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=-9.8 required=3.0 tests=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 00113C2D0CE for ; Sun, 29 Dec 2019 18:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCC65206DB for ; Sun, 29 Dec 2019 18:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577642554; bh=Jr8t59oHCU9w4yalef6PIXJgCoErclWXFy6+f+VOfrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yLGptPkhUvEB8DXJWWKfQSmSv+DKPY3z/iiR+gBX5IhCRoTdF/iBAsT2jdrWdzuoj 1vY8NVVX6tfAiCVtEVgrqCH+TonUfeAiCcW0TwAWfiuXeKE1QoqOD6am9nvpg98sl8 8G/oV0B/qz5Chjtaz/PWuzIkpqtA05D25dCqQRlE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387684AbfL2SCd (ORCPT ); Sun, 29 Dec 2019 13:02:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:42812 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732737AbfL2Rym (ORCPT ); Sun, 29 Dec 2019 12:54:42 -0500 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 7242D206DB; Sun, 29 Dec 2019 17:54:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577642081; bh=Jr8t59oHCU9w4yalef6PIXJgCoErclWXFy6+f+VOfrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r/oAt46Cqt/pCGHDGq5lRkxZ9EfCTUetNc3LdbbecnwYVOHEjAzJovALdh2kVm0oV urvLL/M96718S/oJdmFYfGzfwkx7wcBCeuVKDi8lgot6dYjFKhMXDmOQIj+5qfO4WW +gnb+e9iYFHTncfslQcMBP4RUDbf3T4AscsIr1OI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Philipp Rudo , Vasily Gorbik , Sasha Levin Subject: [PATCH 5.4 335/434] s390/kasan: support memcpy_real with TRACE_IRQFLAGS Date: Sun, 29 Dec 2019 18:26:28 +0100 Message-Id: <20191229172724.220761956@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191229172702.393141737@linuxfoundation.org> References: <20191229172702.393141737@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: Vasily Gorbik [ Upstream commit 13f9bae579c6bd051e58f326913dd09af1291208 ] Currently if the kernel is built with CONFIG_TRACE_IRQFLAGS and KASAN and used as crash kernel it crashes itself due to trace_hardirqs_off/trace_hardirqs_on being called with DAT off. This happens because trace_hardirqs_off/trace_hardirqs_on are instrumented and kasan code tries to perform access to shadow memory to validate memory accesses. Kasan shadow memory is populated with vmemmap, so all accesses require DAT on. memcpy_real could be called with DAT on or off (with kasan enabled DAT is set even before early code is executed). Make sure that trace_hardirqs_off/trace_hardirqs_on are called with DAT on and only actual __memcpy_real is called with DAT off. Also annotate __memcpy_real and _memcpy_real with __no_sanitize_address to avoid further problems due to switching DAT off. Reviewed-by: Philipp Rudo Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/mm/maccess.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 1864a8bb9622..59ad7997fed1 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -70,7 +70,7 @@ void notrace s390_kernel_write(void *dst, const void *src, size_t size) spin_unlock_irqrestore(&s390_kernel_write_lock, flags); } -static int __memcpy_real(void *dest, void *src, size_t count) +static int __no_sanitize_address __memcpy_real(void *dest, void *src, size_t count) { register unsigned long _dest asm("2") = (unsigned long) dest; register unsigned long _len1 asm("3") = (unsigned long) count; @@ -91,19 +91,23 @@ static int __memcpy_real(void *dest, void *src, size_t count) return rc; } -static unsigned long _memcpy_real(unsigned long dest, unsigned long src, - unsigned long count) +static unsigned long __no_sanitize_address _memcpy_real(unsigned long dest, + unsigned long src, + unsigned long count) { int irqs_disabled, rc; unsigned long flags; if (!count) return 0; - flags = __arch_local_irq_stnsm(0xf8UL); + flags = arch_local_irq_save(); irqs_disabled = arch_irqs_disabled_flags(flags); if (!irqs_disabled) trace_hardirqs_off(); + __arch_local_irq_stnsm(0xf8); // disable DAT rc = __memcpy_real((void *) dest, (void *) src, (size_t) count); + if (flags & PSW_MASK_DAT) + __arch_local_irq_stosm(0x04); // enable DAT if (!irqs_disabled) trace_hardirqs_on(); __arch_local_irq_ssm(flags); -- 2.20.1