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/*
* Copyright (C) 2013 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.
*/
/*
* Contributed by: Intel Corporation
*/
#include <gtest/gtest.h>
#include <dlfcn.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <unwind.h>
#include "SignalUtils.h"
#define noinline __attribute__((__noinline__))
#define __unused __attribute__((__unused__))
_Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
int* count_ptr = reinterpret_cast<int*>(arg);
#if SHOW_FRAME_LOCATIONS
void* ip = reinterpret_cast<void*>(_Unwind_GetIP(ctx));
const char* symbol = "<unknown>";
int offset = 0;
Dl_info info;
memset(&info, 0, sizeof(info));
if (dladdr(ip, &info) != 0) {
symbol = info.dli_sname;
if (info.dli_saddr != nullptr) {
offset = static_cast<int>(reinterpret_cast<char*>(ip) - reinterpret_cast<char*>(info.dli_saddr));
}
}
fprintf(stderr, " #%02d %p %s%+d (%s)\n", *count_ptr, ip, symbol, offset, info.dli_fname ? info.dli_fname : "??");
fflush(stderr);
#endif
++*count_ptr;
return _URC_NO_REASON;
}
static int noinline unwind_one_frame_deeper() {
int count = 0;
_Unwind_Backtrace(FrameCounter, &count);
return count;
}
static void UnwindTest() {
int count = 0;
_Unwind_Backtrace(FrameCounter, &count);
int deeper_count = unwind_one_frame_deeper();
ASSERT_EQ(count + 1, deeper_count);
}
TEST(stack_unwinding, easy) {
UnwindTest();
}
TEST(stack_unwinding, thread) {
pthread_t thread;
ASSERT_EQ(0, pthread_create(&thread, nullptr, [](void*) -> void* {
UnwindTest();
return nullptr;
}, nullptr));
void *retval;
ASSERT_EQ(0, pthread_join(thread, &retval));
EXPECT_EQ(nullptr, retval);
}
struct UnwindData {
volatile bool signal_handler_complete = false;
int expected_frame_count = 0;
int handler_frame_count = 0;
int handler_one_deeper_frame_count = 0;
};
static UnwindData g_unwind_data;
static void noinline UnwindSignalHandler(int) {
_Unwind_Backtrace(FrameCounter, &g_unwind_data.handler_frame_count);
g_unwind_data.handler_one_deeper_frame_count = unwind_one_frame_deeper();
g_unwind_data.signal_handler_complete = true;
}
static void verify_unwind_data(const UnwindData& unwind_data) {
// In order to avoid a false positive, the caller must have at least 2 frames
// outside of the signal handler. This avoids a case where the only frame
// right after the signal handler winds up being garbage.
EXPECT_GT(unwind_data.handler_frame_count, unwind_data.expected_frame_count + 1);
EXPECT_EQ(unwind_data.handler_frame_count + 1, unwind_data.handler_one_deeper_frame_count);
}
static void noinline SignalUnwindTest() {
g_unwind_data = {};
_Unwind_Backtrace(FrameCounter, &g_unwind_data.expected_frame_count);
ASSERT_LE(2, g_unwind_data.expected_frame_count)
<< "The current call must contain at least 2 frames for the test to be valid.";
ASSERT_EQ(0, kill(getpid(), SIGUSR1));
while (!g_unwind_data.signal_handler_complete) {}
verify_unwind_data(g_unwind_data);
}
TEST(stack_unwinding, unwind_through_signal_frame) {
ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler);
SignalUnwindTest();
}
// On LP32, the SA_SIGINFO flag gets you __restore_rt instead of __restore.
TEST(stack_unwinding, unwind_through_signal_frame_SA_SIGINFO) {
ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler, SA_SIGINFO);
SignalUnwindTest();
}
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