X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fmodprobe.c;h=b5b9d8cb793c2d6bbffc156d0ea8f6d314a4b0c7;hp=1a5a1b746cf4a67e38c8440035390e662e9dc713;hb=62e0422e48b9efd454c29c943ef4aefa6d49f242;hpb=bd69f856def413f9844618bbf04f689fc334fd19

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 1a5a1b746..b5b9d8cb7 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,
@@ -16,104 +17,128 @@
  */
 
 #define _GNU_SOURCE
+#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"
 
-/* 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-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" },
+	{ "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-btrfs", 0 },
-	{ "lttng-probe-compaction", 0 },
-	{ "lttng-probe-ext3", 0 },
-	{ "lttng-probe-ext4", 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-printk", 0 },
-	{ "lttng-probe-random", 0 },
-	{ "lttng-probe-rcu", 0 },
-	{ "lttng-probe-regmap", 0 },
-	{ "lttng-probe-regulator", 0 },
-	{ "lttng-probe-rpm", 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-sunrpc", 0 },
-	{ "lttng-probe-timer", 0 },
-	{ "lttng-probe-udp", 0 },
-	{ "lttng-probe-vmscan", 0 },
-	{ "lttng-probe-workqueue", 0 },
-	{ "lttng-probe-writeback", 0 },
+/* LTTng kernel tracer optional base modules list */
+struct kern_modules_param kern_modules_control_opt[] = {
+	{ "lttng-types" },
+	{ "lttng-ftrace" },
+	{ "lttng-kprobes" },
+	{ "lttng-kretprobes" },
 };
 
-/*
- * Remove control kernel module(s) in reverse load order.
- */
-void modprobe_remove_lttng_control(void)
+/* 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-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" },
+};
+
+/* dynamic probe modules list */
+static struct kern_modules_param *probes;
+static int nr_probes;
+static int probes_capacity;
+
+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_control) - 1; i >= 0; i--) {
+	for (i = entries - 1; i >= 0; i--) {
 		ret = snprintf(modprobe, sizeof(modprobe),
 				"/sbin/modprobe -r -q %s",
-				kern_modules_control[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_control[i].name);
-		} else if (kern_modules_control[i].required
-				&& WEXITSTATUS(ret) != 0) {
+					modules[i].name);
+		} else if (required && WEXITSTATUS(ret) != 0) {
 			ERR("Unable to remove module %s",
-					kern_modules_control[i].name);
+					modules[i].name);
 		} else {
 			DBG("Modprobe removal successful %s",
-					kern_modules_control[i].name);
+					modules[i].name);
 		}
 	}
+}
 
-error:
-	return;
+/*
+ * 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);
 }
 
 /*
@@ -121,34 +146,18 @@ error:
  */
 void modprobe_remove_lttng_data(void)
 {
-	int ret = 0, i;
-	char modprobe[256];
+	int i;
 
-	for (i = ARRAY_SIZE(kern_modules_list) - 1; i >= 0; i--) {
-		ret = snprintf(modprobe, sizeof(modprobe),
-				"/sbin/modprobe -r -q %s",
-				kern_modules_list[i].name);
-		if (ret < 0) {
-			PERROR("snprintf modprobe -r");
-			goto error;
-		}
-		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) {
-			ERR("Unable to remove module %s",
-					kern_modules_list[i].name);
-		} else {
-			DBG("Modprobe removal successful %s",
-					kern_modules_list[i].name);
+	if (probes) {
+		modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+
+		for (i = 0; i < nr_probes; ++i) {
+			free(probes[i].name);
 		}
-	}
 
-error:
-	return;
+		free(probes);
+		probes = NULL;
+	}
 }
 
 /*
@@ -160,55 +169,84 @@ void modprobe_remove_lttng_all(void)
 	modprobe_remove_lttng_control();
 }
 
-/*
- * Load control kernel module(s).
- */
-int modprobe_lttng_control(void)
+#if HAVE_KMOD
+#include <libkmod.h>
+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);
+}
+static int modprobe_lttng(struct kern_modules_param *modules,
+		int entries, int required)
 {
 	int ret = 0, i;
-	char modprobe[256];
+	struct kmod_ctx *ctx;
 
-	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);
+	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);
+
+	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("snprintf modprobe");
+			PERROR("Failed to create kmod module for %s", modules[i].name);
 			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);
+
+		ret = kmod_module_probe_insert_module(mod, KMOD_PROBE_IGNORE_LOADED,
+				NULL, NULL, NULL, NULL);
+		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",
-					kern_modules_control[i].name);
+			DBG("Modprobe successfully %s", modules[i].name);
 		}
+
+		kmod_module_unref(mod);
 	}
 
 error:
+	if (ctx) {
+		kmod_unref(ctx);
+	}
 	return ret;
 }
 
-/*
- * Load data kernel module(s).
- */
-int modprobe_lttng_data(void)
+#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 = 0; i < ARRAY_SIZE(kern_modules_list); i++) {
+	for (i = 0; i < entries; i++) {
 		ret = snprintf(modprobe, sizeof(modprobe),
 				"/sbin/modprobe %s%s",
-				kern_modules_list[i].required ? "" : "-q ",
-				kern_modules_list[i].name);
+				required ? "" : "-q ",
+				modules[i].name);
 		if (ret < 0) {
 			PERROR("snprintf modprobe");
 			goto error;
@@ -216,15 +254,27 @@ int modprobe_lttng_data(void)
 		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);
+			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",
-					kern_modules_list[i].name);
+			DBG("Modprobe successfully %s", modules[i].name);
 		}
 	}
 
@@ -232,23 +282,200 @@ error:
 	return ret;
 }
 
+#endif /* HAVE_KMOD */
+
 /*
- * Load all lttng kernel modules.
+ * Load control kernel module(s).
  */
-int modprobe_lttng_all(void)
+int modprobe_lttng_control(void)
 {
 	int ret;
 
-	ret = modprobe_lttng_control();
-	if (ret < 0) {
-		goto error;
+	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;
+}
+
+/**
+ * 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;
 	}
 
-	ret = modprobe_lttng_data();
-	if (ret < 0) {
-		goto error;
+	/* Double size. */
+	probes_capacity *= 2;
+
+	tmp_probes = zmalloc(sizeof(*tmp_probes) * probes_capacity);
+	if (!tmp_probes) {
+		PERROR("malloc probe list");
+		return -ENOMEM;
 	}
 
-error:
-	return ret;
+	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 index = nr_probes, ret;
+	char *tmp_list;
+
+	assert(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(tmp_list, ",");
+		if (!next) {
+			break;
+		}
+		tmp_list = NULL;
+
+		/* filter leading spaces */
+		while (*next == ' ') {
+			next++;
+		}
+
+		if (probes_capacity <= nr_probes) {
+			ret = grow_probes();
+			if (ret) {
+				return ret;
+			}
+		}
+
+		/* Length 13 is "lttng-probe-" + \0 */
+		name_len = strlen(next) + 13;
+
+		cur_mod = &probes[index];
+		cur_mod->name = zmalloc(name_len);
+		if (!cur_mod->name) {
+			PERROR("malloc probe list");
+			return -ENOMEM;
+		}
+
+		ret = snprintf(cur_mod->name, name_len, "lttng-probe-%s", next);
+		if (ret < 0) {
+			PERROR("snprintf modprobe name");
+			return -ENOMEM;
+		}
+
+		cur_mod++;
+		nr_probes++;
+	}
+
+	free(tmp_list);
+
+	return 0;
+}
+
+/*
+ * 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.
+	 */
+	if (kmod_probes_list) {
+		list = kmod_probes_list;
+	} else {
+		list = utils_get_kmod_probes_list();
+	}
+
+	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");
+				return -ENOMEM;
+			}
+
+			probes[i].name = name;
+		}
+	}
+
+	/*
+	 * Extra modules? Append them to current probes list.
+	 */
+	if (kmod_extra_probes_list) {
+		list = kmod_extra_probes_list;
+	} else {
+		list = utils_get_extra_kmod_probes_list();
+	}
+
+	if (list) {
+		ret = append_list_to_probes(list);
+		if (ret) {
+			return ret;
+		}
+	}
+
+	/*
+	 * Load probes modules now.
+	 */
+	return modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
 }