libbacktrace_offline: support unwinding of shared libraries in apk file.
Bug: 26962895
Change-Id: I009080f26e7323247c3ab24eea614eec4432ca6a
diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index 397dfda..a8a7c4a 100644
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -94,18 +94,34 @@
libbacktrace_offline_src_files := \
BacktraceOffline.cpp \
+# Use shared llvm library on device to save space.
libbacktrace_offline_shared_libraries := \
libbacktrace \
+ libbase \
liblog \
libunwind \
-
-# Use shared llvm library on device to save space.
-libbacktrace_offline_shared_libraries_target := \
+ libutils \
libLLVM \
+libbacktrace_offline_static_libraries := \
+ libziparchive \
+ libz \
+
+module := libbacktrace_offline
+build_type := target
+build_target := SHARED_LIBRARY
+include $(LOCAL_PATH)/Android.build.mk
+
+libbacktrace_offline_shared_libraries := \
+ libbacktrace \
+ libbase \
+ liblog \
+ libunwind \
+ libziparchive-host \
+
# Use static llvm libraries on host to remove dependency on 32-bit llvm shared library
# which is not included in the prebuilt.
-libbacktrace_offline_static_libraries_host := \
+libbacktrace_offline_static_libraries := \
libLLVMObject \
libLLVMBitReader \
libLLVMMC \
@@ -114,9 +130,6 @@
libLLVMSupport \
module := libbacktrace_offline
-build_type := target
-build_target := SHARED_LIBRARY
-include $(LOCAL_PATH)/Android.build.mk
build_type := host
libbacktrace_multilib := both
include $(LOCAL_PATH)/Android.build.mk
@@ -129,6 +142,8 @@
liblog \
libunwind \
liblzma \
+ libziparchive \
+ libz \
libLLVMObject \
libLLVMBitReader \
libLLVMMC \
diff --git a/libbacktrace/BacktraceOffline.cpp b/libbacktrace/BacktraceOffline.cpp
index dc3ed67..9a4f622 100644
--- a/libbacktrace/BacktraceOffline.cpp
+++ b/libbacktrace/BacktraceOffline.cpp
@@ -29,11 +29,14 @@
#include <ucontext.h>
#include <unistd.h>
+#include <memory>
#include <string>
#include <vector>
+#include <android-base/file.h>
#include <backtrace/Backtrace.h>
#include <backtrace/BacktraceMap.h>
+#include <ziparchive/zip_archive.h>
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-parameter"
@@ -641,15 +644,103 @@
return memcmp(buf, elf_magic, 4) == 0;
}
+static bool IsValidApkPath(const std::string& apk_path) {
+ static const char zip_preamble[] = {0x50, 0x4b, 0x03, 0x04};
+ struct stat st;
+ if (stat(apk_path.c_str(), &st) != 0 || !S_ISREG(st.st_mode)) {
+ return false;
+ }
+ FILE* fp = fopen(apk_path.c_str(), "reb");
+ if (fp == nullptr) {
+ return false;
+ }
+ char buf[4];
+ if (fread(buf, 4, 1, fp) != 1) {
+ fclose(fp);
+ return false;
+ }
+ fclose(fp);
+ return memcmp(buf, zip_preamble, 4) == 0;
+}
+
+class ScopedZiparchiveHandle {
+ public:
+ ScopedZiparchiveHandle(ZipArchiveHandle handle) : handle_(handle) {
+ }
+
+ ~ScopedZiparchiveHandle() {
+ CloseArchive(handle_);
+ }
+
+ private:
+ ZipArchiveHandle handle_;
+};
+
+llvm::object::OwningBinary<llvm::object::Binary> OpenEmbeddedElfFile(const std::string& filename) {
+ llvm::object::OwningBinary<llvm::object::Binary> nothing;
+ size_t pos = filename.find("!/");
+ if (pos == std::string::npos) {
+ return nothing;
+ }
+ std::string apk_file = filename.substr(0, pos);
+ std::string elf_file = filename.substr(pos + 2);
+ if (!IsValidApkPath(apk_file)) {
+ BACK_LOGW("%s is not a valid apk file", apk_file.c_str());
+ return nothing;
+ }
+ ZipArchiveHandle handle;
+ int32_t ret_code = OpenArchive(apk_file.c_str(), &handle);
+ if (ret_code != 0) {
+ CloseArchive(handle);
+ BACK_LOGW("failed to open archive %s: %s", apk_file.c_str(), ErrorCodeString(ret_code));
+ return nothing;
+ }
+ ScopedZiparchiveHandle scoped_handle(handle);
+ ZipEntry zentry;
+ ret_code = FindEntry(handle, ZipString(elf_file.c_str()), &zentry);
+ if (ret_code != 0) {
+ BACK_LOGW("failed to find %s in %s: %s", elf_file.c_str(), apk_file.c_str(),
+ ErrorCodeString(ret_code));
+ return nothing;
+ }
+ if (zentry.method != kCompressStored || zentry.compressed_length != zentry.uncompressed_length) {
+ BACK_LOGW("%s is compressed in %s, which doesn't support running directly", elf_file.c_str(),
+ apk_file.c_str());
+ return nothing;
+ }
+ auto buffer_or_err = llvm::MemoryBuffer::getOpenFileSlice(GetFileDescriptor(handle), apk_file,
+ zentry.uncompressed_length,
+ zentry.offset);
+ if (!buffer_or_err) {
+ BACK_LOGW("failed to read %s in %s: %s", elf_file.c_str(), apk_file.c_str(),
+ buffer_or_err.getError().message().c_str());
+ return nothing;
+ }
+ auto binary_or_err = llvm::object::createBinary(buffer_or_err.get()->getMemBufferRef());
+ if (!binary_or_err) {
+ BACK_LOGW("failed to create binary for %s in %s: %s", elf_file.c_str(), apk_file.c_str(),
+ binary_or_err.getError().message().c_str());
+ return nothing;
+ }
+ return llvm::object::OwningBinary<llvm::object::Binary>(std::move(binary_or_err.get()),
+ std::move(buffer_or_err.get()));
+}
+
static DebugFrameInfo* ReadDebugFrameFromFile(const std::string& filename) {
- if (!IsValidElfPath(filename)) {
- return nullptr;
+ llvm::object::OwningBinary<llvm::object::Binary> owning_binary;
+ if (filename.find("!/") != std::string::npos) {
+ owning_binary = OpenEmbeddedElfFile(filename);
+ } else {
+ if (!IsValidElfPath(filename)) {
+ return nullptr;
+ }
+ auto binary_or_err = llvm::object::createBinary(llvm::StringRef(filename));
+ if (!binary_or_err) {
+ return nullptr;
+ }
+ owning_binary = std::move(binary_or_err.get());
}
- auto owning_binary = llvm::object::createBinary(llvm::StringRef(filename));
- if (owning_binary.getError()) {
- return nullptr;
- }
- llvm::object::Binary* binary = owning_binary.get().getBinary();
+ llvm::object::Binary* binary = owning_binary.getBinary();
auto obj = llvm::dyn_cast<llvm::object::ObjectFile>(binary);
if (obj == nullptr) {
return nullptr;
