Commit 4312e0e8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

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
parents 82423b46 cb477557

include/linux/time64.h

+4 −0
Original line number Diff line number Diff line
@@ -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;

}

kernel/time/hrtimer.c

+0 −5
Original line number Diff line number Diff line
@@ -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);

kernel/time/itimer.c

+0 −4
Original line number Diff line number Diff line
@@ -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);

kernel/time/sched_clock.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

}

kernel/time/timer.c

+0 −5
Original line number Diff line number Diff line
@@ -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);

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