X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fmodprobe.c;h=75d6387c6fbe6b6c887d2117ee8c62ac6a242199;hp=6f9a9978a75496f2510b9302b0b058008d3cc206;hb=e6142f2e647e83238b1e399b1264e8adb05409f9;hpb=35e090b7b37c53e911e61007d0d08e424ab39470 diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c index 6f9a9978a..75d6387c6 100644 --- a/src/bin/lttng-sessiond/modprobe.c +++ b/src/bin/lttng-sessiond/modprobe.c @@ -16,6 +16,13 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ +/** + * @file modprobe.c + * + * @brief modprobe related functions. + * + */ + #define _LGPL_SOURCE #include #include @@ -27,6 +34,7 @@ #include "modprobe.h" #include "kern-modules.h" +#include "lttng-sessiond.h" #define LTTNG_MOD_REQUIRED 1 #define LTTNG_MOD_OPTIONAL 0 @@ -50,6 +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" }, @@ -92,6 +101,10 @@ static int probes_capacity; #if HAVE_KMOD #include + +/** + * @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) { @@ -104,21 +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; @@ -129,9 +182,12 @@ 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 (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); @@ -143,6 +199,7 @@ 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); @@ -155,6 +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, @@ -196,6 +344,7 @@ static int modprobe_lttng(struct kern_modules_param *modules, } } else { DBG("Modprobe successfully %s", modules[i].name); + modules[i].loaded = true; } } @@ -203,8 +352,6 @@ error: return ret; } -#endif /* HAVE_KMOD */ - static void modprobe_remove_lttng(const struct kern_modules_param *modules, int entries, int required) { @@ -212,6 +359,9 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules, 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); @@ -234,6 +384,8 @@ static void modprobe_remove_lttng(const struct kern_modules_param *modules, } } +#endif /* HAVE_KMOD */ + /* * Remove control kernel module(s) in reverse load order. */ @@ -417,12 +569,7 @@ 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); @@ -457,12 +604,7 @@ int modprobe_lttng_data(void) /* * 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) {