Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755431AbaJNS6f (ORCPT ); Tue, 14 Oct 2014 14:58:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50042 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753601AbaJNS6e (ORCPT ); Tue, 14 Oct 2014 14:58:34 -0400 Date: Tue, 14 Oct 2014 15:58:29 -0300 From: Arnaldo Carvalho de Melo To: Stephane Eranian Cc: Namhyung Kim , LKML , Jiri Olsa , Peter Zijlstra , Ingo Molnar , David Ahern , Arnaldo Carvalho de Melo Subject: Re: [PATCH v2] perf tools: fix off-by-one error in maps Message-ID: <20141014185829.GA3839@redhat.com> References: <20141006083532.GA4850@quad> <8761fwh1nc.fsf@sejong.aot.lge.com> <20141007140050.GB2256@redhat.com> <20141007151035.GC2256@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Oct 07, 2014 at 05:17:12PM +0200, Stephane Eranian escreveu: > On Tue, Oct 7, 2014 at 5:10 PM, Arnaldo Carvalho de Melo > wrote: > > Em Tue, Oct 07, 2014 at 04:17:41PM +0200, Stephane Eranian escreveu: > >> On Tue, Oct 7, 2014 at 4:00 PM, Arnaldo Carvalho de Melo > >> >> +++ 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; > >> > I keep thinking that this change is making things unclear. > >> > I.e. the _start_ of a map (map->start) is _in_ the map, and the _end_ > >> > of a map (map->end) is _in_ the map as well. > >> > if (addr > m->end) > >> > is shorter than: > >> > if (addr >= m->end) > >> > "start" and "end" should have the same rule applied, i.e. if one is in, > >> > the other is in as well. > >> It is okay but then we need to be consistent all across. This is not > >> the case today. > >> I mentioned the cases I ran into. > > Ok, and provided a patch doing the way I thought was confusing, now its > > my turn to use that info and come up with a patch, ok, will do that. > You got it! ;-> struct vm_area_struct { /* The first cache line has the info for VMA tree walking. */ unsigned long vm_start; /* Our start address within vm_mm. */ unsigned long vm_end; /* The first byte after our end address within vm_mm. */ So these guys have been doing this far longer than me, I guess I'll bow to this convention. But by renaming map->end to map->end_ and looking at all the usage of it, there are some inconsistencies... Like symbol->{start,end} is of the [start,end] case, and to be consistent with above needs to also move to [start,end[, will cook a patch and send for review. - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/