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, 254 insertions, 0 deletions

diff --git a/net/mac80211/ethtool.c b/net/mac80211/ethtool.c
new file mode 100644
index 000000000..3d365626f
--- /dev/null
+++ b/net/mac80211/ethtool.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * mac80211 ethtool hooks for cfg80211
+ *
+ * Copied from cfg.c - originally
+ * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2014	Intel Corporation (Author: Johannes Berg)
+ * Copyright (C) 2018, 2022-2023 Intel Corporation
+ */
+#include <linux/types.h>
+#include <net/cfg80211.h>
+#include "ieee80211_i.h"
+#include "sta_info.h"
+#include "driver-ops.h"
+
+static int ieee80211_set_ringparam(struct net_device *dev,
+				   struct ethtool_ringparam *rp,
+				   struct kernel_ethtool_ringparam *kernel_rp,
+				   struct netlink_ext_ack *extack)
+{
+	struct ieee80211_local *local = wiphy_priv(dev->ieee80211_ptr->wiphy);
+
+	if (rp->rx_mini_pending != 0 || rp->rx_jumbo_pending != 0)
+		return -EINVAL;
+
+	guard(wiphy)(local->hw.wiphy);
+
+	return drv_set_ringparam(local, rp->tx_pending, rp->rx_pending);
+}
+
+static void ieee80211_get_ringparam(struct net_device *dev,
+				    struct ethtool_ringparam *rp,
+				    struct kernel_ethtool_ringparam *kernel_rp,
+				    struct netlink_ext_ack *extack)
+{
+	struct ieee80211_local *local = wiphy_priv(dev->ieee80211_ptr->wiphy);
+
+	memset(rp, 0, sizeof(*rp));
+
+	guard(wiphy)(local->hw.wiphy);
+
+	drv_get_ringparam(local, &rp->tx_pending, &rp->tx_max_pending,
+			  &rp->rx_pending, &rp->rx_max_pending);
+}
+
+static const char ieee80211_gstrings_sta_stats[][ETH_GSTRING_LEN] = {
+	"rx_packets", "rx_bytes",
+	"rx_duplicates", "rx_fragments", "rx_dropped",
+	"tx_packets", "tx_bytes",
+	"tx_filtered", "tx_retry_failed", "tx_retries",
+	"tx_handlers_drop", "sta_state", "txrate", "rxrate",
+	"signal", "channel", "noise", "ch_time", "ch_time_busy",
+	"ch_time_ext_busy", "ch_time_rx", "ch_time_tx"
+};
+#define STA_STATS_LEN	ARRAY_SIZE(ieee80211_gstrings_sta_stats)
+
+static int ieee80211_get_sset_count(struct net_device *dev, int sset)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	int rv = 0;
+
+	if (sset == ETH_SS_STATS)
+		rv += STA_STATS_LEN;
+
+	rv += drv_get_et_sset_count(sdata, sset);
+
+	if (rv == 0)
+		return -EOPNOTSUPP;
+	return rv;
+}
+
+static void ieee80211_get_stats(struct net_device *dev,
+				struct ethtool_stats *stats,
+				u64 *data)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *channel;
+	struct sta_info *sta;
+	struct ieee80211_local *local = sdata->local;
+	struct station_info sinfo;
+	struct survey_info survey;
+	int i, q;
+#define STA_STATS_SURVEY_LEN 7
+
+	memset(data, 0, sizeof(u64) * STA_STATS_LEN);
+
+#define ADD_STA_STATS(sta)					\
+	do {							\
+		data[i++] += sinfo.rx_packets;			\
+		data[i++] += sinfo.rx_bytes;			\
+		data[i++] += (sta)->rx_stats.num_duplicates;	\
+		data[i++] += (sta)->rx_stats.fragments;		\
+		data[i++] += sinfo.rx_dropped_misc;		\
+								\
+		data[i++] += sinfo.tx_packets;			\
+		data[i++] += sinfo.tx_bytes;			\
+		data[i++] += (sta)->status_stats.filtered;	\
+		data[i++] += sinfo.tx_failed;			\
+		data[i++] += sinfo.tx_retries;			\
+	} while (0)
+
+	/* For Managed stations, find the single station based on BSSID
+	 * and use that.  For interface types, iterate through all available
+	 * stations and add stats for any station that is assigned to this
+	 * network device.
