ladybird/Kernel/Syscalls/dup2.cpp

30 lines
863 B
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Tasks/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$dup2(int old_fd, int new_fd)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
auto description = TRY(fds.open_file_description(old_fd));
if (old_fd == new_fd)
return new_fd;
if (new_fd < 0 || static_cast<size_t>(new_fd) >= OpenFileDescriptions::max_open())
return EINVAL;
if (!fds.m_fds_metadatas[new_fd].is_allocated())
fds.m_fds_metadatas[new_fd].allocate();
fds[new_fd].set(move(description));
return new_fd;
});
}
}