ladybird/Kernel/Syscalls/anon_create.cpp
Liav A 5331d243c6 Kernel/Syscall: Make anon_create to not use Process::allocate_fd method
Instead, allocate when acquiring the lock on m_fds struct, which is
safer to do in terms of safely mutating the m_fds struct, because we
don't use the big process lock in this syscall.
2022-08-21 10:56:48 +01:00

46 lines
1.2 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/AnonymousFile.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$anon_create(size_t size, int options)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
if (!size)
return EINVAL;
if (size % PAGE_SIZE)
return EINVAL;
if (size > NumericLimits<ssize_t>::max())
return EINVAL;
auto vmobject = TRY(Memory::AnonymousVMObject::try_create_purgeable_with_size(size, AllocationStrategy::AllocateNow));
auto anon_file = TRY(AnonymousFile::try_create(move(vmobject)));
auto description = TRY(OpenFileDescription::try_create(move(anon_file)));
description->set_writable(true);
description->set_readable(true);
u32 fd_flags = 0;
if (options & O_CLOEXEC)
fd_flags |= FD_CLOEXEC;
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
auto new_fd = TRY(fds.allocate());
fds[new_fd.fd].set(move(description), fd_flags);
return new_fd.fd;
});
}
}