| 1 | /* |
| 2 | * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org> |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 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. |
| 13 | * |
| 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 |
| 24 | * SUCH DAMAGE. |
| 25 | * |
| 26 | * $FreeBSD: src/sys/kern/kern_kthread.c,v 1.5.2.3 2001/12/25 01:51:14 dillon Exp $ |
| 27 | * $DragonFly: src/sys/kern/kern_kthread.c,v 1.13 2006/12/18 20:41:01 dillon Exp $ |
| 28 | */ |
| 29 | |
| 30 | #include <sys/param.h> |
| 31 | #include <sys/systm.h> |
| 32 | #include <sys/proc.h> |
| 33 | #include <sys/kthread.h> |
| 34 | #include <sys/ptrace.h> |
| 35 | #include <sys/resourcevar.h> |
| 36 | #include <sys/signalvar.h> |
| 37 | #include <sys/unistd.h> |
| 38 | #include <sys/wait.h> |
| 39 | |
| 40 | #include <machine/stdarg.h> |
| 41 | |
| 42 | static struct lwkt_token kpsus_token = LWKT_TOKEN_INITIALIZER(kpsus_token); |
| 43 | |
| 44 | |
| 45 | /* |
| 46 | * Create a kernel process/thread/whatever. It shares it's address space |
| 47 | * with proc0 - ie: kernel only. 5.x compatible. |
| 48 | * |
| 49 | * All kthreads are created as MPSAFE threads. |
| 50 | */ |
| 51 | int |
| 52 | kthread_create(void (*func)(void *), void *arg, |
| 53 | struct thread **tdp, const char *fmt, ...) |
| 54 | { |
| 55 | thread_t td; |
| 56 | __va_list ap; |
| 57 | |
| 58 | td = lwkt_alloc_thread(NULL, LWKT_THREAD_STACK, -1, TDF_VERBOSE); |
| 59 | if (tdp) |
| 60 | *tdp = td; |
| 61 | cpu_set_thread_handler(td, kthread_exit, func, arg); |
| 62 | |
| 63 | /* |
| 64 | * Set up arg0 for 'ps' etc |
| 65 | */ |
| 66 | __va_start(ap, fmt); |
| 67 | kvsnprintf(td->td_comm, sizeof(td->td_comm), fmt, ap); |
| 68 | __va_end(ap); |
| 69 | |
| 70 | td->td_ucred = crhold(proc0.p_ucred); |
| 71 | |
| 72 | /* |
| 73 | * Schedule the thread to run |
| 74 | */ |
| 75 | lwkt_schedule(td); |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | int |
| 80 | kthread_create_cpu(void (*func)(void *), void *arg, |
| 81 | struct thread **tdp, int cpu, const char *fmt, ...) |
| 82 | { |
| 83 | thread_t td; |
| 84 | __va_list ap; |
| 85 | |
| 86 | td = lwkt_alloc_thread(NULL, LWKT_THREAD_STACK, cpu, TDF_VERBOSE); |
| 87 | if (tdp) |
| 88 | *tdp = td; |
| 89 | cpu_set_thread_handler(td, kthread_exit, func, arg); |
| 90 | |
| 91 | /* |
| 92 | * Set up arg0 for 'ps' etc |
| 93 | */ |
| 94 | __va_start(ap, fmt); |
| 95 | kvsnprintf(td->td_comm, sizeof(td->td_comm), fmt, ap); |
| 96 | __va_end(ap); |
| 97 | |
| 98 | td->td_ucred = crhold(proc0.p_ucred); |
| 99 | |
| 100 | /* |
| 101 | * Schedule the thread to run |
| 102 | */ |
| 103 | lwkt_schedule(td); |
| 104 | return 0; |
| 105 | } |
| 106 | |
| 107 | #if 0 |
| 108 | /* |
| 109 | * Same as kthread_create() but you can specify a custom stack size. |
| 110 | */ |
| 111 | int |
| 112 | kthread_create_stk(void (*func)(void *), void *arg, |
| 113 | struct thread **tdp, int stksize, const char *fmt, ...) |
| 114 | { |
