We need to issue a full memory barrier prior making a signalling decision. Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/hv/ring_buffer.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 2919395..67dc245 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -104,6 +104,7 @@ static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) u32 cur_write_sz; u32 pending_sz; + mb(); pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); /* If the other end is not blocked on write don't bother. */ if (pending_sz == 0) -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html