diff options
| author | Wei Yang <richard.weiyang@gmail.com> | 2025-02-18 00:50:47 +0000 |
|---|---|---|
| committer | Joel Fernandes <joelagnelf@nvidia.com> | 2025-05-16 09:00:54 -0400 |
| commit | 79ea7f43f8d5aeefc711d4ce322e0a7fbf41de14 (patch) | |
| tree | 7499416a6b95347d910c3eed3344bb28131ad79a | |
| parent | 1708bf2cc46a3136cc5928c1027b2a3d25a41f94 (diff) | |
doc/RCU/listRCU: refine example code for eliminating stale data
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@gmail.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Alan Huang <mmpgouride@gmail.com>
Reviewed-by: Alan Huang <mmpgouride@gmail.com>
Link: https://lore.kernel.org/r/20250218005047.27258-1-richard.weiyang@gmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
| -rw-r--r-- | Documentation/RCU/listRCU.rst | 10 |
1 files 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 |