Re: [PATCH] ftrace: Remove unused ftrace_startup_enable() stub

From: Steven Rostedt
Date: Mon Feb 14 2022 - 16:06:37 EST


On Mon, 14 Feb 2022 12:28:47 -0700
Nathan Chancellor <nathan@xxxxxxxxxx> wrote:

> When building with clang + CONFIG_DYNAMIC_FTRACE=n + W=1, there is a
> warning:
>
> kernel/trace/ftrace.c:7194:20: error: unused function 'ftrace_startup_enable' [-Werror,-Wunused-function]
> static inline void ftrace_startup_enable(int command) { }
> ^
> 1 error generated.
>
> Clang warns on instances of static inline functions in .c files with W=1
> after commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
> inline functions for W=1 build").
>
> The ftrace_startup_enable() stub has been unused since
> commit e1effa0144a1 ("ftrace: Annotate the ops operation on update"),
> where its use outside of the CONFIG_DYNAMIC_TRACE section was replaced
> by ftrace_startup_all(). Remove it to resolve the warning.
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>

Thanks,

I'll queue this up for the next merge window. (After it passes all my
testing of course).

-- Steve

> ---
> kernel/trace/ftrace.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index f9feb197b2da..a4b462b6f944 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -7191,7 +7191,6 @@ static int __init ftrace_nodyn_init(void)
> core_initcall(ftrace_nodyn_init);
>
> static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
> -static inline void ftrace_startup_enable(int command) { }
> static inline void ftrace_startup_all(int command) { }
>
> # define ftrace_startup_sysctl() do { } while (0)
>
> base-commit: 754e0b0e35608ed5206d6a67a791563c631cec07