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, 36 insertions, 0 deletions

diff --git a/drivers/scsi/fcoe/libfcoe.h b/drivers/scsi/fcoe/libfcoe.h
new file mode 100644
index 000000000..b8bdfab51
--- /dev/null
+++ b/drivers/scsi/fcoe/libfcoe.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FCOE_LIBFCOE_H_
+#define _FCOE_LIBFCOE_H_
+
+extern unsigned int libfcoe_debug_logging;
+#define LIBFCOE_LOGGING	          0x01 /* General logging, not categorized */
+#define LIBFCOE_FIP_LOGGING       0x02 /* FIP logging */
+#define LIBFCOE_TRANSPORT_LOGGING 0x04 /* FCoE transport logging */
+#define LIBFCOE_SYSFS_LOGGING     0x08 /* fcoe_sysfs logging */
+
+#define LIBFCOE_CHECK_LOGGING(LEVEL, CMD)		\
+do {							\
+	if (unlikely(libfcoe_debug_logging & LEVEL))	\
+		do {					\
+			CMD;				\
+		} while (0);				\
+} while (0)
+
+#define LIBFCOE_DBG(fmt, args...)					\
+	LIBFCOE_CHECK_LOGGING(LIBFCOE_LOGGING,				\
+			      pr_info("libfcoe: " fmt, ##args);)
+
+#define LIBFCOE_FIP_DBG(fip, fmt, args...)				\
+	LIBFCOE_CHECK_LOGGING(LIBFCOE_FIP_LOGGING,			\
+			      pr_info("host%d: fip: " fmt,		\
+				      (fip)->lp->host->host_no, ##args);)
+
+#define LIBFCOE_TRANSPORT_DBG(fmt, args...)				\
+	LIBFCOE_CHECK_LOGGING(LIBFCOE_TRANSPORT_LOGGING,		\
+			      pr_info("%s: " fmt, __func__, ##args);)
+
+#define LIBFCOE_SYSFS_DBG(cdev, fmt, args...)				\
+	LIBFCOE_CHECK_LOGGING(LIBFCOE_SYSFS_LOGGING,			\
+			      pr_info("ctlr_%d: " fmt, cdev->id, ##args);)
+
+#endif /* _FCOE_LIBFCOE_H_ */