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, 215 insertions, 0 deletions

diff --git a/sound/soc/codecs/dmic.c b/sound/soc/codecs/dmic.c
new file mode 100644
index 000000000..cbed11136
--- /dev/null
+++ b/sound/soc/codecs/dmic.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dmic.c  --  SoC audio for Generic Digital MICs
+ *
+ * Author: Liam Girdwood <lrg@slimlogic.co.uk>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/soc-dapm.h>
+
+#define MAX_MODESWITCH_DELAY 70
+static int modeswitch_delay;
+module_param(modeswitch_delay, uint, 0644);
+
+static int wakeup_delay;
+module_param(wakeup_delay, uint, 0644);
+
+struct dmic {
+	struct gpio_desc *gpio_en;
+	struct regulator *vref;
+	int wakeup_delay;
+	/* Delay after DMIC mode switch */
+	int modeswitch_delay;
+};
+
+static int dmic_daiops_trigger(struct snd_pcm_substream *substream,
+			       int cmd, struct snd_soc_dai *dai)
+{
+	struct snd_soc_component *component = dai->component;
+	struct dmic *dmic = snd_soc_component_get_drvdata(component);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_STOP:
+		if (dmic->modeswitch_delay)
+			mdelay(dmic->modeswitch_delay);
+
+		break;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops dmic_dai_ops = {
+	.trigger	= dmic_daiops_trigger,
+};
+
+static int dmic_aif_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 dmic *dmic = snd_soc_component_get_drvdata(component);
+	int ret = 0;
+
+	switch (event) {
+	case SND_SOC_DAPM_POST_PMU:
+		if (dmic->gpio_en)
+			gpiod_set_value_cansleep(dmic->gpio_en, 1);
+
+		if (dmic->vref) {
+			ret = regulator_enable(dmic->vref);
+			if (ret)
+				return ret;
+		}
+
+		if (dmic->wakeup_delay)
+			msleep(dmic->wakeup_delay);
+		break;
+	case SND_SOC_DAPM_POST_PMD:
+		if (dmic->gpio_en)
+			gpiod_set_value_cansleep(dmic->gpio_en, 0);
+
+		if (dmic->vref)
+			ret = regulator_disable(dmic->vref);
+
+		break;
+	}
+
+	return ret;
+}
+
+static struct snd_soc_dai_driver dmic_dai = {
+	.name = "dmic-hifi",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE
+			| SNDRV_PCM_FMTBIT_S24_LE
+			| SNDRV_PCM_FMTBIT_S16_LE
+			| SNDRV_PCM_FMTBIT_DSD_U8
+			| SNDRV_PCM_FMTBIT_DSD_U16_LE
+			| SNDRV_PCM_FMTBIT_DSD_U32_LE
+			| SNDRV_PCM_FMTBIT_DSD_U16_BE
+			| SNDRV_PCM_FMTBIT_DSD_U32_BE,
+	},
+	.ops    = &dmic_dai_ops,
+};
+
+static int dmic_component_probe(struct snd_soc_component *component)
+{
+	struct dmic *dmic;
+
+	dmic = devm_kzalloc(component->dev, sizeof(*dmic), GFP_KERNEL);
+	if (!dmic)
+		return -ENOMEM;
+
+	dmic->vref = devm_regulator_get_optional(component->dev, "vref");
+	if (IS_ERR(dmic->vref)) {
+		if (PTR_ERR(dmic->vref) != -ENODEV)
+			return dev_err_probe(component->dev, PTR_ERR(dmic->vref),
+					     "Failed to get vref\n");
+		dmic->vref = NULL;
+	}
+
+	dmic->gpio_en = devm_gpiod_get_optional(component->dev,
+						"dmicen", GPIOD_OUT_LOW);
+	if (IS_ERR(dmic->gpio_en))
+		return PTR_ERR(dmic->gpio_en);
+
+	device_property_read_u32(component->dev, "wakeup-delay-ms",
+				 &dmic->wakeup_delay);
+	device_property_read_u32(component->dev, "modeswitch-delay-ms",
+				 &dmic->modeswitch_delay);
+	if (wakeup_delay)
+		dmic->wakeup_delay  = wakeup_delay;
+	if (modeswitch_delay)
+		dmic->modeswitch_delay  = modeswitch_delay;
+
+	if (dmic->modeswitch_delay > MAX_MODESWITCH_DELAY)
+		dmic->modeswitch_delay = MAX_MODESWITCH_DELAY;
+
+	snd_soc_component_set_drvdata(component, dmic);
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget dmic_dapm_widgets[] = {
+	SND_SOC_DAPM_AIF_OUT_E("DMIC AIF", "Capture", 0,
+			       SND_SOC_NOPM, 0, 0, dmic_aif_event,
+			       SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
+	SND_SOC_DAPM_INPUT("DMic"),
+};
+
+static const struct snd_soc_dapm_route intercon[] = {
+	{"DMIC AIF", NULL, "DMic"},
+};
+
+static const struct snd_soc_component_driver soc_dmic = {
+	.probe			= dmic_component_probe,
+	.dapm_widgets		= dmic_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(dmic_dapm_widgets),
+	.dapm_routes		= intercon,
+	.num_dapm_routes	= ARRAY_SIZE(intercon),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static int dmic_dev_probe(struct platform_device *pdev)
+{
+	int err;
+	u32 chans;
+	struct snd_soc_dai_driver *dai_drv = &dmic_dai;
+
+	if (pdev->dev.of_node) {
+		err = of_property_read_u32(pdev->dev.of_node, "num-channels", &chans);
+		if (err && (err != -EINVAL))
+			return err;
+
+		if (!err) {
+			if (chans < 1 || chans > 8)
+				return -EINVAL;
+
+			dai_drv = devm_kzalloc(&pdev->dev, sizeof(*dai_drv), GFP_KERNEL);
+			if (!dai_drv)
+				return -ENOMEM;
+
+			memcpy(dai_drv, &dmic_dai, sizeof(*dai_drv));
+			dai_drv->capture.channels_max = chans;
+		}
+	}
+
+	return devm_snd_soc_register_component(&pdev->dev,
+			&soc_dmic, dai_drv, 1);
+}
+
+MODULE_ALIAS("platform:dmic-codec");
+
+static const struct of_device_id dmic_dev_match[] = {
+	{.compatible = "dmic-codec"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, dmic_dev_match);
+
+static struct platform_driver dmic_driver = {
+	.driver = {
+		.name = "dmic-codec",
+		.of_match_table = dmic_dev_match,
+	},
+	.probe = dmic_dev_probe,
+};
+
+module_platform_driver(dmic_driver);
+
+MODULE_DESCRIPTION("Generic DMIC driver");
+MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
+MODULE_LICENSE("GPL");