From: WANG Cong <xiyou.wangcong@gmail.com>
To: Jeff Dike <jdike@addtoit.com>
Cc: akpm@osdl.org, WANG Cong <xiyou.wangcong@gmail.com>,
linux-kernel@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] [PATCH 6/19] UML - hppfs fixes
Date: Tue, 29 Apr 2008 16:04:56 +0800 (CST) [thread overview]
Message-ID: <alpine.LFD.1.00.0804291604380.2548@localhost.localdomain> (raw)
In-Reply-To: <20080428152940.GA7465@c2.user-mode-linux.org>
On Mon, 28 Apr 2008, Jeff Dike wrote:
> On Sat, Apr 26, 2008 at 04:31:32PM +0800, WANG Cong wrote:
>> > + rem = copy_to_user(buf, &data->contents[off], count);
>> > + *ppos += count - rem;
>> > + if (rem > 0)
>> > + return -EFAULT;
>>
>> Could you please explain why check 'rem' after using it here?
>
> Actually, this isn't as wrong as it looks. copy_to_user returns what
> hasn't been copied (rem == remaining). So, I think the mistake is to
> return -EFAULT here. Returning the short count would be right, unless
> rem == count, in which case we return -EFAULT.
Yes, thanks.
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prev parent reply other threads:[~2008-04-29 8:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-25 17:56 [uml-devel] [PATCH 6/19] UML - hppfs fixes Jeff Dike
2008-04-26 8:31 ` WANG Cong
2008-04-28 15:16 ` Jeff Dike
2008-04-28 15:29 ` Jeff Dike
2008-04-29 8:04 ` WANG Cong [this message]
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