1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/fsnotify_backend.h>
4 #include <linux/namei.h>
5 #include <linux/mount.h>
6 #include <linux/kthread.h>
7 #include <linux/refcount.h>
8 #include <linux/slab.h>
16 struct audit_chunk
*root
;
17 struct list_head chunks
;
18 struct list_head rules
;
19 struct list_head list
;
20 struct list_head same_root
;
26 struct list_head hash
;
28 struct fsnotify_mark
*mark
;
29 struct list_head trees
; /* with root here */
34 struct list_head list
;
35 struct audit_tree
*owner
;
36 unsigned index
; /* index; upper bit indicates 'will prune' */
40 struct audit_tree_mark
{
41 struct fsnotify_mark mark
;
42 struct audit_chunk
*chunk
;
45 static LIST_HEAD(tree_list
);
46 static LIST_HEAD(prune_list
);
47 static struct task_struct
*prune_thread
;
50 * One struct chunk is attached to each inode of interest through
51 * audit_tree_mark (fsnotify mark). We replace struct chunk on tagging /
52 * untagging, the mark is stable as long as there is chunk attached. The
53 * association between mark and chunk is protected by hash_lock and
54 * audit_tree_group->mark_mutex. Thus as long as we hold
55 * audit_tree_group->mark_mutex and check that the mark is alive by
56 * FSNOTIFY_MARK_FLAG_ATTACHED flag check, we are sure the mark points to
59 * Rules have pointer to struct audit_tree.
60 * Rules have struct list_head rlist forming a list of rules over
62 * References to struct chunk are collected at audit_inode{,_child}()
63 * time and used in AUDIT_TREE rule matching.
64 * These references are dropped at the same time we are calling
65 * audit_free_names(), etc.
67 * Cyclic lists galore:
68 * tree.chunks anchors chunk.owners[].list hash_lock
69 * tree.rules anchors rule.rlist audit_filter_mutex
70 * chunk.trees anchors tree.same_root hash_lock
71 * chunk.hash is a hash with middle bits of watch.inode as
72 * a hash function. RCU, hash_lock
74 * tree is refcounted; one reference for "some rules on rules_list refer to
75 * it", one for each chunk with pointer to it.
77 * chunk is refcounted by embedded .refs. Mark associated with the chunk holds
78 * one chunk reference. This reference is dropped either when a mark is going
79 * to be freed (corresponding inode goes away) or when chunk attached to the
80 * mark gets replaced. This reference must be dropped using
81 * audit_mark_put_chunk() to make sure the reference is dropped only after RCU
82 * grace period as it protects RCU readers of the hash table.
84 * node.index allows to get from node.list to containing chunk.
85 * MSB of that sucker is stolen to mark taggings that we might have to
86 * revert - several operations have very unpleasant cleanup logics and
87 * that makes a difference. Some.
90 static struct fsnotify_group
*audit_tree_group
;
91 static struct kmem_cache
*audit_tree_mark_cachep __read_mostly
;
93 static struct audit_tree
*alloc_tree(const char *s
)
95 struct audit_tree
*tree
;
97 tree
= kmalloc(sizeof(struct audit_tree
) + strlen(s
) + 1, GFP_KERNEL
);
99 refcount_set(&tree
->count
, 1);
101 INIT_LIST_HEAD(&tree
->chunks
);
102 INIT_LIST_HEAD(&tree
->rules
);
103 INIT_LIST_HEAD(&tree
->list
);
104 INIT_LIST_HEAD(&tree
->same_root
);
106 strcpy(tree
->pathname
, s
);
111 static inline void get_tree(struct audit_tree
*tree
)
113 refcount_inc(&tree
->count
);
116 static inline void put_tree(struct audit_tree
*tree
)
118 if (refcount_dec_and_test(&tree
->count
))
119 kfree_rcu(tree
, head
);
122 /* to avoid bringing the entire thing in audit.h */
123 const char *audit_tree_path(struct audit_tree
*tree
)
125 return tree
->pathname
;
128 static void free_chunk(struct audit_chunk
*chunk
)
132 for (i
= 0; i
< chunk
->count
; i
++) {
133 if (chunk
->owners
[i
].owner
)
134 put_tree(chunk
->owners
[i
].owner
);
139 void audit_put_chunk(struct audit_chunk
*chunk
)
141 if (atomic_long_dec_and_test(&chunk
->refs
))
145 static void __put_chunk(struct rcu_head
*rcu
)
147 struct audit_chunk
*chunk
= container_of(rcu
, struct audit_chunk
, head
);
148 audit_put_chunk(chunk
);
152 * Drop reference to the chunk that was held by the mark. This is the reference
153 * that gets dropped after we've removed the chunk from the hash table and we
154 * use it to make sure chunk cannot be freed before RCU grace period expires.
