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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 51B57C433E2 for ; Tue, 15 Sep 2020 19:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D63A6206DB for ; Tue, 15 Sep 2020 19:41:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="ogFTvH9u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727631AbgIOTlV (ORCPT ); Tue, 15 Sep 2020 15:41:21 -0400 Received: from mail.skyhub.de ([5.9.137.197]:36896 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726485AbgIOTkg (ORCPT ); Tue, 15 Sep 2020 15:40:36 -0400 Received: from zn.tnic (p200300ec2f0e42009474dca2b756bdd4.dip0.t-ipconnect.de [IPv6:2003:ec:2f0e:4200:9474:dca2:b756:bdd4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 892F11EC01A8; Tue, 15 Sep 2020 21:40:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1600198831; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=65Fmx3+2+A5MgCyvYFK8ocEVfRnMH/n6i5Pxc2W9nec=; b=ogFTvH9uOhZIaeK6T7Iw2D7NjTIMr4bgoD0+nx3KsLzUE8SC1MRqcj2Wn8KD7HRfJxsbgj hpPpXqma8qJATsWNv8opgyTfsEVK+pXKr5YSylOHUSAnu5UdynZfQA0dr88MLQMiJ73PgI JgI7MApj05pQnnlvPj5ItQ6AL8iWc5I= From: Borislav Petkov To: Tony Luck Cc: X86 ML , LKML Subject: [PATCH] x86/mce: Annotate mce_rd/wrmsrl() with noinstr Date: Tue, 15 Sep 2020 21:40:20 +0200 Message-Id: <20200915194020.28807-1-bp@alien8.de> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov They do get called from the #MC handler which is already marked "noinstr". Commit e2def7d49d08 ("x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR") already got rid of the instrumentation in the MSR accessors, fix the annotation now too, in order to get rid of: vmlinux.o: warning: objtool: do_machine_check()+0x4a: call to mce_rdmsrl() leaves .noinstr.text section Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/mce/core.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index a697baee9aa0..1ed14f67d13f 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -392,16 +392,25 @@ __visible bool ex_handler_rdmsr_fault(const struct exception_table_entry *fixup, } /* MSR access wrappers used for error injection */ -static u64 mce_rdmsrl(u32 msr) +static noinstr u64 mce_rdmsrl(u32 msr) { DECLARE_ARGS(val, low, high); if (__this_cpu_read(injectm.finished)) { - int offset = msr_to_offset(msr); + int offset; + u64 ret; + instrumentation_begin(); + + offset = msr_to_offset(msr); if (offset < 0) - return 0; - return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); + ret = 0; + else + ret = *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); + + instrumentation_end(); + + return ret; } /* @@ -437,15 +446,21 @@ __visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup, return true; } -static void mce_wrmsrl(u32 msr, u64 v) +static noinstr void mce_wrmsrl(u32 msr, u64 v) { u32 low, high; if (__this_cpu_read(injectm.finished)) { - int offset = msr_to_offset(msr); + int offset; + instrumentation_begin(); + + offset = msr_to_offset(msr); if (offset >= 0) *(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v; + + instrumentation_end(); + return; } -- 2.21.0