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, 90 insertions, 0 deletions

diff --git a/include/uapi/sound/hdsp.h b/include/uapi/sound/hdsp.h
new file mode 100644
index 000000000..096195465
--- /dev/null
+++ b/include/uapi/sound/hdsp.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef __SOUND_HDSP_H
+#define __SOUND_HDSP_H
+
+/*
+ *   Copyright (C) 2003 Thomas Charbonnel (thomas@undata.org)
+ */
+
+#ifdef __linux__
+#include <linux/types.h>
+#endif
+
+#define HDSP_MATRIX_MIXER_SIZE 2048
+
+enum HDSP_IO_Type {
+	Digiface,
+	Multiface,
+	H9652,
+	H9632,
+	RPM,
+	Undefined,
+};
+
+struct hdsp_peak_rms {
+	__u32 input_peaks[26];
+	__u32 playback_peaks[26];
+	__u32 output_peaks[28];
+	__u64 input_rms[26];
+	__u64 playback_rms[26];
+	/* These are only used for H96xx cards */
+	__u64 output_rms[26];
+};
+
+#define SNDRV_HDSP_IOCTL_GET_PEAK_RMS _IOR('H', 0x40, struct hdsp_peak_rms)
+
+struct hdsp_config_info {
+	unsigned char pref_sync_ref;
+	unsigned char wordclock_sync_check;
+	unsigned char spdif_sync_check;
+	unsigned char adatsync_sync_check;
+	unsigned char adat_sync_check[3];
+	unsigned char spdif_in;
+	unsigned char spdif_out;
+	unsigned char spdif_professional;
+	unsigned char spdif_emphasis;
+	unsigned char spdif_nonaudio;
+	unsigned int spdif_sample_rate;
+	unsigned int system_sample_rate;
+	unsigned int autosync_sample_rate;
+	unsigned char system_clock_mode;
+	unsigned char clock_source;
+	unsigned char autosync_ref;
+	unsigned char line_out;
+	unsigned char passthru; 
+	unsigned char da_gain;
+	unsigned char ad_gain;
+	unsigned char phone_gain;
+	unsigned char xlr_breakout_cable;
+	unsigned char analog_extension_board;
+};
+
+#define SNDRV_HDSP_IOCTL_GET_CONFIG_INFO _IOR('H', 0x41, struct hdsp_config_info)
+
+struct hdsp_firmware {
+	void *firmware_data;	/* 24413 x 4 bytes */
+};
+
+#define SNDRV_HDSP_IOCTL_UPLOAD_FIRMWARE _IOW('H', 0x42, struct hdsp_firmware)
+
+struct hdsp_version {
+	enum HDSP_IO_Type io_type;
+	unsigned short firmware_rev;
+};
+
+#define SNDRV_HDSP_IOCTL_GET_VERSION _IOR('H', 0x43, struct hdsp_version)
+
+struct hdsp_mixer {
+	unsigned short matrix[HDSP_MATRIX_MIXER_SIZE];
+};
+
+#define SNDRV_HDSP_IOCTL_GET_MIXER _IOR('H', 0x44, struct hdsp_mixer)
+
+struct hdsp_9632_aeb {
+	int aebi;
+	int aebo;
+};
+
+#define SNDRV_HDSP_IOCTL_GET_9632_AEB _IOR('H', 0x45, struct hdsp_9632_aeb)
+
+#endif /* __SOUND_HDSP_H */