[SRU] Patch power9-001.diff breaks IFUNC on ELFv1

[Adam Conrad]

[ SRU Justification ]
As per comment #4 in https://bugs.launchpad.net/ubuntu/+source/binutils/+bug/1655181 the undefined weak fix should not have been backported because it breaks IFUNC on ELFv1, and can't be fixed without a much larger backport from 2.27. This patch breaks glibc builds on PPC64 ELFv1.

See also https://sourceware.org/bugzilla/show_bug.cgi?id=20472

I will be pushing this upload via the ubuntu-security-proposed PPA, as this regression also exists in security and if we ever want to do a glibc security update, we need the fix there as well.

[ Test Case ]
See that glibc now builds on powerpc in xenial, when it didn't with the previous version.

[ Regression Potential ]
We lived fine without this patch before, and will do again in the future. Removing it fixes ELFv1 glibc builds (and presumably anything else that uses IFUNC), but should have no other obvious impact.

[Brian Murray (brian-murray)]

Hello Adam, or anyone else affected,

Accepted binutils into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/binutils/2.26.1-1ubuntu1~16.04.8 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Adam Conrad (adconrad)]

glibc has built successfully on powerpc with this new binutils

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for binutils has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package binutils - 2.26.1-1ubuntu1~16.04.8

---------------
binutils (2.26.1-1ubuntu1~16.04.8) xenial; urgency=medium

  * power9-001.diff: Drop this patch as it breaks IFUNC on ELFv1 (LP: #1807448)

 -- Adam Conrad <email address hidden> Fri, 07 Dec 2018 12:49:49 -0700