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fec_mpc52xx: MPC52xx_MESSAGES_DEFAULT: 2nd NETIF_MSG_IFDOWN => IFUP
[linux-2.6/libata-dev.git] / fs / proc / base.c
blobc447e0743a3c95e231bc0e9f98a33d474c2e86bb
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/fdtable.h>
60 #include <linux/string.h>
61 #include <linux/seq_file.h>
62 #include <linux/namei.h>
63 #include <linux/mnt_namespace.h>
64 #include <linux/mm.h>
65 #include <linux/rcupdate.h>
66 #include <linux/kallsyms.h>
67 #include <linux/resource.h>
68 #include <linux/module.h>
69 #include <linux/mount.h>
70 #include <linux/security.h>
71 #include <linux/ptrace.h>
72 #include <linux/cgroup.h>
73 #include <linux/cpuset.h>
74 #include <linux/audit.h>
75 #include <linux/poll.h>
76 #include <linux/nsproxy.h>
77 #include <linux/oom.h>
78 #include <linux/elf.h>
79 #include <linux/pid_namespace.h>
80 #include "internal.h"
81
82 /* NOTE:
83 * Implementing inode permission operations in /proc is almost
84 * certainly an error. Permission checks need to happen during
85 * each system call not at open time. The reason is that most of
86 * what we wish to check for permissions in /proc varies at runtime.
87 *
88 * The classic example of a problem is opening file descriptors
89 * in /proc for a task before it execs a suid executable.
90 */
91
92 struct pid_entry {
93 char *name;
94 int len;
95 mode_t mode;
96 const struct inode_operations *iop;
97 const struct file_operations *fop;
98 union proc_op op;
99 };
100
101 #define NOD(NAME, MODE, IOP, FOP, OP) { \
102 .name = (NAME), \
103 .len = sizeof(NAME) - 1, \
104 .mode = MODE, \
105 .iop = IOP, \
106 .fop = FOP, \
107 .op = OP, \
108 }
109
110 #define DIR(NAME, MODE, OTYPE) \
111 NOD(NAME, (S_IFDIR|(MODE)), \
112 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
113 {} )
114 #define LNK(NAME, OTYPE) \
115 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
116 &proc_pid_link_inode_operations, NULL, \
117 { .proc_get_link = &proc_##OTYPE##_link } )
118 #define REG(NAME, MODE, OTYPE) \
119 NOD(NAME, (S_IFREG|(MODE)), NULL, \
120 &proc_##OTYPE##_operations, {})
121 #define INF(NAME, MODE, OTYPE) \
122 NOD(NAME, (S_IFREG|(MODE)), \
123 NULL, &proc_info_file_operations, \
124 { .proc_read = &proc_##OTYPE } )
125 #define ONE(NAME, MODE, OTYPE) \
126 NOD(NAME, (S_IFREG|(MODE)), \
127 NULL, &proc_single_file_operations, \
128 { .proc_show = &proc_##OTYPE } )
129
130 int maps_protect;
131 EXPORT_SYMBOL(maps_protect);
132
133 static struct fs_struct *get_fs_struct(struct task_struct *task)
134 {
135 struct fs_struct *fs;
136 task_lock(task);
137 fs = task->fs;
138 if(fs)
139 atomic_inc(&fs->count);
140 task_unlock(task);
141 return fs;
142 }
143
144 static int get_nr_threads(struct task_struct *tsk)
145 {
146 /* Must be called with the rcu_read_lock held */
147 unsigned long flags;
148 int count = 0;
149
150 if (lock_task_sighand(tsk, &flags)) {
151 count = atomic_read(&tsk->signal->count);
152 unlock_task_sighand(tsk, &flags);
153 }
154 return count;
155 }
156
157 static int proc_cwd_link(struct inode *inode, struct path *path)
158 {
159 struct task_struct *task = get_proc_task(inode);
160 struct fs_struct *fs = NULL;
161 int result = -ENOENT;
162
163 if (task) {
164 fs = get_fs_struct(task);
165 put_task_struct(task);
166 }
167 if (fs) {
168 read_lock(&fs->lock);
169 *path = fs->pwd;
170 path_get(&fs->pwd);
171 read_unlock(&fs->lock);
172 result = 0;
173 put_fs_struct(fs);
174 }
175 return result;
176 }
177
178 static int proc_root_link(struct inode *inode, struct path *path)
179 {
180 struct task_struct *task = get_proc_task(inode);
181 struct fs_struct *fs = NULL;
182 int result = -ENOENT;
183
184 if (task) {
185 fs = get_fs_struct(task);
186 put_task_struct(task);
187 }
188 if (fs) {
189 read_lock(&fs->lock);
190 *path = fs->root;
191 path_get(&fs->root);
192 read_unlock(&fs->lock);
193 result = 0;
194 put_fs_struct(fs);
195 }
196 return result;
197 }
198
199 /*
200 * Return zero if current may access user memory in @task, -error if not.
201 */
202 static int check_mem_permission(struct task_struct *task)
203 {
204 /*
205 * A task can always look at itself, in case it chooses
206 * to use system calls instead of load instructions.
207 */
208 if (task == current)
209 return 0;
210
211 /*
212 * If current is actively ptrace'ing, and would also be
213 * permitted to freshly attach with ptrace now, permit it.
214 */
215 if (task->parent == current && (task->ptrace & PT_PTRACED) &&
216 task_is_stopped_or_traced(task) &&
217 ptrace_may_attach(task))
218 return 0;
219
220 /*
221 * Noone else is allowed.
222 */
223 return -EPERM;
224 }
225
226 struct mm_struct *mm_for_maps(struct task_struct *task)
227 {
228 struct mm_struct *mm = get_task_mm(task);
229 if (!mm)
230 return NULL;
231 down_read(&mm->mmap_sem);
232 task_lock(task);
233 if (task->mm != mm)
234 goto out;
235 if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
236 goto out;
237 task_unlock(task);
238 return mm;
239 out:
240 task_unlock(task);
241 up_read(&mm->mmap_sem);
242 mmput(mm);
243 return NULL;
244 }
245
246 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
247 {
248 int res = 0;
249 unsigned int len;
250 struct mm_struct *mm = get_task_mm(task);
251 if (!mm)
252 goto out;
253 if (!mm->arg_end)
254 goto out_mm; /* Shh! No looking before we're done */
255
256 len = mm->arg_end - mm->arg_start;
257
258 if (len > PAGE_SIZE)
259 len = PAGE_SIZE;
260
261 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
262
263 // If the nul at the end of args has been overwritten, then
264 // assume application is using setproctitle(3).
265 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
266 len = strnlen(buffer, res);
267 if (len < res) {
268 res = len;
269 } else {
270 len = mm->env_end - mm->env_start;
271 if (len > PAGE_SIZE - res)
272 len = PAGE_SIZE - res;
273 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
274 res = strnlen(buffer, res);
275 }
276 }
277 out_mm:
278 mmput(mm);
279 out:
280 return res;
281 }
282
283 static int proc_pid_auxv(struct task_struct *task, char *buffer)
284 {
285 int res = 0;
286 struct mm_struct *mm = get_task_mm(task);
287 if (mm) {
288 unsigned int nwords = 0;
289 do
290 nwords += 2;
291 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
292 res = nwords * sizeof(mm->saved_auxv[0]);
293 if (res > PAGE_SIZE)
294 res = PAGE_SIZE;
295 memcpy(buffer, mm->saved_auxv, res);
296 mmput(mm);
297 }
298 return res;
299 }
300
301
302 #ifdef CONFIG_KALLSYMS
303 /*
304 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
305 * Returns the resolved symbol. If that fails, simply return the address.
306 */
307 static int proc_pid_wchan(struct task_struct *task, char *buffer)
308 {
309 unsigned long wchan;
310 char symname[KSYM_NAME_LEN];
311
312 wchan = get_wchan(task);
313
314 if (lookup_symbol_name(wchan, symname) < 0)
315 return sprintf(buffer, "%lu", wchan);
316 else
317 return sprintf(buffer, "%s", symname);
318 }
319 #endif /* CONFIG_KALLSYMS */
320
321 #ifdef CONFIG_SCHEDSTATS
322 /*
323 * Provides /proc/PID/schedstat
324 */
325 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
326 {
327 return sprintf(buffer, "%llu %llu %lu\n",
328 task->sched_info.cpu_time,
329 task->sched_info.run_delay,
330 task->sched_info.pcount);
331 }
332 #endif
333
334 #ifdef CONFIG_LATENCYTOP
335 static int lstats_show_proc(struct seq_file *m, void *v)
336 {
337 int i;
338 struct inode *inode = m->private;
339 struct task_struct *task = get_proc_task(inode);
340
341 if (!task)
342 return -ESRCH;
343 seq_puts(m, "Latency Top version : v0.1\n");
344 for (i = 0; i < 32; i++) {
345 if (task->latency_record[i].backtrace[0]) {
346 int q;
347 seq_printf(m, "%i %li %li ",
348 task->latency_record[i].count,
349 task->latency_record[i].time,
350 task->latency_record[i].max);
351 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
352 char sym[KSYM_NAME_LEN];
353 char *c;
354 if (!task->latency_record[i].backtrace[q])
355 break;
356 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
357 break;
358 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
359 c = strchr(sym, '+');
360 if (c)
361 *c = 0;
362 seq_printf(m, "%s ", sym);
363 }
364 seq_printf(m, "\n");
365 }
366
367 }
368 put_task_struct(task);
369 return 0;
370 }
371
372 static int lstats_open(struct inode *inode, struct file *file)
373 {
374 return single_open(file, lstats_show_proc, inode);
375 }
376
377 static ssize_t lstats_write(struct file *file, const char __user *buf,
378 size_t count, loff_t *offs)
379 {
380 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
381
382 if (!task)
383 return -ESRCH;
384 clear_all_latency_tracing(task);
385 put_task_struct(task);
386
387 return count;
388 }
389
390 static const struct file_operations proc_lstats_operations = {
391 .open = lstats_open,
392 .read = seq_read,
393 .write = lstats_write,
394 .llseek = seq_lseek,
395 .release = single_release,
396 };
397
398 #endif
399
400 /* The badness from the OOM killer */
401 unsigned long badness(struct task_struct *p, unsigned long uptime);
402 static int proc_oom_score(struct task_struct *task, char *buffer)
403 {
404 unsigned long points;
405 struct timespec uptime;
406
407 do_posix_clock_monotonic_gettime(&uptime);
408 read_lock(&tasklist_lock);
409 points = badness(task, uptime.tv_sec);
410 read_unlock(&tasklist_lock);
411 return sprintf(buffer, "%lu\n", points);
412 }
413
414 struct limit_names {
415 char *name;
416 char *unit;
417 };
418
419 static const struct limit_names lnames[RLIM_NLIMITS] = {
420 [RLIMIT_CPU] = {"Max cpu time", "ms"},
421 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
422 [RLIMIT_DATA] = {"Max data size", "bytes"},
423 [RLIMIT_STACK] = {"Max stack size", "bytes"},
424 [RLIMIT_CORE] = {"Max core file size", "bytes"},
425 [RLIMIT_RSS] = {"Max resident set", "bytes"},
426 [RLIMIT_NPROC] = {"Max processes", "processes"},
427 [RLIMIT_NOFILE] = {"Max open files", "files"},
428 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
429 [RLIMIT_AS] = {"Max address space", "bytes"},
430 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
431 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
432 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
433 [RLIMIT_NICE] = {"Max nice priority", NULL},
434 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
435 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
436 };
437
438 /* Display limits for a process */
439 static int proc_pid_limits(struct task_struct *task, char *buffer)
440 {
441 unsigned int i;
442 int count = 0;
443 unsigned long flags;
444 char *bufptr = buffer;
445
446 struct rlimit rlim[RLIM_NLIMITS];
447
448 rcu_read_lock();
449 if (!lock_task_sighand(task,&flags)) {
450 rcu_read_unlock();
451 return 0;
452 }
453 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
454 unlock_task_sighand(task, &flags);
455 rcu_read_unlock();
456
457 /*
458 * print the file header
459 */
460 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
461 "Limit", "Soft Limit", "Hard Limit", "Units");
462
463 for (i = 0; i < RLIM_NLIMITS; i++) {
464 if (rlim[i].rlim_cur == RLIM_INFINITY)
465 count += sprintf(&bufptr[count], "%-25s %-20s ",
466 lnames[i].name, "unlimited");
467 else
468 count += sprintf(&bufptr[count], "%-25s %-20lu ",
469 lnames[i].name, rlim[i].rlim_cur);
470
471 if (rlim[i].rlim_max == RLIM_INFINITY)
472 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
473 else
474 count += sprintf(&bufptr[count], "%-20lu ",
475 rlim[i].rlim_max);
476
477 if (lnames[i].unit)
478 count += sprintf(&bufptr[count], "%-10s\n",
479 lnames[i].unit);
480 else
481 count += sprintf(&bufptr[count], "\n");
482 }
483
484 return count;
485 }
486
487 /************************************************************************/
488 /* Here the fs part begins */
489 /************************************************************************/
490
491 /* permission checks */
492 static int proc_fd_access_allowed(struct inode *inode)
493 {
494 struct task_struct *task;
495 int allowed = 0;
496 /* Allow access to a task's file descriptors if it is us or we
497 * may use ptrace attach to the process and find out that
498 * information.
499 */
500 task = get_proc_task(inode);
501 if (task) {
502 allowed = ptrace_may_attach(task);
503 put_task_struct(task);
504 }
505 return allowed;
506 }
507
508 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
509 {
510 int error;
511 struct inode *inode = dentry->d_inode;
512
513 if (attr->ia_valid & ATTR_MODE)
514 return -EPERM;
515
516 error = inode_change_ok(inode, attr);
517 if (!error)
518 error = inode_setattr(inode, attr);
519 return error;
520 }
521
522 static const struct inode_operations proc_def_inode_operations = {
523 .setattr = proc_setattr,
524 };
525
526 static int mounts_open_common(struct inode *inode, struct file *file,
527 const struct seq_operations *op)
528 {
529 struct task_struct *task = get_proc_task(inode);
530 struct nsproxy *nsp;
531 struct mnt_namespace *ns = NULL;
532 struct fs_struct *fs = NULL;
533 struct path root;
534 struct proc_mounts *p;
535 int ret = -EINVAL;
536
537 if (task) {
538 rcu_read_lock();
539 nsp = task_nsproxy(task);
540 if (nsp) {
541 ns = nsp->mnt_ns;
542 if (ns)
543 get_mnt_ns(ns);
544 }
545 rcu_read_unlock();
546 if (ns)
547 fs = get_fs_struct(task);
548 put_task_struct(task);
549 }
550
551 if (!ns)
552 goto err;
553 if (!fs)
554 goto err_put_ns;
555
556 read_lock(&fs->lock);
557 root = fs->root;
558 path_get(&root);
559 read_unlock(&fs->lock);
560 put_fs_struct(fs);
561
562 ret = -ENOMEM;
563 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
564 if (!p)
565 goto err_put_path;
566
567 file->private_data = &p->m;
568 ret = seq_open(file, op);
569 if (ret)
570 goto err_free;
571
572 p->m.private = p;
573 p->ns = ns;
574 p->root = root;
575 p->event = ns->event;
576
577 return 0;
578
579 err_free:
580 kfree(p);
581 err_put_path:
582 path_put(&root);
583 err_put_ns:
584 put_mnt_ns(ns);
585 err:
586 return ret;
587 }
588
589 static int mounts_release(struct inode *inode, struct file *file)
590 {
591 struct proc_mounts *p = file->private_data;
592 path_put(&p->root);
593 put_mnt_ns(p->ns);
594 return seq_release(inode, file);
595 }
596
597 static unsigned mounts_poll(struct file *file, poll_table *wait)
598 {
599 struct proc_mounts *p = file->private_data;
600 struct mnt_namespace *ns = p->ns;
601 unsigned res = 0;
602
603 poll_wait(file, &ns->poll, wait);
604
605 spin_lock(&vfsmount_lock);
606 if (p->event != ns->event) {
607 p->event = ns->event;
608 res = POLLERR;
609 }
610 spin_unlock(&vfsmount_lock);
611
612 return res;
613 }
614
615 static int mounts_open(struct inode *inode, struct file *file)
616 {
617 return mounts_open_common(inode, file, &mounts_op);
618 }
619
620 static const struct file_operations proc_mounts_operations = {
621 .open = mounts_open,
622 .read = seq_read,
623 .llseek = seq_lseek,
624 .release = mounts_release,
625 .poll = mounts_poll,
626 };
627
628 static int mountinfo_open(struct inode *inode, struct file *file)
629 {
630 return mounts_open_common(inode, file, &mountinfo_op);
631 }
632
633 static const struct file_operations proc_mountinfo_operations = {
634 .open = mountinfo_open,
635 .read = seq_read,
636 .llseek = seq_lseek,
637 .release = mounts_release,
638 .poll = mounts_poll,
639 };
640
641 static int mountstats_open(struct inode *inode, struct file *file)
642 {
643 return mounts_open_common(inode, file, &mountstats_op);
644 }
645
646 static const struct file_operations proc_mountstats_operations = {
647 .open = mountstats_open,
648 .read = seq_read,
649 .llseek = seq_lseek,
650 .release = mounts_release,
651 };
652
653 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
654
655 static ssize_t proc_info_read(struct file * file, char __user * buf,
656 size_t count, loff_t *ppos)
657 {
658 struct inode * inode = file->f_path.dentry->d_inode;
659 unsigned long page;
660 ssize_t length;
661 struct task_struct *task = get_proc_task(inode);
662
663 length = -ESRCH;
664 if (!task)
665 goto out_no_task;
666
667 if (count > PROC_BLOCK_SIZE)
668 count = PROC_BLOCK_SIZE;
669
670 length = -ENOMEM;
671 if (!(page = __get_free_page(GFP_TEMPORARY)))
672 goto out;
673
674 length = PROC_I(inode)->op.proc_read(task, (char*)page);
675
676 if (length >= 0)
677 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
678 free_page(page);
679 out:
680 put_task_struct(task);
681 out_no_task:
682 return length;
683 }
684
685 static const struct file_operations proc_info_file_operations = {
686 .read = proc_info_read,
687 };
688
689 static int proc_single_show(struct seq_file *m, void *v)
690 {
691 struct inode *inode = m->private;
692 struct pid_namespace *ns;
693 struct pid *pid;
694 struct task_struct *task;
695 int ret;
696
697 ns = inode->i_sb->s_fs_info;
698 pid = proc_pid(inode);
699 task = get_pid_task(pid, PIDTYPE_PID);
700 if (!task)
701 return -ESRCH;
702
703 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
704
705 put_task_struct(task);
706 return ret;
707 }
708
709 static int proc_single_open(struct inode *inode, struct file *filp)
710 {
711 int ret;
712 ret = single_open(filp, proc_single_show, NULL);
713 if (!ret) {
714 struct seq_file *m = filp->private_data;
715
716 m->private = inode;
717 }
718 return ret;
719 }
720
721 static const struct file_operations proc_single_file_operations = {
722 .open = proc_single_open,
723 .read = seq_read,
724 .llseek = seq_lseek,
725 .release = single_release,
726 };
727
728 static int mem_open(struct inode* inode, struct file* file)
729 {
730 file->private_data = (void*)((long)current->self_exec_id);
731 return 0;
732 }
733
734 static ssize_t mem_read(struct file * file, char __user * buf,
735 size_t count, loff_t *ppos)
736 {
737 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
738 char *page;
739 unsigned long src = *ppos;
740 int ret = -ESRCH;
741 struct mm_struct *mm;
742
743 if (!task)
744 goto out_no_task;
745
746 if (check_mem_permission(task))
747 goto out;
748
749 ret = -ENOMEM;
750 page = (char *)__get_free_page(GFP_TEMPORARY);
751 if (!page)
752 goto out;
753
754 ret = 0;
755
756 mm = get_task_mm(task);
757 if (!mm)
758 goto out_free;
759
760 ret = -EIO;
761
762 if (file->private_data != (void*)((long)current->self_exec_id))
763 goto out_put;
764
765 ret = 0;
766
767 while (count > 0) {
768 int this_len, retval;
769
770 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
771 retval = access_process_vm(task, src, page, this_len, 0);
772 if (!retval || check_mem_permission(task)) {
773 if (!ret)
774 ret = -EIO;
775 break;
776 }
777
778 if (copy_to_user(buf, page, retval)) {
779 ret = -EFAULT;
780 break;
781 }
782
783 ret += retval;
784 src += retval;
785 buf += retval;
786 count -= retval;
787 }
788 *ppos = src;
789
790 out_put:
791 mmput(mm);
792 out_free:
793 free_page((unsigned long) page);
794 out:
795 put_task_struct(task);
796 out_no_task:
797 return ret;
798 }
799
800 #define mem_write NULL
801
802 #ifndef mem_write
803 /* This is a security hazard */
804 static ssize_t mem_write(struct file * file, const char __user *buf,
805 size_t count, loff_t *ppos)
806 {
807 int copied;
808 char *page;
809 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
810 unsigned long dst = *ppos;
811
812 copied = -ESRCH;
813 if (!task)
814 goto out_no_task;
815
816 if (check_mem_permission(task))
817 goto out;
818
819 copied = -ENOMEM;
820 page = (char *)__get_free_page(GFP_TEMPORARY);
821 if (!page)
822 goto out;
823
824 copied = 0;
825 while (count > 0) {
826 int this_len, retval;
827
828 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
829 if (copy_from_user(page, buf, this_len)) {
830 copied = -EFAULT;
831 break;
832 }
833 retval = access_process_vm(task, dst, page, this_len, 1);
834 if (!retval) {
835 if (!copied)
836 copied = -EIO;
837 break;
838 }
839 copied += retval;
840 buf += retval;
841 dst += retval;
842 count -= retval;
843 }
844 *ppos = dst;
845 free_page((unsigned long) page);
846 out:
847 put_task_struct(task);
848 out_no_task:
849 return copied;
850 }
851 #endif
852
853 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
854 {
855 switch (orig) {
856 case 0:
857 file->f_pos = offset;
858 break;
859 case 1:
860 file->f_pos += offset;
861 break;
862 default:
863 return -EINVAL;
864 }
865 force_successful_syscall_return();
866 return file->f_pos;
867 }
868
869 static const struct file_operations proc_mem_operations = {
870 .llseek = mem_lseek,
871 .read = mem_read,
872 .write = mem_write,
873 .open = mem_open,
874 };
875
876 static ssize_t environ_read(struct file *file, char __user *buf,
877 size_t count, loff_t *ppos)
878 {
879 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
880 char *page;
881 unsigned long src = *ppos;
882 int ret = -ESRCH;
883 struct mm_struct *mm;
884
885 if (!task)
886 goto out_no_task;
887
888 if (!ptrace_may_attach(task))
889 goto out;
890
891 ret = -ENOMEM;
892 page = (char *)__get_free_page(GFP_TEMPORARY);
893 if (!page)
894 goto out;
895
896 ret = 0;
897
898 mm = get_task_mm(task);
899 if (!mm)
900 goto out_free;
901
902 while (count > 0) {
903 int this_len, retval, max_len;
904
905 this_len = mm->env_end - (mm->env_start + src);
906
907 if (this_len <= 0)
908 break;
909
910 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
911 this_len = (this_len > max_len) ? max_len : this_len;
912
913 retval = access_process_vm(task, (mm->env_start + src),
914 page, this_len, 0);
915
916 if (retval <= 0) {
917 ret = retval;
918 break;
919 }
920
921 if (copy_to_user(buf, page, retval)) {
922 ret = -EFAULT;
923 break;
924 }
925
926 ret += retval;
927 src += retval;
928 buf += retval;
929 count -= retval;
930 }
931 *ppos = src;
932
933 mmput(mm);
934 out_free:
935 free_page((unsigned long) page);
936 out:
937 put_task_struct(task);
938 out_no_task:
939 return ret;
940 }
941
942 static const struct file_operations proc_environ_operations = {
943 .read = environ_read,
944 };
945
946 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
947 size_t count, loff_t *ppos)
948 {
949 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
950 char buffer[PROC_NUMBUF];
951 size_t len;
952 int oom_adjust;
953
954 if (!task)
955 return -ESRCH;
956 oom_adjust = task->oomkilladj;
957 put_task_struct(task);
958
959 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
960
961 return simple_read_from_buffer(buf, count, ppos, buffer, len);
962 }
963
964 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
965 size_t count, loff_t *ppos)
966 {
967 struct task_struct *task;
968 char buffer[PROC_NUMBUF], *end;
969 int oom_adjust;
970
971 memset(buffer, 0, sizeof(buffer));
972 if (count > sizeof(buffer) - 1)
973 count = sizeof(buffer) - 1;
974 if (copy_from_user(buffer, buf, count))
975 return -EFAULT;
976 oom_adjust = simple_strtol(buffer, &end, 0);
977 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
978 oom_adjust != OOM_DISABLE)
979 return -EINVAL;
980 if (*end == '\n')
981 end++;
982 task = get_proc_task(file->f_path.dentry->d_inode);
983 if (!task)
984 return -ESRCH;
985 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
986 put_task_struct(task);
987 return -EACCES;
988 }
989 task->oomkilladj = oom_adjust;
990 put_task_struct(task);
991 if (end - buffer == 0)
992 return -EIO;
993 return end - buffer;
994 }
995
996 static const struct file_operations proc_oom_adjust_operations = {
997 .read = oom_adjust_read,
998 .write = oom_adjust_write,
999 };
1000
1001 #ifdef CONFIG_AUDITSYSCALL
1002 #define TMPBUFLEN 21
1003 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1004 size_t count, loff_t *ppos)
1005 {
1006 struct inode * inode = file->f_path.dentry->d_inode;
1007 struct task_struct *task = get_proc_task(inode);
1008 ssize_t length;
1009 char tmpbuf[TMPBUFLEN];
1010
1011 if (!task)
1012 return -ESRCH;
1013 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1014 audit_get_loginuid(task));
1015 put_task_struct(task);
1016 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1017 }
1018
1019 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1020 size_t count, loff_t *ppos)
1021 {
1022 struct inode * inode = file->f_path.dentry->d_inode;
1023 char *page, *tmp;
1024 ssize_t length;
1025 uid_t loginuid;
1026
1027 if (!capable(CAP_AUDIT_CONTROL))
1028 return -EPERM;
1029
1030 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1031 return -EPERM;
1032
1033 if (count >= PAGE_SIZE)
1034 count = PAGE_SIZE - 1;
1035
1036 if (*ppos != 0) {
1037 /* No partial writes. */
1038 return -EINVAL;
1039 }
1040 page = (char*)__get_free_page(GFP_TEMPORARY);
1041 if (!page)
1042 return -ENOMEM;
1043 length = -EFAULT;
1044 if (copy_from_user(page, buf, count))
1045 goto out_free_page;
1046
1047 page[count] = '\0';
1048 loginuid = simple_strtoul(page, &tmp, 10);
1049 if (tmp == page) {
1050 length = -EINVAL;
1051 goto out_free_page;
1052
1053 }
1054 length = audit_set_loginuid(current, loginuid);
1055 if (likely(length == 0))
1056 length = count;
1057
1058 out_free_page:
1059 free_page((unsigned long) page);
1060 return length;
1061 }
1062
1063 static const struct file_operations proc_loginuid_operations = {
1064 .read = proc_loginuid_read,
1065 .write = proc_loginuid_write,
1066 };
1067
1068 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1069 size_t count, loff_t *ppos)
1070 {
1071 struct inode * inode = file->f_path.dentry->d_inode;
1072 struct task_struct *task = get_proc_task(inode);
1073 ssize_t length;
1074 char tmpbuf[TMPBUFLEN];
1075
1076 if (!task)
1077 return -ESRCH;
1078 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1079 audit_get_sessionid(task));
1080 put_task_struct(task);
1081 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1082 }
1083
1084 static const struct file_operations proc_sessionid_operations = {
1085 .read = proc_sessionid_read,
1086 };
1087 #endif
1088
1089 #ifdef CONFIG_FAULT_INJECTION
1090 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1091 size_t count, loff_t *ppos)
1092 {
1093 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1094 char buffer[PROC_NUMBUF];
1095 size_t len;
1096 int make_it_fail;
1097
1098 if (!task)
1099 return -ESRCH;
1100 make_it_fail = task->make_it_fail;
1101 put_task_struct(task);
1102
1103 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1104
1105 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1106 }
1107
1108 static ssize_t proc_fault_inject_write(struct file * file,
1109 const char __user * buf, size_t count, loff_t *ppos)
1110 {
1111 struct task_struct *task;
1112 char buffer[PROC_NUMBUF], *end;
1113 int make_it_fail;
1114
1115 if (!capable(CAP_SYS_RESOURCE))
1116 return -EPERM;
1117 memset(buffer, 0, sizeof(buffer));
1118 if (count > sizeof(buffer) - 1)
1119 count = sizeof(buffer) - 1;
1120 if (copy_from_user(buffer, buf, count))
1121 return -EFAULT;
1122 make_it_fail = simple_strtol(buffer, &end, 0);
1123 if (*end == '\n')
1124 end++;
1125 task = get_proc_task(file->f_dentry->d_inode);
1126 if (!task)
1127 return -ESRCH;
1128 task->make_it_fail = make_it_fail;
1129 put_task_struct(task);
1130 if (end - buffer == 0)
1131 return -EIO;
1132 return end - buffer;
1133 }
1134
1135 static const struct file_operations proc_fault_inject_operations = {
1136 .read = proc_fault_inject_read,
1137 .write = proc_fault_inject_write,
1138 };
1139 #endif
1140
1141
1142 #ifdef CONFIG_SCHED_DEBUG
1143 /*
1144 * Print out various scheduling related per-task fields:
1145 */
1146 static int sched_show(struct seq_file *m, void *v)
1147 {
1148 struct inode *inode = m->private;
1149 struct task_struct *p;
1150
1151 WARN_ON(!inode);
1152
1153 p = get_proc_task(inode);
1154 if (!p)
1155 return -ESRCH;
1156 proc_sched_show_task(p, m);
1157
1158 put_task_struct(p);
1159
1160 return 0;
1161 }
1162
1163 static ssize_t
1164 sched_write(struct file *file, const char __user *buf,
1165 size_t count, loff_t *offset)
1166 {
1167 struct inode *inode = file->f_path.dentry->d_inode;
1168 struct task_struct *p;
1169
1170 WARN_ON(!inode);
1171
1172 p = get_proc_task(inode);
1173 if (!p)
1174 return -ESRCH;
1175 proc_sched_set_task(p);
1176
1177 put_task_struct(p);
1178
1179 return count;
1180 }
1181
1182 static int sched_open(struct inode *inode, struct file *filp)
1183 {
1184 int ret;
1185
1186 ret = single_open(filp, sched_show, NULL);
1187 if (!ret) {
1188 struct seq_file *m = filp->private_data;
1189
1190 m->private = inode;
1191 }
1192 return ret;
1193 }
1194
1195 static const struct file_operations proc_pid_sched_operations = {
1196 .open = sched_open,
1197 .read = seq_read,
1198 .write = sched_write,
1199 .llseek = seq_lseek,
1200 .release = single_release,
1201 };
1202
1203 #endif
1204
1205 /*
1206 * We added or removed a vma mapping the executable. The vmas are only mapped
1207 * during exec and are not mapped with the mmap system call.
1208 * Callers must hold down_write() on the mm's mmap_sem for these
1209 */
1210 void added_exe_file_vma(struct mm_struct *mm)
1211 {
1212 mm->num_exe_file_vmas++;
1213 }
1214
1215 void removed_exe_file_vma(struct mm_struct *mm)
1216 {
1217 mm->num_exe_file_vmas--;
1218 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1219 fput(mm->exe_file);
1220 mm->exe_file = NULL;
1221 }
1222
1223 }
1224
1225 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1226 {
1227 if (new_exe_file)
1228 get_file(new_exe_file);
1229 if (mm->exe_file)
1230 fput(mm->exe_file);
1231 mm->exe_file = new_exe_file;
1232 mm->num_exe_file_vmas = 0;
1233 }
1234
1235 struct file *get_mm_exe_file(struct mm_struct *mm)
1236 {
1237 struct file *exe_file;
1238
1239 /* We need mmap_sem to protect against races with removal of
1240 * VM_EXECUTABLE vmas */
1241 down_read(&mm->mmap_sem);
1242 exe_file = mm->exe_file;
1243 if (exe_file)
1244 get_file(exe_file);
1245 up_read(&mm->mmap_sem);
1246 return exe_file;
1247 }
1248
1249 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1250 {
1251 /* It's safe to write the exe_file pointer without exe_file_lock because
1252 * this is called during fork when the task is not yet in /proc */
1253 newmm->exe_file = get_mm_exe_file(oldmm);
1254 }
1255
1256 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1257 {
1258 struct task_struct *task;
1259 struct mm_struct *mm;
1260 struct file *exe_file;
1261
1262 task = get_proc_task(inode);
1263 if (!task)
1264 return -ENOENT;
1265 mm = get_task_mm(task);
1266 put_task_struct(task);
1267 if (!mm)
1268 return -ENOENT;
1269 exe_file = get_mm_exe_file(mm);
1270 mmput(mm);
1271 if (exe_file) {
1272 *exe_path = exe_file->f_path;
1273 path_get(&exe_file->f_path);
1274 fput(exe_file);
1275 return 0;
1276 } else
1277 return -ENOENT;
1278 }
1279
1280 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1281 {
1282 struct inode *inode = dentry->d_inode;
1283 int error = -EACCES;
1284
1285 /* We don't need a base pointer in the /proc filesystem */
1286 path_put(&nd->path);
1287
1288 /* Are we allowed to snoop on the tasks file descriptors? */
1289 if (!proc_fd_access_allowed(inode))
1290 goto out;
1291
1292 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1293 nd->last_type = LAST_BIND;
1294 out:
1295 return ERR_PTR(error);
1296 }
1297
1298 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1299 {
1300 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1301 char *pathname;
1302 int len;
1303
1304 if (!tmp)
1305 return -ENOMEM;
1306
1307 pathname = d_path(path, tmp, PAGE_SIZE);
1308 len = PTR_ERR(pathname);
1309 if (IS_ERR(pathname))
1310 goto out;
1311 len = tmp + PAGE_SIZE - 1 - pathname;
1312
1313 if (len > buflen)
1314 len = buflen;
1315 if (copy_to_user(buffer, pathname, len))
1316 len = -EFAULT;
1317 out:
1318 free_page((unsigned long)tmp);
1319 return len;
1320 }
1321
1322 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1323 {
1324 int error = -EACCES;
1325 struct inode *inode = dentry->d_inode;
1326 struct path path;
1327
1328 /* Are we allowed to snoop on the tasks file descriptors? */
1329 if (!proc_fd_access_allowed(inode))
1330 goto out;
1331
1332 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1333 if (error)
1334 goto out;
1335
1336 error = do_proc_readlink(&path, buffer, buflen);
1337 path_put(&path);
1338 out:
1339 return error;
1340 }
1341
1342 static const struct inode_operations proc_pid_link_inode_operations = {
1343 .readlink = proc_pid_readlink,
1344 .follow_link = proc_pid_follow_link,
1345 .setattr = proc_setattr,
1346 };
1347
1348
1349 /* building an inode */
1350
1351 static int task_dumpable(struct task_struct *task)
1352 {
1353 int dumpable = 0;
1354 struct mm_struct *mm;
1355
1356 task_lock(task);
1357 mm = task->mm;
1358 if (mm)
1359 dumpable = get_dumpable(mm);
1360 task_unlock(task);
1361 if(dumpable == 1)
1362 return 1;
1363 return 0;
1364 }
1365
1366
1367 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1368 {
1369 struct inode * inode;
1370 struct proc_inode *ei;
1371
1372 /* We need a new inode */
1373
1374 inode = new_inode(sb);
1375 if (!inode)
1376 goto out;
1377
1378 /* Common stuff */
1379 ei = PROC_I(inode);
1380 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1381 inode->i_op = &proc_def_inode_operations;
1382
1383 /*
1384 * grab the reference to task.
1385 */
1386 ei->pid = get_task_pid(task, PIDTYPE_PID);
1387 if (!ei->pid)
1388 goto out_unlock;
1389
1390 inode->i_uid = 0;
1391 inode->i_gid = 0;
1392 if (task_dumpable(task)) {
1393 inode->i_uid = task->euid;
1394 inode->i_gid = task->egid;
1395 }
1396 security_task_to_inode(task, inode);
1397
1398 out:
1399 return inode;
1400
1401 out_unlock:
1402 iput(inode);
1403 return NULL;
1404 }
1405
1406 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1407 {
1408 struct inode *inode = dentry->d_inode;
1409 struct task_struct *task;
1410 generic_fillattr(inode, stat);
1411
1412 rcu_read_lock();
1413 stat->uid = 0;
1414 stat->gid = 0;
1415 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1416 if (task) {
1417 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1418 task_dumpable(task)) {
1419 stat->uid = task->euid;
1420 stat->gid = task->egid;
1421 }
1422 }
1423 rcu_read_unlock();
1424 return 0;
1425 }
1426
1427 /* dentry stuff */
1428
1429 /*
1430 * Exceptional case: normally we are not allowed to unhash a busy
1431 * directory. In this case, however, we can do it - no aliasing problems
1432 * due to the way we treat inodes.
1433 *
1434 * Rewrite the inode's ownerships here because the owning task may have
1435 * performed a setuid(), etc.
1436 *
1437 * Before the /proc/pid/status file was created the only way to read
1438 * the effective uid of a /process was to stat /proc/pid. Reading
1439 * /proc/pid/status is slow enough that procps and other packages
1440 * kept stating /proc/pid. To keep the rules in /proc simple I have
1441 * made this apply to all per process world readable and executable
1442 * directories.
1443 */
1444 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1445 {
1446 struct inode *inode = dentry->d_inode;
1447 struct task_struct *task = get_proc_task(inode);
1448 if (task) {
1449 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1450 task_dumpable(task)) {
1451 inode->i_uid = task->euid;
1452 inode->i_gid = task->egid;
1453 } else {
1454 inode->i_uid = 0;
1455 inode->i_gid = 0;
1456 }
1457 inode->i_mode &= ~(S_ISUID | S_ISGID);
1458 security_task_to_inode(task, inode);
1459 put_task_struct(task);
1460 return 1;
1461 }
1462 d_drop(dentry);
1463 return 0;
1464 }
1465
1466 static int pid_delete_dentry(struct dentry * dentry)
1467 {
1468 /* Is the task we represent dead?
1469 * If so, then don't put the dentry on the lru list,
1470 * kill it immediately.
1471 */
1472 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1473 }
1474
1475 static struct dentry_operations pid_dentry_operations =
1476 {
1477 .d_revalidate = pid_revalidate,
1478 .d_delete = pid_delete_dentry,
1479 };
1480
1481 /* Lookups */
1482
1483 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1484 struct task_struct *, const void *);
1485
1486 /*
1487 * Fill a directory entry.
1488 *
1489 * If possible create the dcache entry and derive our inode number and
1490 * file type from dcache entry.
1491 *
1492 * Since all of the proc inode numbers are dynamically generated, the inode
1493 * numbers do not exist until the inode is cache. This means creating the
1494 * the dcache entry in readdir is necessary to keep the inode numbers
1495 * reported by readdir in sync with the inode numbers reported
1496 * by stat.
1497 */
1498 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1499 char *name, int len,
1500 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1501 {
1502 struct dentry *child, *dir = filp->f_path.dentry;
1503 struct inode *inode;
1504 struct qstr qname;
1505 ino_t ino = 0;
1506 unsigned type = DT_UNKNOWN;
1507
1508 qname.name = name;
1509 qname.len = len;
1510 qname.hash = full_name_hash(name, len);
1511
1512 child = d_lookup(dir, &qname);
1513 if (!child) {
1514 struct dentry *new;
1515 new = d_alloc(dir, &qname);
1516 if (new) {
1517 child = instantiate(dir->d_inode, new, task, ptr);
1518 if (child)
1519 dput(new);
1520 else
1521 child = new;
1522 }
1523 }
1524 if (!child || IS_ERR(child) || !child->d_inode)
1525 goto end_instantiate;
1526 inode = child->d_inode;
1527 if (inode) {
1528 ino = inode->i_ino;
1529 type = inode->i_mode >> 12;
1530 }
1531 dput(child);
1532 end_instantiate:
1533 if (!ino)
1534 ino = find_inode_number(dir, &qname);
1535 if (!ino)
1536 ino = 1;
1537 return filldir(dirent, name, len, filp->f_pos, ino, type);
1538 }
1539
1540 static unsigned name_to_int(struct dentry *dentry)
1541 {
1542 const char *name = dentry->d_name.name;
1543 int len = dentry->d_name.len;
1544 unsigned n = 0;
1545
1546 if (len > 1 && *name == '0')
1547 goto out;
1548 while (len-- > 0) {
1549 unsigned c = *name++ - '0';
1550 if (c > 9)
1551 goto out;
1552 if (n >= (~0U-9)/10)
1553 goto out;
1554 n *= 10;
1555 n += c;
1556 }
1557 return n;
1558 out:
1559 return ~0U;
1560 }
1561
1562 #define PROC_FDINFO_MAX 64
1563
1564 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1565 {
1566 struct task_struct *task = get_proc_task(inode);
1567 struct files_struct *files = NULL;
1568 struct file *file;
1569 int fd = proc_fd(inode);
1570
1571 if (task) {
1572 files = get_files_struct(task);
1573 put_task_struct(task);
1574 }
1575 if (files) {
1576 /*
1577 * We are not taking a ref to the file structure, so we must
1578 * hold ->file_lock.
1579 */
1580 spin_lock(&files->file_lock);
1581 file = fcheck_files(files, fd);
1582 if (file) {
1583 if (path) {
1584 *path = file->f_path;
1585 path_get(&file->f_path);
1586 }
1587 if (info)
1588 snprintf(info, PROC_FDINFO_MAX,
1589 "pos:\t%lli\n"
1590 "flags:\t0%o\n",
1591 (long long) file->f_pos,
1592 file->f_flags);
1593 spin_unlock(&files->file_lock);
1594 put_files_struct(files);
1595 return 0;
1596 }
1597 spin_unlock(&files->file_lock);
1598 put_files_struct(files);
1599 }
1600 return -ENOENT;
1601 }
1602
1603 static int proc_fd_link(struct inode *inode, struct path *path)
1604 {
1605 return proc_fd_info(inode, path, NULL);
1606 }
1607
1608 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1609 {
1610 struct inode *inode = dentry->d_inode;
1611 struct task_struct *task = get_proc_task(inode);
1612 int fd = proc_fd(inode);
1613 struct files_struct *files;
1614
1615 if (task) {
1616 files = get_files_struct(task);
1617 if (files) {
1618 rcu_read_lock();
1619 if (fcheck_files(files, fd)) {
1620 rcu_read_unlock();
1621 put_files_struct(files);
1622 if (task_dumpable(task)) {
1623 inode->i_uid = task->euid;
1624 inode->i_gid = task->egid;
1625 } else {
1626 inode->i_uid = 0;
1627 inode->i_gid = 0;
1628 }
1629 inode->i_mode &= ~(S_ISUID | S_ISGID);
1630 security_task_to_inode(task, inode);
1631 put_task_struct(task);
1632 return 1;
1633 }
1634 rcu_read_unlock();
1635 put_files_struct(files);
1636 }
1637 put_task_struct(task);
1638 }
1639 d_drop(dentry);
1640 return 0;
1641 }
1642
1643 static struct dentry_operations tid_fd_dentry_operations =
1644 {
1645 .d_revalidate = tid_fd_revalidate,
1646 .d_delete = pid_delete_dentry,
1647 };
1648
1649 static struct dentry *proc_fd_instantiate(struct inode *dir,
1650 struct dentry *dentry, struct task_struct *task, const void *ptr)
1651 {
1652 unsigned fd = *(const unsigned *)ptr;
1653 struct file *file;
1654 struct files_struct *files;
1655 struct inode *inode;
1656 struct proc_inode *ei;
1657 struct dentry *error = ERR_PTR(-ENOENT);
1658
1659 inode = proc_pid_make_inode(dir->i_sb, task);
1660 if (!inode)
1661 goto out;
1662 ei = PROC_I(inode);
1663 ei->fd = fd;
1664 files = get_files_struct(task);
1665 if (!files)
1666 goto out_iput;
1667 inode->i_mode = S_IFLNK;
1668
1669 /*
1670 * We are not taking a ref to the file structure, so we must
1671 * hold ->file_lock.
