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

[Markus Armbruster <armbru@redhat.com>]

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)
> +                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>