Re: [PATCH] powerpc: arch/powerpc/kernel/setup_64.c - cleanup warnings

From: Daniel Axtens <dja@axtens.net>
To: "heying \(H\)" <heying24@huawei.com>,
	mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org,
	npiggin@gmail.com, akpm@linux-foundation.org,
	aneesh.kumar@linux.ibm.com, rppt@kernel.org, ardb@kernel.org,
	clg@kaod.org, christophe.leroy@csgroup.eu
Cc: johnny.chenyi@huawei.com, linuxppc-dev@lists.ozlabs.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc: arch/powerpc/kernel/setup_64.c - cleanup warnings
Date: Wed, 17 Mar 2021 18:58:14 +1100	[thread overview]
Message-ID: <87tupab4a1.fsf@dja-thinkpad.axtens.net> (raw)
In-Reply-To: <f0130916-a8f3-75ba-b5da-7d37d9139ff3@huawei.com>

"heying (H)" <heying24@huawei.com> writes:

> Thank you for your reply.
>
>
> 在 2021/3/17 11:04, Daniel Axtens 写道:
>> Hi He Ying,
>>
>> Thank you for this patch.
>>
>> I'm not sure what the precise rules for Fixes are, but I wonder if this
>> should have:
>>
>> Fixes: 9a32a7e78bd0 ("powerpc/64s: flush L1D after user accesses")
>> Fixes: f79643787e0a ("powerpc/64s: flush L1D on kernel entry")
>
> Is that necessary for warning cleanups? I thought 'Fixes' tags are 
> needed only for
>
> bugfix patches. Can someone tell me whether I am right?

Yeah, I'm not sure either. Hopefully mpe will let us know.

Kind regards,
Daniel

>
>>
>> Those are the commits that added the entry_flush and uaccess_flush
>> symbols. Perhaps one for rfi_flush too but I'm not sure what commit
>> introduced that.
>>
>> Kind regards,
>> Daniel
>>
>>> warning: symbol 'rfi_flush' was not declared.
>>> warning: symbol 'entry_flush' was not declared.
>>> warning: symbol 'uaccess_flush' was not declared.
>>> We found warnings above in arch/powerpc/kernel/setup_64.c by using
>>> sparse tool.
>>>
>>> Define 'entry_flush' and 'uaccess_flush' as static because they are not
>>> referenced outside the file. Include asm/security_features.h in which
>>> 'rfi_flush' is declared.
>>>
>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>> Signed-off-by: He Ying <heying24@huawei.com>
>>> ---
>>>   arch/powerpc/kernel/setup_64.c | 5 +++--
>>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
>>> index 560ed8b975e7..f92d72a7e7ce 100644
>>> --- a/arch/powerpc/kernel/setup_64.c
>>> +++ b/arch/powerpc/kernel/setup_64.c
>>> @@ -68,6 +68,7 @@
>>>   #include <asm/early_ioremap.h>
>>>   #include <asm/pgalloc.h>
>>>   #include <asm/asm-prototypes.h>
>>> +#include <asm/security_features.h>
>>>   
>>>   #include "setup.h"
>>>   
>>> @@ -949,8 +950,8 @@ 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);
>>>   
>>> -- 
>>> 2.17.1
>> .