timekeeping: Provide y2038 safe accessor to the seconds portion of CLOCK_REALTIME
authorHeena Sirwani <heenasirwani@gmail.com>
Wed, 29 Oct 2014 10:31:50 +0000 (16:01 +0530)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 29 Oct 2014 14:15:40 +0000 (15:15 +0100)
commitdbe7aa622db96b5cd601f59d09c4f00b98b76079
tree303b3f8f88b40b4529f3a37ea20ca8f4f46694e5
parent9e3680b1750b9a62680b0262c9f438de98b77655
timekeeping: Provide y2038 safe accessor to the seconds portion of CLOCK_REALTIME

ktime_get_real_seconds() is the replacement function for get_seconds()
returning the seconds portion of CLOCK_REALTIME in a time64_t. For
64bit the function is equivivalent to get_seconds(), but for 32bit it
protects the readout with the timekeeper sequence count. This is
required because 32-bit machines cannot access 64-bit tk->xtime_sec
variable atomically.

[tglx: Massaged changelog and added docbook comment ]

Signed-off-by: Heena Sirwani <heenasirwani@gmail.com>
Reviewed-by: Arnd Bergman <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: opw-kernel@googlegroups.com
Link: http://lkml.kernel.org/r/7adcfaa8962b8ad58785d9a2456c3f77d93c0ffb.1414578445.git.heenasirwani@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
include/linux/timekeeping.h
kernel/time/timekeeping.c