Messages in this thread Patch in this message | | | Subject | Re: [tpmdd-devel] [PATCH RFC v3 5/5] tpm2: expose resource manager via a device link /dev/tpms<n> | From | James Bottomley <> | Date | Sat, 21 Jan 2017 12:38:56 -0800 |
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On Fri, 2017-01-20 at 23:05 +0200, Jarkko Sakkinen wrote: > On Fri, Jan 20, 2017 at 03:39:14PM +0200, Jarkko Sakkinen wrote: > > On Thu, Jan 19, 2017 at 07:19:40AM -0500, James Bottomley wrote: > > > On Thu, 2017-01-19 at 12:49 +0200, Jarkko Sakkinen wrote: > > > > On Wed, Jan 18, 2017 at 10:01:03AM -0500, James Bottomley > > > > wrote: > > > > > On Mon, 2017-01-16 at 15:12 +0200, Jarkko Sakkinen wrote: > > > > > > From: James Bottomley < > > > > > > James.Bottomley@HansenPartnership.com> > > > > > > > > > > > > Currently the Resource Manager (RM) is not exposed to > > > > > > userspace. > > > > > > Make this exposure via a separate device, which can now be > > > > > > opened multiple times because each read/write transaction > > > > > > goes > > > > > > separately via the RM. > > > > > > > > > > > > Concurrency is protected by the chip->tpm_mutex for each > > > > > > read/write transaction separately. The TPM is cleared of > > > > > > all > > > > > > transient objects by the time the mutex is dropped, so > > > > > > there > > > > > > should be no interference between the kernel and userspace. > > > > > > > > > > There's actually a missing kfree of context_buf on the > > > > > tpms_release > > > > > path as well. This patch fixes it up. > > > > > > > > Can you send me a fresh version of the whole patch so that I > > > > can > > > > include to v4 that includes also changes that I requested in my > > > > recent comments + all the fixes? > > > > > > Sure, I think the attached is basically it > > > > > > James > > > > Thank you! > > 'tabrm4' branch has been now rebased. It's now on top of master > branch that contains Stefan's latest patch (min body length check) > that I've reviewed and tested. It also contains your updated > /dev/tpms patch. > > I guess the 5 commits that are there now are such that we have fairly > good consensus, don't we? If so, can I add your reviewed-by and > tested-by to my commits and vice versa?
It looks like there's another problem: you need a continue after the transient object is garbage collected otherwise the code falls through, does a flush which fails and then adds a ~0 as the handle meaning we'll have a mismatch between the saved contexts and the handles.
James
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commit 0da3f83ce889379bd1741a11b07a30818a223924 Author: James Bottomley <James.Bottomley@HansenPartnership.com> Date: Sat Jan 21 12:19:06 2017 -0800
continue after lazy reclaim
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 8713d7f..9d87537 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -288,9 +288,10 @@ static int tpm2_save_space(struct tpm_chip *chip) rc = tpm2_save_context(chip, space->context_tbl[i], space->context_buf, PAGE_SIZE, &offset); - if (rc == -ENOENT) + if (rc == -ENOENT) { space->context_tbl[i] = 0; - else if (rc) { + continue; + } else if (rc) { tpm2_flush_space(chip); return rc; }
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