8223266: PPC64: Check for branch to illegal address before checking for mem serialization
Reviewed-by: goetz, mdoerr
diff --git a/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
index e7d2e9c..1939fb6 100644
--- a/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
+++ b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
@@ -1,6 +1,6 @@
/*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2018 SAP SE. All rights reserved.
+ * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -500,8 +500,10 @@
// It write enables the page immediately after protecting it
// so we can just return to retry the write.
if ((sig == SIGSEGV) &&
- // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above).
- // Use is_memory_serialization instead of si_addr.
+ // si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comments above).
+ // So first check if it's indeed a "Data Storage Interrupt" (DSI), caused by load/store,
+ // and only then use is_memory_serialization instead of si_addr.
+ (ucontext_get_trap(uc) & 0x0F00 == 0x0300) &&
((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) {
// Synchronization problem in the pseudo memory barrier code (bug id 6546278)
// Block current thread until the memory serialize page permission restored.
