How to solve undefined reference to `__umoddi3'

Problem faced:

kernel/built-in.o: In function `getnstimeofday':
(.text+0xee36): undefined reference to `__umoddi3'
kernel/built-in.o: In function `do_gettimeofday':
(.text+0xeee1): undefined reference to `__udivdi3'
kernel/built-in.o: In function `do_gettimeofday':
(.text+0xeefe): undefined reference to `__umoddi3'
kernel/built-in.o: In function `do_timer':
(.text+0xfd88): undefined reference to `__udivdi3'
kernel/built-in.o: In function `do_timer':
(.text+0xfda5): undefined reference to `__umoddi3'
make: *** [.tmp_vmlinux1] Error 1

Solution:

---
 include/linux/time.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/linux/time.h b/include/linux/time.h
index 2091a19..d32ef0a 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -174,6 +174,10 @@ static inline void timespec_add_ns(struct timespec *a, u64 ns)
 {
  ns += a->tv_nsec;
  while(unlikely(ns >= NSEC_PER_SEC)) {
+  /* The following asm() prevents the compiler from
+   * optimising this loop into a modulo operation.  */
+  asm("" : "+r"(ns));       // Include this line in the file /include/linux/time.h
+
   ns -= NSEC_PER_SEC;
   a->tv_sec++;
  }
-- 

This patch prevents gcc form "optimizing" the while loop into a costly modulo.
operation