Re: Infinite loop with d_write_t

On Sun, Mar 19, 2023 at 6:33 AM Yuri <yuri@aetern.org> wrote:
>
> Goran Mekić wrote:
> > Hello,
> >
> > I'm trying to assemble a minimal kernel module and user space program as
> > a skeleton, and no matter what I do I get infinite loop. The code for
> > kernel is https://github.com/mekanix/freebsd-project/blob/master/kernel/main.c.
> > The way to test:
> > # make
> > # sudo kldload ./hello.ko
> > # echo "something" >/dev/hello
> > Write done.
> > Write done.
> > ...
> >
> > What am I doing wrong and where does that infinite loop comes from?
>
> Why are you using copyin() and not uiomove() in d_write entry?
>
> There's an example that looks like you are trying to do:
>
> https://docs.freebsd.org/en/books/arch-handbook/driverbasics/#driverbasics-char
>

This... d_write/d_read need the uio accounting updated to reflect how
much data was written/read, it doesn't want to assume you were able to
do everything in a single call.

Thanks,

Kyle Evans