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, 79 insertions, 0 deletions

diff --git a/include/sound/hda_chmap.h b/include/sound/hda_chmap.h
new file mode 100644
index 000000000..e508f3192
--- /dev/null
+++ b/include/sound/hda_chmap.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * For multichannel support
+ */
+
+#ifndef __SOUND_HDA_CHMAP_H
+#define __SOUND_HDA_CHMAP_H
+
+#include <sound/pcm.h>
+#include <sound/hdaudio.h>
+
+
+#define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80
+
+struct hdac_cea_channel_speaker_allocation {
+	int ca_index;
+	int speakers[8];
+
+	/* derived values, just for convenience */
+	int channels;
+	int spk_mask;
+};
+struct hdac_chmap;
+
+struct hdac_chmap_ops {
+	/*
+	 * Helpers for producing the channel map TLVs. These can be overridden
+	 * for devices that have non-standard mapping requirements.
+	 */
+	int (*chmap_cea_alloc_validate_get_type)(struct hdac_chmap *chmap,
+		struct hdac_cea_channel_speaker_allocation *cap, int channels);
+	void (*cea_alloc_to_tlv_chmap)(struct hdac_chmap *hchmap,
+		struct hdac_cea_channel_speaker_allocation *cap,
+		unsigned int *chmap, int channels);
+
+	/* check that the user-given chmap is supported */
+	int (*chmap_validate)(struct hdac_chmap *hchmap, int ca,
+			int channels, unsigned char *chmap);
+
+	int (*get_spk_alloc)(struct hdac_device *hdac, int pcm_idx);
+
+	void (*get_chmap)(struct hdac_device *hdac, int pcm_idx,
+					unsigned char *chmap);
+	void (*set_chmap)(struct hdac_device *hdac, int pcm_idx,
+			unsigned char *chmap, int prepared);
+	bool (*is_pcm_attached)(struct hdac_device *hdac, int pcm_idx);
+
+	/* get and set channel assigned to each HDMI ASP (audio sample packet) slot */
+	int (*pin_get_slot_channel)(struct hdac_device *codec,
+			hda_nid_t pin_nid, int asp_slot);
+	int (*pin_set_slot_channel)(struct hdac_device *codec,
+			hda_nid_t pin_nid, int asp_slot, int channel);
+	void (*set_channel_count)(struct hdac_device *codec,
+				hda_nid_t cvt_nid, int chs);
+};
+
+struct hdac_chmap {
+	unsigned int channels_max; /* max over all cvts */
+	struct hdac_chmap_ops ops;
+	struct hdac_device *hdac;
+};
+
+void snd_hdac_register_chmap_ops(struct hdac_device *hdac,
+				struct hdac_chmap *chmap);
+int snd_hdac_channel_allocation(struct hdac_device *hdac, int spk_alloc,
+			int channels, bool chmap_set,
+			bool non_pcm, unsigned char *map);
+int snd_hdac_get_active_channels(int ca);
+void snd_hdac_setup_channel_mapping(struct hdac_chmap *chmap,
+		       hda_nid_t pin_nid, bool non_pcm, int ca,
+		       int channels, unsigned char *map,
+		       bool chmap_set);
+void snd_hdac_print_channel_allocation(int spk_alloc, char *buf, int buflen);
+struct hdac_cea_channel_speaker_allocation *snd_hdac_get_ch_alloc_from_ca(int ca);
+int snd_hdac_chmap_to_spk_mask(unsigned char c);
+int snd_hdac_spk_to_chmap(int spk);
+int snd_hdac_add_chmap_ctls(struct snd_pcm *pcm, int pcm_idx,
+				struct hdac_chmap *chmap);
+#endif /* __SOUND_HDA_CHMAP_H */