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Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[deliverable/linux.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);
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) && !lookup_symbol_name(wchan, symname))
434 seq_printf(m, "%s", symname);
435 else
436 seq_putc(m, '0');
437
438 return 0;
439 }
440 #endif /* CONFIG_KALLSYMS */
441
442 static int lock_trace(struct task_struct *task)
443 {
444 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
445 if (err)
446 return err;
447 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
448 mutex_unlock(&task->signal->cred_guard_mutex);
449 return -EPERM;
450 }
451 return 0;
452 }
453
454 static void unlock_trace(struct task_struct *task)
455 {
456 mutex_unlock(&task->signal->cred_guard_mutex);
457 }
458
459 #ifdef CONFIG_STACKTRACE
460
461 #define MAX_STACK_TRACE_DEPTH 64
462
463 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
464 struct pid *pid, struct task_struct *task)
465 {
466 struct stack_trace trace;
467 unsigned long *entries;
468 int err;
469 int i;
470
471 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
472 if (!entries)
473 return -ENOMEM;
474
475 trace.nr_entries = 0;
476 trace.max_entries = MAX_STACK_TRACE_DEPTH;
477 trace.entries = entries;
478 trace.skip = 0;
479
480 err = lock_trace(task);
481 if (!err) {
482 save_stack_trace_tsk(task, &trace);
483
484 for (i = 0; i < trace.nr_entries; i++) {
485 seq_printf(m, "[<%pK>] %pS\n",
486 (void *)entries[i], (void *)entries[i]);
487 }
488 unlock_trace(task);
489 }
490 kfree(entries);
491
492 return err;
493 }
494 #endif
495
496 #ifdef CONFIG_SCHED_INFO
497 /*
498 * Provides /proc/PID/schedstat
499 */
500 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
501 struct pid *pid, struct task_struct *task)
502 {
503 if (unlikely(!sched_info_on()))
504 seq_printf(m, "0 0 0\n");
505 else
506 seq_printf(m, "%llu %llu %lu\n",
507 (unsigned long long)task->se.sum_exec_runtime,
508 (unsigned long long)task->sched_info.run_delay,
509 task->sched_info.pcount);
510
511 return 0;
512 }
513 #endif
514
515 #ifdef CONFIG_LATENCYTOP
516 static int lstats_show_proc(struct seq_file *m, void *v)
517 {
518 int i;
519 struct inode *inode = m->private;
520 struct task_struct *task = get_proc_task(inode);
521
522 if (!task)
523 return -ESRCH;
524 seq_puts(m, "Latency Top version : v0.1\n");
525 for (i = 0; i < 32; i++) {
526 struct latency_record *lr = &task->latency_record[i];
527 if (lr->backtrace[0]) {
528 int q;
529 seq_printf(m, "%i %li %li",
530 lr->count, lr->time, lr->max);
531 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
532 unsigned long bt = lr->backtrace[q];
533 if (!bt)
534 break;
535 if (bt == ULONG_MAX)
536 break;
537 seq_printf(m, " %ps", (void *)bt);
538 }
539 seq_putc(m, '\n');
540 }
541
542 }
543 put_task_struct(task);
544 return 0;
545 }
546
547 static int lstats_open(struct inode *inode, struct file *file)
548 {
549 return single_open(file, lstats_show_proc, inode);
550 }
551
552 static ssize_t lstats_write(struct file *file, const char __user *buf,
553 size_t count, loff_t *offs)
554 {
555 struct task_struct *task = get_proc_task(file_inode(file));
556
557 if (!task)
558 return -ESRCH;
559 clear_all_latency_tracing(task);
560 put_task_struct(task);
561
562 return count;
563 }
564
565 static const struct file_operations proc_lstats_operations = {
566 .open = lstats_open,
567 .read = seq_read,
568 .write = lstats_write,
569 .llseek = seq_lseek,
570 .release = single_release,
571 };
572
573 #endif
574
575 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
576 struct pid *pid, struct task_struct *task)
577 {
578 unsigned long totalpages = totalram_pages + total_swap_pages;
579 unsigned long points = 0;
580
581 read_lock(&tasklist_lock);
582 if (pid_alive(task))
583 points = oom_badness(task, NULL, NULL, totalpages) *
584 1000 / totalpages;
585 read_unlock(&tasklist_lock);
586 seq_printf(m, "%lu\n", points);
587
588 return 0;
589 }
590
591 struct limit_names {
592 const char *name;
593 const char *unit;
594 };
595
596 static const struct limit_names lnames[RLIM_NLIMITS] = {
597 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
598 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
599 [RLIMIT_DATA] = {"Max data size", "bytes"},
600 [RLIMIT_STACK] = {"Max stack size", "bytes"},
601 [RLIMIT_CORE] = {"Max core file size", "bytes"},
602 [RLIMIT_RSS] = {"Max resident set", "bytes"},
603 [RLIMIT_NPROC] = {"Max processes", "processes"},
604 [RLIMIT_NOFILE] = {"Max open files", "files"},
605 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
606 [RLIMIT_AS] = {"Max address space", "bytes"},
607 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
608 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
609 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
610 [RLIMIT_NICE] = {"Max nice priority", NULL},
611 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
612 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
613 };
614
615 /* Display limits for a process */
616 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
617 struct pid *pid, struct task_struct *task)
618 {
619 unsigned int i;
620 unsigned long flags;
621
622 struct rlimit rlim[RLIM_NLIMITS];
623
624 if (!lock_task_sighand(task, &flags))
625 return 0;
626 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
627 unlock_task_sighand(task, &flags);
628
629 /*
630 * print the file header
631 */
632 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
633 "Limit", "Soft Limit", "Hard Limit", "Units");
634
635 for (i = 0; i < RLIM_NLIMITS; i++) {
636 if (rlim[i].rlim_cur == RLIM_INFINITY)
637 seq_printf(m, "%-25s %-20s ",
638 lnames[i].name, "unlimited");
639 else
640 seq_printf(m, "%-25s %-20lu ",
641 lnames[i].name, rlim[i].rlim_cur);
642
643 if (rlim[i].rlim_max == RLIM_INFINITY)
644 seq_printf(m, "%-20s ", "unlimited");
645 else
646 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
647
648 if (lnames[i].unit)
649 seq_printf(m, "%-10s\n", lnames[i].unit);
650 else
651 seq_putc(m, '\n');
652 }
653
654 return 0;
655 }
656
657 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
658 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
659 struct pid *pid, struct task_struct *task)
660 {
661 long nr;
662 unsigned long args[6], sp, pc;
663 int res;
664
665 res = lock_trace(task);
666 if (res)
667 return res;
668
669 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
670 seq_puts(m, "running\n");
671 else if (nr < 0)
672 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
673 else
674 seq_printf(m,
675 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
676 nr,
677 args[0], args[1], args[2], args[3], args[4], args[5],
678 sp, pc);
679 unlock_trace(task);
680
681 return 0;
682 }
683 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
684
685 /************************************************************************/
686 /* Here the fs part begins */
687 /************************************************************************/
688
689 /* permission checks */
690 static int proc_fd_access_allowed(struct inode *inode)
691 {
692 struct task_struct *task;
693 int allowed = 0;
694 /* Allow access to a task's file descriptors if it is us or we
695 * may use ptrace attach to the process and find out that
696 * information.
697 */
698 task = get_proc_task(inode);
699 if (task) {
700 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
701 put_task_struct(task);
702 }
703 return allowed;
704 }
705
706 int proc_setattr(struct dentry *dentry, struct iattr *attr)
707 {
708 int error;
709 struct inode *inode = d_inode(dentry);
710
711 if (attr->ia_valid & ATTR_MODE)
712 return -EPERM;
713
714 error = inode_change_ok(inode, attr);
715 if (error)
716 return error;
717
718 setattr_copy(inode, attr);
719 mark_inode_dirty(inode);
720 return 0;
721 }
722
723 /*
724 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
725 * or euid/egid (for hide_pid_min=2)?
726 */
727 static bool has_pid_permissions(struct pid_namespace *pid,
728 struct task_struct *task,
729 int hide_pid_min)
730 {
731 if (pid->hide_pid < hide_pid_min)
732 return true;
733 if (in_group_p(pid->pid_gid))
734 return true;
735 return ptrace_may_access(task, PTRACE_MODE_READ);
736 }
737
738
739 static int proc_pid_permission(struct inode *inode, int mask)
740 {
741 struct pid_namespace *pid = inode->i_sb->s_fs_info;
742 struct task_struct *task;
743 bool has_perms;
744
745 task = get_proc_task(inode);
746 if (!task)
747 return -ESRCH;
748 has_perms = has_pid_permissions(pid, task, 1);
749 put_task_struct(task);
750
751 if (!has_perms) {
752 if (pid->hide_pid == 2) {
753 /*
754 * Let's make getdents(), stat(), and open()
755 * consistent with each other. If a process
756 * may not stat() a file, it shouldn't be seen
757 * in procfs at all.
758 */
759 return -ENOENT;
760 }
761
762 return -EPERM;
763 }
764 return generic_permission(inode, mask);
765 }
766
767
768
769 static const struct inode_operations proc_def_inode_operations = {
770 .setattr = proc_setattr,
771 };
772
773 static int proc_single_show(struct seq_file *m, void *v)
774 {
775 struct inode *inode = m->private;
776 struct pid_namespace *ns;
777 struct pid *pid;
778 struct task_struct *task;
779 int ret;
780
781 ns = inode->i_sb->s_fs_info;
782 pid = proc_pid(inode);
783 task = get_pid_task(pid, PIDTYPE_PID);
784 if (!task)
785 return -ESRCH;
786
787 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
788
789 put_task_struct(task);
790 return ret;
791 }
792
793 static int proc_single_open(struct inode *inode, struct file *filp)
794 {
795 return single_open(filp, proc_single_show, inode);
796 }
797
798 static const struct file_operations proc_single_file_operations = {
799 .open = proc_single_open,
800 .read = seq_read,
801 .llseek = seq_lseek,
802 .release = single_release,
803 };
804
805
806 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
807 {
808 struct task_struct *task = get_proc_task(inode);
809 struct mm_struct *mm = ERR_PTR(-ESRCH);
810
811 if (task) {
812 mm = mm_access(task, mode);
813 put_task_struct(task);
814
815 if (!IS_ERR_OR_NULL(mm)) {
816 /* ensure this mm_struct can't be freed */
817 atomic_inc(&mm->mm_count);
818 /* but do not pin its memory */
819 mmput(mm);
820 }
821 }
822
823 return mm;
824 }
825
826 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
827 {
828 struct mm_struct *mm = proc_mem_open(inode, mode);
829
830 if (IS_ERR(mm))
831 return PTR_ERR(mm);
832
833 file->private_data = mm;
834 return 0;
835 }
836
837 static int mem_open(struct inode *inode, struct file *file)
838 {
839 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
840
841 /* OK to pass negative loff_t, we can catch out-of-range */
842 file->f_mode |= FMODE_UNSIGNED_OFFSET;
843
844 return ret;
845 }
846
847 static ssize_t mem_rw(struct file *file, char __user *buf,
848 size_t count, loff_t *ppos, int write)
849 {
850 struct mm_struct *mm = file->private_data;
851 unsigned long addr = *ppos;
852 ssize_t copied;
853 char *page;
854
855 if (!mm)
856 return 0;
857
858 page = (char *)__get_free_page(GFP_TEMPORARY);
859 if (!page)
860 return -ENOMEM;
861
862 copied = 0;
863 if (!atomic_inc_not_zero(&mm->mm_users))
864 goto free;
865
866 while (count > 0) {
867 int this_len = min_t(int, count, PAGE_SIZE);
868
869 if (write && copy_from_user(page, buf, this_len)) {
870 copied = -EFAULT;
871 break;
872 }
873
874 this_len = access_remote_vm(mm, addr, page, this_len, write);
875 if (!this_len) {
876 if (!copied)
877 copied = -EIO;
878 break;
879 }
880
881 if (!write && copy_to_user(buf, page, this_len)) {
882 copied = -EFAULT;
883 break;
884 }
885
886 buf += this_len;
887 addr += this_len;
888 copied += this_len;
889 count -= this_len;
890 }
891 *ppos = addr;
892
893 mmput(mm);
894 free:
895 free_page((unsigned long) page);
896 return copied;
897 }
898
899 static ssize_t mem_read(struct file *file, char __user *buf,
900 size_t count, loff_t *ppos)
901 {
902 return mem_rw(file, buf, count, ppos, 0);
903 }
904
905 static ssize_t mem_write(struct file *file, const char __user *buf,
906 size_t count, loff_t *ppos)
907 {
908 return mem_rw(file, (char __user*)buf, count, ppos, 1);
909 }
910
911 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
912 {
913 switch (orig) {
914 case 0:
915 file->f_pos = offset;
916 break;
917 case 1:
918 file->f_pos += offset;
919 break;
920 default:
921 return -EINVAL;
922 }
923 force_successful_syscall_return();
924 return file->f_pos;
925 }
926
927 static int mem_release(struct inode *inode, struct file *file)
928 {
929 struct mm_struct *mm = file->private_data;
930 if (mm)
931 mmdrop(mm);
932 return 0;
933 }
934
935 static const struct file_operations proc_mem_operations = {
936 .llseek = mem_lseek,
937 .read = mem_read,
938 .write = mem_write,
939 .open = mem_open,
940 .release = mem_release,
941 };
942
943 static int environ_open(struct inode *inode, struct file *file)
944 {
945 return __mem_open(inode, file, PTRACE_MODE_READ);
946 }
947
948 static ssize_t environ_read(struct file *file, char __user *buf,
949 size_t count, loff_t *ppos)
950 {
951 char *page;
952 unsigned long src = *ppos;
953 int ret = 0;
954 struct mm_struct *mm = file->private_data;
955
956 if (!mm)
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 while (count > 0) {
967 size_t this_len, max_len;
968 int retval;
969
970 if (src >= (mm->env_end - mm->env_start))
971 break;
972
973 this_len = mm->env_end - (mm->env_start + src);
974
975 max_len = min_t(size_t, PAGE_SIZE, count);
976 this_len = min(max_len, this_len);
977
978 retval = access_remote_vm(mm, (mm->env_start + src),
979 page, this_len, 0);
980
981 if (retval <= 0) {
982 ret = retval;
983 break;
984 }
985
986 if (copy_to_user(buf, page, retval)) {
987 ret = -EFAULT;
988 break;
989 }
990
991 ret += retval;
992 src += retval;
993 buf += retval;
994 count -= retval;
995 }
996 *ppos = src;
997 mmput(mm);
998
999 free:
1000 free_page((unsigned long) page);
1001 return ret;
1002 }
1003
1004 static const struct file_operations proc_environ_operations = {
1005 .open = environ_open,
1006 .read = environ_read,
1007 .llseek = generic_file_llseek,
1008 .release = mem_release,
1009 };
1010
1011 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1012 loff_t *ppos)
1013 {
1014 struct task_struct *task = get_proc_task(file_inode(file));
1015 char buffer[PROC_NUMBUF];
1016 int oom_adj = OOM_ADJUST_MIN;
1017 size_t len;
1018 unsigned long flags;
1019
1020 if (!task)
1021 return -ESRCH;
1022 if (lock_task_sighand(task, &flags)) {
1023 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1024 oom_adj = OOM_ADJUST_MAX;
1025 else
1026 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1027 OOM_SCORE_ADJ_MAX;
1028 unlock_task_sighand(task, &flags);
1029 }
1030 put_task_struct(task);
1031 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1032 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1033 }
1034
1035 /*
1036 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1037 * kernels. The effective policy is defined by oom_score_adj, which has a
1038 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1039 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1040 * Processes that become oom disabled via oom_adj will still be oom disabled
1041 * with this implementation.
1042 *
1043 * oom_adj cannot be removed since existing userspace binaries use it.
1044 */
1045 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1046 size_t count, loff_t *ppos)
1047 {
1048 struct task_struct *task;
1049 char buffer[PROC_NUMBUF];
1050 int oom_adj;
1051 unsigned long flags;
1052 int err;
1053
1054 memset(buffer, 0, sizeof(buffer));
1055 if (count > sizeof(buffer) - 1)
1056 count = sizeof(buffer) - 1;
1057 if (copy_from_user(buffer, buf, count)) {
1058 err = -EFAULT;
1059 goto out;
1060 }
1061
1062 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1063 if (err)
1064 goto out;
1065 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1066 oom_adj != OOM_DISABLE) {
1067 err = -EINVAL;
1068 goto out;
1069 }
1070
1071 task = get_proc_task(file_inode(file));
1072 if (!task) {
1073 err = -ESRCH;
1074 goto out;
1075 }
1076
1077 task_lock(task);
1078 if (!task->mm) {
1079 err = -EINVAL;
1080 goto err_task_lock;
1081 }
1082
1083 if (!lock_task_sighand(task, &flags)) {
1084 err = -ESRCH;
1085 goto err_task_lock;
1086 }
1087
1088 /*
1089 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1090 * value is always attainable.
1091 */
1092 if (oom_adj == OOM_ADJUST_MAX)
1093 oom_adj = OOM_SCORE_ADJ_MAX;
1094 else
1095 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1096
1097 if (oom_adj < task->signal->oom_score_adj &&
1098 !capable(CAP_SYS_RESOURCE)) {
1099 err = -EACCES;
1100 goto err_sighand;
1101 }
1102
1103 /*
1104 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1105 * /proc/pid/oom_score_adj instead.
1106 */
1107 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1108 current->comm, task_pid_nr(current), task_pid_nr(task),
1109 task_pid_nr(task));
1110
1111 task->signal->oom_score_adj = oom_adj;
1112 trace_oom_score_adj_update(task);
1113 err_sighand:
1114 unlock_task_sighand(task, &flags);
1115 err_task_lock:
1116 task_unlock(task);
1117 put_task_struct(task);
1118 out:
1119 return err < 0 ? err : count;
1120 }
1121
1122 static const struct file_operations proc_oom_adj_operations = {
1123 .read = oom_adj_read,
1124 .write = oom_adj_write,
1125 .llseek = generic_file_llseek,
1126 };
1127
1128 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1129 size_t count, loff_t *ppos)
1130 {
1131 struct task_struct *task = get_proc_task(file_inode(file));
1132 char buffer[PROC_NUMBUF];
1133 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1134 unsigned long flags;
1135 size_t len;
1136
1137 if (!task)
1138 return -ESRCH;
1139 if (lock_task_sighand(task, &flags)) {
1140 oom_score_adj = task->signal->oom_score_adj;
1141 unlock_task_sighand(task, &flags);
1142 }
1143 put_task_struct(task);
1144 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1145 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1146 }
1147
1148 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1149 size_t count, loff_t *ppos)
1150 {
1151 struct task_struct *task;
1152 char buffer[PROC_NUMBUF];
1153 unsigned long flags;
1154 int oom_score_adj;
1155 int err;
1156
1157 memset(buffer, 0, sizeof(buffer));
1158 if (count > sizeof(buffer) - 1)
1159 count = sizeof(buffer) - 1;
1160 if (copy_from_user(buffer, buf, count)) {
1161 err = -EFAULT;
1162 goto out;
1163 }
1164
1165 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1166 if (err)
1167 goto out;
1168 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1169 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1170 err = -EINVAL;
1171 goto out;
1172 }
1173
1174 task = get_proc_task(file_inode(file));
1175 if (!task) {
1176 err = -ESRCH;
1177 goto out;
1178 }
1179
1180 task_lock(task);
1181 if (!task->mm) {
1182 err = -EINVAL;
1183 goto err_task_lock;
1184 }
1185
1186 if (!lock_task_sighand(task, &flags)) {
1187 err = -ESRCH;
1188 goto err_task_lock;
1189 }
1190
1191 if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
1192 !capable(CAP_SYS_RESOURCE)) {
1193 err = -EACCES;
1194 goto err_sighand;
1195 }
1196
1197 task->signal->oom_score_adj = (short)oom_score_adj;
1198 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1199 task->signal->oom_score_adj_min = (short)oom_score_adj;
1200 trace_oom_score_adj_update(task);
1201
1202 err_sighand:
1203 unlock_task_sighand(task, &flags);
1204 err_task_lock:
1205 task_unlock(task);
1206 put_task_struct(task);
1207 out:
1208 return err < 0 ? err : count;
1209 }
1210
1211 static const struct file_operations proc_oom_score_adj_operations = {
1212 .read = oom_score_adj_read,
1213 .write = oom_score_adj_write,
1214 .llseek = default_llseek,
1215 };
1216
1217 #ifdef CONFIG_AUDITSYSCALL
1218 #define TMPBUFLEN 21
1219 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1220 size_t count, loff_t *ppos)
1221 {
1222 struct inode * inode = file_inode(file);
1223 struct task_struct *task = get_proc_task(inode);
1224 ssize_t length;
1225 char tmpbuf[TMPBUFLEN];
1226
1227 if (!task)
1228 return -ESRCH;
1229 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1230 from_kuid(file->f_cred->user_ns,
1231 audit_get_loginuid(task)));
1232 put_task_struct(task);
1233 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1234 }
1235
1236 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1237 size_t count, loff_t *ppos)
1238 {
1239 struct inode * inode = file_inode(file);
1240 uid_t loginuid;
1241 kuid_t kloginuid;
1242 int rv;
1243
1244 rcu_read_lock();
1245 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1246 rcu_read_unlock();
1247 return -EPERM;
1248 }
1249 rcu_read_unlock();
1250
1251 if (*ppos != 0) {
1252 /* No partial writes. */
1253 return -EINVAL;
1254 }
1255
1256 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1257 if (rv < 0)
1258 return rv;
1259
1260 /* is userspace tring to explicitly UNSET the loginuid? */
1261 if (loginuid == AUDIT_UID_UNSET) {
1262 kloginuid = INVALID_UID;
1263 } else {
1264 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1265 if (!uid_valid(kloginuid))
1266 return -EINVAL;
1267 }
1268
1269 rv = audit_set_loginuid(kloginuid);
1270 if (rv < 0)
1271 return rv;
1272 return count;
1273 }
1274
1275 static const struct file_operations proc_loginuid_operations = {
1276 .read = proc_loginuid_read,
1277 .write = proc_loginuid_write,
1278 .llseek = generic_file_llseek,
1279 };
1280
1281 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1282 size_t count, loff_t *ppos)
1283 {
1284 struct inode * inode = file_inode(file);
1285 struct task_struct *task = get_proc_task(inode);
1286 ssize_t length;
1287 char tmpbuf[TMPBUFLEN];
1288
1289 if (!task)
1290 return -ESRCH;
1291 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1292 audit_get_sessionid(task));
1293 put_task_struct(task);
1294 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1295 }
1296
1297 static const struct file_operations proc_sessionid_operations = {
1298 .read = proc_sessionid_read,
1299 .llseek = generic_file_llseek,
1300 };
1301 #endif
1302
1303 #ifdef CONFIG_FAULT_INJECTION
1304 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1305 size_t count, loff_t *ppos)
1306 {
1307 struct task_struct *task = get_proc_task(file_inode(file));
1308 char buffer[PROC_NUMBUF];
1309 size_t len;
1310 int make_it_fail;
1311
1312 if (!task)
1313 return -ESRCH;
1314 make_it_fail = task->make_it_fail;
1315 put_task_struct(task);
1316
1317 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1318
1319 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1320 }
1321
1322 static ssize_t proc_fault_inject_write(struct file * file,
1323 const char __user * buf, size_t count, loff_t *ppos)
1324 {
1325 struct task_struct *task;
1326 char buffer[PROC_NUMBUF];
1327 int make_it_fail;
1328 int rv;
1329
1330 if (!capable(CAP_SYS_RESOURCE))
1331 return -EPERM;
1332 memset(buffer, 0, sizeof(buffer));
1333 if (count > sizeof(buffer) - 1)
1334 count = sizeof(buffer) - 1;
1335 if (copy_from_user(buffer, buf, count))
1336 return -EFAULT;
1337 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1338 if (rv < 0)
1339 return rv;
1340 if (make_it_fail < 0 || make_it_fail > 1)
1341 return -EINVAL;
1342
1343 task = get_proc_task(file_inode(file));
1344 if (!task)
1345 return -ESRCH;
1346 task->make_it_fail = make_it_fail;
1347 put_task_struct(task);
1348
1349 return count;
1350 }
1351
1352 static const struct file_operations proc_fault_inject_operations = {
1353 .read = proc_fault_inject_read,
1354 .write = proc_fault_inject_write,
1355 .llseek = generic_file_llseek,
1356 };
1357 #endif
1358
1359
1360 #ifdef CONFIG_SCHED_DEBUG
1361 /*
1362 * Print out various scheduling related per-task fields:
1363 */
1364 static int sched_show(struct seq_file *m, void *v)
1365 {
1366 struct inode *inode = m->private;
1367 struct task_struct *p;
1368
1369 p = get_proc_task(inode);
1370 if (!p)
1371 return -ESRCH;
1372 proc_sched_show_task(p, m);
1373
1374 put_task_struct(p);
1375
1376 return 0;
1377 }
1378
1379 static ssize_t
1380 sched_write(struct file *file, const char __user *buf,
1381 size_t count, loff_t *offset)
1382 {
1383 struct inode *inode = file_inode(file);
1384 struct task_struct *p;
1385
1386 p = get_proc_task(inode);
1387 if (!p)
1388 return -ESRCH;
1389 proc_sched_set_task(p);
1390
1391 put_task_struct(p);
1392
1393 return count;
1394 }
1395
1396 static int sched_open(struct inode *inode, struct file *filp)
1397 {
1398 return single_open(filp, sched_show, inode);
1399 }
1400
1401 static const struct file_operations proc_pid_sched_operations = {
1402 .open = sched_open,
1403 .read = seq_read,
1404 .write = sched_write,
1405 .llseek = seq_lseek,
1406 .release = single_release,
1407 };
1408
1409 #endif
1410
1411 #ifdef CONFIG_SCHED_AUTOGROUP
1412 /*
1413 * Print out autogroup related information:
1414 */
1415 static int sched_autogroup_show(struct seq_file *m, void *v)
1416 {
1417 struct inode *inode = m->private;
1418 struct task_struct *p;
1419
1420 p = get_proc_task(inode);
1421 if (!p)
1422 return -ESRCH;
1423 proc_sched_autogroup_show_task(p, m);
1424
1425 put_task_struct(p);
1426
1427 return 0;
1428 }
1429
1430 static ssize_t
1431 sched_autogroup_write(struct file *file, const char __user *buf,
1432 size_t count, loff_t *offset)
1433 {
1434 struct inode *inode = file_inode(file);
1435 struct task_struct *p;
1436 char buffer[PROC_NUMBUF];
1437 int nice;
1438 int err;
1439
1440 memset(buffer, 0, sizeof(buffer));
1441 if (count > sizeof(buffer) - 1)
1442 count = sizeof(buffer) - 1;
1443 if (copy_from_user(buffer, buf, count))
1444 return -EFAULT;
1445
1446 err = kstrtoint(strstrip(buffer), 0, &nice);
1447 if (err < 0)
1448 return err;
1449
1450 p = get_proc_task(inode);
1451 if (!p)
1452 return -ESRCH;
1453
1454 err = proc_sched_autogroup_set_nice(p, nice);
1455 if (err)
1456 count = err;
1457
1458 put_task_struct(p);
1459
1460 return count;
1461 }
1462
1463 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1464 {
1465 int ret;
1466
1467 ret = single_open(filp, sched_autogroup_show, NULL);
1468 if (!ret) {
1469 struct seq_file *m = filp->private_data;
1470
1471 m->private = inode;
1472 }
1473 return ret;
1474 }
1475
1476 static const struct file_operations proc_pid_sched_autogroup_operations = {
1477 .open = sched_autogroup_open,
1478 .read = seq_read,
1479 .write = sched_autogroup_write,
1480 .llseek = seq_lseek,
1481 .release = single_release,
1482 };
1483
1484 #endif /* CONFIG_SCHED_AUTOGROUP */
1485
1486 static ssize_t comm_write(struct file *file, const char __user *buf,
1487 size_t count, loff_t *offset)
1488 {
1489 struct inode *inode = file_inode(file);
1490 struct task_struct *p;
1491 char buffer[TASK_COMM_LEN];
1492 const size_t maxlen = sizeof(buffer) - 1;
1493
1494 memset(buffer, 0, sizeof(buffer));
1495 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1496 return -EFAULT;
1497
1498 p = get_proc_task(inode);
1499 if (!p)
1500 return -ESRCH;
1501
1502 if (same_thread_group(current, p))
1503 set_task_comm(p, buffer);
1504 else
1505 count = -EINVAL;
1506
1507 put_task_struct(p);
1508
1509 return count;
1510 }
1511
1512 static int comm_show(struct seq_file *m, void *v)
1513 {
1514 struct inode *inode = m->private;
1515 struct task_struct *p;
1516
1517 p = get_proc_task(inode);
1518 if (!p)
1519 return -ESRCH;
1520
1521 task_lock(p);
1522 seq_printf(m, "%s\n", p->comm);
1523 task_unlock(p);
1524
1525 put_task_struct(p);
1526
1527 return 0;
1528 }
1529
1530 static int comm_open(struct inode *inode, struct file *filp)
1531 {
1532 return single_open(filp, comm_show, inode);
1533 }
1534
1535 static const struct file_operations proc_pid_set_comm_operations = {
1536 .open = comm_open,
1537 .read = seq_read,
1538 .write = comm_write,
1539 .llseek = seq_lseek,
1540 .release = single_release,
1541 };
1542
1543 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1544 {
1545 struct task_struct *task;
1546 struct mm_struct *mm;
1547 struct file *exe_file;
1548
1549 task = get_proc_task(d_inode(dentry));
1550 if (!task)
1551 return -ENOENT;
1552 mm = get_task_mm(task);
1553 put_task_struct(task);
1554 if (!mm)
1555 return -ENOENT;
1556 exe_file = get_mm_exe_file(mm);
1557 mmput(mm);
1558 if (exe_file) {
1559 *exe_path = exe_file->f_path;
1560 path_get(&exe_file->f_path);
1561 fput(exe_file);
1562 return 0;
1563 } else
1564 return -ENOENT;
1565 }
1566
1567 static const char *proc_pid_get_link(struct dentry *dentry,
1568 struct inode *inode,
1569 struct delayed_call *done)
1570 {
1571 struct path path;
1572 int error = -EACCES;
1573
1574 if (!dentry)
1575 return ERR_PTR(-ECHILD);
1576
1577 /* Are we allowed to snoop on the tasks file descriptors? */
1578 if (!proc_fd_access_allowed(inode))
1579 goto out;
1580
1581 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1582 if (error)
1583 goto out;
1584
1585 nd_jump_link(&path);
1586 return NULL;
1587 out:
1588 return ERR_PTR(error);
1589 }
1590
1591 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1592 {
1593 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1594 char *pathname;
1595 int len;
1596
1597 if (!tmp)
1598 return -ENOMEM;
1599
1600 pathname = d_path(path, tmp, PAGE_SIZE);
1601 len = PTR_ERR(pathname);
1602 if (IS_ERR(pathname))
1603 goto out;
1604 len = tmp + PAGE_SIZE - 1 - pathname;
1605
1606 if (len > buflen)
1607 len = buflen;
1608 if (copy_to_user(buffer, pathname, len))
1609 len = -EFAULT;
1610 out:
1611 free_page((unsigned long)tmp);
1612 return len;
1613 }
1614
1615 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1616 {
1617 int error = -EACCES;
1618 struct inode *inode = d_inode(dentry);
1619 struct path path;
1620
1621 /* Are we allowed to snoop on the tasks file descriptors? */
1622 if (!proc_fd_access_allowed(inode))
1623 goto out;
1624
1625 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1626 if (error)
1627 goto out;
1628
1629 error = do_proc_readlink(&path, buffer, buflen);
1630 path_put(&path);
1631 out:
1632 return error;
1633 }
1634
1635 const struct inode_operations proc_pid_link_inode_operations = {
1636 .readlink = proc_pid_readlink,
1637 .get_link = proc_pid_get_link,
1638 .setattr = proc_setattr,
1639 };
1640
1641
1642 /* building an inode */
1643
1644 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1645 {
1646 struct inode * inode;
1647 struct proc_inode *ei;
1648 const struct cred *cred;
1649
1650 /* We need a new inode */
1651
1652 inode = new_inode(sb);
1653 if (!inode)
1654 goto out;
1655
1656 /* Common stuff */
1657 ei = PROC_I(inode);
1658 inode->i_ino = get_next_ino();
1659 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1660 inode->i_op = &proc_def_inode_operations;
1661
1662 /*
1663 * grab the reference to task.
1664 */
1665 ei->pid = get_task_pid(task, PIDTYPE_PID);
1666 if (!ei->pid)
1667 goto out_unlock;
1668
1669 if (task_dumpable(task)) {
1670 rcu_read_lock();
1671 cred = __task_cred(task);
1672 inode->i_uid = cred->euid;
1673 inode->i_gid = cred->egid;
1674 rcu_read_unlock();
1675 }
1676 security_task_to_inode(task, inode);
1677
1678 out:
1679 return inode;
1680
1681 out_unlock:
1682 iput(inode);
1683 return NULL;
1684 }
1685
1686 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1687 {
1688 struct inode *inode = d_inode(dentry);
1689 struct task_struct *task;
1690 const struct cred *cred;
1691 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1692
1693 generic_fillattr(inode, stat);
1694
1695 rcu_read_lock();
1696 stat->uid = GLOBAL_ROOT_UID;
1697 stat->gid = GLOBAL_ROOT_GID;
1698 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1699 if (task) {
1700 if (!has_pid_permissions(pid, task, 2)) {
1701 rcu_read_unlock();
1702 /*
1703 * This doesn't prevent learning whether PID exists,
1704 * it only makes getattr() consistent with readdir().
1705 */
1706 return -ENOENT;
1707 }
1708 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1709 task_dumpable(task)) {
1710 cred = __task_cred(task);
1711 stat->uid = cred->euid;
1712 stat->gid = cred->egid;
1713 }
1714 }
1715 rcu_read_unlock();
1716 return 0;
1717 }
1718
1719 /* dentry stuff */
1720
1721 /*
1722 * Exceptional case: normally we are not allowed to unhash a busy
1723 * directory. In this case, however, we can do it - no aliasing problems
1724 * due to the way we treat inodes.
1725 *
1726 * Rewrite the inode's ownerships here because the owning task may have
1727 * performed a setuid(), etc.
1728 *
1729 * Before the /proc/pid/status file was created the only way to read
1730 * the effective uid of a /process was to stat /proc/pid. Reading
1731 * /proc/pid/status is slow enough that procps and other packages
1732 * kept stating /proc/pid. To keep the rules in /proc simple I have
1733 * made this apply to all per process world readable and executable
1734 * directories.
1735 */
1736 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1737 {
1738 struct inode *inode;
1739 struct task_struct *task;
1740 const struct cred *cred;
1741
1742 if (flags & LOOKUP_RCU)
1743 return -ECHILD;
1744
1745 inode = d_inode(dentry);
1746 task = get_proc_task(inode);
1747
1748 if (task) {
1749 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1750 task_dumpable(task)) {
1751 rcu_read_lock();
1752 cred = __task_cred(task);
1753 inode->i_uid = cred->euid;
1754 inode->i_gid = cred->egid;
1755 rcu_read_unlock();
1756 } else {
1757 inode->i_uid = GLOBAL_ROOT_UID;
1758 inode->i_gid = GLOBAL_ROOT_GID;
1759 }
1760 inode->i_mode &= ~(S_ISUID | S_ISGID);
1761 security_task_to_inode(task, inode);
1762 put_task_struct(task);
1763 return 1;
1764 }
1765 return 0;
1766 }
1767
1768 static inline bool proc_inode_is_dead(struct inode *inode)
1769 {
1770 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1771 }
1772
1773 int pid_delete_dentry(const struct dentry *dentry)
1774 {
1775 /* Is the task we represent dead?
1776 * If so, then don't put the dentry on the lru list,
1777 * kill it immediately.
1778 */
1779 return proc_inode_is_dead(d_inode(dentry));
1780 }
1781
1782 const struct dentry_operations pid_dentry_operations =
1783 {
1784 .d_revalidate = pid_revalidate,
1785 .d_delete = pid_delete_dentry,
1786 };
1787
1788 /* Lookups */
1789
1790 /*
1791 * Fill a directory entry.
1792 *
1793 * If possible create the dcache entry and derive our inode number and
1794 * file type from dcache entry.
1795 *
1796 * Since all of the proc inode numbers are dynamically generated, the inode
1797 * numbers do not exist until the inode is cache. This means creating the
1798 * the dcache entry in readdir is necessary to keep the inode numbers
1799 * reported by readdir in sync with the inode numbers reported
1800 * by stat.
1801 */
1802 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1803 const char *name, int len,
1804 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1805 {
1806 struct dentry *child, *dir = file->f_path.dentry;
1807 struct qstr qname = QSTR_INIT(name, len);
1808 struct inode *inode;
1809 unsigned type;
1810 ino_t ino;
1811
1812 child = d_hash_and_lookup(dir, &qname);
1813 if (!child) {
1814 child = d_alloc(dir, &qname);
1815 if (!child)
1816 goto end_instantiate;
1817 if (instantiate(d_inode(dir), child, task, ptr) < 0) {
1818 dput(child);
1819 goto end_instantiate;
1820 }
1821 }
1822 inode = d_inode(child);
1823 ino = inode->i_ino;
1824 type = inode->i_mode >> 12;
1825 dput(child);
1826 return dir_emit(ctx, name, len, ino, type);
1827
1828 end_instantiate:
1829 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1830 }
1831
1832 /*
1833 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1834 * which represent vma start and end addresses.
1835 */
1836 static int dname_to_vma_addr(struct dentry *dentry,
1837 unsigned long *start, unsigned long *end)
1838 {
1839 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1840 return -EINVAL;
1841
1842 return 0;
1843 }
1844
1845 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1846 {
1847 unsigned long vm_start, vm_end;
1848 bool exact_vma_exists = false;
1849 struct mm_struct *mm = NULL;
1850 struct task_struct *task;
1851 const struct cred *cred;
1852 struct inode *inode;
1853 int status = 0;
1854
1855 if (flags & LOOKUP_RCU)
1856 return -ECHILD;
1857
1858 inode = d_inode(dentry);
1859 task = get_proc_task(inode);
1860 if (!task)
1861 goto out_notask;
1862
1863 mm = mm_access(task, PTRACE_MODE_READ);
1864 if (IS_ERR_OR_NULL(mm))
1865 goto out;
1866
1867 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1868 down_read(&mm->mmap_sem);
1869 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1870 up_read(&mm->mmap_sem);
1871 }
1872
1873 mmput(mm);
1874
1875 if (exact_vma_exists) {
1876 if (task_dumpable(task)) {
1877 rcu_read_lock();
1878 cred = __task_cred(task);
1879 inode->i_uid = cred->euid;
1880 inode->i_gid = cred->egid;
1881 rcu_read_unlock();
1882 } else {
1883 inode->i_uid = GLOBAL_ROOT_UID;
1884 inode->i_gid = GLOBAL_ROOT_GID;
1885 }
1886 security_task_to_inode(task, inode);
1887 status = 1;
1888 }
1889
1890 out:
1891 put_task_struct(task);
1892
1893 out_notask:
1894 return status;
1895 }
1896
1897 static const struct dentry_operations tid_map_files_dentry_operations = {
1898 .d_revalidate = map_files_d_revalidate,
1899 .d_delete = pid_delete_dentry,
1900 };
1901
1902 static int map_files_get_link(struct dentry *dentry, struct path *path)
1903 {
1904 unsigned long vm_start, vm_end;
1905 struct vm_area_struct *vma;
1906 struct task_struct *task;
1907 struct mm_struct *mm;
1908 int rc;
1909
1910 rc = -ENOENT;
1911 task = get_proc_task(d_inode(dentry));
1912 if (!task)
1913 goto out;
1914
1915 mm = get_task_mm(task);
1916 put_task_struct(task);
1917 if (!mm)
1918 goto out;
1919
1920 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1921 if (rc)
1922 goto out_mmput;
1923
1924 rc = -ENOENT;
1925 down_read(&mm->mmap_sem);
1926 vma = find_exact_vma(mm, vm_start, vm_end);
1927 if (vma && vma->vm_file) {
1928 *path = vma->vm_file->f_path;
1929 path_get(path);
1930 rc = 0;
1931 }
1932 up_read(&mm->mmap_sem);
1933
1934 out_mmput:
1935 mmput(mm);
1936 out:
1937 return rc;
1938 }
1939
1940 struct map_files_info {
1941 fmode_t mode;
1942 unsigned long len;
1943 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1944 };
1945
1946 /*
1947 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1948 * symlinks may be used to bypass permissions on ancestor directories in the
1949 * path to the file in question.
1950 */
1951 static const char *
1952 proc_map_files_get_link(struct dentry *dentry,
1953 struct inode *inode,
1954 struct delayed_call *done)
1955 {
1956 if (!capable(CAP_SYS_ADMIN))
1957 return ERR_PTR(-EPERM);
1958
1959 return proc_pid_get_link(dentry, inode, done);
1960 }
1961
1962 /*
1963 * Identical to proc_pid_link_inode_operations except for get_link()
1964 */
1965 static const struct inode_operations proc_map_files_link_inode_operations = {
1966 .readlink = proc_pid_readlink,
1967 .get_link = proc_map_files_get_link,
1968 .setattr = proc_setattr,
1969 };
1970
1971 static int
1972 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1973 struct task_struct *task, const void *ptr)
1974 {
1975 fmode_t mode = (fmode_t)(unsigned long)ptr;
1976 struct proc_inode *ei;
1977 struct inode *inode;
1978
1979 inode = proc_pid_make_inode(dir->i_sb, task);
1980 if (!inode)
1981 return -ENOENT;
1982
1983 ei = PROC_I(inode);
1984 ei->op.proc_get_link = map_files_get_link;
1985
1986 inode->i_op = &proc_map_files_link_inode_operations;
1987 inode->i_size = 64;
1988 inode->i_mode = S_IFLNK;
1989
1990 if (mode & FMODE_READ)
1991 inode->i_mode |= S_IRUSR;
1992 if (mode & FMODE_WRITE)
1993 inode->i_mode |= S_IWUSR;
1994
1995 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1996 d_add(dentry, inode);
1997
1998 return 0;
1999 }
2000
2001 static struct dentry *proc_map_files_lookup(struct inode *dir,
2002 struct dentry *dentry, unsigned int flags)
2003 {
2004 unsigned long vm_start, vm_end;
2005 struct vm_area_struct *vma;
2006 struct task_struct *task;
2007 int result;
2008 struct mm_struct *mm;
2009
2010 result = -ENOENT;
2011 task = get_proc_task(dir);
2012 if (!task)
2013 goto out;
2014
2015 result = -EACCES;
2016 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2017 goto out_put_task;
2018
2019 result = -ENOENT;
2020 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2021 goto out_put_task;
2022
2023 mm = get_task_mm(task);
2024 if (!mm)
2025 goto out_put_task;
2026
2027 down_read(&mm->mmap_sem);
2028 vma = find_exact_vma(mm, vm_start, vm_end);
2029 if (!vma)
2030 goto out_no_vma;
2031
2032 if (vma->vm_file)
2033 result = proc_map_files_instantiate(dir, dentry, task,
2034 (void *)(unsigned long)vma->vm_file->f_mode);
2035
2036 out_no_vma:
2037 up_read(&mm->mmap_sem);
2038 mmput(mm);
2039 out_put_task:
2040 put_task_struct(task);
2041 out:
2042 return ERR_PTR(result);
2043 }
2044
2045 static const struct inode_operations proc_map_files_inode_operations = {
2046 .lookup = proc_map_files_lookup,
2047 .permission = proc_fd_permission,
2048 .setattr = proc_setattr,
2049 };
2050
2051 static int
2052 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2053 {
2054 struct vm_area_struct *vma;
2055 struct task_struct *task;
2056 struct mm_struct *mm;
2057 unsigned long nr_files, pos, i;
2058 struct flex_array *fa = NULL;
2059 struct map_files_info info;
2060 struct map_files_info *p;
2061 int ret;
2062
2063 ret = -ENOENT;
2064 task = get_proc_task(file_inode(file));
2065 if (!task)
2066 goto out;
2067
2068 ret = -EACCES;
2069 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2070 goto out_put_task;
2071
2072 ret = 0;
2073 if (!dir_emit_dots(file, ctx))
2074 goto out_put_task;
2075
2076 mm = get_task_mm(task);
2077 if (!mm)
2078 goto out_put_task;
2079 down_read(&mm->mmap_sem);
2080
2081 nr_files = 0;
2082
2083 /*
2084 * We need two passes here:
2085 *
2086 * 1) Collect vmas of mapped files with mmap_sem taken
2087 * 2) Release mmap_sem and instantiate entries
2088 *
2089 * otherwise we get lockdep complained, since filldir()
2090 * routine might require mmap_sem taken in might_fault().
2091 */
2092
2093 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2094 if (vma->vm_file && ++pos > ctx->pos)
2095 nr_files++;
2096 }
2097
2098 if (nr_files) {
2099 fa = flex_array_alloc(sizeof(info), nr_files,
2100 GFP_KERNEL);
2101 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2102 GFP_KERNEL)) {
2103 ret = -ENOMEM;
2104 if (fa)
2105 flex_array_free(fa);
2106 up_read(&mm->mmap_sem);
2107 mmput(mm);
2108 goto out_put_task;
2109 }
2110 for (i = 0, vma = mm->mmap, pos = 2; vma;
2111 vma = vma->vm_next) {
2112 if (!vma->vm_file)
2113 continue;
2114 if (++pos <= ctx->pos)
2115 continue;
2116
2117 info.mode = vma->vm_file->f_mode;
2118 info.len = snprintf(info.name,
2119 sizeof(info.name), "%lx-%lx",
2120 vma->vm_start, vma->vm_end);
2121 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2122 BUG();
2123 }
2124 }
2125 up_read(&mm->mmap_sem);
2126
2127 for (i = 0; i < nr_files; i++) {
2128 p = flex_array_get(fa, i);
2129 if (!proc_fill_cache(file, ctx,
2130 p->name, p->len,
2131 proc_map_files_instantiate,
2132 task,
2133 (void *)(unsigned long)p->mode))
2134 break;
2135 ctx->pos++;
2136 }
2137 if (fa)
2138 flex_array_free(fa);
2139 mmput(mm);
2140
2141 out_put_task:
2142 put_task_struct(task);
2143 out:
2144 return ret;
2145 }
2146
2147 static const struct file_operations proc_map_files_operations = {
2148 .read = generic_read_dir,
2149 .iterate = proc_map_files_readdir,
2150 .llseek = default_llseek,
2151 };
2152
2153 struct timers_private {
2154 struct pid *pid;
2155 struct task_struct *task;
2156 struct sighand_struct *sighand;
2157 struct pid_namespace *ns;
2158 unsigned long flags;
2159 };
2160
2161 static void *timers_start(struct seq_file *m, loff_t *pos)
2162 {
2163 struct timers_private *tp = m->private;
2164
2165 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2166 if (!tp->task)
2167 return ERR_PTR(-ESRCH);
2168
2169 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2170 if (!tp->sighand)
2171 return ERR_PTR(-ESRCH);
2172
2173 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2174 }
2175
2176 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2177 {
2178 struct timers_private *tp = m->private;
2179 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2180 }
2181
2182 static void timers_stop(struct seq_file *m, void *v)
2183 {
2184 struct timers_private *tp = m->private;
2185
2186 if (tp->sighand) {
2187 unlock_task_sighand(tp->task, &tp->flags);
2188 tp->sighand = NULL;
2189 }
2190
2191 if (tp->task) {
2192 put_task_struct(tp->task);
2193 tp->task = NULL;
2194 }
2195 }
2196
2197 static int show_timer(struct seq_file *m, void *v)
2198 {
2199 struct k_itimer *timer;
2200 struct timers_private *tp = m->private;
2201 int notify;
2202 static const char * const nstr[] = {
2203 [SIGEV_SIGNAL] = "signal",
2204 [SIGEV_NONE] = "none",
2205 [SIGEV_THREAD] = "thread",
2206 };
2207
2208 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2209 notify = timer->it_sigev_notify;
2210
2211 seq_printf(m, "ID: %d\n", timer->it_id);
2212 seq_printf(m, "signal: %d/%p\n",
2213 timer->sigq->info.si_signo,
2214 timer->sigq->info.si_value.sival_ptr);
2215 seq_printf(m, "notify: %s/%s.%d\n",
2216 nstr[notify & ~SIGEV_THREAD_ID],
2217 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2218 pid_nr_ns(timer->it_pid, tp->ns));
2219 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2220
2221 return 0;
2222 }
2223
2224 static const struct seq_operations proc_timers_seq_ops = {
2225 .start = timers_start,
2226 .next = timers_next,
2227 .stop = timers_stop,
2228 .show = show_timer,
2229 };
2230
2231 static int proc_timers_open(struct inode *inode, struct file *file)
2232 {
2233 struct timers_private *tp;
2234
2235 tp = __seq_open_private(file, &proc_timers_seq_ops,
2236 sizeof(struct timers_private));
2237 if (!tp)
2238 return -ENOMEM;
2239
2240 tp->pid = proc_pid(inode);
2241 tp->ns = inode->i_sb->s_fs_info;
2242 return 0;
2243 }
2244
2245 static const struct file_operations proc_timers_operations = {
2246 .open = proc_timers_open,
2247 .read = seq_read,
2248 .llseek = seq_lseek,
2249 .release = seq_release_private,
2250 };
2251
2252 static int proc_pident_instantiate(struct inode *dir,
2253 struct dentry *dentry, struct task_struct *task, const void *ptr)
2254 {
2255 const struct pid_entry *p = ptr;
2256 struct inode *inode;
2257 struct proc_inode *ei;
2258
2259 inode = proc_pid_make_inode(dir->i_sb, task);
2260 if (!inode)
2261 goto out;
2262
2263 ei = PROC_I(inode);
2264 inode->i_mode = p->mode;
2265 if (S_ISDIR(inode->i_mode))
2266 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2267 if (p->iop)
2268 inode->i_op = p->iop;
2269 if (p->fop)
2270 inode->i_fop = p->fop;
2271 ei->op = p->op;
2272 d_set_d_op(dentry, &pid_dentry_operations);
2273 d_add(dentry, inode);
2274 /* Close the race of the process dying before we return the dentry */
2275 if (pid_revalidate(dentry, 0))
2276 return 0;
2277 out:
2278 return -ENOENT;
2279 }
2280
2281 static struct dentry *proc_pident_lookup(struct inode *dir,
2282 struct dentry *dentry,
2283 const struct pid_entry *ents,
2284 unsigned int nents)
2285 {
2286 int error;
2287 struct task_struct *task = get_proc_task(dir);
2288 const struct pid_entry *p, *last;
2289
2290 error = -ENOENT;
2291
2292 if (!task)
2293 goto out_no_task;
2294
2295 /*
2296 * Yes, it does not scale. And it should not. Don't add
2297 * new entries into /proc/<tgid>/ without very good reasons.
2298 */
2299 last = &ents[nents - 1];
2300 for (p = ents; p <= last; p++) {
2301 if (p->len != dentry->d_name.len)
2302 continue;
2303 if (!memcmp(dentry->d_name.name, p->name, p->len))
2304 break;
2305 }
2306 if (p > last)
2307 goto out;
2308
2309 error = proc_pident_instantiate(dir, dentry, task, p);
2310 out:
2311 put_task_struct(task);
2312 out_no_task:
2313 return ERR_PTR(error);
2314 }
2315
2316 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2317 const struct pid_entry *ents, unsigned int nents)
2318 {
2319 struct task_struct *task = get_proc_task(file_inode(file));
2320 const struct pid_entry *p;
2321
2322 if (!task)
2323 return -ENOENT;
2324
2325 if (!dir_emit_dots(file, ctx))
2326 goto out;
2327
2328 if (ctx->pos >= nents + 2)
2329 goto out;
2330
2331 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2332 if (!proc_fill_cache(file, ctx, p->name, p->len,
2333 proc_pident_instantiate, task, p))
2334 break;
2335 ctx->pos++;
2336 }
2337 out:
2338 put_task_struct(task);
2339 return 0;
2340 }
2341
2342 #ifdef CONFIG_SECURITY
2343 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2344 size_t count, loff_t *ppos)
2345 {
2346 struct inode * inode = file_inode(file);
2347 char *p = NULL;
2348 ssize_t length;
2349 struct task_struct *task = get_proc_task(inode);
2350
2351 if (!task)
2352 return -ESRCH;
2353
2354 length = security_getprocattr(task,
2355 (char*)file->f_path.dentry->d_name.name,
2356 &p);
2357 put_task_struct(task);
2358 if (length > 0)
2359 length = simple_read_from_buffer(buf, count, ppos, p, length);
2360 kfree(p);
2361 return length;
2362 }
2363
2364 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2365 size_t count, loff_t *ppos)
2366 {
2367 struct inode * inode = file_inode(file);
2368 char *page;
2369 ssize_t length;
2370 struct task_struct *task = get_proc_task(inode);
2371
2372 length = -ESRCH;
2373 if (!task)
2374 goto out_no_task;
2375 if (count > PAGE_SIZE)
2376 count = PAGE_SIZE;
2377
2378 /* No partial writes. */
2379 length = -EINVAL;
2380 if (*ppos != 0)
2381 goto out;
2382
2383 length = -ENOMEM;
2384 page = (char*)__get_free_page(GFP_TEMPORARY);
2385 if (!page)
2386 goto out;
2387
2388 length = -EFAULT;
2389 if (copy_from_user(page, buf, count))
2390 goto out_free;
2391
2392 /* Guard against adverse ptrace interaction */
2393 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2394 if (length < 0)
2395 goto out_free;
2396
2397 length = security_setprocattr(task,
2398 (char*)file->f_path.dentry->d_name.name,
2399 (void*)page, count);
2400 mutex_unlock(&task->signal->cred_guard_mutex);
2401 out_free:
2402 free_page((unsigned long) page);
2403 out:
2404 put_task_struct(task);
2405 out_no_task:
2406 return length;
2407 }
2408
2409 static const struct file_operations proc_pid_attr_operations = {
2410 .read = proc_pid_attr_read,
2411 .write = proc_pid_attr_write,
2412 .llseek = generic_file_llseek,
2413 };
2414
2415 static const struct pid_entry attr_dir_stuff[] = {
2416 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2417 REG("prev", S_IRUGO, proc_pid_attr_operations),
2418 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2419 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2420 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2421 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2422 };
2423
2424 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2425 {
2426 return proc_pident_readdir(file, ctx,
2427 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2428 }
2429
2430 static const struct file_operations proc_attr_dir_operations = {
2431 .read = generic_read_dir,
2432 .iterate = proc_attr_dir_readdir,
2433 .llseek = default_llseek,
2434 };
2435
2436 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2437 struct dentry *dentry, unsigned int flags)
2438 {
2439 return proc_pident_lookup(dir, dentry,
2440 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2441 }
2442
2443 static const struct inode_operations proc_attr_dir_inode_operations = {
2444 .lookup = proc_attr_dir_lookup,
2445 .getattr = pid_getattr,
2446 .setattr = proc_setattr,
2447 };
2448
2449 #endif
2450
2451 #ifdef CONFIG_ELF_CORE
2452 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2453 size_t count, loff_t *ppos)
2454 {
2455 struct task_struct *task = get_proc_task(file_inode(file));
2456 struct mm_struct *mm;
2457 char buffer[PROC_NUMBUF];
2458 size_t len;
2459 int ret;
2460
2461 if (!task)
2462 return -ESRCH;
2463
2464 ret = 0;
2465 mm = get_task_mm(task);
2466 if (mm) {
2467 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2468 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2469 MMF_DUMP_FILTER_SHIFT));
2470 mmput(mm);
2471 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2472 }
2473
2474 put_task_struct(task);
2475
2476 return ret;
2477 }
2478
2479 static ssize_t proc_coredump_filter_write(struct file *file,
2480 const char __user *buf,
2481 size_t count,
2482 loff_t *ppos)
2483 {
2484 struct task_struct *task;
2485 struct mm_struct *mm;
2486 unsigned int val;
2487 int ret;
2488 int i;
2489 unsigned long mask;
2490
2491 ret = kstrtouint_from_user(buf, count, 0, &val);
2492 if (ret < 0)
2493 return ret;
2494
2495 ret = -ESRCH;
2496 task = get_proc_task(file_inode(file));
2497 if (!task)
2498 goto out_no_task;
2499
2500 mm = get_task_mm(task);
2501 if (!mm)
2502 goto out_no_mm;
2503 ret = 0;
2504
2505 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2506 if (val & mask)
2507 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2508 else
2509 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2510 }
2511
2512 mmput(mm);
2513 out_no_mm:
2514 put_task_struct(task);
2515 out_no_task:
2516 if (ret < 0)
2517 return ret;
2518 return count;
2519 }
2520
2521 static const struct file_operations proc_coredump_filter_operations = {
2522 .read = proc_coredump_filter_read,
2523 .write = proc_coredump_filter_write,
2524 .llseek = generic_file_llseek,
2525 };
2526 #endif
2527
2528 #ifdef CONFIG_TASK_IO_ACCOUNTING
2529 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2530 {
2531 struct task_io_accounting acct = task->ioac;
2532 unsigned long flags;
2533 int result;
2534
2535 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2536 if (result)
2537 return result;
2538
2539 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2540 result = -EACCES;
2541 goto out_unlock;
2542 }
2543
2544 if (whole && lock_task_sighand(task, &flags)) {
2545 struct task_struct *t = task;
2546
2547 task_io_accounting_add(&acct, &task->signal->ioac);
2548 while_each_thread(task, t)
2549 task_io_accounting_add(&acct, &t->ioac);
2550
2551 unlock_task_sighand(task, &flags);
2552 }
2553 seq_printf(m,
2554 "rchar: %llu\n"
2555 "wchar: %llu\n"
2556 "syscr: %llu\n"
2557 "syscw: %llu\n"
2558 "read_bytes: %llu\n"
2559 "write_bytes: %llu\n"
2560 "cancelled_write_bytes: %llu\n",
2561 (unsigned long long)acct.rchar,
2562 (unsigned long long)acct.wchar,
2563 (unsigned long long)acct.syscr,
2564 (unsigned long long)acct.syscw,
2565 (unsigned long long)acct.read_bytes,
2566 (unsigned long long)acct.write_bytes,
2567 (unsigned long long)acct.cancelled_write_bytes);
2568 result = 0;
2569
2570 out_unlock:
2571 mutex_unlock(&task->signal->cred_guard_mutex);
2572 return result;
2573 }
2574
2575 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2576 struct pid *pid, struct task_struct *task)
2577 {
2578 return do_io_accounting(task, m, 0);
2579 }
2580
2581 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2582 struct pid *pid, struct task_struct *task)
2583 {
2584 return do_io_accounting(task, m, 1);
2585 }
2586 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2587
2588 #ifdef CONFIG_USER_NS
2589 static int proc_id_map_open(struct inode *inode, struct file *file,
2590 const struct seq_operations *seq_ops)
2591 {
2592 struct user_namespace *ns = NULL;
2593 struct task_struct *task;
2594 struct seq_file *seq;
2595 int ret = -EINVAL;
2596
2597 task = get_proc_task(inode);
2598 if (task) {
2599 rcu_read_lock();
2600 ns = get_user_ns(task_cred_xxx(task, user_ns));
2601 rcu_read_unlock();
2602 put_task_struct(task);
2603 }
2604 if (!ns)
2605 goto err;
2606
2607 ret = seq_open(file, seq_ops);
2608 if (ret)
2609 goto err_put_ns;
2610
2611 seq = file->private_data;
2612 seq->private = ns;
2613
2614 return 0;
2615 err_put_ns:
2616 put_user_ns(ns);
2617 err:
2618 return ret;
2619 }
2620
2621 static int proc_id_map_release(struct inode *inode, struct file *file)
2622 {
2623 struct seq_file *seq = file->private_data;
2624 struct user_namespace *ns = seq->private;
2625 put_user_ns(ns);
2626 return seq_release(inode, file);
2627 }
2628
2629 static int proc_uid_map_open(struct inode *inode, struct file *file)
2630 {
2631 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2632 }
2633
2634 static int proc_gid_map_open(struct inode *inode, struct file *file)
2635 {
2636 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2637 }
2638
2639 static int proc_projid_map_open(struct inode *inode, struct file *file)
2640 {
2641 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2642 }
2643
2644 static const struct file_operations proc_uid_map_operations = {
2645 .open = proc_uid_map_open,
2646 .write = proc_uid_map_write,
2647 .read = seq_read,
2648 .llseek = seq_lseek,
2649 .release = proc_id_map_release,
2650 };
2651
2652 static const struct file_operations proc_gid_map_operations = {
2653 .open = proc_gid_map_open,
2654 .write = proc_gid_map_write,
2655 .read = seq_read,
2656 .llseek = seq_lseek,
2657 .release = proc_id_map_release,
2658 };
2659
2660 static const struct file_operations proc_projid_map_operations = {
2661 .open = proc_projid_map_open,
2662 .write = proc_projid_map_write,
2663 .read = seq_read,
2664 .llseek = seq_lseek,
2665 .release = proc_id_map_release,
2666 };
2667
2668 static int proc_setgroups_open(struct inode *inode, struct file *file)
2669 {
2670 struct user_namespace *ns = NULL;
2671 struct task_struct *task;
2672 int ret;
2673
2674 ret = -ESRCH;
2675 task = get_proc_task(inode);
2676 if (task) {
2677 rcu_read_lock();
2678 ns = get_user_ns(task_cred_xxx(task, user_ns));
2679 rcu_read_unlock();
2680 put_task_struct(task);
2681 }
2682 if (!ns)
2683 goto err;
2684
2685 if (file->f_mode & FMODE_WRITE) {
2686 ret = -EACCES;
2687 if (!ns_capable(ns, CAP_SYS_ADMIN))
2688 goto err_put_ns;
2689 }
2690
2691 ret = single_open(file, &proc_setgroups_show, ns);
2692 if (ret)
2693 goto err_put_ns;
2694
2695 return 0;
2696 err_put_ns:
2697 put_user_ns(ns);
2698 err:
2699 return ret;
2700 }
2701
2702 static int proc_setgroups_release(struct inode *inode, struct file *file)
2703 {
2704 struct seq_file *seq = file->private_data;
2705 struct user_namespace *ns = seq->private;
2706 int ret = single_release(inode, file);
2707 put_user_ns(ns);
2708 return ret;
2709 }
2710
2711 static const struct file_operations proc_setgroups_operations = {
2712 .open = proc_setgroups_open,
2713 .write = proc_setgroups_write,
2714 .read = seq_read,
2715 .llseek = seq_lseek,
2716 .release = proc_setgroups_release,
2717 };
2718 #endif /* CONFIG_USER_NS */
2719
2720 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2721 struct pid *pid, struct task_struct *task)
2722 {
2723 int err = lock_trace(task);
2724 if (!err) {
2725 seq_printf(m, "%08x\n", task->personality);
2726 unlock_trace(task);
2727 }
2728 return err;
2729 }
2730
2731 /*
2732 * Thread groups
2733 */
2734 static const struct file_operations proc_task_operations;
2735 static const struct inode_operations proc_task_inode_operations;
2736
2737 static const struct pid_entry tgid_base_stuff[] = {
2738 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2739 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2740 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2741 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2742 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2743 #ifdef CONFIG_NET
2744 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2745 #endif
2746 REG("environ", S_IRUSR, proc_environ_operations),
2747 ONE("auxv", S_IRUSR, proc_pid_auxv),
2748 ONE("status", S_IRUGO, proc_pid_status),
2749 ONE("personality", S_IRUSR, proc_pid_personality),
2750 ONE("limits", S_IRUGO, proc_pid_limits),
2751 #ifdef CONFIG_SCHED_DEBUG
2752 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2753 #endif
2754 #ifdef CONFIG_SCHED_AUTOGROUP
2755 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2756 #endif
2757 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2758 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2759 ONE("syscall", S_IRUSR, proc_pid_syscall),
2760 #endif
2761 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2762 ONE("stat", S_IRUGO, proc_tgid_stat),
2763 ONE("statm", S_IRUGO, proc_pid_statm),
2764 REG("maps", S_IRUGO, proc_pid_maps_operations),
2765 #ifdef CONFIG_NUMA
2766 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2767 #endif
2768 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2769 LNK("cwd", proc_cwd_link),
2770 LNK("root", proc_root_link),
2771 LNK("exe", proc_exe_link),
2772 REG("mounts", S_IRUGO, proc_mounts_operations),
2773 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2774 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2775 #ifdef CONFIG_PROC_PAGE_MONITOR
2776 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2777 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2778 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2779 #endif
2780 #ifdef CONFIG_SECURITY
2781 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2782 #endif
2783 #ifdef CONFIG_KALLSYMS
2784 ONE("wchan", S_IRUGO, proc_pid_wchan),
2785 #endif
2786 #ifdef CONFIG_STACKTRACE
2787 ONE("stack", S_IRUSR, proc_pid_stack),
2788 #endif
2789 #ifdef CONFIG_SCHED_INFO
2790 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2791 #endif
2792 #ifdef CONFIG_LATENCYTOP
2793 REG("latency", S_IRUGO, proc_lstats_operations),
2794 #endif
2795 #ifdef CONFIG_PROC_PID_CPUSET
2796 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2797 #endif
2798 #ifdef CONFIG_CGROUPS
2799 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2800 #endif
2801 ONE("oom_score", S_IRUGO, proc_oom_score),
2802 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2803 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2804 #ifdef CONFIG_AUDITSYSCALL
2805 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2806 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2807 #endif
2808 #ifdef CONFIG_FAULT_INJECTION
2809 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2810 #endif
2811 #ifdef CONFIG_ELF_CORE
2812 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2813 #endif
2814 #ifdef CONFIG_TASK_IO_ACCOUNTING
2815 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2816 #endif
2817 #ifdef CONFIG_HARDWALL
2818 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2819 #endif
2820 #ifdef CONFIG_USER_NS
2821 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2822 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2823 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2824 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2825 #endif
2826 #ifdef CONFIG_CHECKPOINT_RESTORE
2827 REG("timers", S_IRUGO, proc_timers_operations),
2828 #endif
2829 };
2830
2831 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2832 {
2833 return proc_pident_readdir(file, ctx,
2834 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2835 }
2836
2837 static const struct file_operations proc_tgid_base_operations = {
2838 .read = generic_read_dir,
2839 .iterate = proc_tgid_base_readdir,
2840 .llseek = default_llseek,
2841 };
2842
2843 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2844 {
2845 return proc_pident_lookup(dir, dentry,
2846 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2847 }
2848
2849 static const struct inode_operations proc_tgid_base_inode_operations = {
2850 .lookup = proc_tgid_base_lookup,
2851 .getattr = pid_getattr,
2852 .setattr = proc_setattr,
2853 .permission = proc_pid_permission,
2854 };
2855
2856 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2857 {
2858 struct dentry *dentry, *leader, *dir;
2859 char buf[PROC_NUMBUF];
2860 struct qstr name;
2861
2862 name.name = buf;
2863 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2864 /* no ->d_hash() rejects on procfs */
2865 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2866 if (dentry) {
2867 d_invalidate(dentry);
2868 dput(dentry);
2869 }
2870
2871 if (pid == tgid)
2872 return;
2873
2874 name.name = buf;
2875 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2876 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2877 if (!leader)
2878 goto out;
2879
2880 name.name = "task";
2881 name.len = strlen(name.name);
2882 dir = d_hash_and_lookup(leader, &name);
2883 if (!dir)
2884 goto out_put_leader;
2885
2886 name.name = buf;
2887 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2888 dentry = d_hash_and_lookup(dir, &name);
2889 if (dentry) {
2890 d_invalidate(dentry);
2891 dput(dentry);
2892 }
2893
2894 dput(dir);
2895 out_put_leader:
2896 dput(leader);
2897 out:
2898 return;
2899 }
2900
2901 /**
2902 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2903 * @task: task that should be flushed.
2904 *
2905 * When flushing dentries from proc, one needs to flush them from global
2906 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2907 * in. This call is supposed to do all of this job.
2908 *
2909 * Looks in the dcache for
2910 * /proc/@pid
2911 * /proc/@tgid/task/@pid
2912 * if either directory is present flushes it and all of it'ts children
2913 * from the dcache.
2914 *
2915 * It is safe and reasonable to cache /proc entries for a task until
2916 * that task exits. After that they just clog up the dcache with
2917 * useless entries, possibly causing useful dcache entries to be
2918 * flushed instead. This routine is proved to flush those useless
2919 * dcache entries at process exit time.
2920 *
2921 * NOTE: This routine is just an optimization so it does not guarantee
2922 * that no dcache entries will exist at process exit time it
2923 * just makes it very unlikely that any will persist.
2924 */
2925
2926 void proc_flush_task(struct task_struct *task)
2927 {
2928 int i;
2929 struct pid *pid, *tgid;
2930 struct upid *upid;
2931
2932 pid = task_pid(task);
2933 tgid = task_tgid(task);
2934
2935 for (i = 0; i <= pid->level; i++) {
2936 upid = &pid->numbers[i];
2937 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2938 tgid->numbers[i].nr);
2939 }
2940 }
2941
2942 static int proc_pid_instantiate(struct inode *dir,
2943 struct dentry * dentry,
2944 struct task_struct *task, const void *ptr)
2945 {
2946 struct inode *inode;
2947
2948 inode = proc_pid_make_inode(dir->i_sb, task);
2949 if (!inode)
2950 goto out;
2951
2952 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2953 inode->i_op = &proc_tgid_base_inode_operations;
2954 inode->i_fop = &proc_tgid_base_operations;
2955 inode->i_flags|=S_IMMUTABLE;
2956
2957 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2958 ARRAY_SIZE(tgid_base_stuff)));
2959
2960 d_set_d_op(dentry, &pid_dentry_operations);
2961
2962 d_add(dentry, inode);
2963 /* Close the race of the process dying before we return the dentry */
2964 if (pid_revalidate(dentry, 0))
2965 return 0;
2966 out:
2967 return -ENOENT;
2968 }
2969
2970 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2971 {
2972 int result = -ENOENT;
2973 struct task_struct *task;
2974 unsigned tgid;
2975 struct pid_namespace *ns;
2976
2977 tgid = name_to_int(&dentry->d_name);
2978 if (tgid == ~0U)
2979 goto out;
2980
2981 ns = dentry->d_sb->s_fs_info;
2982 rcu_read_lock();
2983 task = find_task_by_pid_ns(tgid, ns);
2984 if (task)
2985 get_task_struct(task);
2986 rcu_read_unlock();
2987 if (!task)
2988 goto out;
2989
2990 result = proc_pid_instantiate(dir, dentry, task, NULL);
2991 put_task_struct(task);
2992 out:
2993 return ERR_PTR(result);
2994 }
2995
2996 /*
2997 * Find the first task with tgid >= tgid
2998 *
2999 */
3000 struct tgid_iter {
3001 unsigned int tgid;
3002 struct task_struct *task;
3003 };
3004 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3005 {
3006 struct pid *pid;
3007
3008 if (iter.task)
3009 put_task_struct(iter.task);
3010 rcu_read_lock();
3011 retry:
3012 iter.task = NULL;
3013 pid = find_ge_pid(iter.tgid, ns);
3014 if (pid) {
3015 iter.tgid = pid_nr_ns(pid, ns);
3016 iter.task = pid_task(pid, PIDTYPE_PID);
3017 /* What we to know is if the pid we have find is the
3018 * pid of a thread_group_leader. Testing for task
3019 * being a thread_group_leader is the obvious thing
3020 * todo but there is a window when it fails, due to
3021 * the pid transfer logic in de_thread.
3022 *
3023 * So we perform the straight forward test of seeing
3024 * if the pid we have found is the pid of a thread
3025 * group leader, and don't worry if the task we have
3026 * found doesn't happen to be a thread group leader.
3027 * As we don't care in the case of readdir.
3028 */
3029 if (!iter.task || !has_group_leader_pid(iter.task)) {
3030 iter.tgid += 1;
3031 goto retry;
3032 }
3033 get_task_struct(iter.task);
3034 }
3035 rcu_read_unlock();
3036 return iter;
3037 }
3038
3039 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3040
3041 /* for the /proc/ directory itself, after non-process stuff has been done */
3042 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3043 {
3044 struct tgid_iter iter;
3045 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3046 loff_t pos = ctx->pos;
3047
3048 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3049 return 0;
3050
3051 if (pos == TGID_OFFSET - 2) {
3052 struct inode *inode = d_inode(ns->proc_self);
3053 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3054 return 0;
3055 ctx->pos = pos = pos + 1;
3056 }
3057 if (pos == TGID_OFFSET - 1) {
3058 struct inode *inode = d_inode(ns->proc_thread_self);
3059 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3060 return 0;
3061 ctx->pos = pos = pos + 1;
3062 }
3063 iter.tgid = pos - TGID_OFFSET;
3064 iter.task = NULL;
3065 for (iter = next_tgid(ns, iter);
3066 iter.task;
3067 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3068 char name[PROC_NUMBUF];
3069 int len;
3070 if (!has_pid_permissions(ns, iter.task, 2))
3071 continue;
3072
3073 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3074 ctx->pos = iter.tgid + TGID_OFFSET;
3075 if (!proc_fill_cache(file, ctx, name, len,
3076 proc_pid_instantiate, iter.task, NULL)) {
3077 put_task_struct(iter.task);
3078 return 0;
3079 }
3080 }
3081 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3082 return 0;
3083 }
3084
3085 /*
3086 * Tasks
3087 */
3088 static const struct pid_entry tid_base_stuff[] = {
3089 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3090 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3091 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3092 #ifdef CONFIG_NET
3093 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3094 #endif
3095 REG("environ", S_IRUSR, proc_environ_operations),
3096 ONE("auxv", S_IRUSR, proc_pid_auxv),
3097 ONE("status", S_IRUGO, proc_pid_status),
3098 ONE("personality", S_IRUSR, proc_pid_personality),
3099 ONE("limits", S_IRUGO, proc_pid_limits),
3100 #ifdef CONFIG_SCHED_DEBUG
3101 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3102 #endif
3103 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3104 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3105 ONE("syscall", S_IRUSR, proc_pid_syscall),
3106 #endif
3107 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3108 ONE("stat", S_IRUGO, proc_tid_stat),
3109 ONE("statm", S_IRUGO, proc_pid_statm),
3110 REG("maps", S_IRUGO, proc_tid_maps_operations),
3111 #ifdef CONFIG_PROC_CHILDREN
3112 REG("children", S_IRUGO, proc_tid_children_operations),
3113 #endif
3114 #ifdef CONFIG_NUMA
3115 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3116 #endif
3117 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3118 LNK("cwd", proc_cwd_link),
3119 LNK("root", proc_root_link),
3120 LNK("exe", proc_exe_link),
3121 REG("mounts", S_IRUGO, proc_mounts_operations),
3122 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3123 #ifdef CONFIG_PROC_PAGE_MONITOR
3124 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3125 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3126 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3127 #endif
3128 #ifdef CONFIG_SECURITY
3129 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3130 #endif
3131 #ifdef CONFIG_KALLSYMS
3132 ONE("wchan", S_IRUGO, proc_pid_wchan),
3133 #endif
3134 #ifdef CONFIG_STACKTRACE
3135 ONE("stack", S_IRUSR, proc_pid_stack),
3136 #endif
3137 #ifdef CONFIG_SCHED_INFO
3138 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3139 #endif
3140 #ifdef CONFIG_LATENCYTOP
3141 REG("latency", S_IRUGO, proc_lstats_operations),
3142 #endif
3143 #ifdef CONFIG_PROC_PID_CPUSET
3144 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3145 #endif
3146 #ifdef CONFIG_CGROUPS
3147 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3148 #endif
3149 ONE("oom_score", S_IRUGO, proc_oom_score),
3150 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3151 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3152 #ifdef CONFIG_AUDITSYSCALL
3153 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3154 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3155 #endif
3156 #ifdef CONFIG_FAULT_INJECTION
3157 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3158 #endif
3159 #ifdef CONFIG_TASK_IO_ACCOUNTING
3160 ONE("io", S_IRUSR, proc_tid_io_accounting),
3161 #endif
3162 #ifdef CONFIG_HARDWALL
3163 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3164 #endif
3165 #ifdef CONFIG_USER_NS
3166 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3167 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3168 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3169 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3170 #endif
3171 };
3172
3173 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3174 {
3175 return proc_pident_readdir(file, ctx,
3176 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3177 }
3178
3179 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3180 {
3181 return proc_pident_lookup(dir, dentry,
3182 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3183 }
3184
3185 static const struct file_operations proc_tid_base_operations = {
3186 .read = generic_read_dir,
3187 .iterate = proc_tid_base_readdir,
3188 .llseek = default_llseek,
3189 };
3190
3191 static const struct inode_operations proc_tid_base_inode_operations = {
3192 .lookup = proc_tid_base_lookup,
3193 .getattr = pid_getattr,
3194 .setattr = proc_setattr,
3195 };
3196
3197 static int proc_task_instantiate(struct inode *dir,
3198 struct dentry *dentry, struct task_struct *task, const void *ptr)
3199 {
3200 struct inode *inode;
3201 inode = proc_pid_make_inode(dir->i_sb, task);
3202
3203 if (!inode)
3204 goto out;
3205 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3206 inode->i_op = &proc_tid_base_inode_operations;
3207 inode->i_fop = &proc_tid_base_operations;
3208 inode->i_flags|=S_IMMUTABLE;
3209
3210 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3211 ARRAY_SIZE(tid_base_stuff)));
3212
3213 d_set_d_op(dentry, &pid_dentry_operations);
3214
3215 d_add(dentry, inode);
3216 /* Close the race of the process dying before we return the dentry */
3217 if (pid_revalidate(dentry, 0))
3218 return 0;
3219 out:
3220 return -ENOENT;
3221 }
3222
3223 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3224 {
3225 int result = -ENOENT;
3226 struct task_struct *task;
3227 struct task_struct *leader = get_proc_task(dir);
3228 unsigned tid;
3229 struct pid_namespace *ns;
3230
3231 if (!leader)
3232 goto out_no_task;
3233
3234 tid = name_to_int(&dentry->d_name);
3235 if (tid == ~0U)
3236 goto out;
3237
3238 ns = dentry->d_sb->s_fs_info;
3239 rcu_read_lock();
3240 task = find_task_by_pid_ns(tid, ns);
3241 if (task)
3242 get_task_struct(task);
3243 rcu_read_unlock();
3244 if (!task)
3245 goto out;
3246 if (!same_thread_group(leader, task))
3247 goto out_drop_task;
3248
3249 result = proc_task_instantiate(dir, dentry, task, NULL);
3250 out_drop_task:
3251 put_task_struct(task);
3252 out:
3253 put_task_struct(leader);
3254 out_no_task:
3255 return ERR_PTR(result);
3256 }
3257
3258 /*
3259 * Find the first tid of a thread group to return to user space.
3260 *
3261 * Usually this is just the thread group leader, but if the users
3262 * buffer was too small or there was a seek into the middle of the
3263 * directory we have more work todo.
3264 *
3265 * In the case of a short read we start with find_task_by_pid.
3266 *
3267 * In the case of a seek we start with the leader and walk nr
3268 * threads past it.
3269 */
3270 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3271 struct pid_namespace *ns)
3272 {
3273 struct task_struct *pos, *task;
3274 unsigned long nr = f_pos;
3275
3276 if (nr != f_pos) /* 32bit overflow? */
3277 return NULL;
3278
3279 rcu_read_lock();
3280 task = pid_task(pid, PIDTYPE_PID);
3281 if (!task)
3282 goto fail;
3283
3284 /* Attempt to start with the tid of a thread */
3285 if (tid && nr) {
3286 pos = find_task_by_pid_ns(tid, ns);
3287 if (pos && same_thread_group(pos, task))
3288 goto found;
3289 }
3290
3291 /* If nr exceeds the number of threads there is nothing todo */
3292 if (nr >= get_nr_threads(task))
3293 goto fail;
3294
3295 /* If we haven't found our starting place yet start
3296 * with the leader and walk nr threads forward.
3297 */
3298 pos = task = task->group_leader;
3299 do {
3300 if (!nr--)
3301 goto found;
3302 } while_each_thread(task, pos);
3303 fail:
3304 pos = NULL;
3305 goto out;
3306 found:
3307 get_task_struct(pos);
3308 out:
3309 rcu_read_unlock();
3310 return pos;
3311 }
3312
3313 /*
3314 * Find the next thread in the thread list.
3315 * Return NULL if there is an error or no next thread.
3316 *
3317 * The reference to the input task_struct is released.
3318 */
3319 static struct task_struct *next_tid(struct task_struct *start)
3320 {
3321 struct task_struct *pos = NULL;
3322 rcu_read_lock();
3323 if (pid_alive(start)) {
3324 pos = next_thread(start);
3325 if (thread_group_leader(pos))
3326 pos = NULL;
3327 else
3328 get_task_struct(pos);
3329 }
3330 rcu_read_unlock();
3331 put_task_struct(start);
3332 return pos;
3333 }
3334
3335 /* for the /proc/TGID/task/ directories */
3336 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3337 {
3338 struct inode *inode = file_inode(file);
3339 struct task_struct *task;
3340 struct pid_namespace *ns;
3341 int tid;
3342
3343 if (proc_inode_is_dead(inode))
3344 return -ENOENT;
3345
3346 if (!dir_emit_dots(file, ctx))
3347 return 0;
3348
3349 /* f_version caches the tgid value that the last readdir call couldn't
3350 * return. lseek aka telldir automagically resets f_version to 0.
3351 */
3352 ns = inode->i_sb->s_fs_info;
3353 tid = (int)file->f_version;
3354 file->f_version = 0;
3355 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3356 task;
3357 task = next_tid(task), ctx->pos++) {
3358 char name[PROC_NUMBUF];
3359 int len;
3360 tid = task_pid_nr_ns(task, ns);
3361 len = snprintf(name, sizeof(name), "%d", tid);
3362 if (!proc_fill_cache(file, ctx, name, len,
3363 proc_task_instantiate, task, NULL)) {
3364 /* returning this tgid failed, save it as the first
3365 * pid for the next readir call */
3366 file->f_version = (u64)tid;
3367 put_task_struct(task);
3368 break;
3369 }
3370 }
3371
3372 return 0;
3373 }
3374
3375 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3376 {
3377 struct inode *inode = d_inode(dentry);
3378 struct task_struct *p = get_proc_task(inode);
3379 generic_fillattr(inode, stat);
3380
3381 if (p) {
3382 stat->nlink += get_nr_threads(p);
3383 put_task_struct(p);
3384 }
3385
3386 return 0;
3387 }
3388
3389 static const struct inode_operations proc_task_inode_operations = {
3390 .lookup = proc_task_lookup,
3391 .getattr = proc_task_getattr,
3392 .setattr = proc_setattr,
3393 .permission = proc_pid_permission,
3394 };
3395
3396 static const struct file_operations proc_task_operations = {
3397 .read = generic_read_dir,
3398 .iterate = proc_task_readdir,
3399 .llseek = default_llseek,
3400 };
Linux kernel - Deliverables
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