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#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include "mod.h"
#include "dev.h"
#include "debug.h"
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Suren A. Chilingaryan <csa@suren.me>");
MODULE_DESCRIPTION("Kernel Memory Manager - a module to manipulate kernel memory");
MODULE_VERSION("0.0.1");
int kmm_minors = KMM_MINORS;
module_param(kmm_minors, int, S_IRUGO);
static dev_t kmm_devno; /**< major number */
static kmm_dev_t **kmm_devs = NULL; /**< per-device context */
static spinlock_t kmm_devs_lock; /**< lock protecting creation/destruction of devices */
static struct class *kmm_class; /**< device class */
static void kmm_module_cleanup(void)
{
int i;
if (kmm_devs) {
for (i = 0; i < kmm_minors; i++) {
if (kmm_devs[i]) {
if (kmm_devs[i]->dev)
device_destroy(kmm_class, kmm_devs[i]->devno);
cdev_del(&kmm_devs[i]->cdev);
kfree(kmm_devs[i]);
}
}
kfree(kmm_devs);
}
if (kmm_class)
class_destroy(kmm_class);
unregister_chrdev_region(kmm_devno, kmm_minors);
}
static int kmm_module_setup_cdev(void)
{
int i;
int err = 0;
dev_t devno;
kmm_dev_t *dev;
dev = kmalloc(sizeof(kmm_dev_t), GFP_KERNEL);
if (!dev) {
mod_info("Couldn't allocate memory. Device is not created.\n");
return -ENOMEM;
}
cdev_init(&dev->cdev, kmm_get_fops());
dev->cdev.owner = THIS_MODULE;
dev->cdev.ops = kmm_get_fops();
spin_lock(&kmm_devs_lock);
for (i = 0; i < kmm_minors; i++) {
if (!kmm_devs[i])
break;
}
if (i == kmm_minors) {
mod_info("No free minor numbers left");
err = -EBUSY;
goto fail;
}
devno = MKDEV(MAJOR(kmm_devno), MINOR(kmm_devno) + i);
dev->devno = devno;
err = cdev_add(&dev->cdev, devno, 1);
if (err) {
mod_info("Error %d adding device kmm%d", err, i);
goto fail;
}
dev->dev = device_create(kmm_class, NULL, devno, dev, KMM_NODE_FMT, MINOR(kmm_devno) + i);
if (!dev->dev) {
mod_info("Error creating /dev/%s%d\n", KMM_NODE, MINOR(kmm_devno) + i);
goto fail;
}
dev_set_drvdata(dev->dev, dev);
kmm_devs[i] = dev;
spin_unlock(&kmm_devs_lock);
mod_info("Device /dev/%s%d added\n", KMM_NODE, MINOR(kmm_devno) + i);
return 0;
fail:
spin_unlock(&kmm_devs_lock);
kfree(dev);
return err;
}
static int __init kmm_module_init(void)
{
int err;
spin_lock_init(&kmm_devs_lock);
if ((err = alloc_chrdev_region(&kmm_devno, 0, kmm_minors, KMM_NODE))) {
mod_info("Couldn't allocate chrdev region. Module not loaded.\n");
goto alloc_chrdev_fail;
}
kmm_class = class_create(THIS_MODULE, KMM_NODE);
if (IS_ERR(kmm_class)) {
mod_info("No sysfs support. Module not loaded.\n");
goto fail;
}
kmm_devs = kmalloc(kmm_minors * sizeof(kmm_dev_t*), GFP_KERNEL);
if (!kmm_devs) {
mod_info("Couldn't allocate memory. Module not loaded.\n");
err = -ENOMEM;
}
memset(kmm_devs, 0, kmm_minors * sizeof(kmm_dev_t*));
mod_info("Major %d allocated to node '%s'\n", MAJOR(kmm_devno), KMM_NODE);
err = kmm_module_setup_cdev();
if (err) goto fail;
return 0;
fail:
kmm_module_cleanup();
alloc_chrdev_fail:
return err;
}
static void __exit kmm_module_exit(void)
{
kmm_module_cleanup();
}
module_init(kmm_module_init);
module_exit(kmm_module_exit);
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