On Thu, Dec 8, 2016 at 10:47 AM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote: > This adds a new stress test driver for kmod: the kernel module loader. > The new stress test driver, test_kmod, is only enabled as a module right > now. It should be possible to load this as built-in and load tests early > (refer to the force_init_test module parameter), however since a lot of > test can get a system out of memory fast we leave this disabled for now. > > Using a system with 1024 MiB of RAM can *easily* get your kernel > OOM fast with this test driver. > > The test_kmod driver exposes API knobs for us to fine tune simple > request_module() and get_fs_type() calls. Since these API calls > only allow each one parameter a test driver for these is rather > simple. Other factors that can help out test driver though are > the number of calls we issue and knowing current limitations of > each. This exposes configuration as much as possible through > userspace to be able to build tests directly from userspace. > > Since it allows multiple misc devices its will eventually (once we > add a knob to let us create new devices at will) also be possible to > perform more tests in parallel, provided you have enough memory. > > We only enable tests we know work as of right now. > > Demo screenshots: > > # tools/testing/selftests/kmod/kmod.sh > kmod_test_0001_driver: OK! - loading kmod test > kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND > kmod_test_0001_fs: OK! - loading kmod test > kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL > kmod_test_0002_driver: OK! - loading kmod test > kmod_test_0002_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND > kmod_test_0002_fs: OK! - loading kmod test > kmod_test_0002_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL > kmod_test_0003: OK! - loading kmod test > kmod_test_0003: OK! - Return value: 0 (SUCCESS), expected SUCCESS > kmod_test_0004: OK! - loading kmod test > kmod_test_0004: OK! - Return value: 0 (SUCCESS), expected SUCCESS > kmod_test_0005: OK! - loading kmod test > kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS > kmod_test_0006: OK! - loading kmod test > kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS > kmod_test_0005: OK! - loading kmod test > kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS > kmod_test_0006: OK! - loading kmod test > kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS > Test completed > > You can also request for specific tests: > > # tools/testing/selftests/kmod/kmod.sh -t 0001 > kmod_test_0001_driver: OK! - loading kmod test > kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND > kmod_test_0001_fs: OK! - loading kmod test > kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL > Test completed > > Lastly, the current available number of tests: > > # tools/testing/selftests/kmod/kmod.sh --help > Usage: tools/testing/selftests/kmod/kmod.sh [ -t <4-number-digit> ] > Valid tests: 0001-0009 > > 0001 - Simple test - 1 thread for empty string > 0002 - Simple test - 1 thread for modules/filesystems that do not exist > 0003 - Simple test - 1 thread for get_fs_type() only > 0004 - Simple test - 2 threads for get_fs_type() only > 0005 - multithreaded tests with default setup - request_module() only > 0006 - multithreaded tests with default setup - get_fs_type() only > 0007 - multithreaded tests with default setup test request_module() and get_fs_type() > 0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module() > 0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type() > > The following test cases currently fail, as such they are not currently > enabled by default: > > # tools/testing/selftests/kmod/kmod.sh -t 0007 > # tools/testing/selftests/kmod/kmod.sh -t 0008 > # tools/testing/selftests/kmod/kmod.sh -t 0009 > # tools/testing/selftests/kmod/kmod.sh -t 0010 > # tools/testing/selftests/kmod/kmod.sh -t 0011 > > To be sure to run them as intended please unload both of the modules: > > o test_module > o xfs > > And ensure they are not loaded on your system prior to testing them. > If you use these paritions for your rootfs you can change the default > test driver used for get_fs_type() by exporting it into your > environment. For example of other test defaults you can override > refer to kmod.sh allow_user_defaults(). > > Behind the scenes this is how we fine tune at a test case prior to > hitting a trigger to run it: > > cat /sys/devices/virtual/misc/test_kmod0/config > echo -n "2" > /sys/devices/virtual/misc/test_kmod0/config_test_case > echo -n "ext4" > /sys/devices/virtual/misc/test_kmod0/config_test_fs > echo -n "80" > /sys/devices/virtual/misc/test_kmod0/config_num_threads > cat /sys/devices/virtual/misc/test_kmod0/config > echo -n "1" > /sys/devices/virtual/misc/test_kmod0/config_num_threads > > Finally to trigger: > > echo -n "1" > /sys/devices/virtual/misc/test_kmod0/trigger_config > > The kmod.sh script uses the above constructs to build differnt test cases. Typo: different > A bit of interpretation of the current failures follows, first two > premises: > > a) When request_module() is used userspace figures out an optimized version of > module order for us. Once it finds the modules it needs, as per depmod > symbol dep map, it will finit_module() the respective modules which > are needed for the original request_module() request. > > b) We have an optimization in place whereby if a kernel uses > request_module() on a module already loaded we never bother > userspace as the module already is loaded. This is all handled by > kernel/kmod.c. > > A few things to consider to help identify root causes of issues: > > 0) kmod 19 has a broken heuristic for modules being assumed to be > built-in to your kernel and will return 0 even though request_module() > failed. Upgrade to a newer version of kmod. > > 1) A get_fs_type() call for "xfs" will request_module() for > "fs-xfs", not for "xfs". The optimization in kernel described in b) > fails to catch if we have a lot of consecutive get_fs_type() calls. > The reason is the optimization in place does not look for aliases. This > means two consecutive get_fs_type() calls will bump kmod_concurrent, whereas > request_module() will not. > > This one explanation why test case 0009 fails at least once for > get_fs_type(). > > 2) If a module fails to load --- for whatever reason (kmod_concurrent > limit reached, file not yet present due to rootfs switch, out of memory) > we have a period of time during which module request for the same name > either with request_module() or get_fs_type() will *also* fail to load > even if the file for the module is ready. > > This explains why *multiple* NULLs are possible on test 0009. > > 3) finit_module() consumes quite a bit of memory. Is this due to reading the module into kernel memory or something else? > 4) Filesystems typically also have more dependent modules than other > modules, its important to note though that even though a get_fs_type() call > does not incur additional kmod_concurrent bumps, since userspace > loads dependencies it finds it needs via finit_module_fd(), it *will* > take much more memory to load a module with a lot of dependencies. > > Because of 3) and 4) we will easily run into out of memory failures > with certain tests. For instance test 0006 fails on qemu with 1024 MiB > of RAM. It panics a box after reaping all userspace processes and still > not having enough memory to reap. Are the buffers not released until after all the dependent modules are loaded? I thought it would load one by one? > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx> This is a great selftest, thanks for working on it! Notes below... > --- > lib/Kconfig.debug | 25 + > lib/Makefile | 1 + > lib/test_kmod.c | 1248 +++++++++++++++++++++++++++++++++ > tools/testing/selftests/kmod/Makefile | 11 + > tools/testing/selftests/kmod/config | 7 + > tools/testing/selftests/kmod/kmod.sh | 449 ++++++++++++ > 6 files changed, 1741 insertions(+) > create mode 100644 lib/test_kmod.c > create mode 100644 tools/testing/selftests/kmod/Makefile > create mode 100644 tools/testing/selftests/kmod/config > create mode 100755 tools/testing/selftests/kmod/kmod.sh > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 7446097f72bd..6cad548e0682 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1994,6 +1994,31 @@ config BUG_ON_DATA_CORRUPTION > > If unsure, say N. > > +config TEST_KMOD > + tristate "kmod stress tester" > + default n > + depends on m > + select TEST_LKM > + select XFS_FS > + select TUN > + select BTRFS_FS Since the desired FS can be changed at runtime, maybe these selects aren't needed? > + help > + Test the kernel's module loading mechanism: kmod. kmod implements > + support to load modules using the Linux kernel's usermode helper. > + This test provides a series of tests against kmod. > + > + Although technically you can either build test_kmod as a module or > + into the kernel we disallow building it into the kernel since > + it stress tests request_module() and this will very likely cause > + some issues by taking over precious threads available from other > + module load requests, ultimately this could be fatal. > + > + To run tests run: > + > + tools/testing/selftests/kmod/kmod.sh --help > + > + If unsure, say N. > + > source "samples/Kconfig" > > source "lib/Kconfig.kgdb" > diff --git a/lib/Makefile b/lib/Makefile > index d15e235f72ea..3c5a14821e16 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -55,6 +55,7 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o > obj-$(CONFIG_TEST_PRINTF) += test_printf.o > obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o > obj-$(CONFIG_TEST_UUID) += test_uuid.o > +obj-$(CONFIG_TEST_KMOD) += test_kmod.o > > ifeq ($(CONFIG_DEBUG_KOBJECT),y) > CFLAGS_kobject.o += -DDEBUG > diff --git a/lib/test_kmod.c b/lib/test_kmod.c > new file mode 100644 > index 000000000000..63fded83b9b6 > --- /dev/null > +++ b/lib/test_kmod.c > @@ -0,0 +1,1248 @@ > +/* > + * kmod stress test driver > + * > + * Copyright (C) 2016 Luis R. Rodriguez <mcgrof@xxxxxxxxxx> > + * > + * 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 immediatley after driver loads"); Typo: immediately > + > +/* > + * 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 += sprintf(buf, "Custom trigger configuration for: %s\n", > + dev_name(dev)); > + > + len += sprintf(buf+len, "Number of threads:\t%u\n", > + config->num_threads); > + > + len += sprintf(buf+len, "Test_case:\t%s (%u)\n", > + test_case_str(config->test_case), > + config->test_case); > + > + if (config->test_driver) > + len += sprintf(buf+len, "driver:\t%s\n", > + config->test_driver); > + else > + len += sprintf(buf+len, "driver:\tEMTPY\n"); > + > + if (config->test_fs) > + len += sprintf(buf+len, "fs:\t%s\n", > + config->test_fs); > + else > + len += sprintf(buf+len, "fs:\tEMTPY\n"); These should all use snprintf... > + > + > + 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; > +} > + > +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; > + > + mutex_lock(&test_dev->config_mutex); > + strcpy(buf, config->test_driver); > + strcat(buf, "\n"); IIUC, the show/store API uses a max size of PAGE_SIZE. If that's correct, it's possible that this show routine could write past the end of buf, due to the end newline, etc. Best to use snprintf like you do below for the other shows. > + mutex_unlock(&test_dev->config_mutex); > + > + return strlen(buf) + 1; > +} > +static DEVICE_ATTR(config_test_driver, 0644, config_test_driver_show, > + config_test_driver_store); > + > +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; > + > + mutex_lock(&test_dev->config_mutex); > + strcpy(buf, config->test_fs); > + strcat(buf, "\n"); > + mutex_unlock(&test_dev->config_mutex); Same here... (which, btw, could likely use to be a helper function, the show and store functions here are identical except for test_driver vs test_fs). > + > + return strlen(buf) + 1; > +} > +static DEVICE_ATTR(config_test_fs, 0644, config_test_fs_show, > + config_test_fs_store); > + > +static int trigger_config_run_driver(struct kmod_test_device *test_dev, > + const char *test_driver) > +{ > + int copied; > + struct test_config *config = &test_dev->config; > + > + mutex_lock(&test_dev->config_mutex); > + > + config->test_case = TEST_KMOD_DRIVER; > + > + kfree_const(config->test_driver); > + config->test_driver = NULL; > + > + copied = config_copy_test_driver_name(config, test_driver, > + strlen(test_driver)); > + mutex_unlock(&test_dev->config_mutex); > + > + if (copied != strlen(test_driver)) { Can't these copied tests just check < 0? (i.e. avoid the repeated strlen which can be fragile.) > + test_dev->test_is_oom = true; > + return -EINVAL; > + } > + > + test_dev->test_is_oom = false; > + > + return trigger_config_run(test_dev); > +} > + > +static int trigger_config_run_fs(struct kmod_test_device *test_dev, > + const char *fs_type) > +{ > + int copied; > + struct test_config *config = &test_dev->config; > + > + mutex_lock(&test_dev->config_mutex); > + config->test_case = TEST_KMOD_FS_TYPE; > + > + kfree_const(config->test_fs); > + config->test_driver = NULL; > + > + copied = config_copy_test_fs(config, fs_type, strlen(fs_type)); > + mutex_unlock(&test_dev->config_mutex); > + > + if (copied != strlen(fs_type)) { > + test_dev->test_is_oom = true; > + return -EINVAL; > + } > + > + test_dev->test_is_oom = false; > + > + return trigger_config_run(test_dev); > +} These two functions are almost identical too. Only test_case and the copy function change... > + > +static void free_test_dev_info(struct kmod_test_device *test_dev) > +{ > + if (test_dev->info) { > + vfree(test_dev->info); > + test_dev->info = NULL; > + } > +} vfree() already checks for NULL, you can drop the if. > + > +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(config->num_threads * > + sizeof(struct kmod_test_device_info)); > + if (!test_dev->info) { > + dev_err(test_dev->dev, "Cannot alloc test_dev info\n"); > + 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; > + char *end; > + long new = simple_strtol(buf, &end, 0); > + unsigned int old_val; > + if (end == buf || 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) > +{ > + char *end; > + long new = simple_strtol(buf, &end, 0); > + if (end == buf || new < min || new > max || new > UINT_MAX) > + return -EINVAL; > + > + mutex_lock(&test_dev->config_mutex); > + *(unsigned int *)config = new; config is already an unsigned int *, why cast? > + 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) > +{ > + char *end; > + long new = simple_strtol(buf, &end, 0); > + if (end == buf || new > INT_MAX || new < INT_MIN) > + return -EINVAL; > + mutex_lock(&test_dev->config_mutex); > + *(int *)config = new; config is already an int *, why cast? > + 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(config_num_threads, 0644, config_num_threads_show, > + config_num_threads_store); > + > +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(config_test_case, 0644, config_test_case_show, > + config_test_case_store); > + > +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(test_result, 0644, test_result_show, test_result_store); > + > +#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; > +} > + > +/* > + * XXX: this could perhaps be made generic already too, but a hunt > + * for actual users would be needed first. It could be generic > + * if other test drivers end up using a similar mechanism. > + */ > +const char *test_dev_get_name(const char *base, int idx, gfp_t gfp) > +{ > + const char *name_const; > + char *name; > + > + if (!base) > + return NULL; > + if (strlen(base) > 30) > + return NULL; why? > + name = kzalloc(1024, gfp); > + if (!name) > + return NULL; > + > + strncat(name, base, strlen(base)); > + sprintf(name+(strlen(base)), "%d", idx); > + name_const = kstrdup_const(name, gfp); > + > + kfree(name); > + > + return name_const; > +} What is going on here? Why not just: return kasprintf(gfp, "%s%d", base, idx); For all of that code? And kstrdup_const is pointless here since it'll always just do the dup (as the kmalloc source isn't in rodata). > + > +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) { > + pr_err("Cannot alloc test_dev\n"); > + 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 = test_dev_get_name("test_kmod", test_dev->dev_idx, > + GFP_KERNEL); > + 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_unlock(®_dev_mutex); > + > + /* int should suffice for number of devices, test for wrap */ > + if (unlikely(num_test_devs + 1) < 0) { > + 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_driver(test_dev, "tun"); > + if (WARN_ON(ret)) > + return ret; > + ret = trigger_config_run_fs(test_dev, "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@xxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > diff --git a/tools/testing/selftests/kmod/Makefile b/tools/testing/selftests/kmod/Makefile > new file mode 100644 > index 000000000000..fa2ccc5fb3de > --- /dev/null > +++ b/tools/testing/selftests/kmod/Makefile > @@ -0,0 +1,11 @@ > +# Makefile for kmod loading selftests > + > +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests" > +all: > + > +TEST_PROGS := kmod.sh > + > +include ../lib.mk > + > +# Nothing to clean up. > +clean: > diff --git a/tools/testing/selftests/kmod/config b/tools/testing/selftests/kmod/config > new file mode 100644 > index 000000000000..259f4fd6b5e2 > --- /dev/null > +++ b/tools/testing/selftests/kmod/config > @@ -0,0 +1,7 @@ > +CONFIG_TEST_KMOD=m > +CONFIG_TEST_LKM=m > +CONFIG_XFS_FS=m > + > +# For the module parameter force_init_test is used > +CONFIG_TUN=m > +CONFIG_BTRFS_FS=m > diff --git a/tools/testing/selftests/kmod/kmod.sh b/tools/testing/selftests/kmod/kmod.sh > new file mode 100755 > index 000000000000..9ea1864d8bae > --- /dev/null > +++ b/tools/testing/selftests/kmod/kmod.sh > @@ -0,0 +1,449 @@ > +#!/bin/bash > +# > +# Copyright (C) 2016 Luis R. Rodriguez <mcgrof@xxxxxxxxxx> > +# > +# 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/. > + > +# This is a stress test script for kmod, the kernel module loader. It uses > +# test_kmod which exposes a series of knobs for the API for us so we can > +# tweak each test in userspace rather than in kernelspace. > +# > +# The way kmod works is it uses the kernel's usermode helper API to eventually > +# call /sbin/modprobe. It has a limit of the number of concurrent calls > +# possible. The kernel interface to load modules is request_module(), however > +# mount uses get_fs_type(). Both behave slightly differently, but the > +# differences are important enough to test each call separately. For this > +# reason test_kmod starts by providing tests for both calls. > +# > +# The test driver test_kmod assumes a series of defaults which you can > +# override by exporting to your environment prior running this script. > +# For instance this script assumes you do not have xfs loaded upon boot. > +# If this is false, export DEFAULT_KMOD_FS="ext4" prior to running this > +# script if the filesyste module you don't have loaded upon bootup > +# is ext4 instead. Refer to allow_user_defaults() for a list of user > +# override variables possible. > +# > +# You'll want at least 4096 GiB of RAM to expect to run these tests 4TiB of RAM? I assume this was meant to be 4 GiB not 4096? > +# without running out of memory on them. For other requirements refer > +# to test_reqs() > + > +set -e > + > +TEST_DRIVER="test_kmod" > + > +function allow_user_defaults() > +{ > + if [ -z $DEFAULT_KMOD_DRIVER ]; then > + DEFAULT_KMOD_DRIVER="test_module" > + fi > + > + if [ -z $DEFAULT_KMOD_FS ]; then > + DEFAULT_KMOD_FS="xfs" > + fi > + > + if [ -z $PROC_DIR ]; then > + PROC_DIR="/proc/sys/kernel/" > + fi > + > + if [ -z $MODPROBE_LIMIT ]; then > + MODPROBE_LIMIT=50 > + fi > + > + if [ -z $DIR ]; then > + DIR="/sys/devices/virtual/misc/${TEST_DRIVER}0/" > + fi > + > + MODPROBE_LIMIT_FILE="${PROC_DIR}/kmod-limit" > +} > + > +test_reqs() > +{ > + if ! which modprobe 2> /dev/null > /dev/null; then > + echo "$0: You need modprobe installed" While not a huge deal, I prefer that error messages end up on stderr, so adding >&2 to all the failure echos (or providing an err function) would be nice. (This happens in later places...) > + exit 1 > + fi > + > + if ! which kmod 2> /dev/null > /dev/null; then > + echo "$0: You need kmod installed" > + exit 1 > + fi > + > + # kmod 19 has a bad bug where it returns 0 when modprobe > + # gets called *even* if the module was not loaded due to > + # some bad heuristics. For details see: > + # > + # A work around