From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1735C432C0 for ; Thu, 28 Nov 2019 08:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC7E32176D for ; Thu, 28 Nov 2019 08:18:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727126AbfK1ISi (ORCPT ); Thu, 28 Nov 2019 03:18:38 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:50546 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726882AbfK1ISi (ORCPT ); Thu, 28 Nov 2019 03:18:38 -0500 Received: from tun252.jain.kot-begemot.co.uk ([192.168.18.6] helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iaF0S-00069W-IN; Thu, 28 Nov 2019 08:18:32 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.92) (envelope-from ) id 1iaF0Q-0004D4-DI; Thu, 28 Nov 2019 08:18:32 +0000 Subject: Re: [PATCH -next] um: vector: use GFP_ATOMIC under spin lock To: Dan Carpenter , Wei Yongjun Cc: Song Liu , Daniel Borkmann , kernel-janitors@vger.kernel.org, Richard Weinberger , Jeff Dike , linux-um@lists.infradead.org, Alexei Starovoitov , netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau References: <20191128020147.191893-1-weiyongjun1@huawei.com> <20191128080641.GD1781@kadam> From: Anton Ivanov Message-ID: <5892ee7c-ff24-fb3c-6911-44e0b1d5895f@cambridgegreys.com> Date: Thu, 28 Nov 2019 08:18:30 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191128080641.GD1781@kadam> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Clacks-Overhead: GNU Terry Pratchett Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 28/11/2019 08:06, Dan Carpenter wrote: > On Thu, Nov 28, 2019 at 02:01:47AM +0000, Wei Yongjun wrote: >> A spin lock is taken here so we should use GFP_ATOMIC. >> >> Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers") >> Signed-off-by: Wei Yongjun >> --- >> arch/um/drivers/vector_kern.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c >> index 92617e16829e..6ff0065a271d 100644 >> --- a/arch/um/drivers/vector_kern.c >> +++ b/arch/um/drivers/vector_kern.c >> @@ -1402,7 +1402,7 @@ static int vector_net_load_bpf_flash(struct net_device *dev, >> kfree(vp->bpf->filter); >> vp->bpf->filter = NULL; >> } else { >> - vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_KERNEL); >> + vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_ATOMIC); >> if (vp->bpf == NULL) { >> netdev_err(dev, "failed to allocate memory for firmware\n"); >> goto flash_fail; >> @@ -1414,7 +1414,7 @@ static int vector_net_load_bpf_flash(struct net_device *dev, >> if (request_firmware(&fw, efl->data, &vdevice->pdev.dev)) > ^^^^^^^^^^^^^^^^ > > Is it really possible to call request_firmware() while holding a > spin_lock? I was so sure that read from the disk. Works, I tested the patch quite a few times. > > regards, > dan carpenter > >> goto flash_fail; >> >> - vp->bpf->filter = kmemdup(fw->data, fw->size, GFP_KERNEL); >> + vp->bpf->filter = kmemdup(fw->data, fw->size, GFP_ATOMIC); >> if (!vp->bpf->filter) >> goto free_buffer; >> >> > > _______________________________________________ > linux-um mailing list > linux-um@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-um > -- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/