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Introduce path_put()
[linux-2.6/verdex.git] / fs / proc / base.c
blobc742be48348f9c211969ca09153b43b5471b8138
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_put(&nd->path);
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->path.dentry,
1174 &nd->path.mnt);
1175 nd->last_type = LAST_BIND;
1176 out:
1177 return ERR_PTR(error);
1178 }
1179
1180 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1181 char __user *buffer, int buflen)
1182 {
1183 struct inode * inode;
1184 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1185 char *path;
1186 int len;
1187
1188 if (!tmp)
1189 return -ENOMEM;
1190
1191 inode = dentry->d_inode;
1192 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1193 len = PTR_ERR(path);
1194 if (IS_ERR(path))
1195 goto out;
1196 len = tmp + PAGE_SIZE - 1 - path;
1197
1198 if (len > buflen)
1199 len = buflen;
1200 if (copy_to_user(buffer, path, len))
1201 len = -EFAULT;
1202 out:
1203 free_page((unsigned long)tmp);
1204 return len;
1205 }
1206
1207 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1208 {
1209 int error = -EACCES;
1210 struct inode *inode = dentry->d_inode;
1211 struct dentry *de;
1212 struct vfsmount *mnt = NULL;
1213
1214 /* Are we allowed to snoop on the tasks file descriptors? */
1215 if (!proc_fd_access_allowed(inode))
1216 goto out;
1217
1218 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1219 if (error)
1220 goto out;
1221
1222 error = do_proc_readlink(de, mnt, buffer, buflen);
1223 dput(de);
1224 mntput(mnt);
1225 out:
1226 return error;
1227 }
1228
1229 static const struct inode_operations proc_pid_link_inode_operations = {
1230 .readlink = proc_pid_readlink,
1231 .follow_link = proc_pid_follow_link,
1232 .setattr = proc_setattr,
1233 };
1234
1235
1236 /* building an inode */
1237
1238 static int task_dumpable(struct task_struct *task)
1239 {
1240 int dumpable = 0;
1241 struct mm_struct *mm;
1242
1243 task_lock(task);
1244 mm = task->mm;
1245 if (mm)
1246 dumpable = get_dumpable(mm);
1247 task_unlock(task);
1248 if(dumpable == 1)
1249 return 1;
1250 return 0;
1251 }
1252
1253
1254 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1255 {
1256 struct inode * inode;
1257 struct proc_inode *ei;
1258
1259 /* We need a new inode */
1260
1261 inode = new_inode(sb);
1262 if (!inode)
1263 goto out;
1264
1265 /* Common stuff */
1266 ei = PROC_I(inode);
1267 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1268 inode->i_op = &proc_def_inode_operations;
1269
1270 /*
1271 * grab the reference to task.
1272 */
1273 ei->pid = get_task_pid(task, PIDTYPE_PID);
1274 if (!ei->pid)
1275 goto out_unlock;
1276
1277 inode->i_uid = 0;
1278 inode->i_gid = 0;
1279 if (task_dumpable(task)) {
1280 inode->i_uid = task->euid;
1281 inode->i_gid = task->egid;
1282 }
1283 security_task_to_inode(task, inode);
1284
1285 out:
1286 return inode;
1287
1288 out_unlock:
1289 iput(inode);
1290 return NULL;
1291 }
1292
1293 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1294 {
1295 struct inode *inode = dentry->d_inode;
1296 struct task_struct *task;
1297 generic_fillattr(inode, stat);
1298
1299 rcu_read_lock();
1300 stat->uid = 0;
1301 stat->gid = 0;
1302 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1303 if (task) {
1304 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1305 task_dumpable(task)) {
1306 stat->uid = task->euid;
1307 stat->gid = task->egid;
1308 }
1309 }
1310 rcu_read_unlock();
1311 return 0;
1312 }
1313
1314 /* dentry stuff */
1315
1316 /*
1317 * Exceptional case: normally we are not allowed to unhash a busy
1318 * directory. In this case, however, we can do it - no aliasing problems
1319 * due to the way we treat inodes.
1320 *
1321 * Rewrite the inode's ownerships here because the owning task may have
1322 * performed a setuid(), etc.
1323 *
1324 * Before the /proc/pid/status file was created the only way to read
1325 * the effective uid of a /process was to stat /proc/pid. Reading
1326 * /proc/pid/status is slow enough that procps and other packages
1327 * kept stating /proc/pid. To keep the rules in /proc simple I have
1328 * made this apply to all per process world readable and executable
1329 * directories.
1330 */
1331 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1332 {
1333 struct inode *inode = dentry->d_inode;
1334 struct task_struct *task = get_proc_task(inode);
1335 if (task) {
1336 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1337 task_dumpable(task)) {
1338 inode->i_uid = task->euid;
1339 inode->i_gid = task->egid;
1340 } else {
1341 inode->i_uid = 0;
1342 inode->i_gid = 0;
1343 }
1344 inode->i_mode &= ~(S_ISUID | S_ISGID);
1345 security_task_to_inode(task, inode);
1346 put_task_struct(task);
1347 return 1;
1348 }
1349 d_drop(dentry);
1350 return 0;
1351 }
1352
1353 static int pid_delete_dentry(struct dentry * dentry)
1354 {
1355 /* Is the task we represent dead?
1356 * If so, then don't put the dentry on the lru list,
1357 * kill it immediately.
1358 */
1359 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1360 }
1361
1362 static struct dentry_operations pid_dentry_operations =
1363 {
1364 .d_revalidate = pid_revalidate,
1365 .d_delete = pid_delete_dentry,
1366 };
1367
1368 /* Lookups */
1369
1370 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1371 struct task_struct *, const void *);
1372
1373 /*
1374 * Fill a directory entry.
1375 *
1376 * If possible create the dcache entry and derive our inode number and
1377 * file type from dcache entry.
1378 *
1379 * Since all of the proc inode numbers are dynamically generated, the inode
1380 * numbers do not exist until the inode is cache. This means creating the
1381 * the dcache entry in readdir is necessary to keep the inode numbers
1382 * reported by readdir in sync with the inode numbers reported
1383 * by stat.
1384 */
1385 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1386 char *name, int len,
1387 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1388 {
1389 struct dentry *child, *dir = filp->f_path.dentry;
1390 struct inode *inode;
1391 struct qstr qname;
1392 ino_t ino = 0;
1393 unsigned type = DT_UNKNOWN;
1394
1395 qname.name = name;
1396 qname.len = len;
1397 qname.hash = full_name_hash(name, len);
1398
1399 child = d_lookup(dir, &qname);
1400 if (!child) {
1401 struct dentry *new;
1402 new = d_alloc(dir, &qname);
1403 if (new) {
1404 child = instantiate(dir->d_inode, new, task, ptr);
1405 if (child)
1406 dput(new);
1407 else
1408 child = new;
1409 }
1410 }
1411 if (!child || IS_ERR(child) || !child->d_inode)
1412 goto end_instantiate;
1413 inode = child->d_inode;
1414 if (inode) {
1415 ino = inode->i_ino;
1416 type = inode->i_mode >> 12;
1417 }
1418 dput(child);
1419 end_instantiate:
1420 if (!ino)
1421 ino = find_inode_number(dir, &qname);
1422 if (!ino)
1423 ino = 1;
1424 return filldir(dirent, name, len, filp->f_pos, ino, type);
1425 }
1426
1427 static unsigned name_to_int(struct dentry *dentry)
1428 {
1429 const char *name = dentry->d_name.name;
1430 int len = dentry->d_name.len;
1431 unsigned n = 0;
1432
1433 if (len > 1 && *name == '0')
1434 goto out;
1435 while (len-- > 0) {
1436 unsigned c = *name++ - '0';
1437 if (c > 9)
1438 goto out;
1439 if (n >= (~0U-9)/10)
1440 goto out;
1441 n *= 10;
1442 n += c;
1443 }
1444 return n;
1445 out:
1446 return ~0U;
1447 }
1448
1449 #define PROC_FDINFO_MAX 64
1450
1451 static int proc_fd_info(struct inode *inode, struct dentry **dentry,
1452 struct vfsmount **mnt, char *info)
1453 {
1454 struct task_struct *task = get_proc_task(inode);
1455 struct files_struct *files = NULL;
1456 struct file *file;
1457 int fd = proc_fd(inode);
1458
1459 if (task) {
1460 files = get_files_struct(task);
1461 put_task_struct(task);
1462 }
1463 if (files) {
1464 /*
1465 * We are not taking a ref to the file structure, so we must
1466 * hold ->file_lock.
1467 */
1468 spin_lock(&files->file_lock);
1469 file = fcheck_files(files, fd);
1470 if (file) {
1471 if (mnt)
1472 *mnt = mntget(file->f_path.mnt);
1473 if (dentry)
1474 *dentry = dget(file->f_path.dentry);
1475 if (info)
1476 snprintf(info, PROC_FDINFO_MAX,
1477 "pos:\t%lli\n"
1478 "flags:\t0%o\n",
1479 (long long) file->f_pos,
1480 file->f_flags);
1481 spin_unlock(&files->file_lock);
1482 put_files_struct(files);
1483 return 0;
1484 }
1485 spin_unlock(&files->file_lock);
1486 put_files_struct(files);
1487 }
1488 return -ENOENT;
1489 }
1490
1491 static int proc_fd_link(struct inode *inode, struct dentry **dentry,
1492 struct vfsmount **mnt)
1493 {
1494 return proc_fd_info(inode, dentry, mnt, NULL);
1495 }
1496
1497 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1498 {
1499 struct inode *inode = dentry->d_inode;
1500 struct task_struct *task = get_proc_task(inode);
1501 int fd = proc_fd(inode);
1502 struct files_struct *files;
1503
1504 if (task) {
1505 files = get_files_struct(task);
1506 if (files) {
1507 rcu_read_lock();
1508 if (fcheck_files(files, fd)) {
1509 rcu_read_unlock();
1510 put_files_struct(files);
1511 if (task_dumpable(task)) {
1512 inode->i_uid = task->euid;
1513 inode->i_gid = task->egid;
1514 } else {
1515 inode->i_uid = 0;
1516 inode->i_gid = 0;
1517 }
1518 inode->i_mode &= ~(S_ISUID | S_ISGID);
1519 security_task_to_inode(task, inode);
1520 put_task_struct(task);
1521 return 1;
1522 }
1523 rcu_read_unlock();
1524 put_files_struct(files);
1525 }
1526 put_task_struct(task);
1527 }
1528 d_drop(dentry);
1529 return 0;
1530 }
1531
1532 static struct dentry_operations tid_fd_dentry_operations =
1533 {
1534 .d_revalidate = tid_fd_revalidate,
1535 .d_delete = pid_delete_dentry,
1536 };
1537
1538 static struct dentry *proc_fd_instantiate(struct inode *dir,
1539 struct dentry *dentry, struct task_struct *task, const void *ptr)
1540 {
1541 unsigned fd = *(const unsigned *)ptr;
1542 struct file *file;
1543 struct files_struct *files;
1544 struct inode *inode;
1545 struct proc_inode *ei;
1546 struct dentry *error = ERR_PTR(-ENOENT);
1547
1548 inode = proc_pid_make_inode(dir->i_sb, task);
1549 if (!inode)
1550 goto out;
1551 ei = PROC_I(inode);
1552 ei->fd = fd;
1553 files = get_files_struct(task);
1554 if (!files)
1555 goto out_iput;
1556 inode->i_mode = S_IFLNK;
1557
1558 /*
1559 * We are not taking a ref to the file structure, so we must
1560 * hold ->file_lock.
