On Fri, Jan 28, 2005 at 01:06:21 +0100, Bernd Petrovitsch wrote: > On Thu, 2005-01-27 at 09:14 -0800, Rock Gordon wrote: > > If I'm given a particular address, how do I test > > whether that address is from userspace or from kernel > > space? > > You don't. > > > I need to make these decisions from either inside a > > kernel module or a userspace program. The idea is I > > use memcpy() in the user-user version, > > copy_from/to_user in the kernel-kernel version, and > > prohibit the others. > > You need to know where the address is from and use the correct function. If the interface is defined as taking userland address, than kernel function passing a kernel address in is responsible for calling set_fs(KERNEL_DS) before and undoing it after. That way the copy_to/from_user does not complain. ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@xxxxxx>
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