Ubuntu
php5 package

Use __builtin_clzl on POWER

Bug #1458434 reported by Daniel Axtens on 2015-05-25

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	php	Unknown	Unknown	auto-bugs.php.net #69703
	php5 (Ubuntu)	Fix Released	Medium	Unassigned

Bug Description

Zend/zend_alloc.c uses __builtin_clzl in zend_mm_high_bit and zend_mm_low_but, but only if (defined(__arm__) || defined(__aarch64__)). This is overly restrictive: it's also usable if __defined__(__powerpc__).

This causes a bump to speed on POWER systems: previously zend_mm_high_bit shows up on perf reports, with this patch the functions drop out of the profile entirely.

This bug has also been reported upstream (https://bugs.php.net/bug.php?id=69703), but I've sent you this report, along with a `dpkg-source --commit` style patch, in the hopes that you'll pick it up, so that Ubuntu users get the performance improvement sooner.

This patch was built and tested on Vivid, but is applicable to a range of PHP versions.

Tags:

CVE References

Revision history for this message

Daniel Axtens (daxtens) wrote on 2015-05-25:

__builtin_clzl.patch Edit (887 bytes, text/x-diff)

Robie Basak (racb) on 2015-05-26

Changed in php5 (Ubuntu):
status:	New → Triaged
importance:	Undecided → Medium

Hans Joachim Desserud (hjd) on 2015-07-20

tags:

added: patch vivid

Revision history for this message

Ubuntu Foundations Team Bug Bot (crichton) wrote on 2015-07-20:

The attachment "__builtin_clzl.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

Revision history for this message

Robie Basak (racb) wrote on 2015-07-27:

Uploaded 5.6.11+dfsg-1ubuntu1 to Wily which includes this fix from upstream.

If you need a fix for an existing stable release, please comment with a justification against https://wiki.ubuntu.com/StableReleaseUpdates#When and complete steps 1 through 4 in https://wiki.ubuntu.com/StableReleaseUpdates#Procedure - and go ahead with all the steps if you can. Note that that SRU team would need to make a final decision.

Changed in php5 (Ubuntu):
status:	Triaged → Fix Committed

Revision history for this message

Launchpad Janitor (janitor) wrote on 2015-07-27:

This bug was fixed in the package php5 - 5.6.11+dfsg-1ubuntu1

---------------
php5 (5.6.11+dfsg-1ubuntu1) wily; urgency=medium

  * Merge from Debian. Remaining changes:
    - Drop support for firebird, c-client, mcrypt, onig and qdbm as they
      are in universe:
      + d/control: drop Build-Depends on firebird-dev, libc-client-dev,
        libmcrypt-dev, libonig-dev, libqdbm-dev.
      + d/control: drop binary packages php5-imap, php5-interbase and
        php5-mcrypt and their reverse dependencies.
      + d/rules: drop configuration of qdgm, onig, imap, mcrypt.
      + d/rules: drop CONFIGURE_APACHE_ARGS settings since now we don't
        build interbase or firebird.
      + d/modulelist: drop imap, interbase and mcrypt.
    - d/control: switch Build-Depends of netcat-traditional to
      netcat-openbsd as only the latter is in main.
    - d/source_php5.py, d/rules: add apport hook.
  * New upstream version uses __builtin_clzl when __powerpc__ is defined,
    improving performance on POWER systems (LP: #1458434).
  * Drop changes (patches included upstream): CVE-2015-4598.patch,
    CVE-2015-4643.patch, CVE-2015-4644.patch.