Fault execution flow
Arrows show observed order and instrumented nesting. They do not prove the root cause.
Evidence: limited
Artifact SHA256: 683a017fe00c2cbb418568ea8bc0fdd66457b8e99e971da50a99facdf90bf087
SIGSEGV · TID 674932 / 1
PC: 0x589633536344 · fd_segv
Fault address: 0x7040c5dc4000
Last event (temporal context): thread-0-event-1
TID 674932 / generation 1
Retained: 2; omitted from report: 0; dropped: 0
| Seq | Event | Function | Gap |
|---|---|---|---|
| 0 | enter | main | |
| 1 | enter | fd_segv |
Evidence limits
- {"reason": "capture_completeness_unconfirmed"}
- {"reason": "rpc_capture_incomplete"}
- FD-MISSING-SYMBOL: No unique symbol could be verified for this address.
- FD-INCOMPLETE-TRACE: A retained thread trace has unbalanced enter/exit events; interruption or ring loss may have removed context.
- Recorded order and instrumented nesting do not establish the root cause or a direct call through uninstrumented code.
- The last recorded event before a crash is temporal context, not proof that the event caused the crash.
- Unmatched entries describe retained instrumentation, not an operating-system stack unwind.
- Threads are separated by TID and generation; no cross-thread causality is inferred.
- Static call candidates are kept separate from runtime observations. Source text requires a verified bundle.
Verified source · c:main.c@F@fd_segv
/home/sra235/2026/faultDebugMCP/build/showcase-c-bundle/source/test/programs/signals/main.c:8–8
__attribute__((noinline)) static void fd_segv(void){size_t p=(size_t)sysconf(_SC_PAGESIZE);if(!p)_exit(90);void *x=mmap(0,p,PROT_NONE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0);if(x==MAP_FAILED)_exit(90);volatile char *q=(volatile char*)x;(void)*q;}