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

- From: David Laight \<hidden\>
- Date: 2019-05-14 08:28:30 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2019/05/5596130
- Thread: https://ratatoskr.run/linuxppc-dev/2019/05/5592853/t.md

```text
> And I like Steven's "(fault)" idea.
> How about this:
> 
> 	if ptr < PAGE_SIZE		-> "(null)"
> 	if IS_ERR_VALUE(ptr)		-> "(fault)"
> 
> 	-ss

Or:
	if (ptr < PAGE_SIZE)
		return ptr ? "(null+)" : "(null)";
	if IS_ERR_VALUE(ptr)
		return "(errno)"

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

```