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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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