int linux_fork(struct thread *td, struct linux_fork_args *args) { int error; struct proc *p2; struct thread *td2; #ifdef DEBUG if (ldebug(fork)) printf(ARGS(fork, "")); #endif if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0)) != 0) return (error); td->td_retval[0] = p2->p_pid; td->td_retval[1] = 0; error = linux_proc_init(td, td->td_retval[0], 0); if (error) return (error); td2 = FIRST_THREAD_IN_PROC(p2); /* * Make this runnable after we are finished with it. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); return (0); }
int linux_fork(struct thread *td, struct linux_fork_args *args) { struct fork_req fr; int error; struct proc *p2; struct thread *td2; #ifdef DEBUG if (ldebug(fork)) printf(ARGS(fork, "")); #endif bzero(&fr, sizeof(fr)); fr.fr_flags = RFFDG | RFPROC | RFSTOPPED; fr.fr_procp = &p2; if ((error = fork1(td, &fr)) != 0) return (error); td2 = FIRST_THREAD_IN_PROC(p2); linux_proc_init(td, td2, 0); td->td_retval[0] = p2->p_pid; /* * Make this runnable after we are finished with it. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); return (0); }
/* * Select the KSE that will be run next. From that find the thread, and * remove it from the KSEGRP's run queue. If there is thread clustering, * this will be what does it. */ struct thread * choosethread(void) { struct kse *ke; struct thread *td; struct ksegrp *kg; #if defined(SMP) && (defined(__i386__) || defined(__amd64__)) if (smp_active == 0 && PCPU_GET(cpuid) != 0) { /* Shutting down, run idlethread on AP's */ td = PCPU_GET(idlethread); ke = td->td_kse; CTR1(KTR_RUNQ, "choosethread: td=%p (idle)", td); ke->ke_flags |= KEF_DIDRUN; TD_SET_RUNNING(td); return (td); } #endif retry: ke = sched_choose(); if (ke) { td = ke->ke_thread; KASSERT((td->td_kse == ke), ("kse/thread mismatch")); kg = ke->ke_ksegrp; if (td->td_proc->p_flag & P_HADTHREADS) { if (kg->kg_last_assigned == td) { kg->kg_last_assigned = TAILQ_PREV(td, threadqueue, td_runq); } TAILQ_REMOVE(&kg->kg_runq, td, td_runq); kg->kg_runnable--; } CTR2(KTR_RUNQ, "choosethread: td=%p pri=%d", td, td->td_priority); } else { /* Simulate runq_choose() having returned the idle thread */ td = PCPU_GET(idlethread); ke = td->td_kse; CTR1(KTR_RUNQ, "choosethread: td=%p (idle)", td); } ke->ke_flags |= KEF_DIDRUN; /* * If we are in panic, only allow system threads, * plus the one we are running in, to be run. */ if (panicstr && ((td->td_proc->p_flag & P_SYSTEM) == 0 && (td->td_flags & TDF_INPANIC) == 0)) { /* note that it is no longer on the run queue */ TD_SET_CAN_RUN(td); goto retry; } TD_SET_RUNNING(td); return (td); }
int linux_vfork(struct thread *td, struct linux_vfork_args *args) { int error; struct proc *p2; struct thread *td2; #ifdef DEBUG if (ldebug(vfork)) printf(ARGS(vfork, "")); #endif /* Exclude RFPPWAIT */ if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2, NULL, 0)) != 0) return (error); td->td_retval[0] = p2->p_pid; error = linux_proc_init(td, td->td_retval[0], 0); if (error) return (error); PROC_LOCK(p2); p2->p_flag |= P_PPWAIT; PROC_UNLOCK(p2); td2 = FIRST_THREAD_IN_PROC(p2); /* * Make this runnable after we are finished with it. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); /* wait for the children to exit, ie. emulate vfork */ PROC_LOCK(p2); while (p2->p_flag & P_PPWAIT) cv_wait(&p2->p_pwait, &p2->p_mtx); PROC_UNLOCK(p2); return (0); }
