ladybird/Kernel/Syscalls/ftruncate.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

28 lines
684 B
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$ftruncate(int fd, Userspace<off_t*> userspace_length)
{
REQUIRE_PROMISE(stdio);
off_t length;
if (!copy_from_user(&length, userspace_length))
return EFAULT;
if (length < 0)
return EINVAL;
auto description = fds().file_description(fd);
if (!description)
return EBADF;
if (!description->is_writable())
return EBADF;
return description->truncate(static_cast<u64>(length));
}
}