ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 556 insertions, 0 deletions

diff --git a/net/lapb/lapb_in.c b/net/lapb/lapb_in.c
new file mode 100644
index 000000000..38ae23c09
--- /dev/null
+++ b/net/lapb/lapb_in.c
@@ -0,0 +1,556 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	LAPB release 002
+ *
+ *	This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ *	History
+ *	LAPB 001	Jonathan Naulor	Started Coding
+ *	LAPB 002	Jonathan Naylor	New timer architecture.
+ *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/lapb.h>
+
+/*
+ *	State machine for state 0, Disconnected State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+	case LAPB_SABM:
+		lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		} else {
+			lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state     = LAPB_STATE_3;
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_connect_indication(lapb, LAPB_OK);
+		}
+		break;
+
+	case LAPB_SABME:
+		lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state     = LAPB_STATE_3;
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_connect_indication(lapb, LAPB_OK);
+		} else {
+			lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		}
+		break;
+
+	case LAPB_DISC:
+		lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf);
+		lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf);
+		lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
+		break;
+
+	default:
+		break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 1, Awaiting Connection State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+	case LAPB_SABM:
+		lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		} else {
+			lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+		}
+		break;
+
+	case LAPB_SABME:
+		lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+		} else {
+			lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		}
+		break;
+
+	case LAPB_DISC:
+		lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf);
+		lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf);
+		lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
+		break;
+
+	case LAPB_UA:
+		lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf);
+		if (frame->pf) {
+			lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state     = LAPB_STATE_3;
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_connect_confirmation(lapb, LAPB_OK);
+		}
+		break;
+
+	case LAPB_DM:
+		lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf);
+		if (frame->pf) {
+			lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
+			lapb_clear_queues(lapb);
+			lapb->state = LAPB_STATE_0;
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb_disconnect_indication(lapb, LAPB_REFUSED);
+		}
+		break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 2, Awaiting Release State.
+ *	The handling of the timer(s) is in file lapb_timer.c
+ */
+static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+	case LAPB_SABM:
+	case LAPB_SABME:
+		lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n",
+			 lapb->dev, frame->pf);
+		lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf);
+		lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
+		break;
+
+	case LAPB_DISC:
+		lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf);
+		lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf);
+		lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
+		break;
+
+	case LAPB_UA:
+		lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf);
+		if (frame->pf) {
+			lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
+			lapb->state = LAPB_STATE_0;
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb_disconnect_confirmation(lapb, LAPB_OK);
+		}
+		break;
+
+	case LAPB_DM:
+		lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
+		if (frame->pf) {
+			lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
+			lapb->state = LAPB_STATE_0;
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
+		}
+		break;
+
+	case LAPB_I:
+	case LAPB_REJ:
+	case LAPB_RNR:
+	case LAPB_RR:
+		lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
+		       lapb->dev, frame->pf);
+		lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
+		if (frame->pf)
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 3, Connected State.
+ *	The handling of the timer(s) is in file lapb_timer.c
+ */
+static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	int queued = 0;
+	int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
+						     LAPB_SMODULUS;
+
+	switch (frame->type) {
+	case LAPB_SABM:
+		lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		} else {
+			lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_requeue_frames(lapb);
+		}
+		break;
+
+	case LAPB_SABME:
+		lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_requeue_frames(lapb);
+		} else {
+			lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		}
+		break;
+
+	case LAPB_DISC:
+		lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf);
+		lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
+		lapb_clear_queues(lapb);
+		lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
+		lapb_start_t1timer(lapb);
+		lapb_stop_t2timer(lapb);
+		lapb->state = LAPB_STATE_0;
+		lapb_disconnect_indication(lapb, LAPB_OK);
+		break;
+
+	case LAPB_DM:
+		lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf);
+		lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
+		lapb_clear_queues(lapb);
+		lapb->state = LAPB_STATE_0;
+		lapb_start_t1timer(lapb);
+		lapb_stop_t2timer(lapb);
+		lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
+		break;
+
+	case LAPB_RNR:
+		lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n",
+			 lapb->dev, frame->pf, frame->nr);
