From mboxrd@z Thu Jan 1 00:00:00 1970 From: f.fainelli@gmail.com (Florian Fainelli) Date: Thu, 25 Oct 2018 11:50:43 -0700 Subject: [PATCH] ARM: mm: Facilitate debugging CONFIG_KUSER_HELPERS disabled In-Reply-To: <87tvl9nas6.fsf@xmission.com> References: <20181025180957.7900-1-f.fainelli@gmail.com> <87tvl9nas6.fsf@xmission.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/25/18 11:25 AM, Eric W. Biederman wrote: > Florian Fainelli 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. -- Florian