4.14.63-rt41-rc2 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Julia Cartwright <julia@xxxxxx>
[ Upstream commit afa4c06b89a3c0fb7784ff900ccd707bef519cb7 ]
The mainline implementation of read_seqbegin() orders prior loads w.r.t.
the read-side critical section. Fixup the RT writer-boosting
implementation to provide the same guarantee.
Also, while we're here, update the usage of ACCESS_ONCE() to use
READ_ONCE().
Fixes: e69f15cf77c23 ("seqlock: Prevent rt starvation")
Cc: stable-rt@xxxxxxxxxxxxxxx
Signed-off-by: Julia Cartwright <julia@xxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/linux/seqlock.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index a59751276b94..107079a2d7ed 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -462,6 +462,7 @@ static inline unsigned read_seqbegin(seqlock_t *sl)
spin_unlock_wait(&sl->lock);
goto repeat;
}
+ smp_rmb();
return ret;
}
#endif
--
2.18.0
