Re: [PATCHv2] perf bpf: Fix endianness problem when loading parameters in prologue

[Wangnan (F)]

On 2017/8/15 14:42, Thomas-Mich Richter wrote:
> On 08/14/2017 06:39 PM, Arnaldo Carvalho de Melo wrote:
> > Em Mon, Aug 14, 2017 at 01:46:44PM +0200, Thomas Richter escreveu:
> > > Perf BPF prologue generator unconditionally fetches 8 bytes for function
> > > parameters, which causes problem on big endian machine. Thomas gives a
> > > detail analysis for this problem:
> > >
> > >   http://lkml.kernel.org/r/968ebda5-abe4-8830-8d69-49f62529d151@xxxxxxxxxxxxxxxxxx
> > >
> > > This patch parses the type of each argument and converts data from
> > > memory to expected type.
> > >
> > > Now the test runs successfully on 4.13.0-rc5:
> > > [root@s8360046 perf]# ./perf test  bpf
> > > 38: BPF filter                                 :
> > > 38.1: Basic BPF filtering                      : Ok
> > > 38.2: BPF pinning                              : Ok
> > > 38.3: BPF prologue generation                  : Ok
> > > 38.4: BPF relocation checker                   : Ok
> > > [root@s8360046 perf]#
> > >
> > > Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> > > Acked-by: Wang Nan <wangnan0@xxxxxxxxxx>
> > > Tested-by: Wang Nan <wangnan0@xxxxxxxxxx>
> >
> > That is strange, who is the author of the patch? Also I think Tested-by
> > is enough, being an even stronger form of Acked-by?
> >
> > But then you also have Signed-off-by: Wang in there...
> >
> >  From Documentation/process/submitting-patches.rst:
> >
> > ---------
> >
> > 12) When to use Acked-by: and Cc:
> > ---------------------------------
> >
> > The Signed-off-by: tag indicates that the signer was involved in the
> > development of the patch, or that he/she was in the patch's delivery path.
> >
> > If a person was not directly involved in the preparation or handling of a
> > patch but wishes to signify and record their approval of it then they can
> > ask to have an Acked-by: line added to the patch's changelog.
> >
> > Acked-by: is often used by the maintainer of the affected code when that
> > maintainer neither contributed to nor forwarded the patch.
> >
> > ------------------
> >
> > If Wang wrote the original patch and you made it better working together
> > with him, probably having both of you in Signed-off-by lines should be
> > enough?
> >
> > - Arnaldo
> Ok, my fault then.
> Wang wrote to patch in the first place, I just fixed one line.
> Should I resend the patch and delete the Acked-by/Tested-by lines
> in the commit message?

Yes, please resend it.

> Thanks