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-rw-r--r--kernel/trace/trace_events.c1397
1 files changed, 1119 insertions, 278 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 57e9b284250c..53582e982e51 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -34,9 +34,27 @@ char event_storage[EVENT_STORAGE_SIZE];
EXPORT_SYMBOL_GPL(event_storage);
LIST_HEAD(ftrace_events);
-LIST_HEAD(ftrace_common_fields);
+static LIST_HEAD(ftrace_common_fields);
-struct list_head *
+#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
+
+static struct kmem_cache *field_cachep;
+static struct kmem_cache *file_cachep;
+
+/* Double loops, do not use break, only goto's work */
+#define do_for_each_event_file(tr, file) \
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
+ list_for_each_entry(file, &tr->events, list)
+
+#define do_for_each_event_file_safe(tr, file) \
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
+ struct ftrace_event_file *___n; \
+ list_for_each_entry_safe(file, ___n, &tr->events, list)
+
+#define while_for_each_event_file() \
+ }
+
+static struct list_head *
trace_get_fields(struct ftrace_event_call *event_call)
{
if (!event_call->class->get_fields)
@@ -44,23 +62,45 @@ trace_get_fields(struct ftrace_event_call *event_call)
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 = kzalloc(sizeof(*field), GFP_KERNEL);
+ field = kmem_cache_alloc(field_cachep, GFP_TRACE);
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;
+ field->name = name;
+ field->type = type;
if (filter_type == FILTER_OTHER)
field->filter_type = filter_assign_type(type);
@@ -76,9 +116,7 @@ static int __trace_define_field(struct list_head *head, const char *type,
return 0;
err:
- if (field)
- kfree(field->name);
- kfree(field);
+ kmem_cache_free(field_cachep, field);
return -ENOMEM;
}
@@ -120,7 +158,7 @@ static int trace_define_common_fields(void)
return ret;
}
-void trace_destroy_fields(struct ftrace_event_call *call)
+static void trace_destroy_fields(struct ftrace_event_call *call)
{
struct ftrace_event_field *field, *next;
struct list_head *head;
@@ -128,9 +166,7 @@ void trace_destroy_fields(struct ftrace_event_call *call)
head = trace_get_fields(call);
list_for_each_entry_safe(field, next, head, link) {
list_del(&field->link);
- kfree(field->type);
- kfree(field->name);
- kfree(field);
+ kmem_cache_free(field_cachep, field);
}
}
@@ -149,15 +185,17 @@ 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,
- call);
+ file);
case TRACE_REG_UNREGISTER:
tracepoint_probe_unregister(call->name,
call->class->probe,
- call);
+ file);
return 0;
#ifdef CONFIG_PERF_EVENTS
@@ -183,54 +221,100 @@ EXPORT_SYMBOL_GPL(ftrace_event_reg);
void trace_event_enable_cmd_record(bool enable)
{
- struct ftrace_event_call *call;
+ struct ftrace_event_file *file;
+ struct trace_array *tr;
mutex_lock(&event_mutex);
- list_for_each_entry(call, &ftrace_events, list) {
- if (!(call->flags & TRACE_EVENT_FL_ENABLED))
+ do_for_each_event_file(tr, file) {
+
+ if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
continue;
if (enable) {
tracing_start_cmdline_record();
- call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
+ set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
} else {
tracing_stop_cmdline_record();
- call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
+ 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_call *call,
- int enable)
+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:
- if (call->flags & TRACE_EVENT_FL_ENABLED) {
- call->flags &= ~TRACE_EVENT_FL_ENABLED;
- if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
+ /*
+ * When soft_disable is set and enable is cleared, we want
+ * to clear the SOFT_DISABLED flag but leave the event in the
+ * state that it was. That is, if the event was enabled and
+ * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
+ * is set we do not want the event to be enabled before we
+ * clear the bit.
+ *
+ * When soft_disable is not set but the SOFT_MODE flag is,
+ * we do nothing. Do not disable the tracepoint, otherwise
+ * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
+ */
+ if (soft_disable) {
+ disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
+ clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
+ } else
+ disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
+
+ if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
+ clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
+ if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
tracing_stop_cmdline_record();
- call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
+ clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
}
- call->class->reg(call, TRACE_REG_UNREGISTER, NULL);
+ call->class->reg(call, TRACE_REG_UNREGISTER, file);
}
+ /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */
+ if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
break;
case 1:
- if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
+ /*
+ * When soft_disable is set and enable is set, we want to
+ * register the tracepoint for the event, but leave the event
+ * as is. That means, if the event was already enabled, we do
+ * nothing (but set SOFT_MODE). If the event is disabled, we
+ * set SOFT_DISABLED before enabling the event tracepoint, so
+ * it still seems to be disabled.
