panic(cpu 1 caller 0x29d59a): "Spinlock acquisition timed out: lock=0x869f20, lock owner thread=0x9cc17a8, current_thread: 0x868f000"@/SourceCache/xnu/xnu-1504.3.12/osfmk/i386/locks_i386.c:346
Backtrace (CPU 1), Frame : Return Address (4 potential args on stack)
0x42eade08 : 0x21b449 (0x5ce420 0x42eade3c 0x2238a5 0x0)
0x42eade58 : 0x29d59a (0x58ee74 0x869f20 0x9cc17a8 0x868f000)
0x42eade78 : 0x2311be (0x869f20 0x16dde1 0xb 0x1)
0x42eadec8 : 0x296dec (0x42ea904c 0x7abdffc5 0x4ceb 0x1090000)
0x42eadf18 : 0x2a761c (0x0 0x2a1acc 0x0 0x2b0c30)
0x42eadf58 : 0x2af626 (0x42f439f0 0x6039400 0xde 0x1050001)
0x42eadf88 : 0x2a8043 (0xde 0x42f439f0 0x12360 0x1)
0x42eadfd8 : 0x29eb5e (0x42f439f0 0x42eb6000 0x49153d98 0x2a10de)
0x42f43a98 : 0x2a747d (0x81e760 0x0 0x42f43ab8 0x2a1596)
0x42f43ab8 : 0x28d495 (0x1 0x0 0x1 0x42ea904c)
0x42f43b28 : 0x28e935 (0x6784570 0x684d4000 0x1 0x29d54e)
0x42f43b98 : 0x26be53 (0x9144 0x60 0x0 0x22712a)
0x42f43d48 : 0x25c0f7 (0x8c705c8 0xd4000 0x0 0x2000)
0x42f43e28 : 0x2638be (0x67a6b88 0x684d4000 0x1 0x2000)
0x42f43f18 : 0x479886 (0x67a6b88 0x684d4000 0x1 0x684d6000)
0x42f43f78 : 0x4ecbb9 (0x7261d20 0x75f2a28 0x76e4614 0x0)
0x42f43fc8 : 0x29f43d (0x75f2a24 0x0 0x10 0x75f2a24)

BSD process name corresponding to current thread: firefox