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