Re: [PATCH] powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038

2019-03-14 Thread Michael Ellerman
Arnd Bergmann writes: > On Wed, Mar 13, 2019 at 2:14 PM Michael Ellerman wrote: > >> That causes CLOCK_MONOTONIC to jump ahead by ~4 billion seconds which >> it is not meant to do. Worse, if the time is then set back before the >> Y2038 boundary CLOCK_MONOTONIC will jump backward. >> >> We can fi

Re: [PATCH] powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038

2019-03-13 Thread Arnd Bergmann
On Wed, Mar 13, 2019 at 2:14 PM Michael Ellerman wrote: > That causes CLOCK_MONOTONIC to jump ahead by ~4 billion seconds which > it is not meant to do. Worse, if the time is then set back before the > Y2038 boundary CLOCK_MONOTONIC will jump backward. > > We can fix it simply by storing the full

[PATCH] powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038

2019-03-13 Thread Michael Ellerman
Jakub Drnec reported: Setting the realtime clock can sometimes make the monotonic clock go back by over a hundred years. Decreasing the realtime clock across the y2k38 threshold is one reliable way to reproduce. Allegedly this can also happen just by running ntpd, I have not managed to re