void jl_throw_in_thread(int tid, mach_port_t thread, jl_value_t *exception)
{
unsigned int count = MACHINE_THREAD_STATE_COUNT;
x86_thread_state64_t state;
kern_return_t ret = thread_get_state(thread, x86_THREAD_STATE64, (thread_state_t)&state, &count);
HANDLE_MACH_ERROR("thread_get_state", ret);
jl_all_task_states[tid].ptls->bt_size =
rec_backtrace_ctx(jl_all_task_states[tid].ptls->bt_data,
JL_MAX_BT_SIZE, (bt_context_t)&state);
jl_all_task_states[tid].ptls->exception_in_transit = exception;
uint64_t rsp = (uint64_t)jl_all_task_states[tid].signal_stack + sig_stack_size;
rsp &= -16; // ensure 16-byte alignment
// push (null) $RIP onto the stack
rsp -= sizeof(void*);
*(void**)rsp = NULL;
state.__rsp = rsp; // set stack pointer
state.__rip = (uint64_t)&jl_rethrow; // "call" the function
ret = thread_set_state(thread, x86_THREAD_STATE64, (thread_state_t)&state, count);
HANDLE_MACH_ERROR("thread_set_state",ret);
}
size_t rec_backtrace(uintptr_t *data, size_t maxsize)
{
bt_context_t context;
memset(&context, 0, sizeof(context));
jl_unw_get(&context);
return rec_backtrace_ctx(data, maxsize, &context);
}
static void jl_throw_in_ctx(jl_ptls_t ptls, jl_value_t *e, void *sigctx)
{
if (!ptls->safe_restore)
ptls->bt_size = rec_backtrace_ctx(ptls->bt_data, JL_MAX_BT_SIZE,
jl_to_bt_context(sigctx));
ptls->exception_in_transit = e;
jl_call_in_ctx(ptls, &jl_rethrow, sigctx);
}
static void JL_NORETURN jl_throw_in_ctx(jl_value_t *e, void *sigctx)
{
if (!jl_safe_restore)
jl_bt_size = rec_backtrace_ctx(jl_bt_data, JL_MAX_BT_SIZE,
jl_to_bt_context(sigctx));
jl_exception_in_transit = e;
// TODO throw the error by modifying sigctx for supported platforms
// This will avoid running the atexit handler on the signal stack
// if no excepiton handler is registered.
jl_rethrow();
}
// what to do on a critical error
static void jl_critical_error(int sig, bt_context_t context, ptrint_t *bt_data, size_t *bt_size)
{
size_t n = *bt_size;
if (sig)
jl_safe_printf("\nsignal (%d): %s\n", sig, strsignal(sig));
jl_safe_printf("while loading %s, in expression starting on line %d\n", jl_filename, jl_lineno);
if (context)
*bt_size = n = rec_backtrace_ctx(bt_data, JL_MAX_BT_SIZE, context);
for(size_t i=0; i < n; i++)
gdblookup(bt_data[i]);
gc_debug_print_status();
}
void sigdie_handler(int sig, siginfo_t *info, void *context)
{
if (sig != SIGINFO) {
sigset_t sset;
uv_tty_reset_mode();
sigfillset(&sset);
sigprocmask(SIG_UNBLOCK, &sset, NULL);
signal(sig, SIG_DFL);
}
jl_safe_printf("\nsignal (%d): %s\n", sig, strsignal(sig));
#ifdef __APPLE__
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, (bt_context_t)&((ucontext64_t*)context)->uc_mcontext64->__ss);
#else
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, (ucontext_t*)context);
#endif
jlbacktrace();
if (sig != SIGSEGV &&
sig != SIGBUS &&
sig != SIGILL &&
sig != SIGINFO) {
raise(sig);
}
}
// what to do on a critical error
static void jl_critical_error(int sig, bt_context_t context, ptrint_t *bt_data, size_t *bt_size)
{
// This function is not allowed to reference any TLS variables.
// We need to explicitly pass in the TLS buffer pointer when
// we make `jl_filename` and `jl_lineno` thread local.
size_t n = *bt_size;
if (sig)
jl_safe_printf("\nsignal (%d): %s\n", sig, strsignal(sig));
jl_safe_printf("while loading %s, in expression starting on line %d\n", jl_filename, jl_lineno);
if (context)
*bt_size = n = rec_backtrace_ctx(bt_data, JL_MAX_BT_SIZE, context);
for(size_t i=0; i < n; i++)
jl_gdblookup(bt_data[i]);
gc_debug_print_status();
}
void jl_throw_in_ctx(jl_value_t* excpt, CONTEXT *ctxThread, int bt)
{
bt_size = bt ? rec_backtrace_ctx(bt_data, MAX_BT_SIZE, ctxThread) : 0;
jl_exception_in_transit = excpt;
#if defined(_CPU_X86_64_)
ctxThread->Rip = (DWORD64)&jl_rethrow;
ctxThread->Rsp &= (DWORD64)-16;
ctxThread->Rsp -= 8; //fix up the stack pointer -- this seems to be correct by observation
#elif defined(_CPU_X86_)
ctxThread->Eip = (DWORD)&jl_rethrow;
ctxThread->Esp &= (DWORD)-16;
ctxThread->Esp -= 4; //fix up the stack pointer
#else
#error WIN16 not supported :P
#endif
}
static DWORD WINAPI profile_bt( LPVOID lparam )
{
// Note: illegal to use jl_* functions from this thread
TIMECAPS tc;
if (MMSYSERR_NOERROR!=timeGetDevCaps(&tc, sizeof(tc))) {
fputs("failed to get timer resolution",stderr);
hBtThread = 0;
return 0;
}
while (1) {
if (running && bt_size_cur < bt_size_max) {
DWORD timeout = nsecprof/GIGA;
timeout = min(max(timeout,tc.wPeriodMin*2),tc.wPeriodMax/2);
Sleep(timeout);
if ((DWORD)-1 == SuspendThread(hMainThread)) {
fputs("failed to suspend main thread. aborting profiling.",stderr);
break;
}
CONTEXT ctxThread;
memset(&ctxThread, 0, sizeof(CONTEXT));
ctxThread.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER;
if (!GetThreadContext(hMainThread, &ctxThread)) {
fputs("failed to get context from main thread. aborting profiling.",stderr);
break;
}
// Get backtrace data
bt_size_cur += rec_backtrace_ctx((uintptr_t*)bt_data_prof + bt_size_cur,
bt_size_max - bt_size_cur - 1, &ctxThread);
// Mark the end of this block with 0
bt_data_prof[bt_size_cur] = 0;
bt_size_cur++;
if ((DWORD)-1 == ResumeThread(hMainThread)) {
fputs("failed to resume main thread! aborting.",stderr);
gc_debug_critical_error();
abort();
}
}
else {
SuspendThread(GetCurrentThread());
}
}
hBtThread = 0;
return 0;
}
void jl_throw_in_ctx(jl_value_t *excpt, CONTEXT *ctxThread, int bt)
{
assert(excpt != NULL);
#if defined(_CPU_X86_64_)
DWORD64 Rsp = (ctxThread->Rsp&(DWORD64)-16) - 8;
#elif defined(_CPU_X86_)
DWORD32 Esp = (ctxThread->Esp&(DWORD32)-16) - 4;
#else
#error WIN16 not supported :P
#endif
bt_size = bt ? rec_backtrace_ctx(bt_data, MAX_BT_SIZE, ctxThread) : 0;
jl_exception_in_transit = excpt;
#if defined(_CPU_X86_64_)
*(DWORD64*)Rsp = 0;
ctxThread->Rsp = Rsp;
ctxThread->Rip = (DWORD64)&jl_rethrow;
#elif defined(_CPU_X86_)
*(DWORD32*)Esp = 0;
ctxThread->Esp = Esp;
ctxThread->Eip = (DWORD)&jl_rethrow;
#endif
}
static void *signal_listener(void *arg)
{
static uintptr_t bt_data[JL_MAX_BT_SIZE + 1];
static size_t bt_size = 0;
sigset_t sset;
unw_context_t *signal_context;
int sig, critical, profile;
int i;
jl_sigsetset(&sset);
while (1) {
profile = 0;
sigwait(&sset, &sig);
#ifndef HAVE_MACH
# ifdef HAVE_ITIMER
profile = (sig == SIGPROF);
# else
profile = (sig == SIGUSR1);
# endif
#endif
if (sig == SIGINT) {
if (exit_on_sigint) {
critical = 1;
}
else {
jl_try_deliver_sigint();
continue;
}
}
else {
critical = 0;
}
critical |= (sig == SIGTERM);
critical |= (sig == SIGABRT);
critical |= (sig == SIGQUIT);
#ifdef SIGINFO
critical |= (sig == SIGINFO);
#else
critical |= (sig == SIGUSR1 && !profile);
#endif
bt_size = 0;
// sample each thread, round-robin style in reverse order
// (so that thread zero gets notified last)
for (i = jl_n_threads; i-- > 0; ) {
// notify thread to stop
jl_thread_suspend_and_get_state(i, &signal_context);
// do backtrace on thread contexts for critical signals
// this part must be signal-handler safe
if (critical) {
bt_size += rec_backtrace_ctx(bt_data + bt_size,
JL_MAX_BT_SIZE / jl_n_threads - 1,
signal_context);
bt_data[bt_size++] = 0;
}
// do backtrace for profiler
if (profile && running) {
if (bt_size_cur < bt_size_max - 1) {
// Get backtrace data
bt_size_cur += rec_backtrace_ctx((uintptr_t*)bt_data_prof + bt_size_cur,
bt_size_max - bt_size_cur - 1, signal_context);
// Mark the end of this block with 0
bt_data_prof[bt_size_cur++] = 0;
}
if (bt_size_cur >= bt_size_max - 1) {
// Buffer full: Delete the timer
jl_profile_stop_timer();
}
}
// notify thread to resume
jl_thread_resume(i, sig);
}
// this part is async with the running of the rest of the program
// and must be thread-safe, but not necessarily signal-handler safe
if (critical) {
jl_critical_error(sig, NULL, bt_data, &bt_size);
// FIXME
// It is unsafe to run the exit handler on this thread
// (this thread is not managed and has a rather limited stack space)
// try harder to run this on a managed thread.
