1 files changed, 39 insertions, 1 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a8929e4c77c1..ad568c742bfc 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -768,6 +768,7 @@ enum {
         FTRACE_ITER_FILTER      = (1 << 0),
         FTRACE_ITER_CONT        = (1 << 1),
         FTRACE_ITER_NOTRACE     = (1 << 2),
+        FTRACE_ITER_FAILURES    = (1 << 3),
 };
 
 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
@@ -799,9 +800,16 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                 }
         } else {
                 rec = &iter->pg->records[iter->idx++];
-                if ((rec->flags & FTRACE_FL_FAILED) ||
+                if ((!(iter->flags & FTRACE_ITER_FAILURES) &&
+                     (rec->flags & FTRACE_FL_FAILED)) ||
+
+                    ((iter->flags & FTRACE_ITER_FAILURES) &&
+                     (!(rec->flags & FTRACE_FL_FAILED) ||
+                      (rec->flags & FTRACE_FL_FREE))) ||
+
                     ((iter->flags & FTRACE_ITER_FILTER) &&
                      !(rec->flags & FTRACE_FL_FILTER)) ||
+
                     ((iter->flags & FTRACE_ITER_NOTRACE) &&
                      !(rec->flags & FTRACE_FL_NOTRACE))) {
                         rec = NULL;
@@ -896,6 +904,24 @@ int ftrace_avail_release(struct inode *inode, struct file *file)
         return 0;
 }
 
+static int
+ftrace_failures_open(struct inode *inode, struct file *file)
+{
+        int ret;
+        struct seq_file *m;
+        struct ftrace_iterator *iter;
+
+        ret = ftrace_avail_open(inode, file);
+        if (!ret) {
+                m = (struct seq_file *)file->private_data;
+                iter = (struct ftrace_iterator *)m->private;
+                iter->flags = FTRACE_ITER_FAILURES;
+        }
+
+        return ret;
+}
+
+
 static void ftrace_filter_reset(int enable)
 {
         struct ftrace_page *pg;
@@ -1309,6 +1335,13 @@ static struct file_operations ftrace_avail_fops = {
         .release = ftrace_avail_release,
 };
 
+static struct file_operations ftrace_failures_fops = {
+        .open = ftrace_failures_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = ftrace_avail_release,
+};
+
 static struct file_operations ftrace_filter_fops = {
         .open = ftrace_filter_open,
         .read = ftrace_regex_read,
@@ -1386,6 +1419,11 @@ static __init int ftrace_init_debugfs(void)
                 pr_warning("Could not create debugfs "
                            "'available_filter_functions' entry\n");
 
+        entry = debugfs_create_file("failures", 0444,
+                                    d_tracer, NULL, &ftrace_failures_fops);
+        if (!entry)
+                pr_warning("Could not create debugfs 'failures' entry\n");
+
         entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer,
                                     NULL, &ftrace_filter_fops);
         if (!entry)