Re: WARNING: CPU: 1 PID: 83 at arch/x86/kernel/cpu/sgx/main.c:446 ksgxd+0x1b7/0x1d0

[Paul Menzel]

Dear Jarkko,


Am 25.08.22 um 07:25 schrieb Jarkko Sakkinen:
> On Thu, Aug 25, 2022 at 07:57:30AM +0300, Jarkko Sakkinen wrote:
> > On Fri, Aug 19, 2022 at 11:28:24AM -0700, Dave Hansen wrote:
> > > On 8/19/22 09:02, Paul Menzel wrote:
> > > > On the Dell XPS 13 9370, Linux 5.18.16 prints the warning below:
> > > >
> > > > ```
> > > > [    0.000000] Linux version 5.18.0-4-amd64 (debian-kernel@xxxxxxxxxxxxxxxx) (gcc-11 (Debian 11.3.0-5) 11.3.0, GNU ld (GNU Binutils for Debian) 2.38.90.20220713) #1 SMP PREEMPT_DYNAMIC Debian 5.18.16-1 (2022-08-10)
> > > > [    0.000000] Command line: BOOT_IMAGE=/vmlinuz-5.18.0-4-amd64 root=UUID=56f398e0-1e25-4fda-aa9f-611dece4b333 ro quiet
> > > > […]
> > > > [    0.000000] DMI: Dell Inc. XPS 13 9370/0RMYH9, BIOS 1.21.0 07/06/2022
> > > > […]
> > > > [    0.235418] sgx: EPC section 0x40200000-0x45f7ffff

> > > Would you be able to send the entire dmesg, along with:
> > >
> > > 	cat /proc/iomem # (as root)
> > > and
> > > 	cpuid -1 --raw
> > >
> > > I'm suspecting either a BIOS problem.  Reinette (cc'd) also thought this
> > > might be a case of the SGX initialization getting a bit too far along
> > > when it should have been disabled.
> > >
> > > We had some bugs where we didn't stop fast enough after spitting out the
> > > "SGX Launch Control is locked..." errors.
> >
> > For some reason the pages do not get properly sanitized:
> >
> > 	/* sanity check: */
> > 	WARN_ON(!list_empty(&sgx_dirty_page_list));
> >
> > EPC should be good, given that EREMOVE does not fail.
> > If SGX would be disabled, also EREMOVE should fail.
>
> Sorry forgot that in no circumstances we're printing the
> error code inside __sgx_sanitize_pages(). I wrote a quick
> patch to address this (attached) [*].
>
> Paul,
>
> Any chance to try the patch out?

Yes, I am going to try it in the next days.

> It's pretty hard to attach e.g. kprobe to grab this info. Does it
> reproduce every single time?
Yes, on each boot up.

> Alternatively: what kind of workload is triggering this?
> I do own 2020 model XPS13, which might be able to
> reproduce the same issue.

The Dell XPS 13 9370 is from 2018 (Intel i5-8350U), so no idea if it 
happens with later processors.


Kind regards,

Paul


> [*] Also: https://lore.kernel.org/linux-sgx/20220825051827.246698-1-jarkko@xxxxxxxxxx/T/#u