Re: linux-next: Tree for Jan 12 (build failures: m68k, ppc)

[Guenter Roeck <linux@roeck-us.net>]

On 01/15/2015 02:12 AM, Geert Uytterhoeven wrote:
> On Mon, Jan 12, 2015 at 6:59 PM, Guenter Roeck <linux@roeck-us.net> wrote:
>>>> Build failures, seen since next-20150109:
>>>>          m68k:allmodconfig
>>>>          powerpc:ppc6xx_defconfig
>
> It looks like parisc is also suffering:
> http://kisskb.ellerman.id.au/kisskb/buildresult/12343847/
>
>>>> Due to:
>>>>          ERROR: "__get_user_bad" [drivers/gpu/drm/drm.ko] undefined!
>>>>          make[1]: *** [__modpost] Error 1
>>>>
>>>> Caused by commit d34f20d6e2f (drm: Atomic modeset ioctl).
>>>
>>> Yeah, it needs a get_user() that supports 64-bit data.
>>>
>> Hi Geert,
>>
>> I assume you mean m68k, where 64 bit support for get_user has been disabled.
>>
>> The problem on powerpc is different though: __get_user_nocheck()
>> and __get_user_check() use
>>          unsigned long __gu_val;
>> followed by
>>          __get_user_size(__gu_val, __gu_addr, (size), __gu_err);
>>
>> __get_user_size() fails in
>>          if (size > sizeof(x))
>>                   (x) = __get_user_bad();
>>
>> Presumably "unsigned long" is 32 bit on 32 bit powerpc, not 64 bit.
>>
>> Overall, the explicit 64-bit use of get_user() seems to be quite unusual.
>
> I noticed you've sent a fix for DRM.
>
> Doh, and I was just fixing m68k...
>

Sorry, should have Cc:'d you.

Guenter