bpf: Factor out verbose_invalid_scalar()

Factor out the function verbose_invalid_scalar() to verbose
print if a scalar is not in a tnum range. There is no
functionality change and the function will be used by
later patch which introduced bpf_for_each_map_elem().

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204922.3884375-1-yhs@fb.com

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b14fab7a7a164b62a352b545b471f1edc64ee7da..7194980c3ca41c08a9805e0569f6eab7e1d75456 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -390,6 +390,24 @@ __printf(3, 4) static void verbose_linfo(struct bpf_verifier_env *env,
        env->prev_linfo = linfo;
 }
 
+static void verbose_invalid_scalar(struct bpf_verifier_env *env,
+                                  struct bpf_reg_state *reg,
+                                  struct tnum *range, const char *ctx,
+                                  const char *reg_name)
+{
+       char tn_buf[48];
+
+       verbose(env, "At %s the register %s ", ctx, reg_name);
+       if (!tnum_is_unknown(reg->var_off)) {
+               tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+               verbose(env, "has value %s", tn_buf);
+       } else {
+               verbose(env, "has unknown scalar value");
+       }
+       tnum_strn(tn_buf, sizeof(tn_buf), *range);
+       verbose(env, " should have been in %s\n", tn_buf);
+}
+
 static bool type_is_pkt_pointer(enum bpf_reg_type type)
 {
        return type == PTR_TO_PACKET ||
@@ -8455,17 +8473,7 @@ static int check_return_code(struct bpf_verifier_env *env)
        }
 
        if (!tnum_in(range, reg->var_off)) {
-               char tn_buf[48];
-
-               verbose(env, "At program exit the register R0 ");
-               if (!tnum_is_unknown(reg->var_off)) {
-                       tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-                       verbose(env, "has value %s", tn_buf);
-               } else {
-                       verbose(env, "has unknown scalar value");
-               }
-               tnum_strn(tn_buf, sizeof(tn_buf), range);
-               verbose(env, " should have been in %s\n", tn_buf);
+               verbose_invalid_scalar(env, reg, &range, "program exit", "R0");
                return -EINVAL;
        }