完成目标主要分成两个步骤:1)获取当前进程的所有线程;2)获取每个线程的上下文,根据堆栈回溯。
完成步骤1,需要用到以下几个接口:
- CreateToolhelp32Snapshot(), 获取当前进程的线程列表快照;
- Thread32First(),获取首个线程;
- Thread32Next(),获取下一个线程,直到遍历完成;
完成步骤2,需要用到几个接口:
- OpenThread(),获取线程句柄;
- SuspendThread(),挂起线程,保证获取上下文安全;
- ResumeThread(),恢复线程;
- GetThreadContext(),获取线程上下文,主要是寄存器RIP、RBP、RSP的值;
- SymInitialize(),初始化本进程的符号表;
- StackWalk(),回溯线程调用栈;
- SymGetSymFromAddr(), 根据地址获取符号;
- SymGetLineFromAddr(),根据地址获取源文件和行号;
- SymCleanup(),清除符号表资源;
以下是一个获取本进程所有线程调用栈的示例。
#include <Windows.h>
#include <processthreadsapi.h>
#include <Tlhelp32.h>
#include <DbgHelp.h>
#include <iostream>
#include <sstream>
#include <map>
#include <tuple>
#include <thread>
#include<assert.h>
struct TestThreadContext {
static void workert() {
for (int j = 0; j < 100000; ++j) {
if (j % 100 == 0)
cout << "thread " << GetCurrentThreadId() << " run" << endl;
Sleep(100);
}
}
// 获取其它线程堆栈
// stacks {线程id, 调用栈,错误说明}
static void get_threads_stack(std::list < std::tuple<unsigned, std::string, std::string >> & stacks) {
auto pid = GetCurrentProcessId();
auto tid = GetCurrentThreadId();
HANDLE proc = GetCurrentProcess();
SymInitialize(proc, NULL, TRUE);
HANDLE snap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, pid);
if (snap == INVALID_HANDLE_VALUE) {
return;
}
THREADENTRY32 e = { sizeof(e) };
BOOL ok = Thread32First(snap, &e);
for (; ok; ok = Thread32Next(snap, &e)) {
if (e.th32OwnerProcessID != pid || e.th32ThreadID == tid)
continue;
DWORD thread_id = e.th32ThreadID;
//cout << "open thread " << e.th32ThreadID << endl;
HANDLE th = OpenThread(THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT, FALSE, thread_id);
if (th == INVALID_HANDLE_VALUE) {
//cout << "open thread " << tid << " failed" << endl;
stacks.emplace_back(thread_id, "", "error: open failed");
continue;
}
DWORD ret = SuspendThread(th);
if (ret == (DWORD)-1) {
CloseHandle(th);
stacks.emplace_back(thread_id, "", "error: SuspendThread failed");
continue;
}
CONTEXT ctx;
ZeroMemory(&ctx, sizeof(ctx));
ctx.ContextFlags = CONTEXT_ALL;
ret = GetThreadContext(th, &ctx);
if (!ret) {
ResumeThread(th);
CloseHandle(th);
stacks.emplace_back(thread_id, "", "error: GetThreadContext failed");
continue;
}
//
STACKFRAME sf = { 0 };
sf.AddrPC.Offset = ctx.Rip;
sf.AddrPC.Mode = AddrModeFlat;
sf.AddrFrame.Offset = ctx.Rbp;
sf.AddrFrame.Mode = AddrModeFlat;
sf.AddrStack.Offset = ctx.Rsp;
sf.AddrStack.Mode = AddrModeFlat;
//
typedef struct tag_SYMBOL_INFO
{
IMAGEHLP_SYMBOL symInfo;
TCHAR szBuffer[MAX_PATH];
} SYMBOL_INFO, * LPSYMBOL_INFO;
// 32位系统下变量类型是DWORD ,64位系统下则是DWORD64
decltype(sf.AddrPC.Offset) dwDisplament = 0;
DWORD dwDis32 = 0;
SYMBOL_INFO stack_info = { 0 };
PIMAGEHLP_SYMBOL pSym = (PIMAGEHLP_SYMBOL)&stack_info;
pSym->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL);
pSym->MaxNameLength = sizeof(SYMBOL_INFO) - offsetof(SYMBOL_INFO, symInfo.Name);
IMAGEHLP_LINE ImageLine = { 0 };
ImageLine.SizeOfStruct = sizeof(IMAGEHLP_LINE);
std::string stack = "";
while (StackWalk(IMAGE_FILE_MACHINE_AMD64, proc, th, &sf, &ctx,
NULL, SymFunctionTableAccess, SymGetModuleBase, NULL))
{
char buf[512];
if (SymGetSymFromAddr(proc, sf.AddrPC.Offset, &dwDisplament, pSym)) {
if (SymGetLineFromAddr(proc, sf.AddrPC.Offset, &dwDis32, &ImageLine)) {
char* fullpath = ImageLine.FileName;
// find file name in full path
char* f = fullpath + strlen(fullpath);
while (*f != '\\' && f > fullpath) --f;
if (f > fullpath)
++f;
snprintf(buf, sizeof(buf), "%#llx+%s [%s: %d]\n",
pSym->Address, pSym->Name, f, ImageLine.LineNumber);
}
else {
snprintf(buf, sizeof(buf), "%#llx+%s\n", pSym->Address, pSym->Name);
}
}
else {
snprintf(buf, sizeof(buf), "%#llx\n", sf.AddrPC.Offset);
}
stack.append(buf);
}
stacks.emplace_back(thread_id, stack, "");
ResumeThread(th);
CloseHandle(th);
}
CloseHandle(snap);
SymCleanup(proc);
}
// 测试获取其它线程堆栈并打印
static void master() {
const int num = 4;
std::thread ws[num];
for (int j = 0; j < num; ++j)
ws[j] = std::thread(workert);
Sleep(5000);
std::list < std::tuple<unsigned, std::string, std::string >> stacks;
get_threads_stack(stacks);
for (auto& t : stacks) {
unsigned tid;
std::string stack, error;
std::tie(tid, stack, error) = t;
if (error.empty()) {
cout << "thread " << tid << "\n" << stack << std::endl;
}
else {
cout << "thread " << tid << " " << error << std::endl;
}
}
for (int j = 0; j < num; ++j)
ws[j].join();
}
};
int main(int argc, char*argv[])
{
TestThreadContext::master();
return 0;
}
以上代码在win10上用vs2019编译,c++17标准。测试输出如下所示。
thread thread 1705621204 run runthread
21480 run
thread 3868 run
thread 21328
0x7ffa6c6130c0+NtWaitForWorkViaWorkerFactory
0x7ffa6c5bff40+RtlReleaseSRWLockExclusive
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart
thread 20196
0x7ffa6c6130c0+NtWaitForWorkViaWorkerFactory
0x7ffa6c5bff40+RtlReleaseSRWLockExclusive
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart
thread 17056
0x7ffa6c60fdd0+ZwDelayExecution
0x7ffa68ed9c00+SleepEx
0x7ff771b12180+TestThreadContext::workert [cross-process.cpp: 340]
0x7ff771b16aa0+std::thread::_Invoke<std::tuple<void (__cdecl*)(void)>,0> [thread: 44]
0x7ff771b22f1c+thread_start<unsigned int (__cdecl*)(void *),1> [thread.cpp: 97]
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart
thread 21204
0x7ffa6c60fdd0+ZwDelayExecution
0x7ffa68ed9c00+SleepEx
0x7ff771b12180+TestThreadContext::workert [cross-process.cpp: 340]
0x7ff771b16aa0+std::thread::_Invoke<std::tuple<void (__cdecl*)(void)>,0> [thread: 44]
0x7ff771b22f1c+thread_start<unsigned int (__cdecl*)(void *),1> [thread.cpp: 97]
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart
thread 3868
0x7ffa6c60fdd0+ZwDelayExecution
0x7ffa68ed9c00+SleepEx
0x7ff771b12180+TestThreadContext::workert [cross-process.cpp: 340]
0x7ff771b16aa0+std::thread::_Invoke<std::tuple<void (__cdecl*)(void)>,0> [thread: 44]
0x7ff771b22f1c+thread_start<unsigned int (__cdecl*)(void *),1> [thread.cpp: 97]
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart
thread 21480
0x7ffa6c60fdd0+ZwDelayExecution
0x7ffa68ed9c00+SleepEx
0x7ff771b12180+TestThreadContext::workert [cross-process.cpp: 340]
0x7ff771b16aa0+std::thread::_Invoke<std::tuple<void (__cdecl*)(void)>,0> [thread: 44]
0x7ff771b22f1c+thread_start<unsigned int (__cdecl*)(void *),1> [thread.cpp: 97]
0x7ffa6a0f7960+BaseThreadInitThunk
0x7ffa6c5da250+RtlUserThreadStart