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