Re: [PATCH v2] perf tools: fix off-by-one error in maps

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Tue, Oct 07, 2014 at 02:47:19PM +0900, Namhyung Kim escreveu:
> Hi Stephane,
> 
> On Mon, 6 Oct 2014 10:35:32 +0200, Stephane Eranian wrote:
> > This patch fixes off-by-one errors in the management of maps.
> > A map is defined by start address and length as implemented by map__new():
> >
> > map__init(map, type, start, start + len, pgoff, dso);
> >
> > map->start = addr;
> > map->end = end;
> >
> > Consequently, the actual address range is ]start; end[
> > map->end is the first byte outside the range. This patch
> > fixes two bugs where upper bound checking was off-by-one.
> >
> > In V2, we fix map_groups__fixup_overlappings() some more
> > where map->start was off-by-one as reported by Jiri.
> 
>> It seems we also need to fix maps__find():


So I am getting this as an ack for Stephane's V2 patch and the patch
below as an extra patch, from you, acked by Stephane.

- Arnaldo
 
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index b7090596ac50..107a8c90785b 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -752,7 +752,7 @@ struct map *maps__find(struct rb_root *maps, u64 ip)
>                 m = rb_entry(parent, struct map, rb_node);
>                 if (ip < m->start)
>                         p = &(*p)->rb_left;
> -               else if (ip > m->end)
> +               else if (ip >= m->end)
>                         p = &(*p)->rb_right;
>                 else
>                         return m;
> 
> Thanks,
> Namhyung
> 
> 
> >
> > Signed-off-by: Stephane Eranian <eranian@google.com>
> > ---
> >  tools/perf/util/map.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> > index b709059..186418b 100644
> > --- a/tools/perf/util/map.c
> > +++ b/tools/perf/util/map.c
> > @@ -556,7 +556,7 @@ struct symbol *map_groups__find_symbol_by_name(struct map_groups *mg,
> >  
> >  int map_groups__find_ams(struct addr_map_symbol *ams, symbol_filter_t filter)
> >  {
> > -	if (ams->addr < ams->map->start || ams->addr > ams->map->end) {
> > +	if (ams->addr < ams->map->start || ams->addr >= ams->map->end) {
> >  		if (ams->map->groups == NULL)
> >  			return -1;
> >  		ams->map = map_groups__find(ams->map->groups, ams->map->type,
> > @@ -664,7 +664,7 @@ int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map,
> >  				goto move_map;
> >  			}
> >  
> > -			before->end = map->start - 1;
> > +			before->end = map->start;
> >  			map_groups__insert(mg, before);
> >  			if (verbose >= 2)
> >  				map__fprintf(before, fp);
> > @@ -678,7 +678,7 @@ int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map,
> >  				goto move_map;
> >  			}
> >  
> > -			after->start = map->end + 1;
> > +			after->start = map->end;
> >  			map_groups__insert(mg, after);
> >  			if (verbose >= 2)
> >  				map__fprintf(after, fp);