*
* 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>.
+ *
*/
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/kthread.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ctype.h>
+#include <linux/delay.h>
-#include "trace_events.h"
+#include <asm/setup.h>
-#define events_for_each(event) \
- for (event = __start_ftrace_events; \
- (unsigned long)event < (unsigned long)__stop_ftrace_events; \
- event++)
+#include "trace_output.h"
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM "TRACE_SYSTEM"
+
+DEFINE_MUTEX(event_mutex);
+
+LIST_HEAD(ftrace_events);
+
+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 ftrace_event_field *field;
+
+ field = kzalloc(sizeof(*field), GFP_KERNEL);
+ if (!field)
+ goto err;
+
+ field->name = kstrdup(name, GFP_KERNEL);
+ if (!field->name)
+ goto err;
+
+ field->type = kstrdup(type, GFP_KERNEL);
+ if (!field->type)
+ goto err;
+
+ 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, &call->fields);
+
+ return 0;
-void event_trace_printk(unsigned long ip, const char *fmt, ...)
+err:
+ if (field) {
+ kfree(field->name);
+ kfree(field->type);
+ }
+ kfree(field);
+
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(trace_define_field);
+
+#define __common_field(type, item) \
+ ret = trace_define_field(call, #type, "common_" #item, \
+ offsetof(typeof(ent), item), \
+ sizeof(ent.item), \
+ is_signed_type(type), FILTER_OTHER); \
+ if (ret) \
+ return ret;
+
+int trace_define_common_fields(struct ftrace_event_call *call)
{
- va_list ap;
+ int ret;
+ struct trace_entry ent;
- va_start(ap, fmt);
- tracing_record_cmdline(current);
- trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
- va_end(ap);
+ __common_field(unsigned short, type);
+ __common_field(unsigned char, flags);
+ __common_field(unsigned char, preempt_count);
+ __common_field(int, pid);
+ __common_field(int, lock_depth);
+
+ return ret;
}
+EXPORT_SYMBOL_GPL(trace_define_common_fields);
-static void ftrace_clear_events(void)
+#ifdef CONFIG_MODULES
+
+static void trace_destroy_fields(struct ftrace_event_call *call)
{
- struct ftrace_event_call *call = (void *)__start_ftrace_events;
+ struct ftrace_event_field *field, *next;
+ list_for_each_entry_safe(field, next, &call->fields, link) {
+ list_del(&field->link);
+ kfree(field->type);
+ kfree(field->name);
+ kfree(field);
+ }
+}
- while ((unsigned long)call < (unsigned long)__stop_ftrace_events) {
+#endif /* CONFIG_MODULES */
+static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+ int enable)
+{
+ switch (enable) {
+ case 0:
if (call->enabled) {
call->enabled = 0;
- call->unregfunc();
+ tracing_stop_cmdline_record();
+ call->unregfunc(call->data);
}
- call++;
+ break;
+ case 1:
+ if (!call->enabled) {
+ call->enabled = 1;
+ tracing_start_cmdline_record();
+ call->regfunc(call->data);
+ }
+ break;
}
}
-static int ftrace_set_clr_event(char *buf, int set)
+static void ftrace_clear_events(void)
{
- struct ftrace_event_call *call = __start_ftrace_events;
+ struct ftrace_event_call *call;
+
+ mutex_lock(&event_mutex);
+ list_for_each_entry(call, &ftrace_events, list) {
+ ftrace_event_enable_disable(call, 0);
+ }
+ mutex_unlock(&event_mutex);
+}
+/*
+ * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
+ */
+static int __ftrace_set_clr_event(const char *match, const char *sub,
+ const char *event, int set)
+{
+ struct ftrace_event_call *call;
+ int ret = -EINVAL;
- events_for_each(call) {
+ mutex_lock(&event_mutex);
+ list_for_each_entry(call, &ftrace_events, list) {
- if (!call->name)
+ if (!call->name || !call->regfunc)
continue;
- if (strcmp(buf, call->name) != 0)
+ if (match &&
+ strcmp(match, call->name) != 0 &&
+ strcmp(match, call->system) != 0)
continue;
- if (set) {
- /* Already set? */
- if (call->enabled)
- return 0;
- call->enabled = 1;
- call->regfunc();
- } else {
- /* Already cleared? */
- if (!call->enabled)
- return 0;
- call->enabled = 0;
- call->unregfunc();
- }
- return 0;
+ if (sub && strcmp(sub, call->system) != 0)
+ continue;
+
+ if (event && strcmp(event, call->name) != 0)
+ continue;
+
+ ftrace_event_enable_disable(call, set);
+
+ ret = 0;
}
- return -EINVAL;
