From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753634AbdJSNu3 (ORCPT ); Thu, 19 Oct 2017 09:50:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46108 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753600AbdJSNu0 (ORCPT ); Thu, 19 Oct 2017 09:50:26 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Grygorii Maistrenko , Pekka Enberg , David Rientjes , Christoph Lameter , Joonsoo Kim , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.9 26/51] slub: do not merge cache if slub_debug contains a never-merge flag Date: Thu, 19 Oct 2017 15:48:47 +0200 Message-Id: <20171019134842.953606228@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171019134841.383925150@linuxfoundation.org> References: <20171019134841.383925150@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Grygorii Maistrenko [ Upstream commit c6e28895a4372992961888ffaadc9efc643b5bfe ] In case CONFIG_SLUB_DEBUG_ON=n, find_mergeable() gets debug features from commandline but never checks if there are features from the SLAB_NEVER_MERGE set. As a result selected by slub_debug caches are always mergeable if they have been created without a custom constructor set or without one of the SLAB_* debug features on. This moves the SLAB_NEVER_MERGE check below the flags update from commandline to make sure it won't merge the slab cache if one of the debug features is on. Link: http://lkml.kernel.org/r/20170101124451.GA4740@lp-laptop-d Signed-off-by: Grygorii Maistrenko Reviewed-by: Pekka Enberg Acked-by: David Rientjes Acked-by: Christoph Lameter Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- mm/slab_common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -255,7 +255,7 @@ struct kmem_cache *find_mergeable(size_t { struct kmem_cache *s; - if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) + if (slab_nomerge) return NULL; if (ctor) @@ -266,6 +266,9 @@ struct kmem_cache *find_mergeable(size_t size = ALIGN(size, align); flags = kmem_cache_flags(size, flags, name, NULL); + if (flags & SLAB_NEVER_MERGE) + return NULL; + list_for_each_entry_reverse(s, &slab_caches, list) { if (slab_unmergeable(s)) continue;