Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

937 lines (793 sloc) 22.228 kb
/* 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/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>
/* 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 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 int parse_one(char *param,
char *val,
const char *doing,
const struct kernel_param *params,
unsigned num_params,
s16 min_level,
s16 max_level,
int (*handle_unknown)(char *param, char *val,
const char *doing))
{
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->set != param_set_bool
&& params[i].ops->set != param_set_bint)
return -EINVAL;
pr_debug("handling %s with %p\n", param,
params[i].ops->set);
mutex_lock(&param_lock);
err = params[i].ops->set(val, &params[i]);
mutex_unlock(&param_lock);
return err;
}
}
if (handle_unknown) {
pr_debug("doing %s: %s='%s'\n", doing, param, val);
return handle_unknown(param, val, doing);
}
pr_debug("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 *doing,
char *args,
const struct kernel_param *params,
unsigned num,
s16 min_level,
s16 max_level,
int (*unknown)(char *param, char *val, const char *doing))
{
char *param, *val;
/* 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, &param, &val);
irq_was_disabled = irqs_disabled();
ret = parse_one(param, val, doing, params, num,
min_level, max_level, unknown);
if (irq_was_disabled && !irqs_disabled())
pr_warn("%s: option '%s' enabled irq's!\n",
doing, param);
switch (ret) {
case -ENOENT:
pr_err("%s: Unknown parameter `%s'\n", doing, param);
return ret;
case -ENOSPC:
pr_err("%s: `%s' too large for parameter `%s'\n",
doing, val ?: "", param);
return ret;
case 0:
break;
default:
pr_err("%s: `%s' invalid for parameter `%s'\n",
doing, 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 < 0 || ((type)l != l)) \
return ret < 0 ? ret : -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) {
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 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)
{
/* No equals means "set"... */
if (!val) val = "1";
/* One of =[yYnN01] */
return strtobool(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", *(bool *)kp->arg ? '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;
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);
int param_set_bint(const char *val, const struct kernel_param *kp)
{
struct kernel_param boolkp;
bool v;
int ret;
/* Match bool exactly, by re-using it. */
boolkp = *kp;
boolkp.arg = &v;
ret = param_set_bool(val, &boolkp);
if (ret == 0)
*(int *)kp->arg = v;
return ret;
}
EXPORT_SYMBOL(param_set_bint);
struct kernel_param_ops param_ops_bint = {
.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(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';
BUG_ON(!mutex_is_locked(&param_lock));
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->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;
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(&param_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) {
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 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_kobject *mk, char *buf)
{
int count;
struct param_attribute *attribute = to_param_attr(mattr);
if (!attribute->param->ops->get)
return -EPERM;
mutex_lock(&param_lock);
count = attribute->param->ops->get(buf, attribute->param);
mutex_unlock(&param_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_kobject *km,
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(&param_lock);
err = attribute->param->ops->set(buf, attribute->param);
mutex_unlock(&param_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(&param_lock);
}
EXPORT_SYMBOL(__kernel_param_lock);
void __kernel_param_unlock(void)
{
mutex_unlock(&param_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 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,
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 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);
}
}
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 sprintf(buf, "%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 **p;
struct module_kobject *mk;
int err;
for (p = __start___modver; p < __stop___modver; p++) {
const struct module_version_attribute *vattr = *p;
mk = locate_module_kobject(vattr->module_name);
if (mk) {
err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
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(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;
version_sysfs_builtin();
param_sysfs_builtin();
return 0;
}
subsys_initcall(param_sysfs_init);
#endif /* CONFIG_SYSFS */
Jump to Line
Something went wrong with that request. Please try again.