[PATCH v2 19/23] x86/qspinlock, kcsan: Instrument barrier of pv_queued_spin_unlock()

Marco Elver
2021-11-18T08:15:42Z

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>
---
arch/x86/include/asm/qspinlock.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index d86ab942219c..d87451df480b 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);
}

--
2.34.0.rc2.393.gf8c9666880-goog