/* Helpers for initial module or kernel cmdline parsing Copyright (C) 2001 Rusty Russell. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. 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. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/moduleparam.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/module.h> #include <linux/device.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/ctype.h> #if 0 #define DEBUGP printk #else #define DEBUGP(fmt, a...) #endif /* Protects all parameters, and incidentally kmalloced_param list. */ static DEFINE_MUTEX(param_lock); /* 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 void *kmalloc_parameter(unsigned int size) { struct kmalloced_param *p; p = kmalloc(sizeof(*p) + size, GFP_KERNEL); if (!p) return NULL; list_add(&p->list, &kmalloced_params); return p->val; } /* Does nothing if parameter wasn't kmalloced above. */ static void maybe_kfree_parameter(void *param) { struct kmalloced_param *p; list_for_each_entry(p, &kmalloced_params, list) { if (p->val == param) { list_del(&p->list); kfree(p); break; } } } static inline char dash2underscore(char c) { if (c == '-') return '_'; return c; } static inline int parameq(const char *input, const char *paramname) { unsigned int i; for (i = 0; dash2underscore(input[i]) == paramname[i]; i++) if (input[i] == '\0') return 1; return 0; } static int parse_one(char *param, char *val, const struct kernel_param *params, unsigned num_params, int (*handle_unknown)(char *param, char *val)) { unsigned int i; int err; /* Find parameter */ for (i = 0; i < num_params; i++) { if (parameq(param, params[i].name)) { /* Noone handled NULL, so do it here. */ if (!val && params[i].ops->set != param_set_bool) return -EINVAL; DEBUGP("They are equal! Calling %p\n", params[i].ops->set); mutex_lock(¶m_lock); err = params[i].ops->set(val, ¶ms[i]); mutex_unlock(¶m_lock); return err; } } if (handle_unknown) { DEBUGP("Unknown argument: calling %p\n", handle_unknown); return handle_unknown(param, val); } DEBUGP("Unknown argument `%s'\n", param); return -ENOENT; } /* You can use " around spaces, but can't escape ". */ /* Hyphens and underscores equivalent in parameter names. */ static char *next_arg(char *args, char **param, char **val) { unsigned int i, equals = 0; int in_quote = 0, quoted = 0; char *next; if (*args == '"') { args++; in_quote = 1; quoted = 1; } for (i = 0; args[i]; i++) { if (isspace(args[i]) && !in_quote) break; if (equals == 0) { if (args[i] == '=') equals = i; } if (args[i] == '"') in_quote = !in_quote; } *param = args; if (!equals) *val = NULL; else { args[equals] = '\0'; *val = args + equals + 1; /* Don't include quotes in value. */ if (**val == '"') { (*val)++; if (args[i-1] == '"') args[i-1] = '\0'; } if (quoted && args[i-1] == '"') args[i-1] = '\0'; } if (args[i]) { args[i] = '\0'; next = args + i + 1; } else next = args + i; /* Chew up trailing spaces. */ return skip_spaces(next); } /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ int parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, int (*unknown)(char *param, char *val)) { char *param, *val; DEBUGP("Parsing ARGS: %s\n", args); /* Chew leading spaces */ args = skip_spaces(args); while (*args) { int ret; int irq_was_disabled; args = next_arg(args, ¶m, &val); irq_was_disabled = irqs_disabled(); ret = parse_one(param, val, params, num, unknown); if (irq_was_disabled && !irqs_disabled()) { printk(KERN_WARNING "parse_args(): option '%s' enabled " "irq's!