+ */
+ if (!soft_disable)
+ clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
+ else
+ set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
+
+ if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
+
+ /* Keep the event disabled, when going to SOFT_MODE. */
+ if (soft_disable)
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
+
if (trace_flags & TRACE_ITER_RECORD_CMD) {
tracing_start_cmdline_record();
- call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
+ set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
}
- ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);
+ 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;
}
- call->flags |= TRACE_EVENT_FL_ENABLED;
+ set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
+
+ /* WAS_ENABLED gets set but never cleared. */
+ call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
}
break;
}
@@ -238,13 +322,19 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call,
return ret;
}
-static void ftrace_clear_events(void)
+static int ftrace_event_enable_disable(struct ftrace_event_file *file,
+ int enable)
{
- struct ftrace_event_call *call;
+ 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(call, &ftrace_events, list) {
- ftrace_event_enable_disable(call, 0);
+ list_for_each_entry(file, &tr->events, list) {
+ ftrace_event_enable_disable(file, 0);
}
mutex_unlock(&event_mutex);
}
@@ -257,11 +347,12 @@ static void __put_system(struct event_subsystem *system)
if (--system->ref_count)
return;
+ list_del(&system->list);
+
if (filter) {
kfree(filter->filter_string);
kfree(filter);
}
- kfree(system->name);
kfree(system);
}
@@ -271,24 +362,45 @@ static void __get_system(struct event_subsystem *system)
system->ref_count++;
}
-static void put_system(struct event_subsystem *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(dir->subsystem->ref_count == 1 && dir->ref_count != 1);
+
+ __put_system(dir->subsystem);
+ if (!--dir->ref_count)
+ kfree(dir);
+}
+
+static void put_system(struct ftrace_subsystem_dir *dir)
{
mutex_lock(&event_mutex);
- __put_system(system);
+ __put_system_dir(dir);
mutex_unlock(&event_mutex);
}
/*
* __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
*/
-static int __ftrace_set_clr_event(const char *match, const char *sub,
- const char *event, int set)
+static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
+ const char *sub, const char *event, int set)
{
+ struct ftrace_event_file *file;
struct ftrace_event_call *call;
int ret = -EINVAL;
mutex_lock(&event_mutex);
- list_for_each_entry(call, &ftrace_events, list) {
+ list_for_each_entry(file, &tr->events, list) {
+
+ call = file->event_call;
if (!call->name || !call->class || !call->class->reg)
continue;
@@ -307,7 +419,7 @@ static int __ftrace_set_clr_event(const char *match, const char *sub,
if (event && strcmp(event, call->name) != 0)
continue;
- ftrace_event_enable_disable(call, set);
+ ftrace_event_enable_disable(file, set);
ret = 0;
}
@@ -316,7 +428,7 @@ static int __ftrace_set_clr_event(const char *match, const char *sub,
return ret;
}
-static int ftrace_set_clr_event(char *buf, int set)
+static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
{
char *event = NULL, *sub = NULL, *match;
@@ -344,7 +456,7 @@ static int ftrace_set_clr_event(char *buf, int set)
event = NULL;
}
- return __ftrace_set_clr_event(match, sub, event, set);
+ return __ftrace_set_clr_event(tr, match, sub, event, set);
}
/**
@@ -361,7 +473,9 @@ static int ftrace_set_clr_event(char *buf, int set)
*/
int trace_set_clr_event(const char *system, const char *event, int set)
{
- return __ftrace_set_clr_event(NULL, system, event, 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);
@@ -373,6 +487,8 @@ 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)
@@ -395,7 +511,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
parser.buffer[parser.idx] = 0;
- ret = ftrace_set_clr_event(parser.buffer + !set, set);
+ ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
if (ret)
goto out_put;
}
@@ -411,17 +527,20 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = v;
+ struct ftrace_event_file *file = v;
+ struct ftrace_event_call *call;
+ struct trace_array *tr = m->private;
(*pos)++;
- list_for_each_entry_continue(call, &ftrace_events, list) {
+ 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 call;
+ return file;
}
return NULL;
@@ -429,30 +548,32 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
static void *t_start(struct seq_file *m, loff_t *pos)
{
- struct ftrace_event_call *call;
+ struct ftrace_event_file *file;
+ struct trace_array *tr = m->private;
loff_t l;
mutex_lock(&event_mutex);
- call = list_entry(&ftrace_events, struct ftrace_event_call, list);
