[PATCH v2 1/3] drm: Create an app info option for wedge events

[Christian König]

On 5/12/25 08:08, Krzysztof Karas wrote:
> Hi André,
> 
> [...]
> 
>> @@ -582,6 +584,14 @@ int drm_dev_wedged_event(struct drm_device *dev, unsigned long method)
>>  	drm_info(dev, "device wedged, %s\n", method == DRM_WEDGE_RECOVERY_NONE ?
>>  		 "but recovered through reset" : "needs recovery");
>>  
>> +	if (info) {
>> +		snprintf(pid_string, sizeof(pid_string), "PID=%u", info->pid);
>> +		snprintf(comm_string, sizeof(comm_string), "APP=%s", info->comm);
>> +	} else {
>> +		snprintf(pid_string, sizeof(pid_string), "%s", "PID=-1");
>> +		snprintf(comm_string, sizeof(comm_string), "%s", "APP=none");
> 
> I think using PID=-1 and APP=none might be misleading, because
> something did cause the wedge if we landed here.

Yeah, that certainly won't fly. 1 is a perfectly valid pid.

I would just set pid_string and comm_string to empty if info isn't available.

Regards,
Christian.


 You could use
> "PID=unknown" and "APP=unknown" or ensure these arrays are
> zeroed and fill them only if "info" is available:
> 
> -     char *envp[] = { event_string, NULL };
> +     char pid_string[15] = {}, comm_string[TASK_COMM_LEN] = {};
> +     char *envp[] = { event_string, pid_string, comm_string, NULL };
> 
> [...]
> 
> +     if (info) {
> +             snprintf(pid_string, sizeof(pid_string), "PID=%u", info->pid);
> +             snprintf(comm_string, sizeof(comm_string), "APP=%s", info->comm);
> +     }
> 
> Then, when printing the logs later you could check if they have
> a value and only use them if they do (or handle that however
> you would see fit :) ).
> 
> Best Regards,
> Krzysztof