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 D1EAFC433F5 for ; Tue, 12 Apr 2022 12:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240228AbiDLMdc (ORCPT ); Tue, 12 Apr 2022 08:33:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352593AbiDLMdQ (ORCPT ); Tue, 12 Apr 2022 08:33:16 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81FC5D77 for ; Tue, 12 Apr 2022 04:50:41 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Kd3tj1KKKzdZLZ; Tue, 12 Apr 2022 19:50:05 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 12 Apr 2022 19:50:39 +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_CBC_SHA256) id 15.1.2375.24; Tue, 12 Apr 2022 19:50:39 +0800 Message-ID: Date: Tue, 12 Apr 2022 19:50:38 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [RFC PATCH -next V3 2/6] arm64: fix types in copy_highpage() Content-Language: en-US To: Tong Tiangen , Mark Rutland , James Morse , Andrew Morton , Thomas Gleixner , "Ingo Molnar" , Borislav Petkov , Robin Murphy , Dave Hansen , "Catalin Marinas" , Will Deacon , "Alexander Viro" , , "H . Peter Anvin" CC: , , , Xie XiuQi References: <20220412072552.2526871-1-tongtiangen@huawei.com> <20220412072552.2526871-3-tongtiangen@huawei.com> From: Kefeng Wang In-Reply-To: <20220412072552.2526871-3-tongtiangen@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggeme707-chm.china.huawei.com (10.1.199.103) 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 2022/4/12 15:25, Tong Tiangen wrote: > In copy_highpage() the `kto` and `kfrom` local variables are pointers to > struct page, but these are used to hold arbitrary pointers to kernel memory > . Each call to page_address() returns a void pointer to memory associated > with the relevant page, and copy_page() expects void pointers to this > memory. > > This inconsistency was introduced in commit 2563776b41c3 ("arm64: mte: > Tags-aware copy_{user_,}highpage() implementations") and while this > doesn't appear to be harmful in practice it is clearly wrong. > > Correct this by making `kto` and `kfrom` void pointers. Reviewed-by: Kefeng Wang > Fixes: 2563776b41c3 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations") > Signed-off-by: Tong Tiangen > Acked-by: Mark Rutland > --- > arch/arm64/mm/copypage.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c > index b5447e53cd73..0dea80bf6de4 100644 > --- a/arch/arm64/mm/copypage.c > +++ b/arch/arm64/mm/copypage.c > @@ -16,8 +16,8 @@ > > void copy_highpage(struct page *to, struct page *from) > { > - struct page *kto = page_address(to); > - struct page *kfrom = page_address(from); > + void *kto = page_address(to); > + void *kfrom = page_address(from); > > copy_page(kto, kfrom); >