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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[wrt350n-kernel.git] / fs / proc / base.c
blob9a4da0aae02e442e5be76fa84a0907a43e1bf848
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/init.h>
57 #include <linux/capability.h>
58 #include <linux/file.h>
59 #include <linux/string.h>
60 #include <linux/seq_file.h>
61 #include <linux/namei.h>
62 #include <linux/mnt_namespace.h>
63 #include <linux/mm.h>
64 #include <linux/rcupdate.h>
65 #include <linux/kallsyms.h>
66 #include <linux/resource.h>
67 #include <linux/module.h>
68 #include <linux/mount.h>
69 #include <linux/security.h>
70 #include <linux/ptrace.h>
71 #include <linux/cgroup.h>
72 #include <linux/cpuset.h>
73 #include <linux/audit.h>
74 #include <linux/poll.h>
75 #include <linux/nsproxy.h>
76 #include <linux/oom.h>
77 #include <linux/elf.h>
78 #include <linux/pid_namespace.h>
79 #include "internal.h"
80
81 /* NOTE:
82 * Implementing inode permission operations in /proc is almost
83 * certainly an error. Permission checks need to happen during
84 * each system call not at open time. The reason is that most of
85 * what we wish to check for permissions in /proc varies at runtime.
86 *
87 * The classic example of a problem is opening file descriptors
88 * in /proc for a task before it execs a suid executable.
89 */
90
91 struct pid_entry {
92 char *name;
93 int len;
94 mode_t mode;
95 const struct inode_operations *iop;
96 const struct file_operations *fop;
97 union proc_op op;
98 };
99
100 #define NOD(NAME, MODE, IOP, FOP, OP) { \
101 .name = (NAME), \
102 .len = sizeof(NAME) - 1, \
103 .mode = MODE, \
104 .iop = IOP, \
105 .fop = FOP, \
106 .op = OP, \
107 }
108
109 #define DIR(NAME, MODE, OTYPE) \
110 NOD(NAME, (S_IFDIR|(MODE)), \
111 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
112 {} )
113 #define LNK(NAME, OTYPE) \
114 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
115 &proc_pid_link_inode_operations, NULL, \
116 { .proc_get_link = &proc_##OTYPE##_link } )
117 #define REG(NAME, MODE, OTYPE) \
118 NOD(NAME, (S_IFREG|(MODE)), NULL, \
119 &proc_##OTYPE##_operations, {})
120 #define INF(NAME, MODE, OTYPE) \
121 NOD(NAME, (S_IFREG|(MODE)), \
122 NULL, &proc_info_file_operations, \
123 { .proc_read = &proc_##OTYPE } )
124 #define ONE(NAME, MODE, OTYPE) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_single_file_operations, \
127 { .proc_show = &proc_##OTYPE } )
128
129 int maps_protect;
130 EXPORT_SYMBOL(maps_protect);
131
132 static struct fs_struct *get_fs_struct(struct task_struct *task)
133 {
134 struct fs_struct *fs;
135 task_lock(task);
136 fs = task->fs;
137 if(fs)
138 atomic_inc(&fs->count);
139 task_unlock(task);
140 return fs;
141 }
142
143 static int get_nr_threads(struct task_struct *tsk)
144 {
145 /* Must be called with the rcu_read_lock held */
146 unsigned long flags;
147 int count = 0;
148
149 if (lock_task_sighand(tsk, &flags)) {
150 count = atomic_read(&tsk->signal->count);
151 unlock_task_sighand(tsk, &flags);
152 }
153 return count;
154 }
155
156 static int proc_cwd_link(struct inode *inode, struct path *path)
157 {
158 struct task_struct *task = get_proc_task(inode);
159 struct fs_struct *fs = NULL;
160 int result = -ENOENT;
161
162 if (task) {
163 fs = get_fs_struct(task);
164 put_task_struct(task);
165 }
166 if (fs) {
167 read_lock(&fs->lock);
168 *path = fs->pwd;
169 path_get(&fs->pwd);
170 read_unlock(&fs->lock);
171 result = 0;
172 put_fs_struct(fs);
173 }
174 return result;
175 }
176
177 static int proc_root_link(struct inode *inode, struct path *path)
178 {
179 struct task_struct *task = get_proc_task(inode);
180 struct fs_struct *fs = NULL;
181 int result = -ENOENT;
182
183 if (task) {
184 fs = get_fs_struct(task);
185 put_task_struct(task);
186 }
187 if (fs) {
188 read_lock(&fs->lock);
189 *path = fs->root;
190 path_get(&fs->root);
191 read_unlock(&fs->lock);
192 result = 0;
193 put_fs_struct(fs);
194 }
195 return result;
196 }
197
198 #define MAY_PTRACE(task) \
199 (task == current || \
200 (task->parent == current && \
201 (task->ptrace & PT_PTRACED) && \
202 (task_is_stopped_or_traced(task)) && \
203 security_ptrace(current,task) == 0))
204
205 struct mm_struct *mm_for_maps(struct task_struct *task)
206 {
207 struct mm_struct *mm = get_task_mm(task);
208 if (!mm)
209 return NULL;
210 down_read(&mm->mmap_sem);
211 task_lock(task);
212 if (task->mm != mm)
213 goto out;
214 if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
215 goto out;
216 task_unlock(task);
217 return mm;
218 out:
219 task_unlock(task);
220 up_read(&mm->mmap_sem);
221 mmput(mm);
222 return NULL;
223 }
224
225 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
226 {
227 int res = 0;
228 unsigned int len;
229 struct mm_struct *mm = get_task_mm(task);
230 if (!mm)
231 goto out;
232 if (!mm->arg_end)
233 goto out_mm; /* Shh! No looking before we're done */
234
235 len = mm->arg_end - mm->arg_start;
236
237 if (len > PAGE_SIZE)
238 len = PAGE_SIZE;
239
240 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
241
242 // If the nul at the end of args has been overwritten, then
243 // assume application is using setproctitle(3).
244 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
245 len = strnlen(buffer, res);
246 if (len < res) {
247 res = len;
248 } else {
249 len = mm->env_end - mm->env_start;
250 if (len > PAGE_SIZE - res)
251 len = PAGE_SIZE - res;
252 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
253 res = strnlen(buffer, res);
254 }
255 }
256 out_mm:
257 mmput(mm);
258 out:
259 return res;
260 }
261
262 static int proc_pid_auxv(struct task_struct *task, char *buffer)
263 {
264 int res = 0;
265 struct mm_struct *mm = get_task_mm(task);
266 if (mm) {
267 unsigned int nwords = 0;
268 do
269 nwords += 2;
270 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
271 res = nwords * sizeof(mm->saved_auxv[0]);
272 if (res > PAGE_SIZE)
273 res = PAGE_SIZE;
274 memcpy(buffer, mm->saved_auxv, res);
275 mmput(mm);
276 }
277 return res;
278 }
279
280
281 #ifdef CONFIG_KALLSYMS
282 /*
283 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
284 * Returns the resolved symbol. If that fails, simply return the address.
285 */
286 static int proc_pid_wchan(struct task_struct *task, char *buffer)
287 {
288 unsigned long wchan;
289 char symname[KSYM_NAME_LEN];
290
291 wchan = get_wchan(task);
292
293 if (lookup_symbol_name(wchan, symname) < 0)
294 return sprintf(buffer, "%lu", wchan);
295 else
296 return sprintf(buffer, "%s", symname);
297 }
298 #endif /* CONFIG_KALLSYMS */
299
300 #ifdef CONFIG_SCHEDSTATS
301 /*
302 * Provides /proc/PID/schedstat
303 */
304 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
305 {
306 return sprintf(buffer, "%llu %llu %lu\n",
307 task->sched_info.cpu_time,
308 task->sched_info.run_delay,
309 task->sched_info.pcount);
310 }
311 #endif
312
313 #ifdef CONFIG_LATENCYTOP
314 static int lstats_show_proc(struct seq_file *m, void *v)
315 {
316 int i;
317 struct inode *inode = m->private;
318 struct task_struct *task = get_proc_task(inode);
319
320 if (!task)
321 return -ESRCH;
322 seq_puts(m, "Latency Top version : v0.1\n");
323 for (i = 0; i < 32; i++) {
324 if (task->latency_record[i].backtrace[0]) {
325 int q;
326 seq_printf(m, "%i %li %li ",
327 task->latency_record[i].count,
328 task->latency_record[i].time,
329 task->latency_record[i].max);
330 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
331 char sym[KSYM_NAME_LEN];
332 char *c;
333 if (!task->latency_record[i].backtrace[q])
334 break;
335 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
336 break;
337 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
338 c = strchr(sym, '+');
339 if (c)
340 *c = 0;
341 seq_printf(m, "%s ", sym);
342 }
343 seq_printf(m, "\n");
344 }
345
346 }
347 put_task_struct(task);
348 return 0;
349 }
350
351 static int lstats_open(struct inode *inode, struct file *file)
352 {
353 return single_open(file, lstats_show_proc, inode);
354 }
355
356 static ssize_t lstats_write(struct file *file, const char __user *buf,
357 size_t count, loff_t *offs)
358 {
359 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
360
361 if (!task)
362 return -ESRCH;
363 clear_all_latency_tracing(task);
364 put_task_struct(task);
365
366 return count;
367 }
368
369 static const struct file_operations proc_lstats_operations = {
370 .open = lstats_open,
371 .read = seq_read,
372 .write = lstats_write,
373 .llseek = seq_lseek,
374 .release = single_release,
375 };
376
377 #endif
378
379 /* The badness from the OOM killer */
380 unsigned long badness(struct task_struct *p, unsigned long uptime);
381 static int proc_oom_score(struct task_struct *task, char *buffer)
382 {
383 unsigned long points;
384 struct timespec uptime;
385
386 do_posix_clock_monotonic_gettime(&uptime);
387 read_lock(&tasklist_lock);
388 points = badness(task, uptime.tv_sec);
389 read_unlock(&tasklist_lock);
390 return sprintf(buffer, "%lu\n", points);
391 }
392
393 struct limit_names {
394 char *name;
395 char *unit;
396 };
397
398 static const struct limit_names lnames[RLIM_NLIMITS] = {
399 [RLIMIT_CPU] = {"Max cpu time", "ms"},
400 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
401 [RLIMIT_DATA] = {"Max data size", "bytes"},
402 [RLIMIT_STACK] = {"Max stack size", "bytes"},
403 [RLIMIT_CORE] = {"Max core file size", "bytes"},
404 [RLIMIT_RSS] = {"Max resident set", "bytes"},
405 [RLIMIT_NPROC] = {"Max processes", "processes"},
406 [RLIMIT_NOFILE] = {"Max open files", "files"},
407 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
408 [RLIMIT_AS] = {"Max address space", "bytes"},
409 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
410 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
411 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
412 [RLIMIT_NICE] = {"Max nice priority", NULL},
413 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
414 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
415 };
416
417 /* Display limits for a process */
418 static int proc_pid_limits(struct task_struct *task, char *buffer)
419 {
420 unsigned int i;
421 int count = 0;
422 unsigned long flags;
423 char *bufptr = buffer;
424
425 struct rlimit rlim[RLIM_NLIMITS];
426
427 rcu_read_lock();
428 if (!lock_task_sighand(task,&flags)) {
429 rcu_read_unlock();
430 return 0;
431 }
432 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
433 unlock_task_sighand(task, &flags);
434 rcu_read_unlock();
435
436 /*
437 * print the file header
438 */
439 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
440 "Limit", "Soft Limit", "Hard Limit", "Units");
441
442 for (i = 0; i < RLIM_NLIMITS; i++) {
443 if (rlim[i].rlim_cur == RLIM_INFINITY)
444 count += sprintf(&bufptr[count], "%-25s %-20s ",
445 lnames[i].name, "unlimited");
446 else
447 count += sprintf(&bufptr[count], "%-25s %-20lu ",
448 lnames[i].name, rlim[i].rlim_cur);
449
450 if (rlim[i].rlim_max == RLIM_INFINITY)
451 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
452 else
453 count += sprintf(&bufptr[count], "%-20lu ",
454 rlim[i].rlim_max);
455
456 if (lnames[i].unit)
457 count += sprintf(&bufptr[count], "%-10s\n",
458 lnames[i].unit);
459 else
460 count += sprintf(&bufptr[count], "\n");
461 }
462
463 return count;
464 }
465
466 /************************************************************************/
467 /* Here the fs part begins */
468 /************************************************************************/
469
470 /* permission checks */
471 static int proc_fd_access_allowed(struct inode *inode)
472 {
473 struct task_struct *task;
474 int allowed = 0;
475 /* Allow access to a task's file descriptors if it is us or we
476 * may use ptrace attach to the process and find out that
477 * information.
478 */
479 task = get_proc_task(inode);
480 if (task) {
481 allowed = ptrace_may_attach(task);
482 put_task_struct(task);
483 }
484 return allowed;
485 }
486
487 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
488 {
489 int error;
490 struct inode *inode = dentry->d_inode;
491
492 if (attr->ia_valid & ATTR_MODE)
493 return -EPERM;
494
495 error = inode_change_ok(inode, attr);
496 if (!error)
497 error = inode_setattr(inode, attr);
498 return error;
499 }
500
501 static const struct inode_operations proc_def_inode_operations = {
502 .setattr = proc_setattr,
503 };
504
505 extern const struct seq_operations mounts_op;
506 struct proc_mounts {
507 struct seq_file m;
508 int event;
509 };
510
511 static int mounts_open(struct inode *inode, struct file *file)
512 {
513 struct task_struct *task = get_proc_task(inode);
514 struct nsproxy *nsp;
515 struct mnt_namespace *ns = NULL;
516 struct proc_mounts *p;
517 int ret = -EINVAL;
518
519 if (task) {
520 rcu_read_lock();
521 nsp = task_nsproxy(task);
522 if (nsp) {
523 ns = nsp->mnt_ns;
524 if (ns)
525 get_mnt_ns(ns);
526 }
527 rcu_read_unlock();
528
529 put_task_struct(task);
530 }
531
532 if (ns) {
533 ret = -ENOMEM;
534 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
535 if (p) {
536 file->private_data = &p->m;
537 ret = seq_open(file, &mounts_op);
538 if (!ret) {
539 p->m.private = ns;
540 p->event = ns->event;
541 return 0;
542 }
543 kfree(p);
544 }
545 put_mnt_ns(ns);
546 }
547 return ret;
548 }
549
550 static int mounts_release(struct inode *inode, struct file *file)
551 {
552 struct seq_file *m = file->private_data;
553 struct mnt_namespace *ns = m->private;
554 put_mnt_ns(ns);
555 return seq_release(inode, file);
556 }
557
558 static unsigned mounts_poll(struct file *file, poll_table *wait)
559 {
560 struct proc_mounts *p = file->private_data;
561 struct mnt_namespace *ns = p->m.private;
562 unsigned res = 0;
563
564 poll_wait(file, &ns->poll, wait);
565
566 spin_lock(&vfsmount_lock);
567 if (p->event != ns->event) {
568 p->event = ns->event;
569 res = POLLERR;
570 }
571 spin_unlock(&vfsmount_lock);
572
573 return res;
574 }
575
576 static const struct file_operations proc_mounts_operations = {
577 .open = mounts_open,
578 .read = seq_read,
579 .llseek = seq_lseek,
580 .release = mounts_release,
581 .poll = mounts_poll,
582 };
583
584 extern const struct seq_operations mountstats_op;
585 static int mountstats_open(struct inode *inode, struct file *file)
586 {
587 int ret = seq_open(file, &mountstats_op);
588
589 if (!ret) {
590 struct seq_file *m = file->private_data;
591 struct nsproxy *nsp;
592 struct mnt_namespace *mnt_ns = NULL;
593 struct task_struct *task = get_proc_task(inode);
594
595 if (task) {
596 rcu_read_lock();
597 nsp = task_nsproxy(task);
598 if (nsp) {
599 mnt_ns = nsp->mnt_ns;
600 if (mnt_ns)
601 get_mnt_ns(mnt_ns);
602 }
603 rcu_read_unlock();
604
605 put_task_struct(task);
606 }
607
608 if (mnt_ns)
609 m->private = mnt_ns;
610 else {
611 seq_release(inode, file);
612 ret = -EINVAL;
613 }
614 }
615 return ret;
616 }
617
618 static const struct file_operations proc_mountstats_operations = {
619 .open = mountstats_open,
620 .read = seq_read,
621 .llseek = seq_lseek,
622 .release = mounts_release,
623 };
624
625 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
626
627 static ssize_t proc_info_read(struct file * file, char __user * buf,
628 size_t count, loff_t *ppos)
629 {
630 struct inode * inode = file->f_path.dentry->d_inode;
631 unsigned long page;
632 ssize_t length;
633 struct task_struct *task = get_proc_task(inode);
634
635 length = -ESRCH;
636 if (!task)
637 goto out_no_task;
638
639 if (count > PROC_BLOCK_SIZE)
640 count = PROC_BLOCK_SIZE;
641
642 length = -ENOMEM;
643 if (!(page = __get_free_page(GFP_TEMPORARY)))
644 goto out;
645
646 length = PROC_I(inode)->op.proc_read(task, (char*)page);
647
648 if (length >= 0)
649 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
650 free_page(page);
651 out:
652 put_task_struct(task);
653 out_no_task:
654 return length;
655 }
656
657 static const struct file_operations proc_info_file_operations = {
658 .read = proc_info_read,
659 };
660
661 static int proc_single_show(struct seq_file *m, void *v)
662 {
663 struct inode *inode = m->private;
664 struct pid_namespace *ns;
665 struct pid *pid;
666 struct task_struct *task;
667 int ret;
668
669 ns = inode->i_sb->s_fs_info;
670 pid = proc_pid(inode);
671 task = get_pid_task(pid, PIDTYPE_PID);
672 if (!task)
673 return -ESRCH;
674
675 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
676
677 put_task_struct(task);
678 return ret;
679 }
680
681 static int proc_single_open(struct inode *inode, struct file *filp)
682 {
683 int ret;
684 ret = single_open(filp, proc_single_show, NULL);
685 if (!ret) {
686 struct seq_file *m = filp->private_data;
687
688 m->private = inode;
689 }
690 return ret;
691 }
692
693 static const struct file_operations proc_single_file_operations = {
694 .open = proc_single_open,
695 .read = seq_read,
696 .llseek = seq_lseek,
697 .release = single_release,
698 };
699
700 static int mem_open(struct inode* inode, struct file* file)
701 {
702 file->private_data = (void*)((long)current->self_exec_id);
703 return 0;
704 }
705
706 static ssize_t mem_read(struct file * file, char __user * buf,
707 size_t count, loff_t *ppos)
708 {
709 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
710 char *page;
711 unsigned long src = *ppos;
712 int ret = -ESRCH;
713 struct mm_struct *mm;
714
715 if (!task)
716 goto out_no_task;
717
718 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
719 goto out;
720
721 ret = -ENOMEM;
722 page = (char *)__get_free_page(GFP_TEMPORARY);
723 if (!page)
724 goto out;
725
726 ret = 0;
727
728 mm = get_task_mm(task);
729 if (!mm)
730 goto out_free;
731
732 ret = -EIO;
733
734 if (file->private_data != (void*)((long)current->self_exec_id))
735 goto out_put;
736
737 ret = 0;
738
739 while (count > 0) {
740 int this_len, retval;
741
742 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
743 retval = access_process_vm(task, src, page, this_len, 0);
744 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
745 if (!ret)
746 ret = -EIO;
747 break;
748 }
749
750 if (copy_to_user(buf, page, retval)) {
751 ret = -EFAULT;
752 break;
753 }
754
755 ret += retval;
756 src += retval;
757 buf += retval;
758 count -= retval;
759 }
760 *ppos = src;
761
762 out_put:
763 mmput(mm);
764 out_free:
765 free_page((unsigned long) page);
766 out:
767 put_task_struct(task);
768 out_no_task:
769 return ret;
770 }
771
772 #define mem_write NULL
773
774 #ifndef mem_write
775 /* This is a security hazard */
776 static ssize_t mem_write(struct file * file, const char __user *buf,
777 size_t count, loff_t *ppos)
778 {
779 int copied;
780 char *page;
781 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
782 unsigned long dst = *ppos;
783
784 copied = -ESRCH;
785 if (!task)
786 goto out_no_task;
787
788 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
789 goto out;
790
791 copied = -ENOMEM;
792 page = (char *)__get_free_page(GFP_TEMPORARY);
793 if (!page)
794 goto out;
795
796 copied = 0;
797 while (count > 0) {
798 int this_len, retval;
799
800 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
801 if (copy_from_user(page, buf, this_len)) {
802 copied = -EFAULT;
803 break;
804 }
805 retval = access_process_vm(task, dst, page, this_len, 1);
806 if (!retval) {
807 if (!copied)
808 copied = -EIO;
809 break;
810 }
811 copied += retval;
812 buf += retval;
813 dst += retval;
814 count -= retval;
815 }
816 *ppos = dst;
817 free_page((unsigned long) page);
818 out:
819 put_task_struct(task);
820 out_no_task:
821 return copied;
822 }
823 #endif
824
825 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
826 {
827 switch (orig) {
828 case 0:
829 file->f_pos = offset;
830 break;
831 case 1:
832 file->f_pos += offset;
833 break;
834 default:
835 return -EINVAL;
836 }
837 force_successful_syscall_return();
838 return file->f_pos;
839 }
840
841 static const struct file_operations proc_mem_operations = {
842 .llseek = mem_lseek,
843 .read = mem_read,
844 .write = mem_write,
845 .open = mem_open,
846 };
847
848 static ssize_t environ_read(struct file *file, char __user *buf,
849 size_t count, loff_t *ppos)
850 {
851 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
852 char *page;
853 unsigned long src = *ppos;
854 int ret = -ESRCH;
855 struct mm_struct *mm;
856
857 if (!task)
858 goto out_no_task;
859
860 if (!ptrace_may_attach(task))
861 goto out;
862
863 ret = -ENOMEM;
864 page = (char *)__get_free_page(GFP_TEMPORARY);
865 if (!page)
866 goto out;
867
868 ret = 0;
869
870 mm = get_task_mm(task);
871 if (!mm)
872 goto out_free;
873
874 while (count > 0) {
875 int this_len, retval, max_len;
876
877 this_len = mm->env_end - (mm->env_start + src);
878
879 if (this_len <= 0)
880 break;
881
882 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
883 this_len = (this_len > max_len) ? max_len : this_len;
884
885 retval = access_process_vm(task, (mm->env_start + src),
886 page, this_len, 0);
887
888 if (retval <= 0) {
889 ret = retval;
890 break;
891 }
892
893 if (copy_to_user(buf, page, retval)) {
894 ret = -EFAULT;
895 break;
896 }
897
898 ret += retval;
899 src += retval;
900 buf += retval;
901 count -= retval;
902 }
903 *ppos = src;
904
905 mmput(mm);
906 out_free:
907 free_page((unsigned long) page);
908 out:
909 put_task_struct(task);
910 out_no_task:
911 return ret;
912 }
913
914 static const struct file_operations proc_environ_operations = {
915 .read = environ_read,
916 };
917
918 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
919 size_t count, loff_t *ppos)
920 {
921 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
922 char buffer[PROC_NUMBUF];
923 size_t len;
924 int oom_adjust;
925
926 if (!task)
927 return -ESRCH;
928 oom_adjust = task->oomkilladj;
929 put_task_struct(task);
930
931 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
932
933 return simple_read_from_buffer(buf, count, ppos, buffer, len);
934 }
935
936 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
937 size_t count, loff_t *ppos)
938 {
939 struct task_struct *task;
940 char buffer[PROC_NUMBUF], *end;
941 int oom_adjust;
942
943 memset(buffer, 0, sizeof(buffer));
944 if (count > sizeof(buffer) - 1)
945 count = sizeof(buffer) - 1;
946 if (copy_from_user(buffer, buf, count))
947 return -EFAULT;
948 oom_adjust = simple_strtol(buffer, &end, 0);
949 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
950 oom_adjust != OOM_DISABLE)
951 return -EINVAL;
952 if (*end == '\n')
953 end++;
954 task = get_proc_task(file->f_path.dentry->d_inode);
955 if (!task)
956 return -ESRCH;
957 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
958 put_task_struct(task);
959 return -EACCES;
960 }
961 task->oomkilladj = oom_adjust;
962 put_task_struct(task);
963 if (end - buffer == 0)
964 return -EIO;
965 return end - buffer;
966 }
967
968 static const struct file_operations proc_oom_adjust_operations = {
969 .read = oom_adjust_read,
970 .write = oom_adjust_write,
971 };
972
973 #ifdef CONFIG_AUDITSYSCALL
974 #define TMPBUFLEN 21
975 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
976 size_t count, loff_t *ppos)
977 {
978 struct inode * inode = file->f_path.dentry->d_inode;
979 struct task_struct *task = get_proc_task(inode);
980 ssize_t length;
981 char tmpbuf[TMPBUFLEN];
982
983 if (!task)
984 return -ESRCH;
985 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
986 audit_get_loginuid(task));
987 put_task_struct(task);
988 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
989 }
990
991 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
992 size_t count, loff_t *ppos)
993 {
994 struct inode * inode = file->f_path.dentry->d_inode;
995 char *page, *tmp;
996 ssize_t length;
997 uid_t loginuid;
998
999 if (!capable(CAP_AUDIT_CONTROL))
1000 return -EPERM;
1001
1002 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1003 return -EPERM;
1004
1005 if (count >= PAGE_SIZE)
1006 count = PAGE_SIZE - 1;
1007
1008 if (*ppos != 0) {
1009 /* No partial writes. */
1010 return -EINVAL;
1011 }
1012 page = (char*)__get_free_page(GFP_TEMPORARY);
1013 if (!page)
1014 return -ENOMEM;
1015 length = -EFAULT;
1016 if (copy_from_user(page, buf, count))
1017 goto out_free_page;
1018
1019 page[count] = '\0';
1020 loginuid = simple_strtoul(page, &tmp, 10);
1021 if (tmp == page) {
1022 length = -EINVAL;
1023 goto out_free_page;
1024
1025 }
1026 length = audit_set_loginuid(current, loginuid);
1027 if (likely(length == 0))
1028 length = count;
1029
1030 out_free_page:
1031 free_page((unsigned long) page);
1032 return length;
1033 }
1034
1035 static const struct file_operations proc_loginuid_operations = {
1036 .read = proc_loginuid_read,
1037 .write = proc_loginuid_write,
1038 };
1039 #endif
1040
1041 #ifdef CONFIG_FAULT_INJECTION
1042 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1043 size_t count, loff_t *ppos)
1044 {
1045 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1046 char buffer[PROC_NUMBUF];
1047 size_t len;
1048 int make_it_fail;
1049
1050 if (!task)
1051 return -ESRCH;
1052 make_it_fail = task->make_it_fail;
1053 put_task_struct(task);
1054
1055 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1056
1057 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1058 }
1059
1060 static ssize_t proc_fault_inject_write(struct file * file,
1061 const char __user * buf, size_t count, loff_t *ppos)
1062 {
1063 struct task_struct *task;
1064 char buffer[PROC_NUMBUF], *end;
1065 int make_it_fail;
1066
1067 if (!capable(CAP_SYS_RESOURCE))
1068 return -EPERM;
1069 memset(buffer, 0, sizeof(buffer));
1070 if (count > sizeof(buffer) - 1)
1071 count = sizeof(buffer) - 1;
1072 if (copy_from_user(buffer, buf, count))
1073 return -EFAULT;
1074 make_it_fail = simple_strtol(buffer, &end, 0);
1075 if (*end == '\n')
1076 end++;
1077 task = get_proc_task(file->f_dentry->d_inode);
1078 if (!task)
1079 return -ESRCH;
1080 task->make_it_fail = make_it_fail;
1081 put_task_struct(task);
1082 if (end - buffer == 0)
1083 return -EIO;
1084 return end - buffer;
1085 }
1086
1087 static const struct file_operations proc_fault_inject_operations = {
1088 .read = proc_fault_inject_read,
1089 .write = proc_fault_inject_write,
1090 };
1091 #endif
1092
1093
1094 #ifdef CONFIG_SCHED_DEBUG
1095 /*
1096 * Print out various scheduling related per-task fields:
1097 */
1098 static int sched_show(struct seq_file *m, void *v)
1099 {
1100 struct inode *inode = m->private;
1101 struct task_struct *p;
1102
1103 WARN_ON(!inode);
1104
1105 p = get_proc_task(inode);
1106 if (!p)
1107 return -ESRCH;
1108 proc_sched_show_task(p, m);
1109
1110 put_task_struct(p);
1111
1112 return 0;
1113 }
1114
1115 static ssize_t
1116 sched_write(struct file *file, const char __user *buf,
1117 size_t count, loff_t *offset)
1118 {
1119 struct inode *inode = file->f_path.dentry->d_inode;
1120 struct task_struct *p;
1121
1122 WARN_ON(!inode);
1123
1124 p = get_proc_task(inode);
1125 if (!p)
1126 return -ESRCH;
1127 proc_sched_set_task(p);
1128
1129 put_task_struct(p);
1130
1131 return count;
1132 }
1133
1134 static int sched_open(struct inode *inode, struct file *filp)
1135 {
1136 int ret;
1137
1138 ret = single_open(filp, sched_show, NULL);
1139 if (!ret) {
1140 struct seq_file *m = filp->private_data;
1141
1142 m->private = inode;
1143 }
1144 return ret;
1145 }
1146
1147 static const struct file_operations proc_pid_sched_operations = {
1148 .open = sched_open,
1149 .read = seq_read,
1150 .write = sched_write,
1151 .llseek = seq_lseek,
1152 .release = single_release,
1153 };
1154
1155 #endif
1156
1157 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1158 {
1159 struct inode *inode = dentry->d_inode;
1160 int error = -EACCES;
1161
1162 /* We don't need a base pointer in the /proc filesystem */
1163 path_put(&nd->path);
1164
1165 /* Are we allowed to snoop on the tasks file descriptors? */
1166 if (!proc_fd_access_allowed(inode))
1167 goto out;
1168
1169 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1170 nd->last_type = LAST_BIND;
1171 out:
1172 return ERR_PTR(error);
1173 }
1174
1175 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1176 {
1177 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1178 char *pathname;
1179 int len;
1180
1181 if (!tmp)
1182 return -ENOMEM;
1183
1184 pathname = d_path(path, tmp, PAGE_SIZE);
1185 len = PTR_ERR(pathname);
1186 if (IS_ERR(pathname))
1187 goto out;
1188 len = tmp + PAGE_SIZE - 1 - pathname;
1189
1190 if (len > buflen)
1191 len = buflen;
1192 if (copy_to_user(buffer, pathname, len))
1193 len = -EFAULT;
1194 out:
1195 free_page((unsigned long)tmp);
1196 return len;
1197 }
1198
1199 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1200 {
1201 int error = -EACCES;
1202 struct inode *inode = dentry->d_inode;
1203 struct path path;
1204
1205 /* Are we allowed to snoop on the tasks file descriptors? */
1206 if (!proc_fd_access_allowed(inode))
1207 goto out;
1208
1209 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1210 if (error)
1211 goto out;
1212
1213 error = do_proc_readlink(&path, buffer, buflen);
1214 path_put(&path);
1215 out:
1216 return error;
1217 }
1218
1219 static const struct inode_operations proc_pid_link_inode_operations = {
1220 .readlink = proc_pid_readlink,
1221 .follow_link = proc_pid_follow_link,
1222 .setattr = proc_setattr,
1223 };
1224
1225
1226 /* building an inode */
1227
1228 static int task_dumpable(struct task_struct *task)
1229 {
1230 int dumpable = 0;
1231 struct mm_struct *mm;
1232
1233 task_lock(task);
1234 mm = task->mm;
1235 if (mm)
1236 dumpable = get_dumpable(mm);
1237 task_unlock(task);
1238 if(dumpable == 1)
1239 return 1;
1240 return 0;
1241 }
1242
1243
1244 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1245 {
1246 struct inode * inode;
1247 struct proc_inode *ei;
1248
1249 /* We need a new inode */
1250
1251 inode = new_inode(sb);
1252 if (!inode)
1253 goto out;
1254
1255 /* Common stuff */
1256 ei = PROC_I(inode);
1257 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1258 inode->i_op = &proc_def_inode_operations;
1259
1260 /*
1261 * grab the reference to task.
1262 */
1263 ei->pid = get_task_pid(task, PIDTYPE_PID);
1264 if (!ei->pid)
1265 goto out_unlock;
1266
1267 inode->i_uid = 0;
1268 inode->i_gid = 0;
1269 if (task_dumpable(task)) {
1270 inode->i_uid = task->euid;
1271 inode->i_gid = task->egid;
1272 }
1273 security_task_to_inode(task, inode);
1274
1275 out:
1276 return inode;
1277
1278 out_unlock:
1279 iput(inode);
1280 return NULL;
1281 }
1282
1283 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1284 {
1285 struct inode *inode = dentry->d_inode;
1286 struct task_struct *task;
1287 generic_fillattr(inode, stat);
1288
1289 rcu_read_lock();
1290 stat->uid = 0;
1291 stat->gid = 0;
1292 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1293 if (task) {
1294 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1295 task_dumpable(task)) {
1296 stat->uid = task->euid;
1297 stat->gid = task->egid;
1298 }
1299 }
1300 rcu_read_unlock();
1301 return 0;
1302 }
1303
1304 /* dentry stuff */
1305
1306 /*
1307 * Exceptional case: normally we are not allowed to unhash a busy
1308 * directory. In this case, however, we can do it - no aliasing problems
1309 * due to the way we treat inodes.
1310 *
1311 * Rewrite the inode's ownerships here because the owning task may have
1312 * performed a setuid(), etc.
1313 *
1314 * Before the /proc/pid/status file was created the only way to read
1315 * the effective uid of a /process was to stat /proc/pid. Reading
1316 * /proc/pid/status is slow enough that procps and other packages
1317 * kept stating /proc/pid. To keep the rules in /proc simple I have
1318 * made this apply to all per process world readable and executable
1319 * directories.
1320 */
1321 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1322 {
1323 struct inode *inode = dentry->d_inode;
1324 struct task_struct *task = get_proc_task(inode);
1325 if (task) {
1326 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1327 task_dumpable(task)) {
1328 inode->i_uid = task->euid;
1329 inode->i_gid = task->egid;
1330 } else {
1331 inode->i_uid = 0;
1332 inode->i_gid = 0;
1333 }
1334 inode->i_mode &= ~(S_ISUID | S_ISGID);
1335 security_task_to_inode(task, inode);
1336 put_task_struct(task);
1337 return 1;
1338 }
1339 d_drop(dentry);
1340 return 0;
1341 }
1342
1343 static int pid_delete_dentry(struct dentry * dentry)
1344 {
1345 /* Is the task we represent dead?
1346 * If so, then don't put the dentry on the lru list,
1347 * kill it immediately.
1348 */
1349 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1350 }
1351
1352 static struct dentry_operations pid_dentry_operations =
1353 {
1354 .d_revalidate = pid_revalidate,
1355 .d_delete = pid_delete_dentry,
1356 };
1357
1358 /* Lookups */
1359
1360 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1361 struct task_struct *, const void *);
1362
1363 /*
1364 * Fill a directory entry.
1365 *
1366 * If possible create the dcache entry and derive our inode number and
1367 * file type from dcache entry.
1368 *
1369 * Since all of the proc inode numbers are dynamically generated, the inode
1370 * numbers do not exist until the inode is cache. This means creating the
1371 * the dcache entry in readdir is necessary to keep the inode numbers
1372 * reported by readdir in sync with the inode numbers reported
1373 * by stat.
1374 */
1375 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1376 char *name, int len,
1377 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1378 {
1379 struct dentry *child, *dir = filp->f_path.dentry;
1380 struct inode *inode;
1381 struct qstr qname;
1382 ino_t ino = 0;
1383 unsigned type = DT_UNKNOWN;
1384
1385 qname.name = name;
1386 qname.len = len;
1387 qname.hash = full_name_hash(name, len);
1388
1389 child = d_lookup(dir, &qname);
1390 if (!child) {
1391 struct dentry *new;
1392 new = d_alloc(dir, &qname);
1393 if (new) {
1394 child = instantiate(dir->d_inode, new, task, ptr);
1395 if (child)
1396 dput(new);
1397 else
1398 child = new;
1399 }
1400 }
1401 if (!child || IS_ERR(child) || !child->d_inode)
1402 goto end_instantiate;
1403 inode = child->d_inode;
1404 if (inode) {
1405 ino = inode->i_ino;
1406 type = inode->i_mode >> 12;
1407 }
1408 dput(child);
1409 end_instantiate:
1410 if (!ino)
1411 ino = find_inode_number(dir, &qname);
1412 if (!ino)
1413 ino = 1;
1414 return filldir(dirent, name, len, filp->f_pos, ino, type);
1415 }
1416
1417 static unsigned name_to_int(struct dentry *dentry)
1418 {
1419 const char *name = dentry->d_name.name;
1420 int len = dentry->d_name.len;
1421 unsigned n = 0;
1422
1423 if (len > 1 && *name == '0')
1424 goto out;
1425 while (len-- > 0) {
1426 unsigned c = *name++ - '0';
1427 if (c > 9)
1428 goto out;
1429 if (n >= (~0U-9)/10)
1430 goto out;
1431 n *= 10;
1432 n += c;
1433 }
1434 return n;
1435 out:
1436 return ~0U;
1437 }
1438
1439 #define PROC_FDINFO_MAX 64
1440
1441 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1442 {
1443 struct task_struct *task = get_proc_task(inode);
1444 struct files_struct *files = NULL;
1445 struct file *file;
1446 int fd = proc_fd(inode);
1447
1448 if (task) {
1449 files = get_files_struct(task);
1450 put_task_struct(task);
1451 }
1452 if (files) {
1453 /*
1454 * We are not taking a ref to the file structure, so we must
1455 * hold ->file_lock.
1456 */
1457 spin_lock(&files->file_lock);
1458 file = fcheck_files(files, fd);
1459 if (file) {
1460 if (path) {
1461 *path = file->f_path;
1462 path_get(&file->f_path);
1463 }
1464 if (info)
1465 snprintf(info, PROC_FDINFO_MAX,
1466 "pos:\t%lli\n"
1467 "flags:\t0%o\n",
1468 (long long) file->f_pos,
1469 file->f_flags);
1470 spin_unlock(&files->file_lock);
1471 put_files_struct(files);
1472 return 0;
1473 }
1474 spin_unlock(&files->file_lock);
1475 put_files_struct(files);
1476 }
1477 return -ENOENT;
1478 }
1479
1480 static int proc_fd_link(struct inode *inode, struct path *path)
1481 {
1482 return proc_fd_info(inode, path, NULL);
1483 }
1484
1485 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1486 {
1487 struct inode *inode = dentry->d_inode;
1488 struct task_struct *task = get_proc_task(inode);
1489 int fd = proc_fd(inode);
1490 struct files_struct *files;
1491
1492 if (task) {
1493 files = get_files_struct(task);
1494 if (files) {
1495 rcu_read_lock();
1496 if (fcheck_files(files, fd)) {
1497 rcu_read_unlock();
1498 put_files_struct(files);
1499 if (task_dumpable(task)) {
1500 inode->i_uid = task->euid;
1501 inode->i_gid = task->egid;
1502 } else {
1503 inode->i_uid = 0;
1504 inode->i_gid = 0;
1505 }
1506 inode->i_mode &= ~(S_ISUID | S_ISGID);
1507 security_task_to_inode(task, inode);
1508 put_task_struct(task);
1509 return 1;
1510 }
1511 rcu_read_unlock();
1512 put_files_struct(files);
1513 }
1514 put_task_struct(task);
1515 }
1516 d_drop(dentry);
1517 return 0;
1518 }
1519
1520 static struct dentry_operations tid_fd_dentry_operations =
1521 {
1522 .d_revalidate = tid_fd_revalidate,
1523 .d_delete = pid_delete_dentry,
1524 };
1525
1526 static struct dentry *proc_fd_instantiate(struct inode *dir,
1527 struct dentry *dentry, struct task_struct *task, const void *ptr)
1528 {
1529 unsigned fd = *(const unsigned *)ptr;
1530 struct file *file;
1531 struct files_struct *files;
1532 struct inode *inode;
1533 struct proc_inode *ei;
1534 struct dentry *error = ERR_PTR(-ENOENT);
1535
1536 inode = proc_pid_make_inode(dir->i_sb, task);
1537 if (!inode)
1538 goto out;
1539 ei = PROC_I(inode);
1540 ei->fd = fd;
1541 files = get_files_struct(task);
1542 if (!files)
1543 goto out_iput;
1544 inode->i_mode = S_IFLNK;
1545
1546 /*
1547 * We are not taking a ref to the file structure, so we must
1548 * hold ->file_lock.
1549 */
1550 spin_lock(&files->file_lock);
1551 file = fcheck_files(files, fd);
1552 if (!file)
1553 goto out_unlock;
1554 if (file->f_mode & 1)
1555 inode->i_mode |= S_IRUSR | S_IXUSR;
1556 if (file->f_mode & 2)
1557 inode->i_mode |= S_IWUSR | S_IXUSR;
1558 spin_unlock(&files->file_lock);
1559 put_files_struct(files);
1560
1561 inode->i_op = &proc_pid_link_inode_operations;
1562 inode->i_size = 64;
1563 ei->op.proc_get_link = proc_fd_link;
1564 dentry->d_op = &tid_fd_dentry_operations;
1565 d_add(dentry, inode);
1566 /* Close the race of the process dying before we return the dentry */
1567 if (tid_fd_revalidate(dentry, NULL))
1568 error = NULL;
1569
1570 out:
1571 return error;
1572 out_unlock:
1573 spin_unlock(&files->file_lock);
1574 put_files_struct(files);
1575 out_iput:
1576 iput(inode);
1577 goto out;
1578 }
1579
1580 static struct dentry *proc_lookupfd_common(struct inode *dir,
1581 struct dentry *dentry,
1582 instantiate_t instantiate)
1583 {
1584 struct task_struct *task = get_proc_task(dir);
1585 unsigned fd = name_to_int(dentry);
1586 struct dentry *result = ERR_PTR(-ENOENT);
1587
1588 if (!task)
1589 goto out_no_task;
1590 if (fd == ~0U)
1591 goto out;
1592
1593 result = instantiate(dir, dentry, task, &fd);
1594 out:
1595 put_task_struct(task);
1596 out_no_task:
1597 return result;
1598 }
1599
1600 static int proc_readfd_common(struct file * filp, void * dirent,
1601 filldir_t filldir, instantiate_t instantiate)
1602 {
1603 struct dentry *dentry = filp->f_path.dentry;
1604 struct inode *inode = dentry->d_inode;
1605 struct task_struct *p = get_proc_task(inode);
1606 unsigned int fd, ino;
1607 int retval;
1608 struct files_struct * files;
1609 struct fdtable *fdt;
1610
1611 retval = -ENOENT;
1612 if (!p)
1613 goto out_no_task;
1614 retval = 0;
1615
1616 fd = filp->f_pos;
1617 switch (fd) {
1618 case 0:
1619 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1620 goto out;
1621 filp->f_pos++;
1622 case 1:
1623 ino = parent_ino(dentry);
1624 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1625 goto out;
1626 filp->f_pos++;
1627 default:
1628 files = get_files_struct(p);
1629 if (!files)
1630 goto out;
1631 rcu_read_lock();
1632 fdt = files_fdtable(files);
1633 for (fd = filp->f_pos-2;
1634 fd < fdt->max_fds;
1635 fd++, filp->f_pos++) {
1636 char name[PROC_NUMBUF];
1637 int len;
1638
1639 if (!fcheck_files(files, fd))
1640 continue;
1641 rcu_read_unlock();
1642
1643 len = snprintf(name, sizeof(name), "%d", fd);
1644 if (proc_fill_cache(filp, dirent, filldir,
1645 name, len, instantiate,
1646 p, &fd) < 0) {
1647 rcu_read_lock();
1648 break;
1649 }
1650 rcu_read_lock();
1651 }
1652 rcu_read_unlock();
1653 put_files_struct(files);
1654 }
1655 out:
1656 put_task_struct(p);
1657 out_no_task:
1658 return retval;
1659 }
1660
1661 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1662 struct nameidata *nd)
1663 {
1664 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1665 }
1666
1667 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1668 {
1669 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1670 }
1671
1672 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1673 size_t len, loff_t *ppos)
1674 {
1675 char tmp[PROC_FDINFO_MAX];
1676 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1677 if (!err)
1678 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1679 return err;
1680 }
1681
1682 static const struct file_operations proc_fdinfo_file_operations = {
1683 .open = nonseekable_open,
1684 .read = proc_fdinfo_read,
1685 };
1686
1687 static const struct file_operations proc_fd_operations = {
1688 .read = generic_read_dir,
1689 .readdir = proc_readfd,
1690 };
1691
1692 /*
1693 * /proc/pid/fd needs a special permission handler so that a process can still
1694 * access /proc/self/fd after it has executed a setuid().
1695 */
1696 static int proc_fd_permission(struct inode *inode, int mask,
1697 struct nameidata *nd)
1698 {
1699 int rv;
1700
1701 rv = generic_permission(inode, mask, NULL);
1702 if (rv == 0)
1703 return 0;
1704 if (task_pid(current) == proc_pid(inode))
1705 rv = 0;
1706 return rv;
1707 }
1708
1709 /*
1710 * proc directories can do almost nothing..
1711 */
1712 static const struct inode_operations proc_fd_inode_operations = {
1713 .lookup = proc_lookupfd,
1714 .permission = proc_fd_permission,
1715 .setattr = proc_setattr,
1716 };
1717
1718 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1719 struct dentry *dentry, struct task_struct *task, const void *ptr)
1720 {
1721 unsigned fd = *(unsigned *)ptr;
1722 struct inode *inode;
1723 struct proc_inode *ei;
1724 struct dentry *error = ERR_PTR(-ENOENT);
1725
1726 inode = proc_pid_make_inode(dir->i_sb, task);
1727 if (!inode)
1728 goto out;
1729 ei = PROC_I(inode);
1730 ei->fd = fd;
1731 inode->i_mode = S_IFREG | S_IRUSR;
1732 inode->i_fop = &proc_fdinfo_file_operations;
1733 dentry->d_op = &tid_fd_dentry_operations;
1734 d_add(dentry, inode);
1735 /* Close the race of the process dying before we return the dentry */
1736 if (tid_fd_revalidate(dentry, NULL))
1737 error = NULL;
1738
1739 out:
1740 return error;
1741 }
1742
1743 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1744 struct dentry *dentry,
1745 struct nameidata *nd)
1746 {
1747 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1748 }
1749
1750 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1751 {
1752 return proc_readfd_common(filp, dirent, filldir,
1753 proc_fdinfo_instantiate);
1754 }
1755
1756 static const struct file_operations proc_fdinfo_operations = {
1757 .read = generic_read_dir,
1758 .readdir = proc_readfdinfo,
1759 };
1760
1761 /*
1762 * proc directories can do almost nothing..
1763 */
1764 static const struct inode_operations proc_fdinfo_inode_operations = {
1765 .lookup = proc_lookupfdinfo,
1766 .setattr = proc_setattr,
1767 };
1768
1769
1770 static struct dentry *proc_pident_instantiate(struct inode *dir,
1771 struct dentry *dentry, struct task_struct *task, const void *ptr)
1772 {
1773 const struct pid_entry *p = ptr;
1774 struct inode *inode;
1775 struct proc_inode *ei;
1776 struct dentry *error = ERR_PTR(-EINVAL);
1777
1778 inode = proc_pid_make_inode(dir->i_sb, task);
1779 if (!inode)
1780 goto out;
1781
1782 ei = PROC_I(inode);
1783 inode->i_mode = p->mode;
1784 if (S_ISDIR(inode->i_mode))
1785 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1786 if (p->iop)
1787 inode->i_op = p->iop;
1788 if (p->fop)
1789 inode->i_fop = p->fop;
1790 ei->op = p->op;
1791 dentry->d_op = &pid_dentry_operations;
1792 d_add(dentry, inode);
1793 /* Close the race of the process dying before we return the dentry */
1794 if (pid_revalidate(dentry, NULL))
1795 error = NULL;
1796 out:
1797 return error;
1798 }
1799
1800 static struct dentry *proc_pident_lookup(struct inode *dir,
1801 struct dentry *dentry,
1802 const struct pid_entry *ents,
1803 unsigned int nents)
1804 {
1805 struct inode *inode;
1806 struct dentry *error;
1807 struct task_struct *task = get_proc_task(dir);
1808 const struct pid_entry *p, *last;
1809
1810 error = ERR_PTR(-ENOENT);
1811 inode = NULL;
1812
1813 if (!task)
1814 goto out_no_task;
1815
1816 /*
1817 * Yes, it does not scale. And it should not. Don't add
1818 * new entries into /proc/<tgid>/ without very good reasons.
