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> --- 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