From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967551AbeBNLrq (ORCPT ); Wed, 14 Feb 2018 06:47:46 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50934 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S967360AbeBNLrp (ORCPT ); Wed, 14 Feb 2018 06:47:45 -0500 Subject: Re: WARNING in kvmalloc_node To: Daniel Borkmann , Michal Hocko , Matthew Wilcox Cc: syzbot , akpm@linux-foundation.org, dhowells@redhat.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mingo@kernel.org, rppt@linux.vnet.ibm.com, syzkaller-bugs@googlegroups.com, vbabka@suse.cz, viro@zeniv.linux.org.uk, Alexei Starovoitov , netdev@vger.kernel.org, brouer@redhat.com, "Michael S. Tsirkin" References: <001a1144c4ca5dc9d6056520c7b7@google.com> <20180214025533.GA28811@bombadil.infradead.org> <20180214084308.GX3443@dhcp22.suse.cz> From: Jason Wang Message-ID: <24351362-a099-3317-2b96-8cdc6835eb1e@redhat.com> Date: Wed, 14 Feb 2018 19:47:30 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018年02月14日 17:28, Daniel Borkmann wrote: > [ +Jason, +Jesper ] > > On 02/14/2018 09:43 AM, Michal Hocko wrote: >> On Tue 13-02-18 18:55:33, Matthew Wilcox wrote: >>> On Tue, Feb 13, 2018 at 03:59:01PM -0800, syzbot wrote: >> [...] >>>> kvmalloc include/linux/mm.h:541 [inline] >>>> kvmalloc_array include/linux/mm.h:557 [inline] >>>> __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:474 [inline] >>>> ptr_ring_init include/linux/ptr_ring.h:492 [inline] >>>> __cpu_map_entry_alloc kernel/bpf/cpumap.c:359 [inline] >>>> cpu_map_update_elem+0x3c3/0x8e0 kernel/bpf/cpumap.c:490 >>>> map_update_elem kernel/bpf/syscall.c:698 [inline] >>> Blame the BPF people, not the MM people ;-) > Heh, not really. ;-) > >> Yes. kvmalloc (the vmalloc part) doesn't support GFP_ATOMIC semantic. > Agree, that doesn't work. > > Bug was added in commit 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails"). > > Jason, please take a look at fixing this, thanks! It looks to me the only solution is to revert that commit. Will post a patch. Thanks