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 "VmPin:\t%8lu kB\n" 48 "VmHWM:\t%8lu kB\n" 49 "VmRSS:\t%8lu kB\n" 50 "VmData:\t%8lu kB\n" 51 "VmStk:\t%8lu kB\n" 52 "VmExe:\t%8lu kB\n" 53 "VmLib:\t%8lu kB\n" 54 "VmPTE:\t%8lu kB\n" 55 "VmSwap:\t%8lu kB\n", 56 hiwater_vm << (PAGE_SHIFT-10), 57 (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10), 58 mm->locked_vm << (PAGE_SHIFT-10), 59 mm->pinned_vm << (PAGE_SHIFT-10), 60 hiwater_rss << (PAGE_SHIFT-10), 61 total_rss << (PAGE_SHIFT-10), 62 data << (PAGE_SHIFT-10), 63 mm->stack_vm << (PAGE_SHIFT-10), text, lib, 64 (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10, 65 swap << (PAGE_SHIFT-10)); 66 } 67 68 unsigned long task_vsize(struct mm_struct *mm) 69 { 70 return PAGE_SIZE * mm->total_vm; 71 } 72 73 unsigned long task_statm(struct mm_struct *mm, 74 unsigned long *shared, unsigned long *text, 75 unsigned long *data, unsigned long *resident) 76 { 77 *shared = get_mm_counter(mm, MM_FILEPAGES); 78 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 79 >> PAGE_SHIFT; 80 *data = mm->total_vm - mm->shared_vm; 81 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); 82 return mm->total_vm; 83 } 84 85 static void pad_len_spaces(struct seq_file *m, int len) 86 { 87 len = 25 + sizeof(void*) * 6 - len; 88 if (len < 1) 89 len = 1; 90 seq_printf(m, "%*c", len, ' '); 91 } 92 93 static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma) 94 { 95 if (vma && vma != priv->tail_vma) { 96 struct mm_struct *mm = vma->vm_mm; 97 up_read(&mm->mmap_sem); 98 mmput(mm); 99 } 100 } 101 102 static void *m_start(struct seq_file *m, loff_t *pos) 103 { 104 struct proc_maps_private *priv = m->private; 105 unsigned long last_addr = m->version; 106 struct mm_struct *mm; 107 struct vm_area_struct *vma, *tail_vma = NULL; 108 loff_t l = *pos; 109 110 /* Clear the per syscall fields in priv */ 111 priv->task = NULL; 112 priv->tail_vma = NULL; 113 114 /* 115 * We remember last_addr rather than next_addr to hit with 116 * mmap_cache most of the time. We have zero last_addr at 117 * the beginning and also after lseek. We will have -1 last_addr 118 * after the end of the vmas. 119 */ 120 121 if (last_addr == -1UL) 122 return NULL; 123 124 priv->task = get_pid_task(priv->pid, PIDTYPE_PID); 125 if (!priv->task) 126 return ERR_PTR(-ESRCH); 127 128 mm = mm_for_maps(priv->task); 129 if (!mm || IS_ERR(mm)) 130 return mm; 131 down_read(&mm->mmap_sem); 132 133 tail_vma = get_gate_vma(priv->task->mm); 134 priv->tail_vma = tail_vma; 135 136 /* Start with last addr hint */ 137 vma = find_vma(mm, last_addr); 138 if (last_addr && vma) { 139 vma = vma->vm_next; 140 goto out; 141 } 142 143 /* 144 * Check the vma index is within the range and do 145 * sequential scan until m_index. 146 */ 147 vma = NULL; 148 if ((unsigned long)l < mm->map_count) { 149 vma = mm->mmap; 150 while (l-- && vma) 151 vma = vma->vm_next; 152 goto out; 153 } 154 155 if (l != mm->map_count) 156 tail_vma = NULL; /* After gate vma */ 157 158 out: 159 if (vma) 160 return vma; 161 162 /* End of vmas has been reached */ 163 m->version = (tail_vma != NULL)? 