Date: Tue, 18 Nov 2008 16:36:20 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Qinghuang Feng <qhfeng.kernel@gmail.com>
Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
       linux-fsdevel@vger.kernel.org, qhfeng.kernel@gmail.com
Subject: Re: [PATCH] fs/binfmt_misc.c: let binfmt status be more readable
Message-Id: <20081118163620.de14c1ec.akpm@linux-foundation.org>
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On Mon, 17 Nov 2008 15:38:16 +0800
Qinghuang Feng <qhfeng.kernel@gmail.com> wrote:

> The following is what it looks like before patching.
> It is not much readable.
> 
> user@ubuntu:/proc/sys/fs/binfmt_misc$ cat status 
> enableduser@ubuntu:/proc/sys/fs/binfmt_misc$
> 
> Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
> ---
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index f2744ab..72e8b24 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -652,7 +652,7 @@ static const struct file_operations bm_register_operations = {
>  static ssize_t
>  bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
>  {
> -	char *s = enabled ? "enabled" : "disabled";
> +	char *s = enabled ? "enabled\n" : "disabled\n";
>  
>  	return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s));
>  }

Well.  That's a bugfix, really.

It fixes a bug which has been there for a very long time, in a way
which is non-backward-compatible.

Are there existing applications out there which will disastrously fail
if we add a newline to the /proc/sys/fs/binfmt_misc/status contents?  I
somehow doubt it.  But we shall find out :)


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