Re: [PATCH 3/3] tracing/kprobe: cleanup unused return value of function

[Masami Hiramatsu <mhiramat@redhat.com>]

Xiao Guangrong wrote:
> Those function's return value is meaningless

Right, now these functions are called from dispatchers,
and return values are wasted.

> 
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

Thanks!

> ---
>  kernel/trace/trace_kprobe.c |   28 ++++++++++++++--------------
>  1 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 6d478c1..5869819 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -942,7 +942,7 @@ static const struct file_operations kprobe_profile_ops = {
>  };
>  
>  /* Kprobe handler */
> -static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
> +static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
>  {
>  	struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
>  	struct kprobe_trace_entry *entry;
> @@ -962,7 +962,7 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
>  	event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
>  						  irq_flags, pc);
>  	if (!event)
> -		return 0;
> +		return ;
>  
>  	entry = ring_buffer_event_data(event);
>  	entry->nargs = tp->nr_args;
> @@ -972,11 +972,11 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
>  
>  	if (!filter_current_check_discard(buffer, call, entry, event))
>  		trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
> -	return 0;
> +	return ;
>  }
>  
>  /* Kretprobe handler */
> -static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
> +static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
>  					  struct pt_regs *regs)
>  {
>  	struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
> @@ -995,7 +995,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
>  	event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
>  						  irq_flags, pc);
>  	if (!event)
> -		return 0;
> +		return ;
>  
>  	entry = ring_buffer_event_data(event);
>  	entry->nargs = tp->nr_args;
> @@ -1007,7 +1007,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
>  	if (!filter_current_check_discard(buffer, call, entry, event))
>  		trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
>  
> -	return 0;
> +	return ;
>  }
>  
>  /* Event entry printers */
> @@ -1217,7 +1217,7 @@ static int set_print_fmt(struct trace_probe *tp)
>  #ifdef CONFIG_PERF_EVENTS
>  
>  /* Kprobe profile handler */
> -static __kprobes int kprobe_profile_func(struct kprobe *kp,
> +static __kprobes void kprobe_profile_func(struct kprobe *kp,
>  					 struct pt_regs *regs)
>  {
>  	struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
> @@ -1232,11 +1232,11 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
>  	size -= sizeof(u32);
>  	if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
>  		     "profile buffer not large enough"))
> -		return 0;
> +		return ;
>  
>  	entry = ftrace_profile_buf_begin(size, call->id, &rctx, &irq_flags);
>  	if (!entry)
> -		return 0;
> +		return ;
>  
>  	entry->nargs = tp->nr_args;
>  	entry->ip = (unsigned long)kp->addr;
> @@ -1245,11 +1245,11 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
>  
>  	ftrace_profile_buf_end(entry, size, rctx, entry->ip, 1, irq_flags);
>  
> -	return 0;
> +	return ;
>  }
>  
>  /* Kretprobe profile handler */
> -static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
> +static __kprobes void kretprobe_profile_func(struct kretprobe_instance *ri,
>  					    struct pt_regs *regs)
>  {
>  	struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
> @@ -1264,11 +1264,11 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
>  	size -= sizeof(u32);
>  	if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
>  		     "profile buffer not large enough"))
> -		return 0;
> +		return ;
>  
>  	entry = ftrace_profile_buf_begin(size, call->id, &rctx, &irq_flags);
>  	if (!entry)
> -		return 0;
> +		return ;
>  
>  	entry->nargs = tp->nr_args;
>  	entry->func = (unsigned long)tp->rp.kp.addr;
> @@ -1278,7 +1278,7 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
>  
>  	ftrace_profile_buf_end(entry, size, rctx, entry->ret_ip, 1, irq_flags);
>  
> -	return 0;
> +	return ;
>  }
>  
>  static int probe_profile_enable(struct ftrace_event_call *call)

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com