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=ham 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 2629CC433E1 for ; Mon, 24 Aug 2020 08:36:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAC15221E2 for ; Mon, 24 Aug 2020 08:36:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258186; bh=an6+2DqmminxtMIu4A/ZhdmOYJXJxJgM44v0lI1h1gg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iTiQRNKbHiiEnB1zYY9w7NisWMVCVxvozt6L4muYnZv5d55R4Dm3TY9zpypH53KHY UNGcdzYMViKaEC5I8DEJ0yW0zDm7Gw/wZbGqmFF8CnviNvulNKduFWIOrGkN0ePoYT d2DbIUq9tcKDMYZCEIWNP0z7LOvy5Ljg8GxnQAwQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726874AbgHXIgZ (ORCPT ); Mon, 24 Aug 2020 04:36:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:48206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728213AbgHXIgG (ORCPT ); Mon, 24 Aug 2020 04:36:06 -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 978C4206F0; Mon, 24 Aug 2020 08:36:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258166; bh=an6+2DqmminxtMIu4A/ZhdmOYJXJxJgM44v0lI1h1gg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oG+HE6g7MHTVnqkCbs6v3OsuEpW6z1kvo7Gk+sAiRzz+M7IoJm/hbtlXp31Ns3vhU EWH4QezB6Xswppt+JDAXBa3ZJ+wDfqEi75//wRj9wfUXWs33JodBlf/kJmmWS2Ey8B ukrc8KGLToqJ5ayCkrQNNj2woO9sy+p9rHTR1vcY= 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 5.8 099/148] s390/ptrace: fix storage key handling Date: Mon, 24 Aug 2020 10:29:57 +0200 Message-Id: <20200824082418.780992297@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824082413.900489417@linuxfoundation.org> References: <20200824082413.900489417@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 3cc15c0662983..2924f236d89c6 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -1310,7 +1310,6 @@ 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 && @@ -1374,7 +1373,11 @@ 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