| /* |
| * trace_events_trigger - trace event triggers |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| * |
| * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/ctype.h> |
| #include <linux/mutex.h> |
| #include <linux/slab.h> |
| |
| #include "trace.h" |
| |
| static LIST_HEAD(trigger_commands); |
| static DEFINE_MUTEX(trigger_cmd_mutex); |
| |
| void trigger_data_free(struct event_trigger_data *data) |
| { |
| if (data->cmd_ops->set_filter) |
| data->cmd_ops->set_filter(NULL, data, NULL); |
| |
| synchronize_sched(); /* make sure current triggers exit before free */ |
| kfree(data); |
| } |
| |
| /** |
| * event_triggers_call - Call triggers associated with a trace event |
| * @file: The trace_event_file associated with the event |
| * @rec: The trace entry for the event, NULL for unconditional invocation |
| * |
| * For each trigger associated with an event, invoke the trigger |
| * function registered with the associated trigger command. If rec is |
| * non-NULL, it means that the trigger requires further processing and |
| * shouldn't be unconditionally invoked. If rec is non-NULL and the |
| * trigger has a filter associated with it, rec will checked against |
| * the filter and if the record matches the trigger will be invoked. |
| * If the trigger is a 'post_trigger', meaning it shouldn't be invoked |
| * in any case until the current event is written, the trigger |
| * function isn't invoked but the bit associated with the deferred |
| * trigger is set in the return value. |
| * |
| * Returns an enum event_trigger_type value containing a set bit for |
| * any trigger that should be deferred, ETT_NONE if nothing to defer. |
| * |
| * Called from tracepoint handlers (with rcu_read_lock_sched() held). |
| * |
| * Return: an enum event_trigger_type value containing a set bit for |
| * any trigger that should be deferred, ETT_NONE if nothing to defer. |
| */ |
| enum event_trigger_type |
| event_triggers_call(struct trace_event_file *file, void *rec) |
| { |
| struct event_trigger_data *data; |
| enum event_trigger_type tt = ETT_NONE; |
| struct event_filter *filter; |
| |
| if (list_empty(&file->triggers)) |
| return tt; |
| |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| if (data->paused) |
| continue; |
| if (!rec) { |
| data->ops->func(data, rec); |
| continue; |
| } |
| filter = rcu_dereference_sched(data->filter); |
| if (filter && !filter_match_preds(filter, rec)) |
| continue; |
| if (data->cmd_ops->post_trigger) { |
| tt |= data->cmd_ops->trigger_type; |
| continue; |
| } |
| data->ops->func(data, rec); |
| } |
| return tt; |
| } |
| EXPORT_SYMBOL_GPL(event_triggers_call); |
| |
| /** |
| * event_triggers_post_call - Call 'post_triggers' for a trace event |
| * @file: The trace_event_file associated with the event |
| * @tt: enum event_trigger_type containing a set bit for each trigger to invoke |
| * @rec: The trace entry for the event |
| * |
| * For each trigger associated with an event, invoke the trigger |
| * function registered with the associated trigger command, if the |
| * corresponding bit is set in the tt enum passed into this function. |
| * See @event_triggers_call for details on how those bits are set. |
| * |
| * Called from tracepoint handlers (with rcu_read_lock_sched() held). |
| */ |
| void |
| event_triggers_post_call(struct trace_event_file *file, |
| enum event_trigger_type tt, |
| void *rec) |
| { |
| struct event_trigger_data *data; |
| |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| if (data->paused) |
| continue; |
| if (data->cmd_ops->trigger_type & tt) |
| data->ops->func(data, rec); |
| } |
| } |
| EXPORT_SYMBOL_GPL(event_triggers_post_call); |
| |
| #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL) |
| |
| static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) |
| { |
| struct trace_event_file *event_file = event_file_data(m->private); |
| |
| if (t == SHOW_AVAILABLE_TRIGGERS) |
| return NULL; |
| |
| return seq_list_next(t, &event_file->triggers, pos); |
| } |
| |
| static void *trigger_start(struct seq_file *m, loff_t *pos) |
| { |
| struct trace_event_file *event_file; |
| |
| /* ->stop() is called even if ->start() fails */ |
| mutex_lock(&event_mutex); |
| event_file = event_file_data(m->private); |
| if (unlikely(!event_file)) |
| return ERR_PTR(-ENODEV); |
| |
| if (list_empty(&event_file->triggers)) |
| return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL; |
| |
| return seq_list_start(&event_file->triggers, *pos); |
| } |
| |
| static void trigger_stop(struct seq_file *m, void *t) |
| { |
| mutex_unlock(&event_mutex); |
| } |
| |
| static int trigger_show(struct seq_file *m, void *v) |
| { |
| struct event_trigger_data *data; |
| struct event_command *p; |
| |
| if (v == SHOW_AVAILABLE_TRIGGERS) { |
| seq_puts(m, "# Available triggers:\n"); |
| seq_putc(m, '#'); |
| mutex_lock(&trigger_cmd_mutex); |
| list_for_each_entry_reverse(p, &trigger_commands, list) |
| seq_printf(m, " %s", p->name); |
| seq_putc(m, '\n'); |
| mutex_unlock(&trigger_cmd_mutex); |
| return 0; |
| } |
| |
| data = list_entry(v, struct event_trigger_data, list); |
| data->ops->print(m, data->ops, data); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations event_triggers_seq_ops = { |
| .start = trigger_start, |
| .next = trigger_next, |
| .stop = trigger_stop, |
| .show = trigger_show, |
| }; |
| |
| static int event_trigger_regex_open(struct inode *inode, struct file *file) |
| { |
| int ret = 0; |
| |
| mutex_lock(&event_mutex); |
| |
| if (unlikely(!event_file_data(file))) { |
| mutex_unlock(&event_mutex); |
| return -ENODEV; |
| } |
| |
| if ((file->f_mode & FMODE_WRITE) && |
| (file->f_flags & O_TRUNC)) { |
| struct trace_event_file *event_file; |
| struct event_command *p; |
| |
| event_file = event_file_data(file); |
| |
| list_for_each_entry(p, &trigger_commands, list) { |
| if (p->unreg_all) |
| p->unreg_all(event_file); |
| } |
| } |
| |
| if (file->f_mode & FMODE_READ) { |
| ret = seq_open(file, &event_triggers_seq_ops); |
| if (!ret) { |
| struct seq_file *m = file->private_data; |
| m->private = file; |
| } |
| } |
| |
| mutex_unlock(&event_mutex); |
| |
| return ret; |
| } |
| |
| static int trigger_process_regex(struct trace_event_file *file, char *buff) |
| { |
| char *command, *next = buff; |
| struct event_command *p; |
| int ret = -EINVAL; |
| |
| command = strsep(&next, ": \t"); |
| command = (command[0] != '!') ? command : command + 1; |
| |
| mutex_lock(&trigger_cmd_mutex); |
| list_for_each_entry(p, &trigger_commands, list) { |
| if (strcmp(p->name, command) == 0) { |
| ret = p->func(p, file, buff, command, next); |
| goto out_unlock; |
| } |
| } |
| out_unlock: |
| mutex_unlock(&trigger_cmd_mutex); |
| |
| return ret; |
| } |
| |
| static ssize_t event_trigger_regex_write(struct file *file, |
| const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| struct trace_event_file *event_file; |
| ssize_t ret; |
| char *buf; |
| |
| if (!cnt) |
| return 0; |
| |
| if (cnt >= PAGE_SIZE) |
| return -EINVAL; |
| |
| buf = memdup_user_nul(ubuf, cnt); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| strim(buf); |
| |
| mutex_lock(&event_mutex); |
| event_file = event_file_data(file); |
| if (unlikely(!event_file)) { |
| mutex_unlock(&event_mutex); |
| kfree(buf); |
| return -ENODEV; |
| } |
| ret = trigger_process_regex(event_file, buf); |
| mutex_unlock(&event_mutex); |
| |
| kfree(buf); |
| if (ret < 0) |
| goto out; |
| |
| *ppos += cnt; |
| ret = cnt; |
| out: |
| return ret; |
| } |
| |
| static int event_trigger_regex_release(struct inode *inode, struct file *file) |
| { |
| mutex_lock(&event_mutex); |
| |
| if (file->f_mode & FMODE_READ) |
| seq_release(inode, file); |
| |
| mutex_unlock(&event_mutex); |
| |
| return 0; |
| } |
| |
| static ssize_t |
| event_trigger_write(struct file *filp, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| return event_trigger_regex_write(filp, ubuf, cnt, ppos); |
| } |
| |
| static int |
| event_trigger_open(struct inode *inode, struct file *filp) |
| { |
| return event_trigger_regex_open(inode, filp); |
| } |
| |
| static int |
| event_trigger_release(struct inode *inode, struct file *file) |
| { |
| return event_trigger_regex_release(inode, file); |
| } |
| |
| const struct file_operations event_trigger_fops = { |
| .open = event_trigger_open, |
| .read = seq_read, |
| .write = event_trigger_write, |
| .llseek = tracing_lseek, |
| .release = event_trigger_release, |
| }; |
| |
| /* |
| * Currently we only register event commands from __init, so mark this |
| * __init too. |
| */ |
| __init int register_event_command(struct event_command *cmd) |
| { |
| struct event_command *p; |
| int ret = 0; |
| |
| mutex_lock(&trigger_cmd_mutex); |
| list_for_each_entry(p, &trigger_commands, list) { |
| if (strcmp(cmd->name, p->name) == 0) { |
| ret = -EBUSY; |
| goto out_unlock; |
| } |
| } |
| list_add(&cmd->list, &trigger_commands); |
| out_unlock: |
| mutex_unlock(&trigger_cmd_mutex); |
| |
| return ret; |
| } |
| |
| /* |
| * Currently we only unregister event commands from __init, so mark |
| * this __init too. |
| */ |
| static __init int unregister_event_command(struct event_command *cmd) |
| { |
| struct event_command *p, *n; |
| int ret = -ENODEV; |
| |
| mutex_lock(&trigger_cmd_mutex); |
| list_for_each_entry_safe(p, n, &trigger_commands, list) { |
| if (strcmp(cmd->name, p->name) == 0) { |
| ret = 0; |
| list_del_init(&p->list); |
| goto out_unlock; |
| } |
