Re: [Xen-devel] [PATCH v2] x86/EFI: use less crude a way of generating the build ID

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 24/08/16 08:42, Jan Beulich wrote:
> Recent enough binutils (2.25 onwards) support --build-id also for
> COFF/PE output, and hence we should use that in favor of the original
> hack when possible.
>
> This gets complicated by the linker requiring at least one COFF object
> file to attach the .buildid section to. Hence the patch introduces a
> buildid.ihex (in order to avoid introducing binary files into the repo)
> which then gets converted to a binary minimal COFF object (no sections,
> no symbols).
>
> Also (to avoid both code fragment going out of sync) remove an unneeded
> ALIGN() from xen.lds.S: Adding an equivalent of it to the .buildid
> section would cause the _erodata symbol to become associated with the
> wrong section again (see commit 0970299de5 ["x86/EFI + Live Patch:
> avoid symbol address truncation"]). And it's pointless because the
> alignment already gets properly set by the input section(s).
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

I am going to presume the COFF stuff is fine.

> ---
> v2: Fix --build-id support detection: Only pass -m option (some of the
>     others result in an error message confusing ld-ver-build-id).
> ---
> Question of course is whether consumers of the build ID other than Xen
> itself need to be taught how to find it in an EFI binary.

If any do, we can see about adding support.  I wouldn't block this patch
on such an issue.

~Andrew

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel