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 ERR_PTR(-ESRCH); 125 126 mm = mm_for_maps(priv->task); 127 if (!mm || IS_ERR(mm)) 128 return mm; 129 down_read(&mm->mmap_sem); 130 131 tail_vma = get_gate_vma(priv->task->mm); 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 if (!IS_ERR(vma)) 186 vma_stop(priv, vma); 187 if (priv->task) 188 put_task_struct(priv->task); 189 } 190 191 static int do_maps_open(struct inode *inode, struct file *file, 192 const struct seq_operations *ops) 193 { 194 struct proc_maps_private *priv; 195 int ret = -ENOMEM; 196 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 197 if (priv) { 198 priv->pid = proc_pid(inode); 199 ret = seq_open(file, ops); 200 if (!ret) { 201 struct seq_file *m = file->private_data; 202 m->private = priv; 203 } else { 204 kfree(priv); 205 } 206 } 207 return ret; 208 } 209 210 static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 211 { 212 struct mm_struct *mm = vma->vm_mm; 213 struct file *file = vma->vm_file; 214 int flags = vma->vm_flags; 215 unsigned long ino = 0; 216 unsigned long long pgoff = 0; 217 unsigned long start, end; 218 dev_t dev = 0; 219 int len; 220 221 if (file) { 222 struct inode *inode = vma->vm_file->f_path.dentry->d_inode; 223 dev = inode->i_sb->s_dev; 224 ino = inode->i_ino; 225 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 226 } 227 228 /* We don't show the stack guard page in /proc/maps */ 229 start = vma->vm_start; 230 if (stack_guard_page_start(vma, start)) 231 start += PAGE_SIZE; 232 end = vma->vm_end; 233 if (stack_guard_page_end(vma, end)) 234 end -= PAGE_SIZE; 235 236 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n", 237 start, 238 end, 239 flags & VM_READ ? 'r' : '-', 240 flags & VM_WRITE ? 'w' : '-', 241 flags & VM_EXEC ? 'x' : '-', 242 flags & VM_MAYSHARE ? 's' : 'p', 243 pgoff, 244 MAJOR(dev), MINOR(dev), ino, &len); 245 246 /* 247 * Print the dentry name for named mappings, and a 248 * special [heap] marker for the heap: 249 */ 250 if (file) { 251 pad_len_spaces(m, len); 252 seq_path(m, &file->f_path, "\n"); 253 } else { 254 const char *name = arch_vma_name(vma); 255 if (!name) { 256 if (mm) { 257 if (vma->vm_start <= mm->brk && 258 vma->vm_end >= mm->start_brk) { 259 name = "[heap]"; 260 } else if (vma->vm_start <= mm->start_stack && 261 vma->vm_end >= mm->start_stack) { 262 name = "[stack]"; 263 } 264 } else { 265 name = "[vdso]"; 266 } 267 } 268 if (name) { 269 pad_len_spaces(m, len); 270 seq_puts(m, name); 271 } 272 } 273 seq_putc(m, '\n'); 274 } 275 276 static int show_map(struct seq_file *m, void *v) 277 { 278 struct vm_area_struct *vma = v; 279 struct proc_maps_private *priv = m->private; 280 struct task_struct *task = priv->task; 281 282 show_map_vma(m, vma); 283 284 if (m->count < m->size) /* vma is copied successfully */ 285 m->version = (vma != get_gate_vma(task->mm)) 286 ? vma->vm_start : 0; 287 return 0; 288 } 289 290 static const struct seq_operations proc_pid_maps_op = { 291 .start = m_start, 292 .next = m_next, 293 .stop = m_stop, 294 .show = show_map 295 }; 296 297 static int maps_open(struct inode *inode, struct file *file) 298 { 299 return do_maps_open(inode, file, &proc_pid_maps_op); 300 } 301 302 const struct file_operations proc_maps_operations = { 303 .open = maps_open, 304 .read = seq_read, 305 .llseek = seq_lseek, 306 .release = seq_release_private, 307 }; 308 309 /* 310 * Proportional Set Size(PSS): my share of RSS. 311 * 312 * PSS of a process is the count of pages it has in memory, where each 313 * page is divided by the number of processes sharing it. So if a 314 * process has 1000 pages all to itself, and 1000 shared with one other 315 * process, its PSS will be 1500. 316 * 317 * To keep (accumulated) division errors low, we adopt a 64bit 318 * fixed-point pss counter to minimize division errors. So (pss >> 319 * PSS_SHIFT) would be the real byte count. 320 * 321 * A shift of 12 before division means (assuming 4K page size): 322 * - 1M 3-user-pages add up to 8KB errors; 323 * - supports mapcount up to 2^24, or 16M; 324 * - supports PSS up to 2^52 bytes, or 4PB. 325 */ 326 #define PSS_SHIFT 12 327 328 #ifdef CONFIG_PROC_PAGE_MONITOR 329 struct mem_size_stats { 330 struct vm_area_struct *vma; 331 unsigned long resident; 332 unsigned long shared_clean; 333 unsigned long shared_dirty; 334 unsigned long private_clean; 335 unsigned long private_dirty; 336 unsigned long referenced; 337 unsigned long anonymous; 338 unsigned long anonymous_thp; 339 unsigned long swap; 340 u64 pss; 341 }; 342 343 344 static void smaps_pte_entry(pte_t ptent, unsigned long addr, 345 unsigned long ptent_size, struct mm_walk *walk) 346 { 347 struct mem_size_stats *mss = walk->private; 348 struct vm_area_struct *vma = mss->vma; 349 struct page *page; 350 int mapcount; 351 352 if (is_swap_pte(ptent)) { 353 mss->swap += ptent_size; 354 return; 355 } 356 357 if (!pte_present(ptent)) 358 return; 359 360 page = vm_normal_page(vma, addr, ptent); 361 if (!page) 362 return; 363 364 if (PageAnon(page)) 365 mss->anonymous += ptent_size; 366 367 mss->resident += ptent_size; 368 /* Accumulate the size in pages that have been accessed. */ 369 if (pte_young(ptent) || PageReferenced(page)) 370 mss->referenced += ptent_size; 371 mapcount = page_mapcount(page); 372 if (mapcount >= 2) { 373 if (pte_dirty(ptent) || PageDirty(page)) 374 mss->shared_dirty += ptent_size; 375 else 376 mss->shared_clean += ptent_size; 377 mss->pss += (ptent_size << PSS_SHIFT) / mapcount; 378 } else { 379 if (pte_dirty(ptent) || PageDirty(page)) 380 mss->private_dirty += ptent_size; 381 else 382 mss->private_clean += ptent_size; 383 mss->pss += (ptent_size << PSS_SHIFT); 384 } 385 } 386 387 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 388 struct mm_walk *walk) 389 { 390 struct mem_size_stats *mss = walk->private; 391 struct vm_area_struct *vma = mss->vma; 392 pte_t *pte; 393 spinlock_t *ptl; 394 395 spin_lock(&walk->mm->page_table_lock); 396 if (pmd_trans_huge(*pmd)) { 397 if (pmd_trans_splitting(*pmd)) { 398 spin_unlock(&walk->mm->page_table_lock); 399 wait_split_huge_page(vma->anon_vma, pmd); 400 } else { 401 smaps_pte_entry(*(pte_t *)pmd, addr, 402 HPAGE_PMD_SIZE, walk); 403 spin_unlock(&walk->mm->page_table_lock); 404 mss->anonymous_thp += HPAGE_PMD_SIZE; 405 return 0; 406 } 407 } else { 408 spin_unlock(&walk->mm->page_table_lock); 409 } 410 /* 411 * The mmap_sem held all the way back in m_start() is what 412 * keeps khugepaged out of here and from collapsing things 413 * in here. 414 */ 415 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 416 for (; addr != end; pte++, addr += PAGE_SIZE) 417 smaps_pte_entry(*pte, addr, PAGE_SIZE, walk); 418 pte_unmap_unlock(pte - 1, ptl); 419 cond_resched(); 420 return 0; 421 } 422 423 static int show_smap(struct seq_file *m, void *v) 424 { 425 struct proc_maps_private *priv = m->private; 426 struct task_struct *task = priv->task; 427 struct vm_area_struct *vma = v; 428 struct mem_size_stats mss; 429 struct mm_walk smaps_walk = { 430 .pmd_entry = smaps_pte_range, 431 .mm = vma->vm_mm, 432 .private = &mss, 433 }; 434 435 memset(&mss, 0, sizeof mss); 436 mss.vma = vma; 437 /* mmap_sem is held in m_start */ 438 if (vma->vm_mm && !is_vm_hugetlb_page(vma)) 439 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk); 440 441 show_map_vma(m, vma); 442 443 seq_printf(m, 444 "Size: %8lu kB\n" 445 "Rss: %8lu kB\n" 446 "Pss: %8lu kB\n" 447 "Shared_Clean: %8lu kB\n" 448 "Shared_Dirty: %8lu kB\n" 449 "Private_Clean: %8lu kB\n" 450 "Private_Dirty: %8lu kB\n" 451 "Referenced: %8lu kB\n" 452 "Anonymous: %8lu kB\n" 453 "AnonHugePages: %8lu kB\n" 454 "Swap: %8lu kB\n" 455 "KernelPageSize: %8lu kB\n" 456 "MMUPageSize: %8lu kB\n" 457 "Locked: %8lu kB\n", 458 (vma->vm_end - vma->vm_start) >> 10, 459 mss.resident >> 10, 460 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), 461 mss.shared_clean >> 10, 462 mss.shared_dirty >> 10, 463 mss.private_clean >> 10, 464 mss.private_dirty >> 10, 465 mss.referenced >> 10, 466 mss.anonymous >> 10, 467 mss.anonymous_thp >> 10, 468 mss.swap >> 10, 469 vma_kernel_pagesize(vma) >> 10, 470 vma_mmu_pagesize(vma) >> 10, 471 (vma->vm_flags & VM_LOCKED) ? 472 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); 473 474 if (m->count < m->size) /* vma is copied successfully */ 475 m->version = (vma != get_gate_vma(task->mm)) 476 ? vma->vm_start : 0; 477 return 0; 478 } 479 480 static const struct seq_operations proc_pid_smaps_op = { 481 .start = m_start, 482 .next = m_next, 483 .stop = m_stop, 484 .show = show_smap 485 }; 486 487 static int smaps_open(struct inode *inode, struct file *file) 488 { 489 return do_maps_open(inode, file, &proc_pid_smaps_op); 490 } 491 492 const struct file_operations proc_smaps_operations = { 493 .open = smaps_open, 494 .read = seq_read, 495 .llseek = seq_lseek, 496 .release = seq_release_private, 497 }; 498 499 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 500 unsigned long end, struct mm_walk *walk) 501 { 502 struct vm_area_struct *vma = walk->private; 503 pte_t *pte, ptent; 504 spinlock_t *ptl; 505 struct page *page; 506 507 split_huge_page_pmd(walk->mm, pmd); 508 509 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 510 for (; addr != end; pte++, addr += PAGE_SIZE) { 511 ptent = *pte; 512 if (!pte_present(ptent)) 513 continue; 514 515 page = vm_normal_page(vma, addr, ptent); 516 if (!page) 517 continue; 518 519 /* Clear accessed and referenced bits. */ 520 ptep_test_and_clear_young(vma, addr, pte); 521 ClearPageReferenced(page); 522 } 523 pte_unmap_unlock(pte - 1, ptl); 524 cond_resched(); 525 return 0; 526 } 527 528 #define CLEAR_REFS_ALL 1 529 #define CLEAR_REFS_ANON 2 530 #define CLEAR_REFS_MAPPED 3 531 532 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 533 size_t count, loff_t *ppos) 534 { 535 struct task_struct *task; 536 char buffer[PROC_NUMBUF]; 537 struct mm_struct *mm; 538 struct vm_area_struct *vma; 539 long type; 540 541 memset(buffer, 0, sizeof(buffer)); 542 if (count > sizeof(buffer) - 1) 543 count = sizeof(buffer) - 1; 544 if (copy_from_user(buffer, buf, count)) 545 return -EFAULT; 546 if (strict_strtol(strstrip(buffer), 10, &type)) 547 return -EINVAL; 548 if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) 549 return -EINVAL; 550 task = get_proc_task(file->f_path.dentry->d_inode); 551 if (!task) 552 return -ESRCH; 553 mm = get_task_mm(task); 554 if (mm) { 555 struct mm_walk clear_refs_walk = { 556 .pmd_entry = clear_refs_pte_range, 557 .mm = mm, 558 }; 559 down_read(&mm->mmap_sem); 560 for (vma = mm->mmap; vma; vma = vma->vm_next) { 561 clear_refs_walk.private = vma; 562 if (is_vm_hugetlb_page(vma)) 563 continue; 564 /* 565 * Writing 1 to /proc/pid/clear_refs affects all pages. 566 * 567 * Writing 2 to /proc/pid/clear_refs only affects 568 * Anonymous pages. 569 * 570 * Writing 3 to /proc/pid/clear_refs only affects file 571 * mapped pages. 572 */ 573 if (type == CLEAR_REFS_ANON && vma->vm_file) 574 continue; 575 if (type == CLEAR_REFS_MAPPED && !vma->vm_file) 576 continue; 577 walk_page_range(vma->vm_start, vma->vm_end, 578 &clear_refs_walk); 579 } 580 flush_tlb_mm(mm); 581 up_read(&mm->mmap_sem); 582 mmput(mm); 583 } 584 put_task_struct(task); 585 586 return count; 587 } 588 589 const struct file_operations proc_clear_refs_operations = { 590 .write = clear_refs_write, 591 .llseek = noop_llseek, 592 }; 593 594 struct pagemapread { 595 int pos, len; 596 u64 *buffer; 597 }; 598 599 #define PM_ENTRY_BYTES sizeof(u64) 600 #define PM_STATUS_BITS 3 601 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS) 602 #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET) 603 #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK) 604 #define PM_PSHIFT_BITS 6 605 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS) 606 #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET) 607 #define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) 608 #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1) 609 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK) 610 611 #define PM_PRESENT PM_STATUS(4LL) 612 #define PM_SWAP PM_STATUS(2LL) 613 #define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) 614 #define PM_END_OF_BUFFER 1 615 616 static int add_to_pagemap(unsigned long addr, u64 pfn, 617 struct pagemapread *pm) 618 { 619 pm->buffer[pm->pos++] = pfn; 620 if (pm->pos >= pm->len) 621 return PM_END_OF_BUFFER; 622 return 0; 623 } 624 625 static int pagemap_pte_hole(unsigned long start, unsigned long end, 626 struct mm_walk *walk) 627 { 628 struct pagemapread *pm = walk->private; 629 unsigned long addr; 630 int err = 0; 631 for (addr = start; addr < end; addr += PAGE_SIZE) { 632 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm); 633 if (err) 634 break; 635 } 636 return err; 637 } 638 639 static u64 swap_pte_to_pagemap_entry(pte_t pte) 640 { 641 swp_entry_t e = pte_to_swp_entry(pte); 642 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); 643 } 644 645 static u64 pte_to_pagemap_entry(pte_t pte) 646 { 647 u64 pme = 0; 648 if (is_swap_pte(pte)) 649 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte)) 650 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP; 651 else if (pte_present(pte)) 652 pme = PM_PFRAME(pte_pfn(pte)) 653 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 654 return pme; 655 } 656 657 static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 658 struct mm_walk *walk) 659 { 660 struct vm_area_struct *vma; 661 struct pagemapread *pm = walk->private; 662 pte_t *pte; 663 int err = 0; 664 665 split_huge_page_pmd(walk->mm, pmd); 666 667 /* find the first VMA at or above 'addr' */ 668 vma = find_vma(walk->mm, addr); 669 for (; addr != end; addr += PAGE_SIZE) { 670 u64 pfn = PM_NOT_PRESENT; 671 672 /* check to see if we've left 'vma' behind 673 * and need a new, higher one */ 674 if (vma && (addr >= vma->vm_end)) 675 vma = find_vma(walk->mm, addr); 676 677 /* check that 'vma' actually covers this address, 678 * and that it isn't a huge page vma */ 679 if (vma && (vma->vm_start <= addr) && 680 !is_vm_hugetlb_page(vma)) { 681 pte = pte_offset_map(pmd, addr); 682 pfn = pte_to_pagemap_entry(*pte); 683 /* unmap before userspace copy */ 684 pte_unmap(pte); 685 } 686 err = add_to_pagemap(addr, pfn, pm); 687 if (err) 688 return err; 689 } 690 691 cond_resched(); 692 693 return err; 694 } 695 696 #ifdef CONFIG_HUGETLB_PAGE 697 static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) 698 { 699 u64 pme = 0; 700 if (pte_present(pte)) 701 pme = PM_PFRAME(pte_pfn(pte) + offset) 702 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 703 return pme; 704 } 705 706 /* This function walks within one hugetlb entry in the single call */ 707 static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, 708 unsigned long addr, unsigned long end, 709 struct mm_walk *walk) 710 { 711 struct pagemapread *pm = walk->private; 712 int err = 0; 713 u64 pfn; 714 715 for (; addr != end; addr += PAGE_SIZE) { 716 int offset = (addr & ~hmask) >> PAGE_SHIFT; 717 pfn = huge_pte_to_pagemap_entry(*pte, offset); 718 err = add_to_pagemap(addr, pfn, pm); 719 if (err) 720 return err; 721 } 722 723 cond_resched(); 724 725 return err; 726 } 727 #endif /* HUGETLB_PAGE */ 728 729 /* 730 * /proc/pid/pagemap - an array mapping virtual pages to pfns 731 * 732 * For each page in the address space, this file contains one 64-bit entry 733 * consisting of the following: 734 * 735 * Bits 0-55 page frame number (PFN) if present 736 * Bits 0-4 swap type if swapped 737 * Bits 5-55 swap offset if swapped 738 * Bits 55-60 page shift (page size = 1<<page shift) 739 * Bit 61 reserved for future use 740 * Bit 62 page swapped 741 * Bit 63 page present 742 * 743 * If the page is not present but in swap, then the PFN contains an 744 * encoding of the swap file number and the page's offset into the 745 * swap. Unmapped pages return a null PFN. This allows determining 746 * precisely which pages are mapped (or in swap) and comparing mapped 747 * pages between processes. 748 * 749 * Efficient users of this interface will use /proc/pid/maps to 750 * determine which areas of memory are actually mapped and llseek to 751 * skip over unmapped regions. 752 */ 753 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 754 #define PAGEMAP_WALK_MASK (PMD_MASK) 755 static ssize_t pagemap_read(struct file *file, char __user *buf, 756 size_t count, loff_t *ppos) 757 { 758 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 759 struct mm_struct *mm; 760 struct pagemapread pm; 761 int ret = -ESRCH; 762 struct mm_walk pagemap_walk = {}; 763 unsigned long src; 764 unsigned long svpfn; 765 unsigned long start_vaddr; 766 unsigned long end_vaddr; 767 int copied = 0; 768 769 if (!task) 770 goto out; 771 772 mm = mm_for_maps(task); 773 ret = PTR_ERR(mm); 774 if (!mm || IS_ERR(mm)) 775 goto out_task; 776 777 ret = -EINVAL; 778 /* file position must be aligned */ 779 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 780 goto out_task; 781 782 ret = 0; 783 784 if (!count) 785 goto out_task; 786 787 pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 788 pm.buffer = kmalloc(pm.len, GFP_TEMPORARY); 789 ret = -ENOMEM; 790 if (!pm.buffer) 791 goto out_mm; 792 793 pagemap_walk.pmd_entry = pagemap_pte_range; 794 pagemap_walk.pte_hole = pagemap_pte_hole; 795 #ifdef CONFIG_HUGETLB_PAGE 796 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; 797 #endif 798 pagemap_walk.mm = mm; 799 pagemap_walk.private = ± 800 801 src = *ppos; 802 svpfn = src / PM_ENTRY_BYTES; 803 start_vaddr = svpfn << PAGE_SHIFT; 804 end_vaddr = TASK_SIZE_OF(task); 805 806 /* watch out for wraparound */ 807 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT) 808 start_vaddr = end_vaddr; 809 810 /* 811 * The odds are that this will stop walking way 812 * before end_vaddr, because the length of the 813 * user buffer is tracked in "pm", and the walk 814 * will stop when we hit the end of the buffer. 815 */ 816 ret = 0; 817 while (count && (start_vaddr < end_vaddr)) { 818 int len; 819 unsigned long end; 820 821 pm.pos = 0; 822 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 823 /* overflow ? */ 824 if (end < start_vaddr || end > end_vaddr) 825 end = end_vaddr; 826 down_read(&mm->mmap_sem); 827 ret = walk_page_range(start_vaddr, end, &pagemap_walk); 828 up_read(&mm->mmap_sem); 829 start_vaddr = end; 830 831 len = min(count, PM_ENTRY_BYTES * pm.pos); 832 if (copy_to_user(buf, pm.buffer, len)) { 833 ret = -EFAULT; 834 goto out_free; 835 } 836 copied += len; 837 buf += len; 838 count -= len; 839 } 840 *ppos += copied; 841 if (!ret || ret == PM_END_OF_BUFFER) 842 ret = copied; 843 844 out_free: 845 kfree(pm.buffer); 846 out_mm: 847 mmput(mm); 848 out_task: 849 put_task_struct(task); 850 out: 851 return ret; 852 } 853 854 const struct file_operations proc_pagemap_operations = { 855 .llseek = mem_lseek, /* borrow this */ 856 .read = pagemap_read, 857 }; 858 #endif /* CONFIG_PROC_PAGE_MONITOR */ 859 860 #ifdef CONFIG_NUMA 861 extern int show_numa_map(struct seq_file *m, void *v); 862 863 static const struct seq_operations proc_pid_numa_maps_op = { 864 .start = m_start, 865 .next = m_next, 866 .stop = m_stop, 867 .show = show_numa_map, 868 }; 869 870 static int numa_maps_open(struct inode *inode, struct file *file) 871 { 872 return do_maps_open(inode, file, &proc_pid_numa_maps_op); 873 } 874 875 const struct file_operations proc_numa_maps_operations = { 876 .open = numa_maps_open, 877 .read = seq_read, 878 .llseek = seq_lseek, 879 .release = seq_release_private, 880 }; 881 #endif 882