[PATCH 1/3] riscv/ftrace: add ftrace_graph_func

[Conor Dooley]

On Tue, Nov 15, 2022 at 02:15:23PM +0800, Song Shuai wrote:
> Here implements ftrace_graph_func as the function graph tracing function
> with FTRACE_WITH_REGS defined.
> 
> function_graph_func gets the point of the parent IP and the frame pointer
> from fregs and call prepare_ftrace_return for function graph tracing.
> 
> If FTRACE_WITH_REGS isn't defined, the enable/disable helpers of
> ftrace_graph_[regs]_call remain for serving the !FTRACE_WITH_REGS
> version ftrace_caller.
> 
> Signed-off-by: Song Shuai <suagrfillet at gmail.com>

Hey Song,
Last time I saw your email I'd swear it was "sugarfillet", just making
sure that it is not a typo.

Anyways, checkpatch is whinging about some parenthesis stuff:
https://patchwork.kernel.org/project/linux-riscv/patch/20221115061525.112757-2-suagrfillet@gmail.com/

Would be nice to fix that when you resping.

Thanks,
Conor.

> ---
>  arch/riscv/include/asm/ftrace.h | 13 +++++++++++--
>  arch/riscv/kernel/ftrace.c      | 16 ++++++++++++++++
>  2 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
> index 04dad3380041..b33c98070972 100644
> --- a/arch/riscv/include/asm/ftrace.h
> +++ b/arch/riscv/include/asm/ftrace.h
> @@ -81,8 +81,17 @@ do {									\
>  struct dyn_ftrace;
>  int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
>  #define ftrace_init_nop ftrace_init_nop
> -#endif
>  
> -#endif
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +struct ftrace_ops;
> +struct ftrace_regs;
> +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
> +			struct ftrace_ops *op, struct ftrace_regs *fregs);
> +#define ftrace_graph_func ftrace_graph_func
> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> +
> +#endif /* __ASSEMBLY__ */
> +
> +#endif /* CONFIG_DYNAMIC_FTRACE */
>  
>  #endif /* _ASM_RISCV_FTRACE_H */
> diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
> index 2086f6585773..2d7ce77d4f33 100644
> --- a/arch/riscv/kernel/ftrace.c
> +++ b/arch/riscv/kernel/ftrace.c
> @@ -196,6 +196,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
>  }
>  
>  #ifdef CONFIG_DYNAMIC_FTRACE
> +
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +
> +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
> +			struct ftrace_ops *op, struct ftrace_regs *fregs)
> +{
> +	struct pt_regs *regs = arch_ftrace_get_regs(fregs);
> +	unsigned long *parent = (unsigned long *)&(regs->ra);
> +
> +	prepare_ftrace_return(parent, ip, frame_pointer(regs));
> +}
> +
> +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> +
>  extern void ftrace_graph_call(void);
>  extern void ftrace_graph_regs_call(void);
>  int ftrace_enable_ftrace_graph_caller(void)
> @@ -223,5 +237,7 @@ int ftrace_disable_ftrace_graph_caller(void)
>  	return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
>  				    (unsigned long)&prepare_ftrace_return, false);
>  }
> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> +
>  #endif /* CONFIG_DYNAMIC_FTRACE */
>  #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
> -- 
> 2.20.1
>