@@ -2234,11 +2234,54 @@ PyObject *PyDynevent_probe(PyDynevent *self)
return dynevent_info2py(buff, type);
}
+PyObject *PyDynevent_register(PyDynevent *self)
+{
+ if (tracefs_dynevent_create(self->ptrObj) < 0) {
+ char *evt;
+ int type;
+
+ type = tracefs_dynevent_info(self->ptrObj, NULL, &evt, NULL, NULL, NULL);
+ TfsError_fmt(NULL, "Failed to register dynamic event '%s'.",
+ type != TRACEFS_DYNEVENT_UNKNOWN ? evt : "UNKNOWN");
+ free(evt);
+ return NULL;
+ }
+
+ /*
+ * Here the dynamic event gets added to the system.
+ * Hence we need to 'destroy' this event at exit.
+ */
+ set_destroy_flag((PyObject *)self, true);
+ Py_RETURN_NONE;
+}
+
+PyObject *PyDynevent_unregister(PyDynevent *self)
+{
+ if (tracefs_dynevent_destroy(self->ptrObj, true) < 0) {
+ char *evt;
+ int type;
+
+ type = tracefs_dynevent_info(self->ptrObj, NULL, &evt, NULL, NULL, NULL);
+ TfsError_fmt(NULL, "Failed to unregister dynamic event '%s'.",
+ type != TRACEFS_DYNEVENT_UNKNOWN ? evt : "UNKNOWN");
+ free(evt);
+ return NULL;
+ }
+
+ /*
+ * Here the synthetic event gets removed from the system.
+ * Hence we no loger need to 'destroy' this event at exit.
+ */
+ set_destroy_flag((PyObject *)self, false);
+ Py_RETURN_NONE;
+}
+
PyObject *PyFtrace_kprobe(PyObject *self, PyObject *args, PyObject *kwargs)
{
static char *kwlist[] = {"event", "function", "probe", NULL};
const char *event, *function, *probe;
struct tracefs_dynevent *kprobe;
+ PyObject *py_dyn;
if (!PyArg_ParseTupleAndKeywords(args,
kwargs,
@@ -2256,13 +2299,14 @@ PyObject *PyFtrace_kprobe(PyObject *self, PyObject *args, PyObject *kwargs)
return NULL;
}
- if (tracefs_dynevent_create(kprobe) < 0) {
- TfsError_fmt(NULL, "Failed to create kprobe '%s'", event);
- tracefs_dynevent_free(kprobe);
- return NULL;
- }
-
- return PyDynevent_New(kprobe);
+ py_dyn = PyDynevent_New(kprobe);
+ /*
+ * Here we only allocated and initializes a dynamic event object.
+ * However, no dynamic event is added to the system yet. Hence,
+ * there is no need to 'destroy' this event at exit.
+ */
+ set_destroy_flag(py_dyn, false);
+ return py_dyn;
}
PyObject *PyFtrace_kretprobe(PyObject *self, PyObject *args, PyObject *kwargs)
@@ -2270,6 +2314,7 @@ PyObject *PyFtrace_kretprobe(PyObject *self, PyObject *args, PyObject *kwargs)
static char *kwlist[] = {"event", "function", "probe", NULL};
const char *event, *function, *probe = "$retval";
struct tracefs_dynevent *kprobe;
+ PyObject *py_dyn;
if (!PyArg_ParseTupleAndKeywords(args,
kwargs,
@@ -2287,13 +2332,14 @@ PyObject *PyFtrace_kretprobe(PyObject *self, PyObject *args, PyObject *kwargs)
return NULL;
}
- if (tracefs_dynevent_create(kprobe) < 0) {
- TfsError_fmt(NULL, "Failed to create kretprobe '%s'", event);
- tracefs_dynevent_free(kprobe);
- return NULL;
- }
-
- return PyDynevent_New(kprobe);
+ py_dyn = PyDynevent_New(kprobe);
+ /*
+ * Here we only allocated and initializes a dynamic event object.
+ * However, no dynamic event is added to the system yet. Hence,
+ * there is no need to 'destroy' this event at exit.
+ */
+ set_destroy_flag(py_dyn, false);
+ return py_dyn;
}
struct tep_event *dynevent_get_event(PyDynevent *event,
@@ -2323,6 +2369,7 @@ PyObject *PyFtrace_eprobe(PyObject *self, PyObject *args, PyObject *kwargs)
static char *kwlist[] = {"event", "target_system", "target_event", "fetchargs", NULL};
const char *event, *target_system, *target_event, *fetchargs;
struct tracefs_dynevent *eprobe;
+ PyObject *py_dyn;
if (!PyArg_ParseTupleAndKeywords(args,
kwargs,
@@ -2341,13 +2388,14 @@ PyObject *PyFtrace_eprobe(PyObject *self, PyObject *args, PyObject *kwargs)
return NULL;
}
- if (tracefs_dynevent_create(eprobe) < 0) {
- TfsError_fmt(NULL, "Failed to create eprobe '%s'", event);
- tracefs_dynevent_free(eprobe);
- return NULL;
- }
-
- return PyDynevent_New(eprobe);
+ py_dyn = PyDynevent_New(eprobe);
+ /*
+ * Here we only allocated and initializes a dynamic event object.
+ * However, no dynamic event is added to the system yet. Hence,
+ * there is no need to 'destroy' this event at exit.
+ */
+ set_destroy_flag(py_dyn, false);
+ return py_dyn;;
}
static PyObject *set_filter(PyObject *args, PyObject *kwargs,
@@ -76,6 +76,10 @@ PyObject *PyDynevent_address(PyDynevent *self);
PyObject *PyDynevent_probe(PyDynevent *self);
+PyObject *PyDynevent_register(PyDynevent *self);
+
+PyObject *PyDynevent_unregister(PyDynevent *self);
+
PyObject *PyDynevent_set_filter(PyDynevent *self, PyObject *args,
PyObject *kwargs);
@@ -127,6 +127,16 @@ static PyMethodDef PyDynevent_methods[] = {
METH_NOARGS,
"Get the event definition."
},
+ {"register",
+ (PyCFunction) PyDynevent_register,
+ METH_NOARGS,
+ "Register dynamic event."
+ },
+ {"unregister",
+ (PyCFunction) PyDynevent_unregister,
+ METH_NOARGS,
+ "Unregister dynamic event."
+ },
{"set_filter",
(PyCFunction) PyDynevent_set_filter,
METH_VARARGS | METH_KEYWORDS,
@@ -164,6 +174,7 @@ static int dynevent_destroy(struct tracefs_dynevent *devt)
{
return tracefs_dynevent_destroy(devt, true);
}
+
C_OBJECT_WRAPPER(tracefs_dynevent, PyDynevent,
dynevent_destroy,
tracefs_dynevent_free)
@@ -255,12 +266,12 @@ static PyMethodDef PySynthEvent_methods[] = {
{"register",
(PyCFunction) PySynthEvent_register,
METH_NOARGS,
- "Register synth. event to a trace instance."
+ "Register synth. event."
},
{"unregister",
(PyCFunction) PySynthEvent_unregister,
METH_NOARGS,
- "Unregister synth. event from a trace instance."
+ "Unregister synth. event."
},
{"enable",
(PyCFunction) PySynthEvent_enable,
@@ -157,6 +157,7 @@ class kprobe(kprobe_base):
probe = ' '.join('{!s}={!s}'.format(key,val) for (key, val) in self.fields.items())
self.kp = ft.kprobe(event=self.name, function=self.func, probe=probe);
+ self.kp.register();
self.evt_id = find_event_id(system=ft.tc_event_system(), event=self.name)
@@ -187,6 +188,7 @@ class kretval_probe(kprobe_base):
""" Register this probe to Ftrace.
"""
self.kp = ft.kprobe(event=self.name, function=self.func);
+ self.kp.register();
self.evt_id = find_event_id(system=ft.tc_event_system(), event=self.name)
@@ -414,11 +414,13 @@ class KprobeTestCase(unittest.TestCase):
evt2_prove = 'file=+u0($arg2):ustring'
kp1 = ft.kprobe(event=evt1, function=evt1_func, probe=evt1_prove)
+ kp1.register()
self.assertEqual(evt1, kp1.event())
self.assertEqual(evt1_func, kp1.address())
self.assertEqual(evt1_prove, kp1.probe())
kp2 = ft.kprobe(event=evt2, function=evt2_func, probe=evt2_prove)
+ kp2.register()
self.assertEqual(evt2, kp2.event())
self.assertEqual(evt2_func, kp2.address())
self.assertEqual(evt2_prove, kp2.probe())
@@ -430,6 +432,7 @@ class KprobeTestCase(unittest.TestCase):
flt = 'path~\'/sys/fs/cgroup/*\''
kp1 = ft.kprobe(event=evt1, function=evt1_func, probe=evt1_prove)
+ kp1.register()
inst = ft.create_instance(instance_name)
kp1.set_filter(instance=inst, filter=flt)
@@ -445,6 +448,7 @@ class KprobeTestCase(unittest.TestCase):
evt1_prove = 'path=+u0($arg2):ustring'
kp1 = ft.kprobe(event=evt1, function=evt1_func, probe=evt1_prove)
+ kp1.register()
inst = ft.create_instance(instance_name)
kp1.enable(instance=inst)
ret = kp1.is_enabled(instance=inst)
@@ -458,8 +462,6 @@ class EprobeTestCase(unittest.TestCase):
def test_eprobe(self):
""" Event probes are introduced in Linux kernel 5.15
"""
- if kernel_version < (5, 15):
- return
evt1 = 'sopen_in'
evt1_tsys = 'syscalls'
@@ -495,6 +497,7 @@ class EprobeTestCase(unittest.TestCase):
ep1 = ft.eprobe(event=evt1, target_system=evt1_tsys, target_event=evt1_tevent,
fetchargs=evt1_args)
+ ep1.register()
inst = ft.create_instance(instance_name)
ep1.enable(instance=inst)
ret = ep1.is_enabled(instance=inst)
Currently the allocation of the Python object and the registration of the new dynamic event are both done in the corresponding constructor for kprobe, kretprobe or eprobe. Originally, this was done with the idea to simplify the usage, however it turns that this can be an issue in the case when these events are used in conjuction with synthetic events. In such a case, the order in which the events are registered cannot be arbitrary, because of the intrinsic dependencies between those events. And the order used to create the events must be reverced when destroying them. However, this requirement collides with way the Python automatic garbage collection works, where the objects are destroyed in the same order of there creation. The problem gets solved by decoupling the allocation of the Python objects from the registration of the corresponding events on the system. With this, we can create the objects in one order and register in another. Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com> --- src/ftracepy-utils.c | 90 ++++++++++++++----- src/ftracepy-utils.h | 4 + src/ftracepy.c | 15 +++- tracecruncher/ft_utils.py | 2 + .../tests/1_unit/test_01_ftracepy_unit.py | 7 +- 5 files changed, 93 insertions(+), 25 deletions(-)