#ifdef SIGINFO
if (sig != SIGINFO)
#else
if (sig != SIGUSR1)
#endif
jl_exit(128 + sig);
}
}
}
void *mach_profile_listener(void *arg)
{
(void)arg;
int max_size = 512;
mach_profiler_thread = mach_thread_self();
mig_reply_error_t *bufRequest = (mig_reply_error_t *) malloc(max_size);
while (1) {
kern_return_t ret = mach_msg(&bufRequest->Head, MACH_RCV_MSG,
0, max_size, profile_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
HANDLE_MACH_ERROR("mach_msg",ret);
if (bt_size_cur < bt_size_max) {
kern_return_t ret;
// Suspend the thread so we may safely sample it
ret = thread_suspend(main_thread);
HANDLE_MACH_ERROR("thread_suspend",ret);
// Do the actual sampling
unsigned int count = MACHINE_THREAD_STATE_COUNT;
x86_thread_state64_t state;
// Get the state of the suspended thread
ret = thread_get_state(main_thread,x86_THREAD_STATE64,(thread_state_t)&state,&count);
HANDLE_MACH_ERROR("thread_get_state",ret);
// Initialize the unwind context with the suspend thread's state
unw_context_t uc;
memset(&uc,0,sizeof(unw_context_t));
memcpy(&uc,&state,sizeof(x86_thread_state64_t));
/*
* Unfortunately compact unwind info is incorrectly generated for quite a number of
* libraries by quite a large number of compilers. We can fall back to DWARF unwind info
* in some cases, but in quite a number of cases (especially libraries not compiled in debug
* mode, only the compact unwind info may be available). Even more unfortunately, there is no
* way to detect such bogus compact unwind info (other than noticing the resulting segfault).
* What we do here is ugly, but necessary until the compact unwind info situation improves.
* We try to use the compact unwind info and if that results in a segfault, we retry with DWARF info.
* Note that in a small number of cases this may result in bogus stack traces, but at least the topmost
* entry will always be correct, and the number of cases in which this is an issue is rather small.
* Other than that, this implementation is not incorrect as the other thread is paused while we are profiling
* and during stack unwinding we only ever read memory, but never write it.
*/
forceDwarf = 0;
unw_getcontext(&profiler_uc);
if (forceDwarf == 0) {
// Save the backtrace
bt_size_cur += rec_backtrace_ctx((ptrint_t*)bt_data_prof+bt_size_cur, bt_size_max-bt_size_cur-1, &uc);
}
else if (forceDwarf == 1) {
bt_size_cur += rec_backtrace_ctx_dwarf((ptrint_t*)bt_data_prof+bt_size_cur, bt_size_max-bt_size_cur-1, &uc);
}
else if (forceDwarf == -1) {
JL_PRINTF(JL_STDERR, "Warning: Profiler attempt to access an invalid memory location\n");
}
forceDwarf = -2;
// Mark the end of this block with 0
bt_data_prof[bt_size_cur] = 0;
bt_size_cur++;
// We're done! Resume the thread.
ret = thread_resume(main_thread);
HANDLE_MACH_ERROR("thread_resume",ret)
if (running) {
// Reset the alarm
ret = clock_alarm(clk, TIME_RELATIVE, timerprof, profile_port);
HANDLE_MACH_ERROR("clock_alarm",ret)
}
}
}
static LONG WINAPI exception_handler(struct _EXCEPTION_POINTERS *ExceptionInfo) {
if (ExceptionInfo->ExceptionRecord->ExceptionFlags == 0) {
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_STACK_OVERFLOW:
#if defined(_CPU_X86_64_)
ExceptionInfo->ContextRecord->Rip = (DWORD64)&win_raise_exception;
ExceptionInfo->ContextRecord->Rcx = (DWORD64)jl_stackovf_exception;
ExceptionInfo->ContextRecord->Rsp &= (DWORD64)-16;
ExceptionInfo->ContextRecord->Rsp -= 8; //fix up the stack pointer -- this seems to be correct by observation
#elif defined(_CPU_X86_)
ExceptionInfo->ContextRecord->Eip = (DWORD)&win_raise_exception;
ExceptionInfo->ContextRecord->Ecx = (DWORD)jl_stackovf_exception;
ExceptionInfo->ContextRecord->Esp &= (DWORD)-16;
ExceptionInfo->ContextRecord->Esp -= 4; //fix up the stack pointer
#else
#error WIN16 not supported :P
#endif
return EXCEPTION_CONTINUE_EXECUTION;
default:
ios_puts("Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.\nException: ", ios_stderr);
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_ACCESS_VIOLATION:
ios_puts("EXCEPTION_ACCESS_VIOLATION", ios_stderr); break;
case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
ios_puts("EXCEPTION_ARRAY_BOUNDS_EXCEEDED", ios_stderr); break;
case EXCEPTION_BREAKPOINT:
ios_puts("EXCEPTION_BREAKPOINT", ios_stderr); break;
case EXCEPTION_DATATYPE_MISALIGNMENT:
ios_puts("EXCEPTION_DATATYPE_MISALIGNMENT", ios_stderr); break;
case EXCEPTION_FLT_DENORMAL_OPERAND:
ios_puts("EXCEPTION_FLT_DENORMAL_OPERAND", ios_stderr); break;
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
ios_puts("EXCEPTION_FLT_DIVIDE_BY_ZERO", ios_stderr); break;
case EXCEPTION_FLT_INEXACT_RESULT:
ios_puts("EXCEPTION_FLT_INEXACT_RESULT", ios_stderr); break;
case EXCEPTION_FLT_INVALID_OPERATION:
ios_puts("EXCEPTION_FLT_INVALID_OPERATION", ios_stderr); break;
case EXCEPTION_FLT_OVERFLOW:
ios_puts("EXCEPTION_FLT_OVERFLOW", ios_stderr); break;
case EXCEPTION_FLT_STACK_CHECK:
ios_puts("EXCEPTION_FLT_STACK_CHECK", ios_stderr); break;
case EXCEPTION_FLT_UNDERFLOW:
ios_puts("EXCEPTION_FLT_UNDERFLOW", ios_stderr); break;
case EXCEPTION_ILLEGAL_INSTRUCTION:
ios_puts("EXCEPTION_ILLEGAL_INSTRUCTION", ios_stderr); break;
case EXCEPTION_IN_PAGE_ERROR:
ios_puts("EXCEPTION_IN_PAGE_ERROR", ios_stderr); break;
case EXCEPTION_INT_DIVIDE_BY_ZERO:
ios_puts("EXCEPTION_INT_DIVIDE_BY_ZERO", ios_stderr); break;
case EXCEPTION_INT_OVERFLOW:
ios_puts("EXCEPTION_INT_OVERFLOW", ios_stderr); break;
case EXCEPTION_INVALID_DISPOSITION:
ios_puts("EXCEPTION_INVALID_DISPOSITION", ios_stderr); break;
case EXCEPTION_NONCONTINUABLE_EXCEPTION:
ios_puts("EXCEPTION_NONCONTINUABLE_EXCEPTION", ios_stderr); break;
case EXCEPTION_PRIV_INSTRUCTION:
ios_puts("EXCEPTION_PRIV_INSTRUCTION", ios_stderr); break;
case EXCEPTION_SINGLE_STEP:
ios_puts("EXCEPTION_SINGLE_STEP", ios_stderr); break;
case EXCEPTION_STACK_OVERFLOW:
ios_puts("EXCEPTION_STACK_OVERFLOW", ios_stderr); break;
default:
ios_puts("UNKNOWN", ios_stderr); break;
}
ios_printf(ios_stderr," at 0x%Ix -- ", (size_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
gdblookup((ptrint_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, ExceptionInfo->ContextRecord);
jlbacktrace();
break;
}
}
return EXCEPTION_CONTINUE_SEARCH;
}
static LONG WINAPI exception_handler(struct _EXCEPTION_POINTERS *ExceptionInfo)
{
if (ExceptionInfo->ExceptionRecord->ExceptionFlags == 0) {
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_STACK_OVERFLOW:
jl_throw_in_ctx(jl_stackovf_exception, ExceptionInfo->ContextRecord, 0);
return EXCEPTION_CONTINUE_EXECUTION;
default:
ios_puts("Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.\nException: ", ios_stderr);
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_ACCESS_VIOLATION:
ios_puts("EXCEPTION_ACCESS_VIOLATION", ios_stderr); break;
case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
ios_puts("EXCEPTION_ARRAY_BOUNDS_EXCEEDED", ios_stderr); break;
case EXCEPTION_BREAKPOINT:
ios_puts("EXCEPTION_BREAKPOINT", ios_stderr); break;
case EXCEPTION_DATATYPE_MISALIGNMENT:
ios_puts("EXCEPTION_DATATYPE_MISALIGNMENT", ios_stderr); break;
case EXCEPTION_FLT_DENORMAL_OPERAND:
ios_puts("EXCEPTION_FLT_DENORMAL_OPERAND", ios_stderr); break;
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
ios_puts("EXCEPTION_FLT_DIVIDE_BY_ZERO", ios_stderr); break;
case EXCEPTION_FLT_INEXACT_RESULT:
ios_puts("EXCEPTION_FLT_INEXACT_RESULT", ios_stderr); break;
case EXCEPTION_FLT_INVALID_OPERATION:
ios_puts("EXCEPTION_FLT_INVALID_OPERATION", ios_stderr); break;
case EXCEPTION_FLT_OVERFLOW:
ios_puts("EXCEPTION_FLT_OVERFLOW", ios_stderr); break;
case EXCEPTION_FLT_STACK_CHECK:
ios_puts("EXCEPTION_FLT_STACK_CHECK", ios_stderr); break;
case EXCEPTION_FLT_UNDERFLOW:
ios_puts("EXCEPTION_FLT_UNDERFLOW", ios_stderr); break;
case EXCEPTION_ILLEGAL_INSTRUCTION:
ios_puts("EXCEPTION_ILLEGAL_INSTRUCTION", ios_stderr); break;
case EXCEPTION_IN_PAGE_ERROR:
ios_puts("EXCEPTION_IN_PAGE_ERROR", ios_stderr); break;
case EXCEPTION_INT_DIVIDE_BY_ZERO:
ios_puts("EXCEPTION_INT_DIVIDE_BY_ZERO", ios_stderr); break;
case EXCEPTION_INT_OVERFLOW:
ios_puts("EXCEPTION_INT_OVERFLOW", ios_stderr); break;
case EXCEPTION_INVALID_DISPOSITION:
ios_puts("EXCEPTION_INVALID_DISPOSITION", ios_stderr); break;
case EXCEPTION_NONCONTINUABLE_EXCEPTION:
ios_puts("EXCEPTION_NONCONTINUABLE_EXCEPTION", ios_stderr); break;
