aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/audit_tree.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/audit_tree.c')
-rw-r--r--kernel/audit_tree.c234
1 files changed, 130 insertions, 104 deletions
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 46a57b57a335..a164600dd82e 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -1,5 +1,5 @@
1#include "audit.h" 1#include "audit.h"
2#include <linux/inotify.h> 2#include <linux/fsnotify_backend.h>
3#include <linux/namei.h> 3#include <linux/namei.h>
4#include <linux/mount.h> 4#include <linux/mount.h>
5#include <linux/kthread.h> 5#include <linux/kthread.h>
@@ -22,7 +22,7 @@ struct audit_tree {
22 22
23struct audit_chunk { 23struct audit_chunk {
24 struct list_head hash; 24 struct list_head hash;
25 struct inotify_watch watch; 25 struct fsnotify_mark_entry mark;
26 struct list_head trees; /* with root here */ 26 struct list_head trees; /* with root here */
27 int dead; 27 int dead;
28 int count; 28 int count;
@@ -59,7 +59,7 @@ static LIST_HEAD(prune_list);
59 * tree is refcounted; one reference for "some rules on rules_list refer to 59 * tree is refcounted; one reference for "some rules on rules_list refer to
60 * it", one for each chunk with pointer to it. 60 * it", one for each chunk with pointer to it.
61 * 61 *
62 * chunk is refcounted by embedded inotify_watch + .refs (non-zero refcount 62 * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount
63 * of watch contributes 1 to .refs). 63 * of watch contributes 1 to .refs).
64 * 64 *
65 * node.index allows to get from node.list to containing chunk. 65 * node.index allows to get from node.list to containing chunk.
@@ -68,7 +68,7 @@ static LIST_HEAD(prune_list);
68 * that makes a difference. Some. 68 * that makes a difference. Some.
69 */ 69 */
70 70
71static struct inotify_handle *rtree_ih; 71static struct fsnotify_group *audit_tree_group;
72 72
73static struct audit_tree *alloc_tree(const char *s) 73static struct audit_tree *alloc_tree(const char *s)
74{ 74{
@@ -111,29 +111,6 @@ const char *audit_tree_path(struct audit_tree *tree)
111 return tree->pathname; 111 return tree->pathname;
112} 112}
113 113
114static struct audit_chunk *alloc_chunk(int count)
115{
116 struct audit_chunk *chunk;
117 size_t size;
118 int i;
119
120 size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
121 chunk = kzalloc(size, GFP_KERNEL);
122 if (!chunk)
123 return NULL;
124
125 INIT_LIST_HEAD(&chunk->hash);
126 INIT_LIST_HEAD(&chunk->trees);
127 chunk->count = count;
128 atomic_long_set(&chunk->refs, 1);
129 for (i = 0; i < count; i++) {
130 INIT_LIST_HEAD(&chunk->owners[i].list);
131 chunk->owners[i].index = i;
132 }
133 inotify_init_watch(&chunk->watch);
134 return chunk;
135}
136
137static void free_chunk(struct audit_chunk *chunk) 114static void free_chunk(struct audit_chunk *chunk)
138{ 115{
139 int i; 116 int i;
@@ -157,6 +134,35 @@ static void __put_chunk(struct rcu_head *rcu)
157 audit_put_chunk(chunk); 134 audit_put_chunk(chunk);
158} 135}
159 136
137static void audit_tree_destroy_watch(struct fsnotify_mark_entry *entry)
138{
139 struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
140 call_rcu(&chunk->head, __put_chunk);
141}
142
143static struct audit_chunk *alloc_chunk(int count)
144{
145 struct audit_chunk *chunk;
146 size_t size;
147 int i;
148
149 size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
150 chunk = kzalloc(size, GFP_KERNEL);
151 if (!chunk)
152 return NULL;
153
154 INIT_LIST_HEAD(&chunk->hash);
