Messages in this thread |  | | Date | Sun, 11 Dec 2022 12:30:28 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v2 1/3] arm64: Prohibit instrumentation on arch_stack_walk() |
| |
On Fri, 9 Dec 2022 11:16:34 +0000 Mark Rutland <mark.rutland@arm.com> wrote:
> On Tue, Dec 06, 2022 at 09:41:37AM +0900, Masami Hiramatsu wrote: > > On Fri, 2 Dec 2022 13:17:30 +0000 > > Mark Rutland <mark.rutland@arm.com> wrote: > > > I had a go at testing this patch, and it fixes the crash with the reproducer > > > above, but there are plenty of other instances in stacktrace.c that lead to the > > > same sort of crash, e.g. > > > > > > # echo p stackinfo_get_task >> ${TRACEFS}/kprobe_events > > > # echo 1 > ${TRACEFS}/events/kprobes/enable > > > > Oops, thanks for pointing! Hmm, I thought stackinfo_get_task() is an > > inlined function usually. Maybe we should make it nokprobe_inline. > > But this is just one case. I need to scan all symbols to trace... > > FWIW, due to other instrumentation issues I've started doing a larger noinstr > cleanup on arm64 which should address this, as fixing this properly involves > also modifying a bunch of underlying helpers (e.g. preempt_count()). > > I can Cc you when sending that out, if you'd like? That'll probably be in the > new year.
Thanks Mark, yes, I'm interested in that work. Until that, I'll finish making a script for testing kprobes widely on kernel symbols.
Thank you,
> > Thanks, > Mark.
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
|  |