Apart from minor clean up this gets rid of proc unlock/lock cycle on thread exit to work around LOR against tidhash lock.
625 lines
14 KiB
C
625 lines
14 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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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_posix.h"
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#include "opt_hwpmc_hooks.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/ptrace.h>
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#include <sys/racct.h>
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#include <sys/resourcevar.h>
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#include <sys/rwlock.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/sysctl.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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#ifdef HWPMC_HOOKS
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#include <sys/pmckern.h>
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#endif
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#include <machine/frame.h>
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#include <security/audit/audit.h>
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static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"thread allocation");
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int max_threads_per_proc = 1500;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
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&max_threads_per_proc, 0, "Limit on threads per proc");
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static int max_threads_hits;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
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&max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count");
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#ifdef COMPAT_FREEBSD32
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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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/*
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* System call interface.
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*/
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struct thr_create_initthr_args {
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ucontext_t ctx;
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long *tid;
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};
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static int
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thr_create_initthr(struct thread *td, void *thunk)
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{
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struct thr_create_initthr_args *args;
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/* Copy out the child tid. */
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args = thunk;
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if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid))
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return (EFAULT);
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return (set_mcontext(td, &args->ctx.uc_mcontext));
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}
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int
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sys_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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struct thr_create_initthr_args args;
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int error;
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if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx))))
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return (error);
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args.tid = uap->id;
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return (thread_create(td, NULL, thr_create_initthr, &args));
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}
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int
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sys_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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static int
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thr_new_initthr(struct thread *td, void *thunk)
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{
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stack_t stack;
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struct thr_param *param;
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/*
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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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param = thunk;
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if ((param->child_tid != NULL &&
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suword_lwpid(param->child_tid, td->td_tid)) ||
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(param->parent_tid != NULL &&
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suword_lwpid(param->parent_tid, td->td_tid)))
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return (EFAULT);
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/* Set up our machine context. */
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stack.ss_sp = param->stack_base;
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stack.ss_size = param->stack_size;
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/* Set upcall address to user thread entry function. */
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cpu_set_upcall(td, param->start_func, param->arg, &stack);
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/* Setup user TLS address and TLS pointer register. */
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return (cpu_set_user_tls(td, param->tls_base));
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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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return (thread_create(td, rtpp, thr_new_initthr, param));
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}
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int
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thread_create(struct thread *td, struct rtprio *rtp,
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int (*initialize_thread)(struct thread *, void *), void *thunk)
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{
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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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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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#ifdef RACCT
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if (racct_enable) {
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PROC_LOCK(p);
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error = racct_add(p, RACCT_NTHR, 1);
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PROC_UNLOCK(p);
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if (error != 0)
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return (EPROCLIM);
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}
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#endif
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/* Initialize our td */
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error = kern_thr_alloc(p, 0, &newtd);
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if (error)
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goto fail;
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cpu_copy_thread(newtd, td);
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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_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0;
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thread_cow_get(newtd, td);
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error = initialize_thread(newtd, thunk);
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if (error != 0) {
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thread_cow_free(newtd);
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thread_free(newtd);
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goto fail;
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}
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PROC_LOCK(p);
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p->p_flag |= P_HADTHREADS;
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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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if (p->p_ptevents & PTRACE_LWP)
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newtd->td_dbgflags |= TDB_BORN;
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PROC_UNLOCK(p);
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#ifdef HWPMC_HOOKS
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if (PMC_PROC_IS_USING_PMCS(p))
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PMC_CALL_HOOK(newtd, PMC_FN_THR_CREATE, NULL);
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else if (PMC_SYSTEM_SAMPLING_ACTIVE())
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PMC_CALL_HOOK_UNLOCKED(newtd, PMC_FN_THR_CREATE_LOG, NULL);
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#endif
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tidhash_add(newtd);
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/* ignore timesharing class */
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if (rtp != NULL && !(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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thread_lock(newtd);
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TD_SET_CAN_RUN(newtd);
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sched_add(newtd, SRQ_BORING);
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return (0);
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fail:
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#ifdef RACCT
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if (racct_enable) {
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PROC_LOCK(p);
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racct_sub(p, RACCT_NTHR, 1);
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PROC_UNLOCK(p);
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}
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#endif
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return (error);
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}
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int
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sys_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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sys_thr_exit(struct thread *td, struct thr_exit_args *uap)
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/* long *state */
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{
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umtx_thread_exit(td);
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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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return (kern_thr_exit(td));
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}
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int
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kern_thr_exit(struct thread *td)
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{
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struct proc *p;
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p = td->td_proc;
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/*
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* If all of the threads in a process call this routine to
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* exit (e.g. all threads call pthread_exit()), exactly one
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* thread should return to the caller to terminate the process
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* instead of the thread.
