v4.19.13 snapshot.
diff --git a/lib/test_kmod.c b/lib/test_kmod.c
new file mode 100644
index 0000000..d82d022
--- /dev/null
+++ b/lib/test_kmod.c
@@ -0,0 +1,1238 @@
+/*
+ * 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 && 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 sucess 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 possitive 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 possitive 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_driver = 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_driver = 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 long new;
+ unsigned int old_val;
+
+ ret = kstrtoul(buf, 10, &new);
+ if (ret)
+ return ret;
+
+ if (new > UINT_MAX)
+ return -EINVAL;
+
+ mutex_lock(&test_dev->config_mutex);
+
+ old_val = *config;
+ *(unsigned int *)config = new;
+
+ 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)
+{
+ int ret;
+ unsigned long new;
+
+ ret = kstrtoul(buf, 10, &new);
+ if (ret)
+ return ret;
+
+ if (new < min || new > max)
+ return -EINVAL;
+
+ mutex_lock(&test_dev->config_mutex);
+ *config = new;
+ 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 ret;
+ long new;
+
+ ret = kstrtol(buf, 10, &new);
+ if (ret)
+ return ret;
+
+ if (new < INT_MIN || new > INT_MAX)
+ return -EINVAL;
+
+ mutex_lock(&test_dev->config_mutex);
+ *config = new;
+ 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");