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, 309 insertions, 0 deletions

diff --git a/net/mac80211/tests/util.c b/net/mac80211/tests/util.c
new file mode 100644
index 000000000..0b01264af
--- /dev/null
+++ b/net/mac80211/tests/util.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Utilities for mac80211 unit testing
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+#include <linux/ieee80211.h>
+#include <net/mac80211.h>
+#include <kunit/test.h>
+#include <kunit/test-bug.h>
+#include "util.h"
+
+#define CHAN2G(_freq)  { \
+	.band = NL80211_BAND_2GHZ, \
+	.center_freq = (_freq), \
+	.hw_value = (_freq), \
+}
+
+static const struct ieee80211_channel channels_2ghz[] = {
+	CHAN2G(2412), /* Channel 1 */
+	CHAN2G(2417), /* Channel 2 */
+	CHAN2G(2422), /* Channel 3 */
+	CHAN2G(2427), /* Channel 4 */
+	CHAN2G(2432), /* Channel 5 */
+	CHAN2G(2437), /* Channel 6 */
+	CHAN2G(2442), /* Channel 7 */
+	CHAN2G(2447), /* Channel 8 */
+	CHAN2G(2452), /* Channel 9 */
+	CHAN2G(2457), /* Channel 10 */
+	CHAN2G(2462), /* Channel 11 */
+	CHAN2G(2467), /* Channel 12 */
+	CHAN2G(2472), /* Channel 13 */
+	CHAN2G(2484), /* Channel 14 */
+};
+
+#define CHAN5G(_freq) { \
+	.band = NL80211_BAND_5GHZ, \
+	.center_freq = (_freq), \
+	.hw_value = (_freq), \
+}
+
+static const struct ieee80211_channel channels_5ghz[] = {
+	CHAN5G(5180), /* Channel 36 */
+	CHAN5G(5200), /* Channel 40 */
+	CHAN5G(5220), /* Channel 44 */
+	CHAN5G(5240), /* Channel 48 */
+};
+
+static const struct ieee80211_rate bitrates[] = {
+	{ .bitrate = 10 },
+	{ .bitrate = 20, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
+	{ .bitrate = 55, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
+	{ .bitrate = 110, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
+	{ .bitrate = 60 },
+	{ .bitrate = 90 },
+	{ .bitrate = 120 },
+	{ .bitrate = 180 },
+	{ .bitrate = 240 },
+	{ .bitrate = 360 },
+	{ .bitrate = 480 },
+	{ .bitrate = 540 }
+};
+
+/* Copied from hwsim except that it only supports 4 EHT streams and STA/P2P mode */
+static const struct ieee80211_sband_iftype_data sband_capa_5ghz[] = {
+	{
+		.types_mask = BIT(NL80211_IFTYPE_STATION) |
+			      BIT(NL80211_IFTYPE_P2P_CLIENT),
+		.he_cap = {
+			.has_he = true,
+			.he_cap_elem = {
+				.mac_cap_info[0] =
+					IEEE80211_HE_MAC_CAP0_HTC_HE,
+				.mac_cap_info[1] =
+					IEEE80211_HE_MAC_CAP1_TF_MAC_PAD_DUR_16US |
+					IEEE80211_HE_MAC_CAP1_MULTI_TID_AGG_RX_QOS_8,
+				.mac_cap_info[2] =
+					IEEE80211_HE_MAC_CAP2_BSR |
+					IEEE80211_HE_MAC_CAP2_MU_CASCADING |
+					IEEE80211_HE_MAC_CAP2_ACK_EN,
+				.mac_cap_info[3] =
+					IEEE80211_HE_MAC_CAP3_OMI_CONTROL |
+					IEEE80211_HE_MAC_CAP3_MAX_AMPDU_LEN_EXP_EXT_3,
+				.mac_cap_info[4] = IEEE80211_HE_MAC_CAP4_AMSDU_IN_AMPDU,
+				.phy_cap_info[0] =
+					IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_80MHZ_IN_5G |
+					IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G |
+					IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G,
+				.phy_cap_info[1] =
+					IEEE80211_HE_PHY_CAP1_PREAMBLE_PUNC_RX_MASK |
+					IEEE80211_HE_PHY_CAP1_DEVICE_CLASS_A |
+					IEEE80211_HE_PHY_CAP1_LDPC_CODING_IN_PAYLOAD |
+					IEEE80211_HE_PHY_CAP1_MIDAMBLE_RX_TX_MAX_NSTS,
+				.phy_cap_info[2] =
+					IEEE80211_HE_PHY_CAP2_NDP_4x_LTF_AND_3_2US |
+					IEEE80211_HE_PHY_CAP2_STBC_TX_UNDER_80MHZ |
+					IEEE80211_HE_PHY_CAP2_STBC_RX_UNDER_80MHZ |
+					IEEE80211_HE_PHY_CAP2_UL_MU_FULL_MU_MIMO |
+					IEEE80211_HE_PHY_CAP2_UL_MU_PARTIAL_MU_MIMO,
+
+				/* Leave all the other PHY capability bytes
+				 * unset, as DCM, beam forming, RU and PPE
+				 * threshold information are not supported
+				 */
+			},
+			.he_mcs_nss_supp = {
+				.rx_mcs_80 = cpu_to_le16(0xfffa),
+				.tx_mcs_80 = cpu_to_le16(0xfffa),
+				.rx_mcs_160 = cpu_to_le16(0xfffa),
+				.tx_mcs_160 = cpu_to_le16(0xfffa),
+				.rx_mcs_80p80 = cpu_to_le16(0xfffa),
+				.tx_mcs_80p80 = cpu_to_le16(0xfffa),
+			},
+		},
+		.eht_cap = {
+			.has_eht = true,
+			.eht_cap_elem = {
+				.mac_cap_info[0] =
+					IEEE80211_EHT_MAC_CAP0_EPCS_PRIO_ACCESS |
+					IEEE80211_EHT_MAC_CAP0_OM_CONTROL |
+					IEEE80211_EHT_MAC_CAP0_TRIG_TXOP_SHARING_MODE1,
+				.phy_cap_info[0] =
+					IEEE80211_EHT_PHY_CAP0_242_TONE_RU_GT20MHZ |
+					IEEE80211_EHT_PHY_CAP0_NDP_4_EHT_LFT_32_GI |
+					IEEE80211_EHT_PHY_CAP0_PARTIAL_BW_UL_MU_MIMO |
+					IEEE80211_EHT_PHY_CAP0_SU_BEAMFORMER |
+					IEEE80211_EHT_PHY_CAP0_SU_BEAMFORMEE |
+					IEEE80211_EHT_PHY_CAP0_BEAMFORMEE_SS_80MHZ_MASK,
+				.phy_cap_info[1] =
+					IEEE80211_EHT_PHY_CAP1_BEAMFORMEE_SS_80MHZ_MASK |
+					IEEE80211_EHT_PHY_CAP1_BEAMFORMEE_SS_160MHZ_MASK,
+				.phy_cap_info[2] =
+					IEEE80211_EHT_PHY_CAP2_SOUNDING_DIM_80MHZ_MASK |
+					IEEE80211_EHT_PHY_CAP2_SOUNDING_DIM_160MHZ_MASK,
+				.phy_cap_info[3] =
+					IEEE80211_EHT_PHY_CAP3_NG_16_SU_FEEDBACK |
+					IEEE80211_EHT_PHY_CAP3_NG_16_MU_FEEDBACK |
+					IEEE80211_EHT_PHY_CAP3_CODEBOOK_4_2_SU_FDBK |
+					IEEE80211_EHT_PHY_CAP3_CODEBOOK_7_5_MU_FDBK |
+					IEEE80211_EHT_PHY_CAP3_TRIG_SU_BF_FDBK |
+					IEEE80211_EHT_PHY_CAP3_TRIG_MU_BF_PART_BW_FDBK |
+					IEEE80211_EHT_PHY_CAP3_TRIG_CQI_FDBK,
+				.phy_cap_info[4] =
+					IEEE80211_EHT_PHY_CAP4_PART_BW_DL_MU_MIMO |
+					IEEE80211_EHT_PHY_CAP4_PSR_SR_SUPP |
+					IEEE80211_EHT_PHY_CAP4_POWER_BOOST_FACT_SUPP |
