On 06/03/2013 04:53 PM, Steven Rostedt wrote: > > This way we wont be opening up any easy root holes where if a process > finds a way to modify some arbitrary kernel memory, we can prevent it > from modifying the current_idt_descr_ptr and have a nice way to exploit > the IDT. Sure, one can argue that if they can modify arbitrary kernel > memory, we may already be lost, but lets not make it easier for them > than need be. >
I don't like current_idt_descr_ptr if we can avoid it. It is a direct proxy for reading and writing the original IDT, in other words, it really hasn't really addressed the issue. What I'm thinking we really should have is a function that returns the IDT that we currently should be using, based on the current state. If that state is, say, tracing on/off and NMI on/off, then that can be indicated by bits in a state vector. The point is that the IDT address itself should not be mutable state if it can be at all avoided. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/