Re: [PATCH 14/17] powerpc/ftrace: Replace use of ftrace_call_replace() with ftrace_create_branch_inst()

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 19/06/2023 à 11:47, Naveen N Rao a écrit :
> ftrace_create_branch_inst() is clearer about its intent than
> ftrace_call_replace().
> 
> Signed-off-by: Naveen N Rao <naveen@kernel.org>

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
>   arch/powerpc/kernel/trace/ftrace.c | 17 ++---------------
>   1 file changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index c37e22c6c26521..422dd760fbe013 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -41,19 +41,6 @@ static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr
>   	return op;
>   }
>   
> -static ppc_inst_t
> -ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
> -{
> -	ppc_inst_t op;
> -
> -	addr = ppc_function_entry((void *)addr);
> -
> -	/* if (link) set op to 'bl' else 'b' */
> -	create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
> -
> -	return op;
> -}
> -
>   static inline int ftrace_read_inst(unsigned long ip, ppc_inst_t *op)
>   {
>   	if (copy_inst_from_kernel_nofault(op, (void *)ip)) {
> @@ -275,14 +262,14 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
>   	int ret;
>   
>   	old = ppc_inst_read((u32 *)&ftrace_call);
> -	new = ftrace_call_replace(ip, (unsigned long)func, 1);
> +	new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
>   	ret = ftrace_modify_code(ip, old, new);
>   
>   	/* Also update the regs callback function */
>   	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
>   		ip = (unsigned long)(&ftrace_regs_call);
>   		old = ppc_inst_read((u32 *)&ftrace_regs_call);
> -		new = ftrace_call_replace(ip, (unsigned long)func, 1);
> +		new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
>   		ret = ftrace_modify_code(ip, old, new);
>   	}
>