1819 */
1820 last = &ents[nents - 1];
1821 for (p = ents; p <= last; p++) {
1822 if (p->len != dentry->d_name.len)
1823 continue;
1824 if (!memcmp(dentry->d_name.name, p->name, p->len))
1825 break;
1826 }
1827 if (p > last)
1828 goto out;
1829
1830 error = proc_pident_instantiate(dir, dentry, task, p);
1831 out:
1832 put_task_struct(task);
1833 out_no_task:
1834 return error;
1835 }
1836
1837 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1838 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1839 {
1840 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1841 proc_pident_instantiate, task, p);
1842 }
1843
1844 static int proc_pident_readdir(struct file *filp,
1845 void *dirent, filldir_t filldir,
1846 const struct pid_entry *ents, unsigned int nents)
1847 {
1848 int i;
1849 struct dentry *dentry = filp->f_path.dentry;
1850 struct inode *inode = dentry->d_inode;
1851 struct task_struct *task = get_proc_task(inode);
1852 const struct pid_entry *p, *last;
1853 ino_t ino;
1854 int ret;
1855
1856 ret = -ENOENT;
1857 if (!task)
1858 goto out_no_task;
1859
1860 ret = 0;
1861 i = filp->f_pos;
1862 switch (i) {
1863 case 0:
1864 ino = inode->i_ino;
1865 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1866 goto out;
1867 i++;
1868 filp->f_pos++;
1869 /* fall through */
1870 case 1:
1871 ino = parent_ino(dentry);
1872 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1873 goto out;
1874 i++;
1875 filp->f_pos++;
1876 /* fall through */
1877 default:
1878 i -= 2;
1879 if (i >= nents) {
1880 ret = 1;
1881 goto out;
1882 }
1883 p = ents + i;
1884 last = &ents[nents - 1];
1885 while (p <= last) {
1886 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1887 goto out;
1888 filp->f_pos++;
1889 p++;
1890 }
1891 }
1892
1893 ret = 1;
1894 out:
1895 put_task_struct(task);
1896 out_no_task:
1897 return ret;
1898 }
1899
1900 #ifdef CONFIG_SECURITY
1901 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1902 size_t count, loff_t *ppos)
1903 {
1904 struct inode * inode = file->f_path.dentry->d_inode;
1905 char *p = NULL;
1906 ssize_t length;
1907 struct task_struct *task = get_proc_task(inode);
1908
1909 if (!task)
1910 return -ESRCH;
1911
1912 length = security_getprocattr(task,
1913 (char*)file->f_path.dentry->d_name.name,
1914 &p);
1915 put_task_struct(task);
1916 if (length > 0)
1917 length = simple_read_from_buffer(buf, count, ppos, p, length);
1918 kfree(p);
1919 return length;
1920 }
1921
1922 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1923 size_t count, loff_t *ppos)
1924 {
1925 struct inode * inode = file->f_path.dentry->d_inode;
1926 char *page;
1927 ssize_t length;
1928 struct task_struct *task = get_proc_task(inode);
1929
1930 length = -ESRCH;
1931 if (!task)
1932 goto out_no_task;
1933 if (count > PAGE_SIZE)
1934 count = PAGE_SIZE;
1935
1936 /* No partial writes. */
1937 length = -EINVAL;
1938 if (*ppos != 0)
1939 goto out;
1940
1941 length = -ENOMEM;
1942 page = (char*)__get_free_page(GFP_TEMPORARY);
1943 if (!page)
1944 goto out;
1945
1946 length = -EFAULT;
1947 if (copy_from_user(page, buf, count))
1948 goto out_free;
1949
1950 length = security_setprocattr(task,
1951 (char*)file->f_path.dentry->d_name.name,
1952 (void*)page, count);
1953 out_free:
1954 free_page((unsigned long) page);
1955 out:
1956 put_task_struct(task);
1957 out_no_task:
1958 return length;
1959 }
1960
1961 static const struct file_operations proc_pid_attr_operations = {
1962 .read = proc_pid_attr_read,
1963 .write = proc_pid_attr_write,
1964 };
1965
1966 static const struct pid_entry attr_dir_stuff[] = {
1967 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1968 REG("prev", S_IRUGO, pid_attr),
1969 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1970 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1971 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1972 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1973 };
1974
1975 static int proc_attr_dir_readdir(struct file * filp,
1976 void * dirent, filldir_t filldir)
1977 {
1978 return proc_pident_readdir(filp,dirent,filldir,
1979 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1980 }
1981
1982 static const struct file_operations proc_attr_dir_operations = {
1983 .read = generic_read_dir,
1984 .readdir = proc_attr_dir_readdir,
1985 };
1986
1987 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
1988 struct dentry *dentry, struct nameidata *nd)
1989 {
1990 return proc_pident_lookup(dir, dentry,
1991 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
1992 }
1993
1994 static const struct inode_operations proc_attr_dir_inode_operations = {
1995 .lookup = proc_attr_dir_lookup,
1996 .getattr = pid_getattr,
1997 .setattr = proc_setattr,
1998 };
1999
2000 #endif
2001
2002 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2003 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2004 size_t count, loff_t *ppos)
2005 {
2006 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2007 struct mm_struct *mm;
2008 char buffer[PROC_NUMBUF];
2009 size_t len;
2010 int ret;
2011
2012 if (!task)
2013 return -ESRCH;
2014
2015 ret = 0;
2016 mm = get_task_mm(task);
2017 if (mm) {
2018 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2019 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2020 MMF_DUMP_FILTER_SHIFT));
2021 mmput(mm);
2022 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2023 }
2024
2025 put_task_struct(task);
2026
2027 return ret;
2028 }
2029
2030 static ssize_t proc_coredump_filter_write(struct file *file,
2031 const char __user *buf,
2032 size_t count,
2033 loff_t *ppos)
2034 {
2035 struct task_struct *task;
2036 struct mm_struct *mm;
2037 char buffer[PROC_NUMBUF], *end;
2038 unsigned int val;
2039 int ret;
2040 int i;
2041 unsigned long mask;
2042
2043 ret = -EFAULT;
2044 memset(buffer, 0, sizeof(buffer));
2045 if (count > sizeof(buffer) - 1)
2046 count = sizeof(buffer) - 1;
2047 if (copy_from_user(buffer, buf, count))
2048 goto out_no_task;
2049
2050 ret = -EINVAL;
2051 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2052 if (*end == '\n')
2053 end++;
2054 if (end - buffer == 0)
2055 goto out_no_task;
2056
2057 ret = -ESRCH;
2058 task = get_proc_task(file->f_dentry->d_inode);
2059 if (!task)
2060 goto out_no_task;
2061
2062 ret = end - buffer;
2063 mm = get_task_mm(task);
2064 if (!mm)
2065 goto out_no_mm;
2066
2067 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2068 if (val & mask)
2069 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2070 else
2071 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2072 }
2073
2074 mmput(mm);
2075 out_no_mm:
2076 put_task_struct(task);
2077 out_no_task:
2078 return ret;
2079 }
2080
2081 static const struct file_operations proc_coredump_filter_operations = {
2082 .read = proc_coredump_filter_read,
2083 .write = proc_coredump_filter_write,
2084 };
2085 #endif
2086
2087 /*
2088 * /proc/self:
2089 */
2090 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2091 int buflen)
2092 {
2093 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2094 pid_t tgid = task_tgid_nr_ns(current, ns);
2095 char tmp[PROC_NUMBUF];
2096 if (!tgid)
2097 return -ENOENT;
2098 sprintf(tmp, "%d", tgid);
2099 return vfs_readlink(dentry,buffer,buflen,tmp);
2100 }
2101
2102 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2103 {
2104 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2105 pid_t tgid = task_tgid_nr_ns(current, ns);
2106 char tmp[PROC_NUMBUF];
2107 if (!tgid)
2108 return ERR_PTR(-ENOENT);
2109 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2110 return ERR_PTR(vfs_follow_link(nd,tmp));
2111 }
2112
2113 static const struct inode_operations proc_self_inode_operations = {
2114 .readlink = proc_self_readlink,
2115 .follow_link = proc_self_follow_link,
2116 };
2117
2118 /*
2119 * proc base
2120 *
2121 * These are the directory entries in the root directory of /proc
2122 * that properly belong to the /proc filesystem, as they describe
2123 * describe something that is process related.
2124 */
2125 static const struct pid_entry proc_base_stuff[] = {
2126 NOD("self", S_IFLNK|S_IRWXUGO,
2127 &proc_self_inode_operations, NULL, {}),
2128 };
2129
2130 /*
2131 * Exceptional case: normally we are not allowed to unhash a busy
2132 * directory. In this case, however, we can do it - no aliasing problems
2133 * due to the way we treat inodes.
2134 */
2135 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2136 {
2137 struct inode *inode = dentry->d_inode;
2138 struct task_struct *task = get_proc_task(inode);
2139 if (task) {
2140 put_task_struct(task);
2141 return 1;
2142 }
2143 d_drop(dentry);
2144 return 0;
2145 }
2146
2147 static struct dentry_operations proc_base_dentry_operations =
2148 {
2149 .d_revalidate = proc_base_revalidate,
2150 .d_delete = pid_delete_dentry,
2151 };
2152
2153 static struct dentry *proc_base_instantiate(struct inode *dir,
2154 struct dentry *dentry, struct task_struct *task, const void *ptr)
2155 {
2156 const struct pid_entry *p = ptr;
2157 struct inode *inode;
2158 struct proc_inode *ei;
2159 struct dentry *error = ERR_PTR(-EINVAL);
2160
2161 /* Allocate the inode */
2162 error = ERR_PTR(-ENOMEM);
2163 inode = new_inode(dir->i_sb);
2164 if (!inode)
2165 goto out;
2166
2167 /* Initialize the inode */
2168 ei = PROC_I(inode);
2169 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2170
2171 /*
2172 * grab the reference to the task.
