Re: ubsan and Dejagnu not having a big enough buffer in some cases

[Jeff Law <law at redhat dot com>]

On 07/20/2016 03:09 PM, Andrew Pinski wrote:
> On Wed, Jul 20, 2016 at 2:02 PM, Andrew Pinski <pinskia@gmail.com> wrote:
> > On Wed, Jul 20, 2016 at 1:32 PM, Jeff Law <law@redhat.com> wrote:
> > > On 07/20/2016 02:21 PM, Segher Boessenkool wrote:
> > > > On Wed, Jul 20, 2016 at 12:48:09PM +0530, Senthil Kumar Selvaraj wrote:
> > > > > > I see this for some of the larger C frontend tests with lots of expected
> > > > > > errors/warnings as well.
> > > >
> > > >
> > > > I also see this for tests with small output, but it happens more
> > > > often for tests with big output.
> > > >
> > > > > Are you guys getting this everytime or is it sporadic?
> > > >
> > > >
> > > > Not always, but usually.  It seems related to how busy the system is,
> > > > but that could be my imagination.
> > > >
> > > > It usually happens for a bunch of tests at the same time.
> > > >
> > > > Not always is the output just cut short: some random characters
> > > > are inserted sometimes (in the individual log files, the consolidated
> > > > log file does not have those; it looks like pointers).
> > >
> > > Hmm, there was a kernel bug a while back which had similar behavior. What
> > > kernel version are you running?
> >
> > I am running with 4.2.  Let me find the old email and see I should
> > include it in our tree (I thought we did).
>
> Found it.  It looks like it was not put in yet:
> https://bugzilla.kernel.org/show_bug.cgi?id=96311
>
> I know Jakub asked about a year ago saying it was not 4.1-rc1 yet.
> Can someone look to see if it even made it into newer kernels?
I know "a" fix is in modern Fedora kernels and I thought it came from 
upstream.

Jeff