libbpf: Use IS_ERR_OR_NULL() in hashmap__free()

hashmap__new() uses ERR_PTR() to return an error so it's better to
use IS_ERR_OR_NULL() in order to check the pointer before calling
free(). This will prevent freeing an invalid pointer if somebody calls
hashmap__free() with the result of a failed hashmap__new() call.

Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220107152620.192327-1-mauricio@kinvolk.io

diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
index 3c20b12..aeb09c2 100644 (file)
--- a/tools/lib/bpf/hashmap.c
+++ b/tools/lib/bpf/hashmap.c
@@ -75,7 +75,7 @@ void hashmap__clear(struct hashmap *map)
 
 void hashmap__free(struct hashmap *map)
 {
-       if (!map)
+       if (IS_ERR_OR_NULL(map))
                return;
 
        hashmap__clear(map);
@@ -238,4 +238,3 @@ bool hashmap__delete(struct hashmap *map, const void *key,
 
        return true;
 }
-