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, 67 insertions, 0 deletions

diff --git a/sound/soc/codecs/max9867.h b/sound/soc/codecs/max9867.h
new file mode 100644
index 000000000..b6b880631
--- /dev/null
+++ b/sound/soc/codecs/max9867.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * max9867.h -- MAX9867 ALSA SoC Audio driver
+ *
+ * Copyright 2013-2015 Maxim Integrated Products
+ */
+
+#ifndef _MAX9867_H
+#define _MAX9867_H
+
+/* MAX9867 register space */
+
+#define MAX9867_STATUS        0x00
+#define MAX9867_JACKSTATUS   0x01
+#define MAX9867_AUXHIGH      0x02
+#define MAX9867_AUXLOW       0x03
+#define MAX9867_INTEN        0x04
+#define MAX9867_SYSCLK       0x05
+#define MAX9867_FREQ_MASK    0xF
+#define MAX9867_PSCLK_SHIFT  0x4
+#define MAX9867_PSCLK_WIDTH  0x2
+#define MAX9867_PSCLK_MASK   (0x03<<MAX9867_PSCLK_SHIFT)
+#define MAX9867_PSCLK_10_20  0x1
+#define MAX9867_PSCLK_20_40  0x2
+#define MAX9867_PSCLK_40_60  0x3
+#define MAX9867_AUDIOCLKHIGH	0x06
+#define MAX9867_NI_HIGH_MASK	0x7F
+#define MAX9867_NI_LOW_MASK	0xFE
+#define MAX9867_PLL		(1<<7)
+#define MAX9867_AUDIOCLKLOW	0x07
+#define MAX9867_RAPID_LOCK   0x01
+#define MAX9867_IFC1A        0x08
+#define MAX9867_MASTER       (1<<7)
+#define MAX9867_I2S_DLY      (1<<4)
+#define MAX9867_SDOUT_HIZ    (1<<3)
+#define MAX9867_TDM_MODE     (1<<2)
+#define MAX9867_WCI_MODE     (1<<6)
+#define MAX9867_BCI_MODE     (1<<5)
+#define MAX9867_IFC1B        0x09
+#define MAX9867_IFC1B_BCLK_MASK 7
+#define MAX9867_IFC1B_64X	0x01
+#define MAX9867_IFC1B_48X	0x02
+#define MAX9867_IFC1B_PCLK_2	0x04
+#define MAX9867_IFC1B_PCLK_4	0x05
+#define MAX9867_IFC1B_PCLK_8	0x06
+#define MAX9867_IFC1B_PCLK_16	0x07
+#define MAX9867_CODECFLTR	0x0a
+#define MAX9867_CODECFLTR_MODE	(1<<7)
+#define MAX9867_SIDETONE     0x0b
+#define MAX9867_DACLEVEL     0x0c
+#define MAX9867_ADCLEVEL     0x0d
+#define MAX9867_LEFTLINELVL  0x0e
+#define MAX9867_RIGHTLINELVL 0x0f
+#define MAX9867_LEFTVOL      0x10
+#define MAX9867_RIGHTVOL     0x11
+#define MAX9867_LEFTMICGAIN  0x12
+#define MAX9867_RIGHTMICGAIN 0x13
+#define MAX9867_INPUTCONFIG  0x14
+#define MAX9867_MICCONFIG    0x15
+#define MAX9867_MODECONFIG   0x16
+#define MAX9867_PWRMAN       0x17
+#define MAX9867_PWRMAN_SHDN  (1<<7)
+#define MAX9867_REVISION     0xff
+
+#define MAX9867_CACHEREGNUM 10
+
+#endif