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

From: chas williams - CONTRACTOR
Date: Thu Nov 29 2012 - 11:00:37 EST


On Thu, 29 Nov 2012 15:47:57 +0000
David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote:


> @@ -1020,12 +1048,15 @@ static uint32_t fpga_tx(struct solos_card *card)
> if (vcc) {
> atomic_inc(&vcc->stats->tx);
> solos_pop(vcc, oldskb);
> - } else {
> - struct pkt_hdr *header = (void *)oldskb->data;
> - if (le16_to_cpu(header->type) == PKT_PCLOSE)
> - complete(&SKB_CB(oldskb)->c);
> +
> + /*
> + * If it's a TX skb on a closed VCC, pclose()
> + * may be waiting for it...
> + */
> + if (!test_bit(ATM_VF_READY, &vcc->flags))
> + wake_up(&card->param_wq);
> + } else
> dev_kfree_skb_irq(oldskb);
> - }

the part that bothers me (and i dont have the programmer's guide for
the solos hardware) is that you are watching for the PKT_PCLOSE to be
sent to the card. shouldnt you be watching for the PKT_PCLOSE to be
returned from the card (assuming it does such a thing) so that you can
be assured that the tx/rx for this vpi/vci pair has been "stopped"?
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