int do_getitimer(int which, struct itimerval *value) { struct task_struct *tsk = current; cputime_t cinterval, cval; switch (which) { case ITIMER_REAL: spin_lock_irq(&tsk->sighand->siglock); value->it_value = itimer_get_remtime(&tsk->signal->real_timer); value->it_interval = ktime_to_timeval(tsk->signal->it_real_incr); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; if (!cputime_eq(cval, cputime_zero)) { struct task_cputime cputime; cputime_t utime; thread_group_cputimer(tsk, &cputime); utime = cputime.utime; if (cputime_le(cval, utime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { cval = cputime_sub(cval, utime); } } spin_unlock_irq(&tsk->sighand->siglock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; case ITIMER_PROF: spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; if (!cputime_eq(cval, cputime_zero)) { struct task_cputime times; cputime_t ptime; thread_group_cputimer(tsk, ×); ptime = cputime_add(times.utime, times.stime); if (cputime_le(cval, ptime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { cval = cputime_sub(cval, ptime); } } spin_unlock_irq(&tsk->sighand->siglock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; default: return(-EINVAL); } return 0; }
static ushort thread_group_cpu_share(struct task_struct *task) { struct task_cputime times; cputime_t num_load, div_load, total_time; ushort share; my_thread_group_cputime(task, ×); total_time = cputime_add(times.utime, times.stime); /* last_cputime == 0 means that the timer_function has been called for the first time and we have to collect info before doing any check. */ if (unlikely(last_cputime == 0)) { share = 0; printk(KERN_INFO "sendsig: timer initialization completed\n"); } else { /* Let's compute the share of cpu usage for the last WAIT_TIMEOUT seconds */ num_load = cputime_sub(total_time, last_cputime) * 100; div_load = jiffies_to_cputime(wait_timeout * HZ); share = (ushort)cputime_div(num_load, div_load); printk(KERN_DEBUG "sendsig: computed cpu share for process %d: %d\n", pid, share); } /* Update last_cputime */ last_cputime = total_time; return share; }
/* * Account multiple ticks of idle time. * @ticks: number of stolen ticks */ void account_idle_ticks(unsigned long ticks) { if (sched_clock_irqtime) { irqtime_account_idle_ticks(ticks); return; } account_idle_time(jiffies_to_cputime(ticks)); }
/* * This creates a new process as a copy of the old one, * but does not actually start it yet. * * It copies the registers, and all the appropriate * parts of the process environment (as per the clone * flags). The actual kick-off is left to the caller. */ static struct task_struct *copy_process(unsigned long clone_flags, unsigned long stack_start, struct pt_regs *regs, unsigned long stack_size, int __user *child_tidptr, struct pid *pid, int trace) { int retval; struct task_struct *p; int cgroup_callbacks_done = 0; if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) return ERR_PTR(-EINVAL); /* * Thread groups must share signals as well, and detached threads * can only be started up within the thread group. */ if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); /* * Shared signal handlers imply shared VM. By way of the above, * thread groups also imply shared VM. Blocking this case allows * for various simplifications in other code. */ if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM)) return ERR_PTR(-EINVAL); retval = security_task_create(clone_flags); if (retval) goto fork_out; retval = -ENOMEM; p = dup_task_struct(current); if (!p) goto fork_out; rt_mutex_init_task(p); #ifdef CONFIG_PROVE_LOCKING DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif retval = -EAGAIN; if (atomic_read(&p->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && p->user != current->nsproxy->user_ns->root_user) goto bad_fork_free; } atomic_inc(&p->user->__count); atomic_inc(&p->user->processes); get_group_info(p->group_info); /* * If multiple threads are within copy_process(), then this check * triggers too late. This doesn't hurt, the check is only there * to stop root fork bombs. */ if (nr_threads >= max_threads) goto bad_fork_cleanup_count; if (!try_module_get(task_thread_info(p)->exec_domain->module)) goto bad_fork_cleanup_count; if (p->binfmt && !try_module_get(p->binfmt->module)) goto bad_fork_cleanup_put_domain; p->did_exec = 0; delayacct_tsk_init(p); /* Must remain after dup_task_struct() */ copy_flags(clone_flags, p); INIT_LIST_HEAD(&p->children); INIT_LIST_HEAD(&p->sibling); #ifdef CONFIG_PREEMPT_RCU p->rcu_read_lock_nesting = 0; p->rcu_flipctr_idx = 0; #endif /* #ifdef CONFIG_PREEMPT_RCU */ p->vfork_done = NULL; spin_lock_init(&p->alloc_lock); clear_tsk_thread_flag(p, TIF_SIGPENDING); init_sigpending(&p->pending); p->utime = cputime_zero; p->stime = cputime_zero; p->gtime = cputime_zero; p->utimescaled = cputime_zero; p->stimescaled = cputime_zero; p->prev_utime = cputime_zero; p->prev_stime = cputime_zero; #ifdef CONFIG_DETECT_SOFTLOCKUP p->last_switch_count = 0; p->last_switch_timestamp = 0; #endif task_io_accounting_init(&p->ioac); acct_clear_integrals(p); p->it_virt_expires = cputime_zero; p->it_prof_expires = cputime_zero; p->it_sched_expires = 0; INIT_LIST_HEAD(&p->cpu_timers[0]); INIT_LIST_HEAD(&p->cpu_timers[1]); INIT_LIST_HEAD(&p->cpu_timers[2]); p->lock_depth = -1; /* -1 = no lock */ do_posix_clock_monotonic_gettime(&p->start_time); p->real_start_time = p->start_time; monotonic_to_bootbased(&p->real_start_time); #ifdef CONFIG_SECURITY p->security = NULL; #endif p->cap_bset = current->cap_bset; p->io_context = NULL; p->audit_context = NULL; cgroup_fork(p); #ifdef CONFIG_NUMA p->mempolicy = mpol_dup(p->mempolicy); if (IS_ERR(p->mempolicy)) { retval = PTR_ERR(p->mempolicy); p->mempolicy = NULL; goto bad_fork_cleanup_cgroup; } mpol_fix_fork_child_flag(p); #endif #ifdef CONFIG_TRACE_IRQFLAGS p->irq_events = 0; #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW p->hardirqs_enabled = 1; #else p->hardirqs_enabled = 0; #endif p->hardirq_enable_ip = 0; p->hardirq_enable_event = 0; p->hardirq_disable_ip = _THIS_IP_; p->hardirq_disable_event = 0; p->softirqs_enabled = 1; p->softirq_enable_ip = _THIS_IP_; p->softirq_enable_event = 0; p->softirq_disable_ip = 0; p->softirq_disable_event = 0; p->hardirq_context = 0; p->softirq_context = 0; #endif #ifdef CONFIG_LOCKDEP p->lockdep_depth = 0; /* no locks held yet */ p->curr_chain_key = 0; p->lockdep_recursion = 0; #endif #ifdef CONFIG_DEBUG_MUTEXES p->blocked_on = NULL; /* not blocked yet */ #endif /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); if ((retval = security_task_alloc(p))) goto bad_fork_cleanup_policy; if ((retval = audit_alloc(p))) goto bad_fork_cleanup_security; /* copy all the process information */ if ((retval = copy_semundo(clone_flags, p))) goto bad_fork_cleanup_audit; if ((retval = copy_files(clone_flags, p))) goto bad_fork_cleanup_semundo; if ((retval = copy_fs(clone_flags, p))) goto bad_fork_cleanup_files; if ((retval = copy_sighand(clone_flags, p))) goto bad_fork_cleanup_fs; if ((retval = copy_signal(clone_flags, p))) goto bad_fork_cleanup_sighand; if ((retval = copy_mm(clone_flags, p))) goto bad_fork_cleanup_signal; if ((retval = copy_keys(clone_flags, p))) goto bad_fork_cleanup_mm; if ((retval = copy_namespaces(clone_flags, p))) goto bad_fork_cleanup_keys; if ((retval = copy_io(clone_flags, p))) goto bad_fork_cleanup_namespaces; retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); if (retval) goto bad_fork_cleanup_io; if (pid != &init_struct_pid) { retval = -ENOMEM; pid = alloc_pid(task_active_pid_ns(p)); if (!pid) goto bad_fork_cleanup_io; if (clone_flags & CLONE_NEWPID) { retval = pid_ns_prepare_proc(task_active_pid_ns(p)); if (retval < 0) goto bad_fork_free_pid; } } p->pid = pid_nr(pid); p->tgid = p->pid; if (clone_flags & CLONE_THREAD) p->tgid = current->tgid; if (current->nsproxy != p->nsproxy) { retval = ns_cgroup_clone(p, pid); if (retval) goto bad_fork_free_pid; } p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; /* * Clear TID on mm_release()? */ p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL; #ifdef CONFIG_FUTEX p->robust_list = NULL; #ifdef CONFIG_COMPAT p->compat_robust_list = NULL; #endif INIT_LIST_HEAD(&p->pi_state_list); p->pi_state_cache = NULL; #endif /* * sigaltstack should be cleared when sharing the same VM */ if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM) p->sas_ss_sp = p->sas_ss_size = 0; /* * Syscall tracing should be turned off in the child regardless * of CLONE_PTRACE. */ clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE); #ifdef TIF_SYSCALL_EMU clear_tsk_thread_flag(p, TIF_SYSCALL_EMU); #endif clear_all_latency_tracing(p); /* ok, now we should be set up.. */ p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL); p->pdeath_signal = 0; p->exit_state = 0; /* * Ok, make it visible to the rest of the system. * We dont wake it up yet. */ p->group_leader = p; INIT_LIST_HEAD(&p->thread_group); /* Now that the task is set up, run cgroup callbacks if * necessary. We need to run them before the task is visible * on the tasklist. */ cgroup_fork_callbacks(p); cgroup_callbacks_done = 1; /* Need tasklist lock for parent etc handling! */ write_lock_irq(&tasklist_lock); /* * The task hasn't been attached yet, so its cpus_allowed mask will * not be changed, nor will its assigned CPU. * * The cpus_allowed mask of the parent may have changed after it was * copied first time - so re-copy it here, then check the child's CPU * to ensure it is on a valid CPU (and if not, just force it back to * parent's CPU). This avoids alot of nasty races. */ p->cpus_allowed = current->cpus_allowed; if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || !cpu_online(task_cpu(p)))) set_task_cpu(p, smp_processor_id()); /* CLONE_PARENT re-uses the old parent */ if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) { p->real_parent = current->real_parent; p->parent_exec_id = current->parent_exec_id; } else { p->real_parent = current; p->parent_exec_id = current->self_exec_id; } spin_lock(¤t->sighand->siglock); /* * Process group and session signals need to be delivered to just the * parent before the fork or both the parent and the child after the * fork. Restart if a signal comes in before we add the new process to * it's process group. * A fatal signal pending means that current will exit, so the new * thread can't slip out of an OOM kill (or normal SIGKILL). */ recalc_sigpending(); if (signal_pending(current)) { spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); retval = -ERESTARTNOINTR; goto bad_fork_free_pid; } if (clone_flags & CLONE_THREAD) { atomic_inc(¤t->signal->count); atomic_inc(¤t->signal->live); p->group_leader = current->group_leader; list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group); if (!cputime_eq(current->signal->it_virt_expires, cputime_zero) || !cputime_eq(current->signal->it_prof_expires, cputime_zero) || current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY || !list_empty(¤t->signal->cpu_timers[0]) || !list_empty(¤t->signal->cpu_timers[1]) || !list_empty(¤t->signal->cpu_timers[2])) { /* * Have child wake up on its first tick to check * for process CPU timers. */ p->it_prof_expires = jiffies_to_cputime(1); } } if (likely(p->pid)) { list_add_tail(&p->sibling, &p->real_parent->children); tracehook_finish_clone(p, clone_flags, trace); if (thread_group_leader(p)) { if (clone_flags & CLONE_NEWPID) p->nsproxy->pid_ns->child_reaper = p; p->signal->leader_pid = pid; p->signal->tty = current->signal->tty; set_task_pgrp(p, task_pgrp_nr(current)); set_task_session(p, task_session_nr(current)); attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); attach_pid(p, PIDTYPE_SID, task_session(current)); list_add_tail_rcu(&p->tasks, &init_task.tasks); __get_cpu_var(process_counts)++; } attach_pid(p, PIDTYPE_PID, pid); nr_threads++; } total_forks++; spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); proc_fork_connector(p); cgroup_post_fork(p); return p; bad_fork_free_pid: if (pid != &init_struct_pid) free_pid(pid); bad_fork_cleanup_io: put_io_context(p->io_context); bad_fork_cleanup_namespaces: exit_task_namespaces(p); bad_fork_cleanup_keys: exit_keys(p); bad_fork_cleanup_mm: if (p->mm) mmput(p->mm); bad_fork_cleanup_signal: if (!(clone_flags & CLONE_THREAD)) __cleanup_signal(p->signal); bad_fork_cleanup_sighand: __cleanup_sighand(p->sighand); bad_fork_cleanup_fs: exit_fs(p); /* blocking */ bad_fork_cleanup_files: exit_files(p); /* blocking */ bad_fork_cleanup_semundo: exit_sem(p); bad_fork_cleanup_audit: audit_free(p); bad_fork_cleanup_security: security_task_free(p); bad_fork_cleanup_policy: #ifdef CONFIG_NUMA mpol_put(p->mempolicy); bad_fork_cleanup_cgroup: #endif cgroup_exit(p, cgroup_callbacks_done); delayacct_tsk_free(p); if (p->binfmt) module_put(p->binfmt->module); bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: put_group_info(p->group_info); atomic_dec(&p->user->processes); free_uid(p->user); bad_fork_free: free_task(p); fork_out: return ERR_PTR(retval); }
/* * Account multiple ticks of steal time. * @p: the process from which the cpu time has been stolen * @ticks: number of stolen ticks */ void account_steal_ticks(unsigned long ticks) { account_steal_time(jiffies_to_cputime(ticks)); }
/** * nohz_restart_sched_tick - restart the idle tick from the idle task * * Restart the idle tick when the CPU is woken up from idle */ void tick_nohz_restart_sched_tick(void) { int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); unsigned long ticks; ktime_t now, delta; if (!ts->tick_stopped) return; /* Update jiffies first */ now = ktime_get(); local_irq_disable(); tick_do_update_jiffies64(now); cpu_clear(cpu, nohz_cpu_mask); /* Account the idle time */ delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); /* * We stopped the tick in idle. Update process times would miss the * time we slept as update_process_times does only a 1 tick * accounting. Enforce that this is accounted to idle ! */ ticks = jiffies - ts->idle_jiffies; /* * We might be one off. Do not randomly account a huge number of ticks! */ if (ticks && ticks < LONG_MAX) { add_preempt_count(HARDIRQ_OFFSET); account_system_time(current, HARDIRQ_OFFSET, jiffies_to_cputime(ticks)); sub_preempt_count(HARDIRQ_OFFSET); } /* * Cancel the scheduled timer and restore the tick */ ts->tick_stopped = 0; hrtimer_cancel(&ts->sched_timer); ts->sched_timer.expires = ts->idle_tick; while (1) { /* Forward the time to expire in the future */ hrtimer_forward(&ts->sched_timer, now, tick_period); if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { hrtimer_start(&ts->sched_timer, ts->sched_timer.expires, HRTIMER_MODE_ABS); /* Check, if the timer was already in the past */ if (hrtimer_active(&ts->sched_timer)) break; } else { if (!tick_program_event(ts->sched_timer.expires, 0)) break; } /* Update jiffies and reread time */ tick_do_update_jiffies64(now); now = ktime_get(); } local_irq_enable(); }
