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Diffstat (limited to 'kernel/params.c')
-rw-r--r--kernel/params.c233
1 files changed, 161 insertions, 72 deletions
diff --git a/kernel/params.c b/kernel/params.c
index 0b30ecd53a52..08107d181758 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -31,6 +31,42 @@
#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 == '-')
@@ -49,18 +85,25 @@ static inline int parameq(const char *input, const char *paramname)
static int parse_one(char *param,
char *val,
- struct kernel_param *params,
+ 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].set);
- return params[i].set(val, &params[i]);
+ params[i].ops->set);
+ mutex_lock(&param_lock);
+ err = params[i].ops->set(val, &params[i]);
+ mutex_unlock(&param_lock);
+ return err;
}
}
@@ -128,7 +171,7 @@ static char *next_arg(char *args, char **param, char **val)
/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
int parse_args(const char *name,
char *args,
- struct kernel_param *params,
+ const struct kernel_param *params,
unsigned num,
int (*unknown)(char *param, char *val))
{
@@ -176,22 +219,29 @@ int parse_args(const char *name,
/* Lazy bastard, eh? */
#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
- int param_set_##name(const char *val, struct kernel_param *kp) \
+ int param_set_##name(const char *val, const struct kernel_param *kp) \
{ \
tmptype l; \
int ret; \
\
- if (!val) return -EINVAL; \
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, struct kernel_param *kp) \
+ 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);
@@ -201,39 +251,50 @@ 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, struct kernel_param *kp)
+int param_set_charp(const char *val, const struct kernel_param *kp)
{
- if (!val) {
- printk(KERN_ERR "%s: string parameter expected\n",
- kp->name);
- return -EINVAL;
- }
-
if (strlen(val) > 1024) {
printk(KERN_ERR "%s: string parameter too long\n",
kp->name);
return -ENOSPC;
}
- /* This is a hack. We can't need to strdup in early boot, and we
+ 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 = kstrdup(val, GFP_KERNEL);
+ *(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, struct kernel_param *kp)
+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, struct kernel_param *kp)
+int param_set_bool(const char *val, const struct kernel_param *kp)
{
bool v;
@@ -258,8 +319,9 @@ int param_set_bool(const char *val, struct kernel_param *kp)
*(int *)kp->arg = v;
return 0;
}
+EXPORT_SYMBOL(param_set_bool);
-int param_get_bool(char *buffer, struct kernel_param *kp)
+int param_get_bool(char *buffer, const struct kernel_param *kp)
{
bool val;
if (kp->flags & KPARAM_ISBOOL)
@@ -270,9 +332,16 @@ int param_get_bool(char *buffer, struct kernel_param *kp)
/* 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, struct kernel_param *kp)
+int param_set_invbool(const char *val, const struct kernel_param *kp)
{
int ret;
bool boolval;
@@ -285,18 +354,26 @@ int param_set_invbool(const char *val, struct kernel_param *kp)
*(bool *)kp->arg = !boolval;
return ret;
}
+EXPORT_SYMBOL(param_set_invbool);
-int param_get_invbool(char *buffer, struct kernel_param *kp)
+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 *, struct kernel_param *kp),
+ int (*set)(const char *, const struct kernel_param *kp),
u16 flags,
unsigned int *num)
{
@@ -309,12 +386,6 @@ static int param_array(const char *name,
kp.arg = elem;
kp.flags = flags;
- /* No equals sign? */
- if (!val) {
- printk(KERN_ERR "%s: expects arguments\n", name);
- return -EINVAL;
- }
-
*num = 0;
/* We expect a comma-separated list of values. */
do {
@@ -330,6 +401,7 @@ static int param_array(const char *name,
/* 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)
@@ -347,17 +419,17 @@ static int param_array(const char *name,
return 0;
}
-int param_array_set(const char *val, struct kernel_param *kp)
+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->set, kp->flags,
+ arr->elemsize, arr->ops->set, kp->flags,
arr->num ?: &temp_num);
}
-int param_array_get(char *buffer, struct kernel_param *kp)
+static int param_array_get(char *buffer, const struct kernel_param *kp)
{
int i, off, ret;
const struct kparam_array *arr = kp->arr;
@@ -368,7 +440,8 @@ int param_array_get(char *buffer, struct kernel_param *kp)
if (i)
buffer[off++] = ',';
p.arg = arr->elem + arr->elemsize * i;
- ret = arr->get(buffer + off, &p);
+ BUG_ON(!mutex_is_locked(&param_lock));
+ ret = arr->ops->get(buffer + off, &p);
if (ret < 0)
return ret;
off += ret;
@@ -377,14 +450,27 @@ int param_array_get(char *buffer, struct kernel_param *kp)
return off;
}
-int param_set_copystring(const char *val, struct kernel_param *kp)
+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 (!val) {
- printk(KERN_ERR "%s: missing param set value\n", kp->name);
- return -EINVAL;
- }
if (strlen(val)+1 > kps->maxlen) {
printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
kp->name, kps->maxlen-1);
@@ -393,12 +479,20 @@ int param_set_copystring(const char *val, struct kernel_param *kp)
strcpy(kps->string, val);
return 0;
}
+EXPORT_SYMBOL(param_set_copystring);
-int param_get_string(char *buffer, struct kernel_param *kp)
+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)
@@ -409,7 +503,7 @@ extern struct kernel_param __start___param[], __stop___param[];
struct param_attribute
{
struct module_attribute mattr;
- struct kernel_param *param;
+ const struct kernel_param *param;
};
struct module_param_attrs
@@ -428,10 +522,12 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
int count;
struct param_attribute *attribute = to_param_attr(mattr);
- if (!attribute->param->get)
+ if (!attribute->param->ops->get)
return -EPERM;
- count = attribute->param->get(buf, attribute->param);
+ mutex_lock(&param_lock);
+ count = attribute->param->ops->get(buf, attribute->param);
+ mutex_unlock(&param_lock);
if (count > 0) {
strcat(buf, "\n");
++count;
@@ -447,10 +543,12 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
int err;
struct param_attribute *attribute = to_param_attr(mattr);
- if (!attribute->param->set)
+ if (!attribute->param->ops->set)
return -EPERM;
- err = attribute->param->set(buf, attribute->param);
+ mutex_lock(&param_lock);
+ err = attribute->param->ops->set(buf, attribute->param);
+ mutex_unlock(&param_lock);
if (!err)
return len;
return err;
@@ -464,6 +562,18 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
#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
@@ -475,7 +585,7 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
* if there's an error.
*/
static __modinit int add_sysfs_param(struct module_kobject *mk,
- struct kernel_param *kp,
+ const struct kernel_param *kp,
const char *name)
{
struct module_param_attrs *new;
@@ -557,7 +667,7 @@ static void free_module_param_attrs(struct module_kobject *mk)
* /sys/module/[mod->name]/parameters/
*/
int module_param_sysfs_setup(struct module *mod,
- struct kernel_param *kparam,
+ const struct kernel_param *kparam,
unsigned int num_params)
{
int i, err;
@@ -602,7 +712,11 @@ void module_param_sysfs_remove(struct module *mod)
void destroy_params(const struct kernel_param *params, unsigned num)
{
- /* FIXME: This should free kmalloced charp parameters. It doesn't. */
+ 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,
@@ -768,28 +882,3 @@ static int __init param_sysfs_init(void)
subsys_initcall(param_sysfs_init);
#endif /* CONFIG_SYSFS */
-
-EXPORT_SYMBOL(param_set_byte);
-EXPORT_SYMBOL(param_get_byte);
-EXPORT_SYMBOL(param_set_short);
-EXPORT_SYMBOL(param_get_short);
-EXPORT_SYMBOL(param_set_ushort);
-EXPORT_SYMBOL(param_get_ushort);
-EXPORT_SYMBOL(param_set_int);
-EXPORT_SYMBOL(param_get_int);
-EXPORT_SYMBOL(param_set_uint);
-EXPORT_SYMBOL(param_get_uint);
-EXPORT_SYMBOL(param_set_long);
-EXPORT_SYMBOL(param_get_long);
-EXPORT_SYMBOL(param_set_ulong);
-EXPORT_SYMBOL(param_get_ulong);
-EXPORT_SYMBOL(param_set_charp);
-EXPORT_SYMBOL(param_get_charp);
-EXPORT_SYMBOL(param_set_bool);
-EXPORT_SYMBOL(param_get_bool);
-EXPORT_SYMBOL(param_set_invbool);
-EXPORT_SYMBOL(param_get_invbool);
-EXPORT_SYMBOL(param_array_set);
-EXPORT_SYMBOL(param_array_get);
-EXPORT_SYMBOL(param_set_copystring);
-EXPORT_SYMBOL(param_get_string);