Re: [PATCH 0/9] [v3] x86, pkeys: two protection keys bug fixes

From: Ram Pai
Date: Mon Apr 30 2018 - 12:28:53 EST

On Mon, Apr 30, 2018 at 08:30:43AM -0700, Dave Hansen wrote:
> On 04/28/2018 12:05 AM, Ingo Molnar wrote:
> > In the above kernel that was missing the PROT_EXEC fix I was repeatedly running
> > the 64-bit and 32-bit testcases as non-root and as root as well, until I got a
> > hang in the middle of a 32-bit test running as root:
> >
> > test 7 PASSED (iteration 19)
> > test 8 PASSED (iteration 19)
> > test 9 PASSED (iteration 19)
> >
> > < test just hangs here >
> For the hang, there is a known issue with the use of printf() in the
> signal handler and a resulting deadlock. I *thought* there was a patch
> merged to fix this from Ram Pai or one of the other IBM folks.

Yes. there is a patch. unfortunately that patch assumes the selftest has
been moved into selftests/vm directory. One option is -- I merge your
changes in my selftest patchset, and send the entire series for upstream

Or you can manually massage-in the specific fix.
The patch is "selftests/vm: Fix deadlock in protection_keys.c"

Let me know,
Ram Pai