Re: [PATCH] trace: Fix some checker warnings

[Google]

On Thu, 01 Dec 2022 20:07:39 +0000
David Howells <dhowells@xxxxxxxxxx> wrote:

> Fix some checker warning in the trace code:
> 
>  (1) The declaration of tracing_max_lat_fops should be conditionally
>      defined like its definition.
> 
>  (2) A number of trace functions, and their declarations where present,
>      should have __printf attributes.
> 
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
> 
>  include/linux/trace_events.h |    3 ++-
>  include/linux/trace_seq.h    |    3 ++-
>  kernel/trace/trace.c         |    2 ++
>  kernel/trace/trace.h         |    2 +-
>  kernel/trace/trace_output.c  |    5 +++--
>  5 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> index 20749bd9db71..112b08ca2c5c 100644
> --- a/include/linux/trace_events.h
> +++ b/include/linux/trace_events.h
> @@ -235,7 +235,8 @@ void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
>  void tracing_record_cmdline(struct task_struct *task);
>  void tracing_record_tgid(struct task_struct *task);
>  
> -int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
> +int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
> +	 __printf(3, 4);
>  
>  struct event_filter;
>  
> diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
> index 5a2c650d9e1c..0c4c7587d6c3 100644
> --- a/include/linux/trace_seq.h
> +++ b/include/linux/trace_seq.h
> @@ -97,7 +97,8 @@ extern int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
>  			      const void *buf, size_t len, bool ascii);
>  
>  #else /* CONFIG_TRACING */
> -static inline void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
> +static inline __printf(2, 3)
> +void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
>  {
>  }
>  static inline void
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 5cfc95a52bc3..9da61a54e187 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -1692,7 +1692,9 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
>  }
>  
>  unsigned long __read_mostly	tracing_thresh;
> +#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
>  static const struct file_operations tracing_max_lat_fops;
> +#endif

Oops, I missed this part. Why did you introduced this #ifdefs?

Thank you,

>  
>  #ifdef LATENCY_FS_NOTIFY
>  
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index d42e24507152..ecc6120116da 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -615,7 +615,7 @@ void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
>  bool trace_is_tracepoint_string(const char *str);
>  const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
>  void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
> -			 va_list ap);
> +			 va_list ap) __printf(2, 0);
>  
>  int trace_empty(struct trace_iterator *iter);
>  
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index 67f47ea27921..7039cd883c8b 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -323,8 +323,9 @@ void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...)
>  }
>  EXPORT_SYMBOL(trace_event_printf);
>  
> -static int trace_output_raw(struct trace_iterator *iter, char *name,
> -			    char *fmt, va_list ap)
> +static __printf(3, 0)
> +int trace_output_raw(struct trace_iterator *iter, char *name,
> +		     char *fmt, va_list ap)
>  {
>  	struct trace_seq *s = &iter->seq;
>  
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>