Re: [PATCH v4 0/5] x86: Cleanup and simplify cpu-specific data

["H. Peter Anvin" <hpa@zytor.com>]

On 02/27/2012 04:52 PM, Kevin Winchester wrote:
> On 27 February 2012 07:59, Ingo Molnar<mingo@elte.hu>  wrote:
>>
>> * Kevin Winchester<kjwinchester@gmail.com>  wrote:
>>
>>> Various per-cpu fields are define in arch/x86/kernel/smpboot.c
>>> that are basically equivalent to the cpu-specific data in
>>> struct cpuinfo_x86. By moving these fields into the structure,
>>> a number of codepaths can be simplified since they no longer
>>> need to care about those fields not existing on !SMP builds.
>>
>> Works mostly fine, except with the attached 32-bit UP !APIC
>> config I get various build failures (resolved via the patch
>> below) and a link failure (not resolved):
>>
>
> I get the following failure before I get to link time:
>
> In file included from
> /home/kevin/linux/linux-2.6/arch/x86/include/asm/uaccess.h:573:0,
>                   from
> /home/kevin/linux/linux-2.6/arch/x86/include/asm/sections.h:5,
>                   from
> /home/kevin/linux/linux-2.6/arch/x86/include/asm/hw_irq.h:26,
>                   from include/linux/irq.h:357,
>                   from
> /home/kevin/linux/linux-2.6/arch/x86/include/asm/hardirq.h:5,
>                   from include/linux/hardirq.h:7,
>                   from include/linux/interrupt.h:12,
>                   from net/core/pktgen.c:135:
> In function ‘copy_from_user’,
>      inlined from ‘pktgen_if_write’ at net/core/pktgen.c:877:20:
> /home/kevin/linux/linux-2.6/arch/x86/include/asm/uaccess_32.h:211:26:
> error: call to ‘copy_from_user_overflow’ declared with attribute
> error: copy_from_user() buffer size is not provably correct
> make[2]: *** [net/core/pktgen.o] Error 1
>
> On:
>
> gcc (GCC) 4.6.2 20120120 (prerelease)
>
> Is that my fault, or something else?
>
> Kevin
>

That comes from compiling with warnings as errors.  Not that someone 
shouldn't look at that kind of problem.

	-hpa