path: root/lib/test_firmware.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/sizes.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>
#include <linux/efi_embedded_fw.h>

MODULE_IMPORT_NS(TEST_FIRMWARE);

#define TEST_FIRMWARE_NAME	"test-firmware.bin"
#define TEST_FIRMWARE_NUM_REQS	4
#define TEST_FIRMWARE_BUF_SIZE	SZ_1K
#define TEST_UPLOAD_MAX_SIZE	SZ_2K
#define TEST_UPLOAD_BLK_SIZE	37	/* Avoid powers of two in testing */

static DEFINE_MUTEX(test_fw_mutex);
static const struct firmware *test_firmware;
static LIST_HEAD(test_upload_list);

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
 * @into_buf: when the into_buf is used if this is true
 *	request_firmware_into_buf() will be used instead.
 * @buf_size: size of buf to allocate when into_buf is true
 * @file_offset: file offset to request when calling request_firmware_into_buf
 * @partial: partial read opt when calling request_firmware_into_buf
 * @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.
 * @upload_name: firmware name to be used with upload_read sysfs node
 * @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 into_buf;
	size_t buf_size;
	size_t file_offset;
	bool partial;
	bool sync_direct;
	bool send_uevent;
	u8 num_requests;
	u8 read_fw_idx;
	char *upload_name;

	/*
	 * 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);
};

struct upload_inject_err {
	const char *prog;
	enum fw_upload_err err_code;
};

struct test_firmware_upload {
	char *name;
	struct list_head node;
	char *buf;
	size_t size;
	bool cancel_request;
	struct upload_inject_err inject;
	struct fw_upload *fwl;
};

static struct test_config *test_fw_config;

static struct test_firmware_upload *upload_lookup_name(const char *name)
{
	struct test_firmware_upload *tst;

	list_for_each_entry(tst, &test_upload_list, node)
		if (strncmp(name, tst->name, strlen(tst->name)) == 0)
			return tst;

	return NULL;
}

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->into_buf = false;
	test_fw_config->buf_size = TEST_FIRMWARE_BUF_SIZE;
	test_fw_config->file_offset = 0;
	test_fw_config->partial = false;
	test_fw_config->sync_direct = false;
	test_fw_config->req_firmware = request_firmware;
	test_fw_config->test_result = 0;
	test_fw_config->reqs = NULL;
	test_fw_config->upload_name = 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 += scnprintf(buf, PAGE_SIZE - len,
			"Custom trigger configuration for: %s\n",
			dev_name(dev));

	if (test_fw_config->name)
		len += scnprintf(buf + len, PAGE_SIZE - len,
				"name:\t%s\n",
				test_fw_config->name);
	else
		len += scnprintf(buf + len, PAGE_SIZE - len,
				"name:\tEMPTY\n");

	len += scnprintf(buf + len, PAGE_SIZE - len,
			"num_requests:\t%u\n", test_fw_config->num_requests);

	len += scnprintf(buf + len, PAGE_SIZE - len,
			"send_uevent:\t\t%s\n",
			test_fw_config->send_uevent ?
			"FW_ACTION_UEVENT" :
			"FW_ACTI