = m_next, 289 .stop = m_stop, 290 .show = show_map 291 }; 292 293 static int maps_open(struct inode *inode, struct file *file) 294 { 295 return do_maps_open(inode, file, &proc_pid_maps_op); 296 } 297 298 const struct file_operations proc_maps_operations = { 299 .open = maps_open, 300 .read = seq_read, 301 .llseek = seq_lseek, 302 .release = seq_release_private, 303 }; 304 305 /* 306 * Proportional Set Size(PSS): my share of RSS. 307 * 308 * PSS of a process is the count of pages it has in memory, where each 309 * page is divided by the number of processes sharing it. So if a 310 * process has 1000 pages all to itself, and 1000 shared with one other 311 * process, its PSS will be 1500. 312 * 313 * To keep (accumulated) division errors low, we adopt a 64bit 314 * fixed-point pss counter to minimize division errors. So (pss >> 315 * PSS_SHIFT) would be the real byte count. 316 * 317 * A shift of 12 before division means (assuming 4K page size): 318 * - 1M 3-user-pages add up to 8KB errors; 319 * - supports mapcount up to 2^24, or 16M; 320 * - supports PSS up to 2^52 bytes, or 4PB. 321 */ 322 #define PSS_SHIFT 12 323 324 #ifdef CONFIG_PROC_PAGE_MONITOR 325 struct mem_size_stats { 326 struct vm_area_struct *vma; 327 unsigned long resident; 328 unsigned long shared_clean; 329 unsigned long shared_dirty; 330 unsigned long private_clean; 331 unsigned long private_dirty; 332 unsigned long referenced; 333 unsigned long anonymous; 334 unsigned long anonymous_thp; 335 unsigned long swap; 336 u64 pss; 337 }; 338 339 340 static void smaps_pte_entry(pte_t ptent, unsigned long addr, 341 unsigned long ptent_size, struct mm_walk *walk) 342 { 343 struct mem_size_stats *mss = walk->private; 344 struct vm_area_struct *vma = mss->vma; 345 struct page *page; 346 int mapcount; 347 348 if (is_swap_pte(ptent)) { 349 mss->swap += ptent_size; 350 return; 351 } 352 353 if (!pte_present(ptent)) 354 return; 355 356 page = vm_normal_page(vma, addr, ptent); 357 if (!page) 358 return; 359 360 if (PageAnon(page)) 361 mss->anonymous += ptent_size; 362 363 mss->resident += ptent_size; 364 /* Accumulate the size in pages that have been accessed. */ 365 if (pte_young(ptent) || PageReferenced(page)) 366 mss->referenced += ptent_size; 367 mapcount = page_mapcount(page); 368 if (mapcount >= 2) { 369 if (pte_dirty(ptent) || PageDirty(page)) 370 mss->shared_dirty += ptent_size; 371 else 372 mss->shared_clean += ptent_size; 373 mss->pss += (ptent_size << PSS_SHIFT) / mapcount; 374 } else { 375 if (pte_dirty(ptent) || PageDirty(page)) 376 mss->private_dirty += ptent_size; 377 else 378 mss->private_clean += ptent_size; 379 mss->pss += (ptent_size << PSS_SHIFT); 380 } 381 } 382 383 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 384 struct mm_walk *walk) 385 { 386 struct mem_size_stats *mss = walk->private; 387 struct vm_area_struct *vma = mss->vma; 388 pte_t *pte; 389 spinlock_t *ptl; 390 391 spin_lock(&walk->mm->page_table_lock); 392 if (pmd_trans_huge(*pmd)) { 393 if (pmd_trans_splitting(*pmd)) { 394 spin_unlock(&walk->mm->page_table_lock); 395 wait_split_huge_page(vma->anon_vma, pmd); 396 } else { 397 smaps_pte_entry(*(pte_t *)pmd, addr, 398 HPAGE_PMD_SIZE, walk); 399 spin_unlock(&walk->mm->page_table_lock); 400 mss->anonymous_thp += HPAGE_PMD_SIZE; 401 return 0; 402 } 403 } else { 404 spin_unlock(&walk->mm->page_table_lock); 405 } 406 /* 407 * The mmap_sem held all the way back in m_start() is what 408 * keeps khugepaged out of here and from collapsing things 409 * in here. 410 */ 411 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 412 for (; addr != end; pte++, addr += PAGE_SIZE) 413 smaps_pte_entry(*pte, addr, PAGE_SIZE, walk); 414 pte_unmap_unlock(pte - 1, ptl); 415 cond_resched(); 416 return 0; 417 } 418 419 static int show_smap(struct seq_file *m, void *v) 420 { 421 struct proc_maps_private *priv = m->private; 422 struct task_struct *task = priv->task; 423 struct vm_area_struct *vma = v; 424 struct mem_size_stats mss; 425 struct mm_walk smaps_walk = { 426 .pmd_entry = smaps_pte_range, 427 .mm = vma->vm_mm, 428 .private = &mss, 429 }; 430 431 memset(&mss, 0, sizeof mss); 432 mss.vma = vma; 433 /* mmap_sem is held in m_start */ 434 if (vma->vm_mm && !is_vm_hugetlb_page(vma)) 435 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk); 436 437 show_map_vma(m, vma); 438 439 seq_printf(m, 440 "Size: %8lu kB\n" 441 "Rss: %8lu kB\n" 442 "Pss: %8lu kB\n" 443 "Shared_Clean: %8lu kB\n" 444 "Shared_Dirty: %8lu kB\n" 445 "Private_Clean: %8lu kB\n" 446 "Private_Dirty: %8lu kB\n" 447 "Referenced: %8lu kB\n" 448 "Anonymous: %8lu kB\n" 449 "AnonHugePages: %8lu kB\n" 450 "Swap: %8lu kB\n" 451 "KernelPageSize: %8lu kB\n" 452 "MMUPageSize: %8lu kB\n" 453 "Locked: %8lu kB\n", 454 (vma->vm_end - vma->vm_start) >> 10, 455 mss.resident >> 10, 456 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), 457 mss.shared_clean >> 10, 458 mss.shared_dirty >> 10, 459 mss.private_clean >> 10, 460 mss.private_dirty >> 10, 461 mss.referenced >> 10, 462 mss.anonymous >> 10, 463 mss.anonymous_thp >> 10, 464 mss.swap >> 10, 465 vma_kernel_pagesize(vma) >> 10, 466 vma_mmu_pagesize(vma) >> 10, 467 (vma->vm_flags & VM_LOCKED) ? 468 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); 469 470 if (m->count < m->size) /* vma is copied successfully */ 471 m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0; 472 return 0; 473 } 474 475 static const struct seq_operations proc_pid_smaps_op = { 476 .start = m_start, 477 .next = m_next, 478 .stop = m_stop, 479 .show = show_smap 480 }; 481 482 static int smaps_open(struct inode *inode, struct file *file) 483 { 484 return do_maps_open(inode, file, &proc_pid_smaps_op); 485 } 486 487 const struct file_operations proc_smaps_operations = { 488 .open = smaps_open, 489 .read = seq_read, 490 .llseek = seq_lseek, 491 .release = seq_release_private, 492 }; 493 494 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 495 unsigned long end, struct mm_walk *walk) 496 { 497 struct vm_area_struct *vma = walk->private; 498 pte_t *pte, ptent; 499 spinlock_t *ptl; 500 struct page *page; 501 502 split_huge_page_pmd(walk->mm, pmd); 503 504 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 505 for (; addr != end; pte++, addr += PAGE_SIZE) { 506 ptent = *pte; 507 if (!pte_present(ptent)) 508 continue; 509 510 page = vm_normal_page(vma, addr, ptent); 511 if (!page) 512 continue; 513 514 /* Clear accessed and referenced bits. */ 515 ptep_test_and_clear_young(vma, addr, pte); 516 ClearPageReferenced(page); 517 } 518 pte_unmap_unlock(pte - 1, ptl); 519 cond_resched(); 520 return 0; 521 } 522 523 #define CLEAR_REFS_ALL 1 524 #define CLEAR_REFS_ANON 2 525 #define CLEAR_REFS_MAPPED 3 526 527 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 528 size_t count, loff_t *ppos) 529 { 530 struct task_struct *task; 531 char buffer[PROC_NUMBUF]; 532 struct mm_struct *mm; 533 struct vm_area_struct *vma; 534 long type; 535 536 memset(buffer, 0, sizeof(buffer)); 537 if (count > sizeof(buffer) - 1) 538 count = sizeof(buffer) - 1; 539 if (copy_from_user(buffer, buf, count)) 540 return -EFAULT; 541 if (strict_strtol(strstrip(buffer), 10, &type)) 542 return -EINVAL; 543 if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) 544 return -EINVAL; 545 task = get_proc_task(file->f_path.dentry->d_inode); 546 if (!task) 547 return -ESRCH; 548 mm = get_task_mm(task); 549 if (mm) { 550 struct mm_walk clear_refs_walk = { 551 .pmd_entry = clear_refs_pte_range, 552 .mm = mm, 553 }; 554 down_read(&mm->mmap_sem); 555 for (vma = mm->mmap; vma; vma = vma->vm_next) { 556 clear_refs_walk.private = vma; 557 if (is_vm_hugetlb_page(vma)) 558 continue; 559 /* 560 * Writing 1 to /proc/pid/clear_refs affects all pages. 561 * 562 * Writing 2 to /proc/pid/clear_refs only affects 563 * Anonymous pages. 564 * 565 * Writing 3 to /proc/pid/clear_refs only affects file 566 * mapped pages. 567 */ 568 if (type == CLEAR_REFS_ANON && vma->vm_file) 569 continue; 570 if (type == CLEAR_REFS_MAPPED && !vma->vm_file) 571 continue; 572 walk_page_range(vma->vm_start, vma->vm_end, 573 &clear_refs_walk); 574 } 575 flush_tlb_mm(mm); 576 up_read(&mm->mmap_sem); 577 mmput(mm); 578 } 579 put_task_struct(task); 580 581 return count; 582 } 583 584 const struct file_operations proc_clear_refs_operations = { 585 .write = clear_refs_write, 586 .llseek = noop_llseek, 587 }; 588 589 struct pagemapread { 590 int pos, len; 591 u64 *buffer; 592 }; 593 594 #define PM_ENTRY_BYTES sizeof(u64) 595 #define PM_STATUS_BITS 3 596 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS) 597 #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET) 598 #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK) 599 #define PM_PSHIFT_BITS 6 600 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS) 601 #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET) 602 #define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) 603 #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1) 604 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK) 605 606 #define PM_PRESENT PM_STATUS(4LL) 607 #define PM_SWAP PM_STATUS(2LL) 608 #define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) 609 #define PM_END_OF_BUFFER 1 610 611 static int add_to_pagemap(unsigned long addr, u64 pfn, 612 struct pagemapread *pm) 613 { 614 pm->buffer[pm->pos++] = pfn; 615 if (pm->pos >= pm->len) 616 return PM_END_OF_BUFFER; 617 return 0; 618 } 619 620 static int pagemap_pte_hole(unsigned long start, unsigned long end, 621 struct mm_walk *walk) 622 { 623 struct pagemapread *pm = walk->private; 624 unsigned long addr; 625 int err = 0; 626 for (addr = start; addr < end; addr += PAGE_SIZE) { 627 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm); 628 if (err) 629 break; 630 } 631 return err; 632 } 633 634 static u64 swap_pte_to_pagemap_entry(pte_t pte) 635 { 636 swp_entry_t e = pte_to_swp_entry(pte); 637 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); 638 } 639 640 static u64 pte_to_pagemap_entry(pte_t pte) 641 { 642 u64 pme = 0; 643 if (is_swap_pte(pte)) 644 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte)) 645 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP; 646 else if (pte_present(pte)) 647 pme = PM_PFRAME(pte_pfn(pte)) 648 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 649 return pme; 650 } 651 652 static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 653 struct mm_walk *walk) 654 { 655 struct vm_area_struct *vma; 656 struct pagemapread *pm = walk->private; 657 pte_t *pte; 658 int err = 0; 659 660 split_huge_page_pmd(walk->mm, pmd); 661 662 /* find the first VMA at or above 'addr' */ 663 vma = find_vma(walk->mm, addr); 664 for (; addr != end; addr += PAGE_SIZE) { 665 u64 pfn = PM_NOT_PRESENT; 666 667 /* check to see if we've left 'vma' behind 668 * and need a new, higher one */ 669 if (vma && (addr >= vma->vm_end)) 670 vma = find_vma(walk->mm, addr); 671 672 /* check that 'vma' actually covers this address, 673 * and that it isn't a huge page vma */ 674 if (vma && (vma->vm_start <= addr) && 675 !is_vm_hugetlb_page(vma)) { 676 pte = pte_offset_map(pmd, addr); 677 pfn = pte_to_pagemap_entry(*pte); 678 /* unmap before userspace copy */ 679 pte_unmap(pte); 680 } 681 err = add_to_pagemap(addr, pfn, pm); 682 if (err) 683 return err; 684 } 685 686 cond_resched(); 687 688 return err; 689 } 690 691 #ifdef CONFIG_HUGETLB_PAGE 692 static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) 693 { 694 u64 pme = 0; 695 if (pte_present(pte)) 696 pme = PM_PFRAME(pte_pfn(pte) + offset) 697 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 698 return pme; 699 } 700 701 /* This function walks within one hugetlb entry in the single call */ 702 static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, 703 unsigned long addr, unsigned long end, 704 struct mm_walk *walk) 705 { 706 struct pagemapread *pm = walk->private; 707 int err = 0; 708 u64 pfn; 709 710 for (; addr != end; addr += PAGE_SIZE) { 711 int offset = (addr & ~hmask) >> PAGE_SHIFT; 712 pfn = huge_pte_to_pagemap_entry(*pte, offset); 713 err = add_to_pagemap(addr, pfn, pm); 714 if (err) 715 return err; 716 } 717 718 cond_resched(); 719 720 return err; 721 } 722 #endif /* HUGETLB_PAGE */ 723 724 /* 725 * /proc/pid/pagemap - an array mapping virtual pages to pfns 726 * 727 * For each page in the address space, this file contains one 64-bit entry 728 * consisting of the following: 729 * 730 * Bits 0-55 page frame number (PFN) if present 731 * Bits 0-4 swap type if swapped 732 * Bits 5-55 swap offset if swapped 733 * Bits 55-60 page shift (page size = 1<<page shift) 734 * Bit 61 reserved for future use 735 * Bit 62 page swapped 736 * Bit 63 page present 737 * 738 * If the page is not present but in swap, then the PFN contains an 739 * encoding of the swap file number and the page's offset into the 740 * swap. Unmapped pages return a null PFN. This allows determining 741 * precisely which pages are mapped (or in swap) and comparing mapped 742 * pages between processes. 