2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/cpuset.h>
35 #include <sys/kthread.h>
37 #include <sys/mutex.h>
39 #include <sys/resourcevar.h>
40 #include <sys/rwlock.h>
41 #include <sys/signalvar.h>
44 #include <sys/unistd.h>
46 #include <sys/sched.h>
48 #include <vm/vm_extern.h>
50 #include <machine/stdarg.h>
53 * Start a kernel process. This is called after a fork() call in
54 * mi_startup() in the file kern/init_main.c.
56 * This function is used to start "internal" daemons and intended
57 * to be called from SYSINIT().
60 kproc_start(const void *udata)
62 const struct kproc_desc *kp = udata;
65 error = kproc_create((void (*)(void *))kp->func, NULL,
66 kp->global_procpp, 0, 0, "%s", kp->arg0);
68 panic("kproc_start: %s: error %d", kp->arg0, error);
72 * Create a kernel process/thread/whatever. It shares its address space
73 * with proc0 - ie: kernel only.
75 * func is the function to start.
76 * arg is the parameter to pass to function on first startup.
77 * newpp is the return value pointing to the thread's struct proc.
78 * flags are flags to fork1 (in unistd.h)
79 * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.).
82 kproc_create(void (*func)(void *), void *arg,
83 struct proc **newpp, int flags, int pages, const char *fmt, ...)
92 panic("kproc_create called too soon");
94 bzero(&fr, sizeof(fr));
95 fr.fr_flags = RFMEM | RFFDG | RFPROC | RFSTOPPED | flags;
98 error = fork1(&thread0, &fr);
102 /* save a global descriptor, if desired */
106 /* this is a non-swapped system process */
108 td = FIRST_THREAD_IN_PROC(p2);
109 p2->p_flag |= P_SYSTEM | P_KPROC;
110 td->td_pflags |= TDP_KTHREAD;
111 mtx_lock(&p2->p_sigacts->ps_mtx);
112 p2->p_sigacts->ps_flag |= PS_NOCLDWAIT;
113 mtx_unlock(&p2->p_sigacts->ps_mtx);
116 /* set up arg0 for 'ps', et al */
118 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
120 /* set up arg0 for 'ps', et al */
122 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
125 sched_clear_tdname(td);
128 /* call the processes' main()... */
129 cpu_fork_kthread_handler(td, func, arg);
131 /* Avoid inheriting affinity from a random parent. */
132 cpuset_setthread(td->td_tid, cpuset_root);
136 sched_user_prio(td, PUSER);
138 /* Delay putting it on the run queue until now. */
139 if (!(flags & RFSTOPPED))
140 sched_add(td, SRQ_BORING);
147 kproc_exit(int ecode)
156 * Reparent curthread from proc0 to init so that the zombie
159 sx_xlock(&proctree_lock);
161 proc_reparent(p, initproc);
163 sx_xunlock(&proctree_lock);
166 * Wakeup anyone waiting for us to exit.
175 * Advise a kernel process to suspend (or resume) in its main loop.
176 * Participation is voluntary.
179 kproc_suspend(struct proc *p, int timo)
182 * Make sure this is indeed a system process and we can safely
183 * use the p_siglist field.
186 if ((p->p_flag & P_KPROC) == 0) {
190 SIGADDSET(p->p_siglist, SIGSTOP);
192 return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo);
196 kproc_resume(struct proc *p)
199 * Make sure this is indeed a system process and we can safely
200 * use the p_siglist field.
203 if ((p->p_flag & P_KPROC) == 0) {
207 SIGDELSET(p->p_siglist, SIGSTOP);
209 wakeup(&p->p_siglist);
214 kproc_suspend_check(struct proc *p)
217 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
218 wakeup(&p->p_siglist);
219 msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0);
226 * Start a kernel thread.
228 * This function is used to start "internal" daemons and intended
229 * to be called from SYSINIT().
233 kthread_start(const void *udata)
235 const struct kthread_desc *kp = udata;
238 error = kthread_add((void (*)(void *))kp->func, NULL,
239 NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0);
241 panic("kthread_start: %s: error %d", kp->arg0, error);
245 * Create a kernel thread. It shares its address space
246 * with proc0 - ie: kernel only.
248 * func is the function to start.
249 * arg is the parameter to pass to function on first startup.
250 * newtdp is the return value pointing to the thread's struct thread.
251 * ** XXX fix this --> flags are flags to fork1 (in unistd.h)
252 * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.).
255 kthread_add(void (*func)(void *), void *arg, struct proc *p,
256 struct thread **newtdp, int flags, int pages, const char *fmt, ...)
259 struct thread *newtd, *oldtd;
262 panic("kthread_add called too soon");
264 /* If no process supplied, put it on proc0 */
268 /* Initialize our new td */
269 newtd = thread_alloc(pages);
274 oldtd = FIRST_THREAD_IN_PROC(p);
276 bzero(&newtd->td_startzero,
277 __rangeof(struct thread, td_startzero, td_endzero));
278 bcopy(&oldtd->td_startcopy, &newtd->td_startcopy,
279 __rangeof(struct thread, td_startcopy, td_endcopy));
281 /* set up arg0 for 'ps', et al */
283 vsnprintf(newtd->td_name, sizeof(newtd->td_name), fmt, ap);
286 newtd->td_proc = p; /* needed for cpu_copy_thread */
287 /* might be further optimized for kthread */
288 cpu_copy_thread(newtd, oldtd);
289 /* put the designated function(arg) as the resume context */
290 cpu_fork_kthread_handler(newtd, func, arg);
292 newtd->td_pflags |= TDP_KTHREAD;
293 thread_cow_get_proc(newtd, p);
295 /* this code almost the same as create_thread() in kern_thr.c */
296 p->p_flag |= P_HADTHREADS;
297 thread_link(newtd, p);
299 /* let the scheduler know about these things. */
300 sched_fork_thread(oldtd, newtd);
301 TD_SET_CAN_RUN(newtd);
302 thread_unlock(oldtd);
307 /* Avoid inheriting affinity from a random parent. */
308 cpuset_setthread(newtd->td_tid, cpuset_root);
310 /* Delay putting it on the run queue until now. */
311 if (!(flags & RFSTOPPED)) {
313 sched_add(newtd, SRQ_BORING);
314 thread_unlock(newtd);
330 /* A module may be waiting for us to exit. */
334 * The last exiting thread in a kernel process must tear down
337 rw_wlock(&tidhash_lock);
339 if (p->p_numthreads == 1) {
341 rw_wunlock(&tidhash_lock);
344 LIST_REMOVE(td, td_hash);
345 rw_wunlock(&tidhash_lock);
346 umtx_thread_exit(td);
353 * Advise a kernel process to suspend (or resume) in its main loop.
354 * Participation is voluntary.
357 kthread_suspend(struct thread *td, int timo)
364 * td_pflags should not be read by any thread other than
365 * curthread, but as long as this flag is invariant during the
366 * thread's lifetime, it is OK to check its state.
368 if ((td->td_pflags & TDP_KTHREAD) == 0)
372 * The caller of the primitive should have already checked that the
373 * thread is up and running, thus not being blocked by other
378 td->td_flags |= TDF_KTH_SUSP;
380 return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt",
385 * Resume a thread previously put asleep with kthread_suspend().
388 kthread_resume(struct thread *td)
395 * td_pflags should not be read by any thread other than
396 * curthread, but as long as this flag is invariant during the
397 * thread's lifetime, it is OK to check its state.
399 if ((td->td_pflags & TDP_KTHREAD) == 0)
404 td->td_flags &= ~TDF_KTH_SUSP;
406 wakeup(&td->td_flags);
412 * Used by the thread to poll as to whether it should yield/sleep
413 * and notify the caller that is has happened.
416 kthread_suspend_check(void)
424 if ((td->td_pflags & TDP_KTHREAD) == 0)
425 panic("%s: curthread is not a valid kthread", __func__);
428 * As long as the double-lock protection is used when accessing the
429 * TDF_KTH_SUSP flag, synchronizing the read operation via proc mutex
433 while (td->td_flags & TDF_KTH_SUSP) {
434 wakeup(&td->td_flags);
435 msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0);
441 kproc_kthread_add(void (*func)(void *), void *arg,
442 struct proc **procptr, struct thread **tdptr,
443 int flags, int pages, const char *procname, const char *fmt, ...)
450 if (*procptr == NULL) {
451 error = kproc_create(func, arg,
452 procptr, flags, pages, "%s", procname);
455 td = FIRST_THREAD_IN_PROC(*procptr);
459 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
462 sched_clear_tdname(td);
467 vsnprintf(buf, sizeof(buf), fmt, ap);
469 error = kthread_add(func, arg, *procptr,
470 tdptr, flags, pages, "%s", buf);