// 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/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 += 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:\tEMTPY\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_HOTPLUG" : "FW_ACTION_NOHOTPLUG"); len += scnprintf(buf+len, PAGE_SIZE - len, "sync_direct:\t\t%s\n", test_fw_config->sync_direct ? "true" : "false"); len += scnprintf(buf+len, PAGE_SIZE - len, "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");