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1/*
2 * proc/fs/generic.c --- generic routines for the proc-fs
3 *
4 * This file contains generic proc-fs routines for handling
5 * directories and files.
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds.
8 * Copyright (C) 1997 Theodore Ts'o
9 */
10
11#include <linux/cache.h>
12#include <linux/errno.h>
13#include <linux/time.h>
14#include <linux/proc_fs.h>
15#include <linux/stat.h>
16#include <linux/mm.h>
17#include <linux/module.h>
18#include <linux/namei.h>
19#include <linux/slab.h>
20#include <linux/printk.h>
21#include <linux/mount.h>
22#include <linux/init.h>
23#include <linux/idr.h>
24#include <linux/bitops.h>
25#include <linux/spinlock.h>
26#include <linux/completion.h>
27#include <linux/uaccess.h>
28
29#include "internal.h"
30
31static DEFINE_RWLOCK(proc_subdir_lock);
32
33struct kmem_cache *proc_dir_entry_cache __ro_after_init;
34
35void pde_free(struct proc_dir_entry *pde)
36{
37 if (S_ISLNK(pde->mode))
38 kfree(pde->data);
39 if (pde->name != pde->inline_name)
40 kfree(pde->name);
41 kmem_cache_free(proc_dir_entry_cache, pde);
42}
43
44static int proc_match(const char *name, struct proc_dir_entry *de, unsigned int len)
45{
46 if (len < de->namelen)
47 return -1;
48 if (len > de->namelen)
49 return 1;
50
51 return memcmp(name, de->name, len);
52}
53
54static struct proc_dir_entry *pde_subdir_first(struct proc_dir_entry *dir)
55{
56 return rb_entry_safe(rb_first(&dir->subdir), struct proc_dir_entry,
57 subdir_node);
58}
59
60static struct proc_dir_entry *pde_subdir_next(struct proc_dir_entry *dir)
61{
62 return rb_entry_safe(rb_next(&dir->subdir_node), struct proc_dir_entry,
63 subdir_node);
64}
65
66static struct proc_dir_entry *pde_subdir_find(struct proc_dir_entry *dir,
67 const char *name,
68 unsigned int len)
69{
70 struct rb_node *node = dir->subdir.rb_node;
71
72 while (node) {
73 struct proc_dir_entry *de = rb_entry(node,
74 struct proc_dir_entry,
75 subdir_node);
76 int result = proc_match(name, de, len);
77
78 if (result < 0)
79 node = node->rb_left;
80 else if (result > 0)
81 node = node->rb_right;
82 else
83 return de;
84 }
85 return NULL;
86}
87
88static bool pde_subdir_insert(struct proc_dir_entry *dir,
89 struct proc_dir_entry *de)
90{
91 struct rb_root *root = &dir->subdir;
92 struct rb_node **new = &root->rb_node, *parent = NULL;
93
94 /* Figure out where to put new node */
95 while (*new) {
96 struct proc_dir_entry *this = rb_entry(*new,
97 struct proc_dir_entry,
98 subdir_node);
99 int result = proc_match(de->name, this, de->namelen);
100
101 parent = *new;
102 if (result < 0)
103 new = &(*new)->rb_left;
104 else if (result > 0)
105 new = &(*new)->rb_right;
106 else
107 return false;
108 }
109
110 /* Add new node and rebalance tree. */
111 rb_link_node(&de->subdir_node, parent, new);
112 rb_insert_color(&de->subdir_node, root);
113 return true;
114}
115
116static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
117{
118 struct inode *inode = d_inode(dentry);
119 struct proc_dir_entry *de = PDE(inode);
120 int error;
121
122 error = setattr_prepare(dentry, iattr);
123 if (error)
124 return error;
125
126 setattr_copy(inode, iattr);
127 mark_inode_dirty(inode);
128
129 proc_set_user(de, inode->i_uid, inode->i_gid);
130 de->mode = inode->i_mode;
131 return 0;
132}
133
134static int proc_getattr(const struct path *path, struct kstat *stat,
135 u32 request_mask, unsigned int query_flags)
136{
137 struct inode *inode = d_inode(path->dentry);
138 struct proc_dir_entry *de = PDE(inode);
139 if (de && de->nlink)
140 set_nlink(inode, de->nlink);
141
142 generic_fillattr(inode, stat);
143 return 0;
144}
145
146static const struct inode_operations proc_file_inode_operations = {
147 .setattr = proc_notify_change,
148};
149
150/*
151 * This function parses a name such as "tty/driver/serial", and
152 * returns the struct proc_dir_entry for "/proc/tty/driver", and
153 * returns "serial" in residual.
154 */
155static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
156 const char **residual)
157{
158 const char *cp = name, *next;
159 struct proc_dir_entry *de;
160 unsigned int len;
161
162 de = *ret;
163 if (!de)
164 de = &proc_root;
165
166 while (1) {
167 next = strchr(cp, '/');
168 if (!next)
169 break;
170
171 len = next - cp;
172 de = pde_subdir_find(de, cp, len);
173 if (!de) {
174 WARN(1, "name '%s'\n", name);
175 return -ENOENT;
176 }
177 cp += len + 1;
178 }
179 *residual = cp;
180 *ret = de;
181 return 0;
182}
183
184static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
185 const char **residual)
186{
187 int rv;
188
189 read_lock(&proc_subdir_lock);
190 rv = __xlate_proc_name(name, ret, residual);
191 read_unlock(&proc_subdir_lock);
192 return rv;
193}
194
195static DEFINE_IDA(proc_inum_ida);
196
197#define PROC_DYNAMIC_FIRST 0xF0000000U
198
199/*
200 * Return an inode number between PROC_DYNAMIC_FIRST and
201 * 0xffffffff, or zero on failure.
202 */
203int proc_alloc_inum(unsigned int *inum)
204{
205 int i;
206
207 i = ida_simple_get(&proc_inum_ida, 0, UINT_MAX - PROC_DYNAMIC_FIRST + 1,
208 GFP_KERNEL);
209 if (i < 0)
210 return i;
211
212 *inum = PROC_DYNAMIC_FIRST + (unsigned int)i;
213 return 0;
214}
215
216void proc_free_inum(unsigned int inum)
217{
218 ida_simple_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
219}
220
221static int proc_misc_d_revalidate(struct dentry *dentry, unsigned int flags)
222{
223 if (flags & LOOKUP_RCU)
224 return -ECHILD;
225
226 if (atomic_read(&PDE(d_inode(dentry))->in_use) < 0)
227 return 0; /* revalidate */
228 return 1;
229}
230
231static int proc_misc_d_delete(const struct dentry *dentry)
232{
233 return atomic_read(&PDE(d_inode(dentry))->in_use) < 0;
234}
235
236static const struct dentry_operations proc_misc_dentry_ops = {
237 .d_revalidate = proc_misc_d_revalidate,
238 .d_delete = proc_misc_d_delete,
239};
240
241/*
242 * Don't create negative dentries here, return -ENOENT by hand
243 * instead.
244 */
245struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry,
246 struct proc_dir_entry *de)
247{
248 struct inode *inode;
249
250 read_lock(&proc_subdir_lock);
251 de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len);
252 if (de) {
253 pde_get(de);
254 read_unlock(&proc_subdir_lock);
255 inode = proc_get_inode(dir->i_sb, de);
256 if (!inode)
257 return ERR_PTR(-ENOMEM);
258 d_set_d_op(dentry, &proc_misc_dentry_ops);
259 d_add(dentry, inode);
260 return NULL;
261 }
262 read_unlock(&proc_subdir_lock);
263 return ERR_PTR(-ENOENT);
264}
265
266struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
267 unsigned int flags)
268{
269 return proc_lookup_de(dir, dentry, PDE(dir));
270}
271
272/*
273 * This returns non-zero if at EOF, so that the /proc
274 * root directory can use this and check if it should
275 * continue with the <pid> entries..
276 *
277 * Note that the VFS-layer doesn't care about the return
278 * value of the readdir() call, as long as it's non-negative
279 * for success..
280 */
281int proc_readdir_de(struct file *file, struct dir_context *ctx,
282 struct proc_dir_entry *de)
283{
284 int i;
285
286 if (!dir_emit_dots(file, ctx))
287 return 0;
288
289 read_lock(&proc_subdir_lock);
290 de = pde_subdir_first(de);
291 i = ctx->pos - 2;
292 for (;;) {
293 if (!de) {
294 read_unlock(&proc_subdir_lock);
295 return 0;
296 }
297 if (!i)
298 break;
299 de = pde_subdir_next(de);
300 i--;
301 }
302
303 do {
304 struct proc_dir_entry *next;
305 pde_get(de);
306 read_unlock(&proc_subdir_lock);
307 if (!dir_emit(ctx, de->name, de->namelen,
308 de->low_ino, de->mode >> 12)) {
309 pde_put(de);
310 return 0;
311 }
312 read_lock(&proc_subdir_lock);
313 ctx->pos++;
314 next = pde_subdir_next(de);
315 pde_put(de);
316 de = next;
317 } while (de);
318 read_unlock(&proc_subdir_lock);
319 return 1;
320}
321
322int proc_readdir(struct file *file, struct dir_context *ctx)
323{
324 struct inode *inode = file_inode(file);
325
326 return proc_readdir_de(file, ctx, PDE(inode));
327}
328
329/*
330 * These are the generic /proc directory operations. They
331 * use the in-memory "struct proc_dir_entry" tree to parse
332 * the /proc directory.
