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 A5F64C433FE for ; Mon, 24 Jan 2022 22:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1841069AbiAXW5b (ORCPT ); Mon, 24 Jan 2022 17:57:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1577000AbiAXV5F (ORCPT ); Mon, 24 Jan 2022 16:57:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14005C09426C; Mon, 24 Jan 2022 12:38:38 -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 ams.source.kernel.org (Postfix) with ESMTPS id CF3E9B81218; Mon, 24 Jan 2022 20:38:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C0C0C340E5; Mon, 24 Jan 2022 20:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643056715; bh=sUaXfDJ9Sn5dKwepOQtj6siD2em1urOqxKMAIkUatHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K5P6qHCm77e5PcSVKe91pZRDTsIVk1UX3rIUlQSaMGrY+Vzqg9s2plJZmyHGlphMt F5lm8GaLzXoJGJARlLPyYY+qZ5M5Qfua2uTnr316Pdr/XCkBxNNxRc8u2nZ0WcsyJV Me0DHZvmTFyBRC6CkCTe+ajNPFmVYN9lVg40C7c4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Borislav Petkov , Sasha Levin Subject: [PATCH 5.15 543/846] x86/mce: Mark mce_panic() noinstr Date: Mon, 24 Jan 2022 19:41:00 +0100 Message-Id: <20220124184119.759494910@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov [ Upstream commit 3c7ce80a818fa7950be123cac80cd078e5ac1013 ] 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 Link: https://lore.kernel.org/r/20211208111343.8130-8-bp@alien8.de Signed-off-by: Sasha Levin --- 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 c8d121085c8f7..c5a1022463bcc 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -295,11 +295,17 @@ 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) { /* @@ -314,7 +320,7 @@ 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 */ @@ -352,6 +358,9 @@ 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 */ -- 2.34.1