//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_exception_state64_t exc_state;
x86_thread_state64_t state;
#ifdef LIBOSXUNWIND
if (thread == mach_profiler_thread) {
return profiler_segv_handler(exception_port, thread, task, exception, code, code_count);
}
#endif
kern_return_t ret = thread_get_state(thread, x86_EXCEPTION_STATE64, (thread_state_t)&exc_state, &exc_count);
HANDLE_MACH_ERROR("thread_get_state", 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
jl_value_t *excpt;
if (is_addr_on_stack((void*)fault_addr)) {
excpt = jl_stackovf_exception;
}
#ifdef SEGV_EXCEPTION
else if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) != 0) {
// no page mapped at this address
excpt = jl_segv_exception;
}
#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
excpt = jl_readonlymemory_exception;
}
jl_throw_in_thread(0, thread, excpt);
return KERN_SUCCESS;
}
else {
kern_return_t ret = thread_get_state(thread, x86_THREAD_STATE64, (thread_state_t)&state, &count);
HANDLE_MACH_ERROR("thread_get_state", ret);
jl_critical_error(SIGSEGV, (unw_context_t*)&state,
jl_bt_data, &jl_bt_size);
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);
}
//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);
}
//exc_server uses dlsym to find symbol
JL_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_exception_state64_t exc_state;
x86_thread_state64_t state;
#ifdef LIBOSXUNWIND
if (thread == mach_profiler_thread) {
return profiler_segv_handler(exception_port, thread, task, exception, code, code_count);
}
#endif
int16_t tid;
#ifdef JULIA_ENABLE_THREADING
jl_tls_states_t *ptls = NULL;
for (tid = 0;tid < jl_n_threads;tid++) {
if (pthread_mach_thread_np(jl_all_task_states[tid].system_id) == thread) {
ptls = jl_all_task_states[tid].ptls;
break;
}
}
if (!ptls) {
// We don't know about this thread, let the kernel try another handler
// instead. This shouldn't actually happen since we only register the
// handler for the threads we know about.
jl_safe_printf("ERROR: Exception handler triggered on unmanaged thread.\n");
return KERN_INVALID_ARGUMENT;
}
#else
jl_tls_states_t *ptls = &jl_tls_states;
tid = 0;
#endif
kern_return_t ret = thread_get_state(thread, x86_EXCEPTION_STATE64, (thread_state_t)&exc_state, &exc_count);
HANDLE_MACH_ERROR("thread_get_state", ret);
uint64_t fault_addr = exc_state.__faultvaddr;
#ifdef JULIA_ENABLE_THREADING
if (fault_addr == (uintptr_t)jl_gc_signal_page) {
JL_LOCK_NOGC(gc_suspend);
if (!jl_gc_safepoint_activated) {
// GC is done before we get the message, do nothing and return
JL_UNLOCK_NOGC(gc_suspend);
return KERN_SUCCESS;
}
// Otherwise, set the gc state of the thread, suspend and record it
int8_t gc_state = ptls->gc_state;
ptls->gc_state = JL_GC_STATE_WAITING;
uintptr_t item = tid | (((uintptr_t)gc_state) << 16);
arraylist_push(&suspended_threads, (void*)item);
thread_suspend(thread);
JL_UNLOCK_NOGC(gc_suspend);
return KERN_SUCCESS;
}
#endif
#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
jl_value_t *excpt;
if (is_addr_on_stack(ptls, (void*)fault_addr)) {
excpt = jl_stackovf_exception;
}
#ifdef SEGV_EXCEPTION
else if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) != 0) {
// no page mapped at this address
excpt = jl_segv_exception;
}
#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
excpt = jl_readonlymemory_exception;
}
jl_throw_in_thread(tid, thread, excpt);
return KERN_SUCCESS;
}
else {
kern_return_t ret = thread_get_state(thread, x86_THREAD_STATE64, (thread_state_t)&state, &count);
HANDLE_MACH_ERROR("thread_get_state", ret);
jl_critical_error(SIGSEGV, (unw_context_t*)&state,
ptls->bt_data, &ptls->bt_size);
return KERN_INVALID_ARGUMENT;
}
}
static void attach_exception_port(thread_port_t thread)
{
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(thread, EXC_MASK_BAD_ACCESS, segv_port, EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
HANDLE_MACH_ERROR("thread_set_exception_ports", ret);
}