linux/lib/test_firmware.c

921 lines
22 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/completion.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>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>
#define TEST_FIRMWARE_NAME "test-firmware.bin"
#define TEST_FIRMWARE_NUM_REQS 4
static DEFINE_MUTEX(test_fw_mutex);
static const struct firmware *test_firmware;
struct test_batched_req {
u8 idx;
int rc;
bool sent;
const struct firmware *fw;
const char *name;
struct completion completion;
struct task_struct *task;
struct device *dev;
};
/**
* test_config - represents configuration for the test for different triggers
*
* @name: the name of the firmware file to look for
* @sync_direct: when the sync trigger is used if this is true
* request_firmware_direct() will be used instead.
* @send_uevent: whether or not to send a uevent for async requests
* @num_requests: number of requests to try per test case. This is trigger
* specific.
* @reqs: stores all requests information
* @read_fw_idx: index of thread from which we want to read firmware results
* from through the read_fw trigger.
* @test_result: a test may use this to collect the result from the call
* of the request_firmware*() calls used in their tests. In order of
* priority we always keep first any setup error. If no setup errors were
* found then we move on to the first error encountered while running the
* API. Note that for async calls this typically will be a successful
* result (0) unless of course you've used bogus parameters, or the system
* is out of memory. In the async case the callback is expected to do a
* bit more homework to figure out what happened, unfortunately the only
* information passed today on error is the fact that no firmware was
* found so we can only assume -ENOENT on async calls if the firmware is
* NULL.
*
* Errors you can expect:
*
* API specific:
*
* 0: success for sync, for async it means request was sent
* -EINVAL: invalid parameters or request
* -ENOENT: files not found
*
* System environment:
*
* -ENOMEM: memory pressure on system
* -ENODEV: out of number of devices to test
* -EINVAL: an unexpected error has occurred
* @req_firmware: if @sync_direct is true this is set to
* request_firmware_direct(), otherwise request_firmware()
*/
struct test_config {
char *name;
bool sync_direct;
bool send_uevent;
u8 num_requests;
u8 read_fw_idx;
/*
* These below don't belong her but we'll move them once we create
* a struct fw_test_device and stuff the misc_dev under there later.
*/
struct test_batched_req *reqs;
int test_result;
int (*req_firmware)(const struct firmware **fw, const char *name,
struct device *device);
};
static struct test_config *test_fw_config;
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 void __test_release_all_firmware(void)
{
struct test_batched_req *req;
u8 i;
if (!test_fw_config->reqs)
return;
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
if (req->fw)
release_firmware(req->fw);
}
vfree(test_fw_config->reqs);
test_fw_config->reqs = NULL;
}
static void test_release_all_firmware(void)
{
mutex_lock(&test_fw_mutex);
__test_release_all_firmware();
mutex_unlock(&test_fw_mutex);
}
static void __test_firmware_config_free(void)
{
__test_release_all_firmware();
kfree_const(test_fw_config->name);
test_fw_config->name = NULL;
}
/*
* XXX: move to kstrncpy() once merged.
*
* Users should use kfree_const() when freeing these.
*/
static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
{
*dst = kstrndup(name, count, gfp);
if (!*dst)
return -ENOSPC;
return count;
}
static int __test_firmware_config_init(void)
{
int ret;
ret = __kstrncpy(&test_fw_config->name, TEST_FIRMWARE_NAME,
strlen(TEST_FIRMWARE_NAME), GFP_KERNEL);
if (ret < 0)
goto out;
test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
test_fw_config->send_uevent = true;
test_fw_config->sync_direct = false;
test_fw_config->req_firmware = request_firmware;
test_fw_config->test_result = 0;
test_fw_config->reqs = NULL;
return 0;
out:
__test_firmware_config_free();
return ret;
}
static ssize_t reset_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
mutex_lock(&test_fw_mutex);
__test_firmware_config_free();
ret = __test_firmware_config_init();
if (ret < 0) {
ret = -ENOMEM;
pr_err("could not alloc settings for config trigger: %d\n",
ret);
goto out;
}
pr_info("reset\n");
ret = count;
out:
mutex_unlock(&test_fw_mutex);
return ret;
}
static DEVICE_ATTR_WO(reset);
static ssize_t config_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int len = 0;
mutex_lock(&test_fw_mutex);
len += snprintf(buf, PAGE_SIZE,
"Custom trigger configuration for: %s\n",
dev_name(dev));
if (test_fw_config->name)
len += snprintf(buf+len, PAGE_SIZE,
"name:\t%s\n",
test_fw_config->name);
else
len += snprintf(buf+len, PAGE_SIZE,
"name:\tEMTPY\n");
len += snprintf(buf+len, PAGE_SIZE,
"num_requests:\t%u\n", test_fw_config->num_requests);
len += snprintf(buf+len, PAGE_SIZE,
"send_uevent:\t\t%s\n",
test_fw_config->send_uevent ?
"FW_ACTION_HOTPLUG" :
"FW_ACTION_NOHOTPLUG");
len += snprintf(buf+len, PAGE_SIZE,
"sync_direct:\t\t%s\n",
test_fw_config->sync_direct ? "true" : "false");
len += snprintf(buf+len, PAGE_SIZE,
"read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);
mutex_unlock(&test_fw_mutex);
return len;
}
static DEVICE_ATTR_RO(config);
static ssize_t config_name_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
mutex_lock(&test_fw_mutex);
kfree_const(test_fw_config->name);
ret = __kstrncpy(&test_fw_config->name, buf, count, GFP_KERNEL);
mutex_unlock(&test_fw_mutex);
return ret;
}
/*
* As per sysfs_kf_seq_show() the buf is max PAGE_SIZE.
*/
static ssize_t config_test_show_str(char *dst,
char *src)
{
int len;
mutex_lock(&test_fw_mutex);
len = snprintf(dst, PAGE_SIZE, "%s\n", src);
mutex_unlock(&test_fw_mutex);
return len;
}
static int test_dev_config_update_bool(const char *buf, size_t size,
bool *cfg)
{
int ret;
mutex_lock(&test_fw_mutex);
if (strtobool(buf, cfg) < 0)
ret = -EINVAL;
else
ret = size;
mutex_unlock(&test_fw_mutex);
return ret;
}
static ssize_t
test_dev_config_show_bool(char *buf,
bool config)
{
bool val;
mutex_lock(&test_fw_mutex);
val = config;
mutex_unlock(&test_fw_mutex);
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}
static ssize_t test_dev_config_show_int(char *buf, int cfg)
{
int val;
mutex_lock(&test_fw_mutex);
val = cfg;
mutex_unlock(&test_fw_mutex);
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}
static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
int ret;
long new;
ret = kstrtol(buf, 10, &new);
if (ret)
return ret;
if (new > U8_MAX)
return -EINVAL;
mutex_lock(&test_fw_mutex);
*(u8 *)cfg = new;
mutex_unlock(&test_fw_mutex);
/* Always return full write size even if we didn't consume all */
return size;
}
static ssize_t test_dev_config_show_u8(char *buf, u8 cfg)
{
u8 val;
mutex_lock(&test_fw_mutex);
val = cfg;
mutex_unlock(&test_fw_mutex);
return snprintf(buf, PAGE_SIZE, "%u\n", val);
}
static ssize_t config_name_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return config_test_show_str(buf, test_fw_config->name);
}
static DEVICE_ATTR_RW(config_name);
static ssize_t config_num_requests_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
mutex_lock(&test_fw_mutex);
if (test_fw_config->reqs) {
pr_err("Must call release_all_firmware prior to changing config\n");
rc = -EINVAL;
mutex_unlock(&test_fw_mutex);
goto out;
}
mutex_unlock(&test_fw_mutex);
rc = test_dev_config_update_u8(buf, count,
&test_fw_config->num_requests);
out:
return rc;
}
static ssize_t config_num_requests_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return test_dev_config_show_u8(buf, test_fw_config->num_requests);
}
static DEVICE_ATTR_RW(config_num_requests);
static ssize_t config_sync_direct_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc = test_dev_config_update_bool(buf, count,
&test_fw_config->sync_direct);
if (rc == count)
test_fw_config->req_firmware = test_fw_config->sync_direct ?
request_firmware_direct :
request_firmware;
return rc;
}
static ssize_t config_sync_direct_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return test_dev_config_show_bool(buf, test_fw_config->sync_direct);
}
static DEVICE_ATTR_RW(config_sync_direct);
static ssize_t config_send_uevent_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
return test_dev_config_update_bool(buf, count,
&test_fw_config->send_uevent);
}
static ssize_t config_send_uevent_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return test_dev_config_show_bool(buf, test_fw_config->send_uevent);
}
static DEVICE_ATTR_RW(config_send_uevent);
static ssize_t config_read_fw_idx_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
return test_dev_config_update_u8(buf, count,
&test_fw_config->read_fw_idx);
}
static ssize_t config_read_fw_idx_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return test_dev_config_show_u8(buf, test_fw_config->read_fw_idx);
}
static DEVICE_ATTR_RW(config_read_fw_idx);
static ssize_t trigger_request_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
char *name;
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOSPC;
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 DECLARE_COMPLETION(async_fw_done);
static void trigger_async_request_cb(const struct firmware *fw, void *context)
{
test_firmware = fw;
complete(&async_fw_done);
}
static ssize_t trigger_async_request_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
char *name;
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOSPC;
pr_info("loading '%s'\n", name);
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
test_firmware = NULL;
rc = request_firmware_nowait(THIS_MODULE, 1, name, dev, GFP_KERNEL,
NULL, trigger_async_request_cb);
if (rc) {
pr_info("async load of '%s' failed: %d\n", name, rc);
kfree(name);
goto out;
}
/* Free 'name' ASAP, to test for race conditions */
kfree(name);
wait_for_completion(&async_fw_done);
if (test_firmware) {
pr_info("loaded: %zu\n", test_firmware->size);
rc = count;
} else {
pr_err("failed to async load firmware\n");
rc = -ENODEV;
}
out:
mutex_unlock(&test_fw_mutex);
return rc;
}
static DEVICE_ATTR_WO(trigger_async_request);
static ssize_t trigger_custom_fallback_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
char *name;
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOSPC;
pr_info("loading '%s' using custom fallback mechanism\n", name);
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
test_firmware = NULL;
rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, name,
dev, GFP_KERNEL, NULL,
trigger_async_request_cb);
if (rc) {
pr_info("async load of '%s' failed: %d\n", name, rc);
kfree(name);
goto out;
}
/* Free 'name' ASAP, to test for race conditions */
kfree(name);
wait_for_completion(&async_fw_done);
if (test_firmware) {
pr_info("loaded: %zu\n", test_firmware->size);
rc = count;
} else {
pr_err("failed to async load firmware\n");
rc = -ENODEV;
}
out:
mutex_unlock(&test_fw_mutex);
return rc;
}
static DEVICE_ATTR_WO(trigger_custom_fallback);
static int test_fw_run_batch_request(void *data)
{
struct test_batched_req *req = data;
if (!req) {
test_fw_config->test_result = -EINVAL;
return -EINVAL;
}
req->rc = test_fw_config->req_firmware(&req->fw, req->name, req->dev);
if (req->rc) {
pr_info("#%u: batched sync load failed: %d\n",
req->idx, req->rc);
if (!test_fw_config->test_result)
test_fw_config->test_result = req->rc;
} else if (req->fw) {
req->sent = true;
pr_info("#%u: batched sync loaded %zu\n",
req->idx, req->fw->size);
}
complete(&req->completion);
req->task = NULL;
return 0;
}
/*
* We use a kthread as otherwise the kernel serializes all our sync requests
* and we would not be able to mimic batched requests on a sync call. Batched
* requests on a sync call can for instance happen on a device driver when
* multiple cards are used and firmware loading happens outside of probe.
*/
static ssize_t trigger_batched_requests_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct test_batched_req *req;
int rc;
u8 i;
mutex_lock(&test_fw_mutex);
test_fw_config->reqs =
vzalloc(array3_size(sizeof(struct test_batched_req),
test_fw_config->num_requests, 2));
if (!test_fw_config->reqs) {
rc = -ENOMEM;
goto out_unlock;
}
pr_info("batched sync firmware loading '%s' %u times\n",
test_fw_config->name, test_fw_config->num_requests);
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
req->fw = NULL;
req->idx = i;
req->name = test_fw_config->name;
req->dev = dev;
init_completion(&req->completion);
req->task = kthread_run(test_fw_run_batch_request, req,
"%s-%u", KBUILD_MODNAME, req->idx);
if (!req->task || IS_ERR(req->task)) {
pr_err("Setting up thread %u failed\n", req->idx);
req->task = NULL;
rc = -ENOMEM;
goto out_bail;
}
}
rc = count;
/*
* We require an explicit release to enable more time and delay of
* calling release_firmware() to improve our chances of forcing a
* batched request. If we instead called release_firmware() right away
* then we might miss on an opportunity of having a successful firmware
* request pass on the opportunity to be come a batched request.
*/
out_bail:
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
if (req->task || req->sent)
wait_for_completion(&req->completion);
}
/* Override any worker error if we had a general setup error */
if (rc < 0)
test_fw_config->test_result = rc;
out_unlock:
mutex_unlock(&test_fw_mutex);
return rc;
}
static DEVICE_ATTR_WO(trigger_batched_requests);
/*
* We wait for each callback to return with the lock held, no need to lock here
*/
static void trigger_batched_cb(const struct firmware *fw, void *context)
{
struct test_batched_req *req = context;
if (!req) {
test_fw_config->test_result = -EINVAL;
return;
}
/* forces *some* batched requests to queue up */
if (!req->idx)
ssleep(2);
req->fw = fw;
/*
* Unfortunately the firmware API gives us nothing other than a null FW
* if the firmware was not found on async requests. Best we can do is
* just assume -ENOENT. A better API would pass the actual return
* value to the callback.
*/
if (!fw && !test_fw_config->test_result)
test_fw_config->test_result = -ENOENT;
complete(&req->completion);
}
static
ssize_t trigger_batched_requests_async_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct test_batched_req *req;
bool send_uevent;
int rc;
u8 i;
mutex_lock(&test_fw_mutex);
test_fw_config->reqs =
vzalloc(array3_size(sizeof(struct test_batched_req),
test_fw_config->num_requests, 2));
if (!test_fw_config->reqs) {
rc = -ENOMEM;
goto out;
}
pr_info("batched loading '%s' custom fallback mechanism %u times\n",
test_fw_config->name, test_fw_config->num_requests);
send_uevent = test_fw_config->send_uevent ? FW_ACTION_HOTPLUG :
FW_ACTION_NOHOTPLUG;
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
req->name = test_fw_config->name;
req->fw = NULL;
req->idx = i;
init_completion(&req->completion);
rc = request_firmware_nowait(THIS_MODULE, send_uevent,
req->name,
dev, GFP_KERNEL, req,
trigger_batched_cb);
if (rc) {
pr_info("#%u: batched async load failed setup: %d\n",
i, rc);
req->rc = rc;
goto out_bail;
} else
req->sent = true;
}
rc = count;
out_bail:
/*
* We require an explicit release to enable more time and delay of
* calling release_firmware() to improve our chances of forcing a
* batched request. If we instead called release_firmware() right away
* then we might miss on an opportunity of having a successful firmware
* request pass on the opportunity to be come a batched request.
*/
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
if (req->sent)
wait_for_completion(&req->completion);
}
/* Override any worker error if we had a general setup error */
if (rc < 0)
test_fw_config->test_result = rc;
out:
mutex_unlock(&test_fw_mutex);
return rc;
}
static DEVICE_ATTR_WO(trigger_batched_requests_async);
static ssize_t test_result_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return test_dev_config_show_int(buf, test_fw_config->test_result);
}
static DEVICE_ATTR_RO(test_result);
static ssize_t release_all_firmware_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
test_release_all_firmware();
return count;
}
static DEVICE_ATTR_WO(release_all_firmware);
static ssize_t read_firmware_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct test_batched_req *req;
u8 idx;
ssize_t rc = 0;
mutex_lock(&test_fw_mutex);
idx = test_fw_config->read_fw_idx;
if (idx >= test_fw_config->num_requests) {
rc = -ERANGE;
goto out;
}
if (!test_fw_config->reqs) {
rc = -EINVAL;
goto out;
}
req = &test_fw_config->reqs[idx];
if (!req->fw) {
pr_err("#%u: failed to async load firmware\n", idx);
rc = -ENOENT;
goto out;
}
pr_info("#%u: loaded %zu\n", idx, req->fw->size);
if (req->fw->size > PAGE_SIZE) {
pr_err("Testing interface must use PAGE_SIZE firmware for now\n");
rc = -EINVAL;
goto out;
}
memcpy(buf, req->fw->data, req->fw->size);
rc = req->fw->size;
out:
mutex_unlock(&test_fw_mutex);
return rc;
}
static DEVICE_ATTR_RO(read_firmware);
#define TEST_FW_DEV_ATTR(name) &dev_attr_##name.attr
static struct attribute *test_dev_attrs[] = {
TEST_FW_DEV_ATTR(reset),
TEST_FW_DEV_ATTR(config),
TEST_FW_DEV_ATTR(config_name),
TEST_FW_DEV_ATTR(config_num_requests),
TEST_FW_DEV_ATTR(config_sync_direct),
TEST_FW_DEV_ATTR(config_send_uevent),
TEST_FW_DEV_ATTR(config_read_fw_idx),
/* These don't use the config at all - they could be ported! */
TEST_FW_DEV_ATTR(trigger_request),
TEST_FW_DEV_ATTR(trigger_async_request),
TEST_FW_DEV_ATTR(trigger_custom_fallback),
/* These use the config and can use the test_result */
TEST_FW_DEV_ATTR(trigger_batched_requests),
TEST_FW_DEV_ATTR(trigger_batched_requests_async),
TEST_FW_DEV_ATTR(release_all_firmware),
TEST_FW_DEV_ATTR(test_result),
TEST_FW_DEV_ATTR(read_firmware),
NULL,
};
ATTRIBUTE_GROUPS(test_dev);
static struct miscdevice test_fw_misc_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "test_firmware",
.fops = &test_fw_fops,
.groups = test_dev_groups,
};
static int __init test_firmware_init(void)
{
int rc;
test_fw_config = kzalloc(sizeof(struct test_config), GFP_KERNEL);
if (!test_fw_config)
return -ENOMEM;
rc = __test_firmware_config_init();
if (rc)
return rc;
rc = misc_register(&test_fw_misc_device);
if (rc) {
kfree(test_fw_config);
pr_err("could not register misc device: %d\n", rc);
return rc;
}
pr_warn("interface ready\n");
return 0;
}
module_init(test_firmware_init);
static void __exit test_firmware_exit(void)
{
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
misc_deregister(&test_fw_misc_device);
__test_firmware_config_free();
kfree(test_fw_config);
mutex_unlock(&test_fw_mutex);
pr_warn("removed interface\n");
}
module_exit(test_firmware_exit);
MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
MODULE_LICENSE("GPL");