[PATCH] Fix tty layer DoS and comment relevant code
Unlike the other tty comment patch this one has code changes. Specifically
it limits the queue size for a tty to 64K characters (128Kbytes) worst case
even if the tty is ignoring tty->throttle. This is because certain drivers
don't honour the throttle value correctly, although it is a useful
safeguard anyway.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/tty.h b/include/linux/tty.h
index e421d5e..04827ca 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -59,6 +59,7 @@
struct tty_buffer *head; /* Queue head */
struct tty_buffer *tail; /* Active buffer */
struct tty_buffer *free; /* Free queue head */
+ int memory_used; /* Buffer space used excluding free queue */
};
/*
* The pty uses char_buf and flag_buf as a contiguous buffer