D457 - A fault report names the register most likely holding the null base of the access

Status: decided Date: 2026-09-01

On a fault whose address is at or near zero, the report names the specific register whose value, plus a small field offset, produced the fault address, preferring a register that is exactly zero over one that only matches by coincidence.

Why: The full register dump already exists, but which register was the null pointer was left for a reader to work out by matching values against the fault address by hand. An exactly-zero register is a genuine null dereference; a near-zero coincidental match is excluded so the report does not mislead. A fault far from address zero names nothing.

Rejected: naming any register whose arithmetic happens to match the fault address - produces false leads from coincidental matches.