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kern_lwp.c revision 1.49.2.1
      1  1.49.2.1    bouyer /*	$NetBSD: kern_lwp.c,v 1.49.2.1 2007/04/01 16:16:20 bouyer Exp $	*/
      2       1.2   thorpej 
      3       1.2   thorpej /*-
      4       1.2   thorpej  * Copyright (c) 2001 The NetBSD Foundation, Inc.
      5       1.2   thorpej  * All rights reserved.
      6       1.2   thorpej  *
      7       1.2   thorpej  * This code is derived from software contributed to The NetBSD Foundation
      8       1.2   thorpej  * by Nathan J. Williams.
      9       1.2   thorpej  *
     10       1.2   thorpej  * Redistribution and use in source and binary forms, with or without
     11       1.2   thorpej  * modification, are permitted provided that the following conditions
     12       1.2   thorpej  * are met:
     13       1.2   thorpej  * 1. Redistributions of source code must retain the above copyright
     14       1.2   thorpej  *    notice, this list of conditions and the following disclaimer.
     15       1.2   thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     16       1.2   thorpej  *    notice, this list of conditions and the following disclaimer in the
     17       1.2   thorpej  *    documentation and/or other materials provided with the distribution.
     18       1.2   thorpej  * 3. All advertising materials mentioning features or use of this software
     19       1.2   thorpej  *    must display the following acknowledgement:
     20       1.2   thorpej  *        This product includes software developed by the NetBSD
     21       1.2   thorpej  *        Foundation, Inc. and its contributors.
     22       1.2   thorpej  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23       1.2   thorpej  *    contributors may be used to endorse or promote products derived
     24       1.2   thorpej  *    from this software without specific prior written permission.
     25       1.2   thorpej  *
     26       1.2   thorpej  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27       1.2   thorpej  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28       1.2   thorpej  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29       1.2   thorpej  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30       1.2   thorpej  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31       1.2   thorpej  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32       1.2   thorpej  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33       1.2   thorpej  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34       1.2   thorpej  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35       1.2   thorpej  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36       1.2   thorpej  * POSSIBILITY OF SUCH DAMAGE.
     37       1.2   thorpej  */
     38       1.9     lukem 
     39       1.9     lukem #include <sys/cdefs.h>
     40  1.49.2.1    bouyer __KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.49.2.1 2007/04/01 16:16:20 bouyer Exp $");
     41       1.8    martin 
     42       1.8    martin #include "opt_multiprocessor.h"
     43       1.2   thorpej 
     44      1.47   hannken #define _LWP_API_PRIVATE
     45      1.47   hannken 
     46       1.2   thorpej #include <sys/param.h>
     47       1.2   thorpej #include <sys/systm.h>
     48       1.2   thorpej #include <sys/pool.h>
     49       1.2   thorpej #include <sys/lock.h>
     50       1.2   thorpej #include <sys/proc.h>
     51       1.2   thorpej #include <sys/sa.h>
     52       1.2   thorpej #include <sys/savar.h>
     53       1.2   thorpej #include <sys/types.h>
     54       1.2   thorpej #include <sys/ucontext.h>
     55       1.2   thorpej #include <sys/resourcevar.h>
     56       1.2   thorpej #include <sys/mount.h>
     57       1.2   thorpej #include <sys/syscallargs.h>
     58      1.37        ad #include <sys/kauth.h>
     59       1.2   thorpej 
     60       1.2   thorpej #include <uvm/uvm_extern.h>
     61       1.2   thorpej 
     62      1.41   thorpej POOL_INIT(lwp_pool, sizeof(struct lwp), 0, 0, 0, "lwppl",
     63      1.41   thorpej     &pool_allocator_nointr);
     64      1.41   thorpej POOL_INIT(lwp_uc_pool, sizeof(ucontext_t), 0, 0, 0, "lwpucpl",
     65      1.41   thorpej     &pool_allocator_nointr);
     66      1.41   thorpej 
     67      1.41   thorpej static specificdata_domain_t lwp_specificdata_domain;
     68      1.41   thorpej 
     69       1.2   thorpej struct lwplist alllwp;
     70       1.2   thorpej 
     71       1.2   thorpej #define LWP_DEBUG
     72       1.2   thorpej 
     73       1.2   thorpej #ifdef LWP_DEBUG
     74       1.2   thorpej int lwp_debug = 0;
     75       1.2   thorpej #define DPRINTF(x) if (lwp_debug) printf x
     76       1.2   thorpej #else
     77       1.2   thorpej #define DPRINTF(x)
     78       1.2   thorpej #endif
     79      1.41   thorpej 
     80      1.41   thorpej void
     81      1.41   thorpej lwpinit(void)
     82      1.41   thorpej {
     83      1.41   thorpej 
     84      1.41   thorpej 	lwp_specificdata_domain = specificdata_domain_create();
     85      1.41   thorpej 	KASSERT(lwp_specificdata_domain != NULL);
     86      1.41   thorpej }
     87      1.41   thorpej 
     88       1.2   thorpej /* ARGSUSED */
     89       1.2   thorpej int
     90      1.48      yamt sys__lwp_create(struct lwp *l, void *v, register_t *retval)
     91       1.2   thorpej {
     92       1.2   thorpej 	struct sys__lwp_create_args /* {
     93       1.2   thorpej 		syscallarg(const ucontext_t *) ucp;
     94       1.2   thorpej 		syscallarg(u_long) flags;
     95       1.2   thorpej 		syscallarg(lwpid_t *) new_lwp;
     96       1.2   thorpej 	} */ *uap = v;
     97       1.2   thorpej 	struct proc *p = l->l_proc;
     98       1.2   thorpej 	struct lwp *l2;
     99       1.2   thorpej 	vaddr_t uaddr;
    100       1.2   thorpej 	boolean_t inmem;
    101       1.2   thorpej 	ucontext_t *newuc;
    102       1.2   thorpej 	int s, error;
    103       1.2   thorpej 
    104      1.33       chs 	if (p->p_flag & P_SA)
    105      1.33       chs 		return EINVAL;
    106      1.33       chs 
    107       1.2   thorpej 	newuc = pool_get(&lwp_uc_pool, PR_WAITOK);
    108       1.2   thorpej 
    109      1.34      cube 	error = copyin(SCARG(uap, ucp), newuc,
    110      1.34      cube 	    l->l_proc->p_emul->e_sa->sae_ucsize);
    111      1.40        ad 	if (error) {
    112      1.40        ad 		pool_put(&lwp_uc_pool, newuc);
    113       1.2   thorpej 		return (error);
    114      1.40        ad 	}
    115       1.2   thorpej 
    116       1.2   thorpej 	/* XXX check against resource limits */
    117       1.2   thorpej 
    118       1.2   thorpej 	inmem = uvm_uarea_alloc(&uaddr);
    119       1.2   thorpej 	if (__predict_false(uaddr == 0)) {
    120      1.40        ad 		pool_put(&lwp_uc_pool, newuc);
    121       1.2   thorpej 		return (ENOMEM);
    122       1.2   thorpej 	}
    123       1.2   thorpej 
    124       1.2   thorpej 	/* XXX flags:
    125       1.2   thorpej 	 * __LWP_ASLWP is probably needed for Solaris compat.
    126       1.2   thorpej 	 */
    127       1.2   thorpej 
    128       1.2   thorpej 	newlwp(l, p, uaddr, inmem,
    129       1.2   thorpej 	    SCARG(uap, flags) & LWP_DETACHED,
    130       1.7  kristerw 	    NULL, 0, startlwp, newuc, &l2);
    131       1.2   thorpej 
    132       1.2   thorpej 	if ((SCARG(uap, flags) & LWP_SUSPENDED) == 0) {
    133       1.2   thorpej 		SCHED_LOCK(s);
    134       1.2   thorpej 		l2->l_stat = LSRUN;
    135       1.2   thorpej 		setrunqueue(l2);
    136      1.30      yamt 		p->p_nrlwps++;
    137       1.2   thorpej 		SCHED_UNLOCK(s);
    138       1.2   thorpej 	} else {
    139       1.2   thorpej 		l2->l_stat = LSSUSPENDED;
    140       1.2   thorpej 	}
    141       1.2   thorpej 
    142       1.2   thorpej 	error = copyout(&l2->l_lid, SCARG(uap, new_lwp),
    143       1.2   thorpej 	    sizeof(l2->l_lid));
    144      1.40        ad 	if (error) {
    145      1.40        ad 		/* XXX We should destroy the LWP. */
    146       1.2   thorpej 		return (error);
    147      1.40        ad 	}
    148       1.2   thorpej 
    149       1.2   thorpej 	return (0);
    150       1.2   thorpej }
    151       1.2   thorpej 
    152       1.2   thorpej 
    153       1.2   thorpej int
    154      1.48      yamt sys__lwp_exit(struct lwp *l, void *v, register_t *retval)
    155       1.2   thorpej {
    156       1.2   thorpej 
    157       1.2   thorpej 	lwp_exit(l);
    158       1.2   thorpej 	/* NOTREACHED */
    159       1.2   thorpej 	return (0);
    160       1.2   thorpej }
    161       1.2   thorpej 
    162       1.2   thorpej 
    163       1.2   thorpej int
    164      1.48      yamt sys__lwp_self(struct lwp *l, void *v, register_t *retval)
    165       1.2   thorpej {
    166       1.2   thorpej 
    167       1.2   thorpej 	*retval = l->l_lid;
    168       1.2   thorpej 
    169       1.2   thorpej 	return (0);
    170       1.2   thorpej }
    171       1.2   thorpej 
    172       1.2   thorpej 
    173       1.2   thorpej int
    174      1.48      yamt sys__lwp_getprivate(struct lwp *l, void *v, register_t *retval)
    175       1.2   thorpej {
    176       1.2   thorpej 
    177       1.2   thorpej 	*retval = (uintptr_t) l->l_private;
    178       1.2   thorpej 
    179       1.2   thorpej 	return (0);
    180       1.2   thorpej }
    181       1.2   thorpej 
    182       1.2   thorpej 
    183       1.2   thorpej int
    184      1.48      yamt sys__lwp_setprivate(struct lwp *l, void *v, register_t *retval)
    185       1.2   thorpej {
    186       1.2   thorpej 	struct sys__lwp_setprivate_args /* {
    187       1.2   thorpej 		syscallarg(void *) ptr;
    188       1.2   thorpej 	} */ *uap = v;
    189       1.2   thorpej 
    190       1.2   thorpej 	l->l_private = SCARG(uap, ptr);
    191       1.2   thorpej 
    192       1.2   thorpej 	return (0);
    193       1.2   thorpej }
    194       1.2   thorpej 
    195       1.2   thorpej 
    196       1.2   thorpej int
    197      1.48      yamt sys__lwp_suspend(struct lwp *l, void *v, register_t *retval)
    198       1.2   thorpej {
    199       1.2   thorpej 	struct sys__lwp_suspend_args /* {
    200       1.2   thorpej 		syscallarg(lwpid_t) target;
    201       1.2   thorpej 	} */ *uap = v;
    202       1.2   thorpej 	int target_lid;
    203       1.2   thorpej 	struct proc *p = l->l_proc;
    204      1.17      manu 	struct lwp *t;
    205      1.17      manu 	struct lwp *t2;
    206       1.2   thorpej 
    207      1.33       chs 	if (p->p_flag & P_SA)
    208      1.33       chs 		return EINVAL;
    209      1.33       chs 
    210       1.2   thorpej 	target_lid = SCARG(uap, target);
    211       1.2   thorpej 
    212       1.2   thorpej 	LIST_FOREACH(t, &p->p_lwps, l_sibling)
    213       1.2   thorpej 		if (t->l_lid == target_lid)
    214       1.2   thorpej 			break;
    215       1.2   thorpej 
    216       1.2   thorpej 	if (t == NULL)
    217       1.2   thorpej 		return (ESRCH);
    218       1.2   thorpej 
    219       1.2   thorpej 	if (t == l) {
    220       1.2   thorpej 		/*
    221       1.2   thorpej 		 * Check for deadlock, which is only possible
    222       1.2   thorpej 		 * when we're suspending ourself.
    223       1.2   thorpej 		 */
    224       1.2   thorpej 		LIST_FOREACH(t2, &p->p_lwps, l_sibling) {
    225       1.2   thorpej 			if ((t2 != l) && (t2->l_stat != LSSUSPENDED))
    226       1.2   thorpej 				break;
    227       1.2   thorpej 		}
    228       1.2   thorpej 
    229       1.2   thorpej 		if (t2 == NULL) /* All other LWPs are suspended */
    230       1.2   thorpej 			return (EDEADLK);
    231      1.17      manu 	}
    232      1.17      manu 
    233      1.17      manu 	return lwp_suspend(l, t);
    234      1.17      manu }
    235       1.2   thorpej 
    236      1.17      manu inline int
    237      1.21  junyoung lwp_suspend(struct lwp *l, struct lwp *t)
    238      1.17      manu {
    239      1.17      manu 	struct proc *p = t->l_proc;
    240      1.17      manu 	int s;
    241      1.17      manu 
    242      1.17      manu 	if (t == l) {
    243       1.2   thorpej 		SCHED_LOCK(s);
    244      1.35      yamt 		KASSERT(l->l_stat == LSONPROC);
    245       1.2   thorpej 		l->l_stat = LSSUSPENDED;
    246      1.35      yamt 		p->p_nrlwps--;
    247       1.2   thorpej 		/* XXX NJWLWP check if this makes sense here: */
    248      1.17      manu 		p->p_stats->p_ru.ru_nvcsw++;
    249       1.2   thorpej 		mi_switch(l, NULL);
    250       1.2   thorpej 		SCHED_ASSERT_UNLOCKED();
    251       1.2   thorpej 		splx(s);
    252       1.2   thorpej 	} else {
    253       1.2   thorpej 		switch (t->l_stat) {
    254       1.2   thorpej 		case LSSUSPENDED:
    255       1.2   thorpej 			return (0); /* _lwp_suspend() is idempotent */
    256       1.2   thorpej 		case LSRUN:
    257       1.2   thorpej 			SCHED_LOCK(s);
    258       1.2   thorpej 			remrunqueue(t);
    259       1.2   thorpej 			t->l_stat = LSSUSPENDED;
    260      1.30      yamt 			p->p_nrlwps--;
    261       1.2   thorpej 			SCHED_UNLOCK(s);
    262       1.2   thorpej 			break;
    263       1.2   thorpej 		case LSSLEEP:
    264       1.2   thorpej 			t->l_stat = LSSUSPENDED;
    265       1.2   thorpej 			break;
    266       1.2   thorpej 		case LSIDL:
    267       1.2   thorpej 		case LSZOMB:
    268       1.2   thorpej 			return (EINTR); /* It's what Solaris does..... */
    269       1.2   thorpej 		case LSSTOP:
    270       1.2   thorpej 			panic("_lwp_suspend: Stopped LWP in running process!");
    271       1.2   thorpej 			break;
    272       1.2   thorpej 		case LSONPROC:
    273      1.29      fvdl 			/* XXX multiprocessor LWPs? Implement me! */
    274      1.29      fvdl 			return (EINVAL);
    275       1.2   thorpej 		}
    276       1.2   thorpej 	}
    277       1.2   thorpej 
    278       1.2   thorpej 	return (0);
    279       1.2   thorpej }
    280       1.2   thorpej 
    281       1.2   thorpej 
    282       1.2   thorpej int
    283      1.48      yamt sys__lwp_continue(struct lwp *l, void *v, register_t *retval)
    284       1.2   thorpej {
    285       1.2   thorpej 	struct sys__lwp_continue_args /* {
    286       1.2   thorpej 		syscallarg(lwpid_t) target;
    287       1.2   thorpej 	} */ *uap = v;
    288      1.14        cl 	int s, target_lid;
    289       1.2   thorpej 	struct proc *p = l->l_proc;
    290       1.2   thorpej 	struct lwp *t;
    291       1.2   thorpej 
    292      1.33       chs 	if (p->p_flag & P_SA)
    293      1.33       chs 		return EINVAL;
    294      1.33       chs 
    295       1.2   thorpej 	target_lid = SCARG(uap, target);
    296       1.2   thorpej 
    297       1.2   thorpej 	LIST_FOREACH(t, &p->p_lwps, l_sibling)
    298       1.2   thorpej 		if (t->l_lid == target_lid)
    299       1.2   thorpej 			break;
    300       1.2   thorpej 
    301       1.2   thorpej 	if (t == NULL)
    302       1.2   thorpej 		return (ESRCH);
    303       1.2   thorpej 
    304      1.14        cl 	SCHED_LOCK(s);
    305       1.2   thorpej 	lwp_continue(t);
    306      1.14        cl 	SCHED_UNLOCK(s);
    307       1.2   thorpej 
    308       1.2   thorpej 	return (0);
    309       1.2   thorpej }
    310       1.2   thorpej 
    311       1.2   thorpej void
    312       1.2   thorpej lwp_continue(struct lwp *l)
    313       1.2   thorpej {
    314       1.2   thorpej 
    315       1.2   thorpej 	DPRINTF(("lwp_continue of %d.%d (%s), state %d, wchan %p\n",
    316       1.2   thorpej 	    l->l_proc->p_pid, l->l_lid, l->l_proc->p_comm, l->l_stat,
    317       1.2   thorpej 	    l->l_wchan));
    318       1.2   thorpej 
    319       1.2   thorpej 	if (l->l_stat != LSSUSPENDED)
    320       1.2   thorpej 		return;
    321       1.2   thorpej 
    322       1.2   thorpej 	if (l->l_wchan == 0) {
    323       1.2   thorpej 		/* LWP was runnable before being suspended. */
    324       1.2   thorpej 		setrunnable(l);
    325       1.2   thorpej 	} else {
    326       1.2   thorpej 		/* LWP was sleeping before being suspended. */
    327       1.2   thorpej 		l->l_stat = LSSLEEP;
    328       1.2   thorpej 	}
    329       1.2   thorpej }
    330       1.2   thorpej 
    331       1.2   thorpej int
    332      1.48      yamt sys__lwp_wakeup(struct lwp *l, void *v, register_t *retval)
    333       1.2   thorpej {
    334       1.2   thorpej 	struct sys__lwp_wakeup_args /* {
    335      1.28     skrll 		syscallarg(lwpid_t) target;
    336       1.2   thorpej 	} */ *uap = v;
    337       1.2   thorpej 	lwpid_t target_lid;
    338       1.2   thorpej 	struct lwp *t;
    339       1.2   thorpej 	struct proc *p;
    340      1.10      fvdl 	int error;
    341      1.10      fvdl 	int s;
    342       1.2   thorpej 
    343       1.2   thorpej 	p = l->l_proc;
    344       1.2   thorpej 	target_lid = SCARG(uap, target);
    345       1.2   thorpej 
    346      1.10      fvdl 	SCHED_LOCK(s);
    347      1.10      fvdl 
    348       1.2   thorpej 	LIST_FOREACH(t, &p->p_lwps, l_sibling)
    349       1.2   thorpej 		if (t->l_lid == target_lid)
    350       1.2   thorpej 			break;
    351       1.2   thorpej 
    352      1.10      fvdl 	if (t == NULL) {
    353      1.10      fvdl 		error = ESRCH;
    354      1.10      fvdl 		goto exit;
    355      1.10      fvdl 	}
    356       1.2   thorpej 
    357      1.10      fvdl 	if (t->l_stat != LSSLEEP) {
    358      1.10      fvdl 		error = ENODEV;
    359      1.10      fvdl 		goto exit;
    360      1.10      fvdl 	}
    361       1.2   thorpej 
    362      1.10      fvdl 	if ((t->l_flag & L_SINTR) == 0) {
    363      1.10      fvdl 		error = EBUSY;
    364      1.10      fvdl 		goto exit;
    365      1.10      fvdl 	}
    366      1.12      matt 	/*
    367      1.12      matt 	 * Tell ltsleep to wakeup.
    368      1.12      matt 	 */
    369      1.12      matt 	t->l_flag |= L_CANCELLED;
    370       1.2   thorpej 
    371       1.4   nathanw 	setrunnable(t);
    372      1.10      fvdl 	error = 0;
    373      1.10      fvdl exit:
    374      1.10      fvdl 	SCHED_UNLOCK(s);
    375      1.10      fvdl 
    376      1.11      fvdl 	return error;
    377       1.2   thorpej }
    378       1.2   thorpej 
    379       1.2   thorpej int
    380      1.48      yamt sys__lwp_wait(struct lwp *l, void *v, register_t *retval)
    381       1.2   thorpej {
    382       1.2   thorpej 	struct sys__lwp_wait_args /* {
    383       1.2   thorpej 		syscallarg(lwpid_t) wait_for;
    384       1.2   thorpej 		syscallarg(lwpid_t *) departed;
    385       1.2   thorpej 	} */ *uap = v;
    386       1.2   thorpej 	int error;
    387       1.2   thorpej 	lwpid_t dep;
    388       1.2   thorpej 
    389       1.2   thorpej 	error = lwp_wait1(l, SCARG(uap, wait_for), &dep, 0);
    390       1.2   thorpej 	if (error)
    391       1.2   thorpej 		return (error);
    392       1.2   thorpej 
    393       1.2   thorpej 	if (SCARG(uap, departed)) {
    394       1.2   thorpej 		error = copyout(&dep, SCARG(uap, departed),
    395       1.2   thorpej 		    sizeof(dep));
    396       1.2   thorpej 		if (error)
    397       1.2   thorpej 			return (error);
    398       1.2   thorpej 	}
    399       1.2   thorpej 
    400       1.2   thorpej 	return (0);
    401       1.2   thorpej }
    402       1.2   thorpej 
    403       1.2   thorpej 
    404       1.2   thorpej int
    405       1.2   thorpej lwp_wait1(struct lwp *l, lwpid_t lid, lwpid_t *departed, int flags)
    406       1.2   thorpej {
    407       1.2   thorpej 	struct proc *p = l->l_proc;
    408       1.2   thorpej 	struct lwp *l2, *l3;
    409      1.19  jdolecek 	int nfound, error, wpri;
    410      1.18  jdolecek 	static const char waitstr1[] = "lwpwait";
    411      1.18  jdolecek 	static const char waitstr2[] = "lwpwait2";
    412       1.2   thorpej 
    413       1.2   thorpej 	DPRINTF(("lwp_wait1: %d.%d waiting for %d.\n",
    414       1.2   thorpej 	    p->p_pid, l->l_lid, lid));
    415       1.2   thorpej 
    416       1.2   thorpej 	if (lid == l->l_lid)
    417       1.2   thorpej 		return (EDEADLK); /* Waiting for ourselves makes no sense. */
    418       1.2   thorpej 
    419       1.2   thorpej 	wpri = PWAIT |
    420       1.2   thorpej 	    ((flags & LWPWAIT_EXITCONTROL) ? PNOEXITERR : PCATCH);
    421       1.2   thorpej  loop:
    422       1.2   thorpej 	nfound = 0;
    423       1.2   thorpej 	LIST_FOREACH(l2, &p->p_lwps, l_sibling) {
    424       1.2   thorpej 		if ((l2 == l) || (l2->l_flag & L_DETACHED) ||
    425       1.2   thorpej 		    ((lid != 0) && (lid != l2->l_lid)))
    426       1.2   thorpej 			continue;
    427       1.2   thorpej 
    428       1.2   thorpej 		nfound++;
    429       1.2   thorpej 		if (l2->l_stat == LSZOMB) {
    430       1.2   thorpej 			if (departed)
    431       1.2   thorpej 				*departed = l2->l_lid;
    432       1.2   thorpej 
    433      1.15       dsl 			simple_lock(&p->p_lock);
    434       1.2   thorpej 			LIST_REMOVE(l2, l_sibling);
    435       1.2   thorpej 			p->p_nlwps--;
    436       1.2   thorpej 			p->p_nzlwps--;
    437      1.15       dsl 			simple_unlock(&p->p_lock);
    438       1.2   thorpej 			/* XXX decrement limits */
    439       1.2   thorpej 
    440       1.2   thorpej 			pool_put(&lwp_pool, l2);
    441       1.2   thorpej 
    442       1.2   thorpej 			return (0);
    443       1.2   thorpej 		} else if (l2->l_stat == LSSLEEP ||
    444       1.2   thorpej 		           l2->l_stat == LSSUSPENDED) {
    445       1.2   thorpej 			/* Deadlock checks.
