118 lines
2.8 KiB
C
Executable File
118 lines
2.8 KiB
C
Executable File
/*
|
|
* This module provides an interface to trigger and test firmware loading.
|
|
*
|
|
* It is designed to be used for basic evaluation of the firmware loading
|
|
* subsystem (for example when validating firmware verification). It lacks
|
|
* any extra dependencies, and will not normally be loaded by the system
|
|
* unless explicitly requested by name.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/firmware.h>
|
|
#include <linux/device.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
static DEFINE_MUTEX(test_fw_mutex);
|
|
static const struct firmware *test_firmware;
|
|
|
|
static ssize_t test_fw_misc_read(struct file *f, char __user *buf,
|
|
size_t size, loff_t *offset)
|
|
{
|
|
ssize_t rc = 0;
|
|
|
|
mutex_lock(&test_fw_mutex);
|
|
if (test_firmware)
|
|
rc = simple_read_from_buffer(buf, size, offset,
|
|
test_firmware->data,
|
|
test_firmware->size);
|
|
mutex_unlock(&test_fw_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static const struct file_operations test_fw_fops = {
|
|
.owner = THIS_MODULE,
|
|
.read = test_fw_misc_read,
|
|
};
|
|
|
|
static struct miscdevice test_fw_misc_device = {
|
|
.minor = MISC_DYNAMIC_MINOR,
|
|
.name = "test_firmware",
|
|
.fops = &test_fw_fops,
|
|
};
|
|
|
|
static ssize_t trigger_request_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int rc;
|
|
char *name;
|
|
|
|
name = kzalloc(count + 1, GFP_KERNEL);
|
|
if (!name)
|
|
return -ENOSPC;
|
|
memcpy(name, buf, count);
|
|
|
|
pr_info("loading '%s'\n", name);
|
|
|
|
mutex_lock(&test_fw_mutex);
|
|
release_firmware(test_firmware);
|
|
test_firmware = NULL;
|
|
rc = request_firmware(&test_firmware, name, dev);
|
|
if (rc)
|
|
pr_info("load of '%s' failed: %d\n", name, rc);
|
|
pr_info("loaded: %zu\n", test_firmware ? test_firmware->size : 0);
|
|
mutex_unlock(&test_fw_mutex);
|
|
|
|
kfree(name);
|
|
|
|
return count;
|
|
}
|
|
static DEVICE_ATTR_WO(trigger_request);
|
|
|
|
static int __init test_firmware_init(void)
|
|
{
|
|
int rc;
|
|
|
|
rc = misc_register(&test_fw_misc_device);
|
|
if (rc) {
|
|
pr_err("could not register misc device: %d\n", rc);
|
|
return rc;
|
|
}
|
|
rc = device_create_file(test_fw_misc_device.this_device,
|
|
&dev_attr_trigger_request);
|
|
if (rc) {
|
|
pr_err("could not create sysfs interface: %d\n", rc);
|
|
goto dereg;
|
|
}
|
|
|
|
pr_warn("interface ready\n");
|
|
|
|
return 0;
|
|
dereg:
|
|
misc_deregister(&test_fw_misc_device);
|
|
return rc;
|
|
}
|
|
|
|
module_init(test_firmware_init);
|
|
|
|
static void __exit test_firmware_exit(void)
|
|
{
|
|
release_firmware(test_firmware);
|
|
device_remove_file(test_fw_misc_device.this_device,
|
|
&dev_attr_trigger_request);
|
|
misc_deregister(&test_fw_misc_device);
|
|
pr_warn("removed interface\n");
|
|
}
|
|
|
|
module_exit(test_firmware_exit);
|
|
|
|
MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
|
|
MODULE_LICENSE("GPL");
|