asm-generic: rwsem: ensure sem->cnt is only accessed via atomic_long_*

The asm-generic rwsem implementation directly acceses sem->cnt when
performing a __down_read_trylock operation. Whilst this is probably safe
on all architectures, we should stick to the atomic_long_* API and use
atomic_long_read instead.

Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index bb1e2cdeb..75af612f5 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -41,7 +41,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
 {
 	long tmp;
 
-	while ((tmp = sem->count) >= 0) {
+	while ((tmp = atomic_long_read((atomic_long_t *)&sem->count)) >= 0) {
 		if (tmp == cmpxchg(&sem->count, tmp,
 				   tmp + RWSEM_ACTIVE_READ_BIAS)) {
 			return 1;