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remove inode_setattr
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / proc / base.c
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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>
b835996f 66#include <linux/rcupdate.h>
1da177e4 67#include <linux/kallsyms.h>
2ec220e2 68#include <linux/stacktrace.h>
d85f50d5 69#include <linux/resource.h>
5096add8 70#include <linux/module.h>
1da177e4
LT		 71#include <linux/mount.h>
72#include <linux/security.h>
73#include <linux/ptrace.h>
0d094efe 74#include <linux/tracehook.h>
a424316c 75#include <linux/cgroup.h>
1da177e4
LT		 76#include <linux/cpuset.h>
77#include <linux/audit.h>
5addc5dd 78#include <linux/poll.h>
1651e14e 79#include <linux/nsproxy.h>
8ac773b4 80#include <linux/oom.h>
3cb4a0bb 81#include <linux/elf.h>
60347f67 82#include <linux/pid_namespace.h>
5ad4e53b 83#include <linux/fs_struct.h>
5a0e3ad6 84#include <linux/slab.h>
1da177e4
LT		 85#include "internal.h"
86
0f2fe20f
EB		 87/* NOTE:
88 * Implementing inode permission operations in /proc is almost
89 * certainly an error. Permission checks need to happen during
90 * each system call not at open time. The reason is that most of
91 * what we wish to check for permissions in /proc varies at runtime.
92 *
93 * The classic example of a problem is opening file descriptors
94 * in /proc for a task before it execs a suid executable.
95 */
96
1da177e4 97struct pid_entry {
1da177e4 98 char *name;
c5141e6d 99 int len;
1da177e4 100 mode_t mode;
c5ef1c42 101 const struct inode_operations *iop;
00977a59 102 const struct file_operations *fop;
20cdc894 103 union proc_op op;
1da177e4
LT		 104};
105
61a28784 106#define NOD(NAME, MODE, IOP, FOP, OP) { \
20cdc894 107 .name = (NAME), \
c5141e6d 108 .len = sizeof(NAME) - 1, \
20cdc894
EB		 109 .mode = MODE, \
110 .iop = IOP, \
111 .fop = FOP, \
112 .op = OP, \
113}
114
631f9c18
AD		 115#define DIR(NAME, MODE, iops, fops) \
116 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
117#define LNK(NAME, get_link) \
61a28784 118 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
20cdc894 119 &proc_pid_link_inode_operations, NULL, \
631f9c18
AD		 120 { .proc_get_link = get_link } )
121#define REG(NAME, MODE, fops) \
122 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
123#define INF(NAME, MODE, read) \
61a28784 124 NOD(NAME, (S_IFREG|(MODE)), \
20cdc894 125 NULL, &proc_info_file_operations, \
631f9c18
AD		 126 { .proc_read = read } )
127#define ONE(NAME, MODE, show) \
be614086
EB		 128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_single_file_operations, \
631f9c18 130 { .proc_show = show } )
1da177e4 131
aed54175
VN		 132/*
133 * Count the number of hardlinks for the pid_entry table, excluding the .
134 * and .. links.
135 */
136static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
137 unsigned int n)
138{
139 unsigned int i;
140 unsigned int count;
141
142 count = 0;
143 for (i = 0; i < n; ++i) {
144 if (S_ISDIR(entries[i].mode))
145 ++count;
146 }
147
148 return count;
149}
150
7c2c7d99 151static int get_fs_path(struct task_struct *task, struct path *path, bool root)
1da177e4
LT		 152{
153 struct fs_struct *fs;
7c2c7d99
HD		 154 int result = -ENOENT;
155
0494f6ec
MS		 156 task_lock(task);
157 fs = task->fs;
7c2c7d99
HD		 158 if (fs) {
159 read_lock(&fs->lock);
160 *path = root ? fs->root : fs->pwd;
161 path_get(path);
162 read_unlock(&fs->lock);
163 result = 0;
164 }
0494f6ec 165 task_unlock(task);
7c2c7d99 166 return result;
0494f6ec
MS		 167}
168
3dcd25f3 169static int proc_cwd_link(struct inode *inode, struct path *path)
0494f6ec 170{
99f89551 171 struct task_struct *task = get_proc_task(inode);
0494f6ec 172 int result = -ENOENT;
99f89551
EB		 173
174 if (task) {
7c2c7d99 175 result = get_fs_path(task, path, 0);
99f89551
EB		 176 put_task_struct(task);
177 }
1da177e4
LT		 178 return result;
179}
180
3dcd25f3 181static int proc_root_link(struct inode *inode, struct path *path)
1da177e4 182{
99f89551 183 struct task_struct *task = get_proc_task(inode);
1da177e4 184 int result = -ENOENT;
99f89551
EB		 185
186 if (task) {
7c2c7d99 187 result = get_fs_path(task, path, 1);
99f89551
EB		 188 put_task_struct(task);
189 }
1da177e4
LT		 190 return result;
191}
192
638fa202
RM		 193/*
194 * Return zero if current may access user memory in @task, -error if not.
195 */
196static int check_mem_permission(struct task_struct *task)
197{
198 /*
199 * A task can always look at itself, in case it chooses
200 * to use system calls instead of load instructions.
201 */
202 if (task == current)
203 return 0;
204
205 /*
206 * If current is actively ptrace'ing, and would also be
207 * permitted to freshly attach with ptrace now, permit it.
208 */
0d094efe
RM		 209 if (task_is_stopped_or_traced(task)) {
210 int match;
211 rcu_read_lock();
212 match = (tracehook_tracer_task(task) == current);
213 rcu_read_unlock();
214 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
215 return 0;
216 }
638fa202
RM		 217
218 /*
219 * Noone else is allowed.
220 */
221 return -EPERM;
222}
1da177e4 223
831830b5
AV		 224struct mm_struct *mm_for_maps(struct task_struct *task)
225{
704b836c
ON		 226 struct mm_struct *mm;
227
228 if (mutex_lock_killable(&task->cred_guard_mutex))
229 return NULL;
00f89d21 230
704b836c
ON		 231 mm = get_task_mm(task);
232 if (mm && mm != current->mm &&
233 !ptrace_may_access(task, PTRACE_MODE_READ)) {
234 mmput(mm);
235 mm = NULL;
13f0feaf 236 }
704b836c
ON		 237 mutex_unlock(&task->cred_guard_mutex);
238
831830b5 239 return mm;
831830b5
AV		 240}
241
1da177e4
LT		 242static int proc_pid_cmdline(struct task_struct *task, char * buffer)
243{
244 int res = 0;
245 unsigned int len;
246 struct mm_struct *mm = get_task_mm(task);
247 if (!mm)
248 goto out;
249 if (!mm->arg_end)
250 goto out_mm; /* Shh! No looking before we're done */
251
252 len = mm->arg_end - mm->arg_start;
253
254 if (len > PAGE_SIZE)
255 len = PAGE_SIZE;
256
257 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
258
259 // If the nul at the end of args has been overwritten, then
260 // assume application is using setproctitle(3).
261 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
262 len = strnlen(buffer, res);
263 if (len < res) {
264 res = len;
265 } else {
266 len = mm->env_end - mm->env_start;
267 if (len > PAGE_SIZE - res)
268 len = PAGE_SIZE - res;
269 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
270 res = strnlen(buffer, res);
271 }
272 }
273out_mm:
274 mmput(mm);
275out:
276 return res;
277}
278
279static int proc_pid_auxv(struct task_struct *task, char *buffer)
280{
281 int res = 0;
282 struct mm_struct *mm = get_task_mm(task);
283 if (mm) {
284 unsigned int nwords = 0;
dfe6b7d9 285 do {
1da177e4 286 nwords += 2;
dfe6b7d9 287 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1da177e4
LT		 288 res = nwords * sizeof(mm->saved_auxv[0]);
289 if (res > PAGE_SIZE)
290 res = PAGE_SIZE;
291 memcpy(buffer, mm->saved_auxv, res);
292 mmput(mm);
293 }
294 return res;
295}
296
297
298#ifdef CONFIG_KALLSYMS
299/*
300 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
301 * Returns the resolved symbol. If that fails, simply return the address.
302 */
303static int proc_pid_wchan(struct task_struct *task, char *buffer)
304{
ffb45122 305 unsigned long wchan;
9281acea 306 char symname[KSYM_NAME_LEN];
1da177e4
LT		 307
308 wchan = get_wchan(task);
309
9d65cb4a 310 if (lookup_symbol_name(wchan, symname) < 0)
f83ce3e6
JE		 311 if (!ptrace_may_access(task, PTRACE_MODE_READ))
312 return 0;
313 else
314 return sprintf(buffer, "%lu", wchan);
9d65cb4a
AD		 315 else
316 return sprintf(buffer, "%s", symname);
1da177e4
LT		 317}
318#endif /* CONFIG_KALLSYMS */
319
2ec220e2
KC		 320#ifdef CONFIG_STACKTRACE
321
322#define MAX_STACK_TRACE_DEPTH 64
323
324static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
325 struct pid *pid, struct task_struct *task)
326{
327 struct stack_trace trace;
328 unsigned long *entries;
329 int i;
330
331 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
332 if (!entries)
333 return -ENOMEM;
334
335 trace.nr_entries = 0;
336 trace.max_entries = MAX_STACK_TRACE_DEPTH;
337 trace.entries = entries;
338 trace.skip = 0;
339 save_stack_trace_tsk(task, &trace);
340
341 for (i = 0; i < trace.nr_entries; i++) {
342 seq_printf(m, "[<%p>] %pS\n",
343 (void *)entries[i], (void *)entries[i]);
344 }
345 kfree(entries);
346
347 return 0;
348}
349#endif
350
1da177e4
LT		 351#ifdef CONFIG_SCHEDSTATS
352/*
353 * Provides /proc/PID/schedstat
354 */
355static int proc_pid_schedstat(struct task_struct *task, char *buffer)
356{
172ba844 357 return sprintf(buffer, "%llu %llu %lu\n",
826e08b0
IM		 358 (unsigned long long)task->se.sum_exec_runtime,
359 (unsigned long long)task->sched_info.run_delay,
2d72376b 360 task->sched_info.pcount);
1da177e4
LT		 361}
362#endif
363
9745512c
AV		 364#ifdef CONFIG_LATENCYTOP
365static int lstats_show_proc(struct seq_file *m, void *v)
366{
367 int i;
13d77c37
HS		 368 struct inode *inode = m->private;
369 struct task_struct *task = get_proc_task(inode);
9745512c 370
13d77c37
HS		 371 if (!task)
372 return -ESRCH;
373 seq_puts(m, "Latency Top version : v0.1\n");
9745512c
AV		 374 for (i = 0; i < 32; i++) {
375 if (task->latency_record[i].backtrace[0]) {
376 int q;
377 seq_printf(m, "%i %li %li ",
378 task->latency_record[i].count,
379 task->latency_record[i].time,
380 task->latency_record[i].max);
381 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
9c246247 382 char sym[KSYM_SYMBOL_LEN];
9745512c
AV		 383 char *c;
384 if (!task->latency_record[i].backtrace[q])
385 break;
386 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
387 break;
388 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
389 c = strchr(sym, '+');
390 if (c)
391 *c = 0;
392 seq_printf(m, "%s ", sym);
393 }
394 seq_printf(m, "\n");
395 }
396
397 }
13d77c37 398 put_task_struct(task);
9745512c
AV		 399 return 0;
400}
401
402static int lstats_open(struct inode *inode, struct file *file)
403{
13d77c37 404 return single_open(file, lstats_show_proc, inode);
d6643d12
HS		 405}
406
9745512c
AV		 407static ssize_t lstats_write(struct file *file, const char __user *buf,
408 size_t count, loff_t *offs)
409{
13d77c37 410 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
9745512c 411
13d77c37
HS		 412 if (!task)
413 return -ESRCH;
9745512c 414 clear_all_latency_tracing(task);
13d77c37 415 put_task_struct(task);
9745512c
AV		 416
417 return count;
418}
419
420static const struct file_operations proc_lstats_operations = {
421 .open = lstats_open,
422 .read = seq_read,
423 .write = lstats_write,
424 .llseek = seq_lseek,
13d77c37 425 .release = single_release,
9745512c
AV		 426};
427
428#endif
429
1da177e4
LT		 430/* The badness from the OOM killer */
431unsigned long badness(struct task_struct *p, unsigned long uptime);
432static int proc_oom_score(struct task_struct *task, char *buffer)
433{
b95c35e7 434 unsigned long points = 0;
1da177e4
LT		 435 struct timespec uptime;
436
437 do_posix_clock_monotonic_gettime(&uptime);
19c5d45a 438 read_lock(&tasklist_lock);
b95c35e7
ON		 439 if (pid_alive(task))
440 points = badness(task, uptime.tv_sec);
19c5d45a 441 read_unlock(&tasklist_lock);
1da177e4
LT		 442 return sprintf(buffer, "%lu\n", points);
443}
444
d85f50d5
NH		 445struct limit_names {
446 char *name;
447 char *unit;
448};
449
450static const struct limit_names lnames[RLIM_NLIMITS] = {
cff4edb5 451 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
d85f50d5
NH		 452 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
453 [RLIMIT_DATA] = {"Max data size", "bytes"},
454 [RLIMIT_STACK] = {"Max stack size", "bytes"},
455 [RLIMIT_CORE] = {"Max core file size", "bytes"},
456 [RLIMIT_RSS] = {"Max resident set", "bytes"},
457 [RLIMIT_NPROC] = {"Max processes", "processes"},
458 [RLIMIT_NOFILE] = {"Max open files", "files"},
459 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
460 [RLIMIT_AS] = {"Max address space", "bytes"},
461 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
462 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
463 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
464 [RLIMIT_NICE] = {"Max nice priority", NULL},
465 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
8808117c 466 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
d85f50d5
NH		 467};
468
469/* Display limits for a process */
470static int proc_pid_limits(struct task_struct *task, char *buffer)
471{
472 unsigned int i;
473 int count = 0;
474 unsigned long flags;
475 char *bufptr = buffer;
476
477 struct rlimit rlim[RLIM_NLIMITS];
478
a6bebbc8 479 if (!lock_task_sighand(task, &flags))
d85f50d5 480 return 0;
d85f50d5
NH		 481 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
482 unlock_task_sighand(task, &flags);
d85f50d5
NH		 483
484 /*
485 * print the file header
486 */
487 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
488 "Limit", "Soft Limit", "Hard Limit", "Units");
489
490 for (i = 0; i < RLIM_NLIMITS; i++) {
491 if (rlim[i].rlim_cur == RLIM_INFINITY)
492 count += sprintf(&bufptr[count], "%-25s %-20s ",
493 lnames[i].name, "unlimited");
494 else
495 count += sprintf(&bufptr[count], "%-25s %-20lu ",
496 lnames[i].name, rlim[i].rlim_cur);
497
498 if (rlim[i].rlim_max == RLIM_INFINITY)
499 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
500 else
501 count += sprintf(&bufptr[count], "%-20lu ",
502 rlim[i].rlim_max);
503
504 if (lnames[i].unit)
505 count += sprintf(&bufptr[count], "%-10s\n",
506 lnames[i].unit);
507 else
508 count += sprintf(&bufptr[count], "\n");
509 }
510
511 return count;
512}
513
ebcb6734
RM		 514#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
515static int proc_pid_syscall(struct task_struct *task, char *buffer)
516{
517 long nr;
518 unsigned long args[6], sp, pc;
519
520 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
521 return sprintf(buffer, "running\n");
522
523 if (nr < 0)
524 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
525
526 return sprintf(buffer,
527 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
528 nr,
529 args[0], args[1], args[2], args[3], args[4], args[5],
530 sp, pc);
531}
532#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
533
1da177e4
LT		 534/************************************************************************/
535/* Here the fs part begins */
536/************************************************************************/
537
538/* permission checks */
778c1144 539static int proc_fd_access_allowed(struct inode *inode)
1da177e4 540{
778c1144
EB		 541 struct task_struct *task;
542 int allowed = 0;
df26c40e
EB		 543 /* Allow access to a task's file descriptors if it is us or we
544 * may use ptrace attach to the process and find out that
545 * information.
778c1144
EB		 546 */
547 task = get_proc_task(inode);
df26c40e 548 if (task) {
006ebb40 549 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
778c1144 550 put_task_struct(task);
df26c40e 551 }
778c1144 552 return allowed;
1da177e4
LT		 553}
554
6d76fa58
LT		 555static int proc_setattr(struct dentry *dentry, struct iattr *attr)
556{
557 int error;
558 struct inode *inode = dentry->d_inode;
559
560 if (attr->ia_valid & ATTR_MODE)
561 return -EPERM;
562
563 error = inode_change_ok(inode, attr);
1025774c
CH		 564 if (error)
565 return error;
566
567 if ((attr->ia_valid & ATTR_SIZE) &&
568 attr->ia_size != i_size_read(inode)) {
569 error = vmtruncate(inode, attr->ia_size);
570 if (error)
571 return error;
572 }
573
574 setattr_copy(inode, attr);
575 mark_inode_dirty(inode);
576 return 0;
6d76fa58
LT		 577}
578
c5ef1c42 579static const struct inode_operations proc_def_inode_operations = {
6d76fa58
LT		 580 .setattr = proc_setattr,
581};
582
a1a2c409
MS		 583static int mounts_open_common(struct inode *inode, struct file *file,
584 const struct seq_operations *op)
1da177e4 585{
99f89551 586 struct task_struct *task = get_proc_task(inode);
cf7b708c 587 struct nsproxy *nsp;
6b3286ed 588 struct mnt_namespace *ns = NULL;
a1a2c409 589 struct path root;
5addc5dd
AV		 590 struct proc_mounts *p;
591 int ret = -EINVAL;
1da177e4 592
99f89551 593 if (task) {
cf7b708c
PE		 594 rcu_read_lock();
595 nsp = task_nsproxy(task);
596 if (nsp) {
597 ns = nsp->mnt_ns;
863c4702
AD		 598 if (ns)
599 get_mnt_ns(ns);
600 }
cf7b708c 601 rcu_read_unlock();
7c2c7d99
HD		 602 if (ns && get_fs_path(task, &root, 1) == 0)
603 ret = 0;
99f89551
EB		 604 put_task_struct(task);
605 }
5addc5dd 606
a1a2c409
MS		 607 if (!ns)
608 goto err;
7c2c7d99 609 if (ret)
a1a2c409
MS		 610 goto err_put_ns;
611
a1a2c409
MS		 612 ret = -ENOMEM;
613 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
614 if (!p)
615 goto err_put_path;
616
617 file->private_data = &p->m;
618 ret = seq_open(file, op);
619 if (ret)
620 goto err_free;
621
622 p->m.private = p;
623 p->ns = ns;
624 p->root = root;
625 p->event = ns->event;
626
627 return 0;
628
629 err_free:
630 kfree(p);
631 err_put_path:
632 path_put(&root);
633 err_put_ns:
634 put_mnt_ns(ns);
635 err:
1da177e4
LT		 636 return ret;
637}
638
639static int mounts_release(struct inode *inode, struct file *file)
640{
a1a2c409
MS		 641 struct proc_mounts *p = file->private_data;
642 path_put(&p->root);
643 put_mnt_ns(p->ns);
1da177e4
LT		 644 return seq_release(inode, file);
645}
646
5addc5dd
AV		 647static unsigned mounts_poll(struct file *file, poll_table *wait)
648{
649 struct proc_mounts *p = file->private_data;
31b07093 650 unsigned res = POLLIN | POLLRDNORM;
5addc5dd 651
9f5596af
AV		 652 poll_wait(file, &p->ns->poll, wait);
653 if (mnt_had_events(p))
31b07093 654 res |= POLLERR | POLLPRI;
5addc5dd
AV		 655
656 return res;
657}
658
a1a2c409
MS		 659static int mounts_open(struct inode *inode, struct file *file)
660{
661 return mounts_open_common(inode, file, &mounts_op);
662}
663
00977a59 664static const struct file_operations proc_mounts_operations = {
1da177e4
LT		 665 .open = mounts_open,
666 .read = seq_read,
667 .llseek = seq_lseek,
668 .release = mounts_release,
5addc5dd 669 .poll = mounts_poll,
1da177e4
LT		 670};
671
2d4d4864
RP		 672static int mountinfo_open(struct inode *inode, struct file *file)
673{
674 return mounts_open_common(inode, file, &mountinfo_op);
675}
676
677static const struct file_operations proc_mountinfo_operations = {
678 .open = mountinfo_open,
679 .read = seq_read,
680 .llseek = seq_lseek,
681 .release = mounts_release,
682 .poll = mounts_poll,
683};
684
b4629fe2
CL		 685static int mountstats_open(struct inode *inode, struct file *file)
686{
a1a2c409 687 return mounts_open_common(inode, file, &mountstats_op);
b4629fe2
CL		 688}
689
00977a59 690static const struct file_operations proc_mountstats_operations = {
b4629fe2
CL		 691 .open = mountstats_open,
692 .read = seq_read,
693 .llseek = seq_lseek,
694 .release = mounts_release,
695};
696
1da177e4
LT		 697#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
698
699static ssize_t proc_info_read(struct file * file, char __user * buf,
700 size_t count, loff_t *ppos)
701{
2fddfeef 702 struct inode * inode = file->f_path.dentry->d_inode;
1da177e4
LT		 703 unsigned long page;
704 ssize_t length;
99f89551
EB		 705 struct task_struct *task = get_proc_task(inode);
706
707 length = -ESRCH;
708 if (!task)
709 goto out_no_task;
1da177e4
LT		 710
711 if (count > PROC_BLOCK_SIZE)
712 count = PROC_BLOCK_SIZE;
99f89551
EB		 713
714 length = -ENOMEM;
e12ba74d 715 if (!(page = __get_free_page(GFP_TEMPORARY)))
99f89551 716 goto out;
1da177e4
LT		 717
718 length = PROC_I(inode)->op.proc_read(task, (char*)page);
719
720 if (length >= 0)
721 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
722 free_page(page);
99f89551
EB		 723out:
724 put_task_struct(task);
725out_no_task:
1da177e4
LT		 726 return length;
727}
728
00977a59 729static const struct file_operations proc_info_file_operations = {
1da177e4 730 .read = proc_info_read,
87df8424 731 .llseek = generic_file_llseek,
1da177e4
LT		 732};
733
be614086
EB		 734static int proc_single_show(struct seq_file *m, void *v)
735{
736 struct inode *inode = m->private;
737 struct pid_namespace *ns;
738 struct pid *pid;
739 struct task_struct *task;
740 int ret;
741
742 ns = inode->i_sb->s_fs_info;
743 pid = proc_pid(inode);
744 task = get_pid_task(pid, PIDTYPE_PID);
745 if (!task)
746 return -ESRCH;
747
748 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
749
750 put_task_struct(task);
751 return ret;
752}
753
754static int proc_single_open(struct inode *inode, struct file *filp)
755{
756 int ret;
757 ret = single_open(filp, proc_single_show, NULL);
758 if (!ret) {
759 struct seq_file *m = filp->private_data;
760
761 m->private = inode;
762 }
763 return ret;
764}
765
766static const struct file_operations proc_single_file_operations = {
767 .open = proc_single_open,
768 .read = seq_read,
769 .llseek = seq_lseek,
770 .release = single_release,
771};
772
1da177e4
LT		 773static int mem_open(struct inode* inode, struct file* file)
774{
775 file->private_data = (void*)((long)current->self_exec_id);
776 return 0;
777}
778
779static ssize_t mem_read(struct file * file, char __user * buf,
780 size_t count, loff_t *ppos)
781{
2fddfeef 782 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1da177e4
LT		 783 char *page;
784 unsigned long src = *ppos;
785 int ret = -ESRCH;
786 struct mm_struct *mm;
787
99f89551
EB		 788 if (!task)
789 goto out_no_task;
790
638fa202 791 if (check_mem_permission(task))
1da177e4
LT		 792 goto out;
793
794 ret = -ENOMEM;
e12ba74d 795 page = (char *)__get_free_page(GFP_TEMPORARY);
1da177e4
LT		 796 if (!page)
797 goto out;
798
799 ret = 0;
800
801 mm = get_task_mm(task);
802 if (!mm)
803 goto out_free;
804
805 ret = -EIO;
806
807 if (file->private_data != (void*)((long)current->self_exec_id))
808 goto out_put;
809
810 ret = 0;
811
812 while (count > 0) {
813 int this_len, retval;
814
815 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
816 retval = access_process_vm(task, src, page, this_len, 0);
638fa202 817 if (!retval || check_mem_permission(task)) {
1da177e4
LT		 818 if (!ret)
819 ret = -EIO;
820 break;
821 }
822
823 if (copy_to_user(buf, page, retval)) {
824 ret = -EFAULT;
825 break;
826 }
827
828 ret += retval;
829 src += retval;
830 buf += retval;
831 count -= retval;
832 }
833 *ppos = src;
834
835out_put:
836 mmput(mm);
837out_free:
838 free_page((unsigned long) page);
839out:
99f89551
EB		 840 put_task_struct(task);
841out_no_task:
1da177e4
LT		 842 return ret;
843}
844
845#define mem_write NULL
846
847#ifndef mem_write
848/* This is a security hazard */
63967fa9 849static ssize_t mem_write(struct file * file, const char __user *buf,
1da177e4
LT		 850 size_t count, loff_t *ppos)
851{
f7ca54f4 852 int copied;
1da177e4 853 char *page;
2fddfeef 854 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1da177e4
LT		 855 unsigned long dst = *ppos;
856
99f89551
EB		 857 copied = -ESRCH;
858 if (!task)
859 goto out_no_task;
860
638fa202 861 if (check_mem_permission(task))
99f89551 862 goto out;
1da177e4 863
99f89551 864 copied = -ENOMEM;
e12ba74d 865 page = (char *)__get_free_page(GFP_TEMPORARY);
1da177e4 866 if (!page)
99f89551 867 goto out;
1da177e4 868
f7ca54f4 869 copied = 0;
1da177e4
LT		 870 while (count > 0) {
871 int this_len, retval;
872
873 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
874 if (copy_from_user(page, buf, this_len)) {
875 copied = -EFAULT;
876 break;
877 }
878 retval = access_process_vm(task, dst, page, this_len, 1);
879 if (!retval) {
880 if (!copied)
881 copied = -EIO;
882 break;
883 }
884 copied += retval;
885 buf += retval;
886 dst += retval;
887 count -= retval;
888 }
889 *ppos = dst;
890 free_page((unsigned long) page);
99f89551
EB		 891out:
892 put_task_struct(task);
893out_no_task:
1da177e4
LT		 894 return copied;
895}
896#endif
897
85863e47 898loff_t mem_lseek(struct file *file, loff_t offset, int orig)
1da177e4
LT		 899{
900 switch (orig) {
901 case 0:
902 file->f_pos = offset;
903 break;
904 case 1:
905 file->f_pos += offset;
906 break;
907 default:
908 return -EINVAL;
909 }
910 force_successful_syscall_return();
911 return file->f_pos;
912}
913
00977a59 914static const struct file_operations proc_mem_operations = {
1da177e4
LT		 915 .llseek = mem_lseek,
916 .read = mem_read,
917 .write = mem_write,
918 .open = mem_open,
919};
920
315e28c8
JP		 921static ssize_t environ_read(struct file *file, char __user *buf,
922 size_t count, loff_t *ppos)
923{
924 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
925 char *page;
926 unsigned long src = *ppos;
927 int ret = -ESRCH;
928 struct mm_struct *mm;
929
930 if (!task)
931 goto out_no_task;
932
006ebb40 933 if (!ptrace_may_access(task, PTRACE_MODE_READ))
315e28c8
JP		 934 goto out;
935
936 ret = -ENOMEM;
937 page = (char *)__get_free_page(GFP_TEMPORARY);
938 if (!page)
939 goto out;
940
941 ret = 0;
942
943 mm = get_task_mm(task);
944 if (!mm)
945 goto out_free;
946
947 while (count > 0) {
948 int this_len, retval, max_len;
949
950 this_len = mm->env_end - (mm->env_start + src);
951
952 if (this_len <= 0)
953 break;
954
955 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
956 this_len = (this_len > max_len) ? max_len : this_len;
957
958 retval = access_process_vm(task, (mm->env_start + src),
959 page, this_len, 0);
960
961 if (retval <= 0) {
962 ret = retval;
963 break;
964 }
965
966 if (copy_to_user(buf, page, retval)) {
967 ret = -EFAULT;
968 break;
969 }
970
971 ret += retval;
972 src += retval;
973 buf += retval;
974 count -= retval;
975 }
976 *ppos = src;
977
978 mmput(mm);
979out_free:
980 free_page((unsigned long) page);
981out:
982 put_task_struct(task);
983out_no_task:
984 return ret;
985}
986
987static const struct file_operations proc_environ_operations = {
988 .read = environ_read,
87df8424 989 .llseek = generic_file_llseek,
315e28c8
JP		 990};
991
1da177e4
LT		 992static ssize_t oom_adjust_read(struct file *file, char __user *buf,
993 size_t count, loff_t *ppos)
994{
2fddfeef 995 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
8578cea7 996 char buffer[PROC_NUMBUF];
1da177e4 997 size_t len;
28b83c51
KM		 998 int oom_adjust = OOM_DISABLE;
999 unsigned long flags;
1da177e4 1000
99f89551
EB		 1001 if (!task)
1002 return -ESRCH;
28b83c51
KM		 1003
1004 if (lock_task_sighand(task, &flags)) {
1005 oom_adjust = task->signal->oom_adj;
1006 unlock_task_sighand(task, &flags);
1007 }
1008
99f89551
EB		 1009 put_task_struct(task);
1010
8578cea7 1011 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
0c28f287
AM		 1012
1013 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1da177e4
LT		 1014}
1015
1016static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1017 size_t count, loff_t *ppos)
1018{
99f89551 1019 struct task_struct *task;
5d863b89
KM		 1020 char buffer[PROC_NUMBUF];
1021 long oom_adjust;
28b83c51 1022 unsigned long flags;
5d863b89 1023 int err;
1da177e4 1024
8578cea7
EB		 1025 memset(buffer, 0, sizeof(buffer));
1026 if (count > sizeof(buffer) - 1)
1027 count = sizeof(buffer) - 1;
1da177e4
LT		 1028 if (copy_from_user(buffer, buf, count))
1029 return -EFAULT;
5d863b89
KM		 1030
1031 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1032 if (err)
1033 return -EINVAL;
8ac773b4
AD		 1034 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1035 oom_adjust != OOM_DISABLE)
1da177e4 1036 return -EINVAL;
5d863b89 1037
2fddfeef 1038 task = get_proc_task(file->f_path.dentry->d_inode);
99f89551
EB		 1039 if (!task)
1040 return -ESRCH;
28b83c51
KM		 1041 if (!lock_task_sighand(task, &flags)) {
1042 put_task_struct(task);
1043 return -ESRCH;
1044 }
1045
1046 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1047 unlock_task_sighand(task, &flags);
8fb4fc68
GJ		 1048 put_task_struct(task);
1049 return -EACCES;
1050 }
28b83c51
KM		 1051
1052 task->signal->oom_adj = oom_adjust;
1053
1054 unlock_task_sighand(task, &flags);
99f89551 1055 put_task_struct(task);
5d863b89
KM		 1056
1057 return count;
1da177e4
LT		 1058}
1059
00977a59 1060static const struct file_operations proc_oom_adjust_operations = {
1da177e4
LT		 1061 .read = oom_adjust_read,
1062 .write = oom_adjust_write,
87df8424 1063 .llseek = generic_file_llseek,
1da177e4
LT		 1064};
1065
1da177e4
LT		 1066#ifdef CONFIG_AUDITSYSCALL
1067#define TMPBUFLEN 21
1068static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1069 size_t count, loff_t *ppos)
1070{
2fddfeef 1071 struct inode * inode = file->f_path.dentry->d_inode;
99f89551 1072 struct task_struct *task = get_proc_task(inode);
1da177e4
LT		 1073 ssize_t length;
1074 char tmpbuf[TMPBUFLEN];
1075
99f89551
EB		 1076 if (!task)
1077 return -ESRCH;
1da177e4 1078 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
0c11b942 1079 audit_get_loginuid(task));
99f89551 1080 put_task_struct(task);
1da177e4
LT		 1081 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1082}
1083
1084static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1085 size_t count, loff_t *ppos)
1086{
2fddfeef 1087 struct inode * inode = file->f_path.dentry->d_inode;
1da177e4
LT		 1088 char *page, *tmp;
1089 ssize_t length;
1da177e4
LT		 1090 uid_t loginuid;
1091
1092 if (!capable(CAP_AUDIT_CONTROL))
1093 return -EPERM;
1094
7dc52157
PM		 1095 rcu_read_lock();
1096 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1097 rcu_read_unlock();
1da177e4 1098 return -EPERM;
7dc52157
PM		 1099 }
1100 rcu_read_unlock();
1da177e4 1101
e0182909
AV		 1102 if (count >= PAGE_SIZE)
1103 count = PAGE_SIZE - 1;
1da177e4
LT		 1104
1105 if (*ppos != 0) {
1106 /* No partial writes. */
1107 return -EINVAL;
1108 }
e12ba74d 1109 page = (char*)__get_free_page(GFP_TEMPORARY);
1da177e4
LT		 1110 if (!page)
1111 return -ENOMEM;
1112 length = -EFAULT;
1113 if (copy_from_user(page, buf, count))
1114 goto out_free_page;
1115
e0182909 1116 page[count] = '\0';
1da177e4
LT		 1117 loginuid = simple_strtoul(page, &tmp, 10);
1118 if (tmp == page) {
1119 length = -EINVAL;
1120 goto out_free_page;
1121
1122 }
99f89551 1123 length = audit_set_loginuid(current, loginuid);
1da177e4
LT		 1124 if (likely(length == 0))
1125 length = count;
1126
1127out_free_page:
1128 free_page((unsigned long) page);
1129 return length;
1130}
1131
00977a59 1132static const struct file_operations proc_loginuid_operations = {
1da177e4
LT		 1133 .read = proc_loginuid_read,
1134 .write = proc_loginuid_write,
87df8424 1135 .llseek = generic_file_llseek,
1da177e4 1136};
1e0bd755
EP		 1137
1138static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1139 size_t count, loff_t *ppos)
1140{
1141 struct inode * inode = file->f_path.dentry->d_inode;
1142 struct task_struct *task = get_proc_task(inode);
1143 ssize_t length;
1144 char tmpbuf[TMPBUFLEN];
1145
1146 if (!task)
1147 return -ESRCH;
1148 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1149 audit_get_sessionid(task));
1150 put_task_struct(task);
1151 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1152}
1153
1154static const struct file_operations proc_sessionid_operations = {
1155 .read = proc_sessionid_read,
87df8424 1156 .llseek = generic_file_llseek,
1e0bd755 1157};
1da177e4
LT		 1158#endif
1159
f4f154fd
AM		 1160#ifdef CONFIG_FAULT_INJECTION
1161static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1162 size_t count, loff_t *ppos)
1163{
1164 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1165 char buffer[PROC_NUMBUF];
1166 size_t len;
1167 int make_it_fail;
f4f154fd
AM		 1168
1169 if (!task)
1170 return -ESRCH;
1171 make_it_fail = task->make_it_fail;
1172 put_task_struct(task);
1173
1174 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
0c28f287
AM		 1175
1176 return simple_read_from_buffer(buf, count, ppos, buffer, len);
f4f154fd
AM		 1177}
1178
1179static ssize_t proc_fault_inject_write(struct file * file,
1180 const char __user * buf, size_t count, loff_t *ppos)
1181{
1182 struct task_struct *task;
1183 char buffer[PROC_NUMBUF], *end;
1184 int make_it_fail;
1185
1186 if (!capable(CAP_SYS_RESOURCE))
1187 return -EPERM;
1188 memset(buffer, 0, sizeof(buffer));
1189 if (count > sizeof(buffer) - 1)
1190 count = sizeof(buffer) - 1;
1191 if (copy_from_user(buffer, buf, count))
1192 return -EFAULT;
cba8aafe
VL		 1193 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1194 if (*end)
1195 return -EINVAL;
f4f154fd
AM		 1196 task = get_proc_task(file->f_dentry->d_inode);
1197 if (!task)
1198 return -ESRCH;
1199 task->make_it_fail = make_it_fail;
1200 put_task_struct(task);
cba8aafe
VL		 1201
1202 return count;
f4f154fd
AM		 1203}
1204
00977a59 1205static const struct file_operations proc_fault_inject_operations = {
f4f154fd
AM		 1206 .read = proc_fault_inject_read,
1207 .write = proc_fault_inject_write,
87df8424 1208 .llseek = generic_file_llseek,
f4f154fd
AM		 1209};
1210#endif
1211
9745512c 1212
43ae34cb
IM		 1213#ifdef CONFIG_SCHED_DEBUG
1214/*
1215 * Print out various scheduling related per-task fields:
1216 */
1217static int sched_show(struct seq_file *m, void *v)
1218{
1219 struct inode *inode = m->private;
1220 struct task_struct *p;
1221
43ae34cb
IM		 1222 p = get_proc_task(inode);
1223 if (!p)
1224 return -ESRCH;
1225 proc_sched_show_task(p, m);
1226
1227 put_task_struct(p);
1228
1229 return 0;
1230}
1231
1232static ssize_t
1233sched_write(struct file *file, const char __user *buf,
1234 size_t count, loff_t *offset)
1235{
1236 struct inode *inode = file->f_path.dentry->d_inode;
1237 struct task_struct *p;
1238
43ae34cb
IM		 1239 p = get_proc_task(inode);
1240 if (!p)
1241 return -ESRCH;
1242 proc_sched_set_task(p);
1243
1244 put_task_struct(p);
1245
1246 return count;
1247}
1248
1249static int sched_open(struct inode *inode, struct file *filp)
1250{
1251 int ret;
1252
1253 ret = single_open(filp, sched_show, NULL);
1254 if (!ret) {
1255 struct seq_file *m = filp->private_data;
1256
1257 m->private = inode;
1258 }
1259 return ret;
1260}
1261
1262static const struct file_operations proc_pid_sched_operations = {
1263 .open = sched_open,
1264 .read = seq_read,
1265 .write = sched_write,
1266 .llseek = seq_lseek,
5ea473a1 1267 .release = single_release,
43ae34cb
IM		 1268};
1269
1270#endif
1271
4614a696
JS		 1272static ssize_t comm_write(struct file *file, const char __user *buf,
1273 size_t count, loff_t *offset)
1274{
1275 struct inode *inode = file->f_path.dentry->d_inode;
1276 struct task_struct *p;
1277 char buffer[TASK_COMM_LEN];
1278
1279 memset(buffer, 0, sizeof(buffer));
1280 if (count > sizeof(buffer) - 1)
1281 count = sizeof(buffer) - 1;
1282 if (copy_from_user(buffer, buf, count))
1283 return -EFAULT;
1284
1285 p = get_proc_task(inode);
1286 if (!p)
1287 return -ESRCH;
1288
1289 if (same_thread_group(current, p))
1290 set_task_comm(p, buffer);
1291 else
1292 count = -EINVAL;
1293
1294 put_task_struct(p);
1295
1296 return count;
1297}
1298
1299static int comm_show(struct seq_file *m, void *v)
1300{
1301 struct inode *inode = m->private;
1302 struct task_struct *p;
1303
1304 p = get_proc_task(inode);
1305 if (!p)
1306 return -ESRCH;
1307
1308 task_lock(p);
1309 seq_printf(m, "%s\n", p->comm);
1310 task_unlock(p);
1311
1312 put_task_struct(p);
1313
1314 return 0;
1315}
1316
1317static int comm_open(struct inode *inode, struct file *filp)
1318{
1319 int ret;
1320
1321 ret = single_open(filp, comm_show, NULL);
1322 if (!ret) {
1323 struct seq_file *m = filp->private_data;
1324
1325 m->private = inode;
1326 }
1327 return ret;
1328}
1329
1330static const struct file_operations proc_pid_set_comm_operations = {
1331 .open = comm_open,
1332 .read = seq_read,
1333 .write = comm_write,
1334 .llseek = seq_lseek,
1335 .release = single_release,
1336};
1337
925d1c40
MH		 1338/*
1339 * We added or removed a vma mapping the executable. The vmas are only mapped
1340 * during exec and are not mapped with the mmap system call.
1341 * Callers must hold down_write() on the mm's mmap_sem for these
1342 */
1343void added_exe_file_vma(struct mm_struct *mm)
1344{
1345 mm->num_exe_file_vmas++;
1346}
1347
1348void removed_exe_file_vma(struct mm_struct *mm)
1349{
1350 mm->num_exe_file_vmas--;
1351 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1352 fput(mm->exe_file);
1353 mm->exe_file = NULL;
1354 }
1355
1356}
1357
1358void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1359{
1360 if (new_exe_file)
1361 get_file(new_exe_file);
1362 if (mm->exe_file)
1363 fput(mm->exe_file);
1364 mm->exe_file = new_exe_file;
1365 mm->num_exe_file_vmas = 0;
1366}
1367
1368struct file *get_mm_exe_file(struct mm_struct *mm)
1369{
1370 struct file *exe_file;
1371
1372 /* We need mmap_sem to protect against races with removal of
1373 * VM_EXECUTABLE vmas */
1374 down_read(&mm->mmap_sem);
1375 exe_file = mm->exe_file;
1376 if (exe_file)
1377 get_file(exe_file);
1378 up_read(&mm->mmap_sem);
1379 return exe_file;
1380}
1381
1382void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1383{
1384 /* It's safe to write the exe_file pointer without exe_file_lock because
1385 * this is called during fork when the task is not yet in /proc */
1386 newmm->exe_file = get_mm_exe_file(oldmm);
1387}
1388
1389static int proc_exe_link(struct inode *inode, struct path *exe_path)
1390{
1391 struct task_struct *task;
1392 struct mm_struct *mm;
1393 struct file *exe_file;
1394
1395 task = get_proc_task(inode);
1396 if (!task)
1397 return -ENOENT;
1398 mm = get_task_mm(task);
1399 put_task_struct(task);
1400 if (!mm)
1401 return -ENOENT;
1402 exe_file = get_mm_exe_file(mm);
1403 mmput(mm);
1404 if (exe_file) {
1405 *exe_path = exe_file->f_path;
1406 path_get(&exe_file->f_path);
1407 fput(exe_file);
1408 return 0;
1409 } else
1410 return -ENOENT;
1411}
1412
008b150a 1413static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1da177e4
LT		 1414{
1415 struct inode *inode = dentry->d_inode;
1416 int error = -EACCES;
1417
1418 /* We don't need a base pointer in the /proc filesystem */
1d957f9b 1419 path_put(&nd->path);
1da177e4 1420
778c1144
EB		 1421 /* Are we allowed to snoop on the tasks file descriptors? */
1422 if (!proc_fd_access_allowed(inode))
1da177e4 1423 goto out;
1da177e4 1424
3dcd25f3 1425 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1da177e4 1426out:
008b150a 1427 return ERR_PTR(error);
1da177e4
LT		 1428}
1429
3dcd25f3 1430static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1da177e4 1431{
e12ba74d 1432 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
3dcd25f3 1433 char *pathname;
1da177e4
LT		 1434 int len;
1435
1436 if (!tmp)
1437 return -ENOMEM;
0c28f287 1438
cf28b486 1439 pathname = d_path(path, tmp, PAGE_SIZE);
3dcd25f3
JB		 1440 len = PTR_ERR(pathname);
1441 if (IS_ERR(pathname))
1da177e4 1442 goto out;
3dcd25f3 1443 len = tmp + PAGE_SIZE - 1 - pathname;
1da177e4
LT		 1444
1445 if (len > buflen)
1446 len = buflen;
3dcd25f3 1447 if (copy_to_user(buffer, pathname, len))
1da177e4
LT		 1448 len = -EFAULT;
1449 out:
1450 free_page((unsigned long)tmp);
1451 return len;
1452}
1453
1454static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1455{
1456 int error = -EACCES;
1457 struct inode *inode = dentry->d_inode;
3dcd25f3 1458 struct path path;
1da177e4 1459
778c1144
EB		 1460 /* Are we allowed to snoop on the tasks file descriptors? */
1461 if (!proc_fd_access_allowed(inode))
1da177e4 1462 goto out;
1da177e4 1463
3dcd25f3 1464 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1da177e4
LT		 1465 if (error)
1466 goto out;
1467
3dcd25f3
JB		 1468 error = do_proc_readlink(&path, buffer, buflen);
1469 path_put(&path);
1da177e4 1470out:
1da177e4
LT		 1471 return error;
1472}
1473
c5ef1c42 1474static const struct inode_operations proc_pid_link_inode_operations = {
1da177e4 1475 .readlink = proc_pid_readlink,
6d76fa58
LT		 1476 .follow_link = proc_pid_follow_link,
1477 .setattr = proc_setattr,
1da177e4
LT		 1478};
1479
28a6d671
EB		 1480
1481/* building an inode */
1482
1483static int task_dumpable(struct task_struct *task)
1da177e4 1484{
28a6d671
EB		 1485 int dumpable = 0;
1486 struct mm_struct *mm;
1da177e4 1487
28a6d671
EB		 1488 task_lock(task);
1489 mm = task->mm;
1490 if (mm)
6c5d5238 1491 dumpable = get_dumpable(mm);
28a6d671
EB		 1492 task_unlock(task);
1493 if(dumpable == 1)
1494 return 1;
1495 return 0;
1496}
1da177e4 1497
1da177e4 1498
61a28784 1499static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
28a6d671
EB		 1500{
1501 struct inode * inode;
1502 struct proc_inode *ei;
c69e8d9c 1503 const struct cred *cred;
1da177e4 1504
28a6d671 1505 /* We need a new inode */
1da177e4 1506
28a6d671
EB		 1507 inode = new_inode(sb);
1508 if (!inode)
1509 goto out;
1510
1511 /* Common stuff */
1512 ei = PROC_I(inode);
1513 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
28a6d671
EB		 1514 inode->i_op = &proc_def_inode_operations;
1515
1516 /*
1517 * grab the reference to task.
1518 */
1a657f78 1519 ei->pid = get_task_pid(task, PIDTYPE_PID);
28a6d671
EB		 1520 if (!ei->pid)
1521 goto out_unlock;
1522
28a6d671 1523 if (task_dumpable(task)) {
c69e8d9c
DH		 1524 rcu_read_lock();
1525 cred = __task_cred(task);
1526 inode->i_uid = cred->euid;
1527 inode->i_gid = cred->egid;
1528 rcu_read_unlock();
1da177e4 1529 }
28a6d671
EB		 1530 security_task_to_inode(task, inode);
1531
1da177e4 1532out:
28a6d671
EB		 1533 return inode;
1534
1535out_unlock:
1536 iput(inode);
1537 return NULL;
1da177e4
LT		 1538}
1539
28a6d671 1540static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1da177e4 1541{
1da177e4 1542 struct inode *inode = dentry->d_inode;
28a6d671 1543 struct task_struct *task;
c69e8d9c
DH		 1544 const struct cred *cred;
1545
28a6d671 1546 generic_fillattr(inode, stat);
1da177e4 1547
28a6d671
EB		 1548 rcu_read_lock();
1549 stat->uid = 0;
1550 stat->gid = 0;
1551 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1552 if (task) {
1553 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1554 task_dumpable(task)) {
c69e8d9c
DH		 1555 cred = __task_cred(task);
1556 stat->uid = cred->euid;
1557 stat->gid = cred->egid;
1da177e4
LT		 1558 }
1559 }
28a6d671 1560 rcu_read_unlock();
d6e71144 1561 return 0;
1da177e4
LT		 1562}
1563
1da177e4
LT		 1564/* dentry stuff */
1565
1566/*
1567 * Exceptional case: normally we are not allowed to unhash a busy
1568 * directory. In this case, however, we can do it - no aliasing problems
1569 * due to the way we treat inodes.
1570 *
1571 * Rewrite the inode's ownerships here because the owning task may have
1572 * performed a setuid(), etc.
99f89551
EB		 1573 *
1574 * Before the /proc/pid/status file was created the only way to read
1575 * the effective uid of a /process was to stat /proc/pid. Reading
1576 * /proc/pid/status is slow enough that procps and other packages
1577 * kept stating /proc/pid. To keep the rules in /proc simple I have
1578 * made this apply to all per process world readable and executable
1579 * directories.
1da177e4
LT		 1580 */
1581static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1582{
1583 struct inode *inode = dentry->d_inode;
99f89551 1584 struct task_struct *task = get_proc_task(inode);
c69e8d9c
DH		 1585 const struct cred *cred;
1586
99f89551
EB		 1587 if (task) {
1588 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1589 task_dumpable(task)) {
c69e8d9c
DH		 1590 rcu_read_lock();
1591 cred = __task_cred(task);
1592 inode->i_uid = cred->euid;
1593 inode->i_gid = cred->egid;
1594 rcu_read_unlock();
1da177e4
LT		 1595 } else {
1596 inode->i_uid = 0;
1597 inode->i_gid = 0;
1598 }
9ee8ab9f 1599 inode->i_mode &= ~(S_ISUID | S_ISGID);
1da177e4 1600 security_task_to_inode(task, inode);
99f89551 1601 put_task_struct(task);
1da177e4
LT		 1602 return 1;
1603 }
1604 d_drop(dentry);
1605 return 0;
1606}
1607
28a6d671 1608static int pid_delete_dentry(struct dentry * dentry)
99f89551 1609{
28a6d671
EB		 1610 /* Is the task we represent dead?
1611 * If so, then don't put the dentry on the lru list,
1612 * kill it immediately.
1613 */
1614 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1615}
1616
d72f71eb 1617static const struct dentry_operations pid_dentry_operations =
28a6d671
EB		 1618{
1619 .d_revalidate = pid_revalidate,
1620 .d_delete = pid_delete_dentry,
1621};
1622
1623/* Lookups */
1624
c5141e6d
ED		 1625typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1626 struct task_struct *, const void *);
61a28784 1627
1c0d04c9
EB		 1628/*
1629 * Fill a directory entry.
1630 *
1631 * If possible create the dcache entry and derive our inode number and
1632 * file type from dcache entry.
1633 *
1634 * Since all of the proc inode numbers are dynamically generated, the inode
1635 * numbers do not exist until the inode is cache. This means creating the
1636 * the dcache entry in readdir is necessary to keep the inode numbers
1637 * reported by readdir in sync with the inode numbers reported
1638 * by stat.
1639 */
61a28784
EB		 1640static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1641 char *name, int len,
c5141e6d 1642 instantiate_t instantiate, struct task_struct *task, const void *ptr)
61a28784 1643{
2fddfeef 1644 struct dentry *child, *dir = filp->f_path.dentry;
61a28784
EB		 1645 struct inode *inode;
1646 struct qstr qname;
1647 ino_t ino = 0;
1648 unsigned type = DT_UNKNOWN;
1649
1650 qname.name = name;
1651 qname.len = len;
1652 qname.hash = full_name_hash(name, len);
1653
1654 child = d_lookup(dir, &qname);
1655 if (!child) {
1656 struct dentry *new;
1657 new = d_alloc(dir, &qname);
1658 if (new) {
1659 child = instantiate(dir->d_inode, new, task, ptr);
1660 if (child)
1661 dput(new);
1662 else
1663 child = new;
1664 }
1665 }
1666 if (!child || IS_ERR(child) || !child->d_inode)
1667 goto end_instantiate;
1668 inode = child->d_inode;
1669 if (inode) {
1670 ino = inode->i_ino;
1671 type = inode->i_mode >> 12;
1672 }
1673 dput(child);
1674end_instantiate:
1675 if (!ino)
1676 ino = find_inode_number(dir, &qname);
1677 if (!ino)
1678 ino = 1;
1679 return filldir(dirent, name, len, filp->f_pos, ino, type);
1680}
1681
28a6d671
EB		 1682static unsigned name_to_int(struct dentry *dentry)
1683{
1684 const char *name = dentry->d_name.name;
1685 int len = dentry->d_name.len;
1686 unsigned n = 0;
1687
1688 if (len > 1 && *name == '0')
1689 goto out;
1690 while (len-- > 0) {
1691 unsigned c = *name++ - '0';
1692 if (c > 9)
1693 goto out;
1694 if (n >= (~0U-9)/10)
1695 goto out;
1696 n *= 10;
1697 n += c;
1698 }
1699 return n;
1700out:
1701 return ~0U;
1702}
1703
27932742
MS		 1704#define PROC_FDINFO_MAX 64
1705
3dcd25f3 1706static int proc_fd_info(struct inode *inode, struct path *path, char *info)
28a6d671
EB		 1707{
1708 struct task_struct *task = get_proc_task(inode);
1709 struct files_struct *files = NULL;
1710 struct file *file;
1711 int fd = proc_fd(inode);
99f89551 1712
99f89551 1713 if (task) {
28a6d671
EB		 1714 files = get_files_struct(task);
1715 put_task_struct(task);
1716 }
1717 if (files) {
1718 /*
1719 * We are not taking a ref to the file structure, so we must
1720 * hold ->file_lock.
1721 */
1722 spin_lock(&files->file_lock);
1723 file = fcheck_files(files, fd);
1724 if (file) {
3dcd25f3
JB		 1725 if (path) {
1726 *path = file->f_path;
1727 path_get(&file->f_path);
1728 }
27932742
MS		 1729 if (info)
1730 snprintf(info, PROC_FDINFO_MAX,
1731 "pos:\t%lli\n"
1732 "flags:\t0%o\n",
1733 (long long) file->f_pos,
1734 file->f_flags);
28a6d671
EB		 1735 spin_unlock(&files->file_lock);
1736 put_files_struct(files);
1737 return 0;
99f89551 1738 }
28a6d671
EB		 1739 spin_unlock(&files->file_lock);
1740 put_files_struct(files);
99f89551 1741 }
28a6d671 1742 return -ENOENT;
99f89551
EB		 1743}
1744
3dcd25f3 1745static int proc_fd_link(struct inode *inode, struct path *path)
27932742 1746{
3dcd25f3 1747 return proc_fd_info(inode, path, NULL);
27932742
MS		 1748}
1749
1da177e4
LT		 1750static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1751{
1752 struct inode *inode = dentry->d_inode;
99f89551 1753 struct task_struct *task = get_proc_task(inode);
aed7a6c4 1754 int fd = proc_fd(inode);
1da177e4 1755 struct files_struct *files;
c69e8d9c 1756 const struct cred *cred;
1da177e4 1757
99f89551
EB		 1758 if (task) {
1759 files = get_files_struct(task);
1760 if (files) {
1761 rcu_read_lock();
1762 if (fcheck_files(files, fd)) {
1763 rcu_read_unlock();
1764 put_files_struct(files);
1765 if (task_dumpable(task)) {
c69e8d9c
DH		 1766 rcu_read_lock();
1767 cred = __task_cred(task);
1768 inode->i_uid = cred->euid;
1769 inode->i_gid = cred->egid;
1770 rcu_read_unlock();
99f89551
EB		 1771 } else {
1772 inode->i_uid = 0;
1773 inode->i_gid = 0;
1774 }
9ee8ab9f 1775 inode->i_mode &= ~(S_ISUID | S_ISGID);
99f89551
EB		 1776 security_task_to_inode(task, inode);
1777 put_task_struct(task);
1778 return 1;
1779 }
b835996f 1780 rcu_read_unlock();
1da177e4 1781 put_files_struct(files);
1da177e4 1782 }
99f89551 1783 put_task_struct(task);
1da177e4
LT		 1784 }
1785 d_drop(dentry);
1786 return 0;
1787}
1788
d72f71eb 1789static const struct dentry_operations tid_fd_dentry_operations =
1da177e4
LT		 1790{
1791 .d_revalidate = tid_fd_revalidate,
1792 .d_delete = pid_delete_dentry,
1793};
1794
444ceed8 1795static struct dentry *proc_fd_instantiate(struct inode *dir,
c5141e6d 1796 struct dentry *dentry, struct task_struct *task, const void *ptr)
1da177e4 1797{
c5141e6d 1798 unsigned fd = *(const unsigned *)ptr;
444ceed8
EB		 1799 struct file *file;
1800 struct files_struct *files;
1801 struct inode *inode;
1802 struct proc_inode *ei;
1803 struct dentry *error = ERR_PTR(-ENOENT);
1da177e4 1804
61a28784 1805 inode = proc_pid_make_inode(dir->i_sb, task);
1da177e4
LT		 1806 if (!inode)
1807 goto out;
1808 ei = PROC_I(inode);
aed7a6c4 1809 ei->fd = fd;
1da177e4
LT		 1810 files = get_files_struct(task);
1811 if (!files)
444ceed8 1812 goto out_iput;
1da177e4 1813 inode->i_mode = S_IFLNK;
ca99c1da
DS		 1814
1815 /*
1816 * We are not taking a ref to the file structure, so we must
1817 * hold ->file_lock.
1818 */
1819 spin_lock(&files->file_lock);
1da177e4
LT		 1820 file = fcheck_files(files, fd);
1821 if (!file)
444ceed8 1822 goto out_unlock;
aeb5d727 1823 if (file->f_mode & FMODE_READ)
1da177e4 1824 inode->i_mode |= S_IRUSR | S_IXUSR;
aeb5d727 1825 if (file->f_mode & FMODE_WRITE)
1da177e4 1826 inode->i_mode |= S_IWUSR | S_IXUSR;
ca99c1da 1827 spin_unlock(&files->file_lock);
1da177e4 1828 put_files_struct(files);
444ceed8 1829
1da177e4
LT		 1830 inode->i_op = &proc_pid_link_inode_operations;
1831 inode->i_size = 64;
1832 ei->op.proc_get_link = proc_fd_link;
1833 dentry->d_op = &tid_fd_dentry_operations;
1834 d_add(dentry, inode);
cd6a3ce9
EB		 1835 /* Close the race of the process dying before we return the dentry */
1836 if (tid_fd_revalidate(dentry, NULL))
444ceed8 1837 error = NULL;
1da177e4 1838
444ceed8
EB		 1839 out:
1840 return error;
1841out_unlock:
ca99c1da 1842 spin_unlock(&files->file_lock);
1da177e4 1843 put_files_struct(files);
444ceed8 1844out_iput:
1da177e4 1845 iput(inode);
cd6a3ce9 1846 goto out;
1da177e4
LT		 1847}
1848
27932742
MS		 1849static struct dentry *proc_lookupfd_common(struct inode *dir,
1850 struct dentry *dentry,
1851 instantiate_t instantiate)
444ceed8
EB		 1852{
1853 struct task_struct *task = get_proc_task(dir);
1854 unsigned fd = name_to_int(dentry);
1855 struct dentry *result = ERR_PTR(-ENOENT);
1856
1857 if (!task)
1858 goto out_no_task;
1859 if (fd == ~0U)
1860 goto out;
1861
27932742 1862 result = instantiate(dir, dentry, task, &fd);
444ceed8
EB		 1863out:
1864 put_task_struct(task);
1865out_no_task:
1866 return result;
1867}
1868
27932742
MS		 1869static int proc_readfd_common(struct file * filp, void * dirent,
1870 filldir_t filldir, instantiate_t instantiate)
28a6d671 1871{
2fddfeef 1872 struct dentry *dentry = filp->f_path.dentry;
28a6d671
EB		 1873 struct inode *inode = dentry->d_inode;
1874 struct task_struct *p = get_proc_task(inode);
457c2510 1875 unsigned int fd, ino;
28a6d671 1876 int retval;
28a6d671 1877 struct files_struct * files;
1da177e4 1878
28a6d671
EB		 1879 retval = -ENOENT;
1880 if (!p)
1881 goto out_no_task;
1882 retval = 0;
28a6d671
EB		 1883
1884 fd = filp->f_pos;
1885 switch (fd) {
1886 case 0:
1887 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1888 goto out;
1889 filp->f_pos++;
1890 case 1:
1891 ino = parent_ino(dentry);
1892 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1893 goto out;
1894 filp->f_pos++;
1895 default:
1896 files = get_files_struct(p);
1897 if (!files)
1898 goto out;
1899 rcu_read_lock();
28a6d671 1900 for (fd = filp->f_pos-2;
9b4f526c 1901 fd < files_fdtable(files)->max_fds;
28a6d671 1902 fd++, filp->f_pos++) {
27932742
MS		 1903 char name[PROC_NUMBUF];
1904 int len;
28a6d671
EB		 1905
1906 if (!fcheck_files(files, fd))
1907 continue;
1908 rcu_read_unlock();
1909
27932742
MS		 1910 len = snprintf(name, sizeof(name), "%d", fd);
1911 if (proc_fill_cache(filp, dirent, filldir,
1912 name, len, instantiate,
1913 p, &fd) < 0) {
28a6d671
EB		 1914 rcu_read_lock();
1915 break;
1916 }
1917 rcu_read_lock();
1918 }
1919 rcu_read_unlock();
1920 put_files_struct(files);
1921 }
1922out:
1923 put_task_struct(p);
1924out_no_task:
1925 return retval;
1926}
1927
27932742
MS		 1928static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1929 struct nameidata *nd)
1930{
1931 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1932}
1933
1934static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1935{
1936 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1937}
1938
1939static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1940 size_t len, loff_t *ppos)
1941{
1942 char tmp[PROC_FDINFO_MAX];
3dcd25f3 1943 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
27932742
MS		 1944 if (!err)
1945 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1946 return err;
1947}
1948
1949static const struct file_operations proc_fdinfo_file_operations = {
87df8424 1950 .open = nonseekable_open,
27932742
MS		 1951 .read = proc_fdinfo_read,
1952};
1953
00977a59 1954static const struct file_operations proc_fd_operations = {
28a6d671
EB		 1955 .read = generic_read_dir,
1956 .readdir = proc_readfd,
1da177e4
LT		 1957};
1958
8948e11f
AD		 1959/*
1960 * /proc/pid/fd needs a special permission handler so that a process can still
1961 * access /proc/self/fd after it has executed a setuid().
1962 */
e6305c43 1963static int proc_fd_permission(struct inode *inode, int mask)
8948e11f
AD		 1964{
1965 int rv;
1966
1967 rv = generic_permission(inode, mask, NULL);
1968 if (rv == 0)
1969 return 0;
1970 if (task_pid(current) == proc_pid(inode))
1971 rv = 0;
1972 return rv;
1973}
1974
1da177e4
LT		 1975/*
1976 * proc directories can do almost nothing..
1977 */
c5ef1c42 1978static const struct inode_operations proc_fd_inode_operations = {
1da177e4 1979 .lookup = proc_lookupfd,
8948e11f 1980 .permission = proc_fd_permission,
6d76fa58 1981 .setattr = proc_setattr,
1da177e4
LT		 1982};
1983
27932742
MS		 1984static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1985 struct dentry *dentry, struct task_struct *task, const void *ptr)
1986{
1987 unsigned fd = *(unsigned *)ptr;
1988 struct inode *inode;
1989 struct proc_inode *ei;
1990 struct dentry *error = ERR_PTR(-ENOENT);
1991
1992 inode = proc_pid_make_inode(dir->i_sb, task);
1993 if (!inode)
1994 goto out;
1995 ei = PROC_I(inode);
1996 ei->fd = fd;
1997 inode->i_mode = S_IFREG | S_IRUSR;
1998 inode->i_fop = &proc_fdinfo_file_operations;
1999 dentry->d_op = &tid_fd_dentry_operations;
2000 d_add(dentry, inode);
2001 /* Close the race of the process dying before we return the dentry */
2002 if (tid_fd_revalidate(dentry, NULL))
2003 error = NULL;
2004
2005 out:
2006 return error;
2007}
2008
2009static struct dentry *proc_lookupfdinfo(struct inode *dir,
2010 struct dentry *dentry,
2011 struct nameidata *nd)
2012{
2013 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2014}
2015
2016static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2017{
2018 return proc_readfd_common(filp, dirent, filldir,
2019 proc_fdinfo_instantiate);
2020}
2021
2022static const struct file_operations proc_fdinfo_operations = {
2023 .read = generic_read_dir,
2024 .readdir = proc_readfdinfo,
2025};
2026
2027/*
2028 * proc directories can do almost nothing..
2029 */
2030static const struct inode_operations proc_fdinfo_inode_operations = {
2031 .lookup = proc_lookupfdinfo,
2032 .setattr = proc_setattr,
2033};
2034
2035
444ceed8 2036static struct dentry *proc_pident_instantiate(struct inode *dir,
c5141e6d 2037 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8 2038{
c5141e6d 2039 const struct pid_entry *p = ptr;
444ceed8
EB		 2040 struct inode *inode;
2041 struct proc_inode *ei;
bd6daba9 2042 struct dentry *error = ERR_PTR(-ENOENT);
444ceed8 2043
61a28784 2044 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 2045 if (!inode)
2046 goto out;
2047
2048 ei = PROC_I(inode);
2049 inode->i_mode = p->mode;
2050 if (S_ISDIR(inode->i_mode))
2051 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2052 if (p->iop)
2053 inode->i_op = p->iop;
2054 if (p->fop)
2055 inode->i_fop = p->fop;
2056 ei->op = p->op;
2057 dentry->d_op = &pid_dentry_operations;
2058 d_add(dentry, inode);
2059 /* Close the race of the process dying before we return the dentry */
2060 if (pid_revalidate(dentry, NULL))
2061 error = NULL;
2062out:
2063 return error;
2064}
2065
1da177e4
LT		 2066static struct dentry *proc_pident_lookup(struct inode *dir,
2067 struct dentry *dentry,
c5141e6d 2068 const struct pid_entry *ents,
7bcd6b0e 2069 unsigned int nents)
1da177e4 2070{
cd6a3ce9 2071 struct dentry *error;
99f89551 2072 struct task_struct *task = get_proc_task(dir);
c5141e6d 2073 const struct pid_entry *p, *last;
1da177e4 2074
cd6a3ce9 2075 error = ERR_PTR(-ENOENT);
1da177e4 2076
99f89551
EB		 2077 if (!task)
2078 goto out_no_task;
1da177e4 2079
20cdc894
EB		 2080 /*
2081 * Yes, it does not scale. And it should not. Don't add
2082 * new entries into /proc/<tgid>/ without very good reasons.
