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fs/proc: show correct device and inode numbers in /proc/pid/maps
[thirdparty/linux.git] / fs / proc / task_mmu.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
a520110e 2#include <linux/pagewalk.h>
17fca131 3#include <linux/mm_inline.h>
1da177e4 4#include <linux/hugetlb.h>
22e057c5 5#include <linux/huge_mm.h>
1da177e4 6#include <linux/mount.h>
8b479335 7#include <linux/ksm.h>
1da177e4 8#include <linux/seq_file.h>
e070ad49 9#include <linux/highmem.h>
5096add8 10#include <linux/ptrace.h>
5a0e3ad6 11#include <linux/slab.h>
6e21c8f1
CL		 12#include <linux/pagemap.h>
13#include <linux/mempolicy.h>
22e057c5 14#include <linux/rmap.h>
85863e47 15#include <linux/swap.h>
6e84f315 16#include <linux/sched/mm.h>
85863e47 17#include <linux/swapops.h>
0f8975ec 18#include <linux/mmu_notifier.h>
33c3fc71 19#include <linux/page_idle.h>
6a15a370 20#include <linux/shmem_fs.h>
b3a81d08 21#include <linux/uaccess.h>
27cca866 22#include <linux/pkeys.h>
52526ca7
MUA		 23#include <linux/minmax.h>
24#include <linux/overflow.h>
e070ad49 25
1da177e4 26#include <asm/elf.h>
b3a81d08 27#include <asm/tlb.h>
e070ad49 28#include <asm/tlbflush.h>
1da177e4
LT		 29#include "internal.h"
30
d1be35cb
AV		 31#define SEQ_PUT_DEC(str, val) \
32 seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
df5f8314 33void task_mem(struct seq_file *m, struct mm_struct *mm)
1da177e4 34{
af5b0f6a 35 unsigned long text, lib, swap, anon, file, shmem;
365e9c87
HD		 36 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
37
8cee852e
JM		 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
365e9c87
HD		 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;
8cee852e 52 hiwater_rss = total_rss = anon + file + shmem;
365e9c87
HD		 53 if (hiwater_rss < mm->hiwater_rss)
54 hiwater_rss = mm->hiwater_rss;
1da177e4 55
8526d84f
KK		 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
b084d435 61 swap = get_mm_counter(mm, MM_SWAPENTS);
d1be35cb
AV		 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);
70f8a3ca 65 SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
d1be35cb
AV		 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");
5d317b2b 81 hugetlb_report_usage(m, mm);
1da177e4 82}
d1be35cb 83#undef SEQ_PUT_DEC
1da177e4
LT		 84
85unsigned long task_vsize(struct mm_struct *mm)
86{
87 return PAGE_SIZE * mm->total_vm;
88}
89
a2ade7b6
AD		 90unsigned long task_statm(struct mm_struct *mm,
91 unsigned long *shared, unsigned long *text,
92 unsigned long *data, unsigned long *resident)
1da177e4 93{
eca56ff9
JM		 94 *shared = get_mm_counter(mm, MM_FILEPAGES) +
95 get_mm_counter(mm, MM_SHMEMPAGES);
1da177e4
LT		 96 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
97 >> PAGE_SHIFT;
84638335 98 *data = mm->data_vm + mm->stack_vm;
d559db08 99 *resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
1da177e4
LT		 100 return mm->total_vm;
101}
102
9e781440
KH		 103#ifdef CONFIG_NUMA
104/*
498f2371 105 * Save get_task_policy() for show_numa_map().
9e781440
KH		 106 */
107static void hold_task_mempolicy(struct proc_maps_private *priv)
108{
109 struct task_struct *task = priv->task;
110
111 task_lock(task);
498f2371 112 priv->task_mempolicy = get_task_policy(task);
9e781440
KH		 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
c4c84f06
MWO		 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
0c255321 144static void *m_start(struct seq_file *m, loff_t *ppos)
e070ad49 145{
a6198797 146 struct proc_maps_private *priv = m->private;
4781f2c3 147 unsigned long last_addr = *ppos;
a6198797 148 struct mm_struct *mm;
a6198797 149
c2e88d22 150 /* See m_next(). Zero at the start or after lseek. */
b8c20a9b
ON		 151 if (last_addr == -1UL)
152 return NULL;
153
2c03376d 154 priv->task = get_proc_task(priv->inode);
a6198797 155 if (!priv->task)
ec6fd8a4 156 return ERR_PTR(-ESRCH);
a6198797 157
29a40ace 158 mm = priv->mm;
d07ded61
MWO		 159 if (!mm || !mmget_not_zero(mm)) {
160 put_task_struct(priv->task);
161 priv->task = NULL;
29a40ace 162 return NULL;
d07ded61 163 }
a6198797 164
d8ed45c5 165 if (mmap_read_lock_killable(mm)) {
8a713e7d 166 mmput(mm);
d07ded61
MWO		 167 put_task_struct(priv->task);
168 priv->task = NULL;
8a713e7d
KK		 169 return ERR_PTR(-EINTR);
170 }
171
c4c84f06 172 vma_iter_init(&priv->iter, mm, last_addr);
9e781440 173 hold_task_mempolicy(priv);
c4c84f06
MWO		 174 if (last_addr == -2UL)
175 return get_gate_vma(mm);
59b4bf12 176
c4c84f06 177 return proc_get_vma(priv, ppos);
a6198797
MM		 178}
179
4781f2c3 180static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
a6198797 181{
c4c84f06
MWO		 182 if (*ppos == -2UL) {
183 *ppos = -1UL;
184 return NULL;
185 }
186 return proc_get_vma(m->private, ppos);
a6198797
MM		 187}
188
189static void m_stop(struct seq_file *m, void *v)
190{
191 struct proc_maps_private *priv = m->private;
d07ded61 192 struct mm_struct *mm = priv->mm;
a6198797 193
d07ded61
MWO		 194 if (!priv->task)
195 return;
196
197 release_task_mempolicy(priv);
d8ed45c5 198 mmap_read_unlock(mm);
d07ded61
MWO		 199 mmput(mm);
200 put_task_struct(priv->task);
201 priv->task = NULL;
a6198797
MM		 202}
203
4db7d0ee
ON		 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
2c03376d 212 priv->inode = inode;
29a40ace
ON		 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
4db7d0ee
ON		 221 return 0;
222}
223
29a40ace
ON		 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
a6198797 235static int do_maps_open(struct inode *inode, struct file *file,
03a44825 236 const struct seq_operations *ops)
a6198797 237{
4db7d0ee
ON		 238 return proc_maps_open(inode, file, ops,
239 sizeof(struct proc_maps_private));
a6198797 240}
e070ad49 241
493b0e9d
DC		 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);
0e3dc019
AV		 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, ' ');
493b0e9d
DC		 260}
261
b7643757 262static void
871305bb 263show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
1da177e4 264{
d09e8ca6 265 struct anon_vma_name *anon_name = NULL;
e070ad49
ML		 266 struct mm_struct *mm = vma->vm_mm;
267 struct file *file = vma->vm_file;
ca16d140 268 vm_flags_t flags = vma->vm_flags;
1da177e4 269 unsigned long ino = 0;
6260a4b0 270 unsigned long long pgoff = 0;
a09a79f6 271 unsigned long start, end;
1da177e4 272 dev_t dev = 0;
b7643757 273 const char *name = NULL;
1da177e4
LT		 274
275 if (file) {
3efdc78f
AV		 276 const struct inode *inode = file_user_inode(vma->vm_file);
277
1da177e4
LT		 278 dev = inode->i_sb->s_dev;
279 ino = inode->i_ino;
6260a4b0 280 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
1da177e4
LT		 281 }
282
d7824370 283 start = vma->vm_start;
a09a79f6 284 end = vma->vm_end;
493b0e9d 285 show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
d09e8ca6
PT		 286 if (mm)
287 anon_name = anon_vma_name(vma);
1da177e4
LT		 288
289 /*
290 * Print the dentry name for named mappings, and a
291 * special [heap] marker for the heap:
292 */
e070ad49 293 if (file) {
652586df 294 seq_pad(m, ' ');
d09e8ca6
PT		 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
08582d67 302 seq_path(m, file_user_path(file), "\n");
b7643757
SP		 303 goto done;
304 }
305
78d683e8
AL		 306 if (vma->vm_ops && vma->vm_ops->name) {
307 name = vma->vm_ops->name(vma);
308 if (name)
309 goto done;
310 }
311
b7643757
SP		 312 name = arch_vma_name(vma);
313 if (!name) {
b7643757
SP		 314 if (!mm) {
315 name = "[vdso]";
316 goto done;
317 }
318
11250fd1 319 if (vma_is_initial_heap(vma)) {
b7643757
SP		 320 name = "[heap]";
321 goto done;
322 }
323
11250fd1 324 if (vma_is_initial_stack(vma)) {
65376df5 325 name = "[stack]";
9a10064f
CC		 326 goto done;
327 }
328
9a10064f
CC		 329 if (anon_name) {
330 seq_pad(m, ' ');
5c26f6ac 331 seq_printf(m, "[anon:%s]", anon_name->name);
9a10064f 332 }
b7643757
SP		 333 }
334
335done:
336 if (name) {
652586df 337 seq_pad(m, ' ');
b7643757 338 seq_puts(m, name);
1da177e4
LT		 339 }
340 seq_putc(m, '\n');
7c88db0c
JK		 341}
342
871305bb 343static int show_map(struct seq_file *m, void *v)
7c88db0c 344{
871305bb 345 show_map_vma(m, v);
1da177e4
LT		 346 return 0;
347}
348
03a44825 349static const struct seq_operations proc_pid_maps_op = {
a6198797
MM		 350 .start = m_start,
351 .next = m_next,
352 .stop = m_stop,
871305bb 353 .show = show_map
a6198797
MM		 354};
355
b7643757 356static int pid_maps_open(struct inode *inode, struct file *file)
a6198797
MM		 357{
358 return do_maps_open(inode, file, &proc_pid_maps_op);
359}
360
b7643757
SP		 361const struct file_operations proc_pid_maps_operations = {
362 .open = pid_maps_open,
363 .read = seq_read,
364 .llseek = seq_lseek,
29a40ace 365 .release = proc_map_release,
b7643757
SP		 366};
367
a6198797
MM		 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
1e883281 387#ifdef CONFIG_PROC_PAGE_MONITOR
214e471f 388struct mem_size_stats {
a6198797
MM		 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;
b40d4f84 395 unsigned long anonymous;
cf8496ea 396 unsigned long lazyfree;
4031a219 397 unsigned long anonymous_thp;
65c45377 398 unsigned long shmem_thp;
60fbf0ab 399 unsigned long file_thp;
214e471f 400 unsigned long swap;
25ee01a2
NH		 401 unsigned long shared_hugetlb;
402 unsigned long private_hugetlb;
8b479335 403 unsigned long ksm;
a6198797 404 u64 pss;
ee2ad71b
LS		 405 u64 pss_anon;
406 u64 pss_file;
407 u64 pss_shmem;
30934843 408 u64 pss_dirty;
493b0e9d 409 u64 pss_locked;
8334b962 410 u64 swap_pss;
a6198797
MM		 411};
412
ee2ad71b
LS		 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)) {
30934843 430 mss->pss_dirty += pss;
ee2ad71b
LS		 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
c164e038 443static void smaps_account(struct mem_size_stats *mss, struct page *page,
24d7275c
YS		 444 bool compound, bool young, bool dirty, bool locked,
445 bool migration)
c164e038 446{
d8c6546b 447 int i, nr = compound ? compound_nr(page) : 1;
afd9883f 448 unsigned long size = nr * PAGE_SIZE;
c164e038 449
ee2ad71b
LS		 450 /*
451 * First accumulate quantities that depend only on |size| and the type
452 * of the compound page.