+		lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
+		lapb_check_need_response(lapb, frame->cr, frame->pf);
+		if (lapb_validate_nr(lapb, frame->nr)) {
+			lapb_check_iframes_acked(lapb, frame->nr);
+		} else {
+			lapb->frmr_data = *frame;
+			lapb->frmr_type = LAPB_FRMR_Z;
+			lapb_transmit_frmr(lapb);
+			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state   = LAPB_STATE_4;
+			lapb->n2count = 0;
+		}
+		break;
+
+	case LAPB_RR:
+		lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n",
+			 lapb->dev, frame->pf, frame->nr);
+		lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
+		lapb_check_need_response(lapb, frame->cr, frame->pf);
+		if (lapb_validate_nr(lapb, frame->nr)) {
+			lapb_check_iframes_acked(lapb, frame->nr);
+		} else {
+			lapb->frmr_data = *frame;
+			lapb->frmr_type = LAPB_FRMR_Z;
+			lapb_transmit_frmr(lapb);
+			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state   = LAPB_STATE_4;
+			lapb->n2count = 0;
+		}
+		break;
+
+	case LAPB_REJ:
+		lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n",
+			 lapb->dev, frame->pf, frame->nr);
+		lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
+		lapb_check_need_response(lapb, frame->cr, frame->pf);
+		if (lapb_validate_nr(lapb, frame->nr)) {
+			lapb_frames_acked(lapb, frame->nr);
+			lapb_stop_t1timer(lapb);
+			lapb->n2count = 0;
+			lapb_requeue_frames(lapb);
+		} else {
+			lapb->frmr_data = *frame;
+			lapb->frmr_type = LAPB_FRMR_Z;
+			lapb_transmit_frmr(lapb);
+			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state   = LAPB_STATE_4;
+			lapb->n2count = 0;
+		}
+		break;
+
+	case LAPB_I:
+		lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n",
+			 lapb->dev, frame->pf, frame->ns, frame->nr);
+		if (!lapb_validate_nr(lapb, frame->nr)) {
+			lapb->frmr_data = *frame;
+			lapb->frmr_type = LAPB_FRMR_Z;
+			lapb_transmit_frmr(lapb);
+			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state   = LAPB_STATE_4;
+			lapb->n2count = 0;
+			break;
+		}
+		if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
+			lapb_frames_acked(lapb, frame->nr);
+		else
+			lapb_check_iframes_acked(lapb, frame->nr);
+
+		if (frame->ns == lapb->vr) {
+			int cn;
+			cn = lapb_data_indication(lapb, skb);
+			queued = 1;
+			/*
+			 * If upper layer has dropped the frame, we
+			 * basically ignore any further protocol
+			 * processing. This will cause the peer
+			 * to re-transmit the frame later like
+			 * a frame lost on the wire.
+			 */
+			if (cn == NET_RX_DROP) {
+				pr_debug("rx congestion\n");
+				break;
+			}
+			lapb->vr = (lapb->vr + 1) % modulus;
+			lapb->condition &= ~LAPB_REJECT_CONDITION;
+			if (frame->pf)
+				lapb_enquiry_response(lapb);
+			else {
+				if (!(lapb->condition &
+				      LAPB_ACK_PENDING_CONDITION)) {
+					lapb->condition |= LAPB_ACK_PENDING_CONDITION;
+					lapb_start_t2timer(lapb);
+				}
+			}
+		} else {
+			if (lapb->condition & LAPB_REJECT_CONDITION) {
+				if (frame->pf)
+					lapb_enquiry_response(lapb);
+			} else {
+				lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n",
+					 lapb->dev, frame->pf, lapb->vr);
+				lapb->condition |= LAPB_REJECT_CONDITION;
+				lapb_send_control(lapb, LAPB_REJ, frame->pf,
+						  LAPB_RESPONSE);
+				lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+			}
+		}
+		break;
+
+	case LAPB_FRMR:
+		lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n",
+			 lapb->dev, frame->pf,
+			 skb->data);
+		lapb_establish_data_link(lapb);
+		lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev);
+		lapb_requeue_frames(lapb);
+		lapb->state = LAPB_STATE_1;
+		break;
+
+	case LAPB_ILLEGAL:
+		lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf);
+		lapb->frmr_data = *frame;
+		lapb->frmr_type = LAPB_FRMR_W;
+		lapb_transmit_frmr(lapb);
+		lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
+		lapb_start_t1timer(lapb);
+		lapb_stop_t2timer(lapb);
+		lapb->state   = LAPB_STATE_4;
+		lapb->n2count = 0;
+		break;
+	}
+
+	if (!queued)
+		kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 4, Frame Reject State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+	case LAPB_SABM:
+		lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		} else {
+			lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state     = LAPB_STATE_3;
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_connect_indication(lapb, LAPB_OK);
+		}
+		break;
+
+	case LAPB_SABME:
+		lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf);
+		if (lapb->mode & LAPB_EXTENDED) {
+			lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_stop_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state     = LAPB_STATE_3;
+			lapb->condition = 0x00;
+			lapb->n2count   = 0;
+			lapb->vs        = 0;
+			lapb->vr        = 0;
+			lapb->va        = 0;
+			lapb_connect_indication(lapb, LAPB_OK);
+		} else {
+			lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
+				 lapb->dev, frame->pf);
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+		}
+		break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	Process an incoming LAPB frame
+ */
+void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
+{
+	struct lapb_frame frame;
+
+	if (lapb_decode(lapb, skb, &frame) < 0) {
+		kfree_skb(skb);
+		return;
+	}
+
+	switch (lapb->state) {
+	case LAPB_STATE_0:
+		lapb_state0_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_1:
+		lapb_state1_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_2:
+		lapb_state2_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_3:
+		lapb_state3_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_4:
+		lapb_state4_machine(lapb, skb, &frame); break;
+	}
+
+	lapb_kick(lapb);
+}