From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hugh Dickins Date: Sat, 14 Jan 2017 00:02:37 +0000 Subject: Re: [patch v2 linux-next] userfaultfd: hugetlbfs: unmap the correct pointer Message-Id: List-Id: References: <20170113082608.GA3548@mwanda> In-Reply-To: <20170113082608.GA3548@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Andrew Morton , Mike Kravetz , "Kirill A. Shutemov" , Jan Kara , Ross Zwisler , Michal Hocko , Lorenzo Stoakes , Dan Williams , "Aneesh Kumar K.V" , linux-mm@kvack.org, kernel-janitors@vger.kernel.org On Fri, 13 Jan 2017, Dan Carpenter wrote: > kunmap_atomic() and kunmap() take different pointers. People often get > these mixed up. > > Fixes: 16374db2e9a0 ("userfaultfd: hugetlbfs: fix __mcopy_atomic_hugetlb retry/error processing") > Signed-off-by: Dan Carpenter > --- > v2: I was also unmapping the wrong pointer because I had a typo. > > diff --git a/mm/memory.c b/mm/memory.c > index 6012a05..aca8ef6 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -4172,7 +4172,7 @@ long copy_huge_page_from_user(struct page *dst_page, > (const void __user *)(src + i * PAGE_SIZE), > PAGE_SIZE); > if (allow_pagefault) > - kunmap(page_kaddr); > + kunmap(page_kaddr + i); > else > kunmap_atomic(page_kaddr); I think you need to look at that again. Hugh From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 90D846B0033 for ; Fri, 13 Jan 2017 19:02:46 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id 203so78144190ith.3 for ; Fri, 13 Jan 2017 16:02:46 -0800 (PST) Received: from mail-pf0-x22e.google.com (mail-pf0-x22e.google.com. [2607:f8b0:400e:c00::22e]) by mx.google.com with ESMTPS id r21si14102700pgg.64.2017.01.13.16.02.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Jan 2017 16:02:45 -0800 (PST) Received: by mail-pf0-x22e.google.com with SMTP id y143so38324843pfb.0 for ; Fri, 13 Jan 2017 16:02:45 -0800 (PST) Date: Fri, 13 Jan 2017 16:02:37 -0800 (PST) From: Hugh Dickins Subject: Re: [patch v2 linux-next] userfaultfd: hugetlbfs: unmap the correct pointer In-Reply-To: <20170113082608.GA3548@mwanda> Message-ID: References: <20170113082608.GA3548@mwanda> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dan Carpenter Cc: Andrew Morton , Mike Kravetz , "Kirill A. Shutemov" , Jan Kara , Ross Zwisler , Michal Hocko , Lorenzo Stoakes , Dan Williams , "Aneesh Kumar K.V" , linux-mm@kvack.org, kernel-janitors@vger.kernel.org On Fri, 13 Jan 2017, Dan Carpenter wrote: > kunmap_atomic() and kunmap() take different pointers. People often get > these mixed up. > > Fixes: 16374db2e9a0 ("userfaultfd: hugetlbfs: fix __mcopy_atomic_hugetlb retry/error processing") > Signed-off-by: Dan Carpenter > --- > v2: I was also unmapping the wrong pointer because I had a typo. > > diff --git a/mm/memory.c b/mm/memory.c > index 6012a05..aca8ef6 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -4172,7 +4172,7 @@ long copy_huge_page_from_user(struct page *dst_page, > (const void __user *)(src + i * PAGE_SIZE), > PAGE_SIZE); > if (allow_pagefault) > - kunmap(page_kaddr); > + kunmap(page_kaddr + i); > else > kunmap_atomic(page_kaddr); I think you need to look at that again. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org