From 94a997637c5b562fa0ca44fca1d2cd02ec08236f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn.topel@intel.com>
Date: Wed, 4 Sep 2019 13:49:10 +0200
Subject: [PATCH] xsk: avoid store-tearing when assigning queues
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Git-commit: 94a997637c5b562fa0ca44fca1d2cd02ec08236f
Patch-mainline: v5.4-rc1
References: bsc#1111666
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: 37b076933a8e ("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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/xdp/xsk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 187fd157fcff..271d8d3fb11e 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -434,7 +434,7 @@ 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;
}
--
2.16.4