posix-cpu-timers: Use common permission check in posix_cpu_timer_create()

Yet another copy of the same thing gone...

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.505833418@linutronix.de

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index eb11117..4426a0f 100644 (file)
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -316,44 +316,15 @@ static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp)
  */
 static int posix_cpu_timer_create(struct k_itimer *new_timer)
 {
-       int ret = 0;
-       const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
-       struct task_struct *p;
+       struct task_struct *p = get_task_for_clock(new_timer->it_clock);
 
-       if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
+       if (!p)
                return -EINVAL;
 
        new_timer->kclock = &clock_posix_cpu;
-
        INIT_LIST_HEAD(&new_timer->it.cpu.entry);
-
-       rcu_read_lock();
-       if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
-               if (pid == 0) {
-                       p = current;
-               } else {
-                       p = find_task_by_vpid(pid);
-                       if (p && !same_thread_group(p, current))
-                               p = NULL;
-               }
-       } else {
-               if (pid == 0) {
-                       p = current->group_leader;
-               } else {
-                       p = find_task_by_vpid(pid);
-                       if (p && !has_group_leader_pid(p))
-                               p = NULL;
-               }
-       }
        new_timer->it.cpu.task = p;
-       if (p) {
-               get_task_struct(p);
-       } else {
-               ret = -EINVAL;
-       }
-       rcu_read_unlock();
-
-       return ret;
+       return 0;
 }
 
 /*