1 files changed, 86 insertions, 78 deletions

diff --git a/kernel/itimer.c b/kernel/itimer.c
index 58762f7077ec..8078a32d3b10 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -41,10 +41,43 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
         return ktime_to_timeval(rem);
 }
 
+static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+                           struct itimerval *const value)
+{
+        cputime_t cval, cinterval;
+        struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+        spin_lock_irq(&tsk->sighand->siglock);
+
+        cval = it->expires;
+        cinterval = it->incr;
+        if (!cputime_eq(cval, cputime_zero)) {
+                struct task_cputime cputime;
+                cputime_t t;
+
+                thread_group_cputimer(tsk, &cputime);
+                if (clock_id == CPUCLOCK_PROF)
+                        t = cputime_add(cputime.utime, cputime.stime);
+                else
+                        /* CPUCLOCK_VIRT */
+                        t = cputime.utime;
+
+                if (cputime_le(cval, t))
+                        /* about to fire */
+                        cval = cputime_one_jiffy;
+                else
+                        cval = cputime_sub(cval, t);
+        }
+
+        spin_unlock_irq(&tsk->sighand->siglock);
+
+        cputime_to_timeval(cval, &value->it_value);
+        cputime_to_timeval(cinterval, &value->it_interval);
+}
+
 int do_getitimer(int which, struct itimerval *value)
 {
         struct task_struct *tsk = current;
-        cputime_t cinterval, cval;
 
         switch (which) {
         case ITIMER_REAL:
@@ -55,44 +88,10 @@ int do_getitimer(int which, struct itimerval *value)
                 spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_virt_expires;
-                cinterval = tsk->signal->it_virt_incr;
-                if (!cputime_eq(cval, cputime_zero)) {
-                        struct task_cputime cputime;
-                        cputime_t utime;
-
-                        thread_group_cputimer(tsk, &cputime);
-                        utime = cputime.utime;
-                        if (cputime_le(cval, utime)) { /* about to fire */
-                                cval = jiffies_to_cputime(1);
-                        } else {
-                                cval = cputime_sub(cval, utime);
-                        }
-                }
-                spin_unlock_irq(&tsk->sighand->siglock);
-                cputime_to_timeval(cval, &value->it_value);
-                cputime_to_timeval(cinterval, &value->it_interval);
+                get_cpu_itimer(tsk, CPUCLOCK_VIRT, value);
                 break;
         case ITIMER_PROF:
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_prof_expires;
-                cinterval = tsk->signal->it_prof_incr;
-                if (!cputime_eq(cval, cputime_zero)) {
-                        struct task_cputime times;
-                        cputime_t ptime;
-
-                        thread_group_cputimer(tsk, &times);
-                        ptime = cputime_add(times.utime, times.stime);
-                        if (cputime_le(cval, ptime)) { /* about to fire */
-                                cval = jiffies_to_cputime(1);
-                        } else {
-                                cval = cputime_sub(cval, ptime);
-                        }
-                }
-                spin_unlock_irq(&tsk->sighand->siglock);
-                cputime_to_timeval(cval, &value->it_value);
-                cputime_to_timeval(cinterval, &value->it_interval);
+                get_cpu_itimer(tsk, CPUCLOCK_PROF, value);
                 break;
         default:
                 return(-EINVAL);
@@ -128,6 +127,54 @@ 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,
+                           const struct itimerval *const value,
+                           struct itimerval *const ovalue)
+{
+        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);
+
+        cval = it->expires;
+        cinterval = it->incr;
+        if (!cputime_eq(cval, cputime_zero) ||
+            !cputime_eq(nval, cputime_zero)) {
+                if (cputime_gt(nval, cputime_zero))
+                        nval = cputime_add(nval, cputime_one_jiffy);
+                set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+        }
+        it->expires = nval;
+        it->incr = ninterval;
+
+        spin_unlock_irq(&tsk->sighand->siglock);
+
+        if (ovalue) {
+                cputime_to_timeval(cval, &ovalue->it_value);
+                cputime_to_timeval(cinterval, &ovalue->it_interval);
+        }
+}
+
 /*
  * Returns true if the timeval is in canonical form
  */
@@ -139,7 +186,6 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
         struct task_struct *tsk = current;
         struct hrtimer *timer;
         ktime_t expires;
-        cputime_t cval, cinterval, nval, ninterval;
 
         /*
          * Validate the timevals in value.
@@ -174,48 +220,10 @@ again:
                 spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
-                nval = timeval_to_cputime(&value->it_value);
-                ninterval = timeval_to_cputime(&value->it_interval);
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_virt_expires;
-                cinterval = tsk->signal->it_virt_incr;
-                if (!cputime_eq(cval, cputime_zero) ||
-                    !cputime_eq(nval, cputime_zero)) {
-                        if (cputime_gt(nval, cputime_zero))
-                                nval = cputime_add(nval,
-                                                   jiffies_to_cputime(1));
-                        set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
-                                              &nval, &cval);
-                }
-                tsk->signal->it_virt_expires = nval;
-                tsk->signal->it_virt_incr = ninterval;
-                spin_unlock_irq(&tsk->sighand->siglock);
-                if (ovalue) {
-                        cputime_to_timeval(cval, &ovalue->it_value);
-                        cputime_to_timeval(cinterval, &ovalue->it_interval);
-                }
+                set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue);
                 break;
         case ITIMER_PROF:
-                nval = timeval_to_cputime(&value->it_value);
-                ninterval = timeval_to_cputime(&value->it_interval);
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_prof_expires;
-                cinterval = tsk->signal->it_prof_incr;
-                if (!cputime_eq(cval, cputime_zero) ||
-                    !cputime_eq(nval, cputime_zero)) {
-                        if (cputime_gt(nval, cputime_zero))
-                                nval = cputime_add(nval,
-                                                   jiffies_to_cputime(1));
-                        set_process_cpu_timer(tsk, CPUCLOCK_PROF,
-                                              &nval, &cval);
-                }
-                tsk->signal->it_prof_expires = nval;
-                tsk->signal->it_prof_incr = ninterval;
-                spin_unlock_irq(&tsk->sighand->siglock);
-                if (ovalue) {
-                        cputime_to_timeval(cval, &ovalue->it_value);
-                        cputime_to_timeval(cinterval, &ovalue->it_interval);
-                }
+                set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue);
                 break;
         default:
                 return -EINVAL;