From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751236AbcEIRGk (ORCPT ); Mon, 9 May 2016 13:06:40 -0400 Received: from mail.kernel.org ([198.145.29.136]:47092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbcEIRGj (ORCPT ); Mon, 9 May 2016 13:06:39 -0400 Date: Mon, 9 May 2016 14:06:31 -0300 From: Arnaldo Carvalho de Melo To: Chris Phlipot Cc: adrian.hunter@intel.com, peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] perf tools: fix handling of zero-length symbols. Message-ID: <20160509170631.GC5101@kernel.org> References: <1462612620-25008-1-git-send-email-cphlipot0@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1462612620-25008-1-git-send-email-cphlipot0@gmail.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Sat, May 07, 2016 at 02:16:59AM -0700, Chris Phlipot escreveu: > This change introduces a fix to symbols__find, so that it is able to find > symbols of length zero (where start==end) > > The current code has the following problem: > -The current implementation of symbols__find is unable to find any symbols > of length zero. > -The db-export framework explicitly creates zero length symbols at > locations where no symbol currently exists. > > The combination of the two above behaviors results in behavior similar to > the example below. Ok, but you made the unlikely case be the first test, how about this one liner instead? diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 415c4f6d98fd..7a0917569fb3 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -301,7 +301,7 @@ static struct symbol *symbols__find(struct rb_root *symbols, u64 ip) if (ip < s->start) n = n->rb_left; - else if (ip >= s->end) + else if (ip > s->end || (ip == s->end && ip != s->start) n = n->rb_right; else return s; > +++ b/tools/perf/util/symbol.c > @@ -299,7 +299,9 @@ static struct symbol *symbols__find(struct rb_root *symbols, u64 ip) > while (n) { > struct symbol *s = rb_entry(n, struct symbol, rb_node); > > - if (ip < s->start) > + if (ip == s->start && s->start == s->end) > + return s; > + else if (ip < s->start) > n = n->rb_left; > else if (ip >= s->end) > n = n->rb_right; > -- > 2.7.4