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, 170 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt9123p.c b/sound/soc/codecs/rt9123p.c
new file mode 100644
index 000000000..584fcb78c
--- /dev/null
+++ b/sound/soc/codecs/rt9123p.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// rt9123p.c -- RT9123 (HW Mode) ALSA SoC Codec driver
+//
+// Author: ChiYuan Huang <cy_huang@richtek.com>
+
+#include <linux/acpi.h>
+#include <linux/delay.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 <linux/property.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+#include <sound/soc-dapm.h>
+
+struct rt9123p_priv {
+	struct gpio_desc *enable;
+	unsigned int enable_delay;
+	int enable_switch;
+};
+
+static int rt9123p_daiops_trigger(struct snd_pcm_substream *substream, int cmd,
+				  struct snd_soc_dai *dai)
+{
+	struct snd_soc_component *comp = dai->component;
+	struct rt9123p_priv *rt9123p = snd_soc_component_get_drvdata(comp);
+
+	if (!rt9123p->enable)
+		return 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		mdelay(rt9123p->enable_delay);
+		if (rt9123p->enable_switch) {
+			gpiod_set_value(rt9123p->enable, 1);
+			dev_dbg(comp->dev, "set enable to 1");
+		}
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		gpiod_set_value(rt9123p->enable, 0);
+		dev_dbg(comp->dev, "set enable to 0");
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int rt9123p_enable_event(struct snd_soc_dapm_widget *w, struct snd_kcontrol *kcontrol,
+				int event)
+{
+	struct snd_soc_component *comp = snd_soc_dapm_to_component(w->dapm);
+	struct rt9123p_priv *rt9123p = snd_soc_component_get_drvdata(comp);
+
+	if (event & SND_SOC_DAPM_POST_PMU)
+		rt9123p->enable_switch = 1;
+	else if (event & SND_SOC_DAPM_POST_PMD)
+		rt9123p->enable_switch = 0;
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget rt9123p_dapm_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("SPK"),
+	SND_SOC_DAPM_OUT_DRV_E("Amp Drv", SND_SOC_NOPM, 0, 0, NULL, 0, rt9123p_enable_event,
+			       SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
+};
+
+static const struct snd_soc_dapm_route rt9123p_dapm_routes[] = {
+	{"Amp Drv", NULL, "HiFi Playback"},
+	{"SPK", NULL, "Amp Drv"},
+};
+
+static const struct snd_soc_component_driver rt9123p_comp_driver = {
+	.dapm_widgets		= rt9123p_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(rt9123p_dapm_widgets),
+	.dapm_routes		= rt9123p_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(rt9123p_dapm_routes),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static const struct snd_soc_dai_ops rt9123p_dai_ops = {
+	.trigger        = rt9123p_daiops_trigger,
+};
+
+static struct snd_soc_dai_driver rt9123p_dai_driver = {
+	.name = "HiFi",
+	.playback = {
+		.stream_name	= "HiFi Playback",
+		.formats	= SNDRV_PCM_FMTBIT_S16 | SNDRV_PCM_FMTBIT_S24 |
+				  SNDRV_PCM_FMTBIT_S32,
+		.rates		= SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
+				  SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_24000 |
+				  SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
+				  SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |
+				  SNDRV_PCM_RATE_96000,
+		.rate_min	= 8000,
+		.rate_max	= 96000,
+		.channels_min	= 1,
+		.channels_max	= 2,
+	},
+	.ops    = &rt9123p_dai_ops,
+};
+
+static int rt9123p_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rt9123p_priv *rt9123p;
+	int ret;
+
+	rt9123p = devm_kzalloc(dev, sizeof(*rt9123p), GFP_KERNEL);
+	if (!rt9123p)
+		return -ENOMEM;
+
+	rt9123p->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(rt9123p->enable))
+		return PTR_ERR(rt9123p->enable);
+
+	ret = device_property_read_u32(dev, "enable-delay-ms", &rt9123p->enable_delay);
+	if (ret) {
+		rt9123p->enable_delay = 0;
+		dev_dbg(dev, "no optional property 'enable-delay-ms' found, default: no delay\n");
+	}
+
+	platform_set_drvdata(pdev, rt9123p);
+
+	return devm_snd_soc_register_component(dev, &rt9123p_comp_driver, &rt9123p_dai_driver, 1);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id rt9123p_device_id[] = {
+	{ .compatible = "richtek,rt9123p" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt9123p_device_id);
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id rt9123p_acpi_match[] = {
+	{ "RT9123P", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, rt9123p_acpi_match);
+#endif
+
+static struct platform_driver rt9123p_platform_driver = {
+	.driver = {
+		.name = "rt9123p",
+		.of_match_table = of_match_ptr(rt9123p_device_id),
+		.acpi_match_table = ACPI_PTR(rt9123p_acpi_match),
+	},
+	.probe	= rt9123p_platform_probe,
+};
+module_platform_driver(rt9123p_platform_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_DESCRIPTION("ASoC rt9123p Driver");
+MODULE_LICENSE("GPL");