From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Vlastimil Babka <vbabka@suse.cz>, Peter Huewe <peterhuewe@gmx.de>,
Jason Gunthorpe <jgg@ziepe.ca>, Jan Dabros <jsd@semihalf.com>,
regressions@lists.linux.dev, LKML <linux-kernel@vger.kernel.org>,
linux-integrity@vger.kernel.org,
Dominik Brodowski <linux@dominikbrodowski.net>,
Herbert Xu <herbert@gondor.apana.org.au>,
Linus Torvalds <torvalds@linux-foundation.org>,
Johannes Altmanninger <aclopte@gmail.com>
Subject: Re: [REGRESSION] suspend to ram fails in 6.2-rc1 due to tpm errors
Date: Tue, 14 Mar 2023 14:53:11 +0100 [thread overview]
Message-ID: <ZBB8R9H3CyQnNfCt@zx2c4.com> (raw)
In-Reply-To: <ZBBxxftnXHVOjm92@kernel.org>
On Tue, Mar 14, 2023 at 03:08:21PM +0200, Jarkko Sakkinen wrote:
> On Tue, Mar 14, 2023 at 03:06:47PM +0200, Jarkko Sakkinen wrote:
> > On Tue, Mar 14, 2023 at 01:47:38PM +0100, Jason A. Donenfeld wrote:
> > > On 3/14/23, Jarkko Sakkinen <jarkko@kernel.org> wrote:
> > > > On Tue, Mar 14, 2023 at 10:35:33AM +0100, Thorsten Leemhuis wrote:
> > > >> On 09.01.23 17:08, Jason A. Donenfeld wrote:
> > > >> > On Thu, Jan 05, 2023 at 02:59:15PM +0100, Thorsten Leemhuis wrote:
> > > >> >> On 29.12.22 05:03, Jason A. Donenfeld wrote:
> > > >> >>> On Wed, Dec 28, 2022 at 06:07:25PM -0500, James Bottomley wrote:
> > > >> >>>> On Wed, 2022-12-28 at 21:22 +0100, Vlastimil Babka wrote:
> > > >> >>>>> Ugh, while the problem [1] was fixed in 6.1, it's now happening
> > > >> >>>>> again
> > > >> >>>>> on the T460 with 6.2-rc1. Except I didn't see any oops message or
> > > >> >>>>> "tpm_try_transmit" error this time. The first indication of a
> > > >> >>>>> problem
> > > >> >>>>> is this during a resume from suspend to ram:
> > > >> >>>>> tpm tpm0: A TPM error (28) occurred continue selftest
> > > >> >>>>> and then periodically
> > > >> >>>>> tpm tpm0: A TPM error (28) occurred attempting get random
> > > >> >>>>
> > > >> >>>> That's a TPM 1.2 error which means the TPM failed the selftest. The
> > > >> >>>> original problem was reported against TPM 2.0 because of a missing
> > > >> >>>> try_get_ops().
> > > >> >>>
> > > >> >>> No, I'm pretty sure the original bug, which was fixed by "char: tpm:
> > > >> >>> Protect tpm_pm_suspend with locks" regards 1.2 as well, especially
> > > >> >>> considering it's the same hardware from Vlastimil causing this. I
> > > >> >>> also
> > > >> >>> recall seeing this in 1.2 when I ran this with the TPM emulator. So
> > > >> >>> that's not correct.
> > > >> > [...]
> > > >> > So, this is now in rc3:
> > > >> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1382999aa0548a171a272ca817f6c38e797c458c
> > > >> >
> > > >> > That should help avoid the worst of the issue -- laptop not sleeping.
> > > >> > But the race or whatever it is still does exist. So you might want to
> > > >> > keep this in your tracker to periodically nudge the TPM folks about it.
> > > >>
> > > >> I did, and with -rc2 out now is a good time to remind everybody about
> > > >> it. Jarkko even looked into it, but no real fix emerged afaics. Or did
> > > >> it?
> > > >
> > > > Jason's workaround was picked. I asked some questions in the thread but
> > > > have not received any responses.
> > >
> > > As I've written several times now, that patch doesn't fix the issue.
> > > It makes it less common but it still exists and needs to be addressed.
> > > Please re-read my various messages describing this. I have nothing new
> > > at all to add; you just need to review my prior comments. There's a
> > > bug that probably needs to be fixed here by somebody who understands
> > > the tpm1 code.
> >
> > I'll try qemu path to see if I can reproduce it with/without the already
> > merged workaround.
>
> BTW, what sort of environment you had for your qemu run? I'm creating a
> simple initramfs with buildroot for this.
Nothing special at all in the userspace.