/* * Remove a thread from its KSEGRP's run queue. * This in turn may remove it from a KSE if it was already assigned * to one, possibly causing a new thread to be assigned to the KSE * and the KSE getting a new priority. */ static void remrunqueue(struct thread *td) { struct thread *td2, *td3; struct ksegrp *kg; struct kse *ke; mtx_assert(&sched_lock, MA_OWNED); KASSERT((TD_ON_RUNQ(td)), ("remrunqueue: Bad state on run queue")); kg = td->td_ksegrp; ke = td->td_kse; CTR1(KTR_RUNQ, "remrunqueue: td%p", td); TD_SET_CAN_RUN(td); /* * If it is not a threaded process, take the shortcut. */ if ((td->td_proc->p_flag & P_HADTHREADS) == 0) { /* remve from sys run queue and free up a slot */ sched_rem(td); ke->ke_state = KES_THREAD; return; } td3 = TAILQ_PREV(td, threadqueue, td_runq); TAILQ_REMOVE(&kg->kg_runq, td, td_runq); kg->kg_runnable--; if (ke->ke_state == KES_ONRUNQ) { /* * This thread has been assigned to the system run queue. * We need to dissociate it and try assign the * KSE to the next available thread. Then, we should * see if we need to move the KSE in the run queues. */ sched_rem(td); ke->ke_state = KES_THREAD; td2 = kg->kg_last_assigned; KASSERT((td2 != NULL), ("last assigned has wrong value")); if (td2 == td) kg->kg_last_assigned = td3; /* slot_fill(kg); */ /* will replace it with another */ } }
/* * Change the priority of a thread that is on the run queue. */ void adjustrunqueue( struct thread *td, int newpri) { struct ksegrp *kg; struct kse *ke; mtx_assert(&sched_lock, MA_OWNED); KASSERT((TD_ON_RUNQ(td)), ("adjustrunqueue: Bad state on run queue")); ke = td->td_kse; CTR1(KTR_RUNQ, "adjustrunqueue: td%p", td); /* * If it is not a threaded process, take the shortcut. */ if ((td->td_proc->p_flag & P_HADTHREADS) == 0) { /* We only care about the kse in the run queue. */ td->td_priority = newpri; if (ke->ke_rqindex != (newpri / RQ_PPQ)) { sched_rem(td); sched_add(td, SRQ_BORING); } return; } /* It is a threaded process */ kg = td->td_ksegrp; if (ke->ke_state == KES_ONRUNQ) { if (kg->kg_last_assigned == td) { kg->kg_last_assigned = TAILQ_PREV(td, threadqueue, td_runq); } sched_rem(td); } TAILQ_REMOVE(&kg->kg_runq, td, td_runq); kg->kg_runnable--; TD_SET_CAN_RUN(td); td->td_priority = newpri; setrunqueue(td, SRQ_BORING); }
static int linux_clone_thread(struct thread *td, struct linux_clone_args *args) { struct linux_emuldata *em; struct thread *newtd; struct proc *p; int error; #ifdef DEBUG if (ldebug(clone)) { printf(ARGS(clone, "thread: flags %x, stack %p, parent tid: %p, " "child tid: %p"), (unsigned)args->flags, args->stack, args->parent_tidptr, args->child_tidptr); } #endif LINUX_CTR4(clone_thread, "thread(%d) flags %x ptid %p ctid %p", td->td_tid, (unsigned)args->flags, args->parent_tidptr, args->child_tidptr); if (args->flags & LINUX_CLONE_PARENT_SETTID) if (args->parent_tidptr == NULL) return (EINVAL); /* Threads should be created with own stack */ if (args->stack == NULL) return (EINVAL); p = td->td_proc; #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 = p; thread_cow_get(newtd, td); /* create the emuldata */ linux_proc_init(td, newtd, args->flags); em = em_find(newtd); KASSERT(em != NULL, ("clone_thread: emuldata not found.\n")); if (args->flags & LINUX_CLONE_SETTLS) linux_set_cloned_tls(newtd, args->tls); if (args->flags & LINUX_CLONE_CHILD_SETTID) em->child_set_tid = args->child_tidptr; else em->child_set_tid = NULL; if (args->flags & LINUX_CLONE_CHILD_CLEARTID) em->child_clear_tid = args->child_tidptr; else em->child_clear_tid = NULL; cpu_thread_clean(newtd); linux_set_upcall_kse(newtd, PTROUT(args->stack)); PROC_LOCK(p); p->p_flag |= P_HADTHREADS; bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); if (args->flags & LINUX_CLONE_PARENT) thread_link(newtd, p->p_pptr); else thread_link(newtd, p); 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; PROC_UNLOCK(p); tidhash_add(newtd); #ifdef DEBUG if (ldebug(clone)) printf(ARGS(clone, "successful clone to %d, stack %p"), (int)newtd->td_tid, args->stack); #endif LINUX_CTR2(clone_thread, "thread(%d) successful clone to %d", td->td_tid, newtd->td_tid); if (args->flags & LINUX_CLONE_PARENT_SETTID) { error = copyout(&newtd->td_tid, args->parent_tidptr, sizeof(newtd->td_tid)); if (error) printf(LMSG("clone_thread: copyout failed!")); } /* * Make this runnable after we are finished with it. */ thread_lock(newtd); TD_SET_CAN_RUN(newtd); sched_add(newtd, SRQ_BORING); thread_unlock(newtd); td->td_retval[0] = newtd->td_tid; return (0); fail: #ifdef RACCT if (racct_enable) { PROC_LOCK(p); racct_sub(p, RACCT_NTHR, 1); PROC_UNLOCK(p); } #endif return (error); }
static int linux_clone_proc(struct thread *td, struct linux_clone_args *args) { struct fork_req fr; int error, ff = RFPROC | RFSTOPPED; struct proc *p2; struct thread *td2; int exit_signal; struct linux_emuldata *em; #ifdef DEBUG if (ldebug(clone)) { printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " "child tid: %p"), (unsigned)args->flags, args->stack, args->parent_tidptr, args->child_tidptr); } #endif exit_signal = args->flags & 0x000000ff; if (LINUX_SIG_VALID(exit_signal)) { exit_signal = linux_to_bsd_signal(exit_signal); } else if (exit_signal != 0) return (EINVAL); if (args->flags & LINUX_CLONE_VM) ff |= RFMEM; if (args->flags & LINUX_CLONE_SIGHAND) ff |= RFSIGSHARE; /* * XXX: In Linux, sharing of fs info (chroot/cwd/umask) * and open files is independent. In FreeBSD, its in one * structure but in reality it does not cause any problems * because both of these flags are usually set together. */ if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) ff |= RFFDG; if (args->flags & LINUX_CLONE_PARENT_SETTID) if (args->parent_tidptr == NULL) return (EINVAL); if (args->flags & LINUX_CLONE_VFORK) ff |= RFPPWAIT; bzero(&fr, sizeof(fr)); fr.fr_flags = ff; fr.fr_procp = &p2; error = fork1(td, &fr); if (error) return (error); td2 = FIRST_THREAD_IN_PROC(p2); /* create the emuldata */ linux_proc_init(td, td2, args->flags); em = em_find(td2); KASSERT(em != NULL, ("clone_proc: emuldata not found.\n")); if (args->flags & LINUX_CLONE_CHILD_SETTID) em->child_set_tid = args->child_tidptr; else em->child_set_tid = NULL; if (args->flags & LINUX_CLONE_CHILD_CLEARTID) em->child_clear_tid = args->child_tidptr; else em->child_clear_tid = NULL; if (args->flags & LINUX_CLONE_PARENT_SETTID) { error = copyout(&p2->p_pid, args->parent_tidptr, sizeof(p2->p_pid)); if (error) printf(LMSG("copyout failed!")); } PROC_LOCK(p2); p2->p_sigparent = exit_signal; PROC_UNLOCK(p2); /* * In a case of stack = NULL, we are supposed to COW calling process * stack. This is what normal fork() does, so we just keep tf_rsp arg * intact. */ linux_set_upcall_kse(td2, PTROUT(args->stack)); if (args->flags & LINUX_CLONE_SETTLS) linux_set_cloned_tls(td2, args->tls); /* * If CLONE_PARENT is set, then the parent of the new process will be * the same as that of the calling process. */ if (args->flags & LINUX_CLONE_PARENT) { sx_xlock(&proctree_lock); PROC_LOCK(p2); proc_reparent(p2, td->td_proc->p_pptr); PROC_UNLOCK(p2); sx_xunlock(&proctree_lock); } #ifdef DEBUG if (ldebug(clone)) printf(LMSG("clone: successful rfork to %d, " "stack %p sig = %d"), (int)p2->p_pid, args->stack, exit_signal); #endif /* * Make this runnable after we are finished with it. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); td->td_retval[0] = p2->p_pid; return (0); }
