2 * Implementation of the kernel access vector cache (AVC).
4 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
7 * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com>
8 * Replaced the avc_lock spinlock by RCU.
10 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2,
14 * as published by the Free Software Foundation.
16 #include <linux/types.h>
17 #include <linux/stddef.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
21 #include <linux/dcache.h>
22 #include <linux/init.h>
23 #include <linux/skbuff.h>
24 #include <linux/percpu.h>
27 #include <net/af_unix.h>
29 #include <linux/audit.h>
30 #include <linux/ipv6.h>
36 #define AVC_CACHE_SLOTS 512
37 #define AVC_DEF_CACHE_THRESHOLD 512
38 #define AVC_CACHE_RECLAIM 16
40 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
41 #define avc_cache_stats_incr(field) this_cpu_inc(avc_cache_stats.field)
43 #define avc_cache_stats_incr(field) do {} while (0)
50 struct av_decision avd
;
55 struct hlist_node list
; /* anchored in avc_cache->slots[i] */
56 struct rcu_head rhead
;
60 struct hlist_head slots
[AVC_CACHE_SLOTS
]; /* head for avc_node->list */
61 spinlock_t slots_lock
[AVC_CACHE_SLOTS
]; /* lock for writes */
62 atomic_t lru_hint
; /* LRU hint for reclaim scan */
63 atomic_t active_nodes
;
64 u32 latest_notif
; /* latest revocation notification */
67 struct avc_callback_node
{
68 int (*callback
) (u32 event
, u32 ssid
, u32 tsid
,
69 u16 tclass
, u32 perms
,
76 struct avc_callback_node
*next
;
79 /* Exported via selinufs */
80 unsigned int avc_cache_threshold
= AVC_DEF_CACHE_THRESHOLD
;
82 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
83 DEFINE_PER_CPU(struct avc_cache_stats
, avc_cache_stats
) = { 0 };
86 static struct avc_cache avc_cache
;
87 static struct avc_callback_node
*avc_callbacks
;
88 static struct kmem_cache
*avc_node_cachep
;
90 static inline int avc_hash(u32 ssid
, u32 tsid
, u16 tclass
)
92 return (ssid
^ (tsid
<<2) ^ (tclass
<<4)) & (AVC_CACHE_SLOTS
- 1);
96 * avc_dump_av - Display an access vector in human-readable form.
97 * @tclass: target security class
100 static void avc_dump_av(struct audit_buffer
*ab
, u16 tclass
, u32 av
)
106 audit_log_format(ab
, " null");
110 perms
= secclass_map
[tclass
-1].perms
;
112 audit_log_format(ab
, " {");
115 while (i
< (sizeof(av
) * 8)) {
116 if ((perm
& av
) && perms
[i
]) {
117 audit_log_format(ab
, " %s", perms
[i
]);
125 audit_log_format(ab
, " 0x%x", av
);
127 audit_log_format(ab
, " }");
131 * avc_dump_query - Display a SID pair and a class in human-readable form.
132 * @ssid: source security identifier
133 * @tsid: target security identifier
134 * @tclass: target security class
136 static void avc_dump_query(struct audit_buffer
*ab
, u32 ssid
, u32 tsid
, u16 tclass
)
142 rc
= security_sid_to_context(ssid
, &scontext
, &scontext_len
);
144 audit_log_format(ab
, "ssid=%d", ssid
);
146 audit_log_format(ab
, "scontext=%s", scontext
);
150 rc
= security_sid_to_context(tsid
, &scontext
, &scontext_len
);
152 audit_log_format(ab
, " tsid=%d", tsid
);
154 audit_log_format(ab
, " tcontext=%s", scontext
);
158 BUG_ON(tclass
>= ARRAY_SIZE(secclass_map
));
159 audit_log_format(ab
, " tclass=%s", secclass_map
[tclass
-1].name
);
163 * avc_init - Initialize the AVC.
165 * Initialize the access vector cache.
167 void __init
avc_init(void)
171 for (i
= 0; i
< AVC_CACHE_SLOTS
; i
++) {
172 INIT_HLIST_HEAD(&avc_cache
.slots
[i
]);
173 spin_lock_init(&avc_cache
.slots_lock
[i
]);
175 atomic_set(&avc_cache
.active_nodes
, 0);
176 atomic_set(&avc_cache
.lru_hint
, 0);
178 avc_node_cachep
= kmem_cache_create("avc_node", sizeof(struct avc_node
),
179 0, SLAB_PANIC
, NULL
);
181 audit_log(current
->audit_context
, GFP_KERNEL
, AUDIT_KERNEL
, "AVC INITIALIZED\n");
184 int avc_get_hash_stats(char *page
)
186 int i
, chain_len
, max_chain_len
, slots_used
;
187 struct avc_node
*node
;
188 struct hlist_head
*head
;
194 for (i
= 0; i
< AVC_CACHE_SLOTS
; i
++) {
195 head
= &avc_cache
.slots
[i
];
196 if (!hlist_empty(head
)) {
197 struct hlist_node
*next
;
201 hlist_for_each_entry_rcu(node
, next
, head
, list
)
203 if (chain_len
> max_chain_len
)
204 max_chain_len
= chain_len
;
210 return scnprintf(page
, PAGE_SIZE
, "entries: %d\nbuckets used: %d/%d\n"
211 "longest chain: %d\n",
212 atomic_read(&avc_cache
.active_nodes
),
213 slots_used
, AVC_CACHE_SLOTS
, max_chain_len
);
216 static void avc_node_free(struct rcu_head
*rhead
)
218 struct avc_node
*node
= container_of(rhead
, struct avc_node
, rhead
);
219 kmem_cache_free(avc_node_cachep
, node
);
220 avc_cache_stats_incr(frees
);
223 static void avc_node_delete(struct avc_node
*node
)
225 hlist_del_rcu(&node
->list
);
226 call_rcu(&node
->rhead
, avc_node_free
);
227 atomic_dec(&avc_cache
.active_nodes
);
230 static void avc_node_kill(struct avc_node
*node
)
232 kmem_cache_free(avc_node_cachep
, node
);
233 avc_cache_stats_incr(frees
);
234 atomic_dec(&avc_cache
.active_nodes
);
237 static void avc_node_replace(struct avc_node
*new, struct avc_node
*old
)
239 hlist_replace_rcu(&old
->list
, &new->list
);
240 call_rcu(&old
->rhead
, avc_node_free
);
241 atomic_dec(&avc_cache
.active_nodes
);
244 static inline int avc_reclaim_node(void)
246 struct avc_node
*node
;
247 int hvalue
, try, ecx
;
249 struct hlist_head
*head
;
250 struct hlist_node
*next
;
253 for (try = 0, ecx
= 0; try < AVC_CACHE_SLOTS
; try++) {
254 hvalue
= atomic_inc_return(&avc_cache
.lru_hint
) & (AVC_CACHE_SLOTS
- 1);
255 head
= &avc_cache
.slots
[hvalue
];
256 lock
= &avc_cache
.slots_lock
[hvalue
];
258 if (!spin_trylock_irqsave(lock
, flags
))
262 hlist_for_each_entry(node
, next
, head
, list
) {
263 avc_node_delete(node
);
264 avc_cache_stats_incr(reclaims
);
266 if (ecx
>= AVC_CACHE_RECLAIM
) {
268 spin_unlock_irqrestore(lock
, flags
);
273 spin_unlock_irqrestore(lock
, flags
);
279 static struct avc_node
*avc_alloc_node(void)
281 struct avc_node
*node
;
283 node
= kmem_cache_zalloc(avc_node_cachep
, GFP_ATOMIC
);
287 INIT_HLIST_NODE(&node
->list
);
288 avc_cache_stats_incr(allocations
);
290 if (atomic_inc_return(&avc_cache
.active_nodes
) > avc_cache_threshold
)
297 static void avc_node_populate(struct avc_node
*node
, u32 ssid
, u32 tsid
, u16 tclass
, struct av_decision
*avd
)
299 node
->ae
.ssid
= ssid
;
300 node
->ae
.tsid
= tsid
;
301 node
->ae
.tclass
= tclass
;
302 memcpy(&node
->ae
.avd
, avd
, sizeof(node
->ae
.avd
));
305 static inline struct avc_node
*avc_search_node(u32 ssid
, u32 tsid
, u16 tclass
)
307 struct avc_node
*node
, *ret
= NULL
;
309 struct hlist_head
*head
;
310 struct hlist_node
*next
;
312 hvalue
= avc_hash(ssid
, tsid
, tclass
);
313 head
= &avc_cache
.slots
[hvalue
];
314 hlist_for_each_entry_rcu(node
, next
, head
, list
) {
315 if (ssid
== node
->ae
.ssid
&&
316 tclass
== node
->ae
.tclass
&&
317 tsid
== node
->ae
.tsid
) {
327 * avc_lookup - Look up an AVC entry.
328 * @ssid: source security identifier
329 * @tsid: target security identifier
330 * @tclass: target security class
332 * Look up an AVC entry that is valid for the
333 * (@ssid, @tsid), interpreting the permissions
334 * based on @tclass. If a valid AVC entry exists,
335 * then this function returns the avc_node.
336 * Otherwise, this function returns NULL.
338 static struct avc_node
*avc_lookup(u32 ssid
, u32 tsid
, u16 tclass
)
340 struct avc_node
*node
;
342 avc_cache_stats_incr(lookups
);
343 node
= avc_search_node(ssid
, tsid
, tclass
);
348 avc_cache_stats_incr(misses
);
352 static int avc_latest_notif_update(int seqno
, int is_insert
)
355 static DEFINE_SPINLOCK(notif_lock
);
358 spin_lock_irqsave(¬if_lock
, flag
);
360 if (seqno
< avc_cache
.latest_notif
) {
361 printk(KERN_WARNING
"SELinux: avc: seqno %d < latest_notif %d\n",
362 seqno
, avc_cache
.latest_notif
);
366 if (seqno
> avc_cache
.latest_notif
)
367 avc_cache
.latest_notif
= seqno
;
369 spin_unlock_irqrestore(¬if_lock
, flag
);
375 * avc_insert - Insert an AVC entry.
376 * @ssid: source security identifier
377 * @tsid: target security identifier
378 * @tclass: target security class
379 * @avd: resulting av decision
381 * Insert an AVC entry for the SID pair
382 * (@ssid, @tsid) and class @tclass.
383 * The access vectors and the sequence number are
384 * normally provided by the security server in
385 * response to a security_compute_av() call. If the
386 * sequence number @avd->seqno is not less than the latest
387 * revocation notification, then the function copies
388 * the access vectors into a cache entry, returns
389 * avc_node inserted. Otherwise, this function returns NULL.
391 static struct avc_node
*avc_insert(u32 ssid
, u32 tsid
, u16 tclass
, struct av_decision
*avd
)
393 struct avc_node
*pos
, *node
= NULL
;
397 if (avc_latest_notif_update(avd
->seqno
, 1))
400 node
= avc_alloc_node();
402 struct hlist_head
*head
;
403 struct hlist_node
*next
;
406 hvalue
= avc_hash(ssid
, tsid
, tclass
);
407 avc_node_populate(node
, ssid
, tsid
, tclass
, avd
);
409 head
= &avc_cache
.slots
[hvalue
];
410 lock
= &avc_cache
.slots_lock
[hvalue
];
412 spin_lock_irqsave(lock
, flag
);
413 hlist_for_each_entry(pos
, next
, head
, list
) {
414 if (pos
->ae
.ssid
== ssid
&&
415 pos
->ae
.tsid
== tsid
&&
416 pos
->ae
.tclass
== tclass
) {
417 avc_node_replace(node
, pos
);
421 hlist_add_head_rcu(&node
->list
, head
);
423 spin_unlock_irqrestore(lock
, flag
);
430 * avc_audit_pre_callback - SELinux specific information
431 * will be called by generic audit code
432 * @ab: the audit buffer
435 static void avc_audit_pre_callback(struct audit_buffer
*ab
, void *a
)
437 struct common_audit_data
*ad
= a
;
438 audit_log_format(ab
, "avc: %s ",
439 ad
->selinux_audit_data
.denied
? "denied" : "granted");
440 avc_dump_av(ab
, ad
->selinux_audit_data
.tclass
,
441 ad
->selinux_audit_data
.audited
);
442 audit_log_format(ab
, " for ");
446 * avc_audit_post_callback - SELinux specific information
447 * will be called by generic audit code
448 * @ab: the audit buffer
451 static void avc_audit_post_callback(struct audit_buffer
*ab
, void *a
)
453 struct common_audit_data
*ad
= a
;
454 audit_log_format(ab
, " ");
455 avc_dump_query(ab
, ad
->selinux_audit_data
.ssid
,
456 ad
->selinux_audit_data
.tsid
,
457 ad
->selinux_audit_data
.tclass
);
460 /* This is the slow part of avc audit with big stack footprint */
461 static noinline
int slow_avc_audit(u32 ssid
, u32 tsid
, u16 tclass
,
462 u32 requested
, u32 audited
, u32 denied
,
463 struct av_decision
*avd
, struct common_audit_data
*a
,
466 struct common_audit_data stack_data
;
470 COMMON_AUDIT_DATA_INIT(a
, NONE
);
474 * When in a RCU walk do the audit on the RCU retry. This is because
475 * the collection of the dname in an inode audit message is not RCU
476 * safe. Note this may drop some audits when the situation changes
477 * during retry. However this is logically just as if the operation
478 * happened a little later.
480 if ((a
->type
== LSM_AUDIT_DATA_INODE
) &&
481 (flags
& MAY_NOT_BLOCK
))
484 a
->selinux_audit_data
.tclass
= tclass
;
485 a
->selinux_audit_data
.requested
= requested
;
486 a
->selinux_audit_data
.ssid
= ssid
;
487 a
->selinux_audit_data
.tsid
= tsid
;
488 a
->selinux_audit_data
.audited
= audited
;
489 a
->selinux_audit_data
.denied
= denied
;
490 a
->lsm_pre_audit
= avc_audit_pre_callback
;
491 a
->lsm_post_audit
= avc_audit_post_callback
;
497 * avc_audit - Audit the granting or denial of permissions.
498 * @ssid: source security identifier
499 * @tsid: target security identifier
500 * @tclass: target security class
501 * @requested: requested permissions
502 * @avd: access vector decisions
503 * @result: result from avc_has_perm_noaudit
504 * @a: auxiliary audit data
505 * @flags: VFS walk flags
507 * Audit the granting or denial of permissions in accordance
508 * with the policy. This function is typically called by
509 * avc_has_perm() after a permission check, but can also be
510 * called directly by callers who use avc_has_perm_noaudit()
511 * in order to separate the permission check from the auditing.
512 * For example, this separation is useful when the permission check must
513 * be performed under a lock, to allow the lock to be released
514 * before calling the auditing code.
516 inline int avc_audit(u32 ssid
, u32 tsid
,
517 u16 tclass
, u32 requested
,
518 struct av_decision
*avd
, int result
, struct common_audit_data
*a
,
522 denied
= requested
& ~avd
->allowed
;
523 if (unlikely(denied
)) {
524 audited
= denied
& avd
->auditdeny
;
526 * a->selinux_audit_data.auditdeny is TRICKY! Setting a bit in
527 * this field means that ANY denials should NOT be audited if
528 * the policy contains an explicit dontaudit rule for that
529 * permission. Take notice that this is unrelated to the
530 * actual permissions that were denied. As an example lets
534 * avd.auditdeny & ACCESS == 0 (not set means explicit rule)
535 * selinux_audit_data.auditdeny & ACCESS == 1
537 * We will NOT audit the denial even though the denied
538 * permission was READ and the auditdeny checks were for
542 a
->selinux_audit_data
.auditdeny
&&
543 !(a
->selinux_audit_data
.auditdeny
& avd
->auditdeny
))
546 audited
= denied
= requested
;
548 audited
= requested
& avd
->auditallow
;
549 if (likely(!audited
))
552 return slow_avc_audit(ssid
, tsid
, tclass
,
553 requested
, audited
, denied
,
558 * avc_add_callback - Register a callback for security events.
559 * @callback: callback function
560 * @events: security events
561 * @ssid: source security identifier or %SECSID_WILD
562 * @tsid: target security identifier or %SECSID_WILD
563 * @tclass: target security class
564 * @perms: permissions
566 * Register a callback function for events in the set @events
567 * related to the SID pair (@ssid, @tsid)
568 * and the permissions @perms, interpreting
569 * @perms based on @tclass. Returns %0 on success or
570 * -%ENOMEM if insufficient memory exists to add the callback.
