From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [PATCH v3 13/23] XENVER_build_id: Provide
 ld-embedded build-ids (v10)
Date: Wed, 24 Feb 2016 15:54:58 -0500
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To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, jinsong.liu@alibaba-inc.com, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, xen-devel@lists.xen.org, mpohlack@amazon.de, ross.lagerwall@citrix.com, Stefano Stabellini <stefano.stabellini@citrix.com>, Jan Beulich <jbeulich@suse.com>, xen-devel@lists.xenproject.org, Daniel De Graaf <dgdegra@tycho.nsa.gov>, Keir Fraser <keir@xen.org>, sasha.levin@citrix.com
List-Id: xen-devel@lists.xenproject.org

On Wed, Feb 24, 2016 at 07:13:11PM +0000, Andrew Cooper wrote:
> On 24/02/16 18:52, Konrad Rzeszutek Wilk wrote:
> >>> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> >>> index f501a2f..5cf180f 100644
> >>> --- a/xen/arch/arm/xen.lds.S
> >>> +++ b/xen/arch/arm/xen.lds.S
> >>> @@ -22,6 +22,9 @@ OUTPUT_ARCH(FORMAT)
> >>>  PHDRS
> >>>  {
> >>>    text PT_LOAD /* XXX should be AT ( XEN_PHYS_START ) */ ;
> >>> +#if defined(BUILD_ID)
> >>> +  note PT_NOTE ;
> >>> +#endif
> >>>  }
> >>>  SECTIONS
> >>>  {
> >>> @@ -53,6 +56,16 @@ SECTIONS
> >>>          _erodata = .;          /* End of read-only data */
> >>>    } :text
> >>>  
> >>> +#if defined(BUILD_ID)
> >>> +  .note : {
> >>> +       __note_gnu_build_id_start = .;
> >>> +       *(.note.gnu.build-id)
> >>> +       __note_gnu_build_id_end = .;
> >>> +       *(.note)
> >>> +       *(.note.*)
> >>> +  } :text
> >>> +#endif
> >> This data really should be contained inside rodata.
> > I get (I replace :text with :rodata) and got:
> > ld: section `.note' assigned to non-existent phdr `rodata'
> >
> > Which makes sense as there are only two PHDRS. Where you suggesting that
> > the .note should be part of the .rodata section? Jan wanted this to be
> > in its own section (.note).
> >
> > Are you suggesting to add another one PHDR? (If so, then mkelf32 has to be modified,
> > and for EFI I think it will have to have some #ifdef machinery to make it work).
> 
> I was just suggesting moving _erodata down a little to cover .note

Which oddly enough is only in ARM builds. Done!

> 
> Whatever happens patching-wise, this build ID is constant and will want
> to remain so.
> 
> ~Andrew