+ file = list_entry(&tr->events, struct ftrace_event_file, list);
for (l = 0; l <= *pos; ) {
- call = t_next(m, call, &l);
- if (!call)
+ file = t_next(m, file, &l);
+ if (!file)
break;
}
- return call;
+ return file;
}
static void *
s_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = v;
+ struct ftrace_event_file *file = v;
+ struct trace_array *tr = m->private;
(*pos)++;
- list_for_each_entry_continue(call, &ftrace_events, list) {
- if (call->flags & TRACE_EVENT_FL_ENABLED)
- return call;
+ list_for_each_entry_continue(file, &tr->events, list) {
+ if (file->flags & FTRACE_EVENT_FL_ENABLED)
+ return file;
}
return NULL;
@@ -460,23 +581,25 @@ s_next(struct seq_file *m, void *v, loff_t *pos)
static void *s_start(struct seq_file *m, loff_t *pos)
{
- struct ftrace_event_call *call;
+ struct ftrace_event_file *file;
+ struct trace_array *tr = m->private;
loff_t l;
mutex_lock(&event_mutex);
- call = list_entry(&ftrace_events, struct ftrace_event_call, list);
+ file = list_entry(&tr->events, struct ftrace_event_file, list);
for (l = 0; l <= *pos; ) {
- call = s_next(m, call, &l);
- if (!call)
+ file = s_next(m, file, &l);
+ if (!file)
break;
}
- return call;
+ return file;
}
static int t_show(struct seq_file *m, void *v)
{
- struct ftrace_event_call *call = 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);
@@ -494,25 +617,31 @@ static ssize_t
event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct ftrace_event_call *call = filp->private_data;
+ struct ftrace_event_file *file = filp->private_data;
char *buf;
- if (call->flags & TRACE_EVENT_FL_ENABLED)
- buf = "1\n";
- else
+ if (file->flags & FTRACE_EVENT_FL_ENABLED) {
+ if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ buf = "0*\n";
+ else
+ buf = "1\n";
+ } else
buf = "0\n";
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+ 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_call *call = filp->private_data;
+ 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;
@@ -525,7 +654,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
case 0:
case 1:
mutex_lock(&event_mutex);
- ret = ftrace_event_enable_disable(call, val);
+ ret = ftrace_event_enable_disable(file, val);
mutex_unlock(&event_mutex);
break;
@@ -543,14 +672,18 @@ 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 event_subsystem *system = filp->private_data;
+ 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(call, &ftrace_events, list) {
+ list_for_each_entry(file, &tr->events, list) {
+ call = file->event_call;
if (!call->name || !call->class || !call->class->reg)
continue;
@@ -562,7 +695,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
* or if all events or cleared, or if we have
* a mixture.
*/
- set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
+ set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
/*
* If we have a mixture, no need to look further.
@@ -584,7 +717,8 @@ static ssize_t
system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct event_subsystem *system = filp->private_data;
+ struct ftrace_subsystem_dir *dir = filp->private_data;
+ struct event_subsystem *system = dir->subsystem;
const char *name = NULL;
unsigned long val;
ssize_t ret;
@@ -607,7 +741,7 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (system)
name = system->name;
- ret = __ftrace_set_clr_event(NULL, name, NULL, val);
+ ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
if (ret)
goto out;
@@ -845,43 +979,75 @@ 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;
- if (!inode->i_private)
- goto skip_search;
-
/* Make sure the system still exists */
mutex_lock(&event_mutex);
- list_for_each_entry(system, &event_subsystems, list) {
- if (system == inode->i_private) {
- /* Don't open systems with no events */
- if (!system->nr_events) {
- system = NULL;
- break;
+ 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;
}
- __get_system(system);
- break;
}
}
+ exit_loop:
mutex_unlock(&event_mutex);
- if (system != inode->i_private)
+ if (!system)
return -ENODEV;
- skip_search:
+ /* Some versions of gcc think dir can be uninitialized here */
+ WARN_ON(!dir);
+
ret = tracing_open_generic(inode, filp);
- if (ret < 0 && system)
- put_system(system);
+ if (ret < 0)
+ put_system(dir);
+
+ return ret;
+}
+
+static int system_tr_open(struct inode *inode, struct file *filp)
+{
+ struct ftrace_subsystem_dir *dir;
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ /* Make a temporary dir that has no system but points to tr */
+ dir = kzalloc(sizeof(*dir), GFP_KERNEL);
+ if (!dir)
+ return -ENOMEM;
+
+ dir->tr = tr;
+
+ ret = tracing_open_generic(inode, filp);
+ if (ret < 0)
+ kfree(dir);
+
+ filp->private_data = dir;
return ret;
}
