Message-ID: <4C079D34.5010500@oss.ntt.co.jp>
Date: Thu, 03 Jun 2010 21:16:52 +0900
From: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
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To: Jens Axboe <jaxboe@fusionio.com>
CC: Dan Carpenter <error27@gmail.com>, Matthew Wilcox <matthew@wil.cx>,
       Alexander Viro <viro@zeniv.linux.org.uk>,
       Andrew Morton <akpm@linux-foundation.org>,
       Oleg Nesterov <oleg@redhat.com>, Greg Kroah-Hartman <gregkh@suse.de>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-fsdevel@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [patch v2] fcntl: return -EFAULT if copy_to_user fails
References: <20100603100402.GR5483@bicker> <4C07826A.6060302@oss.ntt.co.jp> <20100603103542.GV5483@bicker> <4C07990A.8080508@fusionio.com>
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(2010/06/03 20:59), Jens Axboe wrote:
> On 2010-06-03 12:35, Dan Carpenter wrote:
>> copy_to_user() returns the number of bytes remaining, but we want to
>> return -EFAULT.
>> 	ret = fcntl(fd, F_SETOWN_EX, NULL);
>> With the original code ret would be 8 here.
>>
>> V2: Takuya Yoshikawa pointed out a similar issue in f_getown_ex()
>
> Pretty basic bug, how long has this been there?

IIUC, from the beginning, when these were introduced.

And I recently sent similar bug fixes for other parts.

Ah, I also saw somebody sent cleanup patches using memdup_user() which does
not reside in uaccess.h.

Though I'm personally using private *_user documentation,
are there any good official doc for these?

   Takuya


>
> Acked-by: Jens Axboe<jaxboe@fusionio.com>
>

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