453 */
cf8496ea 454 if (PageAnon(page)) {
c164e038 455 mss->anonymous += size;
cf8496ea
SL		 456 if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
457 mss->lazyfree += size;
458 }
c164e038 459
8b479335
SR		 460 if (PageKsm(page))
461 mss->ksm += size;
462
c164e038
KS		 463 mss->resident += size;
464 /* Accumulate the size in pages that have been accessed. */
33c3fc71 465 if (young || page_is_young(page) || PageReferenced(page))
c164e038 466 mss->referenced += size;
c164e038 467
afd9883f 468 /*
ee2ad71b
LS		 469 * Then accumulate quantities that may depend on sharing, or that may
470 * differ page-by-page.
471 *
afd9883f
KS		 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().
24d7275c
YS		 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.
afd9883f 482 */
24d7275c 483 if ((page_count(page) == 1) || migration) {
ee2ad71b
LS		 484 smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
485 locked, true);
afd9883f
KS		 486 return;
487 }
afd9883f
KS		 488 for (i = 0; i < nr; i++, page++) {
489 int mapcount = page_mapcount(page);
ee2ad71b
LS		 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);
c164e038
KS		 495 }
496}
ae11c4d9 497
c261e7d9 498#ifdef CONFIG_SHMEM
c261e7d9 499static int smaps_pte_hole(unsigned long addr, unsigned long end,
b7a16c7a 500 __always_unused int depth, struct mm_walk *walk)
c261e7d9
VB		 501{
502 struct mem_size_stats *mss = walk->private;
10c848c8 503 struct vm_area_struct *vma = walk->vma;
c261e7d9 504
10c848c8
PX		 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));
c261e7d9
VB		 508
509 return 0;
510}
7b86ac33
CH		 511#else
512#define smaps_pte_hole NULL
513#endif /* CONFIG_SHMEM */
c261e7d9 514
23010032
PX		 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
c164e038
KS		 525static void smaps_pte_entry(pte_t *pte, unsigned long addr,
526 struct mm_walk *walk)
ae11c4d9
DH		 527{
528 struct mem_size_stats *mss = walk->private;
14eb6fdd 529 struct vm_area_struct *vma = walk->vma;
27dd768e 530 bool locked = !!(vma->vm_flags & VM_LOCKED);
b1d4d9e0 531 struct page *page = NULL;
efd41493 532 bool migration = false, young = false, dirty = false;
c33c7948 533 pte_t ptent = ptep_get(pte);
ae11c4d9 534
c33c7948
RR		 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);
ae11c4d9 541
8334b962
MK		 542 if (!non_swap_entry(swpent)) {
543 int mapcount;
544
c164e038 545 mss->swap += PAGE_SIZE;
8334b962
MK		 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 }
24d7275c
YS		 555 } else if (is_pfn_swap_entry(swpent)) {
556 if (is_migration_entry(swpent))
557 migration = true;
af5cdaf8 558 page = pfn_swap_entry_to_page(swpent);
24d7275c 559 }
23010032
PX		 560 } else {
561 smaps_pte_hole_lookup(addr, walk);
48131e03 562 return;
b1d4d9e0 563 }
ae11c4d9 564
ae11c4d9
DH		 565 if (!page)
566 return;
afd9883f 567
efd41493 568 smaps_account(mss, page, false, young, dirty, locked, migration);
ae11c4d9
DH		 569}
570
c164e038
KS		 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;
14eb6fdd 576 struct vm_area_struct *vma = walk->vma;
27dd768e 577 bool locked = !!(vma->vm_flags & VM_LOCKED);
c94b6923 578 struct page *page = NULL;
24d7275c 579 bool migration = false;
c94b6923
HY		 580
581 if (pmd_present(*pmd)) {
8b9c1cc0 582 page = vm_normal_page_pmd(vma, addr, *pmd);
c94b6923
HY		 583 } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
584 swp_entry_t entry = pmd_to_swp_entry(*pmd);
c164e038 585
24d7275c
YS		 586 if (is_migration_entry(entry)) {
587 migration = true;
af5cdaf8 588 page = pfn_swap_entry_to_page(entry);
24d7275c 589 }
c94b6923 590 }
c164e038
KS		 591 if (IS_ERR_OR_NULL(page))
592 return;
65c45377
KS		 593 if (PageAnon(page))
594 mss->anonymous_thp += HPAGE_PMD_SIZE;
595 else if (PageSwapBacked(page))
596 mss->shmem_thp += HPAGE_PMD_SIZE;
ca120cf6
DW		 597 else if (is_zone_device_page(page))
598 /* pass */;
65c45377 599 else
60fbf0ab 600 mss->file_thp += HPAGE_PMD_SIZE;
24d7275c
YS		 601
602 smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
603 locked, migration);
c164e038
KS		 604}
605#else
606static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
607 struct mm_walk *walk)
608{
609}
610#endif
611
b3ae5acb 612static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 613 struct mm_walk *walk)
e070ad49 614{
14eb6fdd 615 struct vm_area_struct *vma = walk->vma;
ae11c4d9 616 pte_t *pte;
705e87c0 617 spinlock_t *ptl;
e070ad49 618
b6ec57f4
KS		 619 ptl = pmd_trans_huge_lock(pmd, vma);
620 if (ptl) {
c94b6923 621 smaps_pmd_entry(pmd, addr, walk);
bf929152 622 spin_unlock(ptl);
14038302 623 goto out;
22e057c5 624 }
1a5a9906 625
705e87c0 626 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
7780d040
HD		 627 if (!pte) {
628 walk->action = ACTION_AGAIN;
629 return 0;
630 }
ae11c4d9 631 for (; addr != end; pte++, addr += PAGE_SIZE)
c164e038 632 smaps_pte_entry(pte, addr, walk);
705e87c0 633 pte_unmap_unlock(pte - 1, ptl);
14038302 634out:
705e87c0 635 cond_resched();
b3ae5acb 636 return 0;
e070ad49
ML		 637}
638
834f82e2
CG		 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",
834f82e2
CG		 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",
8614d6c5 666 [ilog2(VM_LOCKONFAULT)] = "lf",
834f82e2
CG		 667 [ilog2(VM_ACCOUNT)] = "ac",
668 [ilog2(VM_NORESERVE)] = "nr",
669 [ilog2(VM_HUGETLB)] = "ht",
b6fb293f 670 [ilog2(VM_SYNC)] = "sf",
834f82e2 671 [ilog2(VM_ARCH_1)] = "ar",
d2cd9ede 672 [ilog2(VM_WIPEONFORK)] = "wf",
834f82e2 673 [ilog2(VM_DONTDUMP)] = "dd",
424037b7
DK		 674#ifdef CONFIG_ARM64_BTI
675 [ilog2(VM_ARM64_BTI)] = "bt",
676#endif
ec8e41ae
NH		 677#ifdef CONFIG_MEM_SOFT_DIRTY
678 [ilog2(VM_SOFTDIRTY)] = "sd",
679#endif
834f82e2
CG		 680 [ilog2(VM_MIXEDMAP)] = "mm",
681 [ilog2(VM_HUGEPAGE)] = "hg",
682 [ilog2(VM_NOHUGEPAGE)] = "nh",
683 [ilog2(VM_MERGEABLE)] = "mg",
16ba6f81
AA		 684 [ilog2(VM_UFFD_MISSING)]= "um",
685 [ilog2(VM_UFFD_WP)] = "uw",
9f341931
CM		 686#ifdef CONFIG_ARM64_MTE
687 [ilog2(VM_MTE)] = "mt",
688 [ilog2(VM_MTE_ALLOWED)] = "",
689#endif
5212213a 690#ifdef CONFIG_ARCH_HAS_PKEYS
c1192f84
DH		 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)] = "",
2c9e0a6f
RP		 696#if VM_PKEY_BIT4
697 [ilog2(VM_PKEY_BIT4)] = "",
c1192f84 698#endif
5212213a 699#endif /* CONFIG_ARCH_HAS_PKEYS */
7677f7fd
AR		 700#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
701 [ilog2(VM_UFFD_MINOR)] = "ui",
702#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
54007f81
YY		 703#ifdef CONFIG_X86_USER_SHADOW_STACK
704 [ilog2(VM_SHADOW_STACK)] = "ss",
705#endif
834f82e2
CG		 706 };
707 size_t i;
708
709 seq_puts(m, "VmFlags: ");
710 for (i = 0; i < BITS_PER_LONG; i++) {
c1192f84
DH		 711 if (!mnemonics[i][0])
712 continue;
834f82e2 713 if (vma->vm_flags & (1UL << i)) {
f6640663
AV		 714 seq_putc(m, mnemonics[i][0]);
715 seq_putc(m, mnemonics[i][1]);
716 seq_putc(m, ' ');
834f82e2
CG		 717 }
718 }
719 seq_putc(m, '\n');
720}
721
25ee01a2
NH		 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;
c33c7948 730 pte_t ptent = ptep_get(pte);
25ee01a2 731
c33c7948
RR		 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);
25ee01a2 736
af5cdaf8
AP		 737 if (is_pfn_swap_entry(swpent))
738 page = pfn_swap_entry_to_page(swpent);
25ee01a2
NH		 739 }
740 if (page) {
3489dbb6 741 if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
25ee01a2
NH		 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}
7b86ac33
CH		 748#else
749#define smaps_hugetlb_range NULL
25ee01a2
NH		 750#endif /* HUGETLB_PAGE */
751
7b86ac33
CH		 752static const struct mm_walk_ops smaps_walk_ops = {
753 .pmd_entry = smaps_pte_range,
754 .hugetlb_entry = smaps_hugetlb_range,
49b06385 755 .walk_lock = PGWALK_RDLOCK,
7b86ac33
CH		 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,
49b06385 762 .walk_lock = PGWALK_RDLOCK,
7b86ac33
CH		 763};
764
03b4b114
CC		 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 */
8e68d689 771static void smap_gather_stats(struct vm_area_struct *vma,
03b4b114 772 struct mem_size_stats *mss, unsigned long start)
e070ad49 773{
03b4b114
CC		 774 const struct mm_walk_ops *ops = &smaps_walk_ops;
775
776 /* Invalid start */
777 if (start >= vma->vm_end)
778 return;
779
c261e7d9 780 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
6a15a370
VB		 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
03b4b114
CC		 793 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
794 !(vma->vm_flags & VM_WRITE))) {
fa76da46 795 mss->swap += shmem_swapped;
6a15a370 796 } else {
03b4b114 797 ops = &smaps_shmem_walk_ops;
6a15a370 798 }
c261e7d9 799 }
b4aca547 800
c1e8d7c6 801 /* mmap_lock is held in m_start */
03b4b114
CC		 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);
8e68d689
VB		 806}
807
808#define SEQ_PUT_DEC(str, val) \
809 seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
f1547959
VB		 810
811/* Show the contents common for smaps and smaps_rollup */
ee2ad71b
LS		 812static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
813 bool rollup_mode)
f1547959
VB		 814{
815 SEQ_PUT_DEC("Rss: ", mss->resident);
816 SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
30934843 817 SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT);
ee2ad71b
LS		 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 }
f1547959
VB		 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);
8b479335 836 SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm);
f1547959
VB		 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);
471e78cc 840 SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp);
f1547959
VB		 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
8e68d689
VB		 852static int show_smap(struct seq_file *m, void *v)
853{
8e68d689 854 struct vm_area_struct *vma = v;
860a2e7f 855 struct mem_size_stats mss = {};
258f669e 856
03b4b114 857 smap_gather_stats(vma, &mss, 0);
258f669e
VB		 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
ee2ad71b 866 __show_smap(m, &mss, false);
258f669e 867
daa60ae6 868 seq_printf(m, "THPeligible: %8u\n",
a7f4e6e4 869 hugepage_vma_check(vma, vma->vm_flags, true, false, true));
7635d9cb 870
258f669e
VB		 871 if (arch_pkeys_enabled())
872 seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
873 show_smap_vma_flags(m, vma);
874
258f669e
VB		 875 return 0;
876}
877
878static int show_smaps_rollup(struct seq_file *m, void *v)
879{
880 struct proc_maps_private *priv = m->private;
860a2e7f 881 struct mem_size_stats mss = {};
c4c84f06 882 struct mm_struct *mm = priv->mm;
258f669e 883 struct vm_area_struct *vma;
c4c84f06 884 unsigned long vma_start = 0, last_vma_end = 0;
8e68d689 885 int ret = 0;
250cb40f 886 VMA_ITERATOR(vmi, mm, 0);
8e68d689 887
258f669e
VB		 888 priv->task = get_proc_task(priv->inode);
889 if (!priv->task)
890 return -ESRCH;
493b0e9d 891
258f669e
VB		 892 if (!mm || !mmget_not_zero(mm)) {
893 ret = -ESRCH;
894 goto out_put_task;
493b0e9d 895 }
4752c369 896
d8ed45c5 897 ret = mmap_read_lock_killable(mm);
a26a9781
KK		 898 if (ret)
899 goto out_put_mm;
900
258f669e 901 hold_task_mempolicy(priv);
250cb40f 902 vma = vma_next(&vmi);
f1547959 903
c4c84f06
MWO		 904 if (unlikely(!vma))
905 goto empty_set;
906
907 vma_start = vma->vm_start;
908 do {
03b4b114 909 smap_gather_stats(vma, &mss, 0);
258f669e 910 last_vma_end = vma->vm_end;
ff9f47f6
CC		 911
912 /*
913 * Release mmap_lock temporarily if someone wants to
914 * access it for write request.
915 */
916 if (mmap_lock_is_contended(mm)) {
250cb40f 917 vma_iter_invalidate(&vmi);
ff9f47f6
CC		 918 mmap_read_unlock(mm);
919 ret = mmap_read_lock_killable(mm);
920 if (ret) {
921 release_task_mempolicy(priv);
922 goto out_put_mm;
923 }
924
925 /*
926 * After dropping the lock, there are four cases to
927 * consider. See the following example for explanation.
928 *
929 * +------+------+-----------+
930 * | VMA1 | VMA2 | VMA3 |
931 * +------+------+-----------+
932 * | | | |
933 * 4k 8k 16k 400k
934 *
935 * Suppose we drop the lock after reading VMA2 due to
936 * contention, then we get:
937 *
938 * last_vma_end = 16k
939 *
940 * 1) VMA2 is freed, but VMA3 exists:
941 *
250cb40f 942 * vma_next(vmi) will return VMA3.
ff9f47f6
CC		 943 * In this case, just continue from VMA3.
944 *
945 * 2) VMA2 still exists:
946 *
250cb40f
LH		 947 * vma_next(vmi) will return VMA3.
948 * In this case, just continue from VMA3.
ff9f47f6
CC		 949 *
950 * 3) No more VMAs can be found:
951 *
250cb40f 952 * vma_next(vmi) will return NULL.
ff9f47f6
CC		 953 * No more things to do, just break.
954 *
955 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
956 *
250cb40f 957 * vma_next(vmi) will return VMA' whose range
ff9f47f6
CC		 958 * contains last_vma_end.
959 * Iterate VMA' from last_vma_end.
960 */
250cb40f 961 vma = vma_next(&vmi);
ff9f47f6
CC		 962 /* Case 3 above */
963 if (!vma)
964 break;
965
250cb40f 966 /* Case 1 and 2 above */
ff9f47f6
CC		 967 if (vma->vm_start >= last_vma_end)
968 continue;
969
970 /* Case 4 above */
971 if (vma->vm_end > last_vma_end)
972 smap_gather_stats(vma, &mss, last_vma_end);
973 }
250cb40f 974 } for_each_vma(vmi, vma);
258f669e 975
c4c84f06
MWO		 976empty_set:
977 show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
258f669e
VB		 978 seq_pad(m, ' ');
979 seq_puts(m, "[rollup]\n");
980
ee2ad71b 981 __show_smap(m, &mss, true);
258f669e
VB		 982
983 release_task_mempolicy(priv);
d8ed45c5 984 mmap_read_unlock(mm);
258f669e 985
a26a9781
KK		 986out_put_mm:
987 mmput(mm);
258f669e
VB		 988out_put_task:
989 put_task_struct(priv->task);
990 priv->task = NULL;
991
493b0e9d 992 return ret;
e070ad49 993}
d1be35cb 994#undef SEQ_PUT_DEC
e070ad49 995
03a44825 996static const struct seq_operations proc_pid_smaps_op = {
a6198797
MM		 997 .start = m_start,
998 .next = m_next,
999 .stop = m_stop,
871305bb 1000 .show = show_smap
a6198797
MM		 1001};
1002
b7643757 1003static int pid_smaps_open(struct inode *inode, struct file *file)
a6198797
MM		 1004{
1005 return do_maps_open(inode, file, &proc_pid_smaps_op);
1006}
1007
258f669e 1008static int smaps_rollup_open(struct inode *inode, struct file *file)
493b0e9d 1009{
258f669e 1010 int ret;
493b0e9d 1011 struct proc_maps_private *priv;
258f669e
VB		 1012
1013 priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
1014 if (!priv)
493b0e9d 1015 return -ENOMEM;
258f669e
VB		 1016
1017 ret = single_open(file, show_smaps_rollup, priv);
1018 if (ret)
1019 goto out_free;
1020
1021 priv->inode = inode;
1022 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
1023 if (IS_ERR(priv->mm)) {
1024 ret = PTR_ERR(priv->mm);
1025
1026 single_release(inode, file);
1027 goto out_free;
493b0e9d 1028 }
258f669e 1029
493b0e9d 1030 return 0;
258f669e
VB		 1031
1032out_free:
1033 kfree(priv);
1034 return ret;
1035}
1036
1037static int smaps_rollup_release(struct inode *inode, struct file *file)
1038{
1039 struct seq_file *seq = file->private_data;
1040 struct proc_maps_private *priv = seq->private;
1041
1042 if (priv->mm)
1043 mmdrop(priv->mm);
1044
1045 kfree(priv);
1046 return single_release(inode, file);
493b0e9d
DC		 1047}
1048
b7643757
SP		 1049const struct file_operations proc_pid_smaps_operations = {
1050 .open = pid_smaps_open,
1051 .read = seq_read,
1052 .llseek = seq_lseek,
29a40ace 1053 .release = proc_map_release,
b7643757
SP		 1054};
1055
493b0e9d 1056const struct file_operations proc_pid_smaps_rollup_operations = {
258f669e 1057 .open = smaps_rollup_open,
493b0e9d
DC		 1058 .read = seq_read,
1059 .llseek = seq_lseek,
258f669e 1060 .release = smaps_rollup_release,
493b0e9d
DC		 1061};
1062
040fa020
PE		 1063enum clear_refs_types {
1064 CLEAR_REFS_ALL = 1,
1065 CLEAR_REFS_ANON,
1066 CLEAR_REFS_MAPPED,
0f8975ec 1067 CLEAR_REFS_SOFT_DIRTY,
695f0559 1068 CLEAR_REFS_MM_HIWATER_RSS,
040fa020
PE		 1069 CLEAR_REFS_LAST,
1070};
1071
af9de7eb 1072struct clear_refs_private {
0f8975ec 1073 enum clear_refs_types type;
af9de7eb
PE		 1074};
1075
7d5b3bfa 1076#ifdef CONFIG_MEM_SOFT_DIRTY
9348b73c 1077
9348b73c
LT		 1078static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
1079{
1080 struct page *page;
1081
1082 if (!pte_write(pte))
1083 return false;
1084 if (!is_cow_mapping(vma->vm_flags))
1085 return false;
a458b76a 1086 if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
9348b73c
LT		 1087 return false;
1088 page = vm_normal_page(vma, addr, pte);
1089 if (!page)
1090 return false;
1091 return page_maybe_dma_pinned(page);
1092}
1093
0f8975ec
PE		 1094static inline void clear_soft_dirty(struct vm_area_struct *vma,
1095 unsigned long addr, pte_t *pte)
1096{
0f8975ec
PE		 1097 /*
1098 * The soft-dirty tracker uses #PF-s to catch writes
1099 * to pages, so write-protect the pte as well. See the
1ad1335d 1100 * Documentation/admin-guide/mm/soft-dirty.rst for full description
0f8975ec
PE		 1101 * of how soft-dirty works.
1102 */
c33c7948 1103 pte_t ptent = ptep_get(pte);
179ef71c
CG		 1104
1105 if (pte_present(ptent)) {
04a86453
AK		 1106 pte_t old_pte;
1107
9348b73c
LT		 1108 if (pte_is_pinned(vma, addr, ptent))
1109 return;
04a86453
AK		 1110 old_pte = ptep_modify_prot_start(vma, addr, pte);
1111 ptent = pte_wrprotect(old_pte);
a7b76174 1112 ptent = pte_clear_soft_dirty(ptent);
04a86453 1113 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
179ef71c
CG		 1114 } else if (is_swap_pte(ptent)) {
1115 ptent = pte_swp_clear_soft_dirty(ptent);
326c2597 1116 set_pte_at(vma->vm_mm, addr, pte, ptent);
179ef71c 1117 }
0f8975ec 1118}
5d3875a0
LD		 1119#else
1120static inline void clear_soft_dirty(struct vm_area_struct *vma,
1121 unsigned long addr, pte_t *pte)
1122{
1123}
1124#endif
0f8975ec 1125
5d3875a0 1126#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
7d5b3bfa
KS		 1127static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1128 unsigned long addr, pmd_t *pmdp)
1129{
a3cf988f 1130 pmd_t old, pmd = *pmdp;
5b7abeae 1131
ab6e3d09
NH		 1132 if (pmd_present(pmd)) {
1133 /* See comment in change_huge_pmd() */
a3cf988f
KS		 1134 old = pmdp_invalidate(vma, addr, pmdp);
1135 if (pmd_dirty(old))
ab6e3d09 1136 pmd = pmd_mkdirty(pmd);
a3cf988f 1137 if (pmd_young(old))
ab6e3d09
NH		 1138 pmd = pmd_mkyoung(pmd);
1139
1140 pmd = pmd_wrprotect(pmd);
1141 pmd = pmd_clear_soft_dirty(pmd);
1142
1143 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1144 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1145 pmd = pmd_swp_clear_soft_dirty(pmd);
1146 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1147 }
7d5b3bfa 1148}
7d5b3bfa 1149#else
7d5b3bfa
KS		 1150static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
1151 unsigned long addr, pmd_t *pmdp)
1152{
1153}
1154#endif
1155
a6198797 1156static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
2165009b 1157 unsigned long end, struct mm_walk *walk)
a6198797 1158{
af9de7eb 1159 struct clear_refs_private *cp = walk->private;
5c64f52a 1160 struct vm_area_struct *vma = walk->vma;
a6198797
MM		 1161 pte_t *pte, ptent;
1162 spinlock_t *ptl;
1163 struct page *page;
1164
b6ec57f4
KS		 1165 ptl = pmd_trans_huge_lock(pmd, vma);
1166 if (ptl) {
7d5b3bfa
KS		 1167 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1168 clear_soft_dirty_pmd(vma, addr, pmd);
1169 goto out;
1170 }
1171
84c3fc4e
ZY		 1172 if (!pmd_present(*pmd))
1173 goto out;
1174
7d5b3bfa
KS		 1175 page = pmd_page(*pmd);
1176
1177 /* Clear accessed and referenced bits. */
1178 pmdp_test_and_clear_young(vma, addr, pmd);
33c3fc71 1179 test_and_clear_page_young(page);
7d5b3bfa
KS		 1180 ClearPageReferenced(page);
1181out:
1182 spin_unlock(ptl);
1183 return 0;
1184 }
1185
a6198797 1186 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
7780d040
HD		 1187 if (!pte) {
1188 walk->action = ACTION_AGAIN;
1189 return 0;
1190 }
a6198797 1191 for (; addr != end; pte++, addr += PAGE_SIZE) {
c33c7948 1192 ptent = ptep_get(pte);
a6198797 1193
0f8975ec
PE		 1194 if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
1195 clear_soft_dirty(vma, addr, pte);
1196 continue;
1197 }
1198
179ef71c
CG		 1199 if (!pte_present(ptent))
1200 continue;
1201
a6198797
MM		 1202 page = vm_normal_page(vma, addr, ptent);
1203 if (!page)
1204 continue;
1205
1206 /* Clear accessed and referenced bits. */
1207 ptep_test_and_clear_young(vma, addr, pte);
33c3fc71 1208 test_and_clear_page_young(page);
a6198797
MM		 1209 ClearPageReferenced(page);
1210 }
1211 pte_unmap_unlock(pte - 1, ptl);
1212 cond_resched();
1213 return 0;
1214}
1215
5c64f52a
NH		 1216static int clear_refs_test_walk(unsigned long start, unsigned long end,
1217 struct mm_walk *walk)
1218{
1219 struct clear_refs_private *cp = walk->private;
1220 struct vm_area_struct *vma = walk->vma;
1221
48684a65
NH		 1222 if (vma->vm_flags & VM_PFNMAP)
1223 return 1;
1224
5c64f52a
NH		 1225 /*
1226 * Writing 1 to /proc/pid/clear_refs affects all pages.
1227 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
1228 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
1229 * Writing 4 to /proc/pid/clear_refs affects all pages.
1230 */
1231 if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
1232 return 1;
1233 if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
1234 return 1;
1235 return 0;
1236}
1237
7b86ac33
CH		 1238static const struct mm_walk_ops clear_refs_walk_ops = {
1239 .pmd_entry = clear_refs_pte_range,
1240 .test_walk = clear_refs_test_walk,
49b06385 1241 .walk_lock = PGWALK_WRLOCK,
7b86ac33
CH		 1242};
1243
f248dcb3
MM		 1244static ssize_t clear_refs_write(struct file *file, const char __user *buf,
1245 size_t count, loff_t *ppos)
b813e931 1246{
f248dcb3 1247 struct task_struct *task;
860a2e7f 1248 char buffer[PROC_NUMBUF] = {};
f248dcb3 1249 struct mm_struct *mm;
b813e931 1250 struct vm_area_struct *vma;
040fa020
PE		 1251 enum clear_refs_types type;
1252 int itype;
0a8cb8e3 1253 int rv;
b813e931 1254
f248dcb3
MM		 1255 if (count > sizeof(buffer) - 1)
1256 count = sizeof(buffer) - 1;
1257 if (copy_from_user(buffer, buf, count))
1258 return -EFAULT;
040fa020 1259 rv = kstrtoint(strstrip(buffer), 10, &itype);
0a8cb8e3
AD		 1260 if (rv < 0)
1261 return rv;
040fa020
PE		 1262 type = (enum clear_refs_types)itype;
1263 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
f248dcb3 1264 return -EINVAL;
541c237c 1265
496ad9aa 1266 task = get_proc_task(file_inode(file));
f248dcb3
MM		 1267 if (!task)
1268 return -ESRCH;
1269 mm = get_task_mm(task);
1270 if (mm) {
250cb40f 1271 VMA_ITERATOR(vmi, mm, 0);
ac46d4f3 1272 struct mmu_notifier_range range;
af9de7eb 1273 struct clear_refs_private cp = {
0f8975ec 1274 .type = type,
af9de7eb 1275 };
695f0559 1276
29a951df
LT		 1277 if (mmap_write_lock_killable(mm)) {
1278 count = -EINTR;
1279 goto out_mm;
1280 }
695f0559
PC		 1281 if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1282 /*
1283 * Writing 5 to /proc/pid/clear_refs resets the peak
1284 * resident set size to this mm's current rss value.
1285 */
695f0559 1286 reset_mm_hiwater_rss(mm);
29a951df 1287 goto out_unlock;
695f0559
PC		 1288 }
1289
64e45507 1290 if (type == CLEAR_REFS_SOFT_DIRTY) {
250cb40f 1291 for_each_vma(vmi, vma) {
64e45507
PF		 1292 if (!(vma->vm_flags & VM_SOFTDIRTY))
1293 continue;
1c71222e 1294 vm_flags_clear(vma, VM_SOFTDIRTY);
29a951df 1295 vma_set_page_prot(vma);
64e45507 1296 }
ac46d4f3 1297
912efa17 1298 inc_tlb_flush_pending(mm);
7269f999 1299 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
7d4a8be0 1300 0, mm, 0, -1UL);
ac46d4f3 1301 mmu_notifier_invalidate_range_start(&range);
64e45507 1302 }
c4c84f06 1303 walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp);
912efa17 1304 if (type == CLEAR_REFS_SOFT_DIRTY) {
ac46d4f3 1305 mmu_notifier_invalidate_range_end(&range);
912efa17
WD		 1306 flush_tlb_mm(mm);
1307 dec_tlb_flush_pending(mm);
1308 }
29a951df
LT		 1309out_unlock:
1310 mmap_write_unlock(mm);
695f0559 1311out_mm:
f248dcb3
MM		 1312 mmput(mm);
1313 }
1314 put_task_struct(task);
fb92a4b0
VL		 1315
1316 return count;
b813e931
DR		 1317}
1318
f248dcb3
MM		 1319const struct file_operations proc_clear_refs_operations = {
1320 .write = clear_refs_write,
6038f373 1321 .llseek = noop_llseek,
f248dcb3
MM		 1322};
1323
092b50ba
NH		 1324typedef struct {
1325 u64 pme;
1326} pagemap_entry_t;
1327
85863e47 1328struct pagemapread {
8c829622 1329 int pos, len; /* units: PM_ENTRY_BYTES, not bytes */
092b50ba 1330 pagemap_entry_t *buffer;
1c90308e 1331 bool show_pfn;
85863e47
MM		 1332};
1333
5aaabe83
NH		 1334#define PAGEMAP_WALK_SIZE (PMD_SIZE)
1335#define PAGEMAP_WALK_MASK (PMD_MASK)
1336
deb94544
KK		 1337#define PM_ENTRY_BYTES sizeof(pagemap_entry_t)
1338#define PM_PFRAME_BITS 55
1339#define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
1340#define PM_SOFT_DIRTY BIT_ULL(55)
77bb499b 1341#define PM_MMAP_EXCLUSIVE BIT_ULL(56)
fb8e37f3 1342#define PM_UFFD_WP BIT_ULL(57)
deb94544
KK		 1343#define PM_FILE BIT_ULL(61)
1344#define PM_SWAP BIT_ULL(62)
1345#define PM_PRESENT BIT_ULL(63)
1346
85863e47
MM		 1347#define PM_END_OF_BUFFER 1
1348
deb94544 1349static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
092b50ba 1350{
deb94544 1351 return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
092b50ba
NH		 1352}
1353
1354static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
85863e47
MM		 1355 struct pagemapread *pm)
1356{
092b50ba 1357 pm->buffer[pm->pos++] = *pme;
d82ef020 1358 if (pm->pos >= pm->len)
aae8679b 1359 return PM_END_OF_BUFFER;
85863e47
MM		 1360 return 0;
1361}
1362
1363static int pagemap_pte_hole(unsigned long start, unsigned long end,
b7a16c7a 1364 __always_unused int depth, struct mm_walk *walk)
85863e47 1365{
2165009b 1366 struct pagemapread *pm = walk->private;
68b5a652 1367 unsigned long addr = start;
85863e47 1368 int err = 0;
092b50ba 1369
68b5a652
PF		 1370 while (addr < end) {
1371 struct vm_area_struct *vma = find_vma(walk->mm, addr);
deb94544 1372 pagemap_entry_t pme = make_pme(0, 0);
87e6d49a
PF		 1373 /* End of address space hole, which we mark as non-present. */
1374 unsigned long hole_end;
68b5a652 1375
87e6d49a
PF		 1376 if (vma)
1377 hole_end = min(end, vma->vm_start);
1378 else
1379 hole_end = end;
1380
1381 for (; addr < hole_end; addr += PAGE_SIZE) {
1382 err = add_to_pagemap(addr, &pme, pm);
1383 if (err)
1384 goto out;
68b5a652
PF		 1385 }
1386
87e6d49a
PF		 1387 if (!vma)
1388 break;
1389
1390 /* Addresses in the VMA. */
1391 if (vma->vm_flags & VM_SOFTDIRTY)
deb94544 1392 pme = make_pme(0, PM_SOFT_DIRTY);
87e6d49a 1393 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
68b5a652
PF		 1394 err = add_to_pagemap(addr, &pme, pm);
1395 if (err)
1396 goto out;
1397 }
85863e47 1398 }
68b5a652 1399out:
85863e47
MM		 1400 return err;
1401}
1402
deb94544 1403static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
052fb0d6 1404 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
85863e47 1405{
deb94544 1406 u64 frame = 0, flags = 0;
052fb0d6 1407 struct page *page = NULL;
24d7275c 1408 bool migration = false;
85863e47 1409
052fb0d6 1410 if (pte_present(pte)) {
1c90308e
KK		 1411 if (pm->show_pfn)
1412 frame = pte_pfn(pte);
deb94544 1413 flags |= PM_PRESENT;
25b2995a 1414 page = vm_normal_page(vma, addr, pte);
e9cdd6e7 1415 if (pte_soft_dirty(pte))
deb94544 1416 flags |= PM_SOFT_DIRTY;
fb8e37f3
PX		 1417 if (pte_uffd_wp(pte))
1418 flags |= PM_UFFD_WP;
052fb0d6 1419 } else if (is_swap_pte(pte)) {
179ef71c
CG		 1420 swp_entry_t entry;
1421 if (pte_swp_soft_dirty(pte))
deb94544 1422 flags |= PM_SOFT_DIRTY;
fb8e37f3
PX		 1423 if (pte_swp_uffd_wp(pte))
1424 flags |= PM_UFFD_WP;
179ef71c 1425 entry = pte_to_swp_entry(pte);
0d206b5d
PX		 1426 if (pm->show_pfn) {
1427 pgoff_t offset;
1428 /*
1429 * For PFN swap offsets, keeping the offset field
1430 * to be PFN only to be compatible with old smaps.
1431 */
1432 if (is_pfn_swap_entry(entry))
1433 offset = swp_offset_pfn(entry);
1434 else
1435 offset = swp_offset(entry);
ab6ecf24 1436 frame = swp_type(entry) |
0d206b5d
PX		 1437 (offset << MAX_SWAPFILES_SHIFT);
1438 }
deb94544 1439 flags |= PM_SWAP;
24d7275c 1440 migration = is_migration_entry(entry);
af5cdaf8
AP		 1441 if (is_pfn_swap_entry(entry))
1442 page = pfn_swap_entry_to_page(entry);
8e165e73
PX		 1443 if (pte_marker_entry_uffd_wp(entry))
1444 flags |= PM_UFFD_WP;
052fb0d6
KK		 1445 }
1446
1447 if (page && !PageAnon(page))
1448 flags |= PM_FILE;
24d7275c 1449 if (page && !migration && page_mapcount(page) == 1)
77bb499b 1450 flags |= PM_MMAP_EXCLUSIVE;
deb94544
KK		 1451 if (vma->vm_flags & VM_SOFTDIRTY)
1452 flags |= PM_SOFT_DIRTY;
052fb0d6 1453
deb94544 1454 return make_pme(frame, flags);
bcf8039e
DH		 1455}
1456
356515e7 1457static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
2165009b 1458 struct mm_walk *walk)
85863e47 1459{
f995ece2 1460 struct vm_area_struct *vma = walk->vma;
2165009b 1461 struct pagemapread *pm = walk->private;
bf929152 1462 spinlock_t *ptl;
05fbf357 1463 pte_t *pte, *orig_pte;
85863e47 1464 int err = 0;
356515e7 1465#ifdef CONFIG_TRANSPARENT_HUGEPAGE
24d7275c
YS		 1466 bool migration = false;
1467
b6ec57f4
KS		 1468 ptl = pmd_trans_huge_lock(pmdp, vma);
1469 if (ptl) {
356515e7
KK		 1470 u64 flags = 0, frame = 0;
1471 pmd_t pmd = *pmdp;
84c3fc4e 1472 struct page *page = NULL;
0f8975ec 1473
b83d7e43 1474 if (vma->vm_flags & VM_SOFTDIRTY)
deb94544 1475 flags |= PM_SOFT_DIRTY;
d9104d1c 1476
356515e7 1477 if (pmd_present(pmd)) {
84c3fc4e 1478 page = pmd_page(pmd);
77bb499b 1479
356515e7 1480 flags |= PM_PRESENT;
b83d7e43
HY		 1481 if (pmd_soft_dirty(pmd))
1482 flags |= PM_SOFT_DIRTY;
fb8e37f3
PX		 1483 if (pmd_uffd_wp(pmd))
1484 flags |= PM_UFFD_WP;
1c90308e
KK		 1485 if (pm->show_pfn)
1486 frame = pmd_pfn(pmd) +
1487 ((addr & ~PMD_MASK) >> PAGE_SHIFT);
356515e7 1488 }
84c3fc4e
ZY		 1489#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1490 else if (is_swap_pmd(pmd)) {
1491 swp_entry_t entry = pmd_to_swp_entry(pmd);
ab6ecf24 1492 unsigned long offset;
84c3fc4e 1493
ab6ecf24 1494 if (pm->show_pfn) {
0d206b5d
PX		 1495 if (is_pfn_swap_entry(entry))
1496 offset = swp_offset_pfn(entry);
1497 else
1498 offset = swp_offset(entry);
1499 offset = offset +
ab6ecf24
HY		 1500 ((addr & ~PMD_MASK) >> PAGE_SHIFT);
1501 frame = swp_type(entry) |
1502 (offset << MAX_SWAPFILES_SHIFT);
1503 }
84c3fc4e 1504 flags |= PM_SWAP;
b83d7e43
HY		 1505 if (pmd_swp_soft_dirty(pmd))
1506 flags |= PM_SOFT_DIRTY;
fb8e37f3
PX		 1507 if (pmd_swp_uffd_wp(pmd))
1508 flags |= PM_UFFD_WP;
84c3fc4e 1509 VM_BUG_ON(!is_pmd_migration_entry(pmd));
24d7275c 1510 migration = is_migration_entry(entry);
af5cdaf8 1511 page = pfn_swap_entry_to_page(entry);
84c3fc4e
ZY		 1512 }
1513#endif
1514
24d7275c 1515 if (page && !migration && page_mapcount(page) == 1)
84c3fc4e 1516 flags |= PM_MMAP_EXCLUSIVE;
356515e7 1517
025c5b24 1518 for (; addr != end; addr += PAGE_SIZE) {
356515e7 1519 pagemap_entry_t pme = make_pme(frame, flags);
025c5b24 1520
092b50ba 1521 err = add_to_pagemap(addr, &pme, pm);
025c5b24
NH		 1522 if (err)
1523 break;
ab6ecf24
HY		 1524 if (pm->show_pfn) {
1525 if (flags & PM_PRESENT)
1526 frame++;
1527 else if (flags & PM_SWAP)
1528 frame += (1 << MAX_SWAPFILES_SHIFT);
1529 }
5aaabe83 1530 }
bf929152 1531 spin_unlock(ptl);
025c5b24 1532 return err;
5aaabe83 1533 }
356515e7 1534#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
81d0fa62 1535
f995ece2
NH		 1536 /*
1537 * We can assume that @vma always points to a valid one and @end never
1538 * goes beyond vma->vm_end.
1539 */
356515e7 1540 orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
7780d040
HD		 1541 if (!pte) {
1542 walk->action = ACTION_AGAIN;
1543 return err;
1544 }
f995ece2
NH		 1545 for (; addr < end; pte++, addr += PAGE_SIZE) {
1546 pagemap_entry_t pme;
05fbf357 1547
c33c7948 1548 pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
f995ece2 1549 err = add_to_pagemap(addr, &pme, pm);
05fbf357 1550 if (err)
81d0fa62 1551 break;
85863e47 1552 }
f995ece2 1553 pte_unmap_unlock(orig_pte, ptl);
85863e47
MM		 1554
1555 cond_resched();
1556
1557 return err;
1558}
1559
1a5cb814 1560#ifdef CONFIG_HUGETLB_PAGE
116354d1 1561/* This function walks within one hugetlb entry in the single call */
356515e7 1562static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
116354d1
NH		 1563 unsigned long addr, unsigned long end,
1564 struct mm_walk *walk)
5dc37642 1565{
5dc37642 1566 struct pagemapread *pm = walk->private;
f995ece2 1567 struct vm_area_struct *vma = walk->vma;
356515e7 1568 u64 flags = 0, frame = 0;
5dc37642 1569 int err = 0;
356515e7 1570 pte_t pte;
5dc37642 1571
f995ece2 1572 if (vma->vm_flags & VM_SOFTDIRTY)
deb94544 1573 flags |= PM_SOFT_DIRTY;
d9104d1c 1574
356515e7
KK		 1575 pte = huge_ptep_get(ptep);
1576 if (pte_present(pte)) {
1577 struct page *page = pte_page(pte);
1578
1579 if (!PageAnon(page))
1580 flags |= PM_FILE;
1581
77bb499b
KK		 1582 if (page_mapcount(page) == 1)
1583 flags |= PM_MMAP_EXCLUSIVE;
1584
8e165e73
PX		 1585 if (huge_pte_uffd_wp(pte))
1586 flags |= PM_UFFD_WP;
1587
356515e7 1588 flags |= PM_PRESENT;
1c90308e
KK		 1589 if (pm->show_pfn)
1590 frame = pte_pfn(pte) +
1591 ((addr & ~hmask) >> PAGE_SHIFT);
8e165e73
PX		 1592 } else if (pte_swp_uffd_wp_any(pte)) {
1593 flags |= PM_UFFD_WP;
356515e7
KK		 1594 }
1595
5dc37642 1596 for (; addr != end; addr += PAGE_SIZE) {
356515e7
KK		 1597 pagemap_entry_t pme = make_pme(frame, flags);
1598
092b50ba 1599 err = add_to_pagemap(addr, &pme, pm);
5dc37642
NH		 1600 if (err)
1601 return err;
1c90308e 1602 if (pm->show_pfn && (flags & PM_PRESENT))
356515e7 1603 frame++;
5dc37642
NH		 1604 }
1605
1606 cond_resched();
1607
1608 return err;
1609}
7b86ac33
CH		 1610#else
1611#define pagemap_hugetlb_range NULL
1a5cb814 1612#endif /* HUGETLB_PAGE */
5dc37642 1613
7b86ac33
CH		 1614static const struct mm_walk_ops pagemap_ops = {
1615 .pmd_entry = pagemap_pmd_range,
1616 .pte_hole = pagemap_pte_hole,
1617 .hugetlb_entry = pagemap_hugetlb_range,
49b06385 1618 .walk_lock = PGWALK_RDLOCK,
7b86ac33
CH		 1619};
1620
85863e47
MM		 1621/*
1622 * /proc/pid/pagemap - an array mapping virtual pages to pfns
1623 *
f16278c6
HR		 1624 * For each page in the address space, this file contains one 64-bit entry
1625 * consisting of the following:
1626 *
052fb0d6 1627 * Bits 0-54 page frame number (PFN) if present
f16278c6 1628 * Bits 0-4 swap type if swapped
052fb0d6 1629 * Bits 5-54 swap offset if swapped
1ad1335d 1630 * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
77bb499b 1631 * Bit 56 page exclusively mapped
dd21bfa4
YZ		 1632 * Bit 57 pte is uffd-wp write-protected
1633 * Bits 58-60 zero
052fb0d6 1634 * Bit 61 page is file-page or shared-anon
f16278c6
HR		 1635 * Bit 62 page swapped
1636 * Bit 63 page present
1637 *
1638 * If the page is not present but in swap, then the PFN contains an
1639 * encoding of the swap file number and the page's offset into the
1640 * swap. Unmapped pages return a null PFN. This allows determining
85863e47
MM		 1641 * precisely which pages are mapped (or in swap) and comparing mapped
1642 * pages between processes.
1643 *
1644 * Efficient users of this interface will use /proc/pid/maps to
1645 * determine which areas of memory are actually mapped and llseek to
1646 * skip over unmapped regions.
1647 */
1648static ssize_t pagemap_read(struct file *file, char __user *buf,
1649 size_t count, loff_t *ppos)
1650{
a06db751 1651 struct mm_struct *mm = file->private_data;
85863e47 1652 struct pagemapread pm;
5d7e0d2b
AM		 1653 unsigned long src;
1654 unsigned long svpfn;
1655 unsigned long start_vaddr;
1656 unsigned long end_vaddr;
a06db751 1657 int ret = 0, copied = 0;
85863e47 1658
388f7934 1659 if (!mm || !mmget_not_zero(mm))
85863e47
MM		 1660 goto out;
1661
85863e47
MM		 1662 ret = -EINVAL;
1663 /* file position must be aligned */
aae8679b 1664 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
a06db751 1665 goto out_mm;
85863e47
MM		 1666
1667 ret = 0;
08161786 1668 if (!count)
a06db751 1669 goto out_mm;
08161786 1670
1c90308e
KK		 1671 /* do not disclose physical addresses: attack vector */
1672 pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
1673
8c829622 1674 pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
6da2ec56 1675 pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
5d7e0d2b 1676 ret = -ENOMEM;
d82ef020 1677 if (!pm.buffer)
a06db751 1678 goto out_mm;
85863e47 1679
5d7e0d2b
AM		 1680 src = *ppos;
1681 svpfn = src / PM_ENTRY_BYTES;
a06db751 1682 end_vaddr = mm->task_size;
5d7e0d2b
AM		 1683
1684 /* watch out for wraparound */
40d6366e 1685 start_vaddr = end_vaddr;
428e106a 1686 if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) {
7bab8dfb
YX		 1687 unsigned long end;
1688
428e106a
KS		 1689 ret = mmap_read_lock_killable(mm);
1690 if (ret)
1691 goto out_free;
1692 start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
1693 mmap_read_unlock(mm);
7bab8dfb
YX		 1694
1695 end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
1696 if (end >= start_vaddr && end < mm->task_size)
1697 end_vaddr = end;
428e106a 1698 }
40d6366e
MC		 1699
1700 /* Ensure the address is inside the task */
1701 if (start_vaddr > mm->task_size)
5d7e0d2b
AM		 1702 start_vaddr = end_vaddr;
1703
d82ef020
KH		 1704 ret = 0;
1705 while (count && (start_vaddr < end_vaddr)) {
1706 int len;
1707 unsigned long end;
1708
1709 pm.pos = 0;
ea251c1d 1710 end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
d82ef020
KH		 1711 /* overflow ? */
1712 if (end < start_vaddr || end > end_vaddr)
1713 end = end_vaddr;
d8ed45c5 1714 ret = mmap_read_lock_killable(mm);
ad80b932
KK		 1715 if (ret)
1716 goto out_free;
7b86ac33 1717 ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
d8ed45c5 1718 mmap_read_unlock(mm);
d82ef020
KH		 1719 start_vaddr = end;
1720
1721 len = min(count, PM_ENTRY_BYTES * pm.pos);
309361e0 1722 if (copy_to_user(buf, pm.buffer, len)) {
d82ef020 1723 ret = -EFAULT;
a06db751 1724 goto out_free;
d82ef020
KH		 1725 }
1726 copied += len;
1727 buf += len;
1728 count -= len;
85863e47 1729 }
d82ef020
KH		 1730 *ppos += copied;
1731 if (!ret || ret == PM_END_OF_BUFFER)
1732 ret = copied;
1733
98bc93e5
KM		 1734out_free:
1735 kfree(pm.buffer);
a06db751
KK		 1736out_mm:
1737 mmput(mm);
85863e47
MM		 1738out:
1739 return ret;
1740}
1741
541c237c
PE		 1742static int pagemap_open(struct inode *inode, struct file *file)
1743{
a06db751
KK		 1744 struct mm_struct *mm;
1745
a06db751
KK		 1746 mm = proc_mem_open(inode, PTRACE_MODE_READ);
1747 if (IS_ERR(mm))
1748 return PTR_ERR(mm);
1749 file->private_data = mm;
1750 return 0;
1751}
1752
1753static int pagemap_release(struct inode *inode, struct file *file)
1754{
1755 struct mm_struct *mm = file->private_data;
1756
1757 if (mm)
1758 mmdrop(mm);
541c237c
PE		 1759 return 0;
1760}
1761
52526ca7
MUA		 1762#define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \
1763 PAGE_IS_FILE | PAGE_IS_PRESENT | \
1764 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \
1765 PAGE_IS_HUGE)
1766#define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC)
1767
1768struct pagemap_scan_private {
1769 struct pm_scan_arg arg;
1770 unsigned long masks_of_interest, cur_vma_category;
1771 struct page_region *vec_buf;
1772 unsigned long vec_buf_len, vec_buf_index, found_pages;
1773 struct page_region __user *vec_out;
1774};
1775
1776static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
1777 struct vm_area_struct *vma,
1778 unsigned long addr, pte_t pte)
1779{
1780 unsigned long categories = 0;
1781
1782 if (pte_present(pte)) {
1783 struct page *page;
1784
1785 categories |= PAGE_IS_PRESENT;
1786 if (!pte_uffd_wp(pte))
1787 categories |= PAGE_IS_WRITTEN;
1788
1789 if (p->masks_of_interest & PAGE_IS_FILE) {
1790 page = vm_normal_page(vma, addr, pte);
1791 if (page && !PageAnon(page))
1792 categories |= PAGE_IS_FILE;
1793 }
1794
1795 if (is_zero_pfn(pte_pfn(pte)))
1796 categories |= PAGE_IS_PFNZERO;
1797 } else if (is_swap_pte(pte)) {
1798 swp_entry_t swp;
1799
1800 categories |= PAGE_IS_SWAPPED;
1801 if (!pte_swp_uffd_wp_any(pte))
1802 categories |= PAGE_IS_WRITTEN;
1803
1804 if (p->masks_of_interest & PAGE_IS_FILE) {
1805 swp = pte_to_swp_entry(pte);
1806 if (is_pfn_swap_entry(swp) &&
1807 !PageAnon(pfn_swap_entry_to_page(swp)))
1808 categories |= PAGE_IS_FILE;
1809 }
1810 }
1811
1812 return categories;
1813}
1814
1815static void make_uffd_wp_pte(struct vm_area_struct *vma,
1816 unsigned long addr, pte_t *pte)
1817{
1818 pte_t ptent = ptep_get(pte);
1819
1820 if (pte_present(ptent)) {
1821 pte_t old_pte;
1822
1823 old_pte = ptep_modify_prot_start(vma, addr, pte);
1824 ptent = pte_mkuffd_wp(ptent);
1825 ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
1826 } else if (is_swap_pte(ptent)) {
1827 ptent = pte_swp_mkuffd_wp(ptent);
1828 set_pte_at(vma->vm_mm, addr, pte, ptent);
1829 } else {
1830 set_pte_at(vma->vm_mm, addr, pte,
1831 make_pte_marker(PTE_MARKER_UFFD_WP));
1832 }
1833}
1834
1835#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1836static unsigned long pagemap_thp_category(struct pagemap_scan_private *p,
1837 struct vm_area_struct *vma,
1838 unsigned long addr, pmd_t pmd)
1839{
1840 unsigned long categories = PAGE_IS_HUGE;
1841
1842 if (pmd_present(pmd)) {
1843 struct page *page;
1844
1845 categories |= PAGE_IS_PRESENT;
1846 if (!pmd_uffd_wp(pmd))
1847 categories |= PAGE_IS_WRITTEN;
1848
1849 if (p->masks_of_interest & PAGE_IS_FILE) {
1850 page = vm_normal_page_pmd(vma, addr, pmd);
1851 if (page && !PageAnon(page))
1852 categories |= PAGE_IS_FILE;
1853 }
1854
1855 if (is_zero_pfn(pmd_pfn(pmd)))
1856 categories |= PAGE_IS_PFNZERO;
1857 } else if (is_swap_pmd(pmd)) {
1858 swp_entry_t swp;
1859
1860 categories |= PAGE_IS_SWAPPED;
1861 if (!pmd_swp_uffd_wp(pmd))
1862 categories |= PAGE_IS_WRITTEN;
1863
1864 if (p->masks_of_interest & PAGE_IS_FILE) {
1865 swp = pmd_to_swp_entry(pmd);
1866 if (is_pfn_swap_entry(swp) &&
1867 !PageAnon(pfn_swap_entry_to_page(swp)))
1868 categories |= PAGE_IS_FILE;
1869 }
1870 }
1871
1872 return categories;
1873}
1874
1875static void make_uffd_wp_pmd(struct vm_area_struct *vma,
1876 unsigned long addr, pmd_t *pmdp)
1877{
1878 pmd_t old, pmd = *pmdp;
1879
1880 if (pmd_present(pmd)) {
1881 old = pmdp_invalidate_ad(vma, addr, pmdp);
1882 pmd = pmd_mkuffd_wp(old);
1883 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1884 } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
1885 pmd = pmd_swp_mkuffd_wp(pmd);
1886 set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
1887 }
1888}
1889#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1890
1891#ifdef CONFIG_HUGETLB_PAGE
1892static unsigned long pagemap_hugetlb_category(pte_t pte)
1893{
1894 unsigned long categories = PAGE_IS_HUGE;
1895
1896 /*
1897 * According to pagemap_hugetlb_range(), file-backed HugeTLB
1898 * page cannot be swapped. So PAGE_IS_FILE is not checked for
1899 * swapped pages.
1900 */
1901 if (pte_present(pte)) {
1902 categories |= PAGE_IS_PRESENT;
1903 if (!huge_pte_uffd_wp(pte))
1904 categories |= PAGE_IS_WRITTEN;
1905 if (!PageAnon(pte_page(pte)))
1906 categories |= PAGE_IS_FILE;
1907 if (is_zero_pfn(pte_pfn(pte)))
1908 categories |= PAGE_IS_PFNZERO;
1909 } else if (is_swap_pte(pte)) {
1910 categories |= PAGE_IS_SWAPPED;
1911 if (!pte_swp_uffd_wp_any(pte))
1912 categories |= PAGE_IS_WRITTEN;
1913 }
1914
1915 return categories;
1916}
1917
1918static void make_uffd_wp_huge_pte(struct vm_area_struct *vma,
1919 unsigned long addr, pte_t *ptep,
1920 pte_t ptent)
1921{
1922 unsigned long psize;
1923
1924 if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent))
1925 return;
1926
1927 psize = huge_page_size(hstate_vma(vma));
1928
1929 if (is_hugetlb_entry_migration(ptent))
1930 set_huge_pte_at(vma->vm_mm, addr, ptep,
1931 pte_swp_mkuffd_wp(ptent), psize);
1932 else if (!huge_pte_none(ptent))
1933 huge_ptep_modify_prot_commit(vma, addr, ptep, ptent,
1934 huge_pte_mkuffd_wp(ptent));
1935 else
1936 set_huge_pte_at(vma->vm_mm, addr, ptep,
1937 make_pte_marker(PTE_MARKER_UFFD_WP), psize);
1938}
1939#endif /* CONFIG_HUGETLB_PAGE */
1940
1941#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
1942static void pagemap_scan_backout_range(struct pagemap_scan_private *p,
1943 unsigned long addr, unsigned long end)
1944{
1945 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
1946
1947 if (cur_buf->start != addr)
1948 cur_buf->end = addr;
1949 else
1950 cur_buf->start = cur_buf->end = 0;
1951
1952 p->found_pages -= (end - addr) / PAGE_SIZE;
1953}
1954#endif
1955
1956static bool pagemap_scan_is_interesting_page(unsigned long categories,
1957 const struct pagemap_scan_private *p)
1958{
1959 categories ^= p->arg.category_inverted;
1960 if ((categories & p->arg.category_mask) != p->arg.category_mask)
1961 return false;
1962 if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask))
1963 return false;
1964
1965 return true;
1966}
1967
1968static bool pagemap_scan_is_interesting_vma(unsigned long categories,
1969 const struct pagemap_scan_private *p)
1970{
1971 unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED;
1972
1973 categories ^= p->arg.category_inverted;
1974 if ((categories & required) != required)
1975 return false;
1976
1977 return true;
1978}
1979
1980static int pagemap_scan_test_walk(unsigned long start, unsigned long end,
1981 struct mm_walk *walk)
1982{
1983 struct pagemap_scan_private *p = walk->private;
1984 struct vm_area_struct *vma = walk->vma;
1985 unsigned long vma_category = 0;
1986
1987 if (userfaultfd_wp_async(vma) && userfaultfd_wp_use_markers(vma))
1988 vma_category |= PAGE_IS_WPALLOWED;
1989 else if (p->arg.flags & PM_SCAN_CHECK_WPASYNC)
1990 return -EPERM;
1991
1992 if (vma->vm_flags & VM_PFNMAP)
1993 return 1;
1994
1995 if (!pagemap_scan_is_interesting_vma(vma_category, p))
1996 return 1;
1997
1998 p->cur_vma_category = vma_category;
1999
2000 return 0;
2001}
2002
2003static bool pagemap_scan_push_range(unsigned long categories,
2004 struct pagemap_scan_private *p,
2005 unsigned long addr, unsigned long end)
2006{
2007 struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
2008
2009 /*
2010 * When there is no output buffer provided at all, the sentinel values
2011 * won't match here. There is no other way for `cur_buf->end` to be
2012 * non-zero other than it being non-empty.
2013 */
2014 if (addr == cur_buf->end && categories == cur_buf->categories) {
2015 cur_buf->end = end;
2016 return true;
2017 }
2018
2019 if (cur_buf->end) {
2020 if (p->vec_buf_index >= p->vec_buf_len - 1)
2021 return false;
2022
2023 cur_buf = &p->vec_buf[++p->vec_buf_index];
2024 }
2025
2026 cur_buf->start = addr;
2027 cur_buf->end = end;
2028 cur_buf->categories = categories;
2029
2030 return true;
2031}
2032
2033static int pagemap_scan_output(unsigned long categories,
2034 struct pagemap_scan_private *p,
2035 unsigned long addr, unsigned long *end)
2036{
2037 unsigned long n_pages, total_pages;
2038 int ret = 0;
2039
2040 if (!p->vec_buf)
2041 return 0;
2042
2043 categories &= p->arg.return_mask;
2044
2045 n_pages = (*end - addr) / PAGE_SIZE;
2046 if (check_add_overflow(p->found_pages, n_pages, &total_pages) ||
2047 total_pages > p->arg.max_pages) {
2048 size_t n_too_much = total_pages - p->arg.max_pages;
2049 *end -= n_too_much * PAGE_SIZE;
2050 n_pages -= n_too_much;
2051 ret = -ENOSPC;
2052 }
2053
2054 if (!pagemap_scan_push_range(categories, p, addr, *end)) {
2055 *end = addr;
2056 n_pages = 0;
2057 ret = -ENOSPC;
2058 }
2059
2060 p->found_pages += n_pages;
2061 if (ret)
2062 p->arg.walk_end = *end;
2063
2064 return ret;
2065}
2066
2067static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start,
2068 unsigned long end, struct mm_walk *walk)
2069{
2070#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2071 struct pagemap_scan_private *p = walk->private;
2072 struct vm_area_struct *vma = walk->vma;
2073 unsigned long categories;
2074 spinlock_t *ptl;
2075 int ret = 0;
2076
2077 ptl = pmd_trans_huge_lock(pmd, vma);
2078 if (!ptl)
2079 return -ENOENT;
2080
2081 categories = p->cur_vma_category |
2082 pagemap_thp_category(p, vma, start, *pmd);
2083
2084 if (!pagemap_scan_is_interesting_page(categories, p))
2085 goto out_unlock;
2086
2087 ret = pagemap_scan_output(categories, p, start, &end);
2088 if (start == end)
2089 goto out_unlock;
2090
2091 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2092 goto out_unlock;
2093 if (~categories & PAGE_IS_WRITTEN)
2094 goto out_unlock;
2095
2096 /*
2097 * Break huge page into small pages if the WP operation
2098 * needs to be performed on a portion of the huge page.
2099 */
2100 if (end != start + HPAGE_SIZE) {
2101 spin_unlock(ptl);
2102 split_huge_pmd(vma, pmd, start);
2103 pagemap_scan_backout_range(p, start, end);
2104 /* Report as if there was no THP */
2105 return -ENOENT;
2106 }
2107
2108 make_uffd_wp_pmd(vma, start, pmd);
2109 flush_tlb_range(vma, start, end);
2110out_unlock:
2111 spin_unlock(ptl);
2112 return ret;
2113#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
2114 return -ENOENT;
2115#endif
2116}
2117
2118static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
2119 unsigned long end, struct mm_walk *walk)
2120{
2121 struct pagemap_scan_private *p = walk->private;
2122 struct vm_area_struct *vma = walk->vma;
2123 unsigned long addr, flush_end = 0;
2124 pte_t *pte, *start_pte;
2125 spinlock_t *ptl;
2126 int ret;
2127
2128 arch_enter_lazy_mmu_mode();
2129
2130 ret = pagemap_scan_thp_entry(pmd, start, end, walk);
2131 if (ret != -ENOENT) {
2132 arch_leave_lazy_mmu_mode();
2133 return ret;
2134 }
2135
2136 ret = 0;
2137 start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl);
2138 if (!pte) {
2139 arch_leave_lazy_mmu_mode();
2140 walk->action = ACTION_AGAIN;
2141 return 0;
2142 }
2143
12f6b01a
MUA		 2144 if (!p->vec_out) {
2145 /* Fast path for performing exclusive WP */
2146 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
2147 if (pte_uffd_wp(ptep_get(pte)))
2148 continue;
2149 make_uffd_wp_pte(vma, addr, pte);
2150 if (!flush_end)
2151 start = addr;
2152 flush_end = addr + PAGE_SIZE;
2153 }
2154 goto flush_and_return;
2155 }
2156
2157 if (!p->arg.category_anyof_mask && !p->arg.category_inverted &&
2158 p->arg.category_mask == PAGE_IS_WRITTEN &&
2159 p->arg.return_mask == PAGE_IS_WRITTEN) {
2160 for (addr = start; addr < end; pte++, addr += PAGE_SIZE) {
2161 unsigned long next = addr + PAGE_SIZE;
2162
2163 if (pte_uffd_wp(ptep_get(pte)))
2164 continue;
2165 ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN,
2166 p, addr, &next);
2167 if (next == addr)
2168 break;
2169 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2170 continue;
2171 make_uffd_wp_pte(vma, addr, pte);
2172 if (!flush_end)
2173 start = addr;
2174 flush_end = next;
2175 }
2176 goto flush_and_return;
2177 }
2178
52526ca7
MUA		 2179 for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
2180 unsigned long categories = p->cur_vma_category |
2181 pagemap_page_category(p, vma, addr, ptep_get(pte));
2182 unsigned long next = addr + PAGE_SIZE;
2183
2184 if (!pagemap_scan_is_interesting_page(categories, p))
2185 continue;
2186
2187 ret = pagemap_scan_output(categories, p, addr, &next);
2188 if (next == addr)
2189 break;
2190
2191 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2192 continue;
2193 if (~categories & PAGE_IS_WRITTEN)
2194 continue;
2195
2196 make_uffd_wp_pte(vma, addr, pte);
2197 if (!flush_end)
2198 start = addr;
2199 flush_end = next;
2200 }
2201
12f6b01a 2202flush_and_return:
52526ca7
MUA		 2203 if (flush_end)
2204 flush_tlb_range(vma, start, addr);
2205
2206 pte_unmap_unlock(start_pte, ptl);
2207 arch_leave_lazy_mmu_mode();
2208
2209 cond_resched();
2210 return ret;
2211}
2212
2213#ifdef CONFIG_HUGETLB_PAGE
2214static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
2215 unsigned long start, unsigned long end,
2216 struct mm_walk *walk)
2217{
2218 struct pagemap_scan_private *p = walk->private;
2219 struct vm_area_struct *vma = walk->vma;
2220 unsigned long categories;
2221 spinlock_t *ptl;
2222 int ret = 0;
2223 pte_t pte;
2224
2225 if (~p->arg.flags & PM_SCAN_WP_MATCHING) {
2226 /* Go the short route when not write-protecting pages. */
2227
2228 pte = huge_ptep_get(ptep);
2229 categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
2230
2231 if (!pagemap_scan_is_interesting_page(categories, p))
2232 return 0;
2233
2234 return pagemap_scan_output(categories, p, start, &end);
2235 }
2236
2237 i_mmap_lock_write(vma->vm_file->f_mapping);
2238 ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep);
2239
2240 pte = huge_ptep_get(ptep);
2241 categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
2242
2243 if (!pagemap_scan_is_interesting_page(categories, p))
2244 goto out_unlock;
2245
2246 ret = pagemap_scan_output(categories, p, start, &end);
2247 if (start == end)
2248 goto out_unlock;
2249
2250 if (~categories & PAGE_IS_WRITTEN)
2251 goto out_unlock;
2252
2253 if (end != start + HPAGE_SIZE) {
2254 /* Partial HugeTLB page WP isn't possible. */
2255 pagemap_scan_backout_range(p, start, end);
2256 p->arg.walk_end = start;
2257 ret = 0;
2258 goto out_unlock;
2259 }
2260
2261 make_uffd_wp_huge_pte(vma, start, ptep, pte);
2262 flush_hugetlb_tlb_range(vma, start, end);
2263
2264out_unlock:
2265 spin_unlock(ptl);
2266 i_mmap_unlock_write(vma->vm_file->f_mapping);
2267
2268 return ret;
2269}
2270#else
2271#define pagemap_scan_hugetlb_entry NULL
2272#endif
2273
2274static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end,
2275 int depth, struct mm_walk *walk)
2276{
2277 struct pagemap_scan_private *p = walk->private;
2278 struct vm_area_struct *vma = walk->vma;
2279 int ret, err;
2280
2281 if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p))
2282 return 0;
2283
2284 ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end);
2285 if (addr == end)
2286 return ret;
2287
2288 if (~p->arg.flags & PM_SCAN_WP_MATCHING)
2289 return ret;
2290
2291 err = uffd_wp_range(vma, addr, end - addr, true);
2292 if (err < 0)
2293 ret = err;
2294
2295 return ret;
2296}
2297
2298static const struct mm_walk_ops pagemap_scan_ops = {
2299 .test_walk = pagemap_scan_test_walk,
2300 .pmd_entry = pagemap_scan_pmd_entry,
2301 .pte_hole = pagemap_scan_pte_hole,
2302 .hugetlb_entry = pagemap_scan_hugetlb_entry,
2303};
2304
2305static int pagemap_scan_get_args(struct pm_scan_arg *arg,
2306 unsigned long uarg)
2307{
2308 if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg)))
2309 return -EFAULT;
2310
2311 if (arg->size != sizeof(struct pm_scan_arg))
2312 return -EINVAL;
2313
2314 /* Validate requested features */
2315 if (arg->flags & ~PM_SCAN_FLAGS)
2316 return -EINVAL;
2317 if ((arg->category_inverted | arg->category_mask |
2318 arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES)
2319 return -EINVAL;
2320
2321 arg->start = untagged_addr((unsigned long)arg->start);
2322 arg->end = untagged_addr((unsigned long)arg->end);
2323 arg->vec = untagged_addr((unsigned long)arg->vec);
2324
2325 /* Validate memory pointers */
2326 if (!IS_ALIGNED(arg->start, PAGE_SIZE))
2327 return -EINVAL;
2328 if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start))
2329 return -EFAULT;
2330 if (!arg->vec && arg->vec_len)
2331 return -EINVAL;
2332 if (arg->vec && !access_ok((void __user *)(long)arg->vec,
2333 arg->vec_len * sizeof(struct page_region)))
2334 return -EFAULT;
2335
2336 /* Fixup default values */
2337 arg->end = ALIGN(arg->end, PAGE_SIZE);
2338 arg->walk_end = 0;
2339 if (!arg->max_pages)
2340 arg->max_pages = ULONG_MAX;
2341
2342 return 0;
2343}
2344
2345static int pagemap_scan_writeback_args(struct pm_scan_arg *arg,
2346 unsigned long uargl)
2347{
2348 struct pm_scan_arg __user *uarg = (void __user *)uargl;
2349
2350 if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end)))
2351 return -EFAULT;
2352
2353 return 0;
2354}
2355
2356static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p)
2357{
2358 if (!p->arg.vec_len)
2359 return 0;
2360
2361 p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT,
2362 p->arg.vec_len);
2363 p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf),
2364 GFP_KERNEL);
2365 if (!p->vec_buf)
2366 return -ENOMEM;
2367
2368 p->vec_buf->start = p->vec_buf->end = 0;
2369 p->vec_out = (struct page_region __user *)(long)p->arg.vec;
2370
2371 return 0;
2372}
2373
2374static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p)
2375{
2376 const struct page_region *buf = p->vec_buf;
2377 long n = p->vec_buf_index;
2378
2379 if (!p->vec_buf)
2380 return 0;
2381
2382 if (buf[n].end != buf[n].start)
2383 n++;
2384
2385 if (!n)
2386 return 0;
2387
2388 if (copy_to_user(p->vec_out, buf, n * sizeof(*buf)))
2389 return -EFAULT;
2390
2391 p->arg.vec_len -= n;
2392 p->vec_out += n;
2393
2394 p->vec_buf_index = 0;
2395 p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len);
2396 p->vec_buf->start = p->vec_buf->end = 0;
2397
2398 return n;
2399}
2400
2401static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg)
2402{
2403 struct mmu_notifier_range range;
2404 struct pagemap_scan_private p = {0};
2405 unsigned long walk_start;
2406 size_t n_ranges_out = 0;
2407 int ret;
2408
2409 ret = pagemap_scan_get_args(&p.arg, uarg);
2410 if (ret)
2411 return ret;
2412
2413 p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask |
2414 p.arg.return_mask;
2415 ret = pagemap_scan_init_bounce_buffer(&p);
2416 if (ret)
2417 return ret;
2418
2419 /* Protection change for the range is going to happen. */
2420 if (p.arg.flags & PM_SCAN_WP_MATCHING) {
2421 mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0,
2422 mm, p.arg.start, p.arg.end);
2423 mmu_notifier_invalidate_range_start(&range);
2424 }
2425
2426 for (walk_start = p.arg.start; walk_start < p.arg.end;
2427 walk_start = p.arg.walk_end) {
2428 long n_out;
2429
2430 if (fatal_signal_pending(current)) {
2431 ret = -EINTR;
2432 break;
2433 }
2434
2435 ret = mmap_read_lock_killable(mm);
2436 if (ret)
2437 break;
2438 ret = walk_page_range(mm, walk_start, p.arg.end,
2439 &pagemap_scan_ops, &p);
2440 mmap_read_unlock(mm);
2441
2442 n_out = pagemap_scan_flush_buffer(&p);
2443 if (n_out < 0)
