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[PATCH] net: Kill some unneeded allocation return value casts in libertas
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / base.c
blob19489b0d5554860e28a1b7e6aeefc5d23fa0d992
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/module.h>
67 #include <linux/mount.h>
68 #include <linux/security.h>
69 #include <linux/ptrace.h>
70 #include <linux/cpuset.h>
71 #include <linux/audit.h>
72 #include <linux/poll.h>
73 #include <linux/nsproxy.h>
74 #include <linux/oom.h>
75 #include <linux/elf.h>
76 #include "internal.h"
77
78 /* NOTE:
79 * Implementing inode permission operations in /proc is almost
80 * certainly an error. Permission checks need to happen during
81 * each system call not at open time. The reason is that most of
82 * what we wish to check for permissions in /proc varies at runtime.
83 *
84 * The classic example of a problem is opening file descriptors
85 * in /proc for a task before it execs a suid executable.
86 */
87
88
89 /* Worst case buffer size needed for holding an integer. */
90 #define PROC_NUMBUF 13
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
126 int maps_protect;
127 EXPORT_SYMBOL(maps_protect);
128
129 static struct fs_struct *get_fs_struct(struct task_struct *task)
130 {
131 struct fs_struct *fs;
132 task_lock(task);
133 fs = task->fs;
134 if(fs)
135 atomic_inc(&fs->count);
136 task_unlock(task);
137 return fs;
138 }
139
140 static int get_nr_threads(struct task_struct *tsk)
141 {
142 /* Must be called with the rcu_read_lock held */
143 unsigned long flags;
144 int count = 0;
145
146 if (lock_task_sighand(tsk, &flags)) {
147 count = atomic_read(&tsk->signal->count);
148 unlock_task_sighand(tsk, &flags);
149 }
150 return count;
151 }
152
153 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
154 {
155 struct task_struct *task = get_proc_task(inode);
156 struct fs_struct *fs = NULL;
157 int result = -ENOENT;
158
159 if (task) {
160 fs = get_fs_struct(task);
161 put_task_struct(task);
162 }
163 if (fs) {
164 read_lock(&fs->lock);
165 *mnt = mntget(fs->pwdmnt);
166 *dentry = dget(fs->pwd);
167 read_unlock(&fs->lock);
168 result = 0;
169 put_fs_struct(fs);
170 }
171 return result;
172 }
173
174 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
175 {
176 struct task_struct *task = get_proc_task(inode);
177 struct fs_struct *fs = NULL;
178 int result = -ENOENT;
179
180 if (task) {
181 fs = get_fs_struct(task);
182 put_task_struct(task);
183 }
184 if (fs) {
185 read_lock(&fs->lock);
186 *mnt = mntget(fs->rootmnt);
187 *dentry = dget(fs->root);
188 read_unlock(&fs->lock);
189 result = 0;
190 put_fs_struct(fs);
191 }
192 return result;
193 }
194
195 #define MAY_PTRACE(task) \
196 (task == current || \
197 (task->parent == current && \
198 (task->ptrace & PT_PTRACED) && \
199 (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
200 security_ptrace(current,task) == 0))
201
202 static int proc_pid_environ(struct task_struct *task, char * buffer)
203 {
204 int res = 0;
205 struct mm_struct *mm = get_task_mm(task);
206 if (mm) {
207 unsigned int len;
208
209 res = -ESRCH;
210 if (!ptrace_may_attach(task))
211 goto out;
212
213 len = mm->env_end - mm->env_start;
214 if (len > PAGE_SIZE)
215 len = PAGE_SIZE;
216 res = access_process_vm(task, mm->env_start, buffer, len, 0);
217 out:
218 mmput(mm);
219 }
220 return res;
221 }
222
223 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
224 {
225 int res = 0;
226 unsigned int len;
227 struct mm_struct *mm = get_task_mm(task);
228 if (!mm)
229 goto out;
230 if (!mm->arg_end)
231 goto out_mm; /* Shh! No looking before we're done */
232
233 len = mm->arg_end - mm->arg_start;
234
235 if (len > PAGE_SIZE)
236 len = PAGE_SIZE;
237
238 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
239
240 // If the nul at the end of args has been overwritten, then
241 // assume application is using setproctitle(3).
242 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
243 len = strnlen(buffer, res);
244 if (len < res) {
245 res = len;
246 } else {
247 len = mm->env_end - mm->env_start;
248 if (len > PAGE_SIZE - res)
249 len = PAGE_SIZE - res;
250 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
251 res = strnlen(buffer, res);
252 }
253 }
254 out_mm:
255 mmput(mm);
256 out:
257 return res;
258 }
259
260 static int proc_pid_auxv(struct task_struct *task, char *buffer)
261 {
262 int res = 0;
263 struct mm_struct *mm = get_task_mm(task);
264 if (mm) {
265 unsigned int nwords = 0;
266 do
267 nwords += 2;
268 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
269 res = nwords * sizeof(mm->saved_auxv[0]);
270 if (res > PAGE_SIZE)
271 res = PAGE_SIZE;
272 memcpy(buffer, mm->saved_auxv, res);
273 mmput(mm);
274 }
275 return res;
276 }
277
278
279 #ifdef CONFIG_KALLSYMS
280 /*
281 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
282 * Returns the resolved symbol. If that fails, simply return the address.
283 */
284 static int proc_pid_wchan(struct task_struct *task, char *buffer)
285 {
286 unsigned long wchan;
287 char symname[KSYM_NAME_LEN];
288
289 wchan = get_wchan(task);
290
291 if (lookup_symbol_name(wchan, symname) < 0)
292 return sprintf(buffer, "%lu", wchan);
293 else
294 return sprintf(buffer, "%s", symname);
295 }
296 #endif /* CONFIG_KALLSYMS */
297
298 #ifdef CONFIG_SCHEDSTATS
299 /*
300 * Provides /proc/PID/schedstat
301 */
302 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
303 {
304 return sprintf(buffer, "%llu %llu %lu\n",
305 task->sched_info.cpu_time,
306 task->sched_info.run_delay,
307 task->sched_info.pcnt);
308 }
309 #endif
310
311 /* The badness from the OOM killer */
312 unsigned long badness(struct task_struct *p, unsigned long uptime);
313 static int proc_oom_score(struct task_struct *task, char *buffer)
314 {
315 unsigned long points;
316 struct timespec uptime;
317
318 do_posix_clock_monotonic_gettime(&uptime);
319 read_lock(&tasklist_lock);
320 points = badness(task, uptime.tv_sec);
321 read_unlock(&tasklist_lock);
322 return sprintf(buffer, "%lu\n", points);
323 }
324
325 /************************************************************************/
326 /* Here the fs part begins */
327 /************************************************************************/
328
329 /* permission checks */
330 static int proc_fd_access_allowed(struct inode *inode)
331 {
332 struct task_struct *task;
333 int allowed = 0;
334 /* Allow access to a task's file descriptors if it is us or we
335 * may use ptrace attach to the process and find out that
336 * information.
