Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757233Ab1CIP5u (ORCPT ); Wed, 9 Mar 2011 10:57:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49916 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757010Ab1CIP5t (ORCPT ); Wed, 9 Mar 2011 10:57:49 -0500 Date: Wed, 9 Mar 2011 12:57:24 -0300 From: Arnaldo Carvalho de Melo To: Lin Ming Cc: Lin Ming , Han Pingtian , Peter Zijlstra , Franck Bui-Huu , Ingo Molnar , linux-kernel , linux-perf-users@vger.kernel.org Subject: Re: [PATCH] perf: Avoid resolving [kernel.kallsyms] to real path for buildid cache Message-ID: <20110309155724.GB14438@ghostprotocols.net> References: <1299165837-27817-1-git-send-email-ming.m.lin@intel.com> 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: 3439 Lines: 98 Em Wed, Mar 09, 2011 at 10:38:52PM +0800, Lin Ming escreveu: > Hi, Arnaldo > > Could you have a look at this patch? > > Thanks, > Lin Ming Seems ok, problem was introduced in: commit 68a7a771ad0e2959983729bf88cbc74a7014438f Author: Franck Bui-Huu Date: Fri Dec 10 22:06:26 2010 +0100 perf buildid-cache: Fix symbolic link handling This was broken since link(2) doesn't dereference symbolic links. Instead 'filename' becomes a symbolic link to the same file that 'name' refers to. This had the bad effect to create dangling symlinks in the case that even can't be removed with perf-buildid-cache(1). LKML-Reference: Signed-off-by: Franck Bui-Huu Signed-off-by: Arnaldo Carvalho de Melo [acme@emilia linux]$ git describe 68a7a771 v2.6.37-rc5-71-g68a7a77 So I'll add a CC: stable@kernel.org when pushing to perf/urgent. - Arnaldo > On Thu, Mar 3, 2011 at 11:23 PM, Lin Ming wrote: > > kallsyms has a virtual file name [kernel.kallsyms]. > > Currently, it can't be added to buildid cache successfully > > because the code(build_id_cache__add_s) tries to resolve > > [kernel.kallsyms]to a real absolute pathname and that fails. > > > > Fixes it by not resolving it and just use the name [kernel.kallsyms]. > > So dir ~/.debug/[kernel.kallsyms] is created. > > > > Original bug report at: > > https://lkml.org/lkml/2011/3/1/524 > > > > Tested-by: Han Pingtian > > Signed-off-by: Lin Ming > > --- > > ?tools/perf/util/header.c | ? 11 ++++++++--- > > ?1 files changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c > > index 72c124d..1f8883b 100644 > > --- a/tools/perf/util/header.c > > +++ b/tools/perf/util/header.c > > @@ -271,11 +271,15 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir, > > ? ? ? ? ? ? ? ? ? ? ? ? ?const char *name, bool is_kallsyms) > > ?{ > > ? ? ? ?const size_t size = PATH_MAX; > > - ? ? ? char *realname = realpath(name, NULL), > > - ? ? ? ? ? ?*filename = malloc(size), > > + ? ? ? char *realname, *filename = malloc(size), > > ? ? ? ? ? ? *linkname = malloc(size), *targetname; > > ? ? ? ?int len, err = -1; > > > > + ? ? ? if (is_kallsyms) > > + ? ? ? ? ? ? ? realname = (char *)name; > > + ? ? ? else > > + ? ? ? ? ? ? ? realname = realpath(name, NULL); > > + > > ? ? ? ?if (realname == NULL || filename == NULL || linkname == NULL) > > ? ? ? ? ? ? ? ?goto out_free; > > > > @@ -307,7 +311,8 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir, > > ? ? ? ?if (symlink(targetname, linkname) == 0) > > ? ? ? ? ? ? ? ?err = 0; > > ?out_free: > > - ? ? ? free(realname); > > + ? ? ? if (!is_kallsyms) > > + ? ? ? ? ? ? ? free(realname); > > ? ? ? ?free(filename); > > ? ? ? ?free(linkname); > > ? ? ? ?return err; > > -- > > 1.7.2.3 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at ?http://vger.kernel.org/majordomo-info.html > > -- 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/