1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51 #include <linux/uaccess.h>
52
53 #include <linux/errno.h>
54 #include <linux/time.h>
55 #include <linux/proc_fs.h>
56 #include <linux/stat.h>
57 #include <linux/task_io_accounting_ops.h>
58 #include <linux/init.h>
59 #include <linux/capability.h>
60 #include <linux/file.h>
61 #include <linux/fdtable.h>
62 #include <linux/string.h>
63 #include <linux/seq_file.h>
64 #include <linux/namei.h>
65 #include <linux/mnt_namespace.h>
66 #include <linux/mm.h>
67 #include <linux/swap.h>
68 #include <linux/rcupdate.h>
69 #include <linux/kallsyms.h>
70 #include <linux/stacktrace.h>
71 #include <linux/resource.h>
72 #include <linux/module.h>
73 #include <linux/mount.h>
74 #include <linux/security.h>
75 #include <linux/ptrace.h>
76 #include <linux/tracehook.h>
77 #include <linux/printk.h>
78 #include <linux/cache.h>
79 #include <linux/cgroup.h>
80 #include <linux/cpuset.h>
81 #include <linux/audit.h>
82 #include <linux/poll.h>
83 #include <linux/nsproxy.h>
84 #include <linux/oom.h>
85 #include <linux/elf.h>
86 #include <linux/pid_namespace.h>
87 #include <linux/user_namespace.h>
88 #include <linux/fs_struct.h>
89 #include <linux/slab.h>
90 #include <linux/sched/autogroup.h>
91 #include <linux/sched/mm.h>
92 #include <linux/sched/coredump.h>
93 #include <linux/sched/debug.h>
94 #include <linux/sched/stat.h>
95 #include <linux/flex_array.h>
96 #include <linux/posix-timers.h>
97 #ifdef CONFIG_HARDWALL
98 #include <asm/hardwall.h>
99 #endif
100 #include <trace/events/oom.h>
101 #include "internal.h"
102 #include "fd.h"
103
104 #include "../../lib/kstrtox.h"
105
106 /* NOTE:
107 * Implementing inode permission operations in /proc is almost
108 * certainly an error. Permission checks need to happen during
109 * each system call not at open time. The reason is that most of
110 * what we wish to check for permissions in /proc varies at runtime.
111 *
112 * The classic example of a problem is opening file descriptors
113 * in /proc for a task before it execs a suid executable.
114 */
115
116 static u8 nlink_tid __ro_after_init;
117 static u8 nlink_tgid __ro_after_init;
118
119 struct pid_entry {
120 const char *name;
121 unsigned int len;
122 umode_t mode;
123 const struct inode_operations *iop;
124 const struct file_operations *fop;
125 union proc_op op;
126 };
127
128 #define NOD(NAME, MODE, IOP, FOP, OP) { \
129 .name = (NAME), \
130 .len = sizeof(NAME) - 1, \
131 .mode = MODE, \
132 .iop = IOP, \
133 .fop = FOP, \
134 .op = OP, \
135 }
136
137 #define DIR(NAME, MODE, iops, fops) \
138 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
139 #define LNK(NAME, get_link) \
140 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
141 &proc_pid_link_inode_operations, NULL, \
142 { .proc_get_link = get_link } )
143 #define REG(NAME, MODE, fops) \
144 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
145 #define ONE(NAME, MODE, show) \
146 NOD(NAME, (S_IFREG|(MODE)), \
147 NULL, &proc_single_file_operations, \
148 { .proc_show = show } )
149
150 /*
151 * Count the number of hardlinks for the pid_entry table, excluding the .
152 * and .. links.
153 */
154 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
155 unsigned int n)
156 {
157 unsigned int i;
158 unsigned int count;
159
160 count = 2;
161 for (i = 0; i < n; ++i) {
162 if (S_ISDIR(entries[i].mode))
163 ++count;
164 }
165
166 return count;
167 }
168
169 static int get_task_root(struct task_struct *task, struct path *root)
170 {
171 int result = -ENOENT;
172
173 task_lock(task);
174 if (task->fs) {
175 get_fs_root(task->fs, root);
176 result = 0;
177 }
178 task_unlock(task);
179 return result;
180 }
181
182 static int proc_cwd_link(struct dentry *dentry, struct path *path)
183 {
184 struct task_struct *task = get_proc_task(d_inode(dentry));
185 int result = -ENOENT;
186
187 if (task) {
188 task_lock(task);
189 if (task->fs) {
190 get_fs_pwd(task->fs, path);
191 result = 0;
192 }
193 task_unlock(task);
194 put_task_struct(task);
195 }
196 return result;
197 }
198
199 static int proc_root_link(struct dentry *dentry, struct path *path)
200 {
201 struct task_struct *task = get_proc_task(d_inode(dentry));
202 int result = -ENOENT;
203
204 if (task) {
205 result = get_task_root(task, path);
206 put_task_struct(task);
207 }
208 return result;
209 }
210
211 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
212 size_t _count, loff_t *pos)
213 {
214 struct task_struct *tsk;
215 struct mm_struct *mm;
216 char *page;
217 unsigned long count = _count;
218 unsigned long arg_start, arg_end, env_start, env_end;
219 unsigned long len1, len2, len;
220 unsigned long p;
221 char c;
222 ssize_t rv;
223
224 BUG_ON(*pos < 0);
225
226 tsk = get_proc_task(file_inode(file));
227 if (!tsk)
228 return -ESRCH;
229 mm = get_task_mm(tsk);
230 put_task_struct(tsk);
231 if (!mm)
232 return 0;
233 /* Check if process spawned far enough to have cmdline. */
234 if (!mm->env_end) {
235 rv = 0;
236 goto out_mmput;
237 }
238
239 page = (char *)__get_free_page(GFP_KERNEL);
240 if (!page) {
241 rv = -ENOMEM;
242 goto out_mmput;
243 }
244
245 down_read(&mm->mmap_sem);
246 arg_start = mm->arg_start;
247 arg_end = mm->arg_end;
248 env_start = mm->env_start;
249 env_end = mm->env_end;
250 up_read(&mm->mmap_sem);
251
252 BUG_ON(arg_start > arg_end);
253 BUG_ON(env_start > env_end);
254
255 len1 = arg_end - arg_start;
256 len2 = env_end - env_start;
257
258 /* Empty ARGV. */
259 if (len1 == 0) {
260 rv = 0;
261 goto out_free_page;
262 }
263 /*
264 * Inherently racy -- command line shares address space
265 * with code and data.
266 */
267 rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON);
268 if (rv <= 0)
269 goto out_free_page;
270
271 rv = 0;
272
273 if (c == '\0') {
274 /* Command line (set of strings) occupies whole ARGV. */
275 if (len1 <= *pos)
276 goto out_free_page;
277
278 p = arg_start + *pos;
279 len = len1 - *pos;
280 while (count > 0 && len > 0) {
281 unsigned int _count;
282 int nr_read;
283
284 _count = min3(count, len, PAGE_SIZE);
285 nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
286 if (nr_read < 0)
287 rv = nr_read;
288 if (nr_read <= 0)
289 goto out_free_page;
290
291 if (copy_to_user(buf, page, nr_read)) {
292 rv = -EFAULT;
293 goto out_free_page;
294 }
295
296 p += nr_read;
297 len -= nr_read;
298 buf += nr_read;
299 count -= nr_read;
300 rv += nr_read;
301 }
302 } else {
303 /*
304 * Command line (1 string) occupies ARGV and
305 * extends into ENVP.
306 */
307 struct {
308 unsigned long p;
309 unsigned long len;
310 } cmdline[2] = {
311 { .p = arg_start, .len = len1 },
312 { .p = env_start, .len = len2 },
313 };
314 loff_t pos1 = *pos;
315 unsigned int i;
316
317 i = 0;
318 while (i < 2 && pos1 >= cmdline[i].len) {
319 pos1 -= cmdline[i].len;
320 i++;
321 }
322 while (i < 2) {
323 p = cmdline[i].p + pos1;
324 len = cmdline[i].len - pos1;
325 while (count > 0 && len > 0) {
326 unsigned int _count, l;
327 int nr_read;
328 bool final;
329
330 _count = min3(count, len, PAGE_SIZE);
331 nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
332 if (nr_read < 0)
333 rv = nr_read;
334 if (nr_read <= 0)
335 goto out_free_page;
336
337 /*
338 * Command line can be shorter than whole ARGV
339 * even if last "marker" byte says it is not.
340 */
341 final = false;
342 l = strnlen(page, nr_read);
343 if (l < nr_read) {
344 nr_read = l;
345 final = true;
346 }
347
348 if (copy_to_user(buf, page, nr_read)) {
349 rv = -EFAULT;
350 goto out_free_page;
351 }
352
353 p += nr_read;
354 len -= nr_read;
355 buf += nr_read;
356 count -= nr_read;
357 rv += nr_read;
358
359 if (final)
360 goto out_free_page;
361 }
362
363 /* Only first chunk can be read partially. */
364 pos1 = 0;
365 i++;
366 }
367 }
368
369 out_free_page:
370 free_page((unsigned long)page);
371 out_mmput:
372 mmput(mm);
373 if (rv > 0)
374 *pos += rv;
375 return rv;
376 }
377
378 static const struct file_operations proc_pid_cmdline_ops = {
379 .read = proc_pid_cmdline_read,
380 .llseek = generic_file_llseek,
381 };
382
383 #ifdef CONFIG_KALLSYMS
384 /*
385 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
386 * Returns the resolved symbol. If that fails, simply return the address.
387 */
388 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
389 struct pid *pid, struct task_struct *task)
390 {
391 unsigned long wchan;
392 char symname[KSYM_NAME_LEN];
393
394 wchan = get_wchan(task);
395
396 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
397 && !lookup_symbol_name(wchan, symname))
398 seq_printf(m, "%s", symname);
399 else
400 seq_putc(m, '');
401
402 return 0;
403 }
404 #endif /* CONFIG_KALLSYMS */
405
406 static int lock_trace(struct task_struct *task)
407 {
408 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
409 if (err)
410 return err;
411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 mutex_unlock(&task->signal->cred_guard_mutex);
413 return -EPERM;
414 }
415 return 0;
416 }
417
418 static void unlock_trace(struct task_struct *task)
419 {
420 mutex_unlock(&task->signal->cred_guard_mutex);
421 }
422
423 #ifdef CONFIG_STACKTRACE
424
425 #define MAX_STACK_TRACE_DEPTH 64
426
427 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
428 struct pid *pid, struct task_struct *task)
429 {
430 struct stack_trace trace;
431 unsigned long *entries;
432 int err;
433 int i;
434
435 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
436 if (!entries)
437 return -ENOMEM;
438
439 trace.nr_entries = 0;
440 trace.max_entries = MAX_STACK_TRACE_DEPTH;
441 trace.entries = entries;
442 trace.skip = 0;
443
444 err = lock_trace(task);
445 if (!err) {
446 save_stack_trace_tsk(task, &trace);
447
448 for (i = 0; i < trace.nr_entries; i++) {
449 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
450 }
451 unlock_trace(task);
452 }
453 kfree(entries);
454
455 return err;
456 }
457 #endif
458
459 #ifdef CONFIG_SCHED_INFO
460 /*
461 * Provides /proc/PID/schedstat
462 */
463 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
464 struct pid *pid, struct task_struct *task)
465 {
466 if (unlikely(!sched_info_on()))
467 seq_printf(m, "0 0 0\n");
468 else
469 seq_printf(m, "%llu %llu %lu\n",
470 (unsigned long long)task->se.sum_exec_runtime,
471 (unsigned long long)task->sched_info.run_delay,
472 task->sched_info.pcount);
473
474 return 0;
475 }
476 #endif
477
478 #ifdef CONFIG_LATENCYTOP
479 static int lstats_show_proc(struct seq_file *m, void *v)
480 {
481 int i;
482 struct inode *inode = m->private;
483 struct task_struct *task = get_proc_task(inode);
484
485 if (!task)
486 return -ESRCH;
487 seq_puts(m, "Latency Top version : v0.1\n");
488 for (i = 0; i < 32; i++) {
489 struct latency_record *lr = &task->latency_record[i];
490 if (lr->backtrace[0]) {
491 int q;
492 seq_printf(m, "%i %li %li",
493 lr->count, lr->time, lr->max);
494 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
495 unsigned long bt = lr->backtrace[q];
496 if (!bt)
497 break;
498 if (bt == ULONG_MAX)
499 break;
500 seq_printf(m, " %ps", (void *)bt);
501 }
502 seq_putc(m, '\n');
503 }
504
505 }
506 put_task_struct(task);
507 return 0;
508 }
509
510 static int lstats_open(struct inode *inode, struct file *file)
511 {
512 return single_open(file, lstats_show_proc, inode);
513 }
514
515 static ssize_t lstats_write(struct file *file, const char __user *buf,
516 size_t count, loff_t *offs)
517 {
518 struct task_struct *task = get_proc_task(file_inode(file));
519
520 if (!task)
521 return -ESRCH;
522 clear_all_latency_tracing(task);
523 put_task_struct(task);
524
525 return count;
526 }
527
528 static const struct file_operations proc_lstats_operations = {
529 .open = lstats_open,
530 .read = seq_read,
531 .write = lstats_write,
532 .llseek = seq_lseek,
533 .release = single_release,
534 };
535
536 #endif
537
538 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
539 struct pid *pid, struct task_struct *task)
540 {
541 unsigned long totalpages = totalram_pages + total_swap_pages;
542 unsigned long points = 0;
543
544 points = oom_badness(task, NULL, NULL, totalpages) *
545 1000 / totalpages;
546 seq_printf(m, "%lu\n", points);
547
548 return 0;
549 }
550
551 struct limit_names {
552 const char *name;
553 const char *unit;
554 };
555
556 static const struct limit_names lnames[RLIM_NLIMITS] = {
557 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
558 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
559 [RLIMIT_DATA] = {"Max data size", "bytes"},
560 [RLIMIT_STACK] = {"Max stack size", "bytes"},
561 [RLIMIT_CORE] = {"Max core file size", "bytes"},
562 [RLIMIT_RSS] = {"Max resident set", "bytes"},
563 [RLIMIT_NPROC] = {"Max processes", "processes"},
564 [RLIMIT_NOFILE] = {"Max open files", "files"},
565 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
566 [RLIMIT_AS] = {"Max address space", "bytes"},
567 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
568 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
569 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
570 [RLIMIT_NICE] = {"Max nice priority", NULL},
571 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
572 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
573 };
574
575 /* Display limits for a process */
576 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
577 struct pid *pid, struct task_struct *task)
578 {
579 unsigned int i;
580 unsigned long flags;
581
582 struct rlimit rlim[RLIM_NLIMITS];
583
584 if (!lock_task_sighand(task, &flags))
585 return 0;
586 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
587 unlock_task_sighand(task, &flags);
588
589 /*
590 * print the file header
591 */
592 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
593 "Limit", "Soft Limit", "Hard Limit", "Units");
594
595 for (i = 0; i < RLIM_NLIMITS; i++) {
596 if (rlim[i].rlim_cur == RLIM_INFINITY)
597 seq_printf(m, "%-25s %-20s ",
598 lnames[i].name, "unlimited");
599 else
600 seq_printf(m, "%-25s %-20lu ",
601 lnames[i].name, rlim[i].rlim_cur);
602
603 if (rlim[i].rlim_max == RLIM_INFINITY)
604 seq_printf(m, "%-20s ", "unlimited");
605 else
606 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
607
608 if (lnames[i].unit)
609 seq_printf(m, "%-10s\n", lnames[i].unit);
610 else
611 seq_putc(m, '\n');
612 }
613
614 return 0;
615 }
616
617 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
618 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
619 struct pid *pid, struct task_struct *task)
620 {
621 long nr;
622 unsigned long args[6], sp, pc;
623 int res;
624
625 res = lock_trace(task);
626 if (res)
627 return res;
628
629 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
630 seq_puts(m, "running\n");
631 else if (nr < 0)
632 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
633 else
634 seq_printf(m,
635 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
636 nr,
637 args[0], args[1], args[2], args[3], args[4], args[5],
638 sp, pc);
639 unlock_trace(task);
640
641 return 0;
642 }
643 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
644
645 /************************************************************************/
646 /* Here the fs part begins */
647 /************************************************************************/
648
649 /* permission checks */
650 static int proc_fd_access_allowed(struct inode *inode)
651 {
652 struct task_struct *task;
653 int allowed = 0;
654 /* Allow access to a task's file descriptors if it is us or we
655 * may use ptrace attach to the process and find out that
656 * information.
657 */
658 task = get_proc_task(inode);
659 if (task) {
660 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
661 put_task_struct(task);
662 }
663 return allowed;
664 }
665
666 int proc_setattr(struct dentry *dentry, struct iattr *attr)
667 {
668 int error;
669 struct inode *inode = d_inode(dentry);
670
671 if (attr->ia_valid & ATTR_MODE)
672 return -EPERM;
673
674 error = setattr_prepare(dentry, attr);
675 if (error)
676 return error;
677
678 setattr_copy(inode, attr);
679 mark_inode_dirty(inode);
680 return 0;
681 }
682
683 /*
684 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
685 * or euid/egid (for hide_pid_min=2)?
686 */
687 static bool has_pid_permissions(struct pid_namespace *pid,
688 struct task_struct *task,
689 int hide_pid_min)
690 {
691 if (pid->hide_pid < hide_pid_min)
692 return true;
693 if (in_group_p(pid->pid_gid))
694 return true;
695 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
696 }
697
698
699 static int proc_pid_permission(struct inode *inode, int mask)
700 {
701 struct pid_namespace *pid = inode->i_sb->s_fs_info;
702 struct task_struct *task;
703 bool has_perms;
704
705 task = get_proc_task(inode);
706 if (!task)
707 return -ESRCH;
708 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
709 put_task_struct(task);
710
711 if (!has_perms) {
712 if (pid->hide_pid == HIDEPID_INVISIBLE) {
713 /*
714 * Let's make getdents(), stat(), and open()
715 * consistent with each other. If a process
716 * may not stat() a file, it shouldn't be seen
717 * in procfs at all.
718 */
719 return -ENOENT;
720 }
721
722 return -EPERM;
723 }
724 return generic_permission(inode, mask);
725 }
726
727
728
729 static const struct inode_operations proc_def_inode_operations = {
730 .setattr = proc_setattr,
731 };
732
733 static int proc_single_show(struct seq_file *m, void *v)
734 {
735 struct inode *inode = m->private;
736 struct pid_namespace *ns;
737 struct pid *pid;
738 struct task_struct *task;
739 int ret;
740
741 ns = inode->i_sb->s_fs_info;
742 pid = proc_pid(inode);
743 task = get_pid_task(pid, PIDTYPE_PID);
744 if (!task)
745 return -ESRCH;
746
747 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
748
749 put_task_struct(task);
750 return ret;
751 }
752
753 static int proc_single_open(struct inode *inode, struct file *filp)
754 {
755 return single_open(filp, proc_single_show, inode);
756 }
757
758 static const struct file_operations proc_single_file_operations = {
759 .open = proc_single_open,
760 .read = seq_read,
761 .llseek = seq_lseek,
762 .release = single_release,
763 };
764
765
766 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
767 {
768 struct task_struct *task = get_proc_task(inode);
769 struct mm_struct *mm = ERR_PTR(-ESRCH);
770
771 if (task) {
772 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
773 put_task_struct(task);
774
775 if (!IS_ERR_OR_NULL(mm)) {
776 /* ensure this mm_struct can't be freed */
777 mmgrab(mm);
778 /* but do not pin its memory */
779 mmput(mm);
780 }
781 }
782
783 return mm;
784 }
785
786 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
787 {
788 struct mm_struct *mm = proc_mem_open(inode, mode);
789
790 if (IS_ERR(mm))
791 return PTR_ERR(mm);
792
793 file->private_data = mm;
794 return 0;
795 }
796
797 static int mem_open(struct inode *inode, struct file *file)
798 {
799 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
800
801 /* OK to pass negative loff_t, we can catch out-of-range */
802 file->f_mode |= FMODE_UNSIGNED_OFFSET;
803
804 return ret;
805 }
806
807 static ssize_t mem_rw(struct file *file, char __user *buf,
808 size_t count, loff_t *ppos, int write)
809 {
810 struct mm_struct *mm = file->private_data;
811 unsigned long addr = *ppos;
812 ssize_t copied;
813 char *page;
814 unsigned int flags;
815
816 if (!mm)
817 return 0;
818
819 page = (char *)__get_free_page(GFP_KERNEL);
820 if (!page)
821 return -ENOMEM;
822
823 copied = 0;
824 if (!mmget_not_zero(mm))
825 goto free;
826
827 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
828
829 while (count > 0) {
830 int this_len = min_t(int, count, PAGE_SIZE);
831
832 if (write && copy_from_user(page, buf, this_len)) {
833 copied = -EFAULT;
834 break;
835 }
836
837 this_len = access_remote_vm(mm, addr, page, this_len, flags);
838 if (!this_len) {
839 if (!copied)
840 copied = -EIO;
841 break;
842 }
843
844 if (!write && copy_to_user(buf, page, this_len)) {
845 copied = -EFAULT;
846 break;
847 }
848
849 buf += this_len;
850 addr += this_len;
851 copied += this_len;
852 count -= this_len;
853 }
854 *ppos = addr;
855
856 mmput(mm);
857 free:
858 free_page((unsigned long) page);
859 return copied;
860 }
861
862 static ssize_t mem_read(struct file *file, char __user *buf,
863 size_t count, loff_t *ppos)
864 {
865 return mem_rw(file, buf, count, ppos, 0);
866 }
867
868 static ssize_t mem_write(struct file *file, const char __user *buf,
869 size_t count, loff_t *ppos)
870 {
871 return mem_rw(file, (char __user*)buf, count, ppos, 1);
872 }
873
874 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
875 {
876 switch (orig) {
877 case 0:
878 file->f_pos = offset;
879 break;
880 case 1:
881 file->f_pos += offset;
882 break;
883 default:
884 return -EINVAL;
885 }
886 force_successful_syscall_return();
887 return file->f_pos;
888 }
889
890 static int mem_release(struct inode *inode, struct file *file)
891 {
892 struct mm_struct *mm = file->private_data;
893 if (mm)
894 mmdrop(mm);
895 return 0;
896 }
897
898 static const struct file_operations proc_mem_operations = {
899 .llseek = mem_lseek,
900 .read = mem_read,
901 .write = mem_write,
902 .open = mem_open,
903 .release = mem_release,
904 };
905
906 static int environ_open(struct inode *inode, struct file *file)
907 {
908 return __mem_open(inode, file, PTRACE_MODE_READ);
909 }
910
911 static ssize_t environ_read(struct file *file, char __user *buf,
912 size_t count, loff_t *ppos)
913 {
914 char *page;
915 unsigned long src = *ppos;
916 int ret = 0;
917 struct mm_struct *mm = file->private_data;
918 unsigned long env_start, env_end;
919
920 /* Ensure the process spawned far enough to have an environment. */
921 if (!mm || !mm->env_end)
922 return 0;
923
924 page = (char *)__get_free_page(GFP_KERNEL);
925 if (!page)
926 return -ENOMEM;
927
928 ret = 0;
929 if (!mmget_not_zero(mm))
930 goto free;
931
932 down_read(&mm->mmap_sem);
933 env_start = mm->env_start;
934 env_end = mm->env_end;
935 up_read(&mm->mmap_sem);
936
937 while (count > 0) {
938 size_t this_len, max_len;
939 int retval;
940
941 if (src >= (env_end - env_start))
942 break;
943
944 this_len = env_end - (env_start + src);
945
946 max_len = min_t(size_t, PAGE_SIZE, count);
947 this_len = min(max_len, this_len);
948
949 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
950
951 if (retval <= 0) {
952 ret = retval;
953 break;
954 }
955
956 if (copy_to_user(buf, page, retval)) {
957 ret = -EFAULT;
958 break;
959 }
960
961 ret += retval;
962 src += retval;
963 buf += retval;
964 count -= retval;
965 }
966 *ppos = src;
967 mmput(mm);
968
969 free:
970 free_page((unsigned long) page);
971 return ret;
972 }
973
974 static const struct file_operations proc_environ_operations = {
975 .open = environ_open,
976 .read = environ_read,
977 .llseek = generic_file_llseek,
978 .release = mem_release,
979 };
980
981 static int auxv_open(struct inode *inode, struct file *file)
982 {
983 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
984 }
985
986 static ssize_t auxv_read(struct file *file, char __user *buf,
987 size_t count, loff_t *ppos)
988 {
989 struct mm_struct *mm = file->private_data;
990 unsigned int nwords = 0;
991
992 if (!mm)
993 return 0;
994 do {
995 nwords += 2;
996 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
997 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
998 nwords * sizeof(mm->saved_auxv[0]));
999 }
1000
1001 static const struct file_operations proc_auxv_operations = {
1002 .open = auxv_open,
1003 .read = auxv_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006 };
1007
1008 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1009 loff_t *ppos)
1010 {
1011 struct task_struct *task = get_proc_task(file_inode(file));
1012 char buffer[PROC_NUMBUF];
1013 int oom_adj = OOM_ADJUST_MIN;
1014 size_t len;
1015
1016 if (!task)
1017 return -ESRCH;
1018 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1019 oom_adj = OOM_ADJUST_MAX;
1020 else
1021 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1022 OOM_SCORE_ADJ_MAX;
1023 put_task_struct(task);
1024 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1025 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1026 }
1027
1028 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1029 {
1030 static DEFINE_MUTEX(oom_adj_mutex);
1031 struct mm_struct *mm = NULL;
1032 struct task_struct *task;
1033 int err = 0;
1034
1035 task = get_proc_task(file_inode(file));
1036 if (!task)
1037 return -ESRCH;
1038
1039 mutex_lock(&oom_adj_mutex);
1040 if (legacy) {
1041 if (oom_adj < task->signal->oom_score_adj &&
1042 !capable(CAP_SYS_RESOURCE)) {
1043 err = -EACCES;
1044 goto err_unlock;
1045 }
1046 /*
1047 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1048 * /proc/pid/oom_score_adj instead.
1049 */
1050 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1051 current->comm, task_pid_nr(current), task_pid_nr(task),
1052 task_pid_nr(task));
1053 } else {
1054 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1055 !capable(CAP_SYS_RESOURCE)) {
1056 err = -EACCES;
1057 goto err_unlock;
1058 }
1059 }
1060
1061 /*
1062 * Make sure we will check other processes sharing the mm if this is
1063 * not vfrok which wants its own oom_score_adj.
1064 * pin the mm so it doesn't go away and get reused after task_unlock
1065 */
1066 if (!task->vfork_done) {
1067 struct task_struct *p = find_lock_task_mm(task);
1068
1069 if (p) {
1070 if (atomic_read(&p->mm->mm_users) > 1) {
1071 mm = p->mm;
1072 mmgrab(mm);
1073 }
1074 task_unlock(p);
1075 }
1076 }
1077
1078 task->signal->oom_score_adj = oom_adj;
1079 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1080 task->signal->oom_score_adj_min = (short)oom_adj;
1081 trace_oom_score_adj_update(task);
1082
1083 if (mm) {
1084 struct task_struct *p;
1085
1086 rcu_read_lock();
1087 for_each_process(p) {
1088 if (same_thread_group(task, p))
1089 continue;
1090
1091 /* do not touch kernel threads or the global init */
1092 if (p->flags & PF_KTHREAD || is_global_init(p))
1093 continue;
1094
1095 task_lock(p);
1096 if (!p->vfork_done && process_shares_mm(p, mm)) {
1097 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1098 task_pid_nr(p), p->comm,
1099 p->signal->oom_score_adj, oom_adj,
1100 task_pid_nr(task), task->comm);
1101 p->signal->oom_score_adj = oom_adj;
1102 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1103 p->signal->oom_score_adj_min = (short)oom_adj;
1104 }
1105 task_unlock(p);
1106 }
1107 rcu_read_unlock();
1108 mmdrop(mm);
1109 }
1110 err_unlock:
1111 mutex_unlock(&oom_adj_mutex);
1112 put_task_struct(task);
1113 return err;
1114 }
1115
1116 /*
1117 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1118 * kernels. The effective policy is defined by oom_score_adj, which has a
1119 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1120 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1121 * Processes that become oom disabled via oom_adj will still be oom disabled
1122 * with this implementation.
1123 *
1124 * oom_adj cannot be removed since existing userspace binaries use it.
1125 */
1126 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1127 size_t count, loff_t *ppos)
1128 {
1129 char buffer[PROC_NUMBUF];
1130 int oom_adj;
1131 int err;
1132
1133 memset(buffer, 0, sizeof(buffer));
1134 if (count > sizeof(buffer) - 1)
1135 count = sizeof(buffer) - 1;
1136 if (copy_from_user(buffer, buf, count)) {
1137 err = -EFAULT;
1138 goto out;
1139 }
1140
1141 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1142 if (err)
1143 goto out;
1144 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1145 oom_adj != OOM_DISABLE) {
1146 err = -EINVAL;
1147 goto out;
1148 }
1149
1150 /*
1151 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1152 * value is always attainable.
1153 */
1154 if (oom_adj == OOM_ADJUST_MAX)
1155 oom_adj = OOM_SCORE_ADJ_MAX;
1156 else
1157 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1158
1159 err = __set_oom_adj(file, oom_adj, true);
1160 out:
1161 return err < 0 ? err : count;
1162 }
1163
1164 static const struct file_operations proc_oom_adj_operations = {
1165 .read = oom_adj_read,
1166 .write = oom_adj_write,
1167 .llseek = generic_file_llseek,
1168 };
1169
1170 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1171 size_t count, loff_t *ppos)
1172 {
1173 struct task_struct *task = get_proc_task(file_inode(file));
1174 char buffer[PROC_NUMBUF];
1175 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1176 size_t len;
1177
1178 if (!task)
1179 return -ESRCH;
1180 oom_score_adj = task->signal->oom_score_adj;
1181 put_task_struct(task);
1182 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1183 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1184 }
1185
1186 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1187 size_t count, loff_t *ppos)
1188 {
1189 char buffer[PROC_NUMBUF];
1190 int oom_score_adj;
1191 int err;
1192
1193 memset(buffer, 0, sizeof(buffer));
1194 if (count > sizeof(buffer) - 1)
1195 count = sizeof(buffer) - 1;
1196 if (copy_from_user(buffer, buf, count)) {
1197 err = -EFAULT;
1198 goto out;
1199 }
1200
1201 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1202 if (err)
1203 goto out;
1204 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1205 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1206 err = -EINVAL;
1207 goto out;
1208 }
1209
1210 err = __set_oom_adj(file, oom_score_adj, false);
1211 out:
1212 return err < 0 ? err : count;
1213 }
1214
1215 static const struct file_operations proc_oom_score_adj_operations = {
1216 .read = oom_score_adj_read,
1217 .write = oom_score_adj_write,
1218 .llseek = default_llseek,
1219 };
1220
1221 #ifdef CONFIG_AUDITSYSCALL
1222 #define TMPBUFLEN 11
1223 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1224 size_t count, loff_t *ppos)
1225 {
1226 struct inode * inode = file_inode(file);
1227 struct task_struct *task = get_proc_task(inode);
1228 ssize_t length;
1229 char tmpbuf[TMPBUFLEN];
1230
1231 if (!task)
1232 return -ESRCH;
1233 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1234 from_kuid(file->f_cred->user_ns,
1235 audit_get_loginuid(task)));
1236 put_task_struct(task);
1237 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1238 }
1239
1240 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1241 size_t count, loff_t *ppos)
1242 {
1243 struct inode * inode = file_inode(file);
1244 uid_t loginuid;
1245 kuid_t kloginuid;
1246 int rv;
1247
1248 rcu_read_lock();
1249 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1250 rcu_read_unlock();
1251 return -EPERM;
1252 }
1253 rcu_read_unlock();
1254
1255 if (*ppos != 0) {
1256 /* No partial writes. */
1257 return -EINVAL;
1258 }
1259
1260 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1261 if (rv < 0)
1262 return rv;
1263
1264 /* is userspace tring to explicitly UNSET the loginuid? */
1265 if (loginuid == AUDIT_UID_UNSET) {
1266 kloginuid = INVALID_UID;
1267 } else {
1268 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1269 if (!uid_valid(kloginuid))
1270 return -EINVAL;
1271 }
1272
1273 rv = audit_set_loginuid(kloginuid);
1274 if (rv < 0)
1275 return rv;
1276 return count;
1277 }
1278
1279 static const struct file_operations proc_loginuid_operations = {
1280 .read = proc_loginuid_read,
1281 .write = proc_loginuid_write,
1282 .llseek = generic_file_llseek,
1283 };
1284
1285 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1286 size_t count, loff_t *ppos)
1287 {
1288 struct inode * inode = file_inode(file);
1289 struct task_struct *task = get_proc_task(inode);
1290 ssize_t length;
1291 char tmpbuf[TMPBUFLEN];
1292
1293 if (!task)
1294 return -ESRCH;
1295 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1296 audit_get_sessionid(task));
1297 put_task_struct(task);
1298 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1299 }
1300
1301 static const struct file_operations proc_sessionid_operations = {
1302 .read = proc_sessionid_read,
1303 .llseek = generic_file_llseek,
1304 };
1305 #endif
1306
1307 #ifdef CONFIG_FAULT_INJECTION
1308 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1309 size_t count, loff_t *ppos)
1310 {
1311 struct task_struct *task = get_proc_task(file_inode(file));
1312 char buffer[PROC_NUMBUF];
1313 size_t len;
1314 int make_it_fail;
1315
1316 if (!task)
1317 return -ESRCH;
1318 make_it_fail = task->make_it_fail;
1319 put_task_struct(task);
1320
1321 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1322
1323 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1324 }
1325
1326 static ssize_t proc_fault_inject_write(struct file * file,
1327 const char __user * buf, size_t count, loff_t *ppos)
1328 {
1329 struct task_struct *task;
1330 char buffer[PROC_NUMBUF];
1331 int make_it_fail;
1332 int rv;
1333
1334 if (!capable(CAP_SYS_RESOURCE))
1335 return -EPERM;
1336 memset(buffer, 0, sizeof(buffer));
1337 if (count > sizeof(buffer) - 1)
1338 count = sizeof(buffer) - 1;
1339 if (copy_from_user(buffer, buf, count))
1340 return -EFAULT;
1341 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1342 if (rv < 0)
1343 return rv;
1344 if (make_it_fail < 0 || make_it_fail > 1)
1345 return -EINVAL;
1346
1347 task = get_proc_task(file_inode(file));
1348 if (!task)
1349 return -ESRCH;
1350 task->make_it_fail = make_it_fail;
1351 put_task_struct(task);
1352
1353 return count;
1354 }
1355
1356 static const struct file_operations proc_fault_inject_operations = {
1357 .read = proc_fault_inject_read,
1358 .write = proc_fault_inject_write,
1359 .llseek = generic_file_llseek,
1360 };
1361
1362 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1363 size_t count, loff_t *ppos)
1364 {
1365 struct task_struct *task;
1366 int err;
1367 unsigned int n;
1368
1369 err = kstrtouint_from_user(buf, count, 0, &n);
1370 if (err)
1371 return err;
1372
1373 task = get_proc_task(file_inode(file));
1374 if (!task)
1375 return -ESRCH;
1376 task->fail_nth = n;
1377 put_task_struct(task);
1378
1379 return count;
1380 }
1381
1382 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1383 size_t count, loff_t *ppos)
1384 {
1385 struct task_struct *task;
1386 char numbuf[PROC_NUMBUF];
1387 ssize_t len;
1388
1389 task = get_proc_task(file_inode(file));
1390 if (!task)
1391 return -ESRCH;
1392 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1393 len = simple_read_from_buffer(buf, count, ppos, numbuf, len);
1394 put_task_struct(task);
1395
1396 return len;
1397 }
1398
1399 static const struct file_operations proc_fail_nth_operations = {
1400 .read = proc_fail_nth_read,
1401 .write = proc_fail_nth_write,
1402 };
1403 #endif
1404
1405
1406 #ifdef CONFIG_SCHED_DEBUG
1407 /*
1408 * Print out various scheduling related per-task fields:
1409 */
1410 static int sched_show(struct seq_file *m, void *v)
1411 {
1412 struct inode *inode = m->private;
1413 struct pid_namespace *ns = inode->i_sb->s_fs_info;
1414 struct task_struct *p;
1415
1416 p = get_proc_task(inode);
1417 if (!p)
1418 return -ESRCH;
1419 proc_sched_show_task(p, ns, m);
1420
1421 put_task_struct(p);
1422
1423 return 0;
1424 }
1425
1426 static ssize_t
1427 sched_write(struct file *file, const char __user *buf,
1428 size_t count, loff_t *offset)
1429 {
1430 struct inode *inode = file_inode(file);
1431 struct task_struct *p;
1432
1433 p = get_proc_task(inode);
1434 if (!p)
1435 return -ESRCH;
1436 proc_sched_set_task(p);
1437
1438 put_task_struct(p);
1439
1440 return count;
1441 }
1442
1443 static int sched_open(struct inode *inode, struct file *filp)
1444 {
1445 return single_open(filp, sched_show, inode);
1446 }
1447
1448 static const struct file_operations proc_pid_sched_operations = {
1449 .open = sched_open,
1450 .read = seq_read,
1451 .write = sched_write,
1452 .llseek = seq_lseek,
1453 .release = single_release,
1454 };
1455
1456 #endif
1457
1458 #ifdef CONFIG_SCHED_AUTOGROUP
1459 /*
1460 * Print out autogroup related information:
1461 */
1462 static int sched_autogroup_show(struct seq_file *m, void *v)
1463 {
1464 struct inode *inode = m->private;
1465 struct task_struct *p;
1466
1467 p = get_proc_task(inode);
1468 if (!p)
1469 return -ESRCH;
1470 proc_sched_autogroup_show_task(p, m);
1471
1472 put_task_struct(p);
1473
1474 return 0;
1475 }
1476
1477 static ssize_t
1478 sched_autogroup_write(struct file *file, const char __user *buf,
1479 size_t count, loff_t *offset)
1480 {
1481 struct inode *inode = file_inode(file);
1482 struct task_struct *p;
1483 char buffer[PROC_NUMBUF];
1484 int nice;
1485 int err;
1486
1487 memset(buffer, 0, sizeof(buffer));
1488 if (count > sizeof(buffer) - 1)
1489 count = sizeof(buffer) - 1;
1490 if (copy_from_user(buffer, buf, count))
1491 return -EFAULT;
1492
1493 err = kstrtoint(strstrip(buffer), 0, &nice);
1494 if (err < 0)
1495 return err;
1496
1497 p = get_proc_task(inode);
1498 if (!p)
1499 return -ESRCH;
1500
1501 err = proc_sched_autogroup_set_nice(p, nice);
1502 if (err)
1503 count = err;
1504
1505 put_task_struct(p);
1506
1507 return count;
1508 }
1509
1510 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1511 {
1512 int ret;
1513
1514 ret = single_open(filp, sched_autogroup_show, NULL);
1515 if (!ret) {
1516 struct seq_file *m = filp->private_data;
1517
1518 m->private = inode;
1519 }
1520 return ret;
1521 }
1522
1523 static const struct file_operations proc_pid_sched_autogroup_operations = {
1524 .open = sched_autogroup_open,
1525 .read = seq_read,
1526 .write = sched_autogroup_write,
1527 .llseek = seq_lseek,
1528 .release = single_release,
1529 };
1530
1531 #endif /* CONFIG_SCHED_AUTOGROUP */
1532
1533 static ssize_t comm_write(struct file *file, const char __user *buf,
1534 size_t count, loff_t *offset)
1535 {
1536 struct inode *inode = file_inode(file);
1537 struct task_struct *p;
1538 char buffer[TASK_COMM_LEN];
1539 const size_t maxlen = sizeof(buffer) - 1;
1540
1541 memset(buffer, 0, sizeof(buffer));
1542 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1543 return -EFAULT;
1544
1545 p = get_proc_task(inode);
1546 if (!p)
1547 return -ESRCH;
1548
1549 if (same_thread_group(current, p))
1550 set_task_comm(p, buffer);
1551 else
1552 count = -EINVAL;
1553
1554 put_task_struct(p);
1555
1556 return count;
1557 }
1558
1559 static int comm_show(struct seq_file *m, void *v)
1560 {
1561 struct inode *inode = m->private;
1562 struct task_struct *p;
1563
1564 p = get_proc_task(inode);
1565 if (!p)
1566 return -ESRCH;
1567
1568 task_lock(p);
1569 seq_printf(m, "%s\n", p->comm);
1570 task_unlock(p);
1571
1572 put_task_struct(p);
1573
1574 return 0;
1575 }
1576
1577 static int comm_open(struct inode *inode, struct file *filp)
1578 {
1579 return single_open(filp, comm_show, inode);
1580 }
1581
1582 static const struct file_operations proc_pid_set_comm_operations = {
1583 .open = comm_open,
1584 .read = seq_read,
1585 .write = comm_write,
1586 .llseek = seq_lseek,
1587 .release = single_release,
1588 };
1589
1590 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1591 {
1592 struct task_struct *task;
1593 struct file *exe_file;
1594
1595 task = get_proc_task(d_inode(dentry));
1596 if (!task)
1597 return -ENOENT;
1598 exe_file = get_task_exe_file(task);
1599 put_task_struct(task);
1600 if (exe_file) {
1601 *exe_path = exe_file->f_path;
1602 path_get(&exe_file->f_path);
1603 fput(exe_file);
1604 return 0;
1605 } else
1606 return -ENOENT;
1607 }
1608
1609 static const char *proc_pid_get_link(struct dentry *dentry,
1610 struct inode *inode,
1611 struct delayed_call *done)
1612 {
1613 struct path path;
1614 int error = -EACCES;
1615
1616 if (!dentry)
1617 return ERR_PTR(-ECHILD);
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 nd_jump_link(&path);
1628 return NULL;
1629 out:
1630 return ERR_PTR(error);
1631 }
1632
1633 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1634 {
1635 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1636 char *pathname;
1637 int len;
1638
1639 if (!tmp)
1640 return -ENOMEM;
1641
1642 pathname = d_path(path, tmp, PAGE_SIZE);
1643 len = PTR_ERR(pathname);
1644 if (IS_ERR(pathname))
1645 goto out;
1646 len = tmp + PAGE_SIZE - 1 - pathname;
1647
1648 if (len > buflen)
1649 len = buflen;
1650 if (copy_to_user(buffer, pathname, len))
1651 len = -EFAULT;
1652 out:
1653 free_page((unsigned long)tmp);
1654 return len;
1655 }
1656
1657 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1658 {
1659 int error = -EACCES;
1660 struct inode *inode = d_inode(dentry);
1661 struct path path;
1662
1663 /* Are we allowed to snoop on the tasks file descriptors? */
1664 if (!proc_fd_access_allowed(inode))
1665 goto out;
1666
1667 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1668 if (error)
1669 goto out;
1670
1671 error = do_proc_readlink(&path, buffer, buflen);
1672 path_put(&path);
1673 out:
1674 return error;
1675 }
1676
1677 const struct inode_operations proc_pid_link_inode_operations = {
1678 .readlink = proc_pid_readlink,
1679 .get_link = proc_pid_get_link,
1680 .setattr = proc_setattr,
1681 };
1682
1683
1684 /* building an inode */
1685
1686 void task_dump_owner(struct task_struct *task, umode_t mode,
1687 kuid_t *ruid, kgid_t *rgid)
1688 {
1689 /* Depending on the state of dumpable compute who should own a
1690 * proc file for a task.
1691 */
1692 const struct cred *cred;
1693 kuid_t uid;
1694 kgid_t gid;
1695
1696 if (unlikely(task->flags & PF_KTHREAD)) {
1697 *ruid = GLOBAL_ROOT_UID;
1698 *rgid = GLOBAL_ROOT_GID;
1699 return;
1700 }
1701
1702 /* Default to the tasks effective ownership */
1703 rcu_read_lock();
1704 cred = __task_cred(task);
1705 uid = cred->euid;
1706 gid = cred->egid;
1707 rcu_read_unlock();
1708
1709 /*
1710 * Before the /proc/pid/status file was created the only way to read
1711 * the effective uid of a /process was to stat /proc/pid. Reading
1712 * /proc/pid/status is slow enough that procps and other packages
1713 * kept stating /proc/pid. To keep the rules in /proc simple I have
1714 * made this apply to all per process world readable and executable
1715 * directories.
1716 */
1717 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1718 struct mm_struct *mm;
1719 task_lock(task);
1720 mm = task->mm;
1721 /* Make non-dumpable tasks owned by some root */
1722 if (mm) {
1723 if (get_dumpable(mm) != SUID_DUMP_USER) {
1724 struct user_namespace *user_ns = mm->user_ns;
1725
1726 uid = make_kuid(user_ns, 0);
1727 if (!uid_valid(uid))
1728 uid = GLOBAL_ROOT_UID;
1729
1730 gid = make_kgid(user_ns, 0);
1731 if (!gid_valid(gid))
1732 gid = GLOBAL_ROOT_GID;
1733 }
1734 } else {
1735 uid = GLOBAL_ROOT_UID;
1736 gid = GLOBAL_ROOT_GID;
1737 }
1738 task_unlock(task);
1739 }
1740 *ruid = uid;
1741 *rgid = gid;
1742 }
1743
1744 struct inode *proc_pid_make_inode(struct super_block * sb,
1745 struct task_struct *task, umode_t mode)
1746 {
1747 struct inode * inode;
1748 struct proc_inode *ei;
1749
1750 /* We need a new inode */
1751
1752 inode = new_inode(sb);
1753 if (!inode)
1754 goto out;
1755
1756 /* Common stuff */
1757 ei = PROC_I(inode);
1758 inode->i_mode = mode;
1759 inode->i_ino = get_next_ino();
1760 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1761 inode->i_op = &proc_def_inode_operations;
1762
1763 /*
1764 * grab the reference to task.
1765 */
1766 ei->pid = get_task_pid(task, PIDTYPE_PID);
1767 if (!ei->pid)
1768 goto out_unlock;
1769
1770 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1771 security_task_to_inode(task, inode);
1772
1773 out:
1774 return inode;
1775
1776 out_unlock:
1777 iput(inode);
1778 return NULL;
1779 }
1780
1781 int pid_getattr(const struct path *path, struct kstat *stat,
1782 u32 request_mask, unsigned int query_flags)
1783 {
1784 struct inode *inode = d_inode(path->dentry);
1785 struct task_struct *task;
1786 struct pid_namespace *pid = path->dentry->d_sb->s_fs_info;
1787
1788 generic_fillattr(inode, stat);
1789
1790 rcu_read_lock();
1791 stat->uid = GLOBAL_ROOT_UID;
1792 stat->gid = GLOBAL_ROOT_GID;
1793 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1794 if (task) {
1795 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1796 rcu_read_unlock();
1797 /*
1798 * This doesn't prevent learning whether PID exists,
1799 * it only makes getattr() consistent with readdir().
1800 */
1801 return -ENOENT;
1802 }
1803 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1804 }
1805 rcu_read_unlock();
1806 return 0;
1807 }
1808
1809 /* dentry stuff */
1810
1811 /*
1812 * Exceptional case: normally we are not allowed to unhash a busy
1813 * directory. In this case, however, we can do it - no aliasing problems
1814 * due to the way we treat inodes.
1815 *
1816 * Rewrite the inode's ownerships here because the owning task may have
1817 * performed a setuid(), etc.
1818 *
1819 */
1820 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1821 {
1822 struct inode *inode;
1823 struct task_struct *task;
1824
1825 if (flags & LOOKUP_RCU)
1826 return -ECHILD;
1827
1828 inode = d_inode(dentry);
1829 task = get_proc_task(inode);
1830
1831 if (task) {
1832 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1833
1834 inode->i_mode &= ~(S_ISUID | S_ISGID);
1835 security_task_to_inode(task, inode);
1836 put_task_struct(task);
1837 return 1;
1838 }
1839 return 0;
1840 }
1841
1842 static inline bool proc_inode_is_dead(struct inode *inode)
1843 {
1844 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1845 }
1846
1847 int pid_delete_dentry(const struct dentry *dentry)
1848 {
1849 /* Is the task we represent dead?
1850 * If so, then don't put the dentry on the lru list,
1851 * kill it immediately.
1852 */
1853 return proc_inode_is_dead(d_inode(dentry));
1854 }
1855
1856 const struct dentry_operations pid_dentry_operations =
1857 {
1858 .d_revalidate = pid_revalidate,
1859 .d_delete = pid_delete_dentry,
1860 };
1861
1862 /* Lookups */
1863
1864 /*
1865 * Fill a directory entry.
1866 *
1867 * If possible create the dcache entry and derive our inode number and
1868 * file type from dcache entry.
1869 *
1870 * Since all of the proc inode numbers are dynamically generated, the inode
1871 * numbers do not exist until the inode is cache. This means creating the
1872 * the dcache entry in readdir is necessary to keep the inode numbers
1873 * reported by readdir in sync with the inode numbers reported
1874 * by stat.
1875 */
1876 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1877 const char *name, int len,
1878 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1879 {
1880 struct dentry *child, *dir = file->f_path.dentry;
1881 struct qstr qname = QSTR_INIT(name, len);
1882 struct inode *inode;
1883 unsigned type;
1884 ino_t ino;
1885
1886 child = d_hash_and_lookup(dir, &qname);
1887 if (!child) {
1888 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1889 child = d_alloc_parallel(dir, &qname, &wq);
1890 if (IS_ERR(child))
1891 goto end_instantiate;
1892 if (d_in_lookup(child)) {
1893 int err = instantiate(d_inode(dir), child, task, ptr);
1894 d_lookup_done(child);
1895 if (err < 0) {
1896 dput(child);
1897 goto end_instantiate;
1898 }
1899 }
1900 }
1901 inode = d_inode(child);
1902 ino = inode->i_ino;
1903 type = inode->i_mode >> 12;
1904 dput(child);
1905 return dir_emit(ctx, name, len, ino, type);
1906
1907 end_instantiate:
1908 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1909 }
1910
1911 /*
1912 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1913 * which represent vma start and end addresses.
