[DTrace-devel] [PATCH v3 dtrace 1/4] dt_provider_tp: add optional event data, freed on tp free

[Alan Maguire]

It will be used to store suffixed function name for kprobe attach to
"foo.isra.0"-style functions.  Such functions use the unsuffixed form
as probe name, so we need to store the full function name to support
attach.

Signed-off-by: Alan Maguire <alan.maguire at oracle.com>
---
 libdtrace/dt_provider_tp.c | 27 +++++++++++++++++++++++++++
 libdtrace/dt_provider_tp.h |  8 ++++++++
 2 files changed, 35 insertions(+)

diff --git a/libdtrace/dt_provider_tp.c b/libdtrace/dt_provider_tp.c
index 50df2328..fc3c216a 100644
--- a/libdtrace/dt_provider_tp.c
+++ b/libdtrace/dt_provider_tp.c
@@ -33,6 +33,7 @@
 struct tp_probe {
 	uint32_t	event_id;	/* tracepoint event id or BTF id */
 	int		event_fd;	/* tracepoint perf event fd */
+	void		*event_data;	/* optional data */
 };
 
 /*
@@ -313,6 +314,8 @@ dt_tp_detach(dtrace_hdl_t *dtp, tp_probe_t *tpp)
 void
 dt_tp_destroy(dtrace_hdl_t *dtp, tp_probe_t *tpp)
 {
+	if (tpp && tpp->event_data)
+		free(tpp->event_data);
 	dt_free(dtp, tpp);
 }
 
@@ -334,6 +337,30 @@ dt_tp_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
 	return dt_probe_insert(dtp, prov, prv, mod, fun, prb, tpp);
 }
 
+dt_probe_t *
+dt_tp_probe_insert_data(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
+			const char *mod, const char *fun, const char *prb,
+			void *data)
+{
+	tp_probe_t	*tpp;
+
+	dt_probe_t *prp = dt_tp_probe_insert(dtp, prov, prv, mod, fun, prb);
+
+	if (prp) {
+		tpp = prp->prv_data;
+		tpp->event_data = data;
+	}
+	return prp;
+}
+
+void *
+dt_tp_get_event_data(const dt_probe_t *prp)
+{
+	tp_probe_t	*tpp = prp->prv_data;
+
+	return tpp->event_data;
+}
+
 uint32_t
 dt_tp_get_event_id(const dt_probe_t *prp)
 {
diff --git a/libdtrace/dt_provider_tp.h b/libdtrace/dt_provider_tp.h
index e7d52876..66a9bd80 100644
--- a/libdtrace/dt_provider_tp.h
+++ b/libdtrace/dt_provider_tp.h
@@ -41,6 +41,14 @@ extern struct dt_probe *dt_tp_probe_insert(dtrace_hdl_t *dtp,
 					   dt_provider_t *prov,
 					   const char *prv, const char *mod,
 					   const char *fun, const char *prb);
+extern struct dt_probe *dt_tp_probe_insert_data(dtrace_hdl_t *dtp,
+						dt_provider_t *prov,
+						const char *prv,
+						const char *mod,
+						const char *fun,
+						const char *prb,
+						void *data);
+extern void *dt_tp_get_event_data(const struct dt_probe *prp);
 extern uint32_t dt_tp_get_event_id(const struct dt_probe *prp);
 extern void dt_tp_set_event_id(const struct dt_probe *prp, uint32_t id);
 extern int dt_tp_probe_info(dtrace_hdl_t *dtp, FILE *f, int skip,
-- 
2.43.5