linux-kernel - Re: [PATCH 2/4] tracing: fix trace_seq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 21 Oct 2009 12:20:35 -0400
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	mingo@...e.hu, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] tracing: fix trace_seq_printf return value

On Wed, 2009-10-21 at 16:36 +0200, Jiri Olsa wrote:
> I believe we want to return the number of written characters,
> instead of the available buffer length.
> 
> wbr,
> jirka
> 
> Signed-off-by: Jiri Olsa <jolsa@...hat.com>
> ---
>  kernel/trace/trace_output.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index ed17565..e871125 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -95,7 +95,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
>  
>  	s->len += ret;
>  
> -	return len;
> +	return ret;

Actually the return value here is ambiguous. Returning len is actually
safer. It probably should only return 0 (buffer not big enough to write
to) or 1 (buffer is big enough).

Because this should actually return non zero:

  trace_seq_printf(s, "");

-- Steve

>  }
>  EXPORT_SYMBOL_GPL(trace_seq_printf);
>  

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/