From nobody Fri Sep 20 18:34:27 2024 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DCBEC7EE31 for ; Thu, 1 Jun 2023 15:19:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234580AbjFAPT1 (ORCPT ); Thu, 1 Jun 2023 11:19:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234915AbjFAPTD (ORCPT ); Thu, 1 Jun 2023 11:19:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C626DB3; Thu, 1 Jun 2023 08:18:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5F85664675; Thu, 1 Jun 2023 15:18:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C525FC4339C; Thu, 1 Jun 2023 15:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685632727; bh=zt7KZMmx/oJBYdfFdtNG8ZQh916ADU8eGaXVMVWxHLE=; h=From:To:Cc:Subject:Date:From; b=lOsYcDeZ6FDbxshIu7kdv+ump9fNlSvRpNRm6K6kLV3mxZKqoX7/SeZaOn5gv9gYd jUGbk6YWUoRlA6uXYqUPeKRY+B/G7Gtt6DRjGqb/rofNXy1cgD4lv6tend69ihuddC /Xs5cKYacjSj7o/Ch3PcbC+S5wqM/cwEt5cNvibv8wmRxcg74v43euAPEUPlY7fG5a I0xFlAuT7pGfRRlcmRdc3Ln/9JyPCzJ1R8eqd4eYbhqcuvyFxOQPjvsczQhU1vqyNd nWIyEt9HR0ur9SlpXBuqSzw77gRjWK2aT6fdvn0eK1AeOTk3eXPGF0sk7UpCqBMB8s Un4YXvEvE8kcg== From: Arnd Bergmann To: kasan-dev@googlegroups.com, ryabinin.a.a@gmail.com Cc: glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, vincenzo.frascino@arm.com, elver@google.com, linux-media@vger.kernel.org, linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au, ardb@kernel.org, mchehab@kernel.org, Arnd Bergmann , Dan Carpenter , Matthias Brugger , AngeloGioacchino Del Regno , Nathan Chancellor , Nick Desaulniers , Tom Rix , Kees Cook , Josh Poimboeuf , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, llvm@lists.linux.dev Subject: [PATCH] [RFC] ubsan: disallow bounds checking with gcov on broken gcc Date: Thu, 1 Jun 2023 17:18:11 +0200 Message-Id: <20230601151832.3632525-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann Combining UBSAN and GCOV in randconfig builds results in a number of stack frame size warnings, such as: crypto/twofish_common.c:683:1: error: the frame size of 2040 bytes is large= r than 1024 bytes [-Werror=3Dframe-larger-than=3D] drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_req_lat_if.c:1589:1: e= rror: the frame size of 1696 bytes is larger than 1400 bytes [-Werror=3Dfra= me-larger-than=3D] drivers/media/platform/verisilicon/hantro_g2_vp9_dec.c:754:1: error: the fr= ame size of 1260 bytes is larger than 1024 bytes [-Werror=3Dframe-larger-th= an=3D] drivers/staging/media/ipu3/ipu3-css-params.c:1206:1: error: the frame size = of 1080 bytes is larger than 1024 bytes [-Werror=3Dframe-larger-than=3D] drivers/staging/media/rkvdec/rkvdec-vp9.c:1042:1: error: the frame size of = 2176 bytes is larger than 2048 bytes [-Werror=3Dframe-larger-than=3D] drivers/staging/media/rkvdec/rkvdec-vp9.c:995:1: error: the frame size of 1= 656 bytes is larger than 1024 bytes [-Werror=3Dframe-larger-than=3D] I managed to track this down to the -fsanitize=3Dbounds option clashing with the -fprofile-arcs option, which leads a lot of spilled temporary variables in generated instrumentation code. Hopefully this can be addressed in future gcc releases the same way that clang handles the combination, but for existing compiler releases, it seems best to disable one of the two flags. This can be done either globally by just not passing both at the same time, or locally using the no_sanitize or no_instrument_function attributes in the affected functions. Try the simplest approach here, and turn off -fsanitize=3Dbounds on gcc when GCOV is enabled, leaving the rest of UBSAN working. Doing this globally also helps avoid inefficient code from the same problem that did not push the build over the warning limit. Reported-by: Dan Carpenter Link: https://lore.kernel.org/stable/6b1a0ee6-c78b-4873-bfd5-89798fce9899@k= ili.mountain/ Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110074 Link: https://godbolt.org/z/zvf7YqK5K Signed-off-by: Arnd Bergmann --- lib/Kconfig.ubsan | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index f7cbbad2bb2f4..8f71ff8f27576 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -29,6 +29,8 @@ config UBSAN_TRAP =20 config CC_HAS_UBSAN_BOUNDS_STRICT def_bool $(cc-option,-fsanitize=3Dbounds-strict) + # work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110074 + depends on GCC_VERSION > 140000 || !GCOV_PROFILE_ALL help The -fsanitize=3Dbounds-strict option is only available on GCC, but uses the more strict handling of arrays that includes knowledge --=20 2.39.2