Tomko wrote:
Catalin Marinas wrote:
what u means "OK"? kernel space should have right to access any memory address , can u expained in details what u means "OK"?
No, it is because this function checks whether the access to the user space address is OK. There are situations when it can also sleep (page not present).
The user may not have any right to that memory, that means he has no right to ask the kernel to mess with it either, even if the kernel is authorized to do so.
Just as you can't ask a cop to jail someone. Sure, the cop has the power to arrest, but he will check that there is reason to do so and not automatically assume that you are right.
Helge Hafting - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