1561 */
1562 spin_lock(&files->file_lock);
1563 file = fcheck_files(files, fd);
1564 if (!file)
1565 goto out_unlock;
1566 if (file->f_mode & 1)
1567 inode->i_mode |= S_IRUSR | S_IXUSR;
1568 if (file->f_mode & 2)
1569 inode->i_mode |= S_IWUSR | S_IXUSR;
1570 spin_unlock(&files->file_lock);
1571 put_files_struct(files);
1572
1573 inode->i_op = &proc_pid_link_inode_operations;
1574 inode->i_size = 64;
1575 ei->op.proc_get_link = proc_fd_link;
1576 dentry->d_op = &tid_fd_dentry_operations;
1577 d_add(dentry, inode);
1578 /* Close the race of the process dying before we return the dentry */
1579 if (tid_fd_revalidate(dentry, NULL))
1580 error = NULL;
1581
1582 out:
1583 return error;
1584 out_unlock:
1585 spin_unlock(&files->file_lock);
1586 put_files_struct(files);
1587 out_iput:
1588 iput(inode);
1589 goto out;
1590 }
1591
1592 static struct dentry *proc_lookupfd_common(struct inode *dir,
1593 struct dentry *dentry,
1594 instantiate_t instantiate)
1595 {
1596 struct task_struct *task = get_proc_task(dir);
1597 unsigned fd = name_to_int(dentry);
1598 struct dentry *result = ERR_PTR(-ENOENT);
1599
1600 if (!task)
1601 goto out_no_task;
1602 if (fd == ~0U)
1603 goto out;
1604
1605 result = instantiate(dir, dentry, task, &fd);
1606 out:
1607 put_task_struct(task);
1608 out_no_task:
1609 return result;
1610 }
1611
1612 static int proc_readfd_common(struct file * filp, void * dirent,
1613 filldir_t filldir, instantiate_t instantiate)
1614 {
1615 struct dentry *dentry = filp->f_path.dentry;
1616 struct inode *inode = dentry->d_inode;
1617 struct task_struct *p = get_proc_task(inode);
1618 unsigned int fd, ino;
1619 int retval;
1620 struct files_struct * files;
1621 struct fdtable *fdt;
1622
1623 retval = -ENOENT;
1624 if (!p)
1625 goto out_no_task;
1626 retval = 0;
1627
1628 fd = filp->f_pos;
1629 switch (fd) {
1630 case 0:
1631 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1632 goto out;
1633 filp->f_pos++;
1634 case 1:
1635 ino = parent_ino(dentry);
1636 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1637 goto out;
1638 filp->f_pos++;
1639 default:
1640 files = get_files_struct(p);
1641 if (!files)
1642 goto out;
1643 rcu_read_lock();
1644 fdt = files_fdtable(files);
1645 for (fd = filp->f_pos-2;
1646 fd < fdt->max_fds;
1647 fd++, filp->f_pos++) {
1648 char name[PROC_NUMBUF];
1649 int len;
1650
1651 if (!fcheck_files(files, fd))
1652 continue;
1653 rcu_read_unlock();
1654
1655 len = snprintf(name, sizeof(name), "%d", fd);
1656 if (proc_fill_cache(filp, dirent, filldir,
1657 name, len, instantiate,
1658 p, &fd) < 0) {
1659 rcu_read_lock();
1660 break;
1661 }
1662 rcu_read_lock();
1663 }
1664 rcu_read_unlock();
1665 put_files_struct(files);
1666 }
1667 out:
1668 put_task_struct(p);
1669 out_no_task:
1670 return retval;
1671 }
1672
1673 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1674 struct nameidata *nd)
1675 {
1676 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1677 }
1678
1679 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1680 {
1681 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1682 }
1683
1684 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1685 size_t len, loff_t *ppos)
1686 {
1687 char tmp[PROC_FDINFO_MAX];
1688 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
1689 if (!err)
1690 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1691 return err;
1692 }
1693
1694 static const struct file_operations proc_fdinfo_file_operations = {
1695 .open = nonseekable_open,
1696 .read = proc_fdinfo_read,
1697 };
1698
1699 static const struct file_operations proc_fd_operations = {
1700 .read = generic_read_dir,
1701 .readdir = proc_readfd,
1702 };
1703
1704 /*
1705 * /proc/pid/fd needs a special permission handler so that a process can still
1706 * access /proc/self/fd after it has executed a setuid().
1707 */
1708 static int proc_fd_permission(struct inode *inode, int mask,
1709 struct nameidata *nd)
1710 {
1711 int rv;
1712
1713 rv = generic_permission(inode, mask, NULL);
1714 if (rv == 0)
1715 return 0;
1716 if (task_pid(current) == proc_pid(inode))
1717 rv = 0;
1718 return rv;
1719 }
1720
1721 /*
1722 * proc directories can do almost nothing..
1723 */
1724 static const struct inode_operations proc_fd_inode_operations = {
1725 .lookup = proc_lookupfd,
1726 .permission = proc_fd_permission,
1727 .setattr = proc_setattr,
1728 };
1729
1730 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1731 struct dentry *dentry, struct task_struct *task, const void *ptr)
1732 {
1733 unsigned fd = *(unsigned *)ptr;
1734 struct inode *inode;
1735 struct proc_inode *ei;
1736 struct dentry *error = ERR_PTR(-ENOENT);
1737
1738 inode = proc_pid_make_inode(dir->i_sb, task);
1739 if (!inode)
1740 goto out;
1741 ei = PROC_I(inode);
1742 ei->fd = fd;
1743 inode->i_mode = S_IFREG | S_IRUSR;
1744 inode->i_fop = &proc_fdinfo_file_operations;
1745 dentry->d_op = &tid_fd_dentry_operations;
1746 d_add(dentry, inode);
1747 /* Close the race of the process dying before we return the dentry */
1748 if (tid_fd_revalidate(dentry, NULL))
1749 error = NULL;
1750
1751 out:
1752 return error;
1753 }
1754
1755 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1756 struct dentry *dentry,
1757 struct nameidata *nd)
1758 {
1759 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1760 }
1761
1762 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1763 {
1764 return proc_readfd_common(filp, dirent, filldir,
1765 proc_fdinfo_instantiate);
1766 }
1767
1768 static const struct file_operations proc_fdinfo_operations = {
1769 .read = generic_read_dir,
1770 .readdir = proc_readfdinfo,
1771 };
1772
1773 /*
1774 * proc directories can do almost nothing..
1775 */
1776 static const struct inode_operations proc_fdinfo_inode_operations = {
1777 .lookup = proc_lookupfdinfo,
1778 .setattr = proc_setattr,
1779 };
1780
1781
1782 static struct dentry *proc_pident_instantiate(struct inode *dir,
1783 struct dentry *dentry, struct task_struct *task, const void *ptr)
1784 {
1785 const struct pid_entry *p = ptr;
1786 struct inode *inode;
1787 struct proc_inode *ei;
1788 struct dentry *error = ERR_PTR(-EINVAL);
1789
1790 inode = proc_pid_make_inode(dir->i_sb, task);
1791 if (!inode)
1792 goto out;
1793
1794 ei = PROC_I(inode);
1795 inode->i_mode = p->mode;
1796 if (S_ISDIR(inode->i_mode))
1797 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1798 if (p->iop)
1799 inode->i_op = p->iop;
1800 if (p->fop)
1801 inode->i_fop = p->fop;
1802 ei->op = p->op;
1803 dentry->d_op = &pid_dentry_operations;
1804 d_add(dentry, inode);
1805 /* Close the race of the process dying before we return the dentry */
1806 if (pid_revalidate(dentry, NULL))
1807 error = NULL;
1808 out:
1809 return error;
1810 }
1811
1812 static struct dentry *proc_pident_lookup(struct inode *dir,
1813 struct dentry *dentry,
1814 const struct pid_entry *ents,
1815 unsigned int nents)
1816 {
1817 struct inode *inode;
1818 struct dentry *error;
1819 struct task_struct *task = get_proc_task(dir);
1820 const struct pid_entry *p, *last;
1821
1822 error = ERR_PTR(-ENOENT);
1823 inode = NULL;
1824
1825 if (!task)
1826 goto out_no_task;
1827
1828 /*
1829 * Yes, it does not scale. And it should not. Don't add
1830 * new entries into /proc/<tgid>/ without very good reasons.
1831 */
1832 last = &ents[nents - 1];
1833 for (p = ents; p <= last; p++) {
1834 if (p->len != dentry->d_name.len)
1835 continue;
1836 if (!memcmp(dentry->d_name.name, p->name, p->len))
1837 break;
1838 }
1839 if (p > last)
1840 goto out;
1841
1842 error = proc_pident_instantiate(dir, dentry, task, p);
1843 out:
1844 put_task_struct(task);
1845 out_no_task:
1846 return error;
1847 }
1848
1849 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1850 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1851 {
1852 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1853 proc_pident_instantiate, task, p);
1854 }
1855
1856 static int proc_pident_readdir(struct file *filp,
1857 void *dirent, filldir_t filldir,
1858 const struct pid_entry *ents, unsigned int nents)
1859 {
1860 int i;
1861 struct dentry *dentry = filp->f_path.dentry;
1862 struct inode *inode = dentry->d_inode;
1863 struct task_struct *task = get_proc_task(inode);
1864 const struct pid_entry *p, *last;
1865 ino_t ino;
1866 int ret;
1867
1868 ret = -ENOENT;
1869 if (!task)
1870 goto out_no_task;
1871
1872 ret = 0;
1873 i = filp->f_pos;
1874 switch (i) {
1875 case 0:
1876 ino = inode->i_ino;
1877 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1878 goto out;
1879 i++;
1880 filp->f_pos++;
1881 /* fall through */
1882 case 1:
1883 ino = parent_ino(dentry);
1884 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1885 goto out;
1886 i++;
1887 filp->f_pos++;
1888 /* fall through */
1889 default:
1890 i -= 2;
1891 if (i >= nents) {
1892 ret = 1;
1893 goto out;
1894 }
1895 p = ents + i;
1896 last = &ents[nents - 1];
1897 while (p <= last) {
1898 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1899 goto out;
1900 filp->f_pos++;
1901 p++;
1902 }
1903 }
1904
1905 ret = 1;
1906 out:
1907 put_task_struct(task);
1908 out_no_task:
1909 return ret;
1910 }
1911
1912 #ifdef CONFIG_SECURITY
1913 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1914 size_t count, loff_t *ppos)
1915 {
1916 struct inode * inode = file->f_path.dentry->d_inode;
1917 char *p = NULL;
1918 ssize_t length;
1919 struct task_struct *task = get_proc_task(inode);
1920
1921 if (!task)
1922 return -ESRCH;
1923
1924 length = security_getprocattr(task,
1925 (char*)file->f_path.dentry->d_name.name,
1926 &p);
1927 put_task_struct(task);
1928 if (length > 0)
1929 length = simple_read_from_buffer(buf, count, ppos, p, length);
1930 kfree(p);
1931 return length;
1932 }
1933
1934 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1935 size_t count, loff_t *ppos)
1936 {
1937 struct inode * inode = file->f_path.dentry->d_inode;
1938 char *page;
1939 ssize_t length;
1940 struct task_struct *task = get_proc_task(inode);
1941
1942 length = -ESRCH;
1943 if (!task)
1944 goto out_no_task;
1945 if (count > PAGE_SIZE)
1946 count = PAGE_SIZE;
1947
1948 /* No partial writes. */
1949 length = -EINVAL;
1950 if (*ppos != 0)
1951 goto out;
1952
1953 length = -ENOMEM;
1954 page = (char*)__get_free_page(GFP_TEMPORARY);
1955 if (!page)
1956 goto out;
1957
1958 length = -EFAULT;
1959 if (copy_from_user(page, buf, count))
1960 goto out_free;
1961
1962 length = security_setprocattr(task,
1963 (char*)file->f_path.dentry->d_name.name,
1964 (void*)page, count);
1965 out_free:
1966 free_page((unsigned long) page);
1967 out:
1968 put_task_struct(task);
1969 out_no_task:
1970 return length;
1971 }
1972
1973 static const struct file_operations proc_pid_attr_operations = {
1974 .read = proc_pid_attr_read,
1975 .write = proc_pid_attr_write,
1976 };
1977
1978 static const struct pid_entry attr_dir_stuff[] = {
1979 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1980 REG("prev", S_IRUGO, pid_attr),
1981 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1982 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1983 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1984 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1985 };
1986
1987 static int proc_attr_dir_readdir(struct file * filp,
1988 void * dirent, filldir_t filldir)
1989 {
1990 return proc_pident_readdir(filp,dirent,filldir,
1991 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1992 }
1993
1994 static const struct file_operations proc_attr_dir_operations = {
1995 .read = generic_read_dir,
1996 .readdir = proc_attr_dir_readdir,
1997 };
1998
1999 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2000 struct dentry *dentry, struct nameidata *nd)
2001 {
2002 return proc_pident_lookup(dir, dentry,
2003 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2004 }
2005
2006 static const struct inode_operations proc_attr_dir_inode_operations = {
2007 .lookup = proc_attr_dir_lookup,
2008 .getattr = pid_getattr,
2009 .setattr = proc_setattr,
2010 };
2011
2012 #endif
2013
2014 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2015 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2016 size_t count, loff_t *ppos)
2017 {
2018 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2019 struct mm_struct *mm;
2020 char buffer[PROC_NUMBUF];
2021 size_t len;
2022 int ret;
2023
2024 if (!task)
2025 return -ESRCH;
2026
2027 ret = 0;
2028 mm = get_task_mm(task);
2029 if (mm) {
2030 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2031 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2032 MMF_DUMP_FILTER_SHIFT));
2033 mmput(mm);
2034 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2035 }
2036
2037 put_task_struct(task);
2038
2039 return ret;
2040 }
2041
2042 static ssize_t proc_coredump_filter_write(struct file *file,
2043 const char __user *buf,
2044 size_t count,
2045 loff_t *ppos)
2046 {
2047 struct task_struct *task;
2048 struct mm_struct *mm;
2049 char buffer[PROC_NUMBUF], *end;
2050 unsigned int val;
2051 int ret;
2052 int i;
2053 unsigned long mask;
2054
2055 ret = -EFAULT;
2056 memset(buffer, 0, sizeof(buffer));
2057 if (count > sizeof(buffer) - 1)
2058 count = sizeof(buffer) - 1;
2059 if (copy_from_user(buffer, buf, count))
2060 goto out_no_task;
2061
2062 ret = -EINVAL;
2063 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2064 if (*end == '\n')
2065 end++;
2066 if (end - buffer == 0)
2067 goto out_no_task;
2068
2069 ret = -ESRCH;
2070 task = get_proc_task(file->f_dentry->d_inode);
2071 if (!task)
2072 goto out_no_task;
2073
2074 ret = end - buffer;
2075 mm = get_task_mm(task);
2076 if (!mm)
2077 goto out_no_mm;
2078
2079 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2080 if (val & mask)
2081 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2082 else
2083 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2084 }
2085
2086 mmput(mm);
2087 out_no_mm:
2088 put_task_struct(task);
2089 out_no_task:
2090 return ret;
2091 }
2092
2093 static const struct file_operations proc_coredump_filter_operations = {
2094 .read = proc_coredump_filter_read,
2095 .write = proc_coredump_filter_write,
2096 };
2097 #endif
2098
2099 /*
2100 * /proc/self:
2101 */
2102 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2103 int buflen)
2104 {
2105 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2106 pid_t tgid = task_tgid_nr_ns(current, ns);
2107 char tmp[PROC_NUMBUF];
2108 if (!tgid)
2109 return -ENOENT;
2110 sprintf(tmp, "%d", tgid);
2111 return vfs_readlink(dentry,buffer,buflen,tmp);
2112 }
2113
2114 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2115 {
2116 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2117 pid_t tgid = task_tgid_nr_ns(current, ns);
2118 char tmp[PROC_NUMBUF];
2119 if (!tgid)
2120 return ERR_PTR(-ENOENT);
2121 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2122 return ERR_PTR(vfs_follow_link(nd,tmp));
2123 }
2124
2125 static const struct inode_operations proc_self_inode_operations = {
2126 .readlink = proc_self_readlink,
2127 .follow_link = proc_self_follow_link,
2128 };
2129
2130 /*
2131 * proc base
2132 *
2133 * These are the directory entries in the root directory of /proc
2134 * that properly belong to the /proc filesystem, as they describe
2135 * describe something that is process related.
