From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 5dcd08cd19912892586c6082d56718333e2d19db ]
While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
While at it, we remove the unnecessary spaces in the doc.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- Documentation/admin-guide/sysctl/net.rst | 2 +- net/core/dev.c | 4 ++-- net/core/gro_cells.c | 2 +- net/xfrm/espintcp.c | 2 +- net/xfrm/xfrm_input.c | 2 +- 5 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 4150f74c521a8..5310f398794c1 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -271,7 +271,7 @@ poll cycle or the number of packets processed reaches netdev_budget. netdev_max_backlog ------------------
-Maximum number of packets, queued on the INPUT side, when the interface +Maximum number of packets, queued on the INPUT side, when the interface receives packets faster than kernel can process them.
netdev_rss_key diff --git a/net/core/dev.c b/net/core/dev.c index 1a0de071fcf45..87cf2e0d8f6f1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4589,7 +4589,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) struct softnet_data *sd; unsigned int old_flow, new_flow;
- if (qlen < (netdev_max_backlog >> 1)) + if (qlen < (READ_ONCE(netdev_max_backlog) >> 1)) return false;
sd = this_cpu_ptr(&softnet_data); @@ -4637,7 +4637,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, if (!netif_running(skb->dev)) goto drop; qlen = skb_queue_len(&sd->input_pkt_queue); - if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { + if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) { if (qlen) { enqueue: __skb_queue_tail(&sd->input_pkt_queue, skb); diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c index 6eb2e5ec2c506..2f66f3f295630 100644 --- a/net/core/gro_cells.c +++ b/net/core/gro_cells.c @@ -26,7 +26,7 @@ int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
cell = this_cpu_ptr(gcells->cells);
- if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) { + if (skb_queue_len(&cell->napi_skbs) > READ_ONCE(netdev_max_backlog)) { drop: atomic_long_inc(&dev->rx_dropped); kfree_skb(skb); diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c index 1f08ebf7d80c5..24ca49ecebea3 100644 --- a/net/xfrm/espintcp.c +++ b/net/xfrm/espintcp.c @@ -170,7 +170,7 @@ int espintcp_queue_out(struct sock *sk, struct sk_buff *skb) { struct espintcp_ctx *ctx = espintcp_getctx(sk);
- if (skb_queue_len(&ctx->out_queue) >= netdev_max_backlog) + if (skb_queue_len(&ctx->out_queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS;
__skb_queue_tail(&ctx->out_queue, skb); diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 3df0861d4390f..5f34bc378fdcf 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -782,7 +782,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
trans = this_cpu_ptr(&xfrm_trans_tasklet);
- if (skb_queue_len(&trans->queue) >= netdev_max_backlog) + if (skb_queue_len(&trans->queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS;
BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb));