tracepoint源码示例

#include <linux/proc_fs.h> #include <linux/netlink.h> #include <linux/module.h> #define CREATE_TRACE_POINTS #include "test_trace.h" #undef CREATE_TRACE_POINTS #define CDEVNAME "test" static int major; static struct class *dev_class; static ssize_t test_write(struct file *file, const char __user *buf, size_t count, loff_t *f_pos) { char test[128]; printk("test: cdev_write.\n"); if (copy_from_user(test, buf, count)) { goto exit; } else *f_pos += count; trace_test_trace(current); return count; exit: return -1; } static const struct file_operations test_fops = { .owner = THIS_MODULE, .write = test_write, }; static int test_init(void) { printk("test init.\n"); major = register_chrdev(0, CDEVNAME, &test_fops); if (major < 0) { pr_err("test: register_chrdev.\n"); return major; } dev_class = class_create(THIS_MODULE, "testclass"); if (IS_ERR(dev_class)) { unregister_chrdev(major, CDEVNAME); pr_err("test: class_create.\n"); return PTR_ERR(dev_class); } device_create(dev_class, NULL, MKDEV(major, 0), NULL, CDEVNAME); return 0; } static void test_exit(void) { printk("test exit.\n"); device_destroy(dev_class, MKDEV(major, 0)); class_destroy(dev_class); unregister_chrdev(major, CDEVNAME); } module_init(test_init); module_exit(test_exit); MODULE_LICENSE("GPL");