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@xxxxxxxxxx> 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
