Ejemplo n.º 1
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:
        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, &times);
            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;
}
Ejemplo n.º 2
0
static inline void check_for_tasks(int cpu)
{
	struct task_struct *p;

	write_lock_irq(&tasklist_lock);
	for_each_process(p) {
		if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
		    (!cputime_eq(p->utime, cputime_zero) ||
		     !cputime_eq(p->stime, cputime_zero)))
			printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
				"(state = %ld, flags = %x)\n",
				p->comm, task_pid_nr(p), cpu,
				p->state, p->flags);
	}
	write_unlock_irq(&tasklist_lock);
}
Ejemplo n.º 3
0
static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
			   struct itimerval *const value)
{
	cputime_t cval, cinterval;
	struct cpu_itimer *it = &tsk->signal->it[clock_id];

	spin_lock_irq(&tsk->sighand->siglock);

	cval = it->expires;
	cinterval = it->incr;
	if (!cputime_eq(cval, cputime_zero)) {
		struct task_cputime cputime;
		cputime_t t;

		thread_group_cputimer(tsk, &cputime);
		if (clock_id == CPUCLOCK_PROF)
			t = cputime_add(cputime.utime, cputime.stime);
		else
			/* CPUCLOCK_VIRT */
			t = cputime.utime;

		if (cputime_le(cval, t))
			/* about to fire */
			cval = cputime_one_jiffy;
		else
			cval = cputime_sub(cval, t);
	}

	spin_unlock_irq(&tsk->sighand->siglock);

	cputime_to_timeval(cval, &value->it_value);
	cputime_to_timeval(cinterval, &value->it_interval);
}
Ejemplo n.º 4
0
static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
			   const struct itimerval *const value,
			   struct itimerval *const ovalue)
{
	cputime_t cval, nval, cinterval, ninterval;
	s64 ns_ninterval, ns_nval;
	u32 error, incr_error;
	struct cpu_itimer *it = &tsk->signal->it[clock_id];

	nval = timeval_to_cputime(&value->it_value);
	ns_nval = timeval_to_ns(&value->it_value);
	ninterval = timeval_to_cputime(&value->it_interval);
	ns_ninterval = timeval_to_ns(&value->it_interval);

	error = cputime_sub_ns(nval, ns_nval);
	incr_error = cputime_sub_ns(ninterval, ns_ninterval);

	spin_lock_irq(&tsk->sighand->siglock);

	cval = it->expires;
	cinterval = it->incr;
	if (!cputime_eq(cval, cputime_zero) ||
	    !cputime_eq(nval, cputime_zero)) {
		if (cputime_gt(nval, cputime_zero))
			nval = cputime_add(nval, cputime_one_jiffy);
		set_process_cpu_timer(tsk, clock_id, &nval, &cval);
	}
	it->expires = nval;
	it->incr = ninterval;
	it->error = error;
	it->incr_error = incr_error;
	trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
			   ITIMER_VIRTUAL : ITIMER_PROF, value, nval);

	spin_unlock_irq(&tsk->sighand->siglock);

	if (ovalue) {
		cputime_to_timeval(cval, &ovalue->it_value);
		cputime_to_timeval(cinterval, &ovalue->it_interval);
	}
}
Ejemplo n.º 5
0
/*
 * Called after updating RLIMIT_CPU to set timer expiration if necessary.
 */
void update_rlimit_cpu(unsigned long rlim_new)
{
	cputime_t cputime;

	cputime = secs_to_cputime(rlim_new);
	if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
	    cputime_gt(current->signal->it_prof_expires, cputime)) {
		spin_lock_irq(&current->sighand->siglock);
		set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
		spin_unlock_irq(&current->sighand->siglock);
	}
}
Ejemplo n.º 6
0
/*
 * Called after updating RLIMIT_CPU to set timer expiration if necessary.
 */
void update_rlimit_cpu(unsigned long rlim_new)
{
	cputime_t cputime = secs_to_cputime(rlim_new);
	struct signal_struct *const sig = current->signal;

	if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
	    cputime_lt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
		spin_lock_irq(&current->sighand->siglock);
		set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
		spin_unlock_irq(&current->sighand->siglock);
	}
}
Ejemplo n.º 7
0
asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
{
    struct rlimit new_rlim, *old_rlim;
    int retval;

    if (resource >= RLIM_NLIMITS)
        return -EINVAL;
    if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
        return -EFAULT;
    if (new_rlim.rlim_cur > new_rlim.rlim_max)
        return -EINVAL;
    old_rlim = current->signal->rlim + resource;
    if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
            !capable(CAP_SYS_RESOURCE))
        return -EPERM;
    if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
        return -EPERM;

    retval = security_task_setrlimit(resource, &new_rlim);
    if (retval)
        return retval;

    task_lock(current->group_leader);
    *old_rlim = new_rlim;
    task_unlock(current->group_leader);

    if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
            (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
             new_rlim.rlim_cur <= cputime_to_secs(
                 current->signal->it_prof_expires))) {
        cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
        read_lock(&tasklist_lock);
        spin_lock_irq(&current->sighand->siglock);
        set_process_cpu_timer(current, CPUCLOCK_PROF,
                              &cputime, NULL);
        spin_unlock_irq(&current->sighand->siglock);
        read_unlock(&tasklist_lock);
    }

    return 0;
}
Ejemplo n.º 8
0
/*
 * 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(&current->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(&current->sighand->siglock);
		write_unlock_irq(&tasklist_lock);
		retval = -ERESTARTNOINTR;
		goto bad_fork_free_pid;
	}

	if (clone_flags & CLONE_THREAD) {
		atomic_inc(&current->signal->count);
		atomic_inc(&current->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(&current->signal->cpu_timers[0]) ||
		    !list_empty(&current->signal->cpu_timers[1]) ||
		    !list_empty(&current->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(&current->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);
}
Ejemplo n.º 9
0
/*
 * 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(&current->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(&current->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(&current->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(&current->signal->cpu_timers[0]) ||
		    !list_empty(&current->signal->cpu_timers[1]) ||
		    !list_empty(&current->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(&current->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;
}
Ejemplo n.º 10
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.
     */
    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;
}
Ejemplo n.º 11
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;
}
Ejemplo n.º 12
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;
}