337 */
338 task = get_proc_task(inode);
339 if (task) {
340 allowed = ptrace_may_attach(task);
341 put_task_struct(task);
342 }
343 return allowed;
344 }
345
346 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
347 {
348 int error;
349 struct inode *inode = dentry->d_inode;
350
351 if (attr->ia_valid & ATTR_MODE)
352 return -EPERM;
353
354 error = inode_change_ok(inode, attr);
355 if (!error)
356 error = inode_setattr(inode, attr);
357 return error;
358 }
359
360 static const struct inode_operations proc_def_inode_operations = {
361 .setattr = proc_setattr,
362 };
363
364 extern struct seq_operations mounts_op;
365 struct proc_mounts {
366 struct seq_file m;
367 int event;
368 };
369
370 static int mounts_open(struct inode *inode, struct file *file)
371 {
372 struct task_struct *task = get_proc_task(inode);
373 struct mnt_namespace *ns = NULL;
374 struct proc_mounts *p;
375 int ret = -EINVAL;
376
377 if (task) {
378 task_lock(task);
379 if (task->nsproxy) {
380 ns = task->nsproxy->mnt_ns;
381 if (ns)
382 get_mnt_ns(ns);
383 }
384 task_unlock(task);
385 put_task_struct(task);
386 }
387
388 if (ns) {
389 ret = -ENOMEM;
390 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
391 if (p) {
392 file->private_data = &p->m;
393 ret = seq_open(file, &mounts_op);
394 if (!ret) {
395 p->m.private = ns;
396 p->event = ns->event;
397 return 0;
398 }
399 kfree(p);
400 }
401 put_mnt_ns(ns);
402 }
403 return ret;
404 }
405
406 static int mounts_release(struct inode *inode, struct file *file)
407 {
408 struct seq_file *m = file->private_data;
409 struct mnt_namespace *ns = m->private;
410 put_mnt_ns(ns);
411 return seq_release(inode, file);
412 }
413
414 static unsigned mounts_poll(struct file *file, poll_table *wait)
415 {
416 struct proc_mounts *p = file->private_data;
417 struct mnt_namespace *ns = p->m.private;
418 unsigned res = 0;
419
420 poll_wait(file, &ns->poll, wait);
421
422 spin_lock(&vfsmount_lock);
423 if (p->event != ns->event) {
424 p->event = ns->event;
425 res = POLLERR;
426 }
427 spin_unlock(&vfsmount_lock);
428
429 return res;
430 }
431
432 static const struct file_operations proc_mounts_operations = {
433 .open = mounts_open,
434 .read = seq_read,
435 .llseek = seq_lseek,
436 .release = mounts_release,
437 .poll = mounts_poll,
438 };
439
440 extern struct seq_operations mountstats_op;
441 static int mountstats_open(struct inode *inode, struct file *file)
442 {
443 int ret = seq_open(file, &mountstats_op);
444
445 if (!ret) {
446 struct seq_file *m = file->private_data;
447 struct mnt_namespace *mnt_ns = NULL;
448 struct task_struct *task = get_proc_task(inode);
449
450 if (task) {
451 task_lock(task);
452 if (task->nsproxy)
453 mnt_ns = task->nsproxy->mnt_ns;
454 if (mnt_ns)
455 get_mnt_ns(mnt_ns);
456 task_unlock(task);
457 put_task_struct(task);
458 }
459
460 if (mnt_ns)
461 m->private = mnt_ns;
462 else {
463 seq_release(inode, file);
464 ret = -EINVAL;
465 }
466 }
467 return ret;
468 }
469
470 static const struct file_operations proc_mountstats_operations = {
471 .open = mountstats_open,
472 .read = seq_read,
473 .llseek = seq_lseek,
474 .release = mounts_release,
475 };
476
477 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
478
479 static ssize_t proc_info_read(struct file * file, char __user * buf,
480 size_t count, loff_t *ppos)
481 {
482 struct inode * inode = file->f_path.dentry->d_inode;
483 unsigned long page;
484 ssize_t length;
485 struct task_struct *task = get_proc_task(inode);
486
487 length = -ESRCH;
488 if (!task)
489 goto out_no_task;
490
491 if (count > PROC_BLOCK_SIZE)
492 count = PROC_BLOCK_SIZE;
493
494 length = -ENOMEM;
495 if (!(page = __get_free_page(GFP_KERNEL)))
496 goto out;
497
498 length = PROC_I(inode)->op.proc_read(task, (char*)page);
499
500 if (length >= 0)
501 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
502 free_page(page);
503 out:
504 put_task_struct(task);
505 out_no_task:
506 return length;
507 }
508
509 static const struct file_operations proc_info_file_operations = {
510 .read = proc_info_read,
511 };
512
513 static int mem_open(struct inode* inode, struct file* file)
514 {
515 file->private_data = (void*)((long)current->self_exec_id);
516 return 0;
517 }
518
519 static ssize_t mem_read(struct file * file, char __user * buf,
520 size_t count, loff_t *ppos)
521 {
522 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
523 char *page;
524 unsigned long src = *ppos;
525 int ret = -ESRCH;
526 struct mm_struct *mm;
527
528 if (!task)
529 goto out_no_task;
530
531 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
532 goto out;
533
534 ret = -ENOMEM;
535 page = (char *)__get_free_page(GFP_USER);
536 if (!page)
537 goto out;
538
539 ret = 0;
540
541 mm = get_task_mm(task);
542 if (!mm)
543 goto out_free;
544
545 ret = -EIO;
546
547 if (file->private_data != (void*)((long)current->self_exec_id))
548 goto out_put;
549
550 ret = 0;
551
552 while (count > 0) {
553 int this_len, retval;
554
555 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
556 retval = access_process_vm(task, src, page, this_len, 0);
557 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
558 if (!ret)
559 ret = -EIO;
560 break;
561 }
562
563 if (copy_to_user(buf, page, retval)) {
564 ret = -EFAULT;
565 break;
566 }
567
568 ret += retval;
569 src += retval;
570 buf += retval;
571 count -= retval;
572 }
573 *ppos = src;
574
575 out_put:
576 mmput(mm);
577 out_free:
578 free_page((unsigned long) page);
579 out:
580 put_task_struct(task);
581 out_no_task:
582 return ret;
583 }
584
585 #define mem_write NULL
586
587 #ifndef mem_write
588 /* This is a security hazard */
589 static ssize_t mem_write(struct file * file, const char __user *buf,
590 size_t count, loff_t *ppos)
591 {
592 int copied;
593 char *page;
594 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
595 unsigned long dst = *ppos;
596
597 copied = -ESRCH;
598 if (!task)
599 goto out_no_task;
600
601 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
602 goto out;
603
604 copied = -ENOMEM;
605 page = (char *)__get_free_page(GFP_USER);
606 if (!page)
607 goto out;
608
609 copied = 0;
610 while (count > 0) {
611 int this_len, retval;
612
613 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
614 if (copy_from_user(page, buf, this_len)) {
615 copied = -EFAULT;
616 break;
617 }
618 retval = access_process_vm(task, dst, page, this_len, 1);
619 if (!retval) {
620 if (!copied)
621 copied = -EIO;
622 break;
623 }
624 copied += retval;
625 buf += retval;
626 dst += retval;
627 count -= retval;
628 }
629 *ppos = dst;
630 free_page((unsigned long) page);
631 out:
632 put_task_struct(task);
633 out_no_task:
634 return copied;
635 }
636 #endif
637
638 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
639 {
640 switch (orig) {
641 case 0:
642 file->f_pos = offset;
643 break;
644 case 1:
645 file->f_pos += offset;
646 break;
647 default:
648 return -EINVAL;
649 }
650 force_successful_syscall_return();
651 return file->f_pos;
652 }
653
654 static const struct file_operations proc_mem_operations = {
655 .llseek = mem_lseek,
656 .read = mem_read,
657 .write = mem_write,
658 .open = mem_open,
659 };
660
661 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
662 size_t count, loff_t *ppos)
663 {
664 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
665 char buffer[PROC_NUMBUF];
666 size_t len;
667 int oom_adjust;
668
669 if (!task)
670 return -ESRCH;
671 oom_adjust = task->oomkilladj;
672 put_task_struct(task);
673
674 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
675
676 return simple_read_from_buffer(buf, count, ppos, buffer, len);
677 }
678
679 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
680 size_t count, loff_t *ppos)
681 {
682 struct task_struct *task;
683 char buffer[PROC_NUMBUF], *end;
684 int oom_adjust;
685
686 memset(buffer, 0, sizeof(buffer));
687 if (count > sizeof(buffer) - 1)
688 count = sizeof(buffer) - 1;
689 if (copy_from_user(buffer, buf, count))
690 return -EFAULT;
691 oom_adjust = simple_strtol(buffer, &end, 0);
692 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
693 oom_adjust != OOM_DISABLE)
694 return -EINVAL;
695 if (*end == '\n')
696 end++;
697 task = get_proc_task(file->f_path.dentry->d_inode);
698 if (!task)
699 return -ESRCH;
700 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
701 put_task_struct(task);
702 return -EACCES;
703 }
704 task->oomkilladj = oom_adjust;
705 put_task_struct(task);
706 if (end - buffer == 0)
707 return -EIO;
708 return end - buffer;
709 }
710
711 static const struct file_operations proc_oom_adjust_operations = {
712 .read = oom_adjust_read,
713 .write = oom_adjust_write,
714 };
715
716 #ifdef CONFIG_MMU
717 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
718 size_t count, loff_t *ppos)
719 {
720 struct task_struct *task;
721 char buffer[PROC_NUMBUF], *end;
722 struct mm_struct *mm;
723
724 memset(buffer, 0, sizeof(buffer));
725 if (count > sizeof(buffer) - 1)
726 count = sizeof(buffer) - 1;
727 if (copy_from_user(buffer, buf, count))
728 return -EFAULT;
729 if (!simple_strtol(buffer, &end, 0))
730 return -EINVAL;
731 if (*end == '\n')
732 end++;
733 task = get_proc_task(file->f_path.dentry->d_inode);
734 if (!task)
735 return -ESRCH;
736 mm = get_task_mm(task);
737 if (mm) {
738 clear_refs_smap(mm);
739 mmput(mm);
740 }
741 put_task_struct(task);
742 if (end - buffer == 0)
743 return -EIO;
744 return end - buffer;
745 }
746
747 static struct file_operations proc_clear_refs_operations = {
748 .write = clear_refs_write,
749 };
750 #endif
751
752 #ifdef CONFIG_AUDITSYSCALL
753 #define TMPBUFLEN 21
754 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
755 size_t count, loff_t *ppos)
756 {
757 struct inode * inode = file->f_path.dentry->d_inode;
758 struct task_struct *task = get_proc_task(inode);
759 ssize_t length;
760 char tmpbuf[TMPBUFLEN];
761
762 if (!task)
763 return -ESRCH;
764 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
765 audit_get_loginuid(task->audit_context));
766 put_task_struct(task);
767 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
768 }
769
770 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
771 size_t count, loff_t *ppos)
772 {
773 struct inode * inode = file->f_path.dentry->d_inode;
774 char *page, *tmp;
775 ssize_t length;
776 uid_t loginuid;
777
778 if (!capable(CAP_AUDIT_CONTROL))
779 return -EPERM;
780
781 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
782 return -EPERM;
783
784 if (count >= PAGE_SIZE)
785 count = PAGE_SIZE - 1;
786
787 if (*ppos != 0) {
788 /* No partial writes. */
789 return -EINVAL;
790 }
791 page = (char*)__get_free_page(GFP_USER);
792 if (!page)
793 return -ENOMEM;
794 length = -EFAULT;
795 if (copy_from_user(page, buf, count))
796 goto out_free_page;
797
798 page[count] = '\0';
799 loginuid = simple_strtoul(page, &tmp, 10);
800 if (tmp == page) {
801 length = -EINVAL;
802 goto out_free_page;
803
804 }
805 length = audit_set_loginuid(current, loginuid);
806 if (likely(length == 0))
807 length = count;
808
809 out_free_page:
810 free_page((unsigned long) page);
811 return length;
812 }
813
814 static const struct file_operations proc_loginuid_operations = {
815 .read = proc_loginuid_read,
816 .write = proc_loginuid_write,
817 };
818 #endif
819
820 #ifdef CONFIG_FAULT_INJECTION
821 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
822 size_t count, loff_t *ppos)
823 {
824 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
825 char buffer[PROC_NUMBUF];
826 size_t len;
827 int make_it_fail;
828
829 if (!task)
830 return -ESRCH;
831 make_it_fail = task->make_it_fail;
832 put_task_struct(task);
833
834 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
835
836 return simple_read_from_buffer(buf, count, ppos, buffer, len);
837 }
838
839 static ssize_t proc_fault_inject_write(struct file * file,
840 const char __user * buf, size_t count, loff_t *ppos)
841 {
842 struct task_struct *task;
843 char buffer[PROC_NUMBUF], *end;
844 int make_it_fail;
845
846 if (!capable(CAP_SYS_RESOURCE))
847 return -EPERM;
848 memset(buffer, 0, sizeof(buffer));
849 if (count > sizeof(buffer) - 1)
850 count = sizeof(buffer) - 1;
851 if (copy_from_user(buffer, buf, count))
852 return -EFAULT;
853 make_it_fail = simple_strtol(buffer, &end, 0);
854 if (*end == '\n')
855 end++;
856 task = get_proc_task(file->f_dentry->d_inode);
857 if (!task)
858 return -ESRCH;
859 task->make_it_fail = make_it_fail;
860 put_task_struct(task);
861 if (end - buffer == 0)
862 return -EIO;
863 return end - buffer;
864 }
865
866 static const struct file_operations proc_fault_inject_operations = {
867 .read = proc_fault_inject_read,
868 .write = proc_fault_inject_write,
869 };
870 #endif
871
872 #ifdef CONFIG_SCHED_DEBUG
873 /*
874 * Print out various scheduling related per-task fields:
875 */
876 static int sched_show(struct seq_file *m, void *v)
877 {
878 struct inode *inode = m->private;
879 struct task_struct *p;
880
881 WARN_ON(!inode);
882
883 p = get_proc_task(inode);
884 if (!p)
885 return -ESRCH;
886 proc_sched_show_task(p, m);
887
888 put_task_struct(p);
889
890 return 0;
891 }
892
893 static ssize_t
894 sched_write(struct file *file, const char __user *buf,
895 size_t count, loff_t *offset)
896 {
897 struct inode *inode = file->f_path.dentry->d_inode;
898 struct task_struct *p;
899
900 WARN_ON(!inode);
901
902 p = get_proc_task(inode);
903 if (!p)
904 return -ESRCH;
905 proc_sched_set_task(p);
906
907 put_task_struct(p);
908
909 return count;
910 }
911
912 static int sched_open(struct inode *inode, struct file *filp)
913 {
914 int ret;
915
916 ret = single_open(filp, sched_show, NULL);
917 if (!ret) {
918 struct seq_file *m = filp->private_data;
919
920 m->private = inode;
921 }
922 return ret;
923 }
924
925 static const struct file_operations proc_pid_sched_operations = {
926 .open = sched_open,
927 .read = seq_read,
928 .write = sched_write,
929 .llseek = seq_lseek,
930 .release = single_release,
931 };
932
933 #endif
934
935 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
936 {
937 struct inode *inode = dentry->d_inode;
938 int error = -EACCES;
939
940 /* We don't need a base pointer in the /proc filesystem */
941 path_release(nd);
942
943 /* Are we allowed to snoop on the tasks file descriptors? */
944 if (!proc_fd_access_allowed(inode))
945 goto out;
946
947 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
948 nd->last_type = LAST_BIND;
949 out:
950 return ERR_PTR(error);
951 }
952
953 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
954 char __user *buffer, int buflen)
955 {
956 struct inode * inode;
957 char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
958 int len;
959
960 if (!tmp)
961 return -ENOMEM;
962
963 inode = dentry->d_inode;
964 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
965 len = PTR_ERR(path);
966 if (IS_ERR(path))
967 goto out;
968 len = tmp + PAGE_SIZE - 1 - path;
969
970 if (len > buflen)
971 len = buflen;
972 if (copy_to_user(buffer, path, len))
973 len = -EFAULT;
974 out:
975 free_page((unsigned long)tmp);
976 return len;
977 }
978
979 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
980 {
981 int error = -EACCES;
982 struct inode *inode = dentry->d_inode;
983 struct dentry *de;
984 struct vfsmount *mnt = NULL;
985
986 /* Are we allowed to snoop on the tasks file descriptors? */
987 if (!proc_fd_access_allowed(inode))
988 goto out;
989
990 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
991 if (error)
992 goto out;
993
994 error = do_proc_readlink(de, mnt, buffer, buflen);
995 dput(de);
996 mntput(mnt);
997 out:
998 return error;
999 }
1000
1001 static const struct inode_operations proc_pid_link_inode_operations = {
1002 .readlink = proc_pid_readlink,
1003 .follow_link = proc_pid_follow_link,
1004 .setattr = proc_setattr,
1005 };
1006
1007
1008 /* building an inode */
1009
1010 static int task_dumpable(struct task_struct *task)
1011 {
1012 int dumpable = 0;
1013 struct mm_struct *mm;
1014
1015 task_lock(task);
1016 mm = task->mm;
1017 if (mm)
1018 dumpable = get_dumpable(mm);
1019 task_unlock(task);
1020 if(dumpable == 1)
1021 return 1;
1022 return 0;
1023 }
1024
1025
1026 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1027 {
1028 struct inode * inode;
1029 struct proc_inode *ei;
1030
1031 /* We need a new inode */
1032
1033 inode = new_inode(sb);
1034 if (!inode)
1035 goto out;
1036
1037 /* Common stuff */
1038 ei = PROC_I(inode);
1039 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1040 inode->i_op = &proc_def_inode_operations;
1041
1042 /*
1043 * grab the reference to task.
1044 */
1045 ei->pid = get_task_pid(task, PIDTYPE_PID);
1046 if (!ei->pid)
1047 goto out_unlock;
1048
1049 inode->i_uid = 0;
1050 inode->i_gid = 0;
1051 if (task_dumpable(task)) {
1052 inode->i_uid = task->euid;
1053 inode->i_gid = task->egid;
1054 }
1055 security_task_to_inode(task, inode);
1056
1057 out:
1058 return inode;
1059
1060 out_unlock:
1061 iput(inode);
1062 return NULL;
1063 }
1064
1065 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1066 {
1067 struct inode *inode = dentry->d_inode;
1068 struct task_struct *task;
1069 generic_fillattr(inode, stat);
1070
1071 rcu_read_lock();
1072 stat->uid = 0;
1073 stat->gid = 0;
1074 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1075 if (task) {
1076 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1077 task_dumpable(task)) {
1078 stat->uid = task->euid;
1079 stat->gid = task->egid;
1080 }
1081 }
1082 rcu_read_unlock();
1083 return 0;
1084 }
1085
1086 /* dentry stuff */
1087
1088 /*
1089 * Exceptional case: normally we are not allowed to unhash a busy
1090 * directory. In this case, however, we can do it - no aliasing problems
1091 * due to the way we treat inodes.
1092 *
1093 * Rewrite the inode's ownerships here because the owning task may have
1094 * performed a setuid(), etc.
1095 *
1096 * Before the /proc/pid/status file was created the only way to read
1097 * the effective uid of a /process was to stat /proc/pid. Reading
1098 * /proc/pid/status is slow enough that procps and other packages
1099 * kept stating /proc/pid. To keep the rules in /proc simple I have
1100 * made this apply to all per process world readable and executable
1101 * directories.
1102 */
1103 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1104 {
1105 struct inode *inode = dentry->d_inode;
1106 struct task_struct *task = get_proc_task(inode);
1107 if (task) {
1108 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1109 task_dumpable(task)) {
1110 inode->i_uid = task->euid;
1111 inode->i_gid = task->egid;
1112 } else {
1113 inode->i_uid = 0;
1114 inode->i_gid = 0;
1115 }
1116 inode->i_mode &= ~(S_ISUID | S_ISGID);
1117 security_task_to_inode(task, inode);
1118 put_task_struct(task);
1119 return 1;
1120 }
1121 d_drop(dentry);
1122 return 0;
1123 }
1124
1125 static int pid_delete_dentry(struct dentry * dentry)
1126 {
1127 /* Is the task we represent dead?
1128 * If so, then don't put the dentry on the lru list,
1129 * kill it immediately.
