Re: [PATCH 10/16] compile error: MIPS: add definitions for extended context

[Hauke Mehrtens <hauke@hauke-m.de>]

On 10/25/2015 10:47 PM, Florian Fainelli wrote:
> Le 25/10/2015 14:10, Hauke Mehrtens a écrit :
>> This patch is causing a build error for me on 4.3-rc7.
>>
>>   CC      arch/mips/kernel/signal.o
>> arch/mips/kernel/signal.c: In function 'sc_to_extcontext':
>> arch/mips/kernel/signal.c:143:12: error: 'struct ucontext' has no member
>> named 'uc_extcontext'
>>   return &uc->uc_extcontext;
>>             ^
>> In file included from include/linux/poll.h:11:0,
>>                  from include/linux/ring_buffer.h:7,
>>                  from include/linux/trace_events.h:5,
>>                  from include/trace/syscall.h:6,
>>                  from include/linux/syscalls.h:81,
>>                  from arch/mips/kernel/signal.c:26:
>> arch/mips/kernel/signal.c: In function 'save_msa_extcontext':
>> arch/mips/kernel/signal.c:171:40: error: dereferencing pointer to
>> incomplete type 'struct msa_extcontext'
>>    err = __put_user(read_msa_csr(), &msa->csr);
>>                                         ^
>> ./arch/mips/include/asm/uaccess.h:441:15: note: in definition of macro
>> '__put_user_nocheck'
>>   __typeof__(*(ptr)) __pu_val;     \
>>                ^
>> arch/mips/kernel/signal.c:171:9: note: in expansion of macro '__put_user'
>>    err = __put_user(read_msa_csr(), &msa->csr);
>>          ^
>> arch/mips/kernel/signal.c:186:20: error: 'MSA_EXTCONTEXT_MAGIC'
>> undeclared (first use in this function)
>>   err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
>>                     ^
>> ./arch/mips/include/asm/uaccess.h:444:14: note: in definition of macro
>> '__put_user_nocheck'
>>   __pu_val = (x);       \
>>               ^
>> arch/mips/kernel/signal.c:186:9: note: in expansion of macro '__put_user'
>>   err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
>>          ^
>> arch/mips/kernel/signal.c:186:20: note: each undeclared identifier is
>> reported only once for each function it appears in
>>   err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
>>                     ^
>> ./arch/mips/include/asm/uaccess.h:444:14: note: in definition of macro
>> '__put_user_nocheck'
>>   __pu_val = (x);       \
>>               ^
>> arch/mips/kernel/signal.c:186:9: note: in expansion of macro '__put_user'
>>   err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
>>          ^
>> .......
>>
>>
>> When I include uapi/asm/ucontext.h instead of asm/ucontext.h in signal.c
>> it compiles again.
> 
> The problem appears if you had previously auto-generated files in
> arch/mips/include/generated that do not get automatically cleaned up
> when you switch to a new kernel version, and with an incompatible
> ucontext layout between the two.
> 
> Jacek tripped over that here:
> 
> https://www.linux-mips.org/archives/linux-mips/2015-09/msg00150.html
> 
> and I asked whether we could follow-up with a proper Kbuild patch to
> address that build dependency here:
> 
> https://www.linux-mips.org/archives/linux-mips/2015-09/msg00165.html
> 
> but this does not appear to have been proposed or addressed yet.
> 
> Paul, could you look into this and see how we could teach Kbuild about
> this build dependency?
> 

Yes that was the problem, after doing this I worked again:
rm arch/mips/include/generated/ -rf

Hauke