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> |
7b146ceb | 16 | #include <linux/bpf-cgroup.h> |
77b14db5 EB |
17 | #include "internal.h" |
18 | ||
d72f71eb | 19 | static const struct dentry_operations proc_sys_dentry_operations; |
77b14db5 | 20 | static const struct file_operations proc_sys_file_operations; |
03a44825 | 21 | static const struct inode_operations proc_sys_inode_operations; |
9043476f AV |
22 | static const struct file_operations proc_sys_dir_file_operations; |
23 | static const struct inode_operations proc_sys_dir_operations; | |
77b14db5 | 24 | |
eec4844f MC |
25 | /* shared constants to be used in various sysctls */ |
26 | const int sysctl_vals[] = { 0, 1, INT_MAX }; | |
27 | EXPORT_SYMBOL(sysctl_vals); | |
28 | ||
f9bd6733 EB |
29 | /* Support for permanently empty directories */ |
30 | ||
31 | struct ctl_table sysctl_mount_point[] = { | |
32 | { } | |
33 | }; | |
34 | ||
35 | static bool is_empty_dir(struct ctl_table_header *head) | |
36 | { | |
37 | return head->ctl_table[0].child == sysctl_mount_point; | |
38 | } | |
39 | ||
40 | static void set_empty_dir(struct ctl_dir *dir) | |
41 | { | |
42 | dir->header.ctl_table[0].child = sysctl_mount_point; | |
43 | } | |
44 | ||
45 | static void clear_empty_dir(struct ctl_dir *dir) | |
46 | ||
47 | { | |
48 | dir->header.ctl_table[0].child = NULL; | |
49 | } | |
50 | ||
f1ecf068 LDM |
51 | void proc_sys_poll_notify(struct ctl_table_poll *poll) |
52 | { | |
53 | if (!poll) | |
54 | return; | |
55 | ||
56 | atomic_inc(&poll->event); | |
57 | wake_up_interruptible(&poll->wait); | |
58 | } | |
59 | ||
a194558e EB |
60 | static struct ctl_table root_table[] = { |
61 | { | |
62 | .procname = "", | |
7ec66d06 | 63 | .mode = S_IFDIR|S_IRUGO|S_IXUGO, |
a194558e EB |
64 | }, |
65 | { } | |
66 | }; | |
0e47c99d | 67 | static struct ctl_table_root sysctl_table_root = { |
0e47c99d | 68 | .default_set.dir.header = { |
7ec66d06 EB |
69 | {{.count = 1, |
70 | .nreg = 1, | |
ac13ac6f | 71 | .ctl_table = root_table }}, |
0e47c99d | 72 | .ctl_table_arg = root_table, |
7ec66d06 EB |
73 | .root = &sysctl_table_root, |
74 | .set = &sysctl_table_root.default_set, | |
75 | }, | |
1f87f0b5 | 76 | }; |
1f87f0b5 EB |
77 | |
78 | static DEFINE_SPINLOCK(sysctl_lock); | |
79 | ||
7ec66d06 | 80 | static void drop_sysctl_table(struct ctl_table_header *header); |
0e47c99d | 81 | static int sysctl_follow_link(struct ctl_table_header **phead, |
13bcc6a2 | 82 | struct ctl_table **pentry); |
0e47c99d EB |
83 | static int insert_links(struct ctl_table_header *head); |
84 | static void put_links(struct ctl_table_header *header); | |
7ec66d06 | 85 | |
6980128f EB |
86 | static void sysctl_print_dir(struct ctl_dir *dir) |
87 | { | |
88 | if (dir->header.parent) | |
89 | sysctl_print_dir(dir->header.parent); | |
87ebdc00 | 90 | pr_cont("%s/", dir->header.ctl_table[0].procname); |
6980128f EB |
91 | } |
92 | ||
076c3eed EB |
93 | static int namecmp(const char *name1, int len1, const char *name2, int len2) |
94 | { | |
95 | int minlen; | |
96 | int cmp; | |
97 | ||
98 | minlen = len1; | |
99 | if (minlen > len2) | |
100 | minlen = len2; | |
101 | ||
102 | cmp = memcmp(name1, name2, minlen); | |
103 | if (cmp == 0) | |
104 | cmp = len1 - len2; | |
105 | return cmp; | |
106 | } | |
107 | ||
60f126d9 | 108 | /* Called under sysctl_lock */ |
076c3eed | 109 | static struct ctl_table *find_entry(struct ctl_table_header **phead, |
0e47c99d | 110 | struct ctl_dir *dir, const char *name, int namelen) |
076c3eed EB |
111 | { |
112 | struct ctl_table_header *head; | |
113 | struct ctl_table *entry; | |
ac13ac6f | 114 | struct rb_node *node = dir->root.rb_node; |
076c3eed | 115 | |
ac13ac6f EB |
116 | while (node) |
117 | { | |
118 | struct ctl_node *ctl_node; | |
119 | const char *procname; | |
120 | int cmp; | |
121 | ||
122 | ctl_node = rb_entry(node, struct ctl_node, node); | |
123 | head = ctl_node->header; | |
124 | entry = &head->ctl_table[ctl_node - head->node]; | |
125 | procname = entry->procname; | |
126 | ||
127 | cmp = namecmp(name, namelen, procname, strlen(procname)); | |
128 | if (cmp < 0) | |
129 | node = node->rb_left; | |
130 | else if (cmp > 0) | |
131 | node = node->rb_right; | |
132 | else { | |
133 | *phead = head; | |
134 | return entry; | |
076c3eed EB |
135 | } |
136 | } | |
137 | return NULL; | |
138 | } | |
139 | ||
ac13ac6f EB |
140 | static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) |
141 | { | |
142 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
143 | struct rb_node **p = &head->parent->root.rb_node; | |
144 | struct rb_node *parent = NULL; | |
145 | const char *name = entry->procname; | |
146 | int namelen = strlen(name); | |
147 | ||
148 | while (*p) { | |
149 | struct ctl_table_header *parent_head; | |
150 | struct ctl_table *parent_entry; | |
151 | struct ctl_node *parent_node; | |
152 | const char *parent_name; | |
153 | int cmp; | |
154 | ||
155 | parent = *p; | |
156 | parent_node = rb_entry(parent, struct ctl_node, node); | |
157 | parent_head = parent_node->header; | |
158 | parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; | |
159 | parent_name = parent_entry->procname; | |
160 | ||
161 | cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); | |
162 | if (cmp < 0) | |
163 | p = &(*p)->rb_left; | |
164 | else if (cmp > 0) | |
165 | p = &(*p)->rb_right; | |
166 | else { | |
87ebdc00 | 167 | pr_err("sysctl duplicate entry: "); |
ac13ac6f | 168 | sysctl_print_dir(head->parent); |
87ebdc00 | 169 | pr_cont("/%s\n", entry->procname); |
ac13ac6f EB |
170 | return -EEXIST; |
171 | } | |
172 | } | |
173 | ||
174 | rb_link_node(node, parent, p); | |
ea5272f5 | 175 | rb_insert_color(node, &head->parent->root); |
ac13ac6f EB |
176 | return 0; |
177 | } | |
178 | ||
179 | static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) | |
180 | { | |
181 | struct rb_node *node = &head->node[entry - head->ctl_table].node; | |
182 | ||
183 | rb_erase(node, &head->parent->root); | |
184 | } | |
185 | ||
e0d04529 EB |
186 | static void init_header(struct ctl_table_header *head, |
187 | struct ctl_table_root *root, struct ctl_table_set *set, | |
ac13ac6f | 188 | struct ctl_node *node, struct ctl_table *table) |
e0d04529 | 189 | { |
7ec66d06 | 190 | head->ctl_table = table; |
e0d04529 | 191 | head->ctl_table_arg = table; |
e0d04529 EB |
192 | head->used = 0; |
193 | head->count = 1; | |
194 | head->nreg = 1; | |
195 | head->unregistering = NULL; | |
196 | head->root = root; | |
197 | head->set = set; | |
198 | head->parent = NULL; | |
ac13ac6f | 199 | head->node = node; |
2fd1d2c4 | 200 | INIT_HLIST_HEAD(&head->inodes); |
ac13ac6f EB |
201 | if (node) { |
202 | struct ctl_table *entry; | |
4c199a93 | 203 | for (entry = table; entry->procname; entry++, node++) |
ac13ac6f | 204 | node->header = head; |
ac13ac6f | 205 | } |
e0d04529 EB |
206 | } |
207 | ||
8425d6aa EB |
208 | static void erase_header(struct ctl_table_header *head) |
209 | { | |
ac13ac6f EB |
210 | struct ctl_table *entry; |
211 | for (entry = head->ctl_table; entry->procname; entry++) | |
212 | erase_entry(head, entry); | |
8425d6aa EB |
213 | } |
214 | ||
0e47c99d | 215 | static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) |
8425d6aa | 216 | { |
ac13ac6f | 217 | struct ctl_table *entry; |
0e47c99d EB |
218 | int err; |
219 | ||
f9bd6733 EB |
220 | /* Is this a permanently empty directory? */ |
221 | if (is_empty_dir(&dir->header)) | |
222 | return -EROFS; | |
223 | ||
224 | /* Am I creating a permanently empty directory? */ | |
225 | if (header->ctl_table == sysctl_mount_point) { | |
226 | if (!RB_EMPTY_ROOT(&dir->root)) | |
227 | return -EINVAL; | |
228 | set_empty_dir(dir); | |
229 | } | |
230 | ||
0e47c99d | 231 | dir->header.nreg++; |
7ec66d06 | 232 | header->parent = dir; |
0e47c99d EB |
233 | err = insert_links(header); |
234 | if (err) | |
235 | goto fail_links; | |
ac13ac6f EB |
236 | for (entry = header->ctl_table; entry->procname; entry++) { |
237 | err = insert_entry(header, entry); | |
238 | if (err) | |
239 | goto fail; | |
240 | } | |
0e47c99d | 241 | return 0; |
ac13ac6f EB |
242 | fail: |
243 | erase_header(header); | |
244 | put_links(header); | |
0e47c99d | 245 | fail_links: |
f9bd6733 EB |
246 | if (header->ctl_table == sysctl_mount_point) |
247 | clear_empty_dir(dir); | |
0e47c99d EB |
248 | header->parent = NULL; |
249 | drop_sysctl_table(&dir->header); | |
250 | return err; | |
8425d6aa EB |
251 | } |
252 | ||
1f87f0b5 EB |
253 | /* called under sysctl_lock */ |
254 | static int use_table(struct ctl_table_header *p) | |
255 | { | |
256 | if (unlikely(p->unregistering)) | |
257 | return 0; | |
258 | p->used++; | |
259 | return 1; | |
260 | } | |
261 | ||
262 | /* called under sysctl_lock */ | |
263 | static void unuse_table(struct ctl_table_header *p) | |
264 | { | |
265 | if (!--p->used) | |
266 | if (unlikely(p->unregistering)) | |
267 | complete(p->unregistering); | |
268 | } | |
269 | ||
f90f3caf | 270 | static void proc_sys_invalidate_dcache(struct ctl_table_header *head) |
d6cffbbe | 271 | { |
f90f3caf | 272 | proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock); |
d6cffbbe KK |
273 | } |
274 | ||
1f87f0b5 EB |
275 | /* called under sysctl_lock, will reacquire if has to wait */ |
276 | static void start_unregistering(struct ctl_table_header *p) | |
277 | { | |
278 | /* | |
279 | * if p->used is 0, nobody will ever touch that entry again; | |
280 | * we'll eliminate all paths to it before dropping sysctl_lock | |
281 | */ | |
282 | if (unlikely(p->used)) { | |
283 | struct completion wait; | |
284 | init_completion(&wait); | |
285 | p->unregistering = &wait; | |
286 | spin_unlock(&sysctl_lock); | |
287 | wait_for_completion(&wait); | |
1f87f0b5 EB |
288 | } else { |
289 | /* anything non-NULL; we'll never dereference it */ | |
290 | p->unregistering = ERR_PTR(-EINVAL); | |
ace0c791 | 291 | spin_unlock(&sysctl_lock); |
1f87f0b5 | 292 | } |
d6cffbbe | 293 | /* |
f90f3caf | 294 | * Invalidate dentries for unregistered sysctls: namespaced sysctls |
d6cffbbe KK |
295 | * can have duplicate names and contaminate dcache very badly. |
296 | */ | |
f90f3caf | 297 | proc_sys_invalidate_dcache(p); |
1f87f0b5 EB |
298 | /* |
299 | * do not remove from the list until nobody holds it; walking the | |
300 | * list in do_sysctl() relies on that. | |
301 | */ | |
ace0c791 | 302 | spin_lock(&sysctl_lock); |
8425d6aa | 303 | erase_header(p); |
1f87f0b5 EB |
304 | } |
305 | ||
1f87f0b5 EB |
306 | static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) |
307 | { | |
ab4a1f24 | 308 | BUG_ON(!head); |
1f87f0b5 EB |
309 | spin_lock(&sysctl_lock); |
310 | if (!use_table(head)) | |
311 | head = ERR_PTR(-ENOENT); | |
312 | spin_unlock(&sysctl_lock); | |
313 | return head; | |
314 | } | |
315 | ||
316 | static void sysctl_head_finish(struct ctl_table_header *head) | |
317 | { | |
318 | if (!head) | |
319 | return; | |
320 | spin_lock(&sysctl_lock); | |
321 | unuse_table(head); | |
322 | spin_unlock(&sysctl_lock); | |
323 | } | |
324 | ||
325 | static struct ctl_table_set * | |
13bcc6a2 | 326 | lookup_header_set(struct ctl_table_root *root) |
1f87f0b5 EB |
327 | { |
328 | struct ctl_table_set *set = &root->default_set; | |
329 | if (root->lookup) | |
13bcc6a2 | 330 | set = root->lookup(root); |
1f87f0b5 EB |
331 | return set; |
332 | } | |
333 | ||
076c3eed | 334 | static struct ctl_table *lookup_entry(struct ctl_table_header **phead, |
7ec66d06 | 335 | struct ctl_dir *dir, |
076c3eed EB |
336 | const char *name, int namelen) |
337 | { | |
338 | struct ctl_table_header *head; | |
339 | struct ctl_table *entry; | |
076c3eed EB |
340 | |
341 | spin_lock(&sysctl_lock); | |
0e47c99d EB |
342 | entry = find_entry(&head, dir, name, namelen); |
343 | if (entry && use_table(head)) | |
344 | *phead = head; | |
345 | else | |
346 | entry = NULL; | |
076c3eed EB |
347 | spin_unlock(&sysctl_lock); |
348 | return entry; | |
349 | } | |
350 | ||
ac13ac6f | 351 | static struct ctl_node *first_usable_entry(struct rb_node *node) |
1f87f0b5 | 352 | { |
ac13ac6f | 353 | struct ctl_node *ctl_node; |
1f87f0b5 | 354 | |
ac13ac6f EB |
355 | for (;node; node = rb_next(node)) { |
356 | ctl_node = rb_entry(node, struct ctl_node, node); | |
357 | if (use_table(ctl_node->header)) | |
358 | return ctl_node; | |
1f87f0b5 | 359 | } |
1f87f0b5 EB |
360 | return NULL; |
361 | } | |
362 | ||
7ec66d06 | 363 | static void first_entry(struct ctl_dir *dir, |
6a75ce16 EB |
364 | struct ctl_table_header **phead, struct ctl_table **pentry) |
365 | { | |
ac13ac6f | 366 | struct ctl_table_header *head = NULL; |
7ec66d06 | 367 | struct ctl_table *entry = NULL; |
ac13ac6f | 368 | struct ctl_node *ctl_node; |
6a75ce16 EB |
369 | |
370 | spin_lock(&sysctl_lock); | |
ac13ac6f | 371 | ctl_node = first_usable_entry(rb_first(&dir->root)); |
6a75ce16 | 372 | spin_unlock(&sysctl_lock); |
ac13ac6f EB |
373 | if (ctl_node) { |
374 | head = ctl_node->header; | |
375 | entry = &head->ctl_table[ctl_node - head->node]; | |
376 | } | |
6a75ce16 EB |
377 | *phead = head; |
378 | *pentry = entry; | |
379 | } | |
380 | ||
7ec66d06 | 381 | static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) |
1f87f0b5 | 382 | { |
6a75ce16 EB |
383 | struct ctl_table_header *head = *phead; |
384 | struct ctl_table *entry = *pentry; | |
ac13ac6f | 385 | struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; |
6a75ce16 | 386 | |
ac13ac6f EB |
387 | spin_lock(&sysctl_lock); |
388 | unuse_table(head); | |
389 | ||
390 | ctl_node = first_usable_entry(rb_next(&ctl_node->node)); | |
391 | spin_unlock(&sysctl_lock); | |
392 | head = NULL; | |
393 | if (ctl_node) { | |
394 | head = ctl_node->header; | |
395 | entry = &head->ctl_table[ctl_node - head->node]; | |
6a75ce16 EB |
396 | } |
397 | *phead = head; | |
398 | *pentry = entry; | |
1f87f0b5 EB |
399 | } |
400 | ||
1f87f0b5 EB |
401 | /* |
402 | * sysctl_perm does NOT grant the superuser all rights automatically, because | |
403 | * some sysctl variables are readonly even to root. | |
404 | */ | |
405 | ||
406 | static int test_perm(int mode, int op) | |
407 | { | |
091bd3ea | 408 | if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) |
1f87f0b5 | 409 | mode >>= 6; |
091bd3ea | 410 | else if (in_egroup_p(GLOBAL_ROOT_GID)) |
1f87f0b5 EB |
411 | mode >>= 3; |
412 | if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) | |
413 | return 0; | |
414 | return -EACCES; | |
415 | } | |
416 | ||
73f7ef43 | 417 | static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) |
1f87f0b5 | 418 | { |
73f7ef43 | 419 | struct ctl_table_root *root = head->root; |
1f87f0b5 EB |
420 | int mode; |
421 | ||
422 | if (root->permissions) | |
73f7ef43 | 423 | mode = root->permissions(head, table); |
1f87f0b5 EB |
424 | else |
425 | mode = table->mode; | |
426 | ||
427 | return test_perm(mode, op); | |
428 | } | |
429 | ||
9043476f AV |
430 | static struct inode *proc_sys_make_inode(struct super_block *sb, |
431 | struct ctl_table_header *head, struct ctl_table *table) | |
77b14db5 | 432 | { |
e79c6a4f | 433 | struct ctl_table_root *root = head->root; |
77b14db5 | 434 | struct inode *inode; |
9043476f | 435 | struct proc_inode *ei; |
77b14db5 | 436 | |
9043476f | 437 | inode = new_inode(sb); |
77b14db5 | 438 | if (!inode) |
ea5751cc | 439 | return ERR_PTR(-ENOMEM); |
77b14db5 | 440 | |
85fe4025 CH |
441 | inode->i_ino = get_next_ino(); |
442 | ||
77b14db5 | 443 | ei = PROC_I(inode); |
9043476f | 444 | |
d6cffbbe | 445 | spin_lock(&sysctl_lock); |
ace0c791 EB |
446 | if (unlikely(head->unregistering)) { |
447 | spin_unlock(&sysctl_lock); | |
448 | iput(inode); | |
ea5751cc | 449 | return ERR_PTR(-ENOENT); |
ace0c791 EB |
450 | } |
451 | ei->sysctl = head; | |
452 | ei->sysctl_entry = table; | |
0afa5ca8 | 453 | hlist_add_head_rcu(&ei->sibling_inodes, &head->inodes); |
d6cffbbe KK |
454 | head->count++; |
455 | spin_unlock(&sysctl_lock); | |
456 | ||
078cd827 | 457 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
9043476f | 458 | inode->i_mode = table->mode; |
7ec66d06 | 459 | if (!S_ISDIR(table->mode)) { |
9043476f AV |
460 | inode->i_mode |= S_IFREG; |
461 | inode->i_op = &proc_sys_inode_operations; | |
462 | inode->i_fop = &proc_sys_file_operations; | |
463 | } else { | |
464 | inode->i_mode |= S_IFDIR; | |
9043476f AV |
465 | inode->i_op = &proc_sys_dir_operations; |
466 | inode->i_fop = &proc_sys_dir_file_operations; | |
f9bd6733 EB |
467 | if (is_empty_dir(head)) |
468 | make_empty_dir_inode(inode); | |
9043476f | 469 | } |
e79c6a4f DT |
470 | |
471 | if (root->set_ownership) | |
472 | root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); | |
5ec27ec7 RB |
473 | else { |
474 | inode->i_uid = GLOBAL_ROOT_UID; | |
475 | inode->i_gid = GLOBAL_ROOT_GID; | |
476 | } | |
e79c6a4f | 477 | |
77b14db5 EB |
478 | return inode; |
479 | } | |
480 | ||
d6cffbbe KK |
481 | void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) |
482 | { | |
483 | spin_lock(&sysctl_lock); | |
0afa5ca8 | 484 | hlist_del_init_rcu(&PROC_I(inode)->sibling_inodes); |
d6cffbbe KK |
485 | if (!--head->count) |
486 | kfree_rcu(head, rcu); | |
487 | spin_unlock(&sysctl_lock); | |
488 | } | |
489 | ||
81324364 | 490 | static struct ctl_table_header *grab_header(struct inode *inode) |
77b14db5 | 491 | { |
3cc3e046 EB |
492 | struct ctl_table_header *head = PROC_I(inode)->sysctl; |
493 | if (!head) | |
0e47c99d | 494 | head = &sysctl_table_root.default_set.dir.header; |
3cc3e046 | 495 | return sysctl_head_grab(head); |
9043476f | 496 | } |
77b14db5 | 497 | |
9043476f | 498 | static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3 | 499 | unsigned int flags) |
9043476f AV |
500 | { |
501 | struct ctl_table_header *head = grab_header(dir); | |
9043476f | 502 | struct ctl_table_header *h = NULL; |
dc12e909 | 503 | const struct qstr *name = &dentry->d_name; |
9043476f AV |
504 | struct ctl_table *p; |
505 | struct inode *inode; | |
506 | struct dentry *err = ERR_PTR(-ENOENT); | |
7ec66d06 | 507 | struct ctl_dir *ctl_dir; |
0e47c99d | 508 | int ret; |
77b14db5 | 509 | |
9043476f AV |
510 | if (IS_ERR(head)) |
511 | return ERR_CAST(head); | |
77b14db5 | 512 | |
7ec66d06 | 513 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 514 | |
7ec66d06 | 515 | p = lookup_entry(&h, ctl_dir, name->name, name->len); |
9043476f | 516 | if (!p) |
77b14db5 EB |
517 | goto out; |
518 | ||
4e757320 | 519 | if (S_ISLNK(p->mode)) { |
13bcc6a2 | 520 | ret = sysctl_follow_link(&h, &p); |
4e757320 EB |
521 | err = ERR_PTR(ret); |
522 | if (ret) | |
523 | goto out; | |
524 | } | |
0e47c99d | 525 | |
9043476f | 526 | inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); |
ea5751cc ID |
527 | if (IS_ERR(inode)) { |
528 | err = ERR_CAST(inode); | |
77b14db5 | 529 | goto out; |
ea5751cc | 530 | } |
77b14db5 | 531 | |
fb045adb | 532 | d_set_d_op(dentry, &proc_sys_dentry_operations); |
888e2b03 | 533 | err = d_splice_alias(inode, dentry); |
77b14db5 EB |
534 | |
535 | out: | |
6bf61045 FR |
536 | if (h) |
537 | sysctl_head_finish(h); | |
77b14db5 EB |
538 | sysctl_head_finish(head); |
539 | return err; | |
540 | } | |
541 | ||
7708bfb1 PE |
542 | static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, |
543 | size_t count, loff_t *ppos, int write) | |
77b14db5 | 544 | { |
496ad9aa | 545 | struct inode *inode = file_inode(filp); |
9043476f AV |
546 | struct ctl_table_header *head = grab_header(inode); |
547 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
4e63acdf | 548 | void *new_buf = NULL; |
2a2da53b | 549 | ssize_t error; |
77b14db5 | 550 | |
9043476f AV |
551 | if (IS_ERR(head)) |
552 | return PTR_ERR(head); | |
77b14db5 EB |
553 | |
554 | /* | |
555 | * At this point we know that the sysctl was not unregistered | |
556 | * and won't be until we finish. | |
557 | */ | |
558 | error = -EPERM; | |
73f7ef43 | 559 | if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) |
77b14db5 EB |
560 | goto out; |
561 | ||
9043476f AV |
562 | /* if that can happen at all, it should be -EINVAL, not -EISDIR */ |
563 | error = -EINVAL; | |
564 | if (!table->proc_handler) | |
565 | goto out; | |
566 | ||
4e63acdf | 567 | error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, &count, |
e1550bfe | 568 | ppos, &new_buf); |
7b146ceb AI |
569 | if (error) |
570 | goto out; | |
571 | ||
77b14db5 | 572 | /* careful: calling conventions are nasty here */ |
4e63acdf AI |
573 | if (new_buf) { |
574 | mm_segment_t old_fs; | |
575 | ||
576 | old_fs = get_fs(); | |
577 | set_fs(KERNEL_DS); | |
578 | error = table->proc_handler(table, write, (void __user *)new_buf, | |
579 | &count, ppos); | |
580 | set_fs(old_fs); | |
581 | kfree(new_buf); | |
582 | } else { | |
583 | error = table->proc_handler(table, write, buf, &count, ppos); | |
584 | } | |
585 | ||
77b14db5 | 586 | if (!error) |
4e63acdf | 587 | error = count; |
77b14db5 EB |
588 | out: |
589 | sysctl_head_finish(head); | |
590 | ||
591 | return error; | |
592 | } | |
593 | ||
7708bfb1 | 594 | static ssize_t proc_sys_read(struct file *filp, char __user *buf, |
77b14db5 EB |
595 | size_t count, loff_t *ppos) |
596 | { | |
7708bfb1 PE |
597 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); |
598 | } | |
77b14db5 | 599 | |
7708bfb1 PE |
600 | static ssize_t proc_sys_write(struct file *filp, const char __user *buf, |
601 | size_t count, loff_t *ppos) | |
602 | { | |
603 | return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); | |
77b14db5 EB |
604 | } |
605 | ||
f1ecf068 LDM |
606 | static int proc_sys_open(struct inode *inode, struct file *filp) |
607 | { | |
4e474a00 | 608 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 LDM |
609 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
610 | ||
4e474a00 LDM |
611 | /* sysctl was unregistered */ |
612 | if (IS_ERR(head)) | |
613 | return PTR_ERR(head); | |
614 | ||
f1ecf068 LDM |
615 | if (table->poll) |
616 | filp->private_data = proc_sys_poll_event(table->poll); | |
617 | ||
4e474a00 LDM |
618 | sysctl_head_finish(head); |
619 | ||
f1ecf068 LDM |
620 | return 0; |
621 | } | |
622 | ||
076ccb76 | 623 | static __poll_t proc_sys_poll(struct file *filp, poll_table *wait) |
f1ecf068 | 624 | { |
496ad9aa | 625 | struct inode *inode = file_inode(filp); |
4e474a00 | 626 | struct ctl_table_header *head = grab_header(inode); |
f1ecf068 | 627 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
076ccb76 | 628 | __poll_t ret = DEFAULT_POLLMASK; |
4e474a00 LDM |
629 | unsigned long event; |
630 | ||
631 | /* sysctl was unregistered */ | |
632 | if (IS_ERR(head)) | |
a9a08845 | 633 | return EPOLLERR | EPOLLHUP; |
f1ecf068 LDM |
634 | |
635 | if (!table->proc_handler) | |
636 | goto out; | |
637 | ||
638 | if (!table->poll) | |
639 | goto out; | |
640 | ||
4e474a00 | 641 | event = (unsigned long)filp->private_data; |
f1ecf068 LDM |
642 | poll_wait(filp, &table->poll->wait, wait); |
643 | ||
644 | if (event != atomic_read(&table->poll->event)) { | |
645 | filp->private_data = proc_sys_poll_event(table->poll); | |
a9a08845 | 646 | ret = EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; |
f1ecf068 LDM |
647 | } |
648 | ||
649 | out: | |
4e474a00 LDM |
650 | sysctl_head_finish(head); |
651 | ||
f1ecf068 LDM |
652 | return ret; |
653 | } | |
77b14db5 | 654 | |
f0c3b509 AV |
655 | static bool proc_sys_fill_cache(struct file *file, |
656 | struct dir_context *ctx, | |
9043476f AV |
657 | struct ctl_table_header *head, |
658 | struct ctl_table *table) | |
77b14db5 | 659 | { |
f0c3b509 | 660 | struct dentry *child, *dir = file->f_path.dentry; |
77b14db5 EB |
661 | struct inode *inode; |
662 | struct qstr qname; | |
663 | ino_t ino = 0; | |
664 | unsigned type = DT_UNKNOWN; | |
77b14db5 EB |
665 | |
666 | qname.name = table->procname; | |
667 | qname.len = strlen(table->procname); | |
8387ff25 | 668 | qname.hash = full_name_hash(dir, qname.name, qname.len); |
77b14db5 | 669 | |
77b14db5 EB |
670 | child = d_lookup(dir, &qname); |
671 | if (!child) { | |
76aab3ab AV |
672 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
673 | child = d_alloc_parallel(dir, &qname, &wq); | |
674 | if (IS_ERR(child)) | |
675 | return false; | |
676 | if (d_in_lookup(child)) { | |
888e2b03 | 677 | struct dentry *res; |
9043476f | 678 | inode = proc_sys_make_inode(dir->d_sb, head, table); |
ea5751cc | 679 | if (IS_ERR(inode)) { |
76aab3ab | 680 | d_lookup_done(child); |
9043476f | 681 | dput(child); |
f0c3b509 | 682 | return false; |
77b14db5 | 683 | } |
76aab3ab | 684 | d_set_d_op(child, &proc_sys_dentry_operations); |
888e2b03 AV |
685 | res = d_splice_alias(inode, child); |
686 | d_lookup_done(child); | |
687 | if (unlikely(res)) { | |
688 | if (IS_ERR(res)) { | |
689 | dput(child); | |
690 | return false; | |
691 | } | |
692 | dput(child); | |
693 | child = res; | |
694 | } | |
77b14db5 EB |
695 | } |
696 | } | |
2b0143b5 | 697 | inode = d_inode(child); |
9043476f AV |
698 | ino = inode->i_ino; |
699 | type = inode->i_mode >> 12; | |
77b14db5 | 700 | dput(child); |
f0c3b509 | 701 | return dir_emit(ctx, qname.name, qname.len, ino, type); |
9043476f AV |
702 | } |
703 | ||
f0c3b509 AV |
704 | static bool proc_sys_link_fill_cache(struct file *file, |
705 | struct dir_context *ctx, | |
0e47c99d EB |
706 | struct ctl_table_header *head, |
707 | struct ctl_table *table) | |
708 | { | |
f0c3b509 | 709 | bool ret = true; |
a0b0d1c3 | 710 | |
0e47c99d | 711 | head = sysctl_head_grab(head); |
a0b0d1c3 DK |
712 | if (IS_ERR(head)) |
713 | return false; | |
0e47c99d | 714 | |
835b94e0 DK |
715 | /* It is not an error if we can not follow the link ignore it */ |
716 | if (sysctl_follow_link(&head, &table)) | |
717 | goto out; | |
0e47c99d | 718 | |
f0c3b509 | 719 | ret = proc_sys_fill_cache(file, ctx, head, table); |
0e47c99d EB |
720 | out: |
721 | sysctl_head_finish(head); | |
722 | return ret; | |
723 | } | |
724 | ||
e5eea098 | 725 | static int scan(struct ctl_table_header *head, struct ctl_table *table, |
9043476f | 726 | unsigned long *pos, struct file *file, |
f0c3b509 | 727 | struct dir_context *ctx) |
9043476f | 728 | { |
f0c3b509 | 729 | bool res; |
9043476f | 730 | |
f0c3b509 AV |
731 | if ((*pos)++ < ctx->pos) |
732 | return true; | |
9043476f | 733 | |
0e47c99d | 734 | if (unlikely(S_ISLNK(table->mode))) |
f0c3b509 | 735 | res = proc_sys_link_fill_cache(file, ctx, head, table); |
0e47c99d | 736 | else |
f0c3b509 | 737 | res = proc_sys_fill_cache(file, ctx, head, table); |
9043476f | 738 | |
f0c3b509 AV |
739 | if (res) |
740 | ctx->pos = *pos; | |
9043476f | 741 | |
6a75ce16 | 742 | return res; |
77b14db5 EB |
743 | } |
744 | ||
f0c3b509 | 745 | static int proc_sys_readdir(struct file *file, struct dir_context *ctx) |
77b14db5 | 746 | { |
f0c3b509 | 747 | struct ctl_table_header *head = grab_header(file_inode(file)); |
9043476f | 748 | struct ctl_table_header *h = NULL; |
6a75ce16 | 749 | struct ctl_table *entry; |
7ec66d06 | 750 | struct ctl_dir *ctl_dir; |
77b14db5 | 751 | unsigned long pos; |
9043476f AV |
752 | |
753 | if (IS_ERR(head)) | |
754 | return PTR_ERR(head); | |
77b14db5 | 755 | |
7ec66d06 | 756 | ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db5 | 757 | |
f0c3b509 | 758 | if (!dir_emit_dots(file, ctx)) |
93362fa4 | 759 | goto out; |
f0c3b509 | 760 | |
77b14db5 EB |
761 | pos = 2; |
762 | ||
7ec66d06 | 763 | for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { |
f0c3b509 | 764 | if (!scan(h, entry, &pos, file, ctx)) { |
9043476f AV |
765 | sysctl_head_finish(h); |
766 | break; | |
77b14db5 EB |
767 | } |
768 | } | |
93362fa4 | 769 | out: |
77b14db5 | 770 | sysctl_head_finish(head); |
f0c3b509 | 771 | return 0; |
77b14db5 EB |
772 | } |
773 | ||
10556cb2 | 774 | static int proc_sys_permission(struct inode *inode, int mask) |
77b14db5 EB |
775 | { |
776 | /* | |
777 | * sysctl entries that are not writeable, | |
778 | * are _NOT_ writeable, capabilities or not. | |
779 | */ | |
f696a365 MS |
780 | struct ctl_table_header *head; |
781 | struct ctl_table *table; | |
77b14db5 EB |
782 | int error; |
783 | ||
f696a365 MS |
784 | /* Executable files are not allowed under /proc/sys/ */ |
785 | if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) | |
786 | return -EACCES; | |
787 | ||
788 | head = grab_header(inode); | |
9043476f AV |
789 | if (IS_ERR(head)) |
790 | return PTR_ERR(head); | |
77b14db5 | 791 | |
f696a365 | 792 | table = PROC_I(inode)->sysctl_entry; |
9043476f AV |
793 | if (!table) /* global root - r-xr-xr-x */ |
794 | error = mask & MAY_WRITE ? -EACCES : 0; | |
795 | else /* Use the permissions on the sysctl table entry */ | |
73f7ef43 | 796 | error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); |
77b14db5 | 797 | |
77b14db5 EB |
798 | sysctl_head_finish(head); |
799 | return error; | |
800 | } | |
801 | ||
802 | static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) | |
803 | { | |
2b0143b5 | 804 | struct inode *inode = d_inode(dentry); |
77b14db5 EB |
805 | int error; |
806 | ||
807 | if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) | |
808 | return -EPERM; | |
809 | ||
31051c85 | 810 | error = setattr_prepare(dentry, attr); |
1025774c CH |
811 | if (error) |
812 | return error; | |
813 | ||
1025774c CH |
814 | setattr_copy(inode, attr); |
815 | mark_inode_dirty(inode); | |
816 | return 0; | |
77b14db5 EB |
817 | } |
818 | ||
a528d35e DH |
819 | static int proc_sys_getattr(const struct path *path, struct kstat *stat, |
820 | u32 request_mask, unsigned int query_flags) | |
9043476f | 821 | { |
a528d35e | 822 | struct inode *inode = d_inode(path->dentry); |
9043476f AV |
823 | struct ctl_table_header *head = grab_header(inode); |
824 | struct ctl_table *table = PROC_I(inode)->sysctl_entry; | |
825 | ||
826 | if (IS_ERR(head)) | |
827 | return PTR_ERR(head); | |
828 | ||
829 | generic_fillattr(inode, stat); | |
830 | if (table) | |
831 | stat->mode = (stat->mode & S_IFMT) | table->mode; | |
832 | ||
833 | sysctl_head_finish(head); | |
834 | return 0; | |
835 | } | |
836 | ||
77b14db5 | 837 | static const struct file_operations proc_sys_file_operations = { |
f1ecf068 LDM |
838 | .open = proc_sys_open, |
839 | .poll = proc_sys_poll, | |
77b14db5 EB |
840 | .read = proc_sys_read, |
841 | .write = proc_sys_write, | |
6038f373 | 842 | .llseek = default_llseek, |
9043476f AV |
843 | }; |
844 | ||
845 | static const struct file_operations proc_sys_dir_file_operations = { | |
887df078 | 846 | .read = generic_read_dir, |
f50752ea | 847 | .iterate_shared = proc_sys_readdir, |
3222a3e5 | 848 | .llseek = generic_file_llseek, |
77b14db5 EB |
849 | }; |
850 | ||
03a44825 | 851 | static const struct inode_operations proc_sys_inode_operations = { |
9043476f AV |
852 | .permission = proc_sys_permission, |
853 | .setattr = proc_sys_setattr, | |
854 | .getattr = proc_sys_getattr, | |
855 | }; | |
856 | ||
857 | static const struct inode_operations proc_sys_dir_operations = { | |
77b14db5 EB |
858 | .lookup = proc_sys_lookup, |
859 | .permission = proc_sys_permission, | |
860 | .setattr = proc_sys_setattr, | |
9043476f | 861 | .getattr = proc_sys_getattr, |
77b14db5 EB |
862 | }; |
863 | ||
0b728e19 | 864 | static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) |
77b14db5 | 865 | { |
0b728e19 | 866 | if (flags & LOOKUP_RCU) |
34286d66 | 867 | return -ECHILD; |
2b0143b5 | 868 | return !PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
869 | } |
870 | ||
fe15ce44 | 871 | static int proc_sys_delete(const struct dentry *dentry) |
