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/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>
42 #include <sys/unistd.h>
44 #include <sys/sched.h>
46 #include <vm/vm_extern.h>
48 #include <machine/stdarg.h>
51 * Start a kernel process. This is called after a fork() call in
52 * mi_startup() in the file kern/init_main.c.
54 * This function is used to start "internal" daemons and intended
55 * to be called from SYSINIT().
61 const struct kproc_desc *kp = udata;
64 error = kproc_create((void (*)(void *))kp->func, NULL,
65 kp->global_procpp, 0, 0, "%s", kp->arg0);
67 panic("kproc_start: %s: error %d", kp->arg0, error);
71 * Create a kernel process/thread/whatever. It shares its address space
72 * with proc0 - ie: kernel only.
74 * func is the function to start.
75 * arg is the parameter to pass to function on first startup.
76 * newpp is the return value pointing to the thread's struct proc.
77 * flags are flags to fork1 (in unistd.h)
78 * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.).
81 kproc_create(void (*func)(void *), void *arg,
82 struct proc **newpp, int flags, int pages, const char *fmt, ...)
90 panic("kproc_create called too soon");
92 error = fork1(&thread0, RFMEM | RFFDG | RFPROC | RFSTOPPED | flags,
97 /* save a global descriptor, if desired */
101 /* this is a non-swapped system process */
103 td = FIRST_THREAD_IN_PROC(p2);
104 p2->p_flag |= P_SYSTEM | P_KTHREAD;
105 td->td_pflags |= TDP_KTHREAD;
106 mtx_lock(&p2->p_sigacts->ps_mtx);
107 p2->p_sigacts->ps_flag |= PS_NOCLDWAIT;
108 mtx_unlock(&p2->p_sigacts->ps_mtx);
111 /* set up arg0 for 'ps', et al */
113 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
115 /* set up arg0 for 'ps', et al */
117 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
120 sched_clear_tdname(td);
123 /* call the processes' main()... */
124 cpu_set_fork_handler(td, func, arg);
126 /* Avoid inheriting affinity from a random parent. */
127 cpuset_setthread(td->td_tid, cpuset_root);
131 sched_user_prio(td, PUSER);
133 /* Delay putting it on the run queue until now. */
134 if (!(flags & RFSTOPPED))
135 sched_add(td, SRQ_BORING);
142 kproc_exit(int ecode)
151 * Reparent curthread from proc0 to init so that the zombie
154 sx_xlock(&proctree_lock);
156 proc_reparent(p, initproc);
158 sx_xunlock(&proctree_lock);
161 * Wakeup anyone waiting for us to exit.
166 exit1(td, W_EXITCODE(ecode, 0));
170 * Advise a kernel process to suspend (or resume) in its main loop.
171 * Participation is voluntary.
174 kproc_suspend(struct proc *p, int timo)
177 * Make sure this is indeed a system process and we can safely
178 * use the p_siglist field.
181 if ((p->p_flag & P_KTHREAD) == 0) {
185 SIGADDSET(p->p_siglist, SIGSTOP);
187 return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo);
191 kproc_resume(struct proc *p)
194 * Make sure this is indeed a system process and we can safely
195 * use the p_siglist field.
198 if ((p->p_flag & P_KTHREAD) == 0) {
202 SIGDELSET(p->p_siglist, SIGSTOP);
204 wakeup(&p->p_siglist);
209 kproc_suspend_check(struct proc *p)
212 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
213 wakeup(&p->p_siglist);
214 msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0);
221 * Start a kernel thread.
223 * This function is used to start "internal" daemons and intended
224 * to be called from SYSINIT().
231 const struct kthread_desc *kp = udata;
234 error = kthread_add((void (*)(void *))kp->func, NULL,
235 NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0);
237 panic("kthread_start: %s: error %d", kp->arg0, error);
241 * Create a kernel thread. It shares its address space
242 * with proc0 - ie: kernel only.
244 * func is the function to start.
245 * arg is the parameter to pass to function on first startup.
246 * newtdp is the return value pointing to the thread's struct thread.
247 * ** XXX fix this --> flags are flags to fork1 (in unistd.h)
248 * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.).
251 kthread_add(void (*func)(void *), void *arg, struct proc *p,
252 struct thread **newtdp, int flags, int pages, const char *fmt, ...)
255 struct thread *newtd, *oldtd;
258 panic("kthread_add called too soon");
260 /* If no process supplied, put it on proc0 */
264 /* Initialize our new td */
265 newtd = thread_alloc(pages);
270 oldtd = FIRST_THREAD_IN_PROC(p);
272 bzero(&newtd->td_startzero,
273 __rangeof(struct thread, td_startzero, td_endzero));
275 newtd->td_sleeptimo = 0;
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 newtd->td_proc = p; /* needed for cpu_set_upcall */
286 /* XXX optimise this probably? */
287 /* On x86 (and probably the others too) it is way too full of junk */
288 /* Needs a better name */
289 cpu_set_upcall(newtd, oldtd);
290 /* put the designated function(arg) as the resume context */
291 cpu_set_fork_handler(newtd, func, arg);
293 newtd->td_pflags |= TDP_KTHREAD;
294 newtd->td_ucred = crhold(p->p_ucred);
296 /* this code almost the same as create_thread() in kern_thr.c */
297 p->p_flag |= P_HADTHREADS;
298 thread_link(newtd, p);
300 /* let the scheduler know about these things. */
301 sched_fork_thread(oldtd, newtd);
302 TD_SET_CAN_RUN(newtd);
303 thread_unlock(oldtd);
308 /* Avoid inheriting affinity from a random parent. */
309 cpuset_setthread(newtd->td_tid, cpuset_root);
311 /* Delay putting it on the run queue until now. */
312 if (!(flags & RFSTOPPED)) {
314 sched_add(newtd, SRQ_BORING);
315 thread_unlock(newtd);
331 /* A module may be waiting for us to exit. */
335 * The last exiting thread in a kernel process must tear down
338 rw_wlock(&tidhash_lock);
340 if (p->p_numthreads == 1) {
342 rw_wunlock(&tidhash_lock);
345 LIST_REMOVE(td, td_hash);
346 rw_wunlock(&tidhash_lock);
347 umtx_thread_exit(td);
354 * Advise a kernel process to suspend (or resume) in its main loop.
355 * Participation is voluntary.
358 kthread_suspend(struct thread *td, int timo)
365 * td_pflags should not be read by any thread other than
366 * curthread, but as long as this flag is invariant during the
367 * thread's lifetime, it is OK to check its state.
369 if ((td->td_pflags & TDP_KTHREAD) == 0)
373 * The caller of the primitive should have already checked that the
374 * thread is up and running, thus not being blocked by other
379 td->td_flags |= TDF_KTH_SUSP;
381 return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt",
386 * Resume a thread previously put asleep with kthread_suspend().
389 kthread_resume(struct thread *td)
396 * td_pflags should not be read by any thread other than
397 * curthread, but as long as this flag is invariant during the
398 * thread's lifetime, it is OK to check its state.
400 if ((td->td_pflags & TDP_KTHREAD) == 0)
405 td->td_flags &= ~TDF_KTH_SUSP;
407 wakeup(&td->td_flags);
413 * Used by the thread to poll as to whether it should yield/sleep
414 * and notify the caller that is has happened.
417 kthread_suspend_check()
425 if ((td->td_pflags & TDP_KTHREAD) == 0)
426 panic("%s: curthread is not a valid kthread", __func__);
429 * As long as the double-lock protection is used when accessing the
430 * TDF_KTH_SUSP flag, synchronizing the read operation via proc mutex
434 while (td->td_flags & TDF_KTH_SUSP) {
435 wakeup(&td->td_flags);
436 msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0);
442 kproc_kthread_add(void (*func)(void *), void *arg,
443 struct proc **procptr, struct thread **tdptr,
444 int flags, int pages, const char *procname, const char *fmt, ...)
452 error = kproc_create(func, arg,
453 procptr, flags, pages, "%s", procname);
456 td = FIRST_THREAD_IN_PROC(*procptr);
460 vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
463 sched_clear_tdname(td);
468 vsnprintf(buf, sizeof(buf), fmt, ap);
470 error = kthread_add(func, arg, *procptr,
471 tdptr, flags, pages, "%s", buf);