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From: LA Walsh <law@sgi.com>
To: linux-kernel@vger.kernel.org
Subject: Block driver design issue
Date: Mon, 12 Feb 2001 09:16:02 -0800	[thread overview]
Message-ID: <3A881A52.962B3ED4@sgi.com> (raw)

I have a block driver I inherited that I working on that has a problem and
was wondering for cleaner solutions.

The driver can accept written characters from either userspace programs or from
the kernel.  From userspace it uses sys_write.  That in turn calls block_write.
There's almost 100 lines of duplicated code in a copy of the block_write
code in the driver "block_writek" as well as duplicate code in audit_write vs. audit_writek.
The only difference being down in block_write at the "copy_from_user(p,buf,chars); "
which becomes a "memcpy(p,buf,chars)" in the "block_writek" version.  

I find this duplication of code to be inefficient.  Is there a way to dummy up the
the 'buf' address so that the "copy_from_user" will copy the buffer from kernel space?
My assumption is that it wouldn't "just work" (which may also be an invalid assumption).

Suggestions?  Abuse?

Thanks!
-linda

-- 
L A Walsh                    | Trust Technology, Core Linux, SGI
law@sgi.com                      | Voice: (650) 933-5338
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             reply	other threads:[~2001-02-12 17:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-02-12 17:16 LA Walsh [this message]
2001-02-12 17:30 ` Block driver design issue Manfred Spraul

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