From b8ed374e202e23caaf9bd77dcadc9de6447faaa8 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 27 Oct 2010 15:34:06 -0700 Subject: [PATCH] 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 Signed-off-by: Namhyung Kim Cc: Ingo Molnar Cc: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sched.h | 9 ++++++++- kernel/signal.c | 3 ++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 393ce94e54b7..3ff5c8519abd 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2236,9 +2236,16 @@ static inline void task_unlock(struct task_struct *p) 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) { diff --git a/kernel/signal.c b/kernel/signal.c index 919562c3d6b7..e921409b85a9 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1105,7 +1105,8 @@ int zap_other_threads(struct task_struct *p) return count; } -struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) +struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, + unsigned long *flags) { struct sighand_struct *sighand; -- 2.20.1