On 13 March 2018 at 10:38, Greg KH <greg@xxxxxxxxx> wrote: > On Tue, Mar 13, 2018 at 10:13:26AM +0000, Ard Biesheuvel wrote: >> On 13 March 2018 at 10:04, Greg KH <greg@xxxxxxxxx> wrote: >> > On Wed, Mar 07, 2018 at 06:24:09PM +0000, Ard Biesheuvel wrote: >> >> On 2 March 2018 at 16:54, Greg KH <greg@xxxxxxxxx> wrote: ... >> >> > Please test on the hardware that is affected, otherwise you do not know >> >> > if your patches do anything or not. >> >> > >> >> >> >> I don't think it is feasible to test these backports by confirming >> >> that they make the fundamental issue go away. We simply don't have the >> >> code to reproduce all the variants, and we have to rely on the >> >> information provided by ARM Ltd. regarding which cores are affected >> >> and which aren't. >> > >> > You really don't have the reproducers? Please work with ARM to resolve >> > that, this should not be a non-tested set of patches. That's really >> > worse than no patches at all, as if they were applied, that would >> > provide a false-sense of "all is fixed". >> > >> >> I know that on x86, the line between architecture and platform is >> blurry. That is not the case on ARM, though. >> >> Unlike platform firmware, the OS is built on top of an abstracted >> platform which is described by ARM's Architecture Reference Manual. If >> ARM Ltd. issues recommendations regarding what firmware PSCI methods >> to call when doing a context switch, or which barrier instruction to >> issue in certain circumstances, they do so because a certain class of >> hardware may require it in some cases. It is really not up to me to go >> find some exploit code on GitHub, run it before and after applying the >> patch and conclude that the problem is fixed. Instead, what I should >> do is confirm that the changes result in the recommended actions to be >> taken at the appropriate times. > > To _not_ take that exploit code and run it to _verify_ that your patches > work, would be foolish, right? > Oh, absolutely. But that presupposes access to both the affected hardware and the exploit code. > I can't believe we are having the argument of "Test that your patches > actually work"... > > Ugh, these series are all now dropped from my patch queue until you all > get your act together and get someone to verify the changes actually > work. > Fair enough. If anyone needs these patches for their systems, they can respond with a Tested-by: