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mm, oom: normalize oom scores to oom_score_adj scale only for userspace
[linux-2.6/btrfs-unstable.git] / fs / proc / base.c
blobd7d711876b6a00e8bf3ba659db8f59d69d6862dc
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/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/user_namespace.h>
85 #include <linux/fs_struct.h>
86 #include <linux/slab.h>
87 #include <linux/flex_array.h>
88 #ifdef CONFIG_HARDWALL
89 #include <asm/hardwall.h>
90 #endif
91 #include <trace/events/oom.h>
92 #include "internal.h"
93
94 /* NOTE:
95 * Implementing inode permission operations in /proc is almost
96 * certainly an error. Permission checks need to happen during
97 * each system call not at open time. The reason is that most of
98 * what we wish to check for permissions in /proc varies at runtime.
99 *
100 * The classic example of a problem is opening file descriptors
101 * in /proc for a task before it execs a suid executable.
102 */
103
104 struct pid_entry {
105 char *name;
106 int len;
107 umode_t mode;
108 const struct inode_operations *iop;
109 const struct file_operations *fop;
110 union proc_op op;
111 };
112
113 #define NOD(NAME, MODE, IOP, FOP, OP) { \
114 .name = (NAME), \
115 .len = sizeof(NAME) - 1, \
116 .mode = MODE, \
117 .iop = IOP, \
118 .fop = FOP, \
119 .op = OP, \
120 }
121
122 #define DIR(NAME, MODE, iops, fops) \
123 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
124 #define LNK(NAME, get_link) \
125 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
126 &proc_pid_link_inode_operations, NULL, \
127 { .proc_get_link = get_link } )
128 #define REG(NAME, MODE, fops) \
129 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
130 #define INF(NAME, MODE, read) \
131 NOD(NAME, (S_IFREG|(MODE)), \
132 NULL, &proc_info_file_operations, \
133 { .proc_read = read } )
134 #define ONE(NAME, MODE, show) \
135 NOD(NAME, (S_IFREG|(MODE)), \
136 NULL, &proc_single_file_operations, \
137 { .proc_show = show } )
138
139 static int proc_fd_permission(struct inode *inode, int mask);
140
141 /*
142 * Count the number of hardlinks for the pid_entry table, excluding the .
143 * and .. links.
144 */
145 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
146 unsigned int n)
147 {
148 unsigned int i;
149 unsigned int count;
150
151 count = 0;
152 for (i = 0; i < n; ++i) {
153 if (S_ISDIR(entries[i].mode))
154 ++count;
155 }
156
157 return count;
158 }
159
160 static int get_task_root(struct task_struct *task, struct path *root)
161 {
162 int result = -ENOENT;
163
164 task_lock(task);
165 if (task->fs) {
166 get_fs_root(task->fs, root);
167 result = 0;
168 }
169 task_unlock(task);
170 return result;
171 }
172
173 static int proc_cwd_link(struct dentry *dentry, struct path *path)
174 {
175 struct task_struct *task = get_proc_task(dentry->d_inode);
176 int result = -ENOENT;
177
178 if (task) {
179 task_lock(task);
180 if (task->fs) {
181 get_fs_pwd(task->fs, path);
182 result = 0;
183 }
184 task_unlock(task);
185 put_task_struct(task);
186 }
187 return result;
188 }
189
190 static int proc_root_link(struct dentry *dentry, struct path *path)
191 {
192 struct task_struct *task = get_proc_task(dentry->d_inode);
193 int result = -ENOENT;
194
195 if (task) {
196 result = get_task_root(task, path);
197 put_task_struct(task);
198 }
199 return result;
200 }
201
202 struct mm_struct *mm_for_maps(struct task_struct *task)
203 {
204 return mm_access(task, PTRACE_MODE_READ);
205 }
206
207 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
208 {
209 int res = 0;
210 unsigned int len;
211 struct mm_struct *mm = get_task_mm(task);
212 if (!mm)
213 goto out;
214 if (!mm->arg_end)
215 goto out_mm; /* Shh! No looking before we're done */
216
217 len = mm->arg_end - mm->arg_start;
218
219 if (len > PAGE_SIZE)
220 len = PAGE_SIZE;
221
222 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
223
224 // If the nul at the end of args has been overwritten, then
225 // assume application is using setproctitle(3).
226 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
227 len = strnlen(buffer, res);
228 if (len < res) {
229 res = len;
230 } else {
231 len = mm->env_end - mm->env_start;
232 if (len > PAGE_SIZE - res)
233 len = PAGE_SIZE - res;
234 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
235 res = strnlen(buffer, res);
236 }
237 }
238 out_mm:
239 mmput(mm);
240 out:
241 return res;
242 }
243
244 static int proc_pid_auxv(struct task_struct *task, char *buffer)
245 {
246 struct mm_struct *mm = mm_for_maps(task);
247 int res = PTR_ERR(mm);
248 if (mm && !IS_ERR(mm)) {
249 unsigned int nwords = 0;
250 do {
251 nwords += 2;
252 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
253 res = nwords * sizeof(mm->saved_auxv[0]);
254 if (res > PAGE_SIZE)
255 res = PAGE_SIZE;
256 memcpy(buffer, mm->saved_auxv, res);
257 mmput(mm);
258 }
259 return res;
260 }
261
262
263 #ifdef CONFIG_KALLSYMS
264 /*
265 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
266 * Returns the resolved symbol. If that fails, simply return the address.
267 */
268 static int proc_pid_wchan(struct task_struct *task, char *buffer)
269 {
270 unsigned long wchan;
271 char symname[KSYM_NAME_LEN];
272
273 wchan = get_wchan(task);
274
275 if (lookup_symbol_name(wchan, symname) < 0)
276 if (!ptrace_may_access(task, PTRACE_MODE_READ))
277 return 0;
278 else
279 return sprintf(buffer, "%lu", wchan);
280 else
281 return sprintf(buffer, "%s", symname);
282 }
283 #endif /* CONFIG_KALLSYMS */
284
285 static int lock_trace(struct task_struct *task)
286 {
287 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
288 if (err)
289 return err;
290 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
291 mutex_unlock(&task->signal->cred_guard_mutex);
292 return -EPERM;
293 }
294 return 0;
295 }
296
297 static void unlock_trace(struct task_struct *task)
298 {
299 mutex_unlock(&task->signal->cred_guard_mutex);
300 }
301
302 #ifdef CONFIG_STACKTRACE
303
304 #define MAX_STACK_TRACE_DEPTH 64
305
306 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
307 struct pid *pid, struct task_struct *task)
308 {
309 struct stack_trace trace;
310 unsigned long *entries;
311 int err;
312 int i;
313
314 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
315 if (!entries)
316 return -ENOMEM;
317
318 trace.nr_entries = 0;
319 trace.max_entries = MAX_STACK_TRACE_DEPTH;
320 trace.entries = entries;
321 trace.skip = 0;
322
323 err = lock_trace(task);
324 if (!err) {
325 save_stack_trace_tsk(task, &trace);
326
327 for (i = 0; i < trace.nr_entries; i++) {
328 seq_printf(m, "[<%pK>] %pS\n",
329 (void *)entries[i], (void *)entries[i]);
330 }
331 unlock_trace(task);
332 }
333 kfree(entries);
334
335 return err;
336 }
337 #endif
338
339 #ifdef CONFIG_SCHEDSTATS
340 /*
341 * Provides /proc/PID/schedstat
342 */
343 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
344 {
345 return sprintf(buffer, "%llu %llu %lu\n",
346 (unsigned long long)task->se.sum_exec_runtime,
347 (unsigned long long)task->sched_info.run_delay,
348 task->sched_info.pcount);
349 }
350 #endif
351
352 #ifdef CONFIG_LATENCYTOP
353 static int lstats_show_proc(struct seq_file *m, void *v)
354 {
355 int i;
356 struct inode *inode = m->private;
357 struct task_struct *task = get_proc_task(inode);
358
359 if (!task)
360 return -ESRCH;
361 seq_puts(m, "Latency Top version : v0.1\n");
362 for (i = 0; i < 32; i++) {
363 struct latency_record *lr = &task->latency_record[i];
364 if (lr->backtrace[0]) {
365 int q;
366 seq_printf(m, "%i %li %li",
367 lr->count, lr->time, lr->max);
368 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
369 unsigned long bt = lr->backtrace[q];
370 if (!bt)
371 break;
372 if (bt == ULONG_MAX)
373 break;
374 seq_printf(m, " %ps", (void *)bt);
375 }
376 seq_putc(m, '\n');
377 }
378
379 }
380 put_task_struct(task);
381 return 0;
382 }
383
384 static int lstats_open(struct inode *inode, struct file *file)
385 {
386 return single_open(file, lstats_show_proc, inode);
387 }
388
389 static ssize_t lstats_write(struct file *file, const char __user *buf,
390 size_t count, loff_t *offs)
391 {
392 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
393
394 if (!task)
395 return -ESRCH;
396 clear_all_latency_tracing(task);
397 put_task_struct(task);
398
399 return count;
400 }
401
402 static const struct file_operations proc_lstats_operations = {
403 .open = lstats_open,
404 .read = seq_read,
405 .write = lstats_write,
406 .llseek = seq_lseek,
407 .release = single_release,
408 };
409
410 #endif
411
412 static int proc_oom_score(struct task_struct *task, char *buffer)
413 {
414 unsigned long totalpages = totalram_pages + total_swap_pages;
415 unsigned long points = 0;
416
417 read_lock(&tasklist_lock);
418 if (pid_alive(task))
419 points = oom_badness(task, NULL, NULL, totalpages) *
420 1000 / totalpages;
421 read_unlock(&tasklist_lock);
422 return sprintf(buffer, "%lu\n", points);
423 }
424
425 struct limit_names {
426 char *name;
427 char *unit;
428 };
429
430 static const struct limit_names lnames[RLIM_NLIMITS] = {
431 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
432 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
433 [RLIMIT_DATA] = {"Max data size", "bytes"},
434 [RLIMIT_STACK] = {"Max stack size", "bytes"},
435 [RLIMIT_CORE] = {"Max core file size", "bytes"},
436 [RLIMIT_RSS] = {"Max resident set", "bytes"},
437 [RLIMIT_NPROC] = {"Max processes", "processes"},
438 [RLIMIT_NOFILE] = {"Max open files", "files"},
439 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
440 [RLIMIT_AS] = {"Max address space", "bytes"},
441 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
442 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
443 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
444 [RLIMIT_NICE] = {"Max nice priority", NULL},
445 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
446 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
447 };
448
449 /* Display limits for a process */
450 static int proc_pid_limits(struct task_struct *task, char *buffer)
451 {
452 unsigned int i;
453 int count = 0;
454 unsigned long flags;
455 char *bufptr = buffer;
456
457 struct rlimit rlim[RLIM_NLIMITS];
458
459 if (!lock_task_sighand(task, &flags))
460 return 0;
461 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
462 unlock_task_sighand(task, &flags);
463
464 /*
465 * print the file header
466 */
467 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
468 "Limit", "Soft Limit", "Hard Limit", "Units");
469
470 for (i = 0; i < RLIM_NLIMITS; i++) {
471 if (rlim[i].rlim_cur == RLIM_INFINITY)
472 count += sprintf(&bufptr[count], "%-25s %-20s ",
473 lnames[i].name, "unlimited");
474 else
475 count += sprintf(&bufptr[count], "%-25s %-20lu ",
476 lnames[i].name, rlim[i].rlim_cur);
477
478 if (rlim[i].rlim_max == RLIM_INFINITY)
479 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
480 else
481 count += sprintf(&bufptr[count], "%-20lu ",
482 rlim[i].rlim_max);
483
484 if (lnames[i].unit)
485 count += sprintf(&bufptr[count], "%-10s\n",
486 lnames[i].unit);
487 else
488 count += sprintf(&bufptr[count], "\n");
489 }
490
491 return count;
492 }
493
494 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
495 static int proc_pid_syscall(struct task_struct *task, char *buffer)
496 {
497 long nr;
498 unsigned long args[6], sp, pc;
499 int res = lock_trace(task);
500 if (res)
501 return res;
502
503 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
504 res = sprintf(buffer, "running\n");
505 else if (nr < 0)
506 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
507 else
508 res = sprintf(buffer,
509 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
510 nr,
511 args[0], args[1], args[2], args[3], args[4], args[5],
512 sp, pc);
513 unlock_trace(task);
514 return res;
515 }
516 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
517
518 /************************************************************************/
519 /* Here the fs part begins */
520 /************************************************************************/
521
522 /* permission checks */
523 static int proc_fd_access_allowed(struct inode *inode)
524 {
525 struct task_struct *task;
526 int allowed = 0;
527 /* Allow access to a task's file descriptors if it is us or we
528 * may use ptrace attach to the process and find out that
529 * information.
530 */
531 task = get_proc_task(inode);
532 if (task) {
533 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
534 put_task_struct(task);
535 }
536 return allowed;
537 }
538
539 int proc_setattr(struct dentry *dentry, struct iattr *attr)
540 {
541 int error;
542 struct inode *inode = dentry->d_inode;
543
544 if (attr->ia_valid & ATTR_MODE)
545 return -EPERM;
546
547 error = inode_change_ok(inode, attr);
548 if (error)
549 return error;
550
551 if ((attr->ia_valid & ATTR_SIZE) &&
552 attr->ia_size != i_size_read(inode)) {
553 error = vmtruncate(inode, attr->ia_size);
554 if (error)
555 return error;
556 }
557
558 setattr_copy(inode, attr);
559 mark_inode_dirty(inode);
560 return 0;
561 }
562
563 /*
564 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
565 * or euid/egid (for hide_pid_min=2)?
566 */
567 static bool has_pid_permissions(struct pid_namespace *pid,
568 struct task_struct *task,
569 int hide_pid_min)
570 {
571 if (pid->hide_pid < hide_pid_min)
572 return true;
573 if (in_group_p(pid->pid_gid))
574 return true;
575 return ptrace_may_access(task, PTRACE_MODE_READ);
576 }
577
578
579 static int proc_pid_permission(struct inode *inode, int mask)
580 {
581 struct pid_namespace *pid = inode->i_sb->s_fs_info;
582 struct task_struct *task;
583 bool has_perms;
584
585 task = get_proc_task(inode);
586 if (!task)
587 return -ESRCH;
588 has_perms = has_pid_permissions(pid, task, 1);
589 put_task_struct(task);
590
591 if (!has_perms) {
592 if (pid->hide_pid == 2) {
593 /*
594 * Let's make getdents(), stat(), and open()
595 * consistent with each other. If a process
596 * may not stat() a file, it shouldn't be seen
597 * in procfs at all.
598 */
599 return -ENOENT;
600 }
601
602 return -EPERM;
603 }
604 return generic_permission(inode, mask);
605 }
606
607
608
609 static const struct inode_operations proc_def_inode_operations = {
610 .setattr = proc_setattr,
611 };
612
613 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
614
615 static ssize_t proc_info_read(struct file * file, char __user * buf,
616 size_t count, loff_t *ppos)
617 {
618 struct inode * inode = file->f_path.dentry->d_inode;
619 unsigned long page;
620 ssize_t length;
621 struct task_struct *task = get_proc_task(inode);
622
623 length = -ESRCH;
624 if (!task)
625 goto out_no_task;
626
627 if (count > PROC_BLOCK_SIZE)
628 count = PROC_BLOCK_SIZE;
629
630 length = -ENOMEM;
631 if (!(page = __get_free_page(GFP_TEMPORARY)))
632 goto out;
633
634 length = PROC_I(inode)->op.proc_read(task, (char*)page);
635
636 if (length >= 0)
637 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
638 free_page(page);
639 out:
640 put_task_struct(task);
641 out_no_task:
642 return length;
643 }
644
645 static const struct file_operations proc_info_file_operations = {
646 .read = proc_info_read,
647 .llseek = generic_file_llseek,
648 };
649
650 static int proc_single_show(struct seq_file *m, void *v)
651 {
652 struct inode *inode = m->private;
653 struct pid_namespace *ns;
654 struct pid *pid;
655 struct task_struct *task;
656 int ret;
657
658 ns = inode->i_sb->s_fs_info;
659 pid = proc_pid(inode);
660 task = get_pid_task(pid, PIDTYPE_PID);
661 if (!task)
662 return -ESRCH;
663
664 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
665
666 put_task_struct(task);
667 return ret;
668 }
669
670 static int proc_single_open(struct inode *inode, struct file *filp)
671 {
672 return single_open(filp, proc_single_show, inode);
673 }
674
675 static const struct file_operations proc_single_file_operations = {
676 .open = proc_single_open,
677 .read = seq_read,
678 .llseek = seq_lseek,
679 .release = single_release,
680 };
681
682 static int mem_open(struct inode* inode, struct file* file)
683 {
684 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
685 struct mm_struct *mm;
686
687 if (!task)
688 return -ESRCH;
689
690 mm = mm_access(task, PTRACE_MODE_ATTACH);
691 put_task_struct(task);
692
693 if (IS_ERR(mm))
694 return PTR_ERR(mm);
695
696 if (mm) {
697 /* ensure this mm_struct can't be freed */
698 atomic_inc(&mm->mm_count);
699 /* but do not pin its memory */
700 mmput(mm);
701 }
702
703 /* OK to pass negative loff_t, we can catch out-of-range */
704 file->f_mode |= FMODE_UNSIGNED_OFFSET;
705 file->private_data = mm;
706
707 return 0;
708 }
709
710 static ssize_t mem_rw(struct file *file, char __user *buf,
711 size_t count, loff_t *ppos, int write)
712 {
713 struct mm_struct *mm = file->private_data;
714 unsigned long addr = *ppos;
715 ssize_t copied;
716 char *page;
717
718 if (!mm)
719 return 0;
720
721 page = (char *)__get_free_page(GFP_TEMPORARY);
722 if (!page)
723 return -ENOMEM;
724
725 copied = 0;
726 if (!atomic_inc_not_zero(&mm->mm_users))
727 goto free;
728
729 while (count > 0) {
730 int this_len = min_t(int, count, PAGE_SIZE);
731
732 if (write && copy_from_user(page, buf, this_len)) {
733 copied = -EFAULT;
734 break;
735 }
736
737 this_len = access_remote_vm(mm, addr, page, this_len, write);
738 if (!this_len) {
739 if (!copied)
740 copied = -EIO;
741 break;
742 }
743
744 if (!write && copy_to_user(buf, page, this_len)) {
745 copied = -EFAULT;
746 break;
747 }
748
749 buf += this_len;
750 addr += this_len;
751 copied += this_len;
752 count -= this_len;
753 }
754 *ppos = addr;
755
756 mmput(mm);
757 free:
758 free_page((unsigned long) page);
759 return copied;
760 }
761
762 static ssize_t mem_read(struct file *file, char __user *buf,
763 size_t count, loff_t *ppos)
764 {
765 return mem_rw(file, buf, count, ppos, 0);
766 }
767
768 static ssize_t mem_write(struct file *file, const char __user *buf,
769 size_t count, loff_t *ppos)
770 {
771 return mem_rw(file, (char __user*)buf, count, ppos, 1);
772 }
773
774 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
775 {
776 switch (orig) {
777 case 0:
778 file->f_pos = offset;
779 break;
780 case 1:
781 file->f_pos += offset;
782 break;
783 default:
784 return -EINVAL;
785 }
786 force_successful_syscall_return();
787 return file->f_pos;
788 }
789
790 static int mem_release(struct inode *inode, struct file *file)
791 {
792 struct mm_struct *mm = file->private_data;
793 if (mm)
794 mmdrop(mm);
795 return 0;
796 }
797
798 static const struct file_operations proc_mem_operations = {
799 .llseek = mem_lseek,
800 .read = mem_read,
801 .write = mem_write,
802 .open = mem_open,
803 .release = mem_release,
804 };
805
806 static ssize_t environ_read(struct file *file, char __user *buf,
807 size_t count, loff_t *ppos)
808 {
809 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
810 char *page;
811 unsigned long src = *ppos;
812 int ret = -ESRCH;
813 struct mm_struct *mm;
814
815 if (!task)
816 goto out_no_task;
817
818 ret = -ENOMEM;
819 page = (char *)__get_free_page(GFP_TEMPORARY);
820 if (!page)
821 goto out;
822
823
824 mm = mm_for_maps(task);
825 ret = PTR_ERR(mm);
826 if (!mm || IS_ERR(mm))
827 goto out_free;
828
829 ret = 0;
830 while (count > 0) {
831 int this_len, retval, max_len;
832
833 this_len = mm->env_end - (mm->env_start + src);
834
835 if (this_len <= 0)
836 break;
837
838 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
839 this_len = (this_len > max_len) ? max_len : this_len;
840
841 retval = access_process_vm(task, (mm->env_start + src),
842 page, this_len, 0);
843
844 if (retval <= 0) {
845 ret = retval;
846 break;
847 }
848
849 if (copy_to_user(buf, page, retval)) {
850 ret = -EFAULT;
851 break;
852 }
853
854 ret += retval;
855 src += retval;
856 buf += retval;
857 count -= retval;
858 }
859 *ppos = src;
860
861 mmput(mm);
862 out_free:
863 free_page((unsigned long) page);
864 out:
865 put_task_struct(task);
866 out_no_task:
867 return ret;
868 }
869
870 static const struct file_operations proc_environ_operations = {
871 .read = environ_read,
872 .llseek = generic_file_llseek,
873 };
874
875 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
876 size_t count, loff_t *ppos)
877 {
878 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
879 char buffer[PROC_NUMBUF];
880 size_t len;
881 int oom_adjust = OOM_DISABLE;
882 unsigned long flags;
883
884 if (!task)
885 return -ESRCH;
886
887 if (lock_task_sighand(task, &flags)) {
888 oom_adjust = task->signal->oom_adj;
889 unlock_task_sighand(task, &flags);
890 }
891
892 put_task_struct(task);
893
894 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
895
896 return simple_read_from_buffer(buf, count, ppos, buffer, len);
897 }
898
899 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
900 size_t count, loff_t *ppos)
901 {
902 struct task_struct *task;
903 char buffer[PROC_NUMBUF];
904 int oom_adjust;
905 unsigned long flags;
906 int err;
907
908 memset(buffer, 0, sizeof(buffer));
909 if (count > sizeof(buffer) - 1)
910 count = sizeof(buffer) - 1;
911 if (copy_from_user(buffer, buf, count)) {
912 err = -EFAULT;
913 goto out;
914 }
915
916 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
917 if (err)
918 goto out;
919 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
920 oom_adjust != OOM_DISABLE) {
921 err = -EINVAL;
922 goto out;
923 }
924
925 task = get_proc_task(file->f_path.dentry->d_inode);
926 if (!task) {
927 err = -ESRCH;
928 goto out;
929 }
930
931 task_lock(task);
932 if (!task->mm) {
933 err = -EINVAL;
934 goto err_task_lock;
935 }
936
937 if (!lock_task_sighand(task, &flags)) {
938 err = -ESRCH;
939 goto err_task_lock;
940 }
941
942 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
943 err = -EACCES;
944 goto err_sighand;
945 }
946
947 /*
948 * Warn that /proc/pid/oom_adj is deprecated, see
949 * Documentation/feature-removal-schedule.txt.
950 */
951 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
952 current->comm, task_pid_nr(current), task_pid_nr(task),
953 task_pid_nr(task));
954 task->signal->oom_adj = oom_adjust;
955 /*
956 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
957 * value is always attainable.
958 */
959 if (task->signal->oom_adj == OOM_ADJUST_MAX)
960 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
961 else
962 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
963 -OOM_DISABLE;
964 trace_oom_score_adj_update(task);
965 err_sighand:
966 unlock_task_sighand(task, &flags);
967 err_task_lock:
968 task_unlock(task);
969 put_task_struct(task);
970 out:
971 return err < 0 ? err : count;
972 }
973
974 static const struct file_operations proc_oom_adjust_operations = {
975 .read = oom_adjust_read,
976 .write = oom_adjust_write,
977 .llseek = generic_file_llseek,
978 };
979
980 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
981 size_t count, loff_t *ppos)
982 {
983 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
984 char buffer[PROC_NUMBUF];
985 int oom_score_adj = OOM_SCORE_ADJ_MIN;
986 unsigned long flags;
987 size_t len;
988
989 if (!task)
990 return -ESRCH;
991 if (lock_task_sighand(task, &flags)) {
992 oom_score_adj = task->signal->oom_score_adj;
993 unlock_task_sighand(task, &flags);
994 }
995 put_task_struct(task);
996 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
997 return simple_read_from_buffer(buf, count, ppos, buffer, len);
998 }
999
1000 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1001 size_t count, loff_t *ppos)
1002 {
1003 struct task_struct *task;
1004 char buffer[PROC_NUMBUF];
1005 unsigned long flags;
1006 int oom_score_adj;
1007 int err;
1008
1009 memset(buffer, 0, sizeof(buffer));
1010 if (count > sizeof(buffer) - 1)
1011 count = sizeof(buffer) - 1;
1012 if (copy_from_user(buffer, buf, count)) {
1013 err = -EFAULT;
1014 goto out;
1015 }
1016
1017 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1018 if (err)
1019 goto out;
1020 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1021 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1022 err = -EINVAL;
1023 goto out;
1024 }
1025
1026 task = get_proc_task(file->f_path.dentry->d_inode);
1027 if (!task) {
1028 err = -ESRCH;
1029 goto out;
1030 }
1031
1032 task_lock(task);
1033 if (!task->mm) {
1034 err = -EINVAL;
1035 goto err_task_lock;
1036 }
1037
1038 if (!lock_task_sighand(task, &flags)) {
1039 err = -ESRCH;
1040 goto err_task_lock;
1041 }
1042
1043 if (oom_score_adj < task->signal->oom_score_adj_min &&
1044 !capable(CAP_SYS_RESOURCE)) {
1045 err = -EACCES;
1046 goto err_sighand;
1047 }
1048
1049 task->signal->oom_score_adj = oom_score_adj;
1050 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1051 task->signal->oom_score_adj_min = oom_score_adj;
1052 trace_oom_score_adj_update(task);
1053 /*
1054 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1055 * always attainable.
1056 */
1057 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1058 task->signal->oom_adj = OOM_DISABLE;
1059 else
1060 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1061 OOM_SCORE_ADJ_MAX;
1062 err_sighand:
1063 unlock_task_sighand(task, &flags);
1064 err_task_lock:
1065 task_unlock(task);
1066 put_task_struct(task);
1067 out:
1068 return err < 0 ? err : count;
1069 }
1070
1071 static const struct file_operations proc_oom_score_adj_operations = {
1072 .read = oom_score_adj_read,
1073 .write = oom_score_adj_write,
1074 .llseek = default_llseek,
1075 };
1076
1077 #ifdef CONFIG_AUDITSYSCALL
1078 #define TMPBUFLEN 21
1079 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1080 size_t count, loff_t *ppos)
1081 {
1082 struct inode * inode = file->f_path.dentry->d_inode;
1083 struct task_struct *task = get_proc_task(inode);
1084 ssize_t length;
1085 char tmpbuf[TMPBUFLEN];
1086
1087 if (!task)
1088 return -ESRCH;
1089 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1090 audit_get_loginuid(task));
1091 put_task_struct(task);
1092 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1093 }
1094
1095 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1096 size_t count, loff_t *ppos)
1097 {
1098 struct inode * inode = file->f_path.dentry->d_inode;
1099 char *page, *tmp;
1100 ssize_t length;
1101 uid_t loginuid;
1102
1103 rcu_read_lock();
1104 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1105 rcu_read_unlock();
1106 return -EPERM;
1107 }
1108 rcu_read_unlock();
1109
1110 if (count >= PAGE_SIZE)
1111 count = PAGE_SIZE - 1;
1112
1113 if (*ppos != 0) {
1114 /* No partial writes. */
1115 return -EINVAL;
1116 }
1117 page = (char*)__get_free_page(GFP_TEMPORARY);
1118 if (!page)
1119 return -ENOMEM;
1120 length = -EFAULT;
1121 if (copy_from_user(page, buf, count))
1122 goto out_free_page;
1123
1124 page[count] = '\0';
1125 loginuid = simple_strtoul(page, &tmp, 10);
1126 if (tmp == page) {
1127 length = -EINVAL;
1128 goto out_free_page;
1129
1130 }
1131 length = audit_set_loginuid(loginuid);
1132 if (likely(length == 0))
1133 length = count;
1134
1135 out_free_page:
1136 free_page((unsigned long) page);
1137 return length;
1138 }
1139
1140 static const struct file_operations proc_loginuid_operations = {
1141 .read = proc_loginuid_read,
1142 .write = proc_loginuid_write,
1143 .llseek = generic_file_llseek,
1144 };
1145
1146 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1147 size_t count, loff_t *ppos)
1148 {
1149 struct inode * inode = file->f_path.dentry->d_inode;
1150 struct task_struct *task = get_proc_task(inode);
1151 ssize_t length;
1152 char tmpbuf[TMPBUFLEN];
1153
1154 if (!task)
1155 return -ESRCH;
1156 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1157 audit_get_sessionid(task));
1158 put_task_struct(task);
1159 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1160 }
1161
1162 static const struct file_operations proc_sessionid_operations = {
1163 .read = proc_sessionid_read,
1164 .llseek = generic_file_llseek,
1165 };
1166 #endif
1167
1168 #ifdef CONFIG_FAULT_INJECTION
1169 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1170 size_t count, loff_t *ppos)
1171 {
1172 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1173 char buffer[PROC_NUMBUF];
1174 size_t len;
1175 int make_it_fail;
1176
1177 if (!task)
1178 return -ESRCH;
1179 make_it_fail = task->make_it_fail;
1180 put_task_struct(task);
1181
1182 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1183
1184 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1185 }
1186
1187 static ssize_t proc_fault_inject_write(struct file * file,
1188 const char __user * buf, size_t count, loff_t *ppos)
1189 {
1190 struct task_struct *task;
1191 char buffer[PROC_NUMBUF], *end;
1192 int make_it_fail;
1193
1194 if (!capable(CAP_SYS_RESOURCE))
1195 return -EPERM;
1196 memset(buffer, 0, sizeof(buffer));
1197 if (count > sizeof(buffer) - 1)
1198 count = sizeof(buffer) - 1;
1199 if (copy_from_user(buffer, buf, count))
1200 return -EFAULT;
1201 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1202 if (*end)
1203 return -EINVAL;
1204 task = get_proc_task(file->f_dentry->d_inode);
1205 if (!task)
1206 return -ESRCH;
1207 task->make_it_fail = make_it_fail;
1208 put_task_struct(task);
1209
1210 return count;
1211 }
1212
1213 static const struct file_operations proc_fault_inject_operations = {
1214 .read = proc_fault_inject_read,
1215 .write = proc_fault_inject_write,
1216 .llseek = generic_file_llseek,
1217 };
1218 #endif
1219
1220
1221 #ifdef CONFIG_SCHED_DEBUG
1222 /*
1223 * Print out various scheduling related per-task fields:
1224 */
1225 static int sched_show(struct seq_file *m, void *v)
1226 {
1227 struct inode *inode = m->private;
1228 struct task_struct *p;
1229
1230 p = get_proc_task(inode);
1231 if (!p)
1232 return -ESRCH;
1233 proc_sched_show_task(p, m);
1234
1235 put_task_struct(p);
1236
1237 return 0;
1238 }
1239
1240 static ssize_t
1241 sched_write(struct file *file, const char __user *buf,
1242 size_t count, loff_t *offset)
1243 {
1244 struct inode *inode = file->f_path.dentry->d_inode;
1245 struct task_struct *p;
1246
1247 p = get_proc_task(inode);
1248 if (!p)
1249 return -ESRCH;
1250 proc_sched_set_task(p);
1251
1252 put_task_struct(p);
1253
1254 return count;
1255 }
1256
1257 static int sched_open(struct inode *inode, struct file *filp)
1258 {
1259 return single_open(filp, sched_show, inode);
1260 }
1261
1262 static const struct file_operations proc_pid_sched_operations = {
1263 .open = sched_open,
1264 .read = seq_read,
1265 .write = sched_write,
1266 .llseek = seq_lseek,
1267 .release = single_release,
1268 };
1269
1270 #endif
1271
1272 #ifdef CONFIG_SCHED_AUTOGROUP
1273 /*
1274 * Print out autogroup related information:
1275 */
1276 static int sched_autogroup_show(struct seq_file *m, void *v)
1277 {
1278 struct inode *inode = m->private;
1279 struct task_struct *p;
1280
1281 p = get_proc_task(inode);
1282 if (!p)
1283 return -ESRCH;
1284 proc_sched_autogroup_show_task(p, m);
1285
1286 put_task_struct(p);
1287
1288 return 0;
1289 }
1290
1291 static ssize_t
1292 sched_autogroup_write(struct file *file, const char __user *buf,
1293 size_t count, loff_t *offset)
1294 {
1295 struct inode *inode = file->f_path.dentry->d_inode;
1296 struct task_struct *p;
1297 char buffer[PROC_NUMBUF];
1298 int nice;
1299 int err;
1300
1301 memset(buffer, 0, sizeof(buffer));
1302 if (count > sizeof(buffer) - 1)
1303 count = sizeof(buffer) - 1;
1304 if (copy_from_user(buffer, buf, count))
1305 return -EFAULT;
1306
1307 err = kstrtoint(strstrip(buffer), 0, &nice);
1308 if (err < 0)
1309 return err;
1310
1311 p = get_proc_task(inode);
1312 if (!p)
1313 return -ESRCH;
1314
1315 err = proc_sched_autogroup_set_nice(p, nice);
1316 if (err)
1317 count = err;
1318
1319 put_task_struct(p);
1320
1321 return count;
1322 }
1323
1324 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1325 {
1326 int ret;
1327
1328 ret = single_open(filp, sched_autogroup_show, NULL);
1329 if (!ret) {
1330 struct seq_file *m = filp->private_data;
1331
1332 m->private = inode;
1333 }
1334 return ret;
1335 }
1336
1337 static const struct file_operations proc_pid_sched_autogroup_operations = {
1338 .open = sched_autogroup_open,
1339 .read = seq_read,
1340 .write = sched_autogroup_write,
1341 .llseek = seq_lseek,
1342 .release = single_release,
1343 };
1344
1345 #endif /* CONFIG_SCHED_AUTOGROUP */
1346
1347 static ssize_t comm_write(struct file *file, const char __user *buf,
1348 size_t count, loff_t *offset)
1349 {
1350 struct inode *inode = file->f_path.dentry->d_inode;
1351 struct task_struct *p;
1352 char buffer[TASK_COMM_LEN];
1353
1354 memset(buffer, 0, sizeof(buffer));
1355 if (count > sizeof(buffer) - 1)
1356 count = sizeof(buffer) - 1;
1357 if (copy_from_user(buffer, buf, count))
1358 return -EFAULT;
1359
1360 p = get_proc_task(inode);
1361 if (!p)
1362 return -ESRCH;
1363
1364 if (same_thread_group(current, p))
1365 set_task_comm(p, buffer);
1366 else
1367 count = -EINVAL;
1368
1369 put_task_struct(p);
1370
1371 return count;
1372 }
1373
1374 static int comm_show(struct seq_file *m, void *v)
1375 {
1376 struct inode *inode = m->private;
1377 struct task_struct *p;
1378
1379 p = get_proc_task(inode);
1380 if (!p)
1381 return -ESRCH;
1382
1383 task_lock(p);
1384 seq_printf(m, "%s\n", p->comm);
1385 task_unlock(p);
1386
1387 put_task_struct(p);
1388
1389 return 0;
1390 }
1391
1392 static int comm_open(struct inode *inode, struct file *filp)
1393 {
1394 return single_open(filp, comm_show, inode);
1395 }
1396
1397 static const struct file_operations proc_pid_set_comm_operations = {
1398 .open = comm_open,
1399 .read = seq_read,
1400 .write = comm_write,
1401 .llseek = seq_lseek,
1402 .release = single_release,
1403 };
1404
1405 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1406 {
1407 struct task_struct *task;
1408 struct mm_struct *mm;
1409 struct file *exe_file;
1410
1411 task = get_proc_task(dentry->d_inode);
1412 if (!task)
1413 return -ENOENT;
1414 mm = get_task_mm(task);
1415 put_task_struct(task);
1416 if (!mm)
1417 return -ENOENT;
1418 exe_file = get_mm_exe_file(mm);
1419 mmput(mm);
1420 if (exe_file) {
1421 *exe_path = exe_file->f_path;
1422 path_get(&exe_file->f_path);
1423 fput(exe_file);
1424 return 0;
1425 } else
1426 return -ENOENT;
1427 }
1428
1429 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1430 {
1431 struct inode *inode = dentry->d_inode;
1432 int error = -EACCES;
1433
1434 /* We don't need a base pointer in the /proc filesystem */
1435 path_put(&nd->path);
1436
1437 /* Are we allowed to snoop on the tasks file descriptors? */
1438 if (!proc_fd_access_allowed(inode))
1439 goto out;
1440
1441 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
1442 out:
1443 return ERR_PTR(error);
1444 }
1445
1446 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1447 {
1448 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1449 char *pathname;
1450 int len;
1451
1452 if (!tmp)
1453 return -ENOMEM;
1454
1455 pathname = d_path(path, tmp, PAGE_SIZE);
1456 len = PTR_ERR(pathname);
1457 if (IS_ERR(pathname))
1458 goto out;
1459 len = tmp + PAGE_SIZE - 1 - pathname;
1460
1461 if (len > buflen)
1462 len = buflen;
1463 if (copy_to_user(buffer, pathname, len))
1464 len = -EFAULT;
1465 out:
1466 free_page((unsigned long)tmp);
1467 return len;
1468 }
1469
1470 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1471 {
1472 int error = -EACCES;
1473 struct inode *inode = dentry->d_inode;
1474 struct path path;
1475
1476 /* Are we allowed to snoop on the tasks file descriptors? */
1477 if (!proc_fd_access_allowed(inode))
1478 goto out;
1479
1480 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1481 if (error)
1482 goto out;
1483
1484 error = do_proc_readlink(&path, buffer, buflen);
1485 path_put(&path);
1486 out:
1487 return error;
1488 }
1489
1490 static const struct inode_operations proc_pid_link_inode_operations = {
1491 .readlink = proc_pid_readlink,
1492 .follow_link = proc_pid_follow_link,
1493 .setattr = proc_setattr,
1494 };
1495
1496
1497 /* building an inode */
1498
1499 static int task_dumpable(struct task_struct *task)
1500 {
1501 int dumpable = 0;
1502 struct mm_struct *mm;
1503
1504 task_lock(task);
1505 mm = task->mm;
1506 if (mm)
1507 dumpable = get_dumpable(mm);
1508 task_unlock(task);
1509 if(dumpable == 1)
1510 return 1;
1511 return 0;
1512 }
1513
1514 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1515 {
1516 struct inode * inode;
1517 struct proc_inode *ei;
1518 const struct cred *cred;
1519
1520 /* We need a new inode */
1521
1522 inode = new_inode(sb);
1523 if (!inode)
1524 goto out;
1525
1526 /* Common stuff */
1527 ei = PROC_I(inode);
1528 inode->i_ino = get_next_ino();
1529 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1530 inode->i_op = &proc_def_inode_operations;
1531
1532 /*
1533 * grab the reference to task.
