Re: [PATCH 8/8] virtio_ring.h: do not include <stdint.h> from exported header

[Michael S. Tsirkin]

On Mon, Apr 04, 2022 at 03:19:48PM +0900, Masahiro Yamada wrote:
> Arnd mentioned a limitation when including <stdint.h> from UAPI
> headers. [1]
> 
> Besides, I'd like exported headers to be as compliant with the
> traditional C as possible.
> 
> In fact, the UAPI headers are compile-tested with -std=c90 (see
> usr/include/Makefile) even though the kernel itself is now built
> with -std=gnu11.
> 
> Currently, include/uapi/linux/virtio_ring.h includes <stdint.h>
> presumably because it uses uintptr_t.
> 
> Replace it with __kernel_uintptr_t, and stop including <stdint.h>.
> 
> [1]: https://lore.kernel.org/all/CAK8P3a0bz8XYJOsmND2=CT_oTDmGMJGaRo9+QMroEhpekSMEaQ@xxxxxxxxxxxxxx/
> 
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>

Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

> ---
> 
>  include/uapi/linux/virtio_ring.h | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
> index 476d3e5c0fe7..6329e4ff35f4 100644
> --- a/include/uapi/linux/virtio_ring.h
> +++ b/include/uapi/linux/virtio_ring.h
> @@ -31,9 +31,7 @@
>   * SUCH DAMAGE.
>   *
>   * Copyright Rusty Russell IBM Corporation 2007. */
> -#ifndef __KERNEL__
> -#include <stdint.h>
> -#endif
> +
>  #include <linux/types.h>
>  #include <linux/virtio_types.h>
>  
> @@ -196,7 +194,7 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p,
>  	vr->num = num;
>  	vr->desc = p;
>  	vr->avail = (struct vring_avail *)((char *)p + num * sizeof(struct vring_desc));
> -	vr->used = (void *)(((uintptr_t)&vr->avail->ring[num] + sizeof(__virtio16)
> +	vr->used = (void *)(((__kernel_uintptr_t)&vr->avail->ring[num] + sizeof(__virtio16)
>  		+ align-1) & ~(align - 1));
>  }
>  
> -- 
> 2.32.0
> 
>