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*
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* Checking p_numthreads alone is not sufficient since threads
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* might be committed to terminating while the PROC_LOCK is
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* dropped in either ptracestop() or while removing this thread
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* from the tidhash. Instead, the p_pendingexits field holds
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* the count of threads in either of those states and a thread
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* is considered the "last" thread if all of the other threads
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* in a process are already terminating.
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*/
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PROC_LOCK(p);
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if (p->p_numthreads == p->p_pendingexits + 1) {
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/*
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* Ignore attempts to shut down last thread in the
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* proc. This will actually call _exit(2) in the
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* usermode trampoline when it returns.
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*/
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PROC_UNLOCK(p);
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return (0);
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}
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td->td_dbgflags |= TDB_EXIT;
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if (p->p_ptevents & PTRACE_LWP) {
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p->p_pendingexits++;
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ptracestop(td, SIGTRAP, NULL);
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p->p_pendingexits--;
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}
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tidhash_remove(td);
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/*
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* The check above should prevent all other threads from this
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* process from exiting while the PROC_LOCK is dropped, so
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* there must be at least one other thread other than the
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* current thread.
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*/
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KASSERT(p->p_numthreads > 1, ("too few threads"));
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racct_sub(p, RACCT_NTHR, 1);
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tdsigcleanup(td);
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#ifdef AUDIT
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AUDIT_SYSCALL_EXIT(0, td);
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#endif
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PROC_SLOCK(p);
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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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int
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sys_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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ksiginfo_t ksi;
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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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ksiginfo_init(&ksi);
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ksi.ksi_signo = uap->sig;
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ksi.ksi_code = SI_LWP;
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ksi.ksi_pid = p->p_pid;
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ksi.ksi_uid = td->td_ucred->cr_ruid;
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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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PROC_LOCK(p);
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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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tdksignal(ttd, uap->sig, &ksi);
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}
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}
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PROC_UNLOCK(p);
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}
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} else {
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error = 0;
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ttd = tdfind((lwpid_t)uap->id, p->p_pid);
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if (ttd == NULL)
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return (ESRCH);
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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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tdksignal(ttd, uap->sig, &ksi);
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PROC_UNLOCK(ttd->td_proc);
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}
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return (error);
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}
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int
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sys_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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ksiginfo_t ksi;
