From: Marco Elver <elver@google.com>
Date: Tue, 30 Nov 2021 11:44:27 +0000 (+0100)
Subject: x86/qspinlock, kcsan: Instrument barrier of pv_queued_spin_unlock()
X-Git-Tag: v5.17-rc1~158^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d93414e37586691dd2684a7f8ed05fb9cd640f83;p=thirdparty%2Fkernel%2Flinux.git

x86/qspinlock, kcsan: Instrument barrier of pv_queued_spin_unlock()

If CONFIG_PARAVIRT_SPINLOCKS=y, queued_spin_unlock() is implemented
using pv_queued_spin_unlock() which is entirely inline asm based. As
such, we do not receive any KCSAN barrier instrumentation via regular
atomic operations.

Add the missing KCSAN barrier instrumentation for the
CONFIG_PARAVIRT_SPINLOCKS case.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---

diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index d86ab942219c4..d87451df480bd 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -53,6 +53,7 @@ static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
 
 static inline void queued_spin_unlock(struct qspinlock *lock)
 {
+	kcsan_release();
 	pv_queued_spin_unlock(lock);
 }