Loading...
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
20void 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
66unsigned long task_vsize(struct mm_struct *mm)
67{
68 return PAGE_SIZE * mm->total_vm;
69}
70
71unsigned 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
83static 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
91static 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
100static 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
156out:
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
167static 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
180static 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
191static 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
210static 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 vm_flags_t 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
276static 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
290static 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
297static int maps_open(struct inode *inode, struct file *file)
298{
299 return do_maps_open(inode, file, &proc_pid_maps_op);
300}
301
302const 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
329struct 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
344static 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
387static 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
423static 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
480static 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
487static int smaps_open(struct inode *inode, struct file *file)
488{
489 return do_maps_open(inode, file, &proc_pid_smaps_op);
490}
491
492const 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
499static 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
532static 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 int type;
540 int rv;
541
542 memset(buffer, 0, sizeof(buffer));
543 if (count > sizeof(buffer) - 1)
544 count = sizeof(buffer) - 1;
545 if (copy_from_user(buffer, buf, count))
546 return -EFAULT;
547 rv = kstrtoint(strstrip(buffer), 10, &type);
548 if (rv < 0)
549 return rv;
550 if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED)
551 return -EINVAL;
552 task = get_proc_task(file->f_path.dentry->d_inode);
553 if (!task)
554 return -ESRCH;
555 mm = get_task_mm(task);
556 if (mm) {
557 struct mm_walk clear_refs_walk = {
558 .pmd_entry = clear_refs_pte_range,
559 .mm = mm,
560 };
561 down_read(&mm->mmap_sem);
562 for (vma = mm->mmap; vma; vma = vma->vm_next) {
563 clear_refs_walk.private = vma;
564 if (is_vm_hugetlb_page(vma))
565 continue;
566 /*
567 * Writing 1 to /proc/pid/clear_refs affects all pages.
568 *
569 * Writing 2 to /proc/pid/clear_refs only affects
570 * Anonymous pages.
571 *
572 * Writing 3 to /proc/pid/clear_refs only affects file
573 * mapped pages.
574 */
575 if (type == CLEAR_REFS_ANON && vma->vm_file)
576 continue;
577 if (type == CLEAR_REFS_MAPPED && !vma->vm_file)
578 continue;
579 walk_page_range(vma->vm_start, vma->vm_end,
580 &clear_refs_walk);
581 }
582 flush_tlb_mm(mm);
583 up_read(&mm->mmap_sem);
584 mmput(mm);
585 }
586 put_task_struct(task);
587
588 return count;
589}
590
591const struct file_operations proc_clear_refs_operations = {
592 .write = clear_refs_write,
593 .llseek = noop_llseek,
594};
595
596struct pagemapread {
597 int pos, len;
598 u64 *buffer;
599};
600
601#define PM_ENTRY_BYTES sizeof(u64)
602#define PM_STATUS_BITS 3
603#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
604#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
605#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
606#define PM_PSHIFT_BITS 6
607#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
608#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
609#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
610#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
611#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
612
613#define PM_PRESENT PM_STATUS(4LL)
614#define PM_SWAP PM_STATUS(2LL)
615#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
616#define PM_END_OF_BUFFER 1
617
618static int add_to_pagemap(unsigned long addr, u64 pfn,
619 struct pagemapread *pm)
620{
621 pm->buffer[pm->pos++] = pfn;
622 if (pm->pos >= pm->len)
623 return PM_END_OF_BUFFER;
624 return 0;
625}
626
627static int pagemap_pte_hole(unsigned long start, unsigned long end,
628 struct mm_walk *walk)
629{
630 struct pagemapread *pm = walk->private;
631 unsigned long addr;
632 int err = 0;
633 for (addr = start; addr < end; addr += PAGE_SIZE) {
634 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
635 if (err)
636 break;
637 }
638 return err;
639}
640
641static u64 swap_pte_to_pagemap_entry(pte_t pte)
642{
643 swp_entry_t e = pte_to_swp_entry(pte);
644 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
645}
646
647static u64 pte_to_pagemap_entry(pte_t pte)
648{
649 u64 pme = 0;
650 if (is_swap_pte(pte))
651 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
652 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
653 else if (pte_present(pte))
654 pme = PM_PFRAME(pte_pfn(pte))
655 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
656 return pme;
657}
658
659static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
660 struct mm_walk *walk)
661{
662 struct vm_area_struct *vma;
663 struct pagemapread *pm = walk->private;
664 pte_t *pte;
665 int err = 0;
666
667 split_huge_page_pmd(walk->mm, pmd);
668
669 /* find the first VMA at or above 'addr' */
670 vma = find_vma(walk->mm, addr);
671 for (; addr != end; addr += PAGE_SIZE) {
672 u64 pfn = PM_NOT_PRESENT;
673
674 /* check to see if we've left 'vma' behind
675 * and need a new, higher one */
676 if (vma && (addr >= vma->vm_end))
677 vma = find_vma(walk->mm, addr);
678
679 /* check that 'vma' actually covers this address,
680 * and that it isn't a huge page vma */
681 if (vma && (vma->vm_start <= addr) &&
682 !is_vm_hugetlb_page(vma)) {
683 pte = pte_offset_map(pmd, addr);
684 pfn = pte_to_pagemap_entry(*pte);
685 /* unmap before userspace copy */
686 pte_unmap(pte);
687 }
688 err = add_to_pagemap(addr, pfn, pm);
689 if (err)
690 return err;
691 }
692
693 cond_resched();
694
695 return err;
696}
697
698#ifdef CONFIG_HUGETLB_PAGE
699static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset)
700{
701 u64 pme = 0;
702 if (pte_present(pte))
703 pme = PM_PFRAME(pte_pfn(pte) + offset)
704 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
705 return pme;
706}
707
708/* This function walks within one hugetlb entry in the single call */
709static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
710 unsigned long addr, unsigned long end,
711 struct mm_walk *walk)
712{
713 struct pagemapread *pm = walk->private;
714 int err = 0;
715 u64 pfn;
716
717 for (; addr != end; addr += PAGE_SIZE) {
718 int offset = (addr & ~hmask) >> PAGE_SHIFT;
719 pfn = huge_pte_to_pagemap_entry(*pte, offset);
720 err = add_to_pagemap(addr, pfn, pm);
721 if (err)
722 return err;
723 }
724
725 cond_resched();
726
727 return err;
728}
729#endif /* HUGETLB_PAGE */
730
731/*
732 * /proc/pid/pagemap - an array mapping virtual pages to pfns
733 *
734 * For each page in the address space, this file contains one 64-bit entry
735 * consisting of the following:
736 *
737 * Bits 0-55 page frame number (PFN) if present
738 * Bits 0-4 swap type if swapped
739 * Bits 5-55 swap offset if swapped
740 * Bits 55-60 page shift (page size = 1<<page shift)
741 * Bit 61 reserved for future use
742 * Bit 62 page swapped
743 * Bit 63 page present
744 *
745 * If the page is not present but in swap, then the PFN contains an
746 * encoding of the swap file number and the page's offset into the
747 * swap. Unmapped pages return a null PFN. This allows determining
748 * precisely which pages are mapped (or in swap) and comparing mapped
749 * pages between processes.
750 *
751 * Efficient users of this interface will use /proc/pid/maps to
752 * determine which areas of memory are actually mapped and llseek to
753 * skip over unmapped regions.
754 */
755#define PAGEMAP_WALK_SIZE (PMD_SIZE)
756#define PAGEMAP_WALK_MASK (PMD_MASK)
757static ssize_t pagemap_read(struct file *file, char __user *buf,
758 size_t count, loff_t *ppos)
759{
760 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
761 struct mm_struct *mm;
762 struct pagemapread pm;
763 int ret = -ESRCH;
764 struct mm_walk pagemap_walk = {};
765 unsigned long src;
766 unsigned long svpfn;
767 unsigned long start_vaddr;
768 unsigned long end_vaddr;
769 int copied = 0;
770
771 if (!task)
772 goto out;
773
774 ret = -EINVAL;
775 /* file position must be aligned */
776 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
777 goto out_task;
778
779 ret = 0;
780 if (!count)
781 goto out_task;
782
783 pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
784 pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
785 ret = -ENOMEM;
786 if (!pm.buffer)
787 goto out_task;
788
789 mm = mm_for_maps(task);
790 ret = PTR_ERR(mm);
791 if (!mm || IS_ERR(mm))
792 goto out_free;
793
794 pagemap_walk.pmd_entry = pagemap_pte_range;
795 pagemap_walk.pte_hole = pagemap_pte_hole;
796#ifdef CONFIG_HUGETLB_PAGE
797 pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
798#endif
799 pagemap_walk.mm = mm;
800 pagemap_walk.private = ±
801
802 src = *ppos;
803 svpfn = src / PM_ENTRY_BYTES;
804 start_vaddr = svpfn << PAGE_SHIFT;
805 end_vaddr = TASK_SIZE_OF(task);
806
807 /* watch out for wraparound */
808 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
809 start_vaddr = end_vaddr;
810
811 /*
812 * The odds are that this will stop walking way
813 * before end_vaddr, because the length of the
814 * user buffer is tracked in "pm", and the walk
815 * will stop when we hit the end of the buffer.
816 */
817 ret = 0;
818 while (count && (start_vaddr < end_vaddr)) {
819 int len;
820 unsigned long end;
821
822 pm.pos = 0;
823 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
824 /* overflow ? */
825 if (end < start_vaddr || end > end_vaddr)
826 end = end_vaddr;
827 down_read(&mm->mmap_sem);
828 ret = walk_page_range(start_vaddr, end, &pagemap_walk);
829 up_read(&mm->mmap_sem);
830 start_vaddr = end;
831
832 len = min(count, PM_ENTRY_BYTES * pm.pos);
833 if (copy_to_user(buf, pm.buffer, len)) {
834 ret = -EFAULT;
835 goto out_mm;
836 }
837 copied += len;
838 buf += len;
839 count -= len;
840 }
841 *ppos += copied;
842 if (!ret || ret == PM_END_OF_BUFFER)
843 ret = copied;
844
845out_mm:
846 mmput(mm);
847out_free:
848 kfree(pm.buffer);
849out_task:
850 put_task_struct(task);
851out:
852 return ret;
853}
854
855const struct file_operations proc_pagemap_operations = {
856 .llseek = mem_lseek, /* borrow this */
857 .read = pagemap_read,
858};
859#endif /* CONFIG_PROC_PAGE_MONITOR */
860
861#ifdef CONFIG_NUMA
862
863struct numa_maps {
864 struct vm_area_struct *vma;
865 unsigned long pages;
866 unsigned long anon;
867 unsigned long active;
868 unsigned long writeback;
869 unsigned long mapcount_max;
870 unsigned long dirty;
871 unsigned long swapcache;
872 unsigned long node[MAX_NUMNODES];
873};
874
875struct numa_maps_private {
876 struct proc_maps_private proc_maps;
877 struct numa_maps md;
878};
879
880static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
881 unsigned long nr_pages)
882{
883 int count = page_mapcount(page);
884
885 md->pages += nr_pages;
886 if (pte_dirty || PageDirty(page))
887 md->dirty += nr_pages;
888
889 if (PageSwapCache(page))
890 md->swapcache += nr_pages;
891
892 if (PageActive(page) || PageUnevictable(page))
893 md->active += nr_pages;
894
895 if (PageWriteback(page))
896 md->writeback += nr_pages;
897
898 if (PageAnon(page))
899 md->anon += nr_pages;
900
901 if (count > md->mapcount_max)
902 md->mapcount_max = count;
903
904 md->node[page_to_nid(page)] += nr_pages;
905}
906
907static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
908 unsigned long addr)
909{
910 struct page *page;
911 int nid;
912
913 if (!pte_present(pte))
914 return NULL;
915
916 page = vm_normal_page(vma, addr, pte);
917 if (!page)
918 return NULL;
919
920 if (PageReserved(page))
921 return NULL;
922
923 nid = page_to_nid(page);
924 if (!node_isset(nid, node_states[N_HIGH_MEMORY]))
925 return NULL;
926
927 return page;
928}
929
930static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
931 unsigned long end, struct mm_walk *walk)
932{
933 struct numa_maps *md;
934 spinlock_t *ptl;
935 pte_t *orig_pte;
936 pte_t *pte;
937
938 md = walk->private;
939 spin_lock(&walk->mm->page_table_lock);
940 if (pmd_trans_huge(*pmd)) {
941 if (pmd_trans_splitting(*pmd)) {
942 spin_unlock(&walk->mm->page_table_lock);
943 wait_split_huge_page(md->vma->anon_vma, pmd);
944 } else {
945 pte_t huge_pte = *(pte_t *)pmd;
946 struct page *page;
947
948 page = can_gather_numa_stats(huge_pte, md->vma, addr);
949 if (page)
950 gather_stats(page, md, pte_dirty(huge_pte),
951 HPAGE_PMD_SIZE/PAGE_SIZE);
952 spin_unlock(&walk->mm->page_table_lock);
953 return 0;
954 }
955 } else {
956 spin_unlock(&walk->mm->page_table_lock);
957 }
958
959 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
960 do {
961 struct page *page = can_gather_numa_stats(*pte, md->vma, addr);
962 if (!page)
963 continue;
964 gather_stats(page, md, pte_dirty(*pte), 1);
965
966 } while (pte++, addr += PAGE_SIZE, addr != end);
967 pte_unmap_unlock(orig_pte, ptl);
968 return 0;
969}
970#ifdef CONFIG_HUGETLB_PAGE
971static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
972 unsigned long addr, unsigned long end, struct mm_walk *walk)
973{
974 struct numa_maps *md;
975 struct page *page;
976
977 if (pte_none(*pte))
978 return 0;
979
980 page = pte_page(*pte);
981 if (!page)
982 return 0;
983
984 md = walk->private;
985 gather_stats(page, md, pte_dirty(*pte), 1);
986 return 0;
987}
988
989#else
990static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
991 unsigned long addr, unsigned long end, struct mm_walk *walk)
992{
993 return 0;
994}
995#endif
996
997/*
998 * Display pages allocated per node and memory policy via /proc.
999 */
1000static int show_numa_map(struct seq_file *m, void *v)
1001{
1002 struct numa_maps_private *numa_priv = m->private;
1003 struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1004 struct vm_area_struct *vma = v;
1005 struct numa_maps *md = &numa_priv->md;
1006 struct file *file = vma->vm_file;
1007 struct mm_struct *mm = vma->vm_mm;
1008 struct mm_walk walk = {};
1009 struct mempolicy *pol;
1010 int n;
1011 char buffer[50];
1012
1013 if (!mm)
1014 return 0;
1015
1016 /* Ensure we start with an empty set of numa_maps statistics. */
1017 memset(md, 0, sizeof(*md));
1018
1019 md->vma = vma;
1020
1021 walk.hugetlb_entry = gather_hugetbl_stats;
1022 walk.pmd_entry = gather_pte_stats;
1023 walk.private = md;
1024 walk.mm = mm;
1025
1026 pol = get_vma_policy(proc_priv->task, vma, vma->vm_start);
1027 mpol_to_str(buffer, sizeof(buffer), pol, 0);
1028 mpol_cond_put(pol);
1029
1030 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1031
1032 if (file) {
1033 seq_printf(m, " file=");
1034 seq_path(m, &file->f_path, "\n\t= ");
1035 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1036 seq_printf(m, " heap");
1037 } else if (vma->vm_start <= mm->start_stack &&
1038 vma->vm_end >= mm->start_stack) {
1039 seq_printf(m, " stack");
1040 }
1041
1042 walk_page_range(vma->vm_start, vma->vm_end, &walk);
1043
1044 if (!md->pages)
1045 goto out;
1046
1047 if (md->anon)
1048 seq_printf(m, " anon=%lu", md->anon);
1049
1050 if (md->dirty)
1051 seq_printf(m, " dirty=%lu", md->dirty);
1052
1053 if (md->pages != md->anon && md->pages != md->dirty)
1054 seq_printf(m, " mapped=%lu", md->pages);
1055
1056 if (md->mapcount_max > 1)
1057 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1058
1059 if (md->swapcache)
1060 seq_printf(m, " swapcache=%lu", md->swapcache);
1061
1062 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1063 seq_printf(m, " active=%lu", md->active);
1064
1065 if (md->writeback)
1066 seq_printf(m, " writeback=%lu", md->writeback);
1067
1068 for_each_node_state(n, N_HIGH_MEMORY)
1069 if (md->node[n])
1070 seq_printf(m, " N%d=%lu", n, md->node[n]);
1071out:
1072 seq_putc(m, '\n');
1073
1074 if (m->count < m->size)
1075 m->version = (vma != proc_priv->tail_vma) ? vma->vm_start : 0;
1076 return 0;
1077}
1078
1079static const struct seq_operations proc_pid_numa_maps_op = {
1080 .start = m_start,
1081 .next = m_next,
1082 .stop = m_stop,
1083 .show = show_numa_map,
1084};
1085
1086static int numa_maps_open(struct inode *inode, struct file *file)
1087{
1088 struct numa_maps_private *priv;
1089 int ret = -ENOMEM;
1090 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1091 if (priv) {
1092 priv->proc_maps.pid = proc_pid(inode);
1093 ret = seq_open(file, &proc_pid_numa_maps_op);
1094 if (!ret) {
1095 struct seq_file *m = file->private_data;
1096 m->private = priv;
1097 } else {
1098 kfree(priv);
1099 }
1100 }
1101 return ret;
1102}
1103
1104const struct file_operations proc_numa_maps_operations = {
1105 .open = numa_maps_open,
1106 .read = seq_read,
1107 .llseek = seq_lseek,
1108 .release = seq_release_private,
1109};
1110#endif /* CONFIG_NUMA */
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/pagewalk.h>
3#include <linux/mm_inline.h>
4#include <linux/hugetlb.h>
5#include <linux/huge_mm.h>
6#include <linux/mount.h>
7#include <linux/ksm.h>
8#include <linux/seq_file.h>
9#include <linux/highmem.h>
10#include <linux/ptrace.h>
11#include <linux/slab.h>
12#include <linux/pagemap.h>
13#include <linux/mempolicy.h>
14#include <linux/rmap.h>
15#include <linux/swap.h>
16#include <linux/sched/mm.h>
17#include <linux/swapops.h>
18#include <linux/mmu_notifier.h>
19#include <linux/page_idle.h>
20#include <linux/shmem_fs.h>
21#include <linux/uaccess.h>
22#include <linux/pkeys.h>
23#include <linux/minmax.h>
24#include <linux/overflow.h>
25
26#include <asm/elf.h>
27#include <asm/tlb.h>
28#include <asm/tlbflush.h>
29#include "internal.h"
30
31#define SEQ_PUT_DEC(str, val) \
32 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
33void task_mem(struct seq_file *m, struct mm_struct *mm)
34{
35 unsigned long text, lib, swap, anon, file, shmem;
36 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
37
38 anon = get_mm_counter(mm, MM_ANONPAGES);
39 file = get_mm_counter(mm, MM_FILEPAGES);
40 shmem = get_mm_counter(mm, MM_SHMEMPAGES);
41
42 /*
43 * Note: to minimize their overhead, mm maintains hiwater_vm and
44 * hiwater_rss only when about to *lower* total_vm or rss. Any
45 * collector of these hiwater stats must therefore get total_vm
46 * and rss too, which will usually be the higher. Barriers? not
47 * worth the effort, such snapshots can always be inconsistent.
48 */
49 hiwater_vm = total_vm = mm->total_vm;
50 if (hiwater_vm < mm->hiwater_vm)
51 hiwater_vm = mm->hiwater_vm;
52 hiwater_rss = total_rss = anon + file + shmem;
53 if (hiwater_rss < mm->hiwater_rss)
54 hiwater_rss = mm->hiwater_rss;
55
56 /* split executable areas between text and lib */
57 text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
58 text = min(text, mm->exec_vm << PAGE_SHIFT);
59 lib = (mm->exec_vm << PAGE_SHIFT) - text;
60
61 swap = get_mm_counter(mm, MM_SWAPENTS);
62 SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
63 SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
64 SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
65 SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
66 SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
67 SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
68 SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
69 SEQ_PUT_DEC(" kB\nRssFile:\t", file);
70 SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
71 SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
72 SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
73 seq_put_decimal_ull_width(m,
74 " kB\nVmExe:\t", text >> 10, 8);
75 seq_put_decimal_ull_width(m,
76 " kB\nVmLib:\t", lib >> 10, 8);
77 seq_put_decimal_ull_width(m,
78 " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
79 SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
80 seq_puts(m, " kB\n");
81 hugetlb_report_usage(m, mm);
82}
83#undef SEQ_PUT_DEC
84
85unsigned long task_vsize(struct mm_struct *mm)
86{
87 return PAGE_SIZE * mm->total_vm;
88}
89
90unsigned long task_statm(struct mm_struct *mm,
91 unsigned long *shared, unsigned long *text,
92 unsigned long *data, unsigned long *resident)
93{
94 *shared = get_mm_counter(mm, MM_FILEPAGES) +
95 get_mm_counter(mm, MM_SHMEMPAGES);
96 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
97 >> PAGE_SHIFT;
98 *data = mm->data_vm + mm->stack_vm;
99 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
100 return mm->total_vm;
101}
102
103#ifdef CONFIG_NUMA
104/*
105 * Save get_task_policy() for show_numa_map().
106 */
107static void hold_task_mempolicy(struct proc_maps_private *priv)
108{
109 struct task_struct *task = priv->task;
110
111 task_lock(task);
112 priv->task_mempolicy = get_task_policy(task);
113 mpol_get(priv->task_mempolicy);
114 task_unlock(task);
115}
116static void release_task_mempolicy(struct proc_maps_private *priv)
117{
118 mpol_put(priv->task_mempolicy);
119}
120#else
121static void hold_task_mempolicy(struct proc_maps_private *priv)
122{
123}
124static void release_task_mempolicy(struct proc_maps_private *priv)
125{
126}
127#endif
128
129static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
130 loff_t *ppos)
131{
132 struct vm_area_struct *vma = vma_next(&priv->iter);
133
134 if (vma) {
135 *ppos = vma->vm_start;
136 } else {
137 *ppos = -2UL;
138 vma = get_gate_vma(priv->mm);
139 }
140
141 return vma;
142}
143
144static void *m_start(struct seq_file *m, loff_t *ppos)
145{
146 struct proc_maps_private *priv = m->private;
147 unsigned long last_addr = *ppos;
148 struct mm_struct *mm;
149
150 /* See m_next(). Zero at the start or after lseek. */
151 if (last_addr == -1UL)
152 return NULL;
153
154 priv->task = get_proc_task(priv->inode);
155 if (!priv->task)
156 return ERR_PTR(-ESRCH);
157
158 mm = priv->mm;
159 if (!mm || !mmget_not_zero(mm)) {
160 put_task_struct(priv->task);
161 priv->task = NULL;
162 return NULL;
163 }
164
165 if (mmap_read_lock_killable(mm)) {
166 mmput(mm);
167 put_task_struct(priv->task);
168 priv->task = NULL;
169 return ERR_PTR(-EINTR);
170 }
171
172 vma_iter_init(&priv->iter, mm, last_addr);
173 hold_task_mempolicy(priv);
174 if (last_addr == -2UL)
175 return get_gate_vma(mm);
176
177 return proc_get_vma(priv, ppos);
178}
179
180static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
181{
182 if (*ppos == -2UL) {
183 *ppos = -1UL;
184 return NULL;
185 }
186 return proc_get_vma(m->private, ppos);
187}
188
189static void m_stop(struct seq_file *m, void *v)
190{
191 struct proc_maps_private *priv = m->private;
192 struct mm_struct *mm = priv->mm;
193
194 if (!priv->task)
195 return;
196
197 release_task_mempolicy(priv);
198 mmap_read_unlock(mm);
199 mmput(mm);
200 put_task_struct(priv->task);
201 priv->task = NULL;
202}
203
204static int proc_maps_open(struct inode *inode, struct file *file,
205 const struct seq_operations *ops, int psize)
206{
207 struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
208
209 if (!priv)
210 return -ENOMEM;
211
212 priv->inode = inode;
213 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
214 if (IS_ERR(priv->mm)) {
215 int err = PTR_ERR(priv->mm);
216
217 seq_release_private(inode, file);
218 return err;
219 }
220
221 return 0;
222}
223
224static int proc_map_release(struct inode *inode, struct file *file)
225{
226 struct seq_file *seq = file->private_data;
227 struct proc_maps_private *priv = seq->private;
228
229 if (priv->mm)
230 mmdrop(priv->mm);
231
232 return seq_release_private(inode, file);
233}
234
235static int do_maps_open(struct inode *inode, struct file *file,
236 const struct seq_operations *ops)
237{
238 return proc_maps_open(inode, file, ops,
239 sizeof(struct proc_maps_private));
240}
241
242static void show_vma_header_prefix(struct seq_file *m,
243 unsigned long start, unsigned long end,
244 vm_flags_t flags, unsigned long long pgoff,
245 dev_t dev, unsigned long ino)
246{
247 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
248 seq_put_hex_ll(m, NULL, start, 8);
249 seq_put_hex_ll(m, "-", end, 8);
250 seq_putc(m, ' ');
251 seq_putc(m, flags & VM_READ ? 'r' : '-');
252 seq_putc(m, flags & VM_WRITE ? 'w' : '-');
253 seq_putc(m, flags & VM_EXEC ? 'x' : '-');
254 seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
255 seq_put_hex_ll(m, " ", pgoff, 8);
256 seq_put_hex_ll(m, " ", MAJOR(dev), 2);
257 seq_put_hex_ll(m, ":", MINOR(dev), 2);
258 seq_put_decimal_ull(m, " ", ino);
259 seq_putc(m, ' ');
260}
261
262static void
263show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
264{
265 struct anon_vma_name *anon_name = NULL;
266 struct mm_struct *mm = vma->vm_mm;
267 struct file *file = vma->vm_file;
268 vm_flags_t flags = vma->vm_flags;
269 unsigned long ino = 0;
270 unsigned long long pgoff = 0;
271 unsigned long start, end;
272 dev_t dev = 0;
273 const char *name = NULL;
274
275 if (file) {
276 const struct inode *inode = file_user_inode(vma->vm_file);
277
278 dev = inode->i_sb->s_dev;
279 ino = inode->i_ino;
280 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
281 }
282
283 start = vma->vm_start;
284 end = vma->vm_end;
285 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
286 if (mm)
287 anon_name = anon_vma_name(vma);
288
289 /*
290 * Print the dentry name for named mappings, and a
291 * special [heap] marker for the heap:
292 */
293 if (file) {
294 seq_pad(m, ' ');
295 /*
296 * If user named this anon shared memory via
297 * prctl(PR_SET_VMA ..., use the provided name.
298 */
299 if (anon_name)
300 seq_printf(m, "[anon_shmem:%s]", anon_name->name);
301 else
302 seq_path(m, file_user_path(file), "\n");
303 goto done;
304 }
305
306 if (vma->vm_ops && vma->vm_ops->name) {
307 name = vma->vm_ops->name(vma);
308 if (name)
309 goto done;
310 }
311
312 name = arch_vma_name(vma);
313 if (!name) {
314 if (!mm) {
315 name = "[vdso]";
316 goto done;
317 }
318
319 if (vma_is_initial_heap(vma)) {
320 name = "[heap]";
321 goto done;
322 }
323
324 if (vma_is_initial_stack(vma)) {
325 name = "[stack]";
326 goto done;
327 }
328
329 if (anon_name) {
330 seq_pad(m, ' ');
331 seq_printf(m, "[anon:%s]", anon_name->name);
332 }
333 }
334
335done:
336 if (name) {
337 seq_pad(m, ' ');
338 seq_puts(m, name);
339 }
340 seq_putc(m, '\n');
341}
342
343static int show_map(struct seq_file *m, void *v)
344{
345 show_map_vma(m, v);
346 return 0;
347}
348
349static const struct seq_operations proc_pid_maps_op = {
350 .start = m_start,
351 .next = m_next,
352 .stop = m_stop,
353 .show = show_map
354};
355
356static int pid_maps_open(struct inode *inode, struct file *file)
357{
358 return do_maps_open(inode, file, &proc_pid_maps_op);
359}
360
361const struct file_operations proc_pid_maps_operations = {
362 .open = pid_maps_open,
363 .read = seq_read,
364 .llseek = seq_lseek,
365 .release = proc_map_release,
366};
367
368/*
369 * Proportional Set Size(PSS): my share of RSS.
370 *
371 * PSS of a process is the count of pages it has in memory, where each
372 * page is divided by the number of processes sharing it. So if a
373 * process has 1000 pages all to itself, and 1000 shared with one other
374 * process, its PSS will be 1500.
375 *
376 * To keep (accumulated) division errors low, we adopt a 64bit
377 * fixed-point pss counter to minimize division errors. So (pss >>
378 * PSS_SHIFT) would be the real byte count.
379 *
380 * A shift of 12 before division means (assuming 4K page size):
381 * - 1M 3-user-pages add up to 8KB errors;
382 * - supports mapcount up to 2^24, or 16M;
383 * - supports PSS up to 2^52 bytes, or 4PB.
384 */
385#define PSS_SHIFT 12
386
387#ifdef CONFIG_PROC_PAGE_MONITOR
388struct mem_size_stats {
389 unsigned long resident;
390 unsigned long shared_clean;
391 unsigned long shared_dirty;
392 unsigned long private_clean;
393 unsigned long private_dirty;
394 unsigned long referenced;
395 unsigned long anonymous;
396 unsigned long lazyfree;
397 unsigned long anonymous_thp;
398 unsigned long shmem_thp;
399 unsigned long file_thp;
400 unsigned long swap;
401 unsigned long shared_hugetlb;
402 unsigned long private_hugetlb;
403 unsigned long ksm;
404 u64 pss;
405 u64 pss_anon;
406 u64 pss_file;
407 u64 pss_shmem;
408 u64 pss_dirty;
409 u64 pss_locked;
410 u64 swap_pss;
411};
412
413static void smaps_page_accumulate(struct mem_size_stats *mss,
414 struct page *page, unsigned long size, unsigned long pss,
415 bool dirty, bool locked, bool private)
416{
417 mss->pss += pss;
418
419 if (PageAnon(page))
420 mss->pss_anon += pss;
421 else if (PageSwapBacked(page))
422 mss->pss_shmem += pss;
423 else
424 mss->pss_file += pss;
425
426 if (locked)
427 mss->pss_locked += pss;
428
429 if (dirty || PageDirty(page)) {
430 mss->pss_dirty += pss;
431 if (private)
432 mss->private_dirty += size;
433 else
434 mss->shared_dirty += size;
435 } else {
436 if (private)
437 mss->private_clean += size;
438 else
439 mss->shared_clean += size;
440 }
441}
442
443static void smaps_account(struct mem_size_stats *mss, struct page *page,
444 bool compound, bool young, bool dirty, bool locked,
445 bool migration)
446{
447 int i, nr = compound ? compound_nr(page) : 1;
448 unsigned long size = nr * PAGE_SIZE;
449
450 /*
451 * First accumulate quantities that depend only on |size| and the type
452 * of the compound page.
453 */
454 if (PageAnon(page)) {
455 mss->anonymous += size;
456 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
457 mss->lazyfree += size;
458 }
459
460 if (PageKsm(page))
461 mss->ksm += size;
462
463 mss->resident += size;
464 /* Accumulate the size in pages that have been accessed. */
465 if (young || page_is_young(page) || PageReferenced(page))
466 mss->referenced += size;
467
468 /*
469 * Then accumulate quantities that may depend on sharing, or that may
470 * differ page-by-page.
471 *
472 * page_count(page) == 1 guarantees the page is mapped exactly once.
473 * If any subpage of the compound page mapped with PTE it would elevate
474 * page_count().
475 *
476 * The page_mapcount() is called to get a snapshot of the mapcount.
477 * Without holding the page lock this snapshot can be slightly wrong as
478 * we cannot always read the mapcount atomically. It is not safe to
479 * call page_mapcount() even with PTL held if the page is not mapped,
480 * especially for migration entries. Treat regular migration entries
481 * as mapcount == 1.
482 */
483 if ((page_count(page) == 1) || migration) {
484 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
485 locked, true);
486 return;
487 }
488 for (i = 0; i < nr; i++, page++) {
489 int mapcount = page_mapcount(page);
490 unsigned long pss = PAGE_SIZE << PSS_SHIFT;
491 if (mapcount >= 2)
492 pss /= mapcount;
493 smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
494 mapcount < 2);
495 }
496}
497
498#ifdef CONFIG_SHMEM
499static int smaps_pte_hole(unsigned long addr, unsigned long end,
500 __always_unused int depth, struct mm_walk *walk)
501{
502 struct mem_size_stats *mss = walk->private;
503 struct vm_area_struct *vma = walk->vma;
504
505 mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
506 linear_page_index(vma, addr),
507 linear_page_index(vma, end));
508
509 return 0;
510}
511#else
512#define smaps_pte_hole NULL
513#endif /* CONFIG_SHMEM */
514
515static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
516{
517#ifdef CONFIG_SHMEM
518 if (walk->ops->pte_hole) {
519 /* depth is not used */
520 smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
521 }
522#endif
523}
524
525static void smaps_pte_entry(pte_t *pte, unsigned long addr,
526 struct mm_walk *walk)
527{
528 struct mem_size_stats *mss = walk->private;
529 struct vm_area_struct *vma = walk->vma;
530 bool locked = !!(vma->vm_flags & VM_LOCKED);
531 struct page *page = NULL;
532 bool migration = false, young = false, dirty = false;
533 pte_t ptent = ptep_get(pte);
534
535 if (pte_present(ptent)) {
536 page = vm_normal_page(vma, addr, ptent);
537 young = pte_young(ptent);
538 dirty = pte_dirty(ptent);
539 } else if (is_swap_pte(ptent)) {
540 swp_entry_t swpent = pte_to_swp_entry(ptent);
541
542 if (!non_swap_entry(swpent)) {
543 int mapcount;
544
545 mss->swap += PAGE_SIZE;
546 mapcount = swp_swapcount(swpent);
547 if (mapcount >= 2) {
548 u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
549
550 do_div(pss_delta, mapcount);
551 mss->swap_pss += pss_delta;
552 } else {
553 mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
554 }
555 } else if (is_pfn_swap_entry(swpent)) {
556 if (is_migration_entry(swpent))
557 migration = true;
558 page = pfn_swap_entry_to_page(swpent);
559 }
560 } else {
561 smaps_pte_hole_lookup(addr, walk);
562 return;
563 }
564
565 if (!page)
566 return;
567
568 smaps_account(mss, page, false, young, dirty, locked, migration);
569}
570
571#ifdef CONFIG_TRANSPARENT_HUGEPAGE
572static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
573 struct mm_walk *walk)
574{
575 struct mem_size_stats *mss = walk->private;
576 struct vm_area_struct *vma = walk->vma;
577 bool locked = !!(vma->vm_flags & VM_LOCKED);
578 struct page *page = NULL;
579 bool migration = false;
580
581 if (pmd_present(*pmd)) {
582 page = vm_normal_page_pmd(vma, addr, *pmd);
583 } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
584 swp_entry_t entry = pmd_to_swp_entry(*pmd);
585
586 if (is_migration_entry(entry)) {
587 migration = true;
588 page = pfn_swap_entry_to_page(entry);
589 }
590 }
591 if (IS_ERR_OR_NULL(page))
592 return;
593 if (PageAnon(page))
594 mss->anonymous_thp += HPAGE_PMD_SIZE;
595 else if (PageSwapBacked(page))
596 mss->shmem_thp += HPAGE_PMD_SIZE;
597 else if (is_zone_device_page(page))
598 /* pass */;
599 else
600 mss->file_thp += HPAGE_PMD_SIZE;
601
602 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
603 locked, migration);
604}
605#else
606static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
607 struct mm_walk *walk)
608{
609}
610#endif
611
612static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
613 struct mm_walk *walk)
614{
615 struct vm_area_struct *vma = walk->vma;
616 pte_t *pte;
617 spinlock_t *ptl;
618
619 ptl = pmd_trans_huge_lock(pmd, vma);
620 if (ptl) {
621 smaps_pmd_entry(pmd, addr, walk);
622 spin_unlock(ptl);
623 goto out;
624 }
625
626 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
627 if (!pte) {
628 walk->action = ACTION_AGAIN;
629 return 0;
630 }
631 for (; addr != end; pte++, addr += PAGE_SIZE)
632 smaps_pte_entry(pte, addr, walk);
633 pte_unmap_unlock(pte - 1, ptl);
634out:
635 cond_resched();
636 return 0;
637}
638
639static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
640{
641 /*
642 * Don't forget to update Documentation/ on changes.
643 */
644 static const char mnemonics[BITS_PER_LONG][2] = {
645 /*
646 * In case if we meet a flag we don't know about.
647 */
648 [0 ... (BITS_PER_LONG-1)] = "??",
649
650 [ilog2(VM_READ)] = "rd",
651 [ilog2(VM_WRITE)] = "wr",
652 [ilog2(VM_EXEC)] = "ex",
653 [ilog2(VM_SHARED)] = "sh",
654 [ilog2(VM_MAYREAD)] = "mr",
655 [ilog2(VM_MAYWRITE)] = "mw",
656 [ilog2(VM_MAYEXEC)] = "me",
657 [ilog2(VM_MAYSHARE)] = "ms",
658 [ilog2(VM_GROWSDOWN)] = "gd",
659 [ilog2(VM_PFNMAP)] = "pf",
660 [ilog2(VM_LOCKED)] = "lo",
661 [ilog2(VM_IO)] = "io",
662 [ilog2(VM_SEQ_READ)] = "sr",
663 [ilog2(VM_RAND_READ)] = "rr",
664 [ilog2(VM_DONTCOPY)] = "dc",
665 [ilog2(VM_DONTEXPAND)] = "de",
666 [ilog2(VM_LOCKONFAULT)] = "lf",
667 [ilog2(VM_ACCOUNT)] = "ac",
668 [ilog2(VM_NORESERVE)] = "nr",
669 [ilog2(VM_HUGETLB)] = "ht",
670 [ilog2(VM_SYNC)] = "sf",
671 [ilog2(VM_ARCH_1)] = "ar",
672 [ilog2(VM_WIPEONFORK)] = "wf",
673 [ilog2(VM_DONTDUMP)] = "dd",
674#ifdef CONFIG_ARM64_BTI
675 [ilog2(VM_ARM64_BTI)] = "bt",
676#endif
677#ifdef CONFIG_MEM_SOFT_DIRTY
678 [ilog2(VM_SOFTDIRTY)] = "sd",
679#endif
680 [ilog2(VM_MIXEDMAP)] = "mm",
681 [ilog2(VM_HUGEPAGE)] = "hg",
682 [ilog2(VM_NOHUGEPAGE)] = "nh",
683 [ilog2(VM_MERGEABLE)] = "mg",
684 [ilog2(VM_UFFD_MISSING)]= "um",
685 [ilog2(VM_UFFD_WP)] = "uw",
686#ifdef CONFIG_ARM64_MTE
687 [ilog2(VM_MTE)] = "mt",
688 [ilog2(VM_MTE_ALLOWED)] = "",
689#endif
690#ifdef CONFIG_ARCH_HAS_PKEYS
691 /* These come out via ProtectionKey: */
692 [ilog2(VM_PKEY_BIT0)] = "",
693 [ilog2(VM_PKEY_BIT1)] = "",
694 [ilog2(VM_PKEY_BIT2)] = "",
695 [ilog2(VM_PKEY_BIT3)] = "",
696#if VM_PKEY_BIT4
697 [ilog2(VM_PKEY_BIT4)] = "",
698#endif
699#endif /* CONFIG_ARCH_HAS_PKEYS */
700#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
701 [ilog2(VM_UFFD_MINOR)] = "ui",
702#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
703#ifdef CONFIG_X86_USER_SHADOW_STACK
704 [ilog2(VM_SHADOW_STACK)] = "ss",
705#endif
706 };
707 size_t i;
708
709 seq_puts(m, "VmFlags: ");
710 for (i = 0; i < BITS_PER_LONG; i++) {
711 if (!mnemonics[i][0])
712 continue;
713 if (vma->vm_flags & (1UL << i)) {
714 seq_putc(m, mnemonics[i][0]);
715 seq_putc(m, mnemonics[i][1]);
716 seq_putc(m, ' ');
717 }
718 }
719 seq_putc(m, '\n');
720}
721
722#ifdef CONFIG_HUGETLB_PAGE
723static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
724 unsigned long addr, unsigned long end,
725 struct mm_walk *walk)
726{
727 struct mem_size_stats *mss = walk->private;
728 struct vm_area_struct *vma = walk->vma;
729 struct page *page = NULL;
730 pte_t ptent = ptep_get(pte);
731
732 if (pte_present(ptent)) {
733 page = vm_normal_page(vma, addr, ptent);
734 } else if (is_swap_pte(ptent)) {
735 swp_entry_t swpent = pte_to_swp_entry(ptent);
736
737 if (is_pfn_swap_entry(swpent))
738 page = pfn_swap_entry_to_page(swpent);
739 }
740 if (page) {
741 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
742 mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
743 else
744 mss->private_hugetlb += huge_page_size(hstate_vma(vma));
745 }
746 return 0;
747}
748#else
749#define smaps_hugetlb_range NULL
750#endif /* HUGETLB_PAGE */
751
752static const struct mm_walk_ops smaps_walk_ops = {
753 .pmd_entry = smaps_pte_range,
754 .hugetlb_entry = smaps_hugetlb_range,
755 .walk_lock = PGWALK_RDLOCK,
756};
757
758static const struct mm_walk_ops smaps_shmem_walk_ops = {
759 .pmd_entry = smaps_pte_range,
760 .hugetlb_entry = smaps_hugetlb_range,
761 .pte_hole = smaps_pte_hole,
762 .walk_lock = PGWALK_RDLOCK,
763};
764
765/*
766 * Gather mem stats from @vma with the indicated beginning
767 * address @start, and keep them in @mss.
