mm: report the pagesize backing a VMA in /proc/pid/smaps
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / proc / task_mmu.c
CommitLineData
1da177e4
LT
1#include <linux/mm.h>
2#include <linux/hugetlb.h>
3#include <linux/mount.h>
4#include <linux/seq_file.h>
e070ad49 5#include <linux/highmem.h>
5096add8 6#include <linux/ptrace.h>
6e21c8f1
CL
7#include <linux/pagemap.h>
8#include <linux/mempolicy.h>
85863e47
MM
9#include <linux/swap.h>
10#include <linux/swapops.h>
e070ad49 11
1da177e4
LT
12#include <asm/elf.h>
13#include <asm/uaccess.h>
e070ad49 14#include <asm/tlbflush.h>
1da177e4
LT
15#include "internal.h"
16
df5f8314 17void task_mem(struct seq_file *m, struct mm_struct *mm)
1da177e4
LT
18{
19 unsigned long data, text, lib;
365e9c87
HD
20 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
21
22 /*
23 * Note: to minimize their overhead, mm maintains hiwater_vm and
24 * hiwater_rss only when about to *lower* total_vm or rss. Any
25 * collector of these hiwater stats must therefore get total_vm
26 * and rss too, which will usually be the higher. Barriers? not
27 * worth the effort, such snapshots can always be inconsistent.
28 */
29 hiwater_vm = total_vm = mm->total_vm;
30 if (hiwater_vm < mm->hiwater_vm)
31 hiwater_vm = mm->hiwater_vm;
32 hiwater_rss = total_rss = get_mm_rss(mm);
33 if (hiwater_rss < mm->hiwater_rss)
34 hiwater_rss = mm->hiwater_rss;
1da177e4
LT
35
36 data = mm->total_vm - mm->shared_vm - mm->stack_vm;
37 text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
38 lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
df5f8314 39 seq_printf(m,
365e9c87 40 "VmPeak:\t%8lu kB\n"
1da177e4
LT
41 "VmSize:\t%8lu kB\n"
42 "VmLck:\t%8lu kB\n"
365e9c87 43 "VmHWM:\t%8lu kB\n"
1da177e4
LT
44 "VmRSS:\t%8lu kB\n"
45 "VmData:\t%8lu kB\n"
46 "VmStk:\t%8lu kB\n"
47 "VmExe:\t%8lu kB\n"
48 "VmLib:\t%8lu kB\n"
49 "VmPTE:\t%8lu kB\n",
365e9c87
HD
50 hiwater_vm << (PAGE_SHIFT-10),
51 (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
1da177e4 52 mm->locked_vm << (PAGE_SHIFT-10),
365e9c87
HD
53 hiwater_rss << (PAGE_SHIFT-10),
54 total_rss << (PAGE_SHIFT-10),
1da177e4
LT
55 data << (PAGE_SHIFT-10),
56 mm->stack_vm << (PAGE_SHIFT-10), text, lib,
57 (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
1da177e4
LT
58}
59
60unsigned long task_vsize(struct mm_struct *mm)
61{
62 return PAGE_SIZE * mm->total_vm;
63}
64
65int task_statm(struct mm_struct *mm, int *shared, int *text,
66 int *data, int *resident)
67{
4294621f 68 *shared = get_mm_counter(mm, file_rss);
1da177e4
LT
69 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
70 >> PAGE_SHIFT;
71 *data = mm->total_vm - mm->shared_vm;
4294621f 72 *resident = *shared + get_mm_counter(mm, anon_rss);
1da177e4
LT
73 return mm->total_vm;
74}
75
1da177e4
LT
76static void pad_len_spaces(struct seq_file *m, int len)
77{
78 len = 25 + sizeof(void*) * 6 - len;
79 if (len < 1)
80 len = 1;
81 seq_printf(m, "%*c", len, ' ');
82}
83
a6198797
MM
84static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
85{
86 if (vma && vma != priv->tail_vma) {
87 struct mm_struct *mm = vma->vm_mm;
88 up_read(&mm->mmap_sem);
89 mmput(mm);
90 }
91}
ec4dd3eb 92
a6198797 93static void *m_start(struct seq_file *m, loff_t *pos)
e070ad49 94{
a6198797
MM
95 struct proc_maps_private *priv = m->private;
96 unsigned long last_addr = m->version;
97 struct mm_struct *mm;
98 struct vm_area_struct *vma, *tail_vma = NULL;
99 loff_t l = *pos;
100
101 /* Clear the per syscall fields in priv */
102 priv->task = NULL;
103 priv->tail_vma = NULL;
104
105 /*
106 * We remember last_addr rather than next_addr to hit with
107 * mmap_cache most of the time. We have zero last_addr at
108 * the beginning and also after lseek. We will have -1 last_addr
109 * after the end of the vmas.
110 */
111
112 if (last_addr == -1UL)
113 return NULL;
114
115 priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
116 if (!priv->task)
117 return NULL;
118
119 mm = mm_for_maps(priv->task);
120 if (!mm)
121 return NULL;
122
123 tail_vma = get_gate_vma(priv->task);
124 priv->tail_vma = tail_vma;
125
126 /* Start with last addr hint */
127 vma = find_vma(mm, last_addr);
128 if (last_addr && vma) {
129 vma = vma->vm_next;
130 goto out;
131 }
132
133 /*
134 * Check the vma index is within the range and do
135 * sequential scan until m_index.
136 */
137 vma = NULL;
138 if ((unsigned long)l < mm->map_count) {
139 vma = mm->mmap;
140 while (l-- && vma)
141 vma = vma->vm_next;
142 goto out;
143 }
144
145 if (l != mm->map_count)
146 tail_vma = NULL; /* After gate vma */
147
148out:
149 if (vma)
150 return vma;
151
152 /* End of vmas has been reached */
153 m->version = (tail_vma != NULL)? 0: -1UL;
154 up_read(&mm->mmap_sem);
155 mmput(mm);
156 return tail_vma;
157}
158
159static void *m_next(struct seq_file *m, void *v, loff_t *pos)
160{
161 struct proc_maps_private *priv = m->private;
162 struct vm_area_struct *vma = v;
163 struct vm_area_struct *tail_vma = priv->tail_vma;
164
165 (*pos)++;
166 if (vma && (vma != tail_vma) && vma->vm_next)
167 return vma->vm_next;
168 vma_stop(priv, vma);
169 return (vma != tail_vma)? tail_vma: NULL;
170}
171
172static void m_stop(struct seq_file *m, void *v)
173{
174 struct proc_maps_private *priv = m->private;
175 struct vm_area_struct *vma = v;
176
177 vma_stop(priv, vma);
178 if (priv->task)
179 put_task_struct(priv->task);
180}
181
182static int do_maps_open(struct inode *inode, struct file *file,
03a44825 183 const struct seq_operations *ops)
a6198797
MM
184{
185 struct proc_maps_private *priv;
186 int ret = -ENOMEM;
187 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
188 if (priv) {
189 priv->pid = proc_pid(inode);
190 ret = seq_open(file, ops);
191 if (!ret) {
192 struct seq_file *m = file->private_data;
193 m->private = priv;
194 } else {
195 kfree(priv);
196 }
197 }
198 return ret;
199}
e070ad49 200
7c88db0c 201static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
1da177e4 202{
e070ad49
ML
203 struct mm_struct *mm = vma->vm_mm;
204 struct file *file = vma->vm_file;
205 int flags = vma->vm_flags;
1da177e4
LT
206 unsigned long ino = 0;
207 dev_t dev = 0;
208 int len;
209
210 if (file) {
2fddfeef 211 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1da177e4
LT
212 dev = inode->i_sb->s_dev;
213 ino = inode->i_ino;
214 }
215
1804dc6e 216 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
e070ad49
ML
217 vma->vm_start,
218 vma->vm_end,
1da177e4
LT
219 flags & VM_READ ? 'r' : '-',
220 flags & VM_WRITE ? 'w' : '-',
221 flags & VM_EXEC ? 'x' : '-',
222 flags & VM_MAYSHARE ? 's' : 'p',
1804dc6e 223 ((loff_t)vma->vm_pgoff) << PAGE_SHIFT,
1da177e4
LT
224 MAJOR(dev), MINOR(dev), ino, &len);
225
226 /*
227 * Print the dentry name for named mappings, and a
228 * special [heap] marker for the heap:
229 */
e070ad49 230 if (file) {
1da177e4 231 pad_len_spaces(m, len);
c32c2f63 232 seq_path(m, &file->f_path, "\n");
1da177e4 233 } else {
e6e5494c
IM
234 const char *name = arch_vma_name(vma);
235 if (!name) {
236 if (mm) {
237 if (vma->vm_start <= mm->start_brk &&
e070ad49 238 vma->vm_end >= mm->brk) {
e6e5494c
IM
239 name = "[heap]";
240 } else if (vma->vm_start <= mm->start_stack &&
241 vma->vm_end >= mm->start_stack) {
242 name = "[stack]";
1da177e4 243 }
e6e5494c
IM
244 } else {
245 name = "[vdso]";
1da177e4 246 }
e6e5494c
IM
247 }
248 if (name) {
1da177e4 249 pad_len_spaces(m, len);
e6e5494c 250 seq_puts(m, name);
1da177e4
LT
251 }
252 }
253 seq_putc(m, '\n');
7c88db0c
JK
254}
255
256static int show_map(struct seq_file *m, void *v)
257{
258 struct vm_area_struct *vma = v;
259 struct proc_maps_private *priv = m->private;
260 struct task_struct *task = priv->task;
261
262 show_map_vma(m, vma);
e070ad49 263
e070ad49
ML
264 if (m->count < m->size) /* vma is copied successfully */
265 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
1da177e4
LT
266 return 0;
267}
268
03a44825 269static const struct seq_operations proc_pid_maps_op = {
a6198797
MM
270 .start = m_start,
271 .next = m_next,
272 .stop = m_stop,
273 .show = show_map
274};
275
276static int maps_open(struct inode *inode, struct file *file)
277{
278 return do_maps_open(inode, file, &proc_pid_maps_op);
279}
280
281const struct file_operations proc_maps_operations = {
282 .open = maps_open,
283 .read = seq_read,
284 .llseek = seq_lseek,
285 .release = seq_release_private,
286};
287
288/*
289 * Proportional Set Size(PSS): my share of RSS.
290 *
291 * PSS of a process is the count of pages it has in memory, where each
292 * page is divided by the number of processes sharing it. So if a
293 * process has 1000 pages all to itself, and 1000 shared with one other
294 * process, its PSS will be 1500.
295 *
296 * To keep (accumulated) division errors low, we adopt a 64bit
297 * fixed-point pss counter to minimize division errors. So (pss >>
298 * PSS_SHIFT) would be the real byte count.
299 *
300 * A shift of 12 before division means (assuming 4K page size):
301 * - 1M 3-user-pages add up to 8KB errors;
302 * - supports mapcount up to 2^24, or 16M;
303 * - supports PSS up to 2^52 bytes, or 4PB.
304 */
305#define PSS_SHIFT 12
306
1e883281 307#ifdef CONFIG_PROC_PAGE_MONITOR
214e471f 308struct mem_size_stats {
a6198797
MM
309 struct vm_area_struct *vma;
310 unsigned long resident;
311 unsigned long shared_clean;
312 unsigned long shared_dirty;
313 unsigned long private_clean;
314 unsigned long private_dirty;
315 unsigned long referenced;
214e471f 316 unsigned long swap;
a6198797
MM
317 u64 pss;
318};
319
b3ae5acb 320static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 321 struct mm_walk *walk)
e070ad49 322{
2165009b 323 struct mem_size_stats *mss = walk->private;
b3ae5acb 324 struct vm_area_struct *vma = mss->vma;
e070ad49 325 pte_t *pte, ptent;
705e87c0 326 spinlock_t *ptl;
e070ad49 327 struct page *page;
ec4dd3eb 328 int mapcount;
e070ad49 329
705e87c0 330 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
826fad1b 331 for (; addr != end; pte++, addr += PAGE_SIZE) {
e070ad49 332 ptent = *pte;
214e471f
PZ
333
334 if (is_swap_pte(ptent)) {
335 mss->swap += PAGE_SIZE;
336 continue;
337 }
338
705e87c0 339 if (!pte_present(ptent))
e070ad49
ML
340 continue;
341
342 mss->resident += PAGE_SIZE;
ad820c5d
NP
343
344 page = vm_normal_page(vma, addr, ptent);
345 if (!page)
e070ad49
ML
346 continue;
347
f79f177c
DR
348 /* Accumulate the size in pages that have been accessed. */
349 if (pte_young(ptent) || PageReferenced(page))
350 mss->referenced += PAGE_SIZE;
ec4dd3eb
FW
351 mapcount = page_mapcount(page);
352 if (mapcount >= 2) {
e070ad49
ML
353 if (pte_dirty(ptent))
354 mss->shared_dirty += PAGE_SIZE;
355 else
356 mss->shared_clean += PAGE_SIZE;
ec4dd3eb 357 mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
e070ad49
ML
358 } else {
359 if (pte_dirty(ptent))
360 mss->private_dirty += PAGE_SIZE;
361 else
362 mss->private_clean += PAGE_SIZE;
ec4dd3eb 363 mss->pss += (PAGE_SIZE << PSS_SHIFT);
e070ad49 364 }
826fad1b 365 }
705e87c0
HD
366 pte_unmap_unlock(pte - 1, ptl);
367 cond_resched();
b3ae5acb 368 return 0;
e070ad49
ML
369}
370
e070ad49
ML
371static int show_smap(struct seq_file *m, void *v)
372{
7c88db0c
JK
373 struct proc_maps_private *priv = m->private;
374 struct task_struct *task = priv->task;
e070ad49 375 struct vm_area_struct *vma = v;
e070ad49 376 struct mem_size_stats mss;
2165009b
DH
377 struct mm_walk smaps_walk = {
378 .pmd_entry = smaps_pte_range,
379 .mm = vma->vm_mm,
380 .private = &mss,
381 };
e070ad49
ML
382
383 memset(&mss, 0, sizeof mss);
b3ae5acb 384 mss.vma = vma;
5ddfae16 385 if (vma->vm_mm && !is_vm_hugetlb_page(vma))
2165009b 386 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
4752c369 387
7c88db0c 388 show_map_vma(m, vma);
4752c369
MM
389
390 seq_printf(m,
391 "Size: %8lu kB\n"
392 "Rss: %8lu kB\n"
393 "Pss: %8lu kB\n"
394 "Shared_Clean: %8lu kB\n"
395 "Shared_Dirty: %8lu kB\n"
396 "Private_Clean: %8lu kB\n"
397 "Private_Dirty: %8lu kB\n"
214e471f 398 "Referenced: %8lu kB\n"
08fba699
MG
399 "Swap: %8lu kB\n"
400 "KernelPageSize: %8lu kB\n",
4752c369
MM
401 (vma->vm_end - vma->vm_start) >> 10,
402 mss.resident >> 10,
403 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
404 mss.shared_clean >> 10,
405 mss.shared_dirty >> 10,
406 mss.private_clean >> 10,
407 mss.private_dirty >> 10,
214e471f 408 mss.referenced >> 10,
08fba699
MG
409 mss.swap >> 10,
410 vma_kernel_pagesize(vma) >> 10);
4752c369 411
7c88db0c
JK
412 if (m->count < m->size) /* vma is copied successfully */
413 m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
