[PULL 2/7] target/arm: Make sure that commpage's tb->size != 0

[Cornelia Huck]

From: Ilya Leoshkevich <iii@linux.ibm.com>

tb_gen_code() assumes that tb->size must never be zero, otherwise it
may produce spurious exceptions. For ARM this may happen when creating
a translation block for the commpage.

Fix by pretending that commpage translation blocks have at least one
instruction.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210416154939.32404-3-iii@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 target/arm/translate.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 43ff0d4b8ac2..c8dbb03d6db8 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -9097,6 +9097,7 @@ static void arm_tr_translate_insn(DisasContextBase 
*dcbase, CPUState *cpu)
     unsigned int insn;
 
     if (arm_pre_translate_insn(dc)) {
+        dc->base.pc_next += 4;
         return;
     }
 
@@ -9166,6 +9167,7 @@ static void thumb_tr_translate_insn(DisasContextBase 
*dcbase, CPUState *cpu)
     bool is_16bit;
 
     if (arm_pre_translate_insn(dc)) {
+        dc->base.pc_next += 2;
         return;
     }
 
-- 
2.30.2