From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B70333DEF7; Fri, 7 Aug 2026 15:16:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115793; cv=none; b=Bc4R1q7p5yYFmPdpArwCWqZFWP0W5hrXhoHAYxhEIkTLhonNTgeX6JxKxDjiCUlewlHAgbHzSH61Qw3+71tMcCLPAHaCUaZrqPMtzv/2p+QD6HqQGzp3gcJKBorgpdsvKhSnfeYOnmZQe0o+R3Iy90cj9AkAZMUH8S0T5sP+ofo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115793; c=relaxed/simple; bh=D3cvk+kjtYbPxdt1e57RyzyNdkyDB5hk485DNjt/pSA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VGrhfiVTGATL1bxcykShQFtiDAcXDs8jeFM8xe6T4XnMETnadM/Z2XhK7QlKbspdb6HKq3IMznGGc3sTpyhzJfliTfPQT3DU1qWmpHm2gfF9TaLFTV1aELjhvPqFaWQDYvl0RBnOdKy4dURnjDVC8LAmNRTy5SRb+tVQlm6DP6E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=h0KsmnOW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="h0KsmnOW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D76761F000E9; Fri, 7 Aug 2026 15:16:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786115792; bh=HhmLpw2q7FG+MX0RpRVbfz+dHVHWpmg6z4Ap3dlco+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=h0KsmnOW2J92V+K+PaZwpT5P2pRIcyNI+TEK2ryZ3zjD6jO4dLF4JfOVDl8iXVTfm /cOvwvFA3AI9+ltqI53Kb5zTUo+tqO6l7inlXuNKjlhHi9d+YXrlGHp4L3g7Ps852y 8/G2oV+DcTDEpZiV/kW9kcNYRRL0+VpRv6MjV9kk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marc Kleine-Budde , Oliver Hartkopp , Paolo Abeni Subject: [PATCH 6.18 392/396] can: use skb hash instead of private variable in headroom Date: Fri, 7 Aug 2026 16:39:12 +0200 Message-ID: <20260807143432.729595415@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143424.272339768@linuxfoundation.org> References: <20260807143424.272339768@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Hartkopp commit d4fb6514ff8ed6912a71294e6b66a5d59ee88007 upstream. The can_skb_priv::skbcnt variable is used to identify CAN skbs in the RX path analogue to the skb->hash. As the skb hash is not filled in CAN skbs move the private skbcnt value to skb->hash and set skb->sw_hash accordingly. The skb->hash is a value used for RPS to identify skbs. Use it as intended. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-1-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni Signed-off-by: Oliver Hartkopp Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/dev/skb.c | 2 -- include/linux/can/core.h | 1 + include/linux/can/skb.h | 2 -- net/can/af_can.c | 14 +++++++++++--- net/can/bcm.c | 2 -- net/can/isotp.c | 3 --- net/can/j1939/socket.c | 1 - net/can/j1939/transport.c | 2 -- net/can/raw.c | 7 +++---- 9 files changed, 15 insertions(+), 19 deletions(-) --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -202,7 +202,6 @@ static void init_can_skb_reserve(struct skb_reset_transport_header(skb); can_skb_reserve(skb); - can_skb_prv(skb)->skbcnt = 0; } struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) @@ -312,7 +311,6 @@ static bool can_skb_headroom_valid(struc if (skb->ip_summed == CHECKSUM_NONE) { /* init headroom */ can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; skb->ip_summed = CHECKSUM_UNNECESSARY; --- a/include/linux/can/core.h +++ b/include/linux/can/core.h @@ -58,6 +58,7 @@ extern void can_rx_unregister(struct net void *data); extern int can_send(struct sk_buff *skb, int loop); +void can_set_skb_uid(struct sk_buff *skb); void can_sock_destruct(struct sock *sk); #endif /* !_CAN_CORE_H */ --- a/include/linux/can/skb.h +++ b/include/linux/can/skb.h @@ -49,13 +49,11 @@ bool can_dropped_invalid_skb(struct net_ /** * struct can_skb_priv - private additional data inside CAN sk_buffs * @ifindex: ifindex of the first interface the CAN frame appeared on - * @skbcnt: atomic counter to have an unique id together with skb pointer * @frame_len: length of CAN frame in data link layer * @cf: align to the following CAN frame at skb->data */ struct can_skb_priv { int ifindex; - int skbcnt; unsigned int frame_len; struct can_frame cf[]; }; --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -641,6 +641,16 @@ static int can_rcv_filter(struct can_dev return matches; } +void can_set_skb_uid(struct sk_buff *skb) +{ + /* create non-zero unique skb identifier together with *skb */ + while (!