2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/cpuset.h>
33 #include <sys/kthread.h>
35 #include <sys/mutex.h>
37 #include <sys/resourcevar.h>
38 #include <sys/rwlock.h>
39 #include <sys/signalvar.h>
40 #include <sys/sysent.h>
42 #include <sys/umtxvar.h>
43 #include <sys/unistd.h>
45 #include <sys/sched.h>
46 #include <sys/tslog.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;
96 fr.fr_flags2 = FR2_KPROC;
99 error = fork1(&thread0, &fr);
103 /* save a global descriptor, if desired */
107 /* set up arg0 for 'ps', et al */
109 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
111 td = FIRST_THREAD_IN_PROC(p2);
113 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
116 sched_clear_tdname(td);
118 TSTHREAD(td, td->td_name);
120 if (PMC_SYSTEM_SAMPLING_ACTIVE()) {
121 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_PROC_CREATE_LOG, p2);
122 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_CREATE_LOG, NULL);
126 /* call the processes' main()... */
127 cpu_fork_kthread_handler(td, func, arg);
129 /* Avoid inheriting affinity from a random parent. */
130 cpuset_kernthread(td);
134 sched_user_prio(td, PUSER);
136 /* Delay putting it on the run queue until now. */
137 if (!(flags & RFSTOPPED))
138 sched_add(td, SRQ_BORING);
146 kproc_exit(int ecode)
155 * Reparent curthread from proc0 to init so that the zombie
158 sx_xlock(&proctree_lock);
160 proc_reparent(p, initproc, true);
162 sx_xunlock(&proctree_lock);
165 * Wakeup anyone waiting for us to exit.
174 * Advise a kernel process to suspend (or resume) in its main loop.
175 * Participation is voluntary.
178 kproc_suspend(struct proc *p, int timo)
181 * Make sure this is indeed a system process and we can safely
182 * use the p_siglist field.
185 if ((p->p_flag & P_KPROC) == 0) {
189 SIGADDSET(p->p_siglist, SIGSTOP);
191 return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo);
195 kproc_resume(struct proc *p)
198 * Make sure this is indeed a system process and we can safely
199 * use the p_siglist field.
202 if ((p->p_flag & P_KPROC) == 0) {
206 SIGDELSET(p->p_siglist, SIGSTOP);
208 wakeup(&p->p_siglist);
213 kproc_suspend_check(struct proc *p)
216 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
217 wakeup(&p->p_siglist);
218 msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0);
224 * Start a kernel thread.
226 * This function is used to start "internal" daemons and intended
227 * to be called from SYSINIT().
231 kthread_start(const void *udata)
233 const struct kthread_desc *kp = udata;
236 error = kthread_add((void (*)(void *))kp->func, NULL,
237 NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0);
239 panic("kthread_start: %s: error %d", kp->arg0, error);
243 * Create a kernel thread. It shares its address space
244 * with proc0 - ie: kernel only.
246 * func is the function to start.
247 * arg is the parameter to pass to function on first startup.
248 * newtdp is the return value pointing to the thread's struct thread.
249 * ** XXX fix this --> flags are flags to fork1 (in unistd.h)
250 * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.).
253 kthread_add(void (*func)(void *), void *arg, struct proc *p,
254 struct thread **newtdp, int flags, int pages, const char *fmt, ...)
257 struct thread *newtd, *oldtd;
260 panic("kthread_add called too soon");
262 /* If no process supplied, put it on proc0 */
266 /* Initialize our new td */
267 newtd = thread_alloc(pages);
272 oldtd = FIRST_THREAD_IN_PROC(p);
274 bzero(&newtd->td_startzero,
275 __rangeof(struct thread, td_startzero, td_endzero));
276 bcopy(&oldtd->td_startcopy, &newtd->td_startcopy,
277 __rangeof(struct thread, td_startcopy, td_endcopy));
279 /* set up arg0 for 'ps', et al */
281 vsnprintf(newtd->td_name, sizeof(newtd->td_name), fmt, ap);
284 TSTHREAD(newtd, newtd->td_name);
286 newtd->td_proc = p; /* needed for cpu_copy_thread */
287 newtd->td_pflags |= TDP_KTHREAD;
289 /* might be further optimized for kthread */
290 cpu_copy_thread(newtd, oldtd);
292 /* put the designated function(arg) as the resume context */
293 cpu_fork_kthread_handler(newtd, func, arg);
295 thread_cow_get_proc(newtd, p);
297 /* This code is similar to thread_create() in kern_thr.c. */
298 p->p_flag |= P_HADTHREADS;
299 thread_link(newtd, p);
301 /* let the scheduler know about these things. */
302 sched_fork_thread(oldtd, newtd);
303 TD_SET_CAN_RUN(newtd);
304 thread_unlock(oldtd);
309 /* Avoid inheriting affinity from a random parent. */
310 cpuset_kernthread(newtd);
312 if (PMC_SYSTEM_SAMPLING_ACTIVE())
313 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_CREATE_LOG, NULL);
315 /* Delay putting it on the run queue until now. */
316 if (!(flags & RFSTOPPED)) {
318 sched_add(newtd, SRQ_BORING);
335 if (PMC_SYSTEM_SAMPLING_ACTIVE())
336 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_EXIT_LOG, NULL);
338 /* A module may be waiting for us to exit. */
342 * The last exiting thread in a kernel process must tear down
346 if (p->p_numthreads == 1) {
351 if (p->p_sysent->sv_ontdexit != NULL)
352 p->p_sysent->sv_ontdexit(td);
355 umtx_thread_exit(td);
362 * Advise a kernel process to suspend (or resume) in its main loop.
363 * Participation is voluntary.
366 kthread_suspend(struct thread *td, int timo)
373 * td_pflags should not be read by any thread other than
374 * curthread, but as long as this flag is invariant during the
375 * thread's lifetime, it is OK to check its state.
377 if ((td->td_pflags & TDP_KTHREAD) == 0)
381 * The caller of the primitive should have already checked that the
382 * thread is up and running, thus not being blocked by other
387 td->td_flags |= TDF_KTH_SUSP;
389 return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt",
394 * Resume a thread previously put asleep with kthread_suspend().
397 kthread_resume(struct thread *td)
404 * td_pflags should not be read by any thread other than
405 * curthread, but as long as this flag is invariant during the
406 * thread's lifetime, it is OK to check its state.
408 if ((td->td_pflags & TDP_KTHREAD) == 0)
413 td->td_flags &= ~TDF_KTH_SUSP;
415 wakeup(&td->td_flags);
421 * Used by the thread to poll as to whether it should yield/sleep
422 * and notify the caller that is has happened.
425 kthread_suspend_check(void)
433 if ((td->td_pflags & TDP_KTHREAD) == 0)
434 panic("%s: curthread is not a valid kthread", __func__);
437 * Setting the TDF_KTH_SUSP flag is protected by process lock.
439 * Do an unlocked read first to avoid serializing with all other threads
440 * in the common case of not suspending.
442 if ((td->td_flags & TDF_KTH_SUSP) == 0)
445 while ((td->td_flags & TDF_KTH_SUSP) != 0) {
446 wakeup(&td->td_flags);
447 msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0);
453 kproc_kthread_add(void (*func)(void *), void *arg,
454 struct proc **procptr, struct thread **tdptr,
455 int flags, int pages, const char *procname, const char *fmt, ...)
462 if (*procptr == NULL) {
463 error = kproc_create(func, arg,
464 procptr, flags, pages, "%s", procname);
467 td = FIRST_THREAD_IN_PROC(*procptr);
471 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
474 sched_clear_tdname(td);
479 vsnprintf(buf, sizeof(buf), fmt, ap);
481 error = kthread_add(func, arg, *procptr,
482 tdptr, flags, pages, "%s", buf);