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-rw-r--r--kernel/trace/trace_events.c98
1 files changed, 45 insertions, 53 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 7d854290bf81..898f868833f2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -826,59 +826,33 @@ 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 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)
@@ -904,8 +878,7 @@ 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:
@@ -932,6 +905,17 @@ 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;
+
+ while (l < *pos && p)
+ p = f_next(m, p, &l);
+
+ return p;
+}
+
static void f_stop(struct seq_file *m, void *p)
{
}
@@ -963,23 +947,14 @@ 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;
+ char buf[32];
+ int len;
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;
+ len = sprintf(buf, "%d\n", call->event.type);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
}
static ssize_t
@@ -1218,6 +1193,7 @@ 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,
@@ -1245,7 +1221,7 @@ 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 = {
@@ -1323,6 +1299,15 @@ 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 +1321,19 @@ 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 *
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