tcg: Restart after TB code generation overflow

If a TB generates too much code, try again with fewer insns.

Fixes: https://bugs.launchpad.net/bugs/1824853
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index c0730f119f..5d255166c0 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -3996,6 +3996,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
         if (unlikely((void *)s->code_ptr > s->code_gen_highwater)) {
             return -1;
         }
+        /* Test for TB overflow, as seen by gen_insn_end_off.  */
+        if (unlikely(tcg_current_code_size(s) > UINT16_MAX)) {
+            return -2;
+        }
     }
     tcg_debug_assert(num_insns >= 0);
     s->gen_insn_end_off[num_insns] = tcg_current_code_size(s);