Re: PT_NOTE alignment, NT_GNU_PROPERTY_TYPE_0, glibc and gold

["H.J. Lu" <hjl.tools@gmail.com>]

On Thu, Aug 16, 2018 at 12:16 PM, Mark Wielaard <mark@klomp.org> wrote:
> On Thu, Aug 16, 2018 at 04:21:05PM +0200, Florian Weimer wrote:
>> On 08/16/2018 03:39 PM, H.J. Lu wrote:
>> > glibc only discards 4-byte aligned NT_GNU_PROPERTY_TYPE_0 note
>> > since NT_GNU_PROPERTY_TYPE_0 note follows gABI.  If gold
>> > generates 4 byte alignment, it is a gold bug.
>>
>> I filed: https://sourceware.org/bugzilla/show_bug.cgi?id=23535
>
> I don't think this is a bug in gold, but one in ld:
> https://sourceware.org/bugzilla/show_bug.cgi?id=22749
>
> In the GNU abi all ELF Notes are arrays of 32bit words
> (and so 4-byte aligned). This is the same for most other

That is not true.  NT_GNU_PROPERTY_TYPE_0 note is
8 byte aligned in 64-bit ELF.

> ELF systems. Making the ELF Notes fields 64bit words (and
> so 8-byte aligned) in ELFCLASS64 would indeed be what gabi
> literally says, but not what GNU systems, and others, follow.
>
> Having a mix of 4-byte words and 8-byte words ELF Notes
> in the same ELF file seems unnecessarily confusing and
> introduces extra segments and sections.
>
> Cheers,
>
> Mark



-- 
H.J.