Re: bprm_count and stack_mprotect error when testing BPF LSM on v5.7-rc3

KP Singh
2020-05-09T13:29:02Z

On Sat, May 9, 2020 at 11:59 AM Ma Xinjian <max.xinjian@intel.com> wrote:
>
>
> On 5/9/20 5:26 PM, KP Singh wrote:
> > Do you have bpf in your CONFIG_LSM string?
>
> That's the point!
>
> I remove bpf from since I can't boot if bpf in it.

That does indicate a problem which needs to be fixed.

> seems bpf in CONFIG_LSM conflict with CONFIG_BPF_LSM
>
> Here is boot error:
>
> "Cannot determine cgroup we are running in: No data available
> Failed to allocate manager object: No data available
> [!!!!!!] Failed to allocate manager object, freezing.

I found some references to these error messages and they seem
to be coming from systemd but I am not sure.

https://github.com/lxc/lxc/issues/1669
https://github.com/containers/libpod/issues/1226

> Freezing execution.
> [ 35.773797] random: fast init done
> [ 130.560629] random: crng init done"
>
> > Also, can you share your Kconfig please?
>
> refer to attackment.
>
> I doubt sth was wrong with my kconfig, maybe me some suggestion

I am not saying something is wrong with your Kconfig :)
I just want to make sure we eliminate as many
variables as possible.

I was able to boot this successfully using QEMU
(after I enabled SCSI and VIRTIO). So it's likely
dependent on some user-space configuration
(again, I am not saying your config is wrong). But
I will need more information to reproduce and debug this.

Can you try providing a reliable reproduction with a list
of steps? e.g.

1. Download the vanilla image here.
2. Compile the kernel with defonconfig and kvmconfig
(or your own config)
3. Boot the kernel in QEMU with the cmdline (...) and the
QEMU args (...)

Thanks!
- KP

>
> Besides, I tested on both physical machine and vm

[...]

> >