serial8250_startup() doesn't disable interrupts while taking the &up->port.lock
which might race against the interrupt handler serial8250_interrupt(), which
when entered, will deadlock waiting for the lock to be released.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Borislav Petkov 2008-07-29 22:33:32 -07:00 коммит произвёл Linus Torvalds
Родитель 5def9a3a22
Коммит c389d27b5e
1 изменённых файлов: 2 добавлений и 2 удалений

Просмотреть файл

@ -1885,7 +1885,7 @@ static int serial8250_startup(struct uart_port *port)
* the interrupt is enabled. Delays are necessary to
* allow register changes to become visible.
*/
spin_lock(&up->port.lock);
spin_lock_irqsave(&up->port.lock, flags);
if (up->port.flags & UPF_SHARE_IRQ)
disable_irq_nosync(up->port.irq);
@ -1901,7 +1901,7 @@ static int serial8250_startup(struct uart_port *port)
if (up->port.flags & UPF_SHARE_IRQ)
enable_irq(up->port.irq);
spin_unlock(&up->port.lock);
spin_unlock_irqrestore(&up->port.lock, flags);
/*
* If the interrupt is not reasserted, setup a timer to