X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fmodprobe.c;h=e1f52afd972b48aab29df0a6ac9a9d33f7b47c19;hp=90fec711b8120c740d0ac4d48239b68c7db097c4;hb=adfe4f5ee4088878b68135a4bd64e7260f2330ba;hpb=866c17cef5ab4305d0087cf2823e92f0057904c0

diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 90fec711b..e1f52afd9 100644
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -1,19 +1,16 @@
 /*
- * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
- *               2014 - Jan Glauber <jan.glauber@gmail.com>
+ * Copyright (C) 2011 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 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,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ */
+
+/**
+ * @file modprobe.c
+ *
+ * @brief modprobe related functions.
  *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -27,62 +24,206 @@
 
 #include "modprobe.h"
 #include "kern-modules.h"
-
-#define LTTNG_MOD_REQUIRED	1
-#define LTTNG_MOD_OPTIONAL	0
+#include "lttng-sessiond.h"
 
 /* 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" },
+	{
+		.name = (char *) "lttng-ring-buffer-client-discard",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
+	{
+		.name = (char *) "lttng-ring-buffer-client-overwrite",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
+	{
+		.name = (char *) "lttng-ring-buffer-metadata-client",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
+	{
+		.name = (char *) "lttng-ring-buffer-client-mmap-discard",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
+	{
+		.name = (char *) "lttng-ring-buffer-client-mmap-overwrite",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
+	{
+		.name = (char *) "lttng-ring-buffer-metadata-mmap-client",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED,
+	},
 };
 
-/* LTTng kernel tracer probe modules list */
+/* LTTng kerneltracer 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" },
-	{ "lttng-probe-x86-irq-vectors" },
-	{ "lttng-probe-x86-exceptions" },
+	{
+		.name = (char *) "lttng-probe-asoc",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-block",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-btrfs",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-compaction",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-ext3",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-ext4",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-gpio",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-i2c",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-irq",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-jbd",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-jbd2",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-kmem",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-kvm",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-kvm-x86",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-kvm-x86-mmu",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-lock",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-module",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-napi",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-net",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-power",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-preemptirq",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-printk",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-random",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-rcu",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-regmap",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-regulator",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-rpm",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-sched",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-scsi",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-signal",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-skb",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-sock",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-statedump",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-sunrpc",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-timer",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-udp",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-vmscan",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-v4l2",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-workqueue",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-writeback",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-x86-irq-vectors",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
+	{
+		.name = (char *) "lttng-probe-x86-exceptions",
+		.load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL,
+	},
 };
 
 /* dynamic probe modules list */
@@ -93,6 +234,9 @@ 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)
 {
@@ -106,6 +250,15 @@ static void log_kmod(void *data, int priority, const char *file, int line,
 	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;
@@ -128,8 +281,20 @@ 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
+ *
+ * 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 entries)
 {
 	int ret = 0, i;
 	struct kmod_ctx *ctx;
@@ -148,10 +313,13 @@ 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 (required) {
+		if (ret == -EEXIST) {
+			DBG("Module %s is already loaded", modules[i].name);
+			ret = 0;
+		} else if (ret < 0) {
+			if (modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED) {
 				ERR("Unable to load required module %s",
 						modules[i].name);
 				goto error;
@@ -162,6 +330,7 @@ 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);
@@ -174,6 +343,18 @@ 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;
@@ -202,8 +383,15 @@ static int rmmod_recurse(struct kmod_module *mod) {
 	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
+ *
+ */
 static void modprobe_remove_lttng(const struct kern_modules_param *modules,
-		int entries, int required)
+		int entries)
 {
 	int ret = 0, i;
 	struct kmod_ctx *ctx;
@@ -216,6 +404,10 @@ 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);
@@ -225,7 +417,7 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules,
 		ret = rmmod_recurse(mod);
 		if (ret == -EEXIST) {
 			DBG("Module %s is not in kernel.", modules[i].name);
-		} else if (required && ret < 0) {
+		} else if (modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED && ret < 0) {
 			ERR("Unable to remove module %s", modules[i].name);
 		} else {
 			DBG("Modprobe removal successful %s",
@@ -244,7 +436,7 @@ error:
 #else /* HAVE_KMOD */
 
 static int modprobe_lttng(struct kern_modules_param *modules,
-		int entries, int required)
+		int entries)
 {
 	int ret = 0, i;
 	char modprobe[256];
@@ -252,7 +444,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
 	for (i = 0; i < entries; i++) {
 		ret = snprintf(modprobe, sizeof(modprobe),
 				"/sbin/modprobe %s%s",
-				required ? "" : "-q ",
+				modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED ? "" : "-q ",
 				modules[i].name);
 		if (ret < 0) {
 			PERROR("snprintf modprobe");
@@ -261,7 +453,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
 		modprobe[sizeof(modprobe) - 1] = '\0';
 		ret = system(modprobe);
 		if (ret == -1) {
-			if (required) {
+			if (modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED) {
 				ERR("Unable to launch modprobe for required module %s",
 						modules[i].name);
 				goto error;
@@ -271,7 +463,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
 				ret = 0;
 			}
 		} else if (WEXITSTATUS(ret) != 0) {
-			if (required) {
+			if (modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED) {
 				ERR("Unable to load required module %s",
 						modules[i].name);
 				goto error;
@@ -282,6 +474,7 @@ static int modprobe_lttng(struct kern_modules_param *modules,
 			}
 		} else {
 			DBG("Modprobe successfully %s", modules[i].name);
+			modules[i].loaded = true;
 		}
 	}
 
@@ -290,12 +483,15 @@ error:
 }
 
 static void modprobe_remove_lttng(const struct kern_modules_param *modules,
-		int entries, int required)
+		int entries)
 {
 	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);
@@ -308,7 +504,7 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules,
 		if (ret == -1) {
 			ERR("Unable to launch modprobe -r for module %s",
 					modules[i].name);
-		} else if (required && WEXITSTATUS(ret) != 0) {
+		} else if (modules[i].load_policy == KERNEL_MODULE_PROPERTY_LOAD_POLICY_REQUIRED && WEXITSTATUS(ret) != 0) {
 			ERR("Unable to remove module %s",
 					modules[i].name);
 		} else {
@@ -326,8 +522,7 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules,
 void modprobe_remove_lttng_control(void)
 {
 	modprobe_remove_lttng(kern_modules_control_core,
-			      ARRAY_SIZE(kern_modules_control_core),
-			      LTTNG_MOD_REQUIRED);
+			ARRAY_SIZE(kern_modules_control_core));
 }
 
 static void free_probes(void)
@@ -353,7 +548,8 @@ void modprobe_remove_lttng_data(void)
 	if (!probes) {
 		return;
 	}
-	modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+
+	modprobe_remove_lttng(probes, nr_probes);
 	free_probes();
 }
 
@@ -371,12 +567,8 @@ void modprobe_remove_lttng_all(void)
  */
 int modprobe_lttng_control(void)
 {
-	int ret;
-
-	ret = modprobe_lttng(kern_modules_control_core,
-			     ARRAY_SIZE(kern_modules_control_core),
-			     LTTNG_MOD_REQUIRED);
-	return ret;
+	return modprobe_lttng(kern_modules_control_core,
+			ARRAY_SIZE(kern_modules_control_core));
 }
 
 /**
@@ -410,8 +602,8 @@ static int grow_probes(void)
 	}
 
 	for (i = 0; i < nr_probes; ++i) {
-		/* Move name pointer. */
-		tmp_probes[i].name = probes[i].name;
+		/* Ownership of 'name' field is transferred. */
+		tmp_probes[i] = probes[i];
 	}
 
 	/* Replace probes with larger copy. */
@@ -479,6 +671,8 @@ static int append_list_to_probes(const char *list)
 			goto error;
 		}
 
+		cur_mod->load_policy = KERNEL_MODULE_PROPERTY_LOAD_POLICY_OPTIONAL;
+
 		nr_probes++;
 	}
 
@@ -503,12 +697,7 @@ int modprobe_lttng_data(void)
 	 * 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();
-	}
-
+	list = config.kmod_probes_list.value;
 	if (list) {
 		/* User-specified probes. */
 		ret = append_list_to_probes(list);
@@ -537,18 +726,14 @@ int modprobe_lttng_data(void)
 			}
 
 			probes[i].name = name;
+			probes[i].load_policy = kern_modules_probes_default[i].load_policy;
 		}
 	}
 
 	/*
 	 * 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();
-	}
-
+	list = config.kmod_extra_probes_list.value;
 	if (list) {
 		ret = append_list_to_probes(list);
 		if (ret) {
@@ -559,7 +744,7 @@ int modprobe_lttng_data(void)
 	/*
 	 * Load probes modules now.
 	 */
-	ret = modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+	ret = modprobe_lttng(probes, nr_probes);
 	if (ret) {
 		goto error;
 	}