xref: /freebsd/sys/kern/kern_thr.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
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 	cpu_throw(td, choosethread());
115 }
116 
117 #define	RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
118 
119 /*
120  * System call interface.
121  */
122 int
123 thr_create(struct thread *td, struct thr_create_args *uap)
124     /* ucontext_t *ctx, thr_id_t *id, int flags */
125 {
126 	struct kse *ke0;
127 	struct thread *td0;
128 	ucontext_t ctx;
129 	int error;
130 
131 	if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
132 		return (error);
133 
134 	/* Initialize our td. */
135 	td0 = thread_alloc();
136 
137 	/*
138 	 * Try the copyout as soon as we allocate the td so we don't have to
139 	 * tear things down in a failure case below.
140 	 */
141 	if ((error = copyout(&td0, uap->id, sizeof(thr_id_t)))) {
142 		thread_free(td0);
143 		return (error);
144 	}
145 
146 	bzero(&td0->td_startzero,
147 	    (unsigned)RANGEOF(struct thread, td_startzero, td_endzero));
148 	bcopy(&td->td_startcopy, &td0->td_startcopy,
149 	    (unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy));
150 
151 	td0->td_proc = td->td_proc;
152 	PROC_LOCK(td->td_proc);
153 	td0->td_sigmask = td->td_sigmask;
154 	PROC_UNLOCK(td->td_proc);
155 	td0->td_ucred = crhold(td->td_ucred);
156 
157 	/* Initialize our kse structure. */
158 	ke0 = kse_alloc();
159 	bzero(&ke0->ke_startzero,
160 	    RANGEOF(struct kse, ke_startzero, ke_endzero));
161 
162 	/* Set up our machine context. */
163 	cpu_set_upcall(td0, td);
164 	error = set_mcontext(td0, &ctx.uc_mcontext);
165 	if (error != 0) {
166 		kse_free(ke0);
167 		thread_free(td0);
168 		goto out;
169 	}
170 
171 	/* Link the thread and kse into the ksegrp and make it runnable. */
172 	mtx_lock_spin(&sched_lock);
173 
174 	thread_link(td0, td->td_ksegrp);
175 	kse_link(ke0, td->td_ksegrp);
176 
177 	/* Bind this thread and kse together. */
178 	td0->td_kse = ke0;
179 	ke0->ke_thread = td0;
180 
181 	sched_fork_kse(td->td_kse, ke0);
182 	sched_fork_thread(td, td0);
183 
184 	TD_SET_CAN_RUN(td0);
185 	if ((uap->flags & THR_SUSPENDED) == 0)
186 		setrunqueue(td0);
187 
188 	mtx_unlock_spin(&sched_lock);
189 
190 out:
191 	return (error);
192 }
193 
194 int
195 thr_self(struct thread *td, struct thr_self_args *uap)
196     /* thr_id_t *id */
197 {
198 	int error;
199 
200 	if ((error = copyout(&td, uap->id, sizeof(thr_id_t))))
201 		return (error);
202 
203 	return (0);
204 }
205 
206 int
207 thr_exit(struct thread *td, struct thr_exit_args *uap)
208     /* NULL */
209 {
210 	struct proc *p;
211 
212 	p = td->td_proc;
213 
214 	PROC_LOCK(p);
215 	mtx_lock_spin(&sched_lock);
216 
217 	/*
218 	 * This unlocks proc and doesn't return unless this is the last
219 	 * thread.
220 	 */
221 	thr_exit1();
222 	mtx_unlock_spin(&sched_lock);
223 
224 	return (0);
225 }
226 
227 int
228 thr_kill(struct thread *td, struct thr_kill_args *uap)
229     /* thr_id_t id, int sig */
230 {
231 	struct thread *ttd;
232 	struct proc *p;
233 	int error;
234 
235 	p = td->td_proc;
236 	error = 0;
237 	PROC_LOCK(p);
238 	FOREACH_THREAD_IN_PROC(p, ttd) {
239 		if (ttd == uap->id)
240 			break;
241 	}
242 	if (ttd == NULL) {
243 		error = ESRCH;
244 		goto out;
245 	}
246 	if (uap->sig == 0)
247 		goto out;
248 	if (!_SIG_VALID(uap->sig)) {
249 		error = EINVAL;
250 		goto out;
251 	}
252 	tdsignal(ttd, uap->sig, SIGTARGET_TD);
253 out:
254 	PROC_UNLOCK(p);
255 	return (error);
256 }
257