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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 E13DFC433E0 for ; Tue, 26 May 2020 19:15:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8D53208A7 for ; Tue, 26 May 2020 19:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520518; bh=zcyVS/NHVYgcarFW3W2ZpzEq8bYzC9EzovUz+I2DAyw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nj0Xeo0wP/ZP8zK0PCvkg6vTMNAwcKT7cp6dXOSXCnUkqj7vEBosaDAvvif58JdHB bjkLRjUgmfbLOt5BR8d6rWV5PODWTfEqRfYxiM/bWyfOBzTQCO1GP0np1Vlwzgceiv 0/V9IV81vUCGGh3+n9z+1uuSyPJ0LwL20adTTbZc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404187AbgEZTPL (ORCPT ); Tue, 26 May 2020 15:15:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:46672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404196AbgEZTPL (ORCPT ); Tue, 26 May 2020 15:15:11 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 30ABD208B3; Tue, 26 May 2020 19:15:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520510; bh=zcyVS/NHVYgcarFW3W2ZpzEq8bYzC9EzovUz+I2DAyw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TSZIA+gafZ33oeMDnYNIekdQHiYkWZG/SE0R7XCNo3GlJ/QDi/iA4nPtDekMB+9Is qyyn78euZ7YRNsAppnPncBtHYvTs4H0ky3SKiklh163mg5bGE9GnlRyo/MYY1Zxz+l NigwDByTjIokYRv+7V30awp/DLnjCe4zfUU300Ww= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman Subject: [PATCH 5.6 071/126] powerpc/64s: Disable STRICT_KERNEL_RWX Date: Tue, 26 May 2020 20:53:28 +0200 Message-Id: <20200526183944.154484688@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183937.471379031@linuxfoundation.org> References: <20200526183937.471379031@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Ellerman commit 8659a0e0efdd975c73355dbc033f79ba3b31e82c upstream. Several strange crashes have been eventually traced back to STRICT_KERNEL_RWX and its interaction with code patching. Various paths in our ftrace, kprobes and other patching code need to be hardened against patching failures, otherwise we can end up running with partially/incorrectly patched ftrace paths, kprobes or jump labels, which can then cause strange crashes. Although fixes for those are in development, they're not -rc material. There also seem to be problems with the underlying strict RWX logic, which needs further debugging. So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from enabling the option and tripping over the bugs. Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -129,7 +129,7 @@ config PPC select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_MEMBARRIER_CALLBACKS select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64 - select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !HIBERNATION) + select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION) select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UACCESS_FLUSHCACHE select ARCH_HAS_UACCESS_MCSAFE if PPC64