From: "H.J. Lu" <hjl.tools@gmail.com>
To: Mark Wielaard <mark@klomp.org>
Cc: Fangrui Song <i@maskray.me>, Cary Coutant <ccoutant@gmail.com>,
"Zhang, Annita" <annita.zhang@intel.com>,
"Liu, Hongtao" <hongtao.liu@intel.com>,
gnu-gabi <gnu-gabi@sourceware.org>,
Binutils <binutils@sourceware.org>
Subject: Re: binutils ld and new PT_GNU_PROPERTY segment
Date: Wed, 01 Jan 2020 00:00:00 -0000 [thread overview]
Message-ID: <CAMe9rOpWbU=rMb62mgqLFsHFTHfq8VQO7BfG4Codkrqh_b1x5Q@mail.gmail.com> (raw)
In-Reply-To: <f661f98effcc200f28c3e64e6bc40bb5ae60c5a5.camel@klomp.org>
On Thu, Feb 20, 2020 at 1:37 AM Mark Wielaard <mark@klomp.org> wrote:
>
> Hi,
>
> On Wed, 2020-02-19 at 14:17 -0800, H.J. Lu wrote:
> > On Wed, Feb 19, 2020 at 1:46 PM Mark Wielaard <mark@klomp.org> wrote:
> > > This code isn't in the kernel yet. So either it gets changed to use the
> > > existing scheme with gnu property notes found through PT_NOTE to work
> > > with existing binaries. Then there is no need for PT_GNU_PROPERTY
> > > headers.
> > >
> > > Or some future kernel will start using PT_GNU_PROPERTY headers to find
> > > the gnu property notes. But that means it won't work with existing
> > > binaries that do not have that header. So there is no backwards
> > > compatibility anyway and we can define SHT_GNU_PROPERTY like above.
> > >
> > > So this actually seems the perfect time to make this decision.
> >
> > Binaries with .note.gnu.property section have been put into many
> > OS releases. We must support them.
>
> OK. Then it is option 1. The kernel will need to support PT_NOTE for
> parsing the properties, since such older binaries won't have a
> PT_GNU_PROPERTY program header. Then we can simply get rid of
> PT_GNU_PROPERTY since nobody uses it and all information is already
> available through the PT_NOTE segment.
>
Kernel loader only checks ld.so and static executable. Re-link them with
newer linker will get PT_GNU_PROPERTY. But ld.so needs to check
PT_NOTE for older binaries.
--
H.J.
next prev parent reply other threads:[~2020-02-20 11:51 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-01 0:00 Mark Wielaard
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` Fangrui Song via gnu-gabi
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Fangrui Song
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` H.J. Lu [this message]
2020-01-01 0:00 ` Fangrui Song
2020-01-01 0:00 ` H.J. Lu
2020-01-01 0:00 ` Mark Wielaard
2020-01-01 0:00 ` Fangrui Song
2020-04-01 8:46 ` Florian Weimer
2020-04-01 9:22 ` Szabolcs Nagy
2020-04-01 9:29 ` Florian Weimer
2020-04-01 10:10 ` Szabolcs Nagy
2020-04-01 10:21 ` Florian Weimer
2020-01-01 0:00 ` Zhang, Annita
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