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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_follow_link(struct dentry *dentry, void **cookie)
1568 {
1569 struct inode *inode = d_inode(dentry);
1570 struct path path;
1571 int error = -EACCES;
1572
1573 /* Are we allowed to snoop on the tasks file descriptors? */
1574 if (!proc_fd_access_allowed(inode))
1575 goto out;
1576
1577 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1578 if (error)
1579 goto out;
1580
1581 nd_jump_link(&path);
1582 return NULL;
1583 out:
1584 return ERR_PTR(error);
1585 }
1586
1587 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1588 {
1589 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1590 char *pathname;
1591 int len;
1592
1593 if (!tmp)
1594 return -ENOMEM;
1595
1596 pathname = d_path(path, tmp, PAGE_SIZE);
1597 len = PTR_ERR(pathname);
1598 if (IS_ERR(pathname))
1599 goto out;
1600 len = tmp + PAGE_SIZE - 1 - pathname;
1601
1602 if (len > buflen)
1603 len = buflen;
1604 if (copy_to_user(buffer, pathname, len))
1605 len = -EFAULT;
1606 out:
1607 free_page((unsigned long)tmp);
1608 return len;
1609 }
1610
1611 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1612 {
1613 int error = -EACCES;
1614 struct inode *inode = d_inode(dentry);
1615 struct path path;
1616
1617 /* Are we allowed to snoop on the tasks file descriptors? */
1618 if (!proc_fd_access_allowed(inode))
1619 goto out;
1620
1621 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1622 if (error)
1623 goto out;
1624
1625 error = do_proc_readlink(&path, buffer, buflen);
1626 path_put(&path);
1627 out:
1628 return error;
1629 }
1630
1631 const struct inode_operations proc_pid_link_inode_operations = {
1632 .readlink = proc_pid_readlink,
1633 .follow_link = proc_pid_follow_link,
1634 .setattr = proc_setattr,
1635 };
1636
1637
1638 /* building an inode */
1639
1640 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1641 {
1642 struct inode * inode;
1643 struct proc_inode *ei;
1644 const struct cred *cred;
1645
1646 /* We need a new inode */
1647
1648 inode = new_inode(sb);
1649 if (!inode)
1650 goto out;
1651
1652 /* Common stuff */
1653 ei = PROC_I(inode);
1654 inode->i_ino = get_next_ino();
1655 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1656 inode->i_op = &proc_def_inode_operations;
1657
1658 /*
1659 * grab the reference to task.
1660 */
1661 ei->pid = get_task_pid(task, PIDTYPE_PID);
1662 if (!ei->pid)
1663 goto out_unlock;
1664
1665 if (task_dumpable(task)) {
1666 rcu_read_lock();
1667 cred = __task_cred(task);
1668 inode->i_uid = cred->euid;
1669 inode->i_gid = cred->egid;
1670 rcu_read_unlock();
1671 }
1672 security_task_to_inode(task, inode);
1673
1674 out:
1675 return inode;
1676
1677 out_unlock:
1678 iput(inode);
1679 return NULL;
1680 }
1681
1682 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1683 {
1684 struct inode *inode = d_inode(dentry);
1685 struct task_struct *task;
1686 const struct cred *cred;
1687 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1688
1689 generic_fillattr(inode, stat);
1690
1691 rcu_read_lock();
1692 stat->uid = GLOBAL_ROOT_UID;
1693 stat->gid = GLOBAL_ROOT_GID;
1694 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1695 if (task) {
1696 if (!has_pid_permissions(pid, task, 2)) {
1697 rcu_read_unlock();
1698 /*
1699 * This doesn't prevent learning whether PID exists,
1700 * it only makes getattr() consistent with readdir().
1701 */
1702 return -ENOENT;
1703 }
1704 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1705 task_dumpable(task)) {
1706 cred = __task_cred(task);
1707 stat->uid = cred->euid;
1708 stat->gid = cred->egid;
1709 }
1710 }
1711 rcu_read_unlock();
1712 return 0;
1713 }
1714
1715 /* dentry stuff */
1716
1717 /*
1718 * Exceptional case: normally we are not allowed to unhash a busy
1719 * directory. In this case, however, we can do it - no aliasing problems
1720 * due to the way we treat inodes.
1721 *
1722 * Rewrite the inode's ownerships here because the owning task may have
1723 * performed a setuid(), etc.
1724 *
1725 * Before the /proc/pid/status file was created the only way to read
1726 * the effective uid of a /process was to stat /proc/pid. Reading
1727 * /proc/pid/status is slow enough that procps and other packages
1728 * kept stating /proc/pid. To keep the rules in /proc simple I have
1729 * made this apply to all per process world readable and executable
1730 * directories.
1731 */
1732 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1733 {
1734 struct inode *inode;
1735 struct task_struct *task;
1736 const struct cred *cred;
1737
1738 if (flags & LOOKUP_RCU)
1739 return -ECHILD;
1740
1741 inode = d_inode(dentry);
1742 task = get_proc_task(inode);
1743
1744 if (task) {
1745 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1746 task_dumpable(task)) {
1747 rcu_read_lock();
1748 cred = __task_cred(task);
1749 inode->i_uid = cred->euid;
1750 inode->i_gid = cred->egid;
1751 rcu_read_unlock();
1752 } else {
1753 inode->i_uid = GLOBAL_ROOT_UID;
1754 inode->i_gid = GLOBAL_ROOT_GID;
1755 }
1756 inode->i_mode &= ~(S_ISUID | S_ISGID);
1757 security_task_to_inode(task, inode);
1758 put_task_struct(task);
1759 return 1;
1760 }
1761 return 0;
1762 }
1763
1764 static inline bool proc_inode_is_dead(struct inode *inode)
1765 {
1766 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1767 }
1768
1769 int pid_delete_dentry(const struct dentry *dentry)
1770 {
1771 /* Is the task we represent dead?
1772 * If so, then don't put the dentry on the lru list,
1773 * kill it immediately.
1774 */
1775 return proc_inode_is_dead(d_inode(dentry));
1776 }
1777
1778 const struct dentry_operations pid_dentry_operations =
1779 {
1780 .d_revalidate = pid_revalidate,
1781 .d_delete = pid_delete_dentry,
1782 };
1783
1784 /* Lookups */
1785
1786 /*
1787 * Fill a directory entry.
1788 *
1789 * If possible create the dcache entry and derive our inode number and
1790 * file type from dcache entry.
1791 *
1792 * Since all of the proc inode numbers are dynamically generated, the inode
1793 * numbers do not exist until the inode is cache. This means creating the
1794 * the dcache entry in readdir is necessary to keep the inode numbers
1795 * reported by readdir in sync with the inode numbers reported
1796 * by stat.
1797 */
1798 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1799 const char *name, int len,
1800 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1801 {
1802 struct dentry *child, *dir = file->f_path.dentry;
1803 struct qstr qname = QSTR_INIT(name, len);
1804 struct inode *inode;
1805 unsigned type;
1806 ino_t ino;
1807
1808 child = d_hash_and_lookup(dir, &qname);
1809 if (!child) {
1810 child = d_alloc(dir, &qname);
1811 if (!child)
1812 goto end_instantiate;
1813 if (instantiate(d_inode(dir), child, task, ptr) < 0) {
1814 dput(child);
1815 goto end_instantiate;
1816 }
1817 }
1818 inode = d_inode(child);
1819 ino = inode->i_ino;
1820 type = inode->i_mode >> 12;
1821 dput(child);
1822 return dir_emit(ctx, name, len, ino, type);
1823
1824 end_instantiate:
1825 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1826 }
1827
1828 /*
1829 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1830 * which represent vma start and end addresses.
1831 */
1832 static int dname_to_vma_addr(struct dentry *dentry,
1833 unsigned long *start, unsigned long *end)
1834 {
1835 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1836 return -EINVAL;
1837
1838 return 0;
1839 }
1840
1841 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1842 {
1843 unsigned long vm_start, vm_end;
1844 bool exact_vma_exists = false;
1845 struct mm_struct *mm = NULL;
1846 struct task_struct *task;
1847 const struct cred *cred;
1848 struct inode *inode;
1849 int status = 0;
1850
1851 if (flags & LOOKUP_RCU)
1852 return -ECHILD;
1853
1854 inode = d_inode(dentry);
1855 task = get_proc_task(inode);
1856 if (!task)
1857 goto out_notask;
1858
1859 mm = mm_access(task, PTRACE_MODE_READ);
1860 if (IS_ERR_OR_NULL(mm))
1861 goto out;
1862
1863 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1864 down_read(&mm->mmap_sem);
1865 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1866 up_read(&mm->mmap_sem);
1867 }
1868
1869 mmput(mm);
1870
1871 if (exact_vma_exists) {
1872 if (task_dumpable(task)) {
1873 rcu_read_lock();
1874 cred = __task_cred(task);
1875 inode->i_uid = cred->euid;
1876 inode->i_gid = cred->egid;
1877 rcu_read_unlock();
1878 } else {
1879 inode->i_uid = GLOBAL_ROOT_UID;
1880 inode->i_gid = GLOBAL_ROOT_GID;
1881 }
1882 security_task_to_inode(task, inode);
1883 status = 1;
1884 }
1885
1886 out:
1887 put_task_struct(task);
1888
1889 out_notask:
1890 return status;
1891 }
1892
1893 static const struct dentry_operations tid_map_files_dentry_operations = {
1894 .d_revalidate = map_files_d_revalidate,
1895 .d_delete = pid_delete_dentry,
1896 };
1897
1898 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1899 {
1900 unsigned long vm_start, vm_end;
1901 struct vm_area_struct *vma;
1902 struct task_struct *task;
1903 struct mm_struct *mm;
1904 int rc;
1905
1906 rc = -ENOENT;
1907 task = get_proc_task(d_inode(dentry));
1908 if (!task)
1909 goto out;
1910
1911 mm = get_task_mm(task);
1912 put_task_struct(task);
1913 if (!mm)
1914 goto out;
1915
1916 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1917 if (rc)
1918 goto out_mmput;
1919
1920 rc = -ENOENT;
1921 down_read(&mm->mmap_sem);
1922 vma = find_exact_vma(mm, vm_start, vm_end);
1923 if (vma && vma->vm_file) {
1924 *path = vma->vm_file->f_path;
1925 path_get(path);
1926 rc = 0;
1927 }
1928 up_read(&mm->mmap_sem);
1929
1930 out_mmput:
1931 mmput(mm);
1932 out:
1933 return rc;
1934 }
1935
1936 struct map_files_info {
1937 fmode_t mode;
1938 unsigned long len;
1939 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1940 };
1941
1942 /*
1943 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1944 * symlinks may be used to bypass permissions on ancestor directories in the
1945 * path to the file in question.
1946 */
1947 static const char *
1948 proc_map_files_follow_link(struct dentry *dentry, void **cookie)
1949 {
1950 if (!capable(CAP_SYS_ADMIN))
1951 return ERR_PTR(-EPERM);
1952
1953 return proc_pid_follow_link(dentry, NULL);
1954 }
1955
1956 /*
1957 * Identical to proc_pid_link_inode_operations except for follow_link()
1958 */
1959 static const struct inode_operations proc_map_files_link_inode_operations = {
1960 .readlink = proc_pid_readlink,
1961 .follow_link = proc_map_files_follow_link,
1962 .setattr = proc_setattr,
1963 };
1964
1965 static int
1966 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1967 struct task_struct *task, const void *ptr)
1968 {
1969 fmode_t mode = (fmode_t)(unsigned long)ptr;
1970 struct proc_inode *ei;
1971 struct inode *inode;
1972
1973 inode = proc_pid_make_inode(dir->i_sb, task);
1974 if (!inode)
1975 return -ENOENT;
1976
1977 ei = PROC_I(inode);
1978 ei->op.proc_get_link = proc_map_files_get_link;
1979
1980 inode->i_op = &proc_map_files_link_inode_operations;
1981 inode->i_size = 64;
1982 inode->i_mode = S_IFLNK;
1983
1984 if (mode & FMODE_READ)
1985 inode->i_mode |= S_IRUSR;
1986 if (mode & FMODE_WRITE)
1987 inode->i_mode |= S_IWUSR;
1988
1989 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1990 d_add(dentry, inode);
1991
1992 return 0;
1993 }
1994
1995 static struct dentry *proc_map_files_lookup(struct inode *dir,
1996 struct dentry *dentry, unsigned int flags)
1997 {
1998 unsigned long vm_start, vm_end;
1999 struct vm_area_struct *vma;
2000 struct task_struct *task;
2001 int result;
2002 struct mm_struct *mm;
2003
2004 result = -ENOENT;
2005 task = get_proc_task(dir);
2006 if (!task)
2007 goto out;
2008
2009 result = -EACCES;
2010 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2011 goto out_put_task;
2012
2013 result = -ENOENT;
2014 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2015 goto out_put_task;
2016
2017 mm = get_task_mm(task);
2018 if (!mm)
2019 goto out_put_task;
2020
2021 down_read(&mm->mmap_sem);
2022 vma = find_exact_vma(mm, vm_start, vm_end);
2023 if (!vma)
2024 goto out_no_vma;
2025
2026 if (vma->vm_file)
2027 result = proc_map_files_instantiate(dir, dentry, task,
2028 (void *)(unsigned long)vma->vm_file->f_mode);
2029
2030 out_no_vma:
2031 up_read(&mm->mmap_sem);
2032 mmput(mm);
2033 out_put_task:
2034 put_task_struct(task);
2035 out:
2036 return ERR_PTR(result);
2037 }
2038
2039 static const struct inode_operations proc_map_files_inode_operations = {
2040 .lookup = proc_map_files_lookup,
2041 .permission = proc_fd_permission,
2042 .setattr = proc_setattr,
2043 };
2044
2045 static int
2046 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2047 {
2048 struct vm_area_struct *vma;
2049 struct task_struct *task;
2050 struct mm_struct *mm;
2051 unsigned long nr_files, pos, i;
2052 struct flex_array *fa = NULL;
2053 struct map_files_info info;
2054 struct map_files_info *p;
2055 int ret;
2056
2057 ret = -ENOENT;
2058 task = get_proc_task(file_inode(file));
2059 if (!task)
2060 goto out;
2061
2062 ret = -EACCES;
2063 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2064 goto out_put_task;
2065
2066 ret = 0;
2067 if (!dir_emit_dots(file, ctx))
2068 goto out_put_task;
2069
2070 mm = get_task_mm(task);
2071 if (!mm)
2072 goto out_put_task;
2073 down_read(&mm->mmap_sem);
2074
2075 nr_files = 0;
2076
2077 /*
2078 * We need two passes here:
2079 *
2080 * 1) Collect vmas of mapped files with mmap_sem taken
2081 * 2) Release mmap_sem and instantiate entries
2082 *
2083 * otherwise we get lockdep complained, since filldir()
2084 * routine might require mmap_sem taken in might_fault().
