[PATCH v2] selftests/io_uring: cast optval through uintptr_t in mini_liburing.h

[PATCH v2] selftests/io_uring: cast optval through uintptr_t in mini_liburing.h

[Sasha Levin]

io_uring_prep_cmd() puts the optval pointer into the 64-bit optval field
of the SQE with a plain cast, which warns on 32-bit architectures:

  mini_liburing.h:272:23: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

Cast through uintptr_t, and include <stdint.h> for it.

Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
v2: include <stdint.h> for uintptr_t (Breno).
v1: https://lore.kernel.org/r/20261103163926.641431-1-sashal@kernel.org

Found with 32-bit builds of the selftests (gcc 16 and clang 21 with
-m32, with and without -D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64);
KernelCI's 32-bit arm builds show the same warnings. The changed files
build without them now, and the x86_64 builds don't change.

 tools/include/io_uring/mini_liburing.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/include/io_uring/mini_liburing.h b/tools/include/io_uring/mini_liburing.h
index 44be4446feda5..6afe7efb44978 100644
--- a/tools/include/io_uring/mini_liburing.h
+++ b/tools/include/io_uring/mini_liburing.h
@@ -3,6 +3,7 @@
 #include <linux/io_uring.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -269,7 +270,7 @@ static inline void io_uring_prep_cmd(struct io_uring_sqe *sqe, int op,
 
 	sqe->level = level;
 	sqe->optname = optname;
-	sqe->optval = (unsigned long long)optval;
+	sqe->optval = (unsigned long long)(uintptr_t)optval;
 	sqe->optlen = optlen;
 }
 
-- 
2.53.0

Re: [PATCH v2] selftests/io_uring: cast optval through uintptr_t in mini_liburing.h

[Jens Axboe]

On Wed, 04 Nov 2026 09:46:23 -0500, Sasha Levin wrote:
> io_uring_prep_cmd() puts the optval pointer into the 64-bit optval field
> of the SQE with a plain cast, which warns on 32-bit architectures:
> 
>   mini_liburing.h:272:23: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> 
> Cast through uintptr_t, and include <stdint.h> for it.
> 
> [...]

Applied, thanks!

[1/1] selftests/io_uring: cast optval through uintptr_t in mini_liburing.h
      commit: 699e7ba5915c8b2c76e257e157464f2bfe7ab8bb

Best regards,
-- 
Jens Axboe