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drivers/rtc/rtc-pl031.c: configure correct wday for 2000-01-01
[linux-2.6-block.git] / fs / proc / base.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
e070ad49
ML		 14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
1da177e4
LT		 48 */
49
50#include <asm/uaccess.h>
51
1da177e4
LT		 52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
5995477a 56#include <linux/task_io_accounting_ops.h>
1da177e4 57#include <linux/init.h>
16f7e0fe 58#include <linux/capability.h>
1da177e4 59#include <linux/file.h>
9f3acc31 60#include <linux/fdtable.h>
1da177e4
LT		 61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
6b3286ed 64#include <linux/mnt_namespace.h>
1da177e4 65#include <linux/mm.h>
a63d83f4 66#include <linux/swap.h>
b835996f 67#include <linux/rcupdate.h>
1da177e4 68#include <linux/kallsyms.h>
2ec220e2 69#include <linux/stacktrace.h>
d85f50d5 70#include <linux/resource.h>
5096add8 71#include <linux/module.h>
1da177e4
LT		 72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
0d094efe 75#include <linux/tracehook.h>
a424316c 76#include <linux/cgroup.h>
1da177e4
LT		 77#include <linux/cpuset.h>
78#include <linux/audit.h>
5addc5dd 79#include <linux/poll.h>
1651e14e 80#include <linux/nsproxy.h>
8ac773b4 81#include <linux/oom.h>
3cb4a0bb 82#include <linux/elf.h>
60347f67 83#include <linux/pid_namespace.h>
5ad4e53b 84#include <linux/fs_struct.h>
5a0e3ad6 85#include <linux/slab.h>
640708a2 86#include <linux/flex_array.h>
f133ecca
CM		 87#ifdef CONFIG_HARDWALL
88#include <asm/hardwall.h>
89#endif
43d2b113 90#include <trace/events/oom.h>
1da177e4
LT		 91#include "internal.h"
92
0f2fe20f
EB		 93/* NOTE:
94 * Implementing inode permission operations in /proc is almost
95 * certainly an error. Permission checks need to happen during
96 * each system call not at open time. The reason is that most of
97 * what we wish to check for permissions in /proc varies at runtime.
98 *
99 * The classic example of a problem is opening file descriptors
100 * in /proc for a task before it execs a suid executable.
101 */
102
1da177e4 103struct pid_entry {
1da177e4 104 char *name;
c5141e6d 105 int len;
d161a13f 106 umode_t mode;
c5ef1c42 107 const struct inode_operations *iop;
00977a59 108 const struct file_operations *fop;
20cdc894 109 union proc_op op;
1da177e4
LT		 110};
111
61a28784 112#define NOD(NAME, MODE, IOP, FOP, OP) { \
20cdc894 113 .name = (NAME), \
c5141e6d 114 .len = sizeof(NAME) - 1, \
20cdc894
EB		 115 .mode = MODE, \
116 .iop = IOP, \
117 .fop = FOP, \
118 .op = OP, \
119}
120
631f9c18
AD		 121#define DIR(NAME, MODE, iops, fops) \
122 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
123#define LNK(NAME, get_link) \
61a28784 124 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
20cdc894 125 &proc_pid_link_inode_operations, NULL, \
631f9c18
AD		 126 { .proc_get_link = get_link } )
127#define REG(NAME, MODE, fops) \
128 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
129#define INF(NAME, MODE, read) \
61a28784 130 NOD(NAME, (S_IFREG|(MODE)), \
20cdc894 131 NULL, &proc_info_file_operations, \
631f9c18
AD		 132 { .proc_read = read } )
133#define ONE(NAME, MODE, show) \
be614086
EB		 134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
631f9c18 136 { .proc_show = show } )
1da177e4 137
640708a2
PE		 138static int proc_fd_permission(struct inode *inode, int mask);
139
aed54175
VN		 140/*
141 * Count the number of hardlinks for the pid_entry table, excluding the .
142 * and .. links.
143 */
144static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
145 unsigned int n)
146{
147 unsigned int i;
148 unsigned int count;
149
150 count = 0;
151 for (i = 0; i < n; ++i) {
152 if (S_ISDIR(entries[i].mode))
153 ++count;
154 }
155
156 return count;
157}
158
f7ad3c6b 159static int get_task_root(struct task_struct *task, struct path *root)
1da177e4 160{
7c2c7d99
HD		 161 int result = -ENOENT;
162
0494f6ec 163 task_lock(task);
f7ad3c6b
MS		 164 if (task->fs) {
165 get_fs_root(task->fs, root);
7c2c7d99
HD		 166 result = 0;
167 }
0494f6ec 168 task_unlock(task);
7c2c7d99 169 return result;
0494f6ec
MS		 170}
171
7773fbc5 172static int proc_cwd_link(struct dentry *dentry, struct path *path)
0494f6ec 173{
7773fbc5 174 struct task_struct *task = get_proc_task(dentry->d_inode);
0494f6ec 175 int result = -ENOENT;
99f89551
EB		 176
177 if (task) {
f7ad3c6b
MS		 178 task_lock(task);
179 if (task->fs) {
180 get_fs_pwd(task->fs, path);
181 result = 0;
182 }
183 task_unlock(task);
99f89551
EB		 184 put_task_struct(task);
185 }
1da177e4
LT		 186 return result;
187}
188
7773fbc5 189static int proc_root_link(struct dentry *dentry, struct path *path)
1da177e4 190{
7773fbc5 191 struct task_struct *task = get_proc_task(dentry->d_inode);
1da177e4 192 int result = -ENOENT;
99f89551
EB		 193
194 if (task) {
f7ad3c6b 195 result = get_task_root(task, path);
99f89551
EB		 196 put_task_struct(task);
197 }
1da177e4
LT		 198 return result;
199}
200
e268337d
LT		 201struct mm_struct *mm_for_maps(struct task_struct *task)
202{
203 return mm_access(task, PTRACE_MODE_READ);
204}
205
1da177e4
LT		 206static int proc_pid_cmdline(struct task_struct *task, char * buffer)
207{
208 int res = 0;
209 unsigned int len;
210 struct mm_struct *mm = get_task_mm(task);
211 if (!mm)
212 goto out;
213 if (!mm->arg_end)
214 goto out_mm; /* Shh! No looking before we're done */
215
216 len = mm->arg_end - mm->arg_start;
217
218 if (len > PAGE_SIZE)
219 len = PAGE_SIZE;
220
221 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
222
223 // If the nul at the end of args has been overwritten, then
224 // assume application is using setproctitle(3).
225 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
226 len = strnlen(buffer, res);
227 if (len < res) {
228 res = len;
229 } else {
230 len = mm->env_end - mm->env_start;
231 if (len > PAGE_SIZE - res)
232 len = PAGE_SIZE - res;
233 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
234 res = strnlen(buffer, res);
235 }
236 }
237out_mm:
238 mmput(mm);
239out:
240 return res;
241}
242
243static int proc_pid_auxv(struct task_struct *task, char *buffer)
244{
2fadaef4
AV		 245 struct mm_struct *mm = mm_for_maps(task);
246 int res = PTR_ERR(mm);
247 if (mm && !IS_ERR(mm)) {
1da177e4 248 unsigned int nwords = 0;
dfe6b7d9 249 do {
1da177e4 250 nwords += 2;
dfe6b7d9 251 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1da177e4
LT		 252 res = nwords * sizeof(mm->saved_auxv[0]);
253 if (res > PAGE_SIZE)
254 res = PAGE_SIZE;
255 memcpy(buffer, mm->saved_auxv, res);
256 mmput(mm);
257 }
258 return res;
259}
260
261
262#ifdef CONFIG_KALLSYMS
263/*
264 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
265 * Returns the resolved symbol. If that fails, simply return the address.
266 */
267static int proc_pid_wchan(struct task_struct *task, char *buffer)
268{
ffb45122 269 unsigned long wchan;
9281acea 270 char symname[KSYM_NAME_LEN];
1da177e4
LT		 271
272 wchan = get_wchan(task);
273
9d65cb4a 274 if (lookup_symbol_name(wchan, symname) < 0)
f83ce3e6
JE		 275 if (!ptrace_may_access(task, PTRACE_MODE_READ))
276 return 0;
277 else
278 return sprintf(buffer, "%lu", wchan);
9d65cb4a
AD		 279 else
280 return sprintf(buffer, "%s", symname);
1da177e4
LT		 281}
282#endif /* CONFIG_KALLSYMS */
283
a9712bc1
AV		 284static int lock_trace(struct task_struct *task)
285{
286 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
287 if (err)
288 return err;
289 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
290 mutex_unlock(&task->signal->cred_guard_mutex);
291 return -EPERM;
292 }
293 return 0;
294}
295
296static void unlock_trace(struct task_struct *task)
297{
298 mutex_unlock(&task->signal->cred_guard_mutex);
299}
300
2ec220e2
KC		 301#ifdef CONFIG_STACKTRACE
302
303#define MAX_STACK_TRACE_DEPTH 64
304
305static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
306 struct pid *pid, struct task_struct *task)
307{
308 struct stack_trace trace;
309 unsigned long *entries;
a9712bc1 310 int err;
2ec220e2
KC		 311 int i;
312
313 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
314 if (!entries)
315 return -ENOMEM;
316
317 trace.nr_entries = 0;
318 trace.max_entries = MAX_STACK_TRACE_DEPTH;
319 trace.entries = entries;
320 trace.skip = 0;
2ec220e2 321
a9712bc1
AV		 322 err = lock_trace(task);
323 if (!err) {
324 save_stack_trace_tsk(task, &trace);
325
326 for (i = 0; i < trace.nr_entries; i++) {
b81a618d 327 seq_printf(m, "[<%pK>] %pS\n",
a9712bc1
AV		 328 (void *)entries[i], (void *)entries[i]);
329 }
330 unlock_trace(task);
2ec220e2
KC		 331 }
332 kfree(entries);
333
a9712bc1 334 return err;
2ec220e2
KC		 335}
336#endif
337
1da177e4
LT		 338#ifdef CONFIG_SCHEDSTATS
339/*
340 * Provides /proc/PID/schedstat
341 */
342static int proc_pid_schedstat(struct task_struct *task, char *buffer)
343{
172ba844 344 return sprintf(buffer, "%llu %llu %lu\n",
826e08b0
IM		 345 (unsigned long long)task->se.sum_exec_runtime,
346 (unsigned long long)task->sched_info.run_delay,
2d72376b 347 task->sched_info.pcount);
1da177e4
LT		 348}
349#endif
350
9745512c
AV		 351#ifdef CONFIG_LATENCYTOP
352static int lstats_show_proc(struct seq_file *m, void *v)
353{
354 int i;
13d77c37
HS		 355 struct inode *inode = m->private;
356 struct task_struct *task = get_proc_task(inode);
9745512c 357
13d77c37
HS		 358 if (!task)
359 return -ESRCH;
360 seq_puts(m, "Latency Top version : v0.1\n");
9745512c 361 for (i = 0; i < 32; i++) {
34e49d4f
JP		 362 struct latency_record *lr = &task->latency_record[i];
363 if (lr->backtrace[0]) {
9745512c 364 int q;
34e49d4f
JP		 365 seq_printf(m, "%i %li %li",
366 lr->count, lr->time, lr->max);
9745512c 367 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
34e49d4f
JP		 368 unsigned long bt = lr->backtrace[q];
369 if (!bt)
9745512c 370 break;
34e49d4f 371 if (bt == ULONG_MAX)
9745512c 372 break;
34e49d4f 373 seq_printf(m, " %ps", (void *)bt);
9745512c 374 }
9d6de12f 375 seq_putc(m, '\n');
9745512c
AV		 376 }
377
378 }
13d77c37 379 put_task_struct(task);
9745512c
AV		 380 return 0;
381}
382
383static int lstats_open(struct inode *inode, struct file *file)
384{
13d77c37 385 return single_open(file, lstats_show_proc, inode);
d6643d12
HS		 386}
387
9745512c
AV		 388static ssize_t lstats_write(struct file *file, const char __user *buf,
389 size_t count, loff_t *offs)
390{
13d77c37 391 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
9745512c 392
13d77c37
HS		 393 if (!task)
394 return -ESRCH;
9745512c 395 clear_all_latency_tracing(task);
13d77c37 396 put_task_struct(task);
9745512c
AV		 397
398 return count;
399}
400
401static const struct file_operations proc_lstats_operations = {
402 .open = lstats_open,
403 .read = seq_read,
404 .write = lstats_write,
405 .llseek = seq_lseek,
13d77c37 406 .release = single_release,
9745512c
AV		 407};
408
409#endif
410
1da177e4
LT		 411static int proc_oom_score(struct task_struct *task, char *buffer)
412{
b95c35e7 413 unsigned long points = 0;
1da177e4 414
19c5d45a 415 read_lock(&tasklist_lock);
b95c35e7 416 if (pid_alive(task))
a63d83f4
DR		 417 points = oom_badness(task, NULL, NULL,
418 totalram_pages + total_swap_pages);
19c5d45a 419 read_unlock(&tasklist_lock);
1da177e4
LT		 420 return sprintf(buffer, "%lu\n", points);
421}
422
d85f50d5
NH		 423struct limit_names {
424 char *name;
425 char *unit;
426};
427
428static const struct limit_names lnames[RLIM_NLIMITS] = {
cff4edb5 429 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
d85f50d5
NH		 430 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
431 [RLIMIT_DATA] = {"Max data size", "bytes"},
432 [RLIMIT_STACK] = {"Max stack size", "bytes"},
433 [RLIMIT_CORE] = {"Max core file size", "bytes"},
434 [RLIMIT_RSS] = {"Max resident set", "bytes"},
435 [RLIMIT_NPROC] = {"Max processes", "processes"},
436 [RLIMIT_NOFILE] = {"Max open files", "files"},
437 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
438 [RLIMIT_AS] = {"Max address space", "bytes"},
439 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
440 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
441 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
442 [RLIMIT_NICE] = {"Max nice priority", NULL},
443 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
8808117c 444 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
d85f50d5
NH		 445};
446
447/* Display limits for a process */
448static int proc_pid_limits(struct task_struct *task, char *buffer)
449{
450 unsigned int i;
451 int count = 0;
452 unsigned long flags;
453 char *bufptr = buffer;
454
455 struct rlimit rlim[RLIM_NLIMITS];
456
a6bebbc8 457 if (!lock_task_sighand(task, &flags))
d85f50d5 458 return 0;
d85f50d5
NH		 459 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
460 unlock_task_sighand(task, &flags);
d85f50d5
NH		 461
462 /*
463 * print the file header
464 */
465 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
466 "Limit", "Soft Limit", "Hard Limit", "Units");
467
468 for (i = 0; i < RLIM_NLIMITS; i++) {
469 if (rlim[i].rlim_cur == RLIM_INFINITY)
470 count += sprintf(&bufptr[count], "%-25s %-20s ",
471 lnames[i].name, "unlimited");
472 else
473 count += sprintf(&bufptr[count], "%-25s %-20lu ",
474 lnames[i].name, rlim[i].rlim_cur);
475
476 if (rlim[i].rlim_max == RLIM_INFINITY)
477 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
478 else
479 count += sprintf(&bufptr[count], "%-20lu ",
480 rlim[i].rlim_max);
481
482 if (lnames[i].unit)
483 count += sprintf(&bufptr[count], "%-10s\n",
484 lnames[i].unit);
485 else
486 count += sprintf(&bufptr[count], "\n");
487 }
488
489 return count;
490}
491
ebcb6734
RM		 492#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
493static int proc_pid_syscall(struct task_struct *task, char *buffer)
494{
495 long nr;
496 unsigned long args[6], sp, pc;
a9712bc1
AV		 497 int res = lock_trace(task);
498 if (res)
499 return res;
ebcb6734
RM		 500
501 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
a9712bc1
AV		 502 res = sprintf(buffer, "running\n");
503 else if (nr < 0)
504 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
505 else
506 res = sprintf(buffer,
ebcb6734
RM		 507 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
508 nr,
509 args[0], args[1], args[2], args[3], args[4], args[5],
510 sp, pc);
a9712bc1
AV		 511 unlock_trace(task);
512 return res;
ebcb6734
RM		 513}
514#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
515
1da177e4
LT		 516/************************************************************************/
517/* Here the fs part begins */
518/************************************************************************/
519
520/* permission checks */
778c1144 521static int proc_fd_access_allowed(struct inode *inode)
1da177e4 522{
778c1144
EB		 523 struct task_struct *task;
524 int allowed = 0;
df26c40e
EB		 525 /* Allow access to a task's file descriptors if it is us or we
526 * may use ptrace attach to the process and find out that
527 * information.
778c1144
EB		 528 */
529 task = get_proc_task(inode);
df26c40e 530 if (task) {
006ebb40 531 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
778c1144 532 put_task_struct(task);
df26c40e 533 }
778c1144 534 return allowed;
1da177e4
LT		 535}
536
6b4e306a 537int proc_setattr(struct dentry *dentry, struct iattr *attr)
6d76fa58
LT		 538{
539 int error;
540 struct inode *inode = dentry->d_inode;
541
542 if (attr->ia_valid & ATTR_MODE)
543 return -EPERM;
544
545 error = inode_change_ok(inode, attr);
1025774c
CH		 546 if (error)
547 return error;
548
549 if ((attr->ia_valid & ATTR_SIZE) &&
550 attr->ia_size != i_size_read(inode)) {
551 error = vmtruncate(inode, attr->ia_size);
552 if (error)
553 return error;
554 }
555
556 setattr_copy(inode, attr);
557 mark_inode_dirty(inode);
558 return 0;
6d76fa58
LT		 559}
560
0499680a
VK		 561/*
562 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
563 * or euid/egid (for hide_pid_min=2)?
564 */
565static bool has_pid_permissions(struct pid_namespace *pid,
566 struct task_struct *task,
567 int hide_pid_min)
568{
569 if (pid->hide_pid < hide_pid_min)
570 return true;
571 if (in_group_p(pid->pid_gid))
572 return true;
573 return ptrace_may_access(task, PTRACE_MODE_READ);
574}
575
576
577static int proc_pid_permission(struct inode *inode, int mask)
578{
579 struct pid_namespace *pid = inode->i_sb->s_fs_info;
580 struct task_struct *task;
581 bool has_perms;
582
583 task = get_proc_task(inode);
a2ef990a
XF		 584 if (!task)
585 return -ESRCH;
0499680a
VK		 586 has_perms = has_pid_permissions(pid, task, 1);
587 put_task_struct(task);
588
589 if (!has_perms) {
590 if (pid->hide_pid == 2) {
591 /*
592 * Let's make getdents(), stat(), and open()
593 * consistent with each other. If a process
594 * may not stat() a file, it shouldn't be seen
595 * in procfs at all.
596 */
597 return -ENOENT;
598 }
599
600 return -EPERM;
601 }
602 return generic_permission(inode, mask);
603}
604
605
606
c5ef1c42 607static const struct inode_operations proc_def_inode_operations = {
6d76fa58
LT		 608 .setattr = proc_setattr,
609};
610
1da177e4
LT		 611#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
612
613static ssize_t proc_info_read(struct file * file, char __user * buf,
614 size_t count, loff_t *ppos)
615{
2fddfeef 616 struct inode * inode = file->f_path.dentry->d_inode;
1da177e4
LT		 617 unsigned long page;
618 ssize_t length;
99f89551
EB		 619 struct task_struct *task = get_proc_task(inode);
620
621 length = -ESRCH;
622 if (!task)
623 goto out_no_task;
1da177e4
LT		 624
625 if (count > PROC_BLOCK_SIZE)
626 count = PROC_BLOCK_SIZE;
99f89551
EB		 627
628 length = -ENOMEM;
e12ba74d 629 if (!(page = __get_free_page(GFP_TEMPORARY)))
99f89551 630 goto out;
1da177e4
LT		 631
632 length = PROC_I(inode)->op.proc_read(task, (char*)page);
633
634 if (length >= 0)
635 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
636 free_page(page);
99f89551
EB		 637out:
638 put_task_struct(task);
639out_no_task:
1da177e4
LT		 640 return length;
641}
642
00977a59 643static const struct file_operations proc_info_file_operations = {
1da177e4 644 .read = proc_info_read,
87df8424 645 .llseek = generic_file_llseek,
1da177e4
LT		 646};
647
be614086
EB		 648static int proc_single_show(struct seq_file *m, void *v)
649{
650 struct inode *inode = m->private;
651 struct pid_namespace *ns;
652 struct pid *pid;
653 struct task_struct *task;
654 int ret;
655
656 ns = inode->i_sb->s_fs_info;
657 pid = proc_pid(inode);
658 task = get_pid_task(pid, PIDTYPE_PID);
659 if (!task)
660 return -ESRCH;
661
662 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
663
664 put_task_struct(task);
665 return ret;
666}
667
668static int proc_single_open(struct inode *inode, struct file *filp)
669{
c6a34058 670 return single_open(filp, proc_single_show, inode);
be614086
EB		 671}
672
673static const struct file_operations proc_single_file_operations = {
674 .open = proc_single_open,
675 .read = seq_read,
676 .llseek = seq_lseek,
677 .release = single_release,
678};
679
1da177e4
LT		 680static int mem_open(struct inode* inode, struct file* file)
681{
e268337d
LT		 682 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
683 struct mm_struct *mm;
684
685 if (!task)
686 return -ESRCH;
687
688 mm = mm_access(task, PTRACE_MODE_ATTACH);
689 put_task_struct(task);
690
691 if (IS_ERR(mm))
692 return PTR_ERR(mm);
693
6d08f2c7
ON		 694 if (mm) {
695 /* ensure this mm_struct can't be freed */
696 atomic_inc(&mm->mm_count);
697 /* but do not pin its memory */
698 mmput(mm);
699 }
700
4a3956c7
KH		 701 /* OK to pass negative loff_t, we can catch out-of-range */
702 file->f_mode |= FMODE_UNSIGNED_OFFSET;
e268337d
LT		 703 file->private_data = mm;
704
1da177e4
LT		 705 return 0;
706}
707
572d34b9
ON		 708static ssize_t mem_rw(struct file *file, char __user *buf,
709 size_t count, loff_t *ppos, int write)
1da177e4 710{
e268337d 711 struct mm_struct *mm = file->private_data;
572d34b9
ON		 712 unsigned long addr = *ppos;
713 ssize_t copied;
1da177e4 714 char *page;
1da177e4 715
e268337d
LT		 716 if (!mm)
717 return 0;
99f89551 718
30cd8903
KM		 719 page = (char *)__get_free_page(GFP_TEMPORARY);
720 if (!page)
e268337d 721 return -ENOMEM;
1da177e4 722
f7ca54f4 723 copied = 0;
6d08f2c7
ON		 724 if (!atomic_inc_not_zero(&mm->mm_users))
725 goto free;
726
1da177e4 727 while (count > 0) {
572d34b9 728 int this_len = min_t(int, count, PAGE_SIZE);
1da177e4 729
572d34b9 730 if (write && copy_from_user(page, buf, this_len)) {
1da177e4
LT		 731 copied = -EFAULT;
732 break;
733 }
572d34b9
ON		 734
735 this_len = access_remote_vm(mm, addr, page, this_len, write);
736 if (!this_len) {
1da177e4
LT		 737 if (!copied)
738 copied = -EIO;
739 break;
740 }
572d34b9
ON		 741
742 if (!write && copy_to_user(buf, page, this_len)) {
743 copied = -EFAULT;
744 break;
745 }
746
747 buf += this_len;
748 addr += this_len;
749 copied += this_len;
750 count -= this_len;
1da177e4 751 }
572d34b9 752 *ppos = addr;
30cd8903 753
6d08f2c7
ON		 754 mmput(mm);
755free:
30cd8903 756 free_page((unsigned long) page);
1da177e4
LT		 757 return copied;
758}
1da177e4 759
572d34b9
ON		 760static ssize_t mem_read(struct file *file, char __user *buf,
761 size_t count, loff_t *ppos)
762{
763 return mem_rw(file, buf, count, ppos, 0);
764}
765
766static ssize_t mem_write(struct file *file, const char __user *buf,
767 size_t count, loff_t *ppos)
768{
769 return mem_rw(file, (char __user*)buf, count, ppos, 1);
770}
771
85863e47 772loff_t mem_lseek(struct file *file, loff_t offset, int orig)
1da177e4
LT		 773{
774 switch (orig) {
775 case 0:
776 file->f_pos = offset;
777 break;
778 case 1:
779 file->f_pos += offset;
780 break;
781 default:
782 return -EINVAL;
783 }
784 force_successful_syscall_return();
785 return file->f_pos;
786}
787
e268337d
LT		 788static int mem_release(struct inode *inode, struct file *file)
789{
790 struct mm_struct *mm = file->private_data;
71879d3c 791 if (mm)
6d08f2c7 792 mmdrop(mm);
e268337d
LT		 793 return 0;
794}
795
00977a59 796static const struct file_operations proc_mem_operations = {
1da177e4
LT		 797 .llseek = mem_lseek,
798 .read = mem_read,
799 .write = mem_write,
800 .open = mem_open,
e268337d 801 .release = mem_release,
1da177e4
LT		 802};
803
315e28c8
JP		 804static ssize_t environ_read(struct file *file, char __user *buf,
805 size_t count, loff_t *ppos)
806{
807 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
808 char *page;
809 unsigned long src = *ppos;
810 int ret = -ESRCH;
811 struct mm_struct *mm;
812
813 if (!task)
814 goto out_no_task;
815
315e28c8
JP		 816 ret = -ENOMEM;
817 page = (char *)__get_free_page(GFP_TEMPORARY);
818 if (!page)
819 goto out;
820
315e28c8 821
d6f64b89
AV		 822 mm = mm_for_maps(task);
823 ret = PTR_ERR(mm);
824 if (!mm || IS_ERR(mm))
315e28c8
JP		 825 goto out_free;
826
d6f64b89 827 ret = 0;
315e28c8
JP		 828 while (count > 0) {
829 int this_len, retval, max_len;
830
831 this_len = mm->env_end - (mm->env_start + src);
832
833 if (this_len <= 0)
834 break;
835
836 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
837 this_len = (this_len > max_len) ? max_len : this_len;
838
839 retval = access_process_vm(task, (mm->env_start + src),
840 page, this_len, 0);
841
842 if (retval <= 0) {
843 ret = retval;
844 break;
845 }
846
847 if (copy_to_user(buf, page, retval)) {
848 ret = -EFAULT;
849 break;
850 }
851
852 ret += retval;
853 src += retval;
854 buf += retval;
855 count -= retval;
856 }
857 *ppos = src;
858
859 mmput(mm);
860out_free:
861 free_page((unsigned long) page);
862out:
863 put_task_struct(task);
864out_no_task:
865 return ret;
866}
867
868static const struct file_operations proc_environ_operations = {
869 .read = environ_read,
87df8424 870 .llseek = generic_file_llseek,
315e28c8
JP		 871};
872
1da177e4
LT		 873static ssize_t oom_adjust_read(struct file *file, char __user *buf,
874 size_t count, loff_t *ppos)
875{
2fddfeef 876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
8578cea7 877 char buffer[PROC_NUMBUF];
1da177e4 878 size_t len;
28b83c51
KM		 879 int oom_adjust = OOM_DISABLE;
880 unsigned long flags;
1da177e4 881
99f89551
EB		 882 if (!task)
883 return -ESRCH;
28b83c51
KM		 884
885 if (lock_task_sighand(task, &flags)) {
886 oom_adjust = task->signal->oom_adj;
887 unlock_task_sighand(task, &flags);
888 }
889
99f89551
EB		 890 put_task_struct(task);
891
8578cea7 892 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
0c28f287
AM		 893
894 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1da177e4
LT		 895}
896
897static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
898 size_t count, loff_t *ppos)
899{
99f89551 900 struct task_struct *task;
5d863b89 901 char buffer[PROC_NUMBUF];
0a8cb8e3 902 int oom_adjust;
28b83c51 903 unsigned long flags;
5d863b89 904 int err;
1da177e4 905
8578cea7
EB		 906 memset(buffer, 0, sizeof(buffer));
907 if (count > sizeof(buffer) - 1)
908 count = sizeof(buffer) - 1;
723548bf
DR		 909 if (copy_from_user(buffer, buf, count)) {
910 err = -EFAULT;
911 goto out;
912 }
5d863b89 913
0a8cb8e3 914 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
5d863b89 915 if (err)
723548bf 916 goto out;
8ac773b4 917 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
723548bf
DR		 918 oom_adjust != OOM_DISABLE) {
919 err = -EINVAL;
920 goto out;
921 }
5d863b89 922
2fddfeef 923 task = get_proc_task(file->f_path.dentry->d_inode);
723548bf
DR		 924 if (!task) {
925 err = -ESRCH;
926 goto out;
927 }
d19d5476
DR		 928
929 task_lock(task);
930 if (!task->mm) {
931 err = -EINVAL;
932 goto err_task_lock;
933 }
934
28b83c51 935 if (!lock_task_sighand(task, &flags)) {
723548bf 936 err = -ESRCH;
d19d5476 937 goto err_task_lock;
28b83c51
KM		 938 }
939
940 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
723548bf
DR		 941 err = -EACCES;
942 goto err_sighand;
8fb4fc68 943 }
28b83c51 944
51b1bd2a
DR		 945 /*
946 * Warn that /proc/pid/oom_adj is deprecated, see
947 * Documentation/feature-removal-schedule.txt.
948 */
c2142704 949 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
be8f684d
DR		 950 current->comm, task_pid_nr(current), task_pid_nr(task),
951 task_pid_nr(task));
28b83c51 952 task->signal->oom_adj = oom_adjust;
a63d83f4
DR		 953 /*
954 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
955 * value is always attainable.
