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

[PATCH] 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.

Signed-off-by: Sasha Levin <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 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/io_uring/mini_liburing.h b/tools/include/io_uring/mini_liburing.h
index 44be4446feda5..1f5b0cfc1e5b6 100644
--- a/tools/include/io_uring/mini_liburing.h
+++ b/tools/include/io_uring/mini_liburing.h
@@ -269,7 +269,7 @@ 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] selftests/io_uring: cast optval through uintptr_t in mini_liburing.h

[Breno Leitao]

On Tue, Nov 03, 2026 at 11:39:26AM -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.

Thanks for the fix.
I see the same warning with gcc -m32, and it is gone with this patch.

> Signed-off-by: Sasha Levin <sashal@kernel.org>

Reviewed-by: Breno Leitao <leitao@debian.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 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/include/io_uring/mini_liburing.h b/tools/include/io_uring/mini_liburing.h
> index 44be4446feda5..1f5b0cfc1e5b6 100644
> --- a/tools/include/io_uring/mini_liburing.h
> +++ b/tools/include/io_uring/mini_liburing.h
> @@ -269,7 +269,7 @@ 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;

mini_liburing.h doesn't include <stdint.h>, so uintptr_t only resolves
because both users include it first: io_uring_zerocopy_tx.c directly,
and prog_tests/sockopt.c through bpf/bpf.h and bpf/libbpf.h from
test_progs.h.

Since this adds the first uintptr_t in the file, should it
also add #include <stdint.h> next to the other includes?