From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Laight Subject: RE: [PATCH v2 05/18] x86: remove __range_not_ok() Date: Fri, 18 Feb 2022 15:45:56 +0000 Message-ID: <905678e9e05d40b9a4e13e7b1a34cb68@AcuMS.aculab.com> References: <20220216131332.1489939-1-arnd@kernel.org> <20220216131332.1489939-6-arnd@kernel.org> <20220218062851.GC22576@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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=9HjOUxkJDZcKY2lpfenRwzN0l0eUl60EzGlOOrevbww=; b=mvRy11ASXQtD2e 0jjAq4uWUqcmIQ5iD0lw12xNuymiFh4OP+++G3T6RqFnmn4es90gHj7nW5oBrY/vpNnswIL9X38Zw 4gVHLN5vpBNKr9p0TxP/8I33QA+bvSbVPStw71tAK9iM3B5Vj5ELGLjLa1LjckGFPBf+Euru97V2c HODM8CaZGij1Px7LfZGw7URViQwUd1mdaWSmqyRe0j6RwH1sPbyDKCdN0JFsRjTkLBUzsgTXGO4x0 MnckAhVXve3gUgal0IIc0bhrnJzo9/KRsn4Oj/jL/q2Fc9/rxsLHUzIzYAySRx9cToM1owiMM16Ck 0S0RZIMNcj8DQxO1YdWQ==; In-Reply-To: <20220218062851.GC22576@lst.de> Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org To: 'Christoph Hellwig' , Arnd Bergmann Cc: Linus Torvalds , "linux-arch@vger.kernel.org" , "linux-mm@kvack.org" , "linux-api@vger.kernel.org" , "arnd@arndb.de" , "linux-kernel@vger.kernel.org" , "viro@zeniv.linux.org.uk" , "linux@armlinux.org.uk" , "will@kernel.org" , "guoren@kernel.org" , "bcain@codeaurora.org" , "geert@linux-m68k.org" , "monstr@monstr.eu" , "tsbogend@alpha.franken.de" , "nickhu@andestech.com" , "green.hu@gmail.com" , "dinguyen@kernel.org" , "shorne@gmail.com" , "deller@gmx.de" , mp From: Christoph Hellwig > Sent: 18 February 2022 06:29 ... > > > diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c > > index 15b058eefc4e..ee117fcf46ed 100644 > > --- a/arch/x86/kernel/stacktrace.c > > +++ b/arch/x86/kernel/stacktrace.c > > @@ -90,7 +90,7 @@ copy_stack_frame(const struct stack_frame_user __user *fp, > > { > > int ret; > > > > - if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE)) > > + if (!__access_ok(fp, sizeof(*frame))) > > return 0; > > Just switch the __get_user calls below to get_user instead. Is this worth doing at all? How much userspace code is actually compiled with stack frames? Won't work well for a 32bit process on a 64bit kernel either. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)