Re: EFAULT from file read.

[Alexander Viro]

On Tue, 18 Sep 2001, Richard B. Johnson wrote:

> File I/O requires a process context. Your file descriptor means
> nothing unless associated with the process that opened the file.

It fscking doesn't.  He had clearly said that he calls file->f_op->read(),
which has nothing whatsofuckingever to descriptors.  Sod off and don't
return until you learn to read.

As for the original question - grep fro set_fs and you'll see what to
do (basically, set_fs(KERNEL_DS) before the call of ->read() and restore
afterwards).