Re: in stable 4.4.131 kprobes seems to be broken

[Greg Kroah-Hartman <gregkh at linuxfoundation dot org>]

On Tue, Jul 10, 2018 at 02:26:43PM +0200, Jack Wang wrote:
> > That commit seems to be part of some x86 kprobes restructuring, I
> > hesitated to try it. After your email tried to cherry-pick to 4.4.y
> > and it does not go in smoothly at all, quite a bit of conflicts.
> >
> > I may not phrase it correctly: My point was that in 4.4 there
> > are more places where synthesize_reljump function is called, which
> > latter got removed. And this function modifies kprobes page, so
> > lifting up read-only protection needs to be done in more places
> > compared to latter kernels. Whether it can be done correctly and
> > proper thing to do in do_debug/resume_execution function
> > exception processing context I cannot tell.
> >
> > Thanks,
> > Victor
> >
> > > thanks,
> > >
> > > greg k-h
> > >
> Hi Victor, Hi Greg,
> 
> Alexey Makhalov  (+cc) ported the fix to kernel 4.4 2 weeks ago.
> https://www.spinics.net/lists/stable/msg245223.html
> 
> It applies cleanly to 4.4.139.

Ah, nice, that's already queued up and will be in the next 4.4.y release
in a few days.

thanks,

greg k-h