Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759330Ab2BJNtU (ORCPT ); Fri, 10 Feb 2012 08:49:20 -0500 Received: from mail-lpp01m020-f174.google.com ([209.85.217.174]:40803 "EHLO mail-lpp01m020-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757937Ab2BJNtT convert rfc822-to-8bit (ORCPT ); Fri, 10 Feb 2012 08:49:19 -0500 MIME-Version: 1.0 In-Reply-To: <20120210134646.GB4998@infradead.org> References: <20120209103016.GA1999@quad> <20120209144844.GA4998@infradead.org> <20120210134646.GB4998@infradead.org> Date: Fri, 10 Feb 2012 14:49:17 +0100 Message-ID: Subject: Re: [PATCH] perf: add sanity check on addr in symbol__inc_addr_samples() From: Stephane Eranian To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@elte.hu Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2062 Lines: 54 On Fri, Feb 10, 2012 at 2:46 PM, Arnaldo Carvalho de Melo wrote: > Em Thu, Feb 09, 2012 at 03:53:14PM +0100, Stephane Eranian escreveu: >> On Thu, Feb 9, 2012 at 3:48 PM, Arnaldo Carvalho de Melo >> wrote: >> > Em Thu, Feb 09, 2012 at 11:30:16AM +0100, Stephane Eranian escreveu: >> >> >> >> Check the value of addr against the bounds of the symbol. >> >> This is needed given we compute an offset: >> >>       offset = addr - sym->start >> >> >> >> And we don't want the offset to become negative. >> > >> > I'll try and add a debug option to show the backtrace and values of >> > addr, sym, etc, so that we can fix the real problem. > >> > I.e. this function shouldn't be receiving any such invalid addresses, as >> > the symbol lookup was done, the symbol was found to be this one, then >> > why it would be out of bounds at this point?! > >> I tend to agree with you on this. But then I don't see why the first test >> was there. > > Its wrong as well, we should leave it there, together with the new test, > but as: > >        BUG_ON(addr >= sym->end || addr < sym->start) > Fine with me. It makes more sense. > - Arnaldo > >> > - Arnaldo >> > >> >> Signed-off-by: Stephane Eranian >> >> >> >> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c >> >> index 011ed26..8248d80 100644 >> >> --- a/tools/perf/util/annotate.c >> >> +++ b/tools/perf/util/annotate.c >> >> @@ -64,7 +64,7 @@ int symbol__inc_addr_samples(struct symbol *sym, struct map *map, >> >> >> >>       pr_debug3("%s: addr=%#" PRIx64 "\n", __func__, map->unmap_ip(map, addr)); >> >> >> >> -     if (addr >= sym->end) >> >> +     if (addr >= sym->end || addr < sym->start) >> >>               return 0; >> >> >> >>       offset = addr - sym->start; -- 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/