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, 154 insertions, 0 deletions

diff --git a/sound/soc/codecs/max9860.h b/sound/soc/codecs/max9860.h
new file mode 100644
index 000000000..e07b905ea
--- /dev/null
+++ b/sound/soc/codecs/max9860.h
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Driver for the MAX9860 Mono Audio Voice Codec
+ *
+ * Author: Peter Rosin <peda@axentia.s>
+ *         Copyright 2016 Axentia Technologies
+ */
+
+#ifndef _SND_SOC_MAX9860
+#define _SND_SOC_MAX9860
+
+#define MAX9860_INTRSTATUS   0x00
+#define MAX9860_MICREADBACK  0x01
+#define MAX9860_INTEN        0x02
+#define MAX9860_SYSCLK       0x03
+#define MAX9860_AUDIOCLKHIGH 0x04
+#define MAX9860_AUDIOCLKLOW  0x05
+#define MAX9860_IFC1A        0x06
+#define MAX9860_IFC1B        0x07
+#define MAX9860_VOICEFLTR    0x08
+#define MAX9860_DACATTN      0x09
+#define MAX9860_ADCLEVEL     0x0a
+#define MAX9860_DACGAIN      0x0b
+#define MAX9860_MICGAIN      0x0c
+#define MAX9860_RESERVED     0x0d
+#define MAX9860_MICADC       0x0e
+#define MAX9860_NOISEGATE    0x0f
+#define MAX9860_PWRMAN       0x10
+#define MAX9860_REVISION     0xff
+
+#define MAX9860_MAX_REGISTER 0xff
+
+/* INTRSTATUS */
+#define MAX9860_CLD          0x80
+#define MAX9860_SLD          0x40
+#define MAX9860_ULK          0x20
+
+/* MICREADBACK */
+#define MAX9860_NG           0xe0
+#define MAX9860_AGC          0x1f
+
+/* INTEN */
+#define MAX9860_ICLD         0x80
+#define MAX9860_ISLD         0x40
+#define MAX9860_IULK         0x20
+
+/* SYSCLK */
+#define MAX9860_PSCLK        0x30
+#define MAX9860_PSCLK_OFF    0x00
+#define MAX9860_PSCLK_SHIFT  4
+#define MAX9860_FREQ         0x06
+#define MAX9860_FREQ_NORMAL  0x00
+#define MAX9860_FREQ_12MHZ   0x02
+#define MAX9860_FREQ_13MHZ   0x04
+#define MAX9860_FREQ_19_2MHZ 0x06
+#define MAX9860_16KHZ        0x01
+
+/* AUDIOCLKHIGH */
+#define MAX9860_PLL          0x80
+#define MAX9860_NHI          0x7f
+
+/* AUDIOCLKLOW */
+#define MAX9860_NLO          0xff
+
+/* IFC1A */
+#define MAX9860_MASTER       0x80
+#define MAX9860_WCI          0x40
+#define MAX9860_DBCI         0x20
+#define MAX9860_DDLY         0x10
+#define MAX9860_HIZ          0x08
+#define MAX9860_TDM          0x04
+
+/* IFC1B */
+#define MAX9860_ABCI         0x20
+#define MAX9860_ADLY         0x10
+#define MAX9860_ST           0x08
+#define MAX9860_BSEL         0x07
+#define MAX9860_BSEL_OFF     0x00
+#define MAX9860_BSEL_64X     0x01
+#define MAX9860_BSEL_48X     0x02
+#define MAX9860_BSEL_PCLK_2  0x04
+#define MAX9860_BSEL_PCLK_4  0x05
+#define MAX9860_BSEL_PCLK_8  0x06
+#define MAX9860_BSEL_PCLK_16 0x07
+
+/* VOICEFLTR */
+#define MAX9860_AVFLT        0xf0
+#define MAX9860_AVFLT_SHIFT  4
+#define MAX9860_AVFLT_COUNT  6
+#define MAX9860_DVFLT        0x0f
+#define MAX9860_DVFLT_SHIFT  0
+#define MAX9860_DVFLT_COUNT  6
+
+/* DACATTN */
+#define MAX9860_DVA          0xfe
+#define MAX9860_DVA_SHIFT    1
+#define MAX9860_DVA_MUTE     0x5e
+
+/* ADCLEVEL */
+#define MAX9860_ADCRL        0xf0
+#define MAX9860_ADCRL_SHIFT  4
+#define MAX9860_ADCLL        0x0f
+#define MAX9860_ADCLL_SHIFT  0
+#define MAX9860_ADCxL_MIN    15
+
+/* DACGAIN */
+#define MAX9860_DVG          0x60
+#define MAX9860_DVG_SHIFT    5
+#define MAX9860_DVG_MAX      3
+#define MAX9860_DVST         0x1f
+#define MAX9860_DVST_SHIFT   0
+#define MAX9860_DVST_MIN     31
+
+/* MICGAIN */
+#define MAX9860_PAM          0x60
+#define MAX9860_PAM_SHIFT    5
+#define MAX9860_PAM_MAX      3
+#define MAX9860_PGAM         0x1f
+#define MAX9860_PGAM_SHIFT   0
+#define MAX9860_PGAM_MIN     20
+
+/* MICADC */
+#define MAX9860_AGCSRC       0x80
+#define MAX9860_AGCSRC_SHIFT 7
+#define MAX9860_AGCSRC_COUNT 2
+#define MAX9860_AGCRLS       0x70
+#define MAX9860_AGCRLS_SHIFT 4
+#define MAX9860_AGCRLS_COUNT 8
+#define MAX9860_AGCATK       0x0c
+#define MAX9860_AGCATK_SHIFT 2
+#define MAX9860_AGCATK_COUNT 4
+#define MAX9860_AGCHLD       0x03
+#define MAX9860_AGCHLD_OFF   0x00
+#define MAX9860_AGCHLD_SHIFT 0
+#define MAX9860_AGCHLD_COUNT 4
+
+/* NOISEGATE */
+#define MAX9860_ANTH         0xf0
+#define MAX9860_ANTH_SHIFT   4
+#define MAX9860_ANTH_MAX     15
+#define MAX9860_AGCTH        0x0f
+#define MAX9860_AGCTH_SHIFT  0
+#define MAX9860_AGCTH_MIN    15
+
+/* PWRMAN */
+#define MAX9860_SHDN         0x80
+#define MAX9860_DACEN        0x08
+#define MAX9860_DACEN_SHIFT  3
+#define MAX9860_ADCLEN       0x02
+#define MAX9860_ADCLEN_SHIFT 1
+#define MAX9860_ADCREN       0x01
+#define MAX9860_ADCREN_SHIFT 0
+
+#endif /* _SND_SOC_MAX9860 */