From nobody Sat Oct 4 14:33:04 2025 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 6227F19AD8B; Fri, 15 Aug 2025 01:31:52 +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=1755221512; cv=none; b=kf6pWEmPBZCX+GjYHL0/c4Pc/MdLELYXrybshiaa2nHXwwCGGfiSY0PfMcHJEucOWXZHzFKthQxAhFyIPV/bSkx8PoRmAELOgx1FxA6lggjIqo/ea6kGX5j/EQLrk3tdbxtwjOzOr9VI7/PtH9Z5ZO6xEKIviiPCRGQ0s0FpNe4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221512; c=relaxed/simple; bh=X/zutVL5lxxntjtByHEizcL/TjX/yUfbMYCdIp0zOCY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kUJzSPIIh/JDG01cA3JZEOLRWNOBKXuTdXslpZpTKloaT9kH6JXnq6hyVCWpzzinE/l9SoTCTMGW8Gyr+dK4CDYRFJAha+KUXHuYV7nDYzdiv7939ThcwXn7ZAtWy07SgNF4xbJpPiR+Q3wp0xIlipaNNFJdMzTP0O5oAJpv19U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aV3WhqNx; 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="aV3WhqNx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B686C4CEF6; Fri, 15 Aug 2025 01:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221511; bh=X/zutVL5lxxntjtByHEizcL/TjX/yUfbMYCdIp0zOCY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=aV3WhqNxNJcmTUyRmvYM6XxdICA7KHoblr2D+lexZomSOnzEAzEQz9nJ1uxbeq175 1b7kKVluGxZnsN6iYL7quT7JT0urfxd/NmDqzy8IjVDgXtYy9I81A37p8mOr/XD2Pk ve1JaZbaZQI0pUsr9DayxGXzPwoz7TTfQ65B9cj0q1cLChsKMcelxjZxsL/5Mk+29E E1FDb2HdBSAmu8AHvWRcwVk/Cny0ZZNkqiwze9nXRk3VaT8QnDOz+os17VfOmfhVMJ 0eyVgG3ImrMerPfgNh2+xzq+L3pachVPRu3PtO4Ap9RKcbUwaMnMkRspH5d+S9mHW+ 2tFHayjdbd61w== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:37 -0700 Subject: [PATCH 1/6] x86/build: Remove cc-option for GCC retpoline flags Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-1-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1317; i=nathan@kernel.org; h=from:subject:message-id; bh=X/zutVL5lxxntjtByHEizcL/TjX/yUfbMYCdIp0zOCY=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+phlmipn/lmVtWL9uW+BlwJeuQpkNDK0XeWJ0fRSC wr5wHKro5SFQYyLQVZMkaX6sepxQ8M5ZxlvnJoEM4eVCWQIAxenAExkaS/D/6JHXE5dSjq2u253 n994zEDY2vdwvOx5nunzJ+a0WcelvWFkmL50cW/cDh7nD8Vvtn1mKTyi6fKpJaBrSm3F51VO9Vf zWQA= X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 The minimum supported version of GCC to build the x86 kernel was bumped to GCC 8.1 in commit a3e8fe814ad1 ("x86/build: Raise the minimum GCC version to 8.1"). '-mindirect-branch' and '-mindirect-branch-register' were first supported in GCC 8.1, so there is no need to call cc-option to inquire if it is supported. Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3Dda99fd4a3ca06b43b= 08ba8d96dab84e83ac90aa7 Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3Dd543c04b795f8af4e= be5b3d5f38156ef4e5734f1 Signed-off-by: Nathan Chancellor --- arch/x86/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 1913d342969b..ed5657395d6a 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -13,8 +13,8 @@ else endif =20 ifdef CONFIG_CC_IS_GCC -RETPOLINE_CFLAGS :=3D $(call cc-option,-mindirect-branch=3Dthunk-extern -m= indirect-branch-register) -RETPOLINE_VDSO_CFLAGS :=3D $(call cc-option,-mindirect-branch=3Dthunk-inli= ne -mindirect-branch-register) +RETPOLINE_CFLAGS :=3D -mindirect-branch=3Dthunk-extern -mindirect-branch-r= egister +RETPOLINE_VDSO_CFLAGS :=3D -mindirect-branch=3Dthunk-inline -mindirect-bra= nch-register endif ifdef CONFIG_CC_IS_CLANG RETPOLINE_CFLAGS :=3D -mretpoline-external-thunk --=20 2.50.1 From nobody Sat Oct 4 14:33:04 2025 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 46AC91A9B53; Fri, 15 Aug 2025 01:31:54 +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=1755221514; cv=none; b=YFgdSZfs12Mvc2WbXKHKPuQjfiUKTmZehOEcuFMhuDSPjXlSHC5gS3O22zmziDxkrovlHIX9jlbv5IYSPM93vTKbp+AA90CDNGjdgwm+xu4jOlMfrnXtuZoj8KjvHkIdGJI0zDuSuFV8UokfwXK+Orj41eyX6YIroT1qZdI8ZpI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221514; c=relaxed/simple; bh=mZKg/HKBlbq+tlm3qWX2x6vIoBEhFQs2e30B2TkZCWs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kqucek+rv8AoEDyGAVvGXcbeYtb1R6m89KzWQ08IIBDGVPe4oOLGaJo7Tx8M6LU+DKwgQkyzTTlPUWbubiVex85UjMU9oNBXcP4cD/G0WACbwx+oOHx5UfuzCox21X2S53sfOq4afa0P1Peir+cTV3iAzeLpYLM8A2DKKdKlPC0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WOVt3QMI; 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="WOVt3QMI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 508A5C4CEED; Fri, 15 Aug 2025 01:31:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221514; bh=mZKg/HKBlbq+tlm3qWX2x6vIoBEhFQs2e30B2TkZCWs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=WOVt3QMI/C/doXO2+GERrhw5jGu/qAeM1gF7taMSix+Pg9DiNCg8ej8ZfiMRlhEi9 bQ+qJdZQonW4tmNXdmBTVcz/l2TLm29Ilo141/6xPl+5HyppgjH+B+2XOjxkKF/qE2 trAz7wSkCmb/eionR4FZw4bYixJmg8Sz4jDgITCkHSO7MIDvGSoGaivnN33wG0JOst evCkD0xG/0wKDJdGsVZDXF7XYuoh55tSJOOXv7keQaFAmFzA2Veo1CljpCkOYn2XQb BOXxwAaE1P45h/hUSEdVGVgR+ynrPNKmTcr7n5QhdFVP4CoH1xKeildPhIDocbW5cP jX1DwDoNTihZQ== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:38 -0700 Subject: [PATCH 2/6] x86/build: Remove cc-option from stack alignment flags Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-2-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1352; i=nathan@kernel.org; h=from:subject:message-id; bh=mZKg/HKBlbq+tlm3qWX2x6vIoBEhFQs2e30B2TkZCWs=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+piXCwZdfnOufioPxwnPVO8Ji1iSHyrEM26ZbpB1p bja8TR7RykLgxgXg6yYIkv1Y9XjhoZzzjLeODUJZg4rE8gQBi5OAZhICwsjw6yfa9dt0K9zL+U+ vFJf8bntTybPvtqJ614k3kh3fXL/2BWG32ycfe5WlrulBF9asL5edeKafMD7lxtFFvaZnd+5ccL Fy+wA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 '-mpreferred-stack-boundary' (the GCC option) and '-mstack-alignment' (the clang option) have been supported in their respective compilers for some time, so it is unnecessary to check for support for them via cc-option. '-mpreferred-stack-boundary=3D3' had a restriction on '-mno-sse' until GCC 7.1 but that is irrelevant for most of the kernel, which includes '-mno-sse'. Move to simple Kconfig checks to avoid querying the compiler for the flags that it supports. Signed-off-by: Nathan Chancellor --- arch/x86/Makefile | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index ed5657395d6a..f0aa58d2ec17 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -37,10 +37,11 @@ export RETPOLINE_VDSO_CFLAGS =20 # For gcc stack alignment is specified with -mpreferred-stack-boundary, # clang has the option -mstack-alignment for that purpose. -ifneq ($(call cc-option, -mpreferred-stack-boundary=3D4),) +ifdef CONFIG_CC_IS_GCC cc_stack_align4 :=3D -mpreferred-stack-boundary=3D2 cc_stack_align8 :=3D -mpreferred-stack-boundary=3D3 -else ifneq ($(call cc-option, -mstack-alignment=3D16),) +endif +ifdef CONFIG_CC_IS_CLANG cc_stack_align4 :=3D -mstack-alignment=3D4 cc_stack_align8 :=3D -mstack-alignment=3D8 endif --=20 2.50.1 From nobody Sat Oct 4 14:33:04 2025 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 9B2421C5D44; Fri, 15 Aug 2025 01:31:56 +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=1755221516; cv=none; b=ZvsIMqhIF/mvC6G2eT/6Lsh1khZ1/xGvo5hZ6SGtALIdBD6GdI4Y/s2AvCctT7BomkNQQUfU4OwUxDdjWjI0yde5W/7fEDGJU84UzyrGkfOM5PyP9b6DvWn5UBEta9hWxEwJjhhNXULgadzpLpeblsN3Ppy8t7tceASCWVxOmo8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221516; c=relaxed/simple; bh=wsYRUWlX9PDsovfpyWwlin/E7wFWkuTbNk77f6srOmc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=dtK2J7bkiu9/c9LyZleJvN93RpElmtSjvKyhw7RJiZUxRuusPkPRGg9i6X4gU93ZpegkZDses4BW3RESamgjgm61kWAqNTD5R+H988y5GoQsLdpM99yTxDZD/SWvcPhTnCkGqIhbr1UoNyvqftzpgCuCSiTF0Dx8JDYgFxrGP3o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cn2SvjDG; 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="cn2SvjDG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75DC9C4CEF1; Fri, 15 Aug 2025 01:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221516; bh=wsYRUWlX9PDsovfpyWwlin/E7wFWkuTbNk77f6srOmc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=cn2SvjDGcZkggmUfYcXLxTPeqGoT+6pGl+7mAOfG3bDzW+h0Uq14qgto34ga/qa+G yrMxQCn+g/lW/7ciOS+xvjQxB9nOHMtR3gW9PRISa/vlmmpwg8n9PcgmdNlh9Z5Vru 0KRFdm1Zy1g7XbBmMlddK3RWN6KLiDxq0z0Hct8n6imPVdAecaes22+xVxU3FdkGGT G6ZaYB8pBeXX28CSKigpebu18LCnmnewZ27juT849qR1pskQotv2BQ8puVgR9S7gSe Owt8lQxgxQ5pRf6Y8U1KjODzvSqMiSh/Fj4BCpKJw1dYu67oQRcshoCFHPrVM/d8xO CrDKzg16mmJoQ== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:39 -0700 Subject: [PATCH 3/6] x86/build: Clean up stack alignment flags in CC_FLAGS_FPU Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-3-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1679; i=nathan@kernel.org; h=from:subject:message-id; bh=wsYRUWlX9PDsovfpyWwlin/E7wFWkuTbNk77f6srOmc=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+pgFdjh2p2+rbJt5js/7c/YDXr30hJbPmlnGn6aGX rg97eeLjlIWBjEuBlkxRZbqx6rHDQ3nnGW8cWoSzBxWJpAhDFycAjARdx9GhhnbHvSavPyatjwj qD/ffLLr3MnG/5S3vlI5zTD3IP+mx3MZ/llnX94wX926+Xwph9DF+/KVwe+2uVbk71zdkMrEZHP dhgcA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 The minimum supported version of GCC to build the x86 kernel was bumped to GCC 8.1 in commit a3e8fe814ad1 ("x86/build: Raise the minimum GCC version to 8.1"). Prior to GCC 7.1, '-mpreferred-stack-boundary=3D3' was not allowed with '-msse', so areas of the kernel that needed floating point had a different alignment. Now that GCC > 7.1 is mandatory, there is no need to have a different value of '-mpreferred-stack-boundary' from the rest of the kernel, so remove this handling from CC_FLAGS_FPU. Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3D34fac449e121be97d= d073c5428cc855367b2872c Signed-off-by: Nathan Chancellor --- arch/x86/Makefile | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index f0aa58d2ec17..0c82a610fb54 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -84,19 +84,7 @@ KBUILD_RUSTFLAGS +=3D -Ctarget-feature=3D-sse,-sse2,-sse= 3,-ssse3,-sse4.1,-sse4.2,-av # CC_FLAGS_FPU :=3D -msse -msse2 ifdef CONFIG_CC_IS_GCC -# Stack alignment mismatch, proceed with caution. -# GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-bound= ary=3D3 -# (8B stack alignment). -# See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D53383 -# -# The "-msse" in the first argument is there so that the -# -mpreferred-stack-boundary=3D3 build error: -# -# -mpreferred-stack-boundary=3D3 is not between 4 and 12 -# -# can be triggered. Otherwise gcc doesn't complain. CC_FLAGS_FPU +=3D -mhard-float -CC_FLAGS_FPU +=3D $(call cc-option,-msse -mpreferred-stack-boundary=3D3,-m= preferred-stack-boundary=3D4) endif =20 ifeq ($(CONFIG_X86_KERNEL_IBT),y) --=20 2.50.1 From nobody Sat Oct 4 14:33:04 2025 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 C1DE11C862C; Fri, 15 Aug 2025 01:31:58 +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=1755221518; cv=none; b=f7X7i5KwKthVYyId+xaf/Aunj47z/V4t86EOOo8tdTgzY7YQIxX9S2cJ8NyrMLyAMgj5RvdKccBZGmY8bn+x6v+5UXiut0mPpKp0dNWmJyqZ9sj4aLPIhUY0535xfS8ZHjFE3RYWm3KHALkGhQgUj2q8ozW0C9jET1UXg1NyTho= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221518; c=relaxed/simple; bh=rX1yO3lw6hmqgveY9Hg/MQWB/db5ofT9N4FvgY1/6P4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=INKHdTdM6Aus7zI5TABXzUpU4AWz27oW+NM/JdcD7WvWcu24cwb3JRYEe6vtr6epNXHwkvIKZnamVhf8OeUCDKLgMmJMwjYPwwUqKHPV2J1l+uk+fJrZLyiUUBeNiGUhf9dbUJM8WcWt4EPTkTgxtrk5nUbKJoeS4ovFRCqsPjE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JABKOMnX; 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="JABKOMnX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AFBEC4CEF5; Fri, 15 Aug 2025 01:31:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221518; bh=rX1yO3lw6hmqgveY9Hg/MQWB/db5ofT9N4FvgY1/6P4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JABKOMnXvolAoK0Vu/DNyXoGCjzGupBYhxBPbIiwLEsTUgGUj1F9E9dsZsUbo4iQQ o/vQiUpGOeQGu1qBxu9r0JkWc6IyOZZhg2wKNIA0FRn7gi32skbboAakuXb4ExoNbX sg3IU5CR0ulLoNPlllz+adEsVpWkoAi5FkPvHNYf1dURI/6soonZiNxFTUkBZxgsOf XR3s0Of5W21l+w01vtbpcDjNc241yAXBOyhTKuKMsBLm4I9vfaAmz+aL5K2P18+TIs WlxU+3+5++at1Q1g/tJCKKRgmKyfXPU2Ph7u/yJwD8npbJhy+7rb1oymm56geWk2yu aDuYwCtVJUr0Q== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:40 -0700 Subject: [PATCH 4/6] x86/build: Remove cc-option from -mno-fp-ret-in-387 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-4-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1097; i=nathan@kernel.org; h=from:subject:message-id; bh=rX1yO3lw6hmqgveY9Hg/MQWB/db5ofT9N4FvgY1/6P4=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+phnXmBmfsK2cal3056we2wzP1n++aLTuvDP87y5P LyB+cZWHaUsDGJcDLJiiizVj1WPGxrOOct449QkmDmsTCBDGLg4BWAi3GyMDPuXXd1sFl2w34Ln kqNV+YJwxxbmckmerYqs4j3FF73WXGP4K6FYstU4T+aw/YlT3XdN7O+rH88QzLssco753mrJ4i9 9LAA= X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 This has been supported in GCC for forever and clang gained support for it as an alias of '-mno-x87' in LLVM 14. Now that x86 requires LLVM 15 or newer since commit 7861640aac52 ("x86/build: Raise the minimum LLVM version to 15.0.0"), this flag can be unconditionally added, saving a compiler invocation. Link: https://github.com/llvm/llvm-project/commit/a9fba2be35db674971382e38b= 99a31403444d9bf Signed-off-by: Nathan Chancellor --- arch/x86/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 0c82a610fb54..1bbf943fe9e1 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -148,7 +148,7 @@ else =20 # Don't autogenerate traditional x87 instructions KBUILD_CFLAGS +=3D -mno-80387 - KBUILD_CFLAGS +=3D $(call cc-option,-mno-fp-ret-in-387) + KBUILD_CFLAGS +=3D -mno-fp-ret-in-387 =20 # By default gcc and clang use a stack alignment of 16 bytes for x= 86. # However the standard kernel entry on x86-64 leaves the stack on = an --=20 2.50.1 From nobody Sat Oct 4 14:33:04 2025 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 EFAA81D90DD; Fri, 15 Aug 2025 01:32:00 +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=1755221521; cv=none; b=EOjGN5pHOBZvVk5VGQua1xJeYYlIgUdFuo4fXbar71FVOrk39PkkWcN4ae8641X7O1D6iWNHSIASWNfs5uT9UrW8paJvEaDikAJJnFREHHaxg5Yv97smsnvAgIm4h8b6EjdsqVwt1gjEyFCWeBgAMMtLp+NkDxLNFmj3aKRs2qs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221521; c=relaxed/simple; bh=2LiwU3rKNVfQm7cDElYzRKByvRhLx0N2Of74XMmo2eY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PkjcTsLel7iP49qbtH1HIC/MToqRJiuK8bxOldtMKAK4FP/pOqUu/PXPG0A6bsuS6k0LxAwifgx9U8T/5ilaN9oUpgnej3ZHIhz/B/8ZdcLLwcZqGLAOooAMIke8u+39tGLPV/icLhf5huqrvc4THr9KZhC2H6L4IG25HkyHmmU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j5Yi8a1i; 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="j5Yi8a1i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C00B8C4CEED; Fri, 15 Aug 2025 01:31:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221520; bh=2LiwU3rKNVfQm7cDElYzRKByvRhLx0N2Of74XMmo2eY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=j5Yi8a1iN6W2uL+kkTuODZsGctpofF1xA8V1c7cmasOm4+EpHAQLUgeFWuZKnEf5N iCGvmrtihuJ6MT3nNpIZipDXmhJDTE4MVSL5b92h4Fewk0AF8yEwZUOESUEFyrYBhO 4DP6SD+Y2bDgthrrBPZfffbiOpUYKkPmoqKJHgjBijGjbb/j4NWqJpEyiyLLpfpKkF eKzD2x8okdYCzDJFJutgiL5HWIIQQa08gOViC7bM6YfVqcod7OUkbgZ5WndvQzYZ+P F3pcrw1n/gPiFu0o82AC426jMM+zqUGFMU/EtTJBk54ElE6+LAogubXtZWniW1/MvO VxPokFp1pzSnA== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:41 -0700 Subject: [PATCH 5/6] x86/build: Remove cc-option from -mskip-rax-setup Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-5-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1022; i=nathan@kernel.org; h=from:subject:message-id; bh=2LiwU3rKNVfQm7cDElYzRKByvRhLx0N2Of74XMmo2eY=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+pgv3Jl28cLssxkqF0OyRHUzjSfOOrol9s1Kf3HDO VXGcSnrOkpZGMS4GGTFFFmqH6seNzScc5bxxqlJMHNYmUCGMHBxCsBE+nkYGfZtyjWbLhbvG7Pg jPUpRy+OecI/mo07UwPTM0/+8BQVZ2X4zerQ8ivHb8Pyb/Pmxuqb68z1iKm2ksiXcZm5oObHTd8 kHgA= X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 This has been supported in GCC since 5.1 and clang since 14.0. Now that x86 requires LLVM 15 or newer since commit 7861640aac52 ("x86/build: Raise the minimum LLVM version to 15.0.0"), this flag can be unconditionally added, saving a compiler invocation. Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3Dfbe575b652f5bdcc4= 59f447a0e6f0e059996d4ef Link: https://github.com/llvm/llvm-project/commit/a9fba2be35db674971382e38b= 99a31403444d9bf Signed-off-by: Nathan Chancellor --- arch/x86/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 1bbf943fe9e1..4b4e2a3ac6df 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -160,7 +160,7 @@ else KBUILD_CFLAGS +=3D $(cc_stack_align8) =20 # Use -mskip-rax-setup if supported. - KBUILD_CFLAGS +=3D $(call cc-option,-mskip-rax-setup) + KBUILD_CFLAGS +=3D -mskip-rax-setup =20 ifdef CONFIG_X86_NATIVE_CPU KBUILD_CFLAGS +=3D -march=3Dnative --=20 2.50.1 From nobody Sat Oct 4 14:33:04 2025 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 193431DF261; Fri, 15 Aug 2025 01:32:02 +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=1755221523; cv=none; b=M4sjiSN1cXjyWyCIcvpHYhhGo5H+ooBr10pXZLlgQ/uDmVOH5tJqiqghQQv+eewGBt2S5nQLWJV7npaQ0D2EqcP+dKsEFlYFmPcLVq5/ekSlULRKC+xCTrxSVjXf+AzAELYl+RibIAPFNaYw+mtxREPNLv2SiGsDlktR4HhXpxk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755221523; c=relaxed/simple; bh=ymuAyPYY672se8t4t301XszaRQHED0MEWCBoF0HZS3A=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=RkaJG5WdsOpkhWThzL8TAdtOr9v/KCGaFuxLZbSp/lwsxESTB0M6g3BKZni4c5JPHgTzDvvtI0fF/5rP0L0qHq5GHtMTnwyNQ5XMeWmC1A0IIwf7jQ6U4UePQMT9+wRx9A/arIUYqxdn/LS9mNgS2CY1G44pv7x0a97lfXViZFY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=irM2ACac; 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="irM2ACac" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E590FC4CEF5; Fri, 15 Aug 2025 01:32:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755221522; bh=ymuAyPYY672se8t4t301XszaRQHED0MEWCBoF0HZS3A=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=irM2ACac0S7o3Uzris8xVq3PQHhxs0ngihn8jXcf4r5M6YswNjOTGczAC3G9bulwY zSHjGAmpSz2oN+glC3ZT1og0ONSw6a64mTOt9DFBK018TXYzy617/6MHmY8RwLqCYk 0Ah7xqveOnuS3mufEgZ76jz6MYY202b17p8zuTmPiWXIiLZAA9gLumDdKhXIw9NoI2 JPj61GYkqdSQ9r9r8M5YsXso7+gGc84/bl97/U6t/kBwHXMQlwFLFviP/7M8KkHSGV fSWbeBtE8WHZMYMNHJSrjXmeN0VAbRzb73eNWjX213GCVQFrrs3h4W0PfpnJjBOYTB oWrTQl8meg1/Q== From: Nathan Chancellor Date: Thu, 14 Aug 2025 18:31:42 -0700 Subject: [PATCH 6/6] x86/Kconfig: Clean up LLVM version checks in IBT configurations Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250814-x86-min-ver-cleanups-v1-6-ff7f19457523@kernel.org> References: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> In-Reply-To: <20250814-x86-min-ver-cleanups-v1-0-ff7f19457523@kernel.org> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1589; i=nathan@kernel.org; h=from:subject:message-id; bh=ymuAyPYY672se8t4t301XszaRQHED0MEWCBoF0HZS3A=; b=owGbwMvMwCUmm602sfCA1DTG02pJDBnz+pi3NdbsMBEOfHXUWDQ0xTxPPZlH4Ead6p2LFyO+v dH3nni6o5SFQYyLQVZMkaX6sepxQ8M5ZxlvnJoEM4eVCWQIAxenAExkeT8jQ6u5oLjYGan15hUi ke0fzU5oW3v5zFYT3V8QKCunt+jjbUaGycGnN/G0btlsOHXFdRthltiJ3CWrVsZyz5lwLvZGvvB JFgA= X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 The minimum supported version of LLVM for building the x86 kernel was bumped to 15.0.0 in commit 7861640aac52 ("x86/build: Raise the minimum LLVM version to 15.0.0"), so the checks for Clang 14.0.0 and ld.lld 14.0.0 or newer will always been true. Clean them up. Signed-off-by: Nathan Chancellor --- arch/x86/Kconfig | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 58d890fe2100..85b91267c01c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1753,11 +1753,7 @@ config X86_UMIP config CC_HAS_IBT # GCC >=3D 9 and binutils >=3D 2.29 # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cg= i?id=3D93654 - # Clang/LLVM >=3D 14 - # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf3= 1d7f6aac00e0f - # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c664549= 34a37c1f35332 - def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=3Dbranch -mindirect-= branch-register)) || \ - (CC_IS_CLANG && CLANG_VERSION >=3D 140000)) && \ + def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=3Dbranch -mindirect-= branch-register)) || CC_IS_CLANG) && \ $(as-instr,endbr64) =20 config X86_CET @@ -1769,8 +1765,6 @@ config X86_KERNEL_IBT prompt "Indirect Branch Tracking" def_bool y depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL - # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc2= 31f9e579f2d0f - depends on !LD_IS_LLD || LLD_VERSION >=3D 140000 select OBJTOOL select X86_CET help --=20 2.50.1