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Staging: fbtft: fb_ssd1331: Remove unnecessary cast
[linux/fpc-iii.git] / fs / proc / base.c
blobb25eee4cead5398b69889c95c29480ba9862c397
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 uid_t loginuid;
1234 kuid_t kloginuid;
1235 int rv;
1236
1237 rcu_read_lock();
1238 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1239 rcu_read_unlock();
1240 return -EPERM;
1241 }
1242 rcu_read_unlock();
1243
1244 if (*ppos != 0) {
1245 /* No partial writes. */
1246 return -EINVAL;
1247 }
1248
1249 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1250 if (rv < 0)
1251 return rv;
1252
1253 /* is userspace tring to explicitly UNSET the loginuid? */
1254 if (loginuid == AUDIT_UID_UNSET) {
1255 kloginuid = INVALID_UID;
1256 } else {
1257 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1258 if (!uid_valid(kloginuid))
1259 return -EINVAL;
1260 }
1261
1262 rv = audit_set_loginuid(kloginuid);
1263 if (rv < 0)
1264 return rv;
1265 return count;
1266 }
1267
1268 static const struct file_operations proc_loginuid_operations = {
1269 .read = proc_loginuid_read,
1270 .write = proc_loginuid_write,
1271 .llseek = generic_file_llseek,
1272 };
1273
1274 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1275 size_t count, loff_t *ppos)
1276 {
1277 struct inode * inode = file_inode(file);
1278 struct task_struct *task = get_proc_task(inode);
1279 ssize_t length;
1280 char tmpbuf[TMPBUFLEN];
1281
1282 if (!task)
1283 return -ESRCH;
1284 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1285 audit_get_sessionid(task));
1286 put_task_struct(task);
1287 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1288 }
1289
1290 static const struct file_operations proc_sessionid_operations = {
1291 .read = proc_sessionid_read,
1292 .llseek = generic_file_llseek,
1293 };
1294 #endif
1295
1296 #ifdef CONFIG_FAULT_INJECTION
1297 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1298 size_t count, loff_t *ppos)
1299 {
1300 struct task_struct *task = get_proc_task(file_inode(file));
1301 char buffer[PROC_NUMBUF];
1302 size_t len;
1303 int make_it_fail;
1304
1305 if (!task)
1306 return -ESRCH;
1307 make_it_fail = task->make_it_fail;
1308 put_task_struct(task);
1309
1310 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1311
1312 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1313 }
1314
1315 static ssize_t proc_fault_inject_write(struct file * file,
1316 const char __user * buf, size_t count, loff_t *ppos)
1317 {
1318 struct task_struct *task;
1319 char buffer[PROC_NUMBUF];
1320 int make_it_fail;
1321 int rv;
1322
1323 if (!capable(CAP_SYS_RESOURCE))
1324 return -EPERM;
1325 memset(buffer, 0, sizeof(buffer));
1326 if (count > sizeof(buffer) - 1)
1327 count = sizeof(buffer) - 1;
1328 if (copy_from_user(buffer, buf, count))
1329 return -EFAULT;
1330 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1331 if (rv < 0)
1332 return rv;
1333 if (make_it_fail < 0 || make_it_fail > 1)
1334 return -EINVAL;
1335
1336 task = get_proc_task(file_inode(file));
1337 if (!task)
1338 return -ESRCH;
1339 task->make_it_fail = make_it_fail;
1340 put_task_struct(task);
1341
1342 return count;
1343 }
1344
1345 static const struct file_operations proc_fault_inject_operations = {
1346 .read = proc_fault_inject_read,
1347 .write = proc_fault_inject_write,
1348 .llseek = generic_file_llseek,
1349 };
1350 #endif
1351
1352
1353 #ifdef CONFIG_SCHED_DEBUG
1354 /*
1355 * Print out various scheduling related per-task fields:
1356 */
1357 static int sched_show(struct seq_file *m, void *v)
1358 {
1359 struct inode *inode = m->private;
1360 struct task_struct *p;
1361
1362 p = get_proc_task(inode);
1363 if (!p)
1364 return -ESRCH;
1365 proc_sched_show_task(p, m);
1366
1367 put_task_struct(p);
1368
1369 return 0;
1370 }
1371
1372 static ssize_t
1373 sched_write(struct file *file, const char __user *buf,
1374 size_t count, loff_t *offset)
1375 {
1376 struct inode *inode = file_inode(file);
1377 struct task_struct *p;
1378
1379 p = get_proc_task(inode);
1380 if (!p)
1381 return -ESRCH;
1382 proc_sched_set_task(p);
1383
1384 put_task_struct(p);
1385
1386 return count;
1387 }
1388
1389 static int sched_open(struct inode *inode, struct file *filp)
1390 {
1391 return single_open(filp, sched_show, inode);
1392 }
1393
1394 static const struct file_operations proc_pid_sched_operations = {
1395 .open = sched_open,
1396 .read = seq_read,
1397 .write = sched_write,
1398 .llseek = seq_lseek,
1399 .release = single_release,
1400 };
1401
1402 #endif
1403
1404 #ifdef CONFIG_SCHED_AUTOGROUP
1405 /*
1406 * Print out autogroup related information:
1407 */
1408 static int sched_autogroup_show(struct seq_file *m, void *v)
1409 {
1410 struct inode *inode = m->private;
1411 struct task_struct *p;
1412
1413 p = get_proc_task(inode);
1414 if (!p)
1415 return -ESRCH;
1416 proc_sched_autogroup_show_task(p, m);
1417
1418 put_task_struct(p);
1419
1420 return 0;
1421 }
1422
1423 static ssize_t
1424 sched_autogroup_write(struct file *file, const char __user *buf,
1425 size_t count, loff_t *offset)
1426 {
1427 struct inode *inode = file_inode(file);
1428 struct task_struct *p;
1429 char buffer[PROC_NUMBUF];
1430 int nice;
1431 int err;
1432
1433 memset(buffer, 0, sizeof(buffer));
1434 if (count > sizeof(buffer) - 1)
1435 count = sizeof(buffer) - 1;
1436 if (copy_from_user(buffer, buf, count))
1437 return -EFAULT;
1438
1439 err = kstrtoint(strstrip(buffer), 0, &nice);
1440 if (err < 0)
1441 return err;
1442
1443 p = get_proc_task(inode);
1444 if (!p)
1445 return -ESRCH;
1446
1447 err = proc_sched_autogroup_set_nice(p, nice);
1448 if (err)
1449 count = err;
1450
1451 put_task_struct(p);
1452
1453 return count;
1454 }
1455
1456 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1457 {
1458 int ret;
1459
1460 ret = single_open(filp, sched_autogroup_show, NULL);
1461 if (!ret) {
1462 struct seq_file *m = filp->private_data;
1463
1464 m->private = inode;
1465 }
1466 return ret;
1467 }
1468
1469 static const struct file_operations proc_pid_sched_autogroup_operations = {
1470 .open = sched_autogroup_open,
1471 .read = seq_read,
1472 .write = sched_autogroup_write,
1473 .llseek = seq_lseek,
1474 .release = single_release,
1475 };
1476
1477 #endif /* CONFIG_SCHED_AUTOGROUP */
1478
1479 static ssize_t comm_write(struct file *file, const char __user *buf,
1480 size_t count, loff_t *offset)
1481 {
1482 struct inode *inode = file_inode(file);
1483 struct task_struct *p;
1484 char buffer[TASK_COMM_LEN];
1485 const size_t maxlen = sizeof(buffer) - 1;
1486
1487 memset(buffer, 0, sizeof(buffer));
1488 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1489 return -EFAULT;
1490
1491 p = get_proc_task(inode);
1492 if (!p)
1493 return -ESRCH;
1494
1495 if (same_thread_group(current, p))
1496 set_task_comm(p, buffer);
1497 else
1498 count = -EINVAL;
1499
1500 put_task_struct(p);
1501
1502 return count;
1503 }
1504
1505 static int comm_show(struct seq_file *m, void *v)
1506 {
1507 struct inode *inode = m->private;
1508 struct task_struct *p;
1509
1510 p = get_proc_task(inode);
1511 if (!p)
1512 return -ESRCH;
1513
1514 task_lock(p);
1515 seq_printf(m, "%s\n", p->comm);
