On Sun, Mar 9, 2025 at 7:13 PM Taehee Yoo <ap420073@xxxxxxxxx> wrote:
>
> The bnxt_rx_pkt() updates ip_summed value at the end if checksum offload
> is enabled.
> When the XDP-MB program is attached and it returns XDP_PASS, the
> bnxt_xdp_build_skb() is called to update skb_shared_info.
> The main purpose of bnxt_xdp_build_skb() is to update skb_shared_info,
> but it updates ip_summed value too if checksum offload is enabled.
> This is actually duplicate work.
>
> When the bnxt_rx_pkt() updates ip_summed value, it checks if ip_summed
> is CHECKSUM_NONE or not.
> It means that ip_summed should be CHECKSUM_NONE at this moment.
> But ip_summed may already be updated to CHECKSUM_UNNECESSARY in the
> XDP-MB-PASS path.
> So the by skb_checksum_none_assert() WARNS about it.
>
> This is duplicate work and updating ip_summed in the
> bnxt_xdp_build_skb() is not needed.
>
> Splat looks like:
> WARNING: CPU: 3 PID: 5782 at ./include/linux/skbuff.h:5155 bnxt_rx_pkt+0x479b/0x7610 [bnxt_en]
> Modules linked in: bnxt_re bnxt_en rdma_ucm rdma_cm iw_cm ib_cm ib_uverbs veth xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_]
> CPU: 3 UID: 0 PID: 5782 Comm: socat Tainted: G W 6.14.0-rc4+ #27
> Tainted: [W]=WARN
> Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021
> RIP: 0010:bnxt_rx_pkt+0x479b/0x7610 [bnxt_en]
> Code: 54 24 0c 4c 89 f1 4c 89 ff c1 ea 1f ff d3 0f 1f 00 49 89 c6 48 85 c0 0f 84 4c e5 ff ff 48 89 c7 e8 ca 3d a0 c8 e9 8f f4 ff ff <0f> 0b f
> RSP: 0018:ffff88881ba09928 EFLAGS: 00010202
> RAX: 0000000000000000 RBX: 00000000c7590303 RCX: 0000000000000000
> RDX: 1ffff1104e7d1610 RSI: 0000000000000001 RDI: ffff8881c91300b8
> RBP: ffff88881ba09b28 R08: ffff888273e8b0d0 R09: ffff888273e8b070
> R10: ffff888273e8b010 R11: ffff888278b0f000 R12: ffff888273e8b080
> R13: ffff8881c9130e00 R14: ffff8881505d3800 R15: ffff888273e8b000
> FS: 00007f5a2e7be080(0000) GS:ffff88881ba00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fff2e708ff8 CR3: 000000013e3b0000 CR4: 00000000007506f0
> PKRU: 55555554
> Call Trace:
> <IRQ>
> ? __warn+0xcd/0x2f0
> ? bnxt_rx_pkt+0x479b/0x7610
> ? report_bug+0x326/0x3c0
> ? handle_bug+0x53/0xa0
> ? exc_invalid_op+0x14/0x50
> ? asm_exc_invalid_op+0x16/0x20
> ? bnxt_rx_pkt+0x479b/0x7610
> ? bnxt_rx_pkt+0x3e41/0x7610
> ? __pfx_bnxt_rx_pkt+0x10/0x10
> ? napi_complete_done+0x2cf/0x7d0
> __bnxt_poll_work+0x4e8/0x1220
> ? __pfx___bnxt_poll_work+0x10/0x10
> ? __pfx_mark_lock.part.0+0x10/0x10
> bnxt_poll_p5+0x36a/0xfa0
> ? __pfx_bnxt_poll_p5+0x10/0x10
> __napi_poll.constprop.0+0xa0/0x440
> net_rx_action+0x899/0xd00
> ...
>
> Following ping.py patch adds xdp-mb-pass case. so ping.py is going
> to be able to reproduce this issue.
>
> Fixes: 1dc4c557bfed ("bnxt: adding bnxt_xdp_build_skb to build skb from multibuffer xdp_buff")
> Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
> ---
>
> v3:
> - No changes.
>
> v2:
> - Patch added.
>
> drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 ++-
> drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 11 ++---------
> drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h | 3 +--
> 3 files changed, 5 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index 218109ee1c23..9afb2c5072b1 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -2218,7 +2218,8 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
> if (!skb)
> goto oom_next_rx;
> } else {
> - skb = bnxt_xdp_build_skb(bp, skb, agg_bufs, rxr->page_pool, &xdp, rxcmp1);
> + skb = bnxt_xdp_build_skb(bp, skb, agg_bufs,
> + rxr->page_pool, &xdp);
> if (!skb) {
> /* we should be able to free the old skb here */
> bnxt_xdp_buff_frags_free(rxr, &xdp);
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> index e9b49cb5b735..299822cacca4 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> @@ -460,20 +460,13 @@ int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
>
> struct sk_buff *
> bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
> - struct page_pool *pool, struct xdp_buff *xdp,
> - struct rx_cmp_ext *rxcmp1)
> + struct page_pool *pool, struct xdp_buff *xdp)
> {
> struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
>
> if (!skb)
> return NULL;
> - skb_checksum_none_assert(skb);
> - if (RX_CMP_L4_CS_OK(rxcmp1)) {
> - if (bp->dev->features & NETIF_F_RXCSUM) {
> - skb->ip_summed = CHECKSUM_UNNECESSARY;
> - skb->csum_level = RX_CMP_ENCAP(rxcmp1);
> - }
> - }
> +
> xdp_update_skb_shared_info(skb, num_frags,
> sinfo->xdp_frags_size,
> BNXT_RX_PAGE_SIZE * num_frags,
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> index 0122782400b8..220285e190fc 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> @@ -33,6 +33,5 @@ void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
> struct xdp_buff *xdp);
> struct sk_buff *bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
> u8 num_frags, struct page_pool *pool,
> - struct xdp_buff *xdp,
> - struct rx_cmp_ext *rxcmp1);
> + struct xdp_buff *xdp);
> #endif
> --
> 2.34.1
>
Reviewed-by: Somnath Kotur <somnath.kotur@xxxxxxxxxxxx>
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