Re: [PATCH 4/4] arm64: implement KPROBES_ON_FTRACE
From: Jisheng Zhang
Date: Mon Aug 19 2019 - 22:16:33 EST
On Mon, 19 Aug 2019 22:22:12 +0530 "Naveen N. Rao" wrote:
> Jisheng Zhang wrote:
> > This patch implements KPROBES_ON_FTRACE for arm64.
> > ~ # mount -t debugfs debugfs /sys/kernel/debug/
> > ~ # cd /sys/kernel/debug/
> > /sys/kernel/debug # echo 'p _do_fork' > tracing/kprobe_events
> > before the patch:
> > /sys/kernel/debug # cat kprobes/list
> > ffffff801009ff7c k _do_fork+0x4 [DISABLED]
> This looks wrong -- we should not be allowing kprobe to be registered on
Yes. I made a mistake when dumping this log. The kernel isn't as clean
as "before the patch".
> ftrace address without KPROBES_ON_FTRACE. Is _do_fork+0x4 the location
> of ftrace entry on arm64?
Indeed, w/o KPROBES_ON_FTRACE, it should be _do_fork+0x0