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Subject: Re: [PATCH] hw_breakpoint: Fix build warnings with clang
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        christophe.leroy@c-s.fr, mikey@neuling.org, apopple@linux.ibm.com,
        linux-kernel@vger.kernel.org, npiggin@gmail.com, paulus@samba.org,
        naveen.n.rao@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
        Ravi Bangoria <ravi.bangoria@linux.ibm.com>
References: <20200602041208.128913-1-ravi.bangoria@linux.ibm.com>
 <0217bbaf-a831-8aea-3ecd-fa217fca1669@csgroup.eu>
 <87d06hivfs.fsf@mpe.ellerman.id.au>
From:   Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Message-ID: <99295a0b-cda7-4570-e68c-b78510b2771d@linux.ibm.com>
Date:   Tue, 2 Jun 2020 16:49:53 +0530
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On 6/2/20 4:30 PM, Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>> Le 02/06/2020 à 06:12, Ravi Bangoria a écrit :
>>> kbuild test robot reported few build warnings with hw_breakpoint code
>>> when compiled with clang[1]. Fix those.
>>>
>>> [1]: https://lore.kernel.org/linuxppc-dev/202005192233.oi9CjRtA%25lkp@intel.com/
>>>
> 
> This should have mentioned that some of the errors were recently
> introduced by your commit.

Sure, will take care next time.

> 
>>> Reported-by: kbuild test robot <lkp@intel.com>
>>> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
>>> ---
>>> Note: Prepared on top of powerpc/next.
>>>
>>>    arch/powerpc/include/asm/hw_breakpoint.h | 3 ---
>>>    include/linux/hw_breakpoint.h            | 4 ++++
>>>    2 files changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
>>> index f42a55eb77d2..cb424799da0d 100644
>>> --- a/arch/powerpc/include/asm/hw_breakpoint.h
>>> +++ b/arch/powerpc/include/asm/hw_breakpoint.h
>>> @@ -70,9 +70,6 @@ extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
>>>    						unsigned long val, void *data);
>>>    int arch_install_hw_breakpoint(struct perf_event *bp);
>>>    void arch_uninstall_hw_breakpoint(struct perf_event *bp);
>>> -int arch_reserve_bp_slot(struct perf_event *bp);
>>> -void arch_release_bp_slot(struct perf_event *bp);
>>> -void arch_unregister_hw_breakpoint(struct perf_event *bp);
>>>    void hw_breakpoint_pmu_read(struct perf_event *bp);
>>>    extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
>>>    
>>> diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
>>> index 6058c3844a76..521481f0d320 100644
>>> --- a/include/linux/hw_breakpoint.h
>>> +++ b/include/linux/hw_breakpoint.h
>>> @@ -80,6 +80,10 @@ extern int dbg_reserve_bp_slot(struct perf_event *bp);
>>>    extern int dbg_release_bp_slot(struct perf_event *bp);
>>>    extern int reserve_bp_slot(struct perf_event *bp);
>>>    extern void release_bp_slot(struct perf_event *bp);
>>> +extern int hw_breakpoint_weight(struct perf_event *bp);
>>> +extern int arch_reserve_bp_slot(struct perf_event *bp);
>>> +extern void arch_release_bp_slot(struct perf_event *bp);
>>> +extern void arch_unregister_hw_breakpoint(struct perf_event *bp);
>>
>> Please no new 'extern'. In the old days 'extern' keyword was used, but
>> new code shall not introduce new unnecessary usage of 'extern' keyword.
>> See report from Checkpatch below:
>>
>> WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description
>> (prefer a maximum 75 chars per line)
>> #9:
>> [1]:
>> https://lore.kernel.org/linuxppc-dev/202005192233.oi9CjRtA%25lkp@intel.com/
>>
>> CHECK:AVOID_EXTERNS: extern prototypes should be avoided in .h files
>> #40: FILE: include/linux/hw_breakpoint.h:83:
>> +extern int hw_breakpoint_weight(struct perf_event *bp);
> 
> I fixed it up when applying.

Thanks Michael.

Ravi