From patchwork Tue Jan 12 23:49:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12015487 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 438D9C433DB for ; Tue, 12 Jan 2021 23:49:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DE03223132 for ; Tue, 12 Jan 2021 23:49:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE03223132 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7A87D6B011A; Tue, 12 Jan 2021 18:49:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 756DD6B011B; Tue, 12 Jan 2021 18:49:17 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 671236B011C; Tue, 12 Jan 2021 18:49:17 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0154.hostedemail.com [216.40.44.154]) by kanga.kvack.org (Postfix) with ESMTP id 4E88F6B011A for ; Tue, 12 Jan 2021 18:49:17 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 159D21EE6 for ; Tue, 12 Jan 2021 23:49:17 +0000 (UTC) X-FDA: 77698766754.20.curve25_100993127519 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id EE390180C07A3 for ; Tue, 12 Jan 2021 23:49:16 +0000 (UTC) X-HE-Tag: curve25_100993127519 X-Filterd-Recvd-Size: 3981 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf39.hostedemail.com (Postfix) with ESMTP for ; Tue, 12 Jan 2021 23:49:16 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 2175223135; Tue, 12 Jan 2021 23:49:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1610495355; bh=NSG9iDmXs2vC1wTygyubD7mqFbb432cVnyBE6JWzfhc=; h=Date:From:To:Subject:In-Reply-To:From; b=Xo5NvK1Bf1m9mVo1KVKYEsBzLJ0sPAOUrRgP9/3ngQlGKf7eQ2kkzpldyHye61KiO 31jA5Tj3J8Urw89dB3InYwND0+rbf/jQNBrIoOxkvXig+aQQrh0u/663FZKNFygHfz VeeEHEV4Fp2IUZOL+mItT+HBqmR8304JkgoIaDqU= Date: Tue, 12 Jan 2021 15:49:14 -0800 From: Andrew Morton To: akpm@linux-foundation.org, ardb@kernel.org, aryabinin@virtuozzo.com, dvyukov@google.com, glider@google.com, guo.ziliang@zte.com.cn, linus.walleij@linaro.org, linux-mm@kvack.org, linux@armlinux.org.uk, liu.hailong6@zte.com.cn, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 04/10] arm/kasan: fix the array size of kasan_early_shadow_pte[] Message-ID: <20210112234914.NwudbAxXv%akpm@linux-foundation.org> In-Reply-To: <20210112154839.abeb6e57de79480059fd9b0e@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Hailong Liu Subject: arm/kasan: fix the array size of kasan_early_shadow_pte[] The size of kasan_early_shadow_pte[] now is PTRS_PER_PTE which defined to 512 for arm architecture. This means that it only covers the prev Linux pte entries, but not the HWTABLE pte entries for arm. The reason it works well current is that the symbol kasan_early_shadow_page immediately following kasan_early_shadow_pte in memory is page aligned, which makes kasan_early_shadow_pte look like a 4KB size array. But we can't ensure the order always right with different compiler/linker, nor more bss symbols be introduced. We had a test with QEMU + vexpress：put a 512KB-size symbol with attribute __section(".bss..page_aligned") after kasan_early_shadow_pte, and poison it after kasan_early_init(). Then enabled CONFIG_KASAN, it failed to boot up. Link: https://lkml.kernel.org/r/20210109044622.8312-1-hailongliiu@yeah.net Signed-off-by: Hailong Liu Signed-off-by: Ziliang Guo Reviewed-by: Linus Walleij Cc: Andrey Ryabinin Cc: Russell King Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Ard Biesheuvel Signed-off-by: Andrew Morton --- include/linux/kasan.h | 6 +++++- mm/kasan/init.c | 3 ++- 2 files changed, 7 insertions(+), 2 deletions(-) --- a/include/linux/kasan.h~arm-kasan-fix-the-arry-size-of-kasan_early_shadow_pte +++ a/include/linux/kasan.h @@ -35,8 +35,12 @@ struct kunit_kasan_expectation { #define KASAN_SHADOW_INIT 0 #endif +#ifndef PTE_HWTABLE_PTRS +#define PTE_HWTABLE_PTRS 0 +#endif + extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; -extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE]; +extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS]; extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD]; extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD]; extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D]; --- a/mm/kasan/init.c~arm-kasan-fix-the-arry-size-of-kasan_early_shadow_pte +++ a/mm/kasan/init.c @@ -64,7 +64,8 @@ static inline bool kasan_pmd_table(pud_t return false; } #endif -pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss; +pte_t kasan_early_shadow_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS] + __page_aligned_bss; static inline bool kasan_pte_table(pmd_t pmd) {