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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 D7439C4338F for ; Mon, 9 Aug 2021 11:10:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B721C60EBB for ; Mon, 9 Aug 2021 11:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234649AbhHILKf (ORCPT ); Mon, 9 Aug 2021 07:10:35 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:16998 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233516AbhHILKe (ORCPT ); Mon, 9 Aug 2021 07:10:34 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GjtZ11gHqzb06D; Mon, 9 Aug 2021 19:06:33 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 9 Aug 2021 19:10:10 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 9 Aug 2021 19:10:10 +0800 Subject: Re: [PATCH v3 3/3] kasan: arm64: Fix pcpu_page_first_chunk crash with KASAN_VMALLOC To: , , , , , , CC: , , References: <20210809093750.131091-1-wangkefeng.wang@huawei.com> <20210809093750.131091-4-wangkefeng.wang@huawei.com> From: Kefeng Wang Message-ID: Date: Mon, 9 Aug 2021 19:10:09 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210809093750.131091-4-wangkefeng.wang@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/8/9 17:37, Kefeng Wang wrote: > With KASAN_VMALLOC and NEED_PER_CPU_PAGE_FIRST_CHUNK, it crashs, > > Unable to handle kernel paging request at virtual address ffff7000028f2000 > ... > swapper pgtable: 64k pages, 48-bit VAs, pgdp=0000000042440000 > [ffff7000028f2000] pgd=000000063e7c0003, p4d=000000063e7c0003, pud=000000063e7c0003, pmd=000000063e7b0003, pte=0000000000000000 > Internal error: Oops: 96000007 [#1] PREEMPT SMP > Modules linked in: > CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.0-rc4-00003-gc6e6e28f3f30-dirty #62 > Hardware name: linux,dummy-virt (DT) > pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO BTYPE=--) > pc : kasan_check_range+0x90/0x1a0 > lr : memcpy+0x88/0xf4 > sp : ffff80001378fe20 > ... > Call trace: > kasan_check_range+0x90/0x1a0 > pcpu_page_first_chunk+0x3f0/0x568 > setup_per_cpu_areas+0xb8/0x184 > start_kernel+0x8c/0x328 > > The vm area used in vm_area_register_early() has no kasan shadow memory, > Let's add a new kasan_populate_early_vm_area_shadow() function to populate > the vm area shadow memory to fix the issue. Should add Acked-by: Marco Elver [for KASAN parts] , missed here :( > Signed-off-by: Kefeng Wang > --- > arch/arm64/mm/kasan_init.c | 16 ++++++++++++++++ > include/linux/kasan.h | 6 ++++++ > mm/kasan/init.c | 5 +++++ > mm/vmalloc.c | 1 + > 4 files changed, 28 insertions(+) > > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c > index 61b52a92b8b6..5b996ca4d996 100644 > --- a/arch/arm64/mm/kasan_init.c > +++ b/arch/arm64/mm/kasan_init.c > @@ -287,6 +287,22 @@ static void __init kasan_init_depth(void) > init_task.kasan_depth = 0; > } > > +#ifdef CONFIG_KASAN_VMALLOC > +void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size) > +{ > + unsigned long shadow_start, shadow_end; > + > + if (!is_vmalloc_or_module_addr(start)) > + return; > + > + shadow_start = (unsigned long)kasan_mem_to_shadow(start); > + shadow_start = ALIGN_DOWN(shadow_start, PAGE_SIZE); > + shadow_end = (unsigned long)kasan_mem_to_shadow(start + size); > + shadow_end = ALIGN(shadow_end, PAGE_SIZE); > + kasan_map_populate(shadow_start, shadow_end, NUMA_NO_NODE); > +} > +#endif > + > void __init kasan_init(void) > { > kasan_init_shadow(); > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index dd874a1ee862..3f8c26d9ef82 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -133,6 +133,8 @@ struct kasan_cache { > bool is_kmalloc; > }; > > +void kasan_populate_early_vm_area_shadow(void *start, unsigned long size); > + > slab_flags_t __kasan_never_merge(void); > static __always_inline slab_flags_t kasan_never_merge(void) > { > @@ -303,6 +305,10 @@ void kasan_restore_multi_shot(bool enabled); > > #else /* CONFIG_KASAN */ > > +static inline void kasan_populate_early_vm_area_shadow(void *start, > + unsigned long size) > +{ } > + > static inline slab_flags_t kasan_never_merge(void) > { > return 0; > diff --git a/mm/kasan/init.c b/mm/kasan/init.c > index cc64ed6858c6..d39577d088a1 100644 > --- a/mm/kasan/init.c > +++ b/mm/kasan/init.c > @@ -279,6 +279,11 @@ int __ref kasan_populate_early_shadow(const void *shadow_start, > return 0; > } > > +void __init __weak kasan_populate_early_vm_area_shadow(void *start, > + unsigned long size) > +{ > +} > + > static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd) > { > pte_t *pte; > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 1e8fe08725b8..66a7e1ea2561 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2253,6 +2253,7 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align) > vm->addr = (void *)addr; > > vm_area_add_early(vm); > + kasan_populate_early_vm_area_shadow(vm->addr, vm->size); > } > > static void vmap_init_free_space(void)