Re: [PATCH v2 1/3] fs: Introduce task path helpers

On Tue, Sep 22, 2026 at 3:21 AM Jann Horn [off-list ref] wrote:

On Mon, Aug 31, 2026 at 4:59 AM Chen Linxuan via B4 Relay
[off-list ref] wrote:

quoted

Introduce helpers that acquire a referenced struct path for a task's
executable, root, and working directory. Reuse them for procfs task
links and AppArmor executable-path handling instead of duplicating file
and path reference handling at each call site.

[...]

quoted

+/**
+ * get_task_exe_path - acquire a reference to the task's executable path
+ * @task: The task.
+ * @exe_path: The task's executable path.
+ *
+ * Returns 0 if the task has an executable path, or -ENOENT if it does not.
+ * The caller must release the path through path_put() on success.
+ */
+int get_task_exe_path(struct task_struct *task, struct path *exe_path)
+{
+       struct file *exe_file = get_task_exe_file(task);
+
+       if (!exe_file)
+               return -ENOENT;
+
+       *exe_path = exe_file->f_path;
+       path_get(exe_path);
+       fput(exe_file);
+       return 0;
+}

[...]

quoted

 static const char *get_current_exe_path(char *buffer, int buffer_size)
 {
-       struct file *exe_file;
-       struct path p;
+       struct path p __free(path_put) = {};
        const char *path_str;

-       exe_file = get_task_exe_file(current);
-       if (!exe_file)
+       if (get_task_exe_path(current, &p))
                return ERR_PTR(-ENOENT);

This assumes that when get_task_exe_path() fails, it doesn't set
members of the path argument to non-NULL values. That should be noted
in a comment above get_task_exe_path().

Will be updated in V3.