Re: Getting weird TPM error after rebasing my tree to security/next-general

[Jerry Snitselaar]

On Thu Jan 31 19, Linus Torvalds wrote:
> On Thu, Jan 31, 2019 at 12:47 PM Jarkko Sakkinen
> <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
> > I'll try it first thing when I wake up tomorrow (11PM in Finland ATM).
>
> Thanks.
>
> > Appreciate for taking time on this.
>
> Hey, it was my commit that broke it for you. Even if it happened to
> work before, and only did so by pure luck, it was a functional
> regression.
>
> I get very upset when other developers don't step up when *their*
> changes break something, and I don't consider "it shouldn't have
> worked in the first place" to be a valid excuse. You broke it, you'd
> better fix it.
>
> So I had better fix my own mess too, in order to not look too hypocritical.
>
> And I was very aware that hardcoding the memcpy_*io() access patterns
> might break something. I just _hoped_ it wouldn't, because we actually
> ended up going back to the very original access patterns (but it was
> from a long long time ago).
>
> In fact, while it's slightly annoying, in many ways it's actually good
> that we found breakage, and could pinpoint exactly *why* it broke.
> That does validate the whole "we shouldn't just depend on the random
> implementation detail of 'memcpy()'" argument.
>
> So I'll wait to hear back whether that patch fixes things for you, but
> I _think_ it will, and we'll be better off in the long range with this
> whole thing.
>
>              Linus

I just did a quick test here of booting and running a couple commands
(tpm2_getcap, tpm2_pcrlist), and the patch seems to work for me. I was
seeing the error during tpm_crb initialization without the patch.