Index: head/sys/kern/kern_thr.c =================================================================== --- head/sys/kern/kern_thr.c (revision 336204) +++ head/sys/kern/kern_thr.c (revision 336205) @@ -1,623 +1,628 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2003, Jeffrey Roberson * 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 unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, 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 AUTHOR ``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 AUTHOR 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 "opt_posix.h" #include "opt_hwpmc_hooks.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include #endif #include #include static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation"); static int max_threads_per_proc = 1500; SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, &max_threads_per_proc, 0, "Limit on threads per proc"); static int max_threads_hits; SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count"); #ifdef COMPAT_FREEBSD32 static inline int suword_lwpid(void *addr, lwpid_t lwpid) { int error; if (SV_CURPROC_FLAG(SV_LP64)) error = suword(addr, lwpid); else error = suword32(addr, lwpid); return (error); } #else #define suword_lwpid suword #endif /* * System call interface. */ struct thr_create_initthr_args { ucontext_t ctx; long *tid; }; static int thr_create_initthr(struct thread *td, void *thunk) { struct thr_create_initthr_args *args; /* Copy out the child tid. */ args = thunk; if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid)) return (EFAULT); return (set_mcontext(td, &args->ctx.uc_mcontext)); } int sys_thr_create(struct thread *td, struct thr_create_args *uap) /* ucontext_t *ctx, long *id, int flags */ { struct thr_create_initthr_args args; int error; if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx)))) return (error); args.tid = uap->id; return (thread_create(td, NULL, thr_create_initthr, &args)); } int sys_thr_new(struct thread *td, struct thr_new_args *uap) /* struct thr_param * */ { struct thr_param param; int error; if (uap->param_size < 0 || uap->param_size > sizeof(param)) return (EINVAL); bzero(¶m, sizeof(param)); if ((error = copyin(uap->param, ¶m, uap->param_size))) return (error); return (kern_thr_new(td, ¶m)); } static int thr_new_initthr(struct thread *td, void *thunk) { stack_t stack; struct thr_param *param; /* * Here we copy out tid to two places, one for child and one * for parent, because pthread can create a detached thread, * if parent wants to safely access child tid, it has to provide * its storage, because child thread may exit quickly and * memory is freed before parent thread can access it. */ param = thunk; if ((param->child_tid != NULL && suword_lwpid(param->child_tid, td->td_tid)) || (param->parent_tid != NULL && suword_lwpid(param->parent_tid, td->td_tid))) return (EFAULT); /* Set up our machine context. */ stack.ss_sp = param->stack_base; stack.ss_size = param->stack_size; /* Set upcall address to user thread entry function. */ cpu_set_upcall(td, param->start_func, param->arg, &stack); /* Setup user TLS address and TLS pointer register. */ return (cpu_set_user_tls(td, param->tls_base)); } int kern_thr_new(struct thread *td, struct thr_param *param) { struct rtprio rtp, *rtpp; int error; rtpp = NULL; if (param->rtp != 0) { error = copyin(param->rtp, &rtp, sizeof(struct rtprio)); if (error) return (error); rtpp = &rtp; } return (thread_create(td, rtpp, thr_new_initthr, param)); } int thread_create(struct thread *td, struct rtprio *rtp, int (*initialize_thread)(struct thread *, void *), void *thunk) { struct thread *newtd; struct proc *p; int error; p = td->td_proc; if (rtp != NULL) { switch(rtp->type) { case RTP_PRIO_REALTIME: case RTP_PRIO_FIFO: /* Only root can set scheduler policy */ if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0) return (EPERM); if (rtp->prio > RTP_PRIO_MAX) return (EINVAL); break; case RTP_PRIO_NORMAL: rtp->prio = 0; break; default: return (EINVAL); } } #ifdef RACCT if (racct_enable) { PROC_LOCK(p); error = racct_add(p, RACCT_NTHR, 1); PROC_UNLOCK(p); if (error != 0) return (EPROCLIM); } #endif /* Initialize our td */ error = kern_thr_alloc(p, 0, &newtd); if (error) goto fail; cpu_copy_thread(newtd, td); bzero(&newtd->td_startzero, __rangeof(struct thread, td_startzero, td_endzero)); bcopy(&td->td_startcopy, &newtd->td_startcopy, __rangeof(struct thread, td_startcopy, td_endcopy)); newtd->td_proc = td->td_proc; newtd->td_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0; thread_cow_get(newtd, td); error = initialize_thread(newtd, thunk); if (error != 0) { thread_cow_free(newtd); thread_free(newtd); goto fail; } PROC_LOCK(p); p->p_flag |= P_HADTHREADS; thread_link(newtd, p); bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); thread_lock(td); /* let the scheduler know about these things. */ sched_fork_thread(td, newtd); thread_unlock(td); if (P_SHOULDSTOP(p)) newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; if (p->p_ptevents & PTRACE_LWP) newtd->td_dbgflags |= TDB_BORN; PROC_UNLOCK(p); #ifdef HWPMC_HOOKS if (PMC_PROC_IS_USING_PMCS(p)) PMC_CALL_HOOK(newtd, PMC_FN_THR_CREATE, NULL); else if (PMC_SYSTEM_SAMPLING_ACTIVE()) PMC_CALL_HOOK_UNLOCKED(newtd, PMC_FN_THR_CREATE_LOG, NULL); #endif tidhash_add(newtd); thread_lock(newtd); if (rtp != NULL) { if (!