/* * event tracer * * Copyright (C) 2008 Red Hat Inc, Steven Rostedt * * - Added format output of fields of the trace point. * This was based off of work by Tom Zanussi . * */ #include #include #include #include #include #include #include #include #include #include #include "trace_output.h" #undef TRACE_SYSTEM #define TRACE_SYSTEM "TRACE_SYSTEM" DEFINE_MUTEX(event_mutex); DEFINE_MUTEX(event_storage_mutex); EXPORT_SYMBOL_GPL(event_storage_mutex); char event_storage[EVENT_STORAGE_SIZE]; EXPORT_SYMBOL_GPL(event_storage); LIST_HEAD(ftrace_events); LIST_HEAD(ftrace_common_fields); #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO) static struct kmem_cache *field_cachep; static struct kmem_cache *file_cachep; /* 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 ftrace_event_file *___n; \ list_for_each_entry_safe(file, ___n, &tr->events, list) #define while_for_each_event_file() \ } struct list_head * trace_get_fields(struct ftrace_event_call *event_call) { if (!event_call->class->get_fields) return &event_call->class->fields; return event_call->class->get_fields(event_call); } 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) goto err; 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; err: kmem_cache_free(field_cachep, field); return -ENOMEM; } int trace_define_field(struct ftrace_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 __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_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; } void trace_destroy_fields(struct ftrace_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); } } int trace_event_raw_init(struct ftrace_event_call *call) { int id; id = register_ftrace_event(&call->event); if (!id) return -ENODEV; return 0; } EXPORT_SYMBOL_GPL(trace_event_raw_init); int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type, void *data) { struct ftrace_event_file *file = data; switch (type) { case TRACE_REG_REGISTER: return tracepoint_probe_register(call->name, call->class->probe, file); case TRACE_REG_UNREGISTER: tracepoint_probe_unregister(call->name, call->class->probe, file); return 0; #ifdef CONFIG_PERF_EVENTS case TRACE_REG_PERF_REGISTER: return tracepoint_probe_register(call->name, call->class->perf_probe, call); case TRACE_REG_PERF_UNREGISTER: tracepoint_probe_unregister(call->name, 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(ftrace_event_reg); void trace_event_enable_cmd_record(bool enable) { struct ftrace_event_file *file; struct trace_array *tr; mutex_lock(&event_mutex); do_for_each_event_file(tr, file) { if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) continue; if (enable) { tracing_start_cmdline_record(); set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } else { tracing_stop_cmdline_record(); clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } } while_for_each_event_file(); mutex_unlock(&event_mutex); } static int __ftrace_event_enable_disable(struct ftrace_event_file *file, int enable, int soft_disable) { struct ftrace_event_call *call = file->event_call; int ret = 0; int disable; switch (enable) { case 0: /* * When soft_disable is set and enable is cleared, 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) { disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED; clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags); } else disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE); if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) { clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags); if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) { tracing_stop_cmdline_record(); clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } call->class->reg(call, TRACE_REG_UNREGISTER, file); } /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */ if (file->flags & FTRACE_EVENT_FL_SOFT_MODE) set_bit(FTRACE_EVENT_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(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags); else set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags); if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) { /* Keep the event disabled, when going to SOFT_MODE. */ if (soft_disable) set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags); if (trace_flags & TRACE_ITER_RECORD_CMD) { tracing_start_cmdline_record(); set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } ret = call->class->reg(call, TRACE_REG_REGISTER, file); if (ret) { tracing_stop_cmdline_record(); pr_info("event trace: Could not enable event " "%s\n", call->name); break; } set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags); /* WAS_ENABLED gets set but never cleared. */ call->flags |= TRACE_EVENT_FL_WAS_ENABLED; } break; } return ret; } static int ftrace_event_enable_disable(struct ftrace_event_file *file, int enable) { return __ftrace_event_enable_disable(file, enable, 0); } static void ftrace_clear_events(struct trace_array *tr) { struct ftrace_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 __put_system(struct event_subsystem *system) { struct event_filter *filter = system->filter; WARN_ON_ONCE(system->ref_count == 0); if (--system->ref_count) return; list_del(&system->list); if (filter) { kfree(filter->filter_string); kfree(filter); } kfree(system); } static void __get_system(struct event_subsystem *system) { WARN_ON_ONCE(system->ref_count == 0); system->ref_count++; } static void __get_system_dir(struct ftrace_subsystem_dir *dir) { WARN_ON_ONCE(dir->ref_count == 0); dir->ref_count++; __get_system(dir->subsystem); } static void __put_system_dir(struct ftrace_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(dir->subsystem->ref_count == 1 && dir->ref_count != 1); __put_system(dir->subsystem); if (!--dir->ref_count) kfree(dir); } static void put_system(struct ftrace_subsystem_dir *dir) { mutex_lock(&event_mutex); __put_system_dir(dir); mutex_unlock(&event_mutex); } /* * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. */ static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, const char *sub, const char *event, int set) { struct ftrace_event_file *file; struct ftrace_event_call *call; int ret = -EINVAL; mutex_lock(&event_mutex); list_for_each_entry(file, &tr->events, list) { call = file->event_call; if (!call->name || !call->class || !call->class->reg) continue; if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) continue; if (match && strcmp(match, call->name) != 0 && strcmp(match, call->class->system) != 0) continue; if (sub && strcmp(sub, call->class->system) != 0) continue; if (event && strcmp(event, call->name) != 0) continue; ftrace_event_enable_disable(file, set); ret = 0; } 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; /* * The buf format can be : * *: means any event by that name. * : is the same. * * :* means all events in that subsystem * : means the same. * * (no ':') means all events in a subsystem with * the name or any event that matches */ 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; } return __ftrace_set_clr_event(tr, match, sub, event, set); } /** * 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(); 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; parser.buffer[parser.idx] = 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 ftrace_event_file *file = v; struct ftrace_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) return file; } return NULL; } static void *t_start(struct seq_file *m, loff_t *pos) { struct ftrace_event_file *file; struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); file = list_entry(&tr->events, struct ftrace_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 ftrace_event_file *file = v; struct trace_array *tr = m->private; (*pos)++; list_for_each_entry_continue(file, &tr->events, list) { if (file->flags & FTRACE_EVENT_FL_ENABLED) return file; } return NULL; } static void *s_start(struct seq_file *m, loff_t *pos) { struct ftrace_event_file *file; struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); file = list_entry(&tr->events, struct ftrace_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 ftrace_event_file *file = v; struct ftrace_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", call->name); return 0; } static void t_stop(struct seq_file *m, void *p) { mutex_unlock(&event_mutex); } static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct ftrace_event_file *file = filp->private_data; char *buf; if (file->flags & FTRACE_EVENT_FL_ENABLED) { if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED) buf = "0*\n"; else buf = "1\n"; } else buf = "0\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 ftrace_event_file *file = filp->private_data; unsigned long val; int ret; if (!file) return -EINVAL; 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: mutex_lock(&event_mutex); 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 ftrace_subsystem_dir *dir = filp->private_data; struct event_subsystem *system = dir->subsystem; struct ftrace_event_call *call; struct ftrace_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 (!call->name || !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 & FTRACE_EVENT_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 ftrace_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 ftrace_event_call *call = m->private; struct ftrace_event_field *field; struct list_head *common_head = &ftrace_common_fields; struct list_head *head = trace_get_fields(call); (*pos)++; switch ((unsigned long)v) { case FORMAT_HEADER: if (unlikely(list_empty(common_head))) return NULL; field = list_entry(common_head->prev, struct ftrace_event_field, link); return field; case FORMAT_FIELD_SEPERATOR: if (unlikely(list_empty(head))) return NULL; field = list_entry(head->prev, struct ftrace_event_field, link); return field; case FORMAT_PRINTFMT: /* all done */ return NULL; } field = v; if (field->link.prev == common_head) return (void *)FORMAT_FIELD_SEPERATOR; else if (field->link.prev == head) return (void *)FORMAT_PRINTFMT; field = list_entry(field->link.prev, struct ftrace_event_field, link); return field; } static void *f_start(struct seq_file *m, loff_t *pos) { loff_t l = 0; void *p; /* Start by showing the header */ if (!*pos) return (void *)FORMAT_HEADER; p = (void *)FORMAT_HEADER; do { p = f_next(m, p, &l); } while (p && l < *pos); return p; } static int f_show(struct seq_file *m, void *v) { struct ftrace_event_call *call = m->private; struct ftrace_event_field *field; const char *array_descriptor; switch ((unsigned long)v) { case FORMAT_HEADER: seq_printf(m, "name: %s\n", call->name); seq_printf(m, "ID: %d\n", call->event.type); seq_printf(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 = v; /* * 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 (!strncmp(field->type, "__data_loc", 10)) 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_stop(struct seq_file *m, void *p) { } 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 ftrace_event_call *call = inode->i_private; 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 = call; return 0; } static ssize_t event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct ftrace_event_call *call = 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); trace_seq_printf(s, "%d\n", call->event.type); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); return r; } static ssize_t event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct ftrace_event_call *call = 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); print_event_filter(call, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); return r; } static ssize_t event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct ftrace_event_call *call = filp->private_data; char *buf; int err; if (cnt >= PAGE_SIZE) return -EINVAL; buf = (char *)__get_free_page(GFP_TEMPORARY); if (!buf) return -ENOMEM; if (copy_from_user(buf, ubuf, cnt)) { free_page((unsigned long) buf); return -EFAULT; } buf[cnt] = '\0'; err = apply_event_filter(call, buf); free_page((unsigned long) 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 ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */ struct trace_array *tr; int ret; /* Make sure the system still exists */ mutex_lock(&event_mutex); 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(&event_mutex); if (!system) return -ENODEV; /* Some versions of gcc think dir can be uninitialized here */ WARN_ON(!dir); ret = tracing_open_generic(inode, filp); if (ret < 0) put_system(dir); return ret; } static int system_tr_open(struct inode *inode, struct file *filp) { struct ftrace_subsystem_dir *dir; struct trace_array *tr = inode->i_private; int ret; /* Make a temporary dir that has no system but points to tr */ dir = kzalloc(sizeof(*dir), GFP_KERNEL); if (!dir) return -ENOMEM; dir->tr = tr; ret = tracing_open_generic(inode, filp); if (ret < 0) kfree(dir); filp->private_data = dir; return ret; } static int subsystem_release(struct inode *inode, struct file *file) { struct ftrace_subsystem_dir *dir = file->private_data; /* * 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 ftrace_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, s->len); kfree(s); return r; } static ssize_t subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct ftrace_subsystem_dir *dir = filp->private_data; char *buf; int err; if (cnt >= PAGE_SIZE) return -EINVAL; buf = (char *)__get_free_page(GFP_TEMPORARY); if (!buf) return -ENOMEM; if (copy_from_user(buf, ubuf, cnt)) { free_page((unsigned long) buf); return -EFAULT; } buf[cnt] = '\0'; err = apply_subsystem_event_filter(dir, buf); free_page((unsigned long) 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, s->len); kfree(s); return r; } 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 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 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 = seq_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 = { .open = tracing_open_generic, .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_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; if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) ftrace_clear_events(tr); return ftrace_event_open(inode, file, seq_ops); } 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; system->name = name; 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(system); return NULL; } static struct dentry * event_subsystem_dir(struct trace_array *tr, const char *name, struct ftrace_event_file *file, struct dentry *parent) { struct ftrace_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 = debugfs_create_dir(name, parent); if (!dir->entry) { pr_warning("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 = debugfs_create_file("filter", 0644, dir->entry, dir, &ftrace_subsystem_filter_fops); if (!entry) { kfree(system->filter); system->filter = NULL; pr_warning("Could not create debugfs '%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_warning("No memory to create event subsystem %s\n", name); return NULL; } static int event_create_dir(struct dentry *parent, struct ftrace_event_file *file, const struct file_operations *id, const struct file_operations *enable, const struct file_operations *filter, const struct file_operations *format) { struct ftrace_event_call *call = file->event_call; struct trace_array *tr = file->tr; struct list_head *head; struct dentry *d_events; 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; file->dir = debugfs_create_dir(call->name, d_events); if (!file->dir) { pr_warning("Could not create debugfs '%s' directory\n", call->name); return -1; } if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) trace_create_file("enable", 0644, file->dir, file, enable); #ifdef CONFIG_PERF_EVENTS if (call->event.type && call->class->reg) trace_create_file("id", 0444, file->dir, call, id); #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_warning("Could not initialize trace point" " events/%s\n", call->name); return -1; } } trace_create_file("filter", 0644, file->dir, call, filter); trace_create_file("format", 0444, file->dir, call, format); return 0; } static void remove_subsystem(struct ftrace_subsystem_dir *dir) { if (!dir) return; if (!--dir->nr_events) { debugfs_remove_recursive(dir->entry); list_del(&dir->list); __put_system_dir(dir); } } static void remove_event_from_tracers(struct ftrace_event_call *call) { struct ftrace_event_file *file; struct trace_array *tr; do_for_each_event_file_safe(tr, file) { if (file->event_call != call) continue; list_del(&file->list); debugfs_remove_recursive(file->dir); remove_subsystem(file->system); kmem_cache_free(file_cachep, 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 ftrace_event_call *call) { struct trace_array *tr; struct ftrace_event_file *file; do_for_each_event_file(tr, file) { if (file->event_call != call) continue; 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_ftrace_event(&call->event); remove_event_from_tracers(call); list_del(&call->list); } static int event_init(struct ftrace_event_call *call) { int ret = 0; if (WARN_ON(!call->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", call->name); } return ret; } static int __register_event(struct ftrace_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; } /* Add an event to a trace directory */ static int __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr, const struct file_operations *id, const struct file_operations *enable, const struct file_operations *filter, const struct file_operations *format) { struct ftrace_event_file *file; file = kmem_cache_alloc(file_cachep, GFP_TRACE); if (!file) return -ENOMEM; file->event_call = call; file->tr = tr; list_add(&file->list, &tr->events); return event_create_dir(tr->event_dir, file, id, enable, filter, format); } /* * 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 ftrace_event_call *call, struct trace_array *tr) { struct ftrace_event_file *file; file = kmem_cache_alloc(file_cachep, GFP_TRACE); if (!file) return -ENOMEM; file->event_call = call; file->tr = tr; list_add(&file->list, &tr->events); return 0; } struct ftrace_module_file_ops; static void __add_event_to_tracers(struct ftrace_event_call *call, struct ftrace_module_file_ops *file_ops); /* Add an additional event_call dynamically */ int trace_add_event_call(struct ftrace_event_call *call) { int ret; mutex_lock(&event_mutex); ret = __register_event(call, NULL); if (ret >= 0) __add_event_to_tracers(call, NULL); mutex_unlock(&event_mutex); return ret; } /* * Must be called under locking both of event_mutex and trace_event_mutex. */ static void __trace_remove_event_call(struct ftrace_event_call *call) { event_remove(call); trace_destroy_fields(call); destroy_preds(call); } /* Remove an event_call */ void trace_remove_event_call(struct ftrace_event_call *call) { mutex_lock(&event_mutex); down_write(&trace_event_mutex); __trace_remove_event_call(call); up_write(&trace_event_mutex); mutex_unlock(&event_mutex); } #define for_each_event(event, start, end) \ for (event = start; \ (unsigned long)event < (unsigned long)end; \ event++) #ifdef CONFIG_MODULES static LIST_HEAD(ftrace_module_file_list); /* * Modules must own their file_operations to keep up with * reference counting. */ struct ftrace_module_file_ops { struct list_head list; struct module *mod; struct file_operations id; struct file_operations enable; struct file_operations format; struct file_operations filter; }; static struct ftrace_module_file_ops * find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) { /* * As event_calls are added in groups by module, * when we find one file_ops, we don't need to search for * each call in that module, as the rest should be the * same. Only search for a new one if the last one did * not match. */ if (file_ops && mod == file_ops->mod) return file_ops; list_for_each_entry(file_ops, &ftrace_module_file_list, list) { if (file_ops->mod == mod) return file_ops; } return NULL; } static struct ftrace_module_file_ops * trace_create_file_ops(struct module *mod) { struct ftrace_module_file_ops *file_ops; /* * This is a bit of a PITA. To allow for correct reference * counting, modules must "own" their file_operations. * To do this, we allocate the file operations that will be * used in the event directory. */ file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL); if (!file_ops) return NULL; file_ops->mod = mod; file_ops->id = ftrace_event_id_fops; file_ops->id.owner = mod; file_ops->enable = ftrace_enable_fops; file_ops->enable.owner = mod; file_ops->filter = ftrace_event_filter_fops; file_ops->filter.owner = mod; file_ops->format = ftrace_event_format_fops; file_ops->format.owner = mod; list_add(&file_ops->list, &ftrace_module_file_list); return file_ops; } static void trace_module_add_events(struct module *mod) { struct ftrace_module_file_ops *file_ops = NULL; struct ftrace_event_call **call, **start, **end; start = mod->trace_events; end = mod->trace_events + mod->num_trace_events; if (start == end) return; file_ops = trace_create_file_ops(mod); if (!file_ops) return; for_each_event(call, start, end) { __register_event(*call, mod); __add_event_to_tracers(*call, file_ops); } } static void trace_module_remove_events(struct module *mod) { struct ftrace_module_file_ops *file_ops; struct ftrace_event_call *call, *p; bool clear_trace = false; down_write(&trace_event_mutex); list_for_each_entry_safe(call, p, &ftrace_events, list) { if (call->mod == mod) { if (call->flags & TRACE_EVENT_FL_WAS_ENABLED) clear_trace = true; __trace_remove_event_call(call); } } /* Now free the file_operations */ list_for_each_entry(file_ops, &ftrace_module_file_list, list) { if (file_ops->mod == mod) break; } if (&file_ops->list != &ftrace_module_file_list) { list_del(&file_ops->list); kfree(file_ops); } up_write(&trace_event_mutex); /* * 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. */ if (clear_trace) 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); switch (val) { case MODULE_STATE_COMING: trace_module_add_events(mod); break; case MODULE_STATE_GOING: trace_module_remove_events(mod); break; } mutex_unlock(&event_mutex); return 0; } static int __trace_add_new_mod_event(struct ftrace_event_call *call, struct trace_array *tr, struct ftrace_module_file_ops *file_ops) { return __trace_add_new_event(call, tr, &file_ops->id, &file_ops->enable, &file_ops->filter, &file_ops->format); } #else static inline struct ftrace_module_file_ops * find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) { return NULL; } static inline int trace_module_notify(struct notifier_block *self, unsigned long val, void *data) { return 0; } static inline int __trace_add_new_mod_event(struct ftrace_event_call *call, struct trace_array *tr, struct ftrace_module_file_ops *file_ops) { return -ENODEV; } #endif /* CONFIG_MODULES */ /* Create a new event directory structure for a trace directory. */ static void __trace_add_event_dirs(struct trace_array *tr) { struct ftrace_module_file_ops *file_ops = NULL; struct ftrace_event_call *call; int ret; list_for_each_entry(call, &ftrace_events, list) { if (call->mod) { /* * Directories for events by modules need to * keep module ref counts when opened (as we don't * want the module to disappear when reading one * of these files). The file_ops keep account of * the module ref count. */ file_ops = find_ftrace_file_ops(file_ops, call->mod); if (!file_ops) continue; /* Warn? */ ret = __trace_add_new_mod_event(call, tr, file_ops); if (ret < 0) pr_warning("Could not create directory for event %s\n", call->name); continue; } ret = __trace_add_new_event(call, tr, &ftrace_event_id_fops, &ftrace_enable_fops, &ftrace_event_filter_fops, &ftrace_event_format_fops); if (ret < 0) pr_warning("Could not create directory for event %s\n", call->name); } } #ifdef CONFIG_DYNAMIC_FTRACE /* Avoid typos */ #define ENABLE_EVENT_STR "enable_event" #define DISABLE_EVENT_STR "disable_event" struct event_probe_data { struct ftrace_event_file *file; unsigned long count; int ref; bool enable; }; static struct ftrace_event_file * find_event_file(struct trace_array *tr, const char *system, const char *event) { struct ftrace_event_file *file; struct ftrace_event_call *call; list_for_each_entry(file, &tr->events, list) { call = file->event_call; if (!call->name || !call->class || !call->class->reg) continue; if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) continue; if (strcmp(event, call->name) == 0 && strcmp(system, call->class->system) == 0) return file; } return NULL; } static void event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data) { struct event_probe_data **pdata = (struct event_probe_data **)_data; struct event_probe_data *data = *pdata; if (!data) return; if (data->enable) clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags); else set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags); } static void event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data) { struct event_probe_data **pdata = (struct event_probe_data **)_data; struct event_probe_data *data = *pdata; if (!data) return; if (!data->count) return; /* Skip if the event is in a state we want to switch to */ if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)) return; if (data->count != -1) (data->count)--; event_enable_probe(ip, parent_ip, _data); } static int event_enable_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *_data) { struct event_probe_data *data = _data; seq_printf(m, "%ps:", (void *)ip); seq_printf(m, "%s:%s:%s", data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, data->file->event_call->class->system, data->file->event_call->name); if (data->count == -1) seq_printf(m, ":unlimited\n"); else seq_printf(m, ":count=%ld\n", data->count); return 0; } static int event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip, void **_data) { struct event_probe_data **pdata = (struct event_probe_data **)_data; struct event_probe_data *data = *pdata; data->ref++; return 0; } static void event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip, void **_data) { struct event_probe_data **pdata = (struct event_probe_data **)_data; struct event_probe_data *data = *pdata; if (WARN_ON_ONCE(data->ref <= 0)) return; data->ref--; if (!data->ref) { /* Remove the SOFT_MODE flag */ __ftrace_event_enable_disable(data->file, 0, 1); module_put(data->file->event_call->mod); kfree(data); } *pdata = NULL; } 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 ftrace_hash *hash, char *glob, char *cmd, char *param, int enabled) { struct trace_array *tr = top_trace_array(); struct ftrace_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; /* hash funcs only work with set_ftrace_filter */ if (!enabled) return -EINVAL; if (!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] == '!') { unregister_ftrace_function_probe_func(glob+1, ops); ret = 0; 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) goto out_free; ret = __ftrace_event_enable_disable(file, 1, 1); if (ret < 0) goto out_put; ret = register_ftrace_function_probe(glob, ops, data); if (!ret) goto out_disable; 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 ftrace_event_file * descriptors created in order to allow for early events to * be recorded. This function is called after the debugfs 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 ftrace_event_file *file; int ret; list_for_each_entry(file, &tr->events, list) { ret = event_create_dir(tr->event_dir, file, &ftrace_event_id_fops, &ftrace_enable_fops, &ftrace_event_filter_fops, &ftrace_event_format_fops); if (ret < 0) pr_warning("Could not create directory for event %s\n", file->event_call->name); } } /* * 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 ftrace_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_warning("Could not create early event %s\n", call->name); } } /* Remove the event directory structure for a trace directory. */ static void __trace_remove_event_dirs(struct trace_array *tr) { struct ftrace_event_file *file, *next; list_for_each_entry_safe(file, next, &tr->events, list) { list_del(&file->list); debugfs_remove_recursive(file->dir); remove_subsystem(file->system); kmem_cache_free(file_cachep, file); } } static void __add_event_to_tracers(struct ftrace_event_call *call, struct ftrace_module_file_ops *file_ops) { struct trace_array *tr; list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (file_ops) __trace_add_new_mod_event(call, tr, file_ops); else __trace_add_new_event(call, tr, &ftrace_event_id_fops, &ftrace_enable_fops, &ftrace_event_filter_fops, &ftrace_event_format_fops); } } static struct notifier_block trace_module_nb = { .notifier_call = trace_module_notify, .priority = 0, }; extern struct ftrace_event_call *__start_ftrace_events[]; extern struct ftrace_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 = debugfs_create_file("set_event", 0644, parent, tr, &ftrace_set_event_fops); if (!entry) { pr_warning("Could not create debugfs 'set_event' entry\n"); return -ENOMEM; } d_events = debugfs_create_dir("events", parent); if (!d_events) { pr_warning("Could not create debugfs 'events' directory\n"); return -ENOMEM; } /* ring buffer internal formats */ trace_create_file("header_page", 0444, d_events, ring_buffer_print_page_header, &ftrace_show_header_fops); trace_create_file("header_event", 0444, d_events, ring_buffer_print_entry_header, &ftrace_show_header_fops); trace_create_file("enable", 0644, d_events, tr, &ftrace_tr_enable_fops); 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. */ int event_trace_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_mutex); __trace_add_event_dirs(tr); up_write(&trace_event_mutex); out_unlock: mutex_unlock(&event_mutex); 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_mutex); __trace_early_add_event_dirs(tr); up_write(&trace_event_mutex); out_unlock: mutex_unlock(&event_mutex); return ret; } int event_trace_del_tracer(struct trace_array *tr) { /* Disable any running events */ __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); mutex_lock(&event_mutex); down_write(&trace_event_mutex); __trace_remove_event_dirs(tr); debugfs_remove_recursive(tr->event_dir); up_write(&trace_event_mutex); tr->event_dir = NULL; mutex_unlock(&event_mutex); return 0; } static __init int event_trace_memsetup(void) { field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC); file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC); return 0; } static __init int event_trace_enable(void) { struct trace_array *tr = top_trace_array(); struct ftrace_event_call **iter, *call; char *buf = bootup_event_buf; char *token; int ret; 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); while (true) { token = strsep(&buf, ","); if (!token) break; if (!*token) continue; ret = ftrace_set_clr_event(tr, token, 1); if (ret) pr_warn("Failed to enable trace event: %s\n", token); } trace_printk_start_comm(); register_event_cmds(); return 0; } static __init int event_trace_init(void) { struct trace_array *tr; struct dentry *d_tracer; struct dentry *entry; int ret; tr = top_trace_array(); d_tracer = tracing_init_dentry(); if (!d_tracer) return 0; entry = debugfs_create_file("available_events", 0444, d_tracer, tr, &ftrace_avail_fops); if (!entry) pr_warning("Could not create debugfs " "'available_events' entry\n"); if (trace_define_common_fields()) pr_warning("tracing: Failed to allocate common fields"); ret = early_event_add_tracer(d_tracer, tr); if (ret) return ret; ret = register_module_notifier(&trace_module_nb); if (ret) pr_warning("Failed to register trace events module notifier\n"); return 0; } early_initcall(event_trace_memsetup); core_initcall(event_trace_enable); fs_initcall(event_trace_init); #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(); 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 ftrace_subsystem_dir *dir; struct ftrace_event_file *file; struct ftrace_event_call *call; struct event_subsystem *system; struct trace_array *tr; int ret; tr = top_trace_array(); 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: ", call->name); /* * If an event is already enabled, someone is using * it and the self test should not be on. */ if (file->flags & FTRACE_EVENT_FL_ENABLED) { pr_warning("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_warning("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_warning("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_warning("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_warning("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 void 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_current_buffer_lock_reserve(&buffer, TRACE_FN, sizeof(*entry), flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); entry->ip = ip; entry->parent_ip = parent_ip; trace_buffer_unlock_commit(buffer, event, 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; 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