# Re: \[PATCH\] vsprintf: Do not break early boot with probing addresses

- From: christophe leroy \<hidden\>
- Date: 2019-05-10 17:35:42 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2019/05/5594238
- Thread: https://ratatoskr.run/linuxppc-dev/2019/05/5592853/t.md

```text


Le 10/05/2019 à 18:24, Steven Rostedt a écrit :
> On Fri, 10 May 2019 10:42:13 +0200
> Petr Mladek [ref] wrote:
>
>>   static const char *check_pointer_msg(const void *ptr)
>>   {
>> -	char byte;
>> -
>>   	if (!ptr)
>>   		return "(null)";
>>   
>> -	if (probe_kernel_address(ptr, byte))
>> +	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
>>   		return "(efault)";
>>   
>
>
> 	< PAGE_SIZE ?
>
> do you mean: < TASK_SIZE ?

I guess not.

Usually, < PAGE_SIZE means NULL pointer dereference (via the member of a struct)

Christophe

---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus

```