exec: Delay CPU_LOG_TB_CPU until we actually execute a TB

The previous placement could result in duplicate logging while
still processing interrupts.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

cpu-exec.c

@@ -53,7 +53,25 @@ void cpu_resume_from_signal(CPUArchState *env, void *puc)
 static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr)
 {
     CPUArchState *env = cpu->env_ptr;
-    uintptr_t next_tb = tcg_qemu_tb_exec(env, tb_ptr);
+    uintptr_t next_tb;
+
+#if defined(DEBUG_DISAS)
+    if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) {
+#if defined(TARGET_I386)
+        log_cpu_state(cpu, CPU_DUMP_CCOP);
+#elif defined(TARGET_M68K)
+        /* ??? Should not modify env state for dumping.  */
+        cpu_m68k_flush_flags(env, env->cc_op);
+        env->cc_op = CC_OP_FLAGS;
+        env->sr = (env->sr & 0xffe0) | env->cc_dest | (env->cc_x << 4);
+        log_cpu_state(cpu, 0);
+#else
+        log_cpu_state(cpu, 0);
+#endif
+    }
+#endif /* DEBUG_DISAS */
+
+    next_tb = tcg_qemu_tb_exec(env, tb_ptr);
     if ((next_tb & TB_EXIT_MASK) > TB_EXIT_IDX1) {
         /* We didn't start executing this TB (eg because the instruction
          * counter hit zero); we must restore the guest PC to the address
@@ -579,22 +597,6 @@ int cpu_exec(CPUArchState *env)
                     env->exception_index = EXCP_INTERRUPT;
                     cpu_loop_exit(env);
                 }
-#if defined(DEBUG_DISAS)
-                if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) {
-                    /* restore flags in standard format */
-#if defined(TARGET_I386)
-                    log_cpu_state(cpu, CPU_DUMP_CCOP);
-#elif defined(TARGET_M68K)
-                    cpu_m68k_flush_flags(env, env->cc_op);
-                    env->cc_op = CC_OP_FLAGS;
-                    env->sr = (env->sr & 0xffe0)
-                              | env->cc_dest | (env->cc_x << 4);
-                    log_cpu_state(cpu, 0);
-#else
-                    log_cpu_state(cpu, 0);
-#endif
-                }
-#endif /* DEBUG_DISAS */
                 spin_lock(&tcg_ctx.tb_ctx.tb_lock);
                 tb = tb_find_fast(env);
                 /* Note: we do it here to avoid a gcc bug on Mac OS X when