956 */
957 if (task->signal->oom_adj == OOM_ADJUST_MAX)
958 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
959 else
960 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
961 -OOM_DISABLE;
43d2b113 962 trace_oom_score_adj_update(task);
723548bf 963err_sighand:
28b83c51 964 unlock_task_sighand(task, &flags);
d19d5476
DR		 965err_task_lock:
966 task_unlock(task);
99f89551 967 put_task_struct(task);
723548bf
DR		 968out:
969 return err < 0 ? err : count;
1da177e4
LT		 970}
971
00977a59 972static const struct file_operations proc_oom_adjust_operations = {
1da177e4
LT		 973 .read = oom_adjust_read,
974 .write = oom_adjust_write,
87df8424 975 .llseek = generic_file_llseek,
1da177e4
LT		 976};
977
a63d83f4
DR		 978static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
979 size_t count, loff_t *ppos)
980{
981 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
982 char buffer[PROC_NUMBUF];
983 int oom_score_adj = OOM_SCORE_ADJ_MIN;
984 unsigned long flags;
985 size_t len;
986
987 if (!task)
988 return -ESRCH;
989 if (lock_task_sighand(task, &flags)) {
990 oom_score_adj = task->signal->oom_score_adj;
991 unlock_task_sighand(task, &flags);
992 }
993 put_task_struct(task);
994 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
995 return simple_read_from_buffer(buf, count, ppos, buffer, len);
996}
997
998static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
999 size_t count, loff_t *ppos)
1000{
1001 struct task_struct *task;
1002 char buffer[PROC_NUMBUF];
1003 unsigned long flags;
0a8cb8e3 1004 int oom_score_adj;
a63d83f4
DR		 1005 int err;
1006
1007 memset(buffer, 0, sizeof(buffer));
1008 if (count > sizeof(buffer) - 1)
1009 count = sizeof(buffer) - 1;
723548bf
DR		 1010 if (copy_from_user(buffer, buf, count)) {
1011 err = -EFAULT;
1012 goto out;
1013 }
a63d83f4 1014
0a8cb8e3 1015 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
a63d83f4 1016 if (err)
723548bf 1017 goto out;
a63d83f4 1018 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
723548bf
DR		 1019 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1020 err = -EINVAL;
1021 goto out;
1022 }
a63d83f4
DR		 1023
1024 task = get_proc_task(file->f_path.dentry->d_inode);
723548bf
DR		 1025 if (!task) {
1026 err = -ESRCH;
1027 goto out;
1028 }
d19d5476
DR		 1029
1030 task_lock(task);
1031 if (!task->mm) {
1032 err = -EINVAL;
1033 goto err_task_lock;
1034 }
1035
a63d83f4 1036 if (!lock_task_sighand(task, &flags)) {
723548bf 1037 err = -ESRCH;
d19d5476 1038 goto err_task_lock;
a63d83f4 1039 }
d19d5476 1040
dabb16f6 1041 if (oom_score_adj < task->signal->oom_score_adj_min &&
a63d83f4 1042 !capable(CAP_SYS_RESOURCE)) {
723548bf
DR		 1043 err = -EACCES;
1044 goto err_sighand;
a63d83f4
DR		 1045 }
1046
1047 task->signal->oom_score_adj = oom_score_adj;
dabb16f6
MSB		 1048 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1049 task->signal->oom_score_adj_min = oom_score_adj;
43d2b113 1050 trace_oom_score_adj_update(task);
a63d83f4
DR		 1051 /*
1052 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1053 * always attainable.
1054 */
1055 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1056 task->signal->oom_adj = OOM_DISABLE;
1057 else
1058 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1059 OOM_SCORE_ADJ_MAX;
723548bf 1060err_sighand:
a63d83f4 1061 unlock_task_sighand(task, &flags);
d19d5476
DR		 1062err_task_lock:
1063 task_unlock(task);
a63d83f4 1064 put_task_struct(task);
723548bf
DR		 1065out:
1066 return err < 0 ? err : count;
a63d83f4
DR		 1067}
1068
1069static const struct file_operations proc_oom_score_adj_operations = {
1070 .read = oom_score_adj_read,
1071 .write = oom_score_adj_write,
6038f373 1072 .llseek = default_llseek,
a63d83f4
DR		 1073};
1074
1da177e4
LT		 1075#ifdef CONFIG_AUDITSYSCALL
1076#define TMPBUFLEN 21
1077static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1078 size_t count, loff_t *ppos)
1079{
2fddfeef 1080 struct inode * inode = file->f_path.dentry->d_inode;
99f89551 1081 struct task_struct *task = get_proc_task(inode);
1da177e4
LT		 1082 ssize_t length;
1083 char tmpbuf[TMPBUFLEN];
1084
99f89551
EB		 1085 if (!task)
1086 return -ESRCH;
1da177e4 1087 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
0c11b942 1088 audit_get_loginuid(task));
99f89551 1089 put_task_struct(task);
1da177e4
LT		 1090 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1091}
1092
1093static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1094 size_t count, loff_t *ppos)
1095{
2fddfeef 1096 struct inode * inode = file->f_path.dentry->d_inode;
1da177e4
LT		 1097 char *page, *tmp;
1098 ssize_t length;
1da177e4
LT		 1099 uid_t loginuid;
1100
7dc52157
PM		 1101 rcu_read_lock();
1102 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1103 rcu_read_unlock();
1da177e4 1104 return -EPERM;
7dc52157
PM		 1105 }
1106 rcu_read_unlock();
1da177e4 1107
e0182909
AV		 1108 if (count >= PAGE_SIZE)
1109 count = PAGE_SIZE - 1;
1da177e4
LT		 1110
1111 if (*ppos != 0) {
1112 /* No partial writes. */
1113 return -EINVAL;
1114 }
e12ba74d 1115 page = (char*)__get_free_page(GFP_TEMPORARY);
1da177e4
LT		 1116 if (!page)
1117 return -ENOMEM;
1118 length = -EFAULT;
1119 if (copy_from_user(page, buf, count))
1120 goto out_free_page;
1121
e0182909 1122 page[count] = '\0';
1da177e4
LT		 1123 loginuid = simple_strtoul(page, &tmp, 10);
1124 if (tmp == page) {
1125 length = -EINVAL;
1126 goto out_free_page;
1127
1128 }
0a300be6 1129 length = audit_set_loginuid(loginuid);
1da177e4
LT		 1130 if (likely(length == 0))
1131 length = count;
1132
1133out_free_page:
1134 free_page((unsigned long) page);
1135 return length;
1136}
1137
00977a59 1138static const struct file_operations proc_loginuid_operations = {
1da177e4
LT		 1139 .read = proc_loginuid_read,
1140 .write = proc_loginuid_write,
87df8424 1141 .llseek = generic_file_llseek,
1da177e4 1142};
1e0bd755
EP		 1143
1144static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1145 size_t count, loff_t *ppos)
1146{
1147 struct inode * inode = file->f_path.dentry->d_inode;
1148 struct task_struct *task = get_proc_task(inode);
1149 ssize_t length;
1150 char tmpbuf[TMPBUFLEN];
1151
1152 if (!task)
1153 return -ESRCH;
1154 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1155 audit_get_sessionid(task));
1156 put_task_struct(task);
1157 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1158}
1159
1160static const struct file_operations proc_sessionid_operations = {
1161 .read = proc_sessionid_read,
87df8424 1162 .llseek = generic_file_llseek,
1e0bd755 1163};
1da177e4
LT		 1164#endif
1165
f4f154fd
AM		 1166#ifdef CONFIG_FAULT_INJECTION
1167static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1168 size_t count, loff_t *ppos)
1169{
1170 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1171 char buffer[PROC_NUMBUF];
1172 size_t len;
1173 int make_it_fail;
f4f154fd
AM		 1174
1175 if (!task)
1176 return -ESRCH;
1177 make_it_fail = task->make_it_fail;
1178 put_task_struct(task);
1179
1180 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
0c28f287
AM		 1181
1182 return simple_read_from_buffer(buf, count, ppos, buffer, len);
f4f154fd
AM		 1183}
1184
1185static ssize_t proc_fault_inject_write(struct file * file,
1186 const char __user * buf, size_t count, loff_t *ppos)
1187{
1188 struct task_struct *task;
1189 char buffer[PROC_NUMBUF], *end;
1190 int make_it_fail;
1191
1192 if (!capable(CAP_SYS_RESOURCE))
1193 return -EPERM;
1194 memset(buffer, 0, sizeof(buffer));
1195 if (count > sizeof(buffer) - 1)
1196 count = sizeof(buffer) - 1;
1197 if (copy_from_user(buffer, buf, count))
1198 return -EFAULT;
cba8aafe
VL		 1199 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1200 if (*end)
1201 return -EINVAL;
f4f154fd
AM		 1202 task = get_proc_task(file->f_dentry->d_inode);
1203 if (!task)
1204 return -ESRCH;
1205 task->make_it_fail = make_it_fail;
1206 put_task_struct(task);
cba8aafe
VL		 1207
1208 return count;
f4f154fd
AM		 1209}
1210
00977a59 1211static const struct file_operations proc_fault_inject_operations = {
f4f154fd
AM		 1212 .read = proc_fault_inject_read,
1213 .write = proc_fault_inject_write,
87df8424 1214 .llseek = generic_file_llseek,
f4f154fd
AM		 1215};
1216#endif
1217
9745512c 1218
43ae34cb
IM		 1219#ifdef CONFIG_SCHED_DEBUG
1220/*
1221 * Print out various scheduling related per-task fields:
1222 */
1223static int sched_show(struct seq_file *m, void *v)
1224{
1225 struct inode *inode = m->private;
1226 struct task_struct *p;
1227
43ae34cb
IM		 1228 p = get_proc_task(inode);
1229 if (!p)
1230 return -ESRCH;
1231 proc_sched_show_task(p, m);
1232
1233 put_task_struct(p);
1234
1235 return 0;
1236}
1237
1238static ssize_t
1239sched_write(struct file *file, const char __user *buf,
1240 size_t count, loff_t *offset)
1241{
1242 struct inode *inode = file->f_path.dentry->d_inode;
1243 struct task_struct *p;
1244
43ae34cb
IM		 1245 p = get_proc_task(inode);
1246 if (!p)
1247 return -ESRCH;
1248 proc_sched_set_task(p);
1249
1250 put_task_struct(p);
1251
1252 return count;
1253}
1254
1255static int sched_open(struct inode *inode, struct file *filp)
1256{
c6a34058 1257 return single_open(filp, sched_show, inode);
43ae34cb
IM		 1258}
1259
1260static const struct file_operations proc_pid_sched_operations = {
1261 .open = sched_open,
1262 .read = seq_read,
1263 .write = sched_write,
1264 .llseek = seq_lseek,
5ea473a1 1265 .release = single_release,
43ae34cb
IM		 1266};
1267
1268#endif
1269
5091faa4
MG		 1270#ifdef CONFIG_SCHED_AUTOGROUP
1271/*
1272 * Print out autogroup related information:
1273 */
1274static int sched_autogroup_show(struct seq_file *m, void *v)
1275{
1276 struct inode *inode = m->private;
1277 struct task_struct *p;
1278
1279 p = get_proc_task(inode);
1280 if (!p)
1281 return -ESRCH;
1282 proc_sched_autogroup_show_task(p, m);
1283
1284 put_task_struct(p);
1285
1286 return 0;
1287}
1288
1289static ssize_t
1290sched_autogroup_write(struct file *file, const char __user *buf,
1291 size_t count, loff_t *offset)
1292{
1293 struct inode *inode = file->f_path.dentry->d_inode;
1294 struct task_struct *p;
1295 char buffer[PROC_NUMBUF];
0a8cb8e3 1296 int nice;
5091faa4
MG		 1297 int err;
1298
1299 memset(buffer, 0, sizeof(buffer));
1300 if (count > sizeof(buffer) - 1)
1301 count = sizeof(buffer) - 1;
1302 if (copy_from_user(buffer, buf, count))
1303 return -EFAULT;
1304
0a8cb8e3
AD		 1305 err = kstrtoint(strstrip(buffer), 0, &nice);
1306 if (err < 0)
1307 return err;
5091faa4
MG		 1308
1309 p = get_proc_task(inode);
1310 if (!p)
1311 return -ESRCH;
1312
2e5b5b3a 1313 err = proc_sched_autogroup_set_nice(p, nice);
5091faa4
MG		 1314 if (err)
1315 count = err;
1316
1317 put_task_struct(p);
1318
1319 return count;
1320}
1321
1322static int sched_autogroup_open(struct inode *inode, struct file *filp)
1323{
1324 int ret;
1325
1326 ret = single_open(filp, sched_autogroup_show, NULL);
1327 if (!ret) {
1328 struct seq_file *m = filp->private_data;
1329
1330 m->private = inode;
1331 }
1332 return ret;
1333}
1334
1335static const struct file_operations proc_pid_sched_autogroup_operations = {
1336 .open = sched_autogroup_open,
1337 .read = seq_read,
1338 .write = sched_autogroup_write,
1339 .llseek = seq_lseek,
1340 .release = single_release,
1341};
1342
1343#endif /* CONFIG_SCHED_AUTOGROUP */
1344
4614a696 1345static ssize_t comm_write(struct file *file, const char __user *buf,
1346 size_t count, loff_t *offset)
1347{
1348 struct inode *inode = file->f_path.dentry->d_inode;
1349 struct task_struct *p;
1350 char buffer[TASK_COMM_LEN];
1351
1352 memset(buffer, 0, sizeof(buffer));
1353 if (count > sizeof(buffer) - 1)
1354 count = sizeof(buffer) - 1;
1355 if (copy_from_user(buffer, buf, count))
1356 return -EFAULT;
1357
1358 p = get_proc_task(inode);
1359 if (!p)
1360 return -ESRCH;
1361
1362 if (same_thread_group(current, p))
1363 set_task_comm(p, buffer);
1364 else
1365 count = -EINVAL;
1366
1367 put_task_struct(p);
1368
1369 return count;
1370}
1371
1372static int comm_show(struct seq_file *m, void *v)
1373{
1374 struct inode *inode = m->private;
1375 struct task_struct *p;
1376
1377 p = get_proc_task(inode);
1378 if (!p)
1379 return -ESRCH;
1380
1381 task_lock(p);
1382 seq_printf(m, "%s\n", p->comm);
1383 task_unlock(p);
1384
1385 put_task_struct(p);
1386
1387 return 0;
1388}
1389
1390static int comm_open(struct inode *inode, struct file *filp)
1391{
c6a34058 1392 return single_open(filp, comm_show, inode);
4614a696 1393}
1394
1395static const struct file_operations proc_pid_set_comm_operations = {
1396 .open = comm_open,
1397 .read = seq_read,
1398 .write = comm_write,
1399 .llseek = seq_lseek,
1400 .release = single_release,
1401};
1402
7773fbc5 1403static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
925d1c40
MH		 1404{
1405 struct task_struct *task;
1406 struct mm_struct *mm;
1407 struct file *exe_file;
1408
7773fbc5 1409 task = get_proc_task(dentry->d_inode);
925d1c40
MH		 1410 if (!task)
1411 return -ENOENT;
1412 mm = get_task_mm(task);
1413 put_task_struct(task);
1414 if (!mm)
1415 return -ENOENT;
1416 exe_file = get_mm_exe_file(mm);
1417 mmput(mm);
1418 if (exe_file) {
1419 *exe_path = exe_file->f_path;
1420 path_get(&exe_file->f_path);
1421 fput(exe_file);
1422 return 0;
1423 } else
1424 return -ENOENT;
1425}
1426
008b150a 1427static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1da177e4
LT		 1428{
1429 struct inode *inode = dentry->d_inode;
1430 int error = -EACCES;
1431
1432 /* We don't need a base pointer in the /proc filesystem */
1d957f9b 1433 path_put(&nd->path);
1da177e4 1434
778c1144
EB		 1435 /* Are we allowed to snoop on the tasks file descriptors? */
1436 if (!proc_fd_access_allowed(inode))
1da177e4 1437 goto out;
1da177e4 1438
7773fbc5 1439 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
1da177e4 1440out:
008b150a 1441 return ERR_PTR(error);
1da177e4
LT		 1442}
1443
3dcd25f3 1444static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1da177e4 1445{
e12ba74d 1446 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
3dcd25f3 1447 char *pathname;
1da177e4
LT		 1448 int len;
1449
1450 if (!tmp)
1451 return -ENOMEM;
0c28f287 1452
7b2a69ba 1453 pathname = d_path(path, tmp, PAGE_SIZE);
3dcd25f3
JB		 1454 len = PTR_ERR(pathname);
1455 if (IS_ERR(pathname))
1da177e4 1456 goto out;
3dcd25f3 1457 len = tmp + PAGE_SIZE - 1 - pathname;
1da177e4
LT		 1458
1459 if (len > buflen)
1460 len = buflen;
3dcd25f3 1461 if (copy_to_user(buffer, pathname, len))
1da177e4
LT		 1462 len = -EFAULT;
1463 out:
1464 free_page((unsigned long)tmp);
1465 return len;
1466}
1467
1468static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1469{
1470 int error = -EACCES;
1471 struct inode *inode = dentry->d_inode;
3dcd25f3 1472 struct path path;
1da177e4 1473
778c1144
EB		 1474 /* Are we allowed to snoop on the tasks file descriptors? */
1475 if (!proc_fd_access_allowed(inode))
1da177e4 1476 goto out;
1da177e4 1477
7773fbc5 1478 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1da177e4
LT		 1479 if (error)
1480 goto out;
1481
3dcd25f3
JB		 1482 error = do_proc_readlink(&path, buffer, buflen);
1483 path_put(&path);
1da177e4 1484out:
1da177e4
LT		 1485 return error;
1486}
1487
c5ef1c42 1488static const struct inode_operations proc_pid_link_inode_operations = {
1da177e4 1489 .readlink = proc_pid_readlink,
6d76fa58
LT		 1490 .follow_link = proc_pid_follow_link,
1491 .setattr = proc_setattr,
1da177e4
LT		 1492};
1493
28a6d671
EB		 1494
1495/* building an inode */
1496
1497static int task_dumpable(struct task_struct *task)
1da177e4 1498{
28a6d671
EB		 1499 int dumpable = 0;
1500 struct mm_struct *mm;
1da177e4 1501
28a6d671
EB		 1502 task_lock(task);
1503 mm = task->mm;
1504 if (mm)
6c5d5238 1505 dumpable = get_dumpable(mm);
28a6d671
EB		 1506 task_unlock(task);
1507 if(dumpable == 1)
1508 return 1;
1509 return 0;
1510}
1da177e4 1511
6b4e306a 1512struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
28a6d671
EB		 1513{
1514 struct inode * inode;
1515 struct proc_inode *ei;
c69e8d9c 1516 const struct cred *cred;
1da177e4 1517
28a6d671 1518 /* We need a new inode */
1da177e4 1519
28a6d671
EB		 1520 inode = new_inode(sb);
1521 if (!inode)
1522 goto out;
1523
1524 /* Common stuff */
1525 ei = PROC_I(inode);
85fe4025 1526 inode->i_ino = get_next_ino();
28a6d671 1527 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
28a6d671
EB		 1528 inode->i_op = &proc_def_inode_operations;
1529
1530 /*
1531 * grab the reference to task.
