static int binder_open()

in binder.c [5350:5442]

• 70 lines of code
• 9 McCabe index (conditional complexity)

static int binder_open(struct inode *nodp, struct file *filp)
{
	struct binder_proc *proc, *itr;
	struct binder_device *binder_dev;
	struct binderfs_info *info;
	struct dentry *binder_binderfs_dir_entry_proc = NULL;
	bool existing_pid = false;

	binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
		     current->group_leader->pid, current->pid);

	proc = kzalloc(sizeof(*proc), GFP_KERNEL);
	if (proc == NULL)
		return -ENOMEM;
	spin_lock_init(&proc->inner_lock);
	spin_lock_init(&proc->outer_lock);
	get_task_struct(current->group_leader);
	proc->tsk = current->group_leader;
	proc->cred = get_cred(filp->f_cred);
	INIT_LIST_HEAD(&proc->todo);
	init_waitqueue_head(&proc->freeze_wait);
	proc->default_priority = task_nice(current);
	/* binderfs stashes devices in i_private */
	if (is_binderfs_device(nodp)) {
		binder_dev = nodp->i_private;
		info = nodp->i_sb->s_fs_info;
		binder_binderfs_dir_entry_proc = info->proc_log_dir;
	} else {
		binder_dev = container_of(filp->private_data,
					  struct binder_device, miscdev);
	}
	refcount_inc(&binder_dev->ref);
	proc->context = &binder_dev->context;
	binder_alloc_init(&proc->alloc);

	binder_stats_created(BINDER_STAT_PROC);
	proc->pid = current->group_leader->pid;
	INIT_LIST_HEAD(&proc->delivered_death);
	INIT_LIST_HEAD(&proc->waiting_threads);
	filp->private_data = proc;

	mutex_lock(&binder_procs_lock);
	hlist_for_each_entry(itr, &binder_procs, proc_node) {
		if (itr->pid == proc->pid) {
			existing_pid = true;
			break;
		}
	}
	hlist_add_head(&proc->proc_node, &binder_procs);
	mutex_unlock(&binder_procs_lock);

	if (binder_debugfs_dir_entry_proc && !existing_pid) {
		char strbuf[11];

		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
		/*
		 * proc debug entries are shared between contexts.
		 * Only create for the first PID to avoid debugfs log spamming
		 * The printing code will anyway print all contexts for a given
		 * PID so this is not a problem.
		 */
		proc->debugfs_entry = debugfs_create_file(strbuf, 0444,
			binder_debugfs_dir_entry_proc,
			(void *)(unsigned long)proc->pid,
			&proc_fops);
	}

	if (binder_binderfs_dir_entry_proc && !existing_pid) {
		char strbuf[11];
		struct dentry *binderfs_entry;

		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
		/*
		 * Similar to debugfs, the process specific log file is shared
		 * between contexts. Only create for the first PID.
		 * This is ok since same as debugfs, the log file will contain
		 * information on all contexts of a given PID.
		 */
		binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc,
			strbuf, &proc_fops, (void *)(unsigned long)proc->pid);
		if (!IS_ERR(binderfs_entry)) {
			proc->binderfs_entry = binderfs_entry;
		} else {
			int error;

			error = PTR_ERR(binderfs_entry);
			pr_warn("Unable to create file %s in binderfs (error %d)\n",
				strbuf, error);
		}
	}

	return 0;
}