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-rw-r--r--kernel/params.c127
1 files changed, 93 insertions, 34 deletions
diff --git a/kernel/params.c b/kernel/params.c
index a22d6a759..b6554aa71 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -25,15 +25,34 @@
#include <linux/slab.h>
#include <linux/ctype.h>
-/* Protects all parameters, and incidentally kmalloced_param list. */
+#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 : &param_lock)
+#else
+#define KPARAM_MUTEX(mod) (&param_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)
{
@@ -43,7 +62,10 @@ static void *kmalloc_parameter(unsigned int size)
if (!p)
return NULL;
+ spin_lock(&kmalloced_params_lock);
list_add(&p->list, &kmalloced_params);
+ spin_unlock(&kmalloced_params_lock);
+
return p->val;
}
@@ -52,6 +74,7 @@ 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);
@@ -59,6 +82,7 @@ static void maybe_kfree_parameter(void *param)
break;
}
}
+ spin_unlock(&kmalloced_params_lock);
}
static char dash2underscore(char c)
@@ -100,8 +124,9 @@ static int parse_one(char *param,
unsigned num_params,
s16 min_level,
s16 max_level,
+ void *arg,
int (*handle_unknown)(char *param, char *val,
- const char *doing))
+ const char *doing, void *arg))
{
unsigned int i;
int err;
@@ -118,17 +143,17 @@ static int parse_one(char *param,
return -EINVAL;
pr_debug("handling %s with %p\n", param,
params[i].ops->set);
- mutex_lock(&param_lock);
+ kernel_param_lock(params[i].mod);
param_check_unsafe(&params[i]);
err = params[i].ops->set(val, &params[i]);
- mutex_unlock(&param_lock);
+ 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);
+ return handle_unknown(param, val, doing, arg);
}
pr_debug("Unknown argument '%s'\n", param);
@@ -194,7 +219,9 @@ char *parse_args(const char *doing,
unsigned num,
s16 min_level,
s16 max_level,
- int (*unknown)(char *param, char *val, const char *doing))
+ void *arg,
+ int (*unknown)(char *param, char *val,
+ const char *doing, void *arg))
{
char *param, *val;
@@ -214,7 +241,7 @@ char *parse_args(const char *doing,
return args;
irq_was_disabled = irqs_disabled();
ret = parse_one(param, val, doing, params, num,
- min_level, max_level, unknown);
+ min_level, max_level, arg, unknown);
if (irq_was_disabled && !irqs_disabled())
pr_warn("%s: option '%s' enabled irq's!\n",
doing, param);
@@ -251,7 +278,7 @@ char *parse_args(const char *doing,
return scnprintf(buffer, PAGE_SIZE, format, \
*((type *)kp->arg)); \
} \
- struct kernel_param_ops param_ops_##name = { \
+ const struct kernel_param_ops param_ops_##name = { \
.set = param_set_##name, \
.get = param_get_##name, \
}; \
@@ -303,7 +330,7 @@ static void param_free_charp(void *arg)
maybe_kfree_parameter(*((char **)arg));
}
-struct kernel_param_ops param_ops_charp = {
+const struct kernel_param_ops param_ops_charp = {
.set = param_set_charp,
.get = param_get_charp,
.free = param_free_charp,
@@ -328,13 +355,44 @@ int param_get_bool(char *buffer, const struct kernel_param *kp)
}
EXPORT_SYMBOL(param_get_bool);
-struct kernel_param_ops param_ops_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 = 0;
+ 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)
{
@@ -356,7 +414,7 @@ int param_get_invbool(char *buffer, const struct kernel_param *kp)
}
EXPORT_SYMBOL(param_get_invbool);
-struct kernel_param_ops param_ops_invbool = {
+const struct kernel_param_ops param_ops_invbool = {
.set = param_set_invbool,
.get = param_get_invbool,
};
@@ -364,12 +422,11 @@ EXPORT_SYMBOL(param_ops_invbool);
int param_set_bint(const char *val, const struct kernel_param *kp)
{
- struct kernel_param boolkp;
+ /* Match bool exactly, by re-using it. */
+ struct kernel_param boolkp = *kp;
bool v;
int ret;
- /* Match bool exactly, by re-using it. */
- boolkp = *kp;
boolkp.arg = &v;
ret = param_set_bool(val, &boolkp);
@@ -379,7 +436,7 @@ int param_set_bint(const char *val, const struct kernel_param *kp)
}
EXPORT_SYMBOL(param_set_bint);
-struct kernel_param_ops param_ops_bint = {
+const struct kernel_param_ops param_ops_bint = {
.flags = KERNEL_PARAM_OPS_FL_NOARG,
.set = param_set_bint,
.get = param_get_int,
@@ -387,7 +444,8 @@ struct kernel_param_ops param_ops_bint = {
EXPORT_SYMBOL(param_ops_bint);
/* We break the rule and mangle the string. */
-static int param_array(const char *name,
+static int param_array(struct module *mod,
+ const char *name,
const char *val,
unsigned int min, unsigned int max,
void *elem, int elemsize,
@@ -418,7 +476,7 @@ 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));
+ check_kparam_locked(mod);
ret = set(val, &kp);
if (ret != 0)
@@ -440,7 +498,7 @@ 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,
+ return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
arr->elemsize, arr->ops->set, kp->level,
arr->num ?: &temp_num);
}
@@ -449,14 +507,13 @@ 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;
+ struct kernel_param p = *kp;
- 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));
+ check_kparam_locked(p.mod);
ret = arr->ops->get(buffer + off, &p);
if (ret < 0)
return ret;
@@ -476,7 +533,7 @@ static void param_array_free(void *arg)
arr->ops->free(arr->elem + arr->elemsize * i);
}
-struct kernel_param_ops param_array_ops = {
+const struct kernel_param_ops param_array_ops = {
.set = param_array_set,
.get = param_array_get,
.free = param_array_free,
@@ -504,7 +561,7 @@ int param_get_string(char *buffer, const struct kernel_param *kp)
}
EXPORT_SYMBOL(param_get_string);
-struct kernel_param_ops param_ops_string = {
+const struct kernel_param_ops param_ops_string = {
.set = param_set_copystring,
.get = param_get_string,
};
@@ -539,9 +596,9 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
if (!attribute->param->ops->get)
return -EPERM;
- mutex_lock(&param_lock);
+ kernel_param_lock(mk->mod);
count = attribute->param->ops->get(buf, attribute->param);
- mutex_unlock(&param_lock);
+ kernel_param_unlock(mk->mod);
if (count > 0) {
strcat(buf, "\n");
++count;
@@ -551,7 +608,7 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
/* 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,
+ struct module_kobject *mk,
const char *buf, size_t len)
{
int err;
@@ -560,10 +617,10 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
if (!attribute->param->ops->set)
return -EPERM;
- mutex_lock(&param_lock);
+ kernel_param_lock(mk->mod);
param_check_unsafe(attribute->param);
err = attribute->param->ops->set(buf, attribute->param);
- mutex_unlock(&param_lock);
+ kernel_param_unlock(mk->mod);
if (!err)
return len;
return err;
@@ -577,17 +634,18 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
#endif
#ifdef CONFIG_SYSFS
-void __kernel_param_lock(void)
+void kernel_param_lock(struct module *mod)
{
- mutex_lock(&param_lock);
+ mutex_lock(KPARAM_MUTEX(mod));
}
-EXPORT_SYMBOL(__kernel_param_lock);
-void __kernel_param_unlock(void)
+void kernel_param_unlock(struct module *mod)
{
- mutex_unlock(&param_lock);
+ mutex_unlock(KPARAM_MUTEX(mod));
}
-EXPORT_SYMBOL(__kernel_param_unlock);
+
+EXPORT_SYMBOL(kernel_param_lock);
+EXPORT_SYMBOL(kernel_param_unlock);
/*
* add_sysfs_param - add a parameter to sysfs
@@ -853,6 +911,7 @@ static void __init version_sysfs_builtin(void)
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);
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-11 17:15:14 +0000