case EXCEPTION_PRIV_INSTRUCTION:
ios_puts("EXCEPTION_PRIV_INSTRUCTION", ios_stderr); break;
case EXCEPTION_SINGLE_STEP:
ios_puts("EXCEPTION_SINGLE_STEP", ios_stderr); break;
case EXCEPTION_STACK_OVERFLOW:
ios_puts("EXCEPTION_STACK_OVERFLOW", ios_stderr); break;
default:
ios_puts("UNKNOWN", ios_stderr); break;
}
ios_printf(ios_stderr," at 0x%Ix -- ", (size_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
gdblookup((ptrint_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, ExceptionInfo->ContextRecord);
jlbacktrace();
break;
}
}
return EXCEPTION_CONTINUE_SEARCH;
}
static void *signal_listener(void *arg)
{
static intptr_t bt_data[JL_MAX_BT_SIZE + 1];
static size_t bt_size = 0;
sigset_t sset;
unw_context_t *signal_context;
int sig, critical, profile;
int i;
jl_sigsetset(&sset);
#ifdef HAVE_SIGTIMEDWAIT
siginfo_t info;
sigaddset(&sset, SIGUSR2);
sigprocmask(SIG_SETMASK, &sset, 0);
#endif
while (1) {
profile = 0;
#ifdef HAVE_SIGTIMEDWAIT
if (running) {
sig = sigtimedwait(&sset, &info, &timeoutprof);
}
else {
sig = sigwaitinfo(&sset, &info);
}
if (sig == -1) {
int err = errno;
if (err == EAGAIN) {
// this was a timeout event
profile = 1;
}
else {
assert(err == EINTR);
continue;
}
}
else if (sig == SIGUSR2) {
// notification to toggle profiler
running = !running;
continue;
}
#else
sigwait(&sset, &sig);
#ifndef HAVE_MACH
#ifdef HAVE_ITIMER
profile = (sig == SIGPROF);
#else
profile = (sig == SIGUSR1);
#endif
#endif
#endif
critical = (sig == SIGINT && exit_on_sigint);
critical |= (sig == SIGTERM);
critical |= (sig == SIGABRT);
critical |= (sig == SIGQUIT);
#ifdef SIGINFO
critical |= (sig == SIGINFO);
#else
critical |= (sig == SIGUSR1 && !profile);
#endif
bt_size = 0;
// sample each thread, round-robin style in reverse order
// (so that thread zero gets notified last)
for (i = jl_n_threads; i-- > 0; ) {
// notify thread to stop
jl_thread_suspend_and_get_state(i, &signal_context, sig);
// do backtrace on thread contexts for critical signals
// this part must be signal-handler safe
if (critical) {
bt_size += rec_backtrace_ctx(bt_data + bt_size,
JL_MAX_BT_SIZE / jl_n_threads - 1,
signal_context);
bt_data[bt_size++] = 0;
}
// do backtrace for profiler
if (profile && running) {
if (bt_size_cur < bt_size_max - 1) {
// Get backtrace data
bt_size_cur += rec_backtrace_ctx((ptrint_t*)bt_data_prof + bt_size_cur,
bt_size_max - bt_size_cur - 1, signal_context);
// Mark the end of this block with 0
bt_data_prof[bt_size_cur++] = 0;
}
if (bt_size_cur >= bt_size_max - 1) {
// Buffer full: Delete the timer
jl_profile_stop_timer();
}
}
// notify thread to resume
jl_thread_resume(i, sig);
}
// this part is async with the running of the rest of the program
// and must be thread-safe, but not necessarily signal-handler safe
if (critical) {
jl_critical_error(sig, NULL, bt_data, &bt_size);
#ifdef SIGINFO
if (sig != SIGINFO)
#else
if (sig != SIGUSR1)
#endif
jl_exit(128 + sig);
}
}
}
void *mach_profile_listener(void *arg)
{
(void)arg;
int i;
const int max_size = 512;
attach_exception_port();
#ifdef LIBOSXUNWIND
mach_profiler_thread = mach_thread_self();
#endif
mig_reply_error_t *bufRequest = (mig_reply_error_t *) malloc(max_size);
while (1) {
kern_return_t ret = mach_msg(&bufRequest->Head, MACH_RCV_MSG,
0, max_size, profile_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
HANDLE_MACH_ERROR("mach_msg", ret);
// sample each thread, round-robin style in reverse order
// (so that thread zero gets notified last)
for (i = jl_n_threads; i-- > 0; ) {
// if there is no space left, break early
if (bt_size_cur >= bt_size_max - 1)
break;
unw_context_t *uc;
jl_thread_suspend_and_get_state(i, &uc, -1);
#ifdef LIBOSXUNWIND
/*
* Unfortunately compact unwind info is incorrectly generated for quite a number of
* libraries by quite a large number of compilers. We can fall back to DWARF unwind info
* in some cases, but in quite a number of cases (especially libraries not compiled in debug
* mode, only the compact unwind info may be available). Even more unfortunately, there is no
* way to detect such bogus compact unwind info (other than noticing the resulting segfault).
* What we do here is ugly, but necessary until the compact unwind info situation improves.
* We try to use the compact unwind info and if that results in a segfault, we retry with DWARF info.
* Note that in a small number of cases this may result in bogus stack traces, but at least the topmost
* entry will always be correct, and the number of cases in which this is an issue is rather small.
* Other than that, this implementation is not incorrect as the other thread is paused while we are profiling
* and during stack unwinding we only ever read memory, but never write it.
*/
forceDwarf = 0;
unw_getcontext(&profiler_uc); // will resume from this point if the next lines segfault at any point
if (forceDwarf == 0) {
// Save the backtrace
bt_size_cur += rec_backtrace_ctx((ptrint_t*)bt_data_prof + bt_size_cur, bt_size_max - bt_size_cur - 1, uc);
}
else if (forceDwarf == 1) {
bt_size_cur += rec_backtrace_ctx_dwarf((ptrint_t*)bt_data_prof + bt_size_cur, bt_size_max - bt_size_cur - 1, uc);
}
else if (forceDwarf == -1) {
jl_safe_printf("WARNING: profiler attempt to access an invalid memory location\n");
}
forceDwarf = -2;
#else
bt_size_cur += rec_backtrace_ctx((ptrint_t*)bt_data_prof + bt_size_cur, bt_size_max - bt_size_cur - 1, uc);
#endif
// Mark the end of this block with 0
bt_data_prof[bt_size_cur++] = 0;
// We're done! Resume the thread.
jl_thread_resume(i, 0);
if (running) {
// Reset the alarm
kern_return_t ret = clock_alarm(clk, TIME_RELATIVE, timerprof, profile_port);
HANDLE_MACH_ERROR("clock_alarm", ret)
}
}
}
}
//exc_server uses dlsym to find symbol
DLLEXPORT
kern_return_t catch_exception_raise(mach_port_t exception_port,
mach_port_t thread,
mach_port_t task,
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t code_count)
{
unsigned int count = MACHINE_THREAD_STATE_COUNT;
unsigned int exc_count = X86_EXCEPTION_STATE64_COUNT;
x86_thread_state64_t state, old_state;
x86_exception_state64_t exc_state;
kern_return_t ret;
//memset(&state,0,sizeof(x86_thread_state64_t));
//memset(&exc_state,0,sizeof(x86_exception_state64_t));
#ifdef LIBOSXUNWIND
if (thread == mach_profiler_thread) {
return profiler_segv_handler(exception_port,thread,task,exception,code,code_count);
}
#endif
ret = thread_get_state(thread,x86_EXCEPTION_STATE64,(thread_state_t)&exc_state,&exc_count);
HANDLE_MACH_ERROR("thread_get_state(1)",ret);
uint64_t fault_addr = exc_state.__faultvaddr;
#ifdef SEGV_EXCEPTION
if (1) {
#else
if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) == 0) { // check if this was a valid address
#endif
ret = thread_get_state(thread,x86_THREAD_STATE64,(thread_state_t)&state,&count);
HANDLE_MACH_ERROR("thread_get_state(2)",ret);
old_state = state;
// memset(&state,0,sizeof(x86_thread_state64_t));
// Setup libunwind information
state.__rsp = (uint64_t)signal_stack + sig_stack_size;
state.__rsp -= sizeof(unw_context_t);
state.__rsp &= -16;
unw_context_t *uc = (unw_context_t*)state.__rsp;
state.__rsp -= 512;
// This is for alignment. In particular note that the sizeof(void*) is necessary
// since it would usually specify the return address (i.e., we are aligning the call
// frame to a 16 byte boundary as required by the abi, but the stack pointer
// to point to the byte beyond that. Not doing this leads to funny behavior on
// the first access to an external function will fail due to stack misalignment
state.__rsp &= -16;
state.__rsp -= sizeof(void*);
memset(uc,0,sizeof(unw_context_t));
memcpy(uc,&old_state,sizeof(x86_thread_state64_t));
state.__rdi = (uint64_t)uc;
if (is_addr_on_stack((void*)fault_addr)) {
state.__rip = (uint64_t)darwin_stack_overflow_handler;
}
#ifdef SEGV_EXCEPTION
else if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) != 0) {
// no page mapped at this address
state.__rip = (uint64_t)darwin_segv_handler;
}
#endif
else {
if (!(exc_state.__err & WRITE_FAULT))
return KERN_INVALID_ARGUMENT; // rethrow the SEGV since it wasn't an error with writing to read-only memory
state.__rip = (uint64_t)darwin_accerr_handler;
}
state.__rbp = state.__rsp;
ret = thread_set_state(thread,x86_THREAD_STATE64,(thread_state_t)&state,count);
HANDLE_MACH_ERROR("thread_set_state",ret);
return KERN_SUCCESS;
}
else {
ret = thread_get_state(thread,x86_THREAD_STATE64,(thread_state_t)&state,&count);
HANDLE_MACH_ERROR("thread_get_state(3)",ret);
jl_safe_printf("\nsignal (%d): %s\n", SIGSEGV, strsignal(SIGSEGV));
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, (unw_context_t*)&state);
jlbacktrace();
return KERN_INVALID_ARGUMENT;
}
}
void attach_exception_port()
{
kern_return_t ret;
// http://www.opensource.apple.com/source/xnu/xnu-2782.1.97/osfmk/man/thread_set_exception_ports.html
ret = thread_set_exception_ports(mach_thread_self(),EXC_MASK_BAD_ACCESS,segv_port,EXCEPTION_DEFAULT,MACHINE_THREAD_STATE);
HANDLE_MACH_ERROR("thread_set_exception_ports",ret);
}
void darwin_accerr_handler(unw_context_t *uc)
{
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, uc);
jl_exception_in_transit = jl_readonlymemory_exception;
jl_rethrow();
}
void darwin_stack_overflow_handler(unw_context_t *uc)
{
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, uc);
jl_exception_in_transit = jl_stackovf_exception;
jl_rethrow();
}
static LONG WINAPI _exception_handler(struct _EXCEPTION_POINTERS *ExceptionInfo, int in_ctx)
{
if (ExceptionInfo->ExceptionRecord->ExceptionFlags == 0) {
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_INT_DIVIDE_BY_ZERO:
fpreset();
jl_throw_in_ctx(jl_diverror_exception, ExceptionInfo->ContextRecord,in_ctx);
return EXCEPTION_CONTINUE_EXECUTION;
case EXCEPTION_STACK_OVERFLOW:
jl_throw_in_ctx(jl_stackovf_exception, ExceptionInfo->ContextRecord,in_ctx&&pSetThreadStackGuarantee);
return EXCEPTION_CONTINUE_EXECUTION;
}
jl_safe_printf("\nPlease submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.\nException: ");
switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
case EXCEPTION_ACCESS_VIOLATION:
jl_safe_printf("EXCEPTION_ACCESS_VIOLATION"); break;
case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
jl_safe_printf("EXCEPTION_ARRAY_BOUNDS_EXCEEDED"); break;
case EXCEPTION_BREAKPOINT:
jl_safe_printf("EXCEPTION_BREAKPOINT"); break;
case EXCEPTION_DATATYPE_MISALIGNMENT:
jl_safe_printf("EXCEPTION_DATATYPE_MISALIGNMENT"); break;
case EXCEPTION_FLT_DENORMAL_OPERAND:
jl_safe_printf("EXCEPTION_FLT_DENORMAL_OPERAND"); break;
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
jl_safe_printf("EXCEPTION_FLT_DIVIDE_BY_ZERO"); break;
case EXCEPTION_FLT_INEXACT_RESULT:
jl_safe_printf("EXCEPTION_FLT_INEXACT_RESULT"); break;
case EXCEPTION_FLT_INVALID_OPERATION:
jl_safe_printf("EXCEPTION_FLT_INVALID_OPERATION"); break;
case EXCEPTION_FLT_OVERFLOW:
jl_safe_printf("EXCEPTION_FLT_OVERFLOW"); break;
case EXCEPTION_FLT_STACK_CHECK:
jl_safe_printf("EXCEPTION_FLT_STACK_CHECK"); break;
case EXCEPTION_FLT_UNDERFLOW:
jl_safe_printf("EXCEPTION_FLT_UNDERFLOW"); break;
case EXCEPTION_ILLEGAL_INSTRUCTION:
jl_safe_printf("EXCEPTION_ILLEGAL_INSTRUCTION"); break;
case EXCEPTION_IN_PAGE_ERROR:
jl_safe_printf("EXCEPTION_IN_PAGE_ERROR"); break;
case EXCEPTION_INT_DIVIDE_BY_ZERO:
jl_safe_printf("EXCEPTION_INT_DIVIDE_BY_ZERO"); break;
case EXCEPTION_INT_OVERFLOW:
jl_safe_printf("EXCEPTION_INT_OVERFLOW"); break;
case EXCEPTION_INVALID_DISPOSITION:
jl_safe_printf("EXCEPTION_INVALID_DISPOSITION"); break;
case EXCEPTION_NONCONTINUABLE_EXCEPTION:
jl_safe_printf("EXCEPTION_NONCONTINUABLE_EXCEPTION"); break;
case EXCEPTION_PRIV_INSTRUCTION:
jl_safe_printf("EXCEPTION_PRIV_INSTRUCTION"); break;
case EXCEPTION_SINGLE_STEP:
jl_safe_printf("EXCEPTION_SINGLE_STEP"); break;
case EXCEPTION_STACK_OVERFLOW:
jl_safe_printf("EXCEPTION_STACK_OVERFLOW"); break;
default:
jl_safe_printf("UNKNOWN"); break;
}
jl_safe_printf(" at 0x%Ix -- ", (size_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
gdblookup((ptrint_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
bt_size = rec_backtrace_ctx(bt_data, MAX_BT_SIZE, ExceptionInfo->ContextRecord);
jlbacktrace();
static int recursion = 0;
if (recursion++)
exit(1);
else
jl_exit(1);
}
return EXCEPTION_CONTINUE_SEARCH;
}
static void *signal_listener(void *arg)
{
static uintptr_t bt_data[JL_MAX_BT_SIZE + 1];
static size_t bt_size = 0;
sigset_t sset;
int sig, critical, profile;
jl_sigsetset(&sset);
#ifdef HAVE_KEVENT
struct kevent ev;
int sigqueue = kqueue();
if (sigqueue == -1) {
perror("signal kqueue");
}
else {
kqueue_signal(&sigqueue, &ev, SIGINT);
kqueue_signal(&sigqueue, &ev, SIGTERM);
kqueue_signal(&sigqueue, &ev, SIGABRT);
kqueue_signal(&sigqueue, &ev, SIGQUIT);
#ifdef SIGINFO
kqueue_signal(&sigqueue, &ev, SIGINFO);
#else
kqueue_signal(&sigqueue, &ev, SIGUSR1);
#endif
#ifdef HAVE_ITIMER
kqueue_signal(&sigqueue, &ev, SIGPROF);
#endif
}
#endif
while (1) {
profile = 0;
sig = 0;
errno = 0;
#ifdef HAVE_KEVENT
if (sigqueue != -1) {
int nevents = kevent(sigqueue, NULL, 0, &ev, 1, NULL);
if (nevents == -1) {
if (errno == EINTR)
continue;
perror("signal kevent");
}
if (nevents != 1) {
close(sigqueue);
sigqueue = -1;
continue;
}
sig = ev.ident;
}
else
#endif
if (sigwait(&sset, &sig)) {
sig = SIGABRT; // this branch can't occur, unless we had stack memory corruption of sset
}
else if (!sig || errno == EINTR) {
// This should never happen, but it has been observed to occur
// when this thread gets used to handle run a signal handler (without SA_RESTART).
// It would be nice to prohibit the kernel from doing that, by blocking signals on this thread,
// (so that we aren't temporarily unable to handle the signals that this thread exists to handle)
// but that sometimes results in the signals never getting delivered at all.
// Apparently the only consistent way to handle signals with sigwait is all-or-nothing :(
// And while sigwait handles per-process signals more sanely,
// it can't really handle thread-targeted signals at all.
// So signals really do seem to always just be lose-lose.
continue;
}
#ifndef HAVE_MACH
# ifdef HAVE_ITIMER
profile = (sig == SIGPROF);
# else
profile = (sig == SIGUSR1);
# endif
#endif
if (sig == SIGINT) {
if (jl_ignore_sigint()) {
continue;
}
else if (exit_on_sigint) {
critical = 1;
}
else {
jl_try_deliver_sigint();
continue;
}
}
else {
critical = 0;
}
critical |= (sig == SIGTERM);
critical |= (sig == SIGABRT);
critical |= (sig == SIGQUIT);
#ifdef SIGINFO
critical |= (sig == SIGINFO);
#else
critical |= (sig == SIGUSR1 && !profile);
#endif
int doexit = critical;
#ifdef SIGINFO
if (sig == SIGINFO)
doexit = 0;
#else
if (sig == SIGUSR1)
doexit = 0;
#endif
bt_size = 0;
#if !defined(JL_DISABLE_LIBUNWIND)
unw_context_t *signal_context;
// sample each thread, round-robin style in reverse order
// (so that thread zero gets notified last)
for (int i = jl_n_threads; i-- > 0; ) {
// notify thread to stop
jl_thread_suspend_and_get_state(i, &signal_context);
// do backtrace on thread contexts for critical signals
// this part must be signal-handler safe
if (critical) {
bt_size += rec_backtrace_ctx(bt_data + bt_size,
JL_MAX_BT_SIZE / jl_n_threads - 1,
signal_context);
bt_data[bt_size++] = 0;
}
// do backtrace for profiler
if (profile && running) {
if (bt_size_cur < bt_size_max - 1) {
// unwinding can fail, so keep track of the current state
// and restore from the SEGV handler if anything happens.
jl_ptls_t ptls = jl_get_ptls_states();
jl_jmp_buf *old_buf = ptls->safe_restore;
jl_jmp_buf buf;
ptls->safe_restore = &buf;
if (jl_setjmp(buf, 0)) {
jl_safe_printf("WARNING: profiler attempt to access an invalid memory location\n");
} else {
// Get backtrace data
bt_size_cur += rec_backtrace_ctx((uintptr_t*)bt_data_prof + bt_size_cur,
bt_size_max - bt_size_cur - 1, signal_context);
}
ptls->safe_restore = old_buf;
// Mark the end of this block with 0
bt_data_prof[bt_size_cur++] = 0;
}
if (bt_size_cur >= bt_size_max - 1) {
// Buffer full: Delete the timer
jl_profile_stop_timer();
}
}
// notify thread to resume
jl_thread_resume(i, sig);
}
#endif
// this part is async with the running of the rest of the program
// and must be thread-safe, but not necessarily signal-handler safe
if (critical) {
jl_critical_error(sig, NULL, bt_data, &bt_size);
if (doexit) {
thread0_exit_count++;
jl_exit_thread0(128 + sig);
}
}
}
return NULL;
}