2444 ret = n_out;
2445 else
2446 n_ranges_out += n_out;
2447
2448 if (ret != -ENOSPC)
2449 break;
2450
2451 if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages)
2452 break;
2453 }
2454
2455 /* ENOSPC signifies early stop (buffer full) from the walk. */
2456 if (!ret || ret == -ENOSPC)
2457 ret = n_ranges_out;
2458
2459 /* The walk_end isn't set when ret is zero */
2460 if (!p.arg.walk_end)
2461 p.arg.walk_end = p.arg.end;
2462 if (pagemap_scan_writeback_args(&p.arg, uarg))
2463 ret = -EFAULT;
2464
2465 if (p.arg.flags & PM_SCAN_WP_MATCHING)
2466 mmu_notifier_invalidate_range_end(&range);
2467
2468 kfree(p.vec_buf);
2469 return ret;
2470}
2471
2472static long do_pagemap_cmd(struct file *file, unsigned int cmd,
2473 unsigned long arg)
2474{
2475 struct mm_struct *mm = file->private_data;
2476
2477 switch (cmd) {
2478 case PAGEMAP_SCAN:
2479 return do_pagemap_scan(mm, arg);
2480
2481 default:
2482 return -EINVAL;
2483 }
2484}
2485
85863e47
MM		 2486const struct file_operations proc_pagemap_operations = {
2487 .llseek = mem_lseek, /* borrow this */
2488 .read = pagemap_read,
541c237c 2489 .open = pagemap_open,
a06db751 2490 .release = pagemap_release,
52526ca7
MUA		 2491 .unlocked_ioctl = do_pagemap_cmd,
2492 .compat_ioctl = do_pagemap_cmd,
85863e47 2493};
1e883281 2494#endif /* CONFIG_PROC_PAGE_MONITOR */
85863e47 2495
6e21c8f1 2496#ifdef CONFIG_NUMA
6e21c8f1 2497
f69ff943 2498struct numa_maps {
f69ff943
SW		 2499 unsigned long pages;
2500 unsigned long anon;
2501 unsigned long active;
2502 unsigned long writeback;
2503 unsigned long mapcount_max;
2504 unsigned long dirty;
2505 unsigned long swapcache;
2506 unsigned long node[MAX_NUMNODES];
2507};
2508
5b52fc89
SW		 2509struct numa_maps_private {
2510 struct proc_maps_private proc_maps;
2511 struct numa_maps md;
2512};
2513
eb4866d0
DH		 2514static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
2515 unsigned long nr_pages)
f69ff943
SW		 2516{
2517 int count = page_mapcount(page);
2518
eb4866d0 2519 md->pages += nr_pages;
f69ff943 2520 if (pte_dirty || PageDirty(page))
eb4866d0 2521 md->dirty += nr_pages;
f69ff943
SW		 2522
2523 if (PageSwapCache(page))
eb4866d0 2524 md->swapcache += nr_pages;
f69ff943
SW		 2525
2526 if (PageActive(page) || PageUnevictable(page))
eb4866d0 2527 md->active += nr_pages;
f69ff943
SW		 2528
2529 if (PageWriteback(page))
eb4866d0 2530 md->writeback += nr_pages;
f69ff943
SW		 2531
2532 if (PageAnon(page))
eb4866d0 2533 md->anon += nr_pages;
f69ff943
SW		 2534
2535 if (count > md->mapcount_max)
2536 md->mapcount_max = count;
2537
eb4866d0 2538 md->node[page_to_nid(page)] += nr_pages;
f69ff943
SW		 2539}
2540
3200a8aa
DH		 2541static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
2542 unsigned long addr)
2543{
2544 struct page *page;
2545 int nid;
2546
2547 if (!pte_present(pte))
2548 return NULL;
2549
2550 page = vm_normal_page(vma, addr, pte);
3218f871 2551 if (!page || is_zone_device_page(page))
3200a8aa
DH		 2552 return NULL;
2553
2554 if (PageReserved(page))
2555 return NULL;
2556
2557 nid = page_to_nid(page);
4ff1b2c2 2558 if (!node_isset(nid, node_states[N_MEMORY]))
3200a8aa
DH		 2559 return NULL;
2560
2561 return page;
2562}
2563
28093f9f
GS		 2564#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2565static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
2566 struct vm_area_struct *vma,
2567 unsigned long addr)
2568{
2569 struct page *page;
2570 int nid;
2571
2572 if (!pmd_present(pmd))
2573 return NULL;
2574
2575 page = vm_normal_page_pmd(vma, addr, pmd);
2576 if (!page)
2577 return NULL;
2578
2579 if (PageReserved(page))
2580 return NULL;
2581
2582 nid = page_to_nid(page);
2583 if (!node_isset(nid, node_states[N_MEMORY]))
2584 return NULL;
2585
2586 return page;
2587}
2588#endif
2589
f69ff943
SW		 2590static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
2591 unsigned long end, struct mm_walk *walk)
2592{
d85f4d6d
NH		 2593 struct numa_maps *md = walk->private;
2594 struct vm_area_struct *vma = walk->vma;
f69ff943
SW		 2595 spinlock_t *ptl;
2596 pte_t *orig_pte;
2597 pte_t *pte;
2598
28093f9f 2599#ifdef CONFIG_TRANSPARENT_HUGEPAGE
b6ec57f4
KS		 2600 ptl = pmd_trans_huge_lock(pmd, vma);
2601 if (ptl) {
025c5b24
NH		 2602 struct page *page;
2603
28093f9f 2604 page = can_gather_numa_stats_pmd(*pmd, vma, addr);
025c5b24 2605 if (page)
28093f9f 2606 gather_stats(page, md, pmd_dirty(*pmd),
025c5b24 2607 HPAGE_PMD_SIZE/PAGE_SIZE);
bf929152 2608 spin_unlock(ptl);
025c5b24 2609 return 0;
32ef4384 2610 }
28093f9f 2611#endif
f69ff943 2612 orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
7780d040
HD		 2613 if (!pte) {
2614 walk->action = ACTION_AGAIN;
2615 return 0;
2616 }
f69ff943 2617 do {
c33c7948
RR		 2618 pte_t ptent = ptep_get(pte);
2619 struct page *page = can_gather_numa_stats(ptent, vma, addr);
f69ff943
SW		 2620 if (!page)
2621 continue;
c33c7948 2622 gather_stats(page, md, pte_dirty(ptent), 1);
f69ff943
SW		 2623
2624 } while (pte++, addr += PAGE_SIZE, addr != end);
2625 pte_unmap_unlock(orig_pte, ptl);
a66c0410 2626 cond_resched();
f69ff943
SW		 2627 return 0;
2628}
2629#ifdef CONFIG_HUGETLB_PAGE
632fd60f 2630static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
f69ff943
SW		 2631 unsigned long addr, unsigned long end, struct mm_walk *walk)
2632{
5c2ff95e 2633 pte_t huge_pte = huge_ptep_get(pte);
f69ff943
SW		 2634 struct numa_maps *md;
2635 struct page *page;
2636
5c2ff95e 2637 if (!pte_present(huge_pte))
f69ff943
SW		 2638 return 0;
2639
5c2ff95e 2640 page = pte_page(huge_pte);
f69ff943
SW		 2641
2642 md = walk->private;
5c2ff95e 2643 gather_stats(page, md, pte_dirty(huge_pte), 1);
f69ff943
SW		 2644 return 0;
2645}
2646
2647#else
632fd60f 2648static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
f69ff943
SW		 2649 unsigned long addr, unsigned long end, struct mm_walk *walk)
2650{
2651 return 0;
2652}
2653#endif
2654
7b86ac33
CH		 2655static const struct mm_walk_ops show_numa_ops = {
2656 .hugetlb_entry = gather_hugetlb_stats,
2657 .pmd_entry = gather_pte_stats,
49b06385 2658 .walk_lock = PGWALK_RDLOCK,
7b86ac33
CH		 2659};
2660
f69ff943
SW		 2661/*
2662 * Display pages allocated per node and memory policy via /proc.
2663 */
871305bb 2664static int show_numa_map(struct seq_file *m, void *v)
f69ff943 2665{
5b52fc89
SW		 2666 struct numa_maps_private *numa_priv = m->private;
2667 struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
f69ff943 2668 struct vm_area_struct *vma = v;
5b52fc89 2669 struct numa_maps *md = &numa_priv->md;
f69ff943
SW		 2670 struct file *file = vma->vm_file;
2671 struct mm_struct *mm = vma->vm_mm;
948927ee 2672 char buffer[64];
ddc1a5cb
HD		 2673 struct mempolicy *pol;
2674 pgoff_t ilx;
948927ee 2675 int nid;
f69ff943
SW		 2676
2677 if (!mm)
2678 return 0;
2679
5b52fc89
SW		 2680 /* Ensure we start with an empty set of numa_maps statistics. */
2681 memset(md, 0, sizeof(*md));
f69ff943 2682
ddc1a5cb 2683 pol = __get_vma_policy(vma, vma->vm_start, &ilx);
498f2371
ON		 2684 if (pol) {
2685 mpol_to_str(buffer, sizeof(buffer), pol);
2686 mpol_cond_put(pol);
2687 } else {
2688 mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
2689 }
f69ff943
SW		 2690
2691 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
2692
2693 if (file) {
17c2b4ee 2694 seq_puts(m, " file=");
08582d67 2695 seq_path(m, file_user_path(file), "\n\t= ");
11250fd1 2696 } else if (vma_is_initial_heap(vma)) {
17c2b4ee 2697 seq_puts(m, " heap");
11250fd1 2698 } else if (vma_is_initial_stack(vma)) {
65376df5 2699 seq_puts(m, " stack");
f69ff943
SW		 2700 }
2701
fc360bd9 2702 if (is_vm_hugetlb_page(vma))
17c2b4ee 2703 seq_puts(m, " huge");
fc360bd9 2704
c1e8d7c6 2705 /* mmap_lock is held by m_start */
7b86ac33 2706 walk_page_vma(vma, &show_numa_ops, md);
f69ff943
SW		 2707
2708 if (!md->pages)
2709 goto out;
2710
2711 if (md->anon)
2712 seq_printf(m, " anon=%lu", md->anon);
2713
2714 if (md->dirty)
2715 seq_printf(m, " dirty=%lu", md->dirty);
2716
2717 if (md->pages != md->anon && md->pages != md->dirty)
2718 seq_printf(m, " mapped=%lu", md->pages);
2719
2720 if (md->mapcount_max > 1)
2721 seq_printf(m, " mapmax=%lu", md->mapcount_max);
2722
2723 if (md->swapcache)
2724 seq_printf(m, " swapcache=%lu", md->swapcache);
2725
2726 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2727 seq_printf(m, " active=%lu", md->active);
2728
2729 if (md->writeback)
2730 seq_printf(m, " writeback=%lu", md->writeback);
2731
948927ee
DR		 2732 for_each_node_state(nid, N_MEMORY)
2733 if (md->node[nid])
2734 seq_printf(m, " N%d=%lu", nid, md->node[nid]);
198d1597
RA		 2735
2736 seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
f69ff943
SW		 2737out:
2738 seq_putc(m, '\n');
f69ff943
SW		 2739 return 0;
2740}
5b52fc89 2741
03a44825 2742static const struct seq_operations proc_pid_numa_maps_op = {
b7643757
SP		 2743 .start = m_start,
2744 .next = m_next,
2745 .stop = m_stop,
871305bb 2746 .show = show_numa_map,
6e21c8f1 2747};
662795de 2748
b7643757
SP		 2749static int pid_numa_maps_open(struct inode *inode, struct file *file)
2750{
871305bb
VB		 2751 return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
2752 sizeof(struct numa_maps_private));
b7643757
SP		 2753}
2754
2755const struct file_operations proc_pid_numa_maps_operations = {
2756 .open = pid_numa_maps_open,
2757 .read = seq_read,
2758 .llseek = seq_lseek,
29a40ace 2759 .release = proc_map_release,
b7643757
SP		 2760};
2761
f69ff943 2762#endif /* CONFIG_NUMA */
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