1534 */
1535 ei->pid = get_task_pid(task, PIDTYPE_PID);
1536 if (!ei->pid)
1537 goto out_unlock;
1538
1539 if (task_dumpable(task)) {
1540 rcu_read_lock();
1541 cred = __task_cred(task);
1542 inode->i_uid = cred->euid;
1543 inode->i_gid = cred->egid;
1544 rcu_read_unlock();
1545 }
1546 security_task_to_inode(task, inode);
1547
1548 out:
1549 return inode;
1550
1551 out_unlock:
1552 iput(inode);
1553 return NULL;
1554 }
1555
1556 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1557 {
1558 struct inode *inode = dentry->d_inode;
1559 struct task_struct *task;
1560 const struct cred *cred;
1561 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1562
1563 generic_fillattr(inode, stat);
1564
1565 rcu_read_lock();
1566 stat->uid = GLOBAL_ROOT_UID;
1567 stat->gid = GLOBAL_ROOT_GID;
1568 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1569 if (task) {
1570 if (!has_pid_permissions(pid, task, 2)) {
1571 rcu_read_unlock();
1572 /*
1573 * This doesn't prevent learning whether PID exists,
1574 * it only makes getattr() consistent with readdir().
1575 */
1576 return -ENOENT;
1577 }
1578 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1579 task_dumpable(task)) {
1580 cred = __task_cred(task);
1581 stat->uid = cred->euid;
1582 stat->gid = cred->egid;
1583 }
1584 }
1585 rcu_read_unlock();
1586 return 0;
1587 }
1588
1589 /* dentry stuff */
1590
1591 /*
1592 * Exceptional case: normally we are not allowed to unhash a busy
1593 * directory. In this case, however, we can do it - no aliasing problems
1594 * due to the way we treat inodes.
1595 *
1596 * Rewrite the inode's ownerships here because the owning task may have
1597 * performed a setuid(), etc.
1598 *
1599 * Before the /proc/pid/status file was created the only way to read
1600 * the effective uid of a /process was to stat /proc/pid. Reading
1601 * /proc/pid/status is slow enough that procps and other packages
1602 * kept stating /proc/pid. To keep the rules in /proc simple I have
1603 * made this apply to all per process world readable and executable
1604 * directories.
1605 */
1606 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1607 {
1608 struct inode *inode;
1609 struct task_struct *task;
1610 const struct cred *cred;
1611
1612 if (nd && nd->flags & LOOKUP_RCU)
1613 return -ECHILD;
1614
1615 inode = dentry->d_inode;
1616 task = get_proc_task(inode);
1617
1618 if (task) {
1619 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1620 task_dumpable(task)) {
1621 rcu_read_lock();
1622 cred = __task_cred(task);
1623 inode->i_uid = cred->euid;
1624 inode->i_gid = cred->egid;
1625 rcu_read_unlock();
1626 } else {
1627 inode->i_uid = GLOBAL_ROOT_UID;
1628 inode->i_gid = GLOBAL_ROOT_GID;
1629 }
1630 inode->i_mode &= ~(S_ISUID | S_ISGID);
1631 security_task_to_inode(task, inode);
1632 put_task_struct(task);
1633 return 1;
1634 }
1635 d_drop(dentry);
1636 return 0;
1637 }
1638
1639 static int pid_delete_dentry(const struct dentry * dentry)
1640 {
1641 /* Is the task we represent dead?
1642 * If so, then don't put the dentry on the lru list,
1643 * kill it immediately.
1644 */
1645 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1646 }
1647
1648 const struct dentry_operations pid_dentry_operations =
1649 {
1650 .d_revalidate = pid_revalidate,
1651 .d_delete = pid_delete_dentry,
1652 };
1653
1654 /* Lookups */
1655
1656 /*
1657 * Fill a directory entry.
1658 *
1659 * If possible create the dcache entry and derive our inode number and
1660 * file type from dcache entry.
1661 *
1662 * Since all of the proc inode numbers are dynamically generated, the inode
1663 * numbers do not exist until the inode is cache. This means creating the
1664 * the dcache entry in readdir is necessary to keep the inode numbers
1665 * reported by readdir in sync with the inode numbers reported
1666 * by stat.
1667 */
1668 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1669 const char *name, int len,
1670 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1671 {
1672 struct dentry *child, *dir = filp->f_path.dentry;
1673 struct inode *inode;
1674 struct qstr qname;
1675 ino_t ino = 0;
1676 unsigned type = DT_UNKNOWN;
1677
1678 qname.name = name;
1679 qname.len = len;
1680 qname.hash = full_name_hash(name, len);
1681
1682 child = d_lookup(dir, &qname);
1683 if (!child) {
1684 struct dentry *new;
1685 new = d_alloc(dir, &qname);
1686 if (new) {
1687 child = instantiate(dir->d_inode, new, task, ptr);
1688 if (child)
1689 dput(new);
1690 else
1691 child = new;
1692 }
1693 }
1694 if (!child || IS_ERR(child) || !child->d_inode)
1695 goto end_instantiate;
1696 inode = child->d_inode;
1697 if (inode) {
1698 ino = inode->i_ino;
1699 type = inode->i_mode >> 12;
1700 }
1701 dput(child);
1702 end_instantiate:
1703 if (!ino)
1704 ino = find_inode_number(dir, &qname);
1705 if (!ino)
1706 ino = 1;
1707 return filldir(dirent, name, len, filp->f_pos, ino, type);
1708 }
1709
1710 static unsigned name_to_int(struct dentry *dentry)
1711 {
1712 const char *name = dentry->d_name.name;
1713 int len = dentry->d_name.len;
1714 unsigned n = 0;
1715
1716 if (len > 1 && *name == '0')
1717 goto out;
1718 while (len-- > 0) {
1719 unsigned c = *name++ - '0';
1720 if (c > 9)
1721 goto out;
1722 if (n >= (~0U-9)/10)
1723 goto out;
1724 n *= 10;
1725 n += c;
1726 }
1727 return n;
1728 out:
1729 return ~0U;
1730 }
1731
1732 #define PROC_FDINFO_MAX 64
1733
1734 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1735 {
1736 struct task_struct *task = get_proc_task(inode);
1737 struct files_struct *files = NULL;
1738 struct file *file;
1739 int fd = proc_fd(inode);
1740
1741 if (task) {
1742 files = get_files_struct(task);
1743 put_task_struct(task);
1744 }
1745 if (files) {
1746 /*
1747 * We are not taking a ref to the file structure, so we must
1748 * hold ->file_lock.
1749 */
1750 spin_lock(&files->file_lock);
1751 file = fcheck_files(files, fd);
1752 if (file) {
1753 unsigned int f_flags;
1754 struct fdtable *fdt;
1755
1756 fdt = files_fdtable(files);
1757 f_flags = file->f_flags & ~O_CLOEXEC;
1758 if (close_on_exec(fd, fdt))
1759 f_flags |= O_CLOEXEC;
1760
1761 if (path) {
1762 *path = file->f_path;
1763 path_get(&file->f_path);
1764 }
1765 if (info)
1766 snprintf(info, PROC_FDINFO_MAX,
1767 "pos:\t%lli\n"
1768 "flags:\t0%o\n",
1769 (long long) file->f_pos,
1770 f_flags);
1771 spin_unlock(&files->file_lock);
1772 put_files_struct(files);
1773 return 0;
1774 }
1775 spin_unlock(&files->file_lock);
1776 put_files_struct(files);
1777 }
1778 return -ENOENT;
1779 }
1780
1781 static int proc_fd_link(struct dentry *dentry, struct path *path)
1782 {
1783 return proc_fd_info(dentry->d_inode, path, NULL);
1784 }
1785
1786 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1787 {
1788 struct inode *inode;
1789 struct task_struct *task;
1790 int fd;
1791 struct files_struct *files;
1792 const struct cred *cred;
1793
1794 if (nd && nd->flags & LOOKUP_RCU)
1795 return -ECHILD;
1796
1797 inode = dentry->d_inode;
1798 task = get_proc_task(inode);
1799 fd = proc_fd(inode);
1800
1801 if (task) {
1802 files = get_files_struct(task);
1803 if (files) {
1804 struct file *file;
1805 rcu_read_lock();
1806 file = fcheck_files(files, fd);
1807 if (file) {
1808 unsigned i_mode, f_mode = file->f_mode;
1809
1810 rcu_read_unlock();
1811 put_files_struct(files);
1812
1813 if (task_dumpable(task)) {
1814 rcu_read_lock();
1815 cred = __task_cred(task);
1816 inode->i_uid = cred->euid;
1817 inode->i_gid = cred->egid;
1818 rcu_read_unlock();
1819 } else {
1820 inode->i_uid = GLOBAL_ROOT_UID;
1821 inode->i_gid = GLOBAL_ROOT_GID;
1822 }
1823
1824 i_mode = S_IFLNK;
1825 if (f_mode & FMODE_READ)
1826 i_mode |= S_IRUSR | S_IXUSR;
1827 if (f_mode & FMODE_WRITE)
1828 i_mode |= S_IWUSR | S_IXUSR;
1829 inode->i_mode = i_mode;
1830
1831 security_task_to_inode(task, inode);
1832 put_task_struct(task);
1833 return 1;
1834 }
1835 rcu_read_unlock();
1836 put_files_struct(files);
1837 }
1838 put_task_struct(task);
1839 }
1840 d_drop(dentry);
1841 return 0;
1842 }
1843
1844 static const struct dentry_operations tid_fd_dentry_operations =
1845 {
1846 .d_revalidate = tid_fd_revalidate,
1847 .d_delete = pid_delete_dentry,
1848 };
1849
1850 static struct dentry *proc_fd_instantiate(struct inode *dir,
1851 struct dentry *dentry, struct task_struct *task, const void *ptr)
1852 {
1853 unsigned fd = *(const unsigned *)ptr;
1854 struct inode *inode;
1855 struct proc_inode *ei;
1856 struct dentry *error = ERR_PTR(-ENOENT);
1857
1858 inode = proc_pid_make_inode(dir->i_sb, task);
1859 if (!inode)
1860 goto out;
1861 ei = PROC_I(inode);
1862 ei->fd = fd;
1863
1864 inode->i_op = &proc_pid_link_inode_operations;
1865 inode->i_size = 64;
1866 ei->op.proc_get_link = proc_fd_link;
1867 d_set_d_op(dentry, &tid_fd_dentry_operations);
1868 d_add(dentry, inode);
1869 /* Close the race of the process dying before we return the dentry */
1870 if (tid_fd_revalidate(dentry, NULL))
1871 error = NULL;
1872
1873 out:
1874 return error;
1875 }
1876
1877 static struct dentry *proc_lookupfd_common(struct inode *dir,
1878 struct dentry *dentry,
1879 instantiate_t instantiate)
1880 {
1881 struct task_struct *task = get_proc_task(dir);
1882 unsigned fd = name_to_int(dentry);
1883 struct dentry *result = ERR_PTR(-ENOENT);
1884
1885 if (!task)
1886 goto out_no_task;
1887 if (fd == ~0U)
1888 goto out;
1889
1890 result = instantiate(dir, dentry, task, &fd);
1891 out:
1892 put_task_struct(task);
1893 out_no_task:
1894 return result;
1895 }
1896
1897 static int proc_readfd_common(struct file * filp, void * dirent,
1898 filldir_t filldir, instantiate_t instantiate)
1899 {
1900 struct dentry *dentry = filp->f_path.dentry;
1901 struct inode *inode = dentry->d_inode;
1902 struct task_struct *p = get_proc_task(inode);
1903 unsigned int fd, ino;
1904 int retval;
1905 struct files_struct * files;
1906
1907 retval = -ENOENT;
1908 if (!p)
1909 goto out_no_task;
1910 retval = 0;
1911
1912 fd = filp->f_pos;
1913 switch (fd) {
1914 case 0:
1915 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1916 goto out;
1917 filp->f_pos++;
1918 case 1:
1919 ino = parent_ino(dentry);
1920 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1921 goto out;
1922 filp->f_pos++;
1923 default:
1924 files = get_files_struct(p);
1925 if (!files)
1926 goto out;
1927 rcu_read_lock();
1928 for (fd = filp->f_pos-2;
1929 fd < files_fdtable(files)->max_fds;
1930 fd++, filp->f_pos++) {
1931 char name[PROC_NUMBUF];
1932 int len;
1933
1934 if (!fcheck_files(files, fd))
1935 continue;
1936 rcu_read_unlock();
1937
1938 len = snprintf(name, sizeof(name), "%d", fd);
1939 if (proc_fill_cache(filp, dirent, filldir,
1940 name, len, instantiate,
1941 p, &fd) < 0) {
1942 rcu_read_lock();
1943 break;
1944 }
1945 rcu_read_lock();
1946 }
1947 rcu_read_unlock();
1948 put_files_struct(files);
1949 }
1950 out:
1951 put_task_struct(p);
1952 out_no_task:
1953 return retval;
1954 }
1955
1956 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1957 struct nameidata *nd)
1958 {
1959 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1960 }
1961
1962 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1963 {
1964 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1965 }
1966
1967 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1968 size_t len, loff_t *ppos)
1969 {
1970 char tmp[PROC_FDINFO_MAX];
1971 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1972 if (!err)
1973 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1974 return err;
1975 }
1976
1977 static const struct file_operations proc_fdinfo_file_operations = {
1978 .open = nonseekable_open,
1979 .read = proc_fdinfo_read,
1980 .llseek = no_llseek,
1981 };
1982
1983 static const struct file_operations proc_fd_operations = {
1984 .read = generic_read_dir,
1985 .readdir = proc_readfd,
1986 .llseek = default_llseek,
1987 };
1988
1989 #ifdef CONFIG_CHECKPOINT_RESTORE
1990
1991 /*
1992 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1993 * which represent vma start and end addresses.
1994 */
1995 static int dname_to_vma_addr(struct dentry *dentry,
1996 unsigned long *start, unsigned long *end)
1997 {
1998 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1999 return -EINVAL;
2000
2001 return 0;
2002 }
2003
2004 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
2005 {
2006 unsigned long vm_start, vm_end;
2007 bool exact_vma_exists = false;
2008 struct mm_struct *mm = NULL;
2009 struct task_struct *task;
2010 const struct cred *cred;
2011 struct inode *inode;
2012 int status = 0;
2013
2014 if (nd && nd->flags & LOOKUP_RCU)
2015 return -ECHILD;
2016
2017 if (!capable(CAP_SYS_ADMIN)) {
2018 status = -EACCES;
2019 goto out_notask;
2020 }
2021
2022 inode = dentry->d_inode;
2023 task = get_proc_task(inode);
2024 if (!task)
2025 goto out_notask;
2026
2027 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2028 goto out;
2029
2030 mm = get_task_mm(task);
2031 if (!mm)
2032 goto out;
2033
2034 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2035 down_read(&mm->mmap_sem);
2036 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2037 up_read(&mm->mmap_sem);
2038 }
2039
2040 mmput(mm);
2041
2042 if (exact_vma_exists) {
2043 if (task_dumpable(task)) {
2044 rcu_read_lock();
2045 cred = __task_cred(task);
2046 inode->i_uid = cred->euid;
2047 inode->i_gid = cred->egid;
2048 rcu_read_unlock();
2049 } else {
2050 inode->i_uid = GLOBAL_ROOT_UID;
2051 inode->i_gid = GLOBAL_ROOT_GID;
2052 }
2053 security_task_to_inode(task, inode);
2054 status = 1;
2055 }
2056
2057 out:
2058 put_task_struct(task);
2059
2060 out_notask:
2061 if (status <= 0)
2062 d_drop(dentry);
2063
2064 return status;
2065 }
2066
2067 static const struct dentry_operations tid_map_files_dentry_operations = {
2068 .d_revalidate = map_files_d_revalidate,
2069 .d_delete = pid_delete_dentry,
2070 };
2071
2072 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2073 {
2074 unsigned long vm_start, vm_end;
2075 struct vm_area_struct *vma;
2076 struct task_struct *task;
2077 struct mm_struct *mm;
2078 int rc;
2079
2080 rc = -ENOENT;
2081 task = get_proc_task(dentry->d_inode);
2082 if (!task)
2083 goto out;
2084
2085 mm = get_task_mm(task);
2086 put_task_struct(task);
2087 if (!mm)
2088 goto out;
2089
2090 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2091 if (rc)
2092 goto out_mmput;
2093
2094 down_read(&mm->mmap_sem);
2095 vma = find_exact_vma(mm, vm_start, vm_end);
2096 if (vma && vma->vm_file) {
2097 *path = vma->vm_file->f_path;
2098 path_get(path);
2099 rc = 0;
2100 }
2101 up_read(&mm->mmap_sem);
2102
2103 out_mmput:
2104 mmput(mm);
2105 out:
2106 return rc;
2107 }
2108
2109 struct map_files_info {
2110 struct file *file;
2111 unsigned long len;
2112 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2113 };
2114
2115 static struct dentry *
2116 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2117 struct task_struct *task, const void *ptr)
2118 {
2119 const struct file *file = ptr;
2120 struct proc_inode *ei;
2121 struct inode *inode;
2122
2123 if (!file)
2124 return ERR_PTR(-ENOENT);
2125
2126 inode = proc_pid_make_inode(dir->i_sb, task);
2127 if (!inode)
2128 return ERR_PTR(-ENOENT);
2129
2130 ei = PROC_I(inode);
2131 ei->op.proc_get_link = proc_map_files_get_link;
2132
2133 inode->i_op = &proc_pid_link_inode_operations;
2134 inode->i_size = 64;
2135 inode->i_mode = S_IFLNK;
2136
2137 if (file->f_mode & FMODE_READ)
2138 inode->i_mode |= S_IRUSR;
2139 if (file->f_mode & FMODE_WRITE)
2140 inode->i_mode |= S_IWUSR;
2141
2142 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2143 d_add(dentry, inode);
2144
2145 return NULL;
2146 }
2147
2148 static struct dentry *proc_map_files_lookup(struct inode *dir,
2149 struct dentry *dentry, struct nameidata *nd)
2150 {
2151 unsigned long vm_start, vm_end;
2152 struct vm_area_struct *vma;
2153 struct task_struct *task;
2154 struct dentry *result;
2155 struct mm_struct *mm;
2156
2157 result = ERR_PTR(-EACCES);
2158 if (!capable(CAP_SYS_ADMIN))
2159 goto out;
2160
2161 result = ERR_PTR(-ENOENT);
2162 task = get_proc_task(dir);
2163 if (!task)
2164 goto out;
2165
2166 result = ERR_PTR(-EACCES);
2167 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2168 goto out_put_task;
2169
2170 result = ERR_PTR(-ENOENT);
2171 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2172 goto out_put_task;
2173
2174 mm = get_task_mm(task);
2175 if (!mm)
2176 goto out_put_task;
2177
2178 down_read(&mm->mmap_sem);
2179 vma = find_exact_vma(mm, vm_start, vm_end);
2180 if (!vma)
2181 goto out_no_vma;
2182
2183 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2184
2185 out_no_vma:
2186 up_read(&mm->mmap_sem);
2187 mmput(mm);
2188 out_put_task:
2189 put_task_struct(task);
2190 out:
2191 return result;
2192 }
2193
2194 static const struct inode_operations proc_map_files_inode_operations = {
2195 .lookup = proc_map_files_lookup,
2196 .permission = proc_fd_permission,
2197 .setattr = proc_setattr,
2198 };
2199
2200 static int
2201 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2202 {
2203 struct dentry *dentry = filp->f_path.dentry;
2204 struct inode *inode = dentry->d_inode;
2205 struct vm_area_struct *vma;
2206 struct task_struct *task;
2207 struct mm_struct *mm;
2208 ino_t ino;
2209 int ret;
2210
2211 ret = -EACCES;
2212 if (!capable(CAP_SYS_ADMIN))
2213 goto out;
2214
2215 ret = -ENOENT;
2216 task = get_proc_task(inode);
2217 if (!task)
2218 goto out;
2219
2220 ret = -EACCES;
2221 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2222 goto out_put_task;
2223
2224 ret = 0;
2225 switch (filp->f_pos) {
2226 case 0:
2227 ino = inode->i_ino;
2228 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2229 goto out_put_task;
2230 filp->f_pos++;
2231 case 1:
2232 ino = parent_ino(dentry);
2233 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2234 goto out_put_task;
2235 filp->f_pos++;
2236 default:
2237 {
2238 unsigned long nr_files, pos, i;
2239 struct flex_array *fa = NULL;
2240 struct map_files_info info;
2241 struct map_files_info *p;
2242
2243 mm = get_task_mm(task);
2244 if (!mm)
2245 goto out_put_task;
2246 down_read(&mm->mmap_sem);
2247
2248 nr_files = 0;
2249
2250 /*
2251 * We need two passes here:
2252 *
2253 * 1) Collect vmas of mapped files with mmap_sem taken
2254 * 2) Release mmap_sem and instantiate entries
2255 *
2256 * otherwise we get lockdep complained, since filldir()
2257 * routine might require mmap_sem taken in might_fault().
2258 */
2259
2260 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2261 if (vma->vm_file && ++pos > filp->f_pos)
2262 nr_files++;
2263 }
2264
2265 if (nr_files) {
2266 fa = flex_array_alloc(sizeof(info), nr_files,
2267 GFP_KERNEL);
2268 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2269 GFP_KERNEL)) {
2270 ret = -ENOMEM;
2271 if (fa)
2272 flex_array_free(fa);
2273 up_read(&mm->mmap_sem);
2274 mmput(mm);
2275 goto out_put_task;
2276 }
2277 for (i = 0, vma = mm->mmap, pos = 2; vma;
2278 vma = vma->vm_next) {
2279 if (!vma->vm_file)
2280 continue;
2281 if (++pos <= filp->f_pos)
2282 continue;
2283
2284 get_file(vma->vm_file);
2285 info.file = vma->vm_file;
2286 info.len = snprintf(info.name,
2287 sizeof(info.name), "%lx-%lx",
2288 vma->vm_start, vma->vm_end);
2289 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2290 BUG();
2291 }
2292 }
2293 up_read(&mm->mmap_sem);
2294
2295 for (i = 0; i < nr_files; i++) {
2296 p = flex_array_get(fa, i);
2297 ret = proc_fill_cache(filp, dirent, filldir,
2298 p->name, p->len,
2299 proc_map_files_instantiate,
2300 task, p->file);
2301 if (ret)
2302 break;
2303 filp->f_pos++;
2304 fput(p->file);
2305 }
2306 for (; i < nr_files; i++) {
2307 /*
2308 * In case of error don't forget
2309 * to put rest of file refs.
2310 */
2311 p = flex_array_get(fa, i);
2312 fput(p->file);
2313 }
2314 if (fa)
2315 flex_array_free(fa);
2316 mmput(mm);
2317 }
2318 }
2319
2320 out_put_task:
2321 put_task_struct(task);
2322 out:
2323 return ret;
2324 }
2325
2326 static const struct file_operations proc_map_files_operations = {
2327 .read = generic_read_dir,
2328 .readdir = proc_map_files_readdir,
2329 .llseek = default_llseek,
2330 };
2331
2332 #endif /* CONFIG_CHECKPOINT_RESTORE */
2333
2334 /*
2335 * /proc/pid/fd needs a special permission handler so that a process can still
2336 * access /proc/self/fd after it has executed a setuid().
2337 */
2338 static int proc_fd_permission(struct inode *inode, int mask)
2339 {
2340 int rv = generic_permission(inode, mask);
2341 if (rv == 0)
2342 return 0;
2343 if (task_pid(current) == proc_pid(inode))
2344 rv = 0;
2345 return rv;
2346 }
2347
2348 /*
2349 * proc directories can do almost nothing..
2350 */
2351 static const struct inode_operations proc_fd_inode_operations = {
2352 .lookup = proc_lookupfd,
2353 .permission = proc_fd_permission,
2354 .setattr = proc_setattr,
2355 };
2356
2357 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2358 struct dentry *dentry, struct task_struct *task, const void *ptr)
2359 {
2360 unsigned fd = *(unsigned *)ptr;
2361 struct inode *inode;
2362 struct proc_inode *ei;
2363 struct dentry *error = ERR_PTR(-ENOENT);
2364
2365 inode = proc_pid_make_inode(dir->i_sb, task);
2366 if (!inode)
2367 goto out;
2368 ei = PROC_I(inode);
2369 ei->fd = fd;
2370 inode->i_mode = S_IFREG | S_IRUSR;
2371 inode->i_fop = &proc_fdinfo_file_operations;
2372 d_set_d_op(dentry, &tid_fd_dentry_operations);
2373 d_add(dentry, inode);
2374 /* Close the race of the process dying before we return the dentry */
2375 if (tid_fd_revalidate(dentry, NULL))
2376 error = NULL;
2377
2378 out:
2379 return error;
2380 }
2381
2382 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2383 struct dentry *dentry,
2384 struct nameidata *nd)
2385 {
2386 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2387 }
2388
2389 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2390 {
2391 return proc_readfd_common(filp, dirent, filldir,
2392 proc_fdinfo_instantiate);
2393 }
2394
2395 static const struct file_operations proc_fdinfo_operations = {
2396 .read = generic_read_dir,
2397 .readdir = proc_readfdinfo,
2398 .llseek = default_llseek,
2399 };
2400
2401 /*
2402 * proc directories can do almost nothing..