743 * 744 * Efficient users of this interface will use /proc/pid/maps to 745 * determine which areas of memory are actually mapped and llseek to 746 * skip over unmapped regions. 747 */ 748 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 749 #define PAGEMAP_WALK_MASK (PMD_MASK) 750 static ssize_t pagemap_read(struct file *file, char __user *buf, 751 size_t count, loff_t *ppos) 752 { 753 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 754 struct mm_struct *mm; 755 struct pagemapread pm; 756 int ret = -ESRCH; 757 struct mm_walk pagemap_walk = {}; 758 unsigned long src; 759 unsigned long svpfn; 760 unsigned long start_vaddr; 761 unsigned long end_vaddr; 762 int copied = 0; 763 764 if (!task) 765 goto out; 766 767 ret = -EACCES; 768 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 769 goto out_task; 770 771 ret = -EINVAL; 772 /* file position must be aligned */ 773 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 774 goto out_task; 775 776 ret = 0; 777 778 if (!count) 779 goto out_task; 780 781 mm = get_task_mm(task); 782 if (!mm) 783 goto out_task; 784 785 pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 786 pm.buffer = kmalloc(pm.len, GFP_TEMPORARY); 787 ret = -ENOMEM; 788 if (!pm.buffer) 789 goto out_mm; 790 791 pagemap_walk.pmd_entry = pagemap_pte_range; 792 pagemap_walk.pte_hole = pagemap_pte_hole; 793 #ifdef CONFIG_HUGETLB_PAGE 794 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; 795 #endif 796 pagemap_walk.mm = mm; 797 pagemap_walk.private = ± 798 799 src = *ppos; 800 svpfn = src / PM_ENTRY_BYTES; 801 start_vaddr = svpfn << PAGE_SHIFT; 802 end_vaddr = TASK_SIZE_OF(task); 803 804 /* watch out for wraparound */ 805 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT) 806 start_vaddr = end_vaddr; 807 808 /* 809 * The odds are that this will stop walking way 810 * before end_vaddr, because the length of the 811 * user buffer is tracked in "pm", and the walk 812 * will stop when we hit the end of the buffer. 813 */ 814 ret = 0; 815 while (count && (start_vaddr < end_vaddr)) { 816 int len; 817 unsigned long end; 818 819 pm.pos = 0; 820 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 821 /* overflow ? */ 822 if (end < start_vaddr || end > end_vaddr) 823 end = end_vaddr; 824 down_read(&mm->mmap_sem); 825 ret = walk_page_range(start_vaddr, end, &pagemap_walk); 826 up_read(&mm->mmap_sem); 827 start_vaddr = end; 828 829 len = min(count, PM_ENTRY_BYTES * pm.pos); 830 if (copy_to_user(buf, pm.buffer, len)) { 831 ret = -EFAULT; 832 goto out_free; 833 } 834 copied += len; 835 buf += len; 836 count -= len; 837 } 838 *ppos += copied; 839 if (!ret || ret == PM_END_OF_BUFFER) 840 ret = copied; 841 842 out_free: 843 kfree(pm.buffer); 844 out_mm: 845 mmput(mm); 846 out_task: 847 put_task_struct(task); 848 out: 849 return ret; 850 } 851 852 const struct file_operations proc_pagemap_operations = { 853 .llseek = mem_lseek, /* borrow this */ 854 .read = pagemap_read, 855 }; 856 #endif /* CONFIG_PROC_PAGE_MONITOR */ 857 858 #ifdef CONFIG_NUMA 859 extern int show_numa_map(struct seq_file *m, void *v); 860 861 static const struct seq_operations proc_pid_numa_maps_op = { 862 .start = m_start, 863 .next = m_next, 864 .stop = m_stop, 865 .show = show_numa_map, 866 }; 867 868 static int numa_maps_open(struct inode *inode, struct file *file) 869 { 870 return do_maps_open(inode, file, &proc_pid_numa_maps_op); 871 } 872 873 const struct file_operations proc_numa_maps_operations = { 874 .open = numa_maps_open, 875 .read = seq_read, 876 .llseek = seq_lseek, 877 .release = seq_release_private, 878 }; 879 #endif 880