blob: 986a6a75686843f4a6afeed9b6492650db79d055 [file] [log] [blame]
Tetsuo Handa847b1732010-02-11 09:43:54 +09001/*
2 * security/tomoyo/gc.c
3 *
Tetsuo Handa0f2a55d2011-07-14 14:46:51 +09004 * Copyright (C) 2005-2011 NTT DATA CORPORATION
Tetsuo Handa847b1732010-02-11 09:43:54 +09005 */
6
7#include "common.h"
8#include <linux/kthread.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Tetsuo Handa847b1732010-02-11 09:43:54 +090010
Tetsuo Handaa427fd12011-09-25 17:51:06 +090011/**
12 * tomoyo_memory_free - Free memory for elements.
13 *
14 * @ptr: Pointer to allocated memory.
15 *
16 * Returns nothing.
17 *
18 * Caller holds tomoyo_policy_lock mutex.
19 */
20static inline void tomoyo_memory_free(void *ptr)
21{
22 tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= ksize(ptr);
23 kfree(ptr);
24}
25
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090026/* The list for "struct tomoyo_io_buffer". */
27static LIST_HEAD(tomoyo_io_buffer_list);
28/* Lock for protecting tomoyo_io_buffer_list. */
29static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock);
30
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090031/**
32 * tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not.
33 *
34 * @element: Pointer to "struct list_head".
35 *
36 * Returns true if @element is used by /sys/kernel/security/tomoyo/ users,
37 * false otherwise.
38 */
39static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element)
40{
41 struct tomoyo_io_buffer *head;
42 bool in_use = false;
43
44 spin_lock(&tomoyo_io_buffer_list_lock);
45 list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
46 head->users++;
47 spin_unlock(&tomoyo_io_buffer_list_lock);
Tetsuo Handaf9732ea2011-09-25 17:50:23 +090048 mutex_lock(&head->io_sem);
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090049 if (head->r.domain == element || head->r.group == element ||
50 head->r.acl == element || &head->w.domain->list == element)
51 in_use = true;
52 mutex_unlock(&head->io_sem);
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090053 spin_lock(&tomoyo_io_buffer_list_lock);
54 head->users--;
55 if (in_use)
56 break;
57 }
58 spin_unlock(&tomoyo_io_buffer_list_lock);
59 return in_use;
60}
61
62/**
63 * tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not.
64 *
65 * @string: String to check.
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090066 *
67 * Returns true if @string is used by /sys/kernel/security/tomoyo/ users,
68 * false otherwise.
69 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +090070static bool tomoyo_name_used_by_io_buffer(const char *string)
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090071{
72 struct tomoyo_io_buffer *head;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +090073 const size_t size = strlen(string) + 1;
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090074 bool in_use = false;
75
76 spin_lock(&tomoyo_io_buffer_list_lock);
77 list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
78 int i;
79 head->users++;
80 spin_unlock(&tomoyo_io_buffer_list_lock);
Tetsuo Handaf9732ea2011-09-25 17:50:23 +090081 mutex_lock(&head->io_sem);
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090082 for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) {
83 const char *w = head->r.w[i];
84 if (w < string || w > string + size)
85 continue;
86 in_use = true;
87 break;
88 }
89 mutex_unlock(&head->io_sem);
Tetsuo Handa2e503bb2011-06-26 23:20:55 +090090 spin_lock(&tomoyo_io_buffer_list_lock);
91 head->users--;
92 if (in_use)
93 break;
94 }
95 spin_unlock(&tomoyo_io_buffer_list_lock);
96 return in_use;
97}
98
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +090099/**
100 * tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control".
101 *
102 * @element: Pointer to "struct list_head".
103 *
104 * Returns nothing.
105 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900106static inline void tomoyo_del_transition_control(struct list_head *element)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900107{
Tetsuo Handa5448ec42010-06-21 11:14:39 +0900108 struct tomoyo_transition_control *ptr =
Tetsuo Handae79acf02010-06-16 16:31:50 +0900109 container_of(element, typeof(*ptr), head.list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900110 tomoyo_put_name(ptr->domainname);
111 tomoyo_put_name(ptr->program);
112}
113
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900114/**
115 * tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator".
116 *
117 * @element: Pointer to "struct list_head".
118 *
119 * Returns nothing.
120 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900121static inline void tomoyo_del_aggregator(struct list_head *element)
Tetsuo Handa10843072010-06-03 20:38:03 +0900122{
Tetsuo Handae2bf6902010-06-25 11:16:00 +0900123 struct tomoyo_aggregator *ptr =
Tetsuo Handae79acf02010-06-16 16:31:50 +0900124 container_of(element, typeof(*ptr), head.list);
Tetsuo Handa10843072010-06-03 20:38:03 +0900125 tomoyo_put_name(ptr->original_name);
126 tomoyo_put_name(ptr->aggregated_name);
127}
128
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900129/**
130 * tomoyo_del_manager - Delete members in "struct tomoyo_manager".
131 *
132 * @element: Pointer to "struct list_head".
133 *
134 * Returns nothing.
135 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900136static inline void tomoyo_del_manager(struct list_head *element)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900137{
Tetsuo Handae2bf6902010-06-25 11:16:00 +0900138 struct tomoyo_manager *ptr =
Tetsuo Handae79acf02010-06-16 16:31:50 +0900139 container_of(element, typeof(*ptr), head.list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900140 tomoyo_put_name(ptr->manager);
141}
142
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900143/**
144 * tomoyo_del_acl - Delete members in "struct tomoyo_acl_info".
145 *
146 * @element: Pointer to "struct list_head".
147 *
148 * Returns nothing.
149 */
Tetsuo Handae79acf02010-06-16 16:31:50 +0900150static void tomoyo_del_acl(struct list_head *element)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900151{
Tetsuo Handae79acf02010-06-16 16:31:50 +0900152 struct tomoyo_acl_info *acl =
153 container_of(element, typeof(*acl), list);
Tetsuo Handa2066a362011-07-08 13:21:37 +0900154 tomoyo_put_condition(acl->cond);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900155 switch (acl->type) {
Tetsuo Handa7ef61232010-02-16 08:03:30 +0900156 case TOMOYO_TYPE_PATH_ACL:
Tetsuo Handa847b1732010-02-11 09:43:54 +0900157 {
Tetsuo Handa7ef61232010-02-16 08:03:30 +0900158 struct tomoyo_path_acl *entry
Tetsuo Handa847b1732010-02-11 09:43:54 +0900159 = container_of(acl, typeof(*entry), head);
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900160 tomoyo_put_name_union(&entry->name);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900161 }
162 break;
Tetsuo Handa7ef61232010-02-16 08:03:30 +0900163 case TOMOYO_TYPE_PATH2_ACL:
Tetsuo Handa847b1732010-02-11 09:43:54 +0900164 {
Tetsuo Handa7ef61232010-02-16 08:03:30 +0900165 struct tomoyo_path2_acl *entry
Tetsuo Handa847b1732010-02-11 09:43:54 +0900166 = container_of(acl, typeof(*entry), head);
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900167 tomoyo_put_name_union(&entry->name1);
168 tomoyo_put_name_union(&entry->name2);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900169 }
170 break;
Tetsuo Handaa1f9bb62010-05-17 10:09:15 +0900171 case TOMOYO_TYPE_PATH_NUMBER_ACL:
172 {
173 struct tomoyo_path_number_acl *entry
174 = container_of(acl, typeof(*entry), head);
175 tomoyo_put_name_union(&entry->name);
176 tomoyo_put_number_union(&entry->number);
177 }
178 break;
Tetsuo Handa75093152010-06-16 16:23:55 +0900179 case TOMOYO_TYPE_MKDEV_ACL:
Tetsuo Handaa1f9bb62010-05-17 10:09:15 +0900180 {
Tetsuo Handa75093152010-06-16 16:23:55 +0900181 struct tomoyo_mkdev_acl *entry
Tetsuo Handaa1f9bb62010-05-17 10:09:15 +0900182 = container_of(acl, typeof(*entry), head);
183 tomoyo_put_name_union(&entry->name);
184 tomoyo_put_number_union(&entry->mode);
185 tomoyo_put_number_union(&entry->major);
186 tomoyo_put_number_union(&entry->minor);
187 }
188 break;
Tetsuo Handa2106ccd2010-05-17 10:10:31 +0900189 case TOMOYO_TYPE_MOUNT_ACL:
190 {
191 struct tomoyo_mount_acl *entry
192 = container_of(acl, typeof(*entry), head);
193 tomoyo_put_name_union(&entry->dev_name);
194 tomoyo_put_name_union(&entry->dir_name);
195 tomoyo_put_name_union(&entry->fs_type);
196 tomoyo_put_number_union(&entry->flags);
197 }
198 break;
Tetsuo Handad58e0da2011-09-10 15:22:48 +0900199 case TOMOYO_TYPE_ENV_ACL:
200 {
201 struct tomoyo_env_acl *entry =
202 container_of(acl, typeof(*entry), head);
203
204 tomoyo_put_name(entry->env);
205 }
206 break;
Tetsuo Handa059d84d2011-09-10 15:23:54 +0900207 case TOMOYO_TYPE_INET_ACL:
208 {
209 struct tomoyo_inet_acl *entry =
210 container_of(acl, typeof(*entry), head);
211
212 tomoyo_put_group(entry->address.group);
213 tomoyo_put_number_union(&entry->port);
214 }
215 break;
216 case TOMOYO_TYPE_UNIX_ACL:
217 {
218 struct tomoyo_unix_acl *entry =
219 container_of(acl, typeof(*entry), head);
220
221 tomoyo_put_name_union(&entry->name);
222 }
223 break;
Tetsuo Handa545a7262011-10-11 14:06:41 +0900224 case TOMOYO_TYPE_MANUAL_TASK_ACL:
225 {
226 struct tomoyo_task_acl *entry =
227 container_of(acl, typeof(*entry), head);
228 tomoyo_put_name(entry->domainname);
229 }
230 break;
Tetsuo Handa847b1732010-02-11 09:43:54 +0900231 }
232}
233
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900234/**
235 * tomoyo_del_domain - Delete members in "struct tomoyo_domain_info".
236 *
237 * @element: Pointer to "struct list_head".
238 *
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900239 * Returns nothing.
Tetsuo Handaa427fd12011-09-25 17:51:06 +0900240 *
241 * Caller holds tomoyo_policy_lock mutex.
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900242 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900243static inline void tomoyo_del_domain(struct list_head *element)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900244{
Tetsuo Handae79acf02010-06-16 16:31:50 +0900245 struct tomoyo_domain_info *domain =
246 container_of(element, typeof(*domain), list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900247 struct tomoyo_acl_info *acl;
248 struct tomoyo_acl_info *tmp;
249 /*
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900250 * Since this domain is referenced from neither
251 * "struct tomoyo_io_buffer" nor "struct cred"->security, we can delete
252 * elements without checking for is_deleted flag.
Tetsuo Handa847b1732010-02-11 09:43:54 +0900253 */
Tetsuo Handa847b1732010-02-11 09:43:54 +0900254 list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) {
Tetsuo Handae79acf02010-06-16 16:31:50 +0900255 tomoyo_del_acl(&acl->list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900256 tomoyo_memory_free(acl);
257 }
258 tomoyo_put_name(domain->domainname);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900259}
260
Tetsuo Handa2066a362011-07-08 13:21:37 +0900261/**
262 * tomoyo_del_condition - Delete members in "struct tomoyo_condition".
263 *
264 * @element: Pointer to "struct list_head".
265 *
266 * Returns nothing.
