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, 154 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt1015p.c b/sound/soc/codecs/rt1015p.c
new file mode 100644
index 000000000..44e7fe3c3
--- /dev/null
+++ b/sound/soc/codecs/rt1015p.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// rt1015p.c  --  RT1015P ALSA SoC audio amplifier driver
+//
+// Copyright 2020 The Linux Foundation. All rights reserved.
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+#include <sound/soc-dapm.h>
+
+struct rt1015p_priv {
+	struct gpio_desc *sdb;
+	bool calib_done;
+};
+
+static int rt1015p_sdb_event(struct snd_soc_dapm_widget *w,
+		struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_component *component =
+		snd_soc_dapm_to_component(w->dapm);
+	struct rt1015p_priv *rt1015p =
+		snd_soc_component_get_drvdata(component);
+
+	if (!rt1015p->sdb)
+		return 0;
+
+	switch (event) {
+	case SND_SOC_DAPM_PRE_PMU:
+		gpiod_set_value_cansleep(rt1015p->sdb, 1);
+		dev_dbg(component->dev, "set sdb to 1");
+
+		if (!rt1015p->calib_done) {
+			msleep(300);
+			rt1015p->calib_done = true;
+		}
+		break;
+	case SND_SOC_DAPM_POST_PMD:
+		gpiod_set_value_cansleep(rt1015p->sdb, 0);
+		dev_dbg(component->dev, "set sdb to 0");
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget rt1015p_dapm_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("Speaker"),
+	SND_SOC_DAPM_OUT_DRV_E("SDB", SND_SOC_NOPM, 0, 0, NULL, 0,
+			rt1015p_sdb_event,
+			SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD),
+};
+
+static const struct snd_soc_dapm_route rt1015p_dapm_routes[] = {
+	{"SDB", NULL, "HiFi Playback"},
+	{"Speaker", NULL, "SDB"},
+};
+
+#ifdef CONFIG_PM
+static int rt1015p_suspend(struct snd_soc_component *component)
+{
+	struct rt1015p_priv *rt1015p = snd_soc_component_get_drvdata(component);
+
+	rt1015p->calib_done = false;
+	return 0;
+}
+#else
+#define rt1015p_suspend NULL
+#endif
+
+static const struct snd_soc_component_driver rt1015p_component_driver = {
+	.suspend		= rt1015p_suspend,
+	.dapm_widgets		= rt1015p_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(rt1015p_dapm_widgets),
+	.dapm_routes		= rt1015p_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(rt1015p_dapm_routes),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static struct snd_soc_dai_driver rt1015p_dai_driver = {
+	.name = "HiFi",
+	.playback = {
+		.stream_name	= "HiFi Playback",
+		.formats	= SNDRV_PCM_FMTBIT_S24 |
+					SNDRV_PCM_FMTBIT_S32,
+		.rates		= SNDRV_PCM_RATE_48000,
+		.channels_min	= 1,
+		.channels_max	= 2,
+	},
+};
+
+static int rt1015p_platform_probe(struct platform_device *pdev)
+{
+	struct rt1015p_priv *rt1015p;
+
+	rt1015p = devm_kzalloc(&pdev->dev, sizeof(*rt1015p), GFP_KERNEL);
+	if (!rt1015p)
+		return -ENOMEM;
+
+	rt1015p->sdb = devm_gpiod_get_optional(&pdev->dev,
+				"sdb", GPIOD_OUT_LOW);
+	if (IS_ERR(rt1015p->sdb))
+		return PTR_ERR(rt1015p->sdb);
+
+	dev_set_drvdata(&pdev->dev, rt1015p);
+
+	return devm_snd_soc_register_component(&pdev->dev,
+			&rt1015p_component_driver,
+			&rt1015p_dai_driver, 1);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id rt1015p_device_id[] = {
+	{ .compatible = "realtek,rt1015p" },
+	{ .compatible = "realtek,rt1019p" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt1015p_device_id);
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id rt1015p_acpi_match[] = {
+	{ "RTL1015", 0},
+	{ "RTL1019", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, rt1015p_acpi_match);
+#endif
+
+static struct platform_driver rt1015p_platform_driver = {
+	.driver = {
+		.name = "rt1015p",
+		.of_match_table = of_match_ptr(rt1015p_device_id),
+		.acpi_match_table = ACPI_PTR(rt1015p_acpi_match),
+	},
+	.probe = rt1015p_platform_probe,
+};
+module_platform_driver(rt1015p_platform_driver);
+
+MODULE_DESCRIPTION("ASoC RT1015P driver");
+MODULE_LICENSE("GPL v2");