selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 185 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8782.c b/sound/soc/codecs/wm8782.c
new file mode 100644
index 000000000..3a2acdfa9
--- /dev/null
+++ b/sound/soc/codecs/wm8782.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * sound/soc/codecs/wm8782.c
+ * simple, strap-pin configured 24bit 2ch ADC
+ *
+ * Copyright: 2011 Raumfeld GmbH
+ * Author: Johannes Stezenbach <js@sig21.net>
+ *
+ * based on ad73311.c
+ * Copyright:	Analog Devices Inc.
+ * Author:	Cliff Cai <cliff.cai@analog.com>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/regulator/consumer.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/ac97_codec.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+
+/* regulator power supply names */
+static const char *supply_names[] = {
+	"Vdda", /* analog supply, 2.7V - 3.6V */
+	"Vdd",  /* digital supply, 2.7V - 5.5V */
+};
+
+struct wm8782_priv {
+	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
+	int max_rate;
+};
+
+static int wm8782_dai_startup(struct snd_pcm_substream *sub, struct snd_soc_dai *dai)
+{
+	struct snd_pcm_runtime *runtime = sub->runtime;
+	struct wm8782_priv *priv =
+		snd_soc_component_get_drvdata(dai->component);
+
+	return snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_RATE,
+					   8000, priv->max_rate);
+}
+
+static const struct snd_soc_dapm_widget wm8782_dapm_widgets[] = {
+SND_SOC_DAPM_INPUT("AINL"),
+SND_SOC_DAPM_INPUT("AINR"),
+};
+
+static const struct snd_soc_dapm_route wm8782_dapm_routes[] = {
+	{ "Capture", NULL, "AINL" },
+	{ "Capture", NULL, "AINR" },
+};
+
+static const struct snd_soc_dai_ops wm8782_dai_ops = {
+	.startup = &wm8782_dai_startup,
+};
+
+static struct snd_soc_dai_driver wm8782_dai = {
+	.name = "wm8782",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_192000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			   SNDRV_PCM_FMTBIT_S20_3LE |
+			   SNDRV_PCM_FMTBIT_S24_LE,
+	},
+	.ops = &wm8782_dai_ops,
+};
+
+static int wm8782_soc_probe(struct snd_soc_component *component)
+{
+	struct wm8782_priv *priv = snd_soc_component_get_drvdata(component);
+	return regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
+}
+
+static void wm8782_soc_remove(struct snd_soc_component *component)
+{
+	struct wm8782_priv *priv = snd_soc_component_get_drvdata(component);
+	regulator_bulk_disable(ARRAY_SIZE(priv->supplies), priv->supplies);
+}
+
+#ifdef CONFIG_PM
+static int wm8782_soc_suspend(struct snd_soc_component *component)
+{
+	struct wm8782_priv *priv = snd_soc_component_get_drvdata(component);
+	regulator_bulk_disable(ARRAY_SIZE(priv->supplies), priv->supplies);
+	return 0;
+}
+
+static int wm8782_soc_resume(struct snd_soc_component *component)
+{
+	struct wm8782_priv *priv = snd_soc_component_get_drvdata(component);
+	return regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
+}
+#else
+#define wm8782_soc_suspend      NULL
+#define wm8782_soc_resume       NULL
+#endif /* CONFIG_PM */
+
+static const struct snd_soc_component_driver soc_component_dev_wm8782 = {
+	.probe			= wm8782_soc_probe,
+	.remove			= wm8782_soc_remove,
+	.suspend		= wm8782_soc_suspend,
+	.resume			= wm8782_soc_resume,
+	.dapm_widgets		= wm8782_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(wm8782_dapm_widgets),
+	.dapm_routes		= wm8782_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(wm8782_dapm_routes),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static int wm8782_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct wm8782_priv *priv;
+	int ret, i, fsampen;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+
+	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
+		priv->supplies[i].supply = supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(priv->supplies),
+				      priv->supplies);
+	if (ret < 0)
+		return ret;
+
+	// Assume lowest value by default to avoid inadvertent overclocking
+	fsampen = 0;
+
+	if (np)
+		of_property_read_u32(np, "wlf,fsampen", &fsampen);
+
+	switch (fsampen) {
+	case 0:
+		priv->max_rate = 48000;
+		break;
+	case 1:
+		priv->max_rate = 96000;
+		break;
+	case 2:
+		priv->max_rate = 192000;
+		break;
+	default:
+		dev_err(dev, "Invalid wlf,fsampen value");
+		return -EINVAL;
+	}
+
+	return devm_snd_soc_register_component(&pdev->dev,
+			&soc_component_dev_wm8782, &wm8782_dai, 1);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id wm8782_of_match[] = {
+	{ .compatible = "wlf,wm8782", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, wm8782_of_match);
+#endif
+
+static struct platform_driver wm8782_codec_driver = {
+	.driver = {
+		.name = "wm8782",
+		.of_match_table = of_match_ptr(wm8782_of_match),
+	},
+	.probe = wm8782_probe,
+};
+
+module_platform_driver(wm8782_codec_driver);
+
+MODULE_DESCRIPTION("ASoC WM8782 driver");
+MODULE_AUTHOR("Johannes Stezenbach <js@sig21.net>");
+MODULE_LICENSE("GPL");