From patchwork Thu Dec 6 12:24:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10715745 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3E49C109C for ; Thu, 6 Dec 2018 12:25:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 296CD292C8 for ; Thu, 6 Dec 2018 12:25:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1D28C2D564; Thu, 6 Dec 2018 12:25:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CCE14297D0 for ; Thu, 6 Dec 2018 12:25:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729639AbeLFMZE (ORCPT ); Thu, 6 Dec 2018 07:25:04 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:35671 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729619AbeLFMZD (ORCPT ); Thu, 6 Dec 2018 07:25:03 -0500 Received: by mail-wm1-f67.google.com with SMTP id c126so842915wmh.0 for ; Thu, 06 Dec 2018 04:25:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=G5Ka/D9ThH8pnE4eoPJ0OLfzNTsBwnEIL720J8sMTz0=; b=dhrVAvtpao4EYg7FPVcAkM1wtgiCBBI9ASJhoyX/vv+zvJ5zk95ov0eIQZZadClZMy C9GuvdBwcXqwqHElxuDXEIz889yekq6iNXAe7oMkWsjIBsJ9rt8EwF02GzX729gCYrKI ynUxvY44E8YwCyPeGFjutDX/Ka4dGW+JpBDkXy6pmjwo/Rq5KY/j3JJ5r3kwmG4hQNSM 4stTjLLbbsYQYnRqF3a4u1Q0q/jojd03Tl+wDvTna6jK/WpUnbO2YeYOwxaFWZG0Yj1N LhSyyeYMWO8CsVUWLNmXcxBL3cZLwTNssIUkFccRsslhrLDvpgG3oyko66ErTK7fQUUV ZqYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=G5Ka/D9ThH8pnE4eoPJ0OLfzNTsBwnEIL720J8sMTz0=; b=ivv/iQ+FeVD60xGLt/zRBt7lBL59tv8wDgYdRVJNx9H/Eu/jVh64GdhNxgzauckSbW 0JiDKTSRs+LenIiMoU1IE/PPVGVXBB68RL5gZIjM3+Q3BOzwghYf8creNoYmdh2aD3kS +GUAlsdqP0tk1YsZTnyi5ZWFNjdlKDPnRGkhAtZ6Aqw3yoMQXVZfzy4iioMu/8hj6vJ0 BLt3KBcfegq09dsdHzTV396NX35eBzPkmh+NWZRTaQHmhl6AJFIagymyewy2ferZ8UcI C45XhLsCKVoQWR6Nl2m8bOdk9uxG+m1XYnBSIkm+KuPnUYlLpHKjY4ynvDnTD3dWLvpe ejpw== X-Gm-Message-State: AA+aEWbTTCRn1O63VwhvTjqhzhH2b+7kqPx4Pe0syBRcNCps7YOyY2KG HT69ZBl7aPZ29TfNnxx2SfVqsA== X-Google-Smtp-Source: AFSGD/XJ8zcmMWXD8FWzGxaH3vNIgkyiPtwnihpR7W2ZVOr16EQd1yHbYp8lY9MsaH6CEj9t73DTeA== X-Received: by 2002:a1c:8d49:: with SMTP id p70mr1774408wmd.68.1544099101009; Thu, 06 Dec 2018 04:25:01 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:3180:41f8:3010:ff61]) by smtp.gmail.com with ESMTPSA id j8sm339988wrt.40.2018.12.06.04.24.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Dec 2018 04:25:00 -0800 (PST) From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan , Andrey Konovalov Subject: [PATCH v13 08/25] kasan: initialize shadow to 0xff for tag-based mode Date: Thu, 6 Dec 2018 13:24:26 +0100 Message-Id: <5cc1b789aad7c99cf4f3ec5b328b147ad53edb40.1544099024.git.andreyknvl@google.com> X-Mailer: git-send-email 2.20.0.rc1.387.gf8505762e3-goog In-Reply-To: References: MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A tag-based KASAN shadow memory cell contains a memory tag, that corresponds to the tag in the top byte of the pointer, that points to that memory. The native top byte value of kernel pointers is 0xff, so with tag-based KASAN we need to initialize shadow memory to 0xff. Reviewed-by: Andrey Ryabinin Reviewed-by: Dmitry Vyukov Signed-off-by: Andrey Konovalov --- arch/arm64/mm/kasan_init.c | 15 +++++++++++++-- include/linux/kasan.h | 8 ++++++++ mm/kasan/common.c | 3 ++- 3 files changed, 23 insertions(+), 3 deletions(-) diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 4ebc19422931..7a4a0904cac8 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -43,6 +43,15 @@ static phys_addr_t __init kasan_alloc_zeroed_page(int node) return __pa(p); } +static phys_addr_t __init kasan_alloc_raw_page(int node) +{ + void *p = memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE, + __pa(MAX_DMA_ADDRESS), + MEMBLOCK_ALLOC_ACCESSIBLE, + node); + return __pa(p); +} + static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node, bool early) { @@ -92,7 +101,9 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, do { phys_addr_t page_phys = early ? __pa_symbol(kasan_early_shadow_page) - : kasan_alloc_zeroed_page(node); + : kasan_alloc_raw_page(node); + if (!early) + memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); next = addr + PAGE_SIZE; set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); @@ -239,7 +250,7 @@ void __init kasan_init(void) pfn_pte(sym_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO)); - memset(kasan_early_shadow_page, 0, PAGE_SIZE); + memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); /* At this point kasan is fully initialized. Enable error messages */ diff --git a/include/linux/kasan.h b/include/linux/kasan.h index ec22d548d0d7..c56af24bd3e7 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -153,6 +153,8 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } #ifdef CONFIG_KASAN_GENERIC +#define KASAN_SHADOW_INIT 0 + void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); @@ -163,4 +165,10 @@ static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} #endif /* CONFIG_KASAN_GENERIC */ +#ifdef CONFIG_KASAN_SW_TAGS + +#define KASAN_SHADOW_INIT 0xFF + +#endif /* CONFIG_KASAN_SW_TAGS */ + #endif /* LINUX_KASAN_H */ diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 5f68c93734ba..7134e75447ff 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -473,11 +473,12 @@ int kasan_module_alloc(void *addr, size_t size) ret = __vmalloc_node_range(shadow_size, 1, shadow_start, shadow_start + shadow_size, - GFP_KERNEL | __GFP_ZERO, + GFP_KERNEL, PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE, __builtin_return_address(0)); if (ret) { + __memset(ret, KASAN_SHADOW_INIT, shadow_size); find_vm_area(addr)->flags |= VM_KASAN; kmemleak_ignore(ret); return 0;