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, 353 insertions, 0 deletions

diff --git a/net/mac80211/ap.c b/net/mac80211/ap.c
new file mode 100644
index 000000000..e7ac99c5a
--- /dev/null
+++ b/net/mac80211/ap.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AP handling
+ *
+ * Partially
+ * Copyright (C) 2026 Intel Corporation
+ */
+
+#include "driver-ops.h"
+#include "ieee80211_i.h"
+#include "rate.h"
+
+static void
+ieee80211_send_eml_op_mode_notif(struct ieee80211_sub_if_data *sdata,
+				 struct ieee80211_mgmt *req, int opt_len)
+{
+	int len = IEEE80211_MIN_ACTION_SIZE(eml_omn);
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_mgmt *mgmt;
+	struct sk_buff *skb;
+
+	len += opt_len; /* optional len */
+	skb = dev_alloc_skb(local->tx_headroom + len);
+	if (!skb)
+		return;
+
+	skb_reserve(skb, local->tx_headroom);
+	mgmt = skb_put_zero(skb, len);
+	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					  IEEE80211_STYPE_ACTION);
+	memcpy(mgmt->da, req->sa, ETH_ALEN);
+	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
+
+	mgmt->u.action.category = WLAN_CATEGORY_PROTECTED_EHT;
+	mgmt->u.action.action_code =
+		WLAN_PROTECTED_EHT_ACTION_EML_OP_MODE_NOTIF;
+	mgmt->u.action.eml_omn.dialog_token =
+		req->u.action.eml_omn.dialog_token;
+	mgmt->u.action.eml_omn.control = req->u.action.eml_omn.control &
+		~(IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE |
+		  IEEE80211_EML_CTRL_INDEV_COEX_ACT);
+	/* Copy optional fields from the received notification frame */
+	memcpy(mgmt->u.action.eml_omn.variable,
+	       req->u.action.eml_omn.variable, opt_len);
+
+	ieee80211_tx_skb(sdata, skb);
+}
+
+static void
+ieee80211_rx_eml_op_mode_notif(struct ieee80211_sub_if_data *sdata,
+			       struct sk_buff *skb)
+{
+	int len = IEEE80211_MIN_ACTION_SIZE(eml_omn);
+	enum nl80211_iftype type = ieee80211_vif_type_p2p(&sdata->vif);
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	const struct wiphy_iftype_ext_capab *ift_ext_capa;
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	struct ieee80211_local *local = sdata->local;
+	u8 control = mgmt->u.action.eml_omn.control;
+	u8 *ptr = mgmt->u.action.eml_omn.variable;
+	struct ieee80211_eml_params eml_params = {
+		.link_id = status->link_id,
+		.control = control,
+	};
+	struct sta_info *sta;
+	int opt_len = 0;
+
+	if (!ieee80211_vif_is_mld(&sdata->vif))
+		return;
+
+	/* eMLSR and eMLMR can't be enabled at the same time */
+	if ((control & IEEE80211_EML_CTRL_EMLSR_MODE) &&
+	    (control & IEEE80211_EML_CTRL_EMLMR_MODE))
+		return;
+
+	if ((control & IEEE80211_EML_CTRL_EMLMR_MODE) &&
+	    (control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE))
+		return;
+
+	ift_ext_capa = cfg80211_get_iftype_ext_capa(local->hw.wiphy, type);
+	if (!ift_ext_capa)
+		return;
+
+	if (!status->link_valid)
+		return;
+
+	sta = sta_info_get_bss(sdata, mgmt->sa);
+	if (!sta)
+		return;
+
+	if (control & IEEE80211_EML_CTRL_EMLSR_MODE) {
+		u8 emlsr_param_update_len;
+
+		if (!(ift_ext_capa->eml_capabilities &
+		      IEEE80211_EML_CAP_EMLSR_SUPP))
+			return;
+
+		opt_len += sizeof(__le16); /* eMLSR link_bitmap */
+		/*
+		 * eMLSR param update field is not part of Notification frame
+		 * sent by the AP to client so account it separately.
+		 */
+		emlsr_param_update_len =
+			!!(control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE);
+
+		if (skb->len < len + opt_len + emlsr_param_update_len)
+			return;
+
+		if (control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE) {
+			u8 pad_delay, trans_delay;
+
+			pad_delay = u8_get_bits(ptr[2],
+						IEEE80211_EML_EMLSR_PAD_DELAY);
+			if (pad_delay >
+			    IEEE80211_EML_CAP_EML_PADDING_DELAY_256US)
+				return;
+
+			trans_delay = u8_get_bits(ptr[2],
+					IEEE80211_EML_EMLSR_TRANS_DELAY);
+			if (trans_delay >
+			    IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_256US)
+				return;
+
+			/* Update sta padding and transition delay */
+			sta->sta.eml_cap =
+				u8_replace_bits(sta->sta.eml_cap,
+						pad_delay,
+						IEEE80211_EML_CAP_EML_PADDING_DELAY);
+			sta->sta.eml_cap =
+				u8_replace_bits(sta->sta.eml_cap,
+						trans_delay,
+						IEEE80211_EML_CAP_EML_TRANSITION_DELAY);
+		}
+	}
+
+	if (control & IEEE80211_EML_CTRL_EMLMR_MODE) {
+		u8 mcs_map_size;
+		int i;
+
+		if (!(ift_ext_capa->eml_capabilities &
+		      IEEE80211_EML_CAP_EMLMR_SUPPORT))
+			return;
+
+		opt_len += sizeof(__le16); /* eMLMR link_bitmap */
+		opt_len++; /* eMLMR mcs_map_count */
+		if (skb->len < len + opt_len)
+			return;
+
+		eml_params.emlmr_mcs_map_count = ptr[2];
+		if (eml_params.emlmr_mcs_map_count > 2)
+			return;
+
+		mcs_map_size = 3 * (1 + eml_params.emlmr_mcs_map_count);
+		opt_len += mcs_map_size;
+		if (skb->len < len + opt_len)
+			return;
+
+		for (i = 0; i < mcs_map_size; i++) {
+			u8 rx_mcs, tx_mcs;
+
+			rx_mcs = u8_get_bits(ptr[3 + i],
+					     IEEE80211_EML_EMLMR_RX_MCS_MAP);
+			if (rx_mcs > 8)
+				return;
+
+			tx_mcs = u8_get_bits(ptr[3 + i],
+					     IEEE80211_EML_EMLMR_TX_MCS_MAP);
+			if (tx_mcs > 8)
+				return;
+		}
+
+		memcpy(eml_params.emlmr_mcs_map_bw, &ptr[3], mcs_map_size);
+	}
+
+	if ((control & IEEE80211_EML_CTRL_EMLSR_MODE) ||
+	    (control & IEEE80211_EML_CTRL_EMLMR_MODE)) {
+		eml_params.link_bitmap = get_unaligned_le16(ptr);
+		if ((eml_params.link_bitmap & sdata->vif.active_links) !=
+		    eml_params.link_bitmap)
+			return;
+	}
+
+	if (drv_set_eml_op_mode(sdata, &sta->sta, &eml_params))
+		return;
+
+	ieee80211_send_eml_op_mode_notif(sdata, mgmt, opt_len);
+}
+
+static void
+ieee80211_rx_uhr_link_reconfig_req(struct ieee80211_sub_if_data *sdata,
+				   struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	const struct element *sub;
+	struct sta_info *sta;
+
+	/*
+	 * rx.c only accepts IEEE80211_UHR_LINK_RECONFIG_REQUEST_OMP_REQUEST
+	 * which is valid, so no need to check the frame type/format/etc.
+	 */
+
+	sta = sta_info_get_bss(sdata, mgmt->sa);
+	if (!sta)
+		return;
+
+	struct ieee802_11_elems *elems __free(kfree) =
+		ieee802_11_parse_elems(mgmt->u.action.uhr_link_reconf_req.variable,
+				       skb->len - IEEE80211_MIN_ACTION_SIZE(uhr_link_reconf_req),
+				       IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ACTION,
+				       NULL);
+	/* STA will assume we processed it, not good */
+	if (!elems)
+		return;
+
+	if (!elems->ml_reconf)
+		return;
+
+	for_each_mle_subelement(sub, (u8 *)elems->ml_reconf,
+				elems->ml_reconf_len) {
+		const struct ieee80211_mle_per_sta_profile *prof =
+			 (const void *)sub->data;
+		struct ieee80211_chanctx_conf *chanctx_conf;
+		struct ieee80211_chanctx *chanctx;
+		struct ieee80211_link_data *link;
+		struct link_sta_info *link_sta;
+		const struct element *chg;
+		u16 control;
+		u8 link_id;
+
+		if (sub->id != IEEE80211_MLE_SUBELEM_PER_STA_PROFILE)
+			continue;
+
+		if (!ieee80211_mle_reconf_sta_prof_size_ok(sub->data,
+							   sub->datalen))
+			return;
+
+		control = le16_to_cpu(prof->control);
+		link_id = control & IEEE80211_MLE_STA_RECONF_CONTROL_LINK_ID;
+
+		if (link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
+			return;
+
+		link = sdata_dereference(sdata->link[link_id], sdata);
+		if (!link)
+			continue;
+
+		chanctx_conf = sdata_dereference(link->conf->chanctx_conf,
+						 sdata);
+		if (!chanctx_conf)
+			continue;
+		chanctx = container_of(chanctx_conf, struct ieee80211_chanctx,
+				       conf);
+
+		link_sta = sdata_dereference(sta->link[link_id], sdata);
+		if (!link_sta)
+			continue;
+
+		/* do we need to handle any other bits? */
+		if (control & ~(IEEE80211_MLE_STA_RECONF_CONTROL_LINK_ID |
+				IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE))
+			continue;
+
+		if (u16_get_bits(control, IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE) !=
+				IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE_UHR_OMP_UPD)
+			continue;
+
+		for_each_element_extid(chg, WLAN_EID_EXT_UHR_MODE_CHG,
+				       prof->variable + prof->sta_info_len - 1,
+				       sub->datalen - sizeof(*prof) -
+				       prof->sta_info_len + 1) {
+			const struct ieee80211_uhr_mode_change_tuple *tuple;
+
+			for_each_uhr_mode_change_tuple(chg->data + 1,
+						       chg->datalen - 1,
+						       tuple) {
+				u8 id = le16_get_bits(tuple->control,
+						      IEEE80211_UHR_MODE_CHANGE_CONTROL_MODE_ID);
+				bool enabled = le16_get_bits(tuple->control,
+							     IEEE80211_UHR_MODE_CHANGE_CONTROL_MODE_ENABLE);
+
+				/* only handle DBE (for now?) */
+				if (id != IEEE80211_UHR_MODE_CHANGE_MODE_ID_DBE)
+					continue;
+
+				link_sta->uhr_dbe_enabled = enabled;
+				/* also recalculates and updates per-STA bw */
+				ieee80211_recalc_chanctx_min_def(sdata->local,
+								 chanctx);
+			}
+		}
+	}
+
+	/* TODO: send a response */
+}
+
+void ieee80211_ap_rx_queued_frame(struct ieee80211_sub_if_data *sdata,
+				  struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+
+	/* rx.c cannot queue any non-action frames to AP interfaces */
+	if (WARN_ON(!ieee80211_is_action(mgmt->frame_control)))
+		return;
+
+	switch (mgmt->u.action.category) {
+	case WLAN_CATEGORY_PROTECTED_EHT:
+		switch (mgmt->u.action.action_code) {
+		case WLAN_PROTECTED_EHT_ACTION_EML_OP_MODE_NOTIF:
+			ieee80211_rx_eml_op_mode_notif(sdata, skb);
+			break;
+		}
+		break;
+	case WLAN_CATEGORY_PROTECTED_UHR:
+		switch (mgmt->u.action.action_code) {
+		case IEEE80211_PROTECTED_UHR_ACTION_LINK_RECONFIG_REQUEST:
+			ieee80211_rx_uhr_link_reconfig_req(sdata, skb);
+			break;
+		}
+		break;
+	}
+}
+
+void ieee80211_uhr_disable_dbe_all_stas(struct ieee80211_link_data *link)
+{
+	struct ieee80211_sub_if_data *sdata = link->sdata;
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_chanctx *chanctx;
+	int link_id = link->link_id;
+	struct sta_info *sta;
+
+	chanctx_conf = sdata_dereference(link->conf->chanctx_conf, sdata);
+	if (!chanctx_conf)
+		return;
+	chanctx = container_of(chanctx_conf, struct ieee80211_chanctx, conf);
+
+	list_for_each_entry(sta, &local->sta_list, list) {
+		struct link_sta_info *link_sta;
+
+		if (sta->sdata->bss != sdata->bss)
+			continue;
+
+		link_sta = sdata_dereference(sta->link[link_id], sdata);
+		if (!link_sta)
+			continue;
+
+		link_sta->uhr_dbe_enabled = false;
+	}
+
+	/* also recalculates and updates per-STA bw */
+	ieee80211_recalc_chanctx_min_def(local, chanctx);
+}