jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <AK/StringView.h>
8#include <Kernel/FileSystem/Custody.h>
9#include <Kernel/FileSystem/VirtualFileSystem.h>
10#include <Kernel/Process.h>
11
12namespace Kernel {
13
14ErrorOr<FlatPtr> Process::sys$realpath(Userspace<Syscall::SC_realpath_params const*> user_params)
15{
16 VERIFY_NO_PROCESS_BIG_LOCK(this);
17 TRY(require_promise(Pledge::rpath));
18 auto params = TRY(copy_typed_from_user(user_params));
19
20 auto path = TRY(get_syscall_path_argument(params.path));
21 auto custody = TRY(VirtualFileSystem::the().resolve_path(credentials(), path->view(), current_directory()));
22 auto absolute_path = TRY(custody->try_serialize_absolute_path());
23
24 size_t ideal_size = absolute_path->length() + 1;
25 auto size_to_copy = min(ideal_size, params.buffer.size);
26 TRY(copy_to_user(params.buffer.data, absolute_path->characters(), size_to_copy));
27 // Note: we return the whole size here, not the copied size.
28 return ideal_size;
29};
30
31}