From a60326fd8a789cc90f98acaa9def42714ef6ed92 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 14 Aug 2019 17:08:58 +0200
Subject: [PATCH 471/518] x86: preempt: Check preemption level before looking
 at lazy-preempt

[ Upstream commit 19fc8557f2323c52b26561651ed4d51fc688a740 ]

Before evaluating the lazy-preempt state it must be ensure that the
preempt-count is zero.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
---
 arch/x86/include/asm/preempt.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index f667087792747..afa0e42ccdd12 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -96,6 +96,8 @@ static __always_inline bool __preempt_count_dec_and_test(void)
 	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);
-- 
2.41.0

