commit 28a821c306889b9f2c3fff49abedc9b2c743eb73 upstream. This function is largely a duplicate of paste_selection() in drivers/tty/vt/selection.c, but with its own selection state. The speakup selection mechanism should really be merged with vt. For now, apply the changes from 'TTY: vt, fix paste_selection ldisc handling', 'tty: Make ldisc input flow control concurrency-friendly', and 'tty: Fix unsafe vt paste_selection()'. References: https://bugs.debian.org/735202 References: https://bugs.debian.org/744015 Reported-by: Paul Gevers <elbrus@xxxxxxxxxx> Reported-and-tested-by: Jarek Czekalski <jarekczek@xxxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.10: - Only apply the changes from 'TTY: vt, fix paste_selection ldisc handling' - Add the same FIXME comment as vt's paste_selection() has in this version] --- drivers/staging/speakup/selection.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c index f67941e..b935975 100644 --- a/drivers/staging/speakup/selection.c +++ b/drivers/staging/speakup/selection.c @@ -5,6 +5,7 @@ #include <linux/device.h> /* for dev_warn */ #include <linux/selection.h> #include <linux/workqueue.h> +#include <linux/tty.h> #include <asm/cmpxchg.h> #include "speakup.h" @@ -135,8 +136,12 @@ static void __speakup_paste_selection(struct work_struct *work) struct tty_struct *tty = xchg(&spw->tty, NULL); struct vc_data *vc = (struct vc_data *) tty->driver_data; int pasted = 0, count; + struct tty_ldisc *ld; DECLARE_WAITQUEUE(wait, current); + ld = tty_ldisc_ref_wait(tty); + + /* FIXME: this is completely unsafe */ add_wait_queue(&vc->paste_wait, &wait); while (sel_buffer && sel_buffer_lth > pasted) { set_current_state(TASK_INTERRUPTIBLE); @@ -146,12 +151,13 @@ static void __speakup_paste_selection(struct work_struct *work) } count = sel_buffer_lth - pasted; count = min_t(int, count, tty->receive_room); - tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted, - NULL, count); + ld->ops->receive_buf(tty, sel_buffer + pasted, NULL, count); pasted += count; } remove_wait_queue(&vc->paste_wait, &wait); current->state = TASK_RUNNING; + + tty_ldisc_deref(ld); tty_kref_put(tty); } -- Ben Hutchings In a hierarchy, every employee tends to rise to his level of incompetence.
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