Re: [dmidecode] [PATCH] dmidecode: Set vendor early

[Jerry Hoemann]

On Wed, Jan 13, 2021 at 09:52:59AM +0100, Jean Delvare wrote:
> If OEM type entries come before the type 1 entry (System
> Information), we aren't able to decode them because we don't know
> the vendor yet. To fix this, figure out the vendor during a first
> pass, and walk the table again once we have the information.
> 
> Signed-off-by: Jean Delvare <jdelvare@suse.de>
> Reported-by: Erwan Velu <e.velu@criteo.com>

Tested.  Addresses the issue I see with the HPE OEM 236 record.

Thanks

> ---
>  dmidecode.c |   50 +++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 45 insertions(+), 5 deletions(-)
> 
> --- dmidecode.orig/dmidecode.c        2021-01-05 12:45:19.744939071 +0100
> +++ dmidecode/dmidecode.c     2021-01-05 12:50:22.518420537 +0100
> @@ -5182,6 +5182,51 @@ static void dmi_table_decode(u8 *buf, u3
>       u8 *data;
>       int i = 0;
>  
> +     /* First pass: Save the vendor so that so that we can decode OEM types 
> */
> +     data = buf;
> +     while ((i < num || !num)
> +         && data + 4 <= buf + len) /* 4 is the length of an SMBIOS structure 
> header */
> +     {
> +             u8 *next;
> +             struct dmi_header h;
> +
> +             to_dmi_header(&h, data);
> +
> +             /*
> +              * If a short entry is found (less than 4 bytes), not only it
> +              * is invalid, but we cannot reliably locate the next entry.
> +              * Also stop at end-of-table marker if so instructed.
> +              */
> +             if (h.length < 4 ||
> +                 (h.type == 127 &&
> +                  (opt.flags & (FLAG_QUIET | FLAG_STOP_AT_EOT))))
> +                     break;
> +             i++;
> +
> +             /* Look for the next handle */
> +             next = data + h.length;
> +             while ((unsigned long)(next - buf + 1) < len
> +                 && (next[0] != 0 || next[1] != 0))
> +                     next++;
> +             next += 2;
> +
> +             /* Make sure the whole structure fits in the table */
> +             if ((unsigned long)(next - buf) > len)
> +                     break;
> +
> +             /* Assign vendor for vendor-specific decodes later */
> +             if (h.type == 1 && h.length >= 6)
> +             {
> +                     dmi_set_vendor(_dmi_string(&h, data[0x04], 0),
> +                                    _dmi_string(&h, data[0x05], 0));
> +                     break;
> +             }
> +
> +             data = next;
> +     }
> +
> +     /* Second pass: Actually decode the data */
> +     i = 0;
>       data = buf;
>       while ((i < num || !num)
>           && data + 4 <= buf + len) /* 4 is the length of an SMBIOS structure 
> header */
> @@ -5241,11 +5286,6 @@ static void dmi_table_decode(u8 *buf, u3
>                       break;
>               }
>  
> -             /* assign vendor for vendor-specific decodes later */
> -             if (h.type == 1 && h.length >= 6)
> -                     dmi_set_vendor(_dmi_string(&h, data[0x04], 0),
> -                                    _dmi_string(&h, data[0x05], 0));
> -
>               /* Fixup a common mistake */
>               if (h.type == 34)
>                       dmi_fixup_type_34(&h, display);
> 
> 
> -- 
> Jean Delvare
> SUSE L3 Support

-- 

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Jerry Hoemann                  Software Engineer   Hewlett Packard Enterprise
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