[PATCH v2 1/2] trace-cruncher: Add support for event probes

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Event probe (eprobe) is a new type of ftrace dynamic events, introduced
in the Linux kernel 5.15 version. It is useful to have support for it in
trace-cruncher, as it allows more flexibility when printing event's
data.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 src/ftracepy-utils.c | 32 ++++++++++++++++++++++++++++++++
 src/ftracepy-utils.h |  2 ++
 src/ftracepy.c       |  5 +++++
 3 files changed, 39 insertions(+)

diff --git a/src/ftracepy-utils.c b/src/ftracepy-utils.c
index 8c46590..053b659 100644
--- a/src/ftracepy-utils.c
+++ b/src/ftracepy-utils.c
@@ -2315,6 +2315,38 @@ struct tep_event *dynevent_get_event(PyDynevent *event,
 	return tep_evt;
 }
 
+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;
+
+	if (!PyArg_ParseTupleAndKeywords(args,
+					 kwargs,
+					 "ssss",
+					 kwlist,
+					 &event,
+					 &target_system,
+					 &target_event,
+					 &fetchargs)) {
+		return NULL;
+	}
+
+	eprobe = tracefs_eprobe_alloc(TC_SYS, event, target_system, target_event, fetchargs);
+	if (!eprobe) {
+		MEM_ERROR;
+		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);
+}
+
 static PyObject *set_filter(PyObject *args, PyObject *kwargs,
 			    struct tep_handle *tep,
 			    struct tep_event *event)
diff --git a/src/ftracepy-utils.h b/src/ftracepy-utils.h
index 7612df6..c96fd85 100644
--- a/src/ftracepy-utils.h
+++ b/src/ftracepy-utils.h
@@ -251,6 +251,8 @@ PyObject *PyFtrace_register_kprobe(PyObject *self, PyObject *args,
 PyObject *PyFtrace_register_kretprobe(PyObject *self, PyObject *args,
 						      PyObject *kwargs);
 
+PyObject *PyFtrace_eprobe(PyObject *self, PyObject *args, PyObject *kwargs);
+
 PyObject *PyFtrace_hist(PyObject *self, PyObject *args,
 					PyObject *kwargs);
 
diff --git a/src/ftracepy.c b/src/ftracepy.c
index 3f71b5e..0c9f795 100644
--- a/src/ftracepy.c
+++ b/src/ftracepy.c
@@ -460,6 +460,11 @@ static PyMethodDef ftracepy_methods[] = {
 	 METH_VARARGS | METH_KEYWORDS,
 	 "Define a kretprobe."
 	},
+	{"register_eprobe",
+	 (PyCFunction) PyFtrace_eprobe,
+	 METH_VARARGS | METH_KEYWORDS,
+	 "Define an eprobe."
+	},
 	{"hist",
 	 (PyCFunction) PyFtrace_hist,
 	 METH_VARARGS | METH_KEYWORDS,
-- 
2.34.1