From nobody Tue Apr 7 12:46:19 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 5B5E9C4332F for ; Mon, 17 Oct 2022 13:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230031AbiJQNrq (ORCPT ); Mon, 17 Oct 2022 09:47:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229968AbiJQNrg (ORCPT ); Mon, 17 Oct 2022 09:47:36 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4434852FD9; Mon, 17 Oct 2022 06:47:34 -0700 (PDT) Date: Mon, 17 Oct 2022 13:47:31 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666014452; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3GpTfY3y5qdlAiQiJDXMLWXE9wY2GvyezsXxcK3s5I=; b=wMmHLSJetIHsJ8irzObZ3AgopznAlw8RAl/kmGgfAaLQVi8gWDiYtxDUT1ab0YoXgTNqSb cUZ1lGjcYGMc4i1sEFZZLhD6cEMe++P0wk8DZk7DAbKC5kOujybscK3yMHsmmNo7trc5Su WwbdMhv9zx6ii4FA8yAm7PEzEFgOhwtrxig7Dk1yUKjNjKOhsmIbfz6YhXaIKm6bxI19rn /ui63Booxm3I0aiq45eEOqMr0Xzcwo6JXRSL62fLAHOqt+6ytx1TSq3ziWkcHqw+S2YoFe xZ91Eo1O+cOy58Dm6CLNfYrDb2aoT9WwkvGWQSCfqdkBS8DtZ/0dcyI2UkTAgA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666014452; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3GpTfY3y5qdlAiQiJDXMLWXE9wY2GvyezsXxcK3s5I=; b=ScmnGY8OVfjvKVhOlrpxTCfnLRU6HF8vrFQpvKmQYT0e8Rs7YpyeBC/tEpChttj13TYde3 lMCD2CPSWaTjBxCw== From: "tip-bot2 for Chang S. Bae" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/urgent] x86/fpu: Fix the init_fpstate size check with the actual size Cc: "Chang S. Bae" , Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220824191223.1248-3-chang.seok.bae@intel.com> References: <20220824191223.1248-3-chang.seok.bae@intel.com> MIME-Version: 1.0 Message-ID: <166601445140.401.5905202379513336433.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/urgent branch of tip: Commit-ID: d3e021adac7c51a26d9ede167c789fcc1b878467 Gitweb: https://git.kernel.org/tip/d3e021adac7c51a26d9ede167c789fcc1= b878467 Author: Chang S. Bae AuthorDate: Wed, 24 Aug 2022 12:12:22 -07:00 Committer: Thomas Gleixner CommitterDate: Mon, 17 Oct 2022 15:44:25 +02:00 x86/fpu: Fix the init_fpstate size check with the actual size The init_fpstate buffer is statically allocated. Thus, the sanity test was established to check whether the pre-allocated buffer is enough for the calculated size or not. The currently measured size is not strictly relevant. Fix to validate the calculated init_fpstate size with the pre-allocated area. Also, replace the sanity check function with open code for clarity. The abstraction itself and the function naming do not tend to represent simply what it does. Fixes: 2ae996e0c1a3 ("x86/fpu: Calculate the default sizes independently") Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20220824191223.1248-3-chang.seok.bae@intel.= com --- arch/x86/kernel/fpu/xstate.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index f0ce106..f5ef786 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -678,20 +678,6 @@ static unsigned int __init get_xsave_size_user(void) return ebx; } =20 -/* - * Will the runtime-enumerated 'xstate_size' fit in the init - * task's statically-allocated buffer? - */ -static bool __init is_supported_xstate_size(unsigned int test_xstate_size) -{ - if (test_xstate_size <=3D sizeof(init_fpstate.regs)) - return true; - - pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n", - sizeof(init_fpstate.regs), test_xstate_size); - return false; -} - static int __init init_xstate_size(void) { /* Recompute the context size for enabled features: */ @@ -717,10 +703,6 @@ static int __init init_xstate_size(void) kernel_default_size =3D xstate_calculate_size(fpu_kernel_cfg.default_features, compacted); =20 - /* Ensure we have the space to store all default enabled features. */ - if (!is_supported_xstate_size(kernel_default_size)) - return -EINVAL; - if (!paranoid_xstate_size_valid(kernel_size)) return -EINVAL; =20 @@ -879,6 +861,12 @@ void __init fpu__init_system_xstate(unsigned int legac= y_size) init_fpstate.size =3D fpu_kernel_cfg.max_size; init_fpstate.xfeatures =3D fpu_kernel_cfg.max_features; =20 + if (init_fpstate.size > sizeof(init_fpstate.regs)) { + pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d), disabling XS= AVE\n", + sizeof(init_fpstate.regs), init_fpstate.size); + goto out_disable; + } + setup_init_fpu_buf(); =20 /*