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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57348C433EF for ; Tue, 12 Apr 2022 11:50:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F7066B0082; Tue, 12 Apr 2022 07:50:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A6BD6B0083; Tue, 12 Apr 2022 07:50:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 895E46B0085; Tue, 12 Apr 2022 07:50:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0171.hostedemail.com [216.40.44.171]) by kanga.kvack.org (Postfix) with ESMTP id 76E346B0082 for ; Tue, 12 Apr 2022 07:50:43 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 34AD41838DC1E for ; Tue, 12 Apr 2022 11:50:43 +0000 (UTC) X-FDA: 79348059966.23.17FD12B Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf14.hostedemail.com (Postfix) with ESMTP id 83094100004 for ; Tue, 12 Apr 2022 11:50:42 +0000 (UTC) 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 X-Rspam-User: Authentication-Results: imf14.hostedemail.com; dkim=none; spf=pass (imf14.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 83094100004 X-Stat-Signature: imuy8fichxc44qbtgks975iysemfpgyk X-HE-Tag: 1649764242-810830 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: 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); >