6.17-stable review patch. If anyone has any objections, please let me know.

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From: Maciej Fijalkowski maciej.fijalkowski@intel.com

[ Upstream commit c30d084960cf316c95fbf145d39974ce1ff7889c ]

We are unnecessarily setting a bunch of skb fields per each processed descriptor, which is redundant for fragmented frames.

Let us set these respective members for first fragment only. To address both paths that we have within xsk_build_skb(), move assignments onto xsk_set_destructor_arg() and rename it to xsk_skb_init_misc().

Signed-off-by: Maciej Fijalkowski maciej.fijalkowski@intel.com Acked-by: Stanislav Fomichev sdf@fomichev.me Reviewed-by: Jason Xing kerneljasonxing@gmail.com Acked-by: Martin KaFai Lau martin.lau@kernel.org Link: https://patch.msgid.link/20250925160009.2474816-2-maciej.fijalkowski@intel.c... Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 0ebc27a4c67d ("xsk: avoid data corruption on cq descriptor number") Signed-off-by: Sasha Levin sashal@kernel.org --- net/xdp/xsk.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 72e34bd2d925c..01f258894faeb 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -618,11 +618,16 @@ static void xsk_destruct_skb(struct sk_buff *skb) sock_wfree(skb); }

-static void xsk_set_destructor_arg(struct sk_buff *skb, u64 addr) +static void xsk_skb_init_misc(struct sk_buff *skb, struct xdp_sock *xs, + u64 addr) { BUILD_BUG_ON(sizeof(struct xsk_addr_head) > sizeof(skb->cb)); INIT_LIST_HEAD(&XSKCB(skb)->addrs_list); + skb->dev = xs->dev; + skb->priority = READ_ONCE(xs->sk.sk_priority); + skb->mark = READ_ONCE(xs->sk.sk_mark); XSKCB(skb)->num_descs = 0; + skb->destructor = xsk_destruct_skb; skb_shinfo(skb)->destructor_arg = (void *)(uintptr_t)addr; }

@@ -673,7 +678,7 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,

skb_reserve(skb, hr);

- xsk_set_destructor_arg(skb, desc->addr); + xsk_skb_init_misc(skb, xs, desc->addr); } else { xsk_addr = kmem_cache_zalloc(xsk_tx_generic_cache, GFP_KERNEL); if (!xsk_addr) @@ -757,7 +762,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, if (unlikely(err)) goto free_err;

- xsk_set_destructor_arg(skb, desc->addr); + xsk_skb_init_misc(skb, xs, desc->addr); } else { int nr_frags = skb_shinfo(skb)->nr_frags; struct xsk_addr_node *xsk_addr; @@ -826,14 +831,10 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,

if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME) skb->skb_mstamp_ns = meta->request.launch_time; + xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); } }

- skb->dev = dev; - skb->priority = READ_ONCE(xs->sk.sk_priority); - skb->mark = READ_ONCE(xs->sk.sk_mark); - skb->destructor = xsk_destruct_skb; - xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); xsk_inc_num_desc(skb);

return skb;