768 *
769 * Use vm_start of @vma as the beginning address if @start is 0.
770 */
771static void smap_gather_stats(struct vm_area_struct *vma,
772 struct mem_size_stats *mss, unsigned long start)
773{
774 const struct mm_walk_ops *ops = &smaps_walk_ops;
775
776 /* Invalid start */
777 if (start >= vma->vm_end)
778 return;
779
780 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
781 /*
782 * For shared or readonly shmem mappings we know that all
783 * swapped out pages belong to the shmem object, and we can
784 * obtain the swap value much more efficiently. For private
785 * writable mappings, we might have COW pages that are
786 * not affected by the parent swapped out pages of the shmem
787 * object, so we have to distinguish them during the page walk.
788 * Unless we know that the shmem object (or the part mapped by
789 * our VMA) has no swapped out pages at all.
790 */
791 unsigned long shmem_swapped = shmem_swap_usage(vma);
792
793 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
794 !(vma->vm_flags & VM_WRITE))) {
795 mss->swap += shmem_swapped;
796 } else {
797 ops = &smaps_shmem_walk_ops;
798 }
799 }
800
801 /* mmap_lock is held in m_start */
802 if (!start)
803 walk_page_vma(vma, ops, mss);
804 else
805 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
806}
807
808#define SEQ_PUT_DEC(str, val) \
809 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
810
811/* Show the contents common for smaps and smaps_rollup */
812static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
813 bool rollup_mode)
814{
815 SEQ_PUT_DEC("Rss: ", mss->resident);
816 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
817 SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT);
818 if (rollup_mode) {
819 /*
820 * These are meaningful only for smaps_rollup, otherwise two of
821 * them are zero, and the other one is the same as Pss.
822 */
823 SEQ_PUT_DEC(" kB\nPss_Anon: ",
824 mss->pss_anon >> PSS_SHIFT);
825 SEQ_PUT_DEC(" kB\nPss_File: ",
826 mss->pss_file >> PSS_SHIFT);
827 SEQ_PUT_DEC(" kB\nPss_Shmem: ",
828 mss->pss_shmem >> PSS_SHIFT);
829 }
830 SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean);
831 SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty);
832 SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean);
833 SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty);
834 SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced);
835 SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous);
836 SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm);
837 SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree);
838 SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp);
839 SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
840 SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp);
841 SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
842 seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
843 mss->private_hugetlb >> 10, 7);
844 SEQ_PUT_DEC(" kB\nSwap: ", mss->swap);
845 SEQ_PUT_DEC(" kB\nSwapPss: ",
846 mss->swap_pss >> PSS_SHIFT);
847 SEQ_PUT_DEC(" kB\nLocked: ",
848 mss->pss_locked >> PSS_SHIFT);
849 seq_puts(m, " kB\n");
850}
851
852static int show_smap(struct seq_file *m, void *v)
853{
854 struct vm_area_struct *vma = v;
855 struct mem_size_stats mss = {};
856
857 smap_gather_stats(vma, &mss, 0);
858
859 show_map_vma(m, vma);
860
861 SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start);
862 SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
863 SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma));
864 seq_puts(m, " kB\n");
865
866 __show_smap(m, &mss, false);
867
868 seq_printf(m, "THPeligible: %8u\n",
869 !!thp_vma_allowable_orders(vma, vma->vm_flags, true, false,
870 true, THP_ORDERS_ALL));
871
872 if (arch_pkeys_enabled())
873 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
874 show_smap_vma_flags(m, vma);
875
876 return 0;
877}
878
879static int show_smaps_rollup(struct seq_file *m, void *v)
880{
881 struct proc_maps_private *priv = m->private;
882 struct mem_size_stats mss = {};
883 struct mm_struct *mm = priv->mm;
884 struct vm_area_struct *vma;
885 unsigned long vma_start = 0, last_vma_end = 0;
886 int ret = 0;
887 VMA_ITERATOR(vmi, mm, 0);
888
889 priv->task = get_proc_task(priv->inode);
890 if (!priv->task)
891 return -ESRCH;
892
893 if (!mm || !mmget_not_zero(mm)) {
894 ret = -ESRCH;
895 goto out_put_task;
896 }
897
898 ret = mmap_read_lock_killable(mm);
899 if (ret)
900 goto out_put_mm;
901
902 hold_task_mempolicy(priv);
903 vma = vma_next(&vmi);
904
905 if (unlikely(!vma))
906 goto empty_set;
907
908 vma_start = vma->vm_start;
909 do {
910 smap_gather_stats(vma, &mss, 0);
911 last_vma_end = vma->vm_end;
912
913 /*
914 * Release mmap_lock temporarily if someone wants to
915 * access it for write request.
916 */
917 if (mmap_lock_is_contended(mm)) {
918 vma_iter_invalidate(&vmi);
919 mmap_read_unlock(mm);
920 ret = mmap_read_lock_killable(mm);
921 if (ret) {
922 release_task_mempolicy(priv);
923 goto out_put_mm;
924 }
925
926 /*
927 * After dropping the lock, there are four cases to
928 * consider. See the following example for explanation.
929 *
930 * +------+------+-----------+
931 * | VMA1 | VMA2 | VMA3 |
932 * +------+------+-----------+
933 * | | | |
934 * 4k 8k 16k 400k
935 *
936 * Suppose we drop the lock after reading VMA2 due to
937 * contention, then we get:
938 *
939 * last_vma_end = 16k
940 *
941 * 1) VMA2 is freed, but VMA3 exists:
942 *
943 * vma_next(vmi) will return VMA3.
944 * In this case, just continue from VMA3.
945 *
946 * 2) VMA2 still exists:
947 *
948 * vma_next(vmi) will return VMA3.
949 * In this case, just continue from VMA3.
950 *
951 * 3) No more VMAs can be found:
952 *
953 * vma_next(vmi) will return NULL.
954 * No more things to do, just break.
955 *
956 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
957 *
958 * vma_next(vmi) will return VMA' whose range
959 * contains last_vma_end.
960 * Iterate VMA' from last_vma_end.
961 */
962 vma = vma_next(&vmi);
963 /* Case 3 above */
964 if (!vma)
965 break;
966
967 /* Case 1 and 2 above */
968 if (vma->vm_start >= last_vma_end)
969 continue;
970
971 /* Case 4 above */
972 if (vma->vm_end > last_vma_end)
973 smap_gather_stats(vma, &mss, last_vma_end);
974 }
975 } for_each_vma(vmi, vma);
976
977empty_set:
978 show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
979 seq_pad(m, ' ');
980 seq_puts(m, "[rollup]\n");
981
982 __show_smap(m, &mss, true);
983
984 release_task_mempolicy(priv);
985 mmap_read_unlock(mm);
986
987out_put_mm:
988 mmput(mm);
989out_put_task:
990 put_task_struct(priv->task);
991 priv->task = NULL;
992
993 return ret;
994}
995#undef SEQ_PUT_DEC
996
997static const struct seq_operations proc_pid_smaps_op = {
998 .start = m_start,
999 .next = m_next,
1000 .stop = m_stop,
1001 .show = show_smap
1002};
1003
1004static int pid_smaps_open(struct inode *inode, struct file *file)
1005{
1006 return do_maps_open(inode, file, &proc_pid_smaps_op);
1007}
1008
1009static int smaps_rollup_open(struct inode *inode, struct file *file)
1010{
1011 int ret;
1012 struct proc_maps_private *priv;
1013
1014 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1015 if (!priv)
1016 return -ENOMEM;
1017
1018 ret = single_open(file, show_smaps_rollup, priv);
1019 if (ret)
1020 goto out_free;
1021
1022 priv->inode = inode;
1023 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1024 if (IS_ERR(priv->mm)) {
1025 ret = PTR_ERR(priv->mm);
1026
1027 single_release(inode, file);
1028 goto out_free;
1029 }
1030
1031 return 0;
1032
1033out_free:
1034 kfree(priv);
1035 return ret;
1036}
1037
1038static int smaps_rollup_release(struct inode *inode, struct file *file)
1039{
1040 struct seq_file *seq = file->private_data;
1041 struct proc_maps_private *priv = seq->private;
1042
1043 if (priv->mm)
1044 mmdrop(priv->mm);
1045
1046 kfree(priv);
1047 return single_release(inode, file);
1048}
1049
1050const struct file_operations proc_pid_smaps_operations = {
1051 .open = pid_smaps_open,
1052 .read = seq_read,
1053 .llseek = seq_lseek,
1054 .release = proc_map_release,
1055};
1056
1057const struct file_operations proc_pid_smaps_rollup_operations = {
1058 .open = smaps_rollup_open,
1059 .read = seq_read,
1060 .llseek = seq_lseek,
1061 .release = smaps_rollup_release,
1062};
1063
1064enum clear_refs_types {
1065 CLEAR_REFS_ALL = 1,
1066 CLEAR_REFS_ANON,
1067 CLEAR_REFS_MAPPED,
1068 CLEAR_REFS_SOFT_DIRTY,
1069 CLEAR_REFS_MM_HIWATER_RSS,
1070 CLEAR_REFS_LAST,
1071};
1072
1073struct clear_refs_private {
1074 enum clear_refs_types type;
1075};
1076
1077#ifdef CONFIG_MEM_SOFT_DIRTY
1078
1079static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1080{
1081 struct page *page;
1082
1083 if (!pte_write(pte))
1084 return false;
1085 if (!is_cow_mapping(vma->vm_flags))
1086 return false;
1087 if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
1088 return false;
1089 page = vm_normal_page(vma, addr, pte);
1090 if (!page)
1091 return false;
1092 return page_maybe_dma_pinned(page);
1093}
1094
1095static inline void clear_soft_dirty(struct vm_area_struct *vma,
1096 unsigned long addr, pte_t *pte)
1097{
1098 /*
1099 * The soft-dirty tracker uses #PF-s to catch writes
1100 * to pages, so write-protect the pte as well. See the
1101 * Documentation/admin-guide/mm/soft-dirty.rst for full description
1102 * of how soft-dirty works.
1103 */
1104 pte_t ptent = ptep_get(pte);
1105
1106 if (pte_present(ptent)) {
1107 pte_t old_pte;
1108
1109 if (pte_is_pinned(vma, addr, ptent))
1110 return;
1111 old_pte = ptep_modify_prot_start(vma, addr, pte);
1112 ptent = pte_wrprotect(old_pte);
1113 ptent = pte_clear_soft_dirty(ptent);
1114 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1115 } else if (is_swap_pte(ptent)) {
1116 ptent = pte_swp_clear_soft_dirty(ptent);
1117 set_pte_at(vma->vm_mm, addr, pte, ptent);
1118 }
1119}
1120#else
1121static inline void clear_soft_dirty(struct vm_area_struct *vma,
1122 unsigned long addr, pte_t *pte)
1123{
1124}
1125#endif
1126
1127#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1128static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1129 unsigned long addr, pmd_t *pmdp)
1130{
1131 pmd_t old, pmd = *pmdp;
1132
1133 if (pmd_present(pmd)) {
1134 /* See comment in change_huge_pmd() */
1135 old = pmdp_invalidate(vma, addr, pmdp);
1136 if (pmd_dirty(old))
1137 pmd = pmd_mkdirty(pmd);
1138 if (pmd_young(old))
1139 pmd = pmd_mkyoung(pmd);
1140
1141 pmd = pmd_wrprotect(pmd);
1142 pmd = pmd_clear_soft_dirty(pmd);
1143
1144 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1145 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1146 pmd = pmd_swp_clear_soft_dirty(pmd);
1147 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1148 }
1149}
1150#else
1151static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1152 unsigned long addr, pmd_t *pmdp)
1153{
1154}
1155#endif
1156
1157static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
1158 unsigned long end, struct mm_walk *walk)
1159{
1160 struct clear_refs_private *cp = walk->private;
1161 struct vm_area_struct *vma = walk->vma;
1162 pte_t *pte, ptent;
1163 spinlock_t *ptl;
1164 struct page *page;
1165
1166 ptl = pmd_trans_huge_lock(pmd, vma);
1167 if (ptl) {
1168 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1169 clear_soft_dirty_pmd(vma, addr, pmd);
1170 goto out;
1171 }
1172
1173 if (!pmd_present(*pmd))
1174 goto out;
1175
1176 page = pmd_page(*pmd);
1177
1178 /* Clear accessed and referenced bits. */
1179 pmdp_test_and_clear_young(vma, addr, pmd);
1180 test_and_clear_page_young(page);
1181 ClearPageReferenced(page);
1182out:
1183 spin_unlock(ptl);
1184 return 0;
1185 }
1186
1187 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
1188 if (!pte) {
1189 walk->action = ACTION_AGAIN;
1190 return 0;
1191 }
1192 for (; addr != end; pte++, addr += PAGE_SIZE) {
1193 ptent = ptep_get(pte);
1194
1195 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1196 clear_soft_dirty(vma, addr, pte);
1197 continue;
1198 }
1199
1200 if (!pte_present(ptent))
1201 continue;
1202
1203 page = vm_normal_page(vma, addr, ptent);
1204 if (!page)
1205 continue;
1206
1207 /* Clear accessed and referenced bits. */
1208 ptep_test_and_clear_young(vma, addr, pte);
1209 test_and_clear_page_young(page);
1210 ClearPageReferenced(page);
1211 }
1212 pte_unmap_unlock(pte - 1, ptl);
1213 cond_resched();
1214 return 0;
1215}
1216
1217static int clear_refs_test_walk(unsigned long start, unsigned long end,
1218 struct mm_walk *walk)
1219{
1220 struct clear_refs_private *cp = walk->private;
1221 struct vm_area_struct *vma = walk->vma;
1222
1223 if (vma->vm_flags & VM_PFNMAP)
1224 return 1;
1225
1226 /*
1227 * Writing 1 to /proc/pid/clear_refs affects all pages.
1228 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1229 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1230 * Writing 4 to /proc/pid/clear_refs affects all pages.
1231 */
1232 if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1233 return 1;
1234 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1235 return 1;
1236 return 0;
1237}
1238
1239static const struct mm_walk_ops clear_refs_walk_ops = {
1240 .pmd_entry = clear_refs_pte_range,
1241 .test_walk = clear_refs_test_walk,
1242 .walk_lock = PGWALK_WRLOCK,
1243};
1244
1245static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1246 size_t count, loff_t *ppos)
1247{
1248 struct task_struct *task;
1249 char buffer[PROC_NUMBUF] = {};
1250 struct mm_struct *mm;
1251 struct vm_area_struct *vma;
1252 enum clear_refs_types type;
1253 int itype;
1254 int rv;
1255
1256 if (count > sizeof(buffer) - 1)
1257 count = sizeof(buffer) - 1;
1258 if (copy_from_user(buffer, buf, count))
1259 return -EFAULT;
1260 rv = kstrtoint(strstrip(buffer), 10, &itype);
1261 if (rv < 0)
1262 return rv;
1263 type = (enum clear_refs_types)itype;
1264 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
1265 return -EINVAL;
1266
1267 task = get_proc_task(file_inode(file));
1268 if (!task)
1269 return -ESRCH;
1270 mm = get_task_mm(task);
1271 if (mm) {
1272 VMA_ITERATOR(vmi, mm, 0);
1273 struct mmu_notifier_range range;
1274 struct clear_refs_private cp = {
1275 .type = type,
1276 };
1277
1278 if (mmap_write_lock_killable(mm)) {
1279 count = -EINTR;
1280 goto out_mm;
1281 }
1282 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1283 /*
1284 * Writing 5 to /proc/pid/clear_refs resets the peak
1285 * resident set size to this mm's current rss value.
1286 */
1287 reset_mm_hiwater_rss(mm);
1288 goto out_unlock;
1289 }
1290
1291 if (type == CLEAR_REFS_SOFT_DIRTY) {
1292 for_each_vma(vmi, vma) {
1293 if (!(vma->vm_flags & VM_SOFTDIRTY))
1294 continue;
1295 vm_flags_clear(vma, VM_SOFTDIRTY);
1296 vma_set_page_prot(vma);
1297 }
1298
1299 inc_tlb_flush_pending(mm);
1300 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
1301 0, mm, 0, -1UL);
1302 mmu_notifier_invalidate_range_start(&range);
1303 }
1304 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
1305 if (type == CLEAR_REFS_SOFT_DIRTY) {
1306 mmu_notifier_invalidate_range_end(&range);
1307 flush_tlb_mm(mm);
1308 dec_tlb_flush_pending(mm);
1309 }
1310out_unlock:
1311 mmap_write_unlock(mm);
1312out_mm:
1313 mmput(mm);
1314 }
1315 put_task_struct(task);
1316
1317 return count;
1318}
1319
1320const struct file_operations proc_clear_refs_operations = {
1321 .write = clear_refs_write,
1322 .llseek = noop_llseek,
1323};
1324
1325typedef struct {
1326 u64 pme;
1327} pagemap_entry_t;
1328
1329struct pagemapread {
1330 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */
1331 pagemap_entry_t *buffer;
1332 bool show_pfn;
1333};
1334
1335#define PAGEMAP_WALK_SIZE (PMD_SIZE)
1336#define PAGEMAP_WALK_MASK (PMD_MASK)
1337
1338#define PM_ENTRY_BYTES sizeof(pagemap_entry_t)
1339#define PM_PFRAME_BITS 55
1340#define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1341#define PM_SOFT_DIRTY BIT_ULL(55)
1342#define PM_MMAP_EXCLUSIVE BIT_ULL(56)
1343#define PM_UFFD_WP BIT_ULL(57)
1344#define PM_FILE BIT_ULL(61)
1345#define PM_SWAP BIT_ULL(62)
1346#define PM_PRESENT BIT_ULL(63)
1347
1348#define PM_END_OF_BUFFER 1
1349
1350static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
1351{
1352 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
1353}
1354
1355static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
1356 struct pagemapread *pm)
1357{
1358 pm->buffer[pm->pos++] = *pme;
1359 if (pm->pos >= pm->len)
1360 return PM_END_OF_BUFFER;
1361 return 0;
1362}
1363
1364static int pagemap_pte_hole(unsigned long start, unsigned long end,
1365 __always_unused int depth, struct mm_walk *walk)
1366{
1367 struct pagemapread *pm = walk->private;
1368 unsigned long addr = start;
1369 int err = 0;
1370
1371 while (addr < end) {
1372 struct vm_area_struct *vma = find_vma(walk->mm, addr);
1373 pagemap_entry_t pme = make_pme(0, 0);
1374 /* End of address space hole, which we mark as non-present. */
1375 unsigned long hole_end;
1376
1377 if (vma)
1378 hole_end = min(end, vma->vm_start);
1379 else
1380 hole_end = end;
1381
1382 for (; addr < hole_end; addr += PAGE_SIZE) {
1383 err = add_to_pagemap(addr, &pme, pm);
1384 if (err)
1385 goto out;
1386 }
1387
1388 if (!vma)
1389 break;
1390
1391 /* Addresses in the VMA. */
1392 if (vma->vm_flags & VM_SOFTDIRTY)
1393 pme = make_pme(0, PM_SOFT_DIRTY);
1394 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
1395 err = add_to_pagemap(addr, &pme, pm);
1396 if (err)
1397 goto out;
1398 }
1399 }
1400out:
1401 return err;
1402}
1403
1404static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
1405 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1406{
1407 u64 frame = 0, flags = 0;
1408 struct page *page = NULL;
1409 bool migration = false;
1410
1411 if (pte_present(pte)) {
1412 if (pm->show_pfn)
1413 frame = pte_pfn(pte);
1414 flags |= PM_PRESENT;
1415 page = vm_normal_page(vma, addr, pte);
1416 if (pte_soft_dirty(pte))
1417 flags |= PM_SOFT_DIRTY;
1418 if (pte_uffd_wp(pte))
1419 flags |= PM_UFFD_WP;
1420 } else if (is_swap_pte(pte)) {
1421 swp_entry_t entry;
1422 if (pte_swp_soft_dirty(pte))
1423 flags |= PM_SOFT_DIRTY;
1424 if (pte_swp_uffd_wp(pte))
1425 flags |= PM_UFFD_WP;
1426 entry = pte_to_swp_entry(pte);
1427 if (pm->show_pfn) {
1428 pgoff_t offset;
1429 /*
1430 * For PFN swap offsets, keeping the offset field
1431 * to be PFN only to be compatible with old smaps.
1432 */
1433 if (is_pfn_swap_entry(entry))
1434 offset = swp_offset_pfn(entry);
1435 else
1436 offset = swp_offset(entry);
1437 frame = swp_type(entry) |
1438 (offset << MAX_SWAPFILES_SHIFT);
1439 }
1440 flags |= PM_SWAP;
1441 migration = is_migration_entry(entry);
1442 if (is_pfn_swap_entry(entry))
1443 page = pfn_swap_entry_to_page(entry);
1444 if (pte_marker_entry_uffd_wp(entry))
1445 flags |= PM_UFFD_WP;
1446 }
1447
1448 if (page && !PageAnon(page))
1449 flags |= PM_FILE;
1450 if (page && !migration && page_mapcount(page) == 1)
1451 flags |= PM_MMAP_EXCLUSIVE;
1452 if (vma->vm_flags & VM_SOFTDIRTY)
1453 flags |= PM_SOFT_DIRTY;
1454
1455 return make_pme(frame, flags);
1456}
1457
1458static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
1459 struct mm_walk *walk)
1460{
1461 struct vm_area_struct *vma = walk->vma;
1462 struct pagemapread *pm = walk->private;
1463 spinlock_t *ptl;
1464 pte_t *pte, *orig_pte;
1465 int err = 0;
1466#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1467 bool migration = false;
1468
1469 ptl = pmd_trans_huge_lock(pmdp, vma);
1470 if (ptl) {
1471 u64 flags = 0, frame = 0;
1472 pmd_t pmd = *pmdp;
1473 struct page *page = NULL;
1474
1475 if (vma->vm_flags & VM_SOFTDIRTY)
1476 flags |= PM_SOFT_DIRTY;
1477
1478 if (pmd_present(pmd)) {
1479 page = pmd_page(pmd);
1480
1481 flags |= PM_PRESENT;
1482 if (pmd_soft_dirty(pmd))
1483 flags |= PM_SOFT_DIRTY;
1484 if (pmd_uffd_wp(pmd))
1485 flags |= PM_UFFD_WP;
1486 if (pm->show_pfn)
1487 frame = pmd_pfn(pmd) +
1488 ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1489 }
1490#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1491 else if (is_swap_pmd(pmd)) {
1492 swp_entry_t entry = pmd_to_swp_entry(pmd);
1493 unsigned long offset;
1494
1495 if (pm->show_pfn) {
1496 if (is_pfn_swap_entry(entry))
1497 offset = swp_offset_pfn(entry);
1498 else
1499 offset = swp_offset(entry);
1500 offset = offset +
1501 ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1502 frame = swp_type(entry) |
1503 (offset << MAX_SWAPFILES_SHIFT);
1504 }
1505 flags |= PM_SWAP;
1506 if (pmd_swp_soft_dirty(pmd))
1507 flags |= PM_SOFT_DIRTY;
1508 if (pmd_swp_uffd_wp(pmd))
1509 flags |= PM_UFFD_WP;
1510 VM_BUG_ON(!is_pmd_migration_entry(pmd));
1511 migration = is_migration_entry(entry);
1512 page = pfn_swap_entry_to_page(entry);
1513 }
1514#endif
1515
1516 if (page && !migration && page_mapcount(page) == 1)
1517 flags |= PM_MMAP_EXCLUSIVE;
1518
1519 for (; addr != end; addr += PAGE_SIZE) {
1520 pagemap_entry_t pme = make_pme(frame, flags);
1521
1522 err = add_to_pagemap(addr, &pme, pm);
1523 if (err)
1524 break;
1525 if (pm->show_pfn) {
1526 if (flags & PM_PRESENT)
1527 frame++;
1528 else if (flags & PM_SWAP)
1529 frame += (1 << MAX_SWAPFILES_SHIFT);
1530 }
1531 }
1532 spin_unlock(ptl);
1533 return err;
1534 }
1535#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1536
1537 /*
1538 * We can assume that @vma always points to a valid one and @end never
1539 * goes beyond vma->vm_end.
1540 */
1541 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
1542 if (!pte) {
1543 walk->action = ACTION_AGAIN;
1544 return err;
1545 }
1546 for (; addr < end; pte++, addr += PAGE_SIZE) {
1547 pagemap_entry_t pme;
1548
1549 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
1550 err = add_to_pagemap(addr, &pme, pm);
1551 if (err)
1552 break;
1553 }
1554 pte_unmap_unlock(orig_pte, ptl);
1555
1556 cond_resched();
1557
1558 return err;
1559}
1560
1561#ifdef CONFIG_HUGETLB_PAGE
1562/* This function walks within one hugetlb entry in the single call */
1563static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
1564 unsigned long addr, unsigned long end,
1565 struct mm_walk *walk)
1566{
1567 struct pagemapread *pm = walk->private;
1568 struct vm_area_struct *vma = walk->vma;
1569 u64 flags = 0, frame = 0;
1570 int err = 0;
1571 pte_t pte;
1572
1573 if (vma->vm_flags & VM_SOFTDIRTY)
1574 flags |= PM_SOFT_DIRTY;
1575
1576 pte = huge_ptep_get(ptep);
1577 if (pte_present(pte)) {
1578 struct page *page = pte_page(pte);
1579
1580 if (!PageAnon(page))
1581 flags |= PM_FILE;
1582
1583 if (page_mapcount(page) == 1)
1584 flags |= PM_MMAP_EXCLUSIVE;
1585
1586 if (huge_pte_uffd_wp(pte))
1587 flags |= PM_UFFD_WP;
1588
1589 flags |= PM_PRESENT;
1590 if (pm->show_pfn)
1591 frame = pte_pfn(pte) +
1592 ((addr & ~hmask) >> PAGE_SHIFT);
1593 } else if (pte_swp_uffd_wp_any(pte)) {
1594 flags |= PM_UFFD_WP;
1595 }
1596
1597 for (; addr != end; addr += PAGE_SIZE) {
1598 pagemap_entry_t pme = make_pme(frame, flags);
1599
1600 err = add_to_pagemap(addr, &pme, pm);
1601 if (err)
1602 return err;
1603 if (pm->show_pfn && (flags & PM_PRESENT))
1604 frame++;
1605 }
1606
1607 cond_resched();
1608
1609 return err;
1610}
1611#else
1612#define pagemap_hugetlb_range NULL
1613#endif /* HUGETLB_PAGE */
1614
1615static const struct mm_walk_ops pagemap_ops = {
1616 .pmd_entry = pagemap_pmd_range,
1617 .pte_hole = pagemap_pte_hole,
1618 .hugetlb_entry = pagemap_hugetlb_range,
1619 .walk_lock = PGWALK_RDLOCK,
1620};
1621
1622/*
1623 * /proc/pid/pagemap - an array mapping virtual pages to pfns
1624 *
1625 * For each page in the address space, this file contains one 64-bit entry
1626 * consisting of the following:
1627 *
1628 * Bits 0-54 page frame number (PFN) if present
1629 * Bits 0-4 swap type if swapped
1630 * Bits 5-54 swap offset if swapped
1631 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
1632 * Bit 56 page exclusively mapped
1633 * Bit 57 pte is uffd-wp write-protected
1634 * Bits 58-60 zero
1635 * Bit 61 page is file-page or shared-anon
1636 * Bit 62 page swapped
1637 * Bit 63 page present
1638 *
1639 * If the page is not present but in swap, then the PFN contains an
1640 * encoding of the swap file number and the page's offset into the
1641 * swap. Unmapped pages return a null PFN. This allows determining
1642 * precisely which pages are mapped (or in swap) and comparing mapped
1643 * pages between processes.
1644 *
1645 * Efficient users of this interface will use /proc/pid/maps to
1646 * determine which areas of memory are actually mapped and llseek to
1647 * skip over unmapped regions.
1648 */
1649static ssize_t pagemap_read(struct file *file, char __user *buf,
1650 size_t count, loff_t *ppos)
1651{
1652 struct mm_struct *mm = file->private_data;
1653 struct pagemapread pm;
1654 unsigned long src;
1655 unsigned long svpfn;
1656 unsigned long start_vaddr;
1657 unsigned long end_vaddr;
1658 int ret = 0, copied = 0;
1659
1660 if (!mm || !mmget_not_zero(mm))
1661 goto out;
1662
1663 ret = -EINVAL;
1664 /* file position must be aligned */
1665 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
1666 goto out_mm;
1667
1668 ret = 0;
1669 if (!count)
1670 goto out_mm;
1671
1672 /* do not disclose physical addresses: attack vector */
1673 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1674
1675 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
1676 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
1677 ret = -ENOMEM;
1678 if (!pm.buffer)
1679 goto out_mm;
1680
1681 src = *ppos;
1682 svpfn = src / PM_ENTRY_BYTES;
1683 end_vaddr = mm->task_size;
1684
1685 /* watch out for wraparound */
1686 start_vaddr = end_vaddr;
1687 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
1688 unsigned long end;
1689
1690 ret = mmap_read_lock_killable(mm);
1691 if (ret)
1692 goto out_free;
1693 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1694 mmap_read_unlock(mm);
1695
1696 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1697 if (end >= start_vaddr && end < mm->task_size)
1698 end_vaddr = end;
1699 }
1700
1701 /* Ensure the address is inside the task */
1702 if (start_vaddr > mm->task_size)
1703 start_vaddr = end_vaddr;
1704
1705 ret = 0;
1706 while (count && (start_vaddr < end_vaddr)) {
1707 int len;
1708 unsigned long end;
1709
1710 pm.pos = 0;
1711 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
1712 /* overflow ? */
1713 if (end < start_vaddr || end > end_vaddr)
1714 end = end_vaddr;
1715 ret = mmap_read_lock_killable(mm);
1716 if (ret)
1717 goto out_free;
1718 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
1719 mmap_read_unlock(mm);
1720 start_vaddr = end;
1721
1722 len = min(count, PM_ENTRY_BYTES * pm.pos);
1723 if (copy_to_user(buf, pm.buffer, len)) {
1724 ret = -EFAULT;
1725 goto out_free;
1726 }
1727 copied += len;
1728 buf += len;
1729 count -= len;
1730 }
1731 *ppos += copied;
1732 if (!ret || ret == PM_END_OF_BUFFER)
1733 ret = copied;
1734
1735out_free:
1736 kfree(pm.buffer);
1737out_mm:
1738 mmput(mm);
1739out:
1740 return ret;
1741}
1742
1743static int pagemap_open(struct inode *inode, struct file *file)
1744{
1745 struct mm_struct *mm;
1746
1747 mm = proc_mem_open(inode, PTRACE_MODE_READ);
1748 if (IS_ERR(mm))
1749 return PTR_ERR(mm);
1750 file->private_data = mm;
1751 return 0;
1752}
1753
1754static int pagemap_release(struct inode *inode, struct file *file)
1755{
1756 struct mm_struct *mm = file->private_data;
1757
1758 if (mm)
1759 mmdrop(mm);
1760 return 0;
1761}
1762
1763#define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \
1764 PAGE_IS_FILE | PAGE_IS_PRESENT | \
1765 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \
1766 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY)
1767#define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC)
1768
1769struct pagemap_scan_private {
1770 struct pm_scan_arg arg;
1771 unsigned long masks_of_interest, cur_vma_category;
1772 struct page_region *vec_buf;
1773 unsigned long vec_buf_len, vec_buf_index, found_pages;
1774 struct page_region __user *vec_out;
1775};
1776
1777static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
1778 struct vm_area_struct *vma,
1779 unsigned long addr, pte_t pte)
1780{
1781 unsigned long categories = 0;
1782
1783 if (pte_present(pte)) {
1784 struct page *page;
1785
1786 categories |= PAGE_IS_PRESENT;
1787 if (!pte_uffd_wp(pte))
1788 categories |= PAGE_IS_WRITTEN;
1789
1790 if (p->masks_of_interest & PAGE_IS_FILE) {
1791 page = vm_normal_page(vma, addr, pte);
1792 if (page && !PageAnon(page))
1793 categories |= PAGE_IS_FILE;
1794 }
1795
1796 if (is_zero_pfn(pte_pfn(pte)))
1797 categories |= PAGE_IS_PFNZERO;
1798 if (pte_soft_dirty(pte))
1799 categories |= PAGE_IS_SOFT_DIRTY;
1800 } else if (is_swap_pte(pte)) {
1801 swp_entry_t swp;
1802
1803 categories |= PAGE_IS_SWAPPED;
1804 if (!pte_swp_uffd_wp_any(pte))
1805 categories |= PAGE_IS_WRITTEN;
1806
1807 if (p->masks_of_interest & PAGE_IS_FILE) {
1808 swp = pte_to_swp_entry(pte);
1809 if (is_pfn_swap_entry(swp) &&
1810 !PageAnon(pfn_swap_entry_to_page(swp)))
1811 categories |= PAGE_IS_FILE;
1812 }
1813 if (pte_swp_soft_dirty(pte))
1814 categories |= PAGE_IS_SOFT_DIRTY;
1815 }
1816
1817 return categories;
1818}
1819
1820static void make_uffd_wp_pte(struct vm_area_struct *vma,
1821 unsigned long addr, pte_t *pte)
1822{
1823 pte_t ptent = ptep_get(pte);
1824
1825 if (pte_present(ptent)) {
1826 pte_t old_pte;
1827
1828 old_pte = ptep_modify_prot_start(vma, addr, pte);
1829 ptent = pte_mkuffd_wp(ptent);
1830 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1831 } else if (is_swap_pte(ptent)) {
1832 ptent = pte_swp_mkuffd_wp(ptent);
1833 set_pte_at(vma->vm_mm, addr, pte, ptent);
1834 } else {
1835 set_pte_at(vma->vm_mm, addr, pte,
1836 make_pte_marker(PTE_MARKER_UFFD_WP));
1837 }
1838}
1839
1840#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1841static unsigned long pagemap_thp_category(struct pagemap_scan_private *p,
1842 struct vm_area_struct *vma,
1843 unsigned long addr, pmd_t pmd)
1844{
1845 unsigned long categories = PAGE_IS_HUGE;
1846
1847 if (pmd_present(pmd)) {
1848 struct page *page;
1849
1850 categories |= PAGE_IS_PRESENT;
1851 if (!pmd_uffd_wp(pmd))
1852 categories |= PAGE_IS_WRITTEN;
1853
1854 if (p->masks_of_interest & PAGE_IS_FILE) {
1855 page = vm_normal_page_pmd(vma, addr, pmd);
1856 if (page && !PageAnon(page))
1857 categories |= PAGE_IS_FILE;
1858 }
1859
1860 if (is_zero_pfn(pmd_pfn(pmd)))
1861 categories |= PAGE_IS_PFNZERO;
1862 if (pmd_soft_dirty(pmd))
1863 categories |= PAGE_IS_SOFT_DIRTY;
1864 } else if (is_swap_pmd(pmd)) {
1865 swp_entry_t swp;
1866
1867 categories |= PAGE_IS_SWAPPED;
1868 if (!pmd_swp_uffd_wp(pmd))
1869 categories |= PAGE_IS_WRITTEN;
1870 if (pmd_swp_soft_dirty(pmd))
1871 categories |= PAGE_IS_SOFT_DIRTY;
1872
1873 if (p->masks_of_interest & PAGE_IS_FILE) {
1874 swp = pmd_to_swp_entry(pmd);
1875 if (is_pfn_swap_entry(swp) &&
1876 !PageAnon(pfn_swap_entry_to_page(swp)))
1877 categories |= PAGE_IS_FILE;
1878 }
1879 }
1880
1881 return categories;
1882}
1883
1884static void make_uffd_wp_pmd(struct vm_area_struct *vma,
1885 unsigned long addr, pmd_t *pmdp)
1886{
1887 pmd_t old, pmd = *pmdp;
1888
1889 if (pmd_present(pmd)) {
1890 old = pmdp_invalidate_ad(vma, addr, pmdp);
1891 pmd = pmd_mkuffd_wp(old);
1892 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1893 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1894 pmd = pmd_swp_mkuffd_wp(pmd);
1895 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1896 }
1897}
1898#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1899
1900#ifdef CONFIG_HUGETLB_PAGE
1901static unsigned long pagemap_hugetlb_category(pte_t pte)
1902{
1903 unsigned long categories = PAGE_IS_HUGE;
1904
1905 /*
1906 * According to pagemap_hugetlb_range(), file-backed HugeTLB
1907 * page cannot be swapped. So PAGE_IS_FILE is not checked for
1908 * swapped pages.
