F35 Change: libffi 3.4 (late System-Wide Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/LIBFFI34

== Summary ==
Rebase libffi in Fedora 34 from libffi 3.1 to libffi 3.4 (released
June 28 2021), and provide a libffi3.1 compatibility package to handle
the library SONAME transition.

== Owner ==
* Name: [[User:codonell| Carlos O'Donell]]
* Email: carlos(a)redhat.com


== Detailed Description ==
Libffi 3.4 was released in June 28 2021 after a long period of
upstream testing supported directly by Fedora (DJ Delorie).  Intel
Control-flow Enforcement Technology support has been added, which is a
desirable feature for Fedora.  Fedora is currently using libffi 3.1,
released in 2014.

This change will require a SONAME bump due to ABI changes. A libffi3.1
package has been prepared, and tested in a side-tag along with libffi
3.4, and supports a smooth transition between existing binaries and
binaries using the new library. No package needs to be rebuilt, old
packages will require and install the compat libffi3.1 package.

The libffi3.1 package would enter the distribution first, followed by
libffi updated to version 3.4. Again, no packages need to be rebuilt
for the transition to happen.


== Benefit to Fedora ==
Stay up to date with upstream libffi, including bug fixes et al.

Stay compatible with other distros which have updated already.

Add support for Intel CET and Power10.

== Scope ==
* Proposal owners: Update to libffi 3.4
* Other developers: Packages which link against libffi do not need to
be rebuilt.  Depending on your API usage, some code changes might be
required after the update, but existing builds will continue to work.
* Release engineering:
* Policies and guidelines: The policies and guidelines do not need to
be updated.
* Trademark approval: N/A (not needed for this Change)
* Alignment with Objectives: None


== Upgrade/compatibility impact ==
Packages built on the previous version of libffi will have an
auto-requires on the old SONAME and will cause dnf to install
libffi3.1 (compat package with runtime). When packages are rebuilt
against libffi 3.4 they will automatically switch to using the new
SONAME.

libffi's latest static trampolines feature has been disabled because
it has an impact on


== How To Test ==
libffi includes its own testsuite.  A side-tag rebuild has been
carried out to rebuild dependent packages and verify their correct
operation, this includes:

* python3.9
* dnf
* gobject-introspection
* glib2
* p11-kit
* rubygem-ffi
* guile22
* git-annex
* php
* llvm

Correct operation of these packages was verified by reviewing testsuite results.

== User Experience ==
The new version of libffi, aside from the usual internal bugfixes and
tweaks, introduces support for Intel CET and Power10.

== Dependencies ==
The key dependencies for libffi are python and dnf. Correct operation
of python and dnf during the transition requires the libffi3.1 compat
package to allow a smooth rebuild path from one SONAME to the next.
Verification of this was carried out in a side-tag in Fedora Rawhide.

== Contingency Plan ==
* Contingency mechanism: Revert to libffi 3.1 (dropping libffi3.1 and
the libffi 3.4 update)
* Contingency deadline: 2021-08-24
* Blocks release? No
* Blocks product? N/A

== Documentation ==
libffi includes its own documentation.  No additional documentation
work is required.

== Release Notes ==

libffi does not public formal release notes.  A change list can be
found in libffi's git history:
https://github.com/libffi/libffi/commits/master

-- 
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis

[Samuel Sieb]

On 7/14/21 11:28 AM, Ben Cotton wrote:
>  == Upgrade/compatibility impact ==
>  Packages built on the previous version of libffi will have an
>  auto-requires on the old SONAME and will cause dnf to install
>  libffi3.1 (compat package with runtime). When packages are rebuilt
>  against libffi 3.4 they will automatically switch to using the new
>  SONAME.
>  
>  libffi's latest static trampolines feature has been disabled because
>  it has an impact on 
Looks like this section got cut off.

[Carlos O'Donell]

On 7/14/21 2:33 PM, Samuel Sieb wrote:
>  On 7/14/21 11:28 AM, Ben Cotton wrote:
> > == Upgrade/compatibility impact ==
> > Packages built on the previous version of libffi will have an
> > auto-requires on the old SONAME and will cause dnf to install
> > libffi3.1 (compat package with runtime). When packages are rebuilt
> > against libffi 3.4 they will automatically switch to using the new
> > SONAME.
> >
> > libffi's latest static trampolines feature has been disabled because
> > it has an impact on
>  
>  Looks like this section got cut off. 
Sorry. Updated.

Thee static templates impact gobject-introspection and ghc.

-- 
Cheers,
Carlos.

[Michael Catanzaro]

On Wed, Jul 14 2021 at 02:28:50 PM -0400, Ben Cotton 
<bcotton(a)redhat.com&gt; wrote:
>  Rebase libffi in Fedora 34 
Is this a typo? F34 or F35?

[Carlos O'Donell]

On 7/14/21 3:00 PM, Michael Catanzaro wrote:
>  On Wed, Jul 14 2021 at 02:28:50 PM -0400, Ben Cotton
> <bcotton(a)redhat.com&gt; wrote:
> > Rebase libffi in Fedora 34
>  
>  Is this a typo? F34 or F35? 
Sorry. Fixed. Typo.

We've been carrying this change proposal since F34 as we work with
upstream to release libffi 3.4.

-- 
Cheers,
Carlos.

[Zbigniew Jędrzejewski-Szmek]

On Wed, Jul 14, 2021 at 02:28:50PM -0400, Ben Cotton wrote:
>  https://fedoraproject.org/wiki/Changes/LIBFFI34
>  
>  == Summary ==
>  Rebase libffi in Fedora 34 from libffi 3.1 to libffi 3.4 (released
>  June 28 2021), and provide a libffi3.1 compatibility package to handle
>  the library SONAME transition. 
The usual: please don't say "rebase" in public-facing documents.
It's packaging jargon that is not clear to users.

Looks all reasonable… With the compat package, this should be very
smooth.

>  == Release Notes ==
>  
>  libffi does not public formal release notes.  A change list can be
>  found in libffi's git history:
>  https://github.com/libffi/libffi/commits/master 
Those sentences are slightly garbled too.

Zbyszek

[Carlos O'Donell]

On 7/15/21 6:52 AM, Zbigniew Jędrzejewski-Szmek wrote:
>  On Wed, Jul 14, 2021 at 02:28:50PM -0400, Ben Cotton wrote:
> > https://fedoraproject.org/wiki/Changes/LIBFFI34
> >
> > == Summary ==
> > Rebase libffi in Fedora 34 from libffi 3.1 to libffi 3.4 (released
> > June 28 2021), and provide a libffi3.1 compatibility package to handle
> > the library SONAME transition.
>  
>  The usual: please don't say "rebase" in public-facing documents.
>  It's packaging jargon that is not clear to users. 
Switched to "Update" since that's what we're doing.

Thanks for the feedback! I've been filing system-wide change requests for
years with glibc, and I was never quite sure of the exact audience that
might be reading them.

I'll try to make the text more "user friendly" in the future. I certainly
appreciate the feedback.

>  Looks all reasonable… With the compat package, this should be very
>  smooth. 
I agree, the compat package is required, it really makes the whole
transition very smooth.
 
> > == Release Notes ==
> >
> > libffi does not public formal release notes.  A change list can be
> > found in libffi's git history:
> > https://github.com/libffi/libffi/commits/master
>  
>  Those sentences are slightly garbled too. 
Upstream is providing release notes.

I've updated them to list the important notes for Fedora users.

Many will be happy about the RISC-V support.

-- 
Cheers,
Carlos.

[Zbigniew Jędrzejewski-Szmek]

On Thu, Jul 15, 2021 at 02:28:20PM -0400, Carlos O'Donell wrote:
>  On 7/15/21 6:52 AM, Zbigniew Jędrzejewski-Szmek wrote:
>  > On Wed, Jul 14, 2021 at 02:28:50PM -0400, Ben Cotton wrote:
>  >> https://fedoraproject.org/wiki/Changes/LIBFFI34
>  >>
>  >> == Summary ==
>  >> Rebase libffi in Fedora 34 from libffi 3.1 to libffi 3.4 (released
>  >> June 28 2021), and provide a libffi3.1 compatibility package to handle
>  >> the library SONAME transition.
>  > 
>  > The usual: please don't say "rebase" in public-facing documents.
>  > It's packaging jargon that is not clear to users.
>  
>  Switched to "Update" since that's what we're doing.
>  
>  Thanks for the feedback! I've been filing system-wide change requests for
>  years with glibc, and I was never quite sure of the exact audience that
>  might be reading them. 
I think nobody knows the exact audience, except that it's certainly
very varied. For example, phoronix is a popular website and it often
releases article directly based on the change text. This is pretty
clear in the list of articles about F34 [1]. We also know that sometimes
the change page lives on, like the merged-usr page [2], which is still
being cited regularly. So I think getting the texts on those pages
approachable and clear is very important.

[1] https://www.phoronix.com/scan.php?page=search&q=Fedora+34
[2] https://fedoraproject.org/wiki/Features/UsrMove

Zbyszek

[Jerry James]

On Thu, Jul 15, 2021 at 12:31 PM Carlos O'Donell <carlos(a)redhat.com&gt; wrote:
>  On 7/15/21 6:52 AM, Zbigniew Jędrzejewski-Szmek wrote:
>  > On Wed, Jul 14, 2021 at 02:28:50PM -0400, Ben Cotton wrote:
>  >> == Release Notes ==
>  >>
>  >> libffi does not public formal release notes.  A change list can be
>  >> found in libffi's git history:
>  >> https://github.com/libffi/libffi/commits/master
>  >
>  > Those sentences are slightly garbled too.
>
>  Upstream is providing release notes. 
I think he is referring to the use of "public" where "publish" is the
correct word.
-- 
Jerry James
http://www.jamezone.org/

[Ben Cotton]

On Wed, Jul 14, 2021 at 2:28 PM Ben Cotton <bcotton(a)redhat.com&gt; wrote:
>  https://fedoraproject.org/wiki/Changes/LIBFFI34
>  
This proposal has been deferred to Fedora Linux 36.

-- 
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis