这是将数据传输到“param_buf”字符串的源代码。按照要求,没有读取方法。仅限商店。
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/string.h>
static struct kobject *register_kobj;
static char *param_buf;
// function for many symbol data enter
static ssize_t __used store_value(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count){
printk(KERN_ALERT "you entered %s\n", buf);
strncpy(param_buf, buf, PAGE_SIZE - 1);
return count;
}
// register function to attribute
static struct kobj_attribute store_val_attribute = __ATTR( put_parameters, 0220, NULL, store_value);
// put attribute to attribute group
static struct attribute *register_attrs[] = {
&store_val_attribute.attr,
NULL, /* NULL terminate the list*/
};
static struct attribute_group reg_attr_group = {
.attrs = register_attrs
};
static int hello_init(void){
param_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
// create sysfs object ( /sys/kernel/test_1025_sym directory )
register_kobj = kobject_create_and_add("test_1025_sym", kernel_kobj);
if (!register_kobj)
return -ENOMEM;
//create attributes (files)
if(sysfs_create_group(register_kobj, ®_attr_group)){
kobject_put(register_kobj);
return -ENOMEM;
}
return 0;
}
static void hello_exit(void){
printk(KERN_ALERT "last value was %s\n", param_buf);
kfree(param_buf);
kobject_put(register_kobj);
}
MODULE_LICENSE("Dual BSD/GPL");
module_init(hello_init);
module_exit(hello_exit);
你可以用这样的方式测试它:
cat /etc/fstab > /sys/kernel/test_1025_sym/put_parameters
对于两个字符串条目:复制一个 store_value 函数,再注册一个 store_val_attribute 并将其放入属性列表中。