nhmk/examples/procfs1.c
2021-07-22 06:35:24 +08:00

52 lines
1.1 KiB
C

/*
procfs1.c
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/uaccess.h>
#define procfs_name "helloworld"
struct proc_dir_entry *Our_Proc_File;
ssize_t procfile_read(struct file *filePointer,char *buffer,
size_t buffer_length, loff_t * offset)
{
int ret=0;
if(strlen(buffer) ==0) {
pr_info("procfile read %s\n",filePointer->f_path.dentry->d_name.name);
ret=copy_to_user(buffer,"HelloWorld!\n",sizeof("HelloWorld!\n"));
ret=sizeof("HelloWorld!\n");
}
return ret;
}
static const struct proc_ops proc_file_fops = {
.proc_read = procfile_read,
};
int init_module()
{
Our_Proc_File = proc_create(procfs_name,0644,NULL,&proc_file_fops);
if(NULL==Our_Proc_File) {
proc_remove(Our_Proc_File);
pr_alert("Error:Could not initialize /proc/%s\n",procfs_name);
return -ENOMEM;
}
pr_info("/proc/%s created\n", procfs_name);
return 0;
}
void cleanup_module()
{
proc_remove(Our_Proc_File);
pr_info("/proc/%s removed\n", procfs_name);
}
MODULE_LICENSE("GPL");