2173 */
2174 ei->pid = get_task_pid(task, PIDTYPE_PID);
2175 if (!ei->pid)
2176 goto out_iput;
2177
2178 inode->i_uid = 0;
2179 inode->i_gid = 0;
2180 inode->i_mode = p->mode;
2181 if (S_ISDIR(inode->i_mode))
2182 inode->i_nlink = 2;
2183 if (S_ISLNK(inode->i_mode))
2184 inode->i_size = 64;
2185 if (p->iop)
2186 inode->i_op = p->iop;
2187 if (p->fop)
2188 inode->i_fop = p->fop;
2189 ei->op = p->op;
2190 dentry->d_op = &proc_base_dentry_operations;
2191 d_add(dentry, inode);
2192 error = NULL;
2193 out:
2194 return error;
2195 out_iput:
2196 iput(inode);
2197 goto out;
2198 }
2199
2200 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2201 {
2202 struct dentry *error;
2203 struct task_struct *task = get_proc_task(dir);
2204 const struct pid_entry *p, *last;
2205
2206 error = ERR_PTR(-ENOENT);
2207
2208 if (!task)
2209 goto out_no_task;
2210
2211 /* Lookup the directory entry */
2212 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2213 for (p = proc_base_stuff; p <= last; p++) {
2214 if (p->len != dentry->d_name.len)
2215 continue;
2216 if (!memcmp(dentry->d_name.name, p->name, p->len))
2217 break;
2218 }
2219 if (p > last)
2220 goto out;
2221
2222 error = proc_base_instantiate(dir, dentry, task, p);
2223
2224 out:
2225 put_task_struct(task);
2226 out_no_task:
2227 return error;
2228 }
2229
2230 static int proc_base_fill_cache(struct file *filp, void *dirent,
2231 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2232 {
2233 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2234 proc_base_instantiate, task, p);
2235 }
2236
2237 #ifdef CONFIG_TASK_IO_ACCOUNTING
2238 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2239 {
2240 return sprintf(buffer,
2241 #ifdef CONFIG_TASK_XACCT
2242 "rchar: %llu\n"
2243 "wchar: %llu\n"
2244 "syscr: %llu\n"
2245 "syscw: %llu\n"
2246 #endif
2247 "read_bytes: %llu\n"
2248 "write_bytes: %llu\n"
2249 "cancelled_write_bytes: %llu\n",
2250 #ifdef CONFIG_TASK_XACCT
2251 (unsigned long long)task->rchar,
2252 (unsigned long long)task->wchar,
2253 (unsigned long long)task->syscr,
2254 (unsigned long long)task->syscw,
2255 #endif
2256 (unsigned long long)task->ioac.read_bytes,
2257 (unsigned long long)task->ioac.write_bytes,
2258 (unsigned long long)task->ioac.cancelled_write_bytes);
2259 }
2260 #endif
2261
2262 /*
2263 * Thread groups
2264 */
2265 static const struct file_operations proc_task_operations;
2266 static const struct inode_operations proc_task_inode_operations;
2267
2268 static const struct pid_entry tgid_base_stuff[] = {
2269 DIR("task", S_IRUGO|S_IXUGO, task),
2270 DIR("fd", S_IRUSR|S_IXUSR, fd),
2271 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2272 #ifdef CONFIG_NET
2273 DIR("net", S_IRUGO|S_IXUSR, net),
2274 #endif
2275 REG("environ", S_IRUSR, environ),
2276 INF("auxv", S_IRUSR, pid_auxv),
2277 ONE("status", S_IRUGO, pid_status),
2278 INF("limits", S_IRUSR, pid_limits),
2279 #ifdef CONFIG_SCHED_DEBUG
2280 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2281 #endif
2282 INF("cmdline", S_IRUGO, pid_cmdline),
2283 ONE("stat", S_IRUGO, tgid_stat),
2284 ONE("statm", S_IRUGO, pid_statm),
2285 REG("maps", S_IRUGO, maps),
2286 #ifdef CONFIG_NUMA
2287 REG("numa_maps", S_IRUGO, numa_maps),
2288 #endif
2289 REG("mem", S_IRUSR|S_IWUSR, mem),
2290 LNK("cwd", cwd),
2291 LNK("root", root),
2292 LNK("exe", exe),
2293 REG("mounts", S_IRUGO, mounts),
2294 REG("mountstats", S_IRUSR, mountstats),
2295 #ifdef CONFIG_PROC_PAGE_MONITOR
2296 REG("clear_refs", S_IWUSR, clear_refs),
2297 REG("smaps", S_IRUGO, smaps),
2298 REG("pagemap", S_IRUSR, pagemap),
2299 #endif
2300 #ifdef CONFIG_SECURITY
2301 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2302 #endif
2303 #ifdef CONFIG_KALLSYMS
2304 INF("wchan", S_IRUGO, pid_wchan),
2305 #endif
2306 #ifdef CONFIG_SCHEDSTATS
2307 INF("schedstat", S_IRUGO, pid_schedstat),
2308 #endif
2309 #ifdef CONFIG_LATENCYTOP
2310 REG("latency", S_IRUGO, lstats),
2311 #endif
2312 #ifdef CONFIG_PROC_PID_CPUSET
2313 REG("cpuset", S_IRUGO, cpuset),
2314 #endif
2315 #ifdef CONFIG_CGROUPS
2316 REG("cgroup", S_IRUGO, cgroup),
2317 #endif
2318 INF("oom_score", S_IRUGO, oom_score),
2319 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2320 #ifdef CONFIG_AUDITSYSCALL
2321 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2322 #endif
2323 #ifdef CONFIG_FAULT_INJECTION
2324 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2325 #endif
2326 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2327 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2328 #endif
2329 #ifdef CONFIG_TASK_IO_ACCOUNTING
2330 INF("io", S_IRUGO, pid_io_accounting),
2331 #endif
2332 };
2333
2334 static int proc_tgid_base_readdir(struct file * filp,
2335 void * dirent, filldir_t filldir)
2336 {
2337 return proc_pident_readdir(filp,dirent,filldir,
2338 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2339 }
2340
2341 static const struct file_operations proc_tgid_base_operations = {
2342 .read = generic_read_dir,
2343 .readdir = proc_tgid_base_readdir,
2344 };
2345
2346 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2347 return proc_pident_lookup(dir, dentry,
2348 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2349 }
2350
2351 static const struct inode_operations proc_tgid_base_inode_operations = {
2352 .lookup = proc_tgid_base_lookup,
2353 .getattr = pid_getattr,
2354 .setattr = proc_setattr,
2355 };
2356
2357 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2358 {
2359 struct dentry *dentry, *leader, *dir;
2360 char buf[PROC_NUMBUF];
2361 struct qstr name;
2362
2363 name.name = buf;
2364 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2365 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2366 if (dentry) {
2367 if (!(current->flags & PF_EXITING))
2368 shrink_dcache_parent(dentry);
2369 d_drop(dentry);
2370 dput(dentry);
2371 }
2372
2373 if (tgid == 0)
2374 goto out;
2375
2376 name.name = buf;
2377 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2378 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2379 if (!leader)
2380 goto out;
2381
2382 name.name = "task";
2383 name.len = strlen(name.name);
2384 dir = d_hash_and_lookup(leader, &name);
2385 if (!dir)
2386 goto out_put_leader;
2387
2388 name.name = buf;
2389 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2390 dentry = d_hash_and_lookup(dir, &name);
2391 if (dentry) {
2392 shrink_dcache_parent(dentry);
2393 d_drop(dentry);
2394 dput(dentry);
2395 }
2396
2397 dput(dir);
2398 out_put_leader:
2399 dput(leader);
2400 out:
2401 return;
2402 }
2403
2404 /**
2405 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2406 * @task: task that should be flushed.
2407 *
2408 * When flushing dentries from proc, one needs to flush them from global
2409 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2410 * in. This call is supposed to do all of this job.
2411 *
2412 * Looks in the dcache for
2413 * /proc/@pid
2414 * /proc/@tgid/task/@pid
2415 * if either directory is present flushes it and all of it'ts children
2416 * from the dcache.
2417 *
2418 * It is safe and reasonable to cache /proc entries for a task until
2419 * that task exits. After that they just clog up the dcache with
2420 * useless entries, possibly causing useful dcache entries to be
2421 * flushed instead. This routine is proved to flush those useless
2422 * dcache entries at process exit time.
2423 *
2424 * NOTE: This routine is just an optimization so it does not guarantee
2425 * that no dcache entries will exist at process exit time it
2426 * just makes it very unlikely that any will persist.
2427 */
2428
2429 void proc_flush_task(struct task_struct *task)
2430 {
2431 int i;
2432 struct pid *pid, *tgid = NULL;
2433 struct upid *upid;
2434
2435 pid = task_pid(task);
2436 if (thread_group_leader(task))
2437 tgid = task_tgid(task);
2438
2439 for (i = 0; i <= pid->level; i++) {
2440 upid = &pid->numbers[i];
2441 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2442 tgid ? tgid->numbers[i].nr : 0);
2443 }
2444
2445 upid = &pid->numbers[pid->level];
2446 if (upid->nr == 1)
2447 pid_ns_release_proc(upid->ns);
2448 }
2449
2450 static struct dentry *proc_pid_instantiate(struct inode *dir,
2451 struct dentry * dentry,
2452 struct task_struct *task, const void *ptr)
2453 {
2454 struct dentry *error = ERR_PTR(-ENOENT);
2455 struct inode *inode;
2456
2457 inode = proc_pid_make_inode(dir->i_sb, task);
2458 if (!inode)
2459 goto out;
2460
2461 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2462 inode->i_op = &proc_tgid_base_inode_operations;
2463 inode->i_fop = &proc_tgid_base_operations;
2464 inode->i_flags|=S_IMMUTABLE;
2465 inode->i_nlink = 5;
2466 #ifdef CONFIG_SECURITY
2467 inode->i_nlink += 1;
2468 #endif
2469
2470 dentry->d_op = &pid_dentry_operations;
2471
2472 d_add(dentry, inode);
2473 /* Close the race of the process dying before we return the dentry */
2474 if (pid_revalidate(dentry, NULL))
2475 error = NULL;
2476 out:
2477 return error;
2478 }
2479
2480 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2481 {
2482 struct dentry *result = ERR_PTR(-ENOENT);
2483 struct task_struct *task;
2484 unsigned tgid;
2485 struct pid_namespace *ns;
2486
2487 result = proc_base_lookup(dir, dentry);
2488 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2489 goto out;
2490
2491 tgid = name_to_int(dentry);
2492 if (tgid == ~0U)
2493 goto out;
2494
2495 ns = dentry->d_sb->s_fs_info;
2496 rcu_read_lock();
2497 task = find_task_by_pid_ns(tgid, ns);
2498 if (task)
2499 get_task_struct(task);
2500 rcu_read_unlock();
2501 if (!task)
2502 goto out;
2503
2504 result = proc_pid_instantiate(dir, dentry, task, NULL);
2505 put_task_struct(task);
2506 out:
2507 return result;
2508 }
2509
2510 /*
2511 * Find the first task with tgid >= tgid
2512 *
2513 */
2514 struct tgid_iter {
2515 unsigned int tgid;
2516 struct task_struct *task;
2517 };
2518 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2519 {
2520 struct pid *pid;
2521
2522 if (iter.task)
2523 put_task_struct(iter.task);
2524 rcu_read_lock();
2525 retry:
2526 iter.task = NULL;
2527 pid = find_ge_pid(iter.tgid, ns);
2528 if (pid) {
2529 iter.tgid = pid_nr_ns(pid, ns);
2530 iter.task = pid_task(pid, PIDTYPE_PID);
2531 /* What we to know is if the pid we have find is the
2532 * pid of a thread_group_leader. Testing for task
2533 * being a thread_group_leader is the obvious thing
2534 * todo but there is a window when it fails, due to
2535 * the pid transfer logic in de_thread.
2536 *
2537 * So we perform the straight forward test of seeing
2538 * if the pid we have found is the pid of a thread
2539 * group leader, and don't worry if the task we have
2540 * found doesn't happen to be a thread group leader.
2541 * As we don't care in the case of readdir.
2542 */
2543 if (!iter.task || !has_group_leader_pid(iter.task)) {
2544 iter.tgid += 1;
2545 goto retry;
2546 }
2547 get_task_struct(iter.task);
2548 }
2549 rcu_read_unlock();
2550 return iter;
2551 }
2552
2553 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2554
2555 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2556 struct tgid_iter iter)
2557 {
2558 char name[PROC_NUMBUF];
2559 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2560 return proc_fill_cache(filp, dirent, filldir, name, len,
2561 proc_pid_instantiate, iter.task, NULL);
2562 }
2563
2564 /* for the /proc/ directory itself, after non-process stuff has been done */
2565 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2566 {
2567 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2568 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2569 struct tgid_iter iter;
2570 struct pid_namespace *ns;
2571
2572 if (!reaper)
2573 goto out_no_task;
2574
2575 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2576 const struct pid_entry *p = &proc_base_stuff[nr];
2577 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2578 goto out;
2579 }
2580
2581 ns = filp->f_dentry->d_sb->s_fs_info;
2582 iter.task = NULL;
2583 iter.tgid = filp->f_pos - TGID_OFFSET;
2584 for (iter = next_tgid(ns, iter);
2585 iter.task;
2586 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2587 filp->f_pos = iter.tgid + TGID_OFFSET;
2588 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2589 put_task_struct(iter.task);
2590 goto out;
2591 }
2592 }
2593 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2594 out:
2595 put_task_struct(reaper);
2596 out_no_task:
2597 return 0;
2598 }
2599
2600 /*
2601 * Tasks
2602 */
2603 static const struct pid_entry tid_base_stuff[] = {
2604 DIR("fd", S_IRUSR|S_IXUSR, fd),
2605 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2606 REG("environ", S_IRUSR, environ),
2607 INF("auxv", S_IRUSR, pid_auxv),
2608 ONE("status", S_IRUGO, pid_status),
2609 INF("limits", S_IRUSR, pid_limits),
2610 #ifdef CONFIG_SCHED_DEBUG
2611 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2612 #endif
2613 INF("cmdline", S_IRUGO, pid_cmdline),
2614 ONE("stat", S_IRUGO, tid_stat),
2615 ONE("statm", S_IRUGO, pid_statm),
2616 REG("maps", S_IRUGO, maps),
2617 #ifdef CONFIG_NUMA
2618 REG("numa_maps", S_IRUGO, numa_maps),
2619 #endif
2620 REG("mem", S_IRUSR|S_IWUSR, mem),
2621 LNK("cwd", cwd),
2622 LNK("root", root),
2623 LNK("exe", exe),
2624 REG("mounts", S_IRUGO, mounts),
2625 #ifdef CONFIG_PROC_PAGE_MONITOR
2626 REG("clear_refs", S_IWUSR, clear_refs),
2627 REG("smaps", S_IRUGO, smaps),
2628 REG("pagemap", S_IRUSR, pagemap),
2629 #endif
2630 #ifdef CONFIG_SECURITY
2631 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2632 #endif
2633 #ifdef CONFIG_KALLSYMS
2634 INF("wchan", S_IRUGO, pid_wchan),
2635 #endif
2636 #ifdef CONFIG_SCHEDSTATS
2637 INF("schedstat", S_IRUGO, pid_schedstat),
2638 #endif
2639 #ifdef CONFIG_LATENCYTOP
2640 REG("latency", S_IRUGO, lstats),
2641 #endif
2642 #ifdef CONFIG_PROC_PID_CPUSET
2643 REG("cpuset", S_IRUGO, cpuset),
2644 #endif
2645 #ifdef CONFIG_CGROUPS
2646 REG("cgroup", S_IRUGO, cgroup),
2647 #endif
2648 INF("oom_score", S_IRUGO, oom_score),
2649 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2650 #ifdef CONFIG_AUDITSYSCALL
2651 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2652 #endif
2653 #ifdef CONFIG_FAULT_INJECTION
2654 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2655 #endif
2656 };
2657
2658 static int proc_tid_base_readdir(struct file * filp,
2659 void * dirent, filldir_t filldir)
2660 {
2661 return proc_pident_readdir(filp,dirent,filldir,
2662 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2663 }
2664
2665 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2666 return proc_pident_lookup(dir, dentry,
2667 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2668 }
2669
2670 static const struct file_operations proc_tid_base_operations = {
2671 .read = generic_read_dir,
2672 .readdir = proc_tid_base_readdir,
2673 };
2674
2675 static const struct inode_operations proc_tid_base_inode_operations = {
2676 .lookup = proc_tid_base_lookup,
2677 .getattr = pid_getattr,
2678 .setattr = proc_setattr,
2679 };
2680
2681 static struct dentry *proc_task_instantiate(struct inode *dir,
2682 struct dentry *dentry, struct task_struct *task, const void *ptr)
2683 {
2684 struct dentry *error = ERR_PTR(-ENOENT);
2685 struct inode *inode;
2686 inode = proc_pid_make_inode(dir->i_sb, task);
2687
2688 if (!inode)
2689 goto out;
2690 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2691 inode->i_op = &proc_tid_base_inode_operations;
2692 inode->i_fop = &proc_tid_base_operations;
2693 inode->i_flags|=S_IMMUTABLE;
2694 inode->i_nlink = 4;
2695 #ifdef CONFIG_SECURITY
2696 inode->i_nlink += 1;
2697 #endif
2698
2699 dentry->d_op = &pid_dentry_operations;
2700
2701 d_add(dentry, inode);
2702 /* Close the race of the process dying before we return the dentry */
2703 if (pid_revalidate(dentry, NULL))
2704 error = NULL;
2705 out:
2706 return error;
2707 }
2708
2709 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2710 {
2711 struct dentry *result = ERR_PTR(-ENOENT);
2712 struct task_struct *task;
2713 struct task_struct *leader = get_proc_task(dir);
2714 unsigned tid;
2715 struct pid_namespace *ns;
2716
2717 if (!leader)
2718 goto out_no_task;
2719
2720 tid = name_to_int(dentry);
2721 if (tid == ~0U)
2722 goto out;
2723
2724 ns = dentry->d_sb->s_fs_info;
2725 rcu_read_lock();
2726 task = find_task_by_pid_ns(tid, ns);
2727 if (task)
2728 get_task_struct(task);
2729 rcu_read_unlock();
2730 if (!task)
2731 goto out;
2732 if (!same_thread_group(leader, task))
2733 goto out_drop_task;
2734
2735 result = proc_task_instantiate(dir, dentry, task, NULL);
2736 out_drop_task:
2737 put_task_struct(task);
2738 out:
2739 put_task_struct(leader);
2740 out_no_task:
2741 return result;
2742 }
2743
2744 /*
2745 * Find the first tid of a thread group to return to user space.
2746 *
2747 * Usually this is just the thread group leader, but if the users
2748 * buffer was too small or there was a seek into the middle of the
2749 * directory we have more work todo.
2750 *
2751 * In the case of a short read we start with find_task_by_pid.
2752 *
2753 * In the case of a seek we start with the leader and walk nr
2754 * threads past it.
2755 */
2756 static struct task_struct *first_tid(struct task_struct *leader,
2757 int tid, int nr, struct pid_namespace *ns)
2758 {
2759 struct task_struct *pos;
2760
2761 rcu_read_lock();
2762 /* Attempt to start with the pid of a thread */
2763 if (tid && (nr > 0)) {
2764 pos = find_task_by_pid_ns(tid, ns);
2765 if (pos && (pos->group_leader == leader))
2766 goto found;
2767 }
2768
2769 /* If nr exceeds the number of threads there is nothing todo */
2770 pos = NULL;
2771 if (nr && nr >= get_nr_threads(leader))
2772 goto out;
2773
2774 /* If we haven't found our starting place yet start
2775 * with the leader and walk nr threads forward.
2776 */
2777 for (pos = leader; nr > 0; --nr) {
2778 pos = next_thread(pos);
2779 if (pos == leader) {
2780 pos = NULL;
2781 goto out;
2782 }
2783 }
2784 found:
2785 get_task_struct(pos);
2786 out:
2787 rcu_read_unlock();
2788 return pos;
2789 }
2790
2791 /*
2792 * Find the next thread in the thread list.
2793 * Return NULL if there is an error or no next thread.
2794 *
2795 * The reference to the input task_struct is released.
2796 */
2797 static struct task_struct *next_tid(struct task_struct *start)
2798 {
2799 struct task_struct *pos = NULL;
2800 rcu_read_lock();
2801 if (pid_alive(start)) {
2802 pos = next_thread(start);
2803 if (thread_group_leader(pos))
2804 pos = NULL;
2805 else
2806 get_task_struct(pos);
2807 }
2808 rcu_read_unlock();
2809 put_task_struct(start);
2810 return pos;
2811 }
2812
2813 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2814 struct task_struct *task, int tid)
2815 {
2816 char name[PROC_NUMBUF];
2817 int len = snprintf(name, sizeof(name), "%d", tid);
2818 return proc_fill_cache(filp, dirent, filldir, name, len,
2819 proc_task_instantiate, task, NULL);
2820 }
2821
2822 /* for the /proc/TGID/task/ directories */
2823 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2824 {
2825 struct dentry *dentry = filp->f_path.dentry;
2826 struct inode *inode = dentry->d_inode;
2827 struct task_struct *leader = NULL;
2828 struct task_struct *task;
2829 int retval = -ENOENT;
2830 ino_t ino;
2831 int tid;
2832 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2833 struct pid_namespace *ns;
2834
2835 task = get_proc_task(inode);
2836 if (!task)
2837 goto out_no_task;
2838 rcu_read_lock();
2839 if (pid_alive(task)) {
2840 leader = task->group_leader;
2841 get_task_struct(leader);
2842 }
2843 rcu_read_unlock();
2844 put_task_struct(task);
2845 if (!leader)
2846 goto out_no_task;
2847 retval = 0;
2848
2849 switch (pos) {
2850 case 0:
2851 ino = inode->i_ino;
2852 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2853 goto out;
2854 pos++;
2855 /* fall through */
2856 case 1:
2857 ino = parent_ino(dentry);
2858 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2859 goto out;
2860 pos++;
2861 /* fall through */
2862 }
2863
2864 /* f_version caches the tgid value that the last readdir call couldn't
2865 * return. lseek aka telldir automagically resets f_version to 0.
2866 */
2867 ns = filp->f_dentry->d_sb->s_fs_info;
2868 tid = (int)filp->f_version;
2869 filp->f_version = 0;
2870 for (task = first_tid(leader, tid, pos - 2, ns);
2871 task;
2872 task = next_tid(task), pos++) {
2873 tid = task_pid_nr_ns(task, ns);
2874 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2875 /* returning this tgid failed, save it as the first
2876 * pid for the next readir call */
2877 filp->f_version = (u64)tid;
2878 put_task_struct(task);
2879 break;
2880 }
2881 }
2882 out:
2883 filp->f_pos = pos;
2884 put_task_struct(leader);
2885 out_no_task:
2886 return retval;
2887 }
2888
2889 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2890 {
2891 struct inode *inode = dentry->d_inode;
2892 struct task_struct *p = get_proc_task(inode);
2893 generic_fillattr(inode, stat);
2894
2895 if (p) {
2896 rcu_read_lock();
2897 stat->nlink += get_nr_threads(p);
2898 rcu_read_unlock();
2899 put_task_struct(p);
2900 }
2901
2902 return 0;
2903 }
2904
2905 static const struct inode_operations proc_task_inode_operations = {
2906 .lookup = proc_task_lookup,
2907 .getattr = proc_task_getattr,
2908 .setattr = proc_setattr,
2909 };
2910
2911 static const struct file_operations proc_task_operations = {
2912 .read = generic_read_dir,
2913 .readdir = proc_task_readdir,
2914 };
WRT350N Kernel Patches