From 8fb37be120469a4bd729be833d32010d4bba4e41 Mon Sep 17 00:00:00 2001 From: Brian King Date: Mon, 15 Jul 2019 16:41:50 -0500 Subject: [PATCH] bnx2x: Prevent load reordering in tx completion processing [ Upstream commit ea811b795df24644a8eb760b493c43fba4450677 ] This patch fixes an issue seen on Power systems with bnx2x which results in the skb is NULL WARN_ON in bnx2x_free_tx_pkt firing due to the skb pointer getting loaded in bnx2x_free_tx_pkt prior to the hw_cons load in bnx2x_tx_int. Adding a read memory barrier resolves the issue. Signed-off-by: Brian King Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index e3ce29951c5e..3edb81a4f075 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -286,6 +286,9 @@ int bnx2x_tx_int(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata) hw_cons = le16_to_cpu(*txdata->tx_cons_sb); sw_cons = txdata->tx_pkt_cons; + /* Ensure subsequent loads occur after hw_cons */ + smp_rmb(); + while (sw_cons != hw_cons) { u16 pkt_cons; -- GitLab