Re: [PATCH 05/15 V3] perf, c2c: Rework setup code to prepare for features

[Don Zickus <dzickus@redhat.com>]

On Sat, Mar 29, 2014 at 06:10:18PM +0100, Jiri Olsa wrote:
> On Mon, Mar 24, 2014 at 03:36:56PM -0400, Don Zickus wrote:
> 
> SNIP
> 
> >  
> >  static int perf_c2c__process_load_store(struct perf_c2c *c2c,
> > +					struct addr_location *al,
> >  					struct perf_sample *sample,
> > -					struct addr_location *al)
> > +					struct perf_evsel *evsel)
> >  {
> > -	if (c2c->raw_records)
> > -		perf_sample__fprintf(sample, ' ', "raw input", al, stdout);
> > +	struct mem_info *mi;
> > +
> > +	mi = sample__resolve_mem(sample, al);
> > +	if (!mi)
> > +		return -ENOMEM;
> 
> perhaps not directly related to this patchset, but I needed
> attached patch to get resolved data in .bss (static), which
> for some reason happened to be located in executable segment
> 
> I wonder why we need this VARIABLE/FUNCTION separation at all,
> I think Arnaldo told me some archs could have same addresses
> for data and functions.. will check ;-)

Well that hack is a lot prettier than the one I came up with a couple of
weeks ago. :-)  Though I was more strict and only went down this path if
the protection bit had PROT_READ set.

Note to Arnaldo, I think this is only needed in //anon regions or the
[stack] (basically some private memory area that had PROT_READ and
PROT_EXEC set).  I noticed it with the java programs I was running.

Cheers,
Don
> 
> jirka
> 
> ---
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index d9d86c6..be6d7cf 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -1220,6 +1220,10 @@ static void ip__resolve_data(struct machine *machine, struct thread *thread,
>  
>  	thread__find_addr_location(thread, machine, m, MAP__VARIABLE, addr,
>  				   &al);
> +	if (!al.map)
> +		thread__find_addr_location(thread, machine, m, MAP__FUNCTION, addr,
> +					   &al);
> +
>  	ams->addr = addr;
>  	ams->al_addr = al.addr;
>  	ams->sym = al.sym;