x86: use dyn_array in io_apic_xx.c
[deliverable/linux.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
4752c369 201static int show_map(struct seq_file *m, void *v)
1da177e4 202{
99f89551
EB
203 struct proc_maps_private *priv = m->private;
204 struct task_struct *task = priv->task;
e070ad49
ML
205 struct vm_area_struct *vma = v;
206 struct mm_struct *mm = vma->vm_mm;
207 struct file *file = vma->vm_file;
208 int flags = vma->vm_flags;
1da177e4
LT
209 unsigned long ino = 0;
210 dev_t dev = 0;
211 int len;
212
213 if (file) {
2fddfeef 214 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1da177e4
LT
215 dev = inode->i_sb->s_dev;
216 ino = inode->i_ino;
217 }
218
1804dc6e 219 seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
e070ad49
ML
220 vma->vm_start,
221 vma->vm_end,
1da177e4
LT
222 flags & VM_READ ? 'r' : '-',
223 flags & VM_WRITE ? 'w' : '-',
224 flags & VM_EXEC ? 'x' : '-',
225 flags & VM_MAYSHARE ? 's' : 'p',
1804dc6e 226 ((loff_t)vma->vm_pgoff) << PAGE_SHIFT,
1da177e4
LT
227 MAJOR(dev), MINOR(dev), ino, &len);
228
229 /*
230 * Print the dentry name for named mappings, and a
231 * special [heap] marker for the heap:
232 */
e070ad49 233 if (file) {
1da177e4 234 pad_len_spaces(m, len);
c32c2f63 235 seq_path(m, &file->f_path, "\n");
1da177e4 236 } else {
e6e5494c
IM
237 const char *name = arch_vma_name(vma);
238 if (!name) {
239 if (mm) {
240 if (vma->vm_start <= mm->start_brk &&
e070ad49 241 vma->vm_end >= mm->brk) {
e6e5494c
IM
242 name = "[heap]";
243 } else if (vma->vm_start <= mm->start_stack &&
244 vma->vm_end >= mm->start_stack) {
245 name = "[stack]";
1da177e4 246 }
e6e5494c
IM
247 } else {
248 name = "[vdso]";
1da177e4 249 }
e6e5494c
IM
250 }
251 if (name) {
1da177e4 252 pad_len_spaces(m, len);
e6e5494c 253 seq_puts(m, name);
1da177e4
LT
254 }
255 }
256 seq_putc(m, '\n');
e070ad49 257
e070ad49
ML
258 if (m->count < m->size) /* vma is copied successfully */
259 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
1da177e4
LT
260 return 0;
261}
262
03a44825 263static const struct seq_operations proc_pid_maps_op = {
a6198797
MM
264 .start = m_start,
265 .next = m_next,
266 .stop = m_stop,
267 .show = show_map
268};
269
270static int maps_open(struct inode *inode, struct file *file)
271{
272 return do_maps_open(inode, file, &proc_pid_maps_op);
273}
274
275const struct file_operations proc_maps_operations = {
276 .open = maps_open,
277 .read = seq_read,
278 .llseek = seq_lseek,
279 .release = seq_release_private,
280};
281
282/*
283 * Proportional Set Size(PSS): my share of RSS.
284 *
285 * PSS of a process is the count of pages it has in memory, where each
286 * page is divided by the number of processes sharing it. So if a
287 * process has 1000 pages all to itself, and 1000 shared with one other
288 * process, its PSS will be 1500.
289 *
290 * To keep (accumulated) division errors low, we adopt a 64bit
291 * fixed-point pss counter to minimize division errors. So (pss >>
292 * PSS_SHIFT) would be the real byte count.
293 *
294 * A shift of 12 before division means (assuming 4K page size):
295 * - 1M 3-user-pages add up to 8KB errors;
296 * - supports mapcount up to 2^24, or 16M;
297 * - supports PSS up to 2^52 bytes, or 4PB.
