Re: in stable 4.4.131 kprobes seems to be broken

[Jack Wang <jack dot wang dot usish at gmail dot com>]

> 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.

Regards,
Jack