+#include <linux/kernel_stat.h>
+
+/*
+ * Allocate the thread_group_cputime structure appropriately and fill in the
+ * current values of the fields. Called from copy_signal() via
+ * thread_group_cputime_clone_thread() when adding a second or subsequent
+ * thread to a thread group. Assumes interrupts are enabled when called.
+ */
+int thread_group_cputime_alloc(struct task_struct *tsk)
+{
+ struct signal_struct *sig = tsk->signal;
+ struct task_cputime *cputime;
+
+ /*
+ * If we have multiple threads and we don't already have a
+ * per-CPU task_cputime struct (checked in the caller), allocate
+ * one and fill it in with the times accumulated so far. We may
+ * race with another thread so recheck after we pick up the sighand
+ * lock.
+ */
+ cputime = alloc_percpu(struct task_cputime);
+ if (cputime == NULL)
+ return -ENOMEM;
+ spin_lock_irq(&tsk->sighand->siglock);
+ if (sig->cputime.totals) {
+ spin_unlock_irq(&tsk->sighand->siglock);
+ free_percpu(cputime);
+ return 0;
+ }
+ sig->cputime.totals = cputime;
+ cputime = per_cpu_ptr(sig->cputime.totals, smp_processor_id());
+ cputime->utime = tsk->utime;
+ cputime->stime = tsk->stime;
+ cputime->sum_exec_runtime = tsk->se.sum_exec_runtime;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ return 0;
+}
+
+/**
+ * thread_group_cputime - Sum the thread group time fields across all CPUs.
+ *
+ * @tsk: The task we use to identify the thread group.
+ * @times: task_cputime structure in which we return the summed fields.
+ *
+ * Walk the list of CPUs to sum the per-CPU time fields in the thread group
+ * time structure.
+ */
+void thread_group_cputime(
+ struct task_struct *tsk,
+ struct task_cputime *times)
+{
+ struct signal_struct *sig;
+ int i;
+ struct task_cputime *tot;
+
+ sig = tsk->signal;
+ if (unlikely(!sig) || !sig->cputime.totals) {
+ times->utime = tsk->utime;
+ times->stime = tsk->stime;
+ times->sum_exec_runtime = tsk->se.sum_exec_runtime;
+ return;
+ }
+ times->stime = times->utime = cputime_zero;
+ times->sum_exec_runtime = 0;
+ for_each_possible_cpu(i) {
+ tot = per_cpu_ptr(tsk->signal->cputime.totals, i);
+ times->utime = cputime_add(times->utime, tot->utime);
+ times->stime = cputime_add(times->stime, tot->stime);
+ times->sum_exec_runtime += tot->sum_exec_runtime;
+ }
+}
+
+/*
+ * 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_lt(current->signal->it_prof_expires, cputime)) {
+ spin_lock_irq(¤t->sighand->siglock);
+ set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
+ spin_unlock_irq(¤t->sighand->siglock);
+ }
+}