* Bryan O'Donoghue <pure.logic@xxxxxxxxxxxxxxxxx> wrote: > On Thu, 2016-02-18 at 08:58 +0100, Ingo Molnar wrote: > > So why not simply do the patch below? Very few people use boot > > parameters, and the > > complexity does not seem to be worth it. > > > > Furthermore I think an IMR range in itself is safe enough - it's not > > like such > > register state is going to be randomly corrupted, even with the > > 'lock' bit unset. > > > Hi Ingo. > > I agree - to flip the lock bit you need to be in ring-0 anyway. > > > So it's a perfectly fine protective measure against accidental memory > > corruption > > from the DMA space. It should not try to be more than that. > > > > And once we do this, I suggest we get rid of the 'lock' parameter > > altogether - > > that will further simplify the code. > > > > Thanks, > > > > Ingo > > That was the V1 of this patch > > https://groups.google.com/forum/#!topic/linux.kernel/6ZuVOF3TJow heh ;-) > Andriy asked for the boot parameter to control the state of the IMR > lock bit, I'm just as happy to go back to that version TBH I really think it's over-engineered - especially considering that with the kernel lock-down removed there's no other IMR area that is really locked down - so we could get rid of the whole 'locked' logic that would simplify the code throughout. Yeah, it's a nice looking hardware feature - but I don't think it's particularly useful in terms of extra protection. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