(td->td_pri_class == PRI_TIMESHARE && rtp->type == RTP_PRIO_NORMAL)) { rtp_to_pri(rtp, newtd); sched_prio(newtd, newtd->td_user_pri); } /* ignore timesharing class */ } TD_SET_CAN_RUN(newtd); sched_add(newtd, SRQ_BORING); thread_unlock(newtd); return (0); fail: #ifdef RACCT if (racct_enable) { PROC_LOCK(p); racct_sub(p, RACCT_NTHR, 1); PROC_UNLOCK(p); } #endif return (error); } int sys_thr_self(struct thread *td, struct thr_self_args *uap) /* long *id */ { int error; error = suword_lwpid(uap->id, (unsigned)td->td_tid); if (error == -1) return (EFAULT); return (0); } int sys_thr_exit(struct thread *td, struct thr_exit_args *uap) /* long *state */ { umtx_thread_exit(td); /* Signal userland that it can free the stack. */ if ((void *)uap->state != NULL) { suword_lwpid(uap->state, 1); kern_umtx_wake(td, uap->state, INT_MAX, 0); } return (kern_thr_exit(td)); } int kern_thr_exit(struct thread *td) { struct proc *p; p = td->td_proc; /* * If all of the threads in a process call this routine to * exit (e.g. all threads call pthread_exit()), exactly one * thread should return to the caller to terminate the process * instead of the thread. * * Checking p_numthreads alone is not sufficient since threads * might be committed to terminating while the PROC_LOCK is * dropped in either ptracestop() or while removing this thread * from the tidhash. Instead, the p_pendingexits field holds * the count of threads in either of those states and a thread * is considered the "last" thread if all of the other threads * in a process are already terminating. */ PROC_LOCK(p); if (p->p_numthreads == p->p_pendingexits + 1) { /* * Ignore attempts to shut down last thread in the * proc. This will actually call _exit(2) in the * usermode trampoline when it returns. */ PROC_UNLOCK(p); return (0); } p->p_pendingexits++; td->td_dbgflags |= TDB_EXIT; if (p->p_ptevents & PTRACE_LWP) ptracestop(td, SIGTRAP, NULL); PROC_UNLOCK(p); tidhash_remove(td); PROC_LOCK(p); p->p_pendingexits--; /* * The check above should prevent all other threads from this * process from exiting while the PROC_LOCK is dropped, so * there must be at least one other thread other than the * current thread. */ KASSERT(p->p_numthreads > 1, ("too few threads")); racct_sub(p, RACCT_NTHR, 1); tdsigcleanup(td); + +#ifdef AUDIT + AUDIT_SYSCALL_EXIT(0, td); +#endif + PROC_SLOCK(p); thread_stopped(p); thread_exit(); /* NOTREACHED */ } int sys_thr_kill(struct thread *td, struct thr_kill_args *uap) /* long id, int sig */ { ksiginfo_t ksi; struct thread *ttd; struct proc *p; int error; p = td->td_proc; ksiginfo_init(&ksi); ksi.ksi_signo = uap->sig; ksi.ksi_code = SI_LWP; ksi.ksi_pid = p->p_pid; ksi.ksi_uid = td->td_ucred->cr_ruid; if (uap->id == -1) { if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { error = EINVAL; } else { error = ESRCH; PROC_LOCK(p); FOREACH_THREAD_IN_PROC(p, ttd) { if (ttd != td) { error = 0; if (uap->sig == 0) break; tdksignal(ttd, uap->sig, &ksi); } } PROC_UNLOCK(p); } } else { error = 0; ttd = tdfind((lwpid_t)uap->id, p->p_pid); if (ttd == NULL) return (ESRCH); if (uap->sig == 0) ; else if (!_SIG_VALID(uap->sig)) error = EINVAL; else tdksignal(ttd, uap->sig, &ksi); PROC_UNLOCK(ttd->td_proc); } return (error); } int sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap) /* pid_t pid, long id, int sig */ { ksiginfo_t ksi; struct thread *ttd; struct proc *p; int error; AUDIT_ARG_SIGNUM(uap->sig); ksiginfo_init(&ksi); ksi.ksi_signo = uap->sig; ksi.ksi_code = SI_LWP; ksi.ksi_pid = td->td_proc->p_pid; ksi.ksi_uid = td->td_ucred->cr_ruid; if (uap->id == -1) { if ((p = pfind(uap->pid)) == NULL) return (ESRCH); AUDIT_ARG_PROCESS(p); error = p_cansignal(td, p, uap->sig); if (error) { PROC_UNLOCK(p); return (error); } if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { error = EINVAL; } else { error = ESRCH; FOREACH_THREAD_IN_PROC(p, ttd) { if (ttd != td) { error = 0; if (uap->sig == 0) break; tdksignal(ttd, uap->sig, &ksi); } } } PROC_UNLOCK(p); } else { ttd = tdfind((lwpid_t)uap->id, uap->pid); if (ttd == NULL) return (ESRCH); p = ttd->td_proc; AUDIT_ARG_PROCESS(p); error = p_cansignal(td, p, uap->sig); if (uap->sig == 0) ; else if (!_SIG_VALID(uap->sig)) error = EINVAL; else tdksignal(ttd, uap->sig, &ksi); PROC_UNLOCK(p); } return (error); } int sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap) /* const struct timespec *timeout */ { struct timespec ts, *tsp; int error; tsp = NULL; if (uap->timeout != NULL) { error = umtx_copyin_timeout(uap->timeout, &ts); if (error != 0) return (error); tsp = &ts; } return (kern_thr_suspend(td, tsp)); } int kern_thr_suspend(struct thread *td, struct timespec *tsp) { struct proc *p = td->td_proc; struct timeval tv; int error = 0; int timo = 0; if (td->td_pflags & TDP_WAKEUP) { td->td_pflags &= ~TDP_WAKEUP; return (0); } if (tsp != NULL) { if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) error = EWOULDBLOCK; else { TIMESPEC_TO_TIMEVAL(&tv, tsp); timo = tvtohz(&tv); } } PROC_LOCK(p); if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0) error = msleep((void *)td, &p->p_mtx, PCATCH, "lthr", timo); if (td->td_flags & TDF_THRWAKEUP) { thread_lock(td); td->td_flags &= ~TDF_THRWAKEUP; thread_unlock(td); PROC_UNLOCK(p); return (0); } PROC_UNLOCK(p); if (error == EWOULDBLOCK) error = ETIMEDOUT; else if (error == ERESTART) { if (timo != 0) error = EINTR; } return (error); } int sys_thr_wake(struct thread *td, struct thr_wake_args *uap) /* long id */ { struct proc *p; struct thread *ttd; if (uap->id == td->td_tid) { td->td_pflags |= TDP_WAKEUP; return (0); } p = td->td_proc; ttd = tdfind((lwpid_t)uap->id, p->p_pid); if (ttd == NULL) return (ESRCH); thread_lock(ttd); ttd->td_flags |= TDF_THRWAKEUP; thread_unlock(ttd); wakeup((void *)ttd); PROC_UNLOCK(p); return (0); } int sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap) { struct proc *p; char name[MAXCOMLEN + 1]; struct thread *ttd; int error; error = 0; name[0] = '\0'; if (uap->name != NULL) { error = copyinstr(uap->name, name, sizeof(name), NULL); if (error == ENAMETOOLONG) { error = copyin(uap->name, name, sizeof(name) - 1); name[sizeof(name) - 1] = '\0'; } if (error) return (error); } p = td->td_proc; ttd = tdfind((lwpid_t)uap->id, p->p_pid); if (ttd == NULL) return (ESRCH); strcpy(ttd->td_name, name); #ifdef HWPMC_HOOKS if (PMC_PROC_IS_USING_PMCS(p) || PMC_SYSTEM_SAMPLING_ACTIVE()) PMC_CALL_HOOK_UNLOCKED(ttd, PMC_FN_THR_CREATE_LOG, NULL); #endif #ifdef KTR sched_clear_tdname(ttd); #endif PROC_UNLOCK(p); return (error); } int kern_thr_alloc(struct proc *p, int pages, struct thread **ntd) { /* Have race condition but it is cheap. */ if (p->p_numthreads >= max_threads_per_proc) { ++max_threads_hits; return (EPROCLIM); } *ntd = thread_alloc(pages); if (*ntd == NULL) return (ENOMEM); return (0); } Index: head/sys/kern/kern_thread.c =================================================================== --- head/sys/kern/kern_thread.c (revision 336204) +++ head/sys/kern/kern_thread.c (revision 336205) @@ -1,1267 +1,1264 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * 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 "opt_witness.h" #include "opt_hwpmc_hooks.h" #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include #endif #include #include #include #include #include /* * Asserts below verify the stability of struct thread and struct proc * layout, as exposed by KBI to modules. On head, the KBI is allowed * to drift, change to the structures must be accompanied by the * assert update. * * On the stable branches after KBI freeze, conditions must not be * violated. Typically new fields are moved to the end of the * structures. */ #ifdef __amd64__ _Static_assert(offsetof(struct thread, td_flags) == 0xfc, "struct thread KBI td_flags"); _Static_assert(offsetof(struct thread, td_pflags) == 0x104, "struct thread KBI td_pflags"); _Static_assert(offsetof(struct thread, td_frame) == 0x470, "struct thread KBI td_frame"); _Static_assert(offsetof(struct thread, td_emuldata) == 0x518, "struct thread KBI td_emuldata"); _Static_assert(offsetof(struct proc, p_flag) == 0xb0, "struct proc KBI p_flag"); _Static_assert(offsetof(struct proc, p_pid) == 0xbc, "struct proc KBI p_pid"); _Static_assert(offsetof(struct proc, p_filemon) == 0x3d0, "struct proc KBI p_filemon"); _Static_assert(offsetof(struct proc, p_comm) == 0x3e4, "struct proc KBI p_comm"); _Static_assert(offsetof(struct proc, p_emuldata) == 0x4b8, "struct proc KBI p_emuldata"); #endif #ifdef __i386__ _Static_assert(offsetof(struct thread, td_flags) == 0x98, "struct thread KBI td_flags"); _Static_assert(offsetof(struct thread, td_pflags) == 0xa0, "struct thread KBI td_pflags"); _Static_assert(offsetof(struct thread, td_frame) == 0x2e8, "struct thread KBI td_frame"); _Static_assert(offsetof(struct thread, td_emuldata) == 0x334, "struct thread KBI td_emuldata"); _Static_assert(offsetof(struct proc, p_flag) == 0x68, "struct proc KBI p_flag"); _Static_assert(offsetof(struct proc, p_pid) == 0x74, "struct proc KBI p_pid"); _Static_assert(offsetof(struct proc, p_filemon) == 0x27c, "struct proc KBI p_filemon"); _Static_assert(offsetof(struct proc, p_comm) == 0x28c, "struct proc KBI p_comm"); _Static_assert(offsetof(struct proc, p_emuldata) == 0x318, "struct proc KBI p_emuldata"); #endif SDT_PROVIDER_DECLARE(proc); SDT_PROBE_DEFINE(proc, , , lwp__exit); /* * thread related storage. */ static uma_zone_t thread_zone; TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads); static struct mtx zombie_lock; MTX_SYSINIT(zombie_lock, &zombie_lock, "zombie lock", MTX_SPIN); static void thread_zombie(struct thread *); static int thread_unsuspend_one(struct thread *td, struct proc *p, bool boundary); #define TID_BUFFER_SIZE 1024 struct mtx tid_lock; static struct unrhdr *tid_unrhdr; static lwpid_t tid_buffer[TID_BUFFER_SIZE]; static int tid_head, tid_tail; static MALLOC_DEFINE(M_TIDHASH, "tidhash", "thread hash"); struct tidhashhead *tidhashtbl; u_long tidhash; struct rwlock tidhash_lock; EVENTHANDLER_LIST_DEFINE(thread_ctor); EVENTHANDLER_LIST_DEFINE(thread_dtor); EVENTHANDLER_LIST_DEFINE(thread_init); EVENTHANDLER_LIST_DEFINE(thread_fini); static lwpid_t tid_alloc(void) { lwpid_t tid; tid = alloc_unr(tid_unrhdr); if (tid != -1) return (tid); mtx_lock(&tid_lock); if (tid_head == tid_tail) { mtx_unlock(&tid_lock); return (-1); } tid = tid_buffer[tid_head]; tid_head = (tid_head + 1) % TID_BUFFER_SIZE; mtx_unlock(&tid_lock); return (tid); } static void tid_free(lwpid_t tid) { lwpid_t tmp_tid = -1; mtx_lock(&tid_lock); if ((tid_tail + 1) % TID_BUFFER_SIZE == tid_head) { tmp_tid = tid_buffer[tid_head]; tid_head = (tid_head + 1) % TID_BUFFER_SIZE; } tid_buffer[tid_tail] = tid; tid_tail = (tid_tail + 1) % TID_BUFFER_SIZE; mtx_unlock(&tid_lock); if (tmp_tid != -1) free_unr(tid_unrhdr, tmp_tid); } /* * Prepare a thread for use. */ static int thread_ctor(void *mem, int size, void *arg, int flags) { struct thread *td; td = (struct thread *)mem; td->td_state = TDS_INACTIVE; td->td_oncpu = NOCPU; td->td_tid = tid_alloc(); /* * Note that td_critnest begins life as 1 because the thread is not * running and is thereby implicitly waiting to be on the receiving * end of a context switch. */ td->td_critnest = 1; td->td_lend_user_pri = PRI_MAX; EVENTHANDLER_DIRECT_INVOKE(thread_ctor, td); #ifdef AUDIT audit_thread_alloc(td); #endif umtx_thread_alloc(td); return (0); } /* * Reclaim a thread after use. */ static void thread_dtor(void *mem, int size, void *arg) { struct thread *td; td = (struct thread *)mem; #ifdef INVARIANTS /* Verify that this thread is in a safe state to free. */ switch (td->td_state) { case TDS_INHIBITED: case TDS_RUNNING: case TDS_CAN_RUN: case TDS_RUNQ: /* * We must never unlink a thread that is in one of * these states, because it is currently active. */ panic("bad state for thread unlinking"); /* NOTREACHED */ case TDS_INACTIVE: break; default: panic("bad thread state"); /* NOTREACHED */ } #endif #ifdef AUDIT audit_thread_free(td); #endif /* Free all OSD associated to this thread. */ osd_thread_exit(td); td_softdep_cleanup(td); MPASS(td->td_su == NULL); EVENTHANDLER_DIRECT_INVOKE(thread_dtor, td); tid_free(td->td_tid); } /* * Initialize type-stable parts of a thread (when newly created). */ static int thread_init(void *mem, int size, int flags) { struct thread *td; td = (struct thread *)mem; td->td_sleepqueue = sleepq_alloc(); td->td_turnstile = turnstile_alloc(); td->td_rlqe = NULL; EVENTHANDLER_DIRECT_INVOKE(thread_init, td); umtx_thread_init(td); td->td_kstack = 0; td->td_sel = NULL; return (0); } /* * Tear down type-stable parts of a thread (just before being discarded). */ static void thread_fini(void *mem, int size) { struct thread *td; td = (struct thread *)mem; EVENTHANDLER_DIRECT_INVOKE(thread_fini, td); rlqentry_free(td->td_rlqe); turnstile_free(td->td_turnstile); sleepq_free(td->td_sleepqueue); umtx_thread_fini(td); seltdfini(td); } /* * For a newly created process, * link up all the structures and its initial threads etc. * called from: * {arch}/{arch}/machdep.c {arch}_init(), init386() etc. * proc_dtor() (should go away) * proc_init() */ void proc_linkup0(struct proc *p, struct thread *td) { TAILQ_INIT(&p->p_threads); /* all threads in proc */ proc_linkup(p, td); } void proc_linkup(struct proc *p, struct thread *td) { sigqueue_init(&p->p_sigqueue, p); p->p_ksi = ksiginfo_alloc(1); if (p->p_ksi != NULL) { /* XXX p_ksi may be null if ksiginfo zone is not ready */ p->p_ksi->ksi_flags = KSI_EXT | KSI_INS; } LIST_INIT(&p->p_mqnotifier); p->p_numthreads = 0; thread_link(td, p); } /* * Initialize global thread allocation resources. */ void threadinit(void) { mtx_init(&tid_lock, "TID lock", NULL, MTX_DEF); /* * pid_max cannot be greater than PID_MAX. * leave one number for thread0. */ tid_unrhdr = new_unrhdr(PID_MAX + 2, INT_MAX, &tid_lock); thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(), thread_ctor, thread_dtor, thread_init, thread_fini, 32 - 1, UMA_ZONE_NOFREE); tidhashtbl = hashinit(maxproc / 2, M_TIDHASH, &tidhash); rw_init(&tidhash_lock, "tidhash"); } /* * Place an unused thread on the zombie list. * Use the slpq as that