Re: [PATCH] tty: Correct tty buffer flush.

Greg Kroah-Hartman
2013-01-19T00:07:08Z

On Wed, Jan 16, 2013 at 12:55:00PM +0400, Ilya Zykov wrote:
> The root of problem is carelessly zeroing pointer(in function __tty_buffer_flush()),
> when another thread can use it. It can be cause of "NULL pointer dereference".
> Main idea of the patch, this is never free last (struct tty_buffer) in the active buffer.
> Only flush the data for ldisc(buf->head->read = buf->head->commit).
> At that moment driver can collect(write) data in buffer without conflict.
> It is repeat behavior of flush_to_ldisc(), only without feeding data to ldisc.
>
> Also revert:
> commit c56a00a165712fd73081f40044b1e64407bb1875
> tty: hold lock across tty buffer finding and buffer filling
> In order to delete the unneeded locks any more.

This patch doesn't apply to my tty-next branch, can you redo it against
linux-next so that I can apply it?

thanks,

greg k-h