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maps4: move clear_refs code to task_mmu.c
[linux-2.6/zen-sources.git] / fs / proc / base.c
blob1bd646d3fe9a1d1ecca82e64f638a58a66b4da18
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
125 int maps_protect;
126 EXPORT_SYMBOL(maps_protect);
127
128 static struct fs_struct *get_fs_struct(struct task_struct *task)
129 {
130 struct fs_struct *fs;
131 task_lock(task);
132 fs = task->fs;
133 if(fs)
134 atomic_inc(&fs->count);
135 task_unlock(task);
136 return fs;
137 }
138
139 static int get_nr_threads(struct task_struct *tsk)
140 {
141 /* Must be called with the rcu_read_lock held */
142 unsigned long flags;
143 int count = 0;
144
145 if (lock_task_sighand(tsk, &flags)) {
146 count = atomic_read(&tsk->signal->count);
147 unlock_task_sighand(tsk, &flags);
148 }
149 return count;
150 }
151
152 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
153 {
154 struct task_struct *task = get_proc_task(inode);
155 struct fs_struct *fs = NULL;
156 int result = -ENOENT;
157
158 if (task) {
159 fs = get_fs_struct(task);
160 put_task_struct(task);
161 }
162 if (fs) {
163 read_lock(&fs->lock);
164 *mnt = mntget(fs->pwdmnt);
165 *dentry = dget(fs->pwd);
166 read_unlock(&fs->lock);
167 result = 0;
168 put_fs_struct(fs);
169 }
170 return result;
171 }
172
173 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
174 {
175 struct task_struct *task = get_proc_task(inode);
176 struct fs_struct *fs = NULL;
177 int result = -ENOENT;
178
179 if (task) {
180 fs = get_fs_struct(task);
181 put_task_struct(task);
182 }
183 if (fs) {
184 read_lock(&fs->lock);
185 *mnt = mntget(fs->rootmnt);
186 *dentry = dget(fs->root);
187 read_unlock(&fs->lock);
188 result = 0;
189 put_fs_struct(fs);
190 }
191 return result;
192 }
193
194 #define MAY_PTRACE(task) \
195 (task == current || \
196 (task->parent == current && \
197 (task->ptrace & PT_PTRACED) && \
198 (task_is_stopped_or_traced(task)) && \
199 security_ptrace(current,task) == 0))
200
201 struct mm_struct *mm_for_maps(struct task_struct *task)
202 {
203 struct mm_struct *mm = get_task_mm(task);
204 if (!mm)
205 return NULL;
206 down_read(&mm->mmap_sem);
207 task_lock(task);
208 if (task->mm != mm)
209 goto out;
210 if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
211 goto out;
212 task_unlock(task);
213 return mm;
214 out:
215 task_unlock(task);
216 up_read(&mm->mmap_sem);
217 mmput(mm);
218 return NULL;
219 }
220
221 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
222 {
223 int res = 0;
224 unsigned int len;
225 struct mm_struct *mm = get_task_mm(task);
226 if (!mm)
227 goto out;
228 if (!mm->arg_end)
229 goto out_mm; /* Shh! No looking before we're done */
230
231 len = mm->arg_end - mm->arg_start;
232
233 if (len > PAGE_SIZE)
234 len = PAGE_SIZE;
235
236 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
237
238 // If the nul at the end of args has been overwritten, then
239 // assume application is using setproctitle(3).
240 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
241 len = strnlen(buffer, res);
242 if (len < res) {
243 res = len;
244 } else {
245 len = mm->env_end - mm->env_start;
246 if (len > PAGE_SIZE - res)
247 len = PAGE_SIZE - res;
248 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
249 res = strnlen(buffer, res);
250 }
251 }
252 out_mm:
253 mmput(mm);
254 out:
255 return res;
256 }
257
258 static int proc_pid_auxv(struct task_struct *task, char *buffer)
259 {
260 int res = 0;
261 struct mm_struct *mm = get_task_mm(task);
262 if (mm) {
263 unsigned int nwords = 0;
264 do
265 nwords += 2;
266 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
267 res = nwords * sizeof(mm->saved_auxv[0]);
268 if (res > PAGE_SIZE)
269 res = PAGE_SIZE;
270 memcpy(buffer, mm->saved_auxv, res);
271 mmput(mm);
272 }
273 return res;
274 }
275
276
277 #ifdef CONFIG_KALLSYMS
278 /*
279 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
280 * Returns the resolved symbol. If that fails, simply return the address.
281 */
282 static int proc_pid_wchan(struct task_struct *task, char *buffer)
283 {
284 unsigned long wchan;
285 char symname[KSYM_NAME_LEN];
286
287 wchan = get_wchan(task);
288
289 if (lookup_symbol_name(wchan, symname) < 0)
290 return sprintf(buffer, "%lu", wchan);
291 else
292 return sprintf(buffer, "%s", symname);
293 }
294 #endif /* CONFIG_KALLSYMS */
295
296 #ifdef CONFIG_SCHEDSTATS
297 /*
298 * Provides /proc/PID/schedstat
299 */
300 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
301 {
302 return sprintf(buffer, "%llu %llu %lu\n",
303 task->sched_info.cpu_time,
304 task->sched_info.run_delay,
305 task->sched_info.pcount);
306 }
307 #endif
308
309 #ifdef CONFIG_LATENCYTOP
310 static int lstats_show_proc(struct seq_file *m, void *v)
311 {
312 int i;
313 struct task_struct *task = m->private;
314 seq_puts(m, "Latency Top version : v0.1\n");
315
316 for (i = 0; i < 32; i++) {
317 if (task->latency_record[i].backtrace[0]) {
318 int q;
319 seq_printf(m, "%i %li %li ",
320 task->latency_record[i].count,
321 task->latency_record[i].time,
322 task->latency_record[i].max);
323 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
324 char sym[KSYM_NAME_LEN];
325 char *c;
326 if (!task->latency_record[i].backtrace[q])
327 break;
328 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
329 break;
330 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
331 c = strchr(sym, '+');
332 if (c)
333 *c = 0;
334 seq_printf(m, "%s ", sym);
335 }
336 seq_printf(m, "\n");
337 }
338
339 }
340 return 0;
341 }
342
343 static int lstats_open(struct inode *inode, struct file *file)
344 {
345 int ret;
346 struct seq_file *m;
347 struct task_struct *task = get_proc_task(inode);
348
349 ret = single_open(file, lstats_show_proc, NULL);
350 if (!ret) {
351 m = file->private_data;
352 m->private = task;
353 }
354 return ret;
355 }
356
357 static ssize_t lstats_write(struct file *file, const char __user *buf,
358 size_t count, loff_t *offs)
359 {
360 struct seq_file *m;
361 struct task_struct *task;
362
363 m = file->private_data;
364 task = m->private;
365 clear_all_latency_tracing(task);
366
367 return count;
368 }
369
370 static const struct file_operations proc_lstats_operations = {
371 .open = lstats_open,
372 .read = seq_read,
373 .write = lstats_write,
374 .llseek = seq_lseek,
375 .release = single_release,
376 };
377
378 #endif
379
380 /* The badness from the OOM killer */
381 unsigned long badness(struct task_struct *p, unsigned long uptime);
382 static int proc_oom_score(struct task_struct *task, char *buffer)
383 {
384 unsigned long points;
385 struct timespec uptime;
386
387 do_posix_clock_monotonic_gettime(&uptime);
388 read_lock(&tasklist_lock);
389 points = badness(task, uptime.tv_sec);
390 read_unlock(&tasklist_lock);
391 return sprintf(buffer, "%lu\n", points);
392 }
393
394 struct limit_names {
395 char *name;
396 char *unit;
397 };
398
399 static const struct limit_names lnames[RLIM_NLIMITS] = {
400 [RLIMIT_CPU] = {"Max cpu time", "ms"},
401 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
402 [RLIMIT_DATA] = {"Max data size", "bytes"},
403 [RLIMIT_STACK] = {"Max stack size", "bytes"},
404 [RLIMIT_CORE] = {"Max core file size", "bytes"},
405 [RLIMIT_RSS] = {"Max resident set", "bytes"},
406 [RLIMIT_NPROC] = {"Max processes", "processes"},
407 [RLIMIT_NOFILE] = {"Max open files", "files"},
408 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
409 [RLIMIT_AS] = {"Max address space", "bytes"},
410 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
411 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
412 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
413 [RLIMIT_NICE] = {"Max nice priority", NULL},
414 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
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 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 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 mem_open(struct inode* inode, struct file* file)
662 {
663 file->private_data = (void*)((long)current->self_exec_id);
664 return 0;
665 }
666
667 static ssize_t mem_read(struct file * file, char __user * buf,
668 size_t count, loff_t *ppos)
669 {
670 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
671 char *page;
672 unsigned long src = *ppos;
673 int ret = -ESRCH;
674 struct mm_struct *mm;
675
676 if (!task)
677 goto out_no_task;
678
679 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
680 goto out;
681
682 ret = -ENOMEM;
683 page = (char *)__get_free_page(GFP_TEMPORARY);
684 if (!page)
685 goto out;
686
687 ret = 0;
688
689 mm = get_task_mm(task);
690 if (!mm)
691 goto out_free;
692
693 ret = -EIO;
694
695 if (file->private_data != (void*)((long)current->self_exec_id))
696 goto out_put;
697
698 ret = 0;
699
700 while (count > 0) {
701 int this_len, retval;
702
703 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
704 retval = access_process_vm(task, src, page, this_len, 0);
705 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
706 if (!ret)
707 ret = -EIO;
708 break;
709 }
710
711 if (copy_to_user(buf, page, retval)) {
712 ret = -EFAULT;
713 break;
714 }
715
716 ret += retval;
717 src += retval;
718 buf += retval;
719 count -= retval;
720 }
721 *ppos = src;
722
723 out_put:
724 mmput(mm);
725 out_free:
726 free_page((unsigned long) page);
727 out:
728 put_task_struct(task);
729 out_no_task:
730 return ret;
731 }
732
733 #define mem_write NULL
734
735 #ifndef mem_write
736 /* This is a security hazard */
737 static ssize_t mem_write(struct file * file, const char __user *buf,
738 size_t count, loff_t *ppos)
739 {
740 int copied;
741 char *page;
742 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
743 unsigned long dst = *ppos;
744
745 copied = -ESRCH;
746 if (!task)
747 goto out_no_task;
748
749 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
750 goto out;
751
752 copied = -ENOMEM;
753 page = (char *)__get_free_page(GFP_TEMPORARY);
754 if (!page)
755 goto out;
756
757 copied = 0;
758 while (count > 0) {
759 int this_len, retval;
760
761 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
762 if (copy_from_user(page, buf, this_len)) {
763 copied = -EFAULT;
764 break;
765 }
766 retval = access_process_vm(task, dst, page, this_len, 1);
767 if (!retval) {
768 if (!copied)
769 copied = -EIO;
770 break;
771 }
772 copied += retval;
773 buf += retval;
774 dst += retval;
775 count -= retval;
776 }
777 *ppos = dst;
778 free_page((unsigned long) page);
779 out:
780 put_task_struct(task);
781 out_no_task:
782 return copied;
783 }
784 #endif
785
786 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
787 {
788 switch (orig) {
789 case 0:
790 file->f_pos = offset;
791 break;
792 case 1:
793 file->f_pos += offset;
794 break;
795 default:
796 return -EINVAL;
797 }
798 force_successful_syscall_return();
799 return file->f_pos;
800 }
801
802 static const struct file_operations proc_mem_operations = {
803 .llseek = mem_lseek,
804 .read = mem_read,
805 .write = mem_write,
806 .open = mem_open,
807 };
808
809 static ssize_t environ_read(struct file *file, char __user *buf,
810 size_t count, loff_t *ppos)
811 {
812 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
813 char *page;
814 unsigned long src = *ppos;
815 int ret = -ESRCH;
816 struct mm_struct *mm;
817
818 if (!task)
819 goto out_no_task;
820
821 if (!ptrace_may_attach(task))
822 goto out;
823
824 ret = -ENOMEM;
825 page = (char *)__get_free_page(GFP_TEMPORARY);
826 if (!page)
827 goto out;
828
829 ret = 0;
830
831 mm = get_task_mm(task);
832 if (!mm)
833 goto out_free;
834
835 while (count > 0) {
836 int this_len, retval, max_len;
837
838 this_len = mm->env_end - (mm->env_start + src);
839
840 if (this_len <= 0)
841 break;
842
843 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
844 this_len = (this_len > max_len) ? max_len : this_len;
845
846 retval = access_process_vm(task, (mm->env_start + src),
847 page, this_len, 0);
848
849 if (retval <= 0) {
850 ret = retval;
851 break;
852 }
853
854 if (copy_to_user(buf, page, retval)) {
855 ret = -EFAULT;
856 break;
857 }
858
859 ret += retval;
860 src += retval;
861 buf += retval;
862 count -= retval;
863 }
864 *ppos = src;
865
866 mmput(mm);
867 out_free:
868 free_page((unsigned long) page);
869 out:
870 put_task_struct(task);
871 out_no_task:
872 return ret;
873 }
874
875 static const struct file_operations proc_environ_operations = {
876 .read = environ_read,
877 };
878
879 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
880 size_t count, loff_t *ppos)
881 {
882 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
883 char buffer[PROC_NUMBUF];
884 size_t len;
885 int oom_adjust;
886
887 if (!task)
888 return -ESRCH;
889 oom_adjust = task->oomkilladj;
890 put_task_struct(task);
891
892 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
893
894 return simple_read_from_buffer(buf, count, ppos, buffer, len);
895 }
896
897 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
898 size_t count, loff_t *ppos)
899 {
900 struct task_struct *task;
901 char buffer[PROC_NUMBUF], *end;
902 int oom_adjust;
903
904 memset(buffer, 0, sizeof(buffer));
905 if (count > sizeof(buffer) - 1)
906 count = sizeof(buffer) - 1;
907 if (copy_from_user(buffer, buf, count))
908 return -EFAULT;
909 oom_adjust = simple_strtol(buffer, &end, 0);
910 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
911 oom_adjust != OOM_DISABLE)
912 return -EINVAL;
913 if (*end == '\n')
914 end++;
915 task = get_proc_task(file->f_path.dentry->d_inode);
916 if (!task)
917 return -ESRCH;
918 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
919 put_task_struct(task);
920 return -EACCES;
921 }
922 task->oomkilladj = oom_adjust;
923 put_task_struct(task);
924 if (end - buffer == 0)
925 return -EIO;
926 return end - buffer;
927 }
928
929 static const struct file_operations proc_oom_adjust_operations = {
930 .read = oom_adjust_read,
931 .write = oom_adjust_write,
932 };
933
934 #ifdef CONFIG_AUDITSYSCALL
935 #define TMPBUFLEN 21
936 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
937 size_t count, loff_t *ppos)
938 {
939 struct inode * inode = file->f_path.dentry->d_inode;
940 struct task_struct *task = get_proc_task(inode);
941 ssize_t length;
942 char tmpbuf[TMPBUFLEN];
943
944 if (!task)
945 return -ESRCH;
946 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
947 audit_get_loginuid(task));
948 put_task_struct(task);
949 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
950 }
951
952 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
953 size_t count, loff_t *ppos)
954 {
955 struct inode * inode = file->f_path.dentry->d_inode;
956 char *page, *tmp;
957 ssize_t length;
958 uid_t loginuid;
959
960 if (!capable(CAP_AUDIT_CONTROL))
961 return -EPERM;
962
963 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
964 return -EPERM;
965
966 if (count >= PAGE_SIZE)
967 count = PAGE_SIZE - 1;
968
969 if (*ppos != 0) {
970 /* No partial writes. */
971 return -EINVAL;
972 }
973 page = (char*)__get_free_page(GFP_TEMPORARY);
974 if (!page)
975 return -ENOMEM;
976 length = -EFAULT;
977 if (copy_from_user(page, buf, count))
978 goto out_free_page;
979
980 page[count] = '\0';
981 loginuid = simple_strtoul(page, &tmp, 10);
982 if (tmp == page) {
983 length = -EINVAL;
984 goto out_free_page;
985
986 }
987 length = audit_set_loginuid(current, loginuid);
988 if (likely(length == 0))
989 length = count;
990
991 out_free_page:
992 free_page((unsigned long) page);
993 return length;
994 }
995
996 static const struct file_operations proc_loginuid_operations = {
997 .read = proc_loginuid_read,
998 .write = proc_loginuid_write,
999 };
1000 #endif
1001
1002 #ifdef CONFIG_FAULT_INJECTION
1003 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1004 size_t count, loff_t *ppos)
1005 {
1006 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1007 char buffer[PROC_NUMBUF];
1008 size_t len;
1009 int make_it_fail;
1010
1011 if (!task)
1012 return -ESRCH;
1013 make_it_fail = task->make_it_fail;
1014 put_task_struct(task);
1015
1016 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1017
1018 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1019 }
1020
1021 static ssize_t proc_fault_inject_write(struct file * file,
1022 const char __user * buf, size_t count, loff_t *ppos)
1023 {
1024 struct task_struct *task;
1025 char buffer[PROC_NUMBUF], *end;
1026 int make_it_fail;
1027
1028 if (!capable(CAP_SYS_RESOURCE))
1029 return -EPERM;
1030 memset(buffer, 0, sizeof(buffer));
1031 if (count > sizeof(buffer) - 1)
1032 count = sizeof(buffer) - 1;
1033 if (copy_from_user(buffer, buf, count))
1034 return -EFAULT;
1035 make_it_fail = simple_strtol(buffer, &end, 0);
1036 if (*end == '\n')
1037 end++;
1038 task = get_proc_task(file->f_dentry->d_inode);
1039 if (!task)
1040 return -ESRCH;
1041 task->make_it_fail = make_it_fail;
1042 put_task_struct(task);
1043 if (end - buffer == 0)
1044 return -EIO;
1045 return end - buffer;
1046 }
1047
1048 static const struct file_operations proc_fault_inject_operations = {
1049 .read = proc_fault_inject_read,
1050 .write = proc_fault_inject_write,
1051 };
1052 #endif
1053
1054
1055 #ifdef CONFIG_SCHED_DEBUG
1056 /*
1057 * Print out various scheduling related per-task fields:
1058 */
1059 static int sched_show(struct seq_file *m, void *v)
1060 {
1061 struct inode *inode = m->private;
1062 struct task_struct *p;
1063
1064 WARN_ON(!inode);
1065
1066 p = get_proc_task(inode);
1067 if (!p)
1068 return -ESRCH;
1069 proc_sched_show_task(p, m);
1070
1071 put_task_struct(p);
1072
1073 return 0;
1074 }
1075
1076 static ssize_t
1077 sched_write(struct file *file, const char __user *buf,
1078 size_t count, loff_t *offset)
1079 {
1080 struct inode *inode = file->f_path.dentry->d_inode;
1081 struct task_struct *p;
1082
1083 WARN_ON(!inode);
1084
1085 p = get_proc_task(inode);
1086 if (!p)
1087 return -ESRCH;
1088 proc_sched_set_task(p);
1089
1090 put_task_struct(p);
1091
1092 return count;
1093 }
1094
1095 static int sched_open(struct inode *inode, struct file *filp)
1096 {
1097 int ret;
1098
1099 ret = single_open(filp, sched_show, NULL);
1100 if (!ret) {
1101 struct seq_file *m = filp->private_data;
1102
1103 m->private = inode;
1104 }
1105 return ret;
1106 }
1107
1108 static const struct file_operations proc_pid_sched_operations = {
1109 .open = sched_open,
1110 .read = seq_read,
1111 .write = sched_write,
1112 .llseek = seq_lseek,
1113 .release = single_release,
1114 };
1115
1116 #endif
1117
1118 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1119 {
1120 struct inode *inode = dentry->d_inode;
1121 int error = -EACCES;
1122
1123 /* We don't need a base pointer in the /proc filesystem */
1124 path_release(nd);
1125
1126 /* Are we allowed to snoop on the tasks file descriptors? */
1127 if (!proc_fd_access_allowed(inode))
1128 goto out;
1129
1130 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1131 nd->last_type = LAST_BIND;
1132 out:
1133 return ERR_PTR(error);
1134 }
1135
1136 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1137 char __user *buffer, int buflen)
1138 {
1139 struct inode * inode;
1140 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1141 char *path;
1142 int len;
1143
1144 if (!tmp)
1145 return -ENOMEM;
1146
1147 inode = dentry->d_inode;
1148 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1149 len = PTR_ERR(path);
1150 if (IS_ERR(path))
1151 goto out;
1152 len = tmp + PAGE_SIZE - 1 - path;
1153
1154 if (len > buflen)
1155 len = buflen;
1156 if (copy_to_user(buffer, path, len))
1157 len = -EFAULT;
1158 out:
1159 free_page((unsigned long)tmp);
1160 return len;
1161 }
1162
1163 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1164 {
1165 int error = -EACCES;
1166 struct inode *inode = dentry->d_inode;
1167 struct dentry *de;
1168 struct vfsmount *mnt = NULL;
1169
1170 /* Are we allowed to snoop on the tasks file descriptors? */
1171 if (!proc_fd_access_allowed(inode))
1172 goto out;
1173
1174 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1175 if (error)
1176 goto out;
1177
1178 error = do_proc_readlink(de, mnt, buffer, buflen);
1179 dput(de);
1180 mntput(mnt);
1181 out:
1182 return error;
1183 }
1184
1185 static const struct inode_operations proc_pid_link_inode_operations = {
1186 .readlink = proc_pid_readlink,
1187 .follow_link = proc_pid_follow_link,
1188 .setattr = proc_setattr,
1189 };
1190
1191
1192 /* building an inode */
1193
1194 static int task_dumpable(struct task_struct *task)
1195 {
1196 int dumpable = 0;
1197 struct mm_struct *mm;
1198
1199 task_lock(task);
1200 mm = task->mm;
1201 if (mm)
1202 dumpable = get_dumpable(mm);
1203 task_unlock(task);
1204 if(dumpable == 1)
1205 return 1;
1206 return 0;
1207 }
1208
1209
1210 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1211 {
1212 struct inode * inode;
1213 struct proc_inode *ei;
1214
1215 /* We need a new inode */
1216
1217 inode = new_inode(sb);
1218 if (!inode)
1219 goto out;
1220
1221 /* Common stuff */
1222 ei = PROC_I(inode);
1223 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1224 inode->i_op = &proc_def_inode_operations;
1225
1226 /*
1227 * grab the reference to task.
1228 */
1229 ei->pid = get_task_pid(task, PIDTYPE_PID);
1230 if (!ei->pid)
1231 goto out_unlock;
1232
1233 inode->i_uid = 0;
1234 inode->i_gid = 0;
1235 if (task_dumpable(task)) {
1236 inode->i_uid = task->euid;
1237 inode->i_gid = task->egid;
1238 }
1239 security_task_to_inode(task, inode);
1240
1241 out:
1242 return inode;
1243
1244 out_unlock:
1245 iput(inode);
1246 return NULL;
1247 }
1248
1249 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1250 {
1251 struct inode *inode = dentry->d_inode;
1252 struct task_struct *task;
1253 generic_fillattr(inode, stat);
1254
1255 rcu_read_lock();
1256 stat->uid = 0;
1257 stat->gid = 0;
1258 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1259 if (task) {
1260 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1261 task_dumpable(task)) {
1262 stat->uid = task->euid;
1263 stat->gid = task->egid;
1264 }
1265 }
1266 rcu_read_unlock();
1267 return 0;
1268 }
1269
1270 /* dentry stuff */
1271
1272 /*
1273 * Exceptional case: normally we are not allowed to unhash a busy
1274 * directory. In this case, however, we can do it - no aliasing problems
1275 * due to the way we treat inodes.
1276 *
1277 * Rewrite the inode's ownerships here because the owning task may have
1278 * performed a setuid(), etc.
1279 *
1280 * Before the /proc/pid/status file was created the only way to read
1281 * the effective uid of a /process was to stat /proc/pid. Reading
1282 * /proc/pid/status is slow enough that procps and other packages
1283 * kept stating /proc/pid. To keep the rules in /proc simple I have
1284 * made this apply to all per process world readable and executable
1285 * directories.
1286 */
1287 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1288 {
1289 struct inode *inode = dentry->d_inode;
1290 struct task_struct *task = get_proc_task(inode);
1291 if (task) {
1292 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1293 task_dumpable(task)) {
1294 inode->i_uid = task->euid;
1295 inode->i_gid = task->egid;
1296 } else {
1297 inode->i_uid = 0;
1298 inode->i_gid = 0;
1299 }
1300 inode->i_mode &= ~(S_ISUID | S_ISGID);
1301 security_task_to_inode(task, inode);
1302 put_task_struct(task);
1303 return 1;
1304 }
1305 d_drop(dentry);
1306 return 0;
1307 }
1308
1309 static int pid_delete_dentry(struct dentry * dentry)
1310 {
1311 /* Is the task we represent dead?
1312 * If so, then don't put the dentry on the lru list,
1313 * kill it immediately.
1314 */
1315 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1316 }
1317
1318 static struct dentry_operations pid_dentry_operations =
1319 {
1320 .d_revalidate = pid_revalidate,
1321 .d_delete = pid_delete_dentry,
1322 };
1323
1324 /* Lookups */
1325
1326 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1327 struct task_struct *, const void *);
1328
1329 /*
1330 * Fill a directory entry.
1331 *
1332 * If possible create the dcache entry and derive our inode number and
1333 * file type from dcache entry.
1334 *
1335 * Since all of the proc inode numbers are dynamically generated, the inode
1336 * numbers do not exist until the inode is cache. This means creating the
1337 * the dcache entry in readdir is necessary to keep the inode numbers
1338 * reported by readdir in sync with the inode numbers reported
1339 * by stat.
1340 */
1341 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1342 char *name, int len,
1343 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1344 {
1345 struct dentry *child, *dir = filp->f_path.dentry;
1346 struct inode *inode;
1347 struct qstr qname;
1348 ino_t ino = 0;
1349 unsigned type = DT_UNKNOWN;
1350
1351 qname.name = name;
1352 qname.len = len;
1353 qname.hash = full_name_hash(name, len);
1354
1355 child = d_lookup(dir, &qname);
1356 if (!child) {
1357 struct dentry *new;
1358 new = d_alloc(dir, &qname);
1359 if (new) {
1360 child = instantiate(dir->d_inode, new, task, ptr);
1361 if (child)
1362 dput(new);
1363 else
1364 child = new;
1365 }
1366 }
1367 if (!child || IS_ERR(child) || !child->d_inode)
1368 goto end_instantiate;
1369 inode = child->d_inode;
1370 if (inode) {
1371 ino = inode->i_ino;
1372 type = inode->i_mode >> 12;
1373 }
1374 dput(child);
1375 end_instantiate:
1376 if (!ino)
1377 ino = find_inode_number(dir, &qname);
1378 if (!ino)
1379 ino = 1;
1380 return filldir(dirent, name, len, filp->f_pos, ino, type);
1381 }
1382
1383 static unsigned name_to_int(struct dentry *dentry)
1384 {
1385 const char *name = dentry->d_name.name;
1386 int len = dentry->d_name.len;
1387 unsigned n = 0;
1388
1389 if (len > 1 && *name == '0')
1390 goto out;
1391 while (len-- > 0) {
1392 unsigned c = *name++ - '0';
1393 if (c > 9)
1394 goto out;
1395 if (n >= (~0U-9)/10)
1396 goto out;
1397 n *= 10;
1398 n += c;
1399 }
1400 return n;
1401 out:
1402 return ~0U;
1403 }
1404
1405 #define PROC_FDINFO_MAX 64
1406
1407 static int proc_fd_info(struct inode *inode, struct dentry **dentry,
1408 struct vfsmount **mnt, char *info)
1409 {
1410 struct task_struct *task = get_proc_task(inode);
1411 struct files_struct *files = NULL;
1412 struct file *file;
1413 int fd = proc_fd(inode);
1414
1415 if (task) {
1416 files = get_files_struct(task);
1417 put_task_struct(task);
1418 }
1419 if (files) {
1420 /*
1421 * We are not taking a ref to the file structure, so we must
1422 * hold ->file_lock.
1423 */
1424 spin_lock(&files->file_lock);
1425 file = fcheck_files(files, fd);
1426 if (file) {
1427 if (mnt)
1428 *mnt = mntget(file->f_path.mnt);
1429 if (dentry)
1430 *dentry = dget(file->f_path.dentry);
1431 if (info)
1432 snprintf(info, PROC_FDINFO_MAX,
1433 "pos:\t%lli\n"
1434 "flags:\t0%o\n",
1435 (long long) file->f_pos,
1436 file->f_flags);
1437 spin_unlock(&files->file_lock);
1438 put_files_struct(files);
1439 return 0;
1440 }
1441 spin_unlock(&files->file_lock);
1442 put_files_struct(files);
1443 }
1444 return -ENOENT;
1445 }
1446
1447 static int proc_fd_link(struct inode *inode, struct dentry **dentry,
1448 struct vfsmount **mnt)
1449 {
1450 return proc_fd_info(inode, dentry, mnt, NULL);
1451 }
1452
1453 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1454 {
1455 struct inode *inode = dentry->d_inode;
1456 struct task_struct *task = get_proc_task(inode);
1457 int fd = proc_fd(inode);
1458 struct files_struct *files;
1459
1460 if (task) {
1461 files = get_files_struct(task);
1462 if (files) {
1463 rcu_read_lock();
1464 if (fcheck_files(files, fd)) {
1465 rcu_read_unlock();
1466 put_files_struct(files);
1467 if (task_dumpable(task)) {
1468 inode->i_uid = task->euid;
1469 inode->i_gid = task->egid;
1470 } else {
1471 inode->i_uid = 0;
1472 inode->i_gid = 0;
1473 }
1474 inode->i_mode &= ~(S_ISUID | S_ISGID);
1475 security_task_to_inode(task, inode);
1476 put_task_struct(task);
1477 return 1;
1478 }
1479 rcu_read_unlock();
1480 put_files_struct(files);
1481 }
1482 put_task_struct(task);
1483 }
1484 d_drop(dentry);
1485 return 0;
1486 }
1487
1488 static struct dentry_operations tid_fd_dentry_operations =
1489 {
1490 .d_revalidate = tid_fd_revalidate,
1491 .d_delete = pid_delete_dentry,
1492 };
1493
1494 static struct dentry *proc_fd_instantiate(struct inode *dir,
1495 struct dentry *dentry, struct task_struct *task, const void *ptr)
1496 {
1497 unsigned fd = *(const unsigned *)ptr;
1498 struct file *file;
1499 struct files_struct *files;
1500 struct inode *inode;
1501 struct proc_inode *ei;
1502 struct dentry *error = ERR_PTR(-ENOENT);
1503
1504 inode = proc_pid_make_inode(dir->i_sb, task);
1505 if (!inode)
1506 goto out;
1507 ei = PROC_I(inode);
1508 ei->fd = fd;
1509 files = get_files_struct(task);
1510 if (!files)
1511 goto out_iput;
1512 inode->i_mode = S_IFLNK;
1513
1514 /*
1515 * We are not taking a ref to the file structure, so we must
1516 * hold ->file_lock.
1517 */
1518 spin_lock(&files->file_lock);
1519 file = fcheck_files(files, fd);
1520 if (!file)
1521 goto out_unlock;
1522 if (file->f_mode & 1)
1523 inode->i_mode |= S_IRUSR | S_IXUSR;
1524 if (file->f_mode & 2)
1525 inode->i_mode |= S_IWUSR | S_IXUSR;
1526 spin_unlock(&files->file_lock);
1527 put_files_struct(files);
1528
1529 inode->i_op = &proc_pid_link_inode_operations;
1530 inode->i_size = 64;
1531 ei->op.proc_get_link = proc_fd_link;
1532 dentry->d_op = &tid_fd_dentry_operations;
1533 d_add(dentry, inode);
1534 /* Close the race of the process dying before we return the dentry */
1535 if (tid_fd_revalidate(dentry, NULL))
1536 error = NULL;
1537
1538 out:
1539 return error;
1540 out_unlock:
1541 spin_unlock(&files->file_lock);
1542 put_files_struct(files);
1543 out_iput:
1544 iput(inode);
1545 goto out;
1546 }
1547
1548 static struct dentry *proc_lookupfd_common(struct inode *dir,
1549 struct dentry *dentry,
1550 instantiate_t instantiate)
1551 {
1552 struct task_struct *task = get_proc_task(dir);
1553 unsigned fd = name_to_int(dentry);
1554 struct dentry *result = ERR_PTR(-ENOENT);
1555
1556 if (!task)
1557 goto out_no_task;
1558 if (fd == ~0U)
1559 goto out;
1560
1561 result = instantiate(dir, dentry, task, &fd);
1562 out:
1563 put_task_struct(task);
1564 out_no_task:
1565 return result;
1566 }
1567
1568 static int proc_readfd_common(struct file * filp, void * dirent,
1569 filldir_t filldir, instantiate_t instantiate)
1570 {
1571 struct dentry *dentry = filp->f_path.dentry;
1572 struct inode *inode = dentry->d_inode;
1573 struct task_struct *p = get_proc_task(inode);
1574 unsigned int fd, ino;
1575 int retval;
1576 struct files_struct * files;
1577 struct fdtable *fdt;
1578
1579 retval = -ENOENT;
1580 if (!p)
1581 goto out_no_task;
1582 retval = 0;
1583
1584 fd = filp->f_pos;
1585 switch (fd) {
1586 case 0:
1587 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1588 goto out;
1589 filp->f_pos++;
1590 case 1:
1591 ino = parent_ino(dentry);
1592 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1593 goto out;
1594 filp->f_pos++;
1595 default:
1596 files = get_files_struct(p);
1597 if (!files)
1598 goto out;
1599 rcu_read_lock();
1600 fdt = files_fdtable(files);
1601 for (fd = filp->f_pos-2;
1602 fd < fdt->max_fds;
1603 fd++, filp->f_pos++) {
1604 char name[PROC_NUMBUF];
1605 int len;
1606
1607 if (!fcheck_files(files, fd))
1608 continue;
1609 rcu_read_unlock();
1610
1611 len = snprintf(name, sizeof(name), "%d", fd);
1612 if (proc_fill_cache(filp, dirent, filldir,
1613 name, len, instantiate,
1614 p, &fd) < 0) {
1615 rcu_read_lock();
1616 break;
1617 }
1618 rcu_read_lock();
1619 }
1620 rcu_read_unlock();
1621 put_files_struct(files);
1622 }
1623 out:
1624 put_task_struct(p);
1625 out_no_task:
1626 return retval;
1627 }
1628
1629 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1630 struct nameidata *nd)
1631 {
1632 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1633 }
1634
1635 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1636 {
1637 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1638 }
1639
1640 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1641 size_t len, loff_t *ppos)
1642 {
1643 char tmp[PROC_FDINFO_MAX];
1644 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
1645 if (!err)
1646 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1647 return err;
1648 }
1649
1650 static const struct file_operations proc_fdinfo_file_operations = {
1651 .open = nonseekable_open,
1652 .read = proc_fdinfo_read,
1653 };
1654
1655 static const struct file_operations proc_fd_operations = {
1656 .read = generic_read_dir,
1657 .readdir = proc_readfd,
1658 };
1659
1660 /*
1661 * /proc/pid/fd needs a special permission handler so that a process can still
1662 * access /proc/self/fd after it has executed a setuid().
1663 */
1664 static int proc_fd_permission(struct inode *inode, int mask,
1665 struct nameidata *nd)
1666 {
1667 int rv;
1668
1669 rv = generic_permission(inode, mask, NULL);
1670 if (rv == 0)
1671 return 0;
1672 if (task_pid(current) == proc_pid(inode))
1673 rv = 0;
1674 return rv;
1675 }
1676
1677 /*
1678 * proc directories can do almost nothing..