9043476f | 872 | { |
2b0143b5 | 873 | return !!PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f AV |
874 | } |
875 | ||
1f87f0b5 EB |
876 | static int sysctl_is_seen(struct ctl_table_header *p) |
877 | { | |
878 | struct ctl_table_set *set = p->set; | |
879 | int res; | |
880 | spin_lock(&sysctl_lock); | |
881 | if (p->unregistering) | |
882 | res = 0; | |
883 | else if (!set->is_seen) | |
884 | res = 1; | |
885 | else | |
886 | res = set->is_seen(set); | |
887 | spin_unlock(&sysctl_lock); | |
888 | return res; | |
889 | } | |
890 | ||
6fa67e70 | 891 | static int proc_sys_compare(const struct dentry *dentry, |
621e155a | 892 | unsigned int len, const char *str, const struct qstr *name) |
9043476f | 893 | { |
dfef6dcd | 894 | struct ctl_table_header *head; |
da53be12 LT |
895 | struct inode *inode; |
896 | ||
31e6b01f NP |
897 | /* Although proc doesn't have negative dentries, rcu-walk means |
898 | * that inode here can be NULL */ | |
dfef6dcd | 899 | /* AV: can it, indeed? */ |
2b0143b5 | 900 | inode = d_inode_rcu(dentry); |
31e6b01f | 901 | if (!inode) |
dfef6dcd | 902 | return 1; |
621e155a | 903 | if (name->len != len) |
9043476f | 904 | return 1; |
621e155a | 905 | if (memcmp(name->name, str, len)) |
9043476f | 906 | return 1; |
dfef6dcd AV |
907 | head = rcu_dereference(PROC_I(inode)->sysctl); |
908 | return !head || !sysctl_is_seen(head); | |
77b14db5 EB |
909 | } |
910 | ||
d72f71eb | 911 | static const struct dentry_operations proc_sys_dentry_operations = { |
77b14db5 | 912 | .d_revalidate = proc_sys_revalidate, |
9043476f AV |
913 | .d_delete = proc_sys_delete, |
914 | .d_compare = proc_sys_compare, | |
77b14db5 EB |
915 | }; |
916 | ||
0e47c99d EB |
917 | static struct ctl_dir *find_subdir(struct ctl_dir *dir, |
918 | const char *name, int namelen) | |
1f87f0b5 | 919 | { |
7ec66d06 EB |
920 | struct ctl_table_header *head; |
921 | struct ctl_table *entry; | |
1f87f0b5 | 922 | |
0e47c99d | 923 | entry = find_entry(&head, dir, name, namelen); |
7ec66d06 EB |
924 | if (!entry) |
925 | return ERR_PTR(-ENOENT); | |
51f72f4a EB |
926 | if (!S_ISDIR(entry->mode)) |
927 | return ERR_PTR(-ENOTDIR); | |
928 | return container_of(head, struct ctl_dir, header); | |
7ec66d06 EB |
929 | } |
930 | ||
931 | static struct ctl_dir *new_dir(struct ctl_table_set *set, | |
0e47c99d | 932 | const char *name, int namelen) |
7ec66d06 EB |
933 | { |
934 | struct ctl_table *table; | |
935 | struct ctl_dir *new; | |
ac13ac6f | 936 | struct ctl_node *node; |
7ec66d06 | 937 | char *new_name; |
1f87f0b5 | 938 | |
ac13ac6f EB |
939 | new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + |
940 | sizeof(struct ctl_table)*2 + namelen + 1, | |
941 | GFP_KERNEL); | |
7ec66d06 | 942 | if (!new) |
1f87f0b5 EB |
943 | return NULL; |
944 | ||
ac13ac6f EB |
945 | node = (struct ctl_node *)(new + 1); |
946 | table = (struct ctl_table *)(node + 1); | |
7ec66d06 EB |
947 | new_name = (char *)(table + 2); |
948 | memcpy(new_name, name, namelen); | |
949 | new_name[namelen] = '\0'; | |
950 | table[0].procname = new_name; | |
951 | table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; | |
ac13ac6f | 952 | init_header(&new->header, set->dir.header.root, set, node, table); |
7ec66d06 EB |
953 | |
954 | return new; | |
1f87f0b5 EB |
955 | } |
956 | ||
60f126d9 EB |
957 | /** |
958 | * get_subdir - find or create a subdir with the specified name. | |
959 | * @dir: Directory to create the subdirectory in | |
960 | * @name: The name of the subdirectory to find or create | |
961 | * @namelen: The length of name | |
962 | * | |
963 | * Takes a directory with an elevated reference count so we know that | |
964 | * if we drop the lock the directory will not go away. Upon success | |
965 | * the reference is moved from @dir to the returned subdirectory. | |
966 | * Upon error an error code is returned and the reference on @dir is | |
967 | * simply dropped. | |
968 | */ | |
0e47c99d EB |
969 | static struct ctl_dir *get_subdir(struct ctl_dir *dir, |
970 | const char *name, int namelen) | |
1f87f0b5 | 971 | { |
0e47c99d | 972 | struct ctl_table_set *set = dir->header.set; |
7ec66d06 | 973 | struct ctl_dir *subdir, *new = NULL; |
0eb97f38 | 974 | int err; |
1f87f0b5 | 975 | |
7ec66d06 | 976 | spin_lock(&sysctl_lock); |
0e47c99d | 977 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
978 | if (!IS_ERR(subdir)) |
979 | goto found; | |
980 | if (PTR_ERR(subdir) != -ENOENT) | |
981 | goto failed; | |
982 | ||
983 | spin_unlock(&sysctl_lock); | |
984 | new = new_dir(set, name, namelen); | |
985 | spin_lock(&sysctl_lock); | |
986 | subdir = ERR_PTR(-ENOMEM); | |
987 | if (!new) | |
988 | goto failed; | |
989 | ||
60f126d9 | 990 | /* Was the subdir added while we dropped the lock? */ |
0e47c99d | 991 | subdir = find_subdir(dir, name, namelen); |
7ec66d06 EB |
992 | if (!IS_ERR(subdir)) |
993 | goto found; | |
994 | if (PTR_ERR(subdir) != -ENOENT) | |
995 | goto failed; | |
996 | ||
60f126d9 | 997 | /* Nope. Use the our freshly made directory entry. */ |
0eb97f38 EB |
998 | err = insert_header(dir, &new->header); |
999 | subdir = ERR_PTR(err); | |
1000 | if (err) | |
0e47c99d | 1001 | goto failed; |
7ec66d06 EB |
1002 | subdir = new; |
1003 | found: | |
1004 | subdir->header.nreg++; | |
1005 | failed: | |
a1c83681 | 1006 | if (IS_ERR(subdir)) { |
87ebdc00 | 1007 | pr_err("sysctl could not get directory: "); |
6980128f | 1008 | sysctl_print_dir(dir); |
87ebdc00 | 1009 | pr_cont("/%*.*s %ld\n", |
7ec66d06 | 1010 | namelen, namelen, name, PTR_ERR(subdir)); |
1f87f0b5 | 1011 | } |
7ec66d06 EB |
1012 | drop_sysctl_table(&dir->header); |
1013 | if (new) | |
1014 | drop_sysctl_table(&new->header); | |
1015 | spin_unlock(&sysctl_lock); | |
1016 | return subdir; | |
1f87f0b5 EB |
1017 | } |
1018 | ||
0e47c99d EB |
1019 | static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) |
1020 | { | |
1021 | struct ctl_dir *parent; | |
1022 | const char *procname; | |
1023 | if (!dir->header.parent) | |
1024 | return &set->dir; | |
1025 | parent = xlate_dir(set, dir->header.parent); | |
1026 | if (IS_ERR(parent)) | |
1027 | return parent; | |
1028 | procname = dir->header.ctl_table[0].procname; | |
1029 | return find_subdir(parent, procname, strlen(procname)); | |
1030 | } | |
1031 | ||
1032 | static int sysctl_follow_link(struct ctl_table_header **phead, | |
13bcc6a2 | 1033 | struct ctl_table **pentry) |
0e47c99d EB |
1034 | { |
1035 | struct ctl_table_header *head; | |
1036 | struct ctl_table_root *root; | |
1037 | struct ctl_table_set *set; | |
1038 | struct ctl_table *entry; | |
1039 | struct ctl_dir *dir; | |
1040 | int ret; | |
1041 | ||
0e47c99d EB |
1042 | ret = 0; |
1043 | spin_lock(&sysctl_lock); | |
1044 | root = (*pentry)->data; | |
13bcc6a2 | 1045 | set = lookup_header_set(root); |
0e47c99d EB |
1046 | dir = xlate_dir(set, (*phead)->parent); |
1047 | if (IS_ERR(dir)) | |
1048 | ret = PTR_ERR(dir); | |
1049 | else { | |
1050 | const char *procname = (*pentry)->procname; | |
1051 | head = NULL; | |
1052 | entry = find_entry(&head, dir, procname, strlen(procname)); | |
1053 | ret = -ENOENT; | |
1054 | if (entry && use_table(head)) { | |
1055 | unuse_table(*phead); | |
1056 | *phead = head; | |
1057 | *pentry = entry; | |
1058 | ret = 0; | |
1059 | } | |
1060 | } | |
1061 | ||
1062 | spin_unlock(&sysctl_lock); | |
1063 | return ret; | |
1064 | } | |
1065 | ||
7c60c48f | 1066 | static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) |
1f87f0b5 | 1067 | { |
7c60c48f EB |
1068 | struct va_format vaf; |
1069 | va_list args; | |
1f87f0b5 | 1070 | |
7c60c48f EB |
1071 | va_start(args, fmt); |
1072 | vaf.fmt = fmt; | |
1073 | vaf.va = &args; | |
1074 | ||
87ebdc00 AM |
1075 | pr_err("sysctl table check failed: %s/%s %pV\n", |
1076 | path, table->procname, &vaf); | |
1f87f0b5 | 1077 | |
7c60c48f EB |
1078 | va_end(args); |
