target/m68k: fix set_cc_op()

The first call of set_cc_op() in a new translation sequence
is done with old_op set to CC_OP_DYNAMIC (-1).

This will do an out of bound access to the array cc_op_live[].

We fix that by adding an entry in cc_op_live[] for CC_OP_DYNAMIC.

Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20171221160558.14151-1-laurent@vivier.eu>

diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index afae5f6..5d03764 100644 (file)
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -182,7 +182,7 @@ void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val);
  */
 typedef enum {
     /* Translator only -- use env->cc_op.  */
-    CC_OP_DYNAMIC = -1,
+    CC_OP_DYNAMIC,
 
     /* Each flag bit computed into cc_[xcnvz].  */
     CC_OP_FLAGS,

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index dfb2d5d..bbda739 100644 (file)
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -202,6 +202,7 @@ typedef void (*disas_proc)(CPUM68KState *env, DisasContext *s, uint16_t insn);
 #endif
 
 static const uint8_t cc_op_live[CC_OP_NB] = {
+    [CC_OP_DYNAMIC] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X,
     [CC_OP_FLAGS] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X,
     [CC_OP_ADDB ... CC_OP_ADDL] = CCF_X | CCF_N | CCF_V,
     [CC_OP_SUBB ... CC_OP_SUBL] = CCF_X | CCF_N | CCF_V,