i40e: Reduce stack in i40e_dbg_dump_desc

Reduce stack use by using kmemdup and not using a very
large struct on stack.

In function ‘i40e_dbg_dump_desc’:
warning: the frame size of 8192 bytes is larger than 2048 bytes [-Wframe-larger-than=]

Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
index 16ac3f8..433a558 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
@@ -773,7 +773,7 @@ static void i40e_dbg_dump_desc(int cnt, int vsi_seid, int ring_id, int desc_n,
 {
        struct i40e_tx_desc *txd;
        union i40e_rx_desc *rxd;
-       struct i40e_ring ring;
+       struct i40e_ring *ring;
        struct i40e_vsi *vsi;
        int i;
 
@@ -792,29 +792,32 @@ static void i40e_dbg_dump_desc(int cnt, int vsi_seid, int ring_id, int desc_n,
                         vsi_seid);
                return;
        }
-       if (is_rx_ring)
-               ring = *vsi->rx_rings[ring_id];
-       else
-               ring = *vsi->tx_rings[ring_id];
+
+       ring = kmemdup(is_rx_ring
+                      ? vsi->rx_rings[ring_id] : vsi->tx_rings[ring_id],
+                      sizeof(*ring), GFP_KERNEL);
+       if (!ring)
+               return;
+
        if (cnt == 2) {
                dev_info(&pf->pdev->dev, "vsi = %02i %s ring = %02i\n",
                         vsi_seid, is_rx_ring ? "rx" : "tx", ring_id);
-               for (i = 0; i < ring.count; i++) {
+               for (i = 0; i < ring->count; i++) {
                        if (!is_rx_ring) {
-                               txd = I40E_TX_DESC(&ring, i);
+                               txd = I40E_TX_DESC(ring, i);
                                dev_info(&pf->pdev->dev,
                                         "   d[%03i] = 0x%016llx 0x%016llx\n",
                                         i, txd->buffer_addr,
                                         txd->cmd_type_offset_bsz);
                        } else if (sizeof(union i40e_rx_desc) ==
                                   sizeof(union i40e_16byte_rx_desc)) {
-                               rxd = I40E_RX_DESC(&ring, i);
+                               rxd = I40E_RX_DESC(ring, i);
                                dev_info(&pf->pdev->dev,
                                         "   d[%03i] = 0x%016llx 0x%016llx\n",
                                         i, rxd->read.pkt_addr,
                                         rxd->read.hdr_addr);
                        } else {
-                               rxd = I40E_RX_DESC(&ring, i);
+                               rxd = I40E_RX_DESC(ring, i);
                                dev_info(&pf->pdev->dev,
                                         "   d[%03i] = 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
                                         i, rxd->read.pkt_addr,
@@ -823,26 +826,26 @@ static void i40e_dbg_dump_desc(int cnt, int vsi_seid, int ring_id, int desc_n,
                        }
                }
        } else if (cnt == 3) {
-               if (desc_n >= ring.count || desc_n < 0) {
+               if (desc_n >= ring->count || desc_n < 0) {
                        dev_info(&pf->pdev->dev,
                                 "descriptor %d not found\n", desc_n);
                        return;
                }
                if (!is_rx_ring) {
-                       txd = I40E_TX_DESC(&ring, desc_n);
+                       txd = I40E_TX_DESC(ring, desc_n);
                        dev_info(&pf->pdev->dev,
                                 "vsi = %02i tx ring = %02i d[%03i] = 0x%016llx 0x%016llx\n",
                                 vsi_seid, ring_id, desc_n,
                                 txd->buffer_addr, txd->cmd_type_offset_bsz);
                } else if (sizeof(union i40e_rx_desc) ==
                           sizeof(union i40e_16byte_rx_desc)) {
-                       rxd = I40E_RX_DESC(&ring, desc_n);
+                       rxd = I40E_RX_DESC(ring, desc_n);
                        dev_info(&pf->pdev->dev,
                                 "vsi = %02i rx ring = %02i d[%03i] = 0x%016llx 0x%016llx\n",
                                 vsi_seid, ring_id, desc_n,
                                 rxd->read.pkt_addr, rxd->read.hdr_addr);
                } else {
-                       rxd = I40E_RX_DESC(&ring, desc_n);
+                       rxd = I40E_RX_DESC(ring, desc_n);
                        dev_info(&pf->pdev->dev,
                                 "vsi = %02i rx ring = %02i d[%03i] = 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
                                 vsi_seid, ring_id, desc_n,
@@ -852,6 +855,7 @@ static void i40e_dbg_dump_desc(int cnt, int vsi_seid, int ring_id, int desc_n,
        } else {
                dev_info(&pf->pdev->dev, "dump desc rx/tx <vsi_seid> <ring_id> [<desc_n>]\n");
        }
+       kfree(ring);
 }
 
 /**