Copy_from_user twice - character device

Question

I have implemented a personal device, and I would like to ask if this is correct:

• In user space, I have a structure with 2 pointers.

• I have writethis structure in my device.

• In my writefunction in a char device I have copy_from_userthis structure in kmalloced space.

• After that, I am in KS and got 2 pointers to the USA, so I want copy_from_usereveryone. Can I do this right after the first copy_from_userusing these copied addresses? They point to data in the US application that calls the function writenot for the function argument write char *buf.

Answer 1

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