Fix: only unload successfully loaded kernel modules

[lttng-tools.git] / src / bin / lttng-sessiond / modprobe.c

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 3e41f5c1b6539a9eaa3af8706700c074c473c2b9..347829d5dbdd09c29bcd605e9b88e671be827394 100644 (file)
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -180,9 +180,12 @@ static int modprobe_lttng(struct kern_modules_param *modules,
                        goto error;
                }
 
-               ret = kmod_module_probe_insert_module(mod, KMOD_PROBE_IGNORE_LOADED,
+               ret = kmod_module_probe_insert_module(mod, 0,
                                NULL, NULL, NULL, NULL);
-               if (ret < 0) {
+               if (ret == -EEXIST) {
+                       DBG("Module %s is already loaded", modules[i].name);
+                       ret = 0;
+               } else if (ret < 0) {
                        if (required) {
                                ERR("Unable to load required module %s",
                                                modules[i].name);
@@ -194,6 +197,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
                        }
                } else {
                        DBG("Modprobe successfully %s", modules[i].name);
+                       modules[i].loaded = true;
                }
 
                kmod_module_unref(mod);
@@ -268,6 +272,10 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules,
        for (i = entries - 1; i >= 0; i--) {
                struct kmod_module *mod = NULL;
 
+               if (!modules[i].loaded) {
+                       continue;
+               }
+
                ret = kmod_module_new_from_name(ctx, modules[i].name, &mod);
                if (ret < 0) {
                        PERROR("Failed to create kmod module for %s", modules[i].name);
@@ -334,6 +342,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
                        }
                } else {
                        DBG("Modprobe successfully %s", modules[i].name);
+                       modules[i].loaded;
                }
        }
 
@@ -348,6 +357,9 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules,
        char modprobe[256];
 
        for (i = entries - 1; i >= 0; i--) {
+               if (!modules[i].loaded) {
+                       continue;
+               }
                ret = snprintf(modprobe, sizeof(modprobe),
                                "/sbin/modprobe -r -q %s",
                                modules[i].name);