Re: [PATCH 2.4] i2c-dev user/kernel bug and mem leak

["Robert T. Johnson" <rtjohnso@eecs.berkeley.edu>]

On Fri, 2003-08-15 at 16:51, Greg KH wrote:
> On Fri, Aug 15, 2003 at 03:17:25PM -0700, Robert T. Johnson wrote:
> > For this particular bug (before all the patches started flying around),
> > you'd have to add a kernel annotation to the "struct i2c_msg" field
> > buf.
> 
> Look at 2.6, that annotatation is already there.

I just double-checked my copy of linux-2.6.0-test3, and I don't see it. 
Just to make sure we're talking about the same thing, I'm looking at
include/linux/i2c.h:402, i.e. the definition of field buf in struct
i2c_msg.

Now I see you have the msgs field of i2c_rdwr_ioctl_arg annotated as
__user.  That should've generated a warning from sparse.  Looks like a
bug in sparse to me.

> Nice, is cqual released somewhere so that we can compare it and start
> using it, like we already use sparse?

I just discussed it with the other developers, and we'll work on getting
a release out in the next week or so.  It still has rough edges, but
feedback from kernel developers like yourself will be invaluable.

> Yes it is, one of the paramaters in those functions is the size of the
> buffer :)

Oh.  Now I'm sold on your solution.  Thanks for pointing that out.

Best,
Rob