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

From: Weizhao Ouyang <[email-masked]>
Date: Sat, 4 Sep 2021 19:59:48 +0800

On 2021/9/3 15:18, Weizhao Ouyang wrote:
> Most ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
> ftrace_dyn_arch_init() to cleanup them.
>
> Signed-off-by: Weizhao Ouyang <[email-masked]>
> ---
>  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 |= 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/ftrace.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, unsigned 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 = (unsigned long)(&ftrace_call);
> diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.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 = 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/asm/ftrace.h
> index debe8c4f7062..4db83cf4283f 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_WITH_REGS
> +int __init ftrace_dyn_arch_init(void);
> +#endif
> +

Sorry there is a mistake CONFIG, I will send a v2 patch later.

>  #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, unsigned 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 = 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[];

Thanks.