Re: [XEN PATCH v2 03/10] misra: add deviations for direct inclusion guards

[Jan Beulich <jbeulich@xxxxxxxx>]

On 12.09.2023 11:36, Simone Ballarin wrote:
> --- a/docs/misra/safe.json
> +++ b/docs/misra/safe.json
> @@ -36,6 +36,14 @@
>          },
>          {
>              "id": "SAF-4-safe",
> +            "analyser": {
> +                "eclair": "MC3R1.D4.10"
> +            },
> +            "name": "Dir 4.10: direct inclusion guard before",
> +            "text": "Headers with just the direct inclusion guard before the 
> inclusion guard are safe."
> +        },
> +        {
> +            "id": "SAF-5-safe",
>              "analyser": {},
>              "name": "Sentinel",
>              "text": "Next ID to be used"
> diff --git a/xen/arch/arm/include/asm/hypercall.h 
> b/xen/arch/arm/include/asm/hypercall.h
> index ccd26c5184..24f8c61a73 100644
> --- a/xen/arch/arm/include/asm/hypercall.h
> +++ b/xen/arch/arm/include/asm/hypercall.h
> @@ -1,3 +1,4 @@
> +/* SAF-3-safe direct inclusion guard before */
>  #ifndef __XEN_HYPERCALL_H__
>  #error "asm/hypercall.h should not be included directly - include 
> xen/hypercall.h instead"
>  #endif
> diff --git a/xen/arch/x86/include/asm/hypercall.h 
> b/xen/arch/x86/include/asm/hypercall.h
> index ec2edc771e..dfdfe80021 100644
> --- a/xen/arch/x86/include/asm/hypercall.h
> +++ b/xen/arch/x86/include/asm/hypercall.h
> @@ -2,6 +2,7 @@
>   * asm-x86/hypercall.h
>   */
>  
> +/* SAF-3-safe direct inclusion guard before */
>  #ifndef __XEN_HYPERCALL_H__
>  #error "asm/hypercall.h should not be included directly - include 
> xen/hypercall.h instead"
>  #endif
> diff --git a/xen/include/xen/unaligned.h b/xen/include/xen/unaligned.h
> index 0a2b16d05d..190ada7800 100644
> --- a/xen/include/xen/unaligned.h
> +++ b/xen/include/xen/unaligned.h
> @@ -3,6 +3,7 @@
>   * without faulting, and at least reasonably efficiently.  Other 
> architectures
>   * will need to have a custom asm/unaligned.h.
>   */
> +/* SAF-3-safe direct inclusion guard before */
>  #ifndef __ASM_UNALIGNED_H__
>  #error "xen/unaligned.h should not be included directly - include 
> asm/unaligned.h instead"
>  #endif

Apart from the recurring off-by-1, will this have the intended effect of
Eclair still choking if there's then no inclusion guard following these
early constructs?

Jan