2136 */
2137 static const struct pid_entry proc_base_stuff[] = {
2138 NOD("self", S_IFLNK|S_IRWXUGO,
2139 &proc_self_inode_operations, NULL, {}),
2140 };
2141
2142 /*
2143 * Exceptional case: normally we are not allowed to unhash a busy
2144 * directory. In this case, however, we can do it - no aliasing problems
2145 * due to the way we treat inodes.
2146 */
2147 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2148 {
2149 struct inode *inode = dentry->d_inode;
2150 struct task_struct *task = get_proc_task(inode);
2151 if (task) {
2152 put_task_struct(task);
2153 return 1;
2154 }
2155 d_drop(dentry);
2156 return 0;
2157 }
2158
2159 static struct dentry_operations proc_base_dentry_operations =
2160 {
2161 .d_revalidate = proc_base_revalidate,
2162 .d_delete = pid_delete_dentry,
2163 };
2164
2165 static struct dentry *proc_base_instantiate(struct inode *dir,
2166 struct dentry *dentry, struct task_struct *task, const void *ptr)
2167 {
2168 const struct pid_entry *p = ptr;
2169 struct inode *inode;
2170 struct proc_inode *ei;
2171 struct dentry *error = ERR_PTR(-EINVAL);
2172
2173 /* Allocate the inode */
2174 error = ERR_PTR(-ENOMEM);
2175 inode = new_inode(dir->i_sb);
2176 if (!inode)
2177 goto out;
2178
2179 /* Initialize the inode */
2180 ei = PROC_I(inode);
2181 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2182
2183 /*
2184 * grab the reference to the task.
2185 */
2186 ei->pid = get_task_pid(task, PIDTYPE_PID);
2187 if (!ei->pid)
2188 goto out_iput;
2189
2190 inode->i_uid = 0;
2191 inode->i_gid = 0;
2192 inode->i_mode = p->mode;
2193 if (S_ISDIR(inode->i_mode))
2194 inode->i_nlink = 2;
2195 if (S_ISLNK(inode->i_mode))
2196 inode->i_size = 64;
2197 if (p->iop)
2198 inode->i_op = p->iop;
2199 if (p->fop)
2200 inode->i_fop = p->fop;
2201 ei->op = p->op;
2202 dentry->d_op = &proc_base_dentry_operations;
2203 d_add(dentry, inode);
2204 error = NULL;
2205 out:
2206 return error;
2207 out_iput:
2208 iput(inode);
2209 goto out;
2210 }
2211
2212 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2213 {
2214 struct dentry *error;
2215 struct task_struct *task = get_proc_task(dir);
2216 const struct pid_entry *p, *last;
2217
2218 error = ERR_PTR(-ENOENT);
2219
2220 if (!task)
2221 goto out_no_task;
2222
2223 /* Lookup the directory entry */
2224 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2225 for (p = proc_base_stuff; p <= last; p++) {
2226 if (p->len != dentry->d_name.len)
2227 continue;
2228 if (!memcmp(dentry->d_name.name, p->name, p->len))
2229 break;
2230 }
2231 if (p > last)
2232 goto out;
2233
2234 error = proc_base_instantiate(dir, dentry, task, p);
2235
2236 out:
2237 put_task_struct(task);
2238 out_no_task:
2239 return error;
2240 }
2241
2242 static int proc_base_fill_cache(struct file *filp, void *dirent,
2243 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2244 {
2245 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2246 proc_base_instantiate, task, p);
2247 }
2248
2249 #ifdef CONFIG_TASK_IO_ACCOUNTING
2250 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2251 {
2252 return sprintf(buffer,
2253 #ifdef CONFIG_TASK_XACCT
2254 "rchar: %llu\n"
2255 "wchar: %llu\n"
2256 "syscr: %llu\n"
2257 "syscw: %llu\n"
2258 #endif
2259 "read_bytes: %llu\n"
2260 "write_bytes: %llu\n"
2261 "cancelled_write_bytes: %llu\n",
2262 #ifdef CONFIG_TASK_XACCT
2263 (unsigned long long)task->rchar,
2264 (unsigned long long)task->wchar,
2265 (unsigned long long)task->syscr,
2266 (unsigned long long)task->syscw,
2267 #endif
2268 (unsigned long long)task->ioac.read_bytes,
2269 (unsigned long long)task->ioac.write_bytes,
2270 (unsigned long long)task->ioac.cancelled_write_bytes);
2271 }
2272 #endif
2273
2274 /*
2275 * Thread groups
2276 */
2277 static const struct file_operations proc_task_operations;
2278 static const struct inode_operations proc_task_inode_operations;
2279
2280 static const struct pid_entry tgid_base_stuff[] = {
2281 DIR("task", S_IRUGO|S_IXUGO, task),
2282 DIR("fd", S_IRUSR|S_IXUSR, fd),
2283 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2284 REG("environ", S_IRUSR, environ),
2285 INF("auxv", S_IRUSR, pid_auxv),
2286 ONE("status", S_IRUGO, pid_status),
2287 INF("limits", S_IRUSR, pid_limits),
2288 #ifdef CONFIG_SCHED_DEBUG
2289 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2290 #endif
2291 INF("cmdline", S_IRUGO, pid_cmdline),
2292 ONE("stat", S_IRUGO, tgid_stat),
2293 ONE("statm", S_IRUGO, pid_statm),
2294 REG("maps", S_IRUGO, maps),
2295 #ifdef CONFIG_NUMA
2296 REG("numa_maps", S_IRUGO, numa_maps),
2297 #endif
2298 REG("mem", S_IRUSR|S_IWUSR, mem),
2299 LNK("cwd", cwd),
2300 LNK("root", root),
2301 LNK("exe", exe),
2302 REG("mounts", S_IRUGO, mounts),
2303 REG("mountstats", S_IRUSR, mountstats),
2304 #ifdef CONFIG_PROC_PAGE_MONITOR
2305 REG("clear_refs", S_IWUSR, clear_refs),
2306 REG("smaps", S_IRUGO, smaps),
2307 REG("pagemap", S_IRUSR, pagemap),
2308 #endif
2309 #ifdef CONFIG_SECURITY
2310 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2311 #endif
2312 #ifdef CONFIG_KALLSYMS
2313 INF("wchan", S_IRUGO, pid_wchan),
2314 #endif
2315 #ifdef CONFIG_SCHEDSTATS
2316 INF("schedstat", S_IRUGO, pid_schedstat),
2317 #endif
2318 #ifdef CONFIG_LATENCYTOP
2319 REG("latency", S_IRUGO, lstats),
2320 #endif
2321 #ifdef CONFIG_PROC_PID_CPUSET
2322 REG("cpuset", S_IRUGO, cpuset),
2323 #endif
2324 #ifdef CONFIG_CGROUPS
2325 REG("cgroup", S_IRUGO, cgroup),
2326 #endif
2327 INF("oom_score", S_IRUGO, oom_score),
2328 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2329 #ifdef CONFIG_AUDITSYSCALL
2330 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2331 #endif
2332 #ifdef CONFIG_FAULT_INJECTION
2333 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2334 #endif
2335 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2336 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2337 #endif
2338 #ifdef CONFIG_TASK_IO_ACCOUNTING
2339 INF("io", S_IRUGO, pid_io_accounting),
2340 #endif
2341 };
2342
2343 static int proc_tgid_base_readdir(struct file * filp,
2344 void * dirent, filldir_t filldir)
2345 {
2346 return proc_pident_readdir(filp,dirent,filldir,
2347 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2348 }
2349
2350 static const struct file_operations proc_tgid_base_operations = {
2351 .read = generic_read_dir,
2352 .readdir = proc_tgid_base_readdir,
2353 };
2354
2355 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2356 return proc_pident_lookup(dir, dentry,
2357 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2358 }
2359
2360 static const struct inode_operations proc_tgid_base_inode_operations = {
2361 .lookup = proc_tgid_base_lookup,
2362 .getattr = pid_getattr,
2363 .setattr = proc_setattr,
2364 };
2365
2366 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2367 {
2368 struct dentry *dentry, *leader, *dir;
2369 char buf[PROC_NUMBUF];
2370 struct qstr name;
2371
2372 name.name = buf;
2373 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2374 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2375 if (dentry) {
2376 if (!(current->flags & PF_EXITING))
2377 shrink_dcache_parent(dentry);
2378 d_drop(dentry);
2379 dput(dentry);
2380 }
2381
2382 if (tgid == 0)
2383 goto out;
2384
2385 name.name = buf;
2386 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2387 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2388 if (!leader)
2389 goto out;
2390
2391 name.name = "task";
2392 name.len = strlen(name.name);
2393 dir = d_hash_and_lookup(leader, &name);
2394 if (!dir)
2395 goto out_put_leader;
2396
2397 name.name = buf;
2398 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2399 dentry = d_hash_and_lookup(dir, &name);
2400 if (dentry) {
2401 shrink_dcache_parent(dentry);
2402 d_drop(dentry);
2403 dput(dentry);
2404 }
2405
2406 dput(dir);
2407 out_put_leader:
2408 dput(leader);
2409 out:
2410 return;
2411 }
2412
2413 /**
2414 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2415 * @task: task that should be flushed.
2416 *
2417 * When flushing dentries from proc, one needs to flush them from global
2418 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2419 * in. This call is supposed to do all of this job.
2420 *
2421 * Looks in the dcache for
2422 * /proc/@pid
2423 * /proc/@tgid/task/@pid
2424 * if either directory is present flushes it and all of it'ts children
2425 * from the dcache.
2426 *
2427 * It is safe and reasonable to cache /proc entries for a task until
2428 * that task exits. After that they just clog up the dcache with
2429 * useless entries, possibly causing useful dcache entries to be
2430 * flushed instead. This routine is proved to flush those useless
2431 * dcache entries at process exit time.
2432 *
2433 * NOTE: This routine is just an optimization so it does not guarantee
2434 * that no dcache entries will exist at process exit time it
2435 * just makes it very unlikely that any will persist.
2436 */
2437
2438 void proc_flush_task(struct task_struct *task)
2439 {
2440 int i;
2441 struct pid *pid, *tgid = NULL;
2442 struct upid *upid;
2443
2444 pid = task_pid(task);
2445 if (thread_group_leader(task))
2446 tgid = task_tgid(task);
2447
2448 for (i = 0; i <= pid->level; i++) {
2449 upid = &pid->numbers[i];
2450 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2451 tgid ? tgid->numbers[i].nr : 0);
2452 }
2453
2454 upid = &pid->numbers[pid->level];
2455 if (upid->nr == 1)
2456 pid_ns_release_proc(upid->ns);
2457 }
2458
2459 static struct dentry *proc_pid_instantiate(struct inode *dir,
2460 struct dentry * dentry,
2461 struct task_struct *task, const void *ptr)
2462 {
2463 struct dentry *error = ERR_PTR(-ENOENT);
2464 struct inode *inode;
2465
2466 inode = proc_pid_make_inode(dir->i_sb, task);
2467 if (!inode)
2468 goto out;
2469
2470 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2471 inode->i_op = &proc_tgid_base_inode_operations;
2472 inode->i_fop = &proc_tgid_base_operations;
2473 inode->i_flags|=S_IMMUTABLE;
2474 inode->i_nlink = 5;
2475 #ifdef CONFIG_SECURITY
2476 inode->i_nlink += 1;
2477 #endif
2478
2479 dentry->d_op = &pid_dentry_operations;
2480
2481 d_add(dentry, inode);
2482 /* Close the race of the process dying before we return the dentry */
2483 if (pid_revalidate(dentry, NULL))
2484 error = NULL;
2485 out:
2486 return error;
2487 }
2488
2489 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2490 {
2491 struct dentry *result = ERR_PTR(-ENOENT);
2492 struct task_struct *task;
2493 unsigned tgid;
2494 struct pid_namespace *ns;
2495
2496 result = proc_base_lookup(dir, dentry);
2497 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2498 goto out;
2499
2500 tgid = name_to_int(dentry);
2501 if (tgid == ~0U)
2502 goto out;
2503
2504 ns = dentry->d_sb->s_fs_info;
2505 rcu_read_lock();
2506 task = find_task_by_pid_ns(tgid, ns);
2507 if (task)
2508 get_task_struct(task);
2509 rcu_read_unlock();
2510 if (!task)
2511 goto out;
2512
2513 result = proc_pid_instantiate(dir, dentry, task, NULL);
2514 put_task_struct(task);
2515 out:
2516 return result;
2517 }
2518
2519 /*
2520 * Find the first task with tgid >= tgid
2521 *
2522 */
2523 struct tgid_iter {
2524 unsigned int tgid;
2525 struct task_struct *task;
2526 };
2527 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2528 {
2529 struct pid *pid;
2530
2531 if (iter.task)
2532 put_task_struct(iter.task);
2533 rcu_read_lock();
2534 retry:
2535 iter.task = NULL;
2536 pid = find_ge_pid(iter.tgid, ns);
2537 if (pid) {
2538 iter.tgid = pid_nr_ns(pid, ns);
2539 iter.task = pid_task(pid, PIDTYPE_PID);
2540 /* What we to know is if the pid we have find is the
2541 * pid of a thread_group_leader. Testing for task
2542 * being a thread_group_leader is the obvious thing
2543 * todo but there is a window when it fails, due to
2544 * the pid transfer logic in de_thread.
