ladybird/Kernel/Syscalls/open.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

91 lines
2.4 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$open(Userspace<const Syscall::SC_open_params*> user_params)
{
Syscall::SC_open_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
int dirfd = params.dirfd;
int options = params.options;
u16 mode = params.mode;
if (options & O_NOFOLLOW_NOERROR)
return EINVAL;
if (options & O_UNLINK_INTERNAL)
return EINVAL;
if (options & O_WRONLY)
REQUIRE_PROMISE(wpath);
else if (options & O_RDONLY)
REQUIRE_PROMISE(rpath);
if (options & O_CREAT)
REQUIRE_PROMISE(cpath);
// Ignore everything except permission bits.
mode &= 0777;
auto path = get_syscall_path_argument(params.path);
if (path.is_error())
return path.error();
dbgln_if(IO_DEBUG, "sys$open(dirfd={}, path='{}', options={}, mode={})", dirfd, path.value()->view(), options, mode);
int fd = m_fds.allocate();
if (fd < 0)
return fd;
RefPtr<Custody> base;
if (dirfd == AT_FDCWD) {
base = current_directory();
} else {
auto base_description = fds().file_description(dirfd);
if (!base_description)
return EBADF;
if (!base_description->is_directory())
return ENOTDIR;
if (!base_description->custody())
return EINVAL;
base = base_description->custody();
}
auto result = VFS::the().open(path.value()->view(), options, mode & ~umask(), *base);
if (result.is_error())
return result.error();
auto description = result.value();
if (description->inode() && description->inode()->socket())
return ENXIO;
u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
m_fds[fd].set(move(description), fd_flags);
return fd;
}
KResultOr<FlatPtr> Process::sys$close(int fd)
{
REQUIRE_PROMISE(stdio);
auto description = fds().file_description(fd);
dbgln_if(IO_DEBUG, "sys$close({}) {}", fd, description.ptr());
if (!description)
return EBADF;
int rc = description->close();
m_fds[fd] = {};
return rc;
}
}