333 */
334static const struct file_operations proc_dir_operations = {
335 .llseek = generic_file_llseek,
336 .read = generic_read_dir,
337 .iterate_shared = proc_readdir,
338};
339
340/*
341 * proc directories can do almost nothing..
342 */
343static const struct inode_operations proc_dir_inode_operations = {
344 .lookup = proc_lookup,
345 .getattr = proc_getattr,
346 .setattr = proc_notify_change,
347};
348
349static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
350{
351 int ret;
352
353 ret = proc_alloc_inum(&dp->low_ino);
354 if (ret)
355 return ret;
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 proc_free_inum(dp->low_ino);
364 return -EEXIST;
365 }
366 write_unlock(&proc_subdir_lock);
367
368 return 0;
369}
370
371static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
372 const char *name,
373 umode_t mode,
374 nlink_t nlink)
375{
376 struct proc_dir_entry *ent = NULL;
377 const char *fn;
378 struct qstr qstr;
379
380 if (xlate_proc_name(name, parent, &fn) != 0)
381 goto out;
382 qstr.name = fn;
383 qstr.len = strlen(fn);
384 if (qstr.len == 0 || qstr.len >= 256) {
385 WARN(1, "name len %u\n", qstr.len);
386 return NULL;
387 }
388 if (qstr.len == 1 && fn[0] == '.') {
389 WARN(1, "name '.'\n");
390 return NULL;
391 }
392 if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
393 WARN(1, "name '..'\n");
394 return NULL;
395 }
396 if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
397 WARN(1, "create '/proc/%s' by hand\n", qstr.name);
398 return NULL;
399 }
400 if (is_empty_pde(*parent)) {
401 WARN(1, "attempt to add to permanently empty directory");
402 return NULL;
403 }
404
405 ent = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
406 if (!ent)
407 goto out;
408
409 if (qstr.len + 1 <= sizeof(ent->inline_name)) {
410 ent->name = ent->inline_name;
411 } else {
412 ent->name = kmalloc(qstr.len + 1, GFP_KERNEL);
413 if (!ent->name) {
414 pde_free(ent);
415 return NULL;
416 }
417 }
418
419 memcpy(ent->name, fn, qstr.len + 1);
420 ent->namelen = qstr.len;
421 ent->mode = mode;
422 ent->nlink = nlink;
423 ent->subdir = RB_ROOT;
424 refcount_set(&ent->refcnt, 1);
425 spin_lock_init(&ent->pde_unload_lock);
426 INIT_LIST_HEAD(&ent->pde_openers);
427 proc_set_user(ent, (*parent)->uid, (*parent)->gid);
428
429out:
430 return ent;
431}
432
433struct proc_dir_entry *proc_symlink(const char *name,
434 struct proc_dir_entry *parent, const char *dest)
435{
436 struct proc_dir_entry *ent;
437
438 ent = __proc_create(&parent, name,
439 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
440
441 if (ent) {
442 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
443 if (ent->data) {
444 strcpy((char*)ent->data,dest);
445 ent->proc_iops = &proc_link_inode_operations;
446 if (proc_register(parent, ent) < 0) {
447 pde_free(ent);
448 ent = NULL;
449 }
450 } else {
451 pde_free(ent);
452 ent = NULL;
453 }
454 }
455 return ent;
456}
457EXPORT_SYMBOL(proc_symlink);
458
459struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
460 struct proc_dir_entry *parent, void *data)
461{
462 struct proc_dir_entry *ent;
463
464 if (mode == 0)
465 mode = S_IRUGO | S_IXUGO;
466
467 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
468 if (ent) {
469 ent->data = data;
470 ent->proc_fops = &proc_dir_operations;
471 ent->proc_iops = &proc_dir_inode_operations;
472 parent->nlink++;
473 if (proc_register(parent, ent) < 0) {
474 pde_free(ent);
475 parent->nlink--;
476 ent = NULL;
477 }
478 }
479 return ent;
480}
481EXPORT_SYMBOL_GPL(proc_mkdir_data);
482
483struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
484 struct proc_dir_entry *parent)
485{
486 return proc_mkdir_data(name, mode, parent, NULL);
487}
488EXPORT_SYMBOL(proc_mkdir_mode);
489
490struct proc_dir_entry *proc_mkdir(const char *name,
491 struct proc_dir_entry *parent)
492{
493 return proc_mkdir_data(name, 0, parent, NULL);
494}
495EXPORT_SYMBOL(proc_mkdir);
496
497struct proc_dir_entry *proc_create_mount_point(const char *name)
498{
499 umode_t mode = S_IFDIR | S_IRUGO | S_IXUGO;
500 struct proc_dir_entry *ent, *parent = NULL;
501
502 ent = __proc_create(&parent, name, mode, 2);
503 if (ent) {
504 ent->data = NULL;
505 ent->proc_fops = NULL;
506 ent->proc_iops = NULL;
507 parent->nlink++;
508 if (proc_register(parent, ent) < 0) {
509 pde_free(ent);
510 parent->nlink--;
511 ent = NULL;
512 }
513 }
514 return ent;
515}
516EXPORT_SYMBOL(proc_create_mount_point);
517
518struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
519 struct proc_dir_entry *parent,
520 const struct file_operations *proc_fops,
521 void *data)
522{
523 struct proc_dir_entry *pde;
524 if ((mode & S_IFMT) == 0)
525 mode |= S_IFREG;
526
527 if (!S_ISREG(mode)) {
528 WARN_ON(1); /* use proc_mkdir() */
529 return NULL;
530 }
531
532 BUG_ON(proc_fops == NULL);
533
534 if ((mode & S_IALLUGO) == 0)
535 mode |= S_IRUGO;
536 pde = __proc_create(&parent, name, mode, 1);
537 if (!pde)
538 goto out;
539 pde->proc_fops = proc_fops;
540 pde->data = data;
541 pde->proc_iops = &proc_file_inode_operations;
542 if (proc_register(parent, pde) < 0)
543 goto out_free;
544 return pde;
545out_free:
546 pde_free(pde);
547out:
548 return NULL;
549}
550EXPORT_SYMBOL(proc_create_data);
551
552struct proc_dir_entry *proc_create(const char *name, umode_t mode,
553 struct proc_dir_entry *parent,
554 const struct file_operations *proc_fops)
555{
556 return proc_create_data(name, mode, parent, proc_fops, NULL);
557}
558EXPORT_SYMBOL(proc_create);
559
560void proc_set_size(struct proc_dir_entry *de, loff_t size)
561{
562 de->size = size;
563}
564EXPORT_SYMBOL(proc_set_size);
565
566void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
567{
568 de->uid = uid;
569 de->gid = gid;
570}
571EXPORT_SYMBOL(proc_set_user);
572
573void pde_put(struct proc_dir_entry *pde)
574{
575 if (refcount_dec_and_test(&pde->refcnt)) {
576 proc_free_inum(pde->low_ino);
577 pde_free(pde);
578 }
579}
580
581/*
582 * Remove a /proc entry and free it if it's not currently in use.
583 */
584void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
585{
586 struct proc_dir_entry *de = NULL;
587 const char *fn = name;
588 unsigned int len;
589
590 write_lock(&proc_subdir_lock);
591 if (__xlate_proc_name(name, &parent, &fn) != 0) {
592 write_unlock(&proc_subdir_lock);
593 return;
594 }
595 len = strlen(fn);
596
597 de = pde_subdir_find(parent, fn, len);
598 if (de)
599 rb_erase(&de->subdir_node, &parent->subdir);
600 write_unlock(&proc_subdir_lock);
601 if (!de) {
602 WARN(1, "name '%s'\n", name);
603 return;
604 }
605
606 proc_entry_rundown(de);
607
608 if (S_ISDIR(de->mode))
609 parent->nlink--;
610 de->nlink = 0;
611 WARN(pde_subdir_first(de),
612 "%s: removing non-empty directory '%s/%s', leaking at least '%s'\n",
613 __func__, de->parent->name, de->name, pde_subdir_first(de)->name);
614 pde_put(de);
615}
616EXPORT_SYMBOL(remove_proc_entry);
617
618int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
619{
620 struct proc_dir_entry *root = NULL, *de, *next;
621 const char *fn = name;
622 unsigned int len;
623
624 write_lock(&proc_subdir_lock);
625 if (__xlate_proc_name(name, &parent, &fn) != 0) {
626 write_unlock(&proc_subdir_lock);
627 return -ENOENT;
628 }
629 len = strlen(fn);
630
631 root = pde_subdir_find(parent, fn, len);
632 if (!root) {
633 write_unlock(&proc_subdir_lock);
634 return -ENOENT;
635 }
636 rb_erase(&root->subdir_node, &parent->subdir);
637
638 de = root;
639 while (1) {
640 next = pde_subdir_first(de);
641 if (next) {
642 rb_erase(&next->subdir_node, &de->subdir);
643 de = next;
644 continue;
