On 2017/02/17 05:42PM, Arnaldo Carvalho de Melo wrote:

Em Fri, Feb 17, 2017 at 07:44:33PM +0900, Masami Hiramatsu escreveu:

quoted

On Thu, 16 Feb 2017 13:47:37 +0530
"Naveen N. Rao" [off-list ref] wrote:

quoted

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.

quoted

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, that makes sense.

All the kernel patches here can go in as they are about removing the 
restrictions around use of kretprobes with kprobe_event, except for the 
first patch which hardens use of kretprobes in general by validating 
addresses. None of that should cause issues with the existing tools.

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.

Older perf tools with newer kernels will be fine. However, with the 
current perf patches, newer perf will fail with older kernels. I will 
redo the perf patches to address this. So, please don't merge the perf 
bits in this series.


Regards,
Naveen