The talk at the FOSDEM conference was about walking native stacks in BPF without frame pointers. The speakers discussed the need for a dwarf-based stack walker in eBPF and then went into the design and implementation of the stack walker. They talked about using the EH frame section in BPF maps to store the unwind information and how they used sharding to handle larger unwind tables. They also mentioned some challenges they faced, such as limited stack space in BPF and the limitations of Go APIs. They highlighted the importance of testing and the use of snapshot testing to catch bugs. The speakers mentioned some production challenges they encountered and how they overcame them. They also discussed future plans to add support for high-level languages and the open-source nature of their project.