X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-probes.c;h=862b19e7c47e3c7c5b5e262e5b1bc02edf3c090f;hb=2c05c691a10f3130f9339a15369140ad6ca70f85;hp=f028ccab8cadd967971cb3f673b883f622b03f7e;hpb=5f733922ed1e2db5b397292ede81303a9e538a08;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-probes.c b/liblttng-ust/lttng-probes.c
index f028ccab..862b19e7 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>
@@ -147,32 +148,50 @@ struct cds_list_head *lttng_get_probe_list_head(void)
 }
 
 static
-const struct lttng_probe_desc *find_provider(const char *provider)
+int check_provider_version(struct lttng_probe_desc *desc)
 {
-	struct lttng_probe_desc *iter;
-	struct cds_list_head *probe_list;
-
-	probe_list = lttng_get_probe_list_head();
-	cds_list_for_each_entry(iter, probe_list, head) {
-		if (!strcmp(iter->provider, provider))
-			return iter;
+	/*
+	 * 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 */
 	}
-	return NULL;
 }
 
+
 int lttng_probe_register(struct lttng_probe_desc *desc)
 {
 	int ret = 0;
 
-	ust_lock();
+	lttng_ust_fixup_tls();
 
 	/*
-	 * Check if the provider has already been registered.
+	 * If version mismatch, don't register, but don't trigger assert
+	 * on caller. The version check just prints an error.
 	 */
-	if (find_provider(desc->provider)) {
-		ret = -EEXIST;
-		goto end;
-	}
+	if (!check_provider_version(desc))
+		return 0;
+
+	ust_lock_nocheck();
+
 	cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
 	desc->lazy = 1;
 	DBG("adding probe %s containing %u events to lazy registration list",
@@ -184,7 +203,7 @@ int lttng_probe_register(struct lttng_probe_desc *desc)
 	 */
 	if (lttng_session_active())
 		fixup_lazy_probes();
-end:
+
 	ust_unlock();
 	return ret;
 }
@@ -197,12 +216,20 @@ 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
 		cds_list_del(&desc->lazy_init_head);
-	DBG("just unregistered probe %s", desc->provider);
+
+	lttng_probe_provider_unregister_events(desc);
+	DBG("just unregistered probes of provider %s", desc->provider);
+
 	ust_unlock();
 }