[PATCH] nptl: Fix abort in case of set*id failure

[Ondřej Bílka]

On Mon, Apr 28, 2014 at 02:03:02PM +0200, Florian Weimer wrote:
> If a call to the set*id functions fails in a multi-threaded program,
> the abort introduced in commit 13f7fe35ae2b0ea55dc4b9628763aafdc8bdc30c
> was triggered.
> 
> We address by checking that all calls to set*id on all threads give
> the same result, and only abort if we see success followed by failure
> (or vice versa).

A code itself makes sense. However I am not familiar with nptl enough to decide
if its proper solution, like why there is not a race condition if other
thread calls setuid that succeeds followed by setuid that fails.