linux-kernel - Re: um: WARNING: vmlinux: 'memcpy' exported twice. Previous export was in vmlinux

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Message-ID: <20090310141352.GD3157@hack>
Date:	Tue, 10 Mar 2009 22:13:52 +0800
From:	Américo Wang <xiyou.wangcong@...il.com>
To:	Boaz Harrosh <bharrosh@...asas.com>
Cc:	Américo Wang <xiyou.wangcong@...il.com>,
	uml-devel <user-mode-linux-devel@...ts.sourceforge.net>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: um: WARNING: vmlinux: 'memcpy' exported twice. Previous export
	was in vmlinux

On Sun, Mar 08, 2009 at 12:49:16PM +0200, Boaz Harrosh wrote:
>Américo Wang wrote:
>> On Thu, Mar 05, 2009 at 07:27:31PM +0200, Boaz Harrosh wrote:
>>> Américo Wang wrote:
>>>> On Thu, Mar 05, 2009 at 03:45:36PM +0200, Boaz Harrosh wrote:
>>>>> Américo Wang wrote:
>>>>>> On Thu, Mar 05, 2009 at 02:13:58PM +0200, Boaz Harrosh wrote:
>>>>>>> On today's linus v2.6.29-rc7-3-g559595a
>>>>>>>
>>>>>>> Doing make ARCH=um defconfig & make ARCH=um
>>>>>>> give's me:
>>>>>>>
>>>>>>> LD vmlinux.o
>>>>>>> MODPOST vmlinux.o
>>>>>>> WARNING: vmlinux: 'memcpy' exported twice. Previous export was in vmlinux
>>>>>>>
>>>>>>>
>>>>>>> Sorry if this is a duplicate report
>>>>>>>
>>>>>> Weird...
>>>>>> I tried to compile like what you said, I can't reproduce it.
>>>>>>
>>>>>> Which gcc are you using?
>>>>>>
>>>>>> Thanks.
>>>>>>
>>>>> $ gcc --version
>>>>> gcc (GCC) 4.3.2 20081105 (Red Hat 4.3.2-7)
>>>>>
>>>>> I'm running on an x86_64 Fedora10 system (updated recently)
>>>>> $ uname -o -s -r -m -p -i
>>>>> Linux 2.6.27.15-170.2.24.fc10.x86_64 x86_64 x86_64 x86_64 GNU/Linux
>>>>>
>>>> I am using the same thing, but on i386. I still can't reproduce it. :(
>>>>
>>> What can I say I just did it again from scratch
>>>
>>> $ mkdir .build_um
>>> $ make ARCH=um KBUILD_OUTPUT=.build_um defconfig
>>> $ make ARCH=um KBUILD_OUTPUT=.build_um
>>>
>>> (I'm using KBUILD_OUTPUT= because O= does not work when also using M= with
>>> external modules, so it's a habit)
>>>
>>> Thanks for your help. I will try to bisect it on Sunday
>> 
>> Hi, Boaz.
>> 
>> I am sorry that I don't have an x86_64 machine to use, but I know
>> why this happens now. :)
>> 
>> Would you like to try the following patch? Thanks!
>> 
>> -------------->
>> 
>> Signed-off-by: WANG Cong <xiyou.wangcong@...il.com>
>> 
>
>Tested-by: Boaz Harrosh <bharrosh@...asas.com>
>

Thank you.

I will resend that patch with your Tested-by. :)

>> ---
>> diff --git a/arch/um/os-Linux/user_syms.c b/arch/um/os-Linux/user_syms.c
>> index 74f49bb..89b48a1 100644
>> --- a/arch/um/os-Linux/user_syms.c
>> +++ b/arch/um/os-Linux/user_syms.c
>> @@ -14,7 +14,6 @@
>>  #undef memset
>>  
>>  extern size_t strlen(const char *);
>> -extern void *memcpy(void *, const void *, size_t);
>>  extern void *memmove(void *, const void *, size_t);
>>  extern void *memset(void *, int, size_t);
>>  extern int printf(const char *, ...);
>> @@ -24,7 +23,11 @@ extern int printf(const char *, ...);
>>  EXPORT_SYMBOL(strstr);
>>  #endif
>>  
>> +#ifndef __x86_64__
>> +extern void *memcpy(void *, const void *, size_t);
>>  EXPORT_SYMBOL(memcpy);
>> +#endif
>> +
>>  EXPORT_SYMBOL(memmove);
>>  EXPORT_SYMBOL(memset);
>>  EXPORT_SYMBOL(printf);
>>  
>
>Yes this works. But it is weird, what is the difference between
>__x86_64__ and any other platform?

I just saw the comments in arch/um/sys-x86_64/ksyms.c.

-- 
Do what you love, f**k the rest! F**k the regulations!
 
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