645 }
646 write_unlock(&proc_subdir_lock);
647
648 proc_entry_rundown(de);
649 next = de->parent;
650 if (S_ISDIR(de->mode))
651 next->nlink--;
652 de->nlink = 0;
653 if (de == root)
654 break;
655 pde_put(de);
656
657 write_lock(&proc_subdir_lock);
658 de = next;
659 }
660 pde_put(root);
661 return 0;
662}
663EXPORT_SYMBOL(remove_proc_subtree);
664
665void *proc_get_parent_data(const struct inode *inode)
666{
667 struct proc_dir_entry *de = PDE(inode);
668 return de->parent->data;
669}
670EXPORT_SYMBOL_GPL(proc_get_parent_data);
671
672void proc_remove(struct proc_dir_entry *de)
673{
674 if (de)
675 remove_proc_subtree(de->name, de->parent);
676}
677EXPORT_SYMBOL(proc_remove);
678
679void *PDE_DATA(const struct inode *inode)
680{
681 return __PDE_DATA(inode);
682}
683EXPORT_SYMBOL(PDE_DATA);
1/*
2 * proc/fs/generic.c --- generic routines for the proc-fs
3 *
4 * This file contains generic proc-fs routines for handling
5 * directories and files.
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds.
8 * Copyright (C) 1997 Theodore Ts'o
9 */
10
11#include <linux/errno.h>
12#include <linux/time.h>
13#include <linux/proc_fs.h>
14#include <linux/stat.h>
15#include <linux/mm.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/printk.h>
19#include <linux/mount.h>
20#include <linux/init.h>
21#include <linux/idr.h>
22#include <linux/namei.h>
23#include <linux/bitops.h>
24#include <linux/spinlock.h>
25#include <linux/completion.h>
26#include <asm/uaccess.h>
27
28#include "internal.h"
29
30DEFINE_SPINLOCK(proc_subdir_lock);
31
32static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)
33{
34 if (de->namelen != len)
35 return 0;
36 return !memcmp(name, de->name, len);
37}
38
39static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
40{
41 struct inode *inode = dentry->d_inode;
42 struct proc_dir_entry *de = PDE(inode);
43 int error;
44
45 error = inode_change_ok(inode, iattr);
46 if (error)
47 return error;
48
49 setattr_copy(inode, iattr);
50 mark_inode_dirty(inode);
51
52 proc_set_user(de, inode->i_uid, inode->i_gid);
53 de->mode = inode->i_mode;
54 return 0;
55}
56
57static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
58 struct kstat *stat)
59{
60 struct inode *inode = dentry->d_inode;
61 struct proc_dir_entry *de = PROC_I(inode)->pde;
62 if (de && de->nlink)
63 set_nlink(inode, de->nlink);
64
65 generic_fillattr(inode, stat);
66 return 0;
67}
68
69static const struct inode_operations proc_file_inode_operations = {
70 .setattr = proc_notify_change,
71};
72
73/*
74 * This function parses a name such as "tty/driver/serial", and
75 * returns the struct proc_dir_entry for "/proc/tty/driver", and
76 * returns "serial" in residual.
77 */
78static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
79 const char **residual)
80{
81 const char *cp = name, *next;
82 struct proc_dir_entry *de;
83 unsigned int len;
84
85 de = *ret;
86 if (!de)
87 de = &proc_root;
88
89 while (1) {
90 next = strchr(cp, '/');
91 if (!next)
92 break;
93
94 len = next - cp;
95 for (de = de->subdir; de ; de = de->next) {
96 if (proc_match(len, cp, de))
97 break;
98 }
99 if (!de) {
100 WARN(1, "name '%s'\n", name);
101 return -ENOENT;
102 }
103 cp += len + 1;
104 }
105 *residual = cp;
106 *ret = de;
107 return 0;
108}
109
110static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
111 const char **residual)
112{
113 int rv;
114
115 spin_lock(&proc_subdir_lock);
116 rv = __xlate_proc_name(name, ret, residual);
117 spin_unlock(&proc_subdir_lock);
118 return rv;
119}
120
121static DEFINE_IDA(proc_inum_ida);
122static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
123
124#define PROC_DYNAMIC_FIRST 0xF0000000U
125
126/*
127 * Return an inode number between PROC_DYNAMIC_FIRST and
128 * 0xffffffff, or zero on failure.
129 */
130int proc_alloc_inum(unsigned int *inum)
131{
132 unsigned int i;
133 int error;
134
135retry:
136 if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
137 return -ENOMEM;
138
139 spin_lock_irq(&proc_inum_lock);
140 error = ida_get_new(&proc_inum_ida, &i);
141 spin_unlock_irq(&proc_inum_lock);
142 if (error == -EAGAIN)
143 goto retry;
144 else if (error)
145 return error;
146
147 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
148 spin_lock_irq(&proc_inum_lock);
149 ida_remove(&proc_inum_ida, i);
150 spin_unlock_irq(&proc_inum_lock);
151 return -ENOSPC;
152 }
153 *inum = PROC_DYNAMIC_FIRST + i;
154 return 0;
155}
156
157void proc_free_inum(unsigned int inum)
158{
159 unsigned long flags;
160 spin_lock_irqsave(&proc_inum_lock, flags);
161 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
162 spin_unlock_irqrestore(&proc_inum_lock, flags);
163}
164
165static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
166{
167 nd_set_link(nd, __PDE_DATA(dentry->d_inode));
168 return NULL;
169}
170
171static const struct inode_operations proc_link_inode_operations = {
172 .readlink = generic_readlink,
173 .follow_link = proc_follow_link,
174};
175
176/*
177 * Don't create negative dentries here, return -ENOENT by hand
178 * instead.
179 */
180struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
181 struct dentry *dentry)
182{
183 struct inode *inode;
184
185 spin_lock(&proc_subdir_lock);
186 for (de = de->subdir; de ; de = de->next) {
187 if (de->namelen != dentry->d_name.len)
188 continue;
189 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
190 pde_get(de);
191 spin_unlock(&proc_subdir_lock);
192 inode = proc_get_inode(dir->i_sb, de);
193 if (!inode)
194 return ERR_PTR(-ENOMEM);
195 d_set_d_op(dentry, &simple_dentry_operations);
196 d_add(dentry, inode);
197 return NULL;
198 }
199 }
200 spin_unlock(&proc_subdir_lock);
201 return ERR_PTR(-ENOENT);
202}
203
204struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
205 unsigned int flags)
206{
207 return proc_lookup_de(PDE(dir), dir, dentry);
208}
209
210/*
211 * This returns non-zero if at EOF, so that the /proc
212 * root directory can use this and check if it should
213 * continue with the <pid> entries..
214 *
215 * Note that the VFS-layer doesn't care about the return
216 * value of the readdir() call, as long as it's non-negative
217 * for success..
218 */
219int proc_readdir_de(struct proc_dir_entry *de, struct file *file,
220 struct dir_context *ctx)
221{
222 int i;
223
224 if (!dir_emit_dots(file, ctx))
225 return 0;
226
227 spin_lock(&proc_subdir_lock);
228 de = de->subdir;
229 i = ctx->pos - 2;
230 for (;;) {
231 if (!de) {
232 spin_unlock(&proc_subdir_lock);
233 return 0;
234 }
235 if (!i)
236 break;
237 de = de->next;
238 i--;
239 }
240
241 do {
242 struct proc_dir_entry *next;
243 pde_get(de);
244 spin_unlock(&proc_subdir_lock);
245 if (!dir_emit(ctx, de->name, de->namelen,
246 de->low_ino, de->mode >> 12)) {
247 pde_put(de);
248 return 0;
249 }
250 spin_lock(&proc_subdir_lock);
251 ctx->pos++;
252 next = de->next;
253 pde_put(de);
254 de = next;
255 } while (de);
256 spin_unlock(&proc_subdir_lock);
257 return 1;
258}
259
260int proc_readdir(struct file *file, struct dir_context *ctx)
261{
262 struct inode *inode = file_inode(file);
263
264 return proc_readdir_de(PDE(inode), file, ctx);
265}
266
267/*
268 * These are the generic /proc directory operations. They
269 * use the in-memory "struct proc_dir_entry" tree to parse
270 * the /proc directory.
271 */
272static const struct file_operations proc_dir_operations = {
273 .llseek = generic_file_llseek,
274 .read = generic_read_dir,
275 .iterate = proc_readdir,
276};
277
278/*
279 * proc directories can do almost nothing..
280 */
281static const struct inode_operations proc_dir_inode_operations = {
282 .lookup = proc_lookup,
283 .getattr = proc_getattr,
284 .setattr = proc_notify_change,
285};
286
287static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
288{
289 struct proc_dir_entry *tmp;
290 int ret;
291
292 ret = proc_alloc_inum(&dp->low_ino);
293 if (ret)
294 return ret;
295
296 if (S_ISDIR(dp->mode)) {
297 dp->proc_fops = &proc_dir_operations;
298 dp->proc_iops = &proc_dir_inode_operations;
299 dir->nlink++;
300 } else if (S_ISLNK(dp->mode)) {
301 dp->proc_iops = &proc_link_inode_operations;
302 } else if (S_ISREG(dp->mode)) {
303 BUG_ON(dp->proc_fops == NULL);
304 dp->proc_iops = &proc_file_inode_operations;
305 } else {
306 WARN_ON(1);
307 return -EINVAL;
308 }
309
310 spin_lock(&proc_subdir_lock);
311
312 for (tmp = dir->subdir; tmp; tmp = tmp->next)
313 if (strcmp(tmp->name, dp->name) == 0) {
314 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
315 dir->name, dp->name);
316 break;
317 }
318
319 dp->next = dir->subdir;
320 dp->parent = dir;
321 dir->subdir = dp;
322 spin_unlock(&proc_subdir_lock);
323
324 return 0;
325}
326
327static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
328 const char *name,
329 umode_t mode,
330 nlink_t nlink)
331{
332 struct proc_dir_entry *ent = NULL;
333 const char *fn = name;
334 unsigned int len;
335
336 /* make sure name is valid */
337 if (!name || !strlen(name))
338 goto out;
339
340 if (xlate_proc_name(name, parent, &fn) != 0)
341 goto out;
342
343 /* At this point there must not be any '/' characters beyond *fn */
344 if (strchr(fn, '/'))
345 goto out;
346
347 len = strlen(fn);
348
349 ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
350 if (!ent)
351 goto out;
352
353 memcpy(ent->name, fn, len + 1);
354 ent->namelen = len;
355 ent->mode = mode;
356 ent->nlink = nlink;
357 atomic_set(&ent->count, 1);
358 spin_lock_init(&ent->pde_unload_lock);
359 INIT_LIST_HEAD(&ent->pde_openers);
360out:
361 return ent;
362}
363
364struct proc_dir_entry *proc_symlink(const char *name,
365 struct proc_dir_entry *parent, const char *dest)
366{
367 struct proc_dir_entry *ent;
368
369 ent = __proc_create(&parent, name,
370 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
371
372 if (ent) {
373 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
374 if (ent->data) {
375 strcpy((char*)ent->data,dest);
376 if (proc_register(parent, ent) < 0) {
377 kfree(ent->data);
378 kfree(ent);
379 ent = NULL;
380 }
381 } else {
382 kfree(ent);
383 ent = NULL;
384 }
385 }
386 return ent;
387}
388EXPORT_SYMBOL(proc_symlink);
389
390struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
391 struct proc_dir_entry *parent, void *data)
392{
393 struct proc_dir_entry *ent;
394
395 if (mode == 0)
396 mode = S_IRUGO | S_IXUGO;
397
398 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
399 if (ent) {
400 ent->data = data;
401 if (proc_register(parent, ent) < 0) {
402 kfree(ent);
403 ent = NULL;
404 }
405 }
406 return ent;
407}
408EXPORT_SYMBOL_GPL(proc_mkdir_data);
409
410struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
411 struct proc_dir_entry *parent)
412{
413 return proc_mkdir_data(name, mode, parent, NULL);
414}
415EXPORT_SYMBOL(proc_mkdir_mode);
416
417struct proc_dir_entry *proc_mkdir(const char *name,
418 struct proc_dir_entry *parent)
419{
420 return proc_mkdir_data(name, 0, parent, NULL);
421}
422EXPORT_SYMBOL(proc_mkdir);
423
424struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
425 struct proc_dir_entry *parent,
426 const struct file_operations *proc_fops,
427 void *data)
428{
429 struct proc_dir_entry *pde;
430 if ((mode & S_IFMT) == 0)
431 mode |= S_IFREG;
432
433 if (!S_ISREG(mode)) {
434 WARN_ON(1); /* use proc_mkdir() */
435 return NULL;
436 }
437
438 if ((mode & S_IALLUGO) == 0)
439 mode |= S_IRUGO;
440 pde = __proc_create(&parent, name, mode, 1);
441 if (!pde)
442 goto out;
443 pde->proc_fops = proc_fops;
444 pde->data = data;
445 if (proc_register(parent, pde) < 0)
446 goto out_free;
447 return pde;
448out_free:
449 kfree(pde);
450out:
451 return NULL;
452}
453EXPORT_SYMBOL(proc_create_data);
454
455void proc_set_size(struct proc_dir_entry *de, loff_t size)
456{
457 de->size = size;
458}
459EXPORT_SYMBOL(proc_set_size);
460
461void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
462{
463 de->uid = uid;
464 de->gid = gid;
465}
466EXPORT_SYMBOL(proc_set_user);
467
468static void free_proc_entry(struct proc_dir_entry *de)
469{
470 proc_free_inum(de->low_ino);
471
472 if (S_ISLNK(de->mode))
473 kfree(de->data);
474 kfree(de);
475}
476
477void pde_put(struct proc_dir_entry *pde)
478{
479 if (atomic_dec_and_test(&pde->count))
480 free_proc_entry(pde);
481}
482
483/*
484 * Remove a /proc entry and free it if it's not currently in use.
