Re: [PATCH] ARM: mm: Facilitate debugging CONFIG_KUSER_HELPERS disabled

From: Florian Fainelli
Date: Thu Oct 25 2018 - 14:50:51 EST

On 10/25/18 11:25 AM, Eric W. Biederman wrote:
> Florian Fainelli <f.fainelli@xxxxxxxxx> writes:
>> Some software such as perf makes unconditional use of the special
>> [vectors] page which is only provided when CONFIG_KUSER_HELPERS is
>> enabled in the kernel.
>> Facilitate the debugging of such situations by printing a debug message
>> to the kernel log showing the task name and the faulting address.
> Can't someone trigger this segv deliberately and spam the kerne log?
> Doesn't this need something like printk_ratelimit or something to ensure
> this message only gets printed once?

Yes, good point, thanks.