signals: annotate lock_task_sighand()
lock_task_sighand() grabs sighand->siglock in case of returning non-NULL
but unlock_task_sighand() releases it unconditionally. This leads sparse
to complain about the lock context imbalance. Rename and wrap
lock_task_sighand() using __cond_lock() macro to make sparse happy.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 393ce94..3ff5c85 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2236,9 +2236,16 @@
spin_unlock(&p->alloc_lock);
}
-extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
+extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
unsigned long *flags);
+#define lock_task_sighand(tsk, flags) \
+({ struct sighand_struct *__ss; \
+ __cond_lock(&(tsk)->sighand->siglock, \
+ (__ss = __lock_task_sighand(tsk, flags))); \
+ __ss; \
+}) \
+
static inline void unlock_task_sighand(struct task_struct *tsk,
unsigned long *flags)
{