This source file includes following definitions.
- pde_free
- proc_match
- pde_subdir_first
- pde_subdir_next
- pde_subdir_find
- pde_subdir_insert
- proc_notify_change
- proc_getattr
- __xlate_proc_name
- xlate_proc_name
- proc_alloc_inum
- proc_free_inum
- proc_misc_d_revalidate
- proc_misc_d_delete
- proc_lookup_de
- proc_lookup
- proc_readdir_de
- proc_readdir
- proc_register
- __proc_create
- proc_symlink
- proc_mkdir_data
- proc_mkdir_mode
- proc_mkdir
- proc_create_mount_point
- proc_create_reg
- proc_create_data
- proc_create
- proc_seq_open
- proc_seq_release
- proc_create_seq_private
- proc_single_open
- proc_create_single_data
- proc_set_size
- proc_set_user
- pde_put
- remove_proc_entry
- remove_proc_subtree
- proc_get_parent_data
- proc_remove
- PDE_DATA
- proc_simple_write
1
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11
12 #include <linux/cache.h>
13 #include <linux/errno.h>
14 #include <linux/time.h>
15 #include <linux/proc_fs.h>
16 #include <linux/stat.h>
17 #include <linux/mm.h>
18 #include <linux/module.h>
19 #include <linux/namei.h>
20 #include <linux/slab.h>
21 #include <linux/printk.h>
22 #include <linux/mount.h>
23 #include <linux/init.h>
24 #include <linux/idr.h>
25 #include <linux/bitops.h>
26 #include <linux/spinlock.h>
27 #include <linux/completion.h>
28 #include <linux/uaccess.h>
29 #include <linux/seq_file.h>
30
31 #include "internal.h"
32
33 static DEFINE_RWLOCK(proc_subdir_lock);
34
35 struct kmem_cache *proc_dir_entry_cache __ro_after_init;
36
37 void pde_free(struct proc_dir_entry *pde)
38 {
39 if (S_ISLNK(pde->mode))
40 kfree(pde->data);
41 if (pde->name != pde->inline_name)
42 kfree(pde->name);
43 kmem_cache_free(proc_dir_entry_cache, pde);
44 }
45
46 static int proc_match(const char *name, struct proc_dir_entry *de, unsigned int len)
47 {
48 if (len < de->namelen)
49 return -1;
50 if (len > de->namelen)
51 return 1;
52
53 return memcmp(name, de->name, len);
54 }
55
56 static struct proc_dir_entry *pde_subdir_first(struct proc_dir_entry *dir)
57 {
58 return rb_entry_safe(rb_first(&dir->subdir), struct proc_dir_entry,
59 subdir_node);
60 }
61
62 static struct proc_dir_entry *pde_subdir_next(struct proc_dir_entry *dir)
63 {
64 return rb_entry_safe(rb_next(&dir->subdir_node), struct proc_dir_entry,
65 subdir_node);
66 }
67
68 static struct proc_dir_entry *pde_subdir_find(struct proc_dir_entry *dir,
69 const char *name,
70 unsigned int len)
71 {
72 struct rb_node *node = dir->subdir.rb_node;
73
74 while (node) {
75 struct proc_dir_entry *de = rb_entry(node,
76 struct proc_dir_entry,
77 subdir_node);
78 int result = proc_match(name, de, len);
79
80 if (result < 0)
81 node = node->rb_left;
82 else if (result > 0)
83 node = node->rb_right;
84 else
85 return de;
86 }
87 return NULL;
88 }
89
90 static bool pde_subdir_insert(struct proc_dir_entry *dir,
91 struct proc_dir_entry *de)
92 {
93 struct rb_root *root = &dir->subdir;
94 struct rb_node **new = &root->rb_node, *parent = NULL;
95
96
97 while (*new) {
98 struct proc_dir_entry *this = rb_entry(*new,
99 struct proc_dir_entry,
100 subdir_node);
101 int result = proc_match(de->name, this, de->namelen);
102
103 parent = *new;
104 if (result < 0)
105 new = &(*new)->rb_left;
106 else if (result > 0)
107 new = &(*new)->rb_right;
108 else
109 return false;
110 }
111
112
113 rb_link_node(&de->subdir_node, parent, new);
114 rb_insert_color(&de->subdir_node, root);
115 return true;
116 }
117
118 static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
119 {
120 struct inode *inode = d_inode(dentry);
121 struct proc_dir_entry *de = PDE(inode);
122 int error;
123
124 error = setattr_prepare(dentry, iattr);
125 if (error)
126 return error;
127
128 setattr_copy(inode, iattr);
129 mark_inode_dirty(inode);
130
131 proc_set_user(de, inode->i_uid, inode->i_gid);
132 de->mode = inode->i_mode;
133 return 0;
134 }
135
136 static int proc_getattr(const struct path *path, struct kstat *stat,
137 u32 request_mask, unsigned int query_flags)
138 {
139 struct inode *inode = d_inode(path->dentry);
140 struct proc_dir_entry *de = PDE(inode);
141 if (de && de->nlink)
142 set_nlink(inode, de->nlink);
143
144 generic_fillattr(inode, stat);
145 return 0;
146 }
147
148 static const struct inode_operations proc_file_inode_operations = {
149 .setattr = proc_notify_change,
150 };
151
152
153
154
155
156
157 static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
158 const char **residual)
159 {
160 const char *cp = name, *next;
161 struct proc_dir_entry *de;
162 unsigned int len;
163
164 de = *ret;
165 if (!de)
166 de = &proc_root;
167
168 while (1) {
169 next = strchr(cp, '/');
170 if (!next)
171 break;
172
173 len = next - cp;
174 de = pde_subdir_find(de, cp, len);
175 if (!de) {
176 WARN(1, "name '%s'\n", name);
177 return -ENOENT;
178 }
179 cp += len + 1;
180 }
181 *residual = cp;
182 *ret = de;
183 return 0;
184 }
185
186 static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
187 const char **residual)
188 {
189 int rv;
190
191 read_lock(&proc_subdir_lock);
192 rv = __xlate_proc_name(name, ret, residual);
193 read_unlock(&proc_subdir_lock);
194 return rv;
195 }
196
197 static DEFINE_IDA(proc_inum_ida);
198
199 #define PROC_DYNAMIC_FIRST 0xF0000000U
200
201
202
203
204
205 int proc_alloc_inum(unsigned int *inum)
206 {
207 int i;
208
209 i = ida_simple_get(&proc_inum_ida, 0, UINT_MAX - PROC_DYNAMIC_FIRST + 1,
210 GFP_KERNEL);
211 if (i < 0)
212 return i;
213
214 *inum = PROC_DYNAMIC_FIRST + (unsigned int)i;
215 return 0;
216 }
217
218 void proc_free_inum(unsigned int inum)
219 {
220 ida_simple_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
221 }
222
223 static int proc_misc_d_revalidate(struct dentry *dentry, unsigned int flags)
224 {
225 if (flags & LOOKUP_RCU)
226 return -ECHILD;
227
228 if (atomic_read(&PDE(d_inode(dentry))->in_use) < 0)
229 return 0;
230 return 1;
231 }
232
233 static int proc_misc_d_delete(const struct dentry *dentry)
234 {
235 return atomic_read(&PDE(d_inode(dentry))->in_use) < 0;
236 }
237
238 static const struct dentry_operations proc_misc_dentry_ops = {
239 .d_revalidate = proc_misc_d_revalidate,
240 .d_delete = proc_misc_d_delete,
241 };
242
243
244
245
246
247 struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry,
248 struct proc_dir_entry *de)
249 {
250 struct inode *inode;
251
252 read_lock(&proc_subdir_lock);
253 de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len);
254 if (de) {
255 pde_get(de);
256 read_unlock(&proc_subdir_lock);
257 inode = proc_get_inode(dir->i_sb, de);
258 if (!inode)
259 return ERR_PTR(-ENOMEM);
260 d_set_d_op(dentry, de->proc_dops);
261 return d_splice_alias(inode, dentry);
262 }
263 read_unlock(&proc_subdir_lock);
264 return ERR_PTR(-ENOENT);
265 }
266
267 struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
268 unsigned int flags)
269 {
270 return proc_lookup_de(dir, dentry, PDE(dir));
271 }
272
273
274
275
276
277
278
279
280
281
282 int proc_readdir_de(struct file *file, struct dir_context *ctx,
283 struct proc_dir_entry *de)
284 {
285 int i;
286
287 if (!dir_emit_dots(file, ctx))
288 return 0;
289
290 i = ctx->pos - 2;
291 read_lock(&proc_subdir_lock);
292 de = pde_subdir_first(de);
293 for (;;) {
294 if (!de) {
295 read_unlock(&proc_subdir_lock);
296 return 0;
297 }
298 if (!i)
299 break;
300 de = pde_subdir_next(de);
301 i--;
302 }
303
304 do {
305 struct proc_dir_entry *next;
306 pde_get(de);
307 read_unlock(&proc_subdir_lock);
308 if (!dir_emit(ctx, de->name, de->namelen,
309 de->low_ino, de->mode >> 12)) {
310 pde_put(de);
311 return 0;
312 }
313 ctx->pos++;
314 read_lock(&proc_subdir_lock);
315 next = pde_subdir_next(de);
316 pde_put(de);
317 de = next;
318 } while (de);
319 read_unlock(&proc_subdir_lock);
320 return 1;
321 }
322
323 int proc_readdir(struct file *file, struct dir_context *ctx)
324 {
325 struct inode *inode = file_inode(file);
326
327 return proc_readdir_de(file, ctx, PDE(inode));
328 }
329
330
331
332
333
334
335 static const struct file_operations proc_dir_operations = {
336 .llseek = generic_file_llseek,
337 .read = generic_read_dir,
338 .iterate_shared = proc_readdir,
339 };
340
341
342
343
344 static const struct inode_operations proc_dir_inode_operations = {
345 .lookup = proc_lookup,
346 .getattr = proc_getattr,
347 .setattr = proc_notify_change,
348 };
349
350
351 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
352 struct proc_dir_entry *dp)
353 {
354 if (proc_alloc_inum(&dp->low_ino))
355 goto out_free_entry;
356
357 write_lock(&proc_subdir_lock);
358 dp->parent = dir;
359 if (pde_subdir_insert(dir, dp) == false) {
360 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
361 dir->name, dp->name);
362 write_unlock(&proc_subdir_lock);
363 goto out_free_inum;
364 }
365 write_unlock(&proc_subdir_lock);
366
367 return dp;
368 out_free_inum:
369 proc_free_inum(dp->low_ino);
370 out_free_entry:
371 pde_free(dp);
372 return NULL;
373 }
374
375 static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
376 const char *name,
377 umode_t mode,
378 nlink_t nlink)
379 {
380 struct proc_dir_entry *ent = NULL;
381 const char *fn;
382 struct qstr qstr;
383
384 if (xlate_proc_name(name, parent, &fn) != 0)
385 goto out;
386 qstr.name = fn;
387 qstr.len = strlen(fn);
388 if (qstr.len == 0 || qstr.len >= 256) {
389 WARN(1, "name len %u\n", qstr.len);
390 return NULL;
391 }
392 if (qstr.len == 1 && fn[0] == '.') {
393 WARN(1, "name '.'\n");
394 return NULL;
395 }
396 if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
397 WARN(1, "name '..'\n");
398 return NULL;
399 }
400 if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
401 WARN(1, "create '/proc/%s' by hand\n", qstr.name);
402 return NULL;
403 }
404 if (is_empty_pde(*parent)) {
405 WARN(1, "attempt to add to permanently empty directory");
406 return NULL;
407 }
408
409 ent = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
410 if (!ent)
411 goto out;
412
413 if (qstr.len + 1 <= SIZEOF_PDE_INLINE_NAME) {
414 ent->name = ent->inline_name;
415 } else {
416 ent->name = kmalloc(qstr.len + 1, GFP_KERNEL);
417 if (!ent->name) {
418 pde_free(ent);
419 return NULL;
420 }
421 }
422
423 memcpy(ent->name, fn, qstr.len + 1);
424 ent->namelen = qstr.len;
425 ent->mode = mode;
426 ent->nlink = nlink;
427 ent->subdir = RB_ROOT;
428 refcount_set(&ent->refcnt, 1);
429 spin_lock_init(&ent->pde_unload_lock);
430 INIT_LIST_HEAD(&ent->pde_openers);
431 proc_set_user(ent, (*parent)->uid, (*parent)->gid);
432
433 ent->proc_dops = &proc_misc_dentry_ops;
434
435 out:
436 return ent;
437 }
438
439 struct proc_dir_entry *proc_symlink(const char *name,
440 struct proc_dir_entry *parent, const char *dest)
441 {
442 struct proc_dir_entry *ent;
443
444 ent = __proc_create(&parent, name,
445 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
446
447 if (ent) {
448 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
449 if (ent->data) {
450 strcpy((char*)ent->data,dest);
451 ent->proc_iops = &proc_link_inode_operations;
452 ent = proc_register(parent, ent);
453 } else {
454 pde_free(ent);
455 ent = NULL;
456 }
457 }
458 return ent;
459 }
460 EXPORT_SYMBOL(proc_symlink);
461
462 struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
463 struct proc_dir_entry *parent, void *data)
464 {
465 struct proc_dir_entry *ent;
466
467 if (mode == 0)
468 mode = S_IRUGO | S_IXUGO;
469
470 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
471 if (ent) {
472 ent->data = data;
