cpython/Python/legacy_tracing.c

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/* Support for legacy tracing on top of PEP 669 instrumentation
* Provides callables to forward PEP 669 events to legacy events.
*/
#include "Python.h"
#include "pycore_ceval.h" // export _PyEval_SetProfile()
#include "pycore_object.h"
#include "pycore_sysmodule.h" // _PySys_Audit()
#include "opcode.h"
#include <stddef.h>
typedef struct _PyLegacyEventHandler {
PyObject_HEAD
vectorcallfunc vectorcall;
int event;
} _PyLegacyEventHandler;
#ifdef Py_GIL_DISABLED
#define LOCK_SETUP() PyMutex_Lock(&_PyRuntime.ceval.sys_trace_profile_mutex);
#define UNLOCK_SETUP() PyMutex_Unlock(&_PyRuntime.ceval.sys_trace_profile_mutex);
#else
#define LOCK_SETUP()
#define UNLOCK_SETUP()
#endif
/* The Py_tracefunc function expects the following arguments:
* obj: the trace object (PyObject *)
* frame: the current frame (PyFrameObject *)
* kind: the kind of event, see PyTrace_XXX #defines (int)
* arg: The arg (a PyObject *)
*/
static PyObject *
call_profile_func(_PyLegacyEventHandler *self, PyObject *arg)
{
PyThreadState *tstate = _PyThreadState_GET();
if (tstate->c_profilefunc == NULL) {
Py_RETURN_NONE;
}
PyFrameObject *frame = PyEval_GetFrame();
if (frame == NULL) {
PyErr_SetString(PyExc_SystemError,
"Missing frame when calling profile function.");
return NULL;
}
Py_INCREF(frame);
int err = tstate->c_profilefunc(tstate->c_profileobj, frame, self->event, arg);
Py_DECREF(frame);
if (err) {
return NULL;
}
Py_RETURN_NONE;
}
static PyObject *
sys_profile_start(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 2);
return call_profile_func(self, Py_None);
}
static PyObject *
sys_profile_throw(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_profile_func(self, Py_None);
}
static PyObject *
sys_profile_return(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_profile_func(self, args[2]);
}
static PyObject *
sys_profile_unwind(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_profile_func(self, NULL);
}
static PyObject *
sys_profile_call_or_return(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 4);
PyObject *callable = args[2];
if (PyCFunction_Check(callable)) {
return call_profile_func(self, callable);
}
if (Py_TYPE(callable) == &PyMethodDescr_Type) {
PyObject *self_arg = args[3];
/* For backwards compatibility need to
* convert to builtin method */
/* If no arg, skip */
if (self_arg == &_PyInstrumentation_MISSING) {
Py_RETURN_NONE;
}
PyObject *meth = Py_TYPE(callable)->tp_descr_get(
callable, self_arg, (PyObject*)Py_TYPE(self_arg));
if (meth == NULL) {
return NULL;
}
PyObject *res = call_profile_func(self, meth);
Py_DECREF(meth);
return res;
}
Py_RETURN_NONE;
}
int
_PyEval_SetOpcodeTrace(
PyFrameObject *frame,
bool enable
) {
assert(frame != NULL);
assert(PyCode_Check(frame->f_frame->f_executable));
PyCodeObject *code = (PyCodeObject *)frame->f_frame->f_executable;
_PyMonitoringEventSet events = 0;
if (_PyMonitoring_GetLocalEvents(code, PY_MONITORING_SYS_TRACE_ID, &events) < 0) {
return -1;
}
if (enable) {
if (events & (1 << PY_MONITORING_EVENT_INSTRUCTION)) {
return 0;
}
events |= (1 << PY_MONITORING_EVENT_INSTRUCTION);
} else {
if (!(events & (1 << PY_MONITORING_EVENT_INSTRUCTION))) {
return 0;
}
events &= (~(1 << PY_MONITORING_EVENT_INSTRUCTION));
}
return _PyMonitoring_SetLocalEvents(code, PY_MONITORING_SYS_TRACE_ID, events);
}
static PyObject *
call_trace_func(_PyLegacyEventHandler *self, PyObject *arg)
{
PyThreadState *tstate = _PyThreadState_GET();
