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