| } |
| out_unlock: |
| mutex_unlock(&trigger_cmd_mutex); |
| |
| return ret; |
| } |
| |
| /** |
| * event_trigger_print - Generic event_trigger_ops @print implementation |
| * @name: The name of the event trigger |
| * @m: The seq_file being printed to |
| * @data: Trigger-specific data |
| * @filter_str: filter_str to print, if present |
| * |
| * Common implementation for event triggers to print themselves. |
| * |
| * Usually wrapped by a function that simply sets the @name of the |
| * trigger command and then invokes this. |
| * |
| * Return: 0 on success, errno otherwise |
| */ |
| static int |
| event_trigger_print(const char *name, struct seq_file *m, |
| void *data, char *filter_str) |
| { |
| long count = (long)data; |
| |
| seq_puts(m, name); |
| |
| if (count == -1) |
| seq_puts(m, ":unlimited"); |
| else |
| seq_printf(m, ":count=%ld", count); |
| |
| if (filter_str) |
| seq_printf(m, " if %s\n", filter_str); |
| else |
| seq_putc(m, '\n'); |
| |
| return 0; |
| } |
| |
| /** |
| * event_trigger_init - Generic event_trigger_ops @init implementation |
| * @ops: The trigger ops associated with the trigger |
| * @data: Trigger-specific data |
| * |
| * Common implementation of event trigger initialization. |
| * |
| * Usually used directly as the @init method in event trigger |
| * implementations. |
| * |
| * Return: 0 on success, errno otherwise |
| */ |
| int event_trigger_init(struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| data->ref++; |
| return 0; |
| } |
| |
| /** |
| * event_trigger_free - Generic event_trigger_ops @free implementation |
| * @ops: The trigger ops associated with the trigger |
| * @data: Trigger-specific data |
| * |
| * Common implementation of event trigger de-initialization. |
| * |
| * Usually used directly as the @free method in event trigger |
| * implementations. |
| */ |
| static void |
| event_trigger_free(struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| if (WARN_ON_ONCE(data->ref <= 0)) |
| return; |
| |
| data->ref--; |
| if (!data->ref) |
| trigger_data_free(data); |
| } |
| |
| int trace_event_trigger_enable_disable(struct trace_event_file *file, |
| int trigger_enable) |
| { |
| int ret = 0; |
| |
| if (trigger_enable) { |
| if (atomic_inc_return(&file->tm_ref) > 1) |
| return ret; |
| set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); |
| ret = trace_event_enable_disable(file, 1, 1); |
| } else { |
| if (atomic_dec_return(&file->tm_ref) > 0) |
| return ret; |
| clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); |
| ret = trace_event_enable_disable(file, 0, 1); |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * clear_event_triggers - Clear all triggers associated with a trace array |
| * @tr: The trace array to clear |
| * |
| * For each trigger, the triggering event has its tm_ref decremented |
| * via trace_event_trigger_enable_disable(), and any associated event |
| * (in the case of enable/disable_event triggers) will have its sm_ref |
| * decremented via free()->trace_event_enable_disable(). That |
| * combination effectively reverses the soft-mode/trigger state added |
| * by trigger registration. |
| * |
| * Must be called with event_mutex held. |
| */ |
| void |
| clear_event_triggers(struct trace_array *tr) |
| { |
| struct trace_event_file *file; |
| |
| list_for_each_entry(file, &tr->events, list) { |
| struct event_trigger_data *data; |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| trace_event_trigger_enable_disable(file, 0); |
| if (data->ops->free) |
| data->ops->free(data->ops, data); |
| } |
| } |
| } |
| |
| /** |
| * update_cond_flag - Set or reset the TRIGGER_COND bit |
| * @file: The trace_event_file associated with the event |
| * |
| * If an event has triggers and any of those triggers has a filter or |
| * a post_trigger, trigger invocation needs to be deferred until after |
| * the current event has logged its data, and the event should have |
| * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be |
| * cleared. |
| */ |
| void update_cond_flag(struct trace_event_file *file) |
| { |
| struct event_trigger_data *data; |
| bool set_cond = false; |
| |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| if (data->filter || data->cmd_ops->post_trigger || |
| data->cmd_ops->needs_rec) { |
| set_cond = true; |
| break; |
| } |
| } |
| |
| if (set_cond) |
| set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); |
| else |
| clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); |
| } |
| |
| /** |
| * register_trigger - Generic event_command @reg implementation |
| * @glob: The raw string used to register the trigger |
| * @ops: The trigger ops associated with the trigger |
| * @data: Trigger-specific data to associate with the trigger |
| * @file: The trace_event_file associated with the event |
| * |
| * Common implementation for event trigger registration. |
| * |
| * Usually used directly as the @reg method in event command |
| * implementations. |
| * |
| * Return: 0 on success, errno otherwise |
| */ |
| static int register_trigger(char *glob, struct event_trigger_ops *ops, |
| struct event_trigger_data *data, |
| struct trace_event_file *file) |
| { |
| struct event_trigger_data *test; |
| int ret = 0; |
| |
| list_for_each_entry_rcu(test, &file->triggers, list) { |
| if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) { |
| ret = -EEXIST; |
| goto out; |
| } |
| } |
| |
| if (data->ops->init) { |
| ret = data->ops->init(data->ops, data); |
| if (ret < 0) |
| goto out; |
| } |
| |
| list_add_rcu(&data->list, &file->triggers); |
| ret++; |
| |
| update_cond_flag(file); |
| if (trace_event_trigger_enable_disable(file, 1) < 0) { |
| list_del_rcu(&data->list); |
| update_cond_flag(file); |
| ret--; |
| } |
| out: |
| return ret; |
| } |
| |
| /** |
| * unregister_trigger - Generic event_command @unreg implementation |
| * @glob: The raw string used to register the trigger |
| * @ops: The trigger ops associated with the trigger |
| * @test: Trigger-specific data used to find the trigger to remove |
| * @file: The trace_event_file associated with the event |
| * |
| * Common implementation for event trigger unregistration. |
| * |
| * Usually used directly as the @unreg method in event command |
| * implementations. |
| */ |
| void unregister_trigger(char *glob, struct event_trigger_ops *ops, |
| struct event_trigger_data *test, |
| struct trace_event_file *file) |
| { |
| struct event_trigger_data *data; |
| bool unregistered = false; |
| |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { |
| unregistered = true; |
| list_del_rcu(&data->list); |
| trace_event_trigger_enable_disable(file, 0); |
| update_cond_flag(file); |
| break; |
| } |
| } |
| |
| if (unregistered && data->ops->free) |
| data->ops->free(data->ops, data); |
| } |
| |
| /** |
| * event_trigger_callback - Generic event_command @func implementation |
| * @cmd_ops: The command ops, used for trigger registration |
| * @file: The trace_event_file associated with the event |
| * @glob: The raw string used to register the trigger |
| * @cmd: The cmd portion of the string used to register the trigger |
| * @param: The params portion of the string used to register the trigger |
| * |
| * Common implementation for event command parsing and trigger |
| * instantiation. |
| * |
| * Usually used directly as the @func method in event command |
| * implementations. |
| * |
| * Return: 0 on success, errno otherwise |
| */ |
| static int |
| event_trigger_callback(struct event_command *cmd_ops, |
| struct trace_event_file *file, |
| char *glob, char *cmd, char *param) |
| { |
| struct event_trigger_data *trigger_data; |
| struct event_trigger_ops *trigger_ops; |
| char *trigger = NULL; |
| char *number; |
| int ret; |
| |
| /* separate the trigger from the filter (t:n [if filter]) */ |
| if (param && isdigit(param[0])) |
| trigger = strsep(¶m, " \t"); |
| |
| trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); |
| |
| ret = -ENOMEM; |
| trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); |
| if (!trigger_data) |
| goto out; |
| |
| trigger_data->count = -1; |
| trigger_data->ops = trigger_ops; |
| trigger_data->cmd_ops = cmd_ops; |
| INIT_LIST_HEAD(&trigger_data->list); |
| |
| if (glob[0] == '!') { |
| cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); |
| kfree(trigger_data); |
| ret = 0; |
| goto out; |
| } |
| |
| if (trigger) { |
| number = strsep(&trigger, ":"); |
| |
| ret = -EINVAL; |
| if (!strlen(number)) |
| goto out_free; |
| |
| /* |
| * We use the callback data field (which is a pointer) |
| * as our counter. |
| */ |
| ret = kstrtoul(number, 0, &trigger_data->count); |
| if (ret) |
| goto out_free; |
| } |
| |
| if (!param) /* if param is non-empty, it's supposed to be a filter */ |
| goto out_reg; |
| |
| if (!cmd_ops->set_filter) |
| goto out_reg; |
| |
| ret = cmd_ops->set_filter(param, trigger_data, file); |
| if (ret < 0) |
| goto out_free; |
| |
| out_reg: |
| ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); |
| /* |
| * The above returns on success the # of functions enabled, |
| * but if it didn't find any functions it returns zero. |
| * Consider no functions a failure too. |
| */ |
| if (!ret) { |
| ret = -ENOENT; |
| goto out_free; |
| } else if (ret < 0) |
| goto out_free; |
| ret = 0; |
| out: |
| return ret; |
| |
| out_free: |
| if (cmd_ops->set_filter) |
| cmd_ops->set_filter(NULL, trigger_data, NULL); |
| kfree(trigger_data); |
| goto out; |
| } |
| |
| /** |
| * set_trigger_filter - Generic event_command @set_filter implementation |
| * @filter_str: The filter string for the trigger, NULL to remove filter |
| * @trigger_data: Trigger-specific data |
| * @file: The trace_event_file associated with the event |
| * |
| * Common implementation for event command filter parsing and filter |
| * instantiation. |
| * |
| * Usually used directly as the @set_filter method in event command |
| * implementations. |
| * |
| * Also used to remove a filter (if filter_str = NULL). |
| * |
| * Return: 0 on success, errno otherwise |
| */ |
| int set_trigger_filter(char *filter_str, |
| struct event_trigger_data *trigger_data, |
| struct trace_event_file *file) |
| { |
| struct event_trigger_data *data = trigger_data; |
| struct event_filter *filter = NULL, *tmp; |
| int ret = -EINVAL; |
| char *s; |
| |
| if (!filter_str) /* clear the current filter */ |
| goto assign; |
| |
| s = strsep(&filter_str, " \t"); |
| |
| if (!strlen(s) || strcmp(s, "if") != 0) |
| goto out; |
| |
| if (!filter_str) |
| goto out; |
| |
| /* The filter is for the 'trigger' event, not the triggered event */ |
| ret = create_event_filter(file->event_call, filter_str, false, &filter); |
| if (ret) |
| goto out; |
| assign: |
| tmp = rcu_access_pointer(data->filter); |
| |
| rcu_assign_pointer(data->filter, filter); |
| |
| if (tmp) { |
| /* Make sure the call is done with the filter */ |
| synchronize_sched(); |
| free_event_filter(tmp); |
| } |
| |
| kfree(data->filter_str); |
| data->filter_str = NULL; |
| |
| if (filter_str) { |
| data->filter_str = kstrdup(filter_str, GFP_KERNEL); |
| if (!data->filter_str) { |
| free_event_filter(rcu_access_pointer(data->filter)); |
| data->filter = NULL; |
| ret = -ENOMEM; |
| } |
| } |
| out: |
| return ret; |
| } |
| |
| static void |
| traceon_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (tracing_is_on()) |
| return; |
| |
| tracing_on(); |
| } |
| |
| static void |
| traceon_count_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (tracing_is_on()) |
| return; |
| |
| if (!data->count) |
| return; |
| |
| if (data->count != -1) |
| (data->count)--; |
| |
| tracing_on(); |
| } |
| |
| static void |
| traceoff_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (!tracing_is_on()) |
| return; |
| |
| tracing_off(); |
| } |
| |
| static void |
| traceoff_count_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (!tracing_is_on()) |
| return; |
| |
| if (!data->count) |
| return; |
| |
| if (data->count != -1) |
| (data->count)--; |
| |
| tracing_off(); |
| } |
| |
| static int |
| traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| return event_trigger_print("traceon", m, (void *)data->count, |
| data->filter_str); |
| } |
| |
| static int |
| traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| return event_trigger_print("traceoff", m, (void *)data->count, |
| data->filter_str); |
| } |
| |
| static struct event_trigger_ops traceon_trigger_ops = { |
| .func = traceon_trigger, |
| .print = traceon_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops traceon_count_trigger_ops = { |
| .func = traceon_count_trigger, |
| .print = traceon_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops traceoff_trigger_ops = { |
| .func = traceoff_trigger, |
| .print = traceoff_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops traceoff_count_trigger_ops = { |
| .func = traceoff_count_trigger, |
| .print = traceoff_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops * |
| onoff_get_trigger_ops(char *cmd, char *param) |
| { |
| struct event_trigger_ops *ops; |
| |
| /* we register both traceon and traceoff to this callback */ |
| if (strcmp(cmd, "traceon") == 0) |
| ops = param ? &traceon_count_trigger_ops : |
| &traceon_trigger_ops; |
| else |
| ops = param ? &traceoff_count_trigger_ops : |
| &traceoff_trigger_ops; |
| |
| return ops; |
| } |
| |
| static struct event_command trigger_traceon_cmd = { |
| .name = "traceon", |
| .trigger_type = ETT_TRACE_ONOFF, |
| .func = event_trigger_callback, |
| .reg = register_trigger, |
| .unreg = unregister_trigger, |
| .get_trigger_ops = onoff_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| static struct event_command trigger_traceoff_cmd = { |
| .name = "traceoff", |
| .trigger_type = ETT_TRACE_ONOFF, |
| .func = event_trigger_callback, |
| .reg = register_trigger, |
| .unreg = unregister_trigger, |
| .get_trigger_ops = onoff_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| #ifdef CONFIG_TRACER_SNAPSHOT |
| static void |
| snapshot_trigger(struct event_trigger_data *data, void *rec) |
| { |
| tracing_snapshot(); |
| } |
| |
| static void |
| snapshot_count_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (!data->count) |