485 */
486void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
487{
488 struct proc_dir_entry **p;
489 struct proc_dir_entry *de = NULL;
490 const char *fn = name;
491 unsigned int len;
492
493 spin_lock(&proc_subdir_lock);
494 if (__xlate_proc_name(name, &parent, &fn) != 0) {
495 spin_unlock(&proc_subdir_lock);
496 return;
497 }
498 len = strlen(fn);
499
500 for (p = &parent->subdir; *p; p=&(*p)->next ) {
501 if (proc_match(len, fn, *p)) {
502 de = *p;
503 *p = de->next;
504 de->next = NULL;
505 break;
506 }
507 }
508 spin_unlock(&proc_subdir_lock);
509 if (!de) {
510 WARN(1, "name '%s'\n", name);
511 return;
512 }
513
514 proc_entry_rundown(de);
515
516 if (S_ISDIR(de->mode))
517 parent->nlink--;
518 de->nlink = 0;
519 WARN(de->subdir, "%s: removing non-empty directory "
520 "'%s/%s', leaking at least '%s'\n", __func__,
521 de->parent->name, de->name, de->subdir->name);
522 pde_put(de);
523}
524EXPORT_SYMBOL(remove_proc_entry);
525
526int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
527{
528 struct proc_dir_entry **p;
529 struct proc_dir_entry *root = NULL, *de, *next;
530 const char *fn = name;
531 unsigned int len;
532
533 spin_lock(&proc_subdir_lock);
534 if (__xlate_proc_name(name, &parent, &fn) != 0) {
535 spin_unlock(&proc_subdir_lock);
536 return -ENOENT;
537 }
538 len = strlen(fn);
539
540 for (p = &parent->subdir; *p; p=&(*p)->next ) {
541 if (proc_match(len, fn, *p)) {
542 root = *p;
543 *p = root->next;
544 root->next = NULL;
545 break;
546 }
547 }
548 if (!root) {
549 spin_unlock(&proc_subdir_lock);
550 return -ENOENT;
551 }
552 de = root;
553 while (1) {
554 next = de->subdir;
555 if (next) {
556 de->subdir = next->next;
557 next->next = NULL;
558 de = next;
559 continue;
560 }
561 spin_unlock(&proc_subdir_lock);
562
563 proc_entry_rundown(de);
564 next = de->parent;
565 if (S_ISDIR(de->mode))
566 next->nlink--;
567 de->nlink = 0;
568 if (de == root)
569 break;
570 pde_put(de);
571
572 spin_lock(&proc_subdir_lock);
573 de = next;
574 }
575 pde_put(root);
576 return 0;
577}
578EXPORT_SYMBOL(remove_proc_subtree);
579
580void *proc_get_parent_data(const struct inode *inode)
581{
582 struct proc_dir_entry *de = PDE(inode);
583 return de->parent->data;
584}
585EXPORT_SYMBOL_GPL(proc_get_parent_data);
586
587void proc_remove(struct proc_dir_entry *de)
588{
589 if (de)
590 remove_proc_subtree(de->name, de->parent);
591}
592EXPORT_SYMBOL(proc_remove);
593
594void *PDE_DATA(const struct inode *inode)
595{
596 return __PDE_DATA(inode);
597}
598EXPORT_SYMBOL(PDE_DATA);