From: Quentin Monnet <quentin.monnet@netronome.com>
Date: Tue, 28 Nov 2017 17:44:29 -0800
Subject: tools: bpftool: clean up the JSON writer before exiting in usage()
Patch-mainline: v4.15-rc3
Git-commit: 7868620a3c15dbc661fb5d849de403ac04624c50
References: bsc#1109837

The writer is cleaned at the end of the main function, but not if the
program exits sooner in usage(). Let's keep it clean and destroy the
writer before exiting.

Destruction and actual call to exit() are moved to another function so
that clean exit can also be performed without printing usage() hints.

Fixes: d35efba99d92 ("tools: bpftool: introduce --json and --pretty options")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 tools/bpf/bpftool/main.c |   10 +++++++++-
 tools/bpf/bpftool/main.h |    3 ++-
 2 files changed, 11 insertions(+), 2 deletions(-)

--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -58,11 +58,19 @@ bool show_pinned;
 struct pinned_obj_table prog_table;
 struct pinned_obj_table map_table;
 
+static void __noreturn clean_and_exit(int i)
+{
+	if (json_output)
+		jsonw_destroy(&json_wtr);
+
+	exit(i);
+}
+
 void usage(void)
 {
 	last_do_help(last_argc - 1, last_argv + 1);
 
-	exit(-1);
+	clean_and_exit(-1);
 }
 
 static int do_help(int argc, char **argv)
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -41,6 +41,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <linux/bpf.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/hashtable.h>
 
@@ -80,7 +81,7 @@ void p_info(const char *fmt, ...);
 
 bool is_prefix(const char *pfx, const char *str);
 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep);
-void usage(void) __attribute__((noreturn));
+void usage(void) __noreturn;
 
 struct pinned_obj_table {
 	DECLARE_HASHTABLE(table, 16);