diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c index 3604d63531da..5e32aea1f56d 100644 --- a/sys/kern/kern_kthread.c +++ b/sys/kern/kern_kthread.c @@ -1,485 +1,511 @@ /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 1999 Peter Wemm * 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, 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Start a kernel process. This is called after a fork() call in * mi_startup() in the file kern/init_main.c. * * This function is used to start "internal" daemons and intended * to be called from SYSINIT(). */ void kproc_start(const void *udata) { const struct kproc_desc *kp = udata; int error; error = kproc_create((void (*)(void *))kp->func, NULL, kp->global_procpp, 0, 0, "%s", kp->arg0); if (error) panic("kproc_start: %s: error %d", kp->arg0, error); } /* * Create a kernel process/thread/whatever. It shares its address space * with proc0 - ie: kernel only. * * func is the function to start. * arg is the parameter to pass to function on first startup. * newpp is the return value pointing to the thread's struct proc. * flags are flags to fork1 (in unistd.h) * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.). */ -int -kproc_create(void (*func)(void *), void *arg, - struct proc **newpp, int flags, int pages, const char *fmt, ...) +static int +kproc_create1(void (*func)(void *), void *arg, + struct proc **newpp, int flags, int pages, const char *tdname) { struct fork_req fr; int error; - va_list ap; struct thread *td; struct proc *p2; if (!proc0.p_stats) panic("kproc_create called too soon"); bzero(&fr, sizeof(fr)); fr.fr_flags = RFMEM | RFFDG | RFPROC | RFSTOPPED | flags; fr.fr_flags2 = FR2_KPROC; fr.fr_pages = pages; fr.fr_procp = &p2; error = fork1(&thread0, &fr); if (error != 0) return (error); /* save a global descriptor, if desired */ if (newpp != NULL) *newpp = p2; /* set up arg0 for 'ps', et al */ - va_start(ap, fmt); - vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap); - va_end(ap); + strcpy(p2->p_comm, tdname); td = FIRST_THREAD_IN_PROC(p2); - va_start(ap, fmt); - vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap); - va_end(ap); + strcpy(td->td_name, tdname); #ifdef KTR sched_clear_tdname(td); #endif TSTHREAD(td, td->td_name); #ifdef HWPMC_HOOKS if (PMC_SYSTEM_SAMPLING_ACTIVE()) { PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_PROC_CREATE_LOG, p2); PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_CREATE_LOG, NULL); } #endif /* call the processes' main()... */ cpu_fork_kthread_handler(td, func, arg); /* Avoid inheriting affinity from a random parent. */ cpuset_kernthread(td); thread_lock(td); TD_SET_CAN_RUN(td); sched_prio(td, PVM); sched_user_prio(td, PUSER); /* Delay putting it on the run queue until now. */ if ((flags & RFSTOPPED) == 0) sched_add(td, SRQ_BORING); else thread_unlock(td); return (0); } +int +kproc_create(void (*func)(void *), void *arg, + struct proc **newpp, int flags, int pages, const char *fmt, ...) +{ + va_list ap; + int error; + char tdname[MAXCOMLEN + 1]; + + va_start(ap, fmt); + vsnprintf(tdname, sizeof(tdname), fmt, ap); + va_end(ap); + DROP_GIANT(); + error = kproc_create1(func, arg, newpp, flags, pages, tdname); + PICKUP_GIANT(); + return (error); +} + void kproc_exit(int ecode) { struct thread *td; struct proc *p; td = curthread; p = td->td_proc; /* * Reparent curthread from proc0 to init so that the zombie * is harvested. */ sx_xlock(&proctree_lock); PROC_LOCK(p); proc_reparent(p, initproc, true); PROC_UNLOCK(p); sx_xunlock(&proctree_lock); /* * Wakeup anyone waiting for us to exit. */ wakeup(p); /* Buh-bye! */ exit1(td, ecode, 0); } /* * Advise a kernel process to suspend (or