Re: [PATCH] xen: Modify domain_crash() to take a print string

[Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>]

On 03/02/2022 13:48, Julien Grall wrote:
> Hi,
>
> On 03/02/2022 13:38, Andrew Cooper wrote:
>> diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
>> index 37f78cc4c4c9..38b390d20371 100644
>> --- a/xen/include/xen/sched.h
>> +++ b/xen/include/xen/sched.h
>> @@ -736,10 +736,15 @@ void vcpu_end_shutdown_deferral(struct vcpu *v);
>>    * from any processor.
>>    */
>>   void __domain_crash(struct domain *d);
>> -#define domain_crash(d) do
>> {                                              \
>> -    printk("domain_crash called from %s:%d\n", __FILE__,
>> __LINE__);       \
>> -   
>> __domain_crash(d);                                                    \
>> -} while (0)
>> +#define domain_crash(d, ...)                            \
>> +    do {                                                \
>> +        if ( count_args(__VA_ARGS__) == 0 )             \
>> +            printk("domain_crash called from %s:%d\n",  \
>> +                   __FILE__, __LINE__);                 \
>
> I find a bit odd that here you are using a normal printk

That's unmodified from before.  Only reformatted.

> but...
>
>
>> +        else                                            \
>> +            printk(XENLOG_G_ERR __VA_ARGS__);           \
>
> here it is XENLOG_G_ERR. In fact, isn't it ratelimited? If so,
> wouldn't it be better to only use XENLOG_ERR so they can always be
> seen? (A domain shouldn't be able to abuse it).

Perhaps.  I suppose it is more important information than pretty much
anything else about the guest.

I've changed locally, but won't repost just for this.

~Andrew