Merge tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel...

Pull timer fixes from Thomas Gleixner:
 "A few fixes for timers/timekeeping:

   - Prevent undefined behaviour in the timespec64_to_ns() conversion
     which is used for converting user supplied time input to
     nanoseconds. It lacked overflow protection.

   - Mark sched_clock_read_begin/retry() to prevent recursion in the
     tracer

   - Remove unused debug functions in the hrtimer and timerlist code"

* tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Prevent undefined behaviour in timespec64_to_ns()
  timers: Remove unused inline funtion debug_timer_free()
  hrtimer: Remove unused inline function debug_hrtimer_free()
  time/sched_clock: Mark sched_clock_read_begin/retry() as notrace

diff --git a/include/linux/time64.h b/include/linux/time64.h
index c9dcb3e..5117cb5 100644 (file)
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -124,6 +124,10 @@ static inline bool timespec64_valid_settod(const struct timespec64 *ts)
  */
 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
 {
+       /* Prevent multiplication overflow */
+       if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
+               return KTIME_MAX;
+
        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 }
 

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 3624b9b..387b4be 100644 (file)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -425,11 +425,6 @@ static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
        debug_object_deactivate(timer, &hrtimer_debug_descr);
 }
 
-static inline void debug_hrtimer_free(struct hrtimer *timer)
-{
-       debug_object_free(timer, &hrtimer_debug_descr);
-}
-
 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
                           enum hrtimer_mode mode);
 

diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index ca4e6d5..00629e6 100644 (file)
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -172,10 +172,6 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
        u64 oval, nval, ointerval, ninterval;
        struct cpu_itimer *it = &tsk->signal->it[clock_id];
 
-       /*
-        * Use the to_ktime conversion because that clamps the maximum
-        * value to KTIME_MAX and avoid multiplication overflows.
-        */
        nval = timespec64_to_ns(&value->it_value);
        ninterval = timespec64_to_ns(&value->it_interval);
 

diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index 0642013..b1b9b12 100644 (file)
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -68,13 +68,13 @@ static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift)
        return (cyc * mult) >> shift;
 }
 
-struct clock_read_data *sched_clock_read_begin(unsigned int *seq)
+notrace struct clock_read_data *sched_clock_read_begin(unsigned int *seq)
 {
        *seq = raw_read_seqcount_latch(&cd.seq);
        return cd.read_data + (*seq & 1);
 }
 
-int sched_clock_read_retry(unsigned int seq)
+notrace int sched_clock_read_retry(unsigned int seq)
 {
        return read_seqcount_latch_retry(&cd.seq, seq);
 }

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index de37e33..c3ad64f 100644 (file)
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -732,11 +732,6 @@ static inline void debug_timer_deactivate(struct timer_list *timer)
        debug_object_deactivate(timer, &timer_debug_descr);
 }
 
-static inline void debug_timer_free(struct timer_list *timer)
-{
-       debug_object_free(timer, &timer_debug_descr);
-}
-
 static inline void debug_timer_assert_init(struct timer_list *timer)
 {
        debug_object_assert_init(timer, &timer_debug_descr);