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 9526BC433FE for ; Wed, 8 Dec 2021 11:14:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232398AbhLHLRl (ORCPT ); Wed, 8 Dec 2021 06:17:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232223AbhLHLRW (ORCPT ); Wed, 8 Dec 2021 06:17:22 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E406C0617A2 for ; Wed, 8 Dec 2021 03:13:51 -0800 (PST) Received: from zn.tnic (dslb-088-067-202-008.088.067.pools.vodafone-ip.de [88.67.202.8]) (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 C617E1EC04EC; Wed, 8 Dec 2021 12:13:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1638962029; 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:in-reply-to:references:references; bh=X6DeNY6NraKICDhBYcBMTtNl1trS2fkoTwQ7CfXs3HE=; b=JA9UmlLq1oTvRvi/LdTNu35NaQb31y8LlOwMpBdwb8oGXBq6l/EKGxJHOjjZNOELRh7HP3 EdDTEC8tWGFqD7ylCR7nAG68ez7XO7TVFASoZ7HzYy8wijReicZL8C8jusYrdu6nzoOF7B dNNbeem6YgISoNVvT48CDeANzYoIUKs= From: Borislav Petkov To: Tony Luck Cc: X86 ML , LKML Subject: [PATCH v1 07/12] x86/mce: Mark mce_panic() noinstr Date: Wed, 8 Dec 2021 12:13:38 +0100 Message-Id: <20211208111343.8130-8-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211208111343.8130-1-bp@alien8.de> References: <20211208111343.8130-1-bp@alien8.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov And allow instrumentation inside it because it does calls to other facilities which will not be tagged noinstr. Fixes vmlinux.o: warning: objtool: do_machine_check()+0xc73: call to mce_panic() leaves .noinstr.text section Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/mce/core.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index d7fa444d6282..d81266885de3 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -266,11 +266,17 @@ static void wait_for_panic(void) panic("Panicing machine check CPU died"); } -static void mce_panic(const char *msg, struct mce *final, char *exp) +static noinstr void mce_panic(const char *msg, struct mce *final, char *exp) { - int apei_err = 0; struct llist_node *pending; struct mce_evt_llist *l; + int apei_err = 0; + + /* + * Allow instrumentation around external facilities usage. Not that it + * matters a whole lot since the machine is going to panic anyway. + */ + instrumentation_begin(); if (!fake_panic) { /* @@ -285,7 +291,7 @@ static void mce_panic(const char *msg, struct mce *final, char *exp) } else { /* Don't log too much for fake panic */ if (atomic_inc_return(&mce_fake_panicked) > 1) - return; + goto out; } pending = mce_gen_pool_prepare_records(); /* First print corrected ones that are still unlogged */ @@ -321,6 +327,9 @@ static void mce_panic(const char *msg, struct mce *final, char *exp) panic(msg); } else pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg); + +out: + instrumentation_end(); } /* Support code for software error injection */ -- 2.29.2