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

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Tao,

On 20/3/24 07:02, Markus Armbruster wrote:
> Tao Su <tao1.su@linux.intel.com> writes:
> 
>> 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)

Missing braces, see QEMU coding style:
https://www.qemu.org/docs/master/devel/style.html#block-structure

>> +                monitor_puts(params->mon, msg);
>>               qemu_log_mask(CPU_LOG_RESET, "%s\n", msg);
>>               qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
>>               return;
> 
> Could instead revert the broken part of commit bf0c50d4aa85:
> 
>    -            monitor_puts(params->mon, msg);
>    +            monitor_printf(params->mon, "%s", msg);
>                 qemu_log_mask(CPU_LOG_RESET, "%s\n", msg);
> 
> Then the fact that we send the same message to monitor and log is again
> more obvious.
> 
> Either way:
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> 
>