[PATCH v3 07/14] yama: Remove redundant rcu_read_lock/unlock() in spin_lock
From: pengdonglin <hidden>
Date: 2025-09-16 04:49:01
Also in:
cgroups, intel-gfx, linux-acpi, linux-fsdevel, linux-nfs, linux-rt-devel, linux-s390, linux-security-module, linux-wireless, lkml
Subsystem:
security subsystem, the rest, yama security module · Maintainers:
Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds, Kees Cook
From: pengdonglin <redacted>
Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions")
there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
rcu_read_lock_sched() in terms of RCU read section and the relevant grace
period. That means that spin_lock(), which implies rcu_read_lock_sched(),
also implies rcu_read_lock().
There is no need no explicitly start a RCU read section if one has already
been started implicitly by spin_lock().
Simplify the code and remove the inner rcu_read_lock() invocation.
Cc: Kees Cook <kees@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: pengdonglin <redacted>
Signed-off-by: pengdonglin <redacted>
---
security/yama/yama_lsm.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index 3d064dd4e03f..60d38deb181b 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c@@ -117,14 +117,12 @@ static void yama_relation_cleanup(struct work_struct *work) struct ptrace_relation *relation; spin_lock(&ptracer_relations_lock); - rcu_read_lock(); list_for_each_entry_rcu(relation, &ptracer_relations, node) { if (relation->invalid) { list_del_rcu(&relation->node); kfree_rcu(relation, rcu); } } - rcu_read_unlock(); spin_unlock(&ptracer_relations_lock); }
@@ -152,7 +150,6 @@ static int yama_ptracer_add(struct task_struct *tracer, added->invalid = false; spin_lock(&ptracer_relations_lock); - rcu_read_lock(); list_for_each_entry_rcu(relation, &ptracer_relations, node) { if (relation->invalid) continue;
@@ -166,7 +163,6 @@ static int yama_ptracer_add(struct task_struct *tracer, list_add_rcu(&added->node, &ptracer_relations); out: - rcu_read_unlock(); spin_unlock(&ptracer_relations_lock); return 0; }
--
2.34.1