From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-xb2d.google.com (mail-yb1-xb2d.google.com [IPv6:2607:f8b0:4864:20::b2d]) by sourceware.org (Postfix) with ESMTPS id A737F385800A for ; Thu, 16 Mar 2023 00:43:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A737F385800A Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-yb1-xb2d.google.com with SMTP id z83so137793ybb.2 for ; Wed, 15 Mar 2023 17:43:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678927396; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=iilAxynILQs4dm8ncmEPmTeKdxXxe2ELIQvgDSeX17w=; b=esudAxbeXuqs3BQ6F8qzCCTMtq/eZBMh0cBdl2jhjXH6DfXUiw+xDnh4JA1yxFz8P4 xq0DhqIP0YGhA/+WiurYl6eQ8mAnzhH2e9OBhrkL+ahj/HXqlV1UqaYtlCRvM40Pysz/ +wpBC/wViJPqSngh8YxfRZBdF5FKIPws/5eSsIuMgrNJtpceA9BE1DVHYuIP+NQO28Im Q0eY8sj9JmQDTumOhD9U9clCLaYpWqc0JDIyb8/ajxOPm83kAzST24wYoN46SU1SBf9Z dphOH/tAK/nxCeDLC9YjKxkHv45chtU9NcMcv22i5OgJN3nXLnaV4ygGKf0vJu/ng3uo Kqmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678927396; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iilAxynILQs4dm8ncmEPmTeKdxXxe2ELIQvgDSeX17w=; b=a+in68y3neZMTozPr9UlMurWDETCcvRA9XEncpHBVHwHOzUvBTcreOt8k1QfOg4bjI 14AEZ4Hrkz0uDNcjnTiEDpskOedT8JHVd7IQXkpqS9ESdhtuAyCm0uUxeoSRze/tofxu NNIc71a7CpQwHCwp/r+jPi2tYcBABQ0zxKTDTRBcQlfX2I8NE37IDLf8hIh7oaIILocY 3vxozDbnxrpumwuOsxeUaTQCg2r08wUwwng+ozjvGJkSI5kRdmRI49jS5JY7o5G0kS+v 3G327TUk0QY6hENPHf2oTIy7Rb8RkQmF+pmpVBiT147gSe0LAWQ1dNMROKdc4vXIJ8WJ B3aw== X-Gm-Message-State: AO0yUKXB3ZcT3N/hsIbZNW82A2PFJ02AQUloi7FseLFivhrUAnQ9VpvW pxgGz8Ckp94bn3fo0QilH9pTwZ6JvMz5voiLPLE= X-Google-Smtp-Source: AK7set9uZAAgq379nVT90F1KuB9/ann8polIYI596D25y6K7XDsk+PXQgYaCFD+t+fI3RDYkL0vA9boljdzgjmeEMdo= X-Received: by 2002:a25:9292:0:b0:b3a:e877:3290 with SMTP id y18-20020a259292000000b00b3ae8773290mr8561239ybl.2.1678927396063; Wed, 15 Mar 2023 17:43:16 -0700 (PDT) MIME-Version: 1.0 References: <20230309182603.205394-1-hjl.tools@gmail.com> <87zg8grcjf.fsf@oldenburg.str.redhat.com> In-Reply-To: <87zg8grcjf.fsf@oldenburg.str.redhat.com> From: "H.J. Lu" Date: Wed, 15 Mar 2023 17:42:40 -0700 Message-ID: Subject: Re: [PATCH] x86: Set FSGSBASE to active if enabled by kernel To: Florian Weimer Cc: libc-alpha@sourceware.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-3016.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Mon, Mar 13, 2023 at 6:44=E2=80=AFAM Florian Weimer = wrote: > > * H. J. Lu: > > > Linux kernel uses AT_HWCAP2 to indicate if FSGSBASE instructions are > > enabled. If the HWCAP2_FSGSBASE bit in AT_HWCAP2 is set, FSGSBASE > > instructions can be used in user space. Define dl_check_hwcap2 to set > > the FSGSBASE feature to active on Linux when the HWCAP2_FSGSBASE bit is > > set. > > Could you add a test against /proc/cpuinfo flags? It should be a > perfect match on current kernels. > Will do. Thanks. --=20 H.J.