Re: [RFC][PATCH] kprobes/x86: While list ftrace locations in kprobe blacklist areas

From: Steven Rostedt
Date: Thu Oct 10 2019 - 17:55:39 EST


On Thu, 10 Oct 2019 17:52:16 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> I noticed some of my old tests failing on kprobes, and realized that
> this was due to black listing irq_entry functions on x86 from being
> used by kprobes. IIRC, this was due to the cr2 being corrupted and
> such, and I believe other things were to cause. But black listing all
> irq_entry code is a big hammer to this.
>
> (See commit 0eae81dc9f026 "x86/kprobes: Prohibit probing on IRQ
> handlers directly" for more details)

BTW, I noticed this recently (again) when running my tests by hand. I
forgot that I have my automated tests revert the above commit before
compiling the kernel it is about to test (because it tests kprobes on
irq entry locations!). My tests never had issues with kprobes on irq
entry locations.

-- Steve