Merge tag 'ovl-fixes-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

[linux-2.6-microblaze.git] / include / linux / time64.h

diff --git a/include/linux/time64.h b/include/linux/time64.h
index f38d382..a620ee6 100644 (file)
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -33,6 +33,17 @@ struct itimerspec64 {
 #define KTIME_MAX                      ((s64)~((u64)1 << 63))
 #define KTIME_SEC_MAX                  (KTIME_MAX / NSEC_PER_SEC)
 
+/*
+ * Limits for settimeofday():
+ *
+ * To prevent setting the time close to the wraparound point time setting
+ * is limited so a reasonable uptime can be accomodated. Uptime of 30 years
+ * should be really sufficient, which means the cutoff is 2232. At that
+ * point the cutoff is just a small part of the larger problem.
+ */
+#define TIME_UPTIME_SEC_MAX            (30LL * 365 * 24 *3600)
+#define TIME_SETTOD_SEC_MAX            (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX)
+
 static inline int timespec64_equal(const struct timespec64 *a,
                                   const struct timespec64 *b)
 {
@@ -100,6 +111,16 @@ static inline bool timespec64_valid_strict(const struct timespec64 *ts)
        return true;
 }
 
+static inline bool timespec64_valid_settod(const struct timespec64 *ts)
+{
+       if (!timespec64_valid(ts))
+               return false;
+       /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */
+       if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX)
+               return false;
+       return true;
+}
+
 /**
  * timespec64_to_ns - Convert timespec64 to nanoseconds
  * @ts:                pointer to the timespec64 variable to be converted