+					IEEE80211_EHT_PHY_CAP4_EHT_MU_PPDU_4_EHT_LTF_08_GI |
+					IEEE80211_EHT_PHY_CAP4_MAX_NC_MASK,
+				.phy_cap_info[5] =
+					IEEE80211_EHT_PHY_CAP5_NON_TRIG_CQI_FEEDBACK |
+					IEEE80211_EHT_PHY_CAP5_TX_LESS_242_TONE_RU_SUPP |
+					IEEE80211_EHT_PHY_CAP5_RX_LESS_242_TONE_RU_SUPP |
+					IEEE80211_EHT_PHY_CAP5_PPE_THRESHOLD_PRESENT |
+					IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_MASK |
+					IEEE80211_EHT_PHY_CAP5_MAX_NUM_SUPP_EHT_LTF_MASK,
+				.phy_cap_info[6] =
+					IEEE80211_EHT_PHY_CAP6_MAX_NUM_SUPP_EHT_LTF_MASK |
+					IEEE80211_EHT_PHY_CAP6_MCS15_SUPP_MASK,
+				.phy_cap_info[7] =
+					IEEE80211_EHT_PHY_CAP7_20MHZ_STA_RX_NDP_WIDER_BW |
+					IEEE80211_EHT_PHY_CAP7_NON_OFDMA_UL_MU_MIMO_80MHZ |
+					IEEE80211_EHT_PHY_CAP7_NON_OFDMA_UL_MU_MIMO_160MHZ |
+					IEEE80211_EHT_PHY_CAP7_MU_BEAMFORMER_80MHZ |
+					IEEE80211_EHT_PHY_CAP7_MU_BEAMFORMER_160MHZ,
+			},
+
+			/* For all MCS and bandwidth, set 4 NSS for both Tx and
+			 * Rx
+			 */
+			.eht_mcs_nss_supp = {
+				/*
+				 * As B1 and B2 are set in the supported
+				 * channel width set field in the HE PHY
+				 * capabilities information field include all
+				 * the following MCS/NSS.
+				 */
+				.bw._80 = {
+					.rx_tx_mcs9_max_nss = 0x44,
+					.rx_tx_mcs11_max_nss = 0x44,
+					.rx_tx_mcs13_max_nss = 0x44,
+				},
+				.bw._160 = {
+					.rx_tx_mcs9_max_nss = 0x44,
+					.rx_tx_mcs11_max_nss = 0x44,
+					.rx_tx_mcs13_max_nss = 0x44,
+				},
+			},
+			/* PPE threshold information is not supported */
+		},
+	},
+};
+
+int t_sdata_init(struct kunit_resource *resource, void *ctx)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct t_sdata *t_sdata;
+
+	t_sdata = kzalloc_obj(*t_sdata);
+	KUNIT_ASSERT_NOT_NULL(test, t_sdata);
+
+	resource->data = t_sdata;
+	resource->name = "sdata";
+
+	t_sdata->sdata = kzalloc_obj(*t_sdata->sdata);
+	KUNIT_ASSERT_NOT_NULL(test, t_sdata->sdata);
+
+	t_sdata->wiphy = kzalloc_obj(*t_sdata->wiphy);
+	KUNIT_ASSERT_NOT_NULL(test, t_sdata->wiphy);
+
+	strscpy(t_sdata->sdata->name, "kunit");
+
+	t_sdata->sdata->local = &t_sdata->local;
+	t_sdata->sdata->local->hw.wiphy = t_sdata->wiphy;
+	t_sdata->sdata->wdev.wiphy = t_sdata->wiphy;
+	t_sdata->sdata->vif.type = NL80211_IFTYPE_STATION;
+
+	t_sdata->sdata->deflink.sdata = t_sdata->sdata;
+	t_sdata->sdata->deflink.link_id = 0;
+
+	t_sdata->wiphy->bands[NL80211_BAND_2GHZ] = &t_sdata->band_2ghz;
+	t_sdata->wiphy->bands[NL80211_BAND_5GHZ] = &t_sdata->band_5ghz;
+
+	for (int band = NL80211_BAND_2GHZ; band <= NL80211_BAND_5GHZ; band++) {
+		struct ieee80211_supported_band *sband;
+
+		sband = t_sdata->wiphy->bands[band];
+		sband->band = band;
+
+		sband->bitrates =
+			kmemdup(bitrates, sizeof(bitrates), GFP_KERNEL);
+		sband->n_bitrates = ARRAY_SIZE(bitrates);
+
+		/* Initialize channels, feel free to add more channels/bands */
+		switch (band) {
+		case NL80211_BAND_2GHZ:
+			sband->channels = kmemdup(channels_2ghz,
+						  sizeof(channels_2ghz),
+						  GFP_KERNEL);
+			sband->n_channels = ARRAY_SIZE(channels_2ghz);
+			sband->bitrates = kmemdup(bitrates,
+						  sizeof(bitrates),
+						  GFP_KERNEL);
+			sband->n_bitrates = ARRAY_SIZE(bitrates);
+			break;
+		case NL80211_BAND_5GHZ:
+			sband->channels = kmemdup(channels_5ghz,
+						  sizeof(channels_5ghz),
+						  GFP_KERNEL);
+			sband->n_channels = ARRAY_SIZE(channels_5ghz);
+			sband->bitrates = kmemdup(bitrates,
+						  sizeof(bitrates),
+						  GFP_KERNEL);
+			sband->n_bitrates = ARRAY_SIZE(bitrates);
+
+			sband->vht_cap.vht_supported = true;
+			sband->vht_cap.cap =
+				IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
+				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ |
+				IEEE80211_VHT_CAP_RXLDPC |
+				IEEE80211_VHT_CAP_SHORT_GI_80 |
+				IEEE80211_VHT_CAP_SHORT_GI_160 |
+				IEEE80211_VHT_CAP_TXSTBC |
+				IEEE80211_VHT_CAP_RXSTBC_4 |
+				IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
+			sband->vht_cap.vht_mcs.rx_mcs_map =
+				cpu_to_le16(IEEE80211_VHT_MCS_SUPPORT_0_9 << 0 |
+					    IEEE80211_VHT_MCS_SUPPORT_0_9 << 2 |
+					    IEEE80211_VHT_MCS_SUPPORT_0_9 << 4 |
+					    IEEE80211_VHT_MCS_SUPPORT_0_9 << 6);
+			sband->vht_cap.vht_mcs.tx_mcs_map =
+				sband->vht_cap.vht_mcs.rx_mcs_map;
+			break;
+		default:
+			continue;
+		}
+
+		sband->ht_cap.ht_supported = band != NL80211_BAND_6GHZ;
+		sband->ht_cap.cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
+					IEEE80211_HT_CAP_GRN_FLD |
+					IEEE80211_HT_CAP_SGI_20 |
+					IEEE80211_HT_CAP_SGI_40 |
+					IEEE80211_HT_CAP_DSSSCCK40;
+		sband->ht_cap.ampdu_factor = 0x3;
+		sband->ht_cap.ampdu_density = 0x6;
+		memset(&sband->ht_cap.mcs, 0, sizeof(sband->ht_cap.mcs));
+		sband->ht_cap.mcs.rx_mask[0] = 0xff;
+		sband->ht_cap.mcs.rx_mask[1] = 0xff;
+		sband->ht_cap.mcs.tx_params = IEEE80211_HT_MCS_TX_DEFINED;
+	}
+
+	ieee80211_set_sband_iftype_data(&t_sdata->band_5ghz, sband_capa_5ghz);
+
+	return 0;
+}
+
+void t_sdata_exit(struct kunit_resource *resource)
+{
+	struct t_sdata *t_sdata = resource->data;
+
+	kfree(t_sdata->band_2ghz.channels);
+	kfree(t_sdata->band_2ghz.bitrates);
+	kfree(t_sdata->band_5ghz.channels);
+	kfree(t_sdata->band_5ghz.bitrates);
+
+	kfree(t_sdata->sdata);
+	kfree(t_sdata->wiphy);
+
+	kfree(t_sdata);
+}