Received: by 2002:a05:6902:102b:0:0:0:0 with SMTP id x11csp228364ybt; Tue, 23 Jun 2020 20:25:56 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzkzKANXaGCmAICiaTUJRQR+8cPXjh5QAA6u6+/6KKYx1rXtDOW9oljHByKVNuhrd8kFPbo X-Received: by 2002:a50:fd12:: with SMTP id i18mr10693639eds.371.1592969155856; Tue, 23 Jun 2020 20:25:55 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1592969155; cv=none; d=google.com; s=arc-20160816; b=I+wqB94+GzuDxzHqzjli2tu24hBJjJPIKfrlc001TT/ztcNh6jTdk9B2uocoz59kWm tO2UDwiyYizIHHc135HqJ6f0P2ChOUrF4f2+BGrxyeUlNYybMCxk0VggqqISnneYVFNb JKhBoFy4sLtQcm9sunq0kphM8fZhS7Xy4wUA2z0CaV6ZCeZPORWscrLadiDQt0+yo0Vy vMbAqmIZIfdnVn3kU1Wdlj5f+fTlt7/QcdcIHV+zJC3l9miesDNQa/SU+iidGKM0zdBh fJUu+dc3hsn4DpL//8Eti+FMuDfKXbj3K5MAhrolx240CYzP+OrfGsIkzORDsqL9xGLD AtLQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:from:subject:cc:to:message-id:date; bh=vnnAjOyuFzrONqW7XhSXOrzSdbbWJ+92CwrhQ3DhjRQ=; b=n0LQf1tUJBVg8ZhApsN+ACBgw5/tGuOaiYZbjy8vYdrsBZdJ0U9b/xioTS6Np2+h24 bM+hWa5f+j02GF96FMfTaf0nHNvk/7gFlez2oLBPdTjU3WMOyqkDd2ifPAVG6ZQUCQyq cOxhEguCAdJcZ/89TI6COVgQgh+m/JUCpniO+F5FE4jqfe9FRLMpEgrD00q+sTnYJ+E1 dHUaZW9xk9VIOWQU/TbsKEJ+/iuiBGw7kYdcM1AOXuOggeFkNJNONTItP0b/7rlx7E14 bzz/2DYE6cdxe3vvgJ11nZ8Zeg8BriFTIosu3xX+4D1V1uBIvYWJombAgCezhFBwAp8v mNug== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id i20si2411635edy.277.2020.06.23.20.25.33; Tue, 23 Jun 2020 20:25:55 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388579AbgFXDX0 (ORCPT + 99 others); Tue, 23 Jun 2020 23:23:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387985AbgFXDX0 (ORCPT ); Tue, 23 Jun 2020 23:23:26 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C44BC061573; Tue, 23 Jun 2020 20:23:26 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 5033A1298361E; Tue, 23 Jun 2020 20:23:25 -0700 (PDT) Date: Tue, 23 Jun 2020 20:23:24 -0700 (PDT) Message-Id: <20200623.202324.442008830004872069.davem@davemloft.net> To: likaige@loongson.cn Cc: benve@cisco.com, _govind@gmx.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, lixuefeng@loongson.cn, yangtiezhu@loongson.cn Subject: Re: [PATCH RESEND] net/cisco: Fix a sleep-in-atomic-context bug in enic_init_affinity_hint() From: David Miller In-Reply-To: <7533075e-0e8e-2fde-c8fa-72e2ea222176@loongson.cn> References: <20200623.143311.995885759487352025.davem@davemloft.net> <20200623.152626.2206118203643133195.davem@davemloft.net> <7533075e-0e8e-2fde-c8fa-72e2ea222176@loongson.cn> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 23 Jun 2020 20:23:25 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kaige Li Date: Wed, 24 Jun 2020 09:56:47 +0800 > > On 06/24/2020 06:26 AM, David Miller wrote: >> From: David Miller >> Date: Tue, 23 Jun 2020 14:33:11 -0700 (PDT) >> >>> Calling a NIC driver open function from a context holding a spinlock >>> is very much the real problem, so many operations have to sleep and >>> in face that ->ndo_open() method is defined as being allowed to sleep >>> and that's why the core networking never invokes it with spinlocks >> ^^^^ >> >> I mean "without" of course. :-) >> >>> held. > > Did you mean that open function should be out of spinlock? If so, I > will > send V2 patch. Yes, but only if that is safe. You have to analyze the locking done by this driver and fix it properly. I anticipate it is not just a matter of changing where the spinlock is held, you will have to rearchitect things a bit.