static int create_thread(struct thread *td, mcontext_t *ctx, void (*start_func)(void *), void *arg, char *stack_base, size_t stack_size, char *tls_base, long *child_tid, long *parent_tid, int flags, struct rtprio *rtp) { stack_t stack; struct thread *newtd; struct proc *p; int error; p = td->td_proc; /* Have race condition but it is cheap. */ if (p->p_numthreads >= max_threads_per_proc) { ++max_threads_hits; return (EPROCLIM); } 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 PROC_LOCK(td->td_proc); error = racct_add(p, RACCT_NTHR, 1); PROC_UNLOCK(td->td_proc); if (error != 0) return (EPROCLIM); #endif /* Initialize our td */ newtd = thread_alloc(0); if (newtd == NULL) { error = ENOMEM; goto fail; } cpu_set_upcall(newtd, td); /* * Try the copyout as soon as we allocate the td so we don't * have to tear things down in a failure case below. * 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. */ if ((child_tid != NULL && suword_lwpid(child_tid, newtd->td_tid)) || (parent_tid != NULL && suword_lwpid(parent_tid, newtd->td_tid))) { thread_free(newtd); error = EFAULT; goto fail; } 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_ucred = crhold(td->td_ucred); if (ctx != NULL) { /* old way to set user context */ error = set_mcontext(newtd, ctx); if (error != 0) { thread_free(newtd); crfree(td->td_ucred); goto fail; } } else { /* Set up our machine context. */ stack.ss_sp = stack_base; stack.ss_size = stack_size; /* Set upcall address to user thread entry function. */ cpu_set_upcall_kse(newtd, start_func, arg, &stack); /* Setup user TLS address and TLS pointer register. */ error = cpu_set_user_tls(newtd, tls_base); if (error != 0) { thread_free(newtd); crfree(td->td_ucred); goto fail; } } PROC_LOCK(td->td_proc); td->td_proc->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; PROC_UNLOCK(p); 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 PROC_LOCK(p); racct_sub(p, RACCT_NTHR, 1); PROC_UNLOCK(p); #endif return (error); }
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_set_upcall(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; 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)); newtd->td_pax = p->p_pax; 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_flag2 & P2_LWP_EVENTS) newtd->td_dbgflags |= TDB_BORN; /* * Copy the existing thread VM policy into the new thread. */ vm_domain_policy_localcopy(&newtd->td_vm_dom_policy, &td->td_vm_dom_policy); PROC_UNLOCK(p); 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 linux_clone(struct thread *td, struct linux_clone_args *args) { int error, ff = RFPROC | RFSTOPPED; struct proc *p2; struct thread *td2; int exit_signal; struct linux_emuldata *em; #ifdef DEBUG if (ldebug(clone)) { printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " "child tid: %p"), (unsigned)args->flags, args->stack, args->parent_tidptr, args->child_tidptr); } #endif exit_signal = args->flags & 0x000000ff; if (LINUX_SIG_VALID(exit_signal)) { if (exit_signal <= LINUX_SIGTBLSZ) exit_signal = linux_to_bsd_signal[_SIG_IDX(exit_signal)]; } else if (exit_signal != 0) return (EINVAL); if (args->flags & LINUX_CLONE_VM) ff |= RFMEM; if (args->flags & LINUX_CLONE_SIGHAND) ff |= RFSIGSHARE; /* * XXX: In Linux, sharing of fs info (chroot/cwd/umask) * and open files is independant. In FreeBSD, its in one * structure but in reality it does not cause any problems * because both of these flags are usually set together. */ if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) ff |= RFFDG; /* * Attempt to detect when linux_clone(2) is used for creating * kernel threads. Unfortunately despite the existence of the * CLONE_THREAD flag, version of linuxthreads package used in * most popular distros as of beginning of 2005 doesn't make * any use of it. Therefore, this detection relies on * empirical observation that linuxthreads sets certain * combination of flags, so that we can make more or less * precise detection and notify the FreeBSD kernel that several * processes are in fact part of the same threading group, so * that special treatment is necessary for signal delivery * between those processes and fd locking. */ if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS) ff |= RFTHREAD; if (args->flags & LINUX_CLONE_PARENT_SETTID) if (args->parent_tidptr == NULL) return (EINVAL); error = fork1(td, ff, 0, &p2, NULL, 0); if (error) return (error); if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) { sx_xlock(&proctree_lock); PROC_LOCK(p2); proc_reparent(p2, td->td_proc->p_pptr); PROC_UNLOCK(p2); sx_xunlock(&proctree_lock); } /* create the emuldata */ error = linux_proc_init(td, p2->p_pid, args->flags); /* reference it - no need to check this */ em = em_find(p2, EMUL_DOLOCK); KASSERT(em != NULL, ("clone: emuldata not found.")); /* and adjust it */ if (args->flags & LINUX_CLONE_THREAD) { #ifdef notyet PROC_LOCK(p2); p2->p_pgrp = td->td_proc->p_pgrp; PROC_UNLOCK(p2); #endif exit_signal = 0; } if (args->flags & LINUX_CLONE_CHILD_SETTID) em->child_set_tid = args->child_tidptr; else em->child_set_tid = NULL; if (args->flags & LINUX_CLONE_CHILD_CLEARTID) em->child_clear_tid = args->child_tidptr; else em->child_clear_tid = NULL; EMUL_UNLOCK(&emul_lock); if (args->flags & LINUX_CLONE_PARENT_SETTID) { error = copyout(&p2->p_pid, args->parent_tidptr, sizeof(p2->p_pid)); if (error) printf(LMSG("copyout failed!")); } PROC_LOCK(p2); p2->p_sigparent = exit_signal; PROC_UNLOCK(p2); td2 = FIRST_THREAD_IN_PROC(p2); /* * In a case of stack = NULL, we are supposed to COW calling process * stack. This is what normal fork() does, so we just keep tf_rsp arg * intact. */ if (args->stack) linux_set_upcall_kse(td2, PTROUT(args->stack)); if (args->flags & LINUX_CLONE_SETTLS) linux_set_cloned_tls(td2, args->tls); #ifdef DEBUG if (ldebug(clone)) printf(LMSG("clone: successful rfork to %d, " "stack %p sig = %d"), (int)p2->p_pid, args->stack, exit_signal); #endif if (args->flags & LINUX_CLONE_VFORK) { PROC_LOCK(p2); p2->p_flag |= P_PPWAIT; PROC_UNLOCK(p2); } /* * Make this runnable after we are finished with it. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); td->td_retval[0] = p2->p_pid; td->td_retval[1] = 0; if (args->flags & LINUX_CLONE_VFORK) { /* wait for the children to exit, ie. emulate vfork */ PROC_LOCK(p2); while (p2->p_flag & P_PPWAIT) cv_wait(&p2->p_pwait, &p2->p_mtx); PROC_UNLOCK(p2); } return (0); }
static void do_fork(struct thread *td, struct fork_req *fr, struct proc *p2, struct thread *td2, struct vmspace *vm2, struct file *fp_procdesc) { struct proc *p1, *pptr; int trypid; struct filedesc *fd; struct filedesc_to_leader *fdtol; struct sigacts *newsigacts; sx_assert(&proctree_lock, SX_SLOCKED); sx_assert(&allproc_lock, SX_XLOCKED); p1 = td->td_proc; trypid = fork_findpid(fr->fr_flags); sx_sunlock(&proctree_lock); p2->p_state = PRS_NEW; /* protect against others */ p2->p_pid = trypid; AUDIT_ARG_PID(p2->p_pid); LIST_INSERT_HEAD(&allproc, p2, p_list); allproc_gen++; LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash); tidhash_add(td2); PROC_LOCK(p2); PROC_LOCK(p1); sx_xunlock(&allproc_lock); bcopy(&p1->p_startcopy, &p2->p_startcopy, __rangeof(struct proc, p_startcopy, p_endcopy)); pargs_hold(p2->p_args); PROC_UNLOCK(p1); bzero(&p2->p_startzero, __rangeof(struct proc, p_startzero, p_endzero)); /* Tell the prison that we exist. */ prison_proc_hold(p2->p_ucred->cr_prison); PROC_UNLOCK(p2); /* * Malloc things while we don't hold any locks. */ if (fr->fr_flags & RFSIGSHARE) newsigacts = NULL; else newsigacts = sigacts_alloc(); /* * Copy filedesc. */ if (fr->fr_flags & RFCFDG) { fd = fdinit(p1->p_fd, false); fdtol = NULL; } else if (fr->fr_flags & RFFDG) { fd = fdcopy(p1->p_fd); fdtol = NULL; } else { fd = fdshare(p1->p_fd); if (p1->p_fdtol == NULL) p1->p_fdtol = filedesc_to_leader_alloc(NULL, NULL, p1->p_leader); if ((fr->fr_flags & RFTHREAD) != 0) { /* * Shared file descriptor table, and shared * process leaders. */ fdtol = p1->p_fdtol; FILEDESC_XLOCK(p1->p_fd); fdtol->fdl_refcount++; FILEDESC_XUNLOCK(p1->p_fd); } else { /* * Shared file descriptor table, and different * process leaders. */ fdtol = filedesc_to_leader_alloc(p1->p_fdtol, p1->p_fd, p2); } } /* * Make a proc table entry for the new process. * Start by zeroing the section of proc that is zero-initialized, * then copy the section that is copied directly from the parent. */ PROC_LOCK(p2); PROC_LOCK(p1); bzero(&td2->td_startzero, __rangeof(struct thread, td_startzero, td_endzero)); bcopy(&td->td_startcopy, &td2->td_startcopy, __rangeof(struct thread, td_startcopy, td_endcopy)); bcopy(&p2->p_comm, &td2->td_name, sizeof(td2->td_name)); td2->td_sigstk = td->td_sigstk; td2->td_flags = TDF_INMEM; td2->td_lend_user_pri = PRI_MAX; #ifdef VIMAGE td2->td_vnet = NULL; td2->td_vnet_lpush = NULL; #endif /* * Allow the scheduler to initialize the child. */ thread_lock(td); sched_fork(td, td2); thread_unlock(td); /* * Duplicate sub-structures as needed. * Increase reference counts on shared objects. */ p2->p_flag = P_INMEM; p2->p_flag2 = p1->p_flag2 & (P2_NOTRACE | P2_NOTRACE_EXEC | P2_TRAPCAP); p2->p_swtick = ticks; if (p1->p_flag & P_PROFIL) startprofclock(p2); /* * Whilst the proc lock is held, copy the VM domain data out * using the VM domain method. */ vm_domain_policy_init(&p2->p_vm_dom_policy); vm_domain_policy_localcopy(&p2->p_vm_dom_policy, &p1->p_vm_dom_policy); if (fr->fr_flags & RFSIGSHARE) { p2->p_sigacts = sigacts_hold(p1->p_sigacts); } else { sigacts_copy(newsigacts, p1->p_sigacts); p2->p_sigacts = newsigacts; } if (fr->fr_flags & RFTSIGZMB) p2->p_sigparent = RFTSIGNUM(fr->fr_flags); else if (fr->fr_flags & RFLINUXTHPN) p2->p_sigparent = SIGUSR1; else p2->p_sigparent = SIGCHLD; p2->p_textvp = p1->p_textvp; p2->p_fd = fd; p2->p_fdtol = fdtol; if (p1->p_flag2 & P2_INHERIT_PROTECTED) { p2->p_flag |= P_PROTECTED; p2->p_flag2 |= P2_INHERIT_PROTECTED; } /* * p_limit is copy-on-write. Bump its refcount. */ lim_fork(p1, p2); thread_cow_get_proc(td2, p2); pstats_fork(p1->p_stats, p2->p_stats); PROC_UNLOCK(p1); PROC_UNLOCK(p2); /* Bump references to the text vnode (for procfs). */ if (p2->p_textvp) vrefact(p2->p_textvp); /* * Set up linkage for kernel based threading. */ if ((fr->fr_flags & RFTHREAD) != 0) { mtx_lock(&ppeers_lock); p2->p_peers = p1->p_peers; p1->p_peers = p2; p2->p_leader = p1->p_leader; mtx_unlock(&ppeers_lock); PROC_LOCK(p1->p_leader); if ((p1->p_leader->p_flag & P_WEXIT) != 0) { PROC_UNLOCK(p1->p_leader); /* * The task leader is exiting, so process p1 is * going to be killed shortly. Since p1 obviously * isn't dead yet, we know that the leader is either * sending SIGKILL's to all the processes in this * task or is sleeping waiting for all the peers to * exit. We let p1 complete the fork, but we need * to go ahead and kill the new process p2 since * the task leader may not get a chance to send * SIGKILL to it. We leave it on the list so that * the task leader will wait for this new process * to commit suicide. */ PROC_LOCK(p2); kern_psignal(p2, SIGKILL); PROC_UNLOCK(p2); } else PROC_UNLOCK(p1->p_leader); } else { p2->p_peers = NULL; p2->p_leader = p2; } sx_xlock(&proctree_lock); PGRP_LOCK(p1->p_pgrp); PROC_LOCK(p2); PROC_LOCK(p1); /* * Preserve some more flags in subprocess. P_PROFIL has already * been preserved. */ p2->p_flag |= p1->p_flag & P_SUGID; td2->td_pflags |= (td->td_pflags & TDP_ALTSTACK) | TDP_FORKING; SESS_LOCK(p1->p_session); if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT) p2->p_flag |= P_CONTROLT; SESS_UNLOCK(p1->p_session); if (fr->fr_flags & RFPPWAIT) p2->p_flag |= P_PPWAIT; p2->p_pgrp = p1->p_pgrp; LIST_INSERT_AFTER(p1, p2, p_pglist); PGRP_UNLOCK(p1->p_pgrp); LIST_INIT(&p2->p_children); LIST_INIT(&p2->p_orphans); callout_init_mtx(&p2->p_itcallout, &p2->p_mtx, 0); /* * If PF_FORK is set, the child process inherits the * procfs ioctl flags from its parent. */ if (p1->p_pfsflags & PF_FORK) { p2->p_stops = p1->p_stops; p2->p_pfsflags = p1->p_pfsflags; } /* * This begins the section where we must prevent the parent * from being swapped. */ _PHOLD(p1); PROC_UNLOCK(p1); /* * Attach the new process to its parent. * * If RFNOWAIT is set, the newly created process becomes a child * of init. This effectively disassociates the child from the * parent. */ if ((fr->fr_flags & RFNOWAIT) != 0) { pptr = p1->p_reaper; p2->p_reaper = pptr; } else { p2->p_reaper = (p1->p_treeflag & P_TREE_REAPER) != 0 ? p1 : p1->p_reaper; pptr = p1; } p2->p_pptr = pptr; LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling); LIST_INIT(&p2->p_reaplist); LIST_INSERT_HEAD(&p2->p_reaper->p_reaplist, p2, p_reapsibling); if (p2->p_reaper == p1) p2->p_reapsubtree = p2->p_pid; sx_xunlock(&proctree_lock); /* Inform accounting that we have forked. */ p2->p_acflag = AFORK; PROC_UNLOCK(p2); #ifdef KTRACE ktrprocfork(p1, p2); #endif /* * Finish creating the child process. It will return via a different * execution path later. (ie: directly into user mode) */ vm_forkproc(td, p2, td2, vm2, fr->fr_flags); if (fr->fr_flags == (RFFDG | RFPROC)) { VM_CNT_INC(v_forks); VM_CNT_ADD(v_forkpages, p2->p_vmspace->vm_dsize + p2->p_vmspace->vm_ssize); } else if (fr->fr_flags == (RFFDG | RFPROC | RFPPWAIT | RFMEM)) { VM_CNT_INC(v_vforks); VM_CNT_ADD(v_vforkpages, p2->p_vmspace->vm_dsize + p2->p_vmspace->vm_ssize); } else if (p1 == &proc0) { VM_CNT_INC(v_kthreads); VM_CNT_ADD(v_kthreadpages, p2->p_vmspace->vm_dsize + p2->p_vmspace->vm_ssize); } else { VM_CNT_INC(v_rforks); VM_CNT_ADD(v_rforkpages, p2->p_vmspace->vm_dsize + p2->p_vmspace->vm_ssize); } /* * Associate the process descriptor with the process before anything * can happen that might cause that process to need the descriptor. * However, don't do this until after fork(2) can no longer fail. */ if (fr->fr_flags & RFPROCDESC) procdesc_new(p2, fr->fr_pd_flags); /* * Both processes are set up, now check if any loadable modules want * to adjust anything. */ EVENTHANDLER_INVOKE(process_fork, p1, p2, fr->fr_flags); /* * Set the child start time and mark the process as being complete. */ PROC_LOCK(p2); PROC_LOCK(p1); microuptime(&p2->p_stats->p_start); PROC_SLOCK(p2); p2->p_state = PRS_NORMAL; PROC_SUNLOCK(p2); #ifdef KDTRACE_HOOKS /* * Tell the DTrace fasttrap provider about the new process so that any * tracepoints inherited from the parent can be removed. We