5b1618d74b
a syscall is from UTS kernel.
1877 lines
47 KiB
C
1877 lines
47 KiB
C
/*
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* Copyright (C) 2001 Julian Elischer <julian@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(s), this list of conditions and the following disclaimer as
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* the first lines of this file unmodified other than the possible
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* addition of one or more copyright notices.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice(s), 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 COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/smp.h>
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#include <sys/sysctl.h>
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#include <sys/sysproto.h>
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#include <sys/filedesc.h>
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#include <sys/sched.h>
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#include <sys/signalvar.h>
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#include <sys/sx.h>
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#include <sys/tty.h>
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#include <sys/user.h>
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#include <sys/jail.h>
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#include <sys/kse.h>
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#include <sys/ktr.h>
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#include <sys/ucontext.h>
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#include <vm/vm.h>
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#include <vm/vm_object.h>
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#include <vm/pmap.h>
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#include <vm/uma.h>
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#include <vm/vm_map.h>
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#include <machine/frame.h>
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/*
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* KSEGRP related storage.
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*/
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static uma_zone_t ksegrp_zone;
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static uma_zone_t kse_zone;
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static uma_zone_t thread_zone;
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/* DEBUG ONLY */
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SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation");
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static int thread_debug = 0;
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SYSCTL_INT(_kern_threads, OID_AUTO, debug, CTLFLAG_RW,
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&thread_debug, 0, "thread debug");
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static int max_threads_per_proc = 30;
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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_groups_per_proc = 5;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_groups_per_proc, CTLFLAG_RW,
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&max_groups_per_proc, 0, "Limit on thread groups per proc");
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#define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
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struct threadqueue zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads);
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TAILQ_HEAD(, kse) zombie_kses = TAILQ_HEAD_INITIALIZER(zombie_kses);
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TAILQ_HEAD(, ksegrp) zombie_ksegrps = TAILQ_HEAD_INITIALIZER(zombie_ksegrps);
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struct mtx zombie_thread_lock;
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MTX_SYSINIT(zombie_thread_lock, &zombie_thread_lock,
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"zombie_thread_lock", MTX_SPIN);
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static void kse_purge(struct proc *p, struct thread *td);
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/*
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* Prepare a thread for use.
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*/
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static void
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thread_ctor(void *mem, int size, void *arg)
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{
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struct thread *td;
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td = (struct thread *)mem;
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td->td_state = TDS_INACTIVE;
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td->td_flags |= TDF_UNBOUND;
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}
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/*
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* Reclaim a thread after use.
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*/
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static void
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thread_dtor(void *mem, int size, void *arg)
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{
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struct thread *td;
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td = (struct thread *)mem;
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#ifdef INVARIANTS
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/* Verify that this thread is in a safe state to free. */
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switch (td->td_state) {
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case TDS_INHIBITED:
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case TDS_RUNNING:
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case TDS_CAN_RUN:
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case TDS_RUNQ:
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/*
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* We must never unlink a thread that is in one of
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* these states, because it is currently active.
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*/
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panic("bad state for thread unlinking");
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/* NOTREACHED */
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case TDS_INACTIVE:
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break;
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default:
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panic("bad thread state");
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/* NOTREACHED */
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}
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#endif
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}
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/*
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* Initialize type-stable parts of a thread (when newly created).
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*/
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static void
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thread_init(void *mem, int size)
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{
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struct thread *td;
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td = (struct thread *)mem;
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mtx_lock(&Giant);
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pmap_new_thread(td, 0);
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mtx_unlock(&Giant);
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cpu_thread_setup(td);
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td->td_sched = (struct td_sched *)&td[1];
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}
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/*
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* Tear down type-stable parts of a thread (just before being discarded).
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*/
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static void
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thread_fini(void *mem, int size)
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{
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struct thread *td;
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td = (struct thread *)mem;
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pmap_dispose_thread(td);
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}
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/*
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* Initialize type-stable parts of a kse (when newly created).
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*/
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static void
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kse_init(void *mem, int size)
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{
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struct kse *ke;
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ke = (struct kse *)mem;
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ke->ke_sched = (struct ke_sched *)&ke[1];
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}
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/*
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* Initialize type-stable parts of a ksegrp (when newly created).
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*/
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static void
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ksegrp_init(void *mem, int size)
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{
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struct ksegrp *kg;
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kg = (struct ksegrp *)mem;
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kg->kg_sched = (struct kg_sched *)&kg[1];
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}
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/*
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* KSE is linked onto the idle queue.
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*/
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void
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kse_link(struct kse *ke, struct ksegrp *kg)
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{
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struct proc *p = kg->kg_proc;
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TAILQ_INSERT_HEAD(&kg->kg_kseq, ke, ke_kglist);
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kg->kg_kses++;
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ke->ke_state = KES_UNQUEUED;
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ke->ke_proc = p;
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ke->ke_ksegrp = kg;
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ke->ke_owner = NULL;
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ke->ke_thread = NULL;
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ke->ke_oncpu = NOCPU;
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}
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void
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kse_unlink(struct kse *ke)
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{
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struct ksegrp *kg;
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mtx_assert(&sched_lock, MA_OWNED);
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kg = ke->ke_ksegrp;
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TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist);
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if (--kg->kg_kses == 0) {
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ksegrp_unlink(kg);
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}
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/*
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* Aggregate stats from the KSE
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*/
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kse_stash(ke);
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}
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void
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ksegrp_link(struct ksegrp *kg, struct proc *p)
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{
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TAILQ_INIT(&kg->kg_threads);
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TAILQ_INIT(&kg->kg_runq); /* links with td_runq */
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TAILQ_INIT(&kg->kg_slpq); /* links with td_runq */
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TAILQ_INIT(&kg->kg_kseq); /* all kses in ksegrp */
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TAILQ_INIT(&kg->kg_lq); /* loan kses in ksegrp */
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kg->kg_proc = p;
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/* the following counters are in the -zero- section and may not need clearing */
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kg->kg_numthreads = 0;
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kg->kg_runnable = 0;
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kg->kg_kses = 0;
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kg->kg_loan_kses = 0;
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kg->kg_runq_kses = 0; /* XXXKSE change name */
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/* link it in now that it's consistent */
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p->p_numksegrps++;
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TAILQ_INSERT_HEAD(&p->p_ksegrps, kg, kg_ksegrp);
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}
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void
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ksegrp_unlink(struct ksegrp *kg)
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{
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struct proc *p;
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mtx_assert(&sched_lock, MA_OWNED);
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p = kg->kg_proc;
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KASSERT(((kg->kg_numthreads == 0) && (kg->kg_kses == 0)),
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("kseg_unlink: residual threads or KSEs"));
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TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp);
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p->p_numksegrps--;
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/*
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* Aggregate stats from the KSE
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*/
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ksegrp_stash(kg);
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}
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/*
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* for a newly created process,
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* link up a the structure and its initial threads etc.
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*/
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void
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proc_linkup(struct proc *p, struct ksegrp *kg,
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struct kse *ke, struct thread *td)
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{
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TAILQ_INIT(&p->p_ksegrps); /* all ksegrps in proc */
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TAILQ_INIT(&p->p_threads); /* all threads in proc */
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TAILQ_INIT(&p->p_suspended); /* Threads suspended */
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p->p_numksegrps = 0;
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p->p_numthreads = 0;
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ksegrp_link(kg, p);
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kse_link(ke, kg);
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thread_link(td, kg);
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}
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int
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kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap)
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{
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struct proc *p;
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struct thread *td2;
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p = td->td_proc;
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/* KSE-enabled processes only, please. */
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if (!(p->p_flag & P_KSES))
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return (EINVAL);
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if (uap->tmbx == NULL)
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return (EINVAL);
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mtx_lock_spin(&sched_lock);
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FOREACH_THREAD_IN_PROC(p, td2) {
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if (td2->td_mailbox == uap->tmbx) {
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td2->td_flags |= TDF_INTERRUPT;
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if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR)) {
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if (td2->td_flags & TDF_CVWAITQ)
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cv_abort(td2);
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else
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abortsleep(td2);
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}
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mtx_unlock_spin(&sched_lock);
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td->td_retval[0] = 0;
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td->td_retval[1] = 0;
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return (0);
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}
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}
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mtx_unlock_spin(&sched_lock);
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return (ESRCH);
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}
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int
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kse_exit(struct thread *td, struct kse_exit_args *uap)
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{
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struct proc *p;
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struct ksegrp *kg;
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p = td->td_proc;
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/* Only UTS can do the syscall */
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if (!(p->p_flag & P_KSES) || (td->td_mailbox != NULL))
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return (EINVAL);
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kg = td->td_ksegrp;
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/* serialize killing kse */
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PROC_LOCK(p);
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mtx_lock_spin(&sched_lock);
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if ((kg->kg_kses == 1) && (kg->kg_numthreads > 1)) {
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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return (EDEADLK);
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}
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if ((p->p_numthreads == 1) && (p->p_numksegrps == 1)) {
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/* XXXSKE what if >1 KSE? check.... */
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p->p_flag &= ~P_KSES;
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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} else {
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td->td_kse->ke_flags |= KEF_EXIT;
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thread_exit();
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/* NOTREACHED */
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}
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return (0);
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}
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/*
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* Either becomes an upcall or waits for an awakening event and
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* THEN becomes an upcall. Only error cases return.
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*/
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int
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kse_release(struct thread * td, struct kse_release_args * uap)
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{
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struct proc *p;
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struct ksegrp *kg;
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p = td->td_proc;
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kg = td->td_ksegrp;
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/*
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* kse must have a mailbox ready for upcall, and only UTS can
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* do the syscall.
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*/
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if (!(p->p_flag & P_KSES) ||
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(td->td_mailbox != NULL) ||
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(td->td_kse->ke_mailbox == NULL))
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return (EINVAL);
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PROC_LOCK(p);
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/* Change OURSELF to become an upcall. */
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td->td_flags = TDF_UPCALLING; /* BOUND */
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if (kg->kg_completed == NULL) {
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/* XXXKSE also look for waiting signals etc. */
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/*
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* The KSE will however be lendable.
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*/
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mtx_lock_spin(&sched_lock);
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TD_SET_IDLE(td);
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PROC_UNLOCK(p);
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p->p_stats->p_ru.ru_nvcsw++;
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mi_switch();
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mtx_unlock_spin(&sched_lock);
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} else {
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PROC_UNLOCK(p);
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}
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return (0);
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}
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/* struct kse_wakeup_args {
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struct kse_mailbox *mbx;
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}; */
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int
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kse_wakeup(struct thread *td, struct kse_wakeup_args *uap)
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{
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struct proc *p;
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struct kse *ke;
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struct ksegrp *kg;
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struct thread *td2;
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p = td->td_proc;
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td2 = NULL;
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/* KSE-enabled processes only, please. */
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if (!(p->p_flag & P_KSES))
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return EINVAL;
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PROC_LOCK(p);
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if (uap->mbx) {
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FOREACH_KSEGRP_IN_PROC(p, kg) {
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FOREACH_KSE_IN_GROUP(kg, ke) {
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if (ke->ke_mailbox != uap->mbx)
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continue;
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td2 = ke->ke_owner ;
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KASSERT((td2 != NULL),("KSE with no owner"));
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if (!TD_IS_IDLE(td2)) {
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/* Return silently if no longer idle */
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PROC_UNLOCK(p);
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td->td_retval[0] = 0;
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td->td_retval[1] = 0;
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return (0);
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}
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break;
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}
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if (td2) {
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break;
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}
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}
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} else {
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/*
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* look for any idle KSE to resurrect.
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*/
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kg = td->td_ksegrp;
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mtx_lock_spin(&sched_lock);
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FOREACH_KSE_IN_GROUP(kg, ke) {
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td2 = ke->ke_owner;
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KASSERT((td2 != NULL),("KSE with no owner2"));
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if (TD_IS_IDLE(td2))
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break;
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}
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}
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if (td2) {
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mtx_lock_spin(&sched_lock);
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PROC_UNLOCK(p);
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TD_CLR_IDLE(td2);
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setrunnable(td2);
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mtx_unlock_spin(&sched_lock);
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td->td_retval[0] = 0;
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td->td_retval[1] = 0;
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return (0);
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}
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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return (ESRCH);
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}
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/*
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* No new KSEG: first call: use current KSE, don't schedule an upcall
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* All other situations, do allocate a new KSE and schedule an upcall on it.
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*/
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/* struct kse_create_args {
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struct kse_mailbox *mbx;
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int newgroup;
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}; */
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int
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kse_create(struct thread *td, struct kse_create_args *uap)
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{
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struct kse *newke;
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struct kse *ke;
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struct ksegrp *newkg;
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struct ksegrp *kg;
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struct proc *p;
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struct kse_mailbox mbx;
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int err;
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p = td->td_proc;
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if ((err = copyin(uap->mbx, &mbx, sizeof(mbx))))
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return (err);
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p->p_flag |= P_KSES; /* easier to just set it than to test and set */
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kg = td->td_ksegrp;
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if (uap->newgroup) {
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if (p->p_numksegrps >= max_groups_per_proc)
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return (EPROCLIM);
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/*
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* If we want a new KSEGRP it doesn't matter whether
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* we have already fired up KSE mode before or not.
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* We put the process in KSE mode and create a new KSEGRP
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* and KSE. If our KSE has not got a mailbox yet then
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* that doesn't matter, just leave it that way. It will
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* ensure that this thread stay BOUND. It's possible
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* that the call came form a threaded library and the main
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* program knows nothing of threads.
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*/
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newkg = ksegrp_alloc();
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bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp,
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kg_startzero, kg_endzero));
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bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
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RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy));
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newke = kse_alloc();
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} else {
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/*
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* Otherwise, if we have already set this KSE
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* to have a mailbox, we want to make another KSE here,
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* but only if there are not already the limit, which
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* is 1 per CPU max.
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*
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* If the current KSE doesn't have a mailbox we just use it
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* and give it one.
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*
|
|
* Because we don't like to access
|
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* the KSE outside of schedlock if we are UNBOUND,
|
|
* (because it can change if we are preempted by an interrupt)
|
|
* we can deduce it as having a mailbox if we are UNBOUND,
|
|
* and only need to actually look at it if we are BOUND,
|
|
* which is safe.
|
|
*/
|
|
if ((td->td_flags & TDF_UNBOUND) || td->td_kse->ke_mailbox) {
|
|
if (thread_debug == 0) { /* if debugging, allow more */
|
|
#ifdef SMP
|
|
if (kg->kg_kses > mp_ncpus)
|
|
#endif
|
|
return (EPROCLIM);
|
|
}
|
|
newke = kse_alloc();
|
|
} else {
|
|
newke = NULL;
|
|
}
|
|
newkg = NULL;
|
|
}
|
|
if (newke) {
|
|
bzero(&newke->ke_startzero, RANGEOF(struct kse,
|
|
ke_startzero, ke_endzero));
|
|
#if 0
|
|
bcopy(&ke->ke_startcopy, &newke->ke_startcopy,
|
|
RANGEOF(struct kse, ke_startcopy, ke_endcopy));
|
|
#endif
|
|
/* For the first call this may not have been set */
|
|
if (td->td_standin == NULL) {
|
|
td->td_standin = thread_alloc();
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
if (newkg) {
|
|
if (p->p_numksegrps >= max_groups_per_proc) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
ksegrp_free(newkg);
|
|
kse_free(newke);
|
|
return (EPROCLIM);
|
|
}
|
|
ksegrp_link(newkg, p);
|
|
}
|
|
else
|
|
newkg = kg;
|
|
kse_link(newke, newkg);
|
|
if (p->p_sflag & PS_NEEDSIGCHK)
|
|
newke->ke_flags |= KEF_ASTPENDING;
|
|
newke->ke_mailbox = uap->mbx;
|
|
newke->ke_upcall = mbx.km_func;
|
|
bcopy(&mbx.km_stack, &newke->ke_stack, sizeof(stack_t));
|
|
thread_schedule_upcall(td, newke);
|
|
mtx_unlock_spin(&sched_lock);
|
|
} else {
|
|
/*
|
|
* If we didn't allocate a new KSE then the we are using
|
|
* the exisiting (BOUND) kse.
|
|
*/
|
|
ke = td->td_kse;
|
|
ke->ke_mailbox = uap->mbx;
|
|
ke->ke_upcall = mbx.km_func;
|
|
bcopy(&mbx.km_stack, &ke->ke_stack, sizeof(stack_t));
|
|
}
|
|
/*
|
|
* Fill out the KSE-mode specific fields of the new kse.
|
|
*/
|
|
|
|
td->td_retval[0] = 0;
|
|
td->td_retval[1] = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Fill a ucontext_t with a thread's context information.
|
|
*
|
|
* This is an analogue to getcontext(3).
|
|
*/
|
|
void
|
|
thread_getcontext(struct thread *td, ucontext_t *uc)
|
|
{
|
|
|
|
/*
|
|
* XXX this is declared in a MD include file, i386/include/ucontext.h but
|
|
* is used in MI code.
|
|
*/
|
|
#ifdef __i386__
|
|
get_mcontext(td, &uc->uc_mcontext);
|
|
#endif
|
|
uc->uc_sigmask = td->td_proc->p_sigmask;
|
|
}
|
|
|
|
/*
|
|
* Set a thread's context from a ucontext_t.
|
|
*
|
|
* This is an analogue to setcontext(3).
|
|
*/
|
|
int
|
|
thread_setcontext(struct thread *td, ucontext_t *uc)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* XXX this is declared in a MD include file, i386/include/ucontext.h but
|
|
* is used in MI code.
|
|
*/
|
|
#ifdef __i386__
|
|
ret = set_mcontext(td, &uc->uc_mcontext);
|
|
#else
|
|
ret = ENOSYS;
|
|
#endif
|
|
if (ret == 0) {
|
|
SIG_CANTMASK(uc->uc_sigmask);
|
|
PROC_LOCK(td->td_proc);
|
|
td->td_proc->p_sigmask = uc->uc_sigmask;
|
|
PROC_UNLOCK(td->td_proc);
|
|
}
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Initialize global thread allocation resources.
|
|
*/
|
|
void
|
|
threadinit(void)
|
|
{
|
|
|
|
#ifndef __ia64__
|
|
thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
|
|
thread_ctor, thread_dtor, thread_init, thread_fini,
|
|
UMA_ALIGN_CACHE, 0);
|
|
#else
|
|
/*
|
|
* XXX the ia64 kstack allocator is really lame and is at the mercy
|
|
* of contigmallloc(). This hackery is to pre-construct a whole
|
|
* pile of thread structures with associated kernel stacks early
|
|
* in the system startup while contigmalloc() still works. Once we
|
|
* have them, keep them. Sigh.
|
|
*/
|
|
thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
|
|
thread_ctor, thread_dtor, thread_init, thread_fini,
|
|
UMA_ALIGN_CACHE, UMA_ZONE_NOFREE);
|
|
uma_prealloc(thread_zone, 512); /* XXX arbitary */
|
|
#endif
|
|
ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(),
|
|
NULL, NULL, ksegrp_init, NULL,
|
|
UMA_ALIGN_CACHE, 0);
|
|
kse_zone = uma_zcreate("KSE", sched_sizeof_kse(),
|
|
NULL, NULL, kse_init, NULL,
|
|
UMA_ALIGN_CACHE, 0);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra thread into the zombie thread queue.
|
|
*/
|
|
void
|
|
thread_stash(struct thread *td)
|
|
{
|
|
mtx_lock_spin(&zombie_thread_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_threads, td, td_runq);
|
|
mtx_unlock_spin(&zombie_thread_lock);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra kse into the zombie kse queue.
|
|
*/
|
|
void
|
|
kse_stash(struct kse *ke)
|
|
{
|
|
mtx_lock_spin(&zombie_thread_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_kses, ke, ke_procq);
|
|
mtx_unlock_spin(&zombie_thread_lock);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra ksegrp into the zombie ksegrp queue.
|
|
*/
|
|
void
|
|
ksegrp_stash(struct ksegrp *kg)
|
|
{
|
|
mtx_lock_spin(&zombie_thread_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_ksegrps, kg, kg_ksegrp);
|
|
mtx_unlock_spin(&zombie_thread_lock);
|
|
}
|
|
|
|
/*
|
|
* Reap zombie threads.
|
|
*/
|
|
void
|
|
thread_reap(void)
|
|
{
|
|
struct thread *td_first, *td_next;
|
|
struct kse *ke_first, *ke_next;
|
|
struct ksegrp *kg_first, * kg_next;
|
|
|
|
/*
|
|
* don't even bother to lock if none at this instant
|
|
* We really don't care about the next instant..
|
|
*/
|
|
if ((!TAILQ_EMPTY(&zombie_threads))
|
|
|| (!TAILQ_EMPTY(&zombie_kses))
|
|
|| (!TAILQ_EMPTY(&zombie_ksegrps))) {
|
|
mtx_lock_spin(&zombie_thread_lock);
|
|
td_first = TAILQ_FIRST(&zombie_threads);
|
|
ke_first = TAILQ_FIRST(&zombie_kses);
|
|
kg_first = TAILQ_FIRST(&zombie_ksegrps);
|
|
if (td_first)
|
|
TAILQ_INIT(&zombie_threads);
|
|
if (ke_first)
|
|
TAILQ_INIT(&zombie_kses);
|
|
if (kg_first)
|
|
TAILQ_INIT(&zombie_ksegrps);
|
|
mtx_unlock_spin(&zombie_thread_lock);
|
|
while (td_first) {
|
|
td_next = TAILQ_NEXT(td_first, td_runq);
|
|
thread_free(td_first);
|
|
td_first = td_next;
|
|
}
|
|
while (ke_first) {
|
|
ke_next = TAILQ_NEXT(ke_first, ke_procq);
|
|
kse_free(ke_first);
|
|
ke_first = ke_next;
|
|
}
|
|
while (kg_first) {
|
|
kg_next = TAILQ_NEXT(kg_first, kg_ksegrp);
|
|
ksegrp_free(kg_first);
|
|
kg_first = kg_next;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate a ksegrp.
|
|
*/
|
|
struct ksegrp *
|
|
ksegrp_alloc(void)
|
|
{
|
|
return (uma_zalloc(ksegrp_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Allocate a kse.
|
|
*/
|
|
struct kse *
|
|
kse_alloc(void)
|
|
{
|
|
return (uma_zalloc(kse_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Allocate a thread.
|
|
*/
|
|
struct thread *
|
|
thread_alloc(void)
|
|
{
|
|
thread_reap(); /* check if any zombies to get */
|
|
return (uma_zalloc(thread_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Deallocate a ksegrp.
|
|
*/
|
|
void
|
|
ksegrp_free(struct ksegrp *td)
|
|
{
|
|
uma_zfree(ksegrp_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Deallocate a kse.