/* * This creates a new process as a copy of the old one, * but does not actually start it yet. * * It copies the registers, and all the appropriate * parts of the process environment (as per the clone * flags). The actual kick-off is left to the caller. */ static task_t *copy_process(unsigned long clone_flags, unsigned long stack_start, struct pt_regs *regs, unsigned long stack_size, int __user *parent_tidptr, int __user *child_tidptr, int pid) { int retval; struct task_struct *p = NULL; if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) return ERR_PTR(-EINVAL); /* * Thread groups must share signals as well, and detached threads * can only be started up within the thread group. */ if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); /* * Shared signal handlers imply shared VM. By way of the above, * thread groups also imply shared VM. Blocking this case allows * for various simplifications in other code. */ if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM)) return ERR_PTR(-EINVAL); retval = security_task_create(clone_flags); if (retval) goto fork_out; retval = -ENOMEM; p = dup_task_struct(current); if (!p) goto fork_out; retval = -EAGAIN; if (atomic_read(&p->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && p->user != &root_user) goto bad_fork_free; } atomic_inc(&p->user->__count); atomic_inc(&p->user->processes); get_group_info(p->group_info); /* * If multiple threads are within copy_process(), then this check * triggers too late. This doesn't hurt, the check is only there * to stop root fork bombs. */ if (nr_threads >= max_threads) goto bad_fork_cleanup_count; if (!try_module_get(p->thread_info->exec_domain->module)) goto bad_fork_cleanup_count; if (p->binfmt && !try_module_get(p->binfmt->module)) goto bad_fork_cleanup_put_domain; p->did_exec = 0; copy_flags(clone_flags, p); p->pid = pid; retval = -EFAULT; if (clone_flags & CLONE_PARENT_SETTID) if (put_user(p->pid, parent_tidptr)) goto bad_fork_cleanup; p->proc_dentry = NULL; INIT_LIST_HEAD(&p->children); INIT_LIST_HEAD(&p->sibling); p->vfork_done = NULL; spin_lock_init(&p->alloc_lock); spin_lock_init(&p->proc_lock); clear_tsk_thread_flag(p, TIF_SIGPENDING); init_sigpending(&p->pending); p->utime = cputime_zero; p->stime = cputime_zero; p->sched_time = 0; p->rchar = 0; /* I/O counter: bytes read */ p->wchar = 0; /* I/O counter: bytes written */ p->syscr = 0; /* I/O counter: read syscalls */ p->syscw = 0; /* I/O counter: write syscalls */ acct_clear_integrals(p); p->it_virt_expires = cputime_zero; p->it_prof_expires = cputime_zero; p->it_sched_expires = 0; INIT_LIST_HEAD(&p->cpu_timers[0]); INIT_LIST_HEAD(&p->cpu_timers[1]); INIT_LIST_HEAD(&p->cpu_timers[2]); p->lock_depth = -1; /* -1 = no lock */ do_posix_clock_monotonic_gettime(&p->start_time); p->security = NULL; p->io_context = NULL; p->io_wait = NULL; p->audit_context = NULL; #ifdef CONFIG_NUMA p->mempolicy = mpol_copy(p->mempolicy); if (IS_ERR(p->mempolicy)) { retval = PTR_ERR(p->mempolicy); p->mempolicy = NULL; goto bad_fork_cleanup; } #endif p->tgid = p->pid; if (clone_flags & CLONE_THREAD) p->tgid = current->tgid; if ((retval = security_task_alloc(p))) goto bad_fork_cleanup_policy; if ((retval = audit_alloc(p))) goto bad_fork_cleanup_security; /* copy all the process information */ if ((retval = copy_semundo(clone_flags, p))) goto bad_fork_cleanup_audit; if ((retval = copy_files(clone_flags, p))) goto bad_fork_cleanup_semundo; if ((retval = copy_fs(clone_flags, p))) goto bad_fork_cleanup_files; if ((retval = copy_sighand(clone_flags, p))) goto bad_fork_cleanup_fs; if ((retval = copy_signal(clone_flags, p))) goto bad_fork_cleanup_sighand; if ((retval = copy_mm(clone_flags, p))) goto bad_fork_cleanup_signal; if ((retval = copy_keys(clone_flags, p))) goto bad_fork_cleanup_mm; if ((retval = copy_namespace(clone_flags, p))) goto bad_fork_cleanup_keys; retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); if (retval) goto bad_fork_cleanup_namespace; p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; /* * Clear TID on mm_release()? */ p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL; /* * Syscall tracing should be turned off in the child regardless * of CLONE_PTRACE. */ clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE); #ifdef TIF_SYSCALL_EMU clear_tsk_thread_flag(p, TIF_SYSCALL_EMU); #endif /* Our parent execution domain becomes current domain These must match for thread signalling to apply */ p->parent_exec_id = p->self_exec_id; #ifdef CONFIG_LTT_USERSPACE_GENERIC if (clone_flags & CLONE_THREAD) memset(p->ltt_facilities, 0, sizeof(p->ltt_facilities)); else { int i; for(i=0; i<LTT_FAC_PER_PROCESS; i++) { p->ltt_facilities[i] = current->ltt_facilities[i]; if(p->ltt_facilities[i] != 0) ltt_facility_ref(p->ltt_facilities[i]); } } #endif //CONFIG_LTT_USERSPACE_GENERIC /* ok, now we should be set up.. */ p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL); p->pdeath_signal = 0; p->exit_state = 0; /* * Ok, make it visible to the rest of the system. * We dont wake it up yet. */ p->group_leader = p; INIT_LIST_HEAD(&p->ptrace_children); INIT_LIST_HEAD(&p->ptrace_list); /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); /* Need tasklist lock for parent etc handling! */ write_lock_irq(&tasklist_lock); /* * The task hasn't been attached yet, so its cpus_allowed mask will * not be changed, nor will its assigned CPU. * * The cpus_allowed mask of the parent may have changed after it was * copied first time - so re-copy it here, then check the child's CPU * to ensure it is on a valid CPU (and if not, just force it back to * parent's CPU). This avoids alot of nasty races. */ p->cpus_allowed = current->cpus_allowed; if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || !cpu_online(task_cpu(p)))) set_task_cpu(p, smp_processor_id()); /* * Check for pending SIGKILL! The new thread should not be allowed * to slip out of an OOM kill. (or normal SIGKILL.) */ if (sigismember(¤t->pending.signal, SIGKILL)) { write_unlock_irq(&tasklist_lock); retval = -EINTR; #if 1 /* put here by ltt patch */ goto bad_fork_cleanup_ltt_facilities; #else goto bad_fork_cleanup_namespace; #endif } /* CLONE_PARENT re-uses the old parent */ if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) p->real_parent = current->real_parent; else p->real_parent = current; p->parent = p->real_parent; if (clone_flags & CLONE_THREAD) { spin_lock(¤t->sighand->siglock); /* * Important: if an exit-all has been started then * do not create this new thread - the whole thread * group is supposed to exit anyway. */ if (current->signal->flags & SIGNAL_GROUP_EXIT) { spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); retval = -EAGAIN; goto bad_fork_cleanup_ltt_facilities; } p->group_leader = current->group_leader; if (current->signal->group_stop_count > 0) { /* * There is an all-stop in progress for the group. * We ourselves will stop as soon as we check signals. * Make the new thread part of that group stop too. */ current->signal->group_stop_count++; set_tsk_thread_flag(p, TIF_SIGPENDING); } if (!cputime_eq(current->signal->it_virt_expires, cputime_zero) || !cputime_eq(current->signal->it_prof_expires, cputime_zero) || current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY || !list_empty(¤t->signal->cpu_timers[0]) || !list_empty(¤t->signal->cpu_timers[1]) || !list_empty(¤t->signal->cpu_timers[2])) { /* * Have child wake up on its first tick to check * for process CPU timers. */ p->it_prof_expires = jiffies_to_cputime(1); } spin_unlock(¤t->sighand->siglock); } /* * inherit ioprio */ p->ioprio = current->ioprio; SET_LINKS(p); if (unlikely(p->ptrace & PT_PTRACED)) __ptrace_link(p, current->parent); cpuset_fork(p); attach_pid(p, PIDTYPE_PID, p->pid); attach_pid(p, PIDTYPE_TGID, p->tgid); if (thread_group_leader(p)) { attach_pid(p, PIDTYPE_PGID, process_group(p)); attach_pid(p, PIDTYPE_SID, p->signal->session); if (p->pid) __get_cpu_var(process_counts)++; } if (!current->signal->tty && p->signal->tty) p->signal->tty = NULL; nr_threads++; total_forks++; write_unlock_irq(&tasklist_lock); retval = 0; fork_out: if (retval) return ERR_PTR(retval); return p; bad_fork_cleanup_ltt_facilities: #ifdef CONFIG_LTT_USERSPACE_GENERIC { int i; for(i=0; i<LTT_FAC_PER_PROCESS; i++) { if(p->ltt_facilities[i] == 0) break; WARN_ON(ltt_facility_unregister( p->ltt_facilities[i])); } } #endif //CONFIG_LTT_USERSPACE_GENERIC bad_fork_cleanup_namespace: exit_namespace(p); bad_fork_cleanup_keys: exit_keys(p); bad_fork_cleanup_mm: if (p->mm) mmput(p->mm); bad_fork_cleanup_signal: exit_signal(p); bad_fork_cleanup_sighand: exit_sighand(p); bad_fork_cleanup_fs: exit_fs(p); /* blocking */ bad_fork_cleanup_files: exit_files(p); /* blocking */ bad_fork_cleanup_semundo: exit_sem(p); bad_fork_cleanup_audit: audit_free(p); bad_fork_cleanup_security: security_task_free(p); bad_fork_cleanup_policy: #ifdef CONFIG_NUMA mpol_free(p->mempolicy); #endif bad_fork_cleanup: if (p->binfmt) module_put(p->binfmt->module); bad_fork_cleanup_put_domain: module_put(p->thread_info->exec_domain->module); bad_fork_cleanup_count: put_group_info(p->group_info); atomic_dec(&p->user->processes); free_uid(p->user); bad_fork_free: free_task(p); goto fork_out; }
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) { struct task_struct *tsk = current; struct hrtimer *timer; ktime_t expires; cputime_t cval, cinterval, nval, ninterval; /* * Validate the timevals in value. */ if (!timeval_valid(&value->it_value) || !timeval_valid(&value->it_interval)) return -EINVAL; switch (which) { case ITIMER_REAL: again: spin_lock_irq(&tsk->sighand->siglock); timer = &tsk->signal->real_timer; if (ovalue) { ovalue->it_value = itimer_get_remtime(timer); ovalue->it_interval = ktime_to_timeval(tsk->signal->it_real_incr); } /* We are sharing ->siglock with it_real_fn() */ if (hrtimer_try_to_cancel(timer) < 0) { spin_unlock_irq(&tsk->sighand->siglock); hrtimer_wait_for_timer(&tsk->signal->real_timer); goto again; } expires = timeval_to_ktime(value->it_value); if (expires.tv64 != 0) { tsk->signal->it_real_incr = timeval_to_ktime(value->it_interval); hrtimer_start(timer, expires, HRTIMER_MODE_REL); } else tsk->signal->it_real_incr.tv64 = 0; spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) nval = cputime_add(nval, jiffies_to_cputime(1)); set_process_cpu_timer(tsk, CPUCLOCK_VIRT, &nval, &cval); } tsk->signal->it_virt_expires = nval; tsk->signal->it_virt_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); } break; case ITIMER_PROF: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) nval = cputime_add(nval, jiffies_to_cputime(1)); set_process_cpu_timer(tsk, CPUCLOCK_PROF, &nval, &cval); } tsk->signal->it_prof_expires = nval; tsk->signal->it_prof_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); } break; default: return -EINVAL; } return 0; }
int do_getitimer(int which, struct itimerval *value) { struct task_struct *tsk = current; cputime_t cinterval, cval; switch (which) { case ITIMER_REAL: spin_lock_irq(&tsk->sighand->siglock); value->it_value = itimer_get_remtime(&tsk->signal->real_timer); value->it_interval = ktime_to_timeval(tsk->signal->it_real_incr); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; if (!cputime_eq(cval, cputime_zero)) { struct task_struct *t = tsk; cputime_t utime = tsk->signal->utime; do { utime = cputime_add(utime, t->utime); t = next_thread(t); } while (t != tsk); if (cputime_le(cval, utime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { cval = cputime_sub(cval, utime); } } spin_unlock_irq(&tsk->sighand->siglock); read_unlock(&tasklist_lock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; case ITIMER_PROF: read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; if (!cputime_eq(cval, cputime_zero)) { struct task_struct *t = tsk; cputime_t ptime = cputime_add(tsk->signal->utime, tsk->signal->stime); do { ptime = cputime_add(ptime, cputime_add(t->utime, t->stime)); t = next_thread(t); } while (t != tsk); if (cputime_le(cval, ptime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { cval = cputime_sub(cval, ptime); } } spin_unlock_irq(&tsk->sighand->siglock); read_unlock(&tasklist_lock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; default: return(-EINVAL); } return 0; }
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) { struct task_struct *tsk = current; struct hrtimer *timer; ktime_t expires; cputime_t cval, cinterval, nval, ninterval; /* * Validate the timevals in value. * * Note: Although the spec requires that invalid values shall * return -EINVAL, we just fixup the value and print a limited * number of warnings in order not to break users of this * historical misfeature. * * Scheduled for replacement in March 2007 */ check_itimerval(value); switch (which) { case ITIMER_REAL: again: spin_lock_irq(&tsk->sighand->siglock); timer = &tsk->signal->real_timer; if (ovalue) { ovalue->it_value = itimer_get_remtime(timer); ovalue->it_interval = ktime_to_timeval(tsk->signal->it_real_incr); } /* We are sharing ->siglock with it_real_fn() */ if (hrtimer_try_to_cancel(timer) < 0) { spin_unlock_irq(&tsk->sighand->siglock); goto again; } tsk->signal->it_real_incr = timeval_to_ktime(value->it_interval); expires = timeval_to_ktime(value->it_value); if (expires.tv64 != 0) hrtimer_start(timer, expires, HRTIMER_REL); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) nval = cputime_add(nval, jiffies_to_cputime(1)); set_process_cpu_timer(tsk, CPUCLOCK_VIRT, &nval, &cval); } tsk->signal->it_virt_expires = nval; tsk->signal->it_virt_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); read_unlock(&tasklist_lock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); } break; case ITIMER_PROF: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) nval = cputime_add(nval, jiffies_to_cputime(1)); set_process_cpu_timer(tsk, CPUCLOCK_PROF, &nval, &cval); } tsk->signal->it_prof_expires = nval; tsk->signal->it_prof_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); read_unlock(&tasklist_lock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); } break; default: return -EINVAL; } return 0; }
void tick_nohz_restart_sched_tick(void) #endif { int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); #ifndef CONFIG_VIRT_CPU_ACCOUNTING unsigned long ticks; #endif ktime_t now; local_irq_disable(); if (ts->idle_active || (ts->inidle && ts->tick_stopped)) now = ktime_get(); if (ts->idle_active) tick_nohz_stop_idle(cpu, now); if (!ts->inidle || !ts->tick_stopped) { ts->inidle = 0; #ifdef CONFIG_DATAPLANE if (!user_idle) #endif local_irq_enable(); return; } ts->inidle = 0; rcu_exit_nohz(); /* Update jiffies first */ select_nohz_load_balancer(0); tick_do_update_jiffies64(now); cpumask_clear_cpu(cpu, nohz_cpu_mask); #ifndef CONFIG_VIRT_CPU_ACCOUNTING /* * We stopped the tick in idle. Update process times would miss the * time we slept as update_process_times does only a 1 tick * accounting. Enforce that this is accounted to idle ! */ ticks = jiffies - ts->idle_jiffies; /* * We might be one off. Do not randomly account a huge number of ticks! */ if (ticks && ticks < LONG_MAX) #ifdef CONFIG_DATAPLANE { if (user_idle) { cputime_t cpu_time = jiffies_to_cputime(ticks); account_user_time(current, cpu_time, cputime_to_scaled(cpu_time)); } else { account_idle_ticks(ticks); } } #else account_idle_ticks(ticks); #endif #endif touch_softlockup_watchdog(); /* * Cancel the scheduled timer and restore the tick */ ts->tick_stopped = 0; ts->idle_exittime = now; tick_nohz_restart(ts, now); #ifdef CONFIG_DATAPLANE if (!user_idle) #endif local_irq_enable(); }