From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- lib/test_kmod.c | 1231 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1231 insertions(+) create mode 100644 lib/test_kmod.c (limited to 'lib/test_kmod.c') diff --git a/lib/test_kmod.c b/lib/test_kmod.c new file mode 100644 index 000000000..f0dd09286 --- /dev/null +++ b/lib/test_kmod.c @@ -0,0 +1,1231 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +/* + * kmod stress test driver + * + * Copyright (C) 2017 Luis R. Rodriguez + */ +#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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TEST_START_NUM_THREADS 50 +#define TEST_START_DRIVER "test_module" +#define TEST_START_TEST_CASE TEST_KMOD_DRIVER + +static bool force_init_test = false; +module_param(force_init_test, bool_enable_only, 0444); +MODULE_PARM_DESC(force_init_test, + "Force kicking a test immediately after driver loads"); +static char *start_driver; +module_param(start_driver, charp, 0444); +MODULE_PARM_DESC(start_driver, + "Module/driver to use for the testing after driver loads"); +static char *start_test_fs; +module_param(start_test_fs, charp, 0444); +MODULE_PARM_DESC(start_test_fs, + "File system to use for the testing 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: + if (!config->test_fs) { + dev_warn(test_dev->dev, + "No fs type specified, can't run the test\n"); + return -EINVAL; + } + 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) +{ + struct test_config *config = &test_dev->config; + + mutex_lock(&test_dev->config_mutex); + + switch (test_case) { + case TEST_KMOD_DRIVER: + break; + case TEST_KMOD_FS_TYPE: + if (!config->test_fs) { + mutex_unlock(&test_dev->config_mutex); + return 0; + } + break; + default: + mutex_unlock(&test_dev->config_mutex); + return -EINVAL; + } + + config->test_case = test_case; + + mutex_unlock(&test_dev->config_mutex); + + 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; + const char *test_start_driver = start_driver ? start_driver : + TEST_START_DRIVER; + 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; + + + if (start_test_fs) { + copied = config_copy_test_fs(config, start_test_fs, + strlen(start_test_fs)); + if (copied != strlen(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); + if (WARN_ON(ret)) + return ret; + + ret = trigger_config_run_type(test_dev, TEST_KMOD_FS_TYPE); + 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 "); +MODULE_DESCRIPTION("kmod stress test driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1