1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate #include <sys/param.h>
32*0Sstevel@tonic-gate #include <sys/types.h>
33*0Sstevel@tonic-gate #include <sys/sysmacros.h>
34*0Sstevel@tonic-gate #include <sys/systm.h>
35*0Sstevel@tonic-gate #include <sys/errno.h>
36*0Sstevel@tonic-gate #include <sys/syscall.h>
37*0Sstevel@tonic-gate #include <sys/proc.h>
38*0Sstevel@tonic-gate #include <sys/processor.h>
39*0Sstevel@tonic-gate #include <sys/fault.h>
40*0Sstevel@tonic-gate #include <sys/ucontext.h>
41*0Sstevel@tonic-gate #include <sys/signal.h>
42*0Sstevel@tonic-gate #include <sys/unistd.h>
43*0Sstevel@tonic-gate #include <sys/procfs.h>
44*0Sstevel@tonic-gate #include <sys/prsystm.h>
45*0Sstevel@tonic-gate #include <sys/cmn_err.h>
46*0Sstevel@tonic-gate #include <sys/debug.h>
47*0Sstevel@tonic-gate #include <sys/klwp.h>
48*0Sstevel@tonic-gate #include <sys/pool.h>
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate /*
51*0Sstevel@tonic-gate  * System call to create an lwp.
52*0Sstevel@tonic-gate  *
53*0Sstevel@tonic-gate  * Notes on the LWP_DETACHED and LWP_DAEMON flags:
54*0Sstevel@tonic-gate  *
55*0Sstevel@tonic-gate  * A detached lwp (LWP_DETACHED) cannot be the specific target of
56*0Sstevel@tonic-gate  * lwp_wait() (it is not joinable), but lwp_wait(0, ...) is required
57*0Sstevel@tonic-gate  * to sleep until all non-daemon detached lwps have terminated before
58*0Sstevel@tonic-gate  * returning EDEADLK because a detached lwp might create a non-detached lwp
59*0Sstevel@tonic-gate  * that could then be returned by lwp_wait(0, ...).  See also lwp_detach().
60*0Sstevel@tonic-gate  *
61*0Sstevel@tonic-gate  * A daemon lwp (LWP_DAEMON) is a detached lwp that has the additional
62*0Sstevel@tonic-gate  * property that it does not affect the termination condition of the
63*0Sstevel@tonic-gate  * process:  The last non-daemon lwp to call lwp_exit() causes the process
64*0Sstevel@tonic-gate  * to exit and lwp_wait(0, ...) does not sleep waiting for daemon lwps
65*0Sstevel@tonic-gate  * to terminate.  See the block comment before lwp_wait().
66*0Sstevel@tonic-gate  */
67*0Sstevel@tonic-gate int
68*0Sstevel@tonic-gate syslwp_create(ucontext_t *ucp, int flags, id_t *new_lwp)
69*0Sstevel@tonic-gate {
70*0Sstevel@tonic-gate 	klwp_t *lwp;
71*0Sstevel@tonic-gate 	proc_t *p = ttoproc(curthread);
72*0Sstevel@tonic-gate 	kthread_t *t;
73*0Sstevel@tonic-gate 	ucontext_t uc;
74*0Sstevel@tonic-gate #ifdef _SYSCALL32_IMPL
75*0Sstevel@tonic-gate 	ucontext32_t uc32;
76*0Sstevel@tonic-gate #endif /* _SYSCALL32_IMPL */
77*0Sstevel@tonic-gate 	k_sigset_t sigmask;
78*0Sstevel@tonic-gate 	int	tid;
79*0Sstevel@tonic-gate 	model_t model = get_udatamodel();
80*0Sstevel@tonic-gate 	uintptr_t thrptr = 0;
81*0Sstevel@tonic-gate 
82*0Sstevel@tonic-gate 	if (flags & ~(LWP_DAEMON|LWP_DETACHED|LWP_SUSPENDED))
83*0Sstevel@tonic-gate 		return (set_errno(EINVAL));
84*0Sstevel@tonic-gate 
85*0Sstevel@tonic-gate 	/*
86*0Sstevel@tonic-gate 	 * lwp_create() is disallowed for the /proc agent lwp.
87*0Sstevel@tonic-gate 	 */
88*0Sstevel@tonic-gate 	if (curthread == p->p_agenttp)
89*0Sstevel@tonic-gate 		return (set_errno(ENOTSUP));
90*0Sstevel@tonic-gate 
91*0Sstevel@tonic-gate 	if (model == DATAMODEL_NATIVE) {
92*0Sstevel@tonic-gate 		if (copyin(ucp, &uc, sizeof (ucontext_t)))
93*0Sstevel@tonic-gate 			return (set_errno(EFAULT));
94*0Sstevel@tonic-gate 		sigutok(&uc.uc_sigmask, &sigmask);
95*0Sstevel@tonic-gate #if defined(__i386)
96*0Sstevel@tonic-gate 		/*
97*0Sstevel@tonic-gate 		 * libc stashed thrptr into unused kernel %sp.
98*0Sstevel@tonic-gate 		 * See setup_context() in libc.
99*0Sstevel@tonic-gate 		 */
100*0Sstevel@tonic-gate 		thrptr = (uint32_t)uc.uc_mcontext.gregs[ESP];
101*0Sstevel@tonic-gate #endif
102*0Sstevel@tonic-gate 	}
103*0Sstevel@tonic-gate #ifdef _SYSCALL32_IMPL
104*0Sstevel@tonic-gate 	else {
105*0Sstevel@tonic-gate 		if (copyin(ucp, &uc32, sizeof (ucontext32_t)))
106*0Sstevel@tonic-gate 			return (set_errno(EFAULT));
107*0Sstevel@tonic-gate 		sigutok(&uc32.uc_sigmask, &sigmask);
108*0Sstevel@tonic-gate #if defined(__sparc)
109*0Sstevel@tonic-gate 		ucontext_32ton(&uc32, &uc, NULL, NULL);
110*0Sstevel@tonic-gate #else	/* __amd64 */
111*0Sstevel@tonic-gate 		ucontext_32ton(&uc32, &uc);
112*0Sstevel@tonic-gate 		/*
113*0Sstevel@tonic-gate 		 * libc stashed thrptr into unused kernel %sp.
114*0Sstevel@tonic-gate 		 * See setup_context() in libc.
115*0Sstevel@tonic-gate 		 */
116*0Sstevel@tonic-gate 		thrptr = (uint32_t)uc32.uc_mcontext.gregs[ESP];
117*0Sstevel@tonic-gate #endif
118*0Sstevel@tonic-gate 	}
119*0Sstevel@tonic-gate #endif /* _SYSCALL32_IMPL */
120*0Sstevel@tonic-gate 
121*0Sstevel@tonic-gate 	(void) save_syscall_args();	/* save args for tracing first */
122*0Sstevel@tonic-gate 
123*0Sstevel@tonic-gate 	mutex_enter(&curproc->p_lock);
124*0Sstevel@tonic-gate 	pool_barrier_enter();
125*0Sstevel@tonic-gate 	mutex_exit(&curproc->p_lock);
126*0Sstevel@tonic-gate 	lwp = lwp_create(lwp_rtt, NULL, NULL, curproc, TS_STOPPED,
127*0Sstevel@tonic-gate 		curthread->t_pri, &sigmask, curthread->t_cid, 0);
128*0Sstevel@tonic-gate 	mutex_enter(&curproc->p_lock);
129*0Sstevel@tonic-gate 	pool_barrier_exit();
130*0Sstevel@tonic-gate 	mutex_exit(&curproc->p_lock);
131*0Sstevel@tonic-gate 	if (lwp == NULL)
132*0Sstevel@tonic-gate 		return (set_errno(EAGAIN));
133*0Sstevel@tonic-gate 
134*0Sstevel@tonic-gate 	lwp_load(lwp, uc.uc_mcontext.gregs, thrptr);
135*0Sstevel@tonic-gate 
136*0Sstevel@tonic-gate 	t = lwptot(lwp);
137*0Sstevel@tonic-gate 	/*
138*0Sstevel@tonic-gate 	 * Copy the new lwp's lwpid into the caller's specified buffer.
139*0Sstevel@tonic-gate 	 */
140*0Sstevel@tonic-gate 	if (new_lwp && copyout(&t->t_tid, new_lwp, sizeof (id_t))) {
141*0Sstevel@tonic-gate 		/*
142*0Sstevel@tonic-gate 		 * caller's buffer is not writable, return
143*0Sstevel@tonic-gate 		 * EFAULT, and terminate new lwp.
144*0Sstevel@tonic-gate 		 */
145*0Sstevel@tonic-gate 		mutex_enter(&p->p_lock);
146*0Sstevel@tonic-gate 		t->t_proc_flag |= TP_EXITLWP;
147*0Sstevel@tonic-gate 		t->t_sig_check = 1;
148*0Sstevel@tonic-gate 		t->t_sysnum = 0;
149*0Sstevel@tonic-gate 		t->t_proc_flag &= ~TP_HOLDLWP;
150*0Sstevel@tonic-gate 		lwp_create_done(t);
151*0Sstevel@tonic-gate 		mutex_exit(&p->p_lock);
152*0Sstevel@tonic-gate 		return (set_errno(EFAULT));
153*0Sstevel@tonic-gate 	}
154*0Sstevel@tonic-gate 
155*0Sstevel@tonic-gate 	/*
156*0Sstevel@tonic-gate 	 * clone callers context, if any.  must be invoked
157*0Sstevel@tonic-gate 	 * while -not- holding p_lock.
158*0Sstevel@tonic-gate 	 */
159*0Sstevel@tonic-gate 	if (curthread->t_ctx)
160*0Sstevel@tonic-gate 		lwp_createctx(curthread, t);
161*0Sstevel@tonic-gate 
162*0Sstevel@tonic-gate 	/*
163*0Sstevel@tonic-gate 	 * copy current contract templates
164*0Sstevel@tonic-gate 	 */
165*0Sstevel@tonic-gate 	lwp_ctmpl_copy(lwp, ttolwp(curthread));
166*0Sstevel@tonic-gate 
167*0Sstevel@tonic-gate 	mutex_enter(&p->p_lock);
168*0Sstevel@tonic-gate 	/*
169*0Sstevel@tonic-gate 	 * Copy the syscall arguments to the new lwp's arg area
170*0Sstevel@tonic-gate 	 * for the benefit of debuggers.
171*0Sstevel@tonic-gate 	 */
172*0Sstevel@tonic-gate 	t->t_sysnum = SYS_lwp_create;
173*0Sstevel@tonic-gate 	lwp->lwp_ap = lwp->lwp_arg;
174*0Sstevel@tonic-gate 	lwp->lwp_arg[0] = (long)ucp;
175*0Sstevel@tonic-gate 	lwp->lwp_arg[1] = (long)flags;
176*0Sstevel@tonic-gate 	lwp->lwp_arg[2] = (long)new_lwp;
177*0Sstevel@tonic-gate 	lwp->lwp_argsaved = 1;
178*0Sstevel@tonic-gate 
179*0Sstevel@tonic-gate 	if (!(flags & (LWP_DETACHED|LWP_DAEMON)))
180*0Sstevel@tonic-gate 		t->t_proc_flag |= TP_TWAIT;
181*0Sstevel@tonic-gate 	if (flags & LWP_DAEMON) {
182*0Sstevel@tonic-gate 		t->t_proc_flag |= TP_DAEMON;
183*0Sstevel@tonic-gate 		p->p_lwpdaemon++;
184*0Sstevel@tonic-gate 	}
185*0Sstevel@tonic-gate 
186*0Sstevel@tonic-gate 	tid = (int)t->t_tid;	/* for /proc debuggers */
187*0Sstevel@tonic-gate 
188*0Sstevel@tonic-gate 	/*
189*0Sstevel@tonic-gate 	 * We now set the newly-created lwp running.
190*0Sstevel@tonic-gate 	 * If it is being created as LWP_SUSPENDED, we leave its
191*0Sstevel@tonic-gate 	 * TP_HOLDLWP flag set so it will stop in system call exit.
192*0Sstevel@tonic-gate 	 */
193*0Sstevel@tonic-gate 	if (!(flags & LWP_SUSPENDED))
194*0Sstevel@tonic-gate 		t->t_proc_flag &= ~TP_HOLDLWP;
195*0Sstevel@tonic-gate 	lwp_create_done(t);
196*0Sstevel@tonic-gate 	mutex_exit(&p->p_lock);
197*0Sstevel@tonic-gate 
198*0Sstevel@tonic-gate 	return (tid);
199*0Sstevel@tonic-gate }
200*0Sstevel@tonic-gate 
201*0Sstevel@tonic-gate /*
202*0Sstevel@tonic-gate  * Exit the calling lwp
203*0Sstevel@tonic-gate  */
204*0Sstevel@tonic-gate void
205*0Sstevel@tonic-gate syslwp_exit()
206*0Sstevel@tonic-gate {
207*0Sstevel@tonic-gate 	proc_t *p = ttoproc(curthread);
208*0Sstevel@tonic-gate 
209*0Sstevel@tonic-gate 	mutex_enter(&p->p_lock);
210*0Sstevel@tonic-gate 	lwp_exit();
211*0Sstevel@tonic-gate 	/* NOTREACHED */
212*0Sstevel@tonic-gate }
213