Fix sem_post race (bug 14532)

[Chris Metcalf]

On 8/30/2012 5:09 PM, Joseph S. Myers wrote:
> Bug 14532 is a race condition in sem_post (generic C version), where
> it wrongly uses an acquire barrier rather than a release barrier, so
> wrongly allowing memory operations from before the unlock to be moved
> after it.
>
> This patch fixes this in the obvious way and adds a testcase.  Tested
> mips64.

This bug is also present on tilegx, and fixed by your patch.

-- 
Chris Metcalf, Tilera Corp.
http://www.tilera.com