Re: [PATCH 2/8] x86/EFI: sections may not live at VA 0 in PE binaries

[Jan Beulich <jbeulich@xxxxxxxx>]

On 01.04.2021 14:01, Andrew Cooper wrote:
> On 01/04/2021 10:44, Jan Beulich wrote:
>> PE binaries specify section addresses by (32-bit) RVA. GNU ld up to at
>> least 2.36 would silently truncate the (negative) difference when a
>> section is placed below the image base. Such sections would also be
>> wrongly placed ahead of all "normal" ones. Since, for the time being,
>> we build xen.efi with --strip-debug anyway, .stab* can't appear. And
>> .comment has an entry in /DISCARD/ already anyway in the EFI case.
>>
>> Because of their unclear origin, keep the directives for the ELF case
>> though.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>> ---
>> It's certainly odd that we have stabs section entries in the script, but
>> no Dwarf ones.
> 
> Its not odd in the slightest, given the heritage and lack of anyone
> touching the linker file unless something is broken.

Heritage? Was stabs debug info ever used in any build of Xen?

> We've got dwarf symbols in xen-syms, have we not?

Yes, and that's why I mention the oddity: We have Dwarf debug info (and
hence .debug_* sections) in xen-syms without mentioning them in the
script, and we don't have stabs debug info in xen-syms yet we mention
the sections.

Jan