1679 */
1680 static const struct inode_operations proc_fd_inode_operations = {
1681 .lookup = proc_lookupfd,
1682 .permission = proc_fd_permission,
1683 .setattr = proc_setattr,
1684 };
1685
1686 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1687 struct dentry *dentry, struct task_struct *task, const void *ptr)
1688 {
1689 unsigned fd = *(unsigned *)ptr;
1690 struct inode *inode;
1691 struct proc_inode *ei;
1692 struct dentry *error = ERR_PTR(-ENOENT);
1693
1694 inode = proc_pid_make_inode(dir->i_sb, task);
1695 if (!inode)
1696 goto out;
1697 ei = PROC_I(inode);
1698 ei->fd = fd;
1699 inode->i_mode = S_IFREG | S_IRUSR;
1700 inode->i_fop = &proc_fdinfo_file_operations;
1701 dentry->d_op = &tid_fd_dentry_operations;
1702 d_add(dentry, inode);
1703 /* Close the race of the process dying before we return the dentry */
1704 if (tid_fd_revalidate(dentry, NULL))
1705 error = NULL;
1706
1707 out:
1708 return error;
1709 }
1710
1711 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1712 struct dentry *dentry,
1713 struct nameidata *nd)
1714 {
1715 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1716 }
1717
1718 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1719 {
1720 return proc_readfd_common(filp, dirent, filldir,
1721 proc_fdinfo_instantiate);
1722 }
1723
1724 static const struct file_operations proc_fdinfo_operations = {
1725 .read = generic_read_dir,
1726 .readdir = proc_readfdinfo,
1727 };
1728
1729 /*
1730 * proc directories can do almost nothing..
1731 */
1732 static const struct inode_operations proc_fdinfo_inode_operations = {
1733 .lookup = proc_lookupfdinfo,
1734 .setattr = proc_setattr,
1735 };
1736
1737
1738 static struct dentry *proc_pident_instantiate(struct inode *dir,
1739 struct dentry *dentry, struct task_struct *task, const void *ptr)
1740 {
1741 const struct pid_entry *p = ptr;
1742 struct inode *inode;
1743 struct proc_inode *ei;
1744 struct dentry *error = ERR_PTR(-EINVAL);
1745
1746 inode = proc_pid_make_inode(dir->i_sb, task);
1747 if (!inode)
1748 goto out;
1749
1750 ei = PROC_I(inode);
1751 inode->i_mode = p->mode;
1752 if (S_ISDIR(inode->i_mode))
1753 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1754 if (p->iop)
1755 inode->i_op = p->iop;
1756 if (p->fop)
1757 inode->i_fop = p->fop;
1758 ei->op = p->op;
1759 dentry->d_op = &pid_dentry_operations;
1760 d_add(dentry, inode);
1761 /* Close the race of the process dying before we return the dentry */
1762 if (pid_revalidate(dentry, NULL))
1763 error = NULL;
1764 out:
1765 return error;
1766 }
1767
1768 static struct dentry *proc_pident_lookup(struct inode *dir,
1769 struct dentry *dentry,
1770 const struct pid_entry *ents,
1771 unsigned int nents)
1772 {
1773 struct inode *inode;
1774 struct dentry *error;
1775 struct task_struct *task = get_proc_task(dir);
1776 const struct pid_entry *p, *last;
1777
1778 error = ERR_PTR(-ENOENT);
1779 inode = NULL;
1780
1781 if (!task)
1782 goto out_no_task;
1783
1784 /*
1785 * Yes, it does not scale. And it should not. Don't add
1786 * new entries into /proc/<tgid>/ without very good reasons.
1787 */
1788 last = &ents[nents - 1];
1789 for (p = ents; p <= last; p++) {
1790 if (p->len != dentry->d_name.len)
1791 continue;
1792 if (!memcmp(dentry->d_name.name, p->name, p->len))
1793 break;
1794 }
1795 if (p > last)
1796 goto out;
1797
1798 error = proc_pident_instantiate(dir, dentry, task, p);
1799 out:
1800 put_task_struct(task);
1801 out_no_task:
1802 return error;
1803 }
1804
1805 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1806 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1807 {
1808 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1809 proc_pident_instantiate, task, p);
1810 }
1811
1812 static int proc_pident_readdir(struct file *filp,
1813 void *dirent, filldir_t filldir,
1814 const struct pid_entry *ents, unsigned int nents)
1815 {
1816 int i;
1817 struct dentry *dentry = filp->f_path.dentry;
1818 struct inode *inode = dentry->d_inode;
1819 struct task_struct *task = get_proc_task(inode);
1820 const struct pid_entry *p, *last;
1821 ino_t ino;
1822 int ret;
1823
1824 ret = -ENOENT;
1825 if (!task)
1826 goto out_no_task;
1827
1828 ret = 0;
1829 i = filp->f_pos;
1830 switch (i) {
1831 case 0:
1832 ino = inode->i_ino;
1833 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1834 goto out;
1835 i++;
1836 filp->f_pos++;
1837 /* fall through */
1838 case 1:
1839 ino = parent_ino(dentry);
1840 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1841 goto out;
1842 i++;
1843 filp->f_pos++;
1844 /* fall through */
1845 default:
1846 i -= 2;
1847 if (i >= nents) {
1848 ret = 1;
1849 goto out;
1850 }
1851 p = ents + i;
1852 last = &ents[nents - 1];
1853 while (p <= last) {
1854 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1855 goto out;
1856 filp->f_pos++;
1857 p++;
1858 }
1859 }
1860
1861 ret = 1;
1862 out:
1863 put_task_struct(task);
1864 out_no_task:
1865 return ret;
1866 }
1867
1868 #ifdef CONFIG_SECURITY
1869 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1870 size_t count, loff_t *ppos)
1871 {
1872 struct inode * inode = file->f_path.dentry->d_inode;
1873 char *p = NULL;
1874 ssize_t length;
1875 struct task_struct *task = get_proc_task(inode);
1876
1877 if (!task)
1878 return -ESRCH;
1879
1880 length = security_getprocattr(task,
1881 (char*)file->f_path.dentry->d_name.name,
1882 &p);
1883 put_task_struct(task);
1884 if (length > 0)
1885 length = simple_read_from_buffer(buf, count, ppos, p, length);
1886 kfree(p);
1887 return length;
1888 }
1889
1890 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1891 size_t count, loff_t *ppos)
1892 {
1893 struct inode * inode = file->f_path.dentry->d_inode;
1894 char *page;
1895 ssize_t length;
1896 struct task_struct *task = get_proc_task(inode);
1897
1898 length = -ESRCH;
1899 if (!task)
1900 goto out_no_task;
1901 if (count > PAGE_SIZE)
1902 count = PAGE_SIZE;
1903
1904 /* No partial writes. */
1905 length = -EINVAL;
1906 if (*ppos != 0)
1907 goto out;
1908
1909 length = -ENOMEM;
1910 page = (char*)__get_free_page(GFP_TEMPORARY);
1911 if (!page)
1912 goto out;
1913
1914 length = -EFAULT;
1915 if (copy_from_user(page, buf, count))
1916 goto out_free;
1917
1918 length = security_setprocattr(task,
1919 (char*)file->f_path.dentry->d_name.name,
1920 (void*)page, count);
1921 out_free:
1922 free_page((unsigned long) page);
1923 out:
1924 put_task_struct(task);
1925 out_no_task:
1926 return length;
1927 }
1928
1929 static const struct file_operations proc_pid_attr_operations = {
1930 .read = proc_pid_attr_read,
1931 .write = proc_pid_attr_write,
1932 };
1933
1934 static const struct pid_entry attr_dir_stuff[] = {
1935 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1936 REG("prev", S_IRUGO, pid_attr),
1937 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1938 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1939 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1940 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1941 };
1942
1943 static int proc_attr_dir_readdir(struct file * filp,
1944 void * dirent, filldir_t filldir)
1945 {
1946 return proc_pident_readdir(filp,dirent,filldir,
1947 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1948 }
1949
1950 static const struct file_operations proc_attr_dir_operations = {
1951 .read = generic_read_dir,
1952 .readdir = proc_attr_dir_readdir,
1953 };
1954
1955 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
1956 struct dentry *dentry, struct nameidata *nd)
1957 {
1958 return proc_pident_lookup(dir, dentry,
1959 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
1960 }
1961
1962 static const struct inode_operations proc_attr_dir_inode_operations = {
1963 .lookup = proc_attr_dir_lookup,
1964 .getattr = pid_getattr,
1965 .setattr = proc_setattr,
1966 };
1967
1968 #endif
1969
1970 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1971 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
1972 size_t count, loff_t *ppos)
1973 {
1974 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1975 struct mm_struct *mm;
1976 char buffer[PROC_NUMBUF];
1977 size_t len;
1978 int ret;
1979
1980 if (!task)
1981 return -ESRCH;
1982
1983 ret = 0;
1984 mm = get_task_mm(task);
1985 if (mm) {
1986 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
1987 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
1988 MMF_DUMP_FILTER_SHIFT));
1989 mmput(mm);
1990 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
1991 }
1992
1993 put_task_struct(task);
1994
1995 return ret;
1996 }
1997
1998 static ssize_t proc_coredump_filter_write(struct file *file,
1999 const char __user *buf,
2000 size_t count,
2001 loff_t *ppos)
2002 {
2003 struct task_struct *task;
2004 struct mm_struct *mm;
2005 char buffer[PROC_NUMBUF], *end;
2006 unsigned int val;
2007 int ret;
2008 int i;
2009 unsigned long mask;
2010
2011 ret = -EFAULT;
2012 memset(buffer, 0, sizeof(buffer));
2013 if (count > sizeof(buffer) - 1)
2014 count = sizeof(buffer) - 1;
2015 if (copy_from_user(buffer, buf, count))
2016 goto out_no_task;
2017
2018 ret = -EINVAL;
2019 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2020 if (*end == '\n')
2021 end++;
2022 if (end - buffer == 0)
2023 goto out_no_task;
2024
2025 ret = -ESRCH;
2026 task = get_proc_task(file->f_dentry->d_inode);
2027 if (!task)
2028 goto out_no_task;
2029
2030 ret = end - buffer;
2031 mm = get_task_mm(task);
2032 if (!mm)
2033 goto out_no_mm;
2034
2035 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2036 if (val & mask)
2037 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2038 else
2039 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2040 }
2041
2042 mmput(mm);
2043 out_no_mm:
2044 put_task_struct(task);
2045 out_no_task:
2046 return ret;
2047 }
2048
2049 static const struct file_operations proc_coredump_filter_operations = {
2050 .read = proc_coredump_filter_read,
2051 .write = proc_coredump_filter_write,
2052 };
2053 #endif
2054
2055 /*
2056 * /proc/self:
2057 */
2058 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2059 int buflen)
2060 {
2061 char tmp[PROC_NUMBUF];
2062 sprintf(tmp, "%d", task_tgid_vnr(current));
2063 return vfs_readlink(dentry,buffer,buflen,tmp);
2064 }
2065
2066 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2067 {
2068 char tmp[PROC_NUMBUF];
2069 sprintf(tmp, "%d", task_tgid_vnr(current));
2070 return ERR_PTR(vfs_follow_link(nd,tmp));
2071 }
2072
2073 static const struct inode_operations proc_self_inode_operations = {
2074 .readlink = proc_self_readlink,
2075 .follow_link = proc_self_follow_link,
2076 };
2077
2078 /*
2079 * proc base
2080 *
2081 * These are the directory entries in the root directory of /proc
2082 * that properly belong to the /proc filesystem, as they describe
2083 * describe something that is process related.
2084 */
2085 static const struct pid_entry proc_base_stuff[] = {
2086 NOD("self", S_IFLNK|S_IRWXUGO,
2087 &proc_self_inode_operations, NULL, {}),
2088 };
2089
2090 /*
2091 * Exceptional case: normally we are not allowed to unhash a busy
2092 * directory. In this case, however, we can do it - no aliasing problems
2093 * due to the way we treat inodes.
2094 */
2095 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2096 {
2097 struct inode *inode = dentry->d_inode;
2098 struct task_struct *task = get_proc_task(inode);
2099 if (task) {
2100 put_task_struct(task);
2101 return 1;
2102 }
2103 d_drop(dentry);
2104 return 0;
2105 }
2106
2107 static struct dentry_operations proc_base_dentry_operations =
2108 {
2109 .d_revalidate = proc_base_revalidate,
2110 .d_delete = pid_delete_dentry,
2111 };
2112
2113 static struct dentry *proc_base_instantiate(struct inode *dir,
2114 struct dentry *dentry, struct task_struct *task, const void *ptr)
2115 {
2116 const struct pid_entry *p = ptr;
2117 struct inode *inode;
2118 struct proc_inode *ei;
2119 struct dentry *error = ERR_PTR(-EINVAL);
2120
2121 /* Allocate the inode */
2122 error = ERR_PTR(-ENOMEM);
2123 inode = new_inode(dir->i_sb);
2124 if (!inode)
2125 goto out;
2126
2127 /* Initialize the inode */
2128 ei = PROC_I(inode);
2129 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2130
2131 /*
2132 * grab the reference to the task.
2133 */
2134 ei->pid = get_task_pid(task, PIDTYPE_PID);
2135 if (!ei->pid)
2136 goto out_iput;
2137
2138 inode->i_uid = 0;
2139 inode->i_gid = 0;
2140 inode->i_mode = p->mode;
2141 if (S_ISDIR(inode->i_mode))
2142 inode->i_nlink = 2;
2143 if (S_ISLNK(inode->i_mode))
2144 inode->i_size = 64;
2145 if (p->iop)
2146 inode->i_op = p->iop;
2147 if (p->fop)
2148 inode->i_fop = p->fop;
2149 ei->op = p->op;
2150 dentry->d_op = &proc_base_dentry_operations;
2151 d_add(dentry, inode);
2152 error = NULL;
2153 out:
2154 return error;
2155 out_iput:
2156 iput(inode);
2157 goto out;
2158 }
2159
2160 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2161 {
2162 struct dentry *error;
2163 struct task_struct *task = get_proc_task(dir);
2164 const struct pid_entry *p, *last;
2165
2166 error = ERR_PTR(-ENOENT);
2167
2168 if (!task)
2169 goto out_no_task;
2170
2171 /* Lookup the directory entry */
2172 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2173 for (p = proc_base_stuff; p <= last; p++) {
2174 if (p->len != dentry->d_name.len)
2175 continue;
2176 if (!memcmp(dentry->d_name.name, p->name, p->len))
2177 break;
2178 }
2179 if (p > last)
2180 goto out;
2181
2182 error = proc_base_instantiate(dir, dentry, task, p);
2183
2184 out:
2185 put_task_struct(task);
2186 out_no_task:
2187 return error;
2188 }
2189
2190 static int proc_base_fill_cache(struct file *filp, void *dirent,
2191 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2192 {
2193 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2194 proc_base_instantiate, task, p);
2195 }
2196
2197 #ifdef CONFIG_TASK_IO_ACCOUNTING
2198 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2199 {
2200 return sprintf(buffer,
2201 #ifdef CONFIG_TASK_XACCT
2202 "rchar: %llu\n"
2203 "wchar: %llu\n"
2204 "syscr: %llu\n"
2205 "syscw: %llu\n"
2206 #endif
2207 "read_bytes: %llu\n"
2208 "write_bytes: %llu\n"
2209 "cancelled_write_bytes: %llu\n",
2210 #ifdef CONFIG_TASK_XACCT
2211 (unsigned long long)task->rchar,
2212 (unsigned long long)task->wchar,
2213 (unsigned long long)task->syscr,
2214 (unsigned long long)task->syscw,
2215 #endif
2216 (unsigned long long)task->ioac.read_bytes,
2217 (unsigned long long)task->ioac.write_bytes,
2218 (unsigned long long)task->ioac.cancelled_write_bytes);
2219 }
2220 #endif
2221
2222 /*
2223 * Thread groups
2224 */
2225 static const struct file_operations proc_task_operations;
2226 static const struct inode_operations proc_task_inode_operations;
2227
2228 static const struct pid_entry tgid_base_stuff[] = {
2229 DIR("task", S_IRUGO|S_IXUGO, task),
2230 DIR("fd", S_IRUSR|S_IXUSR, fd),
2231 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2232 REG("environ", S_IRUSR, environ),
2233 INF("auxv", S_IRUSR, pid_auxv),
2234 INF("status", S_IRUGO, pid_status),
2235 INF("limits", S_IRUSR, pid_limits),
2236 #ifdef CONFIG_SCHED_DEBUG
2237 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2238 #endif
2239 INF("cmdline", S_IRUGO, pid_cmdline),
2240 INF("stat", S_IRUGO, tgid_stat),
2241 INF("statm", S_IRUGO, pid_statm),
2242 REG("maps", S_IRUGO, maps),
2243 #ifdef CONFIG_NUMA
2244 REG("numa_maps", S_IRUGO, numa_maps),
2245 #endif
2246 REG("mem", S_IRUSR|S_IWUSR, mem),
2247 LNK("cwd", cwd),
2248 LNK("root", root),
2249 LNK("exe", exe),
2250 REG("mounts", S_IRUGO, mounts),
2251 REG("mountstats", S_IRUSR, mountstats),
2252 #ifdef CONFIG_MMU
2253 REG("clear_refs", S_IWUSR, clear_refs),
2254 REG("smaps", S_IRUGO, smaps),
2255 #endif
2256 #ifdef CONFIG_SECURITY
2257 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2258 #endif
2259 #ifdef CONFIG_KALLSYMS
2260 INF("wchan", S_IRUGO, pid_wchan),
2261 #endif
2262 #ifdef CONFIG_SCHEDSTATS
2263 INF("schedstat", S_IRUGO, pid_schedstat),
2264 #endif
2265 #ifdef CONFIG_LATENCYTOP
2266 REG("latency", S_IRUGO, lstats),
2267 #endif
2268 #ifdef CONFIG_PROC_PID_CPUSET
2269 REG("cpuset", S_IRUGO, cpuset),
2270 #endif
2271 #ifdef CONFIG_CGROUPS
2272 REG("cgroup", S_IRUGO, cgroup),
2273 #endif
2274 INF("oom_score", S_IRUGO, oom_score),
2275 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2276 #ifdef CONFIG_AUDITSYSCALL
2277 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2278 #endif
2279 #ifdef CONFIG_FAULT_INJECTION
2280 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2281 #endif
2282 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2283 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2284 #endif
2285 #ifdef CONFIG_TASK_IO_ACCOUNTING
2286 INF("io", S_IRUGO, pid_io_accounting),
2287 #endif
2288 };
2289
2290 static int proc_tgid_base_readdir(struct file * filp,
2291 void * dirent, filldir_t filldir)
2292 {
2293 return proc_pident_readdir(filp,dirent,filldir,
2294 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2295 }
2296
2297 static const struct file_operations proc_tgid_base_operations = {
2298 .read = generic_read_dir,
2299 .readdir = proc_tgid_base_readdir,
2300 };
2301
2302 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2303 return proc_pident_lookup(dir, dentry,
2304 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2305 }
2306
2307 static const struct inode_operations proc_tgid_base_inode_operations = {
2308 .lookup = proc_tgid_base_lookup,
2309 .getattr = pid_getattr,
2310 .setattr = proc_setattr,
2311 };
2312
2313 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2314 {
2315 struct dentry *dentry, *leader, *dir;
2316 char buf[PROC_NUMBUF];
2317 struct qstr name;
2318
2319 name.name = buf;
2320 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2321 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2322 if (dentry) {
2323 shrink_dcache_parent(dentry);
2324 d_drop(dentry);
2325 dput(dentry);
2326 }
2327
2328 if (tgid == 0)
2329 goto out;
2330
2331 name.name = buf;
2332 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2333 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2334 if (!leader)
2335 goto out;
2336
2337 name.name = "task";
2338 name.len = strlen(name.name);
2339 dir = d_hash_and_lookup(leader, &name);
2340 if (!dir)
2341 goto out_put_leader;
2342
2343 name.name = buf;
2344 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2345 dentry = d_hash_and_lookup(dir, &name);
2346 if (dentry) {
2347 shrink_dcache_parent(dentry);
2348 d_drop(dentry);
2349 dput(dentry);
2350 }
2351
2352 dput(dir);
2353 out_put_leader:
2354 dput(leader);
2355 out:
2356 return;
2357 }
2358
2359 /**
2360 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2361 * @task: task that should be flushed.
2362 *
2363 * When flushing dentries from proc, one needs to flush them from global
2364 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2365 * in. This call is supposed to do all of this job.
2366 *
2367 * Looks in the dcache for
2368 * /proc/@pid
2369 * /proc/@tgid/task/@pid
2370 * if either directory is present flushes it and all of it'ts children
2371 * from the dcache.
2372 *
2373 * It is safe and reasonable to cache /proc entries for a task until
2374 * that task exits. After that they just clog up the dcache with
2375 * useless entries, possibly causing useful dcache entries to be
2376 * flushed instead. This routine is proved to flush those useless
2377 * dcache entries at process exit time.
2378 *
2379 * NOTE: This routine is just an optimization so it does not guarantee
2380 * that no dcache entries will exist at process exit time it
2381 * just makes it very unlikely that any will persist.
2382 */
2383
2384 void proc_flush_task(struct task_struct *task)
2385 {
2386 int i;
2387 struct pid *pid, *tgid = NULL;
2388 struct upid *upid;
2389
2390 pid = task_pid(task);
2391 if (thread_group_leader(task))
2392 tgid = task_tgid(task);
2393
2394 for (i = 0; i <= pid->level; i++) {
2395 upid = &pid->numbers[i];
2396 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2397 tgid ? tgid->numbers[i].nr : 0);
2398 }
2399
2400 upid = &pid->numbers[pid->level];
2401 if (upid->nr == 1)
2402 pid_ns_release_proc(upid->ns);
2403 }
2404
2405 static struct dentry *proc_pid_instantiate(struct inode *dir,
2406 struct dentry * dentry,
2407 struct task_struct *task, const void *ptr)
2408 {
2409 struct dentry *error = ERR_PTR(-ENOENT);
2410 struct inode *inode;
2411
2412 inode = proc_pid_make_inode(dir->i_sb, task);
2413 if (!inode)
2414 goto out;
2415
2416 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2417 inode->i_op = &proc_tgid_base_inode_operations;
2418 inode->i_fop = &proc_tgid_base_operations;
2419 inode->i_flags|=S_IMMUTABLE;
2420 inode->i_nlink = 5;
2421 #ifdef CONFIG_SECURITY
2422 inode->i_nlink += 1;
2423 #endif
2424
2425 dentry->d_op = &pid_dentry_operations;
2426
2427 d_add(dentry, inode);
2428 /* Close the race of the process dying before we return the dentry */
2429 if (pid_revalidate(dentry, NULL))
2430 error = NULL;
2431 out:
2432 return error;
2433 }
2434
2435 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2436 {
2437 struct dentry *result = ERR_PTR(-ENOENT);
2438 struct task_struct *task;
2439 unsigned tgid;
2440 struct pid_namespace *ns;
2441
2442 result = proc_base_lookup(dir, dentry);
2443 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2444 goto out;
2445
2446 tgid = name_to_int(dentry);
2447 if (tgid == ~0U)
2448 goto out;
2449
2450 ns = dentry->d_sb->s_fs_info;
2451 rcu_read_lock();
2452 task = find_task_by_pid_ns(tgid, ns);
2453 if (task)
2454 get_task_struct(task);
2455 rcu_read_unlock();
2456 if (!task)
2457 goto out;
2458
2459 result = proc_pid_instantiate(dir, dentry, task, NULL);
2460 put_task_struct(task);
2461 out:
2462 return result;
2463 }
2464
2465 /*
2466 * Find the first task with tgid >= tgid
2467 *
2468 */
2469 struct tgid_iter {
2470 unsigned int tgid;
2471 struct task_struct *task;
2472 };
2473 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2474 {
2475 struct pid *pid;
2476
2477 if (iter.task)
2478 put_task_struct(iter.task);
2479 rcu_read_lock();
2480 retry:
2481 iter.task = NULL;
2482 pid = find_ge_pid(iter.tgid, ns);
2483 if (pid) {
2484 iter.tgid = pid_nr_ns(pid, ns);
2485 iter.task = pid_task(pid, PIDTYPE_PID);
2486 /* What we to know is if the pid we have find is the
2487 * pid of a thread_group_leader. Testing for task
2488 * being a thread_group_leader is the obvious thing
2489 * todo but there is a window when it fails, due to
2490 * the pid transfer logic in de_thread.
2491 *
2492 * So we perform the straight forward test of seeing
2493 * if the pid we have found is the pid of a thread
2494 * group leader, and don't worry if the task we have
2495 * found doesn't happen to be a thread group leader.
2496 * As we don't care in the case of readdir.
2497 */
2498 if (!iter.task || !has_group_leader_pid(iter.task)) {
2499 iter.tgid += 1;
2500 goto retry;
2501 }
2502 get_task_struct(iter.task);
2503 }
2504 rcu_read_unlock();
2505 return iter;
2506 }
2507
2508 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2509
2510 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2511 struct tgid_iter iter)
2512 {
2513 char name[PROC_NUMBUF];
2514 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2515 return proc_fill_cache(filp, dirent, filldir, name, len,
2516 proc_pid_instantiate, iter.task, NULL);
2517 }
2518
2519 /* for the /proc/ directory itself, after non-process stuff has been done */
2520 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2521 {
2522 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2523 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2524 struct tgid_iter iter;
2525 struct pid_namespace *ns;
2526
2527 if (!reaper)
2528 goto out_no_task;
2529
2530 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2531 const struct pid_entry *p = &proc_base_stuff[nr];
2532 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2533 goto out;
2534 }
2535
2536 ns = filp->f_dentry->d_sb->s_fs_info;
2537 iter.task = NULL;
2538 iter.tgid = filp->f_pos - TGID_OFFSET;
2539 for (iter = next_tgid(ns, iter);
2540 iter.task;
2541 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2542 filp->f_pos = iter.tgid + TGID_OFFSET;
2543 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2544 put_task_struct(iter.task);
2545 goto out;
2546 }
2547 }
2548 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2549 out:
2550 put_task_struct(reaper);
2551 out_no_task:
2552 return 0;
2553 }
2554
2555 /*
2556 * Tasks
2557 */
2558 static const struct pid_entry tid_base_stuff[] = {
2559 DIR("fd", S_IRUSR|S_IXUSR, fd),
2560 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2561 REG("environ", S_IRUSR, environ),
2562 INF("auxv", S_IRUSR, pid_auxv),
2563 INF("status", S_IRUGO, pid_status),
2564 INF("limits", S_IRUSR, pid_limits),
2565 #ifdef CONFIG_SCHED_DEBUG
2566 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2567 #endif
2568 INF("cmdline", S_IRUGO, pid_cmdline),
2569 INF("stat", S_IRUGO, tid_stat),
2570 INF("statm", S_IRUGO, pid_statm),
2571 REG("maps", S_IRUGO, maps),
2572 #ifdef CONFIG_NUMA
2573 REG("numa_maps", S_IRUGO, numa_maps),
2574 #endif
2575 REG("mem", S_IRUSR|S_IWUSR, mem),
2576 LNK("cwd", cwd),
2577 LNK("root", root),
2578 LNK("exe", exe),
2579 REG("mounts", S_IRUGO, mounts),
2580 #ifdef CONFIG_MMU
2581 REG("clear_refs", S_IWUSR, clear_refs),
2582 REG("smaps", S_IRUGO, smaps),
2583 #endif
2584 #ifdef CONFIG_SECURITY
2585 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2586 #endif
2587 #ifdef CONFIG_KALLSYMS
2588 INF("wchan", S_IRUGO, pid_wchan),
2589 #endif
2590 #ifdef CONFIG_SCHEDSTATS
2591 INF("schedstat", S_IRUGO, pid_schedstat),
2592 #endif
2593 #ifdef CONFIG_LATENCYTOP
2594 REG("latency", S_IRUGO, lstats),
2595 #endif
2596 #ifdef CONFIG_PROC_PID_CPUSET
2597 REG("cpuset", S_IRUGO, cpuset),
2598 #endif
2599 #ifdef CONFIG_CGROUPS
2600 REG("cgroup", S_IRUGO, cgroup),
2601 #endif
2602 INF("oom_score", S_IRUGO, oom_score),
2603 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2604 #ifdef CONFIG_AUDITSYSCALL
2605 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2606 #endif
2607 #ifdef CONFIG_FAULT_INJECTION
2608 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2609 #endif
2610 };
2611
2612 static int proc_tid_base_readdir(struct file * filp,
2613 void * dirent, filldir_t filldir)
2614 {
2615 return proc_pident_readdir(filp,dirent,filldir,
2616 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2617 }
2618
2619 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2620 return proc_pident_lookup(dir, dentry,
2621 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2622 }
2623
2624 static const struct file_operations proc_tid_base_operations = {
2625 .read = generic_read_dir,
2626 .readdir = proc_tid_base_readdir,
2627 };
2628
2629 static const struct inode_operations proc_tid_base_inode_operations = {
2630 .lookup = proc_tid_base_lookup,
2631 .getattr = pid_getattr,
2632 .setattr = proc_setattr,
2633 };
2634
2635 static struct dentry *proc_task_instantiate(struct inode *dir,
2636 struct dentry *dentry, struct task_struct *task, const void *ptr)
2637 {
2638 struct dentry *error = ERR_PTR(-ENOENT);
2639 struct inode *inode;
2640 inode = proc_pid_make_inode(dir->i_sb, task);
2641
2642 if (!inode)
2643 goto out;
2644 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2645 inode->i_op = &proc_tid_base_inode_operations;
2646 inode->i_fop = &proc_tid_base_operations;
2647 inode->i_flags|=S_IMMUTABLE;
2648 inode->i_nlink = 4;
2649 #ifdef CONFIG_SECURITY
2650 inode->i_nlink += 1;
2651 #endif
2652
2653 dentry->d_op = &pid_dentry_operations;
2654
2655 d_add(dentry, inode);
2656 /* Close the race of the process dying before we return the dentry */
2657 if (pid_revalidate(dentry, NULL))
2658 error = NULL;
2659 out:
2660 return error;
2661 }
2662
2663 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2664 {
2665 struct dentry *result = ERR_PTR(-ENOENT);
2666 struct task_struct *task;
2667 struct task_struct *leader = get_proc_task(dir);
2668 unsigned tid;
2669 struct pid_namespace *ns;
2670
2671 if (!leader)
2672 goto out_no_task;
2673
2674 tid = name_to_int(dentry);
2675 if (tid == ~0U)
2676 goto out;
2677
2678 ns = dentry->d_sb->s_fs_info;
2679 rcu_read_lock();
2680 task = find_task_by_pid_ns(tid, ns);
2681 if (task)
2682 get_task_struct(task);
2683 rcu_read_unlock();
2684 if (!task)
2685 goto out;
2686 if (!same_thread_group(leader, task))
2687 goto out_drop_task;
2688
2689 result = proc_task_instantiate(dir, dentry, task, NULL);
2690 out_drop_task:
2691 put_task_struct(task);
2692 out:
2693 put_task_struct(leader);
2694 out_no_task:
2695 return result;
2696 }
2697
2698 /*
2699 * Find the first tid of a thread group to return to user space.
2700 *
2701 * Usually this is just the thread group leader, but if the users
2702 * buffer was too small or there was a seek into the middle of the
2703 * directory we have more work todo.
2704 *
2705 * In the case of a short read we start with find_task_by_pid.
2706 *
2707 * In the case of a seek we start with the leader and walk nr
2708 * threads past it.
2709 */
2710 static struct task_struct *first_tid(struct task_struct *leader,
2711 int tid, int nr, struct pid_namespace *ns)
2712 {
2713 struct task_struct *pos;
2714
2715 rcu_read_lock();
2716 /* Attempt to start with the pid of a thread */
2717 if (tid && (nr > 0)) {
2718 pos = find_task_by_pid_ns(tid, ns);
2719 if (pos && (pos->group_leader == leader))
2720 goto found;
2721 }
2722
2723 /* If nr exceeds the number of threads there is nothing todo */
2724 pos = NULL;
2725 if (nr && nr >= get_nr_threads(leader))
2726 goto out;
2727
2728 /* If we haven't found our starting place yet start
2729 * with the leader and walk nr threads forward.
2730 */
2731 for (pos = leader; nr > 0; --nr) {
2732 pos = next_thread(pos);
2733 if (pos == leader) {
2734 pos = NULL;
2735 goto out;
2736 }
2737 }
2738 found:
2739 get_task_struct(pos);
2740 out:
2741 rcu_read_unlock();
2742 return pos;
2743 }
2744
2745 /*
2746 * Find the next thread in the thread list.
2747 * Return NULL if there is an error or no next thread.
2748 *
2749 * The reference to the input task_struct is released.
2750 */
2751 static struct task_struct *next_tid(struct task_struct *start)
2752 {
2753 struct task_struct *pos = NULL;
2754 rcu_read_lock();
2755 if (pid_alive(start)) {
2756 pos = next_thread(start);
2757 if (thread_group_leader(pos))
2758 pos = NULL;
2759 else
2760 get_task_struct(pos);
2761 }
2762 rcu_read_unlock();
2763 put_task_struct(start);
2764 return pos;
2765 }
2766
2767 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2768 struct task_struct *task, int tid)
2769 {
2770 char name[PROC_NUMBUF];
2771 int len = snprintf(name, sizeof(name), "%d", tid);
2772 return proc_fill_cache(filp, dirent, filldir, name, len,
2773 proc_task_instantiate, task, NULL);
2774 }
2775
2776 /* for the /proc/TGID/task/ directories */
2777 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2778 {
2779 struct dentry *dentry = filp->f_path.dentry;
2780 struct inode *inode = dentry->d_inode;
2781 struct task_struct *leader = NULL;
2782 struct task_struct *task;
2783 int retval = -ENOENT;
2784 ino_t ino;
2785 int tid;
2786 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2787 struct pid_namespace *ns;
2788
2789 task = get_proc_task(inode);
2790 if (!task)
2791 goto out_no_task;
2792 rcu_read_lock();
2793 if (pid_alive(task)) {
2794 leader = task->group_leader;
2795 get_task_struct(leader);
2796 }
2797 rcu_read_unlock();
2798 put_task_struct(task);
2799 if (!leader)
2800 goto out_no_task;
2801 retval = 0;
2802
2803 switch (pos) {
2804 case 0:
2805 ino = inode->i_ino;
2806 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2807 goto out;
2808 pos++;
2809 /* fall through */
2810 case 1:
2811 ino = parent_ino(dentry);
2812 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2813 goto out;
2814 pos++;
2815 /* fall through */
2816 }
2817
2818 /* f_version caches the tgid value that the last readdir call couldn't
2819 * return. lseek aka telldir automagically resets f_version to 0.
2820 */
2821 ns = filp->f_dentry->d_sb->s_fs_info;
2822 tid = (int)filp->f_version;
2823 filp->f_version = 0;
2824 for (task = first_tid(leader, tid, pos - 2, ns);
2825 task;
2826 task = next_tid(task), pos++) {
2827 tid = task_pid_nr_ns(task, ns);
2828 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2829 /* returning this tgid failed, save it as the first
2830 * pid for the next readir call */
2831 filp->f_version = (u64)tid;
2832 put_task_struct(task);
2833 break;
2834 }
2835 }
2836 out:
2837 filp->f_pos = pos;
2838 put_task_struct(leader);
2839 out_no_task:
2840 return retval;
2841 }
2842
2843 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2844 {
2845 struct inode *inode = dentry->d_inode;
2846 struct task_struct *p = get_proc_task(inode);
2847 generic_fillattr(inode, stat);
2848
2849 if (p) {
2850 rcu_read_lock();
2851 stat->nlink += get_nr_threads(p);
2852 rcu_read_unlock();
2853 put_task_struct(p);
2854 }
2855
2856 return 0;
2857 }
2858
2859 static const struct inode_operations proc_task_inode_operations = {
2860 .lookup = proc_task_lookup,
2861 .getattr = proc_task_getattr,
2862 .setattr = proc_setattr,
2863 };
2864
2865 static const struct file_operations proc_task_operations = {
2866 .read = generic_read_dir,
2867 .readdir = proc_task_readdir,
2868 };
Stable & featurefull patchset based on Linus's git branch