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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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ksiginfo_init(&ksi);
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ksi.ksi_signo = uap->sig;
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ksi.ksi_code = SI_LWP;
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ksi.ksi_pid = td->td_proc->p_pid;
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ksi.ksi_uid = td->td_ucred->cr_ruid;
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if (uap->id == -1) {
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if ((p = pfind(uap->pid)) == NULL)
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return (ESRCH);
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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) {
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PROC_UNLOCK(p);
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return (error);
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}
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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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tdksignal(ttd, uap->sig, &ksi);
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}
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}
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}
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PROC_UNLOCK(p);
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} else {
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ttd = tdfind((lwpid_t)uap->id, uap->pid);
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if (ttd == NULL)
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return (ESRCH);
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p = ttd->td_proc;
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AUDIT_ARG_PROCESS(p);
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error = p_cansignal(td, p, uap->sig);
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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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tdksignal(ttd, uap->sig, &ksi);
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PROC_UNLOCK(p);
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}
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return (error);
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}
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int
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sys_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 = umtx_copyin_timeout(uap->timeout, &ts);
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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 proc *p = td->td_proc;
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struct timeval tv;
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int error = 0;
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int timo = 0;
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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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if (tsp != NULL) {
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if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
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error = EWOULDBLOCK;
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|
else {
|
|
TIMESPEC_TO_TIMEVAL(&tv, tsp);
|
|
timo = tvtohz(&tv);
|
|
}
|
|
}
|
|
|
|
PROC_LOCK(p);
|
|
if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0)
|
|
error = msleep((void *)td, &p->p_mtx,
|
|
PCATCH, "lthr", timo);
|
|
|
|
if (td->td_flags & TDF_THRWAKEUP) {
|
|
thread_lock(td);
|
|
td->td_flags &= ~TDF_THRWAKEUP;
|
|
thread_unlock(td);
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
PROC_UNLOCK(p);
|
|
if (error == EWOULDBLOCK)
|
|
error = ETIMEDOUT;
|
|
else if (error == ERESTART) {
|
|
if (timo != 0)
|
|
error = EINTR;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
sys_thr_wake(struct thread *td, struct thr_wake_args *uap)
|
|
/* long id */
|
|
{
|
|
struct proc *p;
|
|
struct thread *ttd;
|
|
|
|
if (uap->id == td->td_tid) {
|
|
td->td_pflags |= TDP_WAKEUP;
|
|
return (0);
|
|
}
|
|
|
|
p = td->td_proc;
|
|
ttd = tdfind((lwpid_t)uap->id, p->p_pid);
|
|
if (ttd == NULL)
|
|
return (ESRCH);
|
|
thread_lock(ttd);
|
|
ttd->td_flags |= TDF_THRWAKEUP;
|
|
thread_unlock(ttd);
|
|
wakeup((void *)ttd);
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap)
|
|
{
|
|
struct proc *p;
|
|
char name[MAXCOMLEN + 1];
|
|
struct thread *ttd;
|
|
int error;
|
|
|
|
error = 0;
|
|
name[0] = '\0';
|
|
if (uap->name != NULL) {
|
|
error = copyinstr(uap->name, name, sizeof(name), NULL);
|
|
if (error == ENAMETOOLONG) {
|
|
error = copyin(uap->name, name, sizeof(name) - 1);
|
|
name[sizeof(name) - 1] = '\0';
|
|
}
|
|
if (error)
|
|
return (error);
|
|
}
|
|
p = td->td_proc;
|
|
ttd = tdfind((lwpid_t)uap->id, p->p_pid);
|
|
if (ttd == NULL)
|
|
return (ESRCH);
|
|
strcpy(ttd->td_name, name);
|
|
#ifdef HWPMC_HOOKS
|
|
if (PMC_PROC_IS_USING_PMCS(p) || PMC_SYSTEM_SAMPLING_ACTIVE())
|
|
PMC_CALL_HOOK_UNLOCKED(ttd, PMC_FN_THR_CREATE_LOG, NULL);
|
|
#endif
|
|
#ifdef KTR
|
|
sched_clear_tdname(ttd);
|
|
#endif
|
|
PROC_UNLOCK(p);
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
kern_thr_alloc(struct proc *p, int pages, struct thread **ntd)
|
|
{
|
|
|
|
/* Have race condition but it is cheap. */
|
|
if (p->p_numthreads >= max_threads_per_proc) {
|
|
++max_threads_hits;
|
|
return (EPROCLIM);
|
|
}
|
|
|
|
*ntd = thread_alloc(pages);
|
|
if (*ntd == NULL)
|
|
return (ENOMEM);
|
|
|
|
return (0);
|
|
}
|