On Tue, 31 Mar 2026 10:20:01 +0200
Bartosz Golaszewski <[email protected]> wrote:
> The tracing_alloc_snapshot() symbol is always exported even with
> !CONFIG_TRACER_SNAPSHOT so the prototype too must be always visible or
> we'll see the following warning:
>
> kernel/trace/trace.c:820:5: warning: no previous prototype for
> ‘tracing_alloc_snapshot’ [-Wmissing-prototypes]
> 820 | int tracing_alloc_snapshot(void)
> | ^~~~~~~~~~~~~~~~~~~~~~
>
> Fixes: bade44fe5462 ("tracing: Move snapshot code out of trace.c and into
> trace_snapshot.c")
> Signed-off-by: Bartosz Golaszewski <[email protected]>
Good catch!
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Thanks!
> ---
> kernel/trace/trace.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 6abd9e16ef21..e8612b8b0a34 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -2275,6 +2275,8 @@ static inline void __init trace_event_init(void) { }
> static inline void trace_event_update_all(struct trace_eval_map **map, int
> len) { }
> #endif
>
> +int tracing_alloc_snapshot(void);
> +
> #ifdef CONFIG_TRACER_SNAPSHOT
> extern const struct file_operations snapshot_fops;
> extern const struct file_operations snapshot_raw_fops;
> @@ -2282,7 +2284,6 @@ extern const struct file_operations snapshot_raw_fops;
> /* Used when creating instances */
> int trace_allocate_snapshot(struct trace_array *tr, int size);
>
> -int tracing_alloc_snapshot(void);
> void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
> int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
> cond_update_fn_t update);
> int tracing_snapshot_cond_disable(struct trace_array *tr);
> --
> 2.47.3
>
--
Masami Hiramatsu (Google) <[email protected]>
