ladybird/Kernel/Syscalls/lseek.cpp
Andreas Kling a9204510a4 Kernel: Make file description lookup return KResultOr
Instead of checking it at every call site (to generate EBADF), we make
file_description(fd) return a KResultOr<NonnullRefPtr<FileDescription>>.

This allows us to wrap all the calls in TRY(). :^)

The only place that got a little bit messier from this is sys$mount(),
and there's a whole bunch of things there in need of cleanup.
2021-09-05 18:36:13 +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$lseek(int fd, Userspace<off_t*> userspace_offset, int whence)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE(stdio);
auto description = TRY(fds().file_description(fd));
off_t offset;
TRY(copy_from_user(&offset, userspace_offset));
auto seek_result = TRY(description->seek(offset, whence));
return copy_to_user(userspace_offset, &seek_result);
}
}