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procfs: constify function pointer tables
[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 struct pid_entry {
92 char *name;
93 int len;
94 mode_t mode;
95 const struct inode_operations *iop;
96 const struct file_operations *fop;
97 union proc_op op;
98 };
99
100 #define NOD(NAME, MODE, IOP, FOP, OP) { \
101 .name = (NAME), \
102 .len = sizeof(NAME) - 1, \
103 .mode = MODE, \
104 .iop = IOP, \
105 .fop = FOP, \
106 .op = OP, \
107 }
108
109 #define DIR(NAME, MODE, OTYPE) \
110 NOD(NAME, (S_IFDIR|(MODE)), \
111 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
112 {} )
113 #define LNK(NAME, OTYPE) \
114 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
115 &proc_pid_link_inode_operations, NULL, \
116 { .proc_get_link = &proc_##OTYPE##_link } )
117 #define REG(NAME, MODE, OTYPE) \
118 NOD(NAME, (S_IFREG|(MODE)), NULL, \
119 &proc_##OTYPE##_operations, {})
120 #define INF(NAME, MODE, OTYPE) \
121 NOD(NAME, (S_IFREG|(MODE)), \
122 NULL, &proc_info_file_operations, \
123 { .proc_read = &proc_##OTYPE } )
124 #define ONE(NAME, MODE, OTYPE) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_single_file_operations, \
127 { .proc_show = &proc_##OTYPE } )
128
129 int maps_protect;
130 EXPORT_SYMBOL(maps_protect);
131
132 static struct fs_struct *get_fs_struct(struct task_struct *task)
133 {
134 struct fs_struct *fs;
135 task_lock(task);
136 fs = task->fs;
137 if(fs)
138 atomic_inc(&fs->count);
139 task_unlock(task);
140 return fs;
141 }
142
143 static int get_nr_threads(struct task_struct *tsk)
144 {
145 /* Must be called with the rcu_read_lock held */
146 unsigned long flags;
147 int count = 0;
148
149 if (lock_task_sighand(tsk, &flags)) {
150 count = atomic_read(&tsk->signal->count);
151 unlock_task_sighand(tsk, &flags);
152 }
153 return count;
154 }
155
156 static int proc_cwd_link(struct inode *inode, struct 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_is_stopped_or_traced(task)) && \
203 security_ptrace(current,task) == 0))
204
205 struct mm_struct *mm_for_maps(struct task_struct *task)
206 {
207 struct mm_struct *mm = get_task_mm(task);
208 if (!mm)
209 return NULL;
210 down_read(&mm->mmap_sem);
211 task_lock(task);
212 if (task->mm != mm)
213 goto out;
214 if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
215 goto out;
216 task_unlock(task);
217 return mm;
218 out:
219 task_unlock(task);
220 up_read(&mm->mmap_sem);
221 mmput(mm);
222 return NULL;
223 }
224
225 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
226 {
227 int res = 0;
228 unsigned int len;
229 struct mm_struct *mm = get_task_mm(task);
230 if (!mm)
231 goto out;
232 if (!mm->arg_end)
233 goto out_mm; /* Shh! No looking before we're done */
234
235 len = mm->arg_end - mm->arg_start;
236
237 if (len > PAGE_SIZE)
238 len = PAGE_SIZE;
239
240 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
241
242 // If the nul at the end of args has been overwritten, then
243 // assume application is using setproctitle(3).
244 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
245 len = strnlen(buffer, res);
246 if (len < res) {
247 res = len;
248 } else {
249 len = mm->env_end - mm->env_start;
250 if (len > PAGE_SIZE - res)
251 len = PAGE_SIZE - res;
252 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
253 res = strnlen(buffer, res);
254 }
255 }
256 out_mm:
257 mmput(mm);
258 out:
259 return res;
260 }
261
262 static int proc_pid_auxv(struct task_struct *task, char *buffer)
263 {
264 int res = 0;
265 struct mm_struct *mm = get_task_mm(task);
266 if (mm) {
267 unsigned int nwords = 0;
268 do
269 nwords += 2;
270 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
271 res = nwords * sizeof(mm->saved_auxv[0]);
272 if (res > PAGE_SIZE)
273 res = PAGE_SIZE;
274 memcpy(buffer, mm->saved_auxv, res);
275 mmput(mm);
276 }
277 return res;
278 }
279
280
281 #ifdef CONFIG_KALLSYMS
282 /*
283 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
284 * Returns the resolved symbol. If that fails, simply return the address.
285 */
286 static int proc_pid_wchan(struct task_struct *task, char *buffer)
287 {
288 unsigned long wchan;
289 char symname[KSYM_NAME_LEN];
290
291 wchan = get_wchan(task);
292
293 if (lookup_symbol_name(wchan, symname) < 0)
294 return sprintf(buffer, "%lu", wchan);
295 else
296 return sprintf(buffer, "%s", symname);
297 }
298 #endif /* CONFIG_KALLSYMS */
299
300 #ifdef CONFIG_SCHEDSTATS
301 /*
302 * Provides /proc/PID/schedstat
303 */
304 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
305 {
306 return sprintf(buffer, "%llu %llu %lu\n",
307 task->sched_info.cpu_time,
308 task->sched_info.run_delay,
309 task->sched_info.pcount);
310 }
311 #endif
312
313 #ifdef CONFIG_LATENCYTOP
314 static int lstats_show_proc(struct seq_file *m, void *v)
315 {
316 int i;
317 struct task_struct *task = m->private;
318 seq_puts(m, "Latency Top version : v0.1\n");
319
320 for (i = 0; i < 32; i++) {
321 if (task->latency_record[i].backtrace[0]) {
322 int q;
323 seq_printf(m, "%i %li %li ",
324 task->latency_record[i].count,
325 task->latency_record[i].time,
326 task->latency_record[i].max);
327 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
328 char sym[KSYM_NAME_LEN];
329 char *c;
330 if (!task->latency_record[i].backtrace[q])
331 break;
332 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
333 break;
334 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
335 c = strchr(sym, '+');
336 if (c)
337 *c = 0;
338 seq_printf(m, "%s ", sym);
339 }
340 seq_printf(m, "\n");
341 }
342
343 }
344 return 0;
345 }
346
347 static int lstats_open(struct inode *inode, struct file *file)
348 {
349 int ret;
350 struct seq_file *m;
351 struct task_struct *task = get_proc_task(inode);
352
353 ret = single_open(file, lstats_show_proc, NULL);
354 if (!ret) {
355 m = file->private_data;
356 m->private = task;
357 }
358 return ret;
359 }
360
361 static ssize_t lstats_write(struct file *file, const char __user *buf,
362 size_t count, loff_t *offs)
363 {
364 struct seq_file *m;
365 struct task_struct *task;
366
367 m = file->private_data;
368 task = m->private;
369 clear_all_latency_tracing(task);
370
371 return count;
372 }
373
374 static const struct file_operations proc_lstats_operations = {
375 .open = lstats_open,
376 .read = seq_read,
377 .write = lstats_write,
378 .llseek = seq_lseek,
379 .release = single_release,
380 };
381
382 #endif
383
384 /* The badness from the OOM killer */
385 unsigned long badness(struct task_struct *p, unsigned long uptime);
386 static int proc_oom_score(struct task_struct *task, char *buffer)
387 {
388 unsigned long points;
389 struct timespec uptime;
390
391 do_posix_clock_monotonic_gettime(&uptime);
392 read_lock(&tasklist_lock);
393 points = badness(task, uptime.tv_sec);
394 read_unlock(&tasklist_lock);
395 return sprintf(buffer, "%lu\n", points);
396 }
397
398 struct limit_names {
399 char *name;
400 char *unit;
401 };
402
403 static const struct limit_names lnames[RLIM_NLIMITS] = {
404 [RLIMIT_CPU] = {"Max cpu time", "ms"},
405 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
406 [RLIMIT_DATA] = {"Max data size", "bytes"},
407 [RLIMIT_STACK] = {"Max stack size", "bytes"},
408 [RLIMIT_CORE] = {"Max core file size", "bytes"},
409 [RLIMIT_RSS] = {"Max resident set", "bytes"},
410 [RLIMIT_NPROC] = {"Max processes", "processes"},
411 [RLIMIT_NOFILE] = {"Max open files", "files"},
412 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
413 [RLIMIT_AS] = {"Max address space", "bytes"},
414 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
415 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
416 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
417 [RLIMIT_NICE] = {"Max nice priority", NULL},
418 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
419 };
420
421 /* Display limits for a process */
422 static int proc_pid_limits(struct task_struct *task, char *buffer)
423 {
424 unsigned int i;
425 int count = 0;
426 unsigned long flags;
427 char *bufptr = buffer;
428
429 struct rlimit rlim[RLIM_NLIMITS];
430
431 rcu_read_lock();
432 if (!lock_task_sighand(task,&flags)) {
433 rcu_read_unlock();
434 return 0;
435 }
436 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
437 unlock_task_sighand(task, &flags);
438 rcu_read_unlock();
439
440 /*
441 * print the file header
442 */
443 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
444 "Limit", "Soft Limit", "Hard Limit", "Units");
445
446 for (i = 0; i < RLIM_NLIMITS; i++) {
447 if (rlim[i].rlim_cur == RLIM_INFINITY)
448 count += sprintf(&bufptr[count], "%-25s %-20s ",
449 lnames[i].name, "unlimited");
450 else
451 count += sprintf(&bufptr[count], "%-25s %-20lu ",
452 lnames[i].name, rlim[i].rlim_cur);
453
454 if (rlim[i].rlim_max == RLIM_INFINITY)
455 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
456 else
457 count += sprintf(&bufptr[count], "%-20lu ",
458 rlim[i].rlim_max);
459
460 if (lnames[i].unit)
461 count += sprintf(&bufptr[count], "%-10s\n",
462 lnames[i].unit);
463 else
464 count += sprintf(&bufptr[count], "\n");
465 }
466
467 return count;
468 }
469
470 /************************************************************************/
471 /* Here the fs part begins */
472 /************************************************************************/
473
474 /* permission checks */
475 static int proc_fd_access_allowed(struct inode *inode)
476 {
477 struct task_struct *task;
478 int allowed = 0;
479 /* Allow access to a task's file descriptors if it is us or we
480 * may use ptrace attach to the process and find out that
481 * information.
482 */
483 task = get_proc_task(inode);
484 if (task) {
485 allowed = ptrace_may_attach(task);
486 put_task_struct(task);
487 }
488 return allowed;
489 }
490
491 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
492 {
493 int error;
494 struct inode *inode = dentry->d_inode;
495
496 if (attr->ia_valid & ATTR_MODE)
497 return -EPERM;
498
499 error = inode_change_ok(inode, attr);
500 if (!error)
501 error = inode_setattr(inode, attr);
502 return error;
503 }
504
505 static const struct inode_operations proc_def_inode_operations = {
506 .setattr = proc_setattr,
507 };
508
509 extern const struct seq_operations mounts_op;
510 struct proc_mounts {
511 struct seq_file m;
512 int event;
513 };
514
515 static int mounts_open(struct inode *inode, struct file *file)
516 {
517 struct task_struct *task = get_proc_task(inode);
518 struct nsproxy *nsp;
519 struct mnt_namespace *ns = NULL;
520 struct proc_mounts *p;
521 int ret = -EINVAL;
522
523 if (task) {
524 rcu_read_lock();
525 nsp = task_nsproxy(task);
526 if (nsp) {
527 ns = nsp->mnt_ns;
528 if (ns)
529 get_mnt_ns(ns);
530 }
531 rcu_read_unlock();
532
533 put_task_struct(task);
534 }
535
536 if (ns) {
537 ret = -ENOMEM;
538 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
539 if (p) {
540 file->private_data = &p->m;
541 ret = seq_open(file, &mounts_op);
542 if (!ret) {
543 p->m.private = ns;
544 p->event = ns->event;
545 return 0;
546 }
547 kfree(p);
548 }
549 put_mnt_ns(ns);
550 }
551 return ret;
552 }
553
554 static int mounts_release(struct inode *inode, struct file *file)
555 {
556 struct seq_file *m = file->private_data;
557 struct mnt_namespace *ns = m->private;
558 put_mnt_ns(ns);
559 return seq_release(inode, file);
560 }
561
562 static unsigned mounts_poll(struct file *file, poll_table *wait)
563 {
564 struct proc_mounts *p = file->private_data;
565 struct mnt_namespace *ns = p->m.private;
566 unsigned res = 0;
567
568 poll_wait(file, &ns->poll, wait);
569
570 spin_lock(&vfsmount_lock);
571 if (p->event != ns->event) {
572 p->event = ns->event;
573 res = POLLERR;
574 }
575 spin_unlock(&vfsmount_lock);
576
577 return res;
578 }
579
580 static const struct file_operations proc_mounts_operations = {
581 .open = mounts_open,
582 .read = seq_read,
583 .llseek = seq_lseek,
584 .release = mounts_release,
585 .poll = mounts_poll,
586 };
587
588 extern const struct seq_operations mountstats_op;
589 static int mountstats_open(struct inode *inode, struct file *file)
590 {
591 int ret = seq_open(file, &mountstats_op);
592
593 if (!ret) {
594 struct seq_file *m = file->private_data;
595 struct nsproxy *nsp;
596 struct mnt_namespace *mnt_ns = NULL;
597 struct task_struct *task = get_proc_task(inode);
598
599 if (task) {
600 rcu_read_lock();
601 nsp = task_nsproxy(task);
602 if (nsp) {
603 mnt_ns = nsp->mnt_ns;
604 if (mnt_ns)
605 get_mnt_ns(mnt_ns);
606 }
607 rcu_read_unlock();
608
609 put_task_struct(task);
610 }
611
612 if (mnt_ns)
613 m->private = mnt_ns;
614 else {
615 seq_release(inode, file);
616 ret = -EINVAL;
617 }
618 }
619 return ret;
620 }
621
622 static const struct file_operations proc_mountstats_operations = {
623 .open = mountstats_open,
624 .read = seq_read,
625 .llseek = seq_lseek,
626 .release = mounts_release,
627 };
628
629 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
630
631 static ssize_t proc_info_read(struct file * file, char __user * buf,
632 size_t count, loff_t *ppos)
633 {
634 struct inode * inode = file->f_path.dentry->d_inode;
635 unsigned long page;
636 ssize_t length;
637 struct task_struct *task = get_proc_task(inode);
638
639 length = -ESRCH;
640 if (!task)
641 goto out_no_task;
642
643 if (count > PROC_BLOCK_SIZE)
644 count = PROC_BLOCK_SIZE;
645
646 length = -ENOMEM;
647 if (!(page = __get_free_page(GFP_TEMPORARY)))
648 goto out;
649
650 length = PROC_I(inode)->op.proc_read(task, (char*)page);
651
652 if (length >= 0)
653 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
654 free_page(page);
655 out:
656 put_task_struct(task);
657 out_no_task:
658 return length;
659 }
660
661 static const struct file_operations proc_info_file_operations = {
662 .read = proc_info_read,
663 };
664
665 static int proc_single_show(struct seq_file *m, void *v)
666 {
667 struct inode *inode = m->private;
668 struct pid_namespace *ns;
669 struct pid *pid;
670 struct task_struct *task;
671 int ret;
672
673 ns = inode->i_sb->s_fs_info;
674 pid = proc_pid(inode);
675 task = get_pid_task(pid, PIDTYPE_PID);
676 if (!task)
677 return -ESRCH;
678
679 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
680
681 put_task_struct(task);
682 return ret;
683 }
684
685 static int proc_single_open(struct inode *inode, struct file *filp)
686 {
687 int ret;
688 ret = single_open(filp, proc_single_show, NULL);
689 if (!ret) {
690 struct seq_file *m = filp->private_data;
691
692 m->private = inode;
693 }
694 return ret;
695 }
696
697 static const struct file_operations proc_single_file_operations = {
698 .open = proc_single_open,
699 .read = seq_read,
700 .llseek = seq_lseek,
701 .release = single_release,
702 };
703
704 static int mem_open(struct inode* inode, struct file* file)
705 {
706 file->private_data = (void*)((long)current->self_exec_id);
707 return 0;
708 }
709
710 static ssize_t mem_read(struct file * file, char __user * buf,
711 size_t count, loff_t *ppos)
712 {
713 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
714 char *page;
715 unsigned long src = *ppos;
716 int ret = -ESRCH;
717 struct mm_struct *mm;
718
719 if (!task)
720 goto out_no_task;
721
722 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
723 goto out;
724
725 ret = -ENOMEM;
726 page = (char *)__get_free_page(GFP_TEMPORARY);
727 if (!page)
728 goto out;
729
730 ret = 0;
731
732 mm = get_task_mm(task);
733 if (!mm)
734 goto out_free;
735
736 ret = -EIO;
737
738 if (file->private_data != (void*)((long)current->self_exec_id))
739 goto out_put;
740
741 ret = 0;
742
743 while (count > 0) {
744 int this_len, retval;
745
746 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
747 retval = access_process_vm(task, src, page, this_len, 0);
748 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
749 if (!ret)
750 ret = -EIO;
751 break;
752 }
753
754 if (copy_to_user(buf, page, retval)) {
755 ret = -EFAULT;
756 break;
757 }
758
759 ret += retval;
760 src += retval;
761 buf += retval;
762 count -= retval;
763 }
764 *ppos = src;
765
766 out_put:
767 mmput(mm);
768 out_free:
769 free_page((unsigned long) page);
770 out:
771 put_task_struct(task);
772 out_no_task:
773 return ret;
774 }
775
776 #define mem_write NULL
777
778 #ifndef mem_write
779 /* This is a security hazard */
780 static ssize_t mem_write(struct file * file, const char __user *buf,
781 size_t count, loff_t *ppos)
782 {
783 int copied;
784 char *page;
785 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
786 unsigned long dst = *ppos;
787
788 copied = -ESRCH;
789 if (!task)
790 goto out_no_task;
791
792 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
793 goto out;
794
795 copied = -ENOMEM;
796 page = (char *)__get_free_page(GFP_TEMPORARY);
797 if (!page)
798 goto out;
799
800 copied = 0;
801 while (count > 0) {
802 int this_len, retval;
803
804 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
805 if (copy_from_user(page, buf, this_len)) {
806 copied = -EFAULT;
807 break;
808 }
809 retval = access_process_vm(task, dst, page, this_len, 1);
810 if (!retval) {
811 if (!copied)
812 copied = -EIO;
813 break;
814 }
815 copied += retval;
816 buf += retval;
817 dst += retval;
818 count -= retval;
819 }
820 *ppos = dst;
821 free_page((unsigned long) page);
822 out:
823 put_task_struct(task);
824 out_no_task:
825 return copied;
826 }
827 #endif
828
829 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
830 {
831 switch (orig) {
832 case 0:
833 file->f_pos = offset;
834 break;
835 case 1:
836 file->f_pos += offset;
837 break;
838 default:
839 return -EINVAL;
840 }
841 force_successful_syscall_return();
842 return file->f_pos;
843 }
844
845 static const struct file_operations proc_mem_operations = {
846 .llseek = mem_lseek,
847 .read = mem_read,
848 .write = mem_write,
849 .open = mem_open,
850 };
851
852 static ssize_t environ_read(struct file *file, char __user *buf,
853 size_t count, loff_t *ppos)
854 {
855 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
856 char *page;
857 unsigned long src = *ppos;
858 int ret = -ESRCH;
859 struct mm_struct *mm;
860
861 if (!task)
862 goto out_no_task;
863
864 if (!ptrace_may_attach(task))
865 goto out;
866
867 ret = -ENOMEM;
868 page = (char *)__get_free_page(GFP_TEMPORARY);
869 if (!page)
870 goto out;
871
872 ret = 0;
873
874 mm = get_task_mm(task);
875 if (!mm)
876 goto out_free;
877
878 while (count > 0) {
879 int this_len, retval, max_len;
880
881 this_len = mm->env_end - (mm->env_start + src);
882
883 if (this_len <= 0)
884 break;
885
886 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
887 this_len = (this_len > max_len) ? max_len : this_len;
888
889 retval = access_process_vm(task, (mm->env_start + src),
890 page, this_len, 0);
891
892 if (retval <= 0) {
893 ret = retval;
894 break;
895 }
896
897 if (copy_to_user(buf, page, retval)) {
898 ret = -EFAULT;
899 break;
900 }
901
902 ret += retval;
903 src += retval;
904 buf += retval;
905 count -= retval;
906 }
907 *ppos = src;
908
909 mmput(mm);
910 out_free:
911 free_page((unsigned long) page);
912 out:
913 put_task_struct(task);
914 out_no_task:
915 return ret;
916 }
917
918 static const struct file_operations proc_environ_operations = {
919 .read = environ_read,
920 };
921
922 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
923 size_t count, loff_t *ppos)
924 {
925 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
926 char buffer[PROC_NUMBUF];
927 size_t len;
928 int oom_adjust;
929
930 if (!task)
931 return -ESRCH;
932 oom_adjust = task->oomkilladj;
933 put_task_struct(task);
934
935 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
936
937 return simple_read_from_buffer(buf, count, ppos, buffer, len);
938 }
939
940 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
941 size_t count, loff_t *ppos)
942 {
943 struct task_struct *task;
944 char buffer[PROC_NUMBUF], *end;
945 int oom_adjust;
946
947 memset(buffer, 0, sizeof(buffer));
948 if (count > sizeof(buffer) - 1)
949 count = sizeof(buffer) - 1;
950 if (copy_from_user(buffer, buf, count))
951 return -EFAULT;
952 oom_adjust = simple_strtol(buffer, &end, 0);
953 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
954 oom_adjust != OOM_DISABLE)
955 return -EINVAL;
956 if (*end == '\n')
957 end++;
958 task = get_proc_task(file->f_path.dentry->d_inode);
959 if (!task)
960 return -ESRCH;
961 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
962 put_task_struct(task);
963 return -EACCES;
964 }
965 task->oomkilladj = oom_adjust;
966 put_task_struct(task);
967 if (end - buffer == 0)
968 return -EIO;
969 return end - buffer;
970 }
971
972 static const struct file_operations proc_oom_adjust_operations = {
973 .read = oom_adjust_read,
974 .write = oom_adjust_write,
975 };
976
977 #ifdef CONFIG_AUDITSYSCALL
978 #define TMPBUFLEN 21
979 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
980 size_t count, loff_t *ppos)
981 {
982 struct inode * inode = file->f_path.dentry->d_inode;
983 struct task_struct *task = get_proc_task(inode);
984 ssize_t length;
985 char tmpbuf[TMPBUFLEN];
986
987 if (!task)
988 return -ESRCH;
989 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
990 audit_get_loginuid(task));
991 put_task_struct(task);
992 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
993 }
994
995 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
996 size_t count, loff_t *ppos)
997 {
998 struct inode * inode = file->f_path.dentry->d_inode;
999 char *page, *tmp;
1000 ssize_t length;
1001 uid_t loginuid;
1002
1003 if (!capable(CAP_AUDIT_CONTROL))
1004 return -EPERM;
1005
1006 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1007 return -EPERM;
1008
1009 if (count >= PAGE_SIZE)
1010 count = PAGE_SIZE - 1;
1011
1012 if (*ppos != 0) {
1013 /* No partial writes. */
1014 return -EINVAL;
1015 }
1016 page = (char*)__get_free_page(GFP_TEMPORARY);
1017 if (!page)
1018 return -ENOMEM;
1019 length = -EFAULT;
1020 if (copy_from_user(page, buf, count))
1021 goto out_free_page;
1022
1023 page[count] = '\0';
1024 loginuid = simple_strtoul(page, &tmp, 10);
1025 if (tmp == page) {
1026 length = -EINVAL;
1027 goto out_free_page;
1028
1029 }
1030 length = audit_set_loginuid(current, loginuid);
1031 if (likely(length == 0))
1032 length = count;
1033
1034 out_free_page:
1035 free_page((unsigned long) page);
1036 return length;
1037 }
1038
1039 static const struct file_operations proc_loginuid_operations = {
1040 .read = proc_loginuid_read,
1041 .write = proc_loginuid_write,
1042 };
1043 #endif
1044
1045 #ifdef CONFIG_FAULT_INJECTION
1046 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1047 size_t count, loff_t *ppos)
1048 {
1049 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1050 char buffer[PROC_NUMBUF];
1051 size_t len;
1052 int make_it_fail;
1053
1054 if (!task)
1055 return -ESRCH;
1056 make_it_fail = task->make_it_fail;
1057 put_task_struct(task);
1058
1059 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1060
1061 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1062 }
1063
1064 static ssize_t proc_fault_inject_write(struct file * file,
1065 const char __user * buf, size_t count, loff_t *ppos)
1066 {
1067 struct task_struct *task;
1068 char buffer[PROC_NUMBUF], *end;
1069 int make_it_fail;
1070
1071 if (!capable(CAP_SYS_RESOURCE))
1072 return -EPERM;
1073 memset(buffer, 0, sizeof(buffer));
1074 if (count > sizeof(buffer) - 1)
1075 count = sizeof(buffer) - 1;
1076 if (copy_from_user(buffer, buf, count))
1077 return -EFAULT;
1078 make_it_fail = simple_strtol(buffer, &end, 0);
1079 if (*end == '\n')
1080 end++;
1081 task = get_proc_task(file->f_dentry->d_inode);
1082 if (!task)
1083 return -ESRCH;
1084 task->make_it_fail = make_it_fail;
1085 put_task_struct(task);
1086 if (end - buffer == 0)
1087 return -EIO;
1088 return end - buffer;
1089 }
1090
1091 static const struct file_operations proc_fault_inject_operations = {
1092 .read = proc_fault_inject_read,
1093 .write = proc_fault_inject_write,
1094 };
1095 #endif
1096
1097
1098 #ifdef CONFIG_SCHED_DEBUG
1099 /*
1100 * Print out various scheduling related per-task fields:
1101 */
1102 static int sched_show(struct seq_file *m, void *v)
1103 {
1104 struct inode *inode = m->private;
1105 struct task_struct *p;
1106
1107 WARN_ON(!inode);
1108
1109 p = get_proc_task(inode);
1110 if (!p)
1111 return -ESRCH;
1112 proc_sched_show_task(p, m);
1113
1114 put_task_struct(p);
1115
1116 return 0;
1117 }
1118
1119 static ssize_t
1120 sched_write(struct file *file, const char __user *buf,
1121 size_t count, loff_t *offset)
1122 {
1123 struct inode *inode = file->f_path.dentry->d_inode;
1124 struct task_struct *p;
1125
1126 WARN_ON(!inode);
1127
1128 p = get_proc_task(inode);
1129 if (!p)
1130 return -ESRCH;
1131 proc_sched_set_task(p);
1132
1133 put_task_struct(p);
1134
1135 return count;
1136 }
1137
1138 static int sched_open(struct inode *inode, struct file *filp)
1139 {
1140 int ret;
1141
1142 ret = single_open(filp, sched_show, NULL);
1143 if (!ret) {
1144 struct seq_file *m = filp->private_data;
1145
1146 m->private = inode;
1147 }
1148 return ret;
1149 }
1150
1151 static const struct file_operations proc_pid_sched_operations = {
1152 .open = sched_open,
1153 .read = seq_read,
1154 .write = sched_write,
1155 .llseek = seq_lseek,
1156 .release = single_release,
1157 };
1158
1159 #endif
1160
1161 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1162 {
1163 struct inode *inode = dentry->d_inode;
1164 int error = -EACCES;
1165
1166 /* We don't need a base pointer in the /proc filesystem */
1167 path_release(nd);
1168
1169 /* Are we allowed to snoop on the tasks file descriptors? */
1170 if (!proc_fd_access_allowed(inode))
1171 goto out;
1172
1173 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1174 nd->last_type = LAST_BIND;
1175 out:
1176 return ERR_PTR(error);
1177 }
1178
1179 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1180 char __user *buffer, int buflen)
1181 {
1182 struct inode * inode;
1183 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1184 char *path;
1185 int len;
1186
1187 if (!tmp)
1188 return -ENOMEM;
1189
1190 inode = dentry->d_inode;
1191 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1192 len = PTR_ERR(path);
1193 if (IS_ERR(path))
1194 goto out;
1195 len = tmp + PAGE_SIZE - 1 - path;
1196
1197 if (len > buflen)
1198 len = buflen;
1199 if (copy_to_user(buffer, path, len))
1200 len = -EFAULT;
1201 out:
1202 free_page((unsigned long)tmp);
1203 return len;
1204 }
1205
1206 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1207 {
1208 int error = -EACCES;
1209 struct inode *inode = dentry->d_inode;
1210 struct dentry *de;
1211 struct vfsmount *mnt = NULL;
1212
1213 /* Are we allowed to snoop on the tasks file descriptors? */
1214 if (!proc_fd_access_allowed(inode))
1215 goto out;
1216
1217 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1218 if (error)
1219 goto out;
1220
1221 error = do_proc_readlink(de, mnt, buffer, buflen);
1222 dput(de);
1223 mntput(mnt);
1224 out:
1225 return error;
1226 }
1227
1228 static const struct inode_operations proc_pid_link_inode_operations = {
1229 .readlink = proc_pid_readlink,
1230 .follow_link = proc_pid_follow_link,
1231 .setattr = proc_setattr,
1232 };
1233
1234
1235 /* building an inode */
1236
1237 static int task_dumpable(struct task_struct *task)
1238 {
1239 int dumpable = 0;
1240 struct mm_struct *mm;
1241
1242 task_lock(task);
1243 mm = task->mm;
1244 if (mm)
1245 dumpable = get_dumpable(mm);
1246 task_unlock(task);
1247 if(dumpable == 1)
1248 return 1;
1249 return 0;
1250 }
1251
1252
1253 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1254 {
1255 struct inode * inode;
1256 struct proc_inode *ei;
1257
1258 /* We need a new inode */
1259
1260 inode = new_inode(sb);
1261 if (!inode)
1262 goto out;
1263
1264 /* Common stuff */
1265 ei = PROC_I(inode);
1266 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1267 inode->i_op = &proc_def_inode_operations;
1268
1269 /*
1270 * grab the reference to task.
1271 */
1272 ei->pid = get_task_pid(task, PIDTYPE_PID);
1273 if (!ei->pid)
1274 goto out_unlock;
1275
1276 inode->i_uid = 0;
1277 inode->i_gid = 0;
1278 if (task_dumpable(task)) {
1279 inode->i_uid = task->euid;
1280 inode->i_gid = task->egid;
1281 }
1282 security_task_to_inode(task, inode);
1283
1284 out:
1285 return inode;
1286
1287 out_unlock:
1288 iput(inode);
1289 return NULL;
1290 }
1291
1292 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1293 {
1294 struct inode *inode = dentry->d_inode;
1295 struct task_struct *task;
1296 generic_fillattr(inode, stat);
1297
1298 rcu_read_lock();
1299 stat->uid = 0;
1300 stat->gid = 0;
1301 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1302 if (task) {
1303 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1304 task_dumpable(task)) {
1305 stat->uid = task->euid;
1306 stat->gid = task->egid;
1307 }
1308 }
1309 rcu_read_unlock();
1310 return 0;
1311 }
1312
1313 /* dentry stuff */
1314
1315 /*
1316 * Exceptional case: normally we are not allowed to unhash a busy
1317 * directory. In this case, however, we can do it - no aliasing problems
1318 * due to the way we treat inodes.
1319 *
1320 * Rewrite the inode's ownerships here because the owning task may have
1321 * performed a setuid(), etc.
1322 *
1323 * Before the /proc/pid/status file was created the only way to read
1324 * the effective uid of a /process was to stat /proc/pid. Reading
1325 * /proc/pid/status is slow enough that procps and other packages
1326 * kept stating /proc/pid. To keep the rules in /proc simple I have
1327 * made this apply to all per process world readable and executable
1328 * directories.
1329 */
1330 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1331 {
1332 struct inode *inode = dentry->d_inode;
1333 struct task_struct *task = get_proc_task(inode);
1334 if (task) {
1335 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1336 task_dumpable(task)) {
1337 inode->i_uid = task->euid;
1338 inode->i_gid = task->egid;
1339 } else {
1340 inode->i_uid = 0;
1341 inode->i_gid = 0;
1342 }
1343 inode->i_mode &= ~(S_ISUID | S_ISGID);
1344 security_task_to_inode(task, inode);
1345 put_task_struct(task);
1346 return 1;
1347 }
1348 d_drop(dentry);
1349 return 0;
1350 }
1351
1352 static int pid_delete_dentry(struct dentry * dentry)
1353 {
1354 /* Is the task we represent dead?
1355 * If so, then don't put the dentry on the lru list,
1356 * kill it immediately.
1357 */
1358 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1359 }
1360
1361 static struct dentry_operations pid_dentry_operations =
1362 {
1363 .d_revalidate = pid_revalidate,
1364 .d_delete = pid_delete_dentry,
1365 };
1366
1367 /* Lookups */
1368
1369 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1370 struct task_struct *, const void *);
1371
1372 /*
1373 * Fill a directory entry.
1374 *
1375 * If possible create the dcache entry and derive our inode number and
1376 * file type from dcache entry.
1377 *
1378 * Since all of the proc inode numbers are dynamically generated, the inode
1379 * numbers do not exist until the inode is cache. This means creating the
1380 * the dcache entry in readdir is necessary to keep the inode numbers
1381 * reported by readdir in sync with the inode numbers reported
1382 * by stat.
1383 */
1384 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1385 char *name, int len,
1386 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1387 {
1388 struct dentry *child, *dir = filp->f_path.dentry;
1389 struct inode *inode;
1390 struct qstr qname;
1391 ino_t ino = 0;
1392 unsigned type = DT_UNKNOWN;
1393
1394 qname.name = name;
1395 qname.len = len;
1396 qname.hash = full_name_hash(name, len);
1397
1398 child = d_lookup(dir, &qname);
1399 if (!child) {
1400 struct dentry *new;
1401 new = d_alloc(dir, &qname);
1402 if (new) {
1403 child = instantiate(dir->d_inode, new, task, ptr);
1404 if (child)
1405 dput(new);
1406 else
1407 child = new;
1408 }
1409 }
1410 if (!child || IS_ERR(child) || !child->d_inode)
1411 goto end_instantiate;
1412 inode = child->d_inode;
1413 if (inode) {
1414 ino = inode->i_ino;
1415 type = inode->i_mode >> 12;
1416 }
1417 dput(child);
1418 end_instantiate:
1419 if (!ino)
1420 ino = find_inode_number(dir, &qname);
1421 if (!ino)
1422 ino = 1;
1423 return filldir(dirent, name, len, filp->f_pos, ino, type);
1424 }
1425
1426 static unsigned name_to_int(struct dentry *dentry)
1427 {
1428 const char *name = dentry->d_name.name;
1429 int len = dentry->d_name.len;
1430 unsigned n = 0;
1431
1432 if (len > 1 && *name == '0')
1433 goto out;
1434 while (len-- > 0) {
1435 unsigned c = *name++ - '0';
1436 if (c > 9)
1437 goto out;
1438 if (n >= (~0U-9)/10)
1439 goto out;
1440 n *= 10;
1441 n += c;
1442 }
1443 return n;
1444 out:
1445 return ~0U;
1446 }
1447
1448 #define PROC_FDINFO_MAX 64
1449
1450 static int proc_fd_info(struct inode *inode, struct dentry **dentry,
1451 struct vfsmount **mnt, char *info)
1452 {
1453 struct task_struct *task = get_proc_task(inode);
1454 struct files_struct *files = NULL;
1455 struct file *file;
1456 int fd = proc_fd(inode);
1457
1458 if (task) {
1459 files = get_files_struct(task);
1460 put_task_struct(task);
1461 }
1462 if (files) {
1463 /*
1464 * We are not taking a ref to the file structure, so we must
1465 * hold ->file_lock.
1466 */
1467 spin_lock(&files->file_lock);
1468 file = fcheck_files(files, fd);
1469 if (file) {
1470 if (mnt)
1471 *mnt = mntget(file->f_path.mnt);
1472 if (dentry)
1473 *dentry = dget(file->f_path.dentry);
1474 if (info)
1475 snprintf(info, PROC_FDINFO_MAX,
1476 "pos:\t%lli\n"
1477 "flags:\t0%o\n",
1478 (long long) file->f_pos,
1479 file->f_flags);
1480 spin_unlock(&files->file_lock);
1481 put_files_struct(files);
1482 return 0;
1483 }
1484 spin_unlock(&files->file_lock);
1485 put_files_struct(files);
1486 }
1487 return -ENOENT;
1488 }
1489
1490 static int proc_fd_link(struct inode *inode, struct dentry **dentry,
1491 struct vfsmount **mnt)
1492 {
1493 return proc_fd_info(inode, dentry, mnt, NULL);
1494 }
1495
1496 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1497 {
1498 struct inode *inode = dentry->d_inode;
1499 struct task_struct *task = get_proc_task(inode);
1500 int fd = proc_fd(inode);
1501 struct files_struct *files;
1502
1503 if (task) {
1504 files = get_files_struct(task);
1505 if (files) {
1506 rcu_read_lock();
1507 if (fcheck_files(files, fd)) {
1508 rcu_read_unlock();
1509 put_files_struct(files);
1510 if (task_dumpable(task)) {
1511 inode->i_uid = task->euid;
1512 inode->i_gid = task->egid;
1513 } else {
1514 inode->i_uid = 0;
1515 inode->i_gid = 0;
1516 }
1517 inode->i_mode &= ~(S_ISUID | S_ISGID);
1518 security_task_to_inode(task, inode);
1519 put_task_struct(task);
1520 return 1;
1521 }
1522 rcu_read_unlock();
1523 put_files_struct(files);
1524 }
1525 put_task_struct(task);
1526 }
1527 d_drop(dentry);
1528 return 0;
1529 }
1530
1531 static struct dentry_operations tid_fd_dentry_operations =
1532 {
1533 .d_revalidate = tid_fd_revalidate,
1534 .d_delete = pid_delete_dentry,
1535 };
1536
1537 static struct dentry *proc_fd_instantiate(struct inode *dir,
1538 struct dentry *dentry, struct task_struct *task, const void *ptr)
1539 {
1540 unsigned fd = *(const unsigned *)ptr;
1541 struct file *file;
1542 struct files_struct *files;
1543 struct inode *inode;
1544 struct proc_inode *ei;
1545 struct dentry *error = ERR_PTR(-ENOENT);
1546
1547 inode = proc_pid_make_inode(dir->i_sb, task);
1548 if (!inode)
1549 goto out;
1550 ei = PROC_I(inode);
1551 ei->fd = fd;
1552 files = get_files_struct(task);
1553 if (!files)
1554 goto out_iput;
1555 inode->i_mode = S_IFLNK;
1556
1557 /*
1558 * We are not taking a ref to the file structure, so we must
1559 * hold ->file_lock.
