Messages in this thread | | | Date | Wed, 05 Dec 2012 12:47:54 +0400 | From | Ilya Zykov <> | Subject | [PATCH -next 0/2] tty: Correct tty buffer flush. |
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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@ilyx.ru>
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