1 files changed, 64 insertions, 40 deletions

diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 8c89143f9ebf..2ef98a02376a 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -10,9 +10,12 @@
 #include <linux/interrupt.h>
 #include <linux/syscalls.h>
 #include <linux/time.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/cputime.h>
 #include <linux/posix-timers.h>
 #include <linux/hrtimer.h>
 #include <trace/events/timer.h>
+#include <linux/compat.h>
 
 #include <linux/uaccess.h>
 
@@ -45,16 +48,16 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
 static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 			   struct itimerval *const value)
 {
-	cputime_t cval, cinterval;
+	u64 val, interval;
 	struct cpu_itimer *it = &tsk->signal->it[clock_id];
 
 	spin_lock_irq(&tsk->sighand->siglock);
 
-	cval = it->expires;
-	cinterval = it->incr;
-	if (cval) {
+	val = it->expires;
+	interval = it->incr;
+	if (val) {
 		struct task_cputime cputime;
-		cputime_t t;
+		u64 t;
 
 		thread_group_cputimer(tsk, &cputime);
 		if (clock_id == CPUCLOCK_PROF)
@@ -63,17 +66,17 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 			/* CPUCLOCK_VIRT */
 			t = cputime.utime;
 
-		if (cval < t)
+		if (val < t)
 			/* about to fire */
-			cval = cputime_one_jiffy;
+			val = TICK_NSEC;
 		else
-			cval = cval - t;
+			val -= t;
 	}
 
 	spin_unlock_irq(&tsk->sighand->siglock);
 
-	cputime_to_timeval(cval, &value->it_value);
-	cputime_to_timeval(cinterval, &value->it_interval);
+	value->it_value = ns_to_timeval(val);
+	value->it_interval = ns_to_timeval(interval);
 }
 
 int do_getitimer(int which, struct itimerval *value)
@@ -114,6 +117,19 @@ SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
 	return error;
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
+		       struct compat_itimerval __user *, it)
+{
+	struct itimerval kit;
+	int error = do_getitimer(which, &kit);
+
+	if (!error && put_compat_itimerval(it, &kit))
+		error = -EFAULT;
+	return error;
+}
+#endif
+
 
 /*
  * The timer is automagically restarted, when interval != 0
@@ -129,55 +145,39 @@ 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;
-	u32 error, incr_error;
+	u64 oval, nval, ointerval, ninterval;
 	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);
-
-	error = cputime_sub_ns(nval, ns_nval);
-	incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+	/*
+	 * Use the to_ktime conversion because that clamps the maximum
+	 * value to KTIME_MAX and avoid multiplication overflows.
+	 */
+	nval = ktime_to_ns(timeval_to_ktime(value->it_value));
+	ninterval = ktime_to_ns(timeval_to_ktime(value->it_interval));
 
 	spin_lock_irq(&tsk->sighand->siglock);
 
-	cval = it->expires;
-	cinterval = it->incr;
-	if (cval || nval) {
+	oval = it->expires;
+	ointerval = it->incr;
+	if (oval || nval) {
 		if (nval > 0)
-			nval += cputime_one_jiffy;
-		set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+			nval += TICK_NSEC;
+		set_process_cpu_timer(tsk, clock_id, &nval, &oval);
 	}
 	it->expires = nval;
 	it->incr = ninterval;
-	it->error = error;
-	it->incr_error = incr_error;
 	trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
 			   ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
 
 	spin_unlock_irq(&tsk->sighand->siglock);
 
 	if (ovalue) {
-		cputime_to_timeval(cval, &ovalue->it_value);
-		cputime_to_timeval(cinterval, &ovalue->it_interval);
+		ovalue->it_value = ns_to_timeval(oval);
+		ovalue->it_interval = ns_to_timeval(ointerval);
 	}
 }
 
@@ -312,3 +312,27 @@ SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
 		return -EFAULT;
 	return 0;
 }
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
+		       struct compat_itimerval __user *, in,
+		       struct compat_itimerval __user *, out)
+{
+	struct itimerval kin, kout;
+	int error;
+
+	if (in) {
+		if (get_compat_itimerval(&kin, in))
+			return -EFAULT;
+	} else {
+		memset(&kin, 0, sizeof(kin));
+	}
+
+	error = do_setitimer(which, &kin, out ? &kout : NULL);
+	if (error || !out)
+		return error;
+	if (put_compat_itimerval(out, &kout))
+		return -EFAULT;
+	return 0;
+}
+#endif