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proc: fix NULL dereference when reading /proc/<pid>/auxv
[linux-2.6-block.git] / fs / proc / base.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
e070ad49
ML		 14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
1da177e4
LT		 48 */
49
50#include <asm/uaccess.h>
51
1da177e4
LT		 52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
5995477a 56#include <linux/task_io_accounting_ops.h>
1da177e4 57#include <linux/init.h>
16f7e0fe 58#include <linux/capability.h>
1da177e4 59#include <linux/file.h>
9f3acc31 60#include <linux/fdtable.h>
1da177e4
LT		 61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
6b3286ed 64#include <linux/mnt_namespace.h>
1da177e4 65#include <linux/mm.h>
a63d83f4 66#include <linux/swap.h>
b835996f 67#include <linux/rcupdate.h>
1da177e4 68#include <linux/kallsyms.h>
2ec220e2 69#include <linux/stacktrace.h>
d85f50d5 70#include <linux/resource.h>
5096add8 71#include <linux/module.h>
1da177e4
LT		 72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
0d094efe 75#include <linux/tracehook.h>
87ebdc00 76#include <linux/printk.h>
a424316c 77#include <linux/cgroup.h>
1da177e4
LT		 78#include <linux/cpuset.h>
79#include <linux/audit.h>
5addc5dd 80#include <linux/poll.h>
1651e14e 81#include <linux/nsproxy.h>
8ac773b4 82#include <linux/oom.h>
3cb4a0bb 83#include <linux/elf.h>
60347f67 84#include <linux/pid_namespace.h>
22d917d8 85#include <linux/user_namespace.h>
5ad4e53b 86#include <linux/fs_struct.h>
5a0e3ad6 87#include <linux/slab.h>
640708a2 88#include <linux/flex_array.h>
48f6a7a5 89#include <linux/posix-timers.h>
f133ecca
CM		 90#ifdef CONFIG_HARDWALL
91#include <asm/hardwall.h>
92#endif
43d2b113 93#include <trace/events/oom.h>
1da177e4 94#include "internal.h"
faf60af1 95#include "fd.h"
1da177e4 96
0f2fe20f
EB		 97/* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
1da177e4 107struct pid_entry {
cedbccab 108 const char *name;
c5141e6d 109 int len;
d161a13f 110 umode_t mode;
c5ef1c42 111 const struct inode_operations *iop;
00977a59 112 const struct file_operations *fop;
20cdc894 113 union proc_op op;
1da177e4
LT		 114};
115
61a28784 116#define NOD(NAME, MODE, IOP, FOP, OP) { \
20cdc894 117 .name = (NAME), \
c5141e6d 118 .len = sizeof(NAME) - 1, \
20cdc894
EB		 119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123}
124
631f9c18
AD		 125#define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127#define LNK(NAME, get_link) \
61a28784 128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
20cdc894 129 &proc_pid_link_inode_operations, NULL, \
631f9c18
AD		 130 { .proc_get_link = get_link } )
131#define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
631f9c18 133#define ONE(NAME, MODE, show) \
be614086
EB		 134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
631f9c18 136 { .proc_show = show } )
1da177e4 137
aed54175
VN		 138/*
139 * Count the number of hardlinks for the pid_entry table, excluding the .
140 * and .. links.
141 */
142static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
143 unsigned int n)
144{
145 unsigned int i;
146 unsigned int count;
147
148 count = 0;
149 for (i = 0; i < n; ++i) {
150 if (S_ISDIR(entries[i].mode))
151 ++count;
152 }
153
154 return count;
155}
156
f7ad3c6b 157static int get_task_root(struct task_struct *task, struct path *root)
1da177e4 158{
7c2c7d99
HD		 159 int result = -ENOENT;
160
0494f6ec 161 task_lock(task);
f7ad3c6b
MS		 162 if (task->fs) {
163 get_fs_root(task->fs, root);
7c2c7d99
HD		 164 result = 0;
165 }
0494f6ec 166 task_unlock(task);
7c2c7d99 167 return result;
0494f6ec
MS		 168}
169
7773fbc5 170static int proc_cwd_link(struct dentry *dentry, struct path *path)
0494f6ec 171{
2b0143b5 172 struct task_struct *task = get_proc_task(d_inode(dentry));
0494f6ec 173 int result = -ENOENT;
99f89551
EB		 174
175 if (task) {
f7ad3c6b
MS		 176 task_lock(task);
177 if (task->fs) {
178 get_fs_pwd(task->fs, path);
179 result = 0;
180 }
181 task_unlock(task);
99f89551
EB		 182 put_task_struct(task);
183 }
1da177e4
LT		 184 return result;
185}
186
7773fbc5 187static int proc_root_link(struct dentry *dentry, struct path *path)
1da177e4 188{
2b0143b5 189 struct task_struct *task = get_proc_task(d_inode(dentry));
1da177e4 190 int result = -ENOENT;
99f89551
EB		 191
192 if (task) {
f7ad3c6b 193 result = get_task_root(task, path);
99f89551
EB		 194 put_task_struct(task);
195 }
1da177e4
LT		 196 return result;
197}
198
c2c0bb44
AD		 199static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
200 size_t _count, loff_t *pos)
1da177e4 201{
c2c0bb44
AD		 202 struct task_struct *tsk;
203 struct mm_struct *mm;
204 char *page;
205 unsigned long count = _count;
206 unsigned long arg_start, arg_end, env_start, env_end;
207 unsigned long len1, len2, len;
208 unsigned long p;
209 char c;
210 ssize_t rv;
211
212 BUG_ON(*pos < 0);
213
214 tsk = get_proc_task(file_inode(file));
215 if (!tsk)
216 return -ESRCH;
217 mm = get_task_mm(tsk);
218 put_task_struct(tsk);
219 if (!mm)
220 return 0;
221 /* Check if process spawned far enough to have cmdline. */
222 if (!mm->env_end) {
223 rv = 0;
224 goto out_mmput;
225 }
226
227 page = (char *)__get_free_page(GFP_TEMPORARY);
228 if (!page) {
229 rv = -ENOMEM;
230 goto out_mmput;
231 }
232
233 down_read(&mm->mmap_sem);
234 arg_start = mm->arg_start;
235 arg_end = mm->arg_end;
236 env_start = mm->env_start;
237 env_end = mm->env_end;
238 up_read(&mm->mmap_sem);
239
240 BUG_ON(arg_start > arg_end);
241 BUG_ON(env_start > env_end);
242
243 len1 = arg_end - arg_start;
244 len2 = env_end - env_start;
245
3581d458
AD		 246 /* Empty ARGV. */
247 if (len1 == 0) {
248 rv = 0;
249 goto out_free_page;
250 }
2ca66ff7 251 /*
c2c0bb44
AD		 252 * Inherently racy -- command line shares address space
253 * with code and data.
2ca66ff7 254 */
272ddc8b 255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
c2c0bb44
AD		 256 if (rv <= 0)
257 goto out_free_page;
258
259 rv = 0;
260
261 if (c == '\0') {
262 /* Command line (set of strings) occupies whole ARGV. */
263 if (len1 <= *pos)
264 goto out_free_page;
265
266 p = arg_start + *pos;
267 len = len1 - *pos;
268 while (count > 0 && len > 0) {
269 unsigned int _count;
270 int nr_read;
271
272 _count = min3(count, len, PAGE_SIZE);
272ddc8b 273 nr_read = access_remote_vm(mm, p, page, _count, 0);
c2c0bb44
AD		 274 if (nr_read < 0)
275 rv = nr_read;
276 if (nr_read <= 0)
277 goto out_free_page;
278
279 if (copy_to_user(buf, page, nr_read)) {
280 rv = -EFAULT;
281 goto out_free_page;
282 }
283
284 p += nr_read;
285 len -= nr_read;
286 buf += nr_read;
287 count -= nr_read;
288 rv += nr_read;
289 }
290 } else {
291 /*
292 * Command line (1 string) occupies ARGV and maybe
293 * extends into ENVP.
294 */
295 if (len1 + len2 <= *pos)
296 goto skip_argv_envp;
297 if (len1 <= *pos)
298 goto skip_argv;
299
300 p = arg_start + *pos;
301 len = len1 - *pos;
302 while (count > 0 && len > 0) {
303 unsigned int _count, l;
304 int nr_read;
305 bool final;
306
307 _count = min3(count, len, PAGE_SIZE);
272ddc8b 308 nr_read = access_remote_vm(mm, p, page, _count, 0);
c2c0bb44
AD		 309 if (nr_read < 0)
310 rv = nr_read;
311 if (nr_read <= 0)
312 goto out_free_page;
313
314 /*
315 * Command line can be shorter than whole ARGV
316 * even if last "marker" byte says it is not.
317 */
318 final = false;
319 l = strnlen(page, nr_read);
320 if (l < nr_read) {
321 nr_read = l;
322 final = true;
323 }
324
325 if (copy_to_user(buf, page, nr_read)) {
326 rv = -EFAULT;
327 goto out_free_page;
328 }
329
330 p += nr_read;
331 len -= nr_read;
332 buf += nr_read;
333 count -= nr_read;
334 rv += nr_read;
335
336 if (final)
337 goto out_free_page;
338 }
339skip_argv:
340 /*
341 * Command line (1 string) occupies ARGV and
342 * extends into ENVP.
343 */
344 if (len1 <= *pos) {
345 p = env_start + *pos - len1;
346 len = len1 + len2 - *pos;
347 } else {
348 p = env_start;
349 len = len2;
350 }
351 while (count > 0 && len > 0) {
352 unsigned int _count, l;
353 int nr_read;
354 bool final;
355
356 _count = min3(count, len, PAGE_SIZE);
272ddc8b 357 nr_read = access_remote_vm(mm, p, page, _count, 0);
c2c0bb44
AD		 358 if (nr_read < 0)
359 rv = nr_read;
360 if (nr_read <= 0)
361 goto out_free_page;
362
363 /* Find EOS. */
364 final = false;
365 l = strnlen(page, nr_read);
366 if (l < nr_read) {
367 nr_read = l;
368 final = true;
369 }
370
371 if (copy_to_user(buf, page, nr_read)) {
372 rv = -EFAULT;
373 goto out_free_page;
374 }
375
376 p += nr_read;
377 len -= nr_read;
378 buf += nr_read;
379 count -= nr_read;
380 rv += nr_read;
381
382 if (final)
383 goto out_free_page;
384 }
385skip_argv_envp:
386 ;
387 }
388
389out_free_page:
390 free_page((unsigned long)page);
391out_mmput:
392 mmput(mm);
393 if (rv > 0)
394 *pos += rv;
395 return rv;
1da177e4
LT		 396}
397
c2c0bb44
AD		 398static const struct file_operations proc_pid_cmdline_ops = {
399 .read = proc_pid_cmdline_read,
400 .llseek = generic_file_llseek,
401};
402
1da177e4
LT		 403#ifdef CONFIG_KALLSYMS
404/*
405 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
406 * Returns the resolved symbol. If that fails, simply return the address.
