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-rw-r--r--kernel/posix-cpu-timers.c64
1 files changed, 30 insertions, 34 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e6389f915bcb..03c5d6c3e614 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -260,30 +260,43 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
return 0;
}
+static int posix_cpu_clock_get_task(struct task_struct *tsk,
+ const clockid_t which_clock,
+ struct timespec *tp)
+{
+ int err = -EINVAL;
+ unsigned long long rtn;
+
+ if (CPUCLOCK_PERTHREAD(which_clock)) {
+ if (same_thread_group(tsk, current))
+ err = cpu_clock_sample(which_clock, tsk, &rtn);
+ } else {
+ read_lock(&tasklist_lock);
+
+ if (tsk->sighand && (tsk == current || thread_group_leader(tsk)))
+ err = cpu_clock_sample_group(which_clock, tsk, &rtn);
+
+ read_unlock(&tasklist_lock);
+ }
+
+ if (!err)
+ sample_to_timespec(which_clock, rtn, tp);
+
+ return err;
+}
+
static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
{
const pid_t pid = CPUCLOCK_PID(which_clock);
- int error = -EINVAL;
- unsigned long long rtn;
+ int err = -EINVAL;
if (pid == 0) {
/*
* Special case constant value for our own clocks.
* We don't have to do any lookup to find ourselves.
*/
- if (CPUCLOCK_PERTHREAD(which_clock)) {
- /*
- * Sampling just ourselves we can do with no locking.
- */
- error = cpu_clock_sample(which_clock,
- current, &rtn);
- } else {
- read_lock(&tasklist_lock);
- error = cpu_clock_sample_group(which_clock,
- current, &rtn);
- read_unlock(&tasklist_lock);
- }
+ err = posix_cpu_clock_get_task(current, which_clock, tp);
} else {
/*
* Find the given PID, and validate that the caller
@@ -292,29 +305,12 @@ static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
struct task_struct *p;
rcu_read_lock();
p = find_task_by_vpid(pid);
- if (p) {
- if (CPUCLOCK_PERTHREAD(which_clock)) {
- if (same_thread_group(p, current)) {
- error = cpu_clock_sample(which_clock,
- p, &rtn);
- }
- } else {
- read_lock(&tasklist_lock);
- if (thread_group_leader(p) && p->sighand) {
- error =
- cpu_clock_sample_group(which_clock,
- p, &rtn);
- }
- read_unlock(&tasklist_lock);
- }
- }
+ if (p)
+ err = posix_cpu_clock_get_task(p, which_clock, tp);
rcu_read_unlock();
}
- if (error)
- return error;
- sample_to_timespec(which_clock, rtn, tp);
- return 0;
+ return err;
}