267 */
268void tomoyo_del_condition(struct list_head *element)
269{
270 struct tomoyo_condition *cond = container_of(element, typeof(*cond),
271 head.list);
272 const u16 condc = cond->condc;
273 const u16 numbers_count = cond->numbers_count;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900274 const u16 names_count = cond->names_count;
Tetsuo Handa5b636852011-07-08 13:24:54 +0900275 const u16 argc = cond->argc;
276 const u16 envc = cond->envc;
Tetsuo Handa2066a362011-07-08 13:21:37 +0900277 unsigned int i;
278 const struct tomoyo_condition_element *condp
279 = (const struct tomoyo_condition_element *) (cond + 1);
280 struct tomoyo_number_union *numbers_p
281 = (struct tomoyo_number_union *) (condp + condc);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900282 struct tomoyo_name_union *names_p
283 = (struct tomoyo_name_union *) (numbers_p + numbers_count);
Tetsuo Handa5b636852011-07-08 13:24:54 +0900284 const struct tomoyo_argv *argv
285 = (const struct tomoyo_argv *) (names_p + names_count);
286 const struct tomoyo_envp *envp
287 = (const struct tomoyo_envp *) (argv + argc);
Tetsuo Handa2066a362011-07-08 13:21:37 +0900288 for (i = 0; i < numbers_count; i++)
289 tomoyo_put_number_union(numbers_p++);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900290 for (i = 0; i < names_count; i++)
291 tomoyo_put_name_union(names_p++);
Tetsuo Handa5b636852011-07-08 13:24:54 +0900292 for (i = 0; i < argc; argv++, i++)
293 tomoyo_put_name(argv->value);
294 for (i = 0; i < envc; envp++, i++) {
295 tomoyo_put_name(envp->name);
296 tomoyo_put_name(envp->value);
297 }
Tetsuo Handa2066a362011-07-08 13:21:37 +0900298}
Tetsuo Handa847b1732010-02-11 09:43:54 +0900299
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900300/**
301 * tomoyo_del_name - Delete members in "struct tomoyo_name".
302 *
303 * @element: Pointer to "struct list_head".
304 *
305 * Returns nothing.
306 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900307static inline void tomoyo_del_name(struct list_head *element)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900308{
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900309 /* Nothing to do. */
Tetsuo Handa847b1732010-02-11 09:43:54 +0900310}
311
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900312/**
313 * tomoyo_del_path_group - Delete members in "struct tomoyo_path_group".
314 *
315 * @element: Pointer to "struct list_head".
316 *
317 * Returns nothing.
318 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900319static inline void tomoyo_del_path_group(struct list_head *element)
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900320{
Tetsuo Handaa98aa4d2010-06-17 16:52:29 +0900321 struct tomoyo_path_group *member =
Tetsuo Handae79acf02010-06-16 16:31:50 +0900322 container_of(element, typeof(*member), head.list);
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900323 tomoyo_put_name(member->member_name);
324}
325
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900326/**
327 * tomoyo_del_group - Delete "struct tomoyo_group".
328 *
329 * @element: Pointer to "struct list_head".
330 *
331 * Returns nothing.
332 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900333static inline void tomoyo_del_group(struct list_head *element)
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900334{
Tetsuo Handaa98aa4d2010-06-17 16:52:29 +0900335 struct tomoyo_group *group =
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900336 container_of(element, typeof(*group), head.list);
Tetsuo Handa7762fbf2010-05-10 17:30:26 +0900337 tomoyo_put_name(group->group_name);
338}
339
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900340/**
Tetsuo Handa059d84d2011-09-10 15:23:54 +0900341 * tomoyo_del_address_group - Delete members in "struct tomoyo_address_group".
342 *
343 * @element: Pointer to "struct list_head".
344 *
345 * Returns nothing.
346 */
347static inline void tomoyo_del_address_group(struct list_head *element)
348{
349 /* Nothing to do. */
350}
351
352/**
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900353 * tomoyo_del_number_group - Delete members in "struct tomoyo_number_group".
354 *
355 * @element: Pointer to "struct list_head".
356 *
357 * Returns nothing.
358 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900359static inline void tomoyo_del_number_group(struct list_head *element)
Tetsuo Handa4c3e9e22010-05-17 10:06:58 +0900360{
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900361 /* Nothing to do. */
362}
363
364/**
365 * tomoyo_try_to_gc - Try to kfree() an entry.
366 *
367 * @type: One of values in "enum tomoyo_policy_id".
368 * @element: Pointer to "struct list_head".
369 *
370 * Returns nothing.
371 *
372 * Caller holds tomoyo_policy_lock mutex.
373 */
374static void tomoyo_try_to_gc(const enum tomoyo_policy_id type,
375 struct list_head *element)
376{
377 /*
378 * __list_del_entry() guarantees that the list element became no longer
379 * reachable from the list which the element was originally on (e.g.
380 * tomoyo_domain_list). Also, synchronize_srcu() guarantees that the
381 * list element became no longer referenced by syscall users.
382 */
383 __list_del_entry(element);
384 mutex_unlock(&tomoyo_policy_lock);
385 synchronize_srcu(&tomoyo_ss);
386 /*
387 * However, there are two users which may still be using the list
388 * element. We need to defer until both users forget this element.
389 *
390 * Don't kfree() until "struct tomoyo_io_buffer"->r.{domain,group,acl}
391 * and "struct tomoyo_io_buffer"->w.domain forget this element.
392 */
393 if (tomoyo_struct_used_by_io_buffer(element))
394 goto reinject;
395 switch (type) {
396 case TOMOYO_ID_TRANSITION_CONTROL:
397 tomoyo_del_transition_control(element);
398 break;
399 case TOMOYO_ID_MANAGER:
400 tomoyo_del_manager(element);
401 break;
402 case TOMOYO_ID_AGGREGATOR:
403 tomoyo_del_aggregator(element);
404 break;
405 case TOMOYO_ID_GROUP:
406 tomoyo_del_group(element);
407 break;
408 case TOMOYO_ID_PATH_GROUP:
409 tomoyo_del_path_group(element);
410 break;
411 case TOMOYO_ID_ADDRESS_GROUP:
412 tomoyo_del_address_group(element);
413 break;
414 case TOMOYO_ID_NUMBER_GROUP:
415 tomoyo_del_number_group(element);
416 break;
417 case TOMOYO_ID_CONDITION:
418 tomoyo_del_condition(element);
419 break;
420 case TOMOYO_ID_NAME:
421 /*
422 * Don't kfree() until all "struct tomoyo_io_buffer"->r.w[]
423 * forget this element.
424 */
425 if (tomoyo_name_used_by_io_buffer
426 (container_of(element, typeof(struct tomoyo_name),
427 head.list)->entry.name))
428 goto reinject;
429 tomoyo_del_name(element);
430 break;
431 case TOMOYO_ID_ACL:
432 tomoyo_del_acl(element);
433 break;
434 case TOMOYO_ID_DOMAIN:
435 /*
436 * Don't kfree() until all "struct cred"->security forget this
437 * element.
438 */
439 if (atomic_read(&container_of
440 (element, typeof(struct tomoyo_domain_info),
441 list)->users))
442 goto reinject;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900443 break;
444 case TOMOYO_MAX_POLICY:
445 break;
446 }
447 mutex_lock(&tomoyo_policy_lock);
Tetsuo Handaa427fd12011-09-25 17:51:06 +0900448 if (type == TOMOYO_ID_DOMAIN)
449 tomoyo_del_domain(element);
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900450 tomoyo_memory_free(element);
451 return;
452reinject:
453 /*
454 * We can safely reinject this element here bacause
455 * (1) Appending list elements and removing list elements are protected
456 * by tomoyo_policy_lock mutex.
457 * (2) Only this function removes list elements and this function is
458 * exclusively executed by tomoyo_gc_mutex mutex.
459 * are true.
460 */
461 mutex_lock(&tomoyo_policy_lock);
462 list_add_rcu(element, element->prev);
Tetsuo Handa4c3e9e22010-05-17 10:06:58 +0900463}
464
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900465/**
466 * tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head".
467 *
468 * @id: One of values in "enum tomoyo_policy_id".
469 * @member_list: Pointer to "struct list_head".
470 *
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900471 * Returns nothing.
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900472 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900473static void tomoyo_collect_member(const enum tomoyo_policy_id id,
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900474 struct list_head *member_list)
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900475{
476 struct tomoyo_acl_head *member;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900477 struct tomoyo_acl_head *tmp;
478 list_for_each_entry_safe(member, tmp, member_list, list) {
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900479 if (!member->is_deleted)
480 continue;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900481 member->is_deleted = TOMOYO_GC_IN_PROGRESS;
482 tomoyo_try_to_gc(id, &member->list);
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900483 }
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900484}
485
Tetsuo Handa32997142011-06-26 23:19:28 +0900486/**
487 * tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info".
488 *
489 * @list: Pointer to "struct list_head".
490 *
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900491 * Returns nothing.
Tetsuo Handa32997142011-06-26 23:19:28 +0900492 */
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900493static void tomoyo_collect_acl(struct list_head *list)
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900494{
495 struct tomoyo_acl_info *acl;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900496 struct tomoyo_acl_info *tmp;
497 list_for_each_entry_safe(acl, tmp, list, list) {
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900498 if (!acl->is_deleted)
499 continue;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900500 acl->is_deleted = TOMOYO_GC_IN_PROGRESS;
501 tomoyo_try_to_gc(TOMOYO_ID_ACL, &acl->list);
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900502 }
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900503}
504
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900505/**
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900506 * tomoyo_collect_entry - Try to kfree() deleted elements.
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900507 *
508 * Returns nothing.
509 */
Tetsuo Handa847b1732010-02-11 09:43:54 +0900510static void tomoyo_collect_entry(void)
511{
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900512 int i;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900513 enum tomoyo_policy_id id;
514 struct tomoyo_policy_namespace *ns;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900515 mutex_lock(&tomoyo_policy_lock);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900516 {
517 struct tomoyo_domain_info *domain;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900518 struct tomoyo_domain_info *tmp;
519 list_for_each_entry_safe(domain, tmp, &tomoyo_domain_list,
520 list) {
521 tomoyo_collect_acl(&domain->acl_info_list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900522 if (!domain->is_deleted || atomic_read(&domain->users))
523 continue;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900524 tomoyo_try_to_gc(TOMOYO_ID_DOMAIN, &domain->list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900525 }
526 }
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900527 list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900528 for (id = 0; id < TOMOYO_MAX_POLICY; id++)
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900529 tomoyo_collect_member(id, &ns->policy_list[id]);
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900530 for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900531 tomoyo_collect_acl(&ns->acl_group[i]);
532 }
533 {
534 struct tomoyo_shared_acl_head *ptr;
535 struct tomoyo_shared_acl_head *tmp;
536 list_for_each_entry_safe(ptr, tmp, &tomoyo_condition_list,
537 list) {
538 if (atomic_read(&ptr->users) > 0)
539 continue;
540 atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
541 tomoyo_try_to_gc(TOMOYO_ID_CONDITION, &ptr->list);
542 }
543 }
544 list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900545 for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
546 struct list_head *list = &ns->group_list[i];
547 struct tomoyo_group *group;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900548 struct tomoyo_group *tmp;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900549 switch (i) {
550 case 0:
551 id = TOMOYO_ID_PATH_GROUP;
552 break;
Tetsuo Handa059d84d2011-09-10 15:23:54 +0900553 case 1:
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900554 id = TOMOYO_ID_NUMBER_GROUP;
555 break;
Tetsuo Handa059d84d2011-09-10 15:23:54 +0900556 default:
557 id = TOMOYO_ID_ADDRESS_GROUP;
558 break;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900559 }
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900560 list_for_each_entry_safe(group, tmp, list, head.list) {
561 tomoyo_collect_member(id, &group->member_list);
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900562 if (!list_empty(&group->member_list) ||
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900563 atomic_read(&group->head.users) > 0)
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900564 continue;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900565 atomic_set(&group->head.users,
566 TOMOYO_GC_IN_PROGRESS);
567 tomoyo_try_to_gc(TOMOYO_ID_GROUP,
568 &group->head.list);
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900569 }
570 }
571 }
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900572 for (i = 0; i < TOMOYO_MAX_HASH; i++) {
573 struct list_head *list = &tomoyo_name_list[i];
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900574 struct tomoyo_shared_acl_head *ptr;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900575 struct tomoyo_shared_acl_head *tmp;
576 list_for_each_entry_safe(ptr, tmp, list, list) {
577 if (atomic_read(&ptr->users) > 0)
Tetsuo Handad2f8b232010-06-15 10:10:37 +0900578 continue;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900579 atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
580 tomoyo_try_to_gc(TOMOYO_ID_NAME, &ptr->list);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900581 }
582 }
Tetsuo Handa29282382010-05-06 00:18:15 +0900583 mutex_unlock(&tomoyo_policy_lock);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900584}
585
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900586/**
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900587 * tomoyo_gc_thread - Garbage collector thread function.
588 *
589 * @unused: Unused.
590 *
Tetsuo Handa0df7e8b2011-06-26 23:16:36 +0900591 * Returns 0.
592 */
Tetsuo Handa847b1732010-02-11 09:43:54 +0900593static int tomoyo_gc_thread(void *unused)
594{
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900595 /* Garbage collector thread is exclusive. */
596 static DEFINE_MUTEX(tomoyo_gc_mutex);
597 if (!mutex_trylock(&tomoyo_gc_mutex))
598 goto out;
Tetsuo Handaf9732ea2011-09-25 17:50:23 +0900599 tomoyo_collect_entry();
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900600 {
601 struct tomoyo_io_buffer *head;
602 struct tomoyo_io_buffer *tmp;
603
604 spin_lock(&tomoyo_io_buffer_list_lock);
605 list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list,
606 list) {
607 if (head->users)
608 continue;
609 list_del(&head->list);
610 kfree(head->read_buf);
611 kfree(head->write_buf);
612 kfree(head);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900613 }
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900614 spin_unlock(&tomoyo_io_buffer_list_lock);
Tetsuo Handa847b1732010-02-11 09:43:54 +0900615 }
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900616 mutex_unlock(&tomoyo_gc_mutex);
617out:
618 /* This acts as do_exit(0). */
619 return 0;
Tetsuo Handa847b1732010-02-11 09:43:54 +0900620}
621
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900622/**
623 * tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users.
624 *
625 * @head: Pointer to "struct tomoyo_io_buffer".
626 * @is_register: True if register, false if unregister.
627 *
628 * Returns nothing.
629 */
630void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register)
Tetsuo Handa847b1732010-02-11 09:43:54 +0900631{
Tetsuo Handa2e503bb2011-06-26 23:20:55 +0900632 bool is_write = false;
633
634 spin_lock(&tomoyo_io_buffer_list_lock);
635 if (is_register) {
636 head->users = 1;
637 list_add(&head->list, &tomoyo_io_buffer_list);
638 } else {
639 is_write = head->write_buf != NULL;
640 if (!--head->users) {
641 list_del(&head->list);
642 kfree(head->read_buf);
643 kfree(head->write_buf);
644 kfree(head);
645 }
646 }
647 spin_unlock(&tomoyo_io_buffer_list_lock);
648 if (is_write) {
649 struct task_struct *task = kthread_create(tomoyo_gc_thread,
650 NULL,
651 "GC for TOMOYO");
652 if (!IS_ERR(task))
653 wake_up_process(task);
654 }
Tetsuo Handa847b1732010-02-11 09:43:54 +0900655}