// Copyright (c) 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <objbase.h>
#include <algorithm>
#include <cassert>
#include <cstdio>
#include "common/windows/string_utils-inl.h"
#include "client/windows/common/ipc_protocol.h"
#include "client/windows/handler/exception_handler.h"
#include "common/windows/guid_string.h"
namespace google_breakpad {
static const int kWaitForHandlerThreadMs = 60000;
static const int kExceptionHandlerThreadInitialStackSize = 64 * 1024;
// As documented on MSDN, on failure SuspendThread returns (DWORD) -1
static const DWORD kFailedToSuspendThread = static_cast<DWORD>(-1);
// This is passed as the context to the MinidumpWriteDump callback.
typedef struct {
AppMemoryList::const_iterator iter;
AppMemoryList::const_iterator end;
} MinidumpCallbackContext;
vector<ExceptionHandler*>* ExceptionHandler::handler_stack_ = NULL;
LONG ExceptionHandler::handler_stack_index_ = 0;
CRITICAL_SECTION ExceptionHandler::handler_stack_critical_section_;
volatile LONG ExceptionHandler::instance_count_ = 0;
ExceptionHandler::ExceptionHandler(const wstring& dump_path,
FilterCallback filter,
MinidumpCallback callback,
void* callback_context,
int handler_types,
MINIDUMP_TYPE dump_type,
const wchar_t* pipe_name,
const CustomClientInfo* custom_info) {
Initialize(dump_path,
filter,
callback,
callback_context,
handler_types,
dump_type,
pipe_name,
NULL, // pipe_handle
NULL, // crash_generation_client
custom_info);
}
ExceptionHandler::ExceptionHandler(const wstring& dump_path,
FilterCallback filter,
MinidumpCallback callback,
void* callback_context,
int handler_types,
MINIDUMP_TYPE dump_type,
HANDLE pipe_handle,
const CustomClientInfo* custom_info) {
Initialize(dump_path,
filter,
callback,
callback_context,
handler_types,
dump_type,
NULL, // pipe_name
pipe_handle,
NULL, // crash_generation_client
custom_info);
}
ExceptionHandler::ExceptionHandler(
const wstring& dump_path,
FilterCallback filter,
MinidumpCallback callback,
void* callback_context,
int handler_types,
CrashGenerationClient* crash_generation_client) {
// The dump_type, pipe_name and custom_info that are passed in to Initialize()
// are not used. The ones set in crash_generation_client are used instead.
Initialize(dump_path,
filter,
callback,
callback_context,
handler_types,
MiniDumpNormal, // dump_type - not used
NULL, // pipe_name - not used
NULL, // pipe_handle
crash_generation_client,
NULL); // custom_info - not used
}
ExceptionHandler::ExceptionHandler(const wstring &dump_path,
FilterCallback filter,
MinidumpCallback callback,
void* callback_context,
int handler_types) {
Initialize(dump_path,
filter,
callback,
callback_context,
handler_types,
MiniDumpNormal,
NULL, // pipe_name
NULL, // pipe_handle
NULL, // crash_generation_client
NULL); // custom_info
}
void ExceptionHandler::Initialize(
const wstring& dump_path,
FilterCallback filter,
MinidumpCallback callback,
void* callback_context,
int handler_types,
MINIDUMP_TYPE dump_type,
const wchar_t* pipe_name,
HANDLE pipe_handle,
CrashGenerationClient* crash_generation_client,
const CustomClientInfo* custom_info) {
LONG instance_count = InterlockedIncrement(&instance_count_);
filter_ = filter;
callback_ = callback;
callback_context_ = callback_context;
dump_path_c_ = NULL;
next_minidump_id_c_ = NULL;
next_minidump_path_c_ = NULL;
dbghelp_module_ = NULL;
minidump_write_dump_ = NULL;
dump_type_ = dump_type;
rpcrt4_module_ = NULL;
uuid_create_ = NULL;
handler_types_ = handler_types;
previous_filter_ = NULL;
#if _MSC_VER >= 1400 // MSVC 2005/8
previous_iph_ = NULL;
#endif // _MSC_VER >= 1400
previous_pch_ = NULL;
handler_thread_ = NULL;
is_shutdown_ = false;
handler_start_semaphore_ = NULL;
handler_finish_semaphore_ = NULL;
requesting_thread_id_ = 0;
exception_info_ = NULL;
assertion_ = NULL;
handler_return_value_ = false;
handle_debug_exceptions_ = false;
consume_invalid_handle_exceptions_ = false;
// Attempt to use out-of-process if user has specified a pipe or a
// crash generation client.
scoped_ptr<CrashGenerationClient> client;
if (crash_generation_client) {
client.reset(crash_generation_client);
} else if (pipe_name) {
client.reset(
new CrashGenerationClient(pipe_name, dump_type_, custom_info));
} else if (pipe_handle) {
client.reset(
new CrashGenerationClient(pipe_handle, dump_type_, custom_info));
}
if (client.get() != NULL) {
// If successful in registering with the monitoring process,
// there is no need to setup in-process crash generation.
if (client->Register()) {
crash_generation_client_.reset(client.release());
}
}
if (!IsOutOfProcess()) {
// Either client did not ask for out-of-process crash generation
// or registration with the server process failed. In either case,
// setup to do in-process crash generation.
// Set synchronization primitives and the handler thread. Each
// ExceptionHandler object gets its own handler thread because that's the
// only way to reliably guarantee sufficient stack space in an exception,
// and it allows an easy way to get a snapshot of the requesting thread's
// context outside of an exception.
InitializeCriticalSection(&handler_critical_section_);
handler_start_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
assert(handler_start_semaphore_ != NULL);
handler_finish_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
assert(handler_finish_semaphore_ != NULL);
// Don't attempt to create the thread if we could not create the semaphores.
if (handler_finish_semaphore_ != NULL && handler_start_semaphore_ != NULL) {
DWORD thread_id;
handler_thread_ = CreateThread(NULL, // lpThreadAttributes
kExceptionHandlerThreadInitialStackSize,
ExceptionHandlerThreadMain,
this, // lpParameter
0, // dwCreationFlags
&thread_id);
assert(handler_thread_ != NULL);
}
dbghelp_module_ = LoadLibrary(L"dbghelp.dll");
if (dbghelp_module_) {
minidump_write_dump_ = reinterpret_cast<MiniDumpWriteDump_type>(
GetProcAddress(dbghelp_module_, "MiniDumpWriteDump"));
}
// Load this library dynamically to not affect existing projects. Most
// projects don't link against this directly, it's usually dynamically
// loaded by dependent code.
rpcrt4_module_ = LoadLibrary(L"rpcrt4.dll");
if (rpcrt4_module_) {
uuid_create_ = reinterpret_cast<UuidCreate_type>(
GetProcAddress(rpcrt4_module_, "UuidCreate"));
}
// set_dump_path calls UpdateNextID. This sets up all of the path and id
// strings, and their equivalent c_str pointers.
set_dump_path(dump_path);
}
// Reserve one element for the instruction memory
AppMemory instruction_memory;
instruction_memory.ptr = NULL;
instruction_memory.length = 0;
app_memory_info_.push_back(instruction_memory);
// There is a race condition here. If the first instance has not yet
// initialized the critical section, the second (and later) instances may
// try to use uninitialized critical section object. The feature of multiple
// instances in one module is not used much, so leave it as is for now.
// One way to solve this in the current design (that is, keeping the static
// handler stack) is to use spin locks with volatile bools to synchronize
// the handler stack. This works only if the compiler guarantees to generate
// cache coherent code for volatile.
// TODO(munjal): Fix this in a better way by changing the design if possible.
// Lazy initialization of the handler_stack_critical_section_
if (instance_count == 1) {
InitializeCriticalSection(&handler_stack_critical_section_);
}
if (handler_types != HANDLER_NONE) {
EnterCriticalSection(&handler_stack_critical_section_);
// The first time an ExceptionHandler that installs a handler is
// created, set up the handler stack.
if (!handler_stack_) {
handler_stack_ = new vector<ExceptionHandler*>();
}
handler_stack_->push_back(this);
if (handler_types & HANDLER_EXCEPTION)
previous_filter_ = SetUnhandledExceptionFilter(HandleException);
#if _MSC_VER >= 1400 // MSVC 2005/8
if (handler_types & HANDLER_INVALID_PARAMETER)
previous_iph_ = _set_invalid_parameter_handler(HandleInvalidParameter);
#endif // _MSC_VER >= 1400
if (handler_types & HANDLER_PURECALL)
previous_pch_ = _set_purecall_handler(HandlePureVirtualCall);
LeaveCriticalSection(&handler_stack_critical_section_);
}
}
ExceptionHandler::~ExceptionHandler() {
if (dbghelp_module_) {
FreeLibrary(dbghelp_module_);
}
if (rpcrt4_module_) {
FreeLibrary(rpcrt4_module_);
}
if (handler_types_ != HANDLER_NONE) {
EnterCriticalSection(&handler_stack_critical_section_);
if (handler_types_ & HANDLER_EXCEPTION)
SetUnhandledExceptionFilter(previous_filter_);
#if _MSC_VER >= 1400 // MSVC 2005/8
if (handler_types_ & HANDLER_INVALID_PARAMETER)
_set_invalid_parameter_handler(previous_iph_);
#endif // _MSC_VER >= 1400
if (handler_types_ & HANDLER_PURECALL)
_set_purecall_handler(previous_pch_);
if (handler_stack_->back() == this) {
handler_stack_->pop_back();
} else {
// TODO(mmentovai): use advapi32!ReportEvent to log the warning to the
// system's application event log.
fprintf(stderr, "warning: removing Breakpad handler out of order\n");
vector<ExceptionHandler*>::iterator iterator = handler_stack_->begin();
while (iterator != handler_stack_->end()) {
if (*iterator == this) {
iterator = handler_stack_->erase(iterator);
} else {
++iterator;
}
}
}
if (handler_stack_->empty()) {
// When destroying the last ExceptionHandler that installed a handler,
// clean up the handler stack.
delete handler_stack_;
handler_stack_ = NULL;
}
LeaveCriticalSection(&handler_stack_critical_section_);
}
// Some of the objects were only initialized if out of process
// registration was not done.
if (!IsOutOfProcess()) {
#ifdef BREAKPAD_NO_TERMINATE_THREAD
// Clean up the handler thread and synchronization primitives. The handler
// thread is either waiting on the semaphore to handle a crash or it is
// handling a crash. Coming out of the wait is fast but wait more in the
// eventuality a crash is handled. This compilation option results in a
// deadlock if the exception handler is destroyed while executing code
// inside DllMain.
is_shutdown_ = true;
ReleaseSemaphore(handler_start_semaphore_, 1, NULL);
WaitForSingleObject(handler_thread_, kWaitForHandlerThreadMs);
#else
TerminateThread(handler_thread_, 1);
#endif // BREAKPAD_NO_TERMINATE_THREAD
CloseHandle(handler_thread_);
handler_thread_ = NULL;
DeleteCriticalSection(&handler_critical_section_);
CloseHandle(handler_start_semaphore_);
CloseHandle(handler_finish_semaphore_);
}
// There is a race condition in the code below: if this instance is
// deleting the static critical section and a new instance of the class
// is created, then there is a possibility that the critical section be
// initialized while the same critical section is being deleted. Given the
// usage pattern for the code, this race condition is unlikely to hit, but it
// is a race condition nonetheless.
if (InterlockedDecrement(&instance_count_) == 0) {
DeleteCriticalSection(&handler_stack_critical_section_);
}
}
bool ExceptionHandler::RequestUpload(DWORD crash_id) {
return crash_generation_client_->RequestUpload(crash_id);
}
// static
DWORD ExceptionHandler::ExceptionHandlerThreadMain(void* lpParameter) {
ExceptionHandler* self = reinterpret_cast<ExceptionHandler *>(lpParameter);
assert(self);
assert(self->handler_start_semaphore_ != NULL);
assert(self->handler_finish_semaphore_ != NULL);
while (true) {
if (WaitForSingleObject(self->handler_start_semaphore_, INFINITE) ==
WAIT_OBJECT_0) {
// Perform the requested action.
if (self->is_shutdown_) {
// The instance of the exception handler is being destroyed.
break;
} else {
self->handler_return_value_ =
self->WriteMinidumpWithException(self->requesting_thread_id_,
self->exception_info_,
self->assertion_);
}
// Allow the requesting thread to proceed.
ReleaseSemaphore(self->handler_finish_semaphore_, 1, NULL);
}
}
// This statement is not reached when the thread is unconditionally
// terminated by the ExceptionHandler destructor.
return 0;
}
// HandleException and HandleInvalidParameter must create an
// AutoExceptionHandler object to maintain static state and to determine which
// ExceptionHandler instance to use. The constructor locates the correct
// instance, and makes it available through get_handler(). The destructor
// restores the state in effect prior to allocating the AutoExceptionHandler.
class AutoExceptionHandler {
public:
AutoExceptionHandler() {
// Increment handler_stack_index_ so that if another Breakpad handler is
// registered using this same HandleException function, and it needs to be
// called while this handler is running (either because this handler
// declines to handle the exception, or an exception occurs during
// handling), HandleException will find the appropriate ExceptionHandler
// object in handler_stack_ to deliver the exception to.
//
// Because handler_stack_ is addressed in reverse (as |size - index|),
// preincrementing handler_stack_index_ avoids needing to subtract 1 from
// the argument to |at|.
//
// The index is maintained instead of popping elements off of the handler
// stack and pushing them at the end of this method. This avoids ruining
// the order of elements in the stack in the event that some other thread
// decides to manipulate the handler stack (such as creating a new
// ExceptionHandler object) while an exception is being handled.
EnterCriticalSection(&ExceptionHandler::handler_stack_critical_section_);
handler_ = ExceptionHandler::handler_stack_->at(
ExceptionHandler::handler_stack_->size() -
++ExceptionHandler::handler_stack_index_);
// In case another exception occurs while this handler is doing its thing,
// it should be delivered to the previous filter.
SetUnhandledExceptionFilter(handler_->previous_filter_);
#if _MSC_VER >= 1400 // MSVC 2005/8
_set_invalid_parameter_handler(handler_->previous_iph_);
#endif // _MSC_VER >= 1400
_set_purecall_handler(handler_->previous_pch_);
}
~AutoExceptionHandler() {
// Put things back the way they were before entering this handler.
SetUnhandledExceptionFilter(ExceptionHandler::HandleException);
#if _MSC_VER >= 1400 // MSVC 2005/8
_set_invalid_parameter_handler(ExceptionHandler::HandleInvalidParameter);
#endif // _MSC_VER >= 1400
_set_purecall_handler(ExceptionHandler::HandlePureVirtualCall);
--ExceptionHandler::handler_stack_index_;
LeaveCriticalSection(&ExceptionHandler::handler_stack_critical_section_);
}
ExceptionHandler* get_handler() const { return handler_; }
private:
ExceptionHandler* handler_;
};
// static
LONG ExceptionHandler::HandleException(EXCEPTION_POINTERS* exinfo) {
AutoExceptionHandler auto_exception_handler;
ExceptionHandler* current_handler = auto_exception_handler.get_handler();
// Ignore EXCEPTION_BREAKPOINT and EXCEPTION_SINGLE_STEP exceptions. This
// logic will short-circuit before calling WriteMinidumpOnHandlerThread,
// allowing something else to handle the breakpoint without incurring the
// overhead transitioning to and from the handler thread. This behavior
// can be overridden by calling ExceptionHandler::set_handle_debug_exceptions.
DWORD code = exinfo->ExceptionRecord->ExceptionCode;
LONG action;
bool is_debug_exception = (code == EXCEPTION_BREAKPOINT) ||
(code == EXCEPTION_SINGLE_STEP);
if (code == EXCEPTION_INVALID_HANDLE &&
current_handler->consume_invalid_handle_exceptions_) {
return EXCEPTION_CONTINUE_EXECUTION;
}
bool success = false;
if (!is_debug_exception ||
current_handler->get_handle_debug_exceptions()) {
// If out-of-proc crash handler client is available, we have to use that
// to generate dump and we cannot fall back on in-proc dump generation
// because we never prepared for an in-proc dump generation
// In case of out-of-process dump generation, directly call
// WriteMinidumpWithException since there is no separate thread running.
if (current_handler->IsOutOfProcess()) {
success = current_handler->WriteMinidumpWithException(
GetCurrentThreadId(),
exinfo,
NULL);
} else {
success = current_handler->WriteMinidumpOnHandlerThread(exinfo, NULL);
}
}
// The handler fully handled the exception. Returning
// EXCEPTION_EXECUTE_HANDLER indicates this to the system, and usually
// results in the application being terminated.
//
// Note: If the application was launched from within the Cygwin
// environment, returning EXCEPTION_EXECUTE_HANDLER seems to cause the
// application to be restarted.
if (success) {
action = EXCEPTION_EXECUTE_HANDLER;
} else {
// There was an exception, it was a breakpoint or something else ignored
// above, or it was passed to the handler, which decided not to handle it.
// This could be because the filter callback didn't want it, because
// minidump writing failed for some reason, or because the post-minidump
// callback function indicated failure. Give the previous handler a
// chance to do something with the exception. If there is no previous
// handler, return EXCEPTION_CONTINUE_SEARCH, which will allow a debugger
// or native "crashed" dialog to handle the exception.
if (current_handler->previous_filter_) {
action = current_handler->previous_filter_(exinfo);
} else {
action = EXCEPTION_CONTINUE_SEARCH;
}
}
return action;
}
#if _MSC_VER >= 1400 // MSVC 2005/8
// static
void ExceptionHandler::HandleInvalidParameter(const wchar_t* expression,
const wchar_t* function,
const wchar_t* file,
unsigned int line,
uintptr_t reserved) {
// This is an invalid parameter, not an exception. It's safe to play with
// sprintf here.
AutoExceptionHandler auto_exception_handler;
ExceptionHandler* current_handler = auto_exception_handler.get_handler();
MDRawAssertionInfo assertion;
memset(&assertion, 0, sizeof(assertion));
_snwprintf_s(reinterpret_cast<wchar_t*>(assertion.expression),
sizeof(assertion.expression) / sizeof(assertion.expression[0]),
_TRUNCATE, L"%s", expression);
_snwprintf_s(reinterpret_cast<wchar_t*>(assertion.function),
sizeof(assertion.function) / sizeof(assertion.function[0]),
_TRUNCATE, L"%s", function);
_snwprintf_s(reinterpret_cast<wchar_t*>(assertion.file),
sizeof(assertion.file) / sizeof(assertion.file[0]),
_TRUNCATE, L"%s", file);
assertion.line = line;
assertion.type = MD_ASSERTION_INFO_TYPE_INVALID_PARAMETER;
// Make up an exception record for the current thread and CPU context
// to make it possible for the crash processor to classify these
// as do regular crashes, and to make it humane for developers to
// analyze them.
EXCEPTION_RECORD exception_record = {};
CONTEXT exception_context = {};
EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };
::RtlCaptureContext(&exception_context);
exception_record.ExceptionCode = STATUS_INVALID_PARAMETER;
// We store pointers to the the expression and function strings,
// and the line as exception parameters to make them easy to
// access by the developer on the far side.
exception_record.NumberParameters = 3;
exception_record.ExceptionInformation[0] =
reinterpret_cast<ULONG_PTR>(&assertion.expression);
exception_record.ExceptionInformation[1] =
reinterpret_cast<ULONG_PTR>(&assertion.file);
exception_record.ExceptionInformation[2] = assertion.line;
bool success = false;
// In case of out-of-process dump generation, directly call
// WriteMinidumpWithException since there is no separate thread running.
if (current_handler->IsOutOfProcess()) {
success = current_handler->WriteMinidumpWithException(
GetCurrentThreadId(),
&exception_ptrs,
&assertion);
} else {
success = current_handler->WriteMinidumpOnHandlerThread(&exception_ptrs,
&assertion);
}
if (!success) {
if (current_handler->previous_iph_) {
// The handler didn't fully handle the exception. Give it to the
// previous invalid parameter handler.
current_handler->previous_iph_(expression,
function,
file,
line,
reserved);
} else {
// If there's no previous handler, pass the exception back in to the
// invalid parameter handler's core. That's the routine that called this
// function, but now, since this function is no longer registered (and in
// fact, no function at all is registered), this will result in the
// default code path being taken: _CRT_DEBUGGER_HOOK and _invoke_watson.
// Use _invalid_parameter where it exists (in _DEBUG builds) as it passes
// more information through. In non-debug builds, it is not available,
// so fall back to using _invalid_parameter_noinfo. See invarg.c in the
// CRT source.
#ifdef _DEBUG
_invalid_parameter(expression, function, file, line, reserved);
#else // _DEBUG
_invalid_parameter_noinfo();
#endif // _DEBUG
}
}
// The handler either took care of the invalid parameter problem itself,
// or passed it on to another handler. "Swallow" it by exiting, paralleling
// the behavior of "swallowing" exceptions.
exit(0);
}
#endif // _MSC_VER >= 1400
// static
void ExceptionHandler::HandlePureVirtualCall() {
// This is an pure virtual function call, not an exception. It's safe to
// play with sprintf here.
AutoExceptionHandler auto_exception_handler;
ExceptionHandler* current_handler = auto_exception_handler.get_handler();
MDRawAssertionInfo assertion;
memset(&assertion, 0, sizeof(assertion));
assertion.type = MD_ASSERTION_INFO_TYPE_PURE_VIRTUAL_CALL;
// Make up an exception record for the current thread and CPU context
// to make it possible for the crash processor to classify these
// as do regular crashes, and to make it humane for developers to
// analyze them.
EXCEPTION_RECORD exception_record = {};
CONTEXT exception_context = {};
EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };
::RtlCaptureContext(&exception_context);
exception_record.ExceptionCode = STATUS_NONCONTINUABLE_EXCEPTION;
// We store pointers to the the expression and function strings,
// and the line as exception parameters to make them easy to
// access by the developer on the far side.
exception_record.NumberParameters = 3;
exception_record.ExceptionInformation[0] =
reinterpret_cast<ULONG_PTR>(&assertion.expression);
exception_record.ExceptionInformation[1] =
reinterpret_cast<ULONG_PTR>(&assertion.file);
exception_record.ExceptionInformation[2] = assertion.line;
bool success = false;
// In case of out-of-process dump generation, directly call
// WriteMinidumpWithException since there is no separate thread running.
if (current_handler->IsOutOfProcess()) {
success = current_handler->WriteMinidumpWithException(
GetCurrentThreadId(),
&exception_ptrs,
&assertion);
} else {
success = current_handler->WriteMinidumpOnHandlerThread(&exception_ptrs,
&assertion);
}
if (!success) {
if (current_handler->previous_pch_) {
// The handler didn't fully handle the exception. Give it to the
// previous purecall handler.
current_handler->previous_pch_();
} else {
// If there's no previous handler, return and let _purecall handle it.
// This will just put up an assertion dialog.
return;
}
}
// The handler either took care of the invalid parameter problem itself,
// or passed it on to another handler. "Swallow" it by exiting, paralleling
// the behavior of "swallowing" exceptions.
exit(0);
}
bool ExceptionHandler::WriteMinidumpOnHandlerThread(
EXCEPTION_POINTERS* exinfo, MDRawAssertionInfo* assertion) {
EnterCriticalSection(&handler_critical_section_);
// There isn't much we can do if the handler thread
// was not successfully created.
if (handler_thread_ == NULL) {
LeaveCriticalSection(&handler_critical_section_);
return false;
}
// The handler thread should only be created when the semaphores are valid.
assert(handler_start_semaphore_ != NULL);
assert(handler_finish_semaphore_ != NULL);
// Set up data to be passed in to the handler thread.
requesting_thread_id_ = GetCurrentThreadId();
exception_info_ = exinfo;
assertion_ = assertion;
// This causes the handler thread to call WriteMinidumpWithException.
ReleaseSemaphore(handler_start_semaphore_, 1, NULL);
// Wait until WriteMinidumpWithException is done and collect its return value.
WaitForSingleObject(handler_finish_semaphore_, INFINITE);
bool status = handler_return_value_;
// Clean up.
requesting_thread_id_ = 0;
exception_info_ = NULL;
assertion_ = NULL;
LeaveCriticalSection(&handler_critical_section_);
return status;
}
bool ExceptionHandler::WriteMinidump() {
// Make up an exception record for the current thread and CPU context
// to make it possible for the crash processor to classify these
// as do regular crashes, and to make it humane for developers to
// analyze them.
EXCEPTION_RECORD exception_record = {};
CONTEXT exception_context = {};
EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };
::RtlCaptureContext(&exception_context);
exception_record.ExceptionCode = STATUS_NONCONTINUABLE_EXCEPTION;
return WriteMinidumpForException(&exception_ptrs);
}
bool ExceptionHandler::WriteMinidumpForException(EXCEPTION_POINTERS* exinfo) {
// In case of out-of-process dump generation, directly call
// WriteMinidumpWithException since there is no separate thread running.
if (IsOutOfProcess()) {
return WriteMinidumpWithException(GetCurrentThreadId(),
exinfo,
NULL);
}
bool success = WriteMinidumpOnHandlerThread(exinfo, NULL);
UpdateNextID();
return success;
}
// static
bool ExceptionHandler::WriteMinidump(const wstring &dump_path,
MinidumpCallback callback,
void* callback_context) {
ExceptionHandler handler(dump_path, NULL, callback, callback_context,
HANDLER_NONE);
return handler.WriteMinidump();
}
// static
bool ExceptionHandler::WriteMinidumpForChild(HANDLE child,
DWORD child_blamed_thread,
const wstring& dump_path,
MinidumpCallback callback,
void* callback_context) {
EXCEPTION_RECORD ex;
CONTEXT ctx;
EXCEPTION_POINTERS exinfo = { NULL, NULL };
DWORD last_suspend_count = kFailedToSuspendThread;
HANDLE child_thread_handle = OpenThread(THREAD_GET_CONTEXT |
THREAD_QUERY_INFORMATION |
THREAD_SUSPEND_RESUME,
FALSE,
child_blamed_thread);
// This thread may have died already, so not opening the handle is a
// non-fatal error.
if (child_thread_handle != NULL) {
last_suspend_count = SuspendThread(child_thread_handle);
if (last_suspend_count != kFailedToSuspendThread) {
ctx.ContextFlags = CONTEXT_ALL;
if (GetThreadContext(child_thread_handle, &ctx)) {
memset(&ex, 0, sizeof(ex));
ex.ExceptionCode = EXCEPTION_BREAKPOINT;
#if defined(_M_IX86)
ex.ExceptionAddress = reinterpret_cast<PVOID>(ctx.Eip);
#elif defined(_M_X64)
ex.ExceptionAddress = reinterpret_cast<PVOID>(ctx.Rip);
#endif
exinfo.ExceptionRecord = &ex;
exinfo.ContextRecord = &ctx;
}
}
}
ExceptionHandler handler(dump_path, NULL, callback, callback_context,
HANDLER_NONE);
bool success = handler.WriteMinidumpWithExceptionForProcess(
child_blamed_thread,
exinfo.ExceptionRecord ? &exinfo : NULL,
NULL, child, false);
if (last_suspend_count != kFailedToSuspendThread) {
ResumeThread(child_thread_handle);
}
CloseHandle(child_thread_handle);
if (callback) {
success = callback(handler.dump_path_c_, handler.next_minidump_id_c_,
callback_context, NULL, NULL, success);
}
return success;
}
bool ExceptionHandler::WriteMinidumpWithException(
DWORD requesting_thread_id,
EXCEPTION_POINTERS* exinfo,
MDRawAssertionInfo* assertion) {
// Give user code a chance to approve or prevent writing a minidump. If the
// filter returns false, don't handle the exception at all. If this method
// was called as a result of an exception, returning false will cause
// HandleException to call any previous handler or return
// EXCEPTION_CONTINUE_SEARCH on the exception thread, allowing it to appear
// as though this handler were not present at all.
if (filter_ && !filter_(callback_context_, exinfo, assertion)) {
return false;
}
bool success = false;
if (IsOutOfProcess()) {
success = crash_generation_client_->RequestDump(exinfo, assertion);
} else {
success = WriteMinidumpWithExceptionForProcess(requesting_thread_id,
exinfo,
assertion,
GetCurrentProcess(),
true);
}
if (callback_) {
// TODO(munjal): In case of out-of-process dump generation, both
// dump_path_c_ and next_minidump_id_ will be NULL. For out-of-process
// scenario, the server process ends up creating the dump path and dump
// id so they are not known to the client.
success = callback_(dump_path_c_, next_minidump_id_c_, callback_context_,
exinfo, assertion, success);
}
return success;
}
// static
BOOL CALLBACK ExceptionHandler::MinidumpWriteDumpCallback(
PVOID context,
const PMINIDUMP_CALLBACK_INPUT callback_input,
PMINIDUMP_CALLBACK_OUTPUT callback_output) {
switch (callback_input->CallbackType) {
case MemoryCallback: {
MinidumpCallbackContext* callback_context =
reinterpret_cast<MinidumpCallbackContext*>(context);
if (callback_context->iter == callback_context->end)
return FALSE;
// Include the specified memory region.
callback_output->MemoryBase = callback_context->iter->ptr;
callback_output->MemorySize = callback_context->iter->length;
callback_context->iter++;
return TRUE;
}
// Include all modules.
case IncludeModuleCallback:
case ModuleCallback:
return TRUE;
// Include all threads.
case IncludeThreadCallback:
case ThreadCallback:
return TRUE;
// Stop receiving cancel callbacks.
case CancelCallback:
callback_output->CheckCancel = FALSE;
callback_output->Cancel = FALSE;
return TRUE;
}
// Ignore other callback types.
return FALSE;
}
bool ExceptionHandler::WriteMinidumpWithExceptionForProcess(
DWORD requesting_thread_id,
EXCEPTION_POINTERS* exinfo,
MDRawAssertionInfo* assertion,
HANDLE process,
bool write_requester_stream) {
bool success = false;
if (minidump_write_dump_) {
HANDLE dump_file = CreateFile(next_minidump_path_c_,
GENERIC_WRITE,
0, // no sharing
NULL,
CREATE_NEW, // fail if exists
FILE_ATTRIBUTE_NORMAL,
NULL);
if (dump_file != INVALID_HANDLE_VALUE) {
MINIDUMP_EXCEPTION_INFORMATION except_info;
except_info.ThreadId = requesting_thread_id;
except_info.ExceptionPointers = exinfo;
except_info.ClientPointers = FALSE;
// Leave room in user_stream_array for possible breakpad and
// assertion info streams.
MINIDUMP_USER_STREAM user_stream_array[2];
MINIDUMP_USER_STREAM_INFORMATION user_streams;
user_streams.UserStreamCount = 0;
user_streams.UserStreamArray = user_stream_array;
if (write_requester_stream) {
// Add an MDRawBreakpadInfo stream to the minidump, to provide
// additional information about the exception handler to the Breakpad
// processor. The information will help the processor determine which
// threads are relevant. The Breakpad processor does not require this
// information but can function better with Breakpad-generated dumps
// when it is present. The native debugger is not harmed by the
// presence of this information.
MDRawBreakpadInfo breakpad_info;
breakpad_info.validity = MD_BREAKPAD_INFO_VALID_DUMP_THREAD_ID |
MD_BREAKPAD_INFO_VALID_REQUESTING_THREAD_ID;
breakpad_info.dump_thread_id = GetCurrentThreadId();
breakpad_info.requesting_thread_id = requesting_thread_id;
int index = user_streams.UserStreamCount;
user_stream_array[index].Type = MD_BREAKPAD_INFO_STREAM;
user_stream_array[index].BufferSize = sizeof(breakpad_info);
user_stream_array[index].Buffer = &breakpad_info;
++user_streams.UserStreamCount;
}
if (assertion) {
int index = user_streams.UserStreamCount;
user_stream_array[index].Type = MD_ASSERTION_INFO_STREAM;
user_stream_array[index].BufferSize = sizeof(MDRawAssertionInfo);
user_stream_array[index].Buffer = assertion;
++user_streams.UserStreamCount;
}
// Older versions of DbgHelp.dll don't correctly put the memory around
// the faulting instruction pointer into the minidump. This
// callback will ensure that it gets included.
if (exinfo) {
// Find a memory region of 256 bytes centered on the
// faulting instruction pointer.
const ULONG64 instruction_pointer =
#if defined(_M_IX86)
exinfo->ContextRecord->Eip;
#elif defined(_M_AMD64)
exinfo->ContextRecord->Rip;
#else
#error Unsupported platform
#endif
MEMORY_BASIC_INFORMATION info;
if (VirtualQueryEx(process,
reinterpret_cast<LPCVOID>(instruction_pointer),
&info,
sizeof(MEMORY_BASIC_INFORMATION)) != 0 &&
info.State == MEM_COMMIT) {
// Attempt to get 128 bytes before and after the instruction
// pointer, but settle for whatever's available up to the
// boundaries of the memory region.
const ULONG64 kIPMemorySize = 256;
ULONG64 base =
(std::max)(reinterpret_cast<ULONG64>(info.BaseAddress),
instruction_pointer - (kIPMemorySize / 2));
ULONG64 end_of_range =
(std::min)(instruction_pointer + (kIPMemorySize / 2),
reinterpret_cast<ULONG64>(info.BaseAddress)
+ info.RegionSize);
ULONG size = static_cast<ULONG>(end_of_range - base);
AppMemory& elt = app_memory_info_.front();
elt.ptr = base;
elt.length = size;
}
}
MinidumpCallbackContext context;
context.iter = app_memory_info_.begin();
context.end = app_memory_info_.end();
// Skip the reserved element if there was no instruction memory
if (context.iter->ptr == 0) {
context.iter++;
}
MINIDUMP_CALLBACK_INFORMATION callback;
callback.CallbackRoutine = MinidumpWriteDumpCallback;
callback.CallbackParam = reinterpret_cast<void*>(&context);
// The explicit comparison to TRUE avoids a warning (C4800).
success = (minidump_write_dump_(process,
GetProcessId(process),
dump_file,
dump_type_,
exinfo ? &except_info : NULL,
&user_streams,
&callback) == TRUE);
CloseHandle(dump_file);
}
}
return success;
}
void ExceptionHandler::UpdateNextID() {
assert(uuid_create_);
UUID id = {0};
if (uuid_create_) {
uuid_create_(&id);
}
next_minidump_id_ = GUIDString::GUIDToWString(&id);
next_minidump_id_c_ = next_minidump_id_.c_str();
wchar_t minidump_path[MAX_PATH];
swprintf(minidump_path, MAX_PATH, L"%s\\%s.dmp",
dump_path_c_, next_minidump_id_c_);
// remove when VC++7.1 is no longer supported
minidump_path[MAX_PATH - 1] = L'\0';
next_minidump_path_ = minidump_path;
next_minidump_path_c_ = next_minidump_path_.c_str();
}
void ExceptionHandler::RegisterAppMemory(void* ptr, size_t length) {
AppMemoryList::iterator iter =
std::find(app_memory_info_.begin(), app_memory_info_.end(), ptr);
if (iter != app_memory_info_.end()) {
// Don't allow registering the same pointer twice.
return;
}
AppMemory app_memory;
app_memory.ptr = reinterpret_cast<ULONG64>(ptr);
app_memory.length = static_cast<ULONG>(length);
app_memory_info_.push_back(app_memory);
}
void ExceptionHandler::UnregisterAppMemory(void* ptr) {
AppMemoryList::iterator iter =
std::find(app_memory_info_.begin(), app_memory_info_.end(), ptr);
if (iter != app_memory_info_.end()) {
app_memory_info_.erase(iter);
}
}
} // namespace google_breakpad