From 0b85ea5f28c4df025bc908fd66aa5a9a66a5f0d5 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 2 Aug 2019 20:56:32 +1000 Subject: [PATCH] powerpc/64s/exception: machine check use correct cfar for late handler [ Upstream commit 0b66370c61fcf5fcc1d6901013e110284da6e2bb ] Bare metal machine checks run an "early" handler in real mode before running the main handler which reports the event. The main handler runs exactly as a normal interrupt handler, after the "windup" which sets registers back as they were at interrupt entry. CFAR does not get restored by the windup code, so that will be wrong when the handler is run. Restore the CFAR to the saved value before running the late handler. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190802105709.27696-8-npiggin@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/exceptions-64s.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 92474227262b..0c8b966e8070 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -467,6 +467,10 @@ EXC_COMMON_BEGIN(machine_check_handle_early) RFI_TO_USER_OR_KERNEL 9: /* Deliver the machine check to host kernel in V mode. */ +BEGIN_FTR_SECTION + ld r10,ORIG_GPR3(r1) + mtspr SPRN_CFAR,r10 +END_FTR_SECTION_IFSET(CPU_FTR_CFAR) MACHINE_CHECK_HANDLER_WINDUP b machine_check_pSeries