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[linux-2.6-block.git] / fs / proc / base.c
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b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT		 2/*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
e070ad49
ML		 15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
1da177e4
LT		 49 */
50
7c0f6ba6 51#include <linux/uaccess.h>
1da177e4 52
1da177e4
LT		 53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
5995477a 57#include <linux/task_io_accounting_ops.h>
1da177e4 58#include <linux/init.h>
16f7e0fe 59#include <linux/capability.h>
1da177e4 60#include <linux/file.h>
9f3acc31 61#include <linux/fdtable.h>
1da177e4
LT		 62#include <linux/string.h>
63#include <linux/seq_file.h>
64#include <linux/namei.h>
6b3286ed 65#include <linux/mnt_namespace.h>
1da177e4 66#include <linux/mm.h>
a63d83f4 67#include <linux/swap.h>
b835996f 68#include <linux/rcupdate.h>
1da177e4 69#include <linux/kallsyms.h>
2ec220e2 70#include <linux/stacktrace.h>
d85f50d5 71#include <linux/resource.h>
5096add8 72#include <linux/module.h>
1da177e4
LT		 73#include <linux/mount.h>
74#include <linux/security.h>
75#include <linux/ptrace.h>
0d094efe 76#include <linux/tracehook.h>
87ebdc00 77#include <linux/printk.h>
efb1a57d 78#include <linux/cache.h>
a424316c 79#include <linux/cgroup.h>
1da177e4
LT		 80#include <linux/cpuset.h>
81#include <linux/audit.h>
5addc5dd 82#include <linux/poll.h>
1651e14e 83#include <linux/nsproxy.h>
8ac773b4 84#include <linux/oom.h>
3cb4a0bb 85#include <linux/elf.h>
60347f67 86#include <linux/pid_namespace.h>
22d917d8 87#include <linux/user_namespace.h>
5ad4e53b 88#include <linux/fs_struct.h>
5a0e3ad6 89#include <linux/slab.h>
4eb5aaa3 90#include <linux/sched/autogroup.h>
6e84f315 91#include <linux/sched/mm.h>
f7ccbae4 92#include <linux/sched/coredump.h>
b17b0153 93#include <linux/sched/debug.h>
3905f9ad 94#include <linux/sched/stat.h>
640708a2 95#include <linux/flex_array.h>
48f6a7a5 96#include <linux/posix-timers.h>
43d2b113 97#include <trace/events/oom.h>
1da177e4 98#include "internal.h"
faf60af1 99#include "fd.h"
1da177e4 100
ac7f1061
AD		 101#include "../../lib/kstrtox.h"
102
0f2fe20f
EB		 103/* NOTE:
104 * Implementing inode permission operations in /proc is almost
105 * certainly an error. Permission checks need to happen during
106 * each system call not at open time. The reason is that most of
107 * what we wish to check for permissions in /proc varies at runtime.
108 *
109 * The classic example of a problem is opening file descriptors
110 * in /proc for a task before it execs a suid executable.
111 */
112
efb1a57d
AD		 113static u8 nlink_tid __ro_after_init;
114static u8 nlink_tgid __ro_after_init;
1270dd8d 115
1da177e4 116struct pid_entry {
cedbccab 117 const char *name;
623f594e 118 unsigned int len;
d161a13f 119 umode_t mode;
c5ef1c42 120 const struct inode_operations *iop;
00977a59 121 const struct file_operations *fop;
20cdc894 122 union proc_op op;
1da177e4
LT		 123};
124
61a28784 125#define NOD(NAME, MODE, IOP, FOP, OP) { \
20cdc894 126 .name = (NAME), \
c5141e6d 127 .len = sizeof(NAME) - 1, \
20cdc894
EB		 128 .mode = MODE, \
129 .iop = IOP, \
130 .fop = FOP, \
131 .op = OP, \
132}
133
631f9c18
AD		 134#define DIR(NAME, MODE, iops, fops) \
135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
136#define LNK(NAME, get_link) \
61a28784 137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
20cdc894 138 &proc_pid_link_inode_operations, NULL, \
631f9c18
AD		 139 { .proc_get_link = get_link } )
140#define REG(NAME, MODE, fops) \
141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
631f9c18 142#define ONE(NAME, MODE, show) \
be614086
EB		 143 NOD(NAME, (S_IFREG|(MODE)), \
144 NULL, &proc_single_file_operations, \
631f9c18 145 { .proc_show = show } )
1da177e4 146
aed54175
VN		 147/*
148 * Count the number of hardlinks for the pid_entry table, excluding the .
149 * and .. links.
150 */
1270dd8d 151static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
aed54175
VN		 152 unsigned int n)
153{
154 unsigned int i;
155 unsigned int count;
156
1270dd8d 157 count = 2;
aed54175
VN		 158 for (i = 0; i < n; ++i) {
159 if (S_ISDIR(entries[i].mode))
160 ++count;
161 }
162
163 return count;
164}
165
f7ad3c6b 166static int get_task_root(struct task_struct *task, struct path *root)
1da177e4 167{
7c2c7d99
HD		 168 int result = -ENOENT;
169
0494f6ec 170 task_lock(task);
f7ad3c6b
MS		 171 if (task->fs) {
172 get_fs_root(task->fs, root);
7c2c7d99
HD		 173 result = 0;
174 }
0494f6ec 175 task_unlock(task);
7c2c7d99 176 return result;
0494f6ec
MS		 177}
178
7773fbc5 179static int proc_cwd_link(struct dentry *dentry, struct path *path)
0494f6ec 180{
2b0143b5 181 struct task_struct *task = get_proc_task(d_inode(dentry));
0494f6ec 182 int result = -ENOENT;
99f89551
EB		 183
184 if (task) {
f7ad3c6b
MS		 185 task_lock(task);
186 if (task->fs) {
187 get_fs_pwd(task->fs, path);
188 result = 0;
189 }
190 task_unlock(task);
99f89551
EB		 191 put_task_struct(task);
192 }
1da177e4
LT		 193 return result;
194}
195
7773fbc5 196static int proc_root_link(struct dentry *dentry, struct path *path)
1da177e4 197{
2b0143b5 198 struct task_struct *task = get_proc_task(d_inode(dentry));
1da177e4 199 int result = -ENOENT;
99f89551
EB		 200
201 if (task) {
f7ad3c6b 202 result = get_task_root(task, path);
99f89551
EB		 203 put_task_struct(task);
204 }
1da177e4
LT		 205 return result;
206}
207
e4b4e441 208static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
5ab82718 209 size_t count, loff_t *ppos)
1da177e4 210{
c2c0bb44 211 unsigned long arg_start, arg_end, env_start, env_end;
5ab82718
LT		 212 unsigned long pos, len;
213 char *page;
c2c0bb44 214
c2c0bb44 215 /* Check if process spawned far enough to have cmdline. */
e4b4e441
LT		 216 if (!mm->env_end)
217 return 0;
c2c0bb44 218
88aa7cc6 219 spin_lock(&mm->arg_lock);
c2c0bb44
AD		 220 arg_start = mm->arg_start;
221 arg_end = mm->arg_end;
222 env_start = mm->env_start;
223 env_end = mm->env_end;
88aa7cc6 224 spin_unlock(&mm->arg_lock);
c2c0bb44 225
5ab82718
LT		 226 if (arg_start >= arg_end)
227 return 0;
6a6cbe75 228
2ca66ff7 229 /*
5ab82718
LT		 230 * We have traditionally allowed the user to re-write
231 * the argument strings and overflow the end result
232 * into the environment section. But only do that if
233 * the environment area is contiguous to the arguments.
2ca66ff7 234 */
5ab82718
LT		 235 if (env_start != arg_end || env_start >= env_end)
236 env_start = env_end = arg_end;
237
f5b65348
LT		 238 /* .. and limit it to a maximum of one page of slop */
239 if (env_end >= arg_end + PAGE_SIZE)
240 env_end = arg_end + PAGE_SIZE - 1;
241
5ab82718
LT		 242 /* We're not going to care if "*ppos" has high bits set */
243 pos = arg_start + *ppos;
3cb4e162 244
5ab82718
LT		 245 /* .. but we do check the result is in the proper range */
246 if (pos < arg_start || pos >= env_end)
247 return 0;
a0a07b87 248
5ab82718
LT		 249 /* .. and we never go past env_end */
250 if (env_end - pos < count)
251 count = env_end - pos;
252
253 page = (char *)__get_free_page(GFP_KERNEL);
254 if (!page)
255 return -ENOMEM;
256
257 len = 0;
258 while (count) {
259 int got;
260 size_t size = min_t(size_t, PAGE_SIZE, count);
f5b65348
LT		 261 long offset;
262
263 /*
264 * Are we already starting past the official end?
265 * We always include the last byte that is *supposed*
266 * to be NUL
267 */
268 offset = (pos >= arg_end) ? pos - arg_end + 1 : 0;
5ab82718 269
f5b65348
LT		 270 got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON);
271 if (got <= offset)
5ab82718 272 break;
f5b65348 273 got -= offset;
5ab82718
LT		 274
275 /* Don't walk past a NUL character once you hit arg_end */
276 if (pos + got >= arg_end) {
277 int n = 0;
278
279 /*
280 * If we started before 'arg_end' but ended up
281 * at or after it, we start the NUL character
282 * check at arg_end-1 (where we expect the normal
283 * EOF to be).
284 *
285 * NOTE! This is smaller than 'got', because
286 * pos + got >= arg_end
287 */
288 if (pos < arg_end)
289 n = arg_end - pos - 1;
290
291 /* Cut off at first NUL after 'n' */
f5b65348
LT		 292 got = n + strnlen(page+n, offset+got-n);
293 if (got < offset)
5ab82718 294 break;
f5b65348
LT		 295 got -= offset;
296
297 /* Include the NUL if it existed */
298 if (got < size)
299 got++;
c2c0bb44 300 }
5ab82718 301
f5b65348 302 got -= copy_to_user(buf, page+offset, got);
5ab82718
LT		 303 if (unlikely(!got)) {
304 if (!len)
305 len = -EFAULT;
306 break;
c2c0bb44 307 }
5ab82718
LT		 308 pos += got;
309 buf += got;
310 len += got;
311 count -= got;
c2c0bb44
AD		 312 }
313
c2c0bb44 314 free_page((unsigned long)page);
5ab82718 315 return len;
1da177e4
LT		 316}
317
e4b4e441
LT		 318static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
319 size_t count, loff_t *pos)
320{
321 struct mm_struct *mm;
322 ssize_t ret;
323
324 mm = get_task_mm(tsk);
325 if (!mm)
326 return 0;
327
328 ret = get_mm_cmdline(mm, buf, count, pos);
c2c0bb44 329 mmput(mm);
e4b4e441
LT		 330 return ret;
331}
332
333static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
334 size_t count, loff_t *pos)
335{
336 struct task_struct *tsk;
337 ssize_t ret;
338
339 BUG_ON(*pos < 0);
340
341 tsk = get_proc_task(file_inode(file));
342 if (!tsk)
343 return -ESRCH;
344 ret = get_task_cmdline(tsk, buf, count, pos);
345 put_task_struct(tsk);
346 if (ret > 0)
347 *pos += ret;
348 return ret;
1da177e4
LT		 349}
350
c2c0bb44
AD		 351static const struct file_operations proc_pid_cmdline_ops = {
352 .read = proc_pid_cmdline_read,
353 .llseek = generic_file_llseek,
354};
355
1da177e4
LT		 356#ifdef CONFIG_KALLSYMS
357/*
358 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
359 * Returns the resolved symbol. If that fails, simply return the address.
360 */
edfcd606
AD		 361static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
362 struct pid *pid, struct task_struct *task)
1da177e4 363{
ffb45122 364 unsigned long wchan;
9281acea 365 char symname[KSYM_NAME_LEN];
1da177e4 366
24b2ec21
AD		 367 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
368 goto print0;
1da177e4 369
24b2ec21
AD		 370 wchan = get_wchan(task);
371 if (wchan && !lookup_symbol_name(wchan, symname)) {
21dae0ad 372 seq_puts(m, symname);
24b2ec21
AD		 373 return 0;
374 }
25ce3191 375
24b2ec21
AD		 376print0:
377 seq_putc(m, '0');
25ce3191 378 return 0;
1da177e4
LT		 379}
380#endif /* CONFIG_KALLSYMS */
381
a9712bc1
AV		 382static int lock_trace(struct task_struct *task)
383{
384 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
385 if (err)
386 return err;
caaee623 387 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
a9712bc1
AV		 388 mutex_unlock(&task->signal->cred_guard_mutex);
389 return -EPERM;
390 }
391 return 0;
392}
393
394static void unlock_trace(struct task_struct *task)
395{
396 mutex_unlock(&task->signal->cred_guard_mutex);
397}
398
2ec220e2
KC		 399#ifdef CONFIG_STACKTRACE
400
401#define MAX_STACK_TRACE_DEPTH 64
402
403static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
404 struct pid *pid, struct task_struct *task)
405{
406 struct stack_trace trace;
407 unsigned long *entries;
a9712bc1 408 int err;
2ec220e2 409
f8a00cef
JH		 410 /*
411 * The ability to racily run the kernel stack unwinder on a running task
412 * and then observe the unwinder output is scary; while it is useful for
413 * debugging kernel issues, it can also allow an attacker to leak kernel
414 * stack contents.
415 * Doing this in a manner that is at least safe from races would require
416 * some work to ensure that the remote task can not be scheduled; and
417 * even then, this would still expose the unwinder as local attack
418 * surface.
419 * Therefore, this interface is restricted to root.
420 */
421 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
422 return -EACCES;
423
6da2ec56
KC		 424 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
425 GFP_KERNEL);
2ec220e2
KC		 426 if (!entries)
427 return -ENOMEM;
428
429 trace.nr_entries = 0;
430 trace.max_entries = MAX_STACK_TRACE_DEPTH;
431 trace.entries = entries;
432 trace.skip = 0;
2ec220e2 433
a9712bc1
AV		 434 err = lock_trace(task);
435 if (!err) {
5d008fb4
AD		 436 unsigned int i;
437
a9712bc1
AV		 438 save_stack_trace_tsk(task, &trace);
439
440 for (i = 0; i < trace.nr_entries; i++) {
8f5abe84 441 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
a9712bc1
AV		 442 }
443 unlock_trace(task);
2ec220e2
KC		 444 }
445 kfree(entries);
446
a9712bc1 447 return err;
2ec220e2
KC		 448}
449#endif
450
5968cece 451#ifdef CONFIG_SCHED_INFO
1da177e4
LT		 452/*
453 * Provides /proc/PID/schedstat
454 */
f6e826ca
AD		 455static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
456 struct pid *pid, struct task_struct *task)
1da177e4 457{
5968cece
NR		 458 if (unlikely(!sched_info_on()))
459 seq_printf(m, "0 0 0\n");
460 else
461 seq_printf(m, "%llu %llu %lu\n",
25ce3191
JP		 462 (unsigned long long)task->se.sum_exec_runtime,
463 (unsigned long long)task->sched_info.run_delay,
464 task->sched_info.pcount);
465
466 return 0;
1da177e4
LT		 467}
468#endif
469
9745512c
AV		 470#ifdef CONFIG_LATENCYTOP
471static int lstats_show_proc(struct seq_file *m, void *v)
472{
473 int i;
13d77c37
HS		 474 struct inode *inode = m->private;
475 struct task_struct *task = get_proc_task(inode);
9745512c 476
13d77c37
HS		 477 if (!task)
478 return -ESRCH;
479 seq_puts(m, "Latency Top version : v0.1\n");
f6d2f584 480 for (i = 0; i < LT_SAVECOUNT; i++) {
34e49d4f
JP		 481 struct latency_record *lr = &task->latency_record[i];
482 if (lr->backtrace[0]) {
9745512c 483 int q;
34e49d4f
JP		 484 seq_printf(m, "%i %li %li",
485 lr->count, lr->time, lr->max);
9745512c 486 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
34e49d4f
JP		 487 unsigned long bt = lr->backtrace[q];
488 if (!bt)
9745512c 489 break;
34e49d4f 490 if (bt == ULONG_MAX)
9745512c 491 break;
34e49d4f 492 seq_printf(m, " %ps", (void *)bt);
9745512c 493 }
9d6de12f 494 seq_putc(m, '\n');
9745512c
AV		 495 }
496
497 }
13d77c37 498 put_task_struct(task);
9745512c
AV		 499 return 0;
500}
501
502static int lstats_open(struct inode *inode, struct file *file)
503{
13d77c37 504 return single_open(file, lstats_show_proc, inode);
d6643d12
HS		 505}
506
9745512c
AV		 507static ssize_t lstats_write(struct file *file, const char __user *buf,
508 size_t count, loff_t *offs)
509{
496ad9aa 510 struct task_struct *task = get_proc_task(file_inode(file));
9745512c 511
13d77c37
HS		 512 if (!task)
513 return -ESRCH;
9745512c 514 clear_all_latency_tracing(task);
13d77c37 515 put_task_struct(task);
9745512c
AV		 516
517 return count;
518}
519
520static const struct file_operations proc_lstats_operations = {
521 .open = lstats_open,
522 .read = seq_read,
523 .write = lstats_write,
524 .llseek = seq_lseek,
13d77c37 525 .release = single_release,
9745512c
AV		 526};
527
528#endif
529
6ba51e37
AD		 530static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
531 struct pid *pid, struct task_struct *task)
1da177e4 532{
ca79b0c2 533 unsigned long totalpages = totalram_pages() + total_swap_pages;
b95c35e7 534 unsigned long points = 0;
1da177e4 535
ef419398
ON		 536 points = oom_badness(task, NULL, NULL, totalpages) *
537 1000 / totalpages;
25ce3191
JP		 538 seq_printf(m, "%lu\n", points);
539
540 return 0;
1da177e4
LT		 541}
542
d85f50d5 543struct limit_names {
cedbccab
AD		 544 const char *name;
545 const char *unit;
d85f50d5
NH		 546};
547
548static const struct limit_names lnames[RLIM_NLIMITS] = {
cff4edb5 549 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
d85f50d5
NH		 550 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
551 [RLIMIT_DATA] = {"Max data size", "bytes"},
552 [RLIMIT_STACK] = {"Max stack size", "bytes"},
553 [RLIMIT_CORE] = {"Max core file size", "bytes"},
554 [RLIMIT_RSS] = {"Max resident set", "bytes"},
555 [RLIMIT_NPROC] = {"Max processes", "processes"},
556 [RLIMIT_NOFILE] = {"Max open files", "files"},
557 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
558 [RLIMIT_AS] = {"Max address space", "bytes"},
559 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
560 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
561 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
562 [RLIMIT_NICE] = {"Max nice priority", NULL},
563 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
8808117c 564 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
d85f50d5
NH		 565};
566
567/* Display limits for a process */
1c963eb1
AD		 568static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
569 struct pid *pid, struct task_struct *task)
d85f50d5
NH		 570{
571 unsigned int i;
d85f50d5 572 unsigned long flags;
d85f50d5
NH		 573
574 struct rlimit rlim[RLIM_NLIMITS];
575
a6bebbc8 576 if (!lock_task_sighand(task, &flags))
d85f50d5 577 return 0;
d85f50d5
NH		 578 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
579 unlock_task_sighand(task, &flags);
d85f50d5
NH		 580
581 /*
582 * print the file header
583 */
afe922c2
AD		 584 seq_puts(m, "Limit "
585 "Soft Limit "
586 "Hard Limit "
587 "Units \n");
d85f50d5
NH		 588
589 for (i = 0; i < RLIM_NLIMITS; i++) {
590 if (rlim[i].rlim_cur == RLIM_INFINITY)
1c963eb1 591 seq_printf(m, "%-25s %-20s ",
25ce3191 592 lnames[i].name, "unlimited");
d85f50d5 593 else
1c963eb1 594 seq_printf(m, "%-25s %-20lu ",
25ce3191 595 lnames[i].name, rlim[i].rlim_cur);
d85f50d5
NH		 596
597 if (rlim[i].rlim_max == RLIM_INFINITY)
1c963eb1 598 seq_printf(m, "%-20s ", "unlimited");
d85f50d5 599 else
1c963eb1 600 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
d85f50d5
NH		 601
602 if (lnames[i].unit)
1c963eb1 603 seq_printf(m, "%-10s\n", lnames[i].unit);
d85f50d5 604 else
1c963eb1 605 seq_putc(m, '\n');
d85f50d5
NH		 606 }
607
1c963eb1 608 return 0;
d85f50d5
NH		 609}
610
ebcb6734 611#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6
AD		 612static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
613 struct pid *pid, struct task_struct *task)
ebcb6734
RM		 614{
615 long nr;
616 unsigned long args[6], sp, pc;
25ce3191
JP		 617 int res;
618
619 res = lock_trace(task);
a9712bc1
AV		 620 if (res)
621 return res;
ebcb6734
RM		 622
623 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
09d93bd6 624 seq_puts(m, "running\n");
a9712bc1 625 else if (nr < 0)
09d93bd6 626 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
a9712bc1 627 else
09d93bd6 628 seq_printf(m,
ebcb6734
RM		 629 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
630 nr,
631 args[0], args[1], args[2], args[3], args[4], args[5],
632 sp, pc);
a9712bc1 633 unlock_trace(task);
25ce3191
JP		 634
635 return 0;
ebcb6734
RM		 636}
637#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
638
1da177e4
LT		 639/************************************************************************/
640/* Here the fs part begins */
641/************************************************************************/
642
643/* permission checks */
778c1144 644static int proc_fd_access_allowed(struct inode *inode)
1da177e4 645{
778c1144
EB		 646 struct task_struct *task;
647 int allowed = 0;
df26c40e
EB		 648 /* Allow access to a task's file descriptors if it is us or we
649 * may use ptrace attach to the process and find out that
650 * information.
778c1144
EB		 651 */
652 task = get_proc_task(inode);
df26c40e 653 if (task) {
caaee623 654 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
778c1144 655 put_task_struct(task);
df26c40e 656 }
778c1144 657 return allowed;
1da177e4
LT		 658}
659
6b4e306a 660int proc_setattr(struct dentry *dentry, struct iattr *attr)
6d76fa58
LT		 661{
662 int error;
2b0143b5 663 struct inode *inode = d_inode(dentry);
6d76fa58
LT		 664
665 if (attr->ia_valid & ATTR_MODE)
666 return -EPERM;
667
31051c85 668 error = setattr_prepare(dentry, attr);
1025774c
CH		 669 if (error)
670 return error;
671
1025774c
CH		 672 setattr_copy(inode, attr);
673 mark_inode_dirty(inode);
674 return 0;
6d76fa58
LT		 675}
676
0499680a
VK		 677/*
678 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
679 * or euid/egid (for hide_pid_min=2)?
680 */
681static bool has_pid_permissions(struct pid_namespace *pid,
682 struct task_struct *task,
683 int hide_pid_min)
684{
685 if (pid->hide_pid < hide_pid_min)
686 return true;
687 if (in_group_p(pid->pid_gid))
688 return true;
caaee623 689 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
0499680a
VK		 690}
691
692
693static int proc_pid_permission(struct inode *inode, int mask)
694{
76f668be 695 struct pid_namespace *pid = proc_pid_ns(inode);
0499680a
VK		 696 struct task_struct *task;
697 bool has_perms;
698
699 task = get_proc_task(inode);
a2ef990a
XF		 700 if (!task)
701 return -ESRCH;
796f571b 702 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
0499680a
VK		 703 put_task_struct(task);
704
705 if (!has_perms) {
796f571b 706 if (pid->hide_pid == HIDEPID_INVISIBLE) {
0499680a
VK		 707 /*
708 * Let's make getdents(), stat(), and open()
709 * consistent with each other. If a process
710 * may not stat() a file, it shouldn't be seen
711 * in procfs at all.
712 */
713 return -ENOENT;
714 }
715
716 return -EPERM;
717 }
718 return generic_permission(inode, mask);
719}
720
721
722
c5ef1c42 723static const struct inode_operations proc_def_inode_operations = {
6d76fa58
LT		 724 .setattr = proc_setattr,
725};
726
be614086
EB		 727static int proc_single_show(struct seq_file *m, void *v)
728{
729 struct inode *inode = m->private;
76f668be
CH		 730 struct pid_namespace *ns = proc_pid_ns(inode);
731 struct pid *pid = proc_pid(inode);
be614086
EB		 732 struct task_struct *task;
733 int ret;
734
be614086
EB		 735 task = get_pid_task(pid, PIDTYPE_PID);
736 if (!task)
737 return -ESRCH;
738
739 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
740
741 put_task_struct(task);
742 return ret;
743}
744
745static int proc_single_open(struct inode *inode, struct file *filp)
746{
c6a34058 747 return single_open(filp, proc_single_show, inode);
be614086
EB		 748}
749
750static const struct file_operations proc_single_file_operations = {
751 .open = proc_single_open,
752 .read = seq_read,
753 .llseek = seq_lseek,
754 .release = single_release,
755};
756
5381e169
ON		 757
758struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
1da177e4 759{
5381e169
ON		 760 struct task_struct *task = get_proc_task(inode);
761 struct mm_struct *mm = ERR_PTR(-ESRCH);
e268337d 762
5381e169 763 if (task) {
caaee623 764 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
5381e169 765 put_task_struct(task);
e268337d 766
5381e169
ON		 767 if (!IS_ERR_OR_NULL(mm)) {
768 /* ensure this mm_struct can't be freed */
f1f10076 769 mmgrab(mm);
5381e169
ON		 770 /* but do not pin its memory */
771 mmput(mm);
772 }
773 }
774
775 return mm;
776}
777
778static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
779{
780 struct mm_struct *mm = proc_mem_open(inode, mode);
e268337d
LT		 781
782 if (IS_ERR(mm))
783 return PTR_ERR(mm);
784
e268337d 785 file->private_data = mm;
1da177e4
LT		 786 return 0;
787}
788
b409e578
CW		 789static int mem_open(struct inode *inode, struct file *file)
790{
bc452b4b
DH		 791 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
792
793 /* OK to pass negative loff_t, we can catch out-of-range */
794 file->f_mode |= FMODE_UNSIGNED_OFFSET;
795
796 return ret;
b409e578
CW		 797}
798
572d34b9
ON		 799static ssize_t mem_rw(struct file *file, char __user *buf,
800 size_t count, loff_t *ppos, int write)
1da177e4 801{
e268337d 802 struct mm_struct *mm = file->private_data;
572d34b9
ON		 803 unsigned long addr = *ppos;
804 ssize_t copied;
1da177e4 805 char *page;
272ddc8b 806 unsigned int flags;
1da177e4 807
e268337d
LT		 808 if (!mm)
809 return 0;
99f89551 810
0ee931c4 811 page = (char *)__get_free_page(GFP_KERNEL);
30cd8903 812 if (!page)
e268337d 813 return -ENOMEM;
1da177e4 814
f7ca54f4 815 copied = 0;
388f7934 816 if (!mmget_not_zero(mm))
6d08f2c7
ON		 817 goto free;
818
f511c0b1 819 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
6347e8d5 820
1da177e4 821 while (count > 0) {
572d34b9 822 int this_len = min_t(int, count, PAGE_SIZE);
1da177e4 823
572d34b9 824 if (write && copy_from_user(page, buf, this_len)) {
1da177e4
LT		 825 copied = -EFAULT;
826 break;
827 }
572d34b9 828
6347e8d5 829 this_len = access_remote_vm(mm, addr, page, this_len, flags);
572d34b9 830 if (!this_len) {
1da177e4
LT		 831 if (!copied)
832 copied = -EIO;
833 break;
834 }
572d34b9
ON		 835
836 if (!write && copy_to_user(buf, page, this_len)) {
837 copied = -EFAULT;
838 break;
839 }
840
841 buf += this_len;
842 addr += this_len;
843 copied += this_len;
844 count -= this_len;
1da177e4 845 }
572d34b9 846 *ppos = addr;
30cd8903 847
6d08f2c7
ON		 848 mmput(mm);
849free:
30cd8903 850 free_page((unsigned long) page);
1da177e4
LT		 851 return copied;
852}
1da177e4 853
572d34b9
ON		 854static ssize_t mem_read(struct file *file, char __user *buf,
855 size_t count, loff_t *ppos)
856{
857 return mem_rw(file, buf, count, ppos, 0);
858}
859
860static ssize_t mem_write(struct file *file, const char __user *buf,
861 size_t count, loff_t *ppos)
862{
863 return mem_rw(file, (char __user*)buf, count, ppos, 1);
864}
865
85863e47 866loff_t mem_lseek(struct file *file, loff_t offset, int orig)
1da177e4
LT		 867{
868 switch (orig) {
869 case 0:
870 file->f_pos = offset;
871 break;
872 case 1:
873 file->f_pos += offset;
874 break;
875 default:
876 return -EINVAL;
877 }
878 force_successful_syscall_return();
879 return file->f_pos;
880}
881
e268337d
LT		 882static int mem_release(struct inode *inode, struct file *file)
883{
884 struct mm_struct *mm = file->private_data;
71879d3c 885 if (mm)
6d08f2c7 886 mmdrop(mm);
e268337d
LT		 887 return 0;
888}
889
00977a59 890static const struct file_operations proc_mem_operations = {
1da177e4
LT		 891 .llseek = mem_lseek,
892 .read = mem_read,
893 .write = mem_write,
894 .open = mem_open,
e268337d 895 .release = mem_release,
1da177e4
LT		 896};
897
b409e578
CW		 898static int environ_open(struct inode *inode, struct file *file)
899{
900 return __mem_open(inode, file, PTRACE_MODE_READ);
901}
902
315e28c8
JP		 903static ssize_t environ_read(struct file *file, char __user *buf,
904 size_t count, loff_t *ppos)
905{
315e28c8
JP		 906 char *page;
907 unsigned long src = *ppos;
b409e578
CW		 908 int ret = 0;
909 struct mm_struct *mm = file->private_data;
a3b609ef 910 unsigned long env_start, env_end;
315e28c8 911
8148a73c
MK		 912 /* Ensure the process spawned far enough to have an environment. */
913 if (!mm || !mm->env_end)
b409e578 914 return 0;
315e28c8 915
0ee931c4 916 page = (char *)__get_free_page(GFP_KERNEL);
315e28c8 917 if (!page)
b409e578 918 return -ENOMEM;
315e28c8 919
d6f64b89 920 ret = 0;
388f7934 921 if (!mmget_not_zero(mm))
b409e578 922 goto free;
a3b609ef 923
88aa7cc6 924 spin_lock(&mm->arg_lock);
a3b609ef
MG		 925 env_start = mm->env_start;
926 env_end = mm->env_end;
88aa7cc6 927 spin_unlock(&mm->arg_lock);
a3b609ef 928
315e28c8 929 while (count > 0) {
e8905ec2
DH		 930 size_t this_len, max_len;
931 int retval;
315e28c8 932
a3b609ef 933 if (src >= (env_end - env_start))
315e28c8
JP		 934 break;
935
a3b609ef 936 this_len = env_end - (env_start + src);
e8905ec2
DH		 937
938 max_len = min_t(size_t, PAGE_SIZE, count);
939 this_len = min(max_len, this_len);
315e28c8 940
7f7ccc2c 941 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
315e28c8
JP		 942
943 if (retval <= 0) {
944 ret = retval;
945 break;
946 }
947
948 if (copy_to_user(buf, page, retval)) {
949 ret = -EFAULT;
950 break;
951 }
952
953 ret += retval;
954 src += retval;
955 buf += retval;
956 count -= retval;
957 }
958 *ppos = src;
315e28c8 959 mmput(mm);
b409e578
CW		 960
961free:
315e28c8 962 free_page((unsigned long) page);
315e28c8
JP		 963 return ret;
964}
965
966static const struct file_operations proc_environ_operations = {
b409e578 967 .open = environ_open,
315e28c8 968 .read = environ_read,
87df8424 969 .llseek = generic_file_llseek,
b409e578 970 .release = mem_release,
315e28c8
JP		 971};
972
c5317167
AV		 973static int auxv_open(struct inode *inode, struct file *file)
974{
975 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
976}
977
978static ssize_t auxv_read(struct file *file, char __user *buf,
979 size_t count, loff_t *ppos)
980{
981 struct mm_struct *mm = file->private_data;
982 unsigned int nwords = 0;
06b2849d
LY		 983
984 if (!mm)
985 return 0;
c5317167
AV		 986 do {
987 nwords += 2;
988 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
989 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
990 nwords * sizeof(mm->saved_auxv[0]));
991}
992
993static const struct file_operations proc_auxv_operations = {
994 .open = auxv_open,
995 .read = auxv_read,
996 .llseek = generic_file_llseek,
997 .release = mem_release,
998};
999
fa0cbbf1
DR		 1000static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1001 loff_t *ppos)
1002{
496ad9aa 1003 struct task_struct *task = get_proc_task(file_inode(file));
fa0cbbf1
DR		 1004 char buffer[PROC_NUMBUF];
1005 int oom_adj = OOM_ADJUST_MIN;
1006 size_t len;
fa0cbbf1
DR		 1007
1008 if (!task)
1009 return -ESRCH;
f913da59
MH		 1010 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1011 oom_adj = OOM_ADJUST_MAX;
1012 else
1013 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1014 OOM_SCORE_ADJ_MAX;
fa0cbbf1
DR		 1015 put_task_struct(task);
1016 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1017 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1018}
1019
1d5f0acb
MH		 1020static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1021{
1022 static DEFINE_MUTEX(oom_adj_mutex);
44a70ade 1023 struct mm_struct *mm = NULL;
1d5f0acb
MH		 1024 struct task_struct *task;
1025 int err = 0;
1026
1027 task = get_proc_task(file_inode(file));
1028 if (!task)
1029 return -ESRCH;
1030
1031 mutex_lock(&oom_adj_mutex);
1032 if (legacy) {
1033 if (oom_adj < task->signal->oom_score_adj &&
1034 !capable(CAP_SYS_RESOURCE)) {
1035 err = -EACCES;
1036 goto err_unlock;
1037 }
1038 /*
1039 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1040 * /proc/pid/oom_score_adj instead.