298 */
299#define PSS_SHIFT 12
300
1e883281 301#ifdef CONFIG_PROC_PAGE_MONITOR
214e471f 302struct mem_size_stats {
a6198797
MM
303 struct vm_area_struct *vma;
304 unsigned long resident;
305 unsigned long shared_clean;
306 unsigned long shared_dirty;
307 unsigned long private_clean;
308 unsigned long private_dirty;
309 unsigned long referenced;
214e471f 310 unsigned long swap;
a6198797
MM
311 u64 pss;
312};
313
b3ae5acb 314static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 315 struct mm_walk *walk)
e070ad49 316{
2165009b 317 struct mem_size_stats *mss = walk->private;
b3ae5acb 318 struct vm_area_struct *vma = mss->vma;
e070ad49 319 pte_t *pte, ptent;
705e87c0 320 spinlock_t *ptl;
e070ad49 321 struct page *page;
ec4dd3eb 322 int mapcount;
e070ad49 323
705e87c0 324 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
826fad1b 325 for (; addr != end; pte++, addr += PAGE_SIZE) {
e070ad49 326 ptent = *pte;
214e471f
PZ
327
328 if (is_swap_pte(ptent)) {
329 mss->swap += PAGE_SIZE;
330 continue;
331 }
332
705e87c0 333 if (!pte_present(ptent))
e070ad49
ML
334 continue;
335
336 mss->resident += PAGE_SIZE;
ad820c5d
NP
337
338 page = vm_normal_page(vma, addr, ptent);
339 if (!page)
e070ad49
ML
340 continue;
341
f79f177c
DR
342 /* Accumulate the size in pages that have been accessed. */
343 if (pte_young(ptent) || PageReferenced(page))
344 mss->referenced += PAGE_SIZE;
ec4dd3eb
FW
345 mapcount = page_mapcount(page);
346 if (mapcount >= 2) {
e070ad49
ML
347 if (pte_dirty(ptent))
348 mss->shared_dirty += PAGE_SIZE;
349 else
350 mss->shared_clean += PAGE_SIZE;
ec4dd3eb 351 mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
e070ad49
ML
352 } else {
353 if (pte_dirty(ptent))
354 mss->private_dirty += PAGE_SIZE;
355 else
356 mss->private_clean += PAGE_SIZE;
ec4dd3eb 357 mss->pss += (PAGE_SIZE << PSS_SHIFT);
e070ad49 358 }
826fad1b 359 }
705e87c0
HD
360 pte_unmap_unlock(pte - 1, ptl);
361 cond_resched();
b3ae5acb 362 return 0;
e070ad49
ML
363}
364
e070ad49
ML
365static int show_smap(struct seq_file *m, void *v)
366{
367 struct vm_area_struct *vma = v;
e070ad49 368 struct mem_size_stats mss;
4752c369 369 int ret;
2165009b
DH
370 struct mm_walk smaps_walk = {
371 .pmd_entry = smaps_pte_range,
372 .mm = vma->vm_mm,
373 .private = &mss,
374 };
e070ad49
ML
375
376 memset(&mss, 0, sizeof mss);
b3ae5acb 377 mss.vma = vma;
5ddfae16 378 if (vma->vm_mm && !is_vm_hugetlb_page(vma))
2165009b 379 walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
4752c369
MM
380
381 ret = show_map(m, v);
382 if (ret)
383 return ret;
384
385 seq_printf(m,
386 "Size: %8lu kB\n"
387 "Rss: %8lu kB\n"
388 "Pss: %8lu kB\n"
389 "Shared_Clean: %8lu kB\n"
390 "Shared_Dirty: %8lu kB\n"
391 "Private_Clean: %8lu kB\n"
392 "Private_Dirty: %8lu kB\n"
214e471f
PZ
393 "Referenced: %8lu kB\n"
394 "Swap: %8lu kB\n",
4752c369
MM
395 (vma->vm_end - vma->vm_start) >> 10,
396 mss.resident >> 10,
397 (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
398 mss.shared_clean >> 10,
399 mss.shared_dirty >> 10,
400 mss.private_clean >> 10,
401 mss.private_dirty >> 10,
214e471f
PZ
402 mss.referenced >> 10,
403 mss.swap >> 10);
4752c369
MM
404
405 return ret;
e070ad49
ML
406}
407
03a44825 408static const struct seq_operations proc_pid_smaps_op = {
a6198797
MM
409 .start = m_start,
410 .next = m_next,
411 .stop = m_stop,
412 .show = show_smap
413};
414
415static int smaps_open(struct inode *inode, struct file *file)
416{
417 return do_maps_open(inode, file, &proc_pid_smaps_op);
418}
419
420const struct file_operations proc_smaps_operations = {
421 .open = smaps_open,
422 .read = seq_read,
423 .llseek = seq_lseek,
424 .release = seq_release_private,
425};
426
427static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
2165009b 428 unsigned long end, struct mm_walk *walk)
a6198797 429{
2165009b 430 struct vm_area_struct *vma = walk->private;
a6198797
MM
431 pte_t *pte, ptent;
432 spinlock_t *ptl;
433 struct page *page;
434
435 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
436 for (; addr != end; pte++, addr += PAGE_SIZE) {
437 ptent = *pte;
438 if (!pte_present(ptent))
439 continue;
440
441 page = vm_normal_page(vma, addr, ptent);
442 if (!page)
443 continue;
444
445 /* Clear accessed and referenced bits. */
446 ptep_test_and_clear_young(vma, addr, pte);
447 ClearPageReferenced(page);
448 }
449 pte_unmap_unlock(pte - 1, ptl);
450 cond_resched();
451 return 0;
452}
453
f248dcb3
MM
454static ssize_t clear_refs_write(struct file *file, const char __user *buf,
455 size_t count, loff_t *ppos)
b813e931 456{
f248dcb3
MM
457 struct task_struct *task;
458 char buffer[PROC_NUMBUF], *end;
459 struct mm_struct *mm;
b813e931
DR
460 struct vm_area_struct *vma;
461
f248dcb3
MM
462 memset(buffer, 0, sizeof(buffer));
463 if (count > sizeof(buffer) - 1)
464 count = sizeof(buffer) - 1;
465 if (copy_from_user(buffer, buf, count))
466 return -EFAULT;
467 if (!simple_strtol(buffer, &end, 0))
468 return -EINVAL;
469 if (*end == '\n')
470 end++;
471 task = get_proc_task(file->f_path.dentry->d_inode);
472 if (!task)
473 return -ESRCH;
474 mm = get_task_mm(task);
475 if (mm) {
20cbc972
AM
476 struct mm_walk clear_refs_walk = {
477 .pmd_entry = clear_refs_pte_range,
478 .mm = mm,
479 };
f248dcb3 480 down_read(&mm->mmap_sem);
2165009b
DH
481 for (vma = mm->mmap; vma; vma = vma->vm_next) {
482 clear_refs_walk.private = vma;
f248dcb3 483 if (!is_vm_hugetlb_page(vma))
2165009b
DH
484 walk_page_range(vma->vm_start, vma->vm_end,
485 &clear_refs_walk);
486 }
f248dcb3
MM
487 flush_tlb_mm(mm);
488 up_read(&mm->mmap_sem);
489 mmput(mm);
490 }
491 put_task_struct(task);
492 if (end - buffer == 0)
493 return -EIO;
494 return end - buffer;
b813e931
DR
495}
496
f248dcb3
MM
497const struct file_operations proc_clear_refs_operations = {
498 .write = clear_refs_write,
499};
500
85863e47 501struct pagemapread {
aae8679b 502 u64 __user *out, *end;
85863e47
MM
503};
504
f16278c6
HR
505#define PM_ENTRY_BYTES sizeof(u64)
506#define PM_STATUS_BITS 3
507#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
508#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
509#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
510#define PM_PSHIFT_BITS 6
511#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
512#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
513#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
514#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
515#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
516
517#define PM_PRESENT PM_STATUS(4LL)
518#define PM_SWAP PM_STATUS(2LL)
519#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
85863e47
MM
520#define PM_END_OF_BUFFER 1
521
522static int add_to_pagemap(unsigned long addr, u64 pfn,
523 struct pagemapread *pm)
524{
85863e47
MM
525 if (put_user(pfn, pm->out))
526 return -EFAULT;
aae8679b
TT
527 pm->out++;
528 if (pm->out >= pm->end)
529 return PM_END_OF_BUFFER;
85863e47
MM
530 return 0;
531}
532
533static int pagemap_pte_hole(unsigned long start, unsigned long end,
2165009b 534 struct mm_walk *walk)
85863e47 535{
2165009b 536 struct pagemapread *pm = walk->private;
85863e47
MM
537 unsigned long addr;
538 int err = 0;
539 for (addr = start; addr < end; addr += PAGE_SIZE) {
540 err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
541 if (err)
542 break;
543 }
544 return err;
545}
546
9d02dbc8 547static u64 swap_pte_to_pagemap_entry(pte_t pte)
85863e47
MM
548{
549 swp_entry_t e = pte_to_swp_entry(pte);
f16278c6 550 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
85863e47
MM
551}
552
bcf8039e
DH
553static unsigned long pte_to_pagemap_entry(pte_t pte)
554{
555 unsigned long pme = 0;
556 if (is_swap_pte(pte))
557 pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
558 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
559 else if (pte_present(pte))
560 pme = PM_PFRAME(pte_pfn(pte))
561 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
562 return pme;
563}
564
85863e47 565static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
2165009b 566 struct mm_walk *walk)
85863e47 567{
bcf8039e 568 struct vm_area_struct *vma;
2165009b 569 struct pagemapread *pm = walk->private;
85863e47
MM
570 pte_t *pte;
571 int err = 0;
572
bcf8039e
DH
573 /* find the first VMA at or above 'addr' */
574 vma = find_vma(walk->mm, addr);
85863e47
MM
575 for (; addr != end; addr += PAGE_SIZE) {
576 u64 pfn = PM_NOT_PRESENT;
bcf8039e
DH
577
578 /* check to see if we've left 'vma' behind
579 * and need a new, higher one */
580 if (vma && (addr >= vma->vm_end))
581 vma = find_vma(walk->mm, addr);
582
583 /* check that 'vma' actually covers this address,
584 * and that it isn't a huge page vma */
585 if (vma && (vma->vm_start <= addr) &&
586 !is_vm_hugetlb_page(vma)) {
587 pte = pte_offset_map(pmd, addr);
588 pfn = pte_to_pagemap_entry(*pte);
589 /* unmap before userspace copy */
590 pte_unmap(pte);
591 }
85863e47
MM
592 err = add_to_pagemap(addr, pfn, pm);
593 if (err)
594 return err;
595 }
596
597 cond_resched();
598
599 return err;
600}
601
85863e47
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602/*
603 * /proc/pid/pagemap - an array mapping virtual pages to pfns
604 *
f16278c6
HR
605 * For each page in the address space, this file contains one 64-bit entry
606 * consisting of the following:
607 *
608 * Bits 0-55 page frame number (PFN) if present
609 * Bits 0-4 swap type if swapped
610 * Bits 5-55 swap offset if swapped
611 * Bits 55-60 page shift (page size = 1<<page shift)
612 * Bit 61 reserved for future use
613 * Bit 62 page swapped
614 * Bit 63 page present
615 *
616 * If the page is not present but in swap, then the PFN contains an
617 * encoding of the swap file number and the page's offset into the
618 * swap. Unmapped pages return a null PFN. This allows determining
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619 * precisely which pages are mapped (or in swap) and comparing mapped
620 * pages between processes.
621 *
622 * Efficient users of this interface will use /proc/pid/maps to
623 * determine which areas of memory are actually mapped and llseek to
624 * skip over unmapped regions.
625 */
626static ssize_t pagemap_read(struct file *file, char __user *buf,
627 size_t count, loff_t *ppos)
628{
629 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
630 struct page **pages, *page;
631 unsigned long uaddr, uend;
632 struct mm_struct *mm;
633 struct pagemapread pm;
634 int pagecount;
635 int ret = -ESRCH;
ee1e6ab6 636 struct mm_walk pagemap_walk = {};
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637 unsigned long src;
638 unsigned long svpfn;
639 unsigned long start_vaddr;
640 unsigned long end_vaddr;
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641
642 if (!task)
643 goto out;
644
645 ret = -EACCES;
006ebb40 646 if (!ptrace_may_access(task, PTRACE_MODE_READ))
fb39380b 647 goto out_task;
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648
649 ret = -EINVAL;
650 /* file position must be aligned */
aae8679b 651 if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
fb39380b 652 goto out_task;
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653
654 ret = 0;
655 mm = get_task_mm(task);
656 if (!mm)
fb39380b 657 goto out_task;
85863e47 658
5d7e0d2b 659
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660 uaddr = (unsigned long)buf & PAGE_MASK;
661 uend = (unsigned long)(buf + count);
662 pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE;
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663 ret = 0;
664 if (pagecount == 0)
665 goto out_mm;
666 pages = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
667 ret = -ENOMEM;
85863e47 668 if (!pages)
fb39380b 669 goto out_mm;
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670
671 down_read(&current->mm->mmap_sem);
672 ret = get_user_pages(current, current->mm, uaddr, pagecount,
673 1, 0, pages, NULL);
674 up_read(&current->mm->mmap_sem);
675
676 if (ret < 0)
677 goto out_free;
678
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MT
679 if (ret != pagecount) {
680 pagecount = ret;
681 ret = -EFAULT;
682 goto out_pages;
683 }
684
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685 pm.out = (u64 *)buf;
686 pm.end = (u64 *)(buf + count);
85863e47 687
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688 pagemap_walk.pmd_entry = pagemap_pte_range;
689 pagemap_walk.pte_hole = pagemap_pte_hole;
690 pagemap_walk.mm = mm;
691 pagemap_walk.private = &pm;
692
693 src = *ppos;
694 svpfn = src / PM_ENTRY_BYTES;
695 start_vaddr = svpfn << PAGE_SHIFT;
696 end_vaddr = TASK_SIZE_OF(task);
697
698 /* watch out for wraparound */
699 if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
700 start_vaddr = end_vaddr;
701
702 /*
703 * The odds are that this will stop walking way
704 * before end_vaddr, because the length of the
705 * user buffer is tracked in "pm", and the walk
706 * will stop when we hit the end of the buffer.
707 */
708 ret = walk_page_range(start_vaddr, end_vaddr, &pagemap_walk);
709 if (ret == PM_END_OF_BUFFER)
710 ret = 0;
711 /* don't need mmap_sem for these, but this looks cleaner */
712 *ppos += (char *)pm.out - buf;
713 if (!ret)
714 ret = (char *)pm.out - buf;
85863e47 715
fb39380b 716out_pages:
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717 for (; pagecount; pagecount--) {
718 page = pages[pagecount-1];
719 if (!PageReserved(page))
720 SetPageDirty(page);
721 page_cache_release(page);
722 }
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723out_free:
724 kfree(pages);
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MT
725out_mm:
726 mmput(mm);
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727out_task:
728 put_task_struct(task);
729out:
730 return ret;
731}
732
733const struct file_operations proc_pagemap_operations = {
734 .llseek = mem_lseek, /* borrow this */
735 .read = pagemap_read,
736};
1e883281 737#endif /* CONFIG_PROC_PAGE_MONITOR */
85863e47 738
6e21c8f1 739#ifdef CONFIG_NUMA
1a75a6c8 740extern int show_numa_map(struct seq_file *m, void *v);
6e21c8f1 741
03a44825 742static const struct seq_operations proc_pid_numa_maps_op = {
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CL
743 .start = m_start,
744 .next = m_next,
745 .stop = m_stop,
3bbfe059 746 .show = show_numa_map,
6e21c8f1 747};
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748
749static int numa_maps_open(struct inode *inode, struct file *file)
750{
751 return do_maps_open(inode, file, &proc_pid_numa_maps_op);
752}
753
00977a59 754const struct file_operations proc_numa_maps_operations = {
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755 .open = numa_maps_open,
756 .read = seq_read,
757 .llseek = seq_lseek,
99f89551 758 .release = seq_release_private,
662795de 759};
6e21c8f1 760#endif
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