diff options
Diffstat (limited to 'js/xpconnect/loader/AutoMemMap.cpp')
-rw-r--r-- | js/xpconnect/loader/AutoMemMap.cpp | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/js/xpconnect/loader/AutoMemMap.cpp b/js/xpconnect/loader/AutoMemMap.cpp new file mode 100644 index 0000000000..f8c75ea445 --- /dev/null +++ b/js/xpconnect/loader/AutoMemMap.cpp @@ -0,0 +1,157 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "AutoMemMap.h" +#include "ScriptPreloader-inl.h" + +#include "mozilla/Unused.h" +#include "mozilla/ipc/FileDescriptor.h" +#include "nsIFile.h" + +#include <private/pprio.h> + +namespace mozilla { +namespace loader { + +using namespace mozilla::ipc; + +AutoMemMap::~AutoMemMap() { reset(); } + +FileDescriptor AutoMemMap::cloneFileDescriptor() const { + if (fd.get()) { + auto handle = + FileDescriptor::PlatformHandleType(PR_FileDesc2NativeHandle(fd.get())); + return FileDescriptor(handle); + } + return FileDescriptor(); +} + +Result<Ok, nsresult> AutoMemMap::init(nsIFile* file, int flags, int mode, + PRFileMapProtect prot) { + MOZ_ASSERT(!fd); + + MOZ_TRY(file->OpenNSPRFileDesc(flags, mode, &fd.rwget())); + + return initInternal(prot); +} + +Result<Ok, nsresult> AutoMemMap::init(const FileDescriptor& file, + PRFileMapProtect prot, size_t maybeSize) { + MOZ_ASSERT(!fd); + if (!file.IsValid()) { + return Err(NS_ERROR_INVALID_ARG); + } + + auto handle = file.ClonePlatformHandle(); + + fd = PR_ImportFile(PROsfd(handle.get())); + if (!fd) { + return Err(NS_ERROR_FAILURE); + } + Unused << handle.release(); + + return initInternal(prot, maybeSize); +} + +Result<Ok, nsresult> AutoMemMap::initInternal(PRFileMapProtect prot, + size_t maybeSize) { + MOZ_ASSERT(!fileMap); + MOZ_ASSERT(!addr); + + if (maybeSize > 0) { + // Some OSes' shared memory objects can't be stat()ed, either at + // all (Android) or without loosening the sandbox (Mac) so just + // use the size. + size_ = maybeSize; + } else { + // But if we don't have the size, assume it's a regular file and + // ask for it. + PRFileInfo64 fileInfo; + MOZ_TRY(PR_GetOpenFileInfo64(fd.get(), &fileInfo)); + + if (fileInfo.size > UINT32_MAX) { + return Err(NS_ERROR_INVALID_ARG); + } + size_ = fileInfo.size; + } + + fileMap = PR_CreateFileMap(fd, 0, prot); + if (!fileMap) { + return Err(NS_ERROR_FAILURE); + } + + addr = PR_MemMap(fileMap, 0, size_); + if (!addr) { + return Err(NS_ERROR_FAILURE); + } + + return Ok(); +} + +#ifdef XP_WIN + +Result<Ok, nsresult> AutoMemMap::initWithHandle(const FileDescriptor& file, + size_t size, + PRFileMapProtect prot) { + MOZ_ASSERT(!fd); + MOZ_ASSERT(!handle_); + if (!file.IsValid()) { + return Err(NS_ERROR_INVALID_ARG); + } + + handle_ = file.ClonePlatformHandle().release(); + + MOZ_ASSERT(!addr); + + size_ = size; + + addr = MapViewOfFile( + handle_, prot == PR_PROT_READONLY ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS, + 0, 0, size); + if (!addr) { + return Err(NS_ERROR_FAILURE); + } + + return Ok(); +} + +FileDescriptor AutoMemMap::cloneHandle() const { + return FileDescriptor(handle_); +} + +#else + +Result<Ok, nsresult> AutoMemMap::initWithHandle(const FileDescriptor& file, + size_t size, + PRFileMapProtect prot) { + MOZ_DIAGNOSTIC_ASSERT(size > 0); + return init(file, prot, size); +} + +FileDescriptor AutoMemMap::cloneHandle() const { return cloneFileDescriptor(); } + +#endif + +void AutoMemMap::reset() { + if (addr && !persistent_) { + Unused << NS_WARN_IF(PR_MemUnmap(addr, size()) != PR_SUCCESS); + addr = nullptr; + } + if (fileMap) { + Unused << NS_WARN_IF(PR_CloseFileMap(fileMap) != PR_SUCCESS); + fileMap = nullptr; + } +#ifdef XP_WIN + if (handle_) { + CloseHandle(handle_); + handle_ = nullptr; + } +#endif + fd.dispose(); +} + +} // namespace loader +} // namespace mozilla |