On Mon, Jun 02, 2025 at 09:48:12PM -0700, Blake Jones wrote:
SNIP
> diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
> index 460c3e57fadb..336a6646e0fa 100644
> --- a/tools/lib/bpf/btf_dump.c
> +++ b/tools/lib/bpf/btf_dump.c
> @@ -68,6 +68,7 @@ struct btf_dump_data {
> bool compact;
> bool skip_names;
> bool emit_zeroes;
> + bool emit_strings;
> __u8 indent_lvl; /* base indent level */
> char indent_str[BTF_DATA_INDENT_STR_LEN];
> /* below are used during iteration */
> @@ -2028,6 +2029,43 @@ static int btf_dump_var_data(struct btf_dump *d,
> return btf_dump_dump_type_data(d, NULL, t, type_id, data, 0, 0);
> }
>
> +static int btf_dump_string_data(struct btf_dump *d,
> + const struct btf_type *t,
> + __u32 id,
> + const void *data)
> +{
> + const struct btf_array *array = btf_array(t);
> + __u32 i;
> +
> + btf_dump_data_pfx(d);
> + btf_dump_printf(d, "\"");
> +
> + for (i = 0; i < array->nelems; i++, data++) {
> + char c;
> +
> + if (data >= d->typed_dump->data_end)
> + return -E2BIG;
curious, is this just string array without null terminating byte?
should we just print " and return 0 instead of E2BIG error ?
thanks,
jirka
> +
> + c = *(char *)data;
> + if (c == '\0') {
> + /*
> + * When printing character arrays as strings, NUL bytes
> + * are always treated as string terminators; they are
> + * never printed.
> + */
> + break;
> + }
> + if (isprint(c))
> + btf_dump_printf(d, "%c", c);
> + else
> + btf_dump_printf(d, "\\x%02x", *(__u8 *)data);
> + }
> +
> + btf_dump_printf(d, "\"");
> +
> + return 0;
> +}
> +
> static int btf_dump_array_data(struct btf_dump *d,
> const struct btf_type *t,
> __u32 id,
> @@ -2055,8 +2093,11 @@ static int btf_dump_array_data(struct btf_dump *d,
> * char arrays, so if size is 1 and element is
> * printable as a char, we'll do that.
> */
> - if (elem_size == 1)
> + if (elem_size == 1) {
> + if (d->typed_dump->emit_strings)
> + return btf_dump_string_data(d, t, id, data);
> d->typed_dump->is_array_char = true;
> + }
> }
>
> /* note that we increment depth before calling btf_dump_print() below;
> @@ -2544,6 +2585,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32
> id,
> d->typed_dump->compact = OPTS_GET(opts, compact, false);
> d->typed_dump->skip_names = OPTS_GET(opts, skip_names, false);
> d->typed_dump->emit_zeroes = OPTS_GET(opts, emit_zeroes, false);
> + d->typed_dump->emit_strings = OPTS_GET(opts, emit_strings, false);
>
> ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);
>
> --
> 2.49.0.1204.g71687c7c1d-goog
>
