Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
77b14db5 EB |
2 | /* |
3 | * /proc/sys support | |
4 | */ | |
1e0edd3f | 5 | #include <linux/init.h> |
77b14db5 | 6 | #include <linux/sysctl.h> |
f1ecf068 | 7 | #include <linux/poll.h> |
77b14db5 | 8 | #include <linux/proc_fs.h> |
87ebdc00 | 9 | #include <linux/printk.h> |
77b14db5 | 10 | #include <linux/security.h> |
40401530 | 11 | #include <linux/sched.h> |
5b825c3a | 12 | #include <linux/cred.h> |
34286d66 | 13 | #include <linux/namei.h> |
40401530 | 14 | #include <linux/mm.h> |
1f87f0b5 | 15 | #include <linux/module.h> |
77b14db5 EB |
16 | #include "internal.h" |
17 | ||
d72f71eb | 18 | static const struct dentry_operations proc_sys_dentry_operations; |
77b14db5 | 19 | static const struct file_operations proc_sys_file_operations; |
03a44825 | 20 | static const struct inode_operations proc_sys_inode_operations; |
9043476f AV |
21 | static const struct file_operations proc_sys_dir_file_operations; |
22 | static const struct inode_operations proc_sys_dir_operations; | |
77b14db5 | 23 | |
f9bd6733 EB |
24 | /* Support for permanently empty directories */ |
25 | ||
26 | struct ctl_table sysctl_mount_point[] = { | |
27 | { } | |
28 | }; | |
29 | ||
30 | static bool is_empty_dir(struct ctl_table_header *head) | |
31 | { | |
32 | return head->ctl_table[0].child == sysctl_mount_point; | |
33 | } | |
34 | ||
35 | static void set_empty_dir(struct ctl_dir *dir) | |
36 | { | |
37 | dir->header.ctl_table[0].child = sysctl_mount_point; | |
38 | } | |
39 | ||
40 | static void clear_empty_dir(struct ctl_dir *dir) | |
41 | ||
42 | { | |
43 | dir->header.ctl_table[0].child = NULL; | |
44 | } | |
45 | ||
f1ecf068 LDM |
46 | void proc_sys_poll_notify(struct ctl_table_poll *poll) |
47 | { | |
48 | if (!poll) | |
49 | return; | |
50 | ||
51 | atomic_inc(&poll->event); | |
52 | wake_up_interruptible(&poll->wait); | |
53 | } | |
54 | ||
a194558e EB |
55 | static struct ctl_table root_table[] = { |
56 | { | |
57 | .procname = "", | |
7ec66d06 | 58 | .mode = S_IFDIR|S_IRUGO|S_IXUGO, |
a194558e EB |
59 | }, |
60 | { } | |
61 | }; | |
0e47c99d | 62 | static struct ctl_table_root sysctl_table_root = { |
0e47c99d | 63 | .default_set.dir.header = { |
7ec66d06 EB |
64 | {{.count = 1, |
65 | .nreg = 1, | |
ac13ac6f | 66 | .ctl_table = root_table }}, |
0e47c99d | 67 | .ctl_table_arg = root_table, |
7ec66d06 EB |
68 | .root = &sysctl_table_root, |
69 | .set = &sysctl_table_root.default_set, | |
70 | }, | |
1f87f0b5 | 71 | }; |
1f87f0b5 EB |
72 | |
73 | static DEFINE_SPINLOCK(sysctl_lock); | |
74 | ||
7ec66d06 | 75 | static void drop_sysctl_table(struct ctl_table_header *header); |
0e47c99d | 76 | static int sysctl_follow_link(struct ctl_table_header **phead, |
13bcc6a2 | 77 | struct ctl_table **pentry); |
0e47c99d EB |
78 | static int insert_links(struct ctl_table_header *head); |
79 | static void put_links(struct ctl_table_header *header); | |
7ec66d06 | 80 | |
6980128f EB |
81 | static void sysctl_print_dir(struct ctl_dir *dir) |
82 | { | |
83 | if (dir->header.parent) | |
84 | sysctl_print_dir(dir->header.parent); | |
87ebdc00 | 85 | pr_cont("%s/", dir->header.ctl_table[0].procname); |
6980128f EB |
86 | } |
87 | ||
076c3eed EB |
88 | static int namecmp(const char *name1, int len1, const char *name2, int len2) |
89 | { | |
90 | int minlen; | |
91 | int cmp; | |
92 | ||
93 | minlen = len1; | |
94 | if (minlen > len2) | |
95 | minlen = len2; | |
96 | ||
97 | cmp = memcmp(name1, name2, minlen); | |
98 | if (cmp == 0) | |
99 | cmp = len1 - len2; | |
100 | return cmp; | |
101 | } | |
102 | ||
60f126d9 | 103 | /* Called under sysctl_lock */ |
076c3eed | 104 | static struct ctl_table *find_entry(struct ctl_table_header **phead, |
0e47c99d | 105 | struct ctl_dir *dir, const char *name, int namelen) |
076c3eed EB |
106 | { |
107 | struct ctl_table_header *head; | |
108 | struct ctl_table *entry; | |
ac13ac6f | 109 | struct rb_node *node = dir->root.rb_node; |
076c3eed | 110 | |
ac13ac6f EB |
111 | while (node) |
112 | { | |
113 | struct ctl_node *ctl_node; | |
114 | const char *procname; | |
115 | int cmp; | |
116 | ||
117 | ctl_node = rb_entry(node, struct ctl_node, node); | |
118 | head = ctl_node->header; | |
119 | entry = &head->ctl_table[ctl_node - head->node]; | |
120 | procname = entry->procname; | |
121 | ||
122 | cmp = namecmp(name, namelen, procname, strlen(procname)); | |
123 | if (cmp < 0) | |
124 | node = node->rb_left; | |
125 | else if (cmp > 0) | |
126 | node = node->rb_right; | |
127 | else { | |
128 | *phead = head; | |
129 | return entry; | |
076c3eed EB |
130 | } |
131 | } | |
132 | return NULL; | |
133 | } | |
134 | ||
ac13ac6f EB |
135 | static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) |
136 | { | |
137 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
138 | struct rb_node **p = &head->parent->root.rb_node; | |
139 | struct rb_node *parent = NULL; | |
140 | const char *name = entry->procname; | |
141 | int namelen = strlen(name); | |
142 | ||
143 | while (*p) { | |
144 | struct ctl_table_header *parent_head; | |
145 | struct ctl_table *parent_entry; | |
146 | struct ctl_node *parent_node; | |
147 | const char *parent_name; | |
148 | int cmp; | |
149 | ||
150 | parent = *p; | |
151 | parent_node = rb_entry(parent, struct ctl_node, node); | |
152 | parent_head = parent_node->header; | |
153 | parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; | |
154 | parent_name = parent_entry->procname; | |
155 | ||
156 | cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); | |
157 | if (cmp < 0) | |
158 | p = &(*p)->rb_left; | |
159 | else if (cmp > 0) | |
160 | p = &(*p)->rb_right; | |
161 | else { | |
87ebdc00 | 162 | pr_err("sysctl duplicate entry: "); |
ac13ac6f | 163 | sysctl_print_dir(head->parent); |
87ebdc00 | 164 | pr_cont("/%s\n", entry->procname); |
ac13ac6f EB |
165 | return -EEXIST; |
166 | } | |
167 | } | |
168 | ||
169 | rb_link_node(node, parent, p); | |
ea5272f5 | 170 | rb_insert_color(node, &head->parent->root); |
ac13ac6f EB |
171 | return 0; |
172 | } | |
173 | ||
174 | static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) | |
175 | { | |
176 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
177 | ||
178 | rb_erase(node, &head->parent->root); | |
179 | } | |
180 | ||
e0d04529 EB |
181 | static void init_header(struct ctl_table_header *head, |
182 | struct ctl_table_root *root, struct ctl_table_set *set, | |
ac13ac6f | 183 | struct ctl_node *node, struct ctl_table *table) |
e0d04529 | 184 | { |
7ec66d06 | 185 | head->ctl_table = table; |
e0d04529 | 186 | head->ctl_table_arg = table; |
e0d04529 EB |
187 | head->used = 0; |
188 | head->count = 1; | |
189 | head->nreg = 1; | |
190 | head->unregistering = NULL; | |
191 | head->root = root; | |
192 | head->set = set; | |
193 | head->parent = NULL; | |
ac13ac6f | 194 | head->node = node; |
2fd1d2c4 | 195 | INIT_HLIST_HEAD(&head->inodes); |
ac13ac6f EB |
196 | if (node) { |
197 | struct ctl_table *entry; | |
4c199a93 | 198 | for (entry = table; entry->procname; entry++, node++) |
ac13ac6f | 199 | node->header = head; |
ac13ac6f | 200 | } |
e0d04529 EB |
201 | } |
202 | ||
8425d6aa EB |
203 | static void erase_header(struct ctl_table_header *head) |
204 | { | |
ac13ac6f EB |
205 | struct ctl_table *entry; |
206 | for (entry = head->ctl_table; entry->procname; entry++) | |
207 | erase_entry(head, entry); | |
8425d6aa EB |
208 | } |
209 | ||
0e47c99d | 210 | static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) |
8425d6aa | 211 | { |
ac13ac6f | 212 | struct ctl_table *entry; |
0e47c99d EB |
213 | int err; |
214 | ||
f9bd6733 EB |
215 | /* Is this a permanently empty directory? */ |
216 | if (is_empty_dir(&dir->header)) | |
217 | return -EROFS; | |
218 | ||
219 | /* Am I creating a permanently empty directory? */ | |
220 | if (header->ctl_table == sysctl_mount_point) { | |
221 | if (!RB_EMPTY_ROOT(&dir->root)) | |
222 | return -EINVAL; | |
223 | set_empty_dir(dir); | |
224 | } | |
225 | ||
0e47c99d | 226 | dir->header.nreg++; |
7ec66d06 | 227 | header->parent = dir; |
0e47c99d EB |
228 | err = insert_links(header); |
229 | if (err) | |
230 | goto fail_links; | |
ac13ac6f EB |
231 | for (entry = header->ctl_table; entry->procname; entry++) { |
232 | err = insert_entry(header, entry); | |
233 | if (err) | |
234 | goto fail; | |
235 | } | |
0e47c99d | 236 | return 0; |
ac13ac6f EB |
237 | fail: |
238 | erase_header(header); | |
239 | put_links(header); | |
0e47c99d | 240 | fail_links: |
f9bd6733 EB |
241 | if (header->ctl_table == sysctl_mount_point) |
242 | clear_empty_dir(dir); | |
0e47c99d EB |
243 | header->parent = NULL; |
244 | drop_sysctl_table(&dir->header); | |
245 | return err; | |
8425d6aa EB |
246 | } |
247 | ||
1f87f0b5 EB |
248 | /* called under sysctl_lock */ |
249 | static int use_table(struct ctl_table_header *p) | |
250 | { | |
251 | if (unlikely(p->unregistering)) | |
252 | return 0; | |
253 | p->used++; | |
254 | return 1; | |
255 | } | |
256 | ||
257 | /* called under sysctl_lock */ | |
258 | static void unuse_table(struct ctl_table_header *p) | |
259 | { | |
260 | if (!--p->used) | |
261 | if (unlikely(p->unregistering)) | |
262 | complete(p->unregistering); | |
263 | } | |
264 | ||
d6cffbbe KK |
265 | static void proc_sys_prune_dcache(struct ctl_table_header *head) |
266 | { | |
2fd1d2c4 | 267 | struct inode *inode; |
d6cffbbe | 268 | struct proc_inode *ei; |
2fd1d2c4 EB |
269 | struct hlist_node *node; |
270 | struct super_block *sb; | |
d6cffbbe | 271 | |
ace0c791 | 272 | rcu_read_lock(); |
2fd1d2c4 EB |
273 | for (;;) { |
274 | node = hlist_first_rcu(&head->inodes); | |
275 | if (!node) | |
276 | break; | |
277 | ei = hlist_entry(node, struct proc_inode, sysctl_inodes); | |
278 | spin_lock(&sysctl_lock); | |
279 | hlist_del_init_rcu(&ei->sysctl_inodes); | |
280 | spin_unlock(&sysctl_lock); | |
281 | ||
282 | inode = &ei->vfs_inode; | |
283 | sb = inode->i_sb; | |
284 | if (!atomic_inc_not_zero(&sb->s_active)) | |
285 | continue; | |
286 | inode = igrab(inode); | |
287 | rcu_read_unlock(); | |
288 | if (unlikely(!inode)) { | |
289 | deactivate_super(sb); | |
ace0c791 | 290 | rcu_read_lock(); |
2fd1d2c4 | 291 | continue; |
d6cffbbe | 292 | } |
2fd1d2c4 EB |
293 | |
294 | d_prune_aliases(inode); | |
295 | iput(inode); | |
296 | deactivate_super(sb); | |
297 | ||
298 | rcu_read_lock(); | |
d6cffbbe | 299 | } |
ace0c791 | 300 | rcu_read_unlock(); |
d6cffbbe KK |
301 | } |
302 | ||
1f87f0b5 EB |
303 | /* called under sysctl_lock, will reacquire if has to wait */ |
304 | static void start_unregistering(struct ctl_table_header *p) | |
305 | { | |
306 | /* | |
307 | * if p->used is 0, nobody will ever touch that entry again; | |
308 | * we'll eliminate all paths to it before dropping sysctl_lock | |
309 | */ | |
310 | if (unlikely(p->used)) { | |
311 | struct completion wait; | |
312 | init_completion(&wait); | |
313 | p->unregistering = &wait; | |
314 | spin_unlock(&sysctl_lock); | |
315 | wait_for_completion(&wait); | |
1f87f0b5 EB |
316 | } else { |
317 | /* anything non-NULL; we'll never dereference it */ | |
318 | p->unregistering = ERR_PTR(-EINVAL); | |
ace0c791 | 319 | spin_unlock(&sysctl_lock); |
1f87f0b5 | 320 | } |
d6cffbbe KK |
321 | /* |
322 | * Prune dentries for unregistered sysctls: namespaced sysctls | |
323 | * can have duplicate names and contaminate dcache very badly. | |
324 | */ | |
325 | proc_sys_prune_dcache(p); | |
1f87f0b5 EB |
326 | /* |
327 | * do not remove from the list until nobody holds it; walking the | |
328 | * list in do_sysctl() relies on that. | |
329 | */ | |
ace0c791 | 330 | spin_lock(&sysctl_lock); |
8425d6aa | 331 | erase_header(p); |
1f87f0b5 EB |
332 | } |
333 | ||
1f87f0b5 EB |
334 | static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) |
335 | { | |
ab4a1f24 | 336 | BUG_ON(!head); |
1f87f0b5 EB |
337 | spin_lock(&sysctl_lock); |
338 | if (!use_table(head)) | |
339 | head = ERR_PTR(-ENOENT); | |
340 | spin_unlock(&sysctl_lock); | |
341 | return head; | |
342 | } | |
343 | ||
344 | static void sysctl_head_finish(struct ctl_table_header *head) | |
345 | { | |
346 | if (!head) | |
347 | return; | |
348 | spin_lock(&sysctl_lock); | |
349 | unuse_table(head); | |
350 | spin_unlock(&sysctl_lock); | |
351 | } | |
352 | ||
353 | static struct ctl_table_set * | |
13bcc6a2 | 354 | lookup_header_set(struct ctl_table_root *root) |
1f87f0b5 EB |
355 | { |
356 | struct ctl_table_set *set = &root->default_set; | |
357 | if (root->lookup) | |
13bcc6a2 | 358 | set = root->lookup(root); |
1f87f0b5 EB |
359 | return set; |
360 | } | |
361 | ||
076c3eed | 362 | static struct ctl_table *lookup_entry(struct ctl_table_header **phead, |
7ec66d06 | 363 | struct ctl_dir *dir, |
076c3eed EB |
364 | const char *name, int namelen) |
365 | { | |
366 | struct ctl_table_header *head; | |
367 | struct ctl_table *entry; | |
076c3eed EB |
368 | |
369 | spin_lock(&sysctl_lock); | |
0e47c99d EB |
370 | entry = find_entry(&head, dir, name, namelen); |
371 | if (entry && use_table(head)) | |
372 | *phead = head; | |
373 | else | |
374 | entry = NULL; | |
076c3eed EB |
375 | spin_unlock(&sysctl_lock); |
376 | return entry; | |
377 | } | |
378 | ||
ac13ac6f | 379 | static struct ctl_node *first_usable_entry(struct rb_node *node) |
1f87f0b5 | 380 | { |
ac13ac6f | 381 | struct ctl_node *ctl_node; |
1f87f0b5 | 382 | |
ac13ac6f EB |
383 | for (;node; node = rb_next(node)) { |
384 | ctl_node = rb_entry(node, struct ctl_node, node); | |
385 | if (use_table(ctl_node->header)) | |
386 | return ctl_node; | |
1f87f0b5 | 387 | } |
1f87f0b5 EB |
388 | return NULL; |
389 | } | |
390 | ||
7ec66d06 | 391 | static void first_entry(struct ctl_dir *dir, |
6a75ce16 EB |
392 | struct ctl_table_header **phead, struct ctl_table **pentry) |
393 | { | |
ac13ac6f | 394 | struct ctl_table_header *head = NULL; |
7ec66d06 | 395 | struct ctl_table *entry = NULL; |
ac13ac6f | 396 | struct ctl_node *ctl_node; |
6a75ce16 EB |
397 | |
398 | spin_lock(&sysctl_lock); | |
ac13ac6f | 399 | ctl_node = first_usable_entry(rb_first(&dir->root)); |
6a75ce16 | 400 | spin_unlock(&sysctl_lock); |
ac13ac6f EB |
401 | if (ctl_node) { |
402 | head = ctl_node->header; | |
403 | entry = &head->ctl_table[ctl_node - head->node]; | |
404 | } | |
6a75ce16 EB |
405 | *phead = head; |
406 | *pentry = entry; | |
407 | } | |
408 | ||
7ec66d06 | 409 | static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) |
1f87f0b5 | 410 | { |
6a75ce16 EB |
411 | struct ctl_table_header *head = *phead; |
412 | struct ctl_table *entry = *pentry; | |
ac13ac6f | 413 | struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; |
6a75ce16 | 414 | |
ac13ac6f EB |
415 | spin_lock(&sysctl_lock); |
416 | unuse_table(head); | |
417 | ||
418 | ctl_node = first_usable_entry(rb_next(&ctl_node->node)); | |
419 | spin_unlock(&sysctl_lock); | |
420 | head = NULL; | |
421 | if (ctl_node) { | |
422 | head = ctl_node->header; | |
423 | entry = &head->ctl_table[ctl_node - head->node]; | |
6a75ce16 EB |
424 | } |
425 | *phead = head; | |
426 | *pentry = entry; | |
1f87f0b5 EB |
427 | } |
428 | ||
1f87f0b5 EB |
429 | /* |
430 | * sysctl_perm does NOT grant the superuser all rights automatically, because | |
431 | * some sysctl variables are readonly even to root. | |
432 | */ | |
433 | ||
434 | static int test_perm(int mode, int op) | |
435 | { | |
091bd3ea | 436 | if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) |
1f87f0b5 | 437 | mode >>= 6; |
091bd3ea | 438 | else if (in_egroup_p(GLOBAL_ROOT_GID)) |
1f87f0b5 EB |
439 | mode >>= 3; |
440 | if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) | |
441 | return 0; | |
442 | return -EACCES; | |
443 | } | |
444 | ||
73f7ef43 | 445 | static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) |
1f87f0b5 | 446 | { |
73f7ef43 | 447 | struct ctl_table_root *root = head->root; |
1f87f0b5 EB |
448 | int mode; |
449 | ||
450 | if (root->permissions) | |
73f7ef43 | 451 | mode = root->permissions(head, table); |
1f87f0b5 EB |
452 | else |
453 | mode = table->mode; | |
454 | ||
455 | return test_perm(mode, op); | |
456 | } | |
457 | ||
9043476f AV |
458 | static struct inode *proc_sys_make_inode(struct super_block *sb, |
459 | struct ctl_table_header *head, struct ctl_table *table) | |
77b14db5 | 460 | { |
e79c6a4f | 461 | struct ctl_table_root *root = head->root; |
77b14db5 | 462 | struct inode *inode; |
9043476f | 463 | struct proc_inode *ei; |
77b14db5 | 464 | |
9043476f | 465 | inode = new_inode(sb); |
77b14db5 | 466 | if (!inode) |
ea5751cc | 467 | return ERR_PTR(-ENOMEM); |
77b14db5 | 468 | |
85fe4025 CH |
469 | inode->i_ino = get_next_ino(); |
470 | ||
77b14db5 | 471 | ei = PROC_I(inode); |
9043476f | 472 | |
d6cffbbe | 473 | spin_lock(&sysctl_lock); |
ace0c791 EB |
474 | if (unlikely(head->unregistering)) { |
475 | spin_unlock(&sysctl_lock); | |
476 | iput(inode); | |
ea5751cc | 477 | return ERR_PTR(-ENOENT); |
ace0c791 EB |
478 | } |
479 | ei->sysctl = head; | |
480 | ei->sysctl_entry = table; | |
2fd1d2c4 | 481 | hlist_add_head_rcu(&ei->sysctl_inodes, &head->inodes); |
d6cffbbe KK |
482 | head->count++; |
483 | spin_unlock(&sysctl_lock); | |
484 | ||
078cd827 | 485 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
9043476f | 486 | inode->i_mode = table->mode; |
7ec66d06 | 487 | if (!S_ISDIR(table->mode)) { |
9043476f AV |
488 | inode->i_mode |= S_IFREG; |
489 | inode->i_op = &proc_sys_inode_operations; | |
490 | inode->i_fop = &proc_sys_file_operations; | |
491 | } else { | |
492 | inode->i_mode |= S_IFDIR; | |
9043476f AV |
493 | inode->i_op = &proc_sys_dir_operations; |
494 | inode->i_fop = &proc_sys_dir_file_operations; | |
f9bd6733 EB |
495 | if (is_empty_dir(head)) |
496 | make_empty_dir_inode(inode); | |
9043476f | 497 | } |
e79c6a4f DT |
498 | |
499 | if (root->set_ownership) | |
500 | root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); | |
501 | ||
77b14db5 EB |
502 | return inode; |
503 | } | |
504 | ||
d6cffbbe KK |
505 | void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) |
506 | { | |
507 | spin_lock(&sysctl_lock); | |
2fd1d2c4 | 508 | hlist_del_init_rcu(&PROC_I(inode)->sysctl_inodes); |
d6cffbbe KK |
509 | if (!--head->count) |
510 | kfree_rcu(head, rcu); | |
511 | spin_unlock(&sysctl_lock); | |
512 | } | |
513 | ||
81324364 | 514 | static struct ctl_table_header *grab_header(struct inode *inode) |
77b14db5 | 515 | { |
3cc3e046 EB |
516 | struct ctl_table_header *head = PROC_I(inode)->sysctl; |
517 | if (!head) | |
0e47c99d | 518 | head = &sysctl_table_root.default_set.dir.header; |
3cc3e046 | 519 | return sysctl_head_grab(head); |
9043476f | 520 | } |
77b14db5 | 521 | |
9043476f | 522 | static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3 | 523 | unsigned int flags) |
9043476f AV |
524 | { |
525 | struct ctl_table_header *head = grab_header(dir); | |
9043476f | 526 | struct ctl_table_header *h = NULL; |
dc12e909 | 527 | const struct qstr *name = &dentry->d_name; |
9043476f AV |
528 | struct ctl_table *p; |
529 | struct inode *inode; | |
530 | struct dentry *err = ERR_PTR(-ENOENT); | |
7ec66d06 | 531 | struct ctl_dir *ctl_dir; |
0e47c99d | 532 | int ret; |
77b14db5 | 533 | |
9043476f AV |
534 | if (IS_ERR(head)) |
535 | return ERR_CAST(head); | |
77b14db5 | 536 | |
7ec66d06 | 537 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 538 | |
7ec66d06 | 539 | p = lookup_entry(&h, ctl_dir, name->name, name->len); |
9043476f | 540 | if (!p) |
77b14db5 EB |
541 | goto out; |
542 | ||
4e757320 | 543 | if (S_ISLNK(p->mode)) { |
13bcc6a2 | 544 | ret = sysctl_follow_link(&h, &p); |
4e757320 EB |
545 | err = ERR_PTR(ret); |
546 | if (ret) | |
547 | goto out; | |
548 | } | |
0e47c99d | 549 | |
9043476f | 550 | inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); |
ea5751cc ID |
551 | if (IS_ERR(inode)) { |
552 | err = ERR_CAST(inode); | |
77b14db5 | 553 | goto out; |
ea5751cc | 554 | } |
77b14db5 | 555 | |
fb045adb | 556 | d_set_d_op(dentry, &proc_sys_dentry_operations); |
888e2b03 | 557 | err = d_splice_alias(inode, dentry); |
77b14db5 EB |
558 | |
559 | out: | |
6bf61045 FR |
560 | if (h) |
561 | sysctl_head_finish(h); | |
77b14db5 EB |
562 | sysctl_head_finish(head); |
563 | return err; | |
564 | } | |
565 | ||
7708bfb1 PE |
566 | static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, |
567 | size_t count, loff_t *ppos, int write) | |
77b14db5 | 568 | { |
496ad9aa | 569 | struct inode *inode = file_inode(filp); |
9043476f AV |
570 | struct ctl_table_header *head = grab_header(inode); |
571 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
2a2da53b DH |
572 | ssize_t error; |
573 | size_t res; | |
77b14db5 | 574 | |
9043476f AV |
575 | if (IS_ERR(head)) |
576 | return PTR_ERR(head); | |
77b14db5 EB |
577 | |
578 | /* | |
579 | * At this point we know that the sysctl was not unregistered | |
580 | * and won't be until we finish. | |
581 | */ | |
582 | error = -EPERM; | |
73f7ef43 | 583 | if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) |
77b14db5 EB |
584 | goto out; |
585 | ||
9043476f AV |
586 | /* if that can happen at all, it should be -EINVAL, not -EISDIR */ |
587 | error = -EINVAL; | |
588 | if (!table->proc_handler) | |
589 | goto out; | |
590 | ||
77b14db5 EB |
591 | /* careful: calling conventions are nasty here */ |
592 | res = count; | |
8d65af78 | 593 | error = table->proc_handler(table, write, buf, &res, ppos); |
77b14db5 EB |
594 | if (!error) |
595 | error = res; | |
596 | out: | |
597 | sysctl_head_finish(head); | |
598 | ||
599 | return error; | |
600 | } | |
601 | ||
7708bfb1 | 602 | static ssize_t proc_sys_read(struct file *filp, char __user *buf, |
77b14db5 EB |
603 | size_t count, loff_t *ppos) |
604 | { | |
7708bfb1 PE |
605 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); |
606 | } | |
77b14db5 | 607 | |
7708bfb1 PE |
608 | static ssize_t proc_sys_write(struct file *filp, const char __user *buf, |
609 | size_t count, loff_t *ppos) | |
610 | { | |
611 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); | |
77b14db5 EB |
612 | } |
613 | ||
f1ecf068 LDM |
614 | static int proc_sys_open(struct inode *inode, struct file *filp) |
615 | { | |
4e474a00 | 616 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 LDM |
617 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
618 | ||
4e474a00 LDM |
619 | /* sysctl was unregistered */ |
620 | if (IS_ERR(head)) | |
621 | return PTR_ERR(head); | |
622 | ||
f1ecf068 LDM |
623 | if (table->poll) |
624 | filp->private_data = proc_sys_poll_event(table->poll); | |
625 | ||
4e474a00 LDM |
626 | sysctl_head_finish(head); |
627 | ||
f1ecf068 LDM |
628 | return 0; |
629 | } | |
630 | ||
076ccb76 | 631 | static __poll_t proc_sys_poll(struct file *filp, poll_table *wait) |
f1ecf068 | 632 | { |
496ad9aa | 633 | struct inode *inode = file_inode(filp); |
4e474a00 | 634 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 | 635 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
076ccb76 | 636 | __poll_t ret = DEFAULT_POLLMASK; |
4e474a00 LDM |
637 | unsigned long event; |
638 | ||
639 | /* sysctl was unregistered */ | |
640 | if (IS_ERR(head)) | |
a9a08845 | 641 | return EPOLLERR | EPOLLHUP; |
f1ecf068 LDM |
642 | |
643 | if (!table->proc_handler) | |
644 | goto out; | |
645 | ||
646 | if (!table->poll) | |
647 | goto out; | |
648 | ||
4e474a00 | 649 | event = (unsigned long)filp->private_data; |
f1ecf068 LDM |
650 | poll_wait(filp, &table->poll->wait, wait); |
651 | ||
652 | if (event != atomic_read(&table->poll->event)) { | |
653 | filp->private_data = proc_sys_poll_event(table->poll); | |
a9a08845 | 654 | ret = EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; |
f1ecf068 LDM |
655 | } |
656 | ||
657 | out: | |
4e474a00 LDM |
658 | sysctl_head_finish(head); |
659 | ||
f1ecf068 LDM |
660 | return ret; |
661 | } | |
77b14db5 | 662 | |
f0c3b509 AV |
663 | static bool proc_sys_fill_cache(struct file *file, |
664 | struct dir_context *ctx, | |
9043476f AV |
665 | struct ctl_table_header *head, |
666 | struct ctl_table *table) | |
77b14db5 | 667 | { |
f0c3b509 | 668 | struct dentry *child, *dir = file->f_path.dentry; |
77b14db5 EB |
669 | struct inode *inode; |
670 | struct qstr qname; | |
671 | ino_t ino = 0; | |
672 | unsigned type = DT_UNKNOWN; | |
77b14db5 EB |
673 | |
674 | qname.name = table->procname; | |
675 | qname.len = strlen(table->procname); | |
8387ff25 | 676 | qname.hash = full_name_hash(dir, qname.name, qname.len); |
77b14db5 | 677 | |
77b14db5 EB |
678 | child = d_lookup(dir, &qname); |
679 | if (!child) { | |
76aab3ab AV |
680 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
681 | child = d_alloc_parallel(dir, &qname, &wq); | |
682 | if (IS_ERR(child)) | |
683 | return false; | |
684 | if (d_in_lookup(child)) { | |
888e2b03 | 685 | struct dentry *res; |
9043476f | 686 | inode = proc_sys_make_inode(dir->d_sb, head, table); |
ea5751cc | 687 | if (IS_ERR(inode)) { |
76aab3ab | 688 | d_lookup_done(child); |
9043476f | 689 | dput(child); |
f0c3b509 | 690 | return false; |
77b14db5 | 691 | } |
76aab3ab | 692 | d_set_d_op(child, &proc_sys_dentry_operations); |
888e2b03 AV |
693 | res = d_splice_alias(inode, child); |
694 | d_lookup_done(child); | |
695 | if (unlikely(res)) { | |
696 | if (IS_ERR(res)) { | |
697 | dput(child); | |
698 | return false; | |
699 | } | |
700 | dput(child); | |
701 | child = res; | |
702 | } | |
77b14db5 EB |
703 | } |
704 | } | |
2b0143b5 | 705 | inode = d_inode(child); |
9043476f AV |
706 | ino = inode->i_ino; |
707 | type = inode->i_mode >> 12; | |
77b14db5 | 708 | dput(child); |
f0c3b509 | 709 | return dir_emit(ctx, qname.name, qname.len, ino, type); |
9043476f AV |
710 | } |
711 | ||
f0c3b509 AV |
712 | static bool proc_sys_link_fill_cache(struct file *file, |
713 | struct dir_context *ctx, | |
0e47c99d EB |
714 | struct ctl_table_header *head, |
715 | struct ctl_table *table) | |
716 | { | |
f0c3b509 | 717 | bool ret = true; |
a0b0d1c3 | 718 | |
0e47c99d | 719 | head = sysctl_head_grab(head); |
a0b0d1c3 DK |
720 | if (IS_ERR(head)) |
721 | return false; | |
0e47c99d | 722 | |
835b94e0 DK |
723 | /* It is not an error if we can not follow the link ignore it */ |
724 | if (sysctl_follow_link(&head, &table)) | |
725 | goto out; | |
0e47c99d | 726 | |
f0c3b509 | 727 | ret = proc_sys_fill_cache(file, ctx, head, table); |
0e47c99d EB |
728 | out: |
729 | sysctl_head_finish(head); | |
730 | return ret; | |
731 | } | |
732 | ||
e5eea098 | 733 | static int scan(struct ctl_table_header *head, struct ctl_table *table, |
9043476f | 734 | unsigned long *pos, struct file *file, |
f0c3b509 | 735 | struct dir_context *ctx) |
9043476f | 736 | { |
f0c3b509 | 737 | bool res; |
9043476f | 738 | |
f0c3b509 AV |
739 | if ((*pos)++ < ctx->pos) |
740 | return true; | |
9043476f | 741 | |
0e47c99d | 742 | if (unlikely(S_ISLNK(table->mode))) |
f0c3b509 | 743 | res = proc_sys_link_fill_cache(file, ctx, head, table); |
0e47c99d | 744 | else |
f0c3b509 | 745 | res = proc_sys_fill_cache(file, ctx, head, table); |
9043476f | 746 | |
f0c3b509 AV |
747 | if (res) |
748 | ctx->pos = *pos; | |
9043476f | 749 | |
6a75ce16 | 750 | return res; |
77b14db5 EB |
751 | } |
752 | ||
f0c3b509 | 753 | static int proc_sys_readdir(struct file *file, struct dir_context *ctx) |
77b14db5 | 754 | { |
f0c3b509 | 755 | struct ctl_table_header *head = grab_header(file_inode(file)); |
9043476f | 756 | struct ctl_table_header *h = NULL; |
6a75ce16 | 757 | struct ctl_table *entry; |
7ec66d06 | 758 | struct ctl_dir *ctl_dir; |
77b14db5 | 759 | unsigned long pos; |
9043476f AV |
760 | |
761 | if (IS_ERR(head)) | |
762 | return PTR_ERR(head); | |
77b14db5 | 763 | |
7ec66d06 | 764 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 765 | |
f0c3b509 | 766 | if (!dir_emit_dots(file, ctx)) |
93362fa4 | 767 | goto out; |
f0c3b509 | 768 | |
77b14db5 EB |
769 | pos = 2; |
770 | ||
7ec66d06 | 771 | for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { |
f0c3b509 | 772 | if (!scan(h, entry, &pos, file, ctx)) { |
9043476f AV |
773 | sysctl_head_finish(h); |
774 | break; | |
77b14db5 EB |
775 | } |
776 | } | |
93362fa4 | 777 | out: |
77b14db5 | 778 | sysctl_head_finish(head); |
f0c3b509 | 779 | return 0; |
77b14db5 EB |
780 | } |
781 | ||
10556cb2 | 782 | static int proc_sys_permission(struct inode *inode, int mask) |
77b14db5 EB |
783 | { |
784 | /* | |
785 | * sysctl entries that are not writeable, | |
786 | * are _NOT_ writeable, capabilities or not. | |
787 | */ | |
f696a365 MS |
788 | struct ctl_table_header *head; |
789 | struct ctl_table *table; | |
77b14db5 EB |
790 | int error; |
791 | ||
f696a365 MS |
792 | /* Executable files are not allowed under /proc/sys/ */ |
793 | if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) | |
794 | return -EACCES; | |
795 | ||
796 | head = grab_header(inode); | |
9043476f AV |
797 | if (IS_ERR(head)) |
798 | return PTR_ERR(head); | |
77b14db5 | 799 | |
f696a365 | 800 | table = PROC_I(inode)->sysctl_entry; |
9043476f AV |
801 | if (!table) /* global root - r-xr-xr-x */ |
802 | error = mask & MAY_WRITE ? -EACCES : 0; | |
803 | else /* Use the permissions on the sysctl table entry */ | |
73f7ef43 | 804 | error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); |
77b14db5 | 805 | |
77b14db5 EB |
806 | sysctl_head_finish(head); |
807 | return error; | |
808 | } | |
809 | ||
810 | static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) | |
811 | { | |
2b0143b5 | 812 | struct inode *inode = d_inode(dentry); |
77b14db5 EB |
813 | int error; |
814 | ||
815 | if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) | |
816 | return -EPERM; | |
817 | ||
31051c85 | 818 | error = setattr_prepare(dentry, attr); |
1025774c CH |
819 | if (error) |
820 | return error; | |
821 | ||
1025774c CH |
822 | setattr_copy(inode, attr); |
823 | mark_inode_dirty(inode); | |
824 | return 0; | |
77b14db5 EB |
825 | } |
826 | ||
a528d35e DH |
827 | static int proc_sys_getattr(const struct path *path, struct kstat *stat, |
828 | u32 request_mask, unsigned int query_flags) | |
9043476f | 829 | { |
a528d35e | 830 | struct inode *inode = d_inode(path->dentry); |
9043476f AV |
831 | struct ctl_table_header *head = grab_header(inode); |
832 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
833 | ||
834 | if (IS_ERR(head)) | |
835 | return PTR_ERR(head); | |
836 | ||
837 | generic_fillattr(inode, stat); | |
838 | if (table) | |
839 | stat->mode = (stat->mode & S_IFMT) | table->mode; | |
840 | ||
841 | sysctl_head_finish(head); | |
842 | return 0; | |
843 | } | |
844 | ||
77b14db5 | 845 | static const struct file_operations proc_sys_file_operations = { |
f1ecf068 LDM |
846 | .open = proc_sys_open, |
847 | .poll = proc_sys_poll, | |
77b14db5 EB |
848 | .read = proc_sys_read, |
849 | .write = proc_sys_write, | |
6038f373 | 850 | .llseek = default_llseek, |
9043476f AV |
851 | }; |
852 | ||
853 | static const struct file_operations proc_sys_dir_file_operations = { | |
887df078 | 854 | .read = generic_read_dir, |
f50752ea | 855 | .iterate_shared = proc_sys_readdir, |
3222a3e5 | 856 | .llseek = generic_file_llseek, |
77b14db5 EB |
857 | }; |
858 | ||
03a44825 | 859 | static const struct inode_operations proc_sys_inode_operations = { |
9043476f AV |
860 | .permission = proc_sys_permission, |
861 | .setattr = proc_sys_setattr, | |
862 | .getattr = proc_sys_getattr, | |
863 | }; | |
864 | ||
865 | static const struct inode_operations proc_sys_dir_operations = { | |
77b14db5 EB |
866 | .lookup = proc_sys_lookup, |
867 | .permission = proc_sys_permission, | |
868 | .setattr = proc_sys_setattr, | |
9043476f | 869 | .getattr = proc_sys_getattr, |
77b14db5 EB |
870 | }; |
871 | ||
0b728e19 | 872 | static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) |
77b14db5 | 873 | { |
0b728e19 | 874 | if (flags & LOOKUP_RCU) |
34286d66 | 875 | return -ECHILD; |
2b0143b5 | 876 | return !PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
877 | } |
878 | ||
fe15ce44 | 879 | static int proc_sys_delete(const struct dentry *dentry) |
9043476f | 880 | { |
2b0143b5 | 881 | return !!PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
882 | } |
883 | ||
1f87f0b5 EB |
884 | static int sysctl_is_seen(struct ctl_table_header *p) |
885 | { | |
886 | struct ctl_table_set *set = p->set; | |
887 | int res; | |
888 | spin_lock(&sysctl_lock); | |
889 | if (p->unregistering) | |
890 | res = 0; | |
891 | else if (!set->is_seen) | |
892 | res = 1; | |
893 | else | |
894 | res = set->is_seen(set); | |
895 | spin_unlock(&sysctl_lock); | |
896 | return res; | |
897 | } | |
898 | ||
6fa67e70 | 899 | static int proc_sys_compare(const struct dentry *dentry, |
621e155a | 900 | unsigned int len, const char *str, const struct qstr *name) |
9043476f | 901 | { |
dfef6dcd | 902 | struct ctl_table_header *head; |
da53be12 LT |
903 | struct inode *inode; |
904 | ||
31e6b01f NP |
905 | /* Although proc doesn't have negative dentries, rcu-walk means |
906 | * that inode here can be NULL */ | |
dfef6dcd | 907 | /* AV: can it, indeed? */ |
2b0143b5 | 908 | inode = d_inode_rcu(dentry); |
31e6b01f | 909 | if (!inode) |
dfef6dcd | 910 | return 1; |
621e155a | 911 | if (name->len != len) |
9043476f | 912 | return 1; |
621e155a | 913 | if (memcmp(name->name, str, len)) |
9043476f | 914 | return 1; |
dfef6dcd AV |
915 | head = rcu_dereference(PROC_I(inode)->sysctl); |
916 | return !head || !sysctl_is_seen(head); | |
77b14db5 EB |
917 | } |
918 | ||
d72f71eb | 919 | static const struct dentry_operations proc_sys_dentry_operations = { |
77b14db5 | 920 | .d_revalidate = proc_sys_revalidate, |
9043476f AV |
921 | .d_delete = proc_sys_delete, |
922 | .d_compare = proc_sys_compare, | |
77b14db5 EB |
923 | }; |
924 | ||
0e47c99d EB |
925 | static struct ctl_dir *find_subdir(struct ctl_dir *dir, |
926 | const char *name, int namelen) | |
1f87f0b5 | 927 | { |
7ec66d06 EB |
928 | struct ctl_table_header *head; |
929 | struct ctl_table *entry; | |
1f87f0b5 | 930 | |
0e47c99d | 931 | entry = find_entry(&head, dir, name, namelen); |
7ec66d06 EB |
932 | if (!entry) |
933 | return ERR_PTR(-ENOENT); | |
51f72f4a EB |
934 | if (!S_ISDIR(entry->mode)) |
935 | return ERR_PTR(-ENOTDIR); | |
936 | return container_of(head, struct ctl_dir, header); | |
7ec66d06 EB |
937 | } |
938 | ||
939 | static struct ctl_dir *new_dir(struct ctl_table_set *set, | |
0e47c99d | 940 | const char *name, int namelen) |
7ec66d06 EB |
941 | { |
942 | struct ctl_table *table; | |
943 | struct ctl_dir *new; | |
ac13ac6f | 944 | struct ctl_node *node; |
7ec66d06 | 945 | char *new_name; |
1f87f0b5 | 946 | |
ac13ac6f EB |
947 | new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + |
948 | sizeof(struct ctl_table)*2 + namelen + 1, | |
949 | GFP_KERNEL); | |
7ec66d06 | 950 | if (!new) |
1f87f0b5 EB |
951 | return NULL; |
952 | ||
ac13ac6f EB |
953 | node = (struct ctl_node *)(new + 1); |
954 | table = (struct ctl_table *)(node + 1); | |
7ec66d06 EB |
955 | new_name = (char *)(table + 2); |
956 | memcpy(new_name, name, namelen); | |
957 | new_name[namelen] = '\0'; | |
958 | table[0].procname = new_name; | |
959 | table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; | |
ac13ac6f | 960 | init_header(&new->header, set->dir.header.root, set, node, table); |
7ec66d06 EB |
961 | |
962 | return new; | |
1f87f0b5 EB |
963 | } |
964 | ||
60f126d9 EB |
965 | /** |
966 | * get_subdir - find or create a subdir with the specified name. | |
967 | * @dir: Directory to create the subdirectory in | |
968 | * @name: The name of the subdirectory to find or create | |
969 | * @namelen: The length of name | |
970 | * | |
971 | * Takes a directory with an elevated reference count so we know that | |
972 | * if we drop the lock the directory will not go away. Upon success | |
973 | * the reference is moved from @dir to the returned subdirectory. | |
974 | * Upon error an error code is returned and the reference on @dir is | |
975 | * simply dropped. | |
976 | */ | |
0e47c99d EB |
977 | static struct ctl_dir *get_subdir(struct ctl_dir *dir, |
978 | const char *name, int namelen) | |
1f87f0b5 | 979 | { |
0e47c99d | 980 | struct ctl_table_set *set = dir->header.set; |
7ec66d06 | 981 | struct ctl_dir *subdir, *new = NULL; |
0eb97f38 | 982 | int err; |
1f87f0b5 | 983 | |
7ec66d06 | 984 | spin_lock(&sysctl_lock); |
0e47c99d | 985 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
986 | if (!IS_ERR(subdir)) |
987 | goto found; | |
988 | if (PTR_ERR(subdir) != -ENOENT) | |
989 | goto failed; | |
990 | ||
991 | spin_unlock(&sysctl_lock); | |
992 | new = new_dir(set, name, namelen); | |
993 | spin_lock(&sysctl_lock); | |
994 | subdir = ERR_PTR(-ENOMEM); | |
995 | if (!new) | |
996 | goto failed; | |
997 | ||
60f126d9 | 998 | /* Was the subdir added while we dropped the lock? */ |
0e47c99d | 999 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
1000 | if (!IS_ERR(subdir)) |
1001 | goto found; | |
1002 | if (PTR_ERR(subdir) != -ENOENT) | |
1003 | goto failed; | |
1004 | ||
60f126d9 | 1005 | /* Nope. Use the our freshly made directory entry. */ |
0eb97f38 EB |
1006 | err = insert_header(dir, &new->header); |
1007 | subdir = ERR_PTR(err); | |
1008 | if (err) | |
0e47c99d | 1009 | goto failed; |
7ec66d06 EB |
1010 | subdir = new; |
1011 | found: | |
1012 | subdir->header.nreg++; | |
1013 | failed: | |
a1c83681 | 1014 | if (IS_ERR(subdir)) { |
87ebdc00 | 1015 | pr_err("sysctl could not get directory: "); |
6980128f | 1016 | sysctl_print_dir(dir); |
87ebdc00 | 1017 | pr_cont("/%*.*s %ld\n", |
7ec66d06 | 1018 | namelen, namelen, name, PTR_ERR(subdir)); |
1f87f0b5 | 1019 | } |
7ec66d06 EB |
1020 | drop_sysctl_table(&dir->header); |
1021 | if (new) | |
1022 | drop_sysctl_table(&new->header); | |
1023 | spin_unlock(&sysctl_lock); | |
1024 | return subdir; | |
1f87f0b5 EB |
1025 | } |
1026 | ||
0e47c99d EB |
1027 | static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) |
1028 | { | |
1029 | struct ctl_dir *parent; | |
1030 | const char *procname; | |
1031 | if (!dir->header.parent) | |
1032 | return &set->dir; | |
1033 | parent = xlate_dir(set, dir->header.parent); | |
1034 | if (IS_ERR(parent)) | |
1035 | return parent; | |
1036 | procname = dir->header.ctl_table[0].procname; | |
1037 | return find_subdir(parent, procname, strlen(procname)); | |
1038 | } | |
1039 | ||
1040 | static int sysctl_follow_link(struct ctl_table_header **phead, | |
13bcc6a2 | 1041 | struct ctl_table **pentry) |
0e47c99d EB |
1042 | { |
1043 | struct ctl_table_header *head; | |
1044 | struct ctl_table_root *root; | |
1045 | struct ctl_table_set *set; | |
1046 | struct ctl_table *entry; | |
1047 | struct ctl_dir *dir; | |
1048 | int ret; | |
1049 | ||
0e47c99d EB |
1050 | ret = 0; |
1051 | spin_lock(&sysctl_lock); | |
1052 | root = (*pentry)->data; | |
13bcc6a2 | 1053 | set = lookup_header_set(root); |
0e47c99d EB |
1054 | dir = xlate_dir(set, (*phead)->parent); |
1055 | if (IS_ERR(dir)) | |
1056 | ret = PTR_ERR(dir); | |
1057 | else { | |
1058 | const char *procname = (*pentry)->procname; | |
1059 | head = NULL; | |
1060 | entry = find_entry(&head, dir, procname, strlen(procname)); | |
1061 | ret = -ENOENT; | |
1062 | if (entry && use_table(head)) { | |
1063 | unuse_table(*phead); | |
1064 | *phead = head; | |
1065 | *pentry = entry; | |
1066 | ret = 0; | |
1067 | } | |
1068 | } | |
1069 | ||
1070 | spin_unlock(&sysctl_lock); | |
1071 | return ret; | |
1072 | } | |
1073 | ||
7c60c48f | 1074 | static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) |
1f87f0b5 | 1075 | { |
7c60c48f EB |
1076 | struct va_format vaf; |
1077 | va_list args; | |
1f87f0b5 | 1078 | |
7c60c48f EB |
1079 | va_start(args, fmt); |
1080 | vaf.fmt = fmt; | |
1081 | vaf.va = &args; | |
1082 | ||
87ebdc00 AM |
1083 | pr_err("sysctl table check failed: %s/%s %pV\n", |
1084 | path, table->procname, &vaf); | |
1f87f0b5 | 1085 | |
7c60c48f EB |
1086 | va_end(args); |
1087 | return -EINVAL; | |
1f87f0b5 EB |
1088 | } |
1089 | ||
4f2fec00 LR |
1090 | static int sysctl_check_table_array(const char *path, struct ctl_table *table) |
1091 | { | |
1092 | int err = 0; | |
1093 | ||
61d9b56a LR |
1094 | if ((table->proc_handler == proc_douintvec) || |
1095 | (table->proc_handler == proc_douintvec_minmax)) { | |
4f2fec00 | 1096 | if (table->maxlen != sizeof(unsigned int)) |
64a11f3d | 1097 | err |= sysctl_err(path, table, "array not allowed"); |
4f2fec00 LR |
1098 | } |
1099 | ||
1100 | return err; | |
1101 | } | |
1102 | ||
7c60c48f | 1103 | static int sysctl_check_table(const char *path, struct ctl_table *table) |
1f87f0b5 | 1104 | { |
7c60c48f | 1105 | int err = 0; |
1f87f0b5 | 1106 | for (; table->procname; table++) { |
1f87f0b5 | 1107 | if (table->child) |
89c5b53b | 1108 | err |= sysctl_err(path, table, "Not a file"); |
7c60c48f EB |
1109 | |
1110 | if ((table->proc_handler == proc_dostring) || | |
1111 | (table->proc_handler == proc_dointvec) || | |
1680a386 | 1112 | (table->proc_handler == proc_douintvec) || |
61d9b56a | 1113 | (table->proc_handler == proc_douintvec_minmax) || |
7c60c48f EB |
1114 | (table->proc_handler == proc_dointvec_minmax) || |
1115 | (table->proc_handler == proc_dointvec_jiffies) || | |
1116 | (table->proc_handler == proc_dointvec_userhz_jiffies) || | |
1117 | (table->proc_handler == proc_dointvec_ms_jiffies) || | |
1118 | (table->proc_handler == proc_doulongvec_minmax) || | |
1119 | (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { | |
1120 | if (!table->data) | |
89c5b53b | 1121 | err |= sysctl_err(path, table, "No data"); |
7c60c48f | 1122 | if (!table->maxlen) |
89c5b53b | 1123 | err |= sysctl_err(path, table, "No maxlen"); |
4f2fec00 LR |
1124 | else |
1125 | err |= sysctl_check_table_array(path, table); | |
7c60c48f EB |
1126 | } |
1127 | if (!table->proc_handler) | |
89c5b53b | 1128 | err |= sysctl_err(path, table, "No proc_handler"); |
7c60c48f EB |
1129 | |
1130 | if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) | |
89c5b53b | 1131 | err |= sysctl_err(path, table, "bogus .mode 0%o", |
7c60c48f | 1132 | table->mode); |
1f87f0b5 | 1133 | } |
7c60c48f | 1134 | return err; |
1f87f0b5 | 1135 | } |
1f87f0b5 | 1136 | |
0e47c99d EB |
1137 | static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, |
1138 | struct ctl_table_root *link_root) | |
1139 | { | |
1140 | struct ctl_table *link_table, *entry, *link; | |
1141 | struct ctl_table_header *links; | |
ac13ac6f | 1142 | struct ctl_node *node; |
0e47c99d EB |
1143 | char *link_name; |
1144 | int nr_entries, name_bytes; | |
1145 | ||
1146 | name_bytes = 0; | |
1147 | nr_entries = 0; | |
1148 | for (entry = table; entry->procname; entry++) { | |
1149 | nr_entries++; | |
1150 | name_bytes += strlen(entry->procname) + 1; | |
1151 | } | |
1152 | ||
1153 | links = kzalloc(sizeof(struct ctl_table_header) + | |
ac13ac6f | 1154 | sizeof(struct ctl_node)*nr_entries + |
0e47c99d EB |
1155 | sizeof(struct ctl_table)*(nr_entries + 1) + |
1156 | name_bytes, | |
1157 | GFP_KERNEL); | |
1158 | ||
1159 | if (!links) | |
1160 | return NULL; | |
1161 | ||
ac13ac6f EB |
1162 | node = (struct ctl_node *)(links + 1); |
1163 | link_table = (struct ctl_table *)(node + nr_entries); | |
0e47c99d EB |
1164 | link_name = (char *)&link_table[nr_entries + 1]; |
1165 | ||
1166 | for (link = link_table, entry = table; entry->procname; link++, entry++) { | |
1167 | int len = strlen(entry->procname) + 1; | |
1168 | memcpy(link_name, entry->procname, len); | |
1169 | link->procname = link_name; | |
1170 | link->mode = S_IFLNK|S_IRWXUGO; | |
1171 | link->data = link_root; | |
1172 | link_name += len; | |
1173 | } | |
ac13ac6f | 1174 | init_header(links, dir->header.root, dir->header.set, node, link_table); |
0e47c99d EB |
1175 | links->nreg = nr_entries; |
1176 | ||
1177 | return links; | |
1178 | } | |
1179 | ||
1180 | static bool get_links(struct ctl_dir *dir, | |
1181 | struct ctl_table *table, struct ctl_table_root *link_root) | |
1182 | { | |
1183 | struct ctl_table_header *head; | |
1184 | struct ctl_table *entry, *link; | |
1185 | ||
1186 | /* Are there links available for every entry in table? */ | |
1187 | for (entry = table; entry->procname; entry++) { | |
1188 | const char *procname = entry->procname; | |
1189 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1190 | if (!link) | |
1191 | return false; | |
1192 | if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) | |
1193 | continue; | |
1194 | if (S_ISLNK(link->mode) && (link->data == link_root)) | |
1195 | continue; | |
1196 | return false; | |
1197 | } | |
1198 | ||
1199 | /* The checks passed. Increase the registration count on the links */ | |
1200 | for (entry = table; entry->procname; entry++) { | |
1201 | const char *procname = entry->procname; | |
1202 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1203 | head->nreg++; | |
1204 | } | |
1205 | return true; | |
1206 | } | |
1207 | ||
1208 | static int insert_links(struct ctl_table_header *head) | |
1209 | { | |
1210 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1211 | struct ctl_dir *core_parent = NULL; | |
1212 | struct ctl_table_header *links; | |
1213 | int err; | |
1214 | ||
1215 | if (head->set == root_set) | |
1216 | return 0; | |
1217 | ||
1218 | core_parent = xlate_dir(root_set, head->parent); | |
1219 | if (IS_ERR(core_parent)) | |
1220 | return 0; | |
1221 | ||
1222 | if (get_links(core_parent, head->ctl_table, head->root)) | |
1223 | return 0; | |
1224 | ||
1225 | core_parent->header.nreg++; | |
1226 | spin_unlock(&sysctl_lock); | |
1227 | ||
1228 | links = new_links(core_parent, head->ctl_table, head->root); | |
1229 | ||
1230 | spin_lock(&sysctl_lock); | |
1231 | err = -ENOMEM; | |
1232 | if (!links) | |
1233 | goto out; | |
1234 | ||
1235 | err = 0; | |
1236 | if (get_links(core_parent, head->ctl_table, head->root)) { | |
1237 | kfree(links); | |
1238 | goto out; | |
1239 | } | |
1240 | ||
1241 | err = insert_header(core_parent, links); | |
1242 | if (err) | |
1243 | kfree(links); | |
1244 | out: | |
1245 | drop_sysctl_table(&core_parent->header); | |
1246 | return err; | |
1247 | } | |
1248 | ||
1f87f0b5 | 1249 | /** |
f728019b | 1250 | * __register_sysctl_table - register a leaf sysctl table |
60a47a2e | 1251 | * @set: Sysctl tree to register on |
1f87f0b5 EB |
1252 | * @path: The path to the directory the sysctl table is in. |
1253 | * @table: the top-level table structure | |
1254 | * | |
1255 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1256 | * array. A completely 0 filled entry terminates the table. | |
1257 | * | |
1258 | * The members of the &struct ctl_table structure are used as follows: | |
1259 | * | |
1260 | * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not | |
1261 | * enter a sysctl file | |
1262 | * | |
1263 | * data - a pointer to data for use by proc_handler | |
1264 | * | |
1265 | * maxlen - the maximum size in bytes of the data | |
1266 | * | |
f728019b | 1267 | * mode - the file permissions for the /proc/sys file |
1f87f0b5 | 1268 | * |
f728019b | 1269 | * child - must be %NULL. |
1f87f0b5 EB |
1270 | * |
1271 | * proc_handler - the text handler routine (described below) | |
1272 | * | |
1f87f0b5 EB |
1273 | * extra1, extra2 - extra pointers usable by the proc handler routines |
1274 | * | |
1275 | * Leaf nodes in the sysctl tree will be represented by a single file | |
1276 | * under /proc; non-leaf nodes will be represented by directories. | |
1277 | * | |
f728019b EB |
1278 | * There must be a proc_handler routine for any terminal nodes. |
1279 | * Several default handlers are available to cover common cases - | |
1f87f0b5 EB |
1280 | * |
1281 | * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), | |
1282 | * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), | |
1283 | * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() | |
1284 | * | |
1285 | * It is the handler's job to read the input buffer from user memory | |
1286 | * and process it. The handler should return 0 on success. | |
1287 | * | |
1288 | * This routine returns %NULL on a failure to register, and a pointer | |
1289 | * to the table header on success. | |
1290 | */ | |
6e9d5164 | 1291 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 1292 | struct ctl_table_set *set, |
6e9d5164 | 1293 | const char *path, struct ctl_table *table) |
1f87f0b5 | 1294 | { |
60a47a2e | 1295 | struct ctl_table_root *root = set->dir.header.root; |
1f87f0b5 | 1296 | struct ctl_table_header *header; |
6e9d5164 | 1297 | const char *name, *nextname; |
7ec66d06 | 1298 | struct ctl_dir *dir; |
ac13ac6f EB |
1299 | struct ctl_table *entry; |
1300 | struct ctl_node *node; | |
1301 | int nr_entries = 0; | |
1302 | ||
1303 | for (entry = table; entry->procname; entry++) | |
1304 | nr_entries++; | |
1f87f0b5 | 1305 | |
ac13ac6f EB |
1306 | header = kzalloc(sizeof(struct ctl_table_header) + |
1307 | sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); | |
1f87f0b5 EB |
1308 | if (!header) |
1309 | return NULL; | |
1310 | ||
ac13ac6f EB |
1311 | node = (struct ctl_node *)(header + 1); |
1312 | init_header(header, root, set, node, table); | |
7ec66d06 EB |
1313 | if (sysctl_check_table(path, table)) |
1314 | goto fail; | |
1315 | ||
1316 | spin_lock(&sysctl_lock); | |
0e47c99d | 1317 | dir = &set->dir; |
60f126d9 | 1318 | /* Reference moved down the diretory tree get_subdir */ |
7ec66d06 EB |
1319 | dir->header.nreg++; |
1320 | spin_unlock(&sysctl_lock); | |
1f87f0b5 | 1321 | |
7ec66d06 | 1322 | /* Find the directory for the ctl_table */ |
6e9d5164 EB |
1323 | for (name = path; name; name = nextname) { |
1324 | int namelen; | |
1325 | nextname = strchr(name, '/'); | |
1326 | if (nextname) { | |
1327 | namelen = nextname - name; | |
1328 | nextname++; | |
1329 | } else { | |
1330 | namelen = strlen(name); | |
1331 | } | |
1332 | if (namelen == 0) | |
1333 | continue; | |
1f87f0b5 | 1334 | |
0e47c99d | 1335 | dir = get_subdir(dir, name, namelen); |
7ec66d06 EB |
1336 | if (IS_ERR(dir)) |
1337 | goto fail; | |
1f87f0b5 | 1338 | } |
0e47c99d | 1339 | |
1f87f0b5 | 1340 | spin_lock(&sysctl_lock); |
0e47c99d | 1341 | if (insert_header(dir, header)) |
7ec66d06 | 1342 | goto fail_put_dir_locked; |
0e47c99d | 1343 | |
7ec66d06 | 1344 | drop_sysctl_table(&dir->header); |
1f87f0b5 EB |
1345 | spin_unlock(&sysctl_lock); |
1346 | ||
1347 | return header; | |
0e47c99d | 1348 | |
7ec66d06 EB |
1349 | fail_put_dir_locked: |
1350 | drop_sysctl_table(&dir->header); | |
7c60c48f EB |
1351 | spin_unlock(&sysctl_lock); |
1352 | fail: | |
1353 | kfree(header); | |
1354 | dump_stack(); | |
1355 | return NULL; | |
1f87f0b5 EB |
1356 | } |
1357 | ||
fea478d4 EB |
1358 | /** |
1359 | * register_sysctl - register a sysctl table | |
1360 | * @path: The path to the directory the sysctl table is in. | |
1361 | * @table: the table structure | |
1362 | * | |
1363 | * Register a sysctl table. @table should be a filled in ctl_table | |
1364 | * array. A completely 0 filled entry terminates the table. | |
1365 | * | |
1366 | * See __register_sysctl_table for more details. | |
1367 | */ | |
1368 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) | |
1369 | { | |
1370 | return __register_sysctl_table(&sysctl_table_root.default_set, | |
1371 | path, table); | |
1372 | } | |
1373 | EXPORT_SYMBOL(register_sysctl); | |
1374 | ||
6e9d5164 EB |
1375 | static char *append_path(const char *path, char *pos, const char *name) |
1376 | { | |
1377 | int namelen; | |
1378 | namelen = strlen(name); | |
1379 | if (((pos - path) + namelen + 2) >= PATH_MAX) | |
1380 | return NULL; | |
1381 | memcpy(pos, name, namelen); | |
1382 | pos[namelen] = '/'; | |
1383 | pos[namelen + 1] = '\0'; | |
1384 | pos += namelen + 1; | |
1385 | return pos; | |
1386 | } | |
1387 | ||
f728019b EB |
1388 | static int count_subheaders(struct ctl_table *table) |
1389 | { | |
1390 | int has_files = 0; | |
1391 | int nr_subheaders = 0; | |
1392 | struct ctl_table *entry; | |
1393 | ||
1394 | /* special case: no directory and empty directory */ | |
1395 | if (!table || !table->procname) | |
1396 | return 1; | |
1397 | ||
1398 | for (entry = table; entry->procname; entry++) { | |
1399 | if (entry->child) | |
1400 | nr_subheaders += count_subheaders(entry->child); | |
1401 | else | |
1402 | has_files = 1; | |
1403 | } | |
1404 | return nr_subheaders + has_files; | |
1405 | } | |
1406 | ||
1407 | static int register_leaf_sysctl_tables(const char *path, char *pos, | |
60a47a2e | 1408 | struct ctl_table_header ***subheader, struct ctl_table_set *set, |
f728019b EB |
1409 | struct ctl_table *table) |
1410 | { | |
1411 | struct ctl_table *ctl_table_arg = NULL; | |
1412 | struct ctl_table *entry, *files; | |
1413 | int nr_files = 0; | |
1414 | int nr_dirs = 0; | |
1415 | int err = -ENOMEM; | |
1416 | ||
1417 | for (entry = table; entry->procname; entry++) { | |
1418 | if (entry->child) | |
1419 | nr_dirs++; | |
1420 | else | |
1421 | nr_files++; | |
1422 | } | |
1423 | ||
1424 | files = table; | |
1425 | /* If there are mixed files and directories we need a new table */ | |
1426 | if (nr_dirs && nr_files) { | |
1427 | struct ctl_table *new; | |
6396bb22 | 1428 | files = kcalloc(nr_files + 1, sizeof(struct ctl_table), |
f728019b EB |
1429 | GFP_KERNEL); |
1430 | if (!files) | |
1431 | goto out; | |
1432 | ||
1433 | ctl_table_arg = files; | |
1434 | for (new = files, entry = table; entry->procname; entry++) { | |
1435 | if (entry->child) | |
1436 | continue; | |
1437 | *new = *entry; | |
1438 | new++; | |
1439 | } | |
1440 | } | |
1441 | ||
1442 | /* Register everything except a directory full of subdirectories */ | |
1443 | if (nr_files || !nr_dirs) { | |
1444 | struct ctl_table_header *header; | |
60a47a2e | 1445 | header = __register_sysctl_table(set, path, files); |
f728019b EB |
1446 | if (!header) { |
1447 | kfree(ctl_table_arg); | |
1448 | goto out; | |
1449 | } | |
1450 | ||
1451 | /* Remember if we need to free the file table */ | |
1452 | header->ctl_table_arg = ctl_table_arg; | |
1453 | **subheader = header; | |
1454 | (*subheader)++; | |
1455 | } | |
1456 | ||
1457 | /* Recurse into the subdirectories. */ | |
1458 | for (entry = table; entry->procname; entry++) { | |
1459 | char *child_pos; | |
1460 | ||
1461 | if (!entry->child) | |
1462 | continue; | |
1463 | ||
1464 | err = -ENAMETOOLONG; | |
1465 | child_pos = append_path(path, pos, entry->procname); | |
1466 | if (!child_pos) | |
1467 | goto out; | |
1468 | ||
1469 | err = register_leaf_sysctl_tables(path, child_pos, subheader, | |
60a47a2e | 1470 | set, entry->child); |
f728019b EB |
1471 | pos[0] = '\0'; |
1472 | if (err) | |
1473 | goto out; | |
1474 | } | |
1475 | err = 0; | |
1476 | out: | |
1477 | /* On failure our caller will unregister all registered subheaders */ | |
1478 | return err; | |
1479 | } | |
1480 | ||
6e9d5164 EB |
1481 | /** |
1482 | * __register_sysctl_paths - register a sysctl table hierarchy | |
60a47a2e | 1483 | * @set: Sysctl tree to register on |
6e9d5164 EB |
1484 | * @path: The path to the directory the sysctl table is in. |
1485 | * @table: the top-level table structure | |
1486 | * | |
1487 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1488 | * array. A completely 0 filled entry terminates the table. | |
1489 | * | |
1490 | * See __register_sysctl_table for more details. | |
1491 | */ | |
1492 | struct ctl_table_header *__register_sysctl_paths( | |
60a47a2e | 1493 | struct ctl_table_set *set, |
6e9d5164 EB |
1494 | const struct ctl_path *path, struct ctl_table *table) |
1495 | { | |
ec6a5266 | 1496 | struct ctl_table *ctl_table_arg = table; |
f728019b EB |
1497 | int nr_subheaders = count_subheaders(table); |
1498 | struct ctl_table_header *header = NULL, **subheaders, **subheader; | |
6e9d5164 EB |
1499 | const struct ctl_path *component; |
1500 | char *new_path, *pos; | |
1501 | ||
1502 | pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); | |
1503 | if (!new_path) | |
1504 | return NULL; | |
1505 | ||
1506 | pos[0] = '\0'; | |
1507 | for (component = path; component->procname; component++) { | |
1508 | pos = append_path(new_path, pos, component->procname); | |
1509 | if (!pos) | |
1510 | goto out; | |
1511 | } | |
ec6a5266 EB |
1512 | while (table->procname && table->child && !table[1].procname) { |
1513 | pos = append_path(new_path, pos, table->procname); | |
1514 | if (!pos) | |
1515 | goto out; | |
1516 | table = table->child; | |
1517 | } | |
f728019b | 1518 | if (nr_subheaders == 1) { |
60a47a2e | 1519 | header = __register_sysctl_table(set, new_path, table); |
f728019b EB |
1520 | if (header) |
1521 | header->ctl_table_arg = ctl_table_arg; | |
1522 | } else { | |
1523 | header = kzalloc(sizeof(*header) + | |
1524 | sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); | |
1525 | if (!header) | |
1526 | goto out; | |
1527 | ||
1528 | subheaders = (struct ctl_table_header **) (header + 1); | |
1529 | subheader = subheaders; | |
ec6a5266 | 1530 | header->ctl_table_arg = ctl_table_arg; |
f728019b EB |
1531 | |
1532 | if (register_leaf_sysctl_tables(new_path, pos, &subheader, | |
60a47a2e | 1533 | set, table)) |
f728019b EB |
1534 | goto err_register_leaves; |
1535 | } | |
1536 | ||
6e9d5164 EB |
1537 | out: |
1538 | kfree(new_path); | |
1539 | return header; | |
f728019b EB |
1540 | |
1541 | err_register_leaves: | |
1542 | while (subheader > subheaders) { | |
1543 | struct ctl_table_header *subh = *(--subheader); | |
1544 | struct ctl_table *table = subh->ctl_table_arg; | |
1545 | unregister_sysctl_table(subh); | |
1546 | kfree(table); | |
1547 | } | |
1548 | kfree(header); | |
1549 | header = NULL; | |
1550 | goto out; | |
6e9d5164 EB |
1551 | } |
1552 | ||
1f87f0b5 EB |
1553 | /** |
1554 | * register_sysctl_table_path - register a sysctl table hierarchy | |
1555 | * @path: The path to the directory the sysctl table is in. | |
1556 | * @table: the top-level table structure | |
1557 | * | |
1558 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1559 | * array. A completely 0 filled entry terminates the table. | |
1560 | * | |
1561 | * See __register_sysctl_paths for more details. | |
1562 | */ | |
1563 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, | |
1564 | struct ctl_table *table) | |
1565 | { | |
60a47a2e | 1566 | return __register_sysctl_paths(&sysctl_table_root.default_set, |
1f87f0b5 EB |
1567 | path, table); |
1568 | } | |
1569 | EXPORT_SYMBOL(register_sysctl_paths); | |
1570 | ||
1571 | /** | |
1572 | * register_sysctl_table - register a sysctl table hierarchy | |
1573 | * @table: the top-level table structure | |
1574 | * | |
1575 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1576 | * array. A completely 0 filled entry terminates the table. | |
1577 | * | |
1578 | * See register_sysctl_paths for more details. | |
1579 | */ | |
1580 | struct ctl_table_header *register_sysctl_table(struct ctl_table *table) | |
1581 | { | |
1582 | static const struct ctl_path null_path[] = { {} }; | |
1583 | ||
1584 | return register_sysctl_paths(null_path, table); | |
1585 | } | |
1586 | EXPORT_SYMBOL(register_sysctl_table); | |
1587 | ||
0e47c99d EB |
1588 | static void put_links(struct ctl_table_header *header) |
1589 | { | |
1590 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1591 | struct ctl_table_root *root = header->root; | |
1592 | struct ctl_dir *parent = header->parent; | |
1593 | struct ctl_dir *core_parent; | |
1594 | struct ctl_table *entry; | |
1595 | ||
1596 | if (header->set == root_set) | |
1597 | return; | |
1598 | ||
1599 | core_parent = xlate_dir(root_set, parent); | |
1600 | if (IS_ERR(core_parent)) | |
1601 | return; | |
1602 | ||
1603 | for (entry = header->ctl_table; entry->procname; entry++) { | |
1604 | struct ctl_table_header *link_head; | |
1605 | struct ctl_table *link; | |
1606 | const char *name = entry->procname; | |
1607 | ||
1608 | link = find_entry(&link_head, core_parent, name, strlen(name)); | |
1609 | if (link && | |
1610 | ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || | |
1611 | (S_ISLNK(link->mode) && (link->data == root)))) { | |
1612 | drop_sysctl_table(link_head); | |
1613 | } | |
1614 | else { | |
87ebdc00 | 1615 | pr_err("sysctl link missing during unregister: "); |
0e47c99d | 1616 | sysctl_print_dir(parent); |
87ebdc00 | 1617 | pr_cont("/%s\n", name); |
0e47c99d EB |
1618 | } |
1619 | } | |
1620 | } | |
1621 | ||
938aaa4f EB |
1622 | static void drop_sysctl_table(struct ctl_table_header *header) |
1623 | { | |
7ec66d06 EB |
1624 | struct ctl_dir *parent = header->parent; |
1625 | ||
938aaa4f EB |
1626 | if (--header->nreg) |
1627 | return; | |
1628 | ||
23da9588 Y |
1629 | if (parent) |
1630 | put_links(header); | |
938aaa4f | 1631 | start_unregistering(header); |
938aaa4f EB |
1632 | if (!--header->count) |
1633 | kfree_rcu(header, rcu); | |
7ec66d06 EB |
1634 | |
1635 | if (parent) | |
1636 | drop_sysctl_table(&parent->header); | |
938aaa4f EB |
1637 | } |
1638 | ||
1f87f0b5 EB |
1639 | /** |
1640 | * unregister_sysctl_table - unregister a sysctl table hierarchy | |
1641 | * @header: the header returned from register_sysctl_table | |
1642 | * | |
1643 | * Unregisters the sysctl table and all children. proc entries may not | |
1644 | * actually be removed until they are no longer used by anyone. | |
1645 | */ | |
1646 | void unregister_sysctl_table(struct ctl_table_header * header) | |
1647 | { | |
f728019b | 1648 | int nr_subheaders; |
1f87f0b5 EB |
1649 | might_sleep(); |
1650 | ||
1651 | if (header == NULL) | |
1652 | return; | |
1653 | ||
f728019b EB |
1654 | nr_subheaders = count_subheaders(header->ctl_table_arg); |
1655 | if (unlikely(nr_subheaders > 1)) { | |
1656 | struct ctl_table_header **subheaders; | |
1657 | int i; | |
1658 | ||
1659 | subheaders = (struct ctl_table_header **)(header + 1); | |
1660 | for (i = nr_subheaders -1; i >= 0; i--) { | |
1661 | struct ctl_table_header *subh = subheaders[i]; | |
1662 | struct ctl_table *table = subh->ctl_table_arg; | |
1663 | unregister_sysctl_table(subh); | |
1664 | kfree(table); | |
1665 | } | |
1666 | kfree(header); | |
1667 | return; | |
1668 | } | |
1669 | ||
1f87f0b5 | 1670 | spin_lock(&sysctl_lock); |
938aaa4f | 1671 | drop_sysctl_table(header); |
1f87f0b5 EB |
1672 | spin_unlock(&sysctl_lock); |
1673 | } | |
1674 | EXPORT_SYMBOL(unregister_sysctl_table); | |
1675 | ||
0e47c99d | 1676 | void setup_sysctl_set(struct ctl_table_set *set, |
9eb47c26 | 1677 | struct ctl_table_root *root, |
1f87f0b5 EB |
1678 | int (*is_seen)(struct ctl_table_set *)) |
1679 | { | |
1347440d | 1680 | memset(set, 0, sizeof(*set)); |
0e47c99d | 1681 | set->is_seen = is_seen; |
ac13ac6f | 1682 | init_header(&set->dir.header, root, set, NULL, root_table); |
1f87f0b5 EB |
1683 | } |
1684 | ||
97324cd8 EB |
1685 | void retire_sysctl_set(struct ctl_table_set *set) |
1686 | { | |
ac13ac6f | 1687 | WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); |
97324cd8 | 1688 | } |
1f87f0b5 | 1689 | |
1e0edd3f | 1690 | int __init proc_sys_init(void) |
77b14db5 | 1691 | { |
e1675231 AD |
1692 | struct proc_dir_entry *proc_sys_root; |
1693 | ||
77b14db5 | 1694 | proc_sys_root = proc_mkdir("sys", NULL); |
9043476f AV |
1695 | proc_sys_root->proc_iops = &proc_sys_dir_operations; |
1696 | proc_sys_root->proc_fops = &proc_sys_dir_file_operations; | |
77b14db5 | 1697 | proc_sys_root->nlink = 0; |
de4e83bd EB |
1698 | |
1699 | return sysctl_init(); | |
77b14db5 | 1700 | } |