[Qemu-devel] [PATCH v2] hw/net/opencores_eth: Allocating Large sized arrays to heap

[Zhou Jie]

open_eth_start_xmit has a huge stack usage of 65536 bytes approx.
Moving large arrays to heap to reduce stack usage.

Signed-off-by: Zhou Jie <address@hidden>
---
 hw/net/opencores_eth.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/hw/net/opencores_eth.c b/hw/net/opencores_eth.c
index c6094fb..fa0a4e7 100644
--- a/hw/net/opencores_eth.c
+++ b/hw/net/opencores_eth.c
@@ -483,7 +483,8 @@ static NetClientInfo net_open_eth_info = {
 
 static void open_eth_start_xmit(OpenEthState *s, desc *tx)
 {
-    uint8_t buf[65536];
+    uint8_t *buf = NULL;
+    uint8_t buffer[0x600];
     unsigned len = GET_FIELD(tx->len_flags, TXD_LEN);
     unsigned tx_len = len;
 
@@ -498,6 +499,11 @@ static void open_eth_start_xmit(OpenEthState *s, desc *tx)
 
     trace_open_eth_start_xmit(tx->buf_ptr, len, tx_len);
 
+    if (tx_len > 0x600) {
+        buf = g_new(uint8_t, tx_len);
+    } else {
+        buf = buffer;
+    }
     if (len > tx_len) {
         len = tx_len;
     }
@@ -506,6 +512,9 @@ static void open_eth_start_xmit(OpenEthState *s, desc *tx)
         memset(buf + len, 0, tx_len - len);
     }
     qemu_send_packet(qemu_get_queue(s->nic), buf, tx_len);
+    if (tx_len > 0x600) {
+        g_free(buf);
+    }
 
     if (tx->len_flags & TXD_WR) {
         s->tx_desc = 0;
-- 
2.5.5