Re: [PATCH] net: caif: Don't act on notification for non-caif devices
From: Sasha Levin <hidden>
Date: 2012-01-24 15:23:48
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On Tue, Jan 24, 2012 at 10:06 AM, Sjur Brændeland [off-list ref] wrote:
Hi Sasha,quoted
quoted
Nack, we have to handle other device types than just ARPHDR_CAIF after introducing CAIF over USB/NCM.What my patch did was simply move the type check to above the net_generic call, it didn't add any new checks - which according to what you said, you'll need to do anyway.As I said I, don't think your patch would work. Try to see what happens if dev->type != ARPHDR_CAIF and caifd != NULL. Then the statement: if (caifd == NULL && dev->type != ARPHRD_CAIF) return 0; is very different from: if (dev->type != ARPHRD_CAIF) return 0; ... if (caifd == NULL) return 0;
Right.
quoted hunk ↗ jump to hunk
Anyway, another option could be to explicitly check if name space is initialized, similar to what net_generic() does,e.g. something like:diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c index 673728a..3197bc2 100644 --- a/net/caif/caif_dev.c +++ b/net/caif/caif_dev.c@@ -371,6 +371,13 @@ static int caif_device_notify(struct notifier_block *me, un struct cflayer *layer, *link_support; int head_room = 0; struct caif_device_entry_list *caifdevs; + int len; + + rcu_read_lock(); + len = rcu_dereference(dev_net(dev)->gen)->len; + rcu_read_unlock(); + if (caif_net_id > len) + return 0; cfg = get_cfcnfg(dev_net(dev)); caifdevs = caif_device_list(dev_net(dev));
We could, in that case we'd just need to handle the case where it was initialized by a device with higher id than CAIF (which we already do I think), and do it without touching net_generic structure directly. btw, Why do we store the devices per-namespace instead of globally? Is it such a big benefit in performance?