| return; |
| |
| if (data->count != -1) |
| (data->count)--; |
| |
| snapshot_trigger(data, rec); |
| } |
| |
| static int |
| register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, |
| struct event_trigger_data *data, |
| struct trace_event_file *file) |
| { |
| int ret = register_trigger(glob, ops, data, file); |
| |
| if (ret > 0 && tracing_alloc_snapshot() != 0) { |
| unregister_trigger(glob, ops, data, file); |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| |
| static int |
| snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| return event_trigger_print("snapshot", m, (void *)data->count, |
| data->filter_str); |
| } |
| |
| static struct event_trigger_ops snapshot_trigger_ops = { |
| .func = snapshot_trigger, |
| .print = snapshot_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops snapshot_count_trigger_ops = { |
| .func = snapshot_count_trigger, |
| .print = snapshot_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops * |
| snapshot_get_trigger_ops(char *cmd, char *param) |
| { |
| return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops; |
| } |
| |
| static struct event_command trigger_snapshot_cmd = { |
| .name = "snapshot", |
| .trigger_type = ETT_SNAPSHOT, |
| .func = event_trigger_callback, |
| .reg = register_snapshot_trigger, |
| .unreg = unregister_trigger, |
| .get_trigger_ops = snapshot_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| static __init int register_trigger_snapshot_cmd(void) |
| { |
| int ret; |
| |
| ret = register_event_command(&trigger_snapshot_cmd); |
| WARN_ON(ret < 0); |
| |
| return ret; |
| } |
| #else |
| static __init int register_trigger_snapshot_cmd(void) { return 0; } |
| #endif /* CONFIG_TRACER_SNAPSHOT */ |
| |
| #ifdef CONFIG_STACKTRACE |
| /* |
| * Skip 3: |
| * stacktrace_trigger() |
| * event_triggers_post_call() |
| * trace_event_raw_event_xxx() |
| */ |
| #define STACK_SKIP 3 |
| |
| static void |
| stacktrace_trigger(struct event_trigger_data *data, void *rec) |
| { |
| trace_dump_stack(STACK_SKIP); |
| } |
| |
| static void |
| stacktrace_count_trigger(struct event_trigger_data *data, void *rec) |
| { |
| if (!data->count) |
| return; |
| |
| if (data->count != -1) |
| (data->count)--; |
| |
| stacktrace_trigger(data, rec); |
| } |
| |
| static int |
| stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| return event_trigger_print("stacktrace", m, (void *)data->count, |
| data->filter_str); |
| } |
| |
| static struct event_trigger_ops stacktrace_trigger_ops = { |
| .func = stacktrace_trigger, |
| .print = stacktrace_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops stacktrace_count_trigger_ops = { |
| .func = stacktrace_count_trigger, |
| .print = stacktrace_trigger_print, |
| .init = event_trigger_init, |
| .free = event_trigger_free, |
| }; |
| |
| static struct event_trigger_ops * |
| stacktrace_get_trigger_ops(char *cmd, char *param) |
| { |
| return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops; |
| } |
| |
| static struct event_command trigger_stacktrace_cmd = { |
| .name = "stacktrace", |
| .trigger_type = ETT_STACKTRACE, |
| .post_trigger = true, |
| .func = event_trigger_callback, |
| .reg = register_trigger, |
| .unreg = unregister_trigger, |
| .get_trigger_ops = stacktrace_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| static __init int register_trigger_stacktrace_cmd(void) |
| { |
| int ret; |
| |
| ret = register_event_command(&trigger_stacktrace_cmd); |
| WARN_ON(ret < 0); |
| |
| return ret; |
| } |
| #else |
| static __init int register_trigger_stacktrace_cmd(void) { return 0; } |
| #endif /* CONFIG_STACKTRACE */ |
| |
| static __init void unregister_trigger_traceon_traceoff_cmds(void) |
| { |
| unregister_event_command(&trigger_traceon_cmd); |
| unregister_event_command(&trigger_traceoff_cmd); |
| } |
| |
| /* Avoid typos */ |
| #define ENABLE_EVENT_STR "enable_event" |
| #define DISABLE_EVENT_STR "disable_event" |
| |
| struct enable_trigger_data { |
| struct trace_event_file *file; |
| bool enable; |
| }; |
| |
| static void |
| event_enable_trigger(struct event_trigger_data *data, void *rec) |
| { |
| struct enable_trigger_data *enable_data = data->private_data; |
| |
| if (enable_data->enable) |
| clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
| else |
| set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
| } |
| |
| static void |
| event_enable_count_trigger(struct event_trigger_data *data, void *rec) |
| { |
| struct enable_trigger_data *enable_data = data->private_data; |
| |
| if (!data->count) |
| return; |
| |
| /* Skip if the event is in a state we want to switch to */ |
| if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) |
| return; |
| |
| if (data->count != -1) |
| (data->count)--; |
| |
| event_enable_trigger(data, rec); |
| } |
| |
| static int |
| event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| struct enable_trigger_data *enable_data = data->private_data; |
| |
| seq_printf(m, "%s:%s:%s", |
| enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, |
| enable_data->file->event_call->class->system, |
| trace_event_name(enable_data->file->event_call)); |
| |
| if (data->count == -1) |
| seq_puts(m, ":unlimited"); |
| else |
| seq_printf(m, ":count=%ld", data->count); |
| |
| if (data->filter_str) |
| seq_printf(m, " if %s\n", data->filter_str); |
| else |
| seq_putc(m, '\n'); |
| |
| return 0; |
| } |
| |
| static void |
| event_enable_trigger_free(struct event_trigger_ops *ops, |
| struct event_trigger_data *data) |
| { |
| struct enable_trigger_data *enable_data = data->private_data; |
| |
| if (WARN_ON_ONCE(data->ref <= 0)) |
| return; |
| |
| data->ref--; |
| if (!data->ref) { |
| /* Remove the SOFT_MODE flag */ |
| trace_event_enable_disable(enable_data->file, 0, 1); |
| module_put(enable_data->file->event_call->mod); |
| trigger_data_free(data); |
| kfree(enable_data); |
| } |
| } |
| |
| static struct event_trigger_ops event_enable_trigger_ops = { |
| .func = event_enable_trigger, |
| .print = event_enable_trigger_print, |
| .init = event_trigger_init, |
| .free = event_enable_trigger_free, |
| }; |
| |
| static struct event_trigger_ops event_enable_count_trigger_ops = { |
| .func = event_enable_count_trigger, |
| .print = event_enable_trigger_print, |
| .init = event_trigger_init, |
| .free = event_enable_trigger_free, |
| }; |
| |
| static struct event_trigger_ops event_disable_trigger_ops = { |
| .func = event_enable_trigger, |
| .print = event_enable_trigger_print, |
| .init = event_trigger_init, |
| .free = event_enable_trigger_free, |
| }; |
| |
| static struct event_trigger_ops event_disable_count_trigger_ops = { |
| .func = event_enable_count_trigger, |
| .print = event_enable_trigger_print, |
| .init = event_trigger_init, |
| .free = event_enable_trigger_free, |
| }; |
| |
| static int |
| event_enable_trigger_func(struct event_command *cmd_ops, |
| struct trace_event_file *file, |
| char *glob, char *cmd, char *param) |
| { |
| struct trace_event_file *event_enable_file; |
| struct enable_trigger_data *enable_data; |
| struct event_trigger_data *trigger_data; |
| struct event_trigger_ops *trigger_ops; |
| struct trace_array *tr = file->tr; |
| const char *system; |
| const char *event; |
| char *trigger; |
| char *number; |
| bool enable; |
| int ret; |
| |
| if (!param) |
| return -EINVAL; |
| |
| /* separate the trigger from the filter (s:e:n [if filter]) */ |
| trigger = strsep(¶m, " \t"); |
| if (!trigger) |
| return -EINVAL; |
| |
| system = strsep(&trigger, ":"); |
| if (!trigger) |
| return -EINVAL; |
| |
| event = strsep(&trigger, ":"); |
| |
| ret = -EINVAL; |
| event_enable_file = find_event_file(tr, system, event); |
| if (!event_enable_file) |
| goto out; |
| |
| enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; |
| |
| trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); |
| |
| ret = -ENOMEM; |
| trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); |
| if (!trigger_data) |
| goto out; |
| |
| enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL); |
| if (!enable_data) { |
| kfree(trigger_data); |
| goto out; |
| } |
| |
| trigger_data->count = -1; |
| trigger_data->ops = trigger_ops; |
| trigger_data->cmd_ops = cmd_ops; |
| INIT_LIST_HEAD(&trigger_data->list); |
| RCU_INIT_POINTER(trigger_data->filter, NULL); |
| |
| enable_data->enable = enable; |
| enable_data->file = event_enable_file; |
| trigger_data->private_data = enable_data; |
| |
| if (glob[0] == '!') { |
| cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); |
| kfree(trigger_data); |
| kfree(enable_data); |
| ret = 0; |
| goto out; |
| } |
| |
| if (trigger) { |
| number = strsep(&trigger, ":"); |
| |
| ret = -EINVAL; |
| if (!strlen(number)) |
| goto out_free; |
| |
| /* |
| * We use the callback data field (which is a pointer) |
| * as our counter. |
| */ |
| ret = kstrtoul(number, 0, &trigger_data->count); |
| if (ret) |
| goto out_free; |
| } |
| |
| if (!param) /* if param is non-empty, it's supposed to be a filter */ |
| goto out_reg; |
| |
| if (!cmd_ops->set_filter) |
| goto out_reg; |
| |
| ret = cmd_ops->set_filter(param, trigger_data, file); |
| if (ret < 0) |
| goto out_free; |
| |
| out_reg: |
| /* Don't let event modules unload while probe registered */ |
| ret = try_module_get(event_enable_file->event_call->mod); |
| if (!ret) { |
| ret = -EBUSY; |
| goto out_free; |
| } |
| |
| ret = trace_event_enable_disable(event_enable_file, 1, 1); |
| if (ret < 0) |
| goto out_put; |
| ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); |
| /* |
| * The above returns on success the # of functions enabled, |
| * but if it didn't find any functions it returns zero. |
| * Consider no functions a failure too. |
| */ |
| if (!ret) { |
| ret = -ENOENT; |
| goto out_disable; |
| } else if (ret < 0) |
| goto out_disable; |
| /* Just return zero, not the number of enabled functions */ |
| ret = 0; |
| out: |
| return ret; |
| |
| out_disable: |
| trace_event_enable_disable(event_enable_file, 0, 1); |
| out_put: |
| module_put(event_enable_file->event_call->mod); |
| out_free: |
| if (cmd_ops->set_filter) |
| cmd_ops->set_filter(NULL, trigger_data, NULL); |
| kfree(trigger_data); |
| kfree(enable_data); |
| goto out; |
| } |
| |
| static int event_enable_register_trigger(char *glob, |
| struct event_trigger_ops *ops, |
| struct event_trigger_data *data, |
| struct trace_event_file *file) |
| { |
| struct enable_trigger_data *enable_data = data->private_data; |
| struct enable_trigger_data *test_enable_data; |
| struct event_trigger_data *test; |
| int ret = 0; |
| |
| list_for_each_entry_rcu(test, &file->triggers, list) { |
| test_enable_data = test->private_data; |
| if (test_enable_data && |
| (test_enable_data->file == enable_data->file)) { |
| ret = -EEXIST; |
| goto out; |
| } |
| } |
| |
| if (data->ops->init) { |
| ret = data->ops->init(data->ops, data); |
| if (ret < 0) |
| goto out; |
| } |
| |
| list_add_rcu(&data->list, &file->triggers); |
| ret++; |
| |
| update_cond_flag(file); |
| if (trace_event_trigger_enable_disable(file, 1) < 0) { |
| list_del_rcu(&data->list); |
| update_cond_flag(file); |
| ret--; |
| } |
| out: |
| return ret; |
| } |
| |
| static void event_enable_unregister_trigger(char *glob, |
| struct event_trigger_ops *ops, |
| struct event_trigger_data *test, |
| struct trace_event_file *file) |
| { |
| struct enable_trigger_data *test_enable_data = test->private_data; |
| struct enable_trigger_data *enable_data; |
| struct event_trigger_data *data; |
| bool unregistered = false; |
| |
| list_for_each_entry_rcu(data, &file->triggers, list) { |
| enable_data = data->private_data; |
| if (enable_data && |
| (enable_data->file == test_enable_data->file)) { |
| unregistered = true; |
| list_del_rcu(&data->list); |
| trace_event_trigger_enable_disable(file, 0); |
| update_cond_flag(file); |
| break; |
| } |
| } |
| |
| if (unregistered && data->ops->free) |
| data->ops->free(data->ops, data); |
| } |
| |
| static struct event_trigger_ops * |
| event_enable_get_trigger_ops(char *cmd, char *param) |
| { |
| struct event_trigger_ops *ops; |
| bool enable; |
| |
| enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; |
| |
| if (enable) |
| ops = param ? &event_enable_count_trigger_ops : |
| &event_enable_trigger_ops; |
| else |
| ops = param ? &event_disable_count_trigger_ops : |
| &event_disable_trigger_ops; |
| |
| return ops; |
| } |
| |
| static struct event_command trigger_enable_cmd = { |
| .name = ENABLE_EVENT_STR, |
| .trigger_type = ETT_EVENT_ENABLE, |
| .func = event_enable_trigger_func, |
| .reg = event_enable_register_trigger, |
| .unreg = event_enable_unregister_trigger, |
| .get_trigger_ops = event_enable_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| static struct event_command trigger_disable_cmd = { |
| .name = DISABLE_EVENT_STR, |
| .trigger_type = ETT_EVENT_ENABLE, |
| .func = event_enable_trigger_func, |
| .reg = event_enable_register_trigger, |
| .unreg = event_enable_unregister_trigger, |
| .get_trigger_ops = event_enable_get_trigger_ops, |
| .set_filter = set_trigger_filter, |
| }; |
| |
| static __init void unregister_trigger_enable_disable_cmds(void) |
| { |
| unregister_event_command(&trigger_enable_cmd); |
| unregister_event_command(&trigger_disable_cmd); |
| } |
| |
| static __init int register_trigger_enable_disable_cmds(void) |
| { |
| int ret; |
| |
| ret = register_event_command(&trigger_enable_cmd); |
| if (WARN_ON(ret < 0)) |
| return ret; |
| ret = register_event_command(&trigger_disable_cmd); |
| if (WARN_ON(ret < 0)) |
| unregister_trigger_enable_disable_cmds(); |
| |
| return ret; |
| } |
| |
| static __init int register_trigger_traceon_traceoff_cmds(void) |
| { |
| int ret; |
| |
| ret = register_event_command(&trigger_traceon_cmd); |
| if (WARN_ON(ret < 0)) |
| return ret; |
| ret = register_event_command(&trigger_traceoff_cmd); |
| if (WARN_ON(ret < 0)) |
| unregister_trigger_traceon_traceoff_cmds(); |
| |
| return ret; |
| } |
| |
| __init int register_trigger_cmds(void) |
| { |
| register_trigger_traceon_traceoff_cmds(); |
| register_trigger_snapshot_cmd(); |
| register_trigger_stacktrace_cmd(); |
| register_trigger_enable_disable_cmds(); |
| |
| return 0; |
| } |