From f4f9edcf9b5289ed96113e79fa65a7bf27ecb096 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sun, 10 Jan 2016 22:40:58 -0800 Subject: [PATCH] staging/speakup: Use tty_ldisc_ref() for paste kworker As the function documentation for tty_ldisc_ref_wait() notes, it is only callable from a tty file_operations routine; otherwise there is no guarantee the ref won't be NULL. The key difference with the VT's paste_selection() is that is an ioctl, where __speakup_paste_selection() is completely async kworker, kicked off from interrupt context. Fixes: 28a821c30688 ("Staging: speakup: Update __speakup_paste_selection() tty (ab)usage to match vt") Cc: Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/staging/speakup/selection.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c index aa5ab6c80ed4..41ef099b7aa6 100644 --- a/drivers/staging/speakup/selection.c +++ b/drivers/staging/speakup/selection.c @@ -142,7 +142,9 @@ static void __speakup_paste_selection(struct work_struct *work) struct tty_ldisc *ld; DECLARE_WAITQUEUE(wait, current); - ld = tty_ldisc_ref_wait(tty); + ld = tty_ldisc_ref(tty); + if (!ld) + goto tty_unref; tty_buffer_lock_exclusive(&vc->port); add_wait_queue(&vc->paste_wait, &wait); @@ -162,6 +164,7 @@ static void __speakup_paste_selection(struct work_struct *work) tty_buffer_unlock_exclusive(&vc->port); tty_ldisc_deref(ld); +tty_unref: tty_kref_put(tty); } -- 2.20.1