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, 81 insertions, 0 deletions

diff --git a/sound/soc/codecs/ad73311.c b/sound/soc/codecs/ad73311.c
new file mode 100644
index 000000000..f6090ac57
--- /dev/null
+++ b/sound/soc/codecs/ad73311.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ad73311.c  --  ALSA Soc AD73311 codec support
+ *
+ * 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 <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/ac97_codec.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+
+#include "ad73311.h"
+
+static const struct snd_soc_dapm_widget ad73311_dapm_widgets[] = {
+SND_SOC_DAPM_INPUT("VINP"),
+SND_SOC_DAPM_INPUT("VINN"),
+SND_SOC_DAPM_OUTPUT("VOUTN"),
+SND_SOC_DAPM_OUTPUT("VOUTP"),
+};
+
+static const struct snd_soc_dapm_route ad73311_dapm_routes[] = {
+	{ "Capture", NULL, "VINP" },
+	{ "Capture", NULL, "VINN" },
+
+	{ "VOUTN", NULL, "Playback" },
+	{ "VOUTP", NULL, "Playback" },
+};
+
+static struct snd_soc_dai_driver ad73311_dai = {
+	.name = "ad73311-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 1,
+		.channels_max = 1,
+		.rates = SNDRV_PCM_RATE_8000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE, },
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 1,
+		.rates = SNDRV_PCM_RATE_8000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE, },
+};
+
+static const struct snd_soc_component_driver soc_component_dev_ad73311 = {
+	.dapm_widgets		= ad73311_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(ad73311_dapm_widgets),
+	.dapm_routes		= ad73311_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(ad73311_dapm_routes),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static int ad73311_probe(struct platform_device *pdev)
+{
+	return devm_snd_soc_register_component(&pdev->dev,
+			&soc_component_dev_ad73311, &ad73311_dai, 1);
+}
+
+static struct platform_driver ad73311_codec_driver = {
+	.driver = {
+			.name = "ad73311",
+	},
+
+	.probe = ad73311_probe,
+};
+
+module_platform_driver(ad73311_codec_driver);
+
+MODULE_DESCRIPTION("ASoC ad73311 driver");
+MODULE_AUTHOR("Cliff Cai ");
+MODULE_LICENSE("GPL");