From: Ilya Zykov <ilya@ilyx.ru>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Cox <alan@linux.intel.com>, Jiri Slaby <jslaby@suse.cz>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: [PATCH -next 0/2] tty: Correct tty buffer flush.
Date: Wed, 05 Dec 2012 12:47:54 +0400 [thread overview]
Message-ID: <50BF0A3A.1090801@ilyx.ru> (raw)
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>
reply other threads:[~2012-12-05 8:47 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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