    446       1.2   thorpej 			 * 1. If all other LWPs are waiting for exits
    447       1.2   thorpej 			 *    or suspended, we would deadlock.
    448       1.2   thorpej 			 */
    449       1.2   thorpej 
    450       1.2   thorpej 			LIST_FOREACH(l3, &p->p_lwps, l_sibling) {
    451       1.2   thorpej 				if (l3 != l && (l3->l_stat != LSSUSPENDED) &&
    452       1.2   thorpej 				    !(l3->l_stat == LSSLEEP &&
    453       1.2   thorpej 					l3->l_wchan == (caddr_t) &p->p_nlwps))
    454       1.2   thorpej 					break;
    455       1.2   thorpej 			}
    456       1.2   thorpej 			if (l3 == NULL) /* Everyone else is waiting. */
    457       1.2   thorpej 				return (EDEADLK);
    458       1.2   thorpej 
    459       1.2   thorpej 			/* XXX we'd like to check for a cycle of waiting
    460       1.2   thorpej 			 * LWPs (specific LID waits, not any-LWP waits)
    461       1.2   thorpej 			 * and detect that sort of deadlock, but we don't
    462       1.2   thorpej 			 * have a good place to store the lwp that is
    463       1.2   thorpej 			 * being waited for. wchan is already filled with
    464       1.2   thorpej 			 * &p->p_nlwps, and putting the lwp address in
    465       1.2   thorpej 			 * there for deadlock tracing would require
    466       1.2   thorpej 			 * exiting LWPs to call wakeup on both their
    467       1.2   thorpej 			 * own address and &p->p_nlwps, to get threads
    468       1.2   thorpej 			 * sleeping on any LWP exiting.
    469       1.2   thorpej 			 *
    470       1.2   thorpej 			 * Revisit later. Maybe another auxillary
    471       1.2   thorpej 			 * storage location associated with sleeping
    472       1.2   thorpej 			 * is in order.
    473       1.2   thorpej 			 */
    474       1.2   thorpej 		}
    475       1.2   thorpej 	}
    476       1.2   thorpej 
    477       1.2   thorpej 	if (nfound == 0)
    478       1.2   thorpej 		return (ESRCH);
    479       1.2   thorpej 
    480       1.2   thorpej 	if ((error = tsleep((caddr_t) &p->p_nlwps, wpri,
    481       1.2   thorpej 	    (lid != 0) ? waitstr1 : waitstr2, 0)) != 0)
    482       1.2   thorpej 		return (error);
    483       1.2   thorpej 
    484       1.2   thorpej 	goto loop;
    485       1.2   thorpej }
    486       1.2   thorpej 
    487       1.2   thorpej 
    488       1.2   thorpej int
    489       1.2   thorpej newlwp(struct lwp *l1, struct proc *p2, vaddr_t uaddr, boolean_t inmem,
    490       1.2   thorpej     int flags, void *stack, size_t stacksize,
    491       1.2   thorpej     void (*func)(void *), void *arg, struct lwp **rnewlwpp)
    492       1.2   thorpej {
    493       1.2   thorpej 	struct lwp *l2;
    494      1.43    martin 	int s;
    495       1.2   thorpej 
    496       1.2   thorpej 	l2 = pool_get(&lwp_pool, PR_WAITOK);
    497       1.2   thorpej 
    498       1.2   thorpej 	l2->l_stat = LSIDL;
    499       1.2   thorpej 	l2->l_forw = l2->l_back = NULL;
    500       1.2   thorpej 	l2->l_proc = p2;
    501       1.2   thorpej 
    502      1.42  christos 	lwp_initspecific(l2);
    503      1.41   thorpej 
    504       1.2   thorpej 	memset(&l2->l_startzero, 0,
    505       1.2   thorpej 	       (unsigned) ((caddr_t)&l2->l_endzero -
    506       1.2   thorpej 			   (caddr_t)&l2->l_startzero));
    507       1.2   thorpej 	memcpy(&l2->l_startcopy, &l1->l_startcopy,
    508       1.2   thorpej 	       (unsigned) ((caddr_t)&l2->l_endcopy -
    509       1.2   thorpej 			   (caddr_t)&l2->l_startcopy));
    510       1.2   thorpej 
    511       1.2   thorpej #if !defined(MULTIPROCESSOR)
    512       1.2   thorpej 	/*
    513       1.2   thorpej 	 * In the single-processor case, all processes will always run
    514       1.2   thorpej 	 * on the same CPU.  So, initialize the child's CPU to the parent's
    515       1.2   thorpej 	 * now.  In the multiprocessor case, the child's CPU will be
    516       1.2   thorpej 	 * initialized in the low-level context switch code when the
    517       1.2   thorpej 	 * process runs.
    518       1.2   thorpej 	 */
    519       1.5      matt 	KASSERT(l1->l_cpu != NULL);
    520       1.2   thorpej 	l2->l_cpu = l1->l_cpu;
    521       1.2   thorpej #else
    522       1.2   thorpej 	/*
    523      1.24       wiz 	 * zero child's CPU pointer so we don't get trash.
    524       1.2   thorpej 	 */
    525       1.2   thorpej 	l2->l_cpu = NULL;
    526       1.2   thorpej #endif /* ! MULTIPROCESSOR */
    527       1.2   thorpej 
    528       1.2   thorpej 	l2->l_flag = inmem ? L_INMEM : 0;
    529       1.2   thorpej 	l2->l_flag |= (flags & LWP_DETACHED) ? L_DETACHED : 0;
    530       1.2   thorpej 
    531      1.37        ad 	lwp_update_creds(l2);
    532       1.2   thorpej 	callout_init(&l2->l_tsleep_ch);
    533       1.2   thorpej 
    534       1.2   thorpej 	if (rnewlwpp != NULL)
    535       1.2   thorpej 		*rnewlwpp = l2;
    536       1.2   thorpej 
    537      1.36      yamt 	l2->l_addr = UAREA_TO_USER(uaddr);
    538       1.2   thorpej 	uvm_lwp_fork(l1, l2, stack, stacksize, func,
    539       1.2   thorpej 	    (arg != NULL) ? arg : l2);
    540       1.2   thorpej 
    541      1.15       dsl 	simple_lock(&p2->p_lock);
    542       1.2   thorpej 	l2->l_lid = ++p2->p_nlwpid;
    543       1.2   thorpej 	LIST_INSERT_HEAD(&p2->p_lwps, l2, l_sibling);
    544       1.2   thorpej 	p2->p_nlwps++;
    545      1.15       dsl 	simple_unlock(&p2->p_lock);
    546       1.2   thorpej 
    547       1.2   thorpej 	/* XXX should be locked differently... */
    548       1.2   thorpej 	s = proclist_lock_write();
    549       1.2   thorpej 	LIST_INSERT_HEAD(&alllwp, l2, l_list);
    550       1.2   thorpej 	proclist_unlock_write(s);
    551       1.2   thorpej 
    552      1.16      manu 	if (p2->p_emul->e_lwp_fork)
    553      1.16      manu 		(*p2->p_emul->e_lwp_fork)(l1, l2);
    554      1.16      manu 
    555       1.2   thorpej 	return (0);
    556       1.2   thorpej }
    557       1.2   thorpej 
    558       1.2   thorpej 
    559       1.2   thorpej /*
    560       1.2   thorpej  * Quit the process. This will call cpu_exit, which will call cpu_switch,
    561       1.2   thorpej  * so this can only be used meaningfully if you're willing to switch away.
    562       1.2   thorpej  * Calling with l!=curlwp would be weird.
    563       1.2   thorpej  */
    564       1.2   thorpej void
    565       1.2   thorpej lwp_exit(struct lwp *l)
    566       1.2   thorpej {
    567       1.2   thorpej 	struct proc *p = l->l_proc;
    568       1.2   thorpej 	int s;
    569       1.2   thorpej 
    570       1.2   thorpej 	DPRINTF(("lwp_exit: %d.%d exiting.\n", p->p_pid, l->l_lid));
    571       1.2   thorpej 	DPRINTF((" nlwps: %d nrlwps %d nzlwps: %d\n",
    572       1.2   thorpej 	    p->p_nlwps, p->p_nrlwps, p->p_nzlwps));
    573       1.2   thorpej 
    574      1.16      manu 	if (p->p_emul->e_lwp_exit)
    575      1.16      manu 		(*p->p_emul->e_lwp_exit)(l);
    576      1.16      manu 
    577       1.2   thorpej 	/*
    578       1.2   thorpej 	 * If we are the last live LWP in a process, we need to exit
    579       1.2   thorpej 	 * the entire process (if that's not already going on). We do
    580       1.2   thorpej 	 * so with an exit status of zero, because it's a "controlled"
    581       1.2   thorpej 	 * exit, and because that's what Solaris does.
    582      1.45   thorpej 	 *
    583      1.45   thorpej 	 * Note: the last LWP's specificdata will be deleted here.
    584       1.2   thorpej 	 */
    585       1.2   thorpej 	if (((p->p_nlwps - p->p_nzlwps) == 1) && ((p->p_flag & P_WEXIT) == 0)) {
    586       1.2   thorpej 		DPRINTF(("lwp_exit: %d.%d calling exit1()\n",
    587       1.2   thorpej 		    p->p_pid, l->l_lid));
    588       1.2   thorpej 		exit1(l, 0);
    589      1.19  jdolecek 		/* NOTREACHED */
    590       1.2   thorpej 	}
    591       1.2   thorpej 
    592      1.45   thorpej 	/* Delete the specificdata while it's still safe to sleep. */
    593      1.45   thorpej 	specificdata_fini(lwp_specificdata_domain, &l->l_specdataref);
    594      1.45   thorpej 
    595       1.2   thorpej 	s = proclist_lock_write();
    596       1.2   thorpej 	LIST_REMOVE(l, l_list);
    597       1.2   thorpej 	proclist_unlock_write(s);
    598       1.2   thorpej 
    599      1.37        ad 	/*
    600      1.37        ad 	 * Release our cached credentials, and collate accounting flags.
    601      1.37        ad 	 */
    602      1.37        ad 	kauth_cred_free(l->l_cred);
    603      1.37        ad 	simple_lock(&p->p_lock);
    604      1.37        ad 	p->p_acflag |= l->l_acflag;
    605      1.37        ad 	simple_unlock(&p->p_lock);
    606      1.37        ad 
    607      1.19  jdolecek 	/* Free MD LWP resources */
    608      1.19  jdolecek #ifndef __NO_CPU_LWP_FREE
    609      1.19  jdolecek 	cpu_lwp_free(l, 0);
    610      1.19  jdolecek #endif
    611      1.19  jdolecek 
    612      1.31      yamt 	pmap_deactivate(l);
    613      1.31      yamt 
    614      1.31      yamt 	if (l->l_flag & L_DETACHED) {
    615      1.31      yamt 		simple_lock(&p->p_lock);
    616      1.31      yamt 		LIST_REMOVE(l, l_sibling);
    617      1.31      yamt 		p->p_nlwps--;
    618      1.31      yamt 		simple_unlock(&p->p_lock);
    619      1.31      yamt 
    620      1.31      yamt 		curlwp = NULL;
    621      1.31      yamt 		l->l_proc = NULL;
    622      1.31      yamt 	}
    623      1.31      yamt 
    624      1.30      yamt 	SCHED_LOCK(s);
    625       1.2   thorpej 	p->p_nrlwps--;
    626       1.2   thorpej 	l->l_stat = LSDEAD;
    627      1.30      yamt 	SCHED_UNLOCK(s);
    628       1.2   thorpej 
    629       1.2   thorpej 	/* This LWP no longer needs to hold the kernel lock. */
    630       1.2   thorpej 	KERNEL_PROC_UNLOCK(l);
    631       1.2   thorpej 
    632       1.2   thorpej 	/* cpu_exit() will not return */
    633      1.19  jdolecek 	cpu_exit(l);
    634       1.2   thorpej }
    635       1.2   thorpej 
    636      1.19  jdolecek /*
    637      1.19  jdolecek  * We are called from cpu_exit() once it is safe to schedule the
    638      1.19  jdolecek  * dead process's resources to be freed (i.e., once we've switched to
    639      1.19  jdolecek  * the idle PCB for the current CPU).
    640      1.19  jdolecek  *
    641      1.19  jdolecek  * NOTE: One must be careful with locking in this routine.  It's
    642      1.19  jdolecek  * called from a critical section in machine-dependent code, so
    643      1.19  jdolecek  * we should refrain from changing any interrupt state.
    644      1.19  jdolecek  */
    645       1.2   thorpej void
    646       1.2   thorpej lwp_exit2(struct lwp *l)
    647       1.2   thorpej {
    648      1.19  jdolecek 	struct proc *p;
    649       1.2   thorpej 
    650      1.22      yamt 	KERNEL_LOCK(LK_EXCLUSIVE);
    651      1.19  jdolecek 	/*
    652      1.19  jdolecek 	 * Free the VM resources we're still holding on to.
    653      1.19  jdolecek 	 */
    654      1.19  jdolecek 	uvm_lwp_exit(l);
    655      1.19  jdolecek 
    656      1.19  jdolecek 	if (l->l_flag & L_DETACHED) {
    657      1.19  jdolecek 		/* Nobody waits for detached LWPs. */
    658      1.19  jdolecek 		pool_put(&lwp_pool, l);
    659      1.22      yamt 		KERNEL_UNLOCK();
    660      1.19  jdolecek 	} else {
    661      1.26  junyoung 		l->l_stat = LSZOMB;
    662      1.19  jdolecek 		p = l->l_proc;
    663      1.19  jdolecek 		p->p_nzlwps++;
    664      1.49        ad 		wakeup(&p->p_nlwps);
    665      1.22      yamt 		KERNEL_UNLOCK();
    666      1.19  jdolecek 	}
    667       1.2   thorpej }
    668       1.2   thorpej 
    669       1.2   thorpej /*
    670       1.2   thorpej  * Pick a LWP to represent the process for those operations which
    671       1.2   thorpej  * want information about a "process" that is actually associated
    672       1.2   thorpej  * with a LWP.
    673       1.2   thorpej  */
    674       1.2   thorpej struct lwp *
    675      1.21  junyoung proc_representative_lwp(struct proc *p)
    676       1.2   thorpej {
    677       1.2   thorpej 	struct lwp *l, *onproc, *running, *sleeping, *stopped, *suspended;
    678      1.27      matt 	struct lwp *signalled;
    679       1.2   thorpej 
    680       1.2   thorpej 	/* Trivial case: only one LWP */
    681       1.2   thorpej 	if (p->p_nlwps == 1)
    682       1.2   thorpej 		return (LIST_FIRST(&p->p_lwps));
    683       1.2   thorpej 
    684       1.2   thorpej 	switch (p->p_stat) {
    685       1.2   thorpej 	case SSTOP:
    686       1.2   thorpej 	case SACTIVE:
    687       1.2   thorpej 		/* Pick the most live LWP */
    688       1.2   thorpej 		onproc = running = sleeping = stopped = suspended = NULL;
    689      1.27      matt 		signalled = NULL;
    690       1.2   thorpej 		LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    691      1.27      matt 			if (l->l_lid == p->p_sigctx.ps_lwp)
    692      1.27      matt 				signalled = l;
    693       1.2   thorpej 			switch (l->l_stat) {
    694       1.2   thorpej 			case LSONPROC:
    695       1.2   thorpej 				onproc = l;
    696       1.2   thorpej 				break;
    697       1.2   thorpej 			case LSRUN:
    698       1.2   thorpej 				running = l;
    699       1.2   thorpej 				break;
    700       1.2   thorpej 			case LSSLEEP:
    701       1.2   thorpej 				sleeping = l;
    702       1.2   thorpej 				break;
    703       1.2   thorpej 			case LSSTOP:
    704       1.2   thorpej 				stopped = l;
    705       1.2   thorpej 				break;
    706       1.2   thorpej 			case LSSUSPENDED:
    707       1.2   thorpej 				suspended = l;
    708       1.2   thorpej 				break;
    709       1.2   thorpej 			}
    710       1.2   thorpej 		}
    711      1.27      matt 		if (signalled)
    712      1.27      matt 			return signalled;
    713       1.3   nathanw 		if (onproc)
    714       1.3   nathanw 			return onproc;
    715       1.3   nathanw 		if (running)
    716       1.3   nathanw 			return running;
    717       1.3   nathanw 		if (sleeping)
    718       1.3   nathanw 			return sleeping;
    719       1.3   nathanw 		if (stopped)
    720       1.3   nathanw 			return stopped;
    721       1.3   nathanw 		if (suspended)
    722       1.3   nathanw 			return suspended;
    723       1.2   thorpej 		break;
    724       1.2   thorpej 	case SZOMB:
    725       1.2   thorpej 		/* Doesn't really matter... */
    726       1.2   thorpej 		return (LIST_FIRST(&p->p_lwps));
    727       1.2   thorpej #ifdef DIAGNOSTIC
    728  1.49.2.1    bouyer 	case SDYING:
    729       1.2   thorpej 	case SIDL:
    730       1.2   thorpej 		/* We have more than one LWP and we're in SIDL?
    731       1.2   thorpej 		 * How'd that happen?
    732       1.2   thorpej 		 */
    733       1.2   thorpej 		panic("Too many LWPs (%d) in SIDL process %d (%s)",
    734       1.2   thorpej 		    p->p_nrlwps, p->p_pid, p->p_comm);
    735       1.2   thorpej 	default:
    736       1.2   thorpej 		panic("Process %d (%s) in unknown state %d",
    737       1.2   thorpej 		    p->p_pid, p->p_comm, p->p_stat);
    738       1.2   thorpej #endif
    739       1.2   thorpej 	}
    740       1.2   thorpej 
    741       1.2   thorpej 	panic("proc_representative_lwp: couldn't find a lwp for process"
    742       1.2   thorpej 		" %d (%s)", p->p_pid, p->p_comm);
    743       1.2   thorpej 	/* NOTREACHED */
    744       1.2   thorpej 	return NULL;
    745       1.2   thorpej }
    746      1.37        ad 
    747      1.37        ad /*
    748      1.37        ad  * Update an LWP's cached credentials to mirror the process' master copy.
    749      1.37        ad  *
    750      1.37        ad  * This happens early in the syscall path, on user trap, and on LWP
    751      1.37        ad  * creation.  A long-running LWP can also voluntarily choose to update
    752      1.37        ad  * it's credentials by calling this routine.  This may be called from
    753      1.37        ad  * LWP_CACHE_CREDS(), which checks l->l_cred != p->p_cred beforehand.
    754      1.37        ad  */
    755      1.37        ad void
    756      1.37        ad lwp_update_creds(struct lwp *l)
    757      1.37        ad {
    758      1.37        ad 	kauth_cred_t oc;
    759      1.37        ad 	struct proc *p;
    760      1.37        ad 
    761      1.37        ad 	p = l->l_proc;
    762      1.37        ad 	oc = l->l_cred;
    763      1.37        ad 
    764      1.37        ad 	simple_lock(&p->p_lock);
    765      1.37        ad 	kauth_cred_hold(p->p_cred);
    766      1.37        ad 	l->l_cred = p->p_cred;
    767      1.37        ad 	simple_unlock(&p->p_lock);
    768      1.37        ad 	if (oc != NULL)
    769      1.37        ad 		kauth_cred_free(oc);
    770      1.37        ad }
    771      1.41   thorpej 
    772      1.41   thorpej /*
    773      1.41   thorpej  * lwp_specific_key_create --
    774      1.41   thorpej  *	Create a key for subsystem lwp-specific data.
    775      1.41   thorpej  */
    776      1.41   thorpej int
    777      1.41   thorpej lwp_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
    778      1.41   thorpej {
    779      1.41   thorpej 
    780      1.45   thorpej 	return (specificdata_key_create(lwp_specificdata_domain, keyp, dtor));
    781      1.41   thorpej }
    782      1.41   thorpej 
    783      1.41   thorpej /*
    784      1.41   thorpej  * lwp_specific_key_delete --
    785      1.41   thorpej  *	Delete a key for subsystem lwp-specific data.
    786      1.41   thorpej  */
    787      1.41   thorpej void
    788      1.41   thorpej lwp_specific_key_delete(specificdata_key_t key)
    789      1.41   thorpej {
    790      1.41   thorpej 
    791      1.41   thorpej 	specificdata_key_delete(lwp_specificdata_domain, key);
    792      1.41   thorpej }
    793      1.41   thorpej 
    794      1.45   thorpej /*
    795      1.45   thorpej  * lwp_initspecific --
    796      1.45   thorpej  *	Initialize an LWP's specificdata container.
    797      1.45   thorpej  */
    798      1.42  christos void
    799      1.42  christos lwp_initspecific(struct lwp *l)
    800      1.42  christos {
    801      1.42  christos 	int error;
    802      1.45   thorpej 
    803      1.42  christos 	error = specificdata_init(lwp_specificdata_domain, &l->l_specdataref);
    804      1.42  christos 	KASSERT(error == 0);
    805      1.42  christos }
    806      1.42  christos 
    807      1.41   thorpej /*
    808      1.45   thorpej  * lwp_finispecific --
    809      1.45   thorpej  *	Finalize an LWP's specificdata container.
    810      1.45   thorpej  */
    811      1.45   thorpej void
    812      1.45   thorpej lwp_finispecific(struct lwp *l)
    813      1.45   thorpej {
    814      1.45   thorpej 
    815      1.45   thorpej 	specificdata_fini(lwp_specificdata_domain, &l->l_specdataref);
    816      1.45   thorpej }
    817      1.45   thorpej 
    818      1.45   thorpej /*
    819      1.41   thorpej  * lwp_getspecific --
    820      1.41   thorpej  *	Return lwp-specific data corresponding to the specified key.
    821      1.41   thorpej  *
    822      1.41   thorpej  *	Note: LWP specific data is NOT INTERLOCKED.  An LWP should access
    823      1.41   thorpej  *	only its OWN SPECIFIC DATA.  If it is necessary to access another
    824      1.41   thorpej  *	LWP's specifc data, care must be taken to ensure that doing so
    825      1.41   thorpej  *	would not cause internal data structure inconsistency (i.e. caller
    826      1.41   thorpej  *	can guarantee that the target LWP is not inside an lwp_getspecific()
    827      1.41   thorpej  *	or lwp_setspecific() call).
    828      1.41   thorpej  */
    829      1.41   thorpej void *
    830      1.44   thorpej lwp_getspecific(specificdata_key_t key)
    831      1.41   thorpej {
    832      1.41   thorpej 
    833      1.41   thorpej 	return (specificdata_getspecific_unlocked(lwp_specificdata_domain,
    834      1.44   thorpej 						  &curlwp->l_specdataref, key));
    835      1.41   thorpej }
    836      1.41   thorpej 
    837      1.47   hannken void *
    838      1.47   hannken _lwp_getspecific_by_lwp(struct lwp *l, specificdata_key_t key)
    839      1.47   hannken {
    840      1.47   hannken 
    841      1.47   hannken 	return (specificdata_getspecific_unlocked(lwp_specificdata_domain,
    842      1.47   hannken 						  &l->l_specdataref, key));
    843      1.47   hannken }
    844      1.47   hannken 
    845      1.41   thorpej /*
    846      1.41   thorpej  * lwp_setspecific --
    847      1.41   thorpej  *	Set lwp-specific data corresponding to the specified key.
    848      1.41   thorpej  */
    849      1.41   thorpej void
    850      1.45   thorpej lwp_setspecific(specificdata_key_t key, void *data)
    851      1.41   thorpej {
    852      1.41   thorpej 
    853      1.41   thorpej 	specificdata_setspecific(lwp_specificdata_domain,
    854      1.44   thorpej 				 &curlwp->l_specdataref, key, data);
    855      1.41   thorpej }
    856