From mboxrd@z Thu Jan  1 00:00:00 1970
From: Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v5 bpf-next 06/10] tracepoint: compute num_args at build
 time
Date: Mon, 26 Mar 2018 12:35:30 -0400
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To: Alexei Starovoitov <ast@fb.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, "David S. Miller" <davem@davemloft.net>, Daniel Borkmann <daniel@iogearbox.net>, Linus Torvalds <torvalds@linux-foundation.org>, Peter Zijlstra <peterz@infradead.org>, netdev <netdev@vger.kernel.org>, kernel-team <kernel-team@fb.com>, linux-api <linux-api@vger.kernel.org>, "Frank Ch. Eigler" <fche@redhat.com>
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On Mon, 26 Mar 2018 09:25:07 -0700
Alexei Starovoitov <ast@fb.com> wrote:

> commit log of patch 6 states:
> 
> "for_each_tracepoint_range() api has no users inside the kernel.
> Make it more useful with ability to stop for_each() loop depending
> via callback return value.
> In such form it's used in subsequent patch."
> 
> and in patch 7:
> 
> +static void *__find_tp(struct tracepoint *tp, void *priv)
> +{
> +       char *name = priv;
> +
> +       if (!strcmp(tp->name, name))
> +               return tp;
> +       return NULL;
> +}
> ...
> +       struct tracepoint *tp;
> ...
> +       tp = for_each_kernel_tracepoint(__find_tp, tp_name);
> +       if (!tp)
> +               return -ENOENT;
> 
> still not obvious?

Please just create a new function called tracepoint_find_by_name(), and
use that. I don't see any benefit in using a for_each* function for
such a simple routine. Not to mention, you then don't need to know the
internals of a tracepoint in kernel/bpf/syscall.c.

-- Steve