0: -1UL; 164 up_read(&mm->mmap_sem); 165 mmput(mm); 166 return tail_vma; 167 } 168 169 static void *m_next(struct seq_file *m, void *v, loff_t *pos) 170 { 171 struct proc_maps_private *priv = m->private; 172 struct vm_area_struct *vma = v; 173 struct vm_area_struct *tail_vma = priv->tail_vma; 174 175 (*pos)++; 176 if (vma && (vma != tail_vma) && vma->vm_next) 177 return vma->vm_next; 178 vma_stop(priv, vma); 179 return (vma != tail_vma)? tail_vma: NULL; 180 } 181 182 static void m_stop(struct seq_file *m, void *v) 183 { 184 struct proc_maps_private *priv = m->private; 185 struct vm_area_struct *vma = v; 186 187 if (!IS_ERR(vma)) 188 vma_stop(priv, vma); 189 if (priv->task) 190 put_task_struct(priv->task); 191 } 192 193 static int do_maps_open(struct inode *inode, struct file *file, 194 const struct seq_operations *ops) 195 { 196 struct proc_maps_private *priv; 197 int ret = -ENOMEM; 198 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 199 if (priv) { 200 priv->pid = proc_pid(inode); 201 ret = seq_open(file, ops); 202 if (!ret) { 203 struct seq_file *m = file->private_data; 204 m->private = priv; 205 } else { 206 kfree(priv); 207 } 208 } 209 return ret; 210 } 211 212 static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 213 { 214 struct mm_struct *mm = vma->vm_mm; 215 struct file *file = vma->vm_file; 216 vm_flags_t flags = vma->vm_flags; 217 unsigned long ino = 0; 218 unsigned long long pgoff = 0; 219 unsigned long start, end; 220 dev_t dev = 0; 221 int len; 222 223 if (file) { 224 struct inode *inode = vma->vm_file->f_path.dentry->d_inode; 225 dev = inode->i_sb->s_dev; 226 ino = inode->i_ino; 227 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; 228 } 229 230 /* We don't show the stack guard page in /proc/maps */ 231 start = vma->vm_start; 232 if (stack_guard_page_start(vma, start)) 233 start += PAGE_SIZE; 234 end = vma->vm_end; 235 if (stack_guard_page_end(vma, end)) 236 end -= PAGE_SIZE; 237 238 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n", 239 start, 240 end, 241 flags & VM_READ ? 'r' : '-', 242 flags & VM_WRITE ? 'w' : '-', 243 flags & VM_EXEC ? 'x' : '-', 244 flags & VM_MAYSHARE ? 's' : 'p', 245 pgoff, 246 MAJOR(dev), MINOR(dev), ino, &len); 247 248 /* 249 * Print the dentry name for named mappings, and a 250 * special [heap] marker for the heap: 251 */ 252 if (file) { 253 pad_len_spaces(m, len); 254 seq_path(m, &file->f_path, "\n"); 255 } else { 256 const char *name = arch_vma_name(vma); 257 if (!name) { 258 if (mm) { 259 if (vma->vm_start <= mm->brk && 260 vma->vm_end >= mm->start_brk) { 261 name = "[heap]"; 262 } else if (vma->vm_start <= mm->start_stack && 263 vma->vm_end >= mm->start_stack) { 264 name = "[stack]"; 265 } 266 } else { 267 name = "[vdso]"; 268 } 269 } 270 if (name) { 271 pad_len_spaces(m, len); 272 seq_puts(m, name); 273 } 274 } 275 seq_putc(m, '\n'); 276 } 277 278 static int show_map(struct seq_file *m, void *v) 279 { 280 struct vm_area_struct *vma = v; 281 struct proc_maps_private *priv = m->private; 282 struct task_struct *task = priv->task; 283 284 show_map_vma(m, vma); 285 286 if (m->count < m->size) /* vma is copied successfully */ 287 m->version = (vma != get_gate_vma(task->mm)) 288 ? vma->vm_start : 0; 289 return 0; 290 } 291 292 static const struct seq_operations proc_pid_maps_op = { 293 .start = m_start, 294 .next = m_next, 295 .stop = m_stop, 296 .show = show_map 297 }; 298 299 static int maps_open(struct inode *inode, struct file *file) 300 { 301 return do_maps_open(inode, file, &proc_pid_maps_op); 302 } 303 304 const struct file_operations proc_maps_operations = { 305 .open = maps_open, 306 .read = seq_read, 307 .llseek = seq_lseek, 308 .release = seq_release_private, 309 }; 310 311 /* 312 * Proportional Set Size(PSS): my share of RSS. 313 * 314 * PSS of a process is the count of pages it has in memory, where each 315 * page is divided by the number of processes sharing it. So if a 316 * process has 1000 pages all to itself, and 1000 shared with one other 317 * process, its PSS will be 1500. 318 * 319 * To keep (accumulated) division errors low, we adopt a 64bit 320 * fixed-point pss counter to minimize division errors. So (pss >> 321 * PSS_SHIFT) would be the real byte count. 322 * 323 * A shift of 12 before division means (assuming 4K page size): 324 * - 1M 3-user-pages add up to 8KB errors; 325 * - supports mapcount up to 2^24, or 16M; 326 * - supports PSS up to 2^52 bytes, or 4PB. 327 */ 328 #define PSS_SHIFT 12 329 330 #ifdef CONFIG_PROC_PAGE_MONITOR 331 struct mem_size_stats { 332 struct vm_area_struct *vma; 333 unsigned long resident; 334 unsigned long shared_clean; 335 unsigned long shared_dirty; 336 unsigned long private_clean; 337 unsigned long private_dirty; 338 unsigned long referenced; 339 unsigned long anonymous; 340 unsigned long anonymous_thp; 341 unsigned long swap; 342 u64 pss; 343 }; 344 345 346 static void smaps_pte_entry(pte_t ptent, unsigned long addr, 347 unsigned long ptent_size, struct mm_walk *walk) 348 { 349 struct mem_size_stats *mss = walk->private; 350 struct vm_area_struct *vma = mss->vma; 351 struct page *page; 352 int mapcount; 353 354 if (is_swap_pte(ptent)) { 355 mss->swap += ptent_size; 356 return; 357 } 358 359 if (!pte_present(ptent)) 360 return; 361 362 page = vm_normal_page(vma, addr, ptent); 363 if (!page) 364 return; 365 366 if (PageAnon(page)) 367 mss->anonymous += ptent_size; 368 369 mss->resident += ptent_size; 370 /* Accumulate the size in pages that have been accessed. */ 371 if (pte_young(ptent) || PageReferenced(page)) 372 mss->referenced += ptent_size; 373 mapcount = page_mapcount(page); 374 if (mapcount >= 2) { 375 if (pte_dirty(ptent) || PageDirty(page)) 376 mss->shared_dirty += ptent_size; 377 else 378 mss->shared_clean += ptent_size; 379 mss->pss += (ptent_size << PSS_SHIFT) / mapcount; 380 } else { 381 if (pte_dirty(ptent) || PageDirty(page)) 382 mss->private_dirty += ptent_size; 383 else 384 mss->private_clean += ptent_size; 385 mss->pss += (ptent_size << PSS_SHIFT); 386 } 387 } 388 389 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 390 struct mm_walk *walk) 391 { 392 struct mem_size_stats *mss = walk->private; 393 struct vm_area_struct *vma = mss->vma; 394 pte_t *pte; 395 spinlock_t *ptl; 396 397 spin_lock(&walk->mm->page_table_lock); 398 if (pmd_trans_huge(*pmd)) { 399 if (pmd_trans_splitting(*pmd)) { 400 spin_unlock(&walk->mm->page_table_lock); 401 wait_split_huge_page(vma->anon_vma, pmd); 402 } else { 403 smaps_pte_entry(*(pte_t *)pmd, addr, 404 HPAGE_PMD_SIZE, walk); 405 spin_unlock(&walk->mm->page_table_lock); 406 mss->anonymous_thp += HPAGE_PMD_SIZE; 407 return 0; 408 } 409 } else { 410 spin_unlock(&walk->mm->page_table_lock); 411 } 412 /* 413 * The mmap_sem held all the way back in m_start() is what 414 * keeps khugepaged out of here and from collapsing things 415 * in here. 416 */ 417 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 418 for (; addr != end; pte++, addr += PAGE_SIZE) 419 smaps_pte_entry(*pte, addr, PAGE_SIZE, walk); 420 pte_unmap_unlock(pte - 1, ptl); 421 cond_resched(); 422 return 0; 423 } 424 425 static int show_smap(struct seq_file *m, void *v) 426 { 427 struct proc_maps_private *priv = m->private; 428 struct task_struct *task = priv->task; 429 struct vm_area_struct *vma = v; 430 struct mem_size_stats mss; 431 struct mm_walk smaps_walk = { 432 .pmd_entry = smaps_pte_range, 433 .mm = vma->vm_mm, 434 .private = &mss, 435 }; 436 437 memset(&mss, 0, sizeof mss); 438 mss.vma = vma; 439 /* mmap_sem is held in m_start */ 440 if (vma->vm_mm && !is_vm_hugetlb_page(vma)) 441 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk); 442 443 show_map_vma(m, vma); 444 445 seq_printf(m, 446 "Size: %8lu kB\n" 447 "Rss: %8lu kB\n" 448 "Pss: %8lu kB\n" 449 "Shared_Clean: %8lu kB\n" 450 "Shared_Dirty: %8lu kB\n" 451 "Private_Clean: %8lu kB\n" 452 "Private_Dirty: %8lu kB\n" 453 "Referenced: %8lu kB\n" 454 "Anonymous: %8lu kB\n" 455 "AnonHugePages: %8lu kB\n" 456 "Swap: %8lu kB\n" 457 "KernelPageSize: %8lu kB\n" 458 "MMUPageSize: %8lu kB\n" 459 "Locked: %8lu kB\n", 460 (vma->vm_end - vma->vm_start) >> 10, 461 mss.resident >> 10, 462 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), 463 mss.shared_clean >> 10, 464 mss.shared_dirty >> 10, 465 mss.private_clean >> 10, 466 mss.private_dirty >> 10, 467 mss.referenced >> 10, 468 mss.anonymous >> 10, 469 mss.anonymous_thp >> 10, 470 mss.swap >> 10, 471 vma_kernel_pagesize(vma) >> 10, 472 vma_mmu_pagesize(vma) >> 10, 473 (vma->vm_flags & VM_LOCKED) ? 474 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); 475 476 if (m->count < m->size) /* vma is copied successfully */ 477 m->version = (vma != get_gate_vma(task->mm)) 478 ? vma->vm_start : 0; 479 return 0; 480 } 481 482 static const struct seq_operations proc_pid_smaps_op = { 483 .start = m_start, 484 .next = m_next, 485 .stop = m_stop, 486 .show = show_smap 487 }; 488 489 static int smaps_open(struct inode *inode, struct file *file) 490 { 491 return do_maps_open(inode, file, &proc_pid_smaps_op); 492 } 493 494 const struct file_operations proc_smaps_operations = { 495 .open = smaps_open, 496 .read = seq_read, 497 .llseek = seq_lseek, 498 .release = seq_release_private, 499 }; 500 501 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, 502 unsigned long end, struct mm_walk *walk) 503 { 504 struct vm_area_struct *vma = walk->private; 505 pte_t *pte, ptent; 506 spinlock_t *ptl; 507 struct page *page; 508 509 split_huge_page_pmd(walk->mm, pmd); 510 511 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 512 for (; addr != end; pte++, addr += PAGE_SIZE) { 513 ptent = *pte; 514 if (!pte_present(ptent)) 515 continue; 516 517 page = vm_normal_page(vma, addr, ptent); 518 if (!page) 519 continue; 520 521 if (PageReserved(page)) 522 continue; 523 524 /* Clear accessed and referenced bits. */ 525 ptep_test_and_clear_young(vma, addr, pte); 526 ClearPageReferenced(page); 527 } 528 pte_unmap_unlock(pte - 1, ptl); 529 cond_resched(); 530 return 0; 531 } 532 533 #define CLEAR_REFS_ALL 1 534 #define CLEAR_REFS_ANON 2 535 #define CLEAR_REFS_MAPPED 3 536 537 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 538 size_t count, loff_t *ppos) 539 { 540 struct task_struct *task; 541 char buffer[PROC_NUMBUF]; 542 struct mm_struct *mm; 543 struct vm_area_struct *vma; 544 int type; 545 int rv; 546 547 memset(buffer, 0, sizeof(buffer)); 548 if (count > sizeof(buffer) - 1) 549 count = sizeof(buffer) - 1; 550 if (copy_from_user(buffer, buf, count)) 551 return -EFAULT; 552 rv = kstrtoint(strstrip(buffer), 10, &type); 553 if (rv < 0) 554 return rv; 555 if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) 556 return -EINVAL; 557 task = get_proc_task(file->f_path.dentry->d_inode); 558 if (!task) 559 return -ESRCH; 560 mm = get_task_mm(task); 561 if (mm) { 562 struct mm_walk clear_refs_walk = { 563 .pmd_entry = clear_refs_pte_range, 564 .mm = mm, 565 }; 566 down_read(&mm->mmap_sem); 567 for (vma = mm->mmap; vma; vma = vma->vm_next) { 568 clear_refs_walk.private = vma; 569 if (is_vm_hugetlb_page(vma)) 570 continue; 571 /* 572 * Writing 1 to /proc/pid/clear_refs affects all pages. 573 * 574 * Writing 2 to /proc/pid/clear_refs only affects 575 * Anonymous pages. 576 * 577 * Writing 3 to /proc/pid/clear_refs only affects file 578 * mapped pages. 579 */ 580 if (type == CLEAR_REFS_ANON && vma->vm_file) 581 continue; 582 if (type == CLEAR_REFS_MAPPED && !vma->vm_file) 583 continue; 584 walk_page_range(vma->vm_start, vma->vm_end, 585 &clear_refs_walk); 586 } 587 flush_tlb_mm(mm); 588 up_read(&mm->mmap_sem); 589 mmput(mm); 590 } 591 put_task_struct(task); 592 593 return count; 594 } 595 596 const struct file_operations proc_clear_refs_operations = { 597 .write = clear_refs_write, 598 .llseek = noop_llseek, 599 }; 600 601 struct pagemapread { 602 int pos, len; 603 u64 *buffer; 604 }; 605 606 #define PM_ENTRY_BYTES sizeof(u64) 607 #define PM_STATUS_BITS 3 608 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS) 609 #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET) 610 #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK) 611 #define PM_PSHIFT_BITS 6 612 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS) 613 #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET) 614 #define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) 615 #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1) 616 #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK) 617 618 #define PM_PRESENT PM_STATUS(4LL) 619 #define PM_SWAP PM_STATUS(2LL) 620 #define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) 621 #define PM_END_OF_BUFFER 1 622 623 static int add_to_pagemap(unsigned long addr, u64 pfn, 624 struct pagemapread *pm) 625 { 626 pm->buffer[pm->pos++] = pfn; 627 if (pm->pos >= pm->len) 628 return PM_END_OF_BUFFER; 629 return 0; 630 } 631 632 static int pagemap_pte_hole(unsigned long start, unsigned long end, 633 struct mm_walk *walk) 634 { 635 struct pagemapread *pm = walk->private; 636 unsigned long addr; 637 int err = 0; 638 for (addr = start; addr < end; addr += PAGE_SIZE) { 639 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm); 640 if (err) 641 break; 642 } 643 return err; 644 } 645 646 static u64 swap_pte_to_pagemap_entry(pte_t pte) 647 { 648 swp_entry_t e = pte_to_swp_entry(pte); 649 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); 650 } 651 652 static u64 pte_to_pagemap_entry(pte_t pte) 653 { 654 u64 pme = 0; 655 if (is_swap_pte(pte)) 656 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte)) 657 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP; 658 else if (pte_present(pte)) 659 pme = PM_PFRAME(pte_pfn(pte)) 660 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 661 return pme; 662 } 663 664 static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 665 struct mm_walk *walk) 666 { 667 struct vm_area_struct *vma; 668 struct pagemapread *pm = walk->private; 669 pte_t *pte; 670 int err = 0; 671 672 split_huge_page_pmd(walk->mm, pmd); 673 674 /* find the first VMA at or above 'addr' */ 675 vma = find_vma(walk->mm, addr); 676 for (; addr != end; addr += PAGE_SIZE) { 677 u64 pfn = PM_NOT_PRESENT; 678 679 /* check to see if we've left 'vma' behind 680 * and need a new, higher one */ 681 if (vma && (addr >= vma->vm_end)) 682 vma = find_vma(walk->mm, addr); 683 684 /* check that 'vma' actually covers this address, 685 * and that it isn't a huge page vma */ 686 if (vma && (vma->vm_start <= addr) && 687 !is_vm_hugetlb_page(vma)) { 688 pte = pte_offset_map(pmd, addr); 689 pfn = pte_to_pagemap_entry(*pte); 690 /* unmap before userspace copy */ 691 pte_unmap(pte); 692 } 693 err = add_to_pagemap(addr, pfn, pm); 694 if (err) 695 return err; 696 } 697 698 cond_resched(); 699 700 return err; 701 } 702 703 #ifdef CONFIG_HUGETLB_PAGE 704 static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) 705 { 706 u64 pme = 0; 707 if (pte_present(pte)) 708 pme = PM_PFRAME(pte_pfn(pte) + offset) 709 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; 710 return pme; 711 } 712 713 /* This function walks within one hugetlb entry in the single call */ 714 static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, 715 unsigned long addr, unsigned long end, 716 struct mm_walk *walk) 717 { 718 struct pagemapread *pm = walk->private; 719 int err = 0; 720 u64 pfn; 721 722 for (; addr != end; addr += PAGE_SIZE) { 723 int offset = (addr & ~hmask) >> PAGE_SHIFT; 724 pfn = huge_pte_to_pagemap_entry(*pte, offset); 725 err = add_to_pagemap(addr, pfn, pm); 726 if (err) 727 return err; 728 } 729 730 cond_resched(); 731 732 return err; 733 } 734 #endif /* HUGETLB_PAGE */ 735 736 /* 737 * /proc/pid/pagemap - an array mapping virtual pages to pfns 738 * 739 * For each page in the address space, this file contains one 64-bit entry 740 * consisting of the following: 741 * 742 * Bits 0-55 page frame number (PFN) if present 743 * Bits 0-4 swap type if swapped 744 * Bits 5-55 swap offset if swapped 745 * Bits 55-60 page shift (page size = 1<<page shift) 746 * Bit 61 reserved for future use 747 * Bit 62 page swapped 748 * Bit 63 page present 749 * 750 * If the page is not present but in swap, then the PFN contains an 751 * encoding of the swap file number and the page's offset into the 752 * swap. Unmapped pages return a null PFN. This allows determining 753 * precisely which pages are mapped (or in swap) and comparing mapped 754 * pages between processes. 755 * 756 * Efficient users of this interface will use /proc/pid/maps to 757 * determine which areas of memory are actually mapped and llseek to 758 * skip over unmapped regions. 759 */ 760 #define PAGEMAP_WALK_SIZE (PMD_SIZE) 761 #define PAGEMAP_WALK_MASK (PMD_MASK) 762 static ssize_t pagemap_read(struct file *file, char __user *buf, 763 size_t count, loff_t *ppos) 764 { 765 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 766 struct mm_struct *mm; 767 struct pagemapread pm; 768 int ret = -ESRCH; 769 struct mm_walk pagemap_walk = {}; 770 unsigned long src; 771 unsigned long svpfn; 772 unsigned long start_vaddr; 773 unsigned long end_vaddr; 774 int copied = 0; 775 776 if (!task) 777 goto out; 778 779 ret = -EINVAL; 780 /* file position must be aligned */ 781 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) 782 goto out_task; 783 784 ret = 0; 785 if (!count) 786 goto out_task; 787 788 pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); 789 pm.buffer = kmalloc(pm.len, GFP_TEMPORARY); 790 ret = -ENOMEM; 791 if (!pm.buffer) 792 goto out_task; 793 794 mm = mm_for_maps(task); 795 ret = PTR_ERR(mm); 796 if (!mm || IS_ERR(mm)) 797 goto out_free; 798 799 pagemap_walk.pmd_entry = pagemap_pte_range; 800 pagemap_walk.pte_hole = pagemap_pte_hole; 801 #ifdef CONFIG_HUGETLB_PAGE 802 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; 803 #endif 804 pagemap_walk.mm = mm; 805 pagemap_walk.private = ± 806 807 src = *ppos; 808 svpfn = src / PM_ENTRY_BYTES; 809 start_vaddr = svpfn << PAGE_SHIFT; 810 end_vaddr = TASK_SIZE_OF(task); 811 812 /* watch out for wraparound */ 813 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT) 814 start_vaddr = end_vaddr; 815 816 /* 817 * The odds are that this will stop walking way 818 * before end_vaddr, because the length of the 819 * user buffer is tracked in "pm", and the walk 820 * will stop when we hit the end of the buffer. 821 */ 822 ret = 0; 823 while (count && (start_vaddr < end_vaddr)) { 824 int len; 825 unsigned long end; 826 827 pm.pos = 0; 828 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; 829 /* overflow ? */ 830 if (end < start_vaddr || end > end_vaddr) 831 end = end_vaddr; 832 down_read(&mm->mmap_sem); 833 ret = walk_page_range(start_vaddr, end, &pagemap_walk); 834 up_read(&mm->mmap_sem); 835 start_vaddr = end; 836 837 len = min(count, PM_ENTRY_BYTES * pm.pos); 838 if (copy_to_user(buf, pm.buffer, len)) { 839 ret = -EFAULT; 840 goto out_mm; 841 } 842 copied += len; 843 buf += len; 844 count -= len; 845 } 846 *ppos += copied; 847 if (!ret || ret == PM_END_OF_BUFFER) 848 ret = copied; 849 850 out_mm: 851 mmput(mm); 852 out_free: 853 kfree(pm.buffer); 854 out_task: 855 put_task_struct(task); 856 out: 857 return ret; 858 } 859 860 const struct file_operations proc_pagemap_operations = { 861 .llseek = mem_lseek, /* borrow this */ 862 .read = pagemap_read, 863 }; 864 #endif /* CONFIG_PROC_PAGE_MONITOR */ 865 866 #ifdef CONFIG_NUMA 867 868 struct numa_maps { 869 struct vm_area_struct *vma; 870 unsigned long pages; 871 unsigned long anon; 872 unsigned long active; 873 unsigned long writeback; 874 unsigned long mapcount_max; 875 unsigned long dirty; 876 unsigned long swapcache; 877 unsigned long node[MAX_NUMNODES]; 878 }; 879 880 struct numa_maps_private { 881 struct proc_maps_private proc_maps; 882 struct numa_maps md; 883 }; 884 885 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, 886 unsigned long nr_pages) 887 { 888 int count = page_mapcount(page); 889 890 md->pages += nr_pages; 891 if (pte_dirty || PageDirty(page)) 892 md->dirty += nr_pages; 893 894 if (PageSwapCache(page)) 895 md->swapcache += nr_pages; 896 897 if (PageActive(page) || PageUnevictable(page)) 898 md->active += nr_pages; 899 900 if (PageWriteback(page)) 901 md->writeback += nr_pages; 902 903 if (PageAnon(page)) 904 md->anon += nr_pages; 905 906 if (count > md->mapcount_max) 907 md->mapcount_max = count; 908 909 md->node[page_to_nid(page)] += nr_pages; 910 } 911 912 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, 913 unsigned long addr) 914 { 915 struct page *page; 916 int nid; 917 918 if (!pte_present(pte)) 919 return NULL; 920 921 page = vm_normal_page(vma, addr, pte); 922 if (!page) 923 return NULL; 924 925 if (PageReserved(page)) 926 return NULL; 927 928 nid = page_to_nid(page); 929 if (!node_isset(nid, node_states[N_HIGH_MEMORY])) 930 return NULL; 931 932 return page; 933 } 934 935 static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 936 unsigned long end, struct mm_walk *walk) 937 { 938 struct numa_maps *md; 939 spinlock_t *ptl; 940 pte_t *orig_pte; 941 pte_t *pte; 942 943 md = walk->private; 944 spin_lock(&walk->mm->page_table_lock); 945 if (pmd_trans_huge(*pmd)) { 946 if (pmd_trans_splitting(*pmd)) { 947 spin_unlock(&walk->mm->page_table_lock); 948 wait_split_huge_page(md->vma->anon_vma, pmd); 949 } else { 950 pte_t huge_pte = *(pte_t *)pmd; 951 struct page *page; 952 953 page = can_gather_numa_stats(huge_pte, md->vma, addr); 954 if (page) 955 gather_stats(page, md, pte_dirty(huge_pte), 956 HPAGE_PMD_SIZE/PAGE_SIZE); 957 spin_unlock(&walk->mm->page_table_lock); 958 return 0; 959 } 960 } else { 961 spin_unlock(&walk->mm->page_table_lock); 962 } 963 964 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 965 do { 966 struct page *page = can_gather_numa_stats(*pte, md->vma, addr); 967 if (!page) 968 continue; 969 gather_stats(page, md, pte_dirty(*pte), 1); 970 971 } while (pte++, addr += PAGE_SIZE, addr != end); 972 pte_unmap_unlock(orig_pte, ptl); 973 return 0; 974 } 975 #ifdef CONFIG_HUGETLB_PAGE 976 static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask, 977 unsigned long addr, unsigned long end, struct mm_walk *walk) 978 { 979 struct numa_maps *md; 980 struct page *page; 981 982 if (pte_none(*pte)) 983 return 0; 984 985 page = pte_page(*pte); 986 if (!page) 987 return 0; 988 989 md = walk->private; 990 gather_stats(page, md, pte_dirty(*pte), 1); 991 return 0; 992 } 993 994 #else 995 static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask, 996 unsigned long addr, unsigned long end, struct mm_walk *walk) 997 { 998 return 0; 999 } 1000 #endif 1001 1002 /* 1003 * Display pages allocated per node and memory policy via /proc. 1004 */ 1005 static int show_numa_map(struct seq_file *m, void *v) 1006 { 1007 struct numa_maps_private *numa_priv = m->private; 1008 struct proc_maps_private *proc_priv = &numa_priv->proc_maps; 1009 struct vm_area_struct *vma = v; 1010 struct numa_maps *md = &numa_priv->md; 1011 struct file *file = vma->vm_file; 1012 struct mm_struct *mm = vma->vm_mm; 1013 struct mm_walk walk = {}; 1014 struct mempolicy *pol; 1015 int n; 1016 char buffer[50]; 1017 1018 if (!mm) 1019 return 0; 1020 1021 /* Ensure we start with an empty set of numa_maps statistics. */ 1022 memset(md, 0, sizeof(*md)); 1023 1024 md->vma = vma; 1025 1026 walk.hugetlb_entry = gather_hugetbl_stats; 1027 walk.pmd_entry = gather_pte_stats; 1028 walk.private = md; 1029 walk.mm = mm; 1030 1031 pol = get_vma_policy(proc_priv->task, vma, vma->vm_start); 1032 mpol_to_str(buffer, sizeof(buffer), pol, 0); 1033 mpol_cond_put(pol); 1034 1035 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 1036 1037 if (file) { 1038 seq_printf(m, " file="); 1039 seq_path(m, &file->f_path, "\n\t= "); 1040 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { 1041 seq_printf(m, " heap"); 1042 } else if (vma->vm_start <= mm->start_stack && 1043 vma->vm_end >= mm->start_stack) { 1044 seq_printf(m, " stack"); 1045 } 1046 1047 if (is_vm_hugetlb_page(vma)) 1048 seq_printf(m, " huge"); 1049 1050 walk_page_range(vma->vm_start, vma->vm_end, &walk); 1051 1052 if (!md->pages) 1053 goto out; 1054 1055 if (md->anon) 1056 seq_printf(m, " anon=%lu", md->anon); 1057 1058 if (md->dirty) 1059 seq_printf(m, " dirty=%lu", md->dirty); 1060 1061 if (md->pages != md->anon && md->pages != md->dirty) 1062 seq_printf(m, " mapped=%lu", md->pages); 1063 1064 if (md->mapcount_max > 1) 1065 seq_printf(m, " mapmax=%lu", md->mapcount_max); 1066 1067 if (md->swapcache) 1068 seq_printf(m, " swapcache=%lu", md->swapcache); 1069 1070 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 1071 seq_printf(m, " active=%lu", md->active); 1072 1073 if (md->writeback) 1074 seq_printf(m, " writeback=%lu", md->writeback); 1075 1076 for_each_node_state(n, N_HIGH_MEMORY) 1077 if (md->node[n]) 1078 seq_printf(m, " N%d=%lu", n, md->node[n]); 1079 out: 1080 seq_putc(m, '\n'); 1081 1082 if (m->count < m->size) 1083 m->version = (vma != proc_priv->tail_vma) ? vma->vm_start : 0; 1084 return 0; 1085 } 1086 1087 static const struct seq_operations proc_pid_numa_maps_op = { 1088 .start = m_start, 1089 .next = m_next, 1090 .stop = m_stop, 1091 .show = show_numa_map, 1092 }; 1093 1094 static int numa_maps_open(struct inode *inode, struct file *file) 1095 { 1096 struct numa_maps_private *priv; 1097 int ret = -ENOMEM; 1098 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 1099 if (priv) { 1100 priv->proc_maps.pid = proc_pid(inode); 1101 ret = seq_open(file, &proc_pid_numa_maps_op); 1102 if (!ret) { 1103 struct seq_file *m = file->private_data; 1104 m->private = priv; 1105 } else { 1106 kfree(priv); 1107 } 1108 } 1109 return ret; 1110 } 1111 1112 const struct file_operations proc_numa_maps_operations = { 1113 .open = numa_maps_open, 1114 .read = seq_read, 1115 .llseek = seq_lseek, 1116 .release = seq_release_private, 1117 }; 1118 #endif /* CONFIG_NUMA */ 1119