Messages in this thread | | | Date | Sat, 7 Jul 2007 00:50:46 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [1/2] 2.6.22-rc7: known regressions |
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(CC list trimmed)
On Thu, 5 Jul 2007, Dmitry Torokhov wrote:
> > > NIP [c001870c] strlen+0x4/0x18 > > > LR [c0134fec] kobject_get_path+0x34/0xc4 > > > Call Trace: > > > [eed5be90] [c01d5124] class_uevent+0xac/0x1bc > > > [eed5bed0] [c01357e4] kobject_uevent_env+0x23c/0x460 > > > [eed5bf20] [c01d485c] class_device_del+0x178/0x1a0 > > > [eed5bf40] [c01d489c] class_device_unregister+0x18/0x30 > > > [eed5bf60] [c021f820] input_unregister_device+0xf4/0x130 > > > [eed5bf70] [c0242f4c] hidinput_disconnect+0x2c/0x60 > > > [eed5bf90] [f27f2bac] hidp_session+0x550/0x584 [hidp] > > > [eed5bff0] [c0013e28] kernel_thread+0x44/0x60 [...] > > I'm not seeing any reference counting or other protection for the device > > ("input") on "hid->inputs" list. But I don't know the code. Dmitry? Jiri?
This should be automatically done by proper dev.parent setting of the corresponding input device, as already mentioned by Dmitry.
> This should pin hid object untill all inputs are released. However > bluetooth does not use driver model and does not have hid->dev set up > and so it looks like we are simply trying to unregister an input device > that is already gone... I still don't quite get how we unregister the > same device twice - it is done from a per-hid-device thread in hidp...
Actually even bluetooth HID seems to set up hid->dev correctly in hidp_setup_hid() and also sets properly dev.parent in hidp_setup_input().
Marcel, what is please the point behind this code in hidp_add_connection():
if (!session->hid) { session->input = input_allocate_device(); if (!session->input) { kfree(session); return -ENOMEM; } }
I suspect that the oops happens during freeing this extra device which is not allocated inside hid core, but I can't immediately see from the code what is the exact purpose of this 'extra' input device and why don't the input devices allocated and registered in hidinput_connect() suffice? usbhid doesn't need to register any extra input devices, everything is handled solely in hid-input core.
Seems like it could be triggered by ioctl() with ca->req->rd_size set to 0, but I am not that familiar with the bluetooth code to see it immediately.
Thanks,
-- Jiri Kosina - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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