Re: [PATCH] xen/x86: fix xen.efi boot crash from some bootloaders

["Anthony PERARD" <anthony.perard@vates.tech>]

On Wed, Jul 23, 2025 at 01:56:33PM +0000, Yann Sionneau wrote:
> diff --git a/xen/Makefile b/xen/Makefile
> index 8fc4e042ff..7dc9cd7e05 100644
> --- a/xen/Makefile
> +++ b/xen/Makefile
> @@ -299,10 +299,13 @@ export XEN_HAS_CHECKPOLICY := $(call success,$(CHECKPOLICY) -h 2>&1 | grep -q xe
>  # ===========================================================================
>  # Rules shared between *config targets and build targets
>  
> -PHONY += tools_fixdep
> +PHONY += tools_fixdep tools_keeprelocs
>  tools_fixdep:
>  	$(Q)$(MAKE) $(build)=tools tools/fixdep
>  
> +tools_keeprelocs:
> +	$(Q)$(MAKE) $(build)=tools tools/keeprelocs

You don't need this new rule, and nothing calls it. `tools_fixdep` is
special as it is used by the build system and very early one.

There's the command `$(Q)$(MAKE) $(build)=tools` which will build
this new binary for you, it is the first call in the rule `$(TARGET)`.
So beside editing xen/tools/Makefile, there's nothing else to do to have
a build of this new binary.

> diff --git a/xen/tools/Makefile b/xen/tools/Makefile
> index a5078b7cb8..4fd917b398 100644
> --- a/xen/tools/Makefile
> +++ b/xen/tools/Makefile
> @@ -1,2 +1,5 @@
>  hostprogs-always-y += symbols
>  hostprogs-always-y += fixdep
> +hostprogs-always-$(XEN_BUILD_PE) += keeprelocs
> +# next line is to allow including include/efi/pe.h
> +HOSTCFLAGS_keeprelocs.o := -I ../include

`../include` doesn't exist, and `..` might not exist or might be outside
the build directory.

In the directory "xen/" (and the subdirectories) all the commands are
executed from "xen/". Also, "xen/" directory can be built out-of-tree.
In both case, `..` isn't the directory you are looking for.

You can try out-of-tree build with:
    make -C xen O=path/to/build-tree
Or:
    cd path/to/build-tree; make -f path/to/xen.git/xen/Makefile

Anyway, for the build to work, you want:

    HOSTCFLAGS_keeprelocs.o := -I $(srctree)/include

Thanks,

-- 

Anthony Perard | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech