Re: [PATCH 0/2] powerpc: kretprobe updates

[Masami Hiramatsu <mhiramat@kernel.org>]

On Fri, 17 Feb 2017 17:42:54 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Em Fri, Feb 17, 2017 at 07:44:33PM +0900, Masami Hiramatsu escreveu:
> > On Thu, 16 Feb 2017 13:47:37 +0530
> > "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> > 
> > > I am posting the powerpc bits in the same thread so as to keep these
> > > changes together. I am not sure how this should be taken upstream as
> > > there are atleast three different trees involved: one for the core
> > > kprobes infrastructure, one for powerpc and one for perf.
> 
> > Hmm, could you make these (and other related) patches and
> > other series in one series? Or wait for the other series
> > are merged correctly.
> 
> Well, patches like these should be done in a way that the tooling parts
> can deal with kernels with or without the kernel changes, so that older
> tools work with new kernels and new tools work with older kernels.
> 
> "work" as in the previous behaviour is kept when a new tool deals with
> an older kernel and an older tool would warn the user that what it needs
> is not present in that kernel.
> 
> Is this the case? I just looked briefly at the patch commit logs.

Thanks Arnaldo,

Naveen, I think this one and your previous series are incompatible
with older kernel. So those should be merged in one series and
at least (1) update ftrace's README special file to show explicitly
which can accept text+offset style for kretprobes, and (2) update
perf probe side to ensure that (and fallback to previous logic if not).

Thank you,

> 
> If it is, then I can pick the tool ones, and the others can be submitted
> to the relevant trees, at some point all will be in, kernels eventually
> gets updated everywhere, ditto for the tooling, all gets well.
> 
> Regards,
> 
> - Arnaldo
> 
> 
>  
> > Thank you,
> > 
> > > 
> > > Thanks,
> > > Naveen
> > > 
> > > Naveen N. Rao (2):
> > >   powerpc: kretprobes: override default function entry offset
> > >   perf: powerpc: choose LEP with kretprobes
> > > 
> > >  arch/powerpc/kernel/kprobes.c               | 9 +++++++++
> > >  tools/perf/arch/powerpc/util/sym-handling.c | 5 +----
> > >  2 files changed, 10 insertions(+), 4 deletions(-)
> > > 
> > > -- 
> > > 2.11.0
> > > 
> > 
> > 
> > -- 
> > Masami Hiramatsu <mhiramat@kernel.org>


-- 
Masami Hiramatsu <mhiramat@kernel.org>