(skb->hash)) + skb->hash = atomic_inc_return(&skbcounter); + + skb->sw_hash = 1; +} +EXPORT_SYMBOL(can_set_skb_uid); + static void can_receive(struct sk_buff *skb, struct net_device *dev) { struct can_dev_rcv_lists *dev_rcv_lists; @@ -652,9 +662,7 @@ static void can_receive(struct sk_buff * atomic_long_inc(&pkg_stats->rx_frames); atomic_long_inc(&pkg_stats->rx_frames_delta); - /* create non-zero unique skb identifier together with *skb */ - while (!(can_skb_prv(skb)->skbcnt)) - can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); + can_set_skb_uid(skb); rcu_read_lock(); --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -350,7 +350,6 @@ static void bcm_can_tx(struct bcm_op *op can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; skb_put_data(skb, cf, op->cfsiz); @@ -1621,7 +1620,6 @@ static int bcm_tx_send(struct msghdr *ms } can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; skb->dev = dev; can_skb_set_owner(skb, sk); err = can_send(skb, 1); /* send with loopback */ --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -233,7 +233,6 @@ static int isotp_send_fc(struct sock *sk can_skb_reserve(nskb); can_skb_prv(nskb)->ifindex = dev->ifindex; - can_skb_prv(nskb)->skbcnt = 0; nskb->dev = dev; can_skb_set_owner(nskb, sk); @@ -800,7 +799,6 @@ static void isotp_send_cframe(struct iso can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; cf = (struct canfd_frame *)skb->data; skb_put_zero(skb, so->ll.mtu); @@ -1106,7 +1104,6 @@ static int isotp_sendmsg(struct socket * can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; so->tx.len = size; so->tx.idx = 0; --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -897,7 +897,6 @@ static struct sk_buff *j1939_sk_alloc_sk can_skb_reserve(skb); can_skb_prv(skb)->ifindex = ndev->ifindex; - can_skb_prv(skb)->skbcnt = 0; skb_reserve(skb, offsetof(struct can_frame, data)); ret = memcpy_from_msg(skb_put(skb, size), msg, size); --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -613,7 +613,6 @@ sk_buff *j1939_tp_tx_dat_new(struct j193 skb->dev = priv->ndev; can_skb_reserve(skb); can_skb_prv(skb)->ifindex = priv->ndev->ifindex; - can_skb_prv(skb)->skbcnt = 0; /* reserve CAN header */ skb_reserve(skb, offsetof(struct can_frame, data)); @@ -1549,7 +1548,6 @@ j1939_session *j1939_session_fresh_new(s skb->dev = priv->ndev; can_skb_reserve(skb); can_skb_prv(skb)->ifindex = priv->ndev->ifindex; - can_skb_prv(skb)->skbcnt = 0; skcb = j1939_skb_to_cb(skb); memcpy(skcb, rel_skcb, sizeof(*skcb)); --- a/net/can/raw.c +++ b/net/can/raw.c @@ -76,7 +76,7 @@ MODULE_ALIAS("can-proto-1"); struct uniqframe { const struct sk_buff *skb; - int skbcnt; + u32 hash; unsigned int join_rx_count; }; @@ -164,7 +164,7 @@ static void raw_rcv(struct sk_buff *oskb /* eliminate multiple filter matches for the same skb */ if (this_cpu_ptr(ro->uniq)->skb == oskb && - this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { + this_cpu_ptr(ro->uniq)->hash == oskb->hash) { if (!ro->join_filters) return; @@ -174,7 +174,7 @@ static void raw_rcv(struct sk_buff *oskb return; } else { this_cpu_ptr(ro->uniq)->skb = oskb; - this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; + this_cpu_ptr(ro->uniq)->hash = oskb->hash; this_cpu_ptr(ro->uniq)->join_rx_count = 1; /* drop first frame to check all enabled filters? */ if (ro->join_filters && ro->count > 1) @@ -954,7 +954,6 @@ static int raw_sendmsg(struct socket *so can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; /* fill the skb before testing for valid CAN frames */ err = memcpy_from_msg(skb_put(skb, size), msg, size);