[PATCH] locking: Fixup write_lock_nested() implementation.

Sebastian Andrzej Siewior
2021-11-23T16:07:19Z

Andrew, please merge it into:
locking/rwlocks: introduce write_lock_nested
locking-rwlocks-introduce-write_lock_nested.patch

And if someone could test it, I get sh4 defconfig built with and without
lockdep. x86 seems still to build, too. So it can't be that bad.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/rwlock_api_smp.h | 2 +-
kernel/locking/spinlock.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index f0c535ec4e654..60049df00532d 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -47,7 +47,7 @@ _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)

#ifdef CONFIG_INLINE_WRITE_LOCK
#define _raw_write_lock(lock) __raw_write_lock(lock)
-#define _raw_write_lock_nested(lock, subclass) __raw_write_lock_nested(lock, subclass)
+#define _raw_write_lock_nested(lock) __raw_write_lock(lock)
#endif

#ifdef CONFIG_INLINE_READ_LOCK_BH
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c
index 996811efa6d6e..7f49baaa49793 100644
--- a/kernel/locking/spinlock.c
+++ b/kernel/locking/spinlock.c
@@ -301,6 +301,10 @@ void __lockfunc _raw_write_lock(rwlock_t *lock)
}
EXPORT_SYMBOL(_raw_write_lock);

+#ifndef CONFIG_DEBUG_LOCK_ALLOC
+#define __raw_write_lock_nested(lock, subclass) __raw_write_lock(((void)(subclass), (lock)))
+#endif
+
void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)
{
__raw_write_lock_nested(lock, subclass);
--
2.34.0