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6b286ee8b5
not blocking the signal, signal is placed on the thread sigqueue. If the selected thread is in kernel executing thr_exit() or sigprocmask() syscalls, then signal might be not delivered to usermode for arbitrary amount of time, and for exiting thread it is lost. Put process-directed signals to the process queue unconditionally, selecting the thread to deliver the signal only by the thread returning to usermode, since only then the thread can handle delivery of signal reliably. For exiting thread or thread that has blocked some signals, check whether the newly blocked signal is queued for the process, and try to find a thread to wakeup for delivery, in reschedule_signal(). For exiting thread, assume that all signals are blocked. Change cursig() and postsig() to look both into the thread and process signal queues. When there is a signal that thread returning to usermode could consume, TDF_NEEDSIGCHK flag is not neccessary set now. Do unlocked read of p_siglist and p_pendingcnt to check for queued signals. Note that thread that has a signal unblocked might get spurious wakeup and EINTR from the interruptible system call now, due to the possibility of being selected by reschedule_signals(), while other thread returned to usermode earlier and removed the signal from process queue. This should not cause compliance issues, since the thread has not blocked a signal and thus should be ready to receive it anyway. Reported by: Justin Teller <justin.teller gmail com> Reviewed by: davidxu, jilles MFC after: 1 month
513 lines
11 KiB
C
513 lines
11 KiB
C
/*-
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* Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_compat.h"
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#include "opt_posix.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/posix4.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/smp.h>
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#include <sys/syscallsubr.h>
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#include <sys/sysent.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/signalvar.h>
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#include <sys/ucontext.h>
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#include <sys/thr.h>
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#include <sys/rtprio.h>
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#include <sys/umtx.h>
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#include <sys/limits.h>
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#include <machine/frame.h>
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#include <security/audit/audit.h>
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#ifdef COMPAT_IA32
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static inline int
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suword_lwpid(void *addr, lwpid_t lwpid)
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{
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int error;
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if (SV_CURPROC_FLAG(SV_LP64))
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error = suword(addr, lwpid);
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else
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error = suword32(addr, lwpid);
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return (error);
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}
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#else
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#define suword_lwpid suword
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#endif
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extern int max_threads_per_proc;
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extern int max_threads_hits;
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static int create_thread(struct thread *td, mcontext_t *ctx,
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void (*start_func)(void *), void *arg,
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char *stack_base, size_t stack_size,
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char *tls_base,
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long *child_tid, long *parent_tid,
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int flags, struct rtprio *rtp);
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/*
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* System call interface.
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*/
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int
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thr_create(struct thread *td, struct thr_create_args *uap)
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/* ucontext_t *ctx, long *id, int flags */
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{
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ucontext_t ctx;
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int error;
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if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
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return (error);
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error = create_thread(td, &ctx.uc_mcontext, NULL, NULL,
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NULL, 0, NULL, uap->id, NULL, uap->flags, NULL);
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return (error);
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}
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int
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thr_new(struct thread *td, struct thr_new_args *uap)
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/* struct thr_param * */
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{
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struct thr_param param;
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int error;
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if (uap->param_size < 0 || uap->param_size > sizeof(param))
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return (EINVAL);
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bzero(¶m, sizeof(param));
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if ((error = copyin(uap->param, ¶m, uap->param_size)))
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return (error);
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return (kern_thr_new(td, ¶m));
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}
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int
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kern_thr_new(struct thread *td, struct thr_param *param)
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{
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struct rtprio rtp, *rtpp;
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int error;
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rtpp = NULL;
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if (param->rtp != 0) {
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error = copyin(param->rtp, &rtp, sizeof(struct rtprio));
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if (error)
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return (error);
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rtpp = &rtp;
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}
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error = create_thread(td, NULL, param->start_func, param->arg,
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param->stack_base, param->stack_size, param->tls_base,
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param->child_tid, param->parent_tid, param->flags,
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rtpp);
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return (error);
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}
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static int
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create_thread(struct thread *td, mcontext_t *ctx,
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void (*start_func)(void *), void *arg,
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char *stack_base, size_t stack_size,
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char *tls_base,
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long *child_tid, long *parent_tid,
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int flags, struct rtprio *rtp)
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{
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stack_t stack;
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struct thread *newtd;
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struct proc *p;
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int error;
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p = td->td_proc;
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/* Have race condition but it is cheap. */
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if (p->p_numthreads >= max_threads_per_proc) {
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++max_threads_hits;
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return (EPROCLIM);
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}
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if (rtp != NULL) {
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switch(rtp->type) {
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case RTP_PRIO_REALTIME:
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case RTP_PRIO_FIFO:
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/* Only root can set scheduler policy */
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if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0)
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return (EPERM);
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if (rtp->prio > RTP_PRIO_MAX)
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return (EINVAL);
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break;
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case RTP_PRIO_NORMAL:
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rtp->prio = 0;
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break;
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default:
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return (EINVAL);
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}
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}
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/* Initialize our td */
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newtd = thread_alloc(0);
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if (newtd == NULL)
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return (ENOMEM);
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/*
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* Try the copyout as soon as we allocate the td so we don't
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* have to tear things down in a failure case below.
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* Here we copy out tid to two places, one for child and one
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* for parent, because pthread can create a detached thread,
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* if parent wants to safely access child tid, it has to provide
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* its storage, because child thread may exit quickly and
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* memory is freed before parent thread can access it.
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*/
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if ((child_tid != NULL &&
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suword_lwpid(child_tid, newtd->td_tid)) ||
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(parent_tid != NULL &&
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suword_lwpid(parent_tid, newtd->td_tid))) {
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thread_free(newtd);
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return (EFAULT);
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}
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bzero(&newtd->td_startzero,
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__rangeof(struct thread, td_startzero, td_endzero));
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bcopy(&td->td_startcopy, &newtd->td_startcopy,
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__rangeof(struct thread, td_startcopy, td_endcopy));
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newtd->td_proc = td->td_proc;
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newtd->td_ucred = crhold(td->td_ucred);
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cpu_set_upcall(newtd, td);
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if (ctx != NULL) { /* old way to set user context */
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error = set_mcontext(newtd, ctx);
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if (error != 0) {
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thread_free(newtd);
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crfree(td->td_ucred);
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return (error);
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}
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} else {
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/* Set up our machine context. */
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stack.ss_sp = stack_base;
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stack.ss_size = stack_size;
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/* Set upcall address to user thread entry function. */
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cpu_set_upcall_kse(newtd, start_func, arg, &stack);
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/* Setup user TLS address and TLS pointer register. */
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error = cpu_set_user_tls(newtd, tls_base);
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if (error != 0) {
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thread_free(newtd);
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crfree(td->td_ucred);
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return (error);
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}
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}
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PROC_LOCK(td->td_proc);
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td->td_proc->p_flag |= P_HADTHREADS;
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newtd->td_sigmask = td->td_sigmask;
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thread_link(newtd, p);
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bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
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thread_lock(td);
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/* let the scheduler know about these things. */
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sched_fork_thread(td, newtd);
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thread_unlock(td);
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if (P_SHOULDSTOP(p))
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newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
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PROC_UNLOCK(p);
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thread_lock(newtd);
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if (rtp != NULL) {
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if (!(td->td_pri_class == PRI_TIMESHARE &&
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rtp->type == RTP_PRIO_NORMAL)) {
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rtp_to_pri(rtp, newtd);
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sched_prio(newtd, newtd->td_user_pri);
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} /* ignore timesharing class */
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}
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TD_SET_CAN_RUN(newtd);
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sched_add(newtd, SRQ_BORING);
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thread_unlock(newtd);
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return (0);
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}
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int
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thr_self(struct thread *td, struct thr_self_args *uap)
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/* long *id */
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{
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int error;
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error = suword_lwpid(uap->id, (unsigned)td->td_tid);
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if (error == -1)
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return (EFAULT);
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return (0);
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}
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int
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thr_exit(struct thread *td, struct thr_exit_args *uap)
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/* long *state */
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{
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struct proc *p;
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p = td->td_proc;
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/* Signal userland that it can free the stack. */
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if ((void *)uap->state != NULL) {
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suword_lwpid(uap->state, 1);
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kern_umtx_wake(td, uap->state, INT_MAX, 0);
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}
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PROC_LOCK(p);
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tdsigcleanup(td);
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PROC_SLOCK(p);
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/*
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* Shutting down last thread in the proc. This will actually
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* call exit() in the trampoline when it returns.
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*/
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if (p->p_numthreads != 1) {
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thread_stopped(p);
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thread_exit();
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/* NOTREACHED */
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}
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PROC_SUNLOCK(p);
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PROC_UNLOCK(p);
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return (0);
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}
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int
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thr_kill(struct thread *td, struct thr_kill_args *uap)
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/* long id, int sig */
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{
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struct thread *ttd;
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struct proc *p;
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int error;
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p = td->td_proc;
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error = 0;
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PROC_LOCK(p);
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if (uap->id == -1) {
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if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
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error = EINVAL;
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} else {
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error = ESRCH;
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FOREACH_THREAD_IN_PROC(p, ttd) {
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if (ttd != td) {
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error = 0;
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if (uap->sig == 0)
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break;
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tdsignal(p, ttd, uap->sig, NULL);
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}
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}
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}
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} else {
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if (uap->id != td->td_tid)
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ttd = thread_find(p, uap->id);
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else
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ttd = td;
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if (ttd == NULL)
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error = ESRCH;
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else if (uap->sig == 0)
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;
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else if (!_SIG_VALID(uap->sig))
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error = EINVAL;
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else
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tdsignal(p, ttd, uap->sig, NULL);
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}
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PROC_UNLOCK(p);
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return (error);
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}
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int
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thr_kill2(struct thread *td, struct thr_kill2_args *uap)
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/* pid_t pid, long id, int sig */
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{
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struct thread *ttd;
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struct proc *p;
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int error;
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AUDIT_ARG_SIGNUM(uap->sig);
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if (uap->pid == td->td_proc->p_pid) {
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p = td->td_proc;
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PROC_LOCK(p);
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} else if ((p = pfind(uap->pid)) == NULL) {
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return (ESRCH);
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}
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AUDIT_ARG_PROCESS(p);
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error = p_cansignal(td, p, uap->sig);
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if (error == 0) {
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if (uap->id == -1) {
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if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
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error = EINVAL;
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} else {
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error = ESRCH;
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FOREACH_THREAD_IN_PROC(p, ttd) {
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if (ttd != td) {
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error = 0;
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if (uap->sig == 0)
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break;
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tdsignal(p, ttd, uap->sig, NULL);
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}
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}
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}
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} else {
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if (uap->id != td->td_tid)
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ttd = thread_find(p, uap->id);
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else
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ttd = td;
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if (ttd == NULL)
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error = ESRCH;
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else if (uap->sig == 0)
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;
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else if (!_SIG_VALID(uap->sig))
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error = EINVAL;
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else
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tdsignal(p, ttd, uap->sig, NULL);
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}
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}
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PROC_UNLOCK(p);
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return (error);
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}
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int
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thr_suspend(struct thread *td, struct thr_suspend_args *uap)
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/* const struct timespec *timeout */
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{
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struct timespec ts, *tsp;
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int error;
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tsp = NULL;
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if (uap->timeout != NULL) {
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error = copyin((const void *)uap->timeout, (void *)&ts,
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sizeof(struct timespec));
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if (error != 0)
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return (error);
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tsp = &ts;
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}
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return (kern_thr_suspend(td, tsp));
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}
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int
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kern_thr_suspend(struct thread *td, struct timespec *tsp)
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{
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struct timeval tv;
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int error = 0, hz = 0;
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if (tsp != NULL) {
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if (tsp->tv_nsec < 0 || tsp->tv_nsec > 1000000000)
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return (EINVAL);
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if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
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return (ETIMEDOUT);
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TIMESPEC_TO_TIMEVAL(&tv, tsp);
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hz = tvtohz(&tv);
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}
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if (td->td_pflags & TDP_WAKEUP) {
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td->td_pflags &= ~TDP_WAKEUP;
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return (0);
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}
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PROC_LOCK(td->td_proc);
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if ((td->td_flags & TDF_THRWAKEUP) == 0)
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error = msleep((void *)td, &td->td_proc->p_mtx, PCATCH, "lthr",
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hz);
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if (td->td_flags & TDF_THRWAKEUP) {
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thread_lock(td);
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td->td_flags &= ~TDF_THRWAKEUP;
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thread_unlock(td);
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PROC_UNLOCK(td->td_proc);
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return (0);
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}
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PROC_UNLOCK(td->td_proc);
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if (error == EWOULDBLOCK)
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error = ETIMEDOUT;
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else if (error == ERESTART) {
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if (hz != 0)
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error = EINTR;
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}
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return (error);
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}
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int
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thr_wake(struct thread *td, struct thr_wake_args *uap)
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/* long id */
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{
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struct proc *p;
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struct thread *ttd;
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if (uap->id == td->td_tid) {
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td->td_pflags |= TDP_WAKEUP;
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return (0);
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}
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p = td->td_proc;
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PROC_LOCK(p);
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ttd = thread_find(p, uap->id);
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if (ttd == NULL) {
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PROC_UNLOCK(p);
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return (ESRCH);
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}
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thread_lock(ttd);
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ttd->td_flags |= TDF_THRWAKEUP;
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thread_unlock(ttd);
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wakeup((void *)ttd);
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PROC_UNLOCK(p);
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return (0);
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}
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int
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thr_set_name(struct thread *td, struct thr_set_name_args *uap)
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{
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struct proc *p = td->td_proc;
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char name[MAXCOMLEN + 1];
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struct thread *ttd;
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int error;
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error = 0;
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name[0] = '\0';
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if (uap->name != NULL) {
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error = copyinstr(uap->name, name, sizeof(name),
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NULL);
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if (error)
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return (error);
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}
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PROC_LOCK(p);
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if (uap->id == td->td_tid)
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ttd = td;
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else
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ttd = thread_find(p, uap->id);
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if (ttd != NULL)
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strcpy(ttd->td_name, name);
|
|
else
|
|
error = ESRCH;
|
|
PROC_UNLOCK(p);
|
|
return (error);
|
|
}
|