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feat(lab03): ex 2 in one file

This commit is contained in:
2026-04-02 14:41:31 +02:00
parent beac78bf94
commit 9725e2c66b
2 changed files with 123 additions and 136 deletions

View File

@@ -1,133 +0,0 @@
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/cdev.h>
#include <linux/minmax.h>
#include <stddef.h>
#include <linux/uaccess.h>
// linux theory: https://linux-kernel-labs.github.io/refs/heads/master/labs/device_drivers.html
#define MY_MAJOR 42
#define MY_MAX_MINORS 5
#define BUFFER_SIZE 300
struct my_device_data {
struct cdev cdev;
/* my data starts here */
char buffer[BUFFER_SIZE];
};
struct my_device_data devs;
// inode: https://www.kernel.org/doc/html/latest/filesystems/ext4/inodes.html
// file: https://docs.kernel.org/filesystems/api-summary.html#c.file
int skeleton_open(struct inode* i, struct file* f) {
pr_info("Open file\n");
// Get the stuct of my data
struct my_device_data *my_data = container_of(i->i_cdev, struct my_device_data, cdev);
// point private data on driver data, here this is a char buffer
f->private_data = my_data;
return 0;
}
int skeleton_release(struct inode* i, struct file* f) {
pr_info("Release file\n");
return 0;
}
ssize_t skeleton_read(struct file* f, char* __user buf, size_t count, loff_t* off) {
pr_info("Read file\n");
struct my_device_data *my_data = (struct my_device_data *) f->private_data;
ssize_t len = min(BUFFER_SIZE - ((size_t)*off), count);
if (len <= 0) {
pr_info("Cannot read data for length: %ld\n", len);
return 0;
}
/* read data from my_data->buffer to user buffer */
if (copy_to_user(buf, my_data->buffer + *off, len)) {
pr_info("Failed to copy to user space buffer\n");
return -EFAULT;
}
*off += len;
return len;
}
ssize_t skeleton_write(struct file* f, const char* __user buf, size_t count, loff_t* off) {
pr_info("Write file\n");
struct my_device_data *my_data = (struct my_device_data *) f->private_data;
ssize_t len = min(BUFFER_SIZE - ((size_t)*off), count);
if (len <= 0) {
pr_info("Cannot write data for length: %ld\n", len);
return 0;
}
/* read data from user buffer to my_data->buffer */
if (copy_from_user(my_data->buffer + *off, buf, len)) {
pr_info("Failed to copy from user space buffer\n");
return -EFAULT;
}
*off += len;
return len;
}
static struct file_operations skeleton_fops = {
.owner = THIS_MODULE,
.open = skeleton_open,
.read = skeleton_read,
.write = skeleton_write,
.release = skeleton_release,
};
int ex2_init(void) {
pr_info("Load exercice 2\n");
int ret = register_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS, "My module");
if (ret != 0) {
/* report error */
pr_info("Module registration error: %d\n", ret);
return ret;
}
/* initialize devs fields */
cdev_init(&devs.cdev, &skeleton_fops);
ret = cdev_add(&devs.cdev, MKDEV(MY_MAJOR, 0), 1);
if (ret != 0) {
/* report error */
pr_info("cdev add error: %d\n", ret);
return ret;
}
return ret;
}
void ex2_exit(void) {
cdev_del(&devs.cdev);
unregister_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS);
}

View File

@@ -1,17 +1,136 @@
#include <linux/module.h> // needed by all modules
#include <linux/init.h> // needed for macros
#include <linux/kernel.h> // needed for debugging
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/cdev.h>
#include <linux/minmax.h>
#include <stddef.h>
#include <linux/uaccess.h>
#include "ex2.c"
// linux theory: https://linux-kernel-labs.github.io/refs/heads/master/labs/device_drivers.html
#define MY_MAJOR 42
#define MY_MAX_MINORS 5
#define BUFFER_SIZE 300
struct my_device_data {
struct cdev cdev;
/* my data starts here */
char buffer[BUFFER_SIZE];
};
struct my_device_data devs;
// inode: https://www.kernel.org/doc/html/latest/filesystems/ext4/inodes.html
// file: https://docs.kernel.org/filesystems/api-summary.html#c.file
int skeleton_open(struct inode* i, struct file* f) {
pr_info("Open file\n");
// Get the stuct of my data
struct my_device_data *my_data = container_of(i->i_cdev, struct my_device_data, cdev);
// point private data on driver data, here this is a char buffer
f->private_data = my_data;
return 0;
}
int skeleton_release(struct inode* i, struct file* f) {
pr_info("Release file\n");
return 0;
}
ssize_t skeleton_read(struct file* f, char* __user buf, size_t count, loff_t* off) {
pr_info("Read file\n");
struct my_device_data *my_data = (struct my_device_data *) f->private_data;
ssize_t len = min(BUFFER_SIZE - ((size_t)*off), count);
if (len <= 0) {
pr_info("Cannot read data for length: %ld\n", len);
return 0;
}
/* read data from my_data->buffer to user buffer */
if (copy_to_user(buf, my_data->buffer + *off, len)) {
pr_info("Failed to copy to user space buffer\n");
return -EFAULT;
}
*off += len;
return len;
}
ssize_t skeleton_write(struct file* f, const char* __user buf, size_t count, loff_t* off) {
pr_info("Write file\n");
struct my_device_data *my_data = (struct my_device_data *) f->private_data;
ssize_t len = min(BUFFER_SIZE - ((size_t)*off), count);
if (len <= 0) {
pr_info("Cannot write data for length: %ld\n", len);
return 0;
}
/* read data from user buffer to my_data->buffer */
if (copy_from_user(my_data->buffer + *off, buf, len)) {
pr_info("Failed to copy from user space buffer\n");
return -EFAULT;
}
*off += len;
return len;
}
static struct file_operations skeleton_fops = {
.owner = THIS_MODULE,
.open = skeleton_open,
.read = skeleton_read,
.write = skeleton_write,
.release = skeleton_release,
};
static int __init skeleton_init(void) {
int ret = 0;
pr_info("My module loading...\n");
pr_info("----------------------\n");
ret = ex2_init();
pr_info("Load exercice 2\n");
ret = register_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS, "My module");
if (ret != 0) {
/* report error */
pr_info("Module registration error: %d\n", ret);
return ret;
}
/* initialize devs fields */
cdev_init(&devs.cdev, &skeleton_fops);
ret = cdev_add(&devs.cdev, MKDEV(MY_MAJOR, 0), 1);
if (ret != 0) {
/* report error */
pr_info("cdev add error: %d\n", ret);
return ret;
}
pr_info("----------------------\n");
pr_info("My module is loaded\n");
@@ -23,7 +142,8 @@ static void __exit skeleton_exit(void) {
pr_info("My module unloading...\n");
pr_info("----------------------\n");
ex2_exit();
cdev_del(&devs.cdev);
unregister_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS);
pr_info("----------------------\n");
pr_info("My module is unloaded\n");