Re: [PATCH 6/7] V2 add syscall tracepoints

[Li Zefan <lizf@cn.fujitsu.com>]

Jason Baron wrote:
> Allow the return value of raw_init() to bail us out of creating a trace event
> file.
> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
> 
> ---
>  kernel/trace/trace_events.c |   29 +++++++++++++++++++----------
>  1 files changed, 19 insertions(+), 10 deletions(-)
> 
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index aa08be6..aa341ff 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -904,15 +904,6 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
>  	if (strcmp(call->system, TRACE_SYSTEM) != 0)
>  		d_events = event_subsystem_dir(call->system, d_events);
>  
> -	if (call->raw_init) {
> -		ret = call->raw_init();
> -		if (ret < 0) {
> -			pr_warning("Could not initialize trace point"

It was "trace point"

> -				   " events/%s\n", call->name);
> -			return ret;
> -		}
> -	}
> -
>  	call->dir = debugfs_create_dir(call->name, d_events);
>  	if (!call->dir) {
>  		pr_warning("Could not create debugfs "
> @@ -1011,6 +1002,7 @@ static void trace_module_add_events(struct module *mod)
>  	struct ftrace_module_file_ops *file_ops = NULL;
>  	struct ftrace_event_call *call, *start, *end;
>  	struct dentry *d_events;
> +	int ret;
>  
>  	start = mod->trace_events;
>  	end = mod->trace_events + mod->num_trace_events;
> @@ -1026,7 +1018,15 @@ static void trace_module_add_events(struct module *mod)
>  		/* The linker may leave blanks */
>  		if (!call->name)
>  			continue;
> -
> +		if (call->raw_init) {
> +			ret = call->raw_init();
> +			if (ret < 0) {
> +				if (ret != -ENOSYS)
> +					pr_warning("Could not initialize trace"
> +					"point events/%s\n", call->name);

Now it is "tracepoint"

> +				continue;
> +			}
> +		}
>  		/*
>  		 * This module has events, create file ops for this module
>  		 * if not already done.
> @@ -1163,6 +1163,15 @@ static __init int event_trace_init(void)
>  		/* The linker may leave blanks */
>  		if (!call->name)
>  			continue;
> +		if (call->raw_init) {
> +			ret = call->raw_init();
> +			if (ret < 0) {
> +				if (ret != -ENOSYS)
> +					pr_warning("Could not initialize trace"

ditto

> +					"point events/%s\n", call->name);
> +				continue;
> +			}
> +		}
>  		list_add(&call->list, &ftrace_events);
>  		event_create_dir(call, d_events, &ftrace_event_id_fops,
>  				 &ftrace_enable_fops, &ftrace_event_filter_fops,