gecko/xpcom/base/nsStackWalk.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
2012-05-21 04:12:37 -07:00
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* API for getting a stack trace of the C/C++ stack on the current thread */
#include "mozilla/Assertions.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "mozilla/StackWalk.h"
#include "nsStackWalkPrivate.h"
#include "nsStackWalk.h"
using namespace mozilla;
// The presence of this address is the stack must stop the stack walk. If
// there is no such address, the structure will be {nullptr, true}.
struct CriticalAddress
{
void* mAddr;
bool mInit;
};
static CriticalAddress gCriticalAddress;
// for _Unwind_Backtrace from libcxxrt or libunwind
// cxxabi.h from libcxxrt implicitly includes unwind.h first
#if defined(HAVE__UNWIND_BACKTRACE) && !defined(_GNU_SOURCE)
#define _GNU_SOURCE
#endif
#if defined(HAVE_DLOPEN) || defined(XP_MACOSX)
#include <dlfcn.h>
#endif
#define NSSTACKWALK_SUPPORTS_MACOSX \
(defined(XP_MACOSX) && \
(defined(__i386) || defined(__ppc__) || defined(HAVE__UNWIND_BACKTRACE)))
#define NSSTACKWALK_SUPPORTS_LINUX \
(defined(linux) && \
((defined(__GNUC__) && (defined(__i386) || defined(PPC))) || \
defined(HAVE__UNWIND_BACKTRACE)))
#define NSSTACKWALK_SUPPORTS_SOLARIS \
(defined(__sun) && \
(defined(__sparc) || defined(sparc) || defined(__i386) || defined(i386)))
#if NSSTACKWALK_SUPPORTS_MACOSX
#include <pthread.h>
#include <CoreServices/CoreServices.h>
typedef void
malloc_logger_t(uint32_t aType,
uintptr_t aArg1, uintptr_t aArg2, uintptr_t aArg3,
uintptr_t aResult, uint32_t aNumHotFramesToSkip);
extern malloc_logger_t* malloc_logger;
static void
stack_callback(void* aPc, void* aSp, void* aClosure)
{
const char* name = static_cast<char*>(aClosure);
Dl_info info;
// On Leopard dladdr returns the wrong value for "new_sem_from_pool". The
// stack shows up as having two pthread_cond_wait$UNIX2003 frames. The
// correct one is the first that we find on our way up, so the
// following check for gCriticalAddress.mAddr is critical.
if (gCriticalAddress.mAddr || dladdr(aPc, &info) == 0 ||
!info.dli_sname || strcmp(info.dli_sname, name) != 0) {
return;
}
gCriticalAddress.mAddr = aPc;
}
#ifdef DEBUG
#define MAC_OS_X_VERSION_10_7_HEX 0x00001070
static int32_t OSXVersion()
{
static int32_t gOSXVersion = 0x0;
if (gOSXVersion == 0x0) {
OSErr err = ::Gestalt(gestaltSystemVersion, (SInt32*)&gOSXVersion);
MOZ_ASSERT(err == noErr);
}
return gOSXVersion;
}
static bool OnLionOrLater()
{
return (OSXVersion() >= MAC_OS_X_VERSION_10_7_HEX);
}
#endif
static void
my_malloc_logger(uint32_t aType,
uintptr_t aArg1, uintptr_t aArg2, uintptr_t aArg3,
uintptr_t aResult, uint32_t aNumHotFramesToSkip)
{
static bool once = false;
if (once) {
return;
}
once = true;
// On Leopard dladdr returns the wrong value for "new_sem_from_pool". The
// stack shows up as having two pthread_cond_wait$UNIX2003 frames.
const char* name = "new_sem_from_pool";
NS_StackWalk(stack_callback, /* skipFrames */ 0, /* maxFrames */ 0,
const_cast<char*>(name), 0, nullptr);
}
// This is called from NS_LogInit() and from the stack walking functions, but
// only the first call has any effect. We need to call this function from both
// places because it must run before any mutexes are created, and also before
// any objects whose refcounts we're logging are created. Running this
// function during NS_LogInit() ensures that we meet the first criterion, and
// running this function during the stack walking functions ensures we meet the
// second criterion.
void
StackWalkInitCriticalAddress()
{
if (gCriticalAddress.mInit) {
return;
}
gCriticalAddress.mInit = true;
// We must not do work when 'new_sem_from_pool' calls realloc, since
// it holds a non-reentrant spin-lock and we will quickly deadlock.
// new_sem_from_pool is not directly accessible using dlsym, so
// we force a situation where new_sem_from_pool is on the stack and
// use dladdr to check the addresses.
// malloc_logger can be set by external tools like 'Instruments' or 'leaks'
malloc_logger_t* old_malloc_logger = malloc_logger;
malloc_logger = my_malloc_logger;
pthread_cond_t cond;
int r = pthread_cond_init(&cond, 0);
MOZ_ASSERT(r == 0);
pthread_mutex_t mutex;
r = pthread_mutex_init(&mutex, 0);
MOZ_ASSERT(r == 0);
r = pthread_mutex_lock(&mutex);
MOZ_ASSERT(r == 0);
struct timespec abstime = { 0, 1 };
r = pthread_cond_timedwait_relative_np(&cond, &mutex, &abstime);
// restore the previous malloc logger
malloc_logger = old_malloc_logger;
// On Lion, malloc is no longer called from pthread_cond_*wait*. This prevents
// us from finding the address, but that is fine, since with no call to malloc
// there is no critical address.
MOZ_ASSERT(OnLionOrLater() || gCriticalAddress.mAddr != nullptr);
MOZ_ASSERT(r == ETIMEDOUT);
r = pthread_mutex_unlock(&mutex);
MOZ_ASSERT(r == 0);
r = pthread_mutex_destroy(&mutex);
MOZ_ASSERT(r == 0);
r = pthread_cond_destroy(&cond);
MOZ_ASSERT(r == 0);
}
static bool
IsCriticalAddress(void* aPC)
{
return gCriticalAddress.mAddr == aPC;
}
#else
static bool
IsCriticalAddress(void* aPC)
{
return false;
}
// We still initialize gCriticalAddress.mInit so that this code behaves
// the same on all platforms. Otherwise a failure to init would be visible
// only on OS X.
void
StackWalkInitCriticalAddress()
{
gCriticalAddress.mInit = true;
}
#endif
#if defined(_WIN32) && (defined(_M_IX86) || defined(_M_AMD64) || defined(_M_IA64)) // WIN32 x86 stack walking code
#include "nscore.h"
#include <windows.h>
#include <process.h>
#include <stdio.h>
#include <malloc.h>
#include "plstr.h"
#include "mozilla/ArrayUtils.h"
#include "nspr.h"
#include <imagehlp.h>
// We need a way to know if we are building for WXP (or later), as if we are, we
// need to use the newer 64-bit APIs. API_VERSION_NUMBER seems to fit the bill.
// A value of 9 indicates we want to use the new APIs.
#if API_VERSION_NUMBER < 9
#error Too old imagehlp.h
#endif
// Define these as static pointers so that we can load the DLL on the
// fly (and not introduce a link-time dependency on it). Tip o' the
// hat to Matt Pietrick for this idea. See:
//
// http://msdn.microsoft.com/library/periodic/period97/F1/D3/S245C6.htm
//
extern "C" {
extern HANDLE hStackWalkMutex;
bool EnsureSymInitialized();
bool EnsureWalkThreadReady();
struct WalkStackData
{
uint32_t skipFrames;
HANDLE thread;
bool walkCallingThread;
HANDLE process;
HANDLE eventStart;
HANDLE eventEnd;
void** pcs;
uint32_t pc_size;
uint32_t pc_count;
uint32_t pc_max;
void** sps;
uint32_t sp_size;
uint32_t sp_count;
void* platformData;
};
void PrintError(char* aPrefix, WalkStackData* aData);
unsigned int WINAPI WalkStackThread(void* aData);
void WalkStackMain64(struct WalkStackData* aData);
DWORD gStackWalkThread;
CRITICAL_SECTION gDbgHelpCS;
}
// Routine to print an error message to standard error.
void
PrintError(const char* aPrefix)
{
LPVOID lpMsgBuf;
DWORD lastErr = GetLastError();
FormatMessageA(
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
nullptr,
lastErr,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
(LPSTR) &lpMsgBuf,
0,
nullptr
);
fprintf(stderr, "### ERROR: %s: %s",
aPrefix, lpMsgBuf ? lpMsgBuf : "(null)\n");
fflush(stderr);
LocalFree(lpMsgBuf);
}
bool
EnsureWalkThreadReady()
{
static bool walkThreadReady = false;
static HANDLE stackWalkThread = nullptr;
static HANDLE readyEvent = nullptr;
if (walkThreadReady) {
return walkThreadReady;
}
if (!stackWalkThread) {
readyEvent = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
FALSE /* initially non-signaled */,
nullptr);
if (!readyEvent) {
PrintError("CreateEvent");
return false;
}
unsigned int threadID;
stackWalkThread = (HANDLE)
_beginthreadex(nullptr, 0, WalkStackThread, (void*)readyEvent,
0, &threadID);
if (!stackWalkThread) {
PrintError("CreateThread");
::CloseHandle(readyEvent);
readyEvent = nullptr;
return false;
}
gStackWalkThread = threadID;
::CloseHandle(stackWalkThread);
}
MOZ_ASSERT((stackWalkThread && readyEvent) ||
(!stackWalkThread && !readyEvent));
// The thread was created. Try to wait an arbitrary amount of time (1 second
// should be enough) for its event loop to start before posting events to it.
DWORD waitRet = ::WaitForSingleObject(readyEvent, 1000);
if (waitRet == WAIT_TIMEOUT) {
// We get a timeout if we're called during static initialization because
// the thread will only start executing after we return so it couldn't
// have signalled the event. If that is the case, give up for now and
// try again next time we're called.
return false;
}
::CloseHandle(readyEvent);
stackWalkThread = nullptr;
readyEvent = nullptr;
::InitializeCriticalSection(&gDbgHelpCS);
return walkThreadReady = true;
}
void
WalkStackMain64(struct WalkStackData* aData)
{
// Get the context information for the thread. That way we will
// know where our sp, fp, pc, etc. are and can fill in the
// STACKFRAME64 with the initial values.
CONTEXT context;
HANDLE myProcess = aData->process;
HANDLE myThread = aData->thread;
DWORD64 addr;
DWORD64 spaddr;
STACKFRAME64 frame64;
// skip our own stack walking frames
int skip = (aData->walkCallingThread ? 3 : 0) + aData->skipFrames;
BOOL ok;
// Get a context for the specified thread.
if (!aData->platformData) {
memset(&context, 0, sizeof(CONTEXT));
context.ContextFlags = CONTEXT_FULL;
if (!GetThreadContext(myThread, &context)) {
if (aData->walkCallingThread) {
PrintError("GetThreadContext");
}
return;
}
} else {
context = *static_cast<CONTEXT*>(aData->platformData);
}
// Setup initial stack frame to walk from
memset(&frame64, 0, sizeof(frame64));
#ifdef _M_IX86
frame64.AddrPC.Offset = context.Eip;
frame64.AddrStack.Offset = context.Esp;
frame64.AddrFrame.Offset = context.Ebp;
#elif defined _M_AMD64
frame64.AddrPC.Offset = context.Rip;
frame64.AddrStack.Offset = context.Rsp;
frame64.AddrFrame.Offset = context.Rbp;
#elif defined _M_IA64
frame64.AddrPC.Offset = context.StIIP;
frame64.AddrStack.Offset = context.SP;
frame64.AddrFrame.Offset = context.RsBSP;
#else
#error "Should not have compiled this code"
#endif
frame64.AddrPC.Mode = AddrModeFlat;
frame64.AddrStack.Mode = AddrModeFlat;
frame64.AddrFrame.Mode = AddrModeFlat;
frame64.AddrReturn.Mode = AddrModeFlat;
// Now walk the stack
while (1) {
// debug routines are not threadsafe, so grab the lock.
EnterCriticalSection(&gDbgHelpCS);
ok = StackWalk64(
#ifdef _M_AMD64
IMAGE_FILE_MACHINE_AMD64,
#elif defined _M_IA64
IMAGE_FILE_MACHINE_IA64,
#elif defined _M_IX86
IMAGE_FILE_MACHINE_I386,
#else
#error "Should not have compiled this code"
#endif
myProcess,
myThread,
&frame64,
&context,
nullptr,
SymFunctionTableAccess64, // function table access routine
SymGetModuleBase64, // module base routine
0
);
LeaveCriticalSection(&gDbgHelpCS);
if (ok) {
addr = frame64.AddrPC.Offset;
spaddr = frame64.AddrStack.Offset;
} else {
addr = 0;
spaddr = 0;
if (aData->walkCallingThread) {
PrintError("WalkStack64");
}
}
if (!ok || (addr == 0)) {
break;
}
if (skip-- > 0) {
continue;
}
if (aData->pc_count < aData->pc_size) {
aData->pcs[aData->pc_count] = (void*)addr;
}
++aData->pc_count;
if (aData->sp_count < aData->sp_size) {
aData->sps[aData->sp_count] = (void*)spaddr;
}
++aData->sp_count;
if (aData->pc_max != 0 && aData->pc_count == aData->pc_max) {
break;
}
if (frame64.AddrReturn.Offset == 0) {
break;
}
}
return;
}
unsigned int WINAPI
WalkStackThread(void* aData)
{
BOOL msgRet;
MSG msg;
// Call PeekMessage to force creation of a message queue so that
// other threads can safely post events to us.
::PeekMessage(&msg, nullptr, WM_USER, WM_USER, PM_NOREMOVE);
// and tell the thread that created us that we're ready.
HANDLE readyEvent = (HANDLE)aData;
::SetEvent(readyEvent);
while ((msgRet = ::GetMessage(&msg, (HWND) - 1, 0, 0)) != 0) {
if (msgRet == -1) {
PrintError("GetMessage");
} else {
DWORD ret;
struct WalkStackData* data = (WalkStackData*)msg.lParam;
if (!data) {
continue;
}
// Don't suspend the calling thread until it's waiting for
// us; otherwise the number of frames on the stack could vary.
ret = ::WaitForSingleObject(data->eventStart, INFINITE);
if (ret != WAIT_OBJECT_0) {
PrintError("WaitForSingleObject");
}
// Suspend the calling thread, dump his stack, and then resume him.
// He's currently waiting for us to finish so now should be a good time.
ret = ::SuspendThread(data->thread);
if (ret == -1) {
PrintError("ThreadSuspend");
} else {
WalkStackMain64(data);
ret = ::ResumeThread(data->thread);
if (ret == -1) {
PrintError("ThreadResume");
}
}
::SetEvent(data->eventEnd);
}
}
return 0;
}
/**
* Walk the stack, translating PC's found into strings and recording the
* chain in aBuffer. For this to work properly, the DLLs must be rebased
* so that the address in the file agrees with the address in memory.
* Otherwise StackWalk will return FALSE when it hits a frame in a DLL
* whose in memory address doesn't match its in-file address.
*/
EXPORT_XPCOM_API(nsresult)
NS_StackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
void* aPlatformData)
{
StackWalkInitCriticalAddress();
static HANDLE myProcess = nullptr;
HANDLE myThread;
DWORD walkerReturn;
struct WalkStackData data;
if (!EnsureWalkThreadReady()) {
return NS_ERROR_FAILURE;
}
HANDLE targetThread = ::GetCurrentThread();
data.walkCallingThread = true;
if (aThread) {
HANDLE threadToWalk = reinterpret_cast<HANDLE>(aThread);
// walkCallingThread indicates whether we are walking the caller's stack
data.walkCallingThread = (threadToWalk == targetThread);
targetThread = threadToWalk;
}
// We need to avoid calling fprintf and friends if we're walking the stack of
// another thread, in order to avoid deadlocks.
const bool shouldBeThreadSafe = !!aThread;
// Have to duplicate handle to get a real handle.
if (!myProcess) {
if (!::DuplicateHandle(::GetCurrentProcess(),
::GetCurrentProcess(),
::GetCurrentProcess(),
&myProcess,
PROCESS_ALL_ACCESS, FALSE, 0)) {
if (!shouldBeThreadSafe) {
PrintError("DuplicateHandle (process)");
}
return NS_ERROR_FAILURE;
}
}
if (!::DuplicateHandle(::GetCurrentProcess(),
targetThread,
::GetCurrentProcess(),
&myThread,
THREAD_ALL_ACCESS, FALSE, 0)) {
if (!shouldBeThreadSafe) {
PrintError("DuplicateHandle (thread)");
}
return NS_ERROR_FAILURE;
}
data.skipFrames = aSkipFrames;
data.thread = myThread;
data.process = myProcess;
void* local_pcs[1024];
data.pcs = local_pcs;
data.pc_count = 0;
data.pc_size = ArrayLength(local_pcs);
data.pc_max = aMaxFrames;
void* local_sps[1024];
data.sps = local_sps;
data.sp_count = 0;
data.sp_size = ArrayLength(local_sps);
data.platformData = aPlatformData;
if (aThread) {
// If we're walking the stack of another thread, we don't need to
// use a separate walker thread.
WalkStackMain64(&data);
if (data.pc_count > data.pc_size) {
data.pcs = (void**)_alloca(data.pc_count * sizeof(void*));
data.pc_size = data.pc_count;
data.pc_count = 0;
data.sps = (void**)_alloca(data.sp_count * sizeof(void*));
data.sp_size = data.sp_count;
data.sp_count = 0;
WalkStackMain64(&data);
}
} else {
data.eventStart = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
FALSE /* initially non-signaled */, nullptr);
data.eventEnd = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
FALSE /* initially non-signaled */, nullptr);
::PostThreadMessage(gStackWalkThread, WM_USER, 0, (LPARAM)&data);
walkerReturn = ::SignalObjectAndWait(data.eventStart,
data.eventEnd, INFINITE, FALSE);
if (walkerReturn != WAIT_OBJECT_0 && !shouldBeThreadSafe) {
PrintError("SignalObjectAndWait (1)");
}
if (data.pc_count > data.pc_size) {
data.pcs = (void**)_alloca(data.pc_count * sizeof(void*));
data.pc_size = data.pc_count;
data.pc_count = 0;
data.sps = (void**)_alloca(data.sp_count * sizeof(void*));
data.sp_size = data.sp_count;
data.sp_count = 0;
::PostThreadMessage(gStackWalkThread, WM_USER, 0, (LPARAM)&data);
walkerReturn = ::SignalObjectAndWait(data.eventStart,
data.eventEnd, INFINITE, FALSE);
if (walkerReturn != WAIT_OBJECT_0 && !shouldBeThreadSafe) {
PrintError("SignalObjectAndWait (2)");
}
}
::CloseHandle(data.eventStart);
::CloseHandle(data.eventEnd);
}
::CloseHandle(myThread);
for (uint32_t i = 0; i < data.pc_count; ++i) {
(*aCallback)(data.pcs[i], data.sps[i], aClosure);
}
return data.pc_count == 0 ? NS_ERROR_FAILURE : NS_OK;
}
static BOOL CALLBACK
callbackEspecial64(
PCSTR aModuleName,
DWORD64 aModuleBase,
ULONG aModuleSize,
PVOID aUserContext)
{
BOOL retval = TRUE;
DWORD64 addr = *(DWORD64*)aUserContext;
/*
* You'll want to control this if we are running on an
* architecture where the addresses go the other direction.
* Not sure this is even a realistic consideration.
*/
const BOOL addressIncreases = TRUE;
/*
* If it falls in side the known range, load the symbols.
*/
if (addressIncreases
? (addr >= aModuleBase && addr <= (aModuleBase + aModuleSize))
: (addr <= aModuleBase && addr >= (aModuleBase - aModuleSize))
) {
retval = !!SymLoadModule64(GetCurrentProcess(), nullptr,
(PSTR)aModuleName, nullptr,
aModuleBase, aModuleSize);
if (!retval) {
PrintError("SymLoadModule64");
}
}
return retval;
}
/*
* SymGetModuleInfoEspecial
*
* Attempt to determine the module information.
* Bug 112196 says this DLL may not have been loaded at the time
* SymInitialize was called, and thus the module information
* and symbol information is not available.
* This code rectifies that problem.
*/
// New members were added to IMAGEHLP_MODULE64 (that show up in the
// Platform SDK that ships with VC8, but not the Platform SDK that ships
// with VC7.1, i.e., between DbgHelp 6.0 and 6.1), but we don't need to
// use them, and it's useful to be able to function correctly with the
// older library. (Stock Windows XP SP2 seems to ship with dbghelp.dll
// version 5.1.) Since Platform SDK version need not correspond to
// compiler version, and the version number in debughlp.h was NOT bumped
// when these changes were made, ifdef based on a constant that was
// added between these versions.
#ifdef SSRVOPT_SETCONTEXT
#define NS_IMAGEHLP_MODULE64_SIZE (((offsetof(IMAGEHLP_MODULE64, LoadedPdbName) + sizeof(DWORD64) - 1) / sizeof(DWORD64)) * sizeof(DWORD64))
#else
#define NS_IMAGEHLP_MODULE64_SIZE sizeof(IMAGEHLP_MODULE64)
#endif
BOOL SymGetModuleInfoEspecial64(HANDLE aProcess, DWORD64 aAddr,
PIMAGEHLP_MODULE64 aModuleInfo,
PIMAGEHLP_LINE64 aLineInfo)
{
BOOL retval = FALSE;
/*
* Init the vars if we have em.
*/
aModuleInfo->SizeOfStruct = NS_IMAGEHLP_MODULE64_SIZE;
if (aLineInfo) {
aLineInfo->SizeOfStruct = sizeof(IMAGEHLP_LINE64);
}
/*
* Give it a go.
* It may already be loaded.
*/
retval = SymGetModuleInfo64(aProcess, aAddr, aModuleInfo);
if (retval == FALSE) {
/*
* Not loaded, here's the magic.
* Go through all the modules.
*/
// Need to cast to PENUMLOADED_MODULES_CALLBACK64 because the
// constness of the first parameter of
// PENUMLOADED_MODULES_CALLBACK64 varies over SDK versions (from
// non-const to const over time). See bug 391848 and bug
// 415426.
BOOL enumRes = EnumerateLoadedModules64(
aProcess,
(PENUMLOADED_MODULES_CALLBACK64)callbackEspecial64,
(PVOID)&aAddr);
if (enumRes != FALSE) {
/*
* One final go.
* If it fails, then well, we have other problems.
*/
retval = SymGetModuleInfo64(aProcess, aAddr, aModuleInfo);
}
}
/*
* If we got module info, we may attempt line info as well.
* We will not report failure if this does not work.
*/
if (retval != FALSE && aLineInfo) {
DWORD displacement = 0;
BOOL lineRes = FALSE;
lineRes = SymGetLineFromAddr64(aProcess, aAddr, &displacement, aLineInfo);
if (!lineRes) {
// Clear out aLineInfo to indicate that it's not valid
memset(aLineInfo, 0, sizeof(*aLineInfo));
}
}
return retval;
}
bool
EnsureSymInitialized()
{
static bool gInitialized = false;
bool retStat;
if (gInitialized) {
return gInitialized;
}
if (!EnsureWalkThreadReady()) {
return false;
}
SymSetOptions(SYMOPT_LOAD_LINES | SYMOPT_UNDNAME);
retStat = SymInitialize(GetCurrentProcess(), nullptr, TRUE);
if (!retStat) {
PrintError("SymInitialize");
}
gInitialized = retStat;
/* XXX At some point we need to arrange to call SymCleanup */
return retStat;
}
EXPORT_XPCOM_API(nsresult)
NS_DescribeCodeAddress(void* aPC, nsCodeAddressDetails* aDetails)
{
aDetails->library[0] = '\0';
aDetails->loffset = 0;
aDetails->filename[0] = '\0';
aDetails->lineno = 0;
aDetails->function[0] = '\0';
aDetails->foffset = 0;
if (!EnsureSymInitialized()) {
return NS_ERROR_FAILURE;
}
HANDLE myProcess = ::GetCurrentProcess();
BOOL ok;
// debug routines are not threadsafe, so grab the lock.
EnterCriticalSection(&gDbgHelpCS);
//
// Attempt to load module info before we attempt to resolve the symbol.
// This just makes sure we get good info if available.
//
DWORD64 addr = (DWORD64)aPC;
IMAGEHLP_MODULE64 modInfo;
IMAGEHLP_LINE64 lineInfo;
BOOL modInfoRes;
modInfoRes = SymGetModuleInfoEspecial64(myProcess, addr, &modInfo, &lineInfo);
if (modInfoRes) {
PL_strncpyz(aDetails->library, modInfo.ModuleName,
sizeof(aDetails->library));
aDetails->loffset = (char*)aPC - (char*)modInfo.BaseOfImage;
if (lineInfo.FileName) {
PL_strncpyz(aDetails->filename, lineInfo.FileName,
sizeof(aDetails->filename));
aDetails->lineno = lineInfo.LineNumber;
}
}
ULONG64 buffer[(sizeof(SYMBOL_INFO) +
MAX_SYM_NAME * sizeof(TCHAR) + sizeof(ULONG64) - 1) / sizeof(ULONG64)];
PSYMBOL_INFO pSymbol = (PSYMBOL_INFO)buffer;
pSymbol->SizeOfStruct = sizeof(SYMBOL_INFO);
pSymbol->MaxNameLen = MAX_SYM_NAME;
DWORD64 displacement;
ok = SymFromAddr(myProcess, addr, &displacement, pSymbol);
if (ok) {
PL_strncpyz(aDetails->function, pSymbol->Name,
sizeof(aDetails->function));
aDetails->foffset = static_cast<ptrdiff_t>(displacement);
}
LeaveCriticalSection(&gDbgHelpCS); // release our lock
return NS_OK;
}
EXPORT_XPCOM_API(nsresult)
NS_FormatCodeAddressDetails(void* aPC, const nsCodeAddressDetails* aDetails,
char* aBuffer, uint32_t aBufferSize)
{
if (aDetails->function[0]) {
_snprintf(aBuffer, aBufferSize, "%s+0x%08lX [%s +0x%016lX]",
aDetails->function, aDetails->foffset,
aDetails->library, aDetails->loffset);
} else if (aDetails->library[0]) {
_snprintf(aBuffer, aBufferSize, "UNKNOWN [%s +0x%016lX]",
aDetails->library, aDetails->loffset);
} else {
_snprintf(aBuffer, aBufferSize, "UNKNOWN 0x%016lX", aPC);
}
aBuffer[aBufferSize - 1] = '\0';
uint32_t len = strlen(aBuffer);
if (aDetails->filename[0]) {
_snprintf(aBuffer + len, aBufferSize - len, " (%s, line %d)\n",
aDetails->filename, aDetails->lineno);
} else {
aBuffer[len] = '\n';
if (++len != aBufferSize) {
aBuffer[len] = '\0';
}
}
aBuffer[aBufferSize - 2] = '\n';
aBuffer[aBufferSize - 1] = '\0';
return NS_OK;
}
// WIN32 x86 stack walking code
// i386 or PPC Linux stackwalking code or Solaris
#elif HAVE_DLADDR && (HAVE__UNWIND_BACKTRACE || NSSTACKWALK_SUPPORTS_LINUX || NSSTACKWALK_SUPPORTS_SOLARIS || NSSTACKWALK_SUPPORTS_MACOSX)
#include <stdlib.h>
#include <string.h>
#include "nscore.h"
#include <stdio.h>
#include "plstr.h"
// On glibc 2.1, the Dl_info api defined in <dlfcn.h> is only exposed
// if __USE_GNU is defined. I suppose its some kind of standards
// adherence thing.
//
#if (__GLIBC_MINOR__ >= 1) && !defined(__USE_GNU)
#define __USE_GNU
#endif
// This thing is exported by libstdc++
// Yes, this is a gcc only hack
#if defined(MOZ_DEMANGLE_SYMBOLS)
#include <cxxabi.h>
#endif // MOZ_DEMANGLE_SYMBOLS
void DemangleSymbol(const char* aSymbol,
char* aBuffer,
int aBufLen)
{
aBuffer[0] = '\0';
#if defined(MOZ_DEMANGLE_SYMBOLS)
/* See demangle.h in the gcc source for the voodoo */
char* demangled = abi::__cxa_demangle(aSymbol, 0, 0, 0);
if (demangled) {
PL_strncpyz(aBuffer, demangled, aBufLen);
free(demangled);
}
#endif // MOZ_DEMANGLE_SYMBOLS
}
#if NSSTACKWALK_SUPPORTS_SOLARIS
/*
* Stack walking code for Solaris courtesy of Bart Smaalder's "memtrak".
*/
#include <synch.h>
#include <ucontext.h>
#include <sys/frame.h>
#include <sys/regset.h>
#include <sys/stack.h>
static int load_address ( void * pc, void * arg );
static struct bucket * newbucket ( void * pc );
static struct frame * cs_getmyframeptr ( void );
static void cs_walk_stack ( void * (*read_func)(char * address),
struct frame * fp,
int (*operate_func)(void *, void *, void *),
void * usrarg );
static void cs_operate ( void (*operate_func)(void *, void *, void *),
void * usrarg );
#ifndef STACK_BIAS
#define STACK_BIAS 0
#endif /*STACK_BIAS*/
#define LOGSIZE 4096
/* type of demangling function */
typedef int demf_t(const char *, char *, size_t);
static demf_t *demf;
static int initialized = 0;
#if defined(sparc) || defined(__sparc)
#define FRAME_PTR_REGISTER REG_SP
#endif
#if defined(i386) || defined(__i386)
#define FRAME_PTR_REGISTER EBP
#endif
struct bucket {
void * pc;
int index;
struct bucket * next;
};
struct my_user_args {
NS_WalkStackCallback callback;
uint32_t skipFrames;
uint32_t maxFrames;
uint32_t numFrames;
void *closure;
};
static void myinit();
#pragma init (myinit)
static void
myinit()
{
if (! initialized) {
#ifndef __GNUC__
void *handle;
const char *libdem = "libdemangle.so.1";
/* load libdemangle if we can and need to (only try this once) */
if ((handle = dlopen(libdem, RTLD_LAZY)) != nullptr) {
demf = (demf_t *)dlsym(handle,
"cplus_demangle"); /*lint !e611 */
/*
* lint override above is to prevent lint from
* complaining about "suspicious cast".
*/
}
#endif /*__GNUC__*/
}
initialized = 1;
}
static int
load_address(void * pc, void * arg)
{
static struct bucket table[2048];
static mutex_t lock;
struct bucket * ptr;
struct my_user_args * args = (struct my_user_args *) arg;
unsigned int val = NS_PTR_TO_INT32(pc);
ptr = table + ((val >> 2)&2047);
mutex_lock(&lock);
while (ptr->next) {
if (ptr->next->pc == pc)
break;
ptr = ptr->next;
}
int stop = 0;
if (ptr->next) {
mutex_unlock(&lock);
} else {
(args->callback)(pc, args->closure);
args->numFrames++;
if (args->maxFrames != 0 && args->numFrames == args->maxFrames)
stop = 1; // causes us to stop getting frames
ptr->next = newbucket(pc);
mutex_unlock(&lock);
}
return stop;
}
static struct bucket *
newbucket(void * pc)
{
struct bucket * ptr = (struct bucket *)malloc(sizeof(*ptr));
static int index; /* protected by lock in caller */
ptr->index = index++;
ptr->next = nullptr;
ptr->pc = pc;
return (ptr);
}
static struct frame *
csgetframeptr()
{
ucontext_t u;
struct frame *fp;
(void) getcontext(&u);
fp = (struct frame *)
((char *)u.uc_mcontext.gregs[FRAME_PTR_REGISTER] +
STACK_BIAS);
/* make sure to return parents frame pointer.... */
return ((struct frame *)((ulong_t)fp->fr_savfp + STACK_BIAS));
}
static void
cswalkstack(struct frame *fp, int (*operate_func)(void *, void *, void *),
void *usrarg)
{
while (fp != 0 && fp->fr_savpc != 0) {
if (operate_func((void *)fp->fr_savpc, nullptr, usrarg) != 0)
break;
/*
* watch out - libthread stacks look funny at the top
* so they may not have their STACK_BIAS set
*/
fp = (struct frame *)((ulong_t)fp->fr_savfp +
(fp->fr_savfp?(ulong_t)STACK_BIAS:0));
}
}
static void
cs_operate(int (*operate_func)(void *, void *, void *), void * usrarg)
{
cswalkstack(csgetframeptr(), operate_func, usrarg);
}
EXPORT_XPCOM_API(nsresult)
NS_StackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
void* aPlatformData)
{
MOZ_ASSERT(!aThread);
MOZ_ASSERT(!aPlatformData);
struct my_user_args args;
StackWalkInitCriticalAddress();
if (!initialized) {
myinit();
}
args.callback = aCallback;
args.skipFrames = aSkipFrames; /* XXX Not handled! */
args.maxFrames = aMaxFrames;
args.numFrames = 0;
args.closure = aClosure;
cs_operate(load_address, &args);
return args.numFrames == 0 ? NS_ERROR_FAILURE : NS_OK;
}
EXPORT_XPCOM_API(nsresult)
NS_DescribeCodeAddress(void* aPC, nsCodeAddressDetails* aDetails)
{
aDetails->library[0] = '\0';
aDetails->loffset = 0;
aDetails->filename[0] = '\0';
aDetails->lineno = 0;
aDetails->function[0] = '\0';
aDetails->foffset = 0;
char dembuff[4096];
Dl_info info;
if (dladdr(aPC, & info)) {
if (info.dli_fname) {
PL_strncpyz(aDetails->library, info.dli_fname,
sizeof(aDetails->library));
aDetails->loffset = (char*)aPC - (char*)info.dli_fbase;
}
if (info.dli_sname) {
aDetails->foffset = (char*)aPC - (char*)info.dli_saddr;
#ifdef __GNUC__
DemangleSymbol(info.dli_sname, dembuff, sizeof(dembuff));
#else
if (!demf || demf(info.dli_sname, dembuff, sizeof(dembuff))) {
dembuff[0] = 0;
}
#endif /*__GNUC__*/
PL_strncpyz(aDetails->function,
(dembuff[0] != '\0') ? dembuff : info.dli_sname,
sizeof(aDetails->function));
}
}
return NS_OK;
}
EXPORT_XPCOM_API(nsresult)
NS_FormatCodeAddressDetails(void* aPC, const nsCodeAddressDetails* aDetails,
char* aBuffer, uint32_t aBufferSize)
{
snprintf(aBuffer, aBufferSize, "%p %s:%s+0x%lx\n",
aPC,
aDetails->library[0] ? aDetails->library : "??",
aDetails->function[0] ? aDetails->function : "??",
aDetails->foffset);
return NS_OK;
}
#else // not __sun-specific
#if __GLIBC__ > 2 || __GLIBC_MINOR > 1
#define HAVE___LIBC_STACK_END 1
#else
#define HAVE___LIBC_STACK_END 0
#endif
#if HAVE___LIBC_STACK_END
extern void* __libc_stack_end; // from ld-linux.so
#endif
namespace mozilla {
nsresult
FramePointerStackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, void** bp,
void* aStackEnd)
{
// Stack walking code courtesy Kipp's "leaky".
int32_t skip = aSkipFrames;
uint32_t numFrames = 0;
while (1) {
void** next = (void**)*bp;
// bp may not be a frame pointer on i386 if code was compiled with
// -fomit-frame-pointer, so do some sanity checks.
// (bp should be a frame pointer on ppc(64) but checking anyway may help
// a little if the stack has been corrupted.)
// We don't need to check against the begining of the stack because
// we can assume that bp > sp
if (next <= bp ||
next > aStackEnd ||
(long(next) & 3)) {
break;
}
#if (defined(__ppc__) && defined(XP_MACOSX)) || defined(__powerpc64__)
// ppc mac or powerpc64 linux
void* pc = *(bp + 2);
bp += 3;
#else // i386 or powerpc32 linux
void* pc = *(bp + 1);
bp += 2;
#endif
if (IsCriticalAddress(pc)) {
return NS_ERROR_UNEXPECTED;
}
if (--skip < 0) {
// Assume that the SP points to the BP of the function
// it called. We can't know the exact location of the SP
// but this should be sufficient for our use the SP
// to order elements on the stack.
(*aCallback)(pc, bp, aClosure);
numFrames++;
if (aMaxFrames != 0 && numFrames == aMaxFrames) {
break;
}
}
bp = next;
}
return numFrames == 0 ? NS_ERROR_FAILURE : NS_OK;
}
}
#define X86_OR_PPC (defined(__i386) || defined(PPC) || defined(__ppc__))
#if X86_OR_PPC && (NSSTACKWALK_SUPPORTS_MACOSX || NSSTACKWALK_SUPPORTS_LINUX) // i386 or PPC Linux or Mac stackwalking code
EXPORT_XPCOM_API(nsresult)
NS_StackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
void* aPlatformData)
{
MOZ_ASSERT(!aThread);
MOZ_ASSERT(!aPlatformData);
StackWalkInitCriticalAddress();
// Get the frame pointer
void** bp;
#if defined(__i386)
__asm__("movl %%ebp, %0" : "=g"(bp));
#else
// It would be nice if this worked uniformly, but at least on i386 and
// x86_64, it stopped working with gcc 4.1, because it points to the
// end of the saved registers instead of the start.
bp = (void**)__builtin_frame_address(0);
#endif
void* stackEnd;
#if HAVE___LIBC_STACK_END
stackEnd = __libc_stack_end;
#else
stackEnd = reinterpret_cast<void*>(-1);
#endif
return FramePointerStackWalk(aCallback, aSkipFrames, aMaxFrames,
aClosure, bp, stackEnd);
}
#elif defined(HAVE__UNWIND_BACKTRACE)
// libgcc_s.so symbols _Unwind_Backtrace@@GCC_3.3 and _Unwind_GetIP@@GCC_3.0
#include <unwind.h>
struct unwind_info
{
NS_WalkStackCallback callback;
int skip;
int maxFrames;
int numFrames;
bool isCriticalAbort;
void* closure;
};
static _Unwind_Reason_Code
unwind_callback(struct _Unwind_Context* context, void* closure)
{
unwind_info* info = static_cast<unwind_info*>(closure);
void* pc = reinterpret_cast<void*>(_Unwind_GetIP(context));
// TODO Use something like '_Unwind_GetGR()' to get the stack pointer.
if (IsCriticalAddress(pc)) {
info->isCriticalAbort = true;
// We just want to stop the walk, so any error code will do. Using
// _URC_NORMAL_STOP would probably be the most accurate, but it is not
// defined on Android for ARM.
return _URC_FOREIGN_EXCEPTION_CAUGHT;
}
if (--info->skip < 0) {
(*info->callback)(pc, nullptr, info->closure);
info->numFrames++;
if (info->maxFrames != 0 && info->numFrames == info->maxFrames) {
// Again, any error code that stops the walk will do.
return _URC_FOREIGN_EXCEPTION_CAUGHT;
}
}
return _URC_NO_REASON;
}
EXPORT_XPCOM_API(nsresult)
NS_StackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
void* aPlatformData)
{
MOZ_ASSERT(!aThread);
MOZ_ASSERT(!aPlatformData);
StackWalkInitCriticalAddress();
unwind_info info;
info.callback = aCallback;
info.skip = aSkipFrames + 1;
info.maxFrames = aMaxFrames;
info.numFrames = 0;
info.isCriticalAbort = false;
info.closure = aClosure;
(void)_Unwind_Backtrace(unwind_callback, &info);
// We ignore the return value from _Unwind_Backtrace and instead determine
// the outcome from |info|. There are two main reasons for this:
// - On ARM/Android bionic's _Unwind_Backtrace usually (always?) returns
// _URC_FAILURE. See
// https://bugzilla.mozilla.org/show_bug.cgi?id=717853#c110.
// - If aMaxFrames != 0, we want to stop early, and the only way to do that
// is to make unwind_callback return something other than _URC_NO_REASON,
// which causes _Unwind_Backtrace to return a non-success code.
if (info.isCriticalAbort) {
return NS_ERROR_UNEXPECTED;
}
return info.numFrames == 0 ? NS_ERROR_FAILURE : NS_OK;
}
#endif
EXPORT_XPCOM_API(nsresult)
NS_DescribeCodeAddress(void* aPC, nsCodeAddressDetails* aDetails)
{
aDetails->library[0] = '\0';
aDetails->loffset = 0;
aDetails->filename[0] = '\0';
aDetails->lineno = 0;
aDetails->function[0] = '\0';
aDetails->foffset = 0;
Dl_info info;
int ok = dladdr(aPC, &info);
if (!ok) {
return NS_OK;
}
PL_strncpyz(aDetails->library, info.dli_fname, sizeof(aDetails->library));
aDetails->loffset = (char*)aPC - (char*)info.dli_fbase;
const char* symbol = info.dli_sname;
if (!symbol || symbol[0] == '\0') {
return NS_OK;
}
DemangleSymbol(symbol, aDetails->function, sizeof(aDetails->function));
if (aDetails->function[0] == '\0') {
// Just use the mangled symbol if demangling failed.
PL_strncpyz(aDetails->function, symbol, sizeof(aDetails->function));
}
aDetails->foffset = (char*)aPC - (char*)info.dli_saddr;
return NS_OK;
}
EXPORT_XPCOM_API(nsresult)
NS_FormatCodeAddressDetails(void* aPC, const nsCodeAddressDetails* aDetails,
char* aBuffer, uint32_t aBufferSize)
{
if (!aDetails->library[0]) {
snprintf(aBuffer, aBufferSize, "UNKNOWN %p\n", aPC);
} else if (!aDetails->function[0]) {
snprintf(aBuffer, aBufferSize, "UNKNOWN [%s +0x%08" PRIXPTR "]\n",
aDetails->library, aDetails->loffset);
} else {
snprintf(aBuffer, aBufferSize, "%s+0x%08" PRIXPTR
" [%s +0x%08" PRIXPTR "]\n",
aDetails->function, aDetails->foffset,
aDetails->library, aDetails->loffset);
}
return NS_OK;
}
#endif
#else // unsupported platform.
EXPORT_XPCOM_API(nsresult)
NS_StackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
void* aPlatformData)
{
MOZ_ASSERT(!aThread);
MOZ_ASSERT(!aPlatformData);
return NS_ERROR_NOT_IMPLEMENTED;
}
namespace mozilla {
nsresult
FramePointerStackWalk(NS_WalkStackCallback aCallback, uint32_t aSkipFrames,
void* aClosure, void** aBp)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
}
EXPORT_XPCOM_API(nsresult)
NS_DescribeCodeAddress(void* aPC, nsCodeAddressDetails* aDetails)
{
aDetails->library[0] = '\0';
aDetails->loffset = 0;
aDetails->filename[0] = '\0';
aDetails->lineno = 0;
aDetails->function[0] = '\0';
aDetails->foffset = 0;
return NS_ERROR_NOT_IMPLEMENTED;
}
EXPORT_XPCOM_API(nsresult)
NS_FormatCodeAddressDetails(void* aPC, const nsCodeAddressDetails* aDetails,
char* aBuffer, uint32_t aBufferSize)
{
aBuffer[0] = '\0';
return NS_ERROR_NOT_IMPLEMENTED;
}
#endif