// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1
/*
* kmod stress test driver
*
* Copyright (C) 2017 Luis R. Rodriguez <[email protected]>
*/
#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
* @TEST_KMOD_DRIVER: stress tests request_module()
* @TEST_KMOD_FS_TYPE: stress tests get_fs_type()
*
* If you add a test case, please be sure to review if you need to set
* @need_mod_put for your tests case.
*/
enum kmod_test_case {
/* private: */
__TEST_KMOD_INVALID = 0,
/* public: */
TEST_KMOD_DRIVER,
TEST_KMOD_FS_TYPE,
/* private: */
__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;
/**
* struct 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
* @task_sync: kthread's task_struct or %NULL if not running
* @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;
};
/**
* struct 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_mutex: 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);
test_dev = NULL;
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 <[email protected]>");
MODULE_DESCRIPTION("kmod stress test driver");
MODULE_LICENSE("GPL");
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