70 lines
1.6 KiB
C
70 lines
1.6 KiB
C
/*
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* procfs1.c
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/proc_fs.h>
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#include <linux/uaccess.h>
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#include <linux/version.h>
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
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#define HAVE_PROC_OPS
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#endif
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#define procfs_name "helloworld"
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static struct proc_dir_entry *our_proc_file;
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static ssize_t procfile_read(struct file *file_pointer, char __user *buffer,
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size_t buffer_length, loff_t *offset)
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{
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char s[13] = "HelloWorld!\n";
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int len = sizeof(s);
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ssize_t ret = len;
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/* 如果偏移量大于或等于字符串长度，或者 copy_to_user 失败，则读取操作失败，返回 0。 */
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if (*offset >= len || copy_to_user(buffer, s, len)) {
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pr_info("copy_to_user 执行结束 \n");
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ret = 0;
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} else {
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pr_info("读取项目文件: %s\n", file_pointer->f_path.dentry->d_name.name);
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*offset += len;
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}
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return ret;
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}
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#ifdef HAVE_PROC_OPS
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static const struct proc_ops proc_file_fops = {
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.proc_read = procfile_read,
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};
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#else
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static const struct file_operations proc_file_fops = {
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.read = procfile_read,
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};
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#endif
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static int __init procfs1_init(void)
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{
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our_proc_file = proc_create(procfs_name, 0644, NULL, &proc_file_fops);
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if (NULL == our_proc_file) {
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proc_remove(our_proc_file);
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pr_alert("错误: 无法初始化 /proc/%s\n", procfs_name);
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return -ENOMEM;
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}
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pr_info("/proc/%s 已创建\n", procfs_name);
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return 0;
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}
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static void __exit procfs1_exit(void)
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{
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proc_remove(our_proc_file);
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pr_info("/proc/%s 已卸载\n", procfs_name);
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}
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module_init(procfs1_init);
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module_exit(procfs1_exit);
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MODULE_LICENSE("GPL");
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