>This should be resolved with the lastest mips_machdep.c.  I will
>double check the flushing path you describe, it may only actually
>be needed on writeback cache machines.

But why is the cache flush needed in setregs() and pmap_procwr() is
not enough?

in kern_exec.c:

	...

	/* copy out the process's signal trapoline code */
	if (szsigcode) {
		if (copyout((char *)pack.ep_emul->e_sigcode,
		    p->p_sigacts->ps_sigcode = (char *)PS_STRINGS - szsigcode,
		    szsigcode)) {
#ifdef DEBUG
			printf("execve: sig trampoline copyout failed\n");
#endif
			goto exec_abort;
		}
#ifdef PMAP_NEED_PROCWR
		/* This is code. Let the pmap do what is needed. */
		pmap_procwr(p, (vaddr_t)p->p_sigacts->ps_sigcode, szsigcode);
#endif
	}