dhcpcd-discuss

On 13/11/2020 16:43, Matthew Clarkson wrote:
> Oh I may have spoken too soon. It looks like it is working when I have the 
> master process running with the --nobackground option and use a second ssh 
> connection to dump the lease. This is the output when repeatedly dumping the 
> lease (all the control command messages are  expected):
>
> But if I run the master process with --background and try in the same console 
> there is another seccomp violation. This time it looks like ioctl, which appears 
> to be more granular in the seccomp filter. Is there a way to determine which 
> argument is being used that causes the violation?
>
> root@RCFA-1048515:~# dhcpcd -d --dumplease -4 br0
>
> send OK
>
> ps_seccomp_violation: unexpected syscall 54 (arch=0x40000028)

This looks like the foreground process violating the sandbox.
If it send OK, which it claims, there are zero ioctls dhcpcd makes itself.
If you disable SECCOMP_FILTER_DEBUG, systrace might be able to pinpoint the 
error better.

systrace dhcpcd -d --dumplease -4 br0

For reference, it works fine on amd64 :/

Roy