From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tomas Winkler <tomas.winkler@intel.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
Subject: Re: Getting weird TPM error after rebasing my tree to security/next-general
Date: Mon, 4 Feb 2019 13:58:23 +0200 [thread overview]
Message-ID: <20190204115823.GC26799@linux.intel.com> (raw)
In-Reply-To: <CAHk-=whO_TqDzQXSuSbgyZdVj9qeyRSxpjWXBQUWgvKGT2dnug@mail.gmail.com>
On Fri, Feb 01, 2019 at 10:04:35AM -0800, Linus Torvalds wrote:
> On Thu, Jan 31, 2019 at 12:45 PM Jarkko Sakkinen
> <jarkko.sakkinen@linux.intel.com> wrote:
> >
> > I understand what you mean. Just surprised that this hasn't failed
> > before to anyone (the same driver has been even successfully used
> > on ARM64 with TrustZone based fTPM implementation). It has been in
> > for three years now.
>
> Just to finish this thread off: it turns out that both ARM and ARM64
> worked fine, because neither did a memcpy(), but had explicit IO copy
> routines.
>
> And in those explicit routines, 32-bit ARM did only byte accesses, and
> 64-bit ARM did 8-byte accesses for the bulk transfer part, but byte
> accesses for the unaligned head and tail of the IO area.
>
> So I think it's all good. x86 used to work by luck (either because all
> machines that used that TPM chip always had ERMS, or because the
> people who didn't have it never cared), and ARM just worked because it
> would never do unaligned IO accesses anyway (well, I guess you can
> force them with "readl()" on an unaligned address, but then you just
> have yourself to blame).
>
> Linus
OK, thanks for the summary. This kind of answered to my question. Should
be sufficient to include the tpm_crb fix to the 5.1 PR.
/Jarkko
next prev parent reply other threads:[~2019-02-04 11:58 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-18 14:25 Getting weird TPM error after rebasing my tree to security/next-general Jarkko Sakkinen
2019-01-18 22:09 ` James Bottomley
2019-01-20 16:04 ` Jarkko Sakkinen
2019-01-22 1:02 ` Jarkko Sakkinen
2019-01-22 2:58 ` Jason Gunthorpe
2019-01-22 13:29 ` Jarkko Sakkinen
2019-01-22 18:26 ` Linus Torvalds
2019-01-23 15:36 ` Jarkko Sakkinen
2019-01-23 18:43 ` Linus Torvalds
2019-01-29 13:20 ` Jarkko Sakkinen
2019-01-31 12:26 ` Jarkko Sakkinen
2019-01-31 16:04 ` Jarkko Sakkinen
2019-01-31 17:06 ` Jarkko Sakkinen
2019-01-31 17:43 ` Linus Torvalds
2019-01-31 18:47 ` Jarkko Sakkinen
2019-01-31 18:35 ` Jarkko Sakkinen
2019-01-31 18:51 ` Linus Torvalds
2019-01-31 18:52 ` Linus Torvalds
2019-01-31 19:10 ` Linus Torvalds
2019-01-31 19:47 ` Winkler, Tomas
2019-02-01 8:12 ` Jarkko Sakkinen
2019-01-31 20:07 ` Winkler, Tomas
2019-01-31 20:47 ` Jarkko Sakkinen
2019-01-31 21:58 ` Linus Torvalds
2019-01-31 23:31 ` Jerry Snitselaar
2019-02-01 11:40 ` Jarkko Sakkinen
2019-01-31 20:45 ` Jarkko Sakkinen
2019-02-01 18:04 ` Linus Torvalds
2019-02-04 11:58 ` Jarkko Sakkinen [this message]
2019-01-23 20:11 ` Jarkko Sakkinen
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