[openib-general] IPoIB oops when removing ib_ipoib module

[Hal Rosenstock]

Hi,

With the latest OpenIB svn, I got the following oops when attempting to
remove the ib_ipoib module on x86 with 2.6.15.

-- Hal

Unable to handle kernel NULL pointer dereference at virtual address 00000004
 printing eip:
d1b8299f
*pde = 07114067
*pte = 00000000
Oops: 0002 [#1]
DEBUG_PAGEALLOC
Modules linked in: ib_ipoib ib_sa ib_umad ide_cd cdrom lp ipv6 autofs parport_pc parport uhci_hcd ehci_hcd ib_mthca ib_mad ib_core ohci_hcd eepro100 mii usbcore
CPU:    0
EIP:    0060:[<d1b8299f>]    Not tainted VLI
EFLAGS: 00210046   (2.6.15) 
EIP is at ipoib_neigh_free+0xd/0x27 [ib_ipoib]
eax: 00000000   ebx: cdd23f64   ecx: 00200207   edx: c0aa6d80
esi: 00200246   edi: cdd23f64   ebp: cdd23ef8   esp: c9d81ec8
ds: 007b   es: 007b   ss: 0068
Process ipoib (pid: 4403, threadinfo=c9d80000 task=cc6fbad0)
Stack: d1b845a5 c0aa6d80 ffff0000 00000000 00000000 00000000 cc6c4a80 c9d81f08 
       cb6b2ef8 cc6c4a80 cb6b2ef8 d1b86563 cdd23ef8 cc6c4800 cdd23ef8 00200246 
       cdd23f4c c0614f4c cc6c4800 00000001 00000000 c7582f78 d1b83dbd cc6c4800 
Call Trace:
[<d1b845a5>] ipoib_mcast_free+0x10d/0x226 [ib_ipoib]
[<d1b86563>] ipoib_mcast_dev_flush+0xe1/0x12b [ib_ipoib]
[<d1b83dbd>] ipoib_ib_dev_down+0x56/0xbf [ib_ipoib]
[<d1b8422c>] ipoib_ib_dev_flush+0x3c/0xc3 [ib_ipoib]
[<c01223fd>] worker_thread+0x174/0x1ec
[<d1b841f0>] ipoib_ib_dev_flush+0x0/0xc3 [ib_ipoib]
[<c0125a9e>] kthread+0x6d/0xa7
[<c01118a5>] default_wake_function+0x0/0x12
[<c0298288>] schedule+0x37a/0x5a5
[<c01118a5>] default_wake_function+0x0/0x12
[<c0122289>] worker_thread+0x0/0x1ec
[<c0125ad1>] kthread+0xa0/0xa7
[<c0125a31>] kthread+0x0/0xa7
[<c01012e5>] kernel_thread_helper+0x5/0xb
Code: d2 59 74 18 89 5a 20 89 53 44 8b 42 20 8b 80 90 00 00 00 c7 40 04 12 28 b8 d1 89 d0 5b c3 8b 54 24 04 8b 42 20 8b 80 90 00 00 00 <c7> 40 04 00 00 00 00 8b 42 20 c7 40 44 00 00 00 00 89 54 24 04 
<6>loop: loaded (max 8 devices)