Messages in this thread |  | | Date | Fri, 2 Nov 2001 14:42:36 -0800 (PST) | From | Ken Ashcraft <> | Subject | Re: null pointer questions |
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> > 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?
Thanks Ken
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