| 115 | thread_t td; |
| 116 | __va_list ap; |
| 117 | |
| 118 | td = lwkt_alloc_thread(NULL, stksize, -1, TDF_VERBOSE); |
| 119 | if (tdp) |
| 120 | *tdp = td; |
| 121 | cpu_set_thread_handler(td, kthread_exit, func, arg); |
| 122 | |
| 123 | __va_start(ap, fmt); |
| 124 | kvsnprintf(td->td_comm, sizeof(td->td_comm), fmt, ap); |
| 125 | __va_end(ap); |
| 126 | |
| 127 | lwkt_schedule(td); |
| 128 | return 0; |
| 129 | } |
| 130 | #endif |
| 131 | |
| 132 | /* |
| 133 | * Destroy an LWKT thread. Warning! This function is not called when |
| 134 | * a process exits, cpu_proc_exit() directly calls cpu_thread_exit() and |
| 135 | * uses a different reaping mechanism. |
| 136 | * |
| 137 | * XXX duplicates lwkt_exit() |
| 138 | */ |
| 139 | void |
| 140 | kthread_exit(void) |
| 141 | { |
| 142 | lwkt_exit(); |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Start a kernel process. This is called after a fork() call in |
| 147 | * mi_startup() in the file kern/init_main.c. |
| 148 | * |
| 149 | * This function is used to start "internal" daemons and intended |
| 150 | * to be called from SYSINIT(). |
| 151 | * |
| 152 | * These threads are created MPSAFE. |
| 153 | */ |
| 154 | void |
| 155 | kproc_start(const void *udata) |
| 156 | { |
| 157 | const struct kproc_desc *kp = udata; |
| 158 | int error; |
| 159 | |
| 160 | error = kthread_create((void (*)(void *))kp->func, NULL, |
| 161 | kp->global_threadpp, kp->arg0); |
| 162 | lwkt_setpri(*kp->global_threadpp, TDPRI_KERN_DAEMON); |
| 163 | if (error) |
| 164 | panic("kproc_start: %s: error %d", kp->arg0, error); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * Advise a kernel process to suspend (or resume) in its main loop. |
| 169 | * Participation is voluntary. |
| 170 | */ |
| 171 | int |
| 172 | suspend_kproc(struct thread *td, int timo) |
| 173 | { |
| 174 | if (td->td_proc == NULL) { |
| 175 | lwkt_gettoken(&kpsus_token); |
| 176 | /* request thread pause */ |
| 177 | atomic_set_int(&td->td_mpflags, TDF_MP_STOPREQ); |
| 178 | wakeup(td); |
| 179 | while (td->td_mpflags & TDF_MP_STOPREQ) { |
| 180 | int error = tsleep(td, 0, "suspkp", timo); |
| 181 | if (error == EWOULDBLOCK) |
| 182 | break; |
| 183 | } |
| 184 | atomic_clear_int(&td->td_mpflags, TDF_MP_STOPREQ); |
| 185 | lwkt_reltoken(&kpsus_token); |
| 186 | return(0); |
| 187 | } else { |
| 188 | return(EINVAL); /* not a kernel thread */ |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | void |
| 193 | kproc_suspend_loop(void) |
| 194 | { |
| 195 | struct thread *td = curthread; |
| 196 | |
| 197 | if (td->td_mpflags & TDF_MP_STOPREQ) { |
| 198 | lwkt_gettoken(&kpsus_token); |
| 199 | atomic_clear_int(&td->td_mpflags, TDF_MP_STOPREQ); |
| 200 | while ((td->td_mpflags & TDF_MP_WAKEREQ) == 0) { |
| 201 | wakeup(td); |
| 202 | tsleep(td, 0, "kpsusp", 0); |
| 203 | } |
| 204 | atomic_clear_int(&td->td_mpflags, TDF_MP_WAKEREQ); |
| 205 | wakeup(td); |
| 206 | lwkt_reltoken(&kpsus_token); |
| 207 | } |
| 208 | } |
| 209 | |