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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 10:43:19 +0200
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 07:58:36 -0700
commit6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch)
tree58e8288fead484f6755ad0815fc74c3742663761 /drivers/md/bcache/debug.h
downloadlinux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.tar.gz
linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.zip
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>
Diffstat (limited to 'drivers/md/bcache/debug.h')
-rw-r--r--drivers/md/bcache/debug.h35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h
new file mode 100644
index 000000000..fb3d4dff4
--- /dev/null
+++ b/drivers/md/bcache/debug.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHE_DEBUG_H
+#define _BCACHE_DEBUG_H
+
+struct bio;
+struct cached_dev;
+struct cache_set;
+
+#ifdef CONFIG_BCACHE_DEBUG
+
+void bch_btree_verify(struct btree *b);
+void bch_data_verify(struct cached_dev *dc, struct bio *bio);
+
+#define expensive_debug_checks(c) ((c)->expensive_debug_checks)
+#define key_merging_disabled(c) ((c)->key_merging_disabled)
+#define bypass_torture_test(d) ((d)->bypass_torture_test)
+
+#else /* DEBUG */
+
+static inline void bch_btree_verify(struct btree *b) {}
+static inline void bch_data_verify(struct cached_dev *dc, struct bio *bio) {}
+
+#define expensive_debug_checks(c) 0
+#define key_merging_disabled(c) 0
+#define bypass_torture_test(d) 0
+
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+void bch_debug_init_cache_set(struct cache_set *c);
+#else
+static inline void bch_debug_init_cache_set(struct cache_set *c) {}
+#endif
+
+#endif