]>
Commit | Line | Data |
---|---|---|
77b14db5 EB |
1 | /* |
2 | * /proc/sys support | |
3 | */ | |
1e0edd3f | 4 | #include <linux/init.h> |
77b14db5 | 5 | #include <linux/sysctl.h> |
f1ecf068 | 6 | #include <linux/poll.h> |
77b14db5 | 7 | #include <linux/proc_fs.h> |
87ebdc00 | 8 | #include <linux/printk.h> |
77b14db5 | 9 | #include <linux/security.h> |
40401530 | 10 | #include <linux/sched.h> |
34286d66 | 11 | #include <linux/namei.h> |
40401530 | 12 | #include <linux/mm.h> |
1f87f0b5 | 13 | #include <linux/module.h> |
77b14db5 EB |
14 | #include "internal.h" |
15 | ||
d72f71eb | 16 | static const struct dentry_operations proc_sys_dentry_operations; |
77b14db5 | 17 | static const struct file_operations proc_sys_file_operations; |
03a44825 | 18 | static const struct inode_operations proc_sys_inode_operations; |
9043476f AV |
19 | static const struct file_operations proc_sys_dir_file_operations; |
20 | static const struct inode_operations proc_sys_dir_operations; | |
77b14db5 | 21 | |
f9bd6733 EB |
22 | /* Support for permanently empty directories */ |
23 | ||
24 | struct ctl_table sysctl_mount_point[] = { | |
25 | { } | |
26 | }; | |
27 | ||
28 | static bool is_empty_dir(struct ctl_table_header *head) | |
29 | { | |
30 | return head->ctl_table[0].child == sysctl_mount_point; | |
31 | } | |
32 | ||
33 | static void set_empty_dir(struct ctl_dir *dir) | |
34 | { | |
35 | dir->header.ctl_table[0].child = sysctl_mount_point; | |
36 | } | |
37 | ||
38 | static void clear_empty_dir(struct ctl_dir *dir) | |
39 | ||
40 | { | |
41 | dir->header.ctl_table[0].child = NULL; | |
42 | } | |
43 | ||
f1ecf068 LDM |
44 | void proc_sys_poll_notify(struct ctl_table_poll *poll) |
45 | { | |
46 | if (!poll) | |
47 | return; | |
48 | ||
49 | atomic_inc(&poll->event); | |
50 | wake_up_interruptible(&poll->wait); | |
51 | } | |
52 | ||
a194558e EB |
53 | static struct ctl_table root_table[] = { |
54 | { | |
55 | .procname = "", | |
7ec66d06 | 56 | .mode = S_IFDIR|S_IRUGO|S_IXUGO, |
a194558e EB |
57 | }, |
58 | { } | |
59 | }; | |
0e47c99d | 60 | static struct ctl_table_root sysctl_table_root = { |
0e47c99d | 61 | .default_set.dir.header = { |
7ec66d06 EB |
62 | {{.count = 1, |
63 | .nreg = 1, | |
ac13ac6f | 64 | .ctl_table = root_table }}, |
0e47c99d | 65 | .ctl_table_arg = root_table, |
7ec66d06 EB |
66 | .root = &sysctl_table_root, |
67 | .set = &sysctl_table_root.default_set, | |
68 | }, | |
1f87f0b5 | 69 | }; |
1f87f0b5 EB |
70 | |
71 | static DEFINE_SPINLOCK(sysctl_lock); | |
72 | ||
7ec66d06 | 73 | static void drop_sysctl_table(struct ctl_table_header *header); |
0e47c99d | 74 | static int sysctl_follow_link(struct ctl_table_header **phead, |
13bcc6a2 | 75 | struct ctl_table **pentry); |
0e47c99d EB |
76 | static int insert_links(struct ctl_table_header *head); |
77 | static void put_links(struct ctl_table_header *header); | |
7ec66d06 | 78 | |
6980128f EB |
79 | static void sysctl_print_dir(struct ctl_dir *dir) |
80 | { | |
81 | if (dir->header.parent) | |
82 | sysctl_print_dir(dir->header.parent); | |
87ebdc00 | 83 | pr_cont("%s/", dir->header.ctl_table[0].procname); |
6980128f EB |
84 | } |
85 | ||
076c3eed EB |
86 | static int namecmp(const char *name1, int len1, const char *name2, int len2) |
87 | { | |
88 | int minlen; | |
89 | int cmp; | |
90 | ||
91 | minlen = len1; | |
92 | if (minlen > len2) | |
93 | minlen = len2; | |
94 | ||
95 | cmp = memcmp(name1, name2, minlen); | |
96 | if (cmp == 0) | |
97 | cmp = len1 - len2; | |
98 | return cmp; | |
99 | } | |
100 | ||
60f126d9 | 101 | /* Called under sysctl_lock */ |
076c3eed | 102 | static struct ctl_table *find_entry(struct ctl_table_header **phead, |
0e47c99d | 103 | struct ctl_dir *dir, const char *name, int namelen) |
076c3eed EB |
104 | { |
105 | struct ctl_table_header *head; | |
106 | struct ctl_table *entry; | |
ac13ac6f | 107 | struct rb_node *node = dir->root.rb_node; |
076c3eed | 108 | |
ac13ac6f EB |
109 | while (node) |
110 | { | |
111 | struct ctl_node *ctl_node; | |
112 | const char *procname; | |
113 | int cmp; | |
114 | ||
115 | ctl_node = rb_entry(node, struct ctl_node, node); | |
116 | head = ctl_node->header; | |
117 | entry = &head->ctl_table[ctl_node - head->node]; | |
118 | procname = entry->procname; | |
119 | ||
120 | cmp = namecmp(name, namelen, procname, strlen(procname)); | |
121 | if (cmp < 0) | |
122 | node = node->rb_left; | |
123 | else if (cmp > 0) | |
124 | node = node->rb_right; | |
125 | else { | |
126 | *phead = head; | |
127 | return entry; | |
076c3eed EB |
128 | } |
129 | } | |
130 | return NULL; | |
131 | } | |
132 | ||
ac13ac6f EB |
133 | static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) |
134 | { | |
135 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
136 | struct rb_node **p = &head->parent->root.rb_node; | |
137 | struct rb_node *parent = NULL; | |
138 | const char *name = entry->procname; | |
139 | int namelen = strlen(name); | |
140 | ||
141 | while (*p) { | |
142 | struct ctl_table_header *parent_head; | |
143 | struct ctl_table *parent_entry; | |
144 | struct ctl_node *parent_node; | |
145 | const char *parent_name; | |
146 | int cmp; | |
147 | ||
148 | parent = *p; | |
149 | parent_node = rb_entry(parent, struct ctl_node, node); | |
150 | parent_head = parent_node->header; | |
151 | parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; | |
152 | parent_name = parent_entry->procname; | |
153 | ||
154 | cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); | |
155 | if (cmp < 0) | |
156 | p = &(*p)->rb_left; | |
157 | else if (cmp > 0) | |
158 | p = &(*p)->rb_right; | |
159 | else { | |
87ebdc00 | 160 | pr_err("sysctl duplicate entry: "); |
ac13ac6f | 161 | sysctl_print_dir(head->parent); |
87ebdc00 | 162 | pr_cont("/%s\n", entry->procname); |
ac13ac6f EB |
163 | return -EEXIST; |
164 | } | |
165 | } | |
166 | ||
167 | rb_link_node(node, parent, p); | |
ea5272f5 | 168 | rb_insert_color(node, &head->parent->root); |
ac13ac6f EB |
169 | return 0; |
170 | } | |
171 | ||
172 | static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) | |
173 | { | |
174 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
175 | ||
176 | rb_erase(node, &head->parent->root); | |
177 | } | |
178 | ||
e0d04529 EB |
179 | static void init_header(struct ctl_table_header *head, |
180 | struct ctl_table_root *root, struct ctl_table_set *set, | |
ac13ac6f | 181 | struct ctl_node *node, struct ctl_table *table) |
e0d04529 | 182 | { |
7ec66d06 | 183 | head->ctl_table = table; |
e0d04529 | 184 | head->ctl_table_arg = table; |
e0d04529 EB |
185 | head->used = 0; |
186 | head->count = 1; | |
187 | head->nreg = 1; | |
188 | head->unregistering = NULL; | |
189 | head->root = root; | |
190 | head->set = set; | |
191 | head->parent = NULL; | |
ac13ac6f | 192 | head->node = node; |
d6cffbbe | 193 | INIT_LIST_HEAD(&head->inodes); |
ac13ac6f EB |
194 | if (node) { |
195 | struct ctl_table *entry; | |
4c199a93 | 196 | for (entry = table; entry->procname; entry++, node++) |
ac13ac6f | 197 | node->header = head; |
ac13ac6f | 198 | } |
e0d04529 EB |
199 | } |
200 | ||
8425d6aa EB |
201 | static void erase_header(struct ctl_table_header *head) |
202 | { | |
ac13ac6f EB |
203 | struct ctl_table *entry; |
204 | for (entry = head->ctl_table; entry->procname; entry++) | |
205 | erase_entry(head, entry); | |
8425d6aa EB |
206 | } |
207 | ||
0e47c99d | 208 | static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) |
8425d6aa | 209 | { |
ac13ac6f | 210 | struct ctl_table *entry; |
0e47c99d EB |
211 | int err; |
212 | ||
f9bd6733 EB |
213 | /* Is this a permanently empty directory? */ |
