From nobody Thu Jan 8 17:48:37 2026 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 C658EE748F5 for ; Sun, 1 Oct 2023 13:16:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235006AbjJANQt (ORCPT ); Sun, 1 Oct 2023 09:16:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234984AbjJANQm (ORCPT ); Sun, 1 Oct 2023 09:16:42 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA6DFBA for ; Sun, 1 Oct 2023 06:16:38 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id a640c23a62f3a-9a9f139cd94so2053738866b.2 for ; Sun, 01 Oct 2023 06:16:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696166197; x=1696770997; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=GJ0tDwQlRD6Ds2+VaCyIxp6VxUBqGS+A19FnDIU/GbU=; b=i2u356GhIprffm6YXVr6jVWf8UFEOvllXrTckigMg2VwOjqbjJgxATnqTQlCbiJ43k 0Gi36VnVce1JPbccduU/eSnU777IkWpGksaVvvV2qrx1GcvFPtB/wS1bNO6n4e5o0fbT 1bXvCpyxcQIJhYW/qH0ex2WkSBfHxhU8M0V5F8TpbfQ7aQ8GuouCCLs1xsmp9PorYAHi RYIoYDZ53fNr1fF4F9j5xoqSKNZl9OTqZXxeKycJX8tw1lP2umYwrJfmaJ9ca/uTIx03 qeOo4h7IC1rA/Bj/sIg8peXIumL04uQyPdvpWM/ZBtJGMPFGf7qMSmD+LpXIL1QwcqRj hxQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696166197; x=1696770997; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=GJ0tDwQlRD6Ds2+VaCyIxp6VxUBqGS+A19FnDIU/GbU=; b=TkV6bsdP50/uVp5o+1VDiTeqAw/b3CXiae5Z6AJRfde0eX/46nqwHhoR3FnoBJ/OMo A6W1yPjSG/EEnfyZauEmAG2P3x320ALUBx/4EZXSs7jkYSQoEnblMm+FeIcIHrzYOBCY 57OulQJWSugm3oC/7XvwiNk2OhF01HtLdG1AkrDM8KrzSaVH0mQCDB5hqbZV/r1cwuVv Da985bCRf0O1Z6bG8ujy5jvfIQa871NIYfq/Va/bbX6AFzsGMQXOb8R01H8HCctO+X5U qaBfzO6YR43NrCwpm9iT1E9bZ/x7Fndlf8mNENBU1JK2b0IwRjgs9fVpZMqm7/W3lOdj BU/w== X-Gm-Message-State: AOJu0YyoPBSBh1UuuL1Ij9D+TdX38Ec8UymlQ8AJ1Av70D3sNJ992adD ku+/nnFTtAr8GZuGPkp9f5k= X-Google-Smtp-Source: AGHT+IH+iG2cmTsm7yj58wvz1hW5RV3lsVS1dxDNFVwQS+dO+T7ENDzoRDzdClCgFS6guYkEuEAWSg== X-Received: by 2002:a17:906:210a:b0:9b2:b149:b818 with SMTP id 10-20020a170906210a00b009b2b149b818mr8574770ejt.70.1696166197218; Sun, 01 Oct 2023 06:16:37 -0700 (PDT) Received: from localhost.localdomain ([46.248.82.114]) by smtp.gmail.com with ESMTPSA id lv23-20020a170906bc9700b0099d798a6bb5sm15504272ejb.67.2023.10.01.06.16.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Oct 2023 06:16:36 -0700 (PDT) From: Uros Bizjak To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Uros Bizjak , Andy Lutomirski , Ingo Molnar , Nadav Amit , Brian Gerst , Denys Vlasenko , "H . Peter Anvin" , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Borislav Petkov , Josh Poimboeuf Subject: [RFC PATCH 2/4] x86/percpu: Detect compiler support for named address spaces Date: Sun, 1 Oct 2023 15:14:34 +0200 Message-ID: <20231001131620.112484-3-ubizjak@gmail.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231001131620.112484-1-ubizjak@gmail.com> References: <20231001131620.112484-1-ubizjak@gmail.com> 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" Detect compiler support for named address spaces by trying to compile a small testcase that includes __seg_gs and __seg_gs keywords. Reflect successful compilation in CC_HAS_NAMED_AS and set USE_X86_SEG_SUPPORT to signal when segment qualifiers should be used. Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Nadav Amit Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Borislav Petkov Cc: Josh Poimboeuf Signed-off-by: Uros Bizjak --- arch/x86/Kconfig | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 66bfabae8814..f66fa5bf1f78 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2388,6 +2388,13 @@ source "kernel/livepatch/Kconfig" =20 endmenu =20 +config CC_HAS_NAMED_AS + def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c = - -c -o /dev/null) + +config USE_X86_SEG_SUPPORT + def_bool y + depends on CC_HAS_NAMED_AS && SMP + config CC_HAS_SLS def_bool $(cc-option,-mharden-sls=3Dall) =20 --=20 2.41.0