414 return 0;
e070ad49
ML
415}
416
03a44825 417static const struct seq_operations proc_pid_smaps_op = {
a6198797
MM
418 .start = m_start,
419 .next = m_next,
420 .stop = m_stop,
421 .show = show_smap
422};
423
424static int smaps_open(struct inode *inode, struct file *file)
425{
426 return do_maps_open(inode, file, &proc_pid_smaps_op);
427}
428
429const struct file_operations proc_smaps_operations = {
430 .open = smaps_open,
431 .read = seq_read,
432 .llseek = seq_lseek,
433 .release = seq_release_private,
434};
435
436static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
2165009b 437 unsigned long end, struct mm_walk *walk)
a6198797 438{
2165009b 439 struct vm_area_struct *vma = walk->private;
a6198797
MM
440 pte_t *pte, ptent;
441 spinlock_t *ptl;
442 struct page *page;
443
444 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
445 for (; addr != end; pte++, addr += PAGE_SIZE) {
446 ptent = *pte;
447 if (!pte_present(ptent))
448 continue;
449
450 page = vm_normal_page(vma, addr, ptent);
451 if (!page)
452 continue;
453
454 /* Clear accessed and referenced bits. */
455 ptep_test_and_clear_young(vma, addr, pte);
456 ClearPageReferenced(page);
457 }
458 pte_unmap_unlock(pte - 1, ptl);
459 cond_resched();
460 return 0;
461}
462
f248dcb3
MM
463static ssize_t clear_refs_write(struct file *file, const char __user *buf,
464 size_t count, loff_t *ppos)
b813e931 465{
f248dcb3
MM
466 struct task_struct *task;
467 char buffer[PROC_NUMBUF], *end;
468 struct mm_struct *mm;
b813e931
DR
469 struct vm_area_struct *vma;
470
f248dcb3
MM
471 memset(buffer, 0, sizeof(buffer));
472 if (count > sizeof(buffer) - 1)
473 count = sizeof(buffer) - 1;
474 if (copy_from_user(buffer, buf, count))
475 return -EFAULT;
476 if (!simple_strtol(buffer, &end, 0))
477 return -EINVAL;
478 if (*end == '\n')
479 end++;
480 task = get_proc_task(file->f_path.dentry->d_inode);
481 if (!task)
482 return -ESRCH;
483 mm = get_task_mm(task);
484 if (mm) {
20cbc972
AM
485 struct mm_walk clear_refs_walk = {
486 .pmd_entry = clear_refs_pte_range,
487 .mm = mm,
488 };
f248dcb3 489 down_read(&mm->mmap_sem);
2165009b
DH
490 for (vma = mm->mmap; vma; vma = vma->vm_next) {
491 clear_refs_walk.private = vma;
f248dcb3 492 if (!is_vm_hugetlb_page(vma))
2165009b
DH
493 walk_page_range(vma->vm_start, vma->vm_end,
494 &clear_refs_walk);
495 }
f248dcb3
MM
496 flush_tlb_mm(mm);
497 up_read(&mm->mmap_sem);
498 mmput(mm);
499 }
500 put_task_struct(task);
501 if (end - buffer == 0)
502 return -EIO;
503 return end - buffer;
b813e931
DR
504}
505
f248dcb3
MM
506const struct file_operations proc_clear_refs_operations = {
507 .write = clear_refs_write,
508};
509
85863e47 510struct pagemapread {
aae8679b 511 u64 __user *out, *end;
85863e47
MM
512};
513
f16278c6
HR
514#define PM_ENTRY_BYTES sizeof(u64)
515#define PM_STATUS_BITS 3
516#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
517#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
518#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
519#define PM_PSHIFT_BITS 6
520#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
521#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
522#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
523#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
524#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
525
526#define PM_PRESENT PM_STATUS(4LL)
527#define PM_SWAP PM_STATUS(2LL)
528#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
85863e47
MM
529#define PM_END_OF_BUFFER 1
530
531static int add_to_pagemap(unsigned long addr, u64 pfn,
532 struct pagemapread *pm)
533{
85863e47
MM
534 if (put_user(pfn, pm->out))
535 return -EFAULT;
aae8679b
TT
536 pm->out++;
537 if (pm->out >= pm->end)
538 return PM_END_OF_BUFFER;
85863e47
MM
539 return 0;
540}
541
542static int pagemap_pte_hole(unsigned long start, unsigned long end,
2165009b 543 struct mm_walk *walk)
85863e47 544{
2165009b 545 struct pagemapread *pm = walk->private;
85863e47
MM
546 unsigned long addr;
547 int err = 0;
548 for (addr = start; addr < end; addr += PAGE_SIZE) {
549 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
550 if (err)
551 break;
552 }
553 return err;
554}
555
9d02dbc8 556static u64 swap_pte_to_pagemap_entry(pte_t pte)
85863e47
MM
557{
558 swp_entry_t e = pte_to_swp_entry(pte);
f16278c6 559 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
85863e47
MM
560}
561
49c50342 562static u64 pte_to_pagemap_entry(pte_t pte)
bcf8039e 563{
49c50342 564 u64 pme = 0;
bcf8039e
DH
565 if (is_swap_pte(pte))
566 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
567 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
568 else if (pte_present(pte))
569 pme = PM_PFRAME(pte_pfn(pte))
570 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
571 return pme;
572}
573
85863e47 574static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 575 struct mm_walk *walk)
85863e47 576{
bcf8039e 577 struct vm_area_struct *vma;
2165009b 578 struct pagemapread *pm = walk->private;
85863e47
MM
579 pte_t *pte;
580 int err = 0;
581
bcf8039e
DH
582 /* find the first VMA at or above 'addr' */
583 vma = find_vma(walk->mm, addr);
85863e47
MM
584 for (; addr != end; addr += PAGE_SIZE) {
585 u64 pfn = PM_NOT_PRESENT;
bcf8039e
DH
586
587 /* check to see if we've left 'vma' behind
588 * and need a new, higher one */
589 if (vma && (addr >= vma->vm_end))
590 vma = find_vma(walk->mm, addr);
591
592 /* check that 'vma' actually covers this address,
593 * and that it isn't a huge page vma */
594 if (vma && (vma->vm_start <= addr) &&
595 !is_vm_hugetlb_page(vma)) {
596 pte = pte_offset_map(pmd, addr);
597 pfn = pte_to_pagemap_entry(*pte);
598 /* unmap before userspace copy */
599 pte_unmap(pte);
600 }
85863e47
MM
601 err = add_to_pagemap(addr, pfn, pm);
602 if (err)
603 return err;
604 }
605
606 cond_resched();
607
608 return err;
609}
610
85863e47
MM
611/*
612 * /proc/pid/pagemap - an array mapping virtual pages to pfns
613 *
f16278c6
HR
614 * For each page in the address space, this file contains one 64-bit entry
615 * consisting of the following:
616 *
617 * Bits 0-55 page frame number (PFN) if present
618 * Bits 0-4 swap type if swapped
619 * Bits 5-55 swap offset if swapped
620 * Bits 55-60 page shift (page size = 1<<page shift)
621 * Bit 61 reserved for future use
622 * Bit 62 page swapped
623 * Bit 63 page present
624 *
625 * If the page is not present but in swap, then the PFN contains an
626 * encoding of the swap file number and the page's offset into the
627 * swap. Unmapped pages return a null PFN. This allows determining
85863e47
MM
628 * precisely which pages are mapped (or in swap) and comparing mapped
629 * pages between processes.
630 *
631 * Efficient users of this interface will use /proc/pid/maps to
632 * determine which areas of memory are actually mapped and llseek to
633 * skip over unmapped regions.
