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SubjectRe: null pointer questions
> > 2. What happens if I pass a null pointer as the destination parameter
> > to copy_from_user? Does copy_from_user handle it safely or will the
> > kernel seg fault?
> The kernel won't crash, but it might fail (depending on whether 0 is a
> valid user space address or not).

Why does it matter if 0 is a valid user space or not? If I make the call

copy_from_user(0, user_ptr, 4);

the null pointer is the kernel address, not the user address. Can you
clarify please?


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