Re: [PATCH v2 3/3] pppoatm: protect against freeing of vcc

On Wed, 28 Nov 2012 21:18:37 +0100
Krzysztof Mazur [off-list ref] wrote:

On Tue, Nov 27, 2012 at 07:28:43PM +0100, Krzysztof Mazur wrote:

quoted

I think that we should add atm_pop() function that does that and fix all
drivers.

I'm sending a patch that implements that idea.

Currently we need two arguments vcc and skb. However, we have reserved
ATM_SKB(skb)->vcc in skb control block for keeping vcc
and we can create single argument version vcc_pop(skb). In that case
we need to move:

	ATM_SKB(skb)->vcc = vcc;

from ATM drivers to functions that call atmdev_ops->send().

i dont like the vcc->pop() implementation and at one point i had the
crazy idea of using skb->destructors to handle it.  however, i think it
would be necessary to clone the skb's so any existing destructor is
preserved.

+#define vcc_pop(vcc, skb) vcc_pop_any(vcc, skb)
+#define vcc_pop_irq(vcc, skb) vcc_pop_any(vcc, skb)

don't define these if you dont plan on using them anway.