From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751877AbdCCN4N (ORCPT ); Fri, 3 Mar 2017 08:56:13 -0500 Received: from mail-qk0-f169.google.com ([209.85.220.169]:33393 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbdCCN4J (ORCPT ); Fri, 3 Mar 2017 08:56:09 -0500 MIME-Version: 1.0 In-Reply-To: <7e7a62de-3b79-6044-72fa-4ade418953d1@virtuozzo.com> References: <20170302163834.2273519-1-arnd@arndb.de> <20170302163834.2273519-2-arnd@arndb.de> <7e7a62de-3b79-6044-72fa-4ade418953d1@virtuozzo.com> From: Alexander Potapenko Date: Fri, 3 Mar 2017 14:55:35 +0100 Message-ID: Subject: Re: [PATCH 01/26] compiler: introduce noinline_for_kasan annotation To: Andrey Ryabinin Cc: Arnd Bergmann , kasan-dev , Dmitry Vyukov , netdev@vger.kernel.org, LKML , linux-media@vger.kernel.org, linux-wireless@vger.kernel.org, kernel-build-reports@lists.linaro.org, "David S . Miller" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v23DuOOS021949 On Fri, Mar 3, 2017 at 2:50 PM, Andrey Ryabinin wrote: > > > On 03/02/2017 07:38 PM, Arnd Bergmann wrote: >> When CONFIG_KASAN is set, we can run into some code that uses incredible >> amounts of kernel stack: >> >> drivers/staging/dgnc/dgnc_neo.c:1056:1: error: the frame size of 11112 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] >> drivers/media/i2c/cx25840/cx25840-core.c:4960:1: error: the frame size of 94000 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] >> drivers/media/dvb-frontends/stv090x.c:3430:1: error: the frame size of 5312 bytes is larger than 3072 bytes [-Werror=frame-larger-than=] >> >> This happens when a sanitizer uses stack memory each time an inline function >> gets called. This introduces a new annotation for those functions to make >> them either 'inline' or 'noinline' dependning on the CONFIG_KASAN symbol. >> >> Signed-off-by: Arnd Bergmann >> --- >> include/linux/compiler.h | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/include/linux/compiler.h b/include/linux/compiler.h >> index f8110051188f..56b90897a459 100644 >> --- a/include/linux/compiler.h >> +++ b/include/linux/compiler.h >> @@ -416,6 +416,17 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s >> */ >> #define noinline_for_stack noinline >> >> +/* >> + * CONFIG_KASAN can lead to extreme stack usage with certain patterns when >> + * one function gets inlined many times and each instance requires a stack >> + * ckeck. >> + */ >> +#ifdef CONFIG_KASAN >> +#define noinline_for_kasan noinline __maybe_unused > > > noinline_iff_kasan might be a better name. noinline_for_kasan gives the impression > that we always noinline function for the sake of kasan, while noinline_iff_kasan > clearly indicates that function is noinline only if kasan is used. FWIW we may be facing the same problem with other compiler-based tools, e.g. KMSAN (which isn't there yet). So it might be better to choose a macro name that doesn't use the name "KASAN". E.g. noinline_iff_memtool (or noinline_iff_memory_tool if that's not too long). WDYT? >> +#else >> +#define noinline_for_kasan inline >> +#endif >> + >> #ifndef __always_inline >> #define __always_inline inline >> #endif >> > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To post to this group, send email to kasan-dev@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/7e7a62de-3b79-6044-72fa-4ade418953d1%40virtuozzo.com. > For more options, visit https://groups.google.com/d/optout. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg