[PATCH v3 21/35] debugfs: Make debugfs_cancellation a capability struct

Marco Elver
2025-09-18T14:06:25Z

When compiling include/linux/debugfs.h with CAPABILITY_ANALYSIS enabled,
we can see this error:

./include/linux/debugfs.h:239:17: error: use of undeclared identifier 'cancellation'
239 | void __acquires(cancellation)

Move the __acquires(..) attribute after the declaration, so that the
compiler can see the cancellation function argument, as well as making
struct debugfs_cancellation a real capability to benefit from Clang's
capability analysis.

Signed-off-by: Marco Elver <elver@google.com>
---
include/linux/debugfs.h | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 7cecda29447e..4ee838cf4678 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -239,18 +239,16 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
* @cancel: callback to call
* @cancel_data: extra data for the callback to call
*/
-struct debugfs_cancellation {
+struct_with_capability(debugfs_cancellation) {
struct list_head list;
void (*cancel)(struct dentry *, void *);
void *cancel_data;
};

-void __acquires(cancellation)
-debugfs_enter_cancellation(struct file *file,
- struct debugfs_cancellation *cancellation);
-void __releases(cancellation)
-debugfs_leave_cancellation(struct file *file,
- struct debugfs_cancellation *cancellation);
+void debugfs_enter_cancellation(struct file *file,
+ struct debugfs_cancellation *cancellation) __acquires(cancellation);
+void debugfs_leave_cancellation(struct file *file,
+ struct debugfs_cancellation *cancellation) __releases(cancellation);

#else

--
2.51.0.384.g4c02a37b29-goog