The translation code uses cpu_ld*_code which can trigger a tlb_fill
which if it fails will erroneously attempts a fault resolution. This
never works during translation as the TB being generated hasn't been
added yet. The target should have checked retaddr before calling
cpu_restore_state but for those that have yet to be fixed we do it
here to avoid a recursive tb_lock() under MTTCG's new locking regime.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
TranslationBlock *tb;
bool r = false;
+ /* A retaddr of zero is invalid so we really shouldn't have ended
+ * up here. The target code has likely forgotten to check retaddr
+ * != 0 before attempting to restore state. We return early to
+ * avoid blowing up on a recursive tb_lock(). The target must have
+ * previously survived a failed cpu_restore_state because
+ * tb_find_pc(0) would have failed anyway. It still should be
+ * fixed though.
+ */
+
+ if (!retaddr) {
+ return r;
+ }
+
tb_lock();
tb = tb_find_pc(retaddr);
if (tb) {