mirror of
https://github.com/torvalds/linux.git
synced 2024-12-06 11:01:43 +00:00
2a6c24afab
While analyzing the code, I discovered that there's a potential race between deleting a trace instance and setting events. There are a few races that can occur if events are being traced as the buffer is being deleted. Mostly the problem comes with freeing the descriptor used by the trace event callback. To prevent problems like this, the events are disabled before the buffer is deleted. The problem with the current solution is that the event_mutex is let go between disabling the events and freeing the files, which means that the events could be enabled again while the freeing takes place. Cc: stable@vger.kernel.org # 3.10 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2767 lines
62 KiB
C
2767 lines
62 KiB
C
/*
|
|
* 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>.
|
|
*
|
|
*/
|
|
|
|
#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/slab.h>
|
|
#include <linux/delay.h>
|
|
|
|
#include <asm/setup.h>
|
|
|
|
#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);
|
|
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;
|
|
|
|
#define SYSTEM_FL_FREE_NAME (1 << 31)
|
|
|
|
static inline int system_refcount(struct event_subsystem *system)
|
|
{
|
|
return system->ref_count & ~SYSTEM_FL_FREE_NAME;
|
|
}
|
|
|
|
static int system_refcount_inc(struct event_subsystem *system)
|
|
{
|
|
return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
|
|
}
|
|
|
|
static int system_refcount_dec(struct event_subsystem *system)
|
|
{
|
|
return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
|
|
}
|
|
|
|
/* 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() \
|
|
}
|
|
|
|
static 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 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 ftrace_event_call *call, char *name)
|
|
{
|
|
struct ftrace_event_field *field;
|
|
struct list_head *head;
|
|
|
|
field = __find_event_field(&ftrace_common_fields, name);
|
|
if (field)
|
|
return field;
|
|
|
|
head = trace_get_fields(call);
|
|
return __find_event_field(head, 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 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;
|
|
}
|
|
|
|
static 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, 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 & 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, else clear it */
|
|
if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
|
|
set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
|
|
else
|
|
clear_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 {
|
|
if (atomic_inc_return(&file->sm_ref) > 1)
|
|
break;
|
|
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_refcount(system) == 0);
|
|
if (system_refcount_dec(system))
|
|
return;
|
|
|
|
list_del(&system->list);
|
|
|
|
if (filter) {
|
|
kfree(filter->filter_string);
|
|
kfree(filter);
|
|
}
|
|
if (system->ref_count & SYSTEM_FL_FREE_NAME)
|
|
kfree(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 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(system_refcount(dir->subsystem) == 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);
|
|
}
|
|
|
|
/*
|
|
* Open and update trace_array ref count.
|
|
* Must have the current trace_array passed to it.
|
|
*/
|
|
static int tracing_open_generic_file(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ftrace_event_file *file = inode->i_private;
|
|
struct trace_array *tr = file->tr;
|
|
int ret;
|
|
|
|
if (trace_array_get(tr) < 0)
|
|
return -ENODEV;
|
|
|
|
ret = tracing_open_generic(inode, filp);
|
|
if (ret < 0)
|
|
trace_array_put(tr);
|
|
return ret;
|
|
}
|
|
|
|
static int tracing_release_generic_file(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ftrace_event_file *file = inode->i_private;
|
|
struct trace_array *tr = file->tr;
|
|
|
|
trace_array_put(tr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* __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 ftrace_event_file *file;
|
|
struct ftrace_event_call *call;
|
|
int ret = -EINVAL;
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
/*
|
|
* 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(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[4] = "0";
|
|
|
|
if (file->flags & FTRACE_EVENT_FL_ENABLED &&
|
|
!(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
|
|
strcpy(buf, "1");
|
|
|
|
if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
|
|
file->flags & FTRACE_EVENT_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 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(&trace_types_lock);
|
|
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);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
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 ftrace_subsystem_dir *dir;
|
|
struct trace_array *tr = inode->i_private;
|
|
int ret;
|
|
|
|
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);
|
|
}
|
|
|
|
filp->private_data = dir;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int subsystem_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_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 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_file,
|
|
.read = event_enable_read,
|
|
.write = event_enable_write,
|
|
.release = tracing_release_generic_file,
|
|
.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;
|
|
|
|
/* Only allocate if dynamic (kprobes and modules) */
|
|
if (!core_kernel_data((unsigned long)name)) {
|
|
system->ref_count |= SYSTEM_FL_FREE_NAME;
|
|
system->name = kstrdup(name, GFP_KERNEL);
|
|
if (!system->name)
|
|
goto out_free;
|
|
} else
|
|
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:
|
|
if (system->ref_count & SYSTEM_FL_FREE_NAME)
|
|
kfree(system->name);
|
|
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;
|
|
}
|
|
|
|
static struct ftrace_event_file *
|
|
trace_create_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 NULL;
|
|
|
|
file->event_call = call;
|
|
file->tr = tr;
|
|
atomic_set(&file->sm_ref, 0);
|
|
list_add(&file->list, &tr->events);
|
|
|
|
return file;
|
|
}
|
|
|
|
/* 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 = trace_create_new_event(call, tr);
|
|
if (!file)
|
|
return -ENOMEM;
|
|
|
|
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 = trace_create_new_event(call, tr);
|
|
if (!file)
|
|
return -ENOMEM;
|
|
|
|
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(&trace_types_lock);
|
|
mutex_lock(&event_mutex);
|
|
|
|
ret = __register_event(call, NULL);
|
|
if (ret >= 0)
|
|
__add_event_to_tracers(call, NULL);
|
|
|
|
mutex_unlock(&event_mutex);
|
|
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 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(&trace_types_lock);
|
|
mutex_lock(&event_mutex);
|
|
down_write(&trace_event_sem);
|
|
__trace_remove_event_call(call);
|
|
up_write(&trace_event_sem);
|
|
mutex_unlock(&event_mutex);
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
#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_sem);
|
|
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_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.
|
|
*/
|
|
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(&trace_types_lock);
|
|
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);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
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 || !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) {
|
|
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, 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 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_sem);
|
|
__trace_add_event_dirs(tr);
|
|
up_write(&trace_event_sem);
|
|
|
|
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_sem);
|
|
__trace_early_add_event_dirs(tr);
|
|
up_write(&trace_event_sem);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int event_trace_del_tracer(struct trace_array *tr)
|
|
{
|
|
mutex_lock(&event_mutex);
|
|
|
|
/* Disable any running events */
|
|
__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
|
|
|
|
down_write(&trace_event_sem);
|
|
__trace_remove_event_dirs(tr);
|
|
debugfs_remove_recursive(tr->event_dir);
|
|
up_write(&trace_event_sem);
|
|
|
|
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
|