Re: [Linux-kselftest-mirror] selftests/x86/fsgsbase_64 test problem

On Fri, Jan 26, 2018 at 7:36 AM, Dan Rue dan.rue@linaro.org wrote:

We've noticed that fsgsbase_64 can fail intermittently with the following error:

    [RUN]   ARCH_SET_GS(0x0) and clear gs, then schedule to 0x1
            Before schedule, set selector to 0x1
            other thread: ARCH_SET_GS(0x1) -- sel is 0x0
    [FAIL]  GS/BASE changed from 0x1/0x0 to 0x0/0x0

This can be reliably reproduced by running fsgsbase_64 in a loop. i.e.

for i in $(seq 1 10000); do ./fsgsbase_64 || break; done

This problem isn't new - I've reproduced it on latest mainline and every release going back to v4.12 (I did not try earlier). This was tested on a Supermicro board with a Xeon E3-1220 as well as an Intel Nuc with an i3-5010U.

Hmm, I can reproduce it, too. I'll look in a bit. -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html