Re: [linux-usb-devel] Re: [OOPS, usbcore, releaseintf] 2.6.0-test10-mm1

[Duncan Sands]

> I didn't note the reason for the oops.  Was it a segmentation violation?
> The usb_device memory isn't deallocated until the reference count goes to
> 0.  Maybe something was doing an extra usb_put_dev.

Maybe this is related to "oopses in kobjects in 2.6.0-test11 (was Re: kobject patch)"?
My call to usb_put_dev in usbdev_release is releasing the kobject,
which shows that the reference count was not already zero.  However
it dereferences a NULL pointer in here:

static void hcd_pci_release(struct usb_bus *bus)
{
        struct usb_hcd *hcd = bus->hcpriv;

        if (hcd)
                hcd->driver->hcd_free(hcd);
}

which suggests that the hcd was already released.  Maybe Greg can comment?

[9889]: shutting down for system reboot
printing eip:
c8ae8999
Oops: 0000 [#1]
PREEMPT
CPU:    0
EIP:    0060:[<c8ae8999>]    Not tainted VLI
EFLAGS: 00010286
EIP is at hcd_pci_release+0x19/0x20 [usbcore]
eax: c8c69d80   ebx: c637f050   ecx: c8af6c20   edx: c637f000
esi: c031e65c   edi: c031e680   ebp: c0019ec4   esp: c0019ec0
ds: 007b   es: 007b   ss: 0068
Process modem_run (pid: 8460, threadinfo=c0018000 task=c1508080)
Stack: c637f000 c0019ed0 c8ae455d c637f000 c0019ee8 c0203738 c637f048 
c0019f00
c8ae77d6 c031e450 c0019f00 c01bc88f c637f050 c6b09200 c031e428 c031e440
c0019f10 c8ae08b6 c637f050 00000000 c0019f2c c02019e1 c6b092cc c0019f2c
Call Trace:
[<c8ae455d>] usb_host_release+0x1d/0x20 [usbcore]
[<c0203738>] class_dev_release+0x58/0x60
[<c8ae77d6>] usb_destroy_configuration+0xb6/0xf0 [usbcore]
[<c01bc88f>] kobject_cleanup+0x6f/0x80
[<c8ae08b6>] usb_release_dev+0x46/0x60 [usbcore]
[<c02019e1>] device_release+0x21/0x80
[<c01bc88f>] kobject_cleanup+0x6f/0x80
[<c8ae9b38>] usbdev_release+0x88/0xc0 [usbcore]
[<c0157a5c>] __fput+0x10c/0x120
[<c0156047>] filp_close+0x57/0x80
[<c01560d1>] sys_close+0x61/0x90
[<c02a302e>] sysenter_past_esp+0x43/0x65

Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 e5 83 
ec 04 8b 45 08 8b 50 30 85 d2 74 0c 8b 82 08 01 00 00 89 14 24 <ff> 50 
28 c9 c3 89 f6 55 89 e5 57 56 53 83 ec 34 8b 5d 0c e8 3f

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