/* * Copyright (C) 2001 Julian Elischer . * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice(s), this list of conditions and the following disclaimer as * the first lines of this file unmodified other than the possible * addition of one or more copyright notices. * 2. Redistributions in binary form must reproduce the above copyright * notice(s), this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * KSEGRP related storage. */ static uma_zone_t upcall_zone; /* DEBUG ONLY */ extern int virtual_cpu; extern int thread_debug; extern int max_threads_per_proc; extern int max_groups_per_proc; extern int max_threads_hits; extern struct mtx kse_zombie_lock; #define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start)) TAILQ_HEAD(, kse_upcall) zombie_upcalls = TAILQ_HEAD_INITIALIZER(zombie_upcalls); static int thread_update_usr_ticks(struct thread *td, int user); static void thread_alloc_spare(struct thread *td, struct thread *spare); /* move to proc.h */ extern void kse_purge(struct proc *p, struct thread *td); extern void kse_purge_group(struct thread *td); void kseinit(void); void kse_GC(void); struct kse_upcall * upcall_alloc(void) { struct kse_upcall *ku; ku = uma_zalloc(upcall_zone, M_WAITOK); bzero(ku, sizeof(*ku)); return (ku); } void upcall_free(struct kse_upcall *ku) { uma_zfree(upcall_zone, ku); } void upcall_link(struct kse_upcall *ku, struct ksegrp *kg) { mtx_assert(&sched_lock, MA_OWNED); TAILQ_INSERT_TAIL(&kg->kg_upcalls, ku, ku_link); ku->ku_ksegrp = kg; kg->kg_numupcalls++; } void upcall_unlink(struct kse_upcall *ku) { struct ksegrp *kg = ku->ku_ksegrp; mtx_assert(&sched_lock, MA_OWNED); KASSERT(ku->ku_owner == NULL, ("%s: have owner", __func__)); TAILQ_REMOVE(&kg->kg_upcalls, ku, ku_link); kg->kg_numupcalls--; upcall_stash(ku); } void upcall_remove(struct thread *td) { if (td->td_upcall) { td->td_upcall->ku_owner = NULL; upcall_unlink(td->td_upcall); td->td_upcall = 0; } } #ifndef _SYS_SYSPROTO_H_ struct kse_switchin_args { const struct __mcontext *mcp; long val; long *loc; }; #endif int kse_switchin(struct thread *td, struct kse_switchin_args *uap) { mcontext_t mc; int error; error = (uap->mcp == NULL) ? EINVAL : 0; if (!error) error = copyin(uap->mcp, &mc, sizeof(mc)); if (!error && uap->loc != NULL) error = (suword(uap->loc, uap->val) != 0) ? EINVAL : 0; if (!error) error = set_mcontext(td, &mc); return ((error == 0) ? EJUSTRETURN : error); } /* struct kse_thr_interrupt_args { struct kse_thr_mailbox * tmbx; int cmd; long data; }; */ int kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap) { struct proc *p; struct thread *td2; p = td->td_proc; if (!(p->p_flag & P_SA)) return (EINVAL); switch (uap->cmd) { case KSE_INTR_SENDSIG: if (uap->data < 0 || uap->data > _SIG_MAXSIG) return (EINVAL); case KSE_INTR_INTERRUPT: case KSE_INTR_RESTART: PROC_LOCK(p); mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td2) { if (td2->td_mailbox == uap->tmbx) break; } if (td2 == NULL) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); return (ESRCH); } if (uap->cmd == KSE_INTR_SENDSIG) { if (uap->data > 0) { td2->td_flags &= ~TDF_INTERRUPT; mtx_unlock_spin(&sched_lock); tdsignal(td2, (int)uap->data, SIGTARGET_TD); } else { mtx_unlock_spin(&sched_lock); } } else { td2->td_flags |= TDF_INTERRUPT | TDF_ASTPENDING; if (TD_CAN_UNBIND(td2)) td2->td_upcall->ku_flags |= KUF_DOUPCALL; if (uap->cmd == KSE_INTR_INTERRUPT) td2->td_intrval = EINTR; else td2->td_intrval = ERESTART; if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR)) sleepq_abort(td2); mtx_unlock_spin(&sched_lock); } PROC_UNLOCK(p); break; case KSE_INTR_SIGEXIT: if (uap->data < 1 || uap->data > _SIG_MAXSIG) return (EINVAL); PROC_LOCK(p); sigexit(td, (int)uap->data); break; default: return (EINVAL); } return (0); } /* struct kse_exit_args { register_t dummy; }; */ int kse_exit(struct thread *td, struct kse_exit_args *uap) { struct proc *p; struct ksegrp *kg; struct kse *ke; struct kse_upcall *ku, *ku2; int error, count; p = td->td_proc; /* * Ensure that this is only called from the UTS */ if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td)) return (EINVAL); kg = td->td_ksegrp; count = 0; /* * Calculate the existing non-exiting upcalls in this ksegroup. * If we are the last upcall but there are still other threads, * then do not exit. We need the other threads to be able to * complete whatever they are doing. * XXX This relies on the userland knowing what to do if we return. * It may be a better choice to convert ourselves into a kse_release * ( or similar) and wait in the kernel to be needed. */ PROC_LOCK(p); mtx_lock_spin(&sched_lock); FOREACH_UPCALL_IN_GROUP(kg, ku2) { if (ku2->ku_flags & KUF_EXITING) count++; } if ((kg->kg_numupcalls - count) == 1 && (kg->kg_numthreads > 1)) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); return (EDEADLK); } ku->ku_flags |= KUF_EXITING; mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); /* * Mark the UTS mailbox as having been finished with. * If that fails then just go for a segfault. * XXX need to check it that can be deliverred without a mailbox. */ error = suword(&ku->ku_mailbox->km_flags, ku->ku_mflags|KMF_DONE); PROC_LOCK(p); if (error) psignal(p, SIGSEGV); mtx_lock_spin(&sched_lock); upcall_remove(td); ke = td->td_kse; if (p->p_numthreads == 1) { kse_purge(p, td); p->p_flag &= ~P_SA; mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); } else { if (kg->kg_numthreads == 1) { /* Shutdown a group */ kse_purge_group(td); ke->ke_flags |= KEF_EXIT; } thread_stopped(p); thread_exit(); /* NOTREACHED */ } return (0); } /* * Either becomes an upcall or waits for an awakening event and * then becomes an upcall. Only error cases return. */ /* struct kse_release_args { struct timespec *timeout; }; */ int kse_release(struct thread *td, struct kse_release_args *uap) { struct proc *p; struct ksegrp *kg; struct kse_upcall *ku; struct timespec timeout; struct timeval tv; sigset_t sigset; int error; p = td->td_proc; kg = td->td_ksegrp; if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td)) return (EINVAL); if (uap->timeout != NULL) { if ((error = copyin(uap->timeout, &timeout, sizeof(timeout)))) return (error); TIMESPEC_TO_TIMEVAL(&tv, &timeout); } if (td->td_pflags & TDP_SA) td->td_pflags |= TDP_UPCALLING; else { ku->ku_mflags = fuword(&ku->ku_mailbox->km_flags); if (ku->ku_mflags == -1) { PROC_LOCK(p); sigexit(td, SIGSEGV); } } PROC_LOCK(p); if (ku->ku_mflags & KMF_WAITSIGEVENT) { /* UTS wants to wait for signal event */ if (!(p->p_flag & P_SIGEVENT) && !(ku->ku_flags & KUF_DOUPCALL)) { td->td_kflags |= TDK_KSERELSIG; error = msleep(&p->p_siglist, &p->p_mtx, PPAUSE|PCATCH, "ksesigwait", (uap->timeout ? tvtohz(&tv) : 0)); td->td_kflags &= ~(TDK_KSERELSIG | TDK_WAKEUP); } p->p_flag &= ~P_SIGEVENT; sigset = p->p_siglist; PROC_UNLOCK(p); error = copyout(&sigset, &ku->ku_mailbox->km_sigscaught, sizeof(sigset)); } else { if (! kg->kg_completed && !(ku->ku_flags & KUF_DOUPCALL)) { kg->kg_upsleeps++; td->td_kflags |= TDK_KSEREL; error = msleep(&kg->kg_completed, &p->p_mtx, PPAUSE|PCATCH, "kserel", (uap->timeout ? tvtohz(&tv) : 0)); td->td_kflags &= ~(TDK_KSEREL | TDK_WAKEUP); kg->kg_upsleeps--; } PROC_UNLOCK(p); } if (ku->ku_flags & KUF_DOUPCALL) { mtx_lock_spin(&sched_lock); ku->ku_flags &= ~KUF_DOUPCALL; mtx_unlock_spin(&sched_lock); } return (0); } /* struct kse_wakeup_args { struct kse_mailbox *mbx; }; */ int kse_wakeup(struct thread *td, struct kse_wakeup_args *uap) { struct proc *p; struct ksegrp *kg; struct kse_upcall *ku; struct thread *td2; p = td->td_proc; td2 = NULL; ku = NULL; /* KSE-enabled processes only, please. */ if (!(p->p_flag & P_SA)) return (EINVAL); PROC_LOCK(p); mtx_lock_spin(&sched_lock); if (uap->mbx) { FOREACH_KSEGRP_IN_PROC(p, kg) { FOREACH_UPCALL_IN_GROUP(kg, ku) { if (ku->ku_mailbox == uap->mbx) break; } if (ku) break; } } else { kg = td->td_ksegrp; if (kg->kg_upsleeps) { mtx_unlock_spin(&sched_lock); wakeup_one(&kg->kg_completed); PROC_UNLOCK(p); return (0); } ku = TAILQ_FIRST(&kg->kg_upcalls); } if (ku == NULL) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); return (ESRCH); } if ((td2 = ku->ku_owner) == NULL) { mtx_unlock_spin(&sched_lock); panic("%s: no owner", __func__); } else if (td2->td_kflags & (TDK_KSEREL | TDK_KSERELSIG)) { mtx_unlock_spin(&sched_lock); if (!(td2->td_kflags & TDK_WAKEUP)) { td2->td_kflags |= TDK_WAKEUP; if (td2->td_kflags & TDK_KSEREL) sleepq_remove(td2, &kg->kg_completed); else sleepq_remove(td2, &p->p_siglist); } } else { ku->ku_flags |= KUF_DOUPCALL; mtx_unlock_spin(&sched_lock); } PROC_UNLOCK(p); return (0); } /* * No new KSEG: first call: use current KSE, don't schedule an upcall * All other situations, do allocate max new KSEs and schedule an upcall. */ /* struct kse_create_args { struct kse_mailbox *mbx; int newgroup; }; */ int kse_create(struct thread *td, struct kse_create_args *uap) { struct kse *newke; struct ksegrp *newkg; struct ksegrp *kg; struct proc *p; struct kse_mailbox mbx; struct kse_upcall *newku; int err, ncpus, sa = 0, first = 0; struct thread *newtd; p = td->td_proc; if ((err = copyin(uap->mbx, &mbx, sizeof(mbx)))) return (err); ncpus = mp_ncpus; if (virtual_cpu != 0) ncpus = virtual_cpu; if (!(mbx.km_flags & KMF_BOUND)) sa = TDP_SA; else ncpus = 1; PROC_LOCK(p); if (!(p->p_flag & P_SA)) { first = 1; p->p_flag |= P_SA; } PROC_UNLOCK(p); if (!sa && !uap->newgroup && !first) return (EINVAL); kg = td->td_ksegrp; if (uap->newgroup) { /* Have race condition but it is cheap */ if (p->p_numksegrps >= max_groups_per_proc) return (EPROCLIM); /* * If we want a new KSEGRP it doesn't matter whether * we have already fired up KSE mode before or not. * We put the process in KSE mode and create a new KSEGRP. */ newkg = ksegrp_alloc(); bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp, kg_startzero, kg_endzero)); bcopy(&kg->kg_startcopy, &newkg->kg_startcopy, RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy)); PROC_LOCK(p); mtx_lock_spin(&sched_lock); if (p->p_numksegrps >= max_groups_per_proc) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); ksegrp_free(newkg); return (EPROCLIM); } ksegrp_link(newkg, p); sched_fork_ksegrp(kg, newkg); mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); } else { if (!first && ((td->td_pflags & TDP_SA) ^ sa) != 0) return (EINVAL); newkg = kg; } /* * Creating upcalls more than number of physical cpu does * not help performance. */ if (newkg->kg_numupcalls >= ncpus) return (EPROCLIM); if (newkg->kg_numupcalls == 0) { /* * Initialize KSE group * * For multiplxed group, create KSEs as many as physical * cpus. This increases concurrent even if userland * is not MP safe and can only run on single CPU. * In ideal world, every physical cpu should execute a thread. * If there is enough KSEs, threads in kernel can be * executed parallel on different cpus with full speed, * Concurrent in kernel shouldn't be restricted by number of * upcalls userland provides. Adding more upcall structures * only increases concurrent in userland. * * For bound thread group, because there is only thread in the * group, we only create one KSE for the group. Thread in this * kind of group will never schedule an upcall when blocked, * this intends to simulate pthread system scope thread. */ while (newkg->kg_kses < ncpus) { newke = kse_alloc(); bzero(&newke->ke_startzero, RANGEOF(struct kse, ke_startzero, ke_endzero)); #if 0 mtx_lock_spin(&sched_lock); bcopy(&ke->ke_startcopy, &newke->ke_startcopy, RANGEOF(struct kse, ke_startcopy, ke_endcopy)); mtx_unlock_spin(&sched_lock); #endif mtx_lock_spin(&sched_lock); kse_link(newke, newkg); sched_fork_kse(td->td_kse, newke); /* Add engine */ kse_reassign(newke); mtx_unlock_spin(&sched_lock); } } newku = upcall_alloc(); newku->ku_mailbox = uap->mbx; newku->ku_func = mbx.km_func; bcopy(&mbx.km_stack, &newku->ku_stack, sizeof(stack_t)); /* For the first call this may not have been set */ if (td->td_standin == NULL) thread_alloc_spare(td, NULL); PROC_LOCK(p); if (newkg->kg_numupcalls >= ncpus) { PROC_UNLOCK(p); upcall_free(newku); return (EPROCLIM); } if (first && sa) { SIGSETOR(p->p_siglist, td->td_siglist); SIGEMPTYSET(td->td_siglist); SIGFILLSET(td->td_sigmask); SIG_CANTMASK(td->td_sigmask); } mtx_lock_spin(&sched_lock); PROC_UNLOCK(p); upcall_link(newku, newkg); if (mbx.km_quantum) newkg->kg_upquantum = max(1, mbx.km_quantum/tick); /* * Each upcall structure has an owner thread, find which * one owns it. */ if (uap->newgroup) { /* * Because new ksegrp hasn't thread, * create an initial upcall thread to own it. */ newtd = thread_schedule_upcall(td, newku); } else { /* * If current thread hasn't an upcall structure, * just assign the upcall to it. */ if (td->td_upcall == NULL) { newku->ku_owner = td; td->td_upcall = newku; newtd = td; } else { /* * Create a new upcall thread to own it. */ newtd = thread_schedule_upcall(td, newku); } } if (!sa) { newtd->td_mailbox = mbx.km_curthread; newtd->td_pflags &= ~TDP_SA; if (newtd != td) { mtx_unlock_spin(&sched_lock); cpu_set_upcall_kse(newtd, newku); mtx_lock_spin(&sched_lock); } } else { newtd->td_pflags |= TDP_SA; } if (newtd != td) setrunqueue(newtd); mtx_unlock_spin(&sched_lock); return (0); } /* * Initialize global thread allocation resources. */ void kseinit(void) { upcall_zone = uma_zcreate("UPCALL", sizeof(struct kse_upcall), NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); } /* * Stash an embarasingly extra upcall into the zombie upcall queue. */ void upcall_stash(struct kse_upcall *ku) { mtx_lock_spin(&kse_zombie_lock); TAILQ_INSERT_HEAD(&zombie_upcalls, ku, ku_link); mtx_unlock_spin(&kse_zombie_lock); } /* * Reap zombie kse resource. */ void kse_GC(void) { struct kse_upcall *ku_first, *ku_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_upcalls)) { mtx_lock_spin(&kse_zombie_lock); ku_first = TAILQ_FIRST(&zombie_upcalls); if (ku_first) TAILQ_INIT(&zombie_upcalls); mtx_unlock_spin(&kse_zombie_lock); while (ku_first) { ku_next = TAILQ_NEXT(ku_first, ku_link); upcall_free(ku_first); ku_first = ku_next; } } } /* * 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, int willexit) { struct proc *p; struct ksegrp *kg; uintptr_t mbx; void *addr; int error = 0, temp, sig; mcontext_t mc; p = td->td_proc; kg = td->td_ksegrp; /* Export the user/machine context. */ get_mcontext(td, &mc, 0); addr = (void *)(&td->td_mailbox->tm_context.uc_mcontext); error = copyout(&mc, addr, sizeof(mcontext_t)); if (error) goto bad; /* Exports clock ticks in kernel mode */ addr = (caddr_t)(&td->td_mailbox->tm_sticks); temp = fuword32(addr) + td->td_usticks; if (suword32(addr, temp)) { error = EFAULT; goto bad; } /* * Post sync signal, or process SIGKILL and SIGSTOP. * For sync signal, it is only possible when the signal is not * caught by userland or process is being debugged. */ PROC_LOCK(p); if (td->td_flags & TDF_NEEDSIGCHK) { mtx_lock_spin(&sched_lock); td->td_flags &= ~TDF_NEEDSIGCHK; mtx_unlock_spin(&sched_lock); mtx_lock(&p->p_sigacts->ps_mtx); while ((sig = cursig(td)) != 0) postsig(sig); mtx_unlock(&p->p_sigacts->ps_mtx); } if (willexit) SIGFILLSET(td->td_sigmask); PROC_UNLOCK(p); /* Get address in latest mbox of list pointer */ addr = (void *)(&td->td_mailbox->tm_next); /* * 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; /* * The thread context may be taken away by * other upcall threads when we unlock * process lock. it's no longer valid to * use it again in any other places. */ td->td_mailbox = NULL; PROC_UNLOCK(p); break; } PROC_UNLOCK(p); } td->td_usticks = 0; return (0); bad: PROC_LOCK(p); sigexit(td, SIGILL); return (error); } /* * Take the list of completed mailboxes for this KSEGRP and put them on this * upcall's mailbox as it's the next one going up. */ static int thread_link_mboxes(struct ksegrp *kg, struct kse_upcall *ku) { struct proc *p = kg->kg_proc; void *addr; uintptr_t mbx; addr = (void *)(&ku->ku_mailbox->km_completed); for (;;) { mbx = (uintptr_t)kg->kg_completed; if (suword(addr, mbx)) { PROC_LOCK(p); psignal(p, SIGSEGV); PROC_UNLOCK(p); return (EFAULT); } 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_statclock(int user) { struct thread *td = curthread; struct ksegrp *kg = td->td_ksegrp; if (kg->kg_numupcalls == 0 || !(td->td_pflags & TDP_SA)) return (0); if (user) { /* Current always do via ast() */ mtx_lock_spin(&sched_lock); td->td_flags |= (TDF_USTATCLOCK|TDF_ASTPENDING); mtx_unlock_spin(&sched_lock); td->td_uuticks++; } else { if (td->td_mailbox != NULL) td->td_usticks++; else { /* XXXKSE * We will call thread_user_enter() for every * kernel entry in future, so if the thread mailbox * is NULL, it must be a UTS kernel, don't account * clock ticks for it. */ } } return (0); } /* * Export state clock ticks for userland */ static int thread_update_usr_ticks(struct thread *td, int user) { struct proc *p = td->td_proc; struct kse_thr_mailbox *tmbx; struct kse_upcall *ku; struct ksegrp *kg; caddr_t addr; u_int uticks; if ((ku = td->td_upcall) == NULL) return (-1); tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread); if ((tmbx == NULL) || (tmbx == (void *)-1)) return (-1); if (user) { uticks = td->td_uuticks; td->td_uuticks = 0; addr = (caddr_t)&tmbx->tm_uticks; } else { uticks = td->td_usticks; td->td_usticks = 0; addr = (caddr_t)&tmbx->tm_sticks; } if (uticks) { if (suword32(addr, uticks+fuword32(addr))) { PROC_LOCK(p); psignal(p, SIGSEGV); PROC_UNLOCK(p); return (-2); } } kg = td->td_ksegrp; if (kg->kg_upquantum && ticks >= kg->kg_nextupcall) { mtx_lock_spin(&sched_lock); td->td_upcall->ku_flags |= KUF_DOUPCALL; mtx_unlock_spin(&sched_lock); } return (0); } /* * This function is intended to be used to initialize a spare thread * for upcall. Initialize thread's large data area outside sched_lock * for thread_schedule_upcall(). */ void thread_alloc_spare(struct thread *td, struct thread *spare) { if (td->td_standin) return; if (spare == NULL) { spare = thread_alloc(); spare->td_tid = thread_new_tid(); } td->td_standin = spare; bzero(&spare->td_startzero, (unsigned)RANGEOF(struct thread, td_startzero, td_endzero)); spare->td_proc = td->td_proc; spare->td_ucred = crhold(td->td_ucred); } /* * 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_upcall *ku) { struct thread *td2; mtx_assert(&sched_lock, MA_OWNED); /* * Schedule an upcall thread on specified kse_upcall, * the kse_upcall must be free. * td must have a spare thread. */ KASSERT(ku->ku_owner == NULL, ("%s: upcall has owner", __func__)); if ((td2 = td->td_standin) != NULL) { td->td_standin = NULL; } else { panic("no reserve thread when scheduling 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); bcopy(&td->td_startcopy, &td2->td_startcopy, (unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy)); thread_link(td2, ku->ku_ksegrp); /* inherit parts of blocked thread's context as a good template */ cpu_set_upcall(td2, td); /* Let the new thread become owner of the upcall */ ku->ku_owner = td2; td2->td_upcall = ku; td2->td_flags = 0; td2->td_pflags = TDP_SA|TDP_UPCALLING; td2->td_kse = NULL; td2->td_state = TDS_CAN_RUN; td2->td_inhibitors = 0; SIGFILLSET(td2->td_sigmask); SIG_CANTMASK(td2->td_sigmask); sched_fork_thread(td, td2); return (td2); /* bogus.. should be a void function */ } /* * It is only used when thread generated a trap and process is being * debugged. */ void thread_signal_add(struct thread *td, int sig) { struct proc *p; siginfo_t siginfo; struct sigacts *ps; int error; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); ps = p->p_sigacts; mtx_assert(&ps->ps_mtx, MA_OWNED); cpu_thread_siginfo(sig, 0, &siginfo); mtx_unlock(&ps->ps_mtx); PROC_UNLOCK(p); error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, sizeof(siginfo)); if (error) { PROC_LOCK(p); sigexit(td, SIGILL); } PROC_LOCK(p); SIGADDSET(td->td_sigmask, sig); mtx_lock(&ps->ps_mtx); } void thread_switchout(struct thread *td) { struct kse_upcall *ku; struct thread *td2; mtx_assert(&sched_lock, MA_OWNED); /* * If the outgoing thread is in threaded group and has never * scheduled an upcall, decide whether this is a short * or long term event and thus whether or not to schedule * an upcall. * If it is a short term event, just suspend it in * a way that takes its KSE with it. * Select the events for which we want to schedule upcalls. * For now it's just sleep. * XXXKSE eventually almost any inhibition could do. */ if (TD_CAN_UNBIND(td) && (td->td_standin) && TD_ON_SLEEPQ(td)) { /* * Release ownership of upcall, and schedule an upcall * thread, this new upcall thread becomes the owner of * the upcall structure. */ ku = td->td_upcall; ku->ku_owner = NULL; td->td_upcall = NULL; td->td_flags &= ~TDF_CAN_UNBIND; td2 = thread_schedule_upcall(td, ku); setrunqueue(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 ksegrp *kg; struct kse_upcall *ku; struct kse_thr_mailbox *tmbx; uint32_t tflags; kg = td->td_ksegrp; /* * First check that we shouldn't just abort. * But check if we are the single thread first! */ if (p->p_flag & P_SINGLE_EXIT) { PROC_LOCK(p); mtx_lock_spin(&sched_lock); thread_stopped(p); 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. */ kg = td->td_ksegrp; if (td->td_pflags & TDP_SA) { ku = td->td_upcall; KASSERT(ku, ("%s: no upcall owned", __func__)); KASSERT((ku->ku_owner == td), ("%s: wrong owner", __func__)); KASSERT(!TD_CAN_UNBIND(td), ("%s: can unbind", __func__)); ku->ku_mflags = fuword32((void *)&ku->ku_mailbox->km_flags); tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread); if ((tmbx == NULL) || (tmbx == (void *)-1L) || (ku->ku_mflags & KMF_NOUPCALL)) { td->td_mailbox = NULL; } else { if (td->td_standin == NULL) thread_alloc_spare(td, NULL); tflags = fuword32(&tmbx->tm_flags); /* * On some architectures, TP register points to thread * mailbox but not points to kse mailbox, and userland * can not atomically clear km_curthread, but can * use TP register, and set TMF_NOUPCALL in thread * flag to indicate a critical region. */ if (tflags & TMF_NOUPCALL) { td->td_mailbox = NULL; } else { td->td_mailbox = tmbx; mtx_lock_spin(&sched_lock); td->td_flags |= TDF_CAN_UNBIND; mtx_unlock_spin(&sched_lock); } } } } /* * 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 = 0, upcalls, uts_crit; struct kse_upcall *ku; struct ksegrp *kg, *kg2; struct proc *p; struct timespec ts; p = td->td_proc; kg = td->td_ksegrp; ku = td->td_upcall; /* Nothing to do with bound thread */ if (!(td->td_pflags & TDP_SA)) return (0); /* * Stat clock interrupt hit in userland, it * is returning from interrupt, charge thread's * userland time for UTS. */ if (td->td_flags & TDF_USTATCLOCK) { thread_update_usr_ticks(td, 1); mtx_lock_spin(&sched_lock); td->td_flags &= ~TDF_USTATCLOCK; mtx_unlock_spin(&sched_lock); if (kg->kg_completed || (td->td_upcall->ku_flags & KUF_DOUPCALL)) thread_user_enter(p, td); } uts_crit = (td->td_mailbox == NULL); /* * Optimisation: * This thread has not started any upcall. * If there is no work to report other than ourself, * then it can return direct to userland. */ if (TD_CAN_UNBIND(td)) { mtx_lock_spin(&sched_lock); td->td_flags &= ~TDF_CAN_UNBIND; if ((td->td_flags & TDF_NEEDSIGCHK) == 0 && (kg->kg_completed == NULL) && (ku->ku_flags & KUF_DOUPCALL) == 0 && (kg->kg_upquantum && ticks < kg->kg_nextupcall)) { mtx_unlock_spin(&sched_lock); thread_update_usr_ticks(td, 0); nanotime(&ts); error = copyout(&ts, (caddr_t)&ku->ku_mailbox->km_timeofday, sizeof(ts)); td->td_mailbox = 0; ku->ku_mflags = 0; if (error) goto out; return (0); } mtx_unlock_spin(&sched_lock); thread_export_context(td, 0); /* * There is something to report, and we own an upcall * strucuture, we can go to userland. * Turn ourself into an upcall thread. */ td->td_pflags |= TDP_UPCALLING; } else if (td->td_mailbox && (ku == NULL)) { thread_export_context(td, 1); PROC_LOCK(p); /* * There are upcall threads waiting for * work to do, wake one of them up. * XXXKSE Maybe wake all of them up. */ if (kg->kg_upsleeps) wakeup_one(&kg->kg_completed); mtx_lock_spin(&sched_lock); thread_stopped(p); thread_exit(); /* NOTREACHED */ } KASSERT(ku != NULL, ("upcall is NULL\n")); KASSERT(TD_CAN_UNBIND(td) == 0, ("can unbind")); if (p->p_numthreads > max_threads_per_proc) { max_threads_hits++; PROC_LOCK(p); mtx_lock_spin(&sched_lock); p->p_maxthrwaits++; while (p->p_numthreads > max_threads_per_proc) { upcalls = 0; FOREACH_KSEGRP_IN_PROC(p, kg2) { if (kg2->kg_numupcalls == 0) upcalls++; else upcalls += kg2->kg_numupcalls; } if (upcalls >= max_threads_per_proc) break; mtx_unlock_spin(&sched_lock); if (msleep(&p->p_numthreads, &p->p_mtx, PPAUSE|PCATCH, "maxthreads", 0)) { mtx_lock_spin(&sched_lock); break; } else { mtx_lock_spin(&sched_lock); } } p->p_maxthrwaits--; mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); } if (td->td_pflags & TDP_UPCALLING) { uts_crit = 0; kg->kg_nextupcall = ticks+kg->kg_upquantum; /* * There is no more work to do and we are going to ride * this thread 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); td->td_pflags &= ~TDP_UPCALLING; if (ku->ku_flags & KUF_DOUPCALL) { mtx_lock_spin(&sched_lock); ku->ku_flags &= ~KUF_DOUPCALL; mtx_unlock_spin(&sched_lock); } /* * Set user context to the UTS */ if (!(ku->ku_mflags & KMF_NOUPCALL)) { cpu_set_upcall_kse(td, ku); error = suword(&ku->ku_mailbox->km_curthread, 0); if (error) goto out; } /* * 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. */ if (!(ku->ku_mflags & KMF_NOCOMPLETED) && (error = thread_link_mboxes(kg, ku)) != 0) goto out; } if (!uts_crit) { nanotime(&ts); error = copyout(&ts, &ku->ku_mailbox->km_timeofday, sizeof(ts)); } out: if (error) { /* * 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); } else { /* * Optimisation: * Ensure that we have a spare thread available, * for when we re-enter the kernel. */ if (td->td_standin == NULL) thread_alloc_spare(td, NULL); } ku->ku_mflags = 0; /* * Clear thread mailbox first, then clear system tick count. * The order is important because thread_statclock() use * mailbox pointer to see if it is an userland thread or * an UTS kernel thread. */ td->td_mailbox = NULL; td->td_usticks = 0; return (error); /* go sync */ } int thread_upcall_check(struct thread *td) { PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); if (td->td_kflags & TDK_WAKEUP) return (1); else return (0); }