2403 */
2404 static const struct inode_operations proc_fdinfo_inode_operations = {
2405 .lookup = proc_lookupfdinfo,
2406 .setattr = proc_setattr,
2407 };
2408
2409
2410 static struct dentry *proc_pident_instantiate(struct inode *dir,
2411 struct dentry *dentry, struct task_struct *task, const void *ptr)
2412 {
2413 const struct pid_entry *p = ptr;
2414 struct inode *inode;
2415 struct proc_inode *ei;
2416 struct dentry *error = ERR_PTR(-ENOENT);
2417
2418 inode = proc_pid_make_inode(dir->i_sb, task);
2419 if (!inode)
2420 goto out;
2421
2422 ei = PROC_I(inode);
2423 inode->i_mode = p->mode;
2424 if (S_ISDIR(inode->i_mode))
2425 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2426 if (p->iop)
2427 inode->i_op = p->iop;
2428 if (p->fop)
2429 inode->i_fop = p->fop;
2430 ei->op = p->op;
2431 d_set_d_op(dentry, &pid_dentry_operations);
2432 d_add(dentry, inode);
2433 /* Close the race of the process dying before we return the dentry */
2434 if (pid_revalidate(dentry, NULL))
2435 error = NULL;
2436 out:
2437 return error;
2438 }
2439
2440 static struct dentry *proc_pident_lookup(struct inode *dir,
2441 struct dentry *dentry,
2442 const struct pid_entry *ents,
2443 unsigned int nents)
2444 {
2445 struct dentry *error;
2446 struct task_struct *task = get_proc_task(dir);
2447 const struct pid_entry *p, *last;
2448
2449 error = ERR_PTR(-ENOENT);
2450
2451 if (!task)
2452 goto out_no_task;
2453
2454 /*
2455 * Yes, it does not scale. And it should not. Don't add
2456 * new entries into /proc/<tgid>/ without very good reasons.
2457 */
2458 last = &ents[nents - 1];
2459 for (p = ents; p <= last; p++) {
2460 if (p->len != dentry->d_name.len)
2461 continue;
2462 if (!memcmp(dentry->d_name.name, p->name, p->len))
2463 break;
2464 }
2465 if (p > last)
2466 goto out;
2467
2468 error = proc_pident_instantiate(dir, dentry, task, p);
2469 out:
2470 put_task_struct(task);
2471 out_no_task:
2472 return error;
2473 }
2474
2475 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2476 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2477 {
2478 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2479 proc_pident_instantiate, task, p);
2480 }
2481
2482 static int proc_pident_readdir(struct file *filp,
2483 void *dirent, filldir_t filldir,
2484 const struct pid_entry *ents, unsigned int nents)
2485 {
2486 int i;
2487 struct dentry *dentry = filp->f_path.dentry;
2488 struct inode *inode = dentry->d_inode;
2489 struct task_struct *task = get_proc_task(inode);
2490 const struct pid_entry *p, *last;
2491 ino_t ino;
2492 int ret;
2493
2494 ret = -ENOENT;
2495 if (!task)
2496 goto out_no_task;
2497
2498 ret = 0;
2499 i = filp->f_pos;
2500 switch (i) {
2501 case 0:
2502 ino = inode->i_ino;
2503 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2504 goto out;
2505 i++;
2506 filp->f_pos++;
2507 /* fall through */
2508 case 1:
2509 ino = parent_ino(dentry);
2510 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2511 goto out;
2512 i++;
2513 filp->f_pos++;
2514 /* fall through */
2515 default:
2516 i -= 2;
2517 if (i >= nents) {
2518 ret = 1;
2519 goto out;
2520 }
2521 p = ents + i;
2522 last = &ents[nents - 1];
2523 while (p <= last) {
2524 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2525 goto out;
2526 filp->f_pos++;
2527 p++;
2528 }
2529 }
2530
2531 ret = 1;
2532 out:
2533 put_task_struct(task);
2534 out_no_task:
2535 return ret;
2536 }
2537
2538 #ifdef CONFIG_SECURITY
2539 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2540 size_t count, loff_t *ppos)
2541 {
2542 struct inode * inode = file->f_path.dentry->d_inode;
2543 char *p = NULL;
2544 ssize_t length;
2545 struct task_struct *task = get_proc_task(inode);
2546
2547 if (!task)
2548 return -ESRCH;
2549
2550 length = security_getprocattr(task,
2551 (char*)file->f_path.dentry->d_name.name,
2552 &p);
2553 put_task_struct(task);
2554 if (length > 0)
2555 length = simple_read_from_buffer(buf, count, ppos, p, length);
2556 kfree(p);
2557 return length;
2558 }
2559
2560 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2561 size_t count, loff_t *ppos)
2562 {
2563 struct inode * inode = file->f_path.dentry->d_inode;
2564 char *page;
2565 ssize_t length;
2566 struct task_struct *task = get_proc_task(inode);
2567
2568 length = -ESRCH;
2569 if (!task)
2570 goto out_no_task;
2571 if (count > PAGE_SIZE)
2572 count = PAGE_SIZE;
2573
2574 /* No partial writes. */
2575 length = -EINVAL;
2576 if (*ppos != 0)
2577 goto out;
2578
2579 length = -ENOMEM;
2580 page = (char*)__get_free_page(GFP_TEMPORARY);
2581 if (!page)
2582 goto out;
2583
2584 length = -EFAULT;
2585 if (copy_from_user(page, buf, count))
2586 goto out_free;
2587
2588 /* Guard against adverse ptrace interaction */
2589 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2590 if (length < 0)
2591 goto out_free;
2592
2593 length = security_setprocattr(task,
2594 (char*)file->f_path.dentry->d_name.name,
2595 (void*)page, count);
2596 mutex_unlock(&task->signal->cred_guard_mutex);
2597 out_free:
2598 free_page((unsigned long) page);
2599 out:
2600 put_task_struct(task);
2601 out_no_task:
2602 return length;
2603 }
2604
2605 static const struct file_operations proc_pid_attr_operations = {
2606 .read = proc_pid_attr_read,
2607 .write = proc_pid_attr_write,
2608 .llseek = generic_file_llseek,
2609 };
2610
2611 static const struct pid_entry attr_dir_stuff[] = {
2612 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2613 REG("prev", S_IRUGO, proc_pid_attr_operations),
2614 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2615 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2616 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2617 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2618 };
2619
2620 static int proc_attr_dir_readdir(struct file * filp,
2621 void * dirent, filldir_t filldir)
2622 {
2623 return proc_pident_readdir(filp,dirent,filldir,
2624 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2625 }
2626
2627 static const struct file_operations proc_attr_dir_operations = {
2628 .read = generic_read_dir,
2629 .readdir = proc_attr_dir_readdir,
2630 .llseek = default_llseek,
2631 };
2632
2633 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2634 struct dentry *dentry, struct nameidata *nd)
2635 {
2636 return proc_pident_lookup(dir, dentry,
2637 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2638 }
2639
2640 static const struct inode_operations proc_attr_dir_inode_operations = {
2641 .lookup = proc_attr_dir_lookup,
2642 .getattr = pid_getattr,
2643 .setattr = proc_setattr,
2644 };
2645
2646 #endif
2647
2648 #ifdef CONFIG_ELF_CORE
2649 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2650 size_t count, loff_t *ppos)
2651 {
2652 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2653 struct mm_struct *mm;
2654 char buffer[PROC_NUMBUF];
2655 size_t len;
2656 int ret;
2657
2658 if (!task)
2659 return -ESRCH;
2660
2661 ret = 0;
2662 mm = get_task_mm(task);
2663 if (mm) {
2664 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2665 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2666 MMF_DUMP_FILTER_SHIFT));
2667 mmput(mm);
2668 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2669 }
2670
2671 put_task_struct(task);
2672
2673 return ret;
2674 }
2675
2676 static ssize_t proc_coredump_filter_write(struct file *file,
2677 const char __user *buf,
2678 size_t count,
2679 loff_t *ppos)
2680 {
2681 struct task_struct *task;
2682 struct mm_struct *mm;
2683 char buffer[PROC_NUMBUF], *end;
2684 unsigned int val;
2685 int ret;
2686 int i;
2687 unsigned long mask;
2688
2689 ret = -EFAULT;
2690 memset(buffer, 0, sizeof(buffer));
2691 if (count > sizeof(buffer) - 1)
2692 count = sizeof(buffer) - 1;
2693 if (copy_from_user(buffer, buf, count))
2694 goto out_no_task;
2695
2696 ret = -EINVAL;
2697 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2698 if (*end == '\n')
2699 end++;
2700 if (end - buffer == 0)
2701 goto out_no_task;
2702
2703 ret = -ESRCH;
2704 task = get_proc_task(file->f_dentry->d_inode);
2705 if (!task)
2706 goto out_no_task;
2707
2708 ret = end - buffer;
2709 mm = get_task_mm(task);
2710 if (!mm)
2711 goto out_no_mm;
2712
2713 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2714 if (val & mask)
2715 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2716 else
2717 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2718 }
2719
2720 mmput(mm);
2721 out_no_mm:
2722 put_task_struct(task);
2723 out_no_task:
2724 return ret;
2725 }
2726
2727 static const struct file_operations proc_coredump_filter_operations = {
2728 .read = proc_coredump_filter_read,
2729 .write = proc_coredump_filter_write,
2730 .llseek = generic_file_llseek,
2731 };
2732 #endif
2733
2734 /*
2735 * /proc/self:
2736 */
2737 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2738 int buflen)
2739 {
2740 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2741 pid_t tgid = task_tgid_nr_ns(current, ns);
2742 char tmp[PROC_NUMBUF];
2743 if (!tgid)
2744 return -ENOENT;
2745 sprintf(tmp, "%d", tgid);
2746 return vfs_readlink(dentry,buffer,buflen,tmp);
2747 }
2748
2749 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2750 {
2751 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2752 pid_t tgid = task_tgid_nr_ns(current, ns);
2753 char *name = ERR_PTR(-ENOENT);
2754 if (tgid) {
2755 name = __getname();
2756 if (!name)
2757 name = ERR_PTR(-ENOMEM);
2758 else
2759 sprintf(name, "%d", tgid);
2760 }
2761 nd_set_link(nd, name);
2762 return NULL;
2763 }
2764
2765 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2766 void *cookie)
2767 {
2768 char *s = nd_get_link(nd);
2769 if (!IS_ERR(s))
2770 __putname(s);
2771 }
2772
2773 static const struct inode_operations proc_self_inode_operations = {
2774 .readlink = proc_self_readlink,
2775 .follow_link = proc_self_follow_link,
2776 .put_link = proc_self_put_link,
2777 };
2778
2779 /*
2780 * proc base
2781 *
2782 * These are the directory entries in the root directory of /proc
2783 * that properly belong to the /proc filesystem, as they describe
2784 * describe something that is process related.
2785 */
2786 static const struct pid_entry proc_base_stuff[] = {
2787 NOD("self", S_IFLNK|S_IRWXUGO,
2788 &proc_self_inode_operations, NULL, {}),
2789 };
2790
2791 static struct dentry *proc_base_instantiate(struct inode *dir,
2792 struct dentry *dentry, struct task_struct *task, const void *ptr)
2793 {
2794 const struct pid_entry *p = ptr;
2795 struct inode *inode;
2796 struct proc_inode *ei;
2797 struct dentry *error;
2798
2799 /* Allocate the inode */
2800 error = ERR_PTR(-ENOMEM);
2801 inode = new_inode(dir->i_sb);
2802 if (!inode)
2803 goto out;
2804
2805 /* Initialize the inode */
2806 ei = PROC_I(inode);
2807 inode->i_ino = get_next_ino();
2808 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2809
2810 /*
2811 * grab the reference to the task.
2812 */
2813 ei->pid = get_task_pid(task, PIDTYPE_PID);
2814 if (!ei->pid)
2815 goto out_iput;
2816
2817 inode->i_mode = p->mode;
2818 if (S_ISDIR(inode->i_mode))
2819 set_nlink(inode, 2);
2820 if (S_ISLNK(inode->i_mode))
2821 inode->i_size = 64;
2822 if (p->iop)
2823 inode->i_op = p->iop;
2824 if (p->fop)
2825 inode->i_fop = p->fop;
2826 ei->op = p->op;
2827 d_add(dentry, inode);
2828 error = NULL;
2829 out:
2830 return error;
2831 out_iput:
2832 iput(inode);
2833 goto out;
2834 }
2835
2836 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2837 {
2838 struct dentry *error;
2839 struct task_struct *task = get_proc_task(dir);
2840 const struct pid_entry *p, *last;
2841
2842 error = ERR_PTR(-ENOENT);
2843
2844 if (!task)
2845 goto out_no_task;
2846
2847 /* Lookup the directory entry */
2848 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2849 for (p = proc_base_stuff; p <= last; p++) {
2850 if (p->len != dentry->d_name.len)
2851 continue;
2852 if (!memcmp(dentry->d_name.name, p->name, p->len))
2853 break;
2854 }
2855 if (p > last)
2856 goto out;
2857
2858 error = proc_base_instantiate(dir, dentry, task, p);
2859
2860 out:
2861 put_task_struct(task);
2862 out_no_task:
2863 return error;
2864 }
2865
2866 static int proc_base_fill_cache(struct file *filp, void *dirent,
2867 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2868 {
2869 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2870 proc_base_instantiate, task, p);
2871 }
2872
2873 #ifdef CONFIG_TASK_IO_ACCOUNTING
2874 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2875 {
2876 struct task_io_accounting acct = task->ioac;
2877 unsigned long flags;
2878 int result;
2879
2880 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2881 if (result)
2882 return result;
2883
2884 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2885 result = -EACCES;
2886 goto out_unlock;
2887 }
2888
2889 if (whole && lock_task_sighand(task, &flags)) {
2890 struct task_struct *t = task;
2891
2892 task_io_accounting_add(&acct, &task->signal->ioac);
2893 while_each_thread(task, t)
2894 task_io_accounting_add(&acct, &t->ioac);
2895
2896 unlock_task_sighand(task, &flags);
2897 }
2898 result = sprintf(buffer,
2899 "rchar: %llu\n"
2900 "wchar: %llu\n"
2901 "syscr: %llu\n"
2902 "syscw: %llu\n"
2903 "read_bytes: %llu\n"
2904 "write_bytes: %llu\n"
2905 "cancelled_write_bytes: %llu\n",
2906 (unsigned long long)acct.rchar,
2907 (unsigned long long)acct.wchar,
2908 (unsigned long long)acct.syscr,
2909 (unsigned long long)acct.syscw,
2910 (unsigned long long)acct.read_bytes,
2911 (unsigned long long)acct.write_bytes,
2912 (unsigned long long)acct.cancelled_write_bytes);
2913 out_unlock:
2914 mutex_unlock(&task->signal->cred_guard_mutex);
2915 return result;
2916 }
2917
2918 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2919 {
2920 return do_io_accounting(task, buffer, 0);
2921 }
2922
2923 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2924 {
2925 return do_io_accounting(task, buffer, 1);
2926 }
2927 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2928
2929 #ifdef CONFIG_USER_NS
2930 static int proc_id_map_open(struct inode *inode, struct file *file,
2931 struct seq_operations *seq_ops)
2932 {
2933 struct user_namespace *ns = NULL;
2934 struct task_struct *task;
2935 struct seq_file *seq;
2936 int ret = -EINVAL;
2937
2938 task = get_proc_task(inode);
2939 if (task) {
2940 rcu_read_lock();
2941 ns = get_user_ns(task_cred_xxx(task, user_ns));
2942 rcu_read_unlock();
2943 put_task_struct(task);
2944 }
2945 if (!ns)
2946 goto err;
2947
2948 ret = seq_open(file, seq_ops);
2949 if (ret)
2950 goto err_put_ns;
2951
2952 seq = file->private_data;
2953 seq->private = ns;
2954
2955 return 0;
2956 err_put_ns:
2957 put_user_ns(ns);
2958 err:
2959 return ret;
2960 }
2961
2962 static int proc_id_map_release(struct inode *inode, struct file *file)
2963 {
2964 struct seq_file *seq = file->private_data;
2965 struct user_namespace *ns = seq->private;
2966 put_user_ns(ns);
2967 return seq_release(inode, file);
2968 }
2969
2970 static int proc_uid_map_open(struct inode *inode, struct file *file)
2971 {
2972 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2973 }
2974
2975 static int proc_gid_map_open(struct inode *inode, struct file *file)
2976 {
2977 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2978 }
2979
2980 static const struct file_operations proc_uid_map_operations = {
2981 .open = proc_uid_map_open,
2982 .write = proc_uid_map_write,
2983 .read = seq_read,
2984 .llseek = seq_lseek,
2985 .release = proc_id_map_release,
2986 };
2987
2988 static const struct file_operations proc_gid_map_operations = {
2989 .open = proc_gid_map_open,
2990 .write = proc_gid_map_write,
2991 .read = seq_read,
2992 .llseek = seq_lseek,
2993 .release = proc_id_map_release,
2994 };
2995 #endif /* CONFIG_USER_NS */
2996
2997 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2998 struct pid *pid, struct task_struct *task)
2999 {
3000 int err = lock_trace(task);
3001 if (!err) {
3002 seq_printf(m, "%08x\n", task->personality);
3003 unlock_trace(task);
3004 }
3005 return err;
3006 }
3007
3008 /*
3009 * Thread groups
3010 */
3011 static const struct file_operations proc_task_operations;
3012 static const struct inode_operations proc_task_inode_operations;
3013
3014 static const struct pid_entry tgid_base_stuff[] = {
3015 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3016 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3017 #ifdef CONFIG_CHECKPOINT_RESTORE
3018 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3019 #endif
3020 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3021 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3022 #ifdef CONFIG_NET
3023 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3024 #endif
3025 REG("environ", S_IRUSR, proc_environ_operations),
3026 INF("auxv", S_IRUSR, proc_pid_auxv),
3027 ONE("status", S_IRUGO, proc_pid_status),
3028 ONE("personality", S_IRUGO, proc_pid_personality),
3029 INF("limits", S_IRUGO, proc_pid_limits),
3030 #ifdef CONFIG_SCHED_DEBUG
3031 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3032 #endif
3033 #ifdef CONFIG_SCHED_AUTOGROUP
3034 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3035 #endif
3036 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3037 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3038 INF("syscall", S_IRUGO, proc_pid_syscall),
3039 #endif
3040 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3041 ONE("stat", S_IRUGO, proc_tgid_stat),
3042 ONE("statm", S_IRUGO, proc_pid_statm),
3043 REG("maps", S_IRUGO, proc_pid_maps_operations),
3044 #ifdef CONFIG_NUMA
3045 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3046 #endif
3047 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3048 LNK("cwd", proc_cwd_link),
3049 LNK("root", proc_root_link),
3050 LNK("exe", proc_exe_link),
3051 REG("mounts", S_IRUGO, proc_mounts_operations),
3052 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3053 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3054 #ifdef CONFIG_PROC_PAGE_MONITOR
3055 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3056 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3057 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3058 #endif
3059 #ifdef CONFIG_SECURITY
3060 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3061 #endif
3062 #ifdef CONFIG_KALLSYMS
3063 INF("wchan", S_IRUGO, proc_pid_wchan),
3064 #endif
3065 #ifdef CONFIG_STACKTRACE
3066 ONE("stack", S_IRUGO, proc_pid_stack),
3067 #endif
3068 #ifdef CONFIG_SCHEDSTATS
3069 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3070 #endif
3071 #ifdef CONFIG_LATENCYTOP
3072 REG("latency", S_IRUGO, proc_lstats_operations),
3073 #endif
3074 #ifdef CONFIG_PROC_PID_CPUSET
3075 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3076 #endif
3077 #ifdef CONFIG_CGROUPS
3078 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3079 #endif
3080 INF("oom_score", S_IRUGO, proc_oom_score),
3081 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3082 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3083 #ifdef CONFIG_AUDITSYSCALL
3084 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3085 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3086 #endif
3087 #ifdef CONFIG_FAULT_INJECTION
3088 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3089 #endif
3090 #ifdef CONFIG_ELF_CORE
3091 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3092 #endif
3093 #ifdef CONFIG_TASK_IO_ACCOUNTING
3094 INF("io", S_IRUSR, proc_tgid_io_accounting),
3095 #endif
3096 #ifdef CONFIG_HARDWALL
3097 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3098 #endif
3099 #ifdef CONFIG_USER_NS
3100 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3101 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3102 #endif
3103 };
3104
3105 static int proc_tgid_base_readdir(struct file * filp,
3106 void * dirent, filldir_t filldir)
3107 {
3108 return proc_pident_readdir(filp,dirent,filldir,
3109 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
3110 }
3111
3112 static const struct file_operations proc_tgid_base_operations = {
3113 .read = generic_read_dir,
3114 .readdir = proc_tgid_base_readdir,
3115 .llseek = default_llseek,
3116 };
3117
3118 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3119 return proc_pident_lookup(dir, dentry,
3120 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3121 }
3122
3123 static const struct inode_operations proc_tgid_base_inode_operations = {
3124 .lookup = proc_tgid_base_lookup,
3125 .getattr = pid_getattr,
3126 .setattr = proc_setattr,
3127 .permission = proc_pid_permission,
3128 };
3129
3130 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3131 {
3132 struct dentry *dentry, *leader, *dir;
3133 char buf[PROC_NUMBUF];
3134 struct qstr name;
3135
3136 name.name = buf;
3137 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3138 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3139 if (dentry) {
3140 shrink_dcache_parent(dentry);
3141 d_drop(dentry);
3142 dput(dentry);
3143 }
3144
3145 name.name = buf;
3146 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3147 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3148 if (!leader)
3149 goto out;
3150
3151 name.name = "task";
3152 name.len = strlen(name.name);
3153 dir = d_hash_and_lookup(leader, &name);
3154 if (!dir)
3155 goto out_put_leader;
3156
3157 name.name = buf;
3158 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3159 dentry = d_hash_and_lookup(dir, &name);
3160 if (dentry) {
3161 shrink_dcache_parent(dentry);
3162 d_drop(dentry);
3163 dput(dentry);
3164 }
3165
3166 dput(dir);
3167 out_put_leader:
3168 dput(leader);
3169 out:
3170 return;
3171 }
3172
3173 /**
3174 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3175 * @task: task that should be flushed.
3176 *
3177 * When flushing dentries from proc, one needs to flush them from global
3178 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3179 * in. This call is supposed to do all of this job.
3180 *
3181 * Looks in the dcache for
3182 * /proc/@pid
3183 * /proc/@tgid/task/@pid
3184 * if either directory is present flushes it and all of it'ts children
3185 * from the dcache.
3186 *
3187 * It is safe and reasonable to cache /proc entries for a task until
3188 * that task exits. After that they just clog up the dcache with
3189 * useless entries, possibly causing useful dcache entries to be
3190 * flushed instead. This routine is proved to flush those useless
3191 * dcache entries at process exit time.
3192 *
3193 * NOTE: This routine is just an optimization so it does not guarantee
3194 * that no dcache entries will exist at process exit time it
3195 * just makes it very unlikely that any will persist.
3196 */
3197
3198 void proc_flush_task(struct task_struct *task)
3199 {
3200 int i;
3201 struct pid *pid, *tgid;
3202 struct upid *upid;
3203
3204 pid = task_pid(task);
3205 tgid = task_tgid(task);
3206
3207 for (i = 0; i <= pid->level; i++) {
3208 upid = &pid->numbers[i];
3209 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3210 tgid->numbers[i].nr);
3211 }
3212
3213 upid = &pid->numbers[pid->level];
3214 if (upid->nr == 1)
3215 pid_ns_release_proc(upid->ns);
3216 }
3217
3218 static struct dentry *proc_pid_instantiate(struct inode *dir,
3219 struct dentry * dentry,
3220 struct task_struct *task, const void *ptr)
3221 {
3222 struct dentry *error = ERR_PTR(-ENOENT);
3223 struct inode *inode;
3224
3225 inode = proc_pid_make_inode(dir->i_sb, task);
3226 if (!inode)
3227 goto out;
3228
3229 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3230 inode->i_op = &proc_tgid_base_inode_operations;
3231 inode->i_fop = &proc_tgid_base_operations;
3232 inode->i_flags|=S_IMMUTABLE;
3233
3234 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3235 ARRAY_SIZE(tgid_base_stuff)));
3236
3237 d_set_d_op(dentry, &pid_dentry_operations);
3238
3239 d_add(dentry, inode);
3240 /* Close the race of the process dying before we return the dentry */
3241 if (pid_revalidate(dentry, NULL))
3242 error = NULL;
3243 out:
3244 return error;
3245 }
3246
3247 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3248 {
3249 struct dentry *result;
3250 struct task_struct *task;
3251 unsigned tgid;
3252 struct pid_namespace *ns;
3253
3254 result = proc_base_lookup(dir, dentry);
3255 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3256 goto out;
3257
3258 tgid = name_to_int(dentry);
3259 if (tgid == ~0U)
3260 goto out;
3261
3262 ns = dentry->d_sb->s_fs_info;
3263 rcu_read_lock();
3264 task = find_task_by_pid_ns(tgid, ns);
3265 if (task)
3266 get_task_struct(task);
3267 rcu_read_unlock();
3268 if (!task)
3269 goto out;
3270
3271 result = proc_pid_instantiate(dir, dentry, task, NULL);
3272 put_task_struct(task);
3273 out:
3274 return result;
3275 }
3276
3277 /*
3278 * Find the first task with tgid >= tgid
3279 *
3280 */
3281 struct tgid_iter {
3282 unsigned int tgid;
3283 struct task_struct *task;
3284 };
3285 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3286 {
3287 struct pid *pid;
3288
3289 if (iter.task)
3290 put_task_struct(iter.task);
3291 rcu_read_lock();
3292 retry:
3293 iter.task = NULL;
3294 pid = find_ge_pid(iter.tgid, ns);
3295 if (pid) {
3296 iter.tgid = pid_nr_ns(pid, ns);
3297 iter.task = pid_task(pid, PIDTYPE_PID);
3298 /* What we to know is if the pid we have find is the
3299 * pid of a thread_group_leader. Testing for task
3300 * being a thread_group_leader is the obvious thing
3301 * todo but there is a window when it fails, due to
3302 * the pid transfer logic in de_thread.
3303 *
3304 * So we perform the straight forward test of seeing
3305 * if the pid we have found is the pid of a thread
3306 * group leader, and don't worry if the task we have
3307 * found doesn't happen to be a thread group leader.
3308 * As we don't care in the case of readdir.
3309 */
3310 if (!iter.task || !has_group_leader_pid(iter.task)) {
3311 iter.tgid += 1;
3312 goto retry;
3313 }
3314 get_task_struct(iter.task);
3315 }
3316 rcu_read_unlock();
3317 return iter;
3318 }
3319
3320 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3321
3322 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3323 struct tgid_iter iter)
3324 {
3325 char name[PROC_NUMBUF];
3326 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3327 return proc_fill_cache(filp, dirent, filldir, name, len,
3328 proc_pid_instantiate, iter.task, NULL);
3329 }
3330
3331 static int fake_filldir(void *buf, const char *name, int namelen,
3332 loff_t offset, u64 ino, unsigned d_type)
3333 {
3334 return 0;
3335 }
3336
3337 /* for the /proc/ directory itself, after non-process stuff has been done */
3338 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3339 {
3340 unsigned int nr;
3341 struct task_struct *reaper;
3342 struct tgid_iter iter;
3343 struct pid_namespace *ns;
3344 filldir_t __filldir;
3345
3346 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3347 goto out_no_task;
3348 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3349
3350 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3351 if (!reaper)
3352 goto out_no_task;
3353
3354 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3355 const struct pid_entry *p = &proc_base_stuff[nr];
3356 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3357 goto out;
3358 }
3359
3360 ns = filp->f_dentry->d_sb->s_fs_info;
3361 iter.task = NULL;
3362 iter.tgid = filp->f_pos - TGID_OFFSET;
3363 for (iter = next_tgid(ns, iter);
3364 iter.task;
3365 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3366 if (has_pid_permissions(ns, iter.task, 2))
3367 __filldir = filldir;
3368 else
3369 __filldir = fake_filldir;
3370
3371 filp->f_pos = iter.tgid + TGID_OFFSET;
3372 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3373 put_task_struct(iter.task);
3374 goto out;
3375 }
3376 }
3377 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3378 out:
3379 put_task_struct(reaper);
3380 out_no_task:
3381 return 0;
3382 }
3383
3384 /*
3385 * Tasks
3386 */
3387 static const struct pid_entry tid_base_stuff[] = {
3388 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3389 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3390 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3391 REG("environ", S_IRUSR, proc_environ_operations),
3392 INF("auxv", S_IRUSR, proc_pid_auxv),
3393 ONE("status", S_IRUGO, proc_pid_status),
3394 ONE("personality", S_IRUGO, proc_pid_personality),
3395 INF("limits", S_IRUGO, proc_pid_limits),
3396 #ifdef CONFIG_SCHED_DEBUG
3397 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3398 #endif
3399 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3400 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3401 INF("syscall", S_IRUGO, proc_pid_syscall),
3402 #endif
3403 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3404 ONE("stat", S_IRUGO, proc_tid_stat),
3405 ONE("statm", S_IRUGO, proc_pid_statm),
3406 REG("maps", S_IRUGO, proc_tid_maps_operations),
3407 #ifdef CONFIG_NUMA
3408 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3409 #endif
3410 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3411 LNK("cwd", proc_cwd_link),
3412 LNK("root", proc_root_link),
3413 LNK("exe", proc_exe_link),
3414 REG("mounts", S_IRUGO, proc_mounts_operations),
3415 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3416 #ifdef CONFIG_PROC_PAGE_MONITOR
3417 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3418 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3419 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3420 #endif
3421 #ifdef CONFIG_SECURITY
3422 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3423 #endif
3424 #ifdef CONFIG_KALLSYMS
3425 INF("wchan", S_IRUGO, proc_pid_wchan),
3426 #endif
3427 #ifdef CONFIG_STACKTRACE
3428 ONE("stack", S_IRUGO, proc_pid_stack),
3429 #endif
3430 #ifdef CONFIG_SCHEDSTATS
3431 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3432 #endif
3433 #ifdef CONFIG_LATENCYTOP
3434 REG("latency", S_IRUGO, proc_lstats_operations),
3435 #endif
3436 #ifdef CONFIG_PROC_PID_CPUSET
3437 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3438 #endif
3439 #ifdef CONFIG_CGROUPS
3440 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3441 #endif
3442 INF("oom_score", S_IRUGO, proc_oom_score),
3443 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3444 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3445 #ifdef CONFIG_AUDITSYSCALL
3446 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3447 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3448 #endif
3449 #ifdef CONFIG_FAULT_INJECTION
3450 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3451 #endif
3452 #ifdef CONFIG_TASK_IO_ACCOUNTING
3453 INF("io", S_IRUSR, proc_tid_io_accounting),
3454 #endif
3455 #ifdef CONFIG_HARDWALL
3456 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3457 #endif
3458 #ifdef CONFIG_USER_NS
3459 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3460 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3461 #endif
3462 };
3463
3464 static int proc_tid_base_readdir(struct file * filp,
3465 void * dirent, filldir_t filldir)
3466 {
3467 return proc_pident_readdir(filp,dirent,filldir,
3468 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3469 }
3470
3471 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3472 return proc_pident_lookup(dir, dentry,
3473 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3474 }
3475
3476 static const struct file_operations proc_tid_base_operations = {
3477 .read = generic_read_dir,
3478 .readdir = proc_tid_base_readdir,
3479 .llseek = default_llseek,
3480 };
3481
3482 static const struct inode_operations proc_tid_base_inode_operations = {
3483 .lookup = proc_tid_base_lookup,
3484 .getattr = pid_getattr,
3485 .setattr = proc_setattr,
3486 };
3487
3488 static struct dentry *proc_task_instantiate(struct inode *dir,
3489 struct dentry *dentry, struct task_struct *task, const void *ptr)
3490 {
3491 struct dentry *error = ERR_PTR(-ENOENT);
3492 struct inode *inode;
3493 inode = proc_pid_make_inode(dir->i_sb, task);
3494
3495 if (!inode)
3496 goto out;
3497 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3498 inode->i_op = &proc_tid_base_inode_operations;
3499 inode->i_fop = &proc_tid_base_operations;
3500 inode->i_flags|=S_IMMUTABLE;
3501
3502 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3503 ARRAY_SIZE(tid_base_stuff)));
3504
3505 d_set_d_op(dentry, &pid_dentry_operations);
3506
3507 d_add(dentry, inode);
3508 /* Close the race of the process dying before we return the dentry */
3509 if (pid_revalidate(dentry, NULL))
3510 error = NULL;
3511 out:
3512 return error;
3513 }
3514
3515 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3516 {
3517 struct dentry *result = ERR_PTR(-ENOENT);
3518 struct task_struct *task;
3519 struct task_struct *leader = get_proc_task(dir);
3520 unsigned tid;
3521 struct pid_namespace *ns;
3522
3523 if (!leader)
3524 goto out_no_task;
3525
3526 tid = name_to_int(dentry);
3527 if (tid == ~0U)
3528 goto out;
3529
3530 ns = dentry->d_sb->s_fs_info;
3531 rcu_read_lock();
3532 task = find_task_by_pid_ns(tid, ns);
3533 if (task)
3534 get_task_struct(task);
3535 rcu_read_unlock();
3536 if (!task)
3537 goto out;
3538 if (!same_thread_group(leader, task))
3539 goto out_drop_task;
3540
3541 result = proc_task_instantiate(dir, dentry, task, NULL);
3542 out_drop_task:
3543 put_task_struct(task);
3544 out:
3545 put_task_struct(leader);
3546 out_no_task:
3547 return result;
3548 }
3549
3550 /*
3551 * Find the first tid of a thread group to return to user space.
3552 *
3553 * Usually this is just the thread group leader, but if the users
3554 * buffer was too small or there was a seek into the middle of the
3555 * directory we have more work todo.
3556 *
3557 * In the case of a short read we start with find_task_by_pid.
3558 *
3559 * In the case of a seek we start with the leader and walk nr
3560 * threads past it.
3561 */
3562 static struct task_struct *first_tid(struct task_struct *leader,
3563 int tid, int nr, struct pid_namespace *ns)
3564 {
3565 struct task_struct *pos;
3566
3567 rcu_read_lock();
3568 /* Attempt to start with the pid of a thread */
3569 if (tid && (nr > 0)) {
3570 pos = find_task_by_pid_ns(tid, ns);
3571 if (pos && (pos->group_leader == leader))
3572 goto found;
3573 }
3574
3575 /* If nr exceeds the number of threads there is nothing todo */
3576 pos = NULL;
3577 if (nr && nr >= get_nr_threads(leader))
3578 goto out;
3579
3580 /* If we haven't found our starting place yet start
3581 * with the leader and walk nr threads forward.
3582 */
3583 for (pos = leader; nr > 0; --nr) {
3584 pos = next_thread(pos);
3585 if (pos == leader) {
3586 pos = NULL;
3587 goto out;
3588 }
3589 }
3590 found:
3591 get_task_struct(pos);
3592 out:
3593 rcu_read_unlock();
3594 return pos;
3595 }
3596
3597 /*
3598 * Find the next thread in the thread list.
3599 * Return NULL if there is an error or no next thread.
3600 *
3601 * The reference to the input task_struct is released.
3602 */
3603 static struct task_struct *next_tid(struct task_struct *start)
3604 {
3605 struct task_struct *pos = NULL;
3606 rcu_read_lock();
3607 if (pid_alive(start)) {
3608 pos = next_thread(start);
3609 if (thread_group_leader(pos))
3610 pos = NULL;
3611 else
3612 get_task_struct(pos);
3613 }
3614 rcu_read_unlock();
3615 put_task_struct(start);
3616 return pos;
3617 }
3618
3619 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3620 struct task_struct *task, int tid)
3621 {
3622 char name[PROC_NUMBUF];
3623 int len = snprintf(name, sizeof(name), "%d", tid);
3624 return proc_fill_cache(filp, dirent, filldir, name, len,
3625 proc_task_instantiate, task, NULL);
3626 }
3627
3628 /* for the /proc/TGID/task/ directories */
3629 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3630 {
3631 struct dentry *dentry = filp->f_path.dentry;
3632 struct inode *inode = dentry->d_inode;
3633 struct task_struct *leader = NULL;
3634 struct task_struct *task;
3635 int retval = -ENOENT;
3636 ino_t ino;
3637 int tid;
3638 struct pid_namespace *ns;
3639
3640 task = get_proc_task(inode);
3641 if (!task)
3642 goto out_no_task;
3643 rcu_read_lock();
3644 if (pid_alive(task)) {
3645 leader = task->group_leader;
3646 get_task_struct(leader);
3647 }
3648 rcu_read_unlock();
3649 put_task_struct(task);
3650 if (!leader)
3651 goto out_no_task;
3652 retval = 0;
3653
3654 switch ((unsigned long)filp->f_pos) {
3655 case 0:
3656 ino = inode->i_ino;
3657 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3658 goto out;
3659 filp->f_pos++;
3660 /* fall through */
3661 case 1:
3662 ino = parent_ino(dentry);
3663 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3664 goto out;
3665 filp->f_pos++;
3666 /* fall through */
3667 }
3668
3669 /* f_version caches the tgid value that the last readdir call couldn't
3670 * return. lseek aka telldir automagically resets f_version to 0.
3671 */
3672 ns = filp->f_dentry->d_sb->s_fs_info;
3673 tid = (int)filp->f_version;
3674 filp->f_version = 0;
3675 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3676 task;
3677 task = next_tid(task), filp->f_pos++) {
3678 tid = task_pid_nr_ns(task, ns);
3679 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3680 /* returning this tgid failed, save it as the first
3681 * pid for the next readir call */
3682 filp->f_version = (u64)tid;
3683 put_task_struct(task);
3684 break;
3685 }
3686 }
3687 out:
3688 put_task_struct(leader);
3689 out_no_task:
3690 return retval;
3691 }
3692
3693 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3694 {
3695 struct inode *inode = dentry->d_inode;
3696 struct task_struct *p = get_proc_task(inode);
3697 generic_fillattr(inode, stat);
3698
3699 if (p) {
3700 stat->nlink += get_nr_threads(p);
3701 put_task_struct(p);
3702 }
3703
3704 return 0;
3705 }
3706
3707 static const struct inode_operations proc_task_inode_operations = {
3708 .lookup = proc_task_lookup,
3709 .getattr = proc_task_getattr,
3710 .setattr = proc_setattr,
3711 .permission = proc_pid_permission,
3712 };
3713
3714 static const struct file_operations proc_task_operations = {
3715 .read = generic_read_dir,
3716 .readdir = proc_task_readdir,
3717 .llseek = default_llseek,
3718 };
(deprecated) Btrfs devel tree