12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394 |
- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright 2014 Google, Inc.
- */
- #include <linux/cdev.h>
- #include <linux/device.h>
- #include <linux/fs.h>
- #include <linux/uaccess.h>
- #include "internal.h"
- static DEFINE_MUTEX(pmsg_lock);
- static ssize_t write_pmsg(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
- {
- struct pstore_record record;
- int ret;
- if (!count)
- return 0;
- pstore_record_init(&record, psinfo);
- record.type = PSTORE_TYPE_PMSG;
- record.size = count;
- /* check outside lock, page in any data. write_user also checks */
- if (!access_ok(buf, count))
- return -EFAULT;
- mutex_lock(&pmsg_lock);
- ret = psinfo->write_user(&record, buf);
- mutex_unlock(&pmsg_lock);
- return ret ? ret : count;
- }
- static const struct file_operations pmsg_fops = {
- .owner = THIS_MODULE,
- .llseek = noop_llseek,
- .write = write_pmsg,
- };
- static struct class *pmsg_class;
- static int pmsg_major;
- #define PMSG_NAME "pmsg"
- #undef pr_fmt
- #define pr_fmt(fmt) PMSG_NAME ": " fmt
- static char *pmsg_devnode(struct device *dev, umode_t *mode)
- {
- if (mode)
- *mode = 0220;
- return NULL;
- }
- void pstore_register_pmsg(void)
- {
- struct device *pmsg_device;
- pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops);
- if (pmsg_major < 0) {
- pr_err("register_chrdev failed\n");
- goto err;
- }
- pmsg_class = class_create(THIS_MODULE, PMSG_NAME);
- if (IS_ERR(pmsg_class)) {
- pr_err("device class file already in use\n");
- goto err_class;
- }
- pmsg_class->devnode = pmsg_devnode;
- pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0),
- NULL, "%s%d", PMSG_NAME, 0);
- if (IS_ERR(pmsg_device)) {
- pr_err("failed to create device\n");
- goto err_device;
- }
- return;
- err_device:
- class_destroy(pmsg_class);
- err_class:
- unregister_chrdev(pmsg_major, PMSG_NAME);
- err:
- return;
- }
- void pstore_unregister_pmsg(void)
- {
- device_destroy(pmsg_class, MKDEV(pmsg_major, 0));
- class_destroy(pmsg_class);
- unregister_chrdev(pmsg_major, PMSG_NAME);
- }
|