io_uring: fix off-by-one in BUILD_BUG_ON check of __REQ_F_LAST_BIT

[ Upstream commit 32c2d33e0b7c4ea53284d5d9435dd022b582c8cf ]

Build check of __REQ_F_LAST_BIT should be larger than, not equal or larger
than. It's perfectly valid to have __REQ_F_LAST_BIT be 32, as that means
that the last valid bit is 31 which does fit in the type.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210907032243.114190-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 43aaa3566431557f67589e840f635bd8140020fa..754d59f734d84893db12fed78cd8b533015592a0 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -10335,7 +10335,7 @@ static int __init io_uring_init(void)
        BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
 
        BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
-       BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
+       BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));
 
        req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
                                SLAB_ACCOUNT);