unregister_input_polled_device() leads to null pointer deref
Hi, I'm writing a i2c device driver. In probe(), among other things I call: polled_input = input_allocate_polled_device(); input_register_polled_device(polled_input); Then inside remove(), I extract the instance of input_polled_dev and call input_unregister_polled_device(polled_input); This results in kernel error: "Unable to handle kernel NULL pointer dereference at virtual address 00000474". It turns out that the input_dev pointer inside input_polled_dev is null which leads to this error. But why is input_dev pointer null? It is not null inside probe() function and I don't release it anywhere. This is code: http://pastebin.com/JJdepyEG and here is link to the output, along with my log statements: http://pastebin.com/badwSvyy. Thanks, Okash
On Mon, Mar 28, 2016 at 3:32 PM, Okash Khawaja <okash.khawaja@gmail.com> wrote:
Hi,
I'm writing a i2c device driver. In probe(), among other things I call:
polled_input = input_allocate_polled_device(); input_register_polled_device(polled_input);
Then inside remove(), I extract the instance of input_polled_dev and call
input_unregister_polled_device(polled_input);
This results in kernel error:
"Unable to handle kernel NULL pointer dereference at virtual address 00000474".
It turns out that the input_dev pointer inside input_polled_dev is null which leads to this error. But why is input_dev pointer null? It is not null inside probe() function and I don't release it anywhere.
This is code: http://pastebin.com/JJdepyEG and here is link to the output, along with my log statements: http://pastebin.com/badwSvyy.
input_free_polled_device(polled_input) is always called in your probe function. -- Carlo Caione
On 28 Mar 2016, at 14:55, Carlo Caione <carlo@caione.org> wrote:
On Mon, Mar 28, 2016 at 3:32 PM, Okash Khawaja <okash.khawaja@gmail.com> wrote: Hi,
I'm writing a i2c device driver. In probe(), among other things I call:
polled_input = input_allocate_polled_device(); input_register_polled_device(polled_input);
Then inside remove(), I extract the instance of input_polled_dev and call
input_unregister_polled_device(polled_input);
This results in kernel error:
"Unable to handle kernel NULL pointer dereference at virtual address 00000474".
It turns out that the input_dev pointer inside input_polled_dev is null which leads to this error. But why is input_dev pointer null? It is not null inside probe() function and I don't release it anywhere.
This is code: http://pastebin.com/JJdepyEG and here is link to the output, along with my log statements: http://pastebin.com/badwSvyy.
input_free_polled_device(polled_input) is always called in your probe function.
Of course! Thanks very much
-- Carlo Caione
participants (2)
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Carlo Caione -
Okash Khawaja