[PATCH net-next] hv_netvsc: Fix book keeping of skb during batching process
From: Haiyang Zhang <haiyangz@microsoft.com>
Date: 2016-01-25 16:13:40
Since eliminating send_completion_tid from struct hv_netvsc_packet, we haven't add proper book keeping for the skb of the batched packet. This patch fixes this issue and allows the previous skb is properly freed. Otherwise, a panic may happen. Thanks to Simon Xiao [off-list ref] for bisecting and analysis. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> --- drivers/net/hyperv/hyperv_net.h | 1 + drivers/net/hyperv/netvsc.c | 33 ++++++++++++++++++++++----------- 2 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index f4130af..fcb92c0 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h@@ -624,6 +624,7 @@ struct nvsp_message { #define RNDIS_PKT_ALIGN_DEFAULT 8 struct multi_send_data { + struct sk_buff *skb; /* skb containing the pkt */ struct hv_netvsc_packet *pkt; /* netvsc pkt pending */ u32 count; /* counter of batched packets */ };
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 059fc52..ec313fc 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c@@ -841,6 +841,18 @@ static inline int netvsc_send_pkt( return ret; } +/* Move packet out of multi send data (msd), and clear msd */ +static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send, + struct sk_buff **msd_skb, + struct multi_send_data *msdp) +{ + *msd_skb = msdp->skb; + *msd_send = msdp->pkt; + msdp->skb = NULL; + msdp->pkt = NULL; + msdp->count = 0; +} + int netvsc_send(struct hv_device *device, struct hv_netvsc_packet *packet, struct rndis_message *rndis_msg,
@@ -855,6 +867,7 @@ int netvsc_send(struct hv_device *device, unsigned int section_index = NETVSC_INVALID_INDEX; struct multi_send_data *msdp; struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL; + struct sk_buff *msd_skb = NULL; bool try_batch; bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
@@ -897,10 +910,8 @@ int netvsc_send(struct hv_device *device, net_device->send_section_size) { section_index = netvsc_get_next_send_section(net_device); if (section_index != NETVSC_INVALID_INDEX) { - msd_send = msdp->pkt; - msdp->pkt = NULL; - msdp->count = 0; - msd_len = 0; + move_pkt_msd(&msd_send, &msd_skb, msdp); + msd_len = 0; } }
@@ -919,31 +930,31 @@ int netvsc_send(struct hv_device *device, packet->total_data_buflen += msd_len; } - if (msdp->pkt) - dev_kfree_skb_any(skb); + if (msdp->skb) + dev_kfree_skb_any(msdp->skb); if (xmit_more && !packet->cp_partial) { + msdp->skb = skb; msdp->pkt = packet; msdp->count++; } else { cur_send = packet; + msdp->skb = NULL; msdp->pkt = NULL; msdp->count = 0; } } else { - msd_send = msdp->pkt; - msdp->pkt = NULL; - msdp->count = 0; + move_pkt_msd(&msd_send, &msd_skb, msdp); cur_send = packet; } if (msd_send) { - m_ret = netvsc_send_pkt(msd_send, net_device, pb, skb); + m_ret = netvsc_send_pkt(msd_send, net_device, NULL, msd_skb); if (m_ret != 0) { netvsc_free_send_slot(net_device, msd_send->send_buf_index); - dev_kfree_skb_any(skb); + dev_kfree_skb_any(msd_skb); } }
--
1.7.4.1