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Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c292
1 files changed, 169 insertions, 123 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 7d854290bf81..29a7ebcfb426 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -409,33 +409,42 @@ static void put_system(struct ftrace_subsystem_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)
+static void remove_subsystem(struct ftrace_subsystem_dir *dir)
{
- struct ftrace_event_file *file = inode->i_private;
- struct trace_array *tr = file->tr;
- int ret;
+ if (!dir)
+ return;
- if (trace_array_get(tr) < 0)
- return -ENODEV;
+ if (!--dir->nr_events) {
+ debugfs_remove_recursive(dir->entry);
+ list_del(&dir->list);
+ __put_system_dir(dir);
+ }
+}
- ret = tracing_open_generic(inode, filp);
- if (ret < 0)
- trace_array_put(tr);
- return ret;
+static void *event_file_data(struct file *filp)
+{
+ return ACCESS_ONCE(file_inode(filp)->i_private);
}
-static int tracing_release_generic_file(struct inode *inode, struct file *filp)
+static void remove_event_file_dir(struct ftrace_event_file *file)
{
- struct ftrace_event_file *file = inode->i_private;
- struct trace_array *tr = file->tr;
+ struct dentry *dir = file->dir;
+ struct dentry *child;
- trace_array_put(tr);
+ if (dir) {
+ spin_lock(&dir->d_lock); /* probably unneeded */
+ list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+ if (child->d_inode) /* probably unneeded */
+ child->d_inode->i_private = NULL;
+ }
+ spin_unlock(&dir->d_lock);
- return 0;
+ debugfs_remove_recursive(dir);
+ }
+
+ list_del(&file->list);
+ remove_subsystem(file->system);
+ kmem_cache_free(file_cachep, file);
}
/*
@@ -679,15 +688,25 @@ 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;
+ struct ftrace_event_file *file;
+ unsigned long flags;
char buf[4] = "0";
- if (file->flags & FTRACE_EVENT_FL_ENABLED &&
- !(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+ mutex_lock(&event_mutex);
+ file = event_file_data(filp);
+ if (likely(file))
+ flags = file->flags;
+ mutex_unlock(&event_mutex);
+
+ if (!file)
+ return -ENODEV;
+
+ if (flags & FTRACE_EVENT_FL_ENABLED &&
+ !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
strcpy(buf, "1");
- if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
- file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+ if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
+ flags & FTRACE_EVENT_FL_SOFT_MODE)
strcat(buf, "*");
strcat(buf, "\n");
@@ -699,13 +718,10 @@ 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;
+ struct ftrace_event_file *file;
unsigned long val;
int ret;
- if (!file)
- return -EINVAL;
-
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
if (ret)
return ret;
@@ -717,8 +733,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
switch (val) {
case 0:
case 1:
+ ret = -ENODEV;
mutex_lock(&event_mutex);
- ret = ftrace_event_enable_disable(file, val);
+ file = event_file_data(filp);
+ if (likely(file))
+ ret = ftrace_event_enable_disable(file, val);
mutex_unlock(&event_mutex);
break;
@@ -825,65 +844,39 @@ enum {
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 ftrace_event_call *call = event_file_data(m->private);
struct list_head *common_head = &ftrace_common_fields;
struct list_head *head = trace_get_fields(call);
+ struct list_head *node = v;
(*pos)++;
switch ((unsigned long)v) {
case FORMAT_HEADER:
- if (unlikely(list_empty(common_head)))
- return NULL;
-
- field = list_entry(common_head->prev,
- struct ftrace_event_field, link);
- return field;
+ node = common_head;
+ break;
case FORMAT_FIELD_SEPERATOR:
- if (unlikely(list_empty(head)))
- return NULL;
-
- field = list_entry(head->prev, struct ftrace_event_field, link);
- return field;
+ node = head;
+ break;
case FORMAT_PRINTFMT:
/* all done */
return NULL;
}
- field = v;
- if (field->link.prev == common_head)
+ node = node->prev;
+ if (node == common_head)
return (void *)FORMAT_FIELD_SEPERATOR;
- else if (field->link.prev == head)
+ else if (node == 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;
+ else
+ return node;
}
static int f_show(struct seq_file *m, void *v)
{
- struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *call = event_file_data(m->private);
struct ftrace_event_field *field;
const char *array_descriptor;
@@ -904,8 +897,7 @@ static int f_show(struct seq_file *m, void *v)
return 0;
}
- field = v;
-
+ field = list_entry(v, struct ftrace_event_field, link);
/*
* Smartly shows the array type(except dynamic array).
* Normal:
@@ -932,8 +924,25 @@ static int f_show(struct seq_file *m, void *v)
return 0;
}
+static void *f_start(struct seq_file *m, loff_t *pos)
+{
+ void *p = (void *)FORMAT_HEADER;
+ loff_t l = 0;
+
+ /* ->stop() is called even if ->start() fails */
+ mutex_lock(&event_mutex);
+ if (!event_file_data(m->private))
+ return ERR_PTR(-ENODEV);
+
+ while (l < *pos && p)
+ p = f_next(m, p, &l);
+
+ return p;
+}
+
static void f_stop(struct seq_file *m, void *p)
{
+ mutex_unlock(&event_mutex);
}
static const struct seq_operations trace_format_seq_ops = {
@@ -945,7 +954,6 @@ static const struct seq_operations trace_format_seq_ops = {
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;
@@ -954,7 +962,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
return ret;
m = file->private_data;
- m->private = call;
+ m->private = file;
return 0;
}
@@ -962,45 +970,47 @@ static int trace_format_open(struct inode *inode, struct file *file)
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;
+ int id = (long)event_file_data(filp);
+ char buf[32];
+ int len;
if (*ppos)
return 0;
- s = kmalloc(sizeof(*s), GFP_KERNEL);
- if (!s)
- return -ENOMEM;
+ if (unlikely(!id))
+ return -ENODEV;
- trace_seq_init(s);
- trace_seq_printf(s, "%d\n", call->event.type);
+ len = sprintf(buf, "%d\n", id);
- r = simple_read_from_buffer(ubuf, cnt, ppos,
- s->buffer, s->len);
- kfree(s);
- return r;
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
}
static ssize_t
event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- struct ftrace_event_call *call = filp->private_data;
+ struct ftrace_event_call *call;
struct trace_seq *s;
- int r;
+ int r = -ENODEV;
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);
+ mutex_lock(&event_mutex);
+ call = event_file_data(filp);
+ if (call)
+ print_event_filter(call, s);
+ mutex_unlock(&event_mutex);
+
+ if (call)
+ r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
kfree(s);
@@ -1011,9 +1021,9 @@ 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;
+ struct ftrace_event_call *call;
char *buf;
- int err;
+ int err = -ENODEV;
if (cnt >= PAGE_SIZE)
return -EINVAL;
@@ -1028,7 +1038,12 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
}
buf[cnt] = '\0';
- err = apply_event_filter(call, buf);
+ mutex_lock(&event_mutex);
+ call = event_file_data(filp);
+ if (call)
+ err = apply_event_filter(call, buf);
+ mutex_unlock(&event_mutex);
+
free_page((unsigned long) buf);
if (err < 0)
return err;
@@ -1218,6 +1233,7 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
static int ftrace_event_avail_open(struct inode *inode, struct file *file);
static int ftrace_event_set_open(struct inode *inode, struct file *file);
+static int ftrace_event_release(struct inode *inode, struct file *file);
static const struct seq_operations show_event_seq_ops = {
.start = t_start,
@@ -1245,14 +1261,13 @@ static const struct file_operations ftrace_set_event_fops = {
.read = seq_read,
.write = ftrace_event_write,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = ftrace_event_release,
};
static const struct file_operations ftrace_enable_fops = {
- .open = tracing_open_generic_file,
+ .open = tracing_open_generic,
.read = event_enable_read,
.write = event_enable_write,
- .release = tracing_release_generic_file,
.llseek = default_llseek,
};
@@ -1264,7 +1279,6 @@ static const struct file_operations ftrace_event_format_fops = {
};
static const struct file_operations ftrace_event_id_fops = {
- .open = tracing_open_generic,
.read = event_id_read,
.llseek = default_llseek,
};
@@ -1323,6 +1337,15 @@ ftrace_event_open(struct inode *inode, struct file *file,
return ret;
}
+static int ftrace_event_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ return seq_release(inode, file);
+}
+
static int
ftrace_event_avail_open(struct inode *inode, struct file *file)
{
@@ -1336,12 +1359,19 @@ ftrace_event_set_open(struct inode *inode, struct file *file)
{
const struct seq_operations *seq_ops = &show_set_event_seq_ops;
struct trace_array *tr = inode->i_private;
+ int ret;
+
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
ftrace_clear_events(tr);
- return ftrace_event_open(inode, file, seq_ops);
+ ret = ftrace_event_open(inode, file, seq_ops);
+ if (ret < 0)
+ trace_array_put(tr);
+ return ret;
}
static struct event_subsystem *
@@ -1496,8 +1526,8 @@ event_create_dir(struct dentry *parent,
#ifdef CONFIG_PERF_EVENTS
if (call->event.type && call->class->reg)
- trace_create_file("id", 0444, file->dir, call,
- id);
+ trace_create_file("id", 0444, file->dir,
+ (void *)(long)call->event.type, id);
#endif
/*
@@ -1522,33 +1552,16 @@ event_create_dir(struct dentry *parent,
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);
-
+ remove_event_file_dir(file);
/*
* The do_for_each_event_file_safe() is
* a double loop. After finding the call for this
@@ -1700,16 +1713,53 @@ static void __trace_remove_event_call(struct ftrace_event_call *call)
destroy_preds(call);
}
+static int probe_remove_event_call(struct ftrace_event_call *call)
+{
+ struct trace_array *tr;
+ struct ftrace_event_file *file;
+
+#ifdef CONFIG_PERF_EVENTS
+ if (call->perf_refcount)
+ return -EBUSY;
+#endif
+ do_for_each_event_file(tr, file) {
+ if (file->event_call != call)
+ continue;
+ /*
+ * We can't rely on ftrace_event_enable_disable(enable => 0)
+ * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
+ * TRACE_REG_UNREGISTER.
+ */
+ if (file->flags & FTRACE_EVENT_FL_ENABLED)
+ return -EBUSY;
+ /*
+ * The do_for_each_event_file_safe() is
+ * a double loop. After finding the call for this
+ * trace_array, we use break to jump to the next
+ * trace_array.
+ */
+ break;
+ } while_for_each_event_file();
+
+ __trace_remove_event_call(call);
+
+ return 0;
+}
+
/* Remove an event_call */
-void trace_remove_event_call(struct ftrace_event_call *call)
+int trace_remove_event_call(struct ftrace_event_call *call)
{
+ int ret;
+
mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
down_write(&trace_event_sem);
- __trace_remove_event_call(call);
+ ret = probe_remove_event_call(call);
up_write(&trace_event_sem);
mutex_unlock(&event_mutex);
mutex_unlock(&trace_types_lock);
+
+ return ret;
}
#define for_each_event(event, start, end) \
@@ -2278,12 +2328,8 @@ __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);
- }
+ list_for_each_entry_safe(file, next, &tr->events, list)
+ remove_event_file_dir(file);
}
static void