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From: Ard Biesheuvel <ardb@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-efi <linux-efi@vger.kernel.org>,
	Matthew Garrett <mjg59@google.com>,
	Peter Jones <pjones@redhat.com>,
	Anton Vorontsov <anton@enomsg.org>,
	Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH 1/7] efi: pstore: disentangle from deprecated efivars module
Date: Thu, 24 Sep 2020 11:45:11 +0200	[thread overview]
Message-ID: <CAMj1kXGGk2v69u+67LAyiyCTCteWxuMoRmVmWFGNdFbMPm6hCA@mail.gmail.com> (raw)
In-Reply-To: <202009231400.E52D1C7E7@keescook>

On Wed, 23 Sep 2020 at 23:02, Kees Cook <keescook@chromium.org> wrote:
>
> On Wed, Sep 23, 2020 at 08:43:21PM +0200, Ard Biesheuvel wrote:
> > On Wed, 23 Sep 2020 at 20:41, Kees Cook <keescook@chromium.org> wrote:
> > >
> > > On Wed, Sep 23, 2020 at 06:13:58PM +0200, Ard Biesheuvel wrote:
> > > > The EFI pstore implementation relies on the 'efivars' abstraction,
> > > > which encapsulates the EFI variable store in a way that can be
> > > > overridden by other backing stores, like the Google SMI one.
> > > >
> > > > On top of that, the EFI pstore implementation also relies on the
> > > > efivars.ko module, which is a separate layer built on top of the
> > > > 'efivars' abstraction that exposes the [deprecated] sysfs entries
> > > > for each variable that exists in the backing store.
> > > >
> > > > Since the efivars.ko module is deprecated, and all users appear to
> > > > have moved to the efivarfs file system instead, let's prepare for
> > > > its removal, by removing EFI pstore's dependency on it.
> > > >
> > > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> > >
> > > With this and the other pstore patch, do the pstore self-tests still
> > > pass on an EFI system?
> > >
> > > If so, please consider both:
> > >
> > > Acked-by: Kees Cook <keescook@chromium.org>
> > >
> >
> > Selftests? Excellent! Are they documented too?
>
> Not really, but they're pretty simple:
>
> cd tools/testing/selftests/pstore
> *double-check "config" against running kernel config*
> ./pstore_tests
> ./pstore_crash_test
> *wait for system to reboot*
> cd tools/testing/selftests/pstore
> ./pstore_post_reboot_tests
>
> (though please test before/after, just to make sure other deltas haven't
> broken things before your series -- I don't test EFI pstore with high
> frequency)
>

I have done the 'before' test on three different EFI Linux systems
(x86, arm64 and ARM), and they all give me something like the below

=== Pstore unit tests (pstore_tests) ===
UUID=109d02e6-9395-4274-9554-2c078e87a662
Checking pstore backend is registered ... ok
  backend=efi
  cmdline=BOOT_IMAGE=/vmlinuz-5.3.0-59-generic
root=/dev/mapper/crypt-root ro quiet splash vt.handoff=1
Checking pstore console is registered ... FAIL
Checking /dev/pmsg0 exists ... FAIL
Writing unique string to /dev/pmsg0 ... FAIL

So I'm not sure if there is any point to doing the 'after' test if
this is the baseline.

  reply	other threads:[~2020-09-24  9:45 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-23 16:13 [PATCH 0/7] efi: deprecate/remove efivars sysfs interface Ard Biesheuvel
2020-09-23 16:13 ` [PATCH 1/7] efi: pstore: disentangle from deprecated efivars module Ard Biesheuvel
2020-09-23 18:41   ` Kees Cook
2020-09-23 18:43     ` Ard Biesheuvel
2020-09-23 21:02       ` Kees Cook
2020-09-24  9:45         ` Ard Biesheuvel [this message]
2020-09-24 10:30           ` Ard Biesheuvel
2020-09-23 16:13 ` [PATCH 2/7] efi: pstore: move workqueue handling out of efivars Ard Biesheuvel
2020-09-23 16:14 ` [PATCH 3/7] efi: efivars: un-export efivars_sysfs_init() Ard Biesheuvel
2020-09-23 16:14 ` [PATCH 4/7] efi: gsmi: fix false dependency on CONFIG_EFI_VARS Ard Biesheuvel
2020-09-23 16:14 ` [PATCH 5/7] efi: remove some false dependencies " Ard Biesheuvel
2020-09-23 16:14 ` [PATCH 6/7] efi: efivars: limit availability to X86 builds Ard Biesheuvel
2020-09-23 16:14 ` [PATCH 7/7] efi: efivars: remove deprecated sysfs interface Ard Biesheuvel

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