407 */
edfcd606
AD		 408static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
409 struct pid *pid, struct task_struct *task)
1da177e4 410{
ffb45122 411 unsigned long wchan;
9281acea 412 char symname[KSYM_NAME_LEN];
1da177e4
LT		 413
414 wchan = get_wchan(task);
415
caaee623
JH		 416 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
417 && !lookup_symbol_name(wchan, symname))
25ce3191 418 seq_printf(m, "%s", symname);
b2f73922 419 else
1e92a61c 420 seq_putc(m, '0');
25ce3191
JP		 421
422 return 0;
1da177e4
LT		 423}
424#endif /* CONFIG_KALLSYMS */
425
a9712bc1
AV		 426static int lock_trace(struct task_struct *task)
427{
428 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
429 if (err)
430 return err;
caaee623 431 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
a9712bc1
AV		 432 mutex_unlock(&task->signal->cred_guard_mutex);
433 return -EPERM;
434 }
435 return 0;
436}
437
438static void unlock_trace(struct task_struct *task)
439{
440 mutex_unlock(&task->signal->cred_guard_mutex);
441}
442
2ec220e2
KC		 443#ifdef CONFIG_STACKTRACE
444
445#define MAX_STACK_TRACE_DEPTH 64
446
447static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
448 struct pid *pid, struct task_struct *task)
449{
450 struct stack_trace trace;
451 unsigned long *entries;
a9712bc1 452 int err;
2ec220e2
KC		 453 int i;
454
455 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
456 if (!entries)
457 return -ENOMEM;
458
459 trace.nr_entries = 0;
460 trace.max_entries = MAX_STACK_TRACE_DEPTH;
461 trace.entries = entries;
462 trace.skip = 0;
2ec220e2 463
a9712bc1
AV		 464 err = lock_trace(task);
465 if (!err) {
466 save_stack_trace_tsk(task, &trace);
467
468 for (i = 0; i < trace.nr_entries; i++) {
8b927d73 469 seq_printf(m, "[<%pK>] %pB\n",
a9712bc1
AV		 470 (void *)entries[i], (void *)entries[i]);
471 }
472 unlock_trace(task);
2ec220e2
KC		 473 }
474 kfree(entries);
475
a9712bc1 476 return err;
2ec220e2
KC		 477}
478#endif
479
5968cece 480#ifdef CONFIG_SCHED_INFO
1da177e4
LT		 481/*
482 * Provides /proc/PID/schedstat
483 */
f6e826ca
AD		 484static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
485 struct pid *pid, struct task_struct *task)
1da177e4 486{
5968cece
NR		 487 if (unlikely(!sched_info_on()))
488 seq_printf(m, "0 0 0\n");
489 else
490 seq_printf(m, "%llu %llu %lu\n",
25ce3191
JP		 491 (unsigned long long)task->se.sum_exec_runtime,
492 (unsigned long long)task->sched_info.run_delay,
493 task->sched_info.pcount);
494
495 return 0;
1da177e4
LT		 496}
497#endif
498
9745512c
AV		 499#ifdef CONFIG_LATENCYTOP
500static int lstats_show_proc(struct seq_file *m, void *v)
501{
502 int i;
13d77c37
HS		 503 struct inode *inode = m->private;
504 struct task_struct *task = get_proc_task(inode);
9745512c 505
13d77c37
HS		 506 if (!task)
507 return -ESRCH;
508 seq_puts(m, "Latency Top version : v0.1\n");
9745512c 509 for (i = 0; i < 32; i++) {
34e49d4f
JP		 510 struct latency_record *lr = &task->latency_record[i];
511 if (lr->backtrace[0]) {
9745512c 512 int q;
34e49d4f
JP		 513 seq_printf(m, "%i %li %li",
514 lr->count, lr->time, lr->max);
9745512c 515 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
34e49d4f
JP		 516 unsigned long bt = lr->backtrace[q];
517 if (!bt)
9745512c 518 break;
34e49d4f 519 if (bt == ULONG_MAX)
9745512c 520 break;
34e49d4f 521 seq_printf(m, " %ps", (void *)bt);
9745512c 522 }
9d6de12f 523 seq_putc(m, '\n');
9745512c
AV		 524 }
525
526 }
13d77c37 527 put_task_struct(task);
9745512c
AV		 528 return 0;
529}
530
531static int lstats_open(struct inode *inode, struct file *file)
532{
13d77c37 533 return single_open(file, lstats_show_proc, inode);
d6643d12
HS		 534}
535
9745512c
AV		 536static ssize_t lstats_write(struct file *file, const char __user *buf,
537 size_t count, loff_t *offs)
538{
496ad9aa 539 struct task_struct *task = get_proc_task(file_inode(file));
9745512c 540
13d77c37
HS		 541 if (!task)
542 return -ESRCH;
9745512c 543 clear_all_latency_tracing(task);
13d77c37 544 put_task_struct(task);
9745512c
AV		 545
546 return count;
547}
548
549static const struct file_operations proc_lstats_operations = {
550 .open = lstats_open,
551 .read = seq_read,
552 .write = lstats_write,
553 .llseek = seq_lseek,
13d77c37 554 .release = single_release,
9745512c
AV		 555};
556
557#endif
558
6ba51e37
AD		 559static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
560 struct pid *pid, struct task_struct *task)
1da177e4 561{
a7f638f9 562 unsigned long totalpages = totalram_pages + total_swap_pages;
b95c35e7 563 unsigned long points = 0;
1da177e4 564
ef419398
ON		 565 points = oom_badness(task, NULL, NULL, totalpages) *
566 1000 / totalpages;
25ce3191
JP		 567 seq_printf(m, "%lu\n", points);
568
569 return 0;
1da177e4
LT		 570}
571
d85f50d5 572struct limit_names {
cedbccab
AD		 573 const char *name;
574 const char *unit;
d85f50d5
NH		 575};
576
577static const struct limit_names lnames[RLIM_NLIMITS] = {
cff4edb5 578 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
d85f50d5
NH		 579 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
580 [RLIMIT_DATA] = {"Max data size", "bytes"},
581 [RLIMIT_STACK] = {"Max stack size", "bytes"},
582 [RLIMIT_CORE] = {"Max core file size", "bytes"},
583 [RLIMIT_RSS] = {"Max resident set", "bytes"},
584 [RLIMIT_NPROC] = {"Max processes", "processes"},
585 [RLIMIT_NOFILE] = {"Max open files", "files"},
586 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
587 [RLIMIT_AS] = {"Max address space", "bytes"},
588 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
589 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
590 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
591 [RLIMIT_NICE] = {"Max nice priority", NULL},
592 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
8808117c 593 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
d85f50d5
NH		 594};
595
596/* Display limits for a process */
1c963eb1
AD		 597static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
598 struct pid *pid, struct task_struct *task)
d85f50d5
NH		 599{
600 unsigned int i;
d85f50d5 601 unsigned long flags;
d85f50d5
NH		 602
603 struct rlimit rlim[RLIM_NLIMITS];
604
a6bebbc8 605 if (!lock_task_sighand(task, &flags))
d85f50d5 606 return 0;
d85f50d5
NH		 607 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
608 unlock_task_sighand(task, &flags);
d85f50d5
NH		 609
610 /*
611 * print the file header
612 */
1c963eb1 613 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
25ce3191 614 "Limit", "Soft Limit", "Hard Limit", "Units");
d85f50d5
NH		 615
616 for (i = 0; i < RLIM_NLIMITS; i++) {
617 if (rlim[i].rlim_cur == RLIM_INFINITY)
1c963eb1 618 seq_printf(m, "%-25s %-20s ",
25ce3191 619 lnames[i].name, "unlimited");
d85f50d5 620 else
1c963eb1 621 seq_printf(m, "%-25s %-20lu ",
25ce3191 622 lnames[i].name, rlim[i].rlim_cur);
d85f50d5
NH		 623
624 if (rlim[i].rlim_max == RLIM_INFINITY)
1c963eb1 625 seq_printf(m, "%-20s ", "unlimited");
d85f50d5 626 else
1c963eb1 627 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
d85f50d5
NH		 628
629 if (lnames[i].unit)
1c963eb1 630 seq_printf(m, "%-10s\n", lnames[i].unit);
d85f50d5 631 else
1c963eb1 632 seq_putc(m, '\n');
d85f50d5
NH		 633 }
634
1c963eb1 635 return 0;
d85f50d5
NH		 636}
637
ebcb6734 638#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6
AD		 639static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
640 struct pid *pid, struct task_struct *task)
ebcb6734
RM		 641{
642 long nr;
643 unsigned long args[6], sp, pc;
25ce3191
JP		 644 int res;
645
646 res = lock_trace(task);
a9712bc1
AV		 647 if (res)
648 return res;
ebcb6734
RM		 649
650 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
09d93bd6 651 seq_puts(m, "running\n");
a9712bc1 652 else if (nr < 0)
09d93bd6 653 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
a9712bc1 654 else
09d93bd6 655 seq_printf(m,
ebcb6734
RM		 656 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
657 nr,
658 args[0], args[1], args[2], args[3], args[4], args[5],
659 sp, pc);
a9712bc1 660 unlock_trace(task);
25ce3191
JP		 661
662 return 0;
ebcb6734
RM		 663}
664#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
665
1da177e4
LT		 666/************************************************************************/
667/* Here the fs part begins */
668/************************************************************************/
669
670/* permission checks */
778c1144 671static int proc_fd_access_allowed(struct inode *inode)
1da177e4 672{
778c1144
EB		 673 struct task_struct *task;
674 int allowed = 0;
df26c40e
EB		 675 /* Allow access to a task's file descriptors if it is us or we
676 * may use ptrace attach to the process and find out that
677 * information.
778c1144
EB		 678 */
679 task = get_proc_task(inode);
df26c40e 680 if (task) {
caaee623 681 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
778c1144 682 put_task_struct(task);
df26c40e 683 }
778c1144 684 return allowed;
1da177e4
LT		 685}
686
6b4e306a 687int proc_setattr(struct dentry *dentry, struct iattr *attr)
6d76fa58
LT		 688{
689 int error;
2b0143b5 690 struct inode *inode = d_inode(dentry);
6d76fa58
LT		 691
692 if (attr->ia_valid & ATTR_MODE)
693 return -EPERM;
694
31051c85 695 error = setattr_prepare(dentry, attr);
1025774c
CH		 696 if (error)
697 return error;
698
1025774c
CH		 699 setattr_copy(inode, attr);
700 mark_inode_dirty(inode);
701 return 0;
6d76fa58
LT		 702}
703
0499680a
VK		 704/*
705 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
706 * or euid/egid (for hide_pid_min=2)?
707 */
708static bool has_pid_permissions(struct pid_namespace *pid,
709 struct task_struct *task,
710 int hide_pid_min)
711{
712 if (pid->hide_pid < hide_pid_min)
713 return true;
714 if (in_group_p(pid->pid_gid))
715 return true;
caaee623 716 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
0499680a
VK		 717}
718
719
720static int proc_pid_permission(struct inode *inode, int mask)
721{
722 struct pid_namespace *pid = inode->i_sb->s_fs_info;
723 struct task_struct *task;
724 bool has_perms;
725
726 task = get_proc_task(inode);
a2ef990a
XF		 727 if (!task)
728 return -ESRCH;
0499680a
VK		 729 has_perms = has_pid_permissions(pid, task, 1);
730 put_task_struct(task);
731
732 if (!has_perms) {
733 if (pid->hide_pid == 2) {
734 /*
735 * Let's make getdents(), stat(), and open()
736 * consistent with each other. If a process
737 * may not stat() a file, it shouldn't be seen
738 * in procfs at all.
739 */
740 return -ENOENT;
741 }
742
743 return -EPERM;
744 }
745 return generic_permission(inode, mask);
746}
747
748
749
c5ef1c42 750static const struct inode_operations proc_def_inode_operations = {
6d76fa58
LT		 751 .setattr = proc_setattr,
752};
753
be614086
EB		 754static int proc_single_show(struct seq_file *m, void *v)
755{
756 struct inode *inode = m->private;
757 struct pid_namespace *ns;
758 struct pid *pid;
759 struct task_struct *task;
760 int ret;
761
762 ns = inode->i_sb->s_fs_info;
763 pid = proc_pid(inode);
764 task = get_pid_task(pid, PIDTYPE_PID);
765 if (!task)
766 return -ESRCH;
767
768 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
769
770 put_task_struct(task);
771 return ret;
772}
773
774static int proc_single_open(struct inode *inode, struct file *filp)
775{
c6a34058 776 return single_open(filp, proc_single_show, inode);
be614086
EB		 777}
778
779static const struct file_operations proc_single_file_operations = {
780 .open = proc_single_open,
781 .read = seq_read,
782 .llseek = seq_lseek,
783 .release = single_release,
784};
785
5381e169
ON		 786
787struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
1da177e4 788{
5381e169
ON		 789 struct task_struct *task = get_proc_task(inode);
790 struct mm_struct *mm = ERR_PTR(-ESRCH);
e268337d 791
5381e169 792 if (task) {
caaee623 793 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
5381e169 794 put_task_struct(task);
e268337d 795
5381e169
ON		 796 if (!IS_ERR_OR_NULL(mm)) {
797 /* ensure this mm_struct can't be freed */
798 atomic_inc(&mm->mm_count);
799 /* but do not pin its memory */
800 mmput(mm);
801 }
802 }
803
804 return mm;
805}
806
807static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
808{
809 struct mm_struct *mm = proc_mem_open(inode, mode);
e268337d
LT		 810
811 if (IS_ERR(mm))
812 return PTR_ERR(mm);
813
e268337d 814 file->private_data = mm;
1da177e4
LT		 815 return 0;
816}
817
b409e578
CW		 818static int mem_open(struct inode *inode, struct file *file)
819{
bc452b4b
DH		 820 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
821
822 /* OK to pass negative loff_t, we can catch out-of-range */
823 file->f_mode |= FMODE_UNSIGNED_OFFSET;
824
825 return ret;
b409e578
CW		 826}
827
572d34b9
ON		 828static ssize_t mem_rw(struct file *file, char __user *buf,
829 size_t count, loff_t *ppos, int write)
1da177e4 830{
e268337d 831 struct mm_struct *mm = file->private_data;
572d34b9
ON		 832 unsigned long addr = *ppos;
833 ssize_t copied;
1da177e4 834 char *page;
272ddc8b 835 unsigned int flags;
1da177e4 836
e268337d
LT		 837 if (!mm)
838 return 0;
99f89551 839
30cd8903
KM		 840 page = (char *)__get_free_page(GFP_TEMPORARY);
841 if (!page)
e268337d 842 return -ENOMEM;
1da177e4 843
f7ca54f4 844 copied = 0;
6d08f2c7
ON		 845 if (!atomic_inc_not_zero(&mm->mm_users))
846 goto free;
847
272ddc8b
LT		 848 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */
849 flags = FOLL_FORCE;
6347e8d5
LS		 850 if (write)
851 flags |= FOLL_WRITE;
852
1da177e4 853 while (count > 0) {
572d34b9 854 int this_len = min_t(int, count, PAGE_SIZE);
1da177e4 855
572d34b9 856 if (write && copy_from_user(page, buf, this_len)) {
1da177e4
LT		 857 copied = -EFAULT;
858 break;
859 }
572d34b9 860
6347e8d5 861 this_len = access_remote_vm(mm, addr, page, this_len, flags);
572d34b9 862 if (!this_len) {
1da177e4
LT		 863 if (!copied)
864 copied = -EIO;
865 break;
866 }
572d34b9
ON		 867
868 if (!write && copy_to_user(buf, page, this_len)) {
869 copied = -EFAULT;
870 break;
871 }
872
873 buf += this_len;
874 addr += this_len;
875 copied += this_len;
876 count -= this_len;
1da177e4 877 }
572d34b9 878 *ppos = addr;
30cd8903 879
6d08f2c7
ON		 880 mmput(mm);
881free:
30cd8903 882 free_page((unsigned long) page);
1da177e4
LT		 883 return copied;
884}
1da177e4 885
572d34b9
ON		 886static ssize_t mem_read(struct file *file, char __user *buf,
887 size_t count, loff_t *ppos)
888{
889 return mem_rw(file, buf, count, ppos, 0);
890}
891
892static ssize_t mem_write(struct file *file, const char __user *buf,
893 size_t count, loff_t *ppos)
894{
895 return mem_rw(file, (char __user*)buf, count, ppos, 1);
896}
897
85863e47 898loff_t mem_lseek(struct file *file, loff_t offset, int orig)
1da177e4
LT		 899{
900 switch (orig) {
901 case 0:
902 file->f_pos = offset;
903 break;
904 case 1:
905 file->f_pos += offset;
906 break;
907 default:
908 return -EINVAL;
909 }
910 force_successful_syscall_return();
911 return file->f_pos;
912}
913
e268337d
LT		 914static int mem_release(struct inode *inode, struct file *file)
915{
916 struct mm_struct *mm = file->private_data;
71879d3c 917 if (mm)
6d08f2c7 918 mmdrop(mm);
e268337d
LT		 919 return 0;
920}
921
00977a59 922static const struct file_operations proc_mem_operations = {
1da177e4
LT		 923 .llseek = mem_lseek,
924 .read = mem_read,
925 .write = mem_write,
926 .open = mem_open,
e268337d 927 .release = mem_release,
1da177e4
LT		 928};
929
b409e578
CW		 930static int environ_open(struct inode *inode, struct file *file)
931{
932 return __mem_open(inode, file, PTRACE_MODE_READ);
933}
934
315e28c8
JP		 935static ssize_t environ_read(struct file *file, char __user *buf,
936 size_t count, loff_t *ppos)
937{
315e28c8
JP		 938 char *page;
939 unsigned long src = *ppos;
b409e578
CW		 940 int ret = 0;
941 struct mm_struct *mm = file->private_data;
a3b609ef 942 unsigned long env_start, env_end;
315e28c8 943
8148a73c
MK		 944 /* Ensure the process spawned far enough to have an environment. */
945 if (!mm || !mm->env_end)
b409e578 946 return 0;
315e28c8 947
315e28c8
JP		 948 page = (char *)__get_free_page(GFP_TEMPORARY);
949 if (!page)
b409e578 950 return -ENOMEM;
315e28c8 951
d6f64b89 952 ret = 0;
b409e578
CW		 953 if (!atomic_inc_not_zero(&mm->mm_users))
954 goto free;
a3b609ef
MG		 955
956 down_read(&mm->mmap_sem);
957 env_start = mm->env_start;
958 env_end = mm->env_end;
959 up_read(&mm->mmap_sem);
960
315e28c8 961 while (count > 0) {
e8905ec2
DH		 962 size_t this_len, max_len;
963 int retval;
315e28c8 964
a3b609ef 965 if (src >= (env_end - env_start))
315e28c8
JP		 966 break;
967
a3b609ef 968 this_len = env_end - (env_start + src);
e8905ec2
DH		 969
970 max_len = min_t(size_t, PAGE_SIZE, count);
971 this_len = min(max_len, this_len);
315e28c8 972
272ddc8b 973 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
315e28c8
JP		 974
975 if (retval <= 0) {
976 ret = retval;
977 break;
978 }
979
980 if (copy_to_user(buf, page, retval)) {
981 ret = -EFAULT;
982 break;
983 }
984
985 ret += retval;
986 src += retval;
987 buf += retval;
988 count -= retval;
989 }
990 *ppos = src;
315e28c8 991 mmput(mm);
b409e578
CW		 992
993free:
315e28c8 994 free_page((unsigned long) page);
315e28c8
JP		 995 return ret;
996}
997
998static const struct file_operations proc_environ_operations = {
b409e578 999 .open = environ_open,
315e28c8 1000 .read = environ_read,
87df8424 1001 .llseek = generic_file_llseek,
b409e578 1002 .release = mem_release,
315e28c8
JP		 1003};
1004
c5317167
AV		 1005static int auxv_open(struct inode *inode, struct file *file)
1006{
1007 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1008}
1009
1010static ssize_t auxv_read(struct file *file, char __user *buf,
1011 size_t count, loff_t *ppos)
1012{
1013 struct mm_struct *mm = file->private_data;
1014 unsigned int nwords = 0;
06b2849d
LY		 1015
1016 if (!mm)
1017 return 0;
c5317167
AV		 1018 do {
1019 nwords += 2;
1020 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1021 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1022 nwords * sizeof(mm->saved_auxv[0]));
1023}
1024
1025static const struct file_operations proc_auxv_operations = {
1026 .open = auxv_open,
1027 .read = auxv_read,
1028 .llseek = generic_file_llseek,
1029 .release = mem_release,
1030};
1031
fa0cbbf1
DR		 1032static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1033 loff_t *ppos)
1034{
496ad9aa 1035 struct task_struct *task = get_proc_task(file_inode(file));
fa0cbbf1
DR		 1036 char buffer[PROC_NUMBUF];
1037 int oom_adj = OOM_ADJUST_MIN;
1038 size_t len;
fa0cbbf1
DR		 1039
1040 if (!task)
1041 return -ESRCH;
f913da59
MH		 1042 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1043 oom_adj = OOM_ADJUST_MAX;
1044 else
1045 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1046 OOM_SCORE_ADJ_MAX;
fa0cbbf1
DR		 1047 put_task_struct(task);
1048 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1049 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1050}
1051
1d5f0acb
MH		 1052static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1053{
1054 static DEFINE_MUTEX(oom_adj_mutex);
44a70ade 1055 struct mm_struct *mm = NULL;
1d5f0acb
MH		 1056 struct task_struct *task;
1057 int err = 0;
1058
1059 task = get_proc_task(file_inode(file));
1060 if (!task)
1061 return -ESRCH;
1062
1063 mutex_lock(&oom_adj_mutex);
1064 if (legacy) {
1065 if (oom_adj < task->signal->oom_score_adj &&
1066 !capable(CAP_SYS_RESOURCE)) {
1067 err = -EACCES;
1068 goto err_unlock;
1069 }
1070 /*
1071 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1072 * /proc/pid/oom_score_adj instead.
