/* * 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;Lines 1–500 of 1246. 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/* * 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;