1079 | return -EINVAL; | |
1f87f0b5 EB |
1080 | } |
1081 | ||
4f2fec00 LR |
1082 | static int sysctl_check_table_array(const char *path, struct ctl_table *table) |
1083 | { | |
1084 | int err = 0; | |
1085 | ||
61d9b56a LR |
1086 | if ((table->proc_handler == proc_douintvec) || |
1087 | (table->proc_handler == proc_douintvec_minmax)) { | |
4f2fec00 | 1088 | if (table->maxlen != sizeof(unsigned int)) |
64a11f3d | 1089 | err |= sysctl_err(path, table, "array not allowed"); |
4f2fec00 LR |
1090 | } |
1091 | ||
1092 | return err; | |
1093 | } | |
1094 | ||
7c60c48f | 1095 | static int sysctl_check_table(const char *path, struct ctl_table *table) |
1f87f0b5 | 1096 | { |
7c60c48f | 1097 | int err = 0; |
1f87f0b5 | 1098 | for (; table->procname; table++) { |
1f87f0b5 | 1099 | if (table->child) |
89c5b53b | 1100 | err |= sysctl_err(path, table, "Not a file"); |
7c60c48f EB |
1101 | |
1102 | if ((table->proc_handler == proc_dostring) || | |
1103 | (table->proc_handler == proc_dointvec) || | |
1680a386 | 1104 | (table->proc_handler == proc_douintvec) || |
61d9b56a | 1105 | (table->proc_handler == proc_douintvec_minmax) || |
7c60c48f EB |
1106 | (table->proc_handler == proc_dointvec_minmax) || |
1107 | (table->proc_handler == proc_dointvec_jiffies) || | |
1108 | (table->proc_handler == proc_dointvec_userhz_jiffies) || | |
1109 | (table->proc_handler == proc_dointvec_ms_jiffies) || | |
1110 | (table->proc_handler == proc_doulongvec_minmax) || | |
1111 | (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { | |
1112 | if (!table->data) | |
89c5b53b | 1113 | err |= sysctl_err(path, table, "No data"); |
7c60c48f | 1114 | if (!table->maxlen) |
89c5b53b | 1115 | err |= sysctl_err(path, table, "No maxlen"); |
4f2fec00 LR |
1116 | else |
1117 | err |= sysctl_check_table_array(path, table); | |
7c60c48f EB |
1118 | } |
1119 | if (!table->proc_handler) | |
89c5b53b | 1120 | err |= sysctl_err(path, table, "No proc_handler"); |
7c60c48f EB |
1121 | |
1122 | if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) | |
89c5b53b | 1123 | err |= sysctl_err(path, table, "bogus .mode 0%o", |
7c60c48f | 1124 | table->mode); |
1f87f0b5 | 1125 | } |
7c60c48f | 1126 | return err; |
1f87f0b5 | 1127 | } |
1f87f0b5 | 1128 | |
0e47c99d EB |
1129 | static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, |
1130 | struct ctl_table_root *link_root) | |
1131 | { | |
1132 | struct ctl_table *link_table, *entry, *link; | |
1133 | struct ctl_table_header *links; | |
ac13ac6f | 1134 | struct ctl_node *node; |
0e47c99d EB |
1135 | char *link_name; |
1136 | int nr_entries, name_bytes; | |
1137 | ||
1138 | name_bytes = 0; | |
1139 | nr_entries = 0; | |
1140 | for (entry = table; entry->procname; entry++) { | |
1141 | nr_entries++; | |
1142 | name_bytes += strlen(entry->procname) + 1; | |
1143 | } | |
1144 | ||
1145 | links = kzalloc(sizeof(struct ctl_table_header) + | |
ac13ac6f | 1146 | sizeof(struct ctl_node)*nr_entries + |
0e47c99d EB |
1147 | sizeof(struct ctl_table)*(nr_entries + 1) + |
1148 | name_bytes, | |
1149 | GFP_KERNEL); | |
1150 | ||
1151 | if (!links) | |
1152 | return NULL; | |
1153 | ||
ac13ac6f EB |
1154 | node = (struct ctl_node *)(links + 1); |
1155 | link_table = (struct ctl_table *)(node + nr_entries); | |
0e47c99d EB |
1156 | link_name = (char *)&link_table[nr_entries + 1]; |
1157 | ||
1158 | for (link = link_table, entry = table; entry->procname; link++, entry++) { | |
1159 | int len = strlen(entry->procname) + 1; | |
1160 | memcpy(link_name, entry->procname, len); | |
1161 | link->procname = link_name; | |
1162 | link->mode = S_IFLNK|S_IRWXUGO; | |
1163 | link->data = link_root; | |
1164 | link_name += len; | |
1165 | } | |
ac13ac6f | 1166 | init_header(links, dir->header.root, dir->header.set, node, link_table); |
0e47c99d EB |
1167 | links->nreg = nr_entries; |
1168 | ||
1169 | return links; | |
1170 | } | |
1171 | ||
1172 | static bool get_links(struct ctl_dir *dir, | |
1173 | struct ctl_table *table, struct ctl_table_root *link_root) | |
1174 | { | |
1175 | struct ctl_table_header *head; | |
1176 | struct ctl_table *entry, *link; | |
1177 | ||
1178 | /* Are there links available for every entry in table? */ | |
1179 | for (entry = table; entry->procname; entry++) { | |
1180 | const char *procname = entry->procname; | |
1181 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1182 | if (!link) | |
1183 | return false; | |
1184 | if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) | |
1185 | continue; | |
1186 | if (S_ISLNK(link->mode) && (link->data == link_root)) | |
1187 | continue; | |
1188 | return false; | |
1189 | } | |
1190 | ||
1191 | /* The checks passed. Increase the registration count on the links */ | |
1192 | for (entry = table; entry->procname; entry++) { | |
1193 | const char *procname = entry->procname; | |
1194 | link = find_entry(&head, dir, procname, strlen(procname)); | |
1195 | head->nreg++; | |
1196 | } | |
1197 | return true; | |
1198 | } | |
1199 | ||
1200 | static int insert_links(struct ctl_table_header *head) | |
1201 | { | |
1202 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1203 | struct ctl_dir *core_parent = NULL; | |
1204 | struct ctl_table_header *links; | |
1205 | int err; | |
1206 | ||
1207 | if (head->set == root_set) | |
1208 | return 0; | |
1209 | ||
1210 | core_parent = xlate_dir(root_set, head->parent); | |
1211 | if (IS_ERR(core_parent)) | |
1212 | return 0; | |
1213 | ||
1214 | if (get_links(core_parent, head->ctl_table, head->root)) | |
1215 | return 0; | |
1216 | ||
1217 | core_parent->header.nreg++; | |
1218 | spin_unlock(&sysctl_lock); | |
1219 | ||
1220 | links = new_links(core_parent, head->ctl_table, head->root); | |
1221 | ||
1222 | spin_lock(&sysctl_lock); | |
1223 | err = -ENOMEM; | |
1224 | if (!links) | |
1225 | goto out; | |
1226 | ||
1227 | err = 0; | |
1228 | if (get_links(core_parent, head->ctl_table, head->root)) { | |
1229 | kfree(links); | |
1230 | goto out; | |
1231 | } | |
1232 | ||
1233 | err = insert_header(core_parent, links); | |
1234 | if (err) | |
1235 | kfree(links); | |
1236 | out: | |
1237 | drop_sysctl_table(&core_parent->header); | |
1238 | return err; | |
1239 | } | |
1240 | ||
1f87f0b5 | 1241 | /** |
f728019b | 1242 | * __register_sysctl_table - register a leaf sysctl table |
60a47a2e | 1243 | * @set: Sysctl tree to register on |
1f87f0b5 EB |
1244 | * @path: The path to the directory the sysctl table is in. |
1245 | * @table: the top-level table structure | |
1246 | * | |
1247 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1248 | * array. A completely 0 filled entry terminates the table. | |
1249 | * | |
1250 | * The members of the &struct ctl_table structure are used as follows: | |
1251 | * | |
1252 | * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not | |
1253 | * enter a sysctl file | |
1254 | * | |
1255 | * data - a pointer to data for use by proc_handler | |
1256 | * | |
1257 | * maxlen - the maximum size in bytes of the data | |
1258 | * | |
f728019b | 1259 | * mode - the file permissions for the /proc/sys file |
1f87f0b5 | 1260 | * |
f728019b | 1261 | * child - must be %NULL. |
1f87f0b5 EB |
1262 | * |
1263 | * proc_handler - the text handler routine (described below) | |
1264 | * | |
1f87f0b5 EB |
1265 | * extra1, extra2 - extra pointers usable by the proc handler routines |
1266 | * | |
1267 | * Leaf nodes in the sysctl tree will be represented by a single file | |
1268 | * under /proc; non-leaf nodes will be represented by directories. | |
1269 | * | |
f728019b EB |
1270 | * There must be a proc_handler routine for any terminal nodes. |
1271 | * Several default handlers are available to cover common cases - | |
1f87f0b5 EB |
1272 | * |
1273 | * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), | |
1274 | * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), | |
1275 | * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() | |
1276 | * | |
1277 | * It is the handler's job to read the input buffer from user memory | |
1278 | * and process it. The handler should return 0 on success. | |
1279 | * | |
1280 | * This routine returns %NULL on a failure to register, and a pointer | |
1281 | * to the table header on success. | |
1282 | */ | |
6e9d5164 | 1283 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 1284 | struct ctl_table_set *set, |
6e9d5164 | 1285 | const char *path, struct ctl_table *table) |
1f87f0b5 | 1286 | { |
60a47a2e | 1287 | struct ctl_table_root *root = set->dir.header.root; |
1f87f0b5 | 1288 | struct ctl_table_header *header; |
6e9d5164 | 1289 | const char *name, *nextname; |
7ec66d06 | 1290 | struct ctl_dir *dir; |
ac13ac6f EB |
1291 | struct ctl_table *entry; |
1292 | struct ctl_node *node; | |
1293 | int nr_entries = 0; | |
1294 | ||
1295 | for (entry = table; entry->procname; entry++) | |
1296 | nr_entries++; | |
1f87f0b5 | 1297 | |
ac13ac6f EB |
1298 | header = kzalloc(sizeof(struct ctl_table_header) + |
1299 | sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); | |
1f87f0b5 EB |
1300 | if (!header) |
1301 | return NULL; | |
1302 | ||
ac13ac6f EB |
1303 | node = (struct ctl_node *)(header + 1); |
1304 | init_header(header, root, set, node, table); | |
7ec66d06 EB |
1305 | if (sysctl_check_table(path, table)) |
1306 | goto fail; | |
1307 | ||
1308 | spin_lock(&sysctl_lock); | |
0e47c99d | 1309 | dir = &set->dir; |
60f126d9 | 1310 | /* Reference moved down the diretory tree get_subdir */ |
7ec66d06 EB |
1311 | dir->header.nreg++; |
1312 | spin_unlock(&sysctl_lock); | |
1f87f0b5 | 1313 | |
7ec66d06 | 1314 | /* Find the directory for the ctl_table */ |
6e9d5164 EB |
1315 | for (name = path; name; name = nextname) { |
1316 | int namelen; | |
1317 | nextname = strchr(name, '/'); | |
1318 | if (nextname) { | |
1319 | namelen = nextname - name; | |
1320 | nextname++; | |
1321 | } else { | |
1322 | namelen = strlen(name); | |
1323 | } | |
1324 | if (namelen == 0) | |
1325 | continue; | |
1f87f0b5 | 1326 | |
0e47c99d | 1327 | dir = get_subdir(dir, name, namelen); |
7ec66d06 EB |
1328 | if (IS_ERR(dir)) |
1329 | goto fail; | |
1f87f0b5 | 1330 | } |
0e47c99d | 1331 | |
1f87f0b5 | 1332 | spin_lock(&sysctl_lock); |
0e47c99d | 1333 | if (insert_header(dir, header)) |
7ec66d06 | 1334 | goto fail_put_dir_locked; |
0e47c99d | 1335 | |
7ec66d06 | 1336 | drop_sysctl_table(&dir->header); |
1f87f0b5 EB |
1337 | spin_unlock(&sysctl_lock); |
1338 | ||
1339 | return header; | |
0e47c99d | 1340 | |
7ec66d06 EB |
1341 | fail_put_dir_locked: |
1342 | drop_sysctl_table(&dir->header); | |
7c60c48f EB |
1343 | spin_unlock(&sysctl_lock); |
1344 | fail: | |
1345 | kfree(header); | |
1346 | dump_stack(); | |
1347 | return NULL; | |
1f87f0b5 EB |
1348 | } |
1349 | ||
fea478d4 EB |
1350 | /** |
1351 | * register_sysctl - register a sysctl table | |
1352 | * @path: The path to the directory the sysctl table is in. | |
1353 | * @table: the table structure | |
1354 | * | |
1355 | * Register a sysctl table. @table should be a filled in ctl_table | |
1356 | * array. A completely 0 filled entry terminates the table. | |
1357 | * | |
1358 | * See __register_sysctl_table for more details. | |
1359 | */ | |
1360 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) | |
1361 | { | |
1362 | return __register_sysctl_table(&sysctl_table_root.default_set, | |
1363 | path, table); | |
1364 | } | |
1365 | EXPORT_SYMBOL(register_sysctl); | |
1366 | ||
6e9d5164 EB |
1367 | static char *append_path(const char *path, char *pos, const char *name) |
1368 | { | |
1369 | int namelen; | |
1370 | namelen = strlen(name); | |
1371 | if (((pos - path) + namelen + 2) >= PATH_MAX) | |
1372 | return NULL; | |
1373 | memcpy(pos, name, namelen); | |
1374 | pos[namelen] = '/'; | |
1375 | pos[namelen + 1] = '\0'; | |
1376 | pos += namelen + 1; | |
1377 | return pos; | |
1378 | } | |
1379 | ||
f728019b EB |
1380 | static int count_subheaders(struct ctl_table *table) |
1381 | { | |
1382 | int has_files = 0; | |
1383 | int nr_subheaders = 0; | |
1384 | struct ctl_table *entry; | |
1385 | ||
1386 | /* special case: no directory and empty directory */ | |
1387 | if (!table || !table->procname) | |
1388 | return 1; | |
1389 | ||
1390 | for (entry = table; entry->procname; entry++) { | |
1391 | if (entry->child) | |
1392 | nr_subheaders += count_subheaders(entry->child); | |
1393 | else | |
1394 | has_files = 1; | |
1395 | } | |
1396 | return nr_subheaders + has_files; | |
1397 | } | |
1398 | ||
1399 | static int register_leaf_sysctl_tables(const char *path, char *pos, | |
60a47a2e | 1400 | struct ctl_table_header ***subheader, struct ctl_table_set *set, |
f728019b EB |
1401 | struct ctl_table *table) |
1402 | { | |
1403 | struct ctl_table *ctl_table_arg = NULL; | |
1404 | struct ctl_table *entry, *files; | |
1405 | int nr_files = 0; | |
1406 | int nr_dirs = 0; | |
1407 | int err = -ENOMEM; | |
1408 | ||
1409 | for (entry = table; entry->procname; entry++) { | |
1410 | if (entry->child) | |
1411 | nr_dirs++; | |
1412 | else | |
1413 | nr_files++; | |
1414 | } | |
1415 | ||
1416 | files = table; | |
1417 | /* If there are mixed files and directories we need a new table */ | |
1418 | if (nr_dirs && nr_files) { | |
1419 | struct ctl_table *new; | |
6396bb22 | 1420 | files = kcalloc(nr_files + 1, sizeof(struct ctl_table), |
f728019b EB |
1421 | GFP_KERNEL); |
1422 | if (!files) | |
1423 | goto out; | |
1424 | ||
1425 | ctl_table_arg = files; | |
1426 | for (new = files, entry = table; entry->procname; entry++) { | |
1427 | if (entry->child) | |
1428 | continue; | |
1429 | *new = *entry; | |
1430 | new++; | |
1431 | } | |
1432 | } | |
1433 | ||
1434 | /* Register everything except a directory full of subdirectories */ | |
1435 | if (nr_files || !nr_dirs) { | |
1436 | struct ctl_table_header *header; | |
60a47a2e | 1437 | header = __register_sysctl_table(set, path, files); |
f728019b EB |
1438 | if (!header) { |
1439 | kfree(ctl_table_arg); | |
1440 | goto out; | |
1441 | } | |
1442 | ||
1443 | /* Remember if we need to free the file table */ | |
1444 | header->ctl_table_arg = ctl_table_arg; | |
1445 | **subheader = header; | |
1446 | (*subheader)++; | |
1447 | } | |
1448 | ||
1449 | /* Recurse into the subdirectories. */ | |
1450 | for (entry = table; entry->procname; entry++) { | |
1451 | char *child_pos; | |
1452 | ||
1453 | if (!entry->child) | |
1454 | continue; | |
1455 | ||
1456 | err = -ENAMETOOLONG; | |
1457 | child_pos = append_path(path, pos, entry->procname); | |
1458 | if (!child_pos) | |
1459 | goto out; | |
1460 | ||
1461 | err = register_leaf_sysctl_tables(path, child_pos, subheader, | |
60a47a2e | 1462 | set, entry->child); |
f728019b EB |
1463 | pos[0] = '\0'; |
1464 | if (err) | |
1465 | goto out; | |
1466 | } | |
1467 | err = 0; | |
1468 | out: | |
1469 | /* On failure our caller will unregister all registered subheaders */ | |
1470 | return err; | |
1471 | } | |
1472 | ||
6e9d5164 EB |
1473 | /** |
1474 | * __register_sysctl_paths - register a sysctl table hierarchy | |
60a47a2e | 1475 | * @set: Sysctl tree to register on |
6e9d5164 EB |
1476 | * @path: The path to the directory the sysctl table is in. |
1477 | * @table: the top-level table structure | |
1478 | * | |
1479 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1480 | * array. A completely 0 filled entry terminates the table. | |
1481 | * | |
1482 | * See __register_sysctl_table for more details. | |
1483 | */ | |
1484 | struct ctl_table_header *__register_sysctl_paths( | |
60a47a2e | 1485 | struct ctl_table_set *set, |
6e9d5164 EB |
1486 | const struct ctl_path *path, struct ctl_table *table) |
1487 | { | |
ec6a5266 | 1488 | struct ctl_table *ctl_table_arg = table; |
f728019b EB |
1489 | int nr_subheaders = count_subheaders(table); |
1490 | struct ctl_table_header *header = NULL, **subheaders, **subheader; | |
6e9d5164 EB |
1491 | const struct ctl_path *component; |
1492 | char *new_path, *pos; | |
1493 | ||
1494 | pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); | |
1495 | if (!new_path) | |
1496 | return NULL; | |
1497 | ||
1498 | pos[0] = '\0'; | |
1499 | for (component = path; component->procname; component++) { | |
1500 | pos = append_path(new_path, pos, component->procname); | |
1501 | if (!pos) | |
1502 | goto out; | |
1503 | } | |
ec6a5266 EB |
1504 | while (table->procname && table->child && !table[1].procname) { |
1505 | pos = append_path(new_path, pos, table->procname); | |
1506 | if (!pos) | |
1507 | goto out; | |
1508 | table = table->child; | |
1509 | } | |
f728019b | 1510 | if (nr_subheaders == 1) { |
60a47a2e | 1511 | header = __register_sysctl_table(set, new_path, table); |
f728019b EB |
1512 | if (header) |
1513 | header->ctl_table_arg = ctl_table_arg; | |
1514 | } else { | |
1515 | header = kzalloc(sizeof(*header) + | |
1516 | sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); | |
1517 | if (!header) | |
1518 | goto out; | |
1519 | ||
1520 | subheaders = (struct ctl_table_header **) (header + 1); | |
1521 | subheader = subheaders; | |
ec6a5266 | 1522 | header->ctl_table_arg = ctl_table_arg; |
f728019b EB |
1523 | |
1524 | if (register_leaf_sysctl_tables(new_path, pos, &subheader, | |
60a47a2e | 1525 | set, table)) |
f728019b EB |
1526 | goto err_register_leaves; |
1527 | } | |
1528 | ||
6e9d5164 EB |
1529 | out: |
1530 | kfree(new_path); | |
1531 | return header; | |
f728019b EB |
1532 | |
1533 | err_register_leaves: | |
1534 | while (subheader > subheaders) { | |
1535 | struct ctl_table_header *subh = *(--subheader); | |
1536 | struct ctl_table *table = subh->ctl_table_arg; | |
1537 | unregister_sysctl_table(subh); | |
1538 | kfree(table); | |
1539 | } | |
1540 | kfree(header); | |
1541 | header = NULL; | |
1542 | goto out; | |
6e9d5164 EB |
1543 | } |
1544 | ||
1f87f0b5 EB |
1545 | /** |
1546 | * register_sysctl_table_path - register a sysctl table hierarchy | |
1547 | * @path: The path to the directory the sysctl table is in. | |
1548 | * @table: the top-level table structure | |
1549 | * | |
1550 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1551 | * array. A completely 0 filled entry terminates the table. | |
1552 | * | |
1553 | * See __register_sysctl_paths for more details. | |
1554 | */ | |
1555 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, | |
1556 | struct ctl_table *table) | |
1557 | { | |
60a47a2e | 1558 | return __register_sysctl_paths(&sysctl_table_root.default_set, |
1f87f0b5 EB |
1559 | path, table); |
1560 | } | |
1561 | EXPORT_SYMBOL(register_sysctl_paths); | |
1562 | ||
1563 | /** | |
1564 | * register_sysctl_table - register a sysctl table hierarchy | |
1565 | * @table: the top-level table structure | |
1566 | * | |
1567 | * Register a sysctl table hierarchy. @table should be a filled in ctl_table | |
1568 | * array. A completely 0 filled entry terminates the table. | |
1569 | * | |
1570 | * See register_sysctl_paths for more details. | |
1571 | */ | |
1572 | struct ctl_table_header *register_sysctl_table(struct ctl_table *table) | |
1573 | { | |
1574 | static const struct ctl_path null_path[] = { {} }; | |
1575 | ||
1576 | return register_sysctl_paths(null_path, table); | |
1577 | } | |
1578 | EXPORT_SYMBOL(register_sysctl_table); | |
1579 | ||
0e47c99d EB |
1580 | static void put_links(struct ctl_table_header *header) |
1581 | { | |
1582 | struct ctl_table_set *root_set = &sysctl_table_root.default_set; | |
1583 | struct ctl_table_root *root = header->root; | |
1584 | struct ctl_dir *parent = header->parent; | |
1585 | struct ctl_dir *core_parent; | |
1586 | struct ctl_table *entry; | |
1587 | ||
1588 | if (header->set == root_set) | |
1589 | return; | |
1590 | ||
1591 | core_parent = xlate_dir(root_set, parent); | |
1592 | if (IS_ERR(core_parent)) | |
1593 | return; | |
1594 | ||
1595 | for (entry = header->ctl_table; entry->procname; entry++) { | |
1596 | struct ctl_table_header *link_head; | |
1597 | struct ctl_table *link; | |
1598 | const char *name = entry->procname; | |
1599 | ||
1600 | link = find_entry(&link_head, core_parent, name, strlen(name)); | |
1601 | if (link && | |
1602 | ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || | |
1603 | (S_ISLNK(link->mode) && (link->data == root)))) { | |
1604 | drop_sysctl_table(link_head); | |
1605 | } | |
1606 | else { | |
87ebdc00 | 1607 | pr_err("sysctl link missing during unregister: "); |
0e47c99d | 1608 | sysctl_print_dir(parent); |
87ebdc00 | 1609 | pr_cont("/%s\n", name); |
0e47c99d EB |
1610 | } |
1611 | } | |
1612 | } | |
1613 | ||
938aaa4f EB |
1614 | static void drop_sysctl_table(struct ctl_table_header *header) |
1615 | { | |
7ec66d06 EB |
1616 | struct ctl_dir *parent = header->parent; |
1617 | ||
938aaa4f EB |
1618 | if (--header->nreg) |
1619 | return; | |
1620 | ||
89189557 | 1621 | if (parent) { |
23da9588 | 1622 | put_links(header); |
89189557 Y |
1623 | start_unregistering(header); |
1624 | } | |
1625 | ||
938aaa4f EB |
1626 | if (!--header->count) |
1627 | kfree_rcu(header, rcu); | |
7ec66d06 EB |
1628 | |
1629 | if (parent) | |
1630 | drop_sysctl_table(&parent->header); | |
938aaa4f EB |
1631 | } |
1632 | ||
1f87f0b5 EB |
1633 | /** |
1634 | * unregister_sysctl_table - unregister a sysctl table hierarchy | |
1635 | * @header: the header returned from register_sysctl_table | |
1636 | * | |
1637 | * Unregisters the sysctl table and all children. proc entries may not | |
1638 | * actually be removed until they are no longer used by anyone. | |
1639 | */ | |
1640 | void unregister_sysctl_table(struct ctl_table_header * header) | |
1641 | { | |
f728019b | 1642 | int nr_subheaders; |
1f87f0b5 EB |
1643 | might_sleep(); |
1644 | ||
1645 | if (header == NULL) | |
1646 | return; | |
1647 | ||
f728019b EB |
1648 | nr_subheaders = count_subheaders(header->ctl_table_arg); |
1649 | if (unlikely(nr_subheaders > 1)) { | |
1650 | struct ctl_table_header **subheaders; | |
1651 | int i; | |
1652 | ||
1653 | subheaders = (struct ctl_table_header **)(header + 1); | |
1654 | for (i = nr_subheaders -1; i >= 0; i--) { | |
1655 | struct ctl_table_header *subh = subheaders[i]; | |
1656 | struct ctl_table *table = subh->ctl_table_arg; | |
1657 | unregister_sysctl_table(subh); | |
1658 | kfree(table); | |
1659 | } | |
1660 | kfree(header); | |
1661 | return; | |
1662 | } | |
1663 | ||
1f87f0b5 | 1664 | spin_lock(&sysctl_lock); |
938aaa4f | 1665 | drop_sysctl_table(header); |
1f87f0b5 EB |
1666 | spin_unlock(&sysctl_lock); |
1667 | } | |
1668 | EXPORT_SYMBOL(unregister_sysctl_table); | |
1669 | ||
0e47c99d | 1670 | void setup_sysctl_set(struct ctl_table_set *set, |
9eb47c26 | 1671 | struct ctl_table_root *root, |
1f87f0b5 EB |
1672 | int (*is_seen)(struct ctl_table_set *)) |
1673 | { | |
1347440d | 1674 | memset(set, 0, sizeof(*set)); |
0e47c99d | 1675 | set->is_seen = is_seen; |
ac13ac6f | 1676 | init_header(&set->dir.header, root, set, NULL, root_table); |
1f87f0b5 EB |
1677 | } |
1678 | ||
97324cd8 EB |
1679 | void retire_sysctl_set(struct ctl_table_set *set) |
1680 | { | |
ac13ac6f | 1681 | WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); |
97324cd8 | 1682 | } |
1f87f0b5 | 1683 | |
1e0edd3f | 1684 | int __init proc_sys_init(void) |
77b14db5 | 1685 | { |
e1675231 AD |
1686 | struct proc_dir_entry *proc_sys_root; |
1687 | ||
77b14db5 | 1688 | proc_sys_root = proc_mkdir("sys", NULL); |
9043476f | 1689 | proc_sys_root->proc_iops = &proc_sys_dir_operations; |
d56c0d45 | 1690 | proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations; |
77b14db5 | 1691 | proc_sys_root->nlink = 0; |
de4e83bd EB |
1692 | |
1693 | return sysctl_init(); | |
77b14db5 | 1694 | } |