Slight reorganization of kernel thread/process creation. Instead of using

SYSINIT_KT() etc (which is a static, compile-time procedure), use a
NetBSD-style kthread_create() interface.  kproc_start is still available
as a SYSINIT() hook.  This allowed simplification of chunks of the
sysinit code in the process.  This kthread_create() is our old kproc_start
internals, with the SYSINIT_KT fork hooks grafted in and tweaked to work
the same as the NetBSD one.

One thing I'd like to do shortly is get rid of nfsiod as a user initiated
process.  It makes sense for the nfs client code to create them on the
fly as needed up to a user settable limit.  This means that nfsiod
doesn't need to be in /sbin and is always "available".  This is a fair bit
easier to do outside of the SYSINIT_KT() framework.

1 files changed, 100 insertions, 0 deletions

diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
new file mode 100644
index 0000000..8d8ec00
--- /dev/null
+++ b/sys/kern/kern_kthread.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/kthread.h>
+#include <sys/unistd.h>
+#include <sys/wait.h>
+
+#include <machine/cpu.h>
+#include <machine/stdarg.h>
+
+/*
+ * Start a kernel process.  This is called after a fork() call in
+ * mi_startup() in the file kern/init_main.c.
+ *
+ * This function is used to start "internal" daemons and intended
+ * to be called from SYSINIT().
+ */
+void
+kproc_start(udata)
+	const void *udata;
+{
+	const struct kproc_desc	*kp = udata;
+	int error;
+
+	error = kthread_create((void (*)(void *))kp->func, NULL,
+		    kp->global_procpp, kp->arg0);
+	if (error)
+		panic("kproc_start: %s: error %d", kp->arg0, error);
+}
+
+/*
+ * Create a kernel process/thread/whatever.  It shares it's address space
+ * with proc0 - ie: kernel only.
+ */
+int
+kthread_create(void (*func)(void *), void *arg,
+    struct proc **newpp, const char *fmt, ...)
+{
+	int error;
+	va_list ap;
+	struct proc *p2;
+
+	error = fork1(&proc0, RFMEM | RFFDG | RFPROC, &p2);
+	if (error)
+		return error;
+
+	/* save a global descriptor, if desired */
+	if (newpp != NULL)
+		*newpp = p2;
+
+	/* this is a non-swapped system process */
+	p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT;
+	PHOLD(p2);
+
+	/* set up arg0 for 'ps', et al */
+	va_start(ap, fmt);
+	vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
+	va_end(ap);
+
+	/* call the processes' main()... */
+	cpu_set_fork_handler(p2, func, arg);
+
+	return 0;
+}
+
+void
+kthread_exit(int ecode)
+{
+	exit1(curproc, W_EXITCODE(ecode, 0));
+}
+