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Pull bugzilla-9535 into release branch
[deliverable/linux.git] / fs / proc / base.c
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/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
92 /* Worst case buffer size needed for holding an integer. */
93 #define PROC_NUMBUF 13
94
95 struct pid_entry {
96 char *name;
97 int len;
98 mode_t mode;
99 const struct inode_operations *iop;
100 const struct file_operations *fop;
101 union proc_op op;
102 };
103
104 #define NOD(NAME, MODE, IOP, FOP, OP) { \
105 .name = (NAME), \
106 .len = sizeof(NAME) - 1, \
107 .mode = MODE, \
108 .iop = IOP, \
109 .fop = FOP, \
110 .op = OP, \
111 }
112
113 #define DIR(NAME, MODE, OTYPE) \
114 NOD(NAME, (S_IFDIR|(MODE)), \
115 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
116 {} )
117 #define LNK(NAME, OTYPE) \
118 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
119 &proc_pid_link_inode_operations, NULL, \
120 { .proc_get_link = &proc_##OTYPE##_link } )
121 #define REG(NAME, MODE, OTYPE) \
122 NOD(NAME, (S_IFREG|(MODE)), NULL, \
123 &proc_##OTYPE##_operations, {})
124 #define INF(NAME, MODE, OTYPE) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_info_file_operations, \
127 { .proc_read = &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 dentry **dentry, struct vfsmount **mnt)
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 *mnt = mntget(fs->pwdmnt);
169 *dentry = dget(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 dentry **dentry, struct vfsmount **mnt)
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 *mnt = mntget(fs->rootmnt);
190 *dentry = dget(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->state == TASK_STOPPED || task->state == TASK_TRACED) && \
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 /* The badness from the OOM killer */
314 unsigned long badness(struct task_struct *p, unsigned long uptime);
315 static int proc_oom_score(struct task_struct *task, char *buffer)
316 {
317 unsigned long points;
318 struct timespec uptime;
319
320 do_posix_clock_monotonic_gettime(&uptime);
321 read_lock(&tasklist_lock);
322 points = badness(task, uptime.tv_sec);
323 read_unlock(&tasklist_lock);
324 return sprintf(buffer, "%lu\n", points);
325 }
326
327 struct limit_names {
328 char *name;
329 char *unit;
330 };
331
332 static const struct limit_names lnames[RLIM_NLIMITS] = {
333 [RLIMIT_CPU] = {"Max cpu time", "ms"},
334 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
335 [RLIMIT_DATA] = {"Max data size", "bytes"},
336 [RLIMIT_STACK] = {"Max stack size", "bytes"},
337 [RLIMIT_CORE] = {"Max core file size", "bytes"},
338 [RLIMIT_RSS] = {"Max resident set", "bytes"},
339 [RLIMIT_NPROC] = {"Max processes", "processes"},
340 [RLIMIT_NOFILE] = {"Max open files", "files"},
341 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
342 [RLIMIT_AS] = {"Max address space", "bytes"},
343 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
344 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
345 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
346 [RLIMIT_NICE] = {"Max nice priority", NULL},
347 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
348 };
349
350 /* Display limits for a process */
351 static int proc_pid_limits(struct task_struct *task, char *buffer)
352 {
353 unsigned int i;
354 int count = 0;
355 unsigned long flags;
356 char *bufptr = buffer;
357
358 struct rlimit rlim[RLIM_NLIMITS];
359
360 rcu_read_lock();
361 if (!lock_task_sighand(task,&flags)) {
362 rcu_read_unlock();
363 return 0;
364 }
365 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
366 unlock_task_sighand(task, &flags);
367 rcu_read_unlock();
368
369 /*
370 * print the file header
371 */
372 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
373 "Limit", "Soft Limit", "Hard Limit", "Units");
374
375 for (i = 0; i < RLIM_NLIMITS; i++) {
376 if (rlim[i].rlim_cur == RLIM_INFINITY)
377 count += sprintf(&bufptr[count], "%-25s %-20s ",
378 lnames[i].name, "unlimited");
379 else
380 count += sprintf(&bufptr[count], "%-25s %-20lu ",
381 lnames[i].name, rlim[i].rlim_cur);
382
383 if (rlim[i].rlim_max == RLIM_INFINITY)
384 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
385 else
386 count += sprintf(&bufptr[count], "%-20lu ",
387 rlim[i].rlim_max);
388
389 if (lnames[i].unit)
390 count += sprintf(&bufptr[count], "%-10s\n",
391 lnames[i].unit);
392 else
393 count += sprintf(&bufptr[count], "\n");
394 }
395
396 return count;
397 }
398
399 /************************************************************************/
400 /* Here the fs part begins */
401 /************************************************************************/
402
403 /* permission checks */
404 static int proc_fd_access_allowed(struct inode *inode)
405 {
406 struct task_struct *task;
407 int allowed = 0;
408 /* Allow access to a task's file descriptors if it is us or we
409 * may use ptrace attach to the process and find out that
410 * information.
411 */
412 task = get_proc_task(inode);
413 if (task) {
414 allowed = ptrace_may_attach(task);
415 put_task_struct(task);
416 }
417 return allowed;
418 }
419
420 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
421 {
422 int error;
423 struct inode *inode = dentry->d_inode;
424
425 if (attr->ia_valid & ATTR_MODE)
426 return -EPERM;
427
428 error = inode_change_ok(inode, attr);
429 if (!error)
430 error = inode_setattr(inode, attr);
431 return error;
432 }
433
434 static const struct inode_operations proc_def_inode_operations = {
435 .setattr = proc_setattr,
436 };
437
438 extern struct seq_operations mounts_op;
439 struct proc_mounts {
440 struct seq_file m;
441 int event;
442 };
443
444 static int mounts_open(struct inode *inode, struct file *file)
445 {
446 struct task_struct *task = get_proc_task(inode);
447 struct nsproxy *nsp;
448 struct mnt_namespace *ns = NULL;
449 struct proc_mounts *p;
450 int ret = -EINVAL;
451
452 if (task) {
453 rcu_read_lock();
454 nsp = task_nsproxy(task);
455 if (nsp) {
456 ns = nsp->mnt_ns;
457 if (ns)
458 get_mnt_ns(ns);
459 }
460 rcu_read_unlock();
461
462 put_task_struct(task);
463 }
464
465 if (ns) {
466 ret = -ENOMEM;
467 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
468 if (p) {
469 file->private_data = &p->m;
470 ret = seq_open(file, &mounts_op);
471 if (!ret) {
472 p->m.private = ns;
473 p->event = ns->event;
474 return 0;
475 }
476 kfree(p);
477 }
478 put_mnt_ns(ns);
479 }
480 return ret;
481 }
482
483 static int mounts_release(struct inode *inode, struct file *file)
484 {
485 struct seq_file *m = file->private_data;
486 struct mnt_namespace *ns = m->private;
487 put_mnt_ns(ns);
488 return seq_release(inode, file);
489 }
490
491 static unsigned mounts_poll(struct file *file, poll_table *wait)
492 {
493 struct proc_mounts *p = file->private_data;
494 struct mnt_namespace *ns = p->m.private;
495 unsigned res = 0;
496
497 poll_wait(file, &ns->poll, wait);
498
499 spin_lock(&vfsmount_lock);
500 if (p->event != ns->event) {
501 p->event = ns->event;
502 res = POLLERR;
503 }
504 spin_unlock(&vfsmount_lock);
505
506 return res;
507 }
508
509 static const struct file_operations proc_mounts_operations = {
510 .open = mounts_open,
511 .read = seq_read,
512 .llseek = seq_lseek,
513 .release = mounts_release,
514 .poll = mounts_poll,
515 };
516
517 extern struct seq_operations mountstats_op;
518 static int mountstats_open(struct inode *inode, struct file *file)
519 {
520 int ret = seq_open(file, &mountstats_op);
521
522 if (!ret) {
523 struct seq_file *m = file->private_data;
524 struct nsproxy *nsp;
525 struct mnt_namespace *mnt_ns = NULL;
526 struct task_struct *task = get_proc_task(inode);
527
528 if (task) {
529 rcu_read_lock();
530 nsp = task_nsproxy(task);
531 if (nsp) {
532 mnt_ns = nsp->mnt_ns;
533 if (mnt_ns)
534 get_mnt_ns(mnt_ns);
535 }
536 rcu_read_unlock();
537
538 put_task_struct(task);
539 }
540
541 if (mnt_ns)
542 m->private = mnt_ns;
543 else {
544 seq_release(inode, file);
545 ret = -EINVAL;
546 }
547 }
548 return ret;
549 }
550
551 static const struct file_operations proc_mountstats_operations = {
552 .open = mountstats_open,
553 .read = seq_read,
554 .llseek = seq_lseek,
555 .release = mounts_release,
556 };
557
558 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
559
560 static ssize_t proc_info_read(struct file * file, char __user * buf,
561 size_t count, loff_t *ppos)
562 {
563 struct inode * inode = file->f_path.dentry->d_inode;
564 unsigned long page;
565 ssize_t length;
566 struct task_struct *task = get_proc_task(inode);
567
568 length = -ESRCH;
569 if (!task)
570 goto out_no_task;
571
572 if (count > PROC_BLOCK_SIZE)
573 count = PROC_BLOCK_SIZE;
574
575 length = -ENOMEM;
576 if (!(page = __get_free_page(GFP_TEMPORARY)))
577 goto out;
578
579 length = PROC_I(inode)->op.proc_read(task, (char*)page);
580
581 if (length >= 0)
582 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
583 free_page(page);
584 out:
585 put_task_struct(task);
586 out_no_task:
587 return length;
588 }
589
590 static const struct file_operations proc_info_file_operations = {
591 .read = proc_info_read,
592 };
593
594 static int mem_open(struct inode* inode, struct file* file)
595 {
596 file->private_data = (void*)((long)current->self_exec_id);
597 return 0;
598 }
599
600 static ssize_t mem_read(struct file * file, char __user * buf,
601 size_t count, loff_t *ppos)
602 {
603 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
604 char *page;
605 unsigned long src = *ppos;
606 int ret = -ESRCH;
607 struct mm_struct *mm;
608
609 if (!task)
610 goto out_no_task;
611
612 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
613 goto out;
614
615 ret = -ENOMEM;
616 page = (char *)__get_free_page(GFP_TEMPORARY);
617 if (!page)
618 goto out;
619
620 ret = 0;
621
622 mm = get_task_mm(task);
623 if (!mm)
624 goto out_free;
625
626 ret = -EIO;
627
628 if (file->private_data != (void*)((long)current->self_exec_id))
629 goto out_put;
630
631 ret = 0;
632
633 while (count > 0) {
634 int this_len, retval;
635
636 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
637 retval = access_process_vm(task, src, page, this_len, 0);
638 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
639 if (!ret)
640 ret = -EIO;
641 break;
642 }
643
644 if (copy_to_user(buf, page, retval)) {
645 ret = -EFAULT;
646 break;
647 }
648
649 ret += retval;
650 src += retval;
651 buf += retval;
652 count -= retval;
653 }
654 *ppos = src;
655
656 out_put:
657 mmput(mm);
658 out_free:
659 free_page((unsigned long) page);
660 out:
661 put_task_struct(task);
662 out_no_task:
663 return ret;
664 }
665
666 #define mem_write NULL
667
668 #ifndef mem_write
669 /* This is a security hazard */
670 static ssize_t mem_write(struct file * file, const char __user *buf,
671 size_t count, loff_t *ppos)
672 {
673 int copied;
674 char *page;
675 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
676 unsigned long dst = *ppos;
677
678 copied = -ESRCH;
679 if (!task)
680 goto out_no_task;
681
682 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
683 goto out;
684
685 copied = -ENOMEM;
686 page = (char *)__get_free_page(GFP_TEMPORARY);
687 if (!page)
688 goto out;
689
690 copied = 0;
691 while (count > 0) {
692 int this_len, retval;
693
694 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
695 if (copy_from_user(page, buf, this_len)) {
696 copied = -EFAULT;
697 break;
698 }
699 retval = access_process_vm(task, dst, page, this_len, 1);
700 if (!retval) {
701 if (!copied)
702 copied = -EIO;
703 break;
704 }
705 copied += retval;
706 buf += retval;
707 dst += retval;
708 count -= retval;
709 }
710 *ppos = dst;
711 free_page((unsigned long) page);
712 out:
713 put_task_struct(task);
714 out_no_task:
715 return copied;
716 }
717 #endif
718
719 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
720 {
721 switch (orig) {
722 case 0:
723 file->f_pos = offset;
724 break;
725 case 1:
726 file->f_pos += offset;
727 break;
728 default:
729 return -EINVAL;
730 }
731 force_successful_syscall_return();
732 return file->f_pos;
733 }
734
735 static const struct file_operations proc_mem_operations = {
736 .llseek = mem_lseek,
737 .read = mem_read,
738 .write = mem_write,
739 .open = mem_open,
740 };
741
742 static ssize_t environ_read(struct file *file, char __user *buf,
743 size_t count, loff_t *ppos)
744 {
745 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
746 char *page;
747 unsigned long src = *ppos;
748 int ret = -ESRCH;
749 struct mm_struct *mm;
750
751 if (!task)
752 goto out_no_task;
753
754 if (!ptrace_may_attach(task))
755 goto out;
756
757 ret = -ENOMEM;
758 page = (char *)__get_free_page(GFP_TEMPORARY);
759 if (!page)
760 goto out;
761
762 ret = 0;
763
764 mm = get_task_mm(task);
765 if (!mm)
766 goto out_free;
767
768 while (count > 0) {
769 int this_len, retval, max_len;
770
771 this_len = mm->env_end - (mm->env_start + src);
772
773 if (this_len <= 0)
774 break;
775
776 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
777 this_len = (this_len > max_len) ? max_len : this_len;
778
779 retval = access_process_vm(task, (mm->env_start + src),
780 page, this_len, 0);
781
782 if (retval <= 0) {
783 ret = retval;
784 break;
785 }
786
787 if (copy_to_user(buf, page, retval)) {
788 ret = -EFAULT;
789 break;
790 }
791
792 ret += retval;
793 src += retval;
794 buf += retval;
795 count -= retval;
796 }
797 *ppos = src;
798
799 mmput(mm);
800 out_free:
801 free_page((unsigned long) page);
802 out:
803 put_task_struct(task);
804 out_no_task:
805 return ret;
806 }
807
808 static const struct file_operations proc_environ_operations = {
809 .read = environ_read,
810 };
811
812 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
813 size_t count, loff_t *ppos)
814 {
815 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
816 char buffer[PROC_NUMBUF];
817 size_t len;
818 int oom_adjust;
819
820 if (!task)
821 return -ESRCH;
822 oom_adjust = task->oomkilladj;
823 put_task_struct(task);
824
825 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
826
827 return simple_read_from_buffer(buf, count, ppos, buffer, len);
828 }
829
830 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
831 size_t count, loff_t *ppos)
832 {
833 struct task_struct *task;
834 char buffer[PROC_NUMBUF], *end;
835 int oom_adjust;
836
837 memset(buffer, 0, sizeof(buffer));
838 if (count > sizeof(buffer) - 1)
839 count = sizeof(buffer) - 1;
840 if (copy_from_user(buffer, buf, count))
841 return -EFAULT;
842 oom_adjust = simple_strtol(buffer, &end, 0);
843 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
844 oom_adjust != OOM_DISABLE)
845 return -EINVAL;
846 if (*end == '\n')
847 end++;
848 task = get_proc_task(file->f_path.dentry->d_inode);
849 if (!task)
850 return -ESRCH;
851 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
852 put_task_struct(task);
853 return -EACCES;
854 }
855 task->oomkilladj = oom_adjust;
856 put_task_struct(task);
857 if (end - buffer == 0)
858 return -EIO;
859 return end - buffer;
860 }
861
862 static const struct file_operations proc_oom_adjust_operations = {
863 .read = oom_adjust_read,
864 .write = oom_adjust_write,
865 };
866
867 #ifdef CONFIG_MMU
868 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
869 size_t count, loff_t *ppos)
870 {
871 struct task_struct *task;
872 char buffer[PROC_NUMBUF], *end;
873 struct mm_struct *mm;
874
875 memset(buffer, 0, sizeof(buffer));
876 if (count > sizeof(buffer) - 1)
877 count = sizeof(buffer) - 1;
878 if (copy_from_user(buffer, buf, count))
879 return -EFAULT;
880 if (!simple_strtol(buffer, &end, 0))
881 return -EINVAL;
882 if (*end == '\n')
883 end++;
884 task = get_proc_task(file->f_path.dentry->d_inode);
885 if (!task)
886 return -ESRCH;
887 mm = get_task_mm(task);
888 if (mm) {
889 clear_refs_smap(mm);
890 mmput(mm);
891 }
892 put_task_struct(task);
893 if (end - buffer == 0)
894 return -EIO;
895 return end - buffer;
896 }
897
898 static struct file_operations proc_clear_refs_operations = {
899 .write = clear_refs_write,
900 };
901 #endif
902
903 #ifdef CONFIG_AUDITSYSCALL
904 #define TMPBUFLEN 21
905 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
906 size_t count, loff_t *ppos)
907 {
908 struct inode * inode = file->f_path.dentry->d_inode;
909 struct task_struct *task = get_proc_task(inode);
910 ssize_t length;
911 char tmpbuf[TMPBUFLEN];
912
913 if (!task)
914 return -ESRCH;
915 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
916 audit_get_loginuid(task->audit_context));
917 put_task_struct(task);
918 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
919 }
920
921 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
922 size_t count, loff_t *ppos)
923 {
924 struct inode * inode = file->f_path.dentry->d_inode;
925 char *page, *tmp;
926 ssize_t length;
927 uid_t loginuid;
928
929 if (!capable(CAP_AUDIT_CONTROL))
930 return -EPERM;
931
932 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
933 return -EPERM;
934
935 if (count >= PAGE_SIZE)
936 count = PAGE_SIZE - 1;
937
938 if (*ppos != 0) {
939 /* No partial writes. */
940 return -EINVAL;
941 }
942 page = (char*)__get_free_page(GFP_TEMPORARY);
943 if (!page)
944 return -ENOMEM;
945 length = -EFAULT;
946 if (copy_from_user(page, buf, count))
947 goto out_free_page;
948
949 page[count] = '\0';
950 loginuid = simple_strtoul(page, &tmp, 10);
951 if (tmp == page) {
952 length = -EINVAL;
953 goto out_free_page;
954
955 }
956 length = audit_set_loginuid(current, loginuid);
957 if (likely(length == 0))
958 length = count;
959
960 out_free_page:
961 free_page((unsigned long) page);
962 return length;
963 }
964
965 static const struct file_operations proc_loginuid_operations = {
966 .read = proc_loginuid_read,
967 .write = proc_loginuid_write,
968 };
969 #endif
970
971 #ifdef CONFIG_FAULT_INJECTION
972 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
973 size_t count, loff_t *ppos)
974 {
975 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
976 char buffer[PROC_NUMBUF];
977 size_t len;
978 int make_it_fail;
979
980 if (!task)
981 return -ESRCH;
982 make_it_fail = task->make_it_fail;
983 put_task_struct(task);
984
985 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
986
987 return simple_read_from_buffer(buf, count, ppos, buffer, len);
988 }
989
990 static ssize_t proc_fault_inject_write(struct file * file,
991 const char __user * buf, size_t count, loff_t *ppos)
992 {
993 struct task_struct *task;
994 char buffer[PROC_NUMBUF], *end;
995 int make_it_fail;
996
997 if (!capable(CAP_SYS_RESOURCE))
998 return -EPERM;
999 memset(buffer, 0, sizeof(buffer));
1000 if (count > sizeof(buffer) - 1)
1001 count = sizeof(buffer) - 1;
1002 if (copy_from_user(buffer, buf, count))
1003 return -EFAULT;
1004 make_it_fail = simple_strtol(buffer, &end, 0);
1005 if (*end == '\n')
1006 end++;
1007 task = get_proc_task(file->f_dentry->d_inode);
1008 if (!task)
1009 return -ESRCH;
1010 task->make_it_fail = make_it_fail;
1011 put_task_struct(task);
1012 if (end - buffer == 0)
1013 return -EIO;
1014 return end - buffer;
1015 }
1016
1017 static const struct file_operations proc_fault_inject_operations = {
1018 .read = proc_fault_inject_read,
1019 .write = proc_fault_inject_write,
1020 };
1021 #endif
1022
1023 #ifdef CONFIG_SCHED_DEBUG
1024 /*
1025 * Print out various scheduling related per-task fields:
1026 */
1027 static int sched_show(struct seq_file *m, void *v)
1028 {
1029 struct inode *inode = m->private;
1030 struct task_struct *p;
1031
1032 WARN_ON(!inode);
1033
1034 p = get_proc_task(inode);
1035 if (!p)
1036 return -ESRCH;
1037 proc_sched_show_task(p, m);
1038
1039 put_task_struct(p);
1040
1041 return 0;
1042 }
1043
1044 static ssize_t
1045 sched_write(struct file *file, const char __user *buf,
1046 size_t count, loff_t *offset)
1047 {
1048 struct inode *inode = file->f_path.dentry->d_inode;
1049 struct task_struct *p;
1050
1051 WARN_ON(!inode);
1052
1053 p = get_proc_task(inode);
1054 if (!p)
1055 return -ESRCH;
1056 proc_sched_set_task(p);
1057
1058 put_task_struct(p);
1059
1060 return count;
1061 }
1062
1063 static int sched_open(struct inode *inode, struct file *filp)
1064 {
1065 int ret;
1066
1067 ret = single_open(filp, sched_show, NULL);
1068 if (!ret) {
1069 struct seq_file *m = filp->private_data;
1070
1071 m->private = inode;
1072 }
1073 return ret;
1074 }
1075
1076 static const struct file_operations proc_pid_sched_operations = {
1077 .open = sched_open,
1078 .read = seq_read,
1079 .write = sched_write,
1080 .llseek = seq_lseek,
1081 .release = single_release,
1082 };
1083
1084 #endif
1085
1086 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1087 {
1088 struct inode *inode = dentry->d_inode;
1089 int error = -EACCES;
1090
1091 /* We don't need a base pointer in the /proc filesystem */
1092 path_release(nd);
1093
1094 /* Are we allowed to snoop on the tasks file descriptors? */
1095 if (!proc_fd_access_allowed(inode))
1096 goto out;
1097
1098 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1099 nd->last_type = LAST_BIND;
1100 out:
1101 return ERR_PTR(error);
1102 }
1103
1104 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1105 char __user *buffer, int buflen)
1106 {
1107 struct inode * inode;
1108 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1109 char *path;
1110 int len;
1111
1112 if (!tmp)
1113 return -ENOMEM;
1114
1115 inode = dentry->d_inode;
1116 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1117 len = PTR_ERR(path);
1118 if (IS_ERR(path))
1119 goto out;
1120 len = tmp + PAGE_SIZE - 1 - path;
1121
1122 if (len > buflen)
1123 len = buflen;
1124 if (copy_to_user(buffer, path, len))
1125 len = -EFAULT;
1126 out:
1127 free_page((unsigned long)tmp);
1128 return len;
1129 }
1130
1131 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1132 {
1133 int error = -EACCES;
1134 struct inode *inode = dentry->d_inode;
1135 struct dentry *de;
1136 struct vfsmount *mnt = NULL;
1137
1138 /* Are we allowed to snoop on the tasks file descriptors? */
1139 if (!proc_fd_access_allowed(inode))
1140 goto out;
1141
1142 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1143 if (error)
1144 goto out;
1145
1146 error = do_proc_readlink(de, mnt, buffer, buflen);
1147 dput(de);
1148 mntput(mnt);
1149 out:
1150 return error;
1151 }
1152
1153 static const struct inode_operations proc_pid_link_inode_operations = {
1154 .readlink = proc_pid_readlink,
1155 .follow_link = proc_pid_follow_link,
1156 .setattr = proc_setattr,
1157 };
1158
1159
1160 /* building an inode */
1161
1162 static int task_dumpable(struct task_struct *task)
1163 {
1164 int dumpable = 0;
1165 struct mm_struct *mm;
1166
1167 task_lock(task);
1168 mm = task->mm;
1169 if (mm)
1170 dumpable = get_dumpable(mm);
1171 task_unlock(task);
1172 if(dumpable == 1)
1173 return 1;
1174 return 0;
1175 }
1176
1177
1178 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1179 {
1180 struct inode * inode;
1181 struct proc_inode *ei;
1182
1183 /* We need a new inode */
1184
1185 inode = new_inode(sb);
1186 if (!inode)
1187 goto out;
1188
1189 /* Common stuff */
1190 ei = PROC_I(inode);
1191 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1192 inode->i_op = &proc_def_inode_operations;
1193
1194 /*
1195 * grab the reference to task.
1196 */
1197 ei->pid = get_task_pid(task, PIDTYPE_PID);
1198 if (!ei->pid)
1199 goto out_unlock;
1200
1201 inode->i_uid = 0;
1202 inode->i_gid = 0;
1203 if (task_dumpable(task)) {
1204 inode->i_uid = task->euid;
1205 inode->i_gid = task->egid;
1206 }
1207 security_task_to_inode(task, inode);
1208
1209 out:
1210 return inode;
1211
1212 out_unlock:
1213 iput(inode);
1214 return NULL;
1215 }
1216
1217 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1218 {
1219 struct inode *inode = dentry->d_inode;
1220 struct task_struct *task;
1221 generic_fillattr(inode, stat);
1222
1223 rcu_read_lock();
1224 stat->uid = 0;
1225 stat->gid = 0;
1226 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1227 if (task) {
1228 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1229 task_dumpable(task)) {
1230 stat->uid = task->euid;
1231 stat->gid = task->egid;
1232 }
1233 }
1234 rcu_read_unlock();
1235 return 0;
1236 }
1237
1238 /* dentry stuff */
1239
1240 /*
1241 * Exceptional case: normally we are not allowed to unhash a busy
1242 * directory. In this case, however, we can do it - no aliasing problems
1243 * due to the way we treat inodes.
1244 *
1245 * Rewrite the inode's ownerships here because the owning task may have
1246 * performed a setuid(), etc.
1247 *
1248 * Before the /proc/pid/status file was created the only way to read
1249 * the effective uid of a /process was to stat /proc/pid. Reading
1250 * /proc/pid/status is slow enough that procps and other packages
1251 * kept stating /proc/pid. To keep the rules in /proc simple I have
1252 * made this apply to all per process world readable and executable
1253 * directories.
1254 */
1255 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1256 {
1257 struct inode *inode = dentry->d_inode;
1258 struct task_struct *task = get_proc_task(inode);
1259 if (task) {
1260 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1261 task_dumpable(task)) {
1262 inode->i_uid = task->euid;
1263 inode->i_gid = task->egid;
1264 } else {
1265 inode->i_uid = 0;
1266 inode->i_gid = 0;
1267 }
1268 inode->i_mode &= ~(S_ISUID | S_ISGID);
1269 security_task_to_inode(task, inode);
1270 put_task_struct(task);
1271 return 1;
1272 }
1273 d_drop(dentry);
1274 return 0;
1275 }
1276
1277 static int pid_delete_dentry(struct dentry * dentry)
1278 {
1279 /* Is the task we represent dead?
1280 * If so, then don't put the dentry on the lru list,
1281 * kill it immediately.
1282 */
1283 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1284 }
1285
1286 static struct dentry_operations pid_dentry_operations =
1287 {
1288 .d_revalidate = pid_revalidate,
1289 .d_delete = pid_delete_dentry,
1290 };
1291
1292 /* Lookups */
1293
1294 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1295 struct task_struct *, const void *);
1296
1297 /*
1298 * Fill a directory entry.
1299 *
1300 * If possible create the dcache entry and derive our inode number and
1301 * file type from dcache entry.
1302 *
1303 * Since all of the proc inode numbers are dynamically generated, the inode
1304 * numbers do not exist until the inode is cache. This means creating the
1305 * the dcache entry in readdir is necessary to keep the inode numbers
1306 * reported by readdir in sync with the inode numbers reported
1307 * by stat.
1308 */
1309 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1310 char *name, int len,
1311 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1312 {
1313 struct dentry *child, *dir = filp->f_path.dentry;
1314 struct inode *inode;
1315 struct qstr qname;
1316 ino_t ino = 0;
1317 unsigned type = DT_UNKNOWN;
1318
1319 qname.name = name;
1320 qname.len = len;
1321 qname.hash = full_name_hash(name, len);
1322
1323 child = d_lookup(dir, &qname);
1324 if (!child) {
1325 struct dentry *new;
1326 new = d_alloc(dir, &qname);
1327 if (new) {
1328 child = instantiate(dir->d_inode, new, task, ptr);
1329 if (child)
1330 dput(new);
1331 else
1332 child = new;
1333 }
1334 }
1335 if (!child || IS_ERR(child) || !child->d_inode)
1336 goto end_instantiate;
1337 inode = child->d_inode;
1338 if (inode) {
1339 ino = inode->i_ino;
1340 type = inode->i_mode >> 12;
1341 }
1342 dput(child);
1343 end_instantiate:
1344 if (!ino)
1345 ino = find_inode_number(dir, &qname);
1346 if (!ino)
1347 ino = 1;
1348 return filldir(dirent, name, len, filp->f_pos, ino, type);
1349 }
1350
1351 static unsigned name_to_int(struct dentry *dentry)
1352 {
1353 const char *name = dentry->d_name.name;
1354 int len = dentry->d_name.len;
1355 unsigned n = 0;
1356
1357 if (len > 1 && *name == '0')
1358 goto out;
1359 while (len-- > 0) {
1360 unsigned c = *name++ - '0';
1361 if (c > 9)
1362 goto out;
1363 if (n >= (~0U-9)/10)
1364 goto out;
1365 n *= 10;
1366 n += c;
1367 }
1368 return n;
1369 out:
1370 return ~0U;
1371 }
1372
1373 #define PROC_FDINFO_MAX 64
1374
1375 static int proc_fd_info(struct inode *inode, struct dentry **dentry,
1376 struct vfsmount **mnt, char *info)
1377 {
1378 struct task_struct *task = get_proc_task(inode);
1379 struct files_struct *files = NULL;
1380 struct file *file;
1381 int fd = proc_fd(inode);
1382
1383 if (task) {
1384 files = get_files_struct(task);
1385 put_task_struct(task);
1386 }
1387 if (files) {
1388 /*
1389 * We are not taking a ref to the file structure, so we must
1390 * hold ->file_lock.
1391 */
1392 spin_lock(&files->file_lock);
1393 file = fcheck_files(files, fd);
1394 if (file) {
1395 if (mnt)
1396 *mnt = mntget(file->f_path.mnt);
1397 if (dentry)
1398 *dentry = dget(file->f_path.dentry);
1399 if (info)
1400 snprintf(info, PROC_FDINFO_MAX,
1401 "pos:\t%lli\n"
1402 "flags:\t0%o\n",
1403 (long long) file->f_pos,
1404 file->f_flags);
1405 spin_unlock(&files->file_lock);
1406 put_files_struct(files);
1407 return 0;
1408 }
1409 spin_unlock(&files->file_lock);
1410 put_files_struct(files);
1411 }
1412 return -ENOENT;
1413 }
1414
1415 static int proc_fd_link(struct inode *inode, struct dentry **dentry,
1416 struct vfsmount **mnt)
1417 {
1418 return proc_fd_info(inode, dentry, mnt, NULL);
1419 }
1420
1421 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1422 {
1423 struct inode *inode = dentry->d_inode;
1424 struct task_struct *task = get_proc_task(inode);
1425 int fd = proc_fd(inode);
1426 struct files_struct *files;
1427
1428 if (task) {
1429 files = get_files_struct(task);
1430 if (files) {
1431 rcu_read_lock();
1432 if (fcheck_files(files, fd)) {
1433 rcu_read_unlock();
1434 put_files_struct(files);
1435 if (task_dumpable(task)) {
1436 inode->i_uid = task->euid;
1437 inode->i_gid = task->egid;
1438 } else {
1439 inode->i_uid = 0;
1440 inode->i_gid = 0;
1441 }
1442 inode->i_mode &= ~(S_ISUID | S_ISGID);
1443 security_task_to_inode(task, inode);
1444 put_task_struct(task);
1445 return 1;
1446 }
1447 rcu_read_unlock();
1448 put_files_struct(files);
1449 }
1450 put_task_struct(task);
1451 }
1452 d_drop(dentry);
1453 return 0;
1454 }
1455
1456 static struct dentry_operations tid_fd_dentry_operations =
1457 {
1458 .d_revalidate = tid_fd_revalidate,
1459 .d_delete = pid_delete_dentry,
1460 };
1461
1462 static struct dentry *proc_fd_instantiate(struct inode *dir,
1463 struct dentry *dentry, struct task_struct *task, const void *ptr)
1464 {
1465 unsigned fd = *(const unsigned *)ptr;
1466 struct file *file;
1467 struct files_struct *files;
1468 struct inode *inode;
1469 struct proc_inode *ei;
1470 struct dentry *error = ERR_PTR(-ENOENT);
1471
1472 inode = proc_pid_make_inode(dir->i_sb, task);
1473 if (!inode)
1474 goto out;
1475 ei = PROC_I(inode);
1476 ei->fd = fd;
1477 files = get_files_struct(task);
1478 if (!files)
1479 goto out_iput;
1480 inode->i_mode = S_IFLNK;
1481
1482 /*
1483 * We are not taking a ref to the file structure, so we must
1484 * hold ->file_lock.
1485 */
1486 spin_lock(&files->file_lock);
1487 file = fcheck_files(files, fd);
1488 if (!file)
1489 goto out_unlock;
1490 if (file->f_mode & 1)
1491 inode->i_mode |= S_IRUSR | S_IXUSR;
1492 if (file->f_mode & 2)
1493 inode->i_mode |= S_IWUSR | S_IXUSR;
1494 spin_unlock(&files->file_lock);
1495 put_files_struct(files);
1496
1497 inode->i_op = &proc_pid_link_inode_operations;
1498 inode->i_size = 64;
1499 ei->op.proc_get_link = proc_fd_link;
1500 dentry->d_op = &tid_fd_dentry_operations;
1501 d_add(dentry, inode);
1502 /* Close the race of the process dying before we return the dentry */
1503 if (tid_fd_revalidate(dentry, NULL))
1504 error = NULL;
1505
1506 out:
1507 return error;
1508 out_unlock:
1509 spin_unlock(&files->file_lock);
1510 put_files_struct(files);
1511 out_iput:
1512 iput(inode);
1513 goto out;
1514 }
1515
1516 static struct dentry *proc_lookupfd_common(struct inode *dir,
1517 struct dentry *dentry,
1518 instantiate_t instantiate)
1519 {
1520 struct task_struct *task = get_proc_task(dir);
1521 unsigned fd = name_to_int(dentry);
1522 struct dentry *result = ERR_PTR(-ENOENT);
1523
1524 if (!task)
1525 goto out_no_task;
1526 if (fd == ~0U)
1527 goto out;
1528
1529 result = instantiate(dir, dentry, task, &fd);
1530 out:
1531 put_task_struct(task);
1532 out_no_task:
1533 return result;
1534 }
1535
1536 static int proc_readfd_common(struct file * filp, void * dirent,
1537 filldir_t filldir, instantiate_t instantiate)
1538 {
1539 struct dentry *dentry = filp->f_path.dentry;
1540 struct inode *inode = dentry->d_inode;
1541 struct task_struct *p = get_proc_task(inode);
1542 unsigned int fd, ino;
1543 int retval;
1544 struct files_struct * files;
1545 struct fdtable *fdt;
1546
1547 retval = -ENOENT;
1548 if (!p)
1549 goto out_no_task;
1550 retval = 0;
1551
1552 fd = filp->f_pos;
1553 switch (fd) {
1554 case 0:
1555 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1556 goto out;
1557 filp->f_pos++;
1558 case 1:
1559 ino = parent_ino(dentry);
1560 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1561 goto out;
1562 filp->f_pos++;
1563 default:
1564 files = get_files_struct(p);
1565 if (!files)
1566 goto out;
1567 rcu_read_lock();
1568 fdt = files_fdtable(files);
1569 for (fd = filp->f_pos-2;
1570 fd < fdt->max_fds;
1571 fd++, filp->f_pos++) {
1572 char name[PROC_NUMBUF];
1573 int len;
1574
1575 if (!fcheck_files(files, fd))
1576 continue;
1577 rcu_read_unlock();
1578
1579 len = snprintf(name, sizeof(name), "%d", fd);
1580 if (proc_fill_cache(filp, dirent, filldir,
1581 name, len, instantiate,
1582 p, &fd) < 0) {
1583 rcu_read_lock();
1584 break;
1585 }
1586 rcu_read_lock();
1587 }
1588 rcu_read_unlock();
1589 put_files_struct(files);
1590 }
1591 out:
1592 put_task_struct(p);
1593 out_no_task:
1594 return retval;
1595 }
1596
1597 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1598 struct nameidata *nd)
1599 {
1600 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1601 }
1602
1603 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1604 {
1605 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1606 }
1607
1608 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1609 size_t len, loff_t *ppos)
1610 {
1611 char tmp[PROC_FDINFO_MAX];
1612 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
1613 if (!err)
1614 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1615 return err;
1616 }
1617
1618 static const struct file_operations proc_fdinfo_file_operations = {
1619 .open = nonseekable_open,
1620 .read = proc_fdinfo_read,
1621 };
1622
1623 static const struct file_operations proc_fd_operations = {
1624 .read = generic_read_dir,
1625 .readdir = proc_readfd,
1626 };
1627
1628 /*
1629 * /proc/pid/fd needs a special permission handler so that a process can still
1630 * access /proc/self/fd after it has executed a setuid().
1631 */
1632 static int proc_fd_permission(struct inode *inode, int mask,
1633 struct nameidata *nd)
1634 {
1635 int rv;
1636
1637 rv = generic_permission(inode, mask, NULL);
1638 if (rv == 0)
1639 return 0;
1640 if (task_pid(current) == proc_pid(inode))
1641 rv = 0;
1642 return rv;
1643 }
1644
1645 /*
1646 * proc directories can do almost nothing..
1647 */
1648 static const struct inode_operations proc_fd_inode_operations = {
1649 .lookup = proc_lookupfd,
1650 .permission = proc_fd_permission,
1651 .setattr = proc_setattr,
1652 };
1653
1654 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1655 struct dentry *dentry, struct task_struct *task, const void *ptr)
1656 {
1657 unsigned fd = *(unsigned *)ptr;
1658 struct inode *inode;
1659 struct proc_inode *ei;
1660 struct dentry *error = ERR_PTR(-ENOENT);
1661
1662 inode = proc_pid_make_inode(dir->i_sb, task);
1663 if (!inode)
1664 goto out;
1665 ei = PROC_I(inode);
1666 ei->fd = fd;
1667 inode->i_mode = S_IFREG | S_IRUSR;
1668 inode->i_fop = &proc_fdinfo_file_operations;
1669 dentry->d_op = &tid_fd_dentry_operations;
1670 d_add(dentry, inode);
1671 /* Close the race of the process dying before we return the dentry */
1672 if (tid_fd_revalidate(dentry, NULL))
1673 error = NULL;
1674
1675 out:
1676 return error;
1677 }
1678
1679 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1680 struct dentry *dentry,
1681 struct nameidata *nd)
1682 {
1683 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1684 }
1685
1686 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1687 {
1688 return proc_readfd_common(filp, dirent, filldir,
1689 proc_fdinfo_instantiate);
1690 }
1691
1692 static const struct file_operations proc_fdinfo_operations = {
1693 .read = generic_read_dir,
1694 .readdir = proc_readfdinfo,
1695 };
1696
1697 /*
1698 * proc directories can do almost nothing..
1699 */
1700 static const struct inode_operations proc_fdinfo_inode_operations = {
1701 .lookup = proc_lookupfdinfo,
1702 .setattr = proc_setattr,
1703 };
1704
1705
1706 static struct dentry *proc_pident_instantiate(struct inode *dir,
1707 struct dentry *dentry, struct task_struct *task, const void *ptr)
1708 {
1709 const struct pid_entry *p = ptr;
1710 struct inode *inode;
1711 struct proc_inode *ei;
1712 struct dentry *error = ERR_PTR(-EINVAL);
1713
1714 inode = proc_pid_make_inode(dir->i_sb, task);
1715 if (!inode)
1716 goto out;
1717
1718 ei = PROC_I(inode);
1719 inode->i_mode = p->mode;
1720 if (S_ISDIR(inode->i_mode))
1721 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1722 if (p->iop)
1723 inode->i_op = p->iop;
1724 if (p->fop)
1725 inode->i_fop = p->fop;
1726 ei->op = p->op;
1727 dentry->d_op = &pid_dentry_operations;
1728 d_add(dentry, inode);
1729 /* Close the race of the process dying before we return the dentry */
1730 if (pid_revalidate(dentry, NULL))
1731 error = NULL;
1732 out:
1733 return error;
1734 }
1735
1736 static struct dentry *proc_pident_lookup(struct inode *dir,
1737 struct dentry *dentry,
1738 const struct pid_entry *ents,
1739 unsigned int nents)
1740 {
1741 struct inode *inode;
1742 struct dentry *error;
1743 struct task_struct *task = get_proc_task(dir);
1744 const struct pid_entry *p, *last;
1745
1746 error = ERR_PTR(-ENOENT);
1747 inode = NULL;
1748
1749 if (!task)
1750 goto out_no_task;
1751
1752 /*
1753 * Yes, it does not scale. And it should not. Don't add
1754 * new entries into /proc/<tgid>/ without very good reasons.
1755 */
1756 last = &ents[nents - 1];
1757 for (p = ents; p <= last; p++) {
1758 if (p->len != dentry->d_name.len)
1759 continue;
1760 if (!memcmp(dentry->d_name.name, p->name, p->len))
1761 break;
1762 }
1763 if (p > last)
1764 goto out;
1765
1766 error = proc_pident_instantiate(dir, dentry, task, p);
1767 out:
1768 put_task_struct(task);
1769 out_no_task:
1770 return error;
1771 }
1772
1773 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1774 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1775 {
1776 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1777 proc_pident_instantiate, task, p);
1778 }
1779
1780 static int proc_pident_readdir(struct file *filp,
1781 void *dirent, filldir_t filldir,
1782 const struct pid_entry *ents, unsigned int nents)
1783 {
1784 int i;
1785 struct dentry *dentry = filp->f_path.dentry;
1786 struct inode *inode = dentry->d_inode;
1787 struct task_struct *task = get_proc_task(inode);
1788 const struct pid_entry *p, *last;
1789 ino_t ino;
1790 int ret;
1791
1792 ret = -ENOENT;
1793 if (!task)
1794 goto out_no_task;
1795
1796 ret = 0;
1797 i = filp->f_pos;
1798 switch (i) {
1799 case 0:
1800 ino = inode->i_ino;
1801 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1802 goto out;
1803 i++;
1804 filp->f_pos++;
1805 /* fall through */
1806 case 1:
1807 ino = parent_ino(dentry);
1808 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1809 goto out;
1810 i++;
1811 filp->f_pos++;
1812 /* fall through */
1813 default:
1814 i -= 2;
1815 if (i >= nents) {
1816 ret = 1;
1817 goto out;
1818 }
1819 p = ents + i;
1820 last = &ents[nents - 1];
1821 while (p <= last) {
1822 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1823 goto out;
1824 filp->f_pos++;
1825 p++;
1826 }
1827 }
1828
1829 ret = 1;
1830 out:
1831 put_task_struct(task);
1832 out_no_task:
1833 return ret;
1834 }
1835
1836 #ifdef CONFIG_SECURITY
1837 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1838 size_t count, loff_t *ppos)
1839 {
1840 struct inode * inode = file->f_path.dentry->d_inode;
1841 char *p = NULL;
1842 ssize_t length;
1843 struct task_struct *task = get_proc_task(inode);
1844
1845 if (!task)
1846 return -ESRCH;
1847
1848 length = security_getprocattr(task,
1849 (char*)file->f_path.dentry->d_name.name,
1850 &p);
1851 put_task_struct(task);
1852 if (length > 0)
1853 length = simple_read_from_buffer(buf, count, ppos, p, length);
1854 kfree(p);
1855 return length;
1856 }
1857
1858 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1859 size_t count, loff_t *ppos)
1860 {
1861 struct inode * inode = file->f_path.dentry->d_inode;
1862 char *page;
1863 ssize_t length;
1864 struct task_struct *task = get_proc_task(inode);
1865
1866 length = -ESRCH;
1867 if (!task)
1868 goto out_no_task;
1869 if (count > PAGE_SIZE)
1870 count = PAGE_SIZE;
1871
1872 /* No partial writes. */
1873 length = -EINVAL;
1874 if (*ppos != 0)
1875 goto out;
1876
1877 length = -ENOMEM;
1878 page = (char*)__get_free_page(GFP_TEMPORARY);
1879 if (!page)
1880 goto out;
1881
1882 length = -EFAULT;
1883 if (copy_from_user(page, buf, count))
1884 goto out_free;
1885
1886 length = security_setprocattr(task,
1887 (char*)file->f_path.dentry->d_name.name,
1888 (void*)page, count);
1889 out_free:
1890 free_page((unsigned long) page);
1891 out:
1892 put_task_struct(task);
1893 out_no_task:
1894 return length;
1895 }
1896
1897 static const struct file_operations proc_pid_attr_operations = {
1898 .read = proc_pid_attr_read,
1899 .write = proc_pid_attr_write,
1900 };
1901
1902 static const struct pid_entry attr_dir_stuff[] = {
1903 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1904 REG("prev", S_IRUGO, pid_attr),
1905 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1906 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1907 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1908 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1909 };
1910
1911 static int proc_attr_dir_readdir(struct file * filp,
1912 void * dirent, filldir_t filldir)
1913 {
1914 return proc_pident_readdir(filp,dirent,filldir,
1915 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1916 }
1917
1918 static const struct file_operations proc_attr_dir_operations = {
1919 .read = generic_read_dir,
1920 .readdir = proc_attr_dir_readdir,
1921 };
1922
1923 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
1924 struct dentry *dentry, struct nameidata *nd)
1925 {
1926 return proc_pident_lookup(dir, dentry,
1927 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
1928 }
1929
1930 static const struct inode_operations proc_attr_dir_inode_operations = {
1931 .lookup = proc_attr_dir_lookup,
1932 .getattr = pid_getattr,
1933 .setattr = proc_setattr,
1934 };
1935
1936 #endif
1937
1938 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1939 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
1940 size_t count, loff_t *ppos)
1941 {
1942 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1943 struct mm_struct *mm;
1944 char buffer[PROC_NUMBUF];
1945 size_t len;
1946 int ret;
1947
1948 if (!task)
1949 return -ESRCH;
1950
1951 ret = 0;
1952 mm = get_task_mm(task);
1953 if (mm) {
1954 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
1955 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
1956 MMF_DUMP_FILTER_SHIFT));
1957 mmput(mm);
1958 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
1959 }
1960
1961 put_task_struct(task);
1962
1963 return ret;
1964 }
1965
1966 static ssize_t proc_coredump_filter_write(struct file *file,
1967 const char __user *buf,
1968 size_t count,
1969 loff_t *ppos)
1970 {
1971 struct task_struct *task;
1972 struct mm_struct *mm;
1973 char buffer[PROC_NUMBUF], *end;
1974 unsigned int val;
1975 int ret;
1976 int i;
1977 unsigned long mask;
1978
1979 ret = -EFAULT;
1980 memset(buffer, 0, sizeof(buffer));
1981 if (count > sizeof(buffer) - 1)
1982 count = sizeof(buffer) - 1;
1983 if (copy_from_user(buffer, buf, count))
1984 goto out_no_task;
1985
1986 ret = -EINVAL;
1987 val = (unsigned int)simple_strtoul(buffer, &end, 0);
1988 if (*end == '\n')
1989 end++;
1990 if (end - buffer == 0)
1991 goto out_no_task;
1992
1993 ret = -ESRCH;
1994 task = get_proc_task(file->f_dentry->d_inode);
1995 if (!task)
1996 goto out_no_task;
1997
1998 ret = end - buffer;
1999 mm = get_task_mm(task);
2000 if (!mm)
2001 goto out_no_mm;
2002
2003 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2004 if (val & mask)
2005 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2006 else
2007 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2008 }
2009
2010 mmput(mm);
2011 out_no_mm:
2012 put_task_struct(task);
2013 out_no_task:
2014 return ret;
2015 }
2016
2017 static const struct file_operations proc_coredump_filter_operations = {
2018 .read = proc_coredump_filter_read,
2019 .write = proc_coredump_filter_write,
2020 };
2021 #endif
2022
2023 /*
2024 * /proc/self:
2025 */
2026 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2027 int buflen)
2028 {
2029 char tmp[PROC_NUMBUF];
2030 sprintf(tmp, "%d", task_tgid_vnr(current));
2031 return vfs_readlink(dentry,buffer,buflen,tmp);
2032 }
2033
2034 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2035 {
2036 char tmp[PROC_NUMBUF];
2037 sprintf(tmp, "%d", task_tgid_vnr(current));
2038 return ERR_PTR(vfs_follow_link(nd,tmp));
2039 }
2040
2041 static const struct inode_operations proc_self_inode_operations = {
2042 .readlink = proc_self_readlink,
2043 .follow_link = proc_self_follow_link,
2044 };
2045
2046 /*
2047 * proc base
2048 *
2049 * These are the directory entries in the root directory of /proc
2050 * that properly belong to the /proc filesystem, as they describe
2051 * describe something that is process related.
2052 */
2053 static const struct pid_entry proc_base_stuff[] = {
2054 NOD("self", S_IFLNK|S_IRWXUGO,
2055 &proc_self_inode_operations, NULL, {}),
2056 };
2057
2058 /*
2059 * Exceptional case: normally we are not allowed to unhash a busy
2060 * directory. In this case, however, we can do it - no aliasing problems
2061 * due to the way we treat inodes.
2062 */
2063 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2064 {
2065 struct inode *inode = dentry->d_inode;
2066 struct task_struct *task = get_proc_task(inode);
2067 if (task) {
2068 put_task_struct(task);
2069 return 1;
2070 }
2071 d_drop(dentry);
2072 return 0;
2073 }
2074
2075 static struct dentry_operations proc_base_dentry_operations =
2076 {
2077 .d_revalidate = proc_base_revalidate,
2078 .d_delete = pid_delete_dentry,
2079 };
2080
2081 static struct dentry *proc_base_instantiate(struct inode *dir,
2082 struct dentry *dentry, struct task_struct *task, const void *ptr)
2083 {
2084 const struct pid_entry *p = ptr;
2085 struct inode *inode;
2086 struct proc_inode *ei;
2087 struct dentry *error = ERR_PTR(-EINVAL);
2088
2089 /* Allocate the inode */
2090 error = ERR_PTR(-ENOMEM);
2091 inode = new_inode(dir->i_sb);
2092 if (!inode)
2093 goto out;
2094
2095 /* Initialize the inode */
2096 ei = PROC_I(inode);
2097 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2098
2099 /*
2100 * grab the reference to the task.
2101 */
2102 ei->pid = get_task_pid(task, PIDTYPE_PID);
2103 if (!ei->pid)
2104 goto out_iput;
2105
2106 inode->i_uid = 0;
2107 inode->i_gid = 0;
2108 inode->i_mode = p->mode;
2109 if (S_ISDIR(inode->i_mode))
2110 inode->i_nlink = 2;
2111 if (S_ISLNK(inode->i_mode))
2112 inode->i_size = 64;
2113 if (p->iop)
2114 inode->i_op = p->iop;
2115 if (p->fop)
2116 inode->i_fop = p->fop;
2117 ei->op = p->op;
2118 dentry->d_op = &proc_base_dentry_operations;
2119 d_add(dentry, inode);
2120 error = NULL;
2121 out:
2122 return error;
2123 out_iput:
2124 iput(inode);
2125 goto out;
2126 }
2127
2128 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2129 {
2130 struct dentry *error;
2131 struct task_struct *task = get_proc_task(dir);
2132 const struct pid_entry *p, *last;
2133
2134 error = ERR_PTR(-ENOENT);
2135
2136 if (!task)
2137 goto out_no_task;
2138
2139 /* Lookup the directory entry */
2140 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2141 for (p = proc_base_stuff; p <= last; p++) {
2142 if (p->len != dentry->d_name.len)
2143 continue;
2144 if (!memcmp(dentry->d_name.name, p->name, p->len))
2145 break;
2146 }
2147 if (p > last)
2148 goto out;
2149
2150 error = proc_base_instantiate(dir, dentry, task, p);
2151
2152 out:
2153 put_task_struct(task);
2154 out_no_task:
2155 return error;
2156 }
2157
2158 static int proc_base_fill_cache(struct file *filp, void *dirent,
2159 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2160 {
2161 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2162 proc_base_instantiate, task, p);
2163 }
2164
2165 #ifdef CONFIG_TASK_IO_ACCOUNTING
2166 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2167 {
2168 return sprintf(buffer,
2169 #ifdef CONFIG_TASK_XACCT
2170 "rchar: %llu\n"
2171 "wchar: %llu\n"
2172 "syscr: %llu\n"
2173 "syscw: %llu\n"
2174 #endif
2175 "read_bytes: %llu\n"
2176 "write_bytes: %llu\n"
2177 "cancelled_write_bytes: %llu\n",
2178 #ifdef CONFIG_TASK_XACCT
2179 (unsigned long long)task->rchar,
2180 (unsigned long long)task->wchar,
2181 (unsigned long long)task->syscr,
2182 (unsigned long long)task->syscw,
2183 #endif
2184 (unsigned long long)task->ioac.read_bytes,
2185 (unsigned long long)task->ioac.write_bytes,
2186 (unsigned long long)task->ioac.cancelled_write_bytes);
2187 }
2188 #endif
2189
2190 /*
2191 * Thread groups
2192 */
2193 static const struct file_operations proc_task_operations;
2194 static const struct inode_operations proc_task_inode_operations;
2195
2196 static const struct pid_entry tgid_base_stuff[] = {
2197 DIR("task", S_IRUGO|S_IXUGO, task),
2198 DIR("fd", S_IRUSR|S_IXUSR, fd),
2199 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2200 REG("environ", S_IRUSR, environ),
2201 INF("auxv", S_IRUSR, pid_auxv),
2202 INF("status", S_IRUGO, pid_status),
2203 INF("limits", S_IRUSR, pid_limits),
2204 #ifdef CONFIG_SCHED_DEBUG
2205 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2206 #endif
2207 INF("cmdline", S_IRUGO, pid_cmdline),
2208 INF("stat", S_IRUGO, tgid_stat),
2209 INF("statm", S_IRUGO, pid_statm),
2210 REG("maps", S_IRUGO, maps),
2211 #ifdef CONFIG_NUMA
2212 REG("numa_maps", S_IRUGO, numa_maps),
2213 #endif
2214 REG("mem", S_IRUSR|S_IWUSR, mem),
2215 LNK("cwd", cwd),
2216 LNK("root", root),
2217 LNK("exe", exe),
2218 REG("mounts", S_IRUGO, mounts),
2219 REG("mountstats", S_IRUSR, mountstats),
2220 #ifdef CONFIG_MMU
2221 REG("clear_refs", S_IWUSR, clear_refs),
2222 REG("smaps", S_IRUGO, smaps),
2223 #endif
2224 #ifdef CONFIG_SECURITY
2225 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2226 #endif
2227 #ifdef CONFIG_KALLSYMS
2228 INF("wchan", S_IRUGO, pid_wchan),
2229 #endif
2230 #ifdef CONFIG_SCHEDSTATS
2231 INF("schedstat", S_IRUGO, pid_schedstat),
2232 #endif
2233 #ifdef CONFIG_PROC_PID_CPUSET
2234 REG("cpuset", S_IRUGO, cpuset),
2235 #endif
2236 #ifdef CONFIG_CGROUPS
2237 REG("cgroup", S_IRUGO, cgroup),
2238 #endif
2239 INF("oom_score", S_IRUGO, oom_score),
2240 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2241 #ifdef CONFIG_AUDITSYSCALL
2242 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2243 #endif
2244 #ifdef CONFIG_FAULT_INJECTION
2245 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2246 #endif
2247 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2248 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2249 #endif
2250 #ifdef CONFIG_TASK_IO_ACCOUNTING
2251 INF("io", S_IRUGO, pid_io_accounting),
2252 #endif
2253 };
2254
2255 static int proc_tgid_base_readdir(struct file * filp,
2256 void * dirent, filldir_t filldir)
2257 {
2258 return proc_pident_readdir(filp,dirent,filldir,
2259 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2260 }
2261
2262 static const struct file_operations proc_tgid_base_operations = {
2263 .read = generic_read_dir,
2264 .readdir = proc_tgid_base_readdir,
2265 };
2266
2267 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2268 return proc_pident_lookup(dir, dentry,
2269 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2270 }
2271
2272 static const struct inode_operations proc_tgid_base_inode_operations = {
2273 .lookup = proc_tgid_base_lookup,
2274 .getattr = pid_getattr,
2275 .setattr = proc_setattr,
2276 };
2277
2278 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2279 {
2280 struct dentry *dentry, *leader, *dir;
2281 char buf[PROC_NUMBUF];
2282 struct qstr name;
2283
2284 name.name = buf;
2285 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2286 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2287 if (dentry) {
2288 shrink_dcache_parent(dentry);
2289 d_drop(dentry);
2290 dput(dentry);
2291 }
2292
2293 if (tgid == 0)
2294 goto out;
2295
2296 name.name = buf;
2297 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2298 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2299 if (!leader)
2300 goto out;
2301
2302 name.name = "task";
2303 name.len = strlen(name.name);
2304 dir = d_hash_and_lookup(leader, &name);
2305 if (!dir)
2306 goto out_put_leader;
2307
2308 name.name = buf;
2309 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2310 dentry = d_hash_and_lookup(dir, &name);
2311 if (dentry) {
2312 shrink_dcache_parent(dentry);
2313 d_drop(dentry);
2314 dput(dentry);
2315 }
2316
2317 dput(dir);
2318 out_put_leader:
2319 dput(leader);
2320 out:
2321 return;
2322 }
2323
2324 /**
2325 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2326 * @task: task that should be flushed.
2327 *
2328 * When flushing dentries from proc, one needs to flush them from global
2329 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2330 * in. This call is supposed to do all of this job.
2331 *
2332 * Looks in the dcache for
2333 * /proc/@pid
2334 * /proc/@tgid/task/@pid
2335 * if either directory is present flushes it and all of it'ts children
2336 * from the dcache.
2337 *
2338 * It is safe and reasonable to cache /proc entries for a task until
2339 * that task exits. After that they just clog up the dcache with
2340 * useless entries, possibly causing useful dcache entries to be
2341 * flushed instead. This routine is proved to flush those useless
2342 * dcache entries at process exit time.
2343 *
2344 * NOTE: This routine is just an optimization so it does not guarantee
2345 * that no dcache entries will exist at process exit time it
2346 * just makes it very unlikely that any will persist.
2347 */
2348
2349 void proc_flush_task(struct task_struct *task)
2350 {
2351 int i;
2352 struct pid *pid, *tgid = NULL;
2353 struct upid *upid;
2354
2355 pid = task_pid(task);
2356 if (thread_group_leader(task))
2357 tgid = task_tgid(task);
2358
2359 for (i = 0; i <= pid->level; i++) {
2360 upid = &pid->numbers[i];
2361 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2362 tgid ? tgid->numbers[i].nr : 0);
2363 }
2364
2365 upid = &pid->numbers[pid->level];
2366 if (upid->nr == 1)
2367 pid_ns_release_proc(upid->ns);
2368 }
2369
2370 static struct dentry *proc_pid_instantiate(struct inode *dir,
2371 struct dentry * dentry,
2372 struct task_struct *task, const void *ptr)
2373 {
2374 struct dentry *error = ERR_PTR(-ENOENT);
2375 struct inode *inode;
2376
2377 inode = proc_pid_make_inode(dir->i_sb, task);
2378 if (!inode)
2379 goto out;
2380
2381 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2382 inode->i_op = &proc_tgid_base_inode_operations;
2383 inode->i_fop = &proc_tgid_base_operations;
2384 inode->i_flags|=S_IMMUTABLE;
2385 inode->i_nlink = 5;
2386 #ifdef CONFIG_SECURITY
2387 inode->i_nlink += 1;
2388 #endif
2389
2390 dentry->d_op = &pid_dentry_operations;
2391
2392 d_add(dentry, inode);
2393 /* Close the race of the process dying before we return the dentry */
2394 if (pid_revalidate(dentry, NULL))
2395 error = NULL;
2396 out:
2397 return error;
2398 }
2399
2400 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2401 {
2402 struct dentry *result = ERR_PTR(-ENOENT);
2403 struct task_struct *task;
2404 unsigned tgid;
2405 struct pid_namespace *ns;
2406
2407 result = proc_base_lookup(dir, dentry);
2408 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2409 goto out;
2410
2411 tgid = name_to_int(dentry);
2412 if (tgid == ~0U)
2413 goto out;
2414
2415 ns = dentry->d_sb->s_fs_info;
2416 rcu_read_lock();
2417 task = find_task_by_pid_ns(tgid, ns);
2418 if (task)
2419 get_task_struct(task);
2420 rcu_read_unlock();
2421 if (!task)
2422 goto out;
2423
2424 result = proc_pid_instantiate(dir, dentry, task, NULL);
2425 put_task_struct(task);
2426 out:
2427 return result;
2428 }
2429
2430 /*
2431 * Find the first task with tgid >= tgid
2432 *
2433 */
2434 struct tgid_iter {
2435 unsigned int tgid;
2436 struct task_struct *task;
2437 };
2438 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2439 {
2440 struct pid *pid;
2441
2442 if (iter.task)
2443 put_task_struct(iter.task);
2444 rcu_read_lock();
2445 retry:
2446 iter.task = NULL;
2447 pid = find_ge_pid(iter.tgid, ns);
2448 if (pid) {
2449 iter.tgid = pid_nr_ns(pid, ns);
2450 iter.task = pid_task(pid, PIDTYPE_PID);
2451 /* What we to know is if the pid we have find is the
2452 * pid of a thread_group_leader. Testing for task
2453 * being a thread_group_leader is the obvious thing
2454 * todo but there is a window when it fails, due to
2455 * the pid transfer logic in de_thread.
2456 *
2457 * So we perform the straight forward test of seeing
2458 * if the pid we have found is the pid of a thread
2459 * group leader, and don't worry if the task we have
2460 * found doesn't happen to be a thread group leader.
2461 * As we don't care in the case of readdir.
2462 */
2463 if (!iter.task || !has_group_leader_pid(iter.task)) {
2464 iter.tgid += 1;
2465 goto retry;
2466 }
2467 get_task_struct(iter.task);
2468 }
2469 rcu_read_unlock();
2470 return iter;
2471 }
2472
2473 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2474
2475 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2476 struct tgid_iter iter)
2477 {
2478 char name[PROC_NUMBUF];
2479 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2480 return proc_fill_cache(filp, dirent, filldir, name, len,
2481 proc_pid_instantiate, iter.task, NULL);
2482 }
2483
2484 /* for the /proc/ directory itself, after non-process stuff has been done */
2485 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2486 {
2487 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2488 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2489 struct tgid_iter iter;
2490 struct pid_namespace *ns;
2491
2492 if (!reaper)
2493 goto out_no_task;
2494
2495 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2496 const struct pid_entry *p = &proc_base_stuff[nr];
2497 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2498 goto out;
2499 }
2500
2501 ns = filp->f_dentry->d_sb->s_fs_info;
2502 iter.task = NULL;
2503 iter.tgid = filp->f_pos - TGID_OFFSET;
2504 for (iter = next_tgid(ns, iter);
2505 iter.task;
2506 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2507 filp->f_pos = iter.tgid + TGID_OFFSET;
2508 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2509 put_task_struct(iter.task);
2510 goto out;
2511 }
2512 }
2513 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2514 out:
2515 put_task_struct(reaper);
2516 out_no_task:
2517 return 0;
2518 }
2519
2520 /*
2521 * Tasks
2522 */
2523 static const struct pid_entry tid_base_stuff[] = {
2524 DIR("fd", S_IRUSR|S_IXUSR, fd),
2525 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2526 REG("environ", S_IRUSR, environ),
2527 INF("auxv", S_IRUSR, pid_auxv),
2528 INF("status", S_IRUGO, pid_status),
2529 INF("limits", S_IRUSR, pid_limits),
2530 #ifdef CONFIG_SCHED_DEBUG
2531 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2532 #endif
2533 INF("cmdline", S_IRUGO, pid_cmdline),
2534 INF("stat", S_IRUGO, tid_stat),
2535 INF("statm", S_IRUGO, pid_statm),
2536 REG("maps", S_IRUGO, maps),
2537 #ifdef CONFIG_NUMA
2538 REG("numa_maps", S_IRUGO, numa_maps),
2539 #endif
2540 REG("mem", S_IRUSR|S_IWUSR, mem),
2541 LNK("cwd", cwd),
2542 LNK("root", root),
2543 LNK("exe", exe),
2544 REG("mounts", S_IRUGO, mounts),
2545 #ifdef CONFIG_MMU
2546 REG("clear_refs", S_IWUSR, clear_refs),
2547 REG("smaps", S_IRUGO, smaps),
2548 #endif
2549 #ifdef CONFIG_SECURITY
2550 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2551 #endif
2552 #ifdef CONFIG_KALLSYMS
2553 INF("wchan", S_IRUGO, pid_wchan),
2554 #endif
2555 #ifdef CONFIG_SCHEDSTATS
2556 INF("schedstat", S_IRUGO, pid_schedstat),
2557 #endif
2558 #ifdef CONFIG_PROC_PID_CPUSET
2559 REG("cpuset", S_IRUGO, cpuset),
2560 #endif
2561 #ifdef CONFIG_CGROUPS
2562 REG("cgroup", S_IRUGO, cgroup),
2563 #endif
2564 INF("oom_score", S_IRUGO, oom_score),
2565 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2566 #ifdef CONFIG_AUDITSYSCALL
2567 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2568 #endif
2569 #ifdef CONFIG_FAULT_INJECTION
2570 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2571 #endif
2572 };
2573
2574 static int proc_tid_base_readdir(struct file * filp,
2575 void * dirent, filldir_t filldir)
2576 {
2577 return proc_pident_readdir(filp,dirent,filldir,
2578 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2579 }
2580
2581 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2582 return proc_pident_lookup(dir, dentry,
2583 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2584 }
2585
2586 static const struct file_operations proc_tid_base_operations = {
2587 .read = generic_read_dir,
2588 .readdir = proc_tid_base_readdir,
2589 };
2590
2591 static const struct inode_operations proc_tid_base_inode_operations = {
2592 .lookup = proc_tid_base_lookup,
2593 .getattr = pid_getattr,
2594 .setattr = proc_setattr,
2595 };
2596
2597 static struct dentry *proc_task_instantiate(struct inode *dir,
2598 struct dentry *dentry, struct task_struct *task, const void *ptr)
2599 {
2600 struct dentry *error = ERR_PTR(-ENOENT);
2601 struct inode *inode;
2602 inode = proc_pid_make_inode(dir->i_sb, task);
2603
2604 if (!inode)
2605 goto out;
2606 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2607 inode->i_op = &proc_tid_base_inode_operations;
2608 inode->i_fop = &proc_tid_base_operations;
2609 inode->i_flags|=S_IMMUTABLE;
2610 inode->i_nlink = 4;
2611 #ifdef CONFIG_SECURITY
2612 inode->i_nlink += 1;
2613 #endif
2614
2615 dentry->d_op = &pid_dentry_operations;
2616
2617 d_add(dentry, inode);
2618 /* Close the race of the process dying before we return the dentry */
2619 if (pid_revalidate(dentry, NULL))
2620 error = NULL;
2621 out:
2622 return error;
2623 }
2624
2625 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2626 {
2627 struct dentry *result = ERR_PTR(-ENOENT);
2628 struct task_struct *task;
2629 struct task_struct *leader = get_proc_task(dir);
2630 unsigned tid;
2631 struct pid_namespace *ns;
2632
2633 if (!leader)
2634 goto out_no_task;
2635
2636 tid = name_to_int(dentry);
2637 if (tid == ~0U)
2638 goto out;
2639
2640 ns = dentry->d_sb->s_fs_info;
2641 rcu_read_lock();
2642 task = find_task_by_pid_ns(tid, ns);
2643 if (task)
2644 get_task_struct(task);
2645 rcu_read_unlock();
2646 if (!task)
2647 goto out;
2648 if (!same_thread_group(leader, task))
2649 goto out_drop_task;
2650
2651 result = proc_task_instantiate(dir, dentry, task, NULL);
2652 out_drop_task:
2653 put_task_struct(task);
2654 out:
2655 put_task_struct(leader);
2656 out_no_task:
2657 return result;
2658 }
2659
2660 /*
2661 * Find the first tid of a thread group to return to user space.
2662 *
2663 * Usually this is just the thread group leader, but if the users
2664 * buffer was too small or there was a seek into the middle of the
2665 * directory we have more work todo.
2666 *
2667 * In the case of a short read we start with find_task_by_pid.
2668 *
2669 * In the case of a seek we start with the leader and walk nr
2670 * threads past it.
2671 */
2672 static struct task_struct *first_tid(struct task_struct *leader,
2673 int tid, int nr, struct pid_namespace *ns)
2674 {
2675 struct task_struct *pos;
2676
2677 rcu_read_lock();
2678 /* Attempt to start with the pid of a thread */
2679 if (tid && (nr > 0)) {
2680 pos = find_task_by_pid_ns(tid, ns);
2681 if (pos && (pos->group_leader == leader))
2682 goto found;
2683 }
2684
2685 /* If nr exceeds the number of threads there is nothing todo */
2686 pos = NULL;
2687 if (nr && nr >= get_nr_threads(leader))
2688 goto out;
2689
2690 /* If we haven't found our starting place yet start
2691 * with the leader and walk nr threads forward.
2692 */
2693 for (pos = leader; nr > 0; --nr) {
2694 pos = next_thread(pos);
2695 if (pos == leader) {
2696 pos = NULL;
2697 goto out;
2698 }
2699 }
2700 found:
2701 get_task_struct(pos);
2702 out:
2703 rcu_read_unlock();
2704 return pos;
2705 }
2706
2707 /*
2708 * Find the next thread in the thread list.
2709 * Return NULL if there is an error or no next thread.
2710 *
2711 * The reference to the input task_struct is released.
2712 */
2713 static struct task_struct *next_tid(struct task_struct *start)
2714 {
2715 struct task_struct *pos = NULL;
2716 rcu_read_lock();
2717 if (pid_alive(start)) {
2718 pos = next_thread(start);
2719 if (thread_group_leader(pos))
2720 pos = NULL;
2721 else
2722 get_task_struct(pos);
2723 }
2724 rcu_read_unlock();
2725 put_task_struct(start);
2726 return pos;
2727 }
2728
2729 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2730 struct task_struct *task, int tid)
2731 {
2732 char name[PROC_NUMBUF];
2733 int len = snprintf(name, sizeof(name), "%d", tid);
2734 return proc_fill_cache(filp, dirent, filldir, name, len,
2735 proc_task_instantiate, task, NULL);
2736 }
2737
2738 /* for the /proc/TGID/task/ directories */
2739 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2740 {
2741 struct dentry *dentry = filp->f_path.dentry;
2742 struct inode *inode = dentry->d_inode;
2743 struct task_struct *leader = NULL;
2744 struct task_struct *task;
2745 int retval = -ENOENT;
2746 ino_t ino;
2747 int tid;
2748 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2749 struct pid_namespace *ns;
2750
2751 task = get_proc_task(inode);
2752 if (!task)
2753 goto out_no_task;
2754 rcu_read_lock();
2755 if (pid_alive(task)) {
2756 leader = task->group_leader;
2757 get_task_struct(leader);
2758 }
2759 rcu_read_unlock();
2760 put_task_struct(task);
2761 if (!leader)
2762 goto out_no_task;
2763 retval = 0;
2764
2765 switch (pos) {
2766 case 0:
2767 ino = inode->i_ino;
2768 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2769 goto out;
2770 pos++;
2771 /* fall through */
2772 case 1:
2773 ino = parent_ino(dentry);
2774 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2775 goto out;
2776 pos++;
2777 /* fall through */
2778 }
2779
2780 /* f_version caches the tgid value that the last readdir call couldn't
2781 * return. lseek aka telldir automagically resets f_version to 0.
2782 */
2783 ns = filp->f_dentry->d_sb->s_fs_info;
2784 tid = (int)filp->f_version;
2785 filp->f_version = 0;
2786 for (task = first_tid(leader, tid, pos - 2, ns);
2787 task;
2788 task = next_tid(task), pos++) {
2789 tid = task_pid_nr_ns(task, ns);
2790 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2791 /* returning this tgid failed, save it as the first
2792 * pid for the next readir call */
2793 filp->f_version = (u64)tid;
2794 put_task_struct(task);
2795 break;
2796 }
2797 }
2798 out:
2799 filp->f_pos = pos;
2800 put_task_struct(leader);
2801 out_no_task:
2802 return retval;
2803 }
2804
2805 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2806 {
2807 struct inode *inode = dentry->d_inode;
2808 struct task_struct *p = get_proc_task(inode);
2809 generic_fillattr(inode, stat);
2810
2811 if (p) {
2812 rcu_read_lock();
2813 stat->nlink += get_nr_threads(p);
2814 rcu_read_unlock();
2815 put_task_struct(p);
2816 }
2817
2818 return 0;
2819 }
2820
2821 static const struct inode_operations proc_task_inode_operations = {
2822 .lookup = proc_task_lookup,
2823 .getattr = proc_task_getattr,
2824 .setattr = proc_setattr,
2825 };
2826
2827 static const struct file_operations proc_task_operations = {
2828 .read = generic_read_dir,
2829 .readdir = proc_task_readdir,
2830 };
Linux kernel - Deliverables
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