resume) in its main loop. * Participation is voluntary. */ int kproc_suspend(struct proc *p, int timo) { /* * Make sure this is indeed a system process and we can safely * use the p_siglist field. */ PROC_LOCK(p); if ((p->p_flag & P_KPROC) == 0) { PROC_UNLOCK(p); return (EINVAL); } SIGADDSET(p->p_siglist, SIGSTOP); wakeup(p); return (msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkp", timo)); } int kproc_resume(struct proc *p) { /* * Make sure this is indeed a system process and we can safely * use the p_siglist field. */ PROC_LOCK(p); if ((p->p_flag & P_KPROC) == 0) { PROC_UNLOCK(p); return (EINVAL); } SIGDELSET(p->p_siglist, SIGSTOP); PROC_UNLOCK(p); wakeup(&p->p_siglist); return (0); } void kproc_suspend_check(struct proc *p) { PROC_LOCK(p); while (SIGISMEMBER(p->p_siglist, SIGSTOP)) { wakeup(&p->p_siglist); msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "kpsusp", 0); } PROC_UNLOCK(p); } /* * Start a kernel thread. * * This function is used to start "internal" daemons and intended * to be called from SYSINIT(). */ void kthread_start(const void *udata) { const struct kthread_desc *kp = udata; int error; error = kthread_add((void (*)(void *))kp->func, NULL, NULL, kp->global_threadpp, 0, 0, "%s", kp->arg0); if (error) panic("kthread_start: %s: error %d", kp->arg0, error); } /* * Create a kernel thread. It shares its address space * with proc0 - ie: kernel only. * * func is the function to start. * arg is the parameter to pass to function on first startup. * newtdp is the return value pointing to the thread's struct thread. * ** XXX fix this --> flags are flags to fork1 (in unistd.h) * fmt and following will be *printf'd into (*newtd)->td_name (for ps, etc.). */ -int -kthread_add(void (*func)(void *), void *arg, struct proc *p, - struct thread **newtdp, int flags, int pages, const char *fmt, ...) +static int +kthread_add1(void (*func)(void *), void *arg, struct proc *p, + struct thread **newtdp, int flags, int pages, const char *tdname) { - va_list ap; struct thread *newtd, *oldtd; if (!proc0.p_stats) panic("kthread_add called too soon"); /* If no process supplied, put it on proc0 */ if (p == NULL) p = &proc0; /* Initialize our new td */ newtd = thread_alloc(pages); if (newtd == NULL) return (ENOMEM); PROC_LOCK(p); oldtd = FIRST_THREAD_IN_PROC(p); bzero(&newtd->td_startzero, __rangeof(struct thread, td_startzero, td_endzero)); bcopy(&oldtd->td_startcopy, &newtd->td_startcopy, __rangeof(struct thread, td_startcopy, td_endcopy)); /* set up arg0 for 'ps', et al */ - va_start(ap, fmt); - vsnprintf(newtd->td_name, sizeof(newtd->td_name), fmt, ap); - va_end(ap); + strcpy(newtd->td_name, tdname); TSTHREAD(newtd, newtd->td_name); newtd->td_proc = p; /* needed for cpu_copy_thread */ newtd->td_pflags |= TDP_KTHREAD; /* might be further optimized for kthread */ cpu_copy_thread(newtd, oldtd); /* put the designated function(arg) as the resume context */ cpu_fork_kthread_handler(newtd, func, arg); thread_cow_get_proc(newtd, p); /* This code is similar to thread_create() in kern_thr.c. */ p->p_flag |= P_HADTHREADS; thread_link(newtd, p); thread_lock(oldtd); /* let the scheduler know about these things. */ sched_fork_thread(oldtd, newtd); TD_SET_CAN_RUN(newtd); thread_unlock(oldtd); PROC_UNLOCK(p); tidhash_add(newtd); /* Avoid inheriting affinity from a random parent. */ cpuset_kernthread(newtd); #ifdef HWPMC_HOOKS if (PMC_SYSTEM_SAMPLING_ACTIVE()) PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_CREATE_LOG, NULL); #endif /* Delay putting it on the run queue until now. */ if ((flags & RFSTOPPED) == 0) { thread_lock(newtd); sched_add(newtd, SRQ_BORING); } if (newtdp) *newtdp = newtd; return (0); } +int +kthread_add(void (*func)(void *), void *arg, struct proc *p, + struct thread **newtdp, int flags, int pages, const char *fmt, ...) +{ + va_list ap; + int error; + char tdname[MAXCOMLEN + 1]; + + va_start(ap, fmt); + vsnprintf(tdname, sizeof(tdname), fmt, ap); + va_end(ap); + DROP_GIANT(); + error = kthread_add1(func, arg, p, newtdp, flags, pages, tdname); + PICKUP_GIANT(); + return (error); +} + void kthread_exit(void) { struct proc *p; struct thread *td; td = curthread; p = td->td_proc; #ifdef HWPMC_HOOKS if (PMC_SYSTEM_SAMPLING_ACTIVE()) PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_THR_EXIT_LOG, NULL); #endif /* A module may be waiting for us to exit. */ wakeup(td); /* * The last exiting thread in a kernel process must tear down * the whole process. */ PROC_LOCK(p); if (p->p_numthreads == 1) { PROC_UNLOCK(p); kproc_exit(0); } if (p->p_sysent->sv_ontdexit != NULL) p->p_sysent->sv_ontdexit(td); tidhash_remove(td); umtx_thread_exit(td); tdsigcleanup(td); PROC_SLOCK(p); thread_exit(); } /* * Advise a kernel process to suspend (or resume) in its main loop. * Participation is voluntary. */ int kthread_suspend(struct thread *td, int timo) { struct proc *p; p = td->td_proc; /* * td_pflags should not be read by any thread other than * curthread, but as long as this flag is invariant during the * thread's lifetime, it is OK to check its state. */ if ((td->td_pflags & TDP_KTHREAD) == 0) return (EINVAL); /* * The caller of the primitive should have already checked that the * thread is up and running, thus not being blocked by other * conditions. */ PROC_LOCK(p); thread_lock(td); td->td_flags |= TDF_KTH_SUSP; thread_unlock(td); return (msleep(&td->td_flags, &p->p_mtx, PPAUSE | PDROP, "suspkt", timo)); } /* * Resume a thread previously put asleep with kthread_suspend(). */ int kthread_resume(struct thread *td) { struct proc *p; p = td->td_proc; /* * td_pflags should not be read by any thread other than * curthread, but as long as this flag is invariant during the * thread's lifetime, it is OK to check its state. */ if ((td->td_pflags & TDP_KTHREAD) == 0) return (EINVAL); PROC_LOCK(p); thread_lock(td); td->td_flags &= ~TDF_KTH_SUSP; thread_unlock(td); wakeup(&td->td_flags); PROC_UNLOCK(p); return (0); } /* * Used by the thread to poll as to whether it should yield/sleep * and notify the caller that is has happened. */ void kthread_suspend_check(void) { struct proc *p; struct thread *td; td = curthread; p = td->td_proc; if ((td->td_pflags & TDP_KTHREAD) == 0) panic("%s: curthread is not a valid kthread", __func__); /* * Setting the TDF_KTH_SUSP flag is protected by process lock. * * Do an unlocked read first to avoid serializing with all other threads * in the common case of not suspending. */ if ((td->td_flags & TDF_KTH_SUSP) == 0) return; PROC_LOCK(p); while ((td->td_flags & TDF_KTH_SUSP) != 0) { wakeup(&td->td_flags); msleep(&td->td_flags, &p->p_mtx, PPAUSE, "ktsusp", 0); } PROC_UNLOCK(p); } int kproc_kthread_add(void (*func)(void *), void *arg, struct proc **procptr, struct thread **tdptr, int flags, int pages, const char *procname, const char *fmt, ...) { int error; va_list ap; char buf[100]; struct thread *td; if (*procptr == NULL) { error = kproc_create(func, arg, procptr, flags, pages, "%s", procname); if (error) return (error); td = FIRST_THREAD_IN_PROC(*procptr); if (tdptr) *tdptr = td; va_start(ap, fmt); vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap); va_end(ap); #ifdef KTR sched_clear_tdname(td); #endif return (0); } va_start(ap, fmt); vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); error = kthread_add(func, arg, *procptr, tdptr, flags, pages, "%s", buf); return (error); }