+	 */
+
+	guard(wiphy)(local->hw.wiphy);
+
+	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+		sta = sta_info_get_bss(sdata, sdata->deflink.u.mgd.bssid);
+
+		if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
+			goto do_survey;
+
+		memset(&sinfo, 0, sizeof(sinfo));
+		sta_set_sinfo(sta, &sinfo, false);
+
+		i = 0;
+		ADD_STA_STATS(&sta->deflink);
+
+		data[i++] = sdata->tx_handlers_drop;
+		data[i++] = sta->sta_state;
+
+
+		if (sinfo.filled & BIT_ULL(NL80211_STA_INFO_TX_BITRATE))
+			data[i] = 100000ULL *
+				cfg80211_calculate_bitrate(&sinfo.txrate);
+		i++;
+		if (sinfo.filled & BIT_ULL(NL80211_STA_INFO_RX_BITRATE))
+			data[i] = 100000ULL *
+				cfg80211_calculate_bitrate(&sinfo.rxrate);
+		i++;
+
+		if (sinfo.filled & BIT_ULL(NL80211_STA_INFO_SIGNAL_AVG))
+			data[i] = (u8)sinfo.signal_avg;
+		i++;
+	} else {
+		list_for_each_entry(sta, &local->sta_list, list) {
+			/* Make sure this station belongs to the proper dev */
+			if (sta->sdata->dev != dev)
+				continue;
+
+			memset(&sinfo, 0, sizeof(sinfo));
+			sta_set_sinfo(sta, &sinfo, false);
+			i = 0;
+			ADD_STA_STATS(&sta->deflink);
+			data[i++] = sdata->tx_handlers_drop;
+		}
+	}
+
+do_survey:
+	i = STA_STATS_LEN - STA_STATS_SURVEY_LEN;
+	/* Get survey stats for current channel */
+	survey.filled = 0;
+
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
+	if (chanctx_conf)
+		channel = chanctx_conf->def.chan;
+	else if (local->open_count > 0 &&
+		 local->open_count == local->virt_monitors &&
+		 sdata->vif.type == NL80211_IFTYPE_MONITOR)
+		channel = local->monitor_chanreq.oper.chan;
+	else
+		channel = NULL;
+	rcu_read_unlock();
+
+	if (channel) {
+		q = 0;
+		do {
+			survey.filled = 0;
+			if (drv_get_survey(local, q, &survey) != 0) {
+				survey.filled = 0;
+				break;
+			}
+			q++;
+		} while (channel != survey.channel);
+	}
+
+	if (survey.filled)
+		data[i++] = survey.channel->center_freq;
+	else
+		data[i++] = 0;
+	if (survey.filled & SURVEY_INFO_NOISE_DBM)
+		data[i++] = (u8)survey.noise;
+	else
+		data[i++] = -1LL;
+	if (survey.filled & SURVEY_INFO_TIME)
+		data[i++] = survey.time;
+	else
+		data[i++] = -1LL;
+	if (survey.filled & SURVEY_INFO_TIME_BUSY)
+		data[i++] = survey.time_busy;
+	else
+		data[i++] = -1LL;
+	if (survey.filled & SURVEY_INFO_TIME_EXT_BUSY)
+		data[i++] = survey.time_ext_busy;
+	else
+		data[i++] = -1LL;
+	if (survey.filled & SURVEY_INFO_TIME_RX)
+		data[i++] = survey.time_rx;
+	else
+		data[i++] = -1LL;
+	if (survey.filled & SURVEY_INFO_TIME_TX)
+		data[i++] = survey.time_tx;
+	else
+		data[i++] = -1LL;
+
+	if (WARN_ON(i != STA_STATS_LEN))
+		return;
+
+	drv_get_et_stats(sdata, stats, &(data[STA_STATS_LEN]));
+}
+
+static void ieee80211_get_strings(struct net_device *dev, u32 sset, u8 *data)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	int sz_sta_stats = 0;
+
+	if (sset == ETH_SS_STATS) {
+		sz_sta_stats = sizeof(ieee80211_gstrings_sta_stats);
+		memcpy(data, ieee80211_gstrings_sta_stats, sz_sta_stats);
+	}
+	drv_get_et_strings(sdata, sset, &(data[sz_sta_stats]));
+}
+
+static int ieee80211_get_regs_len(struct net_device *dev)
+{
+	return 0;
+}
+
+static void ieee80211_get_regs(struct net_device *dev,
+			       struct ethtool_regs *regs,
+			       void *data)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+	regs->version = wdev->wiphy->hw_version;
+	regs->len = 0;
+}
+
+const struct ethtool_ops ieee80211_ethtool_ops = {
+	.get_drvinfo = cfg80211_get_drvinfo,
+	.get_regs_len = ieee80211_get_regs_len,
+	.get_regs = ieee80211_get_regs,
+	.get_link = ethtool_op_get_link,
+	.get_ringparam = ieee80211_get_ringparam,
+	.set_ringparam = ieee80211_set_ringparam,
+	.get_strings = ieee80211_get_strings,
+	.get_ethtool_stats = ieee80211_get_stats,
+	.get_sset_count = ieee80211_get_sset_count,
+};