[PATCH 2/4] swait: add the missing killable swaits

Luis R. Rodriguez
2017-06-14T22:20:52Z

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 <stable@vger.kernel.org> # 4.6
Signed-off-by: Luis R. Rodriguez <mcgrof@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