commit f689befde664f917510e842660a69961faf8ba7b
author Ilya Leoshkevich <iii@linux.ibm.com> Fri Apr 16 17:49:38 2021 +0200
committer Cornelia Huck <cohuck@redhat.com> Thu May 20 14:19:30 2021 +0200
tree 071f6b1e6ae26dd6b756bf7c4ba7e95576d6564c
parent 48a130923c59b706e7f33527490028eb8a86b97e

target/xtensa: Make sure that tb->size != 0

tb_gen_code() assumes that tb->size must never be zero, otherwise it
may produce spurious exceptions. For xtensa this may happen when
decoding an unknown instruction, when handling a write into the
CCOUNT or CCOMPARE special register and when single-stepping the first
instruction of an exception handler.

Fix by pretending that the size of the respective translation block is
1 in all these cases.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20210416154939.32404-4-iii@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

target/xtensa/translate.c

diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index 0ae4efc..73584d9d 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -917,6 +917,7 @@
                       "unknown instruction length (pc = %08x)\n",
                       dc->pc);
         gen_exception_cause(dc, ILLEGAL_INSTRUCTION_CAUSE);
+        dc->base.pc_next = dc->pc + 1;
         return;
     }
 
@@ -1274,11 +1275,13 @@
     if ((tb_cflags(dc->base.tb) & CF_USE_ICOUNT)
         && (dc->base.tb->flags & XTENSA_TBFLAG_YIELD)) {
         gen_exception(dc, EXCP_YIELD);
+        dc->base.pc_next = dc->pc + 1;
         dc->base.is_jmp = DISAS_NORETURN;
         return;
     }
     if (dc->base.tb->flags & XTENSA_TBFLAG_EXCEPTION) {
         gen_exception(dc, EXCP_DEBUG);
+        dc->base.pc_next = dc->pc + 1;
         dc->base.is_jmp = DISAS_NORETURN;
         return;
     }