Re: [PATCH] perf report: Fix segfault with '-F phys_daddr'

[Ravi Bangoria]

On 11/12/19 7:48 PM, Arnaldo Carvalho de Melo wrote:
> Em Tue, Nov 12, 2019 at 07:28:06PM +0530, Ravi Bangoria escreveu:
> > On 11/12/19 4:34 PM, Arnaldo Carvalho de Melo wrote:
> > > Em Tue, Nov 12, 2019 at 11:19:46AM +0530, Ravi Bangoria escreveu:
> > > > If perf.data file is not recorded with mem-info, adding 'phys_daddr'
> > > > to output field in perf report results in segfault. Fix that.
> > > >
> > > > Before:
> > > >     $ ./perf record ls
> > > >     $ ./perf report -F +phys_daddr
> > > >     Segmentation fault (core dumped)
> > > >
> > > > After:
> > > >     $ ./perf report -F +phys_daddr
> > > >     Samples: 11  of event 'cycles:u', Event count (approx.): 1485821
> > > >     Overhead  Data Physical Address  Command  Shared Object  Symbol
> > > >       22.57%  [.] 0000000000000000   ls       libc-2.29.so   [.] __strcoll_l
> > > >       21.87%  [.] 0000000000000000   ls       ld-2.29.so     [.] _dl_relocate_object
> > > >       ...
> > >
> > > Shouldn't we instead just bail out and state that this isn't possible
> > > and leave the user wondering why what was asked isn't presented?
> >
> > You mean popup with something like "phys_daddr is not available in perf.data"
> > and also don't show that column in perf report?
>
> Just bail out completely, something like:
>
>
>     $ ./perf report -F +phys_daddr
>     "phys_daddr" is not available in perf.data, use 'record -e some,thing' to have it.

Sure. Thanks for the suggestion. Will re-spin.

Ravi