From 6aa9707099c4b25700940eb3d016f16c4434360d Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Wed, 27 Feb 2013 17:03:18 -0800 Subject: lockdep: check that no locks held at freeze time We shouldn't try_to_freeze if locks are held. Holding a lock can cause a deadlock if the lock is later acquired in the suspend or hibernate path (e.g. by dpm). Holding a lock can also cause a deadlock in the case of cgroup_freezer if a lock is held inside a frozen cgroup that is later acquired by a process outside that group. [akpm@linux-foundation.org: export debug_check_no_locks_held] Signed-off-by: Mandeep Singh Baines Cc: Ben Chan Cc: Oleg Nesterov Cc: Tejun Heo Cc: Rafael J. Wysocki Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/freezer.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/freezer.h') diff --git a/include/linux/freezer.h b/include/linux/freezer.h index e70df40d84f6..043a5cf8b5ba 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -3,6 +3,7 @@ #ifndef FREEZER_H_INCLUDED #define FREEZER_H_INCLUDED +#include #include #include #include @@ -48,6 +49,8 @@ extern void thaw_kernel_threads(void); static inline bool try_to_freeze(void) { + if (!(current->flags & PF_NOFREEZE)) + debug_check_no_locks_held(); might_sleep(); if (likely(!freezing(current))) return false; -- cgit v1.2.3