* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
+/**
+ * @file modprobe.c
+ *
+ * @brief modprobe related functions.
+ *
+ */
+
#define _LGPL_SOURCE
#include <assert.h>
#include <stdio.h>
#include "modprobe.h"
#include "kern-modules.h"
+#include "lttng-sessiond.h"
#define LTTNG_MOD_REQUIRED 1
#define LTTNG_MOD_OPTIONAL 0
{ "lttng-probe-ext3" },
{ "lttng-probe-ext4" },
{ "lttng-probe-gpio" },
+ { "lttng-probe-i2c" },
{ "lttng-probe-irq" },
{ "lttng-probe-jbd" },
{ "lttng-probe-jbd2" },
#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)
{
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;
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);
}
} else {
DBG("Modprobe successfully %s", modules[i].name);
+ modules[i].loaded = true;
}
kmod_module_unref(mod);
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,
}
} else {
DBG("Modprobe successfully %s", modules[i].name);
+ modules[i].loaded = true;
}
}
return ret;
}
-#endif /* HAVE_KMOD */
-
static void modprobe_remove_lttng(const struct kern_modules_param *modules,
int entries, int required)
{
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);
}
}
+#endif /* HAVE_KMOD */
+
/*
* Remove control kernel module(s) in reverse load order.
*/
* 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);
/*
* 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) {
projects / lttng-tools.git / blobdiff