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, 239 insertions, 0 deletions

diff --git a/sound/soc/codecs/bd28623.c b/sound/soc/codecs/bd28623.c
new file mode 100644
index 000000000..07e7bd79c
--- /dev/null
+++ b/sound/soc/codecs/bd28623.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// ROHM BD28623MUV class D speaker amplifier codec driver.
+//
+// Copyright (c) 2018 Socionext Inc.
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+
+#define BD28623_NUM_SUPPLIES    3
+
+static const char *const bd28623_supply_names[BD28623_NUM_SUPPLIES] = {
+	"VCCA",
+	"VCCP1",
+	"VCCP2",
+};
+
+struct bd28623_priv {
+	struct device *dev;
+	struct regulator_bulk_data supplies[BD28623_NUM_SUPPLIES];
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *mute_gpio;
+
+	int switch_spk;
+};
+
+static const struct snd_soc_dapm_widget bd28623_widgets[] = {
+	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_OUTPUT("OUT1P"),
+	SND_SOC_DAPM_OUTPUT("OUT1N"),
+	SND_SOC_DAPM_OUTPUT("OUT2P"),
+	SND_SOC_DAPM_OUTPUT("OUT2N"),
+};
+
+static const struct snd_soc_dapm_route bd28623_routes[] = {
+	{ "OUT1P", NULL, "DAC" },
+	{ "OUT1N", NULL, "DAC" },
+	{ "OUT2P", NULL, "DAC" },
+	{ "OUT2N", NULL, "DAC" },
+};
+
+static int bd28623_power_on(struct bd28623_priv *bd)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(bd->supplies), bd->supplies);
+	if (ret) {
+		dev_err(bd->dev, "Failed to enable supplies: %d\n", ret);
+		return ret;
+	}
+
+	gpiod_set_value_cansleep(bd->reset_gpio, 0);
+	usleep_range(300000, 400000);
+
+	return 0;
+}
+
+static void bd28623_power_off(struct bd28623_priv *bd)
+{
+	gpiod_set_value_cansleep(bd->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(bd->supplies), bd->supplies);
+}
+
+static int bd28623_get_switch_spk(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	ucontrol->value.integer.value[0] = bd->switch_spk;
+
+	return 0;
+}
+
+static int bd28623_set_switch_spk(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	if (bd->switch_spk == ucontrol->value.integer.value[0])
+		return 0;
+
+	bd->switch_spk = ucontrol->value.integer.value[0];
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new bd28623_controls[] = {
+	SOC_SINGLE_BOOL_EXT("Speaker Switch", 0,
+			    bd28623_get_switch_spk, bd28623_set_switch_spk),
+};
+
+static int bd28623_codec_probe(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	bd->switch_spk = 1;
+
+	ret = bd28623_power_on(bd);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static void bd28623_codec_remove(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	bd28623_power_off(bd);
+}
+
+static int bd28623_codec_suspend(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	bd28623_power_off(bd);
+
+	return 0;
+}
+
+static int bd28623_codec_resume(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	ret = bd28623_power_on(bd);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static const struct snd_soc_component_driver soc_codec_bd = {
+	.probe			= bd28623_codec_probe,
+	.remove			= bd28623_codec_remove,
+	.suspend		= bd28623_codec_suspend,
+	.resume			= bd28623_codec_resume,
+	.dapm_widgets		= bd28623_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(bd28623_widgets),
+	.dapm_routes		= bd28623_routes,
+	.num_dapm_routes	= ARRAY_SIZE(bd28623_routes),
+	.controls		= bd28623_controls,
+	.num_controls		= ARRAY_SIZE(bd28623_controls),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static struct snd_soc_dai_driver soc_dai_bd = {
+	.name     = "bd28623-speaker",
+	.playback = {
+		.stream_name  = "Playback",
+		.formats      = SNDRV_PCM_FMTBIT_S32_LE |
+				SNDRV_PCM_FMTBIT_S24_LE |
+				SNDRV_PCM_FMTBIT_S16_LE,
+		.rates        = SNDRV_PCM_RATE_48000 |
+				SNDRV_PCM_RATE_44100 |
+				SNDRV_PCM_RATE_32000,
+		.channels_min = 2,
+		.channels_max = 2,
+	},
+};
+
+static int bd28623_probe(struct platform_device *pdev)
+{
+	struct bd28623_priv *bd;
+	struct device *dev = &pdev->dev;
+	int i, ret;
+
+	bd = devm_kzalloc(&pdev->dev, sizeof(struct bd28623_priv), GFP_KERNEL);
+	if (!bd)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(bd->supplies); i++)
+		bd->supplies[i].supply = bd28623_supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(bd->supplies),
+				      bd->supplies);
+	if (ret) {
+		dev_err(dev, "Failed to get supplies: %d\n", ret);
+		return ret;
+	}
+
+	bd->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(bd->reset_gpio)) {
+		dev_err(dev, "Failed to request reset_gpio: %ld\n",
+			PTR_ERR(bd->reset_gpio));
+		return PTR_ERR(bd->reset_gpio);
+	}
+
+	bd->mute_gpio = devm_gpiod_get_optional(dev, "mute",
+						GPIOD_OUT_HIGH);
+	if (IS_ERR(bd->mute_gpio)) {
+		dev_err(dev, "Failed to request mute_gpio: %ld\n",
+			PTR_ERR(bd->mute_gpio));
+		return PTR_ERR(bd->mute_gpio);
+	}
+
+	platform_set_drvdata(pdev, bd);
+	bd->dev = dev;
+
+	return devm_snd_soc_register_component(dev, &soc_codec_bd,
+					       &soc_dai_bd, 1);
+}
+
+static const struct of_device_id bd28623_of_match[] __maybe_unused = {
+	{ .compatible = "rohm,bd28623", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, bd28623_of_match);
+
+static struct platform_driver bd28623_codec_driver = {
+	.driver = {
+		.name = "bd28623",
+		.of_match_table = of_match_ptr(bd28623_of_match),
+	},
+	.probe  = bd28623_probe,
+};
+module_platform_driver(bd28623_codec_driver);
+
+MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
+MODULE_DESCRIPTION("ROHM BD28623 speaker amplifier driver");
+MODULE_LICENSE("GPL v2");