This patch adjust the example code with following two purpose:
* reduce the confusion on not releasing e->lock
* emphasize e is valid and not stale with e->lock held
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
CC: Boqun Feng <boqun.feng@xxxxxxxxx>
CC: Alan Huang <mmpgouride@xxxxxxxxx>
---
v2:
* add the missing parameter *key
* make function return struct audit_entry
---
Documentation/RCU/listRCU.rst | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/Documentation/RCU/listRCU.rst b/Documentation/RCU/listRCU.rst
index ed5c9d8c9afe..d8bb98623c12 100644
--- a/Documentation/RCU/listRCU.rst
+++ b/Documentation/RCU/listRCU.rst
@@ -334,7 +334,7 @@ If the system-call audit module were to ever need to reject stale data, one way
to accomplish this would be to add a ``deleted`` flag and a ``lock`` spinlock to the
``audit_entry`` structure, and modify audit_filter_task() as follows::
- static enum audit_state audit_filter_task(struct task_struct *tsk)
+ static struct audit_entry *audit_filter_task(struct task_struct *tsk, char **key)
{
struct audit_entry *e;
enum audit_state state;
@@ -346,16 +346,18 @@ to accomplish this would be to add a ``deleted`` flag and a ``lock`` spinlock to
if (e->deleted) {
spin_unlock(&e->lock);
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
+ return NULL;
}
rcu_read_unlock();
if (state == AUDIT_STATE_RECORD)
*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
- return state;
+ /* As long as e->lock is held, e is valid and
+ * its value is not stale */
+ return e;
}
}
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
+ return NULL;
}
The ``audit_del_rule()`` function would need to set the ``deleted`` flag under the
--
2.34.1
