serenity/Kernel/Syscalls/ftruncate.cpp
Andreas Kling 48a0b31c47 Kernel: Make copy_{from,to}_user() return KResult and use TRY()
This makes EFAULT propagation flow much more naturally. :^)
2021-09-05 17:38:37 +02:00

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/*
* 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)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE(stdio);
off_t length;
TRY(copy_from_user(&length, userspace_length));
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));
}
}