\n", param); } switch (ret) { case -ENOENT: printk(KERN_ERR "%s: Unknown parameter `%s'\n", name, param); return ret; case -ENOSPC: printk(KERN_ERR "%s: `%s' too large for parameter `%s'\n", name, val ?: "", param); return ret; case 0: break; default: printk(KERN_ERR "%s: `%s' invalid for parameter `%s'\n", name, val ?: "", param); return ret; } } /* All parsed OK. */ return 0; } /* Lazy bastard, eh? */ #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \ int param_set_##name(const char *val, const struct kernel_param *kp) \ { \ tmptype l; \ int ret; \ \ ret = strtolfn(val, 0, &l); \ if (ret == -EINVAL || ((type)l != l)) \ return -EINVAL; \ *((type *)kp->arg) = l; \ return 0; \ } \ int param_get_##name(char *buffer, const struct kernel_param *kp) \ { \ return sprintf(buffer, format, *((type *)kp->arg)); \ } \ 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, "%c", unsigned long, strict_strtoul); STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol); STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul); STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol); STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul); STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol); STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul); int param_set_charp(const char *val, const struct kernel_param *kp) { if (strlen(val) > 1024) { printk(KERN_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 sprintf(buffer, "%s", *((char **)kp->arg)); } EXPORT_SYMBOL(param_get_charp); static void param_free_charp(void *arg) { maybe_kfree_parameter(*((char **)arg)); } 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) { bool v; /* No equals means "set"... */ if (!val) val = "1"; /* One of =[yYnN01] */ switch (val[0]) { case 'y': case 'Y': case '1': v = true; break; case 'n': case 'N': case '0': v = false; break; default: return -EINVAL; } if (kp->flags & KPARAM_ISBOOL) *(bool *)kp->arg = v; else *(int *)kp->arg = v; return 0; } EXPORT_SYMBOL(param_set_bool); int param_get_bool(char *buffer, const struct kernel_param *kp) { bool val; if (kp->flags & KPARAM_ISBOOL) val = *(bool *)kp->arg; else val = *(int *)kp->arg; /* Y and N chosen as being relatively non-coder friendly */ return sprintf(buffer, "%c", val ? 'Y' : 'N'); } EXPORT_SYMBOL(param_get_bool); struct kernel_param_ops param_ops_bool = { .set = param_set_bool, .get = param_get_bool, }; EXPORT_SYMBOL(param_ops_bool); /* 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; dummy.flags = KPARAM_ISBOOL; 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", (*(bool *)kp->arg) ? 'N' : 'Y'); } EXPORT_SYMBOL(param_get_invbool); struct kernel_param_ops param_ops_invbool = { .set = param_set_invbool, .get = param_get_invbool, }; EXPORT_SYMBOL(param_ops_invbool); /* We break the rule and mangle the string. */ static int param_array(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), u16 flags, unsigned int *num) { int ret; struct kernel_param kp; char save; /* Get the name right for errors. */ kp.name = name; kp.arg = elem; kp.flags = flags; *num = 0; /* We expect a comma-separated list of values. */ do { int len; if (*num == max) { printk(KERN_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'; BUG_ON(!mutex_is_locked(¶m_lock)); ret = set(val, &kp); if (ret != 0) return ret; kp.arg += elemsize; val += len+1; (*num)++; } while (save == ','); if (*num < min) { printk(KERN_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->name, val, 1, arr->max, arr->elem, arr->elemsize, arr->ops->set, kp->flags, 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; p = *kp; for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { if (i) buffer[off++] = ','; p.arg = arr->elem + arr->elemsize * i; BUG_ON(!mutex_is_locked(¶m_lock)); 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); } 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) { printk(KERN_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 strlcpy(buffer, kps->string, kps->maxlen); } EXPORT_SYMBOL(param_get_string); 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) extern struct kernel_param __start___param[], __stop___param[]; 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[0]; }; #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 *mod, char *buf) { int count; struct param_attribute *attribute = to_param_attr(mattr); if (!attribute->param->ops->get) return -EPERM; mutex_lock(¶m_lock); count = attribute->param->ops->get(buf, attribute->param); mutex_unlock(¶m_lock); if (count > 0) { strcat(buf, "\n"); ++count; } 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 *owner, const char *buf, size_t len) { int err; struct param_attribute *attribute = to_param_attr(mattr); if (!attribute->param->ops->set) return -EPERM; mutex_lock(¶m_lock); err = attribute->param->ops->set(buf, attribute->param); mutex_unlock(¶m_lock); if (!err) return len; return err; } #endif #ifdef CONFIG_MODULES #define __modinit #else #define __modinit __init #endif #ifdef CONFIG_SYSFS void __kernel_param_lock(void) { mutex_lock(¶m_lock); } EXPORT_SYMBOL(__kernel_param_lock); void __kernel_param_unlock(void) { mutex_unlock(¶m_lock); } EXPORT_SYMBOL(__kernel_param_unlock); /* * add_sysfs_param - add a parameter to sysfs * @mk: struct module_kobject * @kparam: 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; struct attribute **attrs; int err, num; /* We don't bother calling this with invisible parameters. */ BUG_ON(!kp->perm); if (!mk->mp) { num = 0; attrs = NULL; } else { num = mk->mp->num; attrs = mk->mp->grp.attrs; } /* Enlarge. */ new = krealloc(mk->mp, sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), GFP_KERNEL); if (!new) { kfree(mk->mp); err = -ENOMEM; goto fail; } attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); if (!attrs) { err = -ENOMEM; goto fail_free_new; } /* Sysfs wants everything zeroed. */ memset(new, 0, sizeof(*new)); memset(&new->attrs[num], 0, sizeof(new->attrs[num])); memset(&attrs[num], 0, sizeof(attrs[num])); new->grp.name = "parameters"; new->grp.attrs = attrs; /* Tack new one on the end. */ sysfs_attr_init(&new->attrs[num].mattr.attr); new->attrs[num].param = kp; new->attrs[num].mattr.show = param_attr_show; new->attrs[num].mattr.store = param_attr_store; new->attrs[num].mattr.attr.name = (char *)name; new->attrs[num].mattr.attr.mode = kp->perm; new->num = num+1; /* Fix up all the pointers, since krealloc can move us */ for (num = 0; num < new->num; num++) new->grp.attrs[num] = &new->attrs[num].mattr.attr; new->grp.attrs[num] = NULL; mk->mp = new; return 0; fail_free_new: kfree(new); fail: mk->mp = NULL; return err; } #ifdef CONFIG_MODULES static void free_module_param_attrs(struct module_kobject *mk) { 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) 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 void __init kernel_add_sysfs_param(const char *name, struct kernel_param *kparam, unsigned int name_skip) { struct module_kobject *mk; struct kobject *kobj; int err; kobj = kset_find_obj(module_kset, name); if (kobj) { /* We already have one. Remove params so we can add more. */ mk = to_module_kobject(kobj); /* We need to remove it before adding parameters. */ sysfs_remove_group(&mk->kobj, &mk->mp->grp); } 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); if (err) { kobject_put(&mk->kobj); printk(KERN_ERR "Module '%s' failed add to sysfs, " "error number %d\n", name, err); printk(KERN_ERR "The system will be unstable now.\n"); return; } /* So that exit path is even. */ kobject_get(&mk->kobj); } /* 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 contents in /sys/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) { 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; strlcpy(modname, kp->name, name_len); } kernel_add_sysfs_param(modname, kp, name_len); } } /* 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->mod, 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->mod, buf, len); return ret; } static const struct sysfs_ops module_sysfs_ops = { .show = module_attr_show, .store = module_attr_store, }; static int uevent_filter(struct kset *kset, struct kobject *kobj) { 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; int module_sysfs_initialized; struct kobj_type module_ktype = { .sysfs_ops = &module_sysfs_ops, }; /* * param_sysfs_init - wrapper for built-in params support */ 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; } module_sysfs_initialized = 1; param_sysfs_builtin(); return 0; } subsys_initcall(param_sysfs_init); #endif /* CONFIG_SYSFS */