Re: [PATCH] powerpc: Fix missing prototype problems for "arch/powerpc/kernel/setup_64.c"

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 15/03/2021 à 13:48, heying (H) a écrit :
> 
> 在 2021/3/15 20:17, Christophe Leroy 写道:
>> You subject doesn't match the content of the patch.
> OK. I'll adapt that.
>>
>> Le 15/03/2021 à 13:04, He Ying a écrit :
>>> The variables 'uaccess_fulsh' and 'entry_flush' are not referenced
>>> outside the file. So define them as static to avoid the warnings.
>>>
>>> And add a prototype for the function 'panic_smp_self_stop' for the
>>> same purpose.
>>>
>>> Sparse also warns that 'rfi_flush' should be static. However, it's
>>> referenced outside the file.
>>
>> To clear that warning, you have to include asm/security_features.h, rfi_flush is declared there.
> Do you mean that I should include this header in arch/powerpc/kernel/setup_64.c?

Yes

>>
>>>
>>> The warnings about the file reported by sparse are as follows:
>>> arch/powerpc/kernel/setup_64.c:422:6: warning: symbol 'panic_smp_self_stop' was not declared. 
>>> Should it be static?
>>> arch/powerpc/kernel/setup_64.c:951:6: warning: symbol 'rfi_flush' was not declared. Should it be 
>>> static?
>>> arch/powerpc/kernel/setup_64.c:952:6: warning: symbol 'entry_flush' was not declared. Should it 
>>> be static?
>>> arch/powerpc/kernel/setup_64.c:953:6: warning: symbol 'uaccess_flush' was not declared. Should it 
>>> be static?
>>>
>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>> Signed-off-by: He Ying <heying24@huawei.com>
>>> ---
>>>   arch/powerpc/kernel/setup_64.c | 6 ++++--
>>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
>>> index 560ed8b975e7..603aacd8527b 100644
>>> --- a/arch/powerpc/kernel/setup_64.c
>>> +++ b/arch/powerpc/kernel/setup_64.c
>>> @@ -71,6 +71,8 @@
>>>     #include "setup.h"
>>>   +extern void panic_smp_self_stop(void);
>>> +
>>
>> For function prototypes 'extern' is unneeded and deprecated.
>>
>> And function prototypes should go in an header file.
>>
>> panic_smp_self_stop() is called from kernel/panic.c , it should be declared in one of the generic 
>> linux header files I think.
> Yes, you're right. But I have no idea which header it should be declared in. May I have your 
> suggestions?

Maybe include/linux/smp.h ?

>>
>>>   int spinning_secondaries;
>>>   u64 ppc64_pft_size;
>>>   @@ -949,8 +951,8 @@ static bool no_rfi_flush;
>>>   static bool no_entry_flush;
>>>   static bool no_uaccess_flush;
>>>   bool rfi_flush;
>>> -bool entry_flush;
>>> -bool uaccess_flush;
>>> +static bool entry_flush;
>>> +static bool uaccess_flush;
>>>   DEFINE_STATIC_KEY_FALSE(uaccess_flush_key);
>>>   EXPORT_SYMBOL(uaccess_flush_key);
>>>
>> .