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 9FE49C433EF for ; Mon, 20 Dec 2021 15:13:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239730AbhLTPNW (ORCPT ); Mon, 20 Dec 2021 10:13:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238491AbhLTPLR (ORCPT ); Mon, 20 Dec 2021 10:11:17 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D1CDC08EB32; Mon, 20 Dec 2021 06:56:28 -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 dfw.source.kernel.org (Postfix) with ESMTPS id BF294611BB; Mon, 20 Dec 2021 14:56:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A025BC36AE7; Mon, 20 Dec 2021 14:56:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640012187; bh=1+ZTRF3+8NGjaT7/hkS3eY+fxbWr4+MMtKRkyA50sUY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oTtvx9phcZ+NEswbyN1HCsoEmeSRCYrdpEqg4T2dOEQAd3hpABc3zdOxleAkuLQjz 7o3Tto0hqEB4af+f16NRFyfCDTwJAfDXGG68etpRijkeuG31hgEgEWN2FACYorlT2d 4AS4TJu4PbKNUxuDUUxRhmLrMqmJzM5FxwQ9V9PU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Kennedy , Xiaoming Ni , Michael Ellerman , Sasha Levin Subject: [PATCH 5.15 112/177] powerpc/85xx: Fix oops when CONFIG_FSL_PMC=n Date: Mon, 20 Dec 2021 15:34:22 +0100 Message-Id: <20211220143043.844382794@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211220143040.058287525@linuxfoundation.org> References: <20211220143040.058287525@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: Xiaoming Ni [ Upstream commit 3dc709e518b47386e6af937eaec37bb36539edfd ] When CONFIG_FSL_PMC is set to n, no value is assigned to cpu_up_prepare in the mpc85xx_pm_ops structure. As a result, oops is triggered in smp_85xx_start_cpu(). smp: Bringing up secondary CPUs ... kernel tried to execute user page (0) - exploit attempt? (uid: 0) BUG: Unable to handle kernel instruction fetch (NULL pointer?) Faulting instruction address: 0x00000000 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [00000000] 0x0 LR [c0021d2c] smp_85xx_kick_cpu+0xe8/0x568 Call Trace: [c1051da8] [c0021cb8] smp_85xx_kick_cpu+0x74/0x568 (unreliable) [c1051de8] [c0011460] __cpu_up+0xc0/0x228 [c1051e18] [c0031bbc] bringup_cpu+0x30/0x224 [c1051e48] [c0031f3c] cpu_up.constprop.0+0x180/0x33c [c1051e88] [c00322e8] bringup_nonboot_cpus+0x88/0xc8 [c1051eb8] [c07e67bc] smp_init+0x30/0x78 [c1051ed8] [c07d9e28] kernel_init_freeable+0x118/0x2a8 [c1051f18] [c00032d8] kernel_init+0x14/0x124 [c1051f38] [c0010278] ret_from_kernel_thread+0x14/0x1c Fixes: c45361abb918 ("powerpc/85xx: fix timebase sync issue when CONFIG_HOTPLUG_CPU=n") Reported-by: Martin Kennedy Signed-off-by: Xiaoming Ni Tested-by: Martin Kennedy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211126041153.16926-1-nixiaoming@huawei.com Signed-off-by: Sasha Levin --- arch/powerpc/platforms/85xx/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index 83f4a6389a282..d7081e9af65c7 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -220,7 +220,7 @@ static int smp_85xx_start_cpu(int cpu) local_irq_save(flags); hard_irq_disable(); - if (qoriq_pm_ops) + if (qoriq_pm_ops && qoriq_pm_ops->cpu_up_prepare) qoriq_pm_ops->cpu_up_prepare(cpu); /* if cpu is not spinning, reset it */ @@ -292,7 +292,7 @@ static int smp_85xx_kick_cpu(int nr) booting_thread_hwid = cpu_thread_in_core(nr); primary = cpu_first_thread_sibling(nr); - if (qoriq_pm_ops) + if (qoriq_pm_ops && qoriq_pm_ops->cpu_up_prepare) qoriq_pm_ops->cpu_up_prepare(nr); /* -- 2.34.1