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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 49880C43463 for ; Fri, 18 Sep 2020 12:52:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BADB423447 for ; Fri, 18 Sep 2020 12:52:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OPEfNMvD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726507AbgIRMwZ (ORCPT ); Fri, 18 Sep 2020 08:52:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726064AbgIRMwZ (ORCPT ); Fri, 18 Sep 2020 08:52:25 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E23FDC06174A for ; Fri, 18 Sep 2020 05:52:24 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id l9so5468831wme.3 for ; Fri, 18 Sep 2020 05:52:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=9QeHCUfQyRWNLF4v5BVGx0mOMMB1DfrWlk1Da5oWEr0=; b=OPEfNMvDbr1GA16O+bD1EVvXU3RwiktLp1v4SspTfzVHQ3b6wc3DsOnL2yFV/7OJUX vJ86IOK7F7BbktHLeLTU4gwiJlcEho5MTNOtW2ME95PmxEoVh3EivAR0i7EzWek/DQ65 0Gcho1HTrLf4Rus/rXNQXoYuXPIyirZTjVrXQWGo57ObWUwFDkqmjdswWagbQK17pKvg qOtIEOxBuS0Kl59UHyNYRZBb1BkFJxXOf8jOsNo34C1fv1A9zYG7wP0awOp76oxY/VBl hm9z5eWcdjEUOFpxnP8+Uhkt7kqLMpfyk1Mqu2n2rHZTO2BiEEQ7Ade2j+xiZjgOtsLW gsSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=9QeHCUfQyRWNLF4v5BVGx0mOMMB1DfrWlk1Da5oWEr0=; b=jCnqDGfM+l+rVjKGHMzizz1Pn6RCx+0ZKyV4c7skF7wXqTBxAYRRWSek7o8W4yuHDF KseMU3r6287XRohrpKFEBdhZdWZos4Em/HKwF5aPTdcZFqkKAK2NRmIxw4XuH6nbU8VE IWVRJhUwBF4SRwX9x1ybvMET3duR2+9mZ2+3wfydsLXhiNUeCqi8Z533oY2ykSxkVn0Z rlG5r5gHyrvJ/moxFUOsy8N6q5C+MhIi42rZkSx+MA30wPmsr0R8CQ+fROB3gKH8hLzo vX0xca2Rbdk1JhnocO0IfErqHUoqngh/8PK6LOvVVOarHB7pmk23FZ4aDLVZurZjvwmc t4KQ== X-Gm-Message-State: AOAM5331VE7TVkIfb1DORbFjrxwEN/cpFEpH/5KA4AopZl3UqwXTSLs9 tF/kZcIRgNKj1Cnji5S0VIcb7Q== X-Google-Smtp-Source: ABdhPJzZiAEODydg/nQYzxZIt0k+pmAXCO33IML30l+9SgWT24seOlXi9uwnfVeunAVfJvZCSWDf5Q== X-Received: by 2002:a7b:ce96:: with SMTP id q22mr14478150wmj.132.1600433543383; Fri, 18 Sep 2020 05:52:23 -0700 (PDT) Received: from elver.google.com ([100.105.32.75]) by smtp.gmail.com with ESMTPSA id i16sm5028940wrq.73.2020.09.18.05.52.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Sep 2020 05:52:22 -0700 (PDT) Date: Fri, 18 Sep 2020 14:52:16 +0200 From: Marco Elver To: Andrey Konovalov Cc: Dmitry Vyukov , Vincenzo Frascino , Catalin Marinas , kasan-dev@googlegroups.com, Andrey Ryabinin , Alexander Potapenko , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 33/37] kasan, arm64: implement HW_TAGS runtime Message-ID: <20200918125216.GD2384246@elver.google.com> References: <74133d1a57c47cb8fec791dd5d1e6417b0579fc3.1600204505.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <74133d1a57c47cb8fec791dd5d1e6417b0579fc3.1600204505.git.andreyknvl@google.com> User-Agent: Mutt/1.14.4 (2020-06-18) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Sorry for the additional email on this patch; trying to consolidate comments now. ] On Tue, Sep 15, 2020 at 11:16PM +0200, Andrey Konovalov wrote: > Provide implementation of KASAN functions required for the hardware > tag-based mode. Those include core functions for memory and pointer > tagging (tags_hw.c) and bug reporting (report_tags_hw.c). Also adapt > common KASAN code to support the new mode. > > Signed-off-by: Andrey Konovalov > Signed-off-by: Vincenzo Frascino > --- > Change-Id: I8a8689ba098174a4d0ef3f1d008178387c80ee1c > --- > arch/arm64/include/asm/memory.h | 4 +- > arch/arm64/kernel/setup.c | 1 - > include/linux/kasan.h | 6 +-- > include/linux/mm.h | 2 +- > include/linux/page-flags-layout.h | 2 +- > mm/kasan/Makefile | 5 ++ > mm/kasan/common.c | 14 +++--- > mm/kasan/kasan.h | 17 +++++-- > mm/kasan/report_tags_hw.c | 47 +++++++++++++++++++ > mm/kasan/report_tags_sw.c | 2 +- > mm/kasan/shadow.c | 2 +- > mm/kasan/tags_hw.c | 78 +++++++++++++++++++++++++++++++ > mm/kasan/tags_sw.c | 2 +- > 13 files changed, 162 insertions(+), 20 deletions(-) > create mode 100644 mm/kasan/report_tags_hw.c > create mode 100644 mm/kasan/tags_hw.c [...] > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index 41c7f1105eaa..412a23d1546b 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -118,7 +118,7 @@ void kasan_free_pages(struct page *page, unsigned int order) > */ > static inline unsigned int optimal_redzone(unsigned int object_size) > { > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > + if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) > return 0; > > return > @@ -183,14 +183,14 @@ size_t kasan_metadata_size(struct kmem_cache *cache) > struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, > const void *object) > { > - return (void *)object + cache->kasan_info.alloc_meta_offset; > + return (void *)reset_tag(object) + cache->kasan_info.alloc_meta_offset; > } > > struct kasan_free_meta *get_free_info(struct kmem_cache *cache, > const void *object) > { > BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32); > - return (void *)object + cache->kasan_info.free_meta_offset; > + return (void *)reset_tag(object) + cache->kasan_info.free_meta_offset; > } > > void kasan_poison_slab(struct page *page) > @@ -272,7 +272,8 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, > alloc_info = get_alloc_info(cache, object); > __memset(alloc_info, 0, sizeof(*alloc_info)); Suggested edit below (assuming the line-break wasn't intentional; this should still be within checkpatch.pl's 100 col limit): ------ - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || - IS_ENABLED(CONFIG_KASAN_HW_TAGS)) + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) object = set_tag(object, assign_tag(cache, object, true, false)); @@ -343,8 +342,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, redzone_end = round_up((unsigned long)object + cache->object_size, KASAN_GRANULE_SIZE); - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || - IS_ENABLED(CONFIG_KASAN_HW_TAGS)) + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) tag = assign_tag(cache, object, false, keep_tag); ------ > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || > + IS_ENABLED(CONFIG_KASAN_HW_TAGS)) > object = set_tag(object, > assign_tag(cache, object, true, false)); > > @@ -342,10 +343,11 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, > redzone_end = round_up((unsigned long)object + cache->object_size, > KASAN_GRANULE_SIZE); > > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || > + IS_ENABLED(CONFIG_KASAN_HW_TAGS)) > tag = assign_tag(cache, object, false, keep_tag); > > - /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */ > + /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */ > kasan_unpoison_memory(set_tag(object, tag), size); > kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start, > KASAN_KMALLOC_REDZONE); [...] > diff --git a/mm/kasan/report_tags_hw.c b/mm/kasan/report_tags_hw.c > new file mode 100644 > index 000000000000..c2f73c46279a > --- /dev/null > +++ b/mm/kasan/report_tags_hw.c > @@ -0,0 +1,47 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * This file contains hardware tag-based KASAN specific error reporting code. > + * > + * Copyright (c) 2020 Google, Inc. > + * Author: Andrey Konovalov > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * I do not think we put the "This program is ..." preamble in new files anymore. It should be covered by SPDX tag above. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include [...] > diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c > index 4888084ecdfc..ca69726adf8f 100644 > --- a/mm/kasan/shadow.c > +++ b/mm/kasan/shadow.c > @@ -111,7 +111,7 @@ void kasan_unpoison_memory(const void *address, size_t size) > > if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > *shadow = tag; > - else > + else /* CONFIG_KASAN_GENERIC */ > *shadow = size & KASAN_GRANULE_MASK; > } > } > diff --git a/mm/kasan/tags_hw.c b/mm/kasan/tags_hw.c > new file mode 100644 > index 000000000000..c93d43379e39 > --- /dev/null > +++ b/mm/kasan/tags_hw.c > @@ -0,0 +1,78 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * This file contains core hardware tag-based KASAN code. > + * > + * Copyright (c) 2020 Google, Inc. > + * Author: Andrey Konovalov > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * I do not think we put the "This program is ..." preamble in new files anymore. It should be covered by SPDX tag above. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "kasan.h" > + > +void kasan_init_tags(void) > +{ > + init_tags(KASAN_TAG_MAX); > +} > + > +void *kasan_reset_tag(const void *addr) > +{ > + return reset_tag(addr); > +} > + To help readability, would this edit be ok? ------ void kasan_poison_memory(const void *address, size_t size, u8 value) { - set_mem_tag_range(reset_tag(address), - round_up(size, KASAN_GRANULE_SIZE), value); + set_mem_tag_range(reset_tag(address), round_up(size, KASAN_GRANULE_SIZE), value); } void kasan_unpoison_memory(const void *address, size_t size) { - set_mem_tag_range(reset_tag(address), - round_up(size, KASAN_GRANULE_SIZE), get_tag(address)); + set_mem_tag_range(reset_tag(address), round_up(size, KASAN_GRANULE_SIZE), get_tag(address)); } ------ > +void kasan_poison_memory(const void *address, size_t size, u8 value) > +{ > + set_mem_tag_range(reset_tag(address), > + round_up(size, KASAN_GRANULE_SIZE), value); > +} > + > +void kasan_unpoison_memory(const void *address, size_t size) > +{ > + set_mem_tag_range(reset_tag(address), > + round_up(size, KASAN_GRANULE_SIZE), get_tag(address)); > +} > + > +u8 random_tag(void) > +{ > + return get_random_tag(); > +} > + > +bool check_invalid_free(void *addr) > +{ > + u8 ptr_tag = get_tag(addr); > + u8 mem_tag = get_mem_tag(addr); > + Why not just: ------ - if (shadow_byte == KASAN_TAG_INVALID) - return true; - if (tag != KASAN_TAG_KERNEL && tag != shadow_byte) - return true; - return false; + return shadow_byte == KASAN_TAG_INVALID || + (tag != KASAN_TAG_KERNEL && tag != shadow_byte); } ------ > + if (mem_tag == KASAN_TAG_INVALID) > + return true; > + if (ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag) > + return true; > + return false; > +} > + Thanks, -- Marco