Commit c31ead3c authored Sep 04, 2019 by Björn Töpel Committed by Greg Kroah-Hartman Jan 27, 2020

xsk: avoid store-tearing when assigning queues



[ Upstream commit 94a997637c5b562fa0ca44fca1d2cd02ec08236f ]

Use WRITE_ONCE when doing the store of tx, rx, fq, and cq, to avoid
potential store-tearing. These members are read outside of the control
mutex in the mmap implementation.

Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Fixes: 37b07693 ("xsk: add missing write- and data-dependency barrier")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 07053105

net/xdp/xsk.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -320,7 +320,7 @@ static int xsk_init_queue(u32 entries, struct xsk_queue **queue,

		/* Make sure queue is ready before it can be seen by others */
		smp_wmb();
		*queue = q;
		WRITE_ONCE(*queue, q);
		return 0;
		}