Index: sys/amd64/amd64/vm_machdep.c
===================================================================
--- sys/amd64/amd64/vm_machdep.c
+++ sys/amd64/amd64/vm_machdep.c
@@ -246,8 +246,10 @@
 	bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
 
 	td2->td_frame->tf_rax = 0;		/* Child returns zero */
-	td2->td_frame->tf_rflags &= ~PSL_C;	/* success */
-	td2->td_frame->tf_rdx = 1;
+	if (SV_PROC_ABI(p2) == SV_ABI_FREEBSD) {
+		td2->td_frame->tf_rflags &= ~PSL_C;	/* success */
+		td2->td_frame->tf_rdx = 1;
+	}
 
 	/*
 	 * If the parent process has the trap bit set (i.e. a debugger
Index: sys/i386/i386/vm_machdep.c
===================================================================
--- sys/i386/i386/vm_machdep.c
+++ sys/i386/i386/vm_machdep.c
@@ -259,8 +259,10 @@
 	bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
 
 	td2->td_frame->tf_eax = 0;		/* Child returns zero */
-	td2->td_frame->tf_eflags &= ~PSL_C;	/* success */
-	td2->td_frame->tf_edx = 1;
+	if (SV_PROC_ABI(p2) == SV_ABI_FREEBSD) {
+		td2->td_frame->tf_eflags &= ~PSL_C;	/* success */
+		td2->td_frame->tf_edx = 1;
+	}
 
 	/*
 	 * If the parent process has the trap bit set (i.e. a debugger