From nobody Fri Apr 10 12:34:56 2026 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 A99DEC38145 for ; Tue, 6 Sep 2022 20:20:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231348AbiIFUUi (ORCPT ); Tue, 6 Sep 2022 16:20:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230206AbiIFUT4 (ORCPT ); Tue, 6 Sep 2022 16:19:56 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 904C810C6 for ; Tue, 6 Sep 2022 13:17:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662495469; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=qi5VEGQWfKLp//Fd7xb1fflntdhdcsWG0zpFAAbob8g=; b=jFaiPZ58srM2G7U8EAxcPoMLG91urHtwPjl+buqrvQMpq6TCMtGrrAFo4YrhvfVkqMz461 KcBjRZtfdhTuFSeHYTKhPMVrS48KM0bjEjTufZqUbzCwkO5r3i1UrbEt2ZotWL64QZx7Xg UL/0lBPCjdVvw1cgJIvB6Z+fBC4zhwo= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-505-on3yJhknNt-DnFac5HdN1Q-1; Tue, 06 Sep 2022 16:17:46 -0400 X-MC-Unique: on3yJhknNt-DnFac5HdN1Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C8A353800C2C; Tue, 6 Sep 2022 20:17:45 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id 369472026D4C; Tue, 6 Sep 2022 20:17:44 +0000 (UTC) From: Hans de Goede To: "Rafael J . Wysocki" , Pavel Machek , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" Cc: Hans de Goede , x86@kernel.org, linux-kernel@vger.kernel.org, Dave Hansen Subject: [PATCH] x86/cpu: Avoid writing MSR_IA32_TSX_CTRL when writing it is not supported Date: Tue, 6 Sep 2022 22:17:43 +0200 Message-Id: <20220906201743.436091-1-hdegoede@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On an Intel Atom N2600 (and presumable other Cedar Trail models) MSR_IA32_TSX_CTRL can be read, causing saved_msr.valid to be set for it by msr_build_context(). This causes restore_processor_state() to try and restore it, but writing this MSR is not allowed on the Intel Atom N2600 leading to: [ 99.955141] unchecked MSR access error: WRMSR to 0x122 (tried to write 0= x0000000000000002) at rIP: 0xffffffff8b07a574 (native_write_msr+0x4/0x20) [ 99.955176] Call Trace: [ 99.955186] [ 99.955195] restore_processor_state+0x275/0x2c0 [ 99.955246] x86_acpi_suspend_lowlevel+0x10e/0x140 [ 99.955273] acpi_suspend_enter+0xd3/0x100 [ 99.955297] suspend_devices_and_enter+0x7e2/0x830 [ 99.955341] pm_suspend.cold+0x2d2/0x35e [ 99.955368] state_store+0x68/0xd0 [ 99.955402] kernfs_fop_write_iter+0x15e/0x210 [ 99.955442] vfs_write+0x225/0x4b0 [ 99.955523] ksys_write+0x59/0xd0 [ 99.955557] do_syscall_64+0x58/0x80 [ 99.955579] ? do_syscall_64+0x67/0x80 [ 99.955600] ? up_read+0x17/0x20 [ 99.955631] ? lock_is_held_type+0xe3/0x140 [ 99.955670] ? asm_exc_page_fault+0x22/0x30 [ 99.955688] ? lockdep_hardirqs_on+0x7d/0x100 [ 99.955710] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 99.955723] RIP: 0033:0x7f7d0fb018f7 [ 99.955741] Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f = 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48= > 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 [ 99.955753] RSP: 002b:00007ffd03292ee8 EFLAGS: 00000246 ORIG_RAX: 000000= 0000000001 [ 99.955771] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f7d0fb= 018f7 [ 99.955781] RDX: 0000000000000004 RSI: 00007ffd03292fd0 RDI: 00000000000= 00004 [ 99.955790] RBP: 00007ffd03292fd0 R08: 000000000000c0fe R09: 00000000000= 00000 [ 99.955799] R10: 00007f7d0fb85fb0 R11: 0000000000000246 R12: 00000000000= 00004 [ 99.955808] R13: 000055df564173e0 R14: 0000000000000004 R15: 00007f7d0fb= f49e0 [ 99.955910] Extend the valid check in msr_build_context() to also do a test write of the read value to avoid marking MSR-s which may not be written as valid. Suggested-by: Dave Hansen Signed-off-by: Hans de Goede --- arch/x86/power/cpu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index bb176c72891c..94b41bfd0769 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -433,10 +433,11 @@ static int msr_build_context(const u32 *msr_id, const= int num) } =20 for (i =3D saved_msrs->num, j =3D 0; i < total_num; i++, j++) { - u64 dummy; + u64 value; =20 msr_array[i].info.msr_no =3D msr_id[j]; - msr_array[i].valid =3D !rdmsrl_safe(msr_id[j], &dummy); + msr_array[i].valid =3D !rdmsrl_safe(msr_id[j], &value) && + !wrmsrl_safe(msr_id[j], value); msr_array[i].info.reg.q =3D 0; } saved_msrs->num =3D total_num; --=20 2.37.2