is possible in-kernel but its rather > + # complex. > + KMOD_VERSION=$(kmod --version | awk '{print $3}') > + if [[ $KMOD_VERSION -le 19 ]]; then > + echo "$0: You need at least kmod 20" > + echo "kmod <= 19 is buggy, for details see:" > + echo "http://git.kernel.org/cgit/utils/kernel/kmod/kmod.git/commit/libkmod/libkmod-module.c?id=fd44a98ae2eb5eb32161088954ab21e58e19dfc4"; > + exit 1 > + fi > +} > + > +function load_req_mod() > +{ > + if [ ! -d $DIR ]; then > + # Alanis: "Oh isn't it ironic?" > + modprobe $TEST_DRIVER > + if [ ! -d $DIR ]; then > + echo "$0: $DIR not present" > + echo "You must have the following enabled in your kernel:" > + cat $PWD/config I like this (minimum config in the test directory). Are other tests doing this too? > + exit 1 > + fi > + fi > +} > + > +test_finish() > +{ > + echo "Test completed" > +} > + > +errno_name_to_val() > +{ > + case "$1" in > + # kmod calls modprobe and upon of a module not found > + # modprobe returns just 1... However in the kernel we > + # *sometimes* see 256... > + MODULE_NOT_FOUND) > + echo 256;; > + SUCCESS) > + echo 0;; > + -EPERM) > + echo -1;; > + -ENOENT) > + echo -2;; > + -EINVAL) > + echo -22;; > + -ERR_ANY) > + echo -123456;; > + *) > + echo invalid;; > + esac > +} > + > +errno_val_to_name() > + case "$1" in > + 256) > + echo MODULE_NOT_FOUND;; > + 0) > + echo SUCCESS;; > + -1) > + echo -EPERM;; > + -2) > + echo -ENOENT;; > + -22) > + echo -EINVAL;; > + -123456) > + echo -ERR_ANY;; > + *) > + echo invalid;; > + esac > + > +config_set_test_case_driver() > +{ > + if ! echo -n 1 >$DIR/config_test_case; then > + echo "$0: Unable to set to test case to driver" >&2 > + exit 1 > + fi > +} > + > +config_set_test_case_fs() > +{ > + if ! echo -n 2 >$DIR/config_test_case; then > + echo "$0: Unable to set to test case to fs" >&2 > + exit 1 > + fi > +} > + > +config_num_threads() > +{ > + if ! echo -n $1 >$DIR/config_num_threads; then > + echo "$0: Unable to set to number of threads" >&2 > + exit 1 > + fi > +} > + > +config_get_modprobe_limit() > +{ > + if [[ -f ${MODPROBE_LIMIT_FILE} ]] ; then > + MODPROBE_LIMIT=$(cat $MODPROBE_LIMIT_FILE) > + fi > + echo $MODPROBE_LIMIT > +} > + > +config_num_thread_limit_extra() > +{ > + MODPROBE_LIMIT=$(config_get_modprobe_limit) > + let EXTRA_LIMIT=$MODPROBE_LIMIT+$1 > + config_num_threads $EXTRA_LIMIT > +} > + > +# For special characters use printf directly, > +# refer to kmod_test_0001 > +config_set_driver() > +{ > + if ! echo -n $1 >$DIR/config_test_driver; then > + echo "$0: Unable to set driver" >&2 > + exit 1 > + fi > +} > + > +config_set_fs() > +{ > + if ! echo -n $1 >$DIR/config_test_fs; then > + echo "$0: Unable to set driver" >&2 > + exit 1 > + fi > +} > + > +config_get_driver() > +{ > + cat $DIR/config_test_driver > +} > + > +config_get_test_result() > +{ > + cat $DIR/test_result > +} > + > +config_reset() > +{ > + if ! echo -n "1" >"$DIR"/reset; then > + echo "$0: reset shuld have worked" >&2 > + exit 1 > + fi > +} > + > +config_show_config() > +{ > + echo "----------------------------------------------------" > + cat "$DIR"/config > + echo "----------------------------------------------------" > +} > + > +config_trigger() > +{ > + if ! echo -n "1" >"$DIR"/trigger_config 2>/dev/null; then > + echo "$1: FAIL - loading should have worked" > + config_show_config > + exit 1 > + fi > + echo "$1: OK! - loading kmod test" > +} > + > +config_trigger_want_fail() > +{ > + if echo "1" > $DIR/trigger_config 2>/dev/null; then > + echo "$1: FAIL - test case was expected to fail" > + config_show_config > + exit 1 > + fi > + echo "$1: OK! - kmod test case failed as expected" > +} > + > +config_expect_result() > +{ > + RC=$(config_get_test_result) > + RC_NAME=$(errno_val_to_name $RC) > + > + ERRNO_NAME=$2 > + ERRNO=$(errno_name_to_val $ERRNO_NAME) > + > + if [[ $ERRNO_NAME = "-ERR_ANY" ]]; then > + if [[ $RC -ge 0 ]]; then > + echo "$1: FAIL, test expects $ERRNO_NAME - got $RC_NAME ($RC)" >&2 > + config_show_config > + exit 1 > + fi > + elif [[ $RC != $ERRNO ]]; then > + echo "$1: FAIL, test expects $ERRNO_NAME ($ERRNO) - got $RC_NAME ($RC)" >&2 > + config_show_config > + exit 1 > + fi > + echo "$1: OK! - Return value: $RC ($RC_NAME), expected $ERRNO_NAME" > +} > + > +kmod_defaults_driver() > +{ > + config_reset > + modprobe -r $DEFAULT_KMOD_DRIVER > + config_set_driver $DEFAULT_KMOD_DRIVER > +} > + > +kmod_defaults_fs() > +{ > + config_reset > + modprobe -r $DEFAULT_KMOD_FS > + config_set_fs $DEFAULT_KMOD_FS > + config_set_test_case_fs > +} > + > +kmod_test_0001_driver() > +{ > + NAME='\000' > + > + kmod_defaults_driver > + config_num_threads 1 > + printf '\000' >"$DIR"/config_test_driver > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND > +} > + > +kmod_test_0001_fs() > +{ > + NAME='\000' > + > + kmod_defaults_fs > + config_num_threads 1 > + printf '\000' >"$DIR"/config_test_fs > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} -EINVAL > +} > + > +kmod_test_0001() > +{ > + kmod_test_0001_driver > + kmod_test_0001_fs > +} > + > +kmod_test_0002_driver() > +{ > + NAME="nope-$DEFAULT_KMOD_DRIVER" > + > + kmod_defaults_driver > + config_set_driver $NAME > + config_num_threads 1 > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND > +} > + > +kmod_test_0002_fs() > +{ > + NAME="nope-$DEFAULT_KMOD_FS" > + > + kmod_defaults_fs > + config_set_fs $NAME > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} -EINVAL > +} > + > +kmod_test_0002() > +{ > + kmod_test_0002_driver > + kmod_test_0002_fs > +} > + > +kmod_test_0003() > +{ > + kmod_defaults_fs > + config_num_threads 1 > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} SUCCESS > +} > + > +kmod_test_0004() > +{ > + kmod_defaults_fs > + config_num_threads 2 > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} SUCCESS > +} > + > +kmod_test_0005() > +{ > + kmod_defaults_driver > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} SUCCESS > +} > + > +kmod_test_0006() > +{ > + kmod_defaults_fs > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} SUCCESS > +} > + > +kmod_test_0007() > +{ > + kmod_test_0005 > + kmod_test_0006 > +} > + > +kmod_test_0008() > +{ > + kmod_defaults_driver > + MODPROBE_LIMIT=$(config_get_modprobe_limit) > + let EXTRA=$MODPROBE_LIMIT/2 > + config_num_thread_limit_extra $EXTRA > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} -EINVAL > +} > + > +kmod_test_0009() > +{ > + kmod_defaults_fs > + #MODPROBE_LIMIT=$(config_get_modprobe_limit) > + #let EXTRA=$MODPROBE_LIMIT/3 > + config_num_thread_limit_extra 5 > + config_trigger ${FUNCNAME[0]} > + config_expect_result ${FUNCNAME[0]} -EINVAL > +} > + > +trap "test_finish" EXIT > +test_reqs > +allow_user_defaults > +load_req_mod > + > +usage() > +{ > + echo "Usage: $0 [ -t <4-number-digit> ]" > + echo "Valid tests: 0001-0011" > + echo > + echo "0001 - Simple test - 1 thread for empty string" > + echo "0002 - Simple test - 1 thread for modules/filesystems that do not exist" > + echo "0003 - Simple test - 1 thread for get_fs_type() only" > + echo "0004 - Simple test - 2 threads for get_fs_type() only" > + echo "0005 - multithreaded tests with default setup - request_module() only" > + echo "0006 - multithreaded tests with default setup - get_fs_type() only" > + echo "0007 - multithreaded tests with default setup test request_module() and get_fs_type()" > + echo "0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module()" > + echo "0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()" > + exit 1 > +} > + > +# You can ask for a specific test: > +if [[ $# > 0 ]] ; then > + if [[ $1 != "-t" ]]; then > + usage > + fi > + > + re='^[0-9]+$' > + if ! [[ $2 =~ $re ]]; then > + usage > + fi > + > + RUN_TEST=kmod_test_$2 > + $RUN_TEST > + exit 0 > +fi > + > +# Once tese are enabled please leave them as-is. Write your own test, > +# we have tons of space. > +kmod_test_0001 > +kmod_test_0002 > +kmod_test_0003 > +kmod_test_0004 > +kmod_test_0005 > +kmod_test_0006 > +kmod_test_0007 > + > +#kmod_test_0008 > +#kmod_test_0009 While it's documented in the commit log, I think a short note for each disabled test should be added here too. > + > +exit 0 > -- > 2.10.1 > -Kees -- Kees Cook Nexus Security -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
