X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-probes.c;h=390265add0d22feb4936ac09962aa05a9c342434;hb=c7667bfebfa1d054ad8d54fd98ada3c86184e327;hp=b1d5fe28558433209f70460119125ca81b433793;hpb=6715d7d1c61b3ffdae9d50aa8875c627900a857f;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-probes.c b/liblttng-ust/lttng-probes.c
index b1d5fe28..390265ad 100644
--- a/liblttng-ust/lttng-probes.c
+++ b/liblttng-ust/lttng-probes.c
@@ -20,6 +20,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
 #include <string.h>
 #include <errno.h>
 #include <urcu/list.h>
@@ -80,7 +81,6 @@ void lttng_lazy_probe_register(struct lttng_probe_desc *desc)
 {
 	struct lttng_probe_desc *iter;
 	struct cds_list_head *probe_list;
-	int i;
 
 	/*
 	 * Each provider enforce that every event name begins with the
@@ -114,19 +114,6 @@ void lttng_lazy_probe_register(struct lttng_probe_desc *desc)
 desc_added:
 	DBG("just registered probe %s containing %u events",
 		desc->provider, desc->nr_events);
-	/*
-	 * fix the events awaiting probe load.
-	 */
-	for (i = 0; i < desc->nr_events; i++) {
-		const struct lttng_event_desc *ed;
-		int ret;
-
-		ed = desc->event_desc[i];
-		DBG("Registered event probe \"%s\" with signature \"%s\"",
-			ed->name, ed->signature);
-		ret = lttng_fix_pending_event_desc(ed);
-		assert(!ret);
-	}
 }
 
 /*
@@ -136,6 +123,7 @@ static
 void fixup_lazy_probes(void)
 {
 	struct lttng_probe_desc *iter, *tmp;
+	int ret;
 
 	lazy_nesting++;
 	cds_list_for_each_entry_safe(iter, tmp,
@@ -144,6 +132,8 @@ void fixup_lazy_probes(void)
 		iter->lazy = 0;
 		cds_list_del(&iter->lazy_init_head);
 	}
+	ret = lttng_fix_pending_events();
+	assert(!ret);
 	lazy_nesting--;
 }
 
@@ -171,11 +161,50 @@ const struct lttng_probe_desc *find_provider(const char *provider)
 	return NULL;
 }
 
+static
+int check_provider_version(struct lttng_probe_desc *desc)
+{
+	/*
+	 * Check tracepoint provider version compatibility.
+	 */
+	if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
+		DBG("Provider \"%s\" accepted, version %u.%u is compatible "
+			"with LTTng UST provider version %u.%u.",
+			desc->provider, desc->major, desc->minor,
+			LTTNG_UST_PROVIDER_MAJOR,
+			LTTNG_UST_PROVIDER_MINOR);
+		if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
+			DBG("However, some LTTng UST features might not be "
+				"available for this provider unless it is "
+				"recompiled against a more recent LTTng UST.");
+		}
+		return 1;		/* accept */
+	} else {
+		ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
+			"with LTTng UST provider version %u.%u. Please upgrade "
+			"LTTng UST.",
+			desc->provider, desc->major, desc->minor,
+			LTTNG_UST_PROVIDER_MAJOR,
+			LTTNG_UST_PROVIDER_MINOR);
+		return 0;		/* reject */
+	}
+}
+
+
 int lttng_probe_register(struct lttng_probe_desc *desc)
 {
 	int ret = 0;
 
-	ust_lock();
+	lttng_ust_fixup_tls();
+
+	/*
+	 * If version mismatch, don't register, but don't trigger assert
+	 * on caller. The version check just prints an error.
+	 */
+	if (!check_provider_version(desc))
+		return 0;
+
+	ust_lock_nocheck();
 
 	/*
 	 * Check if the provider has already been registered.
@@ -208,7 +237,12 @@ int ltt_probe_register(struct lttng_probe_desc *desc)
 
 void lttng_probe_unregister(struct lttng_probe_desc *desc)
 {
-	ust_lock();
+	lttng_ust_fixup_tls();
+
+	if (!check_provider_version(desc))
+		return;
+
+	ust_lock_nocheck();
 	if (!desc->lazy)
 		cds_list_del(&desc->head);
 	else