1532 */
1a657f78 1533 ei->pid = get_task_pid(task, PIDTYPE_PID);
28a6d671
EB		 1534 if (!ei->pid)
1535 goto out_unlock;
1536
28a6d671 1537 if (task_dumpable(task)) {
c69e8d9c
DH		 1538 rcu_read_lock();
1539 cred = __task_cred(task);
1540 inode->i_uid = cred->euid;
1541 inode->i_gid = cred->egid;
1542 rcu_read_unlock();
1da177e4 1543 }
28a6d671
EB		 1544 security_task_to_inode(task, inode);
1545
1da177e4 1546out:
28a6d671
EB		 1547 return inode;
1548
1549out_unlock:
1550 iput(inode);
1551 return NULL;
1da177e4
LT		 1552}
1553
6b4e306a 1554int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1da177e4 1555{
1da177e4 1556 struct inode *inode = dentry->d_inode;
28a6d671 1557 struct task_struct *task;
c69e8d9c 1558 const struct cred *cred;
0499680a 1559 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
c69e8d9c 1560
28a6d671 1561 generic_fillattr(inode, stat);
1da177e4 1562
28a6d671
EB		 1563 rcu_read_lock();
1564 stat->uid = 0;
1565 stat->gid = 0;
1566 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1567 if (task) {
0499680a
VK		 1568 if (!has_pid_permissions(pid, task, 2)) {
1569 rcu_read_unlock();
1570 /*
1571 * This doesn't prevent learning whether PID exists,
1572 * it only makes getattr() consistent with readdir().
1573 */
1574 return -ENOENT;
1575 }
28a6d671
EB		 1576 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1577 task_dumpable(task)) {
c69e8d9c
DH		 1578 cred = __task_cred(task);
1579 stat->uid = cred->euid;
1580 stat->gid = cred->egid;
1da177e4
LT		 1581 }
1582 }
28a6d671 1583 rcu_read_unlock();
d6e71144 1584 return 0;
1da177e4
LT		 1585}
1586
1da177e4
LT		 1587/* dentry stuff */
1588
1589/*
1590 * Exceptional case: normally we are not allowed to unhash a busy
1591 * directory. In this case, however, we can do it - no aliasing problems
1592 * due to the way we treat inodes.
1593 *
1594 * Rewrite the inode's ownerships here because the owning task may have
1595 * performed a setuid(), etc.
99f89551
EB		 1596 *
1597 * Before the /proc/pid/status file was created the only way to read
1598 * the effective uid of a /process was to stat /proc/pid. Reading
1599 * /proc/pid/status is slow enough that procps and other packages
1600 * kept stating /proc/pid. To keep the rules in /proc simple I have
1601 * made this apply to all per process world readable and executable
1602 * directories.
1da177e4 1603 */
6b4e306a 1604int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1da177e4 1605{
34286d66
NP		 1606 struct inode *inode;
1607 struct task_struct *task;
c69e8d9c
DH		 1608 const struct cred *cred;
1609
34286d66
NP		 1610 if (nd && nd->flags & LOOKUP_RCU)
1611 return -ECHILD;
1612
1613 inode = dentry->d_inode;
1614 task = get_proc_task(inode);
1615
99f89551
EB		 1616 if (task) {
1617 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1618 task_dumpable(task)) {
c69e8d9c
DH		 1619 rcu_read_lock();
1620 cred = __task_cred(task);
1621 inode->i_uid = cred->euid;
1622 inode->i_gid = cred->egid;
1623 rcu_read_unlock();
1da177e4
LT		 1624 } else {
1625 inode->i_uid = 0;
1626 inode->i_gid = 0;
1627 }
9ee8ab9f 1628 inode->i_mode &= ~(S_ISUID | S_ISGID);
1da177e4 1629 security_task_to_inode(task, inode);
99f89551 1630 put_task_struct(task);
1da177e4
LT		 1631 return 1;
1632 }
1633 d_drop(dentry);
1634 return 0;
1635}
1636
fe15ce44 1637static int pid_delete_dentry(const struct dentry * dentry)
99f89551 1638{
28a6d671
EB		 1639 /* Is the task we represent dead?
1640 * If so, then don't put the dentry on the lru list,
1641 * kill it immediately.
1642 */
1643 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1644}
1645
6b4e306a 1646const struct dentry_operations pid_dentry_operations =
28a6d671
EB		 1647{
1648 .d_revalidate = pid_revalidate,
1649 .d_delete = pid_delete_dentry,
1650};
1651
1652/* Lookups */
1653
1c0d04c9
EB		 1654/*
1655 * Fill a directory entry.
1656 *
1657 * If possible create the dcache entry and derive our inode number and
1658 * file type from dcache entry.
1659 *
1660 * Since all of the proc inode numbers are dynamically generated, the inode
1661 * numbers do not exist until the inode is cache. This means creating the
1662 * the dcache entry in readdir is necessary to keep the inode numbers
1663 * reported by readdir in sync with the inode numbers reported
1664 * by stat.
1665 */
6b4e306a
EB		 1666int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1667 const char *name, int len,
c5141e6d 1668 instantiate_t instantiate, struct task_struct *task, const void *ptr)
61a28784 1669{
2fddfeef 1670 struct dentry *child, *dir = filp->f_path.dentry;
61a28784
EB		 1671 struct inode *inode;
1672 struct qstr qname;
1673 ino_t ino = 0;
1674 unsigned type = DT_UNKNOWN;
1675
1676 qname.name = name;
1677 qname.len = len;
1678 qname.hash = full_name_hash(name, len);
1679
1680 child = d_lookup(dir, &qname);
1681 if (!child) {
1682 struct dentry *new;
1683 new = d_alloc(dir, &qname);
1684 if (new) {
1685 child = instantiate(dir->d_inode, new, task, ptr);
1686 if (child)
1687 dput(new);
1688 else
1689 child = new;
1690 }
1691 }
1692 if (!child || IS_ERR(child) || !child->d_inode)
1693 goto end_instantiate;
1694 inode = child->d_inode;
1695 if (inode) {
1696 ino = inode->i_ino;
1697 type = inode->i_mode >> 12;
1698 }
1699 dput(child);
1700end_instantiate:
1701 if (!ino)
1702 ino = find_inode_number(dir, &qname);
1703 if (!ino)
1704 ino = 1;
1705 return filldir(dirent, name, len, filp->f_pos, ino, type);
1706}
1707
28a6d671
EB		 1708static unsigned name_to_int(struct dentry *dentry)
1709{
1710 const char *name = dentry->d_name.name;
1711 int len = dentry->d_name.len;
1712 unsigned n = 0;
1713
1714 if (len > 1 && *name == '0')
1715 goto out;
1716 while (len-- > 0) {
1717 unsigned c = *name++ - '0';
1718 if (c > 9)
1719 goto out;
1720 if (n >= (~0U-9)/10)
1721 goto out;
1722 n *= 10;
1723 n += c;
1724 }
1725 return n;
1726out:
1727 return ~0U;
1728}
1729
27932742
MS		 1730#define PROC_FDINFO_MAX 64
1731
3dcd25f3 1732static int proc_fd_info(struct inode *inode, struct path *path, char *info)
28a6d671 1733{
5e442a49
LT		 1734 struct task_struct *task = get_proc_task(inode);
1735 struct files_struct *files = NULL;
28a6d671
EB		 1736 struct file *file;
1737 int fd = proc_fd(inode);
aa6afca5 1738
5e442a49
LT		 1739 if (task) {
1740 files = get_files_struct(task);
1741 put_task_struct(task);
1742 }
1743 if (files) {
1744 /*
1745 * We are not taking a ref to the file structure, so we must
1746 * hold ->file_lock.
1747 */
1748 spin_lock(&files->file_lock);
1749 file = fcheck_files(files, fd);
1750 if (file) {
1751 unsigned int f_flags;
1752 struct fdtable *fdt;
1753
1754 fdt = files_fdtable(files);
1755 f_flags = file->f_flags & ~O_CLOEXEC;
1dce27c5 1756 if (close_on_exec(fd, fdt))
5e442a49
LT		 1757 f_flags |= O_CLOEXEC;
1758
1759 if (path) {
1760 *path = file->f_path;
1761 path_get(&file->f_path);
1762 }
1763 if (info)
1764 snprintf(info, PROC_FDINFO_MAX,
1765 "pos:\t%lli\n"
1766 "flags:\t0%o\n",
1767 (long long) file->f_pos,
1768 f_flags);
1769 spin_unlock(&files->file_lock);
1770 put_files_struct(files);
1771 return 0;
99f89551 1772 }
5e442a49
LT		 1773 spin_unlock(&files->file_lock);
1774 put_files_struct(files);
1775 }
1776 return -ENOENT;
99f89551
EB		 1777}
1778
7773fbc5 1779static int proc_fd_link(struct dentry *dentry, struct path *path)
27932742 1780{
7773fbc5 1781 return proc_fd_info(dentry->d_inode, path, NULL);
27932742
MS		 1782}
1783
1da177e4
LT		 1784static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1785{
34286d66
NP		 1786 struct inode *inode;
1787 struct task_struct *task;
1788 int fd;
1da177e4 1789 struct files_struct *files;
c69e8d9c 1790 const struct cred *cred;
1da177e4 1791
34286d66
NP		 1792 if (nd && nd->flags & LOOKUP_RCU)
1793 return -ECHILD;
1794
1795 inode = dentry->d_inode;
1796 task = get_proc_task(inode);
1797 fd = proc_fd(inode);
1798
99f89551
EB		 1799 if (task) {
1800 files = get_files_struct(task);
1801 if (files) {
1802 rcu_read_lock();
1803 if (fcheck_files(files, fd)) {
1804 rcu_read_unlock();
1805 put_files_struct(files);
1806 if (task_dumpable(task)) {
c69e8d9c
DH		 1807 rcu_read_lock();
1808 cred = __task_cred(task);
1809 inode->i_uid = cred->euid;
1810 inode->i_gid = cred->egid;
1811 rcu_read_unlock();
99f89551
EB		 1812 } else {
1813 inode->i_uid = 0;
1814 inode->i_gid = 0;
1815 }
9ee8ab9f 1816 inode->i_mode &= ~(S_ISUID | S_ISGID);
99f89551
EB		 1817 security_task_to_inode(task, inode);
1818 put_task_struct(task);
1819 return 1;
1820 }
b835996f 1821 rcu_read_unlock();
1da177e4 1822 put_files_struct(files);
1da177e4 1823 }
99f89551 1824 put_task_struct(task);
1da177e4
LT		 1825 }
1826 d_drop(dentry);
1827 return 0;
1828}
1829
d72f71eb 1830static const struct dentry_operations tid_fd_dentry_operations =
1da177e4
LT		 1831{
1832 .d_revalidate = tid_fd_revalidate,
1833 .d_delete = pid_delete_dentry,
1834};
1835
444ceed8 1836static struct dentry *proc_fd_instantiate(struct inode *dir,
c5141e6d 1837 struct dentry *dentry, struct task_struct *task, const void *ptr)
1da177e4 1838{
c5141e6d 1839 unsigned fd = *(const unsigned *)ptr;
444ceed8
EB		 1840 struct file *file;
1841 struct files_struct *files;
1842 struct inode *inode;
1843 struct proc_inode *ei;
1844 struct dentry *error = ERR_PTR(-ENOENT);
1da177e4 1845
61a28784 1846 inode = proc_pid_make_inode(dir->i_sb, task);
1da177e4
LT		 1847 if (!inode)
1848 goto out;
1849 ei = PROC_I(inode);
aed7a6c4 1850 ei->fd = fd;
1da177e4
LT		 1851 files = get_files_struct(task);
1852 if (!files)
444ceed8 1853 goto out_iput;
1da177e4 1854 inode->i_mode = S_IFLNK;
ca99c1da
DS		 1855
1856 /*
1857 * We are not taking a ref to the file structure, so we must
1858 * hold ->file_lock.
1859 */
1860 spin_lock(&files->file_lock);
1da177e4
LT		 1861 file = fcheck_files(files, fd);
1862 if (!file)
444ceed8 1863 goto out_unlock;
aeb5d727 1864 if (file->f_mode & FMODE_READ)
1da177e4 1865 inode->i_mode |= S_IRUSR | S_IXUSR;
aeb5d727 1866 if (file->f_mode & FMODE_WRITE)
1da177e4 1867 inode->i_mode |= S_IWUSR | S_IXUSR;
ca99c1da 1868 spin_unlock(&files->file_lock);
1da177e4 1869 put_files_struct(files);
444ceed8 1870
5e442a49 1871 inode->i_op = &proc_pid_link_inode_operations;
1da177e4
LT		 1872 inode->i_size = 64;
1873 ei->op.proc_get_link = proc_fd_link;
fb045adb 1874 d_set_d_op(dentry, &tid_fd_dentry_operations);
1da177e4 1875 d_add(dentry, inode);
cd6a3ce9
EB		 1876 /* Close the race of the process dying before we return the dentry */
1877 if (tid_fd_revalidate(dentry, NULL))
444ceed8 1878 error = NULL;
1da177e4 1879
444ceed8
EB		 1880 out:
1881 return error;
1882out_unlock:
ca99c1da 1883 spin_unlock(&files->file_lock);
1da177e4 1884 put_files_struct(files);
444ceed8 1885out_iput:
1da177e4 1886 iput(inode);
cd6a3ce9 1887 goto out;
1da177e4
LT		 1888}
1889
27932742
MS		 1890static struct dentry *proc_lookupfd_common(struct inode *dir,
1891 struct dentry *dentry,
1892 instantiate_t instantiate)
444ceed8
EB		 1893{
1894 struct task_struct *task = get_proc_task(dir);
1895 unsigned fd = name_to_int(dentry);
1896 struct dentry *result = ERR_PTR(-ENOENT);
1897
1898 if (!task)
1899 goto out_no_task;
1900 if (fd == ~0U)
1901 goto out;
1902
27932742 1903 result = instantiate(dir, dentry, task, &fd);
444ceed8
EB		 1904out:
1905 put_task_struct(task);
1906out_no_task:
1907 return result;
1908}
1909
27932742
MS		 1910static int proc_readfd_common(struct file * filp, void * dirent,
1911 filldir_t filldir, instantiate_t instantiate)
28a6d671 1912{
2fddfeef 1913 struct dentry *dentry = filp->f_path.dentry;
28a6d671
EB		 1914 struct inode *inode = dentry->d_inode;
1915 struct task_struct *p = get_proc_task(inode);
457c2510 1916 unsigned int fd, ino;
28a6d671 1917 int retval;
28a6d671 1918 struct files_struct * files;
1da177e4 1919
28a6d671
EB		 1920 retval = -ENOENT;
1921 if (!p)
1922 goto out_no_task;
1923 retval = 0;
28a6d671
EB		 1924
1925 fd = filp->f_pos;
1926 switch (fd) {
1927 case 0:
1928 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
5e442a49 1929 goto out;
28a6d671
EB		 1930 filp->f_pos++;
1931 case 1:
1932 ino = parent_ino(dentry);
1933 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
5e442a49 1934 goto out;
28a6d671
EB		 1935 filp->f_pos++;
1936 default:
1937 files = get_files_struct(p);
1938 if (!files)
5e442a49 1939 goto out;
28a6d671 1940 rcu_read_lock();
28a6d671 1941 for (fd = filp->f_pos-2;
9b4f526c 1942 fd < files_fdtable(files)->max_fds;
28a6d671 1943 fd++, filp->f_pos++) {
27932742
MS		 1944 char name[PROC_NUMBUF];
1945 int len;
28a6d671
EB		 1946
1947 if (!fcheck_files(files, fd))
1948 continue;
1949 rcu_read_unlock();
1950
27932742
MS		 1951 len = snprintf(name, sizeof(name), "%d", fd);
1952 if (proc_fill_cache(filp, dirent, filldir,
1953 name, len, instantiate,
1954 p, &fd) < 0) {
28a6d671
EB		 1955 rcu_read_lock();
1956 break;
1957 }
1958 rcu_read_lock();
1959 }
1960 rcu_read_unlock();
1961 put_files_struct(files);
1962 }
1963out:
1964 put_task_struct(p);
1965out_no_task:
1966 return retval;
1967}
1968
27932742
MS		 1969static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1970 struct nameidata *nd)
1971{
1972 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1973}
1974
1975static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1976{
1977 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1978}
1979
1980static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1981 size_t len, loff_t *ppos)
1982{
1983 char tmp[PROC_FDINFO_MAX];
3dcd25f3 1984 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
27932742
MS		 1985 if (!err)
1986 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1987 return err;
1988}
1989
1990static const struct file_operations proc_fdinfo_file_operations = {
87df8424 1991 .open = nonseekable_open,
27932742 1992 .read = proc_fdinfo_read,
6038f373 1993 .llseek = no_llseek,
27932742
MS		 1994};
1995
00977a59 1996static const struct file_operations proc_fd_operations = {
28a6d671
EB		 1997 .read = generic_read_dir,
1998 .readdir = proc_readfd,
6038f373 1999 .llseek = default_llseek,
1da177e4
LT		 2000};
2001
640708a2
PE		 2002#ifdef CONFIG_CHECKPOINT_RESTORE
2003
2004/*
2005 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2006 * which represent vma start and end addresses.
2007 */
2008static int dname_to_vma_addr(struct dentry *dentry,
2009 unsigned long *start, unsigned long *end)
2010{
2011 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
2012 return -EINVAL;
2013
2014 return 0;
2015}
2016
2017static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
2018{
2019 unsigned long vm_start, vm_end;
2020 bool exact_vma_exists = false;
2021 struct mm_struct *mm = NULL;
2022 struct task_struct *task;
2023 const struct cred *cred;
2024 struct inode *inode;
2025 int status = 0;
2026
2027 if (nd && nd->flags & LOOKUP_RCU)
2028 return -ECHILD;
2029
2030 if (!capable(CAP_SYS_ADMIN)) {
2031 status = -EACCES;
2032 goto out_notask;
2033 }
2034
2035 inode = dentry->d_inode;
2036 task = get_proc_task(inode);
2037 if (!task)
2038 goto out_notask;
2039
2040 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2041 goto out;
2042
2043 mm = get_task_mm(task);
2044 if (!mm)
2045 goto out;
2046
2047 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2048 down_read(&mm->mmap_sem);
2049 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2050 up_read(&mm->mmap_sem);
2051 }
2052
2053 mmput(mm);
2054
2055 if (exact_vma_exists) {
2056 if (task_dumpable(task)) {
2057 rcu_read_lock();
2058 cred = __task_cred(task);
2059 inode->i_uid = cred->euid;
2060 inode->i_gid = cred->egid;
2061 rcu_read_unlock();
2062 } else {
2063 inode->i_uid = 0;
2064 inode->i_gid = 0;
2065 }
2066 security_task_to_inode(task, inode);
2067 status = 1;
2068 }
2069
2070out:
2071 put_task_struct(task);
2072
2073out_notask:
2074 if (status <= 0)
2075 d_drop(dentry);
2076
2077 return status;
2078}
2079
2080static const struct dentry_operations tid_map_files_dentry_operations = {
2081 .d_revalidate = map_files_d_revalidate,
2082 .d_delete = pid_delete_dentry,
2083};
2084
2085static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2086{
2087 unsigned long vm_start, vm_end;
2088 struct vm_area_struct *vma;
2089 struct task_struct *task;
2090 struct mm_struct *mm;
2091 int rc;
2092
2093 rc = -ENOENT;
2094 task = get_proc_task(dentry->d_inode);
2095 if (!task)
2096 goto out;
2097
2098 mm = get_task_mm(task);
2099 put_task_struct(task);
2100 if (!mm)
2101 goto out;
2102
2103 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2104 if (rc)
2105 goto out_mmput;
2106
2107 down_read(&mm->mmap_sem);
2108 vma = find_exact_vma(mm, vm_start, vm_end);
2109 if (vma && vma->vm_file) {
2110 *path = vma->vm_file->f_path;
2111 path_get(path);
2112 rc = 0;
2113 }
2114 up_read(&mm->mmap_sem);
2115
2116out_mmput:
2117 mmput(mm);
2118out:
2119 return rc;
2120}
2121
2122struct map_files_info {
2123 struct file *file;
2124 unsigned long len;
2125 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2126};
2127
2128static struct dentry *
2129proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2130 struct task_struct *task, const void *ptr)
2131{
2132 const struct file *file = ptr;
2133 struct proc_inode *ei;
2134 struct inode *inode;
2135
2136 if (!file)
2137 return ERR_PTR(-ENOENT);
2138
2139 inode = proc_pid_make_inode(dir->i_sb, task);
2140 if (!inode)
2141 return ERR_PTR(-ENOENT);
2142
2143 ei = PROC_I(inode);
2144 ei->op.proc_get_link = proc_map_files_get_link;
2145
2146 inode->i_op = &proc_pid_link_inode_operations;
2147 inode->i_size = 64;
2148 inode->i_mode = S_IFLNK;
2149
2150 if (file->f_mode & FMODE_READ)
2151 inode->i_mode |= S_IRUSR;
2152 if (file->f_mode & FMODE_WRITE)
2153 inode->i_mode |= S_IWUSR;
2154
2155 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2156 d_add(dentry, inode);
2157
2158 return NULL;
2159}
2160
2161static struct dentry *proc_map_files_lookup(struct inode *dir,
2162 struct dentry *dentry, struct nameidata *nd)
2163{
2164 unsigned long vm_start, vm_end;
2165 struct vm_area_struct *vma;
2166 struct task_struct *task;
2167 struct dentry *result;
2168 struct mm_struct *mm;
2169
2170 result = ERR_PTR(-EACCES);
2171 if (!capable(CAP_SYS_ADMIN))
2172 goto out;
2173
2174 result = ERR_PTR(-ENOENT);
2175 task = get_proc_task(dir);
2176 if (!task)
2177 goto out;
2178
2179 result = ERR_PTR(-EACCES);
2180 if (lock_trace(task))
2181 goto out_put_task;
2182
2183 result = ERR_PTR(-ENOENT);
2184 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2185 goto out_unlock;
2186
2187 mm = get_task_mm(task);
2188 if (!mm)
2189 goto out_unlock;
2190
2191 down_read(&mm->mmap_sem);
2192 vma = find_exact_vma(mm, vm_start, vm_end);
2193 if (!vma)
2194 goto out_no_vma;
2195
2196 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2197
2198out_no_vma:
2199 up_read(&mm->mmap_sem);
2200 mmput(mm);
2201out_unlock:
2202 unlock_trace(task);
2203out_put_task:
2204 put_task_struct(task);
2205out:
2206 return result;
2207}
2208
2209static const struct inode_operations proc_map_files_inode_operations = {
2210 .lookup = proc_map_files_lookup,
2211 .permission = proc_fd_permission,
2212 .setattr = proc_setattr,
2213};
2214
2215static int
2216proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2217{
2218 struct dentry *dentry = filp->f_path.dentry;
2219 struct inode *inode = dentry->d_inode;
2220 struct vm_area_struct *vma;
2221 struct task_struct *task;
2222 struct mm_struct *mm;
2223 ino_t ino;
2224 int ret;
2225
2226 ret = -EACCES;
2227 if (!capable(CAP_SYS_ADMIN))
2228 goto out;
2229
2230 ret = -ENOENT;
2231 task = get_proc_task(inode);
2232 if (!task)
2233 goto out;
2234
2235 ret = -EACCES;
2236 if (lock_trace(task))
2237 goto out_put_task;
2238
2239 ret = 0;
2240 switch (filp->f_pos) {
2241 case 0:
2242 ino = inode->i_ino;
2243 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2244 goto out_unlock;
2245 filp->f_pos++;
2246 case 1:
2247 ino = parent_ino(dentry);
2248 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2249 goto out_unlock;
2250 filp->f_pos++;
2251 default:
2252 {
2253 unsigned long nr_files, pos, i;
2254 struct flex_array *fa = NULL;
2255 struct map_files_info info;
2256 struct map_files_info *p;
2257
2258 mm = get_task_mm(task);
2259 if (!mm)
2260 goto out_unlock;
2261 down_read(&mm->mmap_sem);
2262
2263 nr_files = 0;
2264
2265 /*
2266 * We need two passes here:
2267 *
2268 * 1) Collect vmas of mapped files with mmap_sem taken
2269 * 2) Release mmap_sem and instantiate entries
2270 *
2271 * otherwise we get lockdep complained, since filldir()
2272 * routine might require mmap_sem taken in might_fault().
2273 */
2274
2275 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2276 if (vma->vm_file && ++pos > filp->f_pos)
2277 nr_files++;
2278 }
2279
2280 if (nr_files) {
2281 fa = flex_array_alloc(sizeof(info), nr_files,
2282 GFP_KERNEL);
2283 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2284 GFP_KERNEL)) {
2285 ret = -ENOMEM;
2286 if (fa)
2287 flex_array_free(fa);
2288 up_read(&mm->mmap_sem);
2289 mmput(mm);
2290 goto out_unlock;
2291 }
2292 for (i = 0, vma = mm->mmap, pos = 2; vma;
2293 vma = vma->vm_next) {
2294 if (!vma->vm_file)
2295 continue;
2296 if (++pos <= filp->f_pos)
2297 continue;
2298
2299 get_file(vma->vm_file);
2300 info.file = vma->vm_file;
2301 info.len = snprintf(info.name,
2302 sizeof(info.name), "%lx-%lx",
2303 vma->vm_start, vma->vm_end);
2304 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2305 BUG();
2306 }
2307 }
2308 up_read(&mm->mmap_sem);
2309
2310 for (i = 0; i < nr_files; i++) {
2311 p = flex_array_get(fa, i);
2312 ret = proc_fill_cache(filp, dirent, filldir,
2313 p->name, p->len,
2314 proc_map_files_instantiate,
2315 task, p->file);
2316 if (ret)
2317 break;
2318 filp->f_pos++;
2319 fput(p->file);
2320 }
2321 for (; i < nr_files; i++) {
2322 /*
2323 * In case of error don't forget
2324 * to put rest of file refs.
2325 */
2326 p = flex_array_get(fa, i);
2327 fput(p->file);
2328 }
2329 if (fa)
2330 flex_array_free(fa);
2331 mmput(mm);
2332 }
2333 }
2334
2335out_unlock:
2336 unlock_trace(task);
2337out_put_task:
2338 put_task_struct(task);
2339out:
2340 return ret;
2341}
2342
2343static const struct file_operations proc_map_files_operations = {
2344 .read = generic_read_dir,
2345 .readdir = proc_map_files_readdir,
2346 .llseek = default_llseek,
2347};
2348
2349#endif /* CONFIG_CHECKPOINT_RESTORE */
2350
8948e11f
AD		 2351/*
2352 * /proc/pid/fd needs a special permission handler so that a process can still
2353 * access /proc/self/fd after it has executed a setuid().
2354 */
10556cb2 2355static int proc_fd_permission(struct inode *inode, int mask)
8948e11f 2356{
2830ba7f 2357 int rv = generic_permission(inode, mask);
8948e11f
AD		 2358 if (rv == 0)
2359 return 0;
2360 if (task_pid(current) == proc_pid(inode))
2361 rv = 0;
2362 return rv;
2363}
2364
1da177e4
LT		 2365/*
2366 * proc directories can do almost nothing..
2367 */
c5ef1c42 2368static const struct inode_operations proc_fd_inode_operations = {
1da177e4 2369 .lookup = proc_lookupfd,
8948e11f 2370 .permission = proc_fd_permission,
6d76fa58 2371 .setattr = proc_setattr,
1da177e4
LT		 2372};
2373
27932742
MS		 2374static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2375 struct dentry *dentry, struct task_struct *task, const void *ptr)
2376{
2377 unsigned fd = *(unsigned *)ptr;
2378 struct inode *inode;
2379 struct proc_inode *ei;
2380 struct dentry *error = ERR_PTR(-ENOENT);
2381
2382 inode = proc_pid_make_inode(dir->i_sb, task);
2383 if (!inode)
2384 goto out;
2385 ei = PROC_I(inode);
2386 ei->fd = fd;
2387 inode->i_mode = S_IFREG | S_IRUSR;
2388 inode->i_fop = &proc_fdinfo_file_operations;
fb045adb 2389 d_set_d_op(dentry, &tid_fd_dentry_operations);
27932742
MS		 2390 d_add(dentry, inode);
2391 /* Close the race of the process dying before we return the dentry */
2392 if (tid_fd_revalidate(dentry, NULL))
2393 error = NULL;
2394
2395 out:
2396 return error;
2397}
2398
2399static struct dentry *proc_lookupfdinfo(struct inode *dir,
2400 struct dentry *dentry,
2401 struct nameidata *nd)
2402{
2403 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2404}
2405
2406static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2407{
2408 return proc_readfd_common(filp, dirent, filldir,
2409 proc_fdinfo_instantiate);
2410}
2411
2412static const struct file_operations proc_fdinfo_operations = {
2413 .read = generic_read_dir,
2414 .readdir = proc_readfdinfo,
6038f373 2415 .llseek = default_llseek,
27932742
MS		 2416};
2417
2418/*
2419 * proc directories can do almost nothing..
