6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Kicinski [ Upstream commit d333c8bca6dc3c5e978f6698d39dd799f3b0dc8d ] ethtool refuses to enable tcp-data-split on a device running a single-buffer XDP program (which can't deal with the payload landing in a separate buffer). dev_xdp_sb_prog_count() only looks at xdp_state[].prog though, ignoring bpf_link integration. Get the prog pointer from dev_xdp_prog(), which will consult both. bpf_xdp_link_update() needs a bit of a touch-up, too, since ethtool calls dev_xdp_sb_prog_count() with just the instance lock (for ops-locked devices) - we now have to make sure the link updates happen under that lock. Spotted by AI while reviewing the XDP propagation series, verified and tested on netdevsim with a C test along these lines: link = bpf_program__attach_xdp(prog, ifindex); system("ethtool -G eth0 tcp-data-split on") Fixes: 197258f0ef68 ("net: ethtool: add hds_config member in ethtool_netdev_state") Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20261001012559.297751-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/dev.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index b963fe9bd73ec..079352a20cb99 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10206,13 +10206,15 @@ EXPORT_SYMBOL_GPL(dev_xdp_prog_count); u8 dev_xdp_sb_prog_count(struct net_device *dev) { + struct bpf_prog *prog; u8 count = 0; int i; - for (i = 0; i < __MAX_XDP_MODE; i++) - if (dev->xdp_state[i].prog && - !dev->xdp_state[i].prog->aux->xdp_has_frags) + for (i = 0; i < __MAX_XDP_MODE; i++) { + prog = dev_xdp_prog(dev, i); + if (prog && !prog->aux->xdp_has_frags) count++; + } return count; } @@ -10592,11 +10594,12 @@ static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog, bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode); err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL, xdp_link->flags, new_prog); + if (!err) + old_prog = xchg(&link->prog, new_prog); netdev_unlock_ops(xdp_link->dev); if (err) goto out_unlock; - old_prog = xchg(&link->prog, new_prog); bpf_prog_put(old_prog); out_unlock: -- 2.53.0