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 63EC5C43334 for ; Tue, 19 Jul 2022 11:58:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237661AbiGSL6I (ORCPT ); Tue, 19 Jul 2022 07:58:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237599AbiGSL51 (ORCPT ); Tue, 19 Jul 2022 07:57:27 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1129C422DD; Tue, 19 Jul 2022 04:56:46 -0700 (PDT) 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 A4D2AB81A8F; Tue, 19 Jul 2022 11:56:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 174AFC341C6; Tue, 19 Jul 2022 11:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658231803; bh=+8CzF90KkgZMMGOcGho4vUISVftHoe5+9nZIO+iktok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cA06JDtfRq+KOlJnq0wZYTSSvAOH6moyXAw84qsqLEzkmtcf/L+A6zWJaTfrT6a3i CArFZV0Ih2Zn1hYU+GW4PUPrfx62g+FxVO7OQZhrm0lA/CJD7O0PYZUMZjEA6+PuFz BcjUhG172UmXmNSvltJwNdAeaRKvnHxKmBBN3q/k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Hunter , Ard Biesheuvel , "Russell King (Oracle)" , Sasha Levin Subject: [PATCH 4.9 08/28] ARM: 9209/1: Spectre-BHB: avoid pr_info() every time a CPU comes out of idle Date: Tue, 19 Jul 2022 13:53:46 +0200 Message-Id: <20220719114457.233333191@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114455.701304968@linuxfoundation.org> References: <20220719114455.701304968@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: Ard Biesheuvel [ Upstream commit 0609e200246bfd3b7516091c491bec4308349055 ] Jon reports that the Spectre-BHB init code is filling up the kernel log with spurious notifications about which mitigation has been enabled, every time any CPU comes out of a low power state. Given that Spectre-BHB mitigations are system wide, only a single mitigation can be enabled, and we already print an error if two types of CPUs coexist in a single system that require different Spectre-BHB mitigations. This means that the pr_info() that describes the selected mitigation does not need to be emitted for each CPU anyway, and so we can simply emit it only once. In order to clarify the above in the log message, update it to describe that the selected mitigation will be enabled on all CPUs, including ones that are unaffected. If another CPU comes up later that is affected and requires a different mitigation, we report an error as before. Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Tested-by: Jon Hunter Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- arch/arm/mm/proc-v7-bugs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c index 35c4660e638a..4af4195eed76 100644 --- a/arch/arm/mm/proc-v7-bugs.c +++ b/arch/arm/mm/proc-v7-bugs.c @@ -217,10 +217,10 @@ static int spectre_bhb_install_workaround(int method) return SPECTRE_VULNERABLE; spectre_bhb_method = method; - } - pr_info("CPU%u: Spectre BHB: using %s workaround\n", - smp_processor_id(), spectre_bhb_method_name(method)); + pr_info("CPU%u: Spectre BHB: enabling %s workaround for all CPUs\n", + smp_processor_id(), spectre_bhb_method_name(method)); + } return SPECTRE_MITIGATED; } -- 2.35.1