From: Jens Axboe <axboe@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Jesper Juhl <juhl-lkml@dif.dk>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] remember to check return value from __copy_to_user() in cdrom_read_cdda_old()
Date: Tue, 7 Sep 2004 11:34:37 +0200 [thread overview]
Message-ID: <20040907093437.GK6323@suse.de> (raw)
In-Reply-To: <16701.32784.10441.884090@cargo.ozlabs.ibm.com>
On Tue, Sep 07 2004, Paul Mackerras wrote:
> Jens Axboe writes:
>
> > __copy_to_user is the unchecking version of copy_to_user.
>
> It doesn't range-check the address, but it does return non-zero
> (number of bytes not copied) if it encounters a fault writing to the
> user buffer.
but it doesn't matter, if it returns non-zero then something happened
between the access_ok() and the actual copy because the user app did
something silly. so I don't care much really, I think the major point is
the kernel will cope.
you could remove the access_ok() and change it to a copy_to_user()
instead, I don't care either way. it's the old and slow interface which
really never is used unless things have gone wrong anyways.
--
Jens Axboe
next prev parent reply other threads:[~2004-09-07 9:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-06 21:46 [PATCH] remember to check return value from __copy_to_user() in cdrom_read_cdda_old() Jesper Juhl
2004-09-07 8:02 ` Jens Axboe
2004-09-07 9:32 ` Paul Mackerras
2004-09-07 9:34 ` Jens Axboe [this message]
2004-09-07 9:59 ` Andrew Morton
2004-09-07 10:09 ` Jens Axboe
2004-09-07 10:12 ` Andrew Morton
2004-09-07 10:15 ` Jens Axboe
2004-09-07 10:23 ` viro
2004-09-07 10:30 ` Jens Axboe
2004-09-07 10:45 ` viro
2004-09-07 11:42 ` Jens Axboe
2004-09-07 9:58 ` Jens Axboe
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