From: "Steven Rostedt (VMware)" 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) --- 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