155 INIT_LIST_HEAD(&chunk->trees);
156 chunk->count = count;
157 atomic_long_set(&chunk->refs, 1);
158 for (i = 0; i < count; i++) {
159 INIT_LIST_HEAD(&chunk->owners[i].list);
160 chunk->owners[i].index = i;
161 }
162 fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch);
163 return chunk;
164}
165
160enum {HASH_SIZE = 128}; 166enum {HASH_SIZE = 128};
161static struct list_head chunk_hash_heads[HASH_SIZE]; 167static struct list_head chunk_hash_heads[HASH_SIZE];
162static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); 168static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
@@ -167,10 +173,15 @@ static inline struct list_head *chunk_hash(const struct inode *inode)
167 return chunk_hash_heads + n % HASH_SIZE; 173 return chunk_hash_heads + n % HASH_SIZE;
168} 174}
169 175
170/* hash_lock is held by caller */ 176/* hash_lock & entry->lock is held by caller */
171static void insert_hash(struct audit_chunk *chunk) 177static void insert_hash(struct audit_chunk *chunk)
172{ 178{
173 struct list_head *list = chunk_hash(chunk->watch.inode); 179 struct fsnotify_mark_entry *entry = &chunk->mark;
180 struct list_head *list;
181
182 if (!entry->inode)
183 return;
184 list = chunk_hash(entry->inode);
174 list_add_rcu(&chunk->hash, list); 185 list_add_rcu(&chunk->hash, list);
175} 186}
176 187
@@ -181,7 +192,8 @@ struct audit_chunk *audit_tree_lookup(const struct inode *inode)
181 struct audit_chunk *p; 192 struct audit_chunk *p;
182 193
183 list_for_each_entry_rcu(p, list, hash) { 194 list_for_each_entry_rcu(p, list, hash) {
184 if (p->watch.inode == inode) { 195 /* mark.inode may have gone NULL, but who cares? */
196 if (p->mark.inode == inode) {
185 atomic_long_inc(&p->refs); 197 atomic_long_inc(&p->refs);
186 return p; 198 return p;
187 } 199 }
@@ -210,38 +222,19 @@ static struct audit_chunk *find_chunk(struct node *p)
210static void untag_chunk(struct node *p) 222static void untag_chunk(struct node *p)
211{ 223{
212 struct audit_chunk *chunk = find_chunk(p); 224 struct audit_chunk *chunk = find_chunk(p);
225 struct fsnotify_mark_entry *entry = &chunk->mark;
213 struct audit_chunk *new; 226 struct audit_chunk *new;
214 struct audit_tree *owner; 227 struct audit_tree *owner;
215 int size = chunk->count - 1; 228 int size = chunk->count - 1;
216 int i, j; 229 int i, j;
217 230
218 if (!pin_inotify_watch(&chunk->watch)) { 231 fsnotify_get_mark(entry);
219 /*
220 * Filesystem is shutting down; all watches are getting
221 * evicted, just take it off the node list for this
222 * tree and let the eviction logics take care of the
223 * rest.
224 */
225 owner = p->owner;
226 if (owner->root == chunk) {
227 list_del_init(&owner->same_root);
228 owner->root = NULL;
229 }
230 list_del_init(&p->list);
231 p->owner = NULL;
232 put_tree(owner);
233 return;
234 }
235 232
236 spin_unlock(&hash_lock); 233 spin_unlock(&hash_lock);
237 234
238 /* 235 spin_lock(&entry->lock);
239 * pin_inotify_watch() succeeded, so the watch won't go away 236 if (chunk->dead || !entry->inode) {
240 * from under us. 237 spin_unlock(&entry->lock);
241 */
242 mutex_lock(&chunk->watch.inode->inotify_mutex);
243 if (chunk->dead) {
244 mutex_unlock(&chunk->watch.inode->inotify_mutex);
245 goto out; 238 goto out;
246 } 239 }
247 240
@@ -256,16 +249,17 @@ static void untag_chunk(struct node *p)
256 list_del_init(&p->list); 249 list_del_init(&p->list);
257 list_del_rcu(&chunk->hash); 250 list_del_rcu(&chunk->hash);
258 spin_unlock(&hash_lock); 251 spin_unlock(&hash_lock);
259 inotify_evict_watch(&chunk->watch); 252 spin_unlock(&entry->lock);
260 mutex_unlock(&chunk->watch.inode->inotify_mutex); 253 fsnotify_destroy_mark_by_entry(entry);
261 put_inotify_watch(&chunk->watch); 254 fsnotify_put_mark(entry);
262 goto out; 255 goto out;
263 } 256 }
264 257
265 new = alloc_chunk(size); 258 new = alloc_chunk(size);
266 if (!new) 259 if (!new)
267 goto Fallback; 260 goto Fallback;
268 if (inotify_clone_watch(&chunk->watch, &new->watch) < 0) { 261 fsnotify_duplicate_mark(&new->mark, entry);
262 if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, 1)) {
269 free_chunk(new); 263 free_chunk(new);
270 goto Fallback; 264 goto Fallback;
271 } 265 }
@@ -298,9 +292,9 @@ static void untag_chunk(struct node *p)
298 list_for_each_entry(owner, &new->trees, same_root) 292 list_for_each_entry(owner, &new->trees, same_root)
299 owner->root = new; 293 owner->root = new;
300 spin_unlock(&hash_lock); 294 spin_unlock(&hash_lock);
301 inotify_evict_watch(&chunk->watch); 295 spin_unlock(&entry->lock);
302 mutex_unlock(&chunk->watch.inode->inotify_mutex); 296 fsnotify_destroy_mark_by_entry(entry);
303 put_inotify_watch(&chunk->watch); 297 fsnotify_put_mark(entry);
304 goto out; 298 goto out;
305 299
306Fallback: 300Fallback:
@@ -314,31 +308,33 @@ Fallback:
314 p->owner = NULL; 308 p->owner = NULL;
315 put_tree(owner); 309 put_tree(owner);
316 spin_unlock(&hash_lock); 310 spin_unlock(&hash_lock);
317 mutex_unlock(&chunk->watch.inode->inotify_mutex); 311 spin_unlock(&entry->lock);
318out: 312out:
319 unpin_inotify_watch(&chunk->watch); 313 fsnotify_put_mark(entry);
320 spin_lock(&hash_lock); 314 spin_lock(&hash_lock);
321} 315}
322 316
323static int create_chunk(struct inode *inode, struct audit_tree *tree) 317static int create_chunk(struct inode *inode, struct audit_tree *tree)
324{ 318{
319 struct fsnotify_mark_entry *entry;
325 struct audit_chunk *chunk = alloc_chunk(1); 320 struct audit_chunk *chunk = alloc_chunk(1);
326 if (!chunk) 321 if (!chunk)
327 return -ENOMEM; 322 return -ENOMEM;
328 323
329 if (inotify_add_watch(rtree_ih, &chunk->watch, inode, IN_IGNORED | IN_DELETE_SELF) < 0) { 324 entry = &chunk->mark;
325 if (fsnotify_add_mark(entry, audit_tree_group, inode, 0)) {
330 free_chunk(chunk); 326 free_chunk(chunk);
331 return -ENOSPC; 327 return -ENOSPC;
332 } 328 }
333 329
334 mutex_lock(&inode->inotify_mutex); 330 spin_lock(&entry->lock);
335 spin_lock(&hash_lock); 331 spin_lock(&hash_lock);
336 if (tree->goner) { 332 if (tree->goner) {
337 spin_unlock(&hash_lock); 333 spin_unlock(&hash_lock);
338 chunk->dead = 1; 334 chunk->dead = 1;
339 inotify_evict_watch(&chunk->watch); 335 spin_unlock(&entry->lock);
340 mutex_unlock(&inode->inotify_mutex); 336 fsnotify_destroy_mark_by_entry(entry);
341 put_inotify_watch(&chunk->watch); 337 fsnotify_put_mark(entry);
342 return 0; 338 return 0;
343 } 339 }
344 chunk->owners[0].index = (1U << 31); 340 chunk->owners[0].index = (1U << 31);
@@ -351,30 +347,33 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree)
351 } 347 }
352 insert_hash(chunk); 348 insert_hash(chunk);
353 spin_unlock(&hash_lock); 349 spin_unlock(&hash_lock);
354 mutex_unlock(&inode->inotify_mutex); 350 spin_unlock(&entry->lock);
355 return 0; 351 return 0;
356} 352}
357 353
358/* the first tagged inode becomes root of tree */ 354/* the first tagged inode becomes root of tree */
359static int tag_chunk(struct inode *inode, struct audit_tree *tree) 355static int tag_chunk(struct inode *inode, struct audit_tree *tree)
360{ 356{
361 struct inotify_watch *watch; 357 struct fsnotify_mark_entry *old_entry, *chunk_entry;
362 struct audit_tree *owner; 358 struct audit_tree *owner;
363 struct audit_chunk *chunk, *old; 359 struct audit_chunk *chunk, *old;
364 struct node *p; 360 struct node *p;
365 int n; 361 int n;
366 362
367 if (inotify_find_watch(rtree_ih, inode, &watch) < 0) 363 spin_lock(&inode->i_lock);
364 old_entry = fsnotify_find_mark_entry(audit_tree_group, inode);
365 spin_unlock(&inode->i_lock);
366 if (!old_entry)
368 return create_chunk(inode, tree); 367 return create_chunk(inode, tree);
369 368
370 old = container_of(watch, struct audit_chunk, watch); 369 old = container_of(old_entry, struct audit_chunk, mark);
371 370
372 /* are we already there? */ 371 /* are we already there? */
373 spin_lock(&hash_lock); 372 spin_lock(&hash_lock);
374 for (n = 0; n < old->count; n++) { 373 for (n = 0; n < old->count; n++) {
375 if (old->owners[n].owner == tree) { 374 if (old->owners[n].owner == tree) {
376 spin_unlock(&hash_lock); 375 spin_unlock(&hash_lock);
377 put_inotify_watch(&old->watch); 376 fsnotify_put_mark(old_entry);
378 return 0; 377 return 0;
379 } 378 }
380 } 379 }
@@ -382,25 +381,44 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
382 381
383 chunk = alloc_chunk(old->count + 1); 382 chunk = alloc_chunk(old->count + 1);
384 if (!chunk) { 383 if (!chunk) {
385 put_inotify_watch(&old->watch); 384 fsnotify_put_mark(old_entry);
386 return -ENOMEM; 385 return -ENOMEM;
387 } 386 }
388 387
389 mutex_lock(&inode->inotify_mutex); 388 chunk_entry = &chunk->mark;
390 if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) { 389
391 mutex_unlock(&inode->inotify_mutex); 390 spin_lock(&old_entry->lock);
392 put_inotify_watch(&old->watch); 391 if (!old_entry->inode) {
392 /* old_entry is being shot, lets just lie */
393 spin_unlock(&old_entry->lock);
394 fsnotify_put_mark(old_entry);
393 free_chunk(chunk); 395 free_chunk(chunk);
396 return -ENOENT;
397 }
398
399 fsnotify_duplicate_mark(chunk_entry, old_entry);
400 if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, 1)) {
401 spin_unlock(&old_entry->lock);
402 free_chunk(chunk);
403 fsnotify_put_mark(old_entry);
394 return -ENOSPC; 404 return -ENOSPC;
395 } 405 }
406
407 /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */
408 spin_lock(&chunk_entry->lock);
396 spin_lock(&hash_lock); 409 spin_lock(&hash_lock);
410
411 /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */
397 if (tree->goner) { 412 if (tree->goner) {
398 spin_unlock(&hash_lock); 413 spin_unlock(&hash_lock);
399 chunk->dead = 1; 414 chunk->dead = 1;
400 inotify_evict_watch(&chunk->watch); 415 spin_unlock(&chunk_entry->lock);
401 mutex_unlock(&inode->inotify_mutex); 416 spin_unlock(&old_entry->lock);
402 put_inotify_watch(&old->watch); 417
403 put_inotify_watch(&chunk->watch); 418 fsnotify_destroy_mark_by_entry(chunk_entry);
419
420 fsnotify_put_mark(chunk_entry);
421 fsnotify_put_mark(old_entry);
404 return 0; 422 return 0;
405 } 423 }
406 list_replace_init(&old->trees, &chunk->trees); 424 list_replace_init(&old->trees, &chunk->trees);
@@ -426,10 +444,11 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
426 list_add(&tree->same_root, &chunk->trees); 444 list_add(&tree->same_root, &chunk->trees);
427 } 445 }
428 spin_unlock(&hash_lock); 446 spin_unlock(&hash_lock);
429 inotify_evict_watch(&old->watch); 447 spin_unlock(&chunk_entry->lock);
430 mutex_unlock(&inode->inotify_mutex); 448 spin_unlock(&old_entry->lock);
431 put_inotify_watch(&old->watch); /* pair to inotify_find_watch */ 449 fsnotify_destroy_mark_by_entry(old_entry);
432 put_inotify_watch(&old->watch); /* and kill it */ 450 fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
451 fsnotify_put_mark(old_entry); /* and kill it */
433 return 0; 452 return 0;
434} 453}
435 454
@@ -584,7 +603,9 @@ void audit_trim_trees(void)
584 603
585 spin_lock(&hash_lock); 604 spin_lock(&hash_lock);
586 list_for_each_entry(node, &tree->chunks, list) { 605 list_for_each_entry(node, &tree->chunks, list) {
587 struct inode *inode = find_chunk(node)->watch.inode; 606 struct audit_chunk *chunk = find_chunk(node);
607 /* this could be NULL if the watch is dieing else where... */
608 struct inode *inode = chunk->mark.inode;
588 node->index |= 1U<<31; 609 node->index |= 1U<<31;
589 if (iterate_mounts(compare_root, inode, root_mnt)) 610 if (iterate_mounts(compare_root, inode, root_mnt))
590 node->index &= ~(1U<<31); 611 node->index &= ~(1U<<31);
@@ -846,7 +867,6 @@ void audit_kill_trees(struct list_head *list)
846 * Here comes the stuff asynchronous to auditctl operations 867 * Here comes the stuff asynchronous to auditctl operations
847 */ 868 */
848 869
849/* inode->inotify_mutex is locked */
850static void evict_chunk(struct audit_chunk *chunk) 870static void evict_chunk(struct audit_chunk *chunk)
851{ 871{
852 struct audit_tree *owner; 872 struct audit_tree *owner;
@@ -885,35 +905,41 @@ static void evict_chunk(struct audit_chunk *chunk)
885 mutex_unlock(&audit_filter_mutex); 905 mutex_unlock(&audit_filter_mutex);
886} 906}
887 907
888static void handle_event(struct inotify_watch *watch, u32 wd, u32 mask, 908static int audit_tree_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
889 u32 cookie, const char *dname, struct inode *inode)
890{ 909{
891 struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); 910 BUG();
911 return -EOPNOTSUPP;
912}
892 913
893 if (mask & IN_IGNORED) { 914static void audit_tree_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
894 evict_chunk(chunk); 915{
895 put_inotify_watch(watch); 916 struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
896 } 917
918 evict_chunk(chunk);
919 fsnotify_put_mark(entry);
897} 920}
898 921
899static void destroy_watch(struct inotify_watch *watch) 922static bool audit_tree_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
900{ 923{
901 struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); 924 return 0;
902 call_rcu(&chunk->head, __put_chunk);
903} 925}
904 926
905static const struct inotify_operations rtree_inotify_ops = { 927static const struct fsnotify_ops audit_tree_ops = {
906 .handle_event = handle_event, 928 .handle_event = audit_tree_handle_event,
907 .destroy_watch = destroy_watch, 929 .should_send_event = audit_tree_send_event,
930 .free_group_priv = NULL,
931 .free_event_priv = NULL,
932 .freeing_mark = audit_tree_freeing_mark,
908}; 933};
909 934
910static int __init audit_tree_init(void) 935static int __init audit_tree_init(void)
911{ 936{
912 int i; 937 int i;
913 938
914 rtree_ih = inotify_init(&rtree_inotify_ops); 939 audit_tree_group = fsnotify_obtain_group(AUDIT_TREE_GROUP_NUM,
915 if (IS_ERR(rtree_ih)) 940 0, &audit_tree_ops);
916 audit_panic("cannot initialize inotify handle for rectree watches"); 941 if (IS_ERR(audit_tree_group))
942 audit_panic("cannot initialize fsnotify group for rectree watches");
917 943
918 for (i = 0; i < HASH_SIZE; i++) 944 for (i = 0; i < HASH_SIZE; i++)
919 INIT_LIST_HEAD(&chunk_hash_heads[i]); 945 INIT_LIST_HEAD(&chunk_hash_heads[i]);