On Thu, Feb 25, 2021 at 1:35 AM Yonghong Song <yhs@xxxxxx> wrote:
>
> 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@xxxxxx>
> ---
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> kernel/bpf/verifier.c | 31 ++++++++++++++++++++-----------
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 9cb182e91162..a657860ecba5 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -390,6 +390,25 @@ __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);
> +}
> +
> +
nit: double empty line
> static bool type_is_pkt_pointer(enum bpf_reg_type type)
> {
> return type == PTR_TO_PACKET ||
> @@ -8455,17 +8474,7 @@ 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;
> }
>
> --
> 2.24.1
>
