From: Brian King Date: Mon, 15 Jul 2019 21:41:50 +0000 (-0500) Subject: bnx2x: Prevent load reordering in tx completion processing X-Git-Tag: v4.4.187~71 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a4af24423e5f75a2bcb1dec95365d89a78cf7c7a;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index ebc4518d598ad..4dc5e12dbfce4 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -288,6 +288,9 @@ 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;