workqueue: drop spurious '*' from print_worker_info() fn declaration

[ Upstream commit 611583a76e ]

print_worker_info() declares its local 'fn' as work_func_t * but
worker->current_func has type work_func_t (a function pointer). The
extra level of indirection is wrong and only happens to be harmless
today because every supported Linux architecture has
sizeof(work_func_t) == sizeof(work_func_t *):
copy_from_kernel_nofault() reads the correct number of bytes by
accident, and %ps still resolves the printed address because the
stored value is the function address regardless of declared type.

On any future ABI where sizeof(void (*)()) differs from
sizeof(void *), the nofault copy would transfer the wrong number of
bytes and the subsequent %ps would print an incorrect address.

Match the field type so the intent is explicit and the code does not
silently rely on equal pointer sizes.

Fixes: 3d1cb2059d ("workqueue: include workqueue info when printing debug dump of a worker task")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

kernel/workqueue.c

@@ -5119,7 +5119,7 @@ EXPORT_SYMBOL_GPL(set_worker_desc);
  */
 void print_worker_info(const char *log_lvl, struct task_struct *task)
 {
-	work_func_t *fn = NULL;
+	work_func_t fn = NULL;
 	char name[WQ_NAME_LEN] = { };
 	char desc[WORKER_DESC_LEN] = { };
 	struct pool_workqueue *pwq = NULL;