[RESEND PATCH v3 2/2] powernv: Fix MCE handler to avoid trashing CR0/CR1 registers.

Michael Ellerman mpe at ellerman.id.au
Mon Aug 8 18:58:12 AEST 2016

Mahesh J Salgaonkar <mahesh at linux.vnet.ibm.com> writes:

> From: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
> The current implementation of MCE early handling modifies CR0/1 registers
> without saving its old values. Fix this by moving early check for
> powersaving mode to machine_check_handle_early().
> The power architecture 2.06 or later allows the possibility of getting
> machine check while in nap/sleep/winkle. The last bit of HSPRG0 is set
> to 1, if thread is woken up from winkle. Hence, clear the last bit of
> HSPRG0 (r13) before MCE handler starts using it as paca pointer.
> Also, the current code always puts the thread into nap state irrespective
> of whatever idle state it woke up from. Fix that by looking at
> paca->thread_idle_state and put the thread back into same state where it
> came from.
> Cc: stable at vger.kernel.org

The information I need is "which commit introduced the bug".

Given that I can work out which stable releases we should backport the
patch to.


More information about the Linuxppc-dev mailing list