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Diffstat (limited to 'tools/profiler/lul/AutoObjectMapper.cpp')
-rw-r--r-- | tools/profiler/lul/AutoObjectMapper.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/tools/profiler/lul/AutoObjectMapper.cpp b/tools/profiler/lul/AutoObjectMapper.cpp new file mode 100644 index 000000000..a5dc902fd --- /dev/null +++ b/tools/profiler/lul/AutoObjectMapper.cpp @@ -0,0 +1,207 @@ +/* -*- 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 <sys/mman.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#include "mozilla/Assertions.h" +#include "mozilla/Sprintf.h" + +#include "PlatformMacros.h" +#include "AutoObjectMapper.h" + +#if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) +# include <dlfcn.h> +# include "mozilla/Types.h" + // FIXME move these out of mozglue/linker/ElfLoader.h into their + // own header, so as to avoid conflicts arising from two definitions + // of Array + extern "C" { + MFBT_API size_t + __dl_get_mappable_length(void *handle); + MFBT_API void * + __dl_mmap(void *handle, void *addr, size_t length, off_t offset); + MFBT_API void + __dl_munmap(void *handle, void *addr, size_t length); + } + // The following are for get_installation_lib_dir() +# include "nsString.h" +# include "nsDirectoryServiceUtils.h" +# include "nsDirectoryServiceDefs.h" +#endif + + +// A helper function for creating failure error messages in +// AutoObjectMapper*::Map. +static void +failedToMessage(void(*aLog)(const char*), + const char* aHowFailed, std::string aFileName) +{ + char buf[300]; + SprintfLiteral(buf, "AutoObjectMapper::Map: Failed to %s \'%s\'", + aHowFailed, aFileName.c_str()); + buf[sizeof(buf)-1] = 0; + aLog(buf); +} + + +AutoObjectMapperPOSIX::AutoObjectMapperPOSIX(void(*aLog)(const char*)) + : mImage(nullptr) + , mSize(0) + , mLog(aLog) + , mIsMapped(false) +{} + +AutoObjectMapperPOSIX::~AutoObjectMapperPOSIX() { + if (!mIsMapped) { + // There's nothing to do. + MOZ_ASSERT(!mImage); + MOZ_ASSERT(mSize == 0); + return; + } + MOZ_ASSERT(mSize > 0); + // The following assertion doesn't necessarily have to be true, + // but we assume (reasonably enough) that no mmap facility would + // be crazy enough to map anything at page zero. + MOZ_ASSERT(mImage); + munmap(mImage, mSize); +} + +bool AutoObjectMapperPOSIX::Map(/*OUT*/void** start, /*OUT*/size_t* length, + std::string fileName) +{ + MOZ_ASSERT(!mIsMapped); + + int fd = open(fileName.c_str(), O_RDONLY); + if (fd == -1) { + failedToMessage(mLog, "open", fileName); + return false; + } + + struct stat st; + int err = fstat(fd, &st); + size_t sz = (err == 0) ? st.st_size : 0; + if (err != 0 || sz == 0) { + failedToMessage(mLog, "fstat", fileName); + close(fd); + return false; + } + + void* image = mmap(nullptr, sz, PROT_READ, MAP_SHARED, fd, 0); + if (image == MAP_FAILED) { + failedToMessage(mLog, "mmap", fileName); + close(fd); + return false; + } + + close(fd); + mIsMapped = true; + mImage = *start = image; + mSize = *length = sz; + return true; +} + + +#if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) +// A helper function for AutoObjectMapperFaultyLib::Map. Finds out +// where the installation's lib directory is, since we'll have to look +// in there to get hold of libmozglue.so. Returned C string is heap +// allocated and the caller must deallocate it. +static char* +get_installation_lib_dir() +{ + nsCOMPtr<nsIProperties> + directoryService(do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID)); + if (!directoryService) { + return nullptr; + } + nsCOMPtr<nsIFile> greDir; + nsresult rv = directoryService->Get(NS_GRE_DIR, NS_GET_IID(nsIFile), + getter_AddRefs(greDir)); + if (NS_FAILED(rv)) return nullptr; + nsCString path; + rv = greDir->GetNativePath(path); + if (NS_FAILED(rv)) { + return nullptr; + } + return strdup(path.get()); +} + +AutoObjectMapperFaultyLib::AutoObjectMapperFaultyLib(void(*aLog)(const char*)) + : AutoObjectMapperPOSIX(aLog) + , mHdl(nullptr) +{} + +AutoObjectMapperFaultyLib::~AutoObjectMapperFaultyLib() { + if (mHdl) { + // We've got an object mapped by faulty.lib. Unmap it via faulty.lib. + MOZ_ASSERT(mSize > 0); + // Assert on the basis that no valid mapping would start at page zero. + MOZ_ASSERT(mImage); + __dl_munmap(mHdl, mImage, mSize); + dlclose(mHdl); + // Stop assertions in ~AutoObjectMapperPOSIX from failing. + mImage = nullptr; + mSize = 0; + } + // At this point the parent class destructor, ~AutoObjectMapperPOSIX, + // gets called. If that has something mapped in the normal way, it + // will unmap it in the normal way. Unfortunately there's no + // obvious way to enforce the requirement that the object is mapped + // either by faulty.lib or by the parent class, but not by both. +} + +bool AutoObjectMapperFaultyLib::Map(/*OUT*/void** start, /*OUT*/size_t* length, + std::string fileName) +{ + MOZ_ASSERT(!mHdl); + + if (fileName == "libmozglue.so") { + + // Do (2) in the comment above. + char* libdir = get_installation_lib_dir(); + if (libdir) { + fileName = std::string(libdir) + "/lib/" + fileName; + free(libdir); + } + // Hand the problem off to the standard mapper. + return AutoObjectMapperPOSIX::Map(start, length, fileName); + + } else { + + // Do cases (1) and (3) in the comment above. We have to + // grapple with faulty.lib directly. + void* hdl = dlopen(fileName.c_str(), RTLD_GLOBAL | RTLD_LAZY); + if (!hdl) { + failedToMessage(mLog, "get handle for ELF file", fileName); + return false; + } + + size_t sz = __dl_get_mappable_length(hdl); + if (sz == 0) { + dlclose(hdl); + failedToMessage(mLog, "get size for ELF file", fileName); + return false; + } + + void* image = __dl_mmap(hdl, nullptr, sz, 0); + if (image == MAP_FAILED) { + dlclose(hdl); + failedToMessage(mLog, "mmap ELF file", fileName); + return false; + } + + mHdl = hdl; + mImage = *start = image; + mSize = *length = sz; + return true; + } +} + +#endif // defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) |