Messages in this thread Patch in this message | | | Date | Tue, 24 Jan 2012 11:52:27 +0100 | Subject | Re: [PATCH] net: caif: Don't act on notification for non-caif devices | From | Sjur Brændeland <> |
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Hi Sasha,
> Since the list of CAIF devices is stored in the net generic struct in each > net namespace, which is not initialized at that point, we see the following > BUG(): > > [ 200.752016] kernel BUG at include/net/netns/generic.h:40! ... > [ 200.752016] Call Trace: > [ 200.752016] [<ffffffff825c3cea>] ? get_cfcnfg+0x3a/0x180 > [ 200.752016] [<ffffffff821cf0b0>] ? lockdep_rtnl_is_held+0x10/0x20 > [ 200.752016] [<ffffffff825c41be>] caif_device_notify+0x2e/0x530
Argh, my bad. This issue has been identified and fixed by David Woodhouse earlier, but was reintroduced again by me when adding support for CAIF over NCM. The CAIF code is handling if net_generic() returns NULL, but I missed that net_generic() does BUG_ON().
> Instead, we'll first check if the device in the notification is a CAIF device: > - If it is - the net generic struct in that namespace must have been already > initialized. > - If not - just ignore it as we don't care about other devices. > > Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Nack, we have to handle other device types than just ARPHDR_CAIF after introducing CAIF over USB/NCM. I'd rather fix this in netns by removing the BUG_ON and return NULL. How about this instead:
diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h index 3419bf5..0fc2eea 100644 --- a/include/net/netns/generic.h +++ b/include/net/netns/generic.h @@ -37,8 +37,10 @@ static inline void *net_generic(const struct net *net, int id
rcu_read_lock(); ng = rcu_dereference(net->gen); - BUG_ON(id == 0 || id > ng->len); - ptr = ng->ptr[id - 1]; + if (id == 0 || id > ng->len) + ptr = NULL; + else + ptr = ng->ptr[id - 1]; rcu_read_unlock();
return ptr; I'll post a patch for this soon.
Regards, Sjur -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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