572 int avc_add_callback(int (*callback
)(u32 event
, u32 ssid
, u32 tsid
,
573 u16 tclass
, u32 perms
,
575 u32 events
, u32 ssid
, u32 tsid
,
576 u16 tclass
, u32 perms
)
578 struct avc_callback_node
*c
;
581 c
= kmalloc(sizeof(*c
), GFP_ATOMIC
);
587 c
->callback
= callback
;
592 c
->next
= avc_callbacks
;
598 static inline int avc_sidcmp(u32 x
, u32 y
)
600 return (x
== y
|| x
== SECSID_WILD
|| y
== SECSID_WILD
);
604 * avc_update_node Update an AVC entry
605 * @event : Updating event
606 * @perms : Permission mask bits
607 * @ssid,@tsid,@tclass : identifier of an AVC entry
608 * @seqno : sequence number when decision was made
610 * if a valid AVC entry doesn't exist,this function returns -ENOENT.
611 * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
612 * otherwise, this function updates the AVC entry. The original AVC-entry object
613 * will release later by RCU.
615 static int avc_update_node(u32 event
, u32 perms
, u32 ssid
, u32 tsid
, u16 tclass
,
620 struct avc_node
*pos
, *node
, *orig
= NULL
;
621 struct hlist_head
*head
;
622 struct hlist_node
*next
;
625 node
= avc_alloc_node();
631 /* Lock the target slot */
632 hvalue
= avc_hash(ssid
, tsid
, tclass
);
634 head
= &avc_cache
.slots
[hvalue
];
635 lock
= &avc_cache
.slots_lock
[hvalue
];
637 spin_lock_irqsave(lock
, flag
);
639 hlist_for_each_entry(pos
, next
, head
, list
) {
640 if (ssid
== pos
->ae
.ssid
&&
641 tsid
== pos
->ae
.tsid
&&
642 tclass
== pos
->ae
.tclass
&&
643 seqno
== pos
->ae
.avd
.seqno
){
656 * Copy and replace original node.
659 avc_node_populate(node
, ssid
, tsid
, tclass
, &orig
->ae
.avd
);
662 case AVC_CALLBACK_GRANT
:
663 node
->ae
.avd
.allowed
|= perms
;
665 case AVC_CALLBACK_TRY_REVOKE
:
666 case AVC_CALLBACK_REVOKE
:
667 node
->ae
.avd
.allowed
&= ~perms
;
669 case AVC_CALLBACK_AUDITALLOW_ENABLE
:
670 node
->ae
.avd
.auditallow
|= perms
;
672 case AVC_CALLBACK_AUDITALLOW_DISABLE
:
673 node
->ae
.avd
.auditallow
&= ~perms
;
675 case AVC_CALLBACK_AUDITDENY_ENABLE
:
676 node
->ae
.avd
.auditdeny
|= perms
;
678 case AVC_CALLBACK_AUDITDENY_DISABLE
:
679 node
->ae
.avd
.auditdeny
&= ~perms
;
682 avc_node_replace(node
, orig
);
684 spin_unlock_irqrestore(lock
, flag
);
690 * avc_flush - Flush the cache
692 static void avc_flush(void)
694 struct hlist_head
*head
;
695 struct hlist_node
*next
;
696 struct avc_node
*node
;
701 for (i
= 0; i
< AVC_CACHE_SLOTS
; i
++) {
702 head
= &avc_cache
.slots
[i
];
703 lock
= &avc_cache
.slots_lock
[i
];
705 spin_lock_irqsave(lock
, flag
);
707 * With preemptable RCU, the outer spinlock does not
708 * prevent RCU grace periods from ending.
711 hlist_for_each_entry(node
, next
, head
, list
)
712 avc_node_delete(node
);
714 spin_unlock_irqrestore(lock
, flag
);
719 * avc_ss_reset - Flush the cache and revalidate migrated permissions.
720 * @seqno: policy sequence number
722 int avc_ss_reset(u32 seqno
)
724 struct avc_callback_node
*c
;
729 for (c
= avc_callbacks
; c
; c
= c
->next
) {
730 if (c
->events
& AVC_CALLBACK_RESET
) {
731 tmprc
= c
->callback(AVC_CALLBACK_RESET
,
733 /* save the first error encountered for the return
734 value and continue processing the callbacks */
740 avc_latest_notif_update(seqno
, 0);
745 * Slow-path helper function for avc_has_perm_noaudit,
746 * when the avc_node lookup fails. We get called with
747 * the RCU read lock held, and need to return with it
748 * still held, but drop if for the security compute.
750 * Don't inline this, since it's the slow-path and just
751 * results in a bigger stack frame.
753 static noinline
struct avc_node
*avc_compute_av(u32 ssid
, u32 tsid
,
754 u16 tclass
, struct av_decision
*avd
)
757 security_compute_av(ssid
, tsid
, tclass
, avd
);
759 return avc_insert(ssid
, tsid
, tclass
, avd
);
762 static noinline
int avc_denied(u32 ssid
, u32 tsid
,
763 u16 tclass
, u32 requested
,
765 struct av_decision
*avd
)
767 if (flags
& AVC_STRICT
)
770 if (selinux_enforcing
&& !(avd
->flags
& AVD_FLAGS_PERMISSIVE
))
773 avc_update_node(AVC_CALLBACK_GRANT
, requested
, ssid
,
774 tsid
, tclass
, avd
->seqno
);
780 * avc_has_perm_noaudit - Check permissions but perform no auditing.
781 * @ssid: source security identifier
782 * @tsid: target security identifier
783 * @tclass: target security class
784 * @requested: requested permissions, interpreted based on @tclass
785 * @flags: AVC_STRICT or 0
786 * @avd: access vector decisions
788 * Check the AVC to determine whether the @requested permissions are granted
789 * for the SID pair (@ssid, @tsid), interpreting the permissions
790 * based on @tclass, and call the security server on a cache miss to obtain
791 * a new decision and add it to the cache. Return a copy of the decisions
792 * in @avd. Return %0 if all @requested permissions are granted,
793 * -%EACCES if any permissions are denied, or another -errno upon
794 * other errors. This function is typically called by avc_has_perm(),
795 * but may also be called directly to separate permission checking from
796 * auditing, e.g. in cases where a lock must be held for the check but
797 * should be released for the auditing.
799 inline int avc_has_perm_noaudit(u32 ssid
, u32 tsid
,
800 u16 tclass
, u32 requested
,
802 struct av_decision
*avd
)
804 struct avc_node
*node
;
812 node
= avc_lookup(ssid
, tsid
, tclass
);
813 if (unlikely(!node
)) {
814 node
= avc_compute_av(ssid
, tsid
, tclass
, avd
);
816 memcpy(avd
, &node
->ae
.avd
, sizeof(*avd
));
820 denied
= requested
& ~(avd
->allowed
);
821 if (unlikely(denied
))
822 rc
= avc_denied(ssid
, tsid
, tclass
, requested
, flags
, avd
);
829 * avc_has_perm - Check permissions and perform any appropriate auditing.
830 * @ssid: source security identifier
831 * @tsid: target security identifier
832 * @tclass: target security class
833 * @requested: requested permissions, interpreted based on @tclass
834 * @auditdata: auxiliary audit data
835 * @flags: VFS walk flags
837 * Check the AVC to determine whether the @requested permissions are granted
838 * for the SID pair (@ssid, @tsid), interpreting the permissions
839 * based on @tclass, and call the security server on a cache miss to obtain
840 * a new decision and add it to the cache. Audit the granting or denial of
841 * permissions in accordance with the policy. Return %0 if all @requested
842 * permissions are granted, -%EACCES if any permissions are denied, or
843 * another -errno upon other errors.
845 int avc_has_perm_flags(u32 ssid
, u32 tsid
, u16 tclass
,
846 u32 requested
, struct common_audit_data
*auditdata
,
849 struct av_decision avd
;
852 rc
= avc_has_perm_noaudit(ssid
, tsid
, tclass
, requested
, 0, &avd
);
854 rc2
= avc_audit(ssid
, tsid
, tclass
, requested
, &avd
, rc
, auditdata
,
861 u32
avc_policy_seqno(void)
863 return avc_cache
.latest_notif
;
866 void avc_disable(void)
869 * If you are looking at this because you have realized that we are
870 * not destroying the avc_node_cachep it might be easy to fix, but
871 * I don't know the memory barrier semantics well enough to know. It's
872 * possible that some other task dereferenced security_ops when
873 * it still pointed to selinux operations. If that is the case it's
874 * possible that it is about to use the avc and is about to need the
875 * avc_node_cachep. I know I could wrap the security.c security_ops call
876 * in an rcu_lock, but seriously, it's not worth it. Instead I just flush
877 * the cache and get that memory back.
879 if (avc_node_cachep
) {
881 /* kmem_cache_destroy(avc_node_cachep); */