X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-probes.c;h=bba5cd345238b25db0340c77c52ae991584a30a9;hb=6c2125aff1c8d8217072931ee6223be80112dcb2;hp=f028ccab8cadd967971cb3f673b883f622b03f7e;hpb=5f733922ed1e2db5b397292ede81303a9e538a08;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-probes.c b/liblttng-ust/lttng-probes.c
index f028ccab..bba5cd34 100644
--- a/liblttng-ust/lttng-probes.c
+++ b/liblttng-ust/lttng-probes.c
@@ -160,11 +160,48 @@ 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();
+	/*
+	 * 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.
@@ -197,7 +234,10 @@ int ltt_probe_register(struct lttng_probe_desc *desc)
 
 void lttng_probe_unregister(struct lttng_probe_desc *desc)
 {
-	ust_lock();
+	if (!check_provider_version(desc))
+		return;
+
+	ust_lock_nocheck();
 	if (!desc->lazy)
 		cds_list_del(&desc->head);
 	else