From patchwork Mon Sep 21 16:28:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 263628 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=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 40380C43465 for ; Mon, 21 Sep 2020 16:53:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0131B235FD for ; Mon, 21 Sep 2020 16:53:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600707220; bh=fXVGge8+cR5WWy113wFwpWFgNcSHFw7sOKDTjkPBGZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lT8jdwZWI0PLKG/h/AmsNO89zyNws9zXRGJlhBQoRvRckr2mMacwkt55BEA8YAg4M y8vR2B6dCN0p85Y5XO7Qj3HdMd4pKYg9wJZ0kcpvms+hJAPJW/j7lzjvfAMLLU/mJf irZR6Y6MxPBqxgV81OsBYxWTLm0oOZdsUVvnDjfw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728678AbgIUQrL (ORCPT ); Mon, 21 Sep 2020 12:47:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:53500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728045AbgIUQq5 (ORCPT ); Mon, 21 Sep 2020 12:46:57 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 D69F423888; Mon, 21 Sep 2020 16:46:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706816; bh=fXVGge8+cR5WWy113wFwpWFgNcSHFw7sOKDTjkPBGZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mrnWM+j6UG14tXjMsmHk8Zm6YeI009RvP4dZmZ5Lnw00fn+cS1yEE364D5LWaI221 Nqwp7o8pQGy06xTrBFq/e5DL2l1IwZ6m5JD3cTAufOgLbeTfn8SkSm52TWnwYy4uPo BTJEzpkHArMUuGf1Bp/h2ZB1AY6ga4n0eAp5SjGM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Janosch Frank , Claudio Imbrenda , Cornelia Huck , Christian Borntraeger , Heiko Carstens , Vasily Gorbik Subject: [PATCH 5.8 106/118] s390: add 3f program exception handler Date: Mon, 21 Sep 2020 18:28:38 +0200 Message-Id: <20200921162041.295334701@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162036.324813383@linuxfoundation.org> References: <20200921162036.324813383@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Janosch Frank commit cd4d3d5f21ddbfae3f686ac0ff405f21f7847ad3 upstream. Program exception 3f (secure storage violation) can only be detected when the CPU is running in SIE with a format 4 state description, e.g. running a protected guest. Because of this and because user space partly controls the guest memory mapping and can trigger this exception, we want to send a SIGSEGV to the process running the guest and not panic the kernel. Signed-off-by: Janosch Frank Cc: # 5.7 Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers") Reviewed-by: Claudio Imbrenda Reviewed-by: Cornelia Huck Acked-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/entry.h | 1 + arch/s390/kernel/pgm_check.S | 2 +- arch/s390/mm/fault.c | 20 ++++++++++++++++++++ 3 files changed, 22 insertions(+), 1 deletion(-) --- a/arch/s390/kernel/entry.h +++ b/arch/s390/kernel/entry.h @@ -26,6 +26,7 @@ void do_protection_exception(struct pt_r void do_dat_exception(struct pt_regs *regs); void do_secure_storage_access(struct pt_regs *regs); void do_non_secure_storage_access(struct pt_regs *regs); +void do_secure_storage_violation(struct pt_regs *regs); void addressing_exception(struct pt_regs *regs); void data_exception(struct pt_regs *regs); --- a/arch/s390/kernel/pgm_check.S +++ b/arch/s390/kernel/pgm_check.S @@ -80,7 +80,7 @@ PGM_CHECK(do_dat_exception) /* 3b */ PGM_CHECK_DEFAULT /* 3c */ PGM_CHECK(do_secure_storage_access) /* 3d */ PGM_CHECK(do_non_secure_storage_access) /* 3e */ -PGM_CHECK_DEFAULT /* 3f */ +PGM_CHECK(do_secure_storage_violation) /* 3f */ PGM_CHECK(monitor_event_exception) /* 40 */ PGM_CHECK_DEFAULT /* 41 */ PGM_CHECK_DEFAULT /* 42 */ --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -875,6 +875,21 @@ void do_non_secure_storage_access(struct } NOKPROBE_SYMBOL(do_non_secure_storage_access); +void do_secure_storage_violation(struct pt_regs *regs) +{ + /* + * Either KVM messed up the secure guest mapping or the same + * page is mapped into multiple secure guests. + * + * This exception is only triggered when a guest 2 is running + * and can therefore never occur in kernel context. + */ + printk_ratelimited(KERN_WARNING + "Secure storage violation in task: %s, pid %d\n", + current->comm, current->pid); + send_sig(SIGSEGV, current, 0); +} + #else void do_secure_storage_access(struct pt_regs *regs) { @@ -885,4 +900,9 @@ void do_non_secure_storage_access(struct { default_trap_handler(regs); } + +void do_secure_storage_violation(struct pt_regs *regs) +{ + default_trap_handler(regs); +} #endif