From: Jeff Moyer <jmoyer@redhat.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: [PATCH 2/3] libnvdimm/security: Tighten scope of nvdimm->busy vs security operations
Date: Mon, 19 Aug 2019 10:32:22 -0400 [thread overview]
Message-ID: <x49d0h1usy1.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <CAPcyv4iPBO9atdr_LdHNt=tCgjh-j_HyKXaCdUkWxb_J7OCcxg@mail.gmail.com> (Dan Williams's message of "Fri, 16 Aug 2019 14:02:19 -0700")
Dan Williams <dan.j.williams@intel.com> writes:
> On Fri, Aug 16, 2019 at 1:49 PM Jeff Moyer <jmoyer@redhat.com> wrote:
>>
>> Dan Williams <dan.j.williams@intel.com> writes:
>>
>> > The blanket blocking of all security operations while the DIMM is in
>> > active use in a region is too restrictive. The only security operations
>> > that need to be aware of the ->busy state are those that mutate the
>> > state of data, i.e. erase and overwrite.
>> >
>> > Refactor the ->busy checks to be applied at the entry common entry point
>> > in __security_store() rather than each of the helper routines.
>>
>> I'm not sure this buys you much. Did you test this on actual hardware
>> to make sure your assumptions are correct? I guess the worst case is we
>> get an "invalid security state" error back from the firmware....
>>
>> Still, what's the motivation for this?
>
> The motivation was when I went to test setting the frozen state and
> found that it complained about the DIMM being active. There's nothing
> wrong with freezing security while the DIMM is mapped. ...but then I
> somehow managed to write this generalized commit message that left out
> the explicit failure I was worried about. Yes, moved too fast, but the
> motivation is "allow freeze while active" and centralize the ->busy
> check so it's just one function to review that common constraint.
OK, thanks for the info.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
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next prev parent reply other threads:[~2019-08-19 14:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 1:20 [PATCH 0/3] libnvdimm/security: Enumerate the frozen state and other cleanups Dan Williams
2019-08-15 1:20 ` [PATCH 1/3] libnvdimm/security: Introduce a 'frozen' attribute Dan Williams
2019-08-16 20:34 ` Jeff Moyer
2019-08-15 1:20 ` [PATCH 2/3] libnvdimm/security: Tighten scope of nvdimm->busy vs security operations Dan Williams
2019-08-16 20:49 ` Jeff Moyer
2019-08-16 21:02 ` Dan Williams
2019-08-19 14:32 ` Jeff Moyer [this message]
2019-08-15 1:20 ` [PATCH 3/3] libnvdimm/security: Consolidate 'security' operations Dan Williams
2019-08-16 20:51 ` Jeff Moyer
2019-08-23 18:11 ` [PATCH 0/3] libnvdimm/security: Enumerate the frozen state and other cleanups Dave Jiang
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