static gboolean
native_stack_with_lldb (pid_t crashed_pid, const char **argv, FILE *commands, char* commands_filename)
{
gchar *lldb;
lldb = g_find_program_in_path ("lldb");
if (!lldb)
return FALSE;
argv [0] = lldb;
argv [1] = "--batch";
argv [2] = "--source";
argv [3] = commands_filename;
argv [4] = "--no-lldbinit";
fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
fprintf (commands, "thread list\n");
fprintf (commands, "thread backtrace all\n");
if (mini_get_debug_options ()->verbose_gdb) {
for (int i = 0; i < 32; ++i) {
fprintf (commands, "reg read\n");
fprintf (commands, "frame info\n");
fprintf (commands, "frame variable\n");
fprintf (commands, "up\n");
}
}
fprintf (commands, "detach\n");
fprintf (commands, "quit\n");
return TRUE;
}
static gboolean
native_stack_with_gdb (pid_t crashed_pid, const char **argv, FILE *commands, char* commands_filename)
{
gchar *gdb;
gdb = g_find_program_in_path ("gdb");
if (!gdb)
return FALSE;
argv [0] = gdb;
argv [1] = "-batch";
argv [2] = "-x";
argv [3] = commands_filename;
argv [4] = "-nx";
fprintf (commands, "attach %ld\n", (long) crashed_pid);
fprintf (commands, "info threads\n");
fprintf (commands, "thread apply all bt\n");
if (mini_get_debug_options ()->verbose_gdb) {
for (int i = 0; i < 32; ++i) {
fprintf (commands, "info registers\n");
fprintf (commands, "info frame\n");
fprintf (commands, "info locals\n");
fprintf (commands, "up\n");
}
}
return TRUE;
}
void
mono_runtime_install_handlers (void)
{
#ifndef MONO_CROSS_COMPILE
win32_seh_init();
win32_seh_set_handler(SIGFPE, mono_sigfpe_signal_handler);
win32_seh_set_handler(SIGILL, mono_sigill_signal_handler);
win32_seh_set_handler(SIGSEGV, mono_sigsegv_signal_handler);
if (mini_get_debug_options ()->handle_sigint)
win32_seh_set_handler(SIGINT, mono_sigint_signal_handler);
#endif
}
void
mono_runtime_posix_install_handlers (void)
{
sigset_t signal_set;
sigemptyset (&signal_set);
if (mini_get_debug_options ()->handle_sigint) {
add_signal_handler (SIGINT, mono_sigint_signal_handler, SA_RESTART);
sigaddset (&signal_set, SIGINT);
}
add_signal_handler (SIGFPE, mono_sigfpe_signal_handler, 0);
sigaddset (&signal_set, SIGFPE);
add_signal_handler (SIGQUIT, sigquit_signal_handler, SA_RESTART);
sigaddset (&signal_set, SIGQUIT);
add_signal_handler (SIGILL, mono_sigill_signal_handler, 0);
sigaddset (&signal_set, SIGILL);
add_signal_handler (SIGBUS, mono_sigsegv_signal_handler, 0);
sigaddset (&signal_set, SIGBUS);
if (mono_jit_trace_calls != NULL) {
add_signal_handler (SIGUSR2, sigusr2_signal_handler, SA_RESTART);
sigaddset (&signal_set, SIGUSR2);
}
/* it seems to have become a common bug for some programs that run as parents
* of many processes to block signal delivery for real time signals.
* We try to detect and work around their breakage here.
*/
if (mono_gc_get_suspend_signal () != -1)
sigaddset (&signal_set, mono_gc_get_suspend_signal ());
if (mono_gc_get_restart_signal () != -1)
sigaddset (&signal_set, mono_gc_get_restart_signal ());
sigaddset (&signal_set, SIGCHLD);
signal (SIGPIPE, SIG_IGN);
sigaddset (&signal_set, SIGPIPE);
add_signal_handler (SIGABRT, sigabrt_signal_handler, 0);
sigaddset (&signal_set, SIGABRT);
/* catch SIGSEGV */
add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler, 0);
sigaddset (&signal_set, SIGSEGV);
sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
}
void
mono_runtime_cleanup_handlers (void)
{
if (mini_get_debug_options ()->handle_sigint)
remove_signal_handler (SIGINT);
remove_signal_handler (SIGFPE);
remove_signal_handler (SIGQUIT);
remove_signal_handler (SIGILL);
remove_signal_handler (SIGBUS);
if (mono_jit_trace_calls != NULL)
remove_signal_handler (SIGUSR2);
remove_signal_handler (SIGABRT);
remove_signal_handler (SIGSEGV);
free_saved_signal_handlers ();
}
static void
add_signal_handler (int signo, gpointer handler)
{
struct sigaction sa;
struct sigaction previous_sa;
#ifdef MONO_ARCH_USE_SIGACTION
sa.sa_sigaction = handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
#ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
/*Apple likes to deliver SIGBUS for *0 */
#ifdef __APPLE__
if (signo == SIGSEGV || signo == SIGBUS) {
#else
if (signo == SIGSEGV) {
#endif
sa.sa_flags |= SA_ONSTACK;
/*
* libgc will crash when trying to do stack marking for threads which are on
* an altstack, so delay the suspend signal after the signal handler has
* executed.
*/
if (mono_gc_get_suspend_signal () != -1)
sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
}
#endif
if (signo == SIGSEGV) {
/*
* Delay abort signals while handling SIGSEGVs since they could go unnoticed.
*/
sigset_t block_mask;
sigemptyset (&block_mask);
sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
}
#else
sa.sa_handler = handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
#endif
g_assert (sigaction (signo, &sa, &previous_sa) != -1);
/* if there was already a handler in place for this signal, store it */
if (! (previous_sa.sa_flags & SA_SIGINFO) &&
(SIG_DFL == previous_sa.sa_handler)) {
/* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
} else {
if (mono_do_signal_chaining)
save_old_signal_handler (signo, &previous_sa);
}
}
static void
remove_signal_handler (int signo)
{
struct sigaction sa;
struct sigaction *saved_action = get_saved_signal_handler (signo);
if (!saved_action) {
sa.sa_handler = SIG_DFL;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sigaction (signo, &sa, NULL);
} else {
g_assert (sigaction (signo, saved_action, NULL) != -1);
}
}
void
mono_runtime_posix_install_handlers (void)
{
sigset_t signal_set;
if (mini_get_debug_options ()->handle_sigint)
add_signal_handler (SIGINT, mono_sigint_signal_handler);
add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
add_signal_handler (SIGQUIT, sigquit_signal_handler);
add_signal_handler (SIGILL, mono_sigill_signal_handler);
add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
if (mono_jit_trace_calls != NULL)
add_signal_handler (SIGUSR2, sigusr2_signal_handler);
if (!mono_thread_info_new_interrupt_enabled ())
add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
/* it seems to have become a common bug for some programs that run as parents
* of many processes to block signal delivery for real time signals.
* We try to detect and work around their breakage here.
*/
sigemptyset (&signal_set);
sigaddset (&signal_set, mono_thread_get_abort_signal ());
sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
signal (SIGPIPE, SIG_IGN);
add_signal_handler (SIGABRT, sigabrt_signal_handler);
/* catch SIGSEGV */
add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
}
static void
dump_native_stacktrace (const char *signal, void *ctx)
{
#ifdef HAVE_BACKTRACE_SYMBOLS
void *array [256];
char **names;
int i, size;
mono_runtime_printf_err ("\nNative stacktrace:\n");
size = backtrace (array, 256);
names = backtrace_symbols (array, size);
for (i = 0; i < size; ++i) {
mono_runtime_printf_err ("\t%s", names [i]);
}
g_free (names);
/* Try to get more meaningful information using gdb */
char *debugger_log = mono_debugger_state_str ();
if (debugger_log) {
fprintf (stderr, "\n\tDebugger session state:\n%s\n", debugger_log);
}
#if !defined(HOST_WIN32) && defined(HAVE_SYS_SYSCALL_H) && (defined(SYS_fork) || HAVE_FORK)
if (!mini_get_debug_options ()->no_gdb_backtrace) {
/* From g_spawn_command_line_sync () in eglib */
pid_t pid;
int status;
pid_t crashed_pid = getpid ();
#if defined(TARGET_OSX)
MonoStackHash hashes;
#endif
gchar *output = NULL;
MonoContext mctx;
if (ctx) {
gboolean leave = FALSE;
gboolean dump_for_merp = FALSE;
#if defined(TARGET_OSX)
dump_for_merp = mono_merp_enabled ();
#endif
if (!dump_for_merp) {
#ifdef DISABLE_STRUCTURED_CRASH
leave = TRUE;
#elif defined(TARGET_OSX)
mini_register_sigterm_handler ();
#endif
}
#ifdef TARGET_OSX
if (!leave) {
mono_sigctx_to_monoctx (ctx, &mctx);
// Do before forking
if (!mono_threads_summarize (&mctx, &output, &hashes))
g_assert_not_reached ();
}
// We want our crash, and don't have telemetry
// So we dump to disk
if (!leave && !dump_for_merp)
mono_crash_dump (output);
#endif
}
/*
* glibc fork acquires some locks, so if the crash happened inside malloc/free,
* it will deadlock. Call the syscall directly instead.
*/
#if defined(HOST_ANDROID)
/* SYS_fork is defined to be __NR_fork which is not defined in some ndk versions */
g_assert_not_reached ();
#elif !defined(HOST_DARWIN) && defined(SYS_fork)
pid = (pid_t) syscall (SYS_fork);
#elif HAVE_FORK
pid = (pid_t) fork ();
#else
g_assert_not_reached ();
#endif
#if defined (HAVE_PRCTL) && defined(PR_SET_PTRACER)
if (pid > 0) {
// Allow gdb to attach to the process even if ptrace_scope sysctl variable is set to
// a value other than 0 (the most permissive ptrace scope). Most modern Linux
// distributions set the scope to 1 which allows attaching only to direct children of
// the current process
prctl (PR_SET_PTRACER, pid, 0, 0, 0);
}
#endif
#if defined(TARGET_OSX)
if (mono_merp_enabled ()) {
if (pid == 0) {
if (!ctx) {
mono_runtime_printf_err ("\nMust always pass non-null context when using merp.\n");
exit (1);
}
char *full_version = mono_get_runtime_build_info ();
mono_merp_invoke (crashed_pid, signal, output, &hashes, full_version);
exit (1);
}
}
#endif
if (pid == 0) {
dup2 (STDERR_FILENO, STDOUT_FILENO);
mono_gdb_render_native_backtraces (crashed_pid);
exit (1);
}
mono_runtime_printf_err ("\nDebug info from gdb:\n");
waitpid (pid, &status, 0);
}
#endif
#else
#ifdef HOST_ANDROID
/* set DUMPABLE for this process so debuggerd can attach with ptrace(2), see:
* https://android.googlesource.com/platform/bionic/+/151da681000c07da3c24cd30a3279b1ca017f452/linker/debugger.cpp#206
* this has changed on later versions of Android. Also, we don't want to
* set this on start-up as DUMPABLE has security implications. */
prctl (PR_SET_DUMPABLE, 1);
mono_runtime_printf_err ("\nNo native Android stacktrace (see debuggerd output).\n");
#endif
#endif
}
