From: Martin Karsten <mkarsten@xxxxxxxxxxxx>
A struct eventpoll's busy_poll_usecs field can be modified via a user
ioctl at any time. All reads of this field should be annotated with
READ_ONCE.
Fixes: 85455c795c07 ("eventpoll: support busy poll per epoll instance")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Martin Karsten <mkarsten@xxxxxxxxxxxx>
Reviewed-by: Joe Damato <jdamato@xxxxxxxxxx>
---
fs/eventpoll.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index f53ca4f7fced..6d0e2f547ae7 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -420,7 +420,7 @@ static bool busy_loop_ep_timeout(unsigned long start_time,
static bool ep_busy_loop_on(struct eventpoll *ep)
{
- return !!ep->busy_poll_usecs || net_busy_loop_on();
+ return !!READ_ONCE(ep->busy_poll_usecs) || net_busy_loop_on();
}
static bool ep_busy_loop_end(void *p, unsigned long start_time)
--
2.25.1