2085 */
2086
2087 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2088 if (vma->vm_file && ++pos > ctx->pos)
2089 nr_files++;
2090 }
2091
2092 if (nr_files) {
2093 fa = flex_array_alloc(sizeof(info), nr_files,
2094 GFP_KERNEL);
2095 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2096 GFP_KERNEL)) {
2097 ret = -ENOMEM;
2098 if (fa)
2099 flex_array_free(fa);
2100 up_read(&mm->mmap_sem);
2101 mmput(mm);
2102 goto out_put_task;
2103 }
2104 for (i = 0, vma = mm->mmap, pos = 2; vma;
2105 vma = vma->vm_next) {
2106 if (!vma->vm_file)
2107 continue;
2108 if (++pos <= ctx->pos)
2109 continue;
2110
2111 info.mode = vma->vm_file->f_mode;
2112 info.len = snprintf(info.name,
2113 sizeof(info.name), "%lx-%lx",
2114 vma->vm_start, vma->vm_end);
2115 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2116 BUG();
2117 }
2118 }
2119 up_read(&mm->mmap_sem);
2120
2121 for (i = 0; i < nr_files; i++) {
2122 p = flex_array_get(fa, i);
2123 if (!proc_fill_cache(file, ctx,
2124 p->name, p->len,
2125 proc_map_files_instantiate,
2126 task,
2127 (void *)(unsigned long)p->mode))
2128 break;
2129 ctx->pos++;
2130 }
2131 if (fa)
2132 flex_array_free(fa);
2133 mmput(mm);
2134
2135 out_put_task:
2136 put_task_struct(task);
2137 out:
2138 return ret;
2139 }
2140
2141 static const struct file_operations proc_map_files_operations = {
2142 .read = generic_read_dir,
2143 .iterate = proc_map_files_readdir,
2144 .llseek = default_llseek,
2145 };
2146
2147 struct timers_private {
2148 struct pid *pid;
2149 struct task_struct *task;
2150 struct sighand_struct *sighand;
2151 struct pid_namespace *ns;
2152 unsigned long flags;
2153 };
2154
2155 static void *timers_start(struct seq_file *m, loff_t *pos)
2156 {
2157 struct timers_private *tp = m->private;
2158
2159 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2160 if (!tp->task)
2161 return ERR_PTR(-ESRCH);
2162
2163 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2164 if (!tp->sighand)
2165 return ERR_PTR(-ESRCH);
2166
2167 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2168 }
2169
2170 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2171 {
2172 struct timers_private *tp = m->private;
2173 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2174 }
2175
2176 static void timers_stop(struct seq_file *m, void *v)
2177 {
2178 struct timers_private *tp = m->private;
2179
2180 if (tp->sighand) {
2181 unlock_task_sighand(tp->task, &tp->flags);
2182 tp->sighand = NULL;
2183 }
2184
2185 if (tp->task) {
2186 put_task_struct(tp->task);
2187 tp->task = NULL;
2188 }
2189 }
2190
2191 static int show_timer(struct seq_file *m, void *v)
2192 {
2193 struct k_itimer *timer;
2194 struct timers_private *tp = m->private;
2195 int notify;
2196 static const char * const nstr[] = {
2197 [SIGEV_SIGNAL] = "signal",
2198 [SIGEV_NONE] = "none",
2199 [SIGEV_THREAD] = "thread",
2200 };
2201
2202 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2203 notify = timer->it_sigev_notify;
2204
2205 seq_printf(m, "ID: %d\n", timer->it_id);
2206 seq_printf(m, "signal: %d/%p\n",
2207 timer->sigq->info.si_signo,
2208 timer->sigq->info.si_value.sival_ptr);
2209 seq_printf(m, "notify: %s/%s.%d\n",
2210 nstr[notify & ~SIGEV_THREAD_ID],
2211 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2212 pid_nr_ns(timer->it_pid, tp->ns));
2213 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2214
2215 return 0;
2216 }
2217
2218 static const struct seq_operations proc_timers_seq_ops = {
2219 .start = timers_start,
2220 .next = timers_next,
2221 .stop = timers_stop,
2222 .show = show_timer,
2223 };
2224
2225 static int proc_timers_open(struct inode *inode, struct file *file)
2226 {
2227 struct timers_private *tp;
2228
2229 tp = __seq_open_private(file, &proc_timers_seq_ops,
2230 sizeof(struct timers_private));
2231 if (!tp)
2232 return -ENOMEM;
2233
2234 tp->pid = proc_pid(inode);
2235 tp->ns = inode->i_sb->s_fs_info;
2236 return 0;
2237 }
2238
2239 static const struct file_operations proc_timers_operations = {
2240 .open = proc_timers_open,
2241 .read = seq_read,
2242 .llseek = seq_lseek,
2243 .release = seq_release_private,
2244 };
2245
2246 static int proc_pident_instantiate(struct inode *dir,
2247 struct dentry *dentry, struct task_struct *task, const void *ptr)
2248 {
2249 const struct pid_entry *p = ptr;
2250 struct inode *inode;
2251 struct proc_inode *ei;
2252
2253 inode = proc_pid_make_inode(dir->i_sb, task);
2254 if (!inode)
2255 goto out;
2256
2257 ei = PROC_I(inode);
2258 inode->i_mode = p->mode;
2259 if (S_ISDIR(inode->i_mode))
2260 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2261 if (p->iop)
2262 inode->i_op = p->iop;
2263 if (p->fop)
2264 inode->i_fop = p->fop;
2265 ei->op = p->op;
2266 d_set_d_op(dentry, &pid_dentry_operations);
2267 d_add(dentry, inode);
2268 /* Close the race of the process dying before we return the dentry */
2269 if (pid_revalidate(dentry, 0))
2270 return 0;
2271 out:
2272 return -ENOENT;
2273 }
2274
2275 static struct dentry *proc_pident_lookup(struct inode *dir,
2276 struct dentry *dentry,
2277 const struct pid_entry *ents,
2278 unsigned int nents)
2279 {
2280 int error;
2281 struct task_struct *task = get_proc_task(dir);
2282 const struct pid_entry *p, *last;
2283
2284 error = -ENOENT;
2285
2286 if (!task)
2287 goto out_no_task;
2288
2289 /*
2290 * Yes, it does not scale. And it should not. Don't add
2291 * new entries into /proc/<tgid>/ without very good reasons.
2292 */
2293 last = &ents[nents - 1];
2294 for (p = ents; p <= last; p++) {
2295 if (p->len != dentry->d_name.len)
2296 continue;
2297 if (!memcmp(dentry->d_name.name, p->name, p->len))
2298 break;
2299 }
2300 if (p > last)
2301 goto out;
2302
2303 error = proc_pident_instantiate(dir, dentry, task, p);
2304 out:
2305 put_task_struct(task);
2306 out_no_task:
2307 return ERR_PTR(error);
2308 }
2309
2310 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2311 const struct pid_entry *ents, unsigned int nents)
2312 {
2313 struct task_struct *task = get_proc_task(file_inode(file));
2314 const struct pid_entry *p;
2315
2316 if (!task)
2317 return -ENOENT;
2318
2319 if (!dir_emit_dots(file, ctx))
2320 goto out;
2321
2322 if (ctx->pos >= nents + 2)
2323 goto out;
2324
2325 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2326 if (!proc_fill_cache(file, ctx, p->name, p->len,
2327 proc_pident_instantiate, task, p))
2328 break;
2329 ctx->pos++;
2330 }
2331 out:
2332 put_task_struct(task);
2333 return 0;
2334 }
2335
2336 #ifdef CONFIG_SECURITY
2337 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2338 size_t count, loff_t *ppos)
2339 {
2340 struct inode * inode = file_inode(file);
2341 char *p = NULL;
2342 ssize_t length;
2343 struct task_struct *task = get_proc_task(inode);
2344
2345 if (!task)
2346 return -ESRCH;
2347
2348 length = security_getprocattr(task,
2349 (char*)file->f_path.dentry->d_name.name,
2350 &p);
2351 put_task_struct(task);
2352 if (length > 0)
2353 length = simple_read_from_buffer(buf, count, ppos, p, length);
2354 kfree(p);
2355 return length;
2356 }
2357
2358 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2359 size_t count, loff_t *ppos)
2360 {
2361 struct inode * inode = file_inode(file);
2362 char *page;
2363 ssize_t length;
2364 struct task_struct *task = get_proc_task(inode);
2365
2366 length = -ESRCH;
2367 if (!task)
2368 goto out_no_task;
2369 if (count > PAGE_SIZE)
2370 count = PAGE_SIZE;
2371
2372 /* No partial writes. */
2373 length = -EINVAL;
2374 if (*ppos != 0)
2375 goto out;
2376
2377 length = -ENOMEM;
2378 page = (char*)__get_free_page(GFP_TEMPORARY);
2379 if (!page)
2380 goto out;
2381
2382 length = -EFAULT;
2383 if (copy_from_user(page, buf, count))
2384 goto out_free;
2385
2386 /* Guard against adverse ptrace interaction */
2387 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2388 if (length < 0)
2389 goto out_free;
2390
2391 length = security_setprocattr(task,
2392 (char*)file->f_path.dentry->d_name.name,
2393 (void*)page, count);
2394 mutex_unlock(&task->signal->cred_guard_mutex);
2395 out_free:
2396 free_page((unsigned long) page);
2397 out:
2398 put_task_struct(task);
2399 out_no_task:
2400 return length;
2401 }
2402
2403 static const struct file_operations proc_pid_attr_operations = {
2404 .read = proc_pid_attr_read,
2405 .write = proc_pid_attr_write,
2406 .llseek = generic_file_llseek,
2407 };
2408
2409 static const struct pid_entry attr_dir_stuff[] = {
2410 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2411 REG("prev", S_IRUGO, proc_pid_attr_operations),
2412 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2413 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2414 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2415 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2416 };
2417
2418 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2419 {
2420 return proc_pident_readdir(file, ctx,
2421 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2422 }
2423
2424 static const struct file_operations proc_attr_dir_operations = {
2425 .read = generic_read_dir,
2426 .iterate = proc_attr_dir_readdir,
2427 .llseek = default_llseek,
2428 };
2429
2430 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2431 struct dentry *dentry, unsigned int flags)
2432 {
2433 return proc_pident_lookup(dir, dentry,
2434 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2435 }
2436
2437 static const struct inode_operations proc_attr_dir_inode_operations = {
2438 .lookup = proc_attr_dir_lookup,
2439 .getattr = pid_getattr,
2440 .setattr = proc_setattr,
2441 };
2442
2443 #endif
2444
2445 #ifdef CONFIG_ELF_CORE
2446 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2447 size_t count, loff_t *ppos)
2448 {
2449 struct task_struct *task = get_proc_task(file_inode(file));
2450 struct mm_struct *mm;
2451 char buffer[PROC_NUMBUF];
2452 size_t len;
2453 int ret;
2454
2455 if (!task)
2456 return -ESRCH;
2457
2458 ret = 0;
2459 mm = get_task_mm(task);
2460 if (mm) {
2461 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2462 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2463 MMF_DUMP_FILTER_SHIFT));
2464 mmput(mm);
2465 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2466 }
2467
2468 put_task_struct(task);
2469
2470 return ret;
2471 }
2472
2473 static ssize_t proc_coredump_filter_write(struct file *file,
2474 const char __user *buf,
2475 size_t count,
2476 loff_t *ppos)
2477 {
2478 struct task_struct *task;
2479 struct mm_struct *mm;
2480 unsigned int val;
2481 int ret;
2482 int i;
2483 unsigned long mask;
2484
2485 ret = kstrtouint_from_user(buf, count, 0, &val);
2486 if (ret < 0)
2487 return ret;
2488
2489 ret = -ESRCH;
2490 task = get_proc_task(file_inode(file));
2491 if (!task)
2492 goto out_no_task;
2493
2494 mm = get_task_mm(task);
2495 if (!mm)
2496 goto out_no_mm;
2497 ret = 0;
2498
2499 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2500 if (val & mask)
2501 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2502 else
2503 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2504 }
2505
2506 mmput(mm);
2507 out_no_mm:
2508 put_task_struct(task);
2509 out_no_task:
2510 if (ret < 0)
2511 return ret;
2512 return count;
2513 }
2514
2515 static const struct file_operations proc_coredump_filter_operations = {
2516 .read = proc_coredump_filter_read,
2517 .write = proc_coredump_filter_write,
2518 .llseek = generic_file_llseek,
2519 };
2520 #endif
2521
2522 #ifdef CONFIG_TASK_IO_ACCOUNTING
2523 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2524 {