2420 */
2421static const struct inode_operations proc_fdinfo_inode_operations = {
2422 .lookup = proc_lookupfdinfo,
2423 .setattr = proc_setattr,
2424};
2425
2426
444ceed8 2427static struct dentry *proc_pident_instantiate(struct inode *dir,
c5141e6d 2428 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8 2429{
c5141e6d 2430 const struct pid_entry *p = ptr;
444ceed8
EB		 2431 struct inode *inode;
2432 struct proc_inode *ei;
bd6daba9 2433 struct dentry *error = ERR_PTR(-ENOENT);
444ceed8 2434
61a28784 2435 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 2436 if (!inode)
2437 goto out;
2438
2439 ei = PROC_I(inode);
2440 inode->i_mode = p->mode;
2441 if (S_ISDIR(inode->i_mode))
bfe86848 2442 set_nlink(inode, 2); /* Use getattr to fix if necessary */
444ceed8
EB		 2443 if (p->iop)
2444 inode->i_op = p->iop;
2445 if (p->fop)
2446 inode->i_fop = p->fop;
2447 ei->op = p->op;
fb045adb 2448 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 2449 d_add(dentry, inode);
2450 /* Close the race of the process dying before we return the dentry */
2451 if (pid_revalidate(dentry, NULL))
2452 error = NULL;
2453out:
2454 return error;
2455}
2456
1da177e4
LT		 2457static struct dentry *proc_pident_lookup(struct inode *dir,
2458 struct dentry *dentry,
c5141e6d 2459 const struct pid_entry *ents,
7bcd6b0e 2460 unsigned int nents)
1da177e4 2461{
cd6a3ce9 2462 struct dentry *error;
99f89551 2463 struct task_struct *task = get_proc_task(dir);
c5141e6d 2464 const struct pid_entry *p, *last;
1da177e4 2465
cd6a3ce9 2466 error = ERR_PTR(-ENOENT);
1da177e4 2467
99f89551
EB		 2468 if (!task)
2469 goto out_no_task;
1da177e4 2470
20cdc894
EB		 2471 /*
2472 * Yes, it does not scale. And it should not. Don't add
2473 * new entries into /proc/<tgid>/ without very good reasons.
2474 */
7bcd6b0e
EB		 2475 last = &ents[nents - 1];
2476 for (p = ents; p <= last; p++) {
1da177e4
LT		 2477 if (p->len != dentry->d_name.len)
2478 continue;
2479 if (!memcmp(dentry->d_name.name, p->name, p->len))
2480 break;
2481 }
7bcd6b0e 2482 if (p > last)
1da177e4
LT		 2483 goto out;
2484
444ceed8 2485 error = proc_pident_instantiate(dir, dentry, task, p);
1da177e4 2486out:
99f89551
EB		 2487 put_task_struct(task);
2488out_no_task:
cd6a3ce9 2489 return error;
1da177e4
LT		 2490}
2491
c5141e6d
ED		 2492static int proc_pident_fill_cache(struct file *filp, void *dirent,
2493 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
61a28784
EB		 2494{
2495 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2496 proc_pident_instantiate, task, p);
2497}
2498
28a6d671
EB		 2499static int proc_pident_readdir(struct file *filp,
2500 void *dirent, filldir_t filldir,
c5141e6d 2501 const struct pid_entry *ents, unsigned int nents)
28a6d671
EB		 2502{
2503 int i;
2fddfeef 2504 struct dentry *dentry = filp->f_path.dentry;
28a6d671
EB		 2505 struct inode *inode = dentry->d_inode;
2506 struct task_struct *task = get_proc_task(inode);
c5141e6d 2507 const struct pid_entry *p, *last;
28a6d671
EB		 2508 ino_t ino;
2509 int ret;
2510
2511 ret = -ENOENT;
2512 if (!task)
61a28784 2513 goto out_no_task;
28a6d671
EB		 2514
2515 ret = 0;
28a6d671
EB		 2516 i = filp->f_pos;
2517 switch (i) {
2518 case 0:
2519 ino = inode->i_ino;
2520 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2521 goto out;
2522 i++;
2523 filp->f_pos++;
2524 /* fall through */
2525 case 1:
2526 ino = parent_ino(dentry);
2527 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2528 goto out;
2529 i++;
2530 filp->f_pos++;
2531 /* fall through */
2532 default:
2533 i -= 2;
2534 if (i >= nents) {
2535 ret = 1;
2536 goto out;
2537 }
2538 p = ents + i;
7bcd6b0e
EB		 2539 last = &ents[nents - 1];
2540 while (p <= last) {
61a28784 2541 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
28a6d671
EB		 2542 goto out;
2543 filp->f_pos++;
2544 p++;
2545 }
2546 }
2547
2548 ret = 1;
2549out:
61a28784
EB		 2550 put_task_struct(task);
2551out_no_task:
28a6d671 2552 return ret;
1da177e4
LT		 2553}
2554
28a6d671
EB		 2555#ifdef CONFIG_SECURITY
2556static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2557 size_t count, loff_t *ppos)
2558{
2fddfeef 2559 struct inode * inode = file->f_path.dentry->d_inode;
04ff9708 2560 char *p = NULL;
28a6d671
EB		 2561 ssize_t length;
2562 struct task_struct *task = get_proc_task(inode);
2563
28a6d671 2564 if (!task)
04ff9708 2565 return -ESRCH;
28a6d671
EB		 2566
2567 length = security_getprocattr(task,
2fddfeef 2568 (char*)file->f_path.dentry->d_name.name,
04ff9708 2569 &p);
28a6d671 2570 put_task_struct(task);
04ff9708
AV		 2571 if (length > 0)
2572 length = simple_read_from_buffer(buf, count, ppos, p, length);
2573 kfree(p);
28a6d671 2574 return length;
1da177e4
LT		 2575}
2576
28a6d671
EB		 2577static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2578 size_t count, loff_t *ppos)
2579{
2fddfeef 2580 struct inode * inode = file->f_path.dentry->d_inode;
28a6d671
EB		 2581 char *page;
2582 ssize_t length;
2583 struct task_struct *task = get_proc_task(inode);
2584
2585 length = -ESRCH;
2586 if (!task)
2587 goto out_no_task;
2588 if (count > PAGE_SIZE)
2589 count = PAGE_SIZE;
2590
2591 /* No partial writes. */
2592 length = -EINVAL;
2593 if (*ppos != 0)
2594 goto out;
2595
2596 length = -ENOMEM;
e12ba74d 2597 page = (char*)__get_free_page(GFP_TEMPORARY);
28a6d671
EB		 2598 if (!page)
2599 goto out;
2600
2601 length = -EFAULT;
2602 if (copy_from_user(page, buf, count))
2603 goto out_free;
2604
107db7c7 2605 /* Guard against adverse ptrace interaction */
9b1bf12d 2606 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
107db7c7
DH		 2607 if (length < 0)
2608 goto out_free;
2609
28a6d671 2610 length = security_setprocattr(task,
2fddfeef 2611 (char*)file->f_path.dentry->d_name.name,
28a6d671 2612 (void*)page, count);
9b1bf12d 2613 mutex_unlock(&task->signal->cred_guard_mutex);
28a6d671
EB		 2614out_free:
2615 free_page((unsigned long) page);
2616out:
2617 put_task_struct(task);
2618out_no_task:
2619 return length;
2620}
2621
00977a59 2622static const struct file_operations proc_pid_attr_operations = {
28a6d671
EB		 2623 .read = proc_pid_attr_read,
2624 .write = proc_pid_attr_write,
87df8424 2625 .llseek = generic_file_llseek,
28a6d671
EB		 2626};
2627
c5141e6d 2628static const struct pid_entry attr_dir_stuff[] = {
631f9c18
AD		 2629 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2630 REG("prev", S_IRUGO, proc_pid_attr_operations),
2631 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2632 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2633 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2634 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
28a6d671
EB		 2635};
2636
72d9dcfc 2637static int proc_attr_dir_readdir(struct file * filp,
28a6d671
EB		 2638 void * dirent, filldir_t filldir)
2639{
2640 return proc_pident_readdir(filp,dirent,filldir,
72d9dcfc 2641 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2642}
2643
00977a59 2644static const struct file_operations proc_attr_dir_operations = {
1da177e4 2645 .read = generic_read_dir,
72d9dcfc 2646 .readdir = proc_attr_dir_readdir,
6038f373 2647 .llseek = default_llseek,
1da177e4
LT		 2648};
2649
72d9dcfc 2650static struct dentry *proc_attr_dir_lookup(struct inode *dir,
28a6d671
EB		 2651 struct dentry *dentry, struct nameidata *nd)
2652{
7bcd6b0e
EB		 2653 return proc_pident_lookup(dir, dentry,
2654 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2655}
2656
c5ef1c42 2657static const struct inode_operations proc_attr_dir_inode_operations = {
72d9dcfc 2658 .lookup = proc_attr_dir_lookup,
99f89551 2659 .getattr = pid_getattr,
6d76fa58 2660 .setattr = proc_setattr,
1da177e4
LT		 2661};
2662
28a6d671
EB		 2663#endif
2664
698ba7b5 2665#ifdef CONFIG_ELF_CORE
3cb4a0bb
KH		 2666static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2667 size_t count, loff_t *ppos)
2668{
2669 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2670 struct mm_struct *mm;
2671 char buffer[PROC_NUMBUF];
2672 size_t len;
2673 int ret;
2674
2675 if (!task)
2676 return -ESRCH;
2677
2678 ret = 0;
2679 mm = get_task_mm(task);
2680 if (mm) {
2681 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2682 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2683 MMF_DUMP_FILTER_SHIFT));
2684 mmput(mm);
2685 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2686 }
2687
2688 put_task_struct(task);
2689
2690 return ret;
2691}
2692
2693static ssize_t proc_coredump_filter_write(struct file *file,
2694 const char __user *buf,
2695 size_t count,
2696 loff_t *ppos)
2697{
2698 struct task_struct *task;
2699 struct mm_struct *mm;
2700 char buffer[PROC_NUMBUF], *end;
2701 unsigned int val;
2702 int ret;
2703 int i;
2704 unsigned long mask;
2705
2706 ret = -EFAULT;
2707 memset(buffer, 0, sizeof(buffer));
2708 if (count > sizeof(buffer) - 1)
2709 count = sizeof(buffer) - 1;
2710 if (copy_from_user(buffer, buf, count))
2711 goto out_no_task;
2712
2713 ret = -EINVAL;
2714 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2715 if (*end == '\n')
2716 end++;
2717 if (end - buffer == 0)
2718 goto out_no_task;
2719
2720 ret = -ESRCH;
2721 task = get_proc_task(file->f_dentry->d_inode);
2722 if (!task)
2723 goto out_no_task;
2724
2725 ret = end - buffer;
2726 mm = get_task_mm(task);
2727 if (!mm)
2728 goto out_no_mm;
2729
2730 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2731 if (val & mask)
2732 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2733 else
2734 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2735 }
2736
2737 mmput(mm);
2738 out_no_mm:
2739 put_task_struct(task);
2740 out_no_task:
2741 return ret;
2742}
2743
2744static const struct file_operations proc_coredump_filter_operations = {
2745 .read = proc_coredump_filter_read,
2746 .write = proc_coredump_filter_write,
87df8424 2747 .llseek = generic_file_llseek,
3cb4a0bb
KH		 2748};
2749#endif
2750
28a6d671
EB		 2751/*
2752 * /proc/self:
2753 */
2754static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2755 int buflen)
2756{
488e5bc4 2757 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
b55fcb22 2758 pid_t tgid = task_tgid_nr_ns(current, ns);
28a6d671 2759 char tmp[PROC_NUMBUF];
b55fcb22 2760 if (!tgid)
488e5bc4 2761 return -ENOENT;
b55fcb22 2762 sprintf(tmp, "%d", tgid);
28a6d671
EB		 2763 return vfs_readlink(dentry,buffer,buflen,tmp);
2764}
2765
2766static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2767{
488e5bc4 2768 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
b55fcb22 2769 pid_t tgid = task_tgid_nr_ns(current, ns);
7fee4868
AV		 2770 char *name = ERR_PTR(-ENOENT);
2771 if (tgid) {
2772 name = __getname();
2773 if (!name)
2774 name = ERR_PTR(-ENOMEM);
2775 else
2776 sprintf(name, "%d", tgid);
2777 }
2778 nd_set_link(nd, name);
2779 return NULL;
2780}
2781
2782static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2783 void *cookie)
2784{
2785 char *s = nd_get_link(nd);
2786 if (!IS_ERR(s))
2787 __putname(s);
28a6d671
EB		 2788}
2789
c5ef1c42 2790static const struct inode_operations proc_self_inode_operations = {
28a6d671
EB		 2791 .readlink = proc_self_readlink,
2792 .follow_link = proc_self_follow_link,
7fee4868 2793 .put_link = proc_self_put_link,
28a6d671
EB		 2794};
2795
801199ce
EB		 2796/*
2797 * proc base
2798 *
2799 * These are the directory entries in the root directory of /proc
2800 * that properly belong to the /proc filesystem, as they describe
2801 * describe something that is process related.
2802 */
c5141e6d 2803static const struct pid_entry proc_base_stuff[] = {
61a28784 2804 NOD("self", S_IFLNK|S_IRWXUGO,
801199ce 2805 &proc_self_inode_operations, NULL, {}),
801199ce
EB		 2806};
2807
444ceed8 2808static struct dentry *proc_base_instantiate(struct inode *dir,
c5141e6d 2809 struct dentry *dentry, struct task_struct *task, const void *ptr)
801199ce 2810{
c5141e6d 2811 const struct pid_entry *p = ptr;
801199ce 2812 struct inode *inode;
801199ce 2813 struct proc_inode *ei;
73d36460 2814 struct dentry *error;
801199ce
EB		 2815
2816 /* Allocate the inode */
2817 error = ERR_PTR(-ENOMEM);
2818 inode = new_inode(dir->i_sb);
2819 if (!inode)
2820 goto out;
2821
2822 /* Initialize the inode */
2823 ei = PROC_I(inode);
85fe4025 2824 inode->i_ino = get_next_ino();
801199ce 2825 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
801199ce
EB		 2826
2827 /*
2828 * grab the reference to the task.
