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

[Naveen N. Rao]

On 2017/02/21 10:07PM, Masami Hiramatsu wrote:
> On Mon, 20 Feb 2017 15:20:24 +0530
> "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > On 2017/02/19 01:42PM, Masami Hiramatsu wrote:
> > > On Fri, 17 Feb 2017 17:42:54 -0300
> > > Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx> 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 
> > 
> > Sure - do you mean Documentation/trace/kprobetrace.txt? And, do you want 
> > me to include kernel version where this changed?
> 
> No, I meant /sys/kernel/debug/tracing/README. For some reasons, perf
> probe already parse it in util/probe-file.c. 
> Please see commit 180b20616ce57e93eb692170c793be94c456b1e2 and 
> 864256255597aad86abcecbe6c53da8852ded15b

Got it.

Thanks,
Naveen