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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59C4CC63703 for ; Mon, 5 Dec 2022 19:14:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232343AbiLETOS (ORCPT ); Mon, 5 Dec 2022 14:14:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232657AbiLETN5 (ORCPT ); Mon, 5 Dec 2022 14:13:57 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2BF51F2FC for ; Mon, 5 Dec 2022 11:13:56 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 57995CE13A7 for ; Mon, 5 Dec 2022 19:13:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31641C433C1; Mon, 5 Dec 2022 19:13:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670267633; bh=+UbCanSGFmg4aNgaGFPNabzJ/igfMlOd2siXUA34X04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UN+7zET9rsMZOhLcz/CyfzwNNnzVSLn2oT8d50H3aqPg11BcSet5XSf85KouCXJ5a Q/1BpLfY6c3XD38iqFVXRJufHDf2FdhO9QkEsSvvlYyVT9JWZ0OPwBCe+amNOUDYSn Aba80C69uLtIv3wLZ8bU60gUkgHnrj2brTs78/7A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hans de Goede , Pawan Gupta , Borislav Petkov , Dave Hansen , "Rafael J. Wysocki" , stable@kernel.org Subject: [PATCH 4.9 58/62] x86/pm: Add enumeration check before spec MSRs save/restore setup Date: Mon, 5 Dec 2022 20:09:55 +0100 Message-Id: <20221205190800.270829404@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190758.073114639@linuxfoundation.org> References: <20221205190758.073114639@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pawan Gupta commit 50bcceb7724e471d9b591803889df45dcbb584bc upstream. pm_save_spec_msr() keeps a list of all the MSRs which _might_ need to be saved and restored at hibernate and resume. However, it has zero awareness of CPU support for these MSRs. It mostly works by unconditionally attempting to manipulate these MSRs and relying on rdmsrl_safe() being able to handle a #GP on CPUs where the support is unavailable. However, it's possible for reads (RDMSR) to be supported for a given MSR while writes (WRMSR) are not. In this case, msr_build_context() sees a successful read (RDMSR) and marks the MSR as valid. Then, later, a write (WRMSR) fails, producing a nasty (but harmless) error message. This causes restore_processor_state() to try and restore it, but writing this MSR is not allowed on the Intel Atom N2600 leading to: unchecked MSR access error: WRMSR to 0x122 (tried to write 0x0000000000000002) \ at rIP: 0xffffffff8b07a574 (native_write_msr+0x4/0x20) Call Trace: restore_processor_state x86_acpi_suspend_lowlevel acpi_suspend_enter suspend_devices_and_enter pm_suspend.cold state_store kernfs_fop_write_iter vfs_write ksys_write do_syscall_64 ? do_syscall_64 ? up_read ? lock_is_held_type ? asm_exc_page_fault ? lockdep_hardirqs_on entry_SYSCALL_64_after_hwframe To fix this, add the corresponding X86_FEATURE bit for each MSR. Avoid trying to manipulate the MSR when the feature bit is clear. This required adding a X86_FEATURE bit for MSRs that do not have one already, but it's a small price to pay. [ bp: Move struct msr_enumeration inside the only function that uses it. ] [Pawan: Resolve build issue in backport] Fixes: 73924ec4d560 ("x86/pm: Save the MSR validity status at context setup") Reported-by: Hans de Goede Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Reviewed-by: Dave Hansen Acked-by: Rafael J. Wysocki Cc: Link: https://lore.kernel.org/r/c24db75d69df6e66c0465e13676ad3f2837a2ed8.1668539735.git.pawan.kumar.gupta@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/power/cpu.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -520,16 +520,23 @@ static int pm_cpu_check(const struct x86 static void pm_save_spec_msr(void) { - u32 spec_msr_id[] = { - MSR_IA32_SPEC_CTRL, - MSR_IA32_TSX_CTRL, - MSR_TSX_FORCE_ABORT, - MSR_IA32_MCU_OPT_CTRL, - MSR_AMD64_LS_CFG, - MSR_AMD64_DE_CFG, + struct msr_enumeration { + u32 msr_no; + u32 feature; + } msr_enum[] = { + { MSR_IA32_SPEC_CTRL, X86_FEATURE_MSR_SPEC_CTRL }, + { MSR_IA32_TSX_CTRL, X86_FEATURE_MSR_TSX_CTRL }, + { MSR_TSX_FORCE_ABORT, X86_FEATURE_TSX_FORCE_ABORT }, + { MSR_IA32_MCU_OPT_CTRL, X86_FEATURE_SRBDS_CTRL }, + { MSR_AMD64_LS_CFG, X86_FEATURE_LS_CFG_SSBD }, + { MSR_AMD64_DE_CFG, X86_FEATURE_LFENCE_RDTSC }, }; + int i; - msr_build_context(spec_msr_id, ARRAY_SIZE(spec_msr_id)); + for (i = 0; i < ARRAY_SIZE(msr_enum); i++) { + if (boot_cpu_has(msr_enum[i].feature)) + msr_build_context(&msr_enum[i].msr_no, 1); + } } static int pm_check_save_msr(void)