From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792535723; b=Jm/nayMBkpVGb4uvxPQTQo920yIDjzsR5LOkNxkKyzD1F1VJuJU9qH+YrEXqFvuzTBrm nOi+b+Ay3viLP86sN7PBkC+08L4Nds2xCh38RpfiadxwfXZWsAo6qTtnKt69D8INUivJj b5TLYKVSq7KwYsIqlt+WhXPfOI6Luj6HG+m9nwoDm9XeeoMUH6AY4Lx+6EP21j0SxoOiF IEZfWcl3YNbMZ7hivyrcZJqG/4X2tsQf0LIFQYbkTw1evrcIAnVXNN5Xh/+ET2Dyxt7eH HSS8NaaovQ278zgKdPi+ZbO6UBMsLReKeYDCODmEFZUtyg7xNS8/T2p1hYyn0mpfXbw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792535723; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=jTVej4XiZHu2/J1IznIB6FnyFrgfuyNpPk/uLcIpGv0=; b=3bOBQpXWSoIb372/11hCGTNgk41pVykX4jkNL57avyATpRw08zEgqheswNGGThvcIxdJ abHIyybYtEQixBM64NnBq/G92IQ7nP8DIJsHUMNP30lc+hwrv18Gi7Ff/wCew9J2oV+oU dh9iCgwvcjxOjTG6xmNhLS3DBOYyzKf10YacgWiq+epecGIMlIYgfkCPF/8/Vhvnnf4fB 76WDp9Xu9hDXrA2iVQB4cPjzjbvqjbJH7MClUVNwGqC82QhtT8PSSGjFtAmsEE8I8Mw0Z pn4t3Kb+RJupbSX+DnLcviIQfs3djntwY4PO/AUq/8GT7VbK2jiMOfPS/XkIFPRAN/A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=gSeqoUOe; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF167606A31A for ; Tue, 20 Oct 2026 22:35:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=gSeqoUOe Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDA841F000C9; Tue, 20 Oct 2026 22:35:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792535722; bh=jTVej4XiZHu2/J1IznIB6FnyFrgfuyNpPk/uLcIpGv0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=gSeqoUOewGKTWyYAtu8nVdElVqXDvVRkPsEPHYaDPOl2NMvZSFMk/D4v4iS/vtiAj 25rMDAAWwPleYk4s/eyvlGNOBOumwVdhWwDD2SyUf2WkBJqBtnWvf4SDwaUguBdiS8 Xw7sS2EZkguh3YsLP8navyK+XIR5UBvy2H9Bl/+bdeDYWFSi66VuaZHJx18Kl/SeKH A+U5lUKsqdmZUVyWGtnXIojOByvqC/nYiUti1lcKPSBhEnGA3fnTMAXl7vcIzr+1Ct ltqxre8xZXGWK9kBBc6/EyHh/pgggovMy81nZXa/cXUiokuvT/ikIif8F0LcYA/XCW NE0fvNxV+A9DQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 1/2] kbuild: Move testing of '-mfentry' back to Makefile from Kconfig Reply-To: sashiko-reviews@lists.linux.dev To: "Nathan Chancellor" Cc: linux-s390@vger.kernel.org, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261020-kconfig-fix-mfentry-check-v1-1-428258bc0fc0@kernel.org> References: <20261020-kconfig-fix-mfentry-check-v1-0-428258bc0fc0@kernel.org> <20261020-kconfig-fix-mfentry-check-v1-1-428258bc0fc0@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 20 Oct 2026 22:35:21 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Unlike cc-option in Kbuild, cc-option in Kconfig does not test options > with either bit ('-m32' / '-m64') or endianness ('-mbig-endian' / > '-mlittle-endian') flags because which flag to use may depend on the > result of the configuration stage. This difference changes the result of > testing for '-mfentry' support when using the kernel.org s390 cross > compiler, which is configured for 32-bit by default. >=20 > $ s390-linux-gcc -mfentry -o /dev/null -x c -c /dev/null > cc1: error: '-mfentry' is supported only for 64-bit CPUs >=20 > arch/s390/Makefile sets '-m64' in KBUILD_CPPFLAGS early, so '-mfentry' > support was properly tested before the move to Kconfig. >=20 > $ s390-linux-gcc -m64 -mfentry -o /dev/null -x c -c /dev/null >=20 > Ricardo reported another issue with moving this check from Kbuild to > Kconfig, as '-mfentry' is not supported for x86_32 without '-fno-pic', > which affects GCC builds that are configured with PIE enabled by > default. arch/x86/Makefile adds '-fno-pic' to KBUILD_CFLAGS, so this > works properly in Kbuild. >=20 > Move the '-mfentry' check back into Kbuild to avoid adding additional > complexity to the Kconfig entry. >=20 > Fixes: 454e00cf8ee5 ("kbuild: avoid re-running compiler and linker probes= ") > Reported-by: Ricardo Ribalda > Closes: https://lore.kernel.org/20261020-pie-v1-1-9be09f2324b1@chromium.o= rg/ > Signed-off-by: Nathan Chancellor Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261020-kconfig-fi= x-mfentry-check-v1-0-428258bc0fc0@kernel.org?part=3D1