Re: [patch 2/6] timekeeping: Make the conversion call chain consistently unsigned

From: David Gibson
Date: Thu Dec 08 2016 - 18:47:51 EST


On Thu, Dec 08, 2016 at 08:49:34PM -0000, Thomas Gleixner wrote:
> Propagating a unsigned value through signed variables and functions makes
> absolutely no sense and is just prone to (re)introduce subtle signed
> vs. unsigned issues as happened recently.
>
> Clean it up.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>

> ---
> kernel/time/timekeeping.c | 26 +++++++++++++-------------
> 1 file changed, 13 insertions(+), 13 deletions(-)
>
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -311,7 +311,7 @@ static inline u64 timekeeping_delta_to_n
> return nsec + arch_gettimeoffset();
> }
>
> -static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
> +static inline u64 timekeeping_get_ns(struct tk_read_base *tkr)
> {
> cycle_t delta;
>
> @@ -319,8 +319,8 @@ static inline s64 timekeeping_get_ns(str
> return timekeeping_delta_to_ns(tkr, delta);
> }
>
> -static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
> - cycle_t cycles)
> +static inline u64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
> + cycle_t cycles)
> {
> cycle_t delta;
>
> @@ -623,7 +623,7 @@ static void timekeeping_forward_now(stru
> {
> struct clocksource *clock = tk->tkr_mono.clock;
> cycle_t cycle_now, delta;
> - s64 nsec;
> + u64 nsec;
>
> cycle_now = tk->tkr_mono.read(clock);
> delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
> @@ -652,7 +652,7 @@ int __getnstimeofday64(struct timespec64
> {
> struct timekeeper *tk = &tk_core.timekeeper;
> unsigned long seq;
> - s64 nsecs = 0;
> + u64 nsecs;
>
> do {
> seq = read_seqcount_begin(&tk_core.seq);
> @@ -692,7 +692,7 @@ ktime_t ktime_get(void)
> struct timekeeper *tk = &tk_core.timekeeper;
> unsigned int seq;
> ktime_t base;
> - s64 nsecs;
> + u64 nsecs;
>
> WARN_ON(timekeeping_suspended);
>
> @@ -735,7 +735,7 @@ ktime_t ktime_get_with_offset(enum tk_of
> struct timekeeper *tk = &tk_core.timekeeper;
> unsigned int seq;
> ktime_t base, *offset = offsets[offs];
> - s64 nsecs;
> + u64 nsecs;
>
> WARN_ON(timekeeping_suspended);
>
> @@ -779,7 +779,7 @@ ktime_t ktime_get_raw(void)
> struct timekeeper *tk = &tk_core.timekeeper;
> unsigned int seq;
> ktime_t base;
> - s64 nsecs;
> + u64 nsecs;
>
> do {
> seq = read_seqcount_begin(&tk_core.seq);
> @@ -804,8 +804,8 @@ void ktime_get_ts64(struct timespec64 *t
> {
> struct timekeeper *tk = &tk_core.timekeeper;
> struct timespec64 tomono;
> - s64 nsec;
> unsigned int seq;
> + u64 nsec;
>
> WARN_ON(timekeeping_suspended);
>
> @@ -893,8 +893,8 @@ void ktime_get_snapshot(struct system_ti
> unsigned long seq;
> ktime_t base_raw;
> ktime_t base_real;
> - s64 nsec_raw;
> - s64 nsec_real;
> + u64 nsec_raw;
> + u64 nsec_real;
> cycle_t now;
>
> WARN_ON_ONCE(timekeeping_suspended);
> @@ -1052,7 +1052,7 @@ int get_device_system_crosststamp(int (*
> cycle_t cycles, now, interval_start;
> unsigned int clock_was_set_seq = 0;
> ktime_t base_real, base_raw;
> - s64 nsec_real, nsec_raw;
> + u64 nsec_real, nsec_raw;
> u8 cs_was_changed_seq;
> unsigned long seq;
> bool do_interp;
> @@ -1365,7 +1365,7 @@ void getrawmonotonic64(struct timespec64
> struct timekeeper *tk = &tk_core.timekeeper;
> struct timespec64 ts64;
> unsigned long seq;
> - s64 nsecs;
> + u64 nsecs;
>
> do {
> seq = read_seqcount_begin(&tk_core.seq);
>
>

--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson

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