From: He Zhe <zhe.he@windriver.com>
Date: Mon, 19 Apr 2021 09:16:57 +0000 (+0000)
Subject: lttng-probes: Warn of event's and provider's name for mismatch
X-Git-Tag: v2.13.0-rc1~9
X-Git-Url: https://git.lttng.org/?p=lttng-modules.git;a=commitdiff_plain;h=0c87bcc6c13ac8338860a1ae8fd03b1d66c4ace5

lttng-probes: Warn of event's and provider's name for mismatch

We have experience serveral cases of such mismatches. To make it easier to
debug, let's warn users of the event's and the provide's name.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I455bf92f9f735f890753c9103d22986e56e02e5d
---

diff --git a/src/lttng-probes.c b/src/lttng-probes.c
index aba7ada5..8cf1a75d 100644
--- a/src/lttng-probes.c
+++ b/src/lttng-probes.c
@@ -41,24 +41,31 @@ EXPORT_PER_CPU_SYMBOL_GPL(lttng_dynamic_len_stack);
 static
 int check_event_provider(struct lttng_kernel_probe_desc *desc)
 {
-	int i;
+	int i, mismatch = 0;
 	size_t provider_name_len;
 
 	provider_name_len = strnlen(desc->provider_name,
 				LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 	for (i = 0; i < desc->nr_events; i++) {
-		if (strncmp(desc->event_desc[i]->event_name,
-				desc->provider_name,
-				provider_name_len))
-			return 0;	/* provider mismatch */
 		/*
-		 * The event needs to contain at least provider name + _ +
+		 * The event name needs to start with provider name + _ +
 		 * one or more letter.
 		 */
-		if (strlen(desc->event_desc[i]->event_name) <= provider_name_len + 1)
-			return 0;	/* provider mismatch */
-		if (desc->event_desc[i]->event_name[provider_name_len] != '_')
-			return 0;	/* provider mismatch */
+		if (strncmp(desc->event_desc[i]->event_name, desc->provider_name, provider_name_len))
+			mismatch = 1;
+		else if (strlen(desc->event_desc[i]->event_name) <= provider_name_len + 1)
+			mismatch = 1;
+		else if (desc->event_desc[i]->event_name[provider_name_len] != '_')
+			mismatch = 1;
+
+		if (mismatch) {
+			printk(KERN_WARNING "LTTng: event provider mismatch: "
+				"The event name needs to start with provider "
+				"name + _ + one or more letter, "
+				"provider: %s, event name: %s\n",
+				desc->provider_name, desc->event_desc[i]->event_name);
+			return 0;
+		}
 	}
 	return 1;
 }