From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 3 Feb 2021 15:21:42 +0000 (-0500)
Subject: Fix: use MT-safe strtok_r in multithreaded context
X-Git-Tag: v2.12.3~6
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=0d2ff68f1830682b13e903690d6410262dad201e;p=lttng-tools.git

Fix: use MT-safe strtok_r in multithreaded context

append_list_to_probes uses the non-multithread-safe "strtok" while in
multithreaded context.

It is called by modprobe_lttng_data(), which is called from
init_kernel_tracer().

init_kernel_tracer is used from main() after other threads are created,
and also from process_client_msg() when a user attempts to interact with
the kernel domain if the kernel tracer has not yet been successfully
initialized.

Fixed by using the MT-safe strtok_r() instead.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic3f81551b8508451e0f9733c5de56a4d4407b813
---

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index cf9c12b3c..81e32bed9 100644
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -486,7 +486,7 @@ static int append_list_to_probes(const char *list)
 {
 	char *next;
 	int ret;
-	char *tmp_list, *cur_list;
+	char *tmp_list, *cur_list, *saveptr;
 
 	assert(list);
 
@@ -500,7 +500,7 @@ static int append_list_to_probes(const char *list)
 		size_t name_len;
 		struct kern_modules_param *cur_mod;
 
-		next = strtok(cur_list, ",");
+		next = strtok_r(cur_list, ",", &saveptr);
 		if (!next) {
 			break;
 		}