void kscrashsentry_reportUserException(const char* name,
const char* reason,
const char* language,
const char* lineOfCode,
const char* stackTrace,
bool terminateProgram)
{
if(g_context == NULL)
{
KSLOG_WARN("User-reported exception sentry is not installed. Exception has not been recorded.");
}
else
{
kscrashsentry_beginHandlingCrash(g_context);
KSLOG_DEBUG("Suspending all threads");
kscrashsentry_suspendThreads();
KSLOG_DEBUG("Fetching call stack.");
int callstackCount = 100;
uintptr_t callstack[callstackCount];
callstackCount = backtrace((void**)callstack, callstackCount);
if(callstackCount <= 0)
{
KSLOG_ERROR("backtrace() returned call stack length of %d", callstackCount);
callstackCount = 0;
}
KSLOG_DEBUG("Filling out context.");
g_context->crashType = KSCrashTypeUserReported;
g_context->offendingThread = ksmach_thread_self();
g_context->registersAreValid = false;
g_context->crashReason = reason;
g_context->stackTrace = callstack;
g_context->stackTraceLength = callstackCount;
g_context->userException.name = name;
g_context->userException.language = language;
g_context->userException.lineOfCode = lineOfCode;
g_context->userException.customStackTrace = stackTrace;
KSLOG_DEBUG("Calling main crash handler.");
g_context->onCrash();
if(terminateProgram)
{
kscrashsentry_uninstall(KSCrashTypeAll);
kscrashsentry_resumeThreads();
abort();
}
else
{
kscrashsentry_clearContext(g_context);
kscrashsentry_resumeThreads();
}
}
}
/** Our custom signal handler.
* Restore the default signal handlers, record the signal information, and
* write a crash report.
* Once we're done, re-raise the signal and let the default handlers deal with
* it.
*
* @param signal The signal that was raised.
*
* @param signalInfo Information about the signal.
*
* @param userContext Other contextual information.
*/
void kssighndl_i_handleSignal(int sigNum,
siginfo_t* signalInfo,
void* userContext)
{
KSLOG_DEBUG("Trapped signal %d", sigNum);
if(g_installed)
{
KSLOG_DEBUG("Signal handler is installed. Continuing signal handling.");
KSLOG_DEBUG("Suspending all threads.");
kscrashsentry_suspendThreads();
if(g_context->handlingCrash)
{
KSLOG_INFO("Detected crash in the crash reporter. Restoring original handlers.");
g_context->crashedDuringCrashHandling = true;
kscrashsentry_uninstall(KSCrashTypeAsyncSafe);
}
g_context->handlingCrash = true;
KSLOG_DEBUG("Filling out context.");
g_context->crashType = KSCrashTypeSignal;
g_context->offendingThread = mach_thread_self();
g_context->registersAreValid = true;
g_context->faultAddress = (uintptr_t)signalInfo->si_addr;
g_context->signal.userContext = userContext;
g_context->signal.signalInfo = signalInfo;
KSLOG_DEBUG("Calling main crash handler.");
g_context->onCrash();
KSLOG_DEBUG("Crash handling complete. Restoring original handlers.");
kscrashsentry_uninstall(KSCrashTypeAsyncSafe);
kscrashsentry_resumeThreads();
}
KSLOG_DEBUG("Re-raising signal for regular handlers to catch.");
// This is technically not allowed, but it works in OSX and iOS.
raise(sigNum);
}
/** Our exception handler thread routine.
* Wait for an exception message, uninstall our exception port, record the
* exception information, and write a report.
*/
void* ksmachexc_i_handleExceptions(void* const userData)
{
#pragma unused(userData)
MachExceptionMessage exceptionMessage = {{0}};
MachReplyMessage replyMessage = {{0}};
const char* threadName = (const char*) userData;
pthread_setname_np(threadName);
if(threadName == kThreadSecondary)
{
KSLOG_DEBUG("This is the secondary thread. Suspending.");
thread_suspend(mach_thread_self());
}
for(;;)
{
KSLOG_DEBUG("Waiting for mach exception");
// Wait for a message.
kern_return_t kr = mach_msg(&exceptionMessage.header,
MACH_RCV_MSG,
0,
sizeof(exceptionMessage),
g_exceptionPort,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if(kr == KERN_SUCCESS)
{
break;
}
// Loop and try again on failure.
KSLOG_ERROR("mach_msg: %s", mach_error_string(kr));
}
KSLOG_DEBUG("Trapped mach exception code 0x%x, subcode 0x%x",
exceptionMessage.code[0], exceptionMessage.code[1]);
if(g_installed)
{
KSLOG_DEBUG("Exception handler is installed. Continuing exception handling.");
KSLOG_DEBUG("Suspending all threads");
kscrashsentry_suspendThreads();
// Switch to the secondary thread if necessary, or uninstall the handler
// to avoid a death loop.
if(mach_thread_self() == pthread_mach_thread_np(g_primaryThread))
{
KSLOG_DEBUG("This is the primary exception thread. Activating secondary thread.");
if(thread_resume(pthread_mach_thread_np(g_secondaryThread)) != KERN_SUCCESS)
{
KSLOG_DEBUG("Could not activate secondary thread. Restoring original exception ports.");
ksmachexc_i_restoreExceptionPorts();
}
}
else
{
KSLOG_DEBUG("This is the secondary exception thread. Restoring original exception ports.");
ksmachexc_i_restoreExceptionPorts();
}
if(g_context->handlingCrash)
{
KSLOG_INFO("Detected crash in the crash reporter. Restoring original handlers.");
// The crash reporter itself crashed. Make a note of this and
// uninstall all handlers so that we don't get stuck in a loop.
g_context->crashedDuringCrashHandling = true;
kscrashsentry_uninstall(KSCrashTypeAsyncSafe);
}
// Fill out crash information
g_context->handlingCrash = true;
KSLOG_DEBUG("Fetching machine state.");
_STRUCT_MCONTEXT machineContext;
if(ksmachexc_i_fetchMachineState(exceptionMessage.thread.name, &machineContext))
{
if(exceptionMessage.exception == EXC_BAD_ACCESS)
{
g_context->faultAddress = ksmach_faultAddress(&machineContext);
}
else
{
g_context->faultAddress = ksmach_instructionAddress(&machineContext);
}
}
KSLOG_DEBUG("Filling out context.");
g_context->crashType = KSCrashTypeMachException;
g_context->offendingThread = exceptionMessage.thread.name;
g_context->registersAreValid = true;
g_context->mach.type = exceptionMessage.exception;
g_context->mach.code = exceptionMessage.code[0];
g_context->mach.subcode = exceptionMessage.code[1];
KSLOG_DEBUG("Calling main crash handler.");
g_context->onCrash();
KSLOG_DEBUG("Crash handling complete. Restoring original handlers.");
kscrashsentry_uninstall(KSCrashTypeAsyncSafe);
kscrashsentry_resumeThreads();
}
KSLOG_DEBUG("Replying to mach exception message.");
// Send a reply saying "I didn't handle this exception".
replyMessage.header = exceptionMessage.header;
replyMessage.NDR = exceptionMessage.NDR;
replyMessage.returnCode = KERN_FAILURE;
mach_msg(&replyMessage.header,
MACH_SEND_MSG,
sizeof(replyMessage),
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
return NULL;
}