473 ent->proc_fops = &proc_dir_operations;
474 ent->proc_iops = &proc_dir_inode_operations;
475 parent->nlink++;
476 ent = proc_register(parent, ent);
477 if (!ent)
478 parent->nlink--;
479 }
480 return ent;
481 }
482 EXPORT_SYMBOL_GPL(proc_mkdir_data);
483
484 struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
485 struct proc_dir_entry *parent)
486 {
487 return proc_mkdir_data(name, mode, parent, NULL);
488 }
489 EXPORT_SYMBOL(proc_mkdir_mode);
490
491 struct proc_dir_entry *proc_mkdir(const char *name,
492 struct proc_dir_entry *parent)
493 {
494 return proc_mkdir_data(name, 0, parent, NULL);
495 }
496 EXPORT_SYMBOL(proc_mkdir);
497
498 struct proc_dir_entry *proc_create_mount_point(const char *name)
499 {
500 umode_t mode = S_IFDIR | S_IRUGO | S_IXUGO;
501 struct proc_dir_entry *ent, *parent = NULL;
502
503 ent = __proc_create(&parent, name, mode, 2);
504 if (ent) {
505 ent->data = NULL;
506 ent->proc_fops = NULL;
507 ent->proc_iops = NULL;
508 parent->nlink++;
509 ent = proc_register(parent, ent);
510 if (!ent)
511 parent->nlink--;
512 }
513 return ent;
514 }
515 EXPORT_SYMBOL(proc_create_mount_point);
516
517 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
518 struct proc_dir_entry **parent, void *data)
519 {
520 struct proc_dir_entry *p;
521
522 if ((mode & S_IFMT) == 0)
523 mode |= S_IFREG;
524 if ((mode & S_IALLUGO) == 0)
525 mode |= S_IRUGO;
526 if (WARN_ON_ONCE(!S_ISREG(mode)))
527 return NULL;
528
529 p = __proc_create(parent, name, mode, 1);
530 if (p) {
531 p->proc_iops = &proc_file_inode_operations;
532 p->data = data;
533 }
534 return p;
535 }
536
537 struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
538 struct proc_dir_entry *parent,
539 const struct file_operations *proc_fops, void *data)
540 {
541 struct proc_dir_entry *p;
542
543 BUG_ON(proc_fops == NULL);
544
545 p = proc_create_reg(name, mode, &parent, data);
546 if (!p)
547 return NULL;
548 p->proc_fops = proc_fops;
549 return proc_register(parent, p);
550 }
551 EXPORT_SYMBOL(proc_create_data);
552
553 struct proc_dir_entry *proc_create(const char *name, umode_t mode,
554 struct proc_dir_entry *parent,
555 const struct file_operations *proc_fops)
556 {
557 return proc_create_data(name, mode, parent, proc_fops, NULL);
558 }
559 EXPORT_SYMBOL(proc_create);
560
561 static int proc_seq_open(struct inode *inode, struct file *file)
562 {
563 struct proc_dir_entry *de = PDE(inode);
564
565 if (de->state_size)
566 return seq_open_private(file, de->seq_ops, de->state_size);
567 return seq_open(file, de->seq_ops);
568 }
569
570 static int proc_seq_release(struct inode *inode, struct file *file)
571 {
572 struct proc_dir_entry *de = PDE(inode);
573
574 if (de->state_size)
575 return seq_release_private(inode, file);
576 return seq_release(inode, file);
577 }
578
579 static const struct file_operations proc_seq_fops = {
580 .open = proc_seq_open,
581 .read = seq_read,
582 .llseek = seq_lseek,
583 .release = proc_seq_release,
584 };
585
586 struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
587 struct proc_dir_entry *parent, const struct seq_operations *ops,
588 unsigned int state_size, void *data)
589 {
590 struct proc_dir_entry *p;
591
592 p = proc_create_reg(name, mode, &parent, data);
593 if (!p)
594 return NULL;
595 p->proc_fops = &proc_seq_fops;
596 p->seq_ops = ops;
597 p->state_size = state_size;
598 return proc_register(parent, p);
599 }
600 EXPORT_SYMBOL(proc_create_seq_private);
601
602 static int proc_single_open(struct inode *inode, struct file *file)
603 {
604 struct proc_dir_entry *de = PDE(inode);
605
606 return single_open(file, de->single_show, de->data);
607 }
608
609 static const struct file_operations proc_single_fops = {
610 .open = proc_single_open,
611 .read = seq_read,
612 .llseek = seq_lseek,
613 .release = single_release,
614 };
615
616 struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
617 struct proc_dir_entry *parent,
618 int (*show)(struct seq_file *, void *), void *data)
619 {
620 struct proc_dir_entry *p;
621
622 p = proc_create_reg(name, mode, &parent, data);
623 if (!p)
624 return NULL;
625 p->proc_fops = &proc_single_fops;
626 p->single_show = show;
627 return proc_register(parent, p);
628 }
629 EXPORT_SYMBOL(proc_create_single_data);
630
631 void proc_set_size(struct proc_dir_entry *de, loff_t size)
632 {
633 de->size = size;
634 }
635 EXPORT_SYMBOL(proc_set_size);
636
637 void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
638 {
639 de->uid = uid;
640 de->gid = gid;
641 }
642 EXPORT_SYMBOL(proc_set_user);
643
644 void pde_put(struct proc_dir_entry *pde)
645 {
646 if (refcount_dec_and_test(&pde->refcnt)) {
647 proc_free_inum(pde->low_ino);
648 pde_free(pde);
649 }
650 }
651
652
653
654
655 void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
656 {
657 struct proc_dir_entry *de = NULL;
658 const char *fn = name;
659 unsigned int len;
660
661 write_lock(&proc_subdir_lock);
662 if (__xlate_proc_name(name, &parent, &fn) != 0) {
663 write_unlock(&proc_subdir_lock);
664 return;
665 }
666 len = strlen(fn);
667
668 de = pde_subdir_find(parent, fn, len);
669 if (de)
670 rb_erase(&de->subdir_node, &parent->subdir);
671 write_unlock(&proc_subdir_lock);
672 if (!de) {
673 WARN(1, "name '%s'\n", name);
674 return;
675 }
676
677 proc_entry_rundown(de);
678
679 if (S_ISDIR(de->mode))
680 parent->nlink--;
681 de->nlink = 0;
682 WARN(pde_subdir_first(de),
683 "%s: removing non-empty directory '%s/%s', leaking at least '%s'\n",
684 __func__, de->parent->name, de->name, pde_subdir_first(de)->name);
685 pde_put(de);
686 }
687 EXPORT_SYMBOL(remove_proc_entry);
688
689 int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
690 {
691 struct proc_dir_entry *root = NULL, *de, *next;
692 const char *fn = name;
693 unsigned int len;
694
695 write_lock(&proc_subdir_lock);
696 if (__xlate_proc_name(name, &parent, &fn) != 0) {
697 write_unlock(&proc_subdir_lock);
698 return -ENOENT;
699 }
700 len = strlen(fn);
701
702 root = pde_subdir_find(parent, fn, len);
703 if (!root) {
704 write_unlock(&proc_subdir_lock);
705 return -ENOENT;
706 }
707 rb_erase(&root->subdir_node, &parent->subdir);
708
709 de = root;
710 while (1) {
711 next = pde_subdir_first(de);
712 if (next) {
713 rb_erase(&next->subdir_node, &de->subdir);
714 de = next;
715 continue;
716 }
717 write_unlock(&proc_subdir_lock);
718
719 proc_entry_rundown(de);
720 next = de->parent;
721 if (S_ISDIR(de->mode))
722 next->nlink--;
723 de->nlink = 0;
724 if (de == root)
725 break;
726 pde_put(de);
727
728 write_lock(&proc_subdir_lock);
729 de = next;
730 }
731 pde_put(root);
732 return 0;
733 }
734 EXPORT_SYMBOL(remove_proc_subtree);
735
736 void *proc_get_parent_data(const struct inode *inode)
737 {
738 struct proc_dir_entry *de = PDE(inode);
739 return de->parent->data;
740 }
741 EXPORT_SYMBOL_GPL(proc_get_parent_data);
742
743 void proc_remove(struct proc_dir_entry *de)
744 {
745 if (de)
746 remove_proc_subtree(de->name, de->parent);
747 }
748 EXPORT_SYMBOL(proc_remove);
749
750 void *PDE_DATA(const struct inode *inode)
751 {
752 return __PDE_DATA(inode);
753 }
754 EXPORT_SYMBOL(PDE_DATA);
755
756
757
758
759
760
761 ssize_t proc_simple_write(struct file *f, const char __user *ubuf, size_t size,
762 loff_t *_pos)
763 {
764 struct proc_dir_entry *pde = PDE(file_inode(f));
765 char *buf;
766 int ret;
767
768 if (!pde->write)
769 return -EACCES;
770 if (size == 0 || size > PAGE_SIZE - 1)
771 return -EINVAL;
772 buf = memdup_user_nul(ubuf, size);
773 if (IS_ERR(buf))
774 return PTR_ERR(buf);
775 ret = pde->write(f, buf, size);
776 kfree(buf);
777 return ret == 0 ? size : ret;
778 }