634 */
635static ssize_t pagemap_read(struct file *file, char __user *buf,
636 size_t count, loff_t *ppos)
637{
638 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
639 struct page **pages, *page;
640 unsigned long uaddr, uend;
641 struct mm_struct *mm;
642 struct pagemapread pm;
643 int pagecount;
644 int ret = -ESRCH;
ee1e6ab6 645 struct mm_walk pagemap_walk = {};
5d7e0d2b
AM
646 unsigned long src;
647 unsigned long svpfn;
648 unsigned long start_vaddr;
649 unsigned long end_vaddr;
85863e47
MM
650
651 if (!task)
652 goto out;
653
654 ret = -EACCES;
006ebb40 655 if (!ptrace_may_access(task, PTRACE_MODE_READ))
fb39380b 656 goto out_task;
85863e47
MM
657
658 ret = -EINVAL;
659 /* file position must be aligned */
aae8679b 660 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
fb39380b 661 goto out_task;
85863e47
MM
662
663 ret = 0;
664 mm = get_task_mm(task);
665 if (!mm)
fb39380b 666 goto out_task;
85863e47 667
5d7e0d2b 668
85863e47
MM
669 uaddr = (unsigned long)buf & PAGE_MASK;
670 uend = (unsigned long)(buf + count);
671 pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE;
5d7e0d2b
AM
672 ret = 0;
673 if (pagecount == 0)
674 goto out_mm;
675 pages = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
676 ret = -ENOMEM;
85863e47 677 if (!pages)
fb39380b 678 goto out_mm;
85863e47
MM
679
680 down_read(&current->mm->mmap_sem);
681 ret = get_user_pages(current, current->mm, uaddr, pagecount,
682 1, 0, pages, NULL);
683 up_read(&current->mm->mmap_sem);
684
685 if (ret < 0)
686 goto out_free;
687
fb39380b
MT
688 if (ret != pagecount) {
689 pagecount = ret;
690 ret = -EFAULT;
691 goto out_pages;
692 }
693
aae8679b
TT
694 pm.out = (u64 *)buf;
695 pm.end = (u64 *)(buf + count);
85863e47 696
5d7e0d2b
AM
697 pagemap_walk.pmd_entry = pagemap_pte_range;
698 pagemap_walk.pte_hole = pagemap_pte_hole;
699 pagemap_walk.mm = mm;
700 pagemap_walk.private = &pm;
701
702 src = *ppos;
703 svpfn = src / PM_ENTRY_BYTES;
704 start_vaddr = svpfn << PAGE_SHIFT;
705 end_vaddr = TASK_SIZE_OF(task);
706
707 /* watch out for wraparound */
708 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
709 start_vaddr = end_vaddr;
710
711 /*
712 * The odds are that this will stop walking way
713 * before end_vaddr, because the length of the
714 * user buffer is tracked in "pm", and the walk
715 * will stop when we hit the end of the buffer.
716 */
717 ret = walk_page_range(start_vaddr, end_vaddr, &pagemap_walk);
718 if (ret == PM_END_OF_BUFFER)
719 ret = 0;
720 /* don't need mmap_sem for these, but this looks cleaner */
721 *ppos += (char *)pm.out - buf;
722 if (!ret)
723 ret = (char *)pm.out - buf;
85863e47 724
fb39380b 725out_pages:
85863e47
MM
726 for (; pagecount; pagecount--) {
727 page = pages[pagecount-1];
728 if (!PageReserved(page))
729 SetPageDirty(page);
730 page_cache_release(page);
731 }
85863e47
MM
732out_free:
733 kfree(pages);
fb39380b
MT
734out_mm:
735 mmput(mm);
85863e47
MM
736out_task:
737 put_task_struct(task);
738out:
739 return ret;
740}
741
742const struct file_operations proc_pagemap_operations = {
743 .llseek = mem_lseek, /* borrow this */
744 .read = pagemap_read,
745};
1e883281 746#endif /* CONFIG_PROC_PAGE_MONITOR */
85863e47 747
6e21c8f1 748#ifdef CONFIG_NUMA
1a75a6c8 749extern int show_numa_map(struct seq_file *m, void *v);
6e21c8f1 750
03a44825 751static const struct seq_operations proc_pid_numa_maps_op = {
1a75a6c8
CL
752 .start = m_start,
753 .next = m_next,
754 .stop = m_stop,
3bbfe059 755 .show = show_numa_map,
6e21c8f1 756};
662795de
EB
757
758static int numa_maps_open(struct inode *inode, struct file *file)
759{
760 return do_maps_open(inode, file, &proc_pid_numa_maps_op);
761}
762
00977a59 763const struct file_operations proc_numa_maps_operations = {
662795de
EB
764 .open = numa_maps_open,
765 .read = seq_read,
766 .llseek = seq_lseek,
99f89551 767 .release = seq_release_private,
662795de 768};
6e21c8f1 769#endif