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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/syscall.h>
#include <sys/proc.h>
#include <sys/processor.h>
#include <sys/fault.h>
#include <sys/ucontext.h>
#include <sys/signal.h>
#include <sys/unistd.h>
#include <sys/procfs.h>
#include <sys/prsystm.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/klwp.h>
#include <sys/pool.h>
/*
* System call to create an lwp.
*
* Notes on the LWP_DETACHED and LWP_DAEMON flags:
*
* A detached lwp (LWP_DETACHED) cannot be the specific target of
* lwp_wait() (it is not joinable), but lwp_wait(0, ...) is required
* to sleep until all non-daemon detached lwps have terminated before
* returning EDEADLK because a detached lwp might create a non-detached lwp
* that could then be returned by lwp_wait(0, ...). See also lwp_detach().
*
* A daemon lwp (LWP_DAEMON) is a detached lwp that has the additional
* property that it does not affect the termination condition of the
* process: The last non-daemon lwp to call lwp_exit() causes the process
* to exit and lwp_wait(0, ...) does not sleep waiting for daemon lwps
* to terminate. See the block comment before lwp_wait().
*/
int
syslwp_create(ucontext_t *ucp, int flags, id_t *new_lwp)
{
klwp_t *lwp;
proc_t *p = ttoproc(curthread);
kthread_t *t;
ucontext_t uc;
#ifdef _SYSCALL32_IMPL
ucontext32_t uc32;
#endif /* _SYSCALL32_IMPL */
k_sigset_t sigmask;
int tid;
model_t model = get_udatamodel();
uintptr_t thrptr = 0;
if (flags & ~(LWP_DAEMON|LWP_DETACHED|LWP_SUSPENDED))
return (set_errno(EINVAL));
/*
* lwp_create() is disallowed for the /proc agent lwp.
*/
if (curthread == p->p_agenttp)
return (set_errno(ENOTSUP));
if (model == DATAMODEL_NATIVE) {
if (copyin(ucp, &uc, sizeof (ucontext_t)))
return (set_errno(EFAULT));
sigutok(&uc.uc_sigmask, &sigmask);
#if defined(__i386)
/*
* libc stashed thrptr into unused kernel %sp.
* See setup_context() in libc.
*/
thrptr = (uint32_t)uc.uc_mcontext.gregs[ESP];
#endif
}
#ifdef _SYSCALL32_IMPL
else {
if (copyin(ucp, &uc32, sizeof (ucontext32_t)))
return (set_errno(EFAULT));
sigutok(&uc32.uc_sigmask, &sigmask);
#if defined(__sparc)
ucontext_32ton(&uc32, &uc, NULL, NULL);
#else /* __amd64 */
ucontext_32ton(&uc32, &uc);
/*
* libc stashed thrptr into unused kernel %sp.
* See setup_context() in libc.
*/
thrptr = (uint32_t)uc32.uc_mcontext.gregs[ESP];
#endif
}
#endif /* _SYSCALL32_IMPL */
(void) save_syscall_args(); /* save args for tracing first */
mutex_enter(&curproc->p_lock);
pool_barrier_enter();
mutex_exit(&curproc->p_lock);
lwp = lwp_create(lwp_rtt, NULL, NULL, curproc, TS_STOPPED,
curthread->t_pri, &sigmask, curthread->t_cid, 0);
mutex_enter(&curproc->p_lock);
pool_barrier_exit();
mutex_exit(&curproc->p_lock);
if (lwp == NULL)
return (set_errno(EAGAIN));
lwp_load(lwp, uc.uc_mcontext.gregs, thrptr);
t = lwptot(lwp);
/*
* Copy the new lwp's lwpid into the caller's specified buffer.
*/
if (new_lwp && copyout(&t->t_tid, new_lwp, sizeof (id_t))) {
/*
* caller's buffer is not writable, return
* EFAULT, and terminate new lwp.
*/
mutex_enter(&p->p_lock);
t->t_proc_flag |= TP_EXITLWP;
t->t_sig_check = 1;
t->t_sysnum = 0;
t->t_proc_flag &= ~TP_HOLDLWP;
lwp_create_done(t);
mutex_exit(&p->p_lock);
return (set_errno(EFAULT));
}
/*
* clone callers context, if any. must be invoked
* while -not- holding p_lock.
*/
if (curthread->t_ctx)
lwp_createctx(curthread, t);
/*
* copy current contract templates
*/
lwp_ctmpl_copy(lwp, ttolwp(curthread));
mutex_enter(&p->p_lock);
/*
* Copy the syscall arguments to the new lwp's arg area
* for the benefit of debuggers.
*/
t->t_sysnum = SYS_lwp_create;
lwp->lwp_ap = lwp->lwp_arg;
lwp->lwp_arg[0] = (long)ucp;
lwp->lwp_arg[1] = (long)flags;
lwp->lwp_arg[2] = (long)new_lwp;
lwp->lwp_argsaved = 1;
if (!(flags & (LWP_DETACHED|LWP_DAEMON)))
t->t_proc_flag |= TP_TWAIT;
if (flags & LWP_DAEMON) {
t->t_proc_flag |= TP_DAEMON;
p->p_lwpdaemon++;
}
tid = (int)t->t_tid; /* for /proc debuggers */
/*
* We now set the newly-created lwp running.
* If it is being created as LWP_SUSPENDED, we leave its
* TP_HOLDLWP flag set so it will stop in system call exit.
*/
if (!(flags & LWP_SUSPENDED))
t->t_proc_flag &= ~TP_HOLDLWP;
lwp_create_done(t);
mutex_exit(&p->p_lock);
return (tid);
}
/*
* Exit the calling lwp
*/
void
syslwp_exit()
{
proc_t *p = ttoproc(curthread);
mutex_enter(&p->p_lock);
lwp_exit();
/* NOTREACHED */
}
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