linux/lib/test_firmware.c
Brian Norris 47e0bbb7fa test: firmware_class: report errors properly on failure
request_firmware() failures currently won't get reported at all (the
error code is discarded). What's more, we get confusing messages, like:

    # echo -n notafile > /sys/devices/virtual/misc/test_firmware/trigger_request
    [ 8280.311856] test_firmware: loading 'notafile'
    [ 8280.317042] test_firmware: load of 'notafile' failed: -2
    [ 8280.322445] test_firmware: loaded: 0
    # echo $?
    0

Report the failures via write() errors, and don't say we "loaded"
anything.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2016-01-07 13:41:22 -07:00

123 lines
2.8 KiB
C

/*
* 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);
goto out;
}
pr_info("loaded: %zu\n", test_firmware->size);
rc = count;
out:
mutex_unlock(&test_fw_mutex);
kfree(name);
return rc;
}
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");