156 static void audit_mark_put_chunk(struct audit_chunk
*chunk
)
158 call_rcu(&chunk
->head
, __put_chunk
);
161 static inline struct audit_tree_mark
*audit_mark(struct fsnotify_mark
*mark
)
163 return container_of(mark
, struct audit_tree_mark
, mark
);
166 static struct audit_chunk
*mark_chunk(struct fsnotify_mark
*mark
)
168 return audit_mark(mark
)->chunk
;
171 static void audit_tree_destroy_watch(struct fsnotify_mark
*mark
)
173 kmem_cache_free(audit_tree_mark_cachep
, audit_mark(mark
));
176 static struct fsnotify_mark
*alloc_mark(void)
178 struct audit_tree_mark
*amark
;
180 amark
= kmem_cache_zalloc(audit_tree_mark_cachep
, GFP_KERNEL
);
183 fsnotify_init_mark(&amark
->mark
, audit_tree_group
);
184 amark
->mark
.mask
= FS_IN_IGNORED
;
188 static struct audit_chunk
*alloc_chunk(int count
)
190 struct audit_chunk
*chunk
;
193 chunk
= kzalloc(struct_size(chunk
, owners
, count
), GFP_KERNEL
);
197 INIT_LIST_HEAD(&chunk
->hash
);
198 INIT_LIST_HEAD(&chunk
->trees
);
199 chunk
->count
= count
;
200 atomic_long_set(&chunk
->refs
, 1);
201 for (i
= 0; i
< count
; i
++) {
202 INIT_LIST_HEAD(&chunk
->owners
[i
].list
);
203 chunk
->owners
[i
].index
= i
;
208 enum {HASH_SIZE
= 128};
209 static struct list_head chunk_hash_heads
[HASH_SIZE
];
210 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(hash_lock
);
212 /* Function to return search key in our hash from inode. */
213 static unsigned long inode_to_key(const struct inode
*inode
)
215 /* Use address pointed to by connector->obj as the key */
216 return (unsigned long)&inode
->i_fsnotify_marks
;
219 static inline struct list_head
*chunk_hash(unsigned long key
)
221 unsigned long n
= key
/ L1_CACHE_BYTES
;
222 return chunk_hash_heads
+ n
% HASH_SIZE
;
225 /* hash_lock & mark->group->mark_mutex is held by caller */
226 static void insert_hash(struct audit_chunk
*chunk
)
228 struct list_head
*list
;
231 * Make sure chunk is fully initialized before making it visible in the
232 * hash. Pairs with a data dependency barrier in READ_ONCE() in
233 * audit_tree_lookup().
236 WARN_ON_ONCE(!chunk
->key
);
237 list
= chunk_hash(chunk
->key
);
238 list_add_rcu(&chunk
->hash
, list
);
241 /* called under rcu_read_lock */
242 struct audit_chunk
*audit_tree_lookup(const struct inode
*inode
)
244 unsigned long key
= inode_to_key(inode
);
245 struct list_head
*list
= chunk_hash(key
);
246 struct audit_chunk
*p
;
248 list_for_each_entry_rcu(p
, list
, hash
) {
250 * We use a data dependency barrier in READ_ONCE() to make sure
251 * the chunk we see is fully initialized.
253 if (READ_ONCE(p
->key
) == key
) {
254 atomic_long_inc(&p
->refs
);
261 bool audit_tree_match(struct audit_chunk
*chunk
, struct audit_tree
*tree
)
264 for (n
= 0; n
< chunk
->count
; n
++)
265 if (chunk
->owners
[n
].owner
== tree
)
270 /* tagging and untagging inodes with trees */
272 static struct audit_chunk
*find_chunk(struct node
*p
)
274 int index
= p
->index
& ~(1U<<31);
276 return container_of(p
, struct audit_chunk
, owners
[0]);
279 static void replace_mark_chunk(struct fsnotify_mark
*mark
,
280 struct audit_chunk
*chunk
)
282 struct audit_chunk
*old
;
284 assert_spin_locked(&hash_lock
);
285 old
= mark_chunk(mark
);
286 audit_mark(mark
)->chunk
= chunk
;
293 static void replace_chunk(struct audit_chunk
*new, struct audit_chunk
*old
)
295 struct audit_tree
*owner
;
299 list_splice_init(&old
->trees
, &new->trees
);
300 list_for_each_entry(owner
, &new->trees
, same_root
)
302 for (i
= j
= 0; j
< old
->count
; i
++, j
++) {
303 if (!old
->owners
[j
].owner
) {
307 owner
= old
->owners
[j
].owner
;
308 new->owners
[i
].owner
= owner
;
309 new->owners
[i
].index
= old
->owners
[j
].index
- j
+ i
;
310 if (!owner
) /* result of earlier fallback */
313 list_replace_init(&old
->owners
[j
].list
, &new->owners
[i
].list
);
315 replace_mark_chunk(old
->mark
, new);
317 * Make sure chunk is fully initialized before making it visible in the
318 * hash. Pairs with a data dependency barrier in READ_ONCE() in
319 * audit_tree_lookup().
322 list_replace_rcu(&old
->hash
, &new->hash
);
325 static void remove_chunk_node(struct audit_chunk
*chunk
, struct node
*p
)
327 struct audit_tree
*owner
= p
->owner
;
329 if (owner
->root
== chunk
) {
330 list_del_init(&owner
->same_root
);
333 list_del_init(&p
->list
);
338 static int chunk_count_trees(struct audit_chunk
*chunk
)
343 for (i
= 0; i
< chunk
->count
; i
++)
344 if (chunk
->owners
[i
].owner
)
349 static void untag_chunk(struct audit_chunk
*chunk
, struct fsnotify_mark
*mark
)
351 struct audit_chunk
*new;
354 mutex_lock(&audit_tree_group
->mark_mutex
);
356 * mark_mutex stabilizes chunk attached to the mark so we can check
357 * whether it didn't change while we've dropped hash_lock.
359 if (!(mark
->flags
& FSNOTIFY_MARK_FLAG_ATTACHED
) ||
360 mark_chunk(mark
) != chunk
)
363 size
= chunk_count_trees(chunk
);
365 spin_lock(&hash_lock
);
366 list_del_init(&chunk
->trees
);
367 list_del_rcu(&chunk
->hash
);
368 replace_mark_chunk(mark
, NULL
);
369 spin_unlock(&hash_lock
);
370 fsnotify_detach_mark(mark
);
371 mutex_unlock(&audit_tree_group
->mark_mutex
);
372 audit_mark_put_chunk(chunk
);
373 fsnotify_free_mark(mark
);
377 new = alloc_chunk(size
);
381 spin_lock(&hash_lock
);
383 * This has to go last when updating chunk as once replace_chunk() is
384 * called, new RCU readers can see the new chunk.
386 replace_chunk(new, chunk
);
387 spin_unlock(&hash_lock
);
388 mutex_unlock(&audit_tree_group
->mark_mutex
);
389 audit_mark_put_chunk(chunk
);
393 mutex_unlock(&audit_tree_group
->mark_mutex
);
396 /* Call with group->mark_mutex held, releases it */
397 static int create_chunk(struct inode
*inode
, struct audit_tree
*tree
)
399 struct fsnotify_mark
*mark
;
400 struct audit_chunk
*chunk
= alloc_chunk(1);
403 mutex_unlock(&audit_tree_group
->mark_mutex
);
409 mutex_unlock(&audit_tree_group
->mark_mutex
);
414 if (fsnotify_add_inode_mark_locked(mark
, inode
, 0)) {
415 mutex_unlock(&audit_tree_group
->mark_mutex
);
416 fsnotify_put_mark(mark
);
421 spin_lock(&hash_lock
);
423 spin_unlock(&hash_lock
);
424 fsnotify_detach_mark(mark
);
425 mutex_unlock(&audit_tree_group
->mark_mutex
);
426 fsnotify_free_mark(mark
);
427 fsnotify_put_mark(mark
);
431 replace_mark_chunk(mark
, chunk
);
432 chunk
->owners
[0].index
= (1U << 31);
433 chunk
->owners
[0].owner
= tree
;
435 list_add(&chunk
->owners
[0].list
, &tree
->chunks
);
438 list_add(&tree
->same_root
, &chunk
->trees
);
440 chunk
->key
= inode_to_key(inode
);
442 * Inserting into the hash table has to go last as once we do that RCU
443 * readers can see the chunk.
446 spin_unlock(&hash_lock
);
447 mutex_unlock(&audit_tree_group
->mark_mutex
);
449 * Drop our initial reference. When mark we point to is getting freed,
450 * we get notification through ->freeing_mark callback and cleanup
451 * chunk pointing to this mark.
453 fsnotify_put_mark(mark
);
457 /* the first tagged inode becomes root of tree */
458 static int tag_chunk(struct inode
*inode
, struct audit_tree
*tree
)
460 struct fsnotify_mark
*mark
;
461 struct audit_chunk
*chunk
, *old
;
465 mutex_lock(&audit_tree_group
->mark_mutex
);
466 mark
= fsnotify_find_mark(&inode
->i_fsnotify_marks
, audit_tree_group
);
468 return create_chunk(inode
, tree
);
471 * Found mark is guaranteed to be attached and mark_mutex protects mark
472 * from getting detached and thus it makes sure there is chunk attached
475 /* are we already there? */
476 spin_lock(&hash_lock
);
477 old
= mark_chunk(mark
);
478 for (n
= 0; n
< old
->count
; n
++) {
479 if (old
->owners
[n
].owner
== tree
) {
480 spin_unlock(&hash_lock
);
481 mutex_unlock(&audit_tree_group
->mark_mutex
);
482 fsnotify_put_mark(mark
);
486 spin_unlock(&hash_lock
);
488 chunk
= alloc_chunk(old
->count
+ 1);
490 mutex_unlock(&audit_tree_group
->mark_mutex
);
491 fsnotify_put_mark(mark
);
495 spin_lock(&hash_lock
);
497 spin_unlock(&hash_lock
);
498 mutex_unlock(&audit_tree_group
->mark_mutex
);
499 fsnotify_put_mark(mark
);
503 p
= &chunk
->owners
[chunk
->count
- 1];
504 p
->index
= (chunk
->count
- 1) | (1U<<31);
507 list_add(&p
->list
, &tree
->chunks
);
510 list_add(&tree
->same_root
, &chunk
->trees
);
513 * This has to go last when updating chunk as once replace_chunk() is
514 * called, new RCU readers can see the new chunk.
516 replace_chunk(chunk
, old
);
517 spin_unlock(&hash_lock
);
518 mutex_unlock(&audit_tree_group
->mark_mutex
);
519 fsnotify_put_mark(mark
); /* pair to fsnotify_find_mark */
520 audit_mark_put_chunk(old
);
525 static void audit_tree_log_remove_rule(struct audit_context
*context
,
526 struct audit_krule
*rule
)
528 struct audit_buffer
*ab
;
532 ab
= audit_log_start(context
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
535 audit_log_format(ab
, "op=remove_rule dir=");
536 audit_log_untrustedstring(ab
, rule
->tree
->pathname
);
537 audit_log_key(ab
, rule
->filterkey
);
538 audit_log_format(ab
, " list=%d res=1", rule
->listnr
);
542 static void kill_rules(struct audit_context
*context
, struct audit_tree
*tree
)
544 struct audit_krule
*rule
, *next
;
545 struct audit_entry
*entry
;
547 list_for_each_entry_safe(rule
, next
, &tree
->rules
, rlist
) {
548 entry
= container_of(rule
, struct audit_entry
, rule
);
550 list_del_init(&rule
->rlist
);
552 /* not a half-baked one */
553 audit_tree_log_remove_rule(context
, rule
);
555 audit_remove_mark(entry
->rule
.exe
);
557 list_del_rcu(&entry
->list
);
558 list_del(&entry
->rule
.list
);
559 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
565 * Remove tree from chunks. If 'tagged' is set, remove tree only from tagged
566 * chunks. The function expects tagged chunks are all at the beginning of the
569 static void prune_tree_chunks(struct audit_tree
*victim
, bool tagged
)
571 spin_lock(&hash_lock
);
572 while (!list_empty(&victim
->chunks
)) {
574 struct audit_chunk
*chunk
;
575 struct fsnotify_mark
*mark
;
577 p
= list_first_entry(&victim
->chunks
, struct node
, list
);
578 /* have we run out of marked? */
579 if (tagged
&& !(p
->index
& (1U<<31)))
581 chunk
= find_chunk(p
);
583 remove_chunk_node(chunk
, p
);
584 /* Racing with audit_tree_freeing_mark()? */
587 fsnotify_get_mark(mark
);
588 spin_unlock(&hash_lock
);
590 untag_chunk(chunk
, mark
);
591 fsnotify_put_mark(mark
);
593 spin_lock(&hash_lock
);
595 spin_unlock(&hash_lock
);
599 * finish killing struct audit_tree
601 static void prune_one(struct audit_tree
*victim
)
603 prune_tree_chunks(victim
, false);
607 /* trim the uncommitted chunks from tree */
609 static void trim_marked(struct audit_tree
*tree
)
611 struct list_head
*p
, *q
;
612 spin_lock(&hash_lock
);
614 spin_unlock(&hash_lock
);
618 for (p
= tree
->chunks
.next
; p
!= &tree
->chunks
; p
= q
) {
619 struct node
*node
= list_entry(p
, struct node
, list
);
621 if (node
->index
& (1U<<31)) {
623 list_add(p
, &tree
->chunks
);
626 spin_unlock(&hash_lock
);
628 prune_tree_chunks(tree
, true);
630 spin_lock(&hash_lock
);
631 if (!tree
->root
&& !tree
->goner
) {
633 spin_unlock(&hash_lock
);
634 mutex_lock(&audit_filter_mutex
);
635 kill_rules(audit_context(), tree
);
636 list_del_init(&tree
->list
);
637 mutex_unlock(&audit_filter_mutex
);
640 spin_unlock(&hash_lock
);
644 static void audit_schedule_prune(void);
646 /* called with audit_filter_mutex */
647 int audit_remove_tree_rule(struct audit_krule
*rule
)
649 struct audit_tree
*tree
;
652 spin_lock(&hash_lock
);
653 list_del_init(&rule
->rlist
);
654 if (list_empty(&tree
->rules
) && !tree
->goner
) {
656 list_del_init(&tree
->same_root
);
658 list_move(&tree
->list
, &prune_list
);
660 spin_unlock(&hash_lock
);
661 audit_schedule_prune();
665 spin_unlock(&hash_lock
);
671 static int compare_root(struct vfsmount
*mnt
, void *arg
)
673 return inode_to_key(d_backing_inode(mnt
->mnt_root
)) ==
677 void audit_trim_trees(void)
679 struct list_head cursor
;
681 mutex_lock(&audit_filter_mutex
);
682 list_add(&cursor
, &tree_list
);
683 while (cursor
.next
!= &tree_list
) {
684 struct audit_tree
*tree
;
686 struct vfsmount
*root_mnt
;
690 tree
= container_of(cursor
.next
, struct audit_tree
, list
);
692 list_move(&cursor
, &tree
->list
);
693 mutex_unlock(&audit_filter_mutex
);
695 err
= kern_path(tree
->pathname
, 0, &path
);
699 root_mnt
= collect_mounts(&path
);
701 if (IS_ERR(root_mnt
))
704 spin_lock(&hash_lock
);
705 list_for_each_entry(node
, &tree
->chunks
, list
) {
706 struct audit_chunk
*chunk
= find_chunk(node
);
707 /* this could be NULL if the watch is dying else where... */
708 node
->index
|= 1U<<31;
709 if (iterate_mounts(compare_root
,
710 (void *)(chunk
->key
),
712 node
->index
&= ~(1U<<31);
714 spin_unlock(&hash_lock
);
716 drop_collected_mounts(root_mnt
);
719 mutex_lock(&audit_filter_mutex
);
722 mutex_unlock(&audit_filter_mutex
);
725 int audit_make_tree(struct audit_krule
*rule
, char *pathname
, u32 op
)
728 if (pathname
[0] != '/' ||
729 rule
->listnr
!= AUDIT_FILTER_EXIT
||
731 rule
->inode_f
|| rule
->watch
|| rule
->tree
)
733 rule
->tree
= alloc_tree(pathname
);
739 void audit_put_tree(struct audit_tree
*tree
)
744 static int tag_mount(struct vfsmount
*mnt
, void *arg
)
746 return tag_chunk(d_backing_inode(mnt
->mnt_root
), arg
);
750 * That gets run when evict_chunk() ends up needing to kill audit_tree.
751 * Runs from a separate thread.
753 static int prune_tree_thread(void *unused
)
756 if (list_empty(&prune_list
)) {
757 set_current_state(TASK_INTERRUPTIBLE
);
762 mutex_lock(&audit_filter_mutex
);
764 while (!list_empty(&prune_list
)) {
765 struct audit_tree
*victim
;
767 victim
= list_entry(prune_list
.next
,
768 struct audit_tree
, list
);
769 list_del_init(&victim
->list
);
771 mutex_unlock(&audit_filter_mutex
);
775 mutex_lock(&audit_filter_mutex
);
778 mutex_unlock(&audit_filter_mutex
);
784 static int audit_launch_prune(void)
788 prune_thread
= kthread_run(prune_tree_thread
, NULL
,
790 if (IS_ERR(prune_thread
)) {
791 pr_err("cannot start thread audit_prune_tree");
798 /* called with audit_filter_mutex */
799 int audit_add_tree_rule(struct audit_krule
*rule
)
801 struct audit_tree
*seed
= rule
->tree
, *tree
;
803 struct vfsmount
*mnt
;
807 list_for_each_entry(tree
, &tree_list
, list
) {
808 if (!strcmp(seed
->pathname
, tree
->pathname
)) {
811 list_add(&rule
->rlist
, &tree
->rules
);
816 list_add(&tree
->list
, &tree_list
);
817 list_add(&rule
->rlist
, &tree
->rules
);
818 /* do not set rule->tree yet */
819 mutex_unlock(&audit_filter_mutex
);
821 if (unlikely(!prune_thread
)) {
822 err
= audit_launch_prune();
827 err
= kern_path(tree
->pathname
, 0, &path
);
830 mnt
= collect_mounts(&path
);
838 err
= iterate_mounts(tag_mount
, tree
, mnt
);
839 drop_collected_mounts(mnt
);
843 spin_lock(&hash_lock
);
844 list_for_each_entry(node
, &tree
->chunks
, list
)
845 node
->index
&= ~(1U<<31);
846 spin_unlock(&hash_lock
);
852 mutex_lock(&audit_filter_mutex
);
853 if (list_empty(&rule
->rlist
)) {
862 mutex_lock(&audit_filter_mutex
);
863 list_del_init(&tree
->list
);
864 list_del_init(&tree
->rules
);
869 int audit_tag_tree(char *old
, char *new)
871 struct list_head cursor
, barrier
;
873 struct path path1
, path2
;
874 struct vfsmount
*tagged
;
877 err
= kern_path(new, 0, &path2
);
880 tagged
= collect_mounts(&path2
);
883 return PTR_ERR(tagged
);
885 err
= kern_path(old
, 0, &path1
);
887 drop_collected_mounts(tagged
);
891 mutex_lock(&audit_filter_mutex
);
892 list_add(&barrier
, &tree_list
);
893 list_add(&cursor
, &barrier
);
895 while (cursor
.next
!= &tree_list
) {
896 struct audit_tree
*tree
;
899 tree
= container_of(cursor
.next
, struct audit_tree
, list
);
901 list_move(&cursor
, &tree
->list
);
902 mutex_unlock(&audit_filter_mutex
);
904 err
= kern_path(tree
->pathname
, 0, &path2
);
906 good_one
= path_is_under(&path1
, &path2
);
912 mutex_lock(&audit_filter_mutex
);
916 failed
= iterate_mounts(tag_mount
, tree
, tagged
);
919 mutex_lock(&audit_filter_mutex
);
923 mutex_lock(&audit_filter_mutex
);
924 spin_lock(&hash_lock
);
926 list_move(&tree
->list
, &tree_list
);
928 spin_unlock(&hash_lock
);
932 while (barrier
.prev
!= &tree_list
) {
933 struct audit_tree
*tree
;
935 tree
= container_of(barrier
.prev
, struct audit_tree
, list
);
937 list_move(&tree
->list
, &barrier
);
938 mutex_unlock(&audit_filter_mutex
);
942 spin_lock(&hash_lock
);
943 list_for_each_entry(node
, &tree
->chunks
, list
)
944 node
->index
&= ~(1U<<31);
945 spin_unlock(&hash_lock
);
951 mutex_lock(&audit_filter_mutex
);
955 mutex_unlock(&audit_filter_mutex
);
957 drop_collected_mounts(tagged
);
962 static void audit_schedule_prune(void)
964 wake_up_process(prune_thread
);
968 * ... and that one is done if evict_chunk() decides to delay until the end
969 * of syscall. Runs synchronously.
971 void audit_kill_trees(struct audit_context
*context
)
973 struct list_head
*list
= &context
->killed_trees
;
976 mutex_lock(&audit_filter_mutex
);
978 while (!list_empty(list
)) {
979 struct audit_tree
*victim
;
981 victim
= list_entry(list
->next
, struct audit_tree
, list
);
982 kill_rules(context
, victim
);
983 list_del_init(&victim
->list
);
985 mutex_unlock(&audit_filter_mutex
);
989 mutex_lock(&audit_filter_mutex
);
992 mutex_unlock(&audit_filter_mutex
);
997 * Here comes the stuff asynchronous to auditctl operations
1000 static void evict_chunk(struct audit_chunk
*chunk
)
1002 struct audit_tree
*owner
;
1003 struct list_head
*postponed
= audit_killed_trees();
1007 mutex_lock(&audit_filter_mutex
);
1008 spin_lock(&hash_lock
);
1009 while (!list_empty(&chunk
->trees
)) {
1010 owner
= list_entry(chunk
->trees
.next
,
1011 struct audit_tree
, same_root
);
1014 list_del_init(&owner
->same_root
);
1015 spin_unlock(&hash_lock
);
1017 kill_rules(audit_context(), owner
);
1018 list_move(&owner
->list
, &prune_list
);
1021 list_move(&owner
->list
, postponed
);
1023 spin_lock(&hash_lock
);
1025 list_del_rcu(&chunk
->hash
);
1026 for (n
= 0; n
< chunk
->count
; n
++)
1027 list_del_init(&chunk
->owners
[n
].list
);
1028 spin_unlock(&hash_lock
);
1029 mutex_unlock(&audit_filter_mutex
);
1031 audit_schedule_prune();
1034 static int audit_tree_handle_event(struct fsnotify_mark
*mark
, u32 mask
,
1035 struct inode
*inode
, struct inode
*dir
,
1036 const struct qstr
*file_name
, u32 cookie
)
1041 static void audit_tree_freeing_mark(struct fsnotify_mark
*mark
,
1042 struct fsnotify_group
*group
)
1044 struct audit_chunk
*chunk
;
1046 mutex_lock(&mark
->group
->mark_mutex
);
1047 spin_lock(&hash_lock
);
1048 chunk
= mark_chunk(mark
);
1049 replace_mark_chunk(mark
, NULL
);
1050 spin_unlock(&hash_lock
);
1051 mutex_unlock(&mark
->group
->mark_mutex
);
1054 audit_mark_put_chunk(chunk
);
1058 * We are guaranteed to have at least one reference to the mark from
1059 * either the inode or the caller of fsnotify_destroy_mark().
1061 BUG_ON(refcount_read(&mark
->refcnt
) < 1);
1064 static const struct fsnotify_ops audit_tree_ops
= {
1065 .handle_inode_event
= audit_tree_handle_event
,
1066 .freeing_mark
= audit_tree_freeing_mark
,
1067 .free_mark
= audit_tree_destroy_watch
,
1070 static int __init
audit_tree_init(void)
1074 audit_tree_mark_cachep
= KMEM_CACHE(audit_tree_mark
, SLAB_PANIC
);
1076 audit_tree_group
= fsnotify_alloc_group(&audit_tree_ops
);
1077 if (IS_ERR(audit_tree_group
))
1078 audit_panic("cannot initialize fsnotify group for rectree watches");
1080 for (i
= 0; i
< HASH_SIZE
; i
++)
1081 INIT_LIST_HEAD(&chunk_hash_heads
[i
]);
1085 __initcall(audit_tree_init
);