Files
psxrecomp/runtime/include
Matthew Stanley cf87fd8fc6 crash_trace: structured post-mortem dump (mirrors SMW recomp pattern)
New runtime/src/crash_trace.c writes psx_last_run_report.json with:
  reason / timestamp / frame / last_func_addr / last_store_pc
  full CPU register state (all 32 GPRs + hi/lo/sr/cause/epc)
  dispatch_ring tail (last 256 dispatched func entries)
  unknown_dispatch tail (last 50 entries with addr/phys/ra/a0/a1)
  dirty_block_log tail (last 100 entries)
  Windows SEH info (when triggered from SEH filter)

Triggered from:
  - SIGSEGV / SIGABRT signal handlers
  - Windows SetUnhandledExceptionFilter (catches access violations)
  - atexit
  - psx_unknown_dispatch fail-fast path (set PSX_FAIL_FAST_UNKNOWN_DISPATCH=1)
  - trap_crash (existing fatal trap path)

File overwrites per dump (last-write-wins). Per CLAUDE.md §3 this is not
a log — it's a one-shot final state snapshot for crashes the running
TCP server cannot intercept.

Pattern mirrors F:/Projects/SuperMarioWorldRecomp/src/post_mortem.c.

Used the new infrastructure to capture a controlled crash with
0xBFC0989C re-seeded. Crash dump revealed the chain:
  - JAL at 0xBFC09788 is jalr $s3, NOT jalr $a0
  - $s3 was set in func_1FC09598 prologue: $s3 = $a2 (callee saves arg)
  - Caller at 0xBFC093C4 in func_1FC092EC: $a2 = $s3 - 128 (delay slot)
  - func_1FC092EC at 0xBFC09314: $s3 = $a3 (callee saves arg)
  So real bug is upstream-of-upstream caller passing $a3 = 131 (0x83)
  to func_1FC092EC, propagating down to a misaligned function pointer.
  The 0xA000E1E8 we suspected as a function-pointer table was a
  red herring — $a0 in the loop body is loaded from $fp+s1*4 (the
  ARG to pass to the called fn), not the call target.

0xBFC0989C reverted out of seed list (was diagnostic-only).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-05 23:45:33 -07:00
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