[RFC PATCH 0/2] add ktime_sub_safe() to avoid undefined behaviour

[Hongbo Yao]

When I ran Syzkaller testsuite, I got some UBSAN warnings with
ktime_sub().

Instead of putting overflow checks into each place, add a function
which does the sanity checking and convert all affected callers to use
it.

Hongbo Yao (2):
  ktime: add ktime_sub_safe() to avoid undefined behaviour
  hrtimer: Prevent overflow for relative refrences

 include/linux/ktime.h |  8 ++++++++
 kernel/time/hrtimer.c | 21 +++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

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2.20.1