Merge "Test unwinding through a signal handler." (37cc8984) · Commits · e / os / android_system_core

libbacktrace/Android.bp

+1 −1

Original line number	Diff line number	Diff line
		@@ -114,7 +114,7 @@ cc_library_shared {
		none: true,
		},
		cflags: ["-O0"],
		srcs: ["backtrace_testlib.c"],
		srcs: ["backtrace_testlib.cpp"],

		target: {
		linux: {

libbacktrace/backtrace_test.cpp

+146 −7

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@
		#include <algorithm>
		#include <list>
		#include <memory>
		#include <ostream>
		#include <string>
		#include <vector>

		@@ -52,6 +53,7 @@

		// For the THREAD_SIGNAL definition.
		#include "BacktraceCurrent.h"
		#include "backtrace_testlib.h"
		#include "thread_utils.h"

		// Number of microseconds per milliseconds.
		@@ -80,13 +82,6 @@ struct dump_thread_t {
		int32_t done;
		};

		extern "C" {
		// Prototypes for functions in the test library.
		int test_level_one(int, int, int, int, void ()(void), void*);

		int test_recursive_call(int, void ()(void), void*);
		}

		static uint64_t NanoTime() {
		struct timespec t = { 0, 0 };
		clock_gettime(CLOCK_MONOTONIC, &t);
		@@ -1602,6 +1597,150 @@ TEST(libbacktrace, unwind_disallow_device_map_remote) {
		munmap(device_map, DEVICE_MAP_SIZE);
		}

		class ScopedSignalHandler {
		public:
		ScopedSignalHandler(int signal_number, void (*handler)(int)) : signal_number_(signal_number) {
		memset(&action_, 0, sizeof(action_));
		action_.sa_handler = handler;
		sigaction(signal_number_, &action_, &old_action_);
		}

		ScopedSignalHandler(int signal_number, void (action)(int, siginfo_t, void*))
		: signal_number_(signal_number) {
		memset(&action_, 0, sizeof(action_));
		action_.sa_flags = SA_SIGINFO;
		action_.sa_sigaction = action;
		sigaction(signal_number_, &action_, &old_action_);
		}

		~ScopedSignalHandler() { sigaction(signal_number_, &old_action_, nullptr); }

		private:
		struct sigaction action_;
		struct sigaction old_action_;
		const int signal_number_;
		};

		static void SetValueAndLoop(void* data) {
		volatile int* value = reinterpret_cast<volatile int*>(data);

		*value = 1;
		for (volatile int i = 0;; i++)
		;
		}

		static void UnwindThroughSignal(bool use_action) {
		volatile int value = 0;
		pid_t pid;
		if ((pid = fork()) == 0) {
		if (use_action) {
		ScopedSignalHandler ssh(SIGUSR1, test_signal_action);

		test_level_one(1, 2, 3, 4, SetValueAndLoop, const_cast<int*>(&value));
		} else {
		ScopedSignalHandler ssh(SIGUSR1, test_signal_handler);

		test_level_one(1, 2, 3, 4, SetValueAndLoop, const_cast<int*>(&value));
		}
		}
		ASSERT_NE(-1, pid);

		int read_value = 0;
		uint64_t start = NanoTime();
		while (read_value == 0) {
		usleep(1000);

		// Loop until the remote function gets into the final function.
		ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);

		WaitForStop(pid);

		std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, pid));

		size_t bytes_read = backtrace->Read(reinterpret_cast<uintptr_t>(const_cast<int*>(&value)),
		reinterpret_cast<uint8_t*>(&read_value), sizeof(read_value));
		ASSERT_EQ(sizeof(read_value), bytes_read);

		ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0);

		ASSERT_TRUE(NanoTime() - start < 5 * NS_PER_SEC)
		<< "Remote process did not execute far enough in 5 seconds.";
		}

		// Now need to send a signal to the remote process.
		kill(pid, SIGUSR1);

		// Wait for the process to get to the signal handler loop.
		Backtrace::const_iterator frame_iter;
		start = NanoTime();
		std::unique_ptr<Backtrace> backtrace;
		while (true) {
		usleep(1000);

		ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);

		WaitForStop(pid);

		backtrace.reset(Backtrace::Create(pid, pid));
		ASSERT_TRUE(backtrace->Unwind(0));
		bool found = false;
		for (frame_iter = backtrace->begin(); frame_iter != backtrace->end(); ++frame_iter) {
		if (frame_iter->func_name == "test_loop_forever") {
		++frame_iter;
		found = true;
		break;
		}
		}
		if (found) {
		break;
		}

		ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0);

		ASSERT_TRUE(NanoTime() - start < 5 * NS_PER_SEC)
		<< "Remote process did not get in signal handler in 5 seconds." << std::endl
		<< DumpFrames(backtrace.get());
		}

		std::vector<std::string> names;
		// Loop through the frames, and save the function names.
		size_t frame = 0;
		for (; frame_iter != backtrace->end(); ++frame_iter) {
		if (frame_iter->func_name == "test_level_four") {
		frame = names.size() + 1;
		}
		names.push_back(frame_iter->func_name);
		}
		ASSERT_NE(0U, frame) << "Unable to find test_level_four in backtrace" << std::endl
		<< DumpFrames(backtrace.get());

		// The expected order of the frames:
		// test_loop_forever
		// test_signal_handler\|test_signal_action
		// <OPTIONAL_FRAME> May or may not exist.
		// SetValueAndLoop (but the function name might be empty)
		// test_level_four
		// test_level_three
		// test_level_two
		// test_level_one
		ASSERT_LE(frame + 2, names.size()) << DumpFrames(backtrace.get());
		ASSERT_LE(2U, frame) << DumpFrames(backtrace.get());
		if (use_action) {
		ASSERT_EQ("test_signal_action", names[0]) << DumpFrames(backtrace.get());
		} else {
		ASSERT_EQ("test_signal_handler", names[0]) << DumpFrames(backtrace.get());
		}
		ASSERT_EQ("test_level_three", names[frame]) << DumpFrames(backtrace.get());
		ASSERT_EQ("test_level_two", names[frame + 1]) << DumpFrames(backtrace.get());
		ASSERT_EQ("test_level_one", names[frame + 2]) << DumpFrames(backtrace.get());

		FinishRemoteProcess(pid);
		}

		TEST(libbacktrace, unwind_remote_through_signal_using_handler) { UnwindThroughSignal(false); }

		TEST(libbacktrace, unwind_remote_through_signal_using_action) { UnwindThroughSignal(true); }

		#if defined(ENABLE_PSS_TESTS)
		#include "GetPss.h"

libbacktrace/backtrace_testlib.c→libbacktrace/backtrace_testlib.cpp

+23 −13

Original line number	Diff line number	Diff line
		@@ -15,31 +15,41 @@
		*/

		#include <libunwind.h>
		#include <signal.h>
		#include <stdio.h>

		int test_level_four(int one, int two, int three, int four,
		void (callback_func)(void), void* data) {
		#include "backtrace_testlib.h"

		void test_loop_forever() {
		while (1)
		;
		}

		void test_signal_handler(int) { test_loop_forever(); }

		void test_signal_action(int, siginfo_t, void) { test_loop_forever(); }

		int test_level_four(int one, int two, int three, int four, void (callback_func)(void),
		void* data) {
		if (callback_func != NULL) {
		callback_func(data);
		} else {
		while (1) {
		}
		while (1)
		;
		}
		return one + two + three + four;
		}

		int test_level_three(int one, int two, int three, int four,
		void (callback_func)(void), void* data) {
		int test_level_three(int one, int two, int three, int four, void (callback_func)(void),
		void* data) {
		return test_level_four(one + 3, two + 6, three + 9, four + 12, callback_func, data) + 3;
		}

		int test_level_two(int one, int two, int three, int four,
		void (callback_func)(void), void* data) {
		int test_level_two(int one, int two, int three, int four, void (callback_func)(void), void* data) {
		return test_level_three(one + 2, two + 4, three + 6, four + 8, callback_func, data) + 2;
		}

		int test_level_one(int one, int two, int three, int four,
		void (callback_func)(void), void* data) {
		int test_level_one(int one, int two, int three, int four, void (callback_func)(void), void* data) {
		return test_level_two(one + 1, two + 2, three + 3, four + 4, callback_func, data) + 1;
		}

libbacktrace/backtrace_testlib.h

0 → 100644

+38 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2017 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.
		*/

		#ifndef _LIBBACKTRACE_BACKTRACE_TESTLIB_H
		#define _LIBBACKTRACE_BACKTRACE_TESTLIB_H

		#include <sys/cdefs.h>

		#include <libunwind.h>

		__BEGIN_DECLS

		void test_loop_forever();
		void test_signal_handler(int);
		void test_signal_action(int, siginfo_t, void);
		int test_level_four(int, int, int, int, void ()(void), void*);
		int test_level_three(int, int, int, int, void ()(void), void*);
		int test_level_two(int, int, int, int, void ()(void), void*);
		int test_level_one(int, int, int, int, void ()(void), void*);
		int test_recursive_call(int, void ()(void), void*);
		void test_get_context_and_wait(unw_context_t, volatile int);

		__END_DECLS

		#endif // _LIBBACKTRACE_BACKTRACE_TESTLIB_H