X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fmodprobe.c;h=75d6387c6fbe6b6c887d2117ee8c62ac6a242199;hp=968b2650e05c9685fc04b3e56e29bb5fb87cd1ae;hb=e6142f2e647e83238b1e399b1264e8adb05409f9;hpb=234170acd2ca985ff9023007eef52440601d8f12

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 968b2650e..75d6387c6 100644
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -16,7 +16,15 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+/**
+ * @file modprobe.c
+ *
+ * @brief modprobe related functions.
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/wait.h>
@@ -26,14 +34,13 @@
 
 #include "modprobe.h"
 #include "kern-modules.h"
+#include "lttng-sessiond.h"
 
 #define LTTNG_MOD_REQUIRED	1
 #define LTTNG_MOD_OPTIONAL	0
 
 /* LTTng kernel tracer mandatory core modules list */
 struct kern_modules_param kern_modules_control_core[] = {
-	{ "lttng-tracer" },	/* MUST be loaded first so keep at top */
-	{ "lttng-lib-ring-buffer" },
 	{ "lttng-ring-buffer-client-discard" },
 	{ "lttng-ring-buffer-client-overwrite" },
 	{ "lttng-ring-buffer-metadata-client" },
@@ -42,14 +49,6 @@ struct kern_modules_param kern_modules_control_core[] = {
 	{ "lttng-ring-buffer-metadata-mmap-client" },
 };
 
-/* LTTng kernel tracer optional base modules list */
-struct kern_modules_param kern_modules_control_opt[] = {
-	{ "lttng-types" },
-	{ "lttng-ftrace" },
-	{ "lttng-kprobes" },
-	{ "lttng-kretprobes" },
-};
-
 /* LTTng kernel tracer probe modules list */
 struct kern_modules_param kern_modules_probes_default[] = {
 	{ "lttng-probe-asoc" },
@@ -59,6 +58,7 @@ struct kern_modules_param kern_modules_probes_default[] = {
 	{ "lttng-probe-ext3" },
 	{ "lttng-probe-ext4" },
 	{ "lttng-probe-gpio" },
+	{ "lttng-probe-i2c" },
 	{ "lttng-probe-irq" },
 	{ "lttng-probe-jbd" },
 	{ "lttng-probe-jbd2" },
@@ -90,82 +90,21 @@ struct kern_modules_param kern_modules_probes_default[] = {
 	{ "lttng-probe-v4l2" },
 	{ "lttng-probe-workqueue" },
 	{ "lttng-probe-writeback" },
+	{ "lttng-probe-x86-irq-vectors" },
+	{ "lttng-probe-x86-exceptions" },
 };
 
 /* dynamic probe modules list */
 static struct kern_modules_param *probes;
 static int nr_probes;
-
-void modprobe_remove_lttng(const struct kern_modules_param *modules,
-			   int entries, int required)
-{
-	int ret = 0, i;
-	char modprobe[256];
-
-	for (i = entries - 1; i >= 0; i--) {
-		ret = snprintf(modprobe, sizeof(modprobe),
-				"/sbin/modprobe -r -q %s",
-				modules[i].name);
-		if (ret < 0) {
-			PERROR("snprintf modprobe -r");
-			return;
-		}
-		modprobe[sizeof(modprobe) - 1] = '\0';
-		ret = system(modprobe);
-		if (ret == -1) {
-			ERR("Unable to launch modprobe -r for module %s",
-					modules[i].name);
-		} else if (required && WEXITSTATUS(ret) != 0) {
-			ERR("Unable to remove module %s",
-					modules[i].name);
-		} else {
-			DBG("Modprobe removal successful %s",
-					modules[i].name);
-		}
-		if (probes)
-			free(probes[i].name);
-	}
-}
-
-/*
- * Remove control kernel module(s) in reverse load order.
- */
-void modprobe_remove_lttng_control(void)
-{
-	modprobe_remove_lttng(kern_modules_control_opt,
-			      ARRAY_SIZE(kern_modules_control_opt),
-			      LTTNG_MOD_OPTIONAL);
-	modprobe_remove_lttng(kern_modules_control_core,
-			      ARRAY_SIZE(kern_modules_control_core),
-			      LTTNG_MOD_REQUIRED);
-}
-
-/*
- * Remove data kernel modules in reverse load order.
- */
-void modprobe_remove_lttng_data(void)
-{
-	if (probes) {
-		modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
-		free(probes);
-		probes = NULL;
-	} else
-		modprobe_remove_lttng(kern_modules_probes_default,
-				      ARRAY_SIZE(kern_modules_probes_default),
-				      LTTNG_MOD_OPTIONAL);
-}
-
-/*
- * Remove all kernel modules in reverse order.
- */
-void modprobe_remove_lttng_all(void)
-{
-	modprobe_remove_lttng_data();
-	modprobe_remove_lttng_control();
-}
+static int probes_capacity;
 
 #if HAVE_KMOD
 #include <libkmod.h>
+
+/**
+ * @brief Logging function for libkmod integration.
+ */
 static void log_kmod(void *data, int priority, const char *file, int line,
 		const char *fn, const char *format, va_list args)
 {
@@ -178,21 +117,61 @@ static void log_kmod(void *data, int priority, const char *file, int line,
 	DBG("libkmod: %s", str);
 	free(str);
 }
-static int modprobe_lttng(struct kern_modules_param *modules,
-		int entries, int required)
+
+/**
+ * @brief Setup the libkmod context.
+ *
+ * Create the context, add a custom logging function and preload the
+ * ressources for faster operation.
+ *
+ * @returns	\c 0 on success
+ * 		\c < 0 on error
+ */
+static int setup_kmod_ctx(struct kmod_ctx **ctx)
 {
-	int ret = 0, i;
-	struct kmod_ctx *ctx;
+	int ret = 0;
 
-	ctx = kmod_new(NULL, NULL);
+	*ctx = kmod_new(NULL, NULL);
 	if (!ctx) {
 		PERROR("Unable to create kmod library context");
 		ret = -ENOMEM;
 		goto error;
 	}
 
-	kmod_set_log_fn(ctx, log_kmod, NULL);
-	kmod_load_resources(ctx);
+	kmod_set_log_fn(*ctx, log_kmod, NULL);
+	ret = kmod_load_resources(*ctx);
+	if (ret < 0) {
+		ERR("Failed to load kmod library resources");
+		goto error;
+	}
+
+error:
+	return ret;
+}
+
+/**
+ * @brief Loads the kernel modules in \p modules
+ *
+ * @param modules	List of modules to load
+ * @param entries	Number of modules in the list
+ * @param required	Are the modules required or optionnal
+ *
+ * If the modules are required, we will return with error after the
+ * first failed module load, otherwise we continue loading.
+ *
+ * @returns		\c 0 on success
+ * 			\c < 0 on error
+ */
+static int modprobe_lttng(struct kern_modules_param *modules,
+		int entries, int required)
+{
+	int ret = 0, i;
+	struct kmod_ctx *ctx;
+
+	ret = setup_kmod_ctx(&ctx);
+	if (ret < 0) {
+		goto error;
+	}
 
 	for (i = 0; i < entries; i++) {
 		struct kmod_module *mod = NULL;
@@ -203,12 +182,24 @@ 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 (required && ret < 0) {
-			ERR("Unable to load module %s", modules[i].name);
+		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);
+				goto error;
+			} else {
+				DBG("Unable to load optional module %s; continuing",
+						modules[i].name);
+				ret = 0;
+			}
 		} else {
 			DBG("Modprobe successfully %s", modules[i].name);
+			modules[i].loaded = true;
 		}
 
 		kmod_module_unref(mod);
@@ -221,6 +212,97 @@ error:
 	return ret;
 }
 
+/**
+ * @brief Recursively unload modules.
+ *
+ * This function implements the same modules unloading behavior as
+ * 'modprobe -r' or rmmod, it will recursevily go trought the \p module
+ * dependencies and unload modules with a refcount of 0.
+ *
+ * @param mod		The module to unload
+ *
+ * @returns		\c 0 on success
+ * 			\c < 0 on error
+ */
+static int rmmod_recurse(struct kmod_module *mod) {
+	int ret = 0;
+	struct kmod_list *deps, *itr;
+
+	if (kmod_module_get_initstate(mod) == KMOD_MODULE_BUILTIN) {
+		DBG("Module %s is builtin", kmod_module_get_name(mod));
+		return ret;
+	}
+
+	ret = kmod_module_remove_module(mod, 0);
+
+	deps = kmod_module_get_dependencies(mod);
+	if (deps != NULL) {
+		kmod_list_foreach(itr, deps) {
+			struct kmod_module *dep = kmod_module_get_module(itr);
+			if (kmod_module_get_refcnt(dep) == 0) {
+				DBG("Recursive remove module %s",
+						kmod_module_get_name(dep));
+				rmmod_recurse(dep);
+			}
+			kmod_module_unref(dep);
+		}
+		kmod_module_unref_list(deps);
+	}
+
+	return ret;
+}
+
+/**
+ * @brief Unloads the kernel modules in \p modules
+ *
+ * @param modules	List of modules to unload
+ * @param entries	Number of modules in the list
+ * @param required	Are the modules required or optionnal
+ *
+ */
+static void modprobe_remove_lttng(const struct kern_modules_param *modules,
+		int entries, int required)
+{
+	int ret = 0, i;
+	struct kmod_ctx *ctx;
+
+	ret = setup_kmod_ctx(&ctx);
+	if (ret < 0) {
+		goto error;
+	}
+
+	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);
+			goto error;
+		}
+
+		ret = rmmod_recurse(mod);
+		if (ret == -EEXIST) {
+			DBG("Module %s is not in kernel.", modules[i].name);
+		} else if (required && ret < 0) {
+			ERR("Unable to remove module %s", modules[i].name);
+		} else {
+			DBG("Modprobe removal successful %s",
+				modules[i].name);
+		}
+
+		kmod_module_unref(mod);
+	}
+
+error:
+	if (ctx) {
+		kmod_unref(ctx);
+	}
+}
+
 #else /* HAVE_KMOD */
 
 static int modprobe_lttng(struct kern_modules_param *modules,
@@ -241,12 +323,28 @@ static int modprobe_lttng(struct kern_modules_param *modules,
 		modprobe[sizeof(modprobe) - 1] = '\0';
 		ret = system(modprobe);
 		if (ret == -1) {
-			ERR("Unable to launch modprobe for module %s",
-					modules[i].name);
-		} else if (required && WEXITSTATUS(ret) != 0) {
-			ERR("Unable to load module %s", modules[i].name);
+			if (required) {
+				ERR("Unable to launch modprobe for required module %s",
+						modules[i].name);
+				goto error;
+			} else {
+				DBG("Unable to launch modprobe for optional module %s; continuing",
+						modules[i].name);
+				ret = 0;
+			}
+		} else if (WEXITSTATUS(ret) != 0) {
+			if (required) {
+				ERR("Unable to load required module %s",
+						modules[i].name);
+				goto error;
+			} else {
+				DBG("Unable to load optional module %s; continuing",
+						modules[i].name);
+				ret = 0;
+			}
 		} else {
 			DBG("Modprobe successfully %s", modules[i].name);
+			modules[i].loaded = true;
 		}
 	}
 
@@ -254,8 +352,86 @@ error:
 	return ret;
 }
 
+static void modprobe_remove_lttng(const struct kern_modules_param *modules,
+		int entries, int required)
+{
+	int ret = 0, i;
+	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);
+		if (ret < 0) {
+			PERROR("snprintf modprobe -r");
+			return;
+		}
+		modprobe[sizeof(modprobe) - 1] = '\0';
+		ret = system(modprobe);
+		if (ret == -1) {
+			ERR("Unable to launch modprobe -r for module %s",
+					modules[i].name);
+		} else if (required && WEXITSTATUS(ret) != 0) {
+			ERR("Unable to remove module %s",
+					modules[i].name);
+		} else {
+			DBG("Modprobe removal successful %s",
+					modules[i].name);
+		}
+	}
+}
+
 #endif /* HAVE_KMOD */
 
+/*
+ * Remove control kernel module(s) in reverse load order.
+ */
+void modprobe_remove_lttng_control(void)
+{
+	modprobe_remove_lttng(kern_modules_control_core,
+			      ARRAY_SIZE(kern_modules_control_core),
+			      LTTNG_MOD_REQUIRED);
+}
+
+static void free_probes(void)
+{
+	int i;
+
+	if (!probes) {
+		return;
+	}
+	for (i = 0; i < nr_probes; ++i) {
+		free(probes[i].name);
+	}
+	free(probes);
+	probes = NULL;
+	nr_probes = 0;
+}
+
+/*
+ * Remove data kernel modules in reverse load order.
+ */
+void modprobe_remove_lttng_data(void)
+{
+	if (!probes) {
+		return;
+	}
+	modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+	free_probes();
+}
+
+/*
+ * Remove all kernel modules in reverse order.
+ */
+void modprobe_remove_lttng_all(void)
+{
+	modprobe_remove_lttng_data();
+	modprobe_remove_lttng_control();
+}
+
 /*
  * Load control kernel module(s).
  */
@@ -266,80 +442,186 @@ int modprobe_lttng_control(void)
 	ret = modprobe_lttng(kern_modules_control_core,
 			     ARRAY_SIZE(kern_modules_control_core),
 			     LTTNG_MOD_REQUIRED);
-	if (ret != 0)
-		return ret;
-	ret = modprobe_lttng(kern_modules_control_opt,
-			     ARRAY_SIZE(kern_modules_control_opt),
-			     LTTNG_MOD_OPTIONAL);
 	return ret;
 }
 
-/*
- * Load data kernel module(s).
+/**
+ * Grow global list of probes (double capacity or set it to 1 if
+ * currently 0 and copy existing data).
  */
-int modprobe_lttng_data(void)
+static int grow_probes(void)
 {
-	int i, ret;
-	int entries = ARRAY_SIZE(kern_modules_probes_default);
-	char *list, *next;
+	int i;
+	struct kern_modules_param *tmp_probes;
 
-	/*
-	 * First take command line option, if not available take environment
-	 * variable.
-	 */
-	if (kmod_probes_list) {
-		list = kmod_probes_list;
-	} else {
-		list = utils_get_kmod_probes_list();
-	}
-	/* The default is to load ALL probes */
-	if (!list) {
-		return modprobe_lttng(kern_modules_probes_default, entries,
-				LTTNG_MOD_OPTIONAL);
+	/* Initialize capacity to 1 if 0. */
+	if (probes_capacity == 0) {
+		probes = zmalloc(sizeof(*probes));
+		if (!probes) {
+			PERROR("malloc probe list");
+			return -ENOMEM;
+		}
+
+		probes_capacity = 1;
+		return 0;
 	}
 
-	/*
-	 * A probe list is available, so use it.
-	 * The number of probes is limited by the number of probes in the
-	 * default list.
-	 */
-	probes = zmalloc(sizeof(struct kern_modules_param *) * entries);
-	if (!probes) {
+	/* Double size. */
+	probes_capacity *= 2;
+
+	tmp_probes = zmalloc(sizeof(*tmp_probes) * probes_capacity);
+	if (!tmp_probes) {
 		PERROR("malloc probe list");
 		return -ENOMEM;
 	}
 
-	for (i = 0; i < entries; i++) {
+	for (i = 0; i < nr_probes; ++i) {
+		/* Move name pointer. */
+		tmp_probes[i].name = probes[i].name;
+	}
+
+	/* Replace probes with larger copy. */
+	free(probes);
+	probes = tmp_probes;
+
+	return 0;
+}
+
+/*
+ * Appends a comma-separated list of probes to the global list
+ * of probes.
+ */
+static int append_list_to_probes(const char *list)
+{
+	char *next;
+	int ret;
+	char *tmp_list, *cur_list;
+
+	assert(list);
+
+	cur_list = tmp_list = strdup(list);
+	if (!tmp_list) {
+		PERROR("strdup temp list");
+		return -ENOMEM;
+	}
+
+	for (;;) {
 		size_t name_len;
+		struct kern_modules_param *cur_mod;
 
-		next = strtok(list, ",");
+		next = strtok(cur_list, ",");
 		if (!next) {
-			goto out;
+			break;
 		}
-		list = NULL;
+		cur_list = NULL;
 
 		/* filter leading spaces */
 		while (*next == ' ') {
 			next++;
 		}
 
+		if (probes_capacity <= nr_probes) {
+			ret = grow_probes();
+			if (ret) {
+				goto error;
+			}
+		}
+
 		/* Length 13 is "lttng-probe-" + \0 */
 		name_len = strlen(next) + 13;
 
-		probes[i].name = zmalloc(name_len);
-		if (!probes[i].name) {
+		cur_mod = &probes[nr_probes];
+		cur_mod->name = zmalloc(name_len);
+		if (!cur_mod->name) {
 			PERROR("malloc probe list");
-			return -ENOMEM;
+			ret = -ENOMEM;
+			goto error;
 		}
 
-		ret = snprintf(probes[i].name, name_len, "lttng-probe-%s", next);
+		ret = snprintf(cur_mod->name, name_len, "lttng-probe-%s", next);
 		if (ret < 0) {
 			PERROR("snprintf modprobe name");
-			goto out;
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		nr_probes++;
+	}
+
+	free(tmp_list);
+	return 0;
+
+error:
+	free(tmp_list);
+	free_probes();
+	return ret;
+}
+
+/*
+ * Load data kernel module(s).
+ */
+int modprobe_lttng_data(void)
+{
+	int ret, i;
+	char *list;
+
+	/*
+	 * Base probes: either from command line option, environment
+	 * variable or default list.
+	 */
+	list = config.kmod_probes_list.value;
+	if (list) {
+		/* User-specified probes. */
+		ret = append_list_to_probes(list);
+		if (ret) {
+			return ret;
+		}
+	} else {
+		/* Default probes. */
+		int def_len = ARRAY_SIZE(kern_modules_probes_default);
+
+		probes = zmalloc(sizeof(*probes) * def_len);
+		if (!probes) {
+			PERROR("malloc probe list");
+			return -ENOMEM;
+		}
+
+		nr_probes = probes_capacity = def_len;
+
+		for (i = 0; i < def_len; ++i) {
+			char* name = strdup(kern_modules_probes_default[i].name);
+
+			if (!name) {
+				PERROR("strdup probe item");
+				ret = -ENOMEM;
+				goto error;
+			}
+
+			probes[i].name = name;
+		}
+	}
+
+	/*
+	 * Extra modules? Append them to current probes list.
+	 */
+	list = config.kmod_extra_probes_list.value;
+	if (list) {
+		ret = append_list_to_probes(list);
+		if (ret) {
+			goto error;
 		}
 	}
 
-out:
-	nr_probes = i;
-	return modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+	/*
+	 * Load probes modules now.
+	 */
+	ret = modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+	if (ret) {
+		goto error;
+	}
+	return ret;
+
+error:
+	free_probes();
+	return ret;
 }