[Bug 491872] Re: [armel] Atomic intrinsics are not implemented correctly

[Bug Watch Updater]

** Changed in: gcc
   Importance: Unknown => High

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to gcc-4.4 in Ubuntu.
https://bugs.launchpad.net/bugs/491872

Title:
  [armel] Atomic intrinsics are not implemented correctly

Status in The GNU Compiler Collection:
  Fix Released
Status in “gcc-4.4” package in Ubuntu:
  Fix Released
Status in “glib2.0” package in Ubuntu:
  Fix Released

Bug description:
  Binary package hint: gcc-4.4

  Observed in gcc 4.4.2-3ubuntu1
  Believed to affect all versions

  __sync_synchronnize() should perform a memory barrier, but is a noop (at least with -O2)
  __sync_lock_release() should place a memory barrier before the compare-exchange operation, but actually puts the barrier after, which may cause unsafe spinlock release

  Implications: packages built with unfixed gcc which use these
  intrinsics may not be multicore-safe on armel.

  Upstream bug link and further information to follow shortly, when
  available.

To manage notifications about this bug go to:
https://bugs.launchpad.net/gcc/+bug/491872/+subscriptions