1516 task_unlock(p);
1517
1518 put_task_struct(p);
1519
1520 return 0;
1521 }
1522
1523 static int comm_open(struct inode *inode, struct file *filp)
1524 {
1525 return single_open(filp, comm_show, inode);
1526 }
1527
1528 static const struct file_operations proc_pid_set_comm_operations = {
1529 .open = comm_open,
1530 .read = seq_read,
1531 .write = comm_write,
1532 .llseek = seq_lseek,
1533 .release = single_release,
1534 };
1535
1536 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1537 {
1538 struct task_struct *task;
1539 struct mm_struct *mm;
1540 struct file *exe_file;
1541
1542 task = get_proc_task(d_inode(dentry));
1543 if (!task)
1544 return -ENOENT;
1545 mm = get_task_mm(task);
1546 put_task_struct(task);
1547 if (!mm)
1548 return -ENOENT;
1549 exe_file = get_mm_exe_file(mm);
1550 mmput(mm);
1551 if (exe_file) {
1552 *exe_path = exe_file->f_path;
1553 path_get(&exe_file->f_path);
1554 fput(exe_file);
1555 return 0;
1556 } else
1557 return -ENOENT;
1558 }
1559
1560 static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
1561 {
1562 struct inode *inode = d_inode(dentry);
1563 struct path path;
1564 int error = -EACCES;
1565
1566 /* Are we allowed to snoop on the tasks file descriptors? */
1567 if (!proc_fd_access_allowed(inode))
1568 goto out;
1569
1570 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1571 if (error)
1572 goto out;
1573
1574 nd_jump_link(&path);
1575 return NULL;
1576 out:
1577 return ERR_PTR(error);
1578 }
1579
1580 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1581 {
1582 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1583 char *pathname;
1584 int len;
1585
1586 if (!tmp)
1587 return -ENOMEM;
1588
1589 pathname = d_path(path, tmp, PAGE_SIZE);
1590 len = PTR_ERR(pathname);
1591 if (IS_ERR(pathname))
1592 goto out;
1593 len = tmp + PAGE_SIZE - 1 - pathname;
1594
1595 if (len > buflen)
1596 len = buflen;
1597 if (copy_to_user(buffer, pathname, len))
1598 len = -EFAULT;
1599 out:
1600 free_page((unsigned long)tmp);
1601 return len;
1602 }
1603
1604 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1605 {
1606 int error = -EACCES;
1607 struct inode *inode = d_inode(dentry);
1608 struct path path;
1609
1610 /* Are we allowed to snoop on the tasks file descriptors? */
1611 if (!proc_fd_access_allowed(inode))
1612 goto out;
1613
1614 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1615 if (error)
1616 goto out;
1617
1618 error = do_proc_readlink(&path, buffer, buflen);
1619 path_put(&path);
1620 out:
1621 return error;
1622 }
1623
1624 const struct inode_operations proc_pid_link_inode_operations = {
1625 .readlink = proc_pid_readlink,
1626 .follow_link = proc_pid_follow_link,
1627 .setattr = proc_setattr,
1628 };
1629
1630
1631 /* building an inode */
1632
1633 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1634 {
1635 struct inode * inode;
1636 struct proc_inode *ei;
1637 const struct cred *cred;
1638
1639 /* We need a new inode */
1640
1641 inode = new_inode(sb);
1642 if (!inode)
1643 goto out;
1644
1645 /* Common stuff */
1646 ei = PROC_I(inode);
1647 inode->i_ino = get_next_ino();
1648 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1649 inode->i_op = &proc_def_inode_operations;
1650
1651 /*
1652 * grab the reference to task.
1653 */
1654 ei->pid = get_task_pid(task, PIDTYPE_PID);
1655 if (!ei->pid)
1656 goto out_unlock;
1657
1658 if (task_dumpable(task)) {
1659 rcu_read_lock();
1660 cred = __task_cred(task);
1661 inode->i_uid = cred->euid;
1662 inode->i_gid = cred->egid;
1663 rcu_read_unlock();
1664 }
1665 security_task_to_inode(task, inode);
1666
1667 out:
1668 return inode;
1669
1670 out_unlock:
1671 iput(inode);
1672 return NULL;
1673 }
1674
1675 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1676 {
1677 struct inode *inode = d_inode(dentry);
1678 struct task_struct *task;
1679 const struct cred *cred;
1680 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1681
1682 generic_fillattr(inode, stat);
1683
1684 rcu_read_lock();
1685 stat->uid = GLOBAL_ROOT_UID;
1686 stat->gid = GLOBAL_ROOT_GID;
1687 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1688 if (task) {
1689 if (!has_pid_permissions(pid, task, 2)) {
1690 rcu_read_unlock();
1691 /*
1692 * This doesn't prevent learning whether PID exists,
1693 * it only makes getattr() consistent with readdir().
1694 */
1695 return -ENOENT;
1696 }
1697 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1698 task_dumpable(task)) {
1699 cred = __task_cred(task);
1700 stat->uid = cred->euid;
1701 stat->gid = cred->egid;
1702 }
1703 }
1704 rcu_read_unlock();
1705 return 0;
1706 }
1707
1708 /* dentry stuff */
1709
1710 /*
1711 * Exceptional case: normally we are not allowed to unhash a busy
1712 * directory. In this case, however, we can do it - no aliasing problems
1713 * due to the way we treat inodes.
1714 *
1715 * Rewrite the inode's ownerships here because the owning task may have
1716 * performed a setuid(), etc.
1717 *
1718 * Before the /proc/pid/status file was created the only way to read
1719 * the effective uid of a /process was to stat /proc/pid. Reading
1720 * /proc/pid/status is slow enough that procps and other packages
1721 * kept stating /proc/pid. To keep the rules in /proc simple I have
1722 * made this apply to all per process world readable and executable
1723 * directories.
1724 */
1725 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1726 {
1727 struct inode *inode;
1728 struct task_struct *task;
1729 const struct cred *cred;
1730
1731 if (flags & LOOKUP_RCU)
1732 return -ECHILD;
1733
1734 inode = d_inode(dentry);
1735 task = get_proc_task(inode);
1736
1737 if (task) {
1738 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1739 task_dumpable(task)) {
1740 rcu_read_lock();
1741 cred = __task_cred(task);
1742 inode->i_uid = cred->euid;
1743 inode->i_gid = cred->egid;
1744 rcu_read_unlock();
1745 } else {
1746 inode->i_uid = GLOBAL_ROOT_UID;
1747 inode->i_gid = GLOBAL_ROOT_GID;
1748 }
1749 inode->i_mode &= ~(S_ISUID | S_ISGID);
1750 security_task_to_inode(task, inode);
1751 put_task_struct(task);
1752 return 1;
1753 }
1754 return 0;
1755 }
1756
1757 static inline bool proc_inode_is_dead(struct inode *inode)
1758 {
1759 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1760 }
1761
1762 int pid_delete_dentry(const struct dentry *dentry)
1763 {
1764 /* Is the task we represent dead?
1765 * If so, then don't put the dentry on the lru list,
1766 * kill it immediately.
1767 */
1768 return proc_inode_is_dead(d_inode(dentry));
1769 }
1770
1771 const struct dentry_operations pid_dentry_operations =
1772 {
1773 .d_revalidate = pid_revalidate,
1774 .d_delete = pid_delete_dentry,
1775 };
1776
1777 /* Lookups */
1778
1779 /*
1780 * Fill a directory entry.
1781 *
1782 * If possible create the dcache entry and derive our inode number and
1783 * file type from dcache entry.
1784 *
1785 * Since all of the proc inode numbers are dynamically generated, the inode
1786 * numbers do not exist until the inode is cache. This means creating the
1787 * the dcache entry in readdir is necessary to keep the inode numbers
1788 * reported by readdir in sync with the inode numbers reported
1789 * by stat.
1790 */
1791 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1792 const char *name, int len,
1793 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1794 {
1795 struct dentry *child, *dir = file->f_path.dentry;
1796 struct qstr qname = QSTR_INIT(name, len);
1797 struct inode *inode;
1798 unsigned type;
1799 ino_t ino;
1800
1801 child = d_hash_and_lookup(dir, &qname);
1802 if (!child) {
1803 child = d_alloc(dir, &qname);
1804 if (!child)
1805 goto end_instantiate;
1806 if (instantiate(d_inode(dir), child, task, ptr) < 0) {
1807 dput(child);
1808 goto end_instantiate;
1809 }
1810 }
1811 inode = d_inode(child);
1812 ino = inode->i_ino;
1813 type = inode->i_mode >> 12;
1814 dput(child);
1815 return dir_emit(ctx, name, len, ino, type);
1816
1817 end_instantiate:
1818 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1819 }
1820
1821 /*
1822 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1823 * which represent vma start and end addresses.
1824 */
1825 static int dname_to_vma_addr(struct dentry *dentry,
1826 unsigned long *start, unsigned long *end)
1827 {
1828 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1829 return -EINVAL;
1830
1831 return 0;
1832 }
1833
1834 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1835 {
1836 unsigned long vm_start, vm_end;
1837 bool exact_vma_exists = false;
1838 struct mm_struct *mm = NULL;
1839 struct task_struct *task;
1840 const struct cred *cred;
1841 struct inode *inode;
1842 int status = 0;
1843
1844 if (flags & LOOKUP_RCU)
1845 return -ECHILD;
1846
1847 inode = d_inode(dentry);
1848 task = get_proc_task(inode);
1849 if (!task)
1850 goto out_notask;
1851
1852 mm = mm_access(task, PTRACE_MODE_READ);
1853 if (IS_ERR_OR_NULL(mm))
1854 goto out;
1855
1856 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1857 down_read(&mm->mmap_sem);
1858 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1859 up_read(&mm->mmap_sem);
1860 }
1861
1862 mmput(mm);
1863
1864 if (exact_vma_exists) {
1865 if (task_dumpable(task)) {
1866 rcu_read_lock();
1867 cred = __task_cred(task);
1868 inode->i_uid = cred->euid;
1869 inode->i_gid = cred->egid;
1870 rcu_read_unlock();
1871 } else {
1872 inode->i_uid = GLOBAL_ROOT_UID;
1873 inode->i_gid = GLOBAL_ROOT_GID;
1874 }
1875 security_task_to_inode(task, inode);
1876 status = 1;
1877 }
1878
1879 out:
1880 put_task_struct(task);
1881
1882 out_notask:
1883 return status;
1884 }
1885
1886 static const struct dentry_operations tid_map_files_dentry_operations = {
1887 .d_revalidate = map_files_d_revalidate,
1888 .d_delete = pid_delete_dentry,
1889 };
1890
1891 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1892 {
1893 unsigned long vm_start, vm_end;
1894 struct vm_area_struct *vma;
1895 struct task_struct *task;
1896 struct mm_struct *mm;
1897 int rc;
1898
1899 rc = -ENOENT;
1900 task = get_proc_task(d_inode(dentry));
1901 if (!task)
1902 goto out;
1903
1904 mm = get_task_mm(task);
1905 put_task_struct(task);
1906 if (!mm)
1907 goto out;
1908
1909 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1910 if (rc)
1911 goto out_mmput;
1912
1913 rc = -ENOENT;
1914 down_read(&mm->mmap_sem);
1915 vma = find_exact_vma(mm, vm_start, vm_end);
1916 if (vma && vma->vm_file) {
1917 *path = vma->vm_file->f_path;
1918 path_get(path);
1919 rc = 0;
1920 }
1921 up_read(&mm->mmap_sem);
1922
1923 out_mmput:
1924 mmput(mm);
1925 out:
1926 return rc;
1927 }
1928
1929 struct map_files_info {
1930 fmode_t mode;
1931 unsigned long len;
1932 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1933 };
1934
1935 /*
1936 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1937 * symlinks may be used to bypass permissions on ancestor directories in the
1938 * path to the file in question.
1939 */
1940 static const char *
1941 proc_map_files_follow_link(struct dentry *dentry, void **cookie)
1942 {
1943 if (!capable(CAP_SYS_ADMIN))
1944 return ERR_PTR(-EPERM);
1945
1946 return proc_pid_follow_link(dentry, NULL);
1947 }
1948
1949 /*
1950 * Identical to proc_pid_link_inode_operations except for follow_link()
1951 */
1952 static const struct inode_operations proc_map_files_link_inode_operations = {
1953 .readlink = proc_pid_readlink,
1954 .follow_link = proc_map_files_follow_link,
1955 .setattr = proc_setattr,
1956 };
1957
1958 static int
1959 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1960 struct task_struct *task, const void *ptr)
1961 {
1962 fmode_t mode = (fmode_t)(unsigned long)ptr;
1963 struct proc_inode *ei;
1964 struct inode *inode;
1965
1966 inode = proc_pid_make_inode(dir->i_sb, task);
1967 if (!inode)
1968 return -ENOENT;
1969
1970 ei = PROC_I(inode);
1971 ei->op.proc_get_link = proc_map_files_get_link;
1972
1973 inode->i_op = &proc_map_files_link_inode_operations;
1974 inode->i_size = 64;
1975 inode->i_mode = S_IFLNK;
1976
1977 if (mode & FMODE_READ)
1978 inode->i_mode |= S_IRUSR;
1979 if (mode & FMODE_WRITE)
1980 inode->i_mode |= S_IWUSR;
1981
1982 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1983 d_add(dentry, inode);
1984
1985 return 0;
1986 }
1987
1988 static struct dentry *proc_map_files_lookup(struct inode *dir,
1989 struct dentry *dentry, unsigned int flags)
1990 {
1991 unsigned long vm_start, vm_end;
1992 struct vm_area_struct *vma;
1993 struct task_struct *task;
1994 int result;
1995 struct mm_struct *mm;
1996
1997 result = -ENOENT;
1998 task = get_proc_task(dir);
1999 if (!task)
2000 goto out;
2001
2002 result = -EACCES;
2003 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2004 goto out_put_task;
2005
2006 result = -ENOENT;
2007 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2008 goto out_put_task;
2009
2010 mm = get_task_mm(task);
2011 if (!mm)
2012 goto out_put_task;
2013
2014 down_read(&mm->mmap_sem);
2015 vma = find_exact_vma(mm, vm_start, vm_end);
2016 if (!vma)
2017 goto out_no_vma;
2018
2019 if (vma->vm_file)
2020 result = proc_map_files_instantiate(dir, dentry, task,
2021 (void *)(unsigned long)vma->vm_file->f_mode);
2022
2023 out_no_vma:
2024 up_read(&mm->mmap_sem);
2025 mmput(mm);
2026 out_put_task:
2027 put_task_struct(task);
2028 out:
2029 return ERR_PTR(result);
2030 }
2031
2032 static const struct inode_operations proc_map_files_inode_operations = {
2033 .lookup = proc_map_files_lookup,
2034 .permission = proc_fd_permission,
2035 .setattr = proc_setattr,
2036 };
2037
2038 static int
2039 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2040 {
2041 struct vm_area_struct *vma;
2042 struct task_struct *task;
2043 struct mm_struct *mm;
2044 unsigned long nr_files, pos, i;
2045 struct flex_array *fa = NULL;
2046 struct map_files_info info;
2047 struct map_files_info *p;
2048 int ret;
2049
2050 ret = -ENOENT;
2051 task = get_proc_task(file_inode(file));
2052 if (!task)
2053 goto out;
2054
2055 ret = -EACCES;
2056 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2057 goto out_put_task;
2058
2059 ret = 0;
2060 if (!dir_emit_dots(file, ctx))
2061 goto out_put_task;
2062
2063 mm = get_task_mm(task);
2064 if (!mm)
2065 goto out_put_task;
2066 down_read(&mm->mmap_sem);
2067
2068 nr_files = 0;
2069
2070 /*
2071 * We need two passes here:
2072 *
2073 * 1) Collect vmas of mapped files with mmap_sem taken
2074 * 2) Release mmap_sem and instantiate entries
2075 *
2076 * otherwise we get lockdep complained, since filldir()
2077 * routine might require mmap_sem taken in might_fault().
2078 */
2079
2080 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2081 if (vma->vm_file && ++pos > ctx->pos)
2082 nr_files++;
2083 }
2084
2085 if (nr_files) {
2086 fa = flex_array_alloc(sizeof(info), nr_files,
2087 GFP_KERNEL);
2088 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2089 GFP_KERNEL)) {
2090 ret = -ENOMEM;
2091 if (fa)
2092 flex_array_free(fa);
2093 up_read(&mm->mmap_sem);
2094 mmput(mm);
2095 goto out_put_task;
2096 }
2097 for (i = 0, vma = mm->mmap, pos = 2; vma;
2098 vma = vma->vm_next) {
2099 if (!vma->vm_file)
2100 continue;
2101 if (++pos <= ctx->pos)
2102 continue;
2103
2104 info.mode = vma->vm_file->f_mode;
2105 info.len = snprintf(info.name,
2106 sizeof(info.name), "%lx-%lx",
2107 vma->vm_start, vma->vm_end);
2108 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2109 BUG();
2110 }
2111 }
2112 up_read(&mm->mmap_sem);
2113
2114 for (i = 0; i < nr_files; i++) {
2115 p = flex_array_get(fa, i);
2116 if (!proc_fill_cache(file, ctx,
2117 p->name, p->len,
2118 proc_map_files_instantiate,
2119 task,
2120 (void *)(unsigned long)p->mode))
2121 break;
2122 ctx->pos++;
2123 }
2124 if (fa)
2125 flex_array_free(fa);
2126 mmput(mm);
2127
2128 out_put_task:
2129 put_task_struct(task);
2130 out:
2131 return ret;
2132 }
2133
2134 static const struct file_operations proc_map_files_operations = {
2135 .read = generic_read_dir,
2136 .iterate = proc_map_files_readdir,
2137 .llseek = default_llseek,
2138 };
2139
2140 struct timers_private {
2141 struct pid *pid;
2142 struct task_struct *task;
2143 struct sighand_struct *sighand;
2144 struct pid_namespace *ns;
2145 unsigned long flags;
2146 };
2147
2148 static void *timers_start(struct seq_file *m, loff_t *pos)
2149 {
2150 struct timers_private *tp = m->private;
2151
2152 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2153 if (!tp->task)
2154 return ERR_PTR(-ESRCH);
2155
2156 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2157 if (!tp->sighand)
2158 return ERR_PTR(-ESRCH);
2159
2160 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2161 }
2162
2163 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2164 {
2165 struct timers_private *tp = m->private;
2166 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2167 }
2168
2169 static void timers_stop(struct seq_file *m, void *v)
2170 {
2171 struct timers_private *tp = m->private;
2172
2173 if (tp->sighand) {
2174 unlock_task_sighand(tp->task, &tp->flags);
2175 tp->sighand = NULL;
2176 }
2177
2178 if (tp->task) {
2179 put_task_struct(tp->task);
2180 tp->task = NULL;
2181 }
2182 }
2183
2184 static int show_timer(struct seq_file *m, void *v)
2185 {
2186 struct k_itimer *timer;
2187 struct timers_private *tp = m->private;
2188 int notify;
2189 static const char * const nstr[] = {
2190 [SIGEV_SIGNAL] = "signal",
2191 [SIGEV_NONE] = "none",
2192 [SIGEV_THREAD] = "thread",
2193 };
2194
2195 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2196 notify = timer->it_sigev_notify;
2197
2198 seq_printf(m, "ID: %d\n", timer->it_id);
2199 seq_printf(m, "signal: %d/%p\n",
2200 timer->sigq->info.si_signo,
2201 timer->sigq->info.si_value.sival_ptr);
2202 seq_printf(m, "notify: %s/%s.%d\n",
2203 nstr[notify & ~SIGEV_THREAD_ID],
2204 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2205 pid_nr_ns(timer->it_pid, tp->ns));
2206 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2207
2208 return 0;
2209 }
2210
2211 static const struct seq_operations proc_timers_seq_ops = {
2212 .start = timers_start,
2213 .next = timers_next,
2214 .stop = timers_stop,
2215 .show = show_timer,
2216 };
2217
2218 static int proc_timers_open(struct inode *inode, struct file *file)
2219 {
2220 struct timers_private *tp;
2221
2222 tp = __seq_open_private(file, &proc_timers_seq_ops,
2223 sizeof(struct timers_private));
2224 if (!tp)
2225 return -ENOMEM;
2226
2227 tp->pid = proc_pid(inode);
2228 tp->ns = inode->i_sb->s_fs_info;
2229 return 0;
2230 }
2231
2232 static const struct file_operations proc_timers_operations = {
2233 .open = proc_timers_open,
2234 .read = seq_read,
2235 .llseek = seq_lseek,
2236 .release = seq_release_private,
2237 };
2238
2239 static int proc_pident_instantiate(struct inode *dir,
2240 struct dentry *dentry, struct task_struct *task, const void *ptr)
2241 {
2242 const struct pid_entry *p = ptr;
2243 struct inode *inode;
2244 struct proc_inode *ei;
2245
2246 inode = proc_pid_make_inode(dir->i_sb, task);
2247 if (!inode)
2248 goto out;
2249
2250 ei = PROC_I(inode);
2251 inode->i_mode = p->mode;
2252 if (S_ISDIR(inode->i_mode))
2253 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2254 if (p->iop)
2255 inode->i_op = p->iop;
2256 if (p->fop)
2257 inode->i_fop = p->fop;
2258 ei->op = p->op;
2259 d_set_d_op(dentry, &pid_dentry_operations);
2260 d_add(dentry, inode);
2261 /* Close the race of the process dying before we return the dentry */
2262 if (pid_revalidate(dentry, 0))
2263 return 0;
2264 out:
2265 return -ENOENT;
2266 }
2267
2268 static struct dentry *proc_pident_lookup(struct inode *dir,
2269 struct dentry *dentry,
2270 const struct pid_entry *ents,
2271 unsigned int nents)
2272 {
2273 int error;
2274 struct task_struct *task = get_proc_task(dir);
2275 const struct pid_entry *p, *last;
2276
2277 error = -ENOENT;
2278
2279 if (!task)
2280 goto out_no_task;
2281
2282 /*
2283 * Yes, it does not scale. And it should not. Don't add
2284 * new entries into /proc/<tgid>/ without very good reasons.
2285 */
2286 last = &ents[nents - 1];
2287 for (p = ents; p <= last; p++) {
2288 if (p->len != dentry->d_name.len)
2289 continue;
2290 if (!memcmp(dentry->d_name.name, p->name, p->len))
2291 break;
2292 }
2293 if (p > last)
2294 goto out;
2295
2296 error = proc_pident_instantiate(dir, dentry, task, p);
2297 out:
2298 put_task_struct(task);
2299 out_no_task:
2300 return ERR_PTR(error);
2301 }
2302
2303 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2304 const struct pid_entry *ents, unsigned int nents)
2305 {
2306 struct task_struct *task = get_proc_task(file_inode(file));
2307 const struct pid_entry *p;
2308
2309 if (!task)
2310 return -ENOENT;
2311
2312 if (!dir_emit_dots(file, ctx))
2313 goto out;
2314
2315 if (ctx->pos >= nents + 2)
2316 goto out;
2317
2318 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2319 if (!proc_fill_cache(file, ctx, p->name, p->len,
2320 proc_pident_instantiate, task, p))
2321 break;
2322 ctx->pos++;
2323 }
2324 out:
2325 put_task_struct(task);
2326 return 0;
2327 }
2328
2329 #ifdef CONFIG_SECURITY
2330 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2331 size_t count, loff_t *ppos)
2332 {
2333 struct inode * inode = file_inode(file);
2334 char *p = NULL;
2335 ssize_t length;
2336 struct task_struct *task = get_proc_task(inode);
2337
2338 if (!task)
2339 return -ESRCH;
2340
2341 length = security_getprocattr(task,
2342 (char*)file->f_path.dentry->d_name.name,
2343 &p);
2344 put_task_struct(task);
2345 if (length > 0)
2346 length = simple_read_from_buffer(buf, count, ppos, p, length);
2347 kfree(p);
2348 return length;
2349 }
2350
2351 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2352 size_t count, loff_t *ppos)
2353 {
2354 struct inode * inode = file_inode(file);
2355 char *page;
2356 ssize_t length;
2357 struct task_struct *task = get_proc_task(inode);
2358
2359 length = -ESRCH;
2360 if (!task)
2361 goto out_no_task;
2362 if (count > PAGE_SIZE)
2363 count = PAGE_SIZE;
2364
2365 /* No partial writes. */
2366 length = -EINVAL;
2367 if (*ppos != 0)
2368 goto out;
2369
2370 length = -ENOMEM;
2371 page = (char*)__get_free_page(GFP_TEMPORARY);
2372 if (!page)
2373 goto out;
2374
2375 length = -EFAULT;
2376 if (copy_from_user(page, buf, count))
2377 goto out_free;
2378
2379 /* Guard against adverse ptrace interaction */
2380 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2381 if (length < 0)
2382 goto out_free;
2383
2384 length = security_setprocattr(task,
2385 (char*)file->f_path.dentry->d_name.name,
2386 (void*)page, count);
2387 mutex_unlock(&task->signal->cred_guard_mutex);
2388 out_free:
2389 free_page((unsigned long) page);
2390 out:
2391 put_task_struct(task);
2392 out_no_task:
2393 return length;
2394 }
2395
2396 static const struct file_operations proc_pid_attr_operations = {
2397 .read = proc_pid_attr_read,
2398 .write = proc_pid_attr_write,
2399 .llseek = generic_file_llseek,
2400 };
2401
2402 static const struct pid_entry attr_dir_stuff[] = {
2403 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2404 REG("prev", S_IRUGO, proc_pid_attr_operations),
2405 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2406 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2407 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2408 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2409 };
2410
2411 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2412 {
2413 return proc_pident_readdir(file, ctx,
2414 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2415 }
2416
2417 static const struct file_operations proc_attr_dir_operations = {
2418 .read = generic_read_dir,
2419 .iterate = proc_attr_dir_readdir,
2420 .llseek = default_llseek,
2421 };
2422
2423 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2424 struct dentry *dentry, unsigned int flags)
2425 {
2426 return proc_pident_lookup(dir, dentry,
2427 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2428 }
2429
2430 static const struct inode_operations proc_attr_dir_inode_operations = {
2431 .lookup = proc_attr_dir_lookup,
2432 .getattr = pid_getattr,
2433 .setattr = proc_setattr,
2434 };
2435
2436 #endif
2437
2438 #ifdef CONFIG_ELF_CORE
2439 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2440 size_t count, loff_t *ppos)
2441 {
2442 struct task_struct *task = get_proc_task(file_inode(file));
2443 struct mm_struct *mm;
2444 char buffer[PROC_NUMBUF];
2445 size_t len;
2446 int ret;
2447
2448 if (!task)
2449 return -ESRCH;
2450
2451 ret = 0;
2452 mm = get_task_mm(task);
2453 if (mm) {
2454 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2455 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2456 MMF_DUMP_FILTER_SHIFT));
2457 mmput(mm);
2458 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2459 }
2460
2461 put_task_struct(task);
2462
2463 return ret;
2464 }
2465
2466 static ssize_t proc_coredump_filter_write(struct file *file,
2467 const char __user *buf,
2468 size_t count,
2469 loff_t *ppos)
2470 {
2471 struct task_struct *task;
2472 struct mm_struct *mm;
2473 unsigned int val;
2474 int ret;
2475 int i;
2476 unsigned long mask;
2477
2478 ret = kstrtouint_from_user(buf, count, 0, &val);
2479 if (ret < 0)
2480 return ret;
2481
2482 ret = -ESRCH;
2483 task = get_proc_task(file_inode(file));
2484 if (!task)
2485 goto out_no_task;
2486
2487 mm = get_task_mm(task);
2488 if (!mm)
2489 goto out_no_mm;
2490
2491 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2492 if (val & mask)
2493 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2494 else
2495 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2496 }
2497
2498 mmput(mm);
2499 out_no_mm:
2500 put_task_struct(task);
2501 out_no_task:
2502 if (ret < 0)
2503 return ret;
2504 return count;
2505 }
2506
2507 static const struct file_operations proc_coredump_filter_operations = {
2508 .read = proc_coredump_filter_read,
2509 .write = proc_coredump_filter_write,
2510 .llseek = generic_file_llseek,
2511 };
2512 #endif
2513
2514 #ifdef CONFIG_TASK_IO_ACCOUNTING
2515 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2516 {
2517 struct task_io_accounting acct = task->ioac;
2518 unsigned long flags;
2519 int result;
2520
2521 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2522 if (result)
2523 return result;
2524
2525 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2526 result = -EACCES;
2527 goto out_unlock;
2528 }
2529
2530 if (whole && lock_task_sighand(task, &flags)) {
2531 struct task_struct *t = task;
2532
2533 task_io_accounting_add(&acct, &task->signal->ioac);
2534 while_each_thread(task, t)
2535 task_io_accounting_add(&acct, &t->ioac);
2536
2537 unlock_task_sighand(task, &flags);
2538 }
2539 seq_printf(m,
2540 "rchar: %llu\n"
2541 "wchar: %llu\n"
2542 "syscr: %llu\n"
2543 "syscw: %llu\n"
2544 "read_bytes: %llu\n"
2545 "write_bytes: %llu\n"
2546 "cancelled_write_bytes: %llu\n",
2547 (unsigned long long)acct.rchar,
2548 (unsigned long long)acct.wchar,
2549 (unsigned long long)acct.syscr,
2550 (unsigned long long)acct.syscw,
2551 (unsigned long long)acct.read_bytes,
2552 (unsigned long long)acct.write_bytes,
2553 (unsigned long long)acct.cancelled_write_bytes);
2554 result = 0;
2555
2556 out_unlock:
2557 mutex_unlock(&task->signal->cred_guard_mutex);
2558 return result;
2559 }
2560
2561 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2562 struct pid *pid, struct task_struct *task)
2563 {
2564 return do_io_accounting(task, m, 0);
2565 }
2566
2567 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2568 struct pid *pid, struct task_struct *task)
2569 {
2570 return do_io_accounting(task, m, 1);
2571 }
2572 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2573
2574 #ifdef CONFIG_USER_NS
2575 static int proc_id_map_open(struct inode *inode, struct file *file,
2576 const struct seq_operations *seq_ops)
2577 {
2578 struct user_namespace *ns = NULL;
2579 struct task_struct *task;
2580 struct seq_file *seq;
2581 int ret = -EINVAL;
2582
2583 task = get_proc_task(inode);
2584 if (task) {
2585 rcu_read_lock();
2586 ns = get_user_ns(task_cred_xxx(task, user_ns));
2587 rcu_read_unlock();
2588 put_task_struct(task);
2589 }
2590 if (!ns)
2591 goto err;
2592
2593 ret = seq_open(file, seq_ops);
2594 if (ret)
2595 goto err_put_ns;
2596
2597 seq = file->private_data;
2598 seq->private = ns;
2599
2600 return 0;
2601 err_put_ns:
2602 put_user_ns(ns);
2603 err:
2604 return ret;
2605 }
2606
2607 static int proc_id_map_release(struct inode *inode, struct file *file)
2608 {
2609 struct seq_file *seq = file->private_data;
2610 struct user_namespace *ns = seq->private;
2611 put_user_ns(ns);
2612 return seq_release(inode, file);
2613 }
2614
2615 static int proc_uid_map_open(struct inode *inode, struct file *file)
2616 {
2617 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2618 }
2619
2620 static int proc_gid_map_open(struct inode *inode, struct file *file)
2621 {
2622 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2623 }
2624
2625 static int proc_projid_map_open(struct inode *inode, struct file *file)
2626 {
2627 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2628 }
2629
2630 static const struct file_operations proc_uid_map_operations = {
2631 .open = proc_uid_map_open,
2632 .write = proc_uid_map_write,
2633 .read = seq_read,
2634 .llseek = seq_lseek,
2635 .release = proc_id_map_release,
2636 };
2637
2638 static const struct file_operations proc_gid_map_operations = {
2639 .open = proc_gid_map_open,
2640 .write = proc_gid_map_write,
2641 .read = seq_read,
2642 .llseek = seq_lseek,
2643 .release = proc_id_map_release,
2644 };
2645
2646 static const struct file_operations proc_projid_map_operations = {
2647 .open = proc_projid_map_open,
2648 .write = proc_projid_map_write,
2649 .read = seq_read,
2650 .llseek = seq_lseek,
2651 .release = proc_id_map_release,
2652 };
2653
2654 static int proc_setgroups_open(struct inode *inode, struct file *file)
2655 {
2656 struct user_namespace *ns = NULL;
2657 struct task_struct *task;
2658 int ret;
2659
2660 ret = -ESRCH;
2661 task = get_proc_task(inode);
2662 if (task) {
2663 rcu_read_lock();
2664 ns = get_user_ns(task_cred_xxx(task, user_ns));
2665 rcu_read_unlock();
2666 put_task_struct(task);
2667 }
2668 if (!ns)
2669 goto err;
2670
2671 if (file->f_mode & FMODE_WRITE) {
2672 ret = -EACCES;
2673 if (!ns_capable(ns, CAP_SYS_ADMIN))
2674 goto err_put_ns;
2675 }
2676
2677 ret = single_open(file, &proc_setgroups_show, ns);
2678 if (ret)
2679 goto err_put_ns;
2680
2681 return 0;
2682 err_put_ns:
2683 put_user_ns(ns);
2684 err:
2685 return ret;
2686 }
2687
2688 static int proc_setgroups_release(struct inode *inode, struct file *file)
2689 {
2690 struct seq_file *seq = file->private_data;
2691 struct user_namespace *ns = seq->private;
2692 int ret = single_release(inode, file);
2693 put_user_ns(ns);
2694 return ret;
2695 }
2696
2697 static const struct file_operations proc_setgroups_operations = {
2698 .open = proc_setgroups_open,
2699 .write = proc_setgroups_write,
2700 .read = seq_read,
2701 .llseek = seq_lseek,
2702 .release = proc_setgroups_release,
2703 };
2704 #endif /* CONFIG_USER_NS */
2705
2706 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2707 struct pid *pid, struct task_struct *task)
2708 {
2709 int err = lock_trace(task);
2710 if (!err) {
2711 seq_printf(m, "%08x\n", task->personality);
2712 unlock_trace(task);
2713 }
2714 return err;
2715 }
2716
2717 /*
2718 * Thread groups
2719 */
2720 static const struct file_operations proc_task_operations;
2721 static const struct inode_operations proc_task_inode_operations;
2722
2723 static const struct pid_entry tgid_base_stuff[] = {
2724 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2725 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2726 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2727 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2728 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2729 #ifdef CONFIG_NET
2730 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2731 #endif
2732 REG("environ", S_IRUSR, proc_environ_operations),
2733 ONE("auxv", S_IRUSR, proc_pid_auxv),
2734 ONE("status", S_IRUGO, proc_pid_status),
2735 ONE("personality", S_IRUSR, proc_pid_personality),
2736 ONE("limits", S_IRUGO, proc_pid_limits),
2737 #ifdef CONFIG_SCHED_DEBUG
2738 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2739 #endif
2740 #ifdef CONFIG_SCHED_AUTOGROUP
2741 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2742 #endif
2743 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2744 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2745 ONE("syscall", S_IRUSR, proc_pid_syscall),
2746 #endif
2747 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2748 ONE("stat", S_IRUGO, proc_tgid_stat),
2749 ONE("statm", S_IRUGO, proc_pid_statm),
2750 REG("maps", S_IRUGO, proc_pid_maps_operations),
2751 #ifdef CONFIG_NUMA
2752 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2753 #endif
2754 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2755 LNK("cwd", proc_cwd_link),
2756 LNK("root", proc_root_link),
2757 LNK("exe", proc_exe_link),
2758 REG("mounts", S_IRUGO, proc_mounts_operations),
2759 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2760 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2761 #ifdef CONFIG_PROC_PAGE_MONITOR
2762 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2763 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2764 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2765 #endif
2766 #ifdef CONFIG_SECURITY
2767 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2768 #endif
2769 #ifdef CONFIG_KALLSYMS
2770 ONE("wchan", S_IRUGO, proc_pid_wchan),
2771 #endif
2772 #ifdef CONFIG_STACKTRACE
2773 ONE("stack", S_IRUSR, proc_pid_stack),
2774 #endif
2775 #ifdef CONFIG_SCHED_INFO
2776 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2777 #endif
2778 #ifdef CONFIG_LATENCYTOP
2779 REG("latency", S_IRUGO, proc_lstats_operations),
2780 #endif
2781 #ifdef CONFIG_PROC_PID_CPUSET
2782 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2783 #endif
2784 #ifdef CONFIG_CGROUPS
2785 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2786 #endif
2787 ONE("oom_score", S_IRUGO, proc_oom_score),
2788 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2789 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2790 #ifdef CONFIG_AUDITSYSCALL
2791 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2792 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2793 #endif
2794 #ifdef CONFIG_FAULT_INJECTION
2795 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2796 #endif
2797 #ifdef CONFIG_ELF_CORE
2798 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2799 #endif
2800 #ifdef CONFIG_TASK_IO_ACCOUNTING
2801 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2802 #endif
2803 #ifdef CONFIG_HARDWALL
2804 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2805 #endif
2806 #ifdef CONFIG_USER_NS
2807 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2808 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2809 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2810 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2811 #endif
2812 #ifdef CONFIG_CHECKPOINT_RESTORE
2813 REG("timers", S_IRUGO, proc_timers_operations),
2814 #endif
2815 };
2816
2817 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2818 {
2819 return proc_pident_readdir(file, ctx,
2820 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2821 }
2822
2823 static const struct file_operations proc_tgid_base_operations = {
2824 .read = generic_read_dir,
2825 .iterate = proc_tgid_base_readdir,
2826 .llseek = default_llseek,
2827 };
2828
2829 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2830 {
2831 return proc_pident_lookup(dir, dentry,
2832 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2833 }
2834
2835 static const struct inode_operations proc_tgid_base_inode_operations = {
2836 .lookup = proc_tgid_base_lookup,
2837 .getattr = pid_getattr,
2838 .setattr = proc_setattr,
2839 .permission = proc_pid_permission,
2840 };
2841
2842 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2843 {
2844 struct dentry *dentry, *leader, *dir;
2845 char buf[PROC_NUMBUF];
2846 struct qstr name;
2847
2848 name.name = buf;
2849 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2850 /* no ->d_hash() rejects on procfs */
2851 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2852 if (dentry) {
2853 d_invalidate(dentry);
2854 dput(dentry);
2855 }
2856
2857 if (pid == tgid)
2858 return;
2859
2860 name.name = buf;
2861 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2862 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2863 if (!leader)
2864 goto out;
2865
2866 name.name = "task";
2867 name.len = strlen(name.name);
2868 dir = d_hash_and_lookup(leader, &name);
2869 if (!dir)
2870 goto out_put_leader;
2871
2872 name.name = buf;
2873 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2874 dentry = d_hash_and_lookup(dir, &name);
2875 if (dentry) {
2876 d_invalidate(dentry);
2877 dput(dentry);
2878 }
2879
2880 dput(dir);
2881 out_put_leader:
2882 dput(leader);
2883 out:
2884 return;
2885 }
2886
2887 /**
2888 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2889 * @task: task that should be flushed.
2890 *
2891 * When flushing dentries from proc, one needs to flush them from global
2892 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2893 * in. This call is supposed to do all of this job.
2894 *
2895 * Looks in the dcache for
2896 * /proc/@pid
2897 * /proc/@tgid/task/@pid
2898 * if either directory is present flushes it and all of it'ts children
2899 * from the dcache.
2900 *
2901 * It is safe and reasonable to cache /proc entries for a task until
2902 * that task exits. After that they just clog up the dcache with
2903 * useless entries, possibly causing useful dcache entries to be
2904 * flushed instead. This routine is proved to flush those useless
2905 * dcache entries at process exit time.
2906 *
2907 * NOTE: This routine is just an optimization so it does not guarantee
2908 * that no dcache entries will exist at process exit time it
2909 * just makes it very unlikely that any will persist.
2910 */
2911
2912 void proc_flush_task(struct task_struct *task)
2913 {
2914 int i;
2915 struct pid *pid, *tgid;
2916 struct upid *upid;
2917
2918 pid = task_pid(task);
2919 tgid = task_tgid(task);
2920
2921 for (i = 0; i <= pid->level; i++) {
2922 upid = &pid->numbers[i];
2923 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2924 tgid->numbers[i].nr);
2925 }
2926 }
2927
2928 static int proc_pid_instantiate(struct inode *dir,
2929 struct dentry * dentry,
2930 struct task_struct *task, const void *ptr)
2931 {
2932 struct inode *inode;
2933
2934 inode = proc_pid_make_inode(dir->i_sb, task);
2935 if (!inode)
2936 goto out;
2937
2938 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2939 inode->i_op = &proc_tgid_base_inode_operations;
2940 inode->i_fop = &proc_tgid_base_operations;
2941 inode->i_flags|=S_IMMUTABLE;
2942
2943 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2944 ARRAY_SIZE(tgid_base_stuff)));
2945
2946 d_set_d_op(dentry, &pid_dentry_operations);
2947
2948 d_add(dentry, inode);
2949 /* Close the race of the process dying before we return the dentry */
2950 if (pid_revalidate(dentry, 0))
2951 return 0;
2952 out:
2953 return -ENOENT;
2954 }
2955
2956 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2957 {
2958 int result = -ENOENT;
2959 struct task_struct *task;
2960 unsigned tgid;
2961 struct pid_namespace *ns;
2962
2963 tgid = name_to_int(&dentry->d_name);
2964 if (tgid == ~0U)
2965 goto out;
2966
2967 ns = dentry->d_sb->s_fs_info;
2968 rcu_read_lock();
2969 task = find_task_by_pid_ns(tgid, ns);
2970 if (task)
2971 get_task_struct(task);
2972 rcu_read_unlock();
2973 if (!task)
2974 goto out;
2975
2976 result = proc_pid_instantiate(dir, dentry, task, NULL);
2977 put_task_struct(task);
2978 out:
2979 return ERR_PTR(result);
2980 }
2981
2982 /*
2983 * Find the first task with tgid >= tgid
2984 *
2985 */
2986 struct tgid_iter {
2987 unsigned int tgid;
2988 struct task_struct *task;
2989 };
2990 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2991 {
2992 struct pid *pid;
2993
2994 if (iter.task)
2995 put_task_struct(iter.task);
2996 rcu_read_lock();
2997 retry:
2998 iter.task = NULL;
2999 pid = find_ge_pid(iter.tgid, ns);
3000 if (pid) {
3001 iter.tgid = pid_nr_ns(pid, ns);
3002 iter.task = pid_task(pid, PIDTYPE_PID);
3003 /* What we to know is if the pid we have find is the
3004 * pid of a thread_group_leader. Testing for task
3005 * being a thread_group_leader is the obvious thing
3006 * todo but there is a window when it fails, due to
3007 * the pid transfer logic in de_thread.
3008 *
3009 * So we perform the straight forward test of seeing
3010 * if the pid we have found is the pid of a thread
3011 * group leader, and don't worry if the task we have
3012 * found doesn't happen to be a thread group leader.
3013 * As we don't care in the case of readdir.
3014 */
3015 if (!iter.task || !has_group_leader_pid(iter.task)) {
3016 iter.tgid += 1;
3017 goto retry;
3018 }
3019 get_task_struct(iter.task);
3020 }
3021 rcu_read_unlock();
3022 return iter;
3023 }
3024
3025 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3026
3027 /* for the /proc/ directory itself, after non-process stuff has been done */
3028 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3029 {
3030 struct tgid_iter iter;
3031 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3032 loff_t pos = ctx->pos;
3033
3034 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3035 return 0;
3036
3037 if (pos == TGID_OFFSET - 2) {
3038 struct inode *inode = d_inode(ns->proc_self);
3039 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3040 return 0;
3041 ctx->pos = pos = pos + 1;
3042 }
3043 if (pos == TGID_OFFSET - 1) {
3044 struct inode *inode = d_inode(ns->proc_thread_self);
3045 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3046 return 0;
3047 ctx->pos = pos = pos + 1;
3048 }
3049 iter.tgid = pos - TGID_OFFSET;
3050 iter.task = NULL;
3051 for (iter = next_tgid(ns, iter);
3052 iter.task;
3053 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3054 char name[PROC_NUMBUF];
3055 int len;
3056 if (!has_pid_permissions(ns, iter.task, 2))
3057 continue;
3058
3059 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3060 ctx->pos = iter.tgid + TGID_OFFSET;
3061 if (!proc_fill_cache(file, ctx, name, len,
3062 proc_pid_instantiate, iter.task, NULL)) {
3063 put_task_struct(iter.task);
3064 return 0;
3065 }
3066 }
3067 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3068 return 0;
3069 }
3070
3071 /*
3072 * Tasks
3073 */
3074 static const struct pid_entry tid_base_stuff[] = {
3075 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3076 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3077 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3078 #ifdef CONFIG_NET
3079 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3080 #endif
3081 REG("environ", S_IRUSR, proc_environ_operations),
3082 ONE("auxv", S_IRUSR, proc_pid_auxv),
3083 ONE("status", S_IRUGO, proc_pid_status),
3084 ONE("personality", S_IRUSR, proc_pid_personality),
3085 ONE("limits", S_IRUGO, proc_pid_limits),
3086 #ifdef CONFIG_SCHED_DEBUG
3087 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3088 #endif
3089 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3090 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3091 ONE("syscall", S_IRUSR, proc_pid_syscall),
3092 #endif
3093 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3094 ONE("stat", S_IRUGO, proc_tid_stat),
3095 ONE("statm", S_IRUGO, proc_pid_statm),
3096 REG("maps", S_IRUGO, proc_tid_maps_operations),
3097 #ifdef CONFIG_PROC_CHILDREN
3098 REG("children", S_IRUGO, proc_tid_children_operations),
3099 #endif
3100 #ifdef CONFIG_NUMA
3101 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3102 #endif
3103 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3104 LNK("cwd", proc_cwd_link),
3105 LNK("root", proc_root_link),
3106 LNK("exe", proc_exe_link),
3107 REG("mounts", S_IRUGO, proc_mounts_operations),
3108 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3109 #ifdef CONFIG_PROC_PAGE_MONITOR
3110 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3111 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3112 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3113 #endif
3114 #ifdef CONFIG_SECURITY
3115 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3116 #endif
3117 #ifdef CONFIG_KALLSYMS
3118 ONE("wchan", S_IRUGO, proc_pid_wchan),
3119 #endif
3120 #ifdef CONFIG_STACKTRACE
3121 ONE("stack", S_IRUSR, proc_pid_stack),
3122 #endif
3123 #ifdef CONFIG_SCHED_INFO
3124 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3125 #endif
3126 #ifdef CONFIG_LATENCYTOP
3127 REG("latency", S_IRUGO, proc_lstats_operations),
3128 #endif
3129 #ifdef CONFIG_PROC_PID_CPUSET
3130 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3131 #endif
3132 #ifdef CONFIG_CGROUPS
3133 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3134 #endif
3135 ONE("oom_score", S_IRUGO, proc_oom_score),
3136 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3137 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3138 #ifdef CONFIG_AUDITSYSCALL
3139 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3140 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3141 #endif
3142 #ifdef CONFIG_FAULT_INJECTION
3143 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3144 #endif
3145 #ifdef CONFIG_TASK_IO_ACCOUNTING
3146 ONE("io", S_IRUSR, proc_tid_io_accounting),
3147 #endif
3148 #ifdef CONFIG_HARDWALL
3149 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3150 #endif
3151 #ifdef CONFIG_USER_NS
3152 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3153 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3154 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3155 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3156 #endif
3157 };
3158
3159 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3160 {
3161 return proc_pident_readdir(file, ctx,
3162 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3163 }
3164
3165 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3166 {
3167 return proc_pident_lookup(dir, dentry,
3168 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3169 }
3170
3171 static const struct file_operations proc_tid_base_operations = {
3172 .read = generic_read_dir,
3173 .iterate = proc_tid_base_readdir,
3174 .llseek = default_llseek,
3175 };
3176
3177 static const struct inode_operations proc_tid_base_inode_operations = {
3178 .lookup = proc_tid_base_lookup,
3179 .getattr = pid_getattr,
3180 .setattr = proc_setattr,
3181 };
3182
3183 static int proc_task_instantiate(struct inode *dir,
3184 struct dentry *dentry, struct task_struct *task, const void *ptr)
3185 {
3186 struct inode *inode;
3187 inode = proc_pid_make_inode(dir->i_sb, task);
3188
3189 if (!inode)
3190 goto out;
3191 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3192 inode->i_op = &proc_tid_base_inode_operations;
3193 inode->i_fop = &proc_tid_base_operations;
3194 inode->i_flags|=S_IMMUTABLE;
3195
3196 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3197 ARRAY_SIZE(tid_base_stuff)));
3198
3199 d_set_d_op(dentry, &pid_dentry_operations);
3200
3201 d_add(dentry, inode);
3202 /* Close the race of the process dying before we return the dentry */
3203 if (pid_revalidate(dentry, 0))
3204 return 0;
3205 out:
3206 return -ENOENT;
3207 }
3208
3209 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3210 {
3211 int result = -ENOENT;
3212 struct task_struct *task;
3213 struct task_struct *leader = get_proc_task(dir);
3214 unsigned tid;
3215 struct pid_namespace *ns;
3216
3217 if (!leader)
3218 goto out_no_task;
3219
3220 tid = name_to_int(&dentry->d_name);
3221 if (tid == ~0U)
3222 goto out;
3223
3224 ns = dentry->d_sb->s_fs_info;
3225 rcu_read_lock();
3226 task = find_task_by_pid_ns(tid, ns);
3227 if (task)
3228 get_task_struct(task);
3229 rcu_read_unlock();
3230 if (!task)
3231 goto out;
3232 if (!same_thread_group(leader, task))
3233 goto out_drop_task;
3234
3235 result = proc_task_instantiate(dir, dentry, task, NULL);
3236 out_drop_task:
3237 put_task_struct(task);
3238 out:
3239 put_task_struct(leader);
3240 out_no_task:
3241 return ERR_PTR(result);
3242 }
3243
3244 /*
3245 * Find the first tid of a thread group to return to user space.
3246 *
3247 * Usually this is just the thread group leader, but if the users
3248 * buffer was too small or there was a seek into the middle of the
3249 * directory we have more work todo.
3250 *
3251 * In the case of a short read we start with find_task_by_pid.
3252 *
3253 * In the case of a seek we start with the leader and walk nr
3254 * threads past it.
3255 */
3256 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3257 struct pid_namespace *ns)
3258 {
3259 struct task_struct *pos, *task;
3260 unsigned long nr = f_pos;
3261
3262 if (nr != f_pos) /* 32bit overflow? */
3263 return NULL;
3264
3265 rcu_read_lock();
3266 task = pid_task(pid, PIDTYPE_PID);
3267 if (!task)
3268 goto fail;
3269
3270 /* Attempt to start with the tid of a thread */
3271 if (tid && nr) {
3272 pos = find_task_by_pid_ns(tid, ns);
3273 if (pos && same_thread_group(pos, task))
3274 goto found;
3275 }
3276
3277 /* If nr exceeds the number of threads there is nothing todo */
3278 if (nr >= get_nr_threads(task))
3279 goto fail;
3280
3281 /* If we haven't found our starting place yet start
3282 * with the leader and walk nr threads forward.
3283 */
3284 pos = task = task->group_leader;
3285 do {
3286 if (!nr--)
3287 goto found;
3288 } while_each_thread(task, pos);
3289 fail:
3290 pos = NULL;
3291 goto out;
3292 found:
3293 get_task_struct(pos);
3294 out:
3295 rcu_read_unlock();
3296 return pos;
3297 }
3298
3299 /*
3300 * Find the next thread in the thread list.
3301 * Return NULL if there is an error or no next thread.
3302 *
3303 * The reference to the input task_struct is released.
3304 */
3305 static struct task_struct *next_tid(struct task_struct *start)
3306 {
3307 struct task_struct *pos = NULL;
3308 rcu_read_lock();
3309 if (pid_alive(start)) {
3310 pos = next_thread(start);
3311 if (thread_group_leader(pos))
3312 pos = NULL;
3313 else
3314 get_task_struct(pos);
3315 }
3316 rcu_read_unlock();
3317 put_task_struct(start);
3318 return pos;
3319 }
3320
3321 /* for the /proc/TGID/task/ directories */
3322 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3323 {
3324 struct inode *inode = file_inode(file);
3325 struct task_struct *task;
3326 struct pid_namespace *ns;
3327 int tid;
3328
3329 if (proc_inode_is_dead(inode))
3330 return -ENOENT;
3331
3332 if (!dir_emit_dots(file, ctx))
3333 return 0;
3334
3335 /* f_version caches the tgid value that the last readdir call couldn't
3336 * return. lseek aka telldir automagically resets f_version to 0.
3337 */
3338 ns = inode->i_sb->s_fs_info;
3339 tid = (int)file->f_version;
3340 file->f_version = 0;
3341 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3342 task;
3343 task = next_tid(task), ctx->pos++) {
3344 char name[PROC_NUMBUF];
3345 int len;
3346 tid = task_pid_nr_ns(task, ns);
3347 len = snprintf(name, sizeof(name), "%d", tid);
3348 if (!proc_fill_cache(file, ctx, name, len,
3349 proc_task_instantiate, task, NULL)) {
3350 /* returning this tgid failed, save it as the first
3351 * pid for the next readir call */
3352 file->f_version = (u64)tid;
3353 put_task_struct(task);
3354 break;
3355 }
3356 }
3357
3358 return 0;
3359 }
3360
3361 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3362 {
3363 struct inode *inode = d_inode(dentry);
3364 struct task_struct *p = get_proc_task(inode);
3365 generic_fillattr(inode, stat);
3366
3367 if (p) {
3368 stat->nlink += get_nr_threads(p);
3369 put_task_struct(p);
3370 }
3371
3372 return 0;
3373 }
3374
3375 static const struct inode_operations proc_task_inode_operations = {
3376 .lookup = proc_task_lookup,
3377 .getattr = proc_task_getattr,
3378 .setattr = proc_setattr,
3379 .permission = proc_pid_permission,
3380 };
3381
3382 static const struct file_operations proc_task_operations = {
3383 .read = generic_read_dir,
3384 .iterate = proc_task_readdir,
3385 .llseek = default_llseek,
3386 };
Linux with added FPC-III support