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mm_for_maps: simplify, use ptrace_may_access()
[net-next-2.6.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 206 unsigned long ino = 0;
6260a4b0 207 unsigned long long pgoff = 0;
1da177e4
LT
208 dev_t dev = 0;
209 int len;
210
211 if (file) {
2fddfeef 212 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1da177e4
LT
213 dev = inode->i_sb->s_dev;
214 ino = inode->i_ino;
6260a4b0 215 pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
1da177e4
LT
216 }
217
1804dc6e 218 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
e070ad49
ML
219 vma->vm_start,
220 vma->vm_end,
1da177e4
LT
221 flags & VM_READ ? 'r' : '-',
222 flags & VM_WRITE ? 'w' : '-',
223 flags & VM_EXEC ? 'x' : '-',
224 flags & VM_MAYSHARE ? 's' : 'p',
6260a4b0 225 pgoff,
1da177e4
LT
226 MAJOR(dev), MINOR(dev), ino, &len);
227
228 /*
229 * Print the dentry name for named mappings, and a
230 * special [heap] marker for the heap:
231 */
e070ad49 232 if (file) {
1da177e4 233 pad_len_spaces(m, len);
c32c2f63 234 seq_path(m, &file->f_path, "\n");
1da177e4 235 } else {
e6e5494c
IM
236 const char *name = arch_vma_name(vma);
237 if (!name) {
238 if (mm) {
239 if (vma->vm_start <= mm->start_brk &&
e070ad49 240 vma->vm_end >= mm->brk) {
e6e5494c
IM
241 name = "[heap]";
242 } else if (vma->vm_start <= mm->start_stack &&
243 vma->vm_end >= mm->start_stack) {
244 name = "[stack]";
1da177e4 245 }
e6e5494c
IM
246 } else {
247 name = "[vdso]";
1da177e4 248 }
e6e5494c
IM
249 }
250 if (name) {
1da177e4 251 pad_len_spaces(m, len);
e6e5494c 252 seq_puts(m, name);
1da177e4
LT
253 }
254 }
255 seq_putc(m, '\n');
7c88db0c
JK
256}
257
258static int show_map(struct seq_file *m, void *v)
259{
260 struct vm_area_struct *vma = v;
261 struct proc_maps_private *priv = m->private;
262 struct task_struct *task = priv->task;
263
264 show_map_vma(m, vma);
e070ad49 265
e070ad49
ML
266 if (m->count < m->size) /* vma is copied successfully */
267 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
1da177e4
LT
268 return 0;
269}
270
03a44825 271static const struct seq_operations proc_pid_maps_op = {
a6198797
MM
272 .start = m_start,
273 .next = m_next,
274 .stop = m_stop,
275 .show = show_map
276};
277
278static int maps_open(struct inode *inode, struct file *file)
279{
280 return do_maps_open(inode, file, &proc_pid_maps_op);
281}
282
283const struct file_operations proc_maps_operations = {
284 .open = maps_open,
285 .read = seq_read,
286 .llseek = seq_lseek,
287 .release = seq_release_private,
288};
289
290/*
291 * Proportional Set Size(PSS): my share of RSS.
292 *
293 * PSS of a process is the count of pages it has in memory, where each
294 * page is divided by the number of processes sharing it. So if a
295 * process has 1000 pages all to itself, and 1000 shared with one other
296 * process, its PSS will be 1500.
297 *
298 * To keep (accumulated) division errors low, we adopt a 64bit
299 * fixed-point pss counter to minimize division errors. So (pss >>
300 * PSS_SHIFT) would be the real byte count.
301 *
302 * A shift of 12 before division means (assuming 4K page size):
303 * - 1M 3-user-pages add up to 8KB errors;
304 * - supports mapcount up to 2^24, or 16M;
305 * - supports PSS up to 2^52 bytes, or 4PB.
306 */
307#define PSS_SHIFT 12
308
1e883281 309#ifdef CONFIG_PROC_PAGE_MONITOR
214e471f 310struct mem_size_stats {
a6198797
MM
311 struct vm_area_struct *vma;
312 unsigned long resident;
313 unsigned long shared_clean;
314 unsigned long shared_dirty;
315 unsigned long private_clean;
316 unsigned long private_dirty;
317 unsigned long referenced;
214e471f 318 unsigned long swap;
a6198797
MM
319 u64 pss;
320};
321
b3ae5acb 322static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 323 struct mm_walk *walk)
e070ad49 324{
2165009b 325 struct mem_size_stats *mss = walk->private;
b3ae5acb 326 struct vm_area_struct *vma = mss->vma;
e070ad49 327 pte_t *pte, ptent;
705e87c0 328 spinlock_t *ptl;
e070ad49 329 struct page *page;
ec4dd3eb 330 int mapcount;
e070ad49 331
705e87c0 332 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
826fad1b 333 for (; addr != end; pte++, addr += PAGE_SIZE) {
e070ad49 334 ptent = *pte;
214e471f
PZ
335
336 if (is_swap_pte(ptent)) {
337 mss->swap += PAGE_SIZE;
338 continue;
339 }
340
705e87c0 341 if (!pte_present(ptent))
e070ad49
ML
342 continue;
343
344 mss->resident += PAGE_SIZE;
ad820c5d
NP
345
346 page = vm_normal_page(vma, addr, ptent);
347 if (!page)
e070ad49
ML
348 continue;
349
f79f177c
DR
350 /* Accumulate the size in pages that have been accessed. */
351 if (pte_young(ptent) || PageReferenced(page))
352 mss->referenced += PAGE_SIZE;
ec4dd3eb
FW
353 mapcount = page_mapcount(page);
354 if (mapcount >= 2) {
e070ad49
ML
355 if (pte_dirty(ptent))
356 mss->shared_dirty += PAGE_SIZE;
357 else
358 mss->shared_clean += PAGE_SIZE;
ec4dd3eb 359 mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
e070ad49
ML
360 } else {
361 if (pte_dirty(ptent))
362 mss->private_dirty += PAGE_SIZE;
363 else
364 mss->private_clean += PAGE_SIZE;
ec4dd3eb 365 mss->pss += (PAGE_SIZE << PSS_SHIFT);
e070ad49 366 }
826fad1b 367 }
705e87c0
HD
368 pte_unmap_unlock(pte - 1, ptl);
369 cond_resched();
b3ae5acb 370 return 0;
e070ad49
ML
371}
372
e070ad49
ML
373static int show_smap(struct seq_file *m, void *v)
374{
7c88db0c
JK
375 struct proc_maps_private *priv = m->private;
376 struct task_struct *task = priv->task;
e070ad49 377 struct vm_area_struct *vma = v;
e070ad49 378 struct mem_size_stats mss;
2165009b
DH
379 struct mm_walk smaps_walk = {
380 .pmd_entry = smaps_pte_range,
381 .mm = vma->vm_mm,
382 .private = &mss,
383 };
e070ad49
ML
384
385 memset(&mss, 0, sizeof mss);
b3ae5acb 386 mss.vma = vma;
5ddfae16 387 if (vma->vm_mm && !is_vm_hugetlb_page(vma))
2165009b 388 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
4752c369 389
7c88db0c 390 show_map_vma(m, vma);
4752c369
MM
391
392 seq_printf(m,
393 "Size: %8lu kB\n"
394 "Rss: %8lu kB\n"
395 "Pss: %8lu kB\n"
396 "Shared_Clean: %8lu kB\n"
397 "Shared_Dirty: %8lu kB\n"
398 "Private_Clean: %8lu kB\n"
399 "Private_Dirty: %8lu kB\n"
214e471f 400 "Referenced: %8lu kB\n"
08fba699 401 "Swap: %8lu kB\n"
3340289d
MG
402 "KernelPageSize: %8lu kB\n"
403 "MMUPageSize: %8lu kB\n",
4752c369
MM
404 (vma->vm_end - vma->vm_start) >> 10,
405 mss.resident >> 10,
406 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
407 mss.shared_clean >> 10,
408 mss.shared_dirty >> 10,
409 mss.private_clean >> 10,
410 mss.private_dirty >> 10,
214e471f 411 mss.referenced >> 10,
08fba699 412 mss.swap >> 10,
3340289d
MG
413 vma_kernel_pagesize(vma) >> 10,
414 vma_mmu_pagesize(vma) >> 10);
4752c369 415
7c88db0c
JK
416 if (m->count < m->size) /* vma is copied successfully */
417 m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
418 return 0;
e070ad49
ML
419}
420
03a44825 421static const struct seq_operations proc_pid_smaps_op = {
a6198797
MM
422 .start = m_start,
423 .next = m_next,
424 .stop = m_stop,
425 .show = show_smap
426};
427
428static int smaps_open(struct inode *inode, struct file *file)
429{
430 return do_maps_open(inode, file, &proc_pid_smaps_op);
431}
432
433const struct file_operations proc_smaps_operations = {
434 .open = smaps_open,
435 .read = seq_read,
436 .llseek = seq_lseek,
437 .release = seq_release_private,
438};
439
440static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
2165009b 441 unsigned long end, struct mm_walk *walk)
a6198797 442{
2165009b 443 struct vm_area_struct *vma = walk->private;
a6198797
MM
444 pte_t *pte, ptent;
445 spinlock_t *ptl;
446 struct page *page;
447
448 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
449 for (; addr != end; pte++, addr += PAGE_SIZE) {
450 ptent = *pte;
451 if (!pte_present(ptent))
452 continue;
453
454 page = vm_normal_page(vma, addr, ptent);
455 if (!page)
456 continue;
457
458 /* Clear accessed and referenced bits. */
459 ptep_test_and_clear_young(vma, addr, pte);
460 ClearPageReferenced(page);
461 }
462 pte_unmap_unlock(pte - 1, ptl);
463 cond_resched();
464 return 0;
465}
466
f248dcb3
MM
467static ssize_t clear_refs_write(struct file *file, const char __user *buf,
468 size_t count, loff_t *ppos)
b813e931 469{
f248dcb3
MM
470 struct task_struct *task;
471 char buffer[PROC_NUMBUF], *end;
472 struct mm_struct *mm;
b813e931
DR
473 struct vm_area_struct *vma;
474
f248dcb3
MM
475 memset(buffer, 0, sizeof(buffer));
476 if (count > sizeof(buffer) - 1)
477 count = sizeof(buffer) - 1;
478 if (copy_from_user(buffer, buf, count))
479 return -EFAULT;
480 if (!simple_strtol(buffer, &end, 0))
481 return -EINVAL;
482 if (*end == '\n')
483 end++;
484 task = get_proc_task(file->f_path.dentry->d_inode);
485 if (!task)
486 return -ESRCH;
487 mm = get_task_mm(task);
488 if (mm) {
20cbc972
AM
489 struct mm_walk clear_refs_walk = {
490 .pmd_entry = clear_refs_pte_range,
491 .mm = mm,
492 };
f248dcb3 493 down_read(&mm->mmap_sem);
2165009b
DH
494 for (vma = mm->mmap; vma; vma = vma->vm_next) {
495 clear_refs_walk.private = vma;
f248dcb3 496 if (!is_vm_hugetlb_page(vma))
2165009b
DH
497 walk_page_range(vma->vm_start, vma->vm_end,
498 &clear_refs_walk);
499 }
f248dcb3
MM
500 flush_tlb_mm(mm);
501 up_read(&mm->mmap_sem);
502 mmput(mm);
503 }
504 put_task_struct(task);
505 if (end - buffer == 0)
506 return -EIO;
507 return end - buffer;
b813e931
DR
508}
509
f248dcb3
MM
510const struct file_operations proc_clear_refs_operations = {
511 .write = clear_refs_write,
512};
513
85863e47 514struct pagemapread {
aae8679b 515 u64 __user *out, *end;
85863e47
MM
516};
517
f16278c6
HR
518#define PM_ENTRY_BYTES sizeof(u64)
519#define PM_STATUS_BITS 3
520#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
521#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
522#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
523#define PM_PSHIFT_BITS 6
524#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
525#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
526#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
527#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
528#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
529
530#define PM_PRESENT PM_STATUS(4LL)
531#define PM_SWAP PM_STATUS(2LL)
532#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
85863e47
MM
533#define PM_END_OF_BUFFER 1
534
535static int add_to_pagemap(unsigned long addr, u64 pfn,
536 struct pagemapread *pm)
537{
85863e47
MM
538 if (put_user(pfn, pm->out))
539 return -EFAULT;
aae8679b
TT
540 pm->out++;
541 if (pm->out >= pm->end)
542 return PM_END_OF_BUFFER;
85863e47
MM
543 return 0;
544}
545
546static int pagemap_pte_hole(unsigned long start, unsigned long end,
2165009b 547 struct mm_walk *walk)
85863e47 548{
2165009b 549 struct pagemapread *pm = walk->private;
85863e47
MM
550 unsigned long addr;
551 int err = 0;
552 for (addr = start; addr < end; addr += PAGE_SIZE) {
553 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
554 if (err)
555 break;
556 }
557 return err;
558}
559
9d02dbc8 560static u64 swap_pte_to_pagemap_entry(pte_t pte)
85863e47
MM
561{
562 swp_entry_t e = pte_to_swp_entry(pte);
f16278c6 563 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
85863e47
MM
564}
565
49c50342 566static u64 pte_to_pagemap_entry(pte_t pte)
bcf8039e 567{
49c50342 568 u64 pme = 0;
bcf8039e
DH
569 if (is_swap_pte(pte))
570 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
571 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
572 else if (pte_present(pte))
573 pme = PM_PFRAME(pte_pfn(pte))
574 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
575 return pme;
576}
577
85863e47 578static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 579 struct mm_walk *walk)
85863e47 580{
bcf8039e 581 struct vm_area_struct *vma;
2165009b 582 struct pagemapread *pm = walk->private;
85863e47
MM
583 pte_t *pte;
584 int err = 0;
585
bcf8039e
DH
586 /* find the first VMA at or above 'addr' */
587 vma = find_vma(walk->mm, addr);
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MM
588 for (; addr != end; addr += PAGE_SIZE) {
589 u64 pfn = PM_NOT_PRESENT;
bcf8039e
DH
590
591 /* check to see if we've left 'vma' behind
592 * and need a new, higher one */
593 if (vma && (addr >= vma->vm_end))
594 vma = find_vma(walk->mm, addr);
595
596 /* check that 'vma' actually covers this address,
597 * and that it isn't a huge page vma */
598 if (vma && (vma->vm_start <= addr) &&
599 !is_vm_hugetlb_page(vma)) {
600 pte = pte_offset_map(pmd, addr);
601 pfn = pte_to_pagemap_entry(*pte);
602 /* unmap before userspace copy */
603 pte_unmap(pte);
604 }
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MM
605 err = add_to_pagemap(addr, pfn, pm);
606 if (err)
607 return err;
608 }
609
610 cond_resched();
611
612 return err;
613}
614
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MM
615/*
616 * /proc/pid/pagemap - an array mapping virtual pages to pfns
617 *
f16278c6
HR
618 * For each page in the address space, this file contains one 64-bit entry
619 * consisting of the following:
620 *
621 * Bits 0-55 page frame number (PFN) if present
622 * Bits 0-4 swap type if swapped
623 * Bits 5-55 swap offset if swapped
624 * Bits 55-60 page shift (page size = 1<<page shift)
625 * Bit 61 reserved for future use
626 * Bit 62 page swapped
627 * Bit 63 page present
628 *
629 * If the page is not present but in swap, then the PFN contains an
630 * encoding of the swap file number and the page's offset into the
631 * swap. Unmapped pages return a null PFN. This allows determining
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MM
632 * precisely which pages are mapped (or in swap) and comparing mapped
633 * pages between processes.
634 *
635 * Efficient users of this interface will use /proc/pid/maps to
636 * determine which areas of memory are actually mapped and llseek to
637 * skip over unmapped regions.
638 */
639static ssize_t pagemap_read(struct file *file, char __user *buf,
640 size_t count, loff_t *ppos)
641{
642 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
643 struct page **pages, *page;
644 unsigned long uaddr, uend;
645 struct mm_struct *mm;
646 struct pagemapread pm;
647 int pagecount;
648 int ret = -ESRCH;
ee1e6ab6 649 struct mm_walk pagemap_walk = {};
5d7e0d2b
AM
650 unsigned long src;
651 unsigned long svpfn;
652 unsigned long start_vaddr;
653 unsigned long end_vaddr;
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MM
654
655 if (!task)
656 goto out;
657
658 ret = -EACCES;
006ebb40 659 if (!ptrace_may_access(task, PTRACE_MODE_READ))
fb39380b 660 goto out_task;
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MM
661
662 ret = -EINVAL;
663 /* file position must be aligned */
aae8679b 664 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
fb39380b 665 goto out_task;
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MM
666
667 ret = 0;
08161786
VM
668
669 if (!count)
670 goto out_task;
671
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MM
672 mm = get_task_mm(task);
673 if (!mm)
fb39380b 674 goto out_task;
85863e47 675
5d7e0d2b 676
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MM
677 uaddr = (unsigned long)buf & PAGE_MASK;
678 uend = (unsigned long)(buf + count);
679 pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE;
5d7e0d2b
AM
680 ret = 0;
681 if (pagecount == 0)
682 goto out_mm;
683 pages = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
684 ret = -ENOMEM;
85863e47 685 if (!pages)
fb39380b 686 goto out_mm;
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MM
687
688 down_read(&current->mm->mmap_sem);
689 ret = get_user_pages(current, current->mm, uaddr, pagecount,
690 1, 0, pages, NULL);
691 up_read(&current->mm->mmap_sem);
692
693 if (ret < 0)
694 goto out_free;
695
fb39380b
MT
696 if (ret != pagecount) {
697 pagecount = ret;
698 ret = -EFAULT;
699 goto out_pages;
700 }
701
09729a99
MAC
702 pm.out = (u64 __user *)buf;
703 pm.end = (u64 __user *)(buf + count);
85863e47 704
5d7e0d2b
AM
705 pagemap_walk.pmd_entry = pagemap_pte_range;
706 pagemap_walk.pte_hole = pagemap_pte_hole;
707 pagemap_walk.mm = mm;
708 pagemap_walk.private = &pm;
709
710 src = *ppos;
711 svpfn = src / PM_ENTRY_BYTES;
712 start_vaddr = svpfn << PAGE_SHIFT;
713 end_vaddr = TASK_SIZE_OF(task);
714
715 /* watch out for wraparound */
716 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
717 start_vaddr = end_vaddr;
718
719 /*
720 * The odds are that this will stop walking way
721 * before end_vaddr, because the length of the
722 * user buffer is tracked in "pm", and the walk
723 * will stop when we hit the end of the buffer.
724 */
725 ret = walk_page_range(start_vaddr, end_vaddr, &pagemap_walk);
726 if (ret == PM_END_OF_BUFFER)
727 ret = 0;
728 /* don't need mmap_sem for these, but this looks cleaner */
09729a99 729 *ppos += (char __user *)pm.out - buf;
5d7e0d2b 730 if (!ret)
09729a99 731 ret = (char __user *)pm.out - buf;
85863e47 732
fb39380b 733out_pages:
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MM
734 for (; pagecount; pagecount--) {
735 page = pages[pagecount-1];
736 if (!PageReserved(page))
737 SetPageDirty(page);
738 page_cache_release(page);
739 }
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MM
740out_free:
741 kfree(pages);
fb39380b
MT
742out_mm:
743 mmput(mm);
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MM
744out_task:
745 put_task_struct(task);
746out:
747 return ret;
748}
749
750const struct file_operations proc_pagemap_operations = {
751 .llseek = mem_lseek, /* borrow this */
752 .read = pagemap_read,
753};
1e883281 754#endif /* CONFIG_PROC_PAGE_MONITOR */
85863e47 755
6e21c8f1 756#ifdef CONFIG_NUMA
1a75a6c8 757extern int show_numa_map(struct seq_file *m, void *v);
6e21c8f1 758
03a44825 759static const struct seq_operations proc_pid_numa_maps_op = {
1a75a6c8
CL
760 .start = m_start,
761 .next = m_next,
762 .stop = m_stop,
3bbfe059 763 .show = show_numa_map,
6e21c8f1 764};
662795de
EB
765
766static int numa_maps_open(struct inode *inode, struct file *file)
767{
768 return do_maps_open(inode, file, &proc_pid_numa_maps_op);
769}
770
00977a59 771const struct file_operations proc_numa_maps_operations = {
662795de
EB
772 .open = numa_maps_open,
773 .read = seq_read,
774 .llseek = seq_lseek,
99f89551 775 .release = seq_release_private,
662795de 776};
6e21c8f1 777#endif