From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- net/lapb/lapb_in.c | 556 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 556 insertions(+) create mode 100644 net/lapb/lapb_in.c (limited to 'net/lapb/lapb_in.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * 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); +} -- cgit v1.3.1