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

[Alan Cox]

On Tue, 04 Dec 2012 17:10:57 +0400
Ilya Zykov <ilya@xxxxxxx> 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(tty->buf.head->read = tty->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.
> 
> Signed-off-by: Ilya Zykov <ilya@xxxxxxx>

Acked-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/