//DebugFS： //默认情况下，debugfs会被挂载在目录/sys/kernel/debug//手动挂载，mount -t debugfs none /your/debugfs/dir//创建目录/文件：struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);struct dentry *debugfs_create_file(const char *name, mode_t mode, struct dentry *parent, void *data, const struct file_operations *fops);//删除目录/文件void debugfs_remove(struct dentry *dentry);//删除目录下所有dentryvoid debugfs_remove_recursive(struct dentry *dentry);//创建单值对象：struct dentry *debugfs_create_u8(const char *name, mode_t mode, struct dentry *parent, u8 *value);struct dentry *debugfs_create_u16(const char *name, mode_t mode, struct dentry *parent, u16 *value);struct dentry *debugfs_create_u32(const char *name, mode_t mode, struct dentry *parent, u32 *value);struct dentry *debugfs_create_u64(const char *name, mode_t mode, struct dentry *parent, u64 *value); struct dentry *debugfs_create_x8(const char *name, mode_t mode, struct dentry *parent, u8 *value);struct dentry *debugfs_create_x16(const char *name, mode_t mode, struct dentry *parent, u16 *value);struct dentry *debugfs_create_x32(const char *name, mode_t mode, struct dentry *parent, u32 *value); struct dentry *debugfs_create_size_t(const char *name, mode_t mode, struct dentry *parent, size_t *value);struct dentry *debugfs_create_bool(const char *name, mode_t mode, struct dentry *parent, u32 *value);//创建二进制对象：struct debugfs_blob_wrapper { void *data; unsigned long size;};struct dentry *debugfs_create_blob(const char *name, mode_t mode, struct dentry *parent, struct debugfs_blob_wrapper *blob);//其他：struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, struct dentry *new_dir, const char *new_name); struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, const char *target);//简单封装debugfs,实现对内核缓存区的读访问，方便调试驱动观察缓存区：#include <linux/module.h>#include <linux/init.h>#include <linux/fs.h>#include <linux/debugfs.h> struct debug_struct{void *buffer;int buffer_len;struct dentry *file;};static int debug_open(struct inode *inode, struct file *filp){ filp->private_data = inode->i_private; return 0;}static ssize_t debug_read(struct file *fp, char __user *user_buffer, size_t count, loff_t *position) { struct debug_struct *s = (struct debug_struct *)fp->private_data; return simple_read_from_buffer(user_buffer, count, position, s->buffer, s->buffer_len);} const struct file_operations debug_fops = { .read = debug_read, .open = debug_open, }; static int debug_create_file(struct dentry *dir, struct debug_struct *st, const char *name){if(!st)return -EINVAL;st->file = debugfs_create_file(name, 0644, dir, st, &debug_fops);if(!st->file)return -ENODEV;return 0;}static int debug_remove_file(struct debug_struct *st){if(!st)return -EINVAL;debugfs_remove(st->file);st->file = NULL;return 0;}//测试：//1.创建核心内存mem//2.通过debugfs，创建mem的文件#define BUFFER_SIZE1024struct debug_struct *st;struct dentry *dir;static void debug_init(void){int ret = 0;st = (struct debug_struct *)kmalloc(sizeof(struct debug_struct), GFP_KERNEL);if(!st){printk(KERN_ALERT "debug test: kmalloc debug_struct failed.\n");goto err_kmalloc_st;}st->buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);if(!st->buffer){printk(KERN_ALERT "debug test: kmalloc buffer failed.\n");goto err_kmalloc_buff;}st->buffer_len = BUFFER_SIZE;dir = debugfs_create_dir("debug_dir", NULL);if(!dir){printk(KERN_ALERT "debug test: debugfs_create_dir failed.\n");goto err_create_dir;}ret = debug_create_file(dir, st, "debug_mem");if(ret){printk(KERN_ALERT "debug test: debug_create_file failed.\n");goto err_create_file;}//now you can see debug_dir in /sys/kernel/debug/return;err_create_file:debugfs_remove_recursive(dir);err_create_dir:kfree((void *)st->buffer);err_kmalloc_buff:kfree((void *)st);err_kmalloc_st:return;}static void debug_uinit(void){int ret = 0;debug_remove_file(st);debugfs_remove_recursive(dir);kfree((void *)st->buffer);kfree((void *)st);return;}//参考：//http://www.linuxforu.com/2010/10/debugging-linux-kernel-with-debugfs///http://www.cnblogs.com/wwang/archive/2011/01/17/1937609.html
