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tty, serial: Fix race and NULL check in uart_close() 

Commit 46d57a449a ("serial: use tty_port pointers in the core code")
contained two bugs that causes (rare) crashes:

 - the rename typoed one site

 - a NULL check was missed

Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2009-10-12 19:13:54 +02:00
parent d93a8f829f
commit eea7e17e0e
1 changed files with 5 additions and 2 deletions
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7
drivers/serial/serial_core.c
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@ -1270,6 +1270,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
BUG_ON(!kernel_locked());
if (!state)
return;
uport = state->uart_port;
port = &state->port;
@ -1316,9 +1319,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
*/
if (port->flags & ASYNC_INITIALIZED) {
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
spin_lock_irqsave(&uport->lock, flags);
uport->ops->stop_rx(uport);
spin_unlock_irqrestore(&port->lock, flags);
spin_unlock_irqrestore(&uport->lock, flags);
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially