[PATCH v2] smbios: Fix table when no string is present

[Simon Glass]

Hi Matthias,

On Tue, 6 Apr 2021 at 21:04, <matthias.bgg at kernel.org> wrote:
>
> From: Matthias Brugger <mbrugger at suse.com>
>
> When no string is present in a table, next_ptr points to the same
> location as eos. When calculating the string table length, we would only
> reserve one \0. By spec a SMBIOS table has to end with two \0\0 when no
> strings a present.
>
> Signed-off-by: Matthias Brugger <mbrugger at suse.com>
>
> ---
>
> Changes in v2:
> - check in smbios_string_table_len if no string present and return value
>   accordingly

This looks like a better idea to me. But where are the \0 bytes
actually written? Perhaps that should be in smbios_set_eos()?

>
>  lib/smbios.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/lib/smbios.c b/lib/smbios.c
> index 9eb226ec9f..fd57d8694f 100644
> --- a/lib/smbios.c
> +++ b/lib/smbios.c
> @@ -191,6 +191,10 @@ int smbios_update_version(const char *version)
>   */
>  static int smbios_string_table_len(const struct smbios_ctx *ctx)
>  {
> +       /* In case no string is defined we have to return two \0 */
> +       if (ctx->next_ptr == ctx->eos)
> +               return 2;
> +
>         /* Allow for the final \0 after all strings */
>         return (ctx->next_ptr + 1) - ctx->eos;
>  }
> --
> 2.30.2
>

Regards,
Simon