[for-next][PATCH 3/8] ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY

From: Steven Rostedt
Date: Fri Feb 03 2017 - 08:42:19 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

When the set_graph_function or set_graph_notrace contains no records, a
banner is displayed of either "#### all functions enabled ####" or
"#### all functions disabled ####" respectively. To tell the seq operations
to do this, (void *)1 is passed as a return value. Instead of using a
hardcoded meaningless variable, define it as a macro.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1595df0d7d79..a9cfc8713198 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4561,6 +4561,8 @@ enum graph_filter_type {
GRAPH_FILTER_FUNCTION,
};

+#define FTRACE_GRAPH_EMPTY ((void *)1)
+
struct ftrace_graph_data {
struct ftrace_hash *hash;
struct ftrace_func_entry *entry;
@@ -4616,7 +4618,7 @@ static void *g_start(struct seq_file *m, loff_t *pos)

/* Nothing, tell g_show to print all functions are enabled */
if (ftrace_hash_empty(fgd->hash) && !*pos)
- return (void *)1;
+ return FTRACE_GRAPH_EMPTY;

fgd->idx = 0;
fgd->entry = NULL;
@@ -4635,7 +4637,7 @@ static int g_show(struct seq_file *m, void *v)
if (!entry)
return 0;

- if (entry == (void *)1) {
+ if (entry == FTRACE_GRAPH_EMPTY) {
struct ftrace_graph_data *fgd = m->private;

if (fgd->type == GRAPH_FILTER_FUNCTION)
--
2.10.2