Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759310Ab2BJNrA (ORCPT ); Fri, 10 Feb 2012 08:47:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30979 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758819Ab2BJNq7 (ORCPT ); Fri, 10 Feb 2012 08:46:59 -0500 Date: Fri, 10 Feb 2012 11:46:46 -0200 From: Arnaldo Carvalho de Melo To: Stephane Eranian Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@elte.hu Subject: Re: [PATCH] perf: add sanity check on addr in symbol__inc_addr_samples() Message-ID: <20120210134646.GB4998@infradead.org> References: <20120209103016.GA1999@quad> <20120209144844.GA4998@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 50 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) - 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/