We're running into incomplete backtraces reported by libunwind where a faulting address is in the VDSO memory mapping. We suspect the issue may simply be incomplete support for VDSO in libunwind. The following PRs may help improve support to resolve these issues:

• https://github.com/libunwind/libunwind/pull/728
• https://github.com/libunwind/libunwind/pull/658

Once one or both of these make it into a libunwind release, we should consider upgrading to see if the issue gets resolved. Alternatively, we might consider backporting one or both of those to our vendored copy of libunwind as soon as they make it into the libunwind mainline.