1073 */
1074 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1075 current->comm, task_pid_nr(current), task_pid_nr(task),
1076 task_pid_nr(task));
1077 } else {
1078 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1079 !capable(CAP_SYS_RESOURCE)) {
1080 err = -EACCES;
1081 goto err_unlock;
1082 }
1083 }
1084
44a70ade
MH		 1085 /*
1086 * Make sure we will check other processes sharing the mm if this is
1087 * not vfrok which wants its own oom_score_adj.
1088 * pin the mm so it doesn't go away and get reused after task_unlock
1089 */
1090 if (!task->vfork_done) {
1091 struct task_struct *p = find_lock_task_mm(task);
1092
1093 if (p) {
1094 if (atomic_read(&p->mm->mm_users) > 1) {
1095 mm = p->mm;
1096 atomic_inc(&mm->mm_count);
1097 }
1098 task_unlock(p);
1099 }
1100 }
1101
1d5f0acb
MH		 1102 task->signal->oom_score_adj = oom_adj;
1103 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1104 task->signal->oom_score_adj_min = (short)oom_adj;
1105 trace_oom_score_adj_update(task);
44a70ade
MH		 1106
1107 if (mm) {
1108 struct task_struct *p;
1109
1110 rcu_read_lock();
1111 for_each_process(p) {
1112 if (same_thread_group(task, p))
1113 continue;
1114
1115 /* do not touch kernel threads or the global init */
1116 if (p->flags & PF_KTHREAD || is_global_init(p))
1117 continue;
1118
1119 task_lock(p);
1120 if (!p->vfork_done && process_shares_mm(p, mm)) {
1121 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1122 task_pid_nr(p), p->comm,
1123 p->signal->oom_score_adj, oom_adj,
1124 task_pid_nr(task), task->comm);
1125 p->signal->oom_score_adj = oom_adj;
1126 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1127 p->signal->oom_score_adj_min = (short)oom_adj;
1128 }
1129 task_unlock(p);
1130 }
1131 rcu_read_unlock();
1132 mmdrop(mm);
1133 }
1d5f0acb
MH		 1134err_unlock:
1135 mutex_unlock(&oom_adj_mutex);
1136 put_task_struct(task);
1137 return err;
1138}
f913da59 1139
b72bdfa7
DR		 1140/*
1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1142 * kernels. The effective policy is defined by oom_score_adj, which has a
1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1145 * Processes that become oom disabled via oom_adj will still be oom disabled
1146 * with this implementation.
1147 *
1148 * oom_adj cannot be removed since existing userspace binaries use it.
1149 */
fa0cbbf1
DR		 1150static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1151 size_t count, loff_t *ppos)
1152{
fa0cbbf1
DR		 1153 char buffer[PROC_NUMBUF];
1154 int oom_adj;
fa0cbbf1
DR		 1155 int err;
1156
1157 memset(buffer, 0, sizeof(buffer));
1158 if (count > sizeof(buffer) - 1)
1159 count = sizeof(buffer) - 1;
1160 if (copy_from_user(buffer, buf, count)) {
1161 err = -EFAULT;
1162 goto out;
1163 }
1164
1165 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1166 if (err)
1167 goto out;
1168 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1169 oom_adj != OOM_DISABLE) {
1170 err = -EINVAL;
1171 goto out;
1172 }
1173
fa0cbbf1
DR		 1174 /*
1175 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1176 * value is always attainable.
1177 */
1178 if (oom_adj == OOM_ADJUST_MAX)
1179 oom_adj = OOM_SCORE_ADJ_MAX;
1180 else
1181 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1182
1d5f0acb 1183 err = __set_oom_adj(file, oom_adj, true);
fa0cbbf1
DR		 1184out:
1185 return err < 0 ? err : count;
1186}
1187
1188static const struct file_operations proc_oom_adj_operations = {
1189 .read = oom_adj_read,
1190 .write = oom_adj_write,
1191 .llseek = generic_file_llseek,
1192};
1193
a63d83f4
DR		 1194static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1195 size_t count, loff_t *ppos)
1196{
496ad9aa 1197 struct task_struct *task = get_proc_task(file_inode(file));
a63d83f4 1198 char buffer[PROC_NUMBUF];
a9c58b90 1199 short oom_score_adj = OOM_SCORE_ADJ_MIN;
a63d83f4
DR		 1200 size_t len;
1201
1202 if (!task)
1203 return -ESRCH;
f913da59 1204 oom_score_adj = task->signal->oom_score_adj;
a63d83f4 1205 put_task_struct(task);
a9c58b90 1206 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
a63d83f4
DR		 1207 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1208}
1209
1210static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1211 size_t count, loff_t *ppos)
1212{
a63d83f4 1213 char buffer[PROC_NUMBUF];
0a8cb8e3 1214 int oom_score_adj;
a63d83f4
DR		 1215 int err;
1216
1217 memset(buffer, 0, sizeof(buffer));
1218 if (count > sizeof(buffer) - 1)
1219 count = sizeof(buffer) - 1;
723548bf
DR		 1220 if (copy_from_user(buffer, buf, count)) {
1221 err = -EFAULT;
1222 goto out;
1223 }
a63d83f4 1224
0a8cb8e3 1225 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
a63d83f4 1226 if (err)
723548bf 1227 goto out;
a63d83f4 1228 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
723548bf
DR		 1229 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1230 err = -EINVAL;
1231 goto out;
1232 }
a63d83f4 1233
1d5f0acb 1234 err = __set_oom_adj(file, oom_score_adj, false);
723548bf
DR		 1235out:
1236 return err < 0 ? err : count;
a63d83f4
DR		 1237}
1238
1239static const struct file_operations proc_oom_score_adj_operations = {
1240 .read = oom_score_adj_read,
1241 .write = oom_score_adj_write,
6038f373 1242 .llseek = default_llseek,
a63d83f4
DR		 1243};
1244
1da177e4
LT		 1245#ifdef CONFIG_AUDITSYSCALL
1246#define TMPBUFLEN 21
1247static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1248 size_t count, loff_t *ppos)
1249{
496ad9aa 1250 struct inode * inode = file_inode(file);
99f89551 1251 struct task_struct *task = get_proc_task(inode);
1da177e4
LT		 1252 ssize_t length;
1253 char tmpbuf[TMPBUFLEN];
1254
99f89551
EB		 1255 if (!task)
1256 return -ESRCH;
1da177e4 1257 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
e1760bd5
EB		 1258 from_kuid(file->f_cred->user_ns,
1259 audit_get_loginuid(task)));
99f89551 1260 put_task_struct(task);
1da177e4
LT		 1261 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1262}
1263
1264static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1265 size_t count, loff_t *ppos)
1266{
496ad9aa 1267 struct inode * inode = file_inode(file);
1da177e4 1268 uid_t loginuid;
e1760bd5 1269 kuid_t kloginuid;
774636e1 1270 int rv;
1da177e4 1271
7dc52157
PM		 1272 rcu_read_lock();
1273 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1274 rcu_read_unlock();
1da177e4 1275 return -EPERM;
7dc52157
PM		 1276 }
1277 rcu_read_unlock();
1da177e4 1278
1da177e4
LT		 1279 if (*ppos != 0) {
1280 /* No partial writes. */
1281 return -EINVAL;
1282 }
1da177e4 1283
774636e1
AD		 1284 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1285 if (rv < 0)
1286 return rv;
81407c84
EP		 1287
1288 /* is userspace tring to explicitly UNSET the loginuid? */
1289 if (loginuid == AUDIT_UID_UNSET) {
1290 kloginuid = INVALID_UID;
1291 } else {
1292 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
774636e1
AD		 1293 if (!uid_valid(kloginuid))
1294 return -EINVAL;
e1760bd5
EB		 1295 }
1296
774636e1
AD		 1297 rv = audit_set_loginuid(kloginuid);
1298 if (rv < 0)
1299 return rv;
1300 return count;
1da177e4
LT		 1301}
1302
00977a59 1303static const struct file_operations proc_loginuid_operations = {
1da177e4
LT		 1304 .read = proc_loginuid_read,
1305 .write = proc_loginuid_write,
87df8424 1306 .llseek = generic_file_llseek,
1da177e4 1307};
1e0bd755
EP		 1308
1309static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1310 size_t count, loff_t *ppos)
1311{
496ad9aa 1312 struct inode * inode = file_inode(file);
1e0bd755
EP		 1313 struct task_struct *task = get_proc_task(inode);
1314 ssize_t length;
1315 char tmpbuf[TMPBUFLEN];
1316
1317 if (!task)
1318 return -ESRCH;
1319 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1320 audit_get_sessionid(task));
1321 put_task_struct(task);
1322 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1323}
1324
1325static const struct file_operations proc_sessionid_operations = {
1326 .read = proc_sessionid_read,
87df8424 1327 .llseek = generic_file_llseek,
1e0bd755 1328};
1da177e4
LT		 1329#endif
1330
f4f154fd
AM		 1331#ifdef CONFIG_FAULT_INJECTION
1332static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1333 size_t count, loff_t *ppos)
1334{
496ad9aa 1335 struct task_struct *task = get_proc_task(file_inode(file));
f4f154fd
AM		 1336 char buffer[PROC_NUMBUF];
1337 size_t len;
1338 int make_it_fail;
f4f154fd
AM		 1339
1340 if (!task)
1341 return -ESRCH;
1342 make_it_fail = task->make_it_fail;
1343 put_task_struct(task);
1344
1345 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
0c28f287
AM		 1346
1347 return simple_read_from_buffer(buf, count, ppos, buffer, len);
f4f154fd
AM		 1348}
1349
1350static ssize_t proc_fault_inject_write(struct file * file,
1351 const char __user * buf, size_t count, loff_t *ppos)
1352{
1353 struct task_struct *task;
774636e1 1354 char buffer[PROC_NUMBUF];
f4f154fd 1355 int make_it_fail;
774636e1 1356 int rv;
f4f154fd
AM		 1357
1358 if (!capable(CAP_SYS_RESOURCE))
1359 return -EPERM;
1360 memset(buffer, 0, sizeof(buffer));
1361 if (count > sizeof(buffer) - 1)
1362 count = sizeof(buffer) - 1;
1363 if (copy_from_user(buffer, buf, count))
1364 return -EFAULT;
774636e1
AD		 1365 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1366 if (rv < 0)
1367 return rv;
16caed31
DJ		 1368 if (make_it_fail < 0 || make_it_fail > 1)
1369 return -EINVAL;
1370
496ad9aa 1371 task = get_proc_task(file_inode(file));
f4f154fd
AM		 1372 if (!task)
1373 return -ESRCH;
1374 task->make_it_fail = make_it_fail;
1375 put_task_struct(task);
cba8aafe
VL		 1376
1377 return count;
f4f154fd
AM		 1378}
1379
00977a59 1380static const struct file_operations proc_fault_inject_operations = {
f4f154fd
AM		 1381 .read = proc_fault_inject_read,
1382 .write = proc_fault_inject_write,
87df8424 1383 .llseek = generic_file_llseek,
f4f154fd
AM		 1384};
1385#endif
1386
9745512c 1387
43ae34cb
IM		 1388#ifdef CONFIG_SCHED_DEBUG
1389/*
1390 * Print out various scheduling related per-task fields:
1391 */
1392static int sched_show(struct seq_file *m, void *v)
1393{
1394 struct inode *inode = m->private;
1395 struct task_struct *p;
1396
43ae34cb
IM		 1397 p = get_proc_task(inode);
1398 if (!p)
1399 return -ESRCH;
1400 proc_sched_show_task(p, m);
1401
1402 put_task_struct(p);
1403
1404 return 0;
1405}
1406
1407static ssize_t
1408sched_write(struct file *file, const char __user *buf,
1409 size_t count, loff_t *offset)
1410{
496ad9aa 1411 struct inode *inode = file_inode(file);
43ae34cb
IM		 1412 struct task_struct *p;
1413
43ae34cb
IM		 1414 p = get_proc_task(inode);
1415 if (!p)
1416 return -ESRCH;
1417 proc_sched_set_task(p);
1418
1419 put_task_struct(p);
1420
1421 return count;
1422}
1423
1424static int sched_open(struct inode *inode, struct file *filp)
1425{
c6a34058 1426 return single_open(filp, sched_show, inode);
43ae34cb
IM		 1427}
1428
1429static const struct file_operations proc_pid_sched_operations = {
1430 .open = sched_open,
1431 .read = seq_read,
1432 .write = sched_write,
1433 .llseek = seq_lseek,
5ea473a1 1434 .release = single_release,
43ae34cb
IM		 1435};
1436
1437#endif
1438
5091faa4
MG		 1439#ifdef CONFIG_SCHED_AUTOGROUP
1440/*
1441 * Print out autogroup related information:
1442 */
1443static int sched_autogroup_show(struct seq_file *m, void *v)
1444{
1445 struct inode *inode = m->private;
1446 struct task_struct *p;
1447
1448 p = get_proc_task(inode);
1449 if (!p)
1450 return -ESRCH;
1451 proc_sched_autogroup_show_task(p, m);
1452
1453 put_task_struct(p);
1454
1455 return 0;
1456}
1457
1458static ssize_t
1459sched_autogroup_write(struct file *file, const char __user *buf,
1460 size_t count, loff_t *offset)
1461{
496ad9aa 1462 struct inode *inode = file_inode(file);
5091faa4
MG		 1463 struct task_struct *p;
1464 char buffer[PROC_NUMBUF];
0a8cb8e3 1465 int nice;
5091faa4
MG		 1466 int err;
1467
1468 memset(buffer, 0, sizeof(buffer));
1469 if (count > sizeof(buffer) - 1)
1470 count = sizeof(buffer) - 1;
1471 if (copy_from_user(buffer, buf, count))
1472 return -EFAULT;
1473
0a8cb8e3
AD		 1474 err = kstrtoint(strstrip(buffer), 0, &nice);
1475 if (err < 0)
1476 return err;
5091faa4
MG		 1477
1478 p = get_proc_task(inode);
1479 if (!p)
1480 return -ESRCH;
1481
2e5b5b3a 1482 err = proc_sched_autogroup_set_nice(p, nice);
5091faa4
MG		 1483 if (err)
1484 count = err;
1485
1486 put_task_struct(p);
1487
1488 return count;
1489}
1490
1491static int sched_autogroup_open(struct inode *inode, struct file *filp)
1492{
1493 int ret;
1494
1495 ret = single_open(filp, sched_autogroup_show, NULL);
1496 if (!ret) {
1497 struct seq_file *m = filp->private_data;
1498
1499 m->private = inode;
1500 }
1501 return ret;
1502}
1503
1504static const struct file_operations proc_pid_sched_autogroup_operations = {
1505 .open = sched_autogroup_open,
1506 .read = seq_read,
1507 .write = sched_autogroup_write,
1508 .llseek = seq_lseek,
1509 .release = single_release,
1510};
1511
1512#endif /* CONFIG_SCHED_AUTOGROUP */
1513
4614a696 1514static ssize_t comm_write(struct file *file, const char __user *buf,
1515 size_t count, loff_t *offset)
1516{
496ad9aa 1517 struct inode *inode = file_inode(file);
4614a696 1518 struct task_struct *p;
1519 char buffer[TASK_COMM_LEN];
830e0fc9 1520 const size_t maxlen = sizeof(buffer) - 1;
4614a696 1521
1522 memset(buffer, 0, sizeof(buffer));
830e0fc9 1523 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
4614a696 1524 return -EFAULT;
1525
1526 p = get_proc_task(inode);
1527 if (!p)
1528 return -ESRCH;
1529
1530 if (same_thread_group(current, p))
1531 set_task_comm(p, buffer);
1532 else
1533 count = -EINVAL;
1534
1535 put_task_struct(p);
1536
1537 return count;
1538}
1539
1540static int comm_show(struct seq_file *m, void *v)
1541{
1542 struct inode *inode = m->private;
1543 struct task_struct *p;
1544
1545 p = get_proc_task(inode);
1546 if (!p)
1547 return -ESRCH;
1548
1549 task_lock(p);
1550 seq_printf(m, "%s\n", p->comm);
1551 task_unlock(p);
1552
1553 put_task_struct(p);
1554
1555 return 0;
1556}
1557
1558static int comm_open(struct inode *inode, struct file *filp)
1559{
c6a34058 1560 return single_open(filp, comm_show, inode);
4614a696 1561}
1562
1563static const struct file_operations proc_pid_set_comm_operations = {
1564 .open = comm_open,
1565 .read = seq_read,
1566 .write = comm_write,
1567 .llseek = seq_lseek,
1568 .release = single_release,
1569};
1570
7773fbc5 1571static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
925d1c40
MH		 1572{
1573 struct task_struct *task;
925d1c40
MH		 1574 struct file *exe_file;
1575
2b0143b5 1576 task = get_proc_task(d_inode(dentry));
925d1c40
MH		 1577 if (!task)
1578 return -ENOENT;
cd81a917 1579 exe_file = get_task_exe_file(task);
925d1c40 1580 put_task_struct(task);
925d1c40
MH		 1581 if (exe_file) {
1582 *exe_path = exe_file->f_path;
1583 path_get(&exe_file->f_path);
1584 fput(exe_file);
1585 return 0;
1586 } else
1587 return -ENOENT;
1588}
1589
6b255391 1590static const char *proc_pid_get_link(struct dentry *dentry,
fceef393
AV		 1591 struct inode *inode,
1592 struct delayed_call *done)
1da177e4 1593{
408ef013 1594 struct path path;
1da177e4
LT		 1595 int error = -EACCES;
1596
6b255391
AV		 1597 if (!dentry)
1598 return ERR_PTR(-ECHILD);
1599
778c1144
EB		 1600 /* Are we allowed to snoop on the tasks file descriptors? */
1601 if (!proc_fd_access_allowed(inode))
1da177e4 1602 goto out;
1da177e4 1603
408ef013
CH		 1604 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1605 if (error)
1606 goto out;
1607
6e77137b 1608 nd_jump_link(&path);
408ef013 1609 return NULL;
1da177e4 1610out:
008b150a 1611 return ERR_PTR(error);
1da177e4
LT		 1612}
1613
3dcd25f3 1614static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1da177e4 1615{
e12ba74d 1616 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
3dcd25f3 1617 char *pathname;
1da177e4
LT		 1618 int len;
1619
1620 if (!tmp)
1621 return -ENOMEM;
0c28f287 1622
7b2a69ba 1623 pathname = d_path(path, tmp, PAGE_SIZE);
3dcd25f3
JB		 1624 len = PTR_ERR(pathname);
1625 if (IS_ERR(pathname))
1da177e4 1626 goto out;
3dcd25f3 1627 len = tmp + PAGE_SIZE - 1 - pathname;
1da177e4
LT		 1628
1629 if (len > buflen)
1630 len = buflen;
3dcd25f3 1631 if (copy_to_user(buffer, pathname, len))
1da177e4
LT		 1632 len = -EFAULT;
1633 out:
1634 free_page((unsigned long)tmp);
1635 return len;
1636}
1637
1638static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1639{
1640 int error = -EACCES;
2b0143b5 1641 struct inode *inode = d_inode(dentry);
3dcd25f3 1642 struct path path;
1da177e4 1643
778c1144
EB		 1644 /* Are we allowed to snoop on the tasks file descriptors? */
1645 if (!proc_fd_access_allowed(inode))
1da177e4 1646 goto out;
1da177e4 1647
7773fbc5 1648 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1da177e4
LT		 1649 if (error)
1650 goto out;
1651
3dcd25f3
JB		 1652 error = do_proc_readlink(&path, buffer, buflen);
1653 path_put(&path);
1da177e4 1654out:
1da177e4
LT		 1655 return error;
1656}
1657
faf60af1 1658const struct inode_operations proc_pid_link_inode_operations = {
1da177e4 1659 .readlink = proc_pid_readlink,
6b255391 1660 .get_link = proc_pid_get_link,
6d76fa58 1661 .setattr = proc_setattr,
1da177e4
LT		 1662};
1663
28a6d671
EB		 1664
1665/* building an inode */
1666
6b4e306a 1667struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
28a6d671
EB		 1668{
1669 struct inode * inode;
1670 struct proc_inode *ei;
c69e8d9c 1671 const struct cred *cred;
1da177e4 1672
28a6d671 1673 /* We need a new inode */
1da177e4 1674
28a6d671
EB		 1675 inode = new_inode(sb);
1676 if (!inode)
1677 goto out;
1678
1679 /* Common stuff */
1680 ei = PROC_I(inode);
85fe4025 1681 inode->i_ino = get_next_ino();
078cd827 1682 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
28a6d671
EB		 1683 inode->i_op = &proc_def_inode_operations;
1684
1685 /*
1686 * grab the reference to task.
1687 */
1a657f78 1688 ei->pid = get_task_pid(task, PIDTYPE_PID);
28a6d671
EB		 1689 if (!ei->pid)
1690 goto out_unlock;
1691
28a6d671 1692 if (task_dumpable(task)) {
c69e8d9c
DH		 1693 rcu_read_lock();
1694 cred = __task_cred(task);
1695 inode->i_uid = cred->euid;
1696 inode->i_gid = cred->egid;
1697 rcu_read_unlock();
1da177e4 1698 }
28a6d671
EB		 1699 security_task_to_inode(task, inode);
1700
1da177e4 1701out:
28a6d671
EB		 1702 return inode;
1703
1704out_unlock:
1705 iput(inode);
1706 return NULL;
1da177e4
LT		 1707}
1708
6b4e306a 1709int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1da177e4 1710{
2b0143b5 1711 struct inode *inode = d_inode(dentry);
28a6d671 1712 struct task_struct *task;
c69e8d9c 1713 const struct cred *cred;
0499680a 1714 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
c69e8d9c 1715
28a6d671 1716 generic_fillattr(inode, stat);
1da177e4 1717
28a6d671 1718 rcu_read_lock();
dcb0f222
EB		 1719 stat->uid = GLOBAL_ROOT_UID;
1720 stat->gid = GLOBAL_ROOT_GID;
28a6d671
EB		 1721 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1722 if (task) {
0499680a
VK		 1723 if (!has_pid_permissions(pid, task, 2)) {
1724 rcu_read_unlock();
1725 /*
1726 * This doesn't prevent learning whether PID exists,
1727 * it only makes getattr() consistent with readdir().
1728 */
1729 return -ENOENT;
1730 }
28a6d671
EB		 1731 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1732 task_dumpable(task)) {
c69e8d9c
DH		 1733 cred = __task_cred(task);
1734 stat->uid = cred->euid;
1735 stat->gid = cred->egid;
1da177e4
LT		 1736 }
1737 }
28a6d671 1738 rcu_read_unlock();
d6e71144 1739 return 0;
1da177e4
LT		 1740}
1741
1da177e4
LT		 1742/* dentry stuff */
1743
1744/*
1745 * Exceptional case: normally we are not allowed to unhash a busy
1746 * directory. In this case, however, we can do it - no aliasing problems
1747 * due to the way we treat inodes.
1748 *
1749 * Rewrite the inode's ownerships here because the owning task may have
1750 * performed a setuid(), etc.
99f89551
EB		 1751 *
1752 * Before the /proc/pid/status file was created the only way to read
1753 * the effective uid of a /process was to stat /proc/pid. Reading
1754 * /proc/pid/status is slow enough that procps and other packages
1755 * kept stating /proc/pid. To keep the rules in /proc simple I have
1756 * made this apply to all per process world readable and executable
1757 * directories.
1da177e4 1758 */
0b728e19 1759int pid_revalidate(struct dentry *dentry, unsigned int flags)
1da177e4 1760{
34286d66
NP		 1761 struct inode *inode;
1762 struct task_struct *task;
c69e8d9c
DH		 1763 const struct cred *cred;
1764
0b728e19 1765 if (flags & LOOKUP_RCU)
34286d66
NP		 1766 return -ECHILD;
1767
2b0143b5 1768 inode = d_inode(dentry);
34286d66
NP		 1769 task = get_proc_task(inode);
1770
99f89551
EB		 1771 if (task) {
1772 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1773 task_dumpable(task)) {
c69e8d9c
DH		 1774 rcu_read_lock();
1775 cred = __task_cred(task);
1776 inode->i_uid = cred->euid;
1777 inode->i_gid = cred->egid;
1778 rcu_read_unlock();
1da177e4 1779 } else {
dcb0f222
EB		 1780 inode->i_uid = GLOBAL_ROOT_UID;
1781 inode->i_gid = GLOBAL_ROOT_GID;
1da177e4 1782 }
9ee8ab9f 1783 inode->i_mode &= ~(S_ISUID | S_ISGID);
1da177e4 1784 security_task_to_inode(task, inode);
99f89551 1785 put_task_struct(task);
1da177e4
LT		 1786 return 1;
1787 }
1da177e4
LT		 1788 return 0;
1789}
1790
d855a4b7
ON		 1791static inline bool proc_inode_is_dead(struct inode *inode)
1792{
1793 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1794}
1795
1dd704b6
DH		 1796int pid_delete_dentry(const struct dentry *dentry)
1797{
1798 /* Is the task we represent dead?
1799 * If so, then don't put the dentry on the lru list,
1800 * kill it immediately.
1801 */
2b0143b5 1802 return proc_inode_is_dead(d_inode(dentry));
1dd704b6
DH		 1803}
1804
6b4e306a 1805const struct dentry_operations pid_dentry_operations =
28a6d671
EB		 1806{
1807 .d_revalidate = pid_revalidate,
1808 .d_delete = pid_delete_dentry,
1809};
1810
1811/* Lookups */
1812
1c0d04c9
EB		 1813/*
1814 * Fill a directory entry.
1815 *
1816 * If possible create the dcache entry and derive our inode number and
1817 * file type from dcache entry.
1818 *
1819 * Since all of the proc inode numbers are dynamically generated, the inode
1820 * numbers do not exist until the inode is cache. This means creating the
1821 * the dcache entry in readdir is necessary to keep the inode numbers
1822 * reported by readdir in sync with the inode numbers reported
1823 * by stat.
1824 */
f0c3b509 1825bool proc_fill_cache(struct file *file, struct dir_context *ctx,
6b4e306a 1826 const char *name, int len,
c5141e6d 1827 instantiate_t instantiate, struct task_struct *task, const void *ptr)
61a28784 1828{
f0c3b509 1829 struct dentry *child, *dir = file->f_path.dentry;
1df98b8b 1830 struct qstr qname = QSTR_INIT(name, len);
61a28784 1831 struct inode *inode;
1df98b8b
AV		 1832 unsigned type;
1833 ino_t ino;
61a28784 1834
1df98b8b 1835 child = d_hash_and_lookup(dir, &qname);
61a28784 1836 if (!child) {
3781764b
AV		 1837 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1838 child = d_alloc_parallel(dir, &qname, &wq);
1839 if (IS_ERR(child))
1df98b8b 1840 goto end_instantiate;
3781764b
AV		 1841 if (d_in_lookup(child)) {
1842 int err = instantiate(d_inode(dir), child, task, ptr);
1843 d_lookup_done(child);
1844 if (err < 0) {
1845 dput(child);
1846 goto end_instantiate;
1847 }
61a28784
EB		 1848 }
1849 }
2b0143b5 1850 inode = d_inode(child);
147ce699
AV		 1851 ino = inode->i_ino;
1852 type = inode->i_mode >> 12;
61a28784 1853 dput(child);
f0c3b509 1854 return dir_emit(ctx, name, len, ino, type);
1df98b8b
AV		 1855
1856end_instantiate:
1857 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
61a28784
EB		 1858}
1859
640708a2
PE		 1860/*
1861 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1862 * which represent vma start and end addresses.
1863 */
1864static int dname_to_vma_addr(struct dentry *dentry,
1865 unsigned long *start, unsigned long *end)
1866{
1867 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1868 return -EINVAL;
1869
1870 return 0;
1871}
1872
0b728e19 1873static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
640708a2
PE		 1874{
1875 unsigned long vm_start, vm_end;
1876 bool exact_vma_exists = false;
1877 struct mm_struct *mm = NULL;
1878 struct task_struct *task;
1879 const struct cred *cred;
1880 struct inode *inode;
1881 int status = 0;
1882
0b728e19 1883 if (flags & LOOKUP_RCU)
640708a2
PE		 1884 return -ECHILD;
1885
2b0143b5 1886 inode = d_inode(dentry);
640708a2
PE		 1887 task = get_proc_task(inode);
1888 if (!task)
1889 goto out_notask;
1890
caaee623 1891 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2344bec7 1892 if (IS_ERR_OR_NULL(mm))
640708a2
PE		 1893 goto out;
1894
1895 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1896 down_read(&mm->mmap_sem);
1897 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1898 up_read(&mm->mmap_sem);
1899 }
1900
1901 mmput(mm);
1902
1903 if (exact_vma_exists) {
1904 if (task_dumpable(task)) {
1905 rcu_read_lock();
1906 cred = __task_cred(task);
1907 inode->i_uid = cred->euid;
1908 inode->i_gid = cred->egid;
1909 rcu_read_unlock();
1910 } else {
dcb0f222
EB		 1911 inode->i_uid = GLOBAL_ROOT_UID;
1912 inode->i_gid = GLOBAL_ROOT_GID;
640708a2
PE		 1913 }
1914 security_task_to_inode(task, inode);
1915 status = 1;
1916 }
1917
1918out:
1919 put_task_struct(task);
1920
1921out_notask:
640708a2
PE		 1922 return status;
1923}
1924
1925static const struct dentry_operations tid_map_files_dentry_operations = {
1926 .d_revalidate = map_files_d_revalidate,
1927 .d_delete = pid_delete_dentry,
1928};
1929
6b255391 1930static int map_files_get_link(struct dentry *dentry, struct path *path)
640708a2
PE		 1931{
1932 unsigned long vm_start, vm_end;
1933 struct vm_area_struct *vma;
1934 struct task_struct *task;
1935 struct mm_struct *mm;
1936 int rc;
1937
1938 rc = -ENOENT;
2b0143b5 1939 task = get_proc_task(d_inode(dentry));
640708a2
PE		 1940 if (!task)
1941 goto out;
1942
1943 mm = get_task_mm(task);
1944 put_task_struct(task);
1945 if (!mm)
1946 goto out;
1947
1948 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1949 if (rc)
1950 goto out_mmput;
1951
70335abb 1952 rc = -ENOENT;
640708a2
PE		 1953 down_read(&mm->mmap_sem);
1954 vma = find_exact_vma(mm, vm_start, vm_end);
1955 if (vma && vma->vm_file) {
1956 *path = vma->vm_file->f_path;
1957 path_get(path);
1958 rc = 0;
1959 }
1960 up_read(&mm->mmap_sem);
1961
1962out_mmput:
1963 mmput(mm);
1964out:
1965 return rc;
1966}
1967
1968struct map_files_info {
7b540d06 1969 fmode_t mode;
640708a2
PE		 1970 unsigned long len;
1971 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1972};
1973
bdb4d100
CO		 1974/*
1975 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1976 * symlinks may be used to bypass permissions on ancestor directories in the
1977 * path to the file in question.
1978 */
1979static const char *
6b255391 1980proc_map_files_get_link(struct dentry *dentry,
fceef393
AV		 1981 struct inode *inode,
1982 struct delayed_call *done)
bdb4d100
CO		 1983{
1984 if (!capable(CAP_SYS_ADMIN))
1985 return ERR_PTR(-EPERM);
1986
fceef393 1987 return proc_pid_get_link(dentry, inode, done);
bdb4d100
CO		 1988}
1989
1990/*
6b255391 1991 * Identical to proc_pid_link_inode_operations except for get_link()
bdb4d100
CO		 1992 */
1993static const struct inode_operations proc_map_files_link_inode_operations = {
1994 .readlink = proc_pid_readlink,
6b255391 1995 .get_link = proc_map_files_get_link,
bdb4d100
CO		 1996 .setattr = proc_setattr,
1997};
1998
c52a47ac 1999static int
640708a2
PE		 2000proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2001 struct task_struct *task, const void *ptr)
2002{
7b540d06 2003 fmode_t mode = (fmode_t)(unsigned long)ptr;
640708a2
PE		 2004 struct proc_inode *ei;
2005 struct inode *inode;
2006
640708a2
PE		 2007 inode = proc_pid_make_inode(dir->i_sb, task);
2008 if (!inode)
c52a47ac 2009 return -ENOENT;
640708a2
PE		 2010
2011 ei = PROC_I(inode);
6b255391 2012 ei->op.proc_get_link = map_files_get_link;
640708a2 2013
bdb4d100 2014 inode->i_op = &proc_map_files_link_inode_operations;
640708a2
PE		 2015 inode->i_size = 64;
2016 inode->i_mode = S_IFLNK;
2017
7b540d06 2018 if (mode & FMODE_READ)
640708a2 2019 inode->i_mode |= S_IRUSR;
7b540d06 2020 if (mode & FMODE_WRITE)
640708a2
PE		 2021 inode->i_mode |= S_IWUSR;
2022
2023 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2024 d_add(dentry, inode);
2025
c52a47ac 2026 return 0;
640708a2
PE		 2027}
2028
2029static struct dentry *proc_map_files_lookup(struct inode *dir,
00cd8dd3 2030 struct dentry *dentry, unsigned int flags)
640708a2
PE		 2031{
2032 unsigned long vm_start, vm_end;
2033 struct vm_area_struct *vma;
2034 struct task_struct *task;
c52a47ac 2035 int result;
640708a2
PE		 2036 struct mm_struct *mm;
2037
c52a47ac 2038 result = -ENOENT;
640708a2
PE		 2039 task = get_proc_task(dir);
2040 if (!task)
2041 goto out;
2042
c52a47ac 2043 result = -EACCES;
caaee623 2044 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
640708a2
PE		 2045 goto out_put_task;
2046
c52a47ac 2047 result = -ENOENT;
640708a2 2048 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
eb94cd96 2049 goto out_put_task;
640708a2
PE		 2050
2051 mm = get_task_mm(task);
2052 if (!mm)
eb94cd96 2053 goto out_put_task;
640708a2
PE		 2054
2055 down_read(&mm->mmap_sem);
2056 vma = find_exact_vma(mm, vm_start, vm_end);
2057 if (!vma)
2058 goto out_no_vma;
2059
05f56484
SK		 2060 if (vma->vm_file)
2061 result = proc_map_files_instantiate(dir, dentry, task,
2062 (void *)(unsigned long)vma->vm_file->f_mode);
640708a2
PE		 2063
2064out_no_vma:
2065 up_read(&mm->mmap_sem);
2066 mmput(mm);
640708a2
PE		 2067out_put_task:
2068 put_task_struct(task);
2069out:
c52a47ac 2070 return ERR_PTR(result);
640708a2
PE		 2071}
2072
2073static const struct inode_operations proc_map_files_inode_operations = {
2074 .lookup = proc_map_files_lookup,
2075 .permission = proc_fd_permission,
2076 .setattr = proc_setattr,
2077};
2078
2079static int
f0c3b509 2080proc_map_files_readdir(struct file *file, struct dir_context *ctx)
640708a2 2081{
640708a2
PE		 2082 struct vm_area_struct *vma;
2083 struct task_struct *task;
2084 struct mm_struct *mm;
f0c3b509
AV		 2085 unsigned long nr_files, pos, i;
2086 struct flex_array *fa = NULL;
2087 struct map_files_info info;
2088 struct map_files_info *p;
640708a2
PE		 2089 int ret;
2090
640708a2 2091 ret = -ENOENT;
f0c3b509 2092 task = get_proc_task(file_inode(file));
640708a2
PE		 2093 if (!task)
2094 goto out;
2095
2096 ret = -EACCES;
caaee623 2097 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
640708a2
PE		 2098 goto out_put_task;
2099
2100 ret = 0;
f0c3b509
AV		 2101 if (!dir_emit_dots(file, ctx))
2102 goto out_put_task;
640708a2 2103
f0c3b509
AV		 2104 mm = get_task_mm(task);
2105 if (!mm)
2106 goto out_put_task;
2107 down_read(&mm->mmap_sem);
640708a2 2108
f0c3b509 2109 nr_files = 0;
640708a2 2110
f0c3b509
AV		 2111 /*
2112 * We need two passes here:
2113 *
2114 * 1) Collect vmas of mapped files with mmap_sem taken
2115 * 2) Release mmap_sem and instantiate entries
2116 *
2117 * otherwise we get lockdep complained, since filldir()
2118 * routine might require mmap_sem taken in might_fault().
2119 */
640708a2 2120
f0c3b509
AV		 2121 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2122 if (vma->vm_file && ++pos > ctx->pos)
2123 nr_files++;
2124 }
2125
2126 if (nr_files) {
2127 fa = flex_array_alloc(sizeof(info), nr_files,
2128 GFP_KERNEL);
2129 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2130 GFP_KERNEL)) {
2131 ret = -ENOMEM;
2132 if (fa)
2133 flex_array_free(fa);
2134 up_read(&mm->mmap_sem);
2135 mmput(mm);
2136 goto out_put_task;
640708a2 2137 }
f0c3b509
AV		 2138 for (i = 0, vma = mm->mmap, pos = 2; vma;
2139 vma = vma->vm_next) {
2140 if (!vma->vm_file)
2141 continue;
2142 if (++pos <= ctx->pos)
2143 continue;
2144
2145 info.mode = vma->vm_file->f_mode;
2146 info.len = snprintf(info.name,
2147 sizeof(info.name), "%lx-%lx",
2148 vma->vm_start, vma->vm_end);
2149 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2150 BUG();
640708a2 2151 }
640708a2 2152 }
f0c3b509
AV		 2153 up_read(&mm->mmap_sem);
2154
2155 for (i = 0; i < nr_files; i++) {
2156 p = flex_array_get(fa, i);
2157 if (!proc_fill_cache(file, ctx,
2158 p->name, p->len,
2159 proc_map_files_instantiate,
2160 task,
2161 (void *)(unsigned long)p->mode))
2162 break;
2163 ctx->pos++;
640708a2 2164 }
f0c3b509
AV		 2165 if (fa)
2166 flex_array_free(fa);
2167 mmput(mm);
640708a2 2168
640708a2
PE		 2169out_put_task:
2170 put_task_struct(task);
2171out:
2172 return ret;
2173}
2174
2175static const struct file_operations proc_map_files_operations = {
2176 .read = generic_read_dir,
f50752ea
AV		 2177 .iterate_shared = proc_map_files_readdir,
2178 .llseek = generic_file_llseek,
640708a2
PE		 2179};
2180
b5946bea 2181#ifdef CONFIG_CHECKPOINT_RESTORE
48f6a7a5
PE		 2182struct timers_private {
2183 struct pid *pid;
2184 struct task_struct *task;
2185 struct sighand_struct *sighand;
57b8015e 2186 struct pid_namespace *ns;
48f6a7a5
PE		 2187 unsigned long flags;
2188};
2189
2190static void *timers_start(struct seq_file *m, loff_t *pos)
2191{
2192 struct timers_private *tp = m->private;
2193
2194 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2195 if (!tp->task)
2196 return ERR_PTR(-ESRCH);
2197
2198 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2199 if (!tp->sighand)
2200 return ERR_PTR(-ESRCH);
2201
2202 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2203}
2204
2205static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2206{
2207 struct timers_private *tp = m->private;
2208 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2209}
2210
2211static void timers_stop(struct seq_file *m, void *v)
2212{
2213 struct timers_private *tp = m->private;
2214
2215 if (tp->sighand) {
2216 unlock_task_sighand(tp->task, &tp->flags);
2217 tp->sighand = NULL;
2218 }
2219
2220 if (tp->task) {
2221 put_task_struct(tp->task);
2222 tp->task = NULL;
2223 }
2224}
2225
2226static int show_timer(struct seq_file *m, void *v)
2227{
2228 struct k_itimer *timer;
57b8015e
PE		 2229 struct timers_private *tp = m->private;
2230 int notify;
cedbccab 2231 static const char * const nstr[] = {
57b8015e
PE		 2232 [SIGEV_SIGNAL] = "signal",
2233 [SIGEV_NONE] = "none",
2234 [SIGEV_THREAD] = "thread",
2235 };
48f6a7a5
PE		 2236
2237 timer = list_entry((struct list_head *)v, struct k_itimer, list);
57b8015e
PE		 2238 notify = timer->it_sigev_notify;
2239
48f6a7a5 2240 seq_printf(m, "ID: %d\n", timer->it_id);
25ce3191
JP		 2241 seq_printf(m, "signal: %d/%p\n",
2242 timer->sigq->info.si_signo,
2243 timer->sigq->info.si_value.sival_ptr);
57b8015e 2244 seq_printf(m, "notify: %s/%s.%d\n",
25ce3191
JP		 2245 nstr[notify & ~SIGEV_THREAD_ID],
2246 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2247 pid_nr_ns(timer->it_pid, tp->ns));
15ef0298 2248 seq_printf(m, "ClockID: %d\n", timer->it_clock);
48f6a7a5
PE		 2249
2250 return 0;
2251}
2252
2253static const struct seq_operations proc_timers_seq_ops = {
2254 .start = timers_start,
2255 .next = timers_next,
2256 .stop = timers_stop,
2257 .show = show_timer,
2258};
2259
2260static int proc_timers_open(struct inode *inode, struct file *file)
2261{
2262 struct timers_private *tp;
2263
2264 tp = __seq_open_private(file, &proc_timers_seq_ops,
2265 sizeof(struct timers_private));
2266 if (!tp)
2267 return -ENOMEM;
2268
2269 tp->pid = proc_pid(inode);
57b8015e 2270 tp->ns = inode->i_sb->s_fs_info;
48f6a7a5
PE		 2271 return 0;
2272}
2273
2274static const struct file_operations proc_timers_operations = {
2275 .open = proc_timers_open,
2276 .read = seq_read,
2277 .llseek = seq_lseek,
2278 .release = seq_release_private,
2279};
b5946bea 2280#endif
640708a2 2281
5de23d43
JS		 2282static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2283 size_t count, loff_t *offset)
2284{
2285 struct inode *inode = file_inode(file);
2286 struct task_struct *p;
2287 u64 slack_ns;
2288 int err;
2289
2290 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2291 if (err < 0)
2292 return err;
2293
2294 p = get_proc_task(inode);
2295 if (!p)
2296 return -ESRCH;
2297
4b2bd5fe
JS		 2298 if (p != current) {
2299 if (!capable(CAP_SYS_NICE)) {
2300 count = -EPERM;
2301 goto out;
2302 }
5de23d43 2303
4b2bd5fe
JS		 2304 err = security_task_setscheduler(p);
2305 if (err) {
2306 count = err;
2307 goto out;
2308 }
904763e1
JS		 2309 }
2310
7abbaf94
JS		 2311 task_lock(p);
2312 if (slack_ns == 0)
2313 p->timer_slack_ns = p->default_timer_slack_ns;
2314 else
2315 p->timer_slack_ns = slack_ns;
2316 task_unlock(p);
2317
2318out:
5de23d43
JS		 2319 put_task_struct(p);
2320
2321 return count;
2322}
2323
2324static int timerslack_ns_show(struct seq_file *m, void *v)
2325{
2326 struct inode *inode = m->private;
2327 struct task_struct *p;
7abbaf94 2328 int err = 0;
5de23d43
JS		 2329
2330 p = get_proc_task(inode);
2331 if (!p)
2332 return -ESRCH;
2333
4b2bd5fe 2334 if (p != current) {
5de23d43 2335
4b2bd5fe
JS		 2336 if (!capable(CAP_SYS_NICE)) {
2337 err = -EPERM;
2338 goto out;
2339 }
2340 err = security_task_getscheduler(p);
2341 if (err)
2342 goto out;
2343 }
904763e1 2344
7abbaf94
JS		 2345 task_lock(p);
2346 seq_printf(m, "%llu\n", p->timer_slack_ns);
2347 task_unlock(p);
2348
2349out:
5de23d43
JS		 2350 put_task_struct(p);
2351
2352 return err;
2353}
2354
2355static int timerslack_ns_open(struct inode *inode, struct file *filp)
2356{
2357 return single_open(filp, timerslack_ns_show, inode);
2358}
2359
2360static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2361 .open = timerslack_ns_open,
2362 .read = seq_read,
2363 .write = timerslack_ns_write,
2364 .llseek = seq_lseek,
2365 .release = single_release,
2366};
2367
c52a47ac 2368static int proc_pident_instantiate(struct inode *dir,
c5141e6d 2369 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8 2370{
c5141e6d 2371 const struct pid_entry *p = ptr;
444ceed8
EB		 2372 struct inode *inode;
2373 struct proc_inode *ei;
444ceed8 2374
61a28784 2375 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 2376 if (!inode)
2377 goto out;
2378
2379 ei = PROC_I(inode);
2380 inode->i_mode = p->mode;
2381 if (S_ISDIR(inode->i_mode))
bfe86848 2382 set_nlink(inode, 2); /* Use getattr to fix if necessary */
444ceed8
EB		 2383 if (p->iop)
2384 inode->i_op = p->iop;
2385 if (p->fop)
2386 inode->i_fop = p->fop;
2387 ei->op = p->op;
fb045adb 2388 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 2389 d_add(dentry, inode);
2390 /* Close the race of the process dying before we return the dentry */
0b728e19 2391 if (pid_revalidate(dentry, 0))
c52a47ac 2392 return 0;
444ceed8 2393out:
c52a47ac 2394 return -ENOENT;
444ceed8
EB		 2395}
2396
1da177e4
LT		 2397static struct dentry *proc_pident_lookup(struct inode *dir,
2398 struct dentry *dentry,
c5141e6d 2399 const struct pid_entry *ents,
7bcd6b0e 2400 unsigned int nents)
1da177e4 2401{
c52a47ac 2402 int error;
99f89551 2403 struct task_struct *task = get_proc_task(dir);
c5141e6d 2404 const struct pid_entry *p, *last;
1da177e4 2405
c52a47ac 2406 error = -ENOENT;
1da177e4 2407
99f89551
EB		 2408 if (!task)
2409 goto out_no_task;
1da177e4 2410
20cdc894
EB		 2411 /*
2412 * Yes, it does not scale. And it should not. Don't add
2413 * new entries into /proc/<tgid>/ without very good reasons.
