{
char *name;
+ /* We shouldn't even bother to try if the OSABI didn't register
+ a sigcontext_addr handler. */
+ if (!gdbarch_tdep (current_gdbarch)->sigcontext_addr)
+ return NULL;
+
find_pc_partial_function (pc, &name, NULL, NULL);
if (PC_IN_SIGTRAMP (pc, name))
return &i386_sigtramp_frame_unwind;