Symbol: UMTX_OP_ROBUST_LISTS
lib/libthr/thread/thr_mutex.c
232
_umtx_op(NULL, UMTX_OP_ROBUST_LISTS, sizeof(rb), &rb, NULL);
sys/kern/kern_umtx.c
4936
[UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists,