ladybird/Kernel/Syscalls/chdir.cpp
Andreas Kling 23822febd2 Kernel: Mark sys$fchdir() as not needing the big lock
This syscall doesn't access any data that was implicitly protected by
the big lock.
2022-03-08 00:19:49 +01:00

56 lines
1.7 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$chdir(Userspace<const char*> user_path, size_t path_length)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::rpath));
auto path = TRY(get_syscall_path_argument(user_path, path_length));
return m_current_directory.with([&](auto& current_directory) -> ErrorOr<FlatPtr> {
current_directory = TRY(VirtualFileSystem::the().open_directory(path->view(), *current_directory));
return 0;
});
}
ErrorOr<FlatPtr> Process::sys$fchdir(int fd)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
auto description = TRY(open_file_description(fd));
if (!description->is_directory())
return ENOTDIR;
if (!description->metadata().may_execute(*this))
return EACCES;
m_current_directory.with([&](auto& current_directory) {
current_directory = description->custody();
});
return 0;
}
ErrorOr<FlatPtr> Process::sys$getcwd(Userspace<char*> buffer, size_t size)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::rpath));
if (size > NumericLimits<ssize_t>::max())
return EINVAL;
auto path = TRY(current_directory()->try_serialize_absolute_path());
size_t ideal_size = path->length() + 1;
auto size_to_copy = min(ideal_size, size);
TRY(copy_to_user(buffer, path->characters(), size_to_copy));
// Note: we return the whole size here, not the copied size.
return ideal_size;
}
}