1909 */
1910 if (pte_present(pte)) {
1911 categories |= PAGE_IS_PRESENT;
1912 if (!huge_pte_uffd_wp(pte))
1913 categories |= PAGE_IS_WRITTEN;
1914 if (!PageAnon(pte_page(pte)))
1915 categories |= PAGE_IS_FILE;
1916 if (is_zero_pfn(pte_pfn(pte)))
1917 categories |= PAGE_IS_PFNZERO;
1918 if (pte_soft_dirty(pte))
1919 categories |= PAGE_IS_SOFT_DIRTY;
1920 } else if (is_swap_pte(pte)) {
1921 categories |= PAGE_IS_SWAPPED;
1922 if (!pte_swp_uffd_wp_any(pte))
1923 categories |= PAGE_IS_WRITTEN;
1924 if (pte_swp_soft_dirty(pte))
1925 categories |= PAGE_IS_SOFT_DIRTY;
1926 }
1927
1928 return categories;
1929}
1930
1931static void make_uffd_wp_huge_pte(struct vm_area_struct *vma,
1932 unsigned long addr, pte_t *ptep,
1933 pte_t ptent)
1934{
1935 unsigned long psize;
1936
1937 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent))
1938 return;
1939
1940 psize = huge_page_size(hstate_vma(vma));
1941
1942 if (is_hugetlb_entry_migration(ptent))
1943 set_huge_pte_at(vma->vm_mm, addr, ptep,
1944 pte_swp_mkuffd_wp(ptent), psize);
1945 else if (!huge_pte_none(ptent))
1946 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent,
1947 huge_pte_mkuffd_wp(ptent));
1948 else
1949 set_huge_pte_at(vma->vm_mm, addr, ptep,
1950 make_pte_marker(PTE_MARKER_UFFD_WP), psize);
1951}
1952#endif /* CONFIG_HUGETLB_PAGE */
1953
1954#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
1955static void pagemap_scan_backout_range(struct pagemap_scan_private *p,
1956 unsigned long addr, unsigned long end)
1957{
1958 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
1959
1960 if (cur_buf->start != addr)
1961 cur_buf->end = addr;
1962 else
1963 cur_buf->start = cur_buf->end = 0;
1964
1965 p->found_pages -= (end - addr) / PAGE_SIZE;
1966}
1967#endif
1968
1969static bool pagemap_scan_is_interesting_page(unsigned long categories,
1970 const struct pagemap_scan_private *p)
1971{
1972 categories ^= p->arg.category_inverted;
1973 if ((categories & p->arg.category_mask) != p->arg.category_mask)
1974 return false;
1975 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask))
1976 return false;
1977
1978 return true;
1979}
1980
1981static bool pagemap_scan_is_interesting_vma(unsigned long categories,
1982 const struct pagemap_scan_private *p)
1983{
1984 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED;
1985
1986 categories ^= p->arg.category_inverted;
1987 if ((categories & required) != required)
1988 return false;
1989
1990 return true;
1991}
1992
1993static int pagemap_scan_test_walk(unsigned long start, unsigned long end,
1994 struct mm_walk *walk)
1995{
1996 struct pagemap_scan_private *p = walk->private;
1997 struct vm_area_struct *vma = walk->vma;
1998 unsigned long vma_category = 0;
1999 bool wp_allowed = userfaultfd_wp_async(vma) &&
2000 userfaultfd_wp_use_markers(vma);
2001
2002 if (!wp_allowed) {
2003 /* User requested explicit failure over wp-async capability */
2004 if (p->arg.flags & PM_SCAN_CHECK_WPASYNC)
2005 return -EPERM;
2006 /*
2007 * User requires wr-protect, and allows silently skipping
2008 * unsupported vmas.
2009 */
2010 if (p->arg.flags & PM_SCAN_WP_MATCHING)
2011 return 1;
2012 /*
2013 * Then the request doesn't involve wr-protects at all,
2014 * fall through to the rest checks, and allow vma walk.
2015 */
2016 }
2017
2018 if (vma->vm_flags & VM_PFNMAP)
2019 return 1;
2020
2021 if (wp_allowed)
2022 vma_category |= PAGE_IS_WPALLOWED;
2023
2024 if (vma->vm_flags & VM_SOFTDIRTY)
2025 vma_category |= PAGE_IS_SOFT_DIRTY;
2026
2027 if (!pagemap_scan_is_interesting_vma(vma_category, p))
2028 return 1;
2029
2030 p->cur_vma_category = vma_category;
2031
2032 return 0;
2033}
2034
2035static bool pagemap_scan_push_range(unsigned long categories,
2036 struct pagemap_scan_private *p,
2037 unsigned long addr, unsigned long end)
2038{
2039 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
2040
2041 /*
2042 * When there is no output buffer provided at all, the sentinel values
2043 * won't match here. There is no other way for `cur_buf->end` to be
2044 * non-zero other than it being non-empty.
2045 */
2046 if (addr == cur_buf->end && categories == cur_buf->categories) {
2047 cur_buf->end = end;
2048 return true;
2049 }
2050
2051 if (cur_buf->end) {
2052 if (p->vec_buf_index >= p->vec_buf_len - 1)
2053 return false;
2054
2055 cur_buf = &p->vec_buf[++p->vec_buf_index];
2056 }
2057
2058 cur_buf->start = addr;
2059 cur_buf->end = end;
2060 cur_buf->categories = categories;
2061
2062 return true;
2063}
2064
2065static int pagemap_scan_output(unsigned long categories,
2066 struct pagemap_scan_private *p,
2067 unsigned long addr, unsigned long *end)
2068{
2069 unsigned long n_pages, total_pages;
2070 int ret = 0;
2071
2072 if (!p->vec_buf)
2073 return 0;
2074
2075 categories &= p->arg.return_mask;
2076
2077 n_pages = (*end - addr) / PAGE_SIZE;
2078 if (check_add_overflow(p->found_pages, n_pages, &total_pages) ||
2079 total_pages > p->arg.max_pages) {
2080 size_t n_too_much = total_pages - p->arg.max_pages;
2081 *end -= n_too_much * PAGE_SIZE;
2082 n_pages -= n_too_much;
2083 ret = -ENOSPC;
2084 }
2085
2086 if (!pagemap_scan_push_range(categories, p, addr, *end)) {
2087 *end = addr;
2088 n_pages = 0;
2089 ret = -ENOSPC;
2090 }
2091
2092 p->found_pages += n_pages;
2093 if (ret)
2094 p->arg.walk_end = *end;
2095
2096 return ret;
2097}
2098
2099static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start,
2100 unsigned long end, struct mm_walk *walk)
2101{
2102#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2103 struct pagemap_scan_private *p = walk->private;
2104 struct vm_area_struct *vma = walk->vma;
2105 unsigned long categories;
2106 spinlock_t *ptl;
2107 int ret = 0;
2108
2109 ptl = pmd_trans_huge_lock(pmd, vma);
2110 if (!ptl)
2111 return -ENOENT;
2112
2113 categories = p->cur_vma_category |
2114 pagemap_thp_category(p, vma, start, *pmd);
2115
2116 if (!pagemap_scan_is_interesting_page(categories, p))
2117 goto out_unlock;
2118
2119 ret = pagemap_scan_output(categories, p, start, &end);
2120 if (start == end)
2121 goto out_unlock;
2122
2123 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2124 goto out_unlock;
2125 if (~categories & PAGE_IS_WRITTEN)
2126 goto out_unlock;
2127
2128 /*
2129 * Break huge page into small pages if the WP operation
2130 * needs to be performed on a portion of the huge page.
2131 */
2132 if (end != start + HPAGE_SIZE) {
2133 spin_unlock(ptl);
2134 split_huge_pmd(vma, pmd, start);
2135 pagemap_scan_backout_range(p, start, end);
2136 /* Report as if there was no THP */
2137 return -ENOENT;
2138 }
2139
2140 make_uffd_wp_pmd(vma, start, pmd);
2141 flush_tlb_range(vma, start, end);
2142out_unlock:
2143 spin_unlock(ptl);
2144 return ret;
2145#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
2146 return -ENOENT;
2147#endif
2148}
2149
2150static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
2151 unsigned long end, struct mm_walk *walk)
2152{
2153 struct pagemap_scan_private *p = walk->private;
2154 struct vm_area_struct *vma = walk->vma;
2155 unsigned long addr, flush_end = 0;
2156 pte_t *pte, *start_pte;
2157 spinlock_t *ptl;
2158 int ret;
2159
2160 arch_enter_lazy_mmu_mode();
2161
2162 ret = pagemap_scan_thp_entry(pmd, start, end, walk);
2163 if (ret != -ENOENT) {
2164 arch_leave_lazy_mmu_mode();
2165 return ret;
2166 }
2167
2168 ret = 0;
2169 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl);
2170 if (!pte) {
2171 arch_leave_lazy_mmu_mode();
2172 walk->action = ACTION_AGAIN;
2173 return 0;
2174 }
2175
2176 if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) {
2177 /* Fast path for performing exclusive WP */
2178 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
2179 if (pte_uffd_wp(ptep_get(pte)))
2180 continue;
2181 make_uffd_wp_pte(vma, addr, pte);
2182 if (!flush_end)
2183 start = addr;
2184 flush_end = addr + PAGE_SIZE;
2185 }
2186 goto flush_and_return;
2187 }
2188
2189 if (!p->arg.category_anyof_mask && !p->arg.category_inverted &&
2190 p->arg.category_mask == PAGE_IS_WRITTEN &&
2191 p->arg.return_mask == PAGE_IS_WRITTEN) {
2192 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) {
2193 unsigned long next = addr + PAGE_SIZE;
2194
2195 if (pte_uffd_wp(ptep_get(pte)))
2196 continue;
2197 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN,
2198 p, addr, &next);
2199 if (next == addr)
2200 break;
2201 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2202 continue;
2203 make_uffd_wp_pte(vma, addr, pte);
2204 if (!flush_end)
2205 start = addr;
2206 flush_end = next;
2207 }
2208 goto flush_and_return;
2209 }
2210
2211 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
2212 unsigned long categories = p->cur_vma_category |
2213 pagemap_page_category(p, vma, addr, ptep_get(pte));
2214 unsigned long next = addr + PAGE_SIZE;
2215
2216 if (!pagemap_scan_is_interesting_page(categories, p))
2217 continue;
2218
2219 ret = pagemap_scan_output(categories, p, addr, &next);
2220 if (next == addr)
2221 break;
2222
2223 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2224 continue;
2225 if (~categories & PAGE_IS_WRITTEN)
2226 continue;
2227
2228 make_uffd_wp_pte(vma, addr, pte);
2229 if (!flush_end)
2230 start = addr;
2231 flush_end = next;
2232 }
2233
2234flush_and_return:
2235 if (flush_end)
2236 flush_tlb_range(vma, start, addr);
2237
2238 pte_unmap_unlock(start_pte, ptl);
2239 arch_leave_lazy_mmu_mode();
2240
2241 cond_resched();
2242 return ret;
2243}
2244
2245#ifdef CONFIG_HUGETLB_PAGE
2246static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
2247 unsigned long start, unsigned long end,
2248 struct mm_walk *walk)
2249{
2250 struct pagemap_scan_private *p = walk->private;
2251 struct vm_area_struct *vma = walk->vma;
2252 unsigned long categories;
2253 spinlock_t *ptl;
2254 int ret = 0;
2255 pte_t pte;
2256
2257 if (~p->arg.flags & PM_SCAN_WP_MATCHING) {
2258 /* Go the short route when not write-protecting pages. */
2259
2260 pte = huge_ptep_get(ptep);
2261 categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
2262
2263 if (!pagemap_scan_is_interesting_page(categories, p))
2264 return 0;
2265
2266 return pagemap_scan_output(categories, p, start, &end);
2267 }
2268
2269 i_mmap_lock_write(vma->vm_file->f_mapping);
2270 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep);
2271
2272 pte = huge_ptep_get(ptep);
2273 categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
2274
2275 if (!pagemap_scan_is_interesting_page(categories, p))
2276 goto out_unlock;
2277
2278 ret = pagemap_scan_output(categories, p, start, &end);
2279 if (start == end)
2280 goto out_unlock;
2281
2282 if (~categories & PAGE_IS_WRITTEN)
2283 goto out_unlock;
2284
2285 if (end != start + HPAGE_SIZE) {
2286 /* Partial HugeTLB page WP isn't possible. */
2287 pagemap_scan_backout_range(p, start, end);
2288 p->arg.walk_end = start;
2289 ret = 0;
2290 goto out_unlock;
2291 }
2292
2293 make_uffd_wp_huge_pte(vma, start, ptep, pte);
2294 flush_hugetlb_tlb_range(vma, start, end);
2295
2296out_unlock:
2297 spin_unlock(ptl);
2298 i_mmap_unlock_write(vma->vm_file->f_mapping);
2299
2300 return ret;
2301}
2302#else
2303#define pagemap_scan_hugetlb_entry NULL
2304#endif
2305
2306static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end,
2307 int depth, struct mm_walk *walk)
2308{
2309 struct pagemap_scan_private *p = walk->private;
2310 struct vm_area_struct *vma = walk->vma;
2311 int ret, err;
2312
2313 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p))
2314 return 0;
2315
2316 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end);
2317 if (addr == end)
2318 return ret;
2319
2320 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2321 return ret;
2322
2323 err = uffd_wp_range(vma, addr, end - addr, true);
2324 if (err < 0)
2325 ret = err;
2326
2327 return ret;
2328}
2329
2330static const struct mm_walk_ops pagemap_scan_ops = {
2331 .test_walk = pagemap_scan_test_walk,
2332 .pmd_entry = pagemap_scan_pmd_entry,
2333 .pte_hole = pagemap_scan_pte_hole,
2334 .hugetlb_entry = pagemap_scan_hugetlb_entry,
