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

- From: Sergey Senozhatsky \<hidden\>
- Date: 2019-05-10 05:07:16 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2019/05/5593769
- Thread: https://ratatoskr.run/linuxppc-dev/2019/05/5592853/t.md

```text
On (05/09/19 21:47), Linus Torvalds wrote:
>    [ Sorry about html and mobile crud, I'm not at the computer right now ]
>    How about we just undo the whole misguided probe_kernel_address() thing?

But the problem will remain - %pS/%pF on PPC (and some other arch-s)
do dereference_function_descriptor(), which calls probe_kernel_address().
So if probe_kernel_address() starts to dump_stack(), then we are heading
towards stack overflow. Unless I'm totally missing something.

	-ss
```