On Tue, Jan 02, 2024 at 11:54:32AM +0100, Thomas Lange wrote:
The root cause is a kernel bug. I have reported it to netdev:
https://lore.kernel.org/netdev/a9090be2-ca7c-494c-89cb-49b1db2438ba@xxxxxxxxxxxx/T/#u
A proper patch has not been committed yet though, but it seems that my
one-line fix should do it according to comments so far.
Interesting. Thanks for looking into it.
AFAICT this bug breaks timestamping via cmsg (i.e. Chrony) for all 32bit
platforms using 64bit time.
Yes, it seems so. I can reproduce it on OpenWrt, now that I know what
to look for.
It doesn't impact all NTP packets. chronyd should not use the cmsg in
server basic mode and both client modes unless the acquisitionport
directive is used.
The cmsg use in chronyd is limited to kernel versions >= 4.8. Maybe we
should extend that up to the current version for the case when 64-bit
time_t is used on a 32-bit arch.