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Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-zesty-kernel.git] / fs / proc / base.c
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/printk.h>
77 #include <linux/cgroup.h>
78 #include <linux/cpuset.h>
79 #include <linux/audit.h>
80 #include <linux/poll.h>
81 #include <linux/nsproxy.h>
82 #include <linux/oom.h>
83 #include <linux/elf.h>
84 #include <linux/pid_namespace.h>
85 #include <linux/user_namespace.h>
86 #include <linux/fs_struct.h>
87 #include <linux/slab.h>
88 #include <linux/flex_array.h>
89 #include <linux/posix-timers.h>
90 #ifdef CONFIG_HARDWALL
91 #include <asm/hardwall.h>
92 #endif
93 #include <trace/events/oom.h>
94 #include "internal.h"
95 #include "fd.h"
96
97 /* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107 struct pid_entry {
108 const char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114 };
115
116 #define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123 }
124
125 #define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127 #define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131 #define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133 #define ONE(NAME, MODE, show) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
136 { .proc_show = show } )
137
138 /*
139 * Count the number of hardlinks for the pid_entry table, excluding the .
140 * and .. links.
141 */
142 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
143 unsigned int n)
144 {
145 unsigned int i;
146 unsigned int count;
147
148 count = 0;
149 for (i = 0; i < n; ++i) {
150 if (S_ISDIR(entries[i].mode))
151 ++count;
152 }
153
154 return count;
155 }
156
157 static int get_task_root(struct task_struct *task, struct path *root)
158 {
159 int result = -ENOENT;
160
161 task_lock(task);
162 if (task->fs) {
163 get_fs_root(task->fs, root);
164 result = 0;
165 }
166 task_unlock(task);
167 return result;
168 }
169
170 static int proc_cwd_link(struct dentry *dentry, struct path *path)
171 {
172 struct task_struct *task = get_proc_task(d_inode(dentry));
173 int result = -ENOENT;
174
175 if (task) {
176 task_lock(task);
177 if (task->fs) {
178 get_fs_pwd(task->fs, path);
179 result = 0;
180 }
181 task_unlock(task);
182 put_task_struct(task);
183 }
184 return result;
185 }
186
187 static int proc_root_link(struct dentry *dentry, struct path *path)
188 {
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 result = get_task_root(task, path);
194 put_task_struct(task);
195 }
196 return result;
197 }
198
199 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
200 size_t _count, loff_t *pos)
201 {
202 struct task_struct *tsk;
203 struct mm_struct *mm;
204 char *page;
205 unsigned long count = _count;
206 unsigned long arg_start, arg_end, env_start, env_end;
207 unsigned long len1, len2, len;
208 unsigned long p;
209 char c;
210 ssize_t rv;
211
212 BUG_ON(*pos < 0);
213
214 tsk = get_proc_task(file_inode(file));
215 if (!tsk)
216 return -ESRCH;
217 mm = get_task_mm(tsk);
218 put_task_struct(tsk);
219 if (!mm)
220 return 0;
221 /* Check if process spawned far enough to have cmdline. */
222 if (!mm->env_end) {
223 rv = 0;
224 goto out_mmput;
225 }
226
227 page = (char *)__get_free_page(GFP_TEMPORARY);
228 if (!page) {
229 rv = -ENOMEM;
230 goto out_mmput;
231 }
232
233 down_read(&mm->mmap_sem);
234 arg_start = mm->arg_start;
235 arg_end = mm->arg_end;
236 env_start = mm->env_start;
237 env_end = mm->env_end;
238 up_read(&mm->mmap_sem);
239
240 BUG_ON(arg_start > arg_end);
241 BUG_ON(env_start > env_end);
242
243 len1 = arg_end - arg_start;
244 len2 = env_end - env_start;
245
246 /* Empty ARGV. */
247 if (len1 == 0) {
248 rv = 0;
249 goto out_free_page;
250 }
251 /*
252 * Inherently racy -- command line shares address space
253 * with code and data.
254 */
255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
256 if (rv <= 0)
257 goto out_free_page;
258
259 rv = 0;
260
261 if (c == '\0') {
262 /* Command line (set of strings) occupies whole ARGV. */
263 if (len1 <= *pos)
264 goto out_free_page;
265
266 p = arg_start + *pos;
267 len = len1 - *pos;
268 while (count > 0 && len > 0) {
269 unsigned int _count;
270 int nr_read;
271
272 _count = min3(count, len, PAGE_SIZE);
273 nr_read = access_remote_vm(mm, p, page, _count, 0);
274 if (nr_read < 0)
275 rv = nr_read;
276 if (nr_read <= 0)
277 goto out_free_page;
278
279 if (copy_to_user(buf, page, nr_read)) {
280 rv = -EFAULT;
281 goto out_free_page;
282 }
283
284 p += nr_read;
285 len -= nr_read;
286 buf += nr_read;
287 count -= nr_read;
288 rv += nr_read;
289 }
290 } else {
291 /*
292 * Command line (1 string) occupies ARGV and maybe
293 * extends into ENVP.
294 */
295 if (len1 + len2 <= *pos)
296 goto skip_argv_envp;
297 if (len1 <= *pos)
298 goto skip_argv;
299
300 p = arg_start + *pos;
301 len = len1 - *pos;
302 while (count > 0 && len > 0) {
303 unsigned int _count, l;
304 int nr_read;
305 bool final;
306
307 _count = min3(count, len, PAGE_SIZE);
308 nr_read = access_remote_vm(mm, p, page, _count, 0);
309 if (nr_read < 0)
310 rv = nr_read;
311 if (nr_read <= 0)
312 goto out_free_page;
313
314 /*
315 * Command line can be shorter than whole ARGV
316 * even if last "marker" byte says it is not.
317 */
318 final = false;
319 l = strnlen(page, nr_read);
320 if (l < nr_read) {
321 nr_read = l;
322 final = true;
323 }
324
325 if (copy_to_user(buf, page, nr_read)) {
326 rv = -EFAULT;
327 goto out_free_page;
328 }
329
330 p += nr_read;
331 len -= nr_read;
332 buf += nr_read;
333 count -= nr_read;
334 rv += nr_read;
335
336 if (final)
337 goto out_free_page;
338 }
339 skip_argv:
340 /*
341 * Command line (1 string) occupies ARGV and
342 * extends into ENVP.
343 */
344 if (len1 <= *pos) {
345 p = env_start + *pos - len1;
346 len = len1 + len2 - *pos;
347 } else {
348 p = env_start;
349 len = len2;
350 }
351 while (count > 0 && len > 0) {
352 unsigned int _count, l;
353 int nr_read;
354 bool final;
355
356 _count = min3(count, len, PAGE_SIZE);
357 nr_read = access_remote_vm(mm, p, page, _count, 0);
358 if (nr_read < 0)
359 rv = nr_read;
360 if (nr_read <= 0)
361 goto out_free_page;
362
363 /* Find EOS. */
364 final = false;
365 l = strnlen(page, nr_read);
366 if (l < nr_read) {
367 nr_read = l;
368 final = true;
369 }
370
371 if (copy_to_user(buf, page, nr_read)) {
372 rv = -EFAULT;
373 goto out_free_page;
374 }
375
376 p += nr_read;
377 len -= nr_read;
378 buf += nr_read;
379 count -= nr_read;
380 rv += nr_read;
381
382 if (final)
383 goto out_free_page;
384 }
385 skip_argv_envp:
386 ;
387 }
388
389 out_free_page:
390 free_page((unsigned long)page);
391 out_mmput:
392 mmput(mm);
393 if (rv > 0)
394 *pos += rv;
395 return rv;
396 }
397
398 static const struct file_operations proc_pid_cmdline_ops = {
399 .read = proc_pid_cmdline_read,
400 .llseek = generic_file_llseek,
401 };
402
403 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
404 struct pid *pid, struct task_struct *task)
405 {
406 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
407 if (mm && !IS_ERR(mm)) {
408 unsigned int nwords = 0;
409 do {
410 nwords += 2;
411 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
412 seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0]));
413 mmput(mm);
414 return 0;
415 } else
416 return PTR_ERR(mm);
417 }
418
419
420 #ifdef CONFIG_KALLSYMS
421 /*
422 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
423 * Returns the resolved symbol. If that fails, simply return the address.
424 */
425 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427 {
428 unsigned long wchan;
429 char symname[KSYM_NAME_LEN];
430
431 wchan = get_wchan(task);
432
433 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
434 && !lookup_symbol_name(wchan, symname))
435 seq_printf(m, "%s", symname);
436 else
437 seq_putc(m, '0');
438
439 return 0;
440 }
441 #endif /* CONFIG_KALLSYMS */
442
443 static int lock_trace(struct task_struct *task)
444 {
445 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
446 if (err)
447 return err;
448 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
449 mutex_unlock(&task->signal->cred_guard_mutex);
450 return -EPERM;
451 }
452 return 0;
453 }
454
455 static void unlock_trace(struct task_struct *task)
456 {
457 mutex_unlock(&task->signal->cred_guard_mutex);
458 }
459
460 #ifdef CONFIG_STACKTRACE
461
462 #define MAX_STACK_TRACE_DEPTH 64
463
464 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
465 struct pid *pid, struct task_struct *task)
466 {
467 struct stack_trace trace;
468 unsigned long *entries;
469 int err;
470 int i;
471
472 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
473 if (!entries)
474 return -ENOMEM;
475
476 trace.nr_entries = 0;
477 trace.max_entries = MAX_STACK_TRACE_DEPTH;
478 trace.entries = entries;
479 trace.skip = 0;
480
481 err = lock_trace(task);
482 if (!err) {
483 save_stack_trace_tsk(task, &trace);
484
485 for (i = 0; i < trace.nr_entries; i++) {
486 seq_printf(m, "[<%pK>] %pB\n",
487 (void *)entries[i], (void *)entries[i]);
488 }
489 unlock_trace(task);
490 }
491 kfree(entries);
492
493 return err;
494 }
495 #endif
496
497 #ifdef CONFIG_SCHED_INFO
498 /*
499 * Provides /proc/PID/schedstat
500 */
501 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
502 struct pid *pid, struct task_struct *task)
503 {
504 if (unlikely(!sched_info_on()))
505 seq_printf(m, "0 0 0\n");
506 else
507 seq_printf(m, "%llu %llu %lu\n",
508 (unsigned long long)task->se.sum_exec_runtime,
509 (unsigned long long)task->sched_info.run_delay,
510 task->sched_info.pcount);
511
512 return 0;
513 }
514 #endif
515
516 #ifdef CONFIG_LATENCYTOP
517 static int lstats_show_proc(struct seq_file *m, void *v)
518 {
519 int i;
520 struct inode *inode = m->private;
521 struct task_struct *task = get_proc_task(inode);
522
523 if (!task)
524 return -ESRCH;
525 seq_puts(m, "Latency Top version : v0.1\n");
526 for (i = 0; i < 32; i++) {
527 struct latency_record *lr = &task->latency_record[i];
528 if (lr->backtrace[0]) {
529 int q;
530 seq_printf(m, "%i %li %li",
531 lr->count, lr->time, lr->max);
532 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
533 unsigned long bt = lr->backtrace[q];
534 if (!bt)
535 break;
536 if (bt == ULONG_MAX)
537 break;
538 seq_printf(m, " %ps", (void *)bt);
539 }
540 seq_putc(m, '\n');
541 }
542
543 }
544 put_task_struct(task);
545 return 0;
546 }
547
548 static int lstats_open(struct inode *inode, struct file *file)
549 {
550 return single_open(file, lstats_show_proc, inode);
551 }
552
553 static ssize_t lstats_write(struct file *file, const char __user *buf,
554 size_t count, loff_t *offs)
555 {
556 struct task_struct *task = get_proc_task(file_inode(file));
557
558 if (!task)
559 return -ESRCH;
560 clear_all_latency_tracing(task);
561 put_task_struct(task);
562
563 return count;
564 }
565
566 static const struct file_operations proc_lstats_operations = {
567 .open = lstats_open,
568 .read = seq_read,
569 .write = lstats_write,
570 .llseek = seq_lseek,
571 .release = single_release,
572 };
573
574 #endif
575
576 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
577 struct pid *pid, struct task_struct *task)
578 {
579 unsigned long totalpages = totalram_pages + total_swap_pages;
580 unsigned long points = 0;
581
582 points = oom_badness(task, NULL, NULL, totalpages) *
583 1000 / totalpages;
584 seq_printf(m, "%lu\n", points);
585
586 return 0;
587 }
588
589 struct limit_names {
590 const char *name;
591 const char *unit;
592 };
593
594 static const struct limit_names lnames[RLIM_NLIMITS] = {
595 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
596 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
597 [RLIMIT_DATA] = {"Max data size", "bytes"},
598 [RLIMIT_STACK] = {"Max stack size", "bytes"},
599 [RLIMIT_CORE] = {"Max core file size", "bytes"},
600 [RLIMIT_RSS] = {"Max resident set", "bytes"},
601 [RLIMIT_NPROC] = {"Max processes", "processes"},
602 [RLIMIT_NOFILE] = {"Max open files", "files"},
603 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
604 [RLIMIT_AS] = {"Max address space", "bytes"},
605 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
606 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
607 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
608 [RLIMIT_NICE] = {"Max nice priority", NULL},
609 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
610 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
611 };
612
613 /* Display limits for a process */
614 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
615 struct pid *pid, struct task_struct *task)
616 {
617 unsigned int i;
618 unsigned long flags;
619
620 struct rlimit rlim[RLIM_NLIMITS];
621
622 if (!lock_task_sighand(task, &flags))
623 return 0;
624 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
625 unlock_task_sighand(task, &flags);
626
627 /*
628 * print the file header
629 */
630 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
631 "Limit", "Soft Limit", "Hard Limit", "Units");
632
633 for (i = 0; i < RLIM_NLIMITS; i++) {
634 if (rlim[i].rlim_cur == RLIM_INFINITY)
635 seq_printf(m, "%-25s %-20s ",
636 lnames[i].name, "unlimited");
637 else
638 seq_printf(m, "%-25s %-20lu ",
639 lnames[i].name, rlim[i].rlim_cur);
640
641 if (rlim[i].rlim_max == RLIM_INFINITY)
642 seq_printf(m, "%-20s ", "unlimited");
643 else
644 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
645
646 if (lnames[i].unit)
647 seq_printf(m, "%-10s\n", lnames[i].unit);
648 else
649 seq_putc(m, '\n');
650 }
651
652 return 0;
653 }
654
655 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
656 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
657 struct pid *pid, struct task_struct *task)
658 {
659 long nr;
660 unsigned long args[6], sp, pc;
661 int res;
662
663 res = lock_trace(task);
664 if (res)
665 return res;
666
667 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
668 seq_puts(m, "running\n");
669 else if (nr < 0)
670 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
671 else
672 seq_printf(m,
673 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
674 nr,
675 args[0], args[1], args[2], args[3], args[4], args[5],
676 sp, pc);
677 unlock_trace(task);
678
679 return 0;
680 }
681 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
682
683 /************************************************************************/
684 /* Here the fs part begins */
685 /************************************************************************/
686
687 /* permission checks */
688 static int proc_fd_access_allowed(struct inode *inode)
689 {
690 struct task_struct *task;
691 int allowed = 0;
692 /* Allow access to a task's file descriptors if it is us or we
693 * may use ptrace attach to the process and find out that
694 * information.
695 */
696 task = get_proc_task(inode);
697 if (task) {
698 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
699 put_task_struct(task);
700 }
701 return allowed;
702 }
703
704 int proc_setattr(struct dentry *dentry, struct iattr *attr)
705 {
706 int error;
707 struct inode *inode = d_inode(dentry);
708
709 if (attr->ia_valid & ATTR_MODE)
710 return -EPERM;
711
712 error = inode_change_ok(inode, attr);
713 if (error)
714 return error;
715
716 setattr_copy(inode, attr);
717 mark_inode_dirty(inode);
718 return 0;
719 }
720
721 /*
722 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
723 * or euid/egid (for hide_pid_min=2)?
724 */
725 static bool has_pid_permissions(struct pid_namespace *pid,
726 struct task_struct *task,
727 int hide_pid_min)
728 {
729 if (pid->hide_pid < hide_pid_min)
730 return true;
731 if (in_group_p(pid->pid_gid))
732 return true;
733 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
734 }
735
736
737 static int proc_pid_permission(struct inode *inode, int mask)
738 {
739 struct pid_namespace *pid = inode->i_sb->s_fs_info;
740 struct task_struct *task;
741 bool has_perms;
742
743 task = get_proc_task(inode);
744 if (!task)
745 return -ESRCH;
746 has_perms = has_pid_permissions(pid, task, 1);
747 put_task_struct(task);
748
749 if (!has_perms) {
750 if (pid->hide_pid == 2) {
751 /*
752 * Let's make getdents(), stat(), and open()
753 * consistent with each other. If a process
754 * may not stat() a file, it shouldn't be seen
755 * in procfs at all.
756 */
757 return -ENOENT;
758 }
759
760 return -EPERM;
761 }
762 return generic_permission(inode, mask);
763 }
764
765
766
767 static const struct inode_operations proc_def_inode_operations = {
768 .setattr = proc_setattr,
769 };
770
771 static int proc_single_show(struct seq_file *m, void *v)
772 {
773 struct inode *inode = m->private;
774 struct pid_namespace *ns;
775 struct pid *pid;
776 struct task_struct *task;
777 int ret;
778
779 ns = inode->i_sb->s_fs_info;
780 pid = proc_pid(inode);
781 task = get_pid_task(pid, PIDTYPE_PID);
782 if (!task)
783 return -ESRCH;
784
785 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
786
787 put_task_struct(task);
788 return ret;
789 }
790
791 static int proc_single_open(struct inode *inode, struct file *filp)
792 {
793 return single_open(filp, proc_single_show, inode);
794 }
795
796 static const struct file_operations proc_single_file_operations = {
797 .open = proc_single_open,
798 .read = seq_read,
799 .llseek = seq_lseek,
800 .release = single_release,
801 };
802
803
804 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
805 {
806 struct task_struct *task = get_proc_task(inode);
807 struct mm_struct *mm = ERR_PTR(-ESRCH);
808
809 if (task) {
810 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
811 put_task_struct(task);
812
813 if (!IS_ERR_OR_NULL(mm)) {
814 /* ensure this mm_struct can't be freed */
815 atomic_inc(&mm->mm_count);
816 /* but do not pin its memory */
817 mmput(mm);
818 }
819 }
820
821 return mm;
822 }
823
824 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
825 {
826 struct mm_struct *mm = proc_mem_open(inode, mode);
827
828 if (IS_ERR(mm))
829 return PTR_ERR(mm);
830
831 file->private_data = mm;
832 return 0;
833 }
834
835 static int mem_open(struct inode *inode, struct file *file)
836 {
837 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
838
839 /* OK to pass negative loff_t, we can catch out-of-range */
840 file->f_mode |= FMODE_UNSIGNED_OFFSET;
841
842 return ret;
843 }
844
845 static ssize_t mem_rw(struct file *file, char __user *buf,
846 size_t count, loff_t *ppos, int write)
847 {
848 struct mm_struct *mm = file->private_data;
849 unsigned long addr = *ppos;
850 ssize_t copied;
851 char *page;
852
853 if (!mm)
854 return 0;
855
856 page = (char *)__get_free_page(GFP_TEMPORARY);
857 if (!page)
858 return -ENOMEM;
859
860 copied = 0;
861 if (!atomic_inc_not_zero(&mm->mm_users))
862 goto free;
863
864 while (count > 0) {
865 int this_len = min_t(int, count, PAGE_SIZE);
866
867 if (write && copy_from_user(page, buf, this_len)) {
868 copied = -EFAULT;
869 break;
870 }
871
872 this_len = access_remote_vm(mm, addr, page, this_len, write);
873 if (!this_len) {
874 if (!copied)
875 copied = -EIO;
876 break;
877 }
878
879 if (!write && copy_to_user(buf, page, this_len)) {
880 copied = -EFAULT;
881 break;
882 }
883
884 buf += this_len;
885 addr += this_len;
886 copied += this_len;
887 count -= this_len;
888 }
889 *ppos = addr;
890
891 mmput(mm);
892 free:
893 free_page((unsigned long) page);
894 return copied;
895 }
896
897 static ssize_t mem_read(struct file *file, char __user *buf,
898 size_t count, loff_t *ppos)
899 {
900 return mem_rw(file, buf, count, ppos, 0);
901 }
902
903 static ssize_t mem_write(struct file *file, const char __user *buf,
904 size_t count, loff_t *ppos)
905 {
906 return mem_rw(file, (char __user*)buf, count, ppos, 1);
907 }
908
909 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
910 {
911 switch (orig) {
912 case 0:
913 file->f_pos = offset;
914 break;
915 case 1:
916 file->f_pos += offset;
917 break;
918 default:
919 return -EINVAL;
920 }
921 force_successful_syscall_return();
922 return file->f_pos;
923 }
924
925 static int mem_release(struct inode *inode, struct file *file)
926 {
927 struct mm_struct *mm = file->private_data;
928 if (mm)
929 mmdrop(mm);
930 return 0;
931 }
932
933 static const struct file_operations proc_mem_operations = {
934 .llseek = mem_lseek,
935 .read = mem_read,
936 .write = mem_write,
937 .open = mem_open,
938 .release = mem_release,
939 };
940
941 static int environ_open(struct inode *inode, struct file *file)
942 {
943 return __mem_open(inode, file, PTRACE_MODE_READ);
944 }
945
946 static ssize_t environ_read(struct file *file, char __user *buf,
947 size_t count, loff_t *ppos)
948 {
949 char *page;
950 unsigned long src = *ppos;
951 int ret = 0;
952 struct mm_struct *mm = file->private_data;
953 unsigned long env_start, env_end;
954
955 /* Ensure the process spawned far enough to have an environment. */
956 if (!mm || !mm->env_end)
957 return 0;
958
959 page = (char *)__get_free_page(GFP_TEMPORARY);
960 if (!page)
961 return -ENOMEM;
962
963 ret = 0;
964 if (!atomic_inc_not_zero(&mm->mm_users))
965 goto free;
966
967 down_read(&mm->mmap_sem);
968 env_start = mm->env_start;
969 env_end = mm->env_end;
970 up_read(&mm->mmap_sem);
971
972 while (count > 0) {
973 size_t this_len, max_len;
974 int retval;
975
976 if (src >= (env_end - env_start))
977 break;
978
979 this_len = env_end - (env_start + src);
980
981 max_len = min_t(size_t, PAGE_SIZE, count);
982 this_len = min(max_len, this_len);
983
984 retval = access_remote_vm(mm, (env_start + src),
985 page, this_len, 0);
986
987 if (retval <= 0) {
988 ret = retval;
989 break;
990 }
991
992 if (copy_to_user(buf, page, retval)) {
993 ret = -EFAULT;
994 break;
995 }
996
997 ret += retval;
998 src += retval;
999 buf += retval;
1000 count -= retval;
1001 }
1002 *ppos = src;
1003 mmput(mm);
1004
1005 free:
1006 free_page((unsigned long) page);
1007 return ret;
1008 }
1009
1010 static const struct file_operations proc_environ_operations = {
1011 .open = environ_open,
1012 .read = environ_read,
1013 .llseek = generic_file_llseek,
1014 .release = mem_release,
1015 };
1016
1017 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1018 loff_t *ppos)
1019 {
1020 struct task_struct *task = get_proc_task(file_inode(file));
1021 char buffer[PROC_NUMBUF];
1022 int oom_adj = OOM_ADJUST_MIN;
1023 size_t len;
1024
1025 if (!task)
1026 return -ESRCH;
1027 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1028 oom_adj = OOM_ADJUST_MAX;
1029 else
1030 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1031 OOM_SCORE_ADJ_MAX;
1032 put_task_struct(task);
1033 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1034 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1035 }
1036
1037 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1038 {
1039 static DEFINE_MUTEX(oom_adj_mutex);
1040 struct mm_struct *mm = NULL;
1041 struct task_struct *task;
1042 int err = 0;
1043
1044 task = get_proc_task(file_inode(file));
1045 if (!task)
1046 return -ESRCH;
1047
1048 mutex_lock(&oom_adj_mutex);
1049 if (legacy) {
1050 if (oom_adj < task->signal->oom_score_adj &&
1051 !capable(CAP_SYS_RESOURCE)) {
1052 err = -EACCES;
1053 goto err_unlock;
1054 }
1055 /*
1056 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1057 * /proc/pid/oom_score_adj instead.
