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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 98C8FECDFBB for ; Fri, 20 Jul 2018 12:42:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D7D620652 for ; Fri, 20 Jul 2018 12:42:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D7D620652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390085AbeGTNa7 (ORCPT ); Fri, 20 Jul 2018 09:30:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53182 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389343AbeGTNa6 (ORCPT ); Fri, 20 Jul 2018 09:30:58 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 93E9BCF3; Fri, 20 Jul 2018 12:39:46 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Will Deacon , Mark Rutland , Marc Zyngier , Catalin Marinas Subject: [PATCH 4.17 092/101] arm64: ssbd: Restore mitigation status on CPU resume Date: Fri, 20 Jul 2018 14:14:38 +0200 Message-Id: <20180720121427.132568465@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720121422.837870592@linuxfoundation.org> References: <20180720121422.837870592@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit 647d0519b53f440a55df163de21c52a8205431cc upstream. On a system where firmware can dynamically change the state of the mitigation, the CPU will always come up with the mitigation enabled, including when coming back from suspend. If the user has requested "no mitigation" via a command line option, let's enforce it by calling into the firmware again to disable it. Similarily, for a resume from hibernate, the mitigation could have been disabled by the boot kernel. Let's ensure that it is set back on in that case. Acked-by: Will Deacon Reviewed-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/kernel/cpu_errata.c | 2 +- arch/arm64/kernel/hibernate.c | 11 +++++++++++ arch/arm64/kernel/suspend.c | 8 ++++++++ 4 files changed, 26 insertions(+), 1 deletion(-) --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -553,6 +553,12 @@ static inline int arm64_get_ssbd_state(v #endif } +#ifdef CONFIG_ARM64_SSBD +void arm64_set_ssbd_mitigation(bool state); +#else +static inline void arm64_set_ssbd_mitigation(bool state) {} +#endif + #endif /* __ASSEMBLY__ */ #endif --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -303,7 +303,7 @@ void __init arm64_enable_wa2_handling(st *updptr = cpu_to_le32(aarch64_insn_gen_nop()); } -static void arm64_set_ssbd_mitigation(bool state) +void arm64_set_ssbd_mitigation(bool state) { switch (psci_ops.conduit) { case PSCI_CONDUIT_HVC: --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -313,6 +313,17 @@ int swsusp_arch_suspend(void) sleep_cpu = -EINVAL; __cpu_suspend_exit(); + + /* + * Just in case the boot kernel did turn the SSBD + * mitigation off behind our back, let's set the state + * to what we expect it to be. + */ + switch (arm64_get_ssbd_state()) { + case ARM64_SSBD_FORCE_ENABLE: + case ARM64_SSBD_KERNEL: + arm64_set_ssbd_mitigation(true); + } } local_daif_restore(flags); --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -62,6 +62,14 @@ void notrace __cpu_suspend_exit(void) */ if (hw_breakpoint_restore) hw_breakpoint_restore(cpu); + + /* + * On resume, firmware implementing dynamic mitigation will + * have turned the mitigation on. If the user has forcefully + * disabled it, make sure their wishes are obeyed. + */ + if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) + arm64_set_ssbd_mitigation(false); } /*