5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason Xing kerneljasonxing@gmail.com
[ Upstream commit 3c9231ea6497dfc50ac0ef69fff484da27d0df66 ]
When I read through the TSO codes, I found out that we probably miss initializing the tx_flags of last seg when TSO is turned off, which means at the following points no more timestamp (for this last one) will be generated. There are three flags to be handled in this patch: 1. SKBTX_HW_TSTAMP 2. SKBTX_BPF 3. SKBTX_SCHED_TSTAMP Note that SKBTX_BPF[1] was added in 6.14.0-rc2 by commit 6b98ec7e882af ("bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback") and only belongs to net-next branch material for now. The common issue of the above three flags can be fixed by this single patch.
This patch initializes the tx_flags to SKBTX_ANY_TSTAMP like what the UDP GSO does to make the newly segmented last skb inherit the tx_flags so that requested timestamp will be generated in each certain layer, or else that last one has zero value of tx_flags which leads to no timestamp at all.
Fixes: 4ed2d765dfacc ("net-timestamp: TCP timestamping") Signed-off-by: Jason Xing kerneljasonxing@gmail.com Reviewed-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/tcp_offload.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index fc61cd3fea652..27b7887f4f4eb 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -11,12 +11,15 @@ #include <net/tcp.h> #include <net/protocol.h>
-static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq, +static void tcp_gso_tstamp(struct sk_buff *skb, struct sk_buff *gso_skb, unsigned int seq, unsigned int mss) { + u32 flags = skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP; + u32 ts_seq = skb_shinfo(gso_skb)->tskey; + while (skb) { if (before(ts_seq, seq + mss)) { - skb_shinfo(skb)->tx_flags |= SKBTX_SW_TSTAMP; + skb_shinfo(skb)->tx_flags |= flags; skb_shinfo(skb)->tskey = ts_seq; return; } @@ -115,8 +118,8 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, th = tcp_hdr(skb); seq = ntohl(th->seq);
- if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_SW_TSTAMP)) - tcp_gso_tstamp(segs, skb_shinfo(gso_skb)->tskey, seq, mss); + if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP)) + tcp_gso_tstamp(segs, gso_skb, seq, mss);
newcheck = ~csum_fold((__force __wsum)((__force u32)th->check + (__force u32)delta));