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Subject: Re: [PATCH v2] ftrace: Cleanup ftrace_dyn_arch_init()
To:     Weizhao Ouyang <o451686892@gmail.com>,
        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>,
        Michael Ellerman <mpe@ellerman.id.au>,
        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
References: <20210906111626.1259867-1-o451686892@gmail.com>
From:   Helge Deller <deller@gmx.de>
Message-ID: <a25be752-bb65-652e-977f-312ee0b95c15@gmx.de>
Date:   Mon, 6 Sep 2021 22:36:32 +0200
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On 9/6/21 1:16 PM, Weizhao Ouyang wrote:
> 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)

Acked-by: Helge Deller <deller@gmx.de> # parisc

Thanks,
Helge


> ---
>
> Changes in v2:
> -- correct CONFIG_DYNAMIC_FTRACE on PowerPC
> -- add Acked-by tag
>
> ---
>   arch/arm/kernel/ftrace.c          | 5 -----
>   arch/arm64/kernel/ftrace.c        | 5 -----
>   arch/csky/kernel/ftrace.c         | 5 -----
>   arch/ia64/kernel/ftrace.c         | 6 ------
>   arch/microblaze/kernel/ftrace.c   | 5 -----
>   arch/mips/include/asm/ftrace.h    | 2 ++
>   arch/nds32/kernel/ftrace.c        | 5 -----
>   arch/parisc/kernel/ftrace.c       | 5 -----
>   arch/powerpc/include/asm/ftrace.h | 4 ++++
>   arch/riscv/kernel/ftrace.c        | 5 -----
>   arch/s390/kernel/ftrace.c         | 5 -----
>   arch/sh/kernel/ftrace.c           | 5 -----
>   arch/sparc/kernel/ftrace.c        | 5 -----
>   arch/x86/kernel/ftrace.c          | 5 -----
>   include/linux/ftrace.h            | 1 -
>   kernel/trace/ftrace.c             | 5 +++++
>   16 files changed, 11 insertions(+), 62 deletions(-)
>
> diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
> index 3c83b5d29697..a006585e1c09 100644
> --- a/arch/arm/kernel/ftrace.c
> +++ b/arch/arm/kernel/ftrace.c
> @@ -193,11 +193,6 @@ int ftrace_make_nop(struct module *mod,
>
>   	return ret;
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif /* CONFIG_DYNAMIC_FTRACE */
>
>   #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
> index 7f467bd9db7a..fc62dfe73f93 100644
> --- a/arch/arm64/kernel/ftrace.c
> +++ b/arch/arm64/kernel/ftrace.c
> @@ -236,11 +236,6 @@ void arch_ftrace_update_code(int command)
>   	command |=3D FTRACE_MAY_SLEEP;
>   	ftrace_modify_all_code(command);
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif /* CONFIG_DYNAMIC_FTRACE */
>
>   #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c
> index b4a7ec1517ff..50bfcf129078 100644
> --- a/arch/csky/kernel/ftrace.c
> +++ b/arch/csky/kernel/ftrace.c
> @@ -133,11 +133,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>   				(unsigned long)func, true, true);
>   	return ret;
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif /* CONFIG_DYNAMIC_FTRACE */
>
>   #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> diff --git a/arch/ia64/kernel/ftrace.c b/arch/ia64/kernel/ftrace.c
> index b2ab2d58fb30..d6360fd404ab 100644
> --- a/arch/ia64/kernel/ftrace.c
> +++ b/arch/ia64/kernel/ftrace.c
> @@ -194,9 +194,3 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>   	flush_icache_range(addr, addr + 16);
>   	return 0;
>   }
> -
> -/* run from kstop_machine */
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
> diff --git a/arch/microblaze/kernel/ftrace.c b/arch/microblaze/kernel/ft=
race.c
> index 224eea40e1ee..188749d62709 100644
> --- a/arch/microblaze/kernel/ftrace.c
> +++ b/arch/microblaze/kernel/ftrace.c
> @@ -163,11 +163,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsign=
ed long addr)
>   	return ret;
>   }
>
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
> -
>   int ftrace_update_ftrace_func(ftrace_func_t func)
>   {
>   	unsigned long ip =3D (unsigned long)(&ftrace_call);
> diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftra=
ce.h
> index b463f2aa5a61..ed013e767390 100644
> --- a/arch/mips/include/asm/ftrace.h
> +++ b/arch/mips/include/asm/ftrace.h
> @@ -76,6 +76,8 @@ do {						\
>
>
>   #ifdef CONFIG_DYNAMIC_FTRACE
> +int __init ftrace_dyn_arch_init(void);
> +
>   static inline unsigned long ftrace_call_adjust(unsigned long addr)
>   {
>   	return addr;
> diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c
> index 0e23e3a8df6b..f0ef4842d191 100644
> --- a/arch/nds32/kernel/ftrace.c
> +++ b/arch/nds32/kernel/ftrace.c
> @@ -84,11 +84,6 @@ void _ftrace_caller(unsigned long parent_ip)
>   	/* restore all state needed by the compiler epilogue */
>   }
>
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
> -
>   static unsigned long gen_sethi_insn(unsigned long addr)
>   {
>   	unsigned long opcode =3D 0x46000000;
> diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
> index 0a1e75af5382..01581f715737 100644
> --- a/arch/parisc/kernel/ftrace.c
> +++ b/arch/parisc/kernel/ftrace.c
> @@ -94,11 +94,6 @@ int ftrace_disable_ftrace_graph_caller(void)
>   #endif
>
>   #ifdef CONFIG_DYNAMIC_FTRACE
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   int ftrace_update_ftrace_func(ftrace_func_t func)
>   {
>   	return 0;
> diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/as=
m/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
> diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
> index 7f1e5203de88..4716f4cdc038 100644
> --- a/arch/riscv/kernel/ftrace.c
> +++ b/arch/riscv/kernel/ftrace.c
> @@ -154,11 +154,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>
>   	return ret;
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif
>
>   #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
> index 0a464d328467..3fd80397ff52 100644
> --- a/arch/s390/kernel/ftrace.c
> +++ b/arch/s390/kernel/ftrace.c
> @@ -262,11 +262,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>   	return 0;
>   }
>
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
> -
>   void arch_ftrace_update_code(int command)
>   {
>   	if (ftrace_shared_hotpatch_trampoline(NULL))
> diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
> index 295c43315bbe..930001bb8c6a 100644
> --- a/arch/sh/kernel/ftrace.c
> +++ b/arch/sh/kernel/ftrace.c
> @@ -252,11 +252,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsign=
ed long addr)
>
>   	return ftrace_modify_code(rec->ip, old, new);
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif /* CONFIG_DYNAMIC_FTRACE */
>
>   #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c
> index 684b84ce397f..eaead3da8e03 100644
> --- a/arch/sparc/kernel/ftrace.c
> +++ b/arch/sparc/kernel/ftrace.c
> @@ -82,11 +82,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>   	new =3D ftrace_call_replace(ip, (unsigned long)func);
>   	return ftrace_modify_code(ip, old, new);
>   }
> -
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
>   #endif
>
>   #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
> index 1b3ce3b4a2a2..23d221a9a3cd 100644
> --- a/arch/x86/kernel/ftrace.c
> +++ b/arch/x86/kernel/ftrace.c
> @@ -252,11 +252,6 @@ void arch_ftrace_update_code(int command)
>   	ftrace_modify_all_code(command);
>   }
>
> -int __init ftrace_dyn_arch_init(void)
> -{
> -	return 0;
> -}
> -
>   /* Currently only x86_64 supports dynamic trampolines */
>   #ifdef CONFIG_X86_64
>
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 832e65f06754..f1eca123d89d 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -573,7 +573,6 @@ ftrace_set_early_filter(struct ftrace_ops *ops, char=
 *buf, int enable);
>
>   /* defined in arch */
>   extern int ftrace_ip_converted(unsigned long ip);
> -extern int ftrace_dyn_arch_init(void);
>   extern void ftrace_replace_code(int enable);
>   extern int ftrace_update_ftrace_func(ftrace_func_t func);
>   extern void ftrace_caller(void);
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 7efbc8aaf7f6..4c090323198d 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -6846,6 +6846,11 @@ void __init ftrace_free_init_mem(void)
>   	ftrace_free_mem(NULL, start, end);
>   }
>
> +int __init __weak ftrace_dyn_arch_init(void)
> +{
> +	return 0;
> +}
> +
>   void __init ftrace_init(void)
>   {
>   	extern unsigned long __start_mcount_loc[];
>