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