Re: [PATCH] 2.4.18 Eicon ISDN driver fix.

[petter wahlman <petter@bluezone.no>]

On Thu, 2002-02-28 at 18:41, Marcelo Tosatti wrote:
> 
> 
> On Wed, 27 Feb 2002, Armin Schindler wrote:
> 
> > The patch below fixes the race condition with copy_to_user and will
> > not introduce a new race. What can happen is that two reader-processes
> > may get mixed-up messages, but more than one reader isn't allowed here
> > anyway.
> > 
> > Please apply this patch to 2.4 and 2.2, it works for both.
> 
> Armin, 
> 
> Your patch does not apply cleanly against my tree.
> 
> Please regenerate it.
> 

--- linux/drivers/isdn/eicon/eicon_mod.c        Fri Dec 21 18:41:54 2001
+++ linux-2.4.18-pw/drivers/isdn/eicon/eicon_mod.c      Thu Feb 28
21:48:32 2002
@@ -665,8 +665,11 @@
                        else
                                cnt = skb->len;

-                       if (user)
+                       if (user) {
+                               spin_unlock_irqrestore(&eicon_lock,
flags);
                                copy_to_user(p, skb->data, cnt);
+                               spin_lock_irqsave(&eicon_lock, flags);
+                       }
                        else
                                memcpy(p, skb->data, cnt);