rw_semaphore implementation allows recursing calls to down_read, but lockdep thinks that it doesn't. As a result, it will complain false-positively, e.g. if we do not observe some predefined locking order when taking an rw semaphore for reading and a mutex.
This patch makes lockdep think rw semaphore is read-recursive, just like rw spin lock. Signed-off-by: Vladimir Davydov <vdavy...@parallels.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ingo Molnar <mi...@redhat.com> --- include/linux/lockdep.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 008388f920d7..4b95fe85375e 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -500,7 +500,7 @@ static inline void print_irqtrace_events(struct task_struct *curr) #define rwsem_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) #define rwsem_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) -#define rwsem_acquire_read(l, s, t, i) lock_acquire_shared(l, s, t, NULL, i) +#define rwsem_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) #define rwsem_release(l, n, i) lock_release(l, n, i) #define lock_map_acquire(l) lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
