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=-13.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 46CC0C433DF for ; Mon, 24 Aug 2020 08:48:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A9AF204FD for ; Mon, 24 Aug 2020 08:48:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258922; bh=JWJlvUsK6gkl2cRksfkM0gxOVpkwCKdmM0aaXQwlZik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Cec2MkNri+FMmD6xE3md/LdeX+jmruRwtWH1JD/0kAEdD4spnpQrtUWZVkPTq0oRF 7mf6XVkwH0mf31gvzbEQuhz+kEiAdWdf8Hf6bGQLmlp79ZPdFiBoHfJC/Dw61gJ9qZ 3NESeUOI94lOD89RP1liKahMv00wUTlrZxcjjijA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729579AbgHXIsj (ORCPT ); Mon, 24 Aug 2020 04:48:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:49100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729517AbgHXIsO (ORCPT ); Mon, 24 Aug 2020 04:48:14 -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 CB671204FD; Mon, 24 Aug 2020 08:48:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258894; bh=JWJlvUsK6gkl2cRksfkM0gxOVpkwCKdmM0aaXQwlZik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Loz61TVh/rUgxrAEQiu7LYVjAlcacezBPlKehi7d+JDHweTqelVPQBgQwMCCPF4lc I21YFksyLcg2cH2yvikHjl08hmoMlC4+C+G9gHcNTra4cc2dr+0twpHme6WAaNZuwP 1Hdn8it2oPB/dyboU8ilJP3toLjjkzsO8W+n9hsw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Claudio Imbrenda , Heiko Carstens , Sasha Levin Subject: [PATCH 5.4 083/107] s390/ptrace: fix storage key handling Date: Mon, 24 Aug 2020 10:30:49 +0200 Message-Id: <20200824082409.228245728@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824082405.020301642@linuxfoundation.org> References: <20200824082405.020301642@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Heiko Carstens [ Upstream commit fd78c59446b8d050ecf3e0897c5a486c7de7c595 ] The key member of the runtime instrumentation control block contains only the access key, not the complete storage key. Therefore the value must be shifted by four bits. Since existing user space does not necessarily query and set the access key correctly, just ignore the user space provided key and use the correct one. Note: this is only relevant for debugging purposes in case somebody compiles a kernel with a default storage access key set to a value not equal to zero. Fixes: 262832bc5acd ("s390/ptrace: add runtime instrumention register get/set") Reported-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/kernel/ptrace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 5aa786063eb3e..c6aef2ecf2890 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -1283,7 +1283,6 @@ static bool is_ri_cb_valid(struct runtime_instr_cb *cb) cb->pc == 1 && cb->qc == 0 && cb->reserved2 == 0 && - cb->key == PAGE_DEFAULT_KEY && cb->reserved3 == 0 && cb->reserved4 == 0 && cb->reserved5 == 0 && @@ -1347,7 +1346,11 @@ static int s390_runtime_instr_set(struct task_struct *target, kfree(data); return -EINVAL; } - + /* + * Override access key in any case, since user space should + * not be able to set it, nor should it care about it. + */ + ri_cb.key = PAGE_DEFAULT_KEY >> 4; preempt_disable(); if (!target->thread.ri_cb) target->thread.ri_cb = data; -- 2.25.1