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Date:   Tue, 11 Apr 2023 23:27:43 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Yosry Ahmed <yosryahmed@google.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] seq_buf: add seq_buf_printk() helper
Message-ID: <20230411142743.GC25053@google.com>
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On (23/04/11 10:10), Steven Rostedt wrote:
[..]
> seq_buf came from trace_seq to become more generic. trace_seq is also part
> of the libtraceevent library, and there we have:
> 
>   trace_seq_do_printf()
> 
>  https://www.trace-cmd.org/Documentation/libtraceevent/libtraceevent-tseq.html
> 
> That is to differentiate the trace_seq_printf() function. And does what
> this function is doing (dumping the buffer).
> 
> Perhaps we should use the precedence of that function and have:
> 
>   seq_buf_do_printk()

OK, I'll rename the helper to seq_buf_do_printk().

> > We should rather use strnchr(). It seems that the trailing '\0' is
> > not guaranteed. For example, seq_buf_putc() just adds the given
> > character at the end.
> 
> I think we should add a seq_buf_terminate() that adds the '\0' to the
> buffer. There's one for user space (trace_seq_terminate()).
> 
> It's a nop if it already has the '\0'.
> 
> I think we should add that first, and then we can use that when entering
> this function.

Sounds good. This also should address Petr's concern.