1914 */
1915 static int dname_to_vma_addr(struct dentry *dentry,
1916 unsigned long *start, unsigned long *end)
1917 {
1918 const char *str = dentry->d_name.name;
1919 unsigned long long sval, eval;
1920 unsigned int len;
1921
1922 len = _parse_integer(str, 16, &sval);
1923 if (len & KSTRTOX_OVERFLOW)
1924 return -EINVAL;
1925 if (sval != (unsigned long)sval)
1926 return -EINVAL;
1927 str += len;
1928
1929 if (*str != '-')
1930 return -EINVAL;
1931 str++;
1932
1933 len = _parse_integer(str, 16, &eval);
1934 if (len & KSTRTOX_OVERFLOW)
1935 return -EINVAL;
1936 if (eval != (unsigned long)eval)
1937 return -EINVAL;
1938 str += len;
1939
1940 if (*str != '\0')
1941 return -EINVAL;
1942
1943 *start = sval;
1944 *end = eval;
1945
1946 return 0;
1947 }
1948
1949 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1950 {
1951 unsigned long vm_start, vm_end;
1952 bool exact_vma_exists = false;
1953 struct mm_struct *mm = NULL;
1954 struct task_struct *task;
1955 struct inode *inode;
1956 int status = 0;
1957
1958 if (flags & LOOKUP_RCU)
1959 return -ECHILD;
1960
1961 inode = d_inode(dentry);
1962 task = get_proc_task(inode);
1963 if (!task)
1964 goto out_notask;
1965
1966 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1967 if (IS_ERR_OR_NULL(mm))
1968 goto out;
1969
1970 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1971 down_read(&mm->mmap_sem);
1972 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1973 up_read(&mm->mmap_sem);
1974 }
1975
1976 mmput(mm);
1977
1978 if (exact_vma_exists) {
1979 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1980
1981 security_task_to_inode(task, inode);
1982 status = 1;
1983 }
1984
1985 out:
1986 put_task_struct(task);
1987
1988 out_notask:
1989 return status;
1990 }
1991
1992 static const struct dentry_operations tid_map_files_dentry_operations = {
1993 .d_revalidate = map_files_d_revalidate,
1994 .d_delete = pid_delete_dentry,
1995 };
1996
1997 static int map_files_get_link(struct dentry *dentry, struct path *path)
1998 {
1999 unsigned long vm_start, vm_end;
2000 struct vm_area_struct *vma;
2001 struct task_struct *task;
2002 struct mm_struct *mm;
2003 int rc;
2004
2005 rc = -ENOENT;
2006 task = get_proc_task(d_inode(dentry));
2007 if (!task)
2008 goto out;
2009
2010 mm = get_task_mm(task);
2011 put_task_struct(task);
2012 if (!mm)
2013 goto out;
2014
2015 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2016 if (rc)
2017 goto out_mmput;
2018
2019 rc = -ENOENT;
2020 down_read(&mm->mmap_sem);
2021 vma = find_exact_vma(mm, vm_start, vm_end);
2022 if (vma && vma->vm_file) {
2023 *path = vma->vm_file->f_path;
2024 path_get(path);
2025 rc = 0;
2026 }
2027 up_read(&mm->mmap_sem);
2028
2029 out_mmput:
2030 mmput(mm);
2031 out:
2032 return rc;
2033 }
2034
2035 struct map_files_info {
2036 unsigned long start;
2037 unsigned long end;
2038 fmode_t mode;
2039 };
2040
2041 /*
2042 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2043 * symlinks may be used to bypass permissions on ancestor directories in the
2044 * path to the file in question.
2045 */
2046 static const char *
2047 proc_map_files_get_link(struct dentry *dentry,
2048 struct inode *inode,
2049 struct delayed_call *done)
2050 {
2051 if (!capable(CAP_SYS_ADMIN))
2052 return ERR_PTR(-EPERM);
2053
2054 return proc_pid_get_link(dentry, inode, done);
2055 }
2056
2057 /*
2058 * Identical to proc_pid_link_inode_operations except for get_link()
2059 */
2060 static const struct inode_operations proc_map_files_link_inode_operations = {
2061 .readlink = proc_pid_readlink,
2062 .get_link = proc_map_files_get_link,
2063 .setattr = proc_setattr,
2064 };
2065
2066 static int
2067 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2068 struct task_struct *task, const void *ptr)
2069 {
2070 fmode_t mode = (fmode_t)(unsigned long)ptr;
2071 struct proc_inode *ei;
2072 struct inode *inode;
2073
2074 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
2075 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2076 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2077 if (!inode)
2078 return -ENOENT;
2079
2080 ei = PROC_I(inode);
2081 ei->op.proc_get_link = map_files_get_link;
2082
2083 inode->i_op = &proc_map_files_link_inode_operations;
2084 inode->i_size = 64;
2085
2086 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2087 d_add(dentry, inode);
2088
2089 return 0;
2090 }
2091
2092 static struct dentry *proc_map_files_lookup(struct inode *dir,
2093 struct dentry *dentry, unsigned int flags)
2094 {
2095 unsigned long vm_start, vm_end;
2096 struct vm_area_struct *vma;
2097 struct task_struct *task;
2098 int result;
2099 struct mm_struct *mm;
2100
2101 result = -ENOENT;
2102 task = get_proc_task(dir);
2103 if (!task)
2104 goto out;
2105
2106 result = -EACCES;
2107 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2108 goto out_put_task;
2109
2110 result = -ENOENT;
2111 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2112 goto out_put_task;
2113
2114 mm = get_task_mm(task);
2115 if (!mm)
2116 goto out_put_task;
2117
2118 down_read(&mm->mmap_sem);
2119 vma = find_exact_vma(mm, vm_start, vm_end);
2120 if (!vma)
2121 goto out_no_vma;
2122
2123 if (vma->vm_file)
2124 result = proc_map_files_instantiate(dir, dentry, task,
2125 (void *)(unsigned long)vma->vm_file->f_mode);
2126
2127 out_no_vma:
2128 up_read(&mm->mmap_sem);
2129 mmput(mm);
2130 out_put_task:
2131 put_task_struct(task);
2132 out:
2133 return ERR_PTR(result);
2134 }
2135
2136 static const struct inode_operations proc_map_files_inode_operations = {
2137 .lookup = proc_map_files_lookup,
2138 .permission = proc_fd_permission,
2139 .setattr = proc_setattr,
2140 };
2141
2142 static int
2143 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2144 {
2145 struct vm_area_struct *vma;
2146 struct task_struct *task;
2147 struct mm_struct *mm;
2148 unsigned long nr_files, pos, i;
2149 struct flex_array *fa = NULL;
2150 struct map_files_info info;
2151 struct map_files_info *p;
2152 int ret;
2153
2154 ret = -ENOENT;
2155 task = get_proc_task(file_inode(file));
2156 if (!task)
2157 goto out;
2158
2159 ret = -EACCES;
2160 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2161 goto out_put_task;
2162
2163 ret = 0;
2164 if (!dir_emit_dots(file, ctx))
2165 goto out_put_task;
2166
2167 mm = get_task_mm(task);
2168 if (!mm)
2169 goto out_put_task;
2170 down_read(&mm->mmap_sem);
2171
2172 nr_files = 0;
2173
2174 /*
2175 * We need two passes here:
2176 *
2177 * 1) Collect vmas of mapped files with mmap_sem taken
2178 * 2) Release mmap_sem and instantiate entries
2179 *
2180 * otherwise we get lockdep complained, since filldir()
2181 * routine might require mmap_sem taken in might_fault().
2182 */
2183
2184 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2185 if (vma->vm_file && ++pos > ctx->pos)
2186 nr_files++;
2187 }
2188
2189 if (nr_files) {
2190 fa = flex_array_alloc(sizeof(info), nr_files,
2191 GFP_KERNEL);
2192 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2193 GFP_KERNEL)) {
2194 ret = -ENOMEM;
2195 if (fa)
2196 flex_array_free(fa);
2197 up_read(&mm->mmap_sem);
2198 mmput(mm);
2199 goto out_put_task;
2200 }
2201 for (i = 0, vma = mm->mmap, pos = 2; vma;
2202 vma = vma->vm_next) {
2203 if (!vma->vm_file)
2204 continue;
2205 if (++pos <= ctx->pos)
2206 continue;
2207
2208 info.start = vma->vm_start;
2209 info.end = vma->vm_end;
2210 info.mode = vma->vm_file->f_mode;
2211 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2212 BUG();
2213 }
2214 }
2215 up_read(&mm->mmap_sem);
2216
2217 for (i = 0; i < nr_files; i++) {
2218 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2219 unsigned int len;
2220
2221 p = flex_array_get(fa, i);
2222 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2223 if (!proc_fill_cache(file, ctx,
2224 buf, len,
2225 proc_map_files_instantiate,
2226 task,
2227 (void *)(unsigned long)p->mode))
2228 break;
2229 ctx->pos++;
2230 }
2231 if (fa)
2232 flex_array_free(fa);
2233 mmput(mm);
2234
2235 out_put_task:
2236 put_task_struct(task);
2237 out:
2238 return ret;
2239 }
2240
2241 static const struct file_operations proc_map_files_operations = {
2242 .read = generic_read_dir,
2243 .iterate_shared = proc_map_files_readdir,
2244 .llseek = generic_file_llseek,
2245 };
2246
2247 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2248 struct timers_private {
2249 struct pid *pid;
2250 struct task_struct *task;
2251 struct sighand_struct *sighand;
2252 struct pid_namespace *ns;
2253 unsigned long flags;
2254 };
2255
2256 static void *timers_start(struct seq_file *m, loff_t *pos)
2257 {
2258 struct timers_private *tp = m->private;
2259
2260 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2261 if (!tp->task)
2262 return ERR_PTR(-ESRCH);
2263
2264 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2265 if (!tp->sighand)
2266 return ERR_PTR(-ESRCH);
2267
2268 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2269 }
2270
2271 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2272 {
2273 struct timers_private *tp = m->private;
2274 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2275 }
2276
2277 static void timers_stop(struct seq_file *m, void *v)
2278 {
2279 struct timers_private *tp = m->private;
2280
2281 if (tp->sighand) {
2282 unlock_task_sighand(tp->task, &tp->flags);
2283 tp->sighand = NULL;
2284 }
2285
2286 if (tp->task) {
2287 put_task_struct(tp->task);
2288 tp->task = NULL;
2289 }
2290 }
2291
2292 static int show_timer(struct seq_file *m, void *v)
2293 {
2294 struct k_itimer *timer;
2295 struct timers_private *tp = m->private;
2296 int notify;
2297 static const char * const nstr[] = {
2298 [SIGEV_SIGNAL] = "signal",
2299 [SIGEV_NONE] = "none",
2300 [SIGEV_THREAD] = "thread",
2301 };
2302
2303 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2304 notify = timer->it_sigev_notify;
2305
2306 seq_printf(m, "ID: %d\n", timer->it_id);
2307 seq_printf(m, "signal: %d/%px\n",
2308 timer->sigq->info.si_signo,
2309 timer->sigq->info.si_value.sival_ptr);
2310 seq_printf(m, "notify: %s/%s.%d\n",
2311 nstr[notify & ~SIGEV_THREAD_ID],
2312 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2313 pid_nr_ns(timer->it_pid, tp->ns));
2314 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2315
2316 return 0;
2317 }
2318
2319 static const struct seq_operations proc_timers_seq_ops = {
2320 .start = timers_start,
2321 .next = timers_next,
2322 .stop = timers_stop,
2323 .show = show_timer,
2324 };
2325
2326 static int proc_timers_open(struct inode *inode, struct file *file)
2327 {
2328 struct timers_private *tp;
2329
2330 tp = __seq_open_private(file, &proc_timers_seq_ops,
2331 sizeof(struct timers_private));
2332 if (!tp)
2333 return -ENOMEM;
2334
2335 tp->pid = proc_pid(inode);
2336 tp->ns = inode->i_sb->s_fs_info;
2337 return 0;
2338 }
2339
2340 static const struct file_operations proc_timers_operations = {
2341 .open = proc_timers_open,
2342 .read = seq_read,
2343 .llseek = seq_lseek,
2344 .release = seq_release_private,
2345 };
2346 #endif
2347
2348 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2349 size_t count, loff_t *offset)
2350 {
2351 struct inode *inode = file_inode(file);
2352 struct task_struct *p;
2353 u64 slack_ns;
2354 int err;
2355
2356 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2357 if (err < 0)
2358 return err;
2359
2360 p = get_proc_task(inode);
2361 if (!p)
2362 return -ESRCH;
2363
2364 if (p != current) {
2365 if (!capable(CAP_SYS_NICE)) {
2366 count = -EPERM;
2367 goto out;
2368 }
2369
2370 err = security_task_setscheduler(p);
2371 if (err) {
2372 count = err;
2373 goto out;
2374 }
2375 }
2376
2377 task_lock(p);
2378 if (slack_ns == 0)
2379 p->timer_slack_ns = p->default_timer_slack_ns;
2380 else
2381 p->timer_slack_ns = slack_ns;
2382 task_unlock(p);
2383
2384 out:
2385 put_task_struct(p);
2386
2387 return count;
2388 }
2389
2390 static int timerslack_ns_show(struct seq_file *m, void *v)
2391 {
2392 struct inode *inode = m->private;
2393 struct task_struct *p;
2394 int err = 0;
2395
2396 p = get_proc_task(inode);
2397 if (!p)
2398 return -ESRCH;
2399
2400 if (p != current) {
2401
2402 if (!capable(CAP_SYS_NICE)) {
2403 err = -EPERM;
2404 goto out;
2405 }
2406 err = security_task_getscheduler(p);
2407 if (err)
2408 goto out;
2409 }
2410
2411 task_lock(p);
2412 seq_printf(m, "%llu\n", p->timer_slack_ns);
2413 task_unlock(p);
2414
2415 out:
2416 put_task_struct(p);
2417
2418 return err;
2419 }
2420
2421 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2422 {
2423 return single_open(filp, timerslack_ns_show, inode);
2424 }
2425
2426 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2427 .open = timerslack_ns_open,
2428 .read = seq_read,
2429 .write = timerslack_ns_write,
2430 .llseek = seq_lseek,
2431 .release = single_release,
2432 };
2433
2434 static int proc_pident_instantiate(struct inode *dir,
2435 struct dentry *dentry, struct task_struct *task, const void *ptr)
2436 {
2437 const struct pid_entry *p = ptr;
2438 struct inode *inode;
2439 struct proc_inode *ei;
2440
2441 inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
2442 if (!inode)
2443 goto out;
2444
2445 ei = PROC_I(inode);
2446 if (S_ISDIR(inode->i_mode))
2447 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2448 if (p->iop)
2449 inode->i_op = p->iop;
2450 if (p->fop)
2451 inode->i_fop = p->fop;
2452 ei->op = p->op;
2453 d_set_d_op(dentry, &pid_dentry_operations);
2454 d_add(dentry, inode);
2455 /* Close the race of the process dying before we return the dentry */
2456 if (pid_revalidate(dentry, 0))
2457 return 0;
2458 out:
2459 return -ENOENT;
2460 }
2461
2462 static struct dentry *proc_pident_lookup(struct inode *dir,
2463 struct dentry *dentry,
2464 const struct pid_entry *ents,
2465 unsigned int nents)
2466 {
2467 int error;
2468 struct task_struct *task = get_proc_task(dir);
2469 const struct pid_entry *p, *last;
2470
2471 error = -ENOENT;
2472
2473 if (!task)
2474 goto out_no_task;
2475
2476 /*
2477 * Yes, it does not scale. And it should not. Don't add
2478 * new entries into /proc/<tgid>/ without very good reasons.
2479 */
2480 last = &ents[nents];
2481 for (p = ents; p < last; p++) {
2482 if (p->len != dentry->d_name.len)
2483 continue;
2484 if (!memcmp(dentry->d_name.name, p->name, p->len))
2485 break;
2486 }
2487 if (p >= last)
2488 goto out;
2489
2490 error = proc_pident_instantiate(dir, dentry, task, p);
2491 out:
2492 put_task_struct(task);
2493 out_no_task:
2494 return ERR_PTR(error);
2495 }
2496
2497 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2498 const struct pid_entry *ents, unsigned int nents)
2499 {
2500 struct task_struct *task = get_proc_task(file_inode(file));
2501 const struct pid_entry *p;
2502
2503 if (!task)
2504 return -ENOENT;
2505
2506 if (!dir_emit_dots(file, ctx))
2507 goto out;
2508
2509 if (ctx->pos >= nents + 2)
2510 goto out;
2511
2512 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2513 if (!proc_fill_cache(file, ctx, p->name, p->len,
2514 proc_pident_instantiate, task, p))
2515 break;
2516 ctx->pos++;
2517 }
2518 out:
2519 put_task_struct(task);
2520 return 0;
2521 }
2522
2523 #ifdef CONFIG_SECURITY
2524 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2525 size_t count, loff_t *ppos)
2526 {
2527 struct inode * inode = file_inode(file);
2528 char *p = NULL;
2529 ssize_t length;
2530 struct task_struct *task = get_proc_task(inode);
2531
2532 if (!task)
2533 return -ESRCH;
2534
2535 length = security_getprocattr(task,
2536 (char*)file->f_path.dentry->d_name.name,
2537 &p);
2538 put_task_struct(task);
2539 if (length > 0)
2540 length = simple_read_from_buffer(buf, count, ppos, p, length);
2541 kfree(p);
2542 return length;
2543 }
2544
2545 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2546 size_t count, loff_t *ppos)
2547 {
2548 struct inode * inode = file_inode(file);
2549 void *page;
2550 ssize_t length;
2551 struct task_struct *task = get_proc_task(inode);
2552
2553 length = -ESRCH;
2554 if (!task)
2555 goto out_no_task;
2556
2557 /* A task may only write its own attributes. */
2558 length = -EACCES;
2559 if (current != task)
2560 goto out;
2561
2562 if (count > PAGE_SIZE)
2563 count = PAGE_SIZE;
2564
2565 /* No partial writes. */
2566 length = -EINVAL;
2567 if (*ppos != 0)
2568 goto out;
2569
2570 page = memdup_user(buf, count);
2571 if (IS_ERR(page)) {
2572 length = PTR_ERR(page);
2573 goto out;
2574 }
2575
2576 /* Guard against adverse ptrace interaction */
2577 length = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2578 if (length < 0)
2579 goto out_free;
2580
2581 length = security_setprocattr(file->f_path.dentry->d_name.name,
2582 page, count);
2583 mutex_unlock(¤t->signal->cred_guard_mutex);
2584 out_free:
2585 kfree(page);
2586 out:
2587 put_task_struct(task);
2588 out_no_task:
2589 return length;
2590 }
2591
2592 static const struct file_operations proc_pid_attr_operations = {
2593 .read = proc_pid_attr_read,
2594 .write = proc_pid_attr_write,
2595 .llseek = generic_file_llseek,
2596 };
2597
2598 static const struct pid_entry attr_dir_stuff[] = {
2599 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2600 REG("prev", S_IRUGO, proc_pid_attr_operations),
2601 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2602 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2603 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2604 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2605 };
2606
2607 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2608 {
2609 return proc_pident_readdir(file, ctx,
2610 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2611 }
2612
2613 static const struct file_operations proc_attr_dir_operations = {
2614 .read = generic_read_dir,
2615 .iterate_shared = proc_attr_dir_readdir,
2616 .llseek = generic_file_llseek,
2617 };
2618
2619 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2620 struct dentry *dentry, unsigned int flags)
2621 {
2622 return proc_pident_lookup(dir, dentry,
2623 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2624 }
2625
2626 static const struct inode_operations proc_attr_dir_inode_operations = {
2627 .lookup = proc_attr_dir_lookup,
2628 .getattr = pid_getattr,
2629 .setattr = proc_setattr,
2630 };
2631
2632 #endif
2633
2634 #ifdef CONFIG_ELF_CORE
2635 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2636 size_t count, loff_t *ppos)
2637 {
2638 struct task_struct *task = get_proc_task(file_inode(file));
2639 struct mm_struct *mm;
2640 char buffer[PROC_NUMBUF];
2641 size_t len;
2642 int ret;
2643
2644 if (!task)
2645 return -ESRCH;
2646
2647 ret = 0;
2648 mm = get_task_mm(task);
2649 if (mm) {
2650 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2651 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2652 MMF_DUMP_FILTER_SHIFT));
2653 mmput(mm);
2654 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2655 }
2656
2657 put_task_struct(task);
2658
2659 return ret;
2660 }
2661
2662 static ssize_t proc_coredump_filter_write(struct file *file,
2663 const char __user *buf,
2664 size_t count,
2665 loff_t *ppos)
2666 {
2667 struct task_struct *task;
2668 struct mm_struct *mm;
2669 unsigned int val;
2670 int ret;
2671 int i;
2672 unsigned long mask;
2673
2674 ret = kstrtouint_from_user(buf, count, 0, &val);
2675 if (ret < 0)
2676 return ret;
2677
2678 ret = -ESRCH;
2679 task = get_proc_task(file_inode(file));
2680 if (!task)
2681 goto out_no_task;
2682
2683 mm = get_task_mm(task);
2684 if (!mm)
2685 goto out_no_mm;
2686 ret = 0;
2687
2688 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2689 if (val & mask)
2690 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2691 else
2692 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2693 }
2694
2695 mmput(mm);
2696 out_no_mm:
2697 put_task_struct(task);
2698 out_no_task:
2699 if (ret < 0)
2700 return ret;
2701 return count;
2702 }
2703
2704 static const struct file_operations proc_coredump_filter_operations = {
2705 .read = proc_coredump_filter_read,
2706 .write = proc_coredump_filter_write,
2707 .llseek = generic_file_llseek,
2708 };
2709 #endif
2710
2711 #ifdef CONFIG_TASK_IO_ACCOUNTING
2712 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2713 {
2714 struct task_io_accounting acct = task->ioac;
2715 unsigned long flags;
2716 int result;
2717
2718 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2719 if (result)
2720 return result;
2721
2722 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2723 result = -EACCES;
2724 goto out_unlock;
2725 }
2726
2727 if (whole && lock_task_sighand(task, &flags)) {
2728 struct task_struct *t = task;
2729
2730 task_io_accounting_add(&acct, &task->signal->ioac);
2731 while_each_thread(task, t)
2732 task_io_accounting_add(&acct, &t->ioac);
2733
2734 unlock_task_sighand(task, &flags);
2735 }
2736 seq_printf(m,
2737 "rchar: %llu\n"
2738 "wchar: %llu\n"
2739 "syscr: %llu\n"
2740 "syscw: %llu\n"
2741 "read_bytes: %llu\n"
2742 "write_bytes: %llu\n"
2743 "cancelled_write_bytes: %llu\n",
2744 (unsigned long long)acct.rchar,
2745 (unsigned long long)acct.wchar,
2746 (unsigned long long)acct.syscr,
2747 (unsigned long long)acct.syscw,
2748 (unsigned long long)acct.read_bytes,
2749 (unsigned long long)acct.write_bytes,
2750 (unsigned long long)acct.cancelled_write_bytes);
2751 result = 0;
2752
2753 out_unlock:
2754 mutex_unlock(&task->signal->cred_guard_mutex);
2755 return result;
2756 }
2757
2758 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2759 struct pid *pid, struct task_struct *task)
2760 {
2761 return do_io_accounting(task, m, 0);
2762 }
2763
2764 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2765 struct pid *pid, struct task_struct *task)
2766 {
2767 return do_io_accounting(task, m, 1);
2768 }
2769 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2770
2771 #ifdef CONFIG_USER_NS
2772 static int proc_id_map_open(struct inode *inode, struct file *file,
2773 const struct seq_operations *seq_ops)
2774 {
2775 struct user_namespace *ns = NULL;
2776 struct task_struct *task;
2777 struct seq_file *seq;
2778 int ret = -EINVAL;
2779
2780 task = get_proc_task(inode);
2781 if (task) {
2782 rcu_read_lock();
2783 ns = get_user_ns(task_cred_xxx(task, user_ns));
2784 rcu_read_unlock();
2785 put_task_struct(task);
2786 }
2787 if (!ns)
2788 goto err;
2789
2790 ret = seq_open(file, seq_ops);
2791 if (ret)
2792 goto err_put_ns;
2793
2794 seq = file->private_data;
2795 seq->private = ns;
2796
2797 return 0;
2798 err_put_ns:
2799 put_user_ns(ns);
2800 err:
2801 return ret;
2802 }
2803
2804 static int proc_id_map_release(struct inode *inode, struct file *file)
2805 {
2806 struct seq_file *seq = file->private_data;
2807 struct user_namespace *ns = seq->private;
2808 put_user_ns(ns);
2809 return seq_release(inode, file);
2810 }
2811
2812 static int proc_uid_map_open(struct inode *inode, struct file *file)
2813 {
2814 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2815 }
2816
2817 static int proc_gid_map_open(struct inode *inode, struct file *file)
2818 {
2819 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2820 }
2821
2822 static int proc_projid_map_open(struct inode *inode, struct file *file)
2823 {
2824 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2825 }
2826
2827 static const struct file_operations proc_uid_map_operations = {
2828 .open = proc_uid_map_open,
2829 .write = proc_uid_map_write,
2830 .read = seq_read,
2831 .llseek = seq_lseek,
2832 .release = proc_id_map_release,
2833 };
2834
2835 static const struct file_operations proc_gid_map_operations = {
2836 .open = proc_gid_map_open,
2837 .write = proc_gid_map_write,
2838 .read = seq_read,
2839 .llseek = seq_lseek,
2840 .release = proc_id_map_release,
2841 };
2842
2843 static const struct file_operations proc_projid_map_operations = {
2844 .open = proc_projid_map_open,
2845 .write = proc_projid_map_write,
2846 .read = seq_read,
2847 .llseek = seq_lseek,
2848 .release = proc_id_map_release,
2849 };
2850
2851 static int proc_setgroups_open(struct inode *inode, struct file *file)
2852 {
2853 struct user_namespace *ns = NULL;
2854 struct task_struct *task;
2855 int ret;
2856
2857 ret = -ESRCH;
2858 task = get_proc_task(inode);
2859 if (task) {
2860 rcu_read_lock();
2861 ns = get_user_ns(task_cred_xxx(task, user_ns));
2862 rcu_read_unlock();
2863 put_task_struct(task);
2864 }
2865 if (!ns)
2866 goto err;
2867
2868 if (file->f_mode & FMODE_WRITE) {
2869 ret = -EACCES;
2870 if (!ns_capable(ns, CAP_SYS_ADMIN))
2871 goto err_put_ns;
2872 }
2873
2874 ret = single_open(file, &proc_setgroups_show, ns);
2875 if (ret)
2876 goto err_put_ns;
2877
2878 return 0;
2879 err_put_ns:
2880 put_user_ns(ns);
2881 err:
2882 return ret;
2883 }
2884
2885 static int proc_setgroups_release(struct inode *inode, struct file *file)
2886 {
2887 struct seq_file *seq = file->private_data;
2888 struct user_namespace *ns = seq->private;
