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, 38 insertions, 0 deletions

diff --git a/fs/btrfs/super.h b/fs/btrfs/super.h
new file mode 100644
index 000000000..f85f8a8a7
--- /dev/null
+++ b/fs/btrfs/super.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_SUPER_H
+#define BTRFS_SUPER_H
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include "fs.h"
+
+struct super_block;
+struct btrfs_fs_info;
+
+bool btrfs_check_options(const struct btrfs_fs_info *info,
+			 unsigned long long *mount_opt,
+			 unsigned long flags);
+int btrfs_sync_fs(struct super_block *sb, int wait);
+char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
+					  u64 subvol_objectid);
+void btrfs_set_free_space_cache_settings(struct btrfs_fs_info *fs_info);
+
+static inline struct btrfs_fs_info *btrfs_sb(const struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline void btrfs_set_sb_rdonly(struct super_block *sb)
+{
+	sb->s_flags |= SB_RDONLY;
+	set_bit(BTRFS_FS_STATE_RO, &btrfs_sb(sb)->fs_state);
+}
+
+static inline void btrfs_clear_sb_rdonly(struct super_block *sb)
+{
+	sb->s_flags &= ~SB_RDONLY;
+	clear_bit(BTRFS_FS_STATE_RO, &btrfs_sb(sb)->fs_state);
+}
+
+#endif