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=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 2EBC2FA372C for ; Fri, 8 Nov 2019 18:54:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0015721D7B for ; Fri, 8 Nov 2019 18:53:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573239240; bh=eMcGqo1LcTNEAmlZhdP4JWX+bzC9XqvUhAIPdPkJq0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Lf3LivBiWqn+bN0MKFK1dK3evIjJcBlg7GU9SJvI4USVHoAKBB2VlbWAw3ZMTb8QY jgKzhIMr+FOtB9V5I/Fsv8HhAlQJ7ElpKacQDQsoCMBLBx14bZx9oGIvqCAdG7WMeF 7qKVGIBdoCT7kem+e0Fg+Wm2ZLtnyHsI+Re4dXCg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732718AbfKHSx7 (ORCPT ); Fri, 8 Nov 2019 13:53:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:50776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732699AbfKHSxz (ORCPT ); Fri, 8 Nov 2019 13:53:55 -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 0063B222CD; Fri, 8 Nov 2019 18:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573239234; bh=eMcGqo1LcTNEAmlZhdP4JWX+bzC9XqvUhAIPdPkJq0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qkZm9i+sYsxBs6Ye8pXpyBVCDF2djBerlnozoWKSlPmS6biNGoUIDADfCaAUDWI3r SbZlyXzaSS/5dy5dRsYS0EkW6KkywiIJEQU7ZUr7TgxZpnBaHnJILSgVHJkaPBCLU9 ihZNlYRiUgqcTtFCALKARWd+mI3gwAWSaVgAaE8w= 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 , Florian Fainelli , Tony Lindgren , "David A. Long" , Ard Biesheuvel Subject: [PATCH 4.4 46/75] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit Date: Fri, 8 Nov 2019 19:50:03 +0100 Message-Id: <20191108174751.327174589@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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Russell King Commit e388b80288aade31135aca23d32eee93dd106795 upstream. When the branch predictor hardening is enabled, firmware must have set the IBE bit in the auxiliary control register. If this bit has not been set, the Spectre workarounds will not be functional. Add validation that this bit is set, and print a warning at alert level if this is not the case. Signed-off-by: Russell King Reviewed-by: Florian Fainelli 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/mm/Makefile | 2 +- arch/arm/mm/proc-v7-bugs.c | 36 ++++++++++++++++++++++++++++++++++++ arch/arm/mm/proc-v7.S | 4 ++-- 3 files changed, 39 insertions(+), 3 deletions(-) --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -92,7 +92,7 @@ obj-$(CONFIG_CPU_MOHAWK) += proc-mohawk. obj-$(CONFIG_CPU_FEROCEON) += proc-feroceon.o obj-$(CONFIG_CPU_V6) += proc-v6.o obj-$(CONFIG_CPU_V6K) += proc-v6.o -obj-$(CONFIG_CPU_V7) += proc-v7.o +obj-$(CONFIG_CPU_V7) += proc-v7.o proc-v7-bugs.o obj-$(CONFIG_CPU_V7M) += proc-v7m.o AFLAGS_proc-v6.o :=-Wa,-march=armv6 --- /dev/null +++ b/arch/arm/mm/proc-v7-bugs.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +static __maybe_unused void cpu_v7_check_auxcr_set(bool *warned, + u32 mask, const char *msg) +{ + u32 aux_cr; + + asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr)); + + if ((aux_cr & mask) != mask) { + if (!*warned) + pr_err("CPU%u: %s", smp_processor_id(), msg); + *warned = true; + } +} + +static DEFINE_PER_CPU(bool, spectre_warned); + +static void check_spectre_auxcr(bool *warned, u32 bit) +{ + if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) && + cpu_v7_check_auxcr_set(warned, bit, + "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n"); +} + +void cpu_v7_ca8_ibe(void) +{ + check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(6)); +} + +void cpu_v7_ca15_ibe(void) +{ + check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(0)); +} --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -511,7 +511,7 @@ __v7_setup_stack: globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend globl_equ cpu_ca8_do_resume, cpu_v7_do_resume #endif - define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 + define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca8_ibe @ Cortex-A9 - needs more registers preserved across suspend/resume @ and bpiall switch_mm for hardening @@ -544,7 +544,7 @@ __v7_setup_stack: globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend globl_equ cpu_ca15_do_resume, cpu_v7_do_resume - define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 + define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca15_ibe #ifdef CONFIG_CPU_PJ4B define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 #endif