bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/fs/xfs/scrub/bitmap.h b/fs/xfs/scrub/bitmap.h
new file mode 100644
index 000000000..710c1ac5e
--- /dev/null
+++ b/fs/xfs/scrub/bitmap.h
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2018-2023 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_BITMAP_H__
+#define __XFS_SCRUB_BITMAP_H__
+
+/* u64 bitmap */
+
+struct xbitmap64 {
+	struct rb_root_cached	xb_root;
+};
+
+void xbitmap64_init(struct xbitmap64 *bitmap);
+void xbitmap64_destroy(struct xbitmap64 *bitmap);
+
+int xbitmap64_clear(struct xbitmap64 *bitmap, uint64_t start, uint64_t len);
+int xbitmap64_set(struct xbitmap64 *bitmap, uint64_t start, uint64_t len);
+int xbitmap64_disunion(struct xbitmap64 *bitmap, struct xbitmap64 *sub);
+uint64_t xbitmap64_hweight(struct xbitmap64 *bitmap);
+
+/*
+ * Return codes for the bitmap iterator functions are 0 to continue iterating,
+ * and non-zero to stop iterating.  Any non-zero value will be passed up to the
+ * iteration caller.  The special value -ECANCELED can be used to stop
+ * iteration, because neither bitmap iterator ever generates that error code on
+ * its own.  Callers must not modify the bitmap while walking it.
+ */
+typedef int (*xbitmap64_walk_fn)(uint64_t start, uint64_t len, void *priv);
+int xbitmap64_walk(struct xbitmap64 *bitmap, xbitmap64_walk_fn fn,
+		void *priv);
+
+bool xbitmap64_empty(struct xbitmap64 *bitmap);
+bool xbitmap64_test(struct xbitmap64 *bitmap, uint64_t start, uint64_t *len);
+
+/* u32 bitmap */
+
+struct xbitmap32 {
+	struct rb_root_cached	xb_root;
+};
+
+void xbitmap32_init(struct xbitmap32 *bitmap);
+void xbitmap32_destroy(struct xbitmap32 *bitmap);
+
+int xbitmap32_clear(struct xbitmap32 *bitmap, uint32_t start, uint32_t len);
+int xbitmap32_set(struct xbitmap32 *bitmap, uint32_t start, uint32_t len);
+int xbitmap32_disunion(struct xbitmap32 *bitmap, struct xbitmap32 *sub);
+uint32_t xbitmap32_hweight(struct xbitmap32 *bitmap);
+
+/*
+ * Return codes for the bitmap iterator functions are 0 to continue iterating,
+ * and non-zero to stop iterating.  Any non-zero value will be passed up to the
+ * iteration caller.  The special value -ECANCELED can be used to stop
+ * iteration, because neither bitmap iterator ever generates that error code on
+ * its own.  Callers must not modify the bitmap while walking it.
+ */
+typedef int (*xbitmap32_walk_fn)(uint32_t start, uint32_t len, void *priv);
+int xbitmap32_walk(struct xbitmap32 *bitmap, xbitmap32_walk_fn fn,
+		void *priv);
+
+bool xbitmap32_empty(struct xbitmap32 *bitmap);
+bool xbitmap32_test(struct xbitmap32 *bitmap, uint32_t start, uint32_t *len);
+
+uint32_t xbitmap32_count_set_regions(struct xbitmap32 *bitmap);
+
+#endif	/* __XFS_SCRUB_BITMAP_H__ */