https://savannah.gnu.org/bugs/?58829

Index: src/fault-openbsd-powerpc.h
--- src/fault-openbsd-powerpc.h.orig
+++ src/fault-openbsd-powerpc.h
@@ -17,7 +17,14 @@
 
 #include "fault-openbsd.h"
 
-/* See the definition of 'struct sigcontext' and 'struct trapframe' in
-   openbsd-src/sys/arch/powerpc/include/signal.h.  */
+/* For 32-bit PowerPC, see the definition of 'struct sigcontext' and
+ * 'struct trapframe' in openbsd-src/sys/arch/powerpc/include/signal.h.
+ * For 64-bit PowerPC only 'struct sigcontext' is defined in
+ * openbsd-src/sys/arch/power64/include/signal.h.
+ */
 
+#ifdef __powerpc64__
+#define SIGSEGV_FAULT_STACKPOINTER  scp->sc_sp
+#else
 #define SIGSEGV_FAULT_STACKPOINTER  scp->sc_frame.fixreg[1]
+#endif