From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CBCC21BD9F0; Wed, 30 Apr 2025 23:13:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746054791; cv=none; b=ISYyOzAXY12Hc7DNtaUugjCVDv33QoK1efVC5bxZcE68Wyxjx4CGMKkgSHtaR/IgkSJxD0CeAao/GfhJIbhWq6ZlmrkGa4W68qaT4fN6dm29vqA65PWxq4Xrkxc5uVYZWxXH8BxLhTwAiqxQW1+CnkiMw5O+V4gwyS8uzvOBczE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746054791; c=relaxed/simple; bh=6xTUkRpTKfzrPwISqOi/AA76CXWhSy1rPF2+jMsRpPk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rNtYLz9J92JC3u3jSsO6c4HB4zfndI5BcsjLvCsMeJ6dVUAkP4gDZcLID0QEX1n9jbS1+AIxt3Lscb7fWTWRFgEQTRfdq/nKMGTOm9Rh5Mdqmtv9taueBEVGbU0r46IOXPE6i7Hy5EqmhBc9zWmYMV+7OahQ42fxpsadKW7lWeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=D7weV58x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="D7weV58x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AC4FC4CEE7; Wed, 30 Apr 2025 23:13:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746054791; bh=6xTUkRpTKfzrPwISqOi/AA76CXWhSy1rPF2+jMsRpPk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=D7weV58xBGO8RfEmcQBFhYpSWBCIx/mNXDR/8+Im/1xK0fQnPsdy5OuBESJim2/9o YLsV0MGpJuPKgUy49EgNnXghzHvySjymS3joaYx1EzJAkkBwOMZ5+xDuRobNOe5KU2 OeP9Qjnc/ENatkz1sVTHVLIYvKhez2WMJjJuXk5rEsWECeKYyQXV6rT9Czn9k1IyjC +4qz7rJLOyKAsIB+LCuIsVI4c2FMOT8zfgFajkUY7tUPjjk2uEU60pDAdeHpMnlN6n YqJnS+oUmX8WhgKM8iqH5lb1q/3IQ1j7BhKW0gUeYN1/oNyp4UKsd6QBLzPxVH7cxO B5rk2mMCZAdaQ== Date: Wed, 30 Apr 2025 16:13:06 -0700 From: Nathan Chancellor To: Jan Hendrik Farr Cc: Kees Cook , Miguel Ojeda , Bill Wendling , thorsten.blum@toblux.com, "Gustavo A . R . Silva" , Nick Desaulniers , Justin Stitt , linux-hardening@vger.kernel.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] hardening: simplify CONFIG_CC_HAS_COUNTED_BY Message-ID: <20250430231306.GA3715926@ax162> References: <20250430184231.671365-1-kernel@jfarr.cc> <20250430184231.671365-2-kernel@jfarr.cc> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250430184231.671365-2-kernel@jfarr.cc> On Wed, Apr 30, 2025 at 08:42:31PM +0200, Jan Hendrik Farr wrote: > Simplifies CONFIG_CC_HAS_COUNTED_BY by removing the build test and > relying solely on gcc/clang version numbering (GCC_VERSION >= 150100 and > CLANG_VERSION >= 190103). > > The build test was used to allow unreleased gcc 15.0 builds to use the > __counted_by attribute. Now that gcc 15.1.0 has been released, this is > not needed anymore. Note: This will disable __counted_by on unreleased > gcc 15.0 builds. > > clang version support for __counted_by remains unchanged. > > Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b > Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc > Suggested-by: Nathan Chancellor > Signed-off-by: Jan Hendrik Farr Reviewed-by: Nathan Chancellor > --- > init/Kconfig | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 63f5974b9fa6..017fde21d0ba 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -121,13 +121,14 @@ config CC_HAS_NO_PROFILE_FN_ATTR > def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) > > config CC_HAS_COUNTED_BY > - # TODO: when gcc 15 is released remove the build test and add > - # a gcc version check > - def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror) > + bool > # clang needs to be at least 19.1.3 to avoid __bdos miscalculations > # https://github.com/llvm/llvm-project/pull/110497 > # https://github.com/llvm/llvm-project/pull/112636 > - depends on !(CC_IS_CLANG && CLANG_VERSION < 190103) > + default y if CC_IS_CLANG && CLANG_VERSION >= 190103 > + # supported since gcc 15.1.0 > + # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 > + default y if CC_IS_GCC && GCC_VERSION >= 150100 > > config CC_HAS_MULTIDIMENSIONAL_NONSTRING > def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror) > -- > 2.49.0 >