Re: [patch 2.4] make tty->count atomic_t

Russell King
2003-04-03T22:54:46Z

On Thu, Apr 03, 2003 at 12:16:21PM -0500, Jes Sorensen wrote:
> I believe the 2.4 tty code is racey in the way it handles tty->count.
> release_dev() does the tty->count-- thing without protecting against
> parallel execution, hence tty->count can end up a random state as
> tty->count-- isn't guaranteed to be atomic (load-store architectures and
> architectures with weak memory ordering etc).

Isn't release_dev() only called under the BKL, which guarantees the
old "single-thread in the kernel at a time" behaviour from pre-SMP
Linux ?

--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux