2 * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kthread.h>
34 #include <sys/mutex.h>
36 #include <sys/resourcevar.h>
37 #include <sys/rwlock.h>
38 #include <sys/signalvar.h>
40 #include <sys/unistd.h>
42 #include <sys/sched.h>
44 #include <vm/vm_extern.h>
46 #include <machine/stdarg.h>
49 * Start a kernel process. This is called after a fork() call in
50 * mi_startup() in the file kern/init_main.c.
52 * This function is used to start "internal" daemons and intended
53 * to be called from SYSINIT().
59 const struct kproc_desc *kp = udata;
62 error = kproc_create((void (*)(void *))kp->func, NULL,
63 kp->global_procpp, 0, 0, "%s", kp->arg0);
65 panic("kproc_start: %s: error %d", kp->arg0, error);
69 * Create a kernel process/thread/whatever. It shares its address space
70 * with proc0 - ie: kernel only.
72 * func is the function to start.
73 * arg is the parameter to pass to function on first startup.
74 * newpp is the return value pointing to the thread's struct proc.
75 * flags are flags to fork1 (in unistd.h)
76 * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.).
79 kproc_create(void (*func)(void *), void *arg,
80 struct proc **newpp, int flags, int pages, const char *fmt, ...)
88 panic("kproc_create called too soon");
90 error = fork1(&thread0, RFMEM | RFFDG | RFPROC | RFSTOPPED | flags,
95 /* save a global descriptor, if desired */
99 /* this is a non-swapped system process */
101 td = FIRST_THREAD_IN_PROC(p2);
102 p2->p_flag |= P_SYSTEM | P_KTHREAD;
103 td->td_pflags |= TDP_KTHREAD;
104 mtx_lock(&p2->p_sigacts->ps_mtx);
105 p2->p_sigacts->ps_flag |= PS_NOCLDWAIT;
106 mtx_unlock(&p2->p_sigacts->ps_mtx);
109 /* set up arg0 for 'ps', et al */
111 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
113 /* set up arg0 for 'ps', et al */
115 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
118 /* call the processes' main()... */
119 cpu_set_fork_handler(td, func, arg);
123 sched_user_prio(td, PUSER);
125 /* Delay putting it on the run queue until now. */
126 if (!(flags & RFSTOPPED))
127 sched_add(td, SRQ_BORING);
134 kproc_exit(int ecode)
143 * Reparent curthread from proc0 to init so that the zombie
146 sx_xlock(&proctree_lock);
148 proc_reparent(p, initproc);
150 sx_xunlock(&proctree_lock);
153 * Wakeup anyone waiting for us to exit.
158 exit1(td, W_EXITCODE(ecode, 0));
162 * Advise a kernel process to suspend (or resume) in its main loop.
163 * Participation is voluntary.
166 kproc_suspend(struct proc *p, int timo)
169 * Make sure this is indeed a system process and we can safely
170 * use the p_siglist field.
173 if ((p->p_flag & P_KTHREAD) == 0) {
177 SIGADDSET(p->p_siglist, SIGSTOP);
179 return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo);
183 kproc_resume(struct proc *p)
186 * Make sure this is indeed a system process and we can safely
187 * use the p_siglist field.
190 if ((p->p_flag & P_KTHREAD) == 0) {
194 SIGDELSET(p->p_siglist, SIGSTOP);
196 wakeup(&p->p_siglist);
201 kproc_suspend_check(struct proc *p)
204 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
205 wakeup(&p->p_siglist);
206 msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0);
213 * Start a kernel thread.
215 * This function is used to start "internal" daemons and intended
216 * to be called from SYSINIT().
223 const struct kthread_desc *kp = udata;
226 error = kthread_add((void (*)(void *))kp->func, NULL,
227 NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0);
229 panic("kthread_start: %s: error %d", kp->arg0, error);
233 * Create a kernel thread. It shares its address space
234 * with proc0 - ie: kernel only.
236 * func is the function to start.
237 * arg is the parameter to pass to function on first startup.
238 * newtdp is the return value pointing to the thread's struct thread.
239 * ** XXX fix this --> flags are flags to fork1 (in unistd.h)
240 * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.).
243 kthread_add(void (*func)(void *), void *arg, struct proc *p,
244 struct thread **newtdp, int flags, int pages, const char *fmt, ...)
247 struct thread *newtd, *oldtd;
250 panic("kthread_add called too soon");
252 /* If no process supplied, put it on proc0 */
257 oldtd = FIRST_THREAD_IN_PROC(p);
260 /* Initialize our new td */
261 newtd = thread_alloc(pages);
265 bzero(&newtd->td_startzero,
266 __rangeof(struct thread, td_startzero, td_endzero));
267 /* XXX check if we should zero. */
268 bcopy(&oldtd->td_startcopy, &newtd->td_startcopy,
269 __rangeof(struct thread, td_startcopy, td_endcopy));
271 /* set up arg0 for 'ps', et al */
273 vsnprintf(newtd->td_name, sizeof(newtd->td_name), fmt, ap);
276 newtd->td_proc = p; /* needed for cpu_set_upcall */
278 /* XXX optimise this probably? */
279 /* On x86 (and probably the others too) it is way too full of junk */
280 /* Needs a better name */
281 cpu_set_upcall(newtd, oldtd);
282 /* put the designated function(arg) as the resume context */
283 cpu_set_fork_handler(newtd, func, arg);
285 newtd->td_pflags |= TDP_KTHREAD;
286 newtd->td_ucred = crhold(p->p_ucred);
288 /* this code almost the same as create_thread() in kern_thr.c */
290 p->p_flag |= P_HADTHREADS;
291 newtd->td_sigmask = oldtd->td_sigmask; /* XXX dubious */
292 thread_link(newtd, p);
294 /* let the scheduler know about these things. */
295 sched_fork_thread(oldtd, newtd);
296 TD_SET_CAN_RUN(newtd);
297 thread_unlock(oldtd);
302 /* Delay putting it on the run queue until now. */
303 if (!(flags & RFSTOPPED)) {
305 sched_add(newtd, SRQ_BORING);
306 thread_unlock(newtd);
318 p = curthread->td_proc;
320 /* A module may be waiting for us to exit. */
324 * The last exiting thread in a kernel process must tear down
327 rw_wlock(&tidhash_lock);
329 if (p->p_numthreads == 1) {
331 rw_wunlock(&tidhash_lock);
334 LIST_REMOVE(curthread, td_hash);
335 rw_wunlock(&tidhash_lock);
341 * Advise a kernel process to suspend (or resume) in its main loop.
342 * Participation is voluntary.
345 kthread_suspend(struct thread *td, int timo)
352 * td_pflags should not be read by any thread other than
353 * curthread, but as long as this flag is invariant during the
354 * thread's lifetime, it is OK to check its state.
356 if ((td->td_pflags & TDP_KTHREAD) == 0)
360 * The caller of the primitive should have already checked that the
361 * thread is up and running, thus not being blocked by other
366 td->td_flags |= TDF_KTH_SUSP;
368 return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt",
373 * Resume a thread previously put asleep with kthread_suspend().
376 kthread_resume(struct thread *td)
383 * td_pflags should not be read by any thread other than
384 * curthread, but as long as this flag is invariant during the
385 * thread's lifetime, it is OK to check its state.
387 if ((td->td_pflags & TDP_KTHREAD) == 0)
392 td->td_flags &= ~TDF_KTH_SUSP;
394 wakeup(&td->td_flags);
400 * Used by the thread to poll as to whether it should yield/sleep
401 * and notify the caller that is has happened.
404 kthread_suspend_check()
412 if ((td->td_pflags & TDP_KTHREAD) == 0)
413 panic("%s: curthread is not a valid kthread", __func__);
416 * As long as the double-lock protection is used when accessing the
417 * TDF_KTH_SUSP flag, synchronizing the read operation via proc mutex
421 while (td->td_flags & TDF_KTH_SUSP) {
422 wakeup(&td->td_flags);
423 msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0);
429 kproc_kthread_add(void (*func)(void *), void *arg,
430 struct proc **procptr, struct thread **tdptr,
431 int flags, int pages, const char *procname, const char *fmt, ...)
439 error = kproc_create(func, arg,
440 procptr, flags, pages, "%s", procname);
443 td = FIRST_THREAD_IN_PROC(*procptr);
447 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
452 vsnprintf(buf, sizeof(buf), fmt, ap);
454 error = kthread_add(func, arg, *procptr,
455 tdptr, flags, pages, "%s", buf);