Re: [PATCH] DMI: Always call dmi_present with DMI structure

From: H.J. Lu
Date: Thu Feb 21 2013 - 14:06:26 EST


On Wed, Feb 20, 2013 at 6:58 PM, Zhenzhong Duan
<zhenzhong.duan@xxxxxxxxxx> wrote:
> Hi
> Ben had sent a patch fixing this issue. Would you like to test his patch?
> https://lkml.org/lkml/2013/2/16/102
> zduan

The patch has a typo:

- offset = 16;
+ return memcmp(q + 16, "_DMI_", 5) || dmi_present(p + 16);
}

'q' isn't defined here. Change it to `p" also fixes the problem for me.


H.J.
---
> On 2013-02-21 02:12, H.J. Lu wrote:
>>
>> Hi,
>>
>> This patch:
>>
>> commit 9f9c9cbb60576a1518d0bf93fb8e499cffccf377
>> Author: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
>> Date: Thu Dec 20 15:05:14 2012 -0800
>>
>> drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it
>> exists
>>
>> The right dmi version is in SMBIOS if it's zero in DMI region
>>
>> This issue was originally found from an oracle bug.
>> One customer noticed system UUID doesn't match between dmidecode &
>> uek2.
>>
>> - HP ProLiant BL460c G6 :
>> # cat /sys/devices/virtual/dmi/id/product_uuid
>> 00000000-0000-4C48-3031-4D5030333531
>> # dmidecode | grep -i uuid drivers/firmware/dmi_scan.c:
>> fetch dmi version from SMBIOS if it exists
>>
>> The right dmi version is in SMBIOS if it's zero in DMI region
>>
>> This issue was originally found from an oracle bug.
>> One customer noticed system UUID doesn't match between dmidecode &
>> uek2.
>>
>> - HP ProLiant BL460c G6 :
>> # cat /sys/devices/virtual/dmi/id/product_uuid
>> 00000000-0000-4C48-3031-4D5030333531
>> # dmidecode | grep -i uuid
>> UUID: 00000000-0000-484C-3031-4D5030333531
>>
>> From SMBIOS 2.6 on, spec use little-endian encoding for UUID other
>> than
>> network byte order.
>>
>> So we need to get dmi version to distinguish. If version is 0.0, the
>> real version is taken from the SMBIOS version. This is part of
>> original
>> kernel comment in code.
>>
>> UUID: 00000000-0000-484C-3031-4D5030333531
>>
>> From SMBIOS 2.6 on, spec use little-endian encoding for UUID other
>> than
>> network byte order.
>>
>> So we need to get dmi version to distinguish. If version is 0.0, the
>> real version is taken from the SMBIOS version. This is part of
>> original
>> kernel comment in code.
>>
>> causes a regression in 3.7, 3.8 and 3.9 kernels. Before the change,
>> we only scan DMI structure. Now smbios_present scans SMBIOS
>> entry point. I have a machine which has invalid checksum in
>> SMBIOS entry point. We wind up calling dmi_present with SMBIOS
>> entry point instead of DMI structure. This patch changes smbios_present
>> to always call dmi_present with DMI structure.
>>
>>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/