Description of problem: Booting the kernel in question causes a kernel panic with a reason of "bad locking". Version-Release number of selected component (if applicable): kernel-2.6.16-1.2181_FC6 udev-090-1 How reproducible: always Steps to Reproduce: 1. boot kernel in question 2. 3. Actual results: Welcome to Fedora Core Press 'I' to enter interactive startup. Setting clock (localtime): Mon May 1 10:08:29 MDT 2006 [ OK ] Starting udev: BUG: spinlock bad magic on CPU#0, events/0/5 (Not tainted) lock: dfd16200, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Kernel panic - not syncing: bad locking Expected results: Additional info: Even though the output seems to imply the bug is in udev, I'm filing against kernel because booting an earlier kernel (kernel-2.6.16-1.2147_FC6) does not show this problem.
I encountered the same problem. In my case, the bad locking bug was caused by bcm43xx driver. When I add the bcm43xx to /etc/modprobe.d/blacklist, the udev does not cause the panic. I dug deep into this bug, and I found that it was caused by netif_tx_disable() in the ieee80211softmac_start_scan(). In the netif_tx_disable(), dev->xmit_lock was locked, but it was not initialized yet. I think the linux-2.6-bcm43xx-assoc-on-startup.patch was caused this bug, because this patch called schedule_work(&bcm->softmac->associnfo.work) before calling register_netdev() function, but the dev->xmit_lock was initialized in the register_netdev().
Fixed in recent rawhide kernels.