diff --git a/libkmod/docs/libkmod-sections.txt b/libkmod/docs/libkmod-sections.txt index 33d9eec..978b064 100644 --- a/libkmod/docs/libkmod-sections.txt +++ b/libkmod/docs/libkmod-sections.txt @@ -37,6 +37,7 @@ kmod_config_get_remove_commands kmod_config_get_aliases kmod_config_get_options kmod_config_get_softdeps +kmod_config_get_weakdeps kmod_config_iter_get_key kmod_config_iter_get_value kmod_config_iter_next @@ -62,6 +63,7 @@ kmod_module_remove_module kmod_module_get_module kmod_module_get_dependencies kmod_module_get_softdeps +kmod_module_get_weakdeps kmod_module_apply_filter kmod_module_get_filtered_blacklist kmod_module_get_install_commands diff --git a/libkmod/libkmod-config.c b/libkmod/libkmod-config.c index e83621b..a571b6b 100644 --- a/libkmod/libkmod-config.c +++ b/libkmod/libkmod-config.c @@ -58,6 +58,12 @@ struct kmod_softdep { unsigned int n_post; }; +struct kmod_weakdep { + char *name; + const char **weak; + unsigned int n_weak; +}; + const char *kmod_blacklist_get_modname(const struct kmod_list *l) { return l->data; @@ -110,6 +116,16 @@ const char * const *kmod_softdep_get_post(const struct kmod_list *l, unsigned in return dep->post; } +const char *kmod_weakdep_get_name(const struct kmod_list *l) { + const struct kmod_weakdep *dep = l->data; + return dep->name; +} + +const char * const *kmod_weakdep_get_weak(const struct kmod_list *l, unsigned int *count) { + const struct kmod_weakdep *dep = l->data; + *count = dep->n_weak; + return dep->weak; +} static int kmod_config_add_command(struct kmod_config *config, const char *modname, const char *command, @@ -392,6 +408,112 @@ static int kmod_config_add_softdep(struct kmod_config *config, return 0; } +static int kmod_config_add_weakdep(struct kmod_config *config, + const char *modname, + const char *line) +{ + struct kmod_list *list; + struct kmod_weakdep *dep; + const char *s, *p; + char *itr; + unsigned int n_weak = 0; + size_t modnamelen = strlen(modname) + 1; + size_t buflen = 0; + bool was_space = false; + + DBG(config->ctx, "modname=%s\n", modname); + + /* analyze and count */ + for (p = s = line; ; s++) { + size_t plen; + + if (*s != '\0') { + if (!isspace(*s)) { + was_space = false; + continue; + } + + if (was_space) { + p = s + 1; + continue; + } + was_space = true; + + if (p >= s) + continue; + } + plen = s - p; + + if (*s != '\0' || (*s == '\0' && !was_space)) { + buflen += plen + 1; + n_weak++; + } + p = s + 1; + if (*s == '\0') + break; + } + + DBG(config->ctx, "%u weak\n", n_weak); + + dep = malloc(sizeof(struct kmod_weakdep) + modnamelen + + n_weak * sizeof(const char *) + + buflen); + if (dep == NULL) { + ERR(config->ctx, "out-of-memory modname=%s\n", modname); + return -ENOMEM; + } + dep->n_weak = n_weak; + dep->weak = (const char **)((char *)dep + sizeof(struct kmod_weakdep)); + dep->name = (char *)(dep->weak + n_weak); + + memcpy(dep->name, modname, modnamelen); + + /* copy strings */ + itr = dep->name + modnamelen; + n_weak = 0; + was_space = false; + for (p = s = line; ; s++) { + size_t plen; + + if (*s != '\0') { + if (!isspace(*s)) { + was_space = false; + continue; + } + + if (was_space) { + p = s + 1; + continue; + } + was_space = true; + + if (p >= s) + continue; + } + plen = s - p; + + if (*s != '\0' || (*s == '\0' && !was_space)) { + dep->weak[n_weak] = itr; + memcpy(itr, p, plen); + itr[plen] = '\0'; + itr += plen + 1; + n_weak++; + } + p = s + 1; + if (*s == '\0') + break; + } + + list = kmod_list_append(config->weakdeps, dep); + if (list == NULL) { + free(dep); + return -ENOMEM; + } + config->weakdeps = list; + + return 0; +} + static char *softdep_to_char(struct kmod_softdep *dep) { const size_t sz_preprefix = sizeof("pre: ") - 1; const size_t sz_postprefix = sizeof("post: ") - 1; @@ -461,6 +583,44 @@ static char *softdep_to_char(struct kmod_softdep *dep) { return s; } +static char *weakdep_to_char(struct kmod_weakdep *dep) { + size_t sz; + const char *start, *end; + char *s, *itr; + + /* + * Rely on the fact that dep->weak[] and are strv's that point to a + * contiguous buffer + */ + if (dep->n_weak > 0) { + start = dep->weak[0]; + end = dep->weak[dep->n_weak - 1] + + strlen(dep->weak[dep->n_weak - 1]); + sz = end - start; + } else + sz = 0; + + itr = s = malloc(sz); + if (s == NULL) + return NULL; + + if (sz) { + char *p; + + /* include last '\0' */ + memcpy(itr, dep->weak[0], sz + 1); + for (p = itr; p < itr + sz; p++) { + if (*p == '\0') + *p = ' '; + } + itr = p; + } + + *itr = '\0'; + + return s; +} + static void kmod_config_free_softdep(struct kmod_config *config, struct kmod_list *l) { @@ -468,6 +628,13 @@ static void kmod_config_free_softdep(struct kmod_config *config, config->softdeps = kmod_list_remove(l); } +static void kmod_config_free_weakdep(struct kmod_config *config, + struct kmod_list *l) +{ + free(l->data); + config->weakdeps = kmod_list_remove(l); +} + static void kcmdline_parse_result(struct kmod_config *config, char *modname, char *param, char *value) { @@ -703,6 +870,14 @@ static int kmod_config_parse(struct kmod_config *config, int fd, goto syntax_error; kmod_config_add_softdep(config, modname, softdeps); + } else if (streq(cmd, "weakdep")) { + char *modname = strtok_r(NULL, "\t ", &saveptr); + char *weakdeps = strtok_r(NULL, "\0", &saveptr); + + if (underscores(modname) < 0 || weakdeps == NULL) + goto syntax_error; + + kmod_config_add_weakdep(config, modname, weakdeps); } else if (streq(cmd, "include") || streq(cmd, "config")) { ERR(ctx, "%s: command %s is deprecated and not parsed anymore\n", @@ -746,6 +921,9 @@ void kmod_config_free(struct kmod_config *config) while (config->softdeps) kmod_config_free_softdep(config, config->softdeps); + while (config->weakdeps) + kmod_config_free_weakdep(config, config->weakdeps); + for (; config->paths != NULL; config->paths = kmod_list_remove(config->paths)) free(config->paths->data); @@ -889,6 +1067,7 @@ int kmod_config_new(struct kmod_ctx *ctx, struct kmod_config **p_config, size_t i; conf_files_insert_sorted(ctx, &list, kmod_get_dirname(ctx), "modules.softdep"); + conf_files_insert_sorted(ctx, &list, kmod_get_dirname(ctx), "modules.weakdep"); for (i = 0; config_paths[i] != NULL; i++) { const char *path = config_paths[i]; @@ -973,6 +1152,7 @@ enum config_type { CONFIG_TYPE_ALIAS, CONFIG_TYPE_OPTION, CONFIG_TYPE_SOFTDEP, + CONFIG_TYPE_WEAKDEP, }; struct kmod_config_iter { @@ -991,6 +1171,12 @@ static const char *softdep_get_plain_softdep(const struct kmod_list *l) return s; } +static const char *weakdep_get_plain_weakdep(const struct kmod_list *l) +{ + char *s = weakdep_to_char(l->data); + return s; +} + static struct kmod_config_iter *kmod_config_iter_new(const struct kmod_ctx* ctx, enum config_type type) { @@ -1033,6 +1219,12 @@ static struct kmod_config_iter *kmod_config_iter_new(const struct kmod_ctx* ctx, iter->get_value = softdep_get_plain_softdep; iter->intermediate = true; break; + case CONFIG_TYPE_WEAKDEP: + iter->list = config->weakdeps; + iter->get_key = kmod_weakdep_get_name; + iter->get_value = weakdep_get_plain_weakdep; + iter->intermediate = true; + break; } return iter; @@ -1163,6 +1355,26 @@ KMOD_EXPORT struct kmod_config_iter *kmod_config_get_softdeps(const struct kmod_ return kmod_config_iter_new(ctx, CONFIG_TYPE_SOFTDEP); } +/** + * kmod_config_get_weakdeps: + * @ctx: kmod library context + * + * Retrieve an iterator to deal with the weakdeps maintained inside the + * library. See kmod_config_iter_get_key(), kmod_config_iter_get_value() and + * kmod_config_iter_next(). At least one call to kmod_config_iter_next() must + * be made to initialize the iterator and check if it's valid. + * + * Returns: a new iterator over the weakdeps or NULL on failure. Free it with + * kmod_config_iter_free_iter(). + */ +KMOD_EXPORT struct kmod_config_iter *kmod_config_get_weakdeps(const struct kmod_ctx *ctx) +{ + if (ctx == NULL) + return NULL;; + + return kmod_config_iter_new(ctx, CONFIG_TYPE_WEAKDEP); +} + /** * kmod_config_iter_get_key: * @iter: iterator over a certain configuration diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h index 3bc6e11..4e1cc20 100644 --- a/libkmod/libkmod-internal.h +++ b/libkmod/libkmod-internal.h @@ -128,6 +128,7 @@ struct kmod_config { struct kmod_list *remove_commands; struct kmod_list *install_commands; struct kmod_list *softdeps; + struct kmod_list *weakdeps; struct kmod_list *paths; }; @@ -146,6 +147,8 @@ const char *kmod_softdep_get_name(const struct kmod_list *l) __attribute__((nonn const char * const *kmod_softdep_get_pre(const struct kmod_list *l, unsigned int *count) __attribute__((nonnull(1, 2))); const char * const *kmod_softdep_get_post(const struct kmod_list *l, unsigned int *count); +const char *kmod_weakdep_get_name(const struct kmod_list *l) __attribute__((nonnull(1))); +const char * const *kmod_weakdep_get_weak(const struct kmod_list *l, unsigned int *count) __attribute__((nonnull(1, 2))); /* libkmod-module.c */ int kmod_module_new_from_alias(struct kmod_ctx *ctx, const char *alias, const char *name, struct kmod_module **mod); diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c index d309948..5c26e03 100644 --- a/libkmod/libkmod-module.c +++ b/libkmod/libkmod-module.c @@ -1591,7 +1591,7 @@ void kmod_module_set_install_commands(struct kmod_module *mod, const char *cmd) mod->install_commands = cmd; } -static struct kmod_list *lookup_softdep(struct kmod_ctx *ctx, const char * const * array, unsigned int count) +static struct kmod_list *lookup_dep(struct kmod_ctx *ctx, const char * const * array, unsigned int count) { struct kmod_list *ret = NULL; unsigned i; @@ -1603,7 +1603,7 @@ static struct kmod_list *lookup_softdep(struct kmod_ctx *ctx, const char * const err = kmod_module_new_from_lookup(ctx, depname, &lst); if (err < 0) { - ERR(ctx, "failed to lookup soft dependency '%s', continuing anyway.\n", depname); + ERR(ctx, "failed to lookup dependency '%s', continuing anyway.\n", depname); continue; } else if (lst != NULL) ret = kmod_list_append_list(ret, lst); @@ -1652,9 +1652,59 @@ KMOD_EXPORT int kmod_module_get_softdeps(const struct kmod_module *mod, continue; array = kmod_softdep_get_pre(l, &count); - *pre = lookup_softdep(mod->ctx, array, count); + *pre = lookup_dep(mod->ctx, array, count); array = kmod_softdep_get_post(l, &count); - *post = lookup_softdep(mod->ctx, array, count); + *post = lookup_dep(mod->ctx, array, count); + + /* + * find only the first command, as modprobe from + * module-init-tools does + */ + break; + } + + return 0; +} + +/* + * kmod_module_get_weakdeps: + * @mod: kmod module + * @weak: where to save the list of weak dependencies. + * + * Get weak dependencies for this kmod module. Weak dependencies come + * from configuration file and are not cached in @mod because it may include + * dependency cycles that would make we leak kmod_module. Any call + * to this function will search for this module in configuration, allocate a + * list and return the result. + * + * @weak is newly created list of kmod_module and + * should be unreferenced with kmod_module_unref_list(). + * + * Returns: 0 on success or < 0 otherwise. + */ +KMOD_EXPORT int kmod_module_get_weakdeps(const struct kmod_module *mod, + struct kmod_list **weak) +{ + const struct kmod_list *l; + const struct kmod_config *config; + + if (mod == NULL || weak == NULL) + return -ENOENT; + + assert(*weak == NULL); + + config = kmod_get_config(mod->ctx); + + kmod_list_foreach(l, config->weakdeps) { + const char *modname = kmod_weakdep_get_name(l); + const char * const *array; + unsigned count; + + if (fnmatch(modname, mod->name, 0) != 0) + continue; + + array = kmod_weakdep_get_weak(l, &count); + *weak = lookup_dep(mod->ctx, array, count); /* * find only the first command, as modprobe from diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h index 7251aa7..fce66d1 100644 --- a/libkmod/libkmod.h +++ b/libkmod/libkmod.h @@ -112,6 +112,7 @@ struct kmod_config_iter *kmod_config_get_remove_commands(const struct kmod_ctx * struct kmod_config_iter *kmod_config_get_aliases(const struct kmod_ctx *ctx); struct kmod_config_iter *kmod_config_get_options(const struct kmod_ctx *ctx); struct kmod_config_iter *kmod_config_get_softdeps(const struct kmod_ctx *ctx); +struct kmod_config_iter *kmod_config_get_weakdeps(const struct kmod_ctx *ctx); const char *kmod_config_iter_get_key(const struct kmod_config_iter *iter); const char *kmod_config_iter_get_value(const struct kmod_config_iter *iter); bool kmod_config_iter_next(struct kmod_config_iter *iter); @@ -196,6 +197,8 @@ const char *kmod_module_get_remove_commands(const struct kmod_module *mod); struct kmod_list *kmod_module_get_dependencies(const struct kmod_module *mod); int kmod_module_get_softdeps(const struct kmod_module *mod, struct kmod_list **pre, struct kmod_list **post); +int kmod_module_get_weakdeps(const struct kmod_module *mod, + struct kmod_list **weak); int kmod_module_get_filtered_blacklist(const struct kmod_ctx *ctx, const struct kmod_list *input, struct kmod_list **output) __attribute__ ((deprecated)); diff --git a/libkmod/libkmod.sym b/libkmod/libkmod.sym index 0c04fda..0d6d338 100644 --- a/libkmod/libkmod.sym +++ b/libkmod/libkmod.sym @@ -21,6 +21,7 @@ global: kmod_config_get_aliases; kmod_config_get_options; kmod_config_get_softdeps; + kmod_config_get_weakdeps; kmod_config_iter_get_key; kmod_config_iter_get_value; kmod_config_iter_next; @@ -42,6 +43,7 @@ global: kmod_module_get_dependencies; kmod_module_get_softdeps; + kmod_module_get_weakdeps; kmod_module_get_filtered_blacklist; kmod_module_get_name; diff --git a/man/modprobe.d.5.xml b/man/modprobe.d.5.xml index 2bf6537..cc90da6 100644 --- a/man/modprobe.d.5.xml +++ b/man/modprobe.d.5.xml @@ -212,6 +212,30 @@ + + weakdep modulename modules... + + + + The weakdep command allows you to specify weak module + dependencies. Those are similar to pre softdep, with the + difference that userspace doesn't attempt to load that + dependency before the specified module. Instead the kernel + may request one or multiple of them during module probe, + depending on the hardware it's binding to. The purpose of + weak module is to allow a driver to specify that a certain + dependency may be needed, so it should be present in the + filesystem (e.g. in initramfs) when that module is probed. + + + Example: Assume "weakdep c a b". A program creating an + initramfs knows it should add a, b, and c to the filesystem + since a and b may be required/desired at runtime. When c is + loaded and is being probed, it may issue calls to + request_module() causing a or b to also be loaded. + + + COMPATIBILITY diff --git a/tools/depmod.c b/tools/depmod.c index 43fc354..06618fa 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -2296,6 +2296,30 @@ static int output_softdeps(struct depmod *depmod, FILE *out) return 0; } +static int output_weakdeps(struct depmod *depmod, FILE *out) +{ + size_t i; + + fputs("# Weak dependencies extracted from modules themselves.\n", out); + + for (i = 0; i < depmod->modules.count; i++) { + const struct mod *mod = depmod->modules.array[i]; + struct kmod_list *l; + + kmod_list_foreach(l, mod->info_list) { + const char *key = kmod_module_info_get_key(l); + const char *value = kmod_module_info_get_value(l); + + if (!streq(key, "weakdep")) + continue; + + fprintf(out, "weakdep %s %s\n", mod->modname, value); + } + } + + return 0; +} + static int output_symbols(struct depmod *depmod, FILE *out) { struct hash_iter iter; @@ -2574,6 +2598,7 @@ static int depmod_output(struct depmod *depmod, FILE *out) { "modules.alias", output_aliases }, { "modules.alias.bin", output_aliases_bin }, { "modules.softdep", output_softdeps }, + { "modules.weakdep", output_weakdeps }, { "modules.symbols", output_symbols }, { "modules.symbols.bin", output_symbols_bin }, { "modules.builtin.bin", output_builtin_bin }, diff --git a/tools/modprobe.c b/tools/modprobe.c index 5306bef..4328da6 100644 --- a/tools/modprobe.c +++ b/tools/modprobe.c @@ -182,6 +182,7 @@ static int show_config(struct kmod_ctx *ctx) { "alias", kmod_config_get_aliases }, { "options", kmod_config_get_options }, { "softdep", kmod_config_get_softdeps }, + { "weakdep", kmod_config_get_weakdeps }, }; size_t i;