From:   Miaoqian Lin <linmq006@gmail.com>
Cc:     linmq006@gmail.com, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Quentin Monnet <quentin@isovalent.com>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] bpftool: Fix NULL vs IS_ERR() checking for return value of hashmap__new
Date:   Sun, 12 Dec 2021 05:18:09 +0000
Message-Id: <20211212051816.20478-1-linmq006@gmail.com>
To:     unlisted-recipients:; (no To-header on input)
Precedence: bulk

The hashmap__new() function does not return NULL on errors. It returns
ERR_PTR(-ENOMEM). Using IS_ERR() to check the return value to fix this.

Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 tools/bpf/bpftool/link.c | 2 +-
 tools/bpf/bpftool/map.c  | 2 +-
 tools/bpf/bpftool/pids.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index 2c258db0d352..0dc402a89cd8 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -306,7 +306,7 @@ static int do_show(int argc, char **argv)
 	if (show_pinned) {
 		link_table = hashmap__new(hash_fn_for_key_as_id,
 					  equal_fn_for_key_as_id, NULL);
-		if (!link_table) {
+		if (IS_ERR(link_table)) {
 			p_err("failed to create hashmap for pinned paths");
 			return -1;
 		}
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index cae1f1119296..af83ae37d247 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -698,7 +698,7 @@ static int do_show(int argc, char **argv)
 	if (show_pinned) {
 		map_table = hashmap__new(hash_fn_for_key_as_id,
 					 equal_fn_for_key_as_id, NULL);
-		if (!map_table) {
+		if (IS_ERR(map_table)) {
 			p_err("failed to create hashmap for pinned paths");
 			return -1;
 		}
diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c
index 56b598eee043..6c4767e97061 100644
--- a/tools/bpf/bpftool/pids.c
+++ b/tools/bpf/bpftool/pids.c
@@ -101,7 +101,7 @@ int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
 	libbpf_print_fn_t default_print;
 
 	*map = hashmap__new(hash_fn_for_key_as_id, equal_fn_for_key_as_id, NULL);
-	if (!*map) {
+	if (IS_ERR(*map)) {
 		p_err("failed to create hashmap for PID references");
 		return -1;
 	}
-- 
2.17.1