1130 */
1131 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1132 }
1133
1134 static struct dentry_operations pid_dentry_operations =
1135 {
1136 .d_revalidate = pid_revalidate,
1137 .d_delete = pid_delete_dentry,
1138 };
1139
1140 /* Lookups */
1141
1142 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1143 struct task_struct *, const void *);
1144
1145 /*
1146 * Fill a directory entry.
1147 *
1148 * If possible create the dcache entry and derive our inode number and
1149 * file type from dcache entry.
1150 *
1151 * Since all of the proc inode numbers are dynamically generated, the inode
1152 * numbers do not exist until the inode is cache. This means creating the
1153 * the dcache entry in readdir is necessary to keep the inode numbers
1154 * reported by readdir in sync with the inode numbers reported
1155 * by stat.
1156 */
1157 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1158 char *name, int len,
1159 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1160 {
1161 struct dentry *child, *dir = filp->f_path.dentry;
1162 struct inode *inode;
1163 struct qstr qname;
1164 ino_t ino = 0;
1165 unsigned type = DT_UNKNOWN;
1166
1167 qname.name = name;
1168 qname.len = len;
1169 qname.hash = full_name_hash(name, len);
1170
1171 child = d_lookup(dir, &qname);
1172 if (!child) {
1173 struct dentry *new;
1174 new = d_alloc(dir, &qname);
1175 if (new) {
1176 child = instantiate(dir->d_inode, new, task, ptr);
1177 if (child)
1178 dput(new);
1179 else
1180 child = new;
1181 }
1182 }
1183 if (!child || IS_ERR(child) || !child->d_inode)
1184 goto end_instantiate;
1185 inode = child->d_inode;
1186 if (inode) {
1187 ino = inode->i_ino;
1188 type = inode->i_mode >> 12;
1189 }
1190 dput(child);
1191 end_instantiate:
1192 if (!ino)
1193 ino = find_inode_number(dir, &qname);
1194 if (!ino)
1195 ino = 1;
1196 return filldir(dirent, name, len, filp->f_pos, ino, type);
1197 }
1198
1199 static unsigned name_to_int(struct dentry *dentry)
1200 {
1201 const char *name = dentry->d_name.name;
1202 int len = dentry->d_name.len;
1203 unsigned n = 0;
1204
1205 if (len > 1 && *name == '0')
1206 goto out;
1207 while (len-- > 0) {
1208 unsigned c = *name++ - '0';
1209 if (c > 9)
1210 goto out;
1211 if (n >= (~0U-9)/10)
1212 goto out;
1213 n *= 10;
1214 n += c;
1215 }
1216 return n;
1217 out:
1218 return ~0U;
1219 }
1220
1221 #define PROC_FDINFO_MAX 64
1222
1223 static int proc_fd_info(struct inode *inode, struct dentry **dentry,
1224 struct vfsmount **mnt, char *info)
1225 {
1226 struct task_struct *task = get_proc_task(inode);
1227 struct files_struct *files = NULL;
1228 struct file *file;
1229 int fd = proc_fd(inode);
1230
1231 if (task) {
1232 files = get_files_struct(task);
1233 put_task_struct(task);
1234 }
1235 if (files) {
1236 /*
1237 * We are not taking a ref to the file structure, so we must
1238 * hold ->file_lock.
1239 */
1240 spin_lock(&files->file_lock);
1241 file = fcheck_files(files, fd);
1242 if (file) {
1243 if (mnt)
1244 *mnt = mntget(file->f_path.mnt);
1245 if (dentry)
1246 *dentry = dget(file->f_path.dentry);
1247 if (info)
1248 snprintf(info, PROC_FDINFO_MAX,
1249 "pos:\t%lli\n"
1250 "flags:\t0%o\n",
1251 (long long) file->f_pos,
1252 file->f_flags);
1253 spin_unlock(&files->file_lock);
1254 put_files_struct(files);
1255 return 0;
1256 }
1257 spin_unlock(&files->file_lock);
1258 put_files_struct(files);
1259 }
1260 return -ENOENT;
1261 }
1262
1263 static int proc_fd_link(struct inode *inode, struct dentry **dentry,
1264 struct vfsmount **mnt)
1265 {
1266 return proc_fd_info(inode, dentry, mnt, NULL);
1267 }
1268
1269 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1270 {
1271 struct inode *inode = dentry->d_inode;
1272 struct task_struct *task = get_proc_task(inode);
1273 int fd = proc_fd(inode);
1274 struct files_struct *files;
1275
1276 if (task) {
1277 files = get_files_struct(task);
1278 if (files) {
1279 rcu_read_lock();
1280 if (fcheck_files(files, fd)) {
1281 rcu_read_unlock();
1282 put_files_struct(files);
1283 if (task_dumpable(task)) {
1284 inode->i_uid = task->euid;
1285 inode->i_gid = task->egid;
1286 } else {
1287 inode->i_uid = 0;
1288 inode->i_gid = 0;
1289 }
1290 inode->i_mode &= ~(S_ISUID | S_ISGID);
1291 security_task_to_inode(task, inode);
1292 put_task_struct(task);
1293 return 1;
1294 }
1295 rcu_read_unlock();
1296 put_files_struct(files);
1297 }
1298 put_task_struct(task);
1299 }
1300 d_drop(dentry);
1301 return 0;
1302 }
1303
1304 static struct dentry_operations tid_fd_dentry_operations =
1305 {
1306 .d_revalidate = tid_fd_revalidate,
1307 .d_delete = pid_delete_dentry,
1308 };
1309
1310 static struct dentry *proc_fd_instantiate(struct inode *dir,
1311 struct dentry *dentry, struct task_struct *task, const void *ptr)
1312 {
1313 unsigned fd = *(const unsigned *)ptr;
1314 struct file *file;
1315 struct files_struct *files;
1316 struct inode *inode;
1317 struct proc_inode *ei;
1318 struct dentry *error = ERR_PTR(-ENOENT);
1319
1320 inode = proc_pid_make_inode(dir->i_sb, task);
1321 if (!inode)
1322 goto out;
1323 ei = PROC_I(inode);
1324 ei->fd = fd;
1325 files = get_files_struct(task);
1326 if (!files)
1327 goto out_iput;
1328 inode->i_mode = S_IFLNK;
1329
1330 /*
1331 * We are not taking a ref to the file structure, so we must
1332 * hold ->file_lock.
1333 */
1334 spin_lock(&files->file_lock);
1335 file = fcheck_files(files, fd);
1336 if (!file)
1337 goto out_unlock;
1338 if (file->f_mode & 1)
1339 inode->i_mode |= S_IRUSR | S_IXUSR;
1340 if (file->f_mode & 2)
1341 inode->i_mode |= S_IWUSR | S_IXUSR;
1342 spin_unlock(&files->file_lock);
1343 put_files_struct(files);
1344
1345 inode->i_op = &proc_pid_link_inode_operations;
1346 inode->i_size = 64;
1347 ei->op.proc_get_link = proc_fd_link;
1348 dentry->d_op = &tid_fd_dentry_operations;
1349 d_add(dentry, inode);
1350 /* Close the race of the process dying before we return the dentry */
1351 if (tid_fd_revalidate(dentry, NULL))
1352 error = NULL;
1353
1354 out:
1355 return error;
1356 out_unlock:
1357 spin_unlock(&files->file_lock);
1358 put_files_struct(files);
1359 out_iput:
1360 iput(inode);
1361 goto out;
1362 }
1363
1364 static struct dentry *proc_lookupfd_common(struct inode *dir,
1365 struct dentry *dentry,
1366 instantiate_t instantiate)
1367 {
1368 struct task_struct *task = get_proc_task(dir);
1369 unsigned fd = name_to_int(dentry);
1370 struct dentry *result = ERR_PTR(-ENOENT);
1371
1372 if (!task)
1373 goto out_no_task;
1374 if (fd == ~0U)
1375 goto out;
1376
1377 result = instantiate(dir, dentry, task, &fd);
1378 out:
1379 put_task_struct(task);
1380 out_no_task:
1381 return result;
1382 }
1383
1384 static int proc_readfd_common(struct file * filp, void * dirent,
1385 filldir_t filldir, instantiate_t instantiate)
1386 {
1387 struct dentry *dentry = filp->f_path.dentry;
1388 struct inode *inode = dentry->d_inode;
1389 struct task_struct *p = get_proc_task(inode);
1390 unsigned int fd, tid, ino;
1391 int retval;
1392 struct files_struct * files;
1393 struct fdtable *fdt;
1394
1395 retval = -ENOENT;
1396 if (!p)
1397 goto out_no_task;
1398 retval = 0;
1399 tid = p->pid;
1400
1401 fd = filp->f_pos;
1402 switch (fd) {
1403 case 0:
1404 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1405 goto out;
1406 filp->f_pos++;
1407 case 1:
1408 ino = parent_ino(dentry);
1409 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1410 goto out;
1411 filp->f_pos++;
1412 default:
1413 files = get_files_struct(p);
1414 if (!files)
1415 goto out;
1416 rcu_read_lock();
1417 fdt = files_fdtable(files);
1418 for (fd = filp->f_pos-2;
1419 fd < fdt->max_fds;
1420 fd++, filp->f_pos++) {
1421 char name[PROC_NUMBUF];
1422 int len;
1423
1424 if (!fcheck_files(files, fd))
1425 continue;
1426 rcu_read_unlock();
1427
1428 len = snprintf(name, sizeof(name), "%d", fd);
1429 if (proc_fill_cache(filp, dirent, filldir,
1430 name, len, instantiate,
1431 p, &fd) < 0) {
1432 rcu_read_lock();
1433 break;
1434 }
1435 rcu_read_lock();
1436 }
1437 rcu_read_unlock();
1438 put_files_struct(files);
1439 }
1440 out:
1441 put_task_struct(p);
1442 out_no_task:
1443 return retval;
1444 }
1445
1446 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1447 struct nameidata *nd)
1448 {
1449 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1450 }
1451
1452 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1453 {
1454 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1455 }
1456
1457 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1458 size_t len, loff_t *ppos)
1459 {
1460 char tmp[PROC_FDINFO_MAX];
1461 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
1462 if (!err)
1463 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1464 return err;
1465 }
1466
1467 static const struct file_operations proc_fdinfo_file_operations = {
1468 .open = nonseekable_open,
1469 .read = proc_fdinfo_read,
1470 };
1471
1472 static const struct file_operations proc_fd_operations = {
1473 .read = generic_read_dir,
1474 .readdir = proc_readfd,
1475 };
1476
1477 /*
1478 * /proc/pid/fd needs a special permission handler so that a process can still
1479 * access /proc/self/fd after it has executed a setuid().
1480 */
1481 static int proc_fd_permission(struct inode *inode, int mask,
1482 struct nameidata *nd)
1483 {
1484 int rv;
1485
1486 rv = generic_permission(inode, mask, NULL);
1487 if (rv == 0)
1488 return 0;
1489 if (task_pid(current) == proc_pid(inode))
1490 rv = 0;
1491 return rv;
1492 }
1493
1494 /*
1495 * proc directories can do almost nothing..
1496 */
1497 static const struct inode_operations proc_fd_inode_operations = {
1498 .lookup = proc_lookupfd,
1499 .permission = proc_fd_permission,
1500 .setattr = proc_setattr,
1501 };
1502
1503 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1504 struct dentry *dentry, struct task_struct *task, const void *ptr)
1505 {
1506 unsigned fd = *(unsigned *)ptr;
1507 struct inode *inode;
1508 struct proc_inode *ei;
1509 struct dentry *error = ERR_PTR(-ENOENT);
1510
1511 inode = proc_pid_make_inode(dir->i_sb, task);
1512 if (!inode)
1513 goto out;
1514 ei = PROC_I(inode);
1515 ei->fd = fd;
1516 inode->i_mode = S_IFREG | S_IRUSR;
1517 inode->i_fop = &proc_fdinfo_file_operations;
1518 dentry->d_op = &tid_fd_dentry_operations;
1519 d_add(dentry, inode);
1520 /* Close the race of the process dying before we return the dentry */
1521 if (tid_fd_revalidate(dentry, NULL))
1522 error = NULL;
1523
1524 out:
1525 return error;
1526 }
1527
1528 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1529 struct dentry *dentry,
1530 struct nameidata *nd)
1531 {
1532 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1533 }
1534
1535 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1536 {
1537 return proc_readfd_common(filp, dirent, filldir,
1538 proc_fdinfo_instantiate);
1539 }
1540
1541 static const struct file_operations proc_fdinfo_operations = {
1542 .read = generic_read_dir,
1543 .readdir = proc_readfdinfo,
1544 };
1545
1546 /*
1547 * proc directories can do almost nothing..
1548 */
1549 static const struct inode_operations proc_fdinfo_inode_operations = {
1550 .lookup = proc_lookupfdinfo,
1551 .setattr = proc_setattr,
1552 };
1553
1554
1555 static struct dentry *proc_pident_instantiate(struct inode *dir,
1556 struct dentry *dentry, struct task_struct *task, const void *ptr)
1557 {
1558 const struct pid_entry *p = ptr;
1559 struct inode *inode;
1560 struct proc_inode *ei;
1561 struct dentry *error = ERR_PTR(-EINVAL);
1562
1563 inode = proc_pid_make_inode(dir->i_sb, task);
1564 if (!inode)
1565 goto out;
1566
1567 ei = PROC_I(inode);
1568 inode->i_mode = p->mode;
1569 if (S_ISDIR(inode->i_mode))
1570 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1571 if (p->iop)
1572 inode->i_op = p->iop;
1573 if (p->fop)
1574 inode->i_fop = p->fop;
1575 ei->op = p->op;
1576 dentry->d_op = &pid_dentry_operations;
1577 d_add(dentry, inode);
1578 /* Close the race of the process dying before we return the dentry */
1579 if (pid_revalidate(dentry, NULL))
1580 error = NULL;
1581 out:
1582 return error;
1583 }
1584
1585 static struct dentry *proc_pident_lookup(struct inode *dir,
1586 struct dentry *dentry,
1587 const struct pid_entry *ents,
1588 unsigned int nents)
1589 {
1590 struct inode *inode;
1591 struct dentry *error;
1592 struct task_struct *task = get_proc_task(dir);
1593 const struct pid_entry *p, *last;
1594
1595 error = ERR_PTR(-ENOENT);
1596 inode = NULL;
1597
1598 if (!task)
1599 goto out_no_task;
1600
1601 /*
1602 * Yes, it does not scale. And it should not. Don't add
1603 * new entries into /proc/<tgid>/ without very good reasons.
1604 */
1605 last = &ents[nents - 1];
1606 for (p = ents; p <= last; p++) {
1607 if (p->len != dentry->d_name.len)
1608 continue;
1609 if (!memcmp(dentry->d_name.name, p->name, p->len))
1610 break;
1611 }
1612 if (p > last)
1613 goto out;
1614
1615 error = proc_pident_instantiate(dir, dentry, task, p);
1616 out:
1617 put_task_struct(task);
1618 out_no_task:
1619 return error;
1620 }
1621
1622 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1623 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1624 {
1625 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1626 proc_pident_instantiate, task, p);
1627 }
1628
1629 static int proc_pident_readdir(struct file *filp,
1630 void *dirent, filldir_t filldir,
1631 const struct pid_entry *ents, unsigned int nents)
1632 {
1633 int i;
1634 int pid;
1635 struct dentry *dentry = filp->f_path.dentry;
1636 struct inode *inode = dentry->d_inode;
1637 struct task_struct *task = get_proc_task(inode);
1638 const struct pid_entry *p, *last;
1639 ino_t ino;
1640 int ret;
1641
1642 ret = -ENOENT;
1643 if (!task)
1644 goto out_no_task;
1645
1646 ret = 0;
1647 pid = task->pid;
1648 i = filp->f_pos;
1649 switch (i) {
1650 case 0:
1651 ino = inode->i_ino;
1652 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1653 goto out;
1654 i++;
1655 filp->f_pos++;
1656 /* fall through */
1657 case 1:
1658 ino = parent_ino(dentry);
1659 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1660 goto out;
1661 i++;
1662 filp->f_pos++;
1663 /* fall through */
1664 default:
1665 i -= 2;
1666 if (i >= nents) {
1667 ret = 1;
1668 goto out;
1669 }
1670 p = ents + i;
1671 last = &ents[nents - 1];
1672 while (p <= last) {
1673 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
1674 goto out;
1675 filp->f_pos++;
1676 p++;
1677 }
1678 }
1679
1680 ret = 1;
1681 out:
1682 put_task_struct(task);
1683 out_no_task:
1684 return ret;
1685 }
1686
1687 #ifdef CONFIG_SECURITY
1688 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1689 size_t count, loff_t *ppos)
1690 {
1691 struct inode * inode = file->f_path.dentry->d_inode;
1692 char *p = NULL;
1693 ssize_t length;
1694 struct task_struct *task = get_proc_task(inode);
1695
1696 if (!task)
1697 return -ESRCH;
1698
1699 length = security_getprocattr(task,
1700 (char*)file->f_path.dentry->d_name.name,
1701 &p);
1702 put_task_struct(task);
1703 if (length > 0)
1704 length = simple_read_from_buffer(buf, count, ppos, p, length);
1705 kfree(p);
1706 return length;
1707 }
1708
1709 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1710 size_t count, loff_t *ppos)
1711 {
1712 struct inode * inode = file->f_path.dentry->d_inode;
1713 char *page;
1714 ssize_t length;
1715 struct task_struct *task = get_proc_task(inode);
1716
1717 length = -ESRCH;
1718 if (!task)
1719 goto out_no_task;
1720 if (count > PAGE_SIZE)
1721 count = PAGE_SIZE;
1722
1723 /* No partial writes. */
1724 length = -EINVAL;
1725 if (*ppos != 0)
1726 goto out;
1727
1728 length = -ENOMEM;
1729 page = (char*)__get_free_page(GFP_USER);
1730 if (!page)
1731 goto out;
1732
1733 length = -EFAULT;
1734 if (copy_from_user(page, buf, count))
1735 goto out_free;
1736
1737 length = security_setprocattr(task,
1738 (char*)file->f_path.dentry->d_name.name,
1739 (void*)page, count);
1740 out_free:
1741 free_page((unsigned long) page);
1742 out:
1743 put_task_struct(task);
1744 out_no_task:
1745 return length;
1746 }
1747
1748 static const struct file_operations proc_pid_attr_operations = {
1749 .read = proc_pid_attr_read,
1750 .write = proc_pid_attr_write,
1751 };
1752
1753 static const struct pid_entry attr_dir_stuff[] = {
1754 REG("current", S_IRUGO|S_IWUGO, pid_attr),
1755 REG("prev", S_IRUGO, pid_attr),
1756 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
1757 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
1758 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
1759 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
1760 };
1761
1762 static int proc_attr_dir_readdir(struct file * filp,
1763 void * dirent, filldir_t filldir)
1764 {
1765 return proc_pident_readdir(filp,dirent,filldir,
1766 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
1767 }
1768
1769 static const struct file_operations proc_attr_dir_operations = {
1770 .read = generic_read_dir,
1771 .readdir = proc_attr_dir_readdir,
1772 };
1773
1774 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
1775 struct dentry *dentry, struct nameidata *nd)
1776 {
1777 return proc_pident_lookup(dir, dentry,
1778 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
1779 }
1780
1781 static const struct inode_operations proc_attr_dir_inode_operations = {
1782 .lookup = proc_attr_dir_lookup,
1783 .getattr = pid_getattr,
1784 .setattr = proc_setattr,
1785 };
1786
1787 #endif
1788
1789 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1790 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
1791 size_t count, loff_t *ppos)
1792 {
1793 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1794 struct mm_struct *mm;
1795 char buffer[PROC_NUMBUF];
1796 size_t len;
1797 int ret;
1798
1799 if (!task)
1800 return -ESRCH;
1801
1802 ret = 0;
1803 mm = get_task_mm(task);
1804 if (mm) {
1805 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
1806 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
1807 MMF_DUMP_FILTER_SHIFT));
1808 mmput(mm);
1809 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
1810 }
1811
1812 put_task_struct(task);
1813
1814 return ret;
1815 }
1816
1817 static ssize_t proc_coredump_filter_write(struct file *file,
1818 const char __user *buf,
1819 size_t count,
1820 loff_t *ppos)
1821 {
1822 struct task_struct *task;
1823 struct mm_struct *mm;
1824 char buffer[PROC_NUMBUF], *end;
1825 unsigned int val;
1826 int ret;
1827 int i;
1828 unsigned long mask;
1829
1830 ret = -EFAULT;
1831 memset(buffer, 0, sizeof(buffer));
1832 if (count > sizeof(buffer) - 1)
1833 count = sizeof(buffer) - 1;
1834 if (copy_from_user(buffer, buf, count))
1835 goto out_no_task;
1836
1837 ret = -EINVAL;
1838 val = (unsigned int)simple_strtoul(buffer, &end, 0);
1839 if (*end == '\n')
1840 end++;
1841 if (end - buffer == 0)
1842 goto out_no_task;
1843
1844 ret = -ESRCH;
1845 task = get_proc_task(file->f_dentry->d_inode);
1846 if (!task)
1847 goto out_no_task;
1848
1849 ret = end - buffer;
1850 mm = get_task_mm(task);
1851 if (!mm)
1852 goto out_no_mm;
1853
1854 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
1855 if (val & mask)
1856 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
1857 else
1858 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
1859 }
1860
1861 mmput(mm);
1862 out_no_mm:
1863 put_task_struct(task);
1864 out_no_task:
1865 return ret;
1866 }
1867
1868 static const struct file_operations proc_coredump_filter_operations = {
1869 .read = proc_coredump_filter_read,
1870 .write = proc_coredump_filter_write,
1871 };
1872 #endif
1873
1874 /*
1875 * /proc/self:
1876 */
1877 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1878 int buflen)
1879 {
1880 char tmp[PROC_NUMBUF];
1881 sprintf(tmp, "%d", current->tgid);
1882 return vfs_readlink(dentry,buffer,buflen,tmp);
1883 }
1884
1885 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1886 {
1887 char tmp[PROC_NUMBUF];
1888 sprintf(tmp, "%d", current->tgid);
1889 return ERR_PTR(vfs_follow_link(nd,tmp));
1890 }
1891
1892 static const struct inode_operations proc_self_inode_operations = {
1893 .readlink = proc_self_readlink,
1894 .follow_link = proc_self_follow_link,
1895 };
1896
1897 /*
1898 * proc base
1899 *
1900 * These are the directory entries in the root directory of /proc
1901 * that properly belong to the /proc filesystem, as they describe
1902 * describe something that is process related.
1903 */
1904 static const struct pid_entry proc_base_stuff[] = {
1905 NOD("self", S_IFLNK|S_IRWXUGO,
1906 &proc_self_inode_operations, NULL, {}),
1907 };
1908
1909 /*
1910 * Exceptional case: normally we are not allowed to unhash a busy
1911 * directory. In this case, however, we can do it - no aliasing problems
1912 * due to the way we treat inodes.
1913 */
1914 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
1915 {
1916 struct inode *inode = dentry->d_inode;
1917 struct task_struct *task = get_proc_task(inode);
1918 if (task) {
1919 put_task_struct(task);
1920 return 1;
1921 }
1922 d_drop(dentry);
1923 return 0;
1924 }
1925
1926 static struct dentry_operations proc_base_dentry_operations =
1927 {
1928 .d_revalidate = proc_base_revalidate,
1929 .d_delete = pid_delete_dentry,
1930 };
1931
1932 static struct dentry *proc_base_instantiate(struct inode *dir,
1933 struct dentry *dentry, struct task_struct *task, const void *ptr)
1934 {
1935 const struct pid_entry *p = ptr;
1936 struct inode *inode;
1937 struct proc_inode *ei;
1938 struct dentry *error = ERR_PTR(-EINVAL);
1939
1940 /* Allocate the inode */
1941 error = ERR_PTR(-ENOMEM);
1942 inode = new_inode(dir->i_sb);
1943 if (!inode)
1944 goto out;
1945
1946 /* Initialize the inode */
1947 ei = PROC_I(inode);
1948 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1949
1950 /*
1951 * grab the reference to the task.
1952 */
1953 ei->pid = get_task_pid(task, PIDTYPE_PID);
1954 if (!ei->pid)
1955 goto out_iput;
1956
1957 inode->i_uid = 0;
1958 inode->i_gid = 0;
1959 inode->i_mode = p->mode;
1960 if (S_ISDIR(inode->i_mode))
1961 inode->i_nlink = 2;
1962 if (S_ISLNK(inode->i_mode))
1963 inode->i_size = 64;
1964 if (p->iop)
1965 inode->i_op = p->iop;
1966 if (p->fop)
1967 inode->i_fop = p->fop;
1968 ei->op = p->op;
1969 dentry->d_op = &proc_base_dentry_operations;
1970 d_add(dentry, inode);
1971 error = NULL;
1972 out:
1973 return error;
1974 out_iput:
1975 iput(inode);
1976 goto out;
1977 }
1978
1979 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
1980 {
1981 struct dentry *error;
1982 struct task_struct *task = get_proc_task(dir);
1983 const struct pid_entry *p, *last;
1984
1985 error = ERR_PTR(-ENOENT);
1986
1987 if (!task)
1988 goto out_no_task;
1989
1990 /* Lookup the directory entry */
1991 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
1992 for (p = proc_base_stuff; p <= last; p++) {
1993 if (p->len != dentry->d_name.len)
1994 continue;
1995 if (!memcmp(dentry->d_name.name, p->name, p->len))
1996 break;
1997 }
1998 if (p > last)
1999 goto out;
2000
2001 error = proc_base_instantiate(dir, dentry, task, p);
2002
2003 out:
2004 put_task_struct(task);
2005 out_no_task:
2006 return error;
2007 }
2008
2009 static int proc_base_fill_cache(struct file *filp, void *dirent,
2010 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2011 {
2012 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2013 proc_base_instantiate, task, p);
2014 }
2015
2016 #ifdef CONFIG_TASK_IO_ACCOUNTING
2017 static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
2018 {
2019 return sprintf(buffer,
2020 #ifdef CONFIG_TASK_XACCT
2021 "rchar: %llu\n"
2022 "wchar: %llu\n"
2023 "syscr: %llu\n"
2024 "syscw: %llu\n"
2025 #endif
2026 "read_bytes: %llu\n"
2027 "write_bytes: %llu\n"
2028 "cancelled_write_bytes: %llu\n",
2029 #ifdef CONFIG_TASK_XACCT
2030 (unsigned long long)task->rchar,
2031 (unsigned long long)task->wchar,
2032 (unsigned long long)task->syscr,
2033 (unsigned long long)task->syscw,
2034 #endif
2035 (unsigned long long)task->ioac.read_bytes,
2036 (unsigned long long)task->ioac.write_bytes,
2037 (unsigned long long)task->ioac.cancelled_write_bytes);
2038 }
2039 #endif
2040
2041 /*
2042 * Thread groups
2043 */
2044 static const struct file_operations proc_task_operations;
2045 static const struct inode_operations proc_task_inode_operations;
2046
2047 static const struct pid_entry tgid_base_stuff[] = {
2048 DIR("task", S_IRUGO|S_IXUGO, task),
2049 DIR("fd", S_IRUSR|S_IXUSR, fd),
2050 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2051 INF("environ", S_IRUSR, pid_environ),
2052 INF("auxv", S_IRUSR, pid_auxv),
2053 INF("status", S_IRUGO, pid_status),
2054 #ifdef CONFIG_SCHED_DEBUG
2055 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2056 #endif
2057 INF("cmdline", S_IRUGO, pid_cmdline),
2058 INF("stat", S_IRUGO, tgid_stat),
2059 INF("statm", S_IRUGO, pid_statm),
2060 REG("maps", S_IRUGO, maps),
2061 #ifdef CONFIG_NUMA
2062 REG("numa_maps", S_IRUGO, numa_maps),
2063 #endif
2064 REG("mem", S_IRUSR|S_IWUSR, mem),
2065 LNK("cwd", cwd),
2066 LNK("root", root),
2067 LNK("exe", exe),
2068 REG("mounts", S_IRUGO, mounts),
2069 REG("mountstats", S_IRUSR, mountstats),
2070 #ifdef CONFIG_MMU
2071 REG("clear_refs", S_IWUSR, clear_refs),
2072 REG("smaps", S_IRUGO, smaps),
2073 #endif
2074 #ifdef CONFIG_SECURITY
2075 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2076 #endif
2077 #ifdef CONFIG_KALLSYMS
2078 INF("wchan", S_IRUGO, pid_wchan),
2079 #endif
2080 #ifdef CONFIG_SCHEDSTATS
2081 INF("schedstat", S_IRUGO, pid_schedstat),
2082 #endif
2083 #ifdef CONFIG_CPUSETS
2084 REG("cpuset", S_IRUGO, cpuset),
2085 #endif
2086 INF("oom_score", S_IRUGO, oom_score),
2087 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2088 #ifdef CONFIG_AUDITSYSCALL
2089 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2090 #endif
2091 #ifdef CONFIG_FAULT_INJECTION
2092 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2093 #endif
2094 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2095 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2096 #endif
2097 #ifdef CONFIG_TASK_IO_ACCOUNTING
2098 INF("io", S_IRUGO, pid_io_accounting),
2099 #endif
2100 };
2101
2102 static int proc_tgid_base_readdir(struct file * filp,
2103 void * dirent, filldir_t filldir)
2104 {
2105 return proc_pident_readdir(filp,dirent,filldir,
2106 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2107 }
2108
2109 static const struct file_operations proc_tgid_base_operations = {
2110 .read = generic_read_dir,
2111 .readdir = proc_tgid_base_readdir,
2112 };
2113
2114 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2115 return proc_pident_lookup(dir, dentry,
2116 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2117 }
2118
2119 static const struct inode_operations proc_tgid_base_inode_operations = {
2120 .lookup = proc_tgid_base_lookup,
2121 .getattr = pid_getattr,
2122 .setattr = proc_setattr,
2123 };
2124
2125 /**
2126 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2127 *
2128 * @task: task that should be flushed.
2129 *
2130 * Looks in the dcache for
2131 * /proc/@pid
2132 * /proc/@tgid/task/@pid
2133 * if either directory is present flushes it and all of it'ts children
2134 * from the dcache.
2135 *
2136 * It is safe and reasonable to cache /proc entries for a task until
2137 * that task exits. After that they just clog up the dcache with
2138 * useless entries, possibly causing useful dcache entries to be
2139 * flushed instead. This routine is proved to flush those useless
2140 * dcache entries at process exit time.
2141 *
2142 * NOTE: This routine is just an optimization so it does not guarantee
2143 * that no dcache entries will exist at process exit time it
2144 * just makes it very unlikely that any will persist.
2145 */
2146 void proc_flush_task(struct task_struct *task)
2147 {
2148 struct dentry *dentry, *leader, *dir;
2149 char buf[PROC_NUMBUF];
2150 struct qstr name;
2151
2152 name.name = buf;
2153 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
2154 dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name);
2155 if (dentry) {
2156 shrink_dcache_parent(dentry);
2157 d_drop(dentry);
2158 dput(dentry);
2159 }
2160
2161 if (thread_group_leader(task))
2162 goto out;
2163
2164 name.name = buf;
2165 name.len = snprintf(buf, sizeof(buf), "%d", task->tgid);
2166 leader = d_hash_and_lookup(proc_mnt->mnt_root, &name);
2167 if (!leader)
2168 goto out;
2169
2170 name.name = "task";
2171 name.len = strlen(name.name);
2172 dir = d_hash_and_lookup(leader, &name);
2173 if (!dir)
2174 goto out_put_leader;
2175
2176 name.name = buf;
2177 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
2178 dentry = d_hash_and_lookup(dir, &name);
2179 if (dentry) {
2180 shrink_dcache_parent(dentry);
2181 d_drop(dentry);
2182 dput(dentry);
2183 }
2184
2185 dput(dir);
2186 out_put_leader:
2187 dput(leader);
2188 out:
2189 return;
2190 }
2191
2192 static struct dentry *proc_pid_instantiate(struct inode *dir,
2193 struct dentry * dentry,
2194 struct task_struct *task, const void *ptr)
2195 {
2196 struct dentry *error = ERR_PTR(-ENOENT);
2197 struct inode *inode;
2198
2199 inode = proc_pid_make_inode(dir->i_sb, task);
2200 if (!inode)
2201 goto out;
2202
2203 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2204 inode->i_op = &proc_tgid_base_inode_operations;
2205 inode->i_fop = &proc_tgid_base_operations;
2206 inode->i_flags|=S_IMMUTABLE;
2207 inode->i_nlink = 5;
2208 #ifdef CONFIG_SECURITY
2209 inode->i_nlink += 1;
2210 #endif
2211
2212 dentry->d_op = &pid_dentry_operations;
2213
2214 d_add(dentry, inode);
2215 /* Close the race of the process dying before we return the dentry */
2216 if (pid_revalidate(dentry, NULL))
2217 error = NULL;
2218 out:
2219 return error;
2220 }
2221
2222 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2223 {
2224 struct dentry *result = ERR_PTR(-ENOENT);
2225 struct task_struct *task;
2226 unsigned tgid;
2227
2228 result = proc_base_lookup(dir, dentry);
2229 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2230 goto out;
2231
2232 tgid = name_to_int(dentry);
2233 if (tgid == ~0U)
2234 goto out;
2235
2236 rcu_read_lock();
2237 task = find_task_by_pid(tgid);
2238 if (task)
2239 get_task_struct(task);
2240 rcu_read_unlock();
2241 if (!task)
2242 goto out;
2243
2244 result = proc_pid_instantiate(dir, dentry, task, NULL);
2245 put_task_struct(task);
2246 out:
2247 return result;
2248 }
2249
2250 /*
2251 * Find the first task with tgid >= tgid
2252 *
2253 */
2254 static struct task_struct *next_tgid(unsigned int tgid)
2255 {
2256 struct task_struct *task;
2257 struct pid *pid;
2258
2259 rcu_read_lock();
2260 retry:
2261 task = NULL;
2262 pid = find_ge_pid(tgid);
2263 if (pid) {
2264 tgid = pid->nr + 1;
2265 task = pid_task(pid, PIDTYPE_PID);
2266 /* What we to know is if the pid we have find is the
2267 * pid of a thread_group_leader. Testing for task
2268 * being a thread_group_leader is the obvious thing
2269 * todo but there is a window when it fails, due to
2270 * the pid transfer logic in de_thread.
2271 *
2272 * So we perform the straight forward test of seeing
2273 * if the pid we have found is the pid of a thread
2274 * group leader, and don't worry if the task we have
2275 * found doesn't happen to be a thread group leader.
2276 * As we don't care in the case of readdir.
2277 */
2278 if (!task || !has_group_leader_pid(task))
2279 goto retry;
2280 get_task_struct(task);
2281 }
2282 rcu_read_unlock();
2283 return task;
2284 }
2285
2286 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2287
2288 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2289 struct task_struct *task, int tgid)
2290 {
2291 char name[PROC_NUMBUF];
2292 int len = snprintf(name, sizeof(name), "%d", tgid);
2293 return proc_fill_cache(filp, dirent, filldir, name, len,
2294 proc_pid_instantiate, task, NULL);
2295 }
2296
2297 /* for the /proc/ directory itself, after non-process stuff has been done */
2298 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2299 {
2300 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2301 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2302 struct task_struct *task;
2303 int tgid;
2304
2305 if (!reaper)
2306 goto out_no_task;
2307
2308 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2309 const struct pid_entry *p = &proc_base_stuff[nr];
2310 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2311 goto out;
2312 }
2313
2314 tgid = filp->f_pos - TGID_OFFSET;
2315 for (task = next_tgid(tgid);
2316 task;
2317 put_task_struct(task), task = next_tgid(tgid + 1)) {
2318 tgid = task->pid;
2319 filp->f_pos = tgid + TGID_OFFSET;
2320 if (proc_pid_fill_cache(filp, dirent, filldir, task, tgid) < 0) {
2321 put_task_struct(task);
2322 goto out;
2323 }
2324 }
2325 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2326 out:
2327 put_task_struct(reaper);
2328 out_no_task:
2329 return 0;
2330 }
2331
2332 /*
2333 * Tasks
2334 */
2335 static const struct pid_entry tid_base_stuff[] = {
2336 DIR("fd", S_IRUSR|S_IXUSR, fd),
2337 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2338 INF("environ", S_IRUSR, pid_environ),
2339 INF("auxv", S_IRUSR, pid_auxv),
2340 INF("status", S_IRUGO, pid_status),
2341 #ifdef CONFIG_SCHED_DEBUG
2342 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2343 #endif
2344 INF("cmdline", S_IRUGO, pid_cmdline),
2345 INF("stat", S_IRUGO, tid_stat),
2346 INF("statm", S_IRUGO, pid_statm),
2347 REG("maps", S_IRUGO, maps),
2348 #ifdef CONFIG_NUMA
2349 REG("numa_maps", S_IRUGO, numa_maps),
2350 #endif
2351 REG("mem", S_IRUSR|S_IWUSR, mem),
2352 LNK("cwd", cwd),
2353 LNK("root", root),
2354 LNK("exe", exe),
2355 REG("mounts", S_IRUGO, mounts),
2356 #ifdef CONFIG_MMU
2357 REG("clear_refs", S_IWUSR, clear_refs),
2358 REG("smaps", S_IRUGO, smaps),
2359 #endif
2360 #ifdef CONFIG_SECURITY
2361 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2362 #endif
2363 #ifdef CONFIG_KALLSYMS
2364 INF("wchan", S_IRUGO, pid_wchan),
2365 #endif
2366 #ifdef CONFIG_SCHEDSTATS
2367 INF("schedstat", S_IRUGO, pid_schedstat),
2368 #endif
2369 #ifdef CONFIG_CPUSETS
2370 REG("cpuset", S_IRUGO, cpuset),
2371 #endif
2372 INF("oom_score", S_IRUGO, oom_score),
2373 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2374 #ifdef CONFIG_AUDITSYSCALL
2375 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2376 #endif
2377 #ifdef CONFIG_FAULT_INJECTION
2378 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2379 #endif
2380 };
2381
2382 static int proc_tid_base_readdir(struct file * filp,
2383 void * dirent, filldir_t filldir)
2384 {
2385 return proc_pident_readdir(filp,dirent,filldir,
2386 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2387 }
2388
2389 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2390 return proc_pident_lookup(dir, dentry,
2391 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2392 }
2393
2394 static const struct file_operations proc_tid_base_operations = {
2395 .read = generic_read_dir,
2396 .readdir = proc_tid_base_readdir,
2397 };
2398
2399 static const struct inode_operations proc_tid_base_inode_operations = {
2400 .lookup = proc_tid_base_lookup,
2401 .getattr = pid_getattr,
2402 .setattr = proc_setattr,
2403 };
2404
2405 static struct dentry *proc_task_instantiate(struct inode *dir,
2406 struct dentry *dentry, struct task_struct *task, const void *ptr)
2407 {
2408 struct dentry *error = ERR_PTR(-ENOENT);
2409 struct inode *inode;
2410 inode = proc_pid_make_inode(dir->i_sb, task);
2411
2412 if (!inode)
2413 goto out;
2414 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2415 inode->i_op = &proc_tid_base_inode_operations;
2416 inode->i_fop = &proc_tid_base_operations;
2417 inode->i_flags|=S_IMMUTABLE;
2418 inode->i_nlink = 4;
2419 #ifdef CONFIG_SECURITY
2420 inode->i_nlink += 1;
2421 #endif
2422
2423 dentry->d_op = &pid_dentry_operations;
2424
2425 d_add(dentry, inode);
2426 /* Close the race of the process dying before we return the dentry */
2427 if (pid_revalidate(dentry, NULL))
2428 error = NULL;
2429 out:
2430 return error;
2431 }
2432
2433 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2434 {
2435 struct dentry *result = ERR_PTR(-ENOENT);
2436 struct task_struct *task;
2437 struct task_struct *leader = get_proc_task(dir);
2438 unsigned tid;
2439
2440 if (!leader)
2441 goto out_no_task;
2442
2443 tid = name_to_int(dentry);
2444 if (tid == ~0U)
2445 goto out;
2446
2447 rcu_read_lock();
2448 task = find_task_by_pid(tid);
2449 if (task)
2450 get_task_struct(task);
2451 rcu_read_unlock();
2452 if (!task)
2453 goto out;
2454 if (leader->tgid != task->tgid)
2455 goto out_drop_task;
2456
2457 result = proc_task_instantiate(dir, dentry, task, NULL);
2458 out_drop_task:
2459 put_task_struct(task);
2460 out:
2461 put_task_struct(leader);
2462 out_no_task:
2463 return result;
2464 }
2465
2466 /*
2467 * Find the first tid of a thread group to return to user space.
2468 *
2469 * Usually this is just the thread group leader, but if the users
2470 * buffer was too small or there was a seek into the middle of the
2471 * directory we have more work todo.
2472 *
2473 * In the case of a short read we start with find_task_by_pid.
2474 *
2475 * In the case of a seek we start with the leader and walk nr
2476 * threads past it.
2477 */
2478 static struct task_struct *first_tid(struct task_struct *leader,
2479 int tid, int nr)
2480 {
2481 struct task_struct *pos;
2482
2483 rcu_read_lock();
2484 /* Attempt to start with the pid of a thread */
2485 if (tid && (nr > 0)) {
2486 pos = find_task_by_pid(tid);
2487 if (pos && (pos->group_leader == leader))
2488 goto found;
2489 }
2490
2491 /* If nr exceeds the number of threads there is nothing todo */
2492 pos = NULL;
2493 if (nr && nr >= get_nr_threads(leader))
2494 goto out;
2495
2496 /* If we haven't found our starting place yet start
2497 * with the leader and walk nr threads forward.
2498 */
2499 for (pos = leader; nr > 0; --nr) {
2500 pos = next_thread(pos);
2501 if (pos == leader) {
2502 pos = NULL;
2503 goto out;
2504 }
2505 }
2506 found:
2507 get_task_struct(pos);
2508 out:
2509 rcu_read_unlock();
2510 return pos;
2511 }
2512
2513 /*
2514 * Find the next thread in the thread list.
2515 * Return NULL if there is an error or no next thread.
2516 *
2517 * The reference to the input task_struct is released.
2518 */
2519 static struct task_struct *next_tid(struct task_struct *start)
2520 {
2521 struct task_struct *pos = NULL;
2522 rcu_read_lock();
2523 if (pid_alive(start)) {
2524 pos = next_thread(start);
2525 if (thread_group_leader(pos))
2526 pos = NULL;
2527 else
2528 get_task_struct(pos);
2529 }
2530 rcu_read_unlock();
2531 put_task_struct(start);
2532 return pos;
2533 }
2534
2535 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2536 struct task_struct *task, int tid)
2537 {
2538 char name[PROC_NUMBUF];
2539 int len = snprintf(name, sizeof(name), "%d", tid);
2540 return proc_fill_cache(filp, dirent, filldir, name, len,
2541 proc_task_instantiate, task, NULL);
2542 }
2543
2544 /* for the /proc/TGID/task/ directories */
2545 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2546 {
2547 struct dentry *dentry = filp->f_path.dentry;
2548 struct inode *inode = dentry->d_inode;
2549 struct task_struct *leader = NULL;
2550 struct task_struct *task;
2551 int retval = -ENOENT;
2552 ino_t ino;
2553 int tid;
2554 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2555
2556 task = get_proc_task(inode);
2557 if (!task)
2558 goto out_no_task;
2559 rcu_read_lock();
2560 if (pid_alive(task)) {
2561 leader = task->group_leader;
2562 get_task_struct(leader);
2563 }
2564 rcu_read_unlock();
2565 put_task_struct(task);
2566 if (!leader)
2567 goto out_no_task;
2568 retval = 0;
2569
2570 switch (pos) {
2571 case 0:
2572 ino = inode->i_ino;
2573 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2574 goto out;
2575 pos++;
2576 /* fall through */
2577 case 1:
2578 ino = parent_ino(dentry);
2579 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2580 goto out;
2581 pos++;
2582 /* fall through */
2583 }
2584
2585 /* f_version caches the tgid value that the last readdir call couldn't
2586 * return. lseek aka telldir automagically resets f_version to 0.
2587 */
2588 tid = filp->f_version;
2589 filp->f_version = 0;
2590 for (task = first_tid(leader, tid, pos - 2);
2591 task;
2592 task = next_tid(task), pos++) {
2593 tid = task->pid;
2594 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2595 /* returning this tgid failed, save it as the first
2596 * pid for the next readir call */
2597 filp->f_version = tid;
2598 put_task_struct(task);
2599 break;
2600 }
2601 }
2602 out:
2603 filp->f_pos = pos;
2604 put_task_struct(leader);
2605 out_no_task:
2606 return retval;
2607 }
2608
2609 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2610 {
2611 struct inode *inode = dentry->d_inode;
2612 struct task_struct *p = get_proc_task(inode);
2613 generic_fillattr(inode, stat);
2614
2615 if (p) {
2616 rcu_read_lock();
2617 stat->nlink += get_nr_threads(p);
2618 rcu_read_unlock();
2619 put_task_struct(p);
2620 }
2621
2622 return 0;
2623 }
2624
2625 static const struct inode_operations proc_task_inode_operations = {
2626 .lookup = proc_task_lookup,
2627 .getattr = proc_task_getattr,
2628 .setattr = proc_setattr,
2629 };
2630
2631 static const struct file_operations proc_task_operations = {
2632 .read = generic_read_dir,
2633 .readdir = proc_task_readdir,
2634 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree