On Fri, 2016-05-08 at 13:43:12 UTC, Mahesh Salgaonkar wrote: > From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com> > > The function pnv_restore_hyp_resource() loads the TOC into r2 from > the invalid PACA pointer before fixing r13 value. This do not affect > POWER ISA 3.0 but it does have an impact on POWER ISA 2.07 or less > leading CPU to get stuck forever. > > login: [ 471.830433] Processor 120 is stuck. > > > This can be easily reproducible using following steps: > - Turn off SMT > $ ppc64_cpu --smt=off > - offline/online any online cpu (Thread 0 of any core which is online) > $ echo 0 > /sys/devices/system/cpu/cpu<num>/online > $ echo 1 > /sys/devices/system/cpu/cpu<num>/online > > For POWER ISA 2.07 or less, the last bit of HSPRG0 is set indicating > that thread is waking up from winkle. Hence, the last bit of HSPRG0(r13) > needs to be clear before accessing it as PACA to avoid loading invalid > values from invalid PACA pointer. > > Fix this by loading TOC after r13 register is corrected. > > Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/e325d76f8bd2d222a1f577aba0 cheers
