From 26c0114d3f69c3accaf83d56ff1d850bd0213b58 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 3 Aug 2015 13:15:57 +0100 Subject: [PATCH] rtl8139: use ldl/stl wrapper for unaligned 32-bit access The tx offload feature accesses a 16-bit aligned TCP header struct. The 32-bit fields must be accessed using ldl/stl wrappers since some host architectures fault on unaligned access. Suggested-by: Peter Maydell Signed-off-by: Stefan Hajnoczi Reviewed-by: Jason Wang Message-id: 1438604157-29664-4-git-send-email-stefanha@redhat.com --- hw/net/rtl8139.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c index 36be22b99c..366d1b59bf 100644 --- a/hw/net/rtl8139.c +++ b/hw/net/rtl8139.c @@ -2118,7 +2118,11 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) DPRINTF("+++ C+ mode has IP packet\n"); - /* not aligned */ + /* Note on memory alignment: eth_payload_data is 16-bit aligned + * since saved_buffer is allocated with g_malloc() and ETH_HLEN is + * even. 32-bit accesses must use ldl/stl wrappers to avoid + * unaligned accesses. + */ eth_payload_data = saved_buffer + ETH_HLEN; eth_payload_len = saved_size - ETH_HLEN; @@ -2215,7 +2219,7 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) } DPRINTF("+++ C+ mode TSO TCP seqno %08x\n", - be32_to_cpu(p_tcp_hdr->th_seq)); + ldl_be_p(&p_tcp_hdr->th_seq)); /* add 4 TCP pseudoheader fields */ /* copy IP source and destination fields */ @@ -2271,7 +2275,8 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) 0, (uint8_t *) dot1q_buffer); /* add transferred count to TCP sequence number */ - p_tcp_hdr->th_seq = cpu_to_be32(chunk_size + be32_to_cpu(p_tcp_hdr->th_seq)); + stl_be_p(&p_tcp_hdr->th_seq, + chunk_size + ldl_be_p(&p_tcp_hdr->th_seq)); ++send_count; }