From e261199872a232beb6541c7dc6af2af0de840a27 Mon Sep 17 00:00:00 2001
From: Yuval Mintz <Yuval.Mintz@qlogic.com>
Date: Sun, 17 Aug 2014 16:47:47 +0300
Subject: [PATCH] bnx2x: Safe bnx2x_panic_dump()

The bnx2x panic dump spills a lot of information from the driver's
fastpath, but may be called while some of the fastpath is uninitialized.

This patch verifies that pointers are already allocated before dereferencing
them to prevent possible kernel panics.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 .../net/ethernet/broadcom/bnx2x/bnx2x_main.c  | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index 0046d1e0ededd..2ea41bd6380f8 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -987,6 +987,12 @@ void bnx2x_panic_dump(struct bnx2x *bp, bool disable_int)
 		u32 *sb_data_p;
 		struct bnx2x_fp_txdata txdata;
 
+		if (!bp->fp)
+			break;
+
+		if (!fp->rx_cons_sb)
+			continue;
+
 		/* Rx */
 		BNX2X_ERR("fp%d: rx_bd_prod(0x%x)  rx_bd_cons(0x%x)  rx_comp_prod(0x%x)  rx_comp_cons(0x%x)  *rx_cons_sb(0x%x)\n",
 			  i, fp->rx_bd_prod, fp->rx_bd_cons,
@@ -999,7 +1005,14 @@ void bnx2x_panic_dump(struct bnx2x *bp, bool disable_int)
 		/* Tx */
 		for_each_cos_in_tx_queue(fp, cos)
 		{
+			if (!fp->txdata_ptr)
+				break;
+
 			txdata = *fp->txdata_ptr[cos];
+
+			if (!txdata.tx_cons_sb)
+				continue;
+
 			BNX2X_ERR("fp%d: tx_pkt_prod(0x%x)  tx_pkt_cons(0x%x)  tx_bd_prod(0x%x)  tx_bd_cons(0x%x)  *tx_cons_sb(0x%x)\n",
 				  i, txdata.tx_pkt_prod,
 				  txdata.tx_pkt_cons, txdata.tx_bd_prod,
@@ -1101,6 +1114,12 @@ void bnx2x_panic_dump(struct bnx2x *bp, bool disable_int)
 	for_each_valid_rx_queue(bp, i) {
 		struct bnx2x_fastpath *fp = &bp->fp[i];
 
+		if (!bp->fp)
+			break;
+
+		if (!fp->rx_cons_sb)
+			continue;
+
 		start = RX_BD(le16_to_cpu(*fp->rx_cons_sb) - 10);
 		end = RX_BD(le16_to_cpu(*fp->rx_cons_sb) + 503);
 		for (j = start; j != end; j = RX_BD(j + 1)) {
@@ -1134,9 +1153,19 @@ void bnx2x_panic_dump(struct bnx2x *bp, bool disable_int)
 	/* Tx */
 	for_each_valid_tx_queue(bp, i) {
 		struct bnx2x_fastpath *fp = &bp->fp[i];
+
+		if (!bp->fp)
+			break;
+
 		for_each_cos_in_tx_queue(fp, cos) {
 			struct bnx2x_fp_txdata *txdata = fp->txdata_ptr[cos];
 
+			if (!fp->txdata_ptr)
+				break;
+
+			if (!txdata.tx_cons_sb)
+				continue;
+
 			start = TX_BD(le16_to_cpu(*txdata->tx_cons_sb) - 10);
 			end = TX_BD(le16_to_cpu(*txdata->tx_cons_sb) + 245);
 			for (j = start; j != end; j = TX_BD(j + 1)) {
-- 
2.30.2