From: Wei Yang <richard.weiyang@gmail.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Wei Yang <richard.weiyang@gmail.com>,
akpm@linux-foundation.org, mhocko@suse.com, linux-mm@kvack.org
Subject: Re: [PATCH] mm: remove a redundant check in do_munmap()
Date: Wed, 10 Oct 2018 15:19:11 +0000 [thread overview]
Message-ID: <20181010151911.uslsfmr5wa3ujdwi@master> (raw)
In-Reply-To: <20181010141320.zxic4ryuzo63utom@kshutemo-mobl1>
On Wed, Oct 10, 2018 at 05:13:20PM +0300, Kirill A. Shutemov wrote:
>On Wed, Oct 10, 2018 at 08:53:27PM +0800, Wei Yang wrote:
>> A non-NULL vma returned from find_vma() implies:
>>
>> vma->vm_start <= start
>> Since len != 0, the following condition always hods:
>
>s/hods/holds/
>
>> vma->vm_start < start + len = end
>>
>> This means the if check would never be true.
>
>Have you considered overflow?
>
Thanks for your comment.
At the beginning of this function, we make sure (len <= TASK_SIZE - start).
--
Wei Yang
Help you, Help me
next prev parent reply other threads:[~2018-10-10 15:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-10 12:53 Wei Yang
2018-10-10 14:13 ` Kirill A. Shutemov
2018-10-10 15:19 ` Wei Yang [this message]
2018-10-10 14:13 ` Matthew Wilcox
2018-10-10 15:23 ` Wei Yang
2018-10-16 6:24 ` Wei Yang
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