[PATCH v4 08/14] security: Move call_rcu() to call_rcu_lazy()

From: Joel Fernandes (Google)
Date: Fri Aug 19 2022 - 16:49:39 EST


This is required to prevent callbacks triggering RCU machinery too
quickly and too often, which adds more power to the system.

Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
security/security.c | 2 +-
security/selinux/avc.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/security.c b/security/security.c
index ea7163c20751..d76f4951b2bd 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1053,7 +1053,7 @@ void security_inode_free(struct inode *inode)
* The inode will be freed after the RCU grace period too.
*/
if (inode->i_security)
- call_rcu((struct rcu_head *)inode->i_security,
+ call_rcu_lazy((struct rcu_head *)inode->i_security,
inode_free_by_rcu);
}

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 9a43af0ebd7d..381f046d820f 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -442,7 +442,7 @@ static void avc_node_free(struct rcu_head *rhead)
static void avc_node_delete(struct selinux_avc *avc, struct avc_node *node)
{
hlist_del_rcu(&node->list);
- call_rcu(&node->rhead, avc_node_free);
+ call_rcu_lazy(&node->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
}

@@ -458,7 +458,7 @@ static void avc_node_replace(struct selinux_avc *avc,
struct avc_node *new, struct avc_node *old)
{
hlist_replace_rcu(&old->list, &new->list);
- call_rcu(&old->rhead, avc_node_free);
+ call_rcu_lazy(&old->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
}

--
2.37.2.609.g9ff673ca1a-goog