[PATCH 3.14 49/78] Staging: speakup: Update __speakup_paste_selection() tty (ab)usage to match vt

Greg Kroah-Hartman
2014-06-09T23:02:49Z

From: Ben Hutchings <ben@decadent.org.uk>

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@debian.org>
Reported-and-tested-by: Jarek Czekalski <jarekczek@poczta.onet.pl>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/speakup/selection.c | 14 +++++++++++---
drivers/tty/tty_buffer.c | 2 ++
2 files changed, 13 insertions(+), 3 deletions(-)

--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -5,6 +5,8 @@
#include <linux/device.h> /* for dev_warn */
#include <linux/selection.h>
#include <linux/workqueue.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
#include <asm/cmpxchg.h>

#include "speakup.h"
@@ -135,8 +137,12 @@ static void __speakup_paste_selection(st
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);
+ tty_buffer_lock_exclusive(&vc->port);
+
add_wait_queue(&vc->paste_wait, &wait);
while (sel_buffer && sel_buffer_lth > pasted) {
set_current_state(TASK_INTERRUPTIBLE);
@@ -145,13 +151,15 @@ static void __speakup_paste_selection(st
continue;
}
count = sel_buffer_lth - pasted;
- count = min_t(int, count, tty->receive_room);
- tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
- NULL, count);
+ count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
+ count);
pasted += count;
}
remove_wait_queue(&vc->paste_wait, &wait);
current->state = TASK_RUNNING;
+
+ tty_buffer_unlock_exclusive(&vc->port);
+ tty_ldisc_deref(ld);
tty_kref_put(tty);
}

--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -60,6 +60,7 @@ void tty_buffer_lock_exclusive(struct tt
atomic_inc(&buf->priority);
mutex_lock(&buf->lock);
}
+EXPORT_SYMBOL_GPL(tty_buffer_lock_exclusive);

void tty_buffer_unlock_exclusive(struct tty_port *port)
{
@@ -73,6 +74,7 @@ void tty_buffer_unlock_exclusive(struct
if (restart)
queue_work(system_unbound_wq, &buf->work);
}
+EXPORT_SYMBOL_GPL(tty_buffer_unlock_exclusive);

/**
* tty_buffer_space_avail - return unused buffer space