kern_kthread.c revision 69657
148391Speter/* 248391Speter * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org> 348391Speter * All rights reserved. 448391Speter * 548391Speter * Redistribution and use in source and binary forms, with or without 648391Speter * modification, are permitted provided that the following conditions 748391Speter * are met: 848391Speter * 1. Redistributions of source code must retain the above copyright 948391Speter * notice, this list of conditions and the following disclaimer. 1048391Speter * 2. Redistributions in binary form must reproduce the above copyright 1148391Speter * notice, this list of conditions and the following disclaimer in the 1248391Speter * documentation and/or other materials provided with the distribution. 1348391Speter * 1448391Speter * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1548391Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1648391Speter * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1748391Speter * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1848391Speter * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1948391Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2048391Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2148391Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2248391Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2348391Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2448391Speter * SUCH DAMAGE. 2548391Speter * 2648391Speter * $FreeBSD: head/sys/kern/kern_kthread.c 69657 2000-12-06 03:45:15Z jhb $ 2748391Speter */ 2848391Speter 2948391Speter#include <sys/param.h> 3048391Speter#include <sys/systm.h> 3148391Speter#include <sys/proc.h> 3248391Speter#include <sys/kthread.h> 3355722Simp#include <sys/resourcevar.h> 3455539Sluoqi#include <sys/signalvar.h> 3548391Speter#include <sys/unistd.h> 3648391Speter#include <sys/wait.h> 3748391Speter 3848391Speter#include <machine/stdarg.h> 3948391Speter 4048391Speter/* 4148391Speter * Start a kernel process. This is called after a fork() call in 4248391Speter * mi_startup() in the file kern/init_main.c. 4348391Speter * 4448391Speter * This function is used to start "internal" daemons and intended 4548391Speter * to be called from SYSINIT(). 4648391Speter */ 4748391Spetervoid 4848391Speterkproc_start(udata) 4948391Speter const void *udata; 5048391Speter{ 5148391Speter const struct kproc_desc *kp = udata; 5248391Speter int error; 5348391Speter 5448391Speter error = kthread_create((void (*)(void *))kp->func, NULL, 5565557Sjasone kp->global_procpp, 0, kp->arg0); 5648391Speter if (error) 5748391Speter panic("kproc_start: %s: error %d", kp->arg0, error); 5848391Speter} 5948391Speter 6048391Speter/* 6165557Sjasone * Create a kernel process/thread/whatever. It shares its address space 6248391Speter * with proc0 - ie: kernel only. 6365557Sjasone * 6465557Sjasone * func is the function to start. 6565557Sjasone * arg is the parameter to pass to function on first startup. 6665557Sjasone * newpp is the return value pointing to the thread's struct proc. 6765557Sjasone * flags are flags to fork1 (in unistd.h) 6865557Sjasone * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.). 6948391Speter */ 7048391Speterint 7148391Speterkthread_create(void (*func)(void *), void *arg, 7265557Sjasone struct proc **newpp, int flags, const char *fmt, ...) 7348391Speter{ 7448391Speter int error; 7548391Speter va_list ap; 7648391Speter struct proc *p2; 7748391Speter 7865557Sjasone if (!proc0.p_stats /* || proc0.p_stats->p_start.tv_sec == 0 */) 7965557Sjasone panic("kthread_create called too soon"); 8065557Sjasone 8169657Sjhb error = fork1(&proc0, RFMEM | RFFDG | RFPROC | RFSTOPPED | flags, &p2); 8248391Speter if (error) 8348391Speter return error; 8448391Speter 8548391Speter /* save a global descriptor, if desired */ 8648391Speter if (newpp != NULL) 8748391Speter *newpp = p2; 8848391Speter 8948391Speter /* this is a non-swapped system process */ 9052140Sluoqi p2->p_flag |= P_INMEM | P_SYSTEM; 9152140Sluoqi p2->p_procsig->ps_flag |= PS_NOCLDWAIT; 9248391Speter PHOLD(p2); 9348391Speter 9448391Speter /* set up arg0 for 'ps', et al */ 9548391Speter va_start(ap, fmt); 9648391Speter vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap); 9748391Speter va_end(ap); 9848391Speter 9948391Speter /* call the processes' main()... */ 10048391Speter cpu_set_fork_handler(p2, func, arg); 10148391Speter 10269657Sjhb /* Delay putting it on the run queue until now. */ 10369657Sjhb if (!(flags & RFSTOPPED)) { 10469657Sjhb mtx_enter(&sched_lock, MTX_SPIN); 10569657Sjhb p2->p_stat = SRUN; 10669657Sjhb setrunqueue(p2); 10769657Sjhb mtx_exit(&sched_lock, MTX_SPIN); 10869657Sjhb } 10969657Sjhb 11048391Speter return 0; 11148391Speter} 11248391Speter 11348391Spetervoid 11448391Speterkthread_exit(int ecode) 11548391Speter{ 11667322Sjhb proc_reparent(curproc, initproc); 11748391Speter exit1(curproc, W_EXITCODE(ecode, 0)); 11848391Speter} 11948391Speter 12055539Sluoqi/* 12155539Sluoqi * Advise a kernel process to suspend (or resume) in its main loop. 12255539Sluoqi * Participation is voluntary. 12355539Sluoqi */ 12455539Sluoqiint 12555539Sluoqisuspend_kproc(struct proc *p, int timo) 12655539Sluoqi{ 12755539Sluoqi /* 12855539Sluoqi * Make sure this is indeed a system process and we can safely 12955539Sluoqi * use the p_siglist field. 13055539Sluoqi */ 13155539Sluoqi if ((p->p_flag & P_SYSTEM) == 0) 13255539Sluoqi return (EINVAL); 13355539Sluoqi SIGADDSET(p->p_siglist, SIGSTOP); 13455539Sluoqi return tsleep((caddr_t)&p->p_siglist, PPAUSE, "suspkp", timo); 13555539Sluoqi} 13655539Sluoqi 13755539Sluoqiint 13855539Sluoqiresume_kproc(struct proc *p) 13955539Sluoqi{ 14055539Sluoqi /* 14155539Sluoqi * Make sure this is indeed a system process and we can safely 14255539Sluoqi * use the p_siglist field. 14355539Sluoqi */ 14455539Sluoqi if ((p->p_flag & P_SYSTEM) == 0) 14555539Sluoqi return (EINVAL); 14655539Sluoqi SIGDELSET(p->p_siglist, SIGSTOP); 14755539Sluoqi wakeup((caddr_t)&p->p_siglist); 14855539Sluoqi return (0); 14955539Sluoqi} 15055539Sluoqi 15155539Sluoqivoid 15255539Sluoqikproc_suspend_loop(struct proc *p) 15355539Sluoqi{ 15455539Sluoqi while (SIGISMEMBER(p->p_siglist, SIGSTOP)) { 15555539Sluoqi wakeup((caddr_t)&p->p_siglist); 15655539Sluoqi tsleep((caddr_t)&p->p_siglist, PPAUSE, "kpsusp", 0); 15755539Sluoqi } 15855539Sluoqi} 159