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Commit 0ad7c9af authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
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Char: moxa, fix locking in moxa_write 



moxa_write can be called from atomic context with irqs disabled (from
ppp_async_push). Don't enable interrupts by spin_unlock_bh as this
might cause deadlocks in the ppp layer.

Instead, use irqsave/irqrestore spin_lock functions.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7fdc2893

drivers/tty/moxa.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -1202,14 +1202,15 @@ static int moxa_write(struct tty_struct *tty, 
		      const unsigned char *buf, int count)

		      const unsigned char *buf, int count)

{

{

	struct moxa_port *ch = tty->driver_data;

	struct moxa_port *ch = tty->driver_data;

	unsigned long flags;

	int len;

	int len;





	if (ch == NULL)

	if (ch == NULL)

		return 0;

		return 0;





	spin_lock_bh(&moxa_lock);

	spin_lock_irqsave(&moxa_lock, flags);

	len = MoxaPortWriteData(tty, buf, count);

	len = MoxaPortWriteData(tty, buf, count);

	spin_unlock_bh(&moxa_lock);

	spin_unlock_irqrestore(&moxa_lock, flags);





	set_bit(LOWWAIT, &ch->statusflags);

	set_bit(LOWWAIT, &ch->statusflags);

	return len;

	return len;