opal: Deprecate reading the PHB status

The OPAL_PCI_EEH_FREEZE_STATUS call takes a bunch of parameters, one of
them is @phb_status. It is defined as __be64* and always NULL in
the current Linux upstream but if anyone ever decides to read that status,
then the PHB3's handler will assume it is struct OpalIoPhb3ErrorData*
(which is a lot bigger than 8 bytes) and zero it causing the stack
corruption; p7ioc-phb has the same issue.

This removes @phb_status from all eeh_freeze_status() hooks and moves
the error message from PHB4 to the affected OPAL handlers.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-By: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/hw/npu2.c b/hw/npu2.c
index f034490..0a7b157 100644
--- a/hw/npu2.c
+++ b/hw/npu2.c
@@ -1274,8 +1274,7 @@ int64_t npu2_freeze_status(struct phb *phb __unused,
 			   uint64_t pe_number __unused,
 			   uint8_t *freeze_state,
 			   uint16_t *pci_error_type,
-			   uint16_t *severity,
-			   uint64_t *phb_status __unused)
+			   uint16_t *severity)
 {
 	/*
 	 * FIXME: When it's called by skiboot PCI config accessor,