From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: [PATCH 08/10] audit: Provide helper for dropping mark's chunk reference Date: Tue, 10 Jul 2018 12:02:14 +0200 Message-ID: <20180710100217.12866-9-jack@suse.cz> References: <20180710100217.12866-1-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180710100217.12866-1-jack@suse.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: linux-audit@redhat.com Cc: Jan Kara , Richard Guy Briggs , Amir Goldstein , Al Viro , linux-fsdevel@vger.kernel.org List-Id: linux-audit@redhat.com Provide a helper function audit_mark_put_chunk() for dropping mark's reference (which has to happen only after RCU grace period expires). Currently that happens only from a single place but in later patches we introduce more callers. Signed-off-by: Jan Kara --- kernel/audit_tree.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index b7977cf30479..bce3b04a365d 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -132,10 +132,20 @@ static void __put_chunk(struct rcu_head *rcu) audit_put_chunk(chunk); } +/* + * Drop reference to the chunk that was held by the mark. This is the reference + * that gets dropped after we've removed the chunk from the hash table and we + * use it to make sure chunk cannot be freed before RCU grace period expires. + */ +static void audit_mark_put_chunk(struct audit_chunk *chunk) +{ + call_rcu(&chunk->head, __put_chunk); +} + static void audit_tree_destroy_watch(struct fsnotify_mark *entry) { struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); - call_rcu(&chunk->head, __put_chunk); + audit_mark_put_chunk(chunk); } static struct audit_chunk *alloc_chunk(int count) -- 2.16.4