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+static int ftrace_set_clr_event(char *buf, int set)
+{
+ char *event = NULL, *sub = NULL, *match;
+
+ /*
+ * 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;
+ }
+
+ return __ftrace_set_clr_event(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)
+{
+ return __ftrace_set_clr_event(NULL, system, event, set);
}
/* 128 should be much more than enough */
ftrace_event_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
+ struct trace_parser parser;
size_t read = 0;
- int i, set = 1;
ssize_t ret;
- char *buf;
- char ch;
if (!cnt || cnt < 0)
return 0;
- ret = get_user(ch, ubuf++);
- if (ret)
- return ret;
- read++;
- cnt--;
-
- /* skip white space */
- while (cnt && isspace(ch)) {
- ret = get_user(ch, ubuf++);
- if (ret)
- return ret;
- read++;
- cnt--;
- }
-
- /* Only white space found? */
- if (isspace(ch)) {
- file->f_pos += read;
- ret = read;
+ ret = tracing_update_buffers();
+ if (ret < 0)
return ret;
- }
- buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL);
- if (!buf)
+ if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
return -ENOMEM;
- if (cnt > EVENT_BUF_SIZE)
- cnt = EVENT_BUF_SIZE;
+ read = trace_get_user(&parser, ubuf, cnt, ppos);
+
+ if (trace_parser_loaded((&parser))) {
+ int set = 1;
- i = 0;
- while (cnt && !isspace(ch)) {
- if (!i && ch == '!')
+ if (*parser.buffer == '!')
set = 0;
- else
- buf[i++] = ch;
- ret = get_user(ch, ubuf++);
+ parser.buffer[parser.idx] = 0;
+
+ ret = ftrace_set_clr_event(parser.buffer + !set, set);
if (ret)
- goto out_free;
- read++;
- cnt--;
+ goto out_put;
}
- buf[i] = 0;
-
- file->f_pos += read;
-
- ret = ftrace_set_clr_event(buf, set);
- if (ret)
- goto out_free;
ret = read;
- out_free:
- kfree(buf);
+ out_put:
+ trace_parser_put(&parser);
return ret;
}
static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = m->private;
- struct ftrace_event_call *next = call;
+ struct list_head *list = m->private;
+ struct ftrace_event_call *call;
(*pos)++;
- if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
- return NULL;
+ for (;;) {
+ if (list == &ftrace_events)
+ return NULL;
+
+ call = list_entry(list, struct ftrace_event_call, list);
- m->private = ++next;
+ /*
+ * The ftrace subsystem is for showing formats only.
+ * They can not be enabled or disabled via the event files.
+ */
+ if (call->regfunc)
+ break;
+
+ list = list->next;
+ }
+
+ m->private = list->next;
return call;
}
static void *t_start(struct seq_file *m, loff_t *pos)
{
- return t_next(m, NULL, pos);
+ struct ftrace_event_call *call = NULL;
+ loff_t l;
+
+ mutex_lock(&event_mutex);
+
+ m->private = ftrace_events.next;
+ for (l = 0; l <= *pos; ) {
+ call = t_next(m, NULL, &l);
+ if (!call)
+ break;
+ }
+ return call;
}
static void *
s_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = m->private;
- struct ftrace_event_call *next;
+ struct list_head *list = m->private;
+ struct ftrace_event_call *call;
(*pos)++;
retry:
- if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
+ if (list == &ftrace_events)
return NULL;
+ call = list_entry(list, struct ftrace_event_call, list);
+
if (!call->enabled) {
- call++;
+ list = list->next;
goto retry;
}
- next = call;
- m->private = ++next;
+ m->private = list->next;
return call;
}
static void *s_start(struct seq_file *m, loff_t *pos)
{
- return s_next(m, NULL, pos);
+ struct ftrace_event_call *call = NULL;
+ loff_t l;
+
+ mutex_lock(&event_mutex);
+
+ m->private = ftrace_events.next;
+ for (l = 0; l <= *pos; ) {
+ call = s_next(m, NULL, &l);
+ if (!call)
+ break;
+ }
+ return call;
}
static int t_show(struct seq_file *m, void *v)
{
struct ftrace_event_call *call = v;
+ if (strcmp(call->system, TRACE_SYSTEM) != 0)
+ seq_printf(m, "%s:", call->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 int
ftrace_event_seq_open(struct inode *inode, struct file *file)
{
- int ret;
const struct seq_operations *seq_ops;
if ((file->f_mode & FMODE_WRITE) &&
- !(file->f_flags & O_APPEND))
+ (file->f_flags & O_TRUNC))
ftrace_clear_events();
seq_ops = inode->i_private;
- ret = seq_open(file, seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
-
- m->private = __start_ftrace_events;
- }
- return ret;
+ return seq_open(file, seq_ops);
}
static ssize_t
if (ret < 0)
return ret;
+ ret = tracing_update_buffers();
+ if (ret < 0)
+ return ret;
+
switch (val) {
case 0:
- if (!call->enabled)
- break;
-
- call->enabled = 0;
- call->unregfunc();
- break;
case 1:
- if (call->enabled)
- break;
-
- call->enabled = 1;
- call->regfunc();
+ mutex_lock(&event_mutex);
+ ftrace_event_enable_disable(call, val);
+ mutex_unlock(&event_mutex);
break;
default:
return 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' };
+ const char *system = filp->private_data;
+ struct ftrace_event_call *call;
+ char buf[2];
+ int set = 0;
+ int ret;
+
+ mutex_lock(&event_mutex);
+ list_for_each_entry(call, &ftrace_events, list) {
+ if (!call->name || !call->regfunc)
+ continue;
+
+ if (system && strcmp(call->system, system) != 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 << !!call->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)
+{
+ const char *system = filp->private_data;
+ unsigned long val;
+ char buf[64];
+ ssize_t ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = tracing_update_buffers();
+ if (ret < 0)
+ return ret;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ ret = __ftrace_set_clr_event(NULL, system, NULL, val);
+ if (ret)
+ goto out;
+
+ ret = cnt;
+
+out:
+ *ppos += cnt;
+
+ return ret;
+}
+
+extern char *__bad_type_size(void);
+
+#undef FIELD
+#define FIELD(type, name) \
+ sizeof(type) != sizeof(field.name) ? __bad_type_size() : \
+ #type, "common_" #name, offsetof(typeof(field), name), \
+ sizeof(field.name)
+
+static int trace_write_header(struct trace_seq *s)
+{
+ struct trace_entry field;
+
+ /* struct trace_entry */
+ return trace_seq_printf(s,
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\n",
+ FIELD(unsigned short, type),
+ FIELD(unsigned char, flags),
+ FIELD(unsigned char, preempt_count),
+ FIELD(int, pid),
+ FIELD(int, lock_depth));
+}
+
+static ssize_t
+event_format_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;
+ char *buf;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ /* If any of the first writes fail, so will the show_format. */
+
+ trace_seq_printf(s, "name: %s\n", call->name);
+ trace_seq_printf(s, "ID: %d\n", call->id);
+ trace_seq_printf(s, "format:\n");
+ trace_write_header(s);
+
+ r = call->show_format(call, s);
+ if (!r) {
+ /*
+ * ug! The format output is bigger than a PAGE!!
+ */
+ buf = "FORMAT TOO BIG\n";
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, strlen(buf));
+ goto out;
+ }
+
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ s->buffer, s->len);
+ out:
+ kfree(s);
+ return r;
+}
+
+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->id);
+
+ 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 ssize_t
+subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct event_subsystem *system = 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_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 event_subsystem *system = 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(system, 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 const struct seq_operations show_event_seq_ops = {
.start = t_start,
.next = t_next,
.write = event_enable_write,
};
+static const struct file_operations ftrace_event_format_fops = {
+ .open = tracing_open_generic,
+ .read = event_format_read,
+};
+
+static const struct file_operations ftrace_event_id_fops = {
+ .open = tracing_open_generic,
+ .read = event_id_read,
+};
+
+static const struct file_operations ftrace_event_filter_fops = {
+ .open = tracing_open_generic,
+ .read = event_filter_read,
+ .write = event_filter_write,
+};
+
+static const struct file_operations ftrace_subsystem_filter_fops = {
+ .open = tracing_open_generic,
+ .read = subsystem_filter_read,
+ .write = subsystem_filter_write,
+};
+
+static const struct file_operations ftrace_system_enable_fops = {
+ .open = tracing_open_generic,
+ .read = system_enable_read,
+ .write = system_enable_write,
+};
+
+static const struct file_operations ftrace_show_header_fops = {
+ .open = tracing_open_generic,
+ .read = show_header,
+};
+
static struct dentry *event_trace_events_dir(void)
{
static struct dentry *d_tracer;
return d_events;
}
+static LIST_HEAD(event_subsystems);
+
+static struct dentry *
+event_subsystem_dir(const char *name, struct dentry *d_events)
+{
+ struct event_subsystem *system;
+ struct dentry *entry;
+
+ /* First see if we did not already create this dir */
+ list_for_each_entry(system, &event_subsystems, list) {
+ if (strcmp(system->name, name) == 0) {
+ system->nr_events++;
+ return system->entry;
+ }
+ }
+
+ /* need to create new entry */
+ system = kmalloc(sizeof(*system), GFP_KERNEL);
+ if (!system) {
+ pr_warning("No memory to create event subsystem %s\n",
+ name);
+ return d_events;
+ }
+
+ system->entry = debugfs_create_dir(name, d_events);
+ if (!system->entry) {
+ pr_warning("Could not create event subsystem %s\n",
+ name);
+ kfree(system);
+ return d_events;
+ }
+
+ system->nr_events = 1;
+ system->name = kstrdup(name, GFP_KERNEL);
+ if (!system->name) {
+ debugfs_remove(system->entry);
+ kfree(system);
+ return d_events;
+ }
+
+ list_add(&system->list, &event_subsystems);
+
+ system->filter = NULL;
+
+ system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
+ if (!system->filter) {
+ pr_warning("Could not allocate filter for subsystem "
+ "'%s'\n", name);
+ return system->entry;
+ }
+
+ entry = debugfs_create_file("filter", 0644, system->entry, system,
+ &ftrace_subsystem_filter_fops);
+ if (!entry) {
+ kfree(system->filter);
+ system->filter = NULL;
+ pr_warning("Could not create debugfs "
+ "'%s/filter' entry\n", name);
+ }
+
+ entry = trace_create_file("enable", 0644, system->entry,
+ (void *)system->name,
+ &ftrace_system_enable_fops);
+
+ return system->entry;
+}
+
static int
-event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
+event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
+ const struct file_operations *id,
+ const struct file_operations *enable,
+ const struct file_operations *filter,
+ const struct file_operations *format)
{
struct dentry *entry;
+ int ret;
+
+ /*
+ * If the trace point header did not define TRACE_SYSTEM
+ * then the system would be called "TRACE_SYSTEM".
+ */
+ if (strcmp(call->system, TRACE_SYSTEM) != 0)
+ d_events = event_subsystem_dir(call->system, d_events);
call->dir = debugfs_create_dir(call->name, d_events);
if (!call->dir) {
return -1;
}
- entry = debugfs_create_file("enable", 0644, call->dir, call,
- &ftrace_enable_fops);
- if (!entry)
- pr_warning("Could not create debugfs "
- "'%s/enable' entry\n", call->name);
+ if (call->regfunc)
+ entry = trace_create_file("enable", 0644, call->dir, call,
+ enable);
+
+ if (call->id && call->profile_enable)
+ entry = trace_create_file("id", 0444, call->dir, call,
+ id);
+
+ if (call->define_fields) {
+ ret = call->define_fields(call);
+ if (ret < 0) {
+ pr_warning("Could not initialize trace point"
+ " events/%s\n", call->name);
+ return ret;
+ }
+ entry = trace_create_file("filter", 0644, call->dir, call,
+ filter);
+ }
+
+ /* A trace may not want to export its format */
+ if (!call->show_format)
+ return 0;
+
+ entry = trace_create_file("format", 0444, call->dir, call,
+ format);
return 0;
}
+#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 void remove_subsystem_dir(const char *name)
+{
+ struct event_subsystem *system;
+
+ if (strcmp(name, TRACE_SYSTEM) == 0)
+ return;
+
+ list_for_each_entry(system, &event_subsystems, list) {
+ if (strcmp(system->name, name) == 0) {
+ if (!--system->nr_events) {
+ struct event_filter *filter = system->filter;
+
+ debugfs_remove_recursive(system->entry);
+ list_del(&system->list);
+ if (filter) {
+ kfree(filter->filter_string);
+ kfree(filter);
+ }
+ kfree(system->name);
+ kfree(system);
+ }
+ break;
+ }
+ }
+}
+
+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;
+ struct dentry *d_events;
+ int ret;
+
+ start = mod->trace_events;
+ end = mod->trace_events + mod->num_trace_events;
+
+ if (start == end)
+ return;
+
+ d_events = event_trace_events_dir();
+ if (!d_events)
+ return;
+
+ for_each_event(call, start, end) {
+ /* The linker may leave blanks */
+ if (!call->name)
+ continue;
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
+ /*
+ * This module has events, create file ops for this module
+ * if not already done.
+ */
+ if (!file_ops) {
+ file_ops = trace_create_file_ops(mod);
+ if (!file_ops)
+ return;
+ }
+ call->mod = mod;
+ list_add(&call->list, &ftrace_events);
+ event_create_dir(call, d_events,
+ &file_ops->id, &file_ops->enable,
+ &file_ops->filter, &file_ops->format);
+ }
+}
+
+static void trace_module_remove_events(struct module *mod)
+{
+ struct ftrace_module_file_ops *file_ops;
+ struct ftrace_event_call *call, *p;
+ bool found = false;
+
+ down_write(&trace_event_mutex);
+ list_for_each_entry_safe(call, p, &ftrace_events, list) {
+ if (call->mod == mod) {
+ found = true;
+ ftrace_event_enable_disable(call, 0);
+ if (call->event)
+ __unregister_ftrace_event(call->event);
+ debugfs_remove_recursive(call->dir);
+ list_del(&call->list);
+ trace_destroy_fields(call);
+ destroy_preds(call);
+ remove_subsystem_dir(call->system);
+ }
+ }
+
+ /* 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);
+ }
+
+ /*
+ * It is safest to reset the ring buffer if the module being unloaded
+ * registered any events.
+ */
+ if (found)
+ tracing_reset_current_online_cpus();
+ up_write(&trace_event_mutex);
+}
+
+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;
+}
+#else
+static int trace_module_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return 0;
+}
+#endif /* CONFIG_MODULES */
+
+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 = 1;
+ tracing_selftest_disabled = 1;
+
+ return 1;
+}
+__setup("trace_event=", setup_trace_event);
+
static __init int event_trace_init(void)
{
- struct ftrace_event_call *call = __start_ftrace_events;
+ struct ftrace_event_call *call;
struct dentry *d_tracer;
struct dentry *entry;
struct dentry *d_events;
+ int ret;
+ char *buf = bootup_event_buf;
+ char *token;
d_tracer = tracing_init_dentry();
if (!d_tracer)
if (!d_events)
return 0;
- events_for_each(call) {
+ /* 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,
+ NULL, &ftrace_system_enable_fops);
+
+ for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
/* The linker may leave blanks */
if (!call->name)
continue;
- event_create_dir(call, d_events);
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
+ list_add(&call->list, &ftrace_events);
+ event_create_dir(call, d_events, &ftrace_event_id_fops,
+ &ftrace_enable_fops, &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ }
+
+ while (true) {
+ token = strsep(&buf, ",");
+
+ if (!token)
+ break;
+ if (!*token)
+ continue;
+
+ ret = ftrace_set_clr_event(token, 1);
+ if (ret)
+ pr_warning("Failed to enable trace event: %s\n", token);
}
+ ret = register_module_notifier(&trace_module_nb);
+ if (ret)
+ pr_warning("Failed to register trace events module notifier\n");
+
return 0;
}
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_event_call *call;
+ struct event_subsystem *system;
+ int ret;
+
+ pr_info("Running tests on trace events:\n");
+
+ list_for_each_entry(call, &ftrace_events, list) {
+
+ /* Only test those that have a regfunc */
+ if (!call->regfunc)
+ 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->system &&
+ strcmp(call->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 (call->enabled) {
+ pr_warning("Enabled event during self test!\n");
+ WARN_ON_ONCE(1);
+ continue;
+ }
+
+ ftrace_event_enable_disable(call, 1);
+ event_test_stuff();
+ ftrace_event_enable_disable(call, 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(system, &event_subsystems, list) {
+
+ /* 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(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(NULL, system->name, NULL, 0);
+ if (WARN_ON_ONCE(ret))
+ pr_warning("error disabling system %s\n",
+ system->name);
+
+ 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(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(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 ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ struct ftrace_entry *entry;
+ unsigned long flags;
+ long disabled;
+ int resched;
+ int cpu;
+ int pc;
+
+ pc = preempt_count();
+ resched = ftrace_preempt_disable();
+ 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_nowake_buffer_unlock_commit(buffer, event, flags, pc);
+
+ out:
+ atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
+ ftrace_preempt_enable(resched);
+}
+
+static struct ftrace_ops trace_ops __initdata =
+{
+ .func = function_test_events_call,
+};
+
+static __init void event_trace_self_test_with_function(void)
+{
+ register_ftrace_function(&trace_ops);
+ 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