I think details of my test bed might be in some other thread from when
that original patch went in or when the original bug report came, but
from memory, I believe what I did to reliably reproduce various issues
was comment out the sleep in random.c so that it keeps asking the TPM
for more bytes from the kthread, like this:
diff --git a/drivers/char/random.c b/drivers/char/random.c
index ce3ccd172cc8..708110c780aa 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -934,20 +934,20 @@ EXPORT_SYMBOL(add_device_randomness);
void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy, bool sleep_after)
{
mix_pool_bytes(buf, len);
credit_init_bits(entropy);
/*
* Throttle writing to once every reseed interval, unless we're not yet
* initialized or no entropy is credited.
*/
- if (sleep_after && !kthread_should_stop() && (crng_ready() || !entropy))
- schedule_timeout_interruptible(crng_reseed_interval());
+// if (sleep_after && !kthread_should_stop() && (crng_ready() || !entropy))
+// schedule_timeout_interruptible(crng_reseed_interval());
}
EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
/*
* Handle random seed passed by bootloader, and credit it depending
* on the command line option 'random.trust_bootloader'.
*/
void __init add_bootloader_randomness(const void *buf, size_t len)
{
Then I hooked the tpm emulator up to qemu and put it in tpm1 mode. I had
userspace `echo mem > /sys/power/state` every couple of seconds (or
continuously maybe?), and then I used the qemu monitor interface to wake
the system from sleep. And kaboom.
Jason
next prev parent reply other threads:[~2023-03-14 13:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-28 20:22 [REGRESSION] suspend to ram fails in 6.2-rc1 due to tpm errors Vlastimil Babka
2022-12-28 23:07 ` James Bottomley
2022-12-29 4:03 ` Jason A. Donenfeld
2022-12-29 4:16 ` Jason A. Donenfeld
2023-01-05 13:59 ` Thorsten Leemhuis
2023-01-05 14:25 ` Vlastimil Babka
2023-01-05 14:47 ` [PATCH] tpm: Disable hwrng for TPM 1 if PM_SLEEP is enabled Jason A. Donenfeld
2023-01-05 14:53 ` Jason A. Donenfeld
2023-01-05 21:58 ` Linus Torvalds
2023-01-05 22:29 ` Jason A. Donenfeld
2023-01-06 3:01 ` [PATCH v2] tpm: Allow system suspend to continue when TPM suspend fails Jason A. Donenfeld
2023-01-06 16:01 ` Jason A. Donenfeld
[not found] ` <CAA25o9RGVbiXS6ne53gdM1K706zT=hm5c-KuMWrCA_CJtJDXdw@mail.gmail.com>
2023-01-06 17:16 ` Jason A. Donenfeld
2023-01-06 18:59 ` Linus Torvalds
2023-01-06 20:04 ` Luigi Semenzato
2023-01-06 22:28 ` Linus Torvalds
2023-01-09 16:05 ` Jason A. Donenfeld
2023-01-16 8:12 ` Jarkko Sakkinen
2023-01-16 14:03 ` Jason A. Donenfeld
2023-01-21 0:07 ` Jarkko Sakkinen
2023-01-16 11:44 ` Jarkko Sakkinen
2023-01-16 14:00 ` Vlastimil Babka
2023-01-21 0:03 ` Jarkko Sakkinen
2023-01-05 15:17 ` [REGRESSION] suspend to ram fails in 6.2-rc1 due to tpm errors James Bottomley
2023-01-05 15:27 ` Jason A. Donenfeld
2023-01-05 15:32 ` Jason A. Donenfeld
2023-01-09 16:08 ` Jason A. Donenfeld
2023-01-10 17:19 ` Vlastimil Babka
2023-01-20 23:47 ` Jarkko Sakkinen
2023-03-14 9:35 ` Thorsten Leemhuis
2023-03-14 12:19 ` Jarkko Sakkinen
2023-03-14 12:47 ` Jason A. Donenfeld
2023-03-14 13:05 ` Jarkko Sakkinen
2023-03-14 13:08 ` Jarkko Sakkinen
2023-03-14 13:53 ` Jason A. Donenfeld [this message]
2023-03-14 14:23 ` Jarkko Sakkinen
2023-04-21 15:03 ` Jarkko Sakkinen
2023-04-21 18:27 ` Jason A. Donenfeld
2023-04-23 15:34 ` Jarkko Sakkinen
2023-04-25 23:34 ` Jarkko Sakkinen
2023-04-26 1:32 ` Jason A. Donenfeld
2023-04-26 16:07 ` Jarkko Sakkinen
2023-04-26 17:00 ` Jarkko Sakkinen
2023-01-04 9:10 ` Johannes Altmanninger
2023-01-16 11:30 ` Jarkko Sakkinen
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