|
|
*/
|
|
void
|
|
kse_free(struct kse *td)
|
|
{
|
|
uma_zfree(kse_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Deallocate a thread.
|
|
*/
|
|
void
|
|
thread_free(struct thread *td)
|
|
{
|
|
|
|
cpu_thread_clean(td);
|
|
uma_zfree(thread_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Store the thread context in the UTS's mailbox.
|
|
* then add the mailbox at the head of a list we are building in user space.
|
|
* The list is anchored in the ksegrp structure.
|
|
*/
|
|
int
|
|
thread_export_context(struct thread *td)
|
|
{
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
uintptr_t mbx;
|
|
void *addr;
|
|
int error;
|
|
ucontext_t uc;
|
|
uint temp;
|
|
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
|
|
/* Export the user/machine context. */
|
|
#if 0
|
|
addr = (caddr_t)td->td_mailbox +
|
|
offsetof(struct kse_thr_mailbox, tm_context);
|
|
#else /* if user pointer arithmetic is valid in the kernel */
|
|
addr = (void *)(&td->td_mailbox->tm_context);
|
|
#endif
|
|
error = copyin(addr, &uc, sizeof(ucontext_t));
|
|
if (error)
|
|
goto bad;
|
|
|
|
thread_getcontext(td, &uc);
|
|
error = copyout(&uc, addr, sizeof(ucontext_t));
|
|
if (error)
|
|
goto bad;
|
|
|
|
/* get address in latest mbox of list pointer */
|
|
#if 0
|
|
addr = (caddr_t)td->td_mailbox
|
|
+ offsetof(struct kse_thr_mailbox , tm_next);
|
|
#else /* if user pointer arithmetic is valid in the kernel */
|
|
addr = (void *)(&td->td_mailbox->tm_next);
|
|
#endif
|
|
/*
|
|
* Put the saved address of the previous first
|
|
* entry into this one
|
|
*/
|
|
for (;;) {
|
|
mbx = (uintptr_t)kg->kg_completed;
|
|
if (suword(addr, mbx)) {
|
|
error = EFAULT;
|
|
goto bad;
|
|
}
|
|
PROC_LOCK(p);
|
|
if (mbx == (uintptr_t)kg->kg_completed) {
|
|
kg->kg_completed = td->td_mailbox;
|
|
PROC_UNLOCK(p);
|
|
break;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
}
|
|
addr = (caddr_t)td->td_mailbox
|
|
+ offsetof(struct kse_thr_mailbox, tm_sticks);
|
|
temp = fuword(addr) + td->td_usticks;
|
|
if (suword(addr, temp))
|
|
goto bad;
|
|
return (0);
|
|
|
|
bad:
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Take the list of completed mailboxes for this KSEGRP and put them on this
|
|
* KSE's mailbox as it's the next one going up.
|
|
*/
|
|
static int
|
|
thread_link_mboxes(struct ksegrp *kg, struct kse *ke)
|
|
{
|
|
struct proc *p = kg->kg_proc;
|
|
void *addr;
|
|
uintptr_t mbx;
|
|
|
|
#if 0
|
|
addr = (caddr_t)ke->ke_mailbox
|
|
+ offsetof(struct kse_mailbox, km_completed);
|
|
#else /* if user pointer arithmetic is valid in the kernel */
|
|
addr = (void *)(&ke->ke_mailbox->km_completed);
|
|
#endif
|
|
for (;;) {
|
|
mbx = (uintptr_t)kg->kg_completed;
|
|
if (suword(addr, mbx)) {
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
return (EFAULT);
|
|
}
|
|
/* XXXKSE could use atomic CMPXCH here */
|
|
PROC_LOCK(p);
|
|
if (mbx == (uintptr_t)kg->kg_completed) {
|
|
kg->kg_completed = NULL;
|
|
PROC_UNLOCK(p);
|
|
break;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* This function should be called at statclock interrupt time
|
|
*/
|
|
int
|
|
thread_add_ticks_intr(int user, uint ticks)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct kse *ke = td->td_kse;
|
|
|
|
if (ke->ke_mailbox == NULL)
|
|
return -1;
|
|
if (user) {
|
|
/* Current always do via ast() */
|
|
ke->ke_flags |= KEF_ASTPENDING;
|
|
ke->ke_uuticks += ticks;
|
|
} else {
|
|
if (td->td_mailbox != NULL)
|
|
td->td_usticks += ticks;
|
|
else
|
|
ke->ke_usticks += ticks;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
thread_update_uticks(void)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct proc *p = td->td_proc;
|
|
struct kse *ke = td->td_kse;
|
|
struct kse_thr_mailbox *tmbx;
|
|
caddr_t addr;
|
|
uint uticks, sticks;
|
|
|
|
if (ke->ke_mailbox == NULL)
|
|
return 0;
|
|
|
|
uticks = ke->ke_uuticks;
|
|
ke->ke_uuticks = 0;
|
|
sticks = ke->ke_usticks;
|
|
ke->ke_usticks = 0;
|
|
#if 0
|
|
tmbx = (void *)fuword((caddr_t)ke->ke_mailbox
|
|
+ offsetof(struct kse_mailbox, km_curthread));
|
|
#else /* if user pointer arithmetic is ok in the kernel */
|
|
tmbx = (void *)fuword( (void *)&ke->ke_mailbox->km_curthread);
|
|
#endif
|
|
if ((tmbx == NULL) || (tmbx == (void *)-1))
|
|
return 0;
|
|
if (uticks) {
|
|
addr = (caddr_t)tmbx + offsetof(struct kse_thr_mailbox, tm_uticks);
|
|
uticks += fuword(addr);
|
|
if (suword(addr, uticks))
|
|
goto bad;
|
|
}
|
|
if (sticks) {
|
|
addr = (caddr_t)tmbx + offsetof(struct kse_thr_mailbox, tm_sticks);
|
|
sticks += fuword(addr);
|
|
if (suword(addr, sticks))
|
|
goto bad;
|
|
}
|
|
return 0;
|
|
bad:
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Discard the current thread and exit from its context.
|
|
*
|
|
* Because we can't free a thread while we're operating under its context,
|
|
* push the current thread into our CPU's deadthread holder. This means
|
|
* we needn't worry about someone else grabbing our context before we
|
|
* do a cpu_throw().
|
|
*/
|
|
void
|
|
thread_exit(void)
|
|
{
|
|
struct thread *td;
|
|
struct kse *ke;
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
|
|
td = curthread;
|
|
kg = td->td_ksegrp;
|
|
p = td->td_proc;
|
|
ke = td->td_kse;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT(p != NULL, ("thread exiting without a process"));
|
|
KASSERT(ke != NULL, ("thread exiting without a kse"));
|
|
KASSERT(kg != NULL, ("thread exiting without a kse group"));
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
CTR1(KTR_PROC, "thread_exit: thread %p", td);
|
|
KASSERT(!mtx_owned(&Giant), ("dying thread owns giant"));
|
|
|
|
if (td->td_standin != NULL) {
|
|
thread_stash(td->td_standin);
|
|
td->td_standin = NULL;
|
|
}
|
|
|
|
cpu_thread_exit(td); /* XXXSMP */
|
|
|
|
/*
|
|
* The last thread is left attached to the process
|
|
* So that the whole bundle gets recycled. Skip
|
|
* all this stuff.
|
|
*/
|
|
if (p->p_numthreads > 1) {
|
|
/*
|
|
* Unlink this thread from its proc and the kseg.
|
|
* In keeping with the other structs we probably should
|
|
* have a thread_unlink() that does some of this but it
|
|
* would only be called from here (I think) so it would
|
|
* be a waste. (might be useful for proc_fini() as well.)
