Code in kernel which incorrectly used the non-killable variants could
end up having waits killed improperly. The respective killable waits
have been upstream for a while:

  o wait_for_completion_killable()
  o wait_for_completion_killable_timeout()

swait has been upstream since v4.6. Older kernels have had the
above variants in place for a long time.

Cc: stable <sta...@vger.kernel.org> # 4.6
Signed-off-by: Luis R. Rodriguez <mcg...@kernel.org>
---
 include/linux/swait.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/swait.h b/include/linux/swait.h
index c1f9c62a8a50..2c700694d50a 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -169,4 +169,29 @@ do {                                                       
                \
        __ret;                                                          \
 })
 
+#define __swait_event_killable(wq, condition)                          \
+       ___swait_event(wq, condition, TASK_KILLABLE, 0, schedule())
+
+#define swait_event_killable(wq, condition)                            \
+({                                                                     \
+       int __ret = 0;                                                  \
+       if (!(condition))                                               \
+               __ret = __swait_event_killable(wq, condition);          \
+       __ret;                                                          \
+})
+
+#define __swait_event_killable_timeout(wq, condition, timeout)         \
+       ___swait_event(wq, ___wait_cond_timeout(condition),             \
+                      TASK_KILLABLE, timeout,                          \
+                      __ret = schedule_timeout(__ret))
+
+#define swait_event_killable_timeout(wq, condition, timeout)           \
+({                                                                     \
+       long __ret = timeout;                                           \
+       if (!___wait_cond_timeout(condition))                           \
+               __ret = __swait_event_killable_timeout(wq,              \
+                                               condition, timeout);    \
+       __ret;                                                          \
+})
+
 #endif /* _LINUX_SWAIT_H */
-- 
2.11.0

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