Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752356Ab0H1HlO (ORCPT ); Sat, 28 Aug 2010 03:41:14 -0400 Received: from mtagate6.uk.ibm.com ([194.196.100.166]:39407 "EHLO mtagate6.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752026Ab0H1HlN (ORCPT ); Sat, 28 Aug 2010 03:41:13 -0400 Date: Sat, 28 Aug 2010 09:43:04 +0200 From: Heiko Carstens To: Stephen Boyd Cc: Arnd Bergmann , Martin Schwidefsky , Russell King , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] ARM: uaccess: Implement strict user copy checks Message-ID: <20100828074304.GA2183@osiris.boeblingen.de.ibm.com> References: <4C61EE55.5030506@codeaurora.org> <201008251414.16411.arnd@arndb.de> <20100825125451.GH2153@osiris.boeblingen.de.ibm.com> <201008251555.53653.arnd@arndb.de> <20100825144040.GI2153@osiris.boeblingen.de.ibm.com> <4C7867D4.10404@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C7867D4.10404@codeaurora.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7301 Lines: 97 On Fri, Aug 27, 2010 at 06:35:16PM -0700, Stephen Boyd wrote: > On 08/25/2010 07:40 AM, Heiko Carstens wrote: > > On Wed, Aug 25, 2010 at 03:55:53PM +0200, Arnd Bergmann wrote: > >> > >> If you don't want to see the warnings, then just remove the strict checks. > >> We already concluded that there is little value in them on s390 since it only > >> shows false postives. > >> > >> Maybe the easiest way would be to rename the option on s390 and move all > >> the other ones into a common place. > > > > Yes, feel free to do that. > > Can you put up the false positives somewhere? I don't have easy access > to an s390 toolchain to test build with and I'm interested to see how > bad the false positives are. > > I'm slightly concerned that we'll just have this problem again when > another arch comes along with false positives. But ignoring that issue > is probably fine. I'll respin with a patch to move s390 to something > like DEBUG_WARN_USER_COPY_CHECKS. Sure: In function 'copy_from_user', inlined from 'write_enabled_file_bool' at kernel/kprobes.c:1973: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'perf_copy_attr' at kernel/perf_event.c:4988, inlined from 'SYSC_perf_event_open' at kernel/perf_event.c:5092, inlined from 'SyS_perf_event_open' at kernel/perf_event.c:5077: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from '__tun_chr_ioctl' at drivers/net/tun.c:1200: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:880: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1143: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1250: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1272: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1296: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1319: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1342: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1363: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1384: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1405: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1432: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_if_write' at net/core/pktgen.c:1468: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_thread_write' at net/core/pktgen.c:1792: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'pktgen_thread_write' at net/core/pktgen.c:1823: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'write_file_bool' at fs/debugfs/file.c:434: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'sg_proc_write_dressz' at drivers/scsi/sg.c:2396: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'sg_proc_write_adio' at drivers/scsi/sg.c:2373: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'packet_getsockopt' at net/packet/af_packet.c:2123: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'compat_sys_socketcall' at net/compat.c:783: /linux-2.6/arch/s390/include/asm/uaccess.h:297: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably 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