1560 */
1561 spin_lock(&files->file_lock);
1562 file = fcheck_files(files, fd);
1563 if (!file)
1564 goto out_unlock;
1565 if (file->f_mode & 1)
1566 inode->i_mode |= S_IRUSR | S_IXUSR;
1567 if (file->f_mode & 2)
1568 inode->i_mode |= S_IWUSR | S_IXUSR;
1569 spin_unlock(&files->file_lock);
1570 put_files_struct(files);
1571
1572 inode->i_op = &proc_pid_link_inode_operations;
1573 inode->i_size = 64;
1574 ei->op.proc_get_link = proc_fd_link;
1575 dentry->d_op = &tid_fd_dentry_operations;
1576 d_add(dentry, inode);
1577 /* Close the race of the process dying before we return the dentry */
1578 if (tid_fd_revalidate(dentry, NULL))
1579 error = NULL;
1580
1581 out:
1582 return error;
1583 out_unlock:
1584 spin_unlock(&files->file_lock);
1585 put_files_struct(files);
1586 out_iput:
1587 iput(inode);
1588 goto out;
1589 }
1590
1591 static struct dentry *proc_lookupfd_common(struct inode *dir,
1592 struct dentry *dentry,
1593 instantiate_t instantiate)
1594 {
1595 struct task_struct *task = get_proc_task(dir);
1596 unsigned fd = name_to_int(dentry);
1597 struct dentry *result = ERR_PTR(-ENOENT);
1598
1599 if (!task)
1600 goto out_no_task;
1601 if (fd == ~0U)
1602 goto out;
1603
1604 result = instantiate(dir, dentry, task, &fd);
1605 out:
1606 put_task_struct(task);
1607 out_no_task:
1608 return result;
1609 }
1610
1611 static int proc_readfd_common(struct file * filp, void * dirent,
1612 filldir_t filldir, instantiate_t instantiate)
1613 {
1614 struct dentry *dentry = filp->f_path.dentry;
1615 struct inode *inode = dentry->d_inode;
1616 struct task_struct *p = get_proc_task(inode);
1617 unsigned int fd, ino;
1618 int retval;
1619 struct files_struct * files;
1620 struct fdtable *fdt;
1621
1622 retval = -ENOENT;
1623 if (!p)
1624 goto out_no_task;
1625 retval = 0;
1626
1627 fd = filp->f_pos;
1628 switch (fd) {
1629 case 0:
1630 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1631 goto out;
1632 filp->f_pos++;
1633 case 1:
1634 ino = parent_ino(dentry);
1635 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1636 goto out;
1637 filp->f_pos++;
1638 default:
1639 files = get_files_struct(p);
1640 if (!files)
1641 goto out;
1642 rcu_read_lock();
1643 fdt = files_fdtable(files);
1644 for (fd = filp->f_pos-2;
1645 fd < fdt->max_fds;
1646 fd++, filp->f_pos++) {
1647 char name[PROC_NUMBUF];
1648 int len;
1649
1650 if (!fcheck_files(files, fd))
1651 continue;
1652 rcu_read_unlock();
1653
1654 len = snprintf(name, sizeof(name), "%d", fd);
1655 if (proc_fill_cache(filp, dirent, filldir,
1656 name, len, instantiate,
1657 p, &fd) < 0) {
1658 rcu_read_lock();
1659 break;
1660 }
1661 rcu_read_lock();
1662 }
1663 rcu_read_unlock();
1664 put_files_struct(files);
1665 }
1666 out:
1667 put_task_struct(p);
1668 out_no_task:
1669 return retval;
1670 }
1671
1672 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1673 struct nameidata *nd)
1674 {
1675 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1676 }
1677
1678 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1679 {
1680 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1681 }
1682
1683 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1684 size_t len, loff_t *ppos)
1685 {
1686 char tmp[PROC_FDINFO_MAX];
1687 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
1688 if (!err)
1689 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1690 return err;
1691 }
1692
1693 static const struct file_operations proc_fdinfo_file_operations = {
1694 .open = nonseekable_open,
1695 .read = proc_fdinfo_read,
1696 };
1697
1698 static const struct file_operations proc_fd_operations = {
1699 .read = generic_read_dir,
1700 .readdir = proc_readfd,
1701 };
1702
1703 /*
1704 * /proc/pid/fd needs a special permission handler so that a process can still
1705 * access /proc/self/fd after it has executed a setuid().
1706 */
1707 static int proc_fd_permission(struct inode *inode, int mask,
1708 struct nameidata *nd)
1709 {
1710 int rv;
1711
1712 rv = generic_permission(inode, mask, NULL);
1713 if (rv == 0)
1714 return 0;
1715 if (task_pid(current) == proc_pid(inode))
1716 rv = 0;
1717 return rv;
1718 }
1719
1720 /*
1721 * proc directories can do almost nothing..
1722 */
1723 static const struct inode_operations proc_fd_inode_operations = {
1724 .lookup = proc_lookupfd,
1725 .permission = proc_fd_permission,
1726 .setattr = proc_setattr,
1727 };
1728
1729 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1730 struct dentry *dentry, struct task_struct *task, const void *ptr)
1731 {
1732 unsigned fd = *(unsigned *)ptr;
1733 struct inode *inode;
1734 struct proc_inode *ei;
1735 struct dentry *error = ERR_PTR(-ENOENT);
1736
1737 inode = proc_pid_make_inode(dir->i_sb, task);
1738 if (!inode)
1739 goto out;
1740 ei = PROC_I(inode);
1741 ei->fd = fd;
1742 inode->i_mode = S_IFREG | S_IRUSR;
1743 inode->i_fop = &proc_fdinfo_file_operations;
1744 dentry->d_op = &tid_fd_dentry_operations;
1745 d_add(dentry, inode);
1746 /* Close the race of the process dying before we return the dentry */
1747 if (tid_fd_revalidate(dentry, NULL))
1748 error = NULL;
1749
1750 out:
1751 return error;
1752 }
1753
1754 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1755 struct dentry *dentry,
1756 struct nameidata *nd)
1757 {
1758 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1759 }
1760
1761 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1762 {
1763 return proc_readfd_common(filp, dirent, filldir,
1764 proc_fdinfo_instantiate);
1765 }
1766
1767 static const struct file_operations proc_fdinfo_operations = {
1768 .read = generic_read_dir,
1769 .readdir = proc_readfdinfo,
1770 };
1771
1772 /*
1773 * proc directories can do almost nothing..
1774 */
1775 static const struct inode_operations proc_fdinfo_inode_operations = {
1776 .lookup = proc_lookupfdinfo,
1777 .setattr = proc_setattr,
1778 };
1779
1780
1781 static struct dentry *proc_pident_instantiate(struct inode *dir,
1782 struct dentry *dentry, struct task_struct *task, const void *ptr)
1783 {
1784 const struct pid_entry *p = ptr;
1785 struct inode *inode;
1786 struct proc_inode *ei;
1787 struct dentry *error = ERR_PTR(-EINVAL);
1788
1789 inode = proc_pid_make_inode(dir->i_sb, task);
1790 if (!inode)
1791 goto out;
1792
1793 ei = PROC_I(inode);
1794 inode->i_mode = p->mode;
1795 if (S_ISDIR(inode->i_mode))
1796 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1797 if (p->iop)
1798 inode->i_op = p->iop;
1799 if (p->fop)
1800 inode->i_fop = p->fop;
1801 ei->op = p->op;
1802 dentry->d_op = &pid_dentry_operations;
1803 d_add(dentry, inode);
1804 /* Close the race of the process dying before we return the dentry */
1805 if (pid_revalidate(dentry, NULL))
1806 error = NULL;
1807 out:
1808 return error;
1809 }
1810
1811 static struct dentry *proc_pident_lookup(struct inode *dir,
1812 struct dentry *dentry,
1813 const struct pid_entry *ents,
1814 unsigned int nents)
1815 {
1816 struct inode *inode;
1817 struct dentry *error;
1818 struct task_struct *task = get_proc_task(dir);
1819 const struct pid_entry *p, *last;
1820
1821 error = ERR_PTR(-ENOENT);
1822 inode = NULL;
1823
1824 if (!task)
1825 goto out_no_task;
1826
1827 /*
1828 * Yes, it does not scale. And it should not. Don't add
1829 * new entries into /proc/<tgid>/ without very good reasons.
1830 */
1831 last = &ents[nents - 1];
1832 for (p = ents; p <= last; p++) {
1833 if (p->len != dentry->d_name.len)
1834 continue;
1835 if (!memcmp(dentry->d_name.name, p->name, p->len))
1836 break;
1837 }
1838 if (p > last)
1839 goto out;
1840
1841 error = proc_pident_instantiate(dir, dentry, task, p);
1842 out:
1843 put_task_struct(task);
1844 out_no_task:
1845 return error;
1846 }
1847
1848 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1849 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1850 {
1851 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1852 proc_pident_instantiate, task, p);
1853 }
1854
1855 static int proc_pident_readdir(struct file *filp,
1856 void *dirent, filldir_t filldir,
1857 const struct pid_entry *ents, unsigned int nents)
1858 {
1859 int i;
1860 struct dentry *dentry = filp->f_path.dentry;
1861 struct inode *inode = dentry->d_inode;
1862 struct task_struct *task = get_proc_task(inode);
1863 const struct pid_entry *p, *last;
1864 ino_t ino;
1865 int ret;
1866
1867 ret = -ENOENT;
1868 if (!task)
1869 goto out_no_task;
1870
1871 ret = 0;
1872 i = filp->f_pos;
1873 switch (i) {
1874 case 0:
1875 ino = inode->i_ino;
1876 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1877 goto out;
1878 i++;
1879 filp->f_pos++;
1880 /* fall through */
1881 case 1:
1882 ino = parent_ino(dentry);
1883 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1884 goto out;
1885 i++;
1886 filp->f_pos++;
1887 /* fall through */
1888 default:
1889 i -= 2;
1890 if (i >= nents) {
1891 ret = 1;
1892 goto out;
1893 }
1894 p = ents + i;
1895 last = &ents[nents - 1];
1896 while (p <= last) {
1897 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1898 goto out;
1899 filp->f_pos++;
1900 p++;
1901 }
1902 }
1903
1904 ret = 1;
1905 out:
1906 put_task_struct(task);
1907 out_no_task:
1908 return ret;
1909 }
1910
1911 #ifdef CONFIG_SECURITY
1912 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1913 size_t count, loff_t *ppos)
1914 {
1915 struct inode * inode = file->f_path.dentry->d_inode;
1916 char *p = NULL;
1917 ssize_t length;
1918 struct task_struct *task = get_proc_task(inode);
1919
1920 if (!task)
1921 return -ESRCH;
1922
1923 length = security_getprocattr(task,
1924 (char*)file->f_path.dentry->d_name.name,
1925 &p);
1926 put_task_struct(task);
1927 if (length > 0)
1928 length = simple_read_from_buffer(buf, count, ppos, p, length);
1929 kfree(p);
1930 return length;
1931 }
1932
1933 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1934 size_t count, loff_t *ppos)
1935 {
1936 struct inode * inode = file->f_path.dentry->d_inode;
1937 char *page;
1938 ssize_t length;
1939 struct task_struct *task = get_proc_task(inode);
1940
1941 length = -ESRCH;
1942 if (!task)
1943 goto out_no_task;
1944 if (count > PAGE_SIZE)
1945 count = PAGE_SIZE;
1946
1947 /* No partial writes. */
1948 length = -EINVAL;
1949 if (*ppos != 0)
1950 goto out;
1951
1952 length = -ENOMEM;
1953 page = (char*)__get_free_page(GFP_TEMPORARY);
1954 if (!page)
1955 goto out;
1956
1957 length = -EFAULT;
1958 if (copy_from_user(page, buf, count))
1959 goto out_free;
1960
1961 length = security_setprocattr(task,
1962 (char*)file->f_path.dentry->d_name.name,
1963 (void*)page, count);
1964 out_free:
1965 free_page((unsigned long) page);
1966 out:
1967 put_task_struct(task);
1968 out_no_task:
1969 return length;
1970 }
1971
1972 static const struct file_operations proc_pid_attr_operations = {
1973 .read = proc_pid_attr_read,
1974 .write = proc_pid_attr_write,
1975 };
1976
1977 static const struct pid_entry attr_dir_stuff[] = {
1978 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1979 REG("prev", S_IRUGO, pid_attr),
1980 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1981 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1982 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1983 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1984 };
1985
1986 static int proc_attr_dir_readdir(struct file * filp,
1987 void * dirent, filldir_t filldir)
1988 {
1989 return proc_pident_readdir(filp,dirent,filldir,
1990 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1991 }
1992
1993 static const struct file_operations proc_attr_dir_operations = {
1994 .read = generic_read_dir,
1995 .readdir = proc_attr_dir_readdir,
1996 };
1997
1998 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
1999 struct dentry *dentry, struct nameidata *nd)
2000 {
2001 return proc_pident_lookup(dir, dentry,
2002 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2003 }
2004
2005 static const struct inode_operations proc_attr_dir_inode_operations = {
2006 .lookup = proc_attr_dir_lookup,
2007 .getattr = pid_getattr,
2008 .setattr = proc_setattr,
2009 };
2010
2011 #endif
2012
2013 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2014 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2015 size_t count, loff_t *ppos)
2016 {
2017 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2018 struct mm_struct *mm;
2019 char buffer[PROC_NUMBUF];
2020 size_t len;
2021 int ret;
2022
2023 if (!task)
2024 return -ESRCH;
2025
2026 ret = 0;
2027 mm = get_task_mm(task);
2028 if (mm) {
2029 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2030 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2031 MMF_DUMP_FILTER_SHIFT));
2032 mmput(mm);
2033 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2034 }
2035
2036 put_task_struct(task);
2037
2038 return ret;
2039 }
2040
2041 static ssize_t proc_coredump_filter_write(struct file *file,
2042 const char __user *buf,
2043 size_t count,
2044 loff_t *ppos)
2045 {
2046 struct task_struct *task;
2047 struct mm_struct *mm;
2048 char buffer[PROC_NUMBUF], *end;
2049 unsigned int val;
2050 int ret;
2051 int i;
2052 unsigned long mask;
2053
2054 ret = -EFAULT;
2055 memset(buffer, 0, sizeof(buffer));
2056 if (count > sizeof(buffer) - 1)
2057 count = sizeof(buffer) - 1;
2058 if (copy_from_user(buffer, buf, count))
2059 goto out_no_task;
2060
2061 ret = -EINVAL;
2062 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2063 if (*end == '\n')
2064 end++;
2065 if (end - buffer == 0)
2066 goto out_no_task;
2067
2068 ret = -ESRCH;
2069 task = get_proc_task(file->f_dentry->d_inode);
2070 if (!task)
2071 goto out_no_task;
2072
2073 ret = end - buffer;
2074 mm = get_task_mm(task);
2075 if (!mm)
2076 goto out_no_mm;
2077
2078 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2079 if (val & mask)
2080 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2081 else
2082 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2083 }
2084
2085 mmput(mm);
2086 out_no_mm:
2087 put_task_struct(task);
2088 out_no_task:
2089 return ret;
2090 }
2091
2092 static const struct file_operations proc_coredump_filter_operations = {
2093 .read = proc_coredump_filter_read,
2094 .write = proc_coredump_filter_write,
2095 };
2096 #endif
2097
2098 /*
2099 * /proc/self:
2100 */
2101 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2102 int buflen)
2103 {
2104 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2105 pid_t pid = task_pid_nr_ns(current, ns);
2106 char tmp[PROC_NUMBUF];
2107 if (!pid)
2108 return -ENOENT;
2109 sprintf(tmp, "%d", pid);
2110 return vfs_readlink(dentry,buffer,buflen,tmp);
2111 }
2112
2113 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2114 {
2115 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2116 pid_t pid = task_pid_nr_ns(current, ns);
2117 char tmp[PROC_NUMBUF];
2118 if (!pid)
2119 return ERR_PTR(-ENOENT);
2120 sprintf(tmp, "%d", pid);
2121 return ERR_PTR(vfs_follow_link(nd,tmp));
2122 }
2123
2124 static const struct inode_operations proc_self_inode_operations = {
2125 .readlink = proc_self_readlink,
2126 .follow_link = proc_self_follow_link,
2127 };
2128
2129 /*
2130 * proc base
2131 *
2132 * These are the directory entries in the root directory of /proc
2133 * that properly belong to the /proc filesystem, as they describe
2134 * describe something that is process related.
2135 */
2136 static const struct pid_entry proc_base_stuff[] = {
2137 NOD("self", S_IFLNK|S_IRWXUGO,
2138 &proc_self_inode_operations, NULL, {}),
2139 };
2140
2141 /*
2142 * Exceptional case: normally we are not allowed to unhash a busy
2143 * directory. In this case, however, we can do it - no aliasing problems
2144 * due to the way we treat inodes.
2145 */
2146 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2147 {
2148 struct inode *inode = dentry->d_inode;
2149 struct task_struct *task = get_proc_task(inode);
2150 if (task) {
2151 put_task_struct(task);
2152 return 1;
2153 }
2154 d_drop(dentry);
2155 return 0;
2156 }
2157
2158 static struct dentry_operations proc_base_dentry_operations =
2159 {
2160 .d_revalidate = proc_base_revalidate,
2161 .d_delete = pid_delete_dentry,
2162 };
2163
2164 static struct dentry *proc_base_instantiate(struct inode *dir,
2165 struct dentry *dentry, struct task_struct *task, const void *ptr)
2166 {
2167 const struct pid_entry *p = ptr;
2168 struct inode *inode;
2169 struct proc_inode *ei;
2170 struct dentry *error = ERR_PTR(-EINVAL);
2171
2172 /* Allocate the inode */
2173 error = ERR_PTR(-ENOMEM);
2174 inode = new_inode(dir->i_sb);
2175 if (!inode)
2176 goto out;
2177
2178 /* Initialize the inode */
2179 ei = PROC_I(inode);
2180 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2181
2182 /*
2183 * grab the reference to the task.
2184 */
2185 ei->pid = get_task_pid(task, PIDTYPE_PID);
2186 if (!ei->pid)
2187 goto out_iput;
2188
2189 inode->i_uid = 0;
2190 inode->i_gid = 0;
2191 inode->i_mode = p->mode;
2192 if (S_ISDIR(inode->i_mode))
2193 inode->i_nlink = 2;
2194 if (S_ISLNK(inode->i_mode))
2195 inode->i_size = 64;
2196 if (p->iop)
2197 inode->i_op = p->iop;
2198 if (p->fop)
2199 inode->i_fop = p->fop;
2200 ei->op = p->op;
2201 dentry->d_op = &proc_base_dentry_operations;
2202 d_add(dentry, inode);
2203 error = NULL;
2204 out:
2205 return error;
2206 out_iput:
2207 iput(inode);
2208 goto out;
2209 }
2210
2211 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2212 {
2213 struct dentry *error;
2214 struct task_struct *task = get_proc_task(dir);
2215 const struct pid_entry *p, *last;
2216
2217 error = ERR_PTR(-ENOENT);
2218
2219 if (!task)
2220 goto out_no_task;
2221
2222 /* Lookup the directory entry */
2223 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2224 for (p = proc_base_stuff; p <= last; p++) {
2225 if (p->len != dentry->d_name.len)
2226 continue;
2227 if (!memcmp(dentry->d_name.name, p->name, p->len))
2228 break;
2229 }
2230 if (p > last)
2231 goto out;
2232
2233 error = proc_base_instantiate(dir, dentry, task, p);
2234
2235 out:
2236 put_task_struct(task);
2237 out_no_task:
2238 return error;
2239 }
2240
2241 static int proc_base_fill_cache(struct file *filp, void *dirent,
2242 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2243 {
2244 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2245 proc_base_instantiate, task, p);
2246 }
2247
2248 #ifdef CONFIG_TASK_IO_ACCOUNTING
2249 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2250 {
2251 return sprintf(buffer,
2252 #ifdef CONFIG_TASK_XACCT
2253 "rchar: %llu\n"
2254 "wchar: %llu\n"
2255 "syscr: %llu\n"
2256 "syscw: %llu\n"
2257 #endif
2258 "read_bytes: %llu\n"
2259 "write_bytes: %llu\n"
2260 "cancelled_write_bytes: %llu\n",
2261 #ifdef CONFIG_TASK_XACCT
2262 (unsigned long long)task->rchar,
2263 (unsigned long long)task->wchar,
2264 (unsigned long long)task->syscr,
2265 (unsigned long long)task->syscw,
2266 #endif
2267 (unsigned long long)task->ioac.read_bytes,
2268 (unsigned long long)task->ioac.write_bytes,
2269 (unsigned long long)task->ioac.cancelled_write_bytes);
2270 }
2271 #endif
2272
2273 /*
2274 * Thread groups
2275 */
2276 static const struct file_operations proc_task_operations;
2277 static const struct inode_operations proc_task_inode_operations;
2278
2279 static const struct pid_entry tgid_base_stuff[] = {
2280 DIR("task", S_IRUGO|S_IXUGO, task),
2281 DIR("fd", S_IRUSR|S_IXUSR, fd),
2282 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2283 REG("environ", S_IRUSR, environ),
2284 INF("auxv", S_IRUSR, pid_auxv),
2285 ONE("status", S_IRUGO, pid_status),
2286 INF("limits", S_IRUSR, pid_limits),
2287 #ifdef CONFIG_SCHED_DEBUG
2288 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2289 #endif
2290 INF("cmdline", S_IRUGO, pid_cmdline),
2291 ONE("stat", S_IRUGO, tgid_stat),
2292 ONE("statm", S_IRUGO, pid_statm),
2293 REG("maps", S_IRUGO, maps),
2294 #ifdef CONFIG_NUMA
2295 REG("numa_maps", S_IRUGO, numa_maps),
2296 #endif
2297 REG("mem", S_IRUSR|S_IWUSR, mem),
2298 LNK("cwd", cwd),
2299 LNK("root", root),
2300 LNK("exe", exe),
2301 REG("mounts", S_IRUGO, mounts),
2302 REG("mountstats", S_IRUSR, mountstats),
2303 #ifdef CONFIG_PROC_PAGE_MONITOR
2304 REG("clear_refs", S_IWUSR, clear_refs),
2305 REG("smaps", S_IRUGO, smaps),
2306 REG("pagemap", S_IRUSR, pagemap),
2307 #endif
2308 #ifdef CONFIG_SECURITY
2309 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2310 #endif
2311 #ifdef CONFIG_KALLSYMS
2312 INF("wchan", S_IRUGO, pid_wchan),
2313 #endif
2314 #ifdef CONFIG_SCHEDSTATS
2315 INF("schedstat", S_IRUGO, pid_schedstat),
2316 #endif
2317 #ifdef CONFIG_LATENCYTOP
2318 REG("latency", S_IRUGO, lstats),
2319 #endif
2320 #ifdef CONFIG_PROC_PID_CPUSET
2321 REG("cpuset", S_IRUGO, cpuset),
2322 #endif
2323 #ifdef CONFIG_CGROUPS
2324 REG("cgroup", S_IRUGO, cgroup),
2325 #endif
2326 INF("oom_score", S_IRUGO, oom_score),
2327 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2328 #ifdef CONFIG_AUDITSYSCALL
2329 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2330 #endif
2331 #ifdef CONFIG_FAULT_INJECTION
2332 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2333 #endif
2334 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2335 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2336 #endif
2337 #ifdef CONFIG_TASK_IO_ACCOUNTING
2338 INF("io", S_IRUGO, pid_io_accounting),
2339 #endif
2340 };
2341
2342 static int proc_tgid_base_readdir(struct file * filp,
2343 void * dirent, filldir_t filldir)
2344 {
2345 return proc_pident_readdir(filp,dirent,filldir,
2346 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2347 }
2348
2349 static const struct file_operations proc_tgid_base_operations = {
2350 .read = generic_read_dir,
2351 .readdir = proc_tgid_base_readdir,
2352 };
2353
2354 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2355 return proc_pident_lookup(dir, dentry,
2356 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2357 }
2358
2359 static const struct inode_operations proc_tgid_base_inode_operations = {
2360 .lookup = proc_tgid_base_lookup,
2361 .getattr = pid_getattr,
2362 .setattr = proc_setattr,
2363 };
2364
2365 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2366 {
2367 struct dentry *dentry, *leader, *dir;
2368 char buf[PROC_NUMBUF];
2369 struct qstr name;
2370
2371 name.name = buf;
2372 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2373 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2374 if (dentry) {
2375 if (!(current->flags & PF_EXITING))
2376 shrink_dcache_parent(dentry);
2377 d_drop(dentry);
2378 dput(dentry);
2379 }
2380
2381 if (tgid == 0)
2382 goto out;
2383
2384 name.name = buf;
2385 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2386 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2387 if (!leader)
2388 goto out;
2389
2390 name.name = "task";
2391 name.len = strlen(name.name);
2392 dir = d_hash_and_lookup(leader, &name);
2393 if (!dir)
2394 goto out_put_leader;
2395
2396 name.name = buf;
2397 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2398 dentry = d_hash_and_lookup(dir, &name);
2399 if (dentry) {
2400 shrink_dcache_parent(dentry);
2401 d_drop(dentry);
2402 dput(dentry);
2403 }
2404
2405 dput(dir);
2406 out_put_leader:
2407 dput(leader);
2408 out:
2409 return;
2410 }
2411
2412 /**
2413 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2414 * @task: task that should be flushed.
2415 *
2416 * When flushing dentries from proc, one needs to flush them from global
2417 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2418 * in. This call is supposed to do all of this job.
2419 *
2420 * Looks in the dcache for
2421 * /proc/@pid
2422 * /proc/@tgid/task/@pid
2423 * if either directory is present flushes it and all of it'ts children
2424 * from the dcache.
2425 *
2426 * It is safe and reasonable to cache /proc entries for a task until
2427 * that task exits. After that they just clog up the dcache with
2428 * useless entries, possibly causing useful dcache entries to be
2429 * flushed instead. This routine is proved to flush those useless
2430 * dcache entries at process exit time.
2431 *
2432 * NOTE: This routine is just an optimization so it does not guarantee
2433 * that no dcache entries will exist at process exit time it
2434 * just makes it very unlikely that any will persist.
2435 */
2436
2437 void proc_flush_task(struct task_struct *task)
2438 {
2439 int i;
2440 struct pid *pid, *tgid = NULL;
2441 struct upid *upid;
2442
2443 pid = task_pid(task);
2444 if (thread_group_leader(task))
2445 tgid = task_tgid(task);
2446
2447 for (i = 0; i <= pid->level; i++) {
2448 upid = &pid->numbers[i];
2449 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2450 tgid ? tgid->numbers[i].nr : 0);
2451 }
2452
2453 upid = &pid->numbers[pid->level];
2454 if (upid->nr == 1)
2455 pid_ns_release_proc(upid->ns);
2456 }
2457
2458 static struct dentry *proc_pid_instantiate(struct inode *dir,
2459 struct dentry * dentry,
2460 struct task_struct *task, const void *ptr)
2461 {
2462 struct dentry *error = ERR_PTR(-ENOENT);
2463 struct inode *inode;
2464
2465 inode = proc_pid_make_inode(dir->i_sb, task);
2466 if (!inode)
2467 goto out;
2468
2469 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2470 inode->i_op = &proc_tgid_base_inode_operations;
2471 inode->i_fop = &proc_tgid_base_operations;
2472 inode->i_flags|=S_IMMUTABLE;
2473 inode->i_nlink = 5;
2474 #ifdef CONFIG_SECURITY
2475 inode->i_nlink += 1;
2476 #endif
2477
2478 dentry->d_op = &pid_dentry_operations;
2479
2480 d_add(dentry, inode);
2481 /* Close the race of the process dying before we return the dentry */
2482 if (pid_revalidate(dentry, NULL))
2483 error = NULL;
2484 out:
2485 return error;
2486 }
2487
2488 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2489 {
2490 struct dentry *result = ERR_PTR(-ENOENT);
2491 struct task_struct *task;
2492 unsigned tgid;
2493 struct pid_namespace *ns;
2494
2495 result = proc_base_lookup(dir, dentry);
2496 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2497 goto out;
2498
2499 tgid = name_to_int(dentry);
2500 if (tgid == ~0U)
2501 goto out;
2502
2503 ns = dentry->d_sb->s_fs_info;
2504 rcu_read_lock();
2505 task = find_task_by_pid_ns(tgid, ns);
2506 if (task)
2507 get_task_struct(task);
2508 rcu_read_unlock();
2509 if (!task)
2510 goto out;
2511
2512 result = proc_pid_instantiate(dir, dentry, task, NULL);
2513 put_task_struct(task);
2514 out:
2515 return result;
2516 }
2517
2518 /*
2519 * Find the first task with tgid >= tgid
2520 *
2521 */
2522 struct tgid_iter {
2523 unsigned int tgid;
2524 struct task_struct *task;
2525 };
2526 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2527 {
2528 struct pid *pid;
2529
2530 if (iter.task)
2531 put_task_struct(iter.task);
2532 rcu_read_lock();
2533 retry:
2534 iter.task = NULL;
2535 pid = find_ge_pid(iter.tgid, ns);
2536 if (pid) {
2537 iter.tgid = pid_nr_ns(pid, ns);
2538 iter.task = pid_task(pid, PIDTYPE_PID);
2539 /* What we to know is if the pid we have find is the
2540 * pid of a thread_group_leader. Testing for task
2541 * being a thread_group_leader is the obvious thing
2542 * todo but there is a window when it fails, due to
2543 * the pid transfer logic in de_thread.
2544 *
2545 * So we perform the straight forward test of seeing
2546 * if the pid we have found is the pid of a thread
2547 * group leader, and don't worry if the task we have
2548 * found doesn't happen to be a thread group leader.
2549 * As we don't care in the case of readdir.
2550 */
2551 if (!iter.task || !has_group_leader_pid(iter.task)) {
2552 iter.tgid += 1;
2553 goto retry;
2554 }
2555 get_task_struct(iter.task);
2556 }
2557 rcu_read_unlock();
2558 return iter;
2559 }
2560
2561 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2562
2563 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2564 struct tgid_iter iter)
2565 {
2566 char name[PROC_NUMBUF];
2567 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2568 return proc_fill_cache(filp, dirent, filldir, name, len,
2569 proc_pid_instantiate, iter.task, NULL);
2570 }
2571
2572 /* for the /proc/ directory itself, after non-process stuff has been done */
2573 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2574 {
2575 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2576 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2577 struct tgid_iter iter;
2578 struct pid_namespace *ns;
2579
2580 if (!reaper)
2581 goto out_no_task;
2582
2583 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2584 const struct pid_entry *p = &proc_base_stuff[nr];
2585 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2586 goto out;
2587 }
2588
2589 ns = filp->f_dentry->d_sb->s_fs_info;
2590 iter.task = NULL;
2591 iter.tgid = filp->f_pos - TGID_OFFSET;
2592 for (iter = next_tgid(ns, iter);
2593 iter.task;
2594 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2595 filp->f_pos = iter.tgid + TGID_OFFSET;
2596 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2597 put_task_struct(iter.task);
2598 goto out;
2599 }
2600 }
2601 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2602 out:
2603 put_task_struct(reaper);
2604 out_no_task:
2605 return 0;
2606 }
2607
2608 /*
2609 * Tasks
2610 */
2611 static const struct pid_entry tid_base_stuff[] = {
2612 DIR("fd", S_IRUSR|S_IXUSR, fd),
2613 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2614 REG("environ", S_IRUSR, environ),
2615 INF("auxv", S_IRUSR, pid_auxv),
2616 ONE("status", S_IRUGO, pid_status),
2617 INF("limits", S_IRUSR, pid_limits),
2618 #ifdef CONFIG_SCHED_DEBUG
2619 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2620 #endif
2621 INF("cmdline", S_IRUGO, pid_cmdline),
2622 ONE("stat", S_IRUGO, tid_stat),
2623 ONE("statm", S_IRUGO, pid_statm),
2624 REG("maps", S_IRUGO, maps),
2625 #ifdef CONFIG_NUMA
2626 REG("numa_maps", S_IRUGO, numa_maps),
2627 #endif
2628 REG("mem", S_IRUSR|S_IWUSR, mem),
2629 LNK("cwd", cwd),
2630 LNK("root", root),
2631 LNK("exe", exe),
2632 REG("mounts", S_IRUGO, mounts),
2633 #ifdef CONFIG_PROC_PAGE_MONITOR
2634 REG("clear_refs", S_IWUSR, clear_refs),
2635 REG("smaps", S_IRUGO, smaps),
2636 REG("pagemap", S_IRUSR, pagemap),
2637 #endif
2638 #ifdef CONFIG_SECURITY
2639 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2640 #endif
2641 #ifdef CONFIG_KALLSYMS
2642 INF("wchan", S_IRUGO, pid_wchan),
2643 #endif
2644 #ifdef CONFIG_SCHEDSTATS
2645 INF("schedstat", S_IRUGO, pid_schedstat),
2646 #endif
2647 #ifdef CONFIG_LATENCYTOP
2648 REG("latency", S_IRUGO, lstats),
2649 #endif
2650 #ifdef CONFIG_PROC_PID_CPUSET
2651 REG("cpuset", S_IRUGO, cpuset),
2652 #endif
2653 #ifdef CONFIG_CGROUPS
2654 REG("cgroup", S_IRUGO, cgroup),
2655 #endif
2656 INF("oom_score", S_IRUGO, oom_score),
2657 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2658 #ifdef CONFIG_AUDITSYSCALL
2659 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2660 #endif
2661 #ifdef CONFIG_FAULT_INJECTION
2662 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2663 #endif
2664 };
2665
2666 static int proc_tid_base_readdir(struct file * filp,
2667 void * dirent, filldir_t filldir)
2668 {
2669 return proc_pident_readdir(filp,dirent,filldir,
2670 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2671 }
2672
2673 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2674 return proc_pident_lookup(dir, dentry,
2675 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2676 }
2677
2678 static const struct file_operations proc_tid_base_operations = {
2679 .read = generic_read_dir,
2680 .readdir = proc_tid_base_readdir,
2681 };
2682
2683 static const struct inode_operations proc_tid_base_inode_operations = {
2684 .lookup = proc_tid_base_lookup,
2685 .getattr = pid_getattr,
2686 .setattr = proc_setattr,
2687 };
2688
2689 static struct dentry *proc_task_instantiate(struct inode *dir,
2690 struct dentry *dentry, struct task_struct *task, const void *ptr)
2691 {
2692 struct dentry *error = ERR_PTR(-ENOENT);
2693 struct inode *inode;
2694 inode = proc_pid_make_inode(dir->i_sb, task);
2695
2696 if (!inode)
2697 goto out;
2698 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2699 inode->i_op = &proc_tid_base_inode_operations;
2700 inode->i_fop = &proc_tid_base_operations;
2701 inode->i_flags|=S_IMMUTABLE;
2702 inode->i_nlink = 4;
2703 #ifdef CONFIG_SECURITY
2704 inode->i_nlink += 1;
2705 #endif
2706
2707 dentry->d_op = &pid_dentry_operations;
2708
2709 d_add(dentry, inode);
2710 /* Close the race of the process dying before we return the dentry */
2711 if (pid_revalidate(dentry, NULL))
2712 error = NULL;
2713 out:
2714 return error;
2715 }
2716
2717 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2718 {
2719 struct dentry *result = ERR_PTR(-ENOENT);
2720 struct task_struct *task;
2721 struct task_struct *leader = get_proc_task(dir);
2722 unsigned tid;
2723 struct pid_namespace *ns;
2724
2725 if (!leader)
2726 goto out_no_task;
2727
2728 tid = name_to_int(dentry);
2729 if (tid == ~0U)
2730 goto out;
2731
2732 ns = dentry->d_sb->s_fs_info;
2733 rcu_read_lock();
2734 task = find_task_by_pid_ns(tid, ns);
2735 if (task)
2736 get_task_struct(task);
2737 rcu_read_unlock();
2738 if (!task)
2739 goto out;
2740 if (!same_thread_group(leader, task))
2741 goto out_drop_task;
2742
2743 result = proc_task_instantiate(dir, dentry, task, NULL);
2744 out_drop_task:
2745 put_task_struct(task);
2746 out:
2747 put_task_struct(leader);
2748 out_no_task:
2749 return result;
2750 }
2751
2752 /*
2753 * Find the first tid of a thread group to return to user space.
2754 *
2755 * Usually this is just the thread group leader, but if the users
2756 * buffer was too small or there was a seek into the middle of the
2757 * directory we have more work todo.
2758 *
2759 * In the case of a short read we start with find_task_by_pid.
2760 *
2761 * In the case of a seek we start with the leader and walk nr
2762 * threads past it.
2763 */
2764 static struct task_struct *first_tid(struct task_struct *leader,
2765 int tid, int nr, struct pid_namespace *ns)
2766 {
2767 struct task_struct *pos;
2768
2769 rcu_read_lock();
2770 /* Attempt to start with the pid of a thread */
2771 if (tid && (nr > 0)) {
2772 pos = find_task_by_pid_ns(tid, ns);
2773 if (pos && (pos->group_leader == leader))
2774 goto found;
2775 }
2776
2777 /* If nr exceeds the number of threads there is nothing todo */
2778 pos = NULL;
2779 if (nr && nr >= get_nr_threads(leader))
2780 goto out;
2781
2782 /* If we haven't found our starting place yet start
2783 * with the leader and walk nr threads forward.
2784 */
2785 for (pos = leader; nr > 0; --nr) {
2786 pos = next_thread(pos);
2787 if (pos == leader) {
2788 pos = NULL;
2789 goto out;
2790 }
2791 }
2792 found:
2793 get_task_struct(pos);
2794 out:
2795 rcu_read_unlock();
2796 return pos;
2797 }
2798
2799 /*
2800 * Find the next thread in the thread list.
2801 * Return NULL if there is an error or no next thread.
2802 *
2803 * The reference to the input task_struct is released.
2804 */
2805 static struct task_struct *next_tid(struct task_struct *start)
2806 {
2807 struct task_struct *pos = NULL;
2808 rcu_read_lock();
2809 if (pid_alive(start)) {
2810 pos = next_thread(start);
2811 if (thread_group_leader(pos))
2812 pos = NULL;
2813 else
2814 get_task_struct(pos);
2815 }
2816 rcu_read_unlock();
2817 put_task_struct(start);
2818 return pos;
2819 }
2820
2821 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2822 struct task_struct *task, int tid)
2823 {
2824 char name[PROC_NUMBUF];
2825 int len = snprintf(name, sizeof(name), "%d", tid);
2826 return proc_fill_cache(filp, dirent, filldir, name, len,
2827 proc_task_instantiate, task, NULL);
2828 }
2829
2830 /* for the /proc/TGID/task/ directories */
2831 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2832 {
2833 struct dentry *dentry = filp->f_path.dentry;
2834 struct inode *inode = dentry->d_inode;
2835 struct task_struct *leader = NULL;
2836 struct task_struct *task;
2837 int retval = -ENOENT;
2838 ino_t ino;
2839 int tid;
2840 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2841 struct pid_namespace *ns;
2842
2843 task = get_proc_task(inode);
2844 if (!task)
2845 goto out_no_task;
2846 rcu_read_lock();
2847 if (pid_alive(task)) {
2848 leader = task->group_leader;
2849 get_task_struct(leader);
2850 }
2851 rcu_read_unlock();
2852 put_task_struct(task);
2853 if (!leader)
2854 goto out_no_task;
2855 retval = 0;
2856
2857 switch (pos) {
2858 case 0:
2859 ino = inode->i_ino;
2860 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2861 goto out;
2862 pos++;
2863 /* fall through */
2864 case 1:
2865 ino = parent_ino(dentry);
2866 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2867 goto out;
2868 pos++;
2869 /* fall through */
2870 }
2871
2872 /* f_version caches the tgid value that the last readdir call couldn't
2873 * return. lseek aka telldir automagically resets f_version to 0.
2874 */
2875 ns = filp->f_dentry->d_sb->s_fs_info;
2876 tid = (int)filp->f_version;
2877 filp->f_version = 0;
2878 for (task = first_tid(leader, tid, pos - 2, ns);
2879 task;
2880 task = next_tid(task), pos++) {
2881 tid = task_pid_nr_ns(task, ns);
2882 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2883 /* returning this tgid failed, save it as the first
2884 * pid for the next readir call */
2885 filp->f_version = (u64)tid;
2886 put_task_struct(task);
2887 break;
2888 }
2889 }
2890 out:
2891 filp->f_pos = pos;
2892 put_task_struct(leader);
2893 out_no_task:
2894 return retval;
2895 }
2896
2897 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2898 {
2899 struct inode *inode = dentry->d_inode;
2900 struct task_struct *p = get_proc_task(inode);
2901 generic_fillattr(inode, stat);
2902
2903 if (p) {
2904 rcu_read_lock();
2905 stat->nlink += get_nr_threads(p);
2906 rcu_read_unlock();
2907 put_task_struct(p);
2908 }
2909
2910 return 0;
2911 }
2912
2913 static const struct inode_operations proc_task_inode_operations = {
2914 .lookup = proc_task_lookup,
2915 .getattr = proc_task_getattr,
2916 .setattr = proc_setattr,
2917 };
2918
2919 static const struct file_operations proc_task_operations = {
2920 .read = generic_read_dir,
2921 .readdir = proc_task_readdir,
2922 };
Linux kernel - Deliverables
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