1058 */
1059 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1060 current->comm, task_pid_nr(current), task_pid_nr(task),
1061 task_pid_nr(task));
1062 } else {
1063 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1064 !capable(CAP_SYS_RESOURCE)) {
1065 err = -EACCES;
1066 goto err_unlock;
1067 }
1068 }
1069
1070 /*
1071 * Make sure we will check other processes sharing the mm if this is
1072 * not vfrok which wants its own oom_score_adj.
1073 * pin the mm so it doesn't go away and get reused after task_unlock
1074 */
1075 if (!task->vfork_done) {
1076 struct task_struct *p = find_lock_task_mm(task);
1077
1078 if (p) {
1079 if (atomic_read(&p->mm->mm_users) > 1) {
1080 mm = p->mm;
1081 atomic_inc(&mm->mm_count);
1082 }
1083 task_unlock(p);
1084 }
1085 }
1086
1087 task->signal->oom_score_adj = oom_adj;
1088 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1089 task->signal->oom_score_adj_min = (short)oom_adj;
1090 trace_oom_score_adj_update(task);
1091
1092 if (mm) {
1093 struct task_struct *p;
1094
1095 rcu_read_lock();
1096 for_each_process(p) {
1097 if (same_thread_group(task, p))
1098 continue;
1099
1100 /* do not touch kernel threads or the global init */
1101 if (p->flags & PF_KTHREAD || is_global_init(p))
1102 continue;
1103
1104 task_lock(p);
1105 if (!p->vfork_done && process_shares_mm(p, mm)) {
1106 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",
1107 task_pid_nr(p), p->comm,
1108 p->signal->oom_score_adj, oom_adj,
1109 task_pid_nr(task), task->comm);
1110 p->signal->oom_score_adj = oom_adj;
1111 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1112 p->signal->oom_score_adj_min = (short)oom_adj;
1113 }
1114 task_unlock(p);
1115 }
1116 rcu_read_unlock();
1117 mmdrop(mm);
1118 }
1119 err_unlock:
1120 mutex_unlock(&oom_adj_mutex);
1121 put_task_struct(task);
1122 return err;
1123 }
1124
1125 /*
1126 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1127 * kernels. The effective policy is defined by oom_score_adj, which has a
1128 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1129 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1130 * Processes that become oom disabled via oom_adj will still be oom disabled
1131 * with this implementation.
1132 *
1133 * oom_adj cannot be removed since existing userspace binaries use it.
1134 */
1135 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1136 size_t count, loff_t *ppos)
1137 {
1138 char buffer[PROC_NUMBUF];
1139 int oom_adj;
1140 int err;
1141
1142 memset(buffer, 0, sizeof(buffer));
1143 if (count > sizeof(buffer) - 1)
1144 count = sizeof(buffer) - 1;
1145 if (copy_from_user(buffer, buf, count)) {
1146 err = -EFAULT;
1147 goto out;
1148 }
1149
1150 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1151 if (err)
1152 goto out;
1153 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1154 oom_adj != OOM_DISABLE) {
1155 err = -EINVAL;
1156 goto out;
1157 }
1158
1159 /*
1160 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1161 * value is always attainable.
1162 */
1163 if (oom_adj == OOM_ADJUST_MAX)
1164 oom_adj = OOM_SCORE_ADJ_MAX;
1165 else
1166 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1167
1168 err = __set_oom_adj(file, oom_adj, true);
1169 out:
1170 return err < 0 ? err : count;
1171 }
1172
1173 static const struct file_operations proc_oom_adj_operations = {
1174 .read = oom_adj_read,
1175 .write = oom_adj_write,
1176 .llseek = generic_file_llseek,
1177 };
1178
1179 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1180 size_t count, loff_t *ppos)
1181 {
1182 struct task_struct *task = get_proc_task(file_inode(file));
1183 char buffer[PROC_NUMBUF];
1184 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1185 size_t len;
1186
1187 if (!task)
1188 return -ESRCH;
1189 oom_score_adj = task->signal->oom_score_adj;
1190 put_task_struct(task);
1191 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1192 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1193 }
1194
1195 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1196 size_t count, loff_t *ppos)
1197 {
1198 char buffer[PROC_NUMBUF];
1199 int oom_score_adj;
1200 int err;
1201
1202 memset(buffer, 0, sizeof(buffer));
1203 if (count > sizeof(buffer) - 1)
1204 count = sizeof(buffer) - 1;
1205 if (copy_from_user(buffer, buf, count)) {
1206 err = -EFAULT;
1207 goto out;
1208 }
1209
1210 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1211 if (err)
1212 goto out;
1213 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1214 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1215 err = -EINVAL;
1216 goto out;
1217 }
1218
1219 err = __set_oom_adj(file, oom_score_adj, false);
1220 out:
1221 return err < 0 ? err : count;
1222 }
1223
1224 static const struct file_operations proc_oom_score_adj_operations = {
1225 .read = oom_score_adj_read,
1226 .write = oom_score_adj_write,
1227 .llseek = default_llseek,
1228 };
1229
1230 #ifdef CONFIG_AUDITSYSCALL
1231 #define TMPBUFLEN 21
1232 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1233 size_t count, loff_t *ppos)
1234 {
1235 struct inode * inode = file_inode(file);
1236 struct task_struct *task = get_proc_task(inode);
1237 ssize_t length;
1238 char tmpbuf[TMPBUFLEN];
1239
1240 if (!task)
1241 return -ESRCH;
1242 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1243 from_kuid(file->f_cred->user_ns,
1244 audit_get_loginuid(task)));
1245 put_task_struct(task);
1246 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1247 }
1248
1249 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1250 size_t count, loff_t *ppos)
1251 {
1252 struct inode * inode = file_inode(file);
1253 uid_t loginuid;
1254 kuid_t kloginuid;
1255 int rv;
1256
1257 rcu_read_lock();
1258 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1259 rcu_read_unlock();
1260 return -EPERM;
1261 }
1262 rcu_read_unlock();
1263
1264 if (*ppos != 0) {
1265 /* No partial writes. */
1266 return -EINVAL;
1267 }
1268
1269 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1270 if (rv < 0)
1271 return rv;
1272
1273 /* is userspace tring to explicitly UNSET the loginuid? */
1274 if (loginuid == AUDIT_UID_UNSET) {
1275 kloginuid = INVALID_UID;
1276 } else {
1277 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1278 if (!uid_valid(kloginuid))
1279 return -EINVAL;
1280 }
1281
1282 rv = audit_set_loginuid(kloginuid);
1283 if (rv < 0)
1284 return rv;
1285 return count;
1286 }
1287
1288 static const struct file_operations proc_loginuid_operations = {
1289 .read = proc_loginuid_read,
1290 .write = proc_loginuid_write,
1291 .llseek = generic_file_llseek,
1292 };
1293
1294 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1295 size_t count, loff_t *ppos)
1296 {
1297 struct inode * inode = file_inode(file);
1298 struct task_struct *task = get_proc_task(inode);
1299 ssize_t length;
1300 char tmpbuf[TMPBUFLEN];
1301
1302 if (!task)
1303 return -ESRCH;
1304 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1305 audit_get_sessionid(task));
1306 put_task_struct(task);
1307 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1308 }
1309
1310 static const struct file_operations proc_sessionid_operations = {
1311 .read = proc_sessionid_read,
1312 .llseek = generic_file_llseek,
1313 };
1314 #endif
1315
1316 #ifdef CONFIG_FAULT_INJECTION
1317 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1318 size_t count, loff_t *ppos)
1319 {
1320 struct task_struct *task = get_proc_task(file_inode(file));
1321 char buffer[PROC_NUMBUF];
1322 size_t len;
1323 int make_it_fail;
1324
1325 if (!task)
1326 return -ESRCH;
1327 make_it_fail = task->make_it_fail;
1328 put_task_struct(task);
1329
1330 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1331
1332 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1333 }
1334
1335 static ssize_t proc_fault_inject_write(struct file * file,
1336 const char __user * buf, size_t count, loff_t *ppos)
1337 {
1338 struct task_struct *task;
1339 char buffer[PROC_NUMBUF];
1340 int make_it_fail;
1341 int rv;
1342
1343 if (!capable(CAP_SYS_RESOURCE))
1344 return -EPERM;
1345 memset(buffer, 0, sizeof(buffer));
1346 if (count > sizeof(buffer) - 1)
1347 count = sizeof(buffer) - 1;
1348 if (copy_from_user(buffer, buf, count))
1349 return -EFAULT;
1350 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1351 if (rv < 0)
1352 return rv;
1353 if (make_it_fail < 0 || make_it_fail > 1)
1354 return -EINVAL;
1355
1356 task = get_proc_task(file_inode(file));
1357 if (!task)
1358 return -ESRCH;
1359 task->make_it_fail = make_it_fail;
1360 put_task_struct(task);
1361
1362 return count;
1363 }
1364
1365 static const struct file_operations proc_fault_inject_operations = {
1366 .read = proc_fault_inject_read,
1367 .write = proc_fault_inject_write,
1368 .llseek = generic_file_llseek,
1369 };
1370 #endif
1371
1372
1373 #ifdef CONFIG_SCHED_DEBUG
1374 /*
1375 * Print out various scheduling related per-task fields:
1376 */
1377 static int sched_show(struct seq_file *m, void *v)
1378 {
1379 struct inode *inode = m->private;
1380 struct task_struct *p;
1381
1382 p = get_proc_task(inode);
1383 if (!p)
1384 return -ESRCH;
1385 proc_sched_show_task(p, m);
1386
1387 put_task_struct(p);
1388
1389 return 0;
1390 }
1391
1392 static ssize_t
1393 sched_write(struct file *file, const char __user *buf,
1394 size_t count, loff_t *offset)
1395 {
1396 struct inode *inode = file_inode(file);
1397 struct task_struct *p;
1398
1399 p = get_proc_task(inode);
1400 if (!p)
1401 return -ESRCH;
1402 proc_sched_set_task(p);
1403
1404 put_task_struct(p);
1405
1406 return count;
1407 }
1408
1409 static int sched_open(struct inode *inode, struct file *filp)
1410 {
1411 return single_open(filp, sched_show, inode);
1412 }
1413
1414 static const struct file_operations proc_pid_sched_operations = {
1415 .open = sched_open,
1416 .read = seq_read,
1417 .write = sched_write,
1418 .llseek = seq_lseek,
1419 .release = single_release,
1420 };
1421
1422 #endif
1423
1424 #ifdef CONFIG_SCHED_AUTOGROUP
1425 /*
1426 * Print out autogroup related information:
1427 */
1428 static int sched_autogroup_show(struct seq_file *m, void *v)
1429 {
1430 struct inode *inode = m->private;
1431 struct task_struct *p;
1432
1433 p = get_proc_task(inode);
1434 if (!p)
1435 return -ESRCH;
1436 proc_sched_autogroup_show_task(p, m);
1437
1438 put_task_struct(p);
1439
1440 return 0;
1441 }
1442
1443 static ssize_t
1444 sched_autogroup_write(struct file *file, const char __user *buf,
1445 size_t count, loff_t *offset)
1446 {
1447 struct inode *inode = file_inode(file);
1448 struct task_struct *p;
1449 char buffer[PROC_NUMBUF];
1450 int nice;
1451 int err;
1452
1453 memset(buffer, 0, sizeof(buffer));
1454 if (count > sizeof(buffer) - 1)
1455 count = sizeof(buffer) - 1;
1456 if (copy_from_user(buffer, buf, count))
1457 return -EFAULT;
1458
1459 err = kstrtoint(strstrip(buffer), 0, &nice);
1460 if (err < 0)
1461 return err;
1462
1463 p = get_proc_task(inode);
1464 if (!p)
1465 return -ESRCH;
1466
1467 err = proc_sched_autogroup_set_nice(p, nice);
1468 if (err)
1469 count = err;
1470
1471 put_task_struct(p);
1472
1473 return count;
1474 }
1475
1476 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1477 {
1478 int ret;
1479
1480 ret = single_open(filp, sched_autogroup_show, NULL);
1481 if (!ret) {
1482 struct seq_file *m = filp->private_data;
1483
1484 m->private = inode;
1485 }
1486 return ret;
1487 }
1488
1489 static const struct file_operations proc_pid_sched_autogroup_operations = {
1490 .open = sched_autogroup_open,
1491 .read = seq_read,
1492 .write = sched_autogroup_write,
1493 .llseek = seq_lseek,
1494 .release = single_release,
1495 };
1496
1497 #endif /* CONFIG_SCHED_AUTOGROUP */
1498
1499 static ssize_t comm_write(struct file *file, const char __user *buf,
1500 size_t count, loff_t *offset)
1501 {
1502 struct inode *inode = file_inode(file);
1503 struct task_struct *p;
1504 char buffer[TASK_COMM_LEN];
1505 const size_t maxlen = sizeof(buffer) - 1;
1506
1507 memset(buffer, 0, sizeof(buffer));
1508 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1509 return -EFAULT;
1510
1511 p = get_proc_task(inode);
1512 if (!p)
1513 return -ESRCH;
1514
1515 if (same_thread_group(current, p))
1516 set_task_comm(p, buffer);
1517 else
1518 count = -EINVAL;
1519
1520 put_task_struct(p);
1521
1522 return count;
1523 }
1524
1525 static int comm_show(struct seq_file *m, void *v)
1526 {
1527 struct inode *inode = m->private;
1528 struct task_struct *p;
1529
1530 p = get_proc_task(inode);
1531 if (!p)
1532 return -ESRCH;
1533
1534 task_lock(p);
1535 seq_printf(m, "%s\n", p->comm);
1536 task_unlock(p);
1537
1538 put_task_struct(p);
1539
1540 return 0;
1541 }
1542
1543 static int comm_open(struct inode *inode, struct file *filp)
1544 {
1545 return single_open(filp, comm_show, inode);
1546 }
1547
1548 static const struct file_operations proc_pid_set_comm_operations = {
1549 .open = comm_open,
1550 .read = seq_read,
1551 .write = comm_write,
1552 .llseek = seq_lseek,
1553 .release = single_release,
1554 };
1555
1556 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1557 {
1558 struct task_struct *task;
1559 struct file *exe_file;
1560
1561 task = get_proc_task(d_inode(dentry));
1562 if (!task)
1563 return -ENOENT;
1564 exe_file = get_task_exe_file(task);
1565 put_task_struct(task);
1566 if (exe_file) {
1567 *exe_path = exe_file->f_path;
1568 path_get(&exe_file->f_path);
1569 fput(exe_file);
1570 return 0;
1571 } else
1572 return -ENOENT;
1573 }
1574
1575 static const char *proc_pid_get_link(struct dentry *dentry,
1576 struct inode *inode,
1577 struct delayed_call *done)
1578 {
1579 struct path path;
1580 int error = -EACCES;
1581
1582 if (!dentry)
1583 return ERR_PTR(-ECHILD);
1584
1585 /* Are we allowed to snoop on the tasks file descriptors? */
1586 if (!proc_fd_access_allowed(inode))
1587 goto out;
1588
1589 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1590 if (error)
1591 goto out;
1592
1593 nd_jump_link(&path);
1594 return NULL;
1595 out:
1596 return ERR_PTR(error);
1597 }
1598
1599 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1600 {
1601 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1602 char *pathname;
1603 int len;
1604
1605 if (!tmp)
1606 return -ENOMEM;
1607
1608 pathname = d_path(path, tmp, PAGE_SIZE);
1609 len = PTR_ERR(pathname);
1610 if (IS_ERR(pathname))
1611 goto out;
1612 len = tmp + PAGE_SIZE - 1 - pathname;
1613
1614 if (len > buflen)
1615 len = buflen;
1616 if (copy_to_user(buffer, pathname, len))
1617 len = -EFAULT;
1618 out:
1619 free_page((unsigned long)tmp);
1620 return len;
1621 }
1622
1623 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1624 {
1625 int error = -EACCES;
1626 struct inode *inode = d_inode(dentry);
1627 struct path path;
1628
1629 /* Are we allowed to snoop on the tasks file descriptors? */
1630 if (!proc_fd_access_allowed(inode))
1631 goto out;
1632
1633 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1634 if (error)
1635 goto out;
1636
1637 error = do_proc_readlink(&path, buffer, buflen);
1638 path_put(&path);
1639 out:
1640 return error;
1641 }
1642
1643 const struct inode_operations proc_pid_link_inode_operations = {
1644 .readlink = proc_pid_readlink,
1645 .get_link = proc_pid_get_link,
1646 .setattr = proc_setattr,
1647 };
1648
1649
1650 /* building an inode */
1651
1652 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1653 {
1654 struct inode * inode;
1655 struct proc_inode *ei;
1656 const struct cred *cred;
1657
1658 /* We need a new inode */
1659
1660 inode = new_inode(sb);
1661 if (!inode)
1662 goto out;
1663
1664 /* Common stuff */
1665 ei = PROC_I(inode);
1666 inode->i_ino = get_next_ino();
1667 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1668 inode->i_op = &proc_def_inode_operations;
1669
1670 /*
1671 * grab the reference to task.
1672 */
1673 ei->pid = get_task_pid(task, PIDTYPE_PID);
1674 if (!ei->pid)
1675 goto out_unlock;
1676
1677 if (task_dumpable(task)) {
1678 rcu_read_lock();
1679 cred = __task_cred(task);
1680 inode->i_uid = cred->euid;
1681 inode->i_gid = cred->egid;
1682 rcu_read_unlock();
1683 }
1684 security_task_to_inode(task, inode);
1685
1686 out:
1687 return inode;
1688
1689 out_unlock:
1690 iput(inode);
1691 return NULL;
1692 }
1693
1694 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1695 {
1696 struct inode *inode = d_inode(dentry);
1697 struct task_struct *task;
1698 const struct cred *cred;
1699 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1700
1701 generic_fillattr(inode, stat);
1702
1703 rcu_read_lock();
1704 stat->uid = GLOBAL_ROOT_UID;
1705 stat->gid = GLOBAL_ROOT_GID;
1706 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1707 if (task) {
1708 if (!has_pid_permissions(pid, task, 2)) {
1709 rcu_read_unlock();
1710 /*
1711 * This doesn't prevent learning whether PID exists,
1712 * it only makes getattr() consistent with readdir().
1713 */
1714 return -ENOENT;
1715 }
1716 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1717 task_dumpable(task)) {
1718 cred = __task_cred(task);
1719 stat->uid = cred->euid;
1720 stat->gid = cred->egid;
1721 }
1722 }
1723 rcu_read_unlock();
1724 return 0;
1725 }
1726
1727 /* dentry stuff */
1728
1729 /*
1730 * Exceptional case: normally we are not allowed to unhash a busy
1731 * directory. In this case, however, we can do it - no aliasing problems
1732 * due to the way we treat inodes.
1733 *
1734 * Rewrite the inode's ownerships here because the owning task may have
1735 * performed a setuid(), etc.
1736 *
1737 * Before the /proc/pid/status file was created the only way to read
1738 * the effective uid of a /process was to stat /proc/pid. Reading
1739 * /proc/pid/status is slow enough that procps and other packages
1740 * kept stating /proc/pid. To keep the rules in /proc simple I have
1741 * made this apply to all per process world readable and executable
1742 * directories.
1743 */
1744 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1745 {
1746 struct inode *inode;
1747 struct task_struct *task;
1748 const struct cred *cred;
1749
1750 if (flags & LOOKUP_RCU)
1751 return -ECHILD;
1752
1753 inode = d_inode(dentry);
1754 task = get_proc_task(inode);
1755
1756 if (task) {
1757 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1758 task_dumpable(task)) {
1759 rcu_read_lock();
1760 cred = __task_cred(task);
1761 inode->i_uid = cred->euid;
1762 inode->i_gid = cred->egid;
1763 rcu_read_unlock();
1764 } else {
1765 inode->i_uid = GLOBAL_ROOT_UID;
1766 inode->i_gid = GLOBAL_ROOT_GID;
1767 }
1768 inode->i_mode &= ~(S_ISUID | S_ISGID);
1769 security_task_to_inode(task, inode);
1770 put_task_struct(task);
1771 return 1;
1772 }
1773 return 0;
1774 }
1775
1776 static inline bool proc_inode_is_dead(struct inode *inode)
1777 {
1778 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1779 }
1780
1781 int pid_delete_dentry(const struct dentry *dentry)
1782 {
1783 /* Is the task we represent dead?
1784 * If so, then don't put the dentry on the lru list,
1785 * kill it immediately.
1786 */
1787 return proc_inode_is_dead(d_inode(dentry));
1788 }
1789
1790 const struct dentry_operations pid_dentry_operations =
1791 {
1792 .d_revalidate = pid_revalidate,
1793 .d_delete = pid_delete_dentry,
1794 };
1795
1796 /* Lookups */
1797
1798 /*
1799 * Fill a directory entry.
1800 *
1801 * If possible create the dcache entry and derive our inode number and
1802 * file type from dcache entry.
1803 *
1804 * Since all of the proc inode numbers are dynamically generated, the inode
1805 * numbers do not exist until the inode is cache. This means creating the
1806 * the dcache entry in readdir is necessary to keep the inode numbers
1807 * reported by readdir in sync with the inode numbers reported
1808 * by stat.
1809 */
1810 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1811 const char *name, int len,
1812 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1813 {
1814 struct dentry *child, *dir = file->f_path.dentry;
1815 struct qstr qname = QSTR_INIT(name, len);
1816 struct inode *inode;
1817 unsigned type;
1818 ino_t ino;
1819
1820 child = d_hash_and_lookup(dir, &qname);
1821 if (!child) {
1822 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1823 child = d_alloc_parallel(dir, &qname, &wq);
1824 if (IS_ERR(child))
1825 goto end_instantiate;
1826 if (d_in_lookup(child)) {
1827 int err = instantiate(d_inode(dir), child, task, ptr);
1828 d_lookup_done(child);
1829 if (err < 0) {
1830 dput(child);
1831 goto end_instantiate;
1832 }
1833 }
1834 }
1835 inode = d_inode(child);
1836 ino = inode->i_ino;
1837 type = inode->i_mode >> 12;
1838 dput(child);
1839 return dir_emit(ctx, name, len, ino, type);
1840
1841 end_instantiate:
1842 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1843 }
1844
1845 /*
1846 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1847 * which represent vma start and end addresses.
1848 */
1849 static int dname_to_vma_addr(struct dentry *dentry,
1850 unsigned long *start, unsigned long *end)
1851 {
1852 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1853 return -EINVAL;
1854
1855 return 0;
1856 }
1857
1858 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1859 {
1860 unsigned long vm_start, vm_end;
1861 bool exact_vma_exists = false;
1862 struct mm_struct *mm = NULL;
1863 struct task_struct *task;
1864 const struct cred *cred;
1865 struct inode *inode;
1866 int status = 0;
1867
1868 if (flags & LOOKUP_RCU)
1869 return -ECHILD;
1870
1871 inode = d_inode(dentry);
1872 task = get_proc_task(inode);
1873 if (!task)
1874 goto out_notask;
1875
1876 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1877 if (IS_ERR_OR_NULL(mm))
1878 goto out;
1879
1880 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1881 down_read(&mm->mmap_sem);
1882 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1883 up_read(&mm->mmap_sem);
1884 }
1885
1886 mmput(mm);
1887
1888 if (exact_vma_exists) {
1889 if (task_dumpable(task)) {
1890 rcu_read_lock();
1891 cred = __task_cred(task);
1892 inode->i_uid = cred->euid;
1893 inode->i_gid = cred->egid;
1894 rcu_read_unlock();
1895 } else {
1896 inode->i_uid = GLOBAL_ROOT_UID;
1897 inode->i_gid = GLOBAL_ROOT_GID;
1898 }
1899 security_task_to_inode(task, inode);
1900 status = 1;
1901 }
1902
1903 out:
1904 put_task_struct(task);
1905
1906 out_notask:
1907 return status;
1908 }
1909
1910 static const struct dentry_operations tid_map_files_dentry_operations = {
1911 .d_revalidate = map_files_d_revalidate,
1912 .d_delete = pid_delete_dentry,
1913 };
1914
1915 static int map_files_get_link(struct dentry *dentry, struct path *path)
1916 {
1917 unsigned long vm_start, vm_end;
1918 struct vm_area_struct *vma;
1919 struct task_struct *task;
1920 struct mm_struct *mm;
1921 int rc;
1922
1923 rc = -ENOENT;
1924 task = get_proc_task(d_inode(dentry));
1925 if (!task)
1926 goto out;
1927
1928 mm = get_task_mm(task);
1929 put_task_struct(task);
1930 if (!mm)
1931 goto out;
1932
1933 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1934 if (rc)
1935 goto out_mmput;
1936
1937 rc = -ENOENT;
1938 down_read(&mm->mmap_sem);
1939 vma = find_exact_vma(mm, vm_start, vm_end);
1940 if (vma && vma->vm_file) {
1941 *path = vma->vm_file->f_path;
1942 path_get(path);
1943 rc = 0;
1944 }
1945 up_read(&mm->mmap_sem);
1946
1947 out_mmput:
1948 mmput(mm);
1949 out:
1950 return rc;
1951 }
1952
1953 struct map_files_info {
1954 fmode_t mode;
1955 unsigned long len;
1956 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1957 };
1958
1959 /*
1960 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1961 * symlinks may be used to bypass permissions on ancestor directories in the
1962 * path to the file in question.
1963 */
1964 static const char *
1965 proc_map_files_get_link(struct dentry *dentry,
1966 struct inode *inode,
1967 struct delayed_call *done)
1968 {
1969 if (!capable(CAP_SYS_ADMIN))
1970 return ERR_PTR(-EPERM);
1971
1972 return proc_pid_get_link(dentry, inode, done);
1973 }
1974
1975 /*
1976 * Identical to proc_pid_link_inode_operations except for get_link()
1977 */
1978 static const struct inode_operations proc_map_files_link_inode_operations = {
1979 .readlink = proc_pid_readlink,
1980 .get_link = proc_map_files_get_link,
1981 .setattr = proc_setattr,
1982 };
1983
1984 static int
1985 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1986 struct task_struct *task, const void *ptr)
1987 {
1988 fmode_t mode = (fmode_t)(unsigned long)ptr;
1989 struct proc_inode *ei;
1990 struct inode *inode;
1991
1992 inode = proc_pid_make_inode(dir->i_sb, task);
1993 if (!inode)
1994 return -ENOENT;
1995
1996 ei = PROC_I(inode);
1997 ei->op.proc_get_link = map_files_get_link;
1998
1999 inode->i_op = &proc_map_files_link_inode_operations;
2000 inode->i_size = 64;
2001 inode->i_mode = S_IFLNK;
2002
2003 if (mode & FMODE_READ)
2004 inode->i_mode |= S_IRUSR;
2005 if (mode & FMODE_WRITE)
2006 inode->i_mode |= S_IWUSR;
2007
2008 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2009 d_add(dentry, inode);
2010
2011 return 0;
2012 }
2013
2014 static struct dentry *proc_map_files_lookup(struct inode *dir,
2015 struct dentry *dentry, unsigned int flags)
2016 {
2017 unsigned long vm_start, vm_end;
2018 struct vm_area_struct *vma;
2019 struct task_struct *task;
2020 int result;
2021 struct mm_struct *mm;
2022
2023 result = -ENOENT;
2024 task = get_proc_task(dir);
2025 if (!task)
2026 goto out;
2027
2028 result = -EACCES;
2029 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2030 goto out_put_task;
2031
2032 result = -ENOENT;
2033 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2034 goto out_put_task;
2035
2036 mm = get_task_mm(task);
2037 if (!mm)
2038 goto out_put_task;
2039
2040 down_read(&mm->mmap_sem);
2041 vma = find_exact_vma(mm, vm_start, vm_end);
2042 if (!vma)
2043 goto out_no_vma;
2044
2045 if (vma->vm_file)
2046 result = proc_map_files_instantiate(dir, dentry, task,
2047 (void *)(unsigned long)vma->vm_file->f_mode);
2048
2049 out_no_vma:
2050 up_read(&mm->mmap_sem);
2051 mmput(mm);
2052 out_put_task:
2053 put_task_struct(task);
2054 out:
2055 return ERR_PTR(result);
2056 }
2057
2058 static const struct inode_operations proc_map_files_inode_operations = {
2059 .lookup = proc_map_files_lookup,
2060 .permission = proc_fd_permission,
2061 .setattr = proc_setattr,
2062 };
2063
2064 static int
2065 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2066 {
2067 struct vm_area_struct *vma;
2068 struct task_struct *task;
2069 struct mm_struct *mm;
2070 unsigned long nr_files, pos, i;
2071 struct flex_array *fa = NULL;
2072 struct map_files_info info;
2073 struct map_files_info *p;
2074 int ret;
2075
2076 ret = -ENOENT;
2077 task = get_proc_task(file_inode(file));
2078 if (!task)
2079 goto out;
2080
2081 ret = -EACCES;
2082 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2083 goto out_put_task;
2084
2085 ret = 0;
2086 if (!dir_emit_dots(file, ctx))
2087 goto out_put_task;
2088
2089 mm = get_task_mm(task);
2090 if (!mm)
2091 goto out_put_task;
2092 down_read(&mm->mmap_sem);
2093
2094 nr_files = 0;
2095
2096 /*
2097 * We need two passes here:
2098 *
2099 * 1) Collect vmas of mapped files with mmap_sem taken
2100 * 2) Release mmap_sem and instantiate entries
2101 *
2102 * otherwise we get lockdep complained, since filldir()
2103 * routine might require mmap_sem taken in might_fault().
2104 */
2105
2106 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2107 if (vma->vm_file && ++pos > ctx->pos)
2108 nr_files++;
2109 }
2110
2111 if (nr_files) {
2112 fa = flex_array_alloc(sizeof(info), nr_files,
2113 GFP_KERNEL);
2114 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2115 GFP_KERNEL)) {
2116 ret = -ENOMEM;
2117 if (fa)
2118 flex_array_free(fa);
2119 up_read(&mm->mmap_sem);
2120 mmput(mm);
2121 goto out_put_task;
2122 }
2123 for (i = 0, vma = mm->mmap, pos = 2; vma;
2124 vma = vma->vm_next) {
2125 if (!vma->vm_file)
2126 continue;
2127 if (++pos <= ctx->pos)
2128 continue;
2129
2130 info.mode = vma->vm_file->f_mode;
2131 info.len = snprintf(info.name,
2132 sizeof(info.name), "%lx-%lx",
2133 vma->vm_start, vma->vm_end);
2134 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2135 BUG();
2136 }
2137 }
2138 up_read(&mm->mmap_sem);
2139
2140 for (i = 0; i < nr_files; i++) {
2141 p = flex_array_get(fa, i);
2142 if (!proc_fill_cache(file, ctx,
2143 p->name, p->len,
2144 proc_map_files_instantiate,
2145 task,
2146 (void *)(unsigned long)p->mode))
2147 break;
2148 ctx->pos++;
2149 }
2150 if (fa)
2151 flex_array_free(fa);
2152 mmput(mm);
2153
2154 out_put_task:
2155 put_task_struct(task);
2156 out:
2157 return ret;
2158 }
2159
2160 static const struct file_operations proc_map_files_operations = {
2161 .read = generic_read_dir,
2162 .iterate_shared = proc_map_files_readdir,
2163 .llseek = generic_file_llseek,
2164 };
2165
2166 #ifdef CONFIG_CHECKPOINT_RESTORE
2167 struct timers_private {
2168 struct pid *pid;
2169 struct task_struct *task;
2170 struct sighand_struct *sighand;
2171 struct pid_namespace *ns;
2172 unsigned long flags;
2173 };
2174
2175 static void *timers_start(struct seq_file *m, loff_t *pos)
2176 {
2177 struct timers_private *tp = m->private;
2178
2179 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2180 if (!tp->task)
2181 return ERR_PTR(-ESRCH);
2182
2183 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2184 if (!tp->sighand)
2185 return ERR_PTR(-ESRCH);
2186
2187 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2188 }
2189
2190 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2191 {
2192 struct timers_private *tp = m->private;
2193 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2194 }
2195
2196 static void timers_stop(struct seq_file *m, void *v)
2197 {
2198 struct timers_private *tp = m->private;
2199
2200 if (tp->sighand) {
2201 unlock_task_sighand(tp->task, &tp->flags);
2202 tp->sighand = NULL;
2203 }
2204
2205 if (tp->task) {
2206 put_task_struct(tp->task);
2207 tp->task = NULL;
2208 }
2209 }
2210
2211 static int show_timer(struct seq_file *m, void *v)
2212 {
2213 struct k_itimer *timer;
2214 struct timers_private *tp = m->private;
2215 int notify;
2216 static const char * const nstr[] = {
2217 [SIGEV_SIGNAL] = "signal",
2218 [SIGEV_NONE] = "none",
2219 [SIGEV_THREAD] = "thread",
2220 };
2221
2222 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2223 notify = timer->it_sigev_notify;
2224
2225 seq_printf(m, "ID: %d\n", timer->it_id);
2226 seq_printf(m, "signal: %d/%p\n",
2227 timer->sigq->info.si_signo,
2228 timer->sigq->info.si_value.sival_ptr);
2229 seq_printf(m, "notify: %s/%s.%d\n",
2230 nstr[notify & ~SIGEV_THREAD_ID],
2231 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2232 pid_nr_ns(timer->it_pid, tp->ns));
2233 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2234
2235 return 0;
2236 }
2237
2238 static const struct seq_operations proc_timers_seq_ops = {
2239 .start = timers_start,
2240 .next = timers_next,
2241 .stop = timers_stop,
2242 .show = show_timer,
2243 };
2244
2245 static int proc_timers_open(struct inode *inode, struct file *file)
2246 {
2247 struct timers_private *tp;
2248
2249 tp = __seq_open_private(file, &proc_timers_seq_ops,
2250 sizeof(struct timers_private));
2251 if (!tp)
2252 return -ENOMEM;
2253
2254 tp->pid = proc_pid(inode);
2255 tp->ns = inode->i_sb->s_fs_info;
2256 return 0;
2257 }
2258
2259 static const struct file_operations proc_timers_operations = {
2260 .open = proc_timers_open,
2261 .read = seq_read,
2262 .llseek = seq_lseek,
2263 .release = seq_release_private,
2264 };
2265 #endif
2266
2267 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2268 size_t count, loff_t *offset)
2269 {
2270 struct inode *inode = file_inode(file);
2271 struct task_struct *p;
2272 u64 slack_ns;
2273 int err;
2274
2275 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2276 if (err < 0)
2277 return err;
2278
2279 p = get_proc_task(inode);
2280 if (!p)
2281 return -ESRCH;
2282
2283 if (p != current) {
2284 if (!capable(CAP_SYS_NICE)) {
2285 count = -EPERM;
2286 goto out;
2287 }
2288
2289 err = security_task_setscheduler(p);
2290 if (err) {
2291 count = err;
2292 goto out;
2293 }
2294 }
2295
2296 task_lock(p);
2297 if (slack_ns == 0)
2298 p->timer_slack_ns = p->default_timer_slack_ns;
2299 else
2300 p->timer_slack_ns = slack_ns;
2301 task_unlock(p);
2302
2303 out:
2304 put_task_struct(p);
2305
2306 return count;
2307 }
2308
2309 static int timerslack_ns_show(struct seq_file *m, void *v)
2310 {
2311 struct inode *inode = m->private;
2312 struct task_struct *p;
2313 int err = 0;
2314
2315 p = get_proc_task(inode);
2316 if (!p)
2317 return -ESRCH;
2318
2319 if (p != current) {
2320
2321 if (!capable(CAP_SYS_NICE)) {
2322 err = -EPERM;
2323 goto out;
2324 }
2325 err = security_task_getscheduler(p);
2326 if (err)
2327 goto out;
2328 }
2329
2330 task_lock(p);
2331 seq_printf(m, "%llu\n", p->timer_slack_ns);
2332 task_unlock(p);
2333
2334 out:
2335 put_task_struct(p);
2336
2337 return err;
2338 }
2339
2340 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2341 {
2342 return single_open(filp, timerslack_ns_show, inode);
2343 }
2344
2345 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2346 .open = timerslack_ns_open,
2347 .read = seq_read,
2348 .write = timerslack_ns_write,
2349 .llseek = seq_lseek,
2350 .release = single_release,
2351 };
2352
2353 static int proc_pident_instantiate(struct inode *dir,
2354 struct dentry *dentry, struct task_struct *task, const void *ptr)
2355 {
2356 const struct pid_entry *p = ptr;
2357 struct inode *inode;
2358 struct proc_inode *ei;
2359
2360 inode = proc_pid_make_inode(dir->i_sb, task);
2361 if (!inode)
2362 goto out;
2363
2364 ei = PROC_I(inode);
2365 inode->i_mode = p->mode;
2366 if (S_ISDIR(inode->i_mode))
2367 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2368 if (p->iop)
2369 inode->i_op = p->iop;
2370 if (p->fop)
2371 inode->i_fop = p->fop;
2372 ei->op = p->op;
2373 d_set_d_op(dentry, &pid_dentry_operations);
2374 d_add(dentry, inode);
2375 /* Close the race of the process dying before we return the dentry */
2376 if (pid_revalidate(dentry, 0))
2377 return 0;
2378 out:
2379 return -ENOENT;
2380 }
2381
2382 static struct dentry *proc_pident_lookup(struct inode *dir,
2383 struct dentry *dentry,
2384 const struct pid_entry *ents,
2385 unsigned int nents)
2386 {
2387 int error;
2388 struct task_struct *task = get_proc_task(dir);
2389 const struct pid_entry *p, *last;
2390
2391 error = -ENOENT;
2392
2393 if (!task)
2394 goto out_no_task;
2395
2396 /*
2397 * Yes, it does not scale. And it should not. Don't add
2398 * new entries into /proc/<tgid>/ without very good reasons.
2399 */
2400 last = &ents[nents - 1];
2401 for (p = ents; p <= last; p++) {
2402 if (p->len != dentry->d_name.len)
2403 continue;
2404 if (!memcmp(dentry->d_name.name, p->name, p->len))
2405 break;
2406 }
2407 if (p > last)
2408 goto out;
2409
2410 error = proc_pident_instantiate(dir, dentry, task, p);
2411 out:
2412 put_task_struct(task);
2413 out_no_task:
2414 return ERR_PTR(error);
2415 }
2416
2417 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2418 const struct pid_entry *ents, unsigned int nents)
2419 {
2420 struct task_struct *task = get_proc_task(file_inode(file));
2421 const struct pid_entry *p;
2422
2423 if (!task)
2424 return -ENOENT;
2425
2426 if (!dir_emit_dots(file, ctx))
2427 goto out;
2428
2429 if (ctx->pos >= nents + 2)
2430 goto out;
2431
2432 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2433 if (!proc_fill_cache(file, ctx, p->name, p->len,
2434 proc_pident_instantiate, task, p))
2435 break;
2436 ctx->pos++;
2437 }
2438 out:
2439 put_task_struct(task);
2440 return 0;
2441 }
2442
2443 #ifdef CONFIG_SECURITY
2444 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2445 size_t count, loff_t *ppos)
2446 {
2447 struct inode * inode = file_inode(file);
2448 char *p = NULL;
2449 ssize_t length;
2450 struct task_struct *task = get_proc_task(inode);
2451
2452 if (!task)
2453 return -ESRCH;
2454
2455 length = security_getprocattr(task,
2456 (char*)file->f_path.dentry->d_name.name,
2457 &p);
2458 put_task_struct(task);
2459 if (length > 0)
2460 length = simple_read_from_buffer(buf, count, ppos, p, length);
2461 kfree(p);
2462 return length;
2463 }
2464
2465 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2466 size_t count, loff_t *ppos)
2467 {
2468 struct inode * inode = file_inode(file);
2469 void *page;
2470 ssize_t length;
2471 struct task_struct *task = get_proc_task(inode);
2472
2473 length = -ESRCH;
2474 if (!task)
2475 goto out_no_task;
2476 if (count > PAGE_SIZE)
2477 count = PAGE_SIZE;
2478
2479 /* No partial writes. */
2480 length = -EINVAL;
2481 if (*ppos != 0)
2482 goto out;
2483
2484 page = memdup_user(buf, count);
2485 if (IS_ERR(page)) {
2486 length = PTR_ERR(page);
2487 goto out;
2488 }
2489
2490 /* Guard against adverse ptrace interaction */
2491 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2492 if (length < 0)
2493 goto out_free;
2494
2495 length = security_setprocattr(task,
2496 (char*)file->f_path.dentry->d_name.name,
2497 page, count);
2498 mutex_unlock(&task->signal->cred_guard_mutex);
2499 out_free:
2500 kfree(page);
2501 out:
2502 put_task_struct(task);
2503 out_no_task:
2504 return length;
2505 }
2506
2507 static const struct file_operations proc_pid_attr_operations = {
2508 .read = proc_pid_attr_read,
2509 .write = proc_pid_attr_write,
2510 .llseek = generic_file_llseek,
2511 };
2512
2513 static const struct pid_entry attr_dir_stuff[] = {
2514 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2515 REG("prev", S_IRUGO, proc_pid_attr_operations),
2516 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2517 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2518 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2519 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2520 };
2521
2522 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2523 {
2524 return proc_pident_readdir(file, ctx,
2525 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2526 }
2527
2528 static const struct file_operations proc_attr_dir_operations = {
2529 .read = generic_read_dir,
2530 .iterate_shared = proc_attr_dir_readdir,
2531 .llseek = generic_file_llseek,
2532 };
2533
2534 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2535 struct dentry *dentry, unsigned int flags)
2536 {
2537 return proc_pident_lookup(dir, dentry,
2538 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2539 }
2540
2541 static const struct inode_operations proc_attr_dir_inode_operations = {
2542 .lookup = proc_attr_dir_lookup,
2543 .getattr = pid_getattr,
2544 .setattr = proc_setattr,
2545 };
2546
2547 #endif
2548
2549 #ifdef CONFIG_ELF_CORE
2550 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2551 size_t count, loff_t *ppos)
2552 {
2553 struct task_struct *task = get_proc_task(file_inode(file));
2554 struct mm_struct *mm;
2555 char buffer[PROC_NUMBUF];
2556 size_t len;
2557 int ret;
2558
2559 if (!task)
2560 return -ESRCH;
2561
2562 ret = 0;
2563 mm = get_task_mm(task);
2564 if (mm) {
2565 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2566 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2567 MMF_DUMP_FILTER_SHIFT));
2568 mmput(mm);
2569 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2570 }
2571
2572 put_task_struct(task);
2573
2574 return ret;
2575 }
2576
2577 static ssize_t proc_coredump_filter_write(struct file *file,
2578 const char __user *buf,
2579 size_t count,
2580 loff_t *ppos)
2581 {
2582 struct task_struct *task;
2583 struct mm_struct *mm;
2584 unsigned int val;
2585 int ret;
2586 int i;
2587 unsigned long mask;
2588
2589 ret = kstrtouint_from_user(buf, count, 0, &val);
2590 if (ret < 0)
2591 return ret;
2592
2593 ret = -ESRCH;
2594 task = get_proc_task(file_inode(file));
2595 if (!task)
2596 goto out_no_task;
2597
2598 mm = get_task_mm(task);
2599 if (!mm)
2600 goto out_no_mm;
2601 ret = 0;
2602
2603 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2604 if (val & mask)
2605 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2606 else
2607 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2608 }
2609
2610 mmput(mm);
2611 out_no_mm:
2612 put_task_struct(task);
2613 out_no_task:
2614 if (ret < 0)
2615 return ret;
2616 return count;
2617 }
2618
2619 static const struct file_operations proc_coredump_filter_operations = {
2620 .read = proc_coredump_filter_read,
2621 .write = proc_coredump_filter_write,
2622 .llseek = generic_file_llseek,
2623 };
2624 #endif
2625
2626 #ifdef CONFIG_TASK_IO_ACCOUNTING
2627 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2628 {
2629 struct task_io_accounting acct = task->ioac;
2630 unsigned long flags;
2631 int result;
2632
2633 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2634 if (result)
2635 return result;
2636
2637 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2638 result = -EACCES;
2639 goto out_unlock;
2640 }
2641
2642 if (whole && lock_task_sighand(task, &flags)) {
2643 struct task_struct *t = task;
2644
2645 task_io_accounting_add(&acct, &task->signal->ioac);
2646 while_each_thread(task, t)
2647 task_io_accounting_add(&acct, &t->ioac);
2648
2649 unlock_task_sighand(task, &flags);
2650 }
2651 seq_printf(m,
2652 "rchar: %llu\n"
2653 "wchar: %llu\n"
2654 "syscr: %llu\n"
2655 "syscw: %llu\n"
2656 "read_bytes: %llu\n"
2657 "write_bytes: %llu\n"
2658 "cancelled_write_bytes: %llu\n",
2659 (unsigned long long)acct.rchar,
2660 (unsigned long long)acct.wchar,
2661 (unsigned long long)acct.syscr,
2662 (unsigned long long)acct.syscw,
2663 (unsigned long long)acct.read_bytes,
2664 (unsigned long long)acct.write_bytes,
2665 (unsigned long long)acct.cancelled_write_bytes);
2666 result = 0;
2667
2668 out_unlock:
2669 mutex_unlock(&task->signal->cred_guard_mutex);
2670 return result;
2671 }
2672
2673 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2674 struct pid *pid, struct task_struct *task)
2675 {
2676 return do_io_accounting(task, m, 0);
2677 }
2678
2679 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2680 struct pid *pid, struct task_struct *task)
2681 {
2682 return do_io_accounting(task, m, 1);
2683 }
2684 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2685
2686 #ifdef CONFIG_USER_NS
2687 static int proc_id_map_open(struct inode *inode, struct file *file,
2688 const struct seq_operations *seq_ops)
2689 {
2690 struct user_namespace *ns = NULL;
2691 struct task_struct *task;
2692 struct seq_file *seq;
2693 int ret = -EINVAL;
2694
2695 task = get_proc_task(inode);
2696 if (task) {
2697 rcu_read_lock();
2698 ns = get_user_ns(task_cred_xxx(task, user_ns));
2699 rcu_read_unlock();
2700 put_task_struct(task);
2701 }
2702 if (!ns)
2703 goto err;
2704
2705 ret = seq_open(file, seq_ops);
2706 if (ret)
2707 goto err_put_ns;
2708
2709 seq = file->private_data;
2710 seq->private = ns;
2711
2712 return 0;
2713 err_put_ns:
2714 put_user_ns(ns);
2715 err:
2716 return ret;
2717 }
2718
2719 static int proc_id_map_release(struct inode *inode, struct file *file)
2720 {
2721 struct seq_file *seq = file->private_data;
2722 struct user_namespace *ns = seq->private;
2723 put_user_ns(ns);
2724 return seq_release(inode, file);
2725 }
2726
2727 static int proc_uid_map_open(struct inode *inode, struct file *file)
2728 {
2729 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2730 }
2731
2732 static int proc_gid_map_open(struct inode *inode, struct file *file)
2733 {
2734 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2735 }
2736
2737 static int proc_projid_map_open(struct inode *inode, struct file *file)
2738 {
2739 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2740 }
2741
2742 static const struct file_operations proc_uid_map_operations = {
2743 .open = proc_uid_map_open,
2744 .write = proc_uid_map_write,
2745 .read = seq_read,
2746 .llseek = seq_lseek,
2747 .release = proc_id_map_release,
2748 };
2749
2750 static const struct file_operations proc_gid_map_operations = {
2751 .open = proc_gid_map_open,
2752 .write = proc_gid_map_write,
2753 .read = seq_read,
2754 .llseek = seq_lseek,
2755 .release = proc_id_map_release,
2756 };
2757
2758 static const struct file_operations proc_projid_map_operations = {
2759 .open = proc_projid_map_open,
2760 .write = proc_projid_map_write,
2761 .read = seq_read,
2762 .llseek = seq_lseek,
2763 .release = proc_id_map_release,
2764 };
2765
2766 static int proc_setgroups_open(struct inode *inode, struct file *file)
2767 {
2768 struct user_namespace *ns = NULL;
2769 struct task_struct *task;
2770 int ret;
2771
2772 ret = -ESRCH;
2773 task = get_proc_task(inode);
2774 if (task) {
2775 rcu_read_lock();
2776 ns = get_user_ns(task_cred_xxx(task, user_ns));
2777 rcu_read_unlock();
2778 put_task_struct(task);
2779 }
2780 if (!ns)
2781 goto err;
2782
2783 if (file->f_mode & FMODE_WRITE) {
2784 ret = -EACCES;
2785 if (!ns_capable(ns, CAP_SYS_ADMIN))
2786 goto err_put_ns;
2787 }
2788
2789 ret = single_open(file, &proc_setgroups_show, ns);
2790 if (ret)
2791 goto err_put_ns;
2792
2793 return 0;
2794 err_put_ns:
2795 put_user_ns(ns);
2796 err:
2797 return ret;
2798 }
2799
2800 static int proc_setgroups_release(struct inode *inode, struct file *file)
2801 {
2802 struct seq_file *seq = file->private_data;
2803 struct user_namespace *ns = seq->private;
2804 int ret = single_release(inode, file);
2805 put_user_ns(ns);
2806 return ret;
2807 }
2808
2809 static const struct file_operations proc_setgroups_operations = {
2810 .open = proc_setgroups_open,
2811 .write = proc_setgroups_write,
2812 .read = seq_read,
2813 .llseek = seq_lseek,
2814 .release = proc_setgroups_release,
2815 };
2816 #endif /* CONFIG_USER_NS */
2817
2818 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2819 struct pid *pid, struct task_struct *task)
2820 {
2821 int err = lock_trace(task);
2822 if (!err) {
2823 seq_printf(m, "%08x\n", task->personality);
2824 unlock_trace(task);
2825 }
2826 return err;
2827 }
2828
2829 /*
2830 * Thread groups
2831 */
2832 static const struct file_operations proc_task_operations;
2833 static const struct inode_operations proc_task_inode_operations;
2834
2835 static const struct pid_entry tgid_base_stuff[] = {
2836 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2837 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2838 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2839 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2840 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2841 #ifdef CONFIG_NET
2842 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2843 #endif
2844 REG("environ", S_IRUSR, proc_environ_operations),
2845 ONE("auxv", S_IRUSR, proc_pid_auxv),
2846 ONE("status", S_IRUGO, proc_pid_status),
2847 ONE("personality", S_IRUSR, proc_pid_personality),
2848 ONE("limits", S_IRUGO, proc_pid_limits),
2849 #ifdef CONFIG_SCHED_DEBUG
2850 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2851 #endif
2852 #ifdef CONFIG_SCHED_AUTOGROUP
2853 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2854 #endif
2855 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2856 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2857 ONE("syscall", S_IRUSR, proc_pid_syscall),
2858 #endif
2859 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2860 ONE("stat", S_IRUGO, proc_tgid_stat),
2861 ONE("statm", S_IRUGO, proc_pid_statm),
2862 REG("maps", S_IRUGO, proc_pid_maps_operations),
2863 #ifdef CONFIG_NUMA
2864 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2865 #endif
2866 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2867 LNK("cwd", proc_cwd_link),
2868 LNK("root", proc_root_link),
2869 LNK("exe", proc_exe_link),
2870 REG("mounts", S_IRUGO, proc_mounts_operations),
2871 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2872 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2873 #ifdef CONFIG_PROC_PAGE_MONITOR
2874 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2875 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2876 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2877 #endif
2878 #ifdef CONFIG_SECURITY
2879 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2880 #endif
2881 #ifdef CONFIG_KALLSYMS
2882 ONE("wchan", S_IRUGO, proc_pid_wchan),
2883 #endif
2884 #ifdef CONFIG_STACKTRACE
2885 ONE("stack", S_IRUSR, proc_pid_stack),
2886 #endif
2887 #ifdef CONFIG_SCHED_INFO
2888 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2889 #endif
2890 #ifdef CONFIG_LATENCYTOP
2891 REG("latency", S_IRUGO, proc_lstats_operations),
2892 #endif
2893 #ifdef CONFIG_PROC_PID_CPUSET
2894 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2895 #endif
2896 #ifdef CONFIG_CGROUPS
2897 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2898 #endif
2899 ONE("oom_score", S_IRUGO, proc_oom_score),
2900 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2901 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2902 #ifdef CONFIG_AUDITSYSCALL
2903 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2904 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2905 #endif
2906 #ifdef CONFIG_FAULT_INJECTION
2907 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2908 #endif
2909 #ifdef CONFIG_ELF_CORE
2910 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2911 #endif
2912 #ifdef CONFIG_TASK_IO_ACCOUNTING
2913 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2914 #endif
2915 #ifdef CONFIG_HARDWALL
2916 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2917 #endif
2918 #ifdef CONFIG_USER_NS
2919 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2920 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2921 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2922 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2923 #endif
2924 #ifdef CONFIG_CHECKPOINT_RESTORE
2925 REG("timers", S_IRUGO, proc_timers_operations),
2926 #endif
2927 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2928 };
2929
2930 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2931 {
2932 return proc_pident_readdir(file, ctx,
2933 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2934 }
2935
2936 static const struct file_operations proc_tgid_base_operations = {
2937 .read = generic_read_dir,
2938 .iterate_shared = proc_tgid_base_readdir,
2939 .llseek = generic_file_llseek,
2940 };
2941
2942 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2943 {
2944 return proc_pident_lookup(dir, dentry,
2945 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2946 }
2947
2948 static const struct inode_operations proc_tgid_base_inode_operations = {
2949 .lookup = proc_tgid_base_lookup,
2950 .getattr = pid_getattr,
2951 .setattr = proc_setattr,
2952 .permission = proc_pid_permission,
2953 };
2954
2955 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2956 {
2957 struct dentry *dentry, *leader, *dir;
2958 char buf[PROC_NUMBUF];
2959 struct qstr name;
2960
2961 name.name = buf;
2962 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2963 /* no ->d_hash() rejects on procfs */
2964 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2965 if (dentry) {
2966 d_invalidate(dentry);
2967 dput(dentry);
2968 }
2969
2970 if (pid == tgid)
2971 return;
2972
2973 name.name = buf;
2974 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2975 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2976 if (!leader)
2977 goto out;
2978
2979 name.name = "task";
2980 name.len = strlen(name.name);
2981 dir = d_hash_and_lookup(leader, &name);
2982 if (!dir)
2983 goto out_put_leader;
2984
2985 name.name = buf;
2986 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2987 dentry = d_hash_and_lookup(dir, &name);
2988 if (dentry) {
2989 d_invalidate(dentry);
2990 dput(dentry);
2991 }
2992
2993 dput(dir);
2994 out_put_leader:
2995 dput(leader);
2996 out:
2997 return;
2998 }
2999
3000 /**
3001 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3002 * @task: task that should be flushed.
3003 *
3004 * When flushing dentries from proc, one needs to flush them from global
3005 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3006 * in. This call is supposed to do all of this job.
3007 *
3008 * Looks in the dcache for
3009 * /proc/@pid
3010 * /proc/@tgid/task/@pid
3011 * if either directory is present flushes it and all of it'ts children
3012 * from the dcache.
3013 *
3014 * It is safe and reasonable to cache /proc entries for a task until
3015 * that task exits. After that they just clog up the dcache with
3016 * useless entries, possibly causing useful dcache entries to be
3017 * flushed instead. This routine is proved to flush those useless
3018 * dcache entries at process exit time.
3019 *
3020 * NOTE: This routine is just an optimization so it does not guarantee
3021 * that no dcache entries will exist at process exit time it
3022 * just makes it very unlikely that any will persist.
3023 */
3024
3025 void proc_flush_task(struct task_struct *task)
3026 {
3027 int i;
3028 struct pid *pid, *tgid;
3029 struct upid *upid;
3030
3031 pid = task_pid(task);
3032 tgid = task_tgid(task);
3033
3034 for (i = 0; i <= pid->level; i++) {
3035 upid = &pid->numbers[i];
3036 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3037 tgid->numbers[i].nr);
3038 }
3039 }
3040
3041 static int proc_pid_instantiate(struct inode *dir,
3042 struct dentry * dentry,
3043 struct task_struct *task, const void *ptr)
3044 {
3045 struct inode *inode;
3046
3047 inode = proc_pid_make_inode(dir->i_sb, task);
3048 if (!inode)
3049 goto out;
3050
3051 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3052 inode->i_op = &proc_tgid_base_inode_operations;
3053 inode->i_fop = &proc_tgid_base_operations;
3054 inode->i_flags|=S_IMMUTABLE;
3055
3056 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3057 ARRAY_SIZE(tgid_base_stuff)));
3058
3059 d_set_d_op(dentry, &pid_dentry_operations);
3060
3061 d_add(dentry, inode);
3062 /* Close the race of the process dying before we return the dentry */
3063 if (pid_revalidate(dentry, 0))
3064 return 0;
3065 out:
3066 return -ENOENT;
3067 }
3068
3069 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3070 {
3071 int result = -ENOENT;
3072 struct task_struct *task;
3073 unsigned tgid;
3074 struct pid_namespace *ns;
3075
3076 tgid = name_to_int(&dentry->d_name);
3077 if (tgid == ~0U)
3078 goto out;
3079
3080 ns = dentry->d_sb->s_fs_info;
3081 rcu_read_lock();
3082 task = find_task_by_pid_ns(tgid, ns);
3083 if (task)
3084 get_task_struct(task);
3085 rcu_read_unlock();
3086 if (!task)
3087 goto out;
3088
3089 result = proc_pid_instantiate(dir, dentry, task, NULL);
3090 put_task_struct(task);
3091 out:
3092 return ERR_PTR(result);
3093 }
3094
3095 /*
3096 * Find the first task with tgid >= tgid
3097 *
3098 */
3099 struct tgid_iter {
3100 unsigned int tgid;
3101 struct task_struct *task;
3102 };
3103 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3104 {
3105 struct pid *pid;
3106
3107 if (iter.task)
3108 put_task_struct(iter.task);
3109 rcu_read_lock();
3110 retry:
3111 iter.task = NULL;
3112 pid = find_ge_pid(iter.tgid, ns);
3113 if (pid) {
3114 iter.tgid = pid_nr_ns(pid, ns);
3115 iter.task = pid_task(pid, PIDTYPE_PID);
3116 /* What we to know is if the pid we have find is the
3117 * pid of a thread_group_leader. Testing for task
3118 * being a thread_group_leader is the obvious thing
3119 * todo but there is a window when it fails, due to
3120 * the pid transfer logic in de_thread.
3121 *
3122 * So we perform the straight forward test of seeing
3123 * if the pid we have found is the pid of a thread
3124 * group leader, and don't worry if the task we have
3125 * found doesn't happen to be a thread group leader.
3126 * As we don't care in the case of readdir.
3127 */
3128 if (!iter.task || !has_group_leader_pid(iter.task)) {
3129 iter.tgid += 1;
3130 goto retry;
3131 }
3132 get_task_struct(iter.task);
3133 }
3134 rcu_read_unlock();
3135 return iter;
3136 }
3137
3138 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3139
3140 /* for the /proc/ directory itself, after non-process stuff has been done */
3141 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3142 {
3143 struct tgid_iter iter;
3144 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3145 loff_t pos = ctx->pos;
3146
3147 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3148 return 0;
3149
3150 if (pos == TGID_OFFSET - 2) {
3151 struct inode *inode = d_inode(ns->proc_self);
3152 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3153 return 0;
3154 ctx->pos = pos = pos + 1;
3155 }
3156 if (pos == TGID_OFFSET - 1) {
3157 struct inode *inode = d_inode(ns->proc_thread_self);
3158 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3159 return 0;
3160 ctx->pos = pos = pos + 1;
3161 }
3162 iter.tgid = pos - TGID_OFFSET;
3163 iter.task = NULL;
3164 for (iter = next_tgid(ns, iter);
3165 iter.task;
3166 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3167 char name[PROC_NUMBUF];
3168 int len;
3169 if (!has_pid_permissions(ns, iter.task, 2))
3170 continue;
3171
3172 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3173 ctx->pos = iter.tgid + TGID_OFFSET;
3174 if (!proc_fill_cache(file, ctx, name, len,
3175 proc_pid_instantiate, iter.task, NULL)) {
3176 put_task_struct(iter.task);
3177 return 0;
3178 }
3179 }
3180 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3181 return 0;
3182 }
3183
3184 /*
3185 * proc_tid_comm_permission is a special permission function exclusively
3186 * used for the node /proc/<pid>/task/<tid>/comm.
3187 * It bypasses generic permission checks in the case where a task of the same
3188 * task group attempts to access the node.
3189 * The rationale behind this is that glibc and bionic access this node for
3190 * cross thread naming (pthread_set/getname_np(!self)). However, if
3191 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3192 * which locks out the cross thread naming implementation.
3193 * This function makes sure that the node is always accessible for members of
3194 * same thread group.
3195 */
3196 static int proc_tid_comm_permission(struct inode *inode, int mask)
3197 {
3198 bool is_same_tgroup;
3199 struct task_struct *task;
3200
3201 task = get_proc_task(inode);
3202 if (!task)
3203 return -ESRCH;
3204 is_same_tgroup = same_thread_group(current, task);
3205 put_task_struct(task);
3206
3207 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3208 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3209 * read or written by the members of the corresponding
3210 * thread group.
3211 */
3212 return 0;
3213 }
3214
3215 return generic_permission(inode, mask);
3216 }
3217
3218 static const struct inode_operations proc_tid_comm_inode_operations = {
3219 .permission = proc_tid_comm_permission,
3220 };
3221
3222 /*
3223 * Tasks
3224 */
3225 static const struct pid_entry tid_base_stuff[] = {
3226 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3227 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3228 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3229 #ifdef CONFIG_NET
3230 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3231 #endif
3232 REG("environ", S_IRUSR, proc_environ_operations),
3233 ONE("auxv", S_IRUSR, proc_pid_auxv),
3234 ONE("status", S_IRUGO, proc_pid_status),
3235 ONE("personality", S_IRUSR, proc_pid_personality),
3236 ONE("limits", S_IRUGO, proc_pid_limits),
3237 #ifdef CONFIG_SCHED_DEBUG
3238 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3239 #endif
3240 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3241 &proc_tid_comm_inode_operations,
3242 &proc_pid_set_comm_operations, {}),
3243 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3244 ONE("syscall", S_IRUSR, proc_pid_syscall),
3245 #endif
3246 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3247 ONE("stat", S_IRUGO, proc_tid_stat),
3248 ONE("statm", S_IRUGO, proc_pid_statm),
3249 REG("maps", S_IRUGO, proc_tid_maps_operations),
3250 #ifdef CONFIG_PROC_CHILDREN
3251 REG("children", S_IRUGO, proc_tid_children_operations),
3252 #endif
3253 #ifdef CONFIG_NUMA
3254 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3255 #endif
3256 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3257 LNK("cwd", proc_cwd_link),
3258 LNK("root", proc_root_link),
3259 LNK("exe", proc_exe_link),
3260 REG("mounts", S_IRUGO, proc_mounts_operations),
3261 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3262 #ifdef CONFIG_PROC_PAGE_MONITOR
3263 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3264 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3265 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3266 #endif
3267 #ifdef CONFIG_SECURITY
3268 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3269 #endif
3270 #ifdef CONFIG_KALLSYMS
3271 ONE("wchan", S_IRUGO, proc_pid_wchan),
3272 #endif
3273 #ifdef CONFIG_STACKTRACE
3274 ONE("stack", S_IRUSR, proc_pid_stack),
3275 #endif
3276 #ifdef CONFIG_SCHED_INFO
3277 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3278 #endif
3279 #ifdef CONFIG_LATENCYTOP
3280 REG("latency", S_IRUGO, proc_lstats_operations),
3281 #endif
3282 #ifdef CONFIG_PROC_PID_CPUSET
3283 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3284 #endif
3285 #ifdef CONFIG_CGROUPS
3286 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3287 #endif
3288 ONE("oom_score", S_IRUGO, proc_oom_score),
3289 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3290 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3291 #ifdef CONFIG_AUDITSYSCALL
3292 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3293 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3294 #endif
3295 #ifdef CONFIG_FAULT_INJECTION
3296 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3297 #endif
3298 #ifdef CONFIG_TASK_IO_ACCOUNTING
3299 ONE("io", S_IRUSR, proc_tid_io_accounting),
3300 #endif
3301 #ifdef CONFIG_HARDWALL
3302 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3303 #endif
3304 #ifdef CONFIG_USER_NS
3305 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3306 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3307 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3308 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3309 #endif
3310 };
3311
3312 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3313 {
3314 return proc_pident_readdir(file, ctx,
3315 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3316 }
3317
3318 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3319 {
3320 return proc_pident_lookup(dir, dentry,
3321 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3322 }
3323
3324 static const struct file_operations proc_tid_base_operations = {
3325 .read = generic_read_dir,
3326 .iterate_shared = proc_tid_base_readdir,
3327 .llseek = generic_file_llseek,
3328 };
3329
3330 static const struct inode_operations proc_tid_base_inode_operations = {
3331 .lookup = proc_tid_base_lookup,
3332 .getattr = pid_getattr,
3333 .setattr = proc_setattr,
3334 };
3335
3336 static int proc_task_instantiate(struct inode *dir,
3337 struct dentry *dentry, struct task_struct *task, const void *ptr)
3338 {
3339 struct inode *inode;
3340 inode = proc_pid_make_inode(dir->i_sb, task);
3341
3342 if (!inode)
3343 goto out;
3344 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3345 inode->i_op = &proc_tid_base_inode_operations;
3346 inode->i_fop = &proc_tid_base_operations;
3347 inode->i_flags|=S_IMMUTABLE;
3348
3349 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3350 ARRAY_SIZE(tid_base_stuff)));
3351
3352 d_set_d_op(dentry, &pid_dentry_operations);
3353
3354 d_add(dentry, inode);
3355 /* Close the race of the process dying before we return the dentry */
3356 if (pid_revalidate(dentry, 0))
3357 return 0;
3358 out:
3359 return -ENOENT;
3360 }
3361
3362 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3363 {
3364 int result = -ENOENT;
3365 struct task_struct *task;
3366 struct task_struct *leader = get_proc_task(dir);
3367 unsigned tid;
3368 struct pid_namespace *ns;
3369
3370 if (!leader)
3371 goto out_no_task;
3372
3373 tid = name_to_int(&dentry->d_name);
3374 if (tid == ~0U)
3375 goto out;
3376
3377 ns = dentry->d_sb->s_fs_info;
3378 rcu_read_lock();
3379 task = find_task_by_pid_ns(tid, ns);
3380 if (task)
3381 get_task_struct(task);
3382 rcu_read_unlock();
3383 if (!task)
3384 goto out;
3385 if (!same_thread_group(leader, task))
3386 goto out_drop_task;
3387
3388 result = proc_task_instantiate(dir, dentry, task, NULL);
3389 out_drop_task:
3390 put_task_struct(task);
3391 out:
3392 put_task_struct(leader);
3393 out_no_task:
3394 return ERR_PTR(result);
3395 }
3396
3397 /*
3398 * Find the first tid of a thread group to return to user space.
3399 *
3400 * Usually this is just the thread group leader, but if the users
3401 * buffer was too small or there was a seek into the middle of the
3402 * directory we have more work todo.
3403 *
3404 * In the case of a short read we start with find_task_by_pid.
3405 *
3406 * In the case of a seek we start with the leader and walk nr
3407 * threads past it.
3408 */
3409 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3410 struct pid_namespace *ns)
3411 {
3412 struct task_struct *pos, *task;
3413 unsigned long nr = f_pos;
3414
3415 if (nr != f_pos) /* 32bit overflow? */
3416 return NULL;
3417
3418 rcu_read_lock();
3419 task = pid_task(pid, PIDTYPE_PID);
3420 if (!task)
3421 goto fail;
3422
3423 /* Attempt to start with the tid of a thread */
3424 if (tid && nr) {
3425 pos = find_task_by_pid_ns(tid, ns);
3426 if (pos && same_thread_group(pos, task))
3427 goto found;
3428 }
3429
3430 /* If nr exceeds the number of threads there is nothing todo */
3431 if (nr >= get_nr_threads(task))
3432 goto fail;
3433
3434 /* If we haven't found our starting place yet start
3435 * with the leader and walk nr threads forward.
3436 */
3437 pos = task = task->group_leader;
3438 do {
3439 if (!nr--)
3440 goto found;
3441 } while_each_thread(task, pos);
3442 fail:
3443 pos = NULL;
3444 goto out;
3445 found:
3446 get_task_struct(pos);
3447 out:
3448 rcu_read_unlock();
3449 return pos;
3450 }
3451
3452 /*
3453 * Find the next thread in the thread list.
3454 * Return NULL if there is an error or no next thread.
3455 *
3456 * The reference to the input task_struct is released.
3457 */
3458 static struct task_struct *next_tid(struct task_struct *start)
3459 {
3460 struct task_struct *pos = NULL;
3461 rcu_read_lock();
3462 if (pid_alive(start)) {
3463 pos = next_thread(start);
3464 if (thread_group_leader(pos))
3465 pos = NULL;
3466 else
3467 get_task_struct(pos);
3468 }
3469 rcu_read_unlock();
3470 put_task_struct(start);
3471 return pos;
3472 }
3473
3474 /* for the /proc/TGID/task/ directories */
3475 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3476 {
3477 struct inode *inode = file_inode(file);
3478 struct task_struct *task;
3479 struct pid_namespace *ns;
3480 int tid;
3481
3482 if (proc_inode_is_dead(inode))
3483 return -ENOENT;
3484
3485 if (!dir_emit_dots(file, ctx))
3486 return 0;
3487
3488 /* f_version caches the tgid value that the last readdir call couldn't
3489 * return. lseek aka telldir automagically resets f_version to 0.
3490 */
3491 ns = inode->i_sb->s_fs_info;
3492 tid = (int)file->f_version;
3493 file->f_version = 0;
3494 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3495 task;
3496 task = next_tid(task), ctx->pos++) {
3497 char name[PROC_NUMBUF];
3498 int len;
3499 tid = task_pid_nr_ns(task, ns);
3500 len = snprintf(name, sizeof(name), "%d", tid);
3501 if (!proc_fill_cache(file, ctx, name, len,
3502 proc_task_instantiate, task, NULL)) {
3503 /* returning this tgid failed, save it as the first
3504 * pid for the next readir call */
3505 file->f_version = (u64)tid;
3506 put_task_struct(task);
3507 break;
3508 }
3509 }
3510
3511 return 0;
3512 }
3513
3514 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3515 {
3516 struct inode *inode = d_inode(dentry);
3517 struct task_struct *p = get_proc_task(inode);
3518 generic_fillattr(inode, stat);
3519
3520 if (p) {
3521 stat->nlink += get_nr_threads(p);
3522 put_task_struct(p);
3523 }
3524
3525 return 0;
3526 }
3527
3528 static const struct inode_operations proc_task_inode_operations = {
3529 .lookup = proc_task_lookup,
3530 .getattr = proc_task_getattr,
3531 .setattr = proc_setattr,
3532 .permission = proc_pid_permission,
3533 };
3534
3535 static const struct file_operations proc_task_operations = {
3536 .read = generic_read_dir,
3537 .iterate_shared = proc_task_readdir,
3538 .llseek = generic_file_llseek,
3539 };
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