2335};
2336
2337static int pagemap_scan_get_args(struct pm_scan_arg *arg,
2338 unsigned long uarg)
2339{
2340 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg)))
2341 return -EFAULT;
2342
2343 if (arg->size != sizeof(struct pm_scan_arg))
2344 return -EINVAL;
2345
2346 /* Validate requested features */
2347 if (arg->flags & ~PM_SCAN_FLAGS)
2348 return -EINVAL;
2349 if ((arg->category_inverted | arg->category_mask |
2350 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES)
2351 return -EINVAL;
2352
2353 arg->start = untagged_addr((unsigned long)arg->start);
2354 arg->end = untagged_addr((unsigned long)arg->end);
2355 arg->vec = untagged_addr((unsigned long)arg->vec);
2356
2357 /* Validate memory pointers */
2358 if (!IS_ALIGNED(arg->start, PAGE_SIZE))
2359 return -EINVAL;
2360 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start))
2361 return -EFAULT;
2362 if (!arg->vec && arg->vec_len)
2363 return -EINVAL;
2364 if (arg->vec && !access_ok((void __user *)(long)arg->vec,
2365 arg->vec_len * sizeof(struct page_region)))
2366 return -EFAULT;
2367
2368 /* Fixup default values */
2369 arg->end = ALIGN(arg->end, PAGE_SIZE);
2370 arg->walk_end = 0;
2371 if (!arg->max_pages)
2372 arg->max_pages = ULONG_MAX;
2373
2374 return 0;
2375}
2376
2377static int pagemap_scan_writeback_args(struct pm_scan_arg *arg,
2378 unsigned long uargl)
2379{
2380 struct pm_scan_arg __user *uarg = (void __user *)uargl;
2381
2382 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end)))
2383 return -EFAULT;
2384
2385 return 0;
2386}
2387
2388static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p)
2389{
2390 if (!p->arg.vec_len)
2391 return 0;
2392
2393 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT,
2394 p->arg.vec_len);
2395 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf),
2396 GFP_KERNEL);
2397 if (!p->vec_buf)
2398 return -ENOMEM;
2399
2400 p->vec_buf->start = p->vec_buf->end = 0;
2401 p->vec_out = (struct page_region __user *)(long)p->arg.vec;
2402
2403 return 0;
2404}
2405
2406static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p)
2407{
2408 const struct page_region *buf = p->vec_buf;
2409 long n = p->vec_buf_index;
2410
2411 if (!p->vec_buf)
2412 return 0;
2413
2414 if (buf[n].end != buf[n].start)
2415 n++;
2416
2417 if (!n)
2418 return 0;
2419
2420 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf)))
2421 return -EFAULT;
2422
2423 p->arg.vec_len -= n;
2424 p->vec_out += n;
2425
2426 p->vec_buf_index = 0;
2427 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len);
2428 p->vec_buf->start = p->vec_buf->end = 0;
2429
2430 return n;
2431}
2432
2433static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg)
2434{
2435 struct pagemap_scan_private p = {0};
2436 unsigned long walk_start;
2437 size_t n_ranges_out = 0;
2438 int ret;
2439
2440 ret = pagemap_scan_get_args(&p.arg, uarg);
2441 if (ret)
2442 return ret;
2443
2444 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask |
2445 p.arg.return_mask;
2446 ret = pagemap_scan_init_bounce_buffer(&p);
2447 if (ret)
2448 return ret;
2449
2450 for (walk_start = p.arg.start; walk_start < p.arg.end;
2451 walk_start = p.arg.walk_end) {
2452 struct mmu_notifier_range range;
2453 long n_out;
2454
2455 if (fatal_signal_pending(current)) {
2456 ret = -EINTR;
2457 break;
2458 }
2459
2460 ret = mmap_read_lock_killable(mm);
2461 if (ret)
2462 break;
2463
2464 /* Protection change for the range is going to happen. */
2465 if (p.arg.flags & PM_SCAN_WP_MATCHING) {
2466 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0,
2467 mm, walk_start, p.arg.end);
2468 mmu_notifier_invalidate_range_start(&range);
2469 }
2470
2471 ret = walk_page_range(mm, walk_start, p.arg.end,
2472 &pagemap_scan_ops, &p);
2473
2474 if (p.arg.flags & PM_SCAN_WP_MATCHING)
2475 mmu_notifier_invalidate_range_end(&range);
2476
2477 mmap_read_unlock(mm);
2478
2479 n_out = pagemap_scan_flush_buffer(&p);
2480 if (n_out < 0)
2481 ret = n_out;
2482 else
2483 n_ranges_out += n_out;
2484
2485 if (ret != -ENOSPC)
2486 break;
2487
2488 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages)
2489 break;
2490 }
2491
2492 /* ENOSPC signifies early stop (buffer full) from the walk. */
2493 if (!ret || ret == -ENOSPC)
2494 ret = n_ranges_out;
2495
2496 /* The walk_end isn't set when ret is zero */
2497 if (!p.arg.walk_end)
2498 p.arg.walk_end = p.arg.end;
2499 if (pagemap_scan_writeback_args(&p.arg, uarg))
2500 ret = -EFAULT;
2501
2502 kfree(p.vec_buf);
2503 return ret;
2504}
2505
2506static long do_pagemap_cmd(struct file *file, unsigned int cmd,
2507 unsigned long arg)
2508{
2509 struct mm_struct *mm = file->private_data;
2510
2511 switch (cmd) {
2512 case PAGEMAP_SCAN:
2513 return do_pagemap_scan(mm, arg);
2514
2515 default:
2516 return -EINVAL;
2517 }
2518}
2519
2520const struct file_operations proc_pagemap_operations = {
2521 .llseek = mem_lseek, /* borrow this */
2522 .read = pagemap_read,
2523 .open = pagemap_open,
2524 .release = pagemap_release,
2525 .unlocked_ioctl = do_pagemap_cmd,
2526 .compat_ioctl = do_pagemap_cmd,
2527};
2528#endif /* CONFIG_PROC_PAGE_MONITOR */
2529
2530#ifdef CONFIG_NUMA
2531
2532struct numa_maps {
2533 unsigned long pages;
2534 unsigned long anon;
2535 unsigned long active;
2536 unsigned long writeback;
2537 unsigned long mapcount_max;
2538 unsigned long dirty;
2539 unsigned long swapcache;
2540 unsigned long node[MAX_NUMNODES];
2541};
2542
2543struct numa_maps_private {
2544 struct proc_maps_private proc_maps;
2545 struct numa_maps md;
2546};
2547
2548static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
2549 unsigned long nr_pages)
2550{
2551 int count = page_mapcount(page);
2552
2553 md->pages += nr_pages;
2554 if (pte_dirty || PageDirty(page))
2555 md->dirty += nr_pages;
2556
2557 if (PageSwapCache(page))
2558 md->swapcache += nr_pages;
2559
2560 if (PageActive(page) || PageUnevictable(page))
2561 md->active += nr_pages;
2562
2563 if (PageWriteback(page))
2564 md->writeback += nr_pages;
2565
2566 if (PageAnon(page))
2567 md->anon += nr_pages;
2568
2569 if (count > md->mapcount_max)
2570 md->mapcount_max = count;
2571
2572 md->node[page_to_nid(page)] += nr_pages;
2573}
2574
2575static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
2576 unsigned long addr)
2577{
2578 struct page *page;
2579 int nid;
2580
2581 if (!pte_present(pte))
2582 return NULL;
2583
2584 page = vm_normal_page(vma, addr, pte);
2585 if (!page || is_zone_device_page(page))
2586 return NULL;
2587
2588 if (PageReserved(page))
2589 return NULL;
2590
2591 nid = page_to_nid(page);
2592 if (!node_isset(nid, node_states[N_MEMORY]))
2593 return NULL;
2594
2595 return page;
2596}
2597
2598#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2599static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
2600 struct vm_area_struct *vma,
2601 unsigned long addr)
2602{
2603 struct page *page;
2604 int nid;
2605
2606 if (!pmd_present(pmd))
2607 return NULL;
2608
2609 page = vm_normal_page_pmd(vma, addr, pmd);
2610 if (!page)
2611 return NULL;
2612
2613 if (PageReserved(page))
2614 return NULL;
2615
2616 nid = page_to_nid(page);
2617 if (!node_isset(nid, node_states[N_MEMORY]))
2618 return NULL;
2619
2620 return page;
2621}
2622#endif
2623
2624static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
2625 unsigned long end, struct mm_walk *walk)
2626{
2627 struct numa_maps *md = walk->private;
2628 struct vm_area_struct *vma = walk->vma;
2629 spinlock_t *ptl;
2630 pte_t *orig_pte;
2631 pte_t *pte;
2632
2633#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2634 ptl = pmd_trans_huge_lock(pmd, vma);
2635 if (ptl) {
2636 struct page *page;
2637
2638 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
2639 if (page)
2640 gather_stats(page, md, pmd_dirty(*pmd),
2641 HPAGE_PMD_SIZE/PAGE_SIZE);
2642 spin_unlock(ptl);
2643 return 0;
2644 }
2645#endif
2646 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
2647 if (!pte) {
2648 walk->action = ACTION_AGAIN;
2649 return 0;
2650 }
2651 do {
2652 pte_t ptent = ptep_get(pte);
2653 struct page *page = can_gather_numa_stats(ptent, vma, addr);
2654 if (!page)
2655 continue;
2656 gather_stats(page, md, pte_dirty(ptent), 1);
2657
2658 } while (pte++, addr += PAGE_SIZE, addr != end);
2659 pte_unmap_unlock(orig_pte, ptl);
2660 cond_resched();
2661 return 0;
2662}
2663#ifdef CONFIG_HUGETLB_PAGE
2664static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
2665 unsigned long addr, unsigned long end, struct mm_walk *walk)
2666{
2667 pte_t huge_pte = huge_ptep_get(pte);
2668 struct numa_maps *md;
2669 struct page *page;
2670
2671 if (!pte_present(huge_pte))
2672 return 0;
2673
2674 page = pte_page(huge_pte);
2675
2676 md = walk->private;
2677 gather_stats(page, md, pte_dirty(huge_pte), 1);
2678 return 0;
2679}
2680
2681#else
2682static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
2683 unsigned long addr, unsigned long end, struct mm_walk *walk)
2684{
2685 return 0;
2686}
2687#endif
2688
2689static const struct mm_walk_ops show_numa_ops = {
2690 .hugetlb_entry = gather_hugetlb_stats,
2691 .pmd_entry = gather_pte_stats,
2692 .walk_lock = PGWALK_RDLOCK,
2693};
2694
2695/*
2696 * Display pages allocated per node and memory policy via /proc.
2697 */
2698static int show_numa_map(struct seq_file *m, void *v)
2699{
2700 struct numa_maps_private *numa_priv = m->private;
2701 struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
2702 struct vm_area_struct *vma = v;
2703 struct numa_maps *md = &numa_priv->md;
2704 struct file *file = vma->vm_file;
2705 struct mm_struct *mm = vma->vm_mm;
2706 char buffer[64];
2707 struct mempolicy *pol;
2708 pgoff_t ilx;
2709 int nid;
2710
2711 if (!mm)
2712 return 0;
2713
2714 /* Ensure we start with an empty set of numa_maps statistics. */
2715 memset(md, 0, sizeof(*md));
2716
2717 pol = __get_vma_policy(vma, vma->vm_start, &ilx);
2718 if (pol) {
2719 mpol_to_str(buffer, sizeof(buffer), pol);
2720 mpol_cond_put(pol);
2721 } else {
2722 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
2723 }
2724
2725 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
2726
2727 if (file) {
2728 seq_puts(m, " file=");
2729 seq_path(m, file_user_path(file), "\n\t= ");
2730 } else if (vma_is_initial_heap(vma)) {
2731 seq_puts(m, " heap");
2732 } else if (vma_is_initial_stack(vma)) {
2733 seq_puts(m, " stack");
2734 }
2735
2736 if (is_vm_hugetlb_page(vma))
2737 seq_puts(m, " huge");
2738
2739 /* mmap_lock is held by m_start */
2740 walk_page_vma(vma, &show_numa_ops, md);
2741
2742 if (!md->pages)
2743 goto out;
2744
2745 if (md->anon)
2746 seq_printf(m, " anon=%lu", md->anon);
2747
2748 if (md->dirty)
2749 seq_printf(m, " dirty=%lu", md->dirty);
2750
2751 if (md->pages != md->anon && md->pages != md->dirty)
2752 seq_printf(m, " mapped=%lu", md->pages);
2753
2754 if (md->mapcount_max > 1)
2755 seq_printf(m, " mapmax=%lu", md->mapcount_max);
2756
2757 if (md->swapcache)
2758 seq_printf(m, " swapcache=%lu", md->swapcache);
2759
2760 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2761 seq_printf(m, " active=%lu", md->active);
2762
2763 if (md->writeback)
2764 seq_printf(m, " writeback=%lu", md->writeback);
2765
2766 for_each_node_state(nid, N_MEMORY)
2767 if (md->node[nid])
2768 seq_printf(m, " N%d=%lu", nid, md->node[nid]);
2769
2770 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
2771out:
2772 seq_putc(m, '\n');
2773 return 0;
2774}
2775
2776static const struct seq_operations proc_pid_numa_maps_op = {
2777 .start = m_start,
2778 .next = m_next,
2779 .stop = m_stop,
2780 .show = show_numa_map,
2781};
2782
2783static int pid_numa_maps_open(struct inode *inode, struct file *file)
2784{
2785 return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2786 sizeof(struct numa_maps_private));
2787}
2788
2789const struct file_operations proc_pid_numa_maps_operations = {
2790 .open = pid_numa_maps_open,
2791 .read = seq_read,
2792 .llseek = seq_lseek,
2793 .release = proc_map_release,
2794};
2795
2796#endif /* CONFIG_NUMA */