2414 */
7bcd6b0e
EB		 2415 last = &ents[nents - 1];
2416 for (p = ents; p <= last; p++) {
1da177e4
LT		 2417 if (p->len != dentry->d_name.len)
2418 continue;
2419 if (!memcmp(dentry->d_name.name, p->name, p->len))
2420 break;
2421 }
7bcd6b0e 2422 if (p > last)
1da177e4
LT		 2423 goto out;
2424
444ceed8 2425 error = proc_pident_instantiate(dir, dentry, task, p);
1da177e4 2426out:
99f89551
EB		 2427 put_task_struct(task);
2428out_no_task:
c52a47ac 2429 return ERR_PTR(error);
1da177e4
LT		 2430}
2431
f0c3b509 2432static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
c5141e6d 2433 const struct pid_entry *ents, unsigned int nents)
28a6d671 2434{
f0c3b509
AV		 2435 struct task_struct *task = get_proc_task(file_inode(file));
2436 const struct pid_entry *p;
28a6d671 2437
28a6d671 2438 if (!task)
f0c3b509 2439 return -ENOENT;
28a6d671 2440
f0c3b509
AV		 2441 if (!dir_emit_dots(file, ctx))
2442 goto out;
2443
2444 if (ctx->pos >= nents + 2)
2445 goto out;
28a6d671 2446
f0c3b509
AV		 2447 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2448 if (!proc_fill_cache(file, ctx, p->name, p->len,
2449 proc_pident_instantiate, task, p))
2450 break;
2451 ctx->pos++;
2452 }
28a6d671 2453out:
61a28784 2454 put_task_struct(task);
f0c3b509 2455 return 0;
1da177e4
LT		 2456}
2457
28a6d671
EB		 2458#ifdef CONFIG_SECURITY
2459static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2460 size_t count, loff_t *ppos)
2461{
496ad9aa 2462 struct inode * inode = file_inode(file);
04ff9708 2463 char *p = NULL;
28a6d671
EB		 2464 ssize_t length;
2465 struct task_struct *task = get_proc_task(inode);
2466
28a6d671 2467 if (!task)
04ff9708 2468 return -ESRCH;
28a6d671
EB		 2469
2470 length = security_getprocattr(task,
2fddfeef 2471 (char*)file->f_path.dentry->d_name.name,
04ff9708 2472 &p);
28a6d671 2473 put_task_struct(task);
04ff9708
AV		 2474 if (length > 0)
2475 length = simple_read_from_buffer(buf, count, ppos, p, length);
2476 kfree(p);
28a6d671 2477 return length;
1da177e4
LT		 2478}
2479
28a6d671
EB		 2480static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2481 size_t count, loff_t *ppos)
2482{
496ad9aa 2483 struct inode * inode = file_inode(file);
bb646cdb 2484 void *page;
28a6d671
EB		 2485 ssize_t length;
2486 struct task_struct *task = get_proc_task(inode);
2487
2488 length = -ESRCH;
2489 if (!task)
2490 goto out_no_task;
2491 if (count > PAGE_SIZE)
2492 count = PAGE_SIZE;
2493
2494 /* No partial writes. */
2495 length = -EINVAL;
2496 if (*ppos != 0)
2497 goto out;
2498
bb646cdb
AV		 2499 page = memdup_user(buf, count);
2500 if (IS_ERR(page)) {
2501 length = PTR_ERR(page);
28a6d671 2502 goto out;
bb646cdb 2503 }
28a6d671 2504
107db7c7 2505 /* Guard against adverse ptrace interaction */
9b1bf12d 2506 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
107db7c7
DH		 2507 if (length < 0)
2508 goto out_free;
2509
28a6d671 2510 length = security_setprocattr(task,
2fddfeef 2511 (char*)file->f_path.dentry->d_name.name,
bb646cdb 2512 page, count);
9b1bf12d 2513 mutex_unlock(&task->signal->cred_guard_mutex);
28a6d671 2514out_free:
bb646cdb 2515 kfree(page);
28a6d671
EB		 2516out:
2517 put_task_struct(task);
2518out_no_task:
2519 return length;
2520}
2521
00977a59 2522static const struct file_operations proc_pid_attr_operations = {
28a6d671
EB		 2523 .read = proc_pid_attr_read,
2524 .write = proc_pid_attr_write,
87df8424 2525 .llseek = generic_file_llseek,
28a6d671
EB		 2526};
2527
c5141e6d 2528static const struct pid_entry attr_dir_stuff[] = {
631f9c18
AD		 2529 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2530 REG("prev", S_IRUGO, proc_pid_attr_operations),
2531 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2532 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2533 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2534 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
28a6d671
EB		 2535};
2536
f0c3b509 2537static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
28a6d671 2538{
f0c3b509
AV		 2539 return proc_pident_readdir(file, ctx,
2540 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2541}
2542
00977a59 2543static const struct file_operations proc_attr_dir_operations = {
1da177e4 2544 .read = generic_read_dir,
f50752ea
AV		 2545 .iterate_shared = proc_attr_dir_readdir,
2546 .llseek = generic_file_llseek,
1da177e4
LT		 2547};
2548
72d9dcfc 2549static struct dentry *proc_attr_dir_lookup(struct inode *dir,
00cd8dd3 2550 struct dentry *dentry, unsigned int flags)
28a6d671 2551{
7bcd6b0e
EB		 2552 return proc_pident_lookup(dir, dentry,
2553 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2554}
2555
c5ef1c42 2556static const struct inode_operations proc_attr_dir_inode_operations = {
72d9dcfc 2557 .lookup = proc_attr_dir_lookup,
99f89551 2558 .getattr = pid_getattr,
6d76fa58 2559 .setattr = proc_setattr,
1da177e4
LT		 2560};
2561
28a6d671
EB		 2562#endif
2563
698ba7b5 2564#ifdef CONFIG_ELF_CORE
3cb4a0bb
KH		 2565static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2566 size_t count, loff_t *ppos)
2567{
496ad9aa 2568 struct task_struct *task = get_proc_task(file_inode(file));
3cb4a0bb
KH		 2569 struct mm_struct *mm;
2570 char buffer[PROC_NUMBUF];
2571 size_t len;
2572 int ret;
2573
2574 if (!task)
2575 return -ESRCH;
2576
2577 ret = 0;
2578 mm = get_task_mm(task);
2579 if (mm) {
2580 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2581 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2582 MMF_DUMP_FILTER_SHIFT));
2583 mmput(mm);
2584 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2585 }
2586
2587 put_task_struct(task);
2588
2589 return ret;
2590}
2591
2592static ssize_t proc_coredump_filter_write(struct file *file,
2593 const char __user *buf,
2594 size_t count,
2595 loff_t *ppos)
2596{
2597 struct task_struct *task;
2598 struct mm_struct *mm;
3cb4a0bb
KH		 2599 unsigned int val;
2600 int ret;
2601 int i;
2602 unsigned long mask;
2603
774636e1
AD		 2604 ret = kstrtouint_from_user(buf, count, 0, &val);
2605 if (ret < 0)
2606 return ret;
3cb4a0bb
KH		 2607
2608 ret = -ESRCH;
496ad9aa 2609 task = get_proc_task(file_inode(file));
3cb4a0bb
KH		 2610 if (!task)
2611 goto out_no_task;
2612
3cb4a0bb
KH		 2613 mm = get_task_mm(task);
2614 if (!mm)
2615 goto out_no_mm;
41a0c249 2616 ret = 0;
3cb4a0bb
KH		 2617
2618 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2619 if (val & mask)
2620 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2621 else
2622 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2623 }
2624
2625 mmput(mm);
2626 out_no_mm:
2627 put_task_struct(task);
2628 out_no_task:
774636e1
AD		 2629 if (ret < 0)
2630 return ret;
2631 return count;
3cb4a0bb
KH		 2632}
2633
2634static const struct file_operations proc_coredump_filter_operations = {
2635 .read = proc_coredump_filter_read,
2636 .write = proc_coredump_filter_write,
87df8424 2637 .llseek = generic_file_llseek,
3cb4a0bb
KH		 2638};
2639#endif
2640
aba76fdb 2641#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 2642static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
297c5d92 2643{
940389b8 2644 struct task_io_accounting acct = task->ioac;
5995477a 2645 unsigned long flags;
293eb1e7 2646 int result;
5995477a 2647
293eb1e7
VK		 2648 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2649 if (result)
2650 return result;
2651
caaee623 2652 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
293eb1e7
VK		 2653 result = -EACCES;
2654 goto out_unlock;
2655 }
1d1221f3 2656
5995477a
AR		 2657 if (whole && lock_task_sighand(task, &flags)) {
2658 struct task_struct *t = task;
2659
2660 task_io_accounting_add(&acct, &task->signal->ioac);
2661 while_each_thread(task, t)
2662 task_io_accounting_add(&acct, &t->ioac);
2663
2664 unlock_task_sighand(task, &flags);
297c5d92 2665 }
25ce3191
JP		 2666 seq_printf(m,
2667 "rchar: %llu\n"
2668 "wchar: %llu\n"
2669 "syscr: %llu\n"
2670 "syscw: %llu\n"
2671 "read_bytes: %llu\n"
2672 "write_bytes: %llu\n"
2673 "cancelled_write_bytes: %llu\n",
2674 (unsigned long long)acct.rchar,
2675 (unsigned long long)acct.wchar,
2676 (unsigned long long)acct.syscr,
2677 (unsigned long long)acct.syscw,
2678 (unsigned long long)acct.read_bytes,
2679 (unsigned long long)acct.write_bytes,
2680 (unsigned long long)acct.cancelled_write_bytes);
2681 result = 0;
2682
293eb1e7
VK		 2683out_unlock:
2684 mutex_unlock(&task->signal->cred_guard_mutex);
2685 return result;
297c5d92
AR		 2686}
2687
19aadc98
AD		 2688static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2689 struct pid *pid, struct task_struct *task)
297c5d92 2690{
19aadc98 2691 return do_io_accounting(task, m, 0);
aba76fdb 2692}
297c5d92 2693
19aadc98
AD		 2694static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2695 struct pid *pid, struct task_struct *task)
297c5d92 2696{
19aadc98 2697 return do_io_accounting(task, m, 1);
297c5d92
AR		 2698}
2699#endif /* CONFIG_TASK_IO_ACCOUNTING */
aba76fdb 2700
22d917d8
EB		 2701#ifdef CONFIG_USER_NS
2702static int proc_id_map_open(struct inode *inode, struct file *file,
ccf94f1b 2703 const struct seq_operations *seq_ops)
22d917d8
EB		 2704{
2705 struct user_namespace *ns = NULL;
2706 struct task_struct *task;
2707 struct seq_file *seq;
2708 int ret = -EINVAL;
2709
2710 task = get_proc_task(inode);
2711 if (task) {
2712 rcu_read_lock();
2713 ns = get_user_ns(task_cred_xxx(task, user_ns));
2714 rcu_read_unlock();
2715 put_task_struct(task);
2716 }
2717 if (!ns)
2718 goto err;
2719
2720 ret = seq_open(file, seq_ops);
2721 if (ret)
2722 goto err_put_ns;
2723
2724 seq = file->private_data;
2725 seq->private = ns;
2726
2727 return 0;
2728err_put_ns:
2729 put_user_ns(ns);
2730err:
2731 return ret;
2732}
2733
2734static int proc_id_map_release(struct inode *inode, struct file *file)
2735{
2736 struct seq_file *seq = file->private_data;
2737 struct user_namespace *ns = seq->private;
2738 put_user_ns(ns);
2739 return seq_release(inode, file);
2740}
2741
2742static int proc_uid_map_open(struct inode *inode, struct file *file)
2743{
2744 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2745}
2746
2747static int proc_gid_map_open(struct inode *inode, struct file *file)
2748{
2749 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2750}
2751
f76d207a
EB		 2752static int proc_projid_map_open(struct inode *inode, struct file *file)
2753{
2754 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2755}
2756
22d917d8
EB		 2757static const struct file_operations proc_uid_map_operations = {
2758 .open = proc_uid_map_open,
2759 .write = proc_uid_map_write,
2760 .read = seq_read,
2761 .llseek = seq_lseek,
2762 .release = proc_id_map_release,
2763};
2764
2765static const struct file_operations proc_gid_map_operations = {
2766 .open = proc_gid_map_open,
2767 .write = proc_gid_map_write,
2768 .read = seq_read,
2769 .llseek = seq_lseek,
2770 .release = proc_id_map_release,
2771};
f76d207a
EB		 2772
2773static const struct file_operations proc_projid_map_operations = {
2774 .open = proc_projid_map_open,
2775 .write = proc_projid_map_write,
2776 .read = seq_read,
2777 .llseek = seq_lseek,
2778 .release = proc_id_map_release,
2779};
9cc46516
EB		 2780
2781static int proc_setgroups_open(struct inode *inode, struct file *file)
2782{
2783 struct user_namespace *ns = NULL;
2784 struct task_struct *task;
2785 int ret;
2786
2787 ret = -ESRCH;
2788 task = get_proc_task(inode);
2789 if (task) {
2790 rcu_read_lock();
2791 ns = get_user_ns(task_cred_xxx(task, user_ns));
2792 rcu_read_unlock();
2793 put_task_struct(task);
2794 }
2795 if (!ns)
2796 goto err;
2797
2798 if (file->f_mode & FMODE_WRITE) {
2799 ret = -EACCES;
2800 if (!ns_capable(ns, CAP_SYS_ADMIN))
2801 goto err_put_ns;
2802 }
2803
2804 ret = single_open(file, &proc_setgroups_show, ns);
2805 if (ret)
2806 goto err_put_ns;
2807
2808 return 0;
2809err_put_ns:
2810 put_user_ns(ns);
2811err:
2812 return ret;
2813}
2814
2815static int proc_setgroups_release(struct inode *inode, struct file *file)
2816{
2817 struct seq_file *seq = file->private_data;
2818 struct user_namespace *ns = seq->private;
2819 int ret = single_release(inode, file);
2820 put_user_ns(ns);
2821 return ret;
2822}
2823
2824static const struct file_operations proc_setgroups_operations = {
2825 .open = proc_setgroups_open,
2826 .write = proc_setgroups_write,
2827 .read = seq_read,
2828 .llseek = seq_lseek,
2829 .release = proc_setgroups_release,
2830};
22d917d8
EB		 2831#endif /* CONFIG_USER_NS */
2832
47830723
KC		 2833static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2834 struct pid *pid, struct task_struct *task)
2835{
a9712bc1
AV		 2836 int err = lock_trace(task);
2837 if (!err) {
2838 seq_printf(m, "%08x\n", task->personality);
2839 unlock_trace(task);
2840 }
2841 return err;
47830723
KC		 2842}
2843
28a6d671
EB		 2844/*
2845 * Thread groups
2846 */
00977a59 2847static const struct file_operations proc_task_operations;
c5ef1c42 2848static const struct inode_operations proc_task_inode_operations;
20cdc894 2849
c5141e6d 2850static const struct pid_entry tgid_base_stuff[] = {
631f9c18
AD		 2851 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2852 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
640708a2 2853 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
631f9c18 2854 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 2855 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
b2211a36 2856#ifdef CONFIG_NET
631f9c18 2857 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
b2211a36 2858#endif
631f9c18 2859 REG("environ", S_IRUSR, proc_environ_operations),
c5317167 2860 REG("auxv", S_IRUSR, proc_auxv_operations),
631f9c18 2861 ONE("status", S_IRUGO, proc_pid_status),
35a35046 2862 ONE("personality", S_IRUSR, proc_pid_personality),
1c963eb1 2863 ONE("limits", S_IRUGO, proc_pid_limits),
43ae34cb 2864#ifdef CONFIG_SCHED_DEBUG
631f9c18 2865 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
5091faa4
MG		 2866#endif
2867#ifdef CONFIG_SCHED_AUTOGROUP
2868 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
ebcb6734 2869#endif
4614a696 2870 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 2871#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6 2872 ONE("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 2873#endif
c2c0bb44 2874 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
631f9c18
AD		 2875 ONE("stat", S_IRUGO, proc_tgid_stat),
2876 ONE("statm", S_IRUGO, proc_pid_statm),
b7643757 2877 REG("maps", S_IRUGO, proc_pid_maps_operations),
28a6d671 2878#ifdef CONFIG_NUMA
b7643757 2879 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
28a6d671 2880#endif
631f9c18
AD		 2881 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2882 LNK("cwd", proc_cwd_link),
2883 LNK("root", proc_root_link),
2884 LNK("exe", proc_exe_link),
2885 REG("mounts", S_IRUGO, proc_mounts_operations),
2886 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2887 REG("mountstats", S_IRUSR, proc_mountstats_operations),
1e883281 2888#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 2889 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
b7643757 2890 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
32ed74a4 2891 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 2892#endif
2893#ifdef CONFIG_SECURITY
631f9c18 2894 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 2895#endif
2896#ifdef CONFIG_KALLSYMS
edfcd606 2897 ONE("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 2898#endif
2ec220e2 2899#ifdef CONFIG_STACKTRACE
35a35046 2900 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671 2901#endif
5968cece 2902#ifdef CONFIG_SCHED_INFO
f6e826ca 2903 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 2904#endif
9745512c 2905#ifdef CONFIG_LATENCYTOP
631f9c18 2906 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 2907#endif
8793d854 2908#ifdef CONFIG_PROC_PID_CPUSET
52de4779 2909 ONE("cpuset", S_IRUGO, proc_cpuset_show),
a424316c
PM		 2910#endif
2911#ifdef CONFIG_CGROUPS
006f4ac4 2912 ONE("cgroup", S_IRUGO, proc_cgroup_show),
28a6d671 2913#endif
6ba51e37 2914 ONE("oom_score", S_IRUGO, proc_oom_score),
fa0cbbf1 2915 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
a63d83f4 2916 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 2917#ifdef CONFIG_AUDITSYSCALL
631f9c18
AD		 2918 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2919 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 2920#endif
f4f154fd 2921#ifdef CONFIG_FAULT_INJECTION
631f9c18 2922 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 2923#endif
698ba7b5 2924#ifdef CONFIG_ELF_CORE
631f9c18 2925 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3cb4a0bb 2926#endif
aba76fdb 2927#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 2928 ONE("io", S_IRUSR, proc_tgid_io_accounting),
aba76fdb 2929#endif
f133ecca 2930#ifdef CONFIG_HARDWALL
d962c144 2931 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
f133ecca 2932#endif
22d917d8
EB		 2933#ifdef CONFIG_USER_NS
2934 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2935 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
f76d207a 2936 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
9cc46516 2937 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
22d917d8 2938#endif
48f6a7a5
PE		 2939#ifdef CONFIG_CHECKPOINT_RESTORE
2940 REG("timers", S_IRUGO, proc_timers_operations),
2941#endif
5de23d43 2942 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
28a6d671 2943};
1da177e4 2944
f0c3b509 2945static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
1da177e4 2946{
f0c3b509
AV		 2947 return proc_pident_readdir(file, ctx,
2948 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 2949}
2950
00977a59 2951static const struct file_operations proc_tgid_base_operations = {
1da177e4 2952 .read = generic_read_dir,
f50752ea
AV		 2953 .iterate_shared = proc_tgid_base_readdir,
2954 .llseek = generic_file_llseek,
1da177e4
LT		 2955};
2956
00cd8dd3
AV		 2957static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2958{
7bcd6b0e
EB		 2959 return proc_pident_lookup(dir, dentry,
2960 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 2961}
2962
c5ef1c42 2963static const struct inode_operations proc_tgid_base_inode_operations = {
28a6d671 2964 .lookup = proc_tgid_base_lookup,
99f89551 2965 .getattr = pid_getattr,
6d76fa58 2966 .setattr = proc_setattr,
0499680a 2967 .permission = proc_pid_permission,
1da177e4 2968};
1da177e4 2969
60347f67 2970static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
1da177e4 2971{
48e6484d 2972 struct dentry *dentry, *leader, *dir;
8578cea7 2973 char buf[PROC_NUMBUF];
48e6484d
EB		 2974 struct qstr name;
2975
2976 name.name = buf;
60347f67 2977 name.len = snprintf(buf, sizeof(buf), "%d", pid);
4f522a24 2978 /* no ->d_hash() rejects on procfs */
60347f67 2979 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d 2980 if (dentry) {
bbd51924 2981 d_invalidate(dentry);
48e6484d
EB		 2982 dput(dentry);
2983 }
1da177e4 2984
c35a7f18
ON		 2985 if (pid == tgid)
2986 return;
2987
48e6484d 2988 name.name = buf;
60347f67
PE		 2989 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2990 leader = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d
EB		 2991 if (!leader)
2992 goto out;
1da177e4 2993
48e6484d
EB		 2994 name.name = "task";
2995 name.len = strlen(name.name);
2996 dir = d_hash_and_lookup(leader, &name);
2997 if (!dir)
2998 goto out_put_leader;
2999
3000 name.name = buf;
60347f67 3001 name.len = snprintf(buf, sizeof(buf), "%d", pid);
48e6484d
EB		 3002 dentry = d_hash_and_lookup(dir, &name);
3003 if (dentry) {
bbd51924 3004 d_invalidate(dentry);
48e6484d 3005 dput(dentry);
1da177e4 3006 }
48e6484d
EB		 3007
3008 dput(dir);
3009out_put_leader:
3010 dput(leader);
3011out:
3012 return;
1da177e4
LT		 3013}
3014
0895e91d
RD		 3015/**
3016 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3017 * @task: task that should be flushed.
3018 *
3019 * When flushing dentries from proc, one needs to flush them from global
60347f67 3020 * proc (proc_mnt) and from all the namespaces' procs this task was seen
0895e91d
RD		 3021 * in. This call is supposed to do all of this job.
3022 *
3023 * Looks in the dcache for
3024 * /proc/@pid
3025 * /proc/@tgid/task/@pid
3026 * if either directory is present flushes it and all of it'ts children
3027 * from the dcache.
3028 *
3029 * It is safe and reasonable to cache /proc entries for a task until
3030 * that task exits. After that they just clog up the dcache with
3031 * useless entries, possibly causing useful dcache entries to be
3032 * flushed instead. This routine is proved to flush those useless
3033 * dcache entries at process exit time.
3034 *
3035 * NOTE: This routine is just an optimization so it does not guarantee
3036 * that no dcache entries will exist at process exit time it
3037 * just makes it very unlikely that any will persist.
60347f67
PE		 3038 */
3039
3040void proc_flush_task(struct task_struct *task)
3041{
9fcc2d15 3042 int i;
9b4d1cbe 3043 struct pid *pid, *tgid;
130f77ec
PE		 3044 struct upid *upid;
3045
130f77ec 3046 pid = task_pid(task);
9b4d1cbe 3047 tgid = task_tgid(task);
130f77ec 3048
9fcc2d15 3049 for (i = 0; i <= pid->level; i++) {
130f77ec
PE		 3050 upid = &pid->numbers[i];
3051 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
9b4d1cbe 3052 tgid->numbers[i].nr);
130f77ec 3053 }
60347f67
PE		 3054}
3055
c52a47ac
AV		 3056static int proc_pid_instantiate(struct inode *dir,
3057 struct dentry * dentry,
3058 struct task_struct *task, const void *ptr)
444ceed8 3059{
444ceed8
EB		 3060 struct inode *inode;
3061
61a28784 3062 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 3063 if (!inode)
3064 goto out;
3065
3066 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3067 inode->i_op = &proc_tgid_base_inode_operations;
3068 inode->i_fop = &proc_tgid_base_operations;
3069 inode->i_flags|=S_IMMUTABLE;
aed54175 3070
bfe86848
MS		 3071 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3072 ARRAY_SIZE(tgid_base_stuff)));
444ceed8 3073
fb045adb 3074 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 3075
3076 d_add(dentry, inode);
3077 /* Close the race of the process dying before we return the dentry */
0b728e19 3078 if (pid_revalidate(dentry, 0))
c52a47ac 3079 return 0;
444ceed8 3080out:
c52a47ac 3081 return -ENOENT;
444ceed8
EB		 3082}
3083
00cd8dd3 3084struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
1da177e4 3085{
335eb531 3086 int result = -ENOENT;
1da177e4 3087 struct task_struct *task;
1da177e4 3088 unsigned tgid;
b488893a 3089 struct pid_namespace *ns;
1da177e4 3090
dbcdb504 3091 tgid = name_to_int(&dentry->d_name);
1da177e4
LT		 3092 if (tgid == ~0U)
3093 goto out;
3094
b488893a 3095 ns = dentry->d_sb->s_fs_info;
de758734 3096 rcu_read_lock();
b488893a 3097 task = find_task_by_pid_ns(tgid, ns);
1da177e4
LT		 3098 if (task)
3099 get_task_struct(task);
de758734 3100 rcu_read_unlock();
1da177e4
LT		 3101 if (!task)
3102 goto out;
3103
444ceed8 3104 result = proc_pid_instantiate(dir, dentry, task, NULL);
1da177e4 3105 put_task_struct(task);
1da177e4 3106out:
c52a47ac 3107 return ERR_PTR(result);
1da177e4
LT		 3108}
3109
1da177e4 3110/*
0804ef4b 3111 * Find the first task with tgid >= tgid
0bc58a91 3112 *
1da177e4 3113 */
19fd4bb2
EB		 3114struct tgid_iter {
3115 unsigned int tgid;
0804ef4b 3116 struct task_struct *task;
19fd4bb2
EB		 3117};
3118static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3119{
0804ef4b 3120 struct pid *pid;
1da177e4 3121
19fd4bb2
EB		 3122 if (iter.task)
3123 put_task_struct(iter.task);
454cc105 3124 rcu_read_lock();
0804ef4b 3125retry:
19fd4bb2
EB		 3126 iter.task = NULL;
3127 pid = find_ge_pid(iter.tgid, ns);
0804ef4b 3128 if (pid) {
19fd4bb2
EB		 3129 iter.tgid = pid_nr_ns(pid, ns);
3130 iter.task = pid_task(pid, PIDTYPE_PID);
0804ef4b
EB		 3131 /* What we to know is if the pid we have find is the
3132 * pid of a thread_group_leader. Testing for task
3133 * being a thread_group_leader is the obvious thing
3134 * todo but there is a window when it fails, due to
3135 * the pid transfer logic in de_thread.
3136 *
3137 * So we perform the straight forward test of seeing
3138 * if the pid we have found is the pid of a thread
3139 * group leader, and don't worry if the task we have
3140 * found doesn't happen to be a thread group leader.
3141 * As we don't care in the case of readdir.
3142 */
19fd4bb2
EB		 3143 if (!iter.task || !has_group_leader_pid(iter.task)) {
3144 iter.tgid += 1;
0804ef4b 3145 goto retry;
19fd4bb2
EB		 3146 }
3147 get_task_struct(iter.task);
0bc58a91 3148 }
454cc105 3149 rcu_read_unlock();
19fd4bb2 3150 return iter;
1da177e4
LT		 3151}
3152
0097875b 3153#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
0804ef4b 3154
1da177e4 3155/* for the /proc/ directory itself, after non-process stuff has been done */
f0c3b509 3156int proc_pid_readdir(struct file *file, struct dir_context *ctx)
1da177e4 3157{
19fd4bb2 3158 struct tgid_iter iter;
3aa3377f 3159 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
f0c3b509 3160 loff_t pos = ctx->pos;
1da177e4 3161
021ada7d 3162 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
f0c3b509 3163 return 0;
1da177e4 3164
0097875b 3165 if (pos == TGID_OFFSET - 2) {
2b0143b5 3166 struct inode *inode = d_inode(ns->proc_self);
db963164 3167 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
f0c3b509 3168 return 0;
0097875b
EB		 3169 ctx->pos = pos = pos + 1;
3170 }
3171 if (pos == TGID_OFFSET - 1) {
2b0143b5 3172 struct inode *inode = d_inode(ns->proc_thread_self);
0097875b
EB		 3173 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3174 return 0;
3175 ctx->pos = pos = pos + 1;
021ada7d 3176 }
0097875b 3177 iter.tgid = pos - TGID_OFFSET;
19fd4bb2 3178 iter.task = NULL;
19fd4bb2
EB		 3179 for (iter = next_tgid(ns, iter);
3180 iter.task;
3181 iter.tgid += 1, iter = next_tgid(ns, iter)) {
f0c3b509
AV		 3182 char name[PROC_NUMBUF];
3183 int len;
3184 if (!has_pid_permissions(ns, iter.task, 2))
3185 continue;
0499680a 3186
f0c3b509
AV		 3187 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3188 ctx->pos = iter.tgid + TGID_OFFSET;
3189 if (!proc_fill_cache(file, ctx, name, len,
3190 proc_pid_instantiate, iter.task, NULL)) {
19fd4bb2 3191 put_task_struct(iter.task);
f0c3b509 3192 return 0;
1da177e4 3193 }
0bc58a91 3194 }
f0c3b509 3195 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
0bc58a91
EB		 3196 return 0;
3197}
1da177e4 3198
1b3044e3
JD		 3199/*
3200 * proc_tid_comm_permission is a special permission function exclusively
3201 * used for the node /proc/<pid>/task/<tid>/comm.
3202 * It bypasses generic permission checks in the case where a task of the same
3203 * task group attempts to access the node.
3204 * The rationale behind this is that glibc and bionic access this node for
3205 * cross thread naming (pthread_set/getname_np(!self)). However, if
3206 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3207 * which locks out the cross thread naming implementation.
3208 * This function makes sure that the node is always accessible for members of
3209 * same thread group.
3210 */
3211static int proc_tid_comm_permission(struct inode *inode, int mask)
3212{
3213 bool is_same_tgroup;
3214 struct task_struct *task;
3215
3216 task = get_proc_task(inode);
3217 if (!task)
3218 return -ESRCH;
3219 is_same_tgroup = same_thread_group(current, task);
3220 put_task_struct(task);
3221
3222 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3223 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3224 * read or written by the members of the corresponding
3225 * thread group.
3226 */
3227 return 0;
3228 }
3229
3230 return generic_permission(inode, mask);
3231}
3232
3233static const struct inode_operations proc_tid_comm_inode_operations = {
3234 .permission = proc_tid_comm_permission,
3235};
3236
28a6d671
EB		 3237/*
3238 * Tasks
3239 */
c5141e6d 3240static const struct pid_entry tid_base_stuff[] = {
631f9c18 3241 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3835541d 3242 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 3243 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
6ba8ed79
EB		 3244#ifdef CONFIG_NET
3245 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3246#endif
631f9c18 3247 REG("environ", S_IRUSR, proc_environ_operations),
c5317167 3248 REG("auxv", S_IRUSR, proc_auxv_operations),
631f9c18 3249 ONE("status", S_IRUGO, proc_pid_status),
35a35046 3250 ONE("personality", S_IRUSR, proc_pid_personality),
1c963eb1 3251 ONE("limits", S_IRUGO, proc_pid_limits),
43ae34cb 3252#ifdef CONFIG_SCHED_DEBUG
631f9c18 3253 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
ebcb6734 3254#endif
1b3044e3
JD		 3255 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3256 &proc_tid_comm_inode_operations,
3257 &proc_pid_set_comm_operations, {}),
ebcb6734 3258#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6 3259 ONE("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 3260#endif
c2c0bb44 3261 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
631f9c18
AD		 3262 ONE("stat", S_IRUGO, proc_tid_stat),
3263 ONE("statm", S_IRUGO, proc_pid_statm),
b7643757 3264 REG("maps", S_IRUGO, proc_tid_maps_operations),
2e13ba54 3265#ifdef CONFIG_PROC_CHILDREN
81841161
CG		 3266 REG("children", S_IRUGO, proc_tid_children_operations),
3267#endif
28a6d671 3268#ifdef CONFIG_NUMA
b7643757 3269 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
28a6d671 3270#endif
631f9c18
AD		 3271 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3272 LNK("cwd", proc_cwd_link),
3273 LNK("root", proc_root_link),
3274 LNK("exe", proc_exe_link),
3275 REG("mounts", S_IRUGO, proc_mounts_operations),
3276 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
1e883281 3277#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 3278 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
b7643757 3279 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
32ed74a4 3280 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 3281#endif
3282#ifdef CONFIG_SECURITY
631f9c18 3283 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 3284#endif
3285#ifdef CONFIG_KALLSYMS
edfcd606 3286 ONE("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 3287#endif
2ec220e2 3288#ifdef CONFIG_STACKTRACE
35a35046 3289 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671 3290#endif
5968cece 3291#ifdef CONFIG_SCHED_INFO
f6e826ca 3292 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 3293#endif
9745512c 3294#ifdef CONFIG_LATENCYTOP
631f9c18 3295 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 3296#endif
8793d854 3297#ifdef CONFIG_PROC_PID_CPUSET
52de4779 3298 ONE("cpuset", S_IRUGO, proc_cpuset_show),
a424316c
PM		 3299#endif
3300#ifdef CONFIG_CGROUPS
006f4ac4 3301 ONE("cgroup", S_IRUGO, proc_cgroup_show),
28a6d671 3302#endif
6ba51e37 3303 ONE("oom_score", S_IRUGO, proc_oom_score),
fa0cbbf1 3304 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
a63d83f4 3305 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 3306#ifdef CONFIG_AUDITSYSCALL
631f9c18 3307 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
26ec3c64 3308 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 3309#endif
f4f154fd 3310#ifdef CONFIG_FAULT_INJECTION
631f9c18 3311 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 3312#endif
297c5d92 3313#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 3314 ONE("io", S_IRUSR, proc_tid_io_accounting),
297c5d92 3315#endif
f133ecca 3316#ifdef CONFIG_HARDWALL
d962c144 3317 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
f133ecca 3318#endif
22d917d8
EB		 3319#ifdef CONFIG_USER_NS
3320 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3321 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
f76d207a 3322 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
9cc46516 3323 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
22d917d8 3324#endif
28a6d671
EB		 3325};
3326
f0c3b509 3327static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
28a6d671 3328{
f0c3b509
AV		 3329 return proc_pident_readdir(file, ctx,
3330 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 3331}
3332
00cd8dd3
AV		 3333static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3334{
7bcd6b0e
EB		 3335 return proc_pident_lookup(dir, dentry,
3336 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 3337}
3338
00977a59 3339static const struct file_operations proc_tid_base_operations = {
28a6d671 3340 .read = generic_read_dir,
f50752ea
AV		 3341 .iterate_shared = proc_tid_base_readdir,
3342 .llseek = generic_file_llseek,
28a6d671
EB		 3343};
3344
c5ef1c42 3345static const struct inode_operations proc_tid_base_inode_operations = {
28a6d671
EB		 3346 .lookup = proc_tid_base_lookup,
3347 .getattr = pid_getattr,
3348 .setattr = proc_setattr,
3349};
3350
c52a47ac 3351static int proc_task_instantiate(struct inode *dir,
c5141e6d 3352 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8 3353{
444ceed8 3354 struct inode *inode;
61a28784 3355 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 3356
3357 if (!inode)
3358 goto out;
3359 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3360 inode->i_op = &proc_tid_base_inode_operations;
3361 inode->i_fop = &proc_tid_base_operations;
3362 inode->i_flags|=S_IMMUTABLE;
aed54175 3363
bfe86848
MS		 3364 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3365 ARRAY_SIZE(tid_base_stuff)));
444ceed8 3366
fb045adb 3367 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 3368
3369 d_add(dentry, inode);
3370 /* Close the race of the process dying before we return the dentry */
0b728e19 3371 if (pid_revalidate(dentry, 0))
c52a47ac 3372 return 0;
444ceed8 3373out:
c52a47ac 3374 return -ENOENT;
444ceed8
EB		 3375}
3376
00cd8dd3 3377static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
28a6d671 3378{
c52a47ac 3379 int result = -ENOENT;
28a6d671
EB		 3380 struct task_struct *task;
3381 struct task_struct *leader = get_proc_task(dir);
28a6d671 3382 unsigned tid;
b488893a 3383 struct pid_namespace *ns;
28a6d671
EB		 3384
3385 if (!leader)
3386 goto out_no_task;
3387
dbcdb504 3388 tid = name_to_int(&dentry->d_name);
28a6d671
EB		 3389 if (tid == ~0U)
3390 goto out;
3391
b488893a 3392 ns = dentry->d_sb->s_fs_info;
28a6d671 3393 rcu_read_lock();
b488893a 3394 task = find_task_by_pid_ns(tid, ns);
28a6d671
EB		 3395 if (task)
3396 get_task_struct(task);
3397 rcu_read_unlock();
3398 if (!task)
3399 goto out;
bac0abd6 3400 if (!same_thread_group(leader, task))
28a6d671
EB		 3401 goto out_drop_task;
3402
444ceed8 3403 result = proc_task_instantiate(dir, dentry, task, NULL);
28a6d671
EB		 3404out_drop_task:
3405 put_task_struct(task);
3406out:
3407 put_task_struct(leader);
3408out_no_task:
c52a47ac 3409 return ERR_PTR(result);
28a6d671
EB		 3410}
3411
0bc58a91
EB		 3412/*
3413 * Find the first tid of a thread group to return to user space.
3414 *
3415 * Usually this is just the thread group leader, but if the users
3416 * buffer was too small or there was a seek into the middle of the
3417 * directory we have more work todo.
3418 *
3419 * In the case of a short read we start with find_task_by_pid.
3420 *
3421 * In the case of a seek we start with the leader and walk nr
3422 * threads past it.
3423 */
9f6e963f
ON		 3424static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3425 struct pid_namespace *ns)
0bc58a91 3426{
d855a4b7 3427 struct task_struct *pos, *task;
9f6e963f
ON		 3428 unsigned long nr = f_pos;
3429
3430 if (nr != f_pos) /* 32bit overflow? */
3431 return NULL;
1da177e4 3432
cc288738 3433 rcu_read_lock();
d855a4b7
ON		 3434 task = pid_task(pid, PIDTYPE_PID);
3435 if (!task)
3436 goto fail;
3437
3438 /* Attempt to start with the tid of a thread */
9f6e963f 3439 if (tid && nr) {
b488893a 3440 pos = find_task_by_pid_ns(tid, ns);
d855a4b7 3441 if (pos && same_thread_group(pos, task))
a872ff0c 3442 goto found;
0bc58a91 3443 }
1da177e4 3444
0bc58a91 3445 /* If nr exceeds the number of threads there is nothing todo */
9f6e963f 3446 if (nr >= get_nr_threads(task))
c986c14a 3447 goto fail;
1da177e4 3448
a872ff0c
ON		 3449 /* If we haven't found our starting place yet start
3450 * with the leader and walk nr threads forward.
0bc58a91 3451 */
d855a4b7 3452 pos = task = task->group_leader;
c986c14a 3453 do {
9f6e963f 3454 if (!nr--)
c986c14a 3455 goto found;
d855a4b7 3456 } while_each_thread(task, pos);
c986c14a
ON		 3457fail:
3458 pos = NULL;
3459 goto out;
a872ff0c
ON		 3460found:
3461 get_task_struct(pos);
3462out:
cc288738 3463 rcu_read_unlock();
0bc58a91
EB		 3464 return pos;
3465}
3466
3467/*
3468 * Find the next thread in the thread list.
3469 * Return NULL if there is an error or no next thread.
3470 *
3471 * The reference to the input task_struct is released.
3472 */
3473static struct task_struct *next_tid(struct task_struct *start)
3474{
c1df7fb8 3475 struct task_struct *pos = NULL;
cc288738 3476 rcu_read_lock();
c1df7fb8 3477 if (pid_alive(start)) {
0bc58a91 3478 pos = next_thread(start);
c1df7fb8
ON		 3479 if (thread_group_leader(pos))
3480 pos = NULL;
3481 else
3482 get_task_struct(pos);
3483 }
cc288738 3484 rcu_read_unlock();
0bc58a91
EB		 3485 put_task_struct(start);
3486 return pos;
1da177e4
LT		 3487}
3488
3489/* for the /proc/TGID/task/ directories */
f0c3b509 3490static int proc_task_readdir(struct file *file, struct dir_context *ctx)
1da177e4 3491{
d855a4b7
ON		 3492 struct inode *inode = file_inode(file);
3493 struct task_struct *task;
b488893a 3494 struct pid_namespace *ns;
f0c3b509 3495 int tid;
1da177e4 3496
d855a4b7 3497 if (proc_inode_is_dead(inode))
f0c3b509 3498 return -ENOENT;
1da177e4 3499
f0c3b509 3500 if (!dir_emit_dots(file, ctx))
d855a4b7 3501 return 0;
1da177e4 3502
0bc58a91
EB		 3503 /* f_version caches the tgid value that the last readdir call couldn't
3504 * return. lseek aka telldir automagically resets f_version to 0.
3505 */
3aa3377f 3506 ns = inode->i_sb->s_fs_info;
f0c3b509
AV		 3507 tid = (int)file->f_version;
3508 file->f_version = 0;
d855a4b7 3509 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
0bc58a91 3510 task;
f0c3b509
AV		 3511 task = next_tid(task), ctx->pos++) {
3512 char name[PROC_NUMBUF];
3513 int len;
b488893a 3514 tid = task_pid_nr_ns(task, ns);
f0c3b509
AV		 3515 len = snprintf(name, sizeof(name), "%d", tid);
3516 if (!proc_fill_cache(file, ctx, name, len,
3517 proc_task_instantiate, task, NULL)) {
0bc58a91
EB		 3518 /* returning this tgid failed, save it as the first
3519 * pid for the next readir call */
f0c3b509 3520 file->f_version = (u64)tid;
0bc58a91 3521 put_task_struct(task);
1da177e4 3522 break;
0bc58a91 3523 }
1da177e4 3524 }
d855a4b7 3525
f0c3b509 3526 return 0;
1da177e4 3527}
6e66b52b
EB		 3528
3529static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3530{
2b0143b5 3531 struct inode *inode = d_inode(dentry);
99f89551 3532 struct task_struct *p = get_proc_task(inode);
6e66b52b
EB		 3533 generic_fillattr(inode, stat);
3534
99f89551 3535 if (p) {
99f89551 3536 stat->nlink += get_nr_threads(p);
99f89551 3537 put_task_struct(p);
6e66b52b
EB		 3538 }
3539
3540 return 0;
3541}
28a6d671 3542
c5ef1c42 3543static const struct inode_operations proc_task_inode_operations = {
28a6d671
EB		 3544 .lookup = proc_task_lookup,
3545 .getattr = proc_task_getattr,
3546 .setattr = proc_setattr,
0499680a 3547 .permission = proc_pid_permission,
28a6d671
EB		 3548};
3549
00977a59 3550static const struct file_operations proc_task_operations = {
28a6d671 3551 .read = generic_read_dir,
f50752ea
AV		 3552 .iterate_shared = proc_task_readdir,
3553 .llseek = generic_file_llseek,
28a6d671 3554};
Linux 6.x block layer and io_uring tree(s)