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Diffstat (limited to 'kernel/itimer.c')
-rw-r--r--kernel/itimer.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 852c88ddd1f0..21adff7b2a17 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -42,7 +42,7 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
}
static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
- struct itimerval *value)
+ struct itimerval *const value)
{
cputime_t cval, cinterval;
struct cpu_itimer *it = &tsk->signal->it[clock_id];
@@ -127,14 +127,32 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
+static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
+{
+ struct timespec ts;
+ s64 cpu_ns;
+
+ cputime_to_timespec(ct, &ts);
+ cpu_ns = timespec_to_ns(&ts);
+
+ return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
+}
+
static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
- struct itimerval *value, struct itimerval *ovalue)
+ const struct itimerval *const value,
+ struct itimerval *const ovalue)
{
- cputime_t cval, cinterval, nval, ninterval;
+ cputime_t cval, nval, cinterval, ninterval;
+ s64 ns_ninterval, ns_nval;
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);
+
+ it->incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+ it->error = cputime_sub_ns(nval, ns_nval);
spin_lock_irq(&tsk->sighand->siglock);