Fix: tracepoint name remapping

Commit

  "Introduce API to remap event names exposed by LTTng"

failed to map the event names enabled by the user to tracepoint names
known to the kernel. For instance, tracing with the kmem_kmalloc event
enabled is not gathering any event. This issue applies to all tracepoint
events declared with a different name within LTTng than within the Linux
kernel.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/lttng-events.c b/lttng-events.c
index c1b3b44d4af7be7270e98929fb72688eab3073df..5b3416ab559ccc85b8ab58c12544dfa6d2b23513 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -400,7 +400,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                        ret = -ENOENT;
                        goto register_error;
                }
-               ret = kabi_2635_tracepoint_probe_register(event_param->name,
+               ret = kabi_2635_tracepoint_probe_register(event->desc->kname,
                                event->desc->probe_callback,
                                event);
                if (ret) {

diff --git a/lttng-events.h b/lttng-events.h
index bc5cd9f5271b2b088decd100788cc7edf2e9ddeb..cf31b2e1017f97579446071d4e5816fc8b67ab0c 100644 (file)
--- a/lttng-events.h
+++ b/lttng-events.h
@@ -169,7 +169,8 @@ struct lttng_ctx {
 };
 
 struct lttng_event_desc {
-       const char *name;
+       const char *name;               /* lttng-modules name */
+       const char *kname;              /* Linux kernel name (tracepoints) */
        void *probe_callback;
        const struct lttng_event_ctx *ctx;      /* context */
        const struct lttng_event_field *fields; /* event payload */

diff --git a/probes/lttng-events.h b/probes/lttng-events.h
index bf2e2b9d1df5364cc3213fc70345c38f21d7fd5a..680f466f9a2b40531e3214ef551d7296bf024ba1 100644 (file)
--- a/probes/lttng-events.h
+++ b/probes/lttng-events.h
@@ -327,6 +327,7 @@ static void __event_probe__##_name(void *__data);
 static const struct lttng_event_desc __event_desc___##_map = {         \
        .fields = __event_fields___##_template,                         \
        .name = #_map,                                                  \
+       .kname = #_name,                                                \
        .probe_callback = (void *) TP_PROBE_CB(_template),              \
        .nr_fields = ARRAY_SIZE(__event_fields___##_template),          \
        .owner = THIS_MODULE,                                           \