selftests/bpf: Fix file descriptor leak in load_kallsyms()

Currently, if sym_cnt > 0, it just returns and does not close file, fix it.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220405145711.49543-1-ytcoode@gmail.com

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 3d6217e..9c4be2c 100644 (file)
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -25,15 +25,12 @@ static int ksym_cmp(const void *p1, const void *p2)
 
 int load_kallsyms(void)
 {
-       FILE *f = fopen("/proc/kallsyms", "r");
+       FILE *f;
        char func[256], buf[256];
        char symbol;
        void *addr;
        int i = 0;
 
-       if (!f)
-               return -ENOENT;
-
        /*
         * This is called/used from multiplace places,
         * load symbols just once.
@@ -41,6 +38,10 @@ int load_kallsyms(void)
        if (sym_cnt)
                return 0;
 
+       f = fopen("/proc/kallsyms", "r");
+       if (!f)
+               return -ENOENT;
+
        while (fgets(buf, sizeof(buf), f)) {
                if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
                        break;