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-rw-r--r--kernel/params.c50
1 files changed, 31 insertions, 19 deletions
diff --git a/kernel/params.c b/kernel/params.c
index a8b09f6c87dc..8890d0b8dffc 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -25,15 +25,20 @@
#include <linux/slab.h>
#include <linux/ctype.h>
-/* Protects all parameters, and incidentally kmalloced_param list. */
+/* 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 */
+#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : &param_lock)
+#define KPARAM_IS_LOCKED(mod) mutex_is_locked(KPARAM_MUTEX(mod))
+
/* 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 +48,10 @@ 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 +60,7 @@ 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 +68,7 @@ static void maybe_kfree_parameter(void *param)
break;
}
}
+ spin_unlock(&kmalloced_params_lock);
}
static char dash2underscore(char c)
@@ -118,10 +128,10 @@ 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;
}
}
@@ -417,7 +427,8 @@ const 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,
@@ -448,7 +459,7 @@ 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));
+ BUG_ON(!KPARAM_IS_LOCKED(mod));
ret = set(val, &kp);
if (ret != 0)
@@ -470,7 +481,7 @@ 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);
}
@@ -485,7 +496,7 @@ static int param_array_get(char *buffer, const struct kernel_param *kp)
if (i)
buffer[off++] = ',';
p.arg = arr->elem + arr->elemsize * i;
- BUG_ON(!mutex_is_locked(&param_lock));
+ BUG_ON(!KPARAM_IS_LOCKED(p.mod));
ret = arr->ops->get(buffer + off, &p);
if (ret < 0)
return ret;
@@ -568,9 +579,9 @@ 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;
@@ -580,7 +591,7 @@ 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;
@@ -589,10 +600,10 @@ 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;
@@ -605,18 +616,19 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
#define __modinit __init
#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);
+
+#ifdef CONFIG_SYSFS
+EXPORT_SYMBOL(kernel_param_lock);
+EXPORT_SYMBOL(kernel_param_unlock);
/*
* add_sysfs_param - add a parameter to sysfs