if (tstate->c_tracefunc == NULL) {
Py_RETURN_NONE;
}
PyFrameObject *frame = PyEval_GetFrame();
if (frame == NULL) {
PyErr_SetString(PyExc_SystemError,
"Missing frame when calling trace function.");
return NULL;
}
if (frame->f_trace_opcodes) {
if (_PyEval_SetOpcodeTrace(frame, true) != 0) {
return NULL;
}
}
Py_INCREF(frame);
int err = tstate->c_tracefunc(tstate->c_traceobj, frame, self->event, arg);
frame->f_lineno = 0;
Py_DECREF(frame);
if (err) {
return NULL;
}
Py_RETURN_NONE;
}
static PyObject *
sys_trace_exception_func(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
PyObject *exc = args[2];
assert(PyExceptionInstance_Check(exc));
PyObject *type = (PyObject *)Py_TYPE(exc);
PyObject *tb = PyException_GetTraceback(exc);
if (tb == NULL) {
tb = Py_NewRef(Py_None);
}
PyObject *tuple = PyTuple_Pack(3, type, exc, tb);
Py_DECREF(tb);
if (tuple == NULL) {
return NULL;
}
PyObject *res = call_trace_func(self, tuple);
Py_DECREF(tuple);
return res;
}
static PyObject *
sys_trace_start(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 2);
return call_trace_func(self, Py_None);
}
static PyObject *
sys_trace_throw(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_trace_func(self, Py_None);
}
static PyObject *
sys_trace_unwind(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_trace_func(self, NULL);
}
static PyObject *
sys_trace_return(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(!PyErr_Occurred());
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
assert(PyCode_Check(args[0]));
PyObject *val = args[2];
PyObject *res = call_trace_func(self, val);
return res;
}
static PyObject *
sys_trace_yield(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 3);
return call_trace_func(self, args[2]);
}
static PyObject *
sys_trace_instruction_func(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
assert(PyVectorcall_NARGS(nargsf) == 2);
PyFrameObject *frame = PyEval_GetFrame();
if (frame == NULL) {
PyErr_SetString(PyExc_SystemError,
"Missing frame when calling trace function.");
return NULL;
}
PyThreadState *tstate = _PyThreadState_GET();
if (!tstate->c_tracefunc || !frame->f_trace_opcodes) {
if (_PyEval_SetOpcodeTrace(frame, false) != 0) {
return NULL;
}
Py_RETURN_NONE;
}
Py_INCREF(frame);
int err = tstate->c_tracefunc(tstate->c_traceobj, frame, self->event, Py_None);
frame->f_lineno = 0;
Py_DECREF(frame);
if (err) {
return NULL;
}
Py_RETURN_NONE;
}
static PyObject *
trace_line(
PyThreadState *tstate, _PyLegacyEventHandler *self,
PyFrameObject *frame, int line
) {
if (!frame->f_trace_lines) {
Py_RETURN_NONE;
}
if (line < 0) {
Py_RETURN_NONE;
}
Py_INCREF(frame);
frame->f_lineno = line;
int err = tstate->c_tracefunc(tstate->c_traceobj, frame, self->event, Py_None);
frame->f_lineno = 0;
Py_DECREF(frame);
if (err) {
return NULL;
}
Py_RETURN_NONE;
}
static PyObject *
sys_trace_line_func(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
PyThreadState *tstate = _PyThreadState_GET();
if (tstate->c_tracefunc == NULL) {
Py_RETURN_NONE;
}
assert(PyVectorcall_NARGS(nargsf) == 2);
int line = PyLong_AsInt(args[1]);
assert(line >= 0);
PyFrameObject *frame = PyEval_GetFrame();
if (frame == NULL) {
PyErr_SetString(PyExc_SystemError,
"Missing frame when calling trace function.");
return NULL;
}
assert(args[0] == (PyObject *)_PyFrame_GetCode(frame->f_frame));
return trace_line(tstate, self, frame, line);
}
/* sys.settrace generates line events for all backward
* edges, even if on the same line.
* Handle that case here */
static PyObject *
sys_trace_jump_func(
_PyLegacyEventHandler *self, PyObject *const *args,
size_t nargsf, PyObject *kwnames
) {
assert(kwnames == NULL);
PyThreadState *tstate = _PyThreadState_GET();
if (tstate->c_tracefunc == NULL) {
Py_RETURN_NONE;
}
assert(PyVectorcall_NARGS(nargsf) == 3);
int from = PyLong_AsInt(args[1])/sizeof(_Py_CODEUNIT);
assert(from >= 0);
int to = PyLong_AsInt(args[2])/sizeof(_Py_CODEUNIT);
assert(to >= 0);
if (to > from) {
/* Forward jump */
return &_PyInstrumentation_DISABLE;
}
PyCodeObject *code = (PyCodeObject *)args[0];
assert(PyCode_Check(code));
/* We can call _Py_Instrumentation_GetLine because we always set
* line events for tracing */
int to_line = _Py_Instrumentation_GetLine(code, to);
int from_line = _Py_Instrumentation_GetLine(code, from);
if (to_line != from_line) {
/* Will be handled by target INSTRUMENTED_LINE */
return &_PyInstrumentation_DISABLE;
}
PyFrameObject *frame = PyEval_GetFrame();
if (frame == NULL) {
PyErr_SetString(PyExc_SystemError,
"Missing frame when calling trace function.");
return NULL;
}
if (!frame->f_trace_lines) {
Py_RETURN_NONE;
}
return trace_line(tstate, self, frame, to_line);
}
PyTypeObject _PyLegacyEventHandler_Type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"sys.legacy_event_handler",
sizeof(_PyLegacyEventHandler),
.tp_dealloc = (destructor)PyObject_Free,
.tp_vectorcall_offset = offsetof(_PyLegacyEventHandler, vectorcall),
.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
Py_TPFLAGS_HAVE_VECTORCALL | Py_TPFLAGS_DISALLOW_INSTANTIATION,
.tp_call = PyVectorcall_Call,
};
static int
set_callbacks(int tool, vectorcallfunc vectorcall, int legacy_event, int event1, int event2)
{
_PyLegacyEventHandler *callback =
PyObject_NEW(_PyLegacyEventHandler, &_PyLegacyEventHandler_Type);
if (callback == NULL) {
return -1;
}
callback->vectorcall = vectorcall;
callback->event = legacy_event;
Py_XDECREF(_PyMonitoring_RegisterCallback(tool, event1, (PyObject *)callback));
if (event2 >= 0) {
Py_XDECREF(_PyMonitoring_RegisterCallback(tool, event2, (PyObject *)callback));
}
Py_DECREF(callback);
return 0;
}
#ifndef NDEBUG
/* Ensure that tstate is valid: sanity check for PyEval_AcquireThread() and
PyEval_RestoreThread(). Detect if tstate memory was freed. It can happen
when a thread continues to run after Python finalization, especially
daemon threads. */
static int
is_tstate_valid(PyThreadState *tstate)
{
assert(!_PyMem_IsPtrFreed(tstate));
assert(!_PyMem_IsPtrFreed(tstate->interp));
return 1;
}
#endif
static Py_ssize_t
setup_profile(PyThreadState *tstate, Py_tracefunc func, PyObject *arg, PyObject **old_profileobj)
{
*old_profileobj = NULL;
/* Setup PEP 669 monitoring callbacks and events. */
if (!tstate->interp->sys_profile_initialized) {
tstate->interp->sys_profile_initialized = true;
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_start, PyTrace_CALL,
PY_MONITORING_EVENT_PY_START, PY_MONITORING_EVENT_PY_RESUME)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_throw, PyTrace_CALL,
PY_MONITORING_EVENT_PY_THROW, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_return, PyTrace_RETURN,
PY_MONITORING_EVENT_PY_RETURN, PY_MONITORING_EVENT_PY_YIELD)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_unwind, PyTrace_RETURN,
PY_MONITORING_EVENT_PY_UNWIND, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_call_or_return, PyTrace_C_CALL,
PY_MONITORING_EVENT_CALL, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_call_or_return, PyTrace_C_RETURN,
PY_MONITORING_EVENT_C_RETURN, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_PROFILE_ID,
(vectorcallfunc)sys_profile_call_or_return, PyTrace_C_EXCEPTION,
PY_MONITORING_EVENT_C_RAISE, -1)) {
return -1;
}
}
int delta = (func != NULL) - (tstate->c_profilefunc != NULL);
tstate->c_profilefunc = func;
*old_profileobj = tstate->c_profileobj;
tstate->c_profileobj = Py_XNewRef(arg);
tstate->interp->sys_profiling_threads += delta;
assert(tstate->interp->sys_profiling_threads >= 0);
return tstate->interp->sys_profiling_threads;
}
int
_PyEval_SetProfile(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
{
assert(is_tstate_valid(tstate));
/* The caller must hold the GIL */
assert(PyGILState_Check());
/* Call _PySys_Audit() in the context of the current thread state,
even if tstate is not the current thread state. */
PyThreadState *current_tstate = _PyThreadState_GET();
if (_PySys_Audit(current_tstate, "sys.setprofile", NULL) < 0) {
return -1;
}
// needs to be decref'd outside of the lock
PyObject *old_profileobj;
LOCK_SETUP();
Py_ssize_t profiling_threads = setup_profile(tstate, func, arg, &old_profileobj);
UNLOCK_SETUP();
Py_XDECREF(old_profileobj);
uint32_t events = 0;
if (profiling_threads) {
events =
(1 << PY_MONITORING_EVENT_PY_START) | (1 << PY_MONITORING_EVENT_PY_RESUME) |
(1 << PY_MONITORING_EVENT_PY_RETURN) | (1 << PY_MONITORING_EVENT_PY_YIELD) |
(1 << PY_MONITORING_EVENT_CALL) | (1 << PY_MONITORING_EVENT_PY_UNWIND) |
(1 << PY_MONITORING_EVENT_PY_THROW);
}
return _PyMonitoring_SetEvents(PY_MONITORING_SYS_PROFILE_ID, events);
}
static Py_ssize_t
setup_tracing(PyThreadState *tstate, Py_tracefunc func, PyObject *arg, PyObject **old_traceobj)
{
*old_traceobj = NULL;
/* Setup PEP 669 monitoring callbacks and events. */
if (!tstate->interp->sys_trace_initialized) {
tstate->interp->sys_trace_initialized = true;
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_start, PyTrace_CALL,
PY_MONITORING_EVENT_PY_START, PY_MONITORING_EVENT_PY_RESUME)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_throw, PyTrace_CALL,
PY_MONITORING_EVENT_PY_THROW, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_return, PyTrace_RETURN,
PY_MONITORING_EVENT_PY_RETURN, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_yield, PyTrace_RETURN,
PY_MONITORING_EVENT_PY_YIELD, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_exception_func, PyTrace_EXCEPTION,
PY_MONITORING_EVENT_RAISE, PY_MONITORING_EVENT_STOP_ITERATION)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_line_func, PyTrace_LINE,
PY_MONITORING_EVENT_LINE, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_unwind, PyTrace_RETURN,
PY_MONITORING_EVENT_PY_UNWIND, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_jump_func, PyTrace_LINE,
PY_MONITORING_EVENT_JUMP, -1)) {
return -1;
}
if (set_callbacks(PY_MONITORING_SYS_TRACE_ID,
(vectorcallfunc)sys_trace_instruction_func, PyTrace_OPCODE,
PY_MONITORING_EVENT_INSTRUCTION, -1)) {
return -1;
}
}
int delta = (func != NULL) - (tstate->c_tracefunc != NULL);
tstate->c_tracefunc = func;
*old_traceobj = tstate->c_traceobj;
tstate->c_traceobj = Py_XNewRef(arg);
tstate->interp->sys_tracing_threads += delta;
assert(tstate->interp->sys_tracing_threads >= 0);
return tstate->interp->sys_tracing_threads;
}
int
_PyEval_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
{
assert(is_tstate_valid(tstate));
/* The caller must hold the GIL */
assert(PyGILState_Check());
/* Call _PySys_Audit() in the context of the current thread state,
even if tstate is not the current thread state. */
PyThreadState *current_tstate = _PyThreadState_GET();
if (_PySys_Audit(current_tstate, "sys.settrace", NULL) < 0) {
return -1;
}
assert(tstate->interp->sys_tracing_threads >= 0);
// needs to be decref'd outside of the lock
PyObject *old_traceobj;
LOCK_SETUP();
Py_ssize_t tracing_threads = setup_tracing(tstate, func, arg, &old_traceobj);
UNLOCK_SETUP();
Py_XDECREF(old_traceobj);
if (tracing_threads < 0) {
return -1;
}
uint32_t events = 0;
if (tracing_threads) {
events =
(1 << PY_MONITORING_EVENT_PY_START) | (1 << PY_MONITORING_EVENT_PY_RESUME) |
(1 << PY_MONITORING_EVENT_PY_RETURN) | (1 << PY_MONITORING_EVENT_PY_YIELD) |
(1 << PY_MONITORING_EVENT_RAISE) | (1 << PY_MONITORING_EVENT_LINE) |
(1 << PY_MONITORING_EVENT_JUMP) |
(1 << PY_MONITORING_EVENT_PY_UNWIND) | (1 << PY_MONITORING_EVENT_PY_THROW) |
(1 << PY_MONITORING_EVENT_STOP_ITERATION);
PyFrameObject* frame = PyEval_GetFrame();
if (frame->f_trace_opcodes) {
int ret = _PyEval_SetOpcodeTrace(frame, true);
if (ret != 0) {
return ret;
}
}
}
return _PyMonitoring_SetEvents(PY_MONITORING_SYS_TRACE_ID, events);
}