From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39BDBC5DF60 for ; Fri, 8 Nov 2019 19:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 135862067B for ; Fri, 8 Nov 2019 19:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573241019; bh=SiRX2WcJEqeeFkGkg/ORrfHEGEouVfa+skK4XZUnyiw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hafuX4AYUqEwzzwfVop0QcimP+mBKOsNNtlN/ur1rK9CvB43mR6F2oHzL8zBMKdeM 2wumOz1L0euEjjAqtYeWMV1JkTZvYinpjXxqAg1XQkJAx1DKgyovdMd06jBF0IQIPv 9DQbk5KK3aOp3sxmR1V2w/QKPZNqFqxOibL7sasQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388666AbfKHTXe (ORCPT ); Fri, 8 Nov 2019 14:23:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:51130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732884AbfKHSyT (ORCPT ); Fri, 8 Nov 2019 13:54:19 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C61C42178F; Fri, 8 Nov 2019 18:54:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573239249; bh=SiRX2WcJEqeeFkGkg/ORrfHEGEouVfa+skK4XZUnyiw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=y5nalBcmpyZwlIK7cnwrxXVUfv5z0vNrvQHN4gragwF/ZVpgRfQiXO+GD/srdizzT Sh7N08G/EExB+N4EQUj0gQ6CKBJxTANoQITvF1/uHaVyDk3yC1TFMyfrzERUdfpU9V OzVHP11cYjx9drEbM+CiCAiqvsRCUuT7mQRbJoN8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , "linus.walleij@linaro.org, rmk+kernel@armlinux.org.uk, Ard Biesheuvel" , Russell King , Mark Rutland , Tony Lindgren , "David A. Long" , Ard Biesheuvel Subject: [PATCH 4.4 51/75] ARM: spectre-v1: add array_index_mask_nospec() implementation Date: Fri, 8 Nov 2019 19:50:08 +0100 Message-Id: <20191108174754.520254735@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191108174708.135680837@linuxfoundation.org> References: <20191108174708.135680837@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Russell King Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream. Add an implementation of the array_index_mask_nospec() function for mitigating Spectre variant 1 throughout the kernel. Signed-off-by: Russell King Acked-by: Mark Rutland Boot-tested-by: Tony Lindgren Reviewed-by: Tony Lindgren Signed-off-by: David A. Long Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/barrier.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -108,5 +108,26 @@ do { \ #define smp_mb__before_atomic() smp_mb() #define smp_mb__after_atomic() smp_mb() +#ifdef CONFIG_CPU_SPECTRE +static inline unsigned long array_index_mask_nospec(unsigned long idx, + unsigned long sz) +{ + unsigned long mask; + + asm volatile( + "cmp %1, %2\n" + " sbc %0, %1, %1\n" + CSDB + : "=r" (mask) + : "r" (idx), "Ir" (sz) + : "cc"); + + return mask; +} +#define array_index_mask_nospec array_index_mask_nospec +#endif + +#include + #endif /* !__ASSEMBLY__ */ #endif /* __ASM_BARRIER_H */