Merge "Fix thread unwind in CallStack." (16909c5f) · Commits · e / os / android_system_core

libutils/Android.bp

+12 −5

Original line number	Diff line number	Diff line
		@@ -299,6 +299,7 @@ cc_test {

		srcs: [
		"BitSet_test.cpp",
		"CallStack_test.cpp",
		"Errors_test.cpp",
		"FileMap_test.cpp",
		"LruCache_test.cpp",
		@@ -319,11 +320,14 @@ cc_test {
		"SystemClock_test.cpp",
		],
		shared_libs: [
		"libz",
		"liblog",
		"libbase",
		"libcutils",
		"liblog",
		"liblzma",
		"libunwindstack",
		"libutils",
		"libbase",
		"libutilscallstack",
		"libz",
		],
		},
		linux: {
		@@ -334,9 +338,12 @@ cc_test {
		},
		host: {
		static_libs: [
		"libutils",
		"liblog",
		"libbase",
		"liblog",
		"liblzma",
		"libunwindstack_no_dex",
		"libutils",
		"libutilscallstack",
		],
		},
		},

libutils/CallStack.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -49,7 +49,7 @@ void CallStack::update(int32_t ignoreDepth, pid_t tid) {
		unwindstack::AndroidUnwinderData data;
		std::optional<pid_t> tid_val;
		if (tid != -1) {
		*tid_val = tid;
		tid_val = tid;
		}
		if (!unwinder.Unwind(tid_val, data)) {
		ALOGW("%s: Failed to unwind callstack: %s", __FUNCTION__, data.GetErrorString().c_str());

libutils/CallStack_test.cpp

0 → 100644

+62 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2022 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include <unistd.h>

		#include <thread>

		#include <android-base/threads.h>
		#include <gtest/gtest.h>
		#include <utils/CallStack.h>

		[[clang::noinline]] extern "C" void CurrentCaller(android::String8& backtrace) {
		android::CallStack cs;
		cs.update();
		backtrace = cs.toString();
		}

		TEST(CallStackTest, current_backtrace) {
		android::String8 backtrace;
		CurrentCaller(backtrace);

		ASSERT_NE(-1, backtrace.find("(CurrentCaller")) << "Full backtrace:\n" << backtrace;
		}

		[[clang::noinline]] extern "C" void ThreadBusyWait(std::atomic<pid_t>* tid, volatile bool* done) {
		*tid = android::base::GetThreadId();
		while (!*done) {
		}
		}

		TEST(CallStackTest, thread_backtrace) {
		// Use a volatile to avoid any problems unwinding since sometimes
		// accessing a std::atomic does not include unwind data at every
		// instruction and leads to failed unwinds.
		volatile bool done = false;
		std::atomic<pid_t> tid = -1;
		std::thread thread([&tid, &done]() { ThreadBusyWait(&tid, &done); });

		while (tid == -1) {
		}

		android::CallStack cs;
		cs.update(0, tid);

		done = true;
		thread.join();

		ASSERT_NE(-1, cs.toString().find("(ThreadBusyWait")) << "Full backtrace:\n" << cs.toString();
		}