1041 */
1042 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1043 current->comm, task_pid_nr(current), task_pid_nr(task),
1044 task_pid_nr(task));
1045 } else {
1046 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1047 !capable(CAP_SYS_RESOURCE)) {
1048 err = -EACCES;
1049 goto err_unlock;
1050 }
1051 }
1052
44a70ade
MH		 1053 /*
1054 * Make sure we will check other processes sharing the mm if this is
1055 * not vfrok which wants its own oom_score_adj.
1056 * pin the mm so it doesn't go away and get reused after task_unlock
1057 */
1058 if (!task->vfork_done) {
1059 struct task_struct *p = find_lock_task_mm(task);
1060
1061 if (p) {
1062 if (atomic_read(&p->mm->mm_users) > 1) {
1063 mm = p->mm;
f1f10076 1064 mmgrab(mm);
44a70ade
MH		 1065 }
1066 task_unlock(p);
1067 }
1068 }
1069
1d5f0acb
MH		 1070 task->signal->oom_score_adj = oom_adj;
1071 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1072 task->signal->oom_score_adj_min = (short)oom_adj;
1073 trace_oom_score_adj_update(task);
44a70ade
MH		 1074
1075 if (mm) {
1076 struct task_struct *p;
1077
1078 rcu_read_lock();
1079 for_each_process(p) {
1080 if (same_thread_group(task, p))
1081 continue;
1082
1083 /* do not touch kernel threads or the global init */
1084 if (p->flags & PF_KTHREAD || is_global_init(p))
1085 continue;
1086
1087 task_lock(p);
1088 if (!p->vfork_done && process_shares_mm(p, mm)) {
1089 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",
1090 task_pid_nr(p), p->comm,
1091 p->signal->oom_score_adj, oom_adj,
1092 task_pid_nr(task), task->comm);
1093 p->signal->oom_score_adj = oom_adj;
1094 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1095 p->signal->oom_score_adj_min = (short)oom_adj;
1096 }
1097 task_unlock(p);
1098 }
1099 rcu_read_unlock();
1100 mmdrop(mm);
1101 }
1d5f0acb
MH		 1102err_unlock:
1103 mutex_unlock(&oom_adj_mutex);
1104 put_task_struct(task);
1105 return err;
1106}
f913da59 1107
b72bdfa7
DR		 1108/*
1109 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1110 * kernels. The effective policy is defined by oom_score_adj, which has a
1111 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1112 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1113 * Processes that become oom disabled via oom_adj will still be oom disabled
1114 * with this implementation.
1115 *
1116 * oom_adj cannot be removed since existing userspace binaries use it.
1117 */
fa0cbbf1
DR		 1118static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1119 size_t count, loff_t *ppos)
1120{
fa0cbbf1
DR		 1121 char buffer[PROC_NUMBUF];
1122 int oom_adj;
fa0cbbf1
DR		 1123 int err;
1124
1125 memset(buffer, 0, sizeof(buffer));
1126 if (count > sizeof(buffer) - 1)
1127 count = sizeof(buffer) - 1;
1128 if (copy_from_user(buffer, buf, count)) {
1129 err = -EFAULT;
1130 goto out;
1131 }
1132
1133 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1134 if (err)
1135 goto out;
1136 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1137 oom_adj != OOM_DISABLE) {
1138 err = -EINVAL;
1139 goto out;
1140 }
1141
fa0cbbf1
DR		 1142 /*
1143 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1144 * value is always attainable.
1145 */
1146 if (oom_adj == OOM_ADJUST_MAX)
1147 oom_adj = OOM_SCORE_ADJ_MAX;
1148 else
1149 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1150
1d5f0acb 1151 err = __set_oom_adj(file, oom_adj, true);
fa0cbbf1
DR		 1152out:
1153 return err < 0 ? err : count;
1154}
1155
1156static const struct file_operations proc_oom_adj_operations = {
1157 .read = oom_adj_read,
1158 .write = oom_adj_write,
1159 .llseek = generic_file_llseek,
1160};
1161
a63d83f4
DR		 1162static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1163 size_t count, loff_t *ppos)
1164{
496ad9aa 1165 struct task_struct *task = get_proc_task(file_inode(file));
a63d83f4 1166 char buffer[PROC_NUMBUF];
a9c58b90 1167 short oom_score_adj = OOM_SCORE_ADJ_MIN;
a63d83f4
DR		 1168 size_t len;
1169
1170 if (!task)
1171 return -ESRCH;
f913da59 1172 oom_score_adj = task->signal->oom_score_adj;
a63d83f4 1173 put_task_struct(task);
a9c58b90 1174 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
a63d83f4
DR		 1175 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1176}
1177
1178static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1179 size_t count, loff_t *ppos)
1180{
a63d83f4 1181 char buffer[PROC_NUMBUF];
0a8cb8e3 1182 int oom_score_adj;
a63d83f4
DR		 1183 int err;
1184
1185 memset(buffer, 0, sizeof(buffer));
1186 if (count > sizeof(buffer) - 1)
1187 count = sizeof(buffer) - 1;
723548bf
DR		 1188 if (copy_from_user(buffer, buf, count)) {
1189 err = -EFAULT;
1190 goto out;
1191 }
a63d83f4 1192
0a8cb8e3 1193 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
a63d83f4 1194 if (err)
723548bf 1195 goto out;
a63d83f4 1196 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
723548bf
DR		 1197 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1198 err = -EINVAL;
1199 goto out;
1200 }
a63d83f4 1201
1d5f0acb 1202 err = __set_oom_adj(file, oom_score_adj, false);
723548bf
DR		 1203out:
1204 return err < 0 ? err : count;
a63d83f4
DR		 1205}
1206
1207static const struct file_operations proc_oom_score_adj_operations = {
1208 .read = oom_score_adj_read,
1209 .write = oom_score_adj_write,
6038f373 1210 .llseek = default_llseek,
a63d83f4
DR		 1211};
1212
1da177e4 1213#ifdef CONFIG_AUDITSYSCALL
b4eb4f7f 1214#define TMPBUFLEN 11
1da177e4
LT		 1215static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1216 size_t count, loff_t *ppos)
1217{
496ad9aa 1218 struct inode * inode = file_inode(file);
99f89551 1219 struct task_struct *task = get_proc_task(inode);
1da177e4
LT		 1220 ssize_t length;
1221 char tmpbuf[TMPBUFLEN];
1222
99f89551
EB		 1223 if (!task)
1224 return -ESRCH;
1da177e4 1225 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
e1760bd5
EB		 1226 from_kuid(file->f_cred->user_ns,
1227 audit_get_loginuid(task)));
99f89551 1228 put_task_struct(task);
1da177e4
LT		 1229 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1230}
1231
1232static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1233 size_t count, loff_t *ppos)
1234{
496ad9aa 1235 struct inode * inode = file_inode(file);
1da177e4 1236 uid_t loginuid;
e1760bd5 1237 kuid_t kloginuid;
774636e1 1238 int rv;
1da177e4 1239
7dc52157
PM		 1240 rcu_read_lock();
1241 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1242 rcu_read_unlock();
1da177e4 1243 return -EPERM;
7dc52157
PM		 1244 }
1245 rcu_read_unlock();
1da177e4 1246
1da177e4
LT		 1247 if (*ppos != 0) {
1248 /* No partial writes. */
1249 return -EINVAL;
1250 }
1da177e4 1251
774636e1
AD		 1252 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1253 if (rv < 0)
1254 return rv;
81407c84
EP		 1255
1256 /* is userspace tring to explicitly UNSET the loginuid? */
1257 if (loginuid == AUDIT_UID_UNSET) {
1258 kloginuid = INVALID_UID;
1259 } else {
1260 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
774636e1
AD		 1261 if (!uid_valid(kloginuid))
1262 return -EINVAL;
e1760bd5
EB		 1263 }
1264
774636e1
AD		 1265 rv = audit_set_loginuid(kloginuid);
1266 if (rv < 0)
1267 return rv;
1268 return count;
1da177e4
LT		 1269}
1270
00977a59 1271static const struct file_operations proc_loginuid_operations = {
1da177e4
LT		 1272 .read = proc_loginuid_read,
1273 .write = proc_loginuid_write,
87df8424 1274 .llseek = generic_file_llseek,
1da177e4 1275};
1e0bd755
EP		 1276
1277static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1278 size_t count, loff_t *ppos)
1279{
496ad9aa 1280 struct inode * inode = file_inode(file);
1e0bd755
EP		 1281 struct task_struct *task = get_proc_task(inode);
1282 ssize_t length;
1283 char tmpbuf[TMPBUFLEN];
1284
1285 if (!task)
1286 return -ESRCH;
1287 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1288 audit_get_sessionid(task));
1289 put_task_struct(task);
1290 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1291}
1292
1293static const struct file_operations proc_sessionid_operations = {
1294 .read = proc_sessionid_read,
87df8424 1295 .llseek = generic_file_llseek,
1e0bd755 1296};
1da177e4
LT		 1297#endif
1298
f4f154fd
AM		 1299#ifdef CONFIG_FAULT_INJECTION
1300static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1301 size_t count, loff_t *ppos)
1302{
496ad9aa 1303 struct task_struct *task = get_proc_task(file_inode(file));
f4f154fd
AM		 1304 char buffer[PROC_NUMBUF];
1305 size_t len;
1306 int make_it_fail;
f4f154fd
AM		 1307
1308 if (!task)
1309 return -ESRCH;
1310 make_it_fail = task->make_it_fail;
1311 put_task_struct(task);
1312
1313 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
0c28f287
AM		 1314
1315 return simple_read_from_buffer(buf, count, ppos, buffer, len);
f4f154fd
AM		 1316}
1317
1318static ssize_t proc_fault_inject_write(struct file * file,
1319 const char __user * buf, size_t count, loff_t *ppos)
1320{
1321 struct task_struct *task;
774636e1 1322 char buffer[PROC_NUMBUF];
f4f154fd 1323 int make_it_fail;
774636e1 1324 int rv;
f4f154fd
AM		 1325
1326 if (!capable(CAP_SYS_RESOURCE))
1327 return -EPERM;
1328 memset(buffer, 0, sizeof(buffer));
1329 if (count > sizeof(buffer) - 1)
1330 count = sizeof(buffer) - 1;
1331 if (copy_from_user(buffer, buf, count))
1332 return -EFAULT;
774636e1
AD		 1333 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1334 if (rv < 0)
1335 return rv;
16caed31
DJ		 1336 if (make_it_fail < 0 || make_it_fail > 1)
1337 return -EINVAL;
1338
496ad9aa 1339 task = get_proc_task(file_inode(file));
f4f154fd
AM		 1340 if (!task)
1341 return -ESRCH;
1342 task->make_it_fail = make_it_fail;
1343 put_task_struct(task);
cba8aafe
VL		 1344
1345 return count;
f4f154fd
AM		 1346}
1347
00977a59 1348static const struct file_operations proc_fault_inject_operations = {
f4f154fd
AM		 1349 .read = proc_fault_inject_read,
1350 .write = proc_fault_inject_write,
87df8424 1351 .llseek = generic_file_llseek,
f4f154fd 1352};
e41d5818
DV		 1353
1354static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1355 size_t count, loff_t *ppos)
1356{
1357 struct task_struct *task;
9049f2f6
AM		 1358 int err;
1359 unsigned int n;
e41d5818 1360
1203c8e6
AM		 1361 err = kstrtouint_from_user(buf, count, 0, &n);
1362 if (err)
1363 return err;
1364
e41d5818
DV		 1365 task = get_proc_task(file_inode(file));
1366 if (!task)
1367 return -ESRCH;
9f7118b2 1368 task->fail_nth = n;
e41d5818 1369 put_task_struct(task);
1203c8e6 1370
e41d5818
DV		 1371 return count;
1372}
1373
1374static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1375 size_t count, loff_t *ppos)
1376{
1377 struct task_struct *task;
bfc74093
AM		 1378 char numbuf[PROC_NUMBUF];
1379 ssize_t len;
e41d5818
DV		 1380
1381 task = get_proc_task(file_inode(file));
1382 if (!task)
1383 return -ESRCH;
9f7118b2 1384 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1203c8e6 1385 put_task_struct(task);
a44937fe 1386 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
e41d5818
DV		 1387}
1388
1389static const struct file_operations proc_fail_nth_operations = {
1390 .read = proc_fail_nth_read,
1391 .write = proc_fail_nth_write,
1392};
f4f154fd
AM		 1393#endif
1394
9745512c 1395
43ae34cb
IM		 1396#ifdef CONFIG_SCHED_DEBUG
1397/*
1398 * Print out various scheduling related per-task fields:
1399 */
1400static int sched_show(struct seq_file *m, void *v)
1401{
1402 struct inode *inode = m->private;
76f668be 1403 struct pid_namespace *ns = proc_pid_ns(inode);
43ae34cb
IM		 1404 struct task_struct *p;
1405
43ae34cb
IM		 1406 p = get_proc_task(inode);
1407 if (!p)
1408 return -ESRCH;
74dc3384 1409 proc_sched_show_task(p, ns, m);
43ae34cb
IM		 1410
1411 put_task_struct(p);
1412
1413 return 0;
1414}
1415
1416static ssize_t
1417sched_write(struct file *file, const char __user *buf,
1418 size_t count, loff_t *offset)
1419{
496ad9aa 1420 struct inode *inode = file_inode(file);
43ae34cb
IM		 1421 struct task_struct *p;
1422
43ae34cb
IM		 1423 p = get_proc_task(inode);
1424 if (!p)
1425 return -ESRCH;
1426 proc_sched_set_task(p);
1427
1428 put_task_struct(p);
1429
1430 return count;
1431}
1432
1433static int sched_open(struct inode *inode, struct file *filp)
1434{
c6a34058 1435 return single_open(filp, sched_show, inode);
43ae34cb
IM		 1436}
1437
1438static const struct file_operations proc_pid_sched_operations = {
1439 .open = sched_open,
1440 .read = seq_read,
1441 .write = sched_write,
1442 .llseek = seq_lseek,
5ea473a1 1443 .release = single_release,
43ae34cb
IM		 1444};
1445
1446#endif
1447
5091faa4
MG		 1448#ifdef CONFIG_SCHED_AUTOGROUP
1449/*
1450 * Print out autogroup related information:
1451 */
1452static int sched_autogroup_show(struct seq_file *m, void *v)
1453{
1454 struct inode *inode = m->private;
1455 struct task_struct *p;
1456
1457 p = get_proc_task(inode);
1458 if (!p)
1459 return -ESRCH;
1460 proc_sched_autogroup_show_task(p, m);
1461
1462 put_task_struct(p);
1463
1464 return 0;
1465}
1466
1467static ssize_t
1468sched_autogroup_write(struct file *file, const char __user *buf,
1469 size_t count, loff_t *offset)
1470{
496ad9aa 1471 struct inode *inode = file_inode(file);
5091faa4
MG		 1472 struct task_struct *p;
1473 char buffer[PROC_NUMBUF];
0a8cb8e3 1474 int nice;
5091faa4
MG		 1475 int err;
1476
1477 memset(buffer, 0, sizeof(buffer));
1478 if (count > sizeof(buffer) - 1)
1479 count = sizeof(buffer) - 1;
1480 if (copy_from_user(buffer, buf, count))
1481 return -EFAULT;
1482
0a8cb8e3
AD		 1483 err = kstrtoint(strstrip(buffer), 0, &nice);
1484 if (err < 0)
1485 return err;
5091faa4
MG		 1486
1487 p = get_proc_task(inode);
1488 if (!p)
1489 return -ESRCH;
1490
2e5b5b3a 1491 err = proc_sched_autogroup_set_nice(p, nice);
5091faa4
MG		 1492 if (err)
1493 count = err;
1494
1495 put_task_struct(p);
1496
1497 return count;
1498}
1499
1500static int sched_autogroup_open(struct inode *inode, struct file *filp)
1501{
1502 int ret;
1503
1504 ret = single_open(filp, sched_autogroup_show, NULL);
1505 if (!ret) {
1506 struct seq_file *m = filp->private_data;
1507
1508 m->private = inode;
1509 }
1510 return ret;
1511}
1512
1513static const struct file_operations proc_pid_sched_autogroup_operations = {
1514 .open = sched_autogroup_open,
1515 .read = seq_read,
1516 .write = sched_autogroup_write,
1517 .llseek = seq_lseek,
1518 .release = single_release,
1519};
1520
1521#endif /* CONFIG_SCHED_AUTOGROUP */
1522
4614a696 1523static ssize_t comm_write(struct file *file, const char __user *buf,
1524 size_t count, loff_t *offset)
1525{
496ad9aa 1526 struct inode *inode = file_inode(file);
4614a696 1527 struct task_struct *p;
1528 char buffer[TASK_COMM_LEN];
830e0fc9 1529 const size_t maxlen = sizeof(buffer) - 1;
4614a696 1530
1531 memset(buffer, 0, sizeof(buffer));
830e0fc9 1532 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
4614a696 1533 return -EFAULT;
1534
1535 p = get_proc_task(inode);
1536 if (!p)
1537 return -ESRCH;
1538
1539 if (same_thread_group(current, p))
1540 set_task_comm(p, buffer);
1541 else
1542 count = -EINVAL;
1543
1544 put_task_struct(p);
1545
1546 return count;
1547}
1548
1549static int comm_show(struct seq_file *m, void *v)
1550{
1551 struct inode *inode = m->private;
1552 struct task_struct *p;
1553
1554 p = get_proc_task(inode);
1555 if (!p)
1556 return -ESRCH;
1557
88b72b31
TH		 1558 proc_task_name(m, p, false);
1559 seq_putc(m, '\n');
4614a696 1560
1561 put_task_struct(p);
1562
1563 return 0;
1564}
1565
1566static int comm_open(struct inode *inode, struct file *filp)
1567{
c6a34058 1568 return single_open(filp, comm_show, inode);
4614a696 1569}
1570
1571static const struct file_operations proc_pid_set_comm_operations = {
1572 .open = comm_open,
1573 .read = seq_read,
1574 .write = comm_write,
1575 .llseek = seq_lseek,
1576 .release = single_release,
1577};
1578
7773fbc5 1579static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
925d1c40
MH		 1580{
1581 struct task_struct *task;
925d1c40
MH		 1582 struct file *exe_file;
1583
2b0143b5 1584 task = get_proc_task(d_inode(dentry));
925d1c40
MH		 1585 if (!task)
1586 return -ENOENT;
cd81a917 1587 exe_file = get_task_exe_file(task);
925d1c40 1588 put_task_struct(task);
925d1c40
MH		 1589 if (exe_file) {
1590 *exe_path = exe_file->f_path;
1591 path_get(&exe_file->f_path);
1592 fput(exe_file);
1593 return 0;
1594 } else
1595 return -ENOENT;
1596}
1597
6b255391 1598static const char *proc_pid_get_link(struct dentry *dentry,
fceef393
AV		 1599 struct inode *inode,
1600 struct delayed_call *done)
1da177e4 1601{
408ef013 1602 struct path path;
1da177e4
LT		 1603 int error = -EACCES;
1604
6b255391
AV		 1605 if (!dentry)
1606 return ERR_PTR(-ECHILD);
1607
778c1144
EB		 1608 /* Are we allowed to snoop on the tasks file descriptors? */
1609 if (!proc_fd_access_allowed(inode))
1da177e4 1610 goto out;
1da177e4 1611
408ef013
CH		 1612 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1613 if (error)
1614 goto out;
1615
6e77137b 1616 nd_jump_link(&path);
408ef013 1617 return NULL;
1da177e4 1618out:
008b150a 1619 return ERR_PTR(error);
1da177e4
LT		 1620}
1621
3dcd25f3 1622static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1da177e4 1623{
0ee931c4 1624 char *tmp = (char *)__get_free_page(GFP_KERNEL);
3dcd25f3 1625 char *pathname;
1da177e4
LT		 1626 int len;
1627
1628 if (!tmp)
1629 return -ENOMEM;
0c28f287 1630
7b2a69ba 1631 pathname = d_path(path, tmp, PAGE_SIZE);
3dcd25f3
JB		 1632 len = PTR_ERR(pathname);
1633 if (IS_ERR(pathname))
1da177e4 1634 goto out;
3dcd25f3 1635 len = tmp + PAGE_SIZE - 1 - pathname;
1da177e4
LT		 1636
1637 if (len > buflen)
1638 len = buflen;
3dcd25f3 1639 if (copy_to_user(buffer, pathname, len))
1da177e4
LT		 1640 len = -EFAULT;
1641 out:
1642 free_page((unsigned long)tmp);
1643 return len;
1644}
1645
1646static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1647{
1648 int error = -EACCES;
2b0143b5 1649 struct inode *inode = d_inode(dentry);
3dcd25f3 1650 struct path path;
1da177e4 1651
778c1144
EB		 1652 /* Are we allowed to snoop on the tasks file descriptors? */
1653 if (!proc_fd_access_allowed(inode))
1da177e4 1654 goto out;
1da177e4 1655
7773fbc5 1656 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1da177e4
LT		 1657 if (error)
1658 goto out;
1659
3dcd25f3
JB		 1660 error = do_proc_readlink(&path, buffer, buflen);
1661 path_put(&path);
1da177e4 1662out:
1da177e4
LT		 1663 return error;
1664}
1665
faf60af1 1666const struct inode_operations proc_pid_link_inode_operations = {
1da177e4 1667 .readlink = proc_pid_readlink,
6b255391 1668 .get_link = proc_pid_get_link,
6d76fa58 1669 .setattr = proc_setattr,
1da177e4
LT		 1670};
1671
28a6d671
EB		 1672
1673/* building an inode */
1674
c6eb50d2 1675void task_dump_owner(struct task_struct *task, umode_t mode,
68eb94f1
EB		 1676 kuid_t *ruid, kgid_t *rgid)
1677{
1678 /* Depending on the state of dumpable compute who should own a
1679 * proc file for a task.
1680 */
1681 const struct cred *cred;
1682 kuid_t uid;
1683 kgid_t gid;
1684
2e0ad552
AD		 1685 if (unlikely(task->flags & PF_KTHREAD)) {
1686 *ruid = GLOBAL_ROOT_UID;
1687 *rgid = GLOBAL_ROOT_GID;
1688 return;
1689 }
1690
68eb94f1
EB		 1691 /* Default to the tasks effective ownership */
1692 rcu_read_lock();
1693 cred = __task_cred(task);
1694 uid = cred->euid;
1695 gid = cred->egid;
1696 rcu_read_unlock();
1697
1698 /*
1699 * Before the /proc/pid/status file was created the only way to read
1700 * the effective uid of a /process was to stat /proc/pid. Reading
1701 * /proc/pid/status is slow enough that procps and other packages
1702 * kept stating /proc/pid. To keep the rules in /proc simple I have
1703 * made this apply to all per process world readable and executable
1704 * directories.
1705 */
1706 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1707 struct mm_struct *mm;
1708 task_lock(task);
1709 mm = task->mm;
1710 /* Make non-dumpable tasks owned by some root */
1711 if (mm) {
1712 if (get_dumpable(mm) != SUID_DUMP_USER) {
1713 struct user_namespace *user_ns = mm->user_ns;
1714
1715 uid = make_kuid(user_ns, 0);
1716 if (!uid_valid(uid))
1717 uid = GLOBAL_ROOT_UID;
1718
1719 gid = make_kgid(user_ns, 0);
1720 if (!gid_valid(gid))
1721 gid = GLOBAL_ROOT_GID;
1722 }
1723 } else {
1724 uid = GLOBAL_ROOT_UID;
1725 gid = GLOBAL_ROOT_GID;
1726 }
1727 task_unlock(task);
1728 }
1729 *ruid = uid;
1730 *rgid = gid;
1731}
1732
db978da8
AG		 1733struct inode *proc_pid_make_inode(struct super_block * sb,
1734 struct task_struct *task, umode_t mode)
28a6d671
EB		 1735{
1736 struct inode * inode;
1737 struct proc_inode *ei;
1da177e4 1738
28a6d671 1739 /* We need a new inode */
1da177e4 1740
28a6d671
EB		 1741 inode = new_inode(sb);
1742 if (!inode)
1743 goto out;
1744
1745 /* Common stuff */
1746 ei = PROC_I(inode);
db978da8 1747 inode->i_mode = mode;
85fe4025 1748 inode->i_ino = get_next_ino();
078cd827 1749 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
28a6d671
EB		 1750 inode->i_op = &proc_def_inode_operations;
1751
1752 /*
1753 * grab the reference to task.
1754 */
1a657f78 1755 ei->pid = get_task_pid(task, PIDTYPE_PID);
28a6d671
EB		 1756 if (!ei->pid)
1757 goto out_unlock;
1758
68eb94f1 1759 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
28a6d671
EB		 1760 security_task_to_inode(task, inode);
1761
1da177e4 1762out:
28a6d671
EB		 1763 return inode;
1764
1765out_unlock:
1766 iput(inode);
1767 return NULL;
1da177e4
LT		 1768}
1769
a528d35e
DH		 1770int pid_getattr(const struct path *path, struct kstat *stat,
1771 u32 request_mask, unsigned int query_flags)
1da177e4 1772{
a528d35e 1773 struct inode *inode = d_inode(path->dentry);
76f668be 1774 struct pid_namespace *pid = proc_pid_ns(inode);
28a6d671 1775 struct task_struct *task;
c69e8d9c 1776
28a6d671 1777 generic_fillattr(inode, stat);
1da177e4 1778
dcb0f222
EB		 1779 stat->uid = GLOBAL_ROOT_UID;
1780 stat->gid = GLOBAL_ROOT_GID;
94116929 1781 rcu_read_lock();
28a6d671
EB		 1782 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1783 if (task) {
796f571b 1784 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
0499680a
VK		 1785 rcu_read_unlock();
1786 /*
1787 * This doesn't prevent learning whether PID exists,
1788 * it only makes getattr() consistent with readdir().
1789 */
1790 return -ENOENT;
1791 }
68eb94f1 1792 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1da177e4 1793 }
28a6d671 1794 rcu_read_unlock();
d6e71144 1795 return 0;
1da177e4
LT		 1796}
1797
1da177e4
LT		 1798/* dentry stuff */
1799
1800/*
1bbc5513
AV		 1801 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1802 */
1803void pid_update_inode(struct task_struct *task, struct inode *inode)
1804{
1805 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1806
1807 inode->i_mode &= ~(S_ISUID | S_ISGID);
1808 security_task_to_inode(task, inode);
1809}
1810
1811/*
1da177e4
LT		 1812 * Rewrite the inode's ownerships here because the owning task may have
1813 * performed a setuid(), etc.
99f89551 1814 *
1da177e4 1815 */
1bbc5513 1816static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1da177e4 1817{
34286d66
NP		 1818 struct inode *inode;
1819 struct task_struct *task;
c69e8d9c 1820
0b728e19 1821 if (flags & LOOKUP_RCU)
34286d66
NP		 1822 return -ECHILD;
1823
2b0143b5 1824 inode = d_inode(dentry);
34286d66
NP		 1825 task = get_proc_task(inode);
1826
99f89551 1827 if (task) {
1bbc5513 1828 pid_update_inode(task, inode);
99f89551 1829 put_task_struct(task);
1da177e4
LT		 1830 return 1;
1831 }
1da177e4
LT		 1832 return 0;
1833}
1834
d855a4b7
ON		 1835static inline bool proc_inode_is_dead(struct inode *inode)
1836{
1837 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1838}
1839
1dd704b6
DH		 1840int pid_delete_dentry(const struct dentry *dentry)
1841{
1842 /* Is the task we represent dead?
1843 * If so, then don't put the dentry on the lru list,
1844 * kill it immediately.
1845 */
2b0143b5 1846 return proc_inode_is_dead(d_inode(dentry));
1dd704b6
DH		 1847}
1848
6b4e306a 1849const struct dentry_operations pid_dentry_operations =
28a6d671
EB		 1850{
1851 .d_revalidate = pid_revalidate,
1852 .d_delete = pid_delete_dentry,
1853};
1854
1855/* Lookups */
1856
1c0d04c9
EB		 1857/*
1858 * Fill a directory entry.
1859 *
1860 * If possible create the dcache entry and derive our inode number and
1861 * file type from dcache entry.
1862 *
1863 * Since all of the proc inode numbers are dynamically generated, the inode
1864 * numbers do not exist until the inode is cache. This means creating the
1865 * the dcache entry in readdir is necessary to keep the inode numbers
1866 * reported by readdir in sync with the inode numbers reported
1867 * by stat.
1868 */
f0c3b509 1869bool proc_fill_cache(struct file *file, struct dir_context *ctx,
a4ef3895 1870 const char *name, unsigned int len,
c5141e6d 1871 instantiate_t instantiate, struct task_struct *task, const void *ptr)
61a28784 1872{
f0c3b509 1873 struct dentry *child, *dir = file->f_path.dentry;
1df98b8b 1874 struct qstr qname = QSTR_INIT(name, len);
61a28784 1875 struct inode *inode;
0168b9e3
AV		 1876 unsigned type = DT_UNKNOWN;
1877 ino_t ino = 1;
61a28784 1878
1df98b8b 1879 child = d_hash_and_lookup(dir, &qname);
61a28784 1880 if (!child) {
3781764b
AV		 1881 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1882 child = d_alloc_parallel(dir, &qname, &wq);
1883 if (IS_ERR(child))
1df98b8b 1884 goto end_instantiate;
3781764b 1885 if (d_in_lookup(child)) {
0168b9e3
AV		 1886 struct dentry *res;
1887 res = instantiate(child, task, ptr);
3781764b 1888 d_lookup_done(child);
0168b9e3
AV		 1889 if (unlikely(res)) {
1890 dput(child);
1891 child = res;
d85b399b
AV		 1892 if (IS_ERR(child))
1893 goto end_instantiate;
3781764b 1894 }
61a28784
EB		 1895 }
1896 }
2b0143b5 1897 inode = d_inode(child);
147ce699
AV		 1898 ino = inode->i_ino;
1899 type = inode->i_mode >> 12;
61a28784 1900 dput(child);
d85b399b 1901end_instantiate:
f0c3b509 1902 return dir_emit(ctx, name, len, ino, type);
61a28784
EB		 1903}
1904
640708a2
PE		 1905/*
1906 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1907 * which represent vma start and end addresses.
1908 */
1909static int dname_to_vma_addr(struct dentry *dentry,
1910 unsigned long *start, unsigned long *end)
1911{
ac7f1061
AD		 1912 const char *str = dentry->d_name.name;
1913 unsigned long long sval, eval;
1914 unsigned int len;
1915
35318db5
AD		 1916 if (str[0] == '0' && str[1] != '-')
1917 return -EINVAL;
ac7f1061
AD		 1918 len = _parse_integer(str, 16, &sval);
1919 if (len & KSTRTOX_OVERFLOW)
1920 return -EINVAL;
1921 if (sval != (unsigned long)sval)
1922 return -EINVAL;
1923 str += len;
1924
1925 if (*str != '-')
640708a2 1926 return -EINVAL;
ac7f1061
AD		 1927 str++;
1928
35318db5
AD		 1929 if (str[0] == '0' && str[1])
1930 return -EINVAL;
ac7f1061
AD		 1931 len = _parse_integer(str, 16, &eval);
1932 if (len & KSTRTOX_OVERFLOW)
1933 return -EINVAL;
1934 if (eval != (unsigned long)eval)
1935 return -EINVAL;
1936 str += len;
1937
1938 if (*str != '\0')
1939 return -EINVAL;
1940
1941 *start = sval;
1942 *end = eval;
640708a2
PE		 1943
1944 return 0;
1945}
1946
0b728e19 1947static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
640708a2
PE		 1948{
1949 unsigned long vm_start, vm_end;
1950 bool exact_vma_exists = false;
1951 struct mm_struct *mm = NULL;
1952 struct task_struct *task;
640708a2
PE		 1953 struct inode *inode;
1954 int status = 0;
1955
0b728e19 1956 if (flags & LOOKUP_RCU)
640708a2
PE		 1957 return -ECHILD;
1958
2b0143b5 1959 inode = d_inode(dentry);
640708a2
PE		 1960 task = get_proc_task(inode);
1961 if (!task)
1962 goto out_notask;
1963
caaee623 1964 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2344bec7 1965 if (IS_ERR_OR_NULL(mm))
640708a2
PE		 1966 goto out;
1967
1968 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1969 down_read(&mm->mmap_sem);
1970 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1971 up_read(&mm->mmap_sem);
1972 }
1973
1974 mmput(mm);
1975
1976 if (exact_vma_exists) {
68eb94f1
EB		 1977 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1978
640708a2
PE		 1979 security_task_to_inode(task, inode);
1980 status = 1;
1981 }
1982
1983out:
1984 put_task_struct(task);
1985
1986out_notask:
640708a2
PE		 1987 return status;
1988}
1989
1990static const struct dentry_operations tid_map_files_dentry_operations = {
1991 .d_revalidate = map_files_d_revalidate,
1992 .d_delete = pid_delete_dentry,
1993};
1994
6b255391 1995static int map_files_get_link(struct dentry *dentry, struct path *path)
640708a2
PE		 1996{
1997 unsigned long vm_start, vm_end;
1998 struct vm_area_struct *vma;
1999 struct task_struct *task;
2000 struct mm_struct *mm;
2001 int rc;
2002
2003 rc = -ENOENT;
2b0143b5 2004 task = get_proc_task(d_inode(dentry));
640708a2
PE		 2005 if (!task)
2006 goto out;
2007
2008 mm = get_task_mm(task);
2009 put_task_struct(task);
2010 if (!mm)
2011 goto out;
2012
2013 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2014 if (rc)
2015 goto out_mmput;
2016
70335abb 2017 rc = -ENOENT;
640708a2
PE		 2018 down_read(&mm->mmap_sem);
2019 vma = find_exact_vma(mm, vm_start, vm_end);
2020 if (vma && vma->vm_file) {
2021 *path = vma->vm_file->f_path;
2022 path_get(path);
2023 rc = 0;
2024 }
2025 up_read(&mm->mmap_sem);
2026
2027out_mmput:
2028 mmput(mm);
2029out:
2030 return rc;
2031}
2032
2033struct map_files_info {
20d28cde
AD		 2034 unsigned long start;
2035 unsigned long end;
7b540d06 2036 fmode_t mode;
640708a2
PE		 2037};
2038
bdb4d100
CO		 2039/*
2040 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2041 * symlinks may be used to bypass permissions on ancestor directories in the
2042 * path to the file in question.
2043 */
2044static const char *
6b255391 2045proc_map_files_get_link(struct dentry *dentry,
fceef393
AV		 2046 struct inode *inode,
2047 struct delayed_call *done)
bdb4d100
CO		 2048{
2049 if (!capable(CAP_SYS_ADMIN))
2050 return ERR_PTR(-EPERM);
2051
fceef393 2052 return proc_pid_get_link(dentry, inode, done);
bdb4d100
CO		 2053}
2054
2055/*
6b255391 2056 * Identical to proc_pid_link_inode_operations except for get_link()
bdb4d100
CO		 2057 */
2058static const struct inode_operations proc_map_files_link_inode_operations = {
2059 .readlink = proc_pid_readlink,
6b255391 2060 .get_link = proc_map_files_get_link,
bdb4d100
CO		 2061 .setattr = proc_setattr,
2062};
2063
0168b9e3
AV		 2064static struct dentry *
2065proc_map_files_instantiate(struct dentry *dentry,
640708a2
PE		 2066 struct task_struct *task, const void *ptr)
2067{
7b540d06 2068 fmode_t mode = (fmode_t)(unsigned long)ptr;
640708a2
PE		 2069 struct proc_inode *ei;
2070 struct inode *inode;
2071
0168b9e3 2072 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
db978da8
AG		 2073 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2074 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
640708a2 2075 if (!inode)
0168b9e3 2076 return ERR_PTR(-ENOENT);
640708a2
PE		 2077
2078 ei = PROC_I(inode);
6b255391 2079 ei->op.proc_get_link = map_files_get_link;
640708a2 2080
bdb4d100 2081 inode->i_op = &proc_map_files_link_inode_operations;
640708a2 2082 inode->i_size = 64;
640708a2
PE		 2083
2084 d_set_d_op(dentry, &tid_map_files_dentry_operations);
0168b9e3 2085 return d_splice_alias(inode, dentry);
640708a2
PE		 2086}
2087
2088static struct dentry *proc_map_files_lookup(struct inode *dir,
00cd8dd3 2089 struct dentry *dentry, unsigned int flags)
640708a2
PE		 2090{
2091 unsigned long vm_start, vm_end;
2092 struct vm_area_struct *vma;
2093 struct task_struct *task;
0168b9e3 2094 struct dentry *result;
640708a2
PE		 2095 struct mm_struct *mm;
2096
0168b9e3 2097 result = ERR_PTR(-ENOENT);
640708a2
PE		 2098 task = get_proc_task(dir);
2099 if (!task)
2100 goto out;
2101
0168b9e3 2102 result = ERR_PTR(-EACCES);
caaee623 2103 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
640708a2
PE		 2104 goto out_put_task;
2105
0168b9e3 2106 result = ERR_PTR(-ENOENT);
640708a2 2107 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
eb94cd96 2108 goto out_put_task;
640708a2
PE		 2109
2110 mm = get_task_mm(task);
2111 if (!mm)
eb94cd96 2112 goto out_put_task;
640708a2
PE		 2113
2114 down_read(&mm->mmap_sem);
2115 vma = find_exact_vma(mm, vm_start, vm_end);
2116 if (!vma)
2117 goto out_no_vma;
2118
05f56484 2119 if (vma->vm_file)
0168b9e3 2120 result = proc_map_files_instantiate(dentry, task,
05f56484 2121 (void *)(unsigned long)vma->vm_file->f_mode);
640708a2
PE		 2122
2123out_no_vma:
2124 up_read(&mm->mmap_sem);
2125 mmput(mm);
640708a2
PE		 2126out_put_task:
2127 put_task_struct(task);
2128out:
0168b9e3 2129 return result;
640708a2
PE		 2130}
2131
2132static const struct inode_operations proc_map_files_inode_operations = {
2133 .lookup = proc_map_files_lookup,
2134 .permission = proc_fd_permission,
2135 .setattr = proc_setattr,
2136};
2137
2138static int
f0c3b509 2139proc_map_files_readdir(struct file *file, struct dir_context *ctx)
640708a2 2140{
640708a2
PE		 2141 struct vm_area_struct *vma;
2142 struct task_struct *task;
2143 struct mm_struct *mm;
f0c3b509
AV		 2144 unsigned long nr_files, pos, i;
2145 struct flex_array *fa = NULL;
2146 struct map_files_info info;
2147 struct map_files_info *p;
640708a2
PE		 2148 int ret;
2149
640708a2 2150 ret = -ENOENT;
f0c3b509 2151 task = get_proc_task(file_inode(file));
640708a2
PE		 2152 if (!task)
2153 goto out;
2154
2155 ret = -EACCES;
caaee623 2156 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
640708a2
PE		 2157 goto out_put_task;
2158
2159 ret = 0;
f0c3b509
AV		 2160 if (!dir_emit_dots(file, ctx))
2161 goto out_put_task;
640708a2 2162
f0c3b509
AV		 2163 mm = get_task_mm(task);
2164 if (!mm)
2165 goto out_put_task;
2166 down_read(&mm->mmap_sem);
640708a2 2167
f0c3b509 2168 nr_files = 0;
640708a2 2169
f0c3b509
AV		 2170 /*
2171 * We need two passes here:
2172 *
2173 * 1) Collect vmas of mapped files with mmap_sem taken
2174 * 2) Release mmap_sem and instantiate entries
2175 *
2176 * otherwise we get lockdep complained, since filldir()
2177 * routine might require mmap_sem taken in might_fault().
2178 */
640708a2 2179
f0c3b509
AV		 2180 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2181 if (vma->vm_file && ++pos > ctx->pos)
2182 nr_files++;
2183 }
2184
2185 if (nr_files) {
2186 fa = flex_array_alloc(sizeof(info), nr_files,
2187 GFP_KERNEL);
2188 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2189 GFP_KERNEL)) {
2190 ret = -ENOMEM;
2191 if (fa)
2192 flex_array_free(fa);
2193 up_read(&mm->mmap_sem);
2194 mmput(mm);
2195 goto out_put_task;
640708a2 2196 }
f0c3b509
AV		 2197 for (i = 0, vma = mm->mmap, pos = 2; vma;
2198 vma = vma->vm_next) {
2199 if (!vma->vm_file)
2200 continue;
2201 if (++pos <= ctx->pos)
2202 continue;
2203
20d28cde
AD		 2204 info.start = vma->vm_start;
2205 info.end = vma->vm_end;
f0c3b509 2206 info.mode = vma->vm_file->f_mode;
f0c3b509
AV		 2207 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2208 BUG();
640708a2 2209 }
640708a2 2210 }
f0c3b509 2211 up_read(&mm->mmap_sem);
fe079a5e 2212 mmput(mm);
f0c3b509
AV		 2213
2214 for (i = 0; i < nr_files; i++) {
20d28cde
AD		 2215 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2216 unsigned int len;
2217
f0c3b509 2218 p = flex_array_get(fa, i);
20d28cde 2219 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
f0c3b509 2220 if (!proc_fill_cache(file, ctx,
20d28cde 2221 buf, len,
f0c3b509
AV		 2222 proc_map_files_instantiate,
2223 task,
2224 (void *)(unsigned long)p->mode))
2225 break;
2226 ctx->pos++;
640708a2 2227 }
f0c3b509
AV		 2228 if (fa)
2229 flex_array_free(fa);
640708a2 2230
640708a2
PE		 2231out_put_task:
2232 put_task_struct(task);
2233out:
2234 return ret;
2235}
2236
2237static const struct file_operations proc_map_files_operations = {
2238 .read = generic_read_dir,
f50752ea
AV		 2239 .iterate_shared = proc_map_files_readdir,
2240 .llseek = generic_file_llseek,
640708a2
PE		 2241};
2242
b18b6a9c 2243#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
48f6a7a5
PE		 2244struct timers_private {
2245 struct pid *pid;
2246 struct task_struct *task;
2247 struct sighand_struct *sighand;
57b8015e 2248 struct pid_namespace *ns;
48f6a7a5
PE		 2249 unsigned long flags;
2250};
2251
2252static void *timers_start(struct seq_file *m, loff_t *pos)
2253{
2254 struct timers_private *tp = m->private;
2255
2256 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2257 if (!tp->task)
2258 return ERR_PTR(-ESRCH);
2259
2260 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2261 if (!tp->sighand)
2262 return ERR_PTR(-ESRCH);
2263
2264 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2265}
2266
2267static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2268{
2269 struct timers_private *tp = m->private;
2270 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2271}
2272
2273static void timers_stop(struct seq_file *m, void *v)
2274{
2275 struct timers_private *tp = m->private;
2276
2277 if (tp->sighand) {
2278 unlock_task_sighand(tp->task, &tp->flags);
2279 tp->sighand = NULL;
2280 }
2281
2282 if (tp->task) {
2283 put_task_struct(tp->task);
2284 tp->task = NULL;
2285 }
2286}
2287
2288static int show_timer(struct seq_file *m, void *v)
2289{
2290 struct k_itimer *timer;
57b8015e
PE		 2291 struct timers_private *tp = m->private;
2292 int notify;
cedbccab 2293 static const char * const nstr[] = {
57b8015e
PE		 2294 [SIGEV_SIGNAL] = "signal",
2295 [SIGEV_NONE] = "none",
2296 [SIGEV_THREAD] = "thread",
2297 };
48f6a7a5
PE		 2298
2299 timer = list_entry((struct list_head *)v, struct k_itimer, list);
57b8015e
PE		 2300 notify = timer->it_sigev_notify;
2301
48f6a7a5 2302 seq_printf(m, "ID: %d\n", timer->it_id);
ba3edf1f 2303 seq_printf(m, "signal: %d/%px\n",
25ce3191
JP		 2304 timer->sigq->info.si_signo,
2305 timer->sigq->info.si_value.sival_ptr);
57b8015e 2306 seq_printf(m, "notify: %s/%s.%d\n",
25ce3191
JP		 2307 nstr[notify & ~SIGEV_THREAD_ID],
2308 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2309 pid_nr_ns(timer->it_pid, tp->ns));
15ef0298 2310 seq_printf(m, "ClockID: %d\n", timer->it_clock);
48f6a7a5
PE		 2311
2312 return 0;
2313}
2314
2315static const struct seq_operations proc_timers_seq_ops = {
2316 .start = timers_start,
2317 .next = timers_next,
2318 .stop = timers_stop,
2319 .show = show_timer,
2320};
2321
2322static int proc_timers_open(struct inode *inode, struct file *file)
2323{
2324 struct timers_private *tp;
2325
2326 tp = __seq_open_private(file, &proc_timers_seq_ops,
2327 sizeof(struct timers_private));
2328 if (!tp)
2329 return -ENOMEM;
2330
2331 tp->pid = proc_pid(inode);
76f668be 2332 tp->ns = proc_pid_ns(inode);
48f6a7a5
PE		 2333 return 0;
2334}
2335
2336static const struct file_operations proc_timers_operations = {
2337 .open = proc_timers_open,
2338 .read = seq_read,
2339 .llseek = seq_lseek,
2340 .release = seq_release_private,
2341};
b5946bea 2342#endif
640708a2 2343
5de23d43
JS		 2344static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2345 size_t count, loff_t *offset)
2346{
2347 struct inode *inode = file_inode(file);
2348 struct task_struct *p;
2349 u64 slack_ns;
2350 int err;
2351
2352 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2353 if (err < 0)
2354 return err;
2355
2356 p = get_proc_task(inode);
2357 if (!p)
2358 return -ESRCH;
2359
4b2bd5fe 2360 if (p != current) {
8da0b4f6
BG		 2361 rcu_read_lock();
2362 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2363 rcu_read_unlock();
4b2bd5fe
JS		 2364 count = -EPERM;
2365 goto out;
2366 }
8da0b4f6 2367 rcu_read_unlock();
5de23d43 2368
4b2bd5fe
JS		 2369 err = security_task_setscheduler(p);
2370 if (err) {
2371 count = err;
2372 goto out;
2373 }
904763e1
JS		 2374 }
2375
7abbaf94
JS		 2376 task_lock(p);
2377 if (slack_ns == 0)
2378 p->timer_slack_ns = p->default_timer_slack_ns;
2379 else
2380 p->timer_slack_ns = slack_ns;
2381 task_unlock(p);
2382
2383out:
5de23d43
JS		 2384 put_task_struct(p);
2385
2386 return count;
2387}
2388
2389static int timerslack_ns_show(struct seq_file *m, void *v)
2390{
2391 struct inode *inode = m->private;
2392 struct task_struct *p;
7abbaf94 2393 int err = 0;
5de23d43
JS		 2394
2395 p = get_proc_task(inode);
2396 if (!p)
2397 return -ESRCH;
2398
4b2bd5fe 2399 if (p != current) {
8da0b4f6
BG		 2400 rcu_read_lock();
2401 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2402 rcu_read_unlock();
4b2bd5fe
JS		 2403 err = -EPERM;
2404 goto out;
2405 }
8da0b4f6
BG		 2406 rcu_read_unlock();
2407
4b2bd5fe
JS		 2408 err = security_task_getscheduler(p);
2409 if (err)
2410 goto out;
2411 }
904763e1 2412
7abbaf94
JS		 2413 task_lock(p);
2414 seq_printf(m, "%llu\n", p->timer_slack_ns);
2415 task_unlock(p);
2416
2417out:
5de23d43
JS		 2418 put_task_struct(p);
2419
2420 return err;
2421}
2422
2423static int timerslack_ns_open(struct inode *inode, struct file *filp)
2424{
2425 return single_open(filp, timerslack_ns_show, inode);
2426}
2427
2428static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2429 .open = timerslack_ns_open,
2430 .read = seq_read,
2431 .write = timerslack_ns_write,
2432 .llseek = seq_lseek,
2433 .release = single_release,
2434};
2435
0168b9e3
AV		 2436static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2437 struct task_struct *task, const void *ptr)
444ceed8 2438{
c5141e6d 2439 const struct pid_entry *p = ptr;
444ceed8
EB		 2440 struct inode *inode;
2441 struct proc_inode *ei;
444ceed8 2442
0168b9e3 2443 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
444ceed8 2444 if (!inode)
0168b9e3 2445 return ERR_PTR(-ENOENT);
444ceed8
EB		 2446
2447 ei = PROC_I(inode);
444ceed8 2448 if (S_ISDIR(inode->i_mode))
bfe86848 2449 set_nlink(inode, 2); /* Use getattr to fix if necessary */
444ceed8
EB		 2450 if (p->iop)
2451 inode->i_op = p->iop;
2452 if (p->fop)
2453 inode->i_fop = p->fop;
2454 ei->op = p->op;
1bbc5513 2455 pid_update_inode(task, inode);
fb045adb 2456 d_set_d_op(dentry, &pid_dentry_operations);
0168b9e3 2457 return d_splice_alias(inode, dentry);
444ceed8
EB		 2458}
2459
1da177e4
LT		 2460static struct dentry *proc_pident_lookup(struct inode *dir,
2461 struct dentry *dentry,
c5141e6d 2462 const struct pid_entry *ents,
7bcd6b0e 2463 unsigned int nents)
1da177e4 2464{
99f89551 2465 struct task_struct *task = get_proc_task(dir);
c5141e6d 2466 const struct pid_entry *p, *last;
0168b9e3 2467 struct dentry *res = ERR_PTR(-ENOENT);
1da177e4 2468
99f89551
EB		 2469 if (!task)
2470 goto out_no_task;
1da177e4 2471
20cdc894
EB		 2472 /*
2473 * Yes, it does not scale. And it should not. Don't add
2474 * new entries into /proc/<tgid>/ without very good reasons.
2475 */
bac5f5d5
AD		 2476 last = &ents[nents];
2477 for (p = ents; p < last; p++) {
1da177e4
LT		 2478 if (p->len != dentry->d_name.len)
2479 continue;
26b95137
AD		 2480 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2481 res = proc_pident_instantiate(dentry, task, p);
1da177e4 2482 break;
26b95137 2483 }
1da177e4 2484 }
99f89551
EB		 2485 put_task_struct(task);
2486out_no_task:
0168b9e3 2487 return res;
1da177e4
LT		 2488}
2489
f0c3b509 2490static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
c5141e6d 2491 const struct pid_entry *ents, unsigned int nents)
28a6d671 2492{
f0c3b509
AV		 2493 struct task_struct *task = get_proc_task(file_inode(file));
2494 const struct pid_entry *p;
28a6d671 2495
28a6d671 2496 if (!task)
f0c3b509 2497 return -ENOENT;
28a6d671 2498
f0c3b509
AV		 2499 if (!dir_emit_dots(file, ctx))
2500 goto out;
2501
2502 if (ctx->pos >= nents + 2)
2503 goto out;
28a6d671 2504
bac5f5d5 2505 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
f0c3b509
AV		 2506 if (!proc_fill_cache(file, ctx, p->name, p->len,
2507 proc_pident_instantiate, task, p))
2508 break;
2509 ctx->pos++;
2510 }
28a6d671 2511out:
61a28784 2512 put_task_struct(task);
f0c3b509 2513 return 0;
1da177e4
LT		 2514}
2515
28a6d671
EB		 2516#ifdef CONFIG_SECURITY
2517static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2518 size_t count, loff_t *ppos)
2519{
496ad9aa 2520 struct inode * inode = file_inode(file);
04ff9708 2521 char *p = NULL;
28a6d671
EB		 2522 ssize_t length;
2523 struct task_struct *task = get_proc_task(inode);
2524
28a6d671 2525 if (!task)
04ff9708 2526 return -ESRCH;
28a6d671
EB		 2527
2528 length = security_getprocattr(task,
2fddfeef 2529 (char*)file->f_path.dentry->d_name.name,
04ff9708 2530 &p);
28a6d671 2531 put_task_struct(task);
04ff9708
AV		 2532 if (length > 0)
2533 length = simple_read_from_buffer(buf, count, ppos, p, length);
2534 kfree(p);
28a6d671 2535 return length;
1da177e4
LT		 2536}
2537
28a6d671
EB		 2538static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2539 size_t count, loff_t *ppos)
2540{
496ad9aa 2541 struct inode * inode = file_inode(file);
41089b6d 2542 struct task_struct *task;
bb646cdb 2543 void *page;
41089b6d 2544 int rv;
b21507e2 2545
41089b6d
AD		 2546 rcu_read_lock();
2547 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2548 if (!task) {
2549 rcu_read_unlock();
2550 return -ESRCH;
2551 }
b21507e2 2552 /* A task may only write its own attributes. */
41089b6d
AD		 2553 if (current != task) {
2554 rcu_read_unlock();
2555 return -EACCES;
2556 }
2557 rcu_read_unlock();
b21507e2 2558
28a6d671
EB		 2559 if (count > PAGE_SIZE)
2560 count = PAGE_SIZE;
2561
2562 /* No partial writes. */
28a6d671 2563 if (*ppos != 0)
41089b6d 2564 return -EINVAL;
28a6d671 2565
bb646cdb
AV		 2566 page = memdup_user(buf, count);
2567 if (IS_ERR(page)) {
41089b6d 2568 rv = PTR_ERR(page);
28a6d671 2569 goto out;
bb646cdb 2570 }
28a6d671 2571
107db7c7 2572 /* Guard against adverse ptrace interaction */
41089b6d
AD		 2573 rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2574 if (rv < 0)
107db7c7
DH		 2575 goto out_free;
2576
41089b6d 2577 rv = security_setprocattr(file->f_path.dentry->d_name.name, page, count);
b21507e2 2578 mutex_unlock(&current->signal->cred_guard_mutex);
28a6d671 2579out_free:
bb646cdb 2580 kfree(page);
28a6d671 2581out:
41089b6d 2582 return rv;
28a6d671
EB		 2583}
2584
00977a59 2585static const struct file_operations proc_pid_attr_operations = {
28a6d671
EB		 2586 .read = proc_pid_attr_read,
2587 .write = proc_pid_attr_write,
87df8424 2588 .llseek = generic_file_llseek,
28a6d671
EB		 2589};
2590
c5141e6d 2591static const struct pid_entry attr_dir_stuff[] = {
631f9c18
AD		 2592 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2593 REG("prev", S_IRUGO, proc_pid_attr_operations),
2594 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2595 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2596 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2597 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
28a6d671
EB		 2598};
2599
f0c3b509 2600static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
28a6d671 2601{
f0c3b509
AV		 2602 return proc_pident_readdir(file, ctx,
2603 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2604}
2605
00977a59 2606static const struct file_operations proc_attr_dir_operations = {
1da177e4 2607 .read = generic_read_dir,
f50752ea
AV		 2608 .iterate_shared = proc_attr_dir_readdir,
2609 .llseek = generic_file_llseek,
1da177e4
LT		 2610};
2611
72d9dcfc 2612static struct dentry *proc_attr_dir_lookup(struct inode *dir,
00cd8dd3 2613 struct dentry *dentry, unsigned int flags)
28a6d671 2614{
7bcd6b0e
EB		 2615 return proc_pident_lookup(dir, dentry,
2616 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2617}
2618
c5ef1c42 2619static const struct inode_operations proc_attr_dir_inode_operations = {
72d9dcfc 2620 .lookup = proc_attr_dir_lookup,
99f89551 2621 .getattr = pid_getattr,
6d76fa58 2622 .setattr = proc_setattr,
1da177e4
LT		 2623};
2624
28a6d671
EB		 2625#endif
2626
698ba7b5 2627#ifdef CONFIG_ELF_CORE
3cb4a0bb
KH		 2628static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2629 size_t count, loff_t *ppos)
2630{
496ad9aa 2631 struct task_struct *task = get_proc_task(file_inode(file));
3cb4a0bb
KH		 2632 struct mm_struct *mm;
2633 char buffer[PROC_NUMBUF];
2634 size_t len;
2635 int ret;
2636
2637 if (!task)
2638 return -ESRCH;
2639
2640 ret = 0;
2641 mm = get_task_mm(task);
2642 if (mm) {
2643 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2644 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2645 MMF_DUMP_FILTER_SHIFT));
2646 mmput(mm);
2647 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2648 }
2649
2650 put_task_struct(task);
2651
2652 return ret;
2653}
2654
2655static ssize_t proc_coredump_filter_write(struct file *file,
2656 const char __user *buf,
2657 size_t count,
2658 loff_t *ppos)
2659{
2660 struct task_struct *task;
2661 struct mm_struct *mm;
3cb4a0bb
KH		 2662 unsigned int val;
2663 int ret;
2664 int i;
2665 unsigned long mask;
2666
774636e1
AD		 2667 ret = kstrtouint_from_user(buf, count, 0, &val);
2668 if (ret < 0)
2669 return ret;
3cb4a0bb
KH		 2670
2671 ret = -ESRCH;
496ad9aa 2672 task = get_proc_task(file_inode(file));
3cb4a0bb
KH		 2673 if (!task)
2674 goto out_no_task;
2675
3cb4a0bb
KH		 2676 mm = get_task_mm(task);
2677 if (!mm)
2678 goto out_no_mm;
41a0c249 2679 ret = 0;
3cb4a0bb
KH		 2680
2681 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2682 if (val & mask)
2683 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2684 else
2685 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2686 }
2687
2688 mmput(mm);
2689 out_no_mm:
2690 put_task_struct(task);
2691 out_no_task:
774636e1
AD		 2692 if (ret < 0)
2693 return ret;
2694 return count;
3cb4a0bb
KH		 2695}
2696
2697static const struct file_operations proc_coredump_filter_operations = {
2698 .read = proc_coredump_filter_read,
2699 .write = proc_coredump_filter_write,
87df8424 2700 .llseek = generic_file_llseek,
3cb4a0bb
KH		 2701};
2702#endif
2703
aba76fdb 2704#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 2705static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
297c5d92 2706{
940389b8 2707 struct task_io_accounting acct = task->ioac;
5995477a 2708 unsigned long flags;
293eb1e7 2709 int result;
5995477a 2710
293eb1e7
VK		 2711 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2712 if (result)
2713 return result;
2714
caaee623 2715 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
293eb1e7
VK		 2716 result = -EACCES;
2717 goto out_unlock;
2718 }
1d1221f3 2719
5995477a
AR		 2720 if (whole && lock_task_sighand(task, &flags)) {
2721 struct task_struct *t = task;
2722
2723 task_io_accounting_add(&acct, &task->signal->ioac);
2724 while_each_thread(task, t)
2725 task_io_accounting_add(&acct, &t->ioac);
2726
2727 unlock_task_sighand(task, &flags);
297c5d92 2728 }
25ce3191
JP		 2729 seq_printf(m,
2730 "rchar: %llu\n"
2731 "wchar: %llu\n"
2732 "syscr: %llu\n"
2733 "syscw: %llu\n"
2734 "read_bytes: %llu\n"
2735 "write_bytes: %llu\n"
2736 "cancelled_write_bytes: %llu\n",
2737 (unsigned long long)acct.rchar,
2738 (unsigned long long)acct.wchar,
2739 (unsigned long long)acct.syscr,
2740 (unsigned long long)acct.syscw,
2741 (unsigned long long)acct.read_bytes,
2742 (unsigned long long)acct.write_bytes,
2743 (unsigned long long)acct.cancelled_write_bytes);
2744 result = 0;
2745
293eb1e7
VK		 2746out_unlock:
2747 mutex_unlock(&task->signal->cred_guard_mutex);
2748 return result;
297c5d92
AR		 2749}
2750
19aadc98
AD		 2751static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2752 struct pid *pid, struct task_struct *task)
297c5d92 2753{
19aadc98 2754 return do_io_accounting(task, m, 0);
aba76fdb 2755}
297c5d92 2756
19aadc98
AD		 2757static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2758 struct pid *pid, struct task_struct *task)
297c5d92 2759{
19aadc98 2760 return do_io_accounting(task, m, 1);
297c5d92
AR		 2761}
2762#endif /* CONFIG_TASK_IO_ACCOUNTING */
aba76fdb 2763
22d917d8
EB		 2764#ifdef CONFIG_USER_NS
2765static int proc_id_map_open(struct inode *inode, struct file *file,
ccf94f1b 2766 const struct seq_operations *seq_ops)
22d917d8
EB		 2767{
2768 struct user_namespace *ns = NULL;
2769 struct task_struct *task;
2770 struct seq_file *seq;
2771 int ret = -EINVAL;
2772
2773 task = get_proc_task(inode);
2774 if (task) {
2775 rcu_read_lock();
2776 ns = get_user_ns(task_cred_xxx(task, user_ns));
2777 rcu_read_unlock();
2778 put_task_struct(task);
2779 }
2780 if (!ns)
2781 goto err;
2782
2783 ret = seq_open(file, seq_ops);
2784 if (ret)
2785 goto err_put_ns;
2786
2787 seq = file->private_data;
2788 seq->private = ns;
2789
2790 return 0;
2791err_put_ns:
2792 put_user_ns(ns);
2793err:
2794 return ret;
2795}
2796
2797static int proc_id_map_release(struct inode *inode, struct file *file)
2798{
2799 struct seq_file *seq = file->private_data;
2800 struct user_namespace *ns = seq->private;
2801 put_user_ns(ns);
2802 return seq_release(inode, file);
2803}
2804
2805static int proc_uid_map_open(struct inode *inode, struct file *file)
2806{
2807 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2808}
2809
2810static int proc_gid_map_open(struct inode *inode, struct file *file)
2811{
2812 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2813}
2814
f76d207a
EB		 2815static int proc_projid_map_open(struct inode *inode, struct file *file)
2816{
2817 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2818}
2819
22d917d8
EB		 2820static const struct file_operations proc_uid_map_operations = {
2821 .open = proc_uid_map_open,
2822 .write = proc_uid_map_write,
2823 .read = seq_read,
2824 .llseek = seq_lseek,
2825 .release = proc_id_map_release,
2826};
2827
2828static const struct file_operations proc_gid_map_operations = {
2829 .open = proc_gid_map_open,
2830 .write = proc_gid_map_write,
2831 .read = seq_read,
2832 .llseek = seq_lseek,
2833 .release = proc_id_map_release,
2834};
f76d207a
EB		 2835
2836static const struct file_operations proc_projid_map_operations = {
2837 .open = proc_projid_map_open,
2838 .write = proc_projid_map_write,
2839 .read = seq_read,
2840 .llseek = seq_lseek,
2841 .release = proc_id_map_release,
2842};
9cc46516
EB		 2843
2844static int proc_setgroups_open(struct inode *inode, struct file *file)
2845{
2846 struct user_namespace *ns = NULL;
2847 struct task_struct *task;
2848 int ret;
2849
2850 ret = -ESRCH;
2851 task = get_proc_task(inode);
2852 if (task) {
2853 rcu_read_lock();
2854 ns = get_user_ns(task_cred_xxx(task, user_ns));
2855 rcu_read_unlock();
2856 put_task_struct(task);
2857 }
2858 if (!ns)
2859 goto err;
2860
2861 if (file->f_mode & FMODE_WRITE) {
2862 ret = -EACCES;
2863 if (!ns_capable(ns, CAP_SYS_ADMIN))
2864 goto err_put_ns;
2865 }
2866
2867 ret = single_open(file, &proc_setgroups_show, ns);
2868 if (ret)
2869 goto err_put_ns;
2870
2871 return 0;
2872err_put_ns:
2873 put_user_ns(ns);
2874err:
2875 return ret;
2876}
2877
2878static int proc_setgroups_release(struct inode *inode, struct file *file)
2879{
2880 struct seq_file *seq = file->private_data;
2881 struct user_namespace *ns = seq->private;
2882 int ret = single_release(inode, file);
2883 put_user_ns(ns);
2884 return ret;
2885}
2886
2887static const struct file_operations proc_setgroups_operations = {
2888 .open = proc_setgroups_open,
2889 .write = proc_setgroups_write,
2890 .read = seq_read,
2891 .llseek = seq_lseek,
2892 .release = proc_setgroups_release,
2893};
22d917d8
EB		 2894#endif /* CONFIG_USER_NS */
2895
47830723
KC		 2896static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2897 struct pid *pid, struct task_struct *task)
2898{
a9712bc1
AV		 2899 int err = lock_trace(task);
2900 if (!err) {
2901 seq_printf(m, "%08x\n", task->personality);
2902 unlock_trace(task);
2903 }
2904 return err;
47830723
KC		 2905}
2906
7c23b330
JP		 2907#ifdef CONFIG_LIVEPATCH
2908static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2909 struct pid *pid, struct task_struct *task)
2910{
2911 seq_printf(m, "%d\n", task->patch_state);
2912 return 0;
2913}
2914#endif /* CONFIG_LIVEPATCH */
2915
c8d12627
AP		 2916#ifdef CONFIG_STACKLEAK_METRICS
2917static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
2918 struct pid *pid, struct task_struct *task)
2919{
2920 unsigned long prev_depth = THREAD_SIZE -
2921 (task->prev_lowest_stack & (THREAD_SIZE - 1));
2922 unsigned long depth = THREAD_SIZE -
2923 (task->lowest_stack & (THREAD_SIZE - 1));
2924
2925 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
2926 prev_depth, depth);
2927 return 0;
2928}
2929#endif /* CONFIG_STACKLEAK_METRICS */
2930
28a6d671
EB		 2931/*
2932 * Thread groups
2933 */
00977a59 2934static const struct file_operations proc_task_operations;
c5ef1c42 2935static const struct inode_operations proc_task_inode_operations;
20cdc894 2936
c5141e6d 2937static const struct pid_entry tgid_base_stuff[] = {
631f9c18
AD		 2938 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2939 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
640708a2 2940 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
631f9c18 2941 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 2942 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
b2211a36 2943#ifdef CONFIG_NET
631f9c18 2944 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
b2211a36 2945#endif
631f9c18 2946 REG("environ", S_IRUSR, proc_environ_operations),
c5317167 2947 REG("auxv", S_IRUSR, proc_auxv_operations),
631f9c18 2948 ONE("status", S_IRUGO, proc_pid_status),
35a35046 2949 ONE("personality", S_IRUSR, proc_pid_personality),
1c963eb1 2950 ONE("limits", S_IRUGO, proc_pid_limits),
43ae34cb 2951#ifdef CONFIG_SCHED_DEBUG
631f9c18 2952 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
5091faa4
MG		 2953#endif
2954#ifdef CONFIG_SCHED_AUTOGROUP
2955 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
ebcb6734 2956#endif
4614a696 2957 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 2958#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6 2959 ONE("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 2960#endif
c2c0bb44 2961 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
631f9c18
AD		 2962 ONE("stat", S_IRUGO, proc_tgid_stat),
2963 ONE("statm", S_IRUGO, proc_pid_statm),
b7643757 2964 REG("maps", S_IRUGO, proc_pid_maps_operations),
28a6d671 2965#ifdef CONFIG_NUMA
b7643757 2966 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
28a6d671 2967#endif
631f9c18
AD		 2968 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2969 LNK("cwd", proc_cwd_link),
2970 LNK("root", proc_root_link),
2971 LNK("exe", proc_exe_link),
2972 REG("mounts", S_IRUGO, proc_mounts_operations),
2973 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2974 REG("mountstats", S_IRUSR, proc_mountstats_operations),
1e883281 2975#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 2976 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
b7643757 2977 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
493b0e9d 2978 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
32ed74a4 2979 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 2980#endif
2981#ifdef CONFIG_SECURITY
631f9c18 2982 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 2983#endif
2984#ifdef CONFIG_KALLSYMS
edfcd606 2985 ONE("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 2986#endif
2ec220e2 2987#ifdef CONFIG_STACKTRACE
35a35046 2988 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671 2989#endif
5968cece 2990#ifdef CONFIG_SCHED_INFO
f6e826ca 2991 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 2992#endif
9745512c 2993#ifdef CONFIG_LATENCYTOP
631f9c18 2994 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 2995#endif
8793d854 2996#ifdef CONFIG_PROC_PID_CPUSET
52de4779 2997 ONE("cpuset", S_IRUGO, proc_cpuset_show),
a424316c
PM		 2998#endif
2999#ifdef CONFIG_CGROUPS
006f4ac4 3000 ONE("cgroup", S_IRUGO, proc_cgroup_show),
28a6d671 3001#endif
6ba51e37 3002 ONE("oom_score", S_IRUGO, proc_oom_score),
fa0cbbf1 3003 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
a63d83f4 3004 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 3005#ifdef CONFIG_AUDITSYSCALL
631f9c18
AD		 3006 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3007 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 3008#endif
f4f154fd 3009#ifdef CONFIG_FAULT_INJECTION
631f9c18 3010 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
168c42bc 3011 REG("fail-nth", 0644, proc_fail_nth_operations),
f4f154fd 3012#endif
698ba7b5 3013#ifdef CONFIG_ELF_CORE
631f9c18 3014 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3cb4a0bb 3015#endif
aba76fdb 3016#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 3017 ONE("io", S_IRUSR, proc_tgid_io_accounting),
aba76fdb 3018#endif
22d917d8
EB		 3019#ifdef CONFIG_USER_NS
3020 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3021 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
f76d207a 3022 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
9cc46516 3023 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
22d917d8 3024#endif
b18b6a9c 3025#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
48f6a7a5
PE		 3026 REG("timers", S_IRUGO, proc_timers_operations),
3027#endif
5de23d43 3028 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
7c23b330
JP		 3029#ifdef CONFIG_LIVEPATCH
3030 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3031#endif
c8d12627
AP		 3032#ifdef CONFIG_STACKLEAK_METRICS
3033 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3034#endif
28a6d671 3035};
1da177e4 3036
f0c3b509 3037static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
1da177e4 3038{
f0c3b509
AV		 3039 return proc_pident_readdir(file, ctx,
3040 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 3041}
3042
00977a59 3043static const struct file_operations proc_tgid_base_operations = {
1da177e4 3044 .read = generic_read_dir,
f50752ea
AV		 3045 .iterate_shared = proc_tgid_base_readdir,
3046 .llseek = generic_file_llseek,
1da177e4
LT		 3047};
3048
00cd8dd3
AV		 3049static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3050{
7bcd6b0e
EB		 3051 return proc_pident_lookup(dir, dentry,
3052 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 3053}
3054
c5ef1c42 3055static const struct inode_operations proc_tgid_base_inode_operations = {
28a6d671 3056 .lookup = proc_tgid_base_lookup,
99f89551 3057 .getattr = pid_getattr,
6d76fa58 3058 .setattr = proc_setattr,
0499680a 3059 .permission = proc_pid_permission,
1da177e4 3060};
1da177e4 3061
60347f67 3062static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
1da177e4 3063{
48e6484d 3064 struct dentry *dentry, *leader, *dir;
e3912ac3 3065 char buf[10 + 1];
48e6484d
EB		 3066 struct qstr name;
3067
3068 name.name = buf;
e3912ac3 3069 name.len = snprintf(buf, sizeof(buf), "%u", pid);
4f522a24 3070 /* no ->d_hash() rejects on procfs */
60347f67 3071 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d 3072 if (dentry) {
bbd51924 3073 d_invalidate(dentry);
48e6484d
EB		 3074 dput(dentry);
3075 }
1da177e4 3076
c35a7f18
ON		 3077 if (pid == tgid)
3078 return;
3079
48e6484d 3080 name.name = buf;
e3912ac3 3081 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
60347f67 3082 leader = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d
EB		 3083 if (!leader)
3084 goto out;
1da177e4 3085
48e6484d
EB		 3086 name.name = "task";
3087 name.len = strlen(name.name);
3088 dir = d_hash_and_lookup(leader, &name);
3089 if (!dir)
3090 goto out_put_leader;
3091
3092 name.name = buf;
e3912ac3 3093 name.len = snprintf(buf, sizeof(buf), "%u", pid);
48e6484d
EB		 3094 dentry = d_hash_and_lookup(dir, &name);
3095 if (dentry) {
bbd51924 3096 d_invalidate(dentry);
48e6484d 3097 dput(dentry);
1da177e4 3098 }
48e6484d
EB		 3099
3100 dput(dir);
3101out_put_leader:
3102 dput(leader);
3103out:
3104 return;
1da177e4
LT		 3105}
3106
0895e91d
RD		 3107/**
3108 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3109 * @task: task that should be flushed.
3110 *
3111 * When flushing dentries from proc, one needs to flush them from global
60347f67 3112 * proc (proc_mnt) and from all the namespaces' procs this task was seen
0895e91d
RD		 3113 * in. This call is supposed to do all of this job.
3114 *
3115 * Looks in the dcache for
3116 * /proc/@pid
3117 * /proc/@tgid/task/@pid
3118 * if either directory is present flushes it and all of it'ts children
3119 * from the dcache.
3120 *
3121 * It is safe and reasonable to cache /proc entries for a task until
3122 * that task exits. After that they just clog up the dcache with
3123 * useless entries, possibly causing useful dcache entries to be
3124 * flushed instead. This routine is proved to flush those useless
3125 * dcache entries at process exit time.
3126 *
3127 * NOTE: This routine is just an optimization so it does not guarantee
3128 * that no dcache entries will exist at process exit time it
3129 * just makes it very unlikely that any will persist.
60347f67
PE		 3130 */
3131
3132void proc_flush_task(struct task_struct *task)
3133{
9fcc2d15 3134 int i;
9b4d1cbe 3135 struct pid *pid, *tgid;
130f77ec
PE		 3136 struct upid *upid;
3137
130f77ec 3138 pid = task_pid(task);
9b4d1cbe 3139 tgid = task_tgid(task);
130f77ec 3140
9fcc2d15 3141 for (i = 0; i <= pid->level; i++) {
130f77ec
PE		 3142 upid = &pid->numbers[i];
3143 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
9b4d1cbe 3144 tgid->numbers[i].nr);
130f77ec 3145 }
60347f67
PE		 3146}
3147
0168b9e3 3148static struct dentry *proc_pid_instantiate(struct dentry * dentry,
c52a47ac 3149 struct task_struct *task, const void *ptr)
444ceed8 3150{
444ceed8
EB		 3151 struct inode *inode;
3152
0168b9e3 3153 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
444ceed8 3154 if (!inode)
0168b9e3 3155 return ERR_PTR(-ENOENT);
444ceed8 3156
444ceed8
EB		 3157 inode->i_op = &proc_tgid_base_inode_operations;
3158 inode->i_fop = &proc_tgid_base_operations;
3159 inode->i_flags|=S_IMMUTABLE;
aed54175 3160
1270dd8d 3161 set_nlink(inode, nlink_tgid);
1bbc5513 3162 pid_update_inode(task, inode);
444ceed8 3163
fb045adb 3164 d_set_d_op(dentry, &pid_dentry_operations);
0168b9e3 3165 return d_splice_alias(inode, dentry);
444ceed8
EB		 3166}
3167
00cd8dd3 3168struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
1da177e4
LT		 3169{
3170 struct task_struct *task;
1da177e4 3171 unsigned tgid;
b488893a 3172 struct pid_namespace *ns;
0168b9e3 3173 struct dentry *result = ERR_PTR(-ENOENT);
1da177e4 3174
dbcdb504 3175 tgid = name_to_int(&dentry->d_name);
1da177e4
LT		 3176 if (tgid == ~0U)
3177 goto out;
3178
b488893a 3179 ns = dentry->d_sb->s_fs_info;
de758734 3180 rcu_read_lock();
b488893a 3181 task = find_task_by_pid_ns(tgid, ns);
1da177e4
LT		 3182 if (task)
3183 get_task_struct(task);
de758734 3184 rcu_read_unlock();
1da177e4
LT		 3185 if (!task)
3186 goto out;
3187
0168b9e3 3188 result = proc_pid_instantiate(dentry, task, NULL);
1da177e4 3189 put_task_struct(task);
1da177e4 3190out:
0168b9e3 3191 return result;
1da177e4
LT		 3192}
3193
1da177e4 3194/*
0804ef4b 3195 * Find the first task with tgid >= tgid
0bc58a91 3196 *
1da177e4 3197 */
19fd4bb2
EB		 3198struct tgid_iter {
3199 unsigned int tgid;
0804ef4b 3200 struct task_struct *task;
19fd4bb2
EB		 3201};
3202static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3203{
0804ef4b 3204 struct pid *pid;
1da177e4 3205
19fd4bb2
EB		 3206 if (iter.task)
3207 put_task_struct(iter.task);
454cc105 3208 rcu_read_lock();
0804ef4b 3209retry:
19fd4bb2
EB		 3210 iter.task = NULL;
3211 pid = find_ge_pid(iter.tgid, ns);
0804ef4b 3212 if (pid) {
19fd4bb2
EB		 3213 iter.tgid = pid_nr_ns(pid, ns);
3214 iter.task = pid_task(pid, PIDTYPE_PID);
0804ef4b
EB		 3215 /* What we to know is if the pid we have find is the
3216 * pid of a thread_group_leader. Testing for task
3217 * being a thread_group_leader is the obvious thing
3218 * todo but there is a window when it fails, due to
3219 * the pid transfer logic in de_thread.
3220 *
3221 * So we perform the straight forward test of seeing
3222 * if the pid we have found is the pid of a thread
3223 * group leader, and don't worry if the task we have
3224 * found doesn't happen to be a thread group leader.
3225 * As we don't care in the case of readdir.
3226 */
19fd4bb2
EB		 3227 if (!iter.task || !has_group_leader_pid(iter.task)) {
3228 iter.tgid += 1;
0804ef4b 3229 goto retry;
19fd4bb2
EB		 3230 }
3231 get_task_struct(iter.task);
0bc58a91 3232 }
454cc105 3233 rcu_read_unlock();
19fd4bb2 3234 return iter;
1da177e4
LT		 3235}
3236
0097875b 3237#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
0804ef4b 3238
1da177e4 3239/* for the /proc/ directory itself, after non-process stuff has been done */
f0c3b509 3240int proc_pid_readdir(struct file *file, struct dir_context *ctx)
1da177e4 3241{
19fd4bb2 3242 struct tgid_iter iter;
76f668be 3243 struct pid_namespace *ns = proc_pid_ns(file_inode(file));
f0c3b509 3244 loff_t pos = ctx->pos;
1da177e4 3245
021ada7d 3246 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
f0c3b509 3247 return 0;
1da177e4 3248
0097875b 3249 if (pos == TGID_OFFSET - 2) {
2b0143b5 3250 struct inode *inode = d_inode(ns->proc_self);
db963164 3251 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
f0c3b509 3252 return 0;
0097875b
EB		 3253 ctx->pos = pos = pos + 1;
3254 }
3255 if (pos == TGID_OFFSET - 1) {
2b0143b5 3256 struct inode *inode = d_inode(ns->proc_thread_self);
0097875b
EB		 3257 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3258 return 0;
3259 ctx->pos = pos = pos + 1;
021ada7d 3260 }
0097875b 3261 iter.tgid = pos - TGID_OFFSET;
19fd4bb2 3262 iter.task = NULL;
19fd4bb2
EB		 3263 for (iter = next_tgid(ns, iter);
3264 iter.task;
3265 iter.tgid += 1, iter = next_tgid(ns, iter)) {
e3912ac3 3266 char name[10 + 1];
a4ef3895 3267 unsigned int len;
3ba4bcee
ED		 3268
3269 cond_resched();
796f571b 3270 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
f0c3b509 3271 continue;
0499680a 3272
e3912ac3 3273 len = snprintf(name, sizeof(name), "%u", iter.tgid);
f0c3b509
AV		 3274 ctx->pos = iter.tgid + TGID_OFFSET;
3275 if (!proc_fill_cache(file, ctx, name, len,
3276 proc_pid_instantiate, iter.task, NULL)) {
19fd4bb2 3277 put_task_struct(iter.task);
f0c3b509 3278 return 0;
1da177e4 3279 }
0bc58a91 3280 }
f0c3b509 3281 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
0bc58a91
EB		 3282 return 0;
3283}
1da177e4 3284
1b3044e3
JD		 3285/*
3286 * proc_tid_comm_permission is a special permission function exclusively
3287 * used for the node /proc/<pid>/task/<tid>/comm.
3288 * It bypasses generic permission checks in the case where a task of the same
3289 * task group attempts to access the node.
3290 * The rationale behind this is that glibc and bionic access this node for
3291 * cross thread naming (pthread_set/getname_np(!self)). However, if
3292 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3293 * which locks out the cross thread naming implementation.
3294 * This function makes sure that the node is always accessible for members of
3295 * same thread group.
3296 */
3297static int proc_tid_comm_permission(struct inode *inode, int mask)
3298{
3299 bool is_same_tgroup;
3300 struct task_struct *task;
3301
3302 task = get_proc_task(inode);
3303 if (!task)
3304 return -ESRCH;
3305 is_same_tgroup = same_thread_group(current, task);
3306 put_task_struct(task);
3307
3308 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3309 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3310 * read or written by the members of the corresponding
3311 * thread group.
3312 */
3313 return 0;
3314 }
3315
3316 return generic_permission(inode, mask);
3317}
3318
3319static const struct inode_operations proc_tid_comm_inode_operations = {
3320 .permission = proc_tid_comm_permission,
3321};
3322
28a6d671
EB		 3323/*
3324 * Tasks
3325 */
c5141e6d 3326static const struct pid_entry tid_base_stuff[] = {
631f9c18 3327 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3835541d 3328 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 3329 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
6ba8ed79
EB		 3330#ifdef CONFIG_NET
3331 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3332#endif
631f9c18 3333 REG("environ", S_IRUSR, proc_environ_operations),
c5317167 3334 REG("auxv", S_IRUSR, proc_auxv_operations),
631f9c18 3335 ONE("status", S_IRUGO, proc_pid_status),
35a35046 3336 ONE("personality", S_IRUSR, proc_pid_personality),
1c963eb1 3337 ONE("limits", S_IRUGO, proc_pid_limits),
43ae34cb 3338#ifdef CONFIG_SCHED_DEBUG
631f9c18 3339 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
ebcb6734 3340#endif
1b3044e3
JD		 3341 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3342 &proc_tid_comm_inode_operations,
3343 &proc_pid_set_comm_operations, {}),
ebcb6734 3344#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
09d93bd6 3345 ONE("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 3346#endif
c2c0bb44 3347 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
631f9c18
AD		 3348 ONE("stat", S_IRUGO, proc_tid_stat),
3349 ONE("statm", S_IRUGO, proc_pid_statm),
871305bb 3350 REG("maps", S_IRUGO, proc_pid_maps_operations),
2e13ba54 3351#ifdef CONFIG_PROC_CHILDREN
81841161
CG		 3352 REG("children", S_IRUGO, proc_tid_children_operations),
3353#endif
28a6d671 3354#ifdef CONFIG_NUMA
871305bb 3355 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
28a6d671 3356#endif
631f9c18
AD		 3357 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3358 LNK("cwd", proc_cwd_link),
3359 LNK("root", proc_root_link),
3360 LNK("exe", proc_exe_link),
3361 REG("mounts", S_IRUGO, proc_mounts_operations),
3362 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
1e883281 3363#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 3364 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
871305bb 3365 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
493b0e9d 3366 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
32ed74a4 3367 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 3368#endif
3369#ifdef CONFIG_SECURITY
631f9c18 3370 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 3371#endif
3372#ifdef CONFIG_KALLSYMS
edfcd606 3373 ONE("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 3374#endif
2ec220e2 3375#ifdef CONFIG_STACKTRACE
35a35046 3376 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671 3377#endif
5968cece 3378#ifdef CONFIG_SCHED_INFO
f6e826ca 3379 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 3380#endif
9745512c 3381#ifdef CONFIG_LATENCYTOP
631f9c18 3382 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 3383#endif
8793d854 3384#ifdef CONFIG_PROC_PID_CPUSET
52de4779 3385 ONE("cpuset", S_IRUGO, proc_cpuset_show),
a424316c
PM		 3386#endif
3387#ifdef CONFIG_CGROUPS
006f4ac4 3388 ONE("cgroup", S_IRUGO, proc_cgroup_show),
28a6d671 3389#endif
6ba51e37 3390 ONE("oom_score", S_IRUGO, proc_oom_score),
fa0cbbf1 3391 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
a63d83f4 3392 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 3393#ifdef CONFIG_AUDITSYSCALL
631f9c18 3394 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
26ec3c64 3395 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 3396#endif
f4f154fd 3397#ifdef CONFIG_FAULT_INJECTION
631f9c18 3398 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
1203c8e6 3399 REG("fail-nth", 0644, proc_fail_nth_operations),
f4f154fd 3400#endif
297c5d92 3401#ifdef CONFIG_TASK_IO_ACCOUNTING
19aadc98 3402 ONE("io", S_IRUSR, proc_tid_io_accounting),
297c5d92 3403#endif
22d917d8
EB		 3404#ifdef CONFIG_USER_NS
3405 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3406 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
f76d207a 3407 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
9cc46516 3408 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
22d917d8 3409#endif
7c23b330
JP		 3410#ifdef CONFIG_LIVEPATCH
3411 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3412#endif
28a6d671
EB		 3413};
3414
f0c3b509 3415static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
28a6d671 3416{
f0c3b509
AV		 3417 return proc_pident_readdir(file, ctx,
3418 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 3419}
3420
00cd8dd3
AV		 3421static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3422{
7bcd6b0e
EB		 3423 return proc_pident_lookup(dir, dentry,
3424 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 3425}
3426
00977a59 3427static const struct file_operations proc_tid_base_operations = {
28a6d671 3428 .read = generic_read_dir,
f50752ea
AV		 3429 .iterate_shared = proc_tid_base_readdir,
3430 .llseek = generic_file_llseek,
28a6d671
EB		 3431};
3432
c5ef1c42 3433static const struct inode_operations proc_tid_base_inode_operations = {
28a6d671
EB		 3434 .lookup = proc_tid_base_lookup,
3435 .getattr = pid_getattr,
3436 .setattr = proc_setattr,
3437};
3438
0168b9e3
AV		 3439static struct dentry *proc_task_instantiate(struct dentry *dentry,
3440 struct task_struct *task, const void *ptr)
444ceed8 3441{
444ceed8 3442 struct inode *inode;
0168b9e3 3443 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
444ceed8 3444 if (!inode)
0168b9e3 3445 return ERR_PTR(-ENOENT);
1bbc5513 3446
444ceed8
EB		 3447 inode->i_op = &proc_tid_base_inode_operations;
3448 inode->i_fop = &proc_tid_base_operations;
1bbc5513 3449 inode->i_flags |= S_IMMUTABLE;
aed54175 3450
1270dd8d 3451 set_nlink(inode, nlink_tid);
1bbc5513 3452 pid_update_inode(task, inode);
444ceed8 3453
fb045adb 3454 d_set_d_op(dentry, &pid_dentry_operations);
0168b9e3 3455 return d_splice_alias(inode, dentry);
444ceed8
EB		 3456}
3457
00cd8dd3 3458static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
28a6d671 3459{
28a6d671
EB		 3460 struct task_struct *task;
3461 struct task_struct *leader = get_proc_task(dir);
28a6d671 3462 unsigned tid;
b488893a 3463 struct pid_namespace *ns;
0168b9e3 3464 struct dentry *result = ERR_PTR(-ENOENT);
28a6d671
EB		 3465
3466 if (!leader)
3467 goto out_no_task;
3468
dbcdb504 3469 tid = name_to_int(&dentry->d_name);
28a6d671
EB		 3470 if (tid == ~0U)
3471 goto out;
3472
b488893a 3473 ns = dentry->d_sb->s_fs_info;
28a6d671 3474 rcu_read_lock();
b488893a 3475 task = find_task_by_pid_ns(tid, ns);
28a6d671
EB		 3476 if (task)
3477 get_task_struct(task);
3478 rcu_read_unlock();
3479 if (!task)
3480 goto out;
bac0abd6 3481 if (!same_thread_group(leader, task))
28a6d671
EB		 3482 goto out_drop_task;
3483
0168b9e3 3484 result = proc_task_instantiate(dentry, task, NULL);
28a6d671
EB		 3485out_drop_task:
3486 put_task_struct(task);
3487out:
3488 put_task_struct(leader);
3489out_no_task:
0168b9e3 3490 return result;
28a6d671
EB		 3491}
3492
0bc58a91
EB		 3493/*
3494 * Find the first tid of a thread group to return to user space.
3495 *
3496 * Usually this is just the thread group leader, but if the users
3497 * buffer was too small or there was a seek into the middle of the
3498 * directory we have more work todo.
3499 *
3500 * In the case of a short read we start with find_task_by_pid.
3501 *
3502 * In the case of a seek we start with the leader and walk nr
3503 * threads past it.
3504 */
9f6e963f
ON		 3505static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3506 struct pid_namespace *ns)
0bc58a91 3507{
d855a4b7 3508 struct task_struct *pos, *task;
9f6e963f
ON		 3509 unsigned long nr = f_pos;
3510
3511 if (nr != f_pos) /* 32bit overflow? */
3512 return NULL;
1da177e4 3513
cc288738 3514 rcu_read_lock();
d855a4b7
ON		 3515 task = pid_task(pid, PIDTYPE_PID);
3516 if (!task)
3517 goto fail;
3518
3519 /* Attempt to start with the tid of a thread */
9f6e963f 3520 if (tid && nr) {
b488893a 3521 pos = find_task_by_pid_ns(tid, ns);
d855a4b7 3522 if (pos && same_thread_group(pos, task))
a872ff0c 3523 goto found;
0bc58a91 3524 }
1da177e4 3525
0bc58a91 3526 /* If nr exceeds the number of threads there is nothing todo */
9f6e963f 3527 if (nr >= get_nr_threads(task))
c986c14a 3528 goto fail;
1da177e4 3529
a872ff0c
ON		 3530 /* If we haven't found our starting place yet start
3531 * with the leader and walk nr threads forward.
0bc58a91 3532 */
d855a4b7 3533 pos = task = task->group_leader;
c986c14a 3534 do {
9f6e963f 3535 if (!nr--)
c986c14a 3536 goto found;
d855a4b7 3537 } while_each_thread(task, pos);
c986c14a
ON		 3538fail:
3539 pos = NULL;
3540 goto out;
a872ff0c
ON		 3541found:
3542 get_task_struct(pos);
3543out:
cc288738 3544 rcu_read_unlock();
0bc58a91
EB		 3545 return pos;
3546}
3547
3548/*
3549 * Find the next thread in the thread list.
3550 * Return NULL if there is an error or no next thread.
3551 *
3552 * The reference to the input task_struct is released.
3553 */
3554static struct task_struct *next_tid(struct task_struct *start)
3555{
c1df7fb8 3556 struct task_struct *pos = NULL;
cc288738 3557 rcu_read_lock();
c1df7fb8 3558 if (pid_alive(start)) {
0bc58a91 3559 pos = next_thread(start);
c1df7fb8
ON		 3560 if (thread_group_leader(pos))
3561 pos = NULL;
3562 else
3563 get_task_struct(pos);
3564 }
cc288738 3565 rcu_read_unlock();
0bc58a91
EB		 3566 put_task_struct(start);
3567 return pos;
1da177e4
LT		 3568}
3569
3570/* for the /proc/TGID/task/ directories */
f0c3b509 3571static int proc_task_readdir(struct file *file, struct dir_context *ctx)
1da177e4 3572{
d855a4b7
ON		 3573 struct inode *inode = file_inode(file);
3574 struct task_struct *task;
b488893a 3575 struct pid_namespace *ns;
f0c3b509 3576 int tid;
1da177e4 3577
d855a4b7 3578 if (proc_inode_is_dead(inode))
f0c3b509 3579 return -ENOENT;
1da177e4 3580
f0c3b509 3581 if (!dir_emit_dots(file, ctx))
d855a4b7 3582 return 0;
1da177e4 3583
0bc58a91
EB		 3584 /* f_version caches the tgid value that the last readdir call couldn't
3585 * return. lseek aka telldir automagically resets f_version to 0.
3586 */
76f668be 3587 ns = proc_pid_ns(inode);
f0c3b509
AV		 3588 tid = (int)file->f_version;
3589 file->f_version = 0;
d855a4b7 3590 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
0bc58a91 3591 task;
f0c3b509 3592 task = next_tid(task), ctx->pos++) {
e3912ac3 3593 char name[10 + 1];
a4ef3895 3594 unsigned int len;
b488893a 3595 tid = task_pid_nr_ns(task, ns);
e3912ac3 3596 len = snprintf(name, sizeof(name), "%u", tid);
f0c3b509
AV		 3597 if (!proc_fill_cache(file, ctx, name, len,
3598 proc_task_instantiate, task, NULL)) {
0bc58a91
EB		 3599 /* returning this tgid failed, save it as the first
3600 * pid for the next readir call */
f0c3b509 3601 file->f_version = (u64)tid;
0bc58a91 3602 put_task_struct(task);
1da177e4 3603 break;
0bc58a91 3604 }
1da177e4 3605 }
d855a4b7 3606
f0c3b509 3607 return 0;
1da177e4 3608}
6e66b52b 3609
a528d35e
DH		 3610static int proc_task_getattr(const struct path *path, struct kstat *stat,
3611 u32 request_mask, unsigned int query_flags)
6e66b52b 3612{
a528d35e 3613 struct inode *inode = d_inode(path->dentry);
99f89551 3614 struct task_struct *p = get_proc_task(inode);
6e66b52b
EB		 3615 generic_fillattr(inode, stat);
3616
99f89551 3617 if (p) {
99f89551 3618 stat->nlink += get_nr_threads(p);
99f89551 3619 put_task_struct(p);
6e66b52b
EB		 3620 }
3621
3622 return 0;
3623}
28a6d671 3624
c5ef1c42 3625static const struct inode_operations proc_task_inode_operations = {
28a6d671
EB		 3626 .lookup = proc_task_lookup,
3627 .getattr = proc_task_getattr,
3628 .setattr = proc_setattr,
0499680a 3629 .permission = proc_pid_permission,
28a6d671
EB		 3630};
3631
00977a59 3632static const struct file_operations proc_task_operations = {
28a6d671 3633 .read = generic_read_dir,
f50752ea
AV		 3634 .iterate_shared = proc_task_readdir,
3635 .llseek = generic_file_llseek,
28a6d671 3636};
1270dd8d
AD		 3637
3638void __init set_proc_pid_nlink(void)
3639{
3640 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3641 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3642}
Linux 6.x block layer and io_uring tree(s)