Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH 3/5] mm: gup: remove useless BUG_ON in __get_user_pages()
To:     Miaohe Lin <linmiaohe@huawei.com>, akpm@linux-foundation.org
Cc:     imbrenda@linux.ibm.com, kirill.shutemov@linux.intel.com,
        jack@suse.cz, jhubbard@nvidia.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20210807093620.21347-1-linmiaohe@huawei.com>
 <20210807093620.21347-4-linmiaohe@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
Message-ID: <bc5fc4a9-dcb1-c79b-9a7a-0375b7c2ec7e@redhat.com>
Date:   Mon, 9 Aug 2021 11:23:25 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <20210807093620.21347-4-linmiaohe@huawei.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 07.08.21 11:36, Miaohe Lin wrote:
> Indeed, this BUG_ON couldn't catch anything useful. We are sure ret == 0
> here because we would already bail out if ret != 0 and ret is untouched
> till here.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>   mm/gup.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index d6056dcab02c..d7e4507de6b1 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1149,7 +1149,6 @@ static long __get_user_pages(struct mm_struct *mm,
>   					 * We must stop here.
>   					 */
>   					BUG_ON(gup_flags & FOLL_NOWAIT);
> -					BUG_ON(ret != 0);
>   					goto out;
>   				}
>   				continue;
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb