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//===-- StopInfoMachException.cpp -------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "StopInfoMachException.h"
#if defined(__APPLE__)
// Needed for the EXC_RESOURCE interpretation macros
#include <kern/exc_resource.h>
#endif
#include "lldb/Breakpoint/Watchpoint.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Target/DynamicLoader.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/UnixSignals.h"
#include "lldb/Utility/StreamString.h"
using namespace lldb;
using namespace lldb_private;
const char *StopInfoMachException::GetDescription() {
if (!m_description.empty())
return m_description.c_str();
if (GetValue() == eStopReasonInvalid)
return "invalid stop reason!";
ExecutionContext exe_ctx(m_thread_wp.lock());
Target *target = exe_ctx.GetTargetPtr();
const llvm::Triple::ArchType cpu =
target ? target->GetArchitecture().GetMachine()
: llvm::Triple::UnknownArch;
const char *exc_desc = nullptr;
const char *code_label = "code";
const char *code_desc = nullptr;
const char *subcode_label = "subcode";
const char *subcode_desc = nullptr;
#if defined(__APPLE__)
char code_desc_buf[32];
char subcode_desc_buf[32];
#endif
switch (m_value) {
case 1: // EXC_BAD_ACCESS
exc_desc = "EXC_BAD_ACCESS";
subcode_label = "address";
switch (cpu) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
switch (m_exc_code) {
case 0xd:
code_desc = "EXC_I386_GPFLT";
m_exc_data_count = 1;
break;
}
break;
case llvm::Triple::arm:
case llvm::Triple::thumb:
switch (m_exc_code) {
case 0x101:
code_desc = "EXC_ARM_DA_ALIGN";
break;
case 0x102:
code_desc = "EXC_ARM_DA_DEBUG";
break;
}
break;
default:
break;
}
break;
case 2: // EXC_BAD_INSTRUCTION
exc_desc = "EXC_BAD_INSTRUCTION";
switch (cpu) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
if (m_exc_code == 1)
code_desc = "EXC_I386_INVOP";
break;
case llvm::Triple::arm:
case llvm::Triple::thumb:
if (m_exc_code == 1)
code_desc = "EXC_ARM_UNDEFINED";
break;
default:
break;
}
break;
case 3: // EXC_ARITHMETIC
exc_desc = "EXC_ARITHMETIC";
switch (cpu) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
switch (m_exc_code) {
case 1:
code_desc = "EXC_I386_DIV";
break;
case 2:
code_desc = "EXC_I386_INTO";
break;
case 3:
code_desc = "EXC_I386_NOEXT";
break;
case 4:
code_desc = "EXC_I386_EXTOVR";
break;
case 5:
code_desc = "EXC_I386_EXTERR";
break;
case 6:
code_desc = "EXC_I386_EMERR";
break;
case 7:
code_desc = "EXC_I386_BOUND";
break;
case 8:
code_desc = "EXC_I386_SSEEXTERR";
break;
}
break;
default:
break;
}
break;
case 4: // EXC_EMULATION
exc_desc = "EXC_EMULATION";
break;
case 5: // EXC_SOFTWARE
exc_desc = "EXC_SOFTWARE";
if (m_exc_code == 0x10003) {
subcode_desc = "EXC_SOFT_SIGNAL";
subcode_label = "signo";
}
break;
case 6: // EXC_BREAKPOINT
{
exc_desc = "EXC_BREAKPOINT";
switch (cpu) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
switch (m_exc_code) {
case 1:
code_desc = "EXC_I386_SGL";
break;
case 2:
code_desc = "EXC_I386_BPT";
break;
}
break;
case llvm::Triple::arm:
case llvm::Triple::thumb:
switch (m_exc_code) {
case 0x101:
code_desc = "EXC_ARM_DA_ALIGN";
break;
case 0x102:
code_desc = "EXC_ARM_DA_DEBUG";
break;
case 1:
code_desc = "EXC_ARM_BREAKPOINT";
break;
// FIXME temporary workaround, exc_code 0 does not really mean
// EXC_ARM_BREAKPOINT
case 0:
code_desc = "EXC_ARM_BREAKPOINT";
break;
}
break;
default:
break;
}
} break;
case 7:
exc_desc = "EXC_SYSCALL";
break;
case 8:
exc_desc = "EXC_MACH_SYSCALL";
break;
case 9:
exc_desc = "EXC_RPC_ALERT";
break;
case 10:
exc_desc = "EXC_CRASH";
break;
case 11:
exc_desc = "EXC_RESOURCE";
#if defined(__APPLE__)
{
int resource_type = EXC_RESOURCE_DECODE_RESOURCE_TYPE(m_exc_code);
code_label = "limit";
code_desc = code_desc_buf;
subcode_label = "observed";
subcode_desc = subcode_desc_buf;
switch (resource_type) {
case RESOURCE_TYPE_CPU:
exc_desc = "EXC_RESOURCE RESOURCE_TYPE_CPU";
snprintf(code_desc_buf, sizeof(code_desc_buf), "%d%%",
(int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE(m_exc_code));
snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d%%",
(int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE_OBSERVED(
m_exc_subcode));
break;
case RESOURCE_TYPE_WAKEUPS:
exc_desc = "EXC_RESOURCE RESOURCE_TYPE_WAKEUPS";
snprintf(
code_desc_buf, sizeof(code_desc_buf), "%d w/s",
(int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_PERMITTED(m_exc_code));
snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d w/s",
(int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_OBSERVED(
m_exc_subcode));
break;
case RESOURCE_TYPE_MEMORY:
exc_desc = "EXC_RESOURCE RESOURCE_TYPE_MEMORY";
snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB",
(int)EXC_RESOURCE_HWM_DECODE_LIMIT(m_exc_code));
subcode_desc = nullptr;
subcode_label = "unused";
break;
#if defined(RESOURCE_TYPE_IO)
// RESOURCE_TYPE_IO is introduced in macOS SDK 10.12.
case RESOURCE_TYPE_IO:
exc_desc = "EXC_RESOURCE RESOURCE_TYPE_IO";
snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB",
(int)EXC_RESOURCE_IO_DECODE_LIMIT(m_exc_code));
snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d MB",
(int)EXC_RESOURCE_IO_OBSERVED(m_exc_subcode));
;
break;
#endif
}
}
#endif
break;
case 12:
exc_desc = "EXC_GUARD";
break;
}
StreamString strm;
if (exc_desc)
strm.PutCString(exc_desc);
else
strm.Printf("EXC_??? (%" PRIu64 ")", m_value);
if (m_exc_data_count >= 1) {
if (code_desc)
strm.Printf(" (%s=%s", code_label, code_desc);
else
strm.Printf(" (%s=%" PRIu64, code_label, m_exc_code);
}
if (m_exc_data_count >= 2) {
if (subcode_desc)
strm.Printf(", %s=%s", subcode_label, subcode_desc);
else
strm.Printf(", %s=0x%" PRIx64, subcode_label, m_exc_subcode);
}
if (m_exc_data_count > 0)
strm.PutChar(')');
m_description = strm.GetString();
return m_description.c_str();
}
StopInfoSP StopInfoMachException::CreateStopReasonWithMachException(
Thread &thread, uint32_t exc_type, uint32_t exc_data_count,
uint64_t exc_code, uint64_t exc_sub_code, uint64_t exc_sub_sub_code,
bool pc_already_adjusted, bool adjust_pc_if_needed) {
if (exc_type == 0)
return StopInfoSP();
uint32_t pc_decrement = 0;
ExecutionContext exe_ctx(thread.shared_from_this());
Target *target = exe_ctx.GetTargetPtr();
const llvm::Triple::ArchType cpu =
target ? target->GetArchitecture().GetMachine()
: llvm::Triple::UnknownArch;
switch (exc_type) {
case 1: // EXC_BAD_ACCESS
case 2: // EXC_BAD_INSTRUCTION
case 3: // EXC_ARITHMETIC
case 4: // EXC_EMULATION
break;
case 5: // EXC_SOFTWARE
if (exc_code == 0x10003) // EXC_SOFT_SIGNAL
{
if (exc_sub_code == 5) {
// On MacOSX, a SIGTRAP can signify that a process has called exec,
// so we should check with our dynamic loader to verify.
ProcessSP process_sp(thread.GetProcess());
if (process_sp) {
DynamicLoader *dynamic_loader = process_sp->GetDynamicLoader();
if (dynamic_loader && dynamic_loader->ProcessDidExec()) {
// The program was re-exec'ed
return StopInfo::CreateStopReasonWithExec(thread);
}
}
}
return StopInfo::CreateStopReasonWithSignal(thread, exc_sub_code);
}
break;
case 6: // EXC_BREAKPOINT
{
bool is_actual_breakpoint = false;
bool is_trace_if_actual_breakpoint_missing = false;
switch (cpu) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
if (exc_code == 1) // EXC_I386_SGL
{
if (!exc_sub_code) {
// This looks like a plain trap.
// Have to check if there is a breakpoint here as well. When you
// single-step onto a trap, the single step stops you not to trap.
// Since we also do that check below, let's just use that logic.
is_actual_breakpoint = true;
is_trace_if_actual_breakpoint_missing = true;
} else {
// It's a watchpoint, then.
// The exc_sub_code indicates the data break address.
lldb::WatchpointSP wp_sp;
if (target)
wp_sp = target->GetWatchpointList().FindByAddress(
(lldb::addr_t)exc_sub_code);
if (wp_sp && wp_sp->IsEnabled()) {
// Debugserver may piggyback the hardware index of the fired
// watchpoint in the exception data. Set the hardware index if
// that's the case.
if (exc_data_count >= 3)
wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code);
return StopInfo::CreateStopReasonWithWatchpointID(thread,
wp_sp->GetID());
}
}
} else if (exc_code == 2 || // EXC_I386_BPT
exc_code == 3) // EXC_I386_BPTFLT
{
// KDP returns EXC_I386_BPTFLT for trace breakpoints
if (exc_code == 3)
is_trace_if_actual_breakpoint_missing = true;
is_actual_breakpoint = true;
if (!pc_already_adjusted)
pc_decrement = 1;
}
break;
case llvm::Triple::arm:
case llvm::Triple::thumb:
if (exc_code == 0x102) // EXC_ARM_DA_DEBUG
{
// It's a watchpoint, then, if the exc_sub_code indicates a
// known/enabled data break address from our watchpoint list.
lldb::WatchpointSP wp_sp;
if (target)
wp_sp = target->GetWatchpointList().FindByAddress(
(lldb::addr_t)exc_sub_code);
if (wp_sp && wp_sp->IsEnabled()) {
// Debugserver may piggyback the hardware index of the fired
// watchpoint in the exception data. Set the hardware index if
// that's the case.
if (exc_data_count >= 3)
wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code);
return StopInfo::CreateStopReasonWithWatchpointID(thread,
wp_sp->GetID());
} else {
is_actual_breakpoint = true;
is_trace_if_actual_breakpoint_missing = true;
}
} else if (exc_code == 1) // EXC_ARM_BREAKPOINT
{
is_actual_breakpoint = true;
is_trace_if_actual_breakpoint_missing = true;
} else if (exc_code == 0) // FIXME not EXC_ARM_BREAKPOINT but a kernel
// is currently returning this so accept it
// as indicating a breakpoint until the
// kernel is fixed
{
is_actual_breakpoint = true;
is_trace_if_actual_breakpoint_missing = true;
}
break;
case llvm::Triple::aarch64_32:
case llvm::Triple::aarch64: {
if (exc_code == 1 && exc_sub_code == 0) // EXC_ARM_BREAKPOINT
{
// This is hit when we single instruction step aka MDSCR_EL1 SS bit 0
// is set
is_actual_breakpoint = false;
is_trace_if_actual_breakpoint_missing = true;
}
if (exc_code == 0x102) // EXC_ARM_DA_DEBUG
{
// It's a watchpoint, then, if the exc_sub_code indicates a
// known/enabled data break address from our watchpoint list.
lldb::WatchpointSP wp_sp;
if (target)
wp_sp = target->GetWatchpointList().FindByAddress(
(lldb::addr_t)exc_sub_code);
if (wp_sp && wp_sp->IsEnabled()) {
// Debugserver may piggyback the hardware index of the fired
// watchpoint in the exception data. Set the hardware index if
// that's the case.
if (exc_data_count >= 3)
wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code);
return StopInfo::CreateStopReasonWithWatchpointID(thread,
wp_sp->GetID());
}
// EXC_ARM_DA_DEBUG seems to be reused for EXC_BREAKPOINT as well as
// EXC_BAD_ACCESS
if (thread.GetTemporaryResumeState() == eStateStepping)
return StopInfo::CreateStopReasonToTrace(thread);
}
// It looks like exc_sub_code has the 4 bytes of the instruction that
// triggered the exception, i.e. our breakpoint opcode
is_actual_breakpoint = exc_code == 1;
break;
}
default:
break;
}
if (is_actual_breakpoint) {
RegisterContextSP reg_ctx_sp(thread.GetRegisterContext());
addr_t pc = reg_ctx_sp->GetPC() - pc_decrement;
ProcessSP process_sp(thread.CalculateProcess());
lldb::BreakpointSiteSP bp_site_sp;
if (process_sp)
bp_site_sp = process_sp->GetBreakpointSiteList().FindByAddress(pc);
if (bp_site_sp && bp_site_sp->IsEnabled()) {
// Update the PC if we were asked to do so, but only do so if we find
// a breakpoint that we know about cause this could be a trap
// instruction in the code
if (pc_decrement > 0 && adjust_pc_if_needed)
reg_ctx_sp->SetPC(pc);
// If the breakpoint is for this thread, then we'll report the hit,
// but if it is for another thread, we can just report no reason. We
// don't need to worry about stepping over the breakpoint here, that
// will be taken care of when the thread resumes and notices that
// there's a breakpoint under the pc. If we have an operating system
// plug-in, we might have set a thread specific breakpoint using the
// operating system thread ID, so we can't make any assumptions about
// the thread ID so we must always report the breakpoint regardless
// of the thread.
if (bp_site_sp->ValidForThisThread(&thread) ||
thread.GetProcess()->GetOperatingSystem() != nullptr)
return StopInfo::CreateStopReasonWithBreakpointSiteID(
thread, bp_site_sp->GetID());
else if (is_trace_if_actual_breakpoint_missing)
return StopInfo::CreateStopReasonToTrace(thread);
else
return StopInfoSP();
}
// Don't call this a trace if we weren't single stepping this thread.
if (is_trace_if_actual_breakpoint_missing &&
thread.GetTemporaryResumeState() == eStateStepping) {
return StopInfo::CreateStopReasonToTrace(thread);
}
}
} break;
case 7: // EXC_SYSCALL
case 8: // EXC_MACH_SYSCALL
case 9: // EXC_RPC_ALERT
case 10: // EXC_CRASH
break;
}
return StopInfoSP(new StopInfoMachException(thread, exc_type, exc_data_count,
exc_code, exc_sub_code));
}