2545 *
2546 * So we perform the straight forward test of seeing
2547 * if the pid we have found is the pid of a thread
2548 * group leader, and don't worry if the task we have
2549 * found doesn't happen to be a thread group leader.
2550 * As we don't care in the case of readdir.
2551 */
2552 if (!iter.task || !has_group_leader_pid(iter.task)) {
2553 iter.tgid += 1;
2554 goto retry;
2555 }
2556 get_task_struct(iter.task);
2557 }
2558 rcu_read_unlock();
2559 return iter;
2560 }
2561
2562 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2563
2564 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2565 struct tgid_iter iter)
2566 {
2567 char name[PROC_NUMBUF];
2568 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2569 return proc_fill_cache(filp, dirent, filldir, name, len,
2570 proc_pid_instantiate, iter.task, NULL);
2571 }
2572
2573 /* for the /proc/ directory itself, after non-process stuff has been done */
2574 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2575 {
2576 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2577 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2578 struct tgid_iter iter;
2579 struct pid_namespace *ns;
2580
2581 if (!reaper)
2582 goto out_no_task;
2583
2584 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2585 const struct pid_entry *p = &proc_base_stuff[nr];
2586 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2587 goto out;
2588 }
2589
2590 ns = filp->f_dentry->d_sb->s_fs_info;
2591 iter.task = NULL;
2592 iter.tgid = filp->f_pos - TGID_OFFSET;
2593 for (iter = next_tgid(ns, iter);
2594 iter.task;
2595 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2596 filp->f_pos = iter.tgid + TGID_OFFSET;
2597 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2598 put_task_struct(iter.task);
2599 goto out;
2600 }
2601 }
2602 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2603 out:
2604 put_task_struct(reaper);
2605 out_no_task:
2606 return 0;
2607 }
2608
2609 /*
2610 * Tasks
2611 */
2612 static const struct pid_entry tid_base_stuff[] = {
2613 DIR("fd", S_IRUSR|S_IXUSR, fd),
2614 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2615 REG("environ", S_IRUSR, environ),
2616 INF("auxv", S_IRUSR, pid_auxv),
2617 ONE("status", S_IRUGO, pid_status),
2618 INF("limits", S_IRUSR, pid_limits),
2619 #ifdef CONFIG_SCHED_DEBUG
2620 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2621 #endif
2622 INF("cmdline", S_IRUGO, pid_cmdline),
2623 ONE("stat", S_IRUGO, tid_stat),
2624 ONE("statm", S_IRUGO, pid_statm),
2625 REG("maps", S_IRUGO, maps),
2626 #ifdef CONFIG_NUMA
2627 REG("numa_maps", S_IRUGO, numa_maps),
2628 #endif
2629 REG("mem", S_IRUSR|S_IWUSR, mem),
2630 LNK("cwd", cwd),
2631 LNK("root", root),
2632 LNK("exe", exe),
2633 REG("mounts", S_IRUGO, mounts),
2634 #ifdef CONFIG_PROC_PAGE_MONITOR
2635 REG("clear_refs", S_IWUSR, clear_refs),
2636 REG("smaps", S_IRUGO, smaps),
2637 REG("pagemap", S_IRUSR, pagemap),
2638 #endif
2639 #ifdef CONFIG_SECURITY
2640 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2641 #endif
2642 #ifdef CONFIG_KALLSYMS
2643 INF("wchan", S_IRUGO, pid_wchan),
2644 #endif
2645 #ifdef CONFIG_SCHEDSTATS
2646 INF("schedstat", S_IRUGO, pid_schedstat),
2647 #endif
2648 #ifdef CONFIG_LATENCYTOP
2649 REG("latency", S_IRUGO, lstats),
2650 #endif
2651 #ifdef CONFIG_PROC_PID_CPUSET
2652 REG("cpuset", S_IRUGO, cpuset),
2653 #endif
2654 #ifdef CONFIG_CGROUPS
2655 REG("cgroup", S_IRUGO, cgroup),
2656 #endif
2657 INF("oom_score", S_IRUGO, oom_score),
2658 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2659 #ifdef CONFIG_AUDITSYSCALL
2660 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2661 #endif
2662 #ifdef CONFIG_FAULT_INJECTION
2663 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2664 #endif
2665 };
2666
2667 static int proc_tid_base_readdir(struct file * filp,
2668 void * dirent, filldir_t filldir)
2669 {
2670 return proc_pident_readdir(filp,dirent,filldir,
2671 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2672 }
2673
2674 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2675 return proc_pident_lookup(dir, dentry,
2676 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2677 }
2678
2679 static const struct file_operations proc_tid_base_operations = {
2680 .read = generic_read_dir,
2681 .readdir = proc_tid_base_readdir,
2682 };
2683
2684 static const struct inode_operations proc_tid_base_inode_operations = {
2685 .lookup = proc_tid_base_lookup,
2686 .getattr = pid_getattr,
2687 .setattr = proc_setattr,
2688 };
2689
2690 static struct dentry *proc_task_instantiate(struct inode *dir,
2691 struct dentry *dentry, struct task_struct *task, const void *ptr)
2692 {
2693 struct dentry *error = ERR_PTR(-ENOENT);
2694 struct inode *inode;
2695 inode = proc_pid_make_inode(dir->i_sb, task);
2696
2697 if (!inode)
2698 goto out;
2699 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2700 inode->i_op = &proc_tid_base_inode_operations;
2701 inode->i_fop = &proc_tid_base_operations;
2702 inode->i_flags|=S_IMMUTABLE;
2703 inode->i_nlink = 4;
2704 #ifdef CONFIG_SECURITY
2705 inode->i_nlink += 1;
2706 #endif
2707
2708 dentry->d_op = &pid_dentry_operations;
2709
2710 d_add(dentry, inode);
2711 /* Close the race of the process dying before we return the dentry */
2712 if (pid_revalidate(dentry, NULL))
2713 error = NULL;
2714 out:
2715 return error;
2716 }
2717
2718 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2719 {
2720 struct dentry *result = ERR_PTR(-ENOENT);
2721 struct task_struct *task;
2722 struct task_struct *leader = get_proc_task(dir);
2723 unsigned tid;
2724 struct pid_namespace *ns;
2725
2726 if (!leader)
2727 goto out_no_task;
2728
2729 tid = name_to_int(dentry);
2730 if (tid == ~0U)
2731 goto out;
2732
2733 ns = dentry->d_sb->s_fs_info;
2734 rcu_read_lock();
2735 task = find_task_by_pid_ns(tid, ns);
2736 if (task)
2737 get_task_struct(task);
2738 rcu_read_unlock();
2739 if (!task)
2740 goto out;
2741 if (!same_thread_group(leader, task))
2742 goto out_drop_task;
2743
2744 result = proc_task_instantiate(dir, dentry, task, NULL);
2745 out_drop_task:
2746 put_task_struct(task);
2747 out:
2748 put_task_struct(leader);
2749 out_no_task:
2750 return result;
2751 }
2752
2753 /*
2754 * Find the first tid of a thread group to return to user space.
2755 *
2756 * Usually this is just the thread group leader, but if the users
2757 * buffer was too small or there was a seek into the middle of the
2758 * directory we have more work todo.
2759 *
2760 * In the case of a short read we start with find_task_by_pid.
2761 *
2762 * In the case of a seek we start with the leader and walk nr
2763 * threads past it.
2764 */
2765 static struct task_struct *first_tid(struct task_struct *leader,
2766 int tid, int nr, struct pid_namespace *ns)
2767 {
2768 struct task_struct *pos;
2769
2770 rcu_read_lock();
2771 /* Attempt to start with the pid of a thread */
2772 if (tid && (nr > 0)) {
2773 pos = find_task_by_pid_ns(tid, ns);
2774 if (pos && (pos->group_leader == leader))
2775 goto found;
2776 }
2777
2778 /* If nr exceeds the number of threads there is nothing todo */
2779 pos = NULL;
2780 if (nr && nr >= get_nr_threads(leader))
2781 goto out;
2782
2783 /* If we haven't found our starting place yet start
2784 * with the leader and walk nr threads forward.
2785 */
2786 for (pos = leader; nr > 0; --nr) {
2787 pos = next_thread(pos);
2788 if (pos == leader) {
2789 pos = NULL;
2790 goto out;
2791 }
2792 }
2793 found:
2794 get_task_struct(pos);
2795 out:
2796 rcu_read_unlock();
2797 return pos;
2798 }
2799
2800 /*
2801 * Find the next thread in the thread list.
2802 * Return NULL if there is an error or no next thread.
2803 *
2804 * The reference to the input task_struct is released.
2805 */
2806 static struct task_struct *next_tid(struct task_struct *start)
2807 {
2808 struct task_struct *pos = NULL;
2809 rcu_read_lock();
2810 if (pid_alive(start)) {
2811 pos = next_thread(start);
2812 if (thread_group_leader(pos))
2813 pos = NULL;
2814 else
2815 get_task_struct(pos);
2816 }
2817 rcu_read_unlock();
2818 put_task_struct(start);
2819 return pos;
2820 }
2821
2822 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2823 struct task_struct *task, int tid)
2824 {
2825 char name[PROC_NUMBUF];
2826 int len = snprintf(name, sizeof(name), "%d", tid);
2827 return proc_fill_cache(filp, dirent, filldir, name, len,
2828 proc_task_instantiate, task, NULL);
2829 }
2830
2831 /* for the /proc/TGID/task/ directories */
2832 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2833 {
2834 struct dentry *dentry = filp->f_path.dentry;
2835 struct inode *inode = dentry->d_inode;
2836 struct task_struct *leader = NULL;
2837 struct task_struct *task;
2838 int retval = -ENOENT;
2839 ino_t ino;
2840 int tid;
2841 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2842 struct pid_namespace *ns;
2843
2844 task = get_proc_task(inode);
2845 if (!task)
2846 goto out_no_task;
2847 rcu_read_lock();
2848 if (pid_alive(task)) {
2849 leader = task->group_leader;
2850 get_task_struct(leader);
2851 }
2852 rcu_read_unlock();
2853 put_task_struct(task);
2854 if (!leader)
2855 goto out_no_task;
2856 retval = 0;
2857
2858 switch (pos) {
2859 case 0:
2860 ino = inode->i_ino;
2861 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2862 goto out;
2863 pos++;
2864 /* fall through */
2865 case 1:
2866 ino = parent_ino(dentry);
2867 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2868 goto out;
2869 pos++;
2870 /* fall through */
2871 }
2872
2873 /* f_version caches the tgid value that the last readdir call couldn't
2874 * return. lseek aka telldir automagically resets f_version to 0.
2875 */
2876 ns = filp->f_dentry->d_sb->s_fs_info;
2877 tid = (int)filp->f_version;
2878 filp->f_version = 0;
2879 for (task = first_tid(leader, tid, pos - 2, ns);
2880 task;
2881 task = next_tid(task), pos++) {
2882 tid = task_pid_nr_ns(task, ns);
2883 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2884 /* returning this tgid failed, save it as the first
2885 * pid for the next readir call */
2886 filp->f_version = (u64)tid;
2887 put_task_struct(task);
2888 break;
2889 }
2890 }
2891 out:
2892 filp->f_pos = pos;
2893 put_task_struct(leader);
2894 out_no_task:
2895 return retval;
2896 }
2897
2898 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2899 {
2900 struct inode *inode = dentry->d_inode;
2901 struct task_struct *p = get_proc_task(inode);
2902 generic_fillattr(inode, stat);
2903
2904 if (p) {
2905 rcu_read_lock();
2906 stat->nlink += get_nr_threads(p);
2907 rcu_read_unlock();
2908 put_task_struct(p);
2909 }
2910
2911 return 0;
2912 }
2913
2914 static const struct inode_operations proc_task_inode_operations = {
2915 .lookup = proc_task_lookup,
2916 .getattr = proc_task_getattr,
2917 .setattr = proc_setattr,
2918 };
2919
2920 static const struct file_operations proc_task_operations = {
2921 .read = generic_read_dir,
2922 .readdir = proc_task_readdir,
2923 };
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