must be unused by now. */ void thread_zombie(struct thread *td) { mtx_lock_spin(&zombie_lock); TAILQ_INSERT_HEAD(&zombie_threads, td, td_slpq); mtx_unlock_spin(&zombie_lock); } /* * Release a thread that has exited after cpu_throw(). */ void thread_stash(struct thread *td) { atomic_subtract_rel_int(&td->td_proc->p_exitthreads, 1); thread_zombie(td); } /* * Reap zombie resources. */ void thread_reap(void) { struct thread *td_first, *td_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)) { mtx_lock_spin(&zombie_lock); td_first = TAILQ_FIRST(&zombie_threads); if (td_first) TAILQ_INIT(&zombie_threads); mtx_unlock_spin(&zombie_lock); while (td_first) { td_next = TAILQ_NEXT(td_first, td_slpq); thread_cow_free(td_first); thread_free(td_first); td_first = td_next; } } } /* * Allocate a thread. */ struct thread * thread_alloc(int pages) { struct thread *td; thread_reap(); /* check if any zombies to get */ td = (struct thread *)uma_zalloc(thread_zone, M_WAITOK); KASSERT(td->td_kstack == 0, ("thread_alloc got thread with kstack")); if (!vm_thread_new(td, pages)) { uma_zfree(thread_zone, td); return (NULL); } cpu_thread_alloc(td); return (td); } int thread_alloc_stack(struct thread *td, int pages) { KASSERT(td->td_kstack == 0, ("thread_alloc_stack called on a thread with kstack")); if (!vm_thread_new(td, pages)) return (0); cpu_thread_alloc(td); return (1); } /* * Deallocate a thread. */ void thread_free(struct thread *td) { lock_profile_thread_exit(td); if (td->td_cpuset) cpuset_rel(td->td_cpuset); td->td_cpuset = NULL; cpu_thread_free(td); if (td->td_kstack != 0) vm_thread_dispose(td); callout_drain(&td->td_slpcallout); uma_zfree(thread_zone, td); } void thread_cow_get_proc(struct thread *newtd, struct proc *p) { PROC_LOCK_ASSERT(p, MA_OWNED); newtd->td_ucred = crhold(p->p_ucred); newtd->td_limit = lim_hold(p->p_limit); newtd->td_cowgen = p->p_cowgen; } void thread_cow_get(struct thread *newtd, struct thread *td) { newtd->td_ucred = crhold(td->td_ucred); newtd->td_limit = lim_hold(td->td_limit); newtd->td_cowgen = td->td_cowgen; } void thread_cow_free(struct thread *td) { if (td->td_ucred != NULL) crfree(td->td_ucred); if (td->td_limit != NULL) lim_free(td->td_limit); } void thread_cow_update(struct thread *td) { struct proc *p; struct ucred *oldcred; struct plimit *oldlimit; p = td->td_proc; oldcred = NULL; oldlimit = NULL; PROC_LOCK(p); if (td->td_ucred != p->p_ucred) { oldcred = td->td_ucred; td->td_ucred = crhold(p->p_ucred); } if (td->td_limit != p->p_limit) { oldlimit = td->td_limit; td->td_limit = lim_hold(p->p_limit); } td->td_cowgen = p->p_cowgen; PROC_UNLOCK(p); if (oldcred != NULL) crfree(oldcred); if (oldlimit != NULL) lim_free(oldlimit); } /* * Discard the current thread and exit from its context. * Always called with scheduler locked. * * 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) { uint64_t runtime, new_switchtime; struct thread *td; struct thread *td2; struct proc *p; int wakeup_swapper; td = curthread; p = td->td_proc; PROC_SLOCK_ASSERT(p, MA_OWNED); mtx_assert(&Giant, MA_NOTOWNED); PROC_LOCK_ASSERT(p, MA_OWNED); KASSERT(p != NULL, ("thread exiting without a process")); CTR3(KTR_PROC, "thread_exit: thread %p (pid %ld, %s)", td, (long)p->p_pid, td->td_name); SDT_PROBE0(proc, , , lwp__exit); KASSERT(TAILQ_EMPTY(&td->td_sigqueue.sq_list), ("signal pending")); -#ifdef AUDIT - AUDIT_SYSCALL_EXIT(0, td); -#endif /* * drop FPU & debug register state storage, or any other * architecture specific resources that * would not be on a new untouched process. */ cpu_thread_exit(td); /* * The last thread is left attached to the process * So that the whole bundle gets recycled. Skip * all this stuff if we never had threads. * EXIT clears all sign of other threads when * it goes to single threading, so the last thread always * takes the short path. */ if (p->p_flag & P_HADTHREADS) { if (p->p_numthreads > 1) { atomic_add_int(&td->td_proc->p_exitthreads, 1); thread_unlink(td); td2 = FIRST_THREAD_IN_PROC(p); sched_exit_thread(td2, td); /* * The test below is NOT true if we are the * sole exiting thread. P_STOPPED_SINGLE 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_lock(p->p_singlethread); wakeup_swapper = thread_unsuspend_one( p->p_singlethread, p, false); thread_unlock(p->p_singlethread); if (wakeup_swapper) kick_proc0(); } } PCPU_SET(deadthread, td); } else { /* * The last thread is exiting.. but not through exit() */ panic ("thread_exit: Last thread exiting on its own"); } } #ifdef HWPMC_HOOKS /* * If this thread is part of a process that is being tracked by hwpmc(4), * inform the module of the thread's impending exit. */ if (PMC_PROC_IS_USING_PMCS(td->td_proc)) { PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_EXIT, NULL); } else if (PMC_SYSTEM_SAMPLING_ACTIVE()) PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_EXIT_LOG, NULL); #endif PROC_UNLOCK(p); PROC_STATLOCK(p); thread_lock(td); PROC_SUNLOCK(p); /* Do the same timestamp bookkeeping that mi_switch() would do. */ new_switchtime = cpu_ticks(); runtime = new_switchtime - PCPU_GET(switchtime); td->td_runtime += runtime; td->td_incruntime += runtime; PCPU_SET(switchtime, new_switchtime); PCPU_SET(switchticks, ticks); VM_CNT_INC(v_swtch); /* Save our resource usage in our process. */ td->td_ru.ru_nvcsw++; ruxagg(p, td); rucollect(&p->p_ru, &td->td_ru); PROC_STATUNLOCK(p); td->td_state = TDS_INACTIVE; #ifdef WITNESS witness_thread_exit(td); #endif CTR1(KTR_PROC, "thread_exit: cpu_throw() thread %p", td); sched_throw(td); panic("I'm a teapot!"); /* NOTREACHED */ } /* * Do any thread specific cleanups that may be needed in wait() * called with Giant, proc and schedlock not held. */ void thread_wait(struct proc *p) { struct thread *td; mtx_assert(&Giant, MA_NOTOWNED); KASSERT(p->p_numthreads == 1, ("multiple threads in thread_wait()")); KASSERT(p->p_exitthreads == 0, ("p_exitthreads leaking")); td = FIRST_THREAD_IN_PROC(p); /* Lock the last thread so we spin until it exits cpu_throw(). */ thread_lock(td); thread_unlock(td); lock_profile_thread_exit(td); cpuset_rel(td->td_cpuset); td->td_cpuset = NULL; cpu_thread_clean(td); thread_cow_free(td); callout_drain(&td->td_slpcallout); 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. */ void thread_link(struct thread *td, struct proc *p) { /* * XXX This can't be enabled because it's called for proc0 before * its lock has been created. * PROC_LOCK_ASSERT(p, MA_OWNED); */ td->td_state = TDS_INACTIVE; td->td_proc = p; td->td_flags = TDF_INMEM; LIST_INIT(&td->td_contested); LIST_INIT(&td->td_lprof[0]); LIST_INIT(&td->td_lprof[1]); sigqueue_init(&td->td_sigqueue, p); callout_init(&td->td_slpcallout, 1); TAILQ_INSERT_TAIL(&p->p_threads, td, td_plist); p->p_numthreads++; } /* * Called from: * thread_exit() */ void thread_unlink(struct thread *td) { struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); TAILQ_REMOVE(&p->p_threads, td, td_plist); p->p_numthreads--; /* could clear a few other things here */ /* Must NOT clear links to proc! */ } static int calc_remaining(struct proc *p, int mode) { int remaining; PROC_LOCK_ASSERT(p, MA_OWNED); PROC_SLOCK_ASSERT(p, MA_OWNED); if (mode == SINGLE_EXIT) remaining = p->p_numthreads; else if (mode == SINGLE_BOUNDARY) remaining = p->p_numthreads - p->p_boundary_count; else if (mode == SINGLE_NO_EXIT || mode == SINGLE_ALLPROC) remaining = p->p_numthreads - p->p_suspcount; else panic("calc_remaining: wrong mode %d", mode); return (remaining); } static int remain_for_mode(int mode) { return (mode == SINGLE_ALLPROC ? 0 : 1); } static int weed_inhib(int mode, struct thread *td2, struct proc *p) { int wakeup_swapper; PROC_LOCK_ASSERT(p, MA_OWNED); PROC_SLOCK_ASSERT(p, MA_OWNED); THREAD_LOCK_ASSERT(td2, MA_OWNED); wakeup_swapper = 0; switch (mode) { case SINGLE_EXIT: if (TD_IS_SUSPENDED(td2)) wakeup_swapper |= thread_unsuspend_one(td2, p, true); if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0) wakeup_swapper |= sleepq_abort(td2, EINTR); break; case SINGLE_BOUNDARY: case SINGLE_NO_EXIT: if (TD_IS_SUSPENDED(td2) && (td2->td_flags & TDF_BOUNDARY) == 0) wakeup_swapper |= thread_unsuspend_one(td2, p, false); if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0) wakeup_swapper |= sleepq_abort(td2, ERESTART); break; case SINGLE_ALLPROC: /* * ALLPROC suspend tries to avoid spurious EINTR for * threads sleeping interruptable, by suspending the * thread directly, similarly to sig_suspend_threads(). * Since such sleep is not performed at the user * boundary, TDF_BOUNDARY flag is not set, and TDF_ALLPROCSUSP * is used to avoid immediate un-suspend. */ if (TD_IS_SUSPENDED(td2) && (td2->td_flags & (TDF_BOUNDARY | TDF_ALLPROCSUSP)) == 0) wakeup_swapper |= thread_unsuspend_one(td2, p, false); if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0) { if ((td2->td_flags & TDF_SBDRY) == 0) { thread_suspend_one(td2); td2->td_flags |= TDF_ALLPROCSUSP; } else { wakeup_swapper |= sleepq_abort(td2, ERESTART); } } break; } return (wakeup_swapper); } /* * 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 * accelerated in reaching the user boundary as we will wake up * any sleeping threads that are interruptable. (PCATCH). */ int thread_single(struct proc *p, int mode) { struct thread *td; struct thread *td2; int remaining, wakeup_swapper; td = curthread; KASSERT(mode == SINGLE_EXIT || mode == SINGLE_BOUNDARY || mode == SINGLE_ALLPROC || mode == SINGLE_NO_EXIT, ("invalid mode %d", mode)); /* * If allowing non-ALLPROC singlethreading for non-curproc * callers, calc_remaining() and remain_for_mode() should be * adjusted to also account for td->td_proc != p. For now * this is not implemented because it is not used. */ KASSERT((mode == SINGLE_ALLPROC && td->td_proc != p) || (mode != SINGLE_ALLPROC && td->td_proc == p), ("mode %d proc %p curproc %p", mode, p, td->td_proc)); mtx_assert(&Giant, MA_NOTOWNED); PROC_LOCK_ASSERT(p, MA_OWNED); if ((p->p_flag & P_HADTHREADS) == 0 && mode != SINGLE_ALLPROC) return (0); /* Is someone already single threading? */ if (p->p_singlethread != NULL && p->p_singlethread != td) return (1); if (mode == SINGLE_EXIT) { p->p_flag |= P_SINGLE_EXIT; p->p_flag &= ~P_SINGLE_BOUNDARY; } else { p->p_flag &= ~P_SINGLE_EXIT; if (mode == SINGLE_BOUNDARY) p->p_flag |= P_SINGLE_BOUNDARY; else p->p_flag &= ~P_SINGLE_BOUNDARY; } if (mode == SINGLE_ALLPROC) p->p_flag |= P_TOTAL_STOP; p->p_flag |= P_STOPPED_SINGLE; PROC_SLOCK(p); p->p_singlethread = td; remaining = calc_remaining(p, mode); while (remaining != remain_for_mode(mode)) { if (P_SHOULDSTOP(p) != P_STOPPED_SINGLE) goto stopme; wakeup_swapper = 0; FOREACH_THREAD_IN_PROC(p, td2) { if (td2 == td) continue; thread_lock(td2); td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; if (TD_IS_INHIBITED(td2)) { wakeup_swapper |= weed_inhib(mode, td2, p); #ifdef SMP } else if (TD_IS_RUNNING(td2) && td != td2) { forward_signal(td2); #endif } thread_unlock(td2); } if (wakeup_swapper) kick_proc0(); remaining = calc_remaining(p, mode); /* * Maybe we suspended some threads.. was it enough? */ if (remaining == remain_for_mode(mode)) break; stopme: /* * Wake us up when everyone else has suspended. * In the mean time we suspend as well. */ thread_suspend_switch(td, p); remaining = calc_remaining(p, mode); } if (mode == SINGLE_EXIT) { /* * Convert the process to an unthreaded process. The * SINGLE_EXIT is called by exit1() or execve(), in * both cases other threads must be retired. */ KASSERT(p->p_numthreads == 1, ("Unthreading with >1 threads")); p->p_singlethread = NULL; p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT | P_HADTHREADS); /* * Wait for any remaining threads to exit cpu_throw(). */ while (p->p_exitthreads != 0) { PROC_SUNLOCK(p); PROC_UNLOCK(p); sched_relinquish(td); PROC_LOCK(p); PROC_SLOCK(p); } } else if (mode == SINGLE_BOUNDARY) { /* * Wait until all suspended threads are removed from * the processors. The thread_suspend_check() * increments p_boundary_count while it is still * running, which makes it possible for the execve() * to destroy vmspace while our other threads are * still using the address space. * * We lock the thread, which is only allowed to * succeed after context switch code finished using * the address space. */ FOREACH_THREAD_IN_PROC(p, td2) { if (td2 == td) continue; thread_lock(td2); KASSERT((td2->td_flags & TDF_BOUNDARY) != 0, ("td %p not on boundary", td2)); KASSERT(TD_IS_SUSPENDED(td2), ("td %p is not suspended", td2)); thread_unlock(td2); } } PROC_SUNLOCK(p); return (0); } bool thread_suspend_check_needed(void) { struct proc *p; struct thread *td; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); return (P_SHOULDSTOP(p) || ((p->p_flag & P_TRACED) != 0 && (td->td_dbgflags & TDB_SUSPEND) != 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 | immediately *---------------+--------------------+--------------------- * 1 | thread exits | returns 1 * | | immediately * 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; int wakeup_swapper; td = curthread; p = td->td_proc; mtx_assert(&Giant, MA_NOTOWNED); PROC_LOCK_ASSERT(p, MA_OWNED); while (thread_suspend_check_needed()) { 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. * It is safe to access p->p_singlethread unlocked * because it can only be set to our address by us. */ if (p->p_singlethread == td) return (0); /* Exempt from stopping. */ } if ((p->p_flag & P_SINGLE_EXIT) && return_instead) return (EINTR); /* Should we goto user boundary if we didn't come from there? */ if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE && (p->p_flag & P_SINGLE_BOUNDARY) && return_instead) return (ERESTART); /* * Ignore suspend requests if they are deferred. */ if ((td->td_flags & TDF_SBDRY) != 0) { KASSERT(return_instead, ("TDF_SBDRY set for unsafe thread_suspend_check")); KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != (TDF_SEINTR | TDF_SERESTART), ("both TDF_SEINTR and TDF_SERESTART")); return (TD_SBDRY_INTR(td) ? TD_SBDRY_ERRNO(td) : 0); } /* * 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)) { PROC_UNLOCK(p); /* * Allow Linux emulation layer to do some work * before thread suicide. */ if (__predict_false(p->p_sysent->sv_thread_detach != NULL)) (p->p_sysent->sv_thread_detach)(td); umtx_thread_exit(td); kern_thr_exit(td); panic("stopped thread did not exit"); } PROC_SLOCK(p); thread_stopped(p); if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { if (p->p_numthreads == p->p_suspcount + 1) { thread_lock(p->p_singlethread); wakeup_swapper = thread_unsuspend_one( p->p_singlethread, p, false); thread_unlock(p->p_singlethread); if (wakeup_swapper) kick_proc0(); } } PROC_UNLOCK(p); thread_lock(td); /* * When a thread suspends, it just * gets taken off all queues. */ thread_suspend_one(td); if (return_instead == 0) { p->p_boundary_count++; td->td_flags |= TDF_BOUNDARY; } PROC_SUNLOCK(p); mi_switch(SW_INVOL | SWT_SUSPEND, NULL); thread_unlock(td); PROC_LOCK(p); } return (0); } void thread_suspend_switch(struct thread *td, struct proc *p) { KASSERT(!TD_IS_SUSPENDED(td), ("already suspended")); PROC_LOCK_ASSERT(p, MA_OWNED); PROC_SLOCK_ASSERT(p, MA_OWNED); /* * We implement thread_suspend_one in stages here to avoid * dropping the proc lock while the thread lock is owned. */ if (p == td->td_proc) { thread_stopped(p); p->p_suspcount++; } PROC_UNLOCK(p); thread_lock(td); td->td_flags &= ~TDF_NEEDSUSPCHK; TD_SET_SUSPENDED(td); sched_sleep(td, 0); PROC_SUNLOCK(p); DROP_GIANT(); mi_switch(SW_VOL | SWT_SUSPEND, NULL); thread_unlock(td); PICKUP_GIANT(); PROC_LOCK(p); PROC_SLOCK(p); } void thread_suspend_one(struct thread *td) { struct proc *p; p = td->td_proc; PROC_SLOCK_ASSERT(p, MA_OWNED); THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT(!TD_IS_SUSPENDED(td), ("already suspended")); p->p_suspcount++; td->td_flags &= ~TDF_NEEDSUSPCHK; TD_SET_SUSPENDED(td); sched_sleep(td, 0); } static int thread_unsuspend_one(struct thread *td, struct proc *p, bool boundary) { THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT(TD_IS_SUSPENDED(td), ("Thread not suspended")); TD_CLR_SUSPENDED(td); td->td_flags &= ~TDF_ALLPROCSUSP; if (td->td_proc == p) { PROC_SLOCK_ASSERT(p, MA_OWNED); p->p_suspcount--; if (boundary && (td->td_flags & TDF_BOUNDARY) != 0) { td->td_flags &= ~TDF_BOUNDARY; p->p_boundary_count--; } } return (setrunnable(td)); } /* * Allow all threads blocked by single threading to continue running. */ void thread_unsuspend(struct proc *p) { struct thread *td; int wakeup_swapper; PROC_LOCK_ASSERT(p, MA_OWNED); PROC_SLOCK_ASSERT(p, MA_OWNED); wakeup_swapper = 0; if (!P_SHOULDSTOP(p)) { FOREACH_THREAD_IN_PROC(p, td) { thread_lock(td); if (TD_IS_SUSPENDED(td)) { wakeup_swapper |= thread_unsuspend_one(td, p, true); } thread_unlock(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. */ if (p->p_singlethread->td_proc == p) { thread_lock(p->p_singlethread); wakeup_swapper = thread_unsuspend_one( p->p_singlethread, p, false); thread_unlock(p->p_singlethread); } } if (wakeup_swapper) kick_proc0(); } /* * End the single threading mode.. */ void thread_single_end(struct proc *p, int mode) { struct thread *td; int wakeup_swapper; KASSERT(mode == SINGLE_EXIT || mode == SINGLE_BOUNDARY || mode == SINGLE_ALLPROC || mode == SINGLE_NO_EXIT, ("invalid mode %d", mode)); PROC_LOCK_ASSERT(p, MA_OWNED); KASSERT((mode == SINGLE_ALLPROC && (p->p_flag & P_TOTAL_STOP) != 0) || (mode != SINGLE_ALLPROC && (p->p_flag & P_TOTAL_STOP) == 0), ("mode %d does not match P_TOTAL_STOP", mode)); KASSERT(mode == SINGLE_ALLPROC || p->p_singlethread == curthread, ("thread_single_end from other thread %p %p", curthread, p->p_singlethread)); KASSERT(mode != SINGLE_BOUNDARY || (p->p_flag & P_SINGLE_BOUNDARY) != 0, ("mis-matched SINGLE_BOUNDARY flags %x", p->p_flag)); p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT | P_SINGLE_BOUNDARY | P_TOTAL_STOP); PROC_SLOCK(p); p->p_singlethread = NULL; wakeup_swapper = 0; /* * If there are other threads they may 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 != remain_for_mode(mode) && !P_SHOULDSTOP(p)) { FOREACH_THREAD_IN_PROC(p, td) { thread_lock(td); if (TD_IS_SUSPENDED(td)) { wakeup_swapper |= thread_unsuspend_one(td, p, mode == SINGLE_BOUNDARY); } thread_unlock(td); } } KASSERT(mode != SINGLE_BOUNDARY || p->p_boundary_count == 0, ("inconsistent boundary count %d", p->p_boundary_count)); PROC_SUNLOCK(p); if (wakeup_swapper) kick_proc0(); } struct thread * thread_find(struct proc *p, lwpid_t tid) { struct thread *td; PROC_LOCK_ASSERT(p, MA_OWNED); FOREACH_THREAD_IN_PROC(p, td) { if (td->td_tid == tid) break; } return (td); } /* Locate a thread by number; return with proc lock held. */ struct thread * tdfind(lwpid_t tid, pid_t pid) { #define RUN_THRESH 16 struct thread *td; int run = 0; rw_rlock(&tidhash_lock); LIST_FOREACH(td, TIDHASH(tid), td_hash) { if (td->td_tid == tid) { if (pid != -1 && td->td_proc->p_pid != pid) { td = NULL; break; } PROC_LOCK(td->td_proc); if (td->td_proc->p_state == PRS_NEW) { PROC_UNLOCK(td->td_proc); td = NULL; break; } if (run > RUN_THRESH) { if (rw_try_upgrade(&tidhash_lock)) { LIST_REMOVE(td, td_hash); LIST_INSERT_HEAD(TIDHASH(td->td_tid), td, td_hash); rw_wunlock(&tidhash_lock); return (td); } } break; } run++; } rw_runlock(&tidhash_lock); return (td); } void tidhash_add(struct thread *td) { rw_wlock(&tidhash_lock); LIST_INSERT_HEAD(TIDHASH(td->td_tid), td, td_hash); rw_wunlock(&tidhash_lock); } void tidhash_remove(struct thread *td) { rw_wlock(&tidhash_lock); LIST_REMOVE(td, td_hash); rw_wunlock(&tidhash_lock); }