linux-user/openrisc: Abort for EXCP_RANGE, EXCP_FPE

QEMU does not allow the system control bits for either exception to
be enabled in linux-user, therefore both exceptions are dead code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/openrisc/cpu_loop.c

@@ -56,7 +56,6 @@ void cpu_loop(CPUOpenRISCState *env)
             break;
         case EXCP_DPF:
         case EXCP_IPF:
-        case EXCP_RANGE:
             info.si_signo = TARGET_SIGSEGV;
             info.si_errno = 0;
             info.si_code = TARGET_SEGV_MAPERR;
@@ -77,13 +76,6 @@ void cpu_loop(CPUOpenRISCState *env)
             info._sifields._sigfault._addr = env->pc;
             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
             break;
-        case EXCP_FPE:
-            info.si_signo = TARGET_SIGFPE;
-            info.si_errno = 0;
-            info.si_code = 0;
-            info._sifields._sigfault._addr = env->pc;
-            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
-            break;
         case EXCP_INTERRUPT:
             /* We processed the pending cpu work above.  */
             break;
@@ -96,6 +88,15 @@ void cpu_loop(CPUOpenRISCState *env)
         case EXCP_ATOMIC:
             cpu_exec_step_atomic(cs);
             break;
+        case EXCP_RANGE:
+            /* Requires SR.OVE set, which linux-user won't do. */
+            cpu_abort(cs, "Unexpected RANGE exception");
+        case EXCP_FPE:
+            /*
+             * Requires FPSCR.FPEE set.  Writes to FPSCR from usermode not
+             * yet enabled in kernel ABI, so linux-user does not either.
+             */
+            cpu_abort(cs, "Unexpected FPE exception");
         default:
             g_assert_not_reached();
         }