From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754745AbcKNDdI (ORCPT ); Sun, 13 Nov 2016 22:33:08 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45270 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753368AbcKNCFE (ORCPT ); Sun, 13 Nov 2016 21:05:04 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mukesh Ojha" , "Vasant Hegde" , "Benjamin Herrenschmidt" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 230/346] powerpc/powernv : Drop reference added by kset_find_obj() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mukesh Ojha commit a9cbf0b2195b695cbeeeecaa4e2770948c212e9a upstream. In a situation, where Linux kernel gets notified about duplicate error log from OPAL, it is been observed that kernel fails to remove sysfs entries (/sys/firmware/opal/elog/0xXXXXXXXX) of such error logs. This is because, we currently search the error log/dump kobject in the kset list via 'kset_find_obj()' routine. Which eventually increment the reference count by one, once it founds the kobject. So, unless we decrement the reference count by one after it found the kobject, we would not be able to release the kobject properly later. This patch adds the 'kobject_put()' which was missing earlier. Signed-off-by: Mukesh Ojha Reviewed-by: Vasant Hegde Signed-off-by: Benjamin Herrenschmidt [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- arch/powerpc/platforms/powernv/opal-dump.c | 7 ++++++- arch/powerpc/platforms/powernv/opal-elog.c | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) --- a/arch/powerpc/platforms/powernv/opal-dump.c +++ b/arch/powerpc/platforms/powernv/opal-dump.c @@ -365,6 +365,7 @@ static int process_dump(void) uint32_t dump_id, dump_size, dump_type; struct dump_obj *dump; char name[22]; + struct kobject *kobj; rc = dump_read_info(&dump_id, &dump_size, &dump_type); if (rc != OPAL_SUCCESS) @@ -376,8 +377,12 @@ static int process_dump(void) * that gracefully and not create two conflicting * entries. */ - if (kset_find_obj(dump_kset, name)) + kobj = kset_find_obj(dump_kset, name); + if (kobj) { + /* Drop reference added by kset_find_obj() */ + kobject_put(kobj); return 0; + } dump = create_dump_obj(dump_id, dump_size, dump_type); if (!dump) --- a/arch/powerpc/platforms/powernv/opal-elog.c +++ b/arch/powerpc/platforms/powernv/opal-elog.c @@ -246,6 +246,7 @@ static void elog_work_fn(struct work_str uint64_t elog_type; int rc; char name[2+16+1]; + struct kobject *kobj; rc = opal_get_elog_size(&id, &size, &type); if (rc != OPAL_SUCCESS) { @@ -268,8 +269,12 @@ static void elog_work_fn(struct work_str * that gracefully and not create two conflicting * entries. */ - if (kset_find_obj(elog_kset, name)) + kobj = kset_find_obj(elog_kset, name); + if (kobj) { + /* Drop reference added by kset_find_obj() */ + kobject_put(kobj); return; + } create_elog_obj(log_id, elog_size, elog_type); }