From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH v3 13/23] XENVER_build_id: Provide
 ld-embedded build-ids (v10)
Date: Wed, 24 Feb 2016 19:13:11 +0000
Message-ID: <56CE00C7.9000808@citrix.com>
References: <1455300361-13092-1-git-send-email-konrad.wilk@oracle.com>
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To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.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 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

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

~Andrew