From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751287AbbJWM7e (ORCPT ); Fri, 23 Oct 2015 08:59:34 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:63726 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750970AbbJWM7c (ORCPT ); Fri, 23 Oct 2015 08:59:32 -0400 X-IronPort-AV: E=Sophos;i="5.20,186,1444694400"; d="scan'208";a="312538546" From: Julien Grall To: , CC: Julien Grall , David Vrabel , Subject: [PATCH] mm: hotplug: Don't release twice the resource on error Date: Fri, 23 Oct 2015 13:57:33 +0100 Message-ID: <1445605053-23274-1-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Content-Type: text/plain X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function add_memory_resource take in parameter a resource allocated by the caller. On error, both add_memory_resource and the caller will release the resource via release_memory_source. This will result to Linux crashing when the caller is trying to release the resource: CPU: 1 PID: 45 Comm: xenwatch Not tainted 4.3.0-rc6-00043-g5e1d6ca-dirty #170 Hardware name: XENVM-4.7 (DT) task: ffffffc1fb2421c0 ti: ffffffc1fb270000 task.ti: ffffffc1fb270000 PC is at __release_resource+0x28/0x8c LR is at __release_resource+0x24/0x8c [...] Call trace: [] __release_resource+0x28/0x8c [] release_resource+0x24/0x44 [] reserve_additional_memory+0x114/0x128 [] alloc_xenballooned_pages+0x98/0x16c [] blkfront_gather_backend_features+0x14c/0xd68 [] blkback_changed+0x678/0x150c [] xenbus_otherend_changed+0x9c/0xa4 [] backend_changed+0xc/0x18 [] xenwatch_thread+0xa0/0x13c [] kthread+0xdc/0xf4 As the caller is allocating the resource, let him handle the release. This has been introduced by commit b75351f "mm: memory hotplug with an existing resource". Signed-off-by: Julien Grall --- Cc: David Vrabel Cc: linux-mm@kvack.org The patch who introduced this issue is in xentip/for-linus-4.4. So this patch is a good candidate for Linus 4.4. --- mm/memory_hotplug.c | 1 - 1 file changed, 1 deletion(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 5f394e7..0780d11 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1298,7 +1298,6 @@ error: /* rollback pgdat allocation and others */ if (new_pgdat) rollback_node_hotadd(nid, pgdat); - release_memory_resource(res); memblock_remove(start, size); out: -- 2.1.4