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Date: Fri, 1 Nov 2024 06:50:23 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>, Florent Revest
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Subject: Re: [PATCH v18 01/17] fgraph: Pass ftrace_regs to entryfunc
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On Fri, 1 Nov 2024 10:51:02 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:

> Ah, good catch! It should put the flag only when HAVE_DYNAMIC_FTRACE_WITH_ARGS
> is enabled.
> 
> static struct ftrace_ops graph_ops = {
> 	.func			= ftrace_graph_func,
> #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
> 	.flags			= FTRACE_OPS_GRAPH_STUB | FTRACE_OPS_FL_SAVE_ARGS,
> #elif defined(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)
> 	.flags			= FTRACE_OPS_GRAPH_STUB | FTRACE_OPS_FL_SAVE_REGS,
> #else
> 	.flags			= FTRACE_OPS_GRAPH_STUB,
> #endif
> 
> This will save fregs or regs or NULL according to the configuration.
> 

Please do not add that to the C code. It's really ugly. Just correct the
comment. Note, FTRACE_OPS_FL_SAVE_ARGS is already dynamic by configuration:

#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
#define FTRACE_OPS_FL_SAVE_ARGS                        FTRACE_OPS_FL_SAVE_REGS
#else
#define FTRACE_OPS_FL_SAVE_ARGS                        0
#endif

I'm a bit confused at what you are trying to achieve here.

-- Steve