Re: [PATCH v13 14/26] UAPI: x86: Move pvclock-abi to UAPI for x86 platforms

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] x86/xen: missing asm/types.h in xen-hypercalls.sh truncates
  xen-hypercalls.h
--

commit 02c9335f9071a6232c46010946be3c3ff37343b0
Author: Jack Allister <jalliste@amazon.com>

UAPI: x86: Move pvclock-abi to UAPI for x86 platforms

This commit moves arch/x86/include/asm/pvclock-abi.h to UAPI so userspace
can access struct pvclock_vcpu_time_info, switches its field types to UAPI
types via linux/types.h, and passes -D__KERNEL__ in
scripts/xen-hypercalls.sh.

> diff --git a/arch/x86/include/asm/pvclock-abi.h b/arch/x86/include/uapi/asm/pvclock-abi.h
> similarity index 82%
> rename from arch/x86/include/asm/pvclock-abi.h
> rename to arch/x86/include/uapi/asm/pvclock-abi.h
> index b9fece5fc96d6..6d70cf6403629 100644
> --- a/arch/x86/include/asm/pvclock-abi.h
> +++ b/arch/x86/include/uapi/asm/pvclock-abi.h
> @@ -1,6 +1,9 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
>  #ifndef _ASM_X86_PVCLOCK_ABI_H
>  #define _ASM_X86_PVCLOCK_ABI_H
> +
> +#include <linux/types.h>
> +
>  #ifndef __ASSEMBLER__

[ ... ]

> diff --git a/scripts/xen-hypercalls.sh b/scripts/xen-hypercalls.sh
> index f18b00843df3f..51a722198997d 100755
> --- a/scripts/xen-hypercalls.sh
> +++ b/scripts/xen-hypercalls.sh
> @@ -5,7 +5,7 @@ shift
>  in="$@"
>  
>  for i in $in; do
> -	eval $CPP $LINUXINCLUDE -dD -imacros "$i" -x c /dev/null
> +	eval $CPP -D__KERNEL__ $LINUXINCLUDE -dD -imacros "$i" -x c /dev/null
>  done | \
>  awk '$1 == "#define" && $2 ~ /__HYPERVISOR_[a-z][a-z_0-9]*/ { v[$3] = $2 }
>  	END {   print "/* auto-generated by scripts/xen-hypercall.sh */"

[Severity: Medium]
Does scripts/xen-hypercalls.sh fail to find asm/types.h on a clean x86
build with CONFIG_XEN=y, producing a truncated
arch/x86/include/generated/asm/xen-hypercalls.h?

When scripts/xen-hypercalls.sh preprocesses include/xen/interface/xen.h, it
pulls in asm/xen/interface.h -> asm/pvclock-abi.h -> linux/types.h ->
uapi/linux/types.h -> asm/types.h before the __HYPERVISOR_* definitions in
include/xen/interface/xen.h.  On x86, asm/types.h is generated in
arch/x86/include/generated/uapi/asm/types.h by the uapi-asm-generic target,
which is a prerequisite of asm-generic.  However, scripts/xen-hypercalls.sh
runs during archheaders, which archprepare orders before asm-generic
without a dependency on uapi-asm-generic:

Makefile:
archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
	asm-generic $(version_h) include/generated/utsrelease.h \

Because the pipeline in scripts/xen-hypercalls.sh ignores $CPP failures, the
build continues after $CPP aborts on missing asm/types.h and writes a
xen-hypercalls.h containing only HYPERCALL(mca) from xen-mca.h, which leaves
xen_hypercall_name() in arch/x86/xen/trace.c unable to resolve standard Xen
hypercall names for tracepoints.

Having archheaders depend on uapi-asm-generic (or avoiding the linux/types.h
dependency when preprocessing the hypercall headers) would ensure
asm/types.h is present before scripts/xen-hypercalls.sh runs.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261111180922.4177927-1-dwmw2@infradead.org?part=14