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, 98 insertions, 0 deletions

diff --git a/sound/pci/echoaudio/indigoiox.c b/sound/pci/echoaudio/indigoiox.c
new file mode 100644
index 000000000..dfaa56331
--- /dev/null
+++ b/sound/pci/echoaudio/indigoiox.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  ALSA driver for Echoaudio soundcards.
+ *  Copyright (C) 2009 Giuliano Pochini <pochini@shiny.it>
+ */
+
+#define INDIGO_FAMILY
+#define ECHOCARD_INDIGO_IOX
+#define ECHOCARD_NAME "Indigo IOx"
+#define ECHOCARD_HAS_MONITOR
+#define ECHOCARD_HAS_SUPER_INTERLEAVE
+#define ECHOCARD_HAS_VMIXER
+#define ECHOCARD_HAS_STEREO_BIG_ENDIAN32
+
+/* Pipe indexes */
+#define PX_ANALOG_OUT	0	/* 8 */
+#define PX_DIGITAL_OUT	8	/* 0 */
+#define PX_ANALOG_IN	8	/* 2 */
+#define PX_DIGITAL_IN	10	/* 0 */
+#define PX_NUM		10
+
+/* Bus indexes */
+#define BX_ANALOG_OUT	0	/* 2 */
+#define BX_DIGITAL_OUT	2	/* 0 */
+#define BX_ANALOG_IN	2	/* 2 */
+#define BX_DIGITAL_IN	4	/* 0 */
+#define BX_NUM		4
+
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/firmware.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/asoundef.h>
+#include <sound/initval.h>
+#include <linux/atomic.h>
+#include "echoaudio.h"
+
+MODULE_FIRMWARE("ea/loader_dsp.fw");
+MODULE_FIRMWARE("ea/indigo_iox_dsp.fw");
+
+#define FW_361_LOADER		0
+#define FW_INDIGO_IOX_DSP	1
+
+static const struct firmware card_fw[] = {
+	{0, "loader_dsp.fw"},
+	{0, "indigo_iox_dsp.fw"}
+};
+
+static const struct pci_device_id snd_echo_ids[] = {
+	{ PCI_DEVICE_SUB(0x1057, 0x3410, 0xECC0, 0x00D0) },	/* Indigo IOx */
+	{ }
+};
+
+static const struct snd_pcm_hardware pcm_hardware_skel = {
+	.info = SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_SYNC_START,
+	.formats =	SNDRV_PCM_FMTBIT_U8 |
+			SNDRV_PCM_FMTBIT_S16_LE |
+			SNDRV_PCM_FMTBIT_S24_3LE |
+			SNDRV_PCM_FMTBIT_S32_LE |
+			SNDRV_PCM_FMTBIT_S32_BE,
+	.rates = 	SNDRV_PCM_RATE_32000 |
+			SNDRV_PCM_RATE_44100 |
+			SNDRV_PCM_RATE_48000 |
+			SNDRV_PCM_RATE_64000 |
+			SNDRV_PCM_RATE_88200 |
+			SNDRV_PCM_RATE_96000,
+	.rate_min = 32000,
+	.rate_max = 96000,
+	.channels_min = 1,
+	.channels_max = 8,
+	.buffer_bytes_max = 262144,
+	.period_bytes_min = 32,
+	.period_bytes_max = 131072,
+	.periods_min = 2,
+	.periods_max = 220,
+};
+
+#include "indigoiox_dsp.c"
+#include "indigo_express_dsp.c"
+#include "echoaudio_dsp.c"
+#include "echoaudio.c"
+