From 0b66370c61fcf5fcc1d6901013e110284da6e2bb Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Fri, 2 Aug 2019 20:56:32 +1000
Subject: [PATCH] powerpc/64s/exception: machine check use correct cfar for
late handler
References: jsc#PM-1334 jsc#SLE-9246 jsc#SLE-9251 bnc#1151927 5.3.5
Patch-mainline: v5.4-rc1
Git-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 <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-8-npiggin@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
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 577d93a83d05..b7c4149cb91c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1186,6 +1186,10 @@ FTR_SECTION_ELSE
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE)
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
EXCEPTION_PROLOG_0 PACA_EXMC
EXCEPTION_PROLOG_1 EXC_STD, PACA_EXMC, 1, 0x200, 1, 1, 0
--
2.23.0