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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9B44BC433EF for ; Sat, 11 Dec 2021 17:54:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Cj2pNhGFNBcxBXtDQDLNCIGlHjMyo0cKWAYZxk/k8d0=; b=2JzzplGJf0cCqv DPoCDldJlOhK1rX8waO3uAhZjzBZxON0hBMwhfz4ga8I16FgWKcxpoNVS9IzU3TFdM+qQHcoiiWry HXO6ZDQSfCriP+/UaU41guBZ1uZclMUdB9VuVUJ19z+vxkaLlBUrPltvYiwIHQltl3K5sBTnndkkT GsPaFhGExz25AVnoEchRqcPpY9MbjiOXfs9wDW8/3GS9rUiayRvGzf8+FiDSVhR2lFgi1qAKmqJqU rHfZVMItI+e8nPasCjNkPlQxHciFq24ItGGjEOWeHGLb0hQrCgz0KUV1qvfk5V5EA+KWt+OdLAvfb vRgBYNaGD+DCkIHV0KcQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mw6ZI-005KVT-Dt; Sat, 11 Dec 2021 17:53:56 +0000 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.85.151]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mw6ZC-005KU0-UY for linux-riscv@lists.infradead.org; Sat, 11 Dec 2021 17:53:52 +0000 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-14-gpculCQTMuGutzfqbGQ0WA-1; Sat, 11 Dec 2021 17:53:47 +0000 X-MC-Unique: gpculCQTMuGutzfqbGQ0WA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Sat, 11 Dec 2021 17:53:46 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.026; Sat, 11 Dec 2021 17:53:46 +0000 From: David Laight To: 'Tiezhu Yang' , Dave Young , Baoquan He , Vivek Goyal , Andrew Morton CC: "linux-arm-kernel@lists.infradead.org" , "linux-ia64@vger.kernel.org" , "linux-mips@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-riscv@lists.infradead.org" , "linux-sh@vger.kernel.org" , "x86@kernel.org" , "linux-fsdevel@vger.kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Xuefeng Li Subject: RE: [PATCH v2 0/2] kdump: simplify code Thread-Topic: [PATCH v2 0/2] kdump: simplify code Thread-Index: AQHX7j/jzYqw5kMpA0qY43nH0kUm2Kwtku5w Date: Sat, 11 Dec 2021 17:53:46 +0000 Message-ID: <0c5cb37139af4f3e85cc2c5115d7d006@AcuMS.aculab.com> References: <1639193588-7027-1-git-send-email-yangtiezhu@loongson.cn> In-Reply-To: <1639193588-7027-1-git-send-email-yangtiezhu@loongson.cn> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211211_095351_326983_8D8F4010 X-CRM114-Status: UNSURE ( 8.56 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Tiezhu Yang > Sent: 11 December 2021 03:33 > > v2: > -- add copy_to_user_or_kernel() in lib/usercopy.c > -- define userbuf as bool type Instead of having a flag to indicate whether the buffer is user or kernel, would it be better to have two separate buffer pointers. One for a user space buffer, the other for a kernel space buffer. Exactly one of the buffers should always be NULL. That way the flag is never incorrectly set. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv