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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A0C7C4332F for ; Sun, 29 Oct 2023 23:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231828AbjJ2Xdb (ORCPT ); Sun, 29 Oct 2023 19:33:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232536AbjJ2XdO (ORCPT ); Sun, 29 Oct 2023 19:33:14 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AF6A270D; Sun, 29 Oct 2023 15:55:55 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89F9FC433C8; Sun, 29 Oct 2023 22:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698620147; bh=KyghjT8fjcHLeQ851UGSAKU0YWIhtmCAbJN2wBmIgz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qTebr8vJKhgpa5Z174zEAj3+X02BqURKnnmxfC44I8kfp7fruI9OWG+IhDEu0oB5S 7sAu6lYxsSto/DuvmWRF+inhMV9GE19zWhYQRIwJTnHRMjlttKjDdOQmpqrQPqYB/Y IFdvaC5LT+Omf64oGn1t+O39N2iT9uzczTseXi6q2lZuFhP9fFpcQZAhf1sfSM/ZE4 vEtModWg5Jd89tpBy3LCyID83leTNNW4YUpdBm3tlWdrO57q4wX0CxM24D56TX2Saz QrLk/VhZa9IZGpzqgzMyZDO5IWPXkCCnLiMv1IpJgMwUZkBrxeFhqMTAJj/nUwjHKQ jJmWf5adsI92A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vasily Gorbik , Heiko Carstens , Gerald Schaefer , Sasha Levin , agordeev@linux.ibm.com, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 6.5 30/52] s390/kasan: handle DCSS mapping in memory holes Date: Sun, 29 Oct 2023 18:53:17 -0400 Message-ID: <20231029225441.789781-30-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231029225441.789781-1-sashal@kernel.org> References: <20231029225441.789781-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.5.9 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vasily Gorbik [ Upstream commit 327899674eef18f96644be87aa5510b7523fe4f6 ] When physical memory is defined under z/VM using DEF STOR CONFIG, there may be memory holes that are not hotpluggable memory. In such cases, DCSS mapping could be placed in one of these memory holes. Subsequently, attempting memory access to such DCSS mapping would result in a kasan failure because there is no shadow memory mapping for it. To maintain consistency with cases where DCSS mapping is positioned after the kernel identity mapping, which is then covered by kasan zero shadow mapping, handle the scenario above by populating zero shadow mapping for memory holes where DCSS mapping could potentially be placed. Reviewed-by: Heiko Carstens Reviewed-by: Gerald Schaefer Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/boot/vmem.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c index c67f59db7a512..f66d642251fe8 100644 --- a/arch/s390/boot/vmem.c +++ b/arch/s390/boot/vmem.c @@ -57,6 +57,7 @@ static void kasan_populate_shadow(void) pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY); pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY); p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY); + unsigned long memgap_start = 0; unsigned long untracked_end; unsigned long start, end; int i; @@ -101,8 +102,12 @@ static void kasan_populate_shadow(void) * +- shadow end ----+---------+- shadow end ---+ */ - for_each_physmem_usable_range(i, &start, &end) + for_each_physmem_usable_range(i, &start, &end) { kasan_populate(start, end, POPULATE_KASAN_MAP_SHADOW); + if (memgap_start && physmem_info.info_source == MEM_DETECT_DIAG260) + kasan_populate(memgap_start, start, POPULATE_KASAN_ZERO_SHADOW); + memgap_start = end; + } if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { untracked_end = VMALLOC_START; /* shallowly populate kasan shadow for vmalloc and modules */ -- 2.42.0