ftrace: Add enabled_functions file
Add the enabled_functions file that is used to show all the
functions that have been enabled for tracing as well as their
ref counts. This helps seeing if any function has been registered
and what functions are being traced.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 5dd332cc..065f1e6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1703,6 +1703,7 @@
FTRACE_ITER_NOTRACE = (1 << 1),
FTRACE_ITER_PRINTALL = (1 << 2),
FTRACE_ITER_HASH = (1 << 3),
+ FTRACE_ITER_ENABLED = (1 << 4),
};
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
@@ -1842,7 +1843,11 @@
!(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
((iter->flags & FTRACE_ITER_NOTRACE) &&
- !ftrace_lookup_ip(ops->notrace_hash, rec->ip))) {
+ !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
+
+ ((iter->flags & FTRACE_ITER_ENABLED) &&
+ !(rec->flags & ~FTRACE_FL_MASK))) {
+
rec = NULL;
goto retry;
}
@@ -1944,7 +1949,11 @@
if (!rec)
return 0;
- seq_printf(m, "%ps\n", (void *)rec->ip);
+ seq_printf(m, "%ps", (void *)rec->ip);
+ if (iter->flags & FTRACE_ITER_ENABLED)
+ seq_printf(m, " (%ld)",
+ rec->flags & ~FTRACE_FL_MASK);
+ seq_printf(m, "\n");
return 0;
}
@@ -1983,6 +1992,34 @@
return ret;
}
+static int
+ftrace_enabled_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ iter->pg = ftrace_pages_start;
+ iter->flags = FTRACE_ITER_ENABLED;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+
+ m->private = iter;
+ } else {
+ kfree(iter);
+ }
+
+ return ret;
+}
+
static void ftrace_filter_reset(struct ftrace_hash *hash)
{
mutex_lock(&ftrace_lock);
@@ -2838,6 +2875,13 @@
.release = seq_release_private,
};
+static const struct file_operations ftrace_enabled_fops = {
+ .open = ftrace_enabled_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
static const struct file_operations ftrace_filter_fops = {
.open = ftrace_filter_open,
.read = seq_read,
@@ -3069,6 +3113,9 @@
trace_create_file("available_filter_functions", 0444,
d_tracer, NULL, &ftrace_avail_fops);
+ trace_create_file("enabled_functions", 0444,
+ d_tracer, NULL, &ftrace_enabled_fops);
+
trace_create_file("set_ftrace_filter", 0644, d_tracer,
NULL, &ftrace_filter_fops);