ladybird/Kernel/Syscalls/readlink.cpp
Gunnar Beutner 2a78bf8596 Kernel: Fix the return type for syscalls
The Process::Handler type has KResultOr<FlatPtr> as its return type.
Using a different return type with an equally-sized template parameter
sort of works but breaks once that condition is no longer true, e.g.
for KResultOr<int> on x86_64.

Ideally the syscall handlers would also take FlatPtrs as their args
so we can get rid of the reinterpret_cast for the function pointer
but I didn't quite feel like cleaning that up as well.
2021-06-28 22:29:28 +02:00

46 lines
1.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringView.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$readlink(Userspace<const Syscall::SC_readlink_params*> user_params)
{
REQUIRE_PROMISE(rpath);
Syscall::SC_readlink_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
auto path = get_syscall_path_argument(params.path);
if (path.is_error())
return path.error();
auto result = VFS::the().open(path.value()->view(), O_RDONLY | O_NOFOLLOW_NOERROR, 0, current_directory());
if (result.is_error())
return result.error();
auto description = result.value();
if (!description->metadata().is_symlink())
return EINVAL;
auto contents = description->read_entire_file();
if (contents.is_error())
return contents.error();
auto& link_target = *contents.value();
auto size_to_copy = min(link_target.size(), params.buffer.size);
if (!copy_to_user(params.buffer.data, link_target.data(), size_to_copy))
return EFAULT;
// Note: we return the whole size here, not the copied size.
return link_target.size();
}
}