static int subsystem_release(struct inode *inode, struct file *file)
{
- struct event_subsystem *system = inode->i_private;
+ struct ftrace_subsystem_dir *dir = file->private_data;
- if (system)
- put_system(system);
+ /*
+ * 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;
}
@@ -890,7 +1056,8 @@ 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 ftrace_subsystem_dir *dir = filp->private_data;
+ struct event_subsystem *system = dir->subsystem;
struct trace_seq *s;
int r;
@@ -915,7 +1082,7 @@ 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;
+ struct ftrace_subsystem_dir *dir = filp->private_data;
char *buf;
int err;
@@ -932,7 +1099,7 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
}
buf[cnt] = '\0';
- err = apply_subsystem_event_filter(system, buf);
+ err = apply_subsystem_event_filter(dir, buf);
free_page((unsigned long) buf);
if (err < 0)
return err;
@@ -1041,30 +1208,35 @@ static const struct file_operations ftrace_system_enable_fops = {
.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 struct dentry *event_trace_events_dir(void)
+static int
+ftrace_event_open(struct inode *inode, struct file *file,
+ const struct seq_operations *seq_ops)
{
- static struct dentry *d_tracer;
- static struct dentry *d_events;
-
- if (d_events)
- return d_events;
-
- d_tracer = tracing_init_dentry();
- if (!d_tracer)
- return NULL;
+ struct seq_file *m;
+ int ret;
- d_events = debugfs_create_dir("events", d_tracer);
- if (!d_events)
- pr_warning("Could not create debugfs "
- "'events' directory\n");
+ 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 d_events;
+ return ret;
}
static int
@@ -1072,117 +1244,165 @@ ftrace_event_avail_open(struct inode *inode, struct file *file)
{
const struct seq_operations *seq_ops = &show_event_seq_ops;
- return seq_open(file, 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();
+ ftrace_clear_events(tr);
- return seq_open(file, seq_ops);
+ return ftrace_event_open(inode, file, seq_ops);
+}
+
+static struct event_subsystem *
+create_new_subsystem(const char *name)
+{
+ struct event_subsystem *system;
+
+ /* need to create new entry */
+ system = kmalloc(sizeof(*system), GFP_KERNEL);
+ if (!system)
+ return NULL;
+
+ system->ref_count = 1;
+ system->name = name;
+
+ system->filter = NULL;
+
+ system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
+ if (!system->filter)
+ goto out_free;
+
+ list_add(&system->list, &event_subsystems);
+
+ return system;
+
+ out_free:
+ kfree(system);
+ return NULL;
}
static struct dentry *
-event_subsystem_dir(const char *name, struct dentry *d_events)
+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(system, &event_subsystems, list) {
+ list_for_each_entry(dir, &tr->systems, list) {
+ system = dir->subsystem;
if (strcmp(system->name, name) == 0) {
- system->nr_events++;
- return system->entry;
+ dir->nr_events++;
+ file->system = dir;
+ return dir->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;
+ /* 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;
- 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;
- }
+ dir = kmalloc(sizeof(*dir), GFP_KERNEL);
+ if (!dir)
+ goto out_fail;
- system->nr_events = 1;
- system->ref_count = 1;
- system->name = kstrdup(name, GFP_KERNEL);
- if (!system->name) {
- debugfs_remove(system->entry);
- kfree(system);
- return d_events;
+ 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;
}
- 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;
- }
+ dir->tr = tr;
+ dir->ref_count = 1;
+ dir->nr_events = 1;
+ dir->subsystem = system;
+ file->system = dir;
- entry = debugfs_create_file("filter", 0644, system->entry, system,
+ 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);
+ pr_warning("Could not create debugfs '%s/filter' entry\n", name);
}
- trace_create_file("enable", 0644, system->entry, system,
+ trace_create_file("enable", 0644, dir->entry, dir,
&ftrace_system_enable_fops);
- return system->entry;
+ 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 ftrace_event_call *call, struct dentry *d_events,
+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(call->class->system, d_events);
-
- call->dir = debugfs_create_dir(call->name, d_events);
- if (!call->dir) {
- pr_warning("Could not create debugfs "
- "'%s' directory\n", call->name);
+ 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, call->dir, call,
+ 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, call->dir, call,
+ trace_create_file("id", 0444, file->dir, call,
id);
#endif
@@ -1196,23 +1416,76 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
if (ret < 0) {
pr_warning("Could not initialize trace point"
" events/%s\n", call->name);
- return ret;
+ return -1;
}
}
- trace_create_file("filter", 0644, call->dir, call,
+ trace_create_file("filter", 0644, file->dir, call,
filter);
- trace_create_file("format", 0444, call->dir, call,
+ 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)
{
- ftrace_event_enable_disable(call, 0);
+ 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);
}
@@ -1234,82 +1507,99 @@ static int event_init(struct ftrace_event_call *call)
}
static int
-__trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
- const struct file_operations *id,
- const struct file_operations *enable,
- const struct file_operations *filter,
- const struct file_operations *format)
+__register_event(struct ftrace_event_call *call, struct module *mod)
{
- struct dentry *d_events;
int ret;
ret = event_init(call);
if (ret < 0)
return ret;
- d_events = event_trace_events_dir();
- if (!d_events)
- return -ENOENT;
-
- ret = event_create_dir(call, d_events, id, enable, filter, format);
- if (!ret)
- list_add(&call->list, &ftrace_events);
+ list_add(&call->list, &ftrace_events);
call->mod = mod;
- return ret;
+ return 0;
+}
+
+/* Add an event to a trace directory */
+static int
+__trace_add_new_event(struct ftrace_event_call *call,
+ struct trace_array *tr,
+ const struct file_operations *id,
+ const struct file_operations *enable,
+ const struct file_operations *filter,
+ const struct file_operations *format)
+{
+ struct ftrace_event_file *file;
+
+ file = kmem_cache_alloc(file_cachep, GFP_TRACE);
+ if (!file)
+ return -ENOMEM;
+
+ file->event_call = call;
+ file->tr = tr;
+ list_add(&file->list, &tr->events);
+
+ return event_create_dir(tr->event_dir, file, id, enable, filter, format);
}
+/*
+ * Just create a decriptor for early init. A descriptor is required
+ * for enabling events at boot. We want to enable events before
+ * the filesystem is initialized.
+ */
+static __init int
+__trace_early_add_new_event(struct ftrace_event_call *call,
+ struct trace_array *tr)
+{
+ struct ftrace_event_file *file;
+
+ file = kmem_cache_alloc(file_cachep, GFP_TRACE);
+ if (!file)
+ return -ENOMEM;
+
+ file->event_call = call;
+ file->tr = tr;
+ list_add(&file->list, &tr->events);
+
+ return 0;
+}
+
+struct ftrace_module_file_ops;
+static void __add_event_to_tracers(struct ftrace_event_call *call,
+ struct ftrace_module_file_ops *file_ops);
+
/* Add an additional event_call dynamically */
int trace_add_event_call(struct ftrace_event_call *call)
{
int ret;
mutex_lock(&event_mutex);
- ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
- &ftrace_enable_fops,
- &ftrace_event_filter_fops,
- &ftrace_event_format_fops);
- mutex_unlock(&event_mutex);
- return ret;
-}
-static void remove_subsystem_dir(const char *name)
-{
- struct event_subsystem *system;
-
- if (strcmp(name, TRACE_SYSTEM) == 0)
- return;
+ ret = __register_event(call, NULL);
+ if (ret >= 0)
+ __add_event_to_tracers(call, NULL);
- list_for_each_entry(system, &event_subsystems, list) {
- if (strcmp(system->name, name) == 0) {
- if (!--system->nr_events) {
- debugfs_remove_recursive(system->entry);
- list_del(&system->list);
- __put_system(system);
- }
- break;
- }
- }
+ mutex_unlock(&event_mutex);
+ return ret;
}
/*
- * Must be called under locking both of event_mutex and trace_event_mutex.
+ * Must be called under locking both of 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);
- debugfs_remove_recursive(call->dir);
- remove_subsystem_dir(call->class->system);
}
/* Remove an event_call */
void trace_remove_event_call(struct ftrace_event_call *call)
{
mutex_lock(&event_mutex);
- down_write(&trace_event_mutex);
+ down_write(&trace_event_sem);
__trace_remove_event_call(call);
- up_write(&trace_event_mutex);
+ up_write(&trace_event_sem);
mutex_unlock(&event_mutex);
}
@@ -1336,6 +1626,26 @@ struct ftrace_module_file_ops {
};
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;
@@ -1386,9 +1696,8 @@ static void trace_module_add_events(struct module *mod)
return;
for_each_event(call, start, end) {
- __trace_add_event_call(*call, mod,
- &file_ops->id, &file_ops->enable,
- &file_ops->filter, &file_ops->format);
+ __register_event(*call, mod);
+ __add_event_to_tracers(*call, file_ops);
}
}
@@ -1396,12 +1705,13 @@ 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;
+ bool clear_trace = false;
- down_write(&trace_event_mutex);
+ down_write(&trace_event_sem);
list_for_each_entry_safe(call, p, &ftrace_events, list) {
if (call->mod == mod) {
- found = true;
+ if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
+ clear_trace = true;
__trace_remove_event_call(call);
}
}
@@ -1415,14 +1725,18 @@ static void trace_module_remove_events(struct module *mod)
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.
+ * 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 (found)
- tracing_reset_current_online_cpus();
- up_write(&trace_event_mutex);
+ if (clear_trace)
+ tracing_reset_all_online_cpus();
}
static int trace_module_notify(struct notifier_block *self,
@@ -1443,14 +1757,433 @@ static int trace_module_notify(struct notifier_block *self,
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 int trace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
+static inline struct ftrace_module_file_ops *
+find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
+{
+ return NULL;
+}
+static inline int trace_module_notify(struct notifier_block *self,
+ unsigned long val, void *data)
{
return 0;
}
+static inline int
+__trace_add_new_mod_event(struct ftrace_event_call *call,
+ struct trace_array *tr,
+ struct ftrace_module_file_ops *file_ops)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_MODULES */
+/* Create a new event directory structure for a trace directory. */
+static void
+__trace_add_event_dirs(struct trace_array *tr)
+{
+ struct ftrace_module_file_ops *file_ops = NULL;
+ struct ftrace_event_call *call;
+ int ret;
+
+ list_for_each_entry(call, &ftrace_events, list) {
+ if (call->mod) {
+ /*
+ * Directories for events by modules need to
+ * keep module ref counts when opened (as we don't
+ * want the module to disappear when reading one
+ * of these files). The file_ops keep account of
+ * the module ref count.
+ */
+ file_ops = find_ftrace_file_ops(file_ops, call->mod);
+ if (!file_ops)
+ continue; /* Warn? */
+ ret = __trace_add_new_mod_event(call, tr, file_ops);
+ if (ret < 0)
+ pr_warning("Could not create directory for event %s\n",
+ call->name);
+ continue;
+ }
+ ret = __trace_add_new_event(call, tr,
+ &ftrace_event_id_fops,
+ &ftrace_enable_fops,
+ &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ if (ret < 0)
+ pr_warning("Could not create directory for event %s\n",
+ call->name);
+ }
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+/* Avoid typos */
+#define ENABLE_EVENT_STR "enable_event"
+#define DISABLE_EVENT_STR "disable_event"
+
+struct event_probe_data {
+ struct ftrace_event_file *file;
+ unsigned long count;
+ int ref;
+ bool enable;
+};
+
+static struct ftrace_event_file *
+find_event_file(struct trace_array *tr, const char *system, const char *event)
+{
+ struct ftrace_event_file *file;
+ struct ftrace_event_call *call;
+
+ list_for_each_entry(file, &tr->events, list) {
+
+ call = file->event_call;
+
+ if (!call->name || !call->class || !call->class->reg)
+ continue;
+
+ if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
+ continue;
+
+ if (strcmp(event, call->name) == 0 &&
+ strcmp(system, call->class->system) == 0)
+ return file;
+ }
+ return NULL;
+}
+
+static void
+event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (!data)
+ return;
+
+ if (data->enable)
+ clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
+ else
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
+}
+
+static void
+event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (!data)
+ return;
+
+ if (!data->count)
+ return;
+
+ /* Skip if the event is in a state we want to switch to */
+ if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+ return;
+
+ if (data->count != -1)
+ (data->count)--;
+
+ event_enable_probe(ip, parent_ip, _data);
+}
+
+static int
+event_enable_print(struct seq_file *m, unsigned long ip,
+ struct ftrace_probe_ops *ops, void *_data)
+{
+ struct event_probe_data *data = _data;
+
+ seq_printf(m, "%ps:", (void *)ip);
+
+ seq_printf(m, "%s:%s:%s",
+ data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
+ data->file->event_call->class->system,
+ data->file->event_call->name);
+
+ if (data->count == -1)
+ seq_printf(m, ":unlimited\n");
+ else
+ seq_printf(m, ":count=%ld\n", data->count);
+
+ return 0;
+}
+
+static int
+event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
+ void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ data->ref++;
+ return 0;
+}
+
+static void
+event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
+ void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (WARN_ON_ONCE(data->ref <= 0))
+ return;
+
+ data->ref--;
+ if (!data->ref) {
+ /* Remove the SOFT_MODE flag */
+ __ftrace_event_enable_disable(data->file, 0, 1);
+ module_put(data->file->event_call->mod);
+ kfree(data);
+ }
+ *pdata = NULL;
+}
+
+static struct ftrace_probe_ops event_enable_probe_ops = {
+ .func = event_enable_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_enable_count_probe_ops = {
+ .func = event_enable_count_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_disable_probe_ops = {
+ .func = event_enable_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_disable_count_probe_ops = {
+ .func = event_enable_count_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static int
+event_enable_func(struct ftrace_hash *hash,
+ char *glob, char *cmd, char *param, int enabled)
+{
+ struct trace_array *tr = top_trace_array();
+ struct ftrace_event_file *file;
+ struct ftrace_probe_ops *ops;
+ struct event_probe_data *data;
+ const char *system;
+ const char *event;
+ char *number;
+ bool enable;
+ int ret;
+
+ /* hash funcs only work with set_ftrace_filter */
+ if (!enabled)
+ return -EINVAL;
+
+ if (!param)
+ return -EINVAL;
+
+ system = strsep(&param, ":");
+ if (!param)
+ return -EINVAL;
+
+ event = strsep(&param, ":");
+
+ 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(&param, ":");
+
+ ret = -EINVAL;
+ if (!strlen(number))
+ goto out_free;
+
+ /*
+ * We use the callback data field (which is a pointer)
+ * as our counter.
+ */
+ ret = kstrtoul(number, 0, &data->count);
+ if (ret)
+ goto out_free;
+
+ out_reg:
+ /* Don't let event modules unload while probe registered */
+ ret = try_module_get(file->event_call->mod);
+ if (!ret)
+ goto out_free;
+
+ ret = __ftrace_event_enable_disable(file, 1, 1);
+ if (ret < 0)
+ goto out_put;
+ ret = register_ftrace_function_probe(glob, ops, data);
+ if (!ret)
+ goto out_disable;
+ out:
+ mutex_unlock(&event_mutex);
+ return ret;
+
+ out_disable:
+ __ftrace_event_enable_disable(file, 0, 1);
+ out_put:
+ module_put(file->event_call->mod);
+ out_free:
+ kfree(data);
+ goto out;
+}
+
+static struct ftrace_func_command event_enable_cmd = {
+ .name = ENABLE_EVENT_STR,
+ .func = event_enable_func,
+};
+
+static struct ftrace_func_command event_disable_cmd = {
+ .name = DISABLE_EVENT_STR,
+ .func = event_enable_func,
+};
+
+static __init int register_event_cmds(void)
+{
+ int ret;
+
+ ret = register_ftrace_command(&event_enable_cmd);
+ if (WARN_ON(ret < 0))
+ return ret;
+ ret = register_ftrace_command(&event_disable_cmd);
+ if (WARN_ON(ret < 0))
+ unregister_ftrace_command(&event_enable_cmd);
+ return ret;
+}
+#else
+static inline int register_event_cmds(void) { return 0; }
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * The top level array has already had its ftrace_event_file
+ * descriptors created in order to allow for early events to
+ * be recorded. This function is called after the debugfs has been
+ * initialized, and we now have to create the files associated
+ * to the events.
+ */
+static __init void
+__trace_early_add_event_dirs(struct trace_array *tr)
+{
+ struct ftrace_event_file *file;
+ int ret;
+
+
+ list_for_each_entry(file, &tr->events, list) {
+ ret = event_create_dir(tr->event_dir, file,
+ &ftrace_event_id_fops,
+ &ftrace_enable_fops,
+ &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ if (ret < 0)
+ pr_warning("Could not create directory for event %s\n",
+ file->event_call->name);
+ }
+}
+
+/*
+ * For early boot up, the top trace array requires to have
+ * a list of events that can be enabled. This must be done before
+ * the filesystem is set up in order to allow events to be traced
+ * early.
+ */
+static __init void
+__trace_early_add_events(struct trace_array *tr)
+{
+ struct ftrace_event_call *call;
+ int ret;
+
+ list_for_each_entry(call, &ftrace_events, list) {
+ /* Early boot up should not have any modules loaded */
+ if (WARN_ON_ONCE(call->mod))
+ continue;
+
+ ret = __trace_early_add_new_event(call, tr);
+ if (ret < 0)
+ pr_warning("Could not create early event %s\n",
+ call->name);
+ }
+}
+
+/* Remove the event directory structure for a trace directory. */
+static void
+__trace_remove_event_dirs(struct trace_array *tr)
+{
+ struct ftrace_event_file *file, *next;
+
+ list_for_each_entry_safe(file, next, &tr->events, list) {
+ list_del(&file->list);
+ debugfs_remove_recursive(file->dir);
+ remove_subsystem(file->system);
+ kmem_cache_free(file_cachep, file);
+ }
+}
+
+static void
+__add_event_to_tracers(struct ftrace_event_call *call,
+ struct ftrace_module_file_ops *file_ops)
+{
+ struct trace_array *tr;
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (file_ops)
+ __trace_add_new_mod_event(call, tr, file_ops);
+ else
+ __trace_add_new_event(call, tr,
+ &ftrace_event_id_fops,
+ &ftrace_enable_fops,
+ &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ }
+}
+
static struct notifier_block trace_module_nb = {
.notifier_call = trace_module_notify,
.priority = 0,
@@ -1464,15 +2197,135 @@ 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;
+ 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)
+{
+ /* Disable any running events */
+ __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
+
+ mutex_lock(&event_mutex);
+
+ 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;
@@ -1486,6 +2339,14 @@ static __init int event_trace_enable(void)
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, ",");
@@ -1494,73 +2355,43 @@ static __init int event_trace_enable(void)
if (!*token)
continue;
- ret = ftrace_set_clr_event(token, 1);
+ 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 ftrace_event_call *call;
+ struct trace_array *tr;
struct dentry *d_tracer;
struct dentry *entry;
- struct dentry *d_events;
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,
- NULL, &ftrace_avail_fops);
+ tr, &ftrace_avail_fops);
if (!entry)
pr_warning("Could not create debugfs "
"'available_events' entry\n");
- entry = debugfs_create_file("set_event", 0644, d_tracer,
- NULL, &ftrace_set_event_fops);
- if (!entry)
- pr_warning("Could not create debugfs "
- "'set_event' entry\n");
-
- d_events = event_trace_events_dir();
- if (!d_events)
- return 0;
-
- /* 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);
-
if (trace_define_common_fields())
pr_warning("tracing: Failed to allocate common fields");
- /*
- * Early initialization already enabled ftrace event.
- * Now it's only necessary to create the event directory.
- */
- list_for_each_entry(call, &ftrace_events, list) {
-
- ret = event_create_dir(call, d_events,
- &ftrace_event_id_fops,
- &ftrace_enable_fops,
- &ftrace_event_filter_fops,
- &ftrace_event_format_fops);
- if (ret < 0)
- event_remove(call);
- }
+ ret = early_event_add_tracer(d_tracer, tr);
+ if (ret)
+ return ret;
ret = register_module_notifier(&trace_module_nb);
if (ret)
@@ -1568,6 +2399,7 @@ static __init int event_trace_init(void)
return 0;
}
+early_initcall(event_trace_memsetup);
core_initcall(event_trace_enable);
fs_initcall(event_trace_init);
@@ -1627,13 +2459,20 @@ static __init void event_test_stuff(void)
*/
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(call, &ftrace_events, list) {
+ 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)
@@ -1657,15 +2496,15 @@ static __init void event_trace_self_tests(void)
* If an event is already enabled, someone is using
* it and the self test should not be on.
*/
- if (call->flags & TRACE_EVENT_FL_ENABLED) {
+ if (file->flags & FTRACE_EVENT_FL_ENABLED) {
pr_warning("Enabled event during self test!\n");
WARN_ON_ONCE(1);
continue;
}
- ftrace_event_enable_disable(call, 1);
+ ftrace_event_enable_disable(file, 1);
event_test_stuff();
- ftrace_event_enable_disable(call, 0);
+ ftrace_event_enable_disable(file, 0);
pr_cont("OK\n");
}
@@ -1674,7 +2513,9 @@ static __init void event_trace_self_tests(void)
pr_info("Running tests on trace event systems:\n");
- list_for_each_entry(system, &event_subsystems, list) {
+ list_for_each_entry(dir, &tr->systems, list) {
+
+ system = dir->subsystem;
/* the ftrace system is special, skip it */
if (strcmp(system->name, "ftrace") == 0)
@@ -1682,7 +2523,7 @@ static __init void event_trace_self_tests(void)
pr_info("Testing event system %s: ", system->name);
- ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
+ 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);
@@ -1691,7 +2532,7 @@ static __init void event_trace_self_tests(void)
event_test_stuff();
- ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
+ 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);
@@ -1706,7 +2547,7 @@ static __init void event_trace_self_tests(void)
pr_info("Running tests on all trace events:\n");
pr_info("Testing all events: ");
- ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
+ ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
if (WARN_ON_ONCE(ret)) {
pr_warning("error enabling all events\n");
return;
@@ -1715,7 +2556,7 @@ static __init void event_trace_self_tests(void)
event_test_stuff();
/* reset sysname */
- ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
+ ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
if (WARN_ON_ONCE(ret)) {
pr_warning("error disabling all events\n");
return;