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Fri, 18 Feb 2022 15:46:04 +0000 (UTC) X-FDA: 79156326648.22.F5A9D18 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by imf15.hostedemail.com (Postfix) with ESMTP id B4177A0007 for ; Fri, 18 Feb 2022 15:46:03 +0000 (UTC) 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-70--4RjbVXtMcueaeoDqT_n6w-1; Fri, 18 Feb 2022 15:45:59 +0000 X-MC-Unique: -4RjbVXtMcueaeoDqT_n6w-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 15.0.1497.28; Fri, 18 Feb 2022 15:45:56 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.028; Fri, 18 Feb 2022 15:45:56 +0000 From: David Laight 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" , "mpe@ellerman.id.au" , "peterz@infradead.org" , "mingo@redhat.com" , "mark.rutland@arm.com" , "hca@linux.ibm.com" , "dalias@libc.org" , "davem@davemloft.net" , "richard@nod.at" , "x86@kernel.org" , "jcmvbkbc@gmail.com" , "ebiederm@xmission.com" , "akpm@linux-foundation.org" , "ardb@kernel.org" , "linux-alpha@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" , "linux-csky@vger.kernel.org" , "linux-hexagon@vger.kernel.org" , "linux-ia64@vger.kernel.org" , "linux-m68k@lists.linux-m68k.org" , "linux-mips@vger.kernel.org" , "openrisc@lists.librecores.org" , "linux-parisc@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "linux-sh@vger.kernel.org" , "sparclinux@vger.kernel.org" , "linux-um@lists.infradead.org" , "linux-xtensa@linux-xtensa.org" , Christoph Hellwig Subject: RE: [PATCH v2 05/18] x86: remove __range_not_ok() Thread-Topic: [PATCH v2 05/18] x86: remove __range_not_ok() Thread-Index: AQHYJJDV6CwChj5QoEqoVAdoFeMQC6yZc16A 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> In-Reply-To: <20220218062851.GC22576@lst.de> 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 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: ygsibx8cksxco1ggffk1zknm5bakqq7a X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=none; spf=pass (imf15.hostedemail.com: domain of david.laight@aculab.com designates 185.58.85.151 as permitted sender) smtp.mailfrom=david.laight@aculab.com; dmarc=pass (policy=none) header.from=aculab.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: B4177A0007 X-HE-Tag: 1645199163-782802 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000198, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Christoph Hellwig > Sent: 18 February 2022 06:29 ... >=20 > > 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, > > { > > =09int ret; > > > > -=09if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE)) > > +=09if (!__access_ok(fp, sizeof(*frame))) > > =09=09return 0; >=20 > 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. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)