KisAndroidCrashHandler Namespace Reference

Functions
void	crash_callback (int sig, siginfo_t *info, void *ucontext)
void	dump_backtrace (siginfo_t *info, void *ucontext)
const char *	get_signal_name (const int signo)
void	handler_init ()

Variables
static const char *	crashlog_path = path.c_str()
static bool	g_handling_crash = false
static QMap< int, struct sigaction >	g_old_actions
static const std::string	path
static const std::array< int, 6 >	signals = {SIGABRT, SIGBUS, SIGFPE, SIGSEGV, SIGSYS, SIGTERM}

Function Documentation

crash_callback()

void KisAndroidCrashHandler::crash_callback	(	int	sig,
		siginfo_t *	info,
		void *	ucontext )

Definition at line 102 of file KisAndroidCrashHandler.cpp.

{
    // to prevent second invocation of our signal handler
    if (g_handling_crash) {
        // uninstall the handler for the signal
        sigaction(sig, &g_old_actions[sig], nullptr);
        raise(sig);
        return;
    }
 
    g_handling_crash = true;
    dump_backtrace(info, ucontext);
 
    // uninstall the handler for the signal
    sigaction(sig, &g_old_actions[sig], nullptr);
 
    // invoke the previous handler
    // Some other implementations tend to make call to handler functions
    // directly, seemingly to not make another _slow_ syscall.
    raise(sig);
}

References dump_backtrace(), g_handling_crash, and g_old_actions.

dump_backtrace()

void KisAndroidCrashHandler::dump_backtrace	(	siginfo_t *	info,
		void *	ucontext )

Definition at line 60 of file KisAndroidCrashHandler.cpp.

{
    QScopedPointer<unwindstack::Regs> regs;
    if (ucontext) {
        regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
    } else {
        regs.reset(unwindstack::Regs::CreateFromLocal());
    }
 
    unwindstack::UnwinderFromPid unwinder(256, getpid(), unwindstack::Regs::CurrentArch());
    if (!unwinder.Init()) {
        CRASH_LOGGER("Couldn't initialize the unwinder: %s\n", unwinder.LastErrorCodeString());
        return;
    }
 
    unwinder.SetRegs(regs.data());
    unwinder.Unwind();
 
    std::vector<unwindstack::FrameData> frames = unwinder.frames();
    if (frames.size() == 0) {
        CRASH_LOGGER("Couldn't unwind: %s\t code = %d\n", unwinder.LastErrorCodeString(), unwinder.LastErrorCode());
        return;
    }
 
    const int fd = open(crashlog_path, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR);
 
    std::stringstream header;
    header << "********************** Dumping backtrace **********************\n"
           << "Signal: " << info->si_signo << " (" << get_signal_name(info->si_signo) << ")"
           << " (Code: " << info->si_code << ")"
           << " Time: " << QDateTime::currentDateTimeUtc().toString().toStdString().c_str()
           << " Version: " << KritaVersionWrapper::versionString(true).toStdString().c_str() << "\n";
    write(fd, header.str().c_str(), header.str().size());
 
    for (size_t i = 0; i < frames.size(); ++i) {
        std::string frame = unwinder.FormatFrame(frames[i]) + "\n";
        write(fd, frame.c_str(), frame.size());
    }
    write(fd, "\n", 1);
    close(fd);
}

References CRASH_LOGGER, crashlog_path, get_signal_name(), and KritaVersionWrapper::versionString().

get_signal_name()

const char * KisAndroidCrashHandler::get_signal_name

(

const int

signo

)

Definition at line 40 of file KisAndroidCrashHandler.cpp.

{
    switch (signo) {
    case SIGABRT:
        return "SIGABRT";
    case SIGBUS:
        return "SIGBUS";
    case SIGFPE:
        return "SIGFPE";
    case SIGSEGV:
        return "SIGSEGV";
    case SIGSYS:
        return "SIGSYS";
    case SIGTERM:
        return "SIGTERM";
    default:
        return "?";
    }
}

handler_init()

KRITAGLOBAL_EXPORT void KisAndroidCrashHandler::handler_init

(

)

Definition at line 124 of file KisAndroidCrashHandler.cpp.

{
    // create an alternate stack to make sure we can handle overflows
    stack_t alternate_stack;
    alternate_stack.ss_flags = 0;
    alternate_stack.ss_size = SIGSTKSZ;
    if ((alternate_stack.ss_sp = malloc(SIGSTKSZ)) == nullptr) {
        CRASH_LOGGER("Couldn't allocate memory for alternate stack");
        return;
    }
 
    struct sigaction act = {};
    act.sa_sigaction = crash_callback;
    act.sa_flags = SA_SIGINFO | SA_ONSTACK;
    sigaltstack(&alternate_stack, nullptr);
 
    for (size_t i = 0; i < signals.size(); ++i) {
        sigaction(signals[i], &act, &g_old_actions[signals[i]]);
    }
}

References crash_callback(), CRASH_LOGGER, g_old_actions, and signals.

Variable Documentation

crashlog_path

const char* KisAndroidCrashHandler::crashlog_path = path.c_str()

static

Definition at line 36 of file KisAndroidCrashHandler.cpp.

g_handling_crash

bool KisAndroidCrashHandler::g_handling_crash = false

static

Definition at line 38 of file KisAndroidCrashHandler.cpp.

g_old_actions

QMap<int, struct sigaction> KisAndroidCrashHandler::g_old_actions

static

Definition at line 31 of file KisAndroidCrashHandler.cpp.

path

const std::string KisAndroidCrashHandler::path

static

Initial value:

=
    QString(QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + "/kritacrashlog.txt").toStdString()

Definition at line 34 of file KisAndroidCrashHandler.cpp.

signals

const std::array<int, 6> KisAndroidCrashHandler::signals = {SIGABRT, SIGBUS, SIGFPE, SIGSEGV, SIGSYS, SIGTERM}

static

Definition at line 30 of file KisAndroidCrashHandler.cpp.

{SIGABRT, SIGBUS, SIGFPE, SIGSEGV, SIGSYS, SIGTERM};