On Mon, 20 Apr 2026 06:25:09 -0700
Breno Leitao <[email protected]> wrote:

> init_annotated_branch_stats() and all_annotated_branch_stats() check the
> return value of register_stat_tracer() with "if (!ret)", but
> register_stat_tracer() returns 0 on success and a negative errno on
> failure. The inverted check causes the warning to be printed on every
> successful registration, e.g.:
> 
>   Warning: could not register annotated branches stats
> 
> while leaving real failures silent. The initcall also returned a
> hard-coded 1 instead of the actual error.
> 
> Invert the check and propagate ret so that the warning fires on real
> errors and the initcall reports the correct status.
> 

Good catch!

Acked-by: Masami Hiramatsu (Google) <[email protected]>

Thanks,

> Fixes: 002bb86d8d42 ("tracing/ftrace: separate events tracing and stats 
> tracing engine")
> Signed-off-by: Breno Leitao <[email protected]>
> ---
>  kernel/trace/trace_branch.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
> index 6809b370e991d..d1564db95a8f5 100644
> --- a/kernel/trace/trace_branch.c
> +++ b/kernel/trace/trace_branch.c
> @@ -373,10 +373,10 @@ __init static int init_annotated_branch_stats(void)
>       int ret;
>  
>       ret = register_stat_tracer(&annotated_branch_stats);
> -     if (!ret) {
> +     if (ret) {
>               printk(KERN_WARNING "Warning: could not register "
>                                   "annotated branches stats\n");
> -             return 1;
> +             return ret;
>       }
>       return 0;
>  }
> @@ -438,10 +438,10 @@ __init static int all_annotated_branch_stats(void)
>       int ret;
>  
>       ret = register_stat_tracer(&all_branch_stats);
> -     if (!ret) {
> +     if (ret) {
>               printk(KERN_WARNING "Warning: could not register "
>                                   "all branches stats\n");
> -             return 1;
> +             return ret;
>       }
>       return 0;
>  }
> 
> ---
> base-commit: c7275b05bc428c7373d97aa2da02d3a7fa6b9f66
> change-id: 20260420-tracing-3f1367ee4b93
> 
> Best regards,
> --  
> Breno Leitao <[email protected]>
> 


-- 
Masami Hiramatsu (Google) <[email protected]>

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