xref: /freebsd/sys/kern/kern_thr.c (revision f2c49dd248bf7d1e03c7822ea6eb38e24a6b9f41)
1 /*
2  * Copyright (c) 2003, Jeffrey Roberson <jeff@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 unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  *
28  */
29 
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/proc.h>
35 #include <sys/resourcevar.h>
36 #include <sys/sched.h>
37 #include <sys/sysent.h>
38 #include <sys/systm.h>
39 #include <sys/sysproto.h>
40 #include <sys/signalvar.h>
41 #include <sys/ucontext.h>
42 #include <sys/thr.h>
43 
44 #include <machine/frame.h>
45 
46 /*
47  * Back end support functions.
48  */
49 
50 void
51 thr_exit1(void)
52 {
53 	struct ksegrp *kg;
54 	struct thread *td;
55 	struct kse *ke;
56 	struct proc *p;
57 
58 	td = curthread;
59 	p = td->td_proc;
60 	kg = td->td_ksegrp;
61 	ke = td->td_kse;
62 
63 	mtx_assert(&sched_lock, MA_OWNED);
64 	PROC_LOCK_ASSERT(p, MA_OWNED);
65 	KASSERT(!mtx_owned(&Giant), ("dying thread owns giant"));
66 
67 	/*
68 	 * Shutting down last thread in the proc.  This will actually
69 	 * call exit() in the trampoline when it returns.
70 	 */
71 	if (p->p_numthreads == 1) {
72 		PROC_UNLOCK(p);
73 		return;
74 	}
75 
76 	/*
77 	 * XXX Undelivered process wide signals should be reposted to the
78 	 * proc.
79 	 */
80 
81 	/* Clean up cpu resources. */
82 	cpu_thread_exit(td);
83 
84 	/* XXX make thread_unlink() */
85 	TAILQ_REMOVE(&p->p_threads, td, td_plist);
86 	p->p_numthreads--;
87 	TAILQ_REMOVE(&kg->kg_threads, td, td_kglist);
88 	kg->kg_numthreads--;
89 
90 	ke->ke_state = KES_UNQUEUED;
91 	ke->ke_thread = NULL;
92 	kse_unlink(ke);
93 	sched_exit_kse(TAILQ_NEXT(ke, ke_kglist), ke);
94 
95 	/*
96 	 * If we were stopped while waiting for all threads to exit and this
97 	 * is the last thread wakeup the exiting thread.
98 	 */
99 	if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE)
100 		if (p->p_numthreads == 1)
101 			thread_unsuspend_one(p->p_singlethread);
102 
103 	PROC_UNLOCK(p);
104 	td->td_kse = NULL;
105 	td->td_state = TDS_INACTIVE;
106 #if 0
107 	td->td_proc = NULL;
108 #endif
109 	td->td_ksegrp = NULL;
110 	td->td_last_kse = NULL;
111 	sched_exit_thread(TAILQ_NEXT(td, td_kglist), td);
112 	thread_stash(td);
113 
114 #if !defined(__alpha__) && !defined(__powerpc__)
115 	cpu_throw(td, choosethread());
116 #else
117 	cpu_throw();
118 #endif
119 }
120 
121 #define	RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
122 
123 /*
124  * System call interface.
125  */
126 int
127 thr_create(struct thread *td, struct thr_create_args *uap)
128     /* ucontext_t *ctx, thr_id_t *id, int flags */
129 {
130 	struct kse *ke0;
131 	struct thread *td0;
132 	ucontext_t ctx;
133 	int error;
134 
135 	if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
136 		return (error);
137 
138 	/* Initialize our td. */
139 	td0 = thread_alloc();
140 
141 	/*
142 	 * Try the copyout as soon as we allocate the td so we don't have to
143 	 * tear things down in a failure case below.
144 	 */
145 	if ((error = copyout(&td0, uap->id, sizeof(thr_id_t)))) {
146 		thread_free(td0);
147 		return (error);
148 	}
149 
150 	bzero(&td0->td_startzero,
151 	    (unsigned)RANGEOF(struct thread, td_startzero, td_endzero));
152 	bcopy(&td->td_startcopy, &td0->td_startcopy,
153 	    (unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy));
154 
155 	td0->td_proc = td->td_proc;
156 	PROC_LOCK(td->td_proc);
157 	td0->td_sigmask = td->td_sigmask;
158 	PROC_UNLOCK(td->td_proc);
159 	bcopy(td->td_frame, td0->td_frame, sizeof(struct trapframe));
160 	td0->td_ucred = crhold(td->td_ucred);
161 
162 	/* Initialize our kse structure. */
163 	ke0 = kse_alloc();
164 	bzero(&ke0->ke_startzero,
165 	    RANGEOF(struct kse, ke_startzero, ke_endzero));
166 
167 	/* Set up our machine context. */
168 	cpu_set_upcall(td0, td->td_pcb);
169 	error = set_mcontext(td0, &ctx.uc_mcontext);
170 	if (error != 0) {
171 		kse_free(ke0);
172 		thread_free(td0);
173 		goto out;
174 	}
175 
176 	/* Link the thread and kse into the ksegrp and make it runnable. */
177 	mtx_lock_spin(&sched_lock);
178 
179 	thread_link(td0, td->td_ksegrp);
180 	kse_link(ke0, td->td_ksegrp);
181 
182 	/* Bind this thread and kse together. */
183 	td0->td_kse = ke0;
184 	ke0->ke_thread = td0;
185 
186 	sched_fork_kse(td->td_kse, ke0);
187 	sched_fork_thread(td, td0);
188 
189 	TD_SET_CAN_RUN(td0);
190 	if ((uap->flags & THR_SUSPENDED) == 0)
191 		setrunqueue(td0);
192 
193 	mtx_unlock_spin(&sched_lock);
194 
195 out:
196 	return (error);
197 }
198 
199 int
200 thr_self(struct thread *td, struct thr_self_args *uap)
201     /* thr_id_t *id */
202 {
203 	int error;
204 
205 	if ((error = copyout(&td, uap->id, sizeof(thr_id_t))))
206 		return (error);
207 
208 	return (0);
209 }
210 
211 int
212 thr_exit(struct thread *td, struct thr_exit_args *uap)
213     /* NULL */
214 {
215 	struct proc *p;
216 
217 	p = td->td_proc;
218 
219 	PROC_LOCK(p);
220 	mtx_lock_spin(&sched_lock);
221 
222 	/*
223 	 * This unlocks proc and doesn't return unless this is the last
224 	 * thread.
225 	 */
226 	thr_exit1();
227 	mtx_unlock_spin(&sched_lock);
228 
229 	return (0);
230 }
231 
232 int
233 thr_kill(struct thread *td, struct thr_kill_args *uap)
234     /* thr_id_t id, int sig */
235 {
236 	struct thread *ttd;
237 	struct proc *p;
238 	int error;
239 
240 	p = td->td_proc;
241 	error = 0;
242 
243 	PROC_LOCK(p);
244 
245 	FOREACH_THREAD_IN_PROC(p, ttd)
246 		if (ttd == uap->id)
247 			break;
248 
249 	if (ttd == NULL) {
250 		error = ESRCH;
251 		goto out;
252 	}
253 
254 	if (uap->sig == 0)
255 		goto out;
256 
257 	if (!_SIG_VALID(uap->sig)) {
258 		error = EINVAL;
259 		goto out;
260 	}
261 
262 	/*
263 	 * We need a way to force this to go into this thread's siglist.
264 	 * Until then blocked signals will go to the proc.
265 	 */
266 	tdsignal(ttd, uap->sig);
267 out:
268 	PROC_UNLOCK(p);
269 
270 	return (error);
271 }
272