On 09/22, Waiman Long wrote:
This patch is currently only active for 64-bit architectures.Why?
--- a/kernel/signal.cNo, nobody else should modify current->blocked.
@@ -2485,6 +2485,16 @@ void __set_current_blocked(const sigset_t *newset)
struct task_struct *tsk = current;
+ * In case the signal mask hasn't changed, we won't need to take
+ * the lock. As the current blocked mask can be modified by other
+ * CPUs,
Yes, we need to cleanup the usage of force_sig_info(), and probably remove
the "struct task_struct *t" argument.
we need to do an atomic read without lock. In other words,OK, agreed, but this should not depend on _NSIG_WORDS == 1 and
+ * this check will only be done on 64-bit systems.
+#if _NSIG_WORDS == 1
+ if (READ_ONCE(tsk->blocked.sig) == newset->sig)
READ_ONCE() looks confusing. It seems you need to add the new helper