From e1e41b6ce5f9c1a80bf4f2404ec5ab11c6c5a2ad Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Mon, 18 Mar 2019 20:55:56 +0100 Subject: timekeeping: Consistently use unsigned int for seqcount snapshot The timekeeping code uses a random mix of "unsigned long" and "unsigned int" for the seqcount snapshots (ratio 14:12). Since the seqlock.h API is entirely based on unsigned int, use that throughout. Signed-off-by: Rasmus Villemoes Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: John Stultz Cc: Stephen Boyd Link: https://lkml.kernel.org/r/20190318195557.20773-1-linux@rasmusvillemoes.dk --- kernel/time/timekeeping.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f986e1918d12..540145da33da 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -720,7 +720,7 @@ static void timekeeping_forward_now(struct timekeeper *tk) void ktime_get_real_ts64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; u64 nsecs; WARN_ON(timekeeping_suspended); @@ -829,7 +829,7 @@ EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset); ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) { ktime_t *offset = offsets[offs]; - unsigned long seq; + unsigned int seq; ktime_t tconv; do { @@ -960,7 +960,7 @@ time64_t __ktime_get_real_seconds(void) void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; ktime_t base_raw; ktime_t base_real; u64 nsec_raw; @@ -1122,7 +1122,7 @@ int get_device_system_crosststamp(int (*get_time_fn) ktime_t base_real, base_raw; u64 nsec_real, nsec_raw; u8 cs_was_changed_seq; - unsigned long seq; + unsigned int seq; bool do_interp; int ret; @@ -1409,7 +1409,7 @@ int timekeeping_notify(struct clocksource *clock) void ktime_get_raw_ts64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; u64 nsecs; do { @@ -1431,7 +1431,7 @@ EXPORT_SYMBOL(ktime_get_raw_ts64); int timekeeping_valid_for_hres(void) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; int ret; do { @@ -1450,7 +1450,7 @@ int timekeeping_valid_for_hres(void) u64 timekeeping_max_deferment(void) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; u64 ret; do { @@ -2150,7 +2150,7 @@ EXPORT_SYMBOL_GPL(getboottime64); void ktime_get_coarse_real_ts64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long seq; + unsigned int seq; do { seq = read_seqcount_begin(&tk_core.seq); @@ -2164,7 +2164,7 @@ void ktime_get_coarse_ts64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 now, mono; - unsigned long seq; + unsigned int seq; do { seq = read_seqcount_begin(&tk_core.seq); -- cgit v1.2.3 From 7a8e61f8478639072d402a26789055a4a4de8f77 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 23 Mar 2019 11:36:19 +0100 Subject: timekeeping: Force upper bound for setting CLOCK_REALTIME Several people reported testing failures after setting CLOCK_REALTIME close to the limits of the kernel internal representation in nanoseconds, i.e. year 2262. The failures are exposed in subsequent operations, i.e. when arming timers or when the advancing CLOCK_MONOTONIC makes the calculation of CLOCK_REALTIME overflow into negative space. Now people start to paper over the underlying problem by clamping calculations to the valid range, but that's just wrong because such workarounds will prevent detection of real issues as well. It is reasonable to force an upper bound for the various methods of setting CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum uptime of 30 years which is plenty enough even for esoteric embedded systems. That results in an upper bound of year 2232 for setting the time. Once that limit is reached in reality this limit is only a small part of the problem space. But until then this stops people from trying to paper over the problem at the wrong places. Reported-by: Xiongfeng Wang Reported-by: Hongbo Yao Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Stephen Boyd Cc: Miroslav Lichvar Cc: Arnd Bergmann Cc: Richard Cochran Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903231125480.2157@nanos.tec.linutronix.de --- kernel/time/timekeeping.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 540145da33da..5716e28bfa3c 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1221,7 +1221,7 @@ int do_settimeofday64(const struct timespec64 *ts) unsigned long flags; int ret = 0; - if (!timespec64_valid_strict(ts)) + if (!timespec64_valid_settod(ts)) return -EINVAL; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -1278,7 +1278,7 @@ static int timekeeping_inject_offset(const struct timespec64 *ts) /* Make sure the proposed value is valid */ tmp = timespec64_add(tk_xtime(tk), *ts); if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 || - !timespec64_valid_strict(&tmp)) { + !timespec64_valid_settod(&tmp)) { ret = -EINVAL; goto error; } @@ -1527,7 +1527,7 @@ void __init timekeeping_init(void) unsigned long flags; read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); - if (timespec64_valid_strict(&wall_time) && + if (timespec64_valid_settod(&wall_time) && timespec64_to_ns(&wall_time) > 0) { persistent_clock_exists = true; } else if (timespec64_to_ns(&wall_time) != 0) { -- cgit v1.2.3