2829 */
1a657f78 2830 ei->pid = get_task_pid(task, PIDTYPE_PID);
801199ce
EB		 2831 if (!ei->pid)
2832 goto out_iput;
2833
801199ce
EB		 2834 inode->i_mode = p->mode;
2835 if (S_ISDIR(inode->i_mode))
bfe86848 2836 set_nlink(inode, 2);
801199ce
EB		 2837 if (S_ISLNK(inode->i_mode))
2838 inode->i_size = 64;
2839 if (p->iop)
2840 inode->i_op = p->iop;
2841 if (p->fop)
2842 inode->i_fop = p->fop;
2843 ei->op = p->op;
801199ce
EB		 2844 d_add(dentry, inode);
2845 error = NULL;
2846out:
801199ce
EB		 2847 return error;
2848out_iput:
2849 iput(inode);
2850 goto out;
2851}
2852
444ceed8
EB		 2853static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2854{
2855 struct dentry *error;
2856 struct task_struct *task = get_proc_task(dir);
c5141e6d 2857 const struct pid_entry *p, *last;
444ceed8
EB		 2858
2859 error = ERR_PTR(-ENOENT);
2860
2861 if (!task)
2862 goto out_no_task;
2863
2864 /* Lookup the directory entry */
7bcd6b0e
EB		 2865 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2866 for (p = proc_base_stuff; p <= last; p++) {
444ceed8
EB		 2867 if (p->len != dentry->d_name.len)
2868 continue;
2869 if (!memcmp(dentry->d_name.name, p->name, p->len))
2870 break;
2871 }
7bcd6b0e 2872 if (p > last)
444ceed8
EB		 2873 goto out;
2874
2875 error = proc_base_instantiate(dir, dentry, task, p);
2876
2877out:
2878 put_task_struct(task);
2879out_no_task:
2880 return error;
2881}
2882
c5141e6d
ED		 2883static int proc_base_fill_cache(struct file *filp, void *dirent,
2884 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
61a28784
EB		 2885{
2886 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2887 proc_base_instantiate, task, p);
2888}
2889
aba76fdb 2890#ifdef CONFIG_TASK_IO_ACCOUNTING
297c5d92
AR		 2891static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2892{
940389b8 2893 struct task_io_accounting acct = task->ioac;
5995477a 2894 unsigned long flags;
293eb1e7 2895 int result;
5995477a 2896
293eb1e7
VK		 2897 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2898 if (result)
2899 return result;
2900
2901 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2902 result = -EACCES;
2903 goto out_unlock;
2904 }
1d1221f3 2905
5995477a
AR		 2906 if (whole && lock_task_sighand(task, &flags)) {
2907 struct task_struct *t = task;
2908
2909 task_io_accounting_add(&acct, &task->signal->ioac);
2910 while_each_thread(task, t)
2911 task_io_accounting_add(&acct, &t->ioac);
2912
2913 unlock_task_sighand(task, &flags);
297c5d92 2914 }
293eb1e7 2915 result = sprintf(buffer,
aba76fdb
AM		 2916 "rchar: %llu\n"
2917 "wchar: %llu\n"
2918 "syscr: %llu\n"
2919 "syscw: %llu\n"
2920 "read_bytes: %llu\n"
2921 "write_bytes: %llu\n"
2922 "cancelled_write_bytes: %llu\n",
7c44319d
AB		 2923 (unsigned long long)acct.rchar,
2924 (unsigned long long)acct.wchar,
2925 (unsigned long long)acct.syscr,
2926 (unsigned long long)acct.syscw,
2927 (unsigned long long)acct.read_bytes,
2928 (unsigned long long)acct.write_bytes,
2929 (unsigned long long)acct.cancelled_write_bytes);
293eb1e7
VK		 2930out_unlock:
2931 mutex_unlock(&task->signal->cred_guard_mutex);
2932 return result;
297c5d92
AR		 2933}
2934
2935static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2936{
2937 return do_io_accounting(task, buffer, 0);
aba76fdb 2938}
297c5d92
AR		 2939
2940static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2941{
2942 return do_io_accounting(task, buffer, 1);
2943}
2944#endif /* CONFIG_TASK_IO_ACCOUNTING */
aba76fdb 2945
47830723
KC		 2946static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2947 struct pid *pid, struct task_struct *task)
2948{
a9712bc1
AV		 2949 int err = lock_trace(task);
2950 if (!err) {
2951 seq_printf(m, "%08x\n", task->personality);
2952 unlock_trace(task);
2953 }
2954 return err;
47830723
KC		 2955}
2956
28a6d671
EB		 2957/*
2958 * Thread groups
2959 */
00977a59 2960static const struct file_operations proc_task_operations;
c5ef1c42 2961static const struct inode_operations proc_task_inode_operations;
20cdc894 2962
c5141e6d 2963static const struct pid_entry tgid_base_stuff[] = {
631f9c18
AD		 2964 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2965 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
640708a2
PE		 2966#ifdef CONFIG_CHECKPOINT_RESTORE
2967 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2968#endif
631f9c18 2969 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 2970 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
b2211a36 2971#ifdef CONFIG_NET
631f9c18 2972 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
b2211a36 2973#endif
631f9c18
AD		 2974 REG("environ", S_IRUSR, proc_environ_operations),
2975 INF("auxv", S_IRUSR, proc_pid_auxv),
2976 ONE("status", S_IRUGO, proc_pid_status),
a9712bc1 2977 ONE("personality", S_IRUGO, proc_pid_personality),
3036e7b4 2978 INF("limits", S_IRUGO, proc_pid_limits),
43ae34cb 2979#ifdef CONFIG_SCHED_DEBUG
631f9c18 2980 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
5091faa4
MG		 2981#endif
2982#ifdef CONFIG_SCHED_AUTOGROUP
2983 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
ebcb6734 2984#endif
4614a696 2985 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 2986#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
a9712bc1 2987 INF("syscall", S_IRUGO, proc_pid_syscall),
43ae34cb 2988#endif
631f9c18
AD		 2989 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2990 ONE("stat", S_IRUGO, proc_tgid_stat),
2991 ONE("statm", S_IRUGO, proc_pid_statm),
b7643757 2992 REG("maps", S_IRUGO, proc_pid_maps_operations),
28a6d671 2993#ifdef CONFIG_NUMA
b7643757 2994 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
28a6d671 2995#endif
631f9c18
AD		 2996 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2997 LNK("cwd", proc_cwd_link),
2998 LNK("root", proc_root_link),
2999 LNK("exe", proc_exe_link),
3000 REG("mounts", S_IRUGO, proc_mounts_operations),
3001 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3002 REG("mountstats", S_IRUSR, proc_mountstats_operations),
1e883281 3003#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 3004 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
b7643757 3005 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
ca6b0bf0 3006 REG("pagemap", S_IRUGO, proc_pagemap_operations),
28a6d671
EB		 3007#endif
3008#ifdef CONFIG_SECURITY
631f9c18 3009 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 3010#endif
3011#ifdef CONFIG_KALLSYMS
631f9c18 3012 INF("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 3013#endif
2ec220e2 3014#ifdef CONFIG_STACKTRACE
a9712bc1 3015 ONE("stack", S_IRUGO, proc_pid_stack),
28a6d671
EB		 3016#endif
3017#ifdef CONFIG_SCHEDSTATS
631f9c18 3018 INF("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 3019#endif
9745512c 3020#ifdef CONFIG_LATENCYTOP
631f9c18 3021 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 3022#endif
8793d854 3023#ifdef CONFIG_PROC_PID_CPUSET
631f9c18 3024 REG("cpuset", S_IRUGO, proc_cpuset_operations),
a424316c
PM		 3025#endif
3026#ifdef CONFIG_CGROUPS
631f9c18 3027 REG("cgroup", S_IRUGO, proc_cgroup_operations),
28a6d671 3028#endif
631f9c18
AD		 3029 INF("oom_score", S_IRUGO, proc_oom_score),
3030 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
a63d83f4 3031 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 3032#ifdef CONFIG_AUDITSYSCALL
631f9c18
AD		 3033 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3034 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 3035#endif
f4f154fd 3036#ifdef CONFIG_FAULT_INJECTION
631f9c18 3037 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 3038#endif
698ba7b5 3039#ifdef CONFIG_ELF_CORE
631f9c18 3040 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3cb4a0bb 3041#endif
aba76fdb 3042#ifdef CONFIG_TASK_IO_ACCOUNTING
1d1221f3 3043 INF("io", S_IRUSR, proc_tgid_io_accounting),
aba76fdb 3044#endif
f133ecca
CM		 3045#ifdef CONFIG_HARDWALL
3046 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3047#endif
28a6d671 3048};
1da177e4 3049
28a6d671 3050static int proc_tgid_base_readdir(struct file * filp,
1da177e4
LT		 3051 void * dirent, filldir_t filldir)
3052{
3053 return proc_pident_readdir(filp,dirent,filldir,
28a6d671 3054 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 3055}
3056
00977a59 3057static const struct file_operations proc_tgid_base_operations = {
1da177e4 3058 .read = generic_read_dir,
28a6d671 3059 .readdir = proc_tgid_base_readdir,
6038f373 3060 .llseek = default_llseek,
1da177e4
LT		 3061};
3062
28a6d671 3063static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
7bcd6b0e
EB		 3064 return proc_pident_lookup(dir, dentry,
3065 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 3066}
3067
c5ef1c42 3068static const struct inode_operations proc_tgid_base_inode_operations = {
28a6d671 3069 .lookup = proc_tgid_base_lookup,
99f89551 3070 .getattr = pid_getattr,
6d76fa58 3071 .setattr = proc_setattr,
0499680a 3072 .permission = proc_pid_permission,
1da177e4 3073};
1da177e4 3074
60347f67 3075static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
1da177e4 3076{
48e6484d 3077 struct dentry *dentry, *leader, *dir;
8578cea7 3078 char buf[PROC_NUMBUF];
48e6484d
EB		 3079 struct qstr name;
3080
3081 name.name = buf;
60347f67
PE		 3082 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3083 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d 3084 if (dentry) {
29f12ca3 3085 shrink_dcache_parent(dentry);
48e6484d
EB		 3086 d_drop(dentry);
3087 dput(dentry);
3088 }
1da177e4 3089
48e6484d 3090 name.name = buf;
60347f67
PE		 3091 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3092 leader = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d
EB		 3093 if (!leader)
3094 goto out;
1da177e4 3095
48e6484d
EB		 3096 name.name = "task";
3097 name.len = strlen(name.name);
3098 dir = d_hash_and_lookup(leader, &name);
3099 if (!dir)
3100 goto out_put_leader;
3101
3102 name.name = buf;
60347f67 3103 name.len = snprintf(buf, sizeof(buf), "%d", pid);
48e6484d
EB		 3104 dentry = d_hash_and_lookup(dir, &name);
3105 if (dentry) {
3106 shrink_dcache_parent(dentry);
3107 d_drop(dentry);
3108 dput(dentry);
1da177e4 3109 }
48e6484d
EB		 3110
3111 dput(dir);
3112out_put_leader:
3113 dput(leader);
3114out:
3115 return;
1da177e4
LT		 3116}
3117
0895e91d
RD		 3118/**
3119 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3120 * @task: task that should be flushed.
3121 *
3122 * When flushing dentries from proc, one needs to flush them from global
60347f67 3123 * proc (proc_mnt) and from all the namespaces' procs this task was seen
0895e91d
RD		 3124 * in. This call is supposed to do all of this job.
3125 *
3126 * Looks in the dcache for
3127 * /proc/@pid
3128 * /proc/@tgid/task/@pid
3129 * if either directory is present flushes it and all of it'ts children
3130 * from the dcache.
3131 *
3132 * It is safe and reasonable to cache /proc entries for a task until
3133 * that task exits. After that they just clog up the dcache with
3134 * useless entries, possibly causing useful dcache entries to be
3135 * flushed instead. This routine is proved to flush those useless
3136 * dcache entries at process exit time.
3137 *
3138 * NOTE: This routine is just an optimization so it does not guarantee
3139 * that no dcache entries will exist at process exit time it
3140 * just makes it very unlikely that any will persist.
60347f67
PE		 3141 */
3142
3143void proc_flush_task(struct task_struct *task)
3144{
9fcc2d15 3145 int i;
9b4d1cbe 3146 struct pid *pid, *tgid;
130f77ec
PE		 3147 struct upid *upid;
3148
130f77ec 3149 pid = task_pid(task);
9b4d1cbe 3150 tgid = task_tgid(task);
130f77ec 3151
9fcc2d15 3152 for (i = 0; i <= pid->level; i++) {
130f77ec
PE		 3153 upid = &pid->numbers[i];
3154 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
9b4d1cbe 3155 tgid->numbers[i].nr);
130f77ec 3156 }
6f4e6433
PE		 3157
3158 upid = &pid->numbers[pid->level];
3159 if (upid->nr == 1)
3160 pid_ns_release_proc(upid->ns);
60347f67
PE		 3161}
3162
9711ef99
AB		 3163static struct dentry *proc_pid_instantiate(struct inode *dir,
3164 struct dentry * dentry,
c5141e6d 3165 struct task_struct *task, const void *ptr)
444ceed8
EB		 3166{
3167 struct dentry *error = ERR_PTR(-ENOENT);
3168 struct inode *inode;
3169
61a28784 3170 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 3171 if (!inode)
3172 goto out;
3173
3174 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3175 inode->i_op = &proc_tgid_base_inode_operations;
3176 inode->i_fop = &proc_tgid_base_operations;
3177 inode->i_flags|=S_IMMUTABLE;
aed54175 3178
bfe86848
MS		 3179 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3180 ARRAY_SIZE(tgid_base_stuff)));
444ceed8 3181
fb045adb 3182 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 3183
3184 d_add(dentry, inode);
3185 /* Close the race of the process dying before we return the dentry */
3186 if (pid_revalidate(dentry, NULL))
3187 error = NULL;
3188out:
3189 return error;
3190}
3191
1da177e4
LT		 3192struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3193{
73d36460 3194 struct dentry *result;
1da177e4 3195 struct task_struct *task;
1da177e4 3196 unsigned tgid;
b488893a 3197 struct pid_namespace *ns;
1da177e4 3198
801199ce
EB		 3199 result = proc_base_lookup(dir, dentry);
3200 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3201 goto out;
3202
1da177e4
LT		 3203 tgid = name_to_int(dentry);
3204 if (tgid == ~0U)
3205 goto out;
3206
b488893a 3207 ns = dentry->d_sb->s_fs_info;
de758734 3208 rcu_read_lock();
b488893a 3209 task = find_task_by_pid_ns(tgid, ns);
1da177e4
LT		 3210 if (task)
3211 get_task_struct(task);
de758734 3212 rcu_read_unlock();
1da177e4
LT		 3213 if (!task)
3214 goto out;
3215
444ceed8 3216 result = proc_pid_instantiate(dir, dentry, task, NULL);
1da177e4 3217 put_task_struct(task);
1da177e4 3218out:
cd6a3ce9 3219 return result;
1da177e4
LT		 3220}
3221
1da177e4 3222/*
0804ef4b 3223 * Find the first task with tgid >= tgid
0bc58a91 3224 *
1da177e4 3225 */
19fd4bb2
EB		 3226struct tgid_iter {
3227 unsigned int tgid;
0804ef4b 3228 struct task_struct *task;
19fd4bb2
EB		 3229};
3230static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3231{
0804ef4b 3232 struct pid *pid;
1da177e4 3233
19fd4bb2
EB		 3234 if (iter.task)
3235 put_task_struct(iter.task);
454cc105 3236 rcu_read_lock();
0804ef4b 3237retry:
19fd4bb2
EB		 3238 iter.task = NULL;
3239 pid = find_ge_pid(iter.tgid, ns);
0804ef4b 3240 if (pid) {
19fd4bb2
EB		 3241 iter.tgid = pid_nr_ns(pid, ns);
3242 iter.task = pid_task(pid, PIDTYPE_PID);
0804ef4b
EB		 3243 /* What we to know is if the pid we have find is the
3244 * pid of a thread_group_leader. Testing for task
3245 * being a thread_group_leader is the obvious thing
3246 * todo but there is a window when it fails, due to
3247 * the pid transfer logic in de_thread.
3248 *
3249 * So we perform the straight forward test of seeing
3250 * if the pid we have found is the pid of a thread
3251 * group leader, and don't worry if the task we have
3252 * found doesn't happen to be a thread group leader.
3253 * As we don't care in the case of readdir.
3254 */
19fd4bb2
EB		 3255 if (!iter.task || !has_group_leader_pid(iter.task)) {
3256 iter.tgid += 1;
0804ef4b 3257 goto retry;
19fd4bb2
EB		 3258 }
3259 get_task_struct(iter.task);
0bc58a91 3260 }
454cc105 3261 rcu_read_unlock();
19fd4bb2 3262 return iter;
1da177e4
LT		 3263}
3264
7bcd6b0e 3265#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
0804ef4b 3266
61a28784 3267static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
19fd4bb2 3268 struct tgid_iter iter)
61a28784
EB		 3269{
3270 char name[PROC_NUMBUF];
19fd4bb2 3271 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
61a28784 3272 return proc_fill_cache(filp, dirent, filldir, name, len,
19fd4bb2 3273 proc_pid_instantiate, iter.task, NULL);
61a28784
EB		 3274}
3275
0499680a
VK		 3276static int fake_filldir(void *buf, const char *name, int namelen,
3277 loff_t offset, u64 ino, unsigned d_type)
3278{
3279 return 0;
3280}
3281
1da177e4
LT		 3282/* for the /proc/ directory itself, after non-process stuff has been done */
3283int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3284{
d8bdc59f
LT		 3285 unsigned int nr;
3286 struct task_struct *reaper;
19fd4bb2 3287 struct tgid_iter iter;
b488893a 3288 struct pid_namespace *ns;
0499680a 3289 filldir_t __filldir;
1da177e4 3290
d8bdc59f
LT		 3291 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3292 goto out_no_task;
3293 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3294
3295 reaper = get_proc_task(filp->f_path.dentry->d_inode);
61a28784
EB		 3296 if (!reaper)
3297 goto out_no_task;
3298
7bcd6b0e 3299 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
c5141e6d 3300 const struct pid_entry *p = &proc_base_stuff[nr];
61a28784 3301 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
801199ce 3302 goto out;
1da177e4
LT		 3303 }
3304
b488893a 3305 ns = filp->f_dentry->d_sb->s_fs_info;
19fd4bb2
EB		 3306 iter.task = NULL;
3307 iter.tgid = filp->f_pos - TGID_OFFSET;
3308 for (iter = next_tgid(ns, iter);
3309 iter.task;
3310 iter.tgid += 1, iter = next_tgid(ns, iter)) {
0499680a
VK		 3311 if (has_pid_permissions(ns, iter.task, 2))
3312 __filldir = filldir;
3313 else
3314 __filldir = fake_filldir;
3315
19fd4bb2 3316 filp->f_pos = iter.tgid + TGID_OFFSET;
0499680a 3317 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
19fd4bb2 3318 put_task_struct(iter.task);
0804ef4b 3319 goto out;
1da177e4 3320 }
0bc58a91 3321 }
0804ef4b
EB		 3322 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3323out:
61a28784
EB		 3324 put_task_struct(reaper);
3325out_no_task:
0bc58a91
EB		 3326 return 0;
3327}
1da177e4 3328
28a6d671
EB		 3329/*
3330 * Tasks
3331 */
c5141e6d 3332static const struct pid_entry tid_base_stuff[] = {
631f9c18 3333 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3835541d 3334 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
6b4e306a 3335 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
631f9c18
AD		 3336 REG("environ", S_IRUSR, proc_environ_operations),
3337 INF("auxv", S_IRUSR, proc_pid_auxv),
3338 ONE("status", S_IRUGO, proc_pid_status),
a9712bc1 3339 ONE("personality", S_IRUGO, proc_pid_personality),
3036e7b4 3340 INF("limits", S_IRUGO, proc_pid_limits),
43ae34cb 3341#ifdef CONFIG_SCHED_DEBUG
631f9c18 3342 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
ebcb6734 3343#endif
4614a696 3344 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 3345#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
a9712bc1 3346 INF("syscall", S_IRUGO, proc_pid_syscall),
43ae34cb 3347#endif
631f9c18
AD		 3348 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3349 ONE("stat", S_IRUGO, proc_tid_stat),
3350 ONE("statm", S_IRUGO, proc_pid_statm),
b7643757 3351 REG("maps", S_IRUGO, proc_tid_maps_operations),
28a6d671 3352#ifdef CONFIG_NUMA
b7643757 3353 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
28a6d671 3354#endif
631f9c18
AD		 3355 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3356 LNK("cwd", proc_cwd_link),
3357 LNK("root", proc_root_link),
3358 LNK("exe", proc_exe_link),
3359 REG("mounts", S_IRUGO, proc_mounts_operations),
3360 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
1e883281 3361#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18 3362 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
b7643757 3363 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
ca6b0bf0 3364 REG("pagemap", S_IRUGO, proc_pagemap_operations),
28a6d671
EB		 3365#endif
3366#ifdef CONFIG_SECURITY
631f9c18 3367 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 3368#endif
3369#ifdef CONFIG_KALLSYMS
631f9c18 3370 INF("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 3371#endif
2ec220e2 3372#ifdef CONFIG_STACKTRACE
a9712bc1 3373 ONE("stack", S_IRUGO, proc_pid_stack),
28a6d671
EB		 3374#endif
3375#ifdef CONFIG_SCHEDSTATS
631f9c18 3376 INF("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 3377#endif
9745512c 3378#ifdef CONFIG_LATENCYTOP
631f9c18 3379 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 3380#endif
8793d854 3381#ifdef CONFIG_PROC_PID_CPUSET
631f9c18 3382 REG("cpuset", S_IRUGO, proc_cpuset_operations),
a424316c
PM		 3383#endif
3384#ifdef CONFIG_CGROUPS
631f9c18 3385 REG("cgroup", S_IRUGO, proc_cgroup_operations),
28a6d671 3386#endif
631f9c18
AD		 3387 INF("oom_score", S_IRUGO, proc_oom_score),
3388 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
a63d83f4 3389 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
28a6d671 3390#ifdef CONFIG_AUDITSYSCALL
631f9c18 3391 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
26ec3c64 3392 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 3393#endif
f4f154fd 3394#ifdef CONFIG_FAULT_INJECTION
631f9c18 3395 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 3396#endif
297c5d92 3397#ifdef CONFIG_TASK_IO_ACCOUNTING
1d1221f3 3398 INF("io", S_IRUSR, proc_tid_io_accounting),
297c5d92 3399#endif
f133ecca
CM		 3400#ifdef CONFIG_HARDWALL
3401 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3402#endif
28a6d671
EB		 3403};
3404
3405static int proc_tid_base_readdir(struct file * filp,
3406 void * dirent, filldir_t filldir)
3407{
3408 return proc_pident_readdir(filp,dirent,filldir,
3409 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3410}
3411
3412static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
7bcd6b0e
EB		 3413 return proc_pident_lookup(dir, dentry,
3414 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 3415}
3416
00977a59 3417static const struct file_operations proc_tid_base_operations = {
28a6d671
EB		 3418 .read = generic_read_dir,
3419 .readdir = proc_tid_base_readdir,
6038f373 3420 .llseek = default_llseek,
28a6d671
EB		 3421};
3422
c5ef1c42 3423static const struct inode_operations proc_tid_base_inode_operations = {
28a6d671
EB		 3424 .lookup = proc_tid_base_lookup,
3425 .getattr = pid_getattr,
3426 .setattr = proc_setattr,
3427};
3428
444ceed8 3429static struct dentry *proc_task_instantiate(struct inode *dir,
c5141e6d 3430 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8
EB		 3431{
3432 struct dentry *error = ERR_PTR(-ENOENT);
3433 struct inode *inode;
61a28784 3434 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 3435
3436 if (!inode)
3437 goto out;
3438 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3439 inode->i_op = &proc_tid_base_inode_operations;
3440 inode->i_fop = &proc_tid_base_operations;
3441 inode->i_flags|=S_IMMUTABLE;
aed54175 3442
bfe86848
MS		 3443 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3444 ARRAY_SIZE(tid_base_stuff)));
444ceed8 3445
fb045adb 3446 d_set_d_op(dentry, &pid_dentry_operations);
444ceed8
EB		 3447
3448 d_add(dentry, inode);
3449 /* Close the race of the process dying before we return the dentry */
3450 if (pid_revalidate(dentry, NULL))
3451 error = NULL;
3452out:
3453 return error;
3454}
3455
28a6d671
EB		 3456static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3457{
3458 struct dentry *result = ERR_PTR(-ENOENT);
3459 struct task_struct *task;
3460 struct task_struct *leader = get_proc_task(dir);
28a6d671 3461 unsigned tid;
b488893a 3462 struct pid_namespace *ns;
28a6d671
EB		 3463
3464 if (!leader)
3465 goto out_no_task;
3466
3467 tid = name_to_int(dentry);
3468 if (tid == ~0U)
3469 goto out;
3470
b488893a 3471 ns = dentry->d_sb->s_fs_info;
28a6d671 3472 rcu_read_lock();
b488893a 3473 task = find_task_by_pid_ns(tid, ns);
28a6d671
EB		 3474 if (task)
3475 get_task_struct(task);
3476 rcu_read_unlock();
3477 if (!task)
3478 goto out;
bac0abd6 3479 if (!same_thread_group(leader, task))
28a6d671
EB		 3480 goto out_drop_task;
3481
444ceed8 3482 result = proc_task_instantiate(dir, dentry, task, NULL);
28a6d671
EB		 3483out_drop_task:
3484 put_task_struct(task);
3485out:
3486 put_task_struct(leader);
3487out_no_task:
3488 return result;
3489}
3490
0bc58a91
EB		 3491/*
3492 * Find the first tid of a thread group to return to user space.
3493 *
3494 * Usually this is just the thread group leader, but if the users
3495 * buffer was too small or there was a seek into the middle of the
3496 * directory we have more work todo.
3497 *
3498 * In the case of a short read we start with find_task_by_pid.
3499 *
3500 * In the case of a seek we start with the leader and walk nr
3501 * threads past it.
3502 */
cc288738 3503static struct task_struct *first_tid(struct task_struct *leader,
b488893a 3504 int tid, int nr, struct pid_namespace *ns)
0bc58a91 3505{
a872ff0c 3506 struct task_struct *pos;
1da177e4 3507
cc288738 3508 rcu_read_lock();
0bc58a91
EB		 3509 /* Attempt to start with the pid of a thread */
3510 if (tid && (nr > 0)) {
b488893a 3511 pos = find_task_by_pid_ns(tid, ns);
a872ff0c
ON		 3512 if (pos && (pos->group_leader == leader))
3513 goto found;
0bc58a91 3514 }
1da177e4 3515
0bc58a91 3516 /* If nr exceeds the number of threads there is nothing todo */
a872ff0c
ON		 3517 pos = NULL;
3518 if (nr && nr >= get_nr_threads(leader))
3519 goto out;
1da177e4 3520
a872ff0c
ON		 3521 /* If we haven't found our starting place yet start
3522 * with the leader and walk nr threads forward.
0bc58a91 3523 */
a872ff0c
ON		 3524 for (pos = leader; nr > 0; --nr) {
3525 pos = next_thread(pos);
3526 if (pos == leader) {
3527 pos = NULL;
3528 goto out;
3529 }
1da177e4 3530 }
a872ff0c
ON		 3531found:
3532 get_task_struct(pos);
3533out:
cc288738 3534 rcu_read_unlock();
0bc58a91
EB		 3535 return pos;
3536}
3537
3538/*
3539 * Find the next thread in the thread list.
3540 * Return NULL if there is an error or no next thread.
3541 *
3542 * The reference to the input task_struct is released.
3543 */
3544static struct task_struct *next_tid(struct task_struct *start)
3545{
c1df7fb8 3546 struct task_struct *pos = NULL;
cc288738 3547 rcu_read_lock();
c1df7fb8 3548 if (pid_alive(start)) {
0bc58a91 3549 pos = next_thread(start);
c1df7fb8
ON		 3550 if (thread_group_leader(pos))
3551 pos = NULL;
3552 else
3553 get_task_struct(pos);
3554 }
cc288738 3555 rcu_read_unlock();
0bc58a91
EB		 3556 put_task_struct(start);
3557 return pos;
1da177e4
LT		 3558}
3559
61a28784
EB		 3560static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3561 struct task_struct *task, int tid)
3562{
3563 char name[PROC_NUMBUF];
3564 int len = snprintf(name, sizeof(name), "%d", tid);
3565 return proc_fill_cache(filp, dirent, filldir, name, len,
3566 proc_task_instantiate, task, NULL);
3567}
3568
1da177e4
LT		 3569/* for the /proc/TGID/task/ directories */
3570static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3571{
2fddfeef 3572 struct dentry *dentry = filp->f_path.dentry;
1da177e4 3573 struct inode *inode = dentry->d_inode;
7d895244 3574 struct task_struct *leader = NULL;
0bc58a91 3575 struct task_struct *task;
1da177e4
LT		 3576 int retval = -ENOENT;
3577 ino_t ino;
0bc58a91 3578 int tid;
b488893a 3579 struct pid_namespace *ns;
1da177e4 3580
7d895244
GC		 3581 task = get_proc_task(inode);
3582 if (!task)
3583 goto out_no_task;
3584 rcu_read_lock();
3585 if (pid_alive(task)) {
3586 leader = task->group_leader;
3587 get_task_struct(leader);
3588 }
3589 rcu_read_unlock();
3590 put_task_struct(task);
99f89551
EB		 3591 if (!leader)
3592 goto out_no_task;
1da177e4
LT		 3593 retval = 0;
3594
ee568b25 3595 switch ((unsigned long)filp->f_pos) {
1da177e4
LT		 3596 case 0:
3597 ino = inode->i_ino;
ee6f779b 3598 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
1da177e4 3599 goto out;
ee6f779b 3600 filp->f_pos++;
1da177e4
LT		 3601 /* fall through */
3602 case 1:
3603 ino = parent_ino(dentry);
ee6f779b 3604 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
1da177e4 3605 goto out;
ee6f779b 3606 filp->f_pos++;
1da177e4
LT		 3607 /* fall through */
3608 }
3609
0bc58a91
EB		 3610 /* f_version caches the tgid value that the last readdir call couldn't
3611 * return. lseek aka telldir automagically resets f_version to 0.
3612 */
b488893a 3613 ns = filp->f_dentry->d_sb->s_fs_info;
2b47c361 3614 tid = (int)filp->f_version;
0bc58a91 3615 filp->f_version = 0;
ee6f779b 3616 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
0bc58a91 3617 task;
ee6f779b 3618 task = next_tid(task), filp->f_pos++) {
b488893a 3619 tid = task_pid_nr_ns(task, ns);
61a28784 3620 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
0bc58a91
EB		 3621 /* returning this tgid failed, save it as the first
3622 * pid for the next readir call */
2b47c361 3623 filp->f_version = (u64)tid;
0bc58a91 3624 put_task_struct(task);
1da177e4 3625 break;
0bc58a91 3626 }
1da177e4
LT		 3627 }
3628out:
99f89551
EB		 3629 put_task_struct(leader);
3630out_no_task:
1da177e4
LT		 3631 return retval;
3632}
6e66b52b
EB		 3633
3634static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3635{
3636 struct inode *inode = dentry->d_inode;
99f89551 3637 struct task_struct *p = get_proc_task(inode);
6e66b52b
EB		 3638 generic_fillattr(inode, stat);
3639
99f89551 3640 if (p) {
99f89551 3641 stat->nlink += get_nr_threads(p);
99f89551 3642 put_task_struct(p);
6e66b52b
EB		 3643 }
3644
3645 return 0;
3646}
28a6d671 3647
c5ef1c42 3648static const struct inode_operations proc_task_inode_operations = {
28a6d671
EB		 3649 .lookup = proc_task_lookup,
3650 .getattr = proc_task_getattr,
3651 .setattr = proc_setattr,
0499680a 3652 .permission = proc_pid_permission,
28a6d671
EB		 3653};
3654
00977a59 3655static const struct file_operations proc_task_operations = {
28a6d671
EB		 3656 .read = generic_read_dir,
3657 .readdir = proc_task_readdir,
6038f373 3658 .llseek = default_llseek,
28a6d671 3659};
Linux 6.x block layer and io_uring tree(s)