have to do * this only after p_state is PRS_NORMAL since the fasttrap module will * use pfind() later on. */ if ((fr->fr_flags & RFMEM) == 0 && dtrace_fasttrap_fork) dtrace_fasttrap_fork(p1, p2); #endif /* * Hold the process so that it cannot exit after we make it runnable, * but before we wait for the debugger. */ _PHOLD(p2); if (p1->p_ptevents & PTRACE_FORK) { /* * Arrange for debugger to receive the fork event. * * We can report PL_FLAG_FORKED regardless of * P_FOLLOWFORK settings, but it does not make a sense * for runaway child. */ td->td_dbgflags |= TDB_FORK; td->td_dbg_forked = p2->p_pid; td2->td_dbgflags |= TDB_STOPATFORK; } if (fr->fr_flags & RFPPWAIT) { td->td_pflags |= TDP_RFPPWAIT; td->td_rfppwait_p = p2; td->td_dbgflags |= TDB_VFORK; } PROC_UNLOCK(p2); /* * Now can be swapped. */ _PRELE(p1); PROC_UNLOCK(p1); /* * Tell any interested parties about the new process. */ knote_fork(p1->p_klist, p2->p_pid); SDT_PROBE3(proc, , , create, p2, p1, fr->fr_flags); if (fr->fr_flags & RFPROCDESC) { procdesc_finit(p2->p_procdesc, fp_procdesc); fdrop(fp_procdesc, td); } if ((fr->fr_flags & RFSTOPPED) == 0) { /* * If RFSTOPPED not requested, make child runnable and * add to run queue. */ thread_lock(td2); TD_SET_CAN_RUN(td2); sched_add(td2, SRQ_BORING); thread_unlock(td2); if (fr->fr_pidp != NULL) *fr->fr_pidp = p2->p_pid; } else { *fr->fr_procp = p2; } PROC_LOCK(p2); /* * Wait until debugger is attached to child. */ while (td2->td_proc == p2 && (td2->td_dbgflags & TDB_STOPATFORK) != 0) cv_wait(&p2->p_dbgwait, &p2->p_mtx); _PRELE(p2); racct_proc_fork_done(p2); PROC_UNLOCK(p2); }
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); }
/* * 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, ...) { 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_pages = pages; fr.fr_procp = &p2; error = fork1(&thread0, &fr); if (error) return error; /* save a global descriptor, if desired */ if (newpp != NULL) *newpp = p2; /* this is a non-swapped system process */ PROC_LOCK(p2); td = FIRST_THREAD_IN_PROC(p2); p2->p_flag |= P_SYSTEM | P_KTHREAD; td->td_pflags |= TDP_KTHREAD; mtx_lock(&p2->p_sigacts->ps_mtx); p2->p_sigacts->ps_flag |= PS_NOCLDWAIT; mtx_unlock(&p2->p_sigacts->ps_mtx); PROC_UNLOCK(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); /* set up arg0 for 'ps', et al */ va_start(ap, fmt); vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap); va_end(ap); #ifdef KTR sched_clear_tdname(td); #endif /* call the processes' main()... */ cpu_set_fork_handler(td, func, arg); /* Avoid inheriting affinity from a random parent. */ cpuset_setthread(td->td_tid, cpuset_root); 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)) sched_add(td, SRQ_BORING); thread_unlock(td); return 0; }
/* * 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, ...) { 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); newtd->td_proc = p; /* needed for cpu_set_upcall */ /* XXX optimise this probably? */ /* On x86 (and probably the others too) it is way too full of junk */ /* Needs a better name */ cpu_set_upcall(newtd, oldtd); /* put the designated function(arg) as the resume context */ cpu_set_fork_handler(newtd, func, arg); newtd->td_pflags |= TDP_KTHREAD; thread_cow_get_proc(newtd, p); /* this code almost the same as create_thread() 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_setthread(newtd->td_tid, cpuset_root); /* Delay putting it on the run queue until now. */ if (!(flags & RFSTOPPED)) { thread_lock(newtd); sched_add(newtd, SRQ_BORING); thread_unlock(newtd); } if (newtdp) *newtdp = newtd; return 0; }