Messages in this thread |  | | Date | Sat, 28 Jan 2023 11:43:20 +0100 | From | Greg KH <> | Subject | Re: [PATCH-next v2 1/2] driver core: introduce get_device_unless_zero() |
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On Sat, Jan 28, 2023 at 05:41:45PM +0800, Zhong Jinghua wrote: > When the dev reference count is 0, calling get_device will go from 0 to 1,
You can NOT have a device reference count that is 0. If you do, you are doing something really really wrong, and there's a bug somewhere else.
> which will cause errors in some place of the kernel.
It's already an error in the kernel that tries to increment a reference count of 0 as that device is already freed and you are working with memory that is not present.
> So introduce a > get_devcie_unless_zero method that returns NULL when the dev reference > count is 0.
No, this is not ok, sorry, please never do this. Fix the caller.
thanks,
greg k-h
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