Commit 8fb37be1 authored Jul 15, 2019 by Brian King Committed by Greg Kroah-Hartman Jul 28, 2019

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 <brking@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 7250956f

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;