Re: [PATCH v2] x86/boot: Fix include paths for 32bit objects

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Sep 03, 2024 at 12:53:34PM +0100, Andrew Cooper wrote:
> Most of Xen is build using -nostdinc and a fully specified include path.
> However, the makefile line:
> 
>   $(head-bin-objs): XEN_CFLAGS := $(CFLAGS_x86_32) -fpic
> 
> discards XEN_CFLAGS and replaces them with CFLAGS_x86_32.
> 
> Reinstate -nostdinc, and copy all -I (and -Wa,-I) arguments from XEN_CFLAGS.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

I wouldn't mind if you also open-coded the config.h -include addition
to CFLAGS_x86_32, regardless:

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

I do wonder however whether the explicit assembler includes parameters
(-Wa,-I) are actually required, seeing as we only provide include/ to
the assembler, but not the arch-specific include paths.

This is from XSA-254, which used the '.include' asm directive, but
that was ultimately removed by:

762c3890c89f x86: fold indirect_thunk_asm.h into asm-defns.h

So maybe the -Wa,-I is no longer needed?

Thanks, Roger.