bool UnwindPtrace::Init() {
if (upt_info_) {
return true;
}
if (addr_space_) {
// If somehow the addr_space_ gets initialized but upt_info_ doesn't,
// then that indicates there is some kind of failure.
return false;
}
addr_space_ = unw_create_addr_space(&_UPT_accessors, 0);
if (!addr_space_) {
BACK_LOGW("unw_create_addr_space failed.");
error_ = BACKTRACE_UNWIND_ERROR_SETUP_FAILED;
return false;
}
UnwindMap* map = static_cast<UnwindMap*>(GetMap());
unw_map_set(addr_space_, map->GetMapCursor());
upt_info_ = reinterpret_cast<struct UPT_info*>(_UPT_create(Tid()));
if (!upt_info_) {
BACK_LOGW("Failed to create upt info.");
error_ = BACKTRACE_UNWIND_ERROR_SETUP_FAILED;
return false;
}
return true;
}
UnwindPtrace::~UnwindPtrace() {
if (upt_info_) {
_UPT_destroy(upt_info_);
upt_info_ = NULL;
}
if (addr_space_) {
// Remove the map from the address space before destroying it.
// It will be freed in the UnwindMap destructor.
unw_map_set(addr_space_, NULL);
unw_destroy_addr_space(addr_space_);
addr_space_ = NULL;
}
}
bool UnwindPtrace::Unwind(size_t num_ignore_frames, ucontext_t* ucontext) {
if (ucontext) {
BACK_LOGW("Unwinding from a specified context not supported yet.");
return false;
}
addr_space_ = unw_create_addr_space(&_UPT_accessors, 0);
if (!addr_space_) {
BACK_LOGW("unw_create_addr_space failed.");
return false;
}
UnwindMap* map = static_cast<UnwindMap*>(GetMap());
if (NULL == map) {
BACK_LOGW("GetMap before unwinding failed.");
return false;
}
unw_map_set(addr_space_, map->GetMapCursor());
upt_info_ = reinterpret_cast<struct UPT_info*>(_UPT_create(Tid()));
if (!upt_info_) {
BACK_LOGW("Failed to create upt info.");
return false;
}
unw_cursor_t cursor;
if(num_ignore_frames==0xdeaddead)
{
cursor.opaque[0]=0xdeaddead; //add for tell libunwind to unwind for kernel unwind userspace backtrace,lhd
BACK_LOGW(" K2U_bt call into UnwindPtrace::Unwind.");
num_ignore_frames=0;
}
int ret = unw_init_remote(&cursor, addr_space_, upt_info_);
if (ret < 0) {
BACK_LOGW("unw_init_remote failed %d", ret);
return false;
}
std::vector<backtrace_frame_data_t>* frames = GetFrames();
frames->reserve(MAX_BACKTRACE_FRAMES);
size_t num_frames = 0;
do {
unw_word_t pc;
ret = unw_get_reg(&cursor, UNW_REG_IP, &pc);
if (ret < 0) {
BACK_LOGW("Failed to read IP %d", ret);
break;
}
unw_word_t sp;
ret = unw_get_reg(&cursor, UNW_REG_SP, &sp);
if (ret < 0) {
BACK_LOGW("Failed to read SP %d", ret);
break;
}
if (num_ignore_frames == 0) {
frames->resize(num_frames+1);
backtrace_frame_data_t* frame = &frames->at(num_frames);
frame->num = num_frames;
frame->pc = static_cast<uintptr_t>(pc);
frame->sp = static_cast<uintptr_t>(sp);
frame->stack_size = 0;
if (num_frames > 0) {
backtrace_frame_data_t* prev = &frames->at(num_frames-1);
prev->stack_size = frame->sp - prev->sp;
}
frame->func_name = GetFunctionName(frame->pc, &frame->func_offset);
frame->map = FindMap(frame->pc);
num_frames++;
} else {
num_ignore_frames--;
}
ret = unw_step (&cursor);
} while (ret > 0 && num_frames < MAX_BACKTRACE_FRAMES);
return true;
}
bool UnwindPtrace::Unwind(size_t num_ignore_frames, ucontext_t* ucontext) {
if (GetMap() == nullptr) {
// Without a map object, we can't do anything.
return false;
}
if (ucontext) {
BACK_LOGW("Unwinding from a specified context not supported yet.");
return false;
}
addr_space_ = unw_create_addr_space(&_UPT_accessors, 0);
if (!addr_space_) {
BACK_LOGW("unw_create_addr_space failed.");
return false;
}
UnwindMap* map = static_cast<UnwindMap*>(GetMap());
unw_map_set(addr_space_, map->GetMapCursor());
upt_info_ = reinterpret_cast<struct UPT_info*>(_UPT_create(Tid()));
if (!upt_info_) {
BACK_LOGW("Failed to create upt info.");
return false;
}
unw_cursor_t cursor;
int ret = unw_init_remote(&cursor, addr_space_, upt_info_);
if (ret < 0) {
BACK_LOGW("unw_init_remote failed %d", ret);
return false;
}
size_t num_frames = 0;
do {
unw_word_t pc;
ret = unw_get_reg(&cursor, UNW_REG_IP, &pc);
if (ret < 0) {
BACK_LOGW("Failed to read IP %d", ret);
break;
}
unw_word_t sp;
ret = unw_get_reg(&cursor, UNW_REG_SP, &sp);
if (ret < 0) {
BACK_LOGW("Failed to read SP %d", ret);
break;
}
if (num_ignore_frames == 0) {
frames_.resize(num_frames+1);
backtrace_frame_data_t* frame = &frames_.at(num_frames);
frame->num = num_frames;
frame->pc = static_cast<uintptr_t>(pc);
frame->sp = static_cast<uintptr_t>(sp);
frame->stack_size = 0;
if (num_frames > 0) {
backtrace_frame_data_t* prev = &frames_.at(num_frames-1);
prev->stack_size = frame->sp - prev->sp;
}
frame->func_name = GetFunctionName(frame->pc, &frame->func_offset);
FillInMap(frame->pc, &frame->map);
num_frames++;
} else {
num_ignore_frames--;
}
ret = unw_step (&cursor);
} while (ret > 0 && num_frames < MAX_BACKTRACE_FRAMES);
return true;
}
size_t StackCorkscrewLibunwind::Unwind (pid_t ppid, pid_t tid, size_t ignoreDepth, size_t maxDepth)
{
assert (ppid > 0);
assert (tid >= ppid);
(void) ignoreDepth;
m_frames.clear ();
if (maxDepth == 0)
{
return 0;
}
static unw_addr_space_t addr_space;
(void) addr_space;
#if UNWIND_SUPPORTED && UNWIND_REMOTE_SUPPORTED
addr_space = unw_create_addr_space (&_UPT_accessors, 0);
if (!addr_space)
{
fprintf (stderr, "unw_create_addr_space failed.\n");
fflush (stderr);
return 0;
}
#endif
#if UNWIND_MAP_SUPPORTED && UNWIND_FUNCTION_NAME
unw_map_cursor_t map_cursor;
if (unw_map_cursor_create (&map_cursor, tid) < 0)
{
fprintf (stderr, "Failed to create map cursor.\n");
fflush (stderr);
return 0;
}
unw_map_set (addr_space, &map_cursor);
#endif
#if UNWIND_REMOTE_SUPPORTED
struct UPT_info* upt_info = reinterpret_cast<struct UPT_info*> (_UPT_create (tid));
if (!upt_info)
{
fprintf (stderr, "Failed to create upt info.\n");
fflush (stderr);
return 0;
}
unw_cursor_t cursor;
{
int error = unw_init_remote (&cursor, addr_space, upt_info);
if (error < 0)
{
fprintf (stderr, "unw_init_remote failed (%d)\n", error);
fflush (stderr);
return 0;
}
}
#endif
bool shouldContinue = false;
size_t numFrames = 0;
do
{
//
// Evaluate instruction pointer / program counter address.
//
#if UNWIND_REMOTE_SUPPORTED
uint64_t pc = 0;
{
unw_word_t unwound_pc;
int error = unw_get_reg (&cursor, UNW_REG_IP, &unwound_pc);
if (error < 0)
{
fprintf (stderr, "Failed to read IP (%d)\n", error);
fflush (stderr);
break;
}
pc = unwound_pc;
}
#if UNWIND_STACK_POINTER
uint64_t sp = 0;
{
unw_word_t unwound_sp;
int error = unw_get_reg (&cursor, UNW_REG_SP, &unwound_sp);
if (error < 0)
{
fprintf (stderr, "Failed to read SP (%d)\n", error);
fflush (stderr);
break;
}
sp = unwound_sp;
}
#endif
if (ignoreDepth == 0)
{
const char *function = "??";
#if UNWIND_FUNCTION_NAME
uintptr_t offset = 0;
char buffer [128];
unw_word_t value;
const int result = unw_get_proc_name_by_ip (addr_space, pc, buffer, sizeof (buffer), &value, upt_info);
if (result >= 0 && buffer [0] != '\0')
{
function = buffer;
offset = static_cast<uintptr_t>(value);
}
#endif
StackFrame frame;
frame.m_level = numFrames;
frame.m_pc = pc;
#if UNWIND_STACK_POINTER
frame.m_sp = sp;
#endif
strncpy (frame.m_function, function, sizeof (frame.m_function));
m_frames.push_back (frame);
numFrames++;
}
else
{
ignoreDepth--;
}
shouldContinue = (unw_step (&cursor) > 0);
#endif
}
while (shouldContinue && numFrames < maxDepth);
#if UNWIND_REMOTE_SUPPORTED
_UPT_destroy (upt_info);
#endif
#if UNWIND_MAP_SUPPORTED && UNWIND_FUNCTION_NAME
unw_map_cursor_destroy (&map_cursor);
unw_map_cursor_clear (&map_cursor);
#endif
return m_frames.size ();
}