| //===-- MachException.cpp ---------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Created by Greg Clayton on 6/18/07. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "MachException.h" |
| #include "DNB.h" |
| #include "DNBError.h" |
| #include "DNBLog.h" |
| #include "MachProcess.h" |
| #include "PThreadMutex.h" |
| #include "SysSignal.h" |
| #include <errno.h> |
| #include <sys/ptrace.h> |
| #include <sys/types.h> |
| |
| // Routine mach_exception_raise |
| extern "C" kern_return_t |
| catch_mach_exception_raise(mach_port_t exception_port, mach_port_t thread, |
| mach_port_t task, exception_type_t exception, |
| mach_exception_data_t code, |
| mach_msg_type_number_t codeCnt); |
| |
| extern "C" kern_return_t catch_mach_exception_raise_state( |
| mach_port_t exception_port, exception_type_t exception, |
| const mach_exception_data_t code, mach_msg_type_number_t codeCnt, |
| int *flavor, const thread_state_t old_state, |
| mach_msg_type_number_t old_stateCnt, thread_state_t new_state, |
| mach_msg_type_number_t *new_stateCnt); |
| |
| // Routine mach_exception_raise_state_identity |
| extern "C" kern_return_t catch_mach_exception_raise_state_identity( |
| mach_port_t exception_port, mach_port_t thread, mach_port_t task, |
| exception_type_t exception, mach_exception_data_t code, |
| mach_msg_type_number_t codeCnt, int *flavor, thread_state_t old_state, |
| mach_msg_type_number_t old_stateCnt, thread_state_t new_state, |
| mach_msg_type_number_t *new_stateCnt); |
| |
| extern "C" boolean_t mach_exc_server(mach_msg_header_t *InHeadP, |
| mach_msg_header_t *OutHeadP); |
| |
| // Note: g_message points to the storage allocated to catch the data from |
| // catching the current exception raise. It's populated when we catch a raised |
| // exception which can't immediately be replied to. |
| // |
| // If it becomes possible to catch exceptions from multiple threads |
| // simultaneously, accesses to g_message would need to be mutually exclusive. |
| static MachException::Data *g_message = NULL; |
| |
| extern "C" kern_return_t catch_mach_exception_raise_state( |
| mach_port_t exc_port, exception_type_t exc_type, |
| const mach_exception_data_t exc_data, mach_msg_type_number_t exc_data_count, |
| int *flavor, const thread_state_t old_state, |
| mach_msg_type_number_t old_stateCnt, thread_state_t new_state, |
| mach_msg_type_number_t *new_stateCnt) { |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) { |
| DNBLogThreaded("::%s ( exc_port = 0x%4.4x, exc_type = %d ( %s ), exc_data " |
| "= 0x%llx, exc_data_count = %d)", |
| __FUNCTION__, exc_port, exc_type, |
| MachException::Name(exc_type), (uint64_t)exc_data, |
| exc_data_count); |
| } |
| return KERN_FAILURE; |
| } |
| |
| extern "C" kern_return_t catch_mach_exception_raise_state_identity( |
| mach_port_t exc_port, mach_port_t thread_port, mach_port_t task_port, |
| exception_type_t exc_type, mach_exception_data_t exc_data, |
| mach_msg_type_number_t exc_data_count, int *flavor, |
| thread_state_t old_state, mach_msg_type_number_t old_stateCnt, |
| thread_state_t new_state, mach_msg_type_number_t *new_stateCnt) { |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) { |
| DNBLogThreaded("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = " |
| "0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%llx, " |
| "0x%llx })", |
| __FUNCTION__, exc_port, thread_port, task_port, exc_type, |
| MachException::Name(exc_type), exc_data_count, |
| (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD), |
| (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD)); |
| } |
| |
| return KERN_FAILURE; |
| } |
| |
| extern "C" kern_return_t |
| catch_mach_exception_raise(mach_port_t exc_port, mach_port_t thread_port, |
| mach_port_t task_port, exception_type_t exc_type, |
| mach_exception_data_t exc_data, |
| mach_msg_type_number_t exc_data_count) { |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) { |
| DNBLogThreaded("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = " |
| "0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%llx, " |
| "0x%llx })", |
| __FUNCTION__, exc_port, thread_port, task_port, exc_type, |
| MachException::Name(exc_type), exc_data_count, |
| (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD), |
| (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD)); |
| } |
| g_message->exc_type = 0; |
| g_message->exc_data.clear(); |
| |
| if (task_port == g_message->task_port) { |
| g_message->task_port = task_port; |
| g_message->thread_port = thread_port; |
| g_message->exc_type = exc_type; |
| g_message->AppendExceptionData(exc_data, exc_data_count); |
| return KERN_SUCCESS; |
| } else if (!MachTask::IsValid(g_message->task_port)) { |
| // Our original exception port isn't valid anymore check for a SIGTRAP |
| if (exc_type == EXC_SOFTWARE && exc_data_count == 2 && |
| exc_data[0] == EXC_SOFT_SIGNAL && exc_data[1] == SIGTRAP) { |
| // We got a SIGTRAP which indicates we might have exec'ed and possibly |
| // lost our old task port during the exec, so we just need to switch over |
| // to using this new task port |
| g_message->task_port = task_port; |
| g_message->thread_port = thread_port; |
| g_message->exc_type = exc_type; |
| g_message->AppendExceptionData(exc_data, exc_data_count); |
| return KERN_SUCCESS; |
| } |
| } |
| return KERN_FAILURE; |
| } |
| |
| void MachException::Message::Dump() const { |
| DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_msg { bits = 0x%8.8x size = 0x%8.8x " |
| "remote-port = 0x%8.8x local-port = 0x%8.8x " |
| "reserved = 0x%8.8x id = 0x%8.8x } ", |
| exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size, |
| exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port, |
| exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id); |
| |
| DNBLogThreadedIf(LOG_EXCEPTIONS, "reply_msg { bits = 0x%8.8x size = 0x%8.8x " |
| "remote-port = 0x%8.8x local-port = 0x%8.8x " |
| "reserved = 0x%8.8x id = 0x%8.8x }", |
| reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size, |
| reply_msg.hdr.msgh_remote_port, |
| reply_msg.hdr.msgh_local_port, reply_msg.hdr.msgh_reserved, |
| reply_msg.hdr.msgh_id); |
| |
| state.Dump(); |
| } |
| |
| bool MachException::Data::GetStopInfo( |
| struct DNBThreadStopInfo *stop_info) const { |
| // Zero out the structure. |
| memset(stop_info, 0, sizeof(struct DNBThreadStopInfo)); |
| |
| if (exc_type == 0) { |
| stop_info->reason = eStopTypeInvalid; |
| return true; |
| } |
| |
| // We always stop with a mach exceptions |
| stop_info->reason = eStopTypeException; |
| // Save the EXC_XXXX exception type |
| stop_info->details.exception.type = exc_type; |
| |
| // Fill in a text description |
| const char *exc_name = MachException::Name(exc_type); |
| char *desc = stop_info->description; |
| const char *end_desc = desc + DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH; |
| if (exc_name) |
| desc += |
| snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%s", exc_name); |
| else |
| desc += |
| snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%i", exc_type); |
| |
| stop_info->details.exception.data_count = exc_data.size(); |
| |
| int soft_signal = SoftSignal(); |
| if (soft_signal) { |
| if (desc < end_desc) { |
| const char *sig_str = SysSignal::Name(soft_signal); |
| snprintf(desc, end_desc - desc, " EXC_SOFT_SIGNAL( %i ( %s ))", |
| soft_signal, sig_str ? sig_str : "unknown signal"); |
| } |
| } else { |
| // No special disassembly for exception data, just |
