From: Sebastian Andrzej Siewior Date: Wed, 14 Aug 2019 17:08:58 +0200 Subject: [PATCH] x86: preempt: Check preemption level before looking at lazy-preempt Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.2/older/patches-5.2.10-rt5.tar.xz Before evaluating the lazy-preempt state it must be ensure that the preempt-count is zero. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/preempt.h | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -99,6 +99,8 @@ static __always_inline bool __preempt_co if (____preempt_count_dec_and_test()) return true; #ifdef CONFIG_PREEMPT_LAZY + if (preempt_count()) + return false; if (current_thread_info()->preempt_lazy_count) return false; return test_thread_flag(TIF_NEED_RESCHED_LAZY);