2083 */
7bcd6b0e
EB		 2084 last = &ents[nents - 1];
2085 for (p = ents; p <= last; p++) {
1da177e4
LT		 2086 if (p->len != dentry->d_name.len)
2087 continue;
2088 if (!memcmp(dentry->d_name.name, p->name, p->len))
2089 break;
2090 }
7bcd6b0e 2091 if (p > last)
1da177e4
LT		 2092 goto out;
2093
444ceed8 2094 error = proc_pident_instantiate(dir, dentry, task, p);
1da177e4 2095out:
99f89551
EB		 2096 put_task_struct(task);
2097out_no_task:
cd6a3ce9 2098 return error;
1da177e4
LT		 2099}
2100
c5141e6d
ED		 2101static int proc_pident_fill_cache(struct file *filp, void *dirent,
2102 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
61a28784
EB		 2103{
2104 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2105 proc_pident_instantiate, task, p);
2106}
2107
28a6d671
EB		 2108static int proc_pident_readdir(struct file *filp,
2109 void *dirent, filldir_t filldir,
c5141e6d 2110 const struct pid_entry *ents, unsigned int nents)
28a6d671
EB		 2111{
2112 int i;
2fddfeef 2113 struct dentry *dentry = filp->f_path.dentry;
28a6d671
EB		 2114 struct inode *inode = dentry->d_inode;
2115 struct task_struct *task = get_proc_task(inode);
c5141e6d 2116 const struct pid_entry *p, *last;
28a6d671
EB		 2117 ino_t ino;
2118 int ret;
2119
2120 ret = -ENOENT;
2121 if (!task)
61a28784 2122 goto out_no_task;
28a6d671
EB		 2123
2124 ret = 0;
28a6d671
EB		 2125 i = filp->f_pos;
2126 switch (i) {
2127 case 0:
2128 ino = inode->i_ino;
2129 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2130 goto out;
2131 i++;
2132 filp->f_pos++;
2133 /* fall through */
2134 case 1:
2135 ino = parent_ino(dentry);
2136 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2137 goto out;
2138 i++;
2139 filp->f_pos++;
2140 /* fall through */
2141 default:
2142 i -= 2;
2143 if (i >= nents) {
2144 ret = 1;
2145 goto out;
2146 }
2147 p = ents + i;
7bcd6b0e
EB		 2148 last = &ents[nents - 1];
2149 while (p <= last) {
61a28784 2150 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
28a6d671
EB		 2151 goto out;
2152 filp->f_pos++;
2153 p++;
2154 }
2155 }
2156
2157 ret = 1;
2158out:
61a28784
EB		 2159 put_task_struct(task);
2160out_no_task:
28a6d671 2161 return ret;
1da177e4
LT		 2162}
2163
28a6d671
EB		 2164#ifdef CONFIG_SECURITY
2165static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2166 size_t count, loff_t *ppos)
2167{
2fddfeef 2168 struct inode * inode = file->f_path.dentry->d_inode;
04ff9708 2169 char *p = NULL;
28a6d671
EB		 2170 ssize_t length;
2171 struct task_struct *task = get_proc_task(inode);
2172
28a6d671 2173 if (!task)
04ff9708 2174 return -ESRCH;
28a6d671
EB		 2175
2176 length = security_getprocattr(task,
2fddfeef 2177 (char*)file->f_path.dentry->d_name.name,
04ff9708 2178 &p);
28a6d671 2179 put_task_struct(task);
04ff9708
AV		 2180 if (length > 0)
2181 length = simple_read_from_buffer(buf, count, ppos, p, length);
2182 kfree(p);
28a6d671 2183 return length;
1da177e4
LT		 2184}
2185
28a6d671
EB		 2186static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2187 size_t count, loff_t *ppos)
2188{
2fddfeef 2189 struct inode * inode = file->f_path.dentry->d_inode;
28a6d671
EB		 2190 char *page;
2191 ssize_t length;
2192 struct task_struct *task = get_proc_task(inode);
2193
2194 length = -ESRCH;
2195 if (!task)
2196 goto out_no_task;
2197 if (count > PAGE_SIZE)
2198 count = PAGE_SIZE;
2199
2200 /* No partial writes. */
2201 length = -EINVAL;
2202 if (*ppos != 0)
2203 goto out;
2204
2205 length = -ENOMEM;
e12ba74d 2206 page = (char*)__get_free_page(GFP_TEMPORARY);
28a6d671
EB		 2207 if (!page)
2208 goto out;
2209
2210 length = -EFAULT;
2211 if (copy_from_user(page, buf, count))
2212 goto out_free;
2213
107db7c7
DH		 2214 /* Guard against adverse ptrace interaction */
2215 length = mutex_lock_interruptible(&task->cred_guard_mutex);
2216 if (length < 0)
2217 goto out_free;
2218
28a6d671 2219 length = security_setprocattr(task,
2fddfeef 2220 (char*)file->f_path.dentry->d_name.name,
28a6d671 2221 (void*)page, count);
107db7c7 2222 mutex_unlock(&task->cred_guard_mutex);
28a6d671
EB		 2223out_free:
2224 free_page((unsigned long) page);
2225out:
2226 put_task_struct(task);
2227out_no_task:
2228 return length;
2229}
2230
00977a59 2231static const struct file_operations proc_pid_attr_operations = {
28a6d671
EB		 2232 .read = proc_pid_attr_read,
2233 .write = proc_pid_attr_write,
87df8424 2234 .llseek = generic_file_llseek,
28a6d671
EB		 2235};
2236
c5141e6d 2237static const struct pid_entry attr_dir_stuff[] = {
631f9c18
AD		 2238 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2239 REG("prev", S_IRUGO, proc_pid_attr_operations),
2240 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2241 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2242 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2243 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
28a6d671
EB		 2244};
2245
72d9dcfc 2246static int proc_attr_dir_readdir(struct file * filp,
28a6d671
EB		 2247 void * dirent, filldir_t filldir)
2248{
2249 return proc_pident_readdir(filp,dirent,filldir,
72d9dcfc 2250 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2251}
2252
00977a59 2253static const struct file_operations proc_attr_dir_operations = {
1da177e4 2254 .read = generic_read_dir,
72d9dcfc 2255 .readdir = proc_attr_dir_readdir,
1da177e4
LT		 2256};
2257
72d9dcfc 2258static struct dentry *proc_attr_dir_lookup(struct inode *dir,
28a6d671
EB		 2259 struct dentry *dentry, struct nameidata *nd)
2260{
7bcd6b0e
EB		 2261 return proc_pident_lookup(dir, dentry,
2262 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
28a6d671
EB		 2263}
2264
c5ef1c42 2265static const struct inode_operations proc_attr_dir_inode_operations = {
72d9dcfc 2266 .lookup = proc_attr_dir_lookup,
99f89551 2267 .getattr = pid_getattr,
6d76fa58 2268 .setattr = proc_setattr,
1da177e4
LT		 2269};
2270
28a6d671
EB		 2271#endif
2272
698ba7b5 2273#ifdef CONFIG_ELF_CORE
3cb4a0bb
KH		 2274static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2275 size_t count, loff_t *ppos)
2276{
2277 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2278 struct mm_struct *mm;
2279 char buffer[PROC_NUMBUF];
2280 size_t len;
2281 int ret;
2282
2283 if (!task)
2284 return -ESRCH;
2285
2286 ret = 0;
2287 mm = get_task_mm(task);
2288 if (mm) {
2289 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2290 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2291 MMF_DUMP_FILTER_SHIFT));
2292 mmput(mm);
2293 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2294 }
2295
2296 put_task_struct(task);
2297
2298 return ret;
2299}
2300
2301static ssize_t proc_coredump_filter_write(struct file *file,
2302 const char __user *buf,
2303 size_t count,
2304 loff_t *ppos)
2305{
2306 struct task_struct *task;
2307 struct mm_struct *mm;
2308 char buffer[PROC_NUMBUF], *end;
2309 unsigned int val;
2310 int ret;
2311 int i;
2312 unsigned long mask;
2313
2314 ret = -EFAULT;
2315 memset(buffer, 0, sizeof(buffer));
2316 if (count > sizeof(buffer) - 1)
2317 count = sizeof(buffer) - 1;
2318 if (copy_from_user(buffer, buf, count))
2319 goto out_no_task;
2320
2321 ret = -EINVAL;
2322 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2323 if (*end == '\n')
2324 end++;
2325 if (end - buffer == 0)
2326 goto out_no_task;
2327
2328 ret = -ESRCH;
2329 task = get_proc_task(file->f_dentry->d_inode);
2330 if (!task)
2331 goto out_no_task;
2332
2333 ret = end - buffer;
2334 mm = get_task_mm(task);
2335 if (!mm)
2336 goto out_no_mm;
2337
2338 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2339 if (val & mask)
2340 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2341 else
2342 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2343 }
2344
2345 mmput(mm);
2346 out_no_mm:
2347 put_task_struct(task);
2348 out_no_task:
2349 return ret;
2350}
2351
2352static const struct file_operations proc_coredump_filter_operations = {
2353 .read = proc_coredump_filter_read,
2354 .write = proc_coredump_filter_write,
87df8424 2355 .llseek = generic_file_llseek,
3cb4a0bb
KH		 2356};
2357#endif
2358
28a6d671
EB		 2359/*
2360 * /proc/self:
2361 */
2362static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2363 int buflen)
2364{
488e5bc4 2365 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
b55fcb22 2366 pid_t tgid = task_tgid_nr_ns(current, ns);
28a6d671 2367 char tmp[PROC_NUMBUF];
b55fcb22 2368 if (!tgid)
488e5bc4 2369 return -ENOENT;
b55fcb22 2370 sprintf(tmp, "%d", tgid);
28a6d671
EB		 2371 return vfs_readlink(dentry,buffer,buflen,tmp);
2372}
2373
2374static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2375{
488e5bc4 2376 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
b55fcb22 2377 pid_t tgid = task_tgid_nr_ns(current, ns);
7fee4868
AV		 2378 char *name = ERR_PTR(-ENOENT);
2379 if (tgid) {
2380 name = __getname();
2381 if (!name)
2382 name = ERR_PTR(-ENOMEM);
2383 else
2384 sprintf(name, "%d", tgid);
2385 }
2386 nd_set_link(nd, name);
2387 return NULL;
2388}
2389
2390static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2391 void *cookie)
2392{
2393 char *s = nd_get_link(nd);
2394 if (!IS_ERR(s))
2395 __putname(s);
28a6d671
EB		 2396}
2397
c5ef1c42 2398static const struct inode_operations proc_self_inode_operations = {
28a6d671
EB		 2399 .readlink = proc_self_readlink,
2400 .follow_link = proc_self_follow_link,
7fee4868 2401 .put_link = proc_self_put_link,
28a6d671
EB		 2402};
2403
801199ce
EB		 2404/*
2405 * proc base
2406 *
2407 * These are the directory entries in the root directory of /proc
2408 * that properly belong to the /proc filesystem, as they describe
2409 * describe something that is process related.
2410 */
c5141e6d 2411static const struct pid_entry proc_base_stuff[] = {
61a28784 2412 NOD("self", S_IFLNK|S_IRWXUGO,
801199ce 2413 &proc_self_inode_operations, NULL, {}),
801199ce
EB		 2414};
2415
2416/*
2417 * Exceptional case: normally we are not allowed to unhash a busy
2418 * directory. In this case, however, we can do it - no aliasing problems
2419 * due to the way we treat inodes.
2420 */
2421static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2422{
2423 struct inode *inode = dentry->d_inode;
2424 struct task_struct *task = get_proc_task(inode);
2425 if (task) {
2426 put_task_struct(task);
2427 return 1;
2428 }
2429 d_drop(dentry);
2430 return 0;
2431}
2432
d72f71eb 2433static const struct dentry_operations proc_base_dentry_operations =
801199ce
EB		 2434{
2435 .d_revalidate = proc_base_revalidate,
2436 .d_delete = pid_delete_dentry,
2437};
2438
444ceed8 2439static struct dentry *proc_base_instantiate(struct inode *dir,
c5141e6d 2440 struct dentry *dentry, struct task_struct *task, const void *ptr)
801199ce 2441{
c5141e6d 2442 const struct pid_entry *p = ptr;
801199ce 2443 struct inode *inode;
801199ce 2444 struct proc_inode *ei;
73d36460 2445 struct dentry *error;
801199ce
EB		 2446
2447 /* Allocate the inode */
2448 error = ERR_PTR(-ENOMEM);
2449 inode = new_inode(dir->i_sb);
2450 if (!inode)
2451 goto out;
2452
2453 /* Initialize the inode */
2454 ei = PROC_I(inode);
2455 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
801199ce
EB		 2456
2457 /*
2458 * grab the reference to the task.
