| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Steven Rostedt | 9830 | 73.29% | 125 | 54.35% |
| Li Zefan | 869 | 6.48% | 21 | 9.13% |
| Tom Zanussi | 700 | 5.22% | 16 | 6.96% |
| Oleg Nesterov | 567 | 4.23% | 13 | 5.65% |
| Masami Hiramatsu | 170 | 1.27% | 9 | 3.91% |
| Joel A Fernandes | 163 | 1.22% | 2 | 0.87% |
| Lai Jiangshan | 120 | 0.89% | 1 | 0.43% |
| Alexander Z Lam | 119 | 0.89% | 2 | 0.87% |
| Peter Zijlstra | 117 | 0.87% | 2 | 0.87% |
| Jovi Zhangwei | 110 | 0.82% | 3 | 1.30% |
| Ezequiel García | 99 | 0.74% | 1 | 0.43% |
| Mathieu Desnoyers | 80 | 0.60% | 1 | 0.43% |
| Daniel Wagner | 75 | 0.56% | 1 | 0.43% |
| Jiri Olsa | 66 | 0.49% | 3 | 1.30% |
| Zhao Lei | 56 | 0.42% | 2 | 0.87% |
| Alexei Starovoitov | 50 | 0.37% | 1 | 0.43% |
| Yoshihiro Yunomae | 42 | 0.31% | 1 | 0.43% |
| Arnd Bergmann | 30 | 0.22% | 1 | 0.43% |
| Fabian Frederick | 26 | 0.19% | 1 | 0.43% |
| JoonSoo Kim | 24 | 0.18% | 1 | 0.43% |
| Geyslan G. Bem | 19 | 0.14% | 1 | 0.43% |
| Al Viro | 17 | 0.13% | 2 | 0.87% |
| Jeremy Linton | 13 | 0.10% | 3 | 1.30% |
| Yuanhan Liu | 8 | 0.06% | 2 | 0.87% |
| Tejun Heo | 6 | 0.04% | 2 | 0.87% |
| Linus Torvalds | 6 | 0.04% | 1 | 0.43% |
| Peter Hüwe | 6 | 0.04% | 1 | 0.43% |
| David Howells | 5 | 0.04% | 1 | 0.43% |
| Frédéric Weisbecker | 5 | 0.04% | 3 | 1.30% |
| Rasmus Villemoes | 5 | 0.04% | 2 | 0.87% |
| Namhyung Kim | 4 | 0.03% | 1 | 0.43% |
| Jason Baron | 2 | 0.01% | 1 | 0.43% |
| Xiao Guangrong | 2 | 0.01% | 1 | 0.43% |
| Chunyu Hu | 1 | 0.01% | 1 | 0.43% |
| Harsh Prateek Bora | 1 | 0.01% | 1 | 0.43% |
| Total | 13413 | 230 |
// SPDX-License-Identifier: GPL-2.0 /* * event tracer * * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> * * - Added format output of fields of the trace point. * This was based off of work by Tom Zanussi <tzanussi@gmail.com>. * */ #define pr_fmt(fmt) fmt #include <linux/workqueue.h> #include <linux/spinlock.h> #include <linux/kthread.h> #include <linux/tracefs.h> #include <linux/uaccess.h> #include <linux/module.h> #include <linux/ctype.h> #include <linux/sort.h> #include <linux/slab.h> #include <linux/delay.h> #include <trace/events/sched.h> #include <asm/setup.h> #include "trace_output.h" #undef TRACE_SYSTEM #define TRACE_SYSTEM "TRACE_SYSTEM" DEFINE_MUTEX(event_mutex); LIST_HEAD(ftrace_events); static LIST_HEAD(ftrace_generic_fields); static LIST_HEAD(ftrace_common_fields); #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO) static struct kmem_cache *field_cachep; static struct kmem_cache *file_cachep; static inline int system_refcount(struct event_subsystem *system) { return system->ref_count; } static int system_refcount_inc(struct event_subsystem *system) { return system->ref_count++; } static int system_refcount_dec(struct event_subsystem *system) { return --system->ref_count; } /* Double loops, do not use break, only goto's work */ #define do_for_each_event_file(tr, file) \ list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ list_for_each_entry(file, &tr->events, list) #define do_for_each_event_file_safe(tr, file) \ list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ struct trace_event_file *___n; \ list_for_each_entry_safe(file, ___n, &tr->events, list) #define while_for_each_event_file() \ } static struct list_head * trace_get_fields(struct trace_event_call *event_call) { if (!event_call->class->get_fields) return &event_call->class->fields; return event_call->class->get_fields(event_call); } static struct ftrace_event_field * __find_event_field(struct list_head *head, char *name) { struct ftrace_event_field *field; list_for_each_entry(field, head, link) { if (!strcmp(field->name, name)) return field; } return NULL; } struct ftrace_event_field * trace_find_event_field(struct trace_event_call *call, char *name) { struct ftrace_event_field *field; struct list_head *head; head = trace_get_fields(call); field = __find_event_field(head, name); if (field) return field; field = __find_event_field(&ftrace_generic_fields, name); if (field) return field; return __find_event_field(&ftrace_common_fields, name); } static int __trace_define_field(struct list_head *head, const char *type, const char *name, int offset, int size, int is_signed, int filter_type) { struct ftrace_event_field *field; field = kmem_cache_alloc(field_cachep, GFP_TRACE); if (!field) return -ENOMEM; field->name = name; field->type = type; if (filter_type == FILTER_OTHER) field->filter_type = filter_assign_type(type); else field->filter_type = filter_type; field->offset = offset; field->size = size; field->is_signed = is_signed; list_add(&field->link, head); return 0; } int trace_define_field(struct trace_event_call *call, const char *type, const char *name, int offset, int size, int is_signed, int filter_type) { struct list_head *head; if (WARN_ON(!call->class)) return 0; head = trace_get_fields(call); return __trace_define_field(head, type, name, offset, size, is_signed, filter_type); } EXPORT_SYMBOL_GPL(trace_define_field); #define __generic_field(type, item, filter_type) \ ret = __trace_define_field(&ftrace_generic_fields, #type, \ #item, 0, 0, is_signed_type(type), \ filter_type); \ if (ret) \ return ret; #define __common_field(type, item) \ ret = __trace_define_field(&ftrace_common_fields, #type, \ "common_" #item, \ offsetof(typeof(ent), item), \ sizeof(ent.item), \ is_signed_type(type), FILTER_OTHER); \ if (ret) \ return ret; static int trace_define_generic_fields(void) { int ret; __generic_field(int, CPU, FILTER_CPU); __generic_field(int, cpu, FILTER_CPU); __generic_field(char *, COMM, FILTER_COMM); __generic_field(char *, comm, FILTER_COMM); return ret; } static int trace_define_common_fields(void) { int ret; struct trace_entry ent; __common_field(unsigned short, type); __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); return ret; } static void trace_destroy_fields(struct trace_event_call *call) { struct ftrace_event_field *field, *next; struct list_head *head; head = trace_get_fields(call); list_for_each_entry_safe(field, next, head, link) { list_del(&field->link); kmem_cache_free(field_cachep, field); } } /* * run-time version of trace_event_get_offsets_<call>() that returns the last * accessible offset of trace fields excluding __dynamic_array bytes */ int trace_event_get_offsets(struct trace_event_call *call) { struct ftrace_event_field *tail; struct list_head *head; head = trace_get_fields(call); /* * head->next points to the last field with the largest offset, * since it was added last by trace_define_field() */ tail = list_first_entry(head, struct ftrace_event_field, link); return tail->offset + tail->size; } int trace_event_raw_init(struct trace_event_call *call) { int id; id = register_trace_event(&call->event); if (!id) return -ENODEV; return 0; } EXPORT_SYMBOL_GPL(trace_event_raw_init); bool trace_event_ignore_this_pid(struct trace_event_file *trace_file) { struct trace_array *tr = trace_file->tr; struct trace_array_cpu *data; struct trace_pid_list *pid_list; pid_list = rcu_dereference_raw(tr->filtered_pids); if (!pid_list) return false; data = this_cpu_ptr(tr->trace_buffer.data); return data->ignore_pid; } EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid); void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, struct trace_event_file *trace_file, unsigned long len) { struct trace_event_call *event_call = trace_file->event_call; if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) && trace_event_ignore_this_pid(trace_file)) return NULL; local_save_flags(fbuffer->flags); fbuffer->pc = preempt_count(); /* * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables * preemption (adding one to the preempt_count). Since we are * interested in the preempt_count at the time the tracepoint was * hit, we need to subtract one to offset the increment. */ if (IS_ENABLED(CONFIG_PREEMPT)) fbuffer->pc--; fbuffer->trace_file = trace_file; fbuffer->event = trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file, event_call->event.type, len, fbuffer->flags, fbuffer->pc); if (!fbuffer->event) return NULL; fbuffer->entry = ring_buffer_event_data(fbuffer->event); return fbuffer->entry; } EXPORT_SYMBOL_GPL(trace_event_buffer_reserve); int trace_event_reg(struct trace_event_call *call, enum trace_reg type, void *data) { struct trace_event_file *file = data; WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT)); switch (type) { case TRACE_REG_REGISTER: return tracepoint_probe_register(call->tp, call->class->probe, file); case TRACE_REG_UNREGISTER: tracepoint_probe_unregister(call->tp, call->class->probe, file); return 0; #ifdef CONFIG_PERF_EVENTS case TRACE_REG_PERF_REGISTER: return tracepoint_probe_register(call->tp, call->class->perf_probe, call); case TRACE_REG_PERF_UNREGISTER: tracepoint_probe_unregister(call->tp, call->class->perf_probe, call); return 0; case TRACE_REG_PERF_OPEN: case TRACE_REG_PERF_CLOSE: case TRACE_REG_PERF_ADD: case TRACE_REG_PERF_DEL: return 0; #endif } return 0; } EXPORT_SYMBOL_GPL(trace_event_reg); void trace_event_enable_cmd_record(bool enable) { struct trace_event_file *file; struct trace_array *tr; mutex_lock(&event_mutex); do_for_each_event_file(tr, file) { if (!(file->flags & EVENT_FILE_FL_ENABLED)) continue; if (enable) { tracing_start_cmdline_record(); set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); } else { tracing_stop_cmdline_record(); clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); } } while_for_each_event_file(); mutex_unlock(&event_mutex); } void trace_event_enable_tgid_record(bool enable) { struct trace_event_file *file; struct trace_array *tr; mutex_lock(&event_mutex); do_for_each_event_file(tr, file) { if (!(file->flags & EVENT_FILE_FL_ENABLED)) continue; if (enable) { tracing_start_tgid_record(); set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); } else { tracing_stop_tgid_record(); clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); } } while_for_each_event_file(); mutex_unlock(&event_mutex); } static int __ftrace_event_enable_disable(struct trace_event_file *file, int enable, int soft_disable) { struct trace_event_call *call = file->event_call; struct trace_array *tr = file->tr; unsigned long file_flags = file->flags; int ret = 0; int disable; switch (enable) { case 0: /* * When soft_disable is set and enable is cleared, the sm_ref * reference counter is decremented. If it reaches 0, we want * to clear the SOFT_DISABLED flag but leave the event in the * state that it was. That is, if the event was enabled and * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED * is set we do not want the event to be enabled before we * clear the bit. * * When soft_disable is not set but the SOFT_MODE flag is, * we do nothing. Do not disable the tracepoint, otherwise * "soft enable"s (clearing the SOFT_DISABLED bit) wont work. */ if (soft_disable) { if (atomic_dec_return(&file->sm_ref) > 0) break; disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED; clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); } else disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE); if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) { clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); if (file->flags & EVENT_FILE_FL_RECORDED_CMD) { tracing_stop_cmdline_record(); clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); } if (file->flags & EVENT_FILE_FL_RECORDED_TGID) { tracing_stop_tgid_record(); clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); } call->class->reg(call, TRACE_REG_UNREGISTER, file); } /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */ if (file->flags & EVENT_FILE_FL_SOFT_MODE) set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); else clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); break; case 1: /* * When soft_disable is set and enable is set, we want to * register the tracepoint for the event, but leave the event * as is. That means, if the event was already enabled, we do * nothing (but set SOFT_MODE). If the event is disabled, we * set SOFT_DISABLED before enabling the event tracepoint, so * it still seems to be disabled. */ if (!soft_disable) clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); else { if (atomic_inc_return(&file->sm_ref) > 1) break; set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); } if (!(file->flags & EVENT_FILE_FL_ENABLED)) { bool cmd = false, tgid = false; /* Keep the event disabled, when going to SOFT_MODE. */ if (soft_disable) set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); if (tr->trace_flags & TRACE_ITER_RECORD_CMD) { cmd = true; tracing_start_cmdline_record(); set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); } if (tr->trace_flags & TRACE_ITER_RECORD_TGID) { tgid = true; tracing_start_tgid_record(); set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); } ret = call->class->reg(call, TRACE_REG_REGISTER, file); if (ret) { if (cmd) tracing_stop_cmdline_record(); if (tgid) tracing_stop_tgid_record(); pr_info("event trace: Could not enable event " "%s\n", trace_event_name(call)); break; } set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); /* WAS_ENABLED gets set but never cleared. */ set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags); } break; } /* Enable or disable use of trace_buffered_event */ if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) != (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) { if (file->flags & EVENT_FILE_FL_SOFT_DISABLED) trace_buffered_event_enable(); else trace_buffered_event_disable(); } return ret; } int trace_event_enable_disable(struct trace_event_file *file, int enable, int soft_disable) { return __ftrace_event_enable_disable(file, enable, soft_disable); } static int ftrace_event_enable_disable(struct trace_event_file *file, int enable) { return __ftrace_event_enable_disable(file, enable, 0); } static void ftrace_clear_events(struct trace_array *tr) { struct trace_event_file *file; mutex_lock(&event_mutex); list_for_each_entry(file, &tr->events, list) { ftrace_event_enable_disable(file, 0); } mutex_unlock(&event_mutex); } static void event_filter_pid_sched_process_exit(void *data, struct task_struct *task) { struct trace_pid_list *pid_list; struct trace_array *tr = data; pid_list = rcu_dereference_raw(tr->filtered_pids); trace_filter_add_remove_task(pid_list, NULL, task); } static void event_filter_pid_sched_process_fork(void *data, struct task_struct *self, struct task_struct *task) { struct trace_pid_list *pid_list; struct trace_array *tr = data; pid_list = rcu_dereference_sched(tr->filtered_pids); trace_filter_add_remove_task(pid_list, self, task); } void trace_event_follow_fork(struct trace_array *tr, bool enable) { if (enable) { register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork, tr, INT_MIN); register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit, tr, INT_MAX); } else { unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork, tr); unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit, tr); } } static void event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, struct task_struct *prev, struct task_struct *next) { struct trace_array *tr = data; struct trace_pid_list *pid_list; pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, trace_ignore_this_task(pid_list, prev) && trace_ignore_this_task(pid_list, next)); } static void event_filter_pid_sched_switch_probe_post(void *data, bool preempt, struct task_struct *prev, struct task_struct *next) { struct trace_array *tr = data; struct trace_pid_list *pid_list; pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, trace_ignore_this_task(pid_list, next)); } static void event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) { struct trace_array *tr = data; struct trace_pid_list *pid_list; /* Nothing to do if we are already tracing */ if (!this_cpu_read(tr->trace_buffer.data->ignore_pid)) return; pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, trace_ignore_this_task(pid_list, task)); } static void event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) { struct trace_array *tr = data; struct trace_pid_list *pid_list; /* Nothing to do if we are not tracing */ if (this_cpu_read(tr->trace_buffer.data->ignore_pid)) return; pid_list = rcu_dereference_sched(tr->filtered_pids); /* Set tracing if current is enabled */ this_cpu_write(tr->trace_buffer.data->ignore_pid, trace_ignore_this_task(pid_list, current)); } static void __ftrace_clear_event_pids(struct trace_array *tr) { struct trace_pid_list *pid_list; struct trace_event_file *file; int cpu; pid_list = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); if (!pid_list) return; unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr); unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr); unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr); unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr); unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr); unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr); unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr); unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr); list_for_each_entry(file, &tr->events, list) { clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); } for_each_possible_cpu(cpu) per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false; rcu_assign_pointer(tr->filtered_pids, NULL); /* Wait till all users are no longer using pid filtering */ tracepoint_synchronize_unregister(); trace_free_pid_list(pid_list); } static void ftrace_clear_event_pids(struct trace_array *tr) { mutex_lock(&event_mutex); __ftrace_clear_event_pids(tr); mutex_unlock(&event_mutex); } static void __put_system(struct event_subsystem *system) { struct event_filter *filter = system->filter; WARN_ON_ONCE(system_refcount(system) == 0); if (system_refcount_dec(system)) return; list_del(&system->list); if (filter) { kfree(filter->filter_string); kfree(filter); } kfree_const(system->name); kfree(system); } static void __get_system(struct event_subsystem *system) { WARN_ON_ONCE(system_refcount(system) == 0); system_refcount_inc(system); } static void __get_system_dir(struct trace_subsystem_dir *dir) { WARN_ON_ONCE(dir->ref_count == 0); dir->ref_count++; __get_system(dir->subsystem); } static void __put_system_dir(struct trace_subsystem_dir *dir) { WARN_ON_ONCE(dir->ref_count == 0); /* If the subsystem is about to be freed, the dir must be too */ WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1); __put_system(dir->subsystem); if (!--dir->ref_count) kfree(dir); } static void put_system(struct trace_subsystem_dir *dir) { mutex_lock(&event_mutex); __put_system_dir(dir); mutex_unlock(&event_mutex); } static void remove_subsystem(struct trace_subsystem_dir *dir) { if (!dir) return; if (!--dir->nr_events) { tracefs_remove_recursive(dir->entry); list_del(&dir->list); __put_system_dir(dir); } } static void remove_event_file_dir(struct trace_event_file *file) { struct dentry *dir = file->dir; struct dentry *child; if (dir) { spin_lock(&dir->d_lock); /* probably unneeded */ list_for_each_entry(child, &dir->d_subdirs, d_child) { if (d_really_is_positive(child)) /* probably unneeded */ d_inode(child)->i_private = NULL; } spin_unlock(&dir->d_lock); tracefs_remove_recursive(dir); } list_del(&file->list); remove_subsystem(file->system); free_event_filter(file->filter); kmem_cache_free(file_cachep, file); } /* * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. */ static int __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match, const char *sub, const char *event, int set) { struct trace_event_file *file; struct trace_event_call *call; const char *name; int ret = -EINVAL; int eret = 0; list_for_each_entry(file, &tr->events, list) { call = file->event_call; name = trace_event_name(call); if (!name || !call->class || !call->class->reg) continue; if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) continue; if (match && strcmp(match, name) != 0 && strcmp(match, call->class->system) != 0) continue; if (sub && strcmp(sub, call->class->system) != 0) continue; if (event && strcmp(event, name) != 0) continue; ret = ftrace_event_enable_disable(file, set); /* * Save the first error and return that. Some events * may still have been enabled, but let the user * know that something went wrong. */ if (ret && !eret) eret = ret; ret = eret; } return ret; } static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, const char *sub, const char *event, int set) { int ret; mutex_lock(&event_mutex); ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set); mutex_unlock(&event_mutex); return ret; } static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) { char *event = NULL, *sub = NULL, *match; int ret; /* * The buf format can be <subsystem>:<event-name> * *:<event-name> means any event by that name. * :<event-name> is the same. * * <subsystem>:* means all events in that subsystem * <subsystem>: means the same. * * <name> (no ':') means all events in a subsystem with * the name <name> or any event that matches <name> */ match = strsep(&buf, ":"); if (buf) { sub = match; event = buf; match = NULL; if (!strlen(sub) || strcmp(sub, "*") == 0) sub = NULL; if (!strlen(event) || strcmp(event, "*") == 0) event = NULL; } ret = __ftrace_set_clr_event(tr, match, sub, event, set); /* Put back the colon to allow this to be called again */ if (buf) *(buf - 1) = ':'; return ret; } /** * trace_set_clr_event - enable or disable an event * @system: system name to match (NULL for any system) * @event: event name to match (NULL for all events, within system) * @set: 1 to enable, 0 to disable * * This is a way for other parts of the kernel to enable or disable * event recording. * * Returns 0 on success, -EINVAL if the parameters do not match any * registered events. */ int trace_set_clr_event(const char *system, const char *event, int set) { struct trace_array *tr = top_trace_array(); if (!tr) return -ENODEV; return __ftrace_set_clr_event(tr, NULL, system, event, set); } EXPORT_SYMBOL_GPL(trace_set_clr_event); /* 128 should be much more than enough */ #define EVENT_BUF_SIZE 127 static ssize_t ftrace_event_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; struct seq_file *m = file->private_data; struct trace_array *tr = m->private; ssize_t read, ret; if (!cnt) return 0; ret = tracing_update_buffers(); if (ret < 0) return ret; if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) return -ENOMEM; read = trace_get_user(&parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded((&parser))) { int set = 1; if (*parser.buffer == '!') set = 0; ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); if (ret) goto out_put; } ret = read; out_put: trace_parser_put(&parser); return ret; } static void * t_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_event_file *file = v; struct trace_event_call *call; struct trace_array *tr = m->private; (*pos)++; list_for_each_entry_continue(file, &tr->events, list) { call = file->event_call; /* * The ftrace subsystem is for showing formats only. * They can not be enabled or disabled via the event files. */ if (call->class && call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) return file; } return NULL; } static void *t_start(struct seq_file *m, loff_t *pos) { struct trace_event_file *file; struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); file = list_entry(&tr->events, struct trace_event_file, list); for (l = 0; l <= *pos; ) { file = t_next(m, file, &l); if (!file) break; } return file; } static void * s_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_event_file *file = v; struct trace_array *tr = m->private; (*pos)++; list_for_each_entry_continue(file, &tr->events, list) { if (file->flags & EVENT_FILE_FL_ENABLED) return file; } return NULL; } static void *s_start(struct seq_file *m, loff_t *pos) { struct trace_event_file *file; struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); file = list_entry(&tr->events, struct trace_event_file, list); for (l = 0; l <= *pos; ) { file = s_next(m, file, &l); if (!file) break; } return file; } static int t_show(struct seq_file *m, void *v) { struct trace_event_file *file = v; struct trace_event_call *call = file->event_call; if (strcmp(call->class->system, TRACE_SYSTEM) != 0) seq_printf(m, "%s:", call->class->system); seq_printf(m, "%s\n", trace_event_name(call)); return 0; } static void t_stop(struct seq_file *m, void *p) { mutex_unlock(&event_mutex); } static void * p_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_array *tr = m->private; struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); return trace_pid_next(pid_list, v, pos); } static void *p_start(struct seq_file *m, loff_t *pos) __acquires(RCU) { struct trace_pid_list *pid_list; struct trace_array *tr = m->private; /* * Grab the mutex, to keep calls to p_next() having the same * tr->filtered_pids as p_start() has. * If we just passed the tr->filtered_pids around, then RCU would * have been enough, but doing that makes things more complex. */ mutex_lock(&event_mutex); rcu_read_lock_sched(); pid_list = rcu_dereference_sched(tr->filtered_pids); if (!pid_list) return NULL; return trace_pid_start(pid_list, pos); } static void p_stop(struct seq_file *m, void *p) __releases(RCU) { rcu_read_unlock_sched(); mutex_unlock(&event_mutex); } static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_event_file *file; unsigned long flags; char buf[4] = "0"; mutex_lock(&event_mutex); file = event_file_data(filp); if (likely(file)) flags = file->flags; mutex_unlock(&event_mutex); if (!file) return -ENODEV; if (flags & EVENT_FILE_FL_ENABLED && !(flags & EVENT_FILE_FL_SOFT_DISABLED)) strcpy(buf, "1"); if (flags & EVENT_FILE_FL_SOFT_DISABLED || flags & EVENT_FILE_FL_SOFT_MODE) strcat(buf, "*"); strcat(buf, "\n"); return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf)); } static ssize_t event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_event_file *file; unsigned long val; int ret; ret = kstrtoul_from_user(ubuf, cnt, 10, &val); if (ret) return ret; ret = tracing_update_buffers(); if (ret < 0) return ret; switch (val) { case 0: case 1: ret = -ENODEV; mutex_lock(&event_mutex); file = event_file_data(filp); if (likely(file)) ret = ftrace_event_enable_disable(file, val); mutex_unlock(&event_mutex); break; default: return -EINVAL; } *ppos += cnt; return ret ? ret : cnt; } static ssize_t system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { const char set_to_char[4] = { '?', '0', '1', 'X' }; struct trace_subsystem_dir *dir = filp->private_data; struct event_subsystem *system = dir->subsystem; struct trace_event_call *call; struct trace_event_file *file; struct trace_array *tr = dir->tr; char buf[2]; int set = 0; int ret; mutex_lock(&event_mutex); list_for_each_entry(file, &tr->events, list) { call = file->event_call; if (!trace_event_name(call) || !call->class || !call->class->reg) continue; if (system && strcmp(call->class->system, system->name) != 0) continue; /* * We need to find out if all the events are set * or if all events or cleared, or if we have * a mixture. */ set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED)); /* * If we have a mixture, no need to look further. */ if (set == 3) break; } mutex_unlock(&event_mutex); buf[0] = set_to_char[set]; buf[1] = '\n'; ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); return ret; } static ssize_t system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_subsystem_dir *dir = filp->private_data; struct event_subsystem *system = dir->subsystem; const char *name = NULL; unsigned long val; ssize_t ret; ret = kstrtoul_from_user(ubuf, cnt, 10, &val); if (ret) return ret; ret = tracing_update_buffers(); if (ret < 0) return ret; if (val != 0 && val != 1) return -EINVAL; /* * Opening of "enable" adds a ref count to system, * so the name is safe to use. */ if (system) name = system->name; ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val); if (ret) goto out; ret = cnt; out: *ppos += cnt; return ret; } enum { FORMAT_HEADER = 1, FORMAT_FIELD_SEPERATOR = 2, FORMAT_PRINTFMT = 3, }; static void *f_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_event_call *call = event_file_data(m->private); struct list_head *common_head = &ftrace_common_fields; struct list_head *head = trace_get_fields(call); struct list_head *node = v; (*pos)++; switch ((unsigned long)v) { case FORMAT_HEADER: node = common_head; break; case FORMAT_FIELD_SEPERATOR: node = head; break; case FORMAT_PRINTFMT: /* all done */ return NULL; } node = node->prev; if (node == common_head) return (void *)FORMAT_FIELD_SEPERATOR; else if (node == head) return (void *)FORMAT_PRINTFMT; else return node; } static int f_show(struct seq_file *m, void *v) { struct trace_event_call *call = event_file_data(m->private); struct ftrace_event_field *field; const char *array_descriptor; switch ((unsigned long)v) { case FORMAT_HEADER: seq_printf(m, "name: %s\n", trace_event_name(call)); seq_printf(m, "ID: %d\n", call->event.type); seq_puts(m, "format:\n"); return 0; case FORMAT_FIELD_SEPERATOR: seq_putc(m, '\n'); return 0; case FORMAT_PRINTFMT: seq_printf(m, "\nprint fmt: %s\n", call->print_fmt); return 0; } field = list_entry(v, struct ftrace_event_field, link); /* * Smartly shows the array type(except dynamic array). * Normal: * field:TYPE VAR * If TYPE := TYPE[LEN], it is shown: * field:TYPE VAR[LEN] */ array_descriptor = strchr(field->type, '['); if (str_has_prefix(field->type, "__data_loc")) array_descriptor = NULL; if (!array_descriptor) seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", field->type, field->name, field->offset, field->size, !!field->is_signed); else seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", (int)(array_descriptor - field->type), field->type, field->name, array_descriptor, field->offset, field->size, !!field->is_signed); return 0; } static void *f_start(struct seq_file *m, loff_t *pos) { void *p = (void *)FORMAT_HEADER; loff_t l = 0; /* ->stop() is called even if ->start() fails */ mutex_lock(&event_mutex); if (!event_file_data(m->private)) return ERR_PTR(-ENODEV); while (l < *pos && p) p = f_next(m, p, &l); return p; } static void f_stop(struct seq_file *m, void *p) { mutex_unlock(&event_mutex); } static const struct seq_operations trace_format_seq_ops = { .start = f_start, .next = f_next, .stop = f_stop, .show = f_show, }; static int trace_format_open(struct inode *inode, struct file *file) { struct seq_file *m; int ret; ret = seq_open(file, &trace_format_seq_ops); if (ret < 0) return ret; m = file->private_data; m->private = file; return 0; } static ssize_t event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { int id = (long)event_file_data(filp); char buf[32]; int len; if (*ppos) return 0; if (unlikely(!id)) return -ENODEV; len = sprintf(buf, "%d\n", id); return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); } static ssize_t event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_event_file *file; struct trace_seq *s; int r = -ENODEV; if (*ppos) return 0; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) return -ENOMEM; trace_seq_init(s); mutex_lock(&event_mutex); file = event_file_data(filp); if (file) print_event_filter(file, s); mutex_unlock(&event_mutex); if (file) r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); kfree(s); return r; } static ssize_t event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_event_file *file; char *buf; int err = -ENODEV; if (cnt >= PAGE_SIZE) return -EINVAL; buf = memdup_user_nul(ubuf, cnt); if (IS_ERR(buf)) return PTR_ERR(buf); mutex_lock(&event_mutex); file = event_file_data(filp); if (file) err = apply_event_filter(file, buf); mutex_unlock(&event_mutex); kfree(buf); if (err < 0) return err; *ppos += cnt; return cnt; } static LIST_HEAD(event_subsystems); static int subsystem_open(struct inode *inode, struct file *filp) { struct event_subsystem *system = NULL; struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */ struct trace_array *tr; int ret; if (tracing_is_disabled()) return -ENODEV; /* Make sure the system still exists */ mutex_lock(&event_mutex); mutex_lock(&trace_types_lock); list_for_each_entry(tr, &ftrace_trace_arrays, list) { list_for_each_entry(dir, &tr->systems, list) { if (dir == inode->i_private) { /* Don't open systems with no events */ if (dir->nr_events) { __get_system_dir(dir); system = dir->subsystem; } goto exit_loop; } } } exit_loop: mutex_unlock(&trace_types_lock); mutex_unlock(&event_mutex); if (!system) return -ENODEV; /* Some versions of gcc think dir can be uninitialized here */ WARN_ON(!dir); /* Still need to increment the ref count of the system */ if (trace_array_get(tr) < 0) { put_system(dir); return -ENODEV; } ret = tracing_open_generic(inode, filp); if (ret < 0) { trace_array_put(tr); put_system(dir); } return ret; } static int system_tr_open(struct inode *inode, struct file *filp) { struct trace_subsystem_dir *dir; struct trace_array *tr = inode->i_private; int ret; if (tracing_is_disabled()) return -ENODEV; if (trace_array_get(tr) < 0) return -ENODEV; /* Make a temporary dir that has no system but points to tr */ dir = kzalloc(sizeof(*dir), GFP_KERNEL); if (!dir) { trace_array_put(tr); return -ENOMEM; } dir->tr = tr; ret = tracing_open_generic(inode, filp); if (ret < 0) { trace_array_put(tr); kfree(dir); return ret; } filp->private_data = dir; return 0; } static int subsystem_release(struct inode *inode, struct file *file) { struct trace_subsystem_dir *dir = file->private_data; trace_array_put(dir->tr); /* * If dir->subsystem is NULL, then this is a temporary * descriptor that was made for a trace_array to enable * all subsystems. */ if (dir->subsystem) put_system(dir); else kfree(dir); return 0; } static ssize_t subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_subsystem_dir *dir = filp->private_data; struct event_subsystem *system = dir->subsystem; struct trace_seq *s; int r; if (*ppos) return 0; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) return -ENOMEM; trace_seq_init(s); print_subsystem_event_filter(system, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); kfree(s); return r; } static ssize_t subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_subsystem_dir *dir = filp->private_data; char *buf; int err; if (cnt >= PAGE_SIZE) return -EINVAL; buf = memdup_user_nul(ubuf, cnt); if (IS_ERR(buf)) return PTR_ERR(buf); err = apply_subsystem_event_filter(dir, buf); kfree(buf); if (err < 0) return err; *ppos += cnt; return cnt; } static ssize_t show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { int (*func)(struct trace_seq *s) = filp->private_data; struct trace_seq *s; int r; if (*ppos) return 0; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) return -ENOMEM; trace_seq_init(s); func(s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); kfree(s); return r; } static void ignore_task_cpu(void *data) { struct trace_array *tr = data; struct trace_pid_list *pid_list; /* * This function is called by on_each_cpu() while the * event_mutex is held. */ pid_list = rcu_dereference_protected(tr->filtered_pids, mutex_is_locked(&event_mutex)); this_cpu_write(tr->trace_buffer.data->ignore_pid, trace_ignore_this_task(pid_list, current)); } static ssize_t ftrace_event_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct seq_file *m = filp->private_data; struct trace_array *tr = m->private; struct trace_pid_list *filtered_pids = NULL; struct trace_pid_list *pid_list; struct trace_event_file *file; ssize_t ret; if (!cnt) return 0; ret = tracing_update_buffers(); if (ret < 0) return ret; mutex_lock(&event_mutex); filtered_pids = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); if (ret < 0) goto out; rcu_assign_pointer(tr->filtered_pids, pid_list); list_for_each_entry(file, &tr->events, list) { set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); } if (filtered_pids) { tracepoint_synchronize_unregister(); trace_free_pid_list(filtered_pids); } else if (pid_list) { /* * Register a probe that is called before all other probes * to set ignore_pid if next or prev do not match. * Register a probe this is called after all other probes * to only keep ignore_pid set if next pid matches. */ register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre, tr, INT_MAX); register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post, tr, 0); register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr, INT_MAX); register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr, 0); register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr, INT_MAX); register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr, 0); register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr, INT_MAX); register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr, 0); } /* * Ignoring of pids is done at task switch. But we have to * check for those tasks that are currently running. * Always do this in case a pid was appended or removed. */ on_each_cpu(ignore_task_cpu, tr, 1); out: mutex_unlock(&event_mutex); if (ret > 0) *ppos += ret; return ret; } static int ftrace_event_avail_open(struct inode *inode, struct file *file); static int ftrace_event_set_open(struct inode *inode, struct file *file); static int ftrace_event_set_pid_open(struct inode *inode, struct file *file); static int ftrace_event_release(struct inode *inode, struct file *file); static const struct seq_operations show_event_seq_ops = { .start = t_start, .next = t_next, .show = t_show, .stop = t_stop, }; static const struct seq_operations show_set_event_seq_ops = { .start = s_start, .next = s_next, .show = t_show, .stop = t_stop, }; static const struct seq_operations show_set_pid_seq_ops = { .start = p_start, .next = p_next, .show = trace_pid_show, .stop = p_stop, }; static const struct file_operations ftrace_avail_fops = { .open = ftrace_event_avail_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; static const struct file_operations ftrace_set_event_fops = { .open = ftrace_event_set_open, .read = seq_read, .write = ftrace_event_write, .llseek = seq_lseek, .release = ftrace_event_release, }; static const struct file_operations ftrace_set_event_pid_fops = { .open = ftrace_event_set_pid_open, .read = seq_read, .write = ftrace_event_pid_write, .llseek = seq_lseek, .release = ftrace_event_release, }; static const struct file_operations ftrace_enable_fops = { .open = tracing_open_generic, .read = event_enable_read, .write = event_enable_write, .llseek = default_llseek, }; static const struct file_operations ftrace_event_format_fops = { .open = trace_format_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; static const struct file_operations ftrace_event_id_fops = { .read = event_id_read, .llseek = default_llseek, }; static const struct file_operations ftrace_event_filter_fops = { .open = tracing_open_generic, .read = event_filter_read, .write = event_filter_write, .llseek = default_llseek, }; static const struct file_operations ftrace_subsystem_filter_fops = { .open = subsystem_open, .read = subsystem_filter_read, .write = subsystem_filter_write, .llseek = default_llseek, .release = subsystem_release, }; static const struct file_operations ftrace_system_enable_fops = { .open = subsystem_open, .read = system_enable_read, .write = system_enable_write, .llseek = default_llseek, .release = subsystem_release, }; static const struct file_operations ftrace_tr_enable_fops = { .open = system_tr_open, .read = system_enable_read, .write = system_enable_write, .llseek = default_llseek, .release = subsystem_release, }; static const struct file_operations ftrace_show_header_fops = { .open = tracing_open_generic, .read = show_header, .llseek = default_llseek, }; static int ftrace_event_open(struct inode *inode, struct file *file, const struct seq_operations *seq_ops) { struct seq_file *m; int ret; ret = seq_open(file, seq_ops); if (ret < 0) return ret; m = file->private_data; /* copy tr over to seq ops */ m->private = inode->i_private; return ret; } static int ftrace_event_release(struct inode *inode, struct file *file) { struct trace_array *tr = inode->i_private; trace_array_put(tr); return seq_release(inode, file); } static int ftrace_event_avail_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_event_seq_ops; return ftrace_event_open(inode, file, seq_ops); } static int ftrace_event_set_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_set_event_seq_ops; struct trace_array *tr = inode->i_private; int ret; if (trace_array_get(tr) < 0) return -ENODEV; if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) ftrace_clear_events(tr); ret = ftrace_event_open(inode, file, seq_ops); if (ret < 0) trace_array_put(tr); return ret; } static int ftrace_event_set_pid_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_set_pid_seq_ops; struct trace_array *tr = inode->i_private; int ret; if (trace_array_get(tr) < 0) return -ENODEV; if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) ftrace_clear_event_pids(tr); ret = ftrace_event_open(inode, file, seq_ops); if (ret < 0) trace_array_put(tr); return ret; } static struct event_subsystem * create_new_subsystem(const char *name) { struct event_subsystem *system; /* need to create new entry */ system = kmalloc(sizeof(*system), GFP_KERNEL); if (!system) return NULL; system->ref_count = 1; /* Only allocate if dynamic (kprobes and modules) */ system->name = kstrdup_const(name, GFP_KERNEL); if (!system->name) goto out_free; system->filter = NULL; system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); if (!system->filter) goto out_free; list_add(&system->list, &event_subsystems); return system; out_free: kfree_const(system->name); kfree(system); return NULL; } static struct dentry * event_subsystem_dir(struct trace_array *tr, const char *name, struct trace_event_file *file, struct dentry *parent) { struct trace_subsystem_dir *dir; struct event_subsystem *system; struct dentry *entry; /* First see if we did not already create this dir */ list_for_each_entry(dir, &tr->systems, list) { system = dir->subsystem; if (strcmp(system->name, name) == 0) { dir->nr_events++; file->system = dir; return dir->entry; } } /* Now see if the system itself exists. */ list_for_each_entry(system, &event_subsystems, list) { if (strcmp(system->name, name) == 0) break; } /* Reset system variable when not found */ if (&system->list == &event_subsystems) system = NULL; dir = kmalloc(sizeof(*dir), GFP_KERNEL); if (!dir) goto out_fail; if (!system) { system = create_new_subsystem(name); if (!system) goto out_free; } else __get_system(system); dir->entry = tracefs_create_dir(name, parent); if (!dir->entry) { pr_warn("Failed to create system directory %s\n", name); __put_system(system); goto out_free; } dir->tr = tr; dir->ref_count = 1; dir->nr_events = 1; dir->subsystem = system; file->system = dir; entry = tracefs_create_file("filter", 0644, dir->entry, dir, &ftrace_subsystem_filter_fops); if (!entry) { kfree(system->filter); system->filter = NULL; pr_warn("Could not create tracefs '%s/filter' entry\n", name); } trace_create_file("enable", 0644, dir->entry, dir, &ftrace_system_enable_fops); list_add(&dir->list, &tr->systems); return dir->entry; out_free: kfree(dir); out_fail: /* Only print this message if failed on memory allocation */ if (!dir || !system) pr_warn("No memory to create event subsystem %s\n", name); return NULL; } static int event_create_dir(struct dentry *parent, struct trace_event_file *file) { struct trace_event_call *call = file->event_call; struct trace_array *tr = file->tr; struct list_head *head; struct dentry *d_events; const char *name; int ret; /* * If the trace point header did not define TRACE_SYSTEM * then the system would be called "TRACE_SYSTEM". */ if (strcmp(call->class->system, TRACE_SYSTEM) != 0) { d_events = event_subsystem_dir(tr, call->class->system, file, parent); if (!d_events) return -ENOMEM; } else d_events = parent; name = trace_event_name(call); file->dir = tracefs_create_dir(name, d_events); if (!file->dir) { pr_warn("Could not create tracefs '%s' directory\n", name); return -1; } if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) trace_create_file("enable", 0644, file->dir, file, &ftrace_enable_fops); #ifdef CONFIG_PERF_EVENTS if (call->event.type && call->class->reg) trace_create_file("id", 0444, file->dir, (void *)(long)call->event.type, &ftrace_event_id_fops); #endif /* * Other events may have the same class. Only update * the fields if they are not already defined. */ head = trace_get_fields(call); if (list_empty(head)) { ret = call->class->define_fields(call); if (ret < 0) { pr_warn("Could not initialize trace point events/%s\n", name); return -1; } } /* * Only event directories that can be enabled should have * triggers or filters. */ if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) { trace_create_file("filter", 0644, file->dir, file, &ftrace_event_filter_fops); trace_create_file("trigger", 0644, file->dir, file, &event_trigger_fops); } #ifdef CONFIG_HIST_TRIGGERS trace_create_file("hist", 0444, file->dir, file, &event_hist_fops); #endif trace_create_file("format", 0444, file->dir, call, &ftrace_event_format_fops); return 0; } static void remove_event_from_tracers(struct trace_event_call *call) { struct trace_event_file *file; struct trace_array *tr; do_for_each_event_file_safe(tr, file) { if (file->event_call != call) continue; remove_event_file_dir(file); /* * The do_for_each_event_file_safe() is * a double loop. After finding the call for this * trace_array, we use break to jump to the next * trace_array. */ break; } while_for_each_event_file(); } static void event_remove(struct trace_event_call *call) { struct trace_array *tr; struct trace_event_file *file; do_for_each_event_file(tr, file) { if (file->event_call != call) continue; if (file->flags & EVENT_FILE_FL_WAS_ENABLED) tr->clear_trace = true; ftrace_event_enable_disable(file, 0); /* * The do_for_each_event_file() is * a double loop. After finding the call for this * trace_array, we use break to jump to the next * trace_array. */ break; } while_for_each_event_file(); if (call->event.funcs) __unregister_trace_event(&call->event); remove_event_from_tracers(call); list_del(&call->list); } static int event_init(struct trace_event_call *call) { int ret = 0; const char *name; name = trace_event_name(call); if (WARN_ON(!name)) return -EINVAL; if (call->class->raw_init) { ret = call->class->raw_init(call); if (ret < 0 && ret != -ENOSYS) pr_warn("Could not initialize trace events/%s\n", name); } return ret; } static int __register_event(struct trace_event_call *call, struct module *mod) { int ret; ret = event_init(call); if (ret < 0) return ret; list_add(&call->list, &ftrace_events); call->mod = mod; return 0; } static char *eval_replace(char *ptr, struct trace_eval_map *map, int len) { int rlen; int elen; /* Find the length of the eval value as a string */ elen = snprintf(ptr, 0, "%ld", map->eval_value); /* Make sure there's enough room to replace the string with the value */ if (len < elen) return NULL; snprintf(ptr, elen + 1, "%ld", map->eval_value); /* Get the rest of the string of ptr */ rlen = strlen(ptr + len); memmove(ptr + elen, ptr + len, rlen); /* Make sure we end the new string */ ptr[elen + rlen] = 0; return ptr + elen; } static void update_event_printk(struct trace_event_call *call, struct trace_eval_map *map) { char *ptr; int quote = 0; int len = strlen(map->eval_string); for (ptr = call->print_fmt; *ptr; ptr++) { if (*ptr == '\\') { ptr++; /* paranoid */ if (!*ptr) break; continue; } if (*ptr == '"') { quote ^= 1; continue; } if (quote) continue; if (isdigit(*ptr)) { /* skip numbers */ do { ptr++; /* Check for alpha chars like ULL */ } while (isalnum(*ptr)); if (!*ptr) break; /* * A number must have some kind of delimiter after * it, and we can ignore that too. */ continue; } if (isalpha(*ptr) || *ptr == '_') { if (strncmp(map->eval_string, ptr, len) == 0 && !isalnum(ptr[len]) && ptr[len] != '_') { ptr = eval_replace(ptr, map, len); /* enum/sizeof string smaller than value */ if (WARN_ON_ONCE(!ptr)) return; /* * No need to decrement here, as eval_replace() * returns the pointer to the character passed * the eval, and two evals can not be placed * back to back without something in between. * We can skip that something in between. */ continue; } skip_more: do { ptr++; } while (isalnum(*ptr) || *ptr == '_'); if (!*ptr) break; /* * If what comes after this variable is a '.' or * '->' then we can continue to ignore that string. */ if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) { ptr += *ptr == '.' ? 1 : 2; if (!*ptr) break; goto skip_more; } /* * Once again, we can skip the delimiter that came * after the string. */ continue; } } } void trace_event_eval_update(struct trace_eval_map **map, int len) { struct trace_event_call *call, *p; const char *last_system = NULL; bool first = false; int last_i; int i; down_write(&trace_event_sem); list_for_each_entry_safe(call, p, &ftrace_events, list) { /* events are usually grouped together with systems */ if (!last_system || call->class->system != last_system) { first = true; last_i = 0; last_system = call->class->system; } /* * Since calls are grouped by systems, the likelyhood that the * next call in the iteration belongs to the same system as the * previous call is high. As an optimization, we skip seaching * for a map[] that matches the call's system if the last call * was from the same system. That's what last_i is for. If the * call has the same system as the previous call, then last_i * will be the index of the first map[] that has a matching * system. */ for (i = last_i; i < len; i++) { if (call->class->system == map[i]->system) { /* Save the first system if need be */ if (first) { last_i = i; first = false; } update_event_printk(call, map[i]); } } } up_write(&trace_event_sem); } static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) { struct trace_event_file *file; file = kmem_cache_alloc(file_cachep, GFP_TRACE); if (!file) return NULL; file->event_call = call; file->tr = tr; atomic_set(&file->sm_ref, 0); atomic_set(&file->tm_ref, 0); INIT_LIST_HEAD(&file->triggers); list_add(&file->list, &tr->events); return file; } /* Add an event to a trace directory */ static int __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr) { struct trace_event_file *file; file = trace_create_new_event(call, tr); if (!file) return -ENOMEM; return event_create_dir(tr->event_dir, file); } /* * Just create a decriptor for early init. A descriptor is required * for enabling events at boot. We want to enable events before * the filesystem is initialized. */ static __init int __trace_early_add_new_event(struct trace_event_call *call, struct trace_array *tr) { struct trace_event_file *file; file = trace_create_new_event(call, tr); if (!file) return -ENOMEM; return 0; } struct ftrace_module_file_ops; static void __add_event_to_tracers(struct trace_event_call *call); /* Add an additional event_call dynamically */ int trace_add_event_call(struct trace_event_call *call) { int ret; lockdep_assert_held(&event_mutex); mutex_lock(&trace_types_lock); ret = __register_event(call, NULL); if (ret >= 0) __add_event_to_tracers(call); mutex_unlock(&trace_types_lock); return ret; } /* * Must be called under locking of trace_types_lock, event_mutex and * trace_event_sem. */ static void __trace_remove_event_call(struct trace_event_call *call) { event_remove(call); trace_destroy_fields(call); free_event_filter(call->filter); call->filter = NULL; } static int probe_remove_event_call(struct trace_event_call *call) { struct trace_array *tr; struct trace_event_file *file; #ifdef CONFIG_PERF_EVENTS if (call->perf_refcount) return -EBUSY; #endif do_for_each_event_file(tr, file) { if (file->event_call != call) continue; /* * We can't rely on ftrace_event_enable_disable(enable => 0) * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress * TRACE_REG_UNREGISTER. */ if (file->flags & EVENT_FILE_FL_ENABLED) return -EBUSY; /* * The do_for_each_event_file_safe() is * a double loop. After finding the call for this * trace_array, we use break to jump to the next * trace_array. */ break; } while_for_each_event_file(); __trace_remove_event_call(call); return 0; } /* Remove an event_call */ int trace_remove_event_call(struct trace_event_call *call) { int ret; lockdep_assert_held(&event_mutex); mutex_lock(&trace_types_lock); down_write(&trace_event_sem); ret = probe_remove_event_call(call); up_write(&trace_event_sem); mutex_unlock(&trace_types_lock); return ret; } #define for_each_event(event, start, end) \ for (event = start; \ (unsigned long)event < (unsigned long)end; \ event++) #ifdef CONFIG_MODULES static void trace_module_add_events(struct module *mod) { struct trace_event_call **call, **start, **end; if (!mod->num_trace_events) return; /* Don't add infrastructure for mods without tracepoints */ if (trace_module_has_bad_taint(mod)) { pr_err("%s: module has bad taint, not creating trace events\n", mod->name); return; } start = mod->trace_events; end = mod->trace_events + mod->num_trace_events; for_each_event(call, start, end) { __register_event(*call, mod); __add_event_to_tracers(*call); } } static void trace_module_remove_events(struct module *mod) { struct trace_event_call *call, *p; down_write(&trace_event_sem); list_for_each_entry_safe(call, p, &ftrace_events, list) { if (call->mod == mod) __trace_remove_event_call(call); } up_write(&trace_event_sem); /* * It is safest to reset the ring buffer if the module being unloaded * registered any events that were used. The only worry is if * a new module gets loaded, and takes on the same id as the events * of this module. When printing out the buffer, traced events left * over from this module may be passed to the new module events and * unexpected results may occur. */ tracing_reset_all_online_cpus(); } static int trace_module_notify(struct notifier_block *self, unsigned long val, void *data) { struct module *mod = data; mutex_lock(&event_mutex); mutex_lock(&trace_types_lock); switch (val) { case MODULE_STATE_COMING: trace_module_add_events(mod); break; case MODULE_STATE_GOING: trace_module_remove_events(mod); break; } mutex_unlock(&trace_types_lock); mutex_unlock(&event_mutex); return 0; } static struct notifier_block trace_module_nb = { .notifier_call = trace_module_notify, .priority = 1, /* higher than trace.c module notify */ }; #endif /* CONFIG_MODULES */ /* Create a new event directory structure for a trace directory. */ static void __trace_add_event_dirs(struct trace_array *tr) { struct trace_event_call *call; int ret; list_for_each_entry(call, &ftrace_events, list) { ret = __trace_add_new_event(call, tr); if (ret < 0) pr_warn("Could not create directory for event %s\n", trace_event_name(call)); } } /* Returns any file that matches the system and event */ struct trace_event_file * __find_event_file(struct trace_array *tr, const char *system, const char *event) { struct trace_event_file *file; struct trace_event_call *call; const char *name; list_for_each_entry(file, &tr->events, list) { call = file->event_call; name = trace_event_name(call); if (!name || !call->class) continue; if (strcmp(event, name) == 0 && strcmp(system, call->class->system) == 0) return file; } return NULL; } /* Returns valid trace event files that match system and event */ struct trace_event_file * find_event_file(struct trace_array *tr, const char *system, const char *event) { struct trace_event_file *file; file = __find_event_file(tr, system, event); if (!file || !file->event_call->class->reg || file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) return NULL; return file; } #ifdef CONFIG_DYNAMIC_FTRACE /* Avoid typos */ #define ENABLE_EVENT_STR "enable_event" #define DISABLE_EVENT_STR "disable_event" struct event_probe_data { struct trace_event_file *file; unsigned long count; int ref; bool enable; }; static void update_event_probe(struct event_probe_data *data) { if (data->enable) clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); else set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); } static void event_enable_probe(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_mapper *mapper = data; struct event_probe_data *edata; void **pdata; pdata = ftrace_func_mapper_find_ip(mapper, ip); if (!pdata || !*pdata) return; edata = *pdata; update_event_probe(edata); } static void event_enable_count_probe(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_mapper *mapper = data; struct event_probe_data *edata; void **pdata; pdata = ftrace_func_mapper_find_ip(mapper, ip); if (!pdata || !*pdata) return; edata = *pdata; if (!edata->count) return; /* Skip if the event is in a state we want to switch to */ if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) return; if (edata->count != -1) (edata->count)--; update_event_probe(edata); } static int event_enable_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_mapper *mapper = data; struct event_probe_data *edata; void **pdata; pdata = ftrace_func_mapper_find_ip(mapper, ip); if (WARN_ON_ONCE(!pdata || !*pdata)) return 0; edata = *pdata; seq_printf(m, "%ps:", (void *)ip); seq_printf(m, "%s:%s:%s", edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, edata->file->event_call->class->system, trace_event_name(edata->file->event_call)); if (edata->count == -1) seq_puts(m, ":unlimited\n"); else seq_printf(m, ":count=%ld\n", edata->count); return 0; } static int event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr, unsigned long ip, void *init_data, void **data) { struct ftrace_func_mapper *mapper = *data; struct event_probe_data *edata = init_data; int ret; if (!mapper) { mapper = allocate_ftrace_func_mapper(); if (!mapper) return -ENODEV; *data = mapper; } ret = ftrace_func_mapper_add_ip(mapper, ip, edata); if (ret < 0) return ret; edata->ref++; return 0; } static int free_probe_data(void *data) { struct event_probe_data *edata = data; edata->ref--; if (!edata->ref) { /* Remove the SOFT_MODE flag */ __ftrace_event_enable_disable(edata->file, 0, 1); module_put(edata->file->event_call->mod); kfree(edata); } return 0; } static void event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr, unsigned long ip, void *data) { struct ftrace_func_mapper *mapper = data; struct event_probe_data *edata; if (!ip) { if (!mapper) return; free_ftrace_func_mapper(mapper, free_probe_data); return; } edata = ftrace_func_mapper_remove_ip(mapper, ip); if (WARN_ON_ONCE(!edata)) return; if (WARN_ON_ONCE(edata->ref <= 0)) return; free_probe_data(edata); } static struct ftrace_probe_ops event_enable_probe_ops = { .func = event_enable_probe, .print = event_enable_print, .init = event_enable_init, .free = event_enable_free, }; static struct ftrace_probe_ops event_enable_count_probe_ops = { .func = event_enable_count_probe, .print = event_enable_print, .init = event_enable_init, .free = event_enable_free, }; static struct ftrace_probe_ops event_disable_probe_ops = { .func = event_enable_probe, .print = event_enable_print, .init = event_enable_init, .free = event_enable_free, }; static struct ftrace_probe_ops event_disable_count_probe_ops = { .func = event_enable_count_probe, .print = event_enable_print, .init = event_enable_init, .free = event_enable_free, }; static int event_enable_func(struct trace_array *tr, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enabled) { struct trace_event_file *file; struct ftrace_probe_ops *ops; struct event_probe_data *data; const char *system; const char *event; char *number; bool enable; int ret; if (!tr) return -ENODEV; /* hash funcs only work with set_ftrace_filter */ if (!enabled || !param) return -EINVAL; system = strsep(¶m, ":"); if (!param) return -EINVAL; event = strsep(¶m, ":"); mutex_lock(&event_mutex); ret = -EINVAL; file = find_event_file(tr, system, event); if (!file) goto out; enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; if (enable) ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops; else ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops; if (glob[0] == '!') { ret = unregister_ftrace_function_probe_func(glob+1, tr, ops); goto out; } ret = -ENOMEM; data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) goto out; data->enable = enable; data->count = -1; data->file = file; if (!param) goto out_reg; number = strsep(¶m, ":"); 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, &data->count); if (ret) goto out_free; out_reg: /* Don't let event modules unload while probe registered */ ret = try_module_get(file->event_call->mod); if (!ret) { ret = -EBUSY; goto out_free; } ret = __ftrace_event_enable_disable(file, 1, 1); if (ret < 0) goto out_put; ret = register_ftrace_function_probe(glob, tr, ops, data); /* * 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: mutex_unlock(&event_mutex); return ret; out_disable: __ftrace_event_enable_disable(file, 0, 1); out_put: module_put(file->event_call->mod); out_free: kfree(data); goto out; } static struct ftrace_func_command event_enable_cmd = { .name = ENABLE_EVENT_STR, .func = event_enable_func, }; static struct ftrace_func_command event_disable_cmd = { .name = DISABLE_EVENT_STR, .func = event_enable_func, }; static __init int register_event_cmds(void) { int ret; ret = register_ftrace_command(&event_enable_cmd); if (WARN_ON(ret < 0)) return ret; ret = register_ftrace_command(&event_disable_cmd); if (WARN_ON(ret < 0)) unregister_ftrace_command(&event_enable_cmd); return ret; } #else static inline int register_event_cmds(void) { return 0; } #endif /* CONFIG_DYNAMIC_FTRACE */ /* * The top level array has already had its trace_event_file * descriptors created in order to allow for early events to * be recorded. This function is called after the tracefs has been * initialized, and we now have to create the files associated * to the events. */ static __init void __trace_early_add_event_dirs(struct trace_array *tr) { struct trace_event_file *file; int ret; list_for_each_entry(file, &tr->events, list) { ret = event_create_dir(tr->event_dir, file); if (ret < 0) pr_warn("Could not create directory for event %s\n", trace_event_name(file->event_call)); } } /* * For early boot up, the top trace array requires to have * a list of events that can be enabled. This must be done before * the filesystem is set up in order to allow events to be traced * early. */ static __init void __trace_early_add_events(struct trace_array *tr) { struct trace_event_call *call; int ret; list_for_each_entry(call, &ftrace_events, list) { /* Early boot up should not have any modules loaded */ if (WARN_ON_ONCE(call->mod)) continue; ret = __trace_early_add_new_event(call, tr); if (ret < 0) pr_warn("Could not create early event %s\n", trace_event_name(call)); } } /* Remove the event directory structure for a trace directory. */ static void __trace_remove_event_dirs(struct trace_array *tr) { struct trace_event_file *file, *next; list_for_each_entry_safe(file, next, &tr->events, list) remove_event_file_dir(file); } static void __add_event_to_tracers(struct trace_event_call *call) { struct trace_array *tr; list_for_each_entry(tr, &ftrace_trace_arrays, list) __trace_add_new_event(call, tr); } extern struct trace_event_call *__start_ftrace_events[]; extern struct trace_event_call *__stop_ftrace_events[]; static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; static __init int setup_trace_event(char *str) { strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); ring_buffer_expanded = true; tracing_selftest_disabled = true; return 1; } __setup("trace_event=", setup_trace_event); /* Expects to have event_mutex held when called */ static int create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) { struct dentry *d_events; struct dentry *entry; entry = tracefs_create_file("set_event", 0644, parent, tr, &ftrace_set_event_fops); if (!entry) { pr_warn("Could not create tracefs 'set_event' entry\n"); return -ENOMEM; } d_events = tracefs_create_dir("events", parent); if (!d_events) { pr_warn("Could not create tracefs 'events' directory\n"); return -ENOMEM; } entry = trace_create_file("enable", 0644, d_events, tr, &ftrace_tr_enable_fops); if (!entry) { pr_warn("Could not create tracefs 'enable' entry\n"); return -ENOMEM; } /* There are not as crucial, just warn if they are not created */ entry = tracefs_create_file("set_event_pid", 0644, parent, tr, &ftrace_set_event_pid_fops); if (!entry) pr_warn("Could not create tracefs 'set_event_pid' entry\n"); /* ring buffer internal formats */ entry = trace_create_file("header_page", 0444, d_events, ring_buffer_print_page_header, &ftrace_show_header_fops); if (!entry) pr_warn("Could not create tracefs 'header_page' entry\n"); entry = trace_create_file("header_event", 0444, d_events, ring_buffer_print_entry_header, &ftrace_show_header_fops); if (!entry) pr_warn("Could not create tracefs 'header_event' entry\n"); tr->event_dir = d_events; return 0; } /** * event_trace_add_tracer - add a instance of a trace_array to events * @parent: The parent dentry to place the files/directories for events in * @tr: The trace array associated with these events * * When a new instance is created, it needs to set up its events * directory, as well as other files associated with events. It also * creates the event hierachry in the @parent/events directory. * * Returns 0 on success. * * Must be called with event_mutex held. */ int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr) { int ret; lockdep_assert_held(&event_mutex); ret = create_event_toplevel_files(parent, tr); if (ret) goto out; down_write(&trace_event_sem); __trace_add_event_dirs(tr); up_write(&trace_event_sem); out: return ret; } /* * The top trace array already had its file descriptors created. * Now the files themselves need to be created. */ static __init int early_event_add_tracer(struct dentry *parent, struct trace_array *tr) { int ret; mutex_lock(&event_mutex); ret = create_event_toplevel_files(parent, tr); if (ret) goto out_unlock; down_write(&trace_event_sem); __trace_early_add_event_dirs(tr); up_write(&trace_event_sem); out_unlock: mutex_unlock(&event_mutex); return ret; } /* Must be called with event_mutex held */ int event_trace_del_tracer(struct trace_array *tr) { lockdep_assert_held(&event_mutex); /* Disable any event triggers and associated soft-disabled events */ clear_event_triggers(tr); /* Clear the pid list */ __ftrace_clear_event_pids(tr); /* Disable any running events */ __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0); /* Make sure no more events are being executed */ tracepoint_synchronize_unregister(); down_write(&trace_event_sem); __trace_remove_event_dirs(tr); tracefs_remove_recursive(tr->event_dir); up_write(&trace_event_sem); tr->event_dir = NULL; return 0; } static __init int event_trace_memsetup(void) { field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC); file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC); return 0; } static __init void early_enable_events(struct trace_array *tr, bool disable_first) { char *buf = bootup_event_buf; char *token; int ret; while (true) { token = strsep(&buf, ","); if (!token) break; if (*token) { /* Restarting syscalls requires that we stop them first */ if (disable_first) ftrace_set_clr_event(tr, token, 0); ret = ftrace_set_clr_event(tr, token, 1); if (ret) pr_warn("Failed to enable trace event: %s\n", token); } /* Put back the comma to allow this to be called again */ if (buf) *(buf - 1) = ','; } } static __init int event_trace_enable(void) { struct trace_array *tr = top_trace_array(); struct trace_event_call **iter, *call; int ret; if (!tr) return -ENODEV; for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { call = *iter; ret = event_init(call); if (!ret) list_add(&call->list, &ftrace_events); } /* * We need the top trace array to have a working set of trace * points at early init, before the debug files and directories * are created. Create the file entries now, and attach them * to the actual file dentries later. */ __trace_early_add_events(tr); early_enable_events(tr, false); trace_printk_start_comm(); register_event_cmds(); register_trigger_cmds(); return 0; } /* * event_trace_enable() is called from trace_event_init() first to * initialize events and perhaps start any events that are on the * command line. Unfortunately, there are some events that will not * start this early, like the system call tracepoints that need * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable() * is called before pid 1 starts, and this flag is never set, making * the syscall tracepoint never get reached, but the event is enabled * regardless (and not doing anything). */ static __init int event_trace_enable_again(void) { struct trace_array *tr; tr = top_trace_array(); if (!tr) return -ENODEV; early_enable_events(tr, true); return 0; } early_initcall(event_trace_enable_again); __init int event_trace_init(void) { struct trace_array *tr; struct dentry *d_tracer; struct dentry *entry; int ret; tr = top_trace_array(); if (!tr) return -ENODEV; d_tracer = tracing_init_dentry(); if (IS_ERR(d_tracer)) return 0; entry = tracefs_create_file("available_events", 0444, d_tracer, tr, &ftrace_avail_fops); if (!entry) pr_warn("Could not create tracefs 'available_events' entry\n"); if (trace_define_generic_fields()) pr_warn("tracing: Failed to allocated generic fields"); if (trace_define_common_fields()) pr_warn("tracing: Failed to allocate common fields"); ret = early_event_add_tracer(d_tracer, tr); if (ret) return ret; #ifdef CONFIG_MODULES ret = register_module_notifier(&trace_module_nb); if (ret) pr_warn("Failed to register trace events module notifier\n"); #endif return 0; } void __init trace_event_init(void) { event_trace_memsetup(); init_ftrace_syscalls(); event_trace_enable(); } #ifdef CONFIG_FTRACE_STARTUP_TEST static DEFINE_SPINLOCK(test_spinlock); static DEFINE_SPINLOCK(test_spinlock_irq); static DEFINE_MUTEX(test_mutex); static __init void test_work(struct work_struct *dummy) { spin_lock(&test_spinlock); spin_lock_irq(&test_spinlock_irq); udelay(1); spin_unlock_irq(&test_spinlock_irq); spin_unlock(&test_spinlock); mutex_lock(&test_mutex); msleep(1); mutex_unlock(&test_mutex); } static __init int event_test_thread(void *unused) { void *test_malloc; test_malloc = kmalloc(1234, GFP_KERNEL); if (!test_malloc) pr_info("failed to kmalloc\n"); schedule_on_each_cpu(test_work); kfree(test_malloc); set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { schedule(); set_current_state(TASK_INTERRUPTIBLE); } __set_current_state(TASK_RUNNING); return 0; } /* * Do various things that may trigger events. */ static __init void event_test_stuff(void) { struct task_struct *test_thread; test_thread = kthread_run(event_test_thread, NULL, "test-events"); msleep(1); kthread_stop(test_thread); } /* * For every trace event defined, we will test each trace point separately, * and then by groups, and finally all trace points. */ static __init void event_trace_self_tests(void) { struct trace_subsystem_dir *dir; struct trace_event_file *file; struct trace_event_call *call; struct event_subsystem *system; struct trace_array *tr; int ret; tr = top_trace_array(); if (!tr) return; pr_info("Running tests on trace events:\n"); list_for_each_entry(file, &tr->events, list) { call = file->event_call; /* Only test those that have a probe */ if (!call->class || !call->class->probe) continue; /* * Testing syscall events here is pretty useless, but * we still do it if configured. But this is time consuming. * What we really need is a user thread to perform the * syscalls as we test. */ #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS if (call->class->system && strcmp(call->class->system, "syscalls") == 0) continue; #endif pr_info("Testing event %s: ", trace_event_name(call)); /* * If an event is already enabled, someone is using * it and the self test should not be on. */ if (file->flags & EVENT_FILE_FL_ENABLED) { pr_warn("Enabled event during self test!\n"); WARN_ON_ONCE(1); continue; } ftrace_event_enable_disable(file, 1); event_test_stuff(); ftrace_event_enable_disable(file, 0); pr_cont("OK\n"); } /* Now test at the sub system level */ pr_info("Running tests on trace event systems:\n"); list_for_each_entry(dir, &tr->systems, list) { system = dir->subsystem; /* the ftrace system is special, skip it */ if (strcmp(system->name, "ftrace") == 0) continue; pr_info("Testing event system %s: ", system->name); ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1); if (WARN_ON_ONCE(ret)) { pr_warn("error enabling system %s\n", system->name); continue; } event_test_stuff(); ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0); if (WARN_ON_ONCE(ret)) { pr_warn("error disabling system %s\n", system->name); continue; } pr_cont("OK\n"); } /* Test with all events enabled */ pr_info("Running tests on all trace events:\n"); pr_info("Testing all events: "); ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1); if (WARN_ON_ONCE(ret)) { pr_warn("error enabling all events\n"); return; } event_test_stuff(); /* reset sysname */ ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); if (WARN_ON_ONCE(ret)) { pr_warn("error disabling all events\n"); return; } pr_cont("OK\n"); } #ifdef CONFIG_FUNCTION_TRACER static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); static struct trace_event_file event_trace_file __initdata; static void __init function_test_events_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs) { struct ring_buffer_event *event; struct ring_buffer *buffer; struct ftrace_entry *entry; unsigned long flags; long disabled; int cpu; int pc; pc = preempt_count(); preempt_disable_notrace(); cpu = raw_smp_processor_id(); disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu)); if (disabled != 1) goto out; local_save_flags(flags); event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file, TRACE_FN, sizeof(*entry), flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); entry->ip = ip; entry->parent_ip = parent_ip; event_trigger_unlock_commit(&event_trace_file, buffer, event, entry, flags, pc); out: atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); preempt_enable_notrace(); } static struct ftrace_ops trace_ops __initdata = { .func = function_test_events_call, .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static __init void event_trace_self_test_with_function(void) { int ret; event_trace_file.tr = top_trace_array(); if (WARN_ON(!event_trace_file.tr)) return; ret = register_ftrace_function(&trace_ops); if (WARN_ON(ret < 0)) { pr_info("Failed to enable function tracer for event tests\n"); return; } pr_info("Running tests again, along with the function tracer\n"); event_trace_self_tests(); unregister_ftrace_function(&trace_ops); } #else static __init void event_trace_self_test_with_function(void) { } #endif static __init int event_trace_self_tests_init(void) { if (!tracing_selftest_disabled) { event_trace_self_tests(); event_trace_self_test_with_function(); } return 0; } late_initcall(event_trace_self_tests_init); #endif
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