Re: [PATCH v2 1/2] libbpf: add support for printing BTF character arrays as strings

On Tue, Jun 3, 2025 at 6:18 AM Jiri Olsa olsajiri@gmail.com wrote:

...

+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 ?

Good question. That E2BIG error would happen, for example, if we tried to print the array "{ 'a', 'b', 'c' }" when the type was "char[4]". I'd say your proposed behavior would be consistent with the semantic of ".emit_strings should display strings in an intuitively useful way", and I'd be in favor of doing that (replacing "return -E2BIG" with "break"). If others agree (specifically Andrii, who had comments about the semantics yesterday), I'll make that change.

Blake