/* * Copyright (c) 2018-2021, Andreas Kling <andreas@ladybird.org> * Copyright (c) 2023, kleines Filmröllchen <filmroellchen@serenityos.org> * * SPDX-License-Identifier: BSD-2-Clause */ #include <AK/ScopeGuard.h> #include <LibCore/File.h> #include <LibCore/MappedFile.h> #include <LibCore/System.h> #include <sys/mman.h> namespace Core { ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map(StringView path, Mode mode) { auto const file_mode = mode == Mode::ReadOnly ? O_RDONLY : O_RDWR; auto fd = TRY(Core::System::open(path, file_mode | O_CLOEXEC, 0)); return map_from_fd_and_close(fd, path, mode); } ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_file(NonnullOwnPtr<Core::File> stream, StringView path) { return map_from_fd_and_close(stream->leak_fd(Badge<MappedFile> {}), path); } ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_fd_and_close(int fd, [[maybe_unused]] StringView path, Mode mode) { ScopeGuard fd_close_guard = [fd] { (void)System::close(fd); }; auto stat = TRY(Core::System::fstat(fd)); auto size = stat.st_size; int protection; int flags; switch (mode) { case Mode::ReadOnly: protection = PROT_READ; flags = MAP_SHARED; break; case Mode::ReadWrite: protection = PROT_READ | PROT_WRITE; // Don't map a read-write mapping shared as a precaution. flags = MAP_PRIVATE; break; } auto* ptr = TRY(Core::System::mmap(nullptr, size, protection, flags, fd, 0, 0, path)); return adopt_own(*new MappedFile(ptr, size, mode)); } MappedFile::MappedFile(void* ptr, size_t size, Mode mode) : FixedMemoryStream(Bytes { ptr, size }, mode) , m_data(ptr) , m_size(size) { } MappedFile::~MappedFile() { auto res = Core::System::munmap(m_data, m_size); if (res.is_error()) dbgln("Failed to unmap MappedFile (@ {:p}): {}", m_data, res.error()); } }