From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757387AbcJQB7Z (ORCPT ); Sun, 16 Oct 2016 21:59:25 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:63983 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756519AbcJQB7U (ORCPT ); Sun, 16 Oct 2016 21:59:20 -0400 Message-ID: <5804305F.4030302@huawei.com> Date: Mon, 17 Oct 2016 09:58:55 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: , , , , , , CC: , Subject: Re: [PATCH v2] z3fold: fix the potential encode bug in encod_handle References: <1476331337-17253-1-git-send-email-zhongjiang@huawei.com> In-Reply-To: <1476331337-17253-1-git-send-email-zhongjiang@huawei.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Vitaly About the following patch, is it right? Thanks zhongjiang On 2016/10/13 12:02, zhongjiang wrote: > From: zhong jiang > > At present, zhdr->first_num plus bud can exceed the BUDDY_MASK > in encode_handle, it will lead to the the caller handle_to_buddy > return the error value. > > The patch fix the issue by changing the BUDDY_MASK to PAGE_MASK, > it will be consistent with handle_to_z3fold_header. At the same time, > change the BUDDY_MASK to PAGE_MASK in handle_to_buddy is better. > > Signed-off-by: zhong jiang > --- > mm/z3fold.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/z3fold.c b/mm/z3fold.c > index 8f9e89c..e8fc216 100644 > --- a/mm/z3fold.c > +++ b/mm/z3fold.c > @@ -169,7 +169,7 @@ static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud) > > handle = (unsigned long)zhdr; > if (bud != HEADLESS) > - handle += (bud + zhdr->first_num) & BUDDY_MASK; > + handle += (bud + zhdr->first_num) & PAGE_MASK; > return handle; > } > > @@ -183,7 +183,7 @@ static struct z3fold_header *handle_to_z3fold_header(unsigned long handle) > static enum buddy handle_to_buddy(unsigned long handle) > { > struct z3fold_header *zhdr = handle_to_z3fold_header(handle); > - return (handle - zhdr->first_num) & BUDDY_MASK; > + return (handle - zhdr->first_num) & PAGE_MASK; > } > > /*