/* * kmod stress test driver * * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or at your option any * later version; or, when distributed separately from the Linux kernel or * when incorporated into other software packages, subject to the following * license: * * This program is free software; you can redistribute it and/or modify it * under the terms of copyleft-next (version 0.3.1 or later) as published * at http://copyleft-next.org/. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt /* * This driver provides an interface to trigger and test the kernel's * module loader through a series of configurations and a few triggers. * To test this driver use the following script as root: * * tools/testing/selftests/kmod/kmod.sh --help */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/kmod.h> #include <linux/printk.h> #include <linux/kthread.h> #include <linux/sched.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/device.h> #define TEST_START_NUM_THREADS 50 #define TEST_START_DRIVER "test_module" #define TEST_START_TEST_FS "xfs" #define TEST_START_TEST_CASE TEST_KMOD_DRIVER static bool force_init_test = false; module_param(force_init_test, bool_enable_only, 0644); MODULE_PARM_DESC(force_init_test, "Force kicking a test immediately after driver loads"); /* * For device allocation / registration */ static DEFINE_MUTEX(reg_dev_mutex); static LIST_HEAD(reg_test_devs); /* * num_test_devs actually represents the *next* ID of the next * device we will allow to create. */ static int num_test_devs; /** * enum kmod_test_case - linker table test case * * If you add a test case, please be sure to review if you need to se * @need_mod_put for your tests case. * * @TEST_KMOD_DRIVER: stress tests request_module() * @TEST_KMOD_FS_TYPE: stress tests get_fs_type() */ enum kmod_test_case { __TEST_KMOD_INVALID = 0, TEST_KMOD_DRIVER, TEST_KMOD_FS_TYPE, __TEST_KMOD_MAX, }; struct test_config { char *test_driver; char *test_fs; unsigned int num_threads; enum kmod_test_case test_case; int test_result; }; struct kmod_test_device; /** * kmod_test_device_info - thread info * * @ret_sync: return value if request_module() is used, sync request for * @TEST_KMOD_DRIVER * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE * @thread_idx: thread ID * @test_dev: test device test is being performed under * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module * (module_put(fs_sync->owner)) when done, otherwise you will not be able * to unload the respective modules and re-test. We use this to keep * accounting of when we need this and to help out in case we need to * error out and deal with module_put() on error. */ struct kmod_test_device_info { int ret_sync; struct file_system_type *fs_sync; struct task_struct *task_sync; unsigned int thread_idx; struct kmod_test_device *test_dev; bool need_mod_put; }; /** * kmod_test_device - test device to help test kmod * * @dev_idx: unique ID for test device * @config: configuration for the test * @misc_dev: we use a misc device under the hood * @dev: pointer to misc_dev's own struct device * @config_mutex: protects configuration of test * @trigger_mutex: the test trigger can only be fired once at a time * @thread_lock: protects @done count, and the @info per each thread * @done: number of threads which have completed or failed * @test_is_oom: when we run out of memory, use this to halt moving forward * @kthreads_done: completion used to signal when all work is done * @list: needed to be part of the reg_test_devs * @info: array of info for each thread */ struct kmod_test_device { int dev_idx; struct test_config config; struct miscdevice misc_dev; struct device *dev; struct mutex config_mutex; struct mutex trigger_mutex; struct mutex thread_mutex; unsigned int done; bool test_is_oom; struct completion kthreads_done; struct list_head list; struct kmod_test_device_info *info; }; static const char *test_case_str(enum kmod_test_case test_case) { switch (test_case) { case TEST_KMOD_DRIVER: return "TEST_KMOD_DRIVER"; case TEST_KMOD_FS_TYPE: return "TEST_KMOD_FS_TYPE"; default: return "invalid"; } } static struct miscdevice *dev_to_misc_dev(struct device *dev) { return dev_get_drvdata(dev); } static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) { return container_of(misc_dev, struct kmod_test_device, misc_dev); } static struct kmod_test_device *dev_to_test_dev(struct device *dev) { struct miscdevice *misc_dev; misc_dev = dev_to_misc_dev(dev); return misc_dev_to_test_dev(misc_dev); } /* Must run with thread_mutex held */ static void kmod_test_done_check(struct kmod_test_device *test_dev, unsigned int idx) { struct test_config *config = &test_dev->config; test_dev->done++; dev_dbg(test_dev->dev, "Done thread count: %u\n", test_dev->done); if (test_dev->done == config->num_threads) { dev_info(test_dev->dev, "Done: %u threads have all run now\n", test_dev->done); dev_info(test_dev->dev, "Last thread to run: %u\n", idx); complete(&test_dev->kthreads_done); } } static void test_kmod_put_module(struct kmod_test_device_info *info) { struct kmod_test_device *test_dev = info->test_dev; struct test_config *config = &test_dev->config; if (!info->need_mod_put) return; switch (config->test_case) { case TEST_KMOD_DRIVER: break; case TEST_KMOD_FS_TYPE: if (info->fs_sync && info->fs_sync->owner) module_put(info->fs_sync->owner); break; default: BUG(); } info->need_mod_put = true; } static int run_request(void *data) { struct kmod_test_device_info *info = data; struct kmod_test_device *test_dev = info->test_dev; struct test_config *config = &test_dev->config; switch (config->test_case) { case TEST_KMOD_DRIVER: info->ret_sync = request_module("%s", config->test_driver); break; case TEST_KMOD_FS_TYPE: info->fs_sync = get_fs_type(config->test_fs); info->need_mod_put = true; break; default: /* __trigger_config_run() already checked for test sanity */ BUG(); return -EINVAL; } dev_dbg(test_dev->dev, "Ran thread %u\n", info->thread_idx); test_kmod_put_module(info); mutex_lock(&test_dev->thread_mutex); info->task_sync = NULL; kmod_test_done_check(test_dev, info->thread_idx); mutex_unlock(&test_dev->thread_mutex); return 0; } static int tally_work_test(struct kmod_test_device_info *info) { struct kmod_test_device *test_dev = info->test_dev; struct test_config *config = &test_dev->config; int err_ret = 0; switch (config->test_case) { case TEST_KMOD_DRIVER: /* * Only capture errors, if one is found that's * enough, for now. */ if (info->ret_sync != 0) err_ret = info->ret_sync; dev_info(test_dev->dev, "Sync thread %d return status: %d\n", info->thread_idx, info->ret_sync); break; case TEST_KMOD_FS_TYPE: /* For now we make this simple */ if (!info->fs_sync) err_ret = -EINVAL; dev_info(test_dev->dev, "Sync thread %u fs: %s\n", info->thread_idx, info->fs_sync ? config->test_fs : "NULL"); break; default: BUG(); } return err_ret; } /* * XXX: add result option to display if all errors did not match. * For now we just keep any error code if one was found. * * If this ran it means *all* tasks were created fine and we * are now just collecting results. * * Only propagate errors, do not override with a subsequent success case. */ static void tally_up_work(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; struct kmod_test_device_info *info; unsigned int idx; int err_ret = 0; int ret = 0; mutex_lock(&test_dev->thread_mutex); dev_info(test_dev->dev, "Results:\n"); for (idx=0; idx < config->num_threads; idx++) { info = &test_dev->info[idx]; ret = tally_work_test(info); if (ret) err_ret = ret; } /* * Note: request_module() returns 256 for a module not found even * though modprobe itself returns 1. */ config->test_result = err_ret; mutex_unlock(&test_dev->thread_mutex); } static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx) { struct kmod_test_device_info *info = &test_dev->info[idx]; int fail_ret = -ENOMEM; mutex_lock(&test_dev->thread_mutex); info->thread_idx = idx; info->test_dev = test_dev; info->task_sync = kthread_run(run_request, info, "%s-%u", KBUILD_MODNAME, idx); if (!info->task_sync || IS_ERR(info->task_sync)) { test_dev->test_is_oom = true; dev_err(test_dev->dev, "Setting up thread %u failed\n", idx); info->task_sync = NULL; goto err_out; } else dev_dbg(test_dev->dev, "Kicked off thread %u\n", idx); mutex_unlock(&test_dev->thread_mutex); return 0; err_out: info->ret_sync = fail_ret; mutex_unlock(&test_dev->thread_mutex); return fail_ret; } static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; struct kmod_test_device_info *info; unsigned int i; dev_info(test_dev->dev, "Ending request_module() tests\n"); mutex_lock(&test_dev->thread_mutex); for (i=0; i < config->num_threads; i++) { info = &test_dev->info[i]; if (info->task_sync && !IS_ERR(info->task_sync)) { dev_info(test_dev->dev, "Stopping still-running thread %i\n", i); kthread_stop(info->task_sync); } /* * info->task_sync is well protected, it can only be * NULL or a pointer to a struct. If its NULL we either * never ran, or we did and we completed the work. Completed * tasks *always* put the module for us. This is a sanity * check -- just in case. */ if (info->task_sync && info->need_mod_put) test_kmod_put_module(info); } mutex_unlock(&test_dev->thread_mutex); } /* * Only wait *iff* we did not run into any errors during all of our thread * set up. If run into any issues we stop threads and just bail out with * an error to the trigger. This also means we don't need any tally work * for any threads which fail. */ static int try_requests(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; unsigned int idx; int ret; bool any_error = false; for (idx=0; idx < config->num_threads; idx++) { if (test_dev->test_is_oom) { any_error = true; break; } ret = try_one_request(test_dev, idx); if (ret) { any_error = true; break; } } if (!any_error) { test_dev->test_is_oom = false; dev_info(test_dev->dev, "No errors were found while initializing threads\n"); wait_for_completion(&test_dev->kthreads_done); tally_up_work(test_dev); } else { test_dev->test_is_oom = true; dev_info(test_dev->dev, "At least one thread failed to start, stop all work\n"); test_dev_kmod_stop_tests(test_dev); return -ENOMEM; } return 0; } static int run_test_driver(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; dev_info(test_dev->dev, "Test case: %s (%u)\n", test_case_str(config->test_case), config->test_case); dev_info(test_dev->dev, "Test driver to load: %s\n", config->test_driver); dev_info(test_dev->dev, "Number of threads to run: %u\n", config->num_threads); dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", config->num_threads - 1); return try_requests(test_dev); } static int run_test_fs_type(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; dev_info(test_dev->dev, "Test case: %s (%u)\n", test_case_str(config->test_case), config->test_case); dev_info(test_dev->dev, "Test filesystem to load: %s\n", config->test_fs); dev_info(test_dev->dev, "Number of threads to run: %u\n", config->num_threads); dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", config->num_threads - 1); return try_requests(test_dev); } static ssize_t config_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; int len = 0; mutex_lock(&test_dev->config_mutex); len += snprintf(buf, PAGE_SIZE, "Custom trigger configuration for: %s\n", dev_name(dev)); len += snprintf(buf+len, PAGE_SIZE - len, "Number of threads:\t%u\n", config->num_threads); len += snprintf(buf+len, PAGE_SIZE - len, "Test_case:\t%s (%u)\n", test_case_str(config->test_case), config->test_case); if (config->test_driver) len += snprintf(buf+len, PAGE_SIZE - len, "driver:\t%s\n", config->test_driver); else len += snprintf(buf+len, PAGE_SIZE - len, "driver:\tEMPTY\n"); if (config->test_fs) len += snprintf(buf+len, PAGE_SIZE - len, "fs:\t%s\n", config->test_fs); else len += snprintf(buf+len, PAGE_SIZE - len, "fs:\tEMPTY\n"); mutex_unlock(&test_dev->config_mutex); return len; } static DEVICE_ATTR_RO(config); /* * This ensures we don't allow kicking threads through if our configuration * is faulty. */ static int __trigger_config_run(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; test_dev->done = 0; switch (config->test_case) { case TEST_KMOD_DRIVER: return run_test_driver(test_dev); case TEST_KMOD_FS_TYPE: return run_test_fs_type(test_dev); default: dev_warn(test_dev->dev, "Invalid test case requested: %u\n", config->test_case); return -EINVAL; } } static int trigger_config_run(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; int ret; mutex_lock(&test_dev->trigger_mutex); mutex_lock(&test_dev->config_mutex); ret = __trigger_config_run(test_dev); if (ret < 0) goto out; dev_info(test_dev->dev, "General test result: %d\n", config->test_result); /* * We must return 0 after a trigger even unless something went * wrong with the setup of the test. If the test setup went fine * then userspace must just check the result of config->test_result. * One issue with relying on the return from a call in the kernel * is if the kernel returns a positive value using this trigger * will not return the value to userspace, it would be lost. * * By not relying on capturing the return value of tests we are using * through the trigger it