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>
47 #include <sys/tslog.h>
49 #include <vm/vm_extern.h>
51 #include <machine/stdarg.h>
54 * Start a kernel process. This is called after a fork() call in
55 * mi_startup() in the file kern/init_main.c.
57 * This function is used to start "internal" daemons and intended
58 * to be called from SYSINIT().
61 kproc_start(const void *udata)
63 const struct kproc_desc *kp = udata;
66 error = kproc_create((void (*)(void *))kp->func, NULL,
67 kp->global_procpp, 0, 0, "%s", kp->arg0);
69 panic("kproc_start: %s: error %d", kp->arg0, error);
73 * Create a kernel process/thread/whatever. It shares its address space
74 * with proc0 - ie: kernel only.
76 * func is the function to start.
77 * arg is the parameter to pass to function on first startup.
78 * newpp is the return value pointing to the thread's struct proc.
79 * flags are flags to fork1 (in unistd.h)
80 * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.).
83 kproc_create(void (*func)(void *), void *arg,
84 struct proc **newpp, int flags, int pages, const char *fmt, ...)
93 panic("kproc_create called too soon");
95 bzero(&fr, sizeof(fr));
96 fr.fr_flags = RFMEM | RFFDG | RFPROC | RFSTOPPED | flags;
99 error = fork1(&thread0, &fr);
103 /* save a global descriptor, if desired */
107 /* this is a non-swapped system process */
109 td = FIRST_THREAD_IN_PROC(p2);
110 p2->p_flag |= P_SYSTEM | P_KPROC;
111 td->td_pflags |= TDP_KTHREAD;
112 mtx_lock(&p2->p_sigacts->ps_mtx);
113 p2->p_sigacts->ps_flag |= PS_NOCLDWAIT;
114 mtx_unlock(&p2->p_sigacts->ps_mtx);
117 /* set up arg0 for 'ps', et al */
119 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
121 /* set up arg0 for 'ps', et al */
123 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
126 sched_clear_tdname(td);
128 TSTHREAD(td, td->td_name);
130 /* call the processes' main()... */
131 cpu_fork_kthread_handler(td, func, arg);
133 /* Avoid inheriting affinity from a random parent. */
134 cpuset_setthread(td->td_tid, cpuset_root);
138 sched_user_prio(td, PUSER);
140 /* Delay putting it on the run queue until now. */
141 if (!(flags & RFSTOPPED))
142 sched_add(td, SRQ_BORING);
149 kproc_exit(int ecode)
158 * Reparent curthread from proc0 to init so that the zombie
161 sx_xlock(&proctree_lock);
163 proc_reparent(p, initproc);
165 sx_xunlock(&proctree_lock);
168 * Wakeup anyone waiting for us to exit.
177 * Advise a kernel process to suspend (or resume) in its main loop.
178 * Participation is voluntary.
181 kproc_suspend(struct proc *p, int timo)
184 * Make sure this is indeed a system process and we can safely
185 * use the p_siglist field.
188 if ((p->p_flag & P_KPROC) == 0) {
192 SIGADDSET(p->p_siglist, SIGSTOP);
194 return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo);
198 kproc_resume(struct proc *p)
201 * Make sure this is indeed a system process and we can safely
202 * use the p_siglist field.
205 if ((p->p_flag & P_KPROC) == 0) {
209 SIGDELSET(p->p_siglist, SIGSTOP);
211 wakeup(&p->p_siglist);
216 kproc_suspend_check(struct proc *p)
219 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
220 wakeup(&p->p_siglist);
221 msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0);
228 * Start a kernel thread.
230 * This function is used to start "internal" daemons and intended
231 * to be called from SYSINIT().
235 kthread_start(const void *udata)
237 const struct kthread_desc *kp = udata;
240 error = kthread_add((void (*)(void *))kp->func, NULL,
241 NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0);
243 panic("kthread_start: %s: error %d", kp->arg0, error);
247 * Create a kernel thread. It shares its address space
248 * with proc0 - ie: kernel only.
250 * func is the function to start.
251 * arg is the parameter to pass to function on first startup.
252 * newtdp is the return value pointing to the thread's struct thread.
253 * ** XXX fix this --> flags are flags to fork1 (in unistd.h)
254 * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.).
257 kthread_add(void (*func)(void *), void *arg, struct proc *p,
258 struct thread **newtdp, int flags, int pages, const char *fmt, ...)
261 struct thread *newtd, *oldtd;
264 panic("kthread_add called too soon");
266 /* If no process supplied, put it on proc0 */
270 /* Initialize our new td */
271 newtd = thread_alloc(pages);
276 oldtd = FIRST_THREAD_IN_PROC(p);
278 bzero(&newtd->td_startzero,
279 __rangeof(struct thread, td_startzero, td_endzero));
280 bcopy(&oldtd->td_startcopy, &newtd->td_startcopy,
281 __rangeof(struct thread, td_startcopy, td_endcopy));
283 /* set up arg0 for 'ps', et al */
285 vsnprintf(newtd->td_name, sizeof(newtd->td_name), fmt, ap);
288 TSTHREAD(newtd, newtd->td_name);
290 newtd->td_proc = p; /* needed for cpu_copy_thread */
291 /* might be further optimized for kthread */
292 cpu_copy_thread(newtd, oldtd);
293 /* put the designated function(arg) as the resume context */
294 cpu_fork_kthread_handler(newtd, func, arg);
296 newtd->td_pflags |= TDP_KTHREAD;
297 thread_cow_get_proc(newtd, p);
299 /* this code almost the same as create_thread() in kern_thr.c */
300 p->p_flag |= P_HADTHREADS;
301 thread_link(newtd, p);
303 /* let the scheduler know about these things. */
304 sched_fork_thread(oldtd, newtd);
305 TD_SET_CAN_RUN(newtd);
306 thread_unlock(oldtd);
311 /* Avoid inheriting affinity from a random parent. */
312 cpuset_setthread(newtd->td_tid, cpuset_root);
314 /* Delay putting it on the run queue until now. */
315 if (!(flags & RFSTOPPED)) {
317 sched_add(newtd, SRQ_BORING);
318 thread_unlock(newtd);
334 /* A module may be waiting for us to exit. */
338 * The last exiting thread in a kernel process must tear down
341 rw_wlock(&tidhash_lock);
343 if (p->p_numthreads == 1) {
345 rw_wunlock(&tidhash_lock);
348 LIST_REMOVE(td, td_hash);
349 rw_wunlock(&tidhash_lock);
350 umtx_thread_exit(td);
357 * Advise a kernel process to suspend (or resume) in its main loop.
358 * Participation is voluntary.
361 kthread_suspend(struct thread *td, int timo)
368 * td_pflags should not be read by any thread other than
369 * curthread, but as long as this flag is invariant during the
370 * thread's lifetime, it is OK to check its state.
372 if ((td->td_pflags & TDP_KTHREAD) == 0)
376 * The caller of the primitive should have already checked that the
377 * thread is up and running, thus not being blocked by other
382 td->td_flags |= TDF_KTH_SUSP;
384 return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt",
389 * Resume a thread previously put asleep with kthread_suspend().
392 kthread_resume(struct thread *td)
399 * td_pflags should not be read by any thread other than
400 * curthread, but as long as this flag is invariant during the
401 * thread's lifetime, it is OK to check its state.
403 if ((td->td_pflags & TDP_KTHREAD) == 0)
408 td->td_flags &= ~TDF_KTH_SUSP;
410 wakeup(&td->td_flags);
416 * Used by the thread to poll as to whether it should yield/sleep
417 * and notify the caller that is has happened.
420 kthread_suspend_check(void)
428 if ((td->td_pflags & TDP_KTHREAD) == 0)
429 panic("%s: curthread is not a valid kthread", __func__);
432 * As long as the double-lock protection is used when accessing the
433 * TDF_KTH_SUSP flag, synchronizing the read operation via proc mutex
437 while (td->td_flags & TDF_KTH_SUSP) {
438 wakeup(&td->td_flags);
439 msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0);
445 kproc_kthread_add(void (*func)(void *), void *arg,
446 struct proc **procptr, struct thread **tdptr,
447 int flags, int pages, const char *procname, const char *fmt, ...)
454 if (*procptr == NULL) {
455 error = kproc_create(func, arg,
456 procptr, flags, pages, "%s", procname);
459 td = FIRST_THREAD_IN_PROC(*procptr);
463 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
466 sched_clear_tdname(td);
471 vsnprintf(buf, sizeof(buf), fmt, ap);
473 error = kthread_add(func, arg, *procptr,
474 tdptr, flags, pages, "%s", buf);