Revert "tty: hvc: Fix data abort due to race in hvc_open" (cf9c9445) · Commits · 戴 / test

drivers/tty/hvc/hvc_console.c

+2 −14

Original line number	Original line	Diff line number	Diff line
	@@ -75,8 +75,6 @@ static LIST_HEAD(hvc_structs);
	*/		*/
	static DEFINE_MUTEX(hvc_structs_mutex);		static DEFINE_MUTEX(hvc_structs_mutex);

	/* Mutex to serialize hvc_open */
	static DEFINE_MUTEX(hvc_open_mutex);
	/*		/*
	* This value is used to assign a tty->index value to a hvc_struct based		* This value is used to assign a tty->index value to a hvc_struct based
	* upon order of exposure via hvc_probe(), when we can not match it to		* upon order of exposure via hvc_probe(), when we can not match it to
	@@ -348,24 +346,16 @@ static int hvc_install(struct tty_driver driver, struct tty_struct tty)
	*/		*/
	static int hvc_open(struct tty_struct tty, struct file filp)		static int hvc_open(struct tty_struct tty, struct file filp)
	{		{
	struct hvc_struct *hp;		struct hvc_struct *hp = tty->driver_data;
	unsigned long flags;		unsigned long flags;
	int rc = 0;		int rc = 0;

	mutex_lock(&hvc_open_mutex);

	hp = tty->driver_data;
	if (!hp) {
	rc = -EIO;
	goto out;
	}

	spin_lock_irqsave(&hp->port.lock, flags);		spin_lock_irqsave(&hp->port.lock, flags);
	/* Check and then increment for fast path open. */		/* Check and then increment for fast path open. */
	if (hp->port.count++ > 0) {		if (hp->port.count++ > 0) {
	spin_unlock_irqrestore(&hp->port.lock, flags);		spin_unlock_irqrestore(&hp->port.lock, flags);
	hvc_kick();		hvc_kick();
	goto out;		return 0;
	} /* else count == 0 */		} /* else count == 0 */
	spin_unlock_irqrestore(&hp->port.lock, flags);		spin_unlock_irqrestore(&hp->port.lock, flags);

	@@ -394,8 +384,6 @@ static int hvc_open(struct tty_struct tty, struct file filp)
	/* Force wakeup of the polling thread */		/* Force wakeup of the polling thread */
	hvc_kick();		hvc_kick();

	out:
	mutex_unlock(&hvc_open_mutex);
	return rc;		return rc;
	}		}

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