Re: [PATCH] reduce stack in cpqarray.c::ida_ioctl()

Jens Axboe (axboe@suse.de)
Fri, 4 Apr 2003 10:09:37 +0200


On Fri, Apr 04 2003, Jörn Engel wrote:
> > + error = copy_to_user(io, my_io, sizeof(*my_io)) ? -EFAULT : 0;
>
> copy_to_user returns the bytes successfully copied.
> error is set to -EFAULT, if there was actually data transferred?
>
> How about:
> + error = copy_to_user(io, my_io, sizeof(*my_io)) < sizeof(*my_io) ? -EFAULT : 0;

Pure nonsense! Correct logic, and much nicer to read IMO is:

if (copy_to_user(io, my_io, sizeof(*my_io))
error = -EFAULT;

-- 
Jens Axboe

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