1672 */
1673 spin_lock(&files->file_lock);
1674 file = fcheck_files(files, fd);
1675 if (!file)
1676 goto out_unlock;
1677 if (file->f_mode & 1)
1678 inode->i_mode |= S_IRUSR | S_IXUSR;
1679 if (file->f_mode & 2)
1680 inode->i_mode |= S_IWUSR | S_IXUSR;
1681 spin_unlock(&files->file_lock);
1682 put_files_struct(files);
1683
1684 inode->i_op = &proc_pid_link_inode_operations;
1685 inode->i_size = 64;
1686 ei->op.proc_get_link = proc_fd_link;
1687 dentry->d_op = &tid_fd_dentry_operations;
1688 d_add(dentry, inode);
1689 /* Close the race of the process dying before we return the dentry */
1690 if (tid_fd_revalidate(dentry, NULL))
1691 error = NULL;
1692
1693 out:
1694 return error;
1695 out_unlock:
1696 spin_unlock(&files->file_lock);
1697 put_files_struct(files);
1698 out_iput:
1699 iput(inode);
1700 goto out;
1701 }
1702
1703 static struct dentry *proc_lookupfd_common(struct inode *dir,
1704 struct dentry *dentry,
1705 instantiate_t instantiate)
1706 {
1707 struct task_struct *task = get_proc_task(dir);
1708 unsigned fd = name_to_int(dentry);
1709 struct dentry *result = ERR_PTR(-ENOENT);
1710
1711 if (!task)
1712 goto out_no_task;
1713 if (fd == ~0U)
1714 goto out;
1715
1716 result = instantiate(dir, dentry, task, &fd);
1717 out:
1718 put_task_struct(task);
1719 out_no_task:
1720 return result;
1721 }
1722
1723 static int proc_readfd_common(struct file * filp, void * dirent,
1724 filldir_t filldir, instantiate_t instantiate)
1725 {
1726 struct dentry *dentry = filp->f_path.dentry;
1727 struct inode *inode = dentry->d_inode;
1728 struct task_struct *p = get_proc_task(inode);
1729 unsigned int fd, ino;
1730 int retval;
1731 struct files_struct * files;
1732
1733 retval = -ENOENT;
1734 if (!p)
1735 goto out_no_task;
1736 retval = 0;
1737
1738 fd = filp->f_pos;
1739 switch (fd) {
1740 case 0:
1741 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1742 goto out;
1743 filp->f_pos++;
1744 case 1:
1745 ino = parent_ino(dentry);
1746 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1747 goto out;
1748 filp->f_pos++;
1749 default:
1750 files = get_files_struct(p);
1751 if (!files)
1752 goto out;
1753 rcu_read_lock();
1754 for (fd = filp->f_pos-2;
1755 fd < files_fdtable(files)->max_fds;
1756 fd++, filp->f_pos++) {
1757 char name[PROC_NUMBUF];
1758 int len;
1759
1760 if (!fcheck_files(files, fd))
1761 continue;
1762 rcu_read_unlock();
1763
1764 len = snprintf(name, sizeof(name), "%d", fd);
1765 if (proc_fill_cache(filp, dirent, filldir,
1766 name, len, instantiate,
1767 p, &fd) < 0) {
1768 rcu_read_lock();
1769 break;
1770 }
1771 rcu_read_lock();
1772 }
1773 rcu_read_unlock();
1774 put_files_struct(files);
1775 }
1776 out:
1777 put_task_struct(p);
1778 out_no_task:
1779 return retval;
1780 }
1781
1782 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1783 struct nameidata *nd)
1784 {
1785 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1786 }
1787
1788 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1789 {
1790 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1791 }
1792
1793 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1794 size_t len, loff_t *ppos)
1795 {
1796 char tmp[PROC_FDINFO_MAX];
1797 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1798 if (!err)
1799 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1800 return err;
1801 }
1802
1803 static const struct file_operations proc_fdinfo_file_operations = {
1804 .open = nonseekable_open,
1805 .read = proc_fdinfo_read,
1806 };
1807
1808 static const struct file_operations proc_fd_operations = {
1809 .read = generic_read_dir,
1810 .readdir = proc_readfd,
1811 };
1812
1813 /*
1814 * /proc/pid/fd needs a special permission handler so that a process can still
1815 * access /proc/self/fd after it has executed a setuid().
1816 */
1817 static int proc_fd_permission(struct inode *inode, int mask,
1818 struct nameidata *nd)
1819 {
1820 int rv;
1821
1822 rv = generic_permission(inode, mask, NULL);
1823 if (rv == 0)
1824 return 0;
1825 if (task_pid(current) == proc_pid(inode))
1826 rv = 0;
1827 return rv;
1828 }
1829
1830 /*
1831 * proc directories can do almost nothing..
1832 */
1833 static const struct inode_operations proc_fd_inode_operations = {
1834 .lookup = proc_lookupfd,
1835 .permission = proc_fd_permission,
1836 .setattr = proc_setattr,
1837 };
1838
1839 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1840 struct dentry *dentry, struct task_struct *task, const void *ptr)
1841 {
1842 unsigned fd = *(unsigned *)ptr;
1843 struct inode *inode;
1844 struct proc_inode *ei;
1845 struct dentry *error = ERR_PTR(-ENOENT);
1846
1847 inode = proc_pid_make_inode(dir->i_sb, task);
1848 if (!inode)
1849 goto out;
1850 ei = PROC_I(inode);
1851 ei->fd = fd;
1852 inode->i_mode = S_IFREG | S_IRUSR;
1853 inode->i_fop = &proc_fdinfo_file_operations;
1854 dentry->d_op = &tid_fd_dentry_operations;
1855 d_add(dentry, inode);
1856 /* Close the race of the process dying before we return the dentry */
1857 if (tid_fd_revalidate(dentry, NULL))
1858 error = NULL;
1859
1860 out:
1861 return error;
1862 }
1863
1864 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1865 struct dentry *dentry,
1866 struct nameidata *nd)
1867 {
1868 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1869 }
1870
1871 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1872 {
1873 return proc_readfd_common(filp, dirent, filldir,
1874 proc_fdinfo_instantiate);
1875 }
1876
1877 static const struct file_operations proc_fdinfo_operations = {
1878 .read = generic_read_dir,
1879 .readdir = proc_readfdinfo,
1880 };
1881
1882 /*
1883 * proc directories can do almost nothing..
1884 */
1885 static const struct inode_operations proc_fdinfo_inode_operations = {
1886 .lookup = proc_lookupfdinfo,
1887 .setattr = proc_setattr,
1888 };
1889
1890
1891 static struct dentry *proc_pident_instantiate(struct inode *dir,
1892 struct dentry *dentry, struct task_struct *task, const void *ptr)
1893 {
1894 const struct pid_entry *p = ptr;
1895 struct inode *inode;
1896 struct proc_inode *ei;
1897 struct dentry *error = ERR_PTR(-EINVAL);
1898
1899 inode = proc_pid_make_inode(dir->i_sb, task);
1900 if (!inode)
1901 goto out;
1902
1903 ei = PROC_I(inode);
1904 inode->i_mode = p->mode;
1905 if (S_ISDIR(inode->i_mode))
1906 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1907 if (p->iop)
1908 inode->i_op = p->iop;
1909 if (p->fop)
1910 inode->i_fop = p->fop;
1911 ei->op = p->op;
1912 dentry->d_op = &pid_dentry_operations;
1913 d_add(dentry, inode);
1914 /* Close the race of the process dying before we return the dentry */
1915 if (pid_revalidate(dentry, NULL))
1916 error = NULL;
1917 out:
1918 return error;
1919 }
1920
1921 static struct dentry *proc_pident_lookup(struct inode *dir,
1922 struct dentry *dentry,
1923 const struct pid_entry *ents,
1924 unsigned int nents)
1925 {
1926 struct inode *inode;
1927 struct dentry *error;
1928 struct task_struct *task = get_proc_task(dir);
1929 const struct pid_entry *p, *last;
1930
1931 error = ERR_PTR(-ENOENT);
1932 inode = NULL;
1933
1934 if (!task)
1935 goto out_no_task;
1936
1937 /*
1938 * Yes, it does not scale. And it should not. Don't add
1939 * new entries into /proc/<tgid>/ without very good reasons.
1940 */
1941 last = &ents[nents - 1];
1942 for (p = ents; p <= last; p++) {
1943 if (p->len != dentry->d_name.len)
1944 continue;
1945 if (!memcmp(dentry->d_name.name, p->name, p->len))
1946 break;
1947 }
1948 if (p > last)
1949 goto out;
1950
1951 error = proc_pident_instantiate(dir, dentry, task, p);
1952 out:
1953 put_task_struct(task);
1954 out_no_task:
1955 return error;
1956 }
1957
1958 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1959 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1960 {
1961 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1962 proc_pident_instantiate, task, p);
1963 }
1964
1965 static int proc_pident_readdir(struct file *filp,
1966 void *dirent, filldir_t filldir,
1967 const struct pid_entry *ents, unsigned int nents)
1968 {
1969 int i;
1970 struct dentry *dentry = filp->f_path.dentry;
1971 struct inode *inode = dentry->d_inode;
1972 struct task_struct *task = get_proc_task(inode);
1973 const struct pid_entry *p, *last;
1974 ino_t ino;
1975 int ret;
1976
1977 ret = -ENOENT;
1978 if (!task)
1979 goto out_no_task;
1980
1981 ret = 0;
1982 i = filp->f_pos;
1983 switch (i) {
1984 case 0:
1985 ino = inode->i_ino;
1986 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1987 goto out;
1988 i++;
1989 filp->f_pos++;
1990 /* fall through */
1991 case 1:
1992 ino = parent_ino(dentry);
1993 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1994 goto out;
1995 i++;
1996 filp->f_pos++;
1997 /* fall through */
1998 default:
1999 i -= 2;
2000 if (i >= nents) {
2001 ret = 1;
2002 goto out;
2003 }
2004 p = ents + i;
2005 last = &ents[nents - 1];
2006 while (p <= last) {
2007 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2008 goto out;
2009 filp->f_pos++;
2010 p++;
2011 }
2012 }
2013
2014 ret = 1;
2015 out:
2016 put_task_struct(task);
2017 out_no_task:
2018 return ret;
2019 }
2020
2021 #ifdef CONFIG_SECURITY
2022 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2023 size_t count, loff_t *ppos)
2024 {
2025 struct inode * inode = file->f_path.dentry->d_inode;
2026 char *p = NULL;
2027 ssize_t length;
2028 struct task_struct *task = get_proc_task(inode);
2029
2030 if (!task)
2031 return -ESRCH;
2032
2033 length = security_getprocattr(task,
2034 (char*)file->f_path.dentry->d_name.name,
2035 &p);
2036 put_task_struct(task);
2037 if (length > 0)
2038 length = simple_read_from_buffer(buf, count, ppos, p, length);
2039 kfree(p);
2040 return length;
2041 }
2042
2043 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2044 size_t count, loff_t *ppos)
2045 {
2046 struct inode * inode = file->f_path.dentry->d_inode;
2047 char *page;
2048 ssize_t length;
2049 struct task_struct *task = get_proc_task(inode);
2050
2051 length = -ESRCH;
2052 if (!task)
2053 goto out_no_task;
2054 if (count > PAGE_SIZE)
2055 count = PAGE_SIZE;
2056
2057 /* No partial writes. */
2058 length = -EINVAL;
2059 if (*ppos != 0)
2060 goto out;
2061
2062 length = -ENOMEM;
2063 page = (char*)__get_free_page(GFP_TEMPORARY);
2064 if (!page)
2065 goto out;
2066
2067 length = -EFAULT;
2068 if (copy_from_user(page, buf, count))
2069 goto out_free;
2070
2071 length = security_setprocattr(task,
2072 (char*)file->f_path.dentry->d_name.name,
2073 (void*)page, count);
2074 out_free:
2075 free_page((unsigned long) page);
2076 out:
2077 put_task_struct(task);
2078 out_no_task:
2079 return length;
2080 }
2081
2082 static const struct file_operations proc_pid_attr_operations = {
2083 .read = proc_pid_attr_read,
2084 .write = proc_pid_attr_write,
2085 };
2086
2087 static const struct pid_entry attr_dir_stuff[] = {
2088 REG("current", S_IRUGO|S_IWUGO, pid_attr),
2089 REG("prev", S_IRUGO, pid_attr),
2090 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
2091 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
2092 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
2093 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
2094 };
2095
2096 static int proc_attr_dir_readdir(struct file * filp,
2097 void * dirent, filldir_t filldir)
2098 {
2099 return proc_pident_readdir(filp,dirent,filldir,
2100 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2101 }
2102
2103 static const struct file_operations proc_attr_dir_operations = {
2104 .read = generic_read_dir,
2105 .readdir = proc_attr_dir_readdir,
2106 };
2107
2108 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2109 struct dentry *dentry, struct nameidata *nd)
2110 {
2111 return proc_pident_lookup(dir, dentry,
2112 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2113 }
2114
2115 static const struct inode_operations proc_attr_dir_inode_operations = {
2116 .lookup = proc_attr_dir_lookup,
2117 .getattr = pid_getattr,
2118 .setattr = proc_setattr,
2119 };
2120
2121 #endif
2122
2123 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2124 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2125 size_t count, loff_t *ppos)
2126 {
2127 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2128 struct mm_struct *mm;
2129 char buffer[PROC_NUMBUF];
2130 size_t len;
2131 int ret;
2132
2133 if (!task)
2134 return -ESRCH;
2135
2136 ret = 0;
2137 mm = get_task_mm(task);
2138 if (mm) {
2139 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2140 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2141 MMF_DUMP_FILTER_SHIFT));
2142 mmput(mm);
2143 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2144 }
2145
2146 put_task_struct(task);
2147
2148 return ret;
2149 }
2150
2151 static ssize_t proc_coredump_filter_write(struct file *file,
2152 const char __user *buf,
2153 size_t count,
2154 loff_t *ppos)
2155 {
2156 struct task_struct *task;
2157 struct mm_struct *mm;
2158 char buffer[PROC_NUMBUF], *end;
2159 unsigned int val;
2160 int ret;
2161 int i;
2162 unsigned long mask;
2163
2164 ret = -EFAULT;
2165 memset(buffer, 0, sizeof(buffer));
2166 if (count > sizeof(buffer) - 1)
2167 count = sizeof(buffer) - 1;
2168 if (copy_from_user(buffer, buf, count))
2169 goto out_no_task;
2170
2171 ret = -EINVAL;
2172 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2173 if (*end == '\n')
2174 end++;
2175 if (end - buffer == 0)
2176 goto out_no_task;
2177
2178 ret = -ESRCH;
2179 task = get_proc_task(file->f_dentry->d_inode);
2180 if (!task)
2181 goto out_no_task;
2182
2183 ret = end - buffer;
2184 mm = get_task_mm(task);
2185 if (!mm)
2186 goto out_no_mm;
2187
2188 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2189 if (val & mask)
2190 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2191 else
2192 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2193 }
2194
2195 mmput(mm);
2196 out_no_mm:
2197 put_task_struct(task);
2198 out_no_task:
2199 return ret;
2200 }
2201
2202 static const struct file_operations proc_coredump_filter_operations = {
2203 .read = proc_coredump_filter_read,
2204 .write = proc_coredump_filter_write,
2205 };
2206 #endif
2207
2208 /*
2209 * /proc/self:
2210 */
2211 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2212 int buflen)
2213 {
2214 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2215 pid_t tgid = task_tgid_nr_ns(current, ns);
2216 char tmp[PROC_NUMBUF];
2217 if (!tgid)
2218 return -ENOENT;
2219 sprintf(tmp, "%d", tgid);
2220 return vfs_readlink(dentry,buffer,buflen,tmp);
2221 }
2222
2223 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2224 {
2225 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2226 pid_t tgid = task_tgid_nr_ns(current, ns);
2227 char tmp[PROC_NUMBUF];
2228 if (!tgid)
2229 return ERR_PTR(-ENOENT);
2230 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2231 return ERR_PTR(vfs_follow_link(nd,tmp));
2232 }
2233
2234 static const struct inode_operations proc_self_inode_operations = {
2235 .readlink = proc_self_readlink,
2236 .follow_link = proc_self_follow_link,
2237 };
2238
2239 /*
2240 * proc base
2241 *
2242 * These are the directory entries in the root directory of /proc
2243 * that properly belong to the /proc filesystem, as they describe
2244 * describe something that is process related.
2245 */
2246 static const struct pid_entry proc_base_stuff[] = {
2247 NOD("self", S_IFLNK|S_IRWXUGO,
2248 &proc_self_inode_operations, NULL, {}),
2249 };
2250
2251 /*
2252 * Exceptional case: normally we are not allowed to unhash a busy
2253 * directory. In this case, however, we can do it - no aliasing problems
2254 * due to the way we treat inodes.
2255 */
2256 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2257 {
2258 struct inode *inode = dentry->d_inode;
2259 struct task_struct *task = get_proc_task(inode);
2260 if (task) {
2261 put_task_struct(task);
2262 return 1;
2263 }
2264 d_drop(dentry);
2265 return 0;
2266 }
2267
2268 static struct dentry_operations proc_base_dentry_operations =
2269 {
2270 .d_revalidate = proc_base_revalidate,
2271 .d_delete = pid_delete_dentry,
2272 };
2273
2274 static struct dentry *proc_base_instantiate(struct inode *dir,
2275 struct dentry *dentry, struct task_struct *task, const void *ptr)
2276 {
2277 const struct pid_entry *p = ptr;
2278 struct inode *inode;
2279 struct proc_inode *ei;
2280 struct dentry *error = ERR_PTR(-EINVAL);
2281
2282 /* Allocate the inode */
2283 error = ERR_PTR(-ENOMEM);
2284 inode = new_inode(dir->i_sb);
2285 if (!inode)
2286 goto out;
2287
2288 /* Initialize the inode */
2289 ei = PROC_I(inode);
2290 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2291
2292 /*
2293 * grab the reference to the task.
2294 */
2295 ei->pid = get_task_pid(task, PIDTYPE_PID);
2296 if (!ei->pid)
2297 goto out_iput;
2298
2299 inode->i_uid = 0;
2300 inode->i_gid = 0;
2301 inode->i_mode = p->mode;
2302 if (S_ISDIR(inode->i_mode))
2303 inode->i_nlink = 2;
2304 if (S_ISLNK(inode->i_mode))
2305 inode->i_size = 64;
2306 if (p->iop)
2307 inode->i_op = p->iop;
2308 if (p->fop)
2309 inode->i_fop = p->fop;
2310 ei->op = p->op;
2311 dentry->d_op = &proc_base_dentry_operations;
2312 d_add(dentry, inode);
2313 error = NULL;
2314 out:
2315 return error;
2316 out_iput:
2317 iput(inode);
2318 goto out;
2319 }
2320
2321 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2322 {
2323 struct dentry *error;
2324 struct task_struct *task = get_proc_task(dir);
2325 const struct pid_entry *p, *last;
2326
2327 error = ERR_PTR(-ENOENT);
2328
2329 if (!task)
2330 goto out_no_task;
2331
2332 /* Lookup the directory entry */
2333 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2334 for (p = proc_base_stuff; p <= last; p++) {
2335 if (p->len != dentry->d_name.len)
2336 continue;
2337 if (!memcmp(dentry->d_name.name, p->name, p->len))
2338 break;
2339 }
2340 if (p > last)
2341 goto out;
2342
2343 error = proc_base_instantiate(dir, dentry, task, p);
2344
2345 out:
2346 put_task_struct(task);
2347 out_no_task:
2348 return error;
2349 }
2350
2351 static int proc_base_fill_cache(struct file *filp, void *dirent,
2352 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2353 {
2354 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2355 proc_base_instantiate, task, p);
2356 }
2357
2358 #ifdef CONFIG_TASK_IO_ACCOUNTING
2359 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2360 {
2361 return sprintf(buffer,
2362 #ifdef CONFIG_TASK_XACCT
2363 "rchar: %llu\n"
2364 "wchar: %llu\n"
2365 "syscr: %llu\n"
2366 "syscw: %llu\n"
2367 #endif
2368 "read_bytes: %llu\n"
2369 "write_bytes: %llu\n"
2370 "cancelled_write_bytes: %llu\n",
2371 #ifdef CONFIG_TASK_XACCT
2372 (unsigned long long)task->rchar,
2373 (unsigned long long)task->wchar,
2374 (unsigned long long)task->syscr,
2375 (unsigned long long)task->syscw,
2376 #endif
2377 (unsigned long long)task->ioac.read_bytes,
2378 (unsigned long long)task->ioac.write_bytes,
2379 (unsigned long long)task->ioac.cancelled_write_bytes);
2380 }
2381 #endif
2382
2383 /*
2384 * Thread groups
2385 */
2386 static const struct file_operations proc_task_operations;
2387 static const struct inode_operations proc_task_inode_operations;
2388
2389 static const struct pid_entry tgid_base_stuff[] = {
2390 DIR("task", S_IRUGO|S_IXUGO, task),
2391 DIR("fd", S_IRUSR|S_IXUSR, fd),
2392 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2393 #ifdef CONFIG_NET
2394 DIR("net", S_IRUGO|S_IXUGO, net),
2395 #endif
2396 REG("environ", S_IRUSR, environ),
2397 INF("auxv", S_IRUSR, pid_auxv),
2398 ONE("status", S_IRUGO, pid_status),
2399 INF("limits", S_IRUSR, pid_limits),
2400 #ifdef CONFIG_SCHED_DEBUG
2401 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2402 #endif
2403 INF("cmdline", S_IRUGO, pid_cmdline),
2404 ONE("stat", S_IRUGO, tgid_stat),
2405 ONE("statm", S_IRUGO, pid_statm),
2406 REG("maps", S_IRUGO, maps),
2407 #ifdef CONFIG_NUMA
2408 REG("numa_maps", S_IRUGO, numa_maps),
2409 #endif
2410 REG("mem", S_IRUSR|S_IWUSR, mem),
2411 LNK("cwd", cwd),
2412 LNK("root", root),
2413 LNK("exe", exe),
2414 REG("mounts", S_IRUGO, mounts),
2415 REG("mountinfo", S_IRUGO, mountinfo),
2416 REG("mountstats", S_IRUSR, mountstats),
2417 #ifdef CONFIG_PROC_PAGE_MONITOR
2418 REG("clear_refs", S_IWUSR, clear_refs),
2419 REG("smaps", S_IRUGO, smaps),
2420 REG("pagemap", S_IRUSR, pagemap),
2421 #endif
2422 #ifdef CONFIG_SECURITY
2423 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2424 #endif
2425 #ifdef CONFIG_KALLSYMS
2426 INF("wchan", S_IRUGO, pid_wchan),
2427 #endif
2428 #ifdef CONFIG_SCHEDSTATS
2429 INF("schedstat", S_IRUGO, pid_schedstat),
2430 #endif
2431 #ifdef CONFIG_LATENCYTOP
2432 REG("latency", S_IRUGO, lstats),
2433 #endif
2434 #ifdef CONFIG_PROC_PID_CPUSET
2435 REG("cpuset", S_IRUGO, cpuset),
2436 #endif
2437 #ifdef CONFIG_CGROUPS
2438 REG("cgroup", S_IRUGO, cgroup),
2439 #endif
2440 INF("oom_score", S_IRUGO, oom_score),
2441 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2442 #ifdef CONFIG_AUDITSYSCALL
2443 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2444 REG("sessionid", S_IRUGO, sessionid),
2445 #endif
2446 #ifdef CONFIG_FAULT_INJECTION
2447 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2448 #endif
2449 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2450 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2451 #endif
2452 #ifdef CONFIG_TASK_IO_ACCOUNTING
2453 INF("io", S_IRUGO, pid_io_accounting),
2454 #endif
2455 };
2456
2457 static int proc_tgid_base_readdir(struct file * filp,
2458 void * dirent, filldir_t filldir)
2459 {
2460 return proc_pident_readdir(filp,dirent,filldir,
2461 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2462 }
2463
2464 static const struct file_operations proc_tgid_base_operations = {
2465 .read = generic_read_dir,
2466 .readdir = proc_tgid_base_readdir,
2467 };
2468
2469 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2470 return proc_pident_lookup(dir, dentry,
2471 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2472 }
2473
2474 static const struct inode_operations proc_tgid_base_inode_operations = {
2475 .lookup = proc_tgid_base_lookup,
2476 .getattr = pid_getattr,
2477 .setattr = proc_setattr,
2478 };
2479
2480 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2481 {
2482 struct dentry *dentry, *leader, *dir;
2483 char buf[PROC_NUMBUF];
2484 struct qstr name;
2485
2486 name.name = buf;
2487 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2488 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2489 if (dentry) {
2490 if (!(current->flags & PF_EXITING))
2491 shrink_dcache_parent(dentry);
2492 d_drop(dentry);
2493 dput(dentry);
2494 }
2495
2496 if (tgid == 0)
2497 goto out;
2498
2499 name.name = buf;
2500 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2501 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2502 if (!leader)
2503 goto out;
2504
2505 name.name = "task";
2506 name.len = strlen(name.name);
2507 dir = d_hash_and_lookup(leader, &name);
2508 if (!dir)
2509 goto out_put_leader;
2510
2511 name.name = buf;
2512 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2513 dentry = d_hash_and_lookup(dir, &name);
2514 if (dentry) {
2515 shrink_dcache_parent(dentry);
2516 d_drop(dentry);
2517 dput(dentry);
2518 }
2519
2520 dput(dir);
2521 out_put_leader:
2522 dput(leader);
2523 out:
2524 return;
2525 }
2526
2527 /**
2528 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2529 * @task: task that should be flushed.
2530 *
2531 * When flushing dentries from proc, one needs to flush them from global
2532 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2533 * in. This call is supposed to do all of this job.
2534 *
2535 * Looks in the dcache for
2536 * /proc/@pid
2537 * /proc/@tgid/task/@pid
2538 * if either directory is present flushes it and all of it'ts children
2539 * from the dcache.
2540 *
2541 * It is safe and reasonable to cache /proc entries for a task until
2542 * that task exits. After that they just clog up the dcache with
2543 * useless entries, possibly causing useful dcache entries to be
2544 * flushed instead. This routine is proved to flush those useless
2545 * dcache entries at process exit time.
2546 *
2547 * NOTE: This routine is just an optimization so it does not guarantee
2548 * that no dcache entries will exist at process exit time it
2549 * just makes it very unlikely that any will persist.
2550 */
2551
2552 void proc_flush_task(struct task_struct *task)
2553 {
2554 int i;
2555 struct pid *pid, *tgid = NULL;
2556 struct upid *upid;
2557
2558 pid = task_pid(task);
2559 if (thread_group_leader(task))
2560 tgid = task_tgid(task);
2561
2562 for (i = 0; i <= pid->level; i++) {
2563 upid = &pid->numbers[i];
2564 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2565 tgid ? tgid->numbers[i].nr : 0);
2566 }
2567
2568 upid = &pid->numbers[pid->level];
2569 if (upid->nr == 1)
2570 pid_ns_release_proc(upid->ns);
2571 }
2572
2573 static struct dentry *proc_pid_instantiate(struct inode *dir,
2574 struct dentry * dentry,
2575 struct task_struct *task, const void *ptr)
2576 {
2577 struct dentry *error = ERR_PTR(-ENOENT);
2578 struct inode *inode;
2579
2580 inode = proc_pid_make_inode(dir->i_sb, task);
2581 if (!inode)
2582 goto out;
2583
2584 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2585 inode->i_op = &proc_tgid_base_inode_operations;
2586 inode->i_fop = &proc_tgid_base_operations;
2587 inode->i_flags|=S_IMMUTABLE;
2588 inode->i_nlink = 5;
2589 #ifdef CONFIG_SECURITY
2590 inode->i_nlink += 1;
2591 #endif
2592
2593 dentry->d_op = &pid_dentry_operations;
2594
2595 d_add(dentry, inode);
2596 /* Close the race of the process dying before we return the dentry */
2597 if (pid_revalidate(dentry, NULL))
2598 error = NULL;
2599 out:
2600 return error;
2601 }
2602
2603 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2604 {
2605 struct dentry *result = ERR_PTR(-ENOENT);
2606 struct task_struct *task;
2607 unsigned tgid;
2608 struct pid_namespace *ns;
2609
2610 result = proc_base_lookup(dir, dentry);
2611 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2612 goto out;
2613
2614 tgid = name_to_int(dentry);
2615 if (tgid == ~0U)
2616 goto out;
2617
2618 ns = dentry->d_sb->s_fs_info;
2619 rcu_read_lock();
2620 task = find_task_by_pid_ns(tgid, ns);
2621 if (task)
2622 get_task_struct(task);
2623 rcu_read_unlock();
2624 if (!task)
2625 goto out;
2626
2627 result = proc_pid_instantiate(dir, dentry, task, NULL);
2628 put_task_struct(task);
2629 out:
2630 return result;
2631 }
2632
2633 /*
2634 * Find the first task with tgid >= tgid
2635 *
2636 */
2637 struct tgid_iter {
2638 unsigned int tgid;
2639 struct task_struct *task;
2640 };
2641 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2642 {
2643 struct pid *pid;
2644
2645 if (iter.task)
2646 put_task_struct(iter.task);
2647 rcu_read_lock();
2648 retry:
2649 iter.task = NULL;
2650 pid = find_ge_pid(iter.tgid, ns);
2651 if (pid) {
2652 iter.tgid = pid_nr_ns(pid, ns);
2653 iter.task = pid_task(pid, PIDTYPE_PID);
2654 /* What we to know is if the pid we have find is the
2655 * pid of a thread_group_leader. Testing for task
2656 * being a thread_group_leader is the obvious thing
2657 * todo but there is a window when it fails, due to
2658 * the pid transfer logic in de_thread.
2659 *
2660 * So we perform the straight forward test of seeing
2661 * if the pid we have found is the pid of a thread
2662 * group leader, and don't worry if the task we have
2663 * found doesn't happen to be a thread group leader.
2664 * As we don't care in the case of readdir.
2665 */
2666 if (!iter.task || !has_group_leader_pid(iter.task)) {
2667 iter.tgid += 1;
2668 goto retry;
2669 }
2670 get_task_struct(iter.task);
2671 }
2672 rcu_read_unlock();
2673 return iter;
2674 }
2675
2676 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2677
2678 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2679 struct tgid_iter iter)
2680 {
2681 char name[PROC_NUMBUF];
2682 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2683 return proc_fill_cache(filp, dirent, filldir, name, len,
2684 proc_pid_instantiate, iter.task, NULL);
2685 }
2686
2687 /* for the /proc/ directory itself, after non-process stuff has been done */
2688 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2689 {
2690 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2691 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2692 struct tgid_iter iter;
2693 struct pid_namespace *ns;
2694
2695 if (!reaper)
2696 goto out_no_task;
2697
2698 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2699 const struct pid_entry *p = &proc_base_stuff[nr];
2700 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2701 goto out;
2702 }
2703
2704 ns = filp->f_dentry->d_sb->s_fs_info;
2705 iter.task = NULL;
2706 iter.tgid = filp->f_pos - TGID_OFFSET;
2707 for (iter = next_tgid(ns, iter);
2708 iter.task;
2709 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2710 filp->f_pos = iter.tgid + TGID_OFFSET;
2711 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2712 put_task_struct(iter.task);
2713 goto out;
2714 }
2715 }
2716 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2717 out:
2718 put_task_struct(reaper);
2719 out_no_task:
2720 return 0;
2721 }
2722
2723 /*
2724 * Tasks
2725 */
2726 static const struct pid_entry tid_base_stuff[] = {
2727 DIR("fd", S_IRUSR|S_IXUSR, fd),
2728 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2729 REG("environ", S_IRUSR, environ),
2730 INF("auxv", S_IRUSR, pid_auxv),
2731 ONE("status", S_IRUGO, pid_status),
2732 INF("limits", S_IRUSR, pid_limits),
2733 #ifdef CONFIG_SCHED_DEBUG
2734 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2735 #endif
2736 INF("cmdline", S_IRUGO, pid_cmdline),
2737 ONE("stat", S_IRUGO, tid_stat),
2738 ONE("statm", S_IRUGO, pid_statm),
2739 REG("maps", S_IRUGO, maps),
2740 #ifdef CONFIG_NUMA
2741 REG("numa_maps", S_IRUGO, numa_maps),
2742 #endif
2743 REG("mem", S_IRUSR|S_IWUSR, mem),
2744 LNK("cwd", cwd),
2745 LNK("root", root),
2746 LNK("exe", exe),
2747 REG("mounts", S_IRUGO, mounts),
2748 REG("mountinfo", S_IRUGO, mountinfo),
2749 #ifdef CONFIG_PROC_PAGE_MONITOR
2750 REG("clear_refs", S_IWUSR, clear_refs),
2751 REG("smaps", S_IRUGO, smaps),
2752 REG("pagemap", S_IRUSR, pagemap),
2753 #endif
2754 #ifdef CONFIG_SECURITY
2755 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2756 #endif
2757 #ifdef CONFIG_KALLSYMS
2758 INF("wchan", S_IRUGO, pid_wchan),
2759 #endif
2760 #ifdef CONFIG_SCHEDSTATS
2761 INF("schedstat", S_IRUGO, pid_schedstat),
2762 #endif
2763 #ifdef CONFIG_LATENCYTOP
2764 REG("latency", S_IRUGO, lstats),
2765 #endif
2766 #ifdef CONFIG_PROC_PID_CPUSET
2767 REG("cpuset", S_IRUGO, cpuset),
2768 #endif
2769 #ifdef CONFIG_CGROUPS
2770 REG("cgroup", S_IRUGO, cgroup),
2771 #endif
2772 INF("oom_score", S_IRUGO, oom_score),
2773 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2774 #ifdef CONFIG_AUDITSYSCALL
2775 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2776 REG("sessionid", S_IRUSR, sessionid),
2777 #endif
2778 #ifdef CONFIG_FAULT_INJECTION
2779 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2780 #endif
2781 };
2782
2783 static int proc_tid_base_readdir(struct file * filp,
2784 void * dirent, filldir_t filldir)
2785 {
2786 return proc_pident_readdir(filp,dirent,filldir,
2787 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2788 }
2789
2790 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2791 return proc_pident_lookup(dir, dentry,
2792 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2793 }
2794
2795 static const struct file_operations proc_tid_base_operations = {
2796 .read = generic_read_dir,
2797 .readdir = proc_tid_base_readdir,
2798 };
2799
2800 static const struct inode_operations proc_tid_base_inode_operations = {
2801 .lookup = proc_tid_base_lookup,
2802 .getattr = pid_getattr,
2803 .setattr = proc_setattr,
2804 };
2805
2806 static struct dentry *proc_task_instantiate(struct inode *dir,
2807 struct dentry *dentry, struct task_struct *task, const void *ptr)
2808 {
2809 struct dentry *error = ERR_PTR(-ENOENT);
2810 struct inode *inode;
2811 inode = proc_pid_make_inode(dir->i_sb, task);
2812
2813 if (!inode)
2814 goto out;
2815 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2816 inode->i_op = &proc_tid_base_inode_operations;
2817 inode->i_fop = &proc_tid_base_operations;
2818 inode->i_flags|=S_IMMUTABLE;
2819 inode->i_nlink = 4;
2820 #ifdef CONFIG_SECURITY
2821 inode->i_nlink += 1;
2822 #endif
2823
2824 dentry->d_op = &pid_dentry_operations;
2825
2826 d_add(dentry, inode);
2827 /* Close the race of the process dying before we return the dentry */
2828 if (pid_revalidate(dentry, NULL))
2829 error = NULL;
2830 out:
2831 return error;
2832 }
2833
2834 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2835 {
2836 struct dentry *result = ERR_PTR(-ENOENT);
2837 struct task_struct *task;
2838 struct task_struct *leader = get_proc_task(dir);
2839 unsigned tid;
2840 struct pid_namespace *ns;
2841
2842 if (!leader)
2843 goto out_no_task;
2844
2845 tid = name_to_int(dentry);
2846 if (tid == ~0U)
2847 goto out;
2848
2849 ns = dentry->d_sb->s_fs_info;
2850 rcu_read_lock();
2851 task = find_task_by_pid_ns(tid, ns);
2852 if (task)
2853 get_task_struct(task);
2854 rcu_read_unlock();
2855 if (!task)
2856 goto out;
2857 if (!same_thread_group(leader, task))
2858 goto out_drop_task;
2859
2860 result = proc_task_instantiate(dir, dentry, task, NULL);
2861 out_drop_task:
2862 put_task_struct(task);
2863 out:
2864 put_task_struct(leader);
2865 out_no_task:
2866 return result;
2867 }
2868
2869 /*
2870 * Find the first tid of a thread group to return to user space.
2871 *
2872 * Usually this is just the thread group leader, but if the users
2873 * buffer was too small or there was a seek into the middle of the
2874 * directory we have more work todo.
2875 *
2876 * In the case of a short read we start with find_task_by_pid.
2877 *
2878 * In the case of a seek we start with the leader and walk nr
2879 * threads past it.
2880 */
2881 static struct task_struct *first_tid(struct task_struct *leader,
2882 int tid, int nr, struct pid_namespace *ns)
2883 {
2884 struct task_struct *pos;
2885
2886 rcu_read_lock();
2887 /* Attempt to start with the pid of a thread */
2888 if (tid && (nr > 0)) {
2889 pos = find_task_by_pid_ns(tid, ns);
2890 if (pos && (pos->group_leader == leader))
2891 goto found;
2892 }
2893
2894 /* If nr exceeds the number of threads there is nothing todo */
2895 pos = NULL;
2896 if (nr && nr >= get_nr_threads(leader))
2897 goto out;
2898
2899 /* If we haven't found our starting place yet start
2900 * with the leader and walk nr threads forward.
2901 */
2902 for (pos = leader; nr > 0; --nr) {
2903 pos = next_thread(pos);
2904 if (pos == leader) {
2905 pos = NULL;
2906 goto out;
2907 }
2908 }
2909 found:
2910 get_task_struct(pos);
2911 out:
2912 rcu_read_unlock();
2913 return pos;
2914 }
2915
2916 /*
2917 * Find the next thread in the thread list.
2918 * Return NULL if there is an error or no next thread.
2919 *
2920 * The reference to the input task_struct is released.
2921 */
2922 static struct task_struct *next_tid(struct task_struct *start)
2923 {
2924 struct task_struct *pos = NULL;
2925 rcu_read_lock();
2926 if (pid_alive(start)) {
2927 pos = next_thread(start);
2928 if (thread_group_leader(pos))
2929 pos = NULL;
2930 else
2931 get_task_struct(pos);
2932 }
2933 rcu_read_unlock();
2934 put_task_struct(start);
2935 return pos;
2936 }
2937
2938 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2939 struct task_struct *task, int tid)
2940 {
2941 char name[PROC_NUMBUF];
2942 int len = snprintf(name, sizeof(name), "%d", tid);
2943 return proc_fill_cache(filp, dirent, filldir, name, len,
2944 proc_task_instantiate, task, NULL);
2945 }
2946
2947 /* for the /proc/TGID/task/ directories */
2948 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2949 {
2950 struct dentry *dentry = filp->f_path.dentry;
2951 struct inode *inode = dentry->d_inode;
2952 struct task_struct *leader = NULL;
2953 struct task_struct *task;
2954 int retval = -ENOENT;
2955 ino_t ino;
2956 int tid;
2957 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2958 struct pid_namespace *ns;
2959
2960 task = get_proc_task(inode);
2961 if (!task)
2962 goto out_no_task;
2963 rcu_read_lock();
2964 if (pid_alive(task)) {
2965 leader = task->group_leader;
2966 get_task_struct(leader);
2967 }
2968 rcu_read_unlock();
2969 put_task_struct(task);
2970 if (!leader)
2971 goto out_no_task;
2972 retval = 0;
2973
2974 switch (pos) {
2975 case 0:
2976 ino = inode->i_ino;
2977 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2978 goto out;
2979 pos++;
2980 /* fall through */
2981 case 1:
2982 ino = parent_ino(dentry);
2983 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2984 goto out;
2985 pos++;
2986 /* fall through */
2987 }
2988
2989 /* f_version caches the tgid value that the last readdir call couldn't
2990 * return. lseek aka telldir automagically resets f_version to 0.
2991 */
2992 ns = filp->f_dentry->d_sb->s_fs_info;
2993 tid = (int)filp->f_version;
2994 filp->f_version = 0;
2995 for (task = first_tid(leader, tid, pos - 2, ns);
2996 task;
2997 task = next_tid(task), pos++) {
2998 tid = task_pid_nr_ns(task, ns);
2999 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3000 /* returning this tgid failed, save it as the first
3001 * pid for the next readir call */
3002 filp->f_version = (u64)tid;
3003 put_task_struct(task);
3004 break;
3005 }
3006 }
3007 out:
3008 filp->f_pos = pos;
3009 put_task_struct(leader);
3010 out_no_task:
3011 return retval;
3012 }
3013
3014 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3015 {
3016 struct inode *inode = dentry->d_inode;
3017 struct task_struct *p = get_proc_task(inode);
3018 generic_fillattr(inode, stat);
3019
3020 if (p) {
3021 rcu_read_lock();
3022 stat->nlink += get_nr_threads(p);
3023 rcu_read_unlock();
3024 put_task_struct(p);
3025 }
3026
3027 return 0;
3028 }
3029
3030 static const struct inode_operations proc_task_inode_operations = {
3031 .lookup = proc_task_lookup,
3032 .getattr = proc_task_getattr,
3033 .setattr = proc_setattr,
3034 };
3035
3036 static const struct file_operations proc_task_operations = {
3037 .read = generic_read_dir,
3038 .readdir = proc_task_readdir,
3039 };
Linux 2.6 libata-dev (mirror)