Re: [PATCH v2] ftrace: Cleanup ftrace_dyn_arch_init()

From: Weizhao Ouyang <o451686892@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>,
	Michal Simek <monstr@monstr.eu>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Nick Hu <nickhu@andestech.com>, Greentime Hu <green.hu@gmail.com>,
	Vincent Chen <deanbo422@gmail.com>,
	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	Helge Deller <deller@gmx.de>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Rich Felker <dalias@libc.org>,
	"David S. Miller" <davem@davemloft.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org,
	linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org,
	linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
	linux-sh@vger.kernel.org, sparclinux@vger.kernel.org
Subject: Re: [PATCH v2] ftrace: Cleanup ftrace_dyn_arch_init()
Date: Mon, 6 Sep 2021 22:57:53 +0800	[thread overview]
Message-ID: <87b80cd6-f20f-a673-f438-faff5d7d4334@gmail.com> (raw)
In-Reply-To: <87v93dn5qh.fsf@mpe.ellerman.id.au>

On 2021/9/6 22:22, Michael Ellerman wrote:
> Weizhao Ouyang <o451686892@gmail.com> writes:
>> Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
>> ftrace_dyn_arch_init() to cleanup them.
>>
>> Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>
>> Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390)
>>
>> ---
>>
>> Changes in v2:
>> -- correct CONFIG_DYNAMIC_FTRACE on PowerPC
>> -- add Acked-by tag
>> diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
>> index debe8c4f7062..d59f67c0225f 100644
>> --- a/arch/powerpc/include/asm/ftrace.h
>> +++ b/arch/powerpc/include/asm/ftrace.h
>> @@ -61,6 +61,10 @@ struct dyn_arch_ftrace {
>>  };
>>  #endif /* __ASSEMBLY__ */
>>  
>> +#ifdef CONFIG_DYNAMIC_FTRACE
>> +int __init ftrace_dyn_arch_init(void);
>> +#endif /* CONFIG_DYNAMIC_FTRACE */
>> +
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>  #define ARCH_SUPPORTS_FTRACE_OPS 1
>>  #endif
> That breaks the build for powerpc:
>
>   /linux/arch/powerpc/include/asm/ftrace.h: Assembler messages:
>   /linux/arch/powerpc/include/asm/ftrace.h:65: Error: unrecognized opcode: `int'
>   make[4]: *** [/linux/scripts/Makefile.build:352: arch/powerpc/kernel/trace/ftrace_64.o] Error 1
>   make[3]: *** [/linux/scripts/Makefile.build:514: arch/powerpc/kernel/trace] Error 2
>   make[2]: *** [/linux/scripts/Makefile.build:514: arch/powerpc/kernel] Error 2
>   make[1]: *** [/linux/Makefile:1861: arch/powerpc] Error 2
>   make[1]: *** Waiting for unfinished jobs....
>
> It needs to be inside an #ifndef __ASSEMBLY__ section.
>
> cheers

Thanks for reply, I'll fix it up.