also us to run tests with set -e and only * fail when something went wrong with the driver upon trigger * requests. */ ret = 0; out: mutex_unlock(&test_dev->config_mutex); mutex_unlock(&test_dev->trigger_mutex); return ret; } static ssize_t trigger_config_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); int ret; if (test_dev->test_is_oom) return -ENOMEM; /* For all intents and purposes we don't care what userspace * sent this trigger, we care only that we were triggered. * We treat the return value only for caputuring issues with * the test setup. At this point all the test variables should * have been allocated so typically this should never fail. */ ret = trigger_config_run(test_dev); if (unlikely(ret < 0)) goto out; /* * Note: any return > 0 will be treated as success * and the error value will not be available to userspace. * Do not rely on trying to send to userspace a test value * return value as positive return errors will be lost. */ if (WARN_ON(ret > 0)) return -EINVAL; ret = count; out: return ret; } static DEVICE_ATTR_WO(trigger_config); /* * 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 config_copy_test_driver_name(struct test_config *config, const char *name, size_t count) { return __kstrncpy(&config->test_driver, name, count, GFP_KERNEL); } static int config_copy_test_fs(struct test_config *config, const char *name, size_t count) { return __kstrncpy(&config->test_fs, name, count, GFP_KERNEL); } static void __kmod_config_free(struct test_config *config) { if (!config) return; kfree_const(config->test_driver); config->test_driver = NULL; kfree_const(config->test_fs); config->test_fs = NULL; } static void kmod_config_free(struct kmod_test_device *test_dev) { struct test_config *config; if (!test_dev) return; config = &test_dev->config; mutex_lock(&test_dev->config_mutex); __kmod_config_free(config); mutex_unlock(&test_dev->config_mutex); } static ssize_t config_test_driver_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; int copied; mutex_lock(&test_dev->config_mutex); kfree_const(config->test_driver); config->test_driver = NULL; copied = config_copy_test_driver_name(config, buf, count); mutex_unlock(&test_dev->config_mutex); return copied; } /* * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE. */ static ssize_t config_test_show_str(struct mutex *config_mutex, char *dst, char *src) { int len; mutex_lock(config_mutex); len = snprintf(dst, PAGE_SIZE, "%s\n", src); mutex_unlock(config_mutex); return len; } static ssize_t config_test_driver_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return config_test_show_str(&test_dev->config_mutex, buf, config->test_driver); } static DEVICE_ATTR_RW(config_test_driver); static ssize_t config_test_fs_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; int copied; mutex_lock(&test_dev->config_mutex); kfree_const(config->test_fs); config->test_fs = NULL; copied = config_copy_test_fs(config, buf, count); mutex_unlock(&test_dev->config_mutex); return copied; } static ssize_t config_test_fs_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return config_test_show_str(&test_dev->config_mutex, buf, config->test_fs); } static DEVICE_ATTR_RW(config_test_fs); static int trigger_config_run_type(struct kmod_test_device *test_dev, enum kmod_test_case test_case, const char *test_str) { int copied = 0; struct test_config *config = &test_dev->config; mutex_lock(&test_dev->config_mutex); switch (test_case) { case TEST_KMOD_DRIVER: kfree_const(config->test_driver); config->test_driver = NULL; copied = config_copy_test_driver_name(config, test_str, strlen(test_str)); break; case TEST_KMOD_FS_TYPE: kfree_const(config->test_fs); config->test_fs = NULL; copied = config_copy_test_fs(config, test_str, strlen(test_str)); break; default: mutex_unlock(&test_dev->config_mutex); return -EINVAL; } config->test_case = test_case; mutex_unlock(&test_dev->config_mutex); if (copied <= 0 || copied != strlen(test_str)) { test_dev->test_is_oom = true; return -ENOMEM; } test_dev->test_is_oom = false; return trigger_config_run(test_dev); } static void free_test_dev_info(struct kmod_test_device *test_dev) { vfree(test_dev->info); test_dev->info = NULL; } static int kmod_config_sync_info(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; free_test_dev_info(test_dev); test_dev->info = vzalloc(array_size(sizeof(struct kmod_test_device_info), config->num_threads)); if (!test_dev->info) return -ENOMEM; return 0; } /* * Old kernels may not have this, if you want to port this code to * test it on older kernels. */ #ifdef get_kmod_umh_limit static unsigned int kmod_init_test_thread_limit(void) { return get_kmod_umh_limit(); } #else static unsigned int kmod_init_test_thread_limit(void) { return TEST_START_NUM_THREADS; } #endif static int __kmod_config_init(struct kmod_test_device *test_dev) { struct test_config *config = &test_dev->config; int ret = -ENOMEM, copied; __kmod_config_free(config); copied = config_copy_test_driver_name(config, TEST_START_DRIVER, strlen(TEST_START_DRIVER)); if (copied != strlen(TEST_START_DRIVER)) goto err_out; copied = config_copy_test_fs(config, TEST_START_TEST_FS, strlen(TEST_START_TEST_FS)); if (copied != strlen(TEST_START_TEST_FS)) goto err_out; config->num_threads = kmod_init_test_thread_limit(); config->test_result = 0; config->test_case = TEST_START_TEST_CASE; ret = kmod_config_sync_info(test_dev); if (ret) goto err_out; test_dev->test_is_oom = false; return 0; err_out: test_dev->test_is_oom = true; WARN_ON(test_dev->test_is_oom); __kmod_config_free(config); return ret; } static ssize_t reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); int ret; mutex_lock(&test_dev->trigger_mutex); mutex_lock(&test_dev->config_mutex); ret = __kmod_config_init(test_dev); if (ret < 0) { ret = -ENOMEM; dev_err(dev, "could not alloc settings for config trigger: %d\n", ret); goto out; } dev_info(dev, "reset\n"); ret = count; out: mutex_unlock(&test_dev->config_mutex); mutex_unlock(&test_dev->trigger_mutex); return ret; } static DEVICE_ATTR_WO(reset); static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev, const char *buf, size_t size, unsigned int *config, int (*test_sync)(struct kmod_test_device *test_dev)) { int ret; unsigned int val; unsigned int old_val; ret = kstrtouint(buf, 10, &val); if (ret) return ret; mutex_lock(&test_dev->config_mutex); old_val = *config; *(unsigned int *)config = val; ret = test_sync(test_dev); if (ret) { *(unsigned int *)config = old_val; ret = test_sync(test_dev); WARN_ON(ret); mutex_unlock(&test_dev->config_mutex); return -EINVAL; } mutex_unlock(&test_dev->config_mutex); /* Always return full write size even if we didn't consume all */ return size; } static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev, const char *buf, size_t size, unsigned int *config, unsigned int min, unsigned int max) { unsigned int val; int ret; ret = kstrtouint(buf, 10, &val); if (ret) return ret; if (val < min || val > max) return -EINVAL; mutex_lock(&test_dev->config_mutex); *config = val; mutex_unlock(&test_dev->config_mutex); /* Always return full write size even if we didn't consume all */ return size; } static int test_dev_config_update_int(struct kmod_test_device *test_dev, const char *buf, size_t size, int *config) { int val; int ret; ret = kstrtoint(buf, 10, &val); if (ret) return ret; mutex_lock(&test_dev->config_mutex); *config = val; mutex_unlock(&test_dev->config_mutex); /* Always return full write size even if we didn't consume all */ return size; } static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev, char *buf, int config) { int val; mutex_lock(&test_dev->config_mutex); val = config; mutex_unlock(&test_dev->config_mutex); return snprintf(buf, PAGE_SIZE, "%d\n", val); } static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev, char *buf, unsigned int config) { unsigned int val; mutex_lock(&test_dev->config_mutex); val = config; mutex_unlock(&test_dev->config_mutex); return snprintf(buf, PAGE_SIZE, "%u\n", val); } static ssize_t test_result_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_update_int(test_dev, buf, count, &config->test_result); } static ssize_t config_num_threads_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_update_uint_sync(test_dev, buf, count, &config->num_threads, kmod_config_sync_info); } static ssize_t config_num_threads_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_show_int(test_dev, buf, config->num_threads); } static DEVICE_ATTR_RW(config_num_threads); static ssize_t config_test_case_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_update_uint_range(test_dev, buf, count, &config->test_case, __TEST_KMOD_INVALID + 1, __TEST_KMOD_MAX - 1); } static ssize_t config_test_case_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_show_uint(test_dev, buf, config->test_case); } static