214 | if (is_empty_dir(&dir->header)) | |
215 | return -EROFS; | |
216 | ||
217 | /* Am I creating a permanently empty directory? */ | |
218 | if (header->ctl_table == sysctl_mount_point) { | |
219 | if (!RB_EMPTY_ROOT(&dir->root)) | |
220 | return -EINVAL; | |
221 | set_empty_dir(dir); | |
222 | } | |
223 | ||
0e47c99d | 224 | dir->header.nreg++; |
7ec66d06 | 225 | header->parent = dir; |
0e47c99d EB |
226 | err = insert_links(header); |
227 | if (err) | |
228 | goto fail_links; | |
ac13ac6f EB |
229 | for (entry = header->ctl_table; entry->procname; entry++) { |
230 | err = insert_entry(header, entry); | |
231 | if (err) | |
232 | goto fail; | |
233 | } | |
0e47c99d | 234 | return 0; |
ac13ac6f EB |
235 | fail: |
236 | erase_header(header); | |
237 | put_links(header); | |
0e47c99d | 238 | fail_links: |
f9bd6733 EB |
239 | if (header->ctl_table == sysctl_mount_point) |
240 | clear_empty_dir(dir); | |
0e47c99d EB |
241 | header->parent = NULL; |
242 | drop_sysctl_table(&dir->header); | |
243 | return err; | |
8425d6aa EB |
244 | } |
245 | ||
1f87f0b5 EB |
246 | /* called under sysctl_lock */ |
247 | static int use_table(struct ctl_table_header *p) | |
248 | { | |
249 | if (unlikely(p->unregistering)) | |
250 | return 0; | |
251 | p->used++; | |
252 | return 1; | |
253 | } | |
254 | ||
255 | /* called under sysctl_lock */ | |
256 | static void unuse_table(struct ctl_table_header *p) | |
257 | { | |
258 | if (!--p->used) | |
259 | if (unlikely(p->unregistering)) | |
260 | complete(p->unregistering); | |
261 | } | |
262 | ||
d6cffbbe KK |
263 | /* called under sysctl_lock */ |
264 | static void proc_sys_prune_dcache(struct ctl_table_header *head) | |
265 | { | |
266 | struct inode *inode, *prev = NULL; | |
267 | struct proc_inode *ei; | |
268 | ||
269 | list_for_each_entry(ei, &head->inodes, sysctl_inodes) { | |
270 | inode = igrab(&ei->vfs_inode); | |
271 | if (inode) { | |
272 | spin_unlock(&sysctl_lock); | |
273 | iput(prev); | |
274 | prev = inode; | |
275 | d_prune_aliases(inode); | |
276 | spin_lock(&sysctl_lock); | |
277 | } | |
278 | } | |
279 | if (prev) { | |
280 | spin_unlock(&sysctl_lock); | |
281 | iput(prev); | |
282 | spin_lock(&sysctl_lock); | |
283 | } | |
284 | } | |
285 | ||
1f87f0b5 EB |
286 | /* called under sysctl_lock, will reacquire if has to wait */ |
287 | static void start_unregistering(struct ctl_table_header *p) | |
288 | { | |
289 | /* | |
290 | * if p->used is 0, nobody will ever touch that entry again; | |
291 | * we'll eliminate all paths to it before dropping sysctl_lock | |
292 | */ | |
293 | if (unlikely(p->used)) { | |
294 | struct completion wait; | |
295 | init_completion(&wait); | |
296 | p->unregistering = &wait; | |
297 | spin_unlock(&sysctl_lock); | |
298 | wait_for_completion(&wait); | |
299 | spin_lock(&sysctl_lock); | |
300 | } else { | |
301 | /* anything non-NULL; we'll never dereference it */ | |
302 | p->unregistering = ERR_PTR(-EINVAL); | |
303 | } | |
d6cffbbe KK |
304 | /* |
305 | * Prune dentries for unregistered sysctls: namespaced sysctls | |
306 | * can have duplicate names and contaminate dcache very badly. | |
307 | */ | |
308 | proc_sys_prune_dcache(p); | |
1f87f0b5 EB |
309 | /* |
310 | * do not remove from the list until nobody holds it; walking the | |
311 | * list in do_sysctl() relies on that. | |
312 | */ | |
8425d6aa | 313 | erase_header(p); |
1f87f0b5 EB |
314 | } |
315 | ||
1f87f0b5 EB |
316 | static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) |
317 | { | |
ab4a1f24 | 318 | BUG_ON(!head); |
1f87f0b5 EB |
319 | spin_lock(&sysctl_lock); |
320 | if (!use_table(head)) | |
321 | head = ERR_PTR(-ENOENT); | |
322 | spin_unlock(&sysctl_lock); | |
323 | return head; | |
324 | } | |
325 | ||
326 | static void sysctl_head_finish(struct ctl_table_header *head) | |
327 | { | |
328 | if (!head) | |
329 | return; | |
330 | spin_lock(&sysctl_lock); | |
331 | unuse_table(head); | |
332 | spin_unlock(&sysctl_lock); | |
333 | } | |
334 | ||
335 | static struct ctl_table_set * | |
13bcc6a2 | 336 | lookup_header_set(struct ctl_table_root *root) |
1f87f0b5 EB |
337 | { |
338 | struct ctl_table_set *set = &root->default_set; | |
339 | if (root->lookup) | |
13bcc6a2 | 340 | set = root->lookup(root); |
1f87f0b5 EB |
341 | return set; |
342 | } | |
343 | ||
076c3eed | 344 | static struct ctl_table *lookup_entry(struct ctl_table_header **phead, |
7ec66d06 | 345 | struct ctl_dir *dir, |
076c3eed EB |
346 | const char *name, int namelen) |
347 | { | |
348 | struct ctl_table_header *head; | |
349 | struct ctl_table *entry; | |
076c3eed EB |
350 | |
351 | spin_lock(&sysctl_lock); | |
0e47c99d EB |
352 | entry = find_entry(&head, dir, name, namelen); |
353 | if (entry && use_table(head)) | |
354 | *phead = head; | |
355 | else | |
356 | entry = NULL; | |
076c3eed EB |
357 | spin_unlock(&sysctl_lock); |
358 | return entry; | |
359 | } | |
360 | ||
ac13ac6f | 361 | static struct ctl_node *first_usable_entry(struct rb_node *node) |
1f87f0b5 | 362 | { |
ac13ac6f | 363 | struct ctl_node *ctl_node; |
1f87f0b5 | 364 | |
ac13ac6f EB |
365 | for (;node; node = rb_next(node)) { |
366 | ctl_node = rb_entry(node, struct ctl_node, node); | |
367 | if (use_table(ctl_node->header)) | |
368 | return ctl_node; | |
1f87f0b5 | 369 | } |
1f87f0b5 EB |
370 | return NULL; |
371 | } | |
372 | ||
7ec66d06 | 373 | static void first_entry(struct ctl_dir *dir, |
6a75ce16 EB |
374 | struct ctl_table_header **phead, struct ctl_table **pentry) |
375 | { | |
ac13ac6f | 376 | struct ctl_table_header *head = NULL; |
7ec66d06 | 377 | struct ctl_table *entry = NULL; |
ac13ac6f | 378 | struct ctl_node *ctl_node; |
6a75ce16 EB |
379 | |
380 | spin_lock(&sysctl_lock); | |
ac13ac6f | 381 | ctl_node = first_usable_entry(rb_first(&dir->root)); |
6a75ce16 | 382 | spin_unlock(&sysctl_lock); |
ac13ac6f EB |
383 | if (ctl_node) { |
384 | head = ctl_node->header; | |
385 | entry = &head->ctl_table[ctl_node - head->node]; | |
386 | } | |
6a75ce16 EB |
387 | *phead = head; |
388 | *pentry = entry; | |
389 | } | |
390 | ||
7ec66d06 | 391 | static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) |
1f87f0b5 | 392 | { |
6a75ce16 EB |
393 | struct ctl_table_header *head = *phead; |
394 | struct ctl_table *entry = *pentry; | |
ac13ac6f | 395 | struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; |
6a75ce16 | 396 | |
ac13ac6f EB |
397 | spin_lock(&sysctl_lock); |
398 | unuse_table(head); | |
399 | ||
400 | ctl_node = first_usable_entry(rb_next(&ctl_node->node)); | |
401 | spin_unlock(&sysctl_lock); | |
402 | head = NULL; | |
403 | if (ctl_node) { | |
404 | head = ctl_node->header; | |
405 | entry = &head->ctl_table[ctl_node - head->node]; | |
6a75ce16 EB |
406 | } |
407 | *phead = head; | |
408 | *pentry = entry; | |
1f87f0b5 EB |
409 | } |
410 | ||
411 | void register_sysctl_root(struct ctl_table_root *root) | |
412 | { | |
1f87f0b5 EB |
413 | } |
414 | ||
415 | /* | |
416 | * sysctl_perm does NOT grant the superuser all rights automatically, because | |
417 | * some sysctl variables are readonly even to root. | |
418 | */ | |
419 | ||
420 | static int test_perm(int mode, int op) | |
421 | { | |
091bd3ea | 422 | if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) |
1f87f0b5 | 423 | mode >>= 6; |
091bd3ea | 424 | else if (in_egroup_p(GLOBAL_ROOT_GID)) |
1f87f0b5 EB |
425 | mode >>= 3; |
426 | if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) | |
427 | return 0; | |
428 | return -EACCES; | |
429 | } | |
430 | ||
73f7ef43 | 431 | static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) |
1f87f0b5 | 432 | { |
73f7ef43 | 433 | struct ctl_table_root *root = head->root; |
1f87f0b5 EB |
434 | int mode; |
435 | ||
436 | if (root->permissions) | |
73f7ef43 | 437 | mode = root->permissions(head, table); |
1f87f0b5 EB |
438 | else |
439 | mode = table->mode; | |
440 | ||
441 | return test_perm(mode, op); | |
442 | } | |
443 | ||
9043476f AV |
444 | static struct inode *proc_sys_make_inode(struct super_block *sb, |
445 | struct ctl_table_header *head, struct ctl_table *table) | |
77b14db5 | 446 | { |
e79c6a4f | 447 | struct ctl_table_root *root = head->root; |
77b14db5 | 448 | struct inode *inode; |
9043476f | 449 | struct proc_inode *ei; |
77b14db5 | 450 | |
9043476f | 451 | inode = new_inode(sb); |
77b14db5 EB |
452 | if (!inode) |
453 | goto out; | |
454 | ||
85fe4025 CH |
455 | inode->i_ino = get_next_ino(); |
456 | ||
77b14db5 | 457 | ei = PROC_I(inode); |
9043476f AV |
458 | ei->sysctl = head; |
459 | ei->sysctl_entry = table; | |
460 | ||
d6cffbbe KK |
461 | spin_lock(&sysctl_lock); |
462 | list_add(&ei->sysctl_inodes, &head->inodes); | |
463 | head->count++; | |
464 | spin_unlock(&sysctl_lock); | |
465 | ||
078cd827 | 466 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
9043476f | 467 | inode->i_mode = table->mode; |
7ec66d06 | 468 | if (!S_ISDIR(table->mode)) { |
9043476f AV |
469 | inode->i_mode |= S_IFREG; |
470 | inode->i_op = &proc_sys_inode_operations; | |
471 | inode->i_fop = &proc_sys_file_operations; | |
472 | } else { | |
473 | inode->i_mode |= S_IFDIR; | |
9043476f AV |
474 | inode->i_op = &proc_sys_dir_operations; |
475 | inode->i_fop = &proc_sys_dir_file_operations; | |
f9bd6733 EB |
476 | if (is_empty_dir(head)) |
477 | make_empty_dir_inode(inode); | |
9043476f | 478 | } |
e79c6a4f DT |
479 | |
480 | if (root->set_ownership) | |
481 | root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); | |
482 | ||
77b14db5 EB |
483 | out: |
484 | return inode; | |
485 | } | |
486 | ||
d6cffbbe KK |
487 | void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) |
488 | { | |
489 | spin_lock(&sysctl_lock); | |
490 | list_del(&PROC_I(inode)->sysctl_inodes); | |
491 | if (!--head->count) | |
492 | kfree_rcu(head, rcu); | |
493 | spin_unlock(&sysctl_lock); | |
494 | } | |
495 | ||
81324364 | 496 | static struct ctl_table_header *grab_header(struct inode *inode) |
77b14db5 | 497 | { |
3cc3e046 EB |
498 | struct ctl_table_header *head = PROC_I(inode)->sysctl; |
499 | if (!head) | |
0e47c99d | 500 | head = &sysctl_table_root.default_set.dir.header; |
3cc3e046 | 501 | return sysctl_head_grab(head); |
9043476f | 502 | } |
77b14db5 | 503 | |
9043476f | 504 | static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3 | 505 | unsigned int flags) |
9043476f AV |
506 | { |
507 | struct ctl_table_header *head = grab_header(dir); | |
9043476f | 508 | struct ctl_table_header *h = NULL; |
dc12e909 | 509 | const struct qstr *name = &dentry->d_name; |
9043476f AV |
510 | struct ctl_table *p; |
511 | struct inode *inode; | |
512 | struct dentry *err = ERR_PTR(-ENOENT); | |
7ec66d06 | 513 | struct ctl_dir *ctl_dir; |
0e47c99d | 514 | int ret; |
77b14db5 | 515 | |
9043476f AV |
516 | if (IS_ERR(head)) |
517 | return ERR_CAST(head); | |
77b14db5 | 518 | |
7ec66d06 | 519 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 520 | |
7ec66d06 | 521 | p = lookup_entry(&h, ctl_dir, name->name, name->len); |
9043476f | 522 | if (!p) |
77b14db5 EB |
523 | goto out; |
524 | ||
4e757320 | 525 | if (S_ISLNK(p->mode)) { |
13bcc6a2 | 526 | ret = sysctl_follow_link(&h, &p); |
4e757320 EB |
527 | err = ERR_PTR(ret); |
528 | if (ret) | |
529 | goto out; | |
530 | } | |
0e47c99d | 531 | |
77b14db5 | 532 | err = ERR_PTR(-ENOMEM); |
9043476f | 533 | inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); |
77b14db5 EB |
534 | if (!inode) |
535 | goto out; | |
536 | ||
537 | err = NULL; | |
fb045adb | 538 | d_set_d_op(dentry, &proc_sys_dentry_operations); |
77b14db5 EB |
539 | d_add(dentry, inode); |
540 | ||
541 | out: | |
6bf61045 FR |
542 | if (h) |
543 | sysctl_head_finish(h); | |
77b14db5 EB |
544 | sysctl_head_finish(head); |
545 | return err; | |
546 | } | |
547 | ||
7708bfb1 PE |
548 | static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, |
549 | size_t count, loff_t *ppos, int write) | |
77b14db5 | 550 | { |
496ad9aa | 551 | struct inode *inode = file_inode(filp); |
9043476f AV |
552 | struct ctl_table_header *head = grab_header(inode); |
553 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
2a2da53b DH |
554 | ssize_t error; |
555 | size_t res; | |
77b14db5 | 556 | |
9043476f AV |
557 | if (IS_ERR(head)) |
558 | return PTR_ERR(head); | |
77b14db5 EB |
559 | |
560 | /* | |
561 | * At this point we know that the sysctl was not unregistered | |
562 | * and won't be until we finish. | |
563 | */ | |
564 | error = -EPERM; | |
73f7ef43 | 565 | if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) |
77b14db5 EB |
566 | goto out; |
567 | ||
9043476f AV |
568 | /* if that can happen at all, it should be -EINVAL, not -EISDIR */ |
569 | error = -EINVAL; | |
570 | if (!table->proc_handler) | |
571 | goto out; | |
572 | ||
77b14db5 EB |
573 | /* careful: calling conventions are nasty here */ |
574 | res = count; | |
8d65af78 | 575 | error = table->proc_handler(table, write, buf, &res, ppos); |
77b14db5 EB |
576 | if (!error) |
577 | error = res; | |
578 | out: | |
579 | sysctl_head_finish(head); | |
580 | ||
581 | return error; | |
582 | } | |
583 | ||
7708bfb1 | 584 | static ssize_t proc_sys_read(struct file *filp, char __user *buf, |
77b14db5 EB |
585 | size_t count, loff_t *ppos) |
586 | { | |
7708bfb1 PE |
587 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); |
588 | } | |
77b14db5 | 589 | |
7708bfb1 PE |
590 | static ssize_t proc_sys_write(struct file *filp, const char __user *buf, |
591 | size_t count, loff_t *ppos) | |
592 | { | |
593 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); | |
77b14db5 EB |
594 | } |
595 | ||
f1ecf068 LDM |
596 | static int proc_sys_open(struct inode *inode, struct file *filp) |
597 | { | |
4e474a00 | 598 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 LDM |
599 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
600 | ||
4e474a00 LDM |
601 | /* sysctl was unregistered */ |
602 | if (IS_ERR(head)) | |
603 | return PTR_ERR(head); | |
604 | ||
f1ecf068 LDM |
605 | if (table->poll) |
606 | filp->private_data = proc_sys_poll_event(table->poll); | |
607 | ||
4e474a00 LDM |
608 | sysctl_head_finish(head); |
609 | ||
f1ecf068 LDM |
610 | return 0; |
611 | } | |
612 | ||
613 | static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) | |
614 | { | |
496ad9aa | 615 | struct inode *inode = file_inode(filp); |
4e474a00 | 616 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 | 617 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
f1ecf068 | 618 | unsigned int ret = DEFAULT_POLLMASK; |
4e474a00 LDM |
619 | unsigned long event; |
620 | ||
621 | /* sysctl was unregistered */ | |
622 | if (IS_ERR(head)) | |
623 | return POLLERR | POLLHUP; | |
f1ecf068 LDM |
624 | |
625 | if (!table->proc_handler) | |
626 | goto out; | |
627 | ||
628 | if (!table->poll) | |
629 | goto out; | |
630 | ||
4e474a00 | 631 | event = (unsigned long)filp->private_data; |
f1ecf068 LDM |
632 | poll_wait(filp, &table->poll->wait, wait); |
633 | ||
634 | if (event != atomic_read(&table->poll->event)) { | |
635 | filp->private_data = proc_sys_poll_event(table->poll); | |
636 | ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; | |
637 | } | |
638 | ||
639 | out: | |
4e474a00 LDM |
640 | sysctl_head_finish(head); |
641 | ||
f1ecf068 LDM |
642 | return ret; |
643 | } | |
77b14db5 | 644 | |
f0c3b509 AV |
