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 BA989EEB560 for ; Fri, 8 Sep 2023 18:03:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231218AbjIHSDg (ORCPT ); Fri, 8 Sep 2023 14:03:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245727AbjIHSDX (ORCPT ); Fri, 8 Sep 2023 14:03:23 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E18126A5; Fri, 8 Sep 2023 11:02:49 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3866EC43395; Fri, 8 Sep 2023 18:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694196095; bh=w6qHlNyMN4kEXbZIw0AZpfeiBoj3N8yPUsiJu+tEJe4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ByE9QECGOQVCSAeaw041aGnfx/KLkCtgqGzVlUQsQUfHCcI4KPXuB2IyDSz4Mwzja WPZGID9n88nTGVnBI+GULLWJWuwX8r7OPBkMgsSBQnAG5lOv0waJ6+mQQGQxflirtu HCwmj1kdRg6jvmgXbLcklnd2yXYhac0oSckyB5XcOyBaDjPaHlaQHyw42JsGfvmfTE 5R/S6yhuZaA8qsRo3P+zdSBPOnjJ95NNJxpuzOrGJqRKVs0Cnz5koWM7pK+0YUuKpH K3qnHgynLcTY+JtLpYQHMYpZf8sgkKRE5bV7TjDVmPX811vE94i5fwbQpbn0291ktJ k73u8Yfw+h7fw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexander Gordeev , Heiko Carstens , Sasha Levin , gor@linux.ibm.com, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 6.4 07/13] s390/boot: cleanup number of page table levels setup Date: Fri, 8 Sep 2023 14:00:53 -0400 Message-Id: <20230908180100.3458151-7-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908180100.3458151-1-sashal@kernel.org> References: <20230908180100.3458151-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.4.15 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Gordeev [ Upstream commit 8ddccc8a7d06f7ea4d8579970c95609d1b1de77b ] The separate vmalloc area size check against _REGION2_SIZE is needed in case user provided insanely large value using vmalloc= kernel command line parameter. That could lead to overflow and selecting 3 page table levels instead of 4. Use size_add() for the overflow check and get rid of the extra vmalloc area check. With the current values of CONFIG_MAX_PHYSMEM_BITS and PAGES_PER_SECTION the sum of maximal possible size of identity mapping and vmemmap area (derived from these macros) plus modules area size MODULES_LEN can not overflow. Thus, that sum is used as first addend while vmalloc area size is second addend for size_add(). Suggested-by: Heiko Carstens Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/boot/startup.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 64bd7ac3e35d1..f8d0550e5d2af 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -176,6 +176,7 @@ static unsigned long setup_kernel_memory_layout(void) unsigned long asce_limit; unsigned long rte_size; unsigned long pages; + unsigned long vsize; unsigned long vmax; pages = ident_map_size / PAGE_SIZE; @@ -183,11 +184,9 @@ static unsigned long setup_kernel_memory_layout(void) vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page); /* choose kernel address space layout: 4 or 3 levels. */ - vmemmap_start = round_up(ident_map_size, _REGION3_SIZE); - if (IS_ENABLED(CONFIG_KASAN) || - vmalloc_size > _REGION2_SIZE || - vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN > - _REGION2_SIZE) { + vsize = round_up(ident_map_size, _REGION3_SIZE) + vmemmap_size + MODULES_LEN; + vsize = size_add(vsize, vmalloc_size); + if (IS_ENABLED(CONFIG_KASAN) || (vsize > _REGION2_SIZE)) { asce_limit = _REGION1_SIZE; rte_size = _REGION2_SIZE; } else { -- 2.40.1