2889 int ret = single_release(inode, file);
2890 put_user_ns(ns);
2891 return ret;
2892 }
2893
2894 static const struct file_operations proc_setgroups_operations = {
2895 .open = proc_setgroups_open,
2896 .write = proc_setgroups_write,
2897 .read = seq_read,
2898 .llseek = seq_lseek,
2899 .release = proc_setgroups_release,
2900 };
2901 #endif /* CONFIG_USER_NS */
2902
2903 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2904 struct pid *pid, struct task_struct *task)
2905 {
2906 int err = lock_trace(task);
2907 if (!err) {
2908 seq_printf(m, "%08x\n", task->personality);
2909 unlock_trace(task);
2910 }
2911 return err;
2912 }
2913
2914 #ifdef CONFIG_LIVEPATCH
2915 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2916 struct pid *pid, struct task_struct *task)
2917 {
2918 seq_printf(m, "%d\n", task->patch_state);
2919 return 0;
2920 }
2921 #endif /* CONFIG_LIVEPATCH */
2922
2923 /*
2924 * Thread groups
2925 */
2926 static const struct file_operations proc_task_operations;
2927 static const struct inode_operations proc_task_inode_operations;
2928
2929 static const struct pid_entry tgid_base_stuff[] = {
2930 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2931 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2932 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2933 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2934 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2935 #ifdef CONFIG_NET
2936 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2937 #endif
2938 REG("environ", S_IRUSR, proc_environ_operations),
2939 REG("auxv", S_IRUSR, proc_auxv_operations),
2940 ONE("status", S_IRUGO, proc_pid_status),
2941 ONE("personality", S_IRUSR, proc_pid_personality),
2942 ONE("limits", S_IRUGO, proc_pid_limits),
2943 #ifdef CONFIG_SCHED_DEBUG
2944 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2945 #endif
2946 #ifdef CONFIG_SCHED_AUTOGROUP
2947 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2948 #endif
2949 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2950 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2951 ONE("syscall", S_IRUSR, proc_pid_syscall),
2952 #endif
2953 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2954 ONE("stat", S_IRUGO, proc_tgid_stat),
2955 ONE("statm", S_IRUGO, proc_pid_statm),
2956 REG("maps", S_IRUGO, proc_pid_maps_operations),
2957 #ifdef CONFIG_NUMA
2958 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2959 #endif
2960 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2961 LNK("cwd", proc_cwd_link),
2962 LNK("root", proc_root_link),
2963 LNK("exe", proc_exe_link),
2964 REG("mounts", S_IRUGO, proc_mounts_operations),
2965 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2966 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2967 #ifdef CONFIG_PROC_PAGE_MONITOR
2968 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2969 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2970 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
2971 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2972 #endif
2973 #ifdef CONFIG_SECURITY
2974 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2975 #endif
2976 #ifdef CONFIG_KALLSYMS
2977 ONE("wchan", S_IRUGO, proc_pid_wchan),
2978 #endif
2979 #ifdef CONFIG_STACKTRACE
2980 ONE("stack", S_IRUSR, proc_pid_stack),
2981 #endif
2982 #ifdef CONFIG_SCHED_INFO
2983 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2984 #endif
2985 #ifdef CONFIG_LATENCYTOP
2986 REG("latency", S_IRUGO, proc_lstats_operations),
2987 #endif
2988 #ifdef CONFIG_PROC_PID_CPUSET
2989 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2990 #endif
2991 #ifdef CONFIG_CGROUPS
2992 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2993 #endif
2994 ONE("oom_score", S_IRUGO, proc_oom_score),
2995 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2996 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2997 #ifdef CONFIG_AUDITSYSCALL
2998 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2999 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3000 #endif
3001 #ifdef CONFIG_FAULT_INJECTION
3002 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3003 REG("fail-nth", 0644, proc_fail_nth_operations),
3004 #endif
3005 #ifdef CONFIG_ELF_CORE
3006 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3007 #endif
3008 #ifdef CONFIG_TASK_IO_ACCOUNTING
3009 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3010 #endif
3011 #ifdef CONFIG_HARDWALL
3012 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3013 #endif
3014 #ifdef CONFIG_USER_NS
3015 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3016 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3017 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3018 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3019 #endif
3020 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3021 REG("timers", S_IRUGO, proc_timers_operations),
3022 #endif
3023 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3024 #ifdef CONFIG_LIVEPATCH
3025 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3026 #endif
3027 };
3028
3029 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3030 {
3031 return proc_pident_readdir(file, ctx,
3032 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3033 }
3034
3035 static const struct file_operations proc_tgid_base_operations = {
3036 .read = generic_read_dir,
3037 .iterate_shared = proc_tgid_base_readdir,
3038 .llseek = generic_file_llseek,
3039 };
3040
3041 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3042 {
3043 return proc_pident_lookup(dir, dentry,
3044 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3045 }
3046
3047 static const struct inode_operations proc_tgid_base_inode_operations = {
3048 .lookup = proc_tgid_base_lookup,
3049 .getattr = pid_getattr,
3050 .setattr = proc_setattr,
3051 .permission = proc_pid_permission,
3052 };
3053
3054 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3055 {
3056 struct dentry *dentry, *leader, *dir;
3057 char buf[10 + 1];
3058 struct qstr name;
3059
3060 name.name = buf;
3061 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3062 /* no ->d_hash() rejects on procfs */
3063 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3064 if (dentry) {
3065 d_invalidate(dentry);
3066 dput(dentry);
3067 }
3068
3069 if (pid == tgid)
3070 return;
3071
3072 name.name = buf;
3073 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3074 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3075 if (!leader)
3076 goto out;
3077
3078 name.name = "task";
3079 name.len = strlen(name.name);
3080 dir = d_hash_and_lookup(leader, &name);
3081 if (!dir)
3082 goto out_put_leader;
3083
3084 name.name = buf;
3085 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3086 dentry = d_hash_and_lookup(dir, &name);
3087 if (dentry) {
3088 d_invalidate(dentry);
3089 dput(dentry);
3090 }
3091
3092 dput(dir);
3093 out_put_leader:
3094 dput(leader);
3095 out:
3096 return;
3097 }
3098
3099 /**
3100 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3101 * @task: task that should be flushed.
3102 *
3103 * When flushing dentries from proc, one needs to flush them from global
3104 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3105 * in. This call is supposed to do all of this job.
3106 *
3107 * Looks in the dcache for
3108 * /proc/@pid
3109 * /proc/@tgid/task/@pid
3110 * if either directory is present flushes it and all of it'ts children
3111 * from the dcache.
3112 *
3113 * It is safe and reasonable to cache /proc entries for a task until
3114 * that task exits. After that they just clog up the dcache with
3115 * useless entries, possibly causing useful dcache entries to be
3116 * flushed instead. This routine is proved to flush those useless
3117 * dcache entries at process exit time.
3118 *
3119 * NOTE: This routine is just an optimization so it does not guarantee
3120 * that no dcache entries will exist at process exit time it
3121 * just makes it very unlikely that any will persist.
3122 */
3123
3124 void proc_flush_task(struct task_struct *task)
3125 {
3126 int i;
3127 struct pid *pid, *tgid;
3128 struct upid *upid;
3129
3130 pid = task_pid(task);
3131 tgid = task_tgid(task);
3132
3133 for (i = 0; i <= pid->level; i++) {
3134 upid = &pid->numbers[i];
3135 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3136 tgid->numbers[i].nr);
3137 }
3138 }
3139
3140 static int proc_pid_instantiate(struct inode *dir,
3141 struct dentry * dentry,
3142 struct task_struct *task, const void *ptr)
3143 {
3144 struct inode *inode;
3145
3146 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3147 if (!inode)
3148 goto out;
3149
3150 inode->i_op = &proc_tgid_base_inode_operations;
3151 inode->i_fop = &proc_tgid_base_operations;
3152 inode->i_flags|=S_IMMUTABLE;
3153
3154 set_nlink(inode, nlink_tgid);
3155
3156 d_set_d_op(dentry, &pid_dentry_operations);
3157
3158 d_add(dentry, inode);
3159 /* Close the race of the process dying before we return the dentry */
3160 if (pid_revalidate(dentry, 0))
3161 return 0;
3162 out:
3163 return -ENOENT;
3164 }
3165
3166 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3167 {
3168 int result = -ENOENT;
3169 struct task_struct *task;
3170 unsigned tgid;
3171 struct pid_namespace *ns;
3172
3173 tgid = name_to_int(&dentry->d_name);
3174 if (tgid == ~0U)
3175 goto out;
3176
3177 ns = dentry->d_sb->s_fs_info;
3178 rcu_read_lock();
3179 task = find_task_by_pid_ns(tgid, ns);
3180 if (task)
3181 get_task_struct(task);
3182 rcu_read_unlock();
3183 if (!task)
3184 goto out;
3185
3186 result = proc_pid_instantiate(dir, dentry, task, NULL);
3187 put_task_struct(task);
3188 out:
3189 return ERR_PTR(result);
3190 }
3191
3192 /*
3193 * Find the first task with tgid >= tgid
3194 *
3195 */
3196 struct tgid_iter {
3197 unsigned int tgid;
3198 struct task_struct *task;
3199 };
3200 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3201 {
3202 struct pid *pid;
3203
3204 if (iter.task)
3205 put_task_struct(iter.task);
3206 rcu_read_lock();
3207 retry:
3208 iter.task = NULL;
3209 pid = find_ge_pid(iter.tgid, ns);
3210 if (pid) {
3211 iter.tgid = pid_nr_ns(pid, ns);
3212 iter.task = pid_task(pid, PIDTYPE_PID);
3213 /* What we to know is if the pid we have find is the
3214 * pid of a thread_group_leader. Testing for task
3215 * being a thread_group_leader is the obvious thing
3216 * todo but there is a window when it fails, due to
3217 * the pid transfer logic in de_thread.
3218 *
3219 * So we perform the straight forward test of seeing
3220 * if the pid we have found is the pid of a thread
3221 * group leader, and don't worry if the task we have
3222 * found doesn't happen to be a thread group leader.
3223 * As we don't care in the case of readdir.
3224 */
3225 if (!iter.task || !has_group_leader_pid(iter.task)) {
3226 iter.tgid += 1;
3227 goto retry;
3228 }
3229 get_task_struct(iter.task);
3230 }
3231 rcu_read_unlock();
3232 return iter;
3233 }
3234
3235 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3236
3237 /* for the /proc/ directory itself, after non-process stuff has been done */
3238 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3239 {
3240 struct tgid_iter iter;
3241 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3242 loff_t pos = ctx->pos;
3243
3244 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3245 return 0;
3246
3247 if (pos == TGID_OFFSET - 2) {
3248 struct inode *inode = d_inode(ns->proc_self);
3249 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3250 return 0;
3251 ctx->pos = pos = pos + 1;
3252 }
3253 if (pos == TGID_OFFSET - 1) {
3254 struct inode *inode = d_inode(ns->proc_thread_self);
3255 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3256 return 0;
3257 ctx->pos = pos = pos + 1;
3258 }
3259 iter.tgid = pos - TGID_OFFSET;
3260 iter.task = NULL;
3261 for (iter = next_tgid(ns, iter);
3262 iter.task;
3263 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3264 char name[10 + 1];
3265 int len;
3266
3267 cond_resched();
3268 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3269 continue;
3270
3271 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3272 ctx->pos = iter.tgid + TGID_OFFSET;
3273 if (!proc_fill_cache(file, ctx, name, len,
3274 proc_pid_instantiate, iter.task, NULL)) {
3275 put_task_struct(iter.task);
3276 return 0;
3277 }
3278 }
3279 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3280 return 0;
3281 }
3282
3283 /*
3284 * proc_tid_comm_permission is a special permission function exclusively
3285 * used for the node /proc/<pid>/task/<tid>/comm.
3286 * It bypasses generic permission checks in the case where a task of the same
3287 * task group attempts to access the node.
3288 * The rationale behind this is that glibc and bionic access this node for
3289 * cross thread naming (pthread_set/getname_np(!self)). However, if
3290 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3291 * which locks out the cross thread naming implementation.
3292 * This function makes sure that the node is always accessible for members of
3293 * same thread group.
3294 */
3295 static int proc_tid_comm_permission(struct inode *inode, int mask)
3296 {
3297 bool is_same_tgroup;
3298 struct task_struct *task;
3299
3300 task = get_proc_task(inode);
3301 if (!task)
3302 return -ESRCH;
3303 is_same_tgroup = same_thread_group(current, task);
3304 put_task_struct(task);
3305
3306 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3307 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3308 * read or written by the members of the corresponding
3309 * thread group.
3310 */
3311 return 0;
3312 }
3313
3314 return generic_permission(inode, mask);
3315 }
3316
3317 static const struct inode_operations proc_tid_comm_inode_operations = {
3318 .permission = proc_tid_comm_permission,
3319 };
3320
3321 /*
3322 * Tasks
3323 */
3324 static const struct pid_entry tid_base_stuff[] = {
3325 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3326 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3327 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3328 #ifdef CONFIG_NET
3329 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3330 #endif
3331 REG("environ", S_IRUSR, proc_environ_operations),
3332 REG("auxv", S_IRUSR, proc_auxv_operations),
3333 ONE("status", S_IRUGO, proc_pid_status),
3334 ONE("personality", S_IRUSR, proc_pid_personality),
3335 ONE("limits", S_IRUGO, proc_pid_limits),
3336 #ifdef CONFIG_SCHED_DEBUG
3337 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3338 #endif
3339 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3340 &proc_tid_comm_inode_operations,
3341 &proc_pid_set_comm_operations, {}),
3342 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3343 ONE("syscall", S_IRUSR, proc_pid_syscall),
3344 #endif
3345 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3346 ONE("stat", S_IRUGO, proc_tid_stat),
3347 ONE("statm", S_IRUGO, proc_pid_statm),
3348 REG("maps", S_IRUGO, proc_tid_maps_operations),
3349 #ifdef CONFIG_PROC_CHILDREN
3350 REG("children", S_IRUGO, proc_tid_children_operations),
3351 #endif
3352 #ifdef CONFIG_NUMA
3353 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3354 #endif
3355 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3356 LNK("cwd", proc_cwd_link),
3357 LNK("root", proc_root_link),
3358 LNK("exe", proc_exe_link),
3359 REG("mounts", S_IRUGO, proc_mounts_operations),
3360 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3361 #ifdef CONFIG_PROC_PAGE_MONITOR
3362 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3363 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3364 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3365 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3366 #endif
3367 #ifdef CONFIG_SECURITY
3368 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3369 #endif
3370 #ifdef CONFIG_KALLSYMS
3371 ONE("wchan", S_IRUGO, proc_pid_wchan),
3372 #endif
3373 #ifdef CONFIG_STACKTRACE
3374 ONE("stack", S_IRUSR, proc_pid_stack),
3375 #endif
3376 #ifdef CONFIG_SCHED_INFO
3377 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3378 #endif
3379 #ifdef CONFIG_LATENCYTOP
3380 REG("latency", S_IRUGO, proc_lstats_operations),
3381 #endif
3382 #ifdef CONFIG_PROC_PID_CPUSET
3383 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3384 #endif
3385 #ifdef CONFIG_CGROUPS
3386 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3387 #endif
3388 ONE("oom_score", S_IRUGO, proc_oom_score),
3389 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3390 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3391 #ifdef CONFIG_AUDITSYSCALL
3392 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3393 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3394 #endif
3395 #ifdef CONFIG_FAULT_INJECTION
3396 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3397 REG("fail-nth", 0644, proc_fail_nth_operations),
3398 #endif
3399 #ifdef CONFIG_TASK_IO_ACCOUNTING
3400 ONE("io", S_IRUSR, proc_tid_io_accounting),
3401 #endif
3402 #ifdef CONFIG_HARDWALL
3403 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3404 #endif
3405 #ifdef CONFIG_USER_NS
3406 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3407 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3408 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3409 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3410 #endif
3411 #ifdef CONFIG_LIVEPATCH
3412 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3413 #endif
3414 };
3415
3416 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3417 {
3418 return proc_pident_readdir(file, ctx,
3419 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3420 }
3421
3422 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3423 {
3424 return proc_pident_lookup(dir, dentry,
3425 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3426 }
3427
3428 static const struct file_operations proc_tid_base_operations = {
3429 .read = generic_read_dir,
3430 .iterate_shared = proc_tid_base_readdir,
3431 .llseek = generic_file_llseek,
3432 };
3433
3434 static const struct inode_operations proc_tid_base_inode_operations = {
3435 .lookup = proc_tid_base_lookup,
3436 .getattr = pid_getattr,
3437 .setattr = proc_setattr,
3438 };
3439
3440 static int proc_task_instantiate(struct inode *dir,
3441 struct dentry *dentry, struct task_struct *task, const void *ptr)
3442 {
3443 struct inode *inode;
3444 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3445
3446 if (!inode)
3447 goto out;
3448 inode->i_op = &proc_tid_base_inode_operations;
3449 inode->i_fop = &proc_tid_base_operations;
3450 inode->i_flags|=S_IMMUTABLE;
3451
3452 set_nlink(inode, nlink_tid);
3453
3454 d_set_d_op(dentry, &pid_dentry_operations);
3455
3456 d_add(dentry, inode);
3457 /* Close the race of the process dying before we return the dentry */
3458 if (pid_revalidate(dentry, 0))
3459 return 0;
3460 out:
3461 return -ENOENT;
3462 }
3463
3464 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3465 {
3466 int result = -ENOENT;
3467 struct task_struct *task;
3468 struct task_struct *leader = get_proc_task(dir);
3469 unsigned tid;
3470 struct pid_namespace *ns;
3471
3472 if (!leader)
3473 goto out_no_task;
3474
3475 tid = name_to_int(&dentry->d_name);
3476 if (tid == ~0U)
3477 goto out;
3478
3479 ns = dentry->d_sb->s_fs_info;
3480 rcu_read_lock();
3481 task = find_task_by_pid_ns(tid, ns);
3482 if (task)
3483 get_task_struct(task);
3484 rcu_read_unlock();
3485 if (!task)
3486 goto out;
3487 if (!same_thread_group(leader, task))
3488 goto out_drop_task;
3489
3490 result = proc_task_instantiate(dir, dentry, task, NULL);
3491 out_drop_task:
3492 put_task_struct(task);
3493 out:
3494 put_task_struct(leader);
3495 out_no_task:
3496 return ERR_PTR(result);
3497 }
3498
3499 /*
3500 * Find the first tid of a thread group to return to user space.
3501 *
3502 * Usually this is just the thread group leader, but if the users
3503 * buffer was too small or there was a seek into the middle of the
3504 * directory we have more work todo.
3505 *
3506 * In the case of a short read we start with find_task_by_pid.
3507 *
3508 * In the case of a seek we start with the leader and walk nr
3509 * threads past it.
3510 */
3511 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3512 struct pid_namespace *ns)
3513 {
3514 struct task_struct *pos, *task;
3515 unsigned long nr = f_pos;
3516
3517 if (nr != f_pos) /* 32bit overflow? */
3518 return NULL;
3519
3520 rcu_read_lock();
3521 task = pid_task(pid, PIDTYPE_PID);
3522 if (!task)
3523 goto fail;
3524
3525 /* Attempt to start with the tid of a thread */
3526 if (tid && nr) {
3527 pos = find_task_by_pid_ns(tid, ns);
3528 if (pos && same_thread_group(pos, task))
3529 goto found;
3530 }
3531
3532 /* If nr exceeds the number of threads there is nothing todo */
3533 if (nr >= get_nr_threads(task))
3534 goto fail;
3535
3536 /* If we haven't found our starting place yet start
3537 * with the leader and walk nr threads forward.
3538 */
3539 pos = task = task->group_leader;
3540 do {
3541 if (!nr--)
3542 goto found;
3543 } while_each_thread(task, pos);
3544 fail:
3545 pos = NULL;
3546 goto out;
3547 found:
3548 get_task_struct(pos);
3549 out:
3550 rcu_read_unlock();
3551 return pos;
3552 }
3553
3554 /*
3555 * Find the next thread in the thread list.
3556 * Return NULL if there is an error or no next thread.
3557 *
3558 * The reference to the input task_struct is released.
3559 */
3560 static struct task_struct *next_tid(struct task_struct *start)
3561 {
3562 struct task_struct *pos = NULL;
3563 rcu_read_lock();
3564 if (pid_alive(start)) {
3565 pos = next_thread(start);
3566 if (thread_group_leader(pos))
3567 pos = NULL;
3568 else
3569 get_task_struct(pos);
3570 }
3571 rcu_read_unlock();
3572 put_task_struct(start);
3573 return pos;
3574 }
3575
3576 /* for the /proc/TGID/task/ directories */
3577 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3578 {
3579 struct inode *inode = file_inode(file);
3580 struct task_struct *task;
3581 struct pid_namespace *ns;
3582 int tid;
3583
3584 if (proc_inode_is_dead(inode))
3585 return -ENOENT;
3586
3587 if (!dir_emit_dots(file, ctx))
3588 return 0;
3589
3590 /* f_version caches the tgid value that the last readdir call couldn't
3591 * return. lseek aka telldir automagically resets f_version to 0.
3592 */
3593 ns = inode->i_sb->s_fs_info;
3594 tid = (int)file->f_version;
3595 file->f_version = 0;
3596 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3597 task;
3598 task = next_tid(task), ctx->pos++) {
3599 char name[10 + 1];
3600 int len;
3601 tid = task_pid_nr_ns(task, ns);
3602 len = snprintf(name, sizeof(name), "%u", tid);
3603 if (!proc_fill_cache(file, ctx, name, len,
3604 proc_task_instantiate, task, NULL)) {
3605 /* returning this tgid failed, save it as the first
3606 * pid for the next readir call */
3607 file->f_version = (u64)tid;
3608 put_task_struct(task);
3609 break;
3610 }
3611 }
3612
3613 return 0;
3614 }
3615
3616 static int proc_task_getattr(const struct path *path, struct kstat *stat,
3617 u32 request_mask, unsigned int query_flags)
3618 {
3619 struct inode *inode = d_inode(path->dentry);
3620 struct task_struct *p = get_proc_task(inode);
3621 generic_fillattr(inode, stat);
3622
3623 if (p) {
3624 stat->nlink += get_nr_threads(p);
3625 put_task_struct(p);
3626 }
3627
3628 return 0;
3629 }
3630
3631 static const struct inode_operations proc_task_inode_operations = {
3632 .lookup = proc_task_lookup,
3633 .getattr = proc_task_getattr,
3634 .setattr = proc_setattr,
3635 .permission = proc_pid_permission,
3636 };
3637
3638 static const struct file_operations proc_task_operations = {
3639 .read = generic_read_dir,
3640 .iterate_shared = proc_task_readdir,
3641 .llseek = generic_file_llseek,
3642 };
3643
3644 void __init set_proc_pid_nlink(void)
3645 {
3646 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3647 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3648 }
3649
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