2525 struct task_io_accounting acct = task->ioac;
2526 unsigned long flags;
2527 int result;
2528
2529 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2530 if (result)
2531 return result;
2532
2533 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2534 result = -EACCES;
2535 goto out_unlock;
2536 }
2537
2538 if (whole && lock_task_sighand(task, &flags)) {
2539 struct task_struct *t = task;
2540
2541 task_io_accounting_add(&acct, &task->signal->ioac);
2542 while_each_thread(task, t)
2543 task_io_accounting_add(&acct, &t->ioac);
2544
2545 unlock_task_sighand(task, &flags);
2546 }
2547 seq_printf(m,
2548 "rchar: %llu\n"
2549 "wchar: %llu\n"
2550 "syscr: %llu\n"
2551 "syscw: %llu\n"
2552 "read_bytes: %llu\n"
2553 "write_bytes: %llu\n"
2554 "cancelled_write_bytes: %llu\n",
2555 (unsigned long long)acct.rchar,
2556 (unsigned long long)acct.wchar,
2557 (unsigned long long)acct.syscr,
2558 (unsigned long long)acct.syscw,
2559 (unsigned long long)acct.read_bytes,
2560 (unsigned long long)acct.write_bytes,
2561 (unsigned long long)acct.cancelled_write_bytes);
2562 result = 0;
2563
2564 out_unlock:
2565 mutex_unlock(&task->signal->cred_guard_mutex);
2566 return result;
2567 }
2568
2569 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2570 struct pid *pid, struct task_struct *task)
2571 {
2572 return do_io_accounting(task, m, 0);
2573 }
2574
2575 static int proc_tgid_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, 1);
2579 }
2580 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2581
2582 #ifdef CONFIG_USER_NS
2583 static int proc_id_map_open(struct inode *inode, struct file *file,
2584 const struct seq_operations *seq_ops)
2585 {
2586 struct user_namespace *ns = NULL;
2587 struct task_struct *task;
2588 struct seq_file *seq;
2589 int ret = -EINVAL;
2590
2591 task = get_proc_task(inode);
2592 if (task) {
2593 rcu_read_lock();
2594 ns = get_user_ns(task_cred_xxx(task, user_ns));
2595 rcu_read_unlock();
2596 put_task_struct(task);
2597 }
2598 if (!ns)
2599 goto err;
2600
2601 ret = seq_open(file, seq_ops);
2602 if (ret)
2603 goto err_put_ns;
2604
2605 seq = file->private_data;
2606 seq->private = ns;
2607
2608 return 0;
2609 err_put_ns:
2610 put_user_ns(ns);
2611 err:
2612 return ret;
2613 }
2614
2615 static int proc_id_map_release(struct inode *inode, struct file *file)
2616 {
2617 struct seq_file *seq = file->private_data;
2618 struct user_namespace *ns = seq->private;
2619 put_user_ns(ns);
2620 return seq_release(inode, file);
2621 }
2622
2623 static int proc_uid_map_open(struct inode *inode, struct file *file)
2624 {
2625 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2626 }
2627
2628 static int proc_gid_map_open(struct inode *inode, struct file *file)
2629 {
2630 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2631 }
2632
2633 static int proc_projid_map_open(struct inode *inode, struct file *file)
2634 {
2635 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2636 }
2637
2638 static const struct file_operations proc_uid_map_operations = {
2639 .open = proc_uid_map_open,
2640 .write = proc_uid_map_write,
2641 .read = seq_read,
2642 .llseek = seq_lseek,
2643 .release = proc_id_map_release,
2644 };
2645
2646 static const struct file_operations proc_gid_map_operations = {
2647 .open = proc_gid_map_open,
2648 .write = proc_gid_map_write,
2649 .read = seq_read,
2650 .llseek = seq_lseek,
2651 .release = proc_id_map_release,
2652 };
2653
2654 static const struct file_operations proc_projid_map_operations = {
2655 .open = proc_projid_map_open,
2656 .write = proc_projid_map_write,
2657 .read = seq_read,
2658 .llseek = seq_lseek,
2659 .release = proc_id_map_release,
2660 };
2661
2662 static int proc_setgroups_open(struct inode *inode, struct file *file)
2663 {
2664 struct user_namespace *ns = NULL;
2665 struct task_struct *task;
2666 int ret;
2667
2668 ret = -ESRCH;
2669 task = get_proc_task(inode);
2670 if (task) {
2671 rcu_read_lock();
2672 ns = get_user_ns(task_cred_xxx(task, user_ns));
2673 rcu_read_unlock();
2674 put_task_struct(task);
2675 }
2676 if (!ns)
2677 goto err;
2678
2679 if (file->f_mode & FMODE_WRITE) {
2680 ret = -EACCES;
2681 if (!ns_capable(ns, CAP_SYS_ADMIN))
2682 goto err_put_ns;
2683 }
2684
2685 ret = single_open(file, &proc_setgroups_show, ns);
2686 if (ret)
2687 goto err_put_ns;
2688
2689 return 0;
2690 err_put_ns:
2691 put_user_ns(ns);
2692 err:
2693 return ret;
2694 }
2695
2696 static int proc_setgroups_release(struct inode *inode, struct file *file)
2697 {
2698 struct seq_file *seq = file->private_data;
2699 struct user_namespace *ns = seq->private;
2700 int ret = single_release(inode, file);
2701 put_user_ns(ns);
2702 return ret;
2703 }
2704
2705 static const struct file_operations proc_setgroups_operations = {
2706 .open = proc_setgroups_open,
2707 .write = proc_setgroups_write,
2708 .read = seq_read,
2709 .llseek = seq_lseek,
2710 .release = proc_setgroups_release,
2711 };
2712 #endif /* CONFIG_USER_NS */
2713
2714 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2715 struct pid *pid, struct task_struct *task)
2716 {
2717 int err = lock_trace(task);
2718 if (!err) {
2719 seq_printf(m, "%08x\n", task->personality);
2720 unlock_trace(task);
2721 }
2722 return err;
2723 }
2724
2725 /*
2726 * Thread groups
2727 */
2728 static const struct file_operations proc_task_operations;
2729 static const struct inode_operations proc_task_inode_operations;
2730
2731 static const struct pid_entry tgid_base_stuff[] = {
2732 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2733 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2734 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2735 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2736 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2737 #ifdef CONFIG_NET
2738 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2739 #endif
2740 REG("environ", S_IRUSR, proc_environ_operations),
2741 ONE("auxv", S_IRUSR, proc_pid_auxv),
2742 ONE("status", S_IRUGO, proc_pid_status),
2743 ONE("personality", S_IRUSR, proc_pid_personality),
2744 ONE("limits", S_IRUGO, proc_pid_limits),
2745 #ifdef CONFIG_SCHED_DEBUG
2746 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2747 #endif
2748 #ifdef CONFIG_SCHED_AUTOGROUP
2749 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2750 #endif
2751 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2752 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2753 ONE("syscall", S_IRUSR, proc_pid_syscall),
2754 #endif
2755 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2756 ONE("stat", S_IRUGO, proc_tgid_stat),
2757 ONE("statm", S_IRUGO, proc_pid_statm),
2758 REG("maps", S_IRUGO, proc_pid_maps_operations),
2759 #ifdef CONFIG_NUMA
2760 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2761 #endif
2762 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2763 LNK("cwd", proc_cwd_link),
2764 LNK("root", proc_root_link),
2765 LNK("exe", proc_exe_link),
2766 REG("mounts", S_IRUGO, proc_mounts_operations),
2767 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2768 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2769 #ifdef CONFIG_PROC_PAGE_MONITOR
2770 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2771 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2772 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2773 #endif
2774 #ifdef CONFIG_SECURITY
2775 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2776 #endif
2777 #ifdef CONFIG_KALLSYMS
2778 ONE("wchan", S_IRUGO, proc_pid_wchan),
2779 #endif
2780 #ifdef CONFIG_STACKTRACE
2781 ONE("stack", S_IRUSR, proc_pid_stack),
2782 #endif
2783 #ifdef CONFIG_SCHED_INFO
2784 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2785 #endif
2786 #ifdef CONFIG_LATENCYTOP
2787 REG("latency", S_IRUGO, proc_lstats_operations),
2788 #endif
2789 #ifdef CONFIG_PROC_PID_CPUSET
2790 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2791 #endif
2792 #ifdef CONFIG_CGROUPS
2793 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2794 #endif
2795 ONE("oom_score", S_IRUGO, proc_oom_score),
2796 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2797 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2798 #ifdef CONFIG_AUDITSYSCALL
2799 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2800 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2801 #endif
2802 #ifdef CONFIG_FAULT_INJECTION
2803 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2804 #endif
2805 #ifdef CONFIG_ELF_CORE
2806 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2807 #endif
2808 #ifdef CONFIG_TASK_IO_ACCOUNTING
2809 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2810 #endif
2811 #ifdef CONFIG_HARDWALL
2812 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2813 #endif
2814 #ifdef CONFIG_USER_NS
2815 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2816 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2817 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2818 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2819 #endif
2820 #ifdef CONFIG_CHECKPOINT_RESTORE
2821 REG("timers", S_IRUGO, proc_timers_operations),
2822 #endif
2823 };
2824
2825 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2826 {
2827 return proc_pident_readdir(file, ctx,
2828 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2829 }
2830
2831 static const struct file_operations proc_tgid_base_operations = {
2832 .read = generic_read_dir,
2833 .iterate = proc_tgid_base_readdir,
2834 .llseek = default_llseek,
2835 };
2836
2837 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2838 {
2839 return proc_pident_lookup(dir, dentry,
2840 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2841 }
2842
2843 static const struct inode_operations proc_tgid_base_inode_operations = {
2844 .lookup = proc_tgid_base_lookup,
2845 .getattr = pid_getattr,
2846 .setattr = proc_setattr,
2847 .permission = proc_pid_permission,
2848 };
2849
2850 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2851 {
2852 struct dentry *dentry, *leader, *dir;
2853 char buf[PROC_NUMBUF];
2854 struct qstr name;
2855
2856 name.name = buf;
2857 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2858 /* no ->d_hash() rejects on procfs */
2859 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2860 if (dentry) {
2861 d_invalidate(dentry);
2862 dput(dentry);
2863 }
2864
2865 if (pid == tgid)
2866 return;
2867
2868 name.name = buf;
2869 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2870 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2871 if (!leader)
2872 goto out;
2873
2874 name.name = "task";
2875 name.len = strlen(name.name);
2876 dir = d_hash_and_lookup(leader, &name);
2877 if (!dir)
2878 goto out_put_leader;
2879
2880 name.name = buf;
2881 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2882 dentry = d_hash_and_lookup(dir, &name);
2883 if (dentry) {
2884 d_invalidate(dentry);
2885 dput(dentry);
2886 }
2887
2888 dput(dir);
2889 out_put_leader:
2890 dput(leader);
2891 out:
2892 return;
2893 }
2894
2895 /**
2896 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2897 * @task: task that should be flushed.
2898 *
2899 * When flushing dentries from proc, one needs to flush them from global
2900 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2901 * in. This call is supposed to do all of this job.
2902 *
2903 * Looks in the dcache for
2904 * /proc/@pid
2905 * /proc/@tgid/task/@pid
2906 * if either directory is present flushes it and all of it'ts children
2907 * from the dcache.
2908 *
2909 * It is safe and reasonable to cache /proc entries for a task until
2910 * that task exits. After that they just clog up the dcache with
2911 * useless entries, possibly causing useful dcache entries to be
2912 * flushed instead. This routine is proved to flush those useless
2913 * dcache entries at process exit time.
2914 *
2915 * NOTE: This routine is just an optimization so it does not guarantee
2916 * that no dcache entries will exist at process exit time it
2917 * just makes it very unlikely that any will persist.
2918 */
2919
2920 void proc_flush_task(struct task_struct *task)
2921 {
2922 int i;
2923 struct pid *pid, *tgid;
2924 struct upid *upid;
2925
2926 pid = task_pid(task);
2927 tgid = task_tgid(task);
2928
2929 for (i = 0; i <= pid->level; i++) {
2930 upid = &pid->numbers[i];
2931 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2932 tgid->numbers[i].nr);
2933 }
2934 }
2935
2936 static int proc_pid_instantiate(struct inode *dir,
2937 struct dentry * dentry,
2938 struct task_struct *task, const void *ptr)
2939 {
2940 struct inode *inode;
2941
2942 inode = proc_pid_make_inode(dir->i_sb, task);
2943 if (!inode)
2944 goto out;
2945
2946 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2947 inode->i_op = &proc_tgid_base_inode_operations;
2948 inode->i_fop = &proc_tgid_base_operations;
2949 inode->i_flags|=S_IMMUTABLE;
2950
2951 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2952 ARRAY_SIZE(tgid_base_stuff)));
2953
2954 d_set_d_op(dentry, &pid_dentry_operations);
2955
2956 d_add(dentry, inode);
2957 /* Close the race of the process dying before we return the dentry */
2958 if (pid_revalidate(dentry, 0))
2959 return 0;
2960 out:
2961 return -ENOENT;
2962 }
2963
2964 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2965 {
2966 int result = -ENOENT;
2967 struct task_struct *task;
2968 unsigned tgid;
2969 struct pid_namespace *ns;
2970
2971 tgid = name_to_int(&dentry->d_name);
2972 if (tgid == ~0U)
2973 goto out;
2974
2975 ns = dentry->d_sb->s_fs_info;
2976 rcu_read_lock();
2977 task = find_task_by_pid_ns(tgid, ns);
2978 if (task)
2979 get_task_struct(task);
2980 rcu_read_unlock();
2981 if (!task)
2982 goto out;
2983
2984 result = proc_pid_instantiate(dir, dentry, task, NULL);
2985 put_task_struct(task);
2986 out:
2987 return ERR_PTR(result);
2988 }
2989
2990 /*
2991 * Find the first task with tgid >= tgid
2992 *
2993 */
2994 struct tgid_iter {
2995 unsigned int tgid;
2996 struct task_struct *task;
2997 };
2998 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2999 {
3000 struct pid *pid;
3001
3002 if (iter.task)
3003 put_task_struct(iter.task);
3004 rcu_read_lock();
3005 retry:
3006 iter.task = NULL;
3007 pid = find_ge_pid(iter.tgid, ns);
3008 if (pid) {
3009 iter.tgid = pid_nr_ns(pid, ns);
3010 iter.task = pid_task(pid, PIDTYPE_PID);
3011 /* What we to know is if the pid we have find is the
3012 * pid of a thread_group_leader. Testing for task
3013 * being a thread_group_leader is the obvious thing
3014 * todo but there is a window when it fails, due to
3015 * the pid transfer logic in de_thread.
3016 *
3017 * So we perform the straight forward test of seeing
3018 * if the pid we have found is the pid of a thread
3019 * group leader, and don't worry if the task we have
3020 * found doesn't happen to be a thread group leader.
3021 * As we don't care in the case of readdir.
3022 */
3023 if (!iter.task || !has_group_leader_pid(iter.task)) {
3024 iter.tgid += 1;
3025 goto retry;
3026 }
3027 get_task_struct(iter.task);
3028 }
3029 rcu_read_unlock();
3030 return iter;
3031 }
3032
3033 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3034
3035 /* for the /proc/ directory itself, after non-process stuff has been done */
3036 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3037 {
3038 struct tgid_iter iter;
3039 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3040 loff_t pos = ctx->pos;
3041
3042 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3043 return 0;
3044
3045 if (pos == TGID_OFFSET - 2) {
3046 struct inode *inode = d_inode(ns->proc_self);
3047 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3048 return 0;
3049 ctx->pos = pos = pos + 1;
3050 }
3051 if (pos == TGID_OFFSET - 1) {
3052 struct inode *inode = d_inode(ns->proc_thread_self);
3053 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3054 return 0;
3055 ctx->pos = pos = pos + 1;
3056 }
3057 iter.tgid = pos - TGID_OFFSET;
3058 iter.task = NULL;
3059 for (iter = next_tgid(ns, iter);
3060 iter.task;
3061 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3062 char name[PROC_NUMBUF];
3063 int len;
3064 if (!has_pid_permissions(ns, iter.task, 2))
3065 continue;
3066
3067 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3068 ctx->pos = iter.tgid + TGID_OFFSET;
3069 if (!proc_fill_cache(file, ctx, name, len,
3070 proc_pid_instantiate, iter.task, NULL)) {
3071 put_task_struct(iter.task);
3072 return 0;
3073 }
3074 }
3075 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3076 return 0;
3077 }
3078
3079 /*
3080 * Tasks
3081 */
3082 static const struct pid_entry tid_base_stuff[] = {
3083 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3084 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3085 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3086 #ifdef CONFIG_NET
3087 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3088 #endif
3089 REG("environ", S_IRUSR, proc_environ_operations),
3090 ONE("auxv", S_IRUSR, proc_pid_auxv),
3091 ONE("status", S_IRUGO, proc_pid_status),
3092 ONE("personality", S_IRUSR, proc_pid_personality),
3093 ONE("limits", S_IRUGO, proc_pid_limits),
3094 #ifdef CONFIG_SCHED_DEBUG
3095 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3096 #endif
3097 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3098 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3099 ONE("syscall", S_IRUSR, proc_pid_syscall),
3100 #endif
3101 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3102 ONE("stat", S_IRUGO, proc_tid_stat),
3103 ONE("statm", S_IRUGO, proc_pid_statm),
3104 REG("maps", S_IRUGO, proc_tid_maps_operations),
3105 #ifdef CONFIG_PROC_CHILDREN
3106 REG("children", S_IRUGO, proc_tid_children_operations),
3107 #endif
3108 #ifdef CONFIG_NUMA
3109 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3110 #endif
3111 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3112 LNK("cwd", proc_cwd_link),
3113 LNK("root", proc_root_link),
3114 LNK("exe", proc_exe_link),
3115 REG("mounts", S_IRUGO, proc_mounts_operations),
3116 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3117 #ifdef CONFIG_PROC_PAGE_MONITOR
3118 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3119 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3120 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3121 #endif
3122 #ifdef CONFIG_SECURITY
3123 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3124 #endif
3125 #ifdef CONFIG_KALLSYMS
3126 ONE("wchan", S_IRUGO, proc_pid_wchan),
3127 #endif
3128 #ifdef CONFIG_STACKTRACE
3129 ONE("stack", S_IRUSR, proc_pid_stack),
3130 #endif
3131 #ifdef CONFIG_SCHED_INFO
3132 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3133 #endif
3134 #ifdef CONFIG_LATENCYTOP
3135 REG("latency", S_IRUGO, proc_lstats_operations),
3136 #endif
3137 #ifdef CONFIG_PROC_PID_CPUSET
3138 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3139 #endif
3140 #ifdef CONFIG_CGROUPS
3141 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3142 #endif
3143 ONE("oom_score", S_IRUGO, proc_oom_score),
3144 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3145 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3146 #ifdef CONFIG_AUDITSYSCALL
3147 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3148 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3149 #endif
3150 #ifdef CONFIG_FAULT_INJECTION
3151 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3152 #endif
3153 #ifdef CONFIG_TASK_IO_ACCOUNTING
3154 ONE("io", S_IRUSR, proc_tid_io_accounting),
3155 #endif
3156 #ifdef CONFIG_HARDWALL
3157 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3158 #endif
3159 #ifdef CONFIG_USER_NS
3160 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3161 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3162 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3163 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3164 #endif
3165 };
3166
3167 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3168 {
3169 return proc_pident_readdir(file, ctx,
3170 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3171 }
3172
3173 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3174 {
3175 return proc_pident_lookup(dir, dentry,
3176 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3177 }
3178
3179 static const struct file_operations proc_tid_base_operations = {
3180 .read = generic_read_dir,
3181 .iterate = proc_tid_base_readdir,
3182 .llseek = default_llseek,
3183 };
3184
3185 static const struct inode_operations proc_tid_base_inode_operations = {
3186 .lookup = proc_tid_base_lookup,
3187 .getattr = pid_getattr,
3188 .setattr = proc_setattr,
3189 };
3190
3191 static int proc_task_instantiate(struct inode *dir,
3192 struct dentry *dentry, struct task_struct *task, const void *ptr)
3193 {
3194 struct inode *inode;
3195 inode = proc_pid_make_inode(dir->i_sb, task);
3196
3197 if (!inode)
3198 goto out;
3199 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3200 inode->i_op = &proc_tid_base_inode_operations;
3201 inode->i_fop = &proc_tid_base_operations;
3202 inode->i_flags|=S_IMMUTABLE;
3203
3204 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3205 ARRAY_SIZE(tid_base_stuff)));
3206
3207 d_set_d_op(dentry, &pid_dentry_operations);
3208
3209 d_add(dentry, inode);
3210 /* Close the race of the process dying before we return the dentry */
3211 if (pid_revalidate(dentry, 0))
3212 return 0;
3213 out:
3214 return -ENOENT;
3215 }
3216
3217 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3218 {
3219 int result = -ENOENT;
3220 struct task_struct *task;
3221 struct task_struct *leader = get_proc_task(dir);
3222 unsigned tid;
3223 struct pid_namespace *ns;
3224
3225 if (!leader)
3226 goto out_no_task;
3227
3228 tid = name_to_int(&dentry->d_name);
3229 if (tid == ~0U)
3230 goto out;
3231
3232 ns = dentry->d_sb->s_fs_info;
3233 rcu_read_lock();
3234 task = find_task_by_pid_ns(tid, ns);
3235 if (task)
3236 get_task_struct(task);
3237 rcu_read_unlock();
3238 if (!task)
3239 goto out;
3240 if (!same_thread_group(leader, task))
3241 goto out_drop_task;
3242
3243 result = proc_task_instantiate(dir, dentry, task, NULL);
3244 out_drop_task:
3245 put_task_struct(task);
3246 out:
3247 put_task_struct(leader);
3248 out_no_task:
3249 return ERR_PTR(result);
3250 }
3251
3252 /*
3253 * Find the first tid of a thread group to return to user space.
3254 *
3255 * Usually this is just the thread group leader, but if the users
3256 * buffer was too small or there was a seek into the middle of the
3257 * directory we have more work todo.
3258 *
3259 * In the case of a short read we start with find_task_by_pid.
3260 *
3261 * In the case of a seek we start with the leader and walk nr
3262 * threads past it.
3263 */
3264 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3265 struct pid_namespace *ns)
3266 {
3267 struct task_struct *pos, *task;
3268 unsigned long nr = f_pos;
3269
3270 if (nr != f_pos) /* 32bit overflow? */
3271 return NULL;
3272
3273 rcu_read_lock();
3274 task = pid_task(pid, PIDTYPE_PID);
3275 if (!task)
3276 goto fail;
3277
3278 /* Attempt to start with the tid of a thread */
3279 if (tid && nr) {
3280 pos = find_task_by_pid_ns(tid, ns);
3281 if (pos && same_thread_group(pos, task))
3282 goto found;
3283 }
3284
3285 /* If nr exceeds the number of threads there is nothing todo */
3286 if (nr >= get_nr_threads(task))
3287 goto fail;
3288
3289 /* If we haven't found our starting place yet start
3290 * with the leader and walk nr threads forward.
3291 */
3292 pos = task = task->group_leader;
3293 do {
3294 if (!nr--)
3295 goto found;
3296 } while_each_thread(task, pos);
3297 fail:
3298 pos = NULL;
3299 goto out;
3300 found:
3301 get_task_struct(pos);
3302 out:
3303 rcu_read_unlock();
3304 return pos;
3305 }
3306
3307 /*
3308 * Find the next thread in the thread list.
3309 * Return NULL if there is an error or no next thread.
3310 *
3311 * The reference to the input task_struct is released.
3312 */
3313 static struct task_struct *next_tid(struct task_struct *start)
3314 {
3315 struct task_struct *pos = NULL;
3316 rcu_read_lock();
3317 if (pid_alive(start)) {
3318 pos = next_thread(start);
3319 if (thread_group_leader(pos))
3320 pos = NULL;
3321 else
3322 get_task_struct(pos);
3323 }
3324 rcu_read_unlock();
3325 put_task_struct(start);
3326 return pos;
3327 }
3328
3329 /* for the /proc/TGID/task/ directories */
3330 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3331 {
3332 struct inode *inode = file_inode(file);
3333 struct task_struct *task;
3334 struct pid_namespace *ns;
3335 int tid;
3336
3337 if (proc_inode_is_dead(inode))
3338 return -ENOENT;
3339
3340 if (!dir_emit_dots(file, ctx))
3341 return 0;
3342
3343 /* f_version caches the tgid value that the last readdir call couldn't
3344 * return. lseek aka telldir automagically resets f_version to 0.
3345 */
3346 ns = inode->i_sb->s_fs_info;
3347 tid = (int)file->f_version;
3348 file->f_version = 0;
3349 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3350 task;
3351 task = next_tid(task), ctx->pos++) {
3352 char name[PROC_NUMBUF];
3353 int len;
3354 tid = task_pid_nr_ns(task, ns);
3355 len = snprintf(name, sizeof(name), "%d", tid);
3356 if (!proc_fill_cache(file, ctx, name, len,
3357 proc_task_instantiate, task, NULL)) {
3358 /* returning this tgid failed, save it as the first
3359 * pid for the next readir call */
3360 file->f_version = (u64)tid;
3361 put_task_struct(task);
3362 break;
3363 }
3364 }
3365
3366 return 0;
3367 }
3368
3369 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3370 {
3371 struct inode *inode = d_inode(dentry);
3372 struct task_struct *p = get_proc_task(inode);
3373 generic_fillattr(inode, stat);
3374
3375 if (p) {
3376 stat->nlink += get_nr_threads(p);
3377 put_task_struct(p);
3378 }
3379
3380 return 0;
3381 }
3382
3383 static const struct inode_operations proc_task_inode_operations = {
3384 .lookup = proc_task_lookup,
3385 .getattr = proc_task_getattr,
3386 .setattr = proc_setattr,
3387 .permission = proc_pid_permission,
3388 };
3389
3390 static const struct file_operations proc_task_operations = {
3391 .read = generic_read_dir,
3392 .iterate = proc_task_readdir,
3393 .llseek = default_llseek,
3394 };
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