From: Ilya Zykov Date: Mon, 4 Mar 2013 19:19:41 +0000 (+0400) Subject: tty: Correct tty buffer flush. X-Git-Tag: v3.2.41~45 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=689901ce9cedd2d34a5404dda146d0604cbc2a5e;p=pandora-kernel.git tty: Correct tty buffer flush. commit 64325a3be08d364a62ee8f84b2cf86934bc2544a upstream. 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. Signed-off-by: Ilya Zykov Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed