From bc2c53e5f1a2bae69ae50ce3a592633da7fcf6d9 Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Thu, 19 May 2016 17:09:02 -0700 Subject: time: add missing implementation for timespec64_add_safe() timespec64_add_safe() has been defined in time64.h for 64 bit systems. But, 32 bit systems only have an extern function prototype defined. Provide a definition for the above function. The function will be necessary as part of y2038 changes. struct timespec is not y2038 safe. All references to timespec will be replaced by struct timespec64. The function is meant to be a replacement for timespec_add_safe(). The implementation is similar to timespec_add_safe(). Link: http://lkml.kernel.org/r/1461947989-21926-2-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani Acked-by: John Stultz Cc: Thomas Gleixner Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/time/time.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'kernel/time/time.c') diff --git a/kernel/time/time.c b/kernel/time/time.c index a4064b612066..cb1f83eb5599 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -769,3 +769,28 @@ struct timespec timespec_add_safe(const struct timespec lhs, return res; } + +#if __BITS_PER_LONG != 64 + +/* + * Add two timespec64 values and do a safety check for overflow. + * It's assumed that both values are valid (>= 0). + * And, each timespec64 is in normalized form. + */ +struct timespec64 timespec64_add_safe(const struct timespec64 lhs, + const struct timespec64 rhs) +{ + struct timespec64 res; + + set_normalized_timespec64(&res, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + + if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { + res.tv_sec = TIME64_MAX; + res.tv_nsec = 0; + } + + return res; +} + +#endif -- cgit v1.2.3-59-g8ed1b