[PATCH v12 06/25] readelf: dump Object Attributes v2

[Jan Beulich]

On 20.01.2026 17:25, Matthieu Longo wrote:
> +static const unsigned char *
> +display_attr_v2 (const unsigned char *cursor,
> +		 const unsigned char *const end,
> +		 const oav2_known_subsection_t *subsec_info,
> +		 obj_attr_encoding_v2_t value_encoding,
> +		 display_arch_attr_t display_arch_attr)
> +{
> +  obj_attr_tag_t tag;
> +  READ_ULEB (tag, cursor, end);
> +
> +  const oav2_known_tag_t *tag_info = NULL;
> +  if (subsec_info != NULL)
> +    tag_info = oav2_identify_tag (subsec_info, tag);
> +
> +  if (tag_info != NULL)
> +    return display_arch_attr (cursor, end, tag_info, value_encoding);
> +
> +  printf ("    Tag_unknown_%lu:	", tag);

Why %lu? Prior to this series obj_attr_tag_t is a typedef of uint32_t, and
I don't expect you alter it to unsigned long (if anything I guess you
might be widening it to uint64_t)?

> +static BufferReadOp_t
> +elf_parse_attrs_subsection_v2 (const unsigned char *cursor,
> +			       const uint64_t max_read,
> +			       const char *public_name,
> +			       display_arch_attr_t display_arch_attr)
> +{
> +  BufferReadOp_t op = { .err = false, .read = 0 };
> +
> +  const uint32_t F_SUBSECTION_LEN = sizeof (uint32_t);
> +  const uint32_t F_SUBSECTION_COMPREHENSION = sizeof(uint8_t);
> +  const uint32_t F_SUBSECTION_ENCODING = sizeof(uint8_t);
> +  /* The minimum subsection length is 7: 4 bytes for the length itself, and 1
> +     byte for an empty NUL-terminated string, 1 byte for the comprehension,
> +     1 byte for the encoding, and no vendor-data.  */
> +  const uint32_t F_MIN_SUBSECTION_DATA_LEN
> +    = F_SUBSECTION_LEN + 1 /* for '\0' */
> +      + F_SUBSECTION_COMPREHENSION + F_SUBSECTION_ENCODING;
> +
> +  /* Handle cases where the attributes data is not strictly valid (e.g. due to
> +     fuzzing).  */
> +  if (max_read < F_MIN_SUBSECTION_DATA_LEN)
> +    {
> +      error (_("Object attributes section ends prematurely\n"));
> +      return op;
> +    }
> +
> +  unsigned int subsection_len = byte_get (cursor, F_SUBSECTION_LEN);
> +  cursor += F_SUBSECTION_LEN;
> +  op.read += F_SUBSECTION_LEN;
> +  if (subsection_len > max_read)
> +    {
> +      error (_("Bad subsection length: too big (%u > max=%lu)\n"),

Why (still) %lu when max_read is uint64_t?

> +	     subsection_len, max_read);
> +      /* Error, but still try to display the content until meeting a more
> +	 serious error.  */
> +      subsection_len = max_read;
> +      op.err = true;
> +    }
> +  else if (subsection_len < F_MIN_SUBSECTION_DATA_LEN)
> +    {
> +      error (_("Bad subsection length: too small (%u < min=%u)\n"),
> +	     subsection_len, F_MIN_SUBSECTION_DATA_LEN);

This again is %u vs the variable's (really: constant's) type being uint32_t
(for not really an apparent reason, like the other F_* as well).

Okay with at least all the format character issues addressed.

Jan