645 | static bool proc_sys_fill_cache(struct file *file, |
646 | struct dir_context *ctx, | |
9043476f AV |
647 | struct ctl_table_header *head, |
648 | struct ctl_table *table) | |
77b14db5 | 649 | { |
f0c3b509 | 650 | struct dentry *child, *dir = file->f_path.dentry; |
77b14db5 EB |
651 | struct inode *inode; |
652 | struct qstr qname; | |
653 | ino_t ino = 0; | |
654 | unsigned type = DT_UNKNOWN; | |
77b14db5 EB |
655 | |
656 | qname.name = table->procname; | |
657 | qname.len = strlen(table->procname); | |
8387ff25 | 658 | qname.hash = full_name_hash(dir, qname.name, qname.len); |
77b14db5 | 659 | |
77b14db5 EB |
660 | child = d_lookup(dir, &qname); |
661 | if (!child) { | |
76aab3ab AV |
662 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
663 | child = d_alloc_parallel(dir, &qname, &wq); | |
664 | if (IS_ERR(child)) | |
665 | return false; | |
666 | if (d_in_lookup(child)) { | |
9043476f AV |
667 | inode = proc_sys_make_inode(dir->d_sb, head, table); |
668 | if (!inode) { | |
76aab3ab | 669 | d_lookup_done(child); |
9043476f | 670 | dput(child); |
f0c3b509 | 671 | return false; |
77b14db5 | 672 | } |
76aab3ab AV |
673 | d_set_d_op(child, &proc_sys_dentry_operations); |
674 | d_add(child, inode); | |
77b14db5 EB |
675 | } |
676 | } | |
2b0143b5 | 677 | inode = d_inode(child); |
9043476f AV |
678 | ino = inode->i_ino; |
679 | type = inode->i_mode >> 12; | |
77b14db5 | 680 | dput(child); |
f0c3b509 | 681 | return dir_emit(ctx, qname.name, qname.len, ino, type); |
9043476f AV |
682 | } |
683 | ||
f0c3b509 AV |
684 | static bool proc_sys_link_fill_cache(struct file *file, |
685 | struct dir_context *ctx, | |
0e47c99d EB |
686 | struct ctl_table_header *head, |
687 | struct ctl_table *table) | |
688 | { | |
f0c3b509 | 689 | bool ret = true; |
0e47c99d EB |
690 | head = sysctl_head_grab(head); |
691 | ||
4e757320 EB |
692 | if (S_ISLNK(table->mode)) { |
693 | /* It is not an error if we can not follow the link ignore it */ | |
13bcc6a2 | 694 | int err = sysctl_follow_link(&head, &table); |
4e757320 EB |
695 | if (err) |
696 | goto out; | |
697 | } | |
0e47c99d | 698 | |
f0c3b509 | 699 | ret = proc_sys_fill_cache(file, ctx, head, table); |
0e47c99d EB |
700 | out: |
701 | sysctl_head_finish(head); | |
702 | return ret; | |
703 | } | |
704 | ||
e5eea098 | 705 | static int scan(struct ctl_table_header *head, struct ctl_table *table, |
9043476f | 706 | unsigned long *pos, struct file *file, |
f0c3b509 | 707 | struct dir_context *ctx) |
9043476f | 708 | { |
f0c3b509 | 709 | bool res; |
9043476f | 710 | |
f0c3b509 AV |
711 | if ((*pos)++ < ctx->pos) |
712 | return true; | |
9043476f | 713 | |
0e47c99d | 714 | if (unlikely(S_ISLNK(table->mode))) |
f0c3b509 | 715 | res = proc_sys_link_fill_cache(file, ctx, head, table); |
0e47c99d | 716 | else |
f0c3b509 | 717 | res = proc_sys_fill_cache(file, ctx, head, table); |
9043476f | 718 | |
f0c3b509 AV |
719 | if (res) |
720 | ctx->pos = *pos; | |
9043476f | 721 | |
6a75ce16 | 722 | return res; |
77b14db5 EB |
723 | } |
724 | ||
f0c3b509 | 725 | static int proc_sys_readdir(struct file *file, struct dir_context *ctx) |
77b14db5 | 726 | { |
f0c3b509 | 727 | struct ctl_table_header *head = grab_header(file_inode(file)); |
9043476f | 728 | struct ctl_table_header *h = NULL; |
6a75ce16 | 729 | struct ctl_table *entry; |
7ec66d06 | 730 | struct ctl_dir *ctl_dir; |
77b14db5 | 731 | unsigned long pos; |
9043476f AV |
732 | |
733 | if (IS_ERR(head)) | |
734 | return PTR_ERR(head); | |
77b14db5 | 735 | |
7ec66d06 | 736 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 737 | |
f0c3b509 | 738 | if (!dir_emit_dots(file, ctx)) |
93362fa4 | 739 | goto out; |
f0c3b509 | 740 | |
77b14db5 EB |
741 | pos = 2; |
742 | ||
7ec66d06 | 743 | for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { |
f0c3b509 | 744 | if (!scan(h, entry, &pos, file, ctx)) { |
9043476f AV |
745 | sysctl_head_finish(h); |
746 | break; | |
77b14db5 EB |
747 | } |
748 | } | |
93362fa4 | 749 | out: |
77b14db5 | 750 | sysctl_head_finish(head); |
f0c3b509 | 751 | return 0; |
77b14db5 EB |
752 | } |
753 | ||
10556cb2 | 754 | static int proc_sys_permission(struct inode *inode, int mask) |
77b14db5 EB |
755 | { |
756 | /* | |
757 | * sysctl entries that are not writeable, | |
758 | * are _NOT_ writeable, capabilities or not. | |
759 | */ | |
f696a365 MS |
760 | struct ctl_table_header *head; |
761 | struct ctl_table *table; | |
77b14db5 EB |
762 | int error; |
763 | ||
f696a365 MS |
764 | /* Executable files are not allowed under /proc/sys/ */ |
765 | if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) | |
766 | return -EACCES; | |
767 | ||
768 | head = grab_header(inode); | |
9043476f AV |
769 | if (IS_ERR(head)) |
770 | return PTR_ERR(head); | |
77b14db5 | 771 | |
f696a365 | 772 | table = PROC_I(inode)->sysctl_entry; |
9043476f AV |
773 | if (!table) /* global root - r-xr-xr-x */ |
774 | error = mask & MAY_WRITE ? -EACCES : 0; | |
775 | else /* Use the permissions on the sysctl table entry */ | |
73f7ef43 | 776 | error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); |
77b14db5 | 777 | |
77b14db5 EB |
778 | sysctl_head_finish(head); |
779 | return error; | |
780 | } | |
781 | ||
782 | static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) | |
783 | { | |
2b0143b5 | 784 | struct inode *inode = d_inode(dentry); |
77b14db5 EB |
785 | int error; |
786 | ||
787 | if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) | |
788 | return -EPERM; | |
789 | ||
31051c85 | 790 | error = setattr_prepare(dentry, attr); |
1025774c CH |
791 | if (error) |
792 | return error; | |
793 | ||
1025774c CH |
794 | setattr_copy(inode, attr); |
795 | mark_inode_dirty(inode); | |
796 | return 0; | |
77b14db5 EB |
797 | } |
798 | ||
9043476f AV |
799 | static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
800 | { | |
2b0143b5 | 801 | struct inode *inode = d_inode(dentry); |
9043476f AV |
802 | struct ctl_table_header *head = grab_header(inode); |
803 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
804 | ||
805 | if (IS_ERR(head)) | |
806 | return PTR_ERR(head); | |
807 | ||
808 | generic_fillattr(inode, stat); | |
809 | if (table) | |
810 | stat->mode = (stat->mode & S_IFMT) | table->mode; | |
811 | ||
812 | sysctl_head_finish(head); | |
813 | return 0; | |
814 | } | |
815 | ||
77b14db5 | 816 | static const struct file_operations proc_sys_file_operations = { |
f1ecf068 LDM |
817 | .open = proc_sys_open, |
818 | .poll = proc_sys_poll, | |
77b14db5 EB |
819 | .read = proc_sys_read, |
820 | .write = proc_sys_write, | |
6038f373 | 821 | .llseek = default_llseek, |
9043476f AV |
822 | }; |
823 | ||
824 | static const struct file_operations proc_sys_dir_file_operations = { | |
887df078 | 825 | .read = generic_read_dir, |
f50752ea | 826 | .iterate_shared = proc_sys_readdir, |
3222a3e5 | 827 | .llseek = generic_file_llseek, |
77b14db5 EB |
828 | }; |
829 | ||
03a44825 | 830 | static const struct inode_operations proc_sys_inode_operations = { |
9043476f AV |
831 | .permission = proc_sys_permission, |
832 | .setattr = proc_sys_setattr, | |
833 | .getattr = proc_sys_getattr, | |
834 | }; | |
835 | ||
836 | static const struct inode_operations proc_sys_dir_operations = { | |
77b14db5 EB |
837 | .lookup = proc_sys_lookup, |
838 | .permission = proc_sys_permission, | |
839 | .setattr = proc_sys_setattr, | |
9043476f | 840 | .getattr = proc_sys_getattr, |
77b14db5 EB |
841 | }; |
842 | ||
0b728e19 | 843 | static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) |
77b14db5 | 844 | { |
0b728e19 | 845 | if (flags & LOOKUP_RCU) |
34286d66 | 846 | return -ECHILD; |
2b0143b5 | 847 | return !PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
848 | } |
849 | ||
fe15ce44 | 850 | static int proc_sys_delete(const struct dentry *dentry) |
9043476f | 851 | { |
2b0143b5 | 852 | return !!PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
853 | } |
854 | ||
1f87f0b5 EB |
855 | static int sysctl_is_seen(struct ctl_table_header *p) |
856 | { | |
857 | struct ctl_table_set *set = p->set; | |
858 | int res; | |
859 | spin_lock(&sysctl_lock); | |
860 | if (p->unregistering) | |
861 | res = 0; | |
862 | else if (!set->is_seen) | |
863 | res = 1; | |
864 | else | |
865 | res = set->is_seen(set); | |
866 | spin_unlock(&sysctl_lock); | |
867 | return res; | |
868 | } | |
869 | ||
6fa67e70 | 870 | static int proc_sys_compare(const struct dentry *dentry, |
621e155a | 871 | unsigned int len, const char *str, const struct qstr *name) |
9043476f | 872 | { |
dfef6dcd | 873 | struct ctl_table_header *head; |
da53be12 LT |
874 | struct inode *inode; |
875 | ||
31e6b01f NP |
876 | /* Although proc doesn't have negative dentries, rcu-walk means |
877 | * that inode here can be NULL */ | |
dfef6dcd | 878 | /* AV: can it, indeed? */ |
2b0143b5 | 879 | inode = d_inode_rcu(dentry); |
31e6b01f | 880 | if (!inode) |
dfef6dcd | 881 | return 1; |
621e155a | 882 | if (name->len != len) |
9043476f | 883 | return 1; |
621e155a | 884 | if (memcmp(name->name, str, len)) |
9043476f | 885 | return 1; |
dfef6dcd AV |
886 | head = rcu_dereference(PROC_I(inode)->sysctl); |
887 | return !head || !sysctl_is_seen(head); | |
77b14db5 EB |
888 | } |
889 | ||
d72f71eb | 890 | static const struct dentry_operations proc_sys_dentry_operations = { |
77b14db5 | 891 | .d_revalidate = proc_sys_revalidate, |
9043476f AV |
892 | .d_delete = proc_sys_delete, |
893 | .d_compare = proc_sys_compare, | |
77b14db5 EB |
894 | }; |
895 | ||
0e47c99d EB |
896 | static struct ctl_dir *find_subdir(struct ctl_dir *dir, |
897 | const char *name, int namelen) | |
1f87f0b5 | 898 | { |
7ec66d06 EB |
899 | struct ctl_table_header *head; |
900 | struct ctl_table *entry; | |
1f87f0b5 | 901 | |
0e47c99d | 902 | entry = find_entry(&head, dir, name, namelen); |
7ec66d06 EB |
903 | if (!entry) |
904 | return ERR_PTR(-ENOENT); | |
51f72f4a EB |
905 | if (!S_ISDIR(entry->mode)) |
906 | return ERR_PTR(-ENOTDIR); | |
907 | return container_of(head, struct ctl_dir, header); | |
7ec66d06 EB |
908 | } |
909 | ||
910 | static struct ctl_dir *new_dir(struct ctl_table_set *set, | |
0e47c99d | 911 | const char *name, int namelen) |
7ec66d06 EB |
912 | { |
913 | struct ctl_table *table; | |
914 | struct ctl_dir *new; | |
ac13ac6f | 915 | struct ctl_node *node; |
7ec66d06 | 916 | char *new_name; |
1f87f0b5 | 917 | |
ac13ac6f EB |
918 | new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + |
919 | sizeof(struct ctl_table)*2 + namelen + 1, | |
920 | GFP_KERNEL); | |
7ec66d06 | 921 | if (!new) |
1f87f0b5 EB |
922 | return NULL; |
923 | ||
ac13ac6f EB |
924 | node = (struct ctl_node *)(new + 1); |
925 | table = (struct ctl_table *)(node + 1); | |
7ec66d06 EB |
926 | new_name = (char *)(table + 2); |
927 | memcpy(new_name, name, namelen); | |
928 | new_name[namelen] = '\0'; | |
929 | table[0].procname = new_name; | |
930 | table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; | |
ac13ac6f | 931 | init_header(&new->header, set->dir.header.root, set, node, table); |
7ec66d06 EB |
932 | |
933 | return new; | |
1f87f0b5 EB |
934 | } |
935 | ||
60f126d9 EB |
936 | /** |
937 | * get_subdir - find or create a subdir with the specified name. | |
938 | * @dir: Directory to create the subdirectory in | |
939 | * @name: The name of the subdirectory to find or create | |
940 | * @namelen: The length of name | |
941 | * | |
942 | * Takes a directory with an elevated reference count so we know that | |
943 | * if we drop the lock the directory will not go away. Upon success | |
944 | * the reference is moved from @dir to the returned subdirectory. | |
945 | * Upon error an error code is returned and the reference on @dir is | |
946 | * simply dropped. | |
947 | */ | |
0e47c99d EB |
948 | static struct ctl_dir *get_subdir(struct ctl_dir *dir, |
949 | const char *name, int namelen) | |
1f87f0b5 | 950 | { |
0e47c99d | 951 | struct ctl_table_set *set = dir->header.set; |
7ec66d06 | 952 | struct ctl_dir *subdir, *new = NULL; |
0eb97f38 | 953 | int err; |
1f87f0b5 | 954 | |
7ec66d06 | 955 | spin_lock(&sysctl_lock); |
0e47c99d | 956 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
957 | if (!IS_ERR(subdir)) |
958 | goto found; | |
959 | if (PTR_ERR(subdir) != -ENOENT) | |
960 | goto failed; | |
961 | ||
962 | spin_unlock(&sysctl_lock); | |
963 | new = new_dir(set, name, namelen); | |
964 | spin_lock(&sysctl_lock); | |
965 | subdir = ERR_PTR(-ENOMEM); | |
966 | if (!new) | |
967 | goto failed; | |
968 | ||
60f126d9 | 969 | /* Was the subdir added while we dropped the lock? */ |
0e47c99d | 970 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
971 | if (!IS_ERR(subdir)) |
972 | goto found; | |
973 | if (PTR_ERR(subdir) != -ENOENT) | |
974 | goto failed; | |
975 | ||
60f126d9 | 976 | /* Nope. Use the our freshly made directory entry. */ |
0eb97f38 EB |
977 | err = insert_header(dir, &new->header); |
978 | subdir = ERR_PTR(err); | |
979 | if (err) | |
0e47c99d | 980 | goto failed; |
7ec66d06 EB |
981 | subdir = new; |
982 | found: | |
983 | subdir->header.nreg++; | |
984 | failed: | |
a1c83681 | 985 | if (IS_ERR(subdir)) { |
87ebdc00 | 986 | pr_err("sysctl could not get directory: "); |
6980128f | 987 | sysctl_print_dir(dir); |
87ebdc00 | 988 | pr_cont("/%*.*s %ld\n", |
7ec66d06 | 989 | namelen, namelen, name, PTR_ERR(subdir)); |
1f87f0b5 | 990 | } |
7ec66d06 EB |
991 | drop_sysctl_table(&dir->header); |
992 | if (new) | |
993 | drop_sysctl_table(&new->header); | |
994 | spin_unlock(&sysctl_lock); | |
995 | return subdir; | |
1f87f0b5 EB |
996 | } |
997 | ||
0e47c99d EB |
998 | static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) |
999 | { | |
1000 | struct ctl_dir *parent; | |
1001 | const char *procname; | |
1002 | if (!dir->header.parent) | |
1003 | return &set->dir; | |
1004 | parent = xlate_dir(set, dir->header.parent); | |
1005 | if (IS_ERR(parent)) | |
1006 | return parent; | |
1007 | procname = dir->header.ctl_table[0].procname; | |
1008 | return find_subdir(parent, procname, strlen(procname)); | |
1009 | } | |
1010 | ||
1011 | static int sysctl_follow_link(struct ctl_table_header **phead, | |
13bcc6a2 | 1012 | struct ctl_table **pentry) |
0e47c99d EB |
1013 | { |
1014 | struct ctl_table_header *head; | |
1015 | struct ctl_table_root *root; | |
1016 | struct ctl_table_set *set; | |
1017 | struct ctl_table *entry; | |
1018 | struct ctl_dir *dir; | |
1019 | int ret; | |
1020 | ||
0e47c99d EB |
1021 | ret = 0; |
1022 | spin_lock(&sysctl_lock); | |
1023 | root = (*pentry)->data; | |
13bcc6a2 | 1024 | set = lookup_header_set(root); |
0e47c99d EB |
1025 | dir = xlate_dir(set, (*phead)->parent); |
1026 | if (IS_ERR(dir)) | |
1027 | ret = PTR_ERR(dir); | |
1028 | else { | |
1029 | const char *procname = (*pentry)->procname; | |
1030 | head = NULL; | |
1031 | entry = find_entry(&head, dir, procname, strlen(procname)); | |
1032 | ret = -ENOENT; | |
1033 | if (entry && use_table(head)) { | |
1034 | unuse_table(*phead); | |
1035 | *phead = head; | |
1036 | *pentry = entry; | |
1037 | ret = 0; | |
1038 | } | |
1039 | } | |
1040 | ||
1041 | spin_unlock(&sysctl_lock); | |
1042 | return ret; | |
1043 | } | |
1044 | ||
7c60c48f | 1045 | static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) |
1f87f0b5 | 1046 | { |
7c60c48f EB |
1047 | struct va_format vaf; |
1048 | va_list args; | |
1f87f0b5 | 1049 | |
7c60c48f EB |
1050 | va_start(args, fmt); |
1051 | vaf.fmt = fmt; | |
1052 | vaf.va = &args; | |
1053 | ||
87ebdc00 AM |
1054 | pr_err("sysctl table check failed: %s/%s %pV\n", |
1055 | path, table->procname, &vaf); | |
1f87f0b5 | 1056 | |
7c60c48f EB |
1057 | va_end(args); |
1058 | return -EINVAL; | |
1f87f0b5 EB |
1059 | } |
1060 | ||
7c60c48f | 1061 | static int sysctl_check_table(const char *path, struct ctl_table *table) |
1f87f0b5 | 1062 | { |
7c60c48f | 1063 | int err = 0; |
1f87f0b5 | 1064 | for (; table->procname; table++) { |
1f87f0b5 | 1065 | if (table->child) |
7c60c48f EB |
1066 | err = sysctl_err(path, table, "Not a file"); |
1067 | ||
1068 | if ((table->proc_handler == proc_dostring) || | |
1069 | (table->proc_handler == proc_dointvec) || | |
1070 | (table->proc_handler == proc_dointvec_minmax) || | |
1071 | (table->proc_handler == proc_dointvec_jiffies) || | |
1072 | (table->proc_handler == proc_dointvec_userhz_jiffies) || | |
1073 | (table->proc_handler == proc_dointvec_ms_jiffies) || | |
1074 | (table->proc_handler == proc_doulongvec_minmax) || | |
1075 | (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { | |
1076 | if (!table->data) | |
1077 | err = sysctl_err(path, table, "No data"); | |
1078 | if (!table->maxlen) | |
1079 | err = sysctl_err(path, table, "No maxlen"); | |
1080 | } | |
1081 | if (!table->proc_handler) | |
1082 | err = sysctl_err(path, table, "No proc_handler"); | |
1083 | ||
1084 | if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) | |
1085 | err = sysctl_err(path, table, "bogus .mode 0%o", | |
1086 | table->mode); | |
1f87f0b5 | 1087 | } |
7c60c48f | 1088 | return err; |
1f87f0b5 | 1089 | } |
1f87f0b5 | 1090 | |
0e47c99d EB |
1091 | static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, |
1092 | struct ctl_table_root *link_root) | |
1093 | { | |
1094 | struct ctl_table *link_table, *entry, *link; | |
1095 | struct ctl_table_header *links; | |
ac13ac6f | 1096 | struct ctl_node *node; |
0e47c99d EB |
1097 | char *link_name; |
1098 | int nr_entries, name_bytes; | |
1099 | ||
1100 | name_bytes = 0; | |
1101 | nr_entries = 0; | |
1102 | for (entry = table; entry->procname; entry++) { | |
1103 | nr_entries++; | |
1104 | name_bytes += strlen(entry->procname) + 1; | |
1105 | } | |
1106 | ||
1107 | links = kzalloc(sizeof(struct ctl_table_header) + | |
ac13ac6f | 1108 | sizeof(struct ctl_node)*nr_entries + |
0e47c99d EB |
1109 | sizeof(struct ctl_table)*(nr_entries + 1) + |
1110 | name_bytes, | |
1111 | GFP_KERNEL); | |
1112 | ||
1113 | if (!links) | |
1114 | return NULL; | |
1115 | ||
ac13ac6f EB |
1116 | node = (struct ctl_node *)(links + 1); |
1117 | link_table = (struct ctl_table *)(node + nr_entries); | |
0e47c99d EB |
1118 | link_name = (char *)&link_table[nr_entries + 1]; |
1119 | ||
1120 | for (link = link_table, entry = table; entry->procname; link++, entry++) { | |
1121 | int len = strlen(entry->procname) + 1; | |
1122 | memcpy(link_name, entry->procname, len); | |
1123 | link->procname = link_name; | |
1124 | link->mode = S_IFLNK|S_IRWXUGO; | |
1125 | link->data = link_root; | |
1126 | link_name += len; | |
1127 | } | |
ac13ac6f | 1128 | init_header(links, dir->header.root, dir->header.set, node, link_table); |
0e47c99d EB |
1129 | links->nreg = nr_entries; |
1130 | ||
1131 | return links; | |
1132 | } | |
1133 | ||
1134 | static bool get_links(struct ctl_dir *dir, | |
1135 | struct ctl_table *table, struct ctl_table_root *link_root) | |
1136 | { | |
1137 | struct ctl_table_header *head; | |
1138 | struct ctl_table *entry, *link; | |
1139 | ||
1140 | /* Are there links available for every entry in table? */ | |
1141 | for (entry = table; entry->procname; entry++) { | |
1142 | const char *procname = entry->procname; | |
1143 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1144 | if (!link) | |
1145 | return false; | |
1146 | if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) | |
1147 | continue; | |
1148 | if (S_ISLNK(link->mode) && (link->data == link_root)) | |
1149 | continue; | |
1150 | return false; | |
1151 | } | |
1152 | ||
1153 | /* The checks passed. Increase the registration count on the links */ | |
1154 | for (entry = table; entry->procname; entry++) { | |
1155 | const char *procname = entry->procname; | |
1156 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1157 | head->nreg++; | |
1158 | } | |
1159 | return true; | |
1160 | } | |
1161 | ||
1162 | static int insert_links(struct ctl_table_header *head) | |
1163 | { | |
1164 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1165 | struct ctl_dir *core_parent = NULL; | |
1166 | struct ctl_table_header *links; | |
1167 | int err; | |
1168 | ||
1169 | if (head->set == root_set) | |
1170 | return 0; | |
1171 | ||
1172 | core_parent = xlate_dir(root_set, head->parent); | |
1173 | if (IS_ERR(core_parent)) | |
1174 | return 0; | |
1175 | ||
1176 | if (get_links(core_parent, head->ctl_table, head->root)) | |
1177 | return 0; | |
1178 | ||
1179 | core_parent->header.nreg++; | |
1180 | spin_unlock(&sysctl_lock); | |
1181 | ||
1182 | links = new_links(core_parent, head->ctl_table, head->root); | |
1183 | ||
1184 | spin_lock(&sysctl_lock); | |
1185 | err = -ENOMEM; | |
1186 | if (!links) | |
1187 | goto out; | |
1188 | ||
1189 | err = 0; | |
1190 | if (get_links(core_parent, head->ctl_table, head->root)) { | |
1191 | kfree(links); | |
1192 | goto out; | |
1193 | } | |
1194 | ||
1195 | err = insert_header(core_parent, links); | |
1196 | if (err) | |
1197 | kfree(links); | |
1198 | out: | |
1199 | drop_sysctl_table(&core_parent->header); | |
1200 | return err; | |
1201 | } | |
1202 | ||
1f87f0b5 | 1203 | /** |
f728019b | 1204 | * __register_sysctl_table - register a leaf sysctl table |
60a47a2e | 1205 | * @set: Sysctl tree to register on |
1f87f0b5 EB |
1206 | * @path: The path to the directory the sysctl table is in. |
1207 | * @table: the top-level table structure | |
1208 | * | |
1209 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1210 | * array. A completely 0 filled entry terminates the table. | |
1211 | * | |
1212 | * The members of the &struct ctl_table structure are used as follows: | |
1213 | * | |
1214 | * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not | |
1215 | * enter a sysctl file | |
1216 | * | |
1217 | * data - a pointer to data for use by proc_handler | |
1218 | * | |
1219 | * maxlen - the maximum size in bytes of the data | |
1220 | * | |
f728019b | 1221 | * mode - the file permissions for the /proc/sys file |
1f87f0b5 | 1222 | * |
f728019b | 1223 | * child - must be %NULL. |
1f87f0b5 EB |
1224 | * |
1225 | * proc_handler - the text handler routine (described below) | |
1226 | * | |
1f87f0b5 EB |
1227 | * extra1, extra2 - extra pointers usable by the proc handler routines |
1228 | * | |
1229 | * Leaf nodes in the sysctl tree will be represented by a single file | |
1230 | * under /proc; non-leaf nodes will be represented by directories. | |
1231 | * | |
f728019b EB |
1232 | * There must be a proc_handler routine for any terminal nodes. |
1233 | * Several default handlers are available to cover common cases - | |
1f87f0b5 EB |
1234 | * |
1235 | * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), | |
1236 | * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), | |
1237 | * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() | |
1238 | * | |
1239 | * It is the handler's job to read the input buffer from user memory | |
1240 | * and process it. The handler should return 0 on success. | |
1241 | * | |
1242 | * This routine returns %NULL on a failure to register, and a pointer | |
1243 | * to the table header on success. | |
1244 | */ | |
6e9d5164 | 1245 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 1246 | struct ctl_table_set *set, |
6e9d5164 | 1247 | const char *path, struct ctl_table *table) |
1f87f0b5 | 1248 | { |
60a47a2e | 1249 | struct ctl_table_root *root = set->dir.header.root; |
1f87f0b5 | 1250 | struct ctl_table_header *header; |
6e9d5164 | 1251 | const char *name, *nextname; |
7ec66d06 | 1252 | struct ctl_dir *dir; |
ac13ac6f EB |
1253 | struct ctl_table *entry; |
1254 | struct ctl_node *node; | |
1255 | int nr_entries = 0; | |
1256 | ||
1257 | for (entry = table; entry->procname; entry++) | |
1258 | nr_entries++; | |
1f87f0b5 | 1259 | |
ac13ac6f EB |
1260 | header = kzalloc(sizeof(struct ctl_table_header) + |
1261 | sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); | |
1f87f0b5 EB |
1262 | if (!header) |
1263 | return NULL; | |
1264 | ||
ac13ac6f EB |
1265 | node = (struct ctl_node *)(header + 1); |
1266 | init_header(header, root, set, node, table); | |
7ec66d06 EB |
1267 | if (sysctl_check_table(path, table)) |
1268 | goto fail; | |
1269 | ||
1270 | spin_lock(&sysctl_lock); | |
0e47c99d | 1271 | dir = &set->dir; |
60f126d9 | 1272 | /* Reference moved down the diretory tree get_subdir */ |
7ec66d06 EB |
1273 | dir->header.nreg++; |
1274 | spin_unlock(&sysctl_lock); | |
1f87f0b5 | 1275 | |
7ec66d06 | 1276 | /* Find the directory for the ctl_table */ |
6e9d5164 EB |
1277 | for (name = path; name; name = nextname) { |
1278 | int namelen; | |
1279 | nextname = strchr(name, '/'); | |
1280 | if (nextname) { | |
1281 | namelen = nextname - name; | |
1282 | nextname++; | |
1283 | } else { | |
1284 | namelen = strlen(name); | |
1285 | } | |
1286 | if (namelen == 0) | |
1287 | continue; | |
1f87f0b5 | 1288 | |
0e47c99d | 1289 | dir = get_subdir(dir, name, namelen); |
7ec66d06 EB |
1290 | if (IS_ERR(dir)) |
1291 | goto fail; | |
1f87f0b5 | 1292 | } |
0e47c99d | 1293 | |
1f87f0b5 | 1294 | spin_lock(&sysctl_lock); |
0e47c99d | 1295 | if (insert_header(dir, header)) |
7ec66d06 | 1296 | goto fail_put_dir_locked; |
0e47c99d | 1297 | |
7ec66d06 | 1298 | drop_sysctl_table(&dir->header); |
1f87f0b5 EB |
1299 | spin_unlock(&sysctl_lock); |
1300 | ||
1301 | return header; | |
0e47c99d | 1302 | |
7ec66d06 EB |
1303 | fail_put_dir_locked: |
1304 | drop_sysctl_table(&dir->header); | |
7c60c48f EB |
1305 | spin_unlock(&sysctl_lock); |
1306 | fail: | |
1307 | kfree(header); | |
1308 | dump_stack(); | |
1309 | return NULL; | |
1f87f0b5 EB |
1310 | } |
1311 | ||
fea478d4 EB |
1312 | /** |
1313 | * register_sysctl - register a sysctl table | |
1314 | * @path: The path to the directory the sysctl table is in. | |
1315 | * @table: the table structure | |
1316 | * | |
1317 | * Register a sysctl table. @table should be a filled in ctl_table | |
1318 | * array. A completely 0 filled entry terminates the table. | |
1319 | * | |
1320 | * See __register_sysctl_table for more details. | |
1321 | */ | |
1322 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) | |
1323 | { | |
1324 | return __register_sysctl_table(&sysctl_table_root.default_set, | |
1325 | path, table); | |
1326 | } | |
1327 | EXPORT_SYMBOL(register_sysctl); | |
1328 | ||
6e9d5164 EB |
1329 | static char *append_path(const char *path, char *pos, const char *name) |
1330 | { | |
1331 | int namelen; | |
1332 | namelen = strlen(name); | |
1333 | if (((pos - path) + namelen + 2) >= PATH_MAX) | |
1334 | return NULL; | |
1335 | memcpy(pos, name, namelen); | |
1336 | pos[namelen] = '/'; | |
1337 | pos[namelen + 1] = '\0'; | |
1338 | pos += namelen + 1; | |
1339 | return pos; | |
1340 | } | |
1341 | ||
f728019b EB |
1342 | static int count_subheaders(struct ctl_table *table) |
1343 | { | |
1344 | int has_files = 0; | |
1345 | int nr_subheaders = 0; | |
1346 | struct ctl_table *entry; | |
1347 | ||
1348 | /* special case: no directory and empty directory */ | |
1349 | if (!table || !table->procname) | |
1350 | return 1; | |
1351 | ||
1352 | for (entry = table; entry->procname; entry++) { | |
1353 | if (entry->child) | |
1354 | nr_subheaders += count_subheaders(entry->child); | |
1355 | else | |
1356 | has_files = 1; | |
1357 | } | |
1358 | return nr_subheaders + has_files; | |
1359 | } | |
1360 | ||
1361 | static int register_leaf_sysctl_tables(const char *path, char *pos, | |
60a47a2e | 1362 | struct ctl_table_header ***subheader, struct ctl_table_set *set, |
f728019b EB |
1363 | struct ctl_table *table) |
1364 | { | |
1365 | struct ctl_table *ctl_table_arg = NULL; | |
1366 | struct ctl_table *entry, *files; | |
1367 | int nr_files = 0; | |
1368 | int nr_dirs = 0; | |
1369 | int err = -ENOMEM; | |
1370 | ||
1371 | for (entry = table; entry->procname; entry++) { | |
1372 | if (entry->child) | |
1373 | nr_dirs++; | |
1374 | else | |
1375 | nr_files++; | |
1376 | } | |
1377 | ||
1378 | files = table; | |
1379 | /* If there are mixed files and directories we need a new table */ | |
1380 | if (nr_dirs && nr_files) { | |
1381 | struct ctl_table *new; | |
1382 | files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), | |
1383 | GFP_KERNEL); | |
1384 | if (!files) | |
1385 | goto out; | |
1386 | ||
1387 | ctl_table_arg = files; | |
1388 | for (new = files, entry = table; entry->procname; entry++) { | |
1389 | if (entry->child) | |
1390 | continue; | |
1391 | *new = *entry; | |
1392 | new++; | |
1393 | } | |
1394 | } | |
1395 | ||
1396 | /* Register everything except a directory full of subdirectories */ | |
1397 | if (nr_files || !nr_dirs) { | |
1398 | struct ctl_table_header *header; | |
60a47a2e | 1399 | header = __register_sysctl_table(set, path, files); |
f728019b EB |
1400 | if (!header) { |
1401 | kfree(ctl_table_arg); | |
1402 | goto out; | |
1403 | } | |
1404 | ||
1405 | /* Remember if we need to free the file table */ | |
1406 | header->ctl_table_arg = ctl_table_arg; | |
1407 | **subheader = header; | |
1408 | (*subheader)++; | |
1409 | } | |
1410 | ||
1411 | /* Recurse into the subdirectories. */ | |
1412 | for (entry = table; entry->procname; entry++) { | |
1413 | char *child_pos; | |
1414 | ||
1415 | if (!entry->child) | |
1416 | continue; | |
1417 | ||
1418 | err = -ENAMETOOLONG; | |
1419 | child_pos = append_path(path, pos, entry->procname); | |
1420 | if (!child_pos) | |
1421 | goto out; | |
1422 | ||
1423 | err = register_leaf_sysctl_tables(path, child_pos, subheader, | |
60a47a2e | 1424 | set, entry->child); |
f728019b EB |
1425 | pos[0] = '\0'; |
1426 | if (err) | |
1427 | goto out; | |
1428 | } | |
1429 | err = 0; | |
1430 | out: | |
1431 | /* On failure our caller will unregister all registered subheaders */ | |
1432 | return err; | |
1433 | } | |
1434 | ||
6e9d5164 EB |
1435 | /** |
1436 | * __register_sysctl_paths - register a sysctl table hierarchy | |
60a47a2e | 1437 | * @set: Sysctl tree to register on |
6e9d5164 EB |
1438 | * @path: The path to the directory the sysctl table is in. |
1439 | * @table: the top-level table structure | |
1440 | * | |
1441 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1442 | * array. A completely 0 filled entry terminates the table. | |
1443 | * | |
1444 | * See __register_sysctl_table for more details. | |
1445 | */ | |
1446 | struct ctl_table_header *__register_sysctl_paths( | |
60a47a2e | 1447 | struct ctl_table_set *set, |
6e9d5164 EB |
1448 | const struct ctl_path *path, struct ctl_table *table) |
1449 | { | |
ec6a5266 | 1450 | struct ctl_table *ctl_table_arg = table; |
f728019b EB |
1451 | int nr_subheaders = count_subheaders(table); |
1452 | struct ctl_table_header *header = NULL, **subheaders, **subheader; | |
6e9d5164 EB |
1453 | const struct ctl_path *component; |
1454 | char *new_path, *pos; | |
1455 | ||
1456 | pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); | |
1457 | if (!new_path) | |
1458 | return NULL; | |
1459 | ||
1460 | pos[0] = '\0'; | |
1461 | for (component = path; component->procname; component++) { | |
1462 | pos = append_path(new_path, pos, component->procname); | |
1463 | if (!pos) | |
1464 | goto out; | |
1465 | } | |
ec6a5266 EB |
1466 | while (table->procname && table->child && !table[1].procname) { |
1467 | pos = append_path(new_path, pos, table->procname); | |
1468 | if (!pos) | |
1469 | goto out; | |
1470 | table = table->child; | |
1471 | } | |
f728019b | 1472 | if (nr_subheaders == 1) { |
60a47a2e | 1473 | header = __register_sysctl_table(set, new_path, table); |
f728019b EB |
1474 | if (header) |
1475 | header->ctl_table_arg = ctl_table_arg; | |
1476 | } else { | |
1477 | header = kzalloc(sizeof(*header) + | |
1478 | sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); | |
1479 | if (!header) | |
1480 | goto out; | |
1481 | ||
1482 | subheaders = (struct ctl_table_header **) (header + 1); | |
1483 | subheader = subheaders; | |
ec6a5266 | 1484 | header->ctl_table_arg = ctl_table_arg; |
f728019b EB |
1485 | |
1486 | if (register_leaf_sysctl_tables(new_path, pos, &subheader, | |
60a47a2e | 1487 | set, table)) |
f728019b EB |
1488 | goto err_register_leaves; |
1489 | } | |
1490 | ||
6e9d5164 EB |
1491 | out: |
1492 | kfree(new_path); | |
1493 | return header; | |
f728019b EB |
1494 | |
1495 | err_register_leaves: | |
1496 | while (subheader > subheaders) { | |
1497 | struct ctl_table_header *subh = *(--subheader); | |
1498 | struct ctl_table *table = subh->ctl_table_arg; | |
1499 | unregister_sysctl_table(subh); | |
1500 | kfree(table); | |
1501 | } | |
1502 | kfree(header); | |
1503 | header = NULL; | |
1504 | goto out; | |
6e9d5164 EB |
1505 | } |
1506 | ||
1f87f0b5 EB |
1507 | /** |
1508 | * register_sysctl_table_path - register a sysctl table hierarchy | |
1509 | * @path: The path to the directory the sysctl table is in. | |
1510 | * @table: the top-level table structure | |
1511 | * | |
1512 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1513 | * array. A completely 0 filled entry terminates the table. | |
1514 | * | |
1515 | * See __register_sysctl_paths for more details. | |
1516 | */ | |
1517 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, | |
1518 | struct ctl_table *table) | |
1519 | { | |
60a47a2e | 1520 | return __register_sysctl_paths(&sysctl_table_root.default_set, |
1f87f0b5 EB |
1521 | path, table); |
1522 | } | |
1523 | EXPORT_SYMBOL(register_sysctl_paths); | |
1524 | ||
1525 | /** | |
1526 | * register_sysctl_table - register a sysctl table hierarchy | |
1527 | * @table: the top-level table structure | |
1528 | * | |
1529 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1530 | * array. A completely 0 filled entry terminates the table. | |
1531 | * | |
1532 | * See register_sysctl_paths for more details. | |
1533 | */ | |
1534 | struct ctl_table_header *register_sysctl_table(struct ctl_table *table) | |
1535 | { | |
1536 | static const struct ctl_path null_path[] = { {} }; | |
1537 | ||
1538 | return register_sysctl_paths(null_path, table); | |
1539 | } | |
1540 | EXPORT_SYMBOL(register_sysctl_table); | |
1541 | ||
0e47c99d EB |
1542 | static void put_links(struct ctl_table_header *header) |
1543 | { | |
1544 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1545 | struct ctl_table_root *root = header->root; | |
1546 | struct ctl_dir *parent = header->parent; | |
1547 | struct ctl_dir *core_parent; | |
1548 | struct ctl_table *entry; | |
1549 | ||
1550 | if (header->set == root_set) | |
1551 | return; | |
1552 | ||
1553 | core_parent = xlate_dir(root_set, parent); | |
1554 | if (IS_ERR(core_parent)) | |
1555 | return; | |
1556 | ||
1557 | for (entry = header->ctl_table; entry->procname; entry++) { | |
1558 | struct ctl_table_header *link_head; | |
1559 | struct ctl_table *link; | |
1560 | const char *name = entry->procname; | |
1561 | ||
1562 | link = find_entry(&link_head, core_parent, name, strlen(name)); | |
1563 | if (link && | |
1564 | ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || | |
1565 | (S_ISLNK(link->mode) && (link->data == root)))) { | |
1566 | drop_sysctl_table(link_head); | |
1567 | } | |
1568 | else { | |
87ebdc00 | 1569 | pr_err("sysctl link missing during unregister: "); |
0e47c99d | 1570 | sysctl_print_dir(parent); |
87ebdc00 | 1571 | pr_cont("/%s\n", name); |
0e47c99d EB |
1572 | } |
1573 | } | |
1574 | } | |
1575 | ||
938aaa4f EB |
1576 | static void drop_sysctl_table(struct ctl_table_header *header) |
1577 | { | |
7ec66d06 EB |
1578 | struct ctl_dir *parent = header->parent; |
1579 | ||
938aaa4f EB |
1580 | if (--header->nreg) |
1581 | return; | |
1582 | ||
0e47c99d | 1583 | put_links(header); |
938aaa4f | 1584 | start_unregistering(header); |
938aaa4f EB |
1585 | if (!--header->count) |
1586 | kfree_rcu(header, rcu); | |
7ec66d06 EB |
1587 | |
1588 | if (parent) | |
1589 | drop_sysctl_table(&parent->header); | |
938aaa4f EB |
1590 | } |
1591 | ||
1f87f0b5 EB |
1592 | /** |
1593 | * unregister_sysctl_table - unregister a sysctl table hierarchy | |
1594 | * @header: the header returned from register_sysctl_table | |
1595 | * | |
1596 | * Unregisters the sysctl table and all children. proc entries may not | |
1597 | * actually be removed until they are no longer used by anyone. | |
1598 | */ | |
1599 | void unregister_sysctl_table(struct ctl_table_header * header) | |
1600 | { | |
f728019b | 1601 | int nr_subheaders; |
1f87f0b5 EB |
1602 | might_sleep(); |
1603 | ||
1604 | if (header == NULL) | |
1605 | return; | |
1606 | ||
f728019b EB |
1607 | nr_subheaders = count_subheaders(header->ctl_table_arg); |
1608 | if (unlikely(nr_subheaders > 1)) { | |
1609 | struct ctl_table_header **subheaders; | |
1610 | int i; | |
1611 | ||
1612 | subheaders = (struct ctl_table_header **)(header + 1); | |
1613 | for (i = nr_subheaders -1; i >= 0; i--) { | |
1614 | struct ctl_table_header *subh = subheaders[i]; | |
1615 | struct ctl_table *table = subh->ctl_table_arg; | |
1616 | unregister_sysctl_table(subh); | |
1617 | kfree(table); | |
1618 | } | |
1619 | kfree(header); | |
1620 | return; | |
1621 | } | |
1622 | ||
1f87f0b5 | 1623 | spin_lock(&sysctl_lock); |
938aaa4f | 1624 | drop_sysctl_table(header); |
1f87f0b5 EB |
1625 | spin_unlock(&sysctl_lock); |
1626 | } | |
1627 | EXPORT_SYMBOL(unregister_sysctl_table); | |
1628 | ||
0e47c99d | 1629 | void setup_sysctl_set(struct ctl_table_set *set, |
9eb47c26 | 1630 | struct ctl_table_root *root, |
1f87f0b5 EB |
1631 | int (*is_seen)(struct ctl_table_set *)) |
1632 | { | |
1347440d | 1633 | memset(set, 0, sizeof(*set)); |
0e47c99d | 1634 | set->is_seen = is_seen; |
ac13ac6f | 1635 | init_header(&set->dir.header, root, set, NULL, root_table); |
1f87f0b5 EB |
1636 | } |
1637 | ||
97324cd8 EB |
1638 | void retire_sysctl_set(struct ctl_table_set *set) |
1639 | { | |
ac13ac6f | 1640 | WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); |
97324cd8 | 1641 | } |
1f87f0b5 | 1642 | |
1e0edd3f | 1643 | int __init proc_sys_init(void) |
77b14db5 | 1644 | { |
e1675231 AD |
1645 | struct proc_dir_entry *proc_sys_root; |
1646 | ||
77b14db5 | 1647 | proc_sys_root = proc_mkdir("sys", NULL); |
9043476f AV |
1648 | proc_sys_root->proc_iops = &proc_sys_dir_operations; |
1649 | proc_sys_root->proc_fops = &proc_sys_dir_file_operations; | |
77b14db5 | 1650 | proc_sys_root->nlink = 0; |
de4e83bd EB |
1651 | |
1652 | return sysctl_init(); | |
77b14db5 | 1653 | } |