2459 */
1a657f78 2460 ei->pid = get_task_pid(task, PIDTYPE_PID);
801199ce
EB		 2461 if (!ei->pid)
2462 goto out_iput;
2463
801199ce
EB		 2464 inode->i_mode = p->mode;
2465 if (S_ISDIR(inode->i_mode))
2466 inode->i_nlink = 2;
2467 if (S_ISLNK(inode->i_mode))
2468 inode->i_size = 64;
2469 if (p->iop)
2470 inode->i_op = p->iop;
2471 if (p->fop)
2472 inode->i_fop = p->fop;
2473 ei->op = p->op;
2474 dentry->d_op = &proc_base_dentry_operations;
2475 d_add(dentry, inode);
2476 error = NULL;
2477out:
801199ce
EB		 2478 return error;
2479out_iput:
2480 iput(inode);
2481 goto out;
2482}
2483
444ceed8
EB		 2484static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2485{
2486 struct dentry *error;
2487 struct task_struct *task = get_proc_task(dir);
c5141e6d 2488 const struct pid_entry *p, *last;
444ceed8
EB		 2489
2490 error = ERR_PTR(-ENOENT);
2491
2492 if (!task)
2493 goto out_no_task;
2494
2495 /* Lookup the directory entry */
7bcd6b0e
EB		 2496 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2497 for (p = proc_base_stuff; p <= last; p++) {
444ceed8
EB		 2498 if (p->len != dentry->d_name.len)
2499 continue;
2500 if (!memcmp(dentry->d_name.name, p->name, p->len))
2501 break;
2502 }
7bcd6b0e 2503 if (p > last)
444ceed8
EB		 2504 goto out;
2505
2506 error = proc_base_instantiate(dir, dentry, task, p);
2507
2508out:
2509 put_task_struct(task);
2510out_no_task:
2511 return error;
2512}
2513
c5141e6d
ED		 2514static int proc_base_fill_cache(struct file *filp, void *dirent,
2515 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
61a28784
EB		 2516{
2517 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2518 proc_base_instantiate, task, p);
2519}
2520
aba76fdb 2521#ifdef CONFIG_TASK_IO_ACCOUNTING
297c5d92
AR		 2522static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2523{
940389b8 2524 struct task_io_accounting acct = task->ioac;
5995477a
AR		 2525 unsigned long flags;
2526
2527 if (whole && lock_task_sighand(task, &flags)) {
2528 struct task_struct *t = task;
2529
2530 task_io_accounting_add(&acct, &task->signal->ioac);
2531 while_each_thread(task, t)
2532 task_io_accounting_add(&acct, &t->ioac);
2533
2534 unlock_task_sighand(task, &flags);
297c5d92 2535 }
aba76fdb
AM		 2536 return sprintf(buffer,
2537 "rchar: %llu\n"
2538 "wchar: %llu\n"
2539 "syscr: %llu\n"
2540 "syscw: %llu\n"
2541 "read_bytes: %llu\n"
2542 "write_bytes: %llu\n"
2543 "cancelled_write_bytes: %llu\n",
7c44319d
AB		 2544 (unsigned long long)acct.rchar,
2545 (unsigned long long)acct.wchar,
2546 (unsigned long long)acct.syscr,
2547 (unsigned long long)acct.syscw,
2548 (unsigned long long)acct.read_bytes,
2549 (unsigned long long)acct.write_bytes,
2550 (unsigned long long)acct.cancelled_write_bytes);
297c5d92
AR		 2551}
2552
2553static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2554{
2555 return do_io_accounting(task, buffer, 0);
aba76fdb 2556}
297c5d92
AR		 2557
2558static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2559{
2560 return do_io_accounting(task, buffer, 1);
2561}
2562#endif /* CONFIG_TASK_IO_ACCOUNTING */
aba76fdb 2563
47830723
KC		 2564static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2565 struct pid *pid, struct task_struct *task)
2566{
2567 seq_printf(m, "%08x\n", task->personality);
2568 return 0;
2569}
2570
28a6d671
EB		 2571/*
2572 * Thread groups
2573 */
00977a59 2574static const struct file_operations proc_task_operations;
c5ef1c42 2575static const struct inode_operations proc_task_inode_operations;
20cdc894 2576
c5141e6d 2577static const struct pid_entry tgid_base_stuff[] = {
631f9c18
AD		 2578 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2579 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2580 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
b2211a36 2581#ifdef CONFIG_NET
631f9c18 2582 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
b2211a36 2583#endif
631f9c18
AD		 2584 REG("environ", S_IRUSR, proc_environ_operations),
2585 INF("auxv", S_IRUSR, proc_pid_auxv),
2586 ONE("status", S_IRUGO, proc_pid_status),
2587 ONE("personality", S_IRUSR, proc_pid_personality),
2588 INF("limits", S_IRUSR, proc_pid_limits),
43ae34cb 2589#ifdef CONFIG_SCHED_DEBUG
631f9c18 2590 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
ebcb6734 2591#endif
4614a696 2592 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 2593#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
631f9c18 2594 INF("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 2595#endif
631f9c18
AD		 2596 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2597 ONE("stat", S_IRUGO, proc_tgid_stat),
2598 ONE("statm", S_IRUGO, proc_pid_statm),
2599 REG("maps", S_IRUGO, proc_maps_operations),
28a6d671 2600#ifdef CONFIG_NUMA
631f9c18 2601 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
28a6d671 2602#endif
631f9c18
AD		 2603 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2604 LNK("cwd", proc_cwd_link),
2605 LNK("root", proc_root_link),
2606 LNK("exe", proc_exe_link),
2607 REG("mounts", S_IRUGO, proc_mounts_operations),
2608 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2609 REG("mountstats", S_IRUSR, proc_mountstats_operations),
1e883281 2610#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18
AD		 2611 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2612 REG("smaps", S_IRUGO, proc_smaps_operations),
2613 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 2614#endif
2615#ifdef CONFIG_SECURITY
631f9c18 2616 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 2617#endif
2618#ifdef CONFIG_KALLSYMS
631f9c18 2619 INF("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 2620#endif
2ec220e2
KC		 2621#ifdef CONFIG_STACKTRACE
2622 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671
EB		 2623#endif
2624#ifdef CONFIG_SCHEDSTATS
631f9c18 2625 INF("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 2626#endif
9745512c 2627#ifdef CONFIG_LATENCYTOP
631f9c18 2628 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 2629#endif
8793d854 2630#ifdef CONFIG_PROC_PID_CPUSET
631f9c18 2631 REG("cpuset", S_IRUGO, proc_cpuset_operations),
a424316c
PM		 2632#endif
2633#ifdef CONFIG_CGROUPS
631f9c18 2634 REG("cgroup", S_IRUGO, proc_cgroup_operations),
28a6d671 2635#endif
631f9c18
AD		 2636 INF("oom_score", S_IRUGO, proc_oom_score),
2637 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
28a6d671 2638#ifdef CONFIG_AUDITSYSCALL
631f9c18
AD		 2639 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2640 REG("sessionid", S_IRUGO, proc_sessionid_operations),
28a6d671 2641#endif
f4f154fd 2642#ifdef CONFIG_FAULT_INJECTION
631f9c18 2643 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 2644#endif
698ba7b5 2645#ifdef CONFIG_ELF_CORE
631f9c18 2646 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3cb4a0bb 2647#endif
aba76fdb 2648#ifdef CONFIG_TASK_IO_ACCOUNTING
631f9c18 2649 INF("io", S_IRUGO, proc_tgid_io_accounting),
aba76fdb 2650#endif
28a6d671 2651};
1da177e4 2652
28a6d671 2653static int proc_tgid_base_readdir(struct file * filp,
1da177e4
LT		 2654 void * dirent, filldir_t filldir)
2655{
2656 return proc_pident_readdir(filp,dirent,filldir,
28a6d671 2657 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 2658}
2659
00977a59 2660static const struct file_operations proc_tgid_base_operations = {
1da177e4 2661 .read = generic_read_dir,
28a6d671 2662 .readdir = proc_tgid_base_readdir,
1da177e4
LT		 2663};
2664
28a6d671 2665static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
7bcd6b0e
EB		 2666 return proc_pident_lookup(dir, dentry,
2667 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
1da177e4
LT		 2668}
2669
c5ef1c42 2670static const struct inode_operations proc_tgid_base_inode_operations = {
28a6d671 2671 .lookup = proc_tgid_base_lookup,
99f89551 2672 .getattr = pid_getattr,
6d76fa58 2673 .setattr = proc_setattr,
1da177e4 2674};
1da177e4 2675
60347f67 2676static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
1da177e4 2677{
48e6484d 2678 struct dentry *dentry, *leader, *dir;
8578cea7 2679 char buf[PROC_NUMBUF];
48e6484d
EB		 2680 struct qstr name;
2681
2682 name.name = buf;
60347f67
PE		 2683 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2684 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d 2685 if (dentry) {
29f12ca3 2686 shrink_dcache_parent(dentry);
48e6484d
EB		 2687 d_drop(dentry);
2688 dput(dentry);
2689 }
1da177e4 2690
48e6484d 2691 name.name = buf;
60347f67
PE		 2692 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2693 leader = d_hash_and_lookup(mnt->mnt_root, &name);
48e6484d
EB		 2694 if (!leader)
2695 goto out;
1da177e4 2696
48e6484d
EB		 2697 name.name = "task";
2698 name.len = strlen(name.name);
2699 dir = d_hash_and_lookup(leader, &name);
2700 if (!dir)
2701 goto out_put_leader;
2702
2703 name.name = buf;
60347f67 2704 name.len = snprintf(buf, sizeof(buf), "%d", pid);
48e6484d
EB		 2705 dentry = d_hash_and_lookup(dir, &name);
2706 if (dentry) {
2707 shrink_dcache_parent(dentry);
2708 d_drop(dentry);
2709 dput(dentry);
1da177e4 2710 }
48e6484d
EB		 2711
2712 dput(dir);
2713out_put_leader:
2714 dput(leader);
2715out:
2716 return;
1da177e4
LT		 2717}
2718
0895e91d
RD		 2719/**
2720 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2721 * @task: task that should be flushed.
2722 *
2723 * When flushing dentries from proc, one needs to flush them from global
60347f67 2724 * proc (proc_mnt) and from all the namespaces' procs this task was seen
0895e91d
RD		 2725 * in. This call is supposed to do all of this job.
2726 *
2727 * Looks in the dcache for
2728 * /proc/@pid
2729 * /proc/@tgid/task/@pid
2730 * if either directory is present flushes it and all of it'ts children
2731 * from the dcache.
2732 *
2733 * It is safe and reasonable to cache /proc entries for a task until
2734 * that task exits. After that they just clog up the dcache with
2735 * useless entries, possibly causing useful dcache entries to be
2736 * flushed instead. This routine is proved to flush those useless
2737 * dcache entries at process exit time.
2738 *
2739 * NOTE: This routine is just an optimization so it does not guarantee
2740 * that no dcache entries will exist at process exit time it
2741 * just makes it very unlikely that any will persist.
60347f67
PE		 2742 */
2743
2744void proc_flush_task(struct task_struct *task)
2745{
9fcc2d15 2746 int i;
9b4d1cbe 2747 struct pid *pid, *tgid;
130f77ec
PE		 2748 struct upid *upid;
2749
130f77ec 2750 pid = task_pid(task);
9b4d1cbe 2751 tgid = task_tgid(task);
130f77ec 2752
9fcc2d15 2753 for (i = 0; i <= pid->level; i++) {
130f77ec
PE		 2754 upid = &pid->numbers[i];
2755 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
9b4d1cbe 2756 tgid->numbers[i].nr);
130f77ec 2757 }
6f4e6433
PE		 2758
2759 upid = &pid->numbers[pid->level];
2760 if (upid->nr == 1)
2761 pid_ns_release_proc(upid->ns);
60347f67
PE		 2762}
2763
9711ef99
AB		 2764static struct dentry *proc_pid_instantiate(struct inode *dir,
2765 struct dentry * dentry,
c5141e6d 2766 struct task_struct *task, const void *ptr)
444ceed8
EB		 2767{
2768 struct dentry *error = ERR_PTR(-ENOENT);
2769 struct inode *inode;
2770
61a28784 2771 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 2772 if (!inode)
2773 goto out;
2774
2775 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2776 inode->i_op = &proc_tgid_base_inode_operations;
2777 inode->i_fop = &proc_tgid_base_operations;
2778 inode->i_flags|=S_IMMUTABLE;
aed54175
VN		 2779
2780 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2781 ARRAY_SIZE(tgid_base_stuff));
444ceed8
EB		 2782
2783 dentry->d_op = &pid_dentry_operations;
2784
2785 d_add(dentry, inode);
2786 /* Close the race of the process dying before we return the dentry */
2787 if (pid_revalidate(dentry, NULL))
2788 error = NULL;
2789out:
2790 return error;
2791}
2792
1da177e4
LT		 2793struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2794{
73d36460 2795 struct dentry *result;
1da177e4 2796 struct task_struct *task;
1da177e4 2797 unsigned tgid;
b488893a 2798 struct pid_namespace *ns;
1da177e4 2799
801199ce
EB		 2800 result = proc_base_lookup(dir, dentry);
2801 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2802 goto out;
2803
1da177e4
LT		 2804 tgid = name_to_int(dentry);
2805 if (tgid == ~0U)
2806 goto out;
2807
b488893a 2808 ns = dentry->d_sb->s_fs_info;
de758734 2809 rcu_read_lock();
b488893a 2810 task = find_task_by_pid_ns(tgid, ns);
1da177e4
LT		 2811 if (task)
2812 get_task_struct(task);
de758734 2813 rcu_read_unlock();
1da177e4
LT		 2814 if (!task)
2815 goto out;
2816
444ceed8 2817 result = proc_pid_instantiate(dir, dentry, task, NULL);
1da177e4 2818 put_task_struct(task);
1da177e4 2819out:
cd6a3ce9 2820 return result;
1da177e4
LT		 2821}
2822
1da177e4 2823/*
0804ef4b 2824 * Find the first task with tgid >= tgid
0bc58a91 2825 *
1da177e4 2826 */
19fd4bb2
EB		 2827struct tgid_iter {
2828 unsigned int tgid;
0804ef4b 2829 struct task_struct *task;
19fd4bb2
EB		 2830};
2831static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2832{
0804ef4b 2833 struct pid *pid;
1da177e4 2834
19fd4bb2
EB		 2835 if (iter.task)
2836 put_task_struct(iter.task);
454cc105 2837 rcu_read_lock();
0804ef4b 2838retry:
19fd4bb2
EB		 2839 iter.task = NULL;
2840 pid = find_ge_pid(iter.tgid, ns);
0804ef4b 2841 if (pid) {
19fd4bb2
EB		 2842 iter.tgid = pid_nr_ns(pid, ns);
2843 iter.task = pid_task(pid, PIDTYPE_PID);
0804ef4b
EB		 2844 /* What we to know is if the pid we have find is the
2845 * pid of a thread_group_leader. Testing for task
2846 * being a thread_group_leader is the obvious thing
2847 * todo but there is a window when it fails, due to
2848 * the pid transfer logic in de_thread.
2849 *
2850 * So we perform the straight forward test of seeing
2851 * if the pid we have found is the pid of a thread
2852 * group leader, and don't worry if the task we have
2853 * found doesn't happen to be a thread group leader.
2854 * As we don't care in the case of readdir.
2855 */
19fd4bb2
EB		 2856 if (!iter.task || !has_group_leader_pid(iter.task)) {
2857 iter.tgid += 1;
0804ef4b 2858 goto retry;
19fd4bb2
EB		 2859 }
2860 get_task_struct(iter.task);
0bc58a91 2861 }
454cc105 2862 rcu_read_unlock();
19fd4bb2 2863 return iter;
1da177e4
LT		 2864}
2865
7bcd6b0e 2866#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
0804ef4b 2867
61a28784 2868static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
19fd4bb2 2869 struct tgid_iter iter)
61a28784
EB		 2870{
2871 char name[PROC_NUMBUF];
19fd4bb2 2872 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
61a28784 2873 return proc_fill_cache(filp, dirent, filldir, name, len,
19fd4bb2 2874 proc_pid_instantiate, iter.task, NULL);
61a28784
EB		 2875}
2876
1da177e4
LT		 2877/* for the /proc/ directory itself, after non-process stuff has been done */
2878int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2879{
1da177e4 2880 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2fddfeef 2881 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
19fd4bb2 2882 struct tgid_iter iter;
b488893a 2883 struct pid_namespace *ns;
1da177e4 2884
61a28784
EB		 2885 if (!reaper)
2886 goto out_no_task;
2887
7bcd6b0e 2888 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
c5141e6d 2889 const struct pid_entry *p = &proc_base_stuff[nr];
61a28784 2890 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
801199ce 2891 goto out;
1da177e4
LT		 2892 }
2893
b488893a 2894 ns = filp->f_dentry->d_sb->s_fs_info;
19fd4bb2
EB		 2895 iter.task = NULL;
2896 iter.tgid = filp->f_pos - TGID_OFFSET;
2897 for (iter = next_tgid(ns, iter);
2898 iter.task;
2899 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2900 filp->f_pos = iter.tgid + TGID_OFFSET;
2901 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2902 put_task_struct(iter.task);
0804ef4b 2903 goto out;
1da177e4 2904 }
0bc58a91 2905 }
0804ef4b
EB		 2906 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2907out:
61a28784
EB		 2908 put_task_struct(reaper);
2909out_no_task:
0bc58a91
EB		 2910 return 0;
2911}
1da177e4 2912
28a6d671
EB		 2913/*
2914 * Tasks
2915 */
c5141e6d 2916static const struct pid_entry tid_base_stuff[] = {
631f9c18 2917 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3835541d 2918 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
631f9c18
AD		 2919 REG("environ", S_IRUSR, proc_environ_operations),
2920 INF("auxv", S_IRUSR, proc_pid_auxv),
2921 ONE("status", S_IRUGO, proc_pid_status),
2922 ONE("personality", S_IRUSR, proc_pid_personality),
2923 INF("limits", S_IRUSR, proc_pid_limits),
43ae34cb 2924#ifdef CONFIG_SCHED_DEBUG
631f9c18 2925 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
ebcb6734 2926#endif
4614a696 2927 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
ebcb6734 2928#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
631f9c18 2929 INF("syscall", S_IRUSR, proc_pid_syscall),
43ae34cb 2930#endif
631f9c18
AD		 2931 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2932 ONE("stat", S_IRUGO, proc_tid_stat),
2933 ONE("statm", S_IRUGO, proc_pid_statm),
2934 REG("maps", S_IRUGO, proc_maps_operations),
28a6d671 2935#ifdef CONFIG_NUMA
631f9c18 2936 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
28a6d671 2937#endif
631f9c18
AD		 2938 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2939 LNK("cwd", proc_cwd_link),
2940 LNK("root", proc_root_link),
2941 LNK("exe", proc_exe_link),
2942 REG("mounts", S_IRUGO, proc_mounts_operations),
2943 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
1e883281 2944#ifdef CONFIG_PROC_PAGE_MONITOR
631f9c18
AD		 2945 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2946 REG("smaps", S_IRUGO, proc_smaps_operations),
2947 REG("pagemap", S_IRUSR, proc_pagemap_operations),
28a6d671
EB		 2948#endif
2949#ifdef CONFIG_SECURITY
631f9c18 2950 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
28a6d671
EB		 2951#endif
2952#ifdef CONFIG_KALLSYMS
631f9c18 2953 INF("wchan", S_IRUGO, proc_pid_wchan),
28a6d671 2954#endif
2ec220e2
KC		 2955#ifdef CONFIG_STACKTRACE
2956 ONE("stack", S_IRUSR, proc_pid_stack),
28a6d671
EB		 2957#endif
2958#ifdef CONFIG_SCHEDSTATS
631f9c18 2959 INF("schedstat", S_IRUGO, proc_pid_schedstat),
28a6d671 2960#endif
9745512c 2961#ifdef CONFIG_LATENCYTOP
631f9c18 2962 REG("latency", S_IRUGO, proc_lstats_operations),
9745512c 2963#endif
8793d854 2964#ifdef CONFIG_PROC_PID_CPUSET
631f9c18 2965 REG("cpuset", S_IRUGO, proc_cpuset_operations),
a424316c
PM		 2966#endif
2967#ifdef CONFIG_CGROUPS
631f9c18 2968 REG("cgroup", S_IRUGO, proc_cgroup_operations),
28a6d671 2969#endif
631f9c18
AD		 2970 INF("oom_score", S_IRUGO, proc_oom_score),
2971 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
28a6d671 2972#ifdef CONFIG_AUDITSYSCALL
631f9c18
AD		 2973 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2974 REG("sessionid", S_IRUSR, proc_sessionid_operations),
28a6d671 2975#endif
f4f154fd 2976#ifdef CONFIG_FAULT_INJECTION
631f9c18 2977 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
f4f154fd 2978#endif
297c5d92 2979#ifdef CONFIG_TASK_IO_ACCOUNTING
631f9c18 2980 INF("io", S_IRUGO, proc_tid_io_accounting),
297c5d92 2981#endif
28a6d671
EB		 2982};
2983
2984static int proc_tid_base_readdir(struct file * filp,
2985 void * dirent, filldir_t filldir)
2986{
2987 return proc_pident_readdir(filp,dirent,filldir,
2988 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2989}
2990
2991static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
7bcd6b0e
EB		 2992 return proc_pident_lookup(dir, dentry,
2993 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
28a6d671
EB		 2994}
2995
00977a59 2996static const struct file_operations proc_tid_base_operations = {
28a6d671
EB		 2997 .read = generic_read_dir,
2998 .readdir = proc_tid_base_readdir,
2999};
3000
c5ef1c42 3001static const struct inode_operations proc_tid_base_inode_operations = {
28a6d671
EB		 3002 .lookup = proc_tid_base_lookup,
3003 .getattr = pid_getattr,
3004 .setattr = proc_setattr,
3005};
3006
444ceed8 3007static struct dentry *proc_task_instantiate(struct inode *dir,
c5141e6d 3008 struct dentry *dentry, struct task_struct *task, const void *ptr)
444ceed8
EB		 3009{
3010 struct dentry *error = ERR_PTR(-ENOENT);
3011 struct inode *inode;
61a28784 3012 inode = proc_pid_make_inode(dir->i_sb, task);
444ceed8
EB		 3013
3014 if (!inode)
3015 goto out;
3016 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3017 inode->i_op = &proc_tid_base_inode_operations;
3018 inode->i_fop = &proc_tid_base_operations;
3019 inode->i_flags|=S_IMMUTABLE;
aed54175
VN		 3020
3021 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3022 ARRAY_SIZE(tid_base_stuff));
444ceed8
EB		 3023
3024 dentry->d_op = &pid_dentry_operations;
3025
3026 d_add(dentry, inode);
3027 /* Close the race of the process dying before we return the dentry */
3028 if (pid_revalidate(dentry, NULL))
3029 error = NULL;
3030out:
3031 return error;
3032}
3033
28a6d671
EB		 3034static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3035{
3036 struct dentry *result = ERR_PTR(-ENOENT);
3037 struct task_struct *task;
3038 struct task_struct *leader = get_proc_task(dir);
28a6d671 3039 unsigned tid;
b488893a 3040 struct pid_namespace *ns;
28a6d671
EB		 3041
3042 if (!leader)
3043 goto out_no_task;
3044
3045 tid = name_to_int(dentry);
3046 if (tid == ~0U)
3047 goto out;
3048
b488893a 3049 ns = dentry->d_sb->s_fs_info;
28a6d671 3050 rcu_read_lock();
b488893a 3051 task = find_task_by_pid_ns(tid, ns);
28a6d671
EB		 3052 if (task)
3053 get_task_struct(task);
3054 rcu_read_unlock();
3055 if (!task)
3056 goto out;
bac0abd6 3057 if (!same_thread_group(leader, task))
28a6d671
EB		 3058 goto out_drop_task;
3059
444ceed8 3060 result = proc_task_instantiate(dir, dentry, task, NULL);
28a6d671
EB		 3061out_drop_task:
3062 put_task_struct(task);
3063out:
3064 put_task_struct(leader);
3065out_no_task:
3066 return result;
3067}
3068
0bc58a91
EB		 3069/*
3070 * Find the first tid of a thread group to return to user space.
3071 *
3072 * Usually this is just the thread group leader, but if the users
3073 * buffer was too small or there was a seek into the middle of the
3074 * directory we have more work todo.
3075 *
3076 * In the case of a short read we start with find_task_by_pid.
3077 *
3078 * In the case of a seek we start with the leader and walk nr
3079 * threads past it.
3080 */
cc288738 3081static struct task_struct *first_tid(struct task_struct *leader,
b488893a 3082 int tid, int nr, struct pid_namespace *ns)
0bc58a91 3083{
a872ff0c 3084 struct task_struct *pos;
1da177e4 3085
cc288738 3086 rcu_read_lock();
0bc58a91
EB		 3087 /* Attempt to start with the pid of a thread */
3088 if (tid && (nr > 0)) {
b488893a 3089 pos = find_task_by_pid_ns(tid, ns);
a872ff0c
ON		 3090 if (pos && (pos->group_leader == leader))
3091 goto found;
0bc58a91 3092 }
1da177e4 3093
0bc58a91 3094 /* If nr exceeds the number of threads there is nothing todo */
a872ff0c
ON		 3095 pos = NULL;
3096 if (nr && nr >= get_nr_threads(leader))
3097 goto out;
1da177e4 3098
a872ff0c
ON		 3099 /* If we haven't found our starting place yet start
3100 * with the leader and walk nr threads forward.
0bc58a91 3101 */
a872ff0c
ON		 3102 for (pos = leader; nr > 0; --nr) {
3103 pos = next_thread(pos);
3104 if (pos == leader) {
3105 pos = NULL;
3106 goto out;
3107 }
1da177e4 3108 }
a872ff0c
ON		 3109found:
3110 get_task_struct(pos);
3111out:
cc288738 3112 rcu_read_unlock();
0bc58a91
EB		 3113 return pos;
3114}
3115
3116/*
3117 * Find the next thread in the thread list.
3118 * Return NULL if there is an error or no next thread.
3119 *
3120 * The reference to the input task_struct is released.
3121 */
3122static struct task_struct *next_tid(struct task_struct *start)
3123{
c1df7fb8 3124 struct task_struct *pos = NULL;
cc288738 3125 rcu_read_lock();
c1df7fb8 3126 if (pid_alive(start)) {
0bc58a91 3127 pos = next_thread(start);
c1df7fb8
ON		 3128 if (thread_group_leader(pos))
3129 pos = NULL;
3130 else
3131 get_task_struct(pos);
3132 }
cc288738 3133 rcu_read_unlock();
0bc58a91
EB		 3134 put_task_struct(start);
3135 return pos;
1da177e4
LT		 3136}
3137
61a28784
EB		 3138static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3139 struct task_struct *task, int tid)
3140{
3141 char name[PROC_NUMBUF];
3142 int len = snprintf(name, sizeof(name), "%d", tid);
3143 return proc_fill_cache(filp, dirent, filldir, name, len,
3144 proc_task_instantiate, task, NULL);
3145}
3146
1da177e4
LT		 3147/* for the /proc/TGID/task/ directories */
3148static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3149{
2fddfeef 3150 struct dentry *dentry = filp->f_path.dentry;
1da177e4 3151 struct inode *inode = dentry->d_inode;
7d895244 3152 struct task_struct *leader = NULL;
0bc58a91 3153 struct task_struct *task;
1da177e4
LT		 3154 int retval = -ENOENT;
3155 ino_t ino;
0bc58a91 3156 int tid;
b488893a 3157 struct pid_namespace *ns;
1da177e4 3158
7d895244
GC		 3159 task = get_proc_task(inode);
3160 if (!task)
3161 goto out_no_task;
3162 rcu_read_lock();
3163 if (pid_alive(task)) {
3164 leader = task->group_leader;
3165 get_task_struct(leader);
3166 }
3167 rcu_read_unlock();
3168 put_task_struct(task);
99f89551
EB		 3169 if (!leader)
3170 goto out_no_task;
1da177e4
LT		 3171 retval = 0;
3172
ee568b25 3173 switch ((unsigned long)filp->f_pos) {
1da177e4
LT		 3174 case 0:
3175 ino = inode->i_ino;
ee6f779b 3176 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
1da177e4 3177 goto out;
ee6f779b 3178 filp->f_pos++;
1da177e4
LT		 3179 /* fall through */
3180 case 1:
3181 ino = parent_ino(dentry);
ee6f779b 3182 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
1da177e4 3183 goto out;
ee6f779b 3184 filp->f_pos++;
1da177e4
LT		 3185 /* fall through */
3186 }
3187
0bc58a91
EB		 3188 /* f_version caches the tgid value that the last readdir call couldn't
3189 * return. lseek aka telldir automagically resets f_version to 0.
3190 */
b488893a 3191 ns = filp->f_dentry->d_sb->s_fs_info;
2b47c361 3192 tid = (int)filp->f_version;
0bc58a91 3193 filp->f_version = 0;
ee6f779b 3194 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
0bc58a91 3195 task;
ee6f779b 3196 task = next_tid(task), filp->f_pos++) {
b488893a 3197 tid = task_pid_nr_ns(task, ns);
61a28784 3198 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
0bc58a91
EB		 3199 /* returning this tgid failed, save it as the first
3200 * pid for the next readir call */
2b47c361 3201 filp->f_version = (u64)tid;
0bc58a91 3202 put_task_struct(task);
1da177e4 3203 break;
0bc58a91 3204 }
1da177e4
LT		 3205 }
3206out:
99f89551
EB		 3207 put_task_struct(leader);
3208out_no_task:
1da177e4
LT		 3209 return retval;
3210}
6e66b52b
EB		 3211
3212static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3213{
3214 struct inode *inode = dentry->d_inode;
99f89551 3215 struct task_struct *p = get_proc_task(inode);
6e66b52b
EB		 3216 generic_fillattr(inode, stat);
3217
99f89551 3218 if (p) {
99f89551 3219 stat->nlink += get_nr_threads(p);
99f89551 3220 put_task_struct(p);
6e66b52b
EB		 3221 }
3222
3223 return 0;
3224}
28a6d671 3225
c5ef1c42 3226static const struct inode_operations proc_task_inode_operations = {
28a6d671
EB		 3227 .lookup = proc_task_lookup,
3228 .getattr = proc_task_getattr,
3229 .setattr = proc_setattr,
3230};
3231
00977a59 3232static const struct file_operations proc_task_operations = {
28a6d671
EB		 3233 .read = generic_read_dir,
3234 .readdir = proc_task_readdir,
3235};
kernel source for telekom puls (alcatel/mediatek)