Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

From: Masami Hiramatsu
Date: Thu May 25 2017 - 21:36:54 EST


On Thu, 25 May 2017 11:18:02 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Thu, 25 May 2017 19:34:43 +0900
> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
>
>
> > OK, I've ensured that following command hits same BUG.
> >
> > grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \
> > head -n 256 | while read i; do echo p $i+5 ; done >
> > tracing/kprobe_events
> >
> > echo 1 > tracing/events/kprobes/enable
> > echo 0 > tracing/events/kprobes/enable
> > echo > tracing/kprobe_events
> > sleep 5
>
> Hi Masami,
>
> Can you add a selftest that checks this too?

Yes, however, it should be included after my fix is
accepted, or it can cause a kernel panic...

Thanks,



--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>