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