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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 29BAEC5DF60 for ; Fri, 8 Nov 2019 12:36:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00241224ED for ; Fri, 8 Nov 2019 12:36:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573216618; bh=0QjqhVsp76t9caeWGd64aTloHA72cawsl8X7RJI3Mjw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zeQuc9KweiA5XAYZtvws9e8baoN7eLavx1OtZvEO4dQSvSOqPHw7pldJSOo0blfR0 k6Ng5w4vZhfXOP6/SqqkEzhY2INKwNti6xEZ9s10R6MJzLKYBMilO/iYC3ueH5ZmPp 71qvkLdSwIvU71ytngJUY/6DU0HUw/+l8wZPTasY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727041AbfKHMg5 (ORCPT ); Fri, 8 Nov 2019 07:36:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:44510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726036AbfKHMg5 (ORCPT ); Fri, 8 Nov 2019 07:36:57 -0500 Received: from localhost.localdomain (lfbn-mar-1-550-151.w90-118.abo.wanadoo.fr [90.118.131.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D82E8224D5; Fri, 8 Nov 2019 12:36:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573216616; bh=0QjqhVsp76t9caeWGd64aTloHA72cawsl8X7RJI3Mjw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ep5n3/xy7oLti/QQ0Z1a2HgQbw6f6ySmZy7ghaaDUgku507xlvGTb4owQA2lk7aGx 2xppmkJTUfBmf/WdUersrLeMqWzQfgDpPHnH07+R7IKEPkYKooRNMZ1fRSIl9eaWhz wFFjl8zDkUi+G38jhtqIhqw4bnQ40rHlzXqfsqVY= From: Ard Biesheuvel To: stable@vger.kernel.org Cc: linus.walleij@linaro.org, rmk+kernel@armlinux.org.uk, Ard Biesheuvel Subject: [PATCH for-stable-4.4 28/50] ARM: spectre-v1: add array_index_mask_nospec() implementation Date: Fri, 8 Nov 2019 13:35:32 +0100 Message-Id: <20191108123554.29004-29-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108123554.29004-1-ardb@kernel.org> References: <20191108123554.29004-1-ardb@kernel.org> MIME-Version: 1.0 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 --- arch/arm/include/asm/barrier.h | 21 ++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h index edd9e633a84b..8514b70704de 100644 --- 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 */ -- 2.20.1