serenity/Kernel/Syscalls/fcntl.cpp
Liav A 7c87891c06 Kernel: Don't copy a Vector<FileDescriptionAndFlags>
Instead of copying a Vector everytime we need to enumerate a Process'
file descriptions, we can just temporarily lock so it won't change.
2021-06-29 20:53:59 +02:00

52 lines
1.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$fcntl(int fd, int cmd, u32 arg)
{
REQUIRE_PROMISE(stdio);
dbgln_if(IO_DEBUG, "sys$fcntl: fd={}, cmd={}, arg={}", fd, cmd, arg);
auto description = fds().file_description(fd);
if (!description)
return EBADF;
// NOTE: The FD flags are not shared between FileDescription objects.
// This means that dup() doesn't copy the FD_CLOEXEC flag!
switch (cmd) {
case F_DUPFD: {
int arg_fd = (int)arg;
if (arg_fd < 0)
return EINVAL;
int new_fd = fds().allocate(arg_fd);
if (new_fd < 0)
return new_fd;
m_fds[new_fd].set(*description);
return new_fd;
}
case F_GETFD:
return m_fds[fd].flags();
case F_SETFD:
m_fds[fd].set_flags(arg);
break;
case F_GETFL:
return description->file_flags();
case F_SETFL:
description->set_file_flags(arg);
break;
case F_ISTTY:
return description->is_tty();
default:
return EINVAL;
}
return 0;
}
}