| size_t idx; |
| if (desc < end_desc) { |
| desc += snprintf(desc, end_desc - desc, " data[%llu] = {", |
| (uint64_t)stop_info->details.exception.data_count); |
| |
| for (idx = 0; |
| desc < end_desc && idx < stop_info->details.exception.data_count; |
| ++idx) |
| desc += snprintf( |
| desc, end_desc - desc, "0x%llx%c", (uint64_t)exc_data[idx], |
| ((idx + 1 == stop_info->details.exception.data_count) ? '}' : ',')); |
| } |
| } |
| |
| // Copy the exception data |
| size_t i; |
| for (i = 0; i < stop_info->details.exception.data_count; i++) |
| stop_info->details.exception.data[i] = exc_data[i]; |
| |
| return true; |
| } |
| |
| void MachException::Data::DumpStopReason() const { |
| int soft_signal = SoftSignal(); |
| if (soft_signal) { |
| const char *signal_str = SysSignal::Name(soft_signal); |
| if (signal_str) |
| DNBLog("signal(%s)", signal_str); |
| else |
| DNBLog("signal(%i)", soft_signal); |
| return; |
| } |
| DNBLog("%s", Name(exc_type)); |
| } |
| |
| kern_return_t MachException::Message::Receive(mach_port_t port, |
| mach_msg_option_t options, |
| mach_msg_timeout_t timeout, |
| mach_port_t notify_port) { |
| DNBError err; |
| const bool log_exceptions = DNBLogCheckLogBit(LOG_EXCEPTIONS); |
| mach_msg_timeout_t mach_msg_timeout = |
| options & MACH_RCV_TIMEOUT ? timeout : 0; |
| if (log_exceptions && ((options & MACH_RCV_TIMEOUT) == 0)) { |
| // Dump this log message if we have no timeout in case it never returns |
| DNBLogThreaded("::mach_msg ( msg->{bits = %#x, size = %u remote_port = " |
| "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, option " |
| "= %#x, send_size = 0, rcv_size = %llu, rcv_name = %#x, " |
| "timeout = %u, notify = %#x)", |
| exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size, |
| exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port, |
| exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options, |
| (uint64_t)sizeof(exc_msg.data), port, mach_msg_timeout, |
| notify_port); |
| } |
| |
| err = ::mach_msg(&exc_msg.hdr, |
| options, // options |
| 0, // Send size |
| sizeof(exc_msg.data), // Receive size |
| port, // exception port to watch for exception on |
| mach_msg_timeout, // timeout in msec (obeyed only if |
| // MACH_RCV_TIMEOUT is ORed into the |
| // options parameter) |
| notify_port); |
| |
| // Dump any errors we get |
| if (log_exceptions) { |
| err.LogThreaded("::mach_msg ( msg->{bits = %#x, size = %u remote_port = " |
| "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, " |
| "option = %#x, send_size = %u, rcv_size = %u, rcv_name = " |
| "%#x, timeout = %u, notify = %#x)", |
| exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size, |
| exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port, |
| exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options, 0, |
| sizeof(exc_msg.data), port, mach_msg_timeout, notify_port); |
| } |
| return err.Status(); |
| } |
| |
| bool MachException::Message::CatchExceptionRaise(task_t task) { |
| bool success = false; |
| state.task_port = task; |
| g_message = &state; |
| // The exc_server function is the MIG generated server handling function |
| // to handle messages from the kernel relating to the occurrence of an |
| // exception in a thread. Such messages are delivered to the exception port |
| // set via thread_set_exception_ports or task_set_exception_ports. When an |
| // exception occurs in a thread, the thread sends an exception message to |
| // its exception port, blocking in the kernel waiting for the receipt of a |
| // reply. The exc_server function performs all necessary argument handling |
| // for this kernel message and calls catch_exception_raise, |
| // catch_exception_raise_state or catch_exception_raise_state_identity, |
| // which should handle the exception. If the called routine returns |
| // KERN_SUCCESS, a reply message will be sent, allowing the thread to |
| // continue from the point of the exception; otherwise, no reply message |
| // is sent and the called routine must have dealt with the exception |
| // thread directly. |
| if (mach_exc_server(&exc_msg.hdr, &reply_msg.hdr)) { |
| success = true; |
| } else if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) { |
| DNBLogThreaded("mach_exc_server returned zero..."); |
| } |
| g_message = NULL; |
| return success; |
| } |
| |
| kern_return_t MachException::Message::Reply(MachProcess *process, int signal) { |
| // Reply to the exception... |
| DNBError err; |
| |
| // If we had a soft signal, we need to update the thread first so it can |
| // continue without signaling |
| int soft_signal = state.SoftSignal(); |
| if (soft_signal) { |
| int state_pid = -1; |
| if (process->Task().TaskPort() == state.task_port) { |
| // This is our task, so we can update the signal to send to it |
| state_pid = process->ProcessID(); |
| soft_signal = signal; |
| } else { |
| err = ::pid_for_task(state.task_port, &state_pid); |
| } |
| |
| assert(state_pid != -1); |
| if (state_pid != -1) { |
| errno = 0; |
| if (::ptrace(PT_THUPDATE, state_pid, |
| (caddr_t)((uintptr_t)state.thread_port), soft_signal) != 0) |
| err.SetError(errno, DNBError::POSIX); |
| else |
| err.Clear(); |
| |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) |
| err.LogThreaded("::ptrace (request = PT_THUPDATE, pid = 0x%4.4x, tid = " |
| "0x%4.4x, signal = %i)", |
| state_pid, state.thread_port, soft_signal); |
| } |
| } |
| |
| DNBLogThreadedIf( |
| LOG_EXCEPTIONS, "::mach_msg ( msg->{bits = %#x, size = %u, remote_port = " |
| "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, " |
| "option = %#x, send_size = %u, rcv_size = %u, rcv_name = " |
| "%#x, timeout = %u, notify = %#x)", |
| reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size, |
| reply_msg.hdr.msgh_remote_port, reply_msg.hdr.msgh_local_port, |
| reply_msg.hdr.msgh_reserved, reply_msg.hdr.msgh_id, |
| MACH_SEND_MSG | MACH_SEND_INTERRUPT, reply_msg.hdr.msgh_size, 0, |
| MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| |
| err = ::mach_msg(&reply_msg.hdr, MACH_SEND_MSG | MACH_SEND_INTERRUPT, |
| reply_msg.hdr.msgh_size, 0, MACH_PORT_NULL, |
| MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| |
| if (err.Fail()) { |
| if (err.Status() == MACH_SEND_INTERRUPTED) { |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) |
| err.LogThreaded("::mach_msg() - send interrupted"); |
| // TODO: keep retrying to reply??? |
| } else { |
| if (state.task_port == process->Task().TaskPort()) { |
| DNBLogThreaded("error: mach_msg() returned an error when replying to a " |
| "mach exception: error = %u", |
| err.Status()); |
| } else { |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) |
| err.LogThreaded("::mach_msg() - failed (child of task)"); |
| } |
| } |
| } |
| |
| return err.Status(); |
| } |
| |
| void MachException::Data::Dump() const { |
| const char *exc_type_name = MachException::Name(exc_type); |
| DNBLogThreadedIf( |
| LOG_EXCEPTIONS, " state { task_port = 0x%4.4x, thread_port = " |
| "0x%4.4x, exc_type = %i (%s) ...", |
| task_port, thread_port, exc_type, exc_type_name ? exc_type_name : "???"); |
| |
| const size_t exc_data_count = exc_data.size(); |
| // Dump any special exception data contents |
| int soft_signal = SoftSignal(); |
| if (soft_signal != 0) { |
| const char *sig_str = SysSignal::Name(soft_signal); |
| DNBLogThreadedIf(LOG_EXCEPTIONS, |
| " exc_data: EXC_SOFT_SIGNAL (%i (%s))", |
| soft_signal, sig_str ? sig_str : "unknown signal"); |
| } else { |
| // No special disassembly for this data, just dump the data |
| size_t idx; |
| for (idx = 0; idx < exc_data_count; ++idx) { |
| DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_data[%llu]: 0x%llx", |
| (uint64_t)idx, (uint64_t)exc_data[idx]); |
| } |
| } |
| } |
| |
| #define PREV_EXC_MASK_ALL \ |
| (EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC | \ |
| EXC_MASK_EMULATION | EXC_MASK_SOFTWARE | EXC_MASK_BREAKPOINT | \ |
| EXC_MASK_SYSCALL | EXC_MASK_MACH_SYSCALL | EXC_MASK_RPC_ALERT | \ |
| EXC_MASK_MACHINE) |
| |
| // Don't listen for EXC_RESOURCE, it should really get handled by the system |
| // handler. |
| |
| #ifndef EXC_RESOURCE |
| #define EXC_RESOURCE 11 |
| #endif |
| |
| #ifndef EXC_MASK_RESOURCE |
| #define EXC_MASK_RESOURCE (1 << EXC_RESOURCE) |
| #endif |
| |
| #define LLDB_EXC_MASK (EXC_MASK_ALL & ~EXC_MASK_RESOURCE) |
| |
| kern_return_t MachException::PortInfo::Save(task_t task) { |
| DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE, |
| "MachException::PortInfo::Save ( task = 0x%4.4x )", task); |
| // Be careful to be able to have debugserver built on a newer OS than what |
| // it is currently running on by being able to start with all exceptions |
| // and back off to just what is supported on the current system |
| DNBError err; |
| |
| mask = LLDB_EXC_MASK; |
| |
| count = (sizeof(ports) / sizeof(ports[0])); |
| err = ::task_get_exception_ports(task, mask, masks, &count, ports, behaviors, |
| flavors); |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) |
| err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = 0x%x, " |
| "maskCnt => %u, ports, behaviors, flavors )", |
| task, mask, count); |
| |
| if (err.Status() == KERN_INVALID_ARGUMENT && mask != PREV_EXC_MASK_ALL) { |
| mask = PREV_EXC_MASK_ALL; |
| count = (sizeof(ports) / sizeof(ports[0])); |
| err = ::task_get_exception_ports(task, mask, masks, &count, ports, |
| behaviors, flavors); |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) |
| err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = " |
| "0x%x, maskCnt => %u, ports, behaviors, flavors )", |
| task, mask, count); |
| } |
| if (err.Fail()) { |
| mask = 0; |
| count = 0; |
| } |
| return err.Status(); |
| } |
| |
| kern_return_t MachException::PortInfo::Restore(task_t task) { |
| DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE, |
| "MachException::PortInfo::Restore( task = 0x%4.4x )", task); |
| uint32_t i = 0; |
| DNBError err; |
| if (count > 0) { |
| for (i = 0; i < count; i++) { |
| err = ::task_set_exception_ports(task, masks[i], ports[i], behaviors[i], |
| flavors[i]); |
| if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) { |
| err.LogThreaded("::task_set_exception_ports ( task = 0x%4.4x, " |
| "exception_mask = 0x%8.8x, new_port = 0x%4.4x, " |
| "behavior = 0x%8.8x, new_flavor = 0x%8.8x )", |
| task, masks[i], ports[i], behaviors[i], flavors[i]); |
| // Bail if we encounter any errors |
| } |
| |
| if (err.Fail()) |
| break; |
| } |
| } |
| count = 0; |
| return err.Status(); |
| } |
| |
| const char *MachException::Name(exception_type_t exc_type) { |
| switch (exc_type) { |
| case EXC_BAD_ACCESS: |
| return "EXC_BAD_ACCESS"; |
| case EXC_BAD_INSTRUCTION: |
| return "EXC_BAD_INSTRUCTION"; |
| case EXC_ARITHMETIC: |
| return "EXC_ARITHMETIC"; |
| case EXC_EMULATION: |
| return "EXC_EMULATION"; |
| case EXC_SOFTWARE: |
| return "EXC_SOFTWARE"; |
| case EXC_BREAKPOINT: |
| return "EXC_BREAKPOINT"; |
| case EXC_SYSCALL: |
| return "EXC_SYSCALL"; |
| case EXC_MACH_SYSCALL: |
| return "EXC_MACH_SYSCALL"; |
| case EXC_RPC_ALERT: |
| return "EXC_RPC_ALERT"; |
| #ifdef EXC_CRASH |
| case EXC_CRASH: |
| return "EXC_CRASH"; |
| #endif |
| default: |
| break; |
| } |
| return NULL; |
| } |