|
|
*/
|
|
TAILQ_REMOVE(&p->p_threads, td, td_plist);
|
|
p->p_numthreads--;
|
|
TAILQ_REMOVE(&kg->kg_threads, td, td_kglist);
|
|
kg->kg_numthreads--;
|
|
/*
|
|
* The test below is NOT true if we are the
|
|
* sole exiting thread. P_STOPPED_SNGL is unset
|
|
* in exit1() after it is the only survivor.
|
|
*/
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
if (p->p_numthreads == p->p_suspcount) {
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
|
|
/* Reassign this thread's KSE. */
|
|
ke->ke_state = KES_UNQUEUED;
|
|
|
|
/*
|
|
* Decide what to do with the KSE attached to this thread.
|
|
* XXX Possibly kse_reassign should do both cases as it already
|
|
* does some of this.
|
|
*/
|
|
if (ke->ke_flags & KEF_EXIT) {
|
|
KASSERT((ke->ke_owner == td),
|
|
("thread_exit: KSE exiting with non-owner thread"));
|
|
ke->ke_thread = NULL;
|
|
td->td_kse = NULL;
|
|
kse_unlink(ke);
|
|
} else {
|
|
TD_SET_EXITING(td); /* definitly not runnable */
|
|
kse_reassign(ke);
|
|
}
|
|
PROC_UNLOCK(p);
|
|
td->td_state = TDS_INACTIVE;
|
|
td->td_proc = NULL;
|
|
td->td_ksegrp = NULL;
|
|
td->td_last_kse = NULL;
|
|
PCPU_SET(deadthread, td);
|
|
} else {
|
|
PROC_UNLOCK(p);
|
|
}
|
|
cpu_throw();
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* Do any thread specific cleanups that may be needed in wait()
|
|
* called with Giant held, proc and schedlock not held.
|
|
*/
|
|
void
|
|
thread_wait(struct proc *p)
|
|
{
|
|
struct thread *td;
|
|
|
|
KASSERT((p->p_numthreads == 1), ("Muliple threads in wait1()"));
|
|
KASSERT((p->p_numksegrps == 1), ("Muliple ksegrps in wait1()"));
|
|
FOREACH_THREAD_IN_PROC(p, td) {
|
|
if (td->td_standin != NULL) {
|
|
thread_free(td->td_standin);
|
|
td->td_standin = NULL;
|
|
}
|
|
cpu_thread_clean(td);
|
|
}
|
|
thread_reap(); /* check for zombie threads etc. */
|
|
}
|
|
|
|
/*
|
|
* Link a thread to a process.
|
|
* set up anything that needs to be initialized for it to
|
|
* be used by the process.
|
|
*
|
|
* Note that we do not link to the proc's ucred here.
|
|
* The thread is linked as if running but no KSE assigned.
|
|
*/
|
|
void
|
|
thread_link(struct thread *td, struct ksegrp *kg)
|
|
{
|
|
struct proc *p;
|
|
|
|
p = kg->kg_proc;
|
|
td->td_state = TDS_INACTIVE;
|
|
td->td_proc = p;
|
|
td->td_ksegrp = kg;
|
|
td->td_last_kse = NULL;
|
|
|
|
LIST_INIT(&td->td_contested);
|
|
callout_init(&td->td_slpcallout, 1);
|
|
TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist);
|
|
TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist);
|
|
p->p_numthreads++;
|
|
kg->kg_numthreads++;
|
|
td->td_kse = NULL;
|
|
}
|
|
|
|
void
|
|
kse_purge(struct proc *p, struct thread *td)
|
|
{
|
|
/* XXXKSE think about this..
|
|
may need to wake up threads on loan queue. */
|
|
struct ksegrp *kg;
|
|
|
|
KASSERT(p->p_numthreads == 1, ("bad thread number"));
|
|
mtx_lock_spin(&sched_lock);
|
|
while ((kg = TAILQ_FIRST(&p->p_ksegrps)) != NULL) {
|
|
TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp);
|
|
p->p_numksegrps--;
|
|
KASSERT(((kg->kg_kses == 0) && (kg != td->td_ksegrp)) ||
|
|
((kg->kg_kses == 1) && (kg == td->td_ksegrp)),
|
|
("wrong kg_kses"));
|
|
if (kg != td->td_ksegrp) {
|
|
ksegrp_stash(kg);
|
|
}
|
|
}
|
|
TAILQ_INSERT_HEAD(&p->p_ksegrps, td->td_ksegrp, kg_ksegrp);
|
|
p->p_numksegrps++;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
|
|
/*
|
|
* Create a thread and schedule it for upcall on the KSE given.
|
|
* Use our thread's standin so that we don't have to allocate one.
|
|
*/
|
|
struct thread *
|
|
thread_schedule_upcall(struct thread *td, struct kse *ke)
|
|
{
|
|
struct thread *td2;
|
|
int newkse;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
newkse = (ke != td->td_kse);
|
|
|
|
/*
|
|
* If the owner and kse are BOUND then that thread is planning to
|
|
* go to userland and upcalls are not expected. So don't make one.
|
|
* If it is not bound then make it so with the spare thread
|
|
* anf then borrw back the KSE to allow us to complete some in-kernel
|
|
* work. When we complete, the Bound thread will have the chance to
|
|
* complete. This thread will sleep as planned. Hopefully there will
|
|
* eventually be un unbound thread that can be converted to an
|
|
* upcall to report the completion of this thread.
|
|
*/
|
|
|
|
if ((td2 = td->td_standin) != NULL) {
|
|
td->td_standin = NULL;
|
|
} else {
|
|
if (newkse)
|
|
panic("no reserve thread when called with a new kse");
|
|
/*
|
|
* If called from (e.g.) sleep and we do not have
|
|
* a reserve thread, then we've used it, so do not
|
|
* create an upcall.
|
|
*/
|
|
return (NULL);
|
|
}
|
|
CTR3(KTR_PROC, "thread_schedule_upcall: thread %p (pid %d, %s)",
|
|
td2, td->td_proc->p_pid, td->td_proc->p_comm);
|
|
bzero(&td2->td_startzero,
|
|
(unsigned)RANGEOF(struct thread, td_startzero, td_endzero));
|
|
bcopy(&td->td_startcopy, &td2->td_startcopy,
|
|
(unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy));
|
|
thread_link(td2, ke->ke_ksegrp);
|
|
cpu_set_upcall(td2, td->td_pcb);
|
|
|
|
/*
|
|
* XXXKSE do we really need this? (default values for the
|
|
* frame).
|
|
*/
|
|
bcopy(td->td_frame, td2->td_frame, sizeof(struct trapframe));
|
|
|
|
/*
|
|
* Bind the new thread to the KSE,
|
|
* and if it's our KSE, lend it back to ourself
|
|
* so we can continue running.
|
|
*/
|
|
td2->td_ucred = crhold(td->td_ucred);
|
|
td2->td_flags = TDF_UPCALLING; /* note: BOUND */
|
|
td2->td_kse = ke;
|
|
td2->td_state = TDS_CAN_RUN;
|
|
td2->td_inhibitors = 0;
|
|
ke->ke_owner = td2;
|
|
/*
|
|
* If called from kse_reassign(), we are working on the current
|
|
* KSE so fake that we borrowed it. If called from
|
|
* kse_create(), don't, as we have a new kse too.
|
|
*/
|
|
if (!newkse) {
|
|
/*
|
|
* This thread will be scheduled when the current thread
|
|
* blocks, exits or tries to enter userspace, (which ever
|
|
* happens first). When that happens the KSe will "revert"
|
|
* to this thread in a BOUND manner. Since we are called
|
|
* from msleep() this is going to be "very soon" in nearly
|
|
* all cases.
|
|
*/
|
|
TD_SET_LOAN(td2);
|
|
} else {
|
|
ke->ke_thread = td2;
|
|
ke->ke_state = KES_THREAD;
|
|
setrunqueue(td2);
|
|
}
|
|
return (td2); /* bogus.. should be a void function */
|
|
}
|
|
|
|
/*
|
|
* Schedule an upcall to notify a KSE process recieved signals.
|
|
*
|
|
* XXX - Modifying a sigset_t like this is totally bogus.
|
|
*/
|
|
struct thread *
|
|
signal_upcall(struct proc *p, int sig)
|
|
{
|
|
struct thread *td, *td2;
|
|
struct kse *ke;
|
|
sigset_t ss;
|
|
int error;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
return (NULL);
|
|
|
|
td = FIRST_THREAD_IN_PROC(p);
|
|
ke = td->td_kse;
|
|
PROC_UNLOCK(p);
|
|
error = copyin(&ke->ke_mailbox->km_sigscaught, &ss, sizeof(sigset_t));
|
|
PROC_LOCK(p);
|
|
if (error)
|
|
return (NULL);
|
|
SIGADDSET(ss, sig);
|
|
PROC_UNLOCK(p);
|
|
error = copyout(&ss, &ke->ke_mailbox->km_sigscaught, sizeof(sigset_t));
|
|
PROC_LOCK(p);
|
|
if (error)
|
|
return (NULL);
|
|
if (td->td_standin == NULL)
|
|
td->td_standin = thread_alloc();
|
|
mtx_lock_spin(&sched_lock);
|
|
td2 = thread_schedule_upcall(td, ke); /* Bogus JRE */
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (td2);
|
|
}
|
|
|
|
/*
|
|
* setup done on the thread when it enters the kernel.
|
|
* XXXKSE Presently only for syscalls but eventually all kernel entries.
|
|
*/
|
|
void
|
|
thread_user_enter(struct proc *p, struct thread *td)
|
|
{
|
|
struct kse *ke;
|
|
|
|
/*
|
|
* First check that we shouldn't just abort.
|
|
* But check if we are the single thread first!
|
|
* XXX p_singlethread not locked, but should be safe.
|
|
*/
|
|
if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
thread_exit();
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* If we are doing a syscall in a KSE environment,
|
|
* note where our mailbox is. There is always the
|
|
* possibility that we could do this lazily (in kse_reassign()),
|
|
* but for now do it every time.
|
|
*/
|
|
ke = td->td_kse;
|
|
td->td_flags &= ~TDF_UNBOUND;
|
|
if (ke->ke_mailbox != NULL) {
|
|
#if 0
|
|
td->td_mailbox = (void *)fuword((caddr_t)ke->ke_mailbox
|
|
+ offsetof(struct kse_mailbox, km_curthread));
|
|
#else /* if user pointer arithmetic is ok in the kernel */
|
|
td->td_mailbox =
|
|
(void *)fuword( (void *)&ke->ke_mailbox->km_curthread);
|
|
#endif
|
|
if ((td->td_mailbox == NULL) ||
|
|
(td->td_mailbox == (void *)-1)) {
|
|
td->td_mailbox = NULL; /* single thread it.. */
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags &= ~(TDF_UNBOUND|TDF_CAN_UNBIND);
|
|
mtx_unlock_spin(&sched_lock);
|
|
} else {
|
|
/*
|
|
* when thread limit reached, act like that the thread
|
|
* has already done an upcall.
|
|
*/
|
|
if (p->p_numthreads > max_threads_per_proc) {
|
|
if (td->td_standin != NULL) {
|
|
thread_stash(td->td_standin);
|
|
td->td_standin = NULL;
|
|
}
|
|
} else {
|
|
if (td->td_standin == NULL)
|
|
td->td_standin = thread_alloc();
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags |= TDF_CAN_UNBIND;
|
|
mtx_unlock_spin(&sched_lock);
|
|
KASSERT((ke->ke_owner == td),
|
|
("thread_user_enter: No starting owner "));
|
|
ke->ke_owner = td;
|
|
td->td_usticks = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The extra work we go through if we are a threaded process when we
|
|
* return to userland.
|
|
*
|
|
* If we are a KSE process and returning to user mode, check for
|
|
* extra work to do before we return (e.g. for more syscalls
|
|
* to complete first). If we were in a critical section, we should
|
|
* just return to let it finish. Same if we were in the UTS (in
|
|
* which case the mailbox's context's busy indicator will be set).
|
|
* The only traps we suport will have set the mailbox.
|
|
* We will clear it here.
|
|
*/
|
|
int
|
|
thread_userret(struct thread *td, struct trapframe *frame)
|
|
{
|
|
int error;
|
|
int unbound;
|
|
struct kse *ke;
|
|
struct ksegrp *kg;
|
|
struct thread *worktodo;
|
|
struct proc *p;
|
|
struct timespec ts;
|
|
|
|
KASSERT((td->td_kse && td->td_kse->ke_thread && td->td_kse->ke_owner),
|
|
("thread_userret: bad thread/kse pointers"));
|
|
KASSERT((td == curthread),
|
|
("thread_userret: bad thread argument"));
|
|
|
|
|
|
kg = td->td_ksegrp;
|
|
p = td->td_proc;
|
|
error = 0;
|
|
unbound = TD_IS_UNBOUND(td);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if ((worktodo = kg->kg_last_assigned))
|
|
worktodo = TAILQ_NEXT(worktodo, td_runq);
|
|
else
|
|
worktodo = TAILQ_FIRST(&kg->kg_runq);
|
|
|
|
/*
|
|
* Permanently bound threads never upcall but they may
|
|
* loan out their KSE at this point.
|
|
* Upcalls imply bound.. They also may want to do some Philantropy.
|
|
* Temporarily bound threads on the other hand either yield
|
|
* to other work and transform into an upcall, or proceed back to
|
|
* userland.
|
|
*/
|
|
|
|
if (TD_CAN_UNBIND(td)) {
|
|
td->td_flags &= ~(TDF_UNBOUND|TDF_CAN_UNBIND);
|
|
if (!worktodo && (kg->kg_completed == NULL)) {
|
|
/*
|
|
* This thread has not started any upcall.
|
|
* If there is no work to report other than
|
|
* ourself, then it can return direct to userland.
|
|
*/
|
|
justreturn:
|
|
mtx_unlock_spin(&sched_lock);
|
|
thread_update_uticks();
|
|
td->td_mailbox = NULL;
|
|
return (0);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
error = thread_export_context(td);
|
|
td->td_usticks = 0;
|
|
if (error) {
|
|
/*
|
|
* As we are not running on a borrowed KSE,
|
|
* failing to do the KSE operation just defaults
|
|
* back to synchonous operation, so just return from
|
|
* the syscall.
|
|
*/
|
|
goto justreturn;
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
/*
|
|
* Turn ourself into a bound upcall.
|
|
* We will rely on kse_reassign()
|
|
* to make us run at a later time.
|
|
*/
|
|
td->td_flags |= TDF_UPCALLING;
|
|
|
|
/* there may be more work since we re-locked schedlock */
|
|
if ((worktodo = kg->kg_last_assigned))
|
|
worktodo = TAILQ_NEXT(worktodo, td_runq);
|
|
else
|
|
worktodo = TAILQ_FIRST(&kg->kg_runq);
|
|
} else if (unbound) {
|
|
/*
|
|
* We are an unbound thread, looking to
|
|
* return to user space. There must be another owner
|
|
* of this KSE.
|
|
* We are using a borrowed KSE. save state and exit.
|
|
* kse_reassign() will recycle the kse as needed,
|
|
*/
|
|
mtx_unlock_spin(&sched_lock);
|
|
error = thread_export_context(td);
|
|
td->td_usticks = 0;
|
|
if (error) {
|
|
/*
|
|
* There is nothing we can do.
|
|
* We just lose that context. We
|
|
* probably should note this somewhere and send
|
|
* the process a signal.
|
|
*/
|
|
PROC_LOCK(td->td_proc);
|
|
psignal(td->td_proc, SIGSEGV);
|
|
mtx_lock_spin(&sched_lock);
|
|
ke = td->td_kse;
|
|
/* possibly upcall with error? */
|
|
} else {
|
|
/*
|
|
* Don't make an upcall, just exit so that the owner
|
|
* can get its KSE if it wants it.
|
|
* Our context is already safely stored for later
|
|
* use by the UTS.
|
|
*/
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
ke = td->td_kse;
|
|
}
|
|
/*
|
|
* If the owner is idling, we now have something for it
|
|
* to report, so make it runnable.
|
|
* If the owner is not an upcall, make an attempt to
|
|
* ensure that at least one of any IDLED upcalls can
|
|
* wake up.
|
|
*/
|
|
if (ke->ke_owner->td_flags & TDF_UPCALLING) {
|
|
TD_CLR_IDLE(ke->ke_owner);
|
|
} else {
|
|
FOREACH_KSE_IN_GROUP(kg, ke) {
|
|
if (TD_IS_IDLE(ke->ke_owner)) {
|
|
TD_CLR_IDLE(ke->ke_owner);
|
|
}
|
|
}
|
|
}
|
|
thread_exit();
|
|
}
|
|
/*
|
|
* We ARE going back to userland with this KSE.
|
|
* We are permanently bound. We may be an upcall.
|
|
* If an upcall, check for threads that need to borrow the KSE.
|
|
* Any other thread that comes ready after this missed the boat.
|
|
*/
|
|
ke = td->td_kse;
|
|
|
|
/*
|
|
* If not upcalling, go back to userspace.
|
|
* If we are, get the upcall set up.
|
|
*/
|
|
if (td->td_flags & TDF_UPCALLING) {
|
|
if (worktodo) {
|
|
/*
|
|
* force a switch to more urgent 'in kernel'
|
|
* work. Control will return to this thread
|
|
* when there is no more work to do.
|
|
* kse_reassign() will do that for us.
|
|
*/
|
|
TD_SET_LOAN(td); /* XXXKSE may not be needed */
|
|
p->p_stats->p_ru.ru_nvcsw++;
|
|
mi_switch(); /* kse_reassign() will (re)find worktodo */
|
|
}
|
|
td->td_flags &= ~TDF_UPCALLING;
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
/*
|
|
* There is no more work to do and we are going to ride
|
|
* this thread/KSE up to userland as an upcall.
|
|
* Do the last parts of the setup needed for the upcall.
|
|
*/
|
|
CTR3(KTR_PROC, "userret: upcall thread %p (pid %d, %s)",
|
|
td, td->td_proc->p_pid, td->td_proc->p_comm);
|
|
|
|
/*
|
|
* Set user context to the UTS.
|
|
* Will use Giant in cpu_thread_clean() because it uses
|
|
* kmem_free(kernel_map, ...)
|
|
*/
|
|
cpu_set_upcall_kse(td, ke);
|
|
|
|
/*
|
|
* Unhook the list of completed threads.
|
|
* anything that completes after this gets to
|
|
* come in next time.
|
|
* Put the list of completed thread mailboxes on
|
|
* this KSE's mailbox.
|
|
*/
|
|
error = thread_link_mboxes(kg, ke);
|
|
if (error)
|
|
goto bad;
|
|
|
|
/*
|
|
* Set state and clear the thread mailbox pointer.
|
|
* From now on we are just a bound outgoing process.
|
|
* **Problem** userret is often called several times.
|
|
* it would be nice if this all happenned only on the first
|
|
* time through. (the scan for extra work etc.)
|
|
*/
|
|
#if 0
|
|
error = suword((caddr_t)ke->ke_mailbox +
|
|
offsetof(struct kse_mailbox, km_curthread), 0);
|
|
#else /* if user pointer arithmetic is ok in the kernel */
|
|
error = suword((caddr_t)&ke->ke_mailbox->km_curthread, 0);
|
|
#endif
|
|
ke->ke_uuticks = ke->ke_usticks = 0;
|
|
if (error)
|
|
goto bad;
|
|
nanotime(&ts);
|
|
if (copyout(&ts,
|
|
(caddr_t)&ke->ke_mailbox->km_timeofday, sizeof(ts))) {
|
|
goto bad;
|
|
}
|
|
} else {
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
/*
|
|
* Optimisation:
|
|
* Ensure that we have a spare thread available,
|
|
* for when we re-enter the kernel.
|
|
*/
|
|
if (td->td_standin == NULL) {
|
|
td->td_standin = thread_alloc();
|
|
}
|
|
|
|
thread_update_uticks();
|
|
td->td_mailbox = NULL;
|
|
return (0);
|
|
|
|
bad:
|
|
/*
|
|
* Things are going to be so screwed we should just kill the process.
|
|
* how do we do that?
|
|
*/
|
|
PROC_LOCK(td->td_proc);
|
|
psignal(td->td_proc, SIGSEGV);
|
|
PROC_UNLOCK(td->td_proc);
|
|
td->td_mailbox = NULL;
|
|
return (error); /* go sync */
|
|
}
|
|
|
|
/*
|
|
* Enforce single-threading.
|
|
*
|
|
* Returns 1 if the caller must abort (another thread is waiting to
|
|
* exit the process or similar). Process is locked!
|
|
* Returns 0 when you are successfully the only thread running.
|
|
* A process has successfully single threaded in the suspend mode when
|
|
* There are no threads in user mode. Threads in the kernel must be
|
|
* allowed to continue until they get to the user boundary. They may even
|
|
* copy out their return values and data before suspending. They may however be
|
|
* accellerated in reaching the user boundary as we will wake up
|
|
* any sleeping threads that are interruptable. (PCATCH).
|
|
*/
|
|
int
|
|
thread_single(int force_exit)
|
|
{
|
|
struct thread *td;
|
|
struct thread *td2;
|
|
struct proc *p;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
mtx_assert(&Giant, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
KASSERT((td != NULL), ("curthread is NULL"));
|
|
|
|
if ((p->p_flag & P_KSES) == 0)
|
|
return (0);
|
|
|
|
/* Is someone already single threading? */
|
|
if (p->p_singlethread)
|
|
return (1);
|
|
|
|
if (force_exit == SINGLE_EXIT) {
|
|
p->p_flag |= P_SINGLE_EXIT;
|
|
td->td_flags &= ~TDF_UNBOUND;
|
|
} else
|
|
p->p_flag &= ~P_SINGLE_EXIT;
|
|
p->p_flag |= P_STOPPED_SINGLE;
|
|
p->p_singlethread = td;
|
|
/* XXXKSE Which lock protects the below values? */
|
|
while ((p->p_numthreads - p->p_suspcount) != 1) {
|
|
mtx_lock_spin(&sched_lock);
|
|
FOREACH_THREAD_IN_PROC(p, td2) {
|
|
if (td2 == td)
|
|
continue;
|
|
if (TD_IS_INHIBITED(td2)) {
|
|
if (force_exit == SINGLE_EXIT) {
|
|
if (TD_IS_SUSPENDED(td2)) {
|
|
thread_unsuspend_one(td2);
|
|
}
|
|
if (TD_ON_SLEEPQ(td2) &&
|
|
(td2->td_flags & TDF_SINTR)) {
|
|
if (td2->td_flags & TDF_CVWAITQ)
|
|
cv_abort(td2);
|
|
else
|
|
abortsleep(td2);
|
|
}
|
|
if (TD_IS_IDLE(td2)) {
|
|
TD_CLR_IDLE(td2);
|
|
}
|
|
} else {
|
|
if (TD_IS_SUSPENDED(td2))
|
|
continue;
|
|
/* maybe other inhibitted states too? */
|
|
if (td2->td_inhibitors &
|
|
(TDI_SLEEPING | TDI_SWAPPED |
|
|
TDI_LOAN | TDI_IDLE |
|
|
TDI_EXITING))
|
|
thread_suspend_one(td2);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Maybe we suspended some threads.. was it enough?
|
|
*/
|
|
if ((p->p_numthreads - p->p_suspcount) == 1) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Wake us up when everyone else has suspended.
|
|
* In the mean time we suspend as well.
|
|
*/
|
|
thread_suspend_one(td);
|
|
mtx_unlock(&Giant);
|
|
PROC_UNLOCK(p);
|
|
p->p_stats->p_ru.ru_nvcsw++;
|
|
mi_switch();
|
|
mtx_unlock_spin(&sched_lock);
|
|
mtx_lock(&Giant);
|
|
PROC_LOCK(p);
|
|
}
|
|
if (force_exit == SINGLE_EXIT)
|
|
kse_purge(p, td);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Called in from locations that can safely check to see
|
|
* whether we have to suspend or at least throttle for a
|
|
* single-thread event (e.g. fork).
|
|
*
|
|
* Such locations include userret().
|
|
* If the "return_instead" argument is non zero, the thread must be able to
|
|
* accept 0 (caller may continue), or 1 (caller must abort) as a result.
|
|
*
|
|
* The 'return_instead' argument tells the function if it may do a
|
|
* thread_exit() or suspend, or whether the caller must abort and back
|
|
* out instead.
|
|
*
|
|
* If the thread that set the single_threading request has set the
|
|
* P_SINGLE_EXIT bit in the process flags then this call will never return
|
|
* if 'return_instead' is false, but will exit.
|
|
*
|
|
* P_SINGLE_EXIT | return_instead == 0| return_instead != 0
|
|
*---------------+--------------------+---------------------
|
|
* 0 | returns 0 | returns 0 or 1
|
|
* | when ST ends | immediatly
|
|
*---------------+--------------------+---------------------
|
|
* 1 | thread exits | returns 1
|
|
* | | immediatly
|
|
* 0 = thread_exit() or suspension ok,
|
|
* other = return error instead of stopping the thread.
|
|
*
|
|
* While a full suspension is under effect, even a single threading
|
|
* thread would be suspended if it made this call (but it shouldn't).
|
|
* This call should only be made from places where
|
|
* thread_exit() would be safe as that may be the outcome unless
|
|
* return_instead is set.
|
|
*/
|
|
int
|
|
thread_suspend_check(int return_instead)
|
|
{
|
|
struct thread *td;
|
|
struct proc *p;
|
|
struct kse *ke;
|
|
struct ksegrp *kg;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
while (P_SHOULDSTOP(p)) {
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
KASSERT(p->p_singlethread != NULL,
|
|
("singlethread not set"));
|
|
/*
|
|
* The only suspension in action is a
|
|
* single-threading. Single threader need not stop.
|
|
* XXX Should be safe to access unlocked
|
|
* as it can only be set to be true by us.
|
|
*/
|
|
if (p->p_singlethread == td)
|
|
return (0); /* Exempt from stopping. */
|
|
}
|
|
if (return_instead)
|
|
return (1);
|
|
|
|
/*
|
|
* If the process is waiting for us to exit,
|
|
* this thread should just suicide.
|
|
* Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE.
|
|
*/
|
|
if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
|
|
mtx_lock_spin(&sched_lock);
|
|
while (mtx_owned(&Giant))
|
|
mtx_unlock(&Giant);
|
|
/*
|
|
* All threads should be exiting
|
|
* Unless they are the active "singlethread".
|
|
* destroy un-needed KSEs as we go..
|
|
* KSEGRPS may implode too as #kses -> 0.
|
|
*/
|
|
ke = td->td_kse;
|
|
if (ke->ke_owner == td &&
|
|
(kg->kg_kses >= kg->kg_numthreads ))
|
|
ke->ke_flags |= KEF_EXIT;
|
|
thread_exit();
|
|
}
|
|
|
|
/*
|
|
* When a thread suspends, it just
|
|
* moves to the processes's suspend queue
|
|
* and stays there.
|
|
*
|
|
* XXXKSE if TDF_BOUND is true
|
|
* it will not release it's KSE which might
|
|
* lead to deadlock if there are not enough KSEs
|
|
* to complete all waiting threads.
|
|
* Maybe be able to 'lend' it out again.
|
|
* (lent kse's can not go back to userland?)
|
|
* and can only be lent in STOPPED state.
|
|
*/
|
|
mtx_lock_spin(&sched_lock);
|
|
if ((p->p_flag & P_STOPPED_SIG) &&
|
|
(p->p_suspcount+1 == p->p_numthreads)) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_LOCK(p->p_pptr);
|
|
if ((p->p_pptr->p_procsig->ps_flag &
|
|
PS_NOCLDSTOP) == 0) {
|
|
psignal(p->p_pptr, SIGCHLD);
|
|
}
|
|
PROC_UNLOCK(p->p_pptr);
|
|
mtx_lock_spin(&sched_lock);
|
|
}
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
thread_suspend_one(td);
|
|
PROC_UNLOCK(p);
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
if (p->p_numthreads == p->p_suspcount) {
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
p->p_stats->p_ru.ru_nivcsw++;
|
|
mi_switch();
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_LOCK(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
thread_suspend_one(struct thread *td)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
p->p_suspcount++;
|
|
TD_SET_SUSPENDED(td);
|
|
TAILQ_INSERT_TAIL(&p->p_suspended, td, td_runq);
|
|
/*
|
|
* Hack: If we are suspending but are on the sleep queue
|
|
* then we are in msleep or the cv equivalent. We
|
|
* want to look like we have two Inhibitors.
|
|
* May already be set.. doesn't matter.
|
|
*/
|
|
if (TD_ON_SLEEPQ(td))
|
|
TD_SET_SLEEPING(td);
|
|
}
|
|
|
|
void
|
|
thread_unsuspend_one(struct thread *td)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
TAILQ_REMOVE(&p->p_suspended, td, td_runq);
|
|
TD_CLR_SUSPENDED(td);
|
|
p->p_suspcount--;
|
|
setrunnable(td);
|
|
}
|
|
|
|
/*
|
|
* Allow all threads blocked by single threading to continue running.
|
|
*/
|
|
void
|
|
thread_unsuspend(struct proc *p)
|
|
{
|
|
struct thread *td;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
if (!P_SHOULDSTOP(p)) {
|
|
while (( td = TAILQ_FIRST(&p->p_suspended))) {
|
|
thread_unsuspend_one(td);
|
|
}
|
|
} else if ((P_SHOULDSTOP(p) == P_STOPPED_SINGLE) &&
|
|
(p->p_numthreads == p->p_suspcount)) {
|
|
/*
|
|
* Stopping everything also did the job for the single
|
|
* threading request. Now we've downgraded to single-threaded,
|
|
* let it continue.
|
|
*/
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
|
|
void
|
|
thread_single_end(void)
|
|
{
|
|
struct thread *td;
|
|
struct proc *p;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
p->p_flag &= ~P_STOPPED_SINGLE;
|
|
p->p_singlethread = NULL;
|
|
/*
|
|
* If there are other threads they mey now run,
|
|
* unless of course there is a blanket 'stop order'
|
|
* on the process. The single threader must be allowed
|
|
* to continue however as this is a bad place to stop.
|
|
*/
|
|
if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) {
|
|
mtx_lock_spin(&sched_lock);
|
|
while (( td = TAILQ_FIRST(&p->p_suspended))) {
|
|
thread_unsuspend_one(td);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
|