diff options
Diffstat (limited to 'kernel/params.c')
| -rw-r--r-- | kernel/params.c | 992 |
1 files changed, 992 insertions, 0 deletions
diff --git a/kernel/params.c b/kernel/params.c new file mode 100644 index 0000000000..2d4a056469 --- /dev/null +++ b/kernel/params.c @@ -0,0 +1,992 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Helpers for initial module or kernel cmdline parsing + Copyright (C) 2001 Rusty Russell. + +*/ +#include <linux/kernel.h> +#include <linux/kstrtox.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/ctype.h> +#include <linux/security.h> + +#ifdef CONFIG_SYSFS +/* Protects all built-in parameters, modules use their own param_lock */ +static DEFINE_MUTEX(param_lock); + +/* Use the module's mutex, or if built-in use the built-in mutex */ +#ifdef CONFIG_MODULES +#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) +#else +#define KPARAM_MUTEX(mod) (¶m_lock) +#endif + +static inline void check_kparam_locked(struct module *mod) +{ + BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); +} +#else +static inline void check_kparam_locked(struct module *mod) +{ +} +#endif /* !CONFIG_SYSFS */ + +/* This just allows us to keep track of which parameters are kmalloced. */ +struct kmalloced_param { + struct list_head list; + char val[]; +}; +static LIST_HEAD(kmalloced_params); +static DEFINE_SPINLOCK(kmalloced_params_lock); + +static void *kmalloc_parameter(unsigned int size) +{ + struct kmalloced_param *p; + + p = kmalloc(sizeof(*p) + size, GFP_KERNEL); + if (!p) + return NULL; + + spin_lock(&kmalloced_params_lock); + list_add(&p->list, &kmalloced_params); + spin_unlock(&kmalloced_params_lock); + + return p->val; +} + +/* Does nothing if parameter wasn't kmalloced above. */ +static void maybe_kfree_parameter(void *param) +{ + struct kmalloced_param *p; + + spin_lock(&kmalloced_params_lock); + list_for_each_entry(p, &kmalloced_params, list) { + if (p->val == param) { + list_del(&p->list); + kfree(p); + break; + } + } + spin_unlock(&kmalloced_params_lock); +} + +static char dash2underscore(char c) +{ + if (c == '-') + return '_'; + return c; +} + +bool parameqn(const char *a, const char *b, size_t n) +{ + size_t i; + + for (i = 0; i < n; i++) { + if (dash2underscore(a[i]) != dash2underscore(b[i])) + return false; + } + return true; +} + +bool parameq(const char *a, const char *b) +{ + return parameqn(a, b, strlen(a)+1); +} + +static bool param_check_unsafe(const struct kernel_param *kp) +{ + if (kp->flags & KERNEL_PARAM_FL_HWPARAM && + security_locked_down(LOCKDOWN_MODULE_PARAMETERS)) + return false; + + if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { + pr_notice("Setting dangerous option %s - tainting kernel\n", + kp->name); + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + } + + return true; +} + +static int parse_one(char *param, + char *val, + const char *doing, + const struct kernel_param *params, + unsigned num_params, + s16 min_level, + s16 max_level, + void *arg, + int (*handle_unknown)(char *param, char *val, + const char *doing, void *arg)) +{ + unsigned int i; + int err; + + /* Find parameter */ + for (i = 0; i < num_params; i++) { + if (parameq(param, params[i].name)) { + if (params[i].level < min_level + || params[i].level > max_level) + return 0; + /* No one handled NULL, so do it here. */ + if (!val && + !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG)) + return -EINVAL; + pr_debug("handling %s with %p\n", param, + params[i].ops->set); + kernel_param_lock(params[i].mod); + if (param_check_unsafe(¶ms[i])) + err = params[i].ops->set(val, ¶ms[i]); + else + err = -EPERM; + kernel_param_unlock(params[i].mod); + return err; + } + } + + if (handle_unknown) { + pr_debug("doing %s: %s='%s'\n", doing, param, val); + return handle_unknown(param, val, doing, arg); + } + + pr_debug("Unknown argument '%s'\n", param); + return -ENOENT; +} + +/* Args looks like "foo=bar,bar2 baz=fuz wiz". */ +char *parse_args(const char *doing, + char *args, + const struct kernel_param *params, + unsigned num, + s16 min_level, + s16 max_level, + void *arg, + int (*unknown)(char *param, char *val, + const char *doing, void *arg)) +{ + char *param, *val, *err = NULL; + + /* Chew leading spaces */ + args = skip_spaces(args); + + if (*args) + pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args); + + while (*args) { + int ret; + int irq_was_disabled; + + args = next_arg(args, ¶m, &val); + /* Stop at -- */ + if (!val && strcmp(param, "--") == 0) + return err ?: args; + irq_was_disabled = irqs_disabled(); + ret = parse_one(param, val, doing, params, num, + min_level, max_level, arg, unknown); + if (irq_was_disabled && !irqs_disabled()) + pr_warn("%s: option '%s' enabled irq's!\n", + doing, param); + + switch (ret) { + case 0: + continue; + case -ENOENT: + pr_err("%s: Unknown parameter `%s'\n", doing, param); + break; + case -ENOSPC: + pr_err("%s: `%s' too large for parameter `%s'\n", + doing, val ?: "", param); + break; + default: + pr_err("%s: `%s' invalid for parameter `%s'\n", + doing, val ?: "", param); + break; + } + + err = ERR_PTR(ret); + } + + return err; +} + +/* Lazy bastard, eh? */ +#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ + int param_set_##name(const char *val, const struct kernel_param *kp) \ + { \ + return strtolfn(val, 0, (type *)kp->arg); \ + } \ + int param_get_##name(char *buffer, const struct kernel_param *kp) \ + { \ + return scnprintf(buffer, PAGE_SIZE, format "\n", \ + *((type *)kp->arg)); \ + } \ + const struct kernel_param_ops param_ops_##name = { \ + .set = param_set_##name, \ + .get = param_get_##name, \ + }; \ + EXPORT_SYMBOL(param_set_##name); \ + EXPORT_SYMBOL(param_get_##name); \ + EXPORT_SYMBOL(param_ops_##name) + + +STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8); +STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16); +STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16); +STANDARD_PARAM_DEF(int, int, "%i", kstrtoint); +STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint); +STANDARD_PARAM_DEF(long, long, "%li", kstrtol); +STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); +STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); +STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint); + +int param_set_uint_minmax(const char *val, const struct kernel_param *kp, + unsigned int min, unsigned int max) +{ + unsigned int num; + int ret; + + if (!val) + return -EINVAL; + ret = kstrtouint(val, 0, &num); + if (ret) + return ret; + if (num < min || num > max) + return -EINVAL; + *((unsigned int *)kp->arg) = num; + return 0; +} +EXPORT_SYMBOL_GPL(param_set_uint_minmax); + +int param_set_charp(const char *val, const struct kernel_param *kp) +{ + if (strlen(val) > 1024) { + pr_err("%s: string parameter too long\n", kp->name); + return -ENOSPC; + } + + maybe_kfree_parameter(*(char **)kp->arg); + + /* This is a hack. We can't kmalloc in early boot, and we + * don't need to; this mangled commandline is preserved. */ + if (slab_is_available()) { + *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); + if (!*(char **)kp->arg) + return -ENOMEM; + strcpy(*(char **)kp->arg, val); + } else + *(const char **)kp->arg = val; + + return 0; +} +EXPORT_SYMBOL(param_set_charp); + +int param_get_charp(char *buffer, const struct kernel_param *kp) +{ + return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg)); +} +EXPORT_SYMBOL(param_get_charp); + +void param_free_charp(void *arg) +{ + maybe_kfree_parameter(*((char **)arg)); +} +EXPORT_SYMBOL(param_free_charp); + +const struct kernel_param_ops param_ops_charp = { + .set = param_set_charp, + .get = param_get_charp, + .free = param_free_charp, +}; +EXPORT_SYMBOL(param_ops_charp); + +/* Actually could be a bool or an int, for historical reasons. */ +int param_set_bool(const char *val, const struct kernel_param *kp) +{ + /* No equals means "set"... */ + if (!val) val = "1"; + + /* One of =[yYnN01] */ + return kstrtobool(val, kp->arg); +} +EXPORT_SYMBOL(param_set_bool); + +int param_get_bool(char *buffer, const struct kernel_param *kp) +{ + /* Y and N chosen as being relatively non-coder friendly */ + return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N'); +} +EXPORT_SYMBOL(param_get_bool); + +const struct kernel_param_ops param_ops_bool = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_bool, + .get = param_get_bool, +}; +EXPORT_SYMBOL(param_ops_bool); + +int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) +{ + int err; + bool new_value; + bool orig_value = *(bool *)kp->arg; + struct kernel_param dummy_kp = *kp; + + dummy_kp.arg = &new_value; + + err = param_set_bool(val, &dummy_kp); + if (err) + return err; + + /* Don't let them unset it once it's set! */ + if (!new_value && orig_value) + return -EROFS; + + if (new_value) + err = param_set_bool(val, kp); + + return err; +} +EXPORT_SYMBOL_GPL(param_set_bool_enable_only); + +const struct kernel_param_ops param_ops_bool_enable_only = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_bool_enable_only, + .get = param_get_bool, +}; +EXPORT_SYMBOL_GPL(param_ops_bool_enable_only); + +/* This one must be bool. */ +int param_set_invbool(const char *val, const struct kernel_param *kp) +{ + int ret; + bool boolval; + struct kernel_param dummy; + + dummy.arg = &boolval; + ret = param_set_bool(val, &dummy); + if (ret == 0) + *(bool *)kp->arg = !boolval; + return ret; +} +EXPORT_SYMBOL(param_set_invbool); + +int param_get_invbool(char *buffer, const struct kernel_param *kp) +{ + return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y'); +} +EXPORT_SYMBOL(param_get_invbool); + +const struct kernel_param_ops param_ops_invbool = { + .set = param_set_invbool, + .get = param_get_invbool, +}; +EXPORT_SYMBOL(param_ops_invbool); + +int param_set_bint(const char *val, const struct kernel_param *kp) +{ + /* Match bool exactly, by re-using it. */ + struct kernel_param boolkp = *kp; + bool v; + int ret; + + boolkp.arg = &v; + + ret = param_set_bool(val, &boolkp); + if (ret == 0) + *(int *)kp->arg = v; + return ret; +} +EXPORT_SYMBOL(param_set_bint); + +const struct kernel_param_ops param_ops_bint = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_bint, + .get = param_get_int, +}; +EXPORT_SYMBOL(param_ops_bint); + +/* We break the rule and mangle the string. */ +static int param_array(struct module *mod, + const char *name, + const char *val, + unsigned int min, unsigned int max, + void *elem, int elemsize, + int (*set)(const char *, const struct kernel_param *kp), + s16 level, + unsigned int *num) +{ + int ret; + struct kernel_param kp; + char save; + + /* Get the name right for errors. */ + kp.name = name; + kp.arg = elem; + kp.level = level; + + *num = 0; + /* We expect a comma-separated list of values. */ + do { + int len; + + if (*num == max) { + pr_err("%s: can only take %i arguments\n", name, max); + return -EINVAL; + } + len = strcspn(val, ","); + + /* nul-terminate and parse */ + save = val[len]; + ((char *)val)[len] = '\0'; + check_kparam_locked(mod); + ret = set(val, &kp); + + if (ret != 0) + return ret; + kp.arg += elemsize; + val += len+1; + (*num)++; + } while (save == ','); + + if (*num < min) { + pr_err("%s: needs at least %i arguments\n", name, min); + return -EINVAL; + } + return 0; +} + +static int param_array_set(const char *val, const struct kernel_param *kp) +{ + const struct kparam_array *arr = kp->arr; + unsigned int temp_num; + + return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem, + arr->elemsize, arr->ops->set, kp->level, + arr->num ?: &temp_num); +} + +static int param_array_get(char *buffer, const struct kernel_param *kp) +{ + int i, off, ret; + const struct kparam_array *arr = kp->arr; + struct kernel_param p = *kp; + + for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { + /* Replace \n with comma */ + if (i) + buffer[off - 1] = ','; + p.arg = arr->elem + arr->elemsize * i; + check_kparam_locked(p.mod); + ret = arr->ops->get(buffer + off, &p); + if (ret < 0) + return ret; + off += ret; + } + buffer[off] = '\0'; + return off; +} + +static void param_array_free(void *arg) +{ + unsigned int i; + const struct kparam_array *arr = arg; + + if (arr->ops->free) + for (i = 0; i < (arr->num ? *arr->num : arr->max); i++) + arr->ops->free(arr->elem + arr->elemsize * i); +} + +const struct kernel_param_ops param_array_ops = { + .set = param_array_set, + .get = param_array_get, + .free = param_array_free, +}; +EXPORT_SYMBOL(param_array_ops); + +int param_set_copystring(const char *val, const struct kernel_param *kp) +{ + const struct kparam_string *kps = kp->str; + + if (strlen(val)+1 > kps->maxlen) { + pr_err("%s: string doesn't fit in %u chars.\n", + kp->name, kps->maxlen-1); + return -ENOSPC; + } + strcpy(kps->string, val); + return 0; +} +EXPORT_SYMBOL(param_set_copystring); + +int param_get_string(char *buffer, const struct kernel_param *kp) +{ + const struct kparam_string *kps = kp->str; + return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string); +} +EXPORT_SYMBOL(param_get_string); + +const struct kernel_param_ops param_ops_string = { + .set = param_set_copystring, + .get = param_get_string, +}; +EXPORT_SYMBOL(param_ops_string); + +/* sysfs output in /sys/modules/XYZ/parameters/ */ +#define to_module_attr(n) container_of(n, struct module_attribute, attr) +#define to_module_kobject(n) container_of(n, struct module_kobject, kobj) + +struct param_attribute +{ + struct module_attribute mattr; + const struct kernel_param *param; +}; + +struct module_param_attrs +{ + unsigned int num; + struct attribute_group grp; + struct param_attribute attrs[]; +}; + +#ifdef CONFIG_SYSFS +#define to_param_attr(n) container_of(n, struct param_attribute, mattr) + +static ssize_t param_attr_show(struct module_attribute *mattr, + struct module_kobject *mk, char *buf) +{ + int count; + struct param_attribute *attribute = to_param_attr(mattr); + + if (!attribute->param->ops->get) + return -EPERM; + + kernel_param_lock(mk->mod); + count = attribute->param->ops->get(buf, attribute->param); + kernel_param_unlock(mk->mod); + return count; +} + +/* sysfs always hands a nul-terminated string in buf. We rely on that. */ +static ssize_t param_attr_store(struct module_attribute *mattr, + struct module_kobject *mk, + const char *buf, size_t len) +{ + int err; + struct param_attribute *attribute = to_param_attr(mattr); + + if (!attribute->param->ops->set) + return -EPERM; + + kernel_param_lock(mk->mod); + if (param_check_unsafe(attribute->param)) + err = attribute->param->ops->set(buf, attribute->param); + else + err = -EPERM; + kernel_param_unlock(mk->mod); + if (!err) + return len; + return err; +} +#endif + +#ifdef CONFIG_MODULES +#define __modinit +#else +#define __modinit __init +#endif + +#ifdef CONFIG_SYSFS +void kernel_param_lock(struct module *mod) +{ + mutex_lock(KPARAM_MUTEX(mod)); +} + +void kernel_param_unlock(struct module *mod) +{ + mutex_unlock(KPARAM_MUTEX(mod)); +} + +EXPORT_SYMBOL(kernel_param_lock); +EXPORT_SYMBOL(kernel_param_unlock); + +/* + * add_sysfs_param - add a parameter to sysfs + * @mk: struct module_kobject + * @kp: the actual parameter definition to add to sysfs + * @name: name of parameter + * + * Create a kobject if for a (per-module) parameter if mp NULL, and + * create file in sysfs. Returns an error on out of memory. Always cleans up + * if there's an error. + */ +static __modinit int add_sysfs_param(struct module_kobject *mk, + const struct kernel_param *kp, + const char *name) +{ + struct module_param_attrs *new_mp; + struct attribute **new_attrs; + unsigned int i; + + /* We don't bother calling this with invisible parameters. */ + BUG_ON(!kp->perm); + + if (!mk->mp) { + /* First allocation. */ + mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL); + if (!mk->mp) + return -ENOMEM; + mk->mp->grp.name = "parameters"; + /* NULL-terminated attribute array. */ + mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]), + GFP_KERNEL); + /* Caller will cleanup via free_module_param_attrs */ + if (!mk->mp->grp.attrs) + return -ENOMEM; + } + + /* Enlarge allocations. */ + new_mp = krealloc(mk->mp, + sizeof(*mk->mp) + + sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1), + GFP_KERNEL); + if (!new_mp) + return -ENOMEM; + mk->mp = new_mp; + + /* Extra pointer for NULL terminator */ + new_attrs = krealloc(mk->mp->grp.attrs, + sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2), + GFP_KERNEL); + if (!new_attrs) + return -ENOMEM; + mk->mp->grp.attrs = new_attrs; + + /* Tack new one on the end. */ + memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0])); + sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr); + mk->mp->attrs[mk->mp->num].param = kp; + mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show; + /* Do not allow runtime DAC changes to make param writable. */ + if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0) + mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store; + else + mk->mp->attrs[mk->mp->num].mattr.store = NULL; + mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name; + mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm; + mk->mp->num++; + + /* Fix up all the pointers, since krealloc can move us */ + for (i = 0; i < mk->mp->num; i++) + mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr; + mk->mp->grp.attrs[mk->mp->num] = NULL; + return 0; +} + +#ifdef CONFIG_MODULES +static void free_module_param_attrs(struct module_kobject *mk) +{ + if (mk->mp) + kfree(mk->mp->grp.attrs); + kfree(mk->mp); + mk->mp = NULL; +} + +/* + * module_param_sysfs_setup - setup sysfs support for one module + * @mod: module + * @kparam: module parameters (array) + * @num_params: number of module parameters + * + * Adds sysfs entries for module parameters under + * /sys/module/[mod->name]/parameters/ + */ +int module_param_sysfs_setup(struct module *mod, + const struct kernel_param *kparam, + unsigned int num_params) +{ + int i, err; + bool params = false; + + for (i = 0; i < num_params; i++) { + if (kparam[i].perm == 0) + continue; + err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); + if (err) { + free_module_param_attrs(&mod->mkobj); + return err; + } + params = true; + } + + if (!params) + return 0; + + /* Create the param group. */ + err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); + if (err) + free_module_param_attrs(&mod->mkobj); + return err; +} + +/* + * module_param_sysfs_remove - remove sysfs support for one module + * @mod: module + * + * Remove sysfs entries for module parameters and the corresponding + * kobject. + */ +void module_param_sysfs_remove(struct module *mod) +{ + if (mod->mkobj.mp) { + sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); + /* We are positive that no one is using any param + * attrs at this point. Deallocate immediately. */ + free_module_param_attrs(&mod->mkobj); + } +} +#endif + +void destroy_params(const struct kernel_param *params, unsigned num) +{ + unsigned int i; + + for (i = 0; i < num; i++) + if (params[i].ops->free) + params[i].ops->free(params[i].arg); +} + +static struct module_kobject * __init locate_module_kobject(const char *name) +{ + struct module_kobject *mk; + struct kobject *kobj; + int err; + + kobj = kset_find_obj(module_kset, name); + if (kobj) { + mk = to_module_kobject(kobj); + } else { + mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); + BUG_ON(!mk); + + mk->mod = THIS_MODULE; + mk->kobj.kset = module_kset; + err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, + "%s", name); +#ifdef CONFIG_MODULES + if (!err) + err = sysfs_create_file(&mk->kobj, &module_uevent.attr); +#endif + if (err) { + kobject_put(&mk->kobj); + pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n", + name, err); + return NULL; + } + + /* So that we hold reference in both cases. */ + kobject_get(&mk->kobj); + } + + return mk; +} + +static void __init kernel_add_sysfs_param(const char *name, + const struct kernel_param *kparam, + unsigned int name_skip) +{ + struct module_kobject *mk; + int err; + + mk = locate_module_kobject(name); + if (!mk) + return; + + /* We need to remove old parameters before adding more. */ + if (mk->mp) + sysfs_remove_group(&mk->kobj, &mk->mp->grp); + + /* These should not fail at boot. */ + err = add_sysfs_param(mk, kparam, kparam->name + name_skip); + BUG_ON(err); + err = sysfs_create_group(&mk->kobj, &mk->mp->grp); + BUG_ON(err); + kobject_uevent(&mk->kobj, KOBJ_ADD); + kobject_put(&mk->kobj); +} + +/* + * param_sysfs_builtin - add sysfs parameters for built-in modules + * + * Add module_parameters to sysfs for "modules" built into the kernel. + * + * The "module" name (KBUILD_MODNAME) is stored before a dot, the + * "parameter" name is stored behind a dot in kernel_param->name. So, + * extract the "module" name for all built-in kernel_param-eters, + * and for all who have the same, call kernel_add_sysfs_param. + */ +static void __init param_sysfs_builtin(void) +{ + const struct kernel_param *kp; + unsigned int name_len; + char modname[MODULE_NAME_LEN]; + + for (kp = __start___param; kp < __stop___param; kp++) { + char *dot; + + if (kp->perm == 0) + continue; + + dot = strchr(kp->name, '.'); + if (!dot) { + /* This happens for core_param() */ + strcpy(modname, "kernel"); + name_len = 0; + } else { + name_len = dot - kp->name + 1; + strscpy(modname, kp->name, name_len); + } + kernel_add_sysfs_param(modname, kp, name_len); + } +} + +ssize_t __modver_version_show(struct module_attribute *mattr, + struct module_kobject *mk, char *buf) +{ + struct module_version_attribute *vattr = + container_of(mattr, struct module_version_attribute, mattr); + + return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version); +} + +extern const struct module_version_attribute __start___modver[]; +extern const struct module_version_attribute __stop___modver[]; + +static void __init version_sysfs_builtin(void) +{ + const struct module_version_attribute *vattr; + struct module_kobject *mk; + int err; + + for (vattr = __start___modver; vattr < __stop___modver; vattr++) { + mk = locate_module_kobject(vattr->module_name); + if (mk) { + err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); + WARN_ON_ONCE(err); + kobject_uevent(&mk->kobj, KOBJ_ADD); + kobject_put(&mk->kobj); + } + } +} + +/* module-related sysfs stuff */ + +static ssize_t module_attr_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct module_attribute *attribute; + struct module_kobject *mk; + int ret; + + attribute = to_module_attr(attr); + mk = to_module_kobject(kobj); + + if (!attribute->show) + return -EIO; + + ret = attribute->show(attribute, mk, buf); + + return ret; +} + +static ssize_t module_attr_store(struct kobject *kobj, + struct attribute *attr, + const char *buf, size_t len) +{ + struct module_attribute *attribute; + struct module_kobject *mk; + int ret; + + attribute = to_module_attr(attr); + mk = to_module_kobject(kobj); + + if (!attribute->store) + return -EIO; + + ret = attribute->store(attribute, mk, buf, len); + + return ret; +} + +static const struct sysfs_ops module_sysfs_ops = { + .show = module_attr_show, + .store = module_attr_store, +}; + +static int uevent_filter(const struct kobject *kobj) +{ + const struct kobj_type *ktype = get_ktype(kobj); + + if (ktype == &module_ktype) + return 1; + return 0; +} + +static const struct kset_uevent_ops module_uevent_ops = { + .filter = uevent_filter, +}; + +struct kset *module_kset; + +static void module_kobj_release(struct kobject *kobj) +{ + struct module_kobject *mk = to_module_kobject(kobj); + complete(mk->kobj_completion); +} + +const struct kobj_type module_ktype = { + .release = module_kobj_release, + .sysfs_ops = &module_sysfs_ops, +}; + +/* + * param_sysfs_init - create "module" kset + * + * This must be done before the initramfs is unpacked and + * request_module() thus becomes possible, because otherwise the + * module load would fail in mod_sysfs_init. + */ +static int __init param_sysfs_init(void) +{ + module_kset = kset_create_and_add("module", &module_uevent_ops, NULL); + if (!module_kset) { + printk(KERN_WARNING "%s (%d): error creating kset\n", + __FILE__, __LINE__); + return -ENOMEM; + } + + return 0; +} +subsys_initcall(param_sysfs_init); + +/* + * param_sysfs_builtin_init - add sysfs version and parameter + * attributes for built-in modules + */ +static int __init param_sysfs_builtin_init(void) +{ + if (!module_kset) + return -ENOMEM; + + version_sysfs_builtin(); + param_sysfs_builtin(); + + return 0; +} +late_initcall(param_sysfs_builtin_init); + +#endif /* CONFIG_SYSFS */ |