Oops while unloading module

From: Gaël Deest
Date: Sat Dec 20 2003 - 07:23:02 EST


I first apologize for my approximative english.

I will soon get a Logitech Quickcam pro 4000, so I compiled my kernel with the PWC driver for Philips webcams (built-in). In addition, I tried to load the external (and closed-source) pwcx module (without the webcam plugged-in, of course). When I wanted to unload it with rmmod, it ended with "Segmentation fault" and I got the following Oops :

Dec 20 00:39:56 home kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
Dec 20 00:39:56 home kernel: printing eip:
Dec 20 00:39:56 home kernel: 00000000
Dec 20 00:39:56 home kernel: *pde = 00000000
Dec 20 00:39:56 home kernel: Oops: 0000 [#1]
Dec 20 00:39:56 home kernel: CPU: 0
Dec 20 00:39:56 home kernel: EIP: 0060:[<00000000>] Tainted: PF
Dec 20 00:39:56 home kernel: EFLAGS: 00210246
Dec 20 00:39:56 home kernel: EIP is at 0x0
Dec 20 00:39:56 home kernel: eax: 00000000 ebx: e1a11d40 ecx: 00000000 edx: e1a11d40
Dec 20 00:39:56 home kernel: esi: c045f718 edi: 00000000 ebp: 00000880 esp: c2fadf5c
Dec 20 00:39:56 home kernel: ds: 007b es: 007b ss: 0068
Dec 20 00:39:56 home kernel: Process rmmod (pid: 13771, threadinfo=c2fac000 task=cfd4e040)
Dec 20 00:39:56 home kernel: Stack: c0133549 e1a11d40 bffff7b0 0000003b 00000000 78637770 40016000 c0147787
Dec 20 00:39:56 home kernel: df571100 c7da6700 c2454e80 40016000 40017000 40017000 c2454e80 df571100
Dec 20 00:39:56 home kernel: df571120 00000000 c2fac000 00147814 df571100 bffff7b0 bffff7b0 00000880
Dec 20 00:39:56 home kernel: Call Trace:
Dec 20 00:39:56 home kernel: [<c0133549>] sys_delete_module+0x119/0x190
Dec 20 00:39:56 home kernel: [<c0147787>] do_munmap+0x147/0x190
Dec 20 00:39:56 home kernel: [<c01091c7>] syscall_call+0x7/0xb
Dec 20 00:39:56 home kernel:
Dec 20 00:39:56 home kernel: Code: Bad EIP value.

Then, I wanted to see if the module was here again and typed "lsmod", and it hanged. At this state, I can't load any other module because modprobe hangs too. My kernel is compiled with both "module unloading" and "forced module unloading."

If needed, may you tell me how I could provide further informations ?

Thanks :-) And great job for 2.6 anyway ;-)
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