DEVICE_ATTR_RW(config_test_case); static ssize_t test_result_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kmod_test_device *test_dev = dev_to_test_dev(dev); struct test_config *config = &test_dev->config; return test_dev_config_show_int(test_dev, buf, config->test_result); } static DEVICE_ATTR_RW(test_result); #define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr static struct attribute *test_dev_attrs[] = { TEST_KMOD_DEV_ATTR(trigger_config), TEST_KMOD_DEV_ATTR(config), TEST_KMOD_DEV_ATTR(reset), TEST_KMOD_DEV_ATTR(config_test_driver), TEST_KMOD_DEV_ATTR(config_test_fs), TEST_KMOD_DEV_ATTR(config_num_threads), TEST_KMOD_DEV_ATTR(config_test_case), TEST_KMOD_DEV_ATTR(test_result), NULL, }; ATTRIBUTE_GROUPS(test_dev); static int kmod_config_init(struct kmod_test_device *test_dev) { int ret; mutex_lock(&test_dev->config_mutex); ret = __kmod_config_init(test_dev); mutex_unlock(&test_dev->config_mutex); return ret; } static struct kmod_test_device *alloc_test_dev_kmod(int idx) { int ret; struct kmod_test_device *test_dev; struct miscdevice *misc_dev; test_dev = vzalloc(sizeof(struct kmod_test_device)); if (!test_dev) goto err_out; mutex_init(&test_dev->config_mutex); mutex_init(&test_dev->trigger_mutex); mutex_init(&test_dev->thread_mutex); init_completion(&test_dev->kthreads_done); ret = kmod_config_init(test_dev); if (ret < 0) { pr_err("Cannot alloc kmod_config_init()\n"); goto err_out_free; } test_dev->dev_idx = idx; misc_dev = &test_dev->misc_dev; misc_dev->minor = MISC_DYNAMIC_MINOR; misc_dev->name = kasprintf(GFP_KERNEL, "test_kmod%d", idx); if (!misc_dev->name) { pr_err("Cannot alloc misc_dev->name\n"); goto err_out_free_config; } misc_dev->groups = test_dev_groups; return test_dev; err_out_free_config: free_test_dev_info(test_dev); kmod_config_free(test_dev); err_out_free: vfree(test_dev); test_dev = NULL; err_out: return NULL; } static void free_test_dev_kmod(struct kmod_test_device *test_dev) { if (test_dev) { kfree_const(test_dev->misc_dev.name); test_dev->misc_dev.name = NULL; free_test_dev_info(test_dev); kmod_config_free(test_dev); vfree(test_dev); test_dev = NULL; } } static struct kmod_test_device *register_test_dev_kmod(void) { struct kmod_test_device *test_dev = NULL; int ret; mutex_lock(®_dev_mutex); /* int should suffice for number of devices, test for wrap */ if (num_test_devs + 1 == INT_MAX) { pr_err("reached limit of number of test devices\n"); goto out; } test_dev = alloc_test_dev_kmod(num_test_devs); if (!test_dev) goto out; ret = misc_register(&test_dev->misc_dev); if (ret) { pr_err("could not register misc device: %d\n", ret); free_test_dev_kmod(test_dev); goto out; } test_dev->dev = test_dev->misc_dev.this_device; list_add_tail(&test_dev->list, ®_test_devs); dev_info(test_dev->dev, "interface ready\n"); num_test_devs++; out: mutex_unlock(®_dev_mutex); return test_dev; } static int __init test_kmod_init(void) { struct kmod_test_device *test_dev; int ret; test_dev = register_test_dev_kmod(); if (!test_dev) { pr_err("Cannot add first test kmod device\n"); return -ENODEV; } /* * With some work we might be able to gracefully enable * testing with this driver built-in, for now this seems * rather risky. For those willing to try have at it, * and enable the below. Good luck! If that works, try * lowering the init level for more fun. */ if (force_init_test) { ret = trigger_config_run_type(test_dev, TEST_KMOD_DRIVER, "tun"); if (WARN_ON(ret)) return ret; ret = trigger_config_run_type(test_dev, TEST_KMOD_FS_TYPE, "btrfs"); if (WARN_ON(ret)) return ret; } return 0; } late_initcall(test_kmod_init); static void unregister_test_dev_kmod(struct kmod_test_device *test_dev) { mutex_lock(&test_dev->trigger_mutex); mutex_lock(&test_dev->config_mutex); test_dev_kmod_stop_tests(test_dev); dev_info(test_dev->dev, "removing interface\n"); misc_deregister(&test_dev->misc_dev); mutex_unlock(&test_dev->config_mutex); mutex_unlock(&test_dev->trigger_mutex); free_test_dev_kmod(test_dev); } static void __exit test_kmod_exit(void) { struct kmod_test_device *test_dev, *tmp; mutex_lock(®_dev_mutex); list_for_each_entry_safe(test_dev, tmp, ®_test_devs, list) { list_del(&test_dev->list); unregister_test_dev_kmod(test_dev); } mutex_unlock(®_dev_mutex); } module_exit(test_kmod_exit); MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>"); MODULE_LICENSE("GPL");