X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fmodprobe.c;h=75d6387c6fbe6b6c887d2117ee8c62ac6a242199;hp=8e5cc949ea7e067c14937f27ded70d06e8b0e7b5;hb=e6142f2e647e83238b1e399b1264e8adb05409f9;hpb=e3e57ea7c5b6379b0a2df41acbcacb731a6acdd9

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 8e5cc949e..75d6387c6 100644
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
+ *               2014 - Jan Glauber <jan.glauber@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2 only,
@@ -15,129 +16,411 @@
  * 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>
 
 #include <common/common.h>
+#include <common/utils.h>
 
 #include "modprobe.h"
 #include "kern-modules.h"
+#include "lttng-sessiond.h"
 
-/* MUST be loaded first */
-const struct kern_modules_param kern_modules_control[] = {
-	{ "lttng-tracer", 1 },
+#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-ring-buffer-client-discard" },
+	{ "lttng-ring-buffer-client-overwrite" },
+	{ "lttng-ring-buffer-metadata-client" },
+	{ "lttng-ring-buffer-client-mmap-discard" },
+	{ "lttng-ring-buffer-client-mmap-overwrite" },
+	{ "lttng-ring-buffer-metadata-mmap-client" },
 };
 
-/* LTTng kernel tracer modules list */
-const struct kern_modules_param kern_modules_list[] = {
-	{ "lttng-ftrace", 0 },
-	{ "lttng-kprobes", 0 },
-	{ "lttng-kretprobes", 0 },
-	{ "lttng-lib-ring-buffer", 1 },
-	{ "lttng-ring-buffer-client-discard", 1 },
-	{ "lttng-ring-buffer-client-overwrite", 1 },
-	{ "lttng-ring-buffer-metadata-client", 1 },
-	{ "lttng-ring-buffer-client-mmap-discard", 1 },
-	{ "lttng-ring-buffer-client-mmap-overwrite", 1 },
-	{ "lttng-ring-buffer-metadata-mmap-client", 1 },
-	{ "lttng-probe-lttng", 1 },
-	{ "lttng-types", 0 },
-	{ "lttng-probe-asoc", 0 },
-	{ "lttng-probe-block", 0 },
-	{ "lttng-probe-ext3", 0 },
-	{ "lttng-probe-gpio", 0 },
-	{ "lttng-probe-irq", 0 },
-	{ "lttng-probe-jbd", 0 },
-	{ "lttng-probe-jbd2", 0 },
-	{ "lttng-probe-kmem", 0 },
-	{ "lttng-probe-kvm", 0 },
-	{ "lttng-probe-lock", 0 },
-	{ "lttng-probe-module", 0 },
-	{ "lttng-probe-napi", 0 },
-	{ "lttng-probe-net", 0 },
-	{ "lttng-probe-power", 0 },
-	{ "lttng-probe-regulator", 0 },
-	{ "lttng-probe-sched", 0 },
-	{ "lttng-probe-scsi", 0 },
-	{ "lttng-probe-signal", 0 },
-	{ "lttng-probe-skb", 0 },
-	{ "lttng-probe-sock", 0 },
-	{ "lttng-probe-statedump", 0 },
-	{ "lttng-probe-timer", 0 },
-	{ "lttng-probe-udp", 0 },
-	{ "lttng-probe-vmscan", 0 },
+/* LTTng kernel tracer probe modules list */
+struct kern_modules_param kern_modules_probes_default[] = {
+	{ "lttng-probe-asoc" },
+	{ "lttng-probe-block" },
+	{ "lttng-probe-btrfs" },
+	{ "lttng-probe-compaction" },
+	{ "lttng-probe-ext3" },
+	{ "lttng-probe-ext4" },
+	{ "lttng-probe-gpio" },
+	{ "lttng-probe-i2c" },
+	{ "lttng-probe-irq" },
+	{ "lttng-probe-jbd" },
+	{ "lttng-probe-jbd2" },
+	{ "lttng-probe-kmem" },
+	{ "lttng-probe-kvm" },
+	{ "lttng-probe-kvm-x86" },
+	{ "lttng-probe-kvm-x86-mmu" },
+	{ "lttng-probe-lock" },
+	{ "lttng-probe-module" },
+	{ "lttng-probe-napi" },
+	{ "lttng-probe-net" },
+	{ "lttng-probe-power" },
+	{ "lttng-probe-printk" },
+	{ "lttng-probe-random" },
+	{ "lttng-probe-rcu" },
+	{ "lttng-probe-regmap" },
+	{ "lttng-probe-regulator" },
+	{ "lttng-probe-rpm" },
+	{ "lttng-probe-sched" },
+	{ "lttng-probe-scsi" },
+	{ "lttng-probe-signal" },
+	{ "lttng-probe-skb" },
+	{ "lttng-probe-sock" },
+	{ "lttng-probe-statedump" },
+	{ "lttng-probe-sunrpc" },
+	{ "lttng-probe-timer" },
+	{ "lttng-probe-udp" },
+	{ "lttng-probe-vmscan" },
+	{ "lttng-probe-v4l2" },
+	{ "lttng-probe-workqueue" },
+	{ "lttng-probe-writeback" },
+	{ "lttng-probe-x86-irq-vectors" },
+	{ "lttng-probe-x86-exceptions" },
 };
 
-/*
- * Remove control kernel module(s) in reverse load order.
+/* dynamic probe modules list */
+static struct kern_modules_param *probes;
+static int nr_probes;
+static int probes_capacity;
+
+#if HAVE_KMOD
+#include <libkmod.h>
+
+/**
+ * @brief Logging function for libkmod integration.
  */
-void modprobe_remove_lttng_control(void)
+static void log_kmod(void *data, int priority, const char *file, int line,
+		const char *fn, const char *format, va_list args)
+{
+	char *str;
+
+	if (vasprintf(&str, format, args) < 0) {
+		return;
+	}
+
+	DBG("libkmod: %s", str);
+	free(str);
+}
+
+/**
+ * @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;
+
+	*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);
+	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;
+
+		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 = kmod_module_probe_insert_module(mod, 0,
+				NULL, NULL, NULL, NULL);
+		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);
+	}
+
+error:
+	if (ctx) {
+		kmod_unref(ctx);
+	}
+	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,
+		int entries, int required)
 {
 	int ret = 0, i;
 	char modprobe[256];
 
-	for (i = ARRAY_SIZE(kern_modules_control) - 1; i >= 0; i--) {
+	for (i = 0; i < entries; i++) {
 		ret = snprintf(modprobe, sizeof(modprobe),
-				"/sbin/modprobe -r -q %s",
-				kern_modules_control[i].name);
+				"/sbin/modprobe %s%s",
+				required ? "" : "-q ",
+				modules[i].name);
 		if (ret < 0) {
-			PERROR("snprintf modprobe -r");
+			PERROR("snprintf modprobe");
 			goto error;
 		}
 		modprobe[sizeof(modprobe) - 1] = '\0';
 		ret = system(modprobe);
 		if (ret == -1) {
-			ERR("Unable to launch modprobe -r for module %s",
-					kern_modules_control[i].name);
-		} else if (kern_modules_control[i].required
-				&& WEXITSTATUS(ret) != 0) {
-			ERR("Unable to remove module %s",
-					kern_modules_control[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 removal successful %s",
-					kern_modules_control[i].name);
+			DBG("Modprobe successfully %s", modules[i].name);
+			modules[i].loaded = true;
 		}
 	}
 
 error:
-	return;
+	return ret;
 }
 
-/*
- * Remove data kernel modules in reverse load order.
- */
-void modprobe_remove_lttng_data(void)
+static void modprobe_remove_lttng(const struct kern_modules_param *modules,
+		int entries, int required)
 {
 	int ret = 0, i;
 	char modprobe[256];
 
-	for (i = ARRAY_SIZE(kern_modules_list) - 1; i >= 0; i--) {
+	for (i = entries - 1; i >= 0; i--) {
+		if (!modules[i].loaded) {
+			continue;
+		}
 		ret = snprintf(modprobe, sizeof(modprobe),
 				"/sbin/modprobe -r -q %s",
-				kern_modules_list[i].name);
+				modules[i].name);
 		if (ret < 0) {
 			PERROR("snprintf modprobe -r");
-			goto error;
+			return;
 		}
 		modprobe[sizeof(modprobe) - 1] = '\0';
 		ret = system(modprobe);
 		if (ret == -1) {
 			ERR("Unable to launch modprobe -r for module %s",
-					kern_modules_list[i].name);
-		} else if (kern_modules_list[i].required
-				&& WEXITSTATUS(ret) != 0) {
+					modules[i].name);
+		} else if (required && WEXITSTATUS(ret) != 0) {
 			ERR("Unable to remove module %s",
-					kern_modules_list[i].name);
+					modules[i].name);
 		} else {
 			DBG("Modprobe removal successful %s",
-					kern_modules_list[i].name);
+					modules[i].name);
 		}
 	}
+}
 
-error:
-	return;
+#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();
 }
 
 /*
@@ -154,90 +437,191 @@ void modprobe_remove_lttng_all(void)
  */
 int modprobe_lttng_control(void)
 {
-	int ret = 0, i;
-	char modprobe[256];
+	int ret;
 
-	for (i = 0; i < ARRAY_SIZE(kern_modules_control); i++) {
-		ret = snprintf(modprobe, sizeof(modprobe),
-				"/sbin/modprobe %s%s",
-				kern_modules_control[i].required ? "" : "-q ",
-				kern_modules_control[i].name);
-		if (ret < 0) {
-			PERROR("snprintf modprobe");
-			goto error;
-		}
-		modprobe[sizeof(modprobe) - 1] = '\0';
-		ret = system(modprobe);
-		if (ret == -1) {
-			ERR("Unable to launch modprobe for module %s",
-					kern_modules_control[i].name);
-		} else if (kern_modules_control[i].required
-				&& WEXITSTATUS(ret) != 0) {
-			ERR("Unable to load module %s",
-					kern_modules_control[i].name);
-		} else {
-			DBG("Modprobe successfully %s",
-					kern_modules_control[i].name);
+	ret = modprobe_lttng(kern_modules_control_core,
+			     ARRAY_SIZE(kern_modules_control_core),
+			     LTTNG_MOD_REQUIRED);
+	return ret;
+}
+
+/**
+ * Grow global list of probes (double capacity or set it to 1 if
+ * currently 0 and copy existing data).
+ */
+static int grow_probes(void)
+{
+	int i;
+	struct kern_modules_param *tmp_probes;
+
+	/* 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;
 	}
 
-error:
-	return ret;
+	/* 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 < 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;
 }
 
 /*
- * Load data kernel module(s).
+ * Appends a comma-separated list of probes to the global list
+ * of probes.
  */
-int modprobe_lttng_data(void)
+static int append_list_to_probes(const char *list)
 {
-	int ret = 0, i;
-	char modprobe[256];
+	char *next;
+	int ret;
+	char *tmp_list, *cur_list;
 
-	for (i = 0; i < ARRAY_SIZE(kern_modules_list); i++) {
-		ret = snprintf(modprobe, sizeof(modprobe),
-				"/sbin/modprobe %s%s",
-				kern_modules_list[i].required ? "" : "-q ",
-				kern_modules_list[i].name);
-		if (ret < 0) {
-			PERROR("snprintf modprobe");
+	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(cur_list, ",");
+		if (!next) {
+			break;
+		}
+		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;
+
+		cur_mod = &probes[nr_probes];
+		cur_mod->name = zmalloc(name_len);
+		if (!cur_mod->name) {
+			PERROR("malloc probe list");
+			ret = -ENOMEM;
 			goto error;
 		}
-		modprobe[sizeof(modprobe) - 1] = '\0';
-		ret = system(modprobe);
-		if (ret == -1) {
-			ERR("Unable to launch modprobe for module %s",
-					kern_modules_list[i].name);
-		} else if (kern_modules_list[i].required
-				&& WEXITSTATUS(ret) != 0) {
-			ERR("Unable to load module %s",
-					kern_modules_list[i].name);
-		} else {
-			DBG("Modprobe successfully %s",
-					kern_modules_list[i].name);
+
+		ret = snprintf(cur_mod->name, name_len, "lttng-probe-%s", next);
+		if (ret < 0) {
+			PERROR("snprintf modprobe name");
+			ret = -ENOMEM;
+			goto error;
 		}
+
+		nr_probes++;
 	}
 
+	free(tmp_list);
+	return 0;
+
 error:
+	free(tmp_list);
+	free_probes();
 	return ret;
 }
 
 /*
- * Load all lttng kernel modules.
+ * Load data kernel module(s).
  */
-int modprobe_lttng_all(void)
+int modprobe_lttng_data(void)
 {
-	int ret;
+	int ret, i;
+	char *list;
 
-	ret = modprobe_lttng_control();
-	if (ret < 0) {
-		goto error;
+	/*
+	 * 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;
+		}
 	}
 
-	ret = modprobe_lttng_data();
-	if (ret < 0) {
+	/*
+	 * 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;
+		}
+	}
+
+	/*
+	 * Load probes modules now.
+	 */
+	ret = modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+	if (ret) {
 		goto error;
 	}
+	return ret;
 
 error:
+	free_probes();
 	return ret;
 }