tty: Fix unsafe vt paste_selection()
Convert the tty_buffer_flush() exclusion mechanism to a
public interface - tty_buffer_lock/unlock_exclusive() - and use
the interface to safely write the paste selection to the line
discipline.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 2ca8d6b..ea27804 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -24,6 +24,7 @@
#include <linux/selection.h>
#include <linux/tiocl.h>
#include <linux/console.h>
+#include <linux/tty_flip.h>
/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
#define isspace(c) ((c) == ' ')
@@ -346,8 +347,8 @@
console_unlock();
ld = tty_ldisc_ref_wait(tty);
+ tty_buffer_lock_exclusive(&vc->port);
- /* FIXME: this is completely unsafe */
add_wait_queue(&vc->paste_wait, &wait);
while (sel_buffer && sel_buffer_lth > pasted) {
set_current_state(TASK_INTERRUPTIBLE);
@@ -363,6 +364,7 @@
remove_wait_queue(&vc->paste_wait, &wait);
__set_current_state(TASK_RUNNING);
+ tty_buffer_unlock_exclusive(&vc->port);
tty_ldisc_deref(ld);
return 0;
}