[PATCH] target/i386: Check NULL monitor pointer when injecting MCE

[Tao Su <tao1.su@linux.intel.com>]

monitor_puts() doesn't check the monitor pointer, but do_inject_x86_mce()
may have a parameter with NULL monitor pointer. Check the monitor pointer
before calling monitor_puts().

Fixes: bf0c50d4aa85 (monitor: expose monitor_puts to rest of code)
Reviwed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
---
 target/i386/helper.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/i386/helper.c b/target/i386/helper.c
index 2070dd0dda..a9ff830a17 100644
--- a/target/i386/helper.c
+++ b/target/i386/helper.c
@@ -430,7 +430,8 @@ static void do_inject_x86_mce(CPUState *cs, run_on_cpu_data data)
         if (need_reset) {
             emit_guest_memory_failure(MEMORY_FAILURE_ACTION_RESET, ar,
                                       recursive);
-            monitor_puts(params->mon, msg);
+            if (params->mon)
+                monitor_puts(params->mon, msg);
             qemu_log_mask(CPU_LOG_RESET, "%s\n", msg);
             qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
             return;
-- 
2.34.1