[patch 20/44] posix-cpu-timers: Simplify sample functions

Thomas Gleixner
2019-08-19T15:45:59Z

All callers hand in a valdiated clock id. Remove the return value which was
unchecked in most places anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -180,14 +180,12 @@ posix_cpu_clock_set(const clockid_t cloc
}

/*
- * Sample a per-thread clock for the given task.
+ * Sample a per-thread clock for the given task. clkid is validated.
*/
-static int cpu_clock_sample(const clockid_t which_clock,
- struct task_struct *p, u64 *sample)
+static void cpu_clock_sample(const clockid_t clkid, struct task_struct *p,
+ u64 *sample)
{
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
+ switch (clkid) {
case CPUCLOCK_PROF:
*sample = prof_ticks(p);
break;
@@ -197,8 +195,9 @@ static int cpu_clock_sample(const clocki
case CPUCLOCK_SCHED:
*sample = task_sched_runtime(p);
break;
+ default:
+ WARN_ON_ONCE(1);
}
- return 0;
}

/*
@@ -297,11 +296,11 @@ thread_group_start_cputime(struct task_s
* Sample a process (thread group) clock for the given task clkid. If the
* groups cputime accounting is already enabled, read the atomic
* store. Otherwise a full update is required. task sighand lock must be
- * held to protect the task traversal on a full update.
+ * held to protect the task traversal on a full update. clkid is already
+ * validated.
*/
-static int cpu_clock_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- u64 *sample, bool start)
+static void cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
+ u64 *sample, bool start)
{
struct thread_group_cputimer *cputimer = &p->signal->cputimer;
struct task_cputime cputime;
@@ -315,9 +314,7 @@ static int cpu_clock_sample_group(const
sample_cputime_atomic(&cputime, &cputimer->cputime_atomic);
}

- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
+ switch (clkid) {
case CPUCLOCK_PROF:
*sample = cputime.utime + cputime.stime;
break;
@@ -327,8 +324,9 @@ static int cpu_clock_sample_group(const
case CPUCLOCK_SCHED:
*sample = cputime.sum_exec_runtime;
break;
+ default:
+ WARN_ON_ONCE(1);
}
- return 0;
}

static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp)