From: Richard Henderson <richard.henderson@linaro.org>

This pointer needs to be reset after overflow just like
code_buf and code_ptr.

Cc: qemu-stable@nongnu.org
Fixes: 57a269469db ("tcg: Infrastructure for managing constant pools")
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
(cherry picked from commit a7cfd751fb269de4a93bf1658cb13911c7ac77cc)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 436fcf6ebd..e7aa02c447 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -716,7 +716,6 @@ TranslationBlock *tcg_tb_alloc(TCGContext *s)
         goto retry;
     }
     qatomic_set(&s->code_gen_ptr, next);
-    s->data_gen_ptr = NULL;
     return tb;
 }
 
@@ -4249,6 +4248,7 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb, target_ulong pc_start)
      */
     s->code_buf = tcg_splitwx_to_rw(tb->tc.ptr);
     s->code_ptr = s->code_buf;
+    s->data_gen_ptr = NULL;
 
 #ifdef TCG_TARGET_NEED_LDST_LABELS
     QSIMPLEQ_INIT(&s->ldst_labels);
-- 
2.39.5