[PATCH AUTOSEL 4.20 250/304] ACPI/APEI: Clear GHES block_status before panic()

From: Sasha Levin
Date: Mon Jan 28 2019 - 10:56:15 EST

From: Lenny Szubowicz <lszubowi@xxxxxxxxxx>

[ Upstream commit 98cff8b23ed1c763a029ee81ea300df0d153d07d ]

In __ghes_panic() clear the block status in the APEI generic
error status block for that generic hardware error source before
calling panic() to prevent a second panic() in the crash kernel
for exactly the same fatal error.

Otherwise ghes_probe(), running in the crash kernel, would see
an unhandled error in the APEI generic error status block and
panic again, thereby precluding any crash dump.

Signed-off-by: Lenny Szubowicz <lszubowi@xxxxxxxxxx>
Signed-off-by: David Arcari <darcari@xxxxxxxxxx>
Tested-by: Tyler Baicar <baicar.tyler@xxxxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/acpi/apei/ghes.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 02c6fd9caff7..f008ba7c9ced 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -691,6 +691,8 @@ static void __ghes_panic(struct ghes